Low pressure derived mixed phosphorous- and sulfur- containing reaction products useful in power transmitting compositions and process for preparing same

BACKGROUND OF THE INVENTION
The present invention relates to a hydrocarbon soluble or dispersible mixture of phosphorous- and/or sulfur-containing reaction products, their method of preparation, and their utility as antiwear and anti-oxidation additives for oleaginous compositions such as fuel oils, lubricating oils, including power transmission fluids and crankcase oils, and to the oleaginous compositions in which they are contained.
The lubrication of modern mechanical equipment requires that the lubricating oil possess excellent resistance to oxidation as well as the ability to protect metal surfaces in sliding or rolling contact from wear. These properties are vital to the success of any lubricating oil. Additives which improve the resistance of base lubricating oils to oxidation and extend the life of the equipment are of great importance.
Oxidation in lubricating oils manifests itself as an increase in acidity of the oil, increase in oil viscosity, and formation of insoluble products which appear as a sludge. Acidity in the oil is detrimental as it eventually leads to attack of the metal parts in the form of rusting or corrosion. Parts made of the yellow metals, copper, brass and bronze are especially susceptible to this type of attack. Increasing oil viscosity adversely effects the efficiency of the equipment and can lead to the inability to circulate the lubricant through the mechanism. Formation of sludge causes deposits in oil sumps and reservoirs. These deposits, if formed in small lubricant passageways or channels, can block lubricant flow. Excessive viscosity increase or sludge formation can cause failure due to lubricant starvation.
Wear results from the contact of metal surfaces in motion relative to each other. Under low loads and at high relative speeds hydrodynamic lubrication predominates. That is, the two metal parts are separated by a film of oil. This type of lubrication predominates in journal bearings. At higher loads or lower speeds the oil film fails and boundary lubrication becomes the main mechanism of lubrication. In boundary lubrication the two metal surfaces are separated only by a film of chemical additives. Gears operate in boundary lubrication mode. It is highly desirable that lubricating oils contain additives to provide for boundary lubrication conditions.
Control of friction is also possible through modifying the lubricating oil with additives. It is often desirable to modify the frictional performance of a lubricating oil but not necessarily to minimize it. For example, a specialized property sought to be imparted to certain lubricating oil compositions adapted for use as automatic transmission fluids and tractor hydraulic fluids is the ability to control friction to very exacting requirements. These requirements are set forth by the manufacturers of the equipment. This property distinguishes automatic transmission fluids (ATF's) and tractor hydraulic fluids (THF's) from other lubricants; and in fact, there is further differentiation between types of ATF's and THF's.
Such characteristic quality has received the most attention by both the transmission manufacturers and fluid producers for many years. The attention stems from the fact that the friction requirements of these fluids are unique and depend on the transmission and clutch or brake design, as well as on the type of friction materials used.
As is also well known, oxidation, wear and friction can be controlled through the addition of suitable additives with varying degrees of success.
While there are many known additives which may be classified as anti-wear, or friction modifying agents, it is also well known that many of these additives act in a different physical or chemical manner and often compete with one another, e.g., they may compete for the surface of the moving metal parts which are subjected to lubrication. Accordingly, extreme care must be exercised in selection of these additives to insure compatibility and effectiveness.
Both anti-wear and friction modifying agents function by forming a coating on the surface of the moving parts. The coating may be physically adsorbed or it may actually be bonded chemically to the surface. Consequently, if the association between the anti-wear agent and the metal part is stronger than the association between the friction modifying agent and the metal part, the anti-wear agent will displace the friction modifying agent at the metal surface, i.e. at the metal/fluid interface, and friction control will be lost.
Various tests have been designed by automatic transmission manufacturers for measuring ATF friction and anti-wear properties. These tests are used to evaluate the performance of additives and fluids in view of the requirements of particular transmission designs and their ability to impart transmission durability and smooth shifting under a variety of road conditions.
Frictional performance is typically evaluated on an SAE No. 2 friction apparatus. In this test, a test head containing a test clutch pack and the fluid is fitted to an electric motor with an inertia disc. The motor and flywheel of the friction machine (filled with fluid to be tested) are accelerated to constant speed, the motor is shut off and the flywheel speed is decreased to zero by application of the clutch. The clutch plates are then released, the system is again accelerated to constant speed, and the clutch pack which is immersed in the test fluid is engaged again. This process is repeated many times with each clutch engagement being called a cycle.
During the clutch application, friction torque is recorded as a function of time. The friction data obtained are either the torque traces themselves or friction coefficients calculated from the torque traces. The shape of the torque trace desired is set by the auto manufacturers. One way of characterizing this friction performance is to determine the torque: (a) when the flywheel speed is midway between the maximum constant speed selected and zero speed (such torque measurement is referred to herein as T.sub.D) and (b) when as the flywheel speed approaches zero rpm (such torque measurement is referred to herein as T.sub.0). Such torques can then be used to determine the torque ratio which is expressed as T.sub.0 /T.sub.D, or alternatively, to determine the torque differential T.sub.0 -T.sub.D. The optimum target values for torque ratio and torque differential are set by the auto manufacturers. As the T.sub.0 /T.sub.D increasingly exceeds 1, a transmission will typically exhibit shorter harsher shifts as it changes gears. On the other hand as T.sub.0 /T.sub.D decreases below 1, there is an increasingly greater danger of clutch slippage when the transmission changes gears. Similar relationships exist with respect to a T.sub.0 -T.sub.D target value of 0.
While many automatic transmission fluids can achieve target values of T.sub.0 /T.sub.D after a minimum number of cycles, it becomes increasingly more difficult to sustain such target values as the number of cycles are increased. The ability of an ATF to sustain such desired friction properties is referred to herein as friction stability or durability. A high level of friction stability is difficult to achieve with ATFs containing certain anti-wear agents. It is believed that as the ATF ages under the influence of the heat of friction, the anti-wear agent can break down and the decomposition products displace conventional friction modifiers at the metal/fluid interface. As a result, the fluid may exhibit varying friction properties.
Attempts to improve friction stability by simply adding more friction modifier have not met with success because this tends to reduce the breakaway static torque (T.sub.S) of the fluid. This parameter when expressed as the breakaway static torque (T.sub.S) reflects the relative tendency of engaged parts, such as clutch packs, bands and drums, to slip under load. If this value is too low, the slippage can impair the driveability and safety of the vehicle.
Transmission designs have undergone radical changes, thereby necessitating the formulation of ATF additives capable of meeting new and more stringent requirements needed to match such design changes.
No base oil alone can even approach the many special properties required for ATF service. Therefore, it is necessary to employ several chemical additives, each of which is designed to impart or improve a specific property of the fluid. Consequently, it becomes particularly advantageous when one additive can perform more than one function, thereby reducing the number of additives needed to be present in the formulation.
Accordingly, there has been a continuing search for new additives possessed of one or more properties which render them suitable for use in ATF compositions, as well as other oleaginous compositions. There also has been a search for new combinations of additives which not only provide ATF compositions, as well as other oleaginous compositions, with the various specific properties that are required, but which are compatible with each other in the sense that they do not exhibit any substantial tendency to compete with each other, nor to otherwise reduce the effectiveness of the various additives in the compositions. The present invention was developed in response to this search.
U.S. Pat. No. 2,230,966 relates to stabilization of petroleum oils against oxidation by using thiosubstituted alkyl thio ethers of the general structure:
R'(SCR.sub.2 (CR.sub.2).sub.n).sub.x S((CR.sub.2).sub.m CR.sub.2 S).sub.y R'
wherein R represents hydrogen or an alkyl radical; wherein R' represents hydrogen or an alkyl, or aryl or an alkaryl radical (both R' need not be the same), wherein m, n, x and y are whole numbers. These materials are prepared by reaction of alkyl halides and alkyl di-halides with sodium sulfide. No oxygen containing analogues are included.
U.S. Pat. No. 2,346,154 relates to hydrocarbon oil compositions which contain a metal phenate stabilizer, a polyvalent metal salt of an acid of phosphorous containing an organic substituent and a thioether sensitizer which enhances the responsiveness of the hydrocarbon oil to stabilization by the phenate and salt. The thioether sensitizer is claimed as having the structural formula:
R--S--R.sub.1
or the structural formula:
R--S--CC--S--R.sub.1
wherein R and R.sub.1 are alkyl radicals, wherein at least one of R and R.sub.1 contains more than about ten carbon atoms, and wherein the sum of the sum of the number of carbon atoms in R and R.sub.1 is at least about twelve.
U.S. Pat. No. 2,522,512 relates to a process for preparing non-mineral oil base sulfur containing lubricating compositions, wherein a sulfur compound is mixed with a dialkenylether and heated in the presence of a minor amount of a catalyst to form a mixture of polymeric linear adducts of the reactants, and wherein the fraction which volatilizes below 160.degree. C. at 1 cm. mercury pressure is recovered from the polymeric adducts as product. The sulfur compound has the general formula:
R--S--R
wherein both R's are selected from the group consisting of hydrogen atoms and alkyl radicals, and at least one R is a hydrogen atom. The catalyst is selected from the group consisting of dialkylperoxides and alkyl hydroperoxides. The polymeric product contains compounds having units of the general configuration
--S--R--X--R--
wherein X is either S or O, depending upon whether an ether or thioether reactant was used, and each R is an organic radical, preferably a saturated hydrocarbon radical.
U.S. Pat. No. 2,562,144 discloses lubricating compositions containing one or more reaction products. One of the reactants is a polyether of the general formula
R.sub.1 [O--R--S--R].sub.n --O--R.sub.2
wherein R.sub.1 and R.sub.2 are mercaptoalkyl or alkenyl groups and R is a saturated hydrocarbon.
U.S. Pat. No. 2,566,157 discloses a lubricant having as the major ingredient thereof mixed partially isomeric triple ethers of the general formula:
A--S--B--O--B'--S--A'
wherein A, A', B and B' are saturated C.sub.2 -C.sub.18 aliphatic groups. The lubricant also contains a resin such as a polystyrene or acrylic resin, and an aralkyl ester ingredient which is intersoluble with the triple ether ingredient and a solvent of the resin.
U.S. Pat. No. 2,582,605 relates to a process for producing long chain sulfur and oxygen containing polyethers by reacting beta-hydroxyethyl sulfides with alcohols. The process consists of reacting any compound with the functional grouping--SCH.sub.2 CH.sub.2 OH with a hydroxy or polyhydroxy compound in the presence of a strong acid catalyst, preferably sulfuric acid or catalysts which may be considered as being derived from sulfuric acid, e.g., the aryl sulfonic acids or alkyl sulfonic acids (see Col. 8, lines 2-35). The reactions disclosed in this patent are carried out at elevated temperatures being about 130.degree. and 200.degree. C., and preferably between about 140.degree. C. and 160.degree. C..
U.S. Pat. No. 2,721,177 relates to poly-oxyalkylene glycol lubricating oil compositions having improved stability towards oxidative deterioration. The compositions include an aromatic primary oxidation inhibitor and a secondary or auxiliary sulfur-containing oxidation inhibitor. The sulfur-containing inhibitor is characterized by the formula:
R.sub.1 --S (R.sub.2 --O).sub.n --R.sub.3
wherein R.sub.1 is a C.sub.1 -C.sub.20 alkyl group, R.sub.2 is an ethylene or 1,2-propylene alkylene group, R.sub.3 is H, and n is an integer designating the number of alkylene oxide groups. Typically, the average molecular weight of the sulfur-containing secondary inhibitor is between about 250 and 2000.
U.S. Pat. No. 2,750,342 discloses a class of synthetic phosphorous- and sulfur-containing compounds which are useful as lubricating oil additives and which are characterized by the general formula: ##STR1## in which R represents a saturated aliphatic C.sub.2 -C.sub.3 hydrocarbon group, X.sub.1, X.sub.2 and X.sub.3 each represent O or S, and R.sub.1, R.sub.2 and R.sub.3 each represent a C.sub.1 -C.sub.18 alkyl group or a series of saturated aliphatic hydrocarbon groups interlinked by O or S atoms.
U.S. Pat. No. 2,874,192 describes the preparation of mercaptals of long chain hydrocarbon aldehydes and their use as synthetic lubricating oils or anti-oxidants. Compounds of the general formula
(RS).sub.2 CHR'
are produced wherein R is a hydrocarbon radical derived from the mercaptan and R' is a hydrocarbon radical derived from the aldehyde. R and R' are both independently long chain (C.sub.8 to C.sub.30) hydrocarbons.
U.S. Pat. No. 2,960,523 discloses phosphoric ester derivatives of hydroxylakyl vinyl sulfides having the general formula: ##STR2## where A is a C.sub.2 -C.sub.6 alkylene group, and R.sub.1 and R.sub.2 each are C.sub.1 -C.sub.4 alkyl groups. The disclosed ester derivatives can be copolymerizable with various acrylic esters to provide copolymers which have utility as flame-proofing agents for textiles and paper products.
U.S. Pat. No. 3,135,804 relates to polyether-thioethers which are prepared by heating alkoxylation products of aliphatic monovalent alcohols with dihydroxyalkyl sulfides at a temperature between 100.degree.-200.degree. C.. in the presence of relatively small quantities of acid or acid-forming compounds (generally 0.01-5 wt. %, preferably 0.1-1.5 wt. %) such as p-toluene sulfonic acid, orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, phenylphosphoric acid, diphenylphosphoric acid, ammonium phosphate, sodium phosphate, triethyl phosphate, methyl toluene sulfonate, dimethyl sulfate and maleic anhydride. The polyether-thioethers are suitable for use as lubricants, hydraulic fluids, metal working fluids, heat transfer agents, insulating oils, textile assistants and as solvents or additives to high molecular weight compounds.
U.S. Pat. No. 3,335,189 discloses the preparation of polyether-thioethers of the general formula:
R.sub.1 --O--(CHR.sub.2 CHR.sub.3 --O).sub.m --(CHR.sub.4 --CHR.sub.5 --S--CHR.sub.6 --CHR.sub.7 --O).sub.n --(CHR.sub.8 --CHR.sub.9 --O).sub.p --R.sub.10
wherein R.sub.1 and R.sub.10 are linear or branched alkyl radicals of 1 to 22 carbons and R.sub.2 through R.sub.9 represent hydrogen and/or the same or different linear or branched alkyl radicals with 1 to 12 carbon atoms. While m, n and p are whole numbers from 1 to 10. The process disclosed in this patent is carried out at elevated temperatures on the order of 100.degree.-220.degree. C., preferably between 140.degree. and 200.degree. C., in the presence of from about 0.01 to 5 wt. %, preferably 0.1 to 1.5 wt. %, of compounds of trivalent phosphorous, such as phosphorous acid or its salts and esters of phosphorous acid or their salts, or phosphonous acid or its salts, esters, amides or the like. The sole example in this patent discusses the lubricating characteristics of the polyether-thioethers.
U.S. Pat. No. 3,446,738 discloses an ester base lubricating composition comprising an aromatic amine and an organic thiophosphite or thiophosphonate having the formula: ##STR3## wherein X is O or S, at least one X being S; n is 0 or 1, but at least three n s being 1; and R.sub.1, R.sub.2 and R.sub.3 are alkyl or aromatic groups. The organic thiophosphite or thiophosphonate functions as an anti-oxidant.
U.S. Pat. No. 3,426,075 relates to mixed polyphenyl ethers-thioethers useful as synthetic lubricants. These compounds are prepared by reacting sodium or potassium salts of thiophenols with halogen containing diphenyl ethers to produce compounds of the structure:
R--S--R.sub.1 --O--R.sub.1 --S--R
wherein R and R.sub.1 are phenyl or substituted phenyl i.e. containing phenoxy or thiophenyl substituents. R and R.sub.1 are limited to phenyl.
U.S. Pat. No. 3,450,771 describes the process for producing organic sulfides from the reaction of mercaptans with alcohols. The process consists of reacting mercaptans of the formula R--SH with alcohols of the formula R'--OH at a temperature of 100.degree. to 300.degree. C. in the presence of an alkali metal hydroxide to produce organic sulfides of the formula R--S--R' wherein R and R' are hydrocarbyl radicals.
U.S. Pat. No. 3,660,497 discloses dodecylether-methyl sulfides of the general formula:
C.sub.12 H.sub.25 (OCH.sub.2 CH.sub.2).sub.x --S--R
wherein R is a methyl radical when x=1 or 2, and R is a monovalent acetonyl radical when x=0.
U.S. Pat. No. 4,031,023 relates to the use of hydroxy thioethers as oxidation inhibitors and anti-wear agents for lubricating oils. The hydroxy thioethers are of the formula: ##STR4## wherein R is a hydrocarbon group of from C.sub.1 to C.sub.30 ; R' is independently selected from hydrogen or C.sub.1 to C.sub.20 hydrocarbyl; x and y are independently 2 to 5; z is from zero to 5; q is from zero to 4 and m is from 1 to 5 with the proviso that m +q is from 1 to 6.
The materials are prepared by reacting mercaptans with alkylene oxides or by reacting alpha-olefins with hydroxy containing mercaptans.
U.S. Pat. No. 4,081,387 discloses lubricating compositions comprising a major proportion of lubricating oil and a minor proportion of at least one phosphorous- and sulfur-containing additive of the formula:
Y.sup.a --S--Y.sup.b
wherein Y.sup.a is ##STR5## and wherein Z is a saturated or unsaturated hydrocarbyl group; each R.sub.1 and R.sub.2, independently, is a hydrocarbyl, hydrocarbyloxy or hydrocarbylmercapto group having from 1 to 10 carbon atoms; R.sub.3 is hydrogen or a C.sub.1 -C.sub.30 hydrocarbyl group; X is S or O; and Y.sup.b is --R.sub.4 H or --R.sub.4 -- S--R.sub.5, wherein R.sub.4 is a C.sub.1 -C.sub.30 divalent hydrocarbyl group and R.sub.5 is H or Y.sup.a. The disclosed lubricating compositions exhibit increased resistance to oxidative degradation and anti-wear properties.
U.S. Pat. No. 4,217,233 describes the use of epithio compounds as lubricant additives useful as extreme pressure or anti-wear agents. The compounds may be characterized by the formula: ##STR6## wherein X is oxygen or sulfur; Y and Z are together a direct bond; Q is hydrogen; and R is branched or unbranched alkyl of from 8 to 22 carbon atoms (claim 1).
U.S. Pat. No. 4,704,217 describes the use of friction modifiers of the formula: ##STR7## in gasoline crankcase oils wherein R is a (C.sub.1 -C.sub.20) hydrocarbyl radical; R' and R'' are divalent (C.sub.1 -C.sub.10) alkylene groups; a is an integer of about 1 to about 10 and x+y is a value of about 1 to about 20.
U.S. Pat. No. 4,511,480 discloses phosphate esters of oxyalkylated thiols as corrosion inhibitors for ferrous metals in deep gas wells. The disclosed esters have the formula: ##STR8## where R.sub.1 represents alkyl, cycloalkyl, aryl, aralkyl and heterocyclic; R.sub.2 represents alkyl; x is 1-4, m is 1 or 2; n is 1 when m is 2 and n is 2 when m is 1.
U.S. Pat. No. 4,579,672 discloses lubricating compositions comprising a major portion of lubricating oil and a minor proportion of an oil soluble alkoxypolyethyleneoxy acid phosphite ester providing improved water tolerance properties to the oil. The claimed phosphites are of the structure: ##STR9## wherein, R.sub.1 is alkyl or alkenyl; R.sub.2 is OH, alkoxy or oxyalkenyl or R.sub.1 O(CH.sub.2 CH.sub.2 O).sub.x in which the total number of carbon atoms is 8 to 36 and x is in the range 2 to 4.
U.S. Pat. No. 4,776,969 relates to cyclic phosphates, such as 1,3-dioxa-2-phospha-6-thiocyclooctane-2-(dodecylthiodiethyleneoxy)-2-oxide, and their use as an anti-wear, anti-oxidant, and/or friction modifying agent for oleaginous compositions such as fuels and lubricating oils, particularly automatic transmission fluids. The cyclic phosphates can be represented by the formula: ##STR10## where R can represent alkyl, alkenyl, cycloalkyl, aralkyl, alkaryl; n is a number which can vary from 1 to about 3; R.sub.1 is alkylene, n' is a number which can vary from about 1 to about 12; X and X' which may be the same or different can independently represent --O--, --NH-- or --S--; R.sub.2 and R.sub.3 which may be the same or different can independently represent substituted or unsubstituted alkylene; n'' can represent the number 0 or 1; and Y can represent --O--, --NH--, --S--, --S--S-- or CH.sub.2 when n'' is 1; said R.sub.2 and R.sub.3 being joined together and constituting part of a cyclic hetero ring structure when n' is 0. The cyclic phosphates may be prepared by reacting an organo phosphorous oxy dichloride and a cyclizing agent such as thiobisethanol. The non-cyclic portion of the cyclic phosphates typically is derived from a hydrocarbyl thioether alcohol which, in turn, can be prepared by reacting a mercaptan and appropriate alkylene oxide or by reacting a terminal olefin with a compound of the formula HS--(R.sub.1 --O).sub.n' H.
