摘要 |
Vulcanized diolefine polymer rubbers, e.g. natural rubber and butadiene-styrene, butadiene-acrylonitrile, butadiene-vinylpyridine and isobutylene-styrene copolymer rubbers, are rendered resistant to ozone cracking by incorporation of 0.5-10 parts of petroleum wax containing at least 60 per cent of microcrystalline wax together with 0.5-5 parts of an N-alkyl - N1 - phenyl - p - phenylenediamine having 2-9 carbon atoms in the alkyl group in 100 parts of the rubber. |