CA1264880A - Viscosity index improver - dispersant additive useful in oil compositions - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Hydrocarbon polymers such as ethylene copo-lymers may be reacted with unsaturated nitrogen-contain-ing monomers or unsaturated carboxylic acids in the pre-sence of a free radical catalyst such as a peroxide or azo free radical initiator and a chain stopping agent, e.g. a mercaptan to inhibit excessive cross-linking and branching. The copolymer grafted directly with the ni-trogen-containing monomers may be utilized as an additive for oil and fuel compositions, particularly lubricating oil compositions as a V.I.-dispersant additive. The polymer reacted with carboxylic acid may be further re-acted with amines, polyols, amino-alcohols, etc. to also form a V.I.-dispersant additive.

Description

Field of the inventiorl The invention relates to polymeric viscosity index (V.I.) improvers - dispersant additives for syn-thetic and petroleum oils, particularly lubricating oils.
These additives comprise a hydrocarbon polymer, for ex-ample a copolymer of ethylene with one or more C3 to C2g alpha-olefins, preferably propylene, or a hydrogenated copolymer of styrene and butadiene or isoprene, etc., which have been grafted either with nitrogen-containing monomers, such as vinyl pyridine, vinyl pyrrolidone, aminomethacrylate, etc. or which have been grafted with an acid moiety, e.g. maleic anhydride, preferably fol-lowed by reaction with an amine,which will usually be a polyarnine. The invention relates to processes for pre-paring the precedir)g products and the use of the productsof these processes ln oil, particularly lubricating and fuel compositions. The processes include the direct reaction of either the nitrogen-containing rnonomer or the unsaturated acid compound with the hydrocarbon polymer per se, preferably in the solid state; that is, in the absence of solvent or diluent, wherein the graFting is carried out using a Free radical generator, e.g. a per-oxide or azo initiator, together with a chain stopping agent, e.g. such as a mercaptan or hydroxyl amine in order to hinder cross-linking and occurrence of oil in-solubility.

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Prior Disclosures Ethylene copolymers, particularly ethylene-propylene copolyrners, are in widespread use as viscosity index (V.I.) improving additives for oil compositions, particularly lubricating oil compositions. A substantial body of prior art exists directed towards further react-ing these ethylene V.I. improvers to form a multi-func-tional V.I. improver. This is a material useful as a V.I. -dispersant oil additive so as to improve not only the V.I. properties of the oil but to also impart dis-persancy so as to suspend sludge that rnay form during the operation or use of the lubricant and to inhibit varnish deposition in engines. Various patents teach grafting ethylene copolymers with maleic anhydride, followed by reaction with an amine, either in an oil as a solvent or in a synthetic solvent such as dichlorobenzene, such as the processes disclosed in U.S. Patents 4,137,185, 4,144,1B1 and 4,0B9,794. Similarly, prior patents, such as U.S. 4,092,255, 4,146,4B9 and 4,170,561, were directed towards grafting the ethylene copolymer directly with a nitrogen compound,such as vinyl pyridines and vinyl pyr-rolidones, usually in a chemical solvent,such as dichlo-robenzene,or in an oil as a solvent.
The use of solvents for carrying out these re-actions involves the expense of subsequently removing thesolvent and redissolving the additive in oil to form an oil concentrate, which is the usual way that such addi-tives are marketed. In addition, many of such solvents, such as chlorinated hydrocarbons which do not chain transfer, are expensive and toxic. The idea of carrying out the reartion directly in an oil eliminated the ne-cessity of removing the solvent and gave an economic benefit. However, subsequent problems have arisen using the oil technique since the grafting reaction results in - 35 not only the ethylene copolymer being grafted but also .:

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various compounds of the oil reacting to form unwanted materials. These unwanted grafted oil materials are not only ineffective as V.I. improvers or as dispersants, but in many cases may cause haze due to the formation of insoluble materials, and are detrimental to engine per-formance. In addition, the reaction with the oil mole-cules uses up valuable reactants.
A third approach was to carry out the forma-tion of the desired V.I.-dispersant additive in the ab-sence of any substantial amount of solvent, either oil orsynthetic solvent, at least in carrying out the grafting reaction. This approach has been suggested by various prior art patents, such as U.S. 4,068,056; 4,068,057 and 4,068,058, wherein amines are directly grafted upon an ethylene-propylene copolymer by mastication or by an extruder, either under a nitrogen atmosphere as in 4,068,057 or in the presence of oxygen as in 4,06a,058 ~nd 4,068,056.
U.S. 3,862,265 has a broad disclosure o~ ex-truder-grafting a wide range of polymers including ethy-lene-propylene elastomers with various monomers, includ-ing maleic anhydride. U.K. Patent 857,797 teaches graft-ing polymers by mastication using peroxide and in the presence of oxygen or air. U.K. 1,119,629 grafts maleic anhydride onto synthetic rubber in an extruder using inhibitors to control cross-linking. U.K. 832,193 has an extensive disclosure whereir- various monomers were graft-ed by mastication upon various polymers using various techniques. The use of chain stopping agents or chain transfer agents have been suggested to inhibit cross-linking, as in U.S. Patent 4,160,072; published Japanese Patent Application JA 53-110453 (Publication No.
55-36274) 1980, and in Japanese Patent Publication No.
46-35370 (1971).

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The use of non-ethylene hydrocarbon polymers to form V.I. dispersant additives is also known in the art, such as those of U.S. Patents 3,903,003; 4,0773893 and U.S. 4,141,B47.
Ihe present invention is a further improvement in forming useful oil soluble additives, wherein the grafting is carried out with the hydrocarbon polymer, preferably a polyolefin,in the form of a solid rubber in the substantial absence of any chemical solvent or lu-bricating oil. This avoids the need to remove the chem-ical solvent and it avoids the grafting of the oil mole-cules during the course of the reaction. The present inven.ion preferably utilizes free radical generators, such as peroxides, in order to speed up the graft reac-tion. However, simply grafting the hydrocarbon polymer,e.g. ethylene copolymer per se,either in an extruder or a masticator with peroxide has been found to result in cross-linking the polymer with the frequent Formation of insoluble gel, or insoluble gel-like portions, when it was attempted to later dissolve the grafted material in oil. On the other hand, attempting to avoid the gelling by restricting the amount of grafting was unsatisfactory since a certain amount of grafting is necessary to in-corporate the desired amount of nitrogen-containing moi-eties to achieve the desired degree of dispersancy. Thus,the present invention differs from the above-noted prior art in utilizing both a free radical generator and a chain stopping agent in carrying out the grafting of a hydrocarbon polymer in the solid state, i.e. in the sub-stantial absence of solvent or diluent, with an unsatu-rated monomer which may either be a nitrogen monomer or an unsaturated acid which can then oe subsequently re-acted with an amine or alcohol, e.g. a polyol, or amino alcohol, in a subsequent reaction to form oil soluble additives.

