Fuji Photo Film Company, Limited

Fujifilm Corporation

Tadahiro Tsujimoto

Yukihiro Katai

Hidekazu Yamazaki

Misao Takahashi

Tadahisa Sato

Katsuyoshi Yamakawa

Toshikazu Nakamura

Hiroshi Onishi

Takashi Ito

Yoshinori Suzuki

Yoshio Sakakibara

Toshinao Arai

Satoru Fujisaki

Morio Hashimoto

Takuro Nishimura

Nobuo Takeuchi

The solution film-forming method is provided in which the absolute filtration accuracy for a cellulose acylat solution can be improved and filtration throughput can be increased without reducing the pore size of a filtering material. A dope stock solution to be filtrated is first introduced into a body feed tank and a filter aid from a filter aid tank is added and dispersed. As the filter aid, an aid including SiO2 in 50% or more and a cellulose-based aid are mixed for use. The dope stock solution in which the filter aid is dispersed is introduced into a filter machine and subjected to filtration while forming a cake on the surface of the filtering material. After the filtration, a cleaning solvent is supplied in circulation from a cleaning solvent tank, and the cake is discharged as slurry. The filter aid is separated from the slurry by a separating device and burned in a burning device. Then, a regenerated filter aid is sent to the filter aid tank. After the cleaning, a precoat liquid in which the filter aid is dispersed is supplied from a precoat tank to the filter machine to form a precoat layer on the surface of the filtering material.

Solution film-forming method

A dope containing cellulose acylate as a main content of polymer is cast on a front surface of a moving belt in a method of producing a film from a solution. A drying apparatus is confronted to a back surface of said belt to evaporate a solvent in the gel-like film. Further, a condensers are confronted to a cast surface of said gel-like film to condense a solvent vapor for recovery. A wind speed above and near the gel-like film is from 0.01 m/s to 0.5 m/s, and the belt is transported downwards at the casting position PS. When d (mm) is a distance between the casting surface and each condenser, Tw (&#xb0; C.) is a temperature of each condenser, and Ts (&#xb0; C.) is a temperature of the casting dope, conditions are satisfied: Q=(Ts&#x2212;Tw)/d and 5&#x3c;Q&#x3c;100. The obtained film is excellent in thickness uniformity and optical properties, and therefore adequate for the optical film.

Method and apparatus for producing film from polymer solution, and optical polymer film

A process for solvent casting including, casting a dope from a casting die onto a casting support, drying the cast dope on the casting support to form film, stripping off the film from the casting support, and further drying the film, wherein the dope has a solid matter content of from 17 mass % to 30 mass %, and a mean drying rate between the casting of the dope and the stripping off is more than 300 mass %/minute and not more than 1000 mass %/minute. Also, a process for solvent casting including the steps of casting a dope from a casting die to a casting support, forming the film by drying the dope to some extent, stripping off the film from the casting support and further drying the film while conveying the film with carrying it at both side edges of the film by a tenter under specified conditions.

Solvent casting process

TAC and additives are mixed in a mixture solvent of dichloromethane, methanol and n-butanol to obtain a dispersion solution. The dispersion solution is heated to become a low concentration dope whose concentration is 19.3 wt. %. The low concentration dope is fed with a pump, and supplied through a flash nozzle to a concentrating apparatus to performing flash evaporation of the solvent in the concentrating apparatus. Thus part of the solvent in the low concentration dope evaporates to obtain a condensed dope. The part of the solvent is condensed on a condensation surface to obtain a condensed solvent. The condensed solvent flows through a pipe out of the concentrating apparatus. The high concentration dope has a solid content of 22.3 wt. %, and drawn through a pump. As the solid content of the high concentration dope is high, a polymer film having the self-supporting property can be easily formed of the high concentration dope in a film production line.

