US Patent 10106662 Thermoplastic poromeric polishing pad

The porous polyurethane polishing pad includes a porous matrix having large pores that extend upward from a base surface and open to an upper surface. The large pores are interconnected with small pores. The porous matrix is a blend of two thermoplastic polymers. The first thermoplastic polyurethane has by molecular percent, 45 to 60 adipic acid, 10 to 30 MDI-ethylene glycol and 15 to 35 MDI and an Mn of 40,000 to 60,000 and a Mw of 125,000 to 175,000 and an Mw to Mn ratio of 2.5 to 4 The second thermoplastic polyurethane has by molecular percent, 40 to 50 adipic acid, 20 to 40 adipic acid butane diol, 5 to 20 MDI-ethylene glycol and 5 to 25 MDI and an Mn of 60,000 to 80,000 and a Mw of 125,000 to 175,000 and an Mw to Mn ratio of 1.5 to 3.