JP2008080737A - Solution film forming equipment and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely regulate the amount of additive component in a dope when a film is formed by multilayer casting. <P>SOLUTION: Dope flow channels 48-50 for a base layer, the outer layer on the side of a support and the outer layer on the side of air are provided to a dope manufacturing line 10. First-third additive charging devices 52-54 for charging additives 63, 68 and 69 are provided on the way of the respective flow channels 48-50. The amount of component of a raw material dope 35 before the additives are charged is measured on-line by a first near infrared spectral analyzer 110 to determine first-third amounts of corrected adding for charging the respective additives 63, 68 and 69. The amounts of components of dopes 43-45 for the respective layers prepared on the basis of the respective amounts of corrected adding are measured on-line by second-fourth near infrared spectral analyzers 112, 128 and 130. In a case that the amounts of components of the additives 63, 68 and 69 of the dopes 43-45 for the respective layers do not reach target values, the first-third amounts of corrected adding are corrected. When the film is formed by multilayer casting, the amount of additive components in the dopes 43-45 for the respective layers can be precisely regulated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solution casting apparatus and method for obtaining a polymer film by multi-casting a plurality of dopes in which a polymer is dissolved in a solvent on a support, and then peeling off and drying the dope.

  A TAC film formed from a cellulose ester, particularly a cellulose triacetate (hereinafter referred to as “TAC”) having an average degree of acetylation of 58.0% to 58.5%, is characterized by its toughness and flame retardancy. It is used as a film support. In addition, since the TAC film is excellent in optical isotropy, it is also used as a protective film for a polarizing plate of a liquid crystal display device whose market is expanding in recent years.

  A solution casting method is well known as a method for producing a TAC film. The solution casting method can produce a film having excellent physical properties such as optical properties as compared with other production methods such as a melt casting method. In the solution casting method, first, various additives such as an ultraviolet absorber (UV agent), a matting agent, a retardation control agent, and a plasticizer are added to a raw material dope in which a polymer is dissolved in a mixed solvent containing dichloromethane or methyl acetate as a main solvent. Mix to prepare the dope. Next, a dope is cast on a support from a casting die to form a casting film. Then, after the cast film becomes self-supporting on the support, the cast film is peeled off from the support as a wet film, dried, and then wound into a roll form as a product film.

  In general, a TAC film used as a support for photographic light-sensitive materials and optical materials is strictly required to have flatness and slipperiness. For this reason, a method of forming a TAC film by multi-layer casting in which a plurality of dopes with adjusted components are simultaneously cast is often used. The outer layer dope forming the outer layer of the TAC film is mixed with an additive for improving flatness and slipperiness. In addition, additives suitable for various properties of the film are mixed in the base layer dope forming a layer (hereinafter referred to as a base layer) which is a main part of the TAC film. Thereby, the flatness and slipperiness of the surface can be improved without impairing the toughness and flame retardancy of the entire film (see Patent Document 1).

In general, in the solution casting method, as a raw material dope material, in addition to a new polymer and a mixed solvent, a recycled raw material such as a cleaning waste liquid and a recycled chip is used (for example, see Patent Documents 2 and 3). . The cleaning waste liquid is generated when cleaning the dope flow path and the filter of the dope preparation facility. Recycled chips are produced by winding the product film into a roll form (winding misalignment) or by using ear-cutting chips generated during film formation, and crushed into small pieces. ing. In addition, quality rejected products are not suitable as recycled chips, and are excluded from recycled materials.
JP 2003-231137 A JP 2003-236863 A JP 2003-291116 A

  By the way, if the component amount of the raw material dope additive is not constant, characteristic unevenness occurs in the film after film formation. In order to suppress the occurrence of this characteristic unevenness, it is necessary to accurately grasp the component amount of the raw material dope additive. In the said patent document 3, a sample is extract | collected from an ear-cutting chip, the component of this is analyzed, an additive is added in the dope supply line for each layer to a casting die based on this analysis result, It is adjusted to be an additive component. However, when adjusting the amount to be added based on the sampling results from the ear swarf, the accuracy may be increased due to the distance between the additive input position and the sampling collection position and the occurrence of a time lag for the analysis time. There is a problem that it is difficult to make the components of the additive constant, and there is a high possibility that the certain section will be a quality rejected product that does not become a product, resulting in a decrease in production efficiency.

  The present invention is for solving the above-described problems, and provides a solution casting apparatus and method capable of accurately adjusting the amount of additive components in a dope when performing multilayer casting. Objective.

  In the present invention, a dope containing a polymer and a solvent is supplied from a dope supply line to a casting die, and the dope is cast from the casting die onto a traveling support, and n (n is 2 on the support). The above-mentioned natural number) layered film is formed, this n-layered film is dried to have self-supporting property, and then peeled off to form a wet film. The wet film is dried to obtain a polymer film. In a film forming facility, a first dope component amount measuring device provided on the dope supply line immediately before the casting die and measuring the dope component amount online, and a first dope component amount measuring device. On the downstream side, each is provided in a dope supply line for each layer branched by a branch path corresponding to the n-layer casting film, and an additive is introduced into the dope to adjust the amount of the dope component 1st to 1st Based on the measurement results of the dope component amount adjusting device and the first dope component amount measuring device, the dope is adjusted by the first to nth dope component amount adjusting devices so that the dope component amount becomes a target value. And a control device for adjusting the amount of the component.

  A second dope component amount measuring device that is provided on each of the dope supply lines for the respective layers on the downstream side with respect to the first to nth dope component amount adjusting devices and that measures the dope component amount online; It is preferable that the additive input amount of the first to n-th dope component amount adjusting devices is corrected based on the measurement result of the second dope component amount measuring device.

  The first and second dope component amount measuring devices determine the absorbance in the spectral wavelength region having a correlation with the component amount in the dope from the absorbance spectrum obtained by measuring the dope with a near-infrared spectrometer. It is preferable to obtain the dope component amount from the absorbance based on a calibration curve showing the relationship between the dope component amount and the absorbance prepared in advance. Moreover, it is preferable that the raw material of the dope includes an ear dust film and a winding slip film.

  The present invention casts a dope containing a polymer and a solvent from a casting die on a traveling support, and forms a casting film of n (n is a natural number of 2 or more) layers on the support, In the solution casting method for obtaining a polymer film by drying the n-layer casting film so that the film has a self-supporting property and then peeling off to form a wet film, supplying the dope to the casting die The dope component amount is measured by an online first dope component amount measuring device provided in a line, and the deviation from the target value is obtained based on the dope component amount by the first dope component amount measuring device, The first dope supply line is provided downstream of the first dope component amount measuring device so as to be the target value, and is provided in each layer dope supply line branched by a branch path corresponding to the n-layer casting film. 1st to nth door The flop component amount adjusting device, characterized in that by introducing an additive in the dope adjusting the component amount of the dope.

  The component amount of the dope is measured by an online second dope component amount measuring device provided on the downstream side of the first to nth dope component amount adjusting devices, and the dope component by the second dope component amount measuring device It is preferable to correct the additive input amount of the first to nth dope component amount adjusting devices based on the amount.