The article "The Condensation of 2-Hydroxyethyl Sulfides with Alcohols and Phenols" by F. Richter, F. B. Augustine, E. Kroft and E. E. Reid, published in Journal of Polymer Science, Vol. XLI, pp 4076-4079, discusses the preparation of ethers by the condensation of alcohols and phenols with 2-hydroxyethyl sulfides using p-toluenesulfonic acids as catalysts.
The article "Thioglycol Polymers I Hydrochloric Acid-Catalyzed Auto Condensation of Thiodiglycol", by Woodward, Journal of Polymer Science, Vol. XLI, pp 219-223 (1959), describes the homopolymerization of thiobisethanol with acid or dehydrating catalyst.
The article "Thioglycol Polymers II Copolymerization of Thiodiglycol and Similar Thioglycols with Aliphatic Hydroxy Compounds", by Andrews et al, Journal of Polymer Science, Vol. XLI, pp 231-239 (1959), describes the acid catalyzed polymerization of thiobisethanol with an alkyl hydroxy or polyhydroxy compound.
U.S. Pat. No. 2,290,880 discloses ethers of alcohol amines which may be used as interface modifying agents in a wide variety of arts. The compounds are said to be useful in lubricating oils and the like, thus enabling the production of effective boring oils, cutting oils, drilling oils, wire drawing oils, extreme pressure lubricants and the like.
U.S. Pat. No. 3,034,907 discloses agents which are effective for hindering or retarding rust formation on iron surfaces and ice formation in the intake system of internal combustion engines. The agents which are disclosed are characterized by a content of (a) a hydrophobic organic carrier, (b) a carboxylic acid amide monocarboxylic acid, and (c) an at least equivalent amount of a hydroxyalkylated nitrogen base which contains at least one lipophilic radical. The hydroxyalkylated nitrogen base corresponds to the general formula: ##STR11## wherein L represents a lipophilic radical; X can represent lower --O-alkylene, --S-alkylene, --O-hydroxyalkylene or --S-hydroxyalkylene, wherein n represents the integer 0 or 1; R.sub.1 represents hydrogen, a lower alkyl or lower hydroxyalkyl or lower aminoalkyl radical; and R.sub.2 is the same as (L-X.sub.n) and R.sub.1. In one embodiment, L represents an aliphatic C.sub.12 -C.sub.18 hydrocarbon radical, n is 0, and at least one of R.sub.1 and R.sub.2 is a low molecular weight hydroxyalkyl or hydroxyalkylaminoethyl radical.
U.S. Pat. No. 3,235,501 discloses foam-inhibited oil compositions which comprise a oleaginous material, a detergent additive, a silicone anti-foamant, and a small amount of a polyalkyl oxylated aliphatic amine which conforms to one of the following formulas (a) or (b) depending on whether the amine from which they are prepared is a mono- or diamine: ##STR12## where R is an aliphatic radical of from about 4 to about 24 carbon atoms, R'O is an alkylene oxide radical selected from the group consisting of the ethylene oxide and propylene oxide radicals, n is an integer from 1 to about 25, and X is selected from hydrogen, R and --(R'O).sub.n H radicals, and ##STR13## where R" is an aliphatic radical having from 2 to about 6 carbon atoms, R'O, n and X are the same as in formula (a), but at least one X is an R radical.
U.S. Pat. No. 3,705,139 discloses alkyl sulfide compounds of the formula:
R.sub.1 --S--R.sub.2 --A--(R.sub.3 O).sub.n Z,
where R.sub.1 represents a hydrocarbyl radical having 6 to 22 carbon atoms, R.sub.2 and R.sub.3 each represents a hydrocarbyl radical having 1 to 4 carbon atoms, A can represent nitrogen, n represents an integer in the range of 0-100, and Z can represent hydrogen. The alkyl sulfide compounds are disclosed as being anti-static agents.
U.S. Pat. No. 3,933,659 discloses lubricating oil composition which comprise a major amount of an oil of lubricating viscosity, and an effective amount of each of the following: (1) an alkenyl succinimide, (2) a Group II metal salt of a dihydrocarbyl dithiophosphoric acid, (3) a compound selected from the group consisting of (a) fatty acid esters of dihydric and other polyhydric alcohols, and oil soluble oxyalkylated derivatives thereof, (b) fatty acid amides of low molecular weight amino acids, (c) N-fatty alkyl-N,N diethanol amines, (d) N-fatty alkyl-N,N-di(ethoxyethanol) amines, (e) N-fatty alkyl-N,N-di-poly(ethoxy) ethanol amines, and (f) mixtures thereof, and (4) a basic sulfurized alkaline earth metal alkyl phenate. Such lubricating compositions are useful as functional fluids in systems requiring fluid coupling, hydraulic fluid and/or lubrication of relatively moving parts, particularly as automatic transmission fluids.
U.S. Pat. No. 4,201,684 relates to lubricating oil compositions adapted for use as a crankcase lubricant in internal combustion engines containing a friction reducing amount of a sulfurized fatty acid amide, ester or ester-amide of an oxyalkylated amine.
U.S. Pat. No. 4,231,883 relates to the use of an alkoxylated hydrocarbyl amine in a lubricating oil or fuel to reduce the friction of an internal combustion engine in which the lubricating oil or fuel is used. An example of the alkoxylated hydrocarbyl amine compounds that are disclosed in this patent is N,N-bis(2-hydroxyethyl) oleylamine.
U.S. Pat. No. 4,129,508 relates to lubricant and fuel compositions characterized by improved demulsifying properties. The patent discloses an automatic transmission fluid which includes a number of additives including a dialkyl phosphite, the reaction product of a polyisobutenyl-substituted succinic anhydride, commercial tetraethylene pentamine, and boric acid prepared as set forth in U.S. Pat. No. 3,254,025, and a conventional friction modifier based on polyoxyethylene tallow amine (Ethomeen T/12), the reaction product of polyisobutenyl succinic anhydride and an ethylene polyamine, and Ethomeen C/15. The Ethomeen compounds are available commercially from the Armak Chemical Division of Akzo Chemie.
U.S. Pat. No. 4,170,560 discloses additive compositions for use in crankcase lubricating oils comprising a mixture of an oil soluble anti-oxidant and an oil soluble hydroxyl amine which includes both Ethomeens and Ethoduomeens, which are trade names for compounds available commercially from the Armak Chemical Division of Akzo Chemie.
U.S. Pat. No. 4,382,006 discloses a lubricating composition containing a friction reducing portion of a borated adduct of compounds which include Ethomeens.
U.S. Pat. No. 3,509,052 relates to lubricating compositions containing a lubricating oil, a dispersant which is a derivative of a substituted succinic acid, and a demulsifier. The demulsifier may comprise, for example, an Ethomeen, but the preferred demulsifiers are polyoxyalkylene polyols and derivatives thereof.
U.S. Pat. No. 3,254,025 relates to boron containing acylated amines and lubricating compositions containing them, the amines are produced by reacting a polymer substituted succinic anhydride containing at least about 50 aliphatic carbon atoms with an amine and then reacting this acylated amine product with boron.
U.S. Pat. No. 3,502,677 relates to substituted polyamines which are useful as additives in lubricating compositions, fuels, hydrocarbon oils and power-transmitting fluids. The substituted polyamines are prepared by reacting an alkylene polyamine with a substantially hydrocarbon-substituted succinic acid-producing compound and a phosphorous acid-producing compound.
U.S. Pat. No. 4,615,818 describes oil-soluble sulfurized organic compounds represented by the formula:
RS.sub.x R.sub.1
wherein R and R.sub.1 are organic groups. Examples of these organic groups include hydrocarbon groups or substituted hydrocarbon groups containing alkyl, aryl, aralkyl, alkaryl, alkanoate, thiazole, imidazole, phosphorothionate, betaketoalkyl groups, etc. The substantially hydrocarbon groups may contain other substituents such as halogen, amino, hydroxyl, mercapto, alkoxy, aryloxy, thio, nitro, sulfonic acid, carboxylic acid, carboxylic acid ester, etc.
U.S. Pat. No. 4,664,826 relates to metal salt esters of hydrocarbyl substituted succinic acid or anhydride, such as octadecenyl succinic anhydride, and alkanols, such as thiobisethanol, which are capable of exhibiting friction modification, oxidation inhibition, and corrosion inhibition properties in power transmitting fluids such as automatic transmission fluids.
U.S. Pat. No. 4,681,694 discloses a crankcase lubricating oil composition comprising (a) a major portion of a lubricating oil which contains at least one over based calcium alkylphenolate or sulfurized calcium alkylphenolate, a zinc dithiophosphate, and dinonyldiphenylamine, and (b) a rust-inhibiting amount of a dialkoxylated alkylpolyoxyalkyl tertiary amine of the formula: ##STR14## where R is C.sub.1 -C.sub.30 alkyl, n is an integer of about 1 to 6, and x+y is about 2 to 30 where neither x nor y is zero.
U.S. Pat. No. 4,702,850 relates to mineral based power transmitting fluids such as automatic transmission fluid which contain an ester of thiobisalkanol and a C.sub.12 -C.sub.50 hydrocarbon succinic acid or anhydride. The ester functions as a multifunctional additive providing friction modification, corrosion inhibition, anti-wear, oxidation inhibition and extreme pressure properties to the fluids. U.S. Pat. No. 4,664,826 discloses metal salt derivatives of such ester additives.
U.S. Pat. No. 4,764,299 deals with compositions containing sulfur and oxygen which are useful in lubricants and automatic transmission fluids. The compositions are prepared by reacting at least two equivalents of a mercaptan containing at least five carbon atoms and at least two equivalents of a beta-dialkanol. The sulfur and oxygen containing compositions may be illustrated by the formula:
RS(AS.sub.x AO).sub.y AS.sub.x ASR.sub.1
wherein x is 1 or greater; y is zero or greater; R and R.sub.1 are hydrocarbyl groups; A is an alkylene group; and at least one of R and R.sub.1 contains at least five carbon atoms.
In an article "Nucleophilic Substitution of Hydroxyl Groups in 2-Alkyl (Aryl)-Thioethanols", published by Fokin et al in the Bull. Acad. Sci. U.S.S.R. Div. Chem. Sci. 1982, Page 1667, there is described the homocondensation of 2-alkylthioethanols. It is also disclosed in the Fokin article that the 2-alkylthioethanol may be reacted with an alcohol under catalysis by strong mineral acids, to give a product containing both sulfur and ether linkages. The mineral acid catalysts disclosed in the Fokin article include HCl, H.sub.3 PO.sub.4, H.sub.2 SO.sub.4, 4-CH.sub.3 C.sub.6 H.sub.4 SO.sub.3 H, HBF.sub.2, HClO.sub.4 and HOSO.sub.2 F. Aromatic sulfur-containing compounds containing beta-hydroxy groups and their reaction properties are also discussed in the Fokin article. The Fokin paper does not discuss any particular utility or special advantage for the compositions described therein.
PCT application WO 88/03554 relates to phosphorous- and/or nitrogen-containing derivative compositions which are useful in fuels, and in lubricating and functional fluid compositions. The derivative compositions comprise a phosphorous- and/or nitrogen-containing derivative composition of sulfur-containing compounds prepared by reacting at least one sulfur composition with either a di- or trihydrocarbyl phosphite, an amine compound containing at least one NH or NH.sub.2 group, or a combination of such phosphite and amine. The sulfur compositions which may be reacted with the phosphite, amine or a combination of phosphite and amine may be characterized by the formula ##STR15## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or hydrocarbyl groups; R.sub.1 and/or R.sub.3 may be G.sub.1 or G.sub.2 ; R.sub.1 and R.sub.2 and/or R.sub.3 and R.sub.4 together may be alkylene groups containing about four to about seven carbon atoms; G.sub.1 and G.sub.2 are each independently C(X)R, COOR, C.dbd.N, R.sub.5 --C.dbd.NR.sub.6, CON(R).sub.2, or NO.sub.2, and G.sub.1 may be CH.sub.2 OH; X is S or O; and each of R, R.sub.5 and R.sub.6, independently, is H or a hydrocarbyl group. The compositions of this patent also may include at least on carboxylic dispersant composition.
SUMMARY OF THE INVENTION
In co-pending applications, Ser. No. 370,315, filed Jun. 22, 1989 and Ser. No. 559,385, filed Jul. 25, 1990, it has been disclosed that a phosphorous- and sulfur-containing product mixture can be formed by the reaction, preferably simultaneous reaction, of a beta-hydroxy thioether reactant, an organic phosphite ester reactant and, optionally, a nucleophilic reactant selected for its ability to react with an episulfonium cation of the formula ##STR16## It was disclosed, further, that the product mixture comprised non-phosphorous-containing thioether-containing species and organo phosphorous-containing species which are very effective in enhancing the anti-wear and anti-oxidation characteristics of oleaginous compositions, such as fuels and lubricating oils, to which they are added.
The product mixture that is disclosed in said co-pending applications may be prepared under conditions which favor the formation of a stable single phase mixture which is compatible with oleaginous compositions, or it may be prepared under conditions which favor the formation of a mixture which separates on standing into a top phase, which is rich in thioether-containing species, and a bottom phase, which is rich in phosphorous-containing species, although both phases contain mixtures of species found in each phase. In such cases, both the top phase mixture and the bottom phase mixture are stable, compatible with oleaginous compositions, and do not adversely affect friction stability of automatic transmission fluids. In short, each of the single phase phosphorous- and sulfur-containing product mixtures, the thioether enriched top phase mixture, and the organo phosphorous enriched bottom phase mixture disclosed in said co-pending applications, independently, were considered to be a desirable additive for use in oleaginous compositions, particularly in power transmission fluids.
It has now been found that by carrying out the reaction disclosed in said co-pending applications at a reduced pressure rather than reducing the pressure upon completion of the reaction, the overall process time can be reduced by as much as about 30%. It has been found, further, that the resulting product mixture advantageously comprises a lower amount (relative to the atmospheric reaction) of non-phosphorous-containing thioether-containing species, and, generally speaking, is characterized by a lower total acid number (TAN).
In one aspect of the present invention, a mixed reaction product is prepared by simultaneously reacting (1) a beta-hydroxy thioether reactant, and (2) phosphorous-containing reactant, and (3) optionally, a nucleophilic reactant, at a pressure on the order of about -40 KPa to about -100 KPa and a temperature of from about 70.degree. to about 130.degree. C. The beta-hydroxy thioether reactant (BHTE) is characterized by the formula I:
R(SCH.sub.2 CH.sub.2 OH).sub.x I
wherein R represents an unsubstituted or substituted hydrocarbyl group, and x is 1 or 2.
The phosphorous-containing reactant comprises organic phosphite ester.
In another aspect of the invention, a mixed reaction product is prepared by simultaneously reacting at a temperature of from about 70.degree. C. to about 130.degree. C. and a reduced pressure of from about -40 KPa to about -100 KPa (1) organic phosphite ester, (2) hydrocarbyl thioalkanol and (3) heterodialkanol. The organic phosphite ester reactant is represented by at least one of the following formulas II, III or IV: ##STR17## wherein R.sub.1, independently, represents the same or different C.sub.1 -C.sub.30 (typically C.sub.1 -C.sub.5) saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical.
The hydrocarbyl thioalkanol material is characterized by one of the following formulas V and VI: ##STR18## wherein R.sub.2 represents a saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical (typically C.sub.8 -C.sub.30) having at most two unsaturated linkages; R.sub.3 represents a C.sub.2 -C.sub.4 alkanetriyl radical; R.sub.4 represents H or a C.sub.1 -C.sub.12 saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical; R.sub.5 represents a C.sub.2 -C.sub.16 saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical; and n represents 1-6.
The heterodialkanol is characterized by the formula VII: ##STR19## where R.sub.6 and R.sub.7 each independently can represent hydrogen and C.sub.1 to about C.sub.12 alkyl (preferably straight chain alkyl), preferably C.sub.1 to about C.sub.6 alkyl, and most preferably C.sub.1 to about C.sub.3 alkyl; Z is a linking group selected from --S--, --S--S--, --O--, and >NR.sub.18, wherein R.sub.18 is hydrogen, C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 to about C.sub.3 alkyl, and monohydroxy-substituted alkyl, preferably a terminal monohydroxy-substituted alkyl, the alkyl being as described above in connection with R.sub.6 and R.sub.7 ; and a, b, c, and d each independently represent numbers which can vary from 1 to about 3. Preferably, R.sub.6 and R.sub.7 are the same, the numbers represented by b and d are the same, as are the numbers represented by a and c.
In another aspect of the invention, the hereindescribed mixed reaction product is employed as an anti-wear additive in an oleaginous composition. The mixed reaction product, when used in combination with an ashless dispersant and a friction modifier, and preferably also with a seal swellant and an anti-oxidant, is particularly suited to meeting the stringent ATF requirements from the standpoint of the proper balance of anti-wear, static and dynamic friction coefficients, friction modification and stability, dispersancy, sludge inhibition, anti-oxidation and corrosion resistance properties.
In a still further embodiment of the present invention, there is provided a lubricating oil composition concentrate adaptable for use as an automatic transmission fluid comprising the above-described mixed reaction products, preferably in combination with at least a dispersant and a friction modifier.
In another embodiment of the present invention, there is provided a lubricating oil composition concentrate adaptable for use as a power transmitting fluid which comprises a lubricating oil having dissolved or dispersed therein the above-described mixed reaction product, together with an ashless dispersant, and a hydroxyl amine friction modifier such as those depicted in formulas VIII and IX as follows: ##STR20## wherein R.sub.8 represents H or CH.sub.3, R.sub.9 represents a C.sub.3 -C.sub.27 saturated or unsaturated, substituted or unsubstituted, aliphatic hydrocarbyl radical; R.sub.10 and R.sub.13, independently, represent the same or different straight or branched chain C.sub.1 -C.sub.6 alkylene radical; R.sub.11 and R.sub.12, independently, represent the same or different straight or branched chain C.sub.2 -C.sub.5 alkylene radical; R.sub.14 represents a straight or branched chain C.sub.1 -C.sub.5 alkylene radical; X represents O or S; p represents 0 or 1; and q, independently, represents the same or different integer 1-4.
In another embodiment of the present invention there is provided a process for improving the anti-wear and anti-oxidation properties of a lubricating oil composition which is adapted for use as a power transmitting fluid which comprises adding to said lubricating oil composition the phosphorous- and sulfur-containing mixtures of reaction products disclosed herein, in addition to an ashless dispersant and a friction modifier.
In still another embodiment of the present invention there is provided a process for preparing a multifunctional lubricating oil additive by reacting together, preferably simultaneously, at a temperature of from about 70.degree. C. to about 130.degree. C. at a reduced pressure of from about -40 KPa to about -100 KPa, (1) beta-hydroxy thioether reactant and (2) organic phosphite ester reactant, the reaction being terminated when the total acid number (TAN) of the mixed reaction product is observed to be from about 10 to about 140, depending upon the identity of the organic phosphite ester reactant.
In yet another aspect of the invention, there is provided a composition comprising the reaction product of a reaction mixture comprising (1) a beta-hydroxy thioether reactant represented by the formula:
R--(SCH.sub.2 CH.sub.2 OH).sub.x I
wherein R represents an unsubstituted or substituted hydrocarbyl group and wherein x is a number from 1 to 2 which identifies the number of --SCH.sub.2 CH.sub.2 OH groups attached to R; and
(ii) an amount of phosphorous-containing reactant selected from the group consisting of monohydrocarbyl dihydrogen phosphite, dihydrocarbyl hydrogen phosphite, trihydrocarbyl phosphite, and mixtures thereof, sufficient to provide at least about ten mole percent of phosphorous containing reactant, based on the total moles of reactants in said reaction mixture; wherein the reaction mixture is admixed in a manner and under conditions sufficient:
(A) to form hydrocarbyl phosphorous-containing product comprising at least 80 mole % of a mixture of hydrocarbyl phosphites, wherein at least one phosphite of said mixture is represented by the formula XI: ##STR21## and at least one phosphite of said mixture is represented by formula XII: ##STR22## wherein each "R", independently represents the same or different residue from (i) beta-hydroxy thioether reactant, and (ii) hydrocarbyl oxy residue from said phosphorous-containing reactant, provided that at least some of "R" constitutes beta-hydroxy thioether residue, and wherein said hydrocarbyl phosphorous-containing product comprises at least 25 mole % of said composition, and
(B) to limit the formation of thioether-containing species which can form during said reaction to less than about 45 mole % of said composition.

