| abstract |
THE OBJECT OF THE PRESENT INVENTION IS TO PROVIDE A POLISHING PAD EXCELLENT IN DURABILITY. THE PRESENT INVENTION RELATES TO A METHOD FOR MANUFACTURING A POLISHING PAD, COMPRISING STEPS OF PREPARING A CELL-DISPERSED URETHANE COMPOSITION BY MECHANICAL FOAMING METHOD, COATING A SHEET A HAVING A NITROGEN GAS PERMEABILITY RATE OF 1X10-7 [CM3/CM2.S.CMHG) OR LESS WITH THE CELL-DISPERSED URETHANE COMPOSITION, LAMINATING A SHEET B HAVING A NITROGEN GAS PERMEABILITY RATE OF 1X10-7 [CM3/CM2.S.CMHG] OR LESS ON THE COATED CELL-DISPERSED URETHANE COMPOSITION, AND CURING THE CELL-DISPERSED URETHANE COMPOSITION WHILE KEEPING THE THICKNESS THEREOF UNIFORM WITH A PRESSING MEANS TO FORM A POLISHING LAYER COMPRISING A THERMOSETTING POLYURETHANE FOAM LAYER WITH A CELL STRUCTURE HAVING AN INTERCONNECTED CELL RATE IS 50% OR MORE, AN AVERAGE CELL DIAMETER IS 20 TO 300 µM AND AN AVERAGE DIAMETER OF CIRCULAR PORES IN THE SURFACES OF THE INTERCONNECTED CELLS IS 100 µM OR LESS, WHEREIN THE SHEET A AND B ARE EACH INDEPENDENTLY POLYETHYLENE TEREPHTHALATE SHEET, POLYPROPYLENE SHEET, POLYETHYLENE SHEET HAVING A THICKNESS OF 0.025 TO 0.3 MM, OR A DOUBLE-SIDED TAPE HAVING ADHESIVE LAYERS ON BOTH SIDES OF THE ABOVE SHEET. |