RUBBER TYPE FOAM COMPOSITION FOR OF OUT-SOLE WITH DIMENSIONALSTABILITY AND IMPROVEDABRASION RESISTANCE

A rubber-based foam composition for footwear soles is provided to improve wear resistance, mechanical strength, uniform foaming ratio and dimensional stability, and to prevent defects caused by generation of air scorch during hot press molding. A rubber-based foam composition for footwear soles comprises a blend of rubber with a synthetic resin as a base material, a crosslinking agent, a vulcanization accelerator, a foaming agent and a reinforcing agent. The base material comprises a blend containing 60-90 wt% of at least one rubber selected from natural rubber, butadiene rubber and acrylonitrile-butadiene rubber, and 10-40 wt% of at least one sulfur-crosslinkable thermoplastic resin selected from syndiotactic 1,2-polybutadiene and thermoplastic styrene-butadiene copolymers. The composition comprises 100 parts by weight of the base material, 0.3-1.5 parts by weight of sulfur as a crosslinking agent, 0.05-2.0 parts by weight of a vulcanization accelerator, 4-10 parts by weight of a foaming agent and 10-35 parts by weight of silica as a reinforcing agent.