Patent ID: 6635700
Filing Date: 2003-10-21
Classification: B60C,C08K,C08L

Abstract:
A process for the preparation of a rubber composition consisting essentially of the steps of:A) thermomechanically mixing in a first pass: 1) at least one sulfur vulcanizable rubber; 2) at least one latent mercaptosilane coupling agent; 3) at least one filler; and 4) at least one additional mercaptan, said additional mercaptan being a mercaptosilane selected from the group consisting of compounds of the structure (HSâ€”)rG(â€”SiX3)t; B) bringing the temperature of the first pass mix from about 140Â° C. to about 200Â° C. over a period of 1 to 20 minutes; thereby forming a nonproductive first mixture; C) thermomechanically mixing the nonproductive first mixture in a second pass, optionally in the presence of at least one curing agent, at a temperature of from about 25 to about 100Â° C. for a period of from about 1 to about 30 minutes; thereby forming a productive second mixture; D) adding at least one latent-mercaptosilane activator in step A), step C), or both step A) and step C); E) shaping the second mixture; and then F) curing the second mixture at a temperature between about 130Â° C. to about 200Â° C. for a period of from about 5 to about 60 minutes.