Patent Application
20090093384
The present invention relates to a lubricant that decreases micropitting on metal surfaces.
Wind turbines as an alternative renewable energy source are attracting more interest. Wind turbines produce electricity by converting mechanical to electrical energy. A gear box is typically situated between the rotor of the wind turbine and the generator. The high torque puts a large amount of stress on the gears and bearings in the gear box of these wind turbines.
Gear box manufacturers are developing gears for industrial applications that are capable of providing increasing amounts of power. The increase in power is a requirement for premium industrial applications such as noted for wind turbine specifications. The increased power results in lubricants operating at higher loads and higher operating temperatures. Conventional lubricants in these operating environments may not adequately protect against wear, micropitting and/or scuffing.
WO 00/01790 entitled “Mixed Phosphorus Compounds and Lubricants Containing the Same” assigned to The Lubrizol Corporation discloses a lubricating composition containing a major amount of oil of lubricating viscosity and combination of a di or tri hydrocarbyl phosphite, at least one reaction product of a di or tri hydrocarbyl phosphate and sulfur or a source of sulfur; at least one di or tri hydrocarbyl monothiophosphate; or a salt thereof; and at least one salt of a hydrocarbyl phosphoric acid ester. The lubricating compound provides antiwear properties and thermal stability.
Industrial applications are resulting in more fatigue to gear boxes due to prolonged periods of use between maintenance and service intervals. Further, lubricants are needed to enhance the fatigue life of both the gears and bearings in the wind turbines.
Micropitting is a form of fatigue and wear on metal surfaces resulting in the loss of material from repeated stress cycles acting on the metal surfaces. Micropitting damage occurs generally to bearings and gear teeth. Micropitting over time can lead to rapid wear, surface damage, reduced gear tooth accuracy, gear tooth fractures and increased noise.
The composition of the lubricant, as well as the operating environment, affects micropitting on the surfaces. Many lubricants reduce the friction between metal surfaces. It is desirable for an industrial lubricant to decrease the micropitting on the gears and bearings.
The present invention provides for a lubricant to exhibit performance improvements and improve wear protection, in particular, to reduce micropitting on metal surfaces of industrial gears and bearings.
The invention provides for an industrial lubricant composition comprising:
(1) a high TBN overbased detergent,
(2) a sulfur containing component selected from the group consisting of a polysulfide such as an olefin sulfide, substituted thiadiazole or mixtures thereof,
(3) a demulsifier,
(4) an antifoam agent selected from the group consisting of silicone antifoaming agents and non-silicone antifoam agents,
(5) a phosphorus containing acid, salt or ester,
(6) an oil of lubricating viscosity, and
(7) optionally one or more performance additive selected from the group consisting of metal deactivators, detergents, borated dispersants, non-borated dispersants, viscosity index improvers, viscosity modifiers antioxidants, corrosion inhibitors, pour point depressants, seal swelling agents or mixtures thereof.
The invention provides for a method of lubricating a variety of industrial gear and/or bearings comprising contacting the gear and/or bearing with a lubricant comprising
(1) a high TBN overbased detergent,
(2) a sulfur containing component selected from the group consisting of a polysulfide such as an olefin sulfide, substituted thiadiazole or mixtures thereof,
(3) a demulsifier,
(4) an antifoam agent selected from the group consisting of silicone antifoaming agents and non-silicone antifoam agents,
(5) a phosphorus containing acid, salt or ester,
(6) an oil of lubricating viscosity, and
(7) optionally one or more performance additive selected from the group consisting of metal deactivators, detergents, borated dispersants, non-borated dispersants, viscosity index improvers, viscosity modifiers, antioxidants, corrosion inhibitors, pour point depressants, seal swelling agents or mixtures thereof.
The lubricant results in reduced micropitting for industrial gears and bearings. In one embodiment the formulated industrial gear lubricant reduces micropitting in industrial gears such as wind turbine applications.
The present invention provides for an additive package in an oil to make a lubricant wherein the lubricant provides high micropitting resistance for industrial gears and bearings. In another embodiment, the lubricant provides for the decrease of micropitting for industrial gears and bearings.
The lubricant contains an overbased detergent. The use of the overbased detergent with high TBN improves the micropitting resistance in the lubricant.
The overbased detergents include oil soluble neutral and overbased salts of alkali or alkaline earth metals with sulfonic acids, carboxylic acids, organic phosphorus acids and the like.
The term “overbased” is a term of art which is generic to known classes of metal salts or complexes. These materials have also been referred to as “basic”, “superbased”, “hyperbased”, “complexes”, “metal complexes”, “high-metal containing salts”, and the like. Overbased products are metal salts or complexes characterized by a metal content in excess of that which would be present according to the stoichiometry of the metal and the particular acidic organic compound reacted with the metal, e.g., a sulfonic acid.
Overbased detergents include phenates; carboxylates; sulfonates; alkali earth metal and alkaline earth metal detergents; salicylates; salixarates; calixarates; saliginen; overbased calcium detergents; overbased detergents containing metals such as Mg, Be, Sr, Na, Ca and K; mixtures thereof; and the like. Overbased detergents are further described in U.S. Pat. No. 5,484,542 which is incorporated herein by reference. Exemplary overbased detergents include magnesium sulfonate, calcium sulfonate, magnesium phenates, calcium phenates, magnesium salicylates, calcium salicylates, and the like.
Such materials are described in terms of the total base number (“TBN”), which is a measure of the base capacity of the product. Methods for preparing these overbased salts as well as an extremely diverse group of overbased salts are known in the art. In one embodiment, overbased salts are made by contacting a reaction mixture comprising at least one organic material to be overbased, (e.g., sulfonic acid, carboxylic acid, phenol, certain classes of organic phosphorus acids), a reaction medium consisting essentially of at least one inert organic solvent/diluent for said organic material to be overbased (e.g., mineral oil), a stoichiometric excess of at lest one metal base, (e.g., sodium hydroxide, calcium hydroxide, magnesium oxide), at least one promoter, (e.g., methanol, phenol) with at least one acidic material, (e.g., CO2, SO2) at an elevated temperature (e.g., 60°-300° C.). In one embodiment the “overbased” detergents are formed by reacting carbon dioxide with mixtures of lime (calcium hydroxide) and an alkyl benzene sulfonate soap to form calcium carbonate containing micelles. More than an equivalent amount of lime and carbon dioxide are used so that the product detergent becomes basic in character.
The overbased detergents may be used alone or in combination.
The overbased detergents are present in the range of about 0.1% to about 10%, in one embodiment in the range of about 0.3% to about 7% in one embodiment in the range of about 0.5% to about 5% and in another embodiment in the range of about 0.3% to about 1% by weight of the lubricant.