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DESCRIPTION OF PREFERRED EMBODIMENT
~ydrocarbon Polymer Oil soluble hydrocarbon polymers or copolymers used in the invention generally will have a number aver--age molecular weight (Mn) o-f from about 5000 to about 500,000; preferably 10,000 to 200,000 and optimally from ! about 20,000 to 100,000. In general, polymers useful as V.I. improvers will be used. These V.I. improvers will generally have a narrow range of molecular weight, as de-termined by the ratio of weight average molecular weight (Mw) to numbér average molecular weight (~n). Polymers having a (MW/Mn) of less than 10~ preferably less than 7, and more preferably 4 or less are most desirable. As used herein (Mn) and (~) are measured by the well known techniques of vapor phase osmometry (VPC), membrane os-mometry and gel permeation chromotography. In general, polymers having a narrow range of molecular weight may be obtainecl by a choice of synthesis conditions such as choice of catalyst, or principal catalyst and cocatalyst combination, addition of hydrogen during the synthesis, etc. Post synthesis treatment such as extrusion at ele-vated temperature and under high shear through small orifices, mastication under elevated temperatures, ther-mal degradation, fractional precipitation from solution, etc. may also be used to obtain narrow ranges of desired molecular weights and to break down higher molecular weight polymer to different molecular weight grades for V.I. use.
Examples of suitable hydrocarbon polymer include homopolymers and copolymers of two or more monomers of C2 to C2g, e.g. C2 to C1g olefins, including both alpha olefins and internal olefins, which may be straight or branched, aliphatic, aromatic, alkylaromatic, cycloaliphatic, etc. Frequently they will be of ethylene with C3 to C2g olefins, particularly ~2~

preferred being the copolymers of ethylene and propylene, and polymers of other olefins such as propylene, butene and polyisobutylene. Also homopolymers and copolymers of C6 and higher alpha olefins can be preferably errlployed.
Such hydrocarbon polymers also include olefin polymers such as atactic polypropylene, hydrogenated polymers and copolymers and terpolymers of styrene, e.g.
with isoprene and/or butadiene.
The preferred polymers are prepared from ethy-lene and ethylenically unsaturated hydrocarbons including cyclic, alicyclic and acyclic9 containing from 3 to 28 carbons, e.g. 2 to 1B carbons. These ethylene copolymers may contain from 15 to 9û wt. O ethylene, preferably 30 to 80 wt. ~ of ethylene and 1û to 85 wt. 0~ preferably 20 to 7û wt. O of one or more C3 to C2g9 preferably C3 to C1g, more preferably C3 to Cg, alpha olefins. While not essential, such copolymers preferably have a degree of crystalllnity of less than 25 wt. ~O~ as determir~ed by X-ray and differential scanning calorimetry. Copolymers of ethylene and propylene are most preferred. Other alpha-olefins suitable in place of propylene to form the copolymerg or to be used in combination with ethylene and propylene, to form a terpolymer, tetrapolymer, etc., ; include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-oc-tene, 1-nonene, 1-decene, etc.; also branched chain al-pha-olefins, such as 4-methyl-1-pentene, 4-methyl-1-hex-ene, 5-methylpentene-1, 4,4-dimethyl-1-pentene, and 6-methylheptene-1, etc., and mixtures thereof.
The term copolymer as used herein, unless otherwise indicated, includes terpolymers, tetrapolymers, etc., preferably of ethylene, said C3_2g alpha-olefin and/or a non-conjugated diolefin or mixtures of such diolefins which may also be used. The amount of the non-conjugated diolefin will generally range from about ~z~ 0 0.5 to 20 mole percent, preferably about 1 to about 7 mole percent, based on the total amount of ethylene and alpha-olefin present.
Representative examples of non-conjugated dienes that may be used as the third monomer in the ter-polymer include:
- a. Straight chain acyclic dienes such as:
1,4-hexadiene; 1,5-heptadiene; 1,6-octa-diene.

b. Branched chain acyclic dienes such as:
5-methyl-1,4-hexadiene; 3,7-dimethyl 1,6-octadiene; 3,7-dimethyl 1,7-octadiene;
and the mixed isomers of dihydro-myrcene and dihydro-cymene.

c. Single ring alicyclic dienes such as:
1,4-cyclohexadiene; 1,5-cyclooctadiene;
1,5-cyclo-dodecadiene; 4-vinylcyclohex-ene; 1-allyl, 4-isopropylidene cyclohex-ane; 3-allyl-cyclopentene; 4-allyl cyclo-hexene and 1-isopropenyl-4-(4-butenyl) cyclohexane.

d. Multi-single ring alicyclic dienes such as: 4,4'-dicyclopentenyl and 4,4'-di-cyclohexenyl dienes.

- 25 e. Multi-ring alicyclic fused and bridged ring dienes such as: tetrahydroindene;
methyl tetrahydroindene; dicyclopenta-diene; bicyclo (2.2.1) hepta 2,5-diene;
alkyl, alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as:

ethyl norbornene; 5-methylene-6-methyl-2-norbornene, 5-rnethylene-6, 6-dimethyl-

2-norbornene; 5-propenyl-2-norbornene;
5-(3-cyclopentenyl)-2-norbornene and 5-cyclohexylidene-2-norbornene; norborna-diene; etc.
Other suitable hydrocarbon polymers may be made from styrene, and substituted styrenes, such as alkylated styrene, or halogenated styrene. The alkyl group in the alkylated styrene, which may be a substitu-ent on the aromatic ring or on an alpha carbon atom, may contain from 1 to about 20 carbons, preferably 1-6 carbon atoms. These styrene type monomers may be copolymerized with suitable conjugated diene monomers including buta-lS diene and alkyl-substituted butadiene, etc., having from 1 to about 6 carbons in the alkyl substituent. Thus, in addition to butadiene, isoprene, piperylene and 2,3-di-methylbutadiene are useful as the diene monomer. Two or more different styrene type monomers as well as two or more different conjugated diene monomers may be polymer-ized to form the interpolymers. Still other useful po-lymers are derived without styrene and only from alipha-tic conjugated dienes, usually having from 4 to 6 carbon atoms most usefully, butadiene. Examples are homopoly-mers of 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-dimethylbutadien~s, copolyrners formed with at least two of these conjugated dienes and copolymers of the latter with styrene, these homopolymers and copolymers having been hydrogenated. These aforesaid polymers with considerable unsaturation are preferably fully hydrogenated to remove substantially all of the olefinic unsaturation, although, in some situations, partial hydrogenation of the aromat-ic-type unsaturation is effected. These interpolymers are prepared by conventional polymerization techniques ~LZi~8~3~

involving the formation of interpolymers having a con-trolled type of steric arrangement of the polymerized monomers, i.e. random, block, tapered, etc. Hydrogena-tion of the interpolymer is effected using conventional 5 hydrogenation processes.
Polyisobutylenes are readily obtained in a - known manner as by following the procedure of U.S. Pat.
No. 2~084~501 wherein the isoolefin, e.g. isobutylene, is polymerized in the presence of a suitable Friedel-Crafts 10 catalyst, e.g. boron fluoride, aluminum chloride, etc., at temperatures substantially below 0CO such as at -40C. Such isobutylenes can also be copolymerized with a higher straight chained alpha-olefin of 6 to 20 carbon atoms as taught in U.S. Pat. No. 2~534~095 where said 15 copolymsr contains from about 75 to about 9~6 by volume oF isobutylene and about 1 to about 25o by volumt-~ of a higher normal alpha-olefin of 6 to 20 carbon atoms. Co-polymers of isobutylerle with dienes such as isoprene or piperylene may also be used.
20 Ethylenically Unsaturated Carboxylic Acid Material These materials which are grafted onto the hydrocarbon polymer contain 3 to 10 carbon atoms and at least one ethylenic unsaturation and at least one, pre-ferably two, carboxylic acid groups, or an anhydride 25 group, or a polar group which is convertible into said carboxyl groups by oxidation or hydrolysis. Maleic an-hydride or a derivative thereof is preferred as it does not appear to homopolymerize appreciably but attaches onto the polymer to give two carboxylic acid functiorl-30 alities. Such preferred materials have the generic form-ula O C C O
~ 0~

