| 摘要 |
<p>PURPOSE:To obtain a base film for an inexpensive private card excellent in forgery preventing effect, by a method wherein at least the contact surfaces of two layers respectively have recessed and protruding structural surfaces having a specific depth or more and said recessed and protruding structural surfaces are closely brought into contact with each other in a mutually meshed state. CONSTITUTION:A base film for a prepaid card takes a laminate structure of two or more layers, pref., two-three layers, especially pref., 3 or more layers and the contact surfaces of both surface layers (A) and an inner layer (B) have recessed and protruding structural surfaces respectively and are closely brought into contact with each other in such a state that the recessed and protruding structural surfaces are meshed mutually. L shows the depth of unevenness and is 5mum or more. Further, P shows the length of one cycle of unevenness and is pref. 5cm or less. When the depth (L) of the above-mentioned unevenness is below 5mum, it is difficult to discriminate this base film from one obtained by a simple lamination method for merely laminating films each having a flat surface and it is difficult to prevent forgery. When the depth (L) is more than 5mum, the lamination due to the above-mentioned lamination method is extremely difficult.</p> |
