JP4542833B2 - Dope manufacturing apparatus, manufacturing method, solution casting method, and product - Google Patents

Description

  The present invention relates to a dope manufacturing apparatus, a dope manufacturing method, a solution film forming method, a film obtained by using the film forming method, and a product using the film.

  High molecular compounds (hereinafter referred to as polymers) are used in various fields, and products are produced by various production methods depending on the application. For example, a film such as a plastic film is formed by a melt film forming method in which a polymer is heated to a molten state, or a liquid (hereinafter referred to as a dope) prepared by dissolving or dispersing a polymer in a solvent is formed. There is a solution casting method. In the solution casting method, after casting a dope, the solvent is volatilized to produce a film. As the solvent used in this case, the most appropriate solvent is selected in consideration of various points such as the solubility of the polymer, the volatility and the influence on the human body and the environment. Particularly in recent years, safety has been strongly demanded for the human body and the environment. For this reason, it is difficult to select a solvent when preparing a dope depending on the type of polymer.

  For example, when producing a cellulose acetate film (hereinafter also referred to as TAC in combination with cellulose triacetate) film often used as a photographic film base, a solution casting method using methylene chloride (methylene chloride, dichloromethane) as a main solvent is used. It is manufactured (for example, refer nonpatent literature 1). However, the use of methylene chloride is greatly restricted due to problems with the human body and the environment. Thus, although there is a method using acetone, which has a smaller problem for the human body and the environment than other solvents, there arises a problem that TAC is difficult to dissolve.

  Then, the cooling apparatus using a screw type mixer (screw extruder) is proposed as a manufacturing method of dope required for the solution casting method (for example, refer nonpatent literature 2). According to this method, cellulose acetate (TAC) having a substitution degree of 2.80 (acetylation degree of 60.1%) to a substitution degree of 2.90 (acetylation degree of 61.3%) in acetone is -80 ° C to- By heating after cooling to 70 ° C., a solution in which 0.5% to 5% by weight of TAC is dissolved in acetone is obtained. Hereinafter, a method for preparing a dope by cooling a solvent containing a polymer is referred to as a “cooling dissolution method”. In addition, a method in which the cooling dissolution method is applied to a spinning method technique is also known. In this method, the cooling dissolution method is studied while paying attention to the mechanical properties, dyeability, and fiber cross-sectional shape of the obtained fiber, and a dope having a concentration of 10 wt% to 25 wt% is obtained (for example, non-dose). (See Patent Document 3). In the cooling dissolution method, a dope can be continuously produced by using a dope production apparatus in which an extruder equipped with a screw is cooled to a low temperature.

Japan Society for Invention and Innovation Public Technical Bulletin No. 2001-1745 (page 2-3) J. et al. M.M. G. Cowie et al., “Makromol, Chem.”, 1971, 143, 105. Kenji Kamide et al., “Dry spinning from cellulose triacetate in acetone solution”, Textile Society of Japan, (1981), 34, 57-61.

  However, as is generally understood from the fact that the screw is used as a heating source for melt film formation, heat is generated when the screw is rotated. Therefore, if the screw in the dope manufacturing apparatus cooled to low temperature is rotated and a solvent, a polymer, etc. are sent, it will become difficult to control cooling conditions appropriately. In addition, it is said that it is better to lower the temperature for cooling and melting. However, when the temperature is lowered, when the polymer and the solvent are fed, the viscosity increases, so the resistance to the screw is large and heat is generated. It becomes easy to do. Therefore, it becomes more difficult to carry out liquid feeding while maintaining the cooling temperature. Furthermore, if the rotational speed of the screw is increased to increase productivity, the heat generation becomes more intense and the solubility decreases. Therefore, in order to avoid this, it is necessary to lower the liquid feeding speed, but naturally the productivity is lowered. In addition to this, a large amount of energy is required for cooling, which is a great loss in terms of energy and cost. In addition, when the polymer concentration is increased, the decrease in the flow rate of the liquid appears remarkably, and in some cases, the liquid cannot be fed at a certain concentration or higher. For this reason, a method for improving dissolution capacity and increasing production capacity has been desired.

  The present invention relates to a dope manufacturing apparatus for improving dope productivity, a dope manufacturing method, a solution film forming method using the dope method, a film manufactured by the solution film forming method, and a product such as a protective film using the film. The purpose is to provide.

  Another object of the present invention is to provide an apparatus for producing a dope that improves the productivity of the dope and reduces the amount of energy used.

  As a result of intensive studies, the present inventor has found that the above problems can be solved by using the means described below.

  By using a compression type screw in the screw extruder, the solubility of the dope is improved due to the kneading effect in the extruder and the cooling effect increase due to the decrease in the amount of heat generated due to the decrease in the rotational speed. In addition, a compression type screw means the screw from which the pressure of a measurement part becomes higher than a supply part.

  It was found that when the dope is produced by the cooling dissolution method, the solubility depends not only on the temperature but also on the cooling time. The solubility may not reach the target only by the cooling time in the extruder (dope raw material or dope residence time). In such a case, by installing a cooling unit that holds the cooling at the outlet side of the extruder. It has also been found that the cooling time can be applied in addition to staying in the extruder, and the solubility of the polymer is improved. By using such means, the solubility of the polymer in the solvent can be improved, and the productivity of the dope by the cooling dissolution method can be improved. Moreover, the productivity of film manufacture can also be improved with the improvement of dope productivity. In addition, even if the productivity of the dope with such improved productivity is improved, the physical properties are good, so the optical properties of the film formed from the dope and various optical products using the film There is no particular deterioration, and as a result, the productivity of various optical products can be improved.

  The dope manufacturing apparatus of the present invention is a dope manufacturing apparatus that manufactures a dope by cooling a dope raw material using an extruder equipped with a screw, and the shape of the screw is a compression type. It is preferable that the screw provided in the extruder is uniaxial or biaxial. It is more preferable from the viewpoint of improving solubility that the extruder used in the present invention is equipped with a twin screw. Furthermore, kneading is improved by making the screw biaxial, and solubility is improved by reducing the temperature difference between the vicinity of the wall surface at the extrusion outlet and the central portion. The temperature difference between the vicinity of the wall surface at the extrusion outlet and the central portion is preferably within 5 ° C, more preferably within 1 ° C. Further, although the cost is high, a screw having three or more axes can be used. In the present invention, the form of the twin screw is not particularly limited. For example, any of a non-meshing type and a meshing type (for example, a partial meshing type, a full meshing type, etc.) can be used. The rotation direction of the biaxial screw may be either the same direction rotation or the different direction rotation.

The dope manufacturing apparatus of the present invention has an extruder equipped with a screw including a screw shaft and a spiral blade in a cylinder, and in the dope manufacturing apparatus for manufacturing a dope by cooling a dope raw material, the screw shaft includes: A first screw shaft portion having a first diameter on the dosing material input side, a second screw shaft portion having a second diameter larger than the first diameter on the dope extrusion side, and the first screw shaft portion; And a third screw shaft portion that connects the second screw shaft portion, and a gap between the cylinder and the third screw shaft portion becomes narrower along a liquid feeding direction of the dope. The screw is preferably a single screw or a twin screw. It is preferable that the third screw shaft portion compresses the dope raw material. The length A (mm) of the first screw shaft portion, the length B (mm) of the third screw shaft portion, and the length C (mm) of the second screw shaft portion are A ≦ B and C ≦ B is preferable. The length A (mm) of the first screw shaft portion, the length B (mm) of the third screw shaft portion, and the length C (mm) of the second screw shaft portion are 1.1 ≦ ( B / A) ≦ 4 and 1.1 ≦ (B / C) ≦ 4 are preferable. In the present invention, the starting point of the length A of the first screw shaft portion is the most upstream side of the portion where the dope material is introduced.

It is preferable to compress the dope material or dope in a range of more than 1.0 times and not more than 5 times. It is preferable that a gap between the shaft of the second screw shaft portion and the cylinder is 1.5 mm or more and 6 mm or less. It is preferable that a jacket is provided on the outer peripheral portion of the cylinder of the extruder, and the jacket is divided into two or more sections. The length L (mm) of the lead portion of the extruder and the cylinder inner diameter D (mm),
A range of 5 <(L / D) <50 is preferable.

  The dope manufacturing apparatus of the present invention includes an extruder that cools a dope raw material and rotates a screw to manufacture a dope, and a cooling unit on the downstream side of the extruder. It is preferable to provide a cooling unit on the downstream side of the extruder. The cooling unit is preferably another screw extruder. In addition, it is preferable to use a single screw extruder for the other screw extruder. It is preferable that the cooling unit is a double pipe type pipe, and an outer pipe line of the pipe is a refrigerant liquid passage. More preferably, a refrigerant circulator is attached to the outer conduit. It is preferable that the cooling unit is a double pipe type pipe and has a vacuum heat insulating pipe structure.

The ratio of the first volume V1 through which the dope or dope raw material passes through the extruder and the second volume V2 through which the dope flows through the cooling section is in a range of 0.5 ≦ (V2 / V1) ≦ 100. It is preferable that It is preferable that the cylinder inner diameter D (mm) of the extruder and the inner diameter D2 (mm) of the inner pipe of the double pipe type pipe are in a range of 0.8 <(D2 / D) <10. It is preferable to install a heater on the downstream side of the cooling unit.

  The dope manufacturing method using the said dope manufacturing apparatus is also contained in this invention. In addition, a single screw extruder can be used for the extruder.

  The dope production method of the present invention is a dope production method in which a dope is produced by cooling a raw material containing a polymer and a solvent, and the dope is produced by using an extruder equipped with a screw having a shape for compressing the dope raw material or the dope. Manufacturing. It is preferable to use a single screw screw provided in the extruder. It is more preferable from the point of improvement in solubility that the extruder used in the present invention is provided with a biaxial screw. It is preferable that the dope temperature TD at the outlet of the extruder is set to −30 ° C. or lower. It is preferable to cool the dope raw material or the dope in the extruder at a cooling rate of 5 ° C./min to 200 ° C./min.

  It is preferable to cool the dope prepared in the extruder within 60 minutes. It is preferable that the dope is cooled using a double-pipe pipe provided on the downstream side of the extruder. It is preferable to use at least one of methanol, hydrofluoroether, and brine as the refrigerant sent to the outer pipe of the double pipe type pipe. Examples of hydrofluoroethers include, but are not limited to, HFE7100 (trade name), HFE7200 (trade name), and the like.

A jacket divided into two or more sections is provided on the outer periphery of the cylinder of the extruder, and the cylinder inlet temperature T1 (° C.) on the side where the dope raw material is charged and the cylinder outlet temperature T2 on the side where the dope is fed out (℃)
It is preferable to cool as T2 <T1. It is preferable to cool by setting the temperature T (° C.) of the cooling section and the cylinder outlet temperature T2 (° C.) as T ≦ T2, more preferably T ≦ 0.95 × T2. After cooling the dope, it is preferable to heat the dope at a heating rate of 20 ° C./min or more. In addition, a single screw extruder can be used for the extruder.

  The polymer is preferably cellulose acylate, more preferably cellulose acetate, and most preferably cellulose triacetate. It is preferable that the solvent contains at least methyl acetate.

  A solution casting method using the dope produced by the dope producing method is also included in the present invention. A solution casting method in which the dope produced by the dope producing method is used to form a film by any one of a co-casting method, a sequential casting method, and a sequential co-casting method is also included in the present invention.

  A film formed by the solution casting method and a protective film formed using the film are also included in the present invention. The present invention also includes a polarizing plate constituted by using a film formed by the solution casting method and a liquid crystal display device constituted by using the polarizing plate. The present invention also includes an optical compensation film configured using a film formed by the solution casting method and a liquid crystal display device configured using the optical compensation film. A photographic light-sensitive material constituted using a film formed by the solution casting method is also included in the present invention.

  According to the dope producing apparatus of the present invention, in the dope producing apparatus for producing a dope by cooling the dope raw material using an extruder equipped with a screw, the screw has a compression shape, so that the solvent is dissolved. As a result, the polymer can be easily dissolved and the productivity of the dope is improved. When the extruder equipped with a biaxial screw is used, the dope raw material is further kneaded and the solubility of the dope is further improved.

