MODIFYING THERMOPLASTIC VULCANIZATES USING RANDOM PROPYLENE COPOLYMERS Russian patent published in 2004 - IPC

FIELD: rubber industry. SUBSTANCE: starting composition contains 20-85 wt of parts rubber, which is dynamically vulcanized in presence of curing substance for rubbers and 15-80 wt parts of combination including 2 to 2000 parts of random propylene copolymer with maximum melting point from 25 to 105 C per 100 parts of semicrystalline polypropylene with melting point at least 120 C. Melting heat of random propylene copolymer is below 75 kJ/g and that of semicrystalline polypropylene above 80 kJ/g. Rubber is selected from ethylene/propylene/diene natural rubber, butyl rubber, halobutyl rubber, halogenated rubber copolymer of n-alkylstyrene, and other olefin rubbers and their combinations. Method of preparing thermoplastic vulcanizate composition involves mixing, in any order, the two composition components and subsequent dynamic vulcanization of rubber in presence of curing agent. Invention can be used when manufacturing a variety of articles such as tires, hoses, bands, sealing inserts, moldings, and molded products. EFFECT: increased relative elongation on rupture and impact strength. 16 cl, 13 tbl