GB644022A - Improvements in or relating to method of preparing rubbery vulcanizable polymeric materials - Google Patents

Abstract

An aqueous dispersion of a rubbery copolymer containing 30-90 per cent of a butadiene-1 : 3-hydrocarbon and 70-10 per cent of a compound containing a single olefin linkage is mixed with an aqueous dispersion of a resinous polymeric material containing at least 80 per cent of a compound having a single olefin linkage, at least 50 per cent of which is an alkyl ester or nitrile of an a -methylene aliphatic carboxylic acid or an aryl compound having an external carbon atom which links the aromatic nucleus to a methylene group, the amount of the rubbery copolymer exceeding that of the resin, the mixture then being coagulated. The rubbery copolymers may be prepared in aqueous emulsion in the presence of soaps of fatty acids or hydrogenated or dehydrogenated rosin acids, alkyl sulphates, alkaryl sulphonates, amines, peroxides, persulphates, heavy metal salts and complexes, aliphatic aldehydes, mercaptans and dialkyl dixanthogens, the process being stopped by phenyl beta-naphthylamine or hydroquinone. As monomers, butadiene, isoprene, dimethyl butadiene, piperylene, styrene, p-methoxystyrene, bromo-, chloro- and methyl-styrenes, vinyl naphthalene, acrylo-, methacrylo-, ethacrylo- and chloro-acrylo-nitriles, methyl, ethyl and isobutyl methacrylates, methyl, propyl and butyl acrylates, methyl alpha-chloro acrylate, acrylamide and methacrylamide, N : N-diethyl acrylamide, diethyl fumarate, diethyl chloromaleate, vinylidene chloride, methyl vinyl ketone, methyl isopropenyl ketone, vinyl pyridines, vinyl furane, carbazole, acetate, methyl ether, and isobutylene and ethylene are specified. The resin dispersion may also be prepared by polymerization in aqueous emulsion in the presence of the emulsifiers, catalysts and promotors as set out above, and modifiers such as ethylene dichloride, but may be prepared by dispersing a polymer in water. Mono-olefinic compounds specified are those set out above, p-cyano styrene, maleic acid and anhydride, and as compounds having more than one double bond the butadiene compounds set out above, cyclopentadiene, chloroprene, cyanobutadiene, divinyl benzene, dimethallyl, diallyl maleate, oxalate, ketone and ether, allyl cinnamate, di-(2-chloroallyl)-adipate, trimethallyl phosphate. The dicinnamate of 1,4-dioxanediol-2,3, allyl methacrylate, methallyl acrylate, 2-chloro allyl crotonate, vinyl crotonate, and ethylene glycol dimethacrylate are specified. The coagulation may be performed by mixing one dispersion with negative particles with the other with positive particles, or flowing together a liquid coagulant and the mixed dispersions, or dipping a form coated with a coagulant into the mixed dispersion. Plasticizers, pigments, fillers, stabilizers, anti-oxidants, and vulcanizing agents may be added to either of the dispersions or the mixed dispersion which may be dried to give a film. The product may be vulcanized by heating with zinc oxide, litharge, soft coal tar, fatty acids, benzothiazyl-2-monocyclohexyl sulphenamide and sulphur.ALSO:An aqueous dispersion of a rubbery copolymer containing 30-90 per cent of a butadiene 1 : 3-hydrocarbon and 70-10 per cent of a compound containing a single olefin linkage is mixed with an aqueous dispersion of a resinous polymeric material containing at least 80 per cent of a compound having a single olefin linkage, at least 50 per cent of which is an alkyl ester or nitrile of an a -methylene aliphatic carboxylic acid or an aryl compound having an external carbon atom which links the aromatic nucleus to a methylene group, the amount of the rubbery copolymer exceeding that of the resin, the mixture then being coagulated. Butadiene, isoprene, dimethyl butadiene, and piperylene are specified as butadiene hydrocarbons. Compounds specified as having a single olefin linkage are styrene, p-methoxy styrene, bromo-, chloro- and methylstyrenes, vinyl naphthalene, methacrylo-, ethyacrylo- and chloroacrylo-nitriles, various acrylates, methacrylates and chloracrylates, acrylo-and methacrylo-amides, diethyl fumarate, diethyl chloromaleate, vinylidene chloride, vinyl ketones, ethers, pyridines, acetate, furane, isobutylene and ethylene. These compounds may be used in preparing the resinous polymeric material with or without such monomers as the butadiene hydrocarbons set out above, cyclopentadiene, chloroprene, cyano butadiene, dimethallyl, divinyl benzene, allyl and methallyl esters, ketones and ethers, vinyl crotonate, and ethylene glycol dimethacrylate. The coagulation may be carried out by mere mixing of dispersions having oppositely charged particles, flowing together a coagulant and the dispersions, or dipping a form coated with a coagulant into the mixed dispersion. Plasticizers, pigments, fillers, stabilizers, anti-oxidants and vulcanizing agents may be added to either of the dispersions before mixing or to the mixture. Vulcanization may be effected by heating with zinc oxide, litharge, sulphur, soft coal tar and an accelerator.