Patent ID: 7129279

Claim:
A lightweight tire support, said tire support comprising a microcellular polyurethane polymer having a density of less than 1 g/cc and the microcellular polyurethane polymer comprises: (A) a hard-segment polymer comprising a reaction product of an at least one first isocyanate and an at least one chain extender; (B) a soft-segment polymer comprising a reaction product of an at least one second isocyanate and an at least one polyol, said at least one second isocyanate being the same as or different from said at least one first isocyanate and said polyol having a functionality of at least 2.5; and (C) said hard-segment polymer and said soft-segment polymer being present in an amount effective for providing said tire support with load-bearing capability and temperature stability; and the hard-segment polymer is in an amount of at least 25 weight percent and no greater than 45 weight percent based on the total weight of the composition.