SURFACE ROUGHENED FILM AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain a polyester film excellent in transparency and easy slippage by providing fine projections based on a thermoplastic resin to the surface of a specific film or laminated film. CONSTITUTION:A non-stretched film composed of a mixture of 99.99-97wt.% of a thermoplastic polyester resin and 0.01-3wt.% of a thermoplastic resin or a non-stretched film wherein the mixture is laminated to other polymer so as to form at least one surface layer, is stretched by 1.5 times or more at least in one direction within the temp. range of the glass transition temp. of the thermoplastic polyester resin or thermoplastic resin to produce a surface roughened film having fine projections based on the thermoplastic resin. The thermoplastic resin to be used has glass transition temp. higher than that of the thermoplastic polyester resin, critical surface tension different by one dyne/cm or more from that of the thermoplastic polyester resin and melt viscosity of 500-50000 poise at 280 deg.C at a shear rate of 10<2>sec<-1>.