GB518719A - Improved rubber-like compositions - Google Patents

Abstract

518,719. Electric cables. HENLEY'S TELEGRAPH-WORKS CO., Ltd., W. T. TUNSTALL, H. A., and EVANS, B. B. Aug. 24, 1938, No. 24909. [Class 36] [Also in Group V] A fire-resistant rubber-like composition is made by vulcanizing a mix comprising neoprene, chlorinated rubber containing not less than 50 per cent. of chlorine, a plasticizer and vulcanization ingredients for the neoprene, the neoprene content of the mix being from 20 to 40 per cent. by weight and the chlorinated rubber content from 10 to 45 per cent. Part, not more than 60 per cent. of the chlorinated rubber may be replaced by an easily decomposable carbonate, e.g., light basic magnesium carbonate, provided the chlorinated rubber content of the mix does not fall below 10 per cent. The preferred plasticizer is a high chlorinated aliphatic hydrocarbon which at ordinary temperatures is either a plastic solid or a very viscous liquid, e.g., chlorinated paraffin wax or chlorinated pitch containing not less than 40 per cent. of chlorine. In an example, a mix comprises 40 per cent. of neoprene, 40 of chlorinated rubber, 8.5 of chlorinated wax and smaller percentages of light calcined magnesia, soft black, zinc oxide resin accelerator and sulphur. The compositions are particularly suitable for use as the neoprene composition in the manufacture of insulated electric conductors, described in Specification 499,908, [Group V], having a composite dielectric comprising an inner layer of vulcanized indiarubber and an outer layer of neoprene composition. Specification 518,718, [Group V], also is referred to.