| 摘要 |
PURPOSE:To improve whiteness, optical density and the properties of concealment and adhesion between ink and an adhesive by specifying the percentage of inner voids, optical density and surface roughness of biaxially stretched film as well as the density of imino-type or/and amino-type nitrogen atoms in the long layer part. CONSTITUTION:The subject white biaxially stretched film has 10 to 30% of inner percentage of voids, at least, 0.40 of optical density in 30mum of film thickness, 0.5nm max of surface roughness, and at least, one imino-type or/and amino- type nitrogen atom per 100 carbon atoms in the surface layer up to 10mum of depth from the surface. To meet these requirements, the film surface is treated using corona discharge or plasma in an oxygen-free atmosphere of nitrogen gas, and the imino-type or/and the amino-type nitrogen atom is introduced into the surface part up to 10nm of depth from the surface. Thus it is possible to improve whiteness and concealment as well as enhance the adhesiveness of ink. |
