Solution casting method for producing film
AssigneeFuji Photo Film Co., Ltd.
InventorKazuhide Kanemura
Life of this patent
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Abstract
A cope containing TAC is cast from a casting die onto a belt such that a film after the drying may have a thickness at 40 μm. A solvent of the dope solution on the belt evaporates, and thus a gel-like film may be formed. The peeling force of the gel-like film becomes to the maximum when the weight percentage of the remaining solvent in the gel-like film is 25 wt. %. In order to reduce the generation of mura or unevenness of the thickness, the gel-like film is peeled from a belt with a support of a peeling roller, when the weight percentage of the remaining solvent is at most 20 wt. %. The peeled gel-like film is dried in a tenter dryer and a casting chamber to be a film. After cooled in a cooling chamber, the film is wound by a winding device.
Claims21
A solution casting method for producing a polymer film from a dope solution containing a polymer and a solvent, comprising steps of:
- casting said dope solution from a casting die on a substrate to form a gel-like film;
- drawing said gel-like film in a tangential direction of said substrate to peel said gel-like film from said substrate at a peeling speed of at least 10 m/min;
- regulating to less than 20 mm a movement range in which a peeling position of said gel-like film moves on said substrate;
- and
- drying said peeled gel-like film so as to obtain said polymer film.
Dependencies are inferred from the claim text.