Polishing sheet and polishing method

Abstract

Object: To provide a polishing sheet capable of efficiently polishing a hard material such as a metal product so as to form a smooth surface with minimal unevenness. Solution: A polishing sheet (10) including: a substrate (11); a plurality of three-dimensional elements (12) containing abrasive grains and a binding material; and an intermediate layer (13) provided between the three-dimensional elements (12) and the substrate (11) so as to join the substrate (11) and the three-dimensional elements (12), wherein a Youngs modulus of the substrate (11) at 25° C. is not less than 3.0×109Pa; and a Youngs modulus of the intermediate layer (13) at 25° C. is not less than 1.0×107Pa and not greater than 5.0×108Pa.

1 . A polishing sheet comprising:
 a substrate;   a plurality of three-dimensional elements containing abrasive grains and a binding material; and   an intermediate layer provided between the three-dimensional elements and the substrate so as to join the substrate and the three-dimensional elements,   wherein a Young's modulus of the substrate at 25° C. is not less than 3.0×10 9  Pa; and   a Young's modulus of the intermediate layer at 25° C. is not less than 1.0×10′ Pa and not greater than 5.0×10 8  Pa.   
     
     
         2 . The polishing sheet according to  claim 1 , wherein a Young's modulus of the binding material at 25° C. is not less than 1.0×10 9  Pa. 
     
     
         3 . The polishing sheet according to  claim 1 , wherein the binding material contains: a resin composition containing an acrylic monomer; and
 not less than 60 mass % of the acrylic monomer is a polyfunctional monomer selected from the group consisting of tris(2-hydroxyethyl)isocyanurate triacrylate and tris(2-hydroxyethyl)isocyanurate diacrylate.   
     
     
         4 . The polishing sheet according to  claim 1 , wherein a breaking elongation of the substrate is not greater than 200%. 
     
     
         5 . The polishing sheet according to  claim 1 , wherein the substrate contains at least one selected from the group consisting of resin films and metal films. 
     
     
         6 . The polishing sheet according to  claim 1 , wherein the intermediate layer contains a cured product of a resin composition containing a urethane acrylate. 
     
     
         7 . The polishing sheet according to  claim 1 , wherein the binding material contains a phenol resin. 
     
     
         8 . A polishing sheet comprising:
 a substrate;   a plurality of three-dimensional elements containing abrasive grains and a binding material; and   an intermediate layer provided between the three-dimensional elements and the substrate so as to join the substrate and the three-dimensional elements,   wherein the binding material contains a cured product of a resin composition containing an acrylic monomer; and   not less than 60 mass % of the acrylic monomer is a polyfunctional monomer selected from the group consisting of tris(2-hydroxyethyl)isocyanurate triacrylate and tris(2-hydroxyethyl)isocyanurate diacrylate.   
     
     
         9 . A polishing method using the polishing sheet according to  claim 1 , the method comprising sliding the polishing sheet and an object to be polished while pressing the polishing sheet against the object to be polished under a load of not less than 1.0×10 6  Pa. 
     
     
         10 . A polishing method using the polishing sheet according to  claim 8 , the method comprising sliding the polishing sheet and an object to be polished while pressing the polishing sheet against the object to be polished under a load of not less than 1.0×10 6  Pa.