Patent GB-759918-A (GB)
Title: Lubricant composition
IPC: C10M159/00
Filed: 1953-10-06
Abstract: An oil-soluble copolymer comprises monomer units of (A) an ethylenic compound which contains a group of from 4 to 30 aliphatic or cycloaliphatic carbon atoms; and (B) an aliphatic alpha, beta-unsaturated carboxylic acid, wherein at leaast a proportion of the carboxyl groups are ester linked to a polypolar alcohol in which at least half and not less than two of the carbon atoms are attached to hydroxy, nitro, mercapto and/or amino polar groups, the copolymer molecule containing from 1 to 20 monomer units for each (B), and not more than 10 units of an ester of the (B) component with a polypolar alcohol, the molecular weight of the copolymer being at least 2000. Compounds of type (A), of which numerous examples are provided, are aliphatic, cycloaliphatic and aromatic mono-olefines, diolefines, vinyl, allyl, propenyl, isopropenyl, methallyl, crotyl, decenyl and eicosenyl ethers, and esters of unsaturated acids and unsaturated alcohols.  Compounds of type (B) specified are acrylic, methacrylic, crotonic, tiglic, angelic, alpha-ethylacrylic, alpha-methylcrotonic, alpha-ethylcrotonic, beta-ethylcrotonic, alpha-butylcrotonic, hydrosorbic, maleic, fumaric, citraconic, mesaconic, itaconic and aconitic acids.  Polypolar alcohols specified with which the above acids are esterified are ethylene glycol, glycerine, ethanolamine, diethanolamine, triethanolamine, 1,2-propylene glycol, sorbitol, mannitol, glucose, erythritol, pentaerythritol, dipentaerythritol, tripentaerythritol, nitroethanol, mercaptoethanol, 3-mercaptopropanol, 3,5 - dihydroxycyclohexanol, hydroxyethylethylenediamine, N,N1 - dihydroxyethylethylenediamine and 2-aza-propanol.  The copolymers may be prepared by (1) copolymerizing the monomer components to produce the desired copolymer, for example by copolymerizing a mixture of dodecyl methacrylate, methacrylic acid and pentaerythritol monomethacrylate, or a mixture of 2-ethylhexyl allyl ether, acrylic acid and 2-hydroxyethyl methacrylate; (2) partially hydrolysing a homopolymer such as polydodecyl methacrylate and then esterifying the resulting carboxyl groups with a polypolar alcohol such as pentaerythritol or ethanolamine; (3) preparing an acid copolymer, for example of maleic anhydride and 2-ethylhexyl acrylate and then esterifying the carboxyl groups thereof with a polypolar alcohol such as pentaerythritol; and (4) preparing an acid copolymer, for example of maleic anhydride and allyl stearate, and first esterifying a proportion of the carboxyl groups with dodecyl alcohol and then esterifying a proportion of the remaining carboxyl groups with a polypolar alcohol such as ethanolamine or dihydroxyethylene diamine.  The copolymers, or their polymeric intermediates, may be prepared by bulk, emulsion or, preferably, solution methods, suitable solvents being benzene, toluene, xylene or petroleum naphtha.  Polymerization may be assisted by catalysts such as benzoyl peroxide, acetyl peroxide, tert. butyl hydroperoxide, ditert. butyl peroxide, dibenzoyl peroxide, ditert. amyl peroxide, 1,11-azodicyclohexane carbonitrile or alpha,alpha1-azodi-isobutyronitrile.  As the polymerization proceeds catalyst can be added in increments and additional portions of solvent can also be added from time to time.  The copolymers are used as additives to lubricating oils which may be natural hydrocarbon lubricants or synthetic lubricants such as alkylated wax, hydrogenated polymers of hydrocarbons, condensation products of chlorinated alkyl hydrocarbons with aryl compounds, polymers of propylene and/or ethylene oxides, oils obtained by the etherification and/or esterification of alkylene oxide polymers, e.g. the acetate of the 2-ethylhexanol initiated polymer of propylene oxide, tricresyl phosphate, di-(2-ethylhexyl) sebacate, and silicate esters.ALSO:Lubricating compositions comprise a major proportion of an oil of lubricating viscosity and a minor proportion sufficient to enhance the detergent characteristics of the oil of a copolymer of (A) an organic compound which contains an ethylenic linkage and, in addition, a group of from 4 to 30 aliphatic or cycloaliphatic carbon atoms, and (B) an aliphatic alpha, betaunsaturated carboxylic acid, wherein at least a proportion of the carboxyl groups of the (B) component are ester linked to a polypolar alcohol in which at least half and not less than two of the carbon atoms present therein are attached to hydroxy, nitro, mercapto, and/or amino polar groups, the copolymer molecule containing from 1 to 20 monomer units of the (A) component for each monomer unit of the (B) component, and not more than 10 units of a ester of the (B) component with a polypolar alcohol, the total number of monomer units in each copolymer being such that a molecular weight of at least 2000 is obtained.  Compounds of type (A), of which numerous examples are provided are aliphatic, cycloaliphatic and aromatic mono-olefines, diolefines, vinyl allyl, propenyl, isopropenyl, methallyl, crotyl, decenyl and eicosenyl ethers, and esters of unsaturated alcohols and unsaturated acids. Compounds of type (B) specified are acrylic, methacrylic, crotonic, tiglic, angelic, alpha-ethylacrylic, alpha-methylcrotonic, alpha-ethylcrotonic, beta-ethylcrotonic, alpha-butylcrotonic, hydrosorbic, maleic, fumaric atraconic, mesaconic, itaconic, and fumaric acids.  Polypolar alcohols specified with which the above acids are esterified are ethylene glycol, glycerine, ethanolamine, diethanolamine, triethanolamine, 1, 2 - propylene glycol, sorbitol, mannitol, glucose, erythritol, pentaerythritol, dipentaerythritol, tripentaerythritol, nitroethanol, mercaptoethanol, 3 - mercaptopropanol, 3, 5 - dihydroxycyclohexanol, hydroxyethylene diamine, N, N1 - dihydroxyethylethylene diamine, and 2 - aza - propanol.  The lubricating oils used may be natural hydrocarbon lubricants or synthetic lubricants such as alkylated waxes, hydrogenated polymers of hydrocarbons, condensation products of chlorinated alkyl hydrocarbons with aryl compounds, polymers of propylene and/or ethylene oxides, oils obtained by the etherification and/or esterification of alkylene oxide polymers, e.g. the acetate of the 2-ethylhexanol initiated polymer of propylene oxide, tricresyl phosphate, di(2 - ethylhexyl)sebacate, and silicate esters.