JP2017145272A - Apparatus for producing polymer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing a polymer film which can promptly remove a floating foreign substance in a liquid treatment tank.SOLUTION: The apparatus for producing a polymer film includes a liquid treatment unit for performing liquid treatment by immersing a polymer film in a treatment liquid while continuously transporting the polymer film, and is configured such that the liquid treatment unit includes an immersion tank in which the treatment liquid in which the polymer film is immersed is stored, a circulation tank adjacent to the immersion tank, and a treatment liquid supply unit which supplies a new treatment liquid, the treatment liquid is first supplied from the treatment liquid supply unit to the circulation tank and further supplied from the circulation tank to the immersion tank, and the treatment liquid overflowing and flowing out from the immersion tank flows into the circulation tank.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polymer film manufacturing apparatus having a liquid processing section for performing liquid processing by immersing a polymer film in a processing liquid while continuously conveying the polymer film.

  The polymer film is formed by a melt film forming method in which a molten polymer is extruded and then cooled, or a solution film forming method in which a polymer solution is cast on a substrate and then dried. A process of immersing the film in a treatment liquid and applying a liquid treatment to the polymer film thus formed may be applied for the purpose of improving quality or imparting functionality.

  In the case of a film that does not absorb liquid, such as a metal film, no special device is required for transportation in the liquid, but in the case of a polymer film, expansion of the film, change in elastic modulus, and decrease in breaking strength due to liquid absorption. Since physical properties may change, quality troubles may occur under the same conditions as in air for transporting in liquid. In particular, in the case of a thin film shape or a functional polymer film that is easily damaged by the influence of liquid absorption, handling becomes difficult.

  Furthermore, foreign particles caused by adhesion of floating dust during transportation in the air, foreign matter in the immersion treatment liquid or cleaning water, and foreign matter floating on the surface of the treatment liquid in the liquid treatment of the polymer film and subsequent cleaning It is necessary to prevent mixing and generation of pressing scratches between the transport roll and the film. For airborne dust during air transport, measures such as installing in a clean environment and measures such as electrostatic removal of the transport film are taken to prevent the adhering of airborne dust. For foreign matter in the liquid, it is possible to take measures such as filtering the immersion treatment liquid or cleaning water.

  On the other hand, foreign matters floating on the surface of the processing liquid are caused by falling dust or the like having a relatively large size, and thus it is difficult to completely prevent the apparatus even if the apparatus is installed in a clean environment. Since foreign substances that fall on the liquid surface and continue to float are likely to adhere to the polymer film being conveyed, it is necessary to quickly remove the floating foreign substances from the liquid surface.

  A method of constantly overflowing the immersion tank and the cleaning tank is effective for removing floating foreign substances. In patent document 1, in the acidic solution processing at the time of polymer electrolyte membrane production, the liquid treatment is performed in a plurality of immersion tanks filled with the acidic solution while continuously transporting the film, and the acidic solution is moved in the direction opposite to the film transport direction. An apparatus for manufacturing a polymer electrolyte membrane having a liquid processing section that continuously supplies a cascade-type overflow is disclosed.

JP2013-56993A

  The acidic solution processing method disclosed in Patent Document 1 is intended to reduce the amount of novel acidic solution used. In such a method, the amount of overflow from the immersion tank decreases as the amount of the acidic solution used is reduced, and the effect of removing floating foreign matters floating on the liquid surface of the immersion tank is limited. Furthermore, since the acidic solution overflowed from the immersion tank overflows to the adjacent immersion tank one after another, the problem is that the floating foreign matter tends to adhere to the film because the film being transported blocks the movement of the floating foreign matter. There was also.

  The objective of this invention is providing the polymer film manufacturing apparatus which can remove rapidly the floating foreign material of a liquid processing tank.