The TBN of the overbased detergents is in one embodiment at least 10, in one embodiment at least 100, in one embodiment at least 200, in one embodiment at least 400 and in one embodiment 600. Where mixtures of overbased detergents are used, at least one overbased detergent should have a TBN value of at least 100. However, the average TBN of these mixtures may also correspond to a TBN value greater than 100.
The lubricant requires a sulfur containing component. The sulfur containing component includes polysulfides, substituted thiadiazoles and the like.
An exemplary polysulfide is olefin sulfide.
As used herein the term “polysulfide” includes compounds that contain three or more sulfur atoms including oligomeric species that may have multiple mono- or di-sulfide linkages within the same molecule.
The polysulfide is generally characterized as having sulfur-sulfur linkages. Typically the linkages have about 2 to about 8 sulfur atoms, or about 2 to about 6 sulfur atoms, or 2 to about 4 sulfur atoms.
In one embodiment the polysulfide contains at least about 20 wt %, or at least about 30 wt % of the polysulfide molecules contain three or more sulfur atoms.
In one embodiment at least about 50 wt % of the polysulfide molecules are a mixture of tri- or tetra-sulfides. In other embodiments at least about 55 wt %, or at least about 60 wt % of the polysulfide molecules are a mixture of tri- or tetra-sulfides.
In one embodiment up to about 90 wt % of the polysulfide molecules are a mixture of tri- or tetra-sulfides. In other embodiments up to about 80 wt % of the polysulfide molecules are a mixture of tri- or tetra-sulfides.
The polysulfide in other embodiments contain about 0 wt % to about 20 wt %, or about 0.1 to about 10 wt % of a penta- or higher polysulfide.
In one embodiment the polysulfide contains less than about 30 wt % or less than about 40 wt % of a disulfide in the polysulfide.
The polysulfide typically provides about 0.5 to about 5 wt %, or about 1 to about 3 wt % of sulfur to the lubricating composition.
The polysulfide includes a sulfurized organic polysulfide including oils, fatty acids or ester, olefins or polyolefins.
Oils which may be sulfurized include natural or synthetic oils such as mineral oils, lard oil, carboxylate esters derived from aliphatic alcohols and fatty acids or aliphatic carboxylic acids (e.g., myristyl oleate and oleyl oleate), and synthetic unsaturated esters or glycerides.
Fatty acids include those that contain about 8 to about 30, or about 12 to about 24 carbon atoms. Examples of fatty acids include oleic, linoleic, linolenic, tall oil and rosin acids. Sulfurized fatty acid esters prepared from mixed unsaturated fatty acid esters such as are obtained from animal fats and vegetable oils, including tall oil, linseed oil, soybean oil, rapeseed oil, and fish oil.
The polysulfide includes olefins derived from a wide range of alkenes. The alkenes typically have one or more double bonds. The olefins in one embodiment contain about 3 to about 30 carbon atoms. In other embodiments, olefins contain about 3 to about 16, or about 3 to about 9 carbon atoms. In one embodiment the sulfurized olefin includes an olefin derived from propylene, isobutylene, pentene, olefin sulfide or mixtures thereof.
In one embodiment the polysulfide comprises a polyolefin derived from polymerising by known techniques an olefin as described above.
In one embodiment the polysulfide includes dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, sulfurized dicyclopentadiene, sulfurized terpene, sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons and the like.
Examples of substituted thiadiazoles include 2-(N,N-dialkyldithiocarbamoyl)benzothiazoles, 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles, 1,3,4 thiadiazoles, 2,5bis(tert-nonyldithio), 2,5-bis(N,N-dialkyldithiocarbamoyl)-1,3,4-thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof. In one embodiment the metal deactivator includes a 2,5-bis(alkyl-dithio)-1,3,4-thiadiazole.
The sulfur containing component may be used alone or in combination.
The sulfur containing component is used in the range of about 0.1% to about 5%, in another embodiment in the range of about 0.5% to about 2% and in another embodiment in the range of about 0.75% to about 1.5% and in another embodiment about 1 to about 1.5% of the lubricant.
Demulsifiers include derivatives of propylene oxide, ethylene oxide, polyoxyalkylene alcohols, alkyl amines, amino alcohols, diamines or polyamines reacted sequentially with ethylene oxide or substituted ethylene oxides or mixtures thereof. Examples of demulsifiers include polyethylene glycols, polyethylene oxides, polypropylene oxides, ethylene oxide-propylene oxide, glycolic monooleate, an overbased calcium sulfonate different from the overbased detergent, or mixtures thereof.
The demulsifiers may be used alone or in combination.
The demulsifiers are used in the range of about 25 ppm to about 1000 ppm in another embodiment in the range of about 50 ppm to about 750 ppm and in another embodiment about 75 ppm to about 500 ppm of the lubricant.
Foam inhibitors include copolymers of ethyl acrylate and 2-ethylhexylacrylate and optionally vinyl acetate demulsifiers including polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers; silicones such as polyacetates, dimethyl silicone, polysiloxanes, polyacrylates or mixtures thereof. Examples of foam inhibitors include, but are not limited to, a copolymer of ethyl acrylate, 2-ethylhexylacrylate and vinyl acetate; 2-ethylhexyl/ethyl acrylate copolymers; polydimethyl/siloxane; or mixtures thereof.
The foam inhibitors may be used alone or in combination.
The foam inhibitors are used in the range of about 25 ppm, to about 1000 ppm, in another embodiment in the range of about 50 ppm to about 750 ppm and in another embodiment about 75 ppm to about 500 ppm of the lubricant.
The oil of lubricating viscosity includes natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined and refined oils or mixtures thereof.
Unrefined oils are those obtained directly from a natural or synthetic source generally without (or with little) further purification treatment.
Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Purification techniques are known in the art and include solvent extraction, secondary distillation, acid or base extraction, filtration, percolation and the like.
Re-refined oils are also known as reclaimed or reprocessed oils, and are obtained by processes similar to those used to obtain refined oils and often are additionally processed by techniques directed to removal of spent additives and oil breakdown products.
Natural oils useful as the oil of lubricating viscosity include animal oils, vegetable oils (e.g., castor oil, lard oil), mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the parraffinic, naphthenic or mixed paraffinicnaphthenic types and oils derived from coal or shale or mixtures thereof.
Synthetic oils of lubricating viscosity include hydrocarbon oils such as polymerized and interpolymerised olefins (e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers); poly(1-hexenes), poly(1-octenes), poly(1-decenes), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls); alkylated biphenyl ethers and alkylated biphenyl sulfides and the derivatives, analogs and homologs thereof or mixtures thereof.
Another synthetic oil of lubricating viscosity include polyol esters other than the hydrocarbyl-capped polyoxyalkylene polyol as disclosed herein, dicarboxylicesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester of decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic conventional oil of lubricating viscosity also include those produced by Fischer-Tropsch reactions and typically may be hydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil of lubricating viscosity may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.
