GB670394A - Elastomer-resin compositions - Google Patents

Abstract

A composition comprises (1) a copolymer of 35-48 per cent acrylonitrile and from 65 to 52 per cent of butadiene-1,3; (2) a copolymer of from 18 to 26 per cent acrylonitrile and from 82 to 74 per cent of butadiene-1,3; and (3) a copolymer of from 50 to 85 per cent styrene and from 50 to 15 per cent acrylonitrile, (1) and (2) each being present in the proportions of from 25 to 75 per cent of the sum of (1) and (2), and (3) being present in an amount ranging from 50 to 90 per cent of the sum of (1), (2) and (3) and optionally (1) and (2) may have a content of from 30 to 50 per cent of a toluene-insoluble "B" gel, i.e. the ratio of the weight of the insoluble dried product, remaining after extracting a sample with toluene, to the weight of the original sample. The composition may be made by milling a mixture of (1) and (2), optionally in the presence of a heat stabilizer, e.g. mono- and di-heptyl diphenylamines, 2,5-ditertiary-butyl para cresol, and phenyl beta-naphthylamine, at a temperature of from 280 DEG to 340 DEG F. until the copolymers have the above "B" gel content and then incorporating (3). The composition may include fillers, plasticizers, e.g. dibutyl sebacate and dioctyl phthalate and vulcanizing agents, e.g. sulphur. The composition may be calendered into a continuous thin sheet, several plies piled up and moulded under heat and pressure. Specification 670,393 is referred to.