| 摘要 |
PURPOSE:To reduce yellowishness by providing a pigment coating layer having a specific compsn. (solid component ratio) and specified in whiteness, brightness, hue, yellowness and thickness on the surface of a microporous. stretched film base layer having specific whiteness. CONSTITUTION:A pigment coating layer having a solid component compsn. consisting of 49.95-75wt.% of white pigment, 0.05-3wt.% of a blue dye and 22-50wt.% of a resin binder is formed on the surface of a microporous stretched film base layer with whiteness of 90% or more composed of a stretched propylene resin film containing a white inorg. fine powder. This pigment coating layer is characterized by that whiteness measured according to JIS L-1074 is 95% or more, brightness measured according to JIS Z-8730 is 95% or more, a hue is -1.0-+1.0, yellowness is -4.0--2.0 and thickness is 3-30mum. Since the propylene type synthetic paper of the base layer is concealed with the white pigment coating layer, whiteness can be enhanced and yellowishness can be reduced. |
