HOT-MELT ADHESIVE SHEET FOR STACKED POLISHING PAD AND ADHESIVE-LAYER-BEARING SUPPORT LAYER FOR STACKED POLISHING PAD
The purpose of the present invention is to provide a hot-melt adhesive sheet for a stacked polishing pad wherein a polishing layer is resistant to detachment from a support layer even when high temperatures are produced by long periods of polishing. This hot-melt adhesive sheet is used to laminate a polishing layer to a support layer, and the hot-melt adhesive is a polyester-based hot-melt adhesive that, for each 100 weight parts of a polyester-resin base polymer, contains 2 to 10 weight parts of an epoxy resin that has at least two glycidyl groups per molecule.
1 . A hot-melt adhesive sheet for use in laminating a polishing layer and a support layer to form a stacked polishing pad, the hot-melt adhesive sheet comprising a hot-melt adhesive, wherein the hot-melt adhesive is a polyester-based hot-melt adhesive containing 100 parts by weight of a polyester resin as a base polymer and 2 to 10 pans by weight of an epoxy resin having two or more glycidyl groups per molecule.
2 . The hot-melt adhesive sheet according to claim 1 , wherein the polyester resin is a crystalline polyester resin.
3 . The hot-melt adhesive sheet according to claim 1 , wherein the polyester-based hot-melt adhesive has a melting point of 100 to 200° C. and a specific gravity of 1.1 to 13 and also has a melt flow index of 16 to 26 g/10 minutes under conditions of a temperature of 150° C. and a load of 2.16 kg.
4 . The hot-melt adhesive sheet according to claim 1 , which is a double-sided tape comprising: a backing whose both sides have been subjected to an adhesion-facilitating treatment; and adhesive layers provided on both sides of the backing, wherein the adhesive layers each comprise the hot-melt adhesive.
5 . The hot-melt adhesive sheet according to claim 4 , wherein the adhesion-facilitating treatment is a corona treatment or a plasma treatment.
6 . An adhesive-layer-bearing support layer for a stacked polishing pad, comprising: a support layer; and an adhesive layer formed on one side of the support layer by applying a polyester-based hot-melt adhesive to one side of the support layer and curing the polyester-based hot-melt adhesive, wherein the polyester-based hot-melt adhesive contains 100 parts by weight of a polyester resin as a base polymer and 2 to 10 parts by weight of an epoxy resin having two or more glycidyl groups per molecule.
7 . The adhesive-layer-bearing support layer according to claim 6 , wherein the polyester resin is a crystalline polyester resin.
8 . The adhesive-layer-bearing support layer according to claim 6 , wherein the polyester-based hot-melt adhesive has a melting point of 100 to 200° C. and a specific gravity of 1.1 to 1.3 and also has a melt flow index of 16 to 26 g/10 minutes under conditions of a temperature of 150° C. and a load of 2.16 kg.
9 . The adhesive-layer-bearing support layer according to claim 6 , wherein the support layer is a polyurethane foam sheet having a skin layer on a side where the adhesive layer is formed.
10 . The adhesive-layer-bearing support layer according to claim 9 , wherein the polyurethane foam sheet is made from thermosetting polyurethane.