  The first and second dope component amount measuring devices determine the absorbance in the spectral wavelength region having a correlation with the component amount in the dope from the absorbance spectrum obtained by measuring the dope with a near-infrared spectrometer. It is preferable to obtain the dope component amount from the absorbance based on a calibration curve showing the relationship between the dope component amount and the absorbance prepared in advance.

  In the present invention, the dope component amount is adjusted by the first to n-th dope component amount adjusting devices based on the on-line measurement result by the first dope component amount measuring device. When performing, the dope component amount (additive component amount) can be adjusted with high accuracy without collecting a sample from ear cut waste (ear waste film) or the like. Thereby, generation | occurrence | production of the quality defect product with which the amount of additive components is not constant is suppressed. In addition, the time required for adjusting the component amount of the additive can be significantly shortened. For this reason, it is possible to prevent a certain section of the product film from becoming a rejected product that does not become a product as in the prior art, so that a reduction in production efficiency can be suppressed.

  Since the additive input amount of the first to nth dope component amount adjusting devices is corrected based on the on-line measurement result by the second dope component amount measuring device, the dope component amount (additive component amount) ) Can be adjusted with higher accuracy.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments given here.

[material]
In the present embodiment, cellulose acylate is used as the polymer, and among the cellulose acylates, the substitution degree of the acyl group to the hydroxyl group of cellulose satisfies all of the following formulas (a) to (c). Are preferred, and triacetylcellulose (TAC) is particularly preferred.
(A) 2.5 ≦ A + B ≦ 3.0
(B) 0 ≦ A ≦ 3.0
(C) 0 ≦ B ≦ 2.9
A and B represent the substitution degree of the acyl group with respect to the hydrogen atom in the hydroxyl group in the cellulose, A is the substitution degree of the acetyl group, and B is the substitution degree of the acyl group having 3 to 22 carbon atoms. In addition, it is preferable that 90 mass% or more of TAC is a particle | grain of 0.1-4 mm. The polymer applicable to the present invention need not be limited to cellulose acylate.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with an acyl group having 2 or more carbon atoms. The degree of acyl substitution means the ratio of esterification of the hydroxyl group of cellulose for each of the 2nd, 3rd and 6th positions. However, the degree of substitution 1 is 100% esterification.

  The total degree of acylation substitution, that is, the value of DS2 + DS3 + DS6 is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and particularly preferably 2.40 to 2.88. The DS6 / (DS2 + DS3 + DS6) value is preferably 0.28 or more, more preferably 0.30 or more, and particularly preferably 0.31 to 0.34. DS2 is the ratio at which the hydrogen of the hydroxyl group at the 2-position in the glucose unit is substituted with an acyl group (hereinafter referred to as “the substitution degree of the acyl group at the 2-position”). DS3 is the ratio at which the hydrogen of the hydroxyl group at the 3-position in the glucose unit is substituted with an acyl group (hereinafter referred to as “acyl group substitution degree at the 3-position”). DS6 is the ratio at which the hydrogen of the hydroxyl group at the 6-position in the glucose unit is substituted with an acyl group (hereinafter referred to as “the substitution degree of the acyl group at the 6-position”).

  The acyl group used in the cellulose acylate of the present invention may be only one type or two or more types. When two or more types of acyl groups are used, one of them is preferably an acetyl group. The sum of the degree of substitution of hydroxyl groups at the 2nd, 3rd and 6th positions by acetyl groups is DSA, and the sum of the degree of substitution of the hydroxyl groups at the 2nd, 3rd and 6th positions by acyl groups other than acetyl groups When DSB is DSB, the value of DSA + DSB is preferably 2.22 to 2.90, and particularly preferably 2.40 to 2.88.

  The DSB is preferably 0.30 or more, particularly preferably 0.7 or more. In DSB, 20% or more is preferably the substitution degree of the hydroxyl group at the 6-position, more preferably 25% or more, still more preferably 30% or more, and particularly preferably 33% or more. Further, the DSA + DSB value at the 6-position of the cellulose acylate is 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. By using these cellulose acylates, a solution (dope) having excellent solubility can be prepared. In particular, when a non-chlorine organic solvent is used, a dope having excellent solubility, low viscosity and excellent filterability can be prepared.

  Cellulose, which is a raw material for cellulose acylate, may be obtained from, for example, linter cotton or pulp cotton.

  The acyl group having 2 or more carbon atoms of the cellulose acylate of the present invention may be an aliphatic group or an aryl group and is not particularly limited. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. Preferred examples of these include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, olenoyl, benzoyl, A naphthyl carbonyl, a cinnamoyl group, etc. can be mentioned. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, olenoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable, and propionyl and butanoyl are particularly preferable.

  In the present invention, a compound capable of dissolving cellulose acylate is used as the dope solvent. Examples of the solvent include aromatic hydrocarbons (eg, benzene, toluene, etc.), halogenated hydrocarbons (eg, methylene chloride, chloroform, chlorobenzene, etc.), alcohols (eg, methanol, ethanol, n-propanol, n-butanol, Diethylene glycol, etc.), ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (eg, tetrahydrofuran, methyl cellosolve, etc.). In the present invention, the dope refers to a polymer solution or dispersion obtained by dissolving or dispersing a polymer in a solvent.

  Among these, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. In addition to dichloromethane, one kind of alcohol having 1 to 5 carbon atoms is used from the viewpoint of physical properties such as solubility of TAC, peelability from cast film support, mechanical strength of film, and optical properties of film. It is preferable to mix several kinds. The content of the alcohol is preferably 2% by mass to 25% by mass and more preferably 5% by mass to 20% by mass with respect to the entire solvent. Specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like, but methanol, ethanol, n-butanol or a mixture thereof is preferably used.

  By the way, recently, for the purpose of minimizing the influence on the environment, studies on the use of a solvent composition when dichloromethane is not used are in progress. In this examination, an ether having 4 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, and an alcohol having 1 to 12 carbon atoms are preferably used. Alternatively, these are mixed and used as appropriate. For example, a mixed solvent of methyl acetate, acetone, ethanol, and n-butanol can be mentioned. These ethers, ketones, esters and alcohols may have a cyclic structure. A compound having two or more functional groups of ether, ketone, ester and alcohol (—O—, —CO—, —COO— and —OH) can also be used as the solvent.

  The details of cellulose acylate are described in paragraphs [0140] to [0195] of JP-A-2005-104148. These descriptions can also be applied to the present invention. The dope is mixed with various additives such as an ultraviolet absorber (UV agent), a matting agent, a retardation control agent, and a plasticizer. These additives are also described in paragraphs [0196] to [0516] of JP-A-2005-104148, and these descriptions can also be applied to the present invention.

[Dope production line]
A dope is manufactured using the raw material. As shown in FIG. 1, a dope production line 10 constituting the solution casting apparatus (line) of the present invention prepares a first dope production line 10 a for preparing a raw material dope and three types of dopes described in detail later. The second dope production line 10b.