Oils of lubricating viscosity may further be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows: Group I (sulfur content >0.03 wt %, and/or <90 wt % saturates, viscosity index 80-120); Group II (sulfur content ≦0.03 wt % and ≧90 wt % saturates, viscosity index 80-120); Group III (sulfur content ≦0.03 wt % and ≧90 wt % saturates, viscosity index ≧120); Group IV (all polyalphaolefins PAOs such as PAO-2, PAO-4m PAO-5m PAO-6, PAO-7 or PAO-8); and Group V. The oil of lubricating viscosity include API Group I, Group II, Group III, Group IV, Group V oil or mixtures thereof. In one embodiment, the oil of lubricating viscosity is an API Group I, Group II, Group III, Group IV oil or mixtures thereof. Alternatively, the oil of lubricating viscosity is often an API Group II, Group III or Group IV oil or mixtures thereof.
The oil of lubricating viscosity may be used alone or in combinations.
The oil of lubricating viscosity is used in the range of about 70 wt % to about 99 wt %, and in another embodiment, in the range of about 75 wt % to about 98 wt %, in another embodiment in the range of about 88 wt % to about 97 wt % of the lubricant.
The composition includes a phosphorus-containing acid, salt or ester. The phosphorus-containing acid, salt or ester may be an antiwear agent and/or an extreme pressure agent. In one embodiment the phosphorus-containing acid, salt or ester is in the form of a mixture.
The phosphorus-containing acid, salt or ester may be ash-containing (i.e. metal containing) or ashless (i.e. metal free (prior to being mixed with other components)).
The phosphorus-containing acid, salt or ester includes (i) a non-ionic phosphorus compound; (ii) an amine salt of a phosphorus compound; (iii) an ammonium salt of a phosphorus compound; (iv) a monovalent metal salt of a phosphorus compound, such as a metal dialkyldithiophosphate or a metal dialkylphosphate; or (v) mixtures thereof.
In one embodiment the phosphorus-containing acid, salt or ester includes a metal dialkyldithiophosphate. The alkyl groups of the dialkyldithiophosphate include linear or branched containing about 2 to about 20 carbon atoms, provided that the total number of carbons is sufficient to make the metal dialkyldithiophosphate soluble in the hydrocarbyl-capped group of the polyoxyalkylene polyol. The metal of the metal dialkyldithiophosphate typically includes monovalent or divalent metals. Examples of suitable metals include sodium, potassium, copper, calcium, magnesium, barium or zinc. In one embodiment the phosphorus-containing acid, salt or ester is a zinc dialkyldithiophosphate. Examples of a suitable zinc dialkylphosphate often referred to as ZDDP, ZDP or ZDTP) include, zinc di-(amyl)dithiophosphate, zinc di-(1,3-dimethylbutyl) dithiophosphate, zinc di-(heptyl)dithiophosphate, zinc di-(octyl)dithiophosphate di-(2-ethylhexyl)dithiophosphate, zinc di-(nonyl)dithiophosphate, zinc di-(decyl)dithiophosphate, zinc di-(dodecyl)dithiophosphate, zinc di-(dodecylphenyl)dithiophosphate, zinc di-(heptylphenyl)dithiophosphate, or mixtures thereof.
Examples of a zinc dialkyldithiophosphate derived from mixtures of alcohols include those derived from (i) a mixture of amyl alcohol and isobutyl alcohol, (ii) 2-ethylhexyl alcohol and isopropyl alcohol, and (iii) 4-methyl-2-pentanol and isopropyl alcohol.
In one embodiment the phosphorus-containing acid, salt or ester is other than metal dialkyldithiophosphate.
In one embodiment the phosphorus-containing acid, salt or ester includes an ammonium or amine salt of a phosphorus-containing acid or ester.
The amine salt of a phosphorus acid or ester includes phosphoric acid esters and amine salts thereof; dialkyldithiophosphoric acid esters and amine salts thereof; amine salts of phosphites; and amine salts of phosphorus-containing carboxylic esters, ethers, and amides; and mixtures thereof.
The amine salt of a phosphorus acid or ester may be used alone or in combination. In one embodiment the amine salt of a phosphorus compound is derived from an amine salt of a phosphorus compound, or mixtures thereof.
In one embodiment the amine salt of a phosphorus acid or ester includes a partial amine salt-partial metal salt compounds or mixtures thereof. In one embodiment the amine salt of a phosphorus acid or ester further includes at least one sulfur atom in the molecule.
Suitable amines that are suitable for making the amine salt include primary amines, secondary amines, tertiary amines, and mixtures thereof. The amines include those with at least one hydrocarbyl group, or, in certain embodiments, two or three hydrocarbyl groups. The hydrocarbyl groups may contain about 2 to about 30 carbon atoms, or in other embodiments about 8 to about 26, or about 10 to about 20, or about 13 to about 19 carbon atoms.
Primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, octylamine, and dodecyl-amine, as well as such fatty amines as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine and oleyamine. Other useful fatty amines include commercially available fatty amines such as “Armeene” amines (products available from Akzo Chemicals, Chicago, Ill.), such as Armeen C, Armeen O, Armeen O L, Armeen T, Armeen H T, Armeen S and Armeen S D, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.
Examples of suitable secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine, methylethylamine, ethylbutylamine and ethylamylamine. The secondary amines include cyclic amines such as piperidine, piperazine and morpholine.
In one embodiment the amine includes a tertiary-aliphatic primary amine. The aliphatic group of the tertiary-aliphatic primary amine includes an alkyl group containing about 2 to about 30, or about 6 to about 26, or about 8 to about 24 carbon atoms. Tertiary alkyl amines include monoamines such as tert-butylamine, tert-hexylamine, 1-methyl-1-amino-cyclohexane, tert-octylamine, tert-decylamine, tertdodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine, tert-tetracosanylamine, and tert-octacosanylamine.
In one embodiment the amine salt of a phosphorus acid or ester includes an amine with about C11 to about C14 tertiary alkyl primary groups or mixtures thereof. In one embodiment the amine salt of a phosphorus compound includes an amine with about C14 to about C18 tertiary alkyl primary amines or mixtures thereof. In one embodiment the amine salt of a phosphorus compound includes an amine with about C18 to about C22 tertiary alkyl primary amines or mixtures thereof.
Mixtures of amines may also be used in the invention. In one embodiment a useful mixture of amines is “Primene® 81R” or “Primene® JMT.” Primene® 81R and Primene® JMT (both produced and sold by Rohm & Haas) are mixtures of about C11 to about C14 tertiary alkyl primary amines and about C18 to about C22 tertiary alkyl primary amines respectively.
In one embodiment the amine salt of a phosphorus acid or ester is the reaction product of a about C14 to about C18 alkyl phosphoric acid with Primene 81R® (produced and sold by Rohm & Haas) which is a mixture of about C11 to about C14 tertiary alkyl primary amines.
