Anti-glare optical film and process for preparing the same

Abstract

An anti-glare optical film which reduces in whitening of a screen without sacrificing anti-glare property, and a process for preparing the same. There is provided an anti-glare optical film has an irregular surface, wherein a ratio of areas of the surface having an inclination angle of 1° or less is 20% or less, a ratio of areas of the surface having an inclination angle of 5° or more is 20% or less, and a standard deviation of a height of the surface is 0.2 μm or less. There is also provided a process for preparing an anti-glare optical film.

1 . A process for preparing an anti-glare optical film, comprising the steps of:
 contacting a glass with an aqueous solution containing hydrogen fluoride to obtain a template which comprises the glass having the surface on which a fine irregular shape is formed so that approximately spherical concave shapes are arranged to be substantially compact; and   transferring the irregular shape of the surface of the template onto the surface of a resin film.   
   
   
       2 . The process according to  claim 1 , wherein
 the glass is a quartz glass or a borosilicate glass.   
   
   
       3 . A process for preparing an anti-glare optical film, comprising the steps of:
 forming fine flaw on a surface of a glass,   contacting the glass with an aqueous solution containing hydrogen fluoride to obtain a template which comprises the glass having the surface on which a fine irregular shape is formed; and   transferring the irregular shape of the surface of the template onto the surface of a resin film.   
   
   
       4 . The process according to  claim 3 , wherein the glass is a quartz glass or a borosilicate glass. 
   
   
       5 . The process according to  claim 3 , wherein the fine flaw is formed at a depth of 10 μm or less by blast treatment on the glass surface. 
   
   
       6 . The process according to  claim 5 , wherein the blast treatment is performed using a bead having substantially monodisperse particle diameter distribution. 
   
   
       7 . The process according to  claim 6 , wherein the bead has an average particle diameter of 180 μm or less. 
   
   
       8 . The process according to  claim 5 , wherein the blast treatment is performed at a blast pressure of 0.01 to 0.05 MPa, and at conditions under which the fine flaw is formed so that spherical concave shapes are formed on the glass surface to be substantially compact by contacting with an aqueous solution containing hydrogen fluoride. 
   
   
       9 . The process according to  claim 3 , wherein etching is performed by contact with an aqueous solution containing hydrogen fluoride to such an extent that an etching depth becomes 10-fold or more an average depth of the fine flaw. 
   
   
       10 . The process according to  claim 1 , wherein the template is a tubular glass having the outer surface on which the fine irregular shape is formed, and the irregularity is continuously transferred onto the resin film. 
   
   
       11 . The process according to  claim 1 , wherein the resin film comprises a thermoplastic transparent resin, and an irregular shape of a template is transferred onto its surface by thermal press. 
   
   
       12 . The process according to  claim 1 , wherein the resin film comprises an ionizing radiation curable resin layer formed on the surface of a transparent substrate film. 
   
   
       13 . The process according to  claim 12 , wherein the ionizing radiation curing layer is contacted with the template, and ionizing radiation is irradiated to cure the resin layer, whereby the irregular shape of a template is transferred on the resin layer after curing.