JP2014055277A - Polymer purifying method, solution film forming method, equipment, and deposited polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a polymer solution having a small content of foreign matters.SOLUTION: A raw material cellulose acylate (raw material CA) 17 is dissolved in methylene chloride 18 in a dissolution tank 6 to produce a dilute dope 21 having a polymer concentration of 7 mass%. The dilute dope 21 is filtrated through a filter 12. Hot water heated and kept at a temperature not lower than a boiling point of the methylene chloride 18 is fed into a deposition device 8. The dilute dope 21 is sprayed toward a hot water surface in the deposition device 8 from a first nozzle 25. The methylene chloride 18 in the dilute dope 21 contacted with the hot water is vaporized to deposit cellulose acylate 30. The deposited cellulose acylate (deposited CA) 30 is taken out form the water surface and the contained hot water 22 is removed. Thereafter, the deposited CA30 is dried with a vibration dryer 10. The deposited CA30 excellent in dissolubility in solvent can be obtained since the deposited CA30 is obtained from the dilute dope 21 which is once dissolved in solvent.

Description

  The present invention relates to a polymer purification method, a solution casting method, equipment, and a precipitated polymer.

  A thermoplastic film having light permeability is lightweight and easy to mold, and thus is widely used as an optical film. Among them, cellulose acylate films using cellulose acylate and the like are optical films (for example, retardation films and polarizing plates) that are constituent members of liquid crystal display devices whose market is expanding in recent years including photographic photosensitive films. Used in protective films and the like.

  Such a film is produced by a solution casting method. In the solution casting method, a casting solution is formed by flowing a polymer solution (casting dope) containing a polymer and a solvent on a support. Next, after the cast film becomes transportable, it is peeled from the support to form a wet film. Then, this wet film is sent to the drying chamber. In the drying chamber, while the wet film is wound around a roller and conveyed, the solvent is evaporated from the wet film to form a film.

  When the above film is used as an optical film, foreign matter failure has occurred with the recent high definition of liquid crystal displays (LCDs) and the spread of mobile terminal devices such as smartphones (multifunction mobile phones) and tablet computers. Less is required.

  For example, Patent Document 1 discloses a method for reducing the foreign matter by filtering and drying the cellulose acylate solution and then drying. In addition, Patent Document 2 includes a step of mixing a cellulose acylate solution and an alcohol, and further mixing with a poor solvent to precipitate cellulose acylate, and an organic solvent used when preparing the cellulose acylate solution. A method for producing cellulose acylate is disclosed in which the SP value, which is the solubility parameter, is set in the range of 18.5 to 25.0 to reduce the content of foreign matter.

  In addition, various types of optical films having different characteristics are required as LCDs have higher definition and mobile terminal devices have become popular. When changing the characteristics, the kind of additive liquid and the blending ratio thereof are changed, or the raw material polymer is changed. In the case of a raw material polymer, the optical properties and other characteristics change slightly depending on the origin of the raw material, for example, in the case of cellulose acylate, the difference in cellulose as the raw material obtained from pulp and cotton, and the difference in the production area. I know you will.

  In Patent Document 3, a reference dope including a polymer and a solvent is made, and an additive liquid specific to each type is added to the reference dope immediately before the casting die. Then, when the film type is switched, the additive solution is changed according to the type. Thereby, when producing films of different varieties, production time and product loss are suppressed without increasing the cost of manufacturing equipment.

JP 2008-56819 A JP 2012-25896 A JP 2010-100042 A

  In the thing of patent document 1, 2, the impurity is decreased and the content of a foreign material is decreased. However, in these, energy saving and high productivity are not considered in drying the polymer solution.

  In the one described in Patent Document 3, a new dope film is made by making a reference dope and adding an additive solution according to the kind to the dope. However, depending on the type, there are cases where it is desired to change the polymer itself. In this case, a new reference dope corresponding to a new variety is manufactured as in the conventional case. Then, it is necessary to perform replacement so that a new reference dope flows after the old reference dope so that the entire dope channel is filled with the new reference dope.

  In the above replacement, the reference dope manufacturing process stores a mixing unit having a dissolution tank and a storage tank, a dissolution unit that cools and then filters the dope, a concentration unit that has a heater and a flash tank, and stores the concentrated dope. Since it passes through various devices such as a reservoir, the dope channel capacity is, for example, 100,000 L (liter). Therefore, when changing the reference dope itself, it is necessary to flow a new dope of about 300,000 L, which is about three times the dope channel capacity. The dope being replaced is a mixture of old and new dopes and cannot be used as a product and is discarded.

  The present invention solves such problems, and an object of the present invention is to provide a polymer purification method, equipment, and precipitated polymer that have a small amount of foreign matter and can achieve both energy saving and high productivity.

  Another object of the present invention is to provide a solution film-forming method and equipment that can be adapted to small-quantity, multi-product manufacturing, and that can reduce raw material loss and production equipment operation loss.

  According to the present invention, in the development process of small-quantity multi-product manufacturing, the precipitated cellulose acylate produced by drying the filtered dope is very soluble in the solvent, and since it has been filtered once, there is no foreign matter It was made based on.

  The polymer purification method of the present invention includes a dissolution step for dissolving a polymer in a solvent to obtain a polymer solution, a filtration step for filtering the polymer solution, an incompatibility with the polymer and the solvent, and heating to a temperature higher than the boiling point of the solvent. A polymer precipitation step of spraying a polymer solution that has undergone the filtration step onto the liquid and evaporating the solvent to precipitate the polymer.

  In addition, it is preferable that the polymer solution density | concentration of a melt | dissolution process is 2 mass% or more and 19 mass% or less. The absolute filtration accuracy of the filtration step is preferably 2 μm or more and 30 μm or less. The solvent is preferably a single solvent. Further, it is preferable that the polymer is cellulose acylate, the solvent is methylene claloid, and the liquid is water. The temperature of the cellulose acylate solution in the polymer precipitation step is preferably 20 ° C. or higher and 120 ° C. or lower, and the water is preferably 40 ° C. or higher and 100 ° C. or lower.

  The polymer purification method preferably includes a coarse drying step, a wet granulation step, and a final drying step. The coarse drying step is performed subsequent to the polymer precipitation step, and the precipitated polymer is coarsely dried. In the wet granulation step, the precipitated polymer that has undergone the coarse drying step is granulated by a wet method. In the final drying step, the precipitated polymer that has undergone the wet granulation step is finally dried. In the coarse drying step, the water content of the precipitated polymer is preferably 20% to 150%, and in the final drying step, the water content of the precipitated polymer is preferably 0.1% to 3%. The precipitated polymer of the present invention is produced by the above polymer purification method. And it is preferable to be provided as cotton-like or granular form.

  Further, the solution casting method of the present invention includes a first step for producing a polymer solution for the first type, a second step for producing a polymer solution for the second type, an adding step, a casting step, and a drying step. The polymer solution from either one of the first step and the second step is switched to the other polymer solution of the first step and the second step, and the product type is continuously switched. In the first step, the first polymer solution production apparatus having a dissolution tank, a pump, and a filter is used to dissolve the precipitated polymer obtained by the above polymer purification method in a solvent to produce a polymer solution for the first type. . In the second step, the second polymer solution production apparatus having a dissolution tank, a pump, and a filter is used to dissolve the precipitated polymer obtained by the polymer purification method in a solvent to produce a polymer solution for the second type. . In the addition step, an additive solution obtained by mixing an additive is added in-line to the polymer solution obtained from one of the first step and the second step. In the casting step, the polymer solution to which the additive liquid is added is cast as a casting dope from the casting die to the casting support to form a casting film. In the drying step, the casting membrane is peeled off from the casting support and dried. In addition, the addition process can be performed by using a plurality of additive liquid storage tanks to produce an additive liquid for the first type and an additive liquid for the second type, and switching and feeding them to add in-line. preferable.

  The polymer purification equipment of the present invention comprises a dissolution tank for dissolving a polymer in a solvent to obtain a polymer solution, a filter for filtering the polymer solution dissolved in the dissolution tank, a polymer solution incompatible with the boiling point of the solvent The liquid heated as described above is stored, and has a polymer precipitator for spraying the polymer solution from the dissolution tank toward the liquid, and a recovery device for recovering the polymer precipitated by the polymer precipitator from the liquid. It is characterized by.

  The solution tank preferably has a polymer solution concentration of 2% by mass to 19% by mass. Moreover, it is preferable that the absolute filtration precision of a filter is 2 micrometers or more and 30 micrometers or less. The solvent is preferably a single solvent. Preferably, the polymer is cellulose acylate, the solvent is methylene claloid, and the liquid is water. The temperature of the cellulose acylate solution in the polymer precipitator is preferably 20 ° C. or higher and 120 ° C. or lower, and the water is preferably 40 ° C. or higher and 100 ° C. or lower.