Examples of the amine salt of a phosphorus acid or ester include the reaction product(s) of isopropyl, methyl-amyl (4-methyl-2-pentyl or mixtures thereof), 2-ethylhexyl, heptyl, octyl or nonyl dithiophosphoric acids with ethylene diamine, morpholine, or Primene 81R™, and mixtures thereof.
In one embodiment a dithiophosphoric acid may be reacted with an epoxide or a glycol. This reaction product is further reacted with a phosphorus acid, anhydride, or lower ester (where “lower” signifies about 1 to about 8, or about 1 to about 6, or about 1 to about 4, or 1 to about 2 carbon atoms in the alcohol-derived portion of the ester). The epoxide includes an aliphatic epoxide or a styrene oxide. Examples of useful epoxides include ethylene oxide, propylene oxide, butene oxide, octene oxide, dodecene oxide, styrene oxide and the like. In one embodiment the epoxide is propylene oxide. Suitable examples of the glycols include aliphatic glycols having 1 to about 12, or about 2 to about 6, or about 2 to about 3 carbon atoms. The dithiophosphoric acids, glycols, epoxides, inorganic phosphorus reagents and methods of reacting the same are described in U.S. Pat. Nos. 3,197,405 and 3,544,465. The resulting acids may then be salted with amines. An example of suitable dithiophosphoric acid is prepared by adding phosphorus pentoxide (about 64 grams) at about 58° C. over a period of about 45 minutes to about 514 grams of hydroxypropyl O,O-di(1,3-dimethly butyl)phosphorodithioate (prepared by reacting di(1,3-dimethly butyl)-phosphorodithioic acid with about 1.3 moles of propylene oxide at about 25° C.). The mixture is heated at about 75° C. for about 2.5 hours, mixed with a diatomaceous earth and filtered at about 70° C. The filtrate contains about 11.8% by weight phosphorus, about 15.2% by weight sulfur, and an acid number of 87 (bromophenol blue).
In one embodiment the phosphorus-containing acid, salt or ester includes a non-ionic phosphorus compound. Typically the non-ionic phosphorus compound may have an oxidation of +3 or +5. The different embodiments include phosphite ester, phosphate esters, or mixtures thereof. A more detailed description of the non-ionic phosphorus compound include column 9, line 48 to column 11, line 8 of U.S. Pat. No. 6,103,673.
In one embodiment the phosphorus-containing acid, salt or ester includes an amine salt of at least one partially esterified monothiophosphoric acid, or mixtures thereof.
In one embodiment the phosphorus-containing acid, salt or ester includes an amine salt of at least one partially esterified phosphoric acid.
A more detailed description of the amine salt of at least one partially esterified monothiophosphoric acid; and the amine salt of at least one partially esterified phosphoric acid is disclosed in EP 460 317.
In one embodiment the phosphorus component of the lubricant composition does not contain a thiophosphate, monothiophosphate and/or a trialkyl monothiophosphate. In one embodiment the phosphorus component of the lubricant composition does not contain a substantial amount of a thiophosphate, monothiophosphate and/or a trialkyl monothiophosphate. In one embodiment the phosphorus component of the lubricant composition is substantially free of a thiophosphate, monothiophosphate and/or a trialkyl monothiophosphate.
The phosphorus-containing acid, salt or ester may be used alone or in combination.
The phosphorus-containing acid, salt or ester is present in the lubricating composition in a range of about 0.01 wt % to about 5 wt %, about 0.05 wt % to about 2 wt %, or about 0.1 wt % to about 1 wt % of the lubricant.
The lubricating composition of the invention optionally further includes one or more other performance additive. The other performance additives include metal deactivators, detergents, borated dispersants, non-borated dispersants, viscosity index improvers, viscosity modifiers, antioxidants, corrosion inhibitors, pour point depressants, seal swelling agents, or mixtures thereof.
The other performance additives may be used alone or in combination. The specific class of performance additives, as well as other classes of other performance additives, in the lubricant may be used alone or in combination.
The total combined amount of the other performance additive compounds present in the lubricant is at about 0 wt % to about 20 wt %, or in another embodiment, about 0. wt % to about 20 wt %, or in another embodiment, about 0.1 wt % to about 10 wt % or about 0.5 wt % to about 10 wt %, and about 1 to about 5 wt %, of the lubricant. Although one or more of the other performance additives may be present, it is common for the other performance additives to be present in different amounts relative to each other.
The metal deactivator may also be described as a yellow-metal passivator.
Examples of a metal deactivator include at least one of benzotriazoles, 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, 2-alkyldithiobenzothiazoles, 2-(N,N-dialkyldithiocarbamoyl)benzothiazoles, 1,3,4 thiadiazole, 2,5-(bis(tert-nonyldithio, 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles, 2,5-bis(N,N-dialkyldithiocarbamoyl)-1,3,4-thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof. In one embodiment the metal deactivator includes a benzotriazole. In one embodiment the metal deactivator includes a 2,5-bis(alkyl-dithio)-1,3,4-thiadiazole.
Benzotriazoles include those containing hydrocarbyl substitutions on at least one of the following ring positions 1- or 2- or 4- or 5- or 6- or 7-. The hydrocarbyl groups in different embodiments contain 1 to about 30, or 1 to about 15, or 1 to about 16 carbon atoms. In one embodiment the metal deactivator includes tolyltriazole. In one embodiment hydrocarbyl benzotriazoles substituted at positions 4- or 5- or 6- or 7- are further reacted with an aldehyde and an amine.
Examples of suitable hydrocarbyl benzotriazoles further reacted with an aldehyde and an amine include N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methanamine, 2H-benzotriazole-2-methanamine, N-(4-methoxyphenyl)-1H-benzotriazole-1-methanamine, N,N-didodecyl-1H-benzotriazole-1-methanamine, N-(1H-benzotriazol-1-ylmethyl)-N-(2-ethylhexyl)-1H-benzotriazole-1-methanamine, N-methyl-N-phenyl-1H-benzotriazole-1-methanamine, 4,5,6,7-tetrahydro-N,N-ditridecyl-1H-benzotriazole-1-methanamine, N,N-dioctadecyl-1H-benzotriazole-1-methanamine, 5-methyl-N,N-dioctyl-1H-benzotriazole-1-methanamine, N,N-dibutyl-1H-benzotriazole-1-methanamine, N-(4-methylphenyl)-1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-1H-benzotriazole-1-methanamine N,N-dioctyl-2H-benzotriazole-2-methanamine, N-dodecyl/-1H-benzotriazole-1-methanamine, N-phenyl-1H-benzotriazole-1-methanamine, N,N-didodecyl-4,5,6,7-tetrahydro-1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazole-1-methanamine, N-octadecyl-1H-benzotriazole-1-methanamine, N,N-didodecyl-2H-benzotriazole-2-methanamine, N,N-dioctyl-1H-benzotriazole-1-methanamine, N-(2-ethylhexyl)-1H-benzotriazole-1-methanamine, 4,5,6,7-tetrahydro-N,N-ditetradecyl-1H-benzotriazole-1-methanamine, or mixtures thereof. In one embodiment the metal deactivator includes N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methanamine or N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methanamine.