  The first dope production line 10 a includes a solvent tank 11, a dissolution tank 12, a cleaning waste liquid tank 14, a hopper 15, a heating device 16, a temperature controller 17, and a filtration device 18. The first dope production line 10a is connected to a stock tank 20 (see FIG. 2) provided in the second dope production line 10b.

  A solvent 24 is stored in the solvent tank 11. The solvent 24 is sent to the dissolution tank 12 by opening and closing the valve 25. The cleaning waste liquid tank 14 stores cleaning waste liquid 26 used for cleaning each part of the dope production line 10. As the cleaning liquid used for cleaning, a solvent used for the dope is used. The cleaning liquid is collected after being used for cleaning, and is stored as a cleaning waste liquid 26 in the cleaning waste liquid tank 14. The cleaning waste liquid 26 is sent to the dissolution tank 12 by opening / closing the valve 27.

  A TAC powder (flakes) 28 is accommodated in the hopper 15. The powder 28 is formed from a recycled chip in addition to a new TAC. Here, the reclaimed chip is a TAC (product) film cut-off scrap described later, or a product that is wound with a product roll obtained by winding the TAC film into a roll form (winding product). The powder 28 is added to the dissolution tank 12 while being measured by the hopper 15.

  The dissolution tank 12 includes a jacket 12a that encloses the outer surface thereof, and a first stirrer 30 that is rotated by a motor 29a. Further, a second agitator 31 that is rotated by a motor 29b is attached to the dissolution tank 12. The melting tank 12 is temperature-controlled by flowing a heat transfer medium (not shown) through the jacket 12a. By appropriately selecting and using the types of the first stirrer 30 and the second stirrer 31, the swelling liquid 32 in which the TAC is swollen in the solvent 24 is prepared. The first stirrer 30 is preferably provided with anchor blades, while the second stirrer 31 is preferably a dissolver type eccentric stirrer.

  The swelling liquid 32 prepared in the dissolution tank 12 is sent to the heating device 16 by a pump 34. The heating device 16 includes a pipe with a jacket, and heats the swelling liquid 32. With this heating device 16, the solid content in the swelling liquid 32 is dissolved to prepare the raw material dope 35. In the present specification, a dope before mixing the additive described later is referred to as a raw material dope, and a dope in which an additive is mixed with the raw material dope is referred to as a dope. The raw material dope 35 is sent to the temperature controller 17 and the temperature is adjusted to approximately room temperature.

  The raw material dope 35 whose temperature has been adjusted by the temperature controller 17 is filtered by the filtration device 18. Thereby, impurities contained in the raw material dope 35 are removed. The raw material dope 35 after filtration is sent to the stock tank 20 (see FIG. 2) of the second dope production line 10b.

  As shown in FIG. 2, the second dope production line 10b has a film production line 40 (see FIG. 3) to be described later in order to form a casting film 41 having a three-layer structure by co-casting (multi-layer casting). A total of three types of dopes 43, that is, a base layer dope 43, a support side outer layer dope 44, and an air side outer layer dope 45 are prepared and sent to the film production line 40. Here, the support side outer layer is a layer directly cast on the support (cooling drum 82) of the film production line 40 (see FIG. 3) of the casting film 41, and the air side outer layer is the casting side. The outer layer on the side opposite to the support-side outer layer of the membrane 41 is the outer layer, and the base layer is an intermediate layer between the outer layers.

  The second dope production line 10b includes a stock tank 20, a base layer dope channel (line) 48, a support side outer layer dope channel 49, an air side outer layer dope channel 50, and first to third additions. Agent charging devices 52, 53, and 54 and first to third static mixers 56, 57, and 58 are provided.

  The stock tank 20 includes a jacket 20 a that wraps the outer surface thereof, and a stirrer 61 that is rotated by a motor 60. Although illustration is omitted, a heat transfer medium is caused to flow inside the jacket 20a, whereby the temperature in the stock tank 20 is adjusted to a predetermined temperature. The flow path of the raw material dope 35 fed from the stock tank 20 is branched into the respective dope flow paths 48 to 50. The near-infrared spectrometer provided in the middle of each of the dope channels 48 to 50 will be described in detail later and will not be described here.

  A pump 62 a is connected to the base layer dope channel 48. Then, the raw material dope 35 is fed from the stock tank 20 into the base layer dope channel 48 by the pump 62a. Further, a first additive charging device 52 is connected in the middle of the base layer dope channel 48. The first additive feeding device 52 feeds various additives 63 that impart functionality to the TAC film 70 into the raw material dope 35. Examples of each additive 63 used in the present embodiment include a retardation control agent (optical anisotropy control agent), a plasticizer, and an ultraviolet absorber (UV agent). Each additive 63 is previously dissolved in a solvent or a binder (preferably cellulose acylate). In addition, each additive 63 may be added directly, and the addition method may be appropriately changed according to each additive.

  The first additive charging device 52 is provided with, for example, a plurality of additive tanks 65_1 to 65_n that store each additive 63 separately. Then, by controlling the opening and closing of the valve 66 and the opening amount of each of the tanks 65_1 to 65_n, the input amount of each additive 63 is controlled. Note that the charging control of each additive 63 will be described later and will not be described here. And each additive 63 sent out from the 1st additive injection | throwing-in apparatus 52 is supplied into the raw material dope 35 in the dope flow path 48 for base layers with the pump 67a.

  A first static mixer 56 is provided on the downstream side of the additive introduction position of the base layer dope channel 48. The first static mixer 56 stirs and mixes the raw material dope 35 and each additive 63 added to the raw material dope 35 to prepare the base layer dope 43. The prepared base layer dope 43 is sent to the film production line 40 through the base layer dope channel 48.

  A pump 62b and a second additive feeding device 53 are connected to the support-side outer layer dope channel 49, and a pump 62c and a third additive feeding device 54 are connected to the air-side outer layer dope channel 50. It is connected. The pump 62b sends the raw material dope 35 from the stock tank 20 into the support side outer layer dope channel 49, and the pump 62c sends the raw material dope 35 into the air side outer layer dope channel 50.

  The second and third additive charging devices 53 and 54 are the same as the first additive charging device 52 described above. The second additive feeding device 53 feeds various additives 68 into the raw material dope 35 through the pump 67b, and the third additive feeding device 54 feeds various additives 69 through the pump 67c. The raw material dope 35 is charged. As each additive 68 used in the present embodiment, a peeling accelerator for facilitating peeling of the casting film 41 from a support (cooling drum 82) described later, when the TAC film 70 is wound into a roll shape Examples thereof include matting agents, plasticizers, and UV agents that suppress adhesion between film surfaces. Examples of each additive 69 include a matting agent, a plasticizer, and a UV agent.

  A second static mixer 57 is provided downstream of the support side outer layer dope channel 49 in the additive charging position, and the second static mixer 57 is also provided downstream of the additive side in the air side outer layer dope channel 50. A three static mixer 58 is provided. The second static mixer 57 stirs and mixes the raw material dope 35 and each additive 68 to prepare the support-side outer layer dope 44, and the third static mixer 58 stirs and mixes the raw material dope 35 and each additive 69. Thus, the support-side outer layer dope 44 is prepared.

