GB499747A - Process for the manufacture of vulcanised coatings - Google Patents

Abstract

Vulcanized coatings or impregnations are produced by incorporating zinc oxide in an aqueous suspension obtained by causing a water-soluble inorganic polysulphide to react with an organic polyhalogenated compound in the presence of finely divided barium sulphate, coating or impregnating materials of any kind with the suspension, and then subjecting the impregnated or coated material to a high temperature suitable for vulcanization, e.g. 100 to 160 DEG C. Polyhalogenated compounds specified are ethylenedichloride, 1.3-dichloropropane, p-xylylene dichloride, b -b 1-dichlorodiethylether, b -b 1-dichlorodiethyl sulphide, di-(ethylenechlorhydrin)-formaldehyde acetal and the products of the condensation of aldehydes and chlorine-containing alcohols. Prior to the incorporation of the zinc oxide, the plastics may be subjected to the action of sulphur-stripping p substances such as sodium hydroxide or sodium sulphide. Vulcanization accelerators, e.g. substituted dithiocarbamic acids, anti-ageing agents such as N-phenyl-b -naphthylamine or the condensation products of aldol and naphthylamines, filling agents, e.g. carbon black, chalk and talcum, and wetting or dispersing agents, e.g. condensation products of formaldehyde and naphthalene sulphonic acids, may be incorporated in the suspension. When a filling agent is used, a dissolving or swelling agent for the sulphur-containing plastic such as benzene, ethylene dichloride, or 1.1.2-trichloroethane may be added to the suspension before or after the addition of the zinc oxide or in admixture therewith. The material to be coated or impregnated, e.g. textiles, wood or metals, may be pretreated with a wetting agent. In examples (1) to (5), an aqueous suspension of a plastic obtained by reacting sodium tetrasulphide and di-(ethylenechlorhydrin)-formaldehyde acetal in the presence of barium sulphate is mixed with zinc oxide, a dispersing agent consisting of an aqueous suspension of the sodium salt of the condensation product of b -naphthalene sulphonic acid with formaldehyde and (1) tetramethylthiuram disulphide, (2) dibenzothiazyl disulphide, (3) dibenzothiazyl disulphide and mercaptobenzimidazole, (4) tetramethylthiuram disulphide, carbon black and 1.1.2-trichlorethane, or (5) tetramethylthiuram disulphide, carbon black, ethylene chloride and water. In example (6), an aqueous suspension of a condensation product of b -b 1-dichlorodiethylether and sodium tetrasulphide prepared in the presence of barium sulphate is mixed with zinc oxide, dibenzothiazyl disulphide and the above-mentioned dispersing agent. The suspensions thus obtained, which may be diluted with water, are applied to the materials to be coated or impregnated and vulcanized by heating. Specifications 354,394, 438,965, 450,218, 458,781, and 460,139 are referred to.