Polarizing film including modified PVA, and optical laminate with the polarizing film

Abstract

[TECHNICAL PROBLEM] Provided a polarizing film which comprising a substrate and a PVA-based resin, wherein it has good adhesion between the substrate and the PVA-based resin to allow the PVA-based resin to become less likely to be peeled off from the substrate during stretching and/or conveyance, and exhibits excellent appearance. [SOLUTION] The polarizing film is obtained by providing a layer of a PVA-based resin on a substrate and stretching the substrate and the PVA-based resin layer together. The PVA-based resin contains a modified PVA, wherein the modified PVA exists in an amount allowing a modification rate with respect to the entire PVA-based resin to be in a range of 0.04 mol % to 1.4 mol %.

What is claimed is: 
     
         1 . A polarizing film obtained by providing a layer of a PVA-based resin on a substrate and stretching the substrate and the PVA-based resin layer together, wherein the PVA-based resin contains a modified PVA, the modified PVA existing in an amount allowing a modification rate with respect to the entire PVA-based resin to be in a range of 0.04 mol % to 1.4 mol %. 
     
     
         2 . The polarizing film as defined in  claim 1 , wherein the modified PVA is an acetoacetyl-modified PVA. 
     
     
         3 . The polarizing film as defined in  claim 1 , wherein the modified PVA exists in an amount of 30 weight % or less, based on 100 weight % of a total amount of the PVA-based resin. 
     
     
         4 . The polarizing film as defined in  claim 1 , which is obtained by stretching the PVA-based resin layer provided on the substrate, at a stretching ratio of at least 5 times. 
     
     
         5 . The polarizing film as defined in  claim 1 , wherein the PVA-based resin layer after the stretching has a thickness of 10 μm or less. 
     
     
         6 . An optical laminate for an image display, comprising the polarizing film as defined in  claim 1 .