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wherein R1 and R2 are hydrogen or a halogen. Suitable examples additionally include chloro-maleic anhydride, itaconic anhydride, hemic anhydride or the corresponding dicarboxylic acids, such as maleic acid or fumaric acid or their monoesters, etc.
As taught by U.S. 4,160,739 and U.S. 4,161,452, various unsaturated comonomers may be grafted on the olefin copolymer together with the unsaturated acid com-ponent, e.g. maleic anhydride. Such graft monomer sys-tems may comprise one or a mixture of comonomers differ-ent from the unsaturated acid component and which contain only one copo~ymerizable double bond and are copolymeriz-able with said unsaturated acid component. Typically, such comonomers do not contain free carboxylic acid groups and are esters containing c~,~ -ethylenic unsatu-ration in the acid or alcohol portion; hydrocarbons, both aliphatic and aromatic, containing~ ethylenic unsatu-ration, such as the C4-C12 alpha olefins, for example isobutylene, hexene, nonene, dodecene, etc.; styrenes, for example styrene, ~ -methyl styrene, p-methyl styrene, p-sec. butyl styrene, etc.; and vinyl monomers, for ex-ample vinyl acetate, vinyl chloride, vinyl ketones such as methyl and ethyl vinyl ketone, etc. Comonomers con-taining functional groups which may cause crosslinking, gelation or other interfering reactions should be avoid-ed, although minor amounts of such comonomers (up to about 10~ by weight of the comonomer system) often can be tolerated.
Unsaturated Nitrogen Containing Monomer Nitrogen containing unsaturated compounds are well known in forming polymers useful as oil additives These monomers may be used for grafting onto the polymer and include, among others those having 6 to 30 carbon - atoms and 1 to 4 nitrogen atoms.

Nitrogen containing acrylate and methacrylate monomers may be used such as dimethylaminoethyl methacry-late or acrylate; acrylamides and methacrylamides such as N-(1,1-dimethyl-3-oxobutyl)acrylamide, N-(1,2-dimethyl-5 1-ethyl-3-oxobutyl)acrylamide, N-(1,3-diphenyl-1-methyl-

3-oxoproyl)acrylamide, N-(1-methyl-1-phenyl-3-oxobutyl) methacrylamide, N,N-diethylaminoethyl acrylamide, 2-hydroxyethyl acrylamide, N-dimethylaminopropyl acrylamide and methacrylamide.
N-vinylcaprolactams may be used. These in-clude N-vinylpyrrolidone, N-vinylthiopyrrolidone, 3-methyl-1-vinylpyrrolidone, 4-methyl-1-vinylpyrrolidone, 5-methyl-1-vinylpyrrolidone, 3-ethyl-1-vinylpyrrolidone, 3-butyl-1-vinvlpyrrolidone, 3,3-dimethyl-1-vinylpyrroli-lS done, 4,5-dimethyl-1-vinylpyrrolidone, etc.
Vinyl pyridines may be used, such as 2 vinyl-pyridine, 4-vinylpyridine, and lower alkyl (C1-Cg) sub-stituted C-vinylpyridines, such as 2-methyl-5-vinylpyri-dine, 2-methyl-4-vinylpyridine, 2-vinyl-5-ethyl pyridine, 20 2-vinyl-6-methylpyridine, etc.
Grafting of the Polymer The grafting of the polymer with the carboxyl-ic acid material or nitrogen monomer may be carried out in an extruder, a rubber mill, a Banbury mixer, Brabender 25 mixers, and other mechanical mixing devices which can mix or knead the rubber at elevated temperatures with the other components of the reaction into a homogeneous solid rubbery mass so grafting can take place in the solid state. Combinations of equipment may also be used, such 30 as a low temperature mixer for premixing the ingredients, following which they can be transferred to a high tem-perature heated mixer for grafting.

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The rsdical grafting is preferably carried out using free radical initiators such as peroxides, hydro-peroxides, and azo compounds and preferably those which have a boiling point greater than about 100C. and which 5 decompose thermally within the grafting temperature range to provide said free radicals. Representative of these free-radical initiators are azobutyro-nitrile, di-lauroyl peroxide, 2,5-di-methyl-hex-}-yne-2, 5 bis-tertiary-butyl peroxide ~sold as Lupersol 130) or its hexane analogue, lO di-tertiary butyl peroxide and dicumyl peroxide. The initiator is generally used at a level of bet~een about 0.005~6 and about 1o~ e.g. 0.05 to 0.5O~ based on the total weight of the ethylene copolymer, and temperatures of about 120 to 250C.
The~ ethylenically unsaturated nitrogen monomer or carboxylic acid material, preferably maleic anhydride, will be generally used in an amount ranging from about 0.1 to about 10o~ preferably 0.5 to 5.06, based on weight of the initlal ethylene copolymer. The aforesaid car-20 boxylic acid or nitrogen monomer material and free radi-cal initiator are generally used in a weight percent ratio range of 1.û:1 to 30:1, preferably 4.0:1 to 12:1.
The chain stopping agent is preferably an ali-phatic mercaptan having 4 to 24 carbon atoms, such as 25 t-butyl mercaptan, n-butyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, etc. The ter-tiary mercsptans and diethyl hydroxyl amine are particu-larly effective and are the most preferred. Other chain stopping agents may be used, for example, cumene, alco-30 hols, phenols, etc. The chain stopper will be generallyused in an amount of 0.05 to 10 wt. O~ e.g. 0.1 to 5 wt.
O~ based on the weight of the ethylene copolymerO