  The prepared support-side outer layer dope 44 is sent to the film production line 40 through the support-side outer layer dope channel 49. The air side outer layer dope 45 is sent to the film production line 40 through the air side outer layer dope channel 50.

[Film production line]
A method of manufacturing the TAC film 70 by the solution casting method by co-casting using the dopes 43 to 45 for each layer obtained above will be described. As shown in FIG. 3, the film production line 40 includes a casting chamber 71, a pin tenter 72, a clip tenter 73, a drying chamber 74, a cooling chamber 75, and a winding chamber 76.

  In the casting chamber 71, a casting die 80 in which the dope is cast, a feed block 81 attached to the casting die 80 to which the above-described dope channels 56 to 58 are connected, and a cooling that is a support. The drum 82, the peeling roller 85 that peels the casting film 41 from the cooling drum 82, the temperature control device 86 that adjusts the internal temperature of the casting chamber 71, and the volatile solvent that floats inside the casting chamber 71 is liquefied. There are provided a condenser 87 (condenser) to be recovered, a recovery device 88 for recovering the solvent condensed and liquefied by the condenser 87, and a decompression chamber 88 for reducing the pressure around the back of the casting die 80 to a desired pressure. A recovery device 89 that recovers the solvent condensed and liquefied by the condenser 87 is provided outside the casting chamber 71. Note that the solvent recovered by the recovery device 89 may be reused as the raw material of the raw material dope 35 described above.

  The dopes 43 to 45 (see FIG. 2) for each layer are fed into the feed block 81 while being adjusted to have a desired flow rate. Then, the dopes 43 to 45 for each layer are merged in the feed block 81 and then simultaneously co-cast from the casting die 80 onto the cooling drum 82 (simultaneous lamination co-casting). As a result, a three-layer casting film 41 is formed on the cooling drum 82.

  The cooling drum 82 is rotated by a driving device (not shown). A cooling medium supply device 90 is attached to the cooling drum 82 in order to maintain the surface temperature at a desired temperature. The refrigerant adjusted to a predetermined temperature is supplied from the refrigerant supply device 90 to the inside of the cooling drum 82, and is circulated and passed. Thereby, the cast dope is cooled and gelled to form the cast film 41. Then, after the gelation of the casting film 41 is promoted to become self-supporting, the casting film 41 is peeled off from the cooling drum 82 by the peeling roller 85 to form a wet film 92.

  A plurality of pass rollers 94 are provided between the casting chamber 71 and the pin tenter 72. The pass roller 94 guides the wet film 92 to the pin tenter 72. Although not shown, a dry air supply device is provided above the pass roller 94, and the dry air is applied to the wet film 92 on the pass roller 94 from the dry air supply device to dry the wet film 92. .

  The pin tenter 72 has a plurality of pins (not shown), and pierces the both side edges of the wet film 92 to transport the wet film 92. In addition, the wet film 92 is dried in the pin tenter 72 to reduce the amount of residual solvent, so that the wet film 92 becomes a TAC (product) film 70. The clip tenter 73 is provided downstream of the pin tenter 72, grips both side edges of the TAC film 70 coming out of the pin tenter 72, conveys the TAC film 70, and dries the TAC film 70.

  An ear clip device 97 is provided downstream of the clip tenter 73. The ear clip device 97 cuts both side edges (ear parts) of the TAC film 70. The cut off ear chips (ear waste film) are finely cut by the crusher 97a to form the above-mentioned recycled chip. After the recovered chip is collected, it is processed into a TAC powder 28 and reused as a recycled material. Then, the TAC film 70 from which the ear portion has been cut is sent to the drying chamber 74 on the downstream side of the ear clip device 97.

  The drying chamber 74 is provided with a number of rollers 98. In the drying chamber 74, the TAC film 70 is dried while being conveyed by a roller 98. In addition, the solvent gas generated from the TAC film 70 in the drying chamber 74 is adsorbed and recovered by an adsorption recovery device 99 provided outside the drying chamber 74.

  The TAC film 70 exiting from the drying chamber 74 is sent to the cooling chamber 75 and is cooled to approximately room temperature in the cooling chamber 75. Downstream of the cooling chamber 75, a forced static elimination device 100 (static elimination bar) that adjusts the charged voltage of the TAC film 70 to a predetermined range (for example, −3 kV to +3 kV) is provided. On the downstream side thereof, a knurling application roller 101 for applying embossing knurling to both edges of the TAC film 70 is provided.

  The TAC film 70 provided with the knurling is wound up by the winding roller 103 in the winding chamber 76. A press roller 105 that controls the tension on the TAC film 70 is provided in the vicinity of the winding roller 103. Then, the winding misalignment product in which the winding misalignment occurred during the winding is cut into chips finely like the above-mentioned ear-cut scraps, and then processed into the TAC powder 28, and the material of the raw material dope 35 Used as

  As described above, the obtained TAC film 70 can be used for a film support for a photographic photosensitive material, a protective film for a polarizing plate of a liquid crystal display device, and the like.

[Additive control method]
Next, with reference to FIGS. 2 and 4, the additives 63, 68, 69 by the first to third additive charging devices 52 to 54 corresponding to the first to nth dope component amount adjusting devices of the present invention. The charging control will be described. The charging control of each additive charging device 52 to 54 is basically the same. Therefore, here, the charging control of each additive 63 by the first additive charging device 52 will be described as a specific example. Do.

  In the present embodiment, the component amount of the material dope 35 (particularly each additive 63) formed by using a part of the recycled material (cleaning waste liquid 26 and regenerated chip) at the upstream side of the input position of each additive 63 first. Based on the measurement result, the first correction addition amount of each additive 63 is determined so that the component amount of the base layer dope 43 (each additive 63) becomes a target value, and the addition of each additive 63 is performed. I do. Next, on the downstream side of the first static mixer 56, the component amount of each additive 63 contained in the base layer dope 43 into which each additive 63 has been charged and mixed with the previously determined correction addition amount is measured. The first correction addition amount is corrected based on the measurement result.

  Of the additives 63 (retardation control agent, plasticizer, UV agent) charged into the base layer dope 43, the amount of UV agent charged is very small. For this reason, in this embodiment, the control of the input amount of the UV agent is not performed, and only the control of the input amount of the retardation control agent and the plasticizer (hereinafter referred to as both agents as required) is performed.

  The component amounts of the raw material dope 35 and the base layer dope 43 are measured using a known near infrared spectroscopy. Near-infrared spectroscopic analysis method irradiates a measurement object (dope) with near-infrared light in a short wavelength region, and uses an optical sensor to measure measurement light such as scattered reflected light, scattered transmitted light or transmitted reflected light from the measured object. By detecting the absorbance spectrum of the measurement object by detection, the absorbance in the spectral wavelength region having a correlation inherent to the component amount of the raw material dope 35 and the base layer dope 43 is obtained, and the absorbance is based on a calibration curve prepared in advance. From this, the component amounts of the raw material dope 35 and the base layer dope 43 are calculated. Since the retardation control agent and plasticizer used in the production of the TAC film 70 have an amide bond, the amount of components can be measured without any problem by near infrared spectroscopy.

