Vulcanizates containing silica

Abstract From the Canadian patent

A process is provided and the product of that, process, for the production of improved silica filled rubbery vulcanizates in which process a mixture is prepared comprising 100 parts by weight of a vulcanizable hydrocarbyl polymer containing hydroxyl groups, about 5 to about 100 parts by weight of silica and about 1 to about 10 parts by weight of magnesium oxide, the mixture is subjected to shearing at an elevated temperature, cooled vulcanization, active compounds are incorporated and then vulcanized. Such vulcanizates may be generally used especially where lightcoloured products are desired. - 1 -