POLYSTYRENE-BASED ORIENTED FILM AND PRODUCTIONN OF POLYSTYRENE-BASED ORIENTED FILM

摘要

PURPOSE: To prepare an oriented film consisting of a specific styrene-based resin composition, having specific crystallinity, residual monomer amount and number of foreign matter, excellent in printability and release strength, etc., after deposition and useful as a film for condenser, electrical insulating film, photographic film, etc. CONSTITUTION: This oriented film is composed of a styrene-based resin composition (RC) containing 70-100wt.% of styrene-based polymer having high syndiotactic structure (e.g. a polymer consisting of 80-100mol% styrene recurring unit and 0-20mol;% p-methylstyrene recurring unit) and has =35% crystallinity, =200ppm residual monomer component amount and =1000/cm3 number of foreign matter having 9m size. The oriented film is obtained by extruding RC at =330 deg.C for 60min while melting and filtering the RC, cooling and biaxially orienting the extruded RC and subjecting the oriented film to heat treatment under the condition in which A value of the formula [T is a heat treating temperature (K); (t) is a heat treating time (sec); (d) is a film thickness (m)] is 110-1 to 5102 .