  The present invention for solving the above problems is a polymer film production apparatus having a liquid treatment unit for performing liquid treatment by immersing a polymer film in a treatment liquid while continuously conveying the polymer film, wherein the liquid treatment unit is a polymer film. An immersion tank for storing a treatment liquid for immersing the liquid, a circulation tank adjacent to the immersion tank, and a treatment liquid supply part for supplying a new treatment liquid. The treatment liquid is first supplied from the treatment liquid supply part to the circulation tank. In addition, the polymer film manufacturing apparatus is configured such that the processing liquid that is fed from the circulation tank to the immersion tank and overflows and flows out of the immersion tank flows into the circulation tank.

  According to the present invention, floating foreign matters are easily and quickly removed from the immersion tank, and foreign matter adhesion to the film is prevented, thereby avoiding film damage caused by foreign matters and improving film quality after liquid treatment. Can do.

It is a figure which shows one Embodiment of the manufacture neglect of this invention. It is a schematic diagram which shows one Embodiment of the film liquid process part of this invention.

  Hereinafter, the polymer film production apparatus of the present invention (hereinafter sometimes simply referred to as “the production apparatus of the present invention”) will be described with reference to the embodiments shown in FIGS. 1 and 2 as appropriate. The form does not limit the present invention.

  The production apparatus of the present invention has a liquid treatment unit for performing liquid treatment by immersing the polymer film in a treatment liquid while continuously conveying the polymer film. Depending on the mode of the liquid treatment, the film during or before the liquid treatment may be strictly a precursor film of a polymer film to be finally produced. These precursor films are also referred to as “polymer film” or simply “film”. During continuous transport, the polymer film may be configured to be transported alone, that is, only in the state of the polymer film, or in a state of being attached to the transport film for the purpose of increasing the strength or for easy handling. You may comprise so that it may convey.

  As shown in FIG. 1, in the present invention, the liquid processing section includes an immersion tank for storing a processing liquid for immersing the polymer film, a circulation tank adjacent to the immersion tank, and a processing liquid supply section for supplying a new processing liquid. Have Then, the treatment liquid is first supplied from the treatment liquid supply unit to the circulation tank, and further fed from the circulation tank to the immersion tank, and the treatment liquid overflowing from the immersion tank (overflowing) flows into the circulation tank. It is configured. When the treatment liquid overflows from the immersion tank to the circulation tank, a flow of the treatment liquid is generated on the liquid surface of the treatment liquid stored in the immersion tank. Therefore, floating foreign substances move to the circulation tank along with the overflow of the processing liquid overflowing, and are removed from the immersion tank.

  The circulation tank is preferably installed adjacent to the immersion tank in a direction orthogonal to the transport direction of the polymer film. By installing in this way, the flow direction when the processing liquid overflowing from the immersion tank flows out into the circulation tank becomes a direction orthogonal to the transport direction of the polymer film. Therefore, the floating foreign material in the immersion tank moves substantially parallel to the film surface and is difficult to adhere to the film surface.

  FIG. 2 (A) is a diagram schematically showing an embodiment of an immersion tank and a circulation tank in the liquid processing section of the production apparatus of the present invention. In this embodiment, the circulation tank 2 is installed adjacent to the immersion tank 1 in a direction orthogonal to the conveying direction of the polymer film F indicated by an arrow in the drawing. And the process liquid first supplied to the circulation tank 2 from the process liquid supply part which is not shown in figure is further sent to the immersion tank 1 with the liquid feeding pump 3, and is used for the liquid process of a polymer film. The upper end of the immersion tank 1 on the side in contact with the circulation tank 2 is lower than the upper end on the opposite side. Therefore, the treatment liquid in the immersion tank overflows from the side wall of the immersion tank and flows into the circulation tank 2 again. Here, since the overflowing processing liquid flows in a direction orthogonal to the transport direction of the polymer film F transported by the transport rollers 4 and 5 and substantially parallel to the film surface of the polymer film F, the floating foreign matter also rides on the flow. It moves substantially parallel to the film surface and is quickly removed from the immersion bath.

