Antireflection film, polarizing plate and image display device

Abstract

A Method for producing an antireflection film comprising a transparent support, at least one hard coat layer, and a low refractive index layer, the method including: coating a coating composition for forming the hard coat layer on or above the transparent support and curing the coating composition for forming the hard coat layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the hard coat layer; and coating a coating composition for forming the low refractive index layer on or above the hard coat layer and curing the coating composition for forming the low refractive index layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the low refractive index layer.

1 . A method for producing an antireflection film comprising a transparent support, at least one hard coat layer, and a low refractive index layer, the method comprising:
 coating a coating composition for forming the hard coat layer on or above the transparent support and curing the coating composition for forming the hard coat layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the hard coat layer; and   coating a coating composition for forming the low refractive index layer on or above the hard coat layer and curing the coating composition for forming the low refractive index layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the low refractive index layer,   wherein   the coating composition for forming the hard coat layer contains an ethylenically unsaturated monomer and a photo-radical polymerization initiator, and   the coating composition for forming the low refractive index layer contains a fluorine-containing polymer and a hollow silica fine particle, the hollow silica fine particle comprising an outer shell and a single vacancy inside the outer shell, having a refractive index of 1.17 to 1.4, and having an average particle size of 30 to 100% of the thickness of the low refractive index layer.   
     
     
         2 . The method according to  claim 1 , wherein the fluorine-containing polymer is a fluorine-containing copolymer comprising as constituent components a fluorine-containing monomer unit and a constituent unit for imparting crosslinking reactivity. 
     
     
         3 . The method according to  claim 2 , wherein the constituent unit for imparting crosslinking reactivity is a constituent unit which is obtained by polymerization of a monomer having a carboxyl group, a hydroxyl group, an amino group, or a sulfo group and into which a (meth)acryloyl group is introduced by a polymer reaction. 
     
     
         4 . The method according to  claim 1 , wherein the coating composition for forming the low refractive index layer further contains an organosilane compound represented by formula (4): 
       
         
           
           
               
               
           
         
         wherein R 1  represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom; Y represents a single bond, *—COO—**, *—CONH—**, or -*—O—**, * indicates the position bonded to ═C(R 1 )— and ** indicates the position bonded to L; L represents a divalent linking group; n represents 0 or 1; 
         R 10  represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and X represents a hydrolyzable group. 
       
     
     
         5 . The method according to  claim 1 , wherein the coating composition for forming the low refractive index layer further contains a photo-radical polymerization initiator. 
     
     
         6 . A method for producing an antireflection film comprising a transparent support, at least one high refractive index layer, and a low refractive index layer, the method comprising:
 coating a coating composition for forming the high refractive index layer on or above the transparent support and curing the coating composition for forming the high refractive index layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the hard coat layer; and   coating a coating composition for forming the low refractive index layer on or above the hard coat layer and curing the coating composition for forming the low refractive index layer upon irradiation with light in an atmosphere at an oxygen concentration of 1% or less to form the low refractive index layer,   wherein   the coating composition for forming the high refractive index layer contains an inorganic fine particle comprising, as a main component, a titanium dioxide containing at least one element selected from the group consisting of cobalt, aluminum, and zirconium, the coating composition for forming the high refractive index layer further containing an ethylenically unsaturated monomer and a photo-radical polymerization initiator, and   the coating composition for forming the low refractive index layer contains a fluorine-containing polymer and a hollow silica fine particle, the hollow silica fine particle comprising an outer shell and a single vacancy inside the outer shell, having a refractive index of 1.17 to 1.4, and having an average particle size of 30 to 100% of the thickness of the low refractive index layer.   
     
     
         7 . The method according to  claim 1 , wherein the fluorine-containing polymer is a fluorine-containing copolymer comprising as constituent components a fluorine-containing monomer unit and a constituent unit for imparting crosslinking reactivity. 
     
     
         8 . The method according to  claim 7 , wherein the constituent unit for imparting crosslinking reactivity is a constituent unit which is obtained by polymerization of a monomer having a carboxyl group, a hydroxyl group, an amino group, or a sulfo group and into which a (meth)acryloyl group is introduced by a polymer reaction. 
     
     
         9 . The method according to  claim 1 , wherein the coating composition for forming the low refractive index layer further contains an organosilane compound represented by formula (4): 
       
         
           
           
               
               
           
         
         wherein R 1  represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom; Y represents a single bond, *—COO—**, *—CONH—**, or -*—O—**, * indicates the position bonded to ═C(R 1 )— and ** indicates the position bonded to L; L represents a divalent linking group; n represents 0 or 1; 
         R 10  represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and X represents a hydrolyzable group. 
       
     
     
         10 . The method according to  claim 1 , wherein the coating composition for forming the low refractive index layer further contains a photo-radical polymerization initiator.