CA2077835A1 - Dispersant polymethacrylate viscosity index improvers - Google Patents

Dispersant polymethacrylate viscosity index improvers

Info

Publication number
CA2077835A1
CA2077835A1 CA002077835A CA2077835A CA2077835A1 CA 2077835 A1 CA2077835 A1 CA 2077835A1 CA 002077835 A CA002077835 A CA 002077835A CA 2077835 A CA2077835 A CA 2077835A CA 2077835 A1 CA2077835 A1 CA 2077835A1
Authority
CA
Canada
Prior art keywords
methacrylate
polymer
weight
alkyl
methyl
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002077835A
Other languages
French (fr)
Inventor
Chung Y. Lai
John O. Naples
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rohm and Haas Co
Original Assignee
Rohm and Haas Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rohm and Haas Co filed Critical Rohm and Haas Co
Publication of CA2077835A1 publication Critical patent/CA2077835A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M145/00Lubricating compositions characterised by the additive being a macromolecular compound containing oxygen
    • C10M145/02Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M145/10Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate
    • C10M145/12Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate monocarboxylic
    • C10M145/14Acrylate; Methacrylate
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10Esters
    • C08F220/12Esters of monohydric alcohols or phenols
    • C08F220/16Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1811C10or C11-(Meth)acrylate, e.g. isodecyl (meth)acrylate, isobornyl (meth)acrylate or 2-naphthyl (meth)acrylate
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M107/00Lubricating compositions characterised by the base-material being a macromolecular compound
    • C10M107/20Lubricating compositions characterised by the base-material being a macromolecular compound containing oxygen
    • C10M107/22Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M107/28Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10Esters
    • C08F220/12Esters of monohydric alcohols or phenols
    • C08F220/16Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1818C13or longer chain (meth)acrylate, e.g. stearyl (meth)acrylate
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2203/00Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
    • C10M2203/10Petroleum or coal fractions, e.g. tars, solvents, bitumen
    • C10M2203/102Aliphatic fractions
    • C10M2203/1025Aliphatic fractions used as base material
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2207/00Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
    • C10M2207/02Hydroxy compounds
    • C10M2207/023Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
    • C10M2207/028Overbased salts thereof
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2209/00Organic macromolecular compounds containing oxygen as ingredients in lubricant compositions
    • C10M2209/02Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M2209/08Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate type
    • C10M2209/084Acrylate; Methacrylate
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2215/00Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
    • C10M2215/28Amides; Imides
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2219/00Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2219/00Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
    • C10M2219/04Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions containing sulfur-to-oxygen bonds, i.e. sulfones, sulfoxides
    • C10M2219/046Overbasedsulfonic acid salts
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2223/00Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
    • C10M2223/02Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
    • C10M2223/04Phosphate esters
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2223/00Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
    • C10M2223/02Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
    • C10M2223/04Phosphate esters
    • C10M2223/045Metal containing thio derivatives
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2229/00Organic macromolecular compounds containing atoms of elements not provided for in groups C10M2205/00, C10M2209/00, C10M2213/00, C10M2217/00, C10M2221/00 or C10M2225/00 as ingredients in lubricant compositions
    • C10M2229/02Unspecified siloxanes; Silicones
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2010/00Metal present as such or in compounds
    • C10N2010/04Groups 2 or 12
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01Physico-chemical properties
    • C10N2020/04Molecular weight; Molecular weight distribution
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/02Pour-point; Viscosity index
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/04Detergent property or dispersant property
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/36Seal compatibility, e.g. with rubber
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00Specified use or application for which the lubricating composition is intended
    • C10N2040/04Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
    • C10N2040/042Oil-bath; Gear-boxes; Automatic transmissions; Traction drives for automatic transmissions
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00Specified use or application for which the lubricating composition is intended
    • C10N2040/25Internal-combustion engines
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2070/00Specific manufacturing methods for lubricant compositions
    • C10N2070/02Concentrating of additives

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Emergency Medicine (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Lubricants (AREA)

Abstract

ABSTRACT
This invention relates to copolymers derived from (a) monomers selected from the group consisting of (C1-C24)alkyl methacrylates and (C1-C24)alkyl acrylates and (b) a monomer selected from the group consisting of hydroxy(C2-C6)alkyl methacrylates and hydroxy(C2-C6)alkyl acrylates wherein the number of carbon atoms in the alkyl groups averages from about 7 to about 12. These polymers are useful as additives to lubricating oils for providing viscosity index improvement, dispersancy and low temperature fluidity properties without adversely affecting fluoropolymer seals and gaskets.

Description

DISPERSANT POLYMETHACRYLATE VISCOSITY INDEX
IMPROVERS

RELA7 lED U.S. APPLICATION DATA
This application is a continuation-in-part of co-pending application Serial Number 854,924 filed March 20, 1992.

BACKGRS)UND OP THE INVENTION
This invention relates to polymers derived from (a) monomers selected from the group consisting of (Cl-C24)aLkyl methacrylates and (Cl-C24)aLlcyl acrylates and (b) a monomer selected from the group consisting of hydroxy(C2-C6)alkyl methacrylates and hydroxy(C2-C6)alkyl acrylates wherein the number of carbon atoms in the alkyl groups averages from about 7 to about 12. These polymers are useful as additives to lubricating oils for providing viscosity index improvement, dispersancy and low temperature performance properties without adversely affecting fluoropolymer seals and gaskets. The novel polymers are normally dissolved or dispersed in refined rnineral lubricating oil for eventual incorporation in a mineral or synthetic base oil.
Desirable lubricating oils for internal combustion engines, automatic transmission fluids and hydraulic fluids have relatively little change in viscosity over a wide range of temperatures, dispersant properties and good fluidity at low temperatures, including low pour point. Viscosity index (or VI) is a measure of the degree of viscosity change as a function of temperature; high viscosity index values indicate a smaller change in viscosity with temperature variation compared to low viscosity index values. Viscosity index improver additives having high viscosityindex values coupled with good low temperature fluidit,v allow the oil to flow at the lowest possible temperature of operation, usually at engine start-up, and, as the temperature increases into the operating range, the viscosity remains at a levelsuitable for good performance.
Polymeric additives have been used to improve the performance of engine - -$5 lubricating oils in regard to several of these properties. Polymers of alkyl acrylates or alkyl methacrylates have been used successfully as viscosity index improvers andpour point depressants. Enhanced dispersant properties may be introduced into the polymer compositions by using polar, particularly basic comonomers, such as vinyl heterocycles (N-vinylpyrrolidone, N-vinylimiclazole, vinylpyridine and the like), dialkylaminoalkyl methacrylates, N,N-dialkylaminoalkyl methacrylamides and the like. However, grafting conditions needed to incorporate the nitrogen-containingbasic comonomers very often introduce poor shear stabllity characteristics. In addition, viscosity index improvers containing nitrogen-containing basic comonomers may cause objectionable odor or degrade the effectiveness of gaskets and seals found in automobile engines that are based on fluoropolymers, such as VitonTM fluoroelastomer.
U.S. 3,311,597 discloses an approach to improved viscosity index and dispersant properties of poly(methacrylate) polymers which involves the copolymerization of alkyl methacrylates with tetrahydrofurfuryl methacrylate andthe optional incorporation of hydroxyethyl methacrylate, hydroxypropyl meth-acrylate, N-vinyl pyrrolidone or t-butylaminoethyl methacrylate. Poly(alkylmeth-acrylate) polymers having improved pour point properties based on copolymerizingalkyl methacrylates with from 9 to 23 mole percent methacrylic acid followed by ethoxylation, wherein the average number of carbon atoms in the alkyl group is 12.5 to 14.3, are disclosed in U.S. 3,598,737. A lauryl methacrylate-stearyl methacrylate copolymer with 23 mole percent hydroxyethyl methacrylate is disclosed in U.S.
3,249,545 for use in oil formulations containing bisphenol antioxidants.
In another approach to providing dispersant viscosity index improvers, EP
418610A disdoses the use of polyalkyl(meth)acrylates characterized in that 80-95.5%
by weight of the copolyIner is derived from (C6-C24)alkyl(meth)acrylates and 0.5-20%
is derived from a hydroxy(C2-C6)alkyl(meth)acrylate or a multialkoxylized alkyl-(meth)acrylate with an optional 0-17% by weight being derived from (C1-Cs)alkyl~(meth)acrylates.
Poly(methacrylate~ polymers as additives for machine tool working oils based .

