GB683465A - Lubricating oil additives - Google Patents

Abstract

Copolymers are prepared from (1) an ester of an a -methylene dicarboxylic acid, e.g. of the general formula <FORM:0683465/IV (a)/1> in which R and R1 are the same or different alkyl groups and n is an integer from 0 to 3, e.g. itaconic, a -methylene malonic, glutaric and adipic esters, and (2) a monomer containing an ethylenic double bond and oxygen in the form of carboxyl, carbonyl or ether groupings, e.g. an ester of the general formula <FORM:0683465/IV (a)/2> where R is hydrogen or alkyl, R1 is hydrogen or halogen, R11 is hydrogen, alkyl or halogen and R111 is an alkyl, alicyclic, aralkyl or alphyl radical, with unsaturation either in the acid group, e.g. methyl acrylate or methacrylate and crotonate and halogenated derivatives thereof, or in the alcohol group, e.g. vinyl acetate, propionate and butyrate, at least one of the monomers containing a C6 to C24 open-chain hydrocarbon radical. Ester groups may be derived from alcohols such as methyl, ethyl, butyl, octyl, decyl or lauryl, or mixtures of C10 to C18 alcohols derived from hydrogenated coconut oil, branched-chain primary alcohols, those synthesized from carbon-monoxide and hydrogen or by the "oxo" reaction from olefines, from cyclohexanol, methylcyclohexanol, hydrogenated alkyl phenols, phenylethanol, alkylated phenols or cresols, which in turn may contain other functional groups such as -NH2, -CN, -NO2, -OR, or -O-O(CH2)n-O-R, or from synthetic saturated or unsaturated acids derived from the oxidation of "oxo" aldehydes or the reaction of olefines, carbon-monoxide, and water. Instead of the diesters (1), half esters may be used and the resulting copolymer may then be reacted with an alcohol, a primary or secondary amine, ammonia or a metal compound. Bulk or emulsion polymerization methods may be used with a catalyst, e.g. benzoyl peroxide, t.-butyl or cumene hydroperoxide, aluminium chloride, boron trifluoride, ultra-violet light or activated clay with or without a diluent such as a mineral oil. Examples describe the preparation of copolymers of "Lorol" (Registered Trade Mark) B itaconate and vinyl acetate, methyl acrylate or methyl methacrylate; decyl itaconate and methyl acrylate or methacrylate; dimethyl itaconate and decyl or octyl decyl methacrylate, or octyl (oxo), decyl, lauryl or "Lorol" R acrylate; diethyl or dibutyl itaconate and octyl (oxo) acrylate. The copolymers of molecular weight 1000 to 50,000 may be blended with lubricating oils as viscosity index improvers and pour-point depressants. Specifications 666,990 and 13819/40 (as open to inspection under Sect. 91) are referred to.ALSO:N-Decyl itaconate is prepared by heating n-decanol and itaconic acid in naphtha with sulphosalicylic acid as a catalyst, and purified by washing with 5 per cent sodium bicarbonate solution, then with water, stripping off the naphtha with nitrogen and filtering through diatomaceous earth. Specifications 666,990, [Group IV (a)], and 13819/40 (as open to inspection under Sect. 91) are referred to.ALSO:Copolymers of esters of a-methylene dicarboxylic acids with monomers containing an ethylenic double bond and oxygen in the form of carboxyl, carbonyl or ether groups, at least one of the monomers containing a C6 to C24 open chain hydrocarbon radical (see Group IV (a)) are used as viscosity index improvers and pour point depressants for mineral oils derived from paraffinic, naphthenic, or asphaltic crudes and synthetic oils. The copolymer may comprise 0.01 to 10 per cent by weight of the total composition. Rust inhibitors, detergents, extreme pressure agents and dyes may also be added.