  The polymer purification equipment preferably has a coarse dryer, a wet granulator, and a final dryer. The coarse dryer coarsely drys the precipitated polymer. The wet granulator granulates the coarsely dried precipitated polymer by a wet method. The final dryer finally drys the granulated precipitated polymer. In the coarse dryer, the water content of the precipitated polymer is preferably 20% to 150%, and in the final dryer, the water content of the precipitated polymer is preferably 0.1% to 3%.

  The solution casting apparatus of the present invention includes a polymer purification facility, a plurality of dissolution apparatuses, an addition apparatus, a casting apparatus, and a film drying section. The dissolution apparatus has a dissolution tank for dissolving the precipitated polymer in a solvent, a pump for feeding the polymer solution from the dissolution tank, and a filter for filtering the polymer solution from the pump. The additive device includes a plurality of additive liquid storage tanks that store the additive liquid, a liquid feeding part that selectively sends the additive liquid from these additive liquid storage tanks, and an additive from the liquid feeding part from the dissolving device. It has an in-line addition part that mixes with the polymer solution. The casting apparatus casts a polymer solution to which an additive solution has been added as a casting dope onto a traveling support, and forms a casting film on the support. The film drying unit dries the cast film peeled off from the casting apparatus. In addition, the additive device may use a plurality of additive liquid storage tanks to create an additive liquid for the first product type and an additive solution for the second product type, switch them, and send them for in-line addition. preferable.

  According to the present invention, heat energy is efficiently used, the solvent can be evaporated quickly, and continuous purification is possible. Further, the obtained polymer has less impurities. Thereby, solution film formation with few foreign matter failures becomes possible.

  From the polymer solution obtained by dissolving the raw material polymer in the solvent and filtering, using the precipitated polymer obtained by evaporating the solvent, dissolving it in the solvent to create a casting dope, the conventional heating / cooling filtration process and flash concentration It is possible to dissolve only in a dissolution tank without passing through a process, and for example, a dope having a polymer concentration of about 20% by mass can be obtained. For this reason, the casting dope channel capacity required for each of these steps can be reduced to about 1/30 of the conventional one. Therefore, in the case of product change requiring the change of the raw material polymer, the amount of the new kind of dope required for replacement with the old dope is reduced to about 1/30 of the conventional amount. In addition, the old and new dope replacement times can be shortened by the reduction of the casting dope channel capacity, the equipment operation rate for obtaining the product can be increased, and a new type of film can be produced efficiently. .

It is a side view which shows the outline of a polymer refinement | purification equipment. It is a side view which shows the outline of a precipitator and a vibration dryer. It is a side view which shows the outline of solution casting apparatus. It is a side view which shows the outline of a mixing apparatus. It is a perspective view which shows a static mixer. It is sectional drawing which shows a dynamic mixer. It is a side view which shows the outline of the precipitation machine of another embodiment, a vibration sieve, and a hot air dryer. It is a block diagram which shows the outline of a granulation equipment.

(Polymer purification equipment)
As shown in FIG. 1, the polymer purification equipment 5 includes a dissolution tank 6, a dope supply pipe line 7, a precipitator 8, a discharge unit 9, and a vibration dryer 10. The dope supply pipe line 7 includes a switching valve 7a, a pump 11, a filter 12, and a pressure control valve 7b.

  A raw material cellulose acylate (hereinafter referred to as a raw material CA) 17 as a raw material polymer is charged into the dissolution tank 6. A solvent storage tank 14 is connected to the dissolution tank 6 via a solvent supply pipe 13. The solvent storage tank 14 stores methylene claloid 18 as a solvent. Then, the methylene claloid 18 is introduced into the dissolution tank 6 from the solvent storage tank 14 through the solvent supply pipe 13. The dissolution tank 6 has a stirrer 6a. By this stirrer 6a, dissolution of the raw material CA17 into the methylene claloid 18 is promoted, and a dilute polymer solution (dilute dope) 21 in which the raw material CA17 is dissolved in the methylene claloid 18 is obtained. The concentration of the raw material CA17 in the diluted dope 21 (polymer solution concentration) is, for example, 7% by mass. The polymer concentration is 2% by mass or more and 19% by mass or less, and preferably 5% by mass or more and 14% by mass or less. If the polymer concentration is less than 2% by mass, the solvent removal cost increases, which is not preferable. Moreover, when it exceeds 19 mass%, a viscosity will be high and the pressure loss by filtration will become high, and is unpreferable.

  In the dissolution tank 6, the temperature of the diluted dope 21 is maintained at 120 ° C., for example, due to the heating and heat retaining effect by the jacket 6 b. In addition to heating the diluted dope 21 in the dissolution tank 6, a separate heating device may be provided on the downstream side of the dissolution tank 6 to heat the diluted dope 21 to a predetermined temperature. The temperature of the diluted dope 21 is preferably 20 ° C. or higher and 120 ° C. or lower. If the temperature of the diluted dope 21 is less than 20 ° C., cooling is necessary, and energy required for evaporation increases, which is not preferable. Moreover, when it exceeds 120 degreeC, it will become easy to generate | occur | produce corrosion of a piping raw material generally, and is not preferable. The set temperature of the diluted dope 21, for example, 120 ° C. is maintained up to the pressure control valve 7 b, and is about 40 ° C. when ejected from the first nozzle 25 as will be described later. The obtained diluted dope 21 is sent to the filter 12 of the dope supply line 7.

  In the filter 12, for example, foreign matters of about 5 μm are removed from the sent thin dope 21. The type of the filter 12 is not particularly limited, but an auxiliary filtration method, a metal filtration method, a filter paper filtration method, or the like is preferably used. The absolute filtration accuracy in each filtration method is preferably in the range of 2 μm to 30 μm, and the absolute filtration accuracy is preferably determined according to the purpose of use. For example, the absolute filtration accuracy of 5 μm or less means that the size that can be removed by 99.9% or more is 5 μm.

  The diluted dope 21 that has passed through the filter 12 is kept at a constant pressure by the pressure control valve 7 b and is sent to the precipitator 8.

  As shown in FIG. 2, the precipitator 8 is a hermetically sealed type in which internal gas and liquid do not leak to the outside. For example, a horizontal cylindrical tank is used. In order to evaporate the methylene claloid 18 in the dilute dope 21, warm water 22 maintained at a temperature equal to or higher than the boiling point of the methylene claloid 18 is stored inside the precipitator 8.

  A discharge nozzle 24 for an inert gas (such as air or nitrogen) is disposed at the bottom of the precipitator 8. The temperature of the inert gas sent to the discharge nozzle 24 is maintained at 20 ° C. or higher and 100 ° C. or lower. In the inert gas discharged from the discharge nozzle 24, the methylene claloid 18, which is a hardly soluble component in water, is diffused. When the initial concentration of the methychrome in the inert gas bubbles is 0, and when the concentration of the methychrome in water is high, the methylene claloid 18 is removed from the water through the boundary film of water and bubbles using this concentration difference as a driving force. Move to the bubble. And the higher the bubble temperature, the higher the saturated vapor pressure in the bubble, so the amount of methylene claloid that can move increases. As a result, evaporation of the methylene claloid 18 in the diluted dope 21 is promoted, and the efficiency is improved. If the temperature of the inert gas exceeds 100 ° C., there is a concern that water will boil, and as a result, the proportion of water in the steam increases.

  The temperature of the hot water 22 supplied to the precipitator 8 is preferably 40 ° C. or higher and 100 ° C. or lower. Below 40 ° C., the methylene claloid 18 does not evaporate and cannot be deposited. In addition, when the temperature exceeds 100 ° C., a pressurized operation is required to keep water in a liquid state, which is not preferable.

  A first nozzle 25 and a second nozzle 26 are disposed on the inner surface of the precipitator 8. In addition, a stirring blade 27 is disposed inside the precipitator 8. The stirring blade 27 is configured by fixing a plurality of blade bodies 27b to a rotating shaft 27a. The stirring blade 27 is attached in the precipitator 8 so that the rotating shaft 27a is horizontal. One end of the rotating shaft 27a protrudes from the precipitator 8 to which a motor 29 is connected. Then, by rotating the motor 29, the stirring blade 27 is rotated, the hot water 22 in the precipitator 8 is stirred, and the water surface temperature is kept constant.

  The rotating shaft 27a of the stirring blade 27 may be one or plural. In the case of a plurality, the rotation direction may be changed between adjacent ones, or the same direction may be used. And it is preferable to make it the warm water 22 flow toward the discharge port 8a near the water surface. The arrangement direction of the stirring blades 27 and the type of the stirring blades 27 are not limited to those shown in the drawings, and the hot water 22 in the precipitator 8 is only required to be stirred.