. , . . ., :

,. . . . - :
. ~ , . .~ - , .
- : ~
- : ' ~ :: ' , ' .- . , ~ , .
- : .

on 92-99% (C1-Cl8)alkyl methacrylate and 1-8% hydroxy(C2-C3)alkyl methacrylate pol,vmers having number-average molecular weights (Mn) of 20,000-60,000 are disclosed in Japanese Patent JP 52-018202B. These polymeric additives are disclosed as being unsuitable for use as dispersant viscosity index improver additives forengine oils.
None of these latter approaches combines dispersancy, good viscosity index and compatibility with fluoropolymer sealing materials with good low-temperaturefluidity in a single polymer and it is an object of the present invenlion to provide this combination of properties in a single poly~ner.

SUMMARY OF THE INVENTION
This invention relates to polymers derived from polyrnerizing monomers comprising (a) from about 90 to about 98 weight percent of a monomer selected from the group consisting of (C1-C24)alkyl methacrylates and (C1-C24)alkyl acrylates and (b) from less than 10 to about 2 weight percent of a monomer selected from the groupconsisting of hydroxy(C2-C6)alkyl methacrylates and hydroxy(C2-C6)aLl~yl acrylates wherein the number of carbon atoms in the side chain alkyl groups of the backbone polymer averages from about 7 to about 12. These polymers are llseful as additives to lubricating oils for providing viscosity index improvement, dispersancy and low temperature performance properties without adversely affecting fluoropolymer seals and gaskets. The novel polymers, when used in lubricating oils, are normally dissolved or dispersed in refined mineral lubricating oil for eventual incorporation in a mineral or synthetic base oil. Examples of lubricating oils include crankcase engine oils, automatic transmission fluids, hydraulic fluids, gear oils and shock absorber fluids.

DETAILED DESCRIPTION OF THE INVEN~ION
Each of the monomers used in the present invention can be a single monomer or a mixture having different nurnbers of carbon atoms in the alkyl portion. The alkyl portion of both the (a) methacrylate and acrylate monomers and the (b) hydroxyalkyl methacrylate and acrylate monomers is an important factor ir the performance characteristics of the polymers of the inve.ntion. By this is meant that the average number (n) of carbon atoms (Cn) in the side chain alkyl and hydroxy-alkyl groups of the acrylate or methacrylate backbone ~olymer is selected to maximize viscosity index characteristics and to maintain oil solubility of the pol,vmer additive in both new oil and in used oil, where the additive has functioned as a sludge dispersant. Generally, when the average Cn is less than about 7, theresultant polymers may have poor solubility in the base oils and the additives may not be fully functional as dispersant viscosity index improvers. When the average Cn is significantly greater than about 12, poorer low temperature fluidity properties may be observed. By low temperature is meant temperatures below about -5C::.
Consequently, the average number of carbon atoms in the alkyl group of the acrylate or methacrylate monomers used to prepare the polymeric additives is from about 7to about 12, preferably from about 8 to about 10. In the instance where the monomers are all acrylates or substantially all acrylates, then the average carbon number of the side chain alkyl groups of the backbone polymer will vary somewhatand the average number of carbon atoms will be that which matches the solubilityparameters of the corresponding methacrylate backbone polymers. Such solubility parameters are readily known and understood by those in the art.
Preferably, monomer (a) is selected from the group consisting of (C1-C20)alk methacrylates and (Cl-C20)alkyl acrylates and monomer (b) is selected from the group consisting of hydroxy(C2-C6)alkyl methacrylates and hydroxy(C2-C6)alkyl acrylates. The allcyl portion of either monomer may be linear or branched. Alkylmethacrylates and hydroxyaLIcyl methacrylates are preferred.
To obtain a balance of desired performance characterisistics relating to viscosity index improvement, good dispersancy and low temperature performance, rnixtures of aLkyl methacrylates and alkyl acrylates are used. Consequently, in one embodiment of the invention, monomer (a) generally comprises (i) O to about 40%
of an alkyl methacrylate or alkyl acrylate in which the alkyl group contains from 1 to 6 carbon atoms, and mixtures thereof, (ii) frorn about 30 to about 90% of an alkyl . j ~ . . . .
.
, .
--methacrylate or alkyl acrylate in which the alkyl group contains from 7 to 15 carbonatoms, and mixtures thereof, and (iii) 0 to about 40% of an alkyl methacrylate or alkyl acrylate in which the alkyl group contains from 16 to 24 carbon atoms, andmixtures thereof, and monomer (b) comprises from less than 10 to about 2% of a hydroxyalkyl methacrylate or hydroxyaL~yl acrylate in which the alkyl group contains 2 to 6 carbon atoms and is substituted with one or more hydroxyl groups.
All percentages are by weight, are based on the total weight of the polymer and the total of (i), (ii), (iii) and (b) equals 100 percent of the weight of the polymer. The amount of (i) in the polymer is preferably from ~ to about 25%; the amount of (ii) is preferably from about 45 to about 85% and more preferably from about 50 to about60%; the amount of (iii) is from about 5 to about 35% and more preferably from about 25 to about 35%; and the amount of (b) is preferably from about 4 to about 8%
and more preferably about 5 to about 6%.
Examples of monomer (a), the alkyl methacrylate or alkyl acrylate where the alkyl group contains from 1 to 6 carbon atoms, also called the "low-cut" alkyl methacrylate or alkyl acrylate, are methyl methacrylate (MMA), methyl and ethyl acrylate, propyl methacrylate, butyl methacrylate (BMA) and acrylate (BA), isobutyl methacrylate (IBMA), hexyl and cyclohexyl methacrylate, cyclohexyl acrylate and combinations thereof. Preferred low-cut alkyl methacrylates are methyl methacrylate and butyl methacrylate.
Examples of monomer (a~, the alkyl methacrylate or alkyl acrylate where the alkyl group contains from 7 to 15 carbon atoms, also called the "mid-cut" aLkyl methacrylates or alkyl acrylates, are 2-ethylhexyl acrylate (EHA), 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, isodecyl methacrylate (ID~A, based on branched ~CIo)alkyl isomer mixture), undecyl methacrylate, dodecyl methacrylate (also known as lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (also known as myristyl methacrylate), pentadecyl methacrylate and combinations thereof. Also useful are: dodecyl-pentadecyl methacrylate (DPMA), amixture of linear and branched isomers of dodecyl, tridecyl, tetradecyl and penta-decyl methacrylates; and lauryl-myristyl methacrylate (LMA), a mixture of dodecyl IJ~J~
and tetradecyl methacrylates. The preferred mid-cut alkyl methacrylates are lauryl-myristyl methacrylate and isodecyl methacrylate.
Examples of monomer (a), the alkyl methacrylate or alkyl acrylate where the aLkyl group contains from 16 to 24 carbon atoms, also called the "high-cut" alkyl methacrylates or alkyl acrylates, are hexadecyl rnethacrylate, heptadecyl meth-acrylate, octadecyl methacrylate, nonadecyl met'hacrylate, cosyl methacrylate, eicosyl methacrylate and combinations thereof. Also useful are: cetyl-eicosyl methacrylate (CEMA), a mixhlre of hexadecyl, octadecyl, cosyl and eicosyl methacrylate; and cetyl-stearyl methacrylate (SMA), a rnixture of hexadecyl and octadecyl methacrylate. The preferred high-cut alkyl methacrylates are cetyl-eicosyl methacrylate and cetyl-stearyl methacrylate.
The mid-cut and high-cut alkyl methacrylate and alkyl acrylate monomers described above are generally prepared by standard esterification procedures using technical grades of long chain aliphatic alcohols, and these commercially available alcohols are mixtures of alcohols of varying chain lengths containing between 10and 15 or 16 and 20 carbon atoms in the alkyl group. Consequently, for the purposes of this invention, alkyl methacrylate is intended to include not only the individual alkyl methacrylate product named, but also to include mixhlres of the alkyl meth-acrylates with a predorninant amount of the particular alkyl methacrylate named.The use of these commercially available alcohols to prepare acrylate and meth-acrylate esters results in the LMA, DPMA, SMA and CEMA monomer mixtures described above.
Examples of monomer (b) are those alkyl methacrylate and acrylate monomers with one or more hydroxyl groups in the aLkyl radical, especially thosewhere the hydroxyl group is found at the ,B-position (2-position) in the alkyl radical.
HydroxyaL~cyl methacrylate and acrylate monomers in which the substituted alkyl group is a (C2-C6)aLkyl, branched or unbranched, are preferred. Among the hydroxy-alkyl methacrylate and acrylate monomers suitable for use in the present invention are 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate, 2-hydroxypropylmethacrylate, l-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, ::
` : .
.

