Magnetic sheet composition, magnetic sheet, and method for producing magnetic sheet

Abstract

To provide a magnetic sheet composition, which contains: a binder; magnetic powder; and a curing agent, wherein the binder contains a thermosetting organic resin, and the curing agent contains a sulfonium borate complex expressed by General Formula 1: where R 1 is an aralkyl group, R 2 is a lower alkyl group, X is a halogen atom, and n is an integer of 0 to 3.

1 . A magnetic sheet composition, comprising:
 a binder;   magnetic powder; and   a curing agent,   wherein the binder contains a thermosetting organic resin, and the curing agent contains a sulfonium borate complex expressed by General Formula 1:   
       
         
           
           
               
               
           
         
         where R 1  is an aralkyl group, R 2  is a lower alkyl group, X is a halogen atom, and n is an integer of 0 to 3. 
       
     
     
         2 . The magnetic sheet composition according to  claim 1 , wherein R 1  is a benzyl group, an o-methyl benzyl group, or a (1-naphthyl)methyl group. 
     
     
         3 . The magnetic sheet composition according to  claim 1 , wherein R 2  is a methyl group. 
     
     
         4 . The magnetic sheet composition according to  claim 1 , wherein the sulfonium borate complex is contained in an amount of 2 parts by mass to 15 parts by mass relative to 106.1 parts by mass of the binder. 
     
     
         5 . The magnetic sheet composition according to  claim 1 , further comprising a flame retardant, wherein the flame retardant contains carboxylic acid amide-containing melamine cyanurate. 
     
     
         6 . A method for producing a magnetic sheet, comprising:
 applying a magnetic sheet composition onto a substrate;   drying the magnetic sheet composition applied onto the substrate; and   thermosetting the dried magnetic sheet composition,   wherein the magnetic sheet composition comprises:   a binder;   magnetic powder; and   a curing agent,   wherein the binder contains a thermosetting organic resin, and the curing agent contains a sulfonium borate complex expressed by General Formula 1:   
       
         
           
           
               
               
           
         
         where R 1  is an aralkyl group, R 2  is a lower alkyl group, X is a halogen atom, and n is an integer of 0 to 3. 
       
     
     
         7 . The method for producing a magnetic sheet according to  claim 6 , further comprising:
 stacking a convex-concave forming layer and a pattern transferring layer on a surface of a magnetic layer, which is formed by thermosetting the magnetic sheet composition, in this order from the side of the magnetic layer so as to form a stacked body; and   hot-pressing the stacked body so as to transfer a surface configuration of the pattern transferring layer to surfaces of the convex-concave forming layer and the magnetic layer, as well as bonding the convex-concave forming layer and the magnetic layer together.   
     
     
         8 . A magnetic sheet, obtained by the method comprising:
 applying a magnetic sheet composition onto a substrate;   drying the magnetic sheet composition applied onto the substrate; and   thermosetting the dried magnetic sheet composition,   wherein the magnetic sheet composition comprises:   a binder;   magnetic powder; and   a curing agent,   wherein the binder contains a thermosetting organic resin, and the curing agent contains a sulfonium borate complex expressed by General Formula 1:   
       
         
           
           
               
               
           
         
         where R 1  is an aralkyl group, R 2  is a lower alkyl group, X is a halogen atom, and n is an integer of 0 to 3.