In one embodiment, the metal deactivator includes at least one of (i) a 2,5-bis(alkyl-dithio)-1,3,4-thiadiazole, (ii) a benzotriazole containing a hydrocarbyl substitution on at least one of the following ring positions 4- or 5- or 6- or 7-, or (iii) a benzotriazole containing a hydrocarbyl substitution (typically a benzotriazole further reacted with an aldehyde and an amine) at least one of the following ring positions 1- or 2-.
In one embodiment, the metal deactivator includes 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles. In different embodiments the alkyl groups of 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles contain 1 to about 30, or about 2 to about 25, or 4 to about 20, or about 6 to about 16 carbon atoms. Examples of suitable 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles include 2,5-bis(tert-octyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-decyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-undecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, or mixtures thereof.
The metal deactivator may be used alone or in combination.
The viscosity modifier provides both viscosity index improving properties and dispersant properties. Viscosity modifiers include copolymers of styrene-butadiene rubber polymers, ethylene-propylene, polyisobutenes, hydrogenated radical isoprene polymers, polymethacrylate acid esters, polyalkyl styrenes, alkenyl aryl conjugated diene copolymers, polyalkylmethacrylates, hydrogenated styrene-butadiene rubbers, ethylene-propylene copolymers, hydrogenated styrene-isoprene polymers, hydrogenated diene polymers, polyalkyl styrenes, polyolefins (such as polyisobutylene), esters of maleic anhydride-styrene copolymers, or mixtures thereof. In one embodiment the viscosity modifier is a polyolefin, typically polyisobutylene.
The viscosity modifiers further include polyacrylates obtained from the polymerization or copolymerization of one or more alkyl acrylates, polymethyacrylate acid esters, polyacrylate acid esters, and esters of maleic anhydride-styrene copolymers, hydrogenated copolymers of styrene-butadiene, ethylene-propylene copolymers, polyisobutenes, hydrogenated styrene-isoprene polymers, hydrogenated isoprene polymers, polymethacrylate acid esters, polyacrylate acid esters, polyalkyl styrenes, hydrogenated alkenyl aryl conjugated diene copolymers, polyolefins, polyalkylmethacrylates and esters of maleic anhydride-styrene copolymers. The viscosity modifiers include nitrogen containing monomers such as vinyl pyridine, N-vinyl pyrrolidone and N,N-dimethylaminoethyl methacrylate and the like.
Functionalized polymers can also be used as viscosity modifiers. Among the classes of such polymers are olefin copolymers and acrylate or methacrylate copolymers. Functionalized olefin copolymers can be, for instance, interpolymers of ethylene and propylene which are grafted with an active monomer such as maleic anhydride and then derivatized with an alcohol or an amine. Other such copolymers are copolymers of ethylene and propylene which are reacted or grafted with nitrogen compounds. Derivatives of polyacrylate esters are known as dispersant viscosity index modifiers additives. Dispersant acrylate or polymethacrylate viscosity modifiers such as Acryloid™985 or Viscoplex™6-054, from RohMax, are useful. Solid, oil-soluble polymers such as the PIB (polyisobutylene), methacrylate, polyalkystyrene, ethylene/propylene and ethylene/propylene/1,4-hexadiene polymers and maleic anhydride-styrene interpolymer and derivatives thereof, can also be used as viscosity index improvers. The viscosity modifiers polymer architecture includes linear or star structures.
Conventional pol(meth)acrylate polymers may be derived from monomers substantially the same as those defined from the polymeric arms. However, the conventional poly(meth)acrylate is generally free of a functional group selected from a halogen, an —O—N═ group and an —S—C(═S)-group.
Antioxidants include molybdenum compounds such as molybdenum dithiocarbamates, zinc dithiocarbamates, sulfurized olefins, hindered phenols, aminic compounds (such as alkylated diphenylamines (typically di-nonyl diphenylamine, octyl diphenylamine, di-octyl diphenylamine), phenyl alpha napthylamine, tetra methyl hydroquinone and the like.
Detergents include neutral or overbased detergents, Newtonian or non-Newtonian, basic salts of alkali, alkaline earth or transition metals with one or more of a phenate, a sulfurized phenate, a sulphonate, a carboxylic acid, a phosphorus acid, a mono- and/or a di- thiophosphoric acid, a saligenin, an alkylsalicylate, a salixarate and the like.
The ashless dispersants include hydrocarbyl substituted acylated nitrogen compound; hydrocarbyl substituted amine; the reaction product of a hydrocarbyl substituted phenol, amine and formaldehyde; and mixtures thereof.
The ashless dispersant of the present invention can be a hydrocarbyl substituted acylated nitrogen compound. In one embodiment, at least one nitrogen of the acylated nitrogen compound is a quaternary ammonium nitrogen. In one embodiment, the hydrocarbyl substituted acylated nitrogen compound is the reaction product of polyisobutylene succinic anhydride and polyamine, wherein the polyamine has at least one reactive hydrogen. These type nitrogen containing dispersants are often referred to as a succinimide dispersant. Succinimide dispersants are the reaction product of a hydrocarbyl substituted succinic acylating agent and an amine containing at least one hydrogen attached to a nitrogen atom. The term “succinic acylating agent” refers to a hydrocarbon-substituted succinic acid or succinic acid-producing compound (which term also encompasses the acid itself). Such materials typically include hydrocarbyl-substituted succinic acids, anhydrides, esters (including half esters) and halides.
Succinic based dispersants have a wide variety of chemical structures including typically structures such as
In the above structure, each R1 is independently a hydrocarbyl group, which may be bound to multiple succinimide groups, typically a polyolefin-derived group having an
The polyalkenes from which the substituent groups are derived are typically homopolymers and interpolymers of polymerizable olefin monomers of 2 to 16 carbon atoms; usually 2 to 6 carbon atoms.
The olefin monomers from which the polyalkenes are derived are polymerizable olefin monomers characterized by the presence of one or more ethylenically unsaturated groups (i.e., >C═C<); that is, they are mono-olefinic monomers such as ethylene, propylene, 1-butene, isobutene, and 1-octene or polyolefinic monomers (usually diolefinic monomers) such as 1,3-butadiene, and isoprene. These olefin monomers are usually polymerizable terminal olefins; that is, olefins characterized by the presence in their structure of the group >C═CH2. Relatively small amounts of non-hydrocarbon substitutents can be included in the polyolefin, provided that such substituents do not substantially interfere with formation of the substituted succinic acid acylating agents.