DESCRIPTION OF PREFERRED EMBODIMENTS
In one preferred embodiment, the phosphorous- and sulfur-containing anti-wear additives of the present invention comprise a mixture of compounds which are formed by reacting in admixture, preferably in simultaneous admixture, the following components, namely: (1) beta-hydroxy thioether reactant, and (2) organic phosphite reactant, and, optionally, (3) nucleophilic reactant.
The beta-hydroxy thioether reactant is characterized by the formula I:
R(SCH.sub.2 CH.sub.2 OH).sub.x I
wherein R represents an unsubstituted hydrocarbyl or a substituted hydrocarbyl group, and x is 1 or 2.
As used in this specification and claims, the term "substituted hydrocarbyl group" is meant to include hydrocarbyl groups which contain at least one pendant or internal hetero-atom containing species selected from the group consisting of hydroxy, oxy, thio, oxyalkylene and oxyalkylenethio groups. Thus, the term "substituted hydrocarbyl group" is intended to include --CH.sub.2 CH.sub.2 OH within its scope, but to exclude from within its scope --C(X)R.sub.2', --COOR.sub.2', --C.dbd.N, --R.sub.3' C.dbd.NR.sub.4', --CON(R.sub.2').sub.2 or --NO.sub.2 groups, wherein X is O or S, and wherein R.sub.2, R.sub.3 and R.sub.4, independently, represent H or a hydrocarbyl group.
Typically, R will be a C.sub.1 -C.sub.30 (e.g., C.sub.2 -C.sub.5), preferably C.sub.2 to about C.sub.18 (e.g., C.sub.8 to C.sub.18), saturated or unsaturated, straight or branched chain (preferably straight chain) aliphatic hydrocarbyl radical; an aromatic radical, preferably a C.sub.6 -C.sub.14 aromatic radical or a mixed alkaryl or aralkyl radical having from 1 to about 30 typically 1 to about 22, and preferably 1 to about 10 carbon atoms in the alkyl portion thereof; the radical; ##STR23## an R.sub.20 OH radical or an --SR.sub.20 OH radical. In the above radicals, R.sub.20 and R.sub.15, independently are described as in connection with R as aliphatic, aromatic, and mixed aliphatic/aromatic; z is 0 or 1; m is a number of from about 1 to about 6, preferably 1 to 3; R.sub.16 is C.sub.2 -C.sub.4 alkanetriyl (e.g., C.sub.2 alkanetriyl), and R.sub.17 is H or C.sub.1 -C.sub.18, preferably C.sub.1 -C.sub.5 aliphatic, preferably saturated aliphatic hydrocarbyl.
It will be appreciated, of course, that the groups identified in formula I as --(SCH.sub.2 CH.sub.2 OH).sub.x are not a block of repeating units. Rather, each --(SCH.sub.2 CH.sub.2 OH) group is a single group bonded appropriately to the hydrocarbyl backbone of the R group in the thioether reactant.
In one preferred aspect, the beta-hydroxy thioether reactant comprises a mixture of compounds of formula I wherein at least one compound has only one --SCH.sub.2 CH.sub.2 OH group (i.e. x=1) and at least one compound has two --SCH.sub.2 CH.sub.2 OH groups (i.e. x=2).
Representative examples of suitable R, R.sub.20, and R.sub.15 groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-butenyl, hexyl, 2-ethyl hexyl, n-octyl, decyl, dodecyl, dodecenyl, octadecyl octadecenyl, oleyl, stearyl, i-stearyl, hydroxystearyl, benzyl, phenyl, p-methylphenyl, p-propylphenyl, o-butylphenyl, p-butylphenyl, p-dodecylphenyl, p-dodecenylphenyl p-octadecylphenyl, p-octadecenylphenyl, naphthyl, ethoxyethyl, ethoxythioethyl, or the like.
The more preferred R groups include octyl, decyl, dodecyl and octadecyl.
The more preferred R.sub.20 or R.sub.15 groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and n-pentyl.
In more preferred embodiments the value of x in formula I is 1 and R is independently selected from --CH.sub.2 CH.sub.2 OH and C.sub.8 to C.sub.18 alkyl.
Methods for preparing the beta-hydroxy thioether reactant are known in the art and are discussed, for example, in Reed, Organic Chemistry of Bivalent Sulfur, Vol. II (1960), published by Chemical Publishing Co., Inc., and in U.S. Pat. No. 4,031,023, the disclosures of which are incorporated herein by reference. The beta-hydroxy thioether reactant may be prepared, for example, by heating together at a temperature of from about 140.degree. to about 160.degree. C. an alkyl mercaptan and an epoxide compound in the presence of a basic catalyst, e.g., NaOH. Alternatively, the beta-hydroxy thioether reactant can be prepared by heating together in the presence of a free radical generator, such as benzoyl peroxide, an alkyl mercaptan such as 2-mercaptoethanol and an alpha-olefin such as 1-decene.
The phosphorous-containing reactant comprises organic phosphite ester represented by at least one of the following formulas II, III or IV: ##STR24## wherein R.sub.1, independently, represents the same or different C.sub.1 -C.sub.30 (typically C.sub.1 -C.sub.5) saturated or unsaturated, straight or branched chain aliphatic hydrocarbyl radical, and wherein R.sub.1 may be substituted.
Representative examples of suitable R.sub.1 groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-propenyl, n-butenyl, n-hexyl, nonylphenyl, n-dodecyl, n-dodecenyl, hexadecyl, octadecenyl, stearyl, i-stearyl, hydroxystearyl, and the like.
The more preferred R.sub.1 groups will yield volatile alcohols which are stripped from the reaction mixture during reaction and include methyl, ethyl, n-propyl, n-butyl, particularly n-butyl. Although not required, it is preferred that the R.sub.1 groups are the same for any given organic phosphite ester. The most preferred trimethyl phosphite, triethyl phosphite, tributyl phosphite, and the like, and dihydrocarbyl hydrogen phosphites, such as dimethyl hydrogen phosphite, dibutyl hydrogen phosphite, and the like. The organic phosphites can be obtained, for example, by the direct esterification of phosphorous acid, by reaction of a phosphorous trihalide with an alcohol or a mixture of alcohols, or by reaction of phosphorous acid with an epoxide. The methods for preparing the organic phosphite ester reactant are known in the art and are discussed, for example, in U.S. Pat. No. 3,513,093, the disclosure of which is incorporated herein by reference.
In one preferred embodiment, the composition of the present invention is prepared by reacting in admixture, preferably simultaneous admixture, (a) organic phosphite reactant, and (b) organic sulfur-containing reactant comprising (i) hydrocarbyl thioalkanol component, and (ii) heterodialkanol component, with the proviso that at least one of the hydrocarbyl thioalkanol or heterodialkanol components contains at least one --SCH.sub.2 CH.sub.2 OH group thereby qualifying the same as a preferred species of beta-hydroxy thioether.
The organo phosphite component (a) is the same as phosphorous-containing reactant of formulas II, III or IV described above.
The hydrocarbyl thioalkanol reactant (b)(ii) is represented by at least one of the following formulas V and VI: ##STR25## wherein R.sub.2 represents a saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical having not greater than about two unsaturated linkages, (preferably straight chain alkyl) typically about C.sub.8 -C.sub.30, preferably about C.sub.8 -C.sub.20, and most preferably about C.sub.10 -C.sub.14 alkyl; R.sub.3 represents a C.sub.2 -C.sub.4 alkanetriyl radical, preferably C.sub.2 alkanetriyl; R.sub.4 represents H (most preferred) or a saturated or unsaturated, substituted or unsubstituted, straight or branched chain hydrocarbyl radical (preferably straight chain alkyl), typically about C.sub.1 -C.sub.18, preferably C.sub.1 -C.sub.14, and most preferably C.sub.1 -C.sub.12 alkyl; R.sub.5 represents a saturated or unsaturated, substituted or unsubstituted straight or branched chain hydrocarbyl radical, (preferably straight chain alkylene), typically C.sub.2 -C.sub.30, preferably C.sub.2 -C.sub.20, and most preferably C.sub.2 -C.sub.16 alkylene; and n represents a number from 1 to about 6, preferably 1 to about 3. Typically, n is 1 when R.sub.3 is C.sub.3 alkanetriyl and can vary from 1 to about 6, preferably 1 to about 3 when R.sub.3 is C.sub.2 alkanetriyl. When n is greater than 1, formula V is meant to express alkoxylated derivatives of thio-alkanols, such as ethoxylated derivatives.
Representative examples of suitable compounds falling within the scope of the above structural formulas V and VI are shown below in Tables 1 and 2, in chart form, wherein each of the variable groups is associated with specific compounds. In selecting suitable compounds from Tables 1 and 2, collectively, at least one such compound must contain at least one --SCH.sub.2 CH.sub.2 OH group if the heterodialkanol of formula VII does not contain any --SCH.sub.2 CH.sub.2 OH groups. In cases where the heterodialkanol of formula VII does not contain any --SCH.sub.2 CHOH groups, the selected compounds from Tables 1 and 2 which contain at least one --SCH.sub.2 CH.sub.2 OH group are employed to form episulfonium cations which are necessary for the desired reaction to occur. When the hydrocarbyl thioalkanol does not contain, an --SCH.sub.2 CH.sub.2 OH group, it can participate in the reaction as a nucleophilic reactant which is believed to react with the episulfonium cation to form thioether-containing species.
Preferably, however, both the hydrocarbyl thialkanol reactant and the heterodialkanol reactant are selected to possess the --SCH.sub.2 CH.sub.2 OH group.
TABLE 1______________________________________ ##STR26##R.sub.2 R.sub.3 R.sub.4 n______________________________________C.sub.8 H.sub.17 CH.sub.2CH CH.sub.3 1C.sub.10 H.sub.20 CH.sub.2CHCH.sub.2 C.sub.2 H.sub.5 1C.sub.12 H.sub.25 CH.sub.2CH H 1C.sub.14 H.sub.29 CH.sub.2CH C.sub.2 H.sub.5 2C.sub.15 H.sub.31 CH.sub.2CH C.sub.3 H.sub.7 3C.sub.20 H.sub.40 CH.sub.2CH C.sub.6 H.sub.13 3C.sub.25 H.sub.51 CH.sub.2CH C.sub.12 H.sub.25 1C.sub.30 H.sub.61 CH.sub.2CHCH.sub.2 C.sub.18 H.sub.37 1______________________________________
TABLE 2______________________________________Formula R.sub.2 --S--R.sub.5 --OH VI______________________________________ R2 R5 C.sub.8 H.sub.17 -- --C.sub.2 H.sub.4 -- C.sub.10 H.sub.20 -- --C.sub.3 H.sub.6 -- C.sub.12 H.sub.25 -- --C.sub.4 H.sub.8 -- C.sub.14 H.sub.27 -- --C.sub.10 H.sub.20 -- C.sub.15 H.sub.31 -- --C.sub.10 H.sub.20 -- C.sub.20 H.sub.40 -- --C.sub.2 H.sub.4 -- C.sub.25 H.sub.51 -- --C.sub.5 H.sub.10 -- C.sub.30 H.sub.61 -- --C.sub.10 H.sub.20 --______________________________________
When R.sub.3 is C.sub.2 alkanetriyl, the hydrocarbyl thioalkanol reactants of formula V may be prepared, for example, by heating together at a temperature of about 140.degree. to about 160.degree. C. an alkyl mercaptan and an epoxide compound in accordance with the following equation: ##STR27## where R.sub.2 and R.sub.4 are described above.
When R.sub.3 is C.sub.3 alkanetriyl, the hydrocarbyl thioalkanol reactant of formula V may be prepared, for example, by heating together in the presence of a free radical generator, such a benzoyl peroxide, an alkyl mercaptan and an alkenol in accordance with the following equation: ##STR28## where R.sub.2 and R.sub.4 are described above and ROO represents an organic peroxide free radical initiator.
The hydrocarbyl thioalkanol reactant of formula VI may be prepared, for example, by mixing together in the presence of an alkaline catalyst, such as sodium hydroxide, an alkyl halide and a hydroxy alkyl mercaptan in accordance with the following equation: ##STR29##
The heterodialkanol reactant (b)(ii) is characterized by the formula: ##STR30## where R.sub.6 and R.sub.7 each independently can represent hydrogen, and C.sub.1 to about C.sub.12 alkyl (preferably straight chain alkyl), preferably C.sub.1 to about C.sub.6 alkyl, and most preferably C.sub.1 to about C.sub.3 alkyl; Z is a linking group selected from --S-- (preferably --S--), --S--S--, --O--, and >NR.sub.18, wherein R.sub.18 is hydrogen, C.sub.1 -C.sub.22 alkyl, preferably C.sub.1 to about C.sub.18 alkyl, and monohydroxy-substituted alkyl, preferably a terminal monohydroxy-substituted alkyl, the alkyl being as described above in connection with R.sub.6 and R.sub.7 ; a, b, c, and d each independently represent numbers which can vary from 1 to about 3, preferably 1 or 2. Preferably, R.sub.6 and R.sub.7 are the same, the numbers represented by b and d are the same, and the numbers represented by a and c are the same, thereby resulting in formula VII defining a bisalkanol. Preferably the heterodialkanol reactant (b) (ii) contains at least one --SCH.sub.2 CH.sub.2 OH group; however, it is only necessary that at least one of the heterodialkanol reactant (b) (ii) or the hydrocarbyl thioalkanol reactant (b) (i) contain at least one --SCH.sub.2 CH.sub.2 OH. When the heterodialkanol does not contain an --SCH.sub.2 CH.sub.2 OH group, it constitutes another species of nucleophilic reactant.
When Z is --O--, formula VII can represent ethylene glycol and derivatives thereof; when Z is >NR.sub.18, and R.sub.18 is alkyl or hydrogen, formula VII can represent a diethanolamine and derivatives thereof; when R.sub.18 is a monohydroxy-substituted alkyl, such as --(CH.sub.2).sub.2 OH, formula VII can represent triethanolamine and derivatives thereof.
If b or d are greater than 1, then formula VII is meant to express alkoxylated derivatives of the heterodialkanols, such as ethoxylated derivatives.
The preferred heterodialkanols are thiodialkanols, wherein in formula VII, Z is --S--, and R.sub.6 and R.sub.7 are, independently, hydrogen, ethyl or methyl.
In the most preferred thiodialkanols of formula VII, a, b, c and d are each 1 or 2 (preferably 1), R.sub.6 is hydrogen or methyl, R.sub.7 is hydrogen, methyl or ethyl, and Z is sulfur.
Representative thiodialkanols include 2,2'-thiodiethanol; 3,3'-thiodipropanol; thio-bis ethoxyethanol; thiobisisopropoxyisopropanol; bis-(3-hydroxypropyl)disulfide; and mixtures thereof.
When Z is sulfur, the thiodialkanol reactants may be prepared, for example by reacting a thiobisalkanol with an epoxide compound.
It will be appreciated that it is possible for both the hydrocarbyl thioalkanol component (b)(i) and the heterodialkanol component (b)(ii) to satisfy the above-described formula I for the beta-hydroxy thioether component.
The reaction of the beta-hydroxy thioether and the phosphorous-containing reactant, and the nucleophilic reactant, if such nucleophilic reactant were to be employed, is performed, for example, by first charging the reactants to a suitable batch reactor (over a period of from about 0.5 to about 5.5 hours), preheating the reaction mixture to a temperature on the order of about 70.degree. to about 130.degree. C., typically 80.degree. to about 115.degree. C., (over a period of about 0.5 to about 2.0 hours), and then mixing the reactants and heating or soaking the reaction mixture under reduced pressure conditions, preferably continuously reduced pressure for the duration of the reaction, typically at from about -40 KPa to about -100 KPa, and preferably from about -50 to about -80 KPa, e.g., -60 KPa, to remove by-product alcohol from the reaction mixture as it is evolved at a reaction temperature of typically from about 70.degree. to about 130.degree. C., (e.g., 80.degree. to about 115.degree. C.) preferably from about 90.degree. to about 118.degree. C., (e.g., 95.degree. to 115.degree. C.), and most preferably from about 90.degree. to about 100.degree. C. when a phosphorous-containing reactant of formula III or IV is employed, and from about 110.degree. to about 118.degree. C. when a phosphorous-containing reactant of formula II is employed. The heating or soaking step is continued for a period of time of typically from about 1 to about 24 hours, preferably from about 4 to about 18 hours, and most preferably from about 7 to about 12 hours. The reaction mixture is then cooled down (over a period of from about 1 to about 4 hours) without having to undergo a separate alcohol stripping step which was employed in the process described in co-pending Ser. Nos. 210,831 and 370,315 and which typically would be accomplished in a period of from about 3.5 to about 15 hours.
The reaction could also be carried out continuously in a suitable vessel.
It will be noted that a portion of the by-product alcohol, as illustrated hereinafter in equation 4, may function as a nucleophilic reactant that is prepared in situ, since the alcohol may react with the episulfonium cation, to yield thioether-containing species. However, since the present process is carried out under sub-atmospheric pressure conditions in the reactor, most of the by-product alcohol is continuously removed during the course of reaction. Typically, the identity of R.sub.1 of the phosphite reactant is selected to facilitate alcohol removal.
A convenient way to determine completion of the reaction is to periodically monitor the reaction mixture by removing samples therefrom and subjecting the samples to infrared analysis. As the reaction proceeds, a hydrogen phosphite peak will appear (at 4.1 micron on the IR spectra) and its height will continue to grow over the course of the reaction. At the same time, the height of the hydroxyl peak (at 2.9 microns on the IR spectra) attributable to alcohol by-product and any hydroxyl-containing reactants will diminish. Accordingly, at some point in time during the reaction, the height of the hydrogen phosphite peak will exceed the height of the hydroxyl peak.
The reaction is terminated at any time after this point, and preferably before the point at which the hydroxyl peak disappears altogether. If the reaction is continued beyond the point at which the hydroxyl peak disappears, phase separations can occur.
A more preferred way to determine the completion of the reaction is to periodically monitor the reaction mixture by removing samples therefrom and subjecting the samples to a titration which measures the total acid number (TAN). The reaction is deemed complete for the purposes of this invention when the measured TAN is from about 10 to about 70, preferably from about 30 to about 60, and most preferably from about 40 to about 50 when a phosphorous-containing reactant having the formula II is employed, and from about 80 to about 140, preferably 80 to about 130, and most preferably 90 to about 120 when a phosphorous-containing reactant having the formula III or IV is employed.
As pointed out in co-pending Ser. No. 370,315, under certain conditions, e.g., continuing the reaction beyond its intended end point, removing all of the alcohol by-product and/or conducting the reaction at higher than the prescribed temperatures or prolonged exposure of the product mixture to air, the resulting product mixture sometimes tends to separate into two separate phases. The reason for this subsequent phase separation is not entirely understood. However, it has also been disclosed in said co-pending application that to avoid such phase separation, it is advantageous to replace the by-product alcohol which is evolved during the reaction with a relatively high molecular weight alcohol (e.g., C.sub.8 to C.sub.18 alcohol), such as tridecylalcohol. However, the addition of the higher molecular weight alcohol generally should not be conducted until the product mixture has cooled to below reaction temperature and typically is conducted at temperatures of from 30.degree. to about 70.degree. C. Otherwise, the higher molecular weight alcohol can enter into reaction with the product which may not be desirable.
Typically, the higher molecular weight alcohol is added to achieve a weight ratio of Product:Alcohol of from about 80:20 to about 95:5, preferably 90:10.
If phase separation does occur, the phases may be homogenized into a single phase mixture with, for example, a suitable cosolvent such as tridecyl alcohol. However, the separate phases can be used independently from one another.
The reaction between the beta-thioether reactant and the phosphorous-containing reactant (and optional nucleophilic reactant) may be performed with or without a catalyst, however, it is preferable to perform the reaction in the presence of a basic catalyst such as sodium methoxide to decrease the reaction time. Other suitable basic catalysts which may be employed include, for example, sodium phenate, tertiary amines such as triethylamine or pyridine, and metal carbonates such as potassium carbonate, sodium carbonate or magnesium carbonate.
In a less preferred embodiment, the reactive components can be added and mixed sequentially, provided that the mixing is complete prior to attaining the reaction temperatures specified above and provided, further, that the reaction is carried out under reduced pressure conditions, e.g., -60 KPa.
The reaction may be illustrated generically by the following equation 4: ##STR31##
With reference to the above equation 4, it is believed that the alcohol, i.e. R.sub.1 OH, generated during the reaction can react with the episulfonium cation group, ##STR32## and be incorporated into the thioether-containing species. From an analysis of the thioether-containing and phosphorous-containing species in the product mixture, it appears that other species in the reaction mass react with the episulfonium cation ##STR33## group as well. These other species include, for example, R(SCH.sub.2 CH.sub.2 OH).sub.x reactant, species derived from the phosphorous-containing reactant, the optionally added nucleophilic reactant and mixtures of these species.
