TWI693996B - Solution film making method - Google Patents

Abstract

The present invention provides a solution supply method and device, and a solution film-making method, which suppresses the leakage or cavitation phenomenon of a supply pump disposed downstream of a delivery pump of a polymer solution.

The paint supply device 13 includes a tank 17, a delivery pump 18, a pressure gauge 22, a supply pump 21, an adjustment valve 23, and a controller 24, and supplies the paint 11 to the film manufacturing device 14. The paint 11 in the tank 17 is sent out by the delivery pump 18. A part of the paint 11 sent out is sent back to the tank 17 through the second pipe L2. The paint 11 supplied to the casting die 28 by the supply pump 21 is discharged from the casting die 28 to form the film 12. The primary-side pressure of the supply pump 21 is controlled by the controller 24 to adjust the opening of the adjustment valve 23 based on the detection result of the pressure gauge 22 to thereby control within the set range.

Description

Solution film making method

The invention relates to a solution supply method and device, and a solution film forming method.

The solution film-making method is a method of manufacturing a thin film, which casts a polymer solution in which a polymer is dissolved in a solvent on a casting support to form a casting film, and peels off the casting film in a state containing a solvent Next, a film is formed and the film is dried. When a long thin film is manufactured by this method, the polymer solution is discharged from the casting die toward the support.

The polymer solution is prepared by dissolving the polymer in a solvent, and is stored in a storage part such as a tank until it is used. The storage part and the casting mold are connected via piping, and the polymer solution is sent out from the storage part toward the casting mold by a pump for sending out (sending pump).

The flow rate of the polymer solution supplied to the casting die changes the thickness of the film. Therefore, it is required to suppress the flow rate of the polymer solution supplied to the casting die as much as possible during the production of the long film. In addition, when switching the manufacturing object of the film to another type having a different thickness, it is required to adjust the flow rate of the polymer solution supplied to the casting die so as to surely exhibit the thickness of the film after the switching.

[Prior Technical Literature]

For example, in the method disclosed in Japanese Patent Laid-Open No. 2008-068440, in order to switch the manufacturing object of the film to another type with a different thickness without stopping the film manufacturing line, two delivery pumps are arranged in parallel in the storage section Downstream, switch from one delivery pump to the other delivery pump. The method of Japanese Patent Laid-Open No. 2008-068440 is to gradually reduce the flow rate of one of the delivery pumps and gradually increase the flow rate of the other delivery pump during the period from the start to the end of the switching, so as to maintain the flow rate of the two delivery pumps Roughly fixed. In addition, by controlling the flow rate of the return pipe extending from the downstream outlet pipe with two parallel pipes in which the delivery pumps are respectively arranged to the upstream inlet pipe, the pressure fluctuation of the outlet pipe is suppressed.

In addition, in the case where a plurality of films having different compositions are switched and manufactured, a plurality of polymer solutions having different compositions are switched and used. For example, the method for manufacturing a thin film contained in Japanese Patent Application Laid-Open No. 2010-240875, for example, stores first and second polymer solutions with different compositions in storage units connected in parallel, by switching the two storage units The delivery pumps provided downstream of each switch from the first polymer solution to the second polymer solution. In each of the parallel pipes provided with the storage section and the delivery pump, a return pipe for returning the polymer solution to the upstream side is provided. In the method of Japanese Patent Laid-Open No. 2010-240875, one of the valves provided for each of these two return pipes is fully opened, and the other is gradually reduced, thereby adjusting the supply to the casting die Flow rate while switching the supply pump.

However, even if the polymer solution is sent out of the accumulation section at a fixed flow rate by the delivery pump as in Japanese Patent Laid-Open No. 2008-068440 and Japanese Patent Laid-Open No. 2010-240875, the piping up to the casting die will still be There is a pressure loss, and this pressure loss will change over time. The flow rate of the polymer solution supplied to the casting die will change due to this pressure loss and the effect of the change over time, which in turn will affect the thickness of the film. In addition, in the method of Japanese Patent Laid-Open No. 2010-240875, even if the return piping is used, the pressure loss in the piping up to the casting die and the change cannot be coped with. Therefore, a pump (supply pump) for supplying the polymer solution to the casting die at a fixed flow rate is provided downstream of the delivery pump, which facilitates the production of a film with a desired thickness.

However, when the feed pump is used, the polymer solution may leak at the gear part of the feed pump, for example, or bubbles may be mixed into the polymer solution in the feed pump (so-called cavitation) ).

Therefore, an object of the present invention is to provide a solution supply method and apparatus, and a solution film forming method, which suppress the leakage or cavitation of the polymer solution at the supply pump.

The solution supply method of the present invention includes a delivery step (step A), a supply step (step B), a pressure detection step (step C), a return step (step D), and a pressure control step (step E), and polymerizes The substance solution is supplied to the discharge portion where the polymer solution in which the polymer is dissolved in the solvent is discharged. Step A is to send out the polymer solution stored in the storage part by the sending pump; Step B is to send the polymer solution sent from the storage part by the supply pump provided downstream of the sending pump at a fixed flow rate Supply to the discharge part; Step C is to detect the pressure on the primary side of the supply pump; Step D is to branch from the first pipe extending from the delivery pump to the supply pump and connect to the storage part Piping, part of the polymer solution from the delivery pump is returned to the storage section; step E is to adjust the opening of the adjustment valve provided in the second pipe according to the detection result of step C, and control the pressure on the primary side to Within a preset fixed range.

The above solution supply method is particularly effective when the discharge part is a casting die of a thin film manufacturing apparatus that manufactures a thin film by solution film formation.

When the solution supply method further includes an addition step (step F), the degree of hardening is large. Step F is to add an additive solution in which the additive contained in the film is dissolved in the solvent, and add it to the polymer solution in the first pipe through the third pipe connected to the first pipe.

When the flow rate of the additive liquid is adjusted by the addition valve provided in the third pipe, the effect of the solution supply method described above is high.

When the additive solution and the polymer solution have the same solid content concentration, the effect of the solution supply method described above is also high.

When the type of the manufactured thin film is switched, even if the type of the additive liquid is switched, the effect of the above solution supply method is still high.

The solution supply device of the present invention includes a reservoir, a delivery pump, a first pipe, a supply pump, a pressure gauge, a second pipe, an adjustment valve, and a controller, and supplies a polymer solution to a solvent in which a polymer is dissolved The discharge part where the polymer solution is discharged. The storage section stores the polymer solution; the delivery pump sends the polymer solution from the storage section; the first piping system guides the polymer solution from the storage section; the supply pump system is provided downstream of the delivery pump via the first piping, The polymer solution is supplied to the discharge portion at a fixed flow rate; the pressure gauge detects the pressure on the primary side of the supply pump; the second piping is branched from the first piping and connected to the storage portion, connecting the A part of the polymer solution is sent back to the storage part; the adjustment valve is provided in the second pipe to adjust the return flow rate of the polymer solution sent back to the storage part; the controller adjusts the opening degree of the adjustment valve according to the detection result of the pressure gauge. This controls the aforementioned primary pressure within a preset fixed range.

The above solution supply device is particularly effective when the discharge part is a casting die of a thin film manufacturing apparatus that manufactures a thin film by solution film formation.

It is preferable to have a third piping for adding an additive solution in which the additive contained in the film is dissolved in the solvent to the polymer solution. The third piping is connected to the aforementioned first piping.

The third piping system is preferably provided with an addition valve for adjusting the flow rate of the additive liquid.

When the solid concentration of the additive liquid and the polymer solution are equal, the effect of the solution supply device is high.

In the case where the third piping guides the first additive liquid and the second additive liquid added to the polymer solution in accordance with the type of the manufactured thin film, the effect of the solution supply device is high.

The solution film forming method of the present invention includes the aforementioned step A, supply step (step G), aforementioned step C, casting step (step H), peeling step (step I), drying step (step J), and aforementioned step D And, in the aforementioned step E, a polymer solution in which a polymer is dissolved in a solvent is continuously discharged from a casting die and dried to produce a film. Step G is to supply the polymer solution sent from the accumulation part to the casting die at a fixed flow rate by the supply pump provided downstream of the delivery pump; Step H is to continuously discharge the polymer solution from the casting die to Casting the support to form a casting film; Step I peels the casting film from the casting support; Step J peels it off in Step I The resulting film dries.

The solution film-forming method described above has a high effect when the step F is provided, and has a particularly high effect when the flow rate of the additive liquid is adjusted by an addition valve provided in the third piping. In addition, the above-mentioned solution film forming method has a high effect when the additive solution and the polymer solution have the same solid content concentration, or when the type of the manufactured thin film is switched, when the type of the additive liquid is switched.

According to the present invention, it is possible to suppress the occurrence of leakage or cavitation of the polymer solution in the supply pump that supplies the polymer solution to the casting die at a fixed flow rate.