  For the above-described measurement of the absorbance spectrum, a Fourier transform type near-infrared spectrometer (hereinafter simply referred to as a near-infrared spectrometer) is used. As this near-infrared spectrometer, “InfraSpec NR800” manufactured by Yokogawa Electric Corporation is used in this embodiment. In this embodiment, the first near-infrared spectrometer 110 is provided between the stock tank 20 and the branch points of the dope channels 48 to 50, and the first static mixer 56 and the film production line 40 are connected. A second near-infrared spectrometer 112 is provided between them. The absorbance spectrum data obtained by the first near-infrared spectroscopic analysis 110 will be described later by providing the first near-infrared spectroscopic analysis 110 on the upstream side of the branch point of each of the dope channels 48 to 50. It can also be used for the charging control of the second and third additive charging devices 53 and 54.

  Both near-infrared spectrometers 110 and 112 perform Fourier transform on the measurement light obtained from a probe (not shown) inserted into a flow path through which the raw material dope 35 and the base layer dope 43 circulate, thereby obtaining an absorbance spectrum ( (See FIG. 5). Thereby, online measurement of the raw material dope 35 and the base layer dope 43 becomes possible.

  When the raw material dope 35 passes through the first near-infrared spectrometer 110, the absorbance spectrum data measured by the first near-infrared spectrometer 110 once every second, for example, is stored in the main controller 114 (see FIG. 4). ) Is input to the data processing unit 116. The main controller 114 includes a data processing unit 116, an addition amount determination unit 118, a memory 120, an input control unit 122, and the like, and controls each unit of the dope production line 10.

FIG. 5 shows an example of the absorbance spectrum. The absorbance peak (peak intensity) in the spectral wavelength range (wave number range) indicated by A in the figure has a correlation with the component amount (mass%) of cellulose, which is the raw material of TAC contained in the dope, and the solvent 24. . The peak intensity in the spectral wavelength region indicated by B in the figure has a correlation with the component amount of moisture (H ₂ O) contained in the dope. The peak intensity in the spectral wavelength region indicated by C in the figure has a correlation with the amount of the component of the retardation control agent contained in the dope. The peak intensity in the spectral wavelength region indicated by D in the figure has a correlation with the amount of the plasticizer component contained in the dope.

  As shown in FIG. 3, when the absorbance spectrum data is input from the first near-infrared spectrometer 110, the data processing unit 116 has a peak intensity in a spectral wavelength range that is correlated with the component amounts of the retardation control agent and the plasticizer. Ask for. Next, the data processing unit 116 searches the calibration curve for the retardation control agent and the calibration curve for the plasticizer stored in the calibration curve database 124. In the calibration curve database 124, calibration curves of measured objects (each additive 63, 68, 69, etc.) for measuring the component amount are stored in advance.

  FIG. 5 shows an example of a calibration curve. The calibration curve associates the absorbance (peak intensity) of the measurement object with the component amount. This calibration curve is created based on absorbance spectrum data obtained by measuring a measurement object with a known component amount. Then, the component amount can be calculated by substituting the peak intensity obtained from the absorbance spectrum data into the calibration curve.

  Therefore, as shown in FIG. 3, the data processing unit 116 substitutes the peak intensity of the retardation control agent and the plasticizer into the corresponding calibration curve in the calibration curve database 124 and calculates the respective component amounts. That is, in the present embodiment, the data processing unit 116 and the near-infrared spectrometers 110 and 112 (128, 130) constitute the first and second dope component amount measuring apparatuses of the present invention. Thus, the component amounts of both agents contained in the raw material dope 35 are obtained. At this time, the component amounts of TAC, solvent, and water contained in the raw material dope 35 may be obtained simultaneously by the same procedure. Then, the calculation result of the component amount obtained by the data processing unit 116 is input to the addition amount determining unit 118.

  The addition amount determination unit 118 constitutes a control device of the present invention together with an addition control unit 112 described later. This addition amount determination unit 11 inputs the raw material dope 35 based on the difference between the calculation result of the retardation control agent and the plasticizer component amount and the target value of the component amount of both agents determined for each type of TAC film 70 The first correction addition amount of each additive 63 to be determined is determined. The target values of the component amounts of both agents can be freely set by an operator via an operation panel (not shown). In addition, when determining the 1st correction addition amount of each additive 63, the 1st correction addition amount of each additive 63 is considered, considering the component amount of TAC, a solvent, and a water | moisture content contained in the raw material dope 35 as needed. May be determined. Then, the determined first corrected addition amount data of each additive 63 is stored in the memory 120.

  The first correction addition amount of each additive 63 (retardation control agent and plasticizer) stored in the memory 120 is read by the input control unit 122 that controls the respective additive input devices 52 to 54. The charging control unit 122 is configured so that both agents are charged by the first correction addition amount at the timing when the raw material dope 35 measured by the first near-infrared spectrometer 110 passes through the first additive charging device 52. In addition, the first additive charging device 52 is controlled. Specifically, as described above, the first correction of both agents is performed by controlling the opening / closing and opening amount of the valve 66 of the tank in which both agents are stored in each of the additive tanks 65_1 to 65_n (see FIG. 2). The added amount is added to the raw material dope 35. In addition, the method of adjusting the input amount of each additive 63 containing both agents is not limited to this, and various methods may be used.

  The UV agent is charged in a predetermined amount as described above. In addition, before adding each additive 63 to the raw material dope 35, each additive 63 may be mixed.

  As described above, the base material dope 43 is prepared by stirring and mixing the raw material dope 35 into which each additive 63 is added in the first static mixer 56. The prepared base layer dope 43 passes through the second near-infrared spectrometer 112. Similarly, the absorbance spectrum data measured by the second near-infrared spectrometer 112 is input to the data processing unit 116.

  When the absorbance spectrum data is input from the second near-infrared spectrometer 112, the data processing unit 116 similarly calculates the component amounts of the retardation control agent and the plasticizer contained in the base layer dope 43. Then, the addition amount determination unit 118 determines whether or not the calculation results of the component amounts of the new retardation control agent and plasticizer have reached the target values described above. If the target value has not been reached, a correction coefficient (for example, 0.95, 0.93, 1.02) for correcting to reach the target value of the component amounts of both agents is added to the added amount determining unit 118. The first correction addition amount is corrected by obtaining 118a and multiplying the first correction addition amount by this correction coefficient. The corrected first correction addition amount data is overwritten on the first correction addition amount data previously stored in the memory 120.

  The charging control unit 122 controls the first additive charging device 52 as described above based on the corrected first corrected addition amount data read from the memory 120. Thereby, since the retardation control agent and the plasticizer are added to the raw material dope 35 by the corrected first corrected addition amount, the component amounts of both agents can be made closer to the target values.

