Patent ID: 8293049
Filing Date: 2012-10-23
Classification: B29C,B29D,B29L,B60C,C08K,Y10T

Abstract:
1. A method of preparing a pneumatic tire having a puncture sealing ability as an assembly of components comprised of an outer circumferential rubber tread, rubber carcass supporting said tread and an inner rubber tire innerliner layer, wherein said method comprises: (A) positioning a layer of uncured butyl rubber based composition as a sealant precursor between said innerliner and rubber carcass, wherein said sealant precursor butyl rubber based composition is prepared by blending: (B) curing said assembly of components in a suitable mold at an elevated temperature to form a pneumatic tire and to cause said butyl rubber of said sealant precursor to partially depolymerize said butyl rubber by said combination of said 4,4-di-(tertiary butylperoxy) valerate and dicumyl peroxide and thereby form a built-in sealant layer within said tire wherein said butyl rubber depolymerization is initiated by said 4,4-di(tertiary butylperoxy) valerate and propagated by said dicumyl peroxide and 4,4-di(tertiary butylperoxy) valerate.