Forgery-preventing film

Abstract

Disclosed is a forgery-preventing film having, on one side of a first layer (A) comprising a thermoplastic resin, a second layer (B) comprising a thermoplastic resin wherein said film satisfying at least one of the following conditions: Condition 1: one side of said first layer (A) is treated to prevent forgery and said second layer (B) is formed on the surface of the treated side of said first layer (A); Condition 2: said second layer (B) comprises at least two thermoplastic resins of different melt viscosities; Condition 3: porosity of said second layer (B) is greater than porosity of said first layer (A); and Condition 4: a polymer net is formed on one side of said first layer (A) and said second layer (B) is formed on the surface having the polymer net.

What is claimed is:  
     
         1 . A forgery-preventing film having, on one side of a first layer (A) comprising a thermoplastic resin, a second layer (B) comprising a thermoplastic resin wherein said film satisfying at least one of Conditions 1 to 4 below: 
 Condition 1: one side of said first layer (A) is treated to prevent forgery and said second layer (B) is formed on the surface of the treated side of said first layer (A);    Condition 2: said second layer (B) comprises at least two thermoplastic resins of different melt viscosities;    Condition 3: porosity of said second layer (B) is greater than porosity of said first layer (A); and    Condition 4: a polymer net is formed on one side of said first layer (A) and said second layer (B) is formed on the surface having the polymer net.    
     
     
         2 . The forgery-preventing film according to  claim 1 , wherein a third layer (C) is formed on the back side of said first layer (A).  
     
     
         3 . The forgery-preventing film according to  claim 1  wherein said first layer (A) is of a multilayer structure.  
     
     
         4 . The forgery-preventing film according to  claim 1  satisfying Condition 1.  
     
     
         5 . The forgery-preventing film according to  claim 4  wherein both surfaces of said first layer (A) are treated to prevent forgery, and said second layer (B) and said third layer (C) are formed on each of the treated surfaces of said first layer (A).  
     
     
         6 . The forgery-preventing film according to  claim 4  wherein said forgery-preventing treatment is embossing.  
     
     
         7 . The forgery-preventing film according to  claim 4  wherein said forgery-preventing treatment is printing.  
     
     
         8 . The forgery-preventing film according to  claim 4  wherein the opacity is from 1 to 60 percent.  
     
     
         9 . The forgery-preventing film according to  claim 4  wherein the porosity of said first layer (A) is from 0 to 40 percent and the porosity of said second layer (B) is greater than 20 percent and less than or equal to 40 percent.  
     
     
         10 . The forgery-preventing film according to  claim 9  wherein a third layer (C) with a porosity of greater than 20 percent and less than or equal to 40 percent is formed on the back side of said first layer (A).  
     
     
         11 . The forgery-preventing film according to  claim 9  which has an opacity of greater than 60 percent and less than or equal to 99 percent.  
     
     
         12 . The forgery-preventing film according to  claim 1  satisfying Condition 2.  
     
     
         13 . The forgery-preventing film according to  claim 12  wherein the difference in the melt viscosity of said two thermoplastic resins of differing melt viscosity contained in said second layer (B) is greater than 50 Pa·s.  
     
     
         14 . The forgery-preventing film according to  claim 12  wherein a third layer (C) comprising at least two thermoplastic resins of different melt viscosities is formed on the back side of said first layer (A).  
     
     
         15 . The forgery-preventing film according to  claim 14  wherein the difference in melt viscosity of said two thermoplastic resins of differing melt viscosity contained in said third layer (C) is greater than 50 Pa·s.  
     
     
         16 . The forgery-preventing film according to  claim 12  which has an opacity of from 1 to 60 percent.  
     
     
         17 . The forgery-preventing film according to  claim 1  satisfying Condition 3.  
     
     
         18 . The forgery-preventing film according to  claim 17  wherein the ratio (A/B) of the porosity of said first layer (A) to that of said second layer (B) is less than or equal to ⅓.  
     
     
         19 . The forgery-preventing film according to  claim 17  wherein both said first layer (A) and said second layer (B) comprise an inorganic finepowder and/or an organic filler, and the average particle diameter of the inorganic finepowder and/or the organic filler contained in said second layer (B) is larger than the average particle diameter of the inorganic finepowder and/or the organic filler contained in said first layer (A).  
     
     
         20 . The forgery-preventing film according to  claim 17  wherein a third layer (C) comprising a thermoplastic resin is formed on the back side of said first layer (A) and the porosity of said third layer (C) is greater than that of said first layer (A).  
     
     
         21 . The forgery-preventing film according to  claim 20  wherein the ratio (A/C) of the porosity of said first layer (A) to that of said third layer (C) is less than or equal to ⅓.  
     
     
         22 . The forgery-preventing film according to  claim 20  wherein both said first layer (A) and said third layer (C) comprise an inorganic finepowder and/or an organic filler, and the average particle diameter of the inorganic finepowder and/or the organic filler contained in said third layer (C) is larger than the average particle diameter of the inorganic finepowder and/or the organic filler contained in said first layer (A).  
     
     
         23 . The forgery-preventing film according to  claim 17  which has an opacity of from 10 to 60 percent.  
     
     
         24 . The forgery-preventing film according to  claim 1  satisfying Condition 4.  
     
     
         25 . The forgery-preventing film according to  claim 24  wherein said polymer net is treated to prevent forgery.  
     
     
         26 . The forgery-preventing film according to  claim 24  wherein said film is stretched in at least one direction.  
     
     
         27 . The forgery-preventing film according to  claim 24  wherein said polymer net is comprised of a thermoplastic resin tape and has a network structure in the form of a grid.  
     
     
         28 . The forgery-preventing film according to  claim 27  wherein a constituent member (T) in the traverse direction of said polymer net is unstretched thermoplastic resin tape.  
     
     
         29 . The forgery-preventing film according to  claim 24  which has an average traverse and longitudinal tear strength as described in JIS K7128 is greater than or equal to 20 gf.  
     
     
         30 . The forgery-preventing film according to  claim 24  wherein a third layer (C) is formed on the back side of said first layer (A).  
     
     
         31 . The forgery-preventing film according to  claim 24  wherein both sides of said first layer (A) are treated to prevent forgery, and a second layer (B) and a third layer (C) are formed on each of the treated surfaces of said first layer (A).  
     
     
         32 . The forgery-preventing film according to  claim 24  wherein said second layer (B) and said third layer (C) have an opacity of from 1 to 99 percent.