| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermoplastic film and a method of manufacturing the same, in which outer appearance defect caused by thickness unevenness called gauge band, and outer appearance abnormality of film slack and a fold line caused by a wrinkle during conveyance, generated on a roll film manufactured by melt extrusion film formation, are eliminated.SOLUTION: A maximum film thickness De (μm) in a region from an end part to an inner side by 50 mm of the thermoplastic film in a film width direction (TD) and an average film thickness Dc (μm) in a center part of the thermoplastic film satisfy a relation of 1.0≤De/Dc≤3.5. A shrinkage rate in a film extrusion direction (MD) of the film after being left at room temperature for one month is 0.01-0.10%. The method of manufacturing the thermoplastic film is characterized by that a peripheral speed v1 (m/min) of a cast roll 4 in a film forming process and a peripheral speed v2 (m/min) of a cooling roll and a conveying roll 9 are adjusted to satisfy a relation of 0.97≤v2/v1≤1.001. |
