Winding device, film winding method, and method for producing porous imide resin film

Abstract

The invention relates to a winding device, a film winding method, and a method for manufacturing a porous imide resin film. The present invention addresses the problem of effectively suppressing the occurrence of wrinkles and the like during winding. The solution of the present invention is a winding device (80) for a film (F) extending in a band shape, the winding device (80) being provided with a drive roller (81) for winding the film (F), a roller drive unit (82) for rotationally driving the drive roller (81), and a control device (90). The control device (90) controls the roller drive unit (82) such that the drive roller (81) repeatedly rotates and stops driving at a predetermined timing when the drive roller (81) winds up the film (F).

Description

Technical Field

[0001] The present invention relates to a winding device, a film winding method and a method for producing a porous imide resin film. Background Art

[0002] In order to suppress the occurrence of deflection and wrinkles in a long strip of substrate when it is wound up, there is disclosed a structure comprising a winding roller for winding up the substrate, a tension roller that applies tension to the substrate and rotates to convey the substrate to the winding roller, and a tension changing section that adjusts the tension of the substrate in the tension roller (for example, see patent document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-226510 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The content described in Patent Document 1 has a problem that, when the object to be wound is a thin film, a soft film, or the like, the generation of wrinkles or the like during winding cannot be sufficiently suppressed.

[0008] An object of the present invention is to provide a winding device, a film winding method, and a method for producing a porous imide resin film, which can effectively suppress the generation of wrinkles and the like during winding.

[0009] Means for solving problems

[0010] In the first embodiment of the present invention, a winding device can be provided, which is a winding device for a film extending in a strip shape, and the winding device comprises: a driving roller, which winds up the film; a roller driving unit, which drives the driving roller to rotate; and a control device, which controls the roller driving unit in such a way that the driving roller repeatedly rotates and stops driving at a specified timing when the driving roller winds up the film.

[0011] In a second aspect of the present invention, a film winding method can be provided, which is a method for winding a film extending in a strip shape using a driving roller, the film winding method comprising the step of repeatedly rotating and stopping the driving roller at a predetermined timing when winding the film.

[0012] In the third embodiment of the present invention, a method for manufacturing a porous imide resin film can be provided, which comprises the following steps: a first step of coating a coating liquid containing microparticles on a substrate and then drying the coating liquid to form a strip-shaped unfired film; a second step of firing the unfired film and removing the microparticles to form a strip-shaped porous imide resin film; and a third step of performing a chemical etching treatment to dissolve a portion of the porous imide resin film, wherein the manufacturing method comprises a step of implementing the film winding method involved in the above-mentioned second embodiment when winding up at least one of the unfired film and the porous imide resin film.

[0013] Effects of the Invention

[0014] According to the above-mentioned method of the present invention, when the driving roller is winding up the film, the driving roller repeatedly rotates and stops the driving at a predetermined timing, so the tension acting on the film is relaxed during the driving stop period, thereby suppressing the tension from acting locally on the film. As a result, when the driving roller is subsequently driven to rotate, wrinkles, etc. are not easily generated in the film. As a result, the generation of wrinkles, etc. during winding can be effectively suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] [ Figure 1 ] is a diagram showing an example of a manufacturing system having a winding device involved in an embodiment.

[0016] [ Figure 2 ] is a diagram showing a schematic structure of an unfired film forming unit of a manufacturing system.

[0017] [ Figure 3 ] is a diagram showing the schematic structure of the sintering and particle removal unit of the manufacturing system.

[0018] [ Figure 4 ] is a diagram showing the schematic structure of the etching unit of the manufacturing system.

[0019] [ Figure 5 ] is a diagram showing the structure of the slitting machine of the manufacturing system.

[0020] [ Figure 6 ] is a diagram showing the structure of the winding device of the manufacturing system.

[0021] [ Figure 7 ] is a block diagram showing the functional structure of the control device of the winding device.

[0022] [ Figure 8 ] is a flow chart showing an example of a process for producing a porous imide resin film according to an embodiment of the present invention.

[0023] [ Fig. 9 ] is a diagram showing an example of a manufacturing process of a porous imide resin film.

[0024] [ Fig.10 ] is a diagram showing an example of a manufacturing process of a porous imide resin film.

[0025] [ Fig.11 ] is a flowchart showing an example of a process of a film winding method involved in an embodiment.

[0026] Description of Reference Numerals

[0027] 7···winding device, 81···driving roller, 82···roller driving unit, 90···control device, F···porous imide resin film, FA···unsintered film, S···substrate, S1···first step, S2···second step, S3···third step DETAILED DESCRIPTION

[0028] Hereinafter, the embodiments are described with reference to the accompanying drawings. However, the present invention is not limited to the contents described below. In addition, in the accompanying drawings, in order to make the various components of the embodiments easy to understand, a part is enlarged or emphasized, or a part is simplified, and sometimes the actual structure or shape, scale, etc. are different. Hereinafter, the directions in the figure are described using the XYZ coordinate system. In the XYZ coordinate system, the plane parallel to the horizontal plane is referred to as the XY plane. A direction parallel to the XY plane is expressed as the X direction, and a direction orthogonal to the X direction is expressed as the Y direction. In addition, the direction perpendicular to the XY plane is expressed as the Z direction. The X direction, the Y direction, and the Z direction are each described with the direction indicated by the arrow in the figure as the + direction and the direction opposite to the direction indicated by the arrow as the - direction.

