| abstract |
PROBLEM TO BE SOLVED: To provide a polyurethane foam having a uniform foam structure, which can achieve improvement in flatness and flattening efficiency of a surface to be polished, and extend the use time as compared with the conventional one. Provided is a polyurethane foam that can be usefully used as a polishing pad. A polymer polyol, obtained by reacting an organic diisocyanate and a chain extender, and a content of nitrogen atoms derived from the isocyanate groups of 6 wt% or more, and the dynamic viscoelastic modulus at 50 ° C. E '50 Is 5 × 10 9 dy n / cm 2 or more of a thermoplastic polyurethane, Density 0.5-1.0 g / cm 3 , bubble size 5-2 A polyurethane foam having a thickness of 00 µm and a hardness (JIS-C hardness) of 90 or more. |