Increasing natural rubber green strength and adhesion - by adding maleic anhydride adduct with liq. polyisoprene having high cis content

摘要

Rubber compsn. contains 5-45 wt. % modified liq. rubber, (I) and 95-55 wt. % natural rubber. (I) is an adduct of maleic anhydride, or a deriv. thereof, with a liq. polyisoprene rubber having a cis-1,4-content >=70 (>=80) % and mol. wt. 8000-100 000 (15000-55000). Maleic anhydride or deriv. proportion is 0.1-15 (0.5-10) mol % per isoprene unit in liq. polyisoprene rubber. The compsns. are used in stee-reinforced radial tyre-, conveyor belt and hose-prodn. White filter-contg. compsns. can be used in rubber shoe mfr. Addn. of (I) improves flow and workability in non-vulcanised condition, lowers Mooney viscosity, increases green strength, vulcanisate hardness and vulcanisate adhesion to metals.