PROCESS FOR MIXING BLACK-LOADED BLENDS OF EPDM COPOLYMER WITH POLYCHLOROPRENE AND NATURAL RUBBER

摘要

1346202 Rubber compositions E I DU PONT DE NEMOURS & CO 10 Aug 1971 [10 Aug 1970] 37542/71 Headings C3P and C3Q Vulcanizable compositions are obtained by (1) forming a premix comprising (a) 15-30 parts by weight of a random, linear, elastomeric EPDM copolymer in which the diene is openchain and non-conjugated, (b) 20-35 parts of a mercaptan-modified sol. of a chloroprene polymer and (c) 25-60 parts of a reinforcing carbon black having a surface area of at least 40 mSP2/SP/gm (as measured by electron microscope), and (2) subsequently mixing the premix with 50-60 parts of natural rubber, all of said parts being per 100 parts of total rubbers. In the example the compositions also contain zinc oxide and naphthenic processing oil, and are compounded with conventional vulcanizing agents &c. and cured.