[0029] Figure 1 This is a diagram showing an example of a manufacturing system 1 including a winding device 7 according to the present embodiment. Figure 2 It is a diagram showing a schematic configuration of an unfired film forming unit of the manufacturing system. Figure 3 This is a diagram showing a schematic configuration of a sintering and fine particle removal unit of the manufacturing system. Figure 4 A diagram showing a schematic configuration of an etching unit in a manufacturing system. Figure 5 A diagram showing the configuration of a slitting machine in a manufacturing system. Figure 1 The manufacturing system 1 shown manufactures a porous imide resin film F. The manufacturing system 1 includes an unfired film forming unit 2, a firing and particle removal unit 3, an etching unit 4, a slitter 5, and a system control device not shown. In the manufacturing system 1, the porous imide resin film F is manufactured by sequentially passing through the unfired film forming unit 2, the firing and particle removal unit 3, the etching unit 4, and the slitter 5 in the following order.

[0030] Figure 1 , Figure 2 The unfired film forming unit 2 shown forms a strip-shaped unfired film FA by applying a coating liquid containing fine particles on a substrate S and then drying the coating liquid. Figure 1 , Figure 3 The calcination and particle removal unit 3 shown in the figure calcines the uncalcined film FA to remove the particles, thereby forming a belt-shaped porous imide-based resin film F. Figure 1 , Figure 4 The etching unit 4 shown performs a chemical etching process for dissolving a part of the porous imide resin film F. Figure 1 , Figure 5 The slitter 5 shown cuts the porous imide resin film F into strips having a predetermined product width. The system control device comprehensively controls the entire manufacturing system 1 .

[0031] In this embodiment, the unfired film forming unit 2, the firing and particle removal unit 3, the etching unit 4, and the slitter 5 are arranged to be separated from each other. In such a manufacturing system 1, the intermediate product being manufactured is wound into a roll and transported as described in detail later between the unfired film forming unit 2 and the firing and particle removal unit 3, between the firing and particle removal unit 3 and the etching unit 4, and between the etching unit 4 and the slitter 5. It should be noted that the units in which the processes are performed successively in the unfired film forming unit 2, the firing and particle removal unit 3, and the etching unit 4 can also be arranged continuously.

[0032] [Coating liquid]

[0033] Here, before describing each part of the manufacturing system 1, the porous imide resin film F manufactured by the manufacturing system 1 is described. The coating liquid that becomes the raw material of the porous imide resin film F contains a predetermined resin material, particles, and a solvent. As the predetermined resin material, for example, polyamic acid, polyimide, polyamide-imide, or polyamide can be cited. As the solvent, an organic solvent that can dissolve these resin materials can be used.

[0034] The coating liquid can be prepared, for example, by mixing a solvent in which microparticles are pre-dispersed with polyamic acid, polyimide, polyamide-imide or polyamide in an arbitrary ratio. In addition, polyamic acid, polyimide, polyamide-imide or polyamide can also be prepared by polymerization in a solvent in which microparticles are pre-dispersed. For example, it can be manufactured in the following manner: tetracarboxylic dianhydride and diamine are polymerized in an organic solvent in which microparticles are pre-dispersed to make polyamic acid, or further imidization is performed to make polyimide.

[0035] The final viscosity of the coating liquid is preferably 100 to 7000 cP, more preferably 300 to 5000 cP, and even more preferably 500 to 3000 cP. When the viscosity of the coating liquid is within this range, uniform film formation can be performed.

[0036] In the above-mentioned coating liquid, when the microparticles and polyamic acid or polyimide are dried to form an unfired film FA, when the material of the microparticles is an inorganic material described later, the microparticles and polyamic acid or polyimide can be mixed in a manner that the ratio of microparticles / polyimide is 1 to 4 (mass ratio). It is further preferably set to 1.2 to 3 (mass ratio). When the material of the microparticles is an organic material described later, the microparticles and polyamic acid or polyimide can be mixed in a manner that the ratio of microparticles / polyimide is 0.5 to 2 (mass ratio). It is further preferably set to 0.6 to 1.5 (mass ratio). In addition, the microparticles and polyamic acid or polyimide can be mixed in a manner that the volume ratio of microparticles / polyimide is 0.6 to 2.7 when the unfired film FA is formed. It is further preferably set to 0.8 to 2 (volume ratio). If the mass ratio or volume ratio of microparticles / polyimide is above the lower limit when making the unfired film FA, a hole with a density suitable for the diaphragm can be obtained, and if it is below the upper limit, problems such as an increase in viscosity and cracks in the film will not occur, and the film can be stably formed. In the case where the resin material is polyamide-imide or polyamide instead of polyamic acid or polyimide, the mass ratio is also the same as above.

[0037] Hereinafter, each resin material will be described in detail.

[0038] <Polyamic acid>

[0039] The polyamic acid used in the present embodiment can be obtained by polymerizing any tetracarboxylic dianhydride and diamine without particular limitation. The amount of tetracarboxylic dianhydride and diamine used is not particularly limited, and it is preferred to use 0.50 to 1.50 mol of diamine, more preferably 0.60 to 1.30 mol of diamine, and particularly preferably 0.70 to 1.20 mol of diamine relative to 1 mol of tetracarboxylic dianhydride.

[0040] Tetracarboxylic dianhydride can be suitably selected from tetracarboxylic dianhydride used as the synthetic raw material of polyamic acid in the past.Tetracarboxylic dianhydride can be aromatic tetracarboxylic dianhydride or aliphatic tetracarboxylic dianhydride, but from the aspect of the heat resistance of the obtained polyimide resin, aromatic tetracarboxylic dianhydride is preferably used.Tetracarboxylic dianhydride can also be used in combination of two or more.

