Abstract: Provided herein is a process for producing a layered sheet. The process involves preparing a cell dispersed urethane composition by a mechanical foaming method. The cell dispersed urethane composition is applied to a base material sheet and cured to produce a polyurethane foam layer of uniform thickness. A releasing sheet may be utilized to make the thickness of the polyurethane foamed layer uniform. Also, provided herein is a layered sheet produced by the above process. The polyurethane foamed layer may have spherical fine cells having an average cell diameter of 20 to 300 ?m. The polyurethane foamed layer may have a specific gravity of 0.2 to 0.5. The polyurethane foamed layer may also have a Asker C hardness of 10 to 50 degrees.

Abstract: A polishing pad provides excellent optical detection accuracy properties over a broad wavelength range (particularly at the short-wavelength side) and is capable of preventing a slurry from leaking from the boundary between a polishing region and a light-transmitting region. The polishing pad includes at least a transparent support film laminated on one side of a polishing layer including a polishing region and a light-transmitting region; the light transmittance of an optical detection region containing at least the light-transmitting region and the transparent support film is 40% or more in the overall range of wavelengths of 300 to 400 nm.

Abstract: A method for manufacturing a polishing pad that has 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 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 water-impermeable film; and cutting the polishing

Abstract: A method for manufacturing a polishing pad prevents slurry leaks and provides a pad that can be used to provide high optical detection accuracy. The method for manufacturing a polishing pad includes forming a groove for injecting a light-transmitting region forming material on the back surface of a polishing layer; injecting the light-transmitting region forming material into the groove and curing the material to form a light-transmitting region; and buffing the front surface of the polishing layer to expose the light-transmitting region on the front surface.

Abstract: 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 poli

Abstract: A method for manufacturing a polishing pad containing substantially spherical cells and having high thickness accuracy includes preparing a cell-dispersed urethane composition by a mechanical foaming method; continuously discharging the cell-dispersed urethane composition from a single discharge port to a substantially central portion in the width direction of a face material A, while feeding the face material A; laminating a face material B on the cell-dispersed urethane composition; then uniformly adjusting the thickness of the cell-dispersed urethane composition by thickness adjusting means; curing the cell-dispersed urethane composition with the thickness adjusted in the preceding step without applying any additional load to the composition so that a polishing sheet including a polyurethane foam is formed; and cutting the polishing sheet.

Abstract: A polishing pad of excellent durability has a polishing layer is arranged on a base material layer, and the polishing layer comprises a thermosetting polyurethane foam having roughly spherical interconnected cells with an average cell diameter of 35 to 300 ?m.

Abstract: An object of the invention is to provide a polishing pad excellent in durability and in the adhesiveness between a polishing layer and a base material layer. The first invention relates to a polishing pad comprising a polishing layer arranged on a base material layer, wherein the polishing layer comprises a thermosetting polyurethane foam having roughly spherical interconnected cells having an average cell diameter of 20 to 300 ?m, the polyurethane foam comprises an isocyanate component and an active hydrogen-containing compound as starting components, and the active hydrogen-containing compound comprises 30 to 85% by weight of a high-molecular-weight polyol having 2 to 4 functional groups and a hydroxyl value of 20 to 100 mg KOH/g.

Abstract: A method for inexpensively and easily manufacturing a polishing pad of excellent durability and polishing speed stability includes preparing a cell dispersed urethane composition by mechanical foaming, applying the cell dispersed urethane composition onto a base material layer, forming a polyurethane foamed layer having roughly spherical interconnected cells by curing the cell dispersed urethane composition, and regulating the thickness of the polyurethane foamed layer uniformly.

Abstract: Provided herein is a process for producing a layered sheet. The process involves preparing a cell dispersed urethane composition by a mechanical foaming method. The cell dispersed urethane composition is applied to a base material sheet and cured to produce a polyurethane foam layer of uniform thickness. A releasing sheet may be utilized to make the thickness of the polyurethane foamed layer uniform. Also, provided herein is a layered sheet produced by the above process. The polyurethane foamed layer may have spherical fine cells having an average cell diameter of 20 to 300 ?m. The polyurethane foamed layer may have a specific gravity of 0.2 to 0.5. The polyurethane foamed layer may also have a Asker C hardness of 10 to 50 degrees.

Abstract: A polishing pad provides excellent optical detection accuracy properties over a broad wavelength range (particularly at the short-wavelength side). A method for manufacturing a semiconductor device includes a process of polishing the surface of a semiconductor wafer with this polishing pad. The polishing pad has a polishing layer containing a polishing region and a light-transmitting region, wherein the light-transmitting region includes a polyurethane resin having an aromatic ring density of 2 wt % or less, and the light transmittance of the light-transmitting region is 30% or more in the overall range of wavelengths of 300 to 400 nm.

Abstract: An object of the present invention is to provide a polishing pad excellent in optical detection accuracy in a broad wavelength range (particularly at the short-wavelength side) and capable of preventing a slurry from leaking from the boundary between a polishing region and a light-transmitting region. Disclosed is a polishing pad including at least a transparent support film laminated on one side of a polishing layer including a polishing region and a light-transmitting region, wherein the light transmittance of an optical detection region containing at least the light-transmitting region and the transparent support film is 40% or more in the overall range of wavelengths of 300 to 400 nm.

Abstract: 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.

Abstract: To provide a polishing pad which is insusceptible to clogging of groove with abrasive particles and grinding dusts during polishing, and leads to little decrease in polishing rate even after long-term continuous use. A polishing pad of the present invention has a polishing layer formed of polyurethane resin foam having fine-cells, and asperity structure formed in a polishing surface of the polishing layer, and is featured in that the polyurethane resin foam is a reaction cured product between isocyanate-terminated prepolymer containing high-molecular-weight polyol component and isocyanate component, and a chain extender, and contains a silicon-based surfactant having combustion residue of not less than 8 wt %.

Abstract: Disclosed is a method for production of a laminate polishing pad which comprises a reduced number of steps and is excellent in productivity rate, and which causes no detachment between a polishing layer and a cushion layer and can prevent the groove clogging caused by a slurry or the like. Also disclosed is a laminate polishing pad produced by the method. A method for production of a laminate polishing pad, comprising the steps of: preparing a cell-dispersed urethane composition by a mechanical frothing process; ejecting the cell-dispersed urethane composition onto a cushion layer continuously while feeding the cushion layer; curing the cell-dispersed urethane composition while controlling the thickness of the composition evenly to form a polishing layer made of a polyurethane foam, thereby producing a long laminate sheet; and cutting the long laminate sheet.