l-methyl-2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate and 2-hydroxybutylacrylate. The preferred hydroxyalkyl methacrylate and acrylate monomers are HEMA, 1-methyl-2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate.
A mixture of the latter two monomers is commonly referred to as "hydroxypropyl methacrylate" or HPMA, which is a more preferred hydroxyalkyl methacrylate as are each of the components of the HPMA.
Among the hydroxyalkyl methacrylate and acrylates monomers of interest, preferred are those monomers which are essentially free of crosslinker or cross-linker precursor impurities and contaminants which may be present as a result ofthe method of preparation of the monomer. By crosslinker is meant any poly-functional material which causes crosslinking of the polymer, such- as ethylene glycol dimethacrylate. The presence of these crosslinker materials detracts fromproperties of the additives of the invention due to gel formation and related problems. Preferred hydroxyalkyl methacrylate and acrylates are those containingless than about 0.5%, more preferably less than about 0.2% and most preferably about 0.1% or less by weight of crosslinker or crosslinker precursor materials.
Preferred polymers are those where monomer (a) comprises monomers wherein (i) is selected from one or more of the group consisting of methyl meth-acrylate, butyl methacrylate and isobutyl methacrylate, (ii) is selected from one or more of the group consisting of 2-ethylhexyl methacrylate, isodecyl methacrylate, dodecyl-pentadecyl methacrylate and lauryl-myristyl methacrylate, (iii) is selected from one or more of the group consisting of cetyl-stearyl methacrylate and cetyl-eicosyl methacrylate, and monomer (b) is selected from one or more of the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 1-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 1-methyl-2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate and ?-hydroxybutylacrylate.
A preferred polymer is one in which monomer (a) is about 10% methyl methacrylate, about 55% isodecyl methacrylate and about 30% cetyl-stearyl or cetyl-eicosyl methacrylate, and monomer (b) is about 5% of a mixture of 2-hydroxypropyl .

methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
Another preferred polymer is one in wh;ch monomer (a) is about 20% butyl or isobutyl methacrylate, about 45% isodecyl methacrylate and about 30% cetyl-stearyl or cetyl-eicosyl methacrylate, and monomer (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
Another preferred polymer is one in which monomer (a) is about 15~o butyl or isobutyl methacrylate and about 80% lauryl-rnyristyl or dodecyl-pentadecyl methacrylate and monomer (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
Another preferred polymer is one in which monomer (a) is about 5 to about 10% methyl methacrylate, about 85 to about gO% lauryl-myristyl, isodecyl or dodecyl-pentadecyl methacrylate, and 0 to about 5% cetyl-eicosyl methacrylate and (b) isabout 5% of a mix of 2-hydroxypropyl and 1-methyl-2-hydroxyethyl methacrylate.
A polymer composition which is particularly preferred for use in automatic transmission fluids is one in which monomer (a) is 0 to about 5% methyl meth-acrylate, about 80 to about 90% lauryl-myristyl methacrylate and 0 to about 10% cetyl-eicosyl methacrylate, and monomer (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
Another preferred polymer composition for use in automatic transrnission fluids is one in which monomer (a) is 0 to about 20% butyl methacrylate, about 65 to about 90% lauryl-myristyl methacrylate and 0 to about 10% cetyl-eicosyl meth-acrylate, and monomer (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
Besides the average number (n) of carbon atoms (Cn) in the side chain alkyl and hydroxyalkyl groups of the acrylate or methacrylate backbone polymer, the nature of the alkyl portion of the methacrylate and acrylate monomers is an important factor in the performance characteristics of the polymers of the invention. For example, a mix of (C1-C6)alkyl methacrylates or acrylates, (C7-C1s)alkyl methacrylates or acrylates and (C16-C24)aL~cyl methacrylates or acrylates may be copolymerized with a hydroxyaL~cyl methacrylate such that ~e polymer has an average carbon number content in the alkyl side chains of about 9. In this case there is a good balance of viscosity index properties and solubility in base oils; in addition, the (Cl6-C24)aLkyl methacrylate portion of the polymer is wax-like and will interact with the waxy components in ~e base oil resulting in improved low-temperature properties, e.g., pour point, low temperature pumpability and cold-cranking engine ~tartup. If, on the other hand, a single (Clo) or (Cl2)alkyl meth-acrylate monomer is copolymerized with a hydroxyalkyl methacrylate to provide anaverage carbon number in the alkyl side chains of about 9, the resulting polymeradditive would have satisfactory oil solubility but little wax interactioll capability resulting in poorer low-temperature properties, such as poorer pumpability due to viscosity buildup, even though the Cn values are similar for both types of polymer.
Consequently, to obtain good low temperature performance properties, while retaining a good balance of viscosity index properties and solubility in base oils, it is preferred that a portion of monomer (a3 comprise from about 5 to about 40, preferably from about 5 to about 35 and more preferably from about 25 to about 35 weight percent of (Cl6-C24)alkyl methacrylates and (Cl6-C24)alkyl acrylates, preferably wherein the alkyl portion is Cl6 to C2n. Low temperature performance refers to viscosity under high shear and low shear conditions. For example, cold cranking startup of an engine, as measured by CCS (Cold-Cranking Simulator) viscosity, relates to viscosity at high shear conditions. On the other hand, pumpability of an oil at low temperatures, as measured by the mini-rotary viscometer (Ml~V), relates to viscosity under low shear conditions. Since the high-cut alkyl methacrylate and acrylates are wax-like, they act as pour point depressants changing the structure or morphology of the wax in the base oil at low temperatures. The amount of the high-cut alkyl methacrylate or acrylate used is dependent upon the particular high-cut alkyl methacrylate or acrylate selected, the properties of the base oil and the desired low temperature properties. Generally, the greater the number of carbons in the alkyl portion the more wax-like properties the monomers have and less of this monomer is used. Since these high-cut alkyl methacrylates are wax-like, too muchcan cause congealing in the base oil and loss of low temperature fluidity.

:`

.

~ ?'~ '3 - The optirnization of the ratio of the high-, mid- and low-cut alkyl meth-acrylates is dependent on the base oils used in the formulation and the level ofperformance desired. Once the high-cut monomer is optimized then the mid- and low-cut monomer ratios are balanced to give ~ptimum viscosity index and solubility. The balanced formulation will have an alkyl carbon content (Cn) of from about 8 to about 10.
Thus, within the preferred ranges for the various monomers, including the hydroxyalkyl methacrylate and acrylate monorners, and the average number of carbon atoms in the side chain alkyl groups of the backbone polymer, the addition of a polymer of the present in~ention can result in an engine oil formulation exhibiting the viscosit,v and low temperature fluidity properties of an oil a full viscosity grade lo~ver. For example, an SAE 10W-30 oil would meet the pumpability requirements of an SAE 5W-30 oil.
Within these preferred ranges, the polymers of the present invention also provide a lower CCS viscosity while maintaining good low temperature pumpability (measured by MRV) of lubricating oils, thus allowing the use of baseoils having higher viscosities. Consequently, the polymers of the invention allow more extensive use of these heavier base oils in formulated oils, resulting in lower costs, reduced oil consumption and also cleaner engines since these heavier base oils are less volatile than lighter viscosity base oils and reduce piston deposit formation at high operating temperatures, particularly in diesel engines.
In order to achieve the combination of polymer solubility, viscosity index, dispersancy and low temperature properties (such as pour point and cold-crankingengine startup performance) of polymers of the present invention, use levels of low-cut (Cl-C3)alkyl methacrylates, such as methyl methacrylate, may be from zero toabout 25%, typically frorn about 5 to about 15% by weight of the polymer. Polymer solubility refers to the property in which the more hydrophilic or polar monomers, such as those having a low carbon content ~Cl-C3) in the alkyl portion, provide a polymer that is less soluble in the base oils than polymers from the more hydrophobic monomers, such as those having a high carbon content (C4 or greater) :
. . :, - .
-in the alkyl chain. Therefore, if greater than about 10% methyl methacrylate isincorporated into some polymers, depending upon the level of other polar monomers used, e.g., hydroxyalkyl methacrylate, solubility in some base oils may be insufficient for the additive to be fully functional as a dispersant viscosity index improver. On the other hand, if low-cut (C4-C6)alkyl methacrylates are used, such as butyl methacrylate or isobutyl methacrylate, then zero to about 40% by weight, preferably 2Q to 35%, of these monomers may be used to provide an optimum balance of the aforementioned properties, including solubility in the base oils.The weight-average molecular weight (Mw) of the present invention's polymers is not highly critical. It must be sufficient to impart the desired viscosity properties to the lubricating oil. As the weight-average molecular weights of the polymers increase, they become more efficient thickeners; however, they can undergo mechanical degradation in particular applications. Thus, the Mw is ultimately governed by thickening efficiency, cost and the type of application. In general, polymeric lubricating oil additives of the present invention have Mw from about 100,000 to about 1,000,000 (às determined by gel permeation chromatography(GPC), using poly(alkylmethacrylate) standards); preferably, Mw is in the range from about 300,000 to about 800,000 in order to satisfy the particular use application of the oil, e.g., engine oil and automatic transrnission fluid. Weight-average molecular weights of from about 100,000 up to about 300,000 are preferred for hydraulic fluids, gear oils and the like.
Those skilled in the art will recognize that the molecular weights set forth throughout this specification are relative to the methods by which they are determined. For example, molecular weights determined by gel permeation chromatography (GPC) and molecular weights calculated by other methods, may have different values. It is not molecular weight per se but the handling characteristics and performance of a polymeric additive (shear stability and thickening power under use conditions) that is important. Generally, shear stability is inversely proportional to molecular weight and use of a very shear stable additive will require more polymer to obtain good thickening.

