Title of Invention

"A METHOD OF PREPARING A GRAFT POLYALKENE DISPERSANT"

Abstract A polyalkene dispersant comprised of low MW polyalkene having art average molecular weight range of about 300 to about 10,000 and an ethyienically-unsaturated, aliphatic or aromatic, nitrogen- and oxygen-containing graftable monomer and methods of making the same are disclosed. The monomers are formed by reacting an acylating agent with amines having one or more primary or secondary amine to form a reaction product Graft polyalkene dispersants comprising such monomers are formed by grafting the reaction product to the polyalkene backbone. Also described is lubricating oil comprising base oil and the dispersant polyalkene as described above.
Full Text PREPARATION OF FUNCTIONAL MONOMERS FOR GRAFTING TO LOW
MOLECULAR WEIGHT POLYALKENES AND THEIR USE IN THE PREPARATION
OF DISPERSANTS AND LUBRICATING OIL COMPOSITIONS CONTAINING
DISPERSANT POLYALKENES
This application claims the benefit of Provisional Patent Application No. 60/523,959. filed on November 21,2003.
OBJECTS OF THE INVENTION
The present invention relates to novel functional monomers and dispersant polyalkenes comprising such monomers.
The present invention further relates to low MW polyalkene backbones which have been grafted with ethytenically unsaturated, aliphatic or aromatic mono-, bi~ and multi-functional monomer mixtures containing oxygen and nftrogen atoms.
The present invention further relates to methods for manufacturing these novel monomers and the drspersant graft polyalkenes comprising such monomers.
The present invention further relates to lubricating oil compositions containing the dispersant graft polyalkenes in amounts effective to function as dispersants and potentially as low MW viscosity index improvers.
It is also contemplated that the molar proportions of the grafted mono, bi and multi-functional monomer to low MW polyalkene ratio may be 0.2:1. 0.5:1,1:1. 2:1,4:1 and as much as 8:1 of grafted monomer: moles polyalkene backbone.
SUMMARY OF THE INVENTION
The present invention provides novel monomers and methods of making such monomers. Such monomers may be used to prepare dispersants or dispersant viscosity index improvers (DVIIs). One aspect of the invention is the. preparation of a reaction product comprising one or more ethylenically unsaturated, aliphatic or aromatic monomers having nitrogen and oxygen atoms. For example, the reaction product obtained by reacting maleic anhydride and Methylene tetramine. The reaction product is a mixture that contains, among other components, the mono-maleimide and corresponding amic acid of Methylene tetramine as well as the di-mafeimide and corresponding di-amic acid of Methylene tetramine. The graftable compounds of the reaction product are then grafted onto the low MW polyalkene using free radical initiators.
The term "reaction product" as used in this specification refers to one or more compounds formed by the reaction of one, two or more reactants. Thus, it may include more than one chemical compound formed from the combination of the acylating agent and the amine, and in such instances, the term "reaction product" will be understood to refer to all such chemical compounds. The term "monomer" as used in this specification refers to the graftable. ethylenically unsaturated, aliphatic or aromatic nitrogen- and oxygen-containing compound(s) of the reaction product. The monomers may be mono-, bi-or multifunctional The graftable monomers) may, but need not, be recovered from the product mixture before carrying out the grafting reaction. The present method may also comprise the step of recovering one or more graftable compounds from the reaction product of the acylating agent and the amine.
Another aspect of the invention is the graft reaction product of a low MW polyalkene with an ethylenically unsaturated, aliphatic or aromatic mono-, bi- or multifunctional monomer having from 3 to about SO carbon atoms in addition to nitrogen and oxygen atoms. The graft reaction product has a molar proportion of grafted monomer to polyalkene ratio of at least about 0.2:1, alternatively at least about 0.5:1, alternatively at least about 1:1, alternatively at least about 2:1, about 4:1, and as much as about 8:1.
Another aspect of the invention is a method of making a dispersant or low MW viscosity index improver. According to this invention, a graftable monomer and a low MW polyalkene are provided. In some embodiments the low MW polyalkene has pendant unsaturated sites for grafting. Sufficient initiator is provided to graft the graftable monomer to the polyalkene. in some embodiments, grafting of the monomer onto the polyalkene backbone is carried out after reacting the low MW polyalkene with chlorine. In some embodiments, grafting of the monomer mixture onto the polyalkene backbone is carried using the "ene" reaction.
Another aspect of this invention is the grafting of an ethylenically-unsaturated, aliphatic or aromatic, hydrocarbon monomer containing both nitrogen and oxygen atoms onto a low MW polyalkene to form a dispersant moiety. To meet the objectives of the invention, it is preferable to react the polyalkene so that it contains at least about 0.2 mole of monomer per mole of polyalkene, or alternatively, 0.5 mole of monomer per mole, of polyalkene or, alternatively, 1 mole of monomer per mole of polyalkene or, alternatively, 2 moles of monomer per mole of polyalkene or,
alternatively, 4 moles of monomer per mole of polyalkene or, alternatively, as much as 8 moles of monomer per mole of polyalkene, though the ratio is not critical for all aspects of the invention. The low MW polyalkene of the present invention (hereinafter alternatively referred to as the polyalkene or the low MW polyalkene) has a number average molecular weight of from about 300 to about 10000, preferably from about 600 to about 8000, or preferably from about 900 to about 5000 or more preferably from about 900 to about 4000. Particularly useful polyalkenes have number average molecular weights from about 1100 to about 3000.
In carrying out the reaction, the polyalkene may be reacted as a neat material or dissolved in a solvent forming a solution. The graftable monomer and an initiator are added to the polyalkene. The graftable monomer and/or the initiator can be added gradually to the polyalkene or they can be added together or introduced successively or introduced as aliquots of reactants. The rate of addition of the graftable monomer can be from 0.1 % to 100% of the entire charge of monomer per minute. The rate of addition of the initiator can be from about 0.1 % to about 100% of the initiator charge per minute. The reaction temperature is maintained at a level which gives rise to a satisfactory reaction initiation rate. In one embodiment, the graftable monomer and the initiator are each added at a uniform, relatively slow rate during the reaction.
The resulting graft polyalkene may have a monomer to polyalkene ratio of at least about 0.2:1, alternatively at least about 0.5:1, alternatively at least about 0.8:1, alternatively at least about 1:1, alternatively at least about 2:1, about 4:1, about 8:1, or even higher ratios.
In principle, the graft product from the polyalkene may be made by melt-blending and reacting a mixture consisting essentially of the graftable monomer mixture; a low MW polyalkene; and an initiator. The reaction is carried out at a temperature and under conditions effective to graft the monomer mixture onto the polyalkene. The graft reaction product under such circumstances exhibits a monomer to polymer ratio of at least about 02:1, alternatively at least about, 0.5:1 alternatively at least about 0.8:1, alternatively at least about 1:1, alternatively at least about 2:1, about 4:1, and as much as about 8:1, or possibly higher ratios.
Another aspect of the invention is lubricating oil comprising a hydrocarbon base oil and a grafted polyalkene as described above. The grafted polyalkene functions as a dispersant or as a dispersant with viscosity enhancing properties. The dispersant may
be used in an amount which is from about 0.05% to 20% by weight solids of a lubricating oil composition.
DETAILED DESCRIPTION OF THE INVENTION
