Adhesive sheet

Abstract

Provided is an adhesive sheet, which has a high adhesion and removability, corrodes a metal to a low degree, generates small amount of outgases, and is particularly suitable as an adhesive sheet for being adhered to an electronic part. The adhesive sheet includes an adhesive layer provided for at least one surface of a substrate sheet, in which a pressure-sensitive adhesive of which the adhesive layer is formed includes a resin composition mainly formed of an acrylic copolymer obtained by blending a carboxyl group-free acrylic copolymer obtained by copolymerizing the following components (A) to (C) with (D) an isocyanate-based cross-linking agent: (A) 76.999 to 94.999% by mass of an alkyl(meth)acrylate; (B) 5.0 to 23.0% by mass of an ethylenically unsaturated group-containing morpholine-based compound; and (C) 0.001 to 1.5% by mass of a functional group-containing unsaturated monomer; and a ratio M2/M1 of the mole number (M2) of isocyanate groups in the component (D) to the mole number (M1) of functional groups in the component (C) is 1.5 to 15.0.

1 . An adhesive sheet, comprising an adhesive layer provided for at least one surface of a substrate sheet,
 wherein a pressure-sensitive adhesive of which the adhesive layer is formed comprises a resin composition mainly formed of an acrylic copolymer obtained by blending a carboxyl group-free acrylic copolymer obtained by copolymerizing the following components (A) to (C) with (D) an isocyanate-based cross-linking agent:
 (A) 76.999 to 94.999% by mass of an alkyl(meth)acrylate; 
 (B) 5.0 to 23.0% by mass of an ethylenically unsaturated group-containing morpholine-based compound; and 
 (C) 0.001 to 1.5% by mass of a functional group-containing unsaturated monomer; and 
   a ratio M2/M1 of a mole number (M2) of isocyanate groups in the component (D) to a mole number (M1) of functional groups in the component (C) is 1.5 to 15.0.   
     
     
         2 . The adhesive sheet according to  claim 1 , wherein the ratio M2/M1 is 2.0 to 10.0. 
     
     
         3 . The adhesive sheet according to  claim 1 , wherein the component (C), comprises an unsaturated monomer having a hydroxyl group. 
     
     
         4 . The adhesive sheet according to  claim 1 , wherein the isocyanate-based cross-linking agent (D) comprises xylylene diisocyanates. 
     
     
         5 . The adhesive sheet according to  claim 1 , wherein the alkyl(meth)acrylate comprises n-butyl acrylate. 
     
     
         6 . The adhesive sheet according to  claim 1 , wherein a release layer surface of a release sheet formed of a release substrate and a non-silicone-based release layer is laminated on an adhesive layer surface of the adhesive sheet. 
     
     
         7 . The adhesive sheet according to  claim 1 , wherein the adhesive sheet generates outgases in an amount of less than 0.5 μg/cm 2  in terms of n-decane. 
     
     
         8 . The adhesive sheet according to  claim 1 , wherein the adhesive sheet is a sheet to be adhered to an electronic part. 
     
     
         9 . The adhesive sheet according to  claim 8 , wherein the electronic part comprises a hard disk drive.