Polyvinyl alcohol polymer film and polarization film

Abstract

A polyvinyl alcohol polymer film includes a polyvinyl alcohol polymer and a plasticizer selected from the group consisting of ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylolpropane. The amount of the polyvinyl alcohol polymer eluted when a 10 cm square of the polyvinyl alcohol polymer film is left in 1 liter of water of 50° C. for 4 hours is from 1 to 100 ppm. The film has only a small number of defects and is useful as raw material for producing a polarization film.

What is claimed is:  
     
         1 . A polyvinyl alcohol polymer film in which the amount of a polyvinyl alcohol polymer eluted when a 10 cm square polyvinyl alcohol polymer film is left in 1 liter of water of 50° C. for 4 hours is from 1 to 100 ppm.  
     
     
         2 . The polyvinyl alcohol polymer film according to  claim 1  wherein the content of an alkali metal compound is 0.5% by weight or less based on the polyvinyl alcohol polymer.  
     
     
         3 . The polyvinyl alcohol polymer film according to  claim 2  wherein the alkali metal compound is sodium acetate.  
     
     
         4 . The polyvinyl alcohol polymer film according to  claim 1  which is used for a polarization film.  
     
     
         5 . The polyvinyl alcohol polymer film according to  claim 2  which is used for a polarization film.  
     
     
         6 . The polyvinyl alcohol polymer film according to  claim 3  which is used for a polarization film.  
     
     
         7 . A polarization film made by using a polyvinyl alcohol polymer film for a polarization film of  claim 4 .  
     
     
         8 . A polarization film made by using a polyvinyl alcohol polymer film for a polarization film of  claim 5 .  
     
     
         9 . A polarization film made by using a polyvinyl alcohol polymer film for a polarization film of  claim 6 .  
     
     
         10 . A method of producing a polyvinyl alcohol polymer film of  claim 2  comprising film-forming using as a raw material a polyvinyl alcohol polymer in which the content of an alkali metal compound is 0.5% by weight or less based on the polyvinyl alcohol polymer.  
     
     
         11 . The method of producing a polyvinyl alcohol polymer film for a polarization film according to  claim 10  comprising film-forming using a film formation raw material prepared at temperatures of 150° C. or less containing a polyvinyl alcohol polymer in which the content of an alkali metal compound is 0.5% by weight or less based on the polyvinyl alcohol polymer.