It will be appreciated that during the course of the reactions of this invention, the hydroxyl groups contained in the sulfur-containing reactants (including substituent hydroxyl groups other than those forming part of an --SCH.sub.2 CH.sub.2 OH group), as well as the hydroxyl groups contained in the nucleophilic reactant, are capable of undergoing reaction with the phosphorous-containing reactant and episulfonium cation. It will be appreciated, further, that both the hereindescribed beta-hydroxy thioether reactant and the optional nucleophilic reactants can have multiple hydroxyl substituents. Thus, the amount of each reactant employed is influenced by the number of reactive functional groups present on each reactant. It has been found that increases in the number of hydroxyl groups on the non-phosphorous containing reactant desirably are accompanied by an increase in the amount of phosphorous-containing reactant.
Accordingly, it is contemplated that typically at least about 10, preferably at least about 15 (e.g., at least about 20) mole percent, of phosphorous containing reactant, based on the total moles of reactants, will be employed. More specifically, such amounts can vary typically from about 10 to about 60, preferably from about 20 to about 50, and most preferably from about 25 to about 40 mole % of phosphorous-containing reactant, based on the total moles of reactants.
The ratio of total molar equivalents of hydroxy groups in the beta hydroxy thioether reactants, such as, for example, the sulfur-containing reactants (b)(i) and (b)(ii) of formula V and VI, collectively to the moles of phosphorous contained in the phosphite reactant in the reaction mixture is controlled to be typically about 1 to 5:1, preferably about 2 to 4:1, and most preferably about 2.5 to 3.5:1. In one preferred aspect, the ratio of molar equivalents of --SCH.sub.2 CH.sub.2 OH groups of beta hydroxy thioether to moles of phosphorous in the phosphorous-containing reactant is from about 0.1 to 2:1 (e.g., 0.5 to 1.5:1), preferably about 1:1.
Moreover, since the nucleophilic reactant is not believed to be capable of forming the episulfonium cation, it is contemplated that such reactant will comprise typically not greater than about 50, preferably not greater than about 25, and most preferably not greater than about 10 mole %, based on the total number of moles of reactants employed.
It has been found that immediate removal of evolved organic alcohol derived from the organic phosphite reactants of formulas II, III or IV under reduced pressure conditions results in a reduction in the amount of sulfur-containing thioether components being formed in the product mixture relative to the same reaction conducted at atmospheric pressure. While the reason for this occurrence is not entirely understood, it has been found that the presence of decreased amounts of sulfur-containing thioethers in the product mixture is accompanied by the presence of increased amounts of phosphorous-containing ester components. It has been found further that the thioether species which are formed are less beneficial in terms of antioxidation and wear resistance performance than the phosphite ester species which are formed. Accordingly, the removal of the by-product alcohol from the reaction products as soon as possible (i.e., during reaction) by means of the reduced pressure conditions of the present invention not only reduces cycle time, but also has the additional benefit of limiting the presence of non-phosphorous thioether species (i.e., sulfur-containing thioether species) to less than about 45 mole %, preferably less than 40 mole %, and most preferably less than 30 mole % of the composition of this invention, as compared to as much as about 70 mole % or more of sulfur-containing thioether species when the reaction is performed at atmospheric pressure.
Typically, the identity of R.sub.1 of the phosphite reactant is selected to facilitate alcohol removal by means of the reduced pressure conditions in the reaction.
Compositions prepared in accordance with the invention comprise:
(i) hydrocarbyl phosphorous containing product comprising at least 80 mole % of a mixture of mono- and dihydrocarbyl phosphites having within their structure at least some hydrocarbyl group represented by the formula:
R--SCH.sub.2 CH.sub.2 O-- I'
bonded directly to the phosphorous atom of the organic phosphite, said R--SCH.sub.2 CH.sub.2 O-- group representing a residue of beta-hydroxy thioether; and optionally,
(ii) non-phosphorous containing compounds having within their structure at least one group represented by the formula:
--S--CH.sub.2 CH.sub.2 --Q-- I''
wherein Q is independently selected from the group consisting of oxygen or sulfur, said Q constituting a portion of the residue derived from: (1) beta-hydroxy thioether reactant (the --SCH.sub.2 CH.sub.2 OH group-containing reactant or reactants), (2) the hydrocarbyl portion of the organic phosphite reactant, (3) when present, the nucleophilic reactant, and (4) mixtures of (1) to (3); and wherein the remainder of Structure I'', exclusive of Q, contains residue of beta-hydroxy thioether reactant.
It should be noted that the terms non-phosphorous-containing species or thioether containing species (sometimes referred to as non-phosphorous thioether-containing species), as used herein, are intended to collectively represent a material which contains at least the --S-- (i.e. thioether species) but also the --O-- (i.e. oxyether species) in the same molecule. For example when an --SCH.sub.2 CH.sub.2 OH group reacts, via the episulfonium cation intermediate, with a hydroxyl group of another reactant molecule the species --SCH.sub.2 CH.sub.2 O-- is formed. Thus, the complexity of product mixture constituting the thioether containing species is a function of the complexity of the initial starting reactants. In all instances, however, the thioether product will always contain at least one --SCH.sub.2 CH.sub.2 --Q-- group where Q is S or most preferably --O--. Difunctional reactants (e.g., those which contain two hydroxyl groups (including the hydroxyl group present on an --SCH.sub.2 CH.sub.2 OH group) will contain at least two --SCH.sub.2 CH.sub.2 Q-- groups, and so forth.
While not all of the hydrocarbyl groups present in the mono- and dihydrocarbyl phosphite reaction product mixture must possess hydrocarbyl groups conforming to the R--SCH.sub.2 CH.sub.2 O-- formula, at least some of said species must possess at least one hydrocarbyl group containing residue of beta-hydroxy thioether.
Those hydrocarbyl groups present in the mono- and dihydrocarbyl phophite product mixture not derived from beta-hydroxy thioether will comprise those derived from the optional nucleophilic reactant and/or the hydrocarbyl group originally present in the organic phosphite reactant.
Minor amounts of other phosphorous-containing species which can be present in the hydrocarbyl phosphorous containing product comprise organic phosphonates and alkyl thylphosphites.
Such organic phosphorous-containing species can be represented by the following structural formulas: ##STR34## wherein each "R", independently, represents the same or different residue from (i) beta hydroxy thioether reactant, i.e., R--SCH.sub.2 CH.sub.2 O--, (ii) nucleophilic reactant, when employed, e.g., R.sub.2 --S--(R.sub.3 O).sub.2 -- and (iii) the hydrocarbyl oxy residue from the starting phosphite reactant, e.g., R.sub.1 --O--; and R" represents residue of any of the reactants, as defined in connection with "R" with the exception that the bridging oxy group linking said "R" residue to phosphorous is absent.
When "R" represents a residue of beta-hydroxy thioether reactant, it can be depicted as follows:
(HOCH.sub.2 CH.sub.2 S).sub.x-1 --R--SCH.sub.2 CH.sub.2 O--I.sub.1
wherein R is as described in connection with formula I, and wherein x is a number of 1 or 2 and x-1 identifies the number of additional --SCH.sub.2 CH.sub.2 OH groups which may be attached directly to R.
When "R" represents beta-hydroxy thioether derived from heterodialkanol represented by formula VII, it can be depicted as follows: ##STR35## wherein R.sub.6, R.sub.7, a, b, c, d, and Z are as described in connection with formula VII.
When "R" represents residue of beta-hydroxy thioether derived form formulas V and VI, it can be depicted as follows: ##STR36## wherein R.sub.2 is as described above in connection with formulas V and VI, R.sub.4 is hydrogen and R.sub.3 and R.sub.5 are --CH.sub.2 CH.sub.2 --.
As indicated above, of the species constituting the organic phosphorous-containing species, the monohydrocarbyl and dihydrocarbyl phosphites predominate.
While the complex mixture of organic phosphorous-containing species and non-phosphorous-containing thioether species are both believed to contribute to the oxidation resistance and anti-wear performance observed to be present in the mixed reaction product, it is now believed that such performance can be maximized by limiting (e.g. minimizing) the amount of non-phosphorous-containing thioether species in the mixed reaction product to less than about 45 mole %, preferably less than about 40 mole %, and more preferably less than about 30 mole %. The formation of non-phosphorous-containing thioether species removes reactant which would otherwise be available for reaction to form the more desirable phosphite product. Thus, in the present invention, one seeks to increase phosphite product at the expense of thioether formation. However, it is preferred to have at least some non-phosphorous-containing thioether species in the mixed reaction product, although in its broader aspects, it is contemplated that the mixed reaction product may be devoid of any non-phosphorous-containing thioether species.
The collective amounts of the organic phosphorous-containing species and the non-phosphorous-containing thioether species can be determined, for example, from .sup.31 P NMR and .sup.13 C NMR analysis of the product mixture. As described in co-pending serial number 370,315, the .sup.31 P NMR measurements can be taken at 40.degree. C. on a JEOL GSX-400 NMR Spectrometer operating at 161.70 MHz. Samples would be prepared to be between 20 and 30% wt/wt in CDCl.sub.3. Standard single pulse experiments would be conducted using a preacquisition pulse delay of 6 sec and 45.degree. observe flip angle. All broadband .sup.1 H decoupling would be was gated off during preacquisition and evolution and on during data acquisition. These conditions assure that the observed signals are relatively quantitative.
Chemical shifts reported would be referenced to concentrated H.sub.3 PO.sub.4 contained externally in a capillary tube. The spectral observation window would be selected to be 35211.3 Hz or 2 times the normal chemical shift range with 32K data points per scan. All fast Fourier transforms would be done with a normal gaussian line broadening of 1-4 Hz. Integration intensities would be digitially measured and the values normalized to mole percents.
The .sup.13 C NMR measurements can be taken on a JEOL GSX-400 NMR Spectrometer operating at 100.40 MHz. The samples to be analyzed would be prepared to between 20 and 30 % wt/wt in CDCl.sub.3. A standard single pulse experiment would be used with a 90.degree. flip angle, and preacquisition delay of 4 sec. Broadband decoupling would be gated off during preacquisition and evolution and on throughout data acquisition. Chemical shifts reported would be internally referenced to deuterochloroform. The spectral observation window would be selected to be 24038.5 Hz with 16K data points per scan. All FFT's would be done with a 4 Hz guassian line broadening multiplication prior to transformation. Integral intensities would be digitally measured and the values would be reported in mole percents.
By use of the .sup.31 P NMR and .sup.13 C NMR analysis discussed above, it has been found that the process of this present invention, i.e., conducted at a reduced pressure of from about -40 KPa to about -100 KPa, results in formation of hydrocarbon soluble or dispersible reaction product mixture comprising hydrocarbyl phosphorous-containing product and sulfur-containing (thioether) product, wherein the sulfur-containing product comprise less than about 45 mole % of the reaction product mixture, wherein the reaction product mixture comprises at least 25 mole % phosphorous-containing product, and wherein at least 80 mole % of the phosphorous-containing product in the reaction product mixture comprise monohydrocarbyl phosphite and dihydrocarbyl phosphite compounds represented by the above illustrated formulas XI and XII.
It has been found that the phosphorous- and sulfur-containing reaction product mixtures of the present invention, which contain less than 45 mole % sulfur-containing ether species, possess excellent anti-wear and anti-oxidation properties.
Accordingly, the various reaction product mixtures of the invention are used by incorporation and dissolution or dispersion into an oleaginous material such as fuels and lubricating oils.
The additives produced in accordance with the present invention have been found to be useful in fuel oils and lubricating oils. The normally liquid fuel oils are generally derived from petroleum sources, e.g., normally liquid petroleum distillate fuels, though they may include those produced synthetically by the Fischer-Tropsch and related processes, the processing of organic waste material or the processing of coal, lignite or shale rock. Such fuel compositions have varying boiling ranges, viscosities, cloud and pour points, etc., according to their end use as is well know to those of skill in the art. Among such fuels are those commonly known as diesel fuels, distillate fuels e.g., gasoline, heating oils, residual fuels, bunker fuels, etc., which are collectively referred to herein as fuel oils. The properties of such fuels are well known to skilled artisans as illustrated, for example, by ASTM Specification D #396-73, available from the American Society for Testing Materials, 1916 Race street, Philadelphia, Pa. 19103.
Middle distillate fuel oils include distillates boiling from about 120.degree. to 725.degree. F. (e.g., 375.degree. to 725.degree. F.), including kerosene, diesel fuels, home heating fuel oil, jet fuels, etc., and most preferably whose 20% and 90% distillation points differ by less than 212.degree. F., and/or whose 90% to final boiling point range is between about 20.degree. and 50.degree. F. and/or whose final boiling point is in the range of 600.degree. to 700.degree. F.
The reaction product mixtures prepared in accordance with the reduced pressure process of the present invention find their primary utility in lubricating oil compositions which employ a base oil in which the mixtures are dissolved or dispersed.
Such base oils may be natural or synthetic although the natural base oils will derive a greater benefit.
Thus, base oils suitable for use in preparing lubricating compositions of the present invention include those conventionally employed as crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines, such as automobile and truck engines, marine and railroad diesel engines, and the like. Particularly advantageous results are achieved by employing the phosphorous- and sulfur-containing product mixtures of the present invention in base oils conventionally employed in power transmitting fluids such as automatic transmission fluids, tractor fluids, universal tractor fluids and hydraulic fluids, heavy duty hydraulic fluids, power steering fluids and the like. Gear lubricants, industrial oils, pump oils and other lubricating oil compositions can also benefit from the incorporation therein of the phosphorous- and sulfur-containing reaction product mixtures of the present invention.
Thus, the reaction product mixtures of the present invention may be suitably incorporated into synthetic base oils such as alkyl esters of dicarboxylic acids, polyglycols and alcohols; polyalphaolefins; alkyl benzenes; organic esters of phosphoric acids; polysilicone oil; etc.
Natural base oils include mineral lubricating oils which may vary widely as to their crude source, e.g., whether paraffinic, naphthenic, mixed paraffinic-naphthenic, and the like; as well as to their formation, e.g., distillation range, straight run or cracked, hydrofined, solvent extracted and the like.
More specifically, the natural lubricating oil based stocks which can be used in the compositions of this invention may be straight mineral lubricating oil or distillates derived from paraffinic, naphthenic, asphaltic, or mixed base crudes, or, if desired, various blended oils may be employed as well as residuals, particularly those from which asphaltic constituents have been removed. The oils may be refined by conventional methods using acid, alkali, and/or clay or other agents such as aluminum chloride, or they may be extracted oils produced, for example, by solvent extraction with solvents such as phenol, sulfur dioxide, furfural, dichlorodiethyl ether, nitrobenzene, crotonaldehyde, etc.
The lubricating oil base stock conveniently has a viscosity of typically about 2.5 to about 12, and preferably about 3.5 to about 9 cst. at 100.degree. C.
Thus the reaction product mixtures of the present invention can be employed in a lubricating oil composition which comprises lubricating oil, typically in a major amount, and a reaction product mixture typically in a minor amount, which is effective to impart enhanced anti-wear and friction stability properties relative to the absence of the additive mixture. Additional conventional additives selected to meet the particular requirements of a selected type of lubricating oil composition can be included as desired.
The reaction product mixtures of this invention are oil soluble, dissolvable in oil with the aid of a suitable solvent, or are stably dispersible in oil. Oil soluble, dissolvable, or stably dispersible, as that terminology is used herein, does not necessarily indicate that the materials are soluble, dissolvable, miscible, or capable of being suspended in oil in all proportions. It does mean, however, that the respective components of the mixture are soluble or stably dispersible in oil to an extent sufficient to exert their intended effect in the environment in which the oil is employed. Moreover, the incorporation of a dispersant, friction modifier and/or other additives may also permit incorporation of higher levels of a particular reaction product mixture if desired.
A phosphorous- and sulfur-containing reaction product mixture additive of the present invention can be incorporated into the lubricating oil in any convenient way. Thus, a product mixture can be added directly to the oil by dispersing, or dissolving the same in the oil at the desired level of concentration typically with the aid of the suitable solvent such as dodecylbenzene or naphthalene base stock. Such blending can occur at elevated temperatures of 60.degree.-100.degree. C.
The lubricating oil base stock for the additive mixtures of the present invention typically is adapted to perform a selected function by the incorporation of additives therein to form lubricating oil compositions (i.e., formulations).
As indicated above, one broad class of lubricating oil compositions suitable for use in conjunction with the additives of the present invention are power steering fluids, tractor fluids, tractor universal oils, and the like.
The benefits of the additives of the present invention are particularly significant when employed in a lubricating oil adapted for use as an automatic transmission fluid.
Power transmitting fluids, such as automatic transmission fluids, as well as lubricating oils in general, are typically compounded from a number of additives each useful for improving chemical and/or physical properties of the same. The additives are usually sold as a concentrate package in which mineral oil or some other base oil is present. The mineral lubricating oil in automatic transmission fluids typically is refined hydrocarbon oil or a mixture of refined hydrocarbon oils selected according to the viscosity requirements of the particular fluid, but typically would have a viscosity range of 2.5-9, e.g., 3.5-9 cst. at 100.degree. C. Suitable base oils include a wide variety of light hydrocarbon mineral oils, such as naphthenic base oils, paraffin base oils, and mixtures thereof.
Representative additives which can be present in such packages as well as in the final formulation include viscosity index (V.I.) improvers, corrosion inhibitors, oxidation inhibitors, friction modifiers, lube oil flow improvers, dispersants, anti-foamants, anti-wear agents, detergents, metal rust inhibitors and seal swellants.
Viscosity modifiers impart high and low temperature operability to the lubricating oil and permit it to maintain sufficient viscosity at elevated temperatures and also exhibit acceptable viscosity or fluidity at low temperatures.
V.I. improvers are generally high molecular weight hydrocarbon polymers or more preferably polyesters. The V.I. improvers may also be derivatized to include other properties or functions, such as the addition of dispersancy properties.
These oil soluble V.I. polymers will generally have number average molecular weights of from 10.sup.3 to 10.sup.6, preferably 10.sup.4 to 10.sup.6, e.g., 20,000 to 250,000, as determined by gel permeation chromatography or membrane osmometry.
Examples of suitable hydrocarbon polymers include homopolymers and copolymers of two or more monomers of C.sub.2 to C.sub.30, e.g., C.sub.2 to C.sub.8 olefins, including both alpha-olefins and internal olefins, which may be straight or branched, aliphatic, aromatic, alkyl-aromatic, cycloaliphatic, etc. Frequently they will be of ethylene with C.sub.3 to C.sub.30 olefins, particularly preferred being the copolymers of ethylene and propylene. Other polymers can be used such as polyisobutylenes, homopolymers and copolymers of C.sub.6 and higher alpha- olefins, atactic polypropylene, hydrogenated polymers and copolymers and terpolymers of styrene, e.g., with isoprene and/or butadiene.
More specifically, other hydrocarbon polymers suitable as viscosity index improvers in the present invention include those which may be described as hydrogenated or partially hydrogenated homopolymers, and random, tapered, star, or block interpolymers (including terpolymers, tetrapolymers, etc.) of conjugated dienes and/or monovinyl aromatic compounds with, optionally, alpha-olefins or lower alkenes, e.g., C.sub.3 to C.sub.18 alpha-olefins or lower alkenes. The conjugated dienes include isoprene, butadiene, 2,3-dimethylbutadiene, piperylene and/or mixtures thereof, such as isoprene and butadiene. The monovinyl aromatic compounds include vinyl di- or polyaromatic compounds, e.g., vinyl naphthalene, or mixtures of vinyl mono-, di- and/or polyaromatic compounds, but are preferably monovinyl monoaromatic compounds, such as styrene or alkylated styrenes substituted at the alpha-carbon atoms of the styrene, such as alpha-mehtylstyrene, or at ring carbons, such as o-, m-, p-methylstyrene, ethylstyrene, propylstyrene, isopropylstyrene, butylstyrene isobutylstyrene, tert-butylstyrene (e.g., p-tert-butylstyrene). Also included are vinylxylenes, methylethylstyrenes and ethylvinylstyrenes. Alpha-olfins and lower alkenes optionally included in these random, tapered and block copolymers preferably include ethylene, propylene, butene, ethylene-propylene copolymers, isobutylene, and polymers and copolymers thereof. As is also known in the art, these random, tapered and block copolymers may include relatively small amounts, that is less than about 5 mole %, of other copolymerizable monomers such as vinyl pyridines, vinyl lactams, methacrylates, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl stearate, and the like.
Specific examples include random polymers of butadiene and/or isoprene and polymers of isoprene and/or butadiene and styrene. Typical block copolymers include polystyrene-polyisoprene, polystyrene-polybutadiene, polystyrene-polyethylene, polystyrene-ethylene propylene copolymer, polyvinyl cyclohexane-hydrogenated polyisoprene, and polyvinyl cyclohexane-hydrogenated polybutadiene. Tapered polymers include those of the foregoing monomers prepared by methods known in the art. Star-shaped polymers typically comprise a nucleus and polymeric arms linked to said nucleus, the arms being comprised of homopolymer or interpolymer of said conjugated diene and/or monovinyl aromatic monomers. Typically, at least about 80% of the aliphatic unsaturation and about 20% of the aromatic unsaturation of the star-shaped polymer is reduced by hydrogenation.
