Patent ID: 8551201

Claim:
A polyurethane chemical mechanical polishing pad derived from a polyether/polyester based prepolymer reaction mixture, comprising: (a) toluene diisocyanate (TDI)-terminated polytetramethylene ether glycol based prepolymer in an amount of about 60-80 weight percent (wt %) based on the total weight of prepolymer mixture; (b) toluene diisocyanate (TDI)-terminated ethylene adipate polyester prepolymer in an amount of about 40-20 weight percent (wt %), wherein the weight percent based on the total weight of prepolymer mixture; (c) an effective amount of surfactant and curative, respectively, and (d) a foaming agent introduced into the reaction mixture to form said polishing pad, wherein the resulting polishing pad has a density ranging from about 0.6 to about 0.95 g/cc; wherein the curative is selected from the group consisting of 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline), dimethylthiotoluenediamine, trimethyleneglycol di-p-aminobenzoate, polytetramethyleneoxide di-p-aminobenzoate, polytetramethyleneoxide mono-p-aminobenzoate, polypropyleneoxide di-p-aminobenzoate, polypropyleneoxide mono-p-aminobenzoate, 1,2-bis(2-aminophenylthio)ethane, 4,4′-methylene-bis-aniline, diethyltoluenediamine, 5-tert-butyl-2,4- and 3-tert-butyl-2,6-toluenediamine, 5-tert-amyl-2,4- and 3-tert-amyl-2,6-toluenediamine, chlorotoluenediamine, bis-(alkylthio) aromatic diamines, a mixture of 3,5-bis(methylthio)-2,6-toluenediamine and 3,5-bis(methylthio)-2,4-toluenediamine, a mixture of 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine and combinations thereof.