Each R1 group may contain one or more reactive groups, e.g., succinic groups, thus being represented (prior to reaction with the amine) by structures such as
in which y represents the number of such succinic groups attached to the R1 group. In one type of dispersant, y=1. In another type of dispersant, y is greater than 1, in one embodiment greater than 1.3 or greater than 1.4; and in another embodiment y is equal to or greater than 1.5. in one embodiment y is 1.4 to 3.5, such as 1.5 to 3.5 or 1.5 to 2.5. Fractional values of y, of course, can arise because different specific R1 chains may be reacted with different numbers of succinic groups.
The amines which are reacted with the succinic acylating agents to form the carboxylic dispersant composition can be monoamines or polyamines. In either case they will be characterized by the formula R4R5NH wherein R4 and R5 are each independently hydrogen, hydrocarbon,amino-substituted hydrocarbon, hydroxy-substituted hydrocarbon, alkoxy-substituted hydrocarbon, amino, carbamyl, thiocarbamyl, guanyl, or acylimidoyl groups provided that no more than one of R4 and R5 is hydrogen. In all cases, therefore, they will be characterized by the presence within their structure of at least one H—N<group. Therefore, they have at least one primary (i.e., H2N—) or secondary amino (i.e., H—N<) group (i.e. reactive hydrogen). Examples of monoamines include ethylamine, diethylamine, n-butylamine, di-n-butylamine, allylamine, isobutylamine, cocoamine, stearylamine, laurylamine, methyllaurylamine, oleylamine, N-methyl-octylamine, dodecylamine, and octadecylamine.
The polyamines from which the dispersant is derived include principally alkylene amines conforming, for the most part, to the formula
wherein t is an integer typically less than 10, A is hydrogen or a hydrocarbyl group typically having up to 30 carbon atoms, and the alkylene group is typically an alkylene group having less than 8 carbon atoms. The alkylene amines include principally, ethylene amines, hexylene amines, heptylene amines, octylene amines, other polymethylene amines. They are exemplified specifically by: ethylene diamine, diethylene triamine, triethylene tetramine, propylene diamine, decamethylene diamine, octamethylene diamine, di(heptamethylene) triamine, tripropylene tetramine, tetraethylene pentamine, trimethylene diamine, pentaethylene hexamine, di(-trimethylene)triamine. Higher homologues such as are obtained by condensing two or more of the above-illustrated alkylene amines likewise are useful. Tetraethylene pentamine is particularly useful.
The ethylene amines, also referred to as polyethylene polyamines, 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).
Hydroxyalkyl-substituted alkylene amines, i.e., alkylene amines having one or more hydroxyalkyl substituents on the nitrogen atoms, likewise are useful. Examples of such amines include N-(2-hydroxyethyl)ethylene diamine, N,N′-bis(2-hydroxyethyl)-ethylene diamine, 1-(2-hydroxyethyl)piperazine, monohydroxypropyl)-piperazine, di-hydroxypropy-substituted tetraethylene pentamine, N-(3-hydroxypropyl)-tetra-methylene diamine, and 2-heptadecyl-1-(2-hydroxyethyl)-imidazoline.
Higher homologues, 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. Condensed polyamines are formed by a condensation reaction between at least one hydroxy compound with at least ore polyamine reactant containing at least one primary or secondary amino group and are described in U.S. Pat. No. 5,230,714 (Steckel).
The succinimide dispersant is referred to as such since it normally contains nitrogen in the form of imide functionality, although it may be in the form of amine salts, amides, imidazolines as well as mixtures thereof. To prepare the succinimide dispersant, one or more of the succinic acid-producing compounds and one or more of the amines are heated, typically with removal of water, optionally in the presence of a normally liquid, substantially inert organic liquid solvent/diluent at an elevated temperature, generally in the range of 80° C. up to the decomposition point of the mixture or the product; typically 100 0 C. to 300° C.
The succinic acylating agent and the amine (or organic hydroxy compound, or mixture thereof) are typically reacted in amounts sufficient to provide at least one-half equivalent, per equivalent of acid-producing compound, of the amine (or hydroxy compound, as the case may be). Generally, the maximum amount of amine present will be about 2 moles of amine per equivalent of succinic acylating agent. For the purposes of this invention, an equivalent of the amine is that amount of the amine corresponding to the total weight of amine divided by the total number of nitrogen atoms present. The number of equivalents of succinic acid-producing compound will vary with the number of succinic groups present therein, and generally, there are two equivalents of acylating reagent for each succinic group in the acylating reagents. Additional details and examples of the procedures for preparing the succinimide dispersants of the present invention are included in, for example, U.S. Pat. Nos. 3,172,892; 3,219,666; 3,272,746; 4,234,435; 6,440,905 and 6,165,235.
In one embodiment, at least one of the amino groups of the succinimide dispersant is further alkylated to a quaternary ammonium salt.
The ashless dispersant can be a hydrocarbyl substituted amine, which can be polyisobutylene amine. The amine used to make the polyisobutylene amine can be a polyamine such as ethylenediamine, 2-(2-aminoethylamino)-ethanol, or diethylenetriamine. The polyisobutylene amine of the present invention can be prepared by several known methods generally involving amination of a derivative of a polyolefin to include a chlorinated polyolefin, a hydroformylated polyolefin, and an epoxidized polyolefin. In one embodiment of the invention the polyisobutylene amine is prepared by chlorinating a polyolefin such as a polyisobutylene and then reacting the chlorinated polyolefin with an amine such as a polyamine at elevated temperatures of generally 100 to 150° C. as described in U. S. Pat. No. 5,407,453. To improve processing a solvent can be employed, an excess of the amine can be used to minimize cross-linking, and an inorganic base such as sodium carbonate can be used to aid in removal of hydrogen chloride generated by the reaction.
In one embodiment, at least one of the amino groups of the polyisobutylene amine dispersant is further alkylated to a quaternary ammonium salt.
The ashless dispersant can be the reaction product of a hydrocarbyl substituted phenol, amine and formaldehyde, which is often referred to as a Mannich dispersant. Mannich dispersant is a reaction product of a hydrocarbyl-substituted phenol, an aldehyde, and an amine or ammonia. The hydrocarbyl substituent of the hydrocarbyl-substituted phenol can have 10 to 400 carbon atoms, in another instance 30 to 180 carbon atoms, and in a further instance 10 or 40 to 110 carbon atoms. This hydrocarbyl substituent can be derived from an olefin or a polyolefin. Useful olefins include alpha-olefins, such as 1-decene, which are commercially available.