While the invention will be described in connection with one or mere preferred embodiments, it will be understood that the invention is not limited to those embodiments. The invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the claims concluding this specification.
The novel bi- or multi- functional monomers according to the present invention are obtained by reacting acylating agents, such as maleic anhydride, with amines having more than, one primary or secondary amine, such as Methylene tetrarnine. Mono-functional monomers are obtained, for example, by reacting maleic anhydride with amines having only one primary or secondary amine such as 4-aminodiphenylamine. For a more complete description of amines used to prepare mono-functional monomers see U.S. Patent Application No. 10/444,548 which is incorporated herein by reference.
The novel graft polyalkene (also referred to herein as dispersant polyalkene) according to the present Invention is made by reacting a tow MW polyalkene with a polar, ethylenically unsaturated, preferably nitrogen- and oxygen-containing, preferably heterocyclic and aromatic graftable monomer, in the presence of an initiator. The reaction may be carried out with either neat polyalkene, polyalkene dissolved in solvent, or neat polyalkene in melt form using an extrusion reactor.
In the following paragraphs are examples of reactants used in the preparation of (a) the bi-functional and higher graftable monomer mixtures, (b) grafted poiyaikenes to form dispersants, and (c) lubricating oil compositions. Also, in the following examples are descriptions of the poryatkenes, acylating agents, amines, initiators, and solvents contemplated for use herein to make the bi-functional and higher graftable monomer mixtures and dispersants from poiyaikenes.
J. Materials and Methods for Preparation of Bi-Functional and Higher Graftable Monomer Mixtures
A. Solvents for Use in The Preparation of Bj-Functional and Higher Graftable Monomer Mixtures
Useful solvents include volatile solvents which are readily removable from the monomer after the reaction is complete or ones which are not readily volatilized and removed after completion of the reaction- Any solvent may be used which can disperse or dissolve the reaction product and may be handled in such a way as not to participate appreciably in the reaction or cause side reactions to a material degree or interfere with subsequent processes which utilize the graftable monomer mixture. Several examples of solvents of this type include straight chain or branched chain aliphatic or alicyclic hydrocarbons, such as n-pentane, n-heptane, i-heptane, n-octane, i-octane, nonane, decane, cycfohexane, dihydronaphthalene, decahydranaphthalene, and relatively volatile aromaties such as toluene, xylene, and ethyibenzene and others not listed. Nonreactive halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, dichlorotoluene and others are also useful as solvents. Aliphatic or aromatic ketones, ethers, esters, formamides, carbonates, water etc, are also contemplated as solvents herein. Also contemplated are mixtures of solvents.
Examples of the ketones, ethers, esters, formamides, carbonates, etc. which are contemplated include, but are not limited to, acetone, methylethyl ketone, diethyl ketone, N.N-dimethylformamide. N,N-diethylforrnamide, N,N-dimethylacetamide, N-methyl pyrrolidone, diethyl carbonate, propylene carbonate, diethyl ether, dimethyl ether, isopropyl ether, 2-metnoxyethyl ether, dioxane, dimethyl sulfoxide, butyl acetate, ethyl acetate, and dimethyl malonate.
The solvents useful here also include base oils or base stocks, as defined in ASTM D 6074-99, "Standard Guide for Characterizing Hydrocarbon Lubricant Base Oils" which may be suitable for incorporation into a final lubricating oil product Any base oil may be used which can disperse or dissolve the reaction product without materially participating in the reaction or causing side reactions to an unacceptable degree. For example, solvent dewaxed and hydrocracked base oils, paraffin and isoparaffin fluids, base oils which contain low or moderate levels of aromatic constituents, and fluid poly-α-olefins are contemplated for use herein. The use of
base oils having aromatic constituents, white being less than optimum in some instances, is contemplated under this disclosure.
B. Acyiating Agents for Use In The Preparation of Bi-Functional and Higher Graftable Monomer Mixtures
In this specification, the terms olefinic unsaturation and ethyfenic unsaturation are used interchangeably. The acyiating agent has at feast one point of olefinic unsaturation (in other words, C=C) in its structure. Usually, the point of olefinic unsaturation will correspond to -HOCH- or-HC=CH2. Acyiating agents where the point of olefinic unsaturation is α, ß to a carboxy functional group are very useful. Oleffnically unsaturated mono-, di- and polycarboxylic acids, the lower alkyl esters thereof, the halides thereof. and the anhydrides thereof represent typical acyiating; agents in accordance with the present invention. Preferably, the olefinically unsaturated acyiating agent is a mono- or dibasic acid, or a derivative thereof such as anhydrides, tower alkyl esters, halides and mixtures of two or more such derivatives. "Lower alky!" means alkyl groups of one to seven carbon atoms.
The acyiating agent may include at least one member selected from the group consisting of monaurtsaturated C4 to C50. alternatively C4 to C20, alternatively C4 to C10, dicarboxylic acids monounsaturated C3 to-C50, alternatively C3 to C20, alternatively C3 to C10, monocarboxytic acids and anhydrides thereof (that is, anhydrides of those carboxylic acids or of those monocarboxylic acids), and combinations of any of the foregoing (that is, two or more of those acids and/or anhydrides).
Suitable acyiating agents include acrylic acid, crotonic acid, methacryiic acid* maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, ctfraconvc add, citraconic anhydride, mesaconic acid, glutaconlc acid, chloromaleic acid, aconitic acid, methyforotonic acid, sorbie acid, 3-hexenoic acid, 10-decenoic ackl, 2-pentene-1,3,5-tricarboxylic acid, clnnamic add. and lower alkyl (e.g., C1 to C4 alkyl) acid esters of the foregoing, e.g„ methyl maleate, ethyl fumarate. methyl fumarate, etc, Particularly preferred are the unsaturated djcarboxyfic acids and their derivatives; especially maleic acid, fumaric acid and maleic anhydride.
C. Amines for Use In the Preparation of Bi-Functional and Higher Graftable Monomer Mixtures
The amines must be capable of being acylated by the appropriate acyfating agent, namely primary or secondary amines. Amines capable of being acylated are disclosed in U.S. Patent No. 4,320.019, column 4, line 60 to column 6, line 14; U.S. Patent No. 5,424,367, column 10, line 61 to column 13, line 18; U.S. Patent No. 5,427,702, column 13, line 5 to column 17, line 32. Each of these disclosures is hereby incorporated by reference herein.
Among the various amine types useful in the practice of this invention are alkylene polyamines, aromatic polyamines, and polyoxyalkylene polyamines.
Some examples of the alkylene polyamines include methyleneamlnes, ethyleneamines, butyleneamines, propyleneamines, pentyieneamines, hexyiene-amines, heptyleneamines, octyleneamines, other polymethvleneamines, the cyclic and higher homologs of these amines such as the piperazines, the amino-alkyl-substituted piperazines, etc. The amines include, for example, ethyfene diamine, dlethylene triamine, trieihyiene tetramine, propylene diamine, difhepta-methylene)triam?ne, tripropyiene tetramine, tetraethylene pentamine, trimethytene diamine, pentaethylene. hexamine, di(trimethylene)triamine, diaminocyciohexane, diaminopropane, diaminobutane, triaminocyclohexane, as well as other polyaminic materials. Other higher homologs obtained by condensing two or more of the above-mentioned alkyieneamines may be used.
Examples of suitable polyoxyalkyfene polyamines are those which have the formulae:
(i) NH2(-alkylene-O-alkylene)mNH2-where m has a value of about 3 to 70 and preferably 10 to 35; and