10: Solution film making equipment

11: Paint

12: Film

13: Paint supply device

14: Film manufacturing equipment

17: tank body

18: send out the pump

21: Supply pump

21a: First supply pump

21b: Second supply pump

21c: Third supply pump

22: pressure gauge

23: Adjustment valve

24: controller

25, 25a, 25b, 25c: filter

28, 72: Casting mode

28a: spit out

31: Casting unit

32: stenter

33: Roll dryer

34: Coiler

40: belt

41: Roller

43: Cast film

46: clip

47: Blower

48: Roller

51: Paint supply device

52: benchmark paint

53: Additive solution

56: Casting paint

57: static mixer

71: Paint supply device

72a: spit out

73: Valve

58, 87, 88: Add valve

L1~L3: First to third piping

75, 76: first and second cast coating

83: The first static mixer

84: Second static mixer

91~93: Valve

L4: Fourth piping

LB1~LB4: First branch piping to fourth branch piping

Those with ordinary knowledge in this technical field should be able to easily understand the above objects and advantages by referring to the drawings and reading the detailed description of the preferred embodiments.

Fig. 1 is a schematic diagram of a solution film-forming apparatus embodying the present invention.

Fig. 2 is a flowchart of controlling the primary pressure of the supply pump.

3 is a schematic diagram of a solution supply device according to another embodiment of the present invention.

4 is a schematic diagram of a solution supply device according to another embodiment of the present invention.

[Forms for carrying out the invention]

<First Embodiment>

The solution film forming apparatus 10 shown in FIG. 1 is an apparatus for manufacturing a thin film 12 from a dope 11 and includes a paint supply device 13 and a thin film manufacturing device 14. The paint 11 is a polymer solution in which a polymer is dissolved in a solvent. In the present embodiment, the polymer system uses TAC (cellulose triacetate); the solvent system uses a mixture of methylene chloride, methanol, and butanol, but the polymer and the solvent are not limited thereto. The polymers and solvents that can be used in the present invention will be described in detail later. The paint 11 may contain various additives such as plasticizers, ultraviolet absorbers (hereinafter referred to as UV absorbers), retardation control agents, and the like.

The paint supply device 13 is a device for continuously supplying the paint 11 to the film manufacturing device 14. The paint supply device 13 includes a tank 17, a delivery pump 18, a supply pump 21, a pressure gauge 22, an adjustment valve 23, and a controller 24. The paint supply device 13 is preferably further provided with a filter 25 as in this embodiment. In this embodiment, the filter 25 is connected to the casting die 28 of the film manufacturing apparatus 14. Furthermore, the filter 25 can also be arranged further upstream than the pressure gauge 22.

The tank 17, the delivery pump 18, the pressure gauge 22, the supply pump 21, the filter 25, and the casting die 28, which are sequentially arranged from the upstream side, are connected by the first pipe L1. The first pipe L1 is branched between the delivery pump 18 and the pressure gauge 22, and the second pipe L2 branched from the first pipe L1 is connected to the tank 17. The adjustment valve 23 is provided in this second pipe L2. In the following description, the position where the second pipe L2 branches from the first pipe L1 is referred to as a branch position, and the symbol PB is given.

The tank 17 is a storage part in which the paint 11 is stored. This tank 17 also functions as an independent part, which makes the flow rate of the paint 11 sent from the tank 17 (hereinafter referred to as the delivery flow rate) independent of the flow rate of the paint 11 in the second pipe L2 (hereinafter referred to as the return flow rate).

The delivery pump 18 is a pump for sending the paint 11 from the tank 17. The delivery pump 18 applies pressure to the paint 11 and sends it out (pressure delivery). In this embodiment, a gear pump is used for the delivery pump 18 series. However, the delivery pump 18 is not limited to this, and may be, for example, a diaphragm pump, a canned pump, or the like. The flow path of the paint 11 sent from the tank 17 by the sending pump 18 is divided at the branch position PB, and leads to the first pipe L1 extending toward the feed pump 21 and the film manufacturing apparatus 14 and the first pipe branched from the first pipe L1 Second piping L2.

The supply pump 21 is a pump for supplying the paint 11 to the casting die 28 at a fixed flow rate. The supply pump 21 uses a gear pump. With this, the supply pump 21 supplies the paint 11 guided by the delivery pump 18 in the first pipe L1 to the casting die 28 at a fixed flow rate. The flow rate of the paint 11 (hereinafter referred to as the supply flow rate) supplied to the casting die 28 by the supply pump 21 is determined based on the amount of paint 11 discharged from the casting die 28 per unit time. Hereinafter, the amount of paint 11 discharged from the casting die per unit time is referred to as a discharge flow rate.

The filter 25 is used to filter the paint 11 conveyed by the supply pump 21 and remove foreign substances from the paint 11. The filter 25 uses a metal filter in this embodiment. However, the filter 25 is not limited to this, and for example, filter paper, a leaf filter, or the like may be used. The paint 11 that has passed through the filter 25 is supplied to the casting die 28 of the film manufacturing apparatus 14.

The second pipe L2 branched from the first pipe L1 downstream of the delivery pump 18 is a pipe for returning a part of the paint 11 from the delivery pump 18 to the tank 17. The adjustment valve 23 is a valve for adjusting the return flow rate (that is, the flow rate of the paint 11 returned to the tank 17). The adjustment valve 23 can adjust the opening degree, and when it is set to open, a part of the paint 11 of the first pipe L1 is returned to the tank 17, and the return flow rate is adjusted by adjusting the opening degree. Also, the adjustment valve The 23 series outputs the opening degree to the controller 24.

The pressure gauge 22 is used to detect the pressure PA on the primary side of the supply pump 21 (that is, the pressure of the paint 11 entering the supply pump 21 ). Hereinafter, the pressure on the primary side of the supply pump 21 is referred to as the primary pressure. The pressure gauge 22 is provided between the branch position PB and the supply pump 21. As such, in this embodiment, the pressure gauge 22 is provided on the first pipe L1 upstream of the supply pump 21, but it is not limited to this aspect. For example, the pressure gauge 22 may be provided inside the supply pump 21.

The controller 24 is used to control the primary pressure PA within a preset fixed range (hereinafter referred to as a set range) PS. The controller 24 includes a memory unit (not shown) and a calculation unit (not shown). The memory section memorizes the opening degree of the adjustment valve 23 and the input setting range PS described above. The calculation unit calculates the opening degree of the adjustment valve 23 that causes the primary pressure PA to fall within the setting range PS based on the set range PS stored in the memory unit and the detection result of the pressure gauge 22, and then adjusts the adjustment valve 23. Specifically, the difference between the set range PS stored in the storage unit and the detection result of the pressure gauge 22 is obtained, and the opening degree of the adjustment valve 23 that causes the primary pressure PA to fall within the set range PS is calculated from the difference, and further Adjust the adjustment valve 23. The controller 24 adjusts the opening of the adjustment valve 23 based on the detection result of the pressure gauge 22 by the memory section and the calculation section so that the primary pressure PA falls within the set range PS.

The film manufacturing apparatus 14 includes a casting unit 31, a tenter 32, a roll dryer 33, and a winder 34 in this order from the upstream side. The casting unit 31 includes a belt 40 as a casting support body formed in a ring shape, a pair of support belts 40 and a roller 41 that travels in the longitudinal direction, a casting die 28, and a peeling roller 42. At least one of the pair of rollers 41 rotates in the circumferential direction by Rotating here, the belt 40 wound around the pair of rollers 41 thus circulates in the longitudinal direction. The casting die 28 is arranged above one of the pair of rollers 41 in this example, but may be arranged above the belt 40 between one of the pair of rollers 41 and the other.

The casting die 28 is a discharge portion that continuously discharges the supplied paint 11 from the discharge port 28a facing the belt 40. By continuously discharging the paint 11 to the traveling belt 40, the paint 11 is cast on the belt 40, and a casting film 43 is formed on the belt 40. In FIG. 1, a symbol PC is given to a position where the coating material 11 comes into contact with the roller 41 to start forming the casting film 43 (hereinafter referred to as a casting position).

The pair of rollers 41 is equipped with a temperature controller (not shown) for adjusting the temperature of the peripheral surface. The temperature of the casting film 43 can be adjusted via the belt 40 by the roller 41 whose peripheral surface temperature is adjusted. In the case of heating the cast film 43 and promoting drying to harden it (gelatinization), a so-called dry gelatinization method, the temperature of the peripheral surface of the roller 41 is set within a range of, for example, 10° C. or higher and 40° C. or lower. In addition, when the casting film 43 is cooled to be hardened, that is, a so-called cooling gelation method, the temperature of the peripheral surface of the roller 41 is set within a range of -10°C or more and 5°C or less. By such gelatinization, the casting film 43 is hardened to the extent that it can be transported.

Furthermore, instead of the belt 40, a roll (not shown) may be used for the casting support. In this case, the cast film 43 is formed on the peripheral surface by providing a drive mechanism on the roller and rotating it in the circumferential direction. When a roller is used as the casting support, the roller system may be provided with a temperature controller (not shown) for adjusting the temperature of the peripheral surface, and the temperature of the casting film 43 may be adjusted by adjusting the temperature of the peripheral surface of the roller.

Regarding the paint 11 (so-called bead) from the casting die 28 to the belt 40, a decompression chamber (not shown) is provided upstream of the belt 40 in the traveling direction. The decompression chamber sucks the air in the upstream side of the discharged paint 11 to decompress the area. In addition, a blower (not shown) may be provided to face the belt 40 and promote drying of the casting film 43.

After the casting film 43 is hardened on the belt 40 to the extent that it can be transported to the tenter 32, it is peeled off from the belt 40 in a state containing a solvent. The peeling roller 42 is a roller for continuously peeling the casting film 43 from the belt 40. The peeling roller 42 supports the film 12 formed by peeling the tape 40 from below, for example, and keeps the peeling position PP of the cast film 43 peeling from the tape 40 constant. The peeling method may be any method of pulling the film 12 downstream, or a method of rotating the peeling roller 42 in the circumferential direction.