The polyolefins which can form the hydrocarbyl substituent can be prepared by polymerizing olefin monomers by well known polymerization methods and are also commercially available. The olefin monomers include monoolefins, including monoolefins having 2 to 10 carbon atoms such as ethylene, propylene, 1-butene, isobutylene, and 1-decene. An especially useful monoolefin source is a C4 refinery stream having a 35 to 75 weight percent butene content and a 30 to 60 weight percent isobutene content. Useful olefin monomers also include diolefins such as isoprene and 1,3-butadiene. Olefin monomers can also include mixtures of two or more monoolefins, of two or more diolefins, or of one or more monoolefins and one or more diolefins. Useful polyolefins include polyisobutylenes having a number average molecular weight of 140 to 5000, in another instance of 400 to 2500, and in a further instance of 140 or 500 to 1500. The polyisobutylene can have a vinylidene double bond content of 5 to 69 percent, in a second instance of 50 to 69 percent, and in a third instance of 50 to 95 percent. The polyolefin can be a homopolymer prepared from a single olefin monomer or a copolymer prepared from a mixture of two or more olefin monomers. Also possible as the hydrocarbyl substituent source are mixtures of two or more homopolymers, two or more copolymers, or one or more homopolymers and one or more copolymers.
The hydrocarbyl-substituted phenol can be prepared by alkylating phenol with an olefin or polyolefin described above, such as a polyisobutylene or polypropylene, using well-known alkylation methods.
The aldehyde used to form the Mannich dispersant can have 1 to 10 carbon atoms, and is generally formaldehyde or a reactive equivalent thereof such as formalin or paraformaldehyde.
The amine used to form the Mannich dispersant can be a monoamine or a polyamine, including alkanolamines having one or more hydroxyl groups, as described in greater detail above. Useful amines include those described above, such as ethanolamine, diethanolamine, methylamine, dimethylamine, ethylenediamine, dimethylaminopropylamine, diethylenetriamine and 2-(2-aminoethylamino)ethanol. The Mannich dispersant can be prepared by reacting a hydrocarbyl-substituted phenol, an aldehyde, and an amine as described in U.S. Pat. No. 5,697,988. In one embodiment of this invention the Mannich reaction product is prepared from an alkylphenol derived from a polyisobutylene, formaldehyde, and an amine that is a primary monoamine, a secondary monoamine, or an alkylenediamine, in particular, ethylenediamine or dimethylamine.
The Mannich reaction product of the present invention can be prepared by reacting the alkyl-substituted hydroxyaromatic compound, aldehyde and polyamine by well known methods including the method described in U.S. Pat. No. 5,876,468.
The Mannich reaction product can be prepared by well known methods generally involving reacting the hydrocarbyl substituted hydroxy aromatic compound, an aldehyde and an amine at temperatures between 50 to 200° C. in the presence of a solvent or diluent while removing reaction water as described in U.S. Pat. No. 5,876,468.
In one embodiment, at least one of the amino groups of the Mannich dispersant is further alkylated to a quaternary ammonium salt.
Another type of ashless dispersant which can be used is a glyoxylate. A glyoxylate dispersant is a fuel soluble ashless dispersant which, in a first embodiment, is the reaction product of an amine having at least one basic nitrogen, i.e. one >N—H, and a hydrocarbyl substituted acylating agent resulting from the reaction, of a long chain hydrocarbon containing an olefinic bond with at least one carboxylic reactant selected from the group consisting of compounds of the formula (I)
(R1C(O)(R2)nC(O))R3 (1)
and compounds of the formula (II)
wherein each of R1, R3 and R4is independently H or a hydrocarbyl group, R2 is a divalent hydrocarbylene group having 1 to 3 carbons and n is 0 or 1:
Examples of carboxylic reactants are glyoxylic acid, glyoxylic acid methyl ester methyl hemiacetal, and other omega-oxoalkanoic acids, keto alkanoic acids such as pyruvic acid, levulinic acid, ketovaleric acids, ketobutyric acids and numerous others. The skilled worker having the disclosure before him will readily recognize the appropriate compound of formula (I) to employ as a reactant to generate a given intermediate.
The hydrocarbyl substituted acylating agent can be the reaction of a long chain hydrocarbon containing an olefin and the above described carboxylic reactant of formula (I) and (II), further carried out in the presence of at least one aldehyde or ketone. Typically, the aldehyde or ketone contains from 1 to about 12 carbon atoms. Suitable aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, pentanal, hexanal. heptaldehyde, octanal, benzaldehyde, and higher aldehydes. Other aldehydes, such as dialdehydes, especially glyoxal, are useful, although monoaldehydes are generally preferred. Suitable ketones include acetone, butanone, methyl ethyl ketone, and other ketones. Typically, one of the hydrocarbyl groups of the ketone is methyl. Mixtures of two or more aldehydes and/or ketones are also useful.
Compounds and the processes for making these compounds are disclosed in U.S. Pat. Nos. 5,696,060; 5,696,067; 5,739,356; 5,777,142; 5,856,524; 5,786,490; 6,020,500; 6,114,547; 5,840,920 and are incorporated herein by reference.
In another embodiment, the ashless dispersant can be an aromatic glyoxylate. The glyoxylate dispersant is the reaction product of an amine having at least one basic nitrogen, i.e. one >N-H, and a hydrocarbyl substituted acylating agent resulting from the condensation product of a hydroxyaromatic compound and at least one carboxylic reactant selected from the group consisting of the above described compounds of the formula (i) and compounds of the formula (II). Examples of carboxylic reactants are glyoxylic acid, glyoxylic acid methyl ester methyl hemiacetal, and other such materials as listed above.
The hydroxyaromatic compounds typically contain directly at least one hydrocarbyl group R bonded to at least one aromatic group. The hydrocarbyl group R may contain up to about 750 carbon atoms or 4 to 750 carbon atoms, or 4 to 400 carbon atoms or 4 to 100 carbon atoms. In one embodiment, at least one R is derived from polybutene. In another embodiment R is derived from polypropylene.
In another embodiment, the reaction of the hydroxyaromatic compound and the above described carboxylic acid reactant of formula (I) or (II) can be carried out in the presence of at least one aldehyde or ketone. The aldehyde or ketone reactant employed in this embodiment is a carbonyl compound other than a carboxy-substituted carbonyl compound. Suitable aldehydes include monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, pentanal, hexanal, heptaldehyde, octanal, benzaldehyde, and higher aldehydes. Other aldehydes, such as dialdehydes, especially glyoxal, are useful. Suitable ketones include acetone, butanone, methyl ethyl ketone, and other ketones. Typically, one of the hydrocarbyl groups of the ketone is methyl. Mixtures of two or more aldehydes and/or ketones are also useful.
In one embodiment, at least one of the amino groups of the aromatic or non-aromatic glyoxylate dispersant is further alkylated to a quaternary ammonium salt.
Compounds and the processes for making these compounds are disclosed in U.S. Pat. Nos. 3,954,808; 5,336,278; 5,620,949 and 5,458,793 and are incorporated herein by reference.