  According to the dope producing apparatus of the present invention, the dope producing apparatus for producing a dope by cooling a dope raw material having an extruder including a screw including a screw shaft and a spiral blade in a cylinder, the screw shaft includes: A first screw shaft portion having a first diameter on the dosing material input side, a second screw shaft portion having a second diameter larger than the first diameter on the dope extrusion side, and the first screw shaft. A gap between the cylinder and the third screw shaft portion including the third screw shaft portion connecting the portion and the second screw shaft portion becomes narrow along the liquid feeding direction of the dope. By compressing the raw material, a solute such as a polymer is easily dissolved in the solvent, and the productivity of the dope is improved.

  Since the dope material or dope is compressed in the range of more than 1.0 times and not more than 5 times, the polymer and the like are easily dissolved in the solvent, and the productivity of the dope can be increased.

  According to the dope manufacturing apparatus of the present invention, since the dope is cooled and the screw is rotated to manufacture the dope, and the cooling unit is provided on the downstream side of the extruder, the heat generated by the rotation of the screw is provided. As a result, it is possible to minimize the number of cooling points that suppress the above, maintain the productivity of the dope, and reduce the energy used.

  By attaching at least one of a cooling unit or another extruder on the downstream side of the extruder, a solute such as a polymer is more easily dissolved in the solvent in the cooling unit or the other extruder, and the dope productivity is increased. Can be further increased.

  The cooling part is a double-pipe type pipe, and the outer pipe line of the pipe is used as a refrigerant passage pipe, and the cooling part is prepared by passing the refrigerant and cooling the cooling part to an appropriate temperature. In addition to ensuring the solubility of the dope, the dissolution can be further advanced. In addition, since the cooling unit is a double pipe type pipe, the manufacturing cost can be reduced.

  The ratio of the first volume V1 through which the dope or dope raw material passes through the extruder and the second volume V2 through which the dope flows through the cooling section is in the range of 0.5 ≦ (V2 / V1) ≦ 100. Then, when the dope prepared in the extruder is cooled in the cooling section, the cooling time can be lengthened, and the effect of improving the solubility by the cooling section is easily exhibited.

  Since the cylinder inner diameter D (mm) of the extruder and the inner diameter D2 (mm) of the inner pipe of the double pipe type pipe are in the range of 0.8 <(D2 / D) <10, And the pressure difference between the cooling part and the dope due to the pressure difference can be suppressed.

  When a heater is attached to the downstream side of the cooler and the dope raw material or the dope is fed successively in the order of the extruder, the cooling unit, and the heater, the solubility is most improved.

  According to the dope production method of the present invention, in the dope production method for producing a dope by cooling a raw material containing a polymer and a solvent, an extruder equipped with a screw shaped to compress the dope raw material or the dope is used. Since the dope is manufactured, the polymer is easily dissolved in a solvent, and the productivity of the dope is increased.

  Since the dope raw material or dope in the extruder is cooled at a cooling rate of 5 ° C./min or more and 200 ° C./min or less, a temperature at which a polymer or the like is easily dissolved in a solvent can be quickly reached, and the dope productivity is improved. .

  Since the dope prepared in the extruder is cooled within 60 minutes, a polymer or the like dissolves in the solvent during the cooling, and a high concentration dope can be produced.

  At least one of methanol, hydrofluoroether, and brine is used as a refrigerant to be sent to the outer pipe of the double pipe type pipe using a double pipe type pipe provided with cooling of the dope on the downstream side of the extruder. And the refrigerant is circulated by a refrigerant circulator, so that the amount of refrigerant used can be reduced, the cost can be reduced, and the release of the refrigerant compound to the environment is suppressed, and the dope manufacturing method excellent in environmental protection It is.

  Using a jacket divided into two or more sections on the outer periphery of the cylinder of the extruder, a cylinder inlet temperature T1 (° C.) on the side where the dope raw material is charged and a cylinder outlet temperature T2 on the side where the dope is fed out Since (C) is cooled as T2 <T1, the dope raw material can be easily fed in the extruder, and at a temperature at which the polymer is dissolved in the solvent.

  Since the temperature T (° C.) of the cooling section and the cylinder outlet temperature T2 (° C.) are cooled as T ≦ 0.95 × T2, the cooling of the dope solute prepared in the extruder is suppressed. Further cooling with a machine makes it easy to dissolve a polymer or the like in a solvent, and a high concentration dope can be produced.

  When the dope is heated at a heating rate of 20 ° C./min or higher after the dope is cooled, a solute such as a polymer is easily dissolved in a solvent, and a high concentration dope can be manufactured.

  Since the polymer is cellulose acylate, the dope can be preferably used as a dope for solution casting. Moreover, even if the said solvent contains at least methyl acetate, the dope which used the methyl acetate whose polymer solubility is inferior as a main solvent can be manufactured easily. A film can be formed by the solution casting method using the dope. Since the film was formed into a solution using a dope having excellent solubility, a film having excellent optical properties can be obtained. Since the film is excellent in optical properties, it can be preferably used as a member such as a protective film, a polarizing plate, a liquid crystal display device, an optical compensation film, and a photographic photosensitive material.

[solvent]
Any known solvent can be used for the present invention. It is particularly preferable to use a polymer whose later-described polymer swells with a solvent in a temperature range of 0 ° C to 55 ° C. In addition, the said temperature range is a temperature range at the time of using the manufactured dope at the time of film forming. Further, by selecting a polymer that swells in a solvent in the above temperature range and using the dope production method of the present invention, there is an effect that the time for producing a dope by stirring at a normal temperature or high temperature can be shortened. In this case, the solvent may be a mixed solvent.

  The solvent used is preferably an organic solvent rather than an inorganic solvent. Specific examples of the organic solvent include esters (eg, methyl formate, methyl acetate, ethyl acetate, amyl acetate, butyl acetate, etc.), ethers (eg, dioxane, dioxolane, THF, diethyl ether, methyl-t-butyl ether, etc.). ), Aromatic hydrocarbons (eg, benzene, toluene, xylene, etc.), aliphatic hydrocarbons (eg, hexane, heptane, etc.), alcohols (eg, methanol, ethanol, n-butanol, etc.), ketones ( For example, cyclopentanone, acetone, methyl ethyl ketone, cyclohexanone, etc.). Moreover, the mixed solvent which mixed these can also be used.

  In the present invention, it is preferable to select the most appropriate solvent according to the type of polymer described below. For example, when the polymer is cellulose triacetate (TAC), polycarbonates, and polystyrenes, it is preferable to use acetone or methyl acetate. In this case, acetone and methyl acetate may be used alone (100% by weight), or a mixed solvent obtained by mixing other solvents may be used. Moreover, when using a mixed solvent, it is most preferable that acetone and methyl acetate are main solvents (50 weight% or more). Further, when a norbornene-based polymer is used as the polymer, it is preferable to use aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane, and ketones such as acetone and methyl ethyl ketone. In the case of polymethyl methacrylate (PMMA), it is preferable to use ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and butyl acetate, and alcohols such as methanol. In these cases, a mixed solvent in which two or more kinds of solvents are mixed can also be used. Moreover, the dope manufacturing method of this invention can also use the mixed solvent of halogenated hydrocarbons, such as a dichloromethane, and halogenated hydrocarbons, and a well-known solvent.

[polymer]
The polymer used in the present invention is not particularly limited. Specifically, polyamides, polyolefins, norbornenes, polystyrenes, polycarbonates, polysulfones, polyacrylic acids, polymethacrylic acids, polyether ether ketone (PEEK; Polyetheretherketone), polyvinyl alcohols, polyvinyl acetates, and cellulose derivatives (for example, lower fatty acid ester of cellulose, cellulose acylate, etc.).

  Preferably, cellulose acylate, which is a cellulose derivative, is used. A particularly preferred lower fatty acid ester of cellulose will be described. Lower fatty acid means a fatty acid having 6 or less carbon atoms. The number of carbon atoms is preferably 2 (cellulose acetate), 3 (cellulose propionate), 4 (cellulose butyrate). In the present invention, it is preferable to use cellulose acetate. Furthermore, among cellulose acetates, it is most preferable to use cellulose triacetate having an acetylation degree of 59.0% to 62.5%. Cellulose triacetate includes cotton linters and wood pulp. The cellulose triacetate may be made from cotton linters, wood pulp, or a mixture of both.

  When TAC is used for the polymer, it is preferable to use a mixed solvent containing methyl acetate as a main solvent from the viewpoint of the environment. In this case, the composition ratio of methyl acetate in the mixed solvent is preferably 60% by weight or more, and more preferably 70% by weight or more. It is also possible to use only methyl acetate (100% by weight). In addition, it is most preferable to use a mixed solvent in which methyl acetate is mixed with another solvent because the physical properties of the dope can be controlled. As other solvents, alcohols such as methanol and ethanol, and ketones such as cyclopentanone and acetone are preferably used.

[Additive]
Any known additive can be used for the dope according to the present invention. For example, plasticizer (triphenyl phosphate (hereinafter referred to as TPP), biphenyl diphenyl phosphate, dipentaerythritol hexaacetate, etc.), ultraviolet absorber (eg, oxybenzophenone compound, benzotriazole compound, etc.), matting agent (For example, silicon dioxide etc.), a thickener, an oil gelling agent, etc. are mentioned, However, It is not limited to these. These additives may be added when a dope is prepared using a cooling dissolution method, or when a film is formed by a solution casting method using a dope prepared from a polymer and a solvent. May be.

  The additive used in the present invention will be further described. For example, a plasticizer, an anti-degradation agent, an ultraviolet absorber, an optical anisotropy control agent (retardation control agent), a dye, a pigment, fine particles (matting agent), a release agent, etc. are added to the dope according to the present invention. Can do. Further, the addition may be performed at any time during the dope preparation process. For example, there is a method of adding a step of adding an additive to the final preparation step of the dope preparation step.

(Plasticizer)
Although the plasticizer used for this invention is not specifically limited, Phosphate ester or carboxylic acid ester is used preferably. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate. Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetyl citrate (OACTE) and tributyl O-acetyl citrate (OACTB), acetyl triethyl citrate, and acetyl tributyl citrate. These preferred plasticizers are liquid except for TPP (melting point: about 50 ° C.) at 25 ° C. and have a boiling point of 250 ° C. or higher. These plasticizers may be used alone or in combination of two or more. The addition amount of the plasticizer is preferably 2% by mass to 30% by mass, particularly preferably 5% by mass to 20% by mass with respect to the cellulose acylate. The plasticizer is described in detail in paragraphs [0194] to [0203] of Japanese Patent Application No. 2003-319673, and the above description can be preferably applied to the present invention.

(Deterioration inhibitor)
As the deterioration preventing agent, for example, a basic compound having a pKa of 4 or more described in JP-A-5-194789 is preferably exemplified. Specific examples include tributylamine, trihexylamine, trioctylamine, dodecyl-dibutylamine, octadecyl-dimethylamine, tribenzylamine, and diethylaminobenzene. The deterioration preventing agent is described in detail in paragraphs [0204] to [0214] of Japanese Patent Application No. 2003-319673, and the above description can be preferably applied to the present invention.

(UV absorber)
Although the ultraviolet absorber preferably used in the present invention is not particularly limited, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc.

  Specific examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl). ) Benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl)- 5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2-methylenebis ( 4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2′-hydroxy-3′-tert) -Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis ( 2-methoxy-4-hydroxy-5-benzoylphenylmethane), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3, 5-triazine, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2′-hydroxy-3 ′, 5′-di-tert-amyl) Phenyl) -5-chlorobenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- 3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexane Diol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di- tert-butylanilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3 5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert- Til-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di) -Tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. In particular, (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, 2 (2′-hydroxy-3 ′, 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) -5-chlorobenzotriazole, 2,6-di -Tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl -5-methyl-4-hydroxyphenyl) propionate], for example, N, N'-bis [3- (3,5-di-tert-butyl-4-hydroxy). A hydrazine-based metal deactivator such as (cyphenyl) propionyl] hydrazine or a phosphorus-based processing stabilizer such as tris (2,4-di-tert-butylphenyl) phosphite may be used in combination. Is preferably 1 ppm to 1.0% by weight, and more preferably 10 ppm to 1000 ppm, with respect to the cellulose acylate, and the ultraviolet absorber is described in paragraphs [0204] to [0223] of Japanese Patent Application No. 2003-319673. It is described in detail, and the above description can be preferably applied to the present invention.