  The charging control by the second and third additive charging devices 53 and 54 is simultaneously performed by the same method as the charging control by the first additive charging device 52 as described above. For this reason, a third near-infrared spectrometer 128 is provided between the second static mixer 57 and the film production line 40, and a fourth between the third static mixer 58 and the film production line 40. A near-infrared spectroscopic analysis 130 is provided (see FIG. 2).

  As described above, based on the absorbance spectrum data output from the first near-infrared spectrometer 110, the data processing unit 116 converts the peak intensities of the additives 68 and 69 to the corresponding calibration curve in the calibration curve database 124. By substituting, the component amounts of the additives 68 and 69 are calculated. For each additive 68 (exfoliation accelerator, matting agent, plasticizer, UV agent, etc.) and each additive 69 (matting agent, plasticizer, UV agent, etc.), the amount of input is small, A predetermined amount may be input without controlling the input amount.

  Similarly, the addition amount determination unit 118 determines a second correction addition amount to be added to each additive 68 based on the difference between the calculation result of the component amount of each additive 68 and 69 and the target value, A third correction addition amount for adding the additive 69 is determined. These second and third correction addition amount data are stored in the memory 120 together with the first correction addition amount data described above.

  Next, the charging control unit 122 controls the second additive charging device 53 so that each additive 68 is charged for the second corrected additive amount, and each additive 69 is charged for the third corrected additive amount. As a result, the third additive charging device 54 is controlled. Thereby, each additive 68 and the raw material dope 35 are stirred and mixed by the second static mixer 57 to prepare the support-side outer layer dope 44, and each additive 69 and the raw material dope 35 are mixed with the third static mixer 58. The air-side outer layer dope 45 is prepared by stirring and mixing.

  When the prepared support-side outer layer dope 44 passes through the third near-infrared spectrometer 128 and the air-side outer layer dope 45 passes through the fourth near-infrared spectrometer 130, both near-infrared spectrometers The absorbance spectrum data measured at 128 and 130 is input to the data processing unit 116, and the component amounts of the new additives 68 and 69 are obtained. Next, when the component amounts of the additives 68 and 69 do not reach the target values, the addition amount correction unit 118a of the addition amount determination unit 118 multiplies the second and third correction addition amounts by the correction coefficient, The second and third correction addition amounts are corrected. The corrected second and third correction addition amount data are overwritten on the second and third correction addition amount data previously stored in the memory 120.

  The charging control unit 122 controls the second and third additive charging devices 53 and 54 based on the corrected second and third corrected addition amounts, and is measured by the first near-infrared spectrometer 110. At the timing when the raw material dope 35 passes through the second and third additive feeding devices 53 and 54, the respective additives 68 and 69 are fed into the raw material dope 35. Thereby, the component amount of each additive 68 contained in the support-side outer layer dope 44 and the component amount of each additive 69 contained in the air-side outer layer dope 45 can be made closer to the target values. Hereinafter, the component amounts of the additives 63, 68, and 69 are measured and charged in accordance with the timing at which the dopes 35 and 43 to 45 pass through the devices and apparatuses, and the first to third correction addition amounts are corrected.

  It should be noted that the additive is added to the dope 43 to 45 for each layer that has passed through the second to fourth near-infrared spectrometers 112, 128, and 130 (first to third additive feeding devices 52 to 54) before correction. The component amount cannot be finely adjusted. For this reason, the component amount of each layer dope 43 to 45 (each additive 63, 68, 69) is stored in the memory 120 or the like, and later when a film failure occurs in the TAC film (product film) 70, The correspondence relationship between the dopes 43 to 45 for each layer and the TAC film 70 will be seen. The correspondence between the dope 43 to 45 for each layer and the TAC film 70 is that the length of each process is known, so that the process of the dope 43 to 45 for each layer passing through each process to become the TAC film 70 is simulated. Based on the simulation result, the correspondence between the dopes 43 to 45 for each layer and the TAC film 70 can be known. Accordingly, the amount of the dope (additive) component at each position of the TAC film 70 can be known, and can be used as an element for pursuing the cause of failure.

  Next, the flow of charging control of the first to third additive charging devices 52 to 54 in the dope production line 10 will be described with reference to FIG. When the operation of the dope production line 10 is started, the solvent 24, the cleaning waste liquid 26, and the TAC powder 28 are mixed in the dissolution tank 12 to prepare the swelling liquid 32. The swelling liquid 32 is sent to the heating device 16 and heated. Thereby, the solid content in the swelling liquid 32 is dissolved and the raw material dope 35 is prepared. The prepared raw material dope 35 is adjusted to a temperature of about room temperature by the temperature controller 17 and then sent to the stock tank 20 (see FIG. 2).

  When a predetermined amount of the raw material dope 35 is stored in the stock tank 20, the pumps 62a to 62c are operated to feed the raw material dope 35 to the dope channels 48 to 50, respectively. At this time, the absorbance spectrum data of the raw material dope 35 measured by the first near-infrared spectrometer 110 is input to the data processing unit 116 of the main controller 114. The data processing unit 116 obtains peak intensities (see FIG. 5) in the spectral wavelength range that correlates with the individual component amounts of the additives 63, 68, and 69, and these peak intensities correspond to the calibration curve database 124. Substituting into the calibration curve (see FIG. 6), the component amounts of the additives 63, 68, and 69 are obtained.

  The component amounts of the additives 63, 68 and 69 calculated by the data processing unit 116 are input to the addition amount determination unit 118. The addition amount determination unit 118 determines the first to third correction addition amounts to which the respective additives 63, 68, and 69 are respectively added based on the difference between the calculation result of each component amount and the target value. The determined first to third correction addition amount data is stored in the memory 120.

  The input control unit 122 reads the first to third correction addition amount data stored in the memory 120, and the raw material dope 35 measured by the first near-infrared spectrometer 110 is the first to third additives, respectively. At the timing of passing through the charging devices 52 to 54, the first additive charging device 52 is controlled such that each additive 63 is charged by the first correction addition amount, and each additive 68 is equal to the second correction addition amount. The second additive feeding device 53 is controlled so that only the third correction addition amount is fed, and the third additive feeding device 54 is controlled so that each additive 69 is fed by the third corrected addition amount. As a result, the additives 63, 68, and 69 are introduced into the raw material dope 35 flowing through the dope channels 48 to 50 by the determined first to third correction addition amounts, respectively.

  The raw material dope 35 into which the additives 63 are introduced in the base layer dope channel 48 is stirred and mixed by the first static mixer 58 to prepare the base layer dope 43. The raw material dope 35 into which the additives 68 are introduced in the support side outer layer dope channel 49 is stirred and mixed by the second static mixer 57 to prepare the support side outer layer dope 44. In addition, the raw material dope 35 into which each additive 69 is charged in the air side outer layer dope flow path 50 is stirred and mixed by the third static mixer 58 to prepare the air side outer layer dope 45.

  The prepared dopes 43 to 45 for the respective layers pass through the second to fourth near-infrared spectrometers 112, 128, and 130, respectively. As a result, the absorbance spectrum data measured by the second to fourth near-infrared spectrometers 112, 128, and 130 is input to the data processing unit 116. Similarly, the data processing unit 116 calculates the component amounts of the additives 63, 68, and 69 contained in the dope 43 to 45 for each layer based on each absorbance spectrum data. As described above, these component amounts are stored in the memory 120 or the like so that the component amounts of the dopes 43 to 45 (each additive 63, 68, 69) for each layer at each position of the TAC film 70 can be known. Remember.

