Polishing pad and manufacturing method thereof

A polishing pad having a polishing layer made from a polyurethane resin foam, wherein the polyurethane resin foam is a reaction-cured product between an aliphatic and/or alicyclic isocyanate-terminated prepolymer and a chain extender containing at least one kind of a halogen free aromatic amine selected from the group consisting of compounds expressed by the following general formulae (3) and (4):

• wherein in the general formula (3), R4 to R7, each independently of the others, H or an alkyl group having 1 to 4 carbon atoms, and R4 to R7 are chosen so that the general formula (3) does not include 4,4′-diamino-3,3′-diethyl-5,5′-dimethyldiphenylmethane, and
• wherein m is 4 and n is an integer from 1 to 5.

A method for manufacturing a polishing pad, comprising mixing a first component containing an isocyanate-terminated prepolymer into a second component containing a chain extender for curing to produce a polyurethane resin foam,

• wherein the mixing comprises adding a silicone-based surfactant into the first component containing isocyanate-terminated prepolymer in the range of from 0.05 to 10 wt % based on the polyurethane resin foam, agitating the first component together with a non-reactive gas to thereby prepare a cell dispersion liquid in which the non-reactive gas is dispersed as fine cells and thereafter mixing the second component containing a chain extender into the cell dispersion liquid for curing to produce a polyurethane resin foam, and the isocyanate-terminated prepolymer is an aliphatic and/or alicyclic isocyanate-terminated prepolymer and the chain extender contains at least one kind of a halogen free aromatic amine selected from the group consisting of compounds expressed by the following general formulae (3) and (4):
• wherein in the general formula (3), R4 to R7, each independently of the others, H or an alkyl group having 1 to 4 carbon atoms, and R4 to R7 are chosen so that the general formula (3) does not include 4,4′-diamino-3,3′-diethyl-5,5′-dimethyldiphenylmethane, and
• wherein m is 4 and n is an integer from 1 to 5.