Patent Application
20180251692
The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.
Corrosion inhibitors are standard additives in fuels and lubricants, which are often based on structures containing acid groups, for example dimer fatty acids.
A disadvantage of these corrosion inhibitors is that they have a tendency to precipitate, especially in the presence of calcium ions, as a result of which their corrosion-inhibiting action is reduced. The deposits formed as a result of this precipitation can additionally impair the working of engines, engine constituents or parts of the fuel system, especially the injection system, specifically the injection pumps or nozzles.
The “injection system” is understood to mean the part of the fuel system in motor vehicles from the fuel pump up to and including the injector outlet. The “fuel system” is understood to mean the components of motor vehicles that are in contact with the particular fuel, preferably the region from the tank up to and including the injector outlet.
In one embodiment of the present invention, the compounds of the invention are to act against deposits not just in the injection system but also in the rest of the fuel system, and here especially against deposits in fuel filters and pumps.
The problem addressed is that of providing corrosion inhibitors which exhibit increased compatibility with calcium ions and at the same time retain their action as a corrosion inhibitor.
The problem is solved by the use according to the claims.
WO 2006/135881 describes quaternized ammonium salts prepared by condensation of a hydrocarbyl-substituted acylating agent and of an oxygen or nitrogen atom-containing compound with a tertiary amino group, and subsequent quaternization by means of hydrocarbyl epoxide in the presence of stoichiometric amounts of an acid such as, more particularly, acetic acid. Further quaternizing agents claimed in WO 2006/135881 are dialkyl sulfates, benzyl halides and hydrocarbyl-substituted carbonates, and dimethyl sulfate, benzyl chloride and dimethyl carbonate have been studied experimentally.
In none of these documents is the anticorrosive action of these compounds recognized.
WO 2014/195464 discloses the use of quaternized ammonium salts for prevention and elimination of deposits in the operation of diesel engines. Also disclosed are examples which show an anticorrosive effect of ammonium salts in metal-free diesel fuels on steel samples. In addition, WO 2014/195464 discloses the use of quaternized ammonium salts for reducing the level of deposits in the intake system of a gasoline engine, such as, more particularly, DISI and PFI (port fuel injector) engines. According to the examples, deposits in injectors of direct injection gasoline engines are prevented and deposits formed beforehand are removed. However, WO 2014/195464 does not comprise any disclosure relating to the cleanliness of valves in intake manifold gasoline engines.
Accordingly, the invention provides for the use of a reaction product comprising a quaternized nitrogen compound or of a component fraction thereof which comprises a quaternized nitrogen compound and has been obtained from the reaction product by purification, wherein the reaction product is obtainable by
The reaction products described show a particular advantage in fuels having a content of alkali metals and/or alkaline earth metals and/or zinc of at least 0.1 ppm by weight, more preferably at least 0.2 ppm by weight and even more preferably at least 0.3 ppm by weight and especially at least 0.5 ppm by weight. Also conceivable is a content of alkali metals and/or alkaline earth metals and/or zinc of at least 1 ppm by weight, preferably at least 2 and more preferably at least 3 ppm by weight.
The present invention further provides for the use of a reaction product comprising a quaternized nitrogen compound or of a component fraction thereof which comprises a quaternized nitrogen compound and has been obtained from the reaction product by purification, wherein the reaction product is obtainable by
The present invention further provides for the use of a reaction product comprising a quaternized nitrogen compound or of a component fraction thereof which comprises a quaternized nitrogen compound and has been obtained from the reaction product by purification, wherein the reaction product is obtainable by
It is an advantage of the reaction products described that they also exhibit their corrosion-inhibiting action in the presence of alkali metals and/or alkaline earth metals and/or zinc, preferably also in the presence of alkaline earth metals. The content of alkali metals and/or alkaline earth metals in fuels results, for example, from mixing with lubricants containing alkali metals and/or alkaline earth metals, for example in the fuel pump. In addition, alkali metals and/or alkaline earth metals may originate from non-desalinated or inadequately desalinated fuel additives, for example carrier oils. The entrainment of alkali metals and/or alkaline earth metals into the fuels can cause the abovementioned disadvantages. One example of a zinc source is antiwear additives.
Alkali metals include particularly sodium and potassium, especially sodium.
Alkaline earth metals include particularly magnesium and calcium, especially calcium.
Zinc should also be emphasized.
Particularly advantageously, the reaction products described are still active even in the presence of calcium and do not exhibit any precipitation.
The stated amounts of alkali metals and/or alkaline earth metals and/or zinc each relate to individual metal species.
It is a further advantage of the compounds of the invention that they increase the conductivity of fuels.
A fuel is generally a very poor electrical conductor. Therefore, electrical charges have a tendency to accumulate locally in such an organic material and to discharge as sparks in an uncontrolled manner, which can lead to explosion or fire on contact of this fuel, which is combustible and highly flammable by nature, with air or oxygen. By means of suitable antistatic additives, it is possible to increase the electrical conductivity of fuels, such that it is no longer possible for static charges to form and the risk of explosion and fire is reduced.
Therefore, it is a further object of the present invention to use the quaternary compounds described as a novel and improved additive formulation suitable for antistatic modification and improvement of the electrical conductivity of fuels and for prevention of electrostatic charging in chemical and physical processes, as is the use of the quaternary compounds described for improving the electrical conductivity and for reducing electrostatic charging of fuels.
The present invention further provides for the use of a reaction product comprising a quaternized nitrogen compound or of a component fraction thereof which comprises a quaternized nitrogen compound and has been obtained from the reaction product by purification, wherein the reaction product is obtainable by
Preference is given to eliminating deposits in the intake valves of port fuel injector engines, called IVD (intake valve deposits).
It has now been found that, surprisingly, the above problem is solved by providing quaternized nitrogen compounds, for example hydrocarbylamine compounds, and fuel and lubricant compositions additized therewith.
Surprisingly, the additives of the invention as illustrated more particularly by the use examples appended are surprisingly effective as corrosion inhibitors in fuels, preferably in gasoline or diesel fuels, more preferably in gasoline fuels.
The present invention relates especially to the following specific embodiments:
RaRbRcN (3)
RaRbRcN (3)
“Component fraction” is preferably understood to mean that the reaction product is freed or depleted of unconverted reactants, particularly hydrocarbyl epoxide, and any by-products, leaving the quaternized nitrogen compound and hydrocarbyl-substituted polycarboxylic acid at least partly together in the component fraction.
In one embodiment of the present invention, preference is given to the use of the reaction product comprising a quaternized nitrogen compound over the use of the component fraction thereof obtained by purification.
Test methods suitable in each case for verification of the above-designated applications are known to those skilled in the art, or are described in the experimental section which follows, to which general reference is hereby made explicitly.
In the absence of statements to the contrary, the following general definitions apply:
“Quaternizable” nitrogen groups or amino groups comprise especially primary, secondary and, in particular, tertiary amino groups.
“Hydrocarbyl” should be interpreted broadly and comprises both long-chain and short-chain, straight-chain and branched hydrocarbyl radicals having 1 to 50 carbon atoms, which may optionally additionally comprise heteroatoms, for example O, N, NH, S, in the chain thereof. A specific group of hydrocarbyl radicals comprises both long-chain and short-chain, straight-chain or branched alkyl radicals having 1 to 1000, 3 to 500 4 to 400 carbon atoms.
“Long-chain” or “high molecular weight” hydrocarbyl radicals are straight-chain or branched hydrocarbyl radicals and have 7 to 50 or 8 to 50 or 8 to 40 or 10 to 20 carbon atoms, which may optionally additionally comprise heteroatoms, for example O, N, NH, S, in the chain thereof. In addition, the radicals may be mono- or polyunsaturated and have one or more noncumulated, for example 1 to 5, such as 1, 2 or 3, C═C double bonds or C—C triple bonds, especially 1, 2 or 3 double bonds. They may be of natural or synthetic origin.
They may also have a number-average molecular weight (Mn) of 85 to 20 000, for example 113 to 10 000, or 200 to 10 000 or 350 to 5000, for example 350 to 3000, 500 to 2500, 700 to 2500, or 800 to 1500. In that case, they are more particularly formed essentially from C2-6, especially C2-4, monomer units such as ethylene, propylene, n- or isobutylene or mixtures thereof, where the different monomers may be copolymerized in random distribution or as blocks. Such long-chain hydrocarbyl radicals are also referred to as polyalkylene radicals or poly-C2-6- or poly-C2-4-alkylene radicals. Suitable long-chain hydrocarbyl radicals and the preparation thereof are also described, for example, in WO 2006/135881 and the literature cited therein.
Examples of particularly useful polyalkylene radicals are polyisobutenyl radicals derived from what are called “high-reactivity” polyisobutenes which feature a high content of terminal double bonds. Terminal double bonds are alpha-olefinic double bonds of the type
which are also referred to collectively as vinylidene double bonds. Suitable high-reactivity polyisobutenes are, for example, polyisobutenes which have a proportion of vinylidene double bonds of greater than 70 mol %, especially greater than 80 mol % or greater than 85 mol %. Preference is given especially to polyisobutenes which have homogeneous polymer skeletons. Homogeneous polymer skeletons are possessed especially by those polyisobutenes formed from isobutene units to an extent of at least 85% by weight, preferably to an extent of at least 90% by weight and more preferably to an extent of at least 95% by weight. Such high-reactivity polyisobutenes preferably have a number-average molecular weight within the abovementioned range. In addition, the high-reactivity polyisobutenes may have a polydispersity in the range from 1.05 to 7, especially of about 1.1 to 2.5, for example of less than 1.9 or less than 1.5. Polydispersity is understood to mean the quotient of weight-average molecular weight Mw divided by the number-average molecular weight Mn.
Particularly suitable high-reactivity polyisobutenes are, for example, the Glissopal brands from BASF SE, especially Glissopal) 1000 (Mn=1000), Glissopal® V 33 (Mn=550), and Glissopal® 2300 (Mn=2300), and mixtures thereof. Other number-average molecular weights can be established in a manner known in principle by mixing polyisobutenes of different number-average molecular weights or by extractive enrichment of polyisobutenes of particular molecular weight ranges.
A specific group of long-chain hydrocarbyl radicals comprises straight-chain or branched alkyl radicals (“long-chain alkyl radicals”) having 8 to 50, for example 8 to 40 or 8 to 30 or 10 to 20, carbon atoms.
A further group of specific long-chain hydrocarbyl radicals comprises polyalkylene radicals which are especially formed essentially from C2-6, especially C2-4, monomer units, such as ethylene, propylene, n- or isobutylene or mixtures thereof and have a degree of polymerization of 2 to 100, or 3 to 50 or 4 to 25.
“Short-chain hydrocarbyl” or “low molecular weight hydrocarbyl” is especially straight-chain or branched alkyl or alkenyl, optionally interrupted by one or more, for example 2, 3 or 4, heteroatom groups such as —O— or —NH—, or optionally mono- or polysubstituted, for example di-, tri- or tetrasubstituted.
“Hydrocarbylene” represents straight-chain or singly or multiply branched bridge groups having 1 to 10 carbon atoms, optionally interrupted by one or more, for example 2, 3 or 4, heteroatom groups such as —O— or —NH—, or optionally mono- or polysubstituted, for example di-, tri- or tetrasubstituted.
“Alkyl” or “lower alkyl” represents especially saturated, straight-chain or branched hydrocarbon radicals having 1 to 4, 1 to 5, 1 to 6, or 1 to 7, carbon atoms, for example methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl and 1-ethyl-2-methylpropyl; and also n-heptyl, and the singly or multiply branched analogs thereof.
“Long-chain alkyl” represents, for example, saturated straight-chain or branched hydrocarbyl radicals having 8 to 50, for example 8 to 40 or 8 to 30 or 10 to 20, carbon atoms, such as octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, squalyl, constitutional isomers, especially singly or multiply branched isomers and higher homologs thereof.
“Hydroxyalkyl” represents especially the mono- or polyhydroxylated, especially monohydroxylated, analogs of the above alkyl radicals, for example the monohydroxylated analogs of the above straight-chain or branched alkyl radicals, for example the linear hydroxyalkyl groups, for example those having a primary (terminal) hydroxyl group, such as hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, or those having nonterminal hydroxyl groups, such as 1-hydroxyethyl, 1- or 2-hydroxypropyl, 1- or 2-hydroxybutyl or 1-, 2- or 3-hydroxybutyl.
“Alkenyl” represents mono- or polyunsaturated, especially monounsaturated, straight-chain or branched hydrocarbyl radicals having 2 to 4, 2 to 6, or 2 to 7 carbon atoms and one double bond in any position, e.g. C2-C6-alkenyl such as ethenyl, 1-propenyl, 2-propenyl, 1-methylethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, I-methyl-2-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1,3-dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-1-butenyl, 3,3-dimethyl-2-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-trimethyl-2-propenyl, 1-ethyl-1-methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl and 1-ethyl-2-methyl-2-propenyl.
“Hydroxyalkenyl” represents especially the mono- or polyhydroxylated, especially monohydroxylated, analogs of the above alkenyl radicals.
“Aminoalkyl” and “aminoalkenyl” represent especially the mono- or polyaminated, especially monoaminated, analogs of the above alkyl and alkenyl radicals respectively, or analogs of the above hydroxyalkyl where the OH group has been replaced by an amino group.