Representative examples of patents which disclose such hydrogenated polymers or interpolymers include U.S. Pat. Nos. 3,312,621, 3,318,813, 3,630,905, 3,668,125, 3,763,044, 3,795,615, 3,835,053, 3,838,049, 3,965,019, 4,358,565, and 4,557,849, the disclosures of which are herein incorporated by reference.
The polymer may be degraded in molecular weight, for example by mastication, extrusion, oxidation or thermal degradation, and it may be oxidized and contain oxygen. Also included are derivatized polymers such as post-grafted interpolymers of ethylene-propylene with an active monomer such as maleic anhydride which may be further reacted with an alcohol, or amine, e.g., an alkylene polyamine or hydroxy amine, e.g., see U.S. Pat. Nos. 4,089,794, 4,160,739, 4,137,185, or copolymers of ethylene and propylene reacted or grafted with nitrogen compounds such as shown in U.S. Pat. Nos. 4,068,056, 4,068,058, 4,146,489 and 4,149,984.
Suitable hydrocarbon polymers are ethylene copolymers containing from 15 to 90 wt % ethylene, preferably 30 to 80 wt. % of ethylene and 10 to 85 wt. % , preferably 20 to 70 wt. % of one or more C.sub.3 to C.sub.28, preferably C.sub.3 to C.sub.18, more preferably C.sub.3 to C.sub.8, alpha-olefins. While not essential, such copolymers preferably have a degree of crystallinity of less than 25 wt. %, as determined by X-ray and differential scanning calorimetry. Copolymers of ethylene and propylene are most preferred. Other alpha-olefins suitable in place of propylene to form the copolymer, or to be used in combination with ethylene and propylene, to form a terpolymer, tetrapolymer, etc., include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc.; also branched chain alpha-olefins, such as 4-methyl-1-pentene, 4-methyl-1-hexene, 5-methylpentene-1, 4,4-dimethyl-1-pentene, and 6-methyl-heptene-1, etc., and mixtures thereof.
Terpolymers, tetrapolymers, etc., of ethylene, said C.sub.3-28 alpha-olefin, and non-conjugated diolefin or mixtures of such diolefins may also be used. The amount of the non-conjugated diolefin generally ranges from about 0.5 to 20 mole percent, preferably from about 1 to about 7 mole percent, based on the total amount of ethylene and alpha-olefin present.
The preferred V.I. improvers are polyesters, most preferably polyesters of ethylencially unsaturated C.sub.3 to C.sub.8 mono- and dicarboxylic acids such as methacrylic and acrylic acids, maleic acid, maleic anhydride, fumaric acid, etc.
Examples of unsaturated esters that may be used include those of aliphatic saturated mono alcohols of at least 1 carbon atom and preferably of from 12 to 20 carbon atoms, such as decyl acrylate, lauryl methacrylate, cetyl methacrylate, stearyl methacrylate, and the like and mixtures thereof.
Other esters include the vinyl alcohol esters of C.sub.2 to C.sub.22 fatty or monocarboxylic acids, preferably saturated such as vinyl acetate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and the like and mixtures thereof. Copolymers of vinyl alcohol esters with unsaturated acid esters such as the copolymer of vinyl acetate with dialkyl fumarates, can also be used.
The esters may be copolymerized with still other unsaturated monomers such as olefins, e.g., 0.2 to 5 moles of C.sub.2 -C.sub.20 aliphatic or aromatic olefin per mole of unsaturated ester, or per mole of unsaturated acid or anhydride followed by esterification. For example, copolymers of styrene with maleic anhydride esterified with alcohols and amines are known, e.g., see U.S. Pat. No. 3,702,300.
Such ester polymers may be grafted with, or the ester copolymerized with, polymerizable unsaturated nitrogen-containing monomers to impart dispersancy to the V.I. improvers. Examples of suitable unsaturated nitrogen-containing monomers to impart dispersancy include those containing 4 to 20 carbon atoms such as amino substituted olefins as p-(beta-diethylaminoethyl)styrene; basic nitrogen-containing heterocycles carrying a polymerizable ethylenically unsaturated substituent, e.g., the vinyl pyridines and the vinyl alkyl pyridines such as 2-vinyl-5-ethyl pyridine, 2-methyl-5-vinyl pyridine, 2-vinyl-pyridine, 3-vinyl-pyridine, 4-vinyl-pyridine, 3-methyl-5-vinyl-pyridine, 4-methyl-2-vinyl-pyridine, 4-ethyl-2-vinyl-pyridine and 2-butyl-5-vinyl-pyridine and the like.
N-vinyl lactams are also suitable, e.g., N-vinyl pyrrolidones or N-vinyl piperidones.
The vinyl pyrrolidones are preferred and are exemplified by N-vinyl pyrrolidone, N-(1-methyl-vinyl) pyrrolidone, N-vinyl-5-methyl pyrrolidone, N-vinyl-3,3-dimethylpyrrolidone, N-vinyl-5-ethyl pyrrolidone, etc.
Corrosion inhibitors, also known as anti-corrosive agents, reduce the degradation of the non-ferrous metallic parts in contact with the fluid. Illustrative of corrosion inhibitors are phosphosulfurized hydrocarbons and the products obtained by reaction of a phosphosulfurized hydrocarbon with an alkaline earth metal oxide or hydroxide, preferably in the presence of an alkylated phenol or of an alkylphenol thioether, and also preferably in the presence of carbon dioxide. As discussed hereinabove, the phosphosulfurized hydrocarbons are prepared by reacting a suitable hydrocarbon such as a terpene, a heavy petroleum fraction of a C.sub.2 to C.sub.6 olefin polymer such as polyisobutylene, with from 5 to 30 weight percent of a sulfide of phosphorous for 1/2 to 15 hours, at a temperature in the range of 150.degree. to 400.degree. F. Neutralization of the phosphosulfurized hydrocarbon may be effected in the manner taught in U.S. Pat. No. 2,969,324.
Other suitable corrosion inhibitors include copper corrosion inhibitors comprising hydrocarbylthio-disubstitutued derivatives of 1, 3, 4-thiadiazole, e.g., C.sub.2 to C.sub.30 ; alkyl, aryl, cycloalkyl, aralkyl and alkaryl-mono-, di-, tri-, or tetra- or thiodisubstituted derivatives thereof.
Representative examples of such materials included 2,5-bis(octylthio) 1,3,4-thiadiazole; 2,5-bis(octyldithio)-1,3,4-thiadiazole; 2,5-bis(octyltrithio)-1,3,4-thiadiazole; 2,5-bis(octyltetrathio)-1,3,4-thiadiazole; 2,5-bis(nonylthio)-1,3,4-thiadiazole; 2,5-bis(dodecyldithio)-1,3,4-thiadiazole; 2-dodecyldithio-5-phenyldithio-1,3,4-thiadiazole; 2,5-bis(cyclohexyl dithio)-1,3,4-thiadiazole; and mixtures thereof.
A second class of corrosion inhibitors useful in the present invention are those which include at least one benzotriazole which may be substituted or unsubstituted. Examples of suitable compounds are benzotriazole, alkyl-substituted benzotriazole (e.g., tolyltriazole, ethylbenzotriazole, hexylbenzotriazole, octylbenzotriazoles, etc.) aryl-substituted benzotriazole (e.g., phenylbenzotriazoles, etc.), an alkaryl- or aralkyl-substituted benzotriazole, and substituted benzotriazoles wherein the substituents may be, for example, hydroxy, alkoxy, halo (especially chloro), nitro, carboxy or carbalkoxy. Preferred corrosion inhibitors of this class are benzotriazole and the alkylbenzotriazoles in which the alkyl group contains 1 to about 20 carbon atoms and especially 1 to about 8 carbon atoms, most preferably benzotriazole and tolyltriazole.
The corrosion inhibitors can also be the reaction product of at least one of the above benzotriazoles with at least one amine to form a nitrogen-containing composition. The amine can be one or more monoamines or polyamines. These monoamines and polyamines can be primary amines, secondary amines or tertiary amines. The amines can be aliphatic, cycloaliphatic, aromatic, or heterocyclic, including aliphatic-substituted cycloaliphatic, aliphatic-substituted aromatic, aliphatic-substituted heterocyclic, cycloaliphatic-substituted aliphatic, cycloaliphatic-substituted aromatic, cycloaliphatic-substituted heterocyclic, aromatic-substituted aliphatic, aromatic-substituted cycloaliphatic, aromatic-substituted heterocyclic-substituted alicyclic, and heterocyclic-substituted aromatic amines and may be saturated or unsaturated. The amines may also contain non-hydrocarbon substituents or groups as long as these groups do no significantly interfere with the reaction of the amines with acylating reagents. Such non-hydrocarbon substituents or groups include lower alkoxy, lower alkyl mercapto, nitro, and interrupting groups such as --O-- and --S-- (e.g., as in such groups as --CH.sub.2 CH.sub.2 X-- CH.sub.2 CH.sub.2 -- where X is --O-- or --S--). In general, the amine may be characterized by the formula ##STR37## wherein R.sub.1, R.sub.2, and R.sub.3 are each independently hydrogen or hydrocarbyl, amino-substituted hydrocarbyl, hydroxy-substituted hydrocarbyl, alkoxy-substituted hydrocarbyl, amino, carbamyl, thiocarbamyl, guanyl and acylimidoyl groups.
With the exception of the branched polyalkylene polyamine, the polyoxyalkylene polyamines, and the high molecular weight hydrocarbyl-substituted amines described more fully hereafter, the amines ordinarily contain less than about 50 carbon atoms in total and usually not more than about 20 carbon atoms in total.
Aliphatic monoamines include mono-, di- and tri-aliphatic substituted amines wherein the aliphatic groups can be saturated or unsaturated and straight or branched chain. Such amines include, for example, mono-, di- and tri-alkyl-substituted amines; and amines having one or more N-alkenyl substituents and one N-alkyl substituents and the like. The total number of carbon atoms in these aliphatic monoamines will, as mentioned before, normally not exceed about 40 and usually not exceed about 20 carbon atoms. Specific examples of such monoamines include ethylamine, diethylamine, triethylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, allylamine, isobutylamine, cocoamine, stearylamine, laurylamine, methyllaurylamine, oleylamine, n-methyloctylamine, dodecylamine, octadecylamine, and the like. Examples of cycloaliphatic-substituted aliphatic amines, aromatic-substituted aliphatic amines, include 2-(cyclohexyl)-ethylamine, benzylamine, phenethylamine, and 3-(furyl-propyl)amine.
Cycloaliphatic monoamines are those monoamines wherein there is one cycloaliphatic substituent attached directly to the amino nitrogen though a carbon atom in the cyclic ring structure. Examples of cycloaliphatic monoamines include cyclohexylamines, cyclopentylamines, cyclohexenylamines, cyclopentenylamines, N-ethyl-cyclo-hexylamine, dicyclohexylamines, and the like. Examples of aliphatic-substituted, aromatic-substituted, and heterocyclic-substituted cycloaliphatic monoamines include propyl-substituted cyclohexylamines, phenyl-substituted cyclopentylamines and pyranyl-substituted cyclohexylamine.
Aromatic amines include those monoamines wherein a carbon atom of the aromatic ring structure is attached directly to the amino nitrogen. The aromatic ring will usually be a mononuclear aromatic ring (i.e., one derived from benzene), but can include fused aromatic rings, especially those derived from naphthalene. Examples of aromatic monoamines include aniline, di-(paramethylphenyl)amines, naphthylamine, N-n-butyl)-aniline, and the like. Examples of aliphatic-substituted, cyclo-aliphatic-substituted, and heterocyclic-substituted aromatic monoamines are para-ethoxyaniline, para-dodecylaniline, cyclohexyl-substituted naphthylamine, and thienyl-substituted aniline.
The polyamines include principally alkylene amines conforming for the most part to the formula ##STR38## wherein n is a number preferably less than about 10, each R is independently a hydrogen group or a hydrocarbyl group preferably having up to about 30 carbon atoms, and the alkylene group is preferably a lower alkylene group having less than about 8 carbon atoms. The alkylene amines include principally methylene amines, ethylene amines, butylene amines, propylene amines, pentylene amines, hexylene amines, heptylene amines, octylene amines, other polymethylene amines. They are exemplified specifically by: ethylene diamine, triethylene tetramine, propylene diamine, decamethylene diamine, octamethylene diamine, di(heptamethylene) triamine, tripropylene tetramine, tetraethylene pentamine, trimethylene diamine, pentaethylene hexamine, di(trimethylene) triamine. Higher homologous such as are obtained by condensing two or more of the above-illustrated alkylene amines likewise or useful.
The ethylene amines are especially useful. They are described in some detail under the heading "Ethylene Amines" in Encyclopedia of Chemical Technology, Kirk and Othmer, Vol. 5, pp. 898-905, Interscience Publishers, New York (1950). Such compounds are prepared most conveniently by the reaction of an alkylene chloride with ammonia. The reaction results in the product of somewhat complex mixtures of alkylene amines, including cyclic condensation products such as piperazines. These mixtures find use in the process of this invention. On the other hand, quite satisfactory products may be obtained also by the use of pure alkylene amines. An especially useful alkylene amine for reasons of economy as well as effectiveness of the products derived therefrom is a mixture of ethylene amines prepared by the reaction of ethylene chloride and ammonia and having a composition which corresponds to that of tetraethylene pentamine.
Hydoxyalkyl-substituted alkylene amines, i.e., alkylene amines having one or more hydroxyalkyl substituents on the nitrogen atoms, likewise are contemplated for use herein. Higher homologous such as are obtained by condensation of the above illustrated alkylene amines or hydroxy alkyl-substituted alkylene amines through amino radicals or through hydroxy radicals are likewise useful. It will be appreciated that condensation through amino radicals results in a higher amine accompanied with removal of ammonia and that condensation through the hydroxy radicals results in products containing ether linkages accompanied with removal of water.
The corrosion inhibitor can also be the reaction product of at least one of the above benzotriazoles with at least one nitrogen-containing ashless dispersant, such as a nitrogen-containing carboxylic dispersant, an amine dispersant or a Mannich dispersant.
The benzotriazole-amine and benzotriazole-ashless dispersant reaction products may be prepared by merely blending the reagents and allowing the reaction to proceed. The reaction may be effected in a substantially inert, normally liquid organic diluent (which may be the oil or diluent constituent of the lubricant or concentrate containing the composition of this invention) such as mineral oil, benzene, toluene, xylene, petroleum naphtha, an aliphatic ether or the like, whereupon it may take place at a temperature as low as about 15.degree. C. Ordinarily, it is preferred to carry out the reaction at temperatures of up to about 160.degree. C., with temperatures in the range of about 60.degree. C. to about 140.degree. C. being useful.
The proportions of the benzotriazole and amine or ashless dispersant used for the preparation of the reaction products useful as the above described corrosion inhibitors may vary widely. In general, it is preferred to incorporate as much of the benzotriazole as possible in an oil-dispersible medium and this can be done by using about one equivalent of amine or ashless dispersant per equivalent of benzotriazole. (The equivalent weight of the amine or ashless dispersant is its molecular weight divided by the number of basic nitrogen atoms therein, and that of the benzotriazole is its molecular weight divided by the number of triazole rings therein.) In some instances, however, it may be desirable to use more or less than one equivalent of amine or ashless dispersant per equivalent of benzotriazole.
The precise molecular structures of the benzotriazole-amine and benzotriazole-ashless dispersant reaction products are not known with certainty and are not critical. It is believed, however, that the benzotriazoles are generally more acidic than the amines or ashless dispersants and thus the compositions may comprise amine salts of the benzotriazoles.
Preferred copper corrosion inhibitors are derivatives of 1,3,4-thiadiazoles such as those described in U.S. Pat. Nos. 2,719,125, 2,719,126, and 3,087,932; especially preferred is the compound 2,5-bis(t-octyldithio)-1,3,4-thiadiazole commercially available as Amoco 150, and 2, 5-bis(t-nonyldithio)-1,3,4-thiadiazole, commercially available as Amoco 158.
The preparation of such materials is further described in U.S. Pat. Nos. 2,719,125, 2,719,126, 3,087,932, and 4,410,436, the disclosures of which are hereby incorporated by reference.
Oxidation inhibitors reduce the tendency of mineral oils to deteriorate in service which deterioration is evidenced by the products of oxidation such as sludge and varnish-like deposits on the metal surfaces and by an increase in viscosity. Such oxidation inhibitors include alkaline earth metal salts of alkylphenol thioethers having preferably C.sub.5 to C.sub.12 alkyl side chains, e.g., calcium nonylphenol sulfide, barium t-octylphenol sulfide; aryl amines, e.g., dioctylphenylamine, phenyl-alpha-naphthylamine; phosphosulfurized or sulfurized hydrocarbons, etc.
Friction modifiers serve to impart the proper friction characteristics to an ATF as required by the automotive industry.
Representative examples of suitable friction modifiers are found in U.S. Pat. No. 3,933,659, which discloses fatty acid esters and amides; U.S. Pat. No. 4,176,074, which describes molybdenum complexes of polyisobutenyl succinic anhydride-amino aklanols; U.S. Pat. No. 4,105,571, which discloses glycerol esters of dimerized fatty acids; U.S. Pat. No. 3,779,928, which discloses alkane phosphonic acid salts; U.S. Pat. No. 3,778,928, which discloses alkane phosphonic acid salts; U.S. Pat. No. 3,778,375, which discloses reaction products of a phosphonate with an oleamide; U.S. Pat. No. 3,852,205, which discloses S-carboxy-alkylene hydrocarbyl succinamic acid and mixtures thereof; U.S. Pat. No. 3,879,306, which discloses N-(hydroxyalkyl)alkenyl succinamic acids or succinimides; U.S. Pat. No. 3,932,290, which discloses reaction products of di-(lower alkyl) phosphites and epoxides; and U.S. Pat. No. 4,028,258, which discloses the alkylene oxide adduct of phosphosulfurized N-(hydroxyalkyl) alkenyl succinimides; all for use as friciton modifiers in automatic transmission fluids. The disclosures of the above patents are herein incorporated by reference. Among the more preferred friction modifiers is a class of succinate esters or metal salts thereof as described in U.S. Pat. Nos. 4,664,826 and 4,702,085, the disclosures of which are incorporated herein by reference.
Other preferred friction modifiers which may be used in combination with the phosphorous- and sulfur-containing anti-wear additives of this invention include the hydroxyl amine compounds characterized by one of the following formulas: ##STR39## wherein R.sub.8 represents H or CH.sub.3, R.sub.9 represents a C.sub.3 to C.sub.27, preferably C.sub.8 to C.sub.22, and most preferably C.sub.10 to C.sub.20 saturated or unsaturated, substituted or unsubstituted, aliphatic hydrocarbyl radical; R.sub.10 and R.sub.13 independently, represent the same or different straight or branched chain C.sub.1 to C.sub.6, preferably C.sub.2 to C.sub.4, alkylene radical; R.sub.11 and R.sub.12, independently, represent the same or different straight or branched chain C.sub.1 to C.sub.5, preferably C.sub.2 to C.sub.4 alkylene radical; R.sub.14 represents a straight or branched chain C.sub.1 to C.sub.5, preferably C.sub.2 to C.sub.3, alkylene radical; X represents O or S; p represents 0 or 1; and q, independently, represents the same or different number of from about 1 to about 4, preferably 1 to 2. In a particularly preferred embodiment, the hydroxyl amine friction modifier would be characterized by the formula VIII wherein X represents 0, R.sub.8 and R.sub.9 contain a combined total of 18 carbon atoms, R.sub.17 represents C.sub.3 alkylene, R.sub.11 and R.sub.12 represent C.sub.2 alkylene, p is 1, and each q is 1. It is preferred that the hydroxyl amine compounds contain a combined total of from about 18 to about 30 carbon atoms.
When the hydroxyl amine compounds are characterized by the formula IX and when X is O and p is 1, the hydroxyl amine compounds can be prepared, for example, by a multi-step process wherein an alkanol is first reacted, in the presence of a catalyst, with an unsaturated nitrile such as acrylonitrile to form an ether nitrile intermediate. The intermediate is then hydrogenated, preferably in the presence of a conventional hydrogenation catalyst such as platinum black or Raney nickel to form an ether amine. The ether amine is then reacted with an alkylene oxide, such as ethylene oxide in the presence of an alkaline catalyst by a conventional method at a temperature in the range of about 90.degree.-150.degree. C. The overall process for preparing the desired hydroxyl amine compounds can be illustrated by the following equations: ##STR40## where R.sub.9 represents straight or branched chain alkyl as described above and R represents hydrogen or a C.sub.1 to C.sub.3 alkyl branch of the alkylene radical constituting R.sub.10 in formula VIII.