[0041] Preferred specific examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2,6,6-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 3 ,3',4,4'-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 4,4-(p-phenylenedioxy)diphthalic dianhydride, 4,4-(isophenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,3,4-pyromellitic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-diphthalic anhydride fluorene, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, etc. Examples of the aliphatic tetracarboxylic dianhydride include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, and 1,2,3,4-cyclohexanetetracarboxylic dianhydride. Among them, 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferred in view of price, availability, etc. In addition, these tetracarboxylic dianhydrides may be used alone or in combination of two or more.

[0042] The diamine can be suitably selected from diamines used as synthetic raw materials for polyamic acid in the past. The diamine can be an aromatic diamine or an aliphatic diamine, but from the aspect of the heat resistance of the obtained polyimide resin, an aromatic diamine is preferred. These diamines can also be used in combination of two or more.

[0043] Examples of the aromatic diamine include diamino compounds to which 1 or 2 to 10 phenyl groups are bonded, specifically phenylenediamine and its derivatives, diaminobiphenyl compounds and their derivatives, diaminodiphenyl compounds and their derivatives, diaminotriphenyl compounds and their derivatives, diaminonaphthalene and its derivatives, aminophenylaminoindanes and their derivatives, diaminotetraphenyl compounds and their derivatives, diaminohexaphenyl compounds and their derivatives, and Cardo-type fluorenediamine derivatives.

[0044] Phenylenediamine includes meta-phenylenediamine, para-phenylenediamine and the like. Phenylenediamine derivatives include diamines to which an alkyl group such as a methyl group or an ethyl group is bonded, for example, 2,4-diaminotoluene, 2,4-triphenylenediamine and the like.

[0045] The diaminobiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via a phenyl group, and examples thereof include 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

[0046] The diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other through phenyl groups via other groups. The bond is an ether bond, a sulfonyl bond, a thioether bond, a bond based on an alkylene group or a derivative group thereof, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, a ureylene bond, etc. The alkylene bond is a bond having about 1 to 6 carbon atoms, and its derivative group is a group in which one or more hydrogen atoms of the alkylene group are replaced by halogen atoms or the like.

[0047] Examples of the diaminodiphenyl compound include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2-bis(p-aminophenyl)propane, 2,2'-bis(p-aminophenyl)hexafluoropropane, 4-methyl-2,4-bis(p-aminophenyl)-1-pentene, 4-methyl-2,4-bis(p-aminophenyl)-1-pentene, and 4-methyl-2,4-bis(p-aminophenyl)-1-pentene. Bis(p-aminophenyl)-2-pentene, iminodiphenylamine, 4-methyl-2,4-bis(p-aminophenyl)pentane, bis(p-aminophenyl)phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenyl urea, 4,4'-diaminodiphenylamide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, etc.

[0048] Among them, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4′-diaminodiphenyl ether are preferred in view of price, availability, and the like.

[0049] The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are bonded via other groups, and the other groups can be selected from the same groups as the diaminodiphenyl compound. Examples of the diaminotriphenyl compound include 1,3-bis(m-aminophenoxy)benzene, 1,3-bis(p-aminophenoxy)benzene, and 1,4-bis(p-aminophenoxy)benzene.

[0050] Examples of diaminonaphthalene include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

[0051] Examples of aminophenylaminoindan include 5- or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindan.

[0052] Examples of the diaminotetraphenyl compound include 4,4'-bis(p-aminophenoxy)biphenyl, 2,2'-bis[p-(p'-aminophenoxy)phenyl]propane, 2,2'-bis[p-(p'-aminophenoxy)biphenyl]propane, and 2,2'-bis[p-(m-aminophenoxy)phenyl]benzophenone.

[0053] Examples of the Cardo-type fluorene diamine derivative include 9,9-dianiline fluorene and the like.

[0054] The aliphatic diamine may be, for example, a diamine having about 2 to 15 carbon atoms, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

[0055] In addition, the compound in which the hydrogen atom of these diamines is substituted with at least one substituent selected from the group consisting of a halogen atom, a methyl group, a methoxy group, a cyano group, a phenyl group, etc. may be sufficient.

[0056] The method for producing the polyamic acid used in the present embodiment is not particularly limited, and for example, a known method such as a method of reacting an acid and a diamine component in an organic solvent can be employed.

[0057] The reaction of tetracarboxylic dianhydride and diamine is usually carried out in an organic solvent. The organic solvent used in the reaction of tetracarboxylic dianhydride and diamine is not particularly limited as long as it can dissolve tetracarboxylic dianhydride and diamine and does not react with tetracarboxylic dianhydride and diamine. The organic solvent can be used alone or in combination of two or more.

[0058] Examples of the organic solvent used in the reaction of tetracarboxylic dianhydride and diamine include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N',N'-tetramethylurea; lactone-based polar solvents such as β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, and ε-caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate, and ethyl cellosolve acetate; and phenolic solvents such as cresols. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent used is not particularly limited, but it is desirable that the content of the generated polyamic acid is 5 to 50% by mass.

[0059] Among these organic solvents, nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N',N'-tetramethylurea are preferred in view of the solubility of the generated polyamic acid.

[0060] The polymerization temperature is usually -10 to 120°C, preferably 5 to 30°C. The polymerization time varies depending on the composition of the raw materials used, but is usually 3 to 24 hours. In addition, the intrinsic viscosity of the organic solvent solution of the polyamic acid obtained under such conditions is preferably in the range of 1000 to 100,000 cP (centipoise), and more preferably in the range of 5000 to 70,000 cP.

[0061] <Polyimide>

[0062] The polyimide used in this embodiment is not limited in structure and molecular weight as long as it is a soluble polyimide that can be dissolved in an organic solvent used in the coating solution, and a known polyimide can be used. For the polyimide, a functional group capable of condensation such as a carboxyl group or a functional group that promotes a crosslinking reaction during calcination can be provided on the side chain.

