Transparent conductive film and manufacturing method therefor

Abstract

The present invention is a transparent conductive film having a flexible transparent base and a transparent conductive layer made of a crystalline conductive metal oxide that is formed on one surface of the flexible transparent base, in which the thickness of the flexible transparent base is 80 μm or less, and the difference H 1 −H 2 between the dimensional change rate H 1 when the transparent conductive film is heated at 140° C. for 30 minutes and the dimensional change rate H 2 when the transparent conductive layer is removed from the transparent conductive film by etching and the transparent conductive film is heated at 140° C. for 30 minutes is −0.02 to 0.043%. Because of that, the level difference at the pattern boundary when the film is assembled into a touch panel, etc. is decreased and the deterioration of the appearance can be also suppressed.

What is claimed is: 
     
         1 . A method of manufacturing a transparent conductive film having a flexible transparent base and a transparent conductive layer made of a crystalline conductive metal oxide that is formed on one surface of the flexible transparent base, comprising the steps of:
 preparing a flexible transparent base having a thickness of 80 μm or less,   forming the transparent conductive layer by a sputtering method, wherein an amorphous transparent conductive layer made of an amorphous conductive metal oxide if formed on the flexible transparent base, and   annealing the amorphous transparent conductive layer to be converted into a crystalline transparent conductive layer, wherein   the annealing temperature in the step of annealing treatment is 70 to 140° C.,   a thickness of the transparent conductive layer is 10 to 30 nm,   the flexible transparent base has a transparent film base, the transparent conductive film has at least one undercoat layer provided between the transparent film base and the transparent conductive layer,   the undercoat layer is formed of an inorganic substance, an organic substance, or a mixture of inorganic and organic substances.   
     
     
         2 . The method of manufacturing a transparent conductive film according to  claim 1 , wherein
 the dimensional change rate in the step of annealing treatment is 0 to −0.34%.   
     
     
         3 . The method of manufacturing a transparent conductive film according to  claim 1 , further comprising a patterning step of removing a part of the crystalline transparent conducive layer by etching to form a pattern forming part where the transparent conductive layer is on a flexible transparent base and a pattern opening part where the transparent conductive layer is not on the flexible transparent base. 
     
     
         4 . The method of manufacturing a transparent conductive film according to  claim 3 , wherein the difference H 1 −H 2  between the dimensional change rate H 1  when the transparent conductive film is heated at 140° C. for 30 minutes and the dimensional change rate H 2  when the transparent conductive layer is removed from the transparent conductive film by etching and the transparent conductive film is heated at 140° C. for 30 minutes is −0.043 to 0.02%. 
     
     
         5 . The method of manufacturing a transparent conductive film according to  claim 3 , wherein the transparent conductive layer is patterned and is bonded to a glass plate with an acrylic-based pressure-sensitive adhesive layer, wherein a level difference at a boundary between a pattern forming part where the transparent conductive layer is formed and a pattern opening part where the transparent conductive layer is removed is 168 μm or less. 
     
     
         6 . A method of manufacturing a transparent conductive film having a flexible transparent base and a transparent conductive layer made of a crystalline conductive metal oxide that is formed on one surface of the flexible transparent base, wherein
 the transparent conductive layer is patterned, and the transparent conductive film has a pattern forming part where the transparent conductive layer is on a flexible transparent base and a pattern opening part where the transparent conductive layer is not on the flexible transparent base, the difference h 1 −h 2  between the dimensional change rate h 1  of the pattern forming part and the dimensional change rate h 2  of the pattern opening part when the transparent conductive film is heated at 140° C. for 30 minutes is −0.043 to 0.02%,   comprising the steps of:
 preparing a flexible transparent base having a thickness of 80 μm or less, 
 forming the transparent conductive layer by a sputtering method, wherein an amorphous transparent conductive layer made of an amorphous conductive metal oxide if formed on the flexible transparent base, and 
 annealing the amorphous transparent conductive layer to be converted into a crystalline transparent conductive layer, wherein 
 the annealing temperature in the step of annealing treatment is 70 to 140° C., 
   a thickness of the transparent conductive layer is 10 to 30 nm,   the transparent conductive film has at least one undercoat layer provided between the transparent film base and the transparent conductive layer, and   the undercoat layer is formed of an inorganic substance, an organic substance, or a mixture of inorganic and organic substances, and   the transparent conductive layer is bonded to a glass plate with an acrylic-based pressure-sensitive adhesive layer, wherein a level difference at a boundary between the pattern forming part where the transparent conductive layer is formed and the pattern opening part where the transparent conductive layer is removed is 168 μm or less.   
     
     
         7 . The method of manufacturing a transparent conductive film according to  claim 6 , wherein
 the dimensional change rate in the step of annealing treatment is 0 to −0.34%.   
     
     
         8 . The method of manufacturing a transparent conductive film according to  claim 6 , further comprising a patterning step of removing a part of the crystalline transparent conducive layer by etching to form a pattern forming part where the transparent conductive layer is on a flexible transparent base and a pattern opening part where the transparent conductive layer is not on the flexible transparent base.