Adhesive, adhesive layer, and adhesive sheet

Abstract

A pressure-sensitive adhesive of the invention include a (meth)acryl-based polymer obtained by polymerization of a monomer component including 30 to 99.5% by weight of an alkyl (meth)acrylate having an alkyl group of 10 to 18 carbon atoms at an ester end and 0.5 to 50% by weight of a cyclic nitrogen-containing monomer. The pressure-sensitive adhesive has a satisfactory level of adhesive performance and can form a pressure-sensitive adhesive layer with a lower dielectric constant and reliable moisture resistance.

1 .- 19 . (canceled) 
     
     
         20 . A pressure-sensitive adhesive sheet, comprising a transparent conductive film as a support and a pressure-sensitive adhesive layer formed on at least one side of the transparent conductive film,
 wherein the pressure-sensitive adhesive layer is obtained from a pressure-sensitive adhesive composition,   wherein the pressure-sensitive adhesive composition comprises a (meth)acryl-based polymer obtained by polymerization of a monomer component including 30 to 99.5% by weight of an alkyl (meth)acrylate having an alkyl group of 10 to 18 carbon atoms at an ester end and 0.5 to 50% by weight of a cyclic nitrogen-containing monomer.   
     
     
         21 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the alkyl group of the alkyl (meth)acrylate having the alkyl group of 10 to 18 carbon atoms at the ester end is a branched alkyl group. 
     
     
         22 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the alkyl (meth)acrylate having the alkyl group of 10 to 18 carbon atoms at the ester is an alkyl methacrylate having an alkyl group of 10 to 18 carbon atoms at the ester end. 
     
     
         23 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the alkyl (meth)acrylate having the alkyl group of 10 to 18 carbon atoms at the ester is an alkyl acrylate having an alkyl group of 10 to 18 carbon atoms at the ester end. 
     
     
         24 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the monomer component further includes 0.5% by weight or more of at least one functional group-containing monomer selected from a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and a cyclic ether group-containing monomer. 
     
     
         25 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the monomer component further includes 0.5% or more by weight of at least one selected from an alkyl (meth)acrylate having an alkyl group of 1 to 9 carbon atoms at an ester end and an alkyl (meth)acrylate having a cyclic alkyl group at an ester end. 
     
     
         26 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the monomer component further includes 3% or less by weight of a polyfunctional monomer. 
     
     
         27 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the pressure-sensitive adhesive composition comprises 0.01 to 5 parts by weight of a crosslinking agent based on 100 parts by weight of the (meth)acryl-based polymer. 
     
     
         28 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the pressure-sensitive adhesive layer has a relative dielectric constant of 3.5 or less at a frequency of 100 kHz. 
     
     
         29 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the pressure-sensitive adhesive layer has a gel fraction of 20 to 98% by weight. 
     
     
         30 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the pressure-sensitive adhesive layer has a haze of 2% or less when having a thickness of 25 μm. 
     
     
         31 . The pressure-sensitive adhesive sheet according to  claim 20 , wherein the pressure-sensitive adhesive layer has a total light transmittance of 90% or more. 
     
     
         32 . The pressure-sensitive adhesive sheet according to  claim 20 , which has an adhesive strength of 0.5 N/20 mm or more to alkali glass at a peel angle of 90° and a peel rate of 300 mm/minute.