Method for producing polyester-based thermoplastic film, method for inspecting polyester-based thermoplastic film, polyester-based thermoplastic film or resin material thereof

摘要

The present invention provides a method for producing a polyester-based thermoplastic film capable of suppressing the occurrence of die lines on the surface of a resin film. Moreover, the manufacturing method of the polyester-type thermoplastic film etc. which can estimate beforehand the presence or absence of generation | occurrence | production of die line are provided. In a method for producing a polyester-based thermoplastic film in which a heated molten resin is discharged from a die and then cooled and solidified to form a film, the total amount of free terephthalic acid contained in a sublimate generated from the heated molten resin And the ratio of the total amount of liberated bis (2-hydroxyethyl) terephthalate satisfies the relationship of the following formula [1]: A method for producing a polyester-based thermoplastic film. 0 terephthalic acid / bis (2-hydroxyethyl) terephthalate 1.02 [1] [Selection] FIG.