In the case of the dry gelatinization method, for example, the cast film 43 is peeled off while the solvent content of the cast film 43 is in the range of 20% by mass or more and 50% by mass or less. In addition, in this specification, the solvent content (unit: %) is a dry amount reference value, specifically, when the mass of the solvent is x and the mass of the film 12 is y, the formula {x/( yx)}×100 The calculated percentage.

The casting unit 31 forms the thin film 12 from the paint 11 as described above. The belt 40 is circulated through the casting position PC and the peeling position PP, and the casting of the paint 11 and the peeling of the casting film 43 are repeatedly performed.

The conveyance path between the casting unit 31 and the tenter 32 may also be equipped with a blower (not shown) for promoting the drying of the film 12. The film 12 formed by peeling is guided by the tenter 32. The tenter 32 includes a clip 46 that holds the side of the long film 12 and a pair of rails (not shown) to And chain (not shown). A pin plate (not shown) can also be used instead of the clip 46, which arranges a plurality of pins (not shown) in a posture standing on the top of the table, piercing each pin on the side of the film 12部，以maintaining the film 12.

The rail system is provided on the side of the transport path of the film 12, and a pair of rail systems are arranged separately. The chain is erected on the driven sprocket and the passive sprocket (not shown), and is installed in such a way as to move freely along the track. The clip 46 is installed on the chain at a predetermined interval, and the clip 46 is cyclically moved along the track by the rotation of the driving sprocket. The clip 46 starts holding the film 12 guided near the entrance of the tenter 32, moves toward the exit, and releases the hold near the exit. The clip 46 that has been released is moved again near the entrance to hold the newly guided film 12. In this way, the clip 46 grasps each side portion of the film 12 and conveys it in the longitudinal direction.

A blower 47 is provided above the conveying path of the film 12 in the tenter 32. An outlet (not shown) through which the drying gas flows out is formed on the lower surface of the blower 47, and the drying gas is blown toward the passing film 12. Furthermore, a blower having the same structure may be provided below the transport path of the film 12.

The roller dryer 33 is equipped with a plurality of rollers 48 and an air conditioner (not shown). The plural support rollers 48 support the film 12 on the peripheral surface. The film 12 is wound around the roller 48 and transported. The air conditioner adjusts the internal temperature, humidity, etc. of the roller dryer 33. The winder 34 is used to wind the film 12 into a roll shape.

In the present embodiment, the aforementioned setting range PS for the primary-side pressure PA is obtained before starting to manufacture the thin film 12, and an example of the method for obtaining the same is as follows. In addition, the lower limit value of the setting range PS is set in advance P1 and the upper limit are set to P2. That is, the range PS is set to a range from P1 to P2.

The first pipe L1 between the supply pump 21 and the filter 25 is branched, and this branched pipe (not shown) is connected to the tank 17. The branch pipe is provided with an observation window for observing whether the paint 11 flowing in the internal flow path has bubbles. A valve (not shown) is provided between the branch position of the first pipe L1 provided with this branch pipe and the filter 25, and this valve and the adjustment valve 23 are closed. The delivery pump 18 and the supply pump 21 are driven, and the flow rate of the paint 11 supplied by the supply pump 21 is fixed, the delivery flow rate is changed, and the primary pressure PA is detected for each delivery flow rate. The paint 11 flowing during the detection is sent back to the tank 17 through the branch piping. As long as the flow rate of the paint 11 supplied by the supply pump 21 is constant during the detection, for example, the supply flow rate may be fixed, or the flow rate different from the supply flow rate may be fixed.

When the primary pressure PA becomes too low and the paint 11 flowing in the branch piping is found to have bubbles, set the primary pressure PA at this time to PAL and PAL×1.1 to the lower limit P1; the primary side When the pressure PA becomes too high, for example, when the paint 11 leaks, for example, in the gear portion of the supply pump 21, the primary pressure PA at this time is set to PAH, and PAH×0.9 is set to the upper limit value P2. In this way, the delivery flow rate is gradually lowered, and the value obtained by multiplying the primary pressure PA (that is, PAL) of the paint 11 at which the bubbles are confirmed by 1.1 is set to P1; the delivery flow rate is gradually increased, and the paint 11 is gradually increased. The value obtained by multiplying the primary pressure PA (that is, PAH) by which the supply pump 21 starts to leak by 0.9 is set to P2. The setting range PS is obtained in the above manner. Furthermore, the P1 and P2 systems differ according to the paint 11 used. Therefore, it is necessary to set the paint 11 to be used. Therefore, when a plurality of different kinds of paints 11 that are different from each other are to be switched and supplied to the film manufacturing apparatus 14, P1 and P2 are set for each paint 11 used. In addition, P1 and P2 differ according to the supply pump used, and therefore, it is set for each supply pump 21 used.

The lower limit P1 of PS is preferably PAL×1.15, and the upper limit P2 is preferably PAH×0.85.

The function of the above configuration will be described. The paint 11 prepared in advance and stored in the tank 17 is sent out from the tank 17 at a fixed sending flow rate (feeding step) by the sending pump 18 and flows through the first pipe L1. The paint 11 to be sent out is divided at the branch position PB into paint that is led to the film manufacturing apparatus 14 in the first pipe L1 and paint that is led to the tank 17 in the second pipe L2 (return step). The paint 11 led to the casting die 28 in the first pipe L1 is supplied to the casting die 28 of the film manufacturing apparatus 14 at a constant flow rate through the filter 25 by the supply pump 21 (supply step). By using the supply pump 21, the pressure loss of the first pipe L1 is suppressed compared to the case where the paint is conveyed only by the delivery pump 18, so the paint 11 is supplied to the casting die 28 at a fixed flow rate with higher accuracy . The filter 25 removes foreign materials from the paint 11 by filtering the paint 11 flowing to the casting die 28.

As shown in FIG. 2, the pressure gauge 22 detects the primary pressure PA (pressure detection step) and outputs the detection result to the calculation unit of the controller 24. The calculation unit of the controller 24 compares the input detection result with the aforementioned setting range PS memorized by the storage unit, and checks whether the primary pressure PA of the detection result is within the setting range PS, that is, P1 or more and P2 or less. in When the primary pressure PA is within the set range PS, the number of rotations of the delivery pump 18 and the supply pump 21 and the opening degree of the adjustment valve 23 are maintained.

When the primary pressure PA is outside the set range PS, the controller 24 checks whether the primary pressure PA is higher than the upper limit value P2 or lower than the lower limit value P1. When the primary pressure PA is higher than the upper limit value P2 (PA>P2), if the opening degree of the adjustment valve 23 is not fully open, the controller 24 will adjust the opening degree of the adjustment valve 23 to be greater than now. The return flow rate becomes larger because the opening degree of the adjustment valve 23 becomes larger, and the flow rate of the paint 11 flowing toward the supply pump 21 becomes smaller, so the primary pressure PA decreases. The lowered primary pressure PA is detected again by the pressure gauge 22. In the case where the new detection result is within the set range PS, the number of revolutions of the delivery pump 18 and the supply pump 21 and the opening of the adjustment valve 23 are maintained The degree remains unchanged. On the other hand, in the case where the new detection result is higher than the upper limit value P2 (PA>P2) and the opening of the adjustment valve 23 is not fully open, the controller 24 adjusts the opening of the adjustment valve 23 to be greater, The primary pressure PA of the supply pump 21 is lowered. As such, in the case where the primary pressure PA is higher than the upper limit value P2 and the opening of the adjustment valve 23 is not fully open, the opening of the adjustment valve 23 is adjusted to become larger, and the pressure is used repeatedly The gauge 22 performs such detection and the controller 24 performs such adjustment, and sets the primary side pressure PA to an upper limit value P2 or less.

In the case where the primary pressure PA is higher than the upper limit P2, if the opening of the adjustment valve 23 is fully open, since the opening of the adjustment valve 23 cannot be adjusted larger, the controller 24 changes the delivery pump 18 by The number of rotations to adjust the delivery flow is lower than now. As the delivery flow rate becomes lower, the return flow rate and the flow rate of the paint 11 flowing toward the supply pump 21 become lower. Since the flow rate of the paint 11 flowing toward the supply pump 21 becomes low, the primary pressure PA And lower. The pressure gauge 22 detects a new primary-side pressure PA, and when the new detection result is within the set range PS, the number of revolutions of the delivery pump 18 and the supply pump 21 and the opening of the adjustment valve 23 are maintained. On the other hand, when the new detection result is still higher than the upper limit value P2, the controller 24 adjusts the opening degree of the adjustment valve 23 more like the above according to whether the opening degree of the adjustment valve 23 is fully open Larger or lower the sending flow. In this manner, by repeatedly detecting with the pressure gauge 22 and adjusting with the controller 24, the primary pressure PA is set to the upper limit value P2 or less.

