| 摘要 |
PROBLEM TO BE SOLVED: To make forgery and alteration of a card difficult by specifying specific permittivity and apparent density of a film composite material obtained by adhesively laminating a film at least on one side surface of a porous base material, thereby performing low permittivity. SOLUTION: This film composite material is a laminate obtained by adhering a film at least on one side surface of a porous base material. And, the air is contained in the laminate to lower its specific permittivity or a random structure is given by the porous base material. This composite material has specific permittivity of 1.2 to 2.8, and apparent density of 0.3 to 1.3g/cm<3> . As the porous base material, cloth having METSUKE amount (weight per square meter) of particularly 5 to 200g/m<2> is more preferable from the viewpoint of folding crease resistance and strength. As material of the film, particularly polyethylene terephthalate has excellent electrical and mechanical characteristics and can be preferably used. |