(Optical anisotropy control agent)
A retardation control agent for controlling optical anisotropy is optionally added to the dope. The retardation control agent is not particularly limited, but is a compound having at least two aromatic rings, which are connected by a linking group, and a molecular structure that does not sterically hinder the conformation of the two aromatic rings. Is mentioned. In the present invention, the aromatic ring includes an aromatic heterocycle. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring. As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable.

  The aromatic ring and the linking group may have a substituent. However, the substituent is required not to sterically hinder the conformation of the two aromatic rings. In steric hindrance, the type and position of substituents are problematic. As the type of the substituent, a sterically bulky substituent (for example, a tertiary alkyl group) tends to cause steric hindrance. As the position of the substituent, steric hindrance is likely to occur when a position adjacent to the bond of the aromatic ring (ortho position in the case of a benzene ring) is substituted. Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, nitro, sulfo, carbamoyl, sulfamoyl, ureido, alkyl group, alkenyl group, alkynyl group, aliphatic acyl group , Aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group, aliphatic substituted carbamoyl group, aliphatic Substituted sulfamoyl groups, aliphatic substituted ureido groups and non-aromatic heterocyclic groups are included. The molecular weight of the retardation control agent is preferably 300 to 800. The boiling point of the retardation control agent is preferably 260 ° C. or higher. The boiling point can be measured using a commercially available measuring device (for example, TG / DTA100, manufactured by Seiko Electronics Industry Co., Ltd.).

A rod-shaped compound having at least two aromatic rings can also be used as a retardation control agent. The rod-shaped compound preferably has a linear molecular structure. As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (I) is preferable.
General formula (I): Ar1-L1-Ar2
In the general formula (I), Ar1 and Ar2 are each independently an aromatic group. In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group. An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group.

  In the general formula (I), L1 is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof. The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group. The alkylene group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, more preferably 1 to 10, still more preferably 1 to 8, and most preferably 1 to 6 carbon atoms. It is.

  Other retardation control agents include compounds having a triphenylene ring. The molecular weight of the compound having a triphenylene ring is preferably 300 to 2,000. The boiling point of the compound is preferably 260 ° C. or higher. The boiling point can be measured using a commercially available measuring device (for example, TG / DTA100, manufactured by Seiko Electronics Industry Co., Ltd.). You may use together the compound which has a 2 or more types of triphenylene ring as a retardation control agent.

  As other retardation control agents, a discotic compound may also be mentioned. As the discotic compound, a compound having a 1,3,5-triazine ring or a compound having a porphyrin skeleton can be preferably used. The molecular weight of the compound having a 1,3,5-triazine ring is preferably 300 to 2,000. The boiling point of the compound is preferably 260 ° C. or higher. The boiling point can be measured using a commercially available measuring device (for example, TG / DTA100, manufactured by Seiko Electronics Industry Co., Ltd.). A melamine polymer may be used as the compound having a 1,3,5-triazine ring. The melamine polymer is preferably synthesized by a polymerization reaction between a melamine compound and a carbonyl compound. A copolymer combining two or more kinds of repeating units may be used. Two or more homopolymers or copolymers may be used in combination. Two or more kinds of compounds having 1,3,5-triazine ring may be used in combination. Two or more kinds of discotic compounds (for example, a compound having a 1,3,5-triazine ring and a compound having a porphyrin skeleton) may be used in combination. The optical anisotropy control agent (retardation control agent) is described in detail in paragraphs [0224] to [0446] of Japanese Patent Application No. 2003-319673, and the above description is preferably applied to the present invention. be able to.

(dye)
In the present invention, a dye for adjusting the hue may be added. The content of the dye is preferably 10 ppm to 1000 ppm, more preferably 50 ppm to 500 ppm in terms of a mass ratio with respect to cellulose acylate. By containing the dye in this way, light piping of the cellulose acylate film can be reduced, and yellowness can be improved. These compounds may be added together with cellulose acylate and a solvent during the preparation of the cellulose acylate solution, or may be added during or after the solution preparation. Moreover, you may add to the ultraviolet absorber liquid added in-line.

JP-B Nos. 45-15187, 51-25335, 51-33724, 55-19933, M.C. Matsuoka, M. Kisimomoto, tea. Kitao, Journal of the Society of Dyers and Colorists, 94, 435, 1978 (M. Matsuoka, M. Kishimoto, T. Kitao, J. Soc. Dyers and Colourists, 94, 435 (1978)) It can be synthesized by the method described in “Dye Chemistry”, pages 673 to 741, Gihodo (1957). The amount of the dye is preferably ^{0.001g / m 2 ~1g / m 2} , 0.005g / m 2 ~0.5g / m 2 is more preferable. These dyes may be used alone or in combination. The amount of dye used is preferably 0.005 to 0.5 in terms of increase in transmission density, more preferably 0.01 to 0.3, and even more preferably 0.01 to 0.1. It is preferable to do this. The dyes are described in detail in paragraphs [0447] to [0465] of Japanese Patent Application No. 2003-319673, and the above description can be preferably applied to the present invention.

(Pigment)
A pigment can also be used in the present invention. The pigment used is not particularly limited, but carbon black, alkali metal, alkaline earth metal, Si, Al, Ti, Fe oxides, sulfides, sulfates, sulfites, carbonates, Examples include hydroxides, halides, and nitrates. Carbon black, titanium dioxide and the like are preferable. The amount of the pigment used is preferably 0.005 to 0.5 in terms of increase in transmission density, more preferably 0.01 to 0.3, and still more preferably 0.01 to 0.1. A pigment and a dye may be used in combination, but the total addition amount is preferably in the above range. In this manner, light piping can be prevented by adding a dye and / or a pigment to the dope.

(Fine particles)
In addition, various additives may be further added to the cellulose acylate solution of the present invention as necessary at any stage after preparation of the solution. As additives, fine particles (inorganic fine particles) such as silicon dioxide, kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, alumina, etc., and the fine particles used (inorganic fine particles) serve as anti-smudge agents. And antistatic. In that case, the hardness of the metal or metal compound is not particularly limited, but the Mohs hardness is preferably 1 to 10, more preferably 2 to 10. Organic fine particles are also preferably used, and examples thereof include crosslinked polystyrene, crosslinked polymethyl methacrylate, and crosslinked triazine resin.

  In particular, in the present invention, when the produced cellulose acylate film is handled, it is generally performed to add fine particles in order to prevent damage and deterioration of transportability. They are called matting agents, anti-blocking agents or anti-scratching agents and have been used conventionally. They are not particularly limited as long as they are materials exhibiting the above-mentioned functions, but preferred specific examples of these matting agents include inorganic compounds such as compounds containing silicon, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, and oxidation. Barium, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin / antimony oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate Etc., more preferably an inorganic compound containing silicon or zirconium oxide, but since the turbidity of the cellulose acylate film can be reduced, silicon dioxide is particularly preferably used.

  As the organic compound, for example, polymers such as silicone resin, fluorine resin and acrylic resin are preferable, and among them, silicone resin is preferably used. Among silicone resins, those having a three-dimensional network structure are particularly preferable. The fine particles (mat agent) are described in detail in paragraphs [0467] to [0487] of Japanese Patent Application No. 2003-319673, and the above description can be preferably applied to the present invention.

(paint remover)
Furthermore, in the present invention, it is preferable to add a release agent in order to reduce the load at the time of peeling. Of these, surfactants are effective, and phosphoric acid type, sulfonic acid type, carboxylic acid type, nonionic type, cationic type and the like are not particularly limited. These are described in, for example, JP-A-61-243837 and JP-A-2000-99847. The release agent is described in detail in paragraphs [0488] to [0506] of Japanese Patent Application No. 2003-319673, and the above description can be preferably applied to the present invention.

(Other)
Thermal stabilizers such as alkaline earth metal salts such as calcium and magnesium, antistatic agents, flame retardants, lubricants, oils and the like can be added to the cellulose acylate solution.

[Dope production method]
(Swelling process)
In the swelling step, the polymer compound and the solvent are mixed and the polymer compound is swollen with the solvent. It is preferable that the temperature of a swelling process is -10 degreeC-55 degreeC, and it implements normally at room temperature. The ratio between the polymer compound and the solvent is determined according to the concentration of the solution finally obtained. Generally, the amount of the polymer compound in the swelling step is preferably 5% to 30% by weight of the solution to be prepared, more preferably 8% to 20% by weight, and 10% to 15% by weight. Most preferably. The swelling mixture of the solvent and the polymer compound is preferably stirred until the polymer compound is sufficiently swollen. The stirring time is preferably 10 minutes to 150 minutes, and more preferably 20 minutes to 120 minutes. In the swelling step, components other than the solvent and the polymer compound, for example, additives such as a plasticizer, a deterioration inhibitor, and an ultraviolet absorber may be added.

(Dope production equipment)
FIG. 1 shows a schematic view of a dope manufacturing apparatus 10 used in the dope manufacturing method of the present invention, FIG. 2 shows a cross-sectional view of the main part thereof, and FIG. 3 shows a schematic diagram for explaining the main part thereof. The dope manufacturing apparatus 10 includes a single screw extruder (hereinafter referred to as an extruder) 11, a cooler 12 that is a cooling unit, and a heater 13. The single screw extruder 11 is provided with a refrigerant circulator 14 for circulating the refrigerant and a hopper 16 for introducing a dope raw material or swelling liquid (hereinafter collectively referred to as a raw liquid) 15. The dope raw material means a combination of the above-described polymer, a solute such as an additive added as necessary, and a solvent (may be a mixed solvent). The swelling liquid is produced from these raw materials by the aforementioned swelling process. In the following description, the stock solution 15 will be described using an example in which TAC is used as a polymer and methyl acetate is used as a solvent as a main solvent (composition ratio of methyl acetate is 30% to 98% by weight). The composition of the stock solution 15 used in the present invention is not limited to this.

(Cooling dissolution process)
The stock solution 15 is charged from the hopper 16, mixed while being cooled in the extruder 11, and compressed to obtain a dope 17 in which a solute such as a polymer is dissolved in a solvent. In the present invention, the terms “stock solution 15” and “dope 17” refer to a raw material for dope production (including a swelling solution) as a stock solution, and a dope obtained by dissolving or dispersing a solute in a solvent of the stock solution. Called. The state in which a part of the solute is dissolved in the solvent will be explained by the expression of either the stock solution 15 or the dope 17, but unless otherwise specified, in the extruder 11, a part of the solute of the stock solution becomes the solvent. It is dissolved.

  As shown in FIG. 2, the extruder 11 includes a screw 32 in which a screw blade 31 is attached to a screw shaft 30 in a cylinder 33. A jacket 34 is attached to the outer periphery of the cylinder 33. In the present invention, in order to control the temperature of the stock solution 15 or the dope 17 in the cylinder 33, if the jacket 34 is divided into a plurality of compartments, the temperature of the stock solution 15 or the dope 17 can be efficiently fed. It is preferable because it can be controlled. By controlling the temperature of the cylinder 33, it is possible to make the liquid feeding conditions of the stock solution 15 or the dope 17 appropriate, and the productivity of the dope can be improved. In FIG. 2, the temperature control is divided into two sections, ie, the first section (inlet side) 34a and the second section (outlet side) 34b. However, in the present invention, it may be divided into three sections or more. good.

  A thermometer 37 is attached to the extruder outlet 11a side of the extruder 11, and the temperature TD (° C.) of the dope 17 at the extruder outlet 11a (hereinafter referred to as outlet dope temperature) is measured. The refrigerant circulator 14 is controlled by the controller 38 so that For example, the exit dope temperature TD of the dope 17 at the extruder exit 11a is preferably set to −30 ° C. or less. However, the present invention includes controlling the dope temperature to an appropriate temperature according to the composition of the stock solution 15. Further, the temperature control is not limited to the automatic control by the controller 38, and it is also included in the present invention that the operator reads the measurement value of the thermometer and changes it appropriately.