  As shown in FIG. 1, the dope supply line 7 is connected to the first nozzle 25. Thereby, the diluted dope 21 (refer FIG. 2) is injected from the 1st nozzle 25, and is spread | dispersed toward the water surface. The pipe line 7 from the pressure control valve 7b to the first nozzle 25 of the precipitator 8 is formed short, and the diluted dope 21 is stably flash-evaporated in the precipitator 8. Although only one first nozzle 25 is arranged, the number of arrangement is not limited to one and may be increased as appropriate.

  A hot water supply conduit 28 is connected to the second nozzle 26. As shown in FIG. 2, the 2nd nozzle 26 is comprised from the nozzle head 26a distribute | arranged to the longitudinal direction of the precipitator 8, and the several nozzle main body 26b distribute | arranged to this nozzle head 26a with a predetermined pitch. . The hot water supply pipe 28 sends the hot water 22 from the hot water storage tank 39 to the second nozzle 26. Thereby, the warm water 22 is jetted from the second nozzle 26 and sprayed toward the water surface.

  It is preferable to spray the diluted dope 21 by the first nozzle 25 and the hot water 22 by the second nozzle 26 uniformly in the width direction of the cylindrical tank. Thereby, precipitation of a cellulose acylate can be performed efficiently.

  As shown in FIG. 1, the hot water supply line 28 includes a pump 28 b, a filter 28 c, a check valve 28 d, and a temperature controller 28 e in addition to a switching valve 28 a that is appropriately provided as necessary. The pump 28b adjusts the flow rate of the hot water 22 by adjusting the rotation speed. The filter 28 c filters foreign matter from the hot water 22. The temperature controller 28e performs final temperature adjustment of the hot water 22 whose temperature is adjusted in the hot water storage tank 39. Thereby, the warm water 22 (see FIG. 2) heated to an appropriate temperature is jetted from the second nozzle 26 toward the water surface at a predetermined flow rate.

  As shown in FIG. 2, the diluted dope 21 sprayed from the first nozzle 25 contacts the warm water 22 in the depositor 8. The hot water 22 is heated and held above the boiling point of the methylene claloid 18. For this reason, the methylene claloid 18 in the diluted dope 21 in contact with the warm water 22 is instantly evaporated by heating with the warm water 22, and the raw material CA17 is precipitated, for example, in the form of a thread, and precipitated cellulose acylate (hereinafter simply referred to as precipitated CA). 30. In the present embodiment, warm water 22 heated to a boiling point or higher of the methylene claloid 18 (for example, 80 ° C.) is sprayed from the second nozzle 26 from above the water surface, and the methylene claroid 18 in the diluted dope 21 is evaporated. Is promoting.

  At one end of the precipitator 8, a discharge port 8a for the precipitation CA30 is opened. The warm water 22 near the water surface flows toward the discharge port 8a by the rotation of the stirring blade 27 so that the precipitation CA30 advances toward the discharge port 8a. Further, the plurality of nozzle bodies 26b of the second nozzle 26 are disposed so as to be inclined such that the ejection direction is directed toward the discharge direction of the deposition CA30. Therefore, the precipitation CA 30 is also sent out toward the discharge port 8a by the extrusion by the hot water 22 injected from the second nozzle 26. Further, instead of or in addition to sending out the precipitated CA30 due to the momentum of injection by the first nozzle 25 and the second nozzle 26, the precipitated CA30 may be sent out to the discharge port 8a by overflowing the hot water 22. A method for causing the hot water 22 to overflow and discharging the precipitated CA 30 will be described in detail in the second embodiment shown in FIG.

The discharge part 9 of precipitation CA30 is connected to the discharge port 8a. Further, a first squeeze roller 33 is disposed on the precipitator 8 side, and a second squeeze roller 34 is disposed on the discharge unit 9 so as to sandwich the discharge port 8a.

    The first squeeze roller 33 and the second squeeze roller 34 are composed of a pair of nip rollers. These squeeze rollers 33 and 34 are individually rotatable, and both rotate at the same speed during normal discharge. Further, when the precipitation CA30 is cut out, the second squeeze roller 34 is rotated while the first squeeze roller 33 is stopped and the precipitation CA30 is sandwiched. Thereby, precipitation CA30 which continues between these squeeze rollers 33 and 34 is divided. In addition, instead of the division by the individual rotation of the squeeze rollers 33 and 34, the continuous deposition CA30 may be separated by a cutting means such as a cutter.

  Before and after the nip position of the squeeze rollers 33, 34, guide plates 35a to 35c curved in an arc shape are arranged. These guide plates 35a to 35c guide the deposition CA30. The first guide plate 35 a is fixed, and guides the precipitated CA 30 from the water surface to the nip position of the first squeeze roller 33. The second guide plate 35b and the third guide plate 35c are movable. The second guide plate 35 b guides the deposition CA 30 from the nip position of the first squeeze roller 33 to the nip position of the second squeeze roller 34. The third guide plate 35 c guides the deposition CA 30 into the discharge unit 9 from the nip position of the second squeeze roller 34. The second and third guide plates 35b and 35c move in conjunction with the opening and closing operations of the first door 40 and the second door 41, and when the doors 40 and 41 are closed, the doors 40 and 41 interfere from the guide position. Displacement to a retracted position where there is nothing.

  The hot water 22 that has overflowed in the precipitator 8 due to the injection of the hot water 22 from the second nozzle 26 is returned from the overflow recovery part 37 to the hot water storage tank 39 (see FIG. 1) through the water recovery conduit 38. As shown in FIG. 1, the water recovery line 38 includes a switching valve 38a, a pump 38b, a filter 38c, and a check valve 38d. When the foreign matter contained in the warm water 22 is filtered by the filter 38c, the warm water 22 is returned to the warm water storage tank 39.

  As shown in FIG. 2, a first door 40 is arranged at the discharge port 8 a of the precipitator 8, a second door 41 is arranged at the discharge port 8 a of the overflow recovery unit 37, and a third door 42 is arranged at the outlet of the discharge unit 9. Has been. When the first door 40 is closed, the inside of the precipitator 8 is sealed. When the second door 41 is closed, the overflow recovery part 37 is sealed. When the third door 42 is closed, the inside of the discharge unit 9 is sealed. These doors 40-42 operate individually. The first door 40 and the second door 41 are normally open. And when a fixed amount of precipitation CA30 accumulates in the discharge part 9, the 1st-3rd doors 40-42 interlock | cooperate according to the division | segmentation operation | movement of precipitation CA30. Thereby, precipitation CA30 can be sent out to the following vibration dryer 10 with the airtight state in the precipitator 8 maintained.

  First, when a certain amount of deposition CA30 is accumulated in the discharge unit 9, the deposition CA30 is divided by the individual rotation control of the squeeze rollers 33 and 34. Thereafter, the first door 40 is closed. Further, after the separation of the precipitation CA30, the second door 41 is closed at a timing when the rear end of the separated precipitation CA30 exits the overflow recovery part 37. The first door 40 is opened after the second door 41 is closed. Moreover, after the 2nd door 41 is closed, the 3rd door 42 opens. Thereby, the accumulated precipitation CA30 slides down to the vibration dryer 10 in the next step. When precipitation CA30 is discharged | emitted from the discharge part 9, the 3rd door 42 will be closed. Thereafter, the second door 41 is opened, and the precipitated CA30 is discharged by the same processing procedure.

  In the vibration dryer 10, moisture is dried from the precipitation CA 30 by blowing dry air from the duct 45 while applying vibration from the vibration mechanism 44 to the precipitation CA 30 delivered from the discharge unit 9. Note that moisture may be separated from the precipitated CA30 by simply applying vibration without blowing dry air. In this case, a drying device is separately provided on the downstream side, and moisture is removed from the precipitated CA 30 by, for example, hot air drying or storage for a certain period of time in a drying cabinet, and drying is performed.

  The vibration dryer 10 has a discharge part 46 at the outlet of the precipitation CA30. The discharge unit 46 includes a first door 47 and a second door 48, and discharges the precipitated CA 30 from the vibration dryer 10 while holding the vibration dryer 10 in a sealed state. Normally, the second door 48 is closed, and when the discharge amount is reached, the second door 48 is opened after the first door 47 is closed. Thereby, the accumulated precipitation CA30 is dropped, for example, into the flexible container bag 49 set downward. After the deposition CA 30 is dropped, the first door 47 is opened after the second door 48 is closed, and the deposition CA 30 is accumulated in the discharge portion 46. The dropping into the flexible container bag 49 is performed in units of the separated precipitation CA30. However, the separation CA30 may be divided and dropped at an arbitrary position by providing a separate cutting device.