When the primary pressure PA is lower than the lower limit P1, if the opening of the adjustment valve 23 is not closed (ie, open), the controller 24 adjusts the opening of the adjustment valve 23 to be smaller than it is now. The return flow rate becomes smaller because the opening degree of the adjustment valve 23 becomes smaller, and therefore the flow rate of the paint 11 flowing toward the supply pump 21 becomes larger, so the primary pressure PA becomes higher. The increased primary pressure PA is detected again by the pressure gauge 22. In the case where the new detection result is within the set range PS, the number of rotations of the delivery pump 18 and the supply pump 21 and the opening of the adjustment valve 23 are maintained The degree remains unchanged. On the other hand, when the new detection result is lower than the lower limit value P1 and the opening degree of the adjustment valve 23 is not closed, the controller 24 increases the primary side pressure by further reducing the opening degree of the adjustment valve 23 PA. As such, when the primary pressure PA is lower than the lower limit value P1 and the opening of the adjustment valve 23 is not closed, by adjusting the opening of the adjustment valve 23 to become smaller, the pressure gauge 22 is used repeatedly This detection is performed and the controller 24 performs such adjustment, and the primary pressure PA is set to the lower limit value P1 or more.

When the primary pressure PA is lower than the lower limit P1, if the opening degree of the adjustment valve 23 is closed, since the opening degree of the adjustment valve 23 cannot be adjusted Since it is smaller, the controller 24 adjusts the delivery flow rate to be higher than it is by changing the rotation number of the delivery pump 18. As the delivery flow rate becomes higher, the return flow rate and the flow rate of the paint 11 flowing toward the supply pump 21 become higher. As the flow rate of the paint 11 flowing toward the supply pump 21 becomes larger, the primary pressure PA becomes higher. The pressure gauge 22 detects a new primary-side pressure PA, and when the new detection result is within the set range PS, the number of revolutions of the delivery pump 18 and the supply pump 21 and the opening of the adjustment valve 23 are maintained. On the other hand, when the new detection result is still lower than the lower limit value P1, the controller 24 adjusts the opening of the adjustment valve 23 more like the above according to whether the opening of the adjustment valve 23 is closed Smaller or adjust the sending flow higher. In this way, by repeatedly detecting with the pressure gauge 22 and adjusting with the controller 24, the primary pressure PA is set to the lower limit value P1 or more.

As described above, in the case where the opening degree of the adjustment valve 23 is not fully open and when it is not closed, the return flow rate is adjusted by adjusting the opening degree of the adjustment valve 23, thereby controlling the primary side pressure PA within the aforementioned setting range PS. In addition, when the opening degree of the adjustment valve 23 is fully open and when it is closed, the primary pressure PA is controlled within the aforementioned setting range PS by adjusting the delivery flow rate. As such, since the primary side pressure PA is controlled (pressure control step), the paint 11 does not leak at the gears of the supply pump 21 or the like, and cavitation does not occur.

Furthermore, in the case where the adjustment valve 23 is fully opened, and therefore the delivery flow rate is to be adjusted, the delivery flow rate can also be adjusted lower until it becomes the range of the adjustable adjustment valve 23, which can be adjusted by adjustment The opening degree of the valve 23 is used to control the primary side pressure PA. Also, even if the opening of the adjustment valve 23 is closed, the flow rate to be adjusted In this case, the delivery flow rate can be similarly adjusted to be higher than the range of the adjustable adjustment valve 23 described above.

The paint 11 supplied by the supply pump 21 at a constant flow rate is continuously discharged from the casting die 28 toward the traveling belt 40. With this, the casting film 43 is continuously formed on the belt 40 (casting step). The casting film 43 is hardened by temperature adjustment or the like on the belt 40, and is peeled off from the belt 40 at the peeling position PP in a state containing a solvent (stripping step).

The film 12 formed by peeling the casting film 43 from the tape 40 is guided by the tenter 32, and is conveyed in a state where the side portion is held by the clip 46. The drying gas blown from the blower 47 accelerates the drying of the film 12 during transportation. At the downstream end of the tenter 32, the gripping of the film 12 by the clip 46 is released, and the film 12 is guided toward the roll dryer 33. While the film 12 is supported and transported by the rollers 48 of the roller dryer 33, the drying of the film 12 is further promoted. As such, the drying step for drying the film 12 is performed at both the tenter 32 and the roller dryer 33. The dried film 12 is wound into a roll shape by a winding machine 34. In this way, in the solution film-forming apparatus 10, the thin film 12 is manufactured from the coating material 11. Furthermore, a cutter (not shown) may be arranged further downstream than the tenter 32 to remove the gripping marks caused by the clip 46 on the film 12. Furthermore, in the present embodiment, when the film 12 is to contain a matting agent, it is preferably as follows: by supplying the dispersion liquid in which the matting agent has been dispersed in the dispersion medium between the supply pump 21 and the filter 25 The first piping L1 to add the matting agent to the paint 11.

<Second Embodiment>

The additive contained in the film 12 may be supplied to the film manufacturing apparatus 14 in addition to the paint supplied to the first pipe L1. The paint shown in Figure 3 The supply device 51 is used to manufacture a casting paint (hereinafter referred to as a casting paint) 56 by adding an additive liquid 53 to a reference paint 52 as a polymer solvent in which a polymer is dissolved in a solvent, and then to flow The extended paint 56 is supplied to the film manufacturing apparatus 14 in the same manner as the paint supply apparatus 13. In FIG. 3, the same devices and members as those of the solution film-forming apparatus 10 of FIG. 1 are given the same symbols as in FIG. 1 and the description is omitted.

In the case of manufacturing a plurality of kinds of films, the reference paint 52 is commonly used. In the present embodiment, TAC is used for the polymer system of the reference paint 52, and a mixture of methylene chloride, methanol, and butanol is used for the solvent system, but the polymer and the solvent are not limited thereto. The additive liquid 53 is a solution in which an additive is dissolved in a solvent. The additive in the present embodiment is a plasticizer, and may be a UV absorber, a retardation control agent, etc. instead of the plasticizer, or a UV absorber, a retardation control agent, etc. in addition to the plasticizer.

The paint supply device 51 is configured to include the third pipe L3 in the paint supply device 13 and is preferably provided with the static mixer 57 and the addition valve 58 as in the present embodiment. The third pipe L3 is a pipe for guiding the additive liquid 53. The third pipe L3 is connected to the first pipe L1 between the delivery pump 18 and the supply pump 21. When the pressure gauge 22 is provided in the first pipe L1 upstream of the supply pump 21 as in the present embodiment, the third pipe L3 is connected to the first pipe L1 between the delivery pump 18 and the pressure gauge 22. In FIG. 3, the connection position of the first pipe L1 and the third pipe L3 is given a symbol PJ.

The addition valve 58 is a valve for adjusting the flow rate of the additive liquid 53. The addition valve 58 is provided in the third pipe L3, and the additive added to the reference paint 52 flowing in the first pipe L1 is adjusted by adjusting the opening degree The flow rate of the liquid 53 (hereinafter referred to as the addition flow rate).

The concentration of the solid content of the reference paint 52 and the additive liquid 53 (hereinafter referred to as solid content concentration) may be mutually different, but it is preferably equal, and it is also set to be equal in this embodiment. The solid component constitutes the component of the film 12, that is, the component of the film 12. The solid component-based polymer of the reference paint 52 and the solid component-based plasticizer of the additive liquid 53 in this embodiment. Furthermore, the so-called "equal" is not limited to exactly the same, but as long as it is within 0.1%, preferably within 0.05%. In the case of manufacturing the thin film 12, the solid content concentration in the reference coating 52 is within a range of 15% or more and 25% or less, whereas the solid content concentration in a conventional additive liquid is within a range of 40% or more and 50% or less, Compared with the solid content concentration of the reference paint 52, it is set very high. On the other hand, in this embodiment, the solid content concentration of the additive liquid 53 is set to be equal to the solid content concentration of the reference paint 52, and is set to be much lower than the conventional additives. Thereby, even if the flow rate of the additive liquid 53 is changed as described later, for example, the solid content concentration in the casting dope 56 does not change, so it is possible to continue casting stably. In addition, the solid content concentration (unit: mass%) is calculated by the formula M1/(M1+M2 when the mass of the solid content is M1 (unit: g) and the mass of the solvent is M2 (unit: g) )×100.

The static mixer 57 is used to mix the reference paint 52 and the additive liquid 53 into a uniform state. The static mixer 57 is provided in the first pipe L1 between the connection position PJ and the supply pump 21. When the pressure gauge 22 is provided in the first pipe L1 upstream of the delivery pump 18 as in the present embodiment, the static mixer 57 may be provided in the first pipe L1 between the connection position PJ and the pressure gauge 22. As far as the static mixer 57 is concerned, the static State mixer, Sulzer mixer, etc. In this embodiment, the static mixer 57 is set to one. However, when the mixing state of the reference paint 52 and the additive liquid 53 is insufficient, the number of static mixers 57 may be increased.

The setting range PS of the primary-side pressure in this embodiment is set using the cast paint 56. The lower limit value P1 and the upper limit value P2 of the setting range PS are different depending on the cast paint 56 and therefore are obtained for the cast paint 56 used. Therefore, when a plurality of different kinds of casting paints 56 are to be switched and supplied to the film manufacturing apparatus 14, P1 and P2 are set for each casting paint 56 used. In addition, the composition of the paint 56 may change due to the start of manufacturing and adjusting the opening degree of at least one of the adjustment valve 23 and the addition valve 58. However, in such a case, the setting range PS set before the start of manufacturing may not be changed during the manufacturing process.