Another method of preparing the present hydroxyl amine compounds, when X is O and p is 1, is by reacting a fatty acid with ammonia or an alkanol amine, such as ethanolamine, to form an intermediate which can be further oxyalkylated by reaction with an alkylene oxide, such as ethylene oxide or propylene oxide. A process of this type is discussed, for example, in U.S. Pat. No. 4,201,684, the disclosure of which is incorporated herein by reference.
When X is S and p is 1, the hydroxyl amine friction modifying compounds can be formed, for example, by effecting a conventional free radical reaction between a long chain alpha-olefin with a hydroxyalkyl mercaptan, such as beta-hydroxyethyl mercaptan, to produce a long chain alkyl hydroxyalkyl sulfide. The long chain alkyl hydroxyalkyl sulfide is then mixed with thionyl chloride at a low temperature and thereafter heated to about 40.degree. C. to form a long chain alkyl chloroalkyl sulfide. The long chain alkyl chloroalkyl sulfide is then caused to react with a dialkanolamine, such as diethanolamine, and, if desired, with an alkylene oxide, such as ethylene oxide, in the presence of an alkaline catalyst and at a temperature on the order of about 100.degree. C. to form the desired hydroxyl amine compounds. Processes of the above type are known in the art and are discussed, for example, in U.S. Pat. No. 3,705,139, the disclosure of which is incorporated herein by reference.
In cases when p is 0, the present hydroxyl amine friction modifiers are well known in the art and are described, for example, in U.S. Pat. Nos. 3,186,946, 4,170,560, 4,231,883, 4,409,000 and 3,711,406, the disclosures of these patents being incorporated herein by reference.
Examples of suitable hydroxyl amine compounds include but are not limited to the following
N,N-bis(2-hydroxyethyl)-n-dodecylamine
N,N-bis(2-hydroxyethyl)-1-methyl-tridecenylamine
N,N-bis(2-hydroxyethyl)-hexadecylamine
N,N-bis(2-hydroxyethyl)-octadecylamine
N,N-bis(2-hydroxyethyl)-octadecenylamine
N,N-bis(2-hydroxyethyl)-oleylamine
N,N-bis(2-hydroxyethyl)-stearylamine
N,N-bis(2-hydroxyethyl)-undecylamine
N-(2-hydroxyethyl)-N-(hydroxyethoxyethyl)-n-dodecylamine
N,N-bis(2-hydroxyethyl)-1-methyl-undecylamine
N,N-bis(2-hydroxyethoxyethoxyehtyl)-1-ethyloctadecylamine
N,N-bis(2-hydroxyethyl)-cocoamine
N,N-bis(2-hydroxyethyl)-tallowamine
N,N-bis(2-hydroxyethyl)-n-dodecyloxyethylamine
N,N-bis(2-hydroxyethyl)-lauryloxyethylamine
N,N-bis(2-hydroxyethyl)-stearyloxyethylamine
N,N-bis(2-hydroxyethyl)-n-dodecyloxypropylamine
N,N-bis(2-hydroxyethyl)-stearyloxypropylamine
N,N-bis(2-hydroxyethyl)-dodecylthioethylamine
N,N-bis(2-hydroxyethyl)-dodecylthiopropylamine
N,N-bis(2-hydroxyethyl)-hexadecylthioethylamine
N,N-bis(2-hydroxyethyl)-hexadecylthiopropylamine
N-2-hydroxyethyl,N-[N',N'-bis(2-hydroxyethyl) ethylamine]-octadecylamine
N-2-hydroxyethyl,N-[N',N'-bis(2-hydroxyethyl) ethylamine]-stearylamine
The hydroxyl amine compounds may be used as such. However they may also be used in the form of an adduct or reaction product with a boron compound, such as a boric oxide, a boron halide, a metaborate, boric acid, or a mono-, di-, or triorgano borate, such as a mono-, di-, and trialkyl borate. Such adducts or derivatives may be illustrated with reference to formula VIII, for example, by the following structural formula ##STR41## wherein R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, X, p, and q are the same as defined above, and wherein R.sub.18 is either H or a hydrocarbyl, e.g., alkyl radical.
Representative examples of alkyl borates which may be used to borate the alkanol amine compounds include mono-, di-, and tributyl borates, mono-, di-, and trihexyl borates, and the like. The borated adducts may be prepared simply by heating a mixture of the hydroxyl amine compound and the boron compound, preferably in the presence of a suitable solvent or solvents, preferably an alcoholic or hydrocarbon solvent. The presence of a solvent is not essential, however, if one is used it may be reactive or non-reactive. Suitable non-reactive solvents include benzene, toluene, xylene and the like. Suitable reactive solvents include isopropanol, butanol, the pentanols and the like. Reaction temperatures suitably may be on the order of about 100.degree. to about 280.degree. C., preferably from about 125.degree. to 175.degree. C. Reaction time is not critical and, depending on the temperature, etc., it may vary from about 1-2 hours up to about 15 hours, e.g., 2 to 6 hours until the desired amount of water is removed. Suitable boration procedures and materials contemplated within the scope of R.sub.18 are well known in the art and are described, for example, in U.S. Pat. Nos. 4,382,006, 4,400,284, 4,529,528, 4,594,171, and 4,595,514, the disclosures of which are incorporated herein by reference.
Dispersants maintain oil insolubles, resulting from oxidation during use, in suspension in the fluid thus preventing sludge flocculation and precipitation. Suitable dispersants include, for example, dispersants of the ash-producing or ashless type, the latter type being preferred.
The ash-producing detergents are exemplified by oil-soluble neutral and basic salts of alkali or alkaline earth metals with sulfonic acids, carboyxlic acids, or organic phosphorus acids characterized by at least one direct carbon-to-phosphorus linkage such as those prepared by the treatment of an olefin polymer (e.g., polyisobutene having a molecular weight of 1,000) with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride. The most commonly used salts of such acids are those of sodium, potassium, lithium, calcium, magnesium, strontium and barium.
The term "basic salt" is used to designate metal salts wherein the metal is present in stoichimetrically larger amounts than the organic acid radical. The commonly employed methods for preparing the basic salts involve heating a mineral oil solution of an acid with a stoichiometric excess of a metal neutralizing agent such as the metal oxide, hydroxide, carbonate, bicarbonate, or sulfide at a temperature of about 50.degree. C. and filtering the resulting mass. The use of a "promoter" in the neutralization step to aid the incorporation of a large excess of metal likewise is know. Examples of compounds useful as the promoter include phenolic substance such as phenol, naphthol, alkylphenol, thiophenol, sulfurized alkylphenol, and condensation products of formaldehyde with a phenolic substance; alcohols such as methanol, 2-propanol, octyl alcohol, cellosolve, ethylene glycol, stearyl alcohol, and cyclohexyl alcohol; and amines such as aniline, phenylenediamine, phenyl-beta-naphthylamine, and dodecylamine. A particularly effective method for preparing the basic salts comprises mixing an acid with an excess of a basic alkaline earth metal neutralizing agent and a least one alcohol promoter, and carbonating the mixture at an elevated temperature such as 60.degree.-200.degree. C. This class of materials is discussed further hereinabove in connection with detergents and metal rust inhibitors.
The most preferred ash-producing detergents include the metal salts of sulfonic acids, alkyl phenols, sulfurized alkyl phenols, alkyl salicylates, naphthenates and other oil soluble mono- and dicarboxylic acids. Highly basic (viz, overbased) metal salts, such as highly basic alkaline earth metal sulfonates (especially Ca and Mg salts) are frequently used as detergents. They are usually produced by heating a mixture comprising an oil-soluble sulfonate or alkaryl sulfonic acid, with an excess of alkaline earth metal compound above that required for complete neutralization of any sulfonic acid present, and thereafter forming a dispersed carbonate complex by reacting the excess metal with carbon dioxide to provide the desired overbasing. The sulfonic acids are typically obtained by the sulfonation of alkyl substituted aromatic hydrocarbons such as those obtained from the fractionation of petroleum by distillation and/or extraction or by the alkylation of aromatic hydrocarbons as for example those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl and the halogen derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene. The alkylation may be carried out in the presence of a catalyst with alkylating agents having from about 3 to more than 30 carbon atoms such as for example haloparaffins, olefins that may be obtained by dehydrogenation of paraffins, polyolefins as for example polymers from ethylene, propylene, etc. The alkaryl sulfonates usually contain from about 9 to about 70 more carbon atoms, preferably from about 16 to about 50 carbon atoms per alkyl substituted aromatic moiety.
The alkaline earth metal compounds which may be used in neutralizing these alkaryl sulfonic acids to provide the sulfonates includes the oxides and hydroxides, alkoxides, carbonates, carboxylate, sulfide, hydrosulfide, nitrate, borates and ethers of magnesium, calcium, and barium. Examples are calcium oxide, calcium hydroxide, magnesium acetate and magnesium borate. As noted, the alkaline earth metal compound is used in excess of that required to complete neutralization of the alkaryl sulfonic acids. Generally, the amount ranges from about 100 to about 220%, although it is preferred to use at least 125%, of the stoichiometric amount of metal required for complete neutralization.
Various other preparations of basic alkaline earth metal alkaryl sulfonates are known, such as those described in U.S. Pat. Nos. 3,150,088 and 3,150,089, wherein overbasing is accomplished by hydrolysis of an alkoxide-carbonate complex with the alkaryl sulfonate in a hydrocarbon solvent/diluent oil.
Ashless dispersants, which are the preferred dispersant for use in connection with this invention, are so called despite the fact that, depending on their constitution, the dispersant may upon combustion yield a non-volatile material such as boric oxide or phosphorus pentoxide; however, they ordinarily do not contain metal and therefore do not yield a metal-containing ash on combustion. Many types of ashless dispersants are known in the art, and any of them are suitable for use in the lubricant compositions of this invention. The following are illustrative:
1. Reaction products of carboxylic acids (or derivatives thereof) containing at least about 30 and preferably at least about 50 carbon atoms with nitrogen containing compounds such as amine, organic hydroxy compounds such as phenols and alcohols, and/or basic inorganic materials. Examples of these "carboxylic dispersants" are described, for example, in British Patent No. 1,306,529 and in U.S. Pat. Nos. 3,272,746, 3,341,542, 3,454,607 and 4,654,403.
More, specifically, nitrogen- or ester-containing ashless dispersants comprise members selected from the group consisting of oil soluble salts, amides, imides, oxazolines and esters, or mixtures thereof, of long chain hydrocarbyl-substituted mono- and dicarboxylic acids or anhydride or ester derivatives thereof wherein said long chain hydrocarbyl group is a polymer, typically of a C.sub.2 to C.sub.10, e.g., C.sub.2 to C.sub.5, monoolefin, said polymer having a number average molecular weight of from about 700 to 5000.
The long chain hydrocarbyl-substituted dicarboxylic acid material which can be used to make the dispersant includes the reaction product of long chain hydrocarbon polymer, generally a polyolefin, with (i) monounsaturated C.sub.4 to C.sub.10 dicarboxylic acid wherein (a) the carboxyl groups are vicinyl, (i.e. located on adjacent carbon atoms) and (b) at least one, preferably both, of said adjacent carbon atoms are part of said mono unsaturation; or with (ii) derivatives of (i) such as anhydrides or C.sub.1 to C.sub.5 alcohol derived mono- or diesters of (i). Upon reaction with the hydrocarbon polymer, the monounsaturation of the dicarboxylic acid material becomes saturated. Thus, for example, maleic anhydride becomes a hydrocarbyl-substituted succinic anhydride.
Typically, from about 0.7 to about 4.0 (e.g., 0.8 to 2.6), preferably from about 1.0 to about 2.0, and most preferably from about 1.1 to about 1.7 moles of said unsaturated C.sub.4 to C.sub.10 dicarboxylic acid material are charged to the reactor per mole of polyolefin charged.
Normally, not all of the polyolefin reacts with the unsaturated acid or derivative and the hydrocarbyl-substituted dicarboxylic acid material will contain unreacted polyolefin. The unreacted polyolefin is typically not removed from the reaction mixture (because such removal is difficult and would be commercially infeasible) and the product mixture, stripped of any unreacted monounsaturated C.sub.4 to C.sub.10 dicarboxylic acid material, is employed for further reaction with the amine or alcohol as described hereinafter to make the dispersant.
Characterization of the average number of moles of dicarboxylic acid, anydride or ester which have reacted per mole of polyolefin charged to the reaction (whether it has undergone reaction or not) is defined herein as functionality. Said functionality is based upon (i) determination of the saponification number of the resulting product mixture using potassium hydroxide; and (ii) the number average molecular weight of the polymer charged using techniques well known in the art. Functionality is defined solely with reference to the resulting product mixture. Consequently, although the amount of said reacted polyolefin contained in the resulting product mixture can be subsequently modified, i.e., increased or decreased by techniques known in the art, such modifications do not alter functionality as defined above. The term hydrocarbyl-substituted dicarboxylic acid material is intended to refer to the product mixture whether it has undergone such modification or not.
Accordingly, the functionality of the hydrocarbyl-substituted dicarboxylic acid material will be typically at least about 0.5, preferably at least about 0.8, and most preferably at least about 0.9, and can vary typically from about 0.5 to about 2.8 (e.g., 0.6 to 2), preferably from about 0.8 to about 1.4, and most preferably from about 0.9 to about 1.3.
Exemplary of such unsaturated mono and dicarboxylic acids, or anhydrides and esters thereof are fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, chloromaleic anhydride, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, etc.
Preferred olefin polymers for reaction with the unsaturated dicarboxylic acids or derivatives thereof are polymers comprising a major molar amount of C.sub.2 to C.sub.10, e.g., C.sub.2 to C.sub.5 monoolefin. Such olefins include ethylene, propylene, butylene, isobutylene, pentene, octene-1, styrene, etc. The polymers can be homopolymers such as polyisobutylene, as well as copolymers of two or more of such olefins such as copolymers of: ethylene and propylene; butylene and isobutylene; propylene and isobutylene; etc. Other copolymers include those in which a minor molar amount of the copolymer monomers, e.g., 1 to 10 mole %, is a C.sub.4 to C.sub.18 non-conjugated diolefin, e.g., a copolymer of isobutylene and butadiene: or a copolymer of ethylene, propylene and 1,4-hexadiene; etc.
In some cases, the olefin polymer may be completely saturated, for example an ethylene-propylene copolymer made by a Ziegler-Natta synthesis using hydrogen as a moderator to control molecular weight.
The olefin polymers used in the dispersants will usually have number average molecular weights within the range of about 700 and about 5,000, more usually between about 800 and about 3000. Particularly useful olefin polymers have number average molecular weights within the range of about 900 and about 2500 with approximately one terminal double bond per polymer chain. An especially useful starting material for highly potent dispersant additives is polyisobutylene. The number average molecular weight for such polymers can be determined by several known techniques. A convenient method for such determination is by gel permeation chromatography (GPC) which additionally provides molecular weight distribution information, see W. W. Yau, J. J. Kirkland and D. D. Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979.
Processes for reacting the olefin polymer with the C.sub.40-10 unsaturated dicarboxylic acid, anhydride or ester are known in the art. For example, the olefin polymer and the dicarboxylic acid or derivative may be simply heated together as disclosed in U.S. Pat. Nos. 3,361,673 and 3,401,118 to cause a thermal "ene" reaction to take place. Or, the olefin polymer can be first halogenated, for example, chlorinated or brominated to about 1 to 8 wt. %, preferably 3 to 7 wt. % chlorine, or bromine, based on the weight of polymer, by passing the chlorine or bromine through the polyolefin at a temperature of 60.degree. to 250.degree. C., e.g., 120.degree. to 160.degree. C., for about 0.5 to 10, preferably 1 to 7 hours. The halogenated polymer may then be reacted with sufficient unsaturated acid or derivative at 100.degree. to 250.degree. C., usually about 180.degree. to 235.degree. C., for about 0.5 to 10, e.g., 3 to 8 hours, so the product obtained will contain the desired number of moles of the unsaturated acid or derivative per mole of the halogenated polymer. Processes of this general type are taught in U.S. Pat. Nos. 3,087,936, 3,172,892, 3,272,746 and others.
Alternatively, the olefin polymer, and the unsaturated acid or derivative are mixed and heated while adding chlorine to the hot material. Processes of this type are disclosed in U.S. Pat. Nos. 3,215,707, 3,231,587, 3,912,764, 4,110,349, and in U.K. 1,440,219.
By the use of halogen, about 65 to 95 wt. % of the polyolefin, e.g., polyisobutylene will normally react with the dicarboxylic acid or derivative. Upon carrying out a thermal reaction without the use of halogen or a catalyst, then usually only about 50 to 75 wt. % of the polyisobutylene will react. Chlorination helps increase the reactivity.
At least one hydrocarbyl-substituted dicarboxylic acid material is mixed with at least one of amine, alcohol, including polyol, aminoalcohol, etc., to form the dispersant additives. When the acid material is further reacted, e.g., neutralized, then generally a major proportion of at least 50 percent of the acid producing units up to all the acid units will be reacted.
Amine compounds useful as nucleophilic reactants for neutralization of the hydrocarbyl-substituted dicarboxylic acid materials include mono- and (preferably) polyamines, most preferably polyalkylene polyamines, of about 2 to 60, preferably 2 to 40 (e.g., 3 to 20), total carbon atoms and about 1 to 12, preferably 3 to 12, and most preferably 3 to 9 nitrogen atoms in the molecule. These amines may be hydrocarbyl amines or may be hydrocarbyl amines including other groups, e.g, hydroxy groups, alkoxy groups, amide groups, nitriles, imidazoline groups, and the like. Hydroxyl amines with 1 to 6 hydroxy groups, preferably 1 to 3 hydroxy groups are particularly useful. Preferred amines are aliphatic saturated amines, including those of the general formulas: ##STR42## wherein R, R', R'' and R''' are independently selected from the group consisting of hydrogen; C.sub.1 to C.sub.25 straight or branched chain alkyl radicals; C.sub.1 to C.sub.12 alkoxy C.sub.2 to C.sub.6 alkylene radicals; C.sub.2 to C.sub.12 hydroxy amino alkylene radicals; and C.sub.1 to C.sub.12 alkylamino C.sub.2 to C.sub.6 alkylene radicals; and wherein R''' can additionally comprise a moiety of the formula: ##STR43## wherein R' is as defined above, and wherein s and s' can be the same or a different number of from 2 to 6, preferably 2 to 4; and t and t' can be the same or different and are numbers of from 0 to 10, preferably 2 to 7, and most preferably about 3 to 7, with the proviso that the sum of t and t' is not greater than 15. To assure a facile reaction, it is preferred that R, R', R'', R''', s, s', t and t' be selected in a manner sufficient to provide the compounds of formulas XVI and XVII with typically at least one primary or secondary amine group, preferably at least two primary or secondary amine groups. This can be achieved by selecting at least one of said R, R', R'' or R''' groups to be hydrogen or by letting t in formula XVII be at least one when R'' ' is H or when the moiety of formula XVIII possesses a secondary amino group. The most preferred amine of the above formulas are represented by formula XVII and contain at least two primary amine groups and at least one, and preferably at least three, secondary amine groups.
Non-limiting examples of suitable amine compounds include: 1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane; 1,6-diaminohexane; polyethylene amines such as diethylene triamine; triethylene tetramine; tetraethylene pentamine; polypropylene amines such as 1,2- propylene diamine; di-(1,2-propylene)triamine; di-(1,3- propylene) triamine; N,N-dimethyl-1,3-diaminopropane; N,N- di-(2-aminoethyl) ethylene diamine; N,N-di(2-hydroxyethyl)-1,3-propylene diamine; 3-dodecyloxypropylamine; N-dodecyl- 1,3-propane diamine; trishydroxymethylaminomethane (THAM); diisopropanol amine; diethanol amine; triethanol amine; mono-, di-, and tri-tallow amines; amino morpholines such as N-(3-aminopropyl)morpholine; and mixtures thereof.
Other useful amine compounds include: alicyclic diamines such as 1,4-di(aminomethyl) cyclohexane, and heterocyclic nitrogen compounds such as imidazolines, and N-aminoalkyl piperazines of the general formula XIX: ##STR44## wherein p.sub.1 and p.sub.2 are the same or different and are each integers of from 1 to 4, and n.sub.1, n.sub.2 and n.sub.3 are the same or different and are each integers of from 1 to 3. Non-limiting examples of such amines include 2-pentadecyl imidazoline; N-(2-aminoethyl) piperazine; etc. Commercial mixtures of amine compounds may advantageously be used. For example, one process for preparing alkylene amines involves the reaction of an alkylene dihalide (such as ethylene dichloride or propylene dichloride) with ammonia, which results in a complex mixture of alkylene amines wherein pairs of nitrogens are joined by alkylene groups, forming such compounds as diethylene triamine, triethylenetetramine, tetraethylene pentamine and isomeric piperazines. Low cost poly(ethyleneamines) compounds averaging about 5 to 7 nitrogen atoms per molecule are available commercially under trade names such as "Polyamine H", "Polyamine 400", "Dow Polyamine E-300", etc.