“Alkylene” represents straight-chain or singly or multiply branched hydrocarbyl bridging groups having 1 to 10 carbon atoms, for example C1-C7-alkylene groups selected from —CH—, —(CH2)2—, —(CH2)3—, —(CH2)4—, —(CH2)2—CH(CH3)—, —CH2—CH(CH3)—CH2, (CH2)4—, —(CH2)5—, —(CH2)6, —(CH2)7—, —CH(CH3)—CH2—CH2—CH(CH3)— or —CH(CH3)—CH2—CH2—CH2—CH(CH3)— or C1-C4-alkylene groups selected from —CH2—, —(CH2)2—, —(CH2)3—, —(CH2)4—, —(CH2)2—CH(CH3)—, —CH2—CH(CH3)—CH2—or C2-C6-alkylene groups, for example
—CH2—CH(CH3)—, —CH(CH3)—CH2, —CH(CH3)—CH(CH3)—, —C(CH3)2—CH2—, —CH2—C(CH3)2—, —C(CH3)2—CH(CH3)—, —CH(CH3)—C(CH3)2—, —CH2—CH(Et)-, —CH(CH2CH3)—CH2—, —CH(CH2CH3)—CH(CH2CH3)—, —C(CH2CH3)2CH2—, —CH2—C(CH2CH3)2—, —CH2—CH(n-propyl)-, —CH(n-propyl)-CH2—, —CH(n-propyl)—CH(CH3)—, —CH2—CH(n-butyl)-, —CH(n-butyl)-CH2—, —CH(CH3)—CH(CH2CH3)—, —CH(CH3)—CH(n-propyl)-, —CH(CH2CH3)—CH(CH3)—, —CH(CH3)—CH(CH2CH3)—, or C2-C4-alkylene groups, for example selected from —(CH2)2—, —CH2—CH(CH3)—, —CH(CH3)—CH2—, —CH(CH3)—CH(CH3)—, —C(CH3)2—CH2—, —CH2—C(CH3)2—, —CH2—CH(CH2CH3)—, —CH(CH2CH3)—CH2—.
Oxyalkylene radicals correspond to the definition of the above straight-chain or singly or multiply branched alkylene radicals having 2 to 10 carbon atoms, where the carbon chain may be interrupted once or more than once, especially once, by an oxygen heteroatom. Nonlimiting examples include: —CH2—O—CH2—, —(CH2)2—O—(CH2)2—, —(CH2)3—O—(CH2)3—, or —CH2—O—(CH2)2—, —(CH2)2—O—(CH2)3—, —CH2—O—(CH2)3.
Aminoalkylene corresponds to the definition of the above straight-chain or singly or multiply branched alkylene radicals having 2 to 10 carbon atoms, where the carbon chain may be interrupted once or more than once, especially once, by a nitrogen group (especially —NH-group). Nonlimiting examples include: —CH2NH—CH2—, —(CH2)2—NH—(CH2)2—, —(CH2)3—NH—(CH2)3—, or —CH2—NH—(CH2)2—, —(CH2)2—NH—(CH2)3—, —CH2—NH—(CH2)3.
“Alkenylene” represents the mono- or polyunsaturated, especially monounsaturated, analogs of the above alkylene groups having 2 to 10 carbon atoms, especially C2-C7-alkenylenes or C2-C4-alkenylene, such as —CH═CH—, —CH═CH—CH2—, —CH2—CH═CH—, —CH═CH—CH2—CH2—, —CH2—CH═CH—CH2—, —CH2—CH2—CH═CH—, —CH(CH3)—CH═CH—, —CH2—C(CH3)═CH—.
“Cycloalkyl” represents carbocyclic radicals having 3 to 20 carbon atoms, for example C3-C12-cycloalkyl such as cyclopropyl, cydobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and cyclododecyl; preference is given to cyclopentyl, cyclohexyl, cycloheptyl, and also to cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, or C3-C7-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclopentylethyl, cyclohexylmethyl, where the bond to the rest of the molecule may be via any suitable carbon atom.
“Cydoalkenyl” or mono- or polyunsaturated cycloalkyl represents especially monocyclic, mono- or polyunsaturated hydrocarbyl groups having 5 to 8, preferably to 6, carbon ring members, for example the monounsaturated radicals cyclopenten-1-yl, cyclopenten-3-yl, cyclohexen-1-yl, cyclohexen-3-yl and cyclohexen-4-yl.
“Aryl” represents mono- or polycyclic, preferably mono- or bicyclic, optionally substituted aromatic radicals having 6 to 20, for example 6 to 10, ring carbon atoms, for example phenyl, biphenyl, naphthyl such as 1- or 2-naphthyl, tetrahydronaphthyl, fluorenyl, indenyl and phenanthrenyl. These aryl radicals may optionally bear 1, 2, 3, 4, 5 or 6 identical or different substituents.
“Alkylaryl” represents analogs of the above aryl radicals mono- or polyalkyl-substituted, especially mono- or dialkyl-substituted, in any ring position, where aryl is likewise as defined above, for example C1-C4-alkylphenyl, where the C1-C4-alkyl radicals may be in any ring position.
“Substituents” for radicals specified herein are especially, unless stated otherwise, selected from keto groups, —COOH, —COO-alkyl, —OH, —SH, —CN, amino, —NO2, alkyl, or alkenyl groups.
“Mn” represents the number-average molecular weight and is determined in a conventional manner; more particularly, such figures relate to Mn values determined by relative methods, such as gel permeation chromatography with THF as the eluent and polystyrene standards, or absolute methods, such as vapor phase osmometry using toluene as the solvent.
“Mw” represents the weight-average molecular weight and is determined in a conventional manner; more particularly, such figures relate to Mw values determined by relative methods, such as gel permeation chromatography with THF as the eluent and polystyrene standards, or absolute methods, such as light scattering.
The “degree of polymerization” usually refers to the numerical mean degree of polymerization (determination method: gel permeation chromatography with THF as the eluent and polystyrene standards; or GC-MS coupling).
Quaternizable nitrogen compounds are especially:
Tertiary amines are especially compounds of the above formula (3) and are compounds known per se, as described, for example, in EP-A-2 033 945.
The tertiary amine reactant (3) preferably bears a segment of the formula NRaRb where one of the radicals has an alkyl group having 8 to 40 carbon atoms and the other an alkyl group having up to 40 and more preferably 8 to 40 carbon atoms. The Rc radical is especially a short-chain C1-C6-alkyl radical, such as a methyl, ethyl or propyl group. Ra and Rb may be straight-chain or branched, and/or may be the same or different. For example, Ra and Rb may be a straight-chain C12-C24-alkyl group. Alternatively, only one of the two radicals may be long-chain (for example having 8 to 40 carbon atoms), and the other may be a methyl, ethyl or propyl group.
Appropriately, the NRaRb segment is derived from a secondary amine, such as dioctadecylamine, dicocoamine, hydrogenated ditallowamine and methylbehenylamine. Amine mixtures as obtainable from natural materials are likewise suitable. One example is a secondary hydrogenated tallowamine where the alkyl groups are derived from hydrogenated tallow fat, and contain about 4% by weight of C14, 31% by weight of C16 and 59% by weight of C18-alkyl groups. Corresponding tertiary amines of the formula (3) are sold, for example, by Akzo Nobel under the Armeen® M2HT or Armeen® M2C name.
However, the tertiary amine reactant (3) may also be one where the Ra, Rb and Rc radicals have identical or different long-chain alkyl radicals, especially straight-chain or branched alkyl groups having 8 to 40 carbon atoms.
However, the tertiary amine reactant (3) may also be one where the Ra, Rb and Rc radicals have identical or different short-chain alkyl radicals, especially straight-chain or branched alkyl groups having 1 to 7 or especially 1 to 4 carbon atoms.
Further nonlimiting examples of suitable amines are:
N,N-dimethyl-N-(2-ethylhexyl)amine, N,N-dimethyl-N-(2-propylheptyl)amine, dodecyl-dimethylamine, hexadecyldimethylamine, oleyldimethylamine, stearyldimethylamine, heptadecyldimethylamine, cocoyldimethylamine, dicocoylmethylamine, tallowdimethylamine, ditallowmethylamine, tridodecylamine, trihexadecylamine, trioctadecylamine, soyadimethylamine, tris(2-ethylhexyl)amine, and Alamine 336 (tri-n-octylamine).
Nonlimiting examples of short-chain tertiary amines are: trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, ethyldimethylamine, dimethylethylamine, n-propyldimethylamine, isopropyldimethylamine, n-propyldiethylamine, isopropyldiethylamine, n-butyldimethylamine, n-butyldiethylamine. n-butyldipropylamine.
Short-chain triamines are also appropriate especially when the quaternizing agent (see below) bears one or more alkyl radicals Rd having more than one carbon atom or one or more aromatic radicals Rd.
Compounds of this kind are described, for example, in the applicant's WO2013/064689, which is hereby explicitly incorporated by reference.
Substituted amines of this kind especially have at least one, especially one, polyether substituent having monomer units of the general formula Ic
—[(—CH(R3)—CH(R4)—O—]- (Ic)
in which
R3 and R4 are the same or different and are each H, alkyl, alkylaryl or aryl.
The polyether-substituted amine may have a number-average molecular weight in the range from 500 to 5000, especially 800 to 3000 or 900 to 1500.
The quaternizable, polyether-substituted amines are especially nitrogen compounds of the general formula Ia-1 or Ib-2
(R1)(R2)N-A-OCH(R3)—CH(R4)—OnH (Ia-1)
R6—OCH(R3)—CH(R4)—OCH(R3)—CH(R4)—N(R1)(R2) (Ib-2)
in which
R1 and R2 are the same or different and are each alkyl, alkenyl, hydroxyalkyl, hydroxyalkenyl, aminoalkyl or aminoalkenyl, or R1 and R2 together are alkylene, oxyalkylene or aminoalkylene;
R3 and R4 are the same or different and are each H, alkyl, alkylaryl or aryl:
R6 is alkyl, alkenyl, optionally mono- or polyunsaturated cycloalkyl, aryl, in each case optionally substituted, for example by at least one hydroxyl radical or alkyl radical, or interrupted by at least one heteroatom;
A is a straight-chain or branched alkylene radical optionally interrupted by one or more heteroatoms such as N, O and S; and
n is an integer value from 1 to 50.
Particular mention should be made of those nitrogen compounds of the formulae Ia-1 and Ib-2 in which
R1 and R2 are the same or different and are each C1-C6-alkyl, hydroxy-C1-C6-alkyl, hydroxy-C1-C6-alkenyl, or amino-C1-C6-alkyl, or R1 and R2 together form a C2-C6-alkylene, C2-C6-oxyalkylene or C2-C6-aminoalkylene radical;
R3 and R4 are the same or different and are each H, C1-C6-alkyl or phenyl;
R6 is C1-C20-alkyl, for example C10-C20-, C11-C20- or C12-C20-alkyl or aryl or alkylaryl, where alkyl is especially C1-C20-;
A is a straight-chain or branched C2-C6-alkylene radical optionally interrupted by one or more heteroatoms such as N, O and S; and
n is an integer value from 1 to 30.
Particular mention should additionally be made of reaction products of N,N-dimethylethanolamine and propylene oxide, as described in Synthesis example 1 of WO 2013/064689. This reaction can also be performed without catalysis or with an amine (for example imidazole) as a catalyst, as described, for example, in M. Ionescu, Chemistry and Technology of Polyols for Polyurethanes, 2005, ISBN 978-85957-501-7.
Nitrogen compounds of the general formula Ia-1 are preparable by alkoxylating an aminoalkanol of the general formula II
(R1)(R2)N-A-OH (II)
in which
R1, R2 and A are each as defined above
with an epoxide of the general formula III
in which
R3 and R4 are each as defined above
to obtain an alkoxylated amine of the formula
(R1)(R2)N-A-OCH(R3)—CH(R4)—O—nH (Ia-1)
in which R1 to R4, A and n are each as defined above.
Nitrogen compounds of the general formula Ia-2 are preparable by alkoxylating an alcohol of the general formula V
R6—OH (V)
in which
R6 is as defined above with an epoxide of the general formula III
in which
R3 and R4 are each as defined above to obtain a polyether of the formula Ib-1;
R6—O└CH(R3)—CH(R4)—On-1CH(R3)—CH(R4)OH (Ib-1)
in which R3, R4 and R6, A and n are each as defined above
and
b) then aminating the polyether of the formula Ib-1 thus obtained with an amine of the general formula
NH(R1)(R2) (VII)
in which R1 and R2 are each as defined above
to obtain an amine of the formula Ib-2.
Starting compounds for preparation of the above polyether-substituted, quaternizable nitrogen compounds are thus:
1) alcohols,
for example of the general formula V
R6—OH (V)
in which R6 is alkyl, alkenyl, optionally mono- or polyunsaturated cycloalkyl, aryl, in each case optionally substituted, for example by at least one hydroxyl radical or alkyl radical, or interrupted by at least one heteroatom;
and
2) amino alkanols,
for example of the general formula II
(R1)(R2)N-A-OH (II)
in which
R1 and R2 are the same or different and are each alkyl, alkenyl, hydroxyalkyl, hydroxyalkenyl, aminoalkyl or aminoalkenyl, or R1 and R2 together are alkylene, oxyalkylene or aminoalkylene; and
A is a straight-chain or branched alkylene or alkenylene radical optionally interrupted by one or more heteroatoms such as N, O and S.
