CPC B24B 37/24 (2013.01) [C08G 18/12 (2013.01); C08G 18/1825 (2013.01); C08G 18/3206 (2013.01); C08G 18/4854 (2013.01); C08G 18/7671 (2013.01); C08J 9/30 (2013.01); C08J 2201/022 (2013.01); C08J 2375/08 (2013.01)] | 7 Claims |
1. A chemical mechanical (CMP) polishing pad for polishing a substrate chosen from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate, the polishing pad comprising a polishing layer adapted for polishing the substrate, the polishing layer comprising a thermoset polyurethane foam having roughly spherical hollow cells that are isolated or partially connected forming small isolated clusters, the polyurethane form is a product of an organic solvent free two-component reaction mixture comprising (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or a linear aromatic isocyanate-terminated urethane prepolymer having an unreacted isocyanate (NCO) concentration of 18 to 47 wt. %, based on the total solids weight of the aromatic isocyanate component, (ii) a liquid polyol component, and (iii) one or more curatives selected from the group of amines having Formulas (I) and (II)
![]() wherein each R1 and R2 are independently C1-C6 alkyl, C1-C4 alkyl substituted with one or more C1-C4 alkyl or one or more halogens, —(CR5R6)p—S—(CR5R6)q— or —(CR5R6)p—O—(CR5R6)q—; R3 is C1-C6 alkyl or C1-C4 alkyl substituted with one or more C1-C4 alkyl; each R4 is independently H or —R1—OH; each R5 and R6 are independently H or C1-C6 alkyl; each p and q are independently an integer from 1 through 5; and n is in the range of 1 to 4, wherein the reaction mixture comprises 55 to 75 wt. % of hard segment materials, based on the total weight of the reaction mixture, the total amount of the curatives (I) and/or (II) range from 9 to 26.8 wt %, based on the total weight of the reaction mixture, the CMP polishing layer has a unfilled Shore D (2 second) hardness of 57-77 or a filled Shore D (2 second) hardness of 18-50, and densities of 0.43 to 0.78 g/mL.
|