- -.

- ' " ~ ~';, , :
.
~': :

.

-The shear stability index (SSI) can be directly correlated to polymer molecular weight and is a measure of the percent loss in polymeric additive-contributed viscosity due to shear and can be deteDned by measuring sonic shear stability according to ASTM D-2603-91 ~published by thle American Society for Testing and Materials). In general, higher molecular weight polymers undergo the greatest relative reduction in molecular weight when subjected to high shear conditions and, therefore, these higher molecular weight polymers also exhibit the largest SSI
values. The SSI range for the polymers of this invention is from about 10 to about 75%, preferably from about 10 to about 25% for low molecular weight polymers andfrom about 30 to about 50% for high molecular weight polymers. The desired SSI
can be achieved by either var,ving the reaction conditions or by mechanically shearing the known molecular weight product polymer.
Representative of the types of shear stability that are observed for lubricatingoil additives of different weight-average molecular weights (Mw~ are the following:
conventional poly(methacrylate) additives having Mw of 130,000, 490,000 and 880,000, respectively, would have SSI values (210F) of 0, 5 and 20%, respectively, based on a 2000 mile road shear test for engine oil formulations; based on a 20,000 mile high speed road test for automatic transmission fluid (ATF) formulations, the SSI values (210F) were 0, 35 and 50%, respectively; and based on a 100 hour ASTM
D-2882-90 pump test for hydraulic fluids, the SSI values (100F) were 18, 68, and 76%, respectively (Effect of Viscosity Index Improver on In-Service Viscosity of Hydraulic Fluids, R.J. Kopko and R.L. Stambaugh, Fuel and Lubricants Meeting, Houston, Texas, June 3-5, 1975, Society of Automotive Engineers).
The polydispersity index of the oil-soluble polymers of the present invention may be from 1.5 to about 15, preferably from 2 to about 4. The polydispersity index ~W/Mn) is a measure of the narrowness of the molecular weight distribution with a minimum value of 1.5 and 2.0 for polymers involving chain termination via combination and disproportionation, respectively, and higher values representingincreasingly broader distributions. It is preferred that the molecular weight :,, - :' ~ :
- : :

~!, ~'S g~ 3 distribution be as narrow as possible, but this is generally limited by the method of manufacture. Some approaches to providing narrow molecular weight distributions (low MW/Mn) may include one or more of the following methods:
anionic polymerization, continuous-feed-stirred-tank-reactor (CFSTR) technology,low-conversion polymeri~ation, control of temperature, etc., during polymerization, mechanical shearing, e.g., homogenization, of the polymer and the like.
Polymers of the present invention having a polydispersity index from 2 to about 4 are preferred because these polymers allow more efficient use of the additive to satisfy a particular formulated engine oil viscosity specification, e.g., about 5 to 10% less additive may be required to produce a viscosity of about 9 to about 20 centipoise (at 100C) in a 100N base oil compared to an additive having a polydispersity index of about 10.
Thus, a fully effective poly~ler additive should provide a balance of shear stability and thickening ability at low usage levels, impart low temperature fluidity without detracting from other properties, such as dispersancy, and be chemicallyneutral to fluoropolymer seals and gaskets. Typically, these performance properties in engine oils, automatic transrnission fluid formulations and the like, were only achieved by mixing two, three or more different additives, i.e., using separate dispersant, viscosity index improver, and pour point depressant additives. The additives of the present invention provide this combination of performance properties in a single polymer.
The polymers of this invention are prepared by mixing monomers (a) and (b) - in the presence of a polymerization initiator, a diluent and optionally a chain transfer agent. The reaction can be run under agitation in an inert atmosphere at a temperature of from about 60 to 140C and more preferably from 115 to 125C.
Typically, the batch will exotherm to the polymerization temperature of 115-120C.
The reaction is run generally for about 4 to 10 hours or until ~e desired degree of polymerization has been reached. As is recognized by those skilled in the art, the time and temperature of the reaction are dependent on the choice of initiator and ''' : ' `'- - ' . ~ .:

. ' ::
~.

can be varied accordingly.
Initiators useful for this polymerizalion are any c)f the well known free-radical-producing compounds such as peroxy, hydroperoxy and azo initiators including acetyl peroxide, benzoyl peroxide, lauroyl peroxide, t-butyl peroxyiso-butyrate, caproyl peroxide, cumene hydroperoxide, 1,1-di(f-butylperoxy)-3,3,5-tri-methylcyclohexane, azobisisobutyronitrile and t-butyl peroctoate. The initiator concentration is normally between 0.025 and 1% by weight based on the total weight of the monomers and more preferably from 0.05 to 0.25%. ~hain transfer agents may also be added to the polymerization reaction to control the molecular weight of the polymer. The preferred chain transfer agents are alkyl mercaptans such as lauryl (dodecyl) mercaptan, and the concentration of chain transfer agent used is from O to about 0.5% by weight.
Among the diluents suitable for the polymerization are aromatic hydrocarbons, such as benzene, toluene, xylene, and aromatic naphthas, chlorinated hydrocarbons such as ethylene dichloride, esters such as ethyl propionate or butyl acetate, and also petroleum oils or synthetic lubricants.
After the polymerization, tXe resultant polymer solution has a polymer content of between about 50 to 95% by weight. The polymer can be isolated and used directly in mineral or synthetic base oils or the polymer and diluent solution can be used in a concentrate form. When used in the concentrate form the polymer concentration can be adjusted to any desirable level with additional diluent (paraffinic base oil). The preferred concentration of polymer in the concentrate is from 30 to 70% by weight. When the concentrate is directly blended into a lubricating base oil, the more preferred diluent is any mineral oil, such as 10û to 150 neutral oil (lOON or 150N oil), which is compatible with the final lubricating base oil.
When a polymer of the present invention is added to lubricating base oils, such as automatic transrr~ission fluids, hydraulic fluids and engine oils, whether it is added as pure polymer or as concentrate, the final concentration of the polymer in the lubricating base oil is from about 0.5 to 15% by weight and more preferably from about 1 to 8%, depending on the specific use application requirements. For example, about 1.5 to about 5% in engine oils, automatic transmission and shock absorber fluids, and up to as much as 10 to 15% in special application gear oils and hydraulic fluids. Lubricating base oils may be either mineral oil types (paraffinic or naphthenic) or synthetic types (polyolefin). The concentration used is dependent on the desired viscometric properties of the lubricating oil and the severity of shear in the intended application; generally, if a low molecular weight polymer is used, a higher concentration is necessary to achieve adequate thickening in the blend and if a high molecular weight polymer is used, a lower concentration can be used in the oil.
The polymers of the present invention were evaluated by a wide variety of performance tests commonly used for lubricating oils and they are discussed below.
Engine oils containing viscosity index improvers generally have viscosity index (VI) values in the range of 120 to about 230, values greater than about 140 being preferred depending upon the blend specifications. The higher the value, the less the change in viscosity as the temperature is raised or lowered. Viscosity index improver compositions of the presen~ invention offer high viscosity index .values (Example 4) while maintaining good dispersancy (Example 5), good cold-cranking engine startup (Example 7) and good chemical neutrality towards fluoropolymer seal materials (Example 6).
Performance characteristics of lubricating oil additives of the present invention were also evaluated for engine cleanliness in the Sequence VE Test, which measures the sludge dispersant characteristics of additives under low and medium temperature operating conditions according to the conditions described inASTM Research Report No. D-2:1002. The engine parts were evaluated and rated at the end of 12 days and cleanliness was rated according to a Coordinating Research Council (CRC) merit system with a value of 10 representing the cleanest engine;
target values for average sludge and for rocker arm cover (RAC~ sludge are greater than 9.00 and 7.00, respectively.
Compositions of the present invention were also subjected to a compatibility - :

