Patent GB-781725-A (GB)
Title: Lubricant composition and additives therefor
IPC: C10M151/02
Filed: 1954-05-12
Abstract: Lubricating compositions comprise a major proportion of a lubricating oil and a minor proportion of an oil-soluble copolymer derived from (A) a compound containing an ethylenic linkage and a group of from 4 to 30 aliphatic carbon atoms; (B) a lower aliphatic alpha, beta-unsaturated monocarboxylic acid having from 3 to 8 carbon atoms; and (C) a compound having the structural formula <FORM:0781725/III/1> where R1 is hydrogen or a methyl group and R2 is a nitrogen-containing radical having the structure -OH.NR3R3R4 or -NR3R4, i which R3 is a hydrogen atom or an organic radical and R4 is an organic radical substituted by one or more amino, hydroxy, mercapto or nitro groups, the copolymer having a molecular weight of at least 2000 and approximately 1 to 20 monomer units of (A) for each monomer unit of (B) and (C), there being present at least one monomer unit of each of (B) and (C) in the copolymer. Copolymers derived from the following monomers are described: (a) dodecyl methacrylate, methacrylic acid and N-(2-hydroxyethyl) methacrylamide; (b) dodecyl methacrylate, methacrylic acid and the dihydroxyethyl ethylenediamine salt of methacrylic acid; (c) dodecyl methacrylate, methacrylic acid and N-(2-hydroxyethyl)-N-(3-aza-5-hydroxypentyl) methacrylamide; (d) 2-ethylhexyl allyl ether, acrylic acid and N-(2-hydroxyethyl) acrylamide; (e) di-(2-ethylhexyl) maleate, acrylic acid and N-(4-mercaptobutyl) methacrylamide; (f) di-isobutylene, methacrylic acid and N-(2-hydroxyethyl)-N-(3-aza-5-hydroxypentyl) methacrylamide; and (g) allyl stearate acrylic acid and the dihydroxyethyl ethylenediamine salt of acrylic acid.  The copolymers are added to mineral or synthetic lubricating oils in order to improve their detergent and anti-wear properties. Synthetic lubricating oils specified are alkylated waxes, hydrogenated polymers of hydrocarbons, condensation products of chlorinated alkyl hydrocarbons with aryl compounds, polymers of ethylene and/or propylene oxide and their esterification and etherification products, e.g. the acetate of 2-ethyl hexanol-initiated polypropylene oxide, di-(2-ethylhexyl) sebacate, tricresyl phosphate and silicate esters.ALSO:Oil-soluble copolymers are derived from (A) a compound containing an ethylenic linkage and a group of from 4 to 30 aliphatic carbon atoms; (B) a lower aliphatic alpha, beta-unsaturated monocarboxylic acid having from 3 to 8 carbon atoms; and (C) a compound having the structural formula <FORM:0781725/IV (a)/1> where R1 is hydrogen or a methyl group and R2 is a nitrogen-containing radical having the structure -OH.NR3R3R3R4 or -NR3R4, in which R3 is a hydrogen atom or an organic radical and R4 is an organic radical substituted by one or more amino, hydroxy, mercapto or nitro polar groups, the copolymer having a molecular weight of at least 2000 and approximately 1 to 20 monomer units of (A) for each monomer unit of (B) and (C), there being present at least one monomer unit of each of (B) and (C) in the copolymer.  Monomers (A) listed include aromatic and aliphatic olefines, unsaturated ethers and esters of unsaturated alcohols and acids; monomers (B) specified are acrylic, methacrylic, crotonic, tiglic, angelic, alpha-ethylacrylic, alpha-methylcrotonic, alphaethylcrotonic, beta-ethylcrotonic, alpha-butylcrotonic, hydrosorbic and alpha-ethylhydrosorbic acids; monomers (C) listed are the amine and amide salts of acrylic, methacrylic and crotonic acids. The copolymers may be prepared by copolymerizing the monomers in bulk, emulsion or solution in solvents such as benzene, toluene, xylene or naphtha in the presence of catalysts such as benzoyl, dibenzoyl acetyl, ditert.-butyl and di-tert-amyl peroxides, tert.-butyl hydroperoxide, azodiisobutyronitrile and azodicyclohexane - carbonitrile.  During polymerization additional portions of catalyst and solvent may be added as the reaction proceeds. Alternatively the copolymers may be prepared by appropriate treatment of a preformed polymer.  In examples: (1) dodecyl methacrylate is partially hydrolysed and then amidated with ethanolamine; (2) the dihydroxyethyl ethylenediamine salt of partially hydrolysed dodecyl methacrylate is prepared; (3) acrylic acid, 2-ethylhexyl allyl ether and N-(2-hydroxyethyl) acrylamide are copolymerized; and (4) acrylic acid, 2-ethylhexyl maleate and N-(4-mercaptobutyl) methacrylamide and methacrylic acid, di-isobutylene and N-(2-hydroxyethyl)-N-(3-aza-5-hydroxypentyl) methacrylamide are copolymerized.  The copolymers are used as additives to natural and synthetic lubricating oils.