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The initiator grafting is preferably carried out at 12û-250C., preferably 150-220C. An inert atmosphere, such as that obtained by nitrogen blanketing can be used. While the grafting can be carried out in the presence of air, the yield of the desired graft poly-mer is generally thereby decrcased as compared to graft-ing under an inert atmosphere substantially free of oxy-gen. The total time will usually range from about 0.005 to 12 hours. If carried out in an extruder, the total time will be relatively short, e.g. 0.005 to 0.2 hours.
In a masticator usually from about 0.5 to 6 hours, more preferably û.5 to 3 hours,total time will be required.
The graft reaotion will be usually carried out to at least approximately 4 times, preferably at least about 6 times,the half-life of the free-radical initiator at the reaction temperature employed, e.g. with 2,5-dimethyl hex-3-yne-2~S-bis(t-butyl peroxide) 2 hours at 160C.
and one hour at 170C., etc.
In the grafting process, usually the polymer rubber is first heated to about 100-160C. and below the grafting temperature to facilitate mixing with the other ingredients, such as the unsaturated graft material, e.g.
maleic anhydride, chain s~topper and initiator~ all of which are added with mixing to form a homogeneous mix-ture. The chain stopper is preferably added before theinitiator. The reaction mixture can then be further heated to grafting temperatures, preferably in the range of about 170 to 240C. Grafting temperature is the - temperature where the initiator breaks down to form free radicals and cause substantial grafting to take place.
When the reaction is complete, the excess monorner materi-al may be eliminated by an inert gas purge, e.g. nitrogen sparging. Continuous or periodic addition of the graft material to the reactor can be utilized along with an appropriate portion of initiator and chain stopper during ~L26~8~C) the course of the reaction.
In some cases the grafting can take place in several stages by mixing the reactants together below the grafting temperature; heating to a higher temperature to graft; cooling below grafting temperatu~e; adding and mixing more unsaturated material, initiator and chain stopper; heating again to the grafting temperature to graft the added material, etc. In still other cases, it may be desirable to heat the polymer to grafting tempPra-ture and add the chain stopper, the unsaturated acid ornitrogen monomer and the initiator all while at graftlng temperatures. Alternatively~ the chain stopper can be added to the polymer below grafting temperature, and the initiator and unsaturated acid or nitrogen monomer can be added at grafting temperatures.
After the grafting is complete, diluent oil, such as mineral lubricating oil, may be mixed into the grafted ethylene copolymer to form a concentrate. This dllution can be carried out in a masticator used For the grafting, or dilution can be carried out in a separate heating and mixing vessel. The oil solution can be the final additive product if the grafting used a N-contain-ing monomer. ûn the other hand, if unsaturated acid or anhydride, such as maleic anhydride,was grafted on the polymer, then a further reaction with an arnine or hydroxy component is carried out to form a V.I.-dispersant addi-tive. This will usually be carried out using the diluted grafted polymer in a separate reaction vessel from t~at used For grafting.
The Amine Component Useful amine compounds for neutralization of the acid, e.g. maleic anhydride, grafted polymer include mono- and polyamines of about 2 to 6û, e.g. 3 to 2û, total carbon atoms and about 1 to 12, e.g. 7 2 to 7 ni-trogen atoms in the molecule. These amines may be hy-~Z6~

drocarbyl amines or may be hydrocarbyl amines includingother groups, e.g., hydroxy groups, alkoxy groups, amide groups, imidazoline groups~ and the like. Hydroxy amines with 1 to 6 hydroxy groups, preferably 1 to 3 hydroxy groups are particularly useful. Preferred amines are aliphatic saturated amines, including those of the gene-ral formulas:

R- N- R'tand R- IN- (CH2)s- ~ - N- (CH2)sl N- R
R" R' H R' _ _ t .

wherein R, R' and R7' are independently selected from the group consisting of hydrogen; C1 to C2s straight or branched chain alkyl radicals; C1 to C12 alkoxy C2 to C6 alkylene radicals; C2 to C12 hydroxy amino alkylene radicals; and C1 to C12 alkylamino C2 to C6 alkylene rad-icals; s is a number oF From 2 to 6, preferably 2 to ~I;
and t is a nùrnher of from 0 to 10, preferably 2 to 6.
~ xamples o~ suitahle amine com-pounds include: 1,2-diaminoethane; 1,3-diaminopropane;
1,4-diaminobutane; 1,6-diaminohexane; polyethylene amines such as diethylene triamine; triethylene tetramine; te-traethylene pentamine; polypropylene amines such as 1,2-propylene diamine; di-(1,2-propylene)triamine; di-(1,3-propylene)triamine; N,N-dimethyl-1,3-diaminopropane;
N,N-di-(2-aminoethyl)ethylene diamine; N,N-di(2-hydroxy-ethyl)-1,3-propylene diamine; 3-dodecyloxypropylamine;
N-dodecyl-1,3-propane diamine; tris-hydroxymethylamino-methane (THAM); diisopropanol amine; diethanol amine;
triethanol amine; mono-, di-, and tri-tallow amines;
N-amino alkyl morpholines where the alkyl is 0 to 5 car-bons such as N-(2-aminoethyl) morpholine; N-(3-amino-propyl)morpholine; substituted pyridines such as 2-amino pyridine; 2-methylamino pyridine; and 3-methylamino pyri-- dine; 2-(2-aminoethyl) pyridlne; 2-(4-aminoethyl) pyri-dine; and other amines including 2-amino pyrimidine;
2-amino benzothiazole; 2-aminothiazole; 2-amino-2-thiazo-5 line; methyl-1-phenyl hydrazine; isopropyl ethylene di-amine; and para-morpholino aniline; etc.
Other useful amine compounds include: alicy-clic diamines such as 1,4-di(aminomethyl) cyclohexane, and heterocyclic nitrogen compounds such as imidazolines, lO and N-aminoalkyl piperazines of the general formula:

NH2- (CH2)p - N N - G

wherein G is independently selected from the group con-lS sisting of hydrogen and omega-aminoalkylene radicals of from 1 to 3 carbon atoms, and p is an integer of from O
to 4, e.g. 1 to 4. Non-limiting examples of such amines include 2-pentadecyl imidazoline; N-(2 aminoethyl) pi-perazine; etc.
Commercial mixtures of amine compounds may ad-vantageously be used. For example, one process for pre-paring alkylene amines involves the reaction of an alky-lene dihalide (such as ethylene dichloride or propylene dichloride) with ammonia, which results in a complex 25 mixture of alkylene amines wherein pairs of nitrogens are joined by alkylene groups, forming such compounds as diethylene triamine, triethylenetetramine, tetraethylene pentamine, pentaethylene hexamine, and isomeric pipera-2ines. Low cost poly(ethyleneamines) compounds having a , ~L2G4~

composition approximating tetraethylene pentamine are available commercially under the trade ~e "Polyamine H"
and "Polyamine ~00" (PA-400).
Especially preferred are amines having a S single primary amine group, with any other amine groups present being tertiary amine groups. This minimizes cross-linking and becomes particularly important when the polymer has a relatively high degree of acidity, e.g.
above 0.1 meq./g. of polymer. MixturPs comprlsing about 70 wt. OD or more of amines having only a single primary or secondary group may be used with small amounts of amines having two or more primary or secondary amine groups. Acidities below 0.1 meq./g. polymer are less sensitive to cross-linking and amines with 2 or more reactive groups, i.e. either primary or secondary amine groups, or bol:h primary and secondary amine groups, or a primary amine group and an alcohol group, rnay be used.
The Alcohol Component The V.I.-ashless dispersants may be esters de-rived from the aforesaid polymer grafted with carboxylic acid or anhydride and from hydroxy compounds such as monohydric and polyhydric alcohols or aromatic compounds such as phenols and naphthols etc. The polyhydric alco-hols are the most preferred hydroxy compound and prefera-bly contain from 2 to about 10 hydroxy radicals, forexample, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and other alkylene glycols in which the alkylene radical contains from 2 to about 8 carbon atoms. Other useful polyhydric alcohols include glycerol, mono-oleate of glycerol, monostearate of glycerol, monomethyl ether of glycerol, pentaerythritol, dipentaerythritol, etc.

