Hard rubber compsn. with high ozone resistance etc.

摘要

Rubber compsns. (I) with a high degree of hardness contain (1) 10-60 wt.% of a copolymer of ethylene, alpha-olefin and non-conjugated diene with a Mooney viscosity ML1+4 (100 deg C) (MV) of not more than 45 (component A), (2) 15-60 wt.% of a styrene-butadiene copolymer (SBR) or a mixt. of SBR and polystyrene contg. 50-95 wt.% styrene units (component B), (3) 15-60 wt.% polybutadiene with a mean Mn of 700-4000 or a trans-polyoctenamer rubber (component C), and (4) 3-25 pts. wt. sulphur to 100 pts. wt. (A + B + C). Also claimed is hard rubber obtd. by vulcanisation of (I) and a composite material in which the surface layer of the core consists of this vulcanised rubber.