Patent GB-790882-A (GB)
Title: Method for agglomerating vulcanization accelerators
IPC: C08J3/215
Filed: 1956-02-16
Abstract: Agglomerates for compounding into rubber are prepared by mixing an aqueous slurry of at least one powdered vulcanization accelerator selected from tetramethyl and tetraethyl thiuram disulphides, tetramethyl thiuram monosulphide, zinc dimethyl, diethyl, and dibutyl dithiocarbamates, mercaptobenzothiazole, water-insoluble metallic salts of mercaptobenzothiazole, and benzothiazyl disulphide with a latex stabilized against coagulation by at least one acid-stable emulsifier, and an antioxidant, the latex being selected from natural rubber, polychloroprene, polybutadiene, butadiene-styrene, and butadiene-acrylonitrile latices, the mixture containing at least 4 per cent rubber hydrocarbon by weight of accelerator, coagulating the latex, removing excess water, and forming, drying and collecting agglomerates of the mixture.  The emulsifier or emulsifiers may be selected from (a) anionic emulsifiers, e.g. metal salts of alkyl, aryl and alkyl sulphonates and of alkyl sulphates such as sodium dodecyl naphthalene sulphonate, sodium myristyl or sodium n-decyl sulphonate, and sodium lauryl and sodium myristyl sulphates, and the metal salts of sulphated and sulphonated amides, amines, esters, and ethers such as sodium alkyl phenol ethylene oxide sulphate and the ester of oleic acid and hydroxyethane sodium sulphate; (b) cationic emulsifiers such as the dipolyoxyethylene alkyl tertiary amines, wherein the alkyl group is derived from fatty acids containing from 12 to 18 carbon atoms, and rosin acid substituted amine salts, e.g. dihydroabiethylamine acetate; and (c) non-ionic emulsifiers such as an alkylated aryl polyether alcohol.  The antioxidant may be selected from phenyl beta naphthylamine, styrenated and alkylated phenols and phenyl phosphites.  The latex is preferably coagulated by adding alum or magnesium sulphate, and the agglomerates are preferably formed by extrusion.ALSO:Agglomerates for compounding into rubber are prepared by mixing an aqueous slurry of at least one powdered vulcanization accelerator selected from tetramethyl and tetraethyl thiuram disulphides, tetramethyl thiruam monosulphide, zinc dimethyl, diethyl, and dibutyl dithiocarbamates, mercaptobenzothiazole, water insoluble metallic salts of mercaptobenzothiazole, and benzothiazyl disulphide with a latex stabilized against wagulation by at least one acid-stable emulsifier, and an antioxidant, the latex being selected from natural rubber, polychloroprene, polybutadiene, butadiene-styrene, and butadiene-acrylonitrile latices, the mixture containing at least 4 per cent rubber hydrocarbon by weight of accelerator, coagulating the latex, removing excess water, and forming, drying and collecting agglomerates of the mixture.  The emulsifier or emulsifiers may be selected from (a) anionic emulsifiers, e.g., metal salts of alkyl aryl and alkyl sulphonates and of alkyl sulphates such as sodium dodecyl naphthalene sulphonate, sodium myristyl or sodium n-decyl sulphonate, and sodium lauryl and sodium myrestyl sulphates, and the metal salts of sulphated and sulphonated amides, amines, esters, and ethers such as sodium alkyl phenol ethylene oxide sulphate and the ester of oleic acid and hydroxyethane sodium sulphate (b) cationic emulsifiers such as the dipolyoxyethylene alkyl tertiary amines, wherein the alkyl group is derived from fatty acids containing from 12 to 18 carbon atoms, and rosin acid substituted amine salts, e.g., dihydroabiethylamine acetate, and (c) non-ionic emulsifiers such as an alkylated aryl polyether alcohol.  The antioxidant may be selected from phenyl beta naphthylamine, styrenated and alkylated phenols, and phenyl phosphites.  The latex is preferably coagulated by adding alum or magnesium sulphate, and the agglomerates are preferably formed by extrusion.