Method of producing cellulose acylate dope and solution casting method
AssigneeFuji Photo Film Co., Ltd.
InventorMasaru Sugiura
Life of this patent
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Abstract
One of silicon dioxide particles and an acid whose pKa in water at 25° C. is from 1.9 to 4.5 is mixed in a polymer solution, such that a first liquid may be obtained, and another one is added to the first liquid. Thus a dope is obtained. Otherwise, a solvent, silicon dioxide particles and an acid whose acid dissociation constant (pKa) in water at 25° C. is from 1.9 to 4.5 are mixed, such that a second liquid in which a concentration of said acid is 0.5 wt. % may be obtained. The second liquid is added to a polymer solution, and thus a dope is obtained. A cellulose acylate film produced from each dope can be peeled from a support adequately, and aggregation of the particles are reduced. Therefore, a film whose optical properties are excellent is produced at high speed.
Claims11
A method of producing a cellulose acylate dope, comprising steps of:
- first mixing into a cellulose acylate solution one of particles containing silicon dioxide and an acid whose acid dissociation constant in water at 25° C. is from 1.9 to 4.5, such that a mixture liquid may be obtained;
- and
- second mixing another one of said particles and said acid into said mixture liquid, such that said cellulose acylate dope may be obtained.
A method of producing a cellulose acylate dope, comprising steps of:
- feeding a cellulose acylate solution;
- mixing a solvent, particles containing silicon dioxide and an acid whose acid dissociation constant in water at 25° C. is from 1.9 to 4.5, such that a mixture liquid in which concentration of said acid is at most 0.5 wt. % may be obtained;
- and
- mixing said mixture liquid to said cellulose acylate solution in an inline mixing manner, such that said cellulose acylate dope may be obtained.
A solution casting method comprising steps of:
- first mixing into a cellulose acylate solution one of particles containing silicon dioxide and an acid whose acid dissociation constant in water at 25° C. is from 1.9 to 4.5, such that a mixture liquid may be obtained;
- second mixing another one of said particles and said acid into said mixture liquid, such that a first dope may be obtained;
- casting from a casting die onto a running support said first dope with a second dope which is different from said first dope, so as to form a casting film having a first layer of said first dope and a second layer of said second dope, said first dope contacting to said support;
- peeling said casting film as a film;
- and
- drying said peeled film.
A solution casting method comprising steps of:
- feeding a cellulose acylate solution;
- first mixing a solvent, particles containing silicon dioxide and an acid whose acid dissociation constant in water at 25° C. is from 1.9 to 4.5, such that a mixture liquid in which a concentration of said acid is at most 0.5 wt. % may be obtained;
- second mixing said mixture liquid to said cellulose acylate solution, such that said cellulose acylate dope maybe obtained;
- casting from a casting die onto a running support said first dope with a second dope which is different from said first dope, so as to form a casting film having a first layer of said first dope and a second layer of said second dope, said first dope contacting to said support;
- peeling said casting film as a film;
- and
- drying said peeled film.
Dependencies are inferred from the claim text.