GB939542A - Rubber compositions - Google Patents

Abstract

Vulcanizates which do not darken on exposure to light are obtained from rubber mixes containing as plasticizer the product obtained by the reaction in which an aromatic hydrocarbon is alkylated with an alkyl group having 8 or more carbon atoms. The alkylated product may be blended with the rubber in latex form and the blend then coagulated. The alkylated product may be incorporated to the extent of up 40% of the rubber. The products generally have a boiling point above 250 DEG C. and are obtained by alkylation of unsubstituted or substituted aromatic hydrocarbons, e.g. benzene, naphthalene, diphenyl, toluene, a xylene, a methyl naphthalene, in the presence of sulphuric acid, hydrofluoric acid, hydrobromic acid, aluminium trichloride, zinc chloride or boron trifluoride, by olefines having 8-18 carbon atoms such as polymerized alkenes, e.g. propylene tetramer, or those obtained by cracking hydrocarbon mixtures such as paraffin wax or heavy oil extract, or by suitable alkyl chlorides, e.g. those obtained by chlorinating refined kerosine. The rubbers concerned are natural rubber, rubbery polymers of butadiene and isoprene, and copolymers of butadiene and isoprene with styrene, acrylonitrile and isobutylene, and include the cold synthetic rubbers produced by the use of redox initiators at temperatures below 50 DEG C., e.g. 0 DEG C. Specification 737,086 is referred to.