Abstract: 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.

Abstract: A process and apparatus for solvent casting which comprises, casting a polymer solution onto a casting support, cooling the polymer solution to gelatinize on the casting support to form web, stripping off the web from the casting support, thrusting side edges of the web into pins of a pin tenter by an inserting device, and drying the web while conveying the web with carrying the side edges of the web by the pin tenter, wherein the inserting device is cooled so that the surface temperature of the web in contact with the inserting device does not exceed a gelation temperature of the polymer solution are proposed. The present invention makes surely to convey the web without slipping from the pin tenters even when the pin tenters convey the web at a high speed. As a result, the productivity of film can be improved.

Abstract: In order to produce a cellulose ester film constructed of a front layer, an intermittent layer and a rear layer, a dope solution is doped on a supporter. In at least one of the front layer and the rear layer, a mass ratio of a cotton linter to a wood pulp (cotton linter/wood pulp) is between 5/95 and 0/100, and a solvent of the dope contains more than 15 wt. % alcohols and hydrocarbons whose carbon number each is 1-10. Further, a ratio of a solid content density of a solution for forming the front layer and the rear layer to a solid density of a solution for forming the intermittent layer is less than 0.9 wt. %, and a total thickness of the solutions for front and rear layers is more than 5% of the dope ribbon.

Abstract: 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.

Abstract: A production method of cellulose film wherein cellulose film is produced by preparing a polymer solution through dissolving cellulose ester in a solvent containing a prescribed organic solvent as the main component, forming a filmy object from the prepared polymer solution, and evaporating the solvent in the filmy object; the residual amount of the organic solvent is reduced while the film quality is not degraded, and the production efficiency is degraded to a least possible extent; a poor solvent, highest in boiling point among the materials contained in the solvent, is added in the content ranging from 0.1 wt % to 1.0 wt %, taking the total amount of the solvent in the prepared polymer solution to be 100 wt %; and the solubility of cellulose ester in the poor solvent is inferior to the solubility of the cellulose ester in the organic solvent which is the main component of the solvent.

Abstract: A clip to hold the film has a clip body, a flapper, a press slider and a rail mount. A pair of the press sliders is located in both sides of the flapper. A coil spring presses the press slider upward. A pair of entrance side film release members, provided in the tenter entrance, presses the press slider downward to press the lateral edge portions of the film by the press sliders. At the film hold position, the flapper rotates from a release position to a hold position to hold the film, and the flapper is kept at the hold position by a torsion spring. The flapper holds the film 26 after the press slider holds the lateral edge portions of the film, so the flapper can hold the film even when the lateral edge portions of the film are curled.

Abstract: The mixture solvent of dichlorimethane type, the TAC and the plasticizer are supplied into a dissolution tank, and stirred therein with a stirrer to obtain a dispersing solution. The dispersing solution is fed into a storing tank and further stirred therein. Then the dispersing solution is fed by a pump to a heat exchanger for the heating, and thereafter the stirring is made with a static mixer. The temperatures of the dope is measured at many measuring points. On the basis of the temperature distribution, the heat transmission conditions of the heat exchanger are adjusted. Then the dope is fed to a heat exchanger for cooling, to cool to at most the normal boiling point of the dope. Then the mixing is made with a static mixer. Thus the obtained dope is uniform.

Abstract: An antiglare and antireflection film is provided, which can be formed by a wet-coating method and which is excellent in the antireflection property, antifouling property, scratch resistance, clearness of transmitted image and planar uniformity. A polarizer and a liquid crystal display device using this film are also provided. An antiglare and antireflection film is provided, comprising a transparent support having thereon an antiglare hard coat layer and a low refractive index layer having a refractive index of 1.38 to 1.49, wherein the low refractive index layer is formed by a coating method, the solvent of the coating solution for forming the low refractive index layer comprises one or more solvent, and from 50 to 100% by mass of the solvent is a solvent having a boiling point of 100° C. or less. A polarizer and a liquid crystal display device using this film are also provided.

Abstract: The dope prepared from a mixture solvent and solid contents such as cellulose ester and additives is cast on a drum cooled to −5° C. to form a gel-like film. The gel-like film is peeled off from the drum. Tension of 60 kg/m is applied to the gel-like film in the widthwise direction thereof and the temperature of the gel-like film is kept 120° C., when the content of the solvent to the solid contents in the gel-like film is in a range of 100 wt. % to 20 wt. %. Further the gel-like film is dried to be a cellulose ester film having 40 &mgr;m thickness. The IR spectrum of the cellulose ester film has a peak in a range of 520 cm−1 to 480 cm−1 which indicates the crystallization of the polymer. The cellulose ester film has tear strength of 12g, Rth of 42 nm and Re of 1.2 nm. As crystallization of the polymer proceeds, the cellulose ester film has sufficient strength and optical properties.

Abstract: A film is formed by casting a ribbon on a support from a flow cast die while pulling said ribbon toward said support by providing a decompression area. The decompression area is divided into a middle portion, a left portion and a right portion. Degrees of decompression in these three portions satisfy the following formulae: 0<(PC−PL)×100/|PC|<15; 0<(PC−PR)×100/|PC|<15; |PL−PR|×100/|0.5(PL+PR)|<10; wherein PC is a degree of decompression in said middle portion, PL a degree of decompression in said left portion, and PR a degree of decompression in said right portion. The film obtained by the above method is suitable for a polarizing plate protection film, which is used for a liquid crystal display device.

