| 摘要 |
PURPOSE: To provide an optically isotropic film with a highly glossy face on one side and a matted face on the other side by calendering the film between a delustered elastomer roller and a highly glossy steel roller after extruding a thermoplastic polymer. CONSTITUTION: A thermoplastic polycarbonate based on bis-(hydroxyphenyl)- alkane and/or -cycloalkane is a best-suited thermoplastic polymer, and after extruding this thermoplastic polymer, this polymer is calendered between a delustered elastomer roller and a highly glossy steel roller, preferably at a temperature of 280-320 deg.C and under a pressure of 80-150 bar to manufacture the film. Alternatively, a molten product of the same thermoplastic polymer as the matted face of the film manufactured by the described method is coated on the matted face and the coated film thus obtained is calendered again between the delustered elastomer roller and the highly glossy steel roller with the highly glossy face of the coated film directed toward the roller of the elastomer material. Thus it is possible to manufacture the optically isotropic extrusion film with a thickness of 600μm or less.
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