Adhesive layer-equipped transparent surface material, display device and processes for their production

Abstract

Provided is an adhesive layer-equipped transparent surface material that can easily be bonded to another surface material (a display panel, etc.) and that, when bonded to another surface material, is less likely to have voids left at the interface between the adhesive layer and another surface material. An adhesive layer-equipped transparent surface material 1 comprises an adhesive layer 14 formed on at least one surface of a protective plate 10 (a transparent surface material), wherein the adhesive layer 14 has a layer portion 18 spreading over the surface of the protective plate 10 and a barrier portion 20 surrounding the periphery of the layer portion 18 ; and the layer portion 18 has a shear modulus at 35° C. of from 0.5 to 100 kPa.

What is claimed is: 
     
         1 . An adhesive layer-equipped transparent surface material comprising a transparent surface material and an adhesive layer formed on at least one surface of the transparent surface material, wherein the adhesive layer has a layer portion spreading over the surface of the transparent surface material and a barrier portion surrounding the periphery of the layer portion; and the layer portion has a shear modulus at 35° C. of from 0.5 to 100 kPa. 
     
     
         2 . The adhesive layer-equipped transparent surface material according to  claim 1 , wherein the layer portion is made of a cured product of a layer portion-forming curable resin composition comprising the following curable compound (II) and the following non-curable oligomer (D):
 Curable compound (II): at least one curable compound which undergoes a curing reaction at the time of curing the curable resin composition, provided that at least one of said at least one curable compound has a hydroxy group which is not reactive at the time of curing the curable resin composition;   Non-curable oligomer (D): an oligomer which does not undergo a curing reaction with the curable compound (II) at the time of curing the curable composition and which has a hydroxy group.   
     
     
         3 . The adhesive layer-equipped transparent surface material according to  claim 2 , wherein the curable compound (II) contains a monomer which has a curable group and a hydroxy group. 
     
     
         4 . The adhesive layer-equipped transparent surface material according to  claim 3 , wherein the curable compound (II) contains an oligomer (A′) which has a curable group and has a number average molecular weight of from 1,000 to 100,000, and a monomer (B′) which has a curable group and has a molecular weight of from 125 to 600; and the monomer (B′) contains a monomer (B 3 ) having a hydroxy group. 
     
     
         5 . The adhesive layer-equipped transparent surface material according to  claim 4 , wherein the non-curable oligomer (D) is a polyoxyalkylene polyol, and the oligomer (A′) is a urethane oligomer synthesized by using a polyoxyalkylene polyol and a polyisocyanate as raw materials. 
     
     
         6 . The adhesive layer-equipped transparent surface material according to  claim 4 , wherein the oligomer (A′) has an acryl group, and at least a part of the monomer (B′) has a methacryl group. 
     
     
         7 . The adhesive layer-equipped transparent surface material according to  claim 4 , wherein the monomer (B 3 ) contains a hydroxylmethacrylate which has a C 3-8  hydroxyalkyl group having from 1 to 2 hydroxy groups. 
     
     
         8 . The adhesive layer-equipped transparent surface material according to  claim 4 , wherein the monomer (B′) contains a monomer (B 4 ) selected from an alkyl methacrylate having a C 8-22  alkyl group. 
     
     
         9 . The adhesive layer-equipped transparent surface material according to  claim 1 , wherein the layer portion-forming curable resin composition does not contain a chain transfer agent, or contains a chain transfer agent in an amount of at most 1 part by mass per 100 parts by mass of the curable compound (II). 
     
     
         10 . The adhesive layer-equipped transparent surface material according to  claim 1 , wherein the layer portion-forming curable resin composition contains a photo-polymerization initiator (C 2 ), and the curable compound (II) is a photo-curable compound. 
     
     
         11 . The adhesive layer-equipped transparent surface material according to  claim 1 , wherein the transparent surface material is a protective plate for a display device. 
     
     
         12 . The adhesive layer-equipped transparent surface material according to  claim 1 , which further has a removable protective film covering the surface of the adhesive layer. 
     
     
         13 . A process for producing the adhesive layer-equipped transparent surface material as defined in  claim 12 , which comprises the following steps (a) to (e):
 (a) a step of applying a liquid barrier portion-forming curable composition to a peripheral portion of the surface of the transparent surface material to form an uncured barrier portion,   (b) a step of supplying a layer portion-forming curable resin composition to a region surrounded by the uncured barrier portion,   (c) a step of overlaying, in a reduced pressure atmosphere of at most 100 Pa, a protective film-bonded supporting surface material on the layer portion-forming curable resin composition so that the protective film is in contact with the layer portion-forming curable resin composition, to obtain a laminate wherein an uncured layer portion made of the layer portion-forming curable resin composition, is sealed by the transparent surface material, the protective film and the uncured barrier portion,   (d) a step of curing the uncured layer portion and the uncured barrier portion in a state where the laminate is held in an elevated pressure atmosphere of at least 50 kPa, to form an adhesive layer having a layer portion and a barrier portion, and   (e) a step of removing the supporting surface material from the protective film.   
     
     
         14 . A display device comprising a display panel and the adhesive layer-equipped transparent surface material as defined in  claim 1 , bonded to the display panel so that the adhesive layer is in contact with the display panel. 
     
     
         15 . The display device according to  claim 14 , wherein the display panel is a liquid crystal display panel of in-plane switching system. 
     
     
         16 . A process for producing the display device as defined in  claim 14 , which comprises laminating and bonding, in a reduced pressure atmosphere of at most 100 Pa, the display panel and the adhesive layer-equipped transparent surface material so that the adhesive layer is in contact with the display panel.