Abstract: A solution casting process for producing cellulose triacetate (TAC) film is provided. Bead of dope, which includes cellulose triacetate and solvent, is cast on to a rotating supporting drum, to form self-supporting cast film. The self-supporting cast film is stripped from the supporting drum. The self-supporting cast film is dried while the self-supporting cast film being stripped is fed by feed rollers, to form the cellulose triacetate film. A surface temperature of the feed rollers is set equal to or lower than 0° C. The self-supporting cast film upon being stripped has modulus of longitudinal elasticity equal to or more than 450,000 Pa.

Abstract: The dope prepared from a mixture solvent and solid contents such as cellulose ester and additives is cast on a drum cooled to −5° C. to form a gel-like film. The gel-like film is peeled off from the drum. Tension of 60 kg/m is applied to the gel-like film in the widthwise direction thereof and the temperature of the gel-like film is kept 120° C., when the content of the solvent to the solid contents in the gel-like film is in a range of 100 wt. % to 20 wt. %. Further the gel-like film is dried to be a cellulose ester film having 40 &mgr;m thickness. The IR spectrum of the cellulose ester film has a peak in a range of 520 cm−1 to 480 cm−1 which indicates the crystallization of the polymer. The cellulose ester film has tear strength of 12 g, Rth of 42 nm and Re of 1.2 nm. As crystallization of the polymer proceeds, the cellulose ester film has sufficient strength and optical properties.

Abstract: Cellulose triacetate film is produced by a solution casting process. Dope, which includes cellulose triacetate and mixed solvent with methyl acetate, is cast on a rotary drum in a form of bead by use of a flow casting die, to form gel film. When a self-supporting characteristic of the gel film becomes higher than one limit value, the gel film is stripped from the rotary drum by use of a stripping roller, to obtain the cellulose triacetate film. During the casting step, a surface of the rotary drum is cooled at −10° C. or lower.

Abstract: 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.

Abstract: A solution film-forming method including the steps of forming a film from a polymer solution in which a polymer is dissolved in an organic solvent transporting the film formed and passing the film through a drying area in which the film is heated to volatilize the organic solvent in the film to obtain a polymer film, wherein the film is passed through the drying area under the condition of −0.05≦&egr;MD-&egr;TD<+0.15, where a degree of stretching of the film in the transport direction within the drying area during transport is expressed as &egr;MD and a degree of stretching of the film in the width direction within the drying area during transport is expressed as &egr;TD.

Abstract: A production method of cellulose film wherein cellulose film is produced by preparing a polymer solution through dissolving cellulose ester in a solvent containing a prescribed organic solvent as the main component, forming a filmy object from the prepared polymer solution, and evaporating the solvent in the filmy object; the residual amount of the organic solvent is reduced while the film quality is not degraded, and the production efficiency is degraded to a least possible extent; a poor solvent, highest in boiling point among the materials contained in the solvent, is added in the content ranging from 0.1 wt % to 1.0 wt %, taking the total amount of the solvent in the prepared polymer solution to be 100 wt %; and the solubility of cellulose ester in the poor solvent is inferior to the solubility of the cellulose ester in the organic solvent which is the main component of the solvent.

Abstract: A solution film-forming method for obtaining the polymer film includes discharging a pressurized polymer solution having a specific temperature from a casting die, casting the polymer solution on a support, solidifying the polymer solution to form a film, peeling and drying the film, wherein the polymer solution to be cast on the support is mixed with a specific solvent such that E1/n is larger than 0.1 (l/second) and smaller than 3.0 (l/second) when the dynamic modulus of rigidity and dynamic coefficient of viscosity of the polymer solution immediately after discharged on the support from the casting die are E1 (Pascal) and n (Pascal·second), respectively.

Abstract: An antiglare and antireflection film is provided, which can be formed by a wet-coating method and which is excellent in the antireflection property, antifouling property, scratch resistance, clearness of transmitted image and planar uniformity. A polarizer and a liquid crystal display device using this film are also provided.

Abstract: A process and apparatus for solvent casting which comprises, casting a polymer solution onto a casting support, cooling the polymer solution to gelatinize on the casting support to form web, stripping off the web from the casting support, thrusting side edges of the web into pins of a pin tenter by an inserting device, and drying the web while conveying the web with carrying the side edges of the web by the pin tenter, wherein the inserting device is cooled so that the surface temperature of the web in contact with the inserting device does not exceed a gelation temperature of the polymer solution are proposed. The present invention makes surely to convey the web without slipping from the pin tenters even when the pin tenters convey the web at a high speed. As a result, the productivity of film can be improved.

Abstract: In order to produce a cellulose ester film constructed of a front layer, an intermittent layer and a rear layer, a dope solution is doped on a supporter. In at least one of the front layer and the rear layer, a mass ratio of a cotton linter to a wood pulp (cotton linter/wood pulp) is between 5/95 and 0/100, and a solvent of the dope contains more than 15 wt. % alcohols and hydrocarbons whose carbon number each is 1-10. Further, a ratio of a solid content density of a solution for forming the front layer and the rear layer to a solid density of a solution for forming the intermittent layer is less than 0.9 wt. %, and a total thickness of the solutions for front and rear layers is more than 5% of the dope ribbon.