Ozone-resistant rubber compsn. - contains EPDM rubber with specified mooney viscosity and iodine, no. and a diene-based rubber

摘要

Rubber compsn. (I) contains 2 rubber components comprising (a) an ethylene/propylene/diene terpolymer (EPDM) with Mooney viscosity (ML1+4(100 deg.C)) above 110 and iodine no. 25-35, and (b) a diene-based rubber, i.e. natural rubber (NR), isoprene rubber (IR), styrene/butadiene rubber (SBR), butadiene rubber (BR), butyl rubber (IIR) or butyl-halogen rubber (halo-IIR). Amts. are 30-60 wt.% (a) and 70-40 wt.% (b) w.r.t. total rubber. (a) contains 8.5-12.5 wt.% diene, pref. ethylidene-norbornene (ENB), ethylene-norbornene (MNB), dicyclopentadiene (DCP) or 1,4-hexadiene (1,4 HD). USE/ADVANTAGE - (I) is an improved rubber compsn. with enhanced resistance to ozone and oxygen, it therefore has high resistance to flexural cracking and is useful esp. for the sidewalls of car tyres