| 摘要 |
PURPOSE: A method for preparing a white polymer film is provided, for improving the print ability and the destaticizing ability and reducing the curling. CONSTITUTION: A white polymer film is prepared by bonding and layering a polyester film layer(an A layer) which is prepared by adding 5-30 percent by weight (based on the weight of a resin) of a white inorganic particle and 0.01-0.05 percent by weight (based on the weight of a resin) of the derivative of metal sulfonate represented by the formula I(R-SO3Me), wherein R represents an alkyl group of C5-C20 and Me represents an alkali earth metal or an alkali metal comprising Li, Na, K and Mg to a polyester resin having a limiting viscosity of 0.6-1.0 dl/g, melting and extruding, and elongating in one direction; and a polypropylene unelongated film layer (a B layer) which is prepared by melting and extruding a polypropylene resin or the copolymer resin, wherein the polypropylene has a melting index of 1-20 g/10min and a melting point of 130-180°C. The white inorganic particle is titanium dioxide, talc, barium sulfate, silica, calcium carbonate or their mixture, and the size is 0.1-0.5 micrometer. Preferably the surface of the A layer is coated to a thickness of 0.01-0.1 g per square meter by using an aqueous coating solution comprising 10-50 percent by weight of an acryl polymer having a mean MW of 10,000-300,000 and a glass transition temperature of 30-100°C. The thickness ratio of the A/B layers is preferably 1/5 - 1/30.
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