The function of the above structure will be described. The reference paint 52 prepared in advance and stored in the tank 17 is sent out from the tank 17 by the sending pump 18 at a fixed sending flow rate (feeding step). The reference paint 52 that is sent out is divided at the branch position PB into the paint that is led to the casting die 28 in the first pipe L1 and the paint that is led in the second pipe L2 (return step).

To the reference paint 52 guided from the branch position PB in the first pipe L1, the additive liquid 53 guided in the third pipe L3 (adding step) is added and mixed by the static mixer 57, A cast coating 56 in which the polymer and additives are mixed into a uniform state is obtained. The additive liquid 53 is added to the intermediate reference paint 52 of the first pipe L1 in this way. Therefore, in the case of switching the type of the film 12, it is possible to add The agent liquid 53 is switched to another type, and the flow rate of the additive liquid 53 is adjusted by the addition valve 58. According to this technique, there is no need to prepare and store paint according to the type of the film 12 to be manufactured. In addition, when switching the type of the film 12 to be manufactured, it is not necessary to replace the entire piping of the paint supply device with new paint, and replace the paint in the third pipe L3 with the first pipe L1 downstream of the connection position PJ. Paint is enough. The casting paint 56 is supplied to the casting die 28 via the filter 25 by the supply pump 21. On the other hand, the reference paint 52 guided in the second pipe L2 is sent back to the tank 17.

When the primary side pressure PA detected by the pressure gauge 22 is within the set range PS, the number of revolutions of the delivery pump 18 and the supply pump 21 and the opening degree of the adjustment valve 23 are maintained. When the primary pressure PA is not within the set range PS, the primary pressure PA is controlled within the set range PS by the controller 24 in the same manner as in the first embodiment. That is, in the case where the opening degree of the adjustment valve 23 is not fully open and when it is not closed, the return flow rate of the reference paint 52 is adjusted by adjusting the opening degree of the adjustment valve 23, thereby controlling the primary side pressure PA to the aforementioned Within the setting range PS. In addition, when the opening degree of the adjustment valve 23 is fully open and when it is closed, the primary side pressure PA is controlled within the aforementioned setting range PS by adjusting the delivery flow rate of the reference paint 52. As such, since the primary-side pressure PA of the supply pump 21 is controlled (pressure control step), the cast paint 56 does not leak at the gears of the supply pump 21 or the like, and cavitation does not occur.

The mass ratio of the additive to the polymer is preset according to each manufactured film 12. When the mass of the polymer in the reference coating 52 does not reach the desired range relative to the mass of the additive in the additive liquid 53, by adjusting the return flow rate or adjusting the flow rate, the addition valve The opening of 58 is adjusted to be smaller than it is now. For example, by reducing the opening degree of the addition valve 58, the addition flow rate is adjusted to fall within a range of not less than 0.01 times but not more than 1.0 times. By adjusting the flow rate ratio of the additive liquid 53 to the reference paint 52, the polymer mass relative to the additive mass can fall within a desired range. When the flow rate of the additive liquid 53 is changed in this way, the flow rate of the cast paint 56 also changes. However, in this case, the primary pressure PA is also detected and controlled within the set range PS, so the cast paint 56 does not leak at the gears of the supply pump 21, etc. Erosion phenomenon.

In addition, the mass ratio of the additive to the polymer is preset for each film 12 manufactured. Therefore, in the case of using the additive liquid 53 having a solid content concentration equal to that of the reference coating 52 as in the present embodiment, it is compared with the conventional one. When the solid content concentration is higher than the additive liquid of the reference paint 52, the addition flow rate of the additive liquid 53 relative to the reference paint 52 is increased. For example, in the case where the additive liquid 53 has a solid content concentration of 24%, the flow rate of the additive liquid 53 added to the reference coating 52 is adjusted to the case where the additive liquid with a solid content concentration of 50% is used. More than 2 times. Even if the addition flow rate is so large, the primary pressure PA is controlled so as not to exceed the set range PS, so the cast paint 56 does not leak at the gears of the supply pump 21 or the like.

In addition, in the case of switching to manufacture a plurality of kinds of films 12, changing the kind of additive liquid 53 or changing the addition flow rate relative to the reference paint 52, etc., switching the plurality of different kinds of casting paints 56 and feeding the film 21 toward the film The manufacturing device 14 supplies. However, according to the above configuration, the setting range PS is obtained for each of the plural cast paints 56 to be used, and Since the primary side pressure PA is controlled within the set range PS, the cast paint 56 does not leak at the gears of the supply pump 21 or the like, and cavitation does not occur.

By the supply pump 21, the casting dope 56 is supplied to the casting die 28 of the film manufacturing apparatus 14 at a constant flow rate through the filter 25 (supply step). The supplied casting paint 11 is directed toward the traveling belt 40, is continuously discharged from the casting die 28, and the film 12 is produced in the same manner as in the first embodiment. Furthermore, in the present embodiment, when the matting agent is contained in the film 12, it is preferably as follows: As described above, by supplying the dispersion liquid in which the matting agent has been dispersed in the dispersion medium to the supply pump 21 and The first pipe L1 between the filters 25 adds the matting agent to the casting dope 56.

<Third Embodiment>

The above-mentioned embodiment is an example for manufacturing a single-layer structured film 12 (that is, so-called single-layer casting). The present invention is in the case where a plurality of coating materials are co-cast for manufacturing a multi-layer structure film, or the The case of layer casting and co-casting is also very effective. In the case of switching between single-layer casting and co-casting, the type of paint supplied will also be switched. The paint supply device 71 shown in FIG. 4 switches the supply of paint in order to switch between manufacturing the single-layer cast single-layer structure film 12 and the co-cast multi-layer structure film. In this example, the common casting system is set to manufacture a thin film with a three-layer structure, but the number of thin film layers to be manufactured is not limited to 3, and may be 2 or 4 or more, for example. In FIG. 4, the same devices and components as those shown in FIGS. 1 and 3 are given the same symbols as in FIGS. 1 and 3, and the description is omitted.

In the case of manufacturing the single-layer structure film 12, the paint supply device 71 supplies the coating material to the casting die 28; when manufacturing the three-layer structure film ( In the case of (not shown), the paint is supplied to the casting die 72. The casting die 72 is a system in which three independently supplied paints are merged inside and continuously discharged from one discharge port 72a in a merged state. The first branch pipe LB1 branched from the first pipe L1 connected to the casting die 28 is connected to the casting die 72, and a switching valve 73 is provided at a branch position where the first branch pipe LB1 branches. The film manufacturing apparatus (not shown) provided with the casting die 72 is the same as the film manufacturing apparatus 14 except for the casting die 72.

The paint supply device 71 in this example switches the paint to the film manufacturing device 14 and the film manufacturing device including the casting die 72, but it is not limited thereto. For example, when the film manufacturing apparatus 14 switches the casting mold 28 and the casting mold 72 to switch between single-layer casting and multi-layer casting, the paint supply device 71 can also be used. Furthermore, instead of using a feeder that merges three types of paint supplied independently, and a casting die that continuously discharges the paint guided from the layerer in a stacked state from the discharge port, instead Casting die 72.

In this embodiment, the position where the second pipe L2 branches from the first pipe L1 is referred to as the first branch position and is given the symbol PB1; the supply pump provided in the first pipe L1 is called the first supply pump and is given Symbol 21a. This first supply pump 21a is set to the same structure as the supply pump 21 of the first and second embodiments. The filter system downstream of the first supply pump 21a of the first pipe L1 is set to have the same structure as the filter 25 of the first and second embodiments, and reference numeral 25a is given in FIG. 4.

The paint supply device 71 is used to manufacture the first cast paint 75 and the second cast paint 76 from the reference paint 52 and supply these to the casting die 28 and the casting die 72. As far as the first cast coating 75 is concerned, there are The paint obtained by adding the additive liquid 77 to the reference paint 52 and the paint obtained by adding the first additive liquid 77 and the second additive liquid 78 to the reference paint 52. The first cast coating 75 obtained by adding the first additive liquid 77 to the reference coating 52 is used for single-layer casting to manufacture the single-layer structured film 12 and is supplied to the casting die 28. The first casting liquid 75 obtained by adding the first additive liquid 77 and the second additive liquid 78 to the reference coating 52 is used for co-casting to produce a 3-layer structure film (not shown), and is supplied to the casting die 72. The first additive liquid 77 and the second additive liquid 78 are added to the first casting paint 75 obtained by the reference paint 52, and specifically, an inner layer in the center in the thickness direction among the three layers constituting the film is formed.

The second cast coating 76 is a mixture of the reference coating 52 and the first additive liquid 77 and the second additive liquid 78, specifically, a liquid obtained by adding the first additive liquid 77 to the reference coating 52 and adding it to the reference The paint 52 is obtained by adding the first additive liquid 77 and the second additive liquid 78 to the first cast paint 75. The second casting paint 76 is used for co-casting to form a layer (hereinafter referred to as an outer layer) which is arranged on each surface of the inner layer and exposed to the outside among the three layers constituting the film.

In the present embodiment, the first additive liquid 77 is a solution in which a plasticizer is dissolved in a solvent, and the second additive liquid 78 is a solution in which a plasticizer and a UV absorber are dissolved. This second additive liquid 78 is obtained by, for example, mixing a plasticizer liquid containing a plasticizer and a UV absorber liquid containing a UV absorber. However, the first additive liquid 77 and the second additive liquid 78 are not limited thereto, and may be a delay control agent to replace the plasticizer and UV absorber, or there may be a delay control agent in addition to the plasticizer and UV absorber. In addition, the plasticizers of the first additive liquid 77 and the second additive liquid 78 are in this embodiment. It is the same plasticizer, but it can also be a different plasticizer.