  Precipitation CA30 obtained in this way is classified for each type of raw material CA17, production area, etc., and stored as precipitation CA30. This deposited CA30 is used by appropriately selecting the type when producing a new film having different optical characteristics.

  Note that squeeze rollers 33 and 34 may be provided on the outlet side of the vibration dryer 10 in the same manner as the precipitator 8, and the squeeze rollers 33 and 34 may squeeze moisture from the precipitation CA.

  As shown in FIG. 1, the hot water storage tank 39 has a heater 39a, a jacket 39b, and a stirrer 39c. The heater 39a heats the hot water 22 in the hot water storage tank 39 to a constant temperature. A heat medium is circulated in the jacket 39b, and the water in the hot water storage tank 39 is held at a constant temperature. In addition, when the hot water 22 in the hot water storage tank 39 becomes equal to or less than a certain amount, a certain amount of hot water 22 is replenished from the pure water storage tank 60 to the hot water storage tank 39 through the water supply pipe 51. The water supply pipe 51 includes a switching valve 51a, a pump 51b, and a pure water filter 51c. The pure water filtration device 51 c filters impurities in the hot water 22.

  The methylene claloid 18 used in the present embodiment is a substance whose use and disposal are monitored by the PRTP (Pollutant Release and Transfer Register) method because of concern about environmental burden and human toxicity. For this reason, discharge from the factory building to the outside must be avoided. Therefore, in addition to making the building a double structure, for example, to improve hermeticity, it is necessary to reduce methylene claroid gas leaking from each device as much as possible. For this reason, in this embodiment, the methylene claroid 18 is circulated only in the closed circulation system. The precipitator 8, the discharge unit 9, the vibration dryer 10, and the hot water storage tank 39 are individually sealed. Then, a solvent recovery line 55 is connected to each of the sealed devices 8 to 10 and 39 so as to be reused in the circulation system to prevent the methylene claroid gas from leaking to the outside.

  The methylene claloid 18 evaporated inside the precipitator 8, the discharge unit 9, the vibration dryer 10, and the hot water storage tank 39 is sent to the condenser 56 through the solvent recovery line 55. The solvent recovery line 55 has a switching valve 55a and a pump 55b. As will be described later, the methylene claloid 18 sent from the solvent recovery line 55 is separated from water and used again after being circulated.

  In addition, although illustration was abbreviate | omitted, the building and the arrangement space of each apparatus are partitioned off as a sealed space. And methylene claroid gas is collect | recovered for every partition unit, and it is adsorption-recovered with an adsorption tower etc. FIG. For this reason, even if methylene claroid gas leaks from each of the devices 8 to 10 and 39, it is finally captured and is not released to the outside of the building.

  In the condenser 56, the gas mixed from the steam and the methylene claloid 18 sent from the devices 8 to 10 and 39 is heat-exchanged with cold water, for example, and aggregates and liquefies. The agglomerated liquid is sent to the separation tank 57. The separation tank 57 separates the liquid into methylene claloid 18 and hot water 22 by specific gravity. The methylene claloid 18 is located in the lower layer, and the hot water 22 is located in the upper layer. For this reason, the separation tank 57 has a jacket 57a and a switching valve 57b. In the jacket 57a, for example, water is circulated as a temperature control medium, and the methylene claloid 18 and the hot water 22 are held at appropriate temperatures.

  The hot water 22 separated in the separation tank 57 is sent to the pure water storage tank 60 and the methylene claloid 18 is sent to the solvent storage tank 14 for storage.

  Hot water 22 supplied to the precipitator 8 is stored in a hot water storage tank 39. The hot water storage tank 39 has a jacket 39b and is maintained at a constant temperature by the circulation of the temperature control medium. Water from the hot water storage tank 39 is sent to the second nozzle 26 in the precipitator 8 through the hot water supply pipe 28 and is sprayed toward the water surface by the second nozzle 26. And the temperature of the warm water 22 is adjusted by the temperature controller 28e. Further, the flow rate of the hot water 22 is adjusted by controlling the rotation speed of the pump 28b, and the water surface in the precipitator 8 is held at a fixed position.

  The hot water 22 separated from the precipitation CA 30 by the squeeze roller 34 is returned to the hot water storage tank 39 by the overflow recovery part 37 and the water recovery pipeline 38. Further, in order to replenish the hot water 22 that has decreased due to evaporation, a certain amount of water is replenished from the pure water storage tank 60 via the water supply pipe 51.

  Next, the solution film-forming facility 68 and method using the precipitated CA30 obtained by the polymer purification facility 5 will be described. When manufacturing a small amount of various types of films, a mixing facility having a large-scale melting process as in the past, when switching to a new variety, the flow path capacity from the melting tank to the casting die is three times as large. It is necessary to replace the old dope with the new dope by flowing a new variety of cast dope. In addition, the dope being replaced is a mixture of old and new dopes and cannot be used as a product. In the present invention, in order to shorten the time required to replace the old dope with the new dope, the dope channel capacity of the mixing device 69 is set to 1/30 of the dope channel capacity of the conventional mixing device.

  The reason why the dope channel capacity of the mixing device 69 can be reduced is as follows. The precipitated CA30 is obtained by drying the diluted dope 21 in which the raw material CA17 is dissolved in the solvent of the methylene claloid 18, and is easily dissolved in the solvent. Further, in purifying the precipitated CA30, since the precipitated CA30 is precipitated from the state in which the foreign matters are removed by filtration at a dilute concentration, the precipitate CA30 is dissolved so that the foreign matters are very few. It has become. For these reasons, various devices such as a mixing section, a dissolving section, a concentrating section, and a storing section, which have been necessary in the past, have become unnecessary. Therefore, the loss of the casting dope 85 and the time loss required for replacement are reduced by the amount of the reduced flow path capacity, and efficient production switching of new varieties can be performed. Hereinafter, the solution casting apparatus 68 will be described with reference to FIG.

[Solution casting equipment]
As illustrated in FIG. 3, the solution casting apparatus 68 includes a mixing device 69, a casting device 73, a pin tenter 74, a drying chamber 75, and a winding device 76.

  As shown in FIG. 4, the mixing device 69 includes at least two systems of a first dissolution unit 70 </ b> A and a second dissolution unit 70 </ b> B, and an inline addition unit (addition device) 71.

  The first dissolution unit 70A includes a dissolution tank 80, a pump 81, and switching valves 87a and 87b. The dissolution tank 80 has the same configuration as the dissolution tank 6. The dissolution tank 80 is charged with a first precipitation CA 30a obtained from the first raw material CA 17a and a solvent 79 for dissolving the first precipitation CA 30a. The first precipitated CA 30 a is dissolved in the solvent 79 by stirring with the stirrer 80 a after the charging. The second melting unit 70B is configured in the same manner as the first melting unit 70A, and the same members are denoted by the same reference numerals. A second precipitation CA30b obtained from a second raw material CA17b different from the first raw material CA17a is charged into the second dissolution unit 70B together with the solvent 79. By alternately using the first and second melting units 70A and 70B, the current type casting dope 85 using the first precipitation CA 30a and the next type casting dope 85 using the second precipitation CA 30b are used. Can be made separately.

  The first switching valve 87a is opened when the dope liquid is fed, and the second switching valve 87b is closed. Further, when the other melting unit 70B is used, the switching valves 87a and 87b are opened and closed opposite to the dope feeding liquid, the first switching valve 87a is closed and the second switching valve 87b is opened. The dope 85 circulates without being fed. After the circulation, the casting dope 85 of the dissolution tank 80 is sent to a storage tank (not shown) for reuse. Further, when the original casting dope 85 is used after manufacturing a new type of film, it is circulated as it is.

  Although not shown in the figure, a cleaning line and a dope recovery line are connected to each dissolution unit 70A and 70B. The dope recovery line recovers the surplus casting dope 85 by sending it to another storage tank or the like. In the cleaning line, the surplus casting dope 85 is fed and emptied, for example, a solvent is introduced, and the inside of the dissolution tank 80 is cleaned for the next new dope.

  By using the precipitated CA30 that does not have foreign matters and is easily dissolved in the solvent, the casting dope 85 having a concentration of, for example, about 20% by mass in the dissolution tank 80 can be produced by the dissolution operation in the dissolution tank 80. Therefore, it does not go through various processes with a high running cost using a complicated apparatus such as heating, pressurization, and concentration necessary for conventional dope preparation. Moreover, it is only necessary to remove foreign matters mixed during the handling of the precipitated CA 30a, etc., and high-precision filtration in a high concentration dope state becomes unnecessary, and a filter described later can be small and compact.

