Rockcor, Inc.

Rocket Research Corporation

Gm Global Technolgoy Operations, Inc.

Joel V Van Ornum

Peter L Stang

Jessie T Chiu

A sealant composition particularly suitable for vehicle tires comprising a cured butyl rubber present only in the form of a copolymer having a molecular weight in excess of 100,000 and one or more tackifiers, the tensile strength, elongation and cross-link density of the composition being adjusted to produce the necessary properties for tire sealants.

Thermally stable sealant composition

A carbon reinforced, partially cross-linked butyl rubber matrix sealant composition as described is particularly suitable for use as a self-healing tire puncture sealant. The sealant composition comprises a high average molecular weight butyl rubber and a low average molecular weight butyl rubber in a ratio of high to low molecular weight butyl rubber of between about 20/80 to 60/40, in admixture with a tackifier present in an amount between about 55 and 70 weight % of the composition. A partially hydrogenated block copolymer may be included in the admixture.

Elastomeric sealant composition

A fast gelling method of formulating and applying a curable butyl rubber sealant composition which composition is cured using a quinoid curing agent and a free radical cross-linking activator. The curing agent and a first portion of the activator are added to the sealant components to produce a base component. If the amount of activator in the first portion is chosen correctly, the base component remains ungelled until the remainder of the activator is added, at which time a very rapid gel takes place. This method is particularly useful where the sealant is a tire sealant and is to be sprayed onto the inner surface of a tire.

Sealant application method

A vehicle tire is disclosed having an internal circumferential layer of self-sealing composition on an internal surface, particularly behind the tire tread. The sealant layer is initially made up of the combination of specific quantities of a high molecular weight curable butyl rubber, a low molecular weight curable butyl rubber, a liquid polybutylene tackifier, a partially hydrogenated block copolymer of styrene and a conjugated diene, carbon black and suitable curing agents for the butyl rubber components. When cured, this sealant layer effectively heals most punctures one-quarter inch in diameter or less in a vehicle tire at temperatures over the range of about - 20.degree. F. to 270.degree. F. without significant loss of air.

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Kirkland, WA, United States of America

Joel V Van Ornum