  It is preferable that the liquid treatment part further has a shower liquid injection part for showering the treatment liquid on the surface of the polymer film after the liquid treatment in the immersion tank. By having a shower liquid injection part, even if a floating foreign material adheres to the film surface, it can be quickly removed. FIG. 2B shows an embodiment of a liquid processing unit having such a shower liquid injection unit 6. In this embodiment, the shower liquid injecting section 6 is installed so that the processing liquid is showered from both sides of the polymer film F toward the surface of the polymer film F immediately after the polymer film F is pulled up from the immersion tank 1. Has been.

  The liquid processing unit may include a plurality of dipping tanks and use the polymer film for a plurality of times of liquid processing. In this case, it is preferable to have a circulation tank adjacent to each of the plurality of immersion tanks. In the manufacturing apparatus as described in the above-mentioned Patent Document 1, since the liquid processing efficiency is improved and the amount of new processing liquid supply decreases, the overflow amount of the processing liquid also decreases. is there. The liquid processing unit of the manufacturing apparatus of the present invention can adjust the processing liquid supply amount while maintaining the overflow amount of the processing liquid from the immersion tank to the circulation tank. The removal ability does not decrease.

  It is preferable that the liquid processing unit further includes a liquid supply speed adjusting mechanism for adjusting a liquid supply speed from the circulation tank to the immersion tank. Maintaining the ability to remove suspended solids by stopping the circulation of the treatment liquid between the immersion tank and the circulation tank even if the supply of a new treatment liquid is interrupted for some reason by having a liquid feed rate adjustment mechanism Is possible.

  Moreover, it is preferable that a liquid processing part is equipped with a filtration filter in the liquid feeding process from a circulation tank to an immersion tank. Thereby, it can prevent that the floating foreign material removed to the circulation tank from the immersion tank mixes in the immersion tank again. If the filtration filter has sufficient chemical resistance to the treatment liquid, the possibility that the filtration filter itself becomes a foreign matter generation source can be reduced. In addition, when liquid feeding pressure loss arises by providing a filter, it is preferable to adjust with the above-mentioned liquid feeding speed adjustment mechanism.

  The polymer film production apparatus of the present invention preferably has a cleaning section for cleaning the liquid-treated polymer film following the liquid processing section. In the embodiment shown in FIG. 1, the unrolled film is liquid-treated in the immersion tank, and the film is conveyed to the cleaning unit. In order to remove and reduce the treatment liquid adhering to and permeating the film in the washing section, it is preferable to immerse in washing water in multiple stages. It is preferable to use deionized water as the washing water. By using the washing water, impurity ions contained in the washing water can be prevented from penetrating into the film and remaining. Moreover, it is preferable to provide a mechanism for pouring deionized water in multiple stages in the washing section.

  Moreover, it is preferable that the manufacturing apparatus of this invention has a drying part which dries the polymer film after liquid processing, or the polymer film further wash | cleaned by the washing | cleaning part. In the film drying section for drying the washed film, the drying method is not particularly limited, but it is generally preferable to perform hot air drying. In order to improve the drying efficiency, it is more preferable to provide a mechanism in which at least a suction roll whose surface is a porous material is connected to a decompression device, and to remove as much washing water as possible.

  Furthermore, it is preferable that the manufacturing apparatus of this invention is provided with the winding-up part which winds up the said dried film. In order to maintain the roll shape satisfactorily, the winding is preferably provided with a winding mechanism that controls the winding tension to be constant.

  The polymer film production apparatus of the present invention can be applied without particular limitation as long as it is a polymer film that needs to be subjected to liquid treatment by being immersed in a treatment liquid in the production process. Especially, it is suitable for manufacture of ion conductive polymer films, such as an ion exchange membrane and a polymer electrolyte membrane, when the film thickness is thin or often softened and easily damaged by liquid absorption.

