Patent ID: 8153044
Filing Date: 2012-04-10
Classification: B29C,B29K,G02F,Y02P

Abstract:
1. A method for heat-treating a thermoplastic film, comprising, after transversely stretching a thermoplastic film, transporting said thermoplastic film in a heat-treating zone using two or more transporting rolls, wherein a ratio (G/D) of an inter-roll distance (G) to a roll lap length (D) is 0.01 to 3, and a ratio (V wherein an Rth/Re ratio of a thickness direction retardation (Rth) to an in-plate retardation (Re) is at least 0.5 and less than 1, and the Rth/Re ratio range is 0.01 to 0.1 in a width direction.