A further suitable group of quaternizable amino alcohols that should be mentioned is that of compounds selected from hydroxyalkyl-substituted mono- or polyamines having at least one quaternizable, primary, secondary or tertiary amino group and at least one hydroxyl group which can be joined to a polyether radical.
The quaternizable nitrogen compound is especially selected from hydroxyalkyl-substituted primary, secondary and especially tertiary monoamines, and hydroxyalkyl-substituted primary, secondary and especially tertiary diamines.
Examples of suitable “hydroxyalkyl-substituted mono- or polyamines” are those provided with at least one hydroxyalkyl substituted, for example 1, 2, 3, 4, 5 or 6 hydroxyalkyl substituted.
Examples of “hydroxyalkyl-substituted monoamines” include: N-hydroxyalkylmonoamines, N,N-dihydroxyalkylmonoamines and N,N,N-trihydroxyalkylmonoamines, where the hydroxyalkyl groups are the same or different and are also as defined above. Hydroxyalkyl is especially 2-hydroxyethyl, 3-hydroxypropyl or 4-hydroxybutyl.
For example, the following “hydroxyalkyl-substituted polyamines” and especially “hydroxyalkyl-substituted diamines” may be mentioned: N-hydroxyalkylalkylenediamines, N,N-dihydroxyalkylalkyenediamines, where the hydroxyalkyl groups are the same or different and are also as defined above. Hydroxyalkyl is especially 2-hydroxyethyl, 3-hydroxypropyl or 4-hydroxybutyl; alkylene is especially ethylene, propylene or butylene.
Particular mention should be made of the following quaternizable nitrogen compounds:
For preparation of the polyether-substituted quaternizable compounds (Ia-1 and Ib-1), the procedure may be as follows:
a1) Proceeding from Amino Alcohols of the Formula II:
The amino alcohols of the general formula II can be alkoxylated in a manner known in principle to obtain alkoxylated amines of the general formula Ia-1.
The performance of alkoxylations is known in principle to those skilled in the art. It is likewise known to those skilled in the art that the reaction conditions, especially the selection of the catalyst, can influence the molecular weight distribution of the alkoxylates.
For the alkoxylation, C2-C16-alkylene oxides are used, for example ethylene oxide, propylene oxide or butylene oxide. Preference is given to the 1,2-alkylene oxides in each case.
The alkoxylation may be a base-catalyzed alkoxylation. For this purpose, the amino alcohols (II) can be admixed in a pressure reactor with alkali metal hydroxides, preferably potassium hydroxide, or with alkali metal alkoxides, for example sodium methoxide. Water still present in the mixture can be drawn off by means of reduced pressure (for example <100 mbar) and/or increasing the temperature (30 to 150° C.). Thereafter, the alcohol is present in the form of the corresponding alkoxide. This is followed by inertization with inert gas (for example nitrogen) and stepwise addition of the alkylene oxide(s) at temperatures of 60 to 180° C. up to a pressure of max. 10 bar. At the end of the reaction, the catalyst can be neutralized by adding acid (e.g. acetic acid or phosphoric acid) and can be filtered off if required. The basic catalyst can also be neutralized by addition of commercial magnesium silicates, which are subsequently filtered off. Optionally, the alkoxylation can also be performed in the presence of a solvent. This may be, for example, toluene, xylene, dimethylformamide or ethylene carbonate.
The alkoxylation of the amino alcohols can also be undertaken by means of other methods, for example by acid-catalyzed alkoxylation. In addition, it is possible to use, for example, double hydroxide days, as described in DE 43 25 237 A1, or it is possible to use double metal cyanide catalysts (DMC catalysts). Suitable DMC catalysts are disclosed, for example, in DE 102 43 361 A1, especially paragraphs [0029] to [0041] and the literature cited therein. For example, it is possible to use catalysts of the Zn—Co type. To perform the reaction, the amino alcohol can be admixed with the catalyst, and the mixture dewatered as described above and reacted with the alkylene oxides as described. Typically not more than 1000 ppm of catalyst based on the mixture are used, and the catalyst can remain in the product owing to this small amount. The amount of catalyst may generally be less than 1000 ppm, for example 250 ppm or less.
The alkoxylation can alternatively also be undertaken by reaction of the compounds (IV) and (V) with cyclic carbonates, for example ethylene carbonate.
a2) Proceeding from Alkanols of the Formula V:
As described in the above paragraph al) for amino alcohols (II), it is analogously also possible to alkoxylate alkanols R6OH in a manner known in principle to polyethers (Ib-1). The polyethers thus obtained can subsequently be converted to the corresponding polyether amines (Ib-2) by reductive amination with ammonia, primary amines or secondary amines (VII) by customary methods, in continuous or batchwise processes using hydrogenation or amination catalysts customary therefor, for example those comprising catalytically active constituents based on the elements Ni, Co, Cu, Fe, Pd, Pt, Ru, Rh, Re, Al, Si, Ti, Zr, Nb, Mg, Zn, Ag, Au, Os, Ir, Cr, Mo, W or combinations of these elements with one another, in customary amounts. The conversion can be performed without solvent or, in the case of high polyether viscosities, in the presence of a solvent, preferably in the presence of branched aliphatics, for example isododecane. The amine component (VII) is generally used here in excess, for example in a 2- to 100-fold excess, preferably a 10- to 80-fold excess. The reaction is conducted at pressures of 10 to 600 bar over a period of 10 minutes to 10 hours. After cooling, the catalyst is removed by filtering, excess amine component (VII) is evaporated and the water of reaction is distilled off azeotropically or under a gentle nitrogen stream.
Should the resulting polyether amine (Ib-2) have primary or secondary amine functionalities (R1 and/or R2 is H), it can subsequently be converted to a polyether amine having a tertiary amine function (R1 and R2 not H). The alkylation can be effected in a manner known in principle by reaction with alkylating agents. Any alkylating agents are suitable in principle, for example alkyl halides, alkylaryl halides, dialkyl sulfates, alkylene oxides, optionally in combination with acid; aliphatic or aromatic carboxylic esters, such as dialkyl carboxylates in particular; alkanoates; cyclic nonaromatic or aromatic carboxylic esters; dialkyl carbonates; and mixtures thereof. The conversions to the tertiary polyether amine can also take place through reductive amination by reaction with a carbonyl compound, for example formaldehyde, in the presence of a reducing agent. Suitable reducing agents are formic acid or hydrogen in the presence of a suitable heterogeneous or homogeneous hydrogenation catalyst. The reactions can be performed without solvent or in the presence of solvents. Suitable solvents are, for example, H2O, alkanols such as methanol or ethanol, or 2-ethylhexanol, aromatic solvents such as toluene, xylene or solvent mixtures from the Solvesso series, or aliphatic solvents, especially mixtures of branched aliphatic solvents. The reactions are conducted at temperatures of 10° C. to 300° C. at pressures of 1 to 600 bar over a period of 10 minutes to 10 h. The reducing agent is used here at least stoichiometrically, preferably in excess, especially in a 2- to 10-fold excess.
The reaction product thus formed (polyether amine Ib-1 or Ib-2) can theoretically be purified further, or the solvent can be removed. Usually, however, this is not absolutely necessary, and so the reaction product can be transferred without further purification into the next synthesis step, the quaternization.
Further suitable quaternizable nitrogen compounds are polyalkene-substituted amines having at least one tertiary nitrogen group. This group of compounds is likewise known and is described, for example, in WO 2008/060888 or US 2008/0113890 and the further prior art cited therein, which is hereby explicitly incorporated by reference.
Such polyalkene-substituted amines having at least one tertiary amino group are derivable from an olefin polymer and an amine such as ammonia, monoamines, polyamines or mixtures thereof. They can be prepared by a multitude of processes, for example the following processes cited by way of example:
A process for preparing a polyalkene-substituted amine comprises the reaction of a halogenated olefin polymer with an amine, as described in U.S. Pat. Nos. 3,275,554, 3,438,757, 3,454,555, 3,565,804, 3,755,433 and 3,822,289.
A further process for preparing a polyalkene-substituted amine comprises the reaction of a hydroformylated olefin with a polyamine and hydrogenation of the reaction product, as described in U.S. Pat. Nos. 5,567,845 and 5,496,383.
A further process for preparing a polyalkene-substituted amine comprises the conversion of a polyalkene with the aid of a conventional epoxidizing reagent with or without catalyst to the corresponding epoxide and the conversion of the epoxide to the polyalkene-substituted amine by reaction with ammonia or an amine under the conditions of reductive amination, as described in U.S. Pat. No. 5,350,429.
A further process for preparing a polyalkene-substituted amine comprises the hydrogenation of a β-amino nitrile which has been prepared by reaction of an amine with a nitrile, as described in U.S. Pat. No. 5,492,641.
A further process for preparing a polyalkene-substituted amine comprises hydroformylation of a polybutene or polyisobutylene with a catalyst, such as rhodium or cobalt, in the presence of CO and hydrogen at elevated pressures and temperatures, as described in U.S. Pat. No. 4,832,702.
In one embodiment of the invention, the polyalkenes used for the preparation are derived from olefin polymers. The olefin polymers may comprise homopolymers and co-polymers of polymerizable olefin monomers having 2 to about 16 carbon atoms, 2 to about 6 carbon atoms or 2 to about 4 carbon atoms.
Interpolymers are those in which two or more olefin monomers are interpolymerized by known conventional methods, giving polyalkenes having units derived from each of the two or more olefin monomers within their structure. Thus, “interpolymers” comprise copolymers, terpolymers and tetrapolymers.
“Polyalkenes”, from which the polyalkene-substituted amines are derived, are conventionally frequently also referred to as “polyolefins”.
The olefin monomers from which the olefin polymers are derived are polymerizable olefin monomers having one or more ethylenically unsaturated groups (i.e. >C═C<); in other words, they are monoolefinic monomers such as ethylene, propylene, 1-butene, isobutene (2-methyl-1-butene), 1-octene, or polyolefinic monomers (usually diolefinic monomers) such as 1,3-butadiene and isoprene.
The olefin monomers are usually polymerizable terminal olefins, i.e. olefins having the >C═CH2 group in their structure. However, it is also possible to use polymerizable internal olefin monomers characterized by groups of the formula >C—C═C—C<.
Specific examples of terminal and internal olefin monomers which can be used to prepare the polyalkenes by conventional methods are: ethylene, propylene, the butenes (butylene), especially 1-butene, 2-butene and isobutylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 2-pentene, propylene tetramer, diisobutylene, isobutylene trimer, 1,2-butadiene, 1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 1,4-pentadiene, isoprene, 1,5-hexadiene, 2-methyl-5-propyl-1-hexene, 3-pentene, 4-octene and 3,3-dimethyl-1-pentene.
In another embodiment, the olefin polymer is preparable by polymerization of a C4 refinery stream having a butene content of about 35 to about 75 percent by weight and an isobutene content of about 30 to about 60 percent by weight in the presence of a Lewis acid catalyst such as aluminum trichloride or boron trifluoride. These polybutenes typically comprise predominantly (more than about 80% of all the repeat units) repeat isobutene units of the (—CH2—C(CH3)2—) type.
In a further embodiment, the polyalkene substituent of the polyalkene-substituted amine is derived from a polyisobutylene.
In another embodiment, the amines which can be used to form the polyalkene-substituted amine comprise ammonia, monoamines, polyamines or mixtures thereof, including mixtures of various monoamines, mixtures of various polyamines and mixtures of monoamines and polyamines (the diamines). The amines comprise aliphatic, aromatic, heterocyclic and carbocyclic amines. Monoamines and polyamines are characterized by the presence in their structure of at least one HN< group. The amines may be aliphatic, cycloaliphatic, aromatic or heterocyclic.
The monoamines are generally substituted by a hydrocarbyl group having 1 to 50 carbon atoms. These hydrocarbyl groups may especially be aliphatic and free of acetylenically unsaturated groups and have 1 to about 30 carbon atoms. Particular mention should be made of saturated aliphatic hydrocarbyl radicals having 1 to 30 carbon atoms.
In a further embodiment, the monoamines may have the formula HNR1R2 where R1 is a hydrocarbyl group having up to 30 carbon atoms and R2 is hydrogen or a hydrocarbyl group having up to about 30 carbon atoms. Examples of suitable monoamines are methylamine, ethylamine, diethylamine, 2-ethylhexylamine, di(2-ethylhexyl)amine, n-butylamine, di-n-butylamine, allylamine, isobutylamine, cocoamine, stearylamine, laurylamine, methyllaurylamines and oleylamine.
Aromatic monoamines are those monoamines in which a carbon atom in the aromatic ring structure is bonded directly to the amine nitrogen atom. The aromatic ring will usually be a monocyclic aromatic ring (i.e. derived from benzene), but may include fused aromatic rings, especially those derived from naphthalene. Examples of aromatic monoamines are aniline, di(para-methylphenyl)amine, naphthylamine, N-(n-butyl)aniline. Examples of aliphatic-substituted, cycloaliphatic-substituted and heterocyclic-substituted aromatic monoamines are: para-dodecylaniline, cyclohexyl-substituted naphthylamine and thienyl-substituted aniline.
Hydroxylamines are likewise suitable monoamines. Compounds of this kind are the hydroxyhydrocarbyl-substituted analogs of the aforementioned monoamines.