(ii) R-(alkylene(-O-alkylene)nNH2)3-6 where n has a value of about 1 to 40 with the provision that the sum of all the n's is from about 3 to about 70 and preferably from about 6 to about 35 and R is a polyvalent saturated hydrocarbon radical of up to ten carbon atoms. The alkylene groups in either formula (i) or (ii) may be straight or branched chains containing about 2 to 7, and preferably about 2 to 4 carbon atoms.
The polyoxyalkylene polyamines, such as polyoxyalkyfene diamines and polyoxyalkyfene triamines, may have average molecular weights ranging from about
200 to about 4000 and preferably from about 400 to about 2000. Suitable poiyoxyalkylene polyamines include the polyoxyethylene and polyoxypropylene diamines and the polyoxypropylene triamines having average molecular weights ranging from about 200 to 2000.
Other amine types useful in the practice of this invention include aromatic amines such as benzyl amine and 3-phenyl-1-propyl amine as well as amino-aromatic compounds such as N-arylphenylenediamines represented by the formula:
(Formula Removed)
in which Ar is aromatic and R1 is hydrogen, —NH-aryl, -NH-arylalkyl, -NH-alkylaryl, or a branched or straight chain radical having from 4 to 24 carbon atoms and the radical can be an alkyl, alkenyl, alkoxyl, arylalkyl, atkylaryl, hydroxyalkyl or aminoalkyl radical, Ra is -NH2t -(NH(CH2)n-)m-NH2, CH2-(CH2)n-NH2, -aryl-NH2 in which n and m has a value from 1 to 10, and Ra is hydrogen or an alkyl, alkenyl. alkoxyl, arylalkyl.or alkyteryl radical, which may have from 4 to 24 carbon atoms.
Suitable N-arylphenylenediamine compounds may also be represented by the formula:
(Formula Removed)
in which R4 R5 and R6 are hydrogen or a linear or branched hydrocarbon radical containing from 1 to 10 carton atoms and that radical may be an alkyl, alkenyl, alkoxyl, alkylaryl, arylalkyl, hydroxyalkyl, or aminoalkyl radical, and R4. R5 and R6 can be the same or different
Particularly preferred N-aiylphenylenediamines are the N-phenylphenylene-diamines. for example, N-henyl-1,4-phenylenediamine (also referred to herein as 4- aminodiphenyiamine), N-phenyl-1,3-prienylenediarnine, N-phenyl-1,2-phenylene-diamine, N-naphthyl-prienylenediamine, N-phenylnaphthalenediamine and N-arnino-propyl-N-phenylphenylenedlamine. Most preferably, the amine Is 4-amino-diphenyiamine (also called N-phenyl-1,4-phenylenediamine).
Other useful amine types include aminocarbazoles such as those represented by the formula:
(Formula Removed)
in which R7 and R8 represent hydrogen or an alkyl, alkenyl, or alkoxyl radical having from 1 to 14 carbon atoms, and R7 and R8 can be the same or different; aminoindoles such as those represented by the formula:
(Formula Removed)
in which Rs represents hydrogen or an alkyl radical having from 1 to 14 carbon
atoms,
amino-indazolinones such as those represented by the formula:
(Formula Removed)
In which R10 is hydrogen or an alkyl radical having from 1 to 14 carbon atoms, amino-mercaptotrizole as represented by the formula:
(Formula Removed)
aminoperimidines such as those represented by the formula:
(Formula Removed)
in which R1f represents hydrogen or an alkyl or alkoxyl radical having from 1 to 14 carbon atoms.
Other- useful amines include: 2-fieptyl-3-(2-aminopropyl)imidazoline, 4-methylimidazoline, 1,3-bis-(2-aminoethyl)imidazoline, (2-aminopropyl)-piperazine. 1,4-bis-(2-aminoethyI)piperzine, N,N-dimethyaminopropyl amine, N,N-dictylethyl amine, N-octyl-N'-methylethylene diamine, and 2-methyl-1(2-aminobutyl) piperazine, and aminothiazoles from the group consisting of aminothiazole, aminobenzothiazole, aminobenzothiadiazole and aminoalkylthiazole, and aminopyrimidines, such as 2,4,6-triamlnopyrimidine.
It is also contemplated that combinations of the above amines may be used to react with one or more acylating agents.
The choice of amine compound will depend, In part, upon the nature of the acyteting agent in the case of the preferred acylating agent, maleic anhydride, those that will react advantageously with the anhydride functionality are most preferred and, therefore, appropriate. Primary amines are preferred because of the stability of the imida products formed. Primary amines, structurally described as RNH2. may be used in which the R group may contain performance enhancing functionalities desirable for the final product Such properties may Include, among others, wear protection, friction reduction and protection against oxidation, incorporation of elements in addition to carbon, hydrogen and nitrogen, such as, but not limited to, the halogens or sulfur or oxygen, either alone or in combination, is also contemplated.
D. Method for Preparation of Bi-Functional and Higher Graftable Monomer Mixtures
A novel method is provided herein of making a bi-functional ethylenically unsaturated, aliphatic or aromatic, nitrogen- and oxygen-containing, graftable monomer, suitable for grafting to a polyaikene to form a dfspersant The method comprises the step of forming an acylating agent mixture comprising a solvent and an acylating agent having at least one point of olefmic unsaturate The acylating agent may be dissolved or dispersed in the solvent, and the acylating agent mixture may be a solution or dispersion. Suitable solvents include oxygenates such as acetone, base oils, and amies such as N,N-dimethyl formamide. The method also comprises the step of adding a dt-amine or higher to the acylating agent mixture, thereby forming a mixture. The dt-amine or higher may be added to the acylating agent alt at once or stowly, for example, by adding aliquots or metering over a period of time- "Metering" means to add, by drops or continuously, a specific amount over a certain time. The method may comprise the simultaneous metering of the acylating agent and the diamine Into the solvent or premixing the acylating agent and the di-amine prior to mixing the reactaats with solvent The method also comprises the step of heattng the mixture. The acylating agent and/or the amine may be heated before, during or after they are combined. The method forms a reaction product of the acytating agent and the amine. The monomer may or may not be recovered from the reaction product
before carrying out the grafting reaction. The present methods may also comprise the step of recovering one or more graftabie components from the reaction product of. the acylating agent and the amine.
The acylating agent and the amine may be provided in suitable molar ratios, though such ratios are not critical for ali aspects of the invention. Suitable molar ratios of di-amine to acylating agent include, but are not limited to, the ranges of from about 0.1:1 to about 4:1, from about 0.2:1 to about 4:1. from about 0.5:1 to about 4:1, and from about 1:1 to about 4:1. Where the acylating agents are maleic acid or maleic anhydride, the preferred molar ratios are in the range of from about 0.5:1 to about 3:1.
II. Materials and Methods for Preparation Of Dispersant Polyalkenes
A. Polyalkenes for Use In The Preparation Of Dispersant Polyalkenes
A wide variety of polyalkenes (which may or may not have pendant unsaturation) are contemplated for use as a backbone for grafting. Examples of polyalkene contemplated for use include olefin homopolymers, copolymers, and terpolymers, such as, but not limited to, polyethylene, polypropylene, ethylene-propylene polyalkenes, polymers containing two or more monomers, polyisobutene, polymeihacrylates, polyalkylstyrenes, partially hydrogenated poiyolefins of butadiene and styrene and copolymers of isoprene, such as polymers of styrene and isoprene. EPDM (ethylene/propytene/diene monomer) polymers, such as ethylene-propylene ENB terpolymers, are also contemplated for use.
Materials contemplated .for use herein also include ethylene/propylene/diene poiyolefins containing from about 16% to about 90% ethylene and from about 10% to about 85% propylene moieties by number, or alternatively, from 30% to about 75% ethylene and from about 25% to about 70% propylene moieties by number. These materials may be optionally modified with from 0% to about 9% diene monomers. Useful diene monomers include 1,4-hexadiene, dicydopentadiene, 2, 5-norbomadiene. 5-ethylidene-2-norbomene, and 1-alkyl-4-isopraoylidene cyclohexane and combinations of two or more diene monomers.