The solid concentration of the first additive liquid 77 and the second additive liquid 78 may be different from that of the reference paint 52, but it is preferably equal to the solid content concentration, which is also set to be equal in this embodiment. The solid component polymer of the reference coating 52 in this embodiment, the solid component plasticizer of the first additive liquid 77, and the solid component plasticizer and UV absorber of the second additive liquid 78. Furthermore, the meaning of "equal" is as described above. In the case of manufacturing a three-layer structure film, the solid content concentration in the reference coating 52 is within a range of 15% or more and 25% or less. In contrast, the solid content concentration in the first additive liquid and the second additive liquid is 45 Within the range of% or more and 50% or less, the solid content concentration of the reference paint 52 is set to be very high. On the other hand, in this embodiment, the solid content concentration of the first additive liquid 77 and the second additive liquid 78 is set to be equal to the solid content concentration of the reference paint 52, which is much lower than the conventional first additive liquid and the second Additive liquid. Thereby, even if the flow rate of the first additive liquid 77 and the flow rate of the second additive liquid 78 are changed in the same manner as in the second embodiment, the solid content concentration in the first cast coating 75 and the second cast coating 76 does not change. Therefore, casting can be continued stably.

The paint supply device 71 is set to add one static mixer, two supply pumps, two filters, fourth piping L4, first branch piping LB1 to fourth branch piping to the paint supply device 51 (see FIG. 3). The composition of LB4. Two static mixers are arranged in-line in the first piping L1. One of the upstream mixers is the first static mixer 83, and the other downstream mixer is the second static mixer.器84.

The third piping L3 and the fourth piping L4 are respectively matched with the first piping Tube L1 is connected. The third pipe L3 is a pipe for guiding the first additive liquid 77 in the first pipe L1. The position where the third pipe L3 is connected to the first pipe L1 is defined as the first connection position PJ1.

The fourth pipe L4 is a pipe for guiding the second additive liquid 78 in the first pipe L1. The position where the fourth pipe L4 is connected to the first pipe L1 is set as the second connection position PJ2.

The third pipe L3 is provided with an addition valve 88, and the fourth pipe L4 is provided with an addition valve 87. When the first additive liquid 77 is to be added to the reference paint 52, the first additive liquid 77 merges with the reference paint 52 at the first connection position PJ1 of the first pipe L1. In addition, when the second additive liquid 78 is to be added to the reference paint 52, the second additive liquid 78 merges with the reference paint 52 at the second connection position PJ2 of the first pipe L1. The first static mixer 83 is arranged between the first connection position PJ1 and the second connection position PJ2, the second static mixer 84 is arranged between the second connection position PJ2 and the pressure gauge 22, and the combined The reference paint 52, the first additive liquid 77, and the second additive liquid 78 are mixed into a uniform state to become the first cast paint 75.

The second branch piping LB2 and the third branch piping LB3 are used to guide the first casting paint 75, make the second casting paint 76, and then guide the second casting paint 76 to the casting die 72. The second branch piping LB2 and the third branch piping LB3 branch off from the first piping L1 downstream of the pressure gauge 22 and are connected to the casting die 72. The second branch piping LB2 includes a valve 91, a second supply pump 21b, and a filter 25b. The third branch piping LB3 is also configured like the second branch piping LB2, and includes a valve 92, a third supply pump 21c, and a filter 25c. Valves 91 and 92 are manufactured in a single-layer structure In the case of the thin film 12, it is closed, and in the case of manufacturing a three-layer structure thin film, it is opened.

The second supply pump 21b and the third supply pump 21c are used to supply the second casting paint 76 to the casting die 72 at a fixed flow rate through the filters 25b and 25c, respectively. The second supply pump 21b and the third supply pump 21c have the same configuration as the first supply pump 21a, that is, the same configuration as the supply pump 21 of the first and second embodiments.

The fourth branch piping LB4 is used to guide the reference paint 52 to which the first additive liquid 77 is added at the first connection position PJ1 to the second branch piping LB2 and the third branch piping LB3. The fourth branch piping LB4 is branched from the first piping L1 between the first static mixer 83 and the second connection position PJ2. The branch position where the fourth branch pipe LB4 branches from the first pipe L1 is referred to as a second branch position PB2. The fourth branch piping LB4 is provided with a valve 93, and branches into two parts downstream of the valve 93. One part of the branch is connected between the valve 91 of the second branch piping LB2 and the second supply pump 21b, and the other part of the branch is connected between the valve 92 of the third branch piping LB3 and the third supply pump 21c.

In the present embodiment, the pressure gauge 22 is used to detect all primary pressures PA of the first to third supply pumps 21a to 21c. Furthermore, a pressure gauge (not shown) for detecting the primary pressures of the second supply pump 21b and the third supply pump 21c may be further provided in the second branch piping LB2 and the third branch piping LB3. In this case, the pressure gauges may be installed between the connection position where the second branch piping LB2 and the fourth branch piping LB4 are connected to the second supply pump 21b, and the third branch piping LB3 and the fourth branch piping LB4 are connected Connection position and third supply pump Between 21c. In addition to the pressure gauges 22 and these pressure gauges, the controller 24 adjusts the opening of the adjustment valve 23 based on these three detection results, more reliably at the gears of the first supply pump 21a to the third supply pump 21c, etc. There will be no leakage of the first cast paint 75 and the second cast paint 76, and no cavitation will occur.

The setting range PS of the primary pressure PA of the first supply pump 21a to the third supply pump 21c of this embodiment is set using the first cast paint 75 and the second cast paint 76. In addition, by starting manufacturing and adjusting the opening degree of at least one of the adjustment valve 23 and the addition valves 87 and 88, the composition of the first casting paint 75 and the second casting paint 76 may change. However, in this case, the setting range PS set before starting the manufacturing may not be changed during the manufacturing.

The function of the above structure will be described. The reference paint 52 prepared in advance and stored in the tank 17 is sent out from the tank 17 by the sending pump 18 at a fixed sending flow rate (feeding step). The reference paint 52 that is sent out is divided at the first branch position PB1 into the reference paint that is led to the casting die 28 or the casting die 72 in the first pipe L1, and is guided (returned) in the second pipe L2 Step) benchmark paint.

When manufacturing the thin film 12 of the single-layer structure, the addition valve 88 is opened, and the first additive liquid 77 is used. In addition, in the case of manufacturing the single-layer structure thin film 12, the addition valve 87 is closed. Further, the valve of the first pipe L1 of the valve 73 is opened, the valve on the side of the first branch pipe LB1 is closed, and the valves 91 to 93 are closed. By setting the addition valves 87 and 88 to the above-described open/closed state, the first additive liquid 77 is guided to the first pipe L1, but the second additive liquid 78 is not guided. From the first branch position PB1 The reference paint 52 guided in the first pipe L1 is added with the first additive liquid 77 guided in the third pipe L3 (adding step).

The reference paint 52 and the first additive liquid 77 that meet at the first connection position PJ1 are mixed by the first static mixer 83 and the second static mixer 84, and the polymer and the plasticizer are mixed into a uniform state的第一 fluidizing coating 75. The first casting paint 75 is supplied to the casting die 28 via the filter 25a by the first supply pump 21a. On the other hand, the reference paint 52 guided in the second pipe L2 is sent back to the tank 17.

When the primary pressure PA of the first supply pump 21a is detected by the pressure gauge 22, and the primary pressure PA is within the set range PS, the number of revolutions of the delivery pump 18 and the first supply pump 21a and the opening of the adjustment valve 23 are maintained The degree remains unchanged. When the primary pressure PA of the first supply pump 21a is not within the set range PS, the primary pressure PA of the first supply pump 21a is controlled by the controller 24 in the same manner as in the first and second embodiments. Within the setting range PS. That is, when the opening degree of the adjustment valve 23 is not fully open, the return flow rate of the reference paint 52 is adjusted by adjusting the opening degree of the adjustment valve 23, whereby the first supply pump 21a The side pressure PA is controlled within the aforementioned setting range PS. In addition, when the opening degree of the adjustment valve 23 is fully open and when it is closed, the primary side pressure PA of the first supply pump 21a is controlled within the aforementioned setting range PS by adjusting the delivery flow rate of the reference paint 52 . As such, since the primary-side pressure PA of the first supply pump 21a is controlled (pressure control step), the cast paint 75 does not leak at the gears or the like of the first supply pump 21a, nor does it Cavitation occurred.

When manufacturing the single-layer film 12, the first casting paint 75 is supplied to the casting die 28 at a fixed flow rate through the filter 25 a by the first supply pump 21 a (supply step). The first casting paint 75 supplied is directed toward the traveling belt 40, is continuously discharged from the casting die 28, and the film 12 is manufactured in the same manner as the first embodiment and the second embodiment.

When manufacturing a multilayer structure film, the addition valves 87 and 88 are opened, and the first additive liquid 77 and the second additive liquid 78 are used. Further, the valve on the upstream side of the first pipe L1 and the valve on the first branch pipe LB1 side of the valve 73 are opened, the valves on the downstream side of the first pipe L1 are closed, and the valves 91 to 93 are opened.

