| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foam which is flexible, is excellent in recovery and dimensional stability, and is capable of being re-molten or re-dissolved by selecting a recyclable foam having a specified expansion ratio. SOLUTION: This foam is a recyclable vinyl chloride polymer/polyurethane thermoplastic elastomer foam having an expansion ratio of at least 3. The elastomer can be produced by subjecting to a urethanization reaction a vinyl chloride polymer having a degree of polymerization of, desirably, 1,000-4,000, a polymer polyol having a number-average molecular weight of, desirably, 500-8,000, an isocyanate compound having at least three NCO groups, a plasticizer, and a urethanization catalyst by melt blending under shear. The foam can be produced by kneading the elastomer and a chemical blowing agent, packing the obtained composition into a mold, pressurizing the composition in the mold to melt it under heating to decompose that chemical blowing agent, cooling the mold under pressure, releasing the pressure from the mold, and opening the mold to foam the molding. |
