METHOD FOR PRODUCING CLOSED CELL CELLULAR MATERIAL FOR USE IN POLISHING, CELLULAR SHEET FOR POLISHING, LAMINATE FOR POLISHING AND POLISHING METHOD, METHOD FOR PRODUCING LAMINATE FOR POLISHING, AND GROOVED POLISHING PAD

摘要

A method for producing a closed cell cellular material having an average cell diameter of 0.1 to 100 mum, which comprises a step (A) of incorporating a blowing agent into a molten resin under a pressure of more than 10 MPa of an atmosphere in an extruder, and a subsequent step (B) of exposing the resultant molten resin to a pressure lower than the pressure at the time of incorporation of the blowing agent; a cellular sheet and a laminate for polishing using a closed cell cellular material produced by the method; a polishing method using the laminate for polishing; a method for producing the laminate for polishing; and a grooved polishing pad.