GB690967A - Improvements in or relating to resinous members - Google Patents

Abstract

Synthetic resin compositions suitable for forming into shaped electrical insulators, preferably by extrusion, comprise (a) a resinous composition comprising as its major components an extrudable thermoplastic resinous polymer of at least one compound having a single H2C=C< group and a compatible plasticizer for the polymer and (b) from 5 to 22 per cent, based on the weight of composition (a), of mica flakes of a fineness such that over 90 per cent by weight passes through a screen having 325 openings per lineal inch. The plasticizer preferably comprises from 20 per cent to 41.2 per cent of the composition (a). The polymer may be polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, polyvinyl butyrate, polyethylene, polyisobutylene, polyvinyl methyl ether, polyvinyl fluoride, poly-1-chloro-1-fluoroethylene, polyvinyl butyral, a copolymer of vinyl chloride and vinylidene chloride, vinyl acetate, or ethylene, or a mixture of two or more of these. The plasticizer may be dioctyl phthalate, tricresyl phosphate, dicapryl phthalate, an acrylonitrile rubber, diethylene glycol bis (n-butyl carbonate), di-2-ethylbutyl-2-ethoxy ethanol succinate, triethylene glycol di-2-ethyl hexoate, methyl phthalyl ethyl glycollate, a partially hydrogenated terphenyl, polyethylene glycol dilaurate, diphenyl mono-o-xenyl phosphate, pentaerythritol tetrapropionate, diethylene glycol monoleate, butyl ricinoleate, butyl benzyl sebacate, triethylene glycol dihydroabietate, or a propylene glycol sebacate. The compositions may also contain calcium stearate, dibutyl tin maleate, white lead, carbon black and up to 10 per cent of a phenolic resin or superpolyamide, and may be used for the production of tubes, tape, sheeting, wire coatings and rods.