The tow MW polyalkene has a number average molecular weight of from about 300 to about 10,000, preferably from about 500 to about 8,000, or preferably from about 900 to about 5000 or more preferably from about 900 to about 4000.
Particularly useful low MW polyalkenes have number average molecular weights from about 1100 to about 3000.
B. Monomers for Use in the Preparation of Dfspersant Polyalkenes
The monomers contemplated for use in the preparation of the dlspersant polyalkenes include ethytenically unsaturated, aliphatic or aromatic mono-functional monomers described In U.S. Patent Application No. 10/444,548 discussed above as well as an ethytenically unsaturated, aliphatic or aromatic bi-functional and higher monomers as described in this disclosure.
C. Initiators For Use In The Preparation of Dispersant Polyalkenes
Broadly, any free-radical initiator capable of operating under the conditions of the reactions as outlined in the present specification is contemplated for use herein. Representative initiators are disclosed in U.S. Patent No. 4,146,489, column 4, lines 45-53, which is incorporated here by reference. Specific "peroxy" initiators contemplated herein include alkyl, diatkyl, and aryl peroxides, for example: di-t-butyl peroxide (abbreviated herein as "DTBP"), dicumyl peroxide, t-butyl cumyf peroxide, benzoyl peroxide, 216-dimethyl-2,5-di(t-buty3peroxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3. Also contemplated are peroxyester and peroxyketal initiators, for example: t-butyiperoxy benzoate, t-amylperoxy benzoate, t-butylperoxy acetate, t-butyiperoxy benzoate, di-t-butyl diperoxyphthaiate, and t-butylperoxy isobutyrate. Also contemplated are hydroperoxides, for example: cumene hydroperoxide, t-butyl hydroperoxide, and hydrogen peroxide. Also contemplated are azo initiators, for example: 2-f-butylazo-2-cyanopropane, 2-t-butylazc-l-cyanocyclohexane, 2,2-azobls(2,4-dimethylpentane nitrite), 2,2*-azobis(2-methylpropane nitrite), 1,1-azobis(cyclohexanecart)onitrile), and azoisobutyronftrile (AIBN). Other similar materials are also contemplated such as, but not limited to, diacyi peroxides, ketone peroxides and peroxydicarbonates. It is also contemplated that combinations of more than one initiator, including combinations of different types of initiators, may be employed.
Each such initiator commonly has a characteristic minimum reaction initiation temperature, above which it will readily initiate a reaction and below which the reaction
will proceed more slowly or not at ail. Consequently, the minfrnum reaction temperature is commonly dictated by the selected initiator.
D. Methods for Preparation of Dispersant Polyalkene
The grafting reaction may be carried out using one of several reaction
methods, namely, (1) radical reaction Initiator to promote radical grafting, (2)
chlorination procedure or (3) carrying out the "ene" reaction. The grafting reaction
may be carried out in solution and a more detailed discussion of this method may be
found in U.S. Patent Application No. 10/444,548 incorporated above by reference.
When carrying out the radical initiated reaction, both the initiator and the
monomer mixture may be used neat. Alternatively, they may be introduced info the polyalkene as a biend with appropriate solvents at a solids concentration ranging from about 15% to about 75%, for example, about 40%. The neat polyalkene fluid is introduced into a suitable well-stirred, heated reactor which can be purged or blanketed with an inerting gas, e.g., nitrogen, carbon dioxide, helium, or argon or otherwise isolated from the ambient air.
The polyalkene is heated to the desired reaction temperature, chosen, in part, so that essentially all of the initiator is consumed during the time allotted for the reaction. For example, if DTBP (di-t-butyl peroxide) is used as the initiator, the reaction temperature should be greater than about 160°C. Since the various acceptable initiators have different optimum reaction temperatures, the choice of a particular initiator may require adjustment of the reaction temperature or, alternatively, adjustment of the reaction time, in order to insure that the reaction conditions are compatible with the choice of initiator.
Consumption of initiator and reaction time are not the only determinants of the reaction temperature chosen, the temperature condition is also used to facilitate mixing and distribution of the reactant as well as maintaining fluidity of the polyalkene. Frequently, temperatures above 160°C will be employed.
1. Molar Proportion Of Monomer
The contemplated proportions of the graftabte monomer to the polyalkene and reaction conditions are selected so that an effective percentage (ideally, most or all of the reactant charge) of the graftabfe monomer will graft onto the polyalkene, rather than
forming dimeric, ofigorneric, or homopolymeric graft moieties or entire!/ independent homopolymers. The alternatively contemplated minimum mole ratios of the graftable monomer to the starting polyalkene are as follows:
at least about 0.1 mote,
alternatively at least about 0.2 moles,
af tematively at least about 0.5 moles,
alternatively at least about 0.8 moles,
alternatively at least about 1 mole,
alternatively at feast about 2 moles,
alternatively at least about 3 moles,
alternatively at least about 4 moles,
alternatively at least about 5 motes,
alternatively at least about 6 moles,
alternatively at least about 7 moles,
alternatively at least about 8 moles of the graftable monomer per mote of the starting polyalkene.
A contemplated maximum molar proportion of the graftable monomer to the
starting polyalkene may be desirable in several situations. For example, it may be preferable to select a contemplated maximum molar proportion of the graftable monomer to the starting polyalkene in order to facilitate manufacturing control of product quality.
The graftable monomer may be introduced into the reactor all at once, in several discrete charges, or at a steady rate over an extended period. The desired minimum rate of addition of the graftable monomer mixture to the reaction mixture is selected from:
at least about 0.1%,
alternatively at least about 0.5%,
alternatively at least about 1.0%,
alternatively at least about 2.0%,
alternatively at least about 5.0%,
alternatively at least about 10%,
alternatively at least about 20%,
alternatively at least about 50%,
alternatively at least about 100% of the necessary charge of graftable monomer mixture per minute. When added over time, the monomer can be added at an essentially constant rate, or at a rate which varies with time. Any of the above values can represent an average rate of addition or the minimum value of a rate which varies with tima
The desired maximum rate of addition is selected from:
at most about 0.5%,
alternatively at most about 1.0%,
alternatively at most about 2.0%,
alternatively at most about 5.0%,
alternatively at most about 20%,
alternatively at most about 100% of the necessary charge of graftable monomer mixture per minute. Any of the above values can represent an average rate of addition or the maximum value of a rate which varies with time.
The graftable monomer may be added as a neat liquid, in solid or molten form, or cut back with a solvent While it may be Introduced neat, it may be cut back with a solvent to avoid high localized concentrations of the monomer as it enters the reactor. In one embodiment, the monomer is diluted with a solvent The monomer can be diluted by at least about 1 times (50% concentration), alternatively at least about 5 times alternatively at least about 20 times, its weight or volume with a suitable solvent or dispersing medium,
2. Molar Proportion of Initiator
The contemplated proportions of the initiator to the graftable monomer and the reaction conditions are selected so that at least many, and ideally, all of the monomer will graft directly onto the polyotefin, rather than forming dtmertc, oligomeric, or homopolymeric graft moieties or entirely independent homopolymers. The contemplated minimum molar proportions of the initiator to the graftable monomer mixture are from about 0.05:1 to about 2:1. No specific maximum proportion of the initiator is contemplated, though too much of the initiator may degrade the polyalkene.