2?~
test for fluorohydrocarbon polymers, in particular, vitonTM fluoroelastomers. This test (Engine Seal Compatibility Test, Example 6) was used to evaluate the degree of compatibility of the lubricating oil additives of the present invention with materials used in engine seals, gaskets, etc. The test is based on the immersion of seal or gasket materials in fluids containing candidate lubricating oil additive samples for 7 days, after which their elongation characteristics (percent elongation-at-break or %ELB) were determined. Values of the relative change in %ELB of zero to -5% wererepresentative of neutral conditions, i.e., compatibile with the engine seals.
Compositions of the present invention were subjected to tests designed to measure viscosity performance at low temperatures at low and high shear rates, i.e., according to the SAE J30Q Engine Oil Viscosity Classification, January, 1991. In these circumstances the viscosity of the formulated oil should be low enough to allow sufficient crarlking speed for startup of the engine while providing adequate lubrication of all engine parts.
The Cold-Cranking Simulator (CCS) test estimates the apparent viscosity of engine oils under conditions where engine cranking and startup is mast dif~icultand is based on the procedure defined in ASTM D-5293-92. For example, the CCS
viscosity specification for an SAE 5W-30 grade oil is less than 35 poise at -25C and it is difficult to satisfy this requirement with many of the commercially availableviscosity index improvers.
The mini-rotary viscometer (MRV) test procedure measures low-temperature low-shear performance at engine startup. The MRV test (Example 8) is a measure of the pumpability of an engine oil, i.e., the engine oil must be fluid enough so that it can be pumped to all engine parts after engine startup to provide adequate lubrication. Dispersant viscosity index improvers of the present invention offergood low-temperature performance when forrnulated in a wide range of different base oils.
The following examples are intended to illustrate the inven~on and not to lirnit it, except as it is limited in the claims. All ratios and percentages are by weight, and all reagents are of good commercial quality unless otherwise indicated.

.

2~ ;5 Examples 1 through 3 give synthesis information for preparing polymers of the present invention and Examples 4 through 7 give performance data on oil formulations containing polymers of the invention.

A monomer mix was prepared from 30.0 parts cetyl-eicosyl methacrylate (100% basis, 95% purity), 55.0 parts isodecyl methacrylate (100% basis, 98% purity), 10.0 parts methyl methacrylate, 5.0 parts hydroxypropyl methacrylate, 0.06 partsdodecyl mercaptan, and 0.10 parts 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane.
A heel charge was prepared from 20.0 parts paraffin~c oil base stock (lOON oil) and 0.028 parts 1,1-di(f-butylperoxy)-3,3,~trimethylcyclohexane. The heel charge wasthen charged to a nitrogen flushed kettle fitted with a thermometer and ThermowatchTM to control temperature, a water-cooled reflux condenser with nitrogen outlet, a stirrer, a nitrogen inlet, and an addition furmel to control the addition of the monomer mK. The contents of the flask were heated to 120C and held there. The monomer mix (100 parts) was then added uniformly over a 90 minute period and heating or cooling was applied as needed to maintain the polymerization temperature at 115-120C.
Twenty minutes after the end of the monomer feed, the first of three delayed initiator shots, each containing 0.10 parts of 1,1-di(t-butyl-peroxy)-3,3,5-trimethyl-cydohexane in 10.0 parts paraffinic base oil, were added. The other two initiator shots were added at twenty minute intervals. Twenty minutes after the last initiator addition, about 62 parts of paraffinic base oil was added to bring the batch to a theoretical solids of 50% polymer in oil. Throughout the polymerization, the batch temperature was maintained at 115-120C. Thirty mimltes after the addition of the paraffinic base oil, the batch was homogeneous and the polymerization was considered complete. The conversion of monomer to polymer was about 95% and the polymer had a shear stability index (SSI) of 45 (according to ASTM D-2603-91).

lEXAMPLE 2 The same procedure as Example 1 was followed except the monomer rnix uras 145 parts cetyl-eicosyl methacrylate, 225 parts isodecyl methacrylate, 99 parts butyl methacrylate, 24 parts hydroxypropyl methacrylate and 0.19 parts cumene hydroperoxide. The heel charge was 106 parts paraffinic base oil containing 0.1 gram cumene hydroperoxide and 0.83 parts of 25% tallow-t-octylphenyldimethyl-ammonium chloride in mixed butanols. Also, the three delayed initiator shots were added at 30 minute intervals and each consisted of 0.13 parts of cumene hydroperoxide and 0.83 parts of 25% tallow-t-octylphenyldimethylammonium chloride in mixed butanols in 3.6 parts paraffinic base oil. The batch had a theoretical solids of 52% polymer. The conversion of monomer to polymer was about 93% and the polymer had an SSI of 73.3.

A monomer mix was prepared from 5.0 parts cetyl-eicosyl rnethacrylàte (100%
basis, 95% purity), 85.0 parts isodecyl methacrylate (100% basis, 95% purity), 5.0 parts methyl methacrylate, 5.0 parts hydroxypropyl methacrylate, 0.29 parts dodecyl mercaptan, 0.13 parts t-butyl peroctoate (t-butyl peroxy-2-ethylhexanoate) and 4.9 parts paraffinic base oil (lOON oil). Part of the above monomer mix (40%) was charged to a nitrogen flushed kettle fitted with a thermometer and ThermowatchTMto control temperature, a water-cooled reflux condenser with nitrogen outlet, a stirrer, an nitrogen inlet, and an addition funnel to control the addition of the monomer mix. The contents of the kettle were heated to 105C and allowed to exotherm to 130C before controllirlg by cooling to maintain the temperature below 130C; if the exotherm had not started after about 5 minutes at 105C, the batch was heated slowly to 115-120C until the exotherrn started. When the temperature reached 115C during the exotherm the rernainder of the monomer mix was then added uniformly over a 45 min~te period with cooling to control the exotherm below 125C. The temperature was then maintained at 115-120C for an additional 30 minutes. At this point the first of three delayed initiator shots, each consisting of 0.10 parts t-butyl peroctoate in 9.8 par~s 100N oil, was added to the kettle after which the batch was held at the same temperahlre for 30 minutes. Two additional initiator shots were made at thirty minute intervals. Thirty minutes after the last ad~ition of initiator, approximately 65 parts of 100N base oil was added to dilute the batch to about 50% polymer. The batch temperature was then raised to 130~C and held therefor 30 mi~utes. The final diluted polymer solution had an SSI of 13.2.

Viscosity index (VI) is a measure of the effect of temperature change on the kinematic viscosity of an oil. Viscosity index is expressed as an arbitrary value based on a calculation according to ASTM method D-2270-74 from kinematic viscosity (centistokes) measured at 40C and 100C. Table 1 contains data on viscosity index improvers which have been formulated in two different base oils. Viscosity indeximprover (VII) compositions 1-2 represent poly(alkylmethacrylate) additives of the prior art which contain no hydroxyalkyl methacrylate monomer; VII compositions 3-7 are representative of the present invention based on poly(MMA/IDMA/CIiMA/
HPMA) with relative monomer contents of 9-10/53-56/28-30/4-6 parts by weight, respectively.