In one embodiment, the hydroxy monoamines are those of the formula HNR3R4 where R3 is a hydroxyl-substituted alkyl group having up to about 30 carbon atoms, and in one embodiment up to about 10 carbon atoms; and R4 is a hydroxyl-substituted alkyl group having up to about 30 carbon atoms, hydrogen or a hydrocarbyl group having up to about 10 carbon atoms. Examples of hydroxyl-substituted monoamines include: ethanolamine, di-3-propanolamine, 4-hydroxybutylamine, diethanolamine and N-methyl-2-hydroxypropylamine.
In another embodiment, the amine of the polyalkene-substituted amines may be a polyamine. The polyamine may be aliphatic, cycloaliphatic, heterocyclic or aromatic. Examples of the polyamines include: alkylenepolyamines, hydroxyl group-comprising polyamines, aryl polyamines and heterocyclic polyamines.
The alkylenepolyamines comprise those of the following formula:
HN(R5)-(alkylene-N(R5))n—(R5)
in which n is in the range from 1 to about 10 and, for example, in the range from 2 to about 7, or from 2 to about 5, and the “alkylene” group has 1 to about 10 carbon atoms, for example 2 to about 6, or 2 to about 4 carbon atoms;
the R5 radicals are each independently hydrogen, an aliphatic group, a hydroxyl- or amine-substituted aliphatic group of up to about 30 carbon atoms in each case. Typically, R5 is H or lower alkyl (an alkyl group having 1 to about 5 carbon atoms), especially H. Alkylenepolyamines of this kind include: methylenepolyamines, ethylenepolyamines, butylenepolyamines, propylenepolyamines, pentylenepolyamines, hexylenepolyamines and heptylenepolyamines. The higher homologs of such amines and related aminoalkyl-substituted piperazines are likewise included.
Specific alkylenepolyamines for preparation of the polyalkene-substituted amines are the following: ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, propylenediamine, 3-dimethylaminopropylamine, trimethylenediamine, hexamethylenediamine, decamethylenediamine, octamethylenediamine, di(heptamethylene)triamine, tripropylenetetramine, pentaethylenehexamine, di(trimethylenetriamine), N-(2-aminoethyl)piperazine and 1,4-bis(2-aminoethyl)piperazine.
Ethylenepolyamines, such as those mentioned above, are particularly suitable for reasons of cost and effectiveness. Polyamines of this kind are described in detail in the chapter “Diamine und höhere Amine” [Diamines and Higher Amines] in Encyclopedia of Chemical Technology, second edition, Kirk-Othmer, volume 7, pages 27-39, Inter-science Publishers, division of John Wiley & Sons, 1965. Compounds of this kind are most conveniently prepared by the reaction of an alkylene chloride with ammonia or by reaction of an ethyleneimine with a ring-opening reagent such as ammonia. These reactions lead to preparation of complex mixtures of alkylenepolyamines, including cyclic condensation products such as piperazines.
Other suitable types of polyamine mixtures are the products which are formed as residue by stripping the above-described polyamine mixtures and are frequently referred to as “polyamine bottoms”. In general, alkylenepolyamine bottom products are those which comprise less than two, usually less than 1%, by weight of material that boils below about 200° C. A typical example of such ethylenepolyamine bottoms is that of the products designated “E 100” from Dow Chemical Company in Freeport, Tex. These alkylenepolyamine bottoms comprise cyclic condensation products such as piperazine and higher analogs of diethylenetriamine, triethylenetetramines and the like.
Hydroxyl group-comprising polyamines include: hydroxyalkylalkylenepolyamines having one or more hydroxyalkyl substituents on the nitrogen atoms. Polyamines of this kind can be prepared by reacting the above-described alkylenepolyamines with one or more alkylene oxides (e.g. ethylene oxide, propylene oxide and butylene oxide). Similar alkylene oxide-alkanolamine reaction products may also, for example, be the products of the reaction of primary, secondary or tertiary alkanolamines with ethylene, propylene or higher epoxides in a molar ratio of 1:1 to 1:2. Reactant ratios and temperatures for performance of such reactions are known to those skilled in the art.
In another embodiment, the hydroxyalkyl-substituted alkylenepolyamine may be a compound in which the hydroxyalkyl group is a hydroxy-lower alkyl group, i.e. has fewer than eight carbon atoms. Examples of such hydroxyalkyl-substituted polyamines include N-(2-hydroxyethyl)ethylenediamine (also known as 2-(2-aminoethylamino)ethanol), N,N-bis(2-hydroxyethyl)ethylenediamine, 1-(2-hydroxyethyl)piperazine, monohydroxypropyl-substituted diethylenetriamine, dihydroxypropyl-substituted tetraethylenepentamine and N-(3-hydroxybutyl)tetramethylenediamine.
Aryl polyamines are analogs of the abovementioned aromatic monoamines. Examples of aryl polyamines include: N,N′-di-n-butyl-para-phenylenediamine and bis(para-aminophenyl)methane.
Heterocyclic mono- and polyamines may comprise: aziridines, azetidines, azolidines, pyridines, pyrroles, indoles, piperidines, imidazoles, piperazines, isoindoles, purines, morpholines, thiomorpholines, N-aminoalkylmorpholines, N-aminoalkylthiomorpholines, N-aminoalkylpiperazines, N,N′-diaminoalkylpiperazines, azepines, azocines, azonines, azecines and tetra-, di- and perhydro derivatives of each of the above compounds and mixtures of two or more of these heterocyclic amines. Typical heterocyclic amines are saturated 5- and 6-membered heterocyclic amines having only nitrogen, oxygen and/or sulfur in the heterocycle, especially piperidines, piperazines, thiomorpholines, morpholines, pyrrolidines and the like. Piperidine, aminoalkyl-substituted piperidines, piperazine, aminoalkyl-substituted piperazines, morpholine, aminoalkyl-substituted morpholines, pyrrolidine and aminoalkyl-substituted pyrrolidines are particularly preferred. Usually, the aminoalkyl substituents are bonded to a nitrogen atom which is part of the heterocycle.
Specific examples of such heterocyclic amines include N-aminopropylmorpholine. N-aminoethylpiperazine and N,N′-diaminoethylpiperazine. Hydroxyheterocyclic polyamines are also suitable. Examples include: N-(2-hydroxyethyl)cyclohexylamine, 3-hydroxycyclopentylamine, para-hydroxyaniline and N-hydroxyethylpiperazine.
Examples of polyalkene-substituted amines are as follows: poly(propylene)amine, poly(butene)amine, N,N-dimethylpolyisobutyleneamines; polybutenemorpholines, N,N-poly(butene)ethylenediamine, N-poly(propylene)trimethylenediamine, N-poly(butene), diethylenetriamine, N′,N′-poly(butene)tetraethylenepentamine and N,N-dimethyl-N′-poly(propylene)-1,3-propylenediamine.
The number-average molecular weight of such polyalkene-substituted amines is about 500 to about 5000, for example 1000 to about 1500 or about 500 to about 3000.
Any of the abovementioned polyalkene-substituted amines which are secondary or primary amines can be alkylated to tertiary amines with alkylating agents which are also known as quaternizing agents, such as dialkyl sulfates, alkyl halides, hydrocarbyl-substituted carbonates; hydrocarbyl epoxides in combination with an acid and mixtures thereof. If particular quaternizing agents, such as alkyl halides or dialkyl sulfates, are used, it may be necessary to provide a base or basic compositions, such as sodium carbonate or sodium hydroxide, to give the free tertiary amine form. Primary amines require two equivalents of alkylating agent and two equivalents of base to obtain a tertiary amine. In another embodiment, the alkylation of primary amines can frequently be conducted in four successive steps, first a treatment with the alkylating agent, followed by a second treatment with a base and then repetition of the two steps. In another embodiment, the alkylation of a primary amine will be effected in one step, for example using two moles of alkyl halide in the presence of an excess of heterogeneous base, such as sodium carbonate. The polyamine can be exhaustively or partially alkylated in a manner known per se.
In another embodiment, the alkylation of primary amines and secondary amines to tertiary amines can be effected with epoxides. Unlike the use of the alkyl halides, no treatment with base is required in the case of use of an epoxide to obtain the free amine. Typically, in the case of alkylation of amines with epoxides, at least one mole of epoxide is used for each hydrogen atom in the amine. In the alkylation to give the tertiary amine with an epoxide, neither additional acid nor base is required.
Particular preference is additionally given to polyisobutenedimethylamine obtainable by hydroformylating polyisobutene (Mn 1000) and subsequent reductive amination with dimethylamine; see Example B of WO 2008/060888.
Compounds of this kind are described, for example, in the applicant's WO2013/000997, which is hereby explicitly incorporated by reference.
Suitable hydrocarbyl-substituted polycarboxylic acid compounds, or hydrocarbyl-substituted acylating agents, include:
The polycarboxylic acid compounds used are aliphatic di- or polybasic (for example tri- or tetrabasic), especially from di-, tri- or tetracarboxylic acids and analogs thereof, such as anhydrides or lower alkyl esters (partially or completely esterified), and is optionally substituted by one or more (for example 2 or 3), especially a long-chain alkyl radical and/or a high molecular weight hydrocarbyl radical, especially a polyalkylene radical. Examples are C3-C10 polycarboxylic acids, such as the dicarboxylic acids malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, and the branched analogs thereof; and the tricarboxylic acid citric acid; and anhydrides or lower alkyl esters thereof. The polycarboxylic acid compounds can also be obtained from the corresponding monounsaturated acids and addition of at least one long-chain alkyl radical and/or high molecular weight hydrocarbyl radical. Examples of suitable monounsaturated acids are fumaric acid, maleic acid, itaconic acid.
The hydrophobic “long-chain” or “high molecular weight” hydrocarbyl radical which ensures sufficient solubility of the quaternized product in the fuel has a number-average molecular weight (Mn) of 85 to 20 000, for example 113 to 10 000, or 200 to 10 000 or 350 to 5000, for example 350 to 3000, 500 to 2500, 700 to 2500, or 800 to 1500. Typical hydrophobic hydrocarbyl radicals include polypropenyl, polybutenyl and polyisobutenyl radicals, for example with a number-average molecular weight Mn of 3500 to 5000, 350 to 3000, 500 to 2500, 700 to 2500 and 800 to 1500.
Suitable hydrocarbyl-substituted compounds are described, for example, in DE 43 19 672 and WO 2008/138838.
Suitable hydrocarbyl-substituted polycarboxylic acid compounds also comprise polymeric, especially dimeric, forms of such hydrocarbyl-substituted polycarboxylic acid compounds. Dimeric forms comprise, for example, two acid anhydride groups which can be reacted independently with the quaternizable nitrogen compound in the preparation process according to the invention.
The quaternizable nitrogen compounds reactive with the above polycarboxylic acid compound are selected from
The quaternizable nitrogen compounds are especially selected from
Examples of suitable “hydroxyalkyl-substituted mono- or polyamines” are those provided with at least one hydroxyalkyl substituted, for example 1, 2, 3, 4, 5 or 6 hydroxyalkyl substituted.
Examples of “hydroxyalkyl-substituted monoamines” include: N-hydroxyalkylmonoamines, N,N-dihydroxyalkylmonoamines and N,N,N-trihydroxyalkylmonoamines, where the hydroxyalkyl groups are the same or different and are also as defined above. Hydroxyalkyl is especially 2-hydroxyethyl, 3-hydroxypropyl or 4-hydroxybutyl.
For example, the following “hydroxyalkyl-substituted polyamines” and especially “hydroxyalkyl-substituted diamines” may be mentioned: N-hydroxyalkylalkylenediamines, N,N-dihydroxyalkylalkylenediamines, where the hydroxyalkyl groups are the same or different and are also as defined above. Hydroxyalkyl is especially 2-hydroxyethyl, 3-hydroxypropyl or 4-hydroxybutyl; alkylene is especially ethylene, propylene or butylene.
Suitable “diamines” are alkylenediamines, and the N-alkyl-substituted analogs thereof, such as N-monoalkylated alkylenediamines and the N,N- or N,N′-dialkylated alkylenediamines. Alkylene is especially straight-chain or branched C1-7- or C1-4-alkylene as defined above. Alkyl is especially C1-4-alkyl as defined above. Examples are especially ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butylenediamine and isomers thereof, pentanediamine and isomers thereof, hexanediamine and isomers thereof, heptanediamine and isomers thereof, and singly or multiply, for example singly or doubly, C1-C4-alkylated, for example methylated, derivatives of the aforementioned diamine compounds such as 3-dimethylamino-1-propylamine (DMAPA), N,N-diethylaminopropylamine and N,N-dimethylaminoethylamine.
Suitable straight-chain “polyamines” are, for example, dialkylenetriamine, trialkylenetetramine, tetraalkyenepentamine, pentaalkylenehexamine, and the N-alkyl-substituted analogs thereof, such as N-monoalkylated and the N,N- or N,N′-dialkylated alkylenepolyamines. Alkylene is especially straight-chain or branched C1-7 or C1-4-alkylene as defined above. Alkyl is especially C1-4-alkyl as defined above.