The ester dispersant may also be derived from - unsaturated alcohols such as allyl alcohol9 cinnamyl alcohol, propargyl alcohol, 1-cyclohexane-3-ol, and oleyl alcohol. Still other classes of the alcohols capable of 5 yielding the esters of this invention comprise the ether-alcohols and amino-alcohols including, for example, the oxy-alkylene, oxy-arylene , amino-alky:Lene-, and amino-arylene-substituted alcohols having one or more oxy-alky-lene, amino-alkylene, amino-arylene or oxy-arylene radi-10 cals. They are exemplified by Cellosolve, Carbitol,N,N,N',rJ'-tetrahydroxy-trimethylene di-amine, and the likeO For the most part, the ether-alcohols having up to about 150 oxy-alkylene radicals in which the alkylene radical contains from 1 to about 8 carbon atoms are pre-15 ferred.
Especially preferred are monoalcohols when theacidity is above 0.1 meq./g. of polymer, while polyols may be used at acidities below 0.1 meq./g. of polymer.
Preferred V.I.-ester dispersant additives are di-esters 20 of succinic anhydride moieties formed by grafting ethy-lene copolymer with maleic anhydride.
Reaction of Crafted Polymer with Amine or Alcohol Components The polymer, grafted with acidic moieties, pre-ferably in solution generally equal to about 5 to 30 wt.O~ preferably 10 to 20 wt. O polymer, can be readily reacted with amines or alcohols by heating at a tempera-ture of from about 100C. to 250C., preferably from 120 to 23ûC., for from about 0.5 to 10 hours, usually about 1 to about 6 hours. The heating is preferably carried out to favor formation of imides, and amides in the case of amine components, or esters in the case of alcohol components. Reaction ratios can vary considerably, de-pending upon the reactants, amounts of excess~ type of bonds formed, etc.

~ ~z~ o Compositions A minor amount, e.g~ 0.001 up to 5û wt. O~ pre-ferably 0.005 to 25 wt. ~09 based on the weight of the total composition, of the oil-soluble graft polymers 5 produced in accordance with this invention can be incor-porated into a major amount of an oleaginous material, such as a lubricating oil or hydrocarbon fuel, depending upon whether one is forming finished products or additive concentrates. When used in lubricating oil compositionsl lO e.g., automotive or diesel crankcase lubricating oil9 the final grafted polymer V.I.-dispersant concentrations are usually within the range of about 0.01 to 1û w-t. Do~ e.g.9 0.1 to 6.0 wt~ O~ preferably 0.25 to 3.û wt. ~O~ of the total composition. The lubricating oils to which the 15 products of this invention ean be added include not only hydrocarbon oil derived from petroleum, but also include synthetic lubrlcatirlg oils such as esters o~` dicarboxylic acids; complex esters made by esterification of monocar-boxylic acids, polyglycols, dicarboxylic acids and alco-20 hols; polyolefin oils, etc.
The V.I.-dispersant graft polymers of the in-vention may be utilized in a concentrate form9 e.g., from about 5 wt.Uo up to about 50 wt. ~, preferably 7 to 25 wt.
0, in oil, e.g., mineral lubricating oil, for ease of 25 handling.
The above oil compositions may contain other conventional additives, such as dyes, pour point depres-sants, antiwear agents, antioxidants, other viscosity-index improvers, dispersants, etc.
The following examples, wherein all parts are parts by weight, which include preferred embodiments9 further illustrate the present invention.

, ~ Z6~

-1816 9. of ethylene-propylene solid rubber were added through a hatch in the top of a 9.5 liter laboratory masticator, which was then closed, and heated to 140C. while mixing under a nitrogen stream for about 45 minutes. This mixing caused the rubber to band, that is form a sticky cohesive mass around the masticator mixer b~ades. Then, 65 9. of tert. dodecyl mercaptan as chain stopper were added over about 5 minutes, followed by the addition of 62 9. of maleic anhydride over another 5 minutes. Next, 7.3 9. of Lupersol 130 dissolved in 7.3 9. of polyiso~)utylene of 50û ~n mol. wt. for ease of handling were added over another 5 minutes. Mixing under nitrogen at 140C. continued during all of said aclcliti-ons.
The temperature was then raised over about 15minutes to 190C., where the Lupersol rapidly breaks down and the major proportion of the grafting takes place. The masticator contents were then heat soaked at 190C. for 20 minutes, followed by nitrogen stripping at 1.25 hours at 190C. to remove unreacted maleic anhydride and other volatiles. Then 4540 9. of S100NLP (Solvent Neutral lu-bricating oil of 10û SUS viscosity at 37.8C, low pour) were added over a period of 1.75 hours at 190C. The temperature was then dropped to 160C. for 30 minutes, after which the masticator was drained to give the Prod-uct of Example 1. All of the preceding was carried out while mixing under a nitrogen atmosphere. The Product of Example 1 was a clear, viscous oil solution of the maleic anhydride grafted rubber. The grafted polymer in this Product analyzed 0.149 milliequivalents of acid per 9. of polymer, which indicated that about 43~ of the maleic an-hydride charged to the masticator had reacted.

The laboratory masticator used above was a Beken Duplex Mixer manufactured by the Bramley Machinery Corp., Edgewater, N.J. It had a 2-1/2 gal. reactor space heated by a Dow Therm containing outer jacket. The mix-5 ing blades were mounted on two oppositely rotatingshafts. One shaft was rotated at 26 rpm while the other rotated at 52 rpm. Dropping funnels were used to feed the mercaptan, maleic anhydride, and Lupersol 130 solution into the reactor. The reactor was fitted with a nitrogen lO inlet and an exit vent.
The ethylene-propylene copolymer used above was a V.I. improver for lubricating oil and consisted of about 43 wt. ~ ethylene and about 57 weight Do propylene.
It had a Thickening Efficiency (T.E.) of about 2.8 which 15 represents a number average molecular weight of approxi-mately 609000. It was an amorphous copolymer with a MWlMn of less than 4:1Ø
Thickening Efficiency (T.E.) is defined as the ratio of the weight percent oF a polyisobutylene (sold as 20 an oil solution by Exxon Chemical Co. as Paratone N), having a Staudinger Molecular Weight of 20,000, required to thicken a solvent-extracted neutral mineral lubricat-ing oil, having a viscosity of 150 SUS at 37.8C., a viscosity index of 105 and an ASTM pour point of 0F., 25 (Solvent 150 Neutral) to a viscosity of 12.4 centistokes at 98.9C., to the weight percent of a test copolymer required to thicken the same oil to the same viscosity at the same temperature. T.E. is related to (Mn) and is a convenient, useful measurement for formulation of lubri-30 cating oils of various grades.EXAMPLE_2 200 9. of the Product of Example 1, that ~s the oil solution of maleic anhydride grafted ethylene-propylene copolymer were charged to a 2 liter laboratory 35 resin kettle along with 200 9. oF 5100NLP mineral lubri-cating oil. The kettle was equipped with a heating ~2~a~

