Patent ID: 8435432
Filing Date: 2013-05-07
Classification: B29C,B29K,G02B

Abstract:
1. A method for producing a transparent polymer film, which comprises heat-treating a polymer film selected from the group consisting of cellulose ester films, polycarbonate films, cyclo-olefin polymer films, poly alylate films, poly sulfone films, vinyl polymer films, polyamide films, polyimide films, cyclo-olefin copolymer films and poly norbornene films at a temperature T (unit, ° C.) satisfying a condition of the following formula (1): wherein Tc represents the crystallization temperature (unit, ° C.) of the polymer film before the heat treatment; and Tm wherein the method is for producing a transparent polymer film satisfying the following formula (2): wherein Re represents the retardation (unit, nm) in the in-plane direction; and Rth means the retardation (unit, nm) in the film-thickness direction.