[0063] In order to prepare a polyimide soluble in an organic solvent, it is effective to use a monomer for introducing a flexible curved structure into the main chain, for example, the following monomers: aliphatic diamines such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, and 4,4'-diaminodicyclohexylmethane; aromatic diamines such as 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, and 4,4'-diaminobenzanilide; polyoxyalkylene diamines such as polyoxyethylene diamine, polyoxypropylene diamine, and polyoxybutylene diamine; polysiloxane diamine; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, 2,2-bis(4-hydroxyphenyl)propane dibenzoate-3,3',4,4'-tetracarboxylic dianhydride, and the like. In addition, the use of monomers having functional groups that improve solubility in organic solvents, such as 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2-trifluoromethyl-1,4-phenylenediamine and other fluorodiamines is also effective. In addition, in addition to the monomers used to improve the solubility of the above-mentioned polyimide, the same monomers as those described in the above-mentioned polyamic acid column can also be used in combination within the range that does not inhibit solubility.

[0064] The means for making the polyimide soluble in an organic solvent used in the present embodiment is not particularly limited, for example, known methods such as chemical imidization or heating imidization of polyamic acid and dissolving it in an organic solvent can be adopted. As such polyimide, aliphatic polyimide (all aliphatic polyimide), aromatic polyimide, etc. can be cited, preferably aromatic polyimide.

[0065] <Polyamide-imide>

[0066] The polyamide-imide used in this embodiment is not limited in structure and molecular weight as long as it is a soluble polyamide-imide that can be dissolved in an organic solvent used in the coating solution, and known polyamide-imides can be used. For the polyamide-imide, a functional group capable of condensation such as a carboxyl group or a functional group that promotes a cross-linking reaction during calcination can be provided on the side chain.

[0067] The polyamideimide used in the present embodiment can be used without particular limitation. A polyamideimide obtained by reacting any trimellitic anhydride with diisocyanate, or a polyamideimide obtained by imidizing a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride with diamine can be used.

[0068] Examples of the above-mentioned optional trimellitic anhydride or a reactive derivative thereof include trimellitic anhydride, trimellitic anhydride halides such as trimellitic anhydride chloride, and trimellitic anhydride esters.

[0069] Examples of the diisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-oxybis(phenylisocyanate), 4,4′-diisocyanate diphenylmethane, bis[4-(4-isocyanate phenoxy)phenyl]sulfone, and 2,2′-bis[4-(4-isocyanate phenoxy)phenyl]propane.

[0070] Examples of the diamine include the same diamines as those exemplified in the description of the polyamic acid described above.

[0071] <Polyamide>

[0072] As the polyamide, a polyamide obtained from a dicarboxylic acid and a diamine is preferred, and an aromatic polyamide is particularly preferred.

[0073] Examples of the dicarboxylic acid include maleic acid, fumaric acid, itaconic acid, methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, phthalic acid, isophthalic acid, terephthalic acid, and biphenylcarboxylic acid.

[0074] As the diamine, there may be mentioned the same diamines as those exemplified in the description of the polyamic acid described above.

[0075] <Microparticles>

[0076] Next, the microparticles are described. For example, microparticles having a high sphericity and a small particle size distribution index can be used. Such microparticles have excellent dispersibility in liquid and are in a state of not agglomerating with each other. The particle size (average diameter) of the microparticles can be set to, for example, about 5 to 3000 nm. By using such microparticles as described above, the pore size of the porous imide resin film F obtained by removing the microparticles in a subsequent process can be made uniform. Therefore, the electric field applied to the diaphragm formed by the porous imide resin film F can be made uniform.

[0077] It should be noted that as the material of the microparticles, as long as it is insoluble in the solvent contained in the coating solution and can be removed from the porous imide resin film F in the subsequent process, a known material can be used without particular limitation. For example, among inorganic materials, metal oxides such as silica, titanium oxide, and aluminum oxide (Al2O3) can be cited. In addition, among organic materials, organic polymer microparticles such as high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene, epoxy resin, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polymethyl methacrylate, and polyether can be cited. In addition, as an example of microparticles, colloidal silica, calcium carbonate, etc. such as (monodispersed) spherical silica particles can be cited. In this case, the pore size of the porous imide resin film F can be made more uniform.

[0078] It should be noted that the coating liquid may contain various additives such as a release agent, a dispersant, a condensing agent, an imidizing agent, a surfactant, etc., in addition to the predetermined resin material, fine particles, and a solvent, as required.

[0079] [Unfired film forming unit]

[0080] like Figure 2 As shown, the unfired film forming unit 2 is provided with a substrate supply unit 21, a coating unit 22, a drying unit 23, a separation unit 24, a substrate winding unit 25, and a product winding unit 26 on a floor surface 8. The substrate supply unit 21 unwinds the substrate S extending in a strip shape. Here, as the material of the substrate S, for example, polyethylene terephthalate (PET) can be cited, but it is not limited to this structure, and it can also be a metal material such as stainless steel. The substrate S is arranged on a supply roller 21r in a state of a substrate roll Sr wound into a roll shape. The substrate supply unit 21 unwinds the substrate S from the substrate roll Sr.

[0081] The substrate S can be unwound from the substrate roll Sr by winding it up using, for example, a winding roller 25r provided in the substrate winding section 25 described later. The substrate S can be conveyed to the coating section 22, the drying section 23, and the substrate winding section 25 at a predetermined conveying speed via a plurality of intermediate rollers. The coating section 22 applies a coating liquid containing microparticles on the substrate S supplied by the substrate supply section 21. The coating section 22 sprays a pre-prepared coating liquid from, for example, a nozzle onto the substrate S conveyed at a predetermined speed, thereby forming a strip-shaped unfired film FA on the substrate S. Here, there is no limitation on the configuration for applying the coating liquid on the substrate S using the coating section 22, and various known configurations can be adopted.

