Patent GB-638355-A (GB)
Title: Improved hydrocarbon lubricating or damping oil compositions
IPC: C08F16/12
Filed: 1946-09-30
Abstract: Lubricating oil or hydraulic mechanism damping oil compositions comprise a major proportion of a hydrocarbon oil and a minor proportion, e.g. 0.01-10 per cent, of a copolymer of a vinyl alkyl ether and an olefin, prepared in the presence of a Friedel-Crafts halide catalyst at a temperature below - 50 DEG  C. and having a molecular weight of at least 5000 (see Group IV (a)). The olefin may contain 2-6 carbon atoms and may be propylene, isobutylene, tetramethyl ethylene or trimethyl ethylene.  The copolymer may contain 1-95 per cent, and preferably 5-80 per cent of vinyl ether and 95-5 per cent of olefin.  The vinyl ether may contain 3-30, and preferably 4-20 carbon atoms, e.g. vinyl isobutyl ether, vinyl lauryl ether, vinyl cetyl ether, vinyl octadecyl ether, or vinyl ethers of mixed alcohols such as those derived from coconut oil.  The composition may contain a minor proportion of a fatty oil, e.g. 1-10 per cent by weight based on the mineral oil present.  A modification of the composition comprises a major proportion of a mineral lubricating oil, a grease-producing amount of a grease-forming soap and a copolymer of a vinyl alkyl ether and an olefin having 2-5 carbon atoms, said copolymer comprising 5-95 per cent of combined vinyl ether constituent, having a molecular weight of at least 5000, and being prepared in the presence of a Friedel-Crafts halide catalyst at a temperature below - 50 C.  The copolymers are said to function both as pour depressors and as viscosity index improvers, their efficiency in the latter respect increasing with their molecular weight.  They are said to be soluble even in highly paraffinic hydrocarbon oils even when the molecular weight of the copolymer is 60,000 or higher.  The hydrocarbon oil constituent may be naphthenic or paraffinic and may have a viscosity of 30-150 S.U.S. at 210 DEG  F.  Alternatively it may be a gas oil, mineral seal oil or even kerosine.  Specification 441,064, [Group IV], is referred to.ALSO:Lubricating oil or hydraulic mechanism damping oil compositions comprise a major proportion of a hydrocarbon oil and a minor proportion, e.g. 0.01-10 per cent, of a copolymer of a vinyl alkyl ether and an olefin prepared in the presence of a Friedel-Crafts halide catalyst at a temperature below -50 DEG  C. and having a molecular weight of at least 5000.  The olefin may be propylene, isobutylene, tetramethyl ethylene or trimethyl ethylene. The vinyl ether may be vinyl isobutyl ether, vinyl lauryl ether, vinyl cetyl ether, vinyl octadecyl ether or vinyl ethers of mixed alcohols derived from coconut oil.  The composition may contain a minor proportion (e.g. 1-10 per cent by weight of the hydrocarbon oil) of a fatty oil.  In a modification, the composition comprises a major proportion of a mineral lubricating oil, a grease-producing amount of a grease-forming soap and the copolymer of a vinyl alkyl ether and an olefin having 2-5 carbon atoms.  The copolymers are said to function both as pour depressors and as viscosity index improvers. The hydrocarbon oil may be naphthenic or paraffinic or a gas oil, mineral seal oil or kerosine.  In preparing the copolymer it is preferred to use an inert solvent such as a refined petroleum naphtha, pentane, or a lighter hydrocarbon such as propane or ethane. The lower alkyl halides such as methyl or ethyl chloride, ethylidene difluoride, methylene chloride and carbon bisulphide may also be used.  An alternative solvent is ethylene.  The preferred catalyst is aluminium chloride, but boron fluoride, AlBr2Cl, Al2Br5Cl, AlCl3.(ClCH2CH2)2O, BF3.(ClCH2CH2)2O, BF3. C6H5OCH3, BF3.ethyl ether complex, TiCl4. (ClCH2CH2)2O or 2TiCl4.(ClCH2CH2)2O may be used. After the completion of copolymerization, residual catalysts may be neutralized or hydrolysed by the addition of an alcohol such as ethyl alcohol or isopropyl alcohol or dilute aqueous caustic soda. The copolymers may be recovered from the solvent by precipitation or by distilling off the solvent, or a small amount of non-volatile mineral oil may be added to the reaction mixture and the copolymer recovered as a solution in the oil.  Specification 441,064 is referred to.