  The refrigerants 35a and 35b are fed into the jacket first compartment 34a and the jacket second compartment 34b to cool the cylinder 33, and the stock solution 15 or dope 17 therein is cooled. The refrigerants 35a and 35b are not particularly limited, but methanol, hydrofluoroether, brine, or the like can be used. In the present invention, the temperature of the refrigerants 35 a and 35 b passed through the jacket can be regarded as the jacket temperature, and the jacket temperature can be regarded as the cooling temperature of the stock solution 15 or the dope 17.

  In the present invention, the cooling rate of the stock solution 15 or the dope 17 in the extruder 11 is preferably 5 ° C./min to 200 ° C./min. The cooling rate in the extruder 11 includes the temperature T0 (° C.) at which the stock solution 15 is put into the cylinder 33, the exit dope temperature TD (° C.), and the time during which the solution is fed in the extruder 11 (cooling time). In the present invention, a value calculated from (TD−T0) / Tc from Tc (min) is defined as a cooling rate.

  In order to cool the stock solution 15 or the dope 17 at a cooling rate of 5 ° C./min or more and 200 ° C./min or less, if the liquid feed rate of the refrigerants 35a and 35b is in the range of 0.1 m / s to 50 m / s, the solubility is increased. It is preferable for improvement. However, the liquid feeding speed of the refrigerants 35a and 35b is not limited to the above-described range. In addition, from the viewpoint of cooling efficiency, it is preferable that the refrigerants 35a and 35b are sent countercurrently to the liquid feeding direction of the stock solution 15 or the dope 17, but it is also possible to send the liquids in parallel flow. .

  If the temperature of the jacket second section (dope delivery side, outlet side) 34b is made lower than the temperature of the jacket first section 34a, the temperature of the inlet side (stock solution input side) 33a of the cylinder 33 (hereinafter referred to as cylinder inlet temperature). The relationship between T1 and the temperature of the outlet side (dope delivery side) 33b (hereinafter referred to as cylinder outlet temperature) T2 is T2 <T1. As a result, when a solute such as a polymer is not dissolved in the solvent, relatively slow cooling is performed to enable liquid feeding, and when dissolution progresses and liquid feeding becomes easy (that is, most of the stock solution 15 is doped 17. ), The solubility can be further improved by lowering the cooling temperature. Specifically, the cylinder inlet temperature T1 is set in the range of -30 ° C to 5 ° C, and the cylinder outlet temperature is set in the range of T2 to -100 ° C to -30 ° C. is not.

  The refrigerants 35a and 35b flow through the jacket first section 34a and the jacket second section 34b and then are sent to the refrigerant circulator 14. The refrigerants 35a and 35b whose temperature has been raised by the refrigerant circulator 14 are cooled again, and are fed again into the jacket first section 34a and the jacket second section 34b through the branch pipe 36. By circulating the refrigerants 35a and 35b in this manner, the refrigerants 35a and 35b are released into the atmosphere and do not affect the environment, and are advantageous from the viewpoint of cost. However, in the present invention, the refrigerant circulator 14 can be omitted. In FIG. 2, the liquid is fed to the jacket first section 34a and the jacket second section 34b via the branch pipe 36, but the jacket first section 34a and the jacket second are used by using two refrigerant circulators. The section 34b may be directly connected to each other by piping. Alternatively, there is a method in which liquid is fed from the refrigerant circulator 14 to the jacket second section 34b, the refrigerant 35 fed from the jacket second section 34b is fed to the jacket first section 34a, and then returned to the refrigerant circulator 14. Applicable.

As shown in FIG. 3, the screw 32 used in the present invention includes a supply part (first screw shaft part) 32a, a compression part (third screw shaft part) 32b, and a dope 17 on the input side (inlet side) of the stock solution 15. It forms from the measurement part (2nd screw shaft part) 32c to send out. The compression part 32b between the supply part 32a and the measurement part 32c spreads from the supply part 32a side toward the measurement part 32c side, and the gap with the cylinder 33 becomes narrow along the liquid feed direction of the stock solution 15 or the dope 17. Yes. The diameter da (mm) of the screw shaft of the supply unit 32a and the diameter dc (mm) of the screw shaft of the measuring unit 32c are:
da <dc (1)
Thus, the stock solution 15 or the dope 17 can be compressed. Specifically, the cylinder inner diameter D is 100 mm, the supply section groove depth d3 is 2 mm to 20 mm, the measurement section groove depth d4 is 1 mm to 9 mm, the supply section diameter da is 60 mm to 96 mm, and the measurement section diameter dc is 82 mm to Although the thing of the range of 98 mm is mentioned, It is not limited to these numerical ranges. The pitch P of the screw blades 31 is preferably in the range of D / 3 to 3 × D, where D is the cylinder inner diameter, but is not limited to that range.

When the lengths of the supply unit 32a, the compression unit 32b, and the weighing unit 32c are set to a supply unit length A (mm), a compression unit length B (mm), and a measurement unit length C (mm),
A ≦ B and C ≦ B (Equation 2)
With this relationship, the volumetric efficiency of the stock solution 15 is increased, and the dope 17 can be manufactured efficiently. Further, the relationship between the lengths A, B, and C is 1.1 ≦ (B / A) ≦ 4 and 1.1 ≦ (B / C) ≦ 4 (Equation 3)
As for the relationship, it is most preferable to use the one that can obtain the same effect and satisfies both (Equation 2) and (Equation 3) at the same time. Further, the theoretical discharge amount per revolution is calculated from the theoretical volume calculated from the screw groove depth. When the screw 32 satisfying (Equation 2) and (Equation 3) is used, the dope discharge amount of the screw 32 approaches the theoretical discharge amount, and the dope discharge amount per one rotation of the screw increases most. This is called low viscosity volumetric efficiency increase. In order to obtain the effect of increasing the low-viscosity volumetric efficiency, the supply part length A, compression part length B, and metering part length C constituting the screw 32 are not particularly limited. As a preferred example, it is preferable to use a supply unit length A of 180 mm to 1200 mm, a compression unit length B of 710 mm to 1330 mm, and a weighing unit length C of 180 mm to 1200 mm. It is not limited. In the present invention, the starting point of the length A of the supply portion 32a is the hopper end portion 16a which is the most upstream side when the hopper 16 is connected to the cylinder 33. The screw 32 used in the present invention can be manufactured using any known screw manufacturing method.

  The screw 32 rotates in the cylinder 33 with the rotation of a motor (not shown). When the stock solution 15 is introduced from the hopper 16 into the cylinder 33, the stock solution 15 is compressed, mixed and cooled in the order of the supply unit 32a, the compression unit 32b, and the measurement unit 32c, and the dissolution proceeds sequentially. As the screw blade 31 rotates, the stock solution 15 is pushed from the supply unit 32a into the compression unit 32b having a small liquid feeding cross-sectional area. In the compression part 32b, since the liquid feeding cross-sectional area becomes small toward the extruder exit 11a side, the stock solution 15 or the dope 17 is compressed. The uniform dope 17 is obtained by proceeding through the measuring unit 32c. Normally, heat is generated when the solute is dissolved or the liquid is compressed, but the screw 32 is cooled by the refrigerants 35a and 35b, the temperature in the cylinder 33 is kept constant, and the screw 32 is increased even if the pressure in the cylinder 33 increases. It can suppress that the rotation speed of decreases. Moreover, when the cooling efficiency in the cylinder 33 falls, it is necessary to lengthen the liquid feeding time of the undiluted solution 15 or dope 17 in it. In this case, it is necessary to reduce the rotational speed of the screw. However, if the temperature in the cylinder 33 is kept constant, there is no need to reduce the rotational speed. Further, according to the present invention, the preferable range of the pressure in the cylinder and the screw rotation speed is not particularly related, and can be set to any preferable condition according to other experimental conditions.

  In the present invention, when the center of the cross section of the cylinder 33 and the rotational axis of the screw shaft 30 are substantially coincided with each other, the gap between the screw shaft 30 and the cylinder 33 is referred to as a groove depth. Specifically, the groove depth d3 (mm) of the supply unit is in the range of 2 mm to 20 mm, and the groove depth d4 (mm) of the measuring unit is preferably in the range of 1 mm to 9 mm, more preferably 1.5 mm to Although it is in the range of 6 mm, it is not limited to these numerical ranges.

  In the present invention, the compression of the stock solution 15 or the dope 17 is a value indicated by the ratio (d3 / d4) of the supply section groove depth d3 (mm) and the measurement section groove depth d4 (mm). In the following description, it is referred to as a compression rate. Specifically, the compression ratio is preferably in the range of more than 1.0 times and not more than 5 times, but is not limited to this range. If the compression rate is 1.0 times or less, the stock solution 15 which is the configuration of the present invention is not compressed, and it may be difficult to obtain the effect of improving the productivity of the dope 17. Further, if the compression rate is larger than 5 times, it is difficult to rotate the screw 32 at a constant speed, and if it is severe, it may be impossible to rotate the screw 32 at all. Further, when the compression rate is increased, the pressure in the cylinder 33 increases and the cylinder 33 may be damaged. Furthermore, cooling solubility may deteriorate by increasing the compression rate.

In the present invention, the lead portion length L (mm) and the cylinder inner diameter D (mm) of the extruder 11 are set to 5 <(L / D) <50 (Equation 4).
By doing so, it becomes possible to manufacture the dope 17 efficiently. The starting point of the lead portion is the same hopper end portion 16a as the supply portion length A, and the ending point is the extruder outlet 11a. When (L / D) is 5 or less, the distance at which the stock solution 15 is cooled and dissolved is shortened, and in order to produce a dope, it is necessary to slow down the rotational speed of the screw and slow down the moving speed of the stock solution 15. May occur. When the moving speed is slowed, the effect of improving the productivity of the dope may be impaired. On the other hand, if it is 50 or more, the screw 32 becomes long, which hinders securing the installation location and increases the manufacturing cost of the extruder 11, which may not be preferable. Specifically, the lead portion length L is in the range of 150 mm to 20000 mm and the cylinder inner diameter D is in the range of 30 mm to 400 mm, but is not limited to these numerical ranges.

  In the present invention, the form of the extruder for compressing the stock solution 15 to improve the productivity of the dope 17 may be other than the illustrated one. For example, the dope can be manufactured by compressing the stock solution by narrowing the pitch P of the screw blades from the stock solution supply unit side toward the outlet side. Moreover, the extruder used for this invention is not limited to the thing provided with the single screw, For example, it is applicable also to the dope manufacturing apparatus using the extruder provided with the biaxial screw. Furthermore, in the present invention, the form of the screw of the extruder is not limited to the compression type, and a cooler can be attached to the downstream side of the conventional extruder and used as a dope manufacturing apparatus. Thereby, since the location where the screw which increases energy consumption in order to hold | maintain cooling temperature becomes short becomes short, energy consumption can be suppressed. In addition, since the dope solubility is improved by a cooler on the downstream side, a good-quality dope with little undissolved material can be obtained.

(Cooling and holding process)
It is preferable that the dope 17 in the extruder 11 is cooled and sent to the cooler 12 to further dissolve. The cooler 12 can reduce the liquid feeding resistance of the dope 17 by using a double pipe type pipe including the inner pipe line 12a and the outer pipe line 12b. It is preferable to use the outer pipe 12b divided into a plurality of sections (three sections in FIG. 1) because temperature control at each location of the cooler 12 can be easily performed. By passing the refrigerant 18 through the outer conduit 12b, the inner conduit 12a is cooled, and the dope 17 in the inner conduit 12a is cooled. By extending the cooling time using the cooler 12, the solubility of the dope 17 is improved, and the dope productivity can be improved. In the present invention, it is preferable that the time for the dope 17 to feed and cool the cooler 12 is 60 minutes or less in order to improve productivity. Even if it is longer than 60 minutes, the improvement in solubility is hardly seen, and it may be disadvantageous in terms of cost. However, a method of making the cooling time of the dope 17 by the cooler 12 longer than 60 minutes according to the composition of the stock solution 15 is also included in the present invention.

