摘要 |
<p>A polyester-polyol being liquid at 40 °C and having a viscosity of not more than 10,000 mPa.s at 60 °C, prepared by polycondensation of an acid component including at least one phthalic acid component selected from phthalic anhydride and o-phthalic acid, and an aliphatic polybasic acid, with a polyhydric alcohol; a process for preparing a polyurethane foam including reacting a polyisocyanate component with a polyol component including the polyester-polyol; a process for preparing an isocyanate prepolymer from a polyisocyanate component and a polyol component including the polyester-polyol; and a process for preparing a polyurethane foam including reacting an isocyanate prepolymer prepared from a polyisocyanate component and a polyol component including the polyester-polyol, with a polyol component. The resulting polyurethane foam shows remarkably improved physical properties such as tensile strength and tear strength, while having low density, acceptable appearance and texture.</p> |