Viscosity Index Val~es Formulation 1 Formulation 2 VI I %HPMA 100 40 VI 100 40 VI
0 11.0 57.1 189 10.6 54.9 187 2 0 10.6 55.8 186 10.3 53.6 185 3 4 10.6 53.5 195 10.2 50.5 197 4 4 10.9 54.4 197 10.5 51.5 201 10.4 52.3 195 10.1 49.5 197 6 5 10.7 50.7 211 10.5 51.0 203 7 6 9.8 42.9 192 9.5 46.0 199 ~ -. - . -- ~-:

'; ~.. ', . ' ~ - ;' ? ~

Performance characteristics in the Sequence VE Test (engine cleanliness) of the lubricating oil additives of the present invention are presented in Table 3. The sludge values listed in Table 2 are for the rocker arm cover sludge and the average sludge (target values are greater than 7.0 and 9.0, respectively, with 10.0 representing the cleanest engine). Each of the formulations, M through S, contains 4-8% of the oil additive being tested, 8-10% of a commercial DI package, and 82-87% of a paraffinic base oil. Commercial DI packages typically consisted of an antiwear or antioxidant component, such as zinc dialkyl dithiophosphate; an ashless dispersant, such as polyisobutene based succinimide; a detergent, such as metal phenate or sulfonate; a friction modifier, such as sulfur-containing organic; and an antifoam agent such as silicone fluid: HitecTM 993 is available from Ethyl Corporation and Amoco~9 A-8004 is available from Amoco Chemicals. The oil additives tested were based on poly(MMA/IDMA/CEMA/HPMA) with relative monomer contents of 9-10/53-56/28-30/4-8 parts by weight, respectively. The paraffinic base oils used were Exxon 100N or 150N oils.
The compositions of the various formulations tested were:
M 4.7% additive/8% HitecTM 993 DI package/87% 150N oil N 4.5% additve/8% HitecTM 993 DI package/87% 150N oil 0 6.9% additive/10% Amoco~3' A-8004 DI package/83% 100N oil P 6.7% additive/10% Amoco~ A-8004 DI package/83% 100N oil Q 7.7% additive/10% Amoco~9 A-8004 DI package/82% 100N oil R 6.5% additive/10% Amoco~ A-8004 DI package/83% 100N oil S 4.4% additive/10% Amoco~ A-8004`DI package/78% 100N oil/
7% 150N oil ~'' `~ , ' , .: ' .

? ~ r~

Sequence VE Test (Engine Cleanliness~
% ~PMA in Sludge Formulation Additive (Rocker Arm Cov/Aver) M 5% 9.3/9.4 N 5% 9.3/9.1 O 5% 9.4/9.4 P 5% 9.2/9.4 Q 5% 9.3/9.6 R 4% 8.1/8.0 S 8% 9.4/9.5 Compositions of the present invention were subjected to a compatibility test (Engine Seal Compatibility Test) for fluorohydrocarbon polymers, in particular, VitonTM fluoroelastomers, used in engine seals, gaskets, etc. This test was conducted under conditions sirnilar to those defined in the ISO-37-1977(E) prvcedure (developed by the technical committee of the International Organization for Standardization (ISO/TC45)) using a S3A dumb-bell shaped test specimen.
Evaluation was conducted as follows: in a beaker, three S3A dumb-bell shaped specirnens made of VitonTM fluoroelastomer (AK6) were immersed in the test fluid such that 80 parts of test fluid were present per 1 part of test specimen (volume/volume). The test fluid contained 5% (weight) of the dispersant viscosity index improver composition to be tested together with an appropriate detergent-inhibitor (DI) package at a recommended use level in Exxon 150N oil. The beaker was then covered with a watch glass and placed in a forced-air oven maintained at 149-151C. The test specimens were subjected to the above conditions for 7 days,after which they were removed, allowed to cool and then rinsed lightly with hexane to remove residual test fluid. The test specimens were then air-dried and the tensile strength and elongation characteristics (percent elongation-at-break OI %ELB) were determined using a standard stress-strain measurement procedure at 5.75 .: ' ' - ~ ' ~ :

- - . . .
- .. , .. ;
. . ~ - . ~ .

. ~ . ~ . . . . .

J ~3~
inches/minute elongation rate. The change of elongation of VitonTM elastomer test specimens was then compared to the elongation data from untreated VitonTM
elastomer samples and the result was expressed as a percentage:

[%ELBtreated - %ELBuntreated] X 100 = %ELB Change [%ELBuntrec~ted]

The more negative the value for %ELB Change, the greater the aggressiveness of the test fluid towards the VitonTM fluoroelastomer specimen. Under the test conditions described, fluids resulting in a reduction of more than 45% of the original (untreated) %ELB value (expressed as %ELB Change = -45%) were considered to be very aggressive towards the sample tested and, therefore, incompatible with the YitonTM fluoroelastomer engine seal. Values of %~LB Change of zero to -5% were representative of neutral conditions and, therefore, compatible with the engine seals. Values of %ELB Change of about -20% or less, i.e., more negative, indicated poor seal compatibility. The %ELB results are greatly affected by the rnanner inwhich the equipment is used and it is important to include comparative untreatedsample results with each new set of immersion test samples.
Performance characteristics in the Engine Seal Compatibility Test of the lubricating oil additives of the present invention and those representing commercial nitrogen-containing oil additives are presented in Table 3. Samples of VitonTM fluoroelastomer were immersed in test fluids containing the additives listed. %ELB Change values are expressed as the average for three specimens tested in each fluid. In all cases the test fluids contained 1.5% OLOATM 267 (component of commercial detergent-irlhibitor (DI) package available from Chevron Chemicals).

A-Comparative: Commercial poly(alkyl methacrylate) nitrogen-containing viscosity index improver B-Comparative: Commercial polyolefin nitrogen-containing viscosity index improver - ' ` . , .
.
'- ~ ' ~ . ' .

~? Y 7~

Compositions C through H represent polymeric additives (monomer type and relative parts by weight indicated) of the present invention (MMA is methyl methacrylate, IDMA is isodecyl methacrylate, CEMA is cetyl-eicosyl methacrylate,LMA is lauryl-myristyl methacrylate, HPMA is hydroxypropyl methacrylate):
C MMA/LMA/HEMA (8/88/4) D MMA/IDMA/CEMA/HPMA (10/56/30/4) E MMA/IDMA/CEMA/HPMA (10/56/30/4) F MMA/IDMA/CEMA/HPMA (10/56/29/5) G MMA/IDMA/CEMA/HPMA (10/56/29/5) H MMA/IDMA/CEMA/HPMA (9/53/29/9) ~ngine Se~l Compatibility Te$t Additive Tvpe %ELB Change A-Comparative Nitrogen-containing -47 B-Comparative Nitrogen-containing -39 C 4% HEMA 0 D 4% HPMA -2 E 4% HPMA -1 F 5% HPMA 3 G 5% HPMA -2 H 9% HPMA -3 Performance characteristics in the Cold-Cranking Simulator (CCS) test for the lubricating oil additives of the present invention are presented in Table 4. Blends of the additives to be tested in a base oil were prepared by mixing 2.24% ~active) of the polymer additive and 11.4% of DI package (available from Lubrizol Company as LZ-7838G) with a calculated amount of 100N oil. For example, if the polymer additive is available as 50% solids in 100N oil, then 4.48 parts of the polymer additive oil solution was mixed with 11.4 parts of LZ-7838G and 84.12 parts of 100N
oil to produce the final oil composition to be tested. The CCS viscosity specification for an SAE 5W-30 grade oil is less than 35 poise at -25C.

- - : . , - - . . . :
- ., . . , .. ~ . . -, ~ :
- .

. . ...

- . . .

Cold-Cranlcing Simulal:or (C(:~$) Te~t Polymer Additive Composition CCS Viscosity % MMA % IDMA % CEMA % HPh~A Poise ~ -25~C
0 70 30 0 3~.9 0 65 30 5 34.5 0 60 30 1() 3~L.2 65 30 0 34.0 60 30 5 33.6 55 30 10 32.5 60 30 0 36.0 55 30 5 33.8 50 30 10 33.g Apparent viscosity by mini-rotary viscometer (MRV) was determined by two different test methods and is a measure of engine oil pumpability after cold-engine startup. ASTM D-3829-87 deals with viscosity measurement in the 0 to -40C
temperature range and describes the standard MRV test. ASTM D-4684-89 deals with viscosity measurement in the temperature range of -15 to -30C and describes the TP-1 MRV test. Table 5 contains data for 2 sets of 5 different SAE 5W-30 oilformulations, using 5 different commercial base oils. One set uses a commercial poly(alkylmethacrylate) type nitrogen-containing viscosity index improver and the other set uses a poly(10 MMA/55 IDMA/30 CEMA/5 HPMA) additive composition of the present invention. SAE J300 Engine Oil Viscosity Classification (January 1991) allows a maximum of 300 poise at -30C for SAE 5W-30 oil using the ASTM D-4684-89 test procedure.

