| 摘要 |
The present invention aims to provide a polyurethane foam, suitably usable as a polishing pad, having a uniform foam structure, which can achieve the improvements in the flatness of the surface of polished materials and in the planarization efficiency, and can extend the polishing pad life longer than that of the conventional polyurethane foams. This aim can be achieved by providing a polyurethane foam having a density of 0.5 to 1.0 g/cm<3>, a cell size of 5 to 200 mu m and a hardness ÄJIS-C hardnessÜ of not less than 90, comprising a thermoplastic polyurethane which is obtained by a reaction of a high polymer polyol, an organic diisocyanate and a chain extender, contains not less than 6 % by weight of a nitrogen atom derived from the isocyanate group, and has a storage elastic modulus measured at 50 DEG C ÄE'50Ü of not less than 5 x 10<9> dyn/cm<2>. |