Examples are especially diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, pentapropylenehexamine, dibutylenetriamine, tributylenetetramine, tetrabutylenepentamine, pentabutylenehexamine; and the N,N-dialkyl derivatives thereof, especially the N,N-di-C1-4-alkyl derivatives thereof. Examples include: N,N-dimethyldimethylenetriamine, N,N-diethyldimethylenetriamine, N,N-dipropyldimethylenetriamine, N,N-dimethyldiethylene-1,2-triamine, N,N-diethyldiethylene-1,2-triamine, N,N-dipropyldiethylene-1,2-triamine, N,N-dimethyldipropylene-1,3-triamine (i.e. DMAPAPA), N,N-diethyldipropylene-1,3-triamine, N,N-dipropyldipropylene-1,3-triamine, N,N-dimethyldibutylene-1,4-triamine, N,N-diethyldibutylene-1,4-triamine, N,N-dipropyldibutylene-1,4-triamine, N,N-dimethyldipentylene-1,5-triamine, N,N-diethyldipentylene-1,5-triamine, N,N-dipropyldipentylene-1,5-triamine, N,N-dimethyldihexylene-1,6-triamine, N,N-diethyldihexylene-1,6-triamine and N,N-dipropyldihexylene-1,6-triamine.
“Aromatic carbocyclic diamines” having two primary amino groups are the diamino-substituted derivatives of benzene, biphenyl, naphthalene, tetrahydronaphthalene, fluorene, indene and phenanthrene.
“Aromatic or nonaromatic heterocyclic polyamines” having two primary amino groups are the derivatives, substituted by two amino groups, of the following heterocycles:
“Aromatic or nonaromatic heterocycles having one primary and one tertiary amino group” are, for example, the abovementioned N-heterocycles which are aminoalkylated on at least one ring nitrogen atom, and especially bear an amino-C1-4-alkyl group.
“Aromatic or nonaromatic heterocycles having one tertiary amino group and one hydroxyalkyl group” are, for example, the abovementioned N-heterocycles which are hydroxyalkylated on at least one ring nitrogen atom, and especially bear a hydroxy-C1-4-alkyl group.
Particular mention should be made especially of the following groups of individual classes of quaternizable nitrogen compounds:
The hydrocarbyl-substituted polycarboxylic acid compound can be reacted with the quaternizable nitrogen compound under thermally controlled conditions, such that there is essentially no condensation reaction. More particularly, no formation of water of reaction is observed in that case. More particularly, such a reaction is effected at a temperature in the range from 10 to 80° C. especially 20 to 60° C. or 30 to 50° C. The reaction time may be in the range from a few minutes or a few hours, for example about 1 minute up to about 10 hours. The reaction can be effected at pressure at about 0.1 to 2 atm, but especially at about standard pressure. For example, an inert gas atmosphere is appropriate, for example nitrogen.
More particularly, the reaction can also be effected at elevated temperatures which promote condensation, for example in the range from 90 to 100° C. or 100 to 170° C. The reaction time may be in the region of a few minutes or a few hours, for example about 1 minute up to about 10 hours. The reaction can be effected at pressure at about 0.1 to 2 atm, but especially at about standard pressure.
The reactants are initially charged especially in about equimolar amounts; optionally, a small molar excess of the polycarboxylic acid compound, for example a 0.05- to 0.5-fold, for example a 0.1- to 0.3-fold, excess, is desirable. If required, the reactants can be initially charged in a suitable inert organic aliphatic or aromatic solvent or a mixture thereof. Typical examples are, for example, solvents of the Solvesso series, toluene or xylene. The solvent can also serve, for example, to remove water of condensation azeotropically from the reaction mixture. More particularly, however, the reactions are performed without solvent.
The reaction product thus formed can theoretically be purified further, or the solvent can be removed. Usually, however, this is not absolutely necessary, such that the reaction product can be transferred without further purification into the next synthesis step, the quaternization.
Particular mention should be made of the condensation product of polyisobutylenesuccinic anhydride (Glissopal® SA from BASF, prepared from polyisobutene (Mn 1000) and maleic anhydride in a known manner) and N,N-dimethyl-1,3-diaminopropane (CAS 109-55-7), see Preparation example 1 of WO 2013/000997.
In another particular embodiment, the at least one quaternizable tertiary nitrogen atom is quaternized with at least one quaternizing agent selected from epoxides, especially hydrocarbyl epoxides.
where the Rd radicals present therein are the same or different and are each H or a hydrocarbyl radical, where the hydrocarbyl radical has at least 1 to 10 carbon atoms. More particularly, these are aliphatic or aromatic radicals, for example linear or branched C1-10-alkyl radicals, or aromatic radicals, such as phenyl or C1-4-alkylphenyl.
Examples of suitable hydrocarbyl epoxides include aliphatic and aromatic alkylene oxides such as, more particularly, C2-12-alkylene oxides such as ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 2-methyl-1,2-propene oxide (isobutene oxide), 1,2-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene oxide, 3-methyl-1,2-butene oxide, 1,2-hexene oxide, 2,3-hexene oxide, 3,4-hexene oxide, 2-methyl-1,2-pentene oxide, 2-ethyl-1,2-butene oxide, 3-methyl-1,2-pentene oxide, 1,2-decene oxide, 1,2-dodecene oxide or 4-methyl-1,2-pentene oxide; and aromatic-substituted ethylene oxides such as optionally substituted styrene oxide, especially styrene oxide or 4-methylstyrene oxide.
In the case of use of epoxides as quaternizing agents, these are used in the presence of free acids, especially in the presence of free hydrocarbyl-substituted unsaturated, especially saturated, optionally substituted, especially unsubstituted, protic acids such as, more particularly, hydrocarbyl-substituted dicarboxylic acids, especially hydrocarbyl-substituted C3-C26 or C3-C12 dicarboxylic acids, especially unsubstituted saturated C3-C6 dicarboxylic acid.
Suitable dicarboxylic acids here are saturated acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid, or higher molecular weight acids, such as tetra-, hexa- or octadecanedioic acid; substituted acids, such as malic acid, α-ketoglutaric acid, oxaloacetic acid; glutamic acid; aspartic acid; and unsaturated acids, such as maleic acid and fumaric acid; such as, more particularly, malonic acid, succinic acid, glutaric acid, adipic acid and pimelic acid.
Additionally suitable are aromatic dicarboxylic acids, for example phthalic acid.
If required or desired, it is also possible to use hydrocarbyl-substituted dicarboxylic acids in their anhydride form. For the quaternization, the ring opening of the anhydride is then brought about by addition of water.
Further configurations relating to hydrocarbyl-substituted dicarboxylic acids:
The hydrocarbyl-substituted dicarboxylic acids can be prepared by hydrolysis of the corresponding hydrocarbyl-substituted dicarboxylic anhydrides in a manner known in principle, as described, for example, in DE 2443537. The hydrolysis is preferably conducted with stoichiometric amounts of water at temperatures of 50 to 150° C., but it is also possible to use an excess of water. The hydrolysis can be conducted without solvent or in the presence of an inert solvent. Typical examples are, for example, solvents from the Solvesso series, toluene, xylene or straight-chain and branched saturated hydrocarbons such as paraffins or naphthenes. The solvent can be removed after the hydrolysis, but preferably remains, and is used as solvent or cosolvent for the subsequent quaternization.
Preferred hydrocarbyl-substituted dicarboxylic anhydrides are hydrocarbyl-substituted succinic anhydrides, as sold, for example, by Pentagon: n-dodecenylsuccinic anhydride CAS 19780-11-1, n-octadecenylsuccinic anhydride CAS 28777-98-2, i-octadecenylsuccinic anhydride CAS 28777-98-2, i-hexadecenylsuccinic anhydride/i-octadecenylsuccinic anhydride CAS 32072-96-1 & 28777-98-2, n-octenylsuccinic anhydride CAS 26680-54-6, tetrapropenylsuccinic anhydride CAS 26544-38-7.
Additionally preferred is polyisobutenesuccinic anhydride (PIBSA). The preparation of PIBSA from polyisobutene (PIB) and maleic anhydride (MA) is known in principle and leads to a mixture of PIBSA and bismaleated PIBSA (BM PIBSA, please see scheme 1 below), which is generally not purified but processed further as it is. The ratio of the two components to one another can be reported as the bismaleation level (BML). The BML is known in principle (see U.S. Pat. No. 5,883,196) and is determined as described in U.S. Pat. No. 5,883,196.
Especially preferred is PIBSA having a bismaleation level of up to 30%, preferably up to 25% and more preferably up to 20%. In general, the bismaleation level is at least 2%, preferably at least 5% and more preferably at least 10%. Controlled preparation is described, for example, in U.S. Pat. No. 5,883,196. For the preparation, high-reactivity PIB (HR-PIB) having Mn in the range from 500 to 3000, for example 550 to 2500, 800 to 1200 or 900 to 1100 is particularly suitable. Mn is determined by means of GPC as described in U.S. Pat. No. 5,883,196. Particularly preferred PIBSA prepared from HR-PIB (Mn=1000) has hydrolysis numbers of 85-95 mg KOH/g.
A nonlimiting example of a particularly suitable PIBSA is Glissopal® SA F from BASF, prepared from HR-PIB (Mn=1000) having a bismaleation level of 15% and a hydrolysis number of 90 mg KOH/g.
It is also conceivable, albeit less preferable, to react the abovementioned hydrocarbyl-substituted dicarboxylic anhydrides not with water but with an alcohol, preferably a monoalcohol, more preferably an alcohol, or an amine to give the corresponding monoester or monoamide of the hydrocarbyl-substituted dicarboxylic acids. What is important is that one acid function remains in the molecule in the case of such a reaction.
If the quaternization is conducted in the presence of an alcohol, preference is given to using the same alcohol for such a reaction of the hydrocarbyl-substituted dicarboxylic anhydrides as that used as solvent in the quaternization, i.e. preferably 2-ethylhexanol or 2-propylheptanol, or else butyldiglycol, butylglycol, methoxypropoxypropanol or butoxydipropanol.
Such an alcoholysis is preferably conducted with stoichiometric amounts of alcohol or amine at temperatures of 50 to 150° C., but it is also possible to use an excess of alcohol or amine, preferably alcohol. In that case, the latter appropriately remains in the reaction mixture and serves as solvent in the subsequent quaternization.
The quaternization with an epoxide of the formula (4) is based in principle on known processes. If the boiling temperature of one component of the reaction mixture, especially of the epoxide, at standard pressure is above the reaction temperature, the reaction is appropriately conducted in an autoclave.
For example, in an autoclave, a solution of the tertiary amine is admixed with the organic hydrocarbyl-substituted dicarboxylic acid (for example polyisobutenesuccinic acid) in the required, approximately stoichiometric amounts. For every equivalent of quaternizable tertiary nitrogen atom, it is possible to use, for example, 0.1 to 2.0, 0.2 to 1.5 or 0.5 to 1.25 equivalents of dicarboxylic acid. More particularly, however, approximately molar proportions of the dicarboxylic acid are used. This is followed by sufficient purging with N2 and establishment of a suitable supply pressure, and by metered addition of the epoxide (e.g. propylene oxide) in the required stoichiometric amounts at a temperature between 20° C. and 180° C. For every equivalent of quaternizable tertiary nitrogen atom, it is possible to use, for example, 0.1 to 4.0, 0.2 to 3 or 0.5 to 2 equivalents of epoxide. More particularly, however, about 1 to 2 equivalents of epoxide are used in relation to the tertiary amine, in order to fully quaternize the tertiary amine group. More particularly, it is also possible to use a molar excess of alkylene oxide, as a result of which the free carboxyl group of the dicarboxylic acid is partly or fully esterified. Subsequently, over a suitably long period of a few minutes to about 24 hours, for example about 10 h, stirring is continued at a temperature between 20° C. and 180° C. (e.g. 50° C.), the mixture is cooled, for example to about 20 to 50° C. and purged with N2, and the reactor is emptied.
The reaction can be effected at a pressure of about 0.1 to 20 bar, for example 1 to 10 or 1.5 to 5 bar. The reaction can however also be effected under standard pressure. More particularly, an inert gas atmosphere, for example nitrogen, is appropriate.
If required, the reactants can be initially charged for the quaternization in a suitable inert organic aliphatic or aromatic solvent or a mixture thereof. Typical examples are, for example, solvents of the Solvesso series, toluene or xylene, or 2-ethylhexanol, or 2-propylheptanol, or else butyldiglycol, butylglycol, methoxypropoxypropanol, butoxydipropanol or straight-chain and branched saturated hydrocarbons, such as paraffins or naphthenes. However, the quaternization can also be performed in the absence of a solvent.
The quaternization can be conducted in the presence of a protic solvent, optionally also in combination with an aliphatic or aromatic solvent. Suitable protic solvents especially have a dielectric constant (at 20° C.) of greater than 7. The protic solvent may comprise one or more OH groups and may also be water. Suitable solvents may also be alcohols, glycols and glycol ethers. More particularly, suitable protic solvents may be those mentioned in WO 2010132259. Especially suitable solvents are methanol, ethanol, n-propanol, isopropanol, all the isomers of butanol, all the isomers of pentanol, all the isomers of hexanol, 2-ethylhexanol, 2-propylheptanol, and also mixtures of various alcohols. The presence of a protic solvent can have a positive effect on the conversion and reaction rate of the quaternization.