  Next, the addition amount determination unit 118 determines whether or not the calculation results of the component amounts of the new additives 63, 68, and 69 have reached the target value described above. If the target value has not been reached, the addition amount correction unit 118a corrects the first to third correction addition amounts by multiplying the first to third correction addition amounts by the correction coefficient. The corrected first to third correction addition amount data are overwritten on the first to third correction addition amount data previously stored in the memory 120.

  The charging control unit 122 reads the corrected first to third correction addition amount data newly stored in the memory 120 so that each additive 63 is charged by the corrected first correction addition amount. The first additive feeding device 52 is controlled, and the second additive feeding device 53 is controlled so that each additive 68 is fed by the corrected second corrected addition amount, and each additive 69 is corrected. The third additive charging device 54 is controlled so as to be charged for the third correction addition amount. As a result, the additives 63, 68, and 69 are introduced into the raw material dope 35 flowing through the dope channels 48 to 50 by the determined first to third final input amounts, respectively.

  As described above, in this embodiment, when preparing the TAC film 70 using the solution casting method by co-casting (multi-layer casting) by preparing three types of dopes 43 to 45 for each layer, the near infrared is used. By using the spectroscopic analysis method, the component amounts of the additives 63, 68, and 69 contained in the raw material dope 35 and the dopes 43 to 45 for each layer are measured on-line. 54, the amount of each additive 63, 68, 69 introduced into the raw material dope 35 can be adjusted.

  Conventionally, a sample is collected from the ear swarf and the amount of each additive 63, 68, 69 is adjusted based on the analysis result of analyzing the components thereof. It is difficult to make the components of the additive constant with high accuracy due to the fact that they are separated from each other and the time lag corresponding to the analysis time has occurred. On the other hand, in the present embodiment, since the amount of each additive 63, 68, 69 can be adjusted without taking a sample from the ear swarf, the quality of the additive component amount is not constant. It can be suppressed. In addition, the time required for adjusting the component amounts of the additives 63, 68, and 69 can be greatly shortened. For this reason, since it can also prevent that it becomes the quality rejection product which does not become a product in a fixed area like the past, it can suppress a production efficiency fall.

  Moreover, in this embodiment, each addition is based on the measurement result by the 2nd-4th near-infrared spectrometer 112,128,130 provided in the downstream of the 1st-3rd additive injection | throwing-in apparatus 52-54. Since the first to third correction addition amounts are corrected when the component amounts of the additives 63, 68, 69 do not reach the target value, the component amounts of the additives 63, 68, 69 are further set to the target values. Can be approached.

  In the above embodiment, the first near-infrared spectrometer 110 is provided on the upstream side of the branch point of each of the dope channels 48 to 50, and the second to fourth sides are provided on the downstream side of the static mixers 56 to 58, respectively. Although the near-infrared spectrometer 112, 128, and 130 are provided, the present invention is not limited to this. For example, based on the measurement results of only one of the first near-infrared spectrometer 110 or the second to fourth near-infrared spectrometers 112, 128, and 130, the additives 63, 68, and 69 are charged. The amount may be adjusted. In this case, the deviation between the component amount of each additive 63, 68, 69 contained in each layer dope 43 to 45 and the target value increases, but the number of near infrared spectrometers decreases, so the line Configuration is simplified.

  Moreover, in the said embodiment, based on the absorbance spectrum data measured by each near-infrared spectrometer 110,112,128,130, the amount of components of a retardation control agent and a plasticizer in the data processing part 116 in the main controller 114 is shown. However, the present invention is not limited to this. For example, when the near-infrared spectrometer is of a type that stores a calibration curve, the component amount data of the retardation control agent and the plasticizer are directly input to the addition amount determination unit 118 of the main controller 114. Also good. Further, instead of providing four near-infrared spectrometers, a near-infrared spectrometer having four measurement probes and capable of multichannel measurement may be provided.

  In the above embodiment, the second to fourth near-infrared spectrometers 112, 128, and 130 (each additive charging device 52 to 54) are passed before the first to third correction addition amounts are corrected. Although fine adjustment of the component amount of each additive 63, 68, 69 cannot be performed with respect to the dopes 43 to 45 for each layer, the present invention is not limited to this. For example, an additive charging device and a static mixer are provided on the downstream side of the second to fourth near-infrared spectrometers 112, 128, and 130, respectively, to further finely adjust the component amounts of the additives 63, 68, and 69. May be performed.

  In the above-described embodiment, the component amounts of the additives 63, 68, and 69 are measured and charged in accordance with the timing when the raw material dope 35 and the dopes 43 to 45 for each layer pass through the respective devices and apparatuses, and the first to third corrections. Although the amount of addition is corrected, etc., when the component change of each of the dopes 35, 43 to 45 is small, the amount of each component 63, 68, 69 is measured and charged, and the amount of correction added is corrected. It may be performed at an appropriate timing.

  In addition, the amount of each additive 63, 68, 69 that can be charged by each additive charging device 52-54 is affected by the performance of the first to third static mixers 57-58. For this reason, when the first to third correction addition amounts do not fall within the range that can be charged by the additive charging devices 52 to 54, the additives 63 and 68 are prepared in the preparation stage of the raw material dope 35 and the subsequent transfer stage. , 69 may be added in advance in an appropriate amount.

  Moreover, in the said embodiment, the component amount of TAC, a solvent, and a water | moisture content contained in the raw material dope 35 is simultaneously computable from the absorbance spectrum data output from the 1st near-infrared spectrometer 110. FIG. For this reason, the input amounts of the solvent 24, the cleaning waste liquid 26, and the powder 28 to be charged into the dissolution tank 12 may be adjusted based on these calculation results.

  In the above embodiment, the cleaning waste liquid 28 and the recycled chip are used as the raw material of the raw material dope 35, but only one of them may be used.

  Moreover, each additive charging device 52-54 of the said embodiment is provided with several additive tank 65_1-65_n according to the kind of each additive 63,68,69 used, but this invention is this. However, the present invention is not limited thereto, and an additive charging device of a type in which each additive 63 is dissolved in one additive tank and then charged into the raw material dope 35 may be used.

  Moreover, in the film production line 40 of the said embodiment, after carrying out the dope 43-45 for each layer inside the feed block 81, the simultaneous lamination co-casting which co-casts simultaneously from the casting die 80 on the cooling drum 82 is performed. However, the present invention is not limited to this. For example, three casting dies may be arranged side by side along the circumferential direction of the cooling drum 82, and the dopes 43 to 45 for each layer may be sequentially laminated and cast from each casting die.

  In the above embodiment, the casting film 41 having a three-layer structure is formed. However, the present invention is not limited to this, and an arbitrary n-layer (n is a natural number of 2 or more) structure. A cast film may be formed. In the above embodiment, the cooling drum 82 is used as a support for casting the dope, but the present invention is not limited to this, and a casting band stretched between a pair of rotating rollers is used. It may be used as a support.