While the initiator may be added neat, in a preferred embodiment, it is introduced
"cut-back" with solvent in order to avoid focalized regions of elevated concentration.
The initiator can be added before, with or after the graftable monomer. For example, the Initiator may be added so that at any given time, the amount of unreacted initiator present is much iess than the entire charge, and preferably a small fraction of the entire charge. In one embodiment, the initiator may be added after substantially all the graftable monomer has been added, so there is an excess of both the graftable monomer and the polyolefin during essentially the entire reaction. In another embodiment, the initiator may be added along with the graftabie monomer, either at essentially the same rate (measured as a percentage of tne entire charge added per minute) or at a somewhat faster or slower rate, so there is an excess of polyolefin to unreacted initiator and unreacted monomer. For this embodiment, the ratio of unreacted initiator to unreacted monomer remains substantially constant during most of the reaction.
The initiator may be introduced into the reactor in several (or, alternatively, many) discrete charges, or at a steady rate over an extended period. The desired minimum rate of addition of the initiator to the reaction mixture ranges from at least about 0.1% of the necessary charge of initiator per minute to alternatively at least about 100% of the necessary charge of initiator per minute. The initiator can be added at an essentially constant rate, or at a rate which varies with time. The above rates can represent an average rate of addition or the minimum value of a rate which varies with time.
The desired maximum rate of addition of the initiator to the reaction mixture may vary from a maximum of at most about 0.1% of the necessary charge of initiator per minute to at about 100% of the necessary charge of initiator per minute. The above rates can represent an average rate of addition or the maximum value of a rate which varies with time.
While the initiator can be added neat, it is preferably cut back with a solvent to avoid high localized concentrations of the initiator as it enters the reactor. In a preferred embodiment, it is substantially diluted with a process fluid. The initiator can be diluted by at least about 5 times, alternatively at least about 10 times, alternatively at least about 20 times, alternatively at least about 50 times its weight or volume with a suitable solvent or dispersing medium.
3. Procedure for Grafting Reaction
After the reactants have been combined, the reaction mixture is preferably mixed with heating for an additional 2 to 120 minutes to complete the reaction. The time required for completion of the reaction can be determined experimentally, for example, by determining when the concentration of nitrogen or of monomer mixture in solution reaches a vafue at or approaching a minimum pre-established value.
After the reaction has gone essentially to completion, the heat can be removed and the reaction product can be allowed to cool in the reactor with mixing. Alternatively, more aggressive cooling can be employed, using a heat exchanger or other apparatus. Alternatively, the reaction product may be removed while still at or near reaction temperature.
111. Composition and Materials For preparation Of Lubricating Oil Compositions
Composition of Lubricating Oil Compositions
The lubricating oil compositions of the present invention preferably comprise the following ingredients in the stated proportions;
• a. from about 70% to about 99% by weight, alternatively from about 80% to about 99% by weight, alternatively from about 88% to about 99% by weight, of one or more base oils;
b. from about 0.0% solids to about 10% solids by weight alternatively from
about 0.05% solids to about 5% solids by weight alternatively from about
0.15% solids to about 2% solids by weight alternatively from about 0.15%
solids to about 1.5% solids by weight alternatively from 0.25% solids to
. about 1.5% solids by weight alternatively from 0.5% solids by weight to 1.5% solids by weight of one or more grafted polyolefins dispersant viscosity index improvers;
c. from 0.1% to about 20% by weight alternatively from about 0.2% to about
15% by weight alternatively from about 0.5% to about 10% by weight, or
altematfvefy from about 0.5% to about 8%. of one or more dispersants
which are grafted polyalkenes made according to the present invention;
d. from 0.0% solids to 10% solids by weight, alternatively from about 0.0%
solids to about 5% solids by weight, alternatively from about 0.05% solids
to about 2% solids by weight alternatively from about 0.1% solids to
about 1% solids by weight, of one or more norn-grafted polyofefins used as
viscosity index improvers;
e. from 0.0% to about 10% by weight, alternatively from about 0.2% to about
8% by weight, or alternatively from about 0.5% to about 6%, of one or
more dispersants which are not made according to the present invention;
f. from about 0.2% to 6% by weight, alternatively from about 0.3% to 4% by
weight, alternatively from about 0.3% to about 3% by weight, alternatively
from about 0.3% to about 2% by weight, of one or more detergents;
g. from about 0.01% to 5% by weight, alternatively from about 0.04% to
about 4% by weight, alternatively from about 0.06% to about 3% by
weight, of one or more anti-wear agents;
h. from about 0.01 % to 5% by weight, alternatively from about 0.01 % to 3% by weight alternatively from about 0.05% to about 2% by weight alternatively from about 0.1% to about 2% by weight of one or more antioxidants; and i. from about 0.0% to 4% by weight alternatively from about 0.0% to 3% by weight, alternatively from about 0.005% to about 2% by weight, alternatively from about 0.005% to about 1.5% by weight, of minor ingredients such as, but not limited to, friction modifiers, pour point depressants, and anti-foam agents. The percentages of d through i may be calculated based on the form in which they are commercially available. The function and properties of each ingredient identified above and several "examples of ingredients are summarized in the following sections of this specification.
A. Base Oils
Any of the petroleum or synthetic base oils previously identified as process solvents for the graftable polyalkenes of the present invention can be used as the base oil. Indeed, any conventional lubricating oil, or combinations thereof, may also be used.
B. Grafted Polyolefin Dispersant Viscosity Index Improves
The grafted polyolefins are discussed in more detail in section D below.
C. Dispersant Polygenes
The dispersant polyalkene according to the present invention contains:
at least about 0.2 moles,
alternatively at feast about 0.5 moles,
alternatively at least about 0.8 moles,
alternatively at least about 1 mole,
alternatively at least about 2 motes,
alternatively at least about 3 moles,
alternatively at least about 4 moles,
alternatively at least about 5 moles,
alternatively at least about 6 moles,
alternatively at least about 7 moles,
alternatively at least about 8 moles, of grafted monomer mixture per mole of the original polyalkene.
D. Grafted and Non-Grafted Polyolefins used as Viscosity Modifiers
The conventional viscosity index improving polyolefins can be used in the
. formulations according to the present invention. These are conventionally long-chain polyolerlns. Several examples of polyolefins contemplated for use herein include polyisobutenes, polymethacrytates. polyalkytstyrenes, partially hydrogenated copolymers of butadiene and styrene, amorphous polyolefins of ethylene and propylene, ethylene-propylene diene polymers, poryisoprene, and styrene-isoprene. Dispersant viscosity modifiers, as taught in U.S. Patent Application No. 10/444,548 as well as U.S. Patent No. 5.523,008 and patents cited therein, can also be used according to the present invention.
E. Conventional Dispersants