The reaction end product thus formed can theoretically be purified further, or the solvent can be removed. Optionally, excess reagent, for example excess epoxide, can be removed. This can be accomplished, for example, by introducing nitrogen at standard pressure or under reduced pressure. In order to improve the further processability of the products, however, it is also possible to add solvents after the reaction, for example solvents of the Solvesso series, 2-ethylhexanol, or essentially aliphatic solvents. Usually, however, this is not absolutely necessary, and so the reaction product is usable without further purification as an additive, optionally after blending with further additive components (see below).
In a preferred embodiment of the present invention, the quaternized ammonium compounds have a weight loss in a thermogravimetric analysis (TGA) at 350° C. of less than 50% by weight, for example less than 40%, less than 35%, less than 30%, less than 20% or less than 15%, for example down to 0% to 5% of weight loss.
For this purpose, a thermogravimetric analysis (TGA) is conducted in accordance with standard ISO-4154. Specifically, in the test, a run from 50° to 900° C. is conducted at a rate of temperature rise of 20° C. per minute under a nitrogen atmosphere at a flow rate of 60 mL per minute.
The use of the invention relates to the inhibition of corrosion of iron, steel and/or nonferrous metal surfaces.
Among the nonferrous metals, preference is given to copper and alloys thereof.
Particular preference is given to inhibiting the corrosion of steel surfaces.
The reaction products described are added to fuels having the above-specified content of alkali metals and/or alkaline earth metals and/or zinc for the effect as a corrosion inhibitor generally in amounts of 1 to 60 and preferably 4 to 50 ppm by weight, and more preferably from 10 to 40 ppm by weight.
In order to show an effect against deposits on valves and/or antistatic action, the reaction products described are added to the fuels generally in amounts of 10 to 120 and preferably 20 to 100 ppm by weight, and more preferably of 30 to 80 ppm by weight.
Frequently, the reaction products described are used in the form of fuel additive mixtures, together with customary additives:
In the case of diesel fuels, these are primarily customary detergent additives, carrier oils, cold flow improvers, lubricity improvers, corrosion inhibitors other than the reaction products described, demulsifiers, dehazers, antifoams, cetane number improvers, combustion improvers, antioxidants or stabilizers, antistats, metallocenes, metal deactivators, dyes and/or solvents.
In the case of gasoline fuels, these are in particular lubricity improvers (friction modifiers), corrosion inhibitors other than the reaction products described, demulsifiers, dehazers, antifoams, combustion improvers, antioxidants or stabilizers, antistats, metallocenes, metal deactivators, dyes and/or solvents.
Typical examples of suitable coadditives are listed in the following section:
The customary detergent additives are preferably amphiphilic substances which possess at least one hydrophobic hydrocarbon radical with a number-average molecular weight (Ma) of 85 to 20 000 and at least one polar moiety selected from:
The hydrophobic hydrocarbon radical in the above detergent additives, which ensures the adequate solubility in the fuel, has a number-average molecular weight (Mn) of 85 to 20 000, preferably of 113 to 10 000, more preferably of 300 to 5000, even more preferably of 300 to 3000, even more especially preferably of 500 to 2500 and especially of 700 to 2500, in particular of 800 to 1500. Typical hydrophobic hydrocarbon radicals include especially polypropenyl, polybutenyl and polyisobutenyl radicals with a number-average molecular weight Mn of preferably in each case 300 to 5000, more preferably 300 to 3000, even more preferably 500 to 2500, even more especially preferably 700 to 2500 and especially 800 to 1500.
Examples of the above groups of detergent additives include the following:
Additives comprising mono- or polyamino groups (Da) are preferably polyalkenemono- or polyalkenepolyamines based on polypropene or on high-reactivity (i.e. having predominantly terminal double bonds) or conventional (i.e. having predominantly internal double bonds) polybutene or polyisobutene with Mn=300 to 5000, more preferably 500 to 2500 and especially 700 to 2500. Such additives based on high-reactivity potyisobutene, which can be prepared from the polyisobutene which may comprise up to 20% by weight of n-butene units by hydroformylation and reductive amination with ammonia, monoamines or polyamines such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine, are known especially from EP-A 244 616. When polybutene or polyisobutene having predominantly internal double bonds (usually in the β and γ positions) are used as starting materials in the preparation of the additives, a possible preparative route is by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to give the carbonyl or carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. The amines used here for the amination may be, for example, ammonia, monoamines or the abovementioned polyamines. Corresponding additives based on polypropene are described more particularly in WO-A 94/24231.
Further particular additives comprising monoanmino groups (Da) are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization P=5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described more particularly in WO-A 97/03946.
Further particular additives comprising monoamino groups (Da) are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described more particularly in DE-A 196 20 262.
Additives comprising nitro groups (Db), optionally in combination with hydroxyl groups, are preferably reaction products of polyisobutenes having an average degree of polymerization P=5 to 100 or 10 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described more particularly in WO-A 96/03367 and in WO-A 96/03479. These reaction products are generally mixtures of pure nitropolyisobutenes (e.g. α,β-dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (e.g. α-nitro-β-hydroxypolyisobutene).
Additives comprising hydroxyl groups in combination with mono- or polyamino groups (Dc) are especially reaction products of polyisobutene epoxides obtainable from polyisobutene having preferably predominantly terminal double bonds and Mn=300 to 5000, with ammonia or mono- or polyamines, as described more particularly in EP-A 476 485.
Additives comprising carboxyl groups or their alkali metal or alkaline earth metal salts (Dd) are preferably copolymers of C2- to C40-olefins with maleic anhydride which have a total molar mass of 500 to 20 000 and wherein some or all of the carboxyl groups have been converted to the alkali metal or alkaline earth metal salts and any remainder of the carboxyl groups has been reacted with alcohols or amines. Such additives are disclosed more particularly by EP-A 307 815. Such additives serve mainly to prevent valve seat wear and can, as described in WO-A 87/01126, advantageously be used in combination with customary fuel detergents such as poly(iso)buteneamines or polyetheramines.
Additives comprising sulfonic acid groups or their alkali metal or alkaline earth metal salts (De) are preferably alkali metal or alkaline earth metal salts of an alkyl sulfosuccinate, as described more particularly in EP-A 639 632. Such additives serve mainly to prevent valve seat wear and can be used advantageously in combination with customary fuel detergents such as poly(iso)buleneamines or polyetheramines.
Additives comprising polyoxy-C2-C4-alkylene moieties (Df) are preferably polyethers or polyetheramines which are obtainable by reaction of C2- to C60-alkanols, C6- to C30-alkanediols, mono- or di-C2- to C30-alkylamines, C1- to C30-alkylcyclohexanols or C1- to C30-alkylphenols with 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl group or amino group and, in the case of the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines. Such products are described more particularly in EP-A 310 875, EP-A 356 725, EP-A 700 985 and U.S. Pat. No. 4,877,416. In the case of polyethers, such products also have carrier oil properties. Typical examples thereof are tridecanol butoxylates or isotridecanol butoxylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates, and also the corresponding reaction products with ammonia.
Additives comprising carboxylic ester groups (Dg) are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanois or polyols, especially those having a minimum viscosity of 2 mm2/s at 100° C., as described more particularly in DE-A 38 38 918. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids, and particularly suitable ester alcohols or ester polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, of isononanol, of isodecanol and of isotridecanol. Such products also satisfy carrier oil properties.
Additives comprising moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or especially imido groups (Dh) are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and especially the corresponding derivatives of polyisobutenylsuccinic anhydride which are obtainable by reacting conventional or high-reactivity polyisobutene having Mn=preferably 300 to 5000, more preferably 300 to 3000, even more preferably 500 to 2500, even more especially preferably 700 to 2500 and especially 800 to 1500, with maleic anhydride by a thermal route in an ene reaction or via the chlorinated polyisobutene. The moieties having hydroxyl and/or amino and/or amido and/or imido groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of di- or polyamines which, in addition to the amide function, also have free amine groups, succinic acid derivatives having an acid and an amide function, carboximides with monoamines, carboximides with di- or polyamines which, in addition to the imide function, also have free amine groups, or diimides which are formed by the reaction of di- or polyamines with two succinic acid derivatives. Such fuel additives are common knowledge and are described, for example, in documents (1) and (2). They are preferably the reaction products of alkyl- or alkenyl-substituted succinic acids or derivatives thereof with amines and more preferably the reaction products of polyisobutenyl-substituted succinic acids or derivatives thereof with amines. Of particular interest in this context are reaction products with aliphatic polyamines (polyalkyleneimines) such as especially ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, which have an imide structure.
Additives comprising moieties (Di) obtained by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols may originate from conventional or high-reactivity polyisobutene having Mn=300 to 5000. Such “polyisobutene Mannich bases” are described more particularly in EP-A 831 141.
One or more of the detergent additives mentioned can be added to the fuel in such an amount that the dosage rate of these detergent additives is preferably 25 to 2500 ppm by weight, especially 75 to 1500 ppm by weight, in particular 150 to 1000 ppm by weight.
Carrier oils additionally used may be of mineral or synthetic nature. Suitable mineral carrier oils are fractions obtained in crude oil processing, such as brightstock or base oils having viscosities, for example, from the SN 500-2000 class; but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. Likewise useful is a fraction which is obtained in the refining of mineral oil and is known as “hydrocrack oil” (vacuum distillate cut having a boiling range of from about 360 to 500° C., obtainable from natural mineral oil which has been catalytically hydrogenated under high pressure and isomerized and also deparaffinized). Likewise suitable are mixtures of the abovementioned mineral carrier oils.
Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins or polyinternalolefins), (poly)esters, (poly)alkoxylates, polyethers, aliphatic polyether-amines, alkylphenol-started polyethers, alkylphenol-started polyetheramines and carboxylic esters of long-chain alkanols.
Examples of suitable polyolefins are olefin polymers having Mn=400 to 1800, in particular based on polybutene or polyisobutene (hydrogenated or unhydrogenated).
Examples of suitable polyethers or polyetheramines are preferably compounds comprising polyoxy-C2- to C4-alkylene moieties obtainable by reacting C2- to C60-alkanols, C6- to C30-alkanediols, mono- or di-C2- to C30-alkylamines, C1- to C30-alkylcyclohexanols or C- to C30-alkylphenols with 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl group or amino group, and, in the case of the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines. Such products are described more particularly in EP-A 310 875, EP-A 356 725, EP-A 700 985 and U.S. Pat. No. 4,877,416. For example, the polyetheramines used may be poly-C2- to C6-alkylene oxide amines or functional derivatives thereof. Typical examples thereof are tridecanol butoxylates or isotridecanol butoxylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates, and also the corresponding reaction products with ammonia.
Examples of carboxylic esters of long-chain alkanols are more particularly esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, as described more particularly in DE-A 38 38 918. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids; particularly suitable ester alcohols or ester polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, for example di(n- or isotridecyl) phthalate.
Further suitable carrier oil systems are described, for example, in DE-A 38 26 608, DE-A 41 42 241, DE-A 43 09 074, EP-A 452 328 and EP-A 548 617.
Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers having about 5 to 35, preferably about 5 to 30, more preferably 10 to 30 and especially 15 to 30 C3- to C6-alkylene oxide units, for example propylene oxide, n-butylene oxide and isobutylene oxide units, or mixtures thereof, per alcohol molecule. Nonlimiting examples of suitable starter alcohols are long-chain alkanols or phenols substituted by long-chain alkyl in which the long-chain alkyl radical is especially a straight-chain or branched C6- to C18-alkyl radical. Particular examples include tridecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherification products) of monohydric aliphatic C6- to C18-alcohols with C3- to C6-alkylene oxides. Examples of monohydric aliphatic C6-C18-alcohols are hexanol, heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 3-propylheptanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol and the constitutional and positional isomers thereof. The alcohols can be used either in the form of the pure isomers or in the form of technical grade mixtures. A particularly preferred alcohol is tridecanol. Examples of C3- to C6-alkylene oxides are propylene oxide, such as 1,2-propylene oxide, butylene oxide, such as 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Particular preference among these is given to C3- to C4-alkylene oxides, i.e. propylene oxide such as 1,2-propylene oxide and butylene oxide such as 1,2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Especially butylene oxide is used.
Further suitable synthetic carrier oils are alkoxylated alkylphenols, as described in DE-A 10 102 913.
Particular carrier oils are synthetic carrier oils, particular preference being given to the above-described alcohol-started polyethers.
The carrier oil or the mixture of different carrier oils is added to the fuel in an amount of preferably 1 to 1000 ppm by weight, more preferably of 10 to 500 ppm by weight and especially of 20 to 100 ppm by weight.
Suitable cold flow improvers are in principle all organic compounds which are capable of improving the flow performance of middle distillate fuels or diesel fuels under cold conditions. For the intended purpose, they must have sufficient oil solubility. More particularly, useful cold flow improvers for this purpose are the cold flow improvers (middle distillate flow improvers, MDFIs) typically used in the case of middle distillates of fossil origin, i.e. in the case of customary mineral diesel fuels. However, it is also possible to use organic compounds which partly or predominantly have the properties of a wax antisettling additive (WASA) when used in customary diesel fuels. They can also act partly or predominantly as nucleators. It is also possible to use mixtures of organic compounds effective as MDFIs and/or effective as WASAs and/or effective as nucleators.
The cold flow improver is typically selected from
(K1) copolymers of a C2- to C40-olefin with at least one further ethylenically unsaturated monomer;
(K2) comb polymer;
(K3) polyoxyalkylenes;
(K4) polar nitrogen compounds;
(K5) sulfocarboxylic acids or sulfonic acids or derivatives thereof; and
(K6) poly(meth)acrylic esters.