  The refrigerant 18 sent through the cooler 12 is sent to the refrigerant circulator 19. The refrigerant 18 whose temperature has risen by the refrigerant circulator 19 is cooled again and fed to the outer conduit 12 b via the branch pipe 20. Thereby, the usage-amount of the refrigerant | coolant 18 can be reduced and since the amount of refrigerant | coolants discharged | emitted in air | atmosphere becomes very trace amount, it is preferable also from the point of environmental protection. The refrigerant 18 used in the present invention is not particularly limited, but it is preferable to use methanol, hydrofluoroether, brine (trade name) or the like, and most preferably, fluorinate (trade name) which is one of hydrofluorocarbons. Is to use. In the present invention, it is not necessary to provide the refrigerant circulators 14 and 19 independently for each of the extruder 11 and the cooler 12, and these can be performed by one refrigerant circulator.

Volume (hereinafter referred to as extruder volume) V1 in which the stock solution 15 or dope 17 in the single screw extruder 11 is fed and volume in which the dope 17 is fed in the cooler 12 (hereinafter referred to as cooler volume). The ratio to V2 is 0.5 ≦ (V2 / V1) ≦ 100 (Equation 5)
It is preferable to use one having the relationship of When the ratio is smaller than 0.5, the cooling time is shortened. Therefore, the case where the effect of the present invention for improving the solubility is not sufficiently exhibited may occur. On the other hand, if the ratio is larger than 100, the size of the cooler 12 becomes too large, and it is difficult to secure the installation location, and the cost may be increased. Specifically, the extruder volume V1 is set to a range of 0.2 × 10 ⁻³ m ³ to 50 × 10 ⁻³ m ³ , and the cooler volume V2 is set to 0.1 × 10 ⁻³ m ³ to 50 × 10 ^{−. 1} in the range of m ^3, the ratio (V2 / V1) is preferably in the range of 0.5 ≦ (V2 / V1) ≦ 100, more preferably in the range of 0.7 ≦ (V2 / V1) ≦ 50, More preferably, the range is 1 ≦ (V2 / V1) ≦ 15, and the most preferable range is 1 ≦ (V2 / V1) ≦ 5.

The ratio (D2 / D) of the cylinder inner diameter D (mm) of the extruder 11 and the inner diameter D2 (mm) of the inner pipe 12a of the cooler 12 is 0.8 <(D2 / D) <10 (Equation 6) )
It is preferable to have the relationship. If the ratio (D2 / D) is 0.8 or less, the inner pipe inner diameter D2 is too small compared to the cylinder inner diameter D. Therefore, when the dope 17 is fed to the cooler 12, the pressure becomes high, and the dope feeding speed is constant. It may be difficult to achieve. Further, if it is outside the range of (Equation 6), the cost becomes high, the device is too large, and a large space is required to install the device, which is not preferable. Further, when the ratio (D2 / D) is 10 or more, there is a risk that the cost may be increased when manufacturing a device in which the centers of pipes having different inner diameters (used to include the cylinder 33) are matched. Specifically, when the cylinder inner diameter D is in the range of 50 mm to 500 mm and the inner pipe inner diameter D2 is in the range of 40 mm to 5000 mm, the ratio (D2 / D) is 0.8 <(D2 / D) <10. More preferably, the range is 0.9 <(D2 / D) <5, and the most preferable range is 1 <(D2 / D) <3.

By controlling the temperatures of the extruder 11 and the cooler 12 provided in the dope manufacturing apparatus 10, productivity when manufacturing the dope 17 from the stock solution 15 can be improved. In order to improve the solubility, it is preferable to further cool the dope 17 in the extruder 11, but using a long lead portion L of the extruder 11 increases the cost. Therefore, it is preferable that a cooler 12 that cools and holds the dope 17 in the extruder 11 is provided on the downstream side of the dope manufacturing apparatus 10. Since the dope 17 sent to the cooler 12 has already been dissolved due to the kneading effect of the extruder 11, the cooler 12 may be in the cooling zone, rather than lengthening the lead portion L of the extruder 11. Is preferable for cost reduction. The dope 17 is cooled in the cooler 12 to ensure solubility and further progress in dissolution. In this case, the temperature T (° C.) of the inner pipe 12a of the cooler is set to the cylinder outlet temperature T2 (° C.) described above.
T ≦ T2 (Equation 7 ′) is preferable,
More preferably, T ≦ 0.95 × T2 (Equation 7). Specifically, the temperature T (° C.) of the cooler 12 is preferably in the range of −85 ≦ T (° C.) ≦ −30, but is not limited to this range.

  In the dope manufacturing apparatus 10 of the present invention, it is most preferable to increase the temperature from the downstream side to the upstream side with respect to the liquid feeding direction of the dope 17 (or stock solution 15). The temperature may be increased toward the downstream side. The downstream side can be cooled most and the upstream side can be cooled at a temperature higher than that temperature by sequentially flowing the refrigerant into the outer pipe 12b, the jacket second section 34b, and the jacket first section 34a provided separately. . In this case, the refrigerant circulators 14 and 19 shown in FIG. 1 can be implemented by one unit, the amount of refrigerant used can be reduced, and the dope manufacturing apparatus 10 can be easily manufactured, which is advantageous in terms of cost. . Alternatively, a method may be used in which a coolant having the lowest temperature is flowed into the second section 34b, then sent to the outer conduit 12b, and finally the coolant is flowed in the order of the first section 34a.

  In the cooler outlet 12c that is in the most cooled state, the dope 17 is at a very low temperature (preferably −85 ° C. to −30 ° C., but not limited to this range), and the dope 17 is exposed to the atmosphere. In addition to the solidification of moisture in the atmosphere, the composition ratio of the dope 17 may change, and the physical properties of the dope may deteriorate. Therefore, in the present invention, it is preferable to directly connect the heater 13 to the cooler 12 to heat the dope 17. Moreover, solubility can also be improved by heating. However, the dope manufacturing apparatus 10 of the present invention can omit providing the heater 13. In this case, the dope 17 delivered from the cooler outlet 12c can be stored in a cooling container (not shown) in which the atmosphere is controlled, and heated when performing solution film formation to be described later. The heating process by the heater 13 will be described in detail later.

  If the dope 17 prepared by compressing the stock solution 15 has the target solubility, it is possible to omit attaching the cooler 12 to the dope manufacturing apparatus 10 of the present invention. Moreover, you may use the other form which does not attach the cooler 12. FIG. For example, the dope 17 prepared by the compression unit 32b can be made uniform by the measurement unit 32c by increasing the measurement unit length C of the extruder 11. Alternatively, the influence of the pressure increase associated with the rotation of the screw 32 is suppressed by providing a cylindrical cooling liquid feeding unit (not shown), which is not provided with the screw 32, on the downstream side of the measuring unit 32c. It is also possible to keep it cooled.

Instead of the cooler 12, a cooler 40 including an inner conduit 40a through which the dope 17 is fed and an outer conduit 40b in a vacuum state may be used. The inside of the outer conduit 40b is evacuated by the vacuum pump 41, and has a vacuum heat insulating structure. Vacuum of the outer conduit 40b is measured by the pressure gauge 42, preferably in the range of ^{0.5 × 10 -3 Pa~5 × 10 -3} Pa. By vacuuming the outer periphery of the dope 17 being fed, the temperature rise due to room temperature can be suppressed, the cooling temperature cooled by the extruder 11 can be maintained at substantially the same temperature, and the same effect as the cooler 12 can be obtained. be able to. In addition, as for the form of the cooler 40, it is preferable to use the thing of the same conditions as the cooler 12 except evacuating.

  Instead of the cooler 12 of the dope manufacturing apparatus 10, another screw extruder (not shown, hereinafter referred to as a second extruder) may be used. The second extruder is preferably a single screw or a twin screw. In this case, the second extruder is the same as the extruder (hereinafter, also referred to as the first extruder) 11 shown in FIG. It is possible to further improve the solubility of the dope by further cooling and mixing the dope obtained by cooling and dissolving in the second extruder. In addition, although the same thing as a 1st extruder may be used for a 2nd extruder, the thing of another form may be used. In this case, it is more preferable to use the same type as that of the cooler 12 described above because a uniform dope can be continuously produced. That is, the volume V1 of the first extruder and the volume V1 ′ of the second extruder are in the range of 0.5 ≦ (V1 ′ / V1) ≦ 100, and the cylinder inner diameter D of the first extruder and the second extruder cylinder The inner diameter D ′ is preferably in the range of 0.8 <(D ′ / D) <10. In the present invention, the volumes V1 'and D' of the second extruder are not limited to the above ranges.

(Heating process)
By supplying the dope 17 to the heater 13 connected to the cooler 12 and performing heating that rapidly raises the temperature, the solubility is further improved and the uniform dope 17 can be manufactured. The heating condition of the dope 17 by the heater 13 is not particularly limited, but the heating rate is 20 ° C./min or more, more preferably 30 ° C./min or more, and most preferably 40 ° C./min or more. The heating time is preferably 60 minutes or less, more preferably 30 minutes or less, and most preferably 10 minutes or less.

  According to the dope manufacturing method using the dope manufacturing apparatus 10 according to the present invention described above, when the dope manufacturing apparatus 10 having a cylinder inner diameter D of 100 mm is used, the dope 17 in which the solute is sufficiently dissolved in the solvent is reduced to 0. Productivity is high at 0.5 kg / min to 10 kg / min, and continuous production is possible.

(Processing after dope production)
The produced dope can be subjected to treatments such as concentration adjustment (concentration or dilution), filtration, temperature adjustment, and component addition as necessary. The component to be added is determined according to the use of the dope. Typical additives are plasticizers, deterioration inhibitors (eg, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, etc.), dyes and ultraviolet absorbers. The dope needs to be stored within a stable temperature range. For example, a dope prepared by cooling and dissolving cellulose triacetate with methyl acetate as a main solvent has two phase separation regions in a high temperature region and a low temperature region in a practical storage temperature range. In order to stably store this dope, it is necessary to maintain the temperature in the intermediate homogeneous phase region. The obtained dope is used for various applications. For example, it is sent to a film forming facility and used for manufacturing a film by a solution film forming method.

[Solution casting method]
The production of a film by the solution casting method, which is a typical use of the dope described above, will be described. FIG. 5 shows a schematic diagram of a film-forming facility 60 used in the present invention. In addition, in this embodiment, although the polymer which comprises dope demonstrates using a cellulose acylate, it is not limited to a cellulose acylate. The dope 17 obtained by the dope manufacturing method according to the present invention described above is charged in the mixing tank 61 and stirred by the stirring blade 62. At this time, it is also possible to mix an additive with the dope 17. The concentration of the dope 17 is preferably adjusted so that the solid content is 10 wt% to 30 wt%. The dope 17 is sent to the filtering device 64 at a constant flow rate by the pump 63 to remove impurities, and then sent to the casting die 65. In the present invention, the filtration device 64 can be omitted.

  The dope 17 is cast on the casting belt 66 from the casting die 65. In addition, although the temperature (casting temperature) of the dope 17 at this time is preferably in the range of −50 ° C. to 80 ° C., it is not limited to this range. The casting belt 66 is stretched around rollers 67 and 68 and travels endlessly by a driving device (not shown). The casting speed (moving speed of the casting belt) is preferably in the range of 0.5 m / s to 2 m / s in order to obtain a film having a uniform film thickness, but is not limited to this range. . The dope 17 cast on the casting belt 66 volatilizes the solvent gradually and becomes a film 69 having self-supporting properties. Note that the surface of the casting belt 66 is preferably finished in a mirror state. Further, a rotating drum (casting drum) can be used instead of the casting belt 66.