[0082] The substrate S formed with the unfired film FA by the coating unit 22 is supplied to the drying unit 23. The drying unit 23 removes the solvent contained in the unfired film FA. The drying unit 23 may be, for example, a method of sequentially passing the unfired film FA through a plurality of drying furnaces having different heating temperatures. By passing through the drying unit 23, the solvent is removed from the unfired film FA on the substrate S. The substrate S and the unfired film FA that have passed through the drying unit 23 are conveyed to the separation unit 24. The separation unit 24 separates the substrate S from the unfired film FA. The substrate S separated in the separation unit 24 is conveyed to the substrate winding unit 25. The unfired film FA separated from the substrate S in the separation unit 24 is conveyed to the product winding unit 26.

[0083] The substrate winding section 25 winds up the substrate S onto a core provided on a winding roller 25r. The winding roller 25r is driven to rotate at a predetermined speed by a motor not shown in the figure. In addition, the product winding section 26 winds up the unfired film FA separated from the substrate S onto a core provided on a winding roller 26r. The winding roller 26r is driven to rotate at a predetermined speed by a motor not shown in the figure. By operating as described above, an unfired film roll FAr obtained by winding up the unfired film FA is generated. The generated unfired film roll FAr is transported to the sintering and particle removal unit 3 by, for example, an operator or manual operation using a transport trolley, a manipulator, a bridge crane, etc.

[0084] [Firing and particle removal unit]

[0085] like Figure 3 As shown, the sintering and particle removal unit 3 includes an unwinding section 31, a sintering furnace 33, a first etching section 34, a washing section 35, a drying section 36, and a winding section 37 on a floor surface 8. The unwinding section 31 unwinds the unsintered film FA extending in a strip shape from the unsintered film roll FAr. The unwinding roller 31r of the unwinding section 31 is provided with an unsintered film roll FAr obtained by winding the unsintered film FA into a roll shape. The unwinding section 31 unwinds the unsintered film FA from the unsintered film roll FAr. The unsintered film FA can be unwound from the unsintered film roll FAr by, for example, winding it using a winding roller 37r provided in the winding section 37 described later.

[0086] The unfired film FA is conveyed to the winding section 37 at a predetermined conveying speed through the firing furnace 33, the first etching section 34, the cleaning section 35, and the drying section 36. It should be noted that in the present embodiment, the unfired film FA is conveyed at a predetermined conveying speed by a conveyor, for example, not shown, provided in the first etching section 34 described later, in addition to being conveyed by the winding roller 37r.

[0087] The firing furnace 33 fires the unfired film FA to imidize the resin material in the coating liquid to form a fired film FB containing particles. The firing furnace 33 heats the unfired film FA to, for example, about 120°C to 450°C using an infrared heater or the like while conveying the unfired film FA at a predetermined conveying speed in a chamber. The first etching unit 34 etches the fired film FB to remove the particles contained in the fired film FB to form a porous imide resin film F. The first etching unit 34 removes the particles by, for example, immersing the fired film FB in an etching solution that can dissolve or decompose the particles. As the etching solution, for example, a hydrofluoric acid solution can be used. The first etching unit 34 immerses the fired film FB in an etching tank (not shown) storing the etching solution while conveying it at a predetermined conveying speed. As a result, the particles contained in the fired film FB are dissolved and removed.

[0088] When the particles are removed as described above, cavities are formed in the portions where the particles exist, thereby forming a porous imide resin film F. In addition, the first etching unit 34 may be provided with, for example, a conveyor that supports and conveys the fired film FB from below.

[0089] The washing section 35 washes the porous imide resin film F formed by the first etching section 34 with a washing liquid. The method used for washing the porous imide resin film F in the washing section 35 is not limited to this configuration. The drying section 36 dries the washed porous imide resin film F by various known methods. The drying section 36 heats the porous imide resin film F that has passed through the washing section 35, for example, to volatilize the washing liquid remaining in the porous imide resin film F. Here, at least one of the washing section 35 and the drying section 36 may be provided with a conveyor that supports the porous imide resin film F from below and conveys it.

[0090] The winding section 37 winds up the porous imide resin film F onto a winding core provided on a winding roller 37r. The winding roller 37r is driven to rotate at a predetermined speed by a motor (not shown). The porous resin film roll Fr obtained by winding up the porous imide resin film F is produced by the above-described operation. The produced porous resin film roll Fr is transported to the etching unit 4 by, for example, an operator or manual operation using a transport trolley, a manipulator, a bridge crane, or the like.

[0091] [Etching Unit 4]

[0092] like Figure 4 As shown, the etching unit 4 includes an unwinding section 41, a second etching section 42, a washing section 43, a drying section 44, a re-firing furnace 45, an inspection section 46, a measuring section 47, and a winding section 48 on a floor surface 8. The unwinding section 41 unwinds the porous imide resin film F extending in a strip shape from the porous resin film roll Fr. The porous resin film roll Fr obtained by winding the porous imide resin film F into a roll shape is provided on the unwinding roller 41r of the unwinding section 41. The unwinding section 41 unwinds the porous imide resin film F from the porous resin film roll Fr. The porous imide resin film F can be unwound from the porous resin film roll Fr by winding it using, for example, a winding roller 48r provided in the winding section 48 described later.