It is possible to use either mixtures of different representatives from one of the particular classes (K1) to (K6) or mixtures of representatives from different classes (K1) to (K6).
Suitable C2- to C40-olefin monomers for the copolymers of class (K1) are, for example, those having 2 to 20 and especially 2 to 10 carbon atoms, and 1 to 3 and preferably 1 or 2 carbon-carbon double bonds, especially having one carbon-carbon double bond. In the latter case, the carbon-carbon double bond may be arranged either terminally (α-olefins) or internally. However, preference is given to α-olefins, particular preference to α-olefins having 2 to 8 carbon atoms, for example propene, 1-butene, 1-pentene, 1-hexene and in particular ethylene.
In the copolymers of class (K1), the at least one further ethylenically unsaturated monomer is preferably selected from alkenyl carboxylates, (meth)acrylic esters and further olefins.
When further olefins are also copolymerized, they are preferably higher in molecular weight than the abovementioned C2- to C40-olefin base monomers. When, for example, the olefin base monomer used is ethylene or propene, suitable further olefins are especially C10- to C40-α-olefins. Further olefins are in most cases only additionally copolymerized when monomers with carboxylic ester functions are also used.
Suitable (meth)acrylic esters are, for example, esters of (meth)acrylic acid with C1- to Ca-alkanols, especially C1- to C10-alkanols, in particular with methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, pentanol, hexanol, heptanol, octanol, 2-ethylhexanol, nonanol and decanol, and structural isomers thereof.
Suitable alkenyl carboxylates are, for example, C2- to C14-alkenyl esters, for example the vinyl and propenyl esters, of carboxylic acids having 2 to 21 carbon atoms, whose hydrocarbyl radical may be linear or branched. Among these, preference is given to the vinyl esters. Among the carboxylic acids with a branched hydrocarbyl radical, preference is given to those whose branch is in the α position to the carboxyl group, and the α-carbon atom is more preferably tertiary, i.e. the carboxylic acid is what is called a neocarboxylic acid. However, the hydrocarbyl radical of the carboxylic acid is preferably linear.
Examples of suitable alkenyl carboxylates are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, preference being given to the vinyl esters. A particularly preferred alkenyl carboxylate is vinyl acetate; typical copolymers of group (K1) resulting therefrom are ethylene-vinyl acetate copolymers (“EVAs”), which are some of the most frequently used.
Ethylene-vinyl acetate copolymers usable particularly advantageously and the preparation thereof are described in WO 99/29748.
Suitable copolymers of class (K1) are also those which comprise two or more different alkenyl carboxylates in copolymerized form, which differ in the alkenyl function and/or in the carboxylic acid group. Likewise suitable are copolymers which, as well as the alkenyl carboxylate(s), comprise at least one olefin and/or at least one (meth)acrylic ester in copolymerized form.
Terpolymers of a C2- to C40-α-olefin, a C1- to C20-alkyl ester of an ethylenically unsaturated monocarboxylic acid having 3 to 15 carbon atoms and a C2- to C14-alkenyl ester of a saturated monocarboxylic acid having 2 to 21 carbon atoms are also suitable as copolymers of class (K1). Terpolymers of this kind are described in WO 2005/054314. A typical terpolymer of this kind is formed from ethylene, 2-ethylhexyl acrylate and vinyl acetate.
The at least one or the further ethylenically unsaturated monomer(s) are copolymerized in the copolymers of class (K1) in an amount of preferably 1 to 50% by weight, especially 10 to 45% by weight and in particular 20 to 40% by weight, based on the overall copolymer. The main proportion in terms of weight of the monomer units in the copolymers of class (K1) therefore originates generally from the C2- to C40 base olefins.
The copolymers of class (K1) preferably have a number-average molecular weight Mn of 1000 to 20 000, more preferably of 1000 to 10 000 and especially of 1000 to 8000.
Typical comb polymers of component (K2) are, for example, obtainable by the copolymerization of maleic anhydride or fumaric acid with another ethylenically unsaturated monomer, for example with an α-olefin or an unsaturated ester, such as vinyl acetate, and subsequent esterification of the anhydride or acid function with an alcohol having at least 10 carbon atoms. Further suitable comb polymers are copolymers of α-olefins and esterified comonomers, for example esterified copolymers of styrene and maleic anhydride or esterified copolymers of styrene and fumaric acid. Suitable comb polymers may also be polyfumarates or polymaleates. Homo- and copolymers of vinyl ethers are also suitable comb polymers. Comb polymers suitable as components of class (K2) are, for example, also those described in WO 2004/035715 and in “Comb-Like Polymers, Structure and Properties”, N. A. Platé and V. P. Shibaev, J. Poly. Sci. Macromolecular Revs. 8, pages 117 to 253 (1974). Mixtures of comb polymers are also suitable.
Polyoxyalkylenes suitable as components of class (K3) are, for example, polyoxyalkylene esters, polyoxyalkylene ethers, mixed polyoxyalkylene ester/ethers and mixtures thereof. These polyoxyalkylene compounds preferably comprise at least one linear alkyl group, preferably at least two linear alkyl groups, each having 10 to 30 carbon atoms and a polyoxyalkylene group having a number-average molecular weight of up to 5000. Such polyoxyalkylene compounds are described, for example, in EP A 061 895 and also in U.S. Pat. No. 4,491,455. Particular polyoxyalkylene compounds are based on polyethylene glycols and polypropylene glycols having a number-average molecular weight of 100 to 5000. Additionally suitable are polyoxyalkylene mono- and diesters of fatty acids having 10 to 30 carbon atoms, such as stearic acid or behenic acid.
Polar nitrogen compounds suitable as components of class (K4) may be either ionic or nonionic and preferably have at least one substituent, especially at least two substituents, in the form of a tertiary nitrogen atom of the general formula >NR7 in which R7 is a Cr to C40-hydrocarbyl radical. The nitrogen substituents may also be quaternized, i.e. be in cationic form. An example of such nitrogen compounds is that of ammonium salts and/or amides which are obtainable by the reaction of at least one amine substituted by at least one hydrocarbyl radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. The amines preferably comprise at least one linear C8- to C40-alkyl radical. Primary amines suitable for preparing the polar nitrogen compounds mentioned are, for example, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine and the higher linear homologs; secondary amines suitable for this purpose are, for example, dioctadecylamine and methylbehenylamine. Also suitable for this purpose are amine mixtures, especially amine mixtures obtainable on the industrial scale, such as fatty amines or hydrogenated tallamines, as described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, “Amines, aliphatic” chapter. Acids suitable for the reaction are, for example, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and succinic acids substituted by long-chain hydrocarbyl radicals.
More particularly, the component of class (K4) is an oil-soluble reaction product of poly(C2- to C20-carboxylic acids) having at least one tertiary amino group with primary or secondary amines. The poly(C2- to -C20-carboxylic acids) which have at least one tertiary amino group and form the basis of this reaction product comprise preferably at least 3 carboxyl groups, especially 3 to 12 and in particular 3 to 5 carboxyl groups. The carboxylic acid units in the polycarboxylic acids have preferably 2 to 10 carbon atoms, and are especially acetic acid units. The carboxylic acid units are suitably bonded to the polycarboxylic acids, usually via one or more carbon and/or nitrogen atoms. They are preferably attached to tertiary nitrogen atoms which, in the case of a plurality of nitrogen atoms, are bonded via hydrocarbon chains.
The component of class (K4) is preferably an oil-soluble reaction product based on poly(C2- to C20-carboxylic acids) which have at least one tertiary amino group and are of the general formula IIa or IIb
in which the variable A is a straight-chain or branched C2- to C6-alkylene group or the moiety of the formula III
and the variable B is a C1- to C19-alkylene group. The compounds of the general formulae IIa and IIb especially have the properties of a WASA.
Moreover, the preferred oil-soluble reaction product of component (K4), especially that of the general formula IIa or IIb, is an amide, an amide-ammonium salt or an ammonium salt in which no, one or more carboxylic acid groups have been converted to amide groups.
Straight-chain or branched C2- to C6-alkylene groups of the variable A are, for example, 1,1-ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1,3-butylene, 1,4-butylene, 2-methyl-1,3-propylene, 1,5-pentylene, 2-methyl-1,4-butylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene (hexamethylene) and especially 1,2-ethylene. The variable A comprises preferably 2 to 4 and especially 2 or 3 carbon atoms.
C1- to C19-alkylene groups of the variable B are, for example, 1,2-ethylene, 1,3-propylene, 1,4-butylene, hexamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, octadecamethylene, nonadecamethylene and especially methylene. The variable B comprises preferably 1 to 10 and especially 1 to 4 carbon atoms.
The primary and secondary amines as a reaction partner for the polycarboxylic acids to form component (K4) are typically monoamines, especially aliphatic monoamines. These primary and secondary amines may be selected from a multitude of amines which bear hydrocarbyl radicals which may optionally be bonded to one another.
These parent amines of the oil-soluble reaction products of component (K4) are usually secondary amines and have the general formula HN(R8)2 in which the two variables R8 are each independently straight-chain or branched C10- to C30-alkyl radicals, especially C14- to C24-alkyl radicals. These relatively long-chain alkyl radicals are preferably straight-chain or only slightly branched. In general, the secondary amines mentioned, with regard to their relatively long-chain alkyl radicals, derive from naturally occurring fatty acids and from derivatives thereof. The two R8 radicals are preferably identical.
The secondary amines mentioned may be bonded to the polycarboxylic acids by means of amide structures or in the form of the ammonium salts; it is also possible for only a portion to be present as amide structures and another portion as ammonium salts. Preferably only few, if any, free acid groups are present. The oil-soluble reaction products of component (K4) are preferably present completely in the form of the amide structures.
Typical examples of such components (K4) are reaction products of nitrilotriacetic acid, of ethylenediaminetetraacetic acid or of propylene-1,2-diaminetetraacetic acid with in each case 0.5 to 1.5 mol per carboxyl group, especially 0.8 to 1.2 mol per carboxyl group, of dioleylamine, dipalmitamine, dicocoamine, distearylamine, dibehenylamine or especially ditalamine. A particularly preferred component (K4) is the reaction product of 1 mol of ethylenediaminetetraacetic acid and 4 mol of hydrogenated ditallamine.
Further typical examples of component (K4) include the N,N-dialkylammonium salts of 2-N′,N′-dialkylamidobenzoates, for example the reaction product of 1 mol of phthalic anhydride and 2 mol of ditallamine, the latter being hydrogenated or unhydrogenated, and the reaction product of 1 mol of an alkenylspirobislactone with 2 mol of a dialkylamine, for example ditallamine and/or tallamine, the latter two being hydrogenated or unhydrogenated.
Further typical structure types for the component of class (K4) are cyclic compounds with tertiary amino groups or condensates of long-chain primary or secondary amines with carboxylic acid-containing polymers, as described in WO 93/18115.
Sulfocarboxylic acids, sulfonic acids or derivatives thereof which are suitable as cold flow improvers of the component of class (K5) are, for example, the oil-soluble carboxamides and carboxytic esters of ortho-sulfobenzoic acid, in which the sulfonic acid function is present as a sulfonate with alkyl-substituted ammonium cations, as described in EP-A 261 957.
Poly(meth)acrylic esters suitable as cold flow improvers of the component of class (K6) are either homo- or copolymers of acrylic and methacrylic esters. Preference is given to copolymers of at least two different (meth)acrylic esters which differ with regard to the esterified alcohol. The copolymer optionally comprises another different olefinically unsaturated monomer in copolymerized form. The weight-average molecular weight of the polymer is preferably 50 000 to 500 000. A particularly preferred polymer is a copolymer of methacrylic acid and methacrylic esters of saturated C14- and C15-alcohols, the acid groups having been neutralized with hydrogenated tallamine. Suitable poly(meth)acrylic esters are described, for example, in WO 00/44857.
The cold flow improver or the mixture of different cold flow improvers is added to the middle distillate fuel or diesel fuel in a total amount of preferably 10 to 5000 ppm by weight, more preferably of 20 to 2000 ppm by weight, even more preferably of 50 to 1000 ppm by weight and especially of 100 to 700 ppm by weight, for example of 200 to 500 ppm by weight.
Suitable lubricity improvers or friction modifiers are based typically on fatty acids or fatty acid esters. Typical examples are tall oil fatty acid, as described, for example, in WO 98/004656, and glyceryl monooleate. The reaction products, described in U.S. Pat. No. 6,743,266 B2, of natural or synthetic oils, for example triglycerides, and alkanolamines are also suitable as such lubricity improvers.
B5) Corrosion Inhibitors Other than the Reaction Product Described
Suitable corrosion inhibitors are, for example, succinic esters, in particular with polyols, fatty acid derivatives, for example oleic esters, oligomerized fatty acids, substituted ethanolamines, and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany), Irgacor L12 (BASF SE) or HiTEC 536 (Ethyl Corporation).
Suitable demulsifiers are, for example, the alkali metal or alkaline earth metal salts of alkyl-substituted phenol- and naphthalenesulfonates and the alkali metal or alkaline earth metal salts of fatty acids, and also neutral compounds such as alcohol alkoxylates, e.g. alcohol ethoxylates, phenol alkoxylates, e.g. tert-butylphenol ethoxylate or tert-pentylphenol ethoxylate, fatty acids, alkylphenols, condensation products of ethylene oxide (EO) and propylene oxide (PO), for example including in the form of EO/PO block copolymers, polyethyleneimines or else polysiloxanes.