  The film 69 is peeled off from the casting belt 66 while being supported by the peeling roller 70, conveyed by the roller 71, and sent to the drying device 72. In addition, although it is preferable that the drying conditions of the drying apparatus 72 are the temperature of 100 to 160 degreeC and time for the range of 5 minutes-20 minutes, it is not limited to these ranges. It is more preferable to provide a large number of compartments in the drying device 72 and adjust the drying conditions in accordance with the amount of solvent contained in the film 69. Although it is preferable to send the film 69 from the drying device 72 to the cooling device 73 for cooling so that the film 69 is not deformed when the film 69 is wound later, the cooling device 73 can be omitted. In addition, although it is preferable that the film 69 is cooled to about room temperature with the cooling device 73, it is not limited to the temperature. The film 69 sent out from the cooling device 73 is conveyed by a roller 74 and taken up by a winder 75. In addition, you may give a knurling or may perform an ear-cut process etc., while conveying from the cooling device 73 to the winder 75. FIG. Further, the film 69 may be dried while being stretched using a tenter dryer for the drying device 72. Furthermore, you may provide a draw in the conveyance direction (longitudinal direction of a film) during conveyance before drying the film 69. FIG.

  The film production method (solution casting method) according to the present invention is not limited to the method described above. Other embodiments, particularly multilayer casting embodiments, will be described with reference to the drawings. 6 to 8, only the portions different from the above-described embodiment in the film forming equipment are illustrated and described, and descriptions and illustrations of the other portions are omitted.

  FIG. 6 shows a cross-sectional view of the main part of a form in which film formation is performed by the co-casting method. Film formation is performed using a multi-manifold casting die 83 having a plurality of manifolds 80, 81, and 82. Dopes 84, 85, 86 are supplied to the respective manifolds 80 to 82 (supply pipes are not shown), and after merging at the merging portion 87, the dopes 84 to 86 are cast onto the casting belt 88. After the casting film 89 is formed, a peeling film is obtained. In addition, when performing casting using the multi-manifold casting die 83 of FIG. 6, the film forming speed is improved by using at least one dope manufactured by the dope manufacturing apparatus and manufacturing method according to the present invention. Thus, the productivity of the film is improved. Most preferably, all of the three types of dopes 84 to 86 are manufactured by the dope manufacturing apparatus and the manufacturing method according to the present invention.

  FIG. 7 shows a side view of another embodiment for forming a film by the co-casting method. A feed block 101 is attached on the upstream side of the casting die 100, and dopes 102, 103, and 104 are fed from a liquid supply device (not shown) to pipes 101a, 101b, and 101c connected to the feed block 101. The dopes 102 to 104 are merged in the feed block 101 and then cast onto the casting belt 105 from the casting die 100. After the casting film 106 formed on the casting belt 105 has self-supporting properties, it is peeled off and dried to obtain a film. In addition, when performing the casting by providing the feed block 101 in the casting die 100 of FIG. 7, the dope produced by the dope production apparatus and the production method according to the present invention is used for at least one, so that the film forming speed is achieved. This improves the productivity of the film. Most preferably, all of the three types of dopes 102 to 104 are manufactured by the dope manufacturing apparatus and manufacturing method according to the present invention. Further, as the support in FIGS. 6 and 7, a rotating drum can be used instead of the casting belts 88 and 105.

  FIG. 8 shows a cross-sectional view of the main part of a form for forming a film using the sequential casting method. Three casting dies 110, 111, and 112 are disposed on the casting belt 113. The dopes 114, 115, and 116 are fed from the liquid feeder (not shown) to the casting dies 110 to 112, respectively. The dopes 114 to 116 are sequentially cast on the casting belt 113 to form a casting film 117, and then peeled off and dried to obtain a film. In addition, when performing sequential casting of FIG. 8, by using at least one dope manufactured by the dope manufacturing apparatus and manufacturing method according to the present invention, the film forming speed is improved and the productivity of the film is improved. improves. Most preferably, all of the three types of dopes 114 to 116 are manufactured by the dope manufacturing apparatus and manufacturing method according to the present invention.

  In addition to the embodiments described above, for example, a solution casting method using a supercooling casting method in which a rotating drum is used as a support and the rotating drum is cooled is also included in the present invention. In addition, when performing the sequential casting method shown in FIG. 8, a sequential co-casting method in which a multi-manifold casting die is used as the casting die or a feed block is attached to the upstream side of the casting die. It is included in the solution casting method.

[Film etc.]
Since the film (film base) obtained by any of the above solution casting methods has excellent dope uniformity, the film thickness is substantially constant and the optical properties are excellent. Further, since the dope productivity is high, the film productivity is excellent, which is advantageous from the viewpoint of cost. Moreover, since the film base excellent in the optical characteristic is used, the protective film manufactured using the base is also excellent in the optical characteristic. Furthermore, when the protective film is pasted on both surfaces of a polarizing film containing a polarizer, a polarizing plate having excellent optical properties can be produced. Furthermore, it can also be used as an optical functional film such as an optical compensation film having an optical compensation sheet affixed on the film or an antireflection film having an antiglare layer laminated on the film. These products (for example, polarizing plates, optical compensation films, etc.) can also constitute a part of a liquid crystal display device. Furthermore, a photographic photosensitive material can be produced by laminating a photosensitive layer or the like on a film base.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to these. The description will be made in detail in Experiment 1. For Experiments 2 to 5, Experiments 7 to 22, and Experiment 6, which is a comparative example, the description of the same conditions as in Experiment 1 is omitted. Later, experimental conditions, experimental results, and evaluation results are shown in Tables 1 to 8 together for each example.

[Production of Dope A]
In the experiment described below, a dope having the following formulation was manufactured, unless otherwise specified. This dope is referred to as dope A in the following description.
(polymer)
Cellulose triacetate (substitution degree 2.83, viscosity average degree of polymerization 320, water content 0.4 wt%, viscosity 6 wt% in methylene chloride (dichloromethane) solution 305 mPa · s)
28 parts by weight (solvent)
Methyl acetate 75 parts by weight Cyclopentanone 10 parts by weight Acetone 5 parts by weight Methanol 5 parts by weight Ethanol 5 parts by weight (additive)
Plasticizer A (dipentaerythritol hexaacetate) 1 part by weight Plasticizer B (triphenyl phosphate; TPP) 1 part by weight fine particles (silica (particle size 20 nm)) 0.1 part by weight UV agent a: (2,4- Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine
0.1 part by weight UV agent b: 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole 0.1 part by weight UV agent c: 2 (2′-hydroxy -3 ′, 5′-di-tert-amylphenyl) -5-chlorobenzotriazole 0.1 part by weight C ₁₂ H ₂₅ OCH ₂ CH ₂ O—P (═O) — (OK) ₂ 0.05 part by weight The UV agent means an ultraviolet absorber.

[Method for evaluating manufactured dope]
The dope A produced in each experiment to be described later was performed in six stages according to the following criteria from visual evaluation. The visual evaluation was performed by sampling the dope in a glass bottle and applying light to evaluate the amount of undissolved foreign matter in the dope.
Especially very good ...
Very good
Good ・ ・ △
Bad
In addition, since silica which is fine particles has a small particle size, it cannot be visually observed and does not affect the present evaluation.

  In Example 1, the experiment was performed by changing the compression rate and the number of screw shafts. In Experiment 1, a dope was produced using a compression type extruder 11 for the screw. The solute composed of the polymer and additive in the formulation for producing the dope A was combined with the mixed solvent and charged into the hopper 16 as a stock solution 15. And it sent to the single screw extruder 11 from the hopper 16. In addition, temperature T0 of the stock solution 15 at this time was 30 degreeC. As the screw 32, a supply part 32a having a length A of 250 mm, a groove depth of 6 mm, a compression part 32b having a length B of 500 mm, a measuring part 32c having a length C of 250 mm and a groove depth of 3 mm was used. That is, the form of the screw 32 was A ≦ B and C ≦ B, and B / A = 2.0 and B / C = 2.0. The inner diameter D of the cylinder 33 was 30 mm, and the ratio of the lead portion length L / inner diameter D was 33.3. The jacket 34 provided on the outer periphery of the cylinder 33 is divided into two parts. The jacket first section 34a has a −45 ° C. refrigerant (Fluorinert; trade name), and the jacket second section 34b has Refrigerants (Fluorinert; trade name) at −70 ° C. were fed, respectively, and the cylinder inlet temperature T1 was −45 ° C. and the cylinder outlet temperature T2 was −70 ° C. Cooling dissolution was performed while maintaining the rotation speed of the screw 32 at 7 rpm, and the dope production flow rate was 50 g / min. At this time, the exit dope temperature TD of the dope 17 at the extruder exit 11a was −69.9 ° C.

  Moreover, each experimental condition of Experiment 2 and Experiment 3 and Experiment 6 which is a comparative example was performed under the same conditions as in Example 1 except that they were described in Table 1. In Experiment 4 and Experiment 5, a twin screw extruder was used. As the twin screw extruder, a meshing type rotating in the same direction was used. In Experiment 4, a twin screw extruder was used under the same conditions as in Experiment 6, and in Experiment 5, a twin screw extruder was used under the same conditions as in Experiment 2. The experimental conditions and evaluation results (solubility) are summarized in Table 1.

  From Table 1, it was found that the solubility was improved by compressing the stock solution 15 or the dope 17 with the extruder 11. Particularly, in Experiment 1 in which the compression ratio was 2.0 times, an extremely good dope (◯) was obtained. It was also found that the solubility was improved by using a twin screw extruder (Experiment 4 and Experiment 5). Experiment 4 shows that a good dope (Δ) can be obtained even when the compression ratio is 1.0. From this, it was found that the same effect as compression can be obtained by using a twin screw.

  In Example 2, an experiment was performed in which the depth of the measuring portion groove depth d4 was changed. The other conditions were the same as those in Experiment 1 described above. In this experiment, an experiment 7 using a screw having a measuring portion groove depth d4 of 1.4 mm and an experiment 8 using a screw having a measuring portion groove depth d4 of 7 mm were performed. The experimental conditions and evaluation results are summarized in Table 2 together with Experiment 6 which is a comparative example.

  From Table 2, it was found that the solubility of the dope is improved by setting the compression ratio to be greater than 1 and 5 or less. Further, it was found that in Experiment 1 in which the measuring portion groove depth d4 is 3 mm, a very good dope (◯) can be obtained.

  In Example 3, Experiment 9 in which the form of the screw 32 was changed was performed. The other conditions were the same as those in Experiment 1 described above. In Experiment 9, instead of the extruder 11 used in Experiment 1, a cylinder having an inner diameter D of 100 mm and a lead portion length L / cylinder inner diameter = 20.0 was used. In this extruder, a feed section length A of 666 mm, a feed section groove depth d3 of 6 mm, a compression section length B of 666 mm, a weighing section length C of 666 mm, and a weighing section groove depth d4 of 3 mm were used. That is, the form of the screw had a relationship of A = B, C = B and B / A = 1.0, B / C = 1.0. Table 3 summarizes the experimental conditions and the evaluation results.

  From Table 3, in Experiment 1 using the ratio of the length B of the compression portion increased (B / A = 2.0, B / C = 2.0), the present invention of preparing a dope by compression It was found that the effect of.

  In Example 4, experiments in which the conditions for cooling the cylinder 33 were changed were performed as Experiment 10 and Experiment 11. The other conditions were the same as those in Experiment 1 described above. In Experiment 10, a −70 ° C. refrigerant (Fluorinert; trade name) was supplied to the jacket first section 34a and the jacket second section 34b, and the cylinder inlet temperature T1 and the cylinder outlet temperature T2 were set to −70 ° C., respectively. In Experiment 11, a −45 ° C. refrigerant (Fluorinert; product name) was sent to the first jacket section 34a and the second jacket section 34b, which were divided into two parts, and the cylinder inlet temperature T1 and the cylinder outlet temperature T2 were respectively − The temperature was 45 ° C. The experimental conditions and evaluation results are summarized in Table 4.

  From Table 4, a dope (◯) having the highest solubility was obtained in Experiment 1 in which the cylinder inlet temperature T1 was −45 ° C. and the cylinder outlet temperature T2 was −70 ° C. In the case of the stock solution 15, the cooling temperature was slightly increased to −45 ° C., and the dissolution proceeded further by lowering the cooling temperature to −70 ° C. after the dissolution progressed and the liquid feeding became easy. It is considered a thing.