Method of producing high concentration polymer solution

An low concentration dope is fed through a nozzle into a concentrating apparatus, and flash evaporation of the low concentration dope is performed at an end of the nozzle. The low concentration dope is concentrated thereby to an concentrating dope which is contained and heated in the concentrating apparatus. Thus part of solvents of the low concentration dope and the concentrating dope is evaporated to a solvent gas. The solvent gas is cooled and condensed in a condensing section of the concentrating apparatus, and thereafter drawn through a first exit from the concentrating apparatus. The concentrating dope is concentrated to a high concentration dope, which is drawn through a second exit from the concentrating apparatus.

Method for concentrating solution

An apparatus for the preparation of polymer solutions contains a stirring device, a cooling device connected to the stirring device and a warming device connected to the cooling device. Both the warming device and the cooling device are characterized by including a rotary screw. The stirring device functions to mix a polymer with a solvent to produce a swelled polymer in the solvent. The incorporation of a screw into the warming or cooling device allows the temperature of the solution to change while simultaneous mixing and shear is provided.

Apparatus containing cooling and warming devices for the preparation of a polymer solution

The present invention provides a solvent casting process which comprises casting a dope which is a solution containing at least one kind of a polymer from a casting die onto a casting support, stripping off from the casting support and drying, wherein the force necessary for stripping off the dope from the die lip end of the casting die is 40 g/cm or smaller. According to the present invention, the employment of the foregoing constitution prevents the formation of the slugs at lateral edge portions of the dope because the cast dope would not adhere to the die lip end portion of the casting die. As a result, because a breaking down of the film would not occur without washing the apparatus, an efficient production of a film having superior evenness in the flatness can be achieved.

In the transparent film of optical application or the support for photographic material produced by a solution film forming method, the polymer resin film on which any coating unevenness does not occur even when a functional layer is coated on the film surface and the manufacturing method for the film are proposed. To be concrete, a polymer resin film produced by the solution film forming method characterized by that the pitch a [cm] of the periodic thickness unevenness of web longitudinal direction and a thickness unevenness factor d [%] satisfy formula (1) described below.&#x2212;0.910.6+1.01&#x2003;&#x2003;(1) The manufacturing method using said formula is also proposed.

Polymer resin film and its production

In the transparent film of optical application or the support for photographic material produced by a solution film forming method, the polymer resin film on which any coating unevenness does not occur even when a functional layer is coated on the film surface and the manufacturing method for the film are proposed. To be concrete, a polymer resin film produced by the solution film forming method characterized by that the pitch a [cm] of the periodic thickness unevenness of web longitudinal direction and a thickness unevenness factor d [%] satisfy formula (1) described below.0.46&#x2212;0.910.6&#x2003;&#x2003;(1) The manufacturing method using said formula is also proposed.

A novel apparatus for the preparation of a polymer solution includes a stirring device, an extruder connected to the stirring device, a cooling device connected to the extruder, and a warming device connected to the cooling device. The extruder is a fiber or membrane extruding die. Both the cooling device and warming device are vessels.

A method of making cellulose polymer solution comprises dissolving a cellulose polymer raw material in a chlorine-free organic solvent system under a high temperature and a high pressure condition belonging to the nearcritical or the supercritical region of the system. By removing the solvent from the thus obtained cellulose polymer solution, cellulose polymer powders are also produced.

Method of producing cellulose polymers

A producing method of a cellulose polymer powder is provided, which comprises dissolving a cellulose polymer by exposure to an organic solvent containing, as the main component, an ester-based solvent having from 2 to 8 carbon atoms, a ketone-based solvent having from 4 to 10 carbon atoms, or an alcohol-based solvent having from 3 to 6 carbon atoms, and carbon dioxide, and then removing the carbon dioxide and the organic solvent from the solution. A producing method of an organic solvent solution of a cellulose polymer is also provided.

Producing method of cellulose polymer

A process for the preparation of a polymer solution comprises the steps of: mixing a polymer with a solvent to swell the polymer in the solvent; cooling the swelled mixture; and then warming the cooled mixture to dissolve the polymer in the solvent. The present invention uses a polymer other than cellulose esters of lower fatty acids to form the polymer solution.

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Kanagawa, Japan

Tadahiro Tsujimoto