  Although not described in the above embodiment, when the type of the TAC film 70 manufactured in the dope manufacturing line 10 and the film manufacturing line 40 is switched, the operator selects each additive 63 corresponding to the new TAC film 70, The components 68 and 69 and the target values of the component amounts are input via an operation panel (not shown). Thereby, each additive 63, 68 by each additive injection | throwing-in apparatus 52-54 so that the component amount of each additive 63, 68, 69 contained in each dope 43-45 for each layer may reach a new target value. The input amount of 69 is adjusted. At this time, since the production of the TAC film 70 is continuously performed without stopping the line, when the components of the additives 63, 68, and 69 and the amount of the components are switched, the TAC film 70 differs depending on the additive charging devices 52 to 54. You may make it add a kind of marker agent simultaneously.

  The marker agent need not have an adverse effect on film formation, and may be any one that can be easily detected when the TAC film 70 is obtained. You may make it detect a marker agent using a detection apparatus other than visual confirmation. In addition to using a unique marker agent, a specific additive may be increased or decreased only for that portion, and this increased or decreased portion may be used as a marker. Further, this marker agent may be added simultaneously when the additive is added based on the corrected first to third addition correction amounts. Thereby, the correspondence relationship between the dope 43 to 45 for each layer adjusted based on the corrected first to third correction addition amounts and the TAC film 70 can be accurately grasped.

  In the above embodiment, the addition amount correction unit 118a of the addition amount determination unit 118 corrects each correction addition amount by multiplying each of the first to third correction addition amounts by the correction coefficient. Is not limited to this, and each correction addition amount is corrected by adding (subtracting) a correction value that is corrected to reach the target value of the component amount of the additives 63, 68, and 69 to each correction addition amount. May be performed.

  Moreover, in the said embodiment, the 1st-3rd correction addition amount of each additive 63,68,69 is determined based on the measurement result of the 1st near-infrared spectrometer 110, Furthermore, the 2nd-4th near Although the first to third correction addition amounts are corrected based on the measurement results obtained by the infrared spectroscopic analysis 112, 128, 130, the present invention is not limited to this. Various adjustment methods are used as long as the component amounts of the additives 63, 68, and 69 in the dopes 43 to 45 for each layer can be accurately adjusted based on the measurement results of the near-infrared spectrometers 110, 112, 128, and 130. You may do it.

  In the above embodiment, the dope production line 10 and the film production line 40 for producing the TAC film 70 have been described as examples. However, the present invention is not limited to this, and various polymers are used. The present invention can be applied to equipment for manufacturing a film using a solution casting method by co-casting.

It is the schematic of a 1st dope manufacturing line. It is the schematic of a 2nd dope production line. It is the schematic of a film production line. It is a block diagram which shows the electric constitution of the main controller of a dope production line. It is the graph which showed an example of the absorbance spectrum. It is the graph which showed an example of the calibration curve. It is a flowchart of the injection control of an additive.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dope production line 10a 1st dope production line 10b 2nd dope production line 24 Solvent 26 Cleaning waste liquid 28 Powder 35 Raw material dope 40 Film production line 41 Casting film 43 Base layer dope 44 Support side outer layer dope 45 Air side outer layer Dope 48 Dope channel for base layer 49 Dope channel for support side outer layer 50 Dope channel for air side outer layer 52 First additive feeding device 53 Second additive feeding device 54 Third additive feeding device 80 Casting die 82 Cooling Drum 110 First near-infrared spectrometer 112 Second near-infrared spectrometer 114 Main controller 116 Data processing unit 118 Addition determination unit 122 Input control unit 124 Calibration curve database 128 Third near-infrared spectrometer 130 130 4 near-infrared spectrometer

Claims (7)

A dope containing a polymer and a solvent is supplied from a dope supply line to a casting die, and the dope is cast from the casting die onto a traveling support, and n (n is a natural number of 2 or more) on the support. In a solution casting apparatus for forming a layer casting film, drying this n-layer casting film to give it a self-supporting property, and then peeling it off to form a wet film, and drying the wet film to obtain a polymer film. ,
A first dope component amount measuring device which is provided in the dope supply line immediately before the casting die and measures the component amount of the dope online;
Provided in the dope supply line for each layer, which is downstream of the first dope component amount measuring device and branched by a branch path corresponding to the n-layer casting film, and an additive is introduced into the dope A first to n-th dope component amount adjusting device for adjusting the dope component amount;
A control device that adjusts the dope component amount by the first to n-th dope component amount adjusting devices so that the dope component amount becomes a target value based on the measurement result of the first dope component amount measuring device. A solution casting apparatus characterized by comprising:   A second dope component amount measuring device that is provided on each of the dope supply lines for the respective layers on the downstream side with respect to the first to nth dope component amount adjusting devices and that measures the dope component amount online; 2. The solution casting apparatus according to claim 1, wherein an additive input amount of the first to n-th dope component amount adjusting devices is corrected based on a measurement result of the second dope component amount measuring device.   The first and second dope component amount measuring devices determine the absorbance in the spectral wavelength region having a correlation with the component amount in the dope from the absorbance spectrum obtained by measuring the dope with a near-infrared spectrometer. 3. The solution casting apparatus according to claim 2, wherein the amount of the dope component is obtained from the absorbance based on a calibration curve indicating a relationship between the amount of the dope component and the absorbance prepared in advance.   The solution casting apparatus according to any one of claims 1 to 3, wherein the dope material includes an ear dust film and a winding slip film. A dope containing a polymer and a solvent is cast from a casting die on a traveling support to form a casting film of n layers (n is a natural number of 2 or more) on the support. In the solution casting method in which the film is dried to have a self-supporting property and then peeled off to form a wet film, and the wet film is dried to obtain a polymer film.
The dope component amount is measured by an on-line first dope component amount measuring device provided in the dope supply line to the casting die,
Based on the component amount of the dope by the first dope component amount measuring device, to determine the amount of deviation from the target value,
The first dope supply line is provided downstream of the first dope component amount measuring device so as to be the target value, and is provided in each layer dope supply line branched by a branch path corresponding to the n-layer casting film. A solution film-forming method characterized in that an additive is introduced into the dope to adjust the component amount of the dope by a 1 to n-th dope component amount adjusting device.   The component amount of the dope is measured by an online second dope component amount measuring device provided on the downstream side of the first to nth dope component amount adjusting devices, and the dope component by the second dope component amount measuring device 6. The solution casting method according to claim 5, wherein the additive input amount of the first to nth dope component amount adjusting devices is corrected based on the amount.   The first and second dope component amount measuring devices determine the absorbance in the spectral wavelength region having a correlation with the component amount in the dope from the absorbance spectrum obtained by measuring the dope with a near-infrared spectrometer. The solution casting method according to claim 6, wherein the dope component amount is obtained from the absorbance based on a calibration curve indicating a relationship between the dope component amount and the absorbance prepared in advance.

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