| abstract |
A method for producing a film comprises the steps of melting a thermoplastic resin in an extruder having a hopper cooling zone, a feed zone, a compression zone, and a metering zone; discharging a melted resin from the extruder and supplying the same to a die; extruding the melted resin through the die in a sheet-like form; and cooling and solidifying the sheet-like melted resin to produce a film; wherein a relationship between a temperature, T 1 [° C.], of the melted resin in a first half of the feed zone and a temperature, T 2 [° C.], of the melted resin in a second half of the feed zone satisfies a following equation (1): n Tg +30≦ T 2 <T 1 ≦Tg +160 (1) where a glass transition temperature of the resin is denoted by Tg. |