Patent GB-922274-A (GB)
Title: Lubricant composition and a copolymer additive therefor
IPC: C10M145/14
Filed: 1960-07-26
Abstract: Lubricating oil compositions comprise copolymers of (A) a vinyl alkyl ether having 2 to 8 carbon atoms in the alkyl group and (B) one or more alkyl acrylates or methacrylates having 4 to 12 carbon atoms in the alkyl groups, the total of the number of carbon atoms in the alkyl group of (A) and the average number of carbon atoms in the alkyl group of (B) being 8 to 12, the molar ratio of (A) to (B) being approximately 1:1 and the molecular weight of the copolymers being at least 50,000.  The vinyl ether may be vinyl ethyl, isobutyl, n-butyl, or 2-ethylhexyl ether, and the alkyl esters may be the butyl, hexyl, octyl, 2-ethylhexyl, decyl and "oxo" decyl esters.  A list of terpolymers is given. Specified lubricating oils are paraffin base and naphthenic base oils, alkylated hydrocarbon waxes, hydrogenated hydrocarbon polymers, polymers of alkylene oxides, such as propylene and ethylene oxides, and derivatives thereof, e.g. the acetate of the 2-ethylhexanol initiated polymer of propylene oxide, long chain esters, e.g. di(2-ethylhexyl)sebacate, tricresyl phosphate and silicate esters such as hexa(2-ethylbutoxy)di-siloxane. The compositions may also comprise alkaline earth metal higher alkyl phenates and sulphonates, reaction products of pinene and phosphorus pentasulphide, zinc butyl hexyl dithiophosphate, zinc tetradecyl phenyl dithiophosphate, diparaffin polysulphides and silicones.ALSO:Copolymers are made from (A) a vinyl alkyl ether having 2 to 8 carbon atoms in the alkyl group and (B) one or more alkyl acrylates or methacrylates having 4 to 12 carbon atoms in the alkyl groups, the total of the number of carbon atoms in the alkyl group of (A) and the average number of carbon atoms in the alkyl group of (B) being 8 to 12, the molar ratio of (A) to (B) being approximately 1:1 and the molecular weight of the copolymer being at least 50,000.  The vinyl ether may be vinyl ethyl, isobutyl, n-butyl or 2-ethylhexyl ether and the alkyl esters may be the butyl, hexyl, octyl, 2-ethylhexyl, decyl, or oxo decyl esters. The copolymers may be prepared by conventional bulk, solution or emulsion methods using an initiator such as a peroxy compound, e.g. benzoyl, acetyl, di-t-butyl dibenzoyl and di-t-amyl peroxides or t-butyl hydroperoxide or potassium persulphate, or an azo compound, e.g. azodiisobutyronitrile or azodicyclohexanecarbonitrile.  The solvent for solution polymerization may be benzene, toluene, xylene or petroleum naphtha.  The catalyst or solvent may be added incrementally during the polymerization.  The polymerization may be carried out in emulsion using sodium lauryl sulphate as dispersing agent. Comparative examples are given including terpolymers of vinyl isobutyl ether, n-butyl acrylate and u-octyl acrylate; vinyl isobutylether, n-butyl methacrylate and n-octyl methacrylate; vinyl isobutyl ether, 2-ethyl hexyl methacrylate and n-octadecyl methacrylate; vinyl isobutyl ether, "oxo" decyl methacrylate and n-octadecyl methacrylate; vinyl isobutyl ether, n-butyl acrylate and 2-ethyl hexyl acrylate; vinyl n-butyl ether, n-octyl acrylate and n-butyl acrylate; and vinyl n-butyl ether, n-decyl acrylate and n-octyl acrylate.  The polymers may be mixed with lubricating oils such as paraffin base or naphthenic base oil, alkylated hydrocarbon waxes, hydrogenated hydrocarbon polymers and mixed aromaticaliphatic oils or oxygen-containing oils such as polyalkylene oxides and their derivatives, long chain esters, e.g. di-(2-ethylhexyl) sebacate, tricresyl phosphate, and silicate esters.  Other additives may also be added to the oil-polymer compositions such as anti-oxidants, corrosion inhibitors, blooming agents, detergents and anti-wear agents, e.g. alkaline earth metal, higher alkylphenate and sulphonate detergents or organic thiophosphate corrosion and oxidation inhibitors, e.g. zinc di(alkyl phenyl) dithiophosphate, paraffin polysulphides or silicone foam inhibitors.