US 12,479,148 B2
Film and method of producing the same
Hiroshi Aruga, Chiyoda-ku (JP); Yoshiaki Higuchi, Chiyoda-ku (JP); Yuya Horiguchi, Chiyoda-ku (JP); and Junetsu Nakamura, Chiyoda-ku (JP)
Assigned to AGC INC., Tokyo (JP)
Filed by AGC INC., Tokyo (JP)
Filed on Oct. 19, 2022, as Appl. No. 18/047,721.
Application 18/047,721 is a continuation of application No. PCT/JP2021/015893, filed on Apr. 19, 2021.
Claims priority of application No. 2020-076243 (JP), filed on Apr. 22, 2020.
Prior Publication US 2023/0065010 A1, Mar. 2, 2023
Int. Cl. B29C 48/88 (2019.01); B29C 48/00 (2019.01); B29C 48/08 (2019.01); C08F 214/24 (2006.01); C08J 5/18 (2006.01); B29D 7/01 (2006.01); B29K 23/00 (2006.01); B29K 27/18 (2006.01); B29K 105/00 (2006.01); B29L 7/00 (2006.01)
CPC B29C 48/914 (2019.02) [B29C 48/022 (2019.02); B29C 48/08 (2019.02); B29C 48/911 (2019.02); B29C 48/9135 (2019.02); C08F 214/245 (2013.01); C08J 5/18 (2013.01); B29K 2023/08 (2013.01); B29K 2027/18 (2013.01); B29K 2105/0085 (2013.01); B29K 2995/0026 (2013.01); B29L 2007/008 (2013.01); C08F 2800/10 (2013.01); C08J 2327/18 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of producing a film comprising a copolymer having a tetrafluoroethylene-based unit and an ethylene-based unit, comprising:
melting a copolymer comprising a copolymer having a tetrafluoroethylene-based unit and an ethylene-based unit such that a melt comprising the copolymer is obtained;
continuously extruding the melt through a die to form the melt into a sheet shape; and
passing the melt extruded in the sheet shape between a pair of a rigid roll and an elastic roll or bringing the melt extruded in the sheet shape into contact with a rigid roll or an elastic roll, and a subsequent stage roll placed at a subsequent stage, for cooling such that a film comprising the copolymer is obtained,
wherein the film has a haze in a range of 1.2% to 8.0%, an ultraviolet reflectance of less than 17.0%, and a thickness in a range of 250 to 400 μm, a surface temperature of each of the rigid roll, the elastic roll and the subsequent stage roll is controlled with a heating medium, a temperature of the melt immediately before passing between the rigid roll and the elastic roll or immediately before being in contact with the rigid roll or the elastic roll is in a range of from 200° C. to 330° C., a melting point M of the copolymer is 200° C. or more, and an average of a heating medium temperature of the rigid roll and a heating medium temperature of the elastic roll or an average of a heating medium temperature of the rigid roll or the elastic roll and a heating medium temperature of the subsequent stage roll is designated as T (° C.), T×M is 31,000 or less.