| 摘要 |
The present invention provides a method for producing a cellulose acylate film comprising: a foreign matter evaluation step for arbitrarily extracting a part of a cellulose acylate resin, which is a raw material before being melted by an extruder, melting the part of raw material to prepare a sample with a thickness of 300 mum or less, and observing the sample by a polarization microscope to evaluate whether the sample has the number of foreign matters of 30 pieces/mm<SUP>3 </SUP>or less; a resin supply step for placing into the extruder a raw material selected by the foreign matter evaluation step as the raw material having the number of foreign matters of 30 pieces/mm<SUP>3 </SUP>or less; an extrusion step for melting the raw material by the extruder and extruding the raw material as a molten resin into a pipe for supply to a die; and a film formation step for discharging the molten resin extruded to the pipe from the die onto a traveling or rotating cooling support in a form of sheet to cool and solidify the sheet.
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