Patent ID: 8779020
Filing Date: 2014-07-15
Classification: B24B,B24D,C08G,C08J

Abstract:
1. A polishing pad comprising a polyurethane resin foam having a fine cell, and containing a polishing layer having a depression and protrusion structure on a polishing surface, wherein the polyurethane resin foam has an Askar D hardness of 45 to 55 degree, a specific gravity of 0.8 to 0.86, and a tensile breaking extension of 120 to 150%, wherein the polyurethane resin foam is a reaction cured body of an isocyanate-terminal prepolymer A, an isocyanate-terminal prepolymer B and a chain extender the isocyanate-terminal prepolymer A comprising a polyol A having a number average molecular weight of 500 to 650 and an isocyanate component, the isocyanate-terminal prepolymer B comprising a polyol B having a number average molecular weight of 900 to 1500 and an isocyanate component, a content ratio of the polyols (polyol A/polyol B) being 20/80˜35/65 (wt %), and an average NCO wt % of each of the isocyanate-terminal prepolymers A and B being 9.8 to 10.5% by weight.