  Further, since the mixing device 69 is configured only from the dissolution tank 80 without adopting a complicated device configuration, the flow channel capacity of the casting dope 85 to the casting die 78 is 1/30 compared to the conventional one. It can be made as small as possible. For this reason, when switching the kind, when the new kind of casting dope 85 is flowed in an amount about three times the channel capacity and replaced with the new kind of dope, the flow rate for replacement is changed. It can be reduced to about 1/30 compared with the conventional one. Moreover, since the dope flow rate to be replaced is reduced, the time required for switching the new type can be shortened, and the new type dope can be efficiently switched.

  The casting dope 85 dissolved in the dissolution tank 80 is sent to the addition unit 71 by the pump 81. The addition unit 71 includes an addition nozzle 86, a static mixer 82, a dynamic mixer 83, and a filter 84.

  An additive liquid feeding section 88 is connected to the addition nozzle 86. The additive liquid feeding section 88 includes two systems of additive liquid storage tanks 89a and 89b, a three-way valve 90, a pump 91, and switching valves 92a to 92c. The three-way valve 90 selects one of the additive liquid storage tanks 89a and 89b, for example, 93a. The pump 91 sends the selected additive liquid 93a to the addition nozzle 86. The switching valves 92 a to 92 c are opened and closed when the additive liquids 93 a and 93 b are switched, and any one of the additive liquids 93 a and 93 b is selectively sent to the addition nozzle 86. Each additive liquid storage tank 89a, 89b has a dissolving function in addition to storage. Then, in the additive liquid storage tanks 89a and 89b, when various additives and solvents necessary for the casting dope 85 are charged, the stirring blades 89c are rotated so that necessary components are blended in an appropriate ratio. Additive liquids 93a and 93b are made. The various additives for the additive liquid and the amount of the additive are determined in advance for each type of film to be manufactured, and the necessary additive and the amount thereof are charged into the additive liquid storage tank 89a.

  As shown in FIG. 5, the static mixer 82 includes a plurality of first elements 82b and a plurality of second elements 82c arranged in series in the flow channel 82a of the casting dope 85. The first element 82b and the second element 82c have different elements with different mixing angles and directions. In addition, you may change suitably the kind of dissimilar element, and the number of serial arrangement | positioning. The additive liquid 93a is mixed with the casting dope 85 by passing through these elements 82b and 82c.

  As shown in FIG. 6, the dynamic mixer 83 mixes the casting dope 85 mixed with the additive liquid 93a by the stator 83b and the rotator 83c in the pipe 83a. The rotator 83c is fixed to the drive shaft 83d. The rotator 83c rotates relative to the stator 83b by the rotation of the drive shaft 83d. The drive shaft 83d is connected to a motor (not shown). Thereby, the additive liquid 93a is further uniformly mixed in the casting dope 85.

  A seal member 83e and a labyrinth member 83f are disposed at both ends of the pipe 83a. A spiral protrusion 83g protrudes from the peripheral surface of the labyrinth member 83f. The labyrinth member 83f is fixed to the drive shaft 83d and rotates integrally with the drive shaft 83d. The spiral ridges 83g of the left and right labyrinth members 83f have opposite spiral directions on the left and right. When the drive shaft 83d rotates, the casting dope 85 that enters from the seal member 83e is returned into the pipe 83a by each spiral protrusion 83g. Thereby, the casting dope 85 is prevented from leaking from the gap between the drive shaft 83d and the seal member 83e.

  As shown in FIG. 4, the casting dope 85 that has passed through the dynamic mixer 83 is filtered by a filter 84. Since the foreign matter is removed during the precipitation CA30, the filtration load of the filter 84 is small and the filtration life is extended. Thereafter, the casting dope 85 is sent to a casting die 78 and cast on a rotating casting drum 95 as shown in FIG.

  The casting apparatus 73 includes a casting die 78, a casting drum 95, and a peeling roller 96, which are disposed in the casting chamber 73a. The casting drum 95 is rotated around an axis by a driving device (not shown). The casting drum 95 is set to a temperature at which the casting film 97 is cooled by a temperature control device (not shown).

  The casting die 78 continuously flows the casting dope 85 toward the peripheral surface of the rotating casting drum 95. A belt-shaped casting film 97 is formed on the casting drum 95 by the casting dope 85. By cooling, the casting film 97 on the casting drum 95 is in a state where it can be conveyed independently. Thereafter, the casting film 97 is peeled off from the casting drum 95 by the peeling roller 96 to form a belt-like wet film 98.

  A crossover 99 is arranged between the casting chamber 73 a and the pin tenter 74. The crossover 99 has a conveyance roller 99 a and sends the wet film 98 to the pin tenter 74. The pin tenter 74 has a number of pin plates. The pin plate is held through both side edges of the wet film 98. The pin plate is circulated by the chain and conveys the wet film 98. During this conveyance, dry air is sent to the wet film 98. As a result, the wet film 98 is dried and becomes a belt-like film 100.

  A side slitter 101 is provided downstream of the pin tenter 74. The side slitter 101 cuts both side edges of the film 100. The cut side edges are sent to the crusher by air blowing and crushed. What grind | pulverized both sides edge part melt | dissolved in the solvent is used instead of raw material CA17 and precipitation CA30, and reuse is aimed at.

  A large number of rollers 75a are arranged in the drying chamber 75, and the film 100 is wound around and conveyed. The temperature, humidity, and the like of the atmosphere in the drying chamber 75 are adjusted by an air conditioner (not shown), and the drying of the film 100 is promoted when the film 100 passes through the drying chamber 75.

  Between the drying chamber 75 and the winding device 76, a cooling chamber 102 that cools the film 100, a forced static elimination device (static elimination bar) that neutralizes the film 100, and knurling that imparts knurling to both side edges of the film 100. A roller or the like is provided. The winding device 76 has a press roller and winds the film 100 around a winding core.

  Next, the operation of this embodiment will be described. As shown in FIG. 1, when manufacturing the precipitation CA30, the raw material CA17 and the methylene claroid 18 are put in the dissolution tank 6 and stirred by the stirrer 6a, for example, a dilute dope 21 having a polymer solution concentration of 7% by mass is produced. It is done. The diluted dope 21 passes through the filter 12, the pressure is adjusted to be constant by the pressure control valve 7 b, and sent to the first nozzle 25 of the depositor 8. In this embodiment, since the concentration of the diluted dope 21 is 7% by mass, the filtration load is small and high-performance filtration is possible.

  As shown in FIG. 2, the diluted dope 21 is jetted from the first nozzle 25 toward the water surface in the precipitator 8 and diffused to the water surface. The temperature of the hot water 22 is set to a temperature higher than the boiling point of the methylene claloid 18. Accordingly, the methylene claloid 18 in the diluted dope 21 in contact with the water surface is instantly evaporated by the heat from the hot water 22, and a thread-like precipitate CA30 is obtained. The deposited CA30 can also efficiently evaporate the methylene claloid 18 by a hot water shower from the second nozzle 26. Moreover, the precipitation CA30 is sent to the discharge port 8a by the injection of the hot water 22 from the stirring blade 27 and the second nozzle 26.

  The first and second squeeze rollers 33 and 34 sandwich the sent precipitation CA 30 and send it to the discharge unit 9. At this time, the precipitation CA30 is sandwiched by the squeeze rollers 33 and 34, and the hot water 22 contained in the precipitation CA30 is squeezed out. The hot water 22 squeezed by the first squeeze roller 33 is returned to the precipitator 8. The hot water 22 squeezed by the second squeeze roller 34 is returned to the hot water storage tank 39 via an overflow recovery part 37 and a water recovery pipe line 38 formed near the discharge port 8a.

  The first squeeze roller 33 and the second squeeze roller 34 are individually controlled for rotation. Then, for example, by rotating the second squeeze roller 34 in a state where the rotation of the first squeeze roller 33 is stopped, the precipitation CA 30 is pulled by the nip conveyance of the second squeeze roller 34, and the first squeeze roller 33 Divided at the nip position. The rear end of the separated deposition CA 30 falls into the discharge unit 9 by the rotation of the second squeeze roller 34. By separating the precipitation CA30 that is continuously sent in this manner, the precipitation CA30 is discharged from the precipitation device 8 while keeping the precipitation device 8 in a sealed state and suppressing leakage to the outside of the methylene claloid 18. Can be sent to part 9.