Useful amines also include polyoxyalkylene polyamines such as those of the formulas: ##STR45## where m has a value of about 3 to 70 and preferably 10 to 35; and ##STR46## where n has a value of about 1 to 40 with the provision that the sum of all the n's is from about 3 to about 70 and preferably from about 6 to about 35, and R is a polyvalent saturated hydrocarbon radical of up to ten carbon atoms wherein the number of substituents on the R group is represented by the value of a, which is a number of from 3 to 6. The alkylene groups in either formula XX or XXI may be straight or branched chains containing about 2 to 7, and preferably about 2 to 4 carbon atoms.
The polyoxyalkylene polyamines of formulas XX or XXI above, preferably polyoxyalkylene diamines and polyoxyalkylene triamines, may have average molecular weights ranging from about 200 to about 4000, and preferably from about 400 to about 2000. The preferred polyoxyalkylene polyamines include the polyoxyethylene and polyoxypropylene diamines and the polyoxypropylene triamines having average molecular weights ranging from about 200 to 2000. The polyoxyalkylene polyamines are commercially available and may be obtained, for example, from the Jefferson Chemical Company, Inc. under the trade name "Jeffamines D-230, D-400, D-1000, D- 2000, T-403", etc.
The amine is readily reacted with the selected hydrocarbyl-substituted dicarboxylic acid material, e.g., alkenyl succinic anhydride, by heating an oil solution containing 5 to 95 wt. % of said hydrocarbyl-substituted dicarboxylic acid material to about 100.degree. to 250.degree. C., preferably 125.degree. to 175.degree. C., generally for 1 to 10, e.g., 2 to 6 hours until the desired amount of water is removed. The heating is preferably carried out to favor formation of imides or mixtures of imides and amides, rather than amides and salts. Reaction ratios of hydrocarbyl-substituted dicarboxylic acid material to equivalents of amine as well as the other nucleophilic reactants described herein can vary considerably, depending on the reactants and type of bonds formed. Generally from 0.1 to 1.0, preferably from about 0.2 to 0.6, e.g., 0.4 to 0.6, equivalents of dicarboxylic acid unit content (e.g., substituted succinic anhydride content) is used per reactive equivalent of nucleophilic reactant, e.g., amine. For example, about 0.8 mole of a pentamine (having two primary amino groups and five reactive equivalents of nitrogen per molecule) is preferably used to convert into a mixture of amides and imides, a composition, having a functionality of 1.6, derived from reaction of polyolefin and maleic anhydride; i.e., preferably the pentamine is used in an amount sufficient to provide about 0.4 equivalents (that is, 1.6 divided by (0.8.times.5) equivalents) of succinic anhydride units per reactive nitrogen equivalent of the amine.
The ashless dispersant esters are derived from reaction of the aforesaid long chain hydrocarbyl-substituted dicarboxylic acid material and hydroxy compounds such as monohydric and polyhydric alcohols or aromatic compounds such as phenols and naphthols, etc. The polyhydric alcohols are the most preferred hydroxy compound and preferably contain from 2 to about 10 hydroxy radicals, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and other alkylene glycols in which the alkylene radical contains from 2 to about 8 carbon atoms. Other useful polyhydric alcohols include glycerol, monooleate of glycerol, monostearate of glycerol, monomethyl ether of glycerol, pentaerythritol, dipentaerythritol, and mixtures thereof.
The ester dispersant may also be derived from unsaturated alcohols such as allyl alcohol, cinnamyl alcohol, propargyl alcohol, 1-cyclohexane-3-ol, and oleyl alcohol. Still other classes of the alcohols capable of yielding the esters of this invention comprise the ether alcohols and amino alcohols including, for example, the oxyalkylene-, oxyarylene-, aminoalkylene-, and aminoarylene-substituted alcohols having one or more oxyalkylene, oxyarylene, aminoalkylene or aminoarylene radicals. They are exemplified by Cellosolve, Carbitol, N,N,N',N'-tetrahydroxy-trimethylene diamine, and ether alcohols having up to about 150 oxyalkylene radicals in which the alkylene radical contains from 1 to about 8 carbon atoms.
The ester dispersant may be diesters of succinic acids or acidic esters, i.e., partially esterified succinic acids; as well as partially esterified polyhydric alcohols or phenols, i.e., esters having free alcohols or phenolic hydroxyl radicals. Mixtures of the above illustrated esters likewise are contemplated within the scope of this invention.
The ester dispersant may be prepared by one of several known methods as illustrated for example in U.S. Pat. Nos. 3,381,022 and 3,836,471.
Hydroxy amines which can be reacted with the aforesaid long chain hydrocarbyl-substituted dicarboxylic acid materials to form dispersants include 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, p-(beta-hydroxyethyl)-aniline, 2-amino-1-propanol, 3-amino-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, N-(beta-hydroxypropyl)-N'-(beta-aminoethyl)-piperazine, tris(hydroxymethyl) aminomethane (also known as trismethylolaminomethane), 2-amino-1-butanol, ethanolamine, beta-(beta-hydroxyethoxy)ethylamine, and the like. Mixtures of these or similar amines can also be employed. The above description of nucleophilic reactants suitable for reaction with the hydrocarbyl-substituted dicarboxylic acid material includes amines, alcohols, and compounds of mixed amine and hydroxy containing reactive functional groups, i.e., aminoalcohols.
A preferred group of ashless dispersants are those derived from polyisobutylene substituted with succinic anhydride groups and reacted with said polyethylene amines, e.g., tetraethylene pentamine, pentaethylene hexamine, polyoxyethylene and polyoxypropylene amines, e.g., polyoxypropylene diamine, trismethylolaminomethane, or said above-described alcohols such as pentaerythritol, and combinations thereof. One class of particularly preferred dispersants includes those derived from polyisobutene substituted with succinic anhydride groups and reacted with (i) a hydroxy compound, e.g., pentaerythritol, (ii) a polyoxyalkylene polyamine, e.g., polyoxypropylene diamine, and/or (iii) a polyalkylene polyamine, e.g., polyethylene diamine or tetraethylene pentamine. Another preferred dispersant class includes those derived from polyisobutenyl succinic anhydride reacted with (i) a polyalkylene polyamine, e.g., tetraethylene pentamine, and/or (ii) a polyhydric alcohol or polyhydroxy-substituted aliphatic primary amine, e.g., pentaerythritol or trismethylolaminomethane.
2. Reaction products of relatively high molecular weight aliphatic or alicyclic halides with amines, preferably polyalkylene polyamines. These may be characterized as "amine dispersants" and examples thereof are described for example, in the U.S. Pat. Nos. 3,275,554, 3,454,555 and 3,565,804.
3. Reaction products of alkyl phenols in which the alkyl group contains at least about 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines), which may be characterized as "Mannich dispersants." The materials described in the following U.S. Patents are illustrative:
U.S. Pat. No. 3,725,480
U.S. Pat. No. 3,726,882
U.S. Pat. No. 3,980,569
4. Products obtained by post-treating the carboxylic, amine or Mannich dispersants with such reagents as urea, thiourea, carbon disulfide, phosphosulfurized hydrocarbons, aldehydes, ketones, carboxylic acids, hydrocarbon-substitued succinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds or the like. Exemplary materials of this type are described in the following U.S. Patents:
U.S. Pat. No. 2,805,217
U.S. Pat. No. 3,087,936
U.S. Pat. No. 3,254,025
U.S. Pat. No. 3,394,179
U.S. Pat. No. 3,511,780
U.S. Pat. No. 3,703,536
U.S. Pat. No. 3,704,308
U.S. Pat. No. 3,708,422
U.S. Pat. No. 3,850,822
U.S. Pat. No. 4,113,639
U.S. Pat. No. 4,116,876
More specifically, the nitrogen and ester containing dispersants preferably are further treated by boration as generally taught in U.S. Pat. Nos. 3,087,936 and 3,254,025 (incorporated herein by reference). This is readily accomplished by treating the selected nitrogen dispersant with a boron compound selected from the class consisting of boron oxide, boron halides, boron acids and esters of boron acids in an amount to provide from about 0.1 atomic proportion of boron for each mole of said nitrogen dispersant to about 20 atomic proportions of boron for each atomic proportion of nitrogen of said nitrogen dispersant. Usefully borated dispersants contain from about 0.05 to 2.0 wt. %, e.g., 0.05 to 0.7 wt. % boron based on the total weight of said borated nitrogen dispersant. The boron, which appears to be in the product as dehydrated boric acid polymers (primarily (HBO.sub.2).sub.3), is believed to attach to the dispersant imides and diimides as amine salts, e.g., the metaborate salt of said diimide. Treating is readily carried out by adding from about 0.05 to 4, e.g., 1 to 3 wt. % (based on the weight of said nitrogen dispersant) of said boron compound, preferably boric acid which is most usually added as a slurry to said nitrogen dispersant and heating with stirring at from about 135.degree. to 190.degree. C., e.g., 140.degree.-170.degree. C., for from 1 to 5 hours followed by nitrogen stripping at said temperature ranges. Or, the boron treatment can be carried out by adding boric acid to the hot reaction mixture of the dicarboxylic acid material and amine while removing water.
5. Interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., aminoalkyl acrylates or acrylamides and poly-(oxyethylene)-substituted acrylates. These may be characterized as "polymeric dispersants" and examples thereof are disclosed in the following U.S. Patents:
U.S. Pat. No. 3,329,658
U.S. Pat. No. 3,519,565
U.S. Pat. No. 3,666,730
U.S. Pat. No. 3,702,300
All of the above-noted patents are incorporated by reference herein for their disclosures of ashless dispersants.
Lubricating oil flow improvers (LOFI) include all those additives which modify the size, number, and growth of wax crystals in lube oils in such a way as to impart improved low temperature handling, pumpability, and/or vehicle operability as measured by such tests as pour point and mini rotary viscometry (MRV). The majority of lubricating oil flow improvers are polymers or contain polymers. These polymers are generally of two types, either backbone or sidechain.
The backbone variety, such as the ethylene-vinyl acetates (EVA), have various lengths of methylene segments randomly distributed in the backbone of the polymer, which associate or cocrystallize with the wax crystals inhibiting further crystal growth due to branches and non-crystalizable segments in the polymer.
The sidechain type polymers, which are the predominant variety used as LOFI's, have methylene segments as the side chains, preferably as straight side chains. These polymers work similarly to the backbone type except the side chains have been found more effective in treating isoparaffins as well as n-paraffins found in lube oils. Representative of this type of polymer are C.sub.8 -C.sub.18 dialkylfumarate/vinyl acetate copolymers, polyacrylates, polymethacrylates, and esterified styrene-maleic anhydride copolymers.
Foam control can be provided by an anti-foamant of the polysiloxane type, e.g., silicone oil and polydimethyl siloxane.
Anti-wear agents, as their name implies, reduce wear of moving metallic parts. Representative of conventional anti-wear agents which may be used to supplement the present phosphorous- and sulfur-containing reaction product mixture are the zinc dialkyl dithiophosphates, and the zinc diaryl dithiophosphates. However, it is an important advantage of the present invention that supplemental anti-wear agents do not have to be employed and, in fact, can be excluded from the compositions of this invention.
Seal swellants include mineral oils of the type that provoke swelling, including aliphatic alcohols of 8 to 13 carbon atoms such as tridecyl alcohol, with a preferred seal swellant being characterized as an oil-soluble, saturated, aliphatic or aromatic hydrocarbon ester of from 10 to 60 carbon atoms and 2 to 4 linkages, e.g., dihexyl phthalate, as are described in U.S. Pat. No. 3,974,081.
Some of these numerous additives can provide a multiplicity of effects e.g., a dispersant oxidation inhibitor. This approach is well known and need not be further elaborated herein.
Compositions, when containing these additives, typically are blended into the base oil in amounts which are effective to provide their normal attendant function. Representative effective amounts of such additives are illustrated as follows:
______________________________________ (Broad) (Preferred)Compositions Wt % Wt %______________________________________V.I. Improver 1-12 1-4Corrosion Inhibitor 0.01-3 0.01-1.5Oxidation inhibitor 0.01-5 0.01-1.5Dispersant 0.1-10 0.1-5Lube Oil Flow Improver 0.01-2 0.01-1.5Detergents and Rust 0.01-6 0.01-3InhibitorsAnti-Foaming Agents 0.001-0.1 0.001-0.01Anti-wear Agents 0.001-5 0.001-1.5Seal Swellant 0.1-8 0.1-4Friction Modifiers 0.01-3 0.01-1.5Lubricating Base Oil Balance Balance______________________________________
In broad sense therefore, the phosphorous- and sulfur-containing reaction product mixture additive of the present invention, when employed in a lubricating oil composition, typically in a minor amount, is effective to impart at least one of enhanced anti-wear and anti-oxidant, relative to the same composition in the absence of the present additive. Additional conventional additives, particularly dispersants and friction modifiers, selected to meet the particular requirements of a selected type of lubricating oil composition also can be included as desired.
Accordingly, while any effective amount of the phosphorous- and sulfur-containing mixed reaction product additive can be incorporated into a lubricating oil composition, it is contemplated that such effective amount be sufficient to provide a given composition with an amount of the additive of typically from about 0.01 to about 25, preferably from about 0.1 to about 5.0, and most preferably from about 0.5 to about 1.0 wt.%, based on the weight of said composition. Similarly, while any effective amount of a friction modifier additive can be incorporated into an oil composition, it is contemplated that such effective amount be sufficient to provide said composition with an amount of the friction modifier additive of typically from about 0.05 to about 1, preferably from about 0.08 to about 0.8 and most preferably from about 0.1 to about 0.50 wt.%, based on the weight of said composition, and it is contemplated that an effective amount of the a dispersant material typically will be in the range of from about 1 to about 10, preferably from 2 to about 8, and most preferably from 3 to about 6 wt.% based on the weight of the composition.
When other additives are employed, it may be desirable, although not necessary, to prepare additive concentrates comprising concentrated solutions or dispersions of the present phosphorous- and sulfur-containing reaction product mixture, together with the other additives (said concentrate additive mixture being referred to herein as an additive package) whereby the several additives can be added simultaneously to the base oil to form the lubricating oil compositions. Dissolution of the additive concentrate into the lubricating oil may be facilitated by solvents and by mixing accompanied with mild heating, but this is not essential. The concentrate or additive package typically will be formulated to contain the phosporus- and sulfur-containing reaction product mixture of this invention and optional additional additives in proper amounts to provide the desired concentration in the final formulation when the additive package is combined with a predetermined amount of base lubricant. Thus, the phosporus- and sulfur-containing reaction product mixture of this invention can be added to small amounts of base oil or, optionally, to other compatible solvents, along with other desirable additives to form concentrates containing active ingredients in collective amounts of typically from about 25 to about 100, and preferably from about 65 to about 95, and most preferably from about 75 to about 90 wt.% additives in the appropriate proportions, with the remainder being base oil.
The final formulation may employ typically about 10 wt. % of the additive package with the remainder being base oil.
All of said weight percents expressed herein are based on active ingredient (a.i.) content of the additive, and/or upon the total weight of any additive package, or formulation which will be the sum of the a.i. weight of each additive plus the weight of total oil or diluent.
The use of the present phosphorous- and sulfur-containing anti-wear additives permit the formulator to flexibly tailor an ATF in order to achieve the balance of properties required under today's more stringent transmission manufacturers specifications.
The following examples are given as specific illustrations of the claimed invention. It should be understood, however, that the invention is not limited to the specific details set forth in the examples. All parts and percentages in the examples as well as in the remainder of the specification and claims are by weight unless otherwise specified.
EXAMPLE 1C (Comparative)
A phosphorous- and sulfur-containing reaction product mixture was prepared at atmospheric pressure by adding to a stainless steel reactor 135.55 parts of tributyl phosphite, 132.0 parts of hydroxyethyl-n-dodecyl sulfide, 66.1 parts of thiobisethanol, and 0.054 parts of sodium methoxide. The reaction was equipped with internal heating and cooling cools, a reflux condenser, a knock-out pot and vacuum capabilities, for stripping operations. The reactor was also equipped with a mixer and a nitrogen sparger. The reactor was charged over a period of 2.0 hours. The reactor was then sealed and flushed with nitrogen, and the contents thereof was heated to 110.degree. C over a period of 1.5 hours. The reaction temperature was maintained at 110.degree.-115.degree. C. until total acid number (TAN) analysis indicated a TAN of 92.1. This continued heating (soaking) took about 9.0 hours. Heating was then discontinued and the reaction mixture was cooled to 90.degree. C. and vacuum stripped of the butyl alcohol which formed as a by-product during the reaction by means of a nitrogen sweep. The stripping step was continued for 14.8 hours, after which the reaction mixture was cooled to 40.degree. C., 33.45 parts of tridecyl alcohol was added (blendback) and the product was pumped from the reactor. The cooldown took about 2.5 hours, and the pumpout took about 3.0 hours. The total process thus took 32.8 hours.
The product was analyzed using .sup.13 C NMR spectral analysis and it was found to contain 53.0 mole % of sulfur-containing thioether species, 24.6 mole % of phosphite ester species, 18.6 mole % of alcohol species, and 7.8 mole % of other species.
All .sup.13 C measurements were taken on a JEOL GSX-400 NMR Spectrometer operating at 100.40 MHz. The samples were prepared to be between 20 and 30% wt/wt in CDCl.sub.3. A standard single pulse experiment was used with a 90.degree. flip angle, and preacquisition delay 4 sec. Broadband proton decoupling was gated off during preacquisition and evolution and on throughout data acquisition.
Chemical shifts reported are internally referenced to deuterochloroform. The spectral observation window was selected to be 24038.5 Hz with 16K data points per scan. All FFTs were done with a 4 Hz gaussian line broadening multiplication prior to transformation. Integral intensities were digitally measured and the values were reported in mole percents.
The product was also analyzed using 31P NMR spectral analysis and it was found that the phosphite ester species contained 0.7 mole % of the species designated as formula XIII above, 7.9 mole % of the species designated as formula XIV, 55.4 mole % of the species designated as formula XI, 31 mole % of the species designated as formula XII, and 4.9 mole % "other". The resulting reaction product was found to contain 4.8 wt % phosphorous and 9.11 wt. % sulfur and existed as a single phase mixture.
EXAMPLES 2C-5C
The procedure of EXAMPLE 1C was repeated except that the amounts of reactants were varied slightly, as were the charge, preheat, soak, strip, cooldown and pumpout times. The results of EXAMPLES 2C-5C (as well as 1C) are set forth in Tables 3, 4 and 5 below.
TABLE 3______________________________________CHARGE, EXAMPLE NO.parts by wt. 1C 2C 3C 4C 5C______________________________________tributyl phosphite 135.55 133.10 127.00 142.10 117.70hydroxyethyl-n- 132.80 135.10 120.10 133.20 116.82dodecyl sulfidethiobisethanol 66.10 65.95 59.60 66.00 57.60sodium methoxide .054 .057 .050 .050 .040tridecyl alcohol 33.45 33.30 15.80 24.14 8.15waste butyl alcohol 19.30 18.32 14.66 24.13 10.19ANALYSISwt. % phosphorous 4.8 4.7 5.1 5.0 4.9wt. % sulfur 9.11 10.4 10.2 10.2 10.5total acid number 92.1 88.0 85.0 90.6 84.4(TAN) mg KOH/gm______________________________________
TABLE 4______________________________________ EXAMPLE NO. 1C 2C 3C 4C 5C______________________________________.sup.13 C NMR (mole %)sulfur-containing 53.0 56.1 52.4 54.5 57.5thioethersphosphorous- 24.6 21.5 28.6 27.3 26.5containing estersalcohol 18.6 17.8 19.0 18.2 13.8other 7.8 5.4 0 0 2.2.sup.31 P NMR (mole %)tributyl phosphite 0 0 0 0 0Productrepresented by:formula XI 55.4 56.1 63.2 59.5 53.9formula XII 31.0 31.8 22.7 23.9 31.6formula XIII 0.7 0.7 0.6 0.6 0formula XIV 7.9 6.8 8.6 8.6 8.6other 4.9 4.7 5.0 7.4 5.9______________________________________
TABLE 5______________________________________ EXAMPLE NO.process step, hrs. 1C 2C 3C 4C 5C______________________________________charge 2.0 3.0 0.8 2.0 0.8heat to 110.degree. C. 1.5 0.5 1.5 1.0 1.0soak at 110-115.degree. C. 9.0 8.5 11.5 11.5 11.5stripping butyl 14.0 19.0 10.0 4.3.sup.1 3.5.sup.1alcoholblendback/cooldown 2.5 1.3 1.3 1.3 3.0pumpout 3.0 1.0 2.0 2.3 2.3total cycle time 32.8 33.3 27.0 22.3.sup.1 22.0.sup.1reactor pressure ATMOSPHERIC______________________________________ .sup.1 stripping was conducted at elevated temperature (115.degree. C.) t reduce strip time, and therefor the total cycle time.
