Electrically peelable adhesive composition, adhesive sheet, and joined body

Abstract

There is provided an electrically peelable adhesive composition that is for forming an adhesive layer which has high adhesion and can be easily peeled off by applying a voltage for a short time even at a low voltage. In addition, there is provided an adhesive sheet including an adhesive layer formed of the composition that has high adhesion and can be easily peeled off by applying a voltage for a short time even at a low voltage, and a joined body of the adhesive sheet and an adherend. The electrically peelable adhesive composition of the invention includes a polymer and an ionic liquid, in which an anion of the ionic liquid is a bis(fluorosulfonyl)imide anion. A content of the ionic liquid is preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the polymer.

1 . An electrically peelable adhesive composition comprising:
 a polymer, and   an ionic liquid,   wherein an adhesion force recovery rate of the adhesive sheet after 10 seconds from stopping an application of voltage is 20% or less.   
     
     
         2 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein a content of the ionic liquid is 0.5 to 30 parts by weight with respect to 100 parts by weight of the polymer.   
     
     
         3 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein a glass transition temperature of the polymer is 0° C. or lower.   
     
     
         4 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein the polymer is an acrylic polymer.   
     
     
         5 . The electrically peelable adhesive composition according to  claim 4 ,
 wherein the acrylic polymer has a monomer unit derived from an alkyl (meth)acrylate having an alkyl group having 1 to 14 carbon atoms.   
     
     
         6 . The electrically peelable adhesive composition according to  claim 4 ,
 wherein the acrylic polymer has a monomer unit derived from alkyl (meth)acrylate having an alkyl group having 1 to 14 carbon atoms and a monomer unit derived from a polar group-containing monomer.   
     
     
         7 . The electrically peelable adhesive composition according to  claim 6 ,
 wherein the polar group-containing monomer is a carboxyl group-containing monomer.   
     
     
         8 . The electrically peelable adhesive composition according to  claim 5 ,
 wherein the alkyl (meth)acrylate having an alkyl group having 1 to 14 carbon atoms is butyl (meth)acrylate.   
     
     
         9 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein at least one selected from the group consisting of a nitrogen-containing onium cation, a sulfur-containing onium cation, and a phosphorus-containing onium cation is contained as a cation of the ionic liquid.   
     
     
         10 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein at least one cation selected from Formulas (2-A) to (2-D) below is contained as a cation of the ionic liquid.   
       
         
           
           
               
               
           
         
         (In Formula (2-A), R 1  represents a hydrocarbon group having 4 to 10 carbon atoms and may contain a hetero atom, and R 2  and R 3  are the same as or different from each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and may also contain a hetero atom. Where, in a case where a nitrogen atom forms a double bond with an adjacent carbon atom, there is no R 3 . In Formula (2-B), R 4  represents a hydrocarbon group having 2 to 10 carbon atoms and may contain a hetero atom, and R 5 , R 6 , and R 7  are the same as or different from each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and may also contain a hetero atom. In Formula (2-C), R 8  represents a hydrocarbon group having 2 to 10 carbon atoms and may contain a hetero atom, and R 9 , R 10 , and R 11  are the same as or different from each other, represent a hydrogen atom or a hydrocarbon group having 1 to 16 carbon atoms, and may also contain a hetero atom. In Formula (2-D), X represents a nitrogen atom, a sulfur atom, or a phosphorus atom, and R 12 , R 13 , R 14 , and R 15  are the same as or different from each other, represent a hydrocarbon group having 1 to 16 carbon atoms, and may also contain a hetero atom. Where, in a case where X is a sulfur atom, there is no R 12 .) 
       
     
     
         11 . The electrically peelable adhesive composition according to  claim 1 ,
 wherein a molecular weight of the cation of the ionic liquid is 250 or less.   
     
     
         12 . An adhesive sheet comprising:
 an adhesive layer that is formed of the electrically peelable adhesive composition according to  claim 1 .   
     
     
         13 . The adhesive sheet according to  claim 12 ,
 wherein the adhesive layer has a thickness of 1 μm or more and 1000 μm or less.   
     
     
         14 . The adhesive sheet according to  claim 12 ,
 wherein the adhesive sheet is a double-sided adhesive sheet not including a substrate layer.   
     
     
         15 . A joined body having at least a laminate structure comprising a conductive adherend and the adhesive sheet according to  claim 12 . 
     
     
         16 . A joined body having a laminate structure comprising one conductive adherend, the adhesive sheet according to  claim 12 , and the other conductive adherend.