By setting the addition valves 87 and 88 to the above-mentioned open and closed state, the first additive liquid 77 and the second additive liquid 78 are led to the first pipe L1, respectively. The reference paint 52 guided in the first pipe L1 from the first branch position PB1 is first charged with the first additive liquid 77 guided in the third pipe L3 (first addition step). The reference paint 52 merged at the first connection position PJ1 and the first additive liquid 77 are mixed by the first static mixer 83. This mixed liquid system branches at the second branch position PB2 into a mixed liquid guided in the first pipe L1 and a mixed liquid guided in the fourth branch pipe LB4.

The above mixed liquid guided in the first pipe L1 is added with the second additive liquid 78 guided in the fourth pipe L4 (second addition step). The mixed liquid and the second additive liquid 78 merged at the second connection position PJ2 are mixed by the second static mixer 84 to obtain a first casting in which the polymer and the plasticizer and the UV absorber are mixed into a uniform state Paint 75. The first cast paint 75 is guided to the first pipe L1 , The second branch piping LB2, the third branch piping LB3. Each of the first casting paints 75 flowing through the second branch piping LB2 and the third branch piping LB3 is added to the above-mentioned mixed liquid guided in the fourth branch piping LB4, respectively, to obtain a uniformly mixed second casting paint 76. . The first casting paint 75 flowing through the first piping L1 and the second casting paint 76 flowing through the second branch piping LB2 and the third branch piping LB3 are supplied by the first supply pump 21a to the third supply. The pump 21c is supplied to the casting die 72 via the filters 25a to 25c. On the other hand, the reference paint 52 guided in the second pipe L2 is returned to the tank 17 (return step).

In the case where the single-layer structure film 12 is manufactured as described above and the multi-layer structure film is manufactured, the opening and closing of the addition valve 87, the addition valve 88, the valve 73, and the valve 91 to the valve 93 are switched. In this way, the type of additive liquid used and the liquid supply line are switched to switch the type of film manufactured.

According to this technique, there is no need to separately prepare and store paints according to the type of film produced. In addition, when switching the type of film to be manufactured, it is not necessary to replace the entire piping of the paint supply device with new paint, and replace part of the third piping L3 with the paint in the first piping L1 downstream of the first connection position PJ1 That's it.

When the primary pressure PA of the first supply pump 21 a to the third supply pump 21 c detected by the pressure gauge 22 is within the set range PS, the delivery pump 18 and the first supply pump 21 a to the third supply pump 21 c are maintained. The number of rotations and the opening of the adjustment valve 23 remain unchanged. When the primary pressure PA of the first supply pump 21a to the third supply pump 21c is not within the set range PS, the first supply pump 21a is controlled by the controller 24 in the same manner as the first embodiment and the second embodiment. ~ Primary pressure PA control of the third supply pump 21c Within the setting range PS. That is, when the opening degree of the adjustment valve 23 is not fully open, the return flow rate of the reference paint 52 is adjusted by adjusting the opening degree of the adjustment valve 23, whereby the first supply pump 21a to the third The primary pressure PA of the supply pump 21c is controlled within the aforementioned set range PS. In addition, when the opening degree of the adjustment valve 23 is fully open and when it is closed, the primary pressure PA of the first supply pump 21a to the third supply pump 21c is controlled by adjusting the delivery flow rate of the reference paint 52 Within the aforementioned setting range PS. As such, since the primary-side pressure PA of the first supply pump 21a to the third supply pump 21c is controlled (pressure control step), the first supply pump 21a to the gear of the third supply pump 21c, etc. do not occur In the case of the leakage of the first cast paint 75 and the second cast paint 76, in addition, cavitation will not occur.

For example, a case where a gear pump (manufactured by Shimadzu Corporation) is used as the supply pump 21 and a reference coating 52 and a second additive solution 78 of the following prescription are used to manufacture a three-layer structure film will be described in detail. By setting PAL×1.1 to P1 and PAH×0.9 to P2, the setting range PA in this embodiment is set to a range of 0.1 MPa or more and 0.5 MPa or less. In addition, with respect to the flow rate of the reference paint 52, the added flow rate of the second connection position PJ2 of the second additive liquid 78 is set to 10%. The occurrence of cavitation erosion is evaluated by setting them downstream of the filter 25a of the first pipe L1, downstream of the filter 25b of the second branch pipe LB2, and downstream of the filter 25c of the third branch pipe LB3 Observation windows, visually observe from these observation windows to confirm the presence or absence of bubbles in the first casting paint 75 and the second casting paint 76. In addition, the leakage of the first cast paint 75 and the second cast paint 76 in the gear part was also confirmed by visual observation.

The prescription of the reference paint 52 is as follows. The solvent system is a mixture of three components, the first component is dichloromethane, the second component is methanol, and the third component is butanol.

The prescription of the first additive solution 77 is as follows.

The prescription of the second additive liquid 78 is as follows.

The plasticizer is a condensate of ethylene glycol and adipic acid (number average molecular weight 1000, hydroxyl value 112 mgKOH/g), and the molar ratio of ethylene glycol/adipic acid of this condensate is 1/1. The above-mentioned UV absorber is Tinuvin 928 manufactured by BASF JAPAN Corporation.

The controller 24 controls the first supply pump 21a to the third When the primary pressure PA of the supply pump 21c is made to be (PAL×1.1) or more (PAH×0.9) or less, the gears of the first supply pump 21a to the third supply pump 21c will not be cast. In the case of paint 56 leakage, cavitation will not occur. On the other hand, when the primary pressure PA of the first supply pump 21 a to the third supply pump 21 c does not reach (PAL×1.1) without being controlled by the controller 24, the first supply pump 21 a to the third supply The cavitation phenomenon occurs in the pump 21c. In addition, without control by the controller 24, when the primary pressure PA of the first supply pump 21a to the third supply pump 21c is greater than (PAH×0.9), the first cast paint 75 and the second cast paint 76 are The gears of the first to third supply pumps 21a to 21c leak.

As in the second embodiment, by adjusting the return flow rate or the delivery flow rate, when the mass of the polymer does not reach the desired range with respect to the mass of the first additive or the second additive, the valve 87 for addition The opening of 88 is adjusted smaller than it is now. For example, in the present embodiment, by reducing the opening of the valves 87 and 88 for addition, the flow rates of the first additive liquid 77 and the second additive liquid 78 are reduced to more than 0.05 times and less than 1.0 Within range. By this, the flow rate ratio of the first additive liquid 77 and the reference paint 52, the flow rate ratio of the second additive liquid 78, the mixed liquid of the second additive liquid 78 and the reference paint 52, with respect to the mass of the plasticizer and the UV absorber, The quality of the polymer falls within the desired range. In this way, when the flow rates 1 of the first additive liquid 77 and the second additive liquid 78 are changed, the first cast paint 75 also changes. However, this example also detects the primary pressure PA of the first supply pump 21a to the third supply pump 21c and controls it within the set range PS in the same manner as the first embodiment and the second embodiment. Therefore, the first supply pump 21a~third supply No leakage of the first cast paint 75 and the second cast paint 76 occurs in the gears of the pump 21c or the like, and cavitation does not occur.

In addition, as mentioned above, the mass ratio of additives to polymers such as plasticizers and UV additives is preset for each manufactured film. In this embodiment, since the first additive liquid 77 and the second additive liquid 78 having a solid content concentration equal to that of the reference paint 52 are used, compared with the case where an additive liquid having a solid content concentration higher than the reference paint 52 is used in the past, the The addition flow rates of the first additive liquid 77 and the second additive liquid 78 with respect to the reference paint 52 are increased. Even when the addition flow rate is as large as this, the primary pressure PA of the first supply pump 21a to the third supply pump 21c is controlled so as not to exceed the set range PS, so the first supply pump 21a to the second There will be no leakage of the first cast paint 75 and the second paint 76 at the gears of the third supply pump 21c or the like.

In addition, when switching between the production of the single-layer structure film 12 and the multi-layer structure film, the second additive liquid 78, or the first additive liquid 77 and the second additive liquid 78 are often added to the reference coating 52 in a flow rate that is often mutual. different. Therefore, the flow rate of the first cast paint 75 to the first supply pump 21a and the flow rate of the second cast paint 76 to the second supply pump 21b and the third supply pump 21c are changed by switching the manufactured films. However, according to the above configuration, the set range PS is obtained for each of the first cast paint 75 and the second cast paint 76, and the primary pressure PA of the first supply pump 21a to the third supply pump 21c is controlled within the set range. In the PS, the first cast paint 75 and the second cast paint 76 do not leak at the gears of the first to third supply pumps 21a to 21c, and cavitation does not occur.

In the case of manufacturing a multi-layer structure film, the first casting pump 75a is supplied to the casting die 72 at a fixed flow rate through a filter 25a, and the second feeding pump 21b and the third feeding pump 21c are used to pass through. The filters 25b and 25c supply the second casting paint 76 to the casting die 72 at a fixed flow rate (supply step). The supplied first casting paint 75 and second casting paint 76 are directed toward the traveling belt 40 and are continuously discharged from the casting die 72. Thereby, a three-layer structure film in which the inner layer formed by the first casting paint 75 is sandwiched by the outer layer formed by the second casting paint 76 is manufactured.

