Thin film forming method, optical film, polarizing film and image display method

Abstract

A method of forming a layer or layers are disclosed which comprises the steps of transporting a substrate having a first surface and a second surface on the side opposite the first surface to a gap formed between a first electrode and a second electrode opposing each other, the second surface having a coefficient of kinetic friction of not more than 0.9; and subjecting the first surface of the substrate to plasma discharge treatment to form the layer at atmospheric pressure or at approximately atmospheric pressure while supplying a reactive gas to the gap.

What is claimed is:  
     
         1 . A method of forming a layer or layers, the method comprising the steps of: 
 (a) transporting a substrate having a first surface and a second surface on the side opposite the first surface to a gap formed between a first electrode and a second electrode opposing each other, the second surface having a coefficient of kinetic friction of not more than 0.9; and    (b) subjecting the first surface of the substrate to plasma discharge treatment to form the layer at atmospheric pressure or at approximately atmospheric pressure while supplying a reactive gas to the gap.    
     
     
         2 . A method of forming a layer or layers, the method comprising the step of: 
 subjecting the surface of a substrate, the substrate having a thickness of from 10 to 60 μm and having a tensile strength of not less than 1.4×10 2  N/mm 2 , to plasma discharge treatment to form the layer at atmospheric pressure or at approximately atmospheric pressure at a gap formed between a first electrode and a second electrode opposing each other while supplying a reaction gas to the gap.    
     
     
         3 . A method of forming a first layer, the method comprising the step of: 
 subjecting the surface of a substrate or a second layer provided on a substrate to plasma discharge treatment to form the first layer at atmospheric pressure or at approximately atmospheric pressure at a gap formed between a first electrode and a second electrode opposing each other while supplying a reaction gas to the gap, wherein the substrate has a moisture content of not more than 4% at 23° C. and 80% RH.    
     
     
         4 . A method of forming a first layer, the method comprising the step of: 
 subjecting the surface of a substrate or a second layer provided on a substrate to plasma discharge treatment to form the first layer at atmospheric pressure or at approximately atmospheric pressure at a gap formed between a first electrode and a second electrode opposing each other while supplying a reaction gas to the gap, wherein the substrate has been stretched in the transverse direction.    
     
     
         5 . The method of  claim 3  or  4 , wherein the second layer provided on the substrate is a hardened resin layer in which a monomer or an oligomer each having an ethylenically unsaturated double bond has been polymerized and hardened.  
     
     
         6 . The method of any one of claims  1  through  5 , wherein the substrate is a cellulose ester film.  
     
     
         7 . The method of  claim 6 , wherein the cellulose ester film comprises a cellulose ester having a total acyl substitution degree of from 2.55 to 2.95.  
     
     
         8 . An optical film having a layer or layers formed according to the method of claims  1  through  7 .  
     
     
         9 . A polarizing plate employing the optical film of  claim 8  as the protective film.  
     
     
         10 . An image display employing the optical film of  claim 8.