SILICA-FILLED RUBBER COMPOSITIONS CONTAINING A MIXTURE OF DITHIODIPROPIONIC ACID, TRITHIODIPROPIONIC ACID AND TETRATHIODIPROPIONIC ACID

摘要

A method is disclosed for improving the physicalproperties of a silica-filled rubber composition whichcomprises mixing(i) 100 parts by weight of at least onsulfur vulcanizable elastomer selected fromconjugated diene homopolymers and copolymers,natural rubber and copolymers of at least oneconjugated diene and aromatic vinyl compound;(ii) 10 to 250 phr of silica; and(iii) .05 to 10 phr of a mixture ofdithiodipropionic acid, trithiodipropionic acidand tetrathiodipropionic acid.Addition of the mixture of dithiodipropionic acid,trithiodipropionic acid and tetrathiodipropionic acidto silica-reinforced sulfur vulcanizable rubberimproves the vulcanizate properties.