| 摘要 |
PURPOSE:To provide a polyester film imparting sharp printing or duplication, having durability, concealability, whiteness and surface strength, also having good adhesiveness to both of a hydrophylic resin and a hydrophotic resin and especially suitable for printing, thermal recording and photographic paper by rationalizing cavity distribution. CONSTITUTION:A polyester film having a large number of fine cavities is produced by at least uniaxially orienting a polymer mixture prepared by mixing polyester with a thermoplastic resin incompatible with polyester. A cavity- containing polyester film is constituted by laminating a mixture of a water-soluble resin and a water-insoluble resin to at least the single surface of said film wherein the content of cavities contained in the surface layer up to a depth of 3mum from the surface of the film is 4vol.% or less and the average cavity content of the entire layer is 8-50vol.%. |
