Pressure sensitive adhesive for sticking an electromagnetic wave-shielding film and an optically functional film, and a display panel filter element containing same

Abstract

A pressure sensitive adhesive for sticking together an electromagnetic wave-shielding film and an optically functional film, wherein a storage elastic modulus at 70° C. is 7.00×10 4 Pa or more; and a display panel filter element comprising (1) an electromagnetic wave-shielding film, the film being a laminate of a transparent substrate film, an adhesive for a metal foil, which is applied on one surface of the transparent substrate film, and a metal foil mesh formed on the adhesive for a metal foil, (2) a layer of the pressure sensitive adhesive according to (1), which is applied so as to cover the metal foil mesh of the electromagnetic wave-shielding film, and (3) an optically functional film provided on the pressure sensitive adhesive, are provided. The pressure sensitive adhesive exhibits a sufficient adhesive strength, can be filled into the inside of the pores of the metal foil mesh, and does not generate bubbles in a heating treatment.

1 . A pressure sensitive adhesive for sticking together an electromagnetic wave-shielding film and an optically functional film, wherein a storage elastic modulus at 70° C. is 7.00×10 4  Pa or more. 
   
   
       2 . The pressure sensitive adhesive according to  claim 1 , wherein a storage elastic modulus at 23° C. is 1.00×10 5  Pa or more. 
   
   
       3 . The pressure sensitive adhesive according to  claim 1 , wherein a peak temperature of loss tangent (tan δ) is −15° C. or more. 
   
   
       4 . The pressure sensitive adhesive according to  claim 1 , comprising an acrylic copolymer containing (meth)acrylic alkyl ester monomers as a comonomer. 
   
   
       5 . The pressure sensitive adhesive according to  claim 4 , comprising the acrylic copolymer further containing nitrogen-containing vinyl monomers as a comonomer. 
   
   
       6 . The pressure sensitive adhesive according to  claim 4 , wherein said acrylic copolymer does not contain an acid comonomer. 
   
   
       7 . The pressure sensitive adhesive according to  claim 5 , wherein said acrylic copolymer does not contain an acid comonomer. 
   
   
       8 . A display panel filter element comprising 
     (1) an electromagnetic wave-shielding film, said film being a laminate of a transparent substrate film, an adhesive for a metal foil, which is applied on one surface of said transparent substrate film, and a metal foil mesh formed on said adhesive for a metal foil, 
     (2) a layer of said pressure sensitive adhesive according to  claim 1 , which is applied so as to cover said metal foil mesh of said electromagnetic wave-shielding film, and 
     (3) an optically functional film provided on said pressure sensitive adhesive. 
   
   
       9 . The display panel filter element according to  claim 8 , wherein a storage elastic modulus at 23° C. of said pressure sensitive adhesive is 1.00×10 5  Pa or more. 
   
   
       10 . The display panel filter element according to  claim 8 , wherein a peak temperature of loss tangent (tan δ) of said pressure sensitive adhesive is −15° C. or more. 
   
   
       11 . The display panel filter element according to  claim 8 , wherein said pressure sensitive adhesive comprises an acrylic copolymer containing (meth)acrylic alkyl ester monomers as a comonomer. 
   
   
       12 . The display panel filter element according to  claim 11 , wherein said pressure sensitive adhesive comprises the acrylic copolymer further containing nitrogen-containing vinyl monomers as a comonomer. 
   
   
       13 . The display panel filter element according to  claim 11 , wherein said acrylic copolymer does not contain an acid comonomer. 
   
   
       14 . The display panel filter element according to  claim 12 , wherein said acrylic copolymer does not contain an acid comonomer.