Patent ID: 8240351

Claim:
A pneumatic rubber tire having an integral innerliner wherein said innerliner is a sulfur cured rubber composition comprised of, based on parts by weight per 100 parts by weight rubber (phr), a blend of (A) rubber comprised of at least one of butyl rubber and halobutyl rubber, wherein said halobutyl rubber is comprised of at least one of chlorobutyl rubber and bromobutyl rubber, (B) about 20 to about 60 phr of rubber reinforcing filler consisting of rubber reinforcing carbon black, (C) about 0.5 to about 30 phr of hollow glass microspheres, wherein said hollow glass microspheres have a crush strength in a range of about 34.5 to about 41.4 MPa and have an average diameter in a range of from about 10 to about 50 microns, and (D) an anchoring agent for said hollow glass microspheres having a moiety reactive with hydroxyl groups contained on said glass microspheres and another different moiety interactive with butyl and halobutyl rubber, wherein the moiety of said anchoring agent which is reactive with hydroxyl groups contained on said glass microspheres is composed of siloxy groups and the moiety of said anchoring agent interactive with said rubber is a sulfur based moiety which is interactive with carbon-to-carbon bonds of said rubber.