  The ion conductive polymer film is a film formed from a polymer in which an ionic group is bonded to the basic skeleton of the polymer. The basic skeleton of such a polymer is not particularly limited, but preferred examples include fluorine-based polymers such as perfluoroalkylene, polyphenylene oxide, polyether ketone, polyether ether ketone, polyether sulfone, and polyether ether sulfone. , Polyether phosphine oxide, polyether ether phosphine oxide, polyphenylene sulfide, polyamide, polyimide, polyether imide, polyimidazole, polyoxazole, and polyphenylene. Moreover, the polymer or copolymer obtained by superposing | polymerizing styrene, ethyl styrene, vinyl pyridine, vinyl pyrazine, divinyl benzene, divinyl toluene, divinyl xylene, trivinyl benzene etc. is also mentioned. The ion conductive film may be reinforced with a porous film or a filler for the purpose of further enhancing the durability.

  In the cation exchange membrane having cation conductivity, a polymer having an anionic group is used, and the anionic group and the cation form an ion pair to have a cation exchange ability. In the anion exchange membrane having anion conductivity, a polymer having a cationic group is used, and the cationic group and the anion form an ion pair to have anion exchange ability.

The anionic group is not particularly limited as long as it has cation exchange ability and exhibits cation conductivity. Preferred examples of the anionic group include a sulfonic acid group (—SO ₂ (OH)), a sulfuric acid group (—OSO ₂ (OH)), and a sulfonimide group (—SO ₂ NHSO ₂ R (R represents an organic group). )), Phosphonic acid groups (—PO (OH) ₂ ), phosphoric acid groups (—OPO (OH) ₂ ), carboxylic acid groups (—CO (OH)), perfluorosulfonic acid groups (—O— (CF _{2) n SO 2 (OH)} ) can be exemplified. Further, the polymer having an anionic group may have two or more of these groups. Since the polymer having an anionic group has high hydrogen ion conductivity, it is more preferable to have any of a sulfonic acid group (including a perfluorosulfonic acid group), a sulfonimide group, a sulfuric acid group, or a phosphonic acid group. From the viewpoint of hydrolysis resistance, it is most preferable to have a sulfonic acid group.

  The cationic group is not particularly limited as long as it has anion exchange ability and exhibits anion conductivity. Preferable examples of the cationic group include a tertiary amino group, a quaternary ammonia group, a tertiary phosphonium group, and a quaternary hostnium group. The polymer having a cationic group may have two or more of these groups. The polymer having a cationic group preferably has either a quaternary ammonia group or a quaternary phosphonium group because of its high hydroxide ion conductivity.

  In general, in the production of an ion conductive film, most of the ionic groups are finally treated with an acid treatment or an alkali treatment at the stage of a precursor film before the ionic group is converted into an ionic form by acid treatment or alkali treatment. It exists in the form of a salt ion-bonded with a counter ion (hereinafter referred to as “impurity ion”) removed by.

  For example, in a polymerization reaction of a polymer having an anionic group or an addition reaction in which an anionic group is introduced into a polymer, a metal cation is used as a catalyst. Remains as. Examples of such metal cations include Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, and W cations. Among them, alkali metal or alkaline earth metal cations are often used. Furthermore, from the viewpoint of cost and environmental load, cations of Li, Na, K, Ca, Sr, and Ba are preferably used, and cations of Li, Na, and K are most preferably used.

  Similarly, in the synthesis reaction of a polymer having a cationic group, an anion (anion) which is a counter ion of a metal cation used as a reaction catalyst and a cationic group in the polymer form an ionic bond, Anions remain as impurity ions in the precursor film. Examples of such anions include sulfate ions, nitrate ions, halogen ions, carbonate ions, and bicarbonate ions. When a cationic group is introduced into a polymer by a polymer reaction, a halogenoalkyl group is often used as a functional group that exchanges with the cationic group. In this case, halogen ions such as chloride ions and fluoride ions are used in the polymer. An ionic bond is formed with the cationic group therein and remains as impurity ions in the precursor film.

  Although not particularly limited, typically, in the precursor film, 50% or more of the ion exchange capacity of the ion conductive film is present in a state of being bonded to impurity ions.