mantle, a dropping funnel, stirrer, overhead water con-denser, vacuum pump and a nitrogen inlet for maintaining a nitrogen atmosphere. The temperature was raised to 190C. while stirring and nitrogen sparging. The tem-5 perature was maintained at 190C. for one hour to removeany moisture or volatiles. Then 1.16 9. of 2-aminomethyl pyridine dissolved in 2.38 9. of 5100NLP were added over 10 minutes, followed by continued heating at 190C. and mixing while under nitrogen for one hour. The reaction 10 mixture was then nitrogen stripped for one hour after which the temperature was lowered to 150C. and 272 9. of S100NLP were added and mixed for 15 minutes, followed by nitrogen sparging for one hour. The reactor was then drained to give the Product of Example 2 which was an oil lS solution of tl~e aminated maleic anhydride grafted ethy-lene propylene rubber. This Product had a K.V. (Kine-matic Viscosity) of 1779 centipoise at 100C. and was useful as a Viscosity Index improving - sludge dispersant additive, e.g. for lubricating oils.
The Product of Example 2 was tested for stor-- age stability by storing in an oven at 80C. At the end of two weeks in the oven, the K.V. at 100C. was 1768 centipoise. After four weeks in the oven, the K.V. at 100C. was 1745 centipoise, indicating good thermal 25 storage stability.

200 grams of the Product of Example 1 were added to the 2 liter resin kettle along with 20û grams of S100NLP. The temperature was raised to 190C. while stir-30 ring and nitrogen sparging for a period of one hour. 1.16grams of 2-aminomethyl pyridine dissolved in 2.38 grams of S100NLP were added over a 10-minute period and reacted for one hour, while continuing the nitrogen sparging.
Then the reaction mixture was nitrogen stripped for one 35 hour at 190C, after which the temperature was lowered to 150C and 272 grams of S100NLP were added and mixed for 15 minutes, followed by sparging with nitrogen for ano-ther hour. The reaction mixture was then drained to give the product having a K.V. at 1ûûC. of 1779 centistokes.

The 2 liter resin kettle was charged with 20û
grams of the Product of Example 1 and 2ûû grams of 5100NLP. The temperature was raised to 19ûC. while stirring and nitrogen sparging, which conditions were maintained for one hour, after which 0.90 grams of 2-aminopyrimidine were added and reacted for one hour under nitrogen. The reaction mixture was then stripped with nitrogen for one hour at 190C., after which the tempe-rature was lowered to 150C. and 272 grams of 510ûNLP
were added and mixed for 15 minutes. The reactor was 15 then drained ~o give the product having a K.V. at 10ûC.
of 1774 centistokes.

The 2 liter rresin kettle was charged with 20û
, grams of the Product of Example 1 and 200 grams of 5100NLP. The tetnperature was raised to 190C. while nitrogen sparging and stirring For one hour, after which 1.52 grams of 2-amino benzothiazole were added and re-acted for one hour. The reaction mixture was then nitro-gen stripped for one hour at 190C., after which the 25 temperature was lowered to 15ûC. and 272 grams of S1û0NLP were added and mixed for 15 minutes, following which the reactor was drained to give the product having a K.V. at 10ûC. oF 2184 centistokes.
EXAM
The 2 liter resin kettle was charged with 200 grams of the Reaction Product of Example 1 and 200 grams of 5100NLP.The temperature was raised to 190C. while stirring under a nitrogen sparge and maintained for one hourO At the end of this time, 1.1 grams of 2-aminothia-zole were added and reacted for one hour under the nitro-gen. The reaction mixture was then nitrogen stripped for one hour at 190C. The temperature was lowered to 150C.
and 272 grams of nitrogen sparged 5100NLP were added and 5 mixed for 15 minutes9 after which the reactor was drained to give the product having a K V. at 1û0C. of 1810 centistokes.

The 2 liter resin kettle was charged with 200 lO grams of the Product of Example 1 and 200 grams of 5100NLP. The temperature was raised to 190C. while stirring and nitrogen sparging. Then 1.2 grams of 1-methyl-1-phenylhydrazine dissolved in 2.4 grams of 5100NLP were added over a 10-minute period and reacted 15 for one hour while lightly sparging with nitrogen. The reaction mixture was then nitrogen stripped for one hour at 190C. The temperature was lowered to 150C. and 272 grarns of SlOONLP were added and mixed for 15 minutes. The 272 grams of S100NLP had been previously nitrogen sparged 20 for one hour before adding. The reaction mixture was then drained to give the product having a K.V. at 100C.
of 1826 centistokes.

The 2 liter resin kettle was charged with 500 25 grams of the Reaction Product of Example 1 and 500 grams of 5100NLP. The temperature was raised to 190C. while stirring and nitrogen sparging and held there for one hour. The temperature was then lowered to 150C. and 5.5 grams of N-isopropylethylene diamine were added over a 30 15-minute period, following which the temperature was raised to 190C. and the amine reacted for a one-hour period. The reaction rnixture was then nitrogen stripped for one hour at 190C., cooled to 150C. where 680 grams of 5100NLP were added and mixed for 15 minutes. Follow-35 ing this, the reactor was drained to give the producthaving a K.V. at 100C. of 1438 centistokes.
.

~ ~6~

The 2 liter resin kettle was charged with 200 grams of the Reaction Product of Example 1 and 200 grams of 5100NLP. The temperature was raised to 190C. and held there for one hour while stirring and nitrogen sparging. Then 1.08 grams of N-aminomorpholine were added slowly and reacted for one hour at 190C. The reaction mixture was nitrogen stripped for one hour at 190C., following which the temperature was lowered to 150C. and 272 grarns of 5100NLP were added and mixed for 15 minutes.
The reactor was then drained to give the final product having a K.V. at 100C. of 2376 centistokes and a nitr-ogen content of 0.28 wt. ~.

1816 grarns of Nordel 1320 was added to the re-actor, that i; the 9 5 liter masticator, and heated at 140C. under nitrogen until banding occurred. Then, 20 grams of octadecyl mercaptan, 14.4 grams of N-vinyl pyr-rolidone and 3.S grams of Lupersol 130 were added to the reactor followed by heating to 170C. for 45 minutes, while mixing under nitrogen~ The reactor was then cooled to 140C. and 10 grams of octadecyl mercaptan, 14.4 grams of N-vinyl pyrrolidone and 3.6 grams of Lupersol 130 was added to the reactor while mixing and stirring under nitrogen. The masticator, that is the reactor, was heated to 170C. for 60 minutes under nitrogen while continuing mixing, following which 4540 grams of 5100NLP were added and mixed in for about one hour. The masticator was drained to give the final product which was an oil solu-tion of an ethylene copolymer grafted with N-vinyl pyr-rolidone, which would be useful as a V.I. dispersant modifying additive in lubricating oil. The final product had a kinetic viscosity at 100C. of 1080 centipoise and the grafted polymer therein had a T.E. of 1.65.

