Process for manufacturing polishing pad
View Patent ↗A method for manufacturing a polishing pad that has a high level of optical detection accuracy and is prevented from causing slurry leak from between the polishing region and the light-transmitting region includes preparing a cell-dispersed urethane composition by a mechanical foaming method; placing a light-transmitting region at a predetermined position on a face material or a belt conveyor, continuously discharging the cell-dispersed urethane composition onto a part of the face material or the belt conveyor where the light-transmitting region is not placed; placing another face material or belt conveyor on the discharged cell-dispersed urethane composition; curing the cell-dispersed urethane composition to form a polishing region including a polyurethane foam, so that a polishing sheet is prepared; applying a coating composition containing an aliphatic and/or alicyclic polyisocyanate to one side of the polishing sheet and curing the coating composition to form a water-impermeable film; and cutting the polishing sheet.
1. A method for manufacturing a polishing pad, comprising the steps of:
preparing a cell-dispersed urethane composition by a mechanical foaming method;
placing a light-transmitting region at a predetermined position on a face material or a belt conveyor, while feeding or moving the face material or the belt conveyor;
continuously discharging the cell-dispersed urethane composition onto a part of the face material or the belt conveyor where the light-transmitting region is not placed;
placing another face material or another belt conveyor on the discharged cell-dispersed urethane composition;
curing the cell-dispersed urethane composition to form a polishing region comprising a polyurethane foam, while its thickness is controlled to be uniform, so that a polishing sheet is prepared;
applying, after removing the face material or the belt conveyor from the polishing sheet, a polyurethane resin coating composition containing an aliphatic and/or alicyclic polyisocyanate to a side of the polishing sheet from which the face material or the belt conveyor is removed and curing the polyurethane resin coating composition to form a water-impermeable film; and
cutting the polishing sheet.
2. The method of claim 1 , wherein the water-impermeable film has a thickness of 20 μm to 100 μm.