US Patent 7414080 Polyurethane polishing pad

The polishing pad is suitable for planarizing at least one of semiconductor, optical and magnetic substrates. The polishing pad includes a cast polyurethane polymeric material formed with an isocyanate-terminated reaction product formed from a prepolymer reaction of a prepolymer polyol and a polyfunctional isocyanate. The isocyanate-terminated section product has 4.5 to 8.7 weight percent unreacted NCO; and the isocyanate-terminated reaction product is cured with a curative agent selected from the group comprising curative polyamines, curative polyols, curative alcoholamines and mixtures thereof. The polishing pad contains at least 0.1 volume percent filler or porosity.