[0093] The unwound porous imide resin film F is conveyed to the winding section 48 at a predetermined conveying speed through the second etching section 42, the washing section 43, the drying section 44, the re-firing furnace 45, the inspection section 46, and the measuring section 47. It should be noted that in the present embodiment, the porous imide resin film F is conveyed at a predetermined conveying speed by the winding roller 48r.

[0094] The second etching section 42 performs chemical etching on the porous imide resin film F. When the microparticles contained in the porous imide resin film F are removed by the etching process in the first etching section 34, minute burr-like irregularities protruding from the periphery of the hole are formed on the surface of the porous imide resin film F due to the escape of the microparticles. In the second etching section 42, the irregularities on the periphery of the hole are flattened by performing chemical etching.

[0095] As the etching liquid for chemical etching in the second etching section 42, for example, a sodium hydroxide aqueous solution or a TMAH (tetramethylammonium hydroxide) aqueous solution can be used. The second etching section 42 immerses the porous imide resin film F in an etching tank (not shown) storing the etching liquid while conveying it at a predetermined conveying speed. As a result, the concavoconvexity around the hole formed in the porous imide resin film F is dissolved or softened, and the surface of the porous imide resin film F is flattened. It should be noted that a conveyor that supports the porous imide resin film F from the bottom and conveys it can also be provided in the second etching section 42.

[0096] The washing section 43 washes the porous imide resin film F that has passed through the second etching section 42 with a washing liquid. The method used for washing the porous imide resin film F in the washing section 43 is not limited to this configuration. The drying section 44 dries the washed porous imide resin film F using various known methods. The drying section 44 heats the porous imide resin film F that has passed through the washing section 43, for example, to volatilize the washing liquid remaining in the porous imide resin film F. Here, at least one of the washing section 43 and the drying section 44 may include a conveyor that supports the porous imide resin film F from below and conveys it.

[0097] The re-firing furnace 45 re-firings the porous imide resin film F. The resin components and the like that are not imidized in the above-mentioned sintering furnace 33 and remain in the porous imide resin film F are imidized by the re-firing furnace 45. The re-firing furnace 45 heats the porous imide resin film F to, for example, about 300° C. to 400° C. by using an infrared heater or the like while conveying the porous imide resin film F at a predetermined conveying speed in a chamber.

[0098] The inspection unit 46 inspects the quality of the porous imide resin film F that has passed through the re-firing furnace 45. The inspection unit 46, for example, inspects the porous imide resin film F for foreign matter. The inspection unit 46, for example, may also inspect the generation of pinholes in the porous imide resin film F. The inspection unit 46, for example, irradiates the porous imide resin film F with light using an unillustrated lighting device while photographing the porous imide resin film F using an unillustrated camera. The inspection unit 46 performs image analysis on the photographed image (video) to determine whether the generation of foreign matter or pinholes falls within the inspection criteria. It should be noted that there is no limitation on the inspection content and inspection method in the inspection unit 46.

[0099] The measuring unit 47 measures the size of the porous imide resin film F. The measuring unit 47 measures, for example, the film thickness of the porous imide resin film F. The measuring unit 47 may also measure other sizes such as the width of the porous imide resin film F. The measuring unit 47 determines whether the measured size of the porous imide resin film F falls within the size standard. There is no limitation on the measurement content and measurement method in the measuring unit 47. In addition, there is no particular limitation on the inspection of the inspection unit 46, the measurement results of the measuring unit 47, the inspection standard, and the operation outside the measurement standard.

[0100] The winding section 48 winds the porous imide resin film F onto a winding core provided on a winding roller 48r. The winding roller 48r is driven to rotate at a predetermined speed by a motor (not shown). The above operation generates a finished roll Fm obtained by winding the porous imide resin film F. The generated finished roll Fm is transported to the slitting machine 5 by, for example, an operator or manual operation using a transport trolley, a manipulator, a bridge crane, etc.

[0101] [Slitting machine]

[0102] like Figure 5 As shown, the slitter 5 cuts the strip-shaped porous imide resin film F that has passed through the etching unit 4 into a predetermined width. The slitter 5 includes an unwinding section 51, a cutting section 52, a product winding section 53, and an excess portion winding section 54. The unwinding roller 51r of the unwinding section 51 unwinds the porous imide resin film F extending in a strip shape from the finished product roll Fm.

[0103] The cutting unit 52 cuts the strip-shaped porous imide resin film F into a plurality of strips along the extending direction (longitudinal direction) of the film. The cutting unit 52 divides the strip-shaped porous imide resin film F into a plurality of strips along the width direction. For example, the cutting unit 52 cuts the porous imide resin film F using a disk-shaped cutter 52c while conveying the strip-shaped porous imide resin film F along the extending direction of the strip-shaped porous imide resin film F.

[0104] At this time, the porous imide resin film F is cut out from the middle portion in the width direction of the porous imide resin film F formed with a predetermined width in accordance with the product width. The porous imide resin film Fp having the predetermined product width cut out from the middle portion in the width direction of the porous imide resin film F may be one or more. In addition, both ends in the width direction of the porous imide resin film F are not used as the product, but are cut out from the porous imide resin film Fp as extra porous imide resin film Fy.

[0105] The product winding section 53 winds up the porous imide resin film Fp having a predetermined product width cut out from the cutting section 52. In the present embodiment, for example, two porous imide resin films Fp are cut out from the porous imide resin film F before cutting. Therefore, two sets of product winding sections 53 are provided. The product winding section 53 winds up the porous imide resin film Fp onto a winding core provided on a winding roller 53r. The winding roller 53r is driven to rotate at a predetermined speed set in advance by a motor not shown in the figure. By operating as described above, a product roll Fpr obtained by winding up the porous imide resin film Fp is generated.