Suitable dehazers are, for example, alkoxylated phenol-formaldehyde condensates, for example the products available under the trade names NALCO 7D07 (Nalco) and TOLAD 2683 (Petrolite).
Suitable antifoams are, for example, polyether-modified polysiloxanes, for example the products available under the trade names TEGOPREN 5851 (Goldschmldt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc).
Suitable cetane number improvers are, for example, aliphatic nitrates such as 2-ethyihexyl nitrate and cyclohexyl nitrate and peroxides such as di-tert-butyl peroxide.
Suitable antioxidants are, for example substituted phenols, such as 2,6-di-tert-butylphenol and 6-di-tert-butyl-3-methylphenol, and also phenylenediamines such as N,N′-di-sec-butyl-p-phenylenediamine.
Suitable metal deactivators are, for example, salicylic acid derivatives such as N,N′-disalicylidene-1,2-propanediamine.
Suitable solvents are, for example, nonpolar organic solvents such as aromatic and aliphatic hydrocarbons, for example toluene, xylenes, white spirit and products sold under the trade names SHELLSOL (Royal Dutch/Shell Group) and EXXSOL (ExxonMobil), and also polar organic solvents, for example, alcohols such as 2-ethylhexanol, decanol and isotridecanol. Such solvents are usually added to the diesel fuel together with the aforementioned additives and coadditives, which they are intended to dissolve or dilute for better handling.
The inventive use relates in principle to any fuel, preferably diesel and gasoline fuels.
Middle distillate fuels such as diesel fuels or heating oils are preferably mineral oil raffinates which typically have a boiling range from 100 to 400° C. These are usually distillates having a 95% point up to 360° C. or even higher. These may also be what is called “ultra low sulfur diesel” or “city diesel”, characterized by a 95% point of, for example, not more than 345° C. and a sulfur content of not more than 0.005% by weight or by a 95% point of, for example, 285° C. and a sulfur content of not more than 0.001% by weight. In addition to the mineral middle distillate fuels or diesel fuels obtainable by refining, those obtainable by coal gasification or gas liquefaction [“gas to liquid” (GTL) fuels] or by biomass liquefaction [“biomass to liquid” (BTL) fuels] are also suitable. Also suitable are mixtures of the aforementioned middle distillate fuels or diesel fuels with renewable fuels, such as biodiesel or bioethanol.
The qualities of the heating oils and diesel fuels are laid down in detail, for example, in DIN 51603 and EN 590 (cf. also Ullmann's Encyclopedia of industrial Chemistry, 5th edition, Volume A12, p. 617 ff.).
The inventive use in middle distillate fuels of fossil, vegetable or animal origin, which are essentially hydrocarbon mixtures, also relates to mixtures of such middle distillates with biofuel oils (biodiesel). Such mixtures are encompassed by the term “middle distillate fuel”. They are commercially available and usually comprise the biofuel oils in minor amounts, typically in amounts of 1 to 30% by weight, especially of 3 to 10% by weight, based on the total amount of middle distillate of fossil, vegetable or animal origin and biofuel oil.
Biofuel oils are generally based on fatty acid esters, preferably essentially on alkyl esters of fatty acids which derive from vegetable and/or animal oils and/or fats. Alkyl esters are typically understood to mean lower alkyl esters, especially C1- to C4-alkyl esters, which are obtainable by transesterifying the glycerides which occur in vegetable and/or animal oils and/or fats, especially triglycerides, by means of lower alcohols, for example ethanol or in particular methanol (“FAME”). Typical lower alkyl esters based on vegetable and/or animal oils and/or fats, which find use as a biofuel oil or components thereof, are, for example, sunflower methyl ester, palm oil methyl ester (“PME”), soya oil methyl ester (“SME”) and especially rapeseed oil methyl ester (“RME”).
The middle distillate fuels or diesel fuels are more preferably those having a low sulfur content, i.e. having a sulfur content of less than 0.05% by weight, preferably of less than 0.02% by weight, more particularly of less than 0.005% by weight and especially of less than 0.001% by weight of sulfur.
Useful gasoline fuels include all commercial gasoline fuel compositions. One typical representative which shall be mentioned here is the Eurosuper base fuel to EN 228, which is customary on the market. In addition, gasoline fuel compositions of the specification according to WO 00/47698 are also possible fields of use for the present invention.
The examples which follow are intended to illustrate the present invention without restricting it.
Unless stated otherwise, the mass-average Mw and number-average molecular weight Mn of the polymers were measured by means of gel permeation chromatography (GPC). GPC separation was effected by means of two PLge Mixed B columns (Agilent) in tetrahydrofuran at 35° C. Calibration was effected by means of a narrow-distribution polystyrene standard (from PSS, Germany) having molecular weight 162-50400 Da. Hexylbenzene was used as marker for low molecular weight.
R1 here is long-chain hydrocarbyl: R2, R3 and R4 correspond to Ra, Rb and Rc are as defined above; R5 corresponds to Rd as defined above; and R is H or is a radical produced by esterification with the epoxide, for example —CH2CH(R5)OH.
Polyisobutylenesuocinic anhydride (PIBSA, Glissopal® SA, from BASF):
Prepared from maleic anhydride and polyisobutene 1000 in a known manner. Unless stated otherwise, for the inventive preparation examples, qualities having a bismaleation level of 10% to 20% and hydrolysis numbers in the range of 84-95 mg KOH/g were used. For preparation of polyisobutylenesuccinic acid, polyisobutylenesuccinic anhydride was admixed with the equimolar amount of water according to the hydrolysis number and hydrolyzed at a temperature of 80° C. For example, the conversion of polyisobutylenesuccinic anhydride (hydrolysis number 85.6 mg KOH/g) after a reaction time of 4 h at 80° C. gave a reaction product which had an acid number of 83.9 mg KOH/g. The formation of polyisobutylenesuccinic acid was confirmed by IR spectroscopy (1711 cm−1).
In an analogous manner, tetrapropenylsuccinic anhydride (CAS 26544-38-7) and a mixed i-hexadecenyl/i-octadecenylsuccinic anhydride (CAS 32072-96-1 und 28777-98-2) from Pentagon were hydrolyzed to give the corresponding succinic acid derivatives.
Cocoyldimethylamine: (N,N-dimethyl-N—C12/14-amine, CAS 68439-70-3 and 112-18-5) having a total amine number of 246 mg KOH/g.
N-Methyl-N,N-ditallowamine: Armeen® M2HT from Akzo Nobel, CAS 61788-63-4, having a total amine number of 108 mg KOH/g.
The following were additionally used:
N,N-dimethylhexadecylamine (n-C16H33NMe2, CAS 112-69-6, from Aldrich).
Tridecylamine (branched; isomer mixture, CAS 86089-17-0) from BASF.
N,N-Dimethyl-1,3-diaminopropane (DMAPA, CAS 109-55-7) from BASF.
2-Ethylhexanol and 2-propylheptanol from BASF.
Solvent Naphtha naphthalene depleted (ND): Solvesso™ 150 ND from Exxon Mobil.
A 2 l autoclave is initially charged with a solution of the tertiary amine (1 eq. in accordance with the total amine number) and of the alkylenesuccinic acid derivative (1 eq. in accordance with the acid number) in the stated solvent (2-ethylhexanol, unless stated otherwise). The amount of solvent and the batch size are chosen such that the end product has an active content of 50% and the reactor a fill level of about 70%.
This is followed by purging three times with N2, establishment of a supply pressure of approx. 2 bar of N2 and an increase in the temperature to 50° C. The alkylene oxide stated, propylene oxide unless stated otherwise (2 eq.), is metered in within 1 h. This is followed by stirring at 50° C. for 15 h, cooling to 25° C., purging with N2 and emptying of the reactor. The product is transferred into a 2 L jacketed reactor and excess alkylene oxide is removed by introducing an N2 stream (10 I/h) under reduced pressure (70 mbar) at 50′C for 6 h. 1H NMR (CDCl3) confirms the quaternization (δ=3.3 ppm, singlet. R2N(CH3)2 or R3NCH3).
Following the above synthesis method, the following quaternizations were conducted with propylene oxide:
Remarks relating to preparation examples:
Preparation example 5: Quaternization of triethylamine with dodecene oxide in the presence of tetrapropenylsuccinic acids
Reagents: dodecene oxide (CAS 2855-19-8) from Aldrich, trimethylamine (anhydrous, CAS 75-50-3) from BASF
An N2-inertized 2 l autoclave is initially charged with a solution of trimethylamine (47.2 g, 0.8 mol) and dodecene oxide (147.2 g, 0.8 mol) in 2-ethylhexanol (194.4 g). Subsequently, the temperature is increased to 40° C. A solution of tetrapropenylsuccinic acid (252.8 g, 0.8 mol) in 2-ethylhexanol (252.8 g) is metered in within 1.5 h. Subsequently, the mixture is stirred at 40° C. for a further 15 h. Volatile constituents are removed by introducing an N2 stream at 40° C., then the reactor is emptied. 1H NMR (CDCl3) confirms the quaternization (δ=3.3 ppm, singlet, RN(CH3)3).
Tridecylamine (140.2 g) is initially charged at room temperature and formic acid (166.7 g) is added while stirring within 15 min. The reaction mixture is heated to 45° C. and aqueous formaldehyde solution (37%; 132.7 g) is added dropwise within 25 min, with evolution of CO2. Subsequently, the mixture is stirred at 80° C. for 23 h. After cooling to room temperature, hydrochloric acid (32%; 121.5 g) is added while stirring. The mixture is stirred at room temperature for 3 h and the water is removed on a rotary evaporator under reduced pressure. The product mixture is admixed with 500 ml of water and the amine is released with 50% sodium hydroxide solution. The mixture was extracted twice with methyl tert-butyl ether, the combined organic phases were dried over sodium sulfate and the solvent was removed on a rotary evaporator. The product (143.5 g) showed a total amine number of 228 mg KOH/g with 94% tertiary amine.
According to the general synthesis method, iC13NMe2 (preparation example 14), tetrapropenylsuccinic acid and propylene oxide were converted in 2-propylheptanol rather than 2-ethylhexanol.
Quaternization levels are determined by 1H NM spectroscopy. For this purpose, the appropriate solvent is removed with a Kugelrohr still (60° C., p=10−3 mbar, 3 h). To determine the quaternization level, the alkyl moiety is integrated relative to the signals of the quaternized product RCH2NMe2CH2CH(OH)R′. The quotients of the integrals of the signals of the quaternized product and of the corresponding theoretical values multiplied by 100% give the quaternization level. The values for the different signals are averaged. Residues of solvent (doublet at δ=3.55 ppm for HOCH2CHRR′) are taken into account.
For the thermogravimetry analysis, the appropriate solvent was removed with a Kugelrohr still (60-70° C., p=10−3 mbar, 3 h). The thermogravimetry was measured from 30° C. to 900° C. with a temperature rise of 20° C./min. under a nitrogen atmosphere at a flow rate of 60 mL/min. The following changes in mass (TG) were determined at 350° C.:
The above synthesis examples were used to produce, by mixing with polyisobuteneamine (molar mass 1000), polypropylene glycol as carrier oil and solvent and dehazer, the additive formulations specified in table 1, and these were used in the use examples (compositions in parts by weight).
100 ml of motor oil (Shell Helix®, having a Ca content of 1500 ppm, Mg content of 1100 ppm and Zn content of 1300 ppm) were heated to 70° C. in a beaker and then 1 ml of corrosion inhibitor was added. Should the solution still be clear, a further 1 ml of inhibitor is added. If the solution turns cloudy, the test has been failed (for example
A conductivity test was conducted to DIN 51412:
Haltermann E0 base fuel: 58 ps/m
Formulation 1 (comp.) (894 mg/kg of additive): 70 ps/m
Formulation 2 (894 mg/kg of additive): 83 ps/m
It can be seen that the conductivity can be distinctly raised using the inventive compound from preparation example 7.
The fuel used was standard 95-octane E0 gasoline fuel from Haltermann, which was additized according to table 1 and subjected to a corrosion test according to ASTM D 665 B.
As a comparison, in formulation 3, dimer fatty acid (dimeric oleic acid; CAS: 61788-89-4 as corrosion inhibitor dissolved in Solvent Naphtha) was used.
The assessment was made as follows:
The fuel used was standard Aral DIN 590 diesel fuel, which was tested according to DIN D665B (in modified form) with synthetic seawater.
An engine test was conducted over 60 hours according to CEC F-020-98 (keep-clean mode) with MIRO 95-octane E10 fuel and RL 223 motor oil in a port fuel injector engine (M111E) and the deposits on the intake valves (internal valve deposits, IVD) were determined.
The formulations used are listed in table 2, and the results in tables 3 and 4
It is apparent from table 4 that 40 mg/kg of added inventive substances (formulation 10) are capable of achieving an effect on the intake valves comparable to that in comparative formulation 9 of a combination of 100 mg/kg of detergent (Mannich PIBA) with 10 mg/kg of dimer fatty acid in terms of inhibition of corrosion.
The inventive compounds are thus of comparable efficacy at lower dosage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15176880.1 | Jul 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/066229 | 7/8/2016 | WO | 00 |