.' .' ' . -',: ~ :.
. . .
- . . .. . .

~ ': - : ' MRV_Pumpability Test Source of Viscosity Index $ource of Viscosity at -30C, poise Improver Base Oil TP-1 MRV Std MRV
Commercial A 85.3 74.1 Commercial B 78.4 74.5 Commercial C 72.2 66.1 Commercial . D 64.2 64.2 Commercial E 73.1 71.2 Invention A 86.9 67.8 Invention B 75.7 73.5 Invention C 62.8 63.5 Invention D 60.4 57.2 Invention E 61.2 63.7 A - Solvent-extracted 100N base oil B - Solvent-extracted, solvent dewaxed 100N base oil C - Hydrocracked, catalytically dewaxed 100N base oil D - Solvent extracted, solvent dewaxed 100N base oil E - Solvent extracted, hydrofinished, solvent dewaxed 100N base oil~

. .
- : ~ - ; ' ., , , ~ , . .
~ - . . .

:

Claims (34)

1. A polymer derived from polymerizing monomers comprising:
(a) from about 90 to about 98 weight percent of a monomer selected from the group consisting of (C1-C24)alkyl methacrylates and (C1-C24)alkyl acrylates and (b) from less than 10 to about 2 weight percent of a monomer selected from the group consisting of hydroxy(C2-C6)alkyl methacrylates and hydroxy-(C2-C6)alkyl acrylates, wherein the number of carbon atoms in the alkyl groups averages from about 7 to about 12.
2. The polymer of claim 1 wherein a portion of the total weight of monomers (a) and (b) is from about 5 to about 40 weight percent of (Cl6-C24)alkyl methacrylates, (C16-C24)alkyl acrylates or mixtures thereof.
3. The polymer of claim 1 wherein the number of carbon atoms in the alkyl groups averages from about 8 to about 10.
4. The polymer of claim 3 wherein a portion of the total weight of monomers (a) and (b) is from about 5 to about 35 weight percent of (C16-C20)alkyl methacrylates, (C16-C20)alkyl acrylates or mixtures thereof.
5. The polymer of claim 4 wherein monomer (b) is selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 1-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 1-methyl-2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate and 2-hydroxybutylacrylate.
6. The polymer of claim 1 wherein monomer (a) comprises:
(i) from 0 to about 40% by weight of an alkyl methacrylate or alkylacrylate in which the alkyl group contains from 1 to 6 carbon atoms and mixtures thereof, (ii) from 30 to about 90% by weight of an alkyl methacrylate or alkyl acrylate in which the alkyl group contains from 7 to 15 carbon atoms and mixtures thereof, (iii) from 0 to about 40% by weight of an alkyl methacrylate or alkyl acrylate in which the alkyl group contains from 16 to 24 carbon atoms and mixtures thereof, and monomer (b) comprises from less than 10 to about 2% by weight of a hydroxyalkyl methacrylate or acrylate in which the alkyl group contains from 2 to 6 carbon atoms and is substituted with one or more hydroxyl groups, and mixtures thereof, wherein monomer (b) contains less than about 0.5% by weight of crosslinker or crosslinker precursor materials, and the total of (i), (ii), (iii) and (b) equals 100% by weight of the polymer.
7. The polymer of claim 6 wherein the polymer comprises 0 to about 25% (i), about 45 to about 85% (ii), about 5 to about 35% (iii) and about 4 to about 8% (b).
8. The polymer of claim 6 wherein the average number of carbon atoms is from about 8 to about 10.
9. The polymer of claim 6 wherein monomer (b) is selected from hydroxy-(C2-C6)alkyl methacrylates containing less than about 0.2% by weight of crosslinker or crosslinker precursor materials.
10. The polymer of claim 9 wherein the polymer has a weight-average molecular weight from about 100,000 to about 1,000,000.
11. The polymer of claim 10 wherein the polymer comprises 5 to about 15%
(i), about 50 to about 60% (ii), about 25 to about 35% (iii) and about 5 to about 6% (b).
12. The polymer of claim 10 having a polydispersity index of 1.5 to abput 15.
13. The polymer of claim 11 having a polydispersity index of about 2 to about 4.
14. The polyrner of claim 11 wherein monomer (b) is selected from group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 1-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 1-methyl-2-hydroxyethyl acrylate, 2-hydroxybutyl methacrylate and 2-hydroxybutylacrylate.
15. The polymer of claim 14 wherein monomer (b) is a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate containingless than about 0.1% by weight of crosslinker or crosslinker precursor materials.
16. The polymer of claim 15 wherein (i) is about 10% methyl methacrylate, (ii) is about 55% isodecyl methacrylate, (iii) is about 30% cetyl-eicosyl methacrylate and the amount of (b) is about 5%.
17. The polymer of claim 11 wherein the polymer has a weight-average molecular weight from about 300,000 to about 800,000 and an average number of carbon atoms in the alkyl portion of the acrylate or methacrylate backbone polymer from about 8 to about 10.
18. The polymer of claim 6 wherein (i) is selected from one or more of the group consisting of methyl methacrylate, butyl methacrylate and isobutyl meth-acrylate, (ii) is selected from one or more of the group consisting of 2-ethylhexyl methacrylate, isodecyl methacrylate, dodecyl-pentadecyl methacrylate and lauryl-myristyl methacrylate, (iii) is selected from one or more of the group consisting of cetyl-stearyl methacrylate and cetyl-eicosyl methacrylate, and (b) is selected from one or more of the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 1-methyl-2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 1-methyl-2-hydroxyethyl acrylate, 2-hydroxybutyl meth-acrylate and 2-hydroxybutyl acrylate.
19. The polymer of claim 18 wherein the polymer has a weight-average molecular weight from about 100,000 to about 1,000,000.
20. The polymer of claim 18 wherein (i) is about 10% methyl methacrylate, (ii) is about 55% isodecyl methacrylate, (iii) is about 30% cetyl-stearyl methacrylate and (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
21. The polymer of claim 18 wherein (i) is about 20% butyl methacrylate, (ii) is about 45% isodecyl methacrylate, (iii) is about 30% of a monomer selected from the group consisting of cetyl-stearyl methacrylate and cetyl-eicosyl methacrylate and (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
22. The polymer of claim 18 wherein (i) is about 20% isobutyl methacrylate, (ii) is about 45% isodecyl methacrylate, (iii) is about 30% of a monomer selected from the group consisting of cetyl-stearyl methacrylate and cetyl-eicosyl methacrylate, and (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate.
23. The polymer of claim 18 wherein (i) is about 15% of a monomer selected from the group consisting of butyl methacrylate and isobutyl methacrylate, (ii) is about 80% of a monomer selected from the group consisting of lauryl-myristyl methacrylate and dodecyl-pentadecyl methacrylate, the amount of (iii) is 0% and (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxy-ethyl methacrylate.
24. The polymer of daim 18 wherein (i) is from about 5 to about 10% methyl methacrylate, (ii) is from about 85 to about 90% of a monomer selected from the group consisting of lauryl-myristyl methacrylate, isodecyl methacrylate and dodecyl-pentadecyl methacrylate, (iii) is zero to about 5% cetyl-eicosyl methacrylate and (b) is about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxy-ethyl methacrylate.
25. A concentrate for use in lubricating oils comprising between about 30 to 70% by weight of the polymer of claim 1.
26. A concentrate for use in lubricating oils comprising between about 30 to 70% by weight of the polymer of claim 6.
27. The concentrate of claim 26 wherein the polymer comprises about 10%
methyl methacrylate, about 55% isodecyl methacryalate, about 30% cetyl-eicosyl methacrylate, about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate and has a weight-average molecular weight from about100,000 to about 1,000,000.
28. A lubricating oil composition comprising a lubricating oil and between about 0.5 and 15% by weight of the polymer of claim 1.
29 29. A lubricating oil composition comprising a lubricating oil and between about 0.5 and 15% by weight of the polymer of claim 6.
30. The lubricating oil composition of claim 29 wherein the polymer comprises about 10% methyl methacrylate, about 55% isodecyl methacrylate, about 30% cetyl-eicosyl methacrylate, about 5% of a mixture of 2-hydroxypropyl meth-acrylate and 1-methyl-2-hydroxyethyl methacrylate and has a weight-average molecular weight from about 100,000 to about 1,000,000.
31. An automatic transmission fluid comprising between about 1 to 8% by weight of the polymer of claim 1.
32. An automatic transmission fluid comprising between about 1 to 8% by weight of the polymer of claim 6.
33. The automatic transmission fluid of claim 32 wherein the polymer comprises 0 to about 5% methyl methacrylate, about 80 to about 90% lauryl-myristyl methacrylate, 0 to about 10% cetyl-eicosyl methacrylate, about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate and has a weight-average molecular weight from about 100,000 to about 1,000,000.
34. The automatic transmission fluid of claim 32 wherein the polymer comprises 0 to about 20% butyl methacrylate, about 65 to about 90% lauryl-myristyl methacrylate, 0 to about 10% cetyl-eicosyl methacrylate, about 5% of a mixture of 2-hydroxypropyl methacrylate and 1-methyl-2-hydroxyethyl methacrylate and has a weight-average molecular weight from about 100,000 to about 1,000,000.
CA002077835A 1992-03-20 1992-09-09 Dispersant polymethacrylate viscosity index improvers Abandoned CA2077835A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US85492492A 1992-03-20 1992-03-20
US854,924 1992-03-20
US90993192A 1992-07-07 1992-07-07
US909,931 1992-07-07

