Method for manufacturing polishing pad
View Patent ↗A method for manufacturing a polishing pad, which may be laminated, with a small number of manufacturing steps, high productivity and no peeling between a polishing layer and a cushion layer includes preparing a cell-dispersed urethane composition by a mechanical foaming method; continuously discharging the cell-dispersed urethane composition onto a face material, while feeding the face material; laminating another face material on the cell-dispersed urethane composition; curing the cell-dispersed urethane composition, while controlling its thickness to be uniform, so that a polishing layer including a polyurethane foam is formed; cutting the polishing layer parallel to the face into two pieces so that two long polishing layers each including the polishing layer and the face material are simultaneously formed; and cutting the long polishing layers to produce the polishing pad.
1. A method for manufacturing a polishing pad, comprising the steps of:
preparing a cell-dispersed urethane composition by a mechanical foaming method;
feeding a face material in a feeding direction;
while feeding the face material, feeding in the feeding direction a first spacer on the face material so as to be at one end of a width direction of the face material, feeding in the feeding direction a second spacer on the face material so as to be at other end of the width direction of the face material, and feeding in the feeding direction a third spacer on the face material so as to be between the first and second spacers;
continuously discharging said cell-dispersed urethane composition onto a part of said face material where the spacers are not provided;
laminating another face material on said discharged cell-dispersed urethane composition;
curing the cell-dispersed urethane composition, while controlling its thickness to be uniform, so that a long polishing layer comprising a polyurethane foam is formed; and
cutting the long polishing layer.
2. The method according to claim 1 , wherein at least one of the spacers comprises a thermoplastic resin or a thermosetting resin.
3. The method according to claim 1 , wherein the third spacer has a light transmittance of at least 20% throughout the wavelength range of 400 nm to 700 nm.
4. The method according to claim 1 , wherein at least one of the spacers comprises a polyurethane foam whose composition is the same as that of said cell-dispersed urethane composition.
5. The method according to claim 1 , wherein the third spacer is a laminate comprising at least two peelable resin sheets.