Patent ID: 8242194
Filing Date: 2012-08-14
Classification: C08K

Abstract:
1. A method of preparing a silica reinforcement containing rubber composition with a delayed addition of fatty acid salt processing aid which comprises the sequential steps of, based upon parts by weight per 100 parts by weight rubber (phr): (A) preparing a rubber mixture by mixing, in an internal rubber mixer at a temperature in a range of from about 140° C. to about 190° C.: (B) mixing about 45 to about 20 percent of said fatty acid with said rubber mixture in a subsequent mixing step in a separate internal rubber mixer, thereby forming a resultant rubber composition; wherein said fatty acid is comprised of stearic acid and at least one of palmitic acid and oleic acid; and (C) thereafter blending, at a temperature in a range of from about 100° C. to about 120° C., elemental sulfur and at least one sulfur vulcanization accelerator with the resultant rubber composition in an internal rubber mixer.