~L26~L88~

Nordel 1320 is a terpolymer of about 53 wt. O~D~
ethylene, about 43.5 wt. O propylene and about 3.5 wto Do of 1,4-hexadiene. It has a Mooney viscosity at 100 C. of about 25 and is sold by the DuPont Company.

1816 grams of the ethylene-propylene rubber used in Example 1 of 2.8 T.E. were added to the 9.5 liter masticator which was then mixed ~or 45 minutes at 120C. under nitrogen to form a band. Then 2 grams of 10 Pennstop 2697, which is diethyl hydroxyamine sold as a commercial chain stopping agent, were added over a period of about five minutes. Then 30 grams of N-vinyl pyrro-lidone was added over a 5-minute period. This was fol-lowed by the addition of 2 grams of Di-CUP-R ~dicumyl 20 peroxide), dissolved in 4 grams of polyisobutylene of 500 molecular weight over a 5-minute period. The temperature of the reaction mass was then raised to 160C. and maintained for a soak period of 30 minutes. 30 grams of N-vinyl pyrrolidone was added at the 160C. temperature 25 followed by 2 grams of DI-CUP-R dissolved in 4 grams of the 500 molecular weight polyisobutylene~ followed by a heat soaking period, while mixing, of 60 minutes at 160C. After this, the temperature was raised to 175Co and 10 lbs. of 5100NLP were added, followed by nitrogen 30 stripping for 1-1/4 hours. The reactor was then drained to give thP final product having the following charac-teristics:
K.V. at 100C. = 1467 centistokes Nephelometer Haze = 71 (At a reading of about 75 haze will become visible to the naked eye.);
Nitrogen Content of 0.30 wt. O based on the grafted polymer; and a T.E. for the grafted polymer of 2.60.

~Z~i~8~

1816 grams of the ethylene-propylene rubber of Example 1 was added to the 9.5 liter masticator reactor and mixed for 45 minutes at 120C. under nitrogen. Then 2 grams of Pennstop 2697 were added and mixed in. 30 grams of N-vinyl pyrrolidone were added over a 5-minute period followed by the addition of 2 grams of Di-CUP-R
dissolved in 4 grams of polyisobutylene of 500 molecular weight (PIB 500) over a period of 5 minutes. The tem-perature was then raised to 160C. and maintained for asoak period of 30 minutes. Following this 1 gram of Penn-stop 2697 was added over 5 minutes, 30 grams of N-vinyl pyrrolidone was added over 5 minutes, followed by the addition of 2 grams of Di-CUP-R, in 4 grams of PIB 500 in 15 5 minutes, later followed by 5 minutes of mixing. Then 2 grams of Di-CUP-R in 4 grams of PIB 500 was added, Fol-lowed by 5 minutes of mixing. Then 2 grams of Pennstop 2697 was added followed by mixing for 5 minutes. Next, 30 grams of N-vinyl pyrrolidone was added followed by 20 mixin9 for 5 minutes, followed by the addition of 2 grams of Di-CUP-R dissolved in 4 grams of PIB 500 followed by 5 minutes of mixing. The reactor contents were then heat soaked for 30 minutes at 160C., followed by heating to 175C. which temperature was maintained for 30 minutes.
25 10 lbs. of S100NLP were added, followed by nitrogen stripping for 1-1/4 hours. The reactor was then drained to give a product containing 0.43 wt. Do nitrogen, based on the weight of grafted polymer, having a kinetic vis-cosity at 100C of 969 centistokes, and containing a 30 polymer having a T.E. of 1.36. At a 14.3 wt. O concen-tration of the reaction product in oil, the nephelometer haze reading was +111, indicating that visible haze was present.

Comparison Examples A to E
A series of examples were carried out in~which the chain stopping agent was not used, which shows that the resulting material that formed resulted in the forma-5 tion of gel and was not completely oil-soluble.
Comparison Example A
1.8Kg of ~he ethylene-propylene copo-lymer rubber of Example 1 having a T.E. of about 2.8 were added to the masticator. The copolymer was heated and lO mixed in the presence of air until its T.E. had been reduced to 2.1. The masticator was then flushed with nitrogen and 35 grams of maleic anhydride was added, while the temperature was raised to 175C. as the mate-rial was worked in the masticator. 5 grams of Lupersol 15 130 were dissolved in a sufficient amount of SlOONLP to make 50 milliliters (10~o active ingredient) of the oil solution of the initiator. 20 milliliters of this solu-tion were added while mixing at 175C. under nitrogen. 30 mirlutes later another 10 milliliters of the solution were 20 added. Ten minutes later another 1û milliliters of the peroxide solution were added. Ten minutes later still another 10 mil. of peroxide solution were added. This stage addition, i.e. periodic addition was done in order to obtain good dispersancy of the peroxide in the solid 25 ethylene-propylene copolymer. The masticator contents were soaked, that is mixed, under the nitrogen blanket for another 60 minutes, after which 4540 9. of Solvent 1ûONLP were added and mixed, followed by draining the reactor to give the product.
Comparison Examples B to E
These were carried out in the same manner noted above except for the changes noted in the following Table Comparison Examples A to E are summarized in the following Table.

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e ~ e _ E -~ e ~ u~ o O o o o o o o o ~g e~g ~ g ~ ~ g c ~ e _ e ~
OO O O O O O O O O O O

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e ~ e O e _~
~ ~ u~ Oo o o _ o o o x ~ ~

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~ ~o ~o ~ ~ ~ o 8 ~bO e e e ~1 oo u~ o o o o o o o o ~D~o hJJ O O O O O O
e h~09E~ ~ e ~ e O E~
C~ ~ e e e e e e e e e e ~ e C ^ C ~ ~ ~ ,, d ~-~ d --1 d .--1 C
rl O ~ O t~ O ~ O ~ O t-d O
rl - h U ~ ~1 1.1 ~1 ~ Ll h 6 ~ C to d ¢ 5 ¢ d 6 C
c ¢ ~ W e .~ E~ o e ~ e , ~ c r ~

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O O ~ O ~-r~
I` O ~: ~ h ~ _,_ z ~ e~

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a ,_ ~

o C~ ~ a O
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Examples A to D of the Table show that even adding the peroxide in small increments, without the chain stopper did not prevent gelling. Example D used only 1.25 9. of actual peroxide and still gelling oc-5 curred. Example E shows that without the peroxide nosubstantial amount of grafting occurrecl.

