Patent ID: 7686999
Filing Date: 2010-03-30
Classification: B29C,B29K

Abstract:
1. A manufacturing method of a polymer film, including steps of: casting dope including polymer and solvent on a support for forming a casting film; peeling said casting film as a wet film from said support after said casting film becomes self-supporting by cooling solidification; feeding said wet film to a pin tenter and drying in said pin tenter said wet film to be said polymer film, said polymer film satisfying K2≦K1, when K1 is a maximum value of X-ray diffraction intensity in a range of 0≦2θ≦10 and K2 is a maximum value of X-ray diffraction intensity in a range of 10≦2θ≦20, in an X-ray analysis chart obtained by reflection method in which an angle between an extended line of an entering X-ray and a reflected X-ray is determined as 2θ(°); and feeding said polymer film satisfying K2≦K1 to a clip tenter and stretching in said clip tenter said polymer film in the width direction thereof at a stretch rate in a range of 15% to 40%.