Elastomer compn contg an ethylene/propylene terpolymer a - halogenated butyl rubber and a highly unsaturated rubber

摘要

Elastomer mixture comprises (a) 15 to 30 weight-% of a terpolymer of ethylene with a C3-10 alpha-olefin and 0.1 to 5 mol-% of a third monomer; (b) 15 to 30% of a halogenated butyl rubber; and (c) 70 to 40% of a highly unsaturated rubber. Despite relatively low proportion of (b), the composition has excellent dynamic resistance to ozone, and long term flexural strength under thermal stress, without impairment of physical properties and static ozone resistance. Loss of adhesive compatibility is minimal. - The third monomer in (a) may be 5-methylene-2-norbornene, dicyclopentadiene, 1,4-hexadiene, 4,7,8,9-tetrahydroindene or 5-ethylidenenorbornene. - Uses are in tyre production.