In Example 5, the experiment was performed by changing the liquid feed rate of the stock solution (or dope) in the extruder 11 to change the cooling rate of the stock solution (or dope) in the extruder 11. In Experiment 1, when the rotational speed of the screw 32 was adjusted so that the liquid feeding speed was 5 × 10 ⁻⁵ m ³ / min, the dope production flow rate was 50 g / min. Also, the volume that can feeding the stock solution 15 or doped 17 in the extruder 11 (extruder volume) V1 is, 35 × a 10 ^-5 m ^3, the residence time of the stock solution 15 or doped 17 in the extruder 11 ( Tc (which can be regarded as a cooling time) was 7 minutes. The dope temperature (exit dope temperature) TD at the exit 11 a of the extruder was −70 ° C. as measured by the thermometer 37. Moreover, temperature T0 of the stock solution 15 mentioned above was 30 degreeC, and the average cooling rate of the stock solution (or dope) in the extruder 11 was 15 degreeC / min from (T0-TD) / Tc. The experiments 12 and 13 were performed under the same conditions as those of the experiment 1 except for the conditions in Table 5 shown later.

From Experiment 5, in Experiment 1 in which the liquid feeding speed was 5 × 10 ⁻⁵ m ³ / min, the cooling time Tc in the extruder 11 was 7 minutes and the outlet dope temperature TD was −70 ° C., so the cooling time Tc was 0. It was found that a dope (◯) having excellent solubility as compared with Experiment 12 in which the exit dope temperature TD was −65 ° C. for 5 minutes was obtained. Further, in Experiment 13 in which the liquid feeding speed was 18 × 10 ⁻⁶ m ³ / min, the dope solubility was good (◯), but the dope production flow rate was as small as 18 g / min, and the productivity deteriorated.

  In Example 6, the cooling was performed on the downstream side of the extruder 11 used in Experiment 1 described above. The description will be made in detail in Experiment 14. For Experiments 15 to 17, parts where the experimental conditions are different will be shown in Table 6 together with the evaluation results later.

In Experiment 14, as shown in FIG. 1, a cooler (shown as a double pipe in Table 6) 12 as a double pipe type pipe was attached to the downstream side of the extruder 11. A double pipe type pipe having an inner pipe inner diameter D2 of 30 mm and a length of 1000 mm was used. Further, a refrigerant (Fluorinert; trade name) 18 having a temperature of −70 ° C. is fed to the outer conduit 12 b, and the temperature T (considered as the temperature of the cooler) of the inner conduit 12 a of the cooler 12 becomes −70 ° C. The refrigerant circulator 19 was used for control. The screw speed of the upstream extruder 11 was controlled so that the dope production flow rate was 50 g / min. In Experiment 15, the extruder (second extruder) used in Experiment 1 was used as the cooler instead of the double pipe cooler. In addition, this 2nd extruder sent the refrigerant | coolant (Fluorinert; brand name) of -70 degreeC in the jacket, and set the temperature of the cylinder to -70 degreeC. In this experiment, the cylinder temperature was regarded as the cooler temperature T (° C.). In Experiment 16, the refrigerant 18 is fed to the outer pipe 12b of the double pipe type pipe, and the temperature T is -60 ° C., which is higher than the cylinder outlet temperature T2 (−70 ° C.) of the extruder 11 (T2 <T )did. In the cooler 40 (see FIG. 4) used in Experiment 17, the inner diameter of the inner conduit 40a is 30 mm and the length is 1000 mm. The outer conduit 40b is evacuated by a vacuum pump 41 was 1 × 10 ^-3 Pa was measured by the pressure gauge 42. In addition, the experiment 1 which does not use a cooler is also shown collectively.

  From Table 6, the solubility of the dope produced by the methods of Experiments 14 to 17 in which cooling was performed after compression and dope preparation according to the present invention was very good (◎). It should be noted that the solubility of the dope was particularly good (◎) even in Experiment 16 in which cooling was performed with the temperature T of the cooler higher than the cylinder outlet temperature T2. Also in Experiment 17 using the cooler 40 having a vacuum heat insulating tube structure, an extremely good dope (◎) could be obtained. In the present invention in which the highly viscous dope is manufactured by cooling, it has been found that it is preferable to use a double-pipe pipe that can suppress an increase in pressure with a cooler.

In Example 7, an experiment was performed using a different size (cooler volume V2) of the cooler (double pipe type pipe). The double pipe type pipe used in Experiment 14 described above had an inner pipe inner diameter D2 of 30 mm and a length of 1000 mm. The volume V2 of this double pipe type pipe is 7.1 × 10 ⁻⁴ m ³ . The volume V1 through which the stock solution (or dope) can pass through the extruder 11 is 3.5 × 10 ⁻⁴ m ³ , and the volume ratio (V2 / V1) is 2. The ratio (D2 / D) of the inner pipe inner diameter D2 of the double pipe type piping to the cylinder inner diameter D of the extruder 11 was 1.0. -70 degreeC refrigerant | coolant (Fluorinert; brand name) was sent to the outer pipe line of this double pipe type piping, and the cooler temperature T was cooled to -70 degreeC. Moreover, the rotation speed of the screw 32 of the extruder 11 was adjusted so that dope manufacture flow volume might be 50 g / min. In Experiment 18, a double pipe type pipe having an inner pipe inner diameter D2 of 30 mm and a length of 800 mm was used. The volume ratio (V2 / V1) was 1.6, and the inner diameter ratio (D2 / D) was 1.0. In Experiment 19, an inner pipe inner diameter D2 of 30 mm and a length of 3500 mm were used (volume ratio (V2 / V1) is 24.9, inner diameter ratio (D2 / D) is 1.0). . Further, in Experiment 20, an inner pipe inner diameter D2 of 24 mm and a length of 1550 mm were used (volume ratio (V2 / V1) is 2, inner diameter ratio (D2 / D) is 0.8). Table 7 shows the experimental conditions and evaluation results of Experiment 14, Experiment 18 to Experiment 20.

  From Table 7, the dope obtained in Experiment 14 in which the length of the double pipe was 1000 mm was extremely superior in solubility than the dope obtained in a length of 3500 mm (５００). In the present invention, it is considered that the length of the double pipe is set to 1000 mm, which is a suitable length for feeding the dope 17. In addition, the experiment 14 in which the inner diameter D2 of the double pipe is 30 mm is better than the experiment 20 in which the inner diameter D2 is 24 mm. This is considered to be a pipe diameter suitable for feeding the dope. Therefore, it was found that the dope can be continuously fed stably by setting the relationship between the cylinder inner diameter D and the inner pipe inner diameter D2 to be 0.8 <(D2 / D) <10.

  In Example 8, an experiment was performed in which the heater 13 was attached to the downstream side of the cooler 12. In Experiment 21, the heating process was performed after the cooling and holding process under the same conditions as in Experiment 14 described above. A heater manufactured by Noritake Company Limited was used as the heater 13 and the heating rate was 40 ° C./min. Experiment 22 was performed under the same conditions as Experiment 21 except that the heating rate was 18 ° C./min. The results are shown together in Table 8 together with Experiment 1 described above.

  It was found from Table 8 that in the experiments 21 and 22 where heating was performed, the solubility was improved (◎). The dope obtained in Experiment 21 was more soluble than the dope obtained in Experiment 22. Thus, it was found that the faster the heating rate, the better the solubility.

  As described above, from Experiment 1 to Experiment 5 and Experiment 7 to Experiment 22 according to the present invention and Experiment 6 which is a comparative example, the dope manufacturing apparatus and the manufacturing method according to the present invention have a screw shape as a compression type, and are downstream of the extruder. It was found that the best dope can be obtained by attaching a cooler and a heater on the side. At this time, in order to facilitate the feeding of the stock solution (or dope), the relationship between the compression rate and the length of each screw part (A ≦ B, C ≦ B and 1.1 ≦ (B / A) ≦ 4, 1.1 ≦ (B / C) ≦ 4), the groove depth of the metering section, the temperature conditions of the extruder, the cooler and the heater, the ratio between the lead portion of the extruder and the cylinder inner diameter (L / D) , Form of the cooler, volume ratio of the extruder to the cooler (V2 / V1), ratio of the cylinder inner diameter D to the inner pipe diameter D2 of the cooler (D2 / D), the exit dope temperature TD of the extruder, the extruder The dope with the most improved solubility is selected by selecting the experimental conditions such as the cooling rate in the furnace, the cooling time in the cooler, and the relationship between the cylinder outlet temperature T2 of the extruder and the cooler temperature T (T ≦ T2). Can be manufactured.

[Preparation of dope B]
The dope B was prepared using the following formulation. In addition, the preparation was diluted with the above-described dope A so as to have the following composition ratio.
(polymer)
Cellulose triacetate (substitution degree 2.83, viscosity average degree of polymerization 320, water content 0.4 wt%, viscosity 6 wt% in methylene chloride solution 305 mPa · s)
25 parts by weight (solvent)
Methyl acetate 75 parts by weight Cyclopentanone 10 parts by weight Acetone 5 parts by weight Methanol 5 parts by weight Ethanol 5 parts by weight (additive)
Plasticizer A (dipentaerythritol hexaacetate) 1 part by weight Plasticizer B (TPP) 1 part by weight fine particles (silica (particle size 20 nm)) 0.1 part by weight UV agent a: (2,4-bis- (n- Octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine
0.1 part by weight UV agent b: 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole 0.1 part by weight UV agent c: 2 (2′-hydroxy -3 ′, 5′-di-tert-amylphenyl) -5-chlorobenzotriazole 0.1 parts by weight C ₁₂ H ₂₅ OCH ₂ CH ₂ O—P (═O) — (OK) ₂ 0. 05 parts by weight

[Production of film]
The above-mentioned dope A (manufactured under the experimental conditions of Experiment 13) and dope B were prepared. A three-layer film having dope A as an intermediate layer and dope B as a front layer and a back layer was produced by a solution casting method. In the solution casting apparatus, three layers of co-casting were performed using the feed block type casting die shown in FIG. The casting belt as a support was run endlessly at 50 m / min. Casting is performed so that the surface layer and the back layer of the dried film have a thickness of 3 μm and the intermediate layer has a thickness of 74 μm. After the casting film has self-supporting properties, the film is peeled off as shown in FIG. It was peeled off from the casting belt while being supported by the take-off roller 70. Thereafter, the film was dried with a tenter dryer at about 135 ° C. for about 3 minutes while stretching. Thereafter, the film was dried at about 145 ° C. for about 15 minutes with a drying device, cooled for about 2 minutes with a cooling device at about 60 ° C., and wound up with a winder to obtain a film having a film thickness of 80 μm.

The in-plane retardation (Re) of the above-mentioned film was measured at a wavelength of 632.8 nm using an ellipsometer (Analytical ellipsometer AEP-100: manufactured by Shimadzu Corporation). The in-plane retardation (Re) is obtained by multiplying the in-plane longitudinal and lateral refractive index difference by the film thickness, and is obtained by the following formula.
Re = (nx−ny) × d
nx = refractive index in the horizontal direction, ny = refractive index in the vertical direction, d = film thickness In the present invention, the line conveyance direction during film production is defined as vertical and the film width direction is defined as horizontal. The in-plane retardation (Re) is preferably as small as possible. When the film was measured, it was found to be 2 nm and excellent in optical properties.

  Using the film, an antireflection film by coating was produced by the following procedure.

(Preparation of coating solution A for antiglare layer)
439 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) 125 g, bis (4-methacryloylthiophenyl) sulfide (MPSMA, Sumitomo Seika Co., Ltd.) 125 g Of methyl ethyl ketone / cyclohexanone = 50/50% by weight in a mixed solvent. In the obtained solution, a solution obtained by dissolving 5.0 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and 3.0 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) in 49 g of methyl ethyl ketone. added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.60.

  Furthermore, 10 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) were added to this solution, and the mixture was stirred and dispersed at 5000 rpm for 1 hour with a high speed dispaper, and then the pore diameter was 30 μm. The coating liquid A of the anti-glare layer was prepared by filtering with a polypropylene filter.