Other dispersants also help suspend insoluble engine oil oxidation products, thus preventing sludge flocculatfort and precipitation or deposition of particulates on metal parts. Suitable dispersants include high molecular weight alky! succinimides and the reaction products of oil-soluble polyisobutylene succinic anhydride with ethylene amines such as tetraethylene pentamine and borated salts thereof.
Such conventional dispersants are also contemplated for use herein, although frequently they can be used at reduced concentrations when the grafted poryolefins according to the present Invention are used. Several examples of dispersants include those listed in U.S. Patent No. 4,092,255, column 1, lines 38-41: succinimides or succinic esters, alkylated with a polyolefin of isobutene or propylene, on the carbon in the alpha position of the succinimide carbonyi. These additives are useful for maintaining the cleanliness of an engine or other machinery.
F. Detergents
Detergents to maintain engine cleanliness can be used in the present lubricating oil compositions. These materials include the metal salts of sulfonic acids, alky! phenols, sulfurized alkyl phenols, alkyi salicylates, naphthenates, and other soluble mono- and dicarboxylic acids. Basic (vis, overbased) metal salts, such as basic alkaline earth metal sulfonates (especially calcium and magnesium salts) are frequently used as detergents. Such detergents are particularly useful for keeping the insoluble particulate materials in an engine or other machinery in suspension. Other examples of detergents contemplated for use herein include those recited in U. S. Patent No. 4,092,255, column 1, lines 35-36: sulfonates, phenates, or organic phosphates of polyvalent metals.
G. - Anti-Wear Agents
Anti-wear agents, as their name implies, reduce wear of metal parte. Zinc diaikytdithiophosphates and zinc diaryldithiophosphates and organo molybdenum compounds such as molybdenum dialkyldithiocarbamates are representative of conventional anti-wear agents.
H. Anti-Oxidants
Oxidation inhibitors, or anti-oxidants, reduce the tendency of lubricating oils to deteriorate in service. This deterioration can be evidenced by increased oil viscosity and by the products of oxidation such as sludge and varnish-like deposits on the metal surfaces. Such oxidation inhibitors include alkaline earth metal salts of aflcyiphenolthioesters having preferably C5 to C12 alkyt side chains, e.g., calcium nanylphenol sulfide, dfoctylphenylamine, phenyl-alpha-naphthylamine, phospnosuffurteed or suffurized hydrocarbons, and organo molybdenum compounds such as molybdenum dialkyldithiocarbamates.
I. Pour Point Depressants and other Minor Ingredients
Pour point depressants, otherwise known as lube oil flow improvers, lower the temperature at which the fluid will flow or can be poured. Such additives are well known. Typical of those additives which optimize the low temperature fluidity of a lubricant are C8-C18-dialkylfumarate vinyl acetate copolymers, and polymethacrylates.
Many minor ingredients which do not prevent the use of the present compositions as lubricating oils are contemplated herein. A non-exhaustive list of other such additives includes rust inhibitors, as well as extreme pressure additives, friction modifiers, antifoam additives, and dyes,
WORKING EXAMPLES
Example 1
Laboratory Preparation of Bi-Functional Monomer for Grafting
In this example, an ethylenically-unsaturated monomer containing both nitrogen and'oxygen, having two sites of unsaturation, is prepared. A 500 ml reactor equipped with an electric heating mantle, stirrer, thermometer and water-cooled reflux condenser is charged with about 14 ml of N,N-dimethyl formamide and about 7.0 g of malefc anhydride. The reactor temperature is raised to about 150'C and allowed to reflux at temperature. While at that temperature, about 5g of Methylene tetramine are quickly introduced into the solution. The reaction proceeds for about 3 hours and leads to the formation of a mixture of reaction products comprising amic acids and di-maieimide. e.g., the formation of a bi-functional monomer mixture. This reaction
mixture, without subsequent purification or separation of components, is suitable for grafting onto a polyalkene.
Example 2
Laboratory Preparation of Graft Low Molecular Weight Polyalkene
A resin kettle equipped with an electric heating mantle, stirrer, thermometer and gas inlet is charged with about 100g of a neat potyalkene. The gas inlet permits the gas to be fed either below or above the surface of the solution. The polyalkene Is heated to 170°C. During heating the polyafkene is purged with an inerting gas (CO2) fed below the surface of the solution. When the polyalkene reaches the appropriate temperature of 170°C, the puige gas is redirected to flow over the surface of the polyalkene. With the polyalkene at temperature, two solutions, one containing the monomer mixture from Example 1 and the other containing di-t-butyl peroxide Initiator are introduced. The monomer mixture is prepared by dissolving about 25g of the monomer from Example 1 in 25 mi of THF. The initiator solution is prepared by dissolving about 10 g of di-t-butyl peroxide in 60 ml of heptane. Five aliquots of the monomer solution are introduced into the resin kettle over a sixty minutes period. The full charge of initiator solution is metered into the resin kettle over the same sixty minutes period. After all of the reactants are added, the mixture is allowed to react for five (5) hours.
Example 3
Laboratory Preparation of Graft Low Molecular Weight Polyalkene
A resin kettle equipped with an electric heating mantle, stirrer, thermometer and gas inlet was charged with about 11.8 g of a neat polyalkene (indopol H-100) and about 29.8 g of o-dichtorobenzene (about 28% by wt). The gas inlet permits the gas to be fed either below and/or above the surface of the solution. The mixture of the polyalkene and o-dichiorobenzene was heated to 170°C. During heating the polyalkene solution was purged with an inerting gas (CO2) fed below the surface of the solution. When the polyafkene solution reached the appropriate temperature of about 170*0, the purge gas was redirected to flow over the surface of the polyalkene solution,
While maintaining the solution at the reaction temperature of 170°C about 3.43g of a mono-functional monomer mixture, based upon the reaction between 4~ aminophenylenediamine and malelc anhydride, was introduced all at once into the polyalkene solution. A solution containing a total of about 4.2 g of dk-butyl peroxide initiator in heptane was then delivered over 3 hours. The reactants were refluxed for an additional 45 minutes after all of the t-butyt peroxide solution was introduced. When the reaction was complete, the o-dichlorobenzene was distilled from the reaction mixture at atmospheric pressure. The resultant grafted tow molecular weight polyalkene was washed with acetone and was, then, dried under vacuum at 60°C. An IR spectrum of the graft product exhibited peaks at 1600 cm-1, 1720 cm1 and 1780 cm'1.
Example 4
Laboratory Preparation of Graft Low Molecular Weight Polyalkene
A resin kettle equipped with an electric heating mantle, stirrer, thermometer and gas inlet is charged with about 100g of a neat polyalkene. The gas inlet permits the gas to be fed either below or above the surface of the solution. The polyalkene is heated to 170°C. During heating, the polyalkene is purged with an fnerting gas (CO2) fed below the surface of the solution. When the poryalkene reaches the appropriate temperature of 170°C, the purge gas is redirected to flow over the surface of the polyalkene. With the polyalkene at temperature, two solutions, one containing a mono-functional monomer mixture based upon the reaction between 4-. aminophenylenediamine and malelc anhydride and the other containing di-t-butyl peroxide initiator are introduced. The monomer mixture is prepared by dissolving about 22g of the monomer in 26 ml of THF. The initiator solution is prepared by dissolving about 10 g of di-t-butyl peroxide in 60 ml of heptane. Five aliquots of the monomer solution are Introduced Into the resin kettle over a sixty minutes period. The full charge of initiator solution is metered into the resin kettle over the same sixty minutes period. After all of the reactants are added, the mixture is allowed to react for five (5) hours.






