Patent ID: 9272448
Filing Date: 2016-03-01
CPC Classification: B29C,B29K,G02B

Claim Text:
1. A cellulose resin film producing method, comprising in the following order: a casting process of casting a liquid state cellulose resin on a support to form a web; a separating process of separating the web from the support; a first widthwise grasping process of grasping both edges of the web in the width direction of the web, stretching the web with a widthwise stretching ratio of 0.95 to 1.5 times in the width direction of the web, and drying the web while grasping widthwise the both edges of the web; a releasing process of releasing the both edges of the web from the widthwise grasping; a heat treatment process of applying a heat treatment onto only the both edges of the web with an embossing roller in such a way that the embossing roller is heated higher than a glass transition point (Tg) of the cellulose resin and is brought in pressure contact with only the both edges of the web so as to harden the both edges; and a second widthwise grasping process of grasping widthwise the both edges of the web and stretching again the web with a widthwise stretching ratio of 1.2 to 2.0 times in the width direction of the web while grasping widthwise the both edges of the web.