| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laminating coextrusion biaxially oriented polyester film in which texts, symbols, images, etc., can be marked by a laser marking excellently and eternally and which is suitable for the manufacturing of ID cards or labels. <P>SOLUTION: The coextrusion biaxially stretched film comprises polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), and comprises at least two layers which are a base layer and outer layers of one or more layers, and when the film comprises the PET, copolymerization monomers other than ethylene glycol and terphthalic acid are included as a structural unit, when the film comprises the PEN, copolymerization monomers other than ethylene glycol and 2,6-naphthalene dicarboxylic acid are included as a structural unit, and the base layer contains a white pigment and a laser absorbing agent coated with a polymer which can be carbonized. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