  The separated CA30 is dropped into the vibration dryer 10 when the third door 42 of the discharge unit 9 is opened. When precipitation CA30 is sent out from the discharge part 9, the 2nd door 41 will open after the 3rd door 42 closes. Thereafter, the first squeeze roller 33 rotates to send out the precipitated CA 30 to the discharge unit 9. Thereafter, by repeating the same process, the continuously discharged precipitation CA30 is divided into an appropriate length and sent to the vibration dryer 10 in the next step while keeping the precipitate 8 in a sealed state. Can do.

  In the vibration dryer 10, for example, vertical vibration is applied to the precipitation CA30 to promote drying of water in the precipitation CA30. Further, hot air is sent from the duct 45 to dry the precipitated CA30.

  As described above, the precipitated CA30 from which the foreign matters are removed from the raw material CA17 is obtained. This precipitated CA30 is more soluble in methylene claloid 18 and other various solvents than the raw material CA17. This is presumably because it was once dissolved at the stage of the raw material CA17 and the hardly soluble portion in the raw material CA17 disappeared. The precipitated CA30 is stored by being classified according to the type of the raw material CA17 and the production area.

  In the case of switching to a new variety, first, the precipitated CA 30 that matches the new variety is selected. Moreover, a solvent, its compounding quantity, etc. are specified based on prescription of a new kind. Next, as shown in FIG. 4, the precipitated CAs 30 a and 30 b and the solvent 79 are put into the dissolution tank 80. And these are uniformly mixed by the stirrer 80a, and the casting dope 85 for new breeds is made. Further, an additive liquid 93 a for a new variety is prepared by the storage tank 89 a of the additive liquid feeding section 88, and this additive liquid 93 a is sent to the addition nozzle 86. Then, the additive solution 93 a is added in-line into the casting dope 85 by the addition nozzle 86.

  The casting dope 85 to which the additive solution 93a has been added is mixed and uniformed by the static mixer 82 and the dynamic mixer 83 and sent to the casting die 78 (see FIG. 3). As described above, in the present embodiment, when the kind is switched, a new kind of casting dope 85 is prepared and replaced with the old casting dope 85, and the old and new dopes are replaced in the casting dope channel of the addition unit 71. Just get better. In addition, the flow path capacity required for the replacement of the casting dope 85 is compared with the case where, for example, a casting dope of 20% by mass is manufactured by dissolving, filtering, and flash-concentrating the raw material CA as shown in Patent Document 1 with a solvent. Thus, the channel capacity is about 1/30, and the replacement amount of the old and new dopes at the time of switching the type can be reduced to about 1/30 compared with the conventional one.

  Moreover, since the replacement amount of the old and new dopes is greatly reduced, the work time required for replacement of the old and new dopes can be shortened, and the operating efficiency of the equipment can be increased. As described above, when changing the type, the precipitation CA of the casting dope 85 and the switching of the additive solution can be individually performed, so that efficient type switching can be performed.

  In this embodiment, the casting drum 95 is used as the support, but the present invention is not limited to this, and a casting band may be used. In this case, the casting band is run by passing the casting band over a pair of drums whose rotation axes are horizontal and rotating the drum.

  In the present embodiment, the casting film 97 can be peeled off by a cooling gelation method for cooling the casting film 97 on the casting drum 95, but the present invention is not limited to this, and a drum, a band, or the like is not limited thereto. The casting film may be peeled off by a drying method for drying the casting film on the support.

  The film 100 obtained by the present invention can be used particularly for a retardation film or a polarizing plate protective film.

  The width of the film 100 is preferably 600 mm or more, and more preferably 1400 mm or more and 2500 mm or less. Further, the width of the film 100 may be larger than 2500 mm. The film thickness of the film 100 is preferably 15 μm or more and 120 μm or less.

(polymer)
The polymer that can be used in the present invention is not particularly limited as long as it is a thermoplastic resin, and examples thereof include cellulose acylate, a lactone ring-containing polymer, a cyclic olefin, and polycarbonate. Of these, cellulose acylate and cyclic olefin are preferable, and cellulose acylate containing an acetate group and propionate group and a cyclic olefin obtained by addition polymerization are particularly preferable.

(Cellulose acylate)
Only one type of acyl group may be used in the cellulose acylate of the present invention, or two or more types of acyl groups may be used. When two or more kinds of acyl groups are used, it is preferable that one of them is an acetyl group. The ratio in which the hydroxyl group of cellulose is esterified with carboxylic acid, that is, the substitution degree of the acyl group satisfies all of the following formulas (I) to (III) is preferable. In the following formulas (I) to (III), A and B represent the substitution degree of the acyl group, 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. It is. In addition, it is preferable that 90 mass% or more of triacetyl cellulose (TAC) is 0.1 mm or more and 4 mm or less of particles.
(I) 2.0 ≦ A + B ≦ 3.0
(II) 1.0 ≦ A ≦ 3.0
(III) 0 ≦ B ≦ 2.9

  The total substitution degree A + B of the acyl group is more preferably 2.20 or more and 2.90 or less, and particularly preferably 2.40 or more and 2.88 or less. Further, the substitution degree B of the acyl group having 3 to 22 carbon atoms is more preferably 0.30 or more, and particularly preferably 0.5 or more.

  The details of cellulose acylate are described in paragraphs [0140] to [0195] of JP-A-2005-104148. These descriptions are also applicable to the present invention. The same applies to additives such as solvents and plasticizers, deterioration inhibitors, UV absorbers (UV agents), optical anisotropy control agents, retardation control agents, dyes, matting agents, release agents, release accelerators, etc. JP-A-2005-104148 describes in detail in paragraphs [0196] to [0516]. Moreover, the cellulose which is a raw material of a cellulose acylate may be obtained from either linter or pulp.

  In the above embodiment, since the methylene claloid 18 is used as the solvent for the raw material CA17 and the methylene claroid 18 is evaporated by the hot water 22 heated to the boiling point of the methylene claloid 18 or more, the equipment configuration is simple. Precipitate CA30 having excellent solubility can be efficiently produced with reduced heat energy loss. Also, the use of a single solvent simplifies subsequent recovery and reuse of the solvent.

  By separating the precipitation CA30 at the discharge section 9 and keeping the precipitator 8 in a hermetically sealed state, a solvent such as methylene claloid 18 can be used without leaking outside the apparatus.

  In addition, in the said embodiment, it was set as the structure which divides precipitation CA30 in the discharge part 9, and the depositor 8 is hold | maintained in the sealing state, For example, the squeeze roller 33 of the depositor 8 and the tank end plate of the depositor 8 By adopting a hermetically sealed structure that keeps the space between the two, the separation by the discharge unit 9 becomes unnecessary. In this case, it is preferable that the vibration drier 10 is divided by a cutter or a pair of rollers. Furthermore, you may perform sealing of the precipitator 8 and the discharge part 9, and division | segmentation of precipitation CA30 using the rotary valve 65 (refer FIG. 7) mentioned later.

  In the above embodiment, methylene claloid 18 is used as a solvent for the raw material CA17, and the methylene claloid 18 is evaporated by the hot water 22 heated to the boiling point of the methylene claloid 18 or more. However, the present invention is limited to these substances. However, if the solvent is a good solvent, other single solvents or mixed solvents can be used. Moreover, as long as it is a liquid which can be heated more than the boiling point of a solvent, you may use another liquid, without being limited to water. In the case of using a mixed solvent, the mixed solvent recovered by the solvent recovery pipe 55 is separated and recovered as each solvent or reused as a mixed solvent.

  Moreover, in the said embodiment, although precipitation CA30 was sent to the discharge port direction with the flow of the warm water 22, instead of or in addition to this, it is made to send to the discharge port 8a with a roller or another conveyance part. Also good.

  In the said 1st Embodiment, although precipitation CA30 was obtained by the precipitator 8, the discharge part 9, the vibration dryer 10, and the discharge part 46, in addition to this, the apparatus structure of 2nd Embodiment as shown in FIG. From this, precipitation CA30 may be obtained. In the second embodiment, there are a precipitator 8, a vibration sieve 61, squeeze rollers 62 and 63, a guide plate 64, a hot air dryer 66 and a pulverizer 67. In the second embodiment, the same constituent members as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The precipitator 8 is configured in substantially the same manner as in the first embodiment. Precipitation CA 30 deposited by the precipitator 8 overflows with the hot water 22 and is discharged from the precipitator 8 to the vibrating sieve 61. In the vibration sieve 61, the precipitation CA30 is received by the sieve body 61a. The warm water 22 passes through the fluid main body 61a and flows into the warm water recovery bowl 61b. And it returns to the warm water storage tank 39 (refer FIG. 1) by the water collection | recovery pipe line 38. FIG.

