Patent ID: 6465604
Filing Date: 2002-10-15
Classification: C08K

Abstract:
A vulcanizable composition comprising a sulfur vulcanizable rubber,a sulfur vulcanizing agent an accelerating agent and a hardness stabilization agent comprising a pyrimidine derivative of the formula: where X is S, O or NH, Y is SR3, or OR3, R1 through R3 are the same or different and selected from the group consisting of the substituents alkyl, cycloalkyl, alkylaryl, aryl and aralkyl, hydrogen, halogen, hydroxy, amino, substituted amino, and substituted carbonyl containing groups, R3 may be a radical derived from a carbon based heterocyclic group containing at least one of S or N, or both S and N, and the respective amounts of accelerating agent and hardness stabilization agent being effective to not substantially inhibit vulcanization and to stabilize the hardness property of said rubber upon vulcanization, the amount of accelerating agent in said composition being greater than about 0.6 phr when said rubber is SBR rubber, or at least about 0.5 phr when said rubber is natural rubber, and the amount of hardness stabilization agent being at least about 0.5 phr.