Patent GB-1021533-A (GB)
Title: Copolymers
IPC: F02B3/06
Filed: 1963-03-21
Abstract: Dispersant properties are conferred upon natural and synthetic oils by the addition thereto of graft copolymers composed of a base polymer at least 50% by weight of which is derived from at least one C8-C24 alkyl acrylate or methacrylate and having grafted thereon units from at least one of vinyl acetate, propionate and butyrate, the graft copolymer containing 25 to 45% of grafted vinyl ester (see Division C3).  The oils to which the graft copolymers are added may be mineral lubricating oils, diesters, polyethers, silicate esters, phosphates, silicone fluids, fuel oils, diesel fuel and gasolines. Other additives which may be present in the oils are tertiary alkylamines, 4,41 - methylenebis(2,6 - di - tert. - butylphenol), trialkyl phenols, tris(dimethylaminomethyl)-phenol, phenoltriazine, phenylnaphthylamines, zinc, barium and nickel dialkyldithiophosphates, zinc dicyclohexyldithiophosphate, and diphenyldithiophosphate, alkaline earth metal petroleum, alkylbenzene and naphthalene sulphonates, alkaline earth metal phenylstearates and salts of polyphenyl sulphides and alkylphenol-formaldehyde condensates, aluminium naphthenate, phosphate esters, liquid silicones, nonylphenoxypolyethoxyethanols, alkenylsuccinic anhydrides, sulphurized sperm oil and terpenes, polyisobutylene and copolymers of alkyl methacrylates with each other and with comonomers such as vinylpyridines, N-vinyl-2-pyrrolidone and dimethylamino ethyl and alkoxypolyethoxyethyl methacrylates.  The examples describe the addition to lubricating oils of graft copolymers derived from vinyl esters and base polymers of (1) mixed decyl, dodecyl and tetradecyl methacrylates, (2 and 3) lauryl-myristyl methacrylate, (4) laury-myristyl and cetyl-stearyl methacrylates and methyl acrylate, (5) cetyl-stearyl methacrylate and the methacrylate of a lauryl alcohol initiated polyethylene glycol, (6) lauryl-myristyl and cetyl-stearyl methacrylates and di-(lauryl-myristyl)-fumarate, (7) lauryl-myristyl and cetyl-stearyl methacrylates, (8) as in (7) with the addition of styrene, (9) lauryl acrylate, and (10) lauryl-myristyl methacrylate and maleic anhydride.ALSO:Oil-soluble graft copolymers are made by (A) forming a polymerizing mixture of (1) monoethylenic monomer and (2) a base polymer at least 50% by weight of which is derived from at least one C8-C24 alkyl acrylate or methacrylate, the base polymer being present in an amount of more than 50% by weight of the polymerizing mixture, then (B) adding to the mixture vinyl acetate, propionate and/or butyrate and continuing polymerization under the influence of a free radical to produce a graft copolymer containing 25 to 45% by weight of polymerized vinyl ester.  The polymerizing monomer-polymer mixture is preferably formed by the partial polymerization of the C8-C24 alkyl acrylate or methacrylate, which may contain other monomers such as maleic, fumeric, and itaconic acids and alkyl esters thereof, maleic anhydride, acrylic and methacrylic acids and amides and nitriles thereof, maleic half amide, vinyl alkyl ethers and thioethers, styrene, alkyl styrenes and esters of acrylic and methacrylic acids with alcohols other than C8-C24 alkanols. Polymerization initiators used are organic azo compounds and organic peroxides, which latter may be used in conjunction with quaternary ammonium compounds as activators. Polymerization may be carried out in bulk or in solution in an organic solvent.  The resulting graft copolymers are added to oils to impart dispersancy thereto.  The examples describe polymerizing vinyl esters in partially polymerized (1) mixed decyl, dodecyl and tetradecyl methacrylates, (2) and (3) lauryl-myristyl methacrylate, (4) lauryl-myristyl and cetyl-stearyl methacrylates and methyl acrylate, (5) cetyl-stearyl methacrylate and the methacrylate of a lauryl alcohol initiated polyethylene glycol, (6) lauryl-myristyl and cetyl-stearyl methacrylates and di-(lauryl-myristyl) fumarate, (7) lauryl-myristyl and cetyl-stearyl methacrylates, (8) as in (7) with the addition of styrene, (9) lauryl acrylate, and (10) lauryl-myristyl methacrylate and maleic anhydride.