In another embodiment, the boron compound is a borated dispersant. Borated dispersants are prepared by reaction of one or more of the above mentioned ashless dispersants with one or more boron compounds. Typically, the borated dispersant contains from about 0.1% up to about 5% or from about 0.5% up to about 4%, or from 0.7% up to about 3% by weight boron. In one embodiment, the borated dispersant is a borated acylated amine, such as a borated succinimide dispersant. Borated dispersants are described in U.S. Pat. Nos. 3,000,916; 3,087,936; 3,254,025; 3,282,955; 3,313,727; 3,491,025; 3,533,945; 3,666,662 and 4,925,983.
Another class of ashless dispersants is high molecular weight esters. These esters may derive from any of the above mentioned acylating agents including the succinic acylating agent and the glyoxylate type acylating agents. The alcohols from which the esters may be derived may be monohydric alcohols such as methanol, ethanol, isooctanol, dodecanol cyclopentanol, isobutyl alcohol, benzyl alcohol, monomethyl ether of ethylene glycol, monobutyl ether of ethylene glycol. The polyhydric alcohols preferably contain from 2 to about 10 hydroxy radicals. They are illustrated by, for example, ethylene glycol, diethylene glycol, triethylene glycol. An especially preferred class of alcohols is the polyhydric alcohols having at least three hydroxy such as pentaerythritol and trishydroxymethylpropane. Such materials are described in more detail in U.S. Pat. No. 3,381,022
Corrosion inhibitors include fatty amines, esters such as borated glycerol esters (such as glycerol monooleate), fatty glycerol partial esters (for example glycerol mono-oleate, or glycerol di-oleate), (fatty phosphites), fatty acid amides, fatty epoxides, borated fatty epoxides, alkoxylated fatty amines, borated alkoxylated fatty amines, metal salts of fatty acids, fatty imidazolines, condensation products of carboxylic acids and polyalkylene-polyamines, salts of alkylphosphoric acids, tartarates, octylamine octanoate, condensation products of dodecenyl succinic acid or anhydride and a fatty acid such as oleic acid with a polyisobutylenely succinic acid or anhydride polyamine, hydrocarbyl substituted succinic acids or anhydrides such as dodecyl succinic acid or anhydride, polyisobutenyl succinic acids or anhydrides, amide or ester derivatives of hydrocarbyl substituted succinic acids or anhydrides, such as the reaction product of dodecyl succinic anhydride with diols, polyols, and/or epoxides and the like.
Pour point depressants include esters of maleic anhydride-styrene copolymers, polymethacrylates; polyacrylates; polyacrylamides; condensation products of haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers; and terpolymers of dialkylfumarates, vinyl esters of fatty acids, ethylene-vinyl acetate copolymers, alkyl phenol formaldehyde condensation resins, alkyl vinyl ethers, alkyl napthalenes, and mixtures thereof.
The composition may be prepared by any conventional methods including blending, in-line blending, mixing and/or dissolving the components with the oil of lubricating viscosity until the components are substantially or wholly dissolved. The components are mixed sequentially, separately or in combinations thereof. The resulting mixture is added with mixing/blending to the oil or mixture thereof. The method to prepare occurs at a temperature in the range of about 25° C. to about 90° C., in one embodiment in the range of about 40° C. to about 90° C., and in another embodiment in the range of about 55° C. to about 80° C., for a period of time in the range of 1 hour to about 10 hours.
In one embodiment the composition is in the form of a concentrate. The concentrate is prepared by mixing substantially all of the components except a major amount of oil of lubricating viscosity to form a mixture by adding the components sequentially, separately or in combination. The resultant mixture is added with a sufficient portion of oil of lubricating viscosity to form a concentrate.
In one embodiment the lubricant is formed by adding the concentrate to the major amount of oil of lubricating viscosity resulting in the finished lubricant for industrial application. In one embodiment the lubricant is made by mixing the additive components with the desired amount of oil of lubricating viscosity to result in a lubricant for industrial applications.
The invention is useful for lubricating a gear(s) or bearing(s). In one embodiment the lubricant is a gear oil or bearing oil.
In one embodiment the invention is capable of providing a lubricants and a method of lubricating a gear and/or a bearing; and capable of providing at least one of acceptable protection against wear, scuffing and micropitting, whilst providing acceptable hose and/or seal compatability, oxidation stability and cleanliness.
The following examples provide an illustration of the invention. These examples are non exhaustive and are not intended to limit the scope of the invention.
A micropitting test in accordance with FVA-Information sheet No. 54/I-IV which is a public document available from Forschungsvereinigung Antriebstedinik E. V., Lyones Strabe 18, 60528 Frankfurt/Main and was carried out using the inventive composition. This oil with the inventive composition A and C as well as with the comparative composition B and D were a lubricant injected at the gear as a spray at about 90° C. The components of the compositions A, B, C and D as identified in Table 1 were blended together with the base fluid to form the lubricant. The comparative examples did not contain TBN overbased detergent and/or a substituted thiadiazole.
The micropitting test consists of two parts: a load stage test and an endurance test. The load stage test involves a stepwise increase of the load. The pinion is removed and measured for profile form deviation caused by micropitting. Reaching the failure limit after a certain load stage indicates the failure load stage. The load stage test is performed on each flank of the pinion to ensure repeatability in obtaining the failure load stage. The oil is changed between the tests. After completion of the 2nd load stage test, an endurance test is performed without replacing the oil.
Results
The results of the FVA 54/I-IV tests as identified in Table 1 demonstrate the following: A result of 5, 6 or 7 load stages failure leads to a GFT classification of low which means the gear oil cannot perform under highly loaded condition. The invention and the comparative examples did not fail at this load stage.
Failure at load stages 8 or 9 leads to a GFT classification of medium which means the gear oil performs under moderately loaded condition but not highly loaded condition. The comparative examples meet the GFT medium load conditions and comparative example B and D did not fail this load stage. Both of the inventive compositions examples A and C did not fail this load stage.
Failure at load stage 10 leads to a GFT classification of high which means the gear oil performs under highly loaded conditions. Comparative example B and D did not fail at this load stage. However, Comparative example B had a much higher weight loss of the gears than example A, which means there was higher wear to the gear. Comparative example D failed at load stage 9. Both of the inventive examples A and C did not fail at this load stage and demonstrated lower wear by not losing as much weight as related to the comparative examples B and D. Both inventive examples A and C demonstrated lower percentage micropitting then the comparative examples B and D, and had lower profile form deviation values which are the critical estimate of micropitting damage to the gear flanks.
These results demonstrate the benefit of the high TBN detergent in the gear oil by decreasing the profile deactivation and present micropitting and wear on the gear.
From the above descriptions and examples of the invention those skilled in the are will perceive improvements, changes and modifications in the invention. Such improvements, changes and modifications within the skill of the are intended to be covered by the appended claims.
