| 摘要 |
PROBLEM TO BE SOLVED: To improve the polishing characteristic of a polishing pad and to reduce the dispersion of the polishing characteristic of polishing pads by mixing the specific quantity of water in a mixture of expanded micro hollow spheres, an isocyanate radical end urethane prepolymer and an active hydrogen contained compound to form bubbles by water. SOLUTION: Water is mixed at 0.005-0.5 wt.% in a mixture of expanded micro hollow spheres, an isocyanate radical end urethane prepolymer and an active hydrogen contained compound to form bubbles by water in a molding. The expanded micro hollow spheres are formed by expanding unfoamed heat- expansive micro spheres formed out of thermoplastic resin, by heating. The isocyanate prepolymer is a reactant obtained from polyol or a mixture of polyol and low molecular weight diol, and an organic diisocyanate compound under normally applied reaction conditions. 3, 3'-dichloro-4,4' diaminophenylmethane or the like is used as the active hydrogen contained compound. |