[0106] The excess winding section 54 winds up the excess porous imide resin film Fy cut off from the porous imide resin film F before cutting. The excess winding section 54 winds up the excess porous imide resin film Fy onto a winding core provided on a winding roller 54r. The winding roller 54r is driven to rotate at a predetermined speed set in advance by a motor not shown in the figure. By operating as described above, an excess roll Fyr obtained by winding up the excess porous imide resin film Fy is generated. By operating as described above, the product roll Fpr and the excess roll Fyr generated by the slitting machine 5 are carried out from the slitting machine 5 by, for example, an operator or manual operation using a conveying trolley, a manipulator, a bridge crane, etc.

[0107] [Rewinding device]

[0108] like Figure 6 As shown, the winding device 7 can be used, for example, in the winding section 48 of the etching unit 4. The winding device 7 can also be used in the winding section 37 of the sintering and particle removal unit 3. The winding device 7 includes a base 71, an introduction section 72, a plurality of guide rollers 73, a tension adjustment section 74, a winding mechanism 80, and a control device 90.

[0109] The base 71 is provided on the floor surface 8. The introduction part 72, the plurality of guide rollers 73, the tension adjustment part 74, and the winding mechanism 80 are provided on the base 71. The introduction part 72 introduces the porous imide resin film F from the upstream side in the conveying direction of the porous imide resin film F (film) into the winding device 7. The introduction part 72 has a pair of upper and lower introduction rollers 72a and 72b. The porous imide resin film F is introduced in a manner of being sandwiched between the pair of introduction rollers 72a and 72b.

[0110] The plurality of guide rollers 73 guide the porous imide resin film F introduced from the introduction section 72 to the winding mechanism 80 through the tension adjustment section 74. In the present embodiment, guide rollers 73a to 73k are provided as the plurality of guide rollers 73. The guide rollers 73a to 73k are each provided on a supporting member (not shown) provided on the base 71 so as to be rotatable around an axis extending in the X direction.

[0111] The outer peripheral surface of each guide roller 73a to 73k contacts the porous imide resin film F that is wound up by the driving roller 81 of the winding mechanism 80 described later. Each guide roller 73a to 73k is a driven roller that is driven by the friction force generated between the porous imide resin film F that is conveyed in the extending direction thereof. The guide rollers (driven rollers) 73a to 73k apply a predetermined tension to the porous imide resin film F.

[0112] The guide roller 73a is provided at a distance in the +Y direction relative to the pair of introduction rollers 72a and 72b. The guide roller 73a guides the porous imide resin film F fed from the introduction portion 72 in the +Y direction toward the guide roller 73b provided at a distance obliquely below. The guide roller 73b guides the porous imide resin film F toward the guide roller 73c provided at a distance in the -Z direction. The guide roller 73c guides the porous imide resin film F toward the guide roller 73d provided at a distance in the +Y direction.

[0113] The guide roller 73d guides the porous imide resin film F toward the first tension roller 74a provided at intervals in the -Y direction and the +Z direction. The first tension roller 74a guides the porous imide resin film F toward the guide roller 73e provided at intervals in the +Y direction and the +Z direction. The guide roller 73e guides the porous imide resin film F toward the second tension roller 74b provided at intervals in the -Y direction and the +Z direction. The second tension roller 74b guides the porous imide resin film F toward the guide roller 73f provided at intervals in the +Y direction and the +Z direction. The guide roller 73f guides the porous imide resin film F toward the guide roller 73g provided at intervals in the -Y direction and the +Z direction.

[0114] The guide roller 73g guides the porous imide resin film F toward the guide roller 73h disposed at a distance in the +Y direction. The guide roller 73i is disposed on the upper side of the guide roller 73h in an opposed manner. The porous imide resin film F passes between the guide rollers 73h and 73i and is guided toward the guide roller 73j disposed at a distance in the -Z direction. The guide roller 73j guides the porous imide resin film F toward the guide roller 73k disposed at a distance in the +Y direction. The guide roller 73k guides the porous imide resin film F toward the drive roller 81 disposed at a distance in the +Y direction and the +Z direction.

[0115] The tension adjusting unit 74 adjusts the tension introduced into the porous imide resin film F fed to the winding mechanism 80. In the present embodiment, the tension is preferably adjusted by the tension adjusting unit 74 so as to introduce a tension of, for example, 4 to 10 N into the porous imide resin film F. The tension adjusting unit 74 includes a first tension roller 74a, a second tension roller 74b, and a support arm 74c.

[0116] The first tension roller 74a and the second tension roller 74b are provided on the support arm 74c so as to be rotatable about an axis extending in the X direction. The outer peripheral surface of each of the first tension roller 74a and the second tension roller 74b is in contact with the porous imide resin film F. Each of the first tension roller 74a and the second tension roller 74b is a driven roller driven by the friction force generated between the first tension roller 74a and the second tension roller 74b and the porous imide resin film F conveyed in the extending direction thereof.

[0117] The support arm 74c is provided so as to be able to swing around the support shaft 74d. By swinging the support arm 74c around the support shaft 74d, the intervals between the guide rollers 73d, 73e, 73f and the first tension roller 74a and the second tension roller 74b change, and the tension of the porous imide resin film F changes. The tension of the porous imide resin film F in the tension adjustment unit 74 is adjusted manually. The tension of the porous imide resin film F in the tension adjustment unit 74 may also be adjusted automatically based on the tension of the porous imide resin film F detected by a tension sensor (not shown).

[0118] The winding mechanism 80 includes a driving roller 81, a roller driving unit 82, and a swing mechanism 83. The driving roller 81 is provided on a swing arm 84 of the swing mechanism 83 described later so as to be rotatable around an axis extending in the X-axis direction. The driving roller 81 holds a cylindrical winding core (not shown) around which the porous imide resin film F is wound. The driving roller 81 is driven to rotate around the axis at a predetermined rotation speed by the roller driving unit 82.