In the present embodiment, when the single-layer structure film 12 contains a matting agent, by supplying the dispersion liquid in which the matting agent has been dispersed in the dispersion medium between the first supply pump 21a and the filter 25a In the first piping L1, it is preferable to add the matting agent to the first casting paint 75. In addition, when the matting agent is contained in the film of the multi-layer structure, the second branch between the second supply pump 21b and the filter 25b is supplied by separately supplying the dispersion liquid in which the matting agent has been dispersed in the dispersion medium At least one of the piping LB2 and the third branch piping LB3 between the third supply pump 21c and the filter 25c is preferably used to add the matting agent to the second casting paint 76.

The single-layer structure film 12 obtained in the first to third embodiments and the three-layer structure film obtained in the third embodiment are used as optical films when a transparent polymer is used. Examples of optical films include protective films for polarizing plates and retardation films.

As for the transparent polymer, there are acetylated cellulose and cyclic polyolefin, and these can be used in the above-mentioned embodiments. The following details Brightened cellulose.

<Acetate Cellulose>

Acetyl cellulose is the ratio of esterifying the hydroxyl group of cellulose with carboxylic acid (that is, the degree of substitution of the acetyl group) (hereinafter referred to as the degree of substitution of the acetyl group) to satisfy all of the following formulas (1) to (3) Conditions are particularly good. In addition, in (1) to (3), both A and B are the degree of substitution of the acetyl group, the acetyl group of A is an acetyl group, and the acetyl group of B is an acetyl group having 3 to 22 carbon atoms.

2.4≦A+B≦3.0‧‧‧‧(1)

0≦A≦3.0‧‧‧‧(2)

0≦B≦2.9‧‧‧(3)

The glucose unit that constitutes cellulose and has β-1,4 linkages has free hydroxyl groups at the 2, 3, and 6 positions. The acylated cellulose is a polymer in which part or all of the hydroxyl groups of such cellulose are esterified, and the hydrogen of the hydroxy group is replaced with an acetyl group having 2 or more carbon atoms. Furthermore, when one hydroxyl group in the glucose unit is 100% esterified, the degree of substitution is 1, so in the case of cellulose acylate, when the hydroxyl group at the 2, 3, and 6 positions are 100% esterified, respectively When changing, the degree of substitution is 3.

Here, in glucose units, the degree of substitution of the acyl group at the 2-position is DS2, the degree of substitution of the acyl group at the 3-position is DS3, and the degree of substitution of the acyl group at the sixth position is DS6, and "DS2+DS3+DS6 The degree of substitution of the peracyl group obtained is preferably from 2.00 to 3.00; preferably from 2.22 to 2.90; more preferably from 2.40 to 2.88. In addition, "DS6/(DS2+DS3+DS6)" is preferably at least 0.32; preferably at least 0.322; more preferably at 0.324~0.340.

The acyl group may be only one kind, or two or more kinds. When there are two or more types of acetyl groups, one of them is preferably acetyl group. In 2nd, 3rd and When the hydrogen of the 6-position hydroxyl group is substituted with an acetyl group, the sum of the substitution degrees is set to DSA, and the substitution degree is substituted when the 2-, 3-, and 6 positions are substituted with an acetyl group other than the acetyl group. The sum of is set to DSB. At this time, the value of "DSA+DSB" is preferably 2.2~2.86; the value of 2.40~2.80 is particularly good. DSB is better than 1.50; better than 1.7. In addition, DSB is preferably substituted by more than 28% of the 6-position hydroxyl group; more than 30% is more preferred; more than 31% is more preferred; and more than 32% is substituted by the 6-position hydroxyl group. In addition, the value of "DSA+DSB" at the 6-position of the cellulose acylate is preferably 0.75 or more; 0.80 or more is preferable; and 0.85 or more is particularly preferable. By using such acetylated cellulose, a better solubility can be obtained to make a polymer solution for solution film formation.

The acyl group having a carbon number of 2 or more may be an aliphatic group or an aryl group, and is not particularly limited. For example, there are alkylcarbonyl esters, alkenylcarbonyl esters, or aromatic carbonyl esters of aromatic cellulose, aromatic Group carbonyl esters, etc., these may also have a substituted group. Examples include acryl, butyl, pentyl, hexyl, octyl, decyl, twelve, thirteen, tetradecyl, hexadecyl, octyl, and isobutyl. , Third butyl acetyl group, cyclohexane carbonyl group, oleoyl group, benzoyl group, naphthyl carbonyl group, cinnamyl acetyl group. Among these, propionyl, butyryl, dodecyl, octadecyl, tertiary butyl, oleyl, benzyl, naphthylcarbonyl, cinnamyl, etc. are preferred; propionyl, Ding Yanji is particularly good.

In the case of using cellulose acylate as a polymer, each solvent of the paint 11, the casting paint 56, the first casting paint 75, and the second casting paint 76 can be used when the cellulose acylate film is produced by the solution film-forming method. A well-known solvent for paints. For example, dichloromethane, various alcohols, various ketones, etc. It is also possible to use a mixture obtained by mixing plural kinds selected from these as a solvent. In the case of using a mixture as a solvent, the mixture may also be a mixture obtained by adding a weak solvent to a good solvent of acetylated cellulose. When using the cellulose acylate as a polymer, each solvent of the additive liquid 53, the first additive liquid 77, and the second additive liquid 78 preferably has a component common to the solvent of the cellulose acylate.

The above embodiments are examples in which a casting die is used as the discharge unit, but the discharge unit is not limited to this.

10‧‧‧Solution film making equipment

11‧‧‧Paint

12‧‧‧ film

13‧‧‧Paint supply device

14‧‧‧ Thin film manufacturing equipment

17‧‧‧Slot

18‧‧‧send pump

21‧‧‧Supply pump

22‧‧‧pressure gauge

23‧‧‧Adjusting valve

24‧‧‧Controller

25‧‧‧filter

28‧‧‧Casting mode

28a‧‧‧spit out

31‧‧‧ Casting unit

32‧‧‧tenter

33‧‧‧Roll dryer

34‧‧‧coiler

40‧‧‧Support belt

41‧‧‧Roll

42‧‧‧ Stripping roller

43‧‧‧Casting film

46‧‧‧ folder

47‧‧‧Blower

48‧‧‧roll

L1~L2‧‧‧First to second piping

PB‧‧‧Branch position

PC‧‧‧Casting position

PP‧‧‧Stripping position

Claims (8)

A solution film forming method that guides a polymer solution stored in a storage part and a polymer dissolved in a solvent to the casting die by using a first pipe extending from the storage part to a casting die, Continuously discharging from the casting die and drying it to produce a film, characterized by including: a sending step, the polymer solution stored in the storage part is sent out by a sending pump; a supply step is The polymer solution sent from the storage part is supplied to the casting die at a fixed flow rate by a supply pump provided downstream of the delivery pump, and the supply pump is a gear pump; the adding step dissolves the film in the solvent The additive solution containing the additive is added to the polymer solution in the first pipe through a third pipe connected between the delivery pump and the supply pump of the first pipe; and a pressure detection step to detect The pressure on the primary side of the supply pump; the second pipe branched from the connection position where the delivery pump of the first pipe is connected to the third pipe and connected to the storage part A part of the polymer solution is sent back to the storage part; by adjusting the opening of the adjustment valve provided in the second pipe according to the detection result of the pressure detection step, the pressure on the primary side is controlled within a preset fixed range Inside. The solution film production method according to claim 1, wherein the flow rate of the additive liquid is adjusted by an addition valve provided in the third pipe. The solution film-forming method according to claim 1 or 2, wherein the aforementioned additive liquid and The solid content concentrations of the aforementioned polymer solutions are equal to each other. The solution film production method according to claim 1 or 2, wherein the type of the aforementioned additive liquid is switched when the type of the aforementioned thin film to be manufactured is switched. A solution film forming method that guides a polymer solution stored in a storage part and a polymer dissolved in a solvent to the casting die by using a first pipe extending from the storage part to a casting die, It is continuously discharged from the casting die and dried to produce a film, which is characterized by comprising: a sending step, the polymer solution stored in the storage part is sent out by a sending pump; a supply step is The polymer solution sent from the storage part is supplied to the casting die at a fixed flow rate by a supply pump provided downstream of the delivery pump, and the supply pump is a gear pump; the adding step dissolves the film in the solvent The additive solution containing the additive is added to the polymer solution in the first pipe through the third pipe connected between the delivery pump and the supply pump of the first pipe; the pressure detection step detects the Pressure on the primary side of the supply pump; casting step, the aforementioned polymer solution is continuously discharged from the casting die onto the casting support to form a casting film; stripping step, stripping from the casting support The cast film; and a drying step to dry the film formed by the peeling step; by branching from the connection position where the delivery pump of the first pipe is connected to the third pipe and toward Connection of the aforementioned storage section Of the second piping, returning part of the polymer solution from the delivery pump to the reservoir; by adjusting the opening of the adjustment valve provided in the second piping based on the detection result of the pressure detection step, the The pressure on the primary side is controlled within a preset fixed range. The solution film production method according to claim 5, wherein the flow rate of the additive liquid is adjusted by the addition valve provided in the third pipe. The solution film-forming method according to claim 5 or 6, wherein the solid content concentrations of the aforementioned additive liquid and the aforementioned polymer solution are equal to each other. The solution film-forming method according to claim 5 or 6, wherein the type of the aforementioned additive liquid is switched when the type of the aforementioned thin film to be manufactured is switched.

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