Publications (1)

Publication Number Publication Date
CA2077835A1 true CA2077835A1 (en) 1993-09-21

Family

ID=27127266

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002077835A Abandoned CA2077835A1 (en) 1992-03-20 1992-09-09 Dispersant polymethacrylate viscosity index improvers

Country Status (15)

Country Link
EP (1) EP0569639A1 (en)
JP (1) JPH05287028A (en)
AU (1) AU662159B2 (en)
BR (1) BR9203648A (en)
CA (1) CA2077835A1 (en)
CZ (1) CZ284692A3 (en)
FI (1) FI923809A (en)
HU (1) HUT72025A (en)
LV (1) LV10295A (en)
MA (1) MA22828A1 (en)
NO (1) NO923342L (en)
NZ (1) NZ244082A (en)
PL (1) PL295889A1 (en)
SI (1) SI9200219A (en)
TN (1) TNSN93031A1 (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2726828A1 (en) * 1994-11-10 1996-05-15 Rohm & Haas France DISPERSING ADDITIVES IMPROVING THE VISCOSITY INDEX FOR LUBRICATING OILS
US5807409A (en) * 1996-10-30 1998-09-15 Rohm And Haas Company Method of improving pull-up characteristic of leather substrate and modified finishing oil used therein
US7101928B1 (en) * 1999-09-17 2006-09-05 Landec Corporation Polymeric thickeners for oil-containing compositions
JP5565999B2 (en) * 2007-01-31 2014-08-06 Jx日鉱日石エネルギー株式会社 Lubricating oil composition
EP2439259A4 (en) * 2009-06-04 2014-03-12 Jx Nippon Oil & Energy Corp Lubricant oil composition
JP5606011B2 (en) * 2009-06-09 2014-10-15 昭和シェル石油株式会社 Lubricant
JP5584049B2 (en) * 2010-08-17 2014-09-03 株式会社Adeka Extreme pressure agent for lubricating oil and lubricating oil composition containing the same
WO2014017555A1 (en) * 2012-07-24 2014-01-30 Jx日鉱日石エネルギー株式会社 Poly(meth)acrylate-based viscosity index improver, lubricant additive and lubricant composition containing viscosity index improver
EP3320063B1 (en) * 2015-07-10 2022-09-14 The Lubrizol Corporation Viscosity modifiers for improved fluoroelastomer seal performance
EP3497190B1 (en) 2016-08-15 2020-07-15 Evonik Operations GmbH Functional polyalkyl (meth)acrylates with enhanced demulsibility performance
JP6975169B2 (en) * 2016-11-30 2021-12-01 株式会社クラレ Method for producing methacrylic copolymer solution
JP7068010B2 (en) * 2017-04-07 2022-05-16 三洋化成工業株式会社 Viscosity index improver and lubricating oil composition
US10351792B2 (en) 2017-05-09 2019-07-16 Afton Chemical Corporation Poly (meth)acrylate with improved viscosity index for lubricant additive application
US9988590B1 (en) 2017-11-10 2018-06-05 Afton Chemical Corporation Polydialkylsiloxane poly (meth)acrylate brush polymers for lubricant additive application
WO2019096593A1 (en) * 2017-11-15 2019-05-23 Evonik Degussa Gmbh Functionalized polymers
CN111406101A (en) * 2017-12-05 2020-07-10 株式会社Adeka Friction inhibiting compounds and friction inhibiting compositions containing the same
US10144900B1 (en) 2018-02-02 2018-12-04 Afton Chemical Corporation Poly (meth)acrylate star polymers for lubricant additive applications
CN112876625B (en) * 2020-11-30 2022-09-06 大连同康新材料科技有限公司 Poly (methyl) acrylate viscosity index improver and preparation method and application thereof
CN116333789A (en) * 2023-03-06 2023-06-27 上海应用技术大学 Binary polymer biodiesel pour point depressant and preparation method thereof

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198739A (en) * 1960-11-25 1965-08-03 Shell Oil Co Lubricants and polymeric additives therefor
NL276299A (en) * 1962-03-23
US3311597A (en) * 1962-08-31 1967-03-28 Monsanto Co Oil additives comprising interpolymers of tetrahydrofurfuryl esters
NL127451C (en) * 1962-11-13
GB1132604A (en) * 1965-05-07 1968-11-06 Shell Int Research Improvements in or relating to polymer concentrates
NL134235C (en) * 1968-04-26
GB1189281A (en) * 1969-01-01 1970-04-22 Shell Int Research Copolymers containing Free Hydroxyl Groups
NL6917635A (en) * 1969-11-21 1971-05-25
DE3930142A1 (en) * 1989-09-09 1991-03-21 Roehm Gmbh DISPERGING VISCOSITY INDEX IMPROVERS
DE4000753A1 (en) * 1990-01-12 1991-07-18 Roehm Gmbh POWER TRANSFER FLUID BASED ON MINERAL OIL

Also Published As

Publication number Publication date
BR9203648A (en) 1993-09-28
TNSN93031A1 (en) 1994-03-17
NO923342D0 (en) 1992-08-27
AU2127392A (en) 1993-09-23
SI9200219A (en) 1994-03-31
JPH05287028A (en) 1993-11-02
AU662159B2 (en) 1995-08-24
NO923342L (en) 1993-09-21
PL295889A1 (en) 1993-10-04
NZ244082A (en) 1995-01-27
FI923809A0 (en) 1992-08-25
CZ284692A3 (en) 1994-02-16
MA22828A1 (en) 1993-10-01
LV10295A (en) 1994-10-20
FI923809A (en) 1993-09-21
EP0569639A1 (en) 1993-11-18
HUT72025A (en) 1996-03-28

Similar Documents

Publication Publication Date Title
AU663360B2 (en) Ashless dispersant poly(meth)acrylate polymers
AU662159B2 (en) Dispersant poly(meth)acrylate viscosity index improvers
CA2357474C (en) Dispersant (meth) acrylate copolymers having excellent low temperature properties
CA2276900C (en) (meth)acrylate copolymers having excellent low temperature properties
EP1777285B1 (en) Additive composition
CA2448520C (en) Alkyl (meth) acrylate copolymers
US5622924A (en) Viscosity index improver and lubricating oil
RU2749905C2 (en) Functional groups containing polyalkyl (meth) acrylates with improved demulsifying ability
JP2009120853A (en) Lubricant containing olefin copolymer and acrylate copolymer
US5726136A (en) Multifunctional additive for lubricating oils compatible with fluoroelastomers
EP0561335B1 (en) Lubricating oil viscosity index improver composition
JP2005508397A (en) Carboxylate-vinyl ester copolymer blend compositions for improving the fluidity of lubricating oils
JP7123900B2 (en) Defoamer and lubricating oil composition
Stambaugh et al. Viscosity index improvers and thickeners
EP0329756B1 (en) Methacrylate pour point depressants and compositions
CA2162552C (en) Dispersant viscosity index improving additive for lubricating oils
JP2754340B2 (en) Viscosity index improver
JP2906024B2 (en) Lubricant
JP2007514048A (en) Additive composition for transmission oil

Legal Events

Date Code Title Description
FZDE Discontinued