Patent GB-610728-A (GB)
Title: Improvements in or relating to synthetic rubber compositions, and method of preparing same
IPC: C08J3/215
Filed: 1945-12-28
Abstract: Synthetic rubber compositions containing a water-insoluble metallic silicate are obtained by mixing an aqueous solution of a water-soluble silicate and the latex obtained by copolymerizing in aqueous emulsion a mixture of a butadiene-1,3 and a compound containing a single olefinic bond and then adding the resultant mixture to an aqueous solution of a salt of a metal which forms insoluble silicates in a quantity in excess of that required to react with the soluble silicate whereby simultaneous precipitation of water-insoluble silicate and coagulation of the said latex occur to form an aqueous slurry of synthetic rubber coagulum in crumb-like form and containing water-insoluble silicate intimately associated with the synthetic rubber.  The preferred silicate is that of calcium obtained by the interaction of calcium chloride and sodium silicate, though barium, strontium, magnesium, and aluminium silicates may also be used.  The latex may be prepared by copolymerizing butadiene-1,3, isoprene, 2,3-, dimethyl butadiene-1,3, piperylene, or 3-methylpentadiene-1,3 with styrene, vinyl naphthalene, metachloro styrene, 3,5-dichlorostyrene, p-methoxystyrene, vinyl pyridine, acrylonitrile, alphachloro acrylonitrile methyl acrylate, methyl methacrylate, methylacrylomide, methyl vinyl ketone, diethyl fumarate, ethylene, or isobutylene in the presence of a fatty acid soap, a resin acid soap, a water soluble alkyl sulphate or alkaryl sulphonate or dodecyl amine hydrochloride.  After coagulation the crumb rubber may be compacted and sheeted after adding heptylated diphenylamine, phenyl beta-naphthylamine, hydroquinone or beta-naphthol and zinc oxide, stearic acid, benzothiazyl disulphide and sulphur and the mix vulcanized.ALSO:Synthetic rubber compositions containing a water-insoluble metallic silicate are obtained by mixing an aqueous solution of a water-soluble silicate and the latex obtained by copolymerizing in aqueous emulsion a mixture of a butadiene-1, 3 and a compound containing a single olefinic bond and then adding the resultant mixture to an aqueous solution of a salt of a metal which forms insoluble silicates in a quantity in excess of that required to react with the soluble silicate whereby simultaneous precipitation of water-insoluble silicate and coagulation of the said latex occur to form an aqueous slurry of synthetic rubber coagulum in crumb-like form and containing water-insoluble silicate intimately associated with the synthetic rubber.  The preferred silicate is that of calcium obtained by the interaction of calcium chloride and sodium silicate, though barium, strontium, magnesium, and aluminium silicates may also be used.  The latex may be prepared by copolymerizing butadiene-1, 3, isoprene, 2, 3,- dimethyl butadiene 1, 3, piperylene, or 3-methyl-pentadiene-1, 3 with styrene, vinyl naphthalene, metachloro styrene, 3, 5 dichlorostyrene, p-methoxystyrene, vinyl pyridine, acrylonitrile, alpha-chloro acrylonitrile, methyl acrylate, methyl methacrylate, methylacrylamide, methyl vinyl ketone, diethyl fumarate, ethylene and isobutylene in the presence of a fatty acid soap, a resin acid soap, a water-soluble alkyl sulphate or alkaryl sulphonate or dodecyl amine hydrochloride.  After coagulation the crumb rubber may be compacted and sheeted after adding heptylated diphenylamine, phenyl beta naphthylamine, hydroquinone or beta naphthol and zinc oxide, stearic acid, benzothiazyl disulphide and sulphur and the mix vulcanized.