_ Part A
i5,4;~g of the solid ethylene-propylene copo-lymer rubber used in Example 1 was added to a 190 literrubber masticator in the form of five 9.1 Kg pieces. The copolymer was masticated and nitrogen stripped in the Dow-Therm heated masticator until the temperature reached 99C 0 . 45 Kg of t.-dodecyl mercaptan was added through a ~5 dropping funnel over a 15 minute period, followed by the j~
addition of 0.95 Kg of melted maleic anhydride, added through said dropping funrlel. Initially, 100 ml. oF the maleic anhydride was added. Then the remaLning maleic anhydride was added over a 15 minute period simultane-ously while adding 0 Al Kg of 0.54 Kg o~ an initiator solution that had been made up consisting of 0.09 Kg ditertiary butyl peroxide dissolved in a mixture consist-ing of 0. 32 Kg of PIB 50û and 0.14 Kg of ISOPAR M ~TM) which is a hydrocarbon solvent. After this 15 minute period, then the remaining 0.13 Kg of said initiator solution were added over a five minute period. This last addition was followed by soaking and mixing for 5D min-utes, followed by nitrogen stripping. Then 193 Kg 5100NLP oil, which have been previously sparged with nitrogen to remove moisture and volatiles, were added to the masticator in a series of small increments, each increment being mixed into the reaction mass before the next increment. The first increment was 9.1 Kg followed by increments of 11.3 Kg, 13.6 Kg, 18.1 Kg,. 22.7 Kg, 35 22. 7 Kg, 22. 7 Kg, 22 . 7 Kg and then the balance. The t~r~erature was lowered ts~ 93C. ~ile rlux~ng continued. l~en the masticator was drained to give the oil solution of--the ethylene copolymer rubber grafted with maleic anhy-dride. The concentrate titrated to 0.192 meq. acid/g. of 5 the grafted polymer.

Part B
A reactor was charged with 45~4 X-g:of ~50NLP
mineral lubricating oil which was heated to 100C. and nitrogen stripped. Following this, 45.4 Kg, o~ the oil 10 solution of the ethylene copolymer grafted with maleic anhydride prepared in Part A were added to the reactor followed by mixing, nitrogen stripping and heating until the temperature reached 190C. Then9 0.16 Kg of N-aminopropyl marpholine (NAPM) dissolved in 0.45 Kg of said 15 oil was added over a 20-minute period to the reactor through an inlet line which was then followed with 0.23 Kg of said oil to flush the line. Mixing and heating continued for one hour under nitrogen after which 8.6 ICg of said oil were added, followed by vacuum stripping for 20 one hour and then draining to give the final product, which was useful as a multi-functional V.I.-dispersant additive concentrate. This product analyzed 0.27 wt. O
nitrogen based on the weight of the polymer, i.e. the aminated grafted polymer. The aminated grafted polymer 25 had a T.E. of 2.46. The haze level of the concentrate was at a nephelometer reading of 102.

A lubricating oil composition was prepared by mixing 13 wt. ~O~ based on the weight of the total compo-30 sition, of the final product of Part B of Example 13;that is, the oil concentrate of the V.I. dispersant addi-tive, about 1.4 wt. ~ of a nonylphenol sulfide additive as an antioxidant, 1.3 wt. O of an overbased 400 Total Base No. magnesium sulfonate additive, 1.8 wt. O of a 35 zinc dialkyldithiophosphate additive (about 75 wt. ~O

active ingredient), 0.25 wt. O of a pour depressant addi-tive, and about 82.25 wt. ~0 of a mineral-lubricating oil, to form a 10W40 crankcase oil having a viscosity of about 14.5 centistokes at 1û0C. This oil was tested in the 5 MS-VD test and passed, having a sludge rating of 9.63; a varnish rating of 7.04; a piston skirt varnish rating of 6.77; a cam and lifter wear average of 0.:013 cm and a maximum cam wear of 0.020 cm.

A 10W40 lubricating oil composition was pre-pared showing the material of the invention supplemented by other dispersants, by mixing about 12 wt. O~ based on the total composition, of the final product of. Part B of Example 13, 1.1 wt. ~0 of antioxidant, 2.2o of an over-15 based metal sulfonate, 1.45 wt. O of a zinc dithiophos-phate additive, and other dispersant/detergents along with antifoam, antifriction, and pour depressant addi-tives, with 74.5 wt. ,0 of lubricating oil.

Claims (19)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process comprising grafting a hydro-carbon polymer of C2 to C28 olefin, said polymer having a number average molecular weight in the range of about 5,000 to 500,000 with an unsaturated material selected from the group consisting of: (A) ethylenically unsatu-rated C3 to C10 carboxylic acid having 1 to 2 carboxylic acid groups or an anhydride group, and (B) nitrogen-con-taining ethylenically unsaturated monomers containing 6 to 30 carbon atoms and 1 to 4 nitrogen atoms, in the presence of a free radical initiator and a chain stopping agent.

2. A process according to claim 1, wherein said hydrocarbon polymer is a hydrogenated copolymer of styrene with at least one aliphatic diene selected from the group consisting of butadiene and isoprene.

3. A process according to claim 1, wherein said hydrocarbon polymer is a copolymer of ethylene with a C3 to C28 alpha olefin.

4. A process according to claim 2, wherein said hydrocarbon polymer consists essentially of ethylene and propylene.

5. A process according to claims 1-3, wherein said grafting is carried out in the substantial absence of solvent, and the grafted material is subsequently mixed with mineral lubricating oil to form an oil concentrate.

6. A process according to claim 1, wherein a homogeneous mixture is formed of said ethylene copolymer, unsaturated material, initiator and chain stopping agent by heating and mixing at a first temperature below the temperature at which said initiator generates substantial free radicals, and then heating and mixing at a second higher temperature at which said initiator generates substantial free radicals and a major proportion of said grafting takes place.

7. A process according to claim 6, wherein said first temperature is in the range of about 100 to 160°C. and said second temperature is in the range of about 170 to 240°C.

8. A process according to claims 6 or 7 wherein said process is carried out in multiple stages, said first stage comprising forming said homogeneous mixture at said first temperature, then heating and mixing at said second temperature to effect grafting; and at least one additional stage of cooling to said first tempera-ture, adding additional unsaturated material, initiator, and chain stopping agent at said first temperature and reheating and mixing to said second temperature to effect grafting of said additional unsaturated material.

9. A process according to claims 1-3, wherein said ethylene copolymer is a normally solid rubber at room temperature and mixing is carried out in a mechan-ical mixer which heats and kneads said rubber, unsatu-rated material, initiator and chain stopping agent into a homogeneous solid rubbery mass in which grafting takes place in the solid state.

10. A process according to claims 1-3, wherein said unsaturated material is maleic anhydride.

11. A process according to claim 1, wherein said graft material is dissolved in a mineral lubricating oil and reacted with an amine having 2 to 60 carbon atoms and 1 to 12 amine groups to form an oil soluble Visco-sity-Index improving - dispersant additive concentrate.

12. A process according to claim 11, wherein said amine is a polyamine having at least one primary amine group.

13. A process according to claims 3 or 4, wherein said copolymer consists essentially of about 30 to 80 weight % ethylene and about 20 to 70 weight % propylene, and has a number average molecular weight in the range of about 10,000 to 200,000.

14. A process according to claims 1-3, wherein said free radical initiator is a peroxide.

15. A process according to claims 1-3, wherein said chain stopping agent is a C4 to C24 aliphatic mercaptan.

16. A process according to claims 1-3 or 13-15, wherein said nitrogen containing monomer is selected from the group consisting of vinyl pyridines, vinyl pyrrolidones, acrylates and methacrylates.

17. A process according to claims 3 or 4, wherein said ethylene copolymer is a terpolymer of ethylene, propylene and an unsaturated diene.

18. The product produced by a process according to claim 1.

19. A lubricating oil composition comprising a lubricating oil and the product of claim 18.