  The production apparatus of the present invention can be preferably used for production of an ion conductive film having a liquid treatment step for bringing such a precursor film into contact with an acid treatment solution or an alkali treatment solution. At this time, in the liquid treatment unit, the precursor film is immersed in the acid treatment solution or the alkali treatment solution while being continuously conveyed. In the liquid processing step, the impurity ions contained in the precursor film are ion exchanged. Typically, a precursor film having an anionic group is liquid-treated with an acidic solution and ion-exchanged with hydrogen ions to form a cation exchange film, and a precursor film having a cationic group is liquid in an alkaline solution. It is processed and ion exchanged with hydroxide ions to form an anion exchange membrane. Alternatively, a precursor film having a cationic group can be liquid-treated with a weak acid solution such as carbonic acid, and ion-exchanged to carbonate ions or hydrogen carbonate ions to form an anion exchange membrane. In the liquid treatment step, ion exchange is performed so that the ionic group present in the salt state is 0.1% or less of the ion exchange capacity of the ion conductive membrane after completion of the plurality of liquid treatment steps of the precursor membrane. It is preferable.

  The acid treatment solution for the cation exchange membrane is not particularly limited as long as it is a dilute solution of strong acid, but an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid is preferable, and sulfuric acid is particularly preferable from the viewpoint of productivity and workability. Is preferred. In order to efficiently convert to hydrogen ions, the acid treatment solution preferably has a hydrogen ion concentration of 1.0 mol / liter (corresponding to pH = 0) or more. For a precursor film having an ionic group density of 1 milliequivalent / g or more, a hydrogen ion concentration of 2.0 mol / liter (corresponding to pH = −0.3) or more is more preferable. That is, the acid treatment solution preferably has a pH = 0 or less, and more preferably has a pH = −0.3 or less for a precursor film having an ionic group density of 1 milliequivalent / g or more. Moreover, it is preferable to use purified water, distilled water, RO water or deionized water from which cationic impurities are removed and reduced as the water used when diluting the strong acid.

F: Polymer film 1: Immersion tank 2: Circulation tank 3: Liquid feed pump 4: Conveyance roller (in liquid)
5: Transport roller (upper part)
6: Shower injection section

Claims (8)

A polymer film production apparatus having a liquid treatment unit for performing liquid treatment by immersing in a treatment liquid while continuously conveying a polymer film,
The liquid processing unit is
An immersion tank for storing a treatment liquid for immersing the polymer film;
A circulation tank adjacent to the immersion tank;
It has a processing liquid supply part that supplies new processing liquid,
The treatment liquid is first supplied from the treatment liquid supply unit to the circulation tank, and further fed from the circulation tank to the immersion tank, and the treatment liquid overflowing and flowing out of the immersion tank flows into the circulation tank. The polymer film manufacturing apparatus comprised as follows. The circulation tank is installed adjacent to the immersion tank in a direction orthogonal to the transport direction of the polymer film, and the flow direction when the treatment liquid overflowing from the immersion tank flows out is the transport direction of the polymer film. The polymer film manufacturing apparatus of Claim 1 which is a direction orthogonal to. The said liquid processing part is a polymer film manufacturing apparatus of Claim 1 or 2 which has a circulation tank adjacent to each immersion tank while having multiple said immersion tanks. The polymer film manufacturing apparatus in any one of Claims 1-3 provided with the liquid feeding speed adjustment mechanism for adjusting the liquid feeding speed from the said circulation tank to the said immersion tank. The polymer film manufacturing apparatus in any one of Claims 1-4 provided with a filtration filter in the liquid feeding process from the said circulation tank to the said immersion tank. The said liquid processing part is a polymer film manufacturing apparatus in any one of Claims 1-5 provided with the shower pouring part which shower-injects a process liquid to the polymer film after liquid processing. The polymer film manufacturing apparatus according to any one of claims 1 to 6, further comprising a cleaning unit that cleans the liquid-treated polymer film following the liquid processing unit. The polymer film production apparatus according to any one of claims 1 to 7, wherein the treatment liquid is an acid treatment solution or an alkali treatment solution, and is used for producing an ion conductive polymer film.

Images