We Claim:
1. A method of making a graft polyalkene dispersant which is a graft reaction
product of an ethylenically unsaturated, oxygen- and nitrogen-containing, aliphatic or
aromatic reaction product grafted on a polyalkene backbone,
the method comprising the steps of (1) reacting an amine and an acylating agent having at least one point of ethylenic unsaturation to form a reaction product, wherein the amine is selected from the group consisting of primary amines and secondary amines, and (2) grafting at least a portion of the reaction product onto a polyalkene backbone having a number average molecular weight of from about 300 to about 10,000 to form a grafted polyalkene, wherein the molar proportion of the grafted portion of the reaction product to the polyalkene backbone is at least about 0.5:1.
2. The method of claim 1, wherein the polyalkene backbone is selected from the
group consisting of olefin homopolymers, copolymers and terpolymers.
3. The method of claim 1, wherein the polyalkene backbone is selected from the
group consisting of polyethylene, polypropylene, ethylene-propylene copolymers, and
ethylene/ propylene/diene copolymers.
4. The method of claim 1, wherein the polyalkene backbone is selected from the
group consisting of polyisobutene, polymethacrylates, polyalkylstyrenes, partially
hydrogenated polyolefins of butadiene and styrene.
5. The method of claim 1, wherein the amine has more than one primary or secondary amine.