(Preparation of coating solution B for antiglare layer)
To a mixed solvent of 24 g of cyclohexanone and 28 g of methyl ethyl ketone, 218 g of a hard coat coating solution containing zirconium oxide dispersion (Desolite Z-7401, manufactured by JSR Corporation) was added while stirring with an air disperser. Further, 91 g of Kaylad DPHA and 10 g of Irgacure (Ciba Geigy) were added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61. Further, 5 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) were added to this solution, and the mixture was stirred and dispersed at 5000 rpm for 1 hour with a high speed dispaper, and then the pore diameter was 30 μm. The coating liquid B of the anti-glare layer was prepared by filtering with a polypropylene filter.

(Preparation of coating solution C for antiglare layer)
52 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) 91 g, zirconium oxide dispersion-containing hard coat coating solution (Desolite Z-7401, JSR Co., Ltd.) 218 g Of methyl ethyl ketone / cyclohexanone = 54/46% by weight in a mixed solvent. 10 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) was added to the resulting solution. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61. Further, 20 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) were added to this solution in a mixed solvent of 80 g of methyl ethyl ketone / cyclohexanone = 54/46 wt% at a high speed disperser at 5000 rpm. After adding and stirring 29 g of the dispersion obtained by stirring and dispersing for 1 hour, the mixture was filtered through a polypropylene filter having a pore size of 30 μm to prepare an antiglare layer coating solution C.

(Preparation of coating liquid D for hard coat layer)
A solution prepared by dissolving 250 g of an ultraviolet curable hard coat composition (Desolite Z-7526, 72% by weight, manufactured by JSR Corporation) in 62 g of methyl ethyl ketone and 88 g of cyclohexanone was added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.53. Further, this solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating liquid D for hard coat layer.

(Preparation of coating solution for low refractive index layer)
Thermally crosslinkable fluorine-containing polymer having a refractive index 1.42 (TN-049, manufactured by JSR (Co.)) 20093g the MEK-ST (average particle size: 10 to 20 nm, solid concentration 30 wt% of SiO ₂ sol of MEK (for methyl ethyl ketone ) 8 g dispersion (manufactured by Nissan Chemical Co., Ltd.) and 100 g MEK were added, and after stirring, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer.

On the cellulose triacetate film having a thickness of 80 μm having a three-layer structure prepared by the above-described method, the above-mentioned coating liquid D for hard coat layer is applied with a bar coater, dried at 120 ° C., and then 160 W / cm air-cooled metal halide. Using a lamp (manufactured by Eye Graphics Co., Ltd.), an ultraviolet ray having an illuminance of 400 mW / cm ² and an irradiation amount of 300 mJ / cm ² was irradiated to cure the coating layer to form a 2.5 μm thick hard coat layer. .

  On the hard coat layer, the anti-glare layer coating liquid A is applied with a bar coater, dried under the same conditions as the hard coat layer, and UV-cured to form an anti-glare layer A having a thickness of about 1.5 μm. Formed. On top of that, the low refractive index layer coating solution was applied with a bar coater, dried at 80 ° C., and then thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. An antireflection film A was obtained. Further, the anti-glare layer coating solution A was replaced with the anti-glare layer coating solution B, and the others were coated under the same conditions to obtain an antireflection film B. Further, the anti-glare layer coating solution A was replaced with the anti-glare layer coating solution C, and the others were coated under the same conditions to obtain an antireflection film C.

(Evaluation of antireflection film)
Regarding the obtained antireflection films A to C, the following items were evaluated, and the obtained measurement results are collectively shown in Table 9 later.

(1) Specular reflectance and tint A spectrophotometer V-550 (manufactured by JASCO Corporation) is equipped with an adapter ARV-474, and an emission angle of -5 at an incident angle of 5 ° in a wavelength region of 380 nm to 780 nm. The specular reflectivity was measured, the average reflectivity between 450 nm and 650 nm was calculated, and the antireflection property was evaluated.

  Further, CIE 1976 L * a * b * color space L * value, a * value, and b * value representing the color of the specularly reflected light with respect to the 5 degree incident light of the CIE standard light source D65 are calculated from the measured reflection spectrum. The color of reflected light was evaluated.

(2) Integral reflectance The spectrophotometer V-550 (manufactured by JASCO Corporation) is fitted with an adapter ILV-471, and the integral reflectance at an incident angle of 5 ° is measured in the wavelength region of 380 nm to 780 nm. The average reflectance of 450 nm to 650 nm was calculated.

(3) Haze The haze of the obtained antireflection film was measured using a haze meter MODEL 1001DP (manufactured by Nippon Denshoku Industries Co., Ltd.).

(4) Pencil hardness evaluation Pencil hardness evaluation described in JIS K 5400 was performed as an index of scratch resistance. After conditioning the antireflection film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a 3H test pencil specified in JIS S 6006, with a load of 1 kg
No scratch is observed in the evaluation of n = 5: ○
In evaluation of n = 5, 1 or 2 scratches:
In evaluation of n = 5, 3 or more scratches: ×
A three-stage evaluation was performed.

(5) Contact angle measurement As an index of surface contamination resistance, the optical material was conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and then the contact angle against water was measured to obtain an index of fingerprint adhesion.

(6) Dynamic friction coefficient measurement The dynamic friction coefficient was evaluated as an index of surface slipperiness. As the dynamic friction coefficient, a sample was conditioned at 25 ° C. and a relative humidity of 60% for 2 hours, and then a value measured with a HEIDON-14 dynamic friction measuring machine at a 5 mmφ stainless steel ball, a load of 100 g, and a speed of 60 cm / min was used.

(7) Evaluation of anti-glare property An exposed fluorescent lamp (8000 cd / m ² ) without a louver was projected on the prepared anti-glare film, and the degree of blur of the reflected image was evaluated according to the following criteria.
I do not know the outline of the fluorescent lamp at all: ◎
Slightly understand the outline of the fluorescent lamp: ○
The fluorescent lamp is blurred, but the outline can be identified: △
Fluorescent lamp is hardly blurred: ×
A four-step evaluation was performed.

  From Table 9, it was found that an antireflection film based on a film obtained by solution film formation using a dope obtained by the dope manufacturing method according to the present invention has excellent optical properties. In particular, the antiglare and antireflection properties were excellent, the color was weak, and the evaluation results reflecting film properties such as pencil hardness, fingerprint adhesion, and dynamic friction coefficient were also good.

  Next, an antiglare antireflection polarizing plate was prepared using the film having a three-layer structure (film thickness: 80 μm). Using this polarizing plate, a liquid crystal display device in which an antireflection layer was disposed on the outermost layer was created. As a result, there was no reflection of external light, and excellent contrast was obtained. Visibility was good and fingerprinting was good.

It is the schematic of the dope manufacturing apparatus of this invention. It is a principal part schematic sectional drawing of the dope manufacturing apparatus shown in FIG. It is a principal part schematic diagram for demonstrating the characteristic of the dope manufacturing apparatus shown in FIG. It is the principal part schematic of other embodiment of the dope manufacturing apparatus of this invention. It is the schematic of the solution casting apparatus used for the solution casting method of this invention. It is principal part sectional drawing of other embodiment of the solution casting apparatus used for the solution casting method of this invention. It is a principal part schematic diagram of other embodiment of the solution casting apparatus used for the solution casting method of this invention. It is principal part sectional drawing of other embodiment of the solution casting apparatus used for the solution casting method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dope manufacturing apparatus 11 Extruder 12 Cooler 12b Outer pipe line 13 Heater 17 Dope 32 Screw 32a Supply part 32b Compression part 32c Measurement part 33 Cylinder 60 Film-forming equipment 69 Film A Supply part length B Compression part length C Measurement part length D Cylinder inner diameter D2 Inner pipe inner diameter L Lead length d4 Measuring section groove depth

Claims (13)

In order to dissolve the cellulose acylate in the solvent, the liquid containing the cellulose acylate and the solvent is kneaded using rotation of a screw accommodated in the cylinder, and the kneaded liquid is discharged from the extrusion port of the cylinder. In a dope production apparatus that has an extruder for extruding and produces a dope in which the cellulose acylate is dissolved in the solvent,
In order to dissolve the undissolved cellulose acylate contained in the liquid in the solvent, a cooler that cools the liquid pushed out by the extruder, and heating that heats the liquid fed from the cooler Have a machine,
A cooling jacket for cooling the liquid in the cylinder is provided in the cylinder;
The screw includes a screw shaft and a spiral blade provided on the screw shaft. The screw shaft is provided on a side closer to the extrusion port than the first screw shaft portion and the first screw shaft portion. A second screw shaft portion having a diameter larger than that of the screw shaft portion, and a compression shaft portion connecting the first screw shaft portion and the second screw shaft portion, and a gap between the cylinder and the compression shaft portion is Narrow along the liquid feed direction,
The dope manufacturing apparatus, wherein the concentration of the cellulose acylate in the dope is 10 wt% to 30 wt%. The dope manufacturing apparatus according to claim 1, wherein the solvent contains at least one of methyl acetate and acetone. A plurality of cooling jackets for cooling the liquid in the cylinder are arranged in the feeding direction, and the temperature of the refrigerant flowing in the cooling jacket on the downstream side in the feeding direction flows to the cooling jacket on the upstream side in the feeding direction. The dope manufacturing apparatus according to claim 1 or 2, wherein the temperature is lower than a temperature of the refrigerant to be used. The ratio V2 / V1 of the volume V1 of the liquid circulation section provided in the extruder and the volume V2 of the liquid circulation section provided in the cooler is 0.5 or more and 100 or less. The dope manufacturing apparatus according to claim 1 or 3. The dope manufacturing apparatus according to any one of claims 1 to 4, wherein a gap between the second screw shaft portion and the cylinder is 1.5 mm or more and 6 mm or less. When the length of the first screw shaft portion is A, the length of the compression shaft portion is B, and the length of the second screw shaft portion is C,
The value of B / A is 1.1 or more and 4 or less,
Dope production apparatus according to any one of claims 1, characterized in that the value of B / C is 1.1 to 4 5. In a dope production method comprising a dissolving step of dissolving cellulose acylate in a solvent, and producing a dope in which the cellulose acylate is dissolved in the solvent,
The dissolving step includes
A cooling extrusion process for cooling the liquid while kneading the liquid containing the cellulose acylate and the solvent using rotation of a screw housed in a cylinder;
After completion of this cooling extrusion process, the solution containing the cellulose acylate undissolved, the cooling holding step of cooling at an internal conduit of the cooling machine,
After completion of this cooling holding step, and a heating step of heating the solution containing the cellulose acylate undissolved,
In the cooling extrusion process, the liquid is compressed,
The concentration of the cellulose acylate in the dope is 10 wt% to 30 wt%,
The screw includes a screw shaft and a spiral blade provided on the screw shaft, and the screw shaft is provided on the downstream side in the liquid feeding direction from the first screw shaft portion and the first screw shaft portion, A second screw shaft portion having a diameter larger than that of the first screw shaft portion; a compression shaft portion connecting the first screw shaft portion and the second screw shaft portion; and the cylinder and the compression shaft portion. The dope manufacturing method, wherein the gap narrows along the liquid feeding direction . The dope manufacturing method according to claim 7, wherein the solvent contains at least one of methyl acetate and acetone. The dope according to claim 7 or 8, wherein in the cooling and extruding step, the temperature of the cylinder is adjusted so that the temperature T1 at the inlet of the cylinder is higher than the temperature T2 at the outlet of the cylinder. Production method. The dope manufacturing method according to claim 9, wherein the temperature of the inner pipe of the cooler is (0.95 × T2) or less. The dope manufacturing method according to claim 9 or 10, wherein the temperature T2 is -100 ° C to -30 ° C. The method of preparing the dope any one of claims 7 to 11, characterized in that the time for performing the cooling holding step within 60 minutes. The dope manufacturing method according to any one of claims 7 to 12, wherein, in the cooling extrusion step, a cooling rate of the liquid is 5 ° C / min or more and 200 ° C / min or less.

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