| 摘要 |
PURPOSE:To obtain a polyurethane sponge having fine interconnected pores easily and stably at good efficiency by adding a salt which can absorb water of crystallization and a water-soluble salt to an aqueous dispersion of a polyurethane elastomer, casting the mixture, drying and heat-treating it, and washing the casting with water. CONSTITUTION:A salt which can absorb water of crystallization is added to an aqueous dispersion of a polyurethane elastomer to absorb the water under agitation, and a water-soluble salt is added to the dispersion. The resulting mixture is kneaded to form a semifluid, which is cast into a frame mold, dried, heat-treated, and washed with water to remove the above salts to thereby obtain the purpose porous object. As a result a polyurethane sponge having a fine pore diameter and interconnected pores even at a porosity of 90vol.% or below, which can be very difficultly obtained by the conventional foaming process, can be obtained. |