Documents:

2294-del-2004-Abstract-(20-04-2012).pdf

2294-DEL-2004-Abstract-(23-04-2012).pdf

2294-del-2004-abstract.pdf

2294-DEL-2004-Claims-(22-02-2012).pdf

2294-DEL-2004-Claims-(23-04-2012).pdf

2294-del-2004-Claims-Final-(20-04-2012).pdf

2294-del-2004-claims.pdf

2294-del-2004-Correspondence Others-(20-04-2012).pdf

2294-DEL-2004-Correspondence Others-(22-02-2012).pdf

2294-DEL-2004-Correspondence Others-(23-04-2012).pdf

2294-DEL-2004-Correspondence Others-(31-01-2012).pdf

2294-del-2004-correspondence-others.pdf

2294-DEL-2004-Description (Complete)-(23-04-2012).pdf

2294-del-2004-description (complete).pdf

2294-del-2004-Description Complete-Final-(20-04-2012).pdf

2294-del-2004-form-1.pdf

2294-del-2004-Form-13-(17-03-2009).pdf

2294-del-2004-form-13.pdf

2294-del-2004-form-18.pdf

2294-del-2004-Form-2-(20-04-2012).pdf

2294-DEL-2004-Form-2-(23-04-2012).pdf

2294-del-2004-form-2.pdf

2294-DEL-2004-Form-3-(31-01-2012).pdf

2294-del-2004-form-3.pdf

2294-del-2004-form-5.pdf

2294-del-2004-gpa.pdf

2294-DEL-2004-Petition-137-(31-01-2012)-1.pdf

2294-DEL-2004-Petition-137-(31-01-2012).pdf


Patent Number 252278
Indian Patent Application Number 2294/DEL/2004
PG Journal Number 19/2012
Publication Date 11-May-2012
Grant Date 04-May-2012
Date of Filing 19-Nov-2004
Name of Patentee CASTROL LIMITED
Applicant Address WAKEFIELD HOUSE, PIPERS WAY, SWINDON, WILTSHIRE SN3 1RE, GREAT BRITAIN
Inventors:
# Inventor's Name Inventor's Address
1 GOLDBLATT, IRWIN, L 8 CELLAR ROAD, EDISON, NEW JERSEY 08817, U.S.A
PCT International Classification Number A61K
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/523,959 2003-11-21 U.S.A.