  The sieve body 61a is vibrated by a vibration mechanism 61c. The precipitated CA 30 is shaken off on the fluid main body 61 a and sent to the squeeze roller 62. The squeeze rollers 62 and 63 pinch the precipitation CA30 from the vertical direction and squeeze out moisture. This water is returned to the hot water storage tank 39 (see FIG. 1) through the hot water recovery tank 61b and the water recovery pipe line 38. Although two squeeze rollers 62 and 63 are provided, one or three or more of these may be used.

  The precipitator 8 and the vibrating screen 61 are arranged in the same sealed tank 59. A solvent recovery line 55 is connected to these sealed tanks 59. As shown in FIG. 1, the methylene claloid 18 recovered via the solvent recovery line 55 is returned to the solvent storage tank 14 via the condenser 56 and the separation tank 57 and circulated for use. Similarly, a solvent recovery pipe 55 is also connected to a hot air dryer 66 and a pulverizer 67 described later, and the methylene claloid 18 is circulated through the solvent recovery pipe 55.

  The precipitated CA 30 exiting the squeeze roller 63 is guided by the guide plate 64 and sent to the hot air dryer 66 by the rotary valve 65. The hot air dryer 66 dries the precipitated CA 30 sent by the rotary valve 65 with hot air. The dried precipitated CA30 is sent to a pulverizer 67, pulverized, and made into a lump of a certain size. The precipitated CA30 after pulverization is packed in a flexible container bag 49.

  In the first embodiment, the doors 40 to 42, 47, and 48 are used to secure the sealing performance of the precipitator 8 and the vibration dryer 10, but instead of this, a rotary valve 65 as shown in FIG. It may be used to ensure these sealing properties.

  Next, the preferable handling form of precipitation CA30 is demonstrated. The precipitated CA30 discharged from the vibration dryer 10 or the hot air dryer 66 is cotton-like and has a low bulk density and is light. In handling with such cotton-like precipitation CAF31, since it is light, it is easy to scatter. In addition, the volume of the cotton-like precipitation CAF 31 to be used during preparation of the dope in the film forming facility is remarkably increased. Therefore, there are inconveniences that the atmosphere environment deteriorates due to scattering, and inconveniences that the sizes of various facilities such as the carrier for the cotton-like precipitation CAF 31 and the dissolution tank 80 become large. In order to eliminate this, the cotton-like precipitation CAF31 is made into granular precipitation CAP32 such as pellets and tablets with a granulator to increase the bulk density. Thereby, the equipment size of dope preparation can be made substantially the same as the conventional one, and the existing equipment can be used. Depending on the form of the precipitation CA30, a cotton-like one is called a cotton-like precipitation CAF31, and a granular one such as a pellet or a tablet is called a granular precipitation CAP32, which is used properly. Since the cotton-like precipitated CAF 31 has a low bulk density and is light, the cotton-like precipitated CAF 31 easily scatters and has a large volume and is difficult to handle, but is easily dissolved in a solvent. Therefore, when the cotton-like handling is possible, the cotton-like precipitation CAF 31 may be handled.

  FIG. 8 is a schematic view of a granulation facility. In the case of online granulation, the cotton-like precipitated CAF 31 is sent to the coarse dryer 110 from either the vibration dryer 10 of FIG. 1 or the hot air dryer 66 or the pulverizer 67 of FIG. The coarse dryer 110 roughly drys the cotton-like precipitated CAF 31 until the moisture content is suitable for granulation. The cotton-like precipitated CAF 31 from the coarse dryer 110 is sent to the wet granulator 112 by the quantitative feeder 111. The wet granulator 112 extrudes the cotton-like precipitation CAF31 to form the granular precipitation CAP32.

  The granular precipitation CAP 32 is sent to the vibration dryer 113. The vibration dryer 113 dries the granular precipitation CAP32 with a heating air of 0.1 m / sec or more and 1 m / sec or less until the water content becomes 0.1% or more and 3% or less while applying vibration to the granular precipitation CAP32. To do. The vibration dryer 113 has basically the same configuration as the vibration dryer 10 shown in FIG.

  Granulation can be performed by either wet granulation or dry granulation, but a wet granulation method that enables continuous and efficient granulation is preferable.

  In order to perform wet granulation, the target moisture content needs to be about 20% to 150% (dry basis). Hereinafter, the description of the dry amount standard is omitted with respect to the moisture amount, but the moisture amount is expressed based on the dry amount reference. This value is a percentage obtained by {(MB−MA) / MA} × 100, where MB is the mass of the precipitated CA30 as the object to be measured and MA is the mass after the precipitated CA30 is almost completely dried. . The cotton-like precipitation CAF 31 discharged and dehydrated by the vibration dryer 10, the hot air dryer 66 or the pulverizer 67 has a water content of about 200%, and the coarse dryer 110 has a water content of about 20% to 150%. To do. Of course, when the cotton-like precipitated CAF 31 can be dried to a moisture content of about 20% or more and 150% or less by the vibration dryer 10 or the hot air dryer 66, the coarse dryer 110 can be omitted.

  Any method may be used for rough drying of the cotton-like precipitated CAF 31 as long as it is a dry method. Particularly preferred is an indirect heating type coarse dryer 110 such as a paddle dryer or a rotary kiln having a low wind speed and less scattering of the cotton-like precipitated CAF 31. Similarly, a direct heating type coarse dryer using a vibration dryer having a low wind speed can also be used. However, in the case of a vibration dryer, there is a drawback that if the wind speed is increased in order to increase the drying efficiency, the amount of the flocculent CAF 31 is scattered and the collection facility is increased.

  When the cotton-like precipitated CAF31 is roughly dried and the water content becomes 20% or more and 150% or less, using a wet granulator (for example, Dalton F-5 type wet granulator) 112, Granulate. The wet granulator 112 rotates a roller on the disk die to sandwich the cotton-like precipitation CAF 31 between the disk die and the roller, and pressurizes and extrudes from the hole of the disk die at 15 MPa and 20 MPa. A knife cutter is provided on the back surface of the disk die, and the extruded product is cut to an appropriate length and granulated into a granular precipitation CAP32.

  While the bulk density of the flocculent precipitate CAF31 is about 0.03 or more and 0.05 or less, the granular precipitate CAP32 has a bulk density of 0.1 or more, and the bulk density is one digit or more higher than that of the flocculent precipitate CAF31. Become. For this reason, it becomes easy to handle, and the existing equipment can be used as the dope preparation equipment.

  The granular precipitated CAP32 preferably has a moisture content of 20% or more and 150% or less, and is preferably subjected to final drying so that the moisture content is 0.1% or more and 3% or less for storage. In this final drying, since the bulk density of the granular precipitated CAP32 is high, there is a concern of breaking when subjected to a strong impact. Therefore, it is preferable to dry by a low impact drying method so that the granular precipitation CAP32 is not broken.

  As a low-impact drying method, a method of directly heating with hot air like the vibration dryer 113 is preferable because the granulated product is not destroyed. On the other hand, in the indirect heating method in which the outer wall such as a paddle dryer or rotary kiln is heated, the granular precipitation CAP32 may be destroyed, which is not preferable as a final drying method.

  As described above, by increasing the bulk density from the cotton-like precipitation CAF31 having a bulk density of about 0.03 to 0.05, to a granular precipitation CAP32 having a bulk density of about 0.1 to about 0.5, Handling characteristics are improved, and a dope can be easily prepared. Moreover, the existing dope melting equipment can be used by improving the bulk density, which is preferable from the viewpoint of equipment efficiency. Further, by performing final drying with the vibration dryer 113 to obtain a dry granular precipitation CAP32a having a moisture content of 0.1% or more and 3% or less, the moisture content suitable for storage can be obtained.

[Example 1]
Table 1 below compares the precipitated CA purified by the method of the present invention (Example 1) and the conventionally used raw material CA (Comparative Example 1). In Example 1, the solubility limit (solid content concentration) when cellulose acylate was dissolved in a mixed solvent of methylene claloid and methanol was examined. In Comparative Example 1, about 17% was the limit. In Example 1, it is about 24%, which indicates that the solubility limit is increased. In addition, as a necessary process, the heat concentration step was necessary in Comparative Example 1, but such a step is not necessary in Example 1, and can be achieved by dissolution only with a dissolution tank. In the subsequent casting step, both Example 1 and Comparative Example 1 were cast at a solid content concentration of about 20%.

[Example 2]
The casting dope according to Example 1 and the casting dope according to Comparative Example 1 (both solid concentration is about 20%) were cast with the equipment shown in FIG. 3 to obtain a film. A film formed by casting dope according to Example 1 (Example 2), a film formed by casting dope according to Comparative Example 1 and formed by unfiltered material (Comparative Example 2), and a casting dope according to Comparative Example 1. The number of foreign matters in one square mm (mm ² ) of the obtained film was examined separately for each size of foreign matter with respect to the film formed with the filtrate (Comparative Example 3).

