Patent ID: 7528181

Claim:
An uncured dienic rubber composition, comprising: a dienic rubber; one or more ultra-accelerator rubber curing agents; and microencapsulated sulfur and free sulfur, the microencapsulated sulfur being microencapsulated in a material having a thermal transition temperature between a processing temperature and a curin temperature of the rubber composition, wherein a difference between t 0 measurements taken isothermally at 125° C. in accordance with ASTM D2084 of a 6 mm thick sample of the rubber composition aged for 28 days at 40° C. and of the rubber composition unaged, is less than a +10 percent change in the t 0 measurement of the unaged rubber composition, wherein the percent change is determined by the equation to [t 0 (aged) −t 0 (unaged) ]* 100 / t 0 (unaged) .