Patent ID: 8158691

Claim:
A method for making a latex foam comprising a) compounding into a foamable and vulcanizable latex compound an aqueous reinforced rubber dispersion comprising: i) 58-80 wt-% of base latex polymer particles wherein the base latex polymer is a synthetic styrene/butadiene rubber latex consisting of structural units of styrene and butadiene; and ii) 20-42 wt-% of reinforcing latex polymer particles comprising: 1) 45 to 68.5 wt-% structural units of aromatic vinyl monomers; and 2) 31.5 to 55 wt-% structural units of conjugated diene monomers, wherein the reinforcing latex polymer particles have a single glass transition temperature (T g ) from −25° C. to 28° C. as measured by differential scanning calorimetry (DSC), wherein the weight percentages of the polymer particles are based on the total weight of polymer particles in the rubber dispersion, and wherein the base latex polymer particles have a T g as measured by DSC that is lower than the T g of the reinforcing latex particles; b) foaming the vulcanizable latex compound; c) filling the foam obtained in step b) into a mold of desired shape; d) stabilizing the foam structure; e) vulcanizing the foam; and f) removing the vulcanized latex foam from the mold.