  When the number per unit area of a small foreign material of less than 10 μm, a medium foreign material of 10 μm or more and less than 30 μm, and a large foreign material of 30 μm or more was examined, the unfiltered dope of Comparative Example 2 left the foreign material contained in the raw material CA intact. Appeared in the product, about 5 small foreign particles, about 30 medium foreign particles, and about 10 large foreign particles. When the result of Comparative Example 2 was used as a reference (100%), in Example 2, the number of foreign matters per unit area was about 3% or less compared to Comparative Example 2 in any size. Further, in the filtered dope of Comparative Example 3, each size foreign material was at a level of about 10%. From the above results, it can be seen that, as in Example 2, the film obtained from the cast dope once dissolved in a solvent and filtered has almost no foreign matter.

  Table 2 shows the relationship between the average particle diameter of auxiliary agent when carrying out auxiliary agent filtration and the absolute filtration diameter obtained by filtration based on the particle size. The average particle diameter of auxiliary agent is 60 μm, 20 μm, 10 μm. Thus, it can be seen that as the size is reduced, the absolute filtration diameter is correspondingly reduced to 15 μm, 10 μm, 5 μm, and smaller foreign matters can be removed.

Table 3 shows the method of polymer precipitation by hot water contact according to the present invention (Example 3) and the method of polymer precipitation by hot air drying (Comparative Example 4). Comparative Example 4 shows the heat transfer coefficient (W / mK). Is 0.06, whereas in Example 3, the efficiency is 0.66, and the efficiency based on hot air drying is 22 times higher than that of hot air drying. Further, the contact area (square m (m ² ) / kg dope) is 2.26 when the thickness is 300 μm in Comparative Example 4, and 15.4 when the diameter is 300 μm in Example 3, The efficiency based on hot air drying is 6.8 times the efficiency of hot air drying. Therefore, when these are integrated, it becomes 22 × 6.8 times, which is about 150 times the efficiency improvement with respect to the hot air drying, and it can be seen that the hot water contact greatly improves the drying speed as compared with the conventional hot air drying.

DESCRIPTION OF SYMBOLS 5 Polymer refinement | purification equipment 6 Dissolution tank 7 Dope supply line 8 Precipitator 9 Discharge part 10 Vibratory dryer 11 Pump 12 Filter 13 Solvent supply line 14 Solvent storage tank 17 Raw material CA (cellulose acylate)
21 Dilute Dope 22 Hot Water 25 First Nozzle 26 Second Nozzle 28 Hot Water Supply Pipe 30 Precipitated CA (Cellulose Acylate)
31 Cotton-like precipitation CAF
32 Granular precipitation CAP
33, 34 Squeeze roller 37 Overflow recovery part 38 Water recovery line 39 Hot water storage tank 40-42 Door 51 Water supply line 55 Solvent recovery line 56 Condenser 57 Separation tank 60 Pure water storage tank 68 Solution film forming equipment 69 Mixing device 70A , 70B Dissolution unit 71 Addition unit 80 Dissolution tank 82 Static mixer 83 Dynamic mixer 78 Casting die 86 Addition nozzle 88 Additive liquid feed section 110 Coarse dryer 112 Wet granulator 113 Vibration dryer

Claims (22)

A dissolution step of dissolving a polymer in a solvent to obtain a polymer solution;
A filtration step of filtering the polymer solution;
A polymer precipitation step of depositing the polymer by spraying the polymer solution that has passed through the filtration step to a liquid that is incompatible with the polymer and the solvent and heated to a boiling point or higher of the solvent, and evaporating the solvent A polymer purification method comprising:   The polymer purification method according to claim 1, wherein the polymer solution concentration in the dissolving step is 2% by mass or more and 19% by mass or less.   The polymer purification method according to claim 1 or 2, wherein an absolute filtration accuracy in the filtration step is 2 µm or more and 30 µm or less.   The polymer purification method according to any one of claims 1 to 3, wherein the solvent is a single solvent.   The polymer purification method according to claim 4, wherein the polymer is cellulose acylate, the solvent is methylene claloid, and the liquid is water.   The polymer purification method according to claim 5, wherein the temperature of the cellulose acylate solution in the polymer precipitation step is 20 ° C to 120 ° C, and the water is 40 ° C to 100 ° C. Following the polymer precipitation step, a rough drying step of roughly drying the precipitated polymer,
A wet granulation step of wet granulating the precipitated polymer that has undergone the coarse drying step;
The polymer purification method according to any one of claims 1 to 6, further comprising a final drying step of finally drying the precipitated polymer that has undergone the wet granulation step.   The polymer purification method according to claim 7, wherein the water content of the precipitated polymer is set to 20% to 150% in the rough drying step, and the water content of the precipitated polymer is set to 0.1% to 3% in the final drying step. .   A cotton-like precipitated polymer obtained by the polymer purification method according to any one of claims 1 to 6.   A granular precipitated polymer obtained by the polymer purification method according to claim 7 or 8. A first polymer solution production apparatus having a dissolution tank, a pump, and a filter is used to dissolve the precipitated polymer obtained by the polymer purification method according to any one of claims 1 to 8 in a solvent and A first step of making a polymer solution;
Using the second polymer solution production apparatus having a dissolution tank, a pump, and a filter, the precipitated polymer obtained by the polymer purification method according to any one of claims 1 to 8 is dissolved in a solvent and used for the first type A second step of making a polymer solution for a second variety having a composition different from that of the polymer solution;
An addition step of adding an additive solution mixed with an additive in-line to the polymer solution obtained from one of the first step and the second step;
A casting step of casting the polymer solution to which the additive solution is added as a casting dope from a casting die to a casting support to form a casting film;
A drying step of peeling off the casting membrane from the casting support and drying,
A solution casting method in which the polymer solution from one of the first step and the second step is switched to the other polymer solution of the first step and the second step, and the product type is continuously switched. .   In the addition step, the additive liquid for the first variety and the additive liquid for the second variety are prepared using a plurality of additive liquid storage tanks, and these are switched and fed, and added in-line. Item 11. The solution casting method according to Item 11. A dissolution tank for dissolving a polymer in a solvent to obtain a polymer solution;
A filter for filtering the polymer solution;
A polymer precipitator that contains a liquid that is incompatible with the polymer solution and is heated above the boiling point of the solvent, and that sprays the polymer solution from the dissolution tank toward the liquid;
And a recovery device for recovering the polymer precipitated by the polymer precipitator from the liquid.   The polymer purification equipment according to claim 13, wherein the dissolution tank has a polymer solution concentration of 2% by mass or more and 19% by mass or less.   The polymer purification equipment according to claim 13 or 14, wherein an absolute filtration accuracy of the filter is 2 µm or more and 30 µm or less.   The polymer purification equipment according to any one of claims 13 to 15, wherein the solvent is a single solvent.   The polymer purification equipment according to claim 16, wherein the polymer is cellulose acylate, the solvent is methylene claloid, and the liquid is water.   The polymer purification equipment according to claim 17, wherein the temperature of the cellulose acylate solution in the polymer precipitator is 20 ° C or higher and 120 ° C or lower, and the water is 40 ° C or higher and 100 ° C or lower. A coarse dryer for coarsely drying the precipitated polymer collected by the collector;
A wet granulator that wet-forms the precipitated polymer that has passed through the coarse dryer;
The polymer purification equipment according to any one of claims 13 to 18, further comprising a final dryer for final drying of the precipitated polymer that has passed through the wet granulator.   20. The polymer purification equipment according to claim 19, wherein the coarse dryer has a water content of the precipitated polymer of 20% to 150% and the final dryer has a water content of the precipitated polymer of 0.1% to 3%. . Polymer purification equipment according to any one of claims 13 to 20,
A plurality of dissolution apparatuses having a dissolution tank for dissolving the precipitated polymer obtained from the polymer purification equipment in a solvent, a pump for sending the polymer solution from the dissolution tank, and a filter for filtering the polymer solution from the pump;
A plurality of additive liquid storage tanks storing the additive liquid, a liquid feeding section for selectively sending the additive liquid from these additive liquid storage tanks, and an additive from the liquid feeding section to the polymer solution from the dissolution apparatus An addition device having an in-line addition section for mixing;
A casting apparatus that casts the polymer solution to which the additive solution has been added as a casting dope, to a traveling support, and forms a casting film on the support;
A solution casting apparatus comprising: a film drying unit that dries the cast film peeled off from the casting apparatus.   The additive device uses a plurality of additive liquid storage tanks to create an additive liquid for the first product type and an additive solution for the second product type, and switches between these to send and add in-line. The solution casting apparatus according to claim 21.

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