EXAMPLES 6-11
The general procedure of EXAMPLE 1C was followed, except that the reaction step (heat soak) was conducted under a reduced pressure of -60 KPa, and the separate stripping step was eliminated. The results of EXAMPLES 6-11 are set forth in Tables 6, 7 and 8 below. The amounts reported are in parts by weight.
TABLE 6______________________________________CHARGEPARTS BY EXAMPLE NO.WEIGHT 6 7 8 9 10 11______________________________________tributyl 142.10 150.30 139.55 150.80 151.30 150.85phosphitehydroxy- 133.00 140.70 130.75 141.30 141.65 141.70ethyl-n-dodecylsulfidethiobis- 66.10 70.05 65.00 70.60 70.60 70.15ethanolsodium .05 .05 .05 .05 .05 .05methoxidetridecyl 31.60 64.15 21.70 26.95 42.45 35.40alcoholwaste butyl 35.20 71.36 23.94 29.78 47.02 38.92alcoholANALYSISwt. % phos- 5.3 5.0 5.2 5.2 5.1 5.1phorouswt. % 10.3 9.7 10.8 11.3 11.2 11.6sulfurtotal acid 52.5 10.7 37 34 11 11.6number(TAN) mgKOH/gm______________________________________
TABLE 7______________________________________ EXAMPLE NO. 6 7 8 9 10 11______________________________________.sup.13 C NMR(mole %)sulfur- 40.4 20.7 30.0 30.7 23.1 23.7containingethersphosphorous- 38.4 41.4 35.1 37.7 41.8 41.8containingestersalcohol 21.6 32.3 30.5 27.9 30.2 29.6other 0 5.6 4.4 3.7 4.9 5.0.sup.31 P NMR (mole %)tributyl 0 0 0 0 0 0phosphiteProductrepresented by:formula 74.2 69.2 39.2 44.2 67.3 67.1XIformula 8.9 19.5 48.0 40.3 2.33 23.0XIIformula 1.1 0.6 0.7 0.6 0 0XIIIformula 9.5 6.9 6.1 6.5 8.0 7.2XIVother 6.3 3.7 6.1 8.4 1.3 2.6______________________________________
TABLE 8______________________________________ EXAMPLE NO. 6 7 8 9 10 11______________________________________processstep-hrs.charge 1.0 5.0 2.5.sup.1 4.0 5.3 4.8heat to 1.0 2.0 1.0 2.0 1.5 1.5110.degree. C.soak at 11.0 6.5 7.0 7.8 8.8 8.0110-115.degree. C.stripping 0 0 0 0 0 0butylalcoholblendback/ 2.3 3.5 4.0 3.0 1.8 2.0cooldownpumpout 0.8 1.0 2.0 3.3 1.5 2.3total 16.0 18.0 16.5 20.0 18.8 18.5cycletimereactor -60 KPapressure______________________________________ .sup.1 charge actually 12.5 hours due to 10 hour raw material delay
EXAMPLE 12C
A phosphorous- and sulfur-containing reaction product mixture was prepared by adding to a round bottom 4-neck flask equipped with a reflux condenser, a stirrer bar and a nitrogen bubbler 246 parts of hydroxyethyl-n-dodecyl sulfide, 122 parts of thiobisethanol, and 194 parts of dibutyl phosphite. The flask was sealed and flushed with nitrogen, and the contents were heated at 95.degree. C. The reaction temperature was maintained at 95.degree. C. until approximately 13.5 mls of butyl alcohol were recovered as overhead (about 0.15 moles). Heating was continued until the TAN of the reaction mixture reached about 98. This continued heating took 13.0 hrs, during which time almost no additional butyl alcohol came off. The reaction mixture was then cooled and stripped of residual butyl alcohol by means of a nitrogen sweep. After the reaction mixture was cooled below about 70.degree. C., 40.0 parts of tridecyl alcohol were added with stirring. The overall cycle time charging, reaction and stripping was about 27.5 hours. The product, after the addition of the tridecyl alcohol, was analyzed using .sup.13 C NMR spectral analysis and it was found to contain 46.3 mole % of sulfur-containing thioether species, 22.4 mole % of phosphite ester species, 22.4 mole % of alcohol species, and 8.8 mole % of other species.
All .sup.13 C measurements were taken on a JEOL GSX-400 NMR Spectrometer operating at 100.40 MHz. The samples were prepared to be between 20 and 30% wt/wt in CDCl.sub.3. A standard single pulse experiment was used with a 90.degree. flip angle, and preacquisition delay 4 sec. Broadband proton decoupling was gated off during preacquisition and evolution and on throughout data acquisition.
Chemical shifts reported are internally referenced to deuterochloroform. The spectral observation window was selected to be 24038.5 Hz with 16K data points per scan. All FFTs were done with a 4 Hz gaussian line broadening multiplication prior to transformation. Integral intensities were digitally measured and the values were reported in mole percents.
The product was also analyzed using .sup.31 P NMR spectral analysis and it was found that the phosphite ester species contained 0 mole % of the species designated as formula XIII above, 0 mole % of the species designated as formula XIV, 58.2 mole % of the species designated as formula XI, 37.1 mole % of the species designated as formula XII, and 4.7 mole % "other". The resulting reaction product, after the addition of the tridecyl alcohol, was found to contain 5.82 wt % phosphorous, 11.6 wt. % sulfur, a TAN of 91.36, and existed as a single phase mixture.
EXAMPLES 13-15
The procedure of EXAMPLE 12C was repeated except that the reaction step was carried out under vacuum conditions (-60 KPa), the reaction temperature was 95.degree. C., and the separate stripping step was eliminated. The results of EXAMPLES 12C and 13-15 are set forth in Tables 9, 10 and 11 below.
TABLE 9______________________________________Charge, Parts EXAMPLE NO.by weight 12C 13 14 15______________________________________dibutyl 194 194 194 194phosphitehydroxethyl-n- 246 246 246 246dodecyl sulfidethiobisethanol 122 122 122 122tridecyl 40.0 0 0 0alcoholwaste butyl 11.0 59.3 59.0 41.5alcoholANALYSISwt % phosphorous 5.82.sup.1 6.0 6.3 6.21wt % sulfur 11.6.sup.1 12.7 12.5 N/D.sup.2TAN, mg KOH/gm 91.4.sup.1 101.4 109.9 107______________________________________ .sup.1 after addition of tridecyl alcohol .sup.2 not determined
TABLE 10______________________________________ EXAMPLE NO. 12C 13 14 15______________________________________.sup.13 C NMR (mole %)sulfur-containing 46.3 33.6 34.1 36.1ethersphosphorous- 22.4 29.3 29.4 27.8containing estersalcohol 22.4 29.3 26.5 29.6other 8.8 7.8 10.0 6.5.sup.31 P NMR (mole %)tributyl phosphite 0 0 0 0Productrepresented by:formula XI 37.1 12.9 65.4 62.0formula XII 58.2 81.0 33.1 37.1formula XIII 0 0 0 0formula XIV 0 0.9 0 0other 4.7 5.1 1.5 0.9______________________________________
TABLE 11______________________________________ EXAMPLE NO. 12C 13 14 15______________________________________Process step, hours 1 1 1 1charge 0.5 0.5 0.5 0.5heat to reactiontemperaturesoak 13.0 5.0 5.0 5.0stripping of butyl 10.0 0 0 0alcoholblendback.sup.1 /cooldown 3.0 3.0 3.0 2.5total cycle time 27.5 9.5 9.5 9.0reactor pressure A B B B______________________________________ .sup.1 no blendback of tridecyl alcohol for EXAMPLES 13, 14 and 15 A atmospheric B -60 KPa
The data in Tables 5, 8 and 11 indicate that the reduced pressure process of the present invention resulted in reduced cycle times.
EXAMPLE 16
Part A
A polyisobutenyl succinic anhydride (PIBSA) having an SA:PIB ratio, i.e. functionality, of 1.04, was prepared by heating a mixture of 100 parts of polyisobutylene (PIB) having a number average molecular weight (Mn) of 940 with 13 parts of maleic anhydride to a temperature of about 220.degree. C. When the temperature reached 120.degree. C., chlorine addition was begun and 1.05 parts of chlorine at a constant rate were added to the hot mixture for about 5 hours. The reaction mixture was then heat soaked at 220.degree. C. for about 1.5 hours and then stripped with nitrogen for about 1 hour. The resulting polyisobutenyl succinic anhydride had an ASTM Saponification Number of 112 which calculates to a succinic anhydride (SA) to polyisobutylene (PIB) ratio of 1.04 based upon the starting PIB as follows: ##EQU1##
The PIBSA product composition was 90 wt. % active ingredient (a.i.), the remainder being primarily unreacted PIB. The SA:PIB ratio of 1.04 is based upon the total PIB charged to the reactor as starting material, i.e., both the PIB which reacts and the PIB which remains unreacted.
Part B
The PIBSA of Part A was aminated as follows: 1500 grams (1.5 moles) of the PIBSA and 1666 grams of S150N lubricating oil (solvent neutral oil having a viscosity of about 150 SSU at 100.degree. C.) were mixed in a reaction flask and heated to about 149.degree. C. Then, 193 grams (1 mole) of a commercial grade of polyethyleneamine which was a mixture of polyethyleneamines averaging about 5 to 7 nitrogen per molecule, hereinafter referred to as PAM, was added and the mixture was heated to 150.degree. C. for about 2 hours; followed by 0.5 hours of nitrogen stripping, then cooling to give the final product (PIBSA-PAM). This product had a viscosity of 140 cs. at 100.degree. C., a nitrogen content of 2.12 wt. % and contained approximately 50 wt. % PIBSA-PAM and 50 wt. % unreacted PIB and mineral oil (S150N).
Part C
The PIBSA-PAM of Part B was borated as follows: 98 parts by weight of the PIBSA-PAM were mixed with 2 parts by weight of boric acid and the mixture was heated to 160.degree. C. while stirring and blowing the reaction mass with nitrogen. The mixture was kept at 160.degree. C. for 2 hours, sparged with nitrogen for 1 hour and filtered. The resulting product was analyzed for 0.35 % boron.
EXAMPLE 17
A hydroxyl amine of the formula: ##STR47## wherein p is 1; X is O; R.sub.9 is a C.sub.18 aliphatic hydrocarbon radical; R.sub.8 is H; R.sub.10 is C.sub.3 alkylene; R.sub.11 and R.sub.12 are C.sub.2 alkylene; and each q is 1 was prepared by first reacting 270 parts by weight of octadecyl alcohol with 53 parts by weight of acrylonitrile in the presence of KOH at a temperature in the range of 100.degree. to 110.degree. F. for about 18 hours to form an ether nitrile intermediate. The intermediate was then hydrogenated in the presence of a Raney Nickel catalyst at a temperature in the range of from 270.degree. to 280.degree. F. until 2 moles of hydrogen had been absorbed. The ether amine was then reacted with 88 parts by weight of ethylene oxide at a temperature in the range of about 280.degree. F. for 12 hours to form the hydroxyl amine product.
EXAMPLE 18
An ATF base fluid, designated hereinafter as the Test Base, was formulated with conventional amounts of seal swell additive, anti-oxidant, viscosity index improver and mineral oil base.
To two samples of the Test Base there were added the borated PIBSA-PAM dispersant of EXAMPLE 16, Part C, together with a phosphorous- and sulfur-containing mixture prepared in accordance with one of EXAMPLES 6 or 13. To each sample there was also added a hydroxyl amine friction modifier in accordance with formula VII of EXAMPLE 17 above, wherein p is 1, R.sub.8 is hydrogen, R.sub.9 and R.sub.10, combined, are a C.sub.18 aliphatic hydrocarbon radical, R.sub.11 and R.sub.12 are C.sub.2 alkylene, and each q is 1.
The compositions of the resulting formulations are summarized in Table 12 as follows, wherein the formulation numbers correspond to the EXAMPLE number which describes the preparation of the particular phosphorous- and sulfur-containing reaction product mixture that was used to prepare the respective formulations:
TABLE 12______________________________________ EXAMPLE NO. 1C 6 13______________________________________Component, wt %ATF Base Fluid.sup.1 94.95 94.95 94.95Borated PIBSA-PAM 4.4 4.74 4.74Hydroxyl amine 0.15 0.21 0.21p = 1, x = 0p- and s-containingproduct of:EXAMPLE 1C 0.5 0 0EXAMPLE 6 0 0.5 0EXAMPLE 13 0 0 0.5______________________________________ .sup.1 88.40 mineral oil base; 0.51 seal swell additive; 0.31 antioxidant and 4.10 viscosity index improver.
4000 CYCLE FRICTION TEST
This test uses an SAE No. 2 type friction machine operated successfully for 4000 cycles wherein no unusual clutch plate wear or composition-face plate flaking occurs. The test is conducted in a continuous series of 20 second cycles, each cycle consisting of three phases as follows: Phase I (10 seconds)--motor on at speed of 3,600 rpm, clutch plates disengaged; Phase II (5 seconds)--motor off, clutch plates engaged; and Phase III (5 seconds)--motor off, clutch plates released. 4000 cycles are repeated using 20740 J. of flywheel energy at 40 psi. of applied cutch pressure. During the clutch engagement, friction torque is recorded as a function of time as the motor speed declines from 3600 rpm to 0. From the torque traces, the dynamic torque (T.sub.D) is determined midway between the start and end of clutch engagement (i.e. at a motor speed of 1800 rpm), as well as the torque (T.sub.0) just before lock-up, e.g., between 0 and 20 rpm. The amount of time in seconds in phase II it takes for the motor speed to go from 3600 to 0 rpm is referred to as the lock-up time. The torque ratio of the oil formulation is then determined from (T.sub.0 /T.sub.D) as is the torque difference (T.sub.O -T.sub.D). In addition to determining midpoint dynamic torque (T.sub.D) and static torque (T.sub.0), the breakaway static torque (T.sub.S) is also determined. This is achieved by rotating the composition plates at 2 to 3 rpm under a load of 40 psi. while locking the steel reaction plates and preventing them from rotating. The torque is then measured until slippage occurs.
The breakaway static torque expresses the ability of the transmission to resist slippage; the lower the breakaway static torque, the higher the slippage.
Target values for T.sub.D are between about 120 and 150, target values for T.sub.O are 155 maximum, target values for T.sub.S are between about 90 and 125, and target values for T.sub.O /T.sub.D are between about 0.9 to 1.0.
The above test was performed an ATF formulations 1C, 6 and 13.
The following is a summary of the test conditions:
Cycle Rate: 3 per minute
Cycle Make-up:
Motor on, clutch released 10 sec
Motor off, clutch applied 5 sec
Motor off, clutch released 5 sec
Temperature: 115+/-5.degree. C.
Pressure: 275+/-3 kPa
Velocity: 3600 rpm
Energy: 20740+/1 100 J
Fluid Quantity: 305 mL +/-5 mL
Paper Speed: 100 mm per sec
Torque
Calibration 2700 Nm
Total Cycles: 4000
The results of the test are shown in Table 13.
TABLE 13______________________________________Formula- TESTtion No. CYCLE T.sub.D (Nm) T.sub.o (Nm) T.sub.S (Nm) TO/T.sub.D______________________________________ 1C 200 129 122 104 0.94 1C 4000 129 122 108 0.98 6 200 129 126 115 0.98 6 4000 145 136 115 0.9813 200 132 122 115 0.9413 4000 136 122 102 0.90Target 120-150 (155 max) 90-125 0.9-1.0Values______________________________________
The data reported in Table 13, which is derived from 4000 cycle friction test, at 200 cycles and 4000 cycles, shows that using ATF Formulations 1C, 6 and 13 resulted in only a slight change in T.sub.O /T.sub.D between the 200th and 4000th cycles; a change which reflects good friction stability. The breakaway static torque values (T.sub.S), the tarque ratio (T.sub.O /T.sub.D), the dynamic torque values (T.sub.D) and the static torque (T.sub.o) all were found to be within the target values.
Formulations 1C, 6 and 13 were then tested in the High-energy, Friction Characteristics and Durability Test (HEFCAD) described in Dexron II.RTM. Specification GM6137-M, Published by GMC Engineering Staff, Engineering Standards Section. This test is run for about 18,000 cycles (i.e. 100 hours).
This test uses a SAE No. 2 Friction Machine operated successfully for 100 hours wherein no unusual clutch plate wear or composition-face plate flaking occurs. After a break-in period of 24 hours, the test is conducted in a continuous series of 20 second cycles, each cycle consisting of three phases as follows: Phase I (10 seconds)--motor on at speed of 3,600 rpm, clutch plates disengaged; Phase II (5 seconds)--motor off, clutch plates engaged; and Phase III (5 seconds)--motor off, clutch plates released. The cycles are repeated for 75 hours after the break-in (i.e. a total of 18,000 cycles) or until failure. The static torque (T.sub.0) in the HEFCAD procedure is measured at an engine speed (rpm) at which the slope of the torque curve approaches infinity, e.g., between 20 and about 0 rpm. The dynamic torque (T.sub.D) is measured midway between the start and end of clutch engagement, i.e at 1800 rpm. Data is reported after 100 hours of test operation. The torque differential (T.sub.0 -T.sub.D) not only expresses the primary friction characteristic but its change over the duration of the test (i.e., between completion of break-in and 100 hours of operation) reflects friction stability.
The results of the HEFCAD test for Formulations 1C, 6 and 13 are summarized at Table 14.
TABLE 14______________________________________ Net Change inFormula- T.sub.O T.sub.D T.sub.S T.sub.O -T.sub.D T.sub.O -T.sub.D over 18000tion (Nm) (Nm) (Nm) (Nm) cycles (100 hours)______________________________________ 1C 141 138 N/D.sup.1 +3 +1 6 142 142 N/D.sup.1 0 +313 126 126 92 0 +2Target 115-175 -- -- -- .ltoreq.14Values______________________________________ .sup.1 not determined
The data in Table 14 demonstrates that acceptably high dynamic torques and friction stability are obtained with the products of the invention.
SPRAG WEAR TEST
This sprag clutch wear test uses a General Motors model THM 440-T4 automatic transmission equipped vehicle, operated at a transmission sump temperature of 225.degree. F. in a cyclic manner accelerating from idling to an engine speed of about 5800 rpm for 1000 cycles. After the test period, the input sprag clutch inner race, sprag assembly, and outer race are visually inspected for wear. The results of this test when using a sample of Formulation 6 as the test fluid are summarized in Table 15 as follows:
TABLE 15______________________________________Input Sprag Clutch, Inner Race No visual wear in element contact areaInput Sprag Clutch, No visual wearClutch assemblyInput Sprag Clutch, No visual wearOuter RaceTransmission Shift Speed 5800 rpmSump Temperature During Test, .degree.F. Min. Max. Avg. 182 240 225______________________________________
EXAMPLE 20
The ATF base fluid according to EXAMPLE 18 was separated into three aliquots. To a first of the aliquots there was added 0.51 weight % of the phosphorous- and sulfur-containing reaction product prepared in accordance with EXAMPLE 6 (Formulation 6), and to a second aliquot there was added 0.51 weight % of the reaction product prepared in accordance with EXAMPLE 13 (Formulation 13). The third aliquot was untreated (control). The three aliquots were then subjected to the Laboratory Multiple Oxidation Test (LMOT). In this test, 50 ml of test fluid with 2.0 gm of iron filings and 0.5 gm of a 1% solution of copper naphthenate is heated to 150.degree. C. and 25 ml of air per minute is passed through the sample. Daily samples are taken and the number of days for visible sludge to appear on blotter paper is recorded. Results are given as "Days to Fail". The results obtained using the above three fluids as test samples are shown in Table 15.
TABLE 16______________________________________ADDITIVE DAYS TO FAILURE______________________________________FORMULATION 6 16+FORMULATION 13 21+CONTROL 5______________________________________
The data in Table 16 shows the strong anti-oxidation performance of the products of the invention.
The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the invention.

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Number	Date	Country
8803554	May 1988	WOX
8803554	May 1988	WOX
8809804	Dec 1988	WOX
8912666	Dec 1989	WOX
8912666	Dec 1989	WOX

	Number	Date	Country
Parent	370315	Jun 1989
Parent	210831	Jun 1988

Low pressure derived mixed phosphorous- and sulfur- containing reaction products useful in power transmitting compositions and process for preparing same

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