Runflat tire with sidewall component containing high strength glass bubbles

Abstract

A pneumatic runflat tire comprising a sidewall component comprising a rubber composition comprising at least one diene based elastomer and from about 1 to about 40 phr of glass bubbles having a crush strength of at least 10,000 psi as measured by ASTM D3102-78 in glycerol.

1 . A pneumatic runflat tire comprising at least one carcass reinforcing ply, at least one pair of sidewall wedge inserts, and a belt reinforcing structure, the belt reinforcing structure comprising at least a pair of cross cord belt reinforcing plies, the tire being characterized by a porous elastomeric layer located radially outward of the at least one carcass reinforcing ply and radially inward of the radially outermost cross cord belt reinforcing ply, wherein the porous elastomeric layer has a radial thickness T C  at least equal to 50% of and at most three times the radial thickness T B , T P  of either an adjacent carcass reinforcing ply or an adjacent cross cord belt reinforcing ply, the sidewall wedge inserts comprising a rubber composition comprising at least one diene based elastomer and from about 1 to about 40 phr of glass bubbles having a crush strength of at least 10,000 psi as measured by ASTM D3102-78 in glycerol. 
   
   
       2 . The pneumatic runflat tire of  claim 1  wherein said glass bubbles have a crush strength of at least 18,000 psi as measured by ASTM D3102-78 in glycerol. 
   
   
       3 . The pneumatic runflat tire of  claim 1  wherein said glass bubbles are present in a concentration range of from 3 to 30 phr. 
   
   
       4 . The pneumatic runflat tire of  claim 1  wherein said glass bubbles have a particle size distribution of 10 percent by weight of 15 microns or less, 50 percent by weight of 30 microns or less, 90 percent by weight of 55 microns or less, and 95 percent by weight of 65 microns or less. 
   
   
       5 . The pneumatic runflat tire of  claim 1  wherein said glass bubbles have a particle size distribution of 10 percent by weight of 11 microns or less, 50 percent by weight of 30 microns or less, 90 percent by weight of 50 microns or less, and 95 percent by weight of 60 microns or less. 
   
   
       6 . The pneumatic runflat tire of  claim 1  wherein said glass bubbles have 1 percent or less by weight of particles with a size greater than 149 microns. 
   
   
       7 . (canceled) 
   
   
       8 . (canceled)