Patent GB-601258-A (GB)
Title: Improved polymerisation products, particularly for use as lubricating oil additives
IPC: F02B47/00
Filed: 1945-06-18
Abstract: Polymers of esters of thioacrylic acid and its homologues (see Group IV) are used as additives to lubricating oils.  Copolymers of two or more thioacrylic esters and copolymers of thioacrylates with acrylates and methacrylates may also be used.  The polymers range from viscous liquids or tacky solids to hard, resinous or rubbery solids.  They are suitable as additives to lubricating oils to increase viscosity, load carrying capacity and resistance to oxidation at elevated temperatures.  Preferably the amount added is from 0.1 to 10 per cent by weight of the oil.  Specified are paraffinic naphthenic or mixed base oils.  They may also be incorporated in paraffin wax, petrolatum, asphalt, diesel fuels, kerosene and gasoline, or be used for thickening vegetable or animal oils.ALSO:Polymers of esters of thioacrylic acid and its homologues are obtained by preparing and polymerizing an ester of formula CH2=CxCOSR where X is H or a lower alkyl group and R is a monovalent hydrocarbon radical.  The preferred ester is tert.-octyl thioacrylate, other thioacrylates specified include the amyl, lauryl, cetyl, amyl phenyl, isoheptyl, cyclohexyl and ethylbenzyl esters. Thiomethacrylates listed include the amyl, isoheptyl, octyl, decyl, lauryl, cetyl, octadecyl, cyclohexyl, ethyl cyclohexyl, isopropyl, n-butyl, isobutyl, t-butyl, amylphenyl, benzyl, butyl-phenyl, isopropylcresyl and ethylene glycol esters, esters of alcohols derived from paraffin wax and ethylene glycol dithiomethacrylate. The esters may be prepared by reacting b -chloropropionyl chloride with octyl mercaptan (see Group IV (b)).  The oily ester is polymerized by known methods, e.g. by merely removing the inhibitor, but preferably the ester is heated, e.g. at 50-200 DEG  C. with or without the addition of a polymerization catalyst, e.g. benzoyl or acetyl peroxide.  If desired, polymerization may be carried out in emulsion.  Mixtures of two or more different esters may be copolymerized or one or more may be copolymerized with one or more esters of acrylic or methacrylic acids, listed are copolymers of octyl thioacrylate with ethyl thioacrylate or lauryl methacrylate and a tripolymer of octyl thioacrylate, ethyl methacrylate and lauryl methacrylate. The polymers produced range from viscous liquids or tacky solids to hard resinous or rubbery solids, and are suitable additives to lubricating oils (see Group III), e.g. paraffinic, naphthenic or mixed base oils, and to paraffin wax, petrolatum, asphalt, diesel fuels, kerosene and gasoline.  They may also be used for thickening or plasticising vegetable or animal oils, resins, gums and rubber or synthetic rubber, and may be admixed with fillers, e.g. clay, sand, silica dust, carbon black and chalk and with pigments, dyes, antioxidants and corrosion inhibitors.ALSO:The preparation is described of esters of thioacrylic acid and its homologues of formula CH2=CXCOSR where X is H or a lower alkyl group and R is a monovalent hydrocarbon radical.  The preferred esters is tert. octyl thioacrylate, other thioacrylates specified include the amyl, lauryl, cetyl, amyl phenyl, isoheptyl, cyclohexyl and ethylbenzyl esters. Thiomethacrylates listed include the amyl, isoheptyl, octyl, decyl, lauryl, cetyl octadecyl, cyclohexyl, ethyl cyclohexyl, isopropyl, n-butyl, isobutyl, t-butyl, amylphenyl, benzyl, butylphenyl, isopropyl-cresyl and ethylene glycol esters, esters of alcohols derived from paraffin wax and ethylene glycol dithiomethacrylate. The esters may be prepared in any manner, in an example octyl thioacrylate is obtained by reacting b -chloropropionyl chloride with octyl mercaptan and the octyl b -chloropropionate produced dehydrohalogenated with a suitable base, e.g. diethyl aniline, to give octyl thioacrylate.  A polymerization inhibitor, e.g. hydroquinone, is added with the base.  The oily esters produced may be polymerized (see Group IV (a)).