GB644829A - Curing polymeric materials - Google Patents

Abstract

Chloroprene polymers and interpolymers are cured in admixture with an organic polyisocyanate-modified polyester, for example, by heating with magnesium oxide or zinc oxide. Specified as starting materials are glycols: ethylene, 1 : 2 - propylene, diethylene, trimethylene, pentamethylene, hexamethylene, decamethylene, and dodecamethylene glycols 1 : 12-octadecanediol, and pentaglycol; carboxylic acids: malonic, succinic, glutaric, adipic, b -methylapidic, pimeleic, suberic, azelaic, sebacic, undecanedioic, brassylic, isophthalic, terephthalic, hexahydroterephthalic, p-phenylene diacetic acids, and acetone dicarboxylic acid; polyisocyanates: ethylene, tri-methylene, tetramethylene, hexamethylene, decamethylene, p-phenylene, m-phenylene, and naphthalene di-isocyanates, benzene 1 : 3 : 5-, toluene 2 : 4 : 6-, ethylbenzene 2 : 4 : 6-, triphenylmethane 4 : 41 : 411 -, and diphenyl-2 : 4 : 41-tri-isocyanates. Preferably the modified polyester has an intrinsic viscosity in chloroform solution of more than 0.6. The chloroprene polymer and modified polyester may be admixed either by milling or in solution in chloroform, carbon tetrachloride, trichlorethylene, acetone, benzene, or toluene, or the unmodified polyester may be admixed with the polychloroprene and then reacted with the polyisocyanate. Before curing there may be mixed with the compositions carbon black, iron oxides, clay, asbestos, blanc fixe, lithopone, pigments, plasticizers, e.g. tricresyl phosphate, dibutyl phthalate, butyl phthalyl butyl glycollate, N-alkyl-toluene sulphonamides, and stabilizers, e.g. hydroquinone, N : N1-hexamethylene - bis - o - hydroxy - benzamide, N-phenyl - a or b - naphthylamine, and a : a bis - (2 - hydroxy - 3 : 5 - dimethylphenyl)-butane. The products may be used as gaskets, diaphragms for pumps, fuel containers, balls for games, tyres, protective clothing, leather cloth, floor coverings and in coating compositions. Examples describe (1) milling together polyethylene sebacate modified by hexamethylene di-isocyanate and a chloroprene polymer, with and without the addition of magnesium oxide and zinc oxide; (2) using an interpolymer of chloroprene and isoprene in processes as in (1).