Patent ID: 7674344
Filing Date: 2010-03-09
Classification: B29C,B29L,Y10T

Abstract:
1. A process of providing a pneumatic rubber tire having a built-in puncture sealing layer, which comprises: (A) building a tire having a built-in puncture sealing precursor layer of a composition comprised of butyl rubber, organoperoxide, polyethylene glycol and an activating agent for said organoperoxide, wherein said activating agent is a 2,2,6,6-tetra alkyl piperidine hindered amine, and (B) partially depolymerizing said butyl rubber in situ within said puncture sealing precursor layer in said tire with free radicals generated by said organoperoxide, wherein said free radical generation by said organoperoxide is activated and promoted by said activating agent in situ within said puncture sealing layer to thereby more efficiently partially depolymerize said butyl rubber and thereby form said built-in puncture sealing layer, wherein said 2,2,6,6-tetra alkyl piperidine hindered amine is comprised of: wherein said butyl rubber is a copolymer comprised of isobutylene and isoprene and wherein said butyl rubber is comprised of about 0.5 to about 1 percent units derived from isoprene, and correspondingly from about 99 to 99.5, weight percent units derived from isobutylene.