[0119] The roller driving unit 82 drives the driving roller 81 to rotate around the axis. The roller driving unit 82 includes a motor 86 and a driving force transmission unit 87. The motor 86 is provided on the base 85. The driving force transmission unit 87 transmits the driving force of the motor 86 to the driving roller 81. In the present embodiment, the driving force transmission unit 87 includes a first transmission member 87a, a second transmission member 87b, and an intermediate transmission member 87c. The first transmission member 87a and the second transmission member 87b are, for example, chains or belts. The intermediate transmission member 87c is, for example, a gear or a pulley. The first transmission member 87a is hung on the output shaft of the motor 86 and the intermediate transmission member 87c. The second transmission member 87b is hung between the intermediate transmission member 87c and the gear or pulley provided on the driving roller 81.

[0120] The roller driving unit 82 operates the motor 86 to drive the output shaft to rotate, and transmits the rotational force to the driving roller 81 via the first transmission member 87a, the intermediate transmission member 87c, and the second transmission member 87b, thereby driving the driving roller 81 to rotate. By driving the driving roller 81 to rotate as described above, the porous imide resin film F is gradually wound onto the winding core held by the driving roller 81. As a result, a finished roll Fm in which the porous imide resin film F is wound is generated.

[0121] The swing mechanism 83 includes a swing arm 84 and an arm driving unit 89. The swing arm 84 supports the driving roller 81. The base end of the swing arm 84 is supported by a support stand 88 provided on the base 71 so as to be rotatable around an axis extending in the X-axis direction. The driving roller 81 is rotatably supported at the front end of the swing arm 84.

[0122] The arm driving unit 89 causes the swing arm 84 to swing around the swing axis 84c. In the present embodiment, the arm driving unit 89 is, for example, a telescopic cylinder. The base end of the telescopic cylinder as the arm driving unit 89 is connected to the base 85 in a manner that allows rotation around an axis extending in the X direction. The other end of the telescopic cylinder is connected to the swing arm 84 in a manner that allows rotation. With respect to the telescopic cylinder as the arm driving unit 89, the control device 90 is used to cause the swing arm 84 to swing in a manner that gradually moves away from the guide roller 73k immediately in front as the outer diameter of the porous imide resin film F wound onto the winding core held by the driving roller 81 increases.

[0123] Figure 7 It is a block diagram showing the functional structure of the control device of the winding device. Figure 7The control device 90 shown controls the operation of each part of the winding device 7. The control device 90 includes a winding control unit 91 and a swing control unit 92 that controls the operation of the swing mechanism 83. The winding control unit 91 controls the operation of the roller driving unit 82 when the driving roller 81 winds up the porous imide resin film F. The swing control unit 92 controls the arm driving unit 89 according to the winding amount of the porous imide resin film F, and swings the swing arm 84.

[0124] The winding control unit 91 controls the roller driving unit 82 so that the driving roller 81 repeatedly performs rotation driving and driving stop at a predetermined timing when the driving roller 81 winds up the porous imide resin film F. The winding control unit 91 controls the roller driving unit 82 so that the driving roller 81 alternately repeats the rotation driving action and the driving stop action. The winding control unit 91 rotates the driving roller 81 intermittently.

[0125] The winding control unit 91 controls the roller driving unit 82 in such a manner that the following actions are repeatedly performed: the action of rotating the driving roller 81 during a preset first setting time; and the action of stopping the driving of the driving roller 81 during a preset second setting time. Here, it is preferred that the second setting time is shorter than the first setting time. The first setting time is 1.5 to 3 seconds, and the second setting time is 0.1 to 0.3 seconds.

[0126] [Method for producing porous imide resin film]

[0127] Next, a method for producing the porous imide-based resin film F using the production system 1 configured as described above will be described. Figure 8 It is a figure which shows an example of the flow of the manufacturing method of the porous imide type resin film F which concerns on embodiment. Fig. 9 and Fig.10 1 is a diagram showing an example of a manufacturing process of a porous imide resin film. The manufacturing method of the porous imide resin film F in this embodiment includes the following steps: a first step S1, forming an unfired film FA; a second step S2, forming a porous imide resin film F; a third step S3, performing a chemical etching process; and a fourth step S4, cutting the porous imide resin film F into a plurality of strips.

[0128] In the first step S1 of forming the unfired film FA, Figure 2In the unfired film forming unit 2 shown in FIG. 1 , a strip-shaped unfired film FA is formed. In the unfired film forming unit 2, first, the substrate supply unit 21 unwinds the substrate S extending in a strip shape. The front end of the unwinded substrate S is fixed to the winding core of the winding roller 25r installed in the substrate winding unit 25 via a plurality of intermediate rollers 28. Then, the winding roller 25r is driven to rotate at a predetermined speed by a motor not shown. Thus, the strip-shaped substrate S is sent out from the substrate supply unit 21 along its extending direction.

[0129] In the coating section 22, a coating liquid containing the resin material A1 and the microparticles A2 is coated on the substrate S supplied from the substrate supply section 21. As a result, Fig. 9 As shown in (A), a strip-shaped unfired film FA containing a resin material A1 and fine particles A2 is formed on a substrate S. The substrate S on which the unfired film FA is formed by the coating unit 22 is sequentially dried under predetermined drying conditions in a drying furnace of a drying unit 23. By passing through the drying furnace of the drying unit 23, the solvent is removed from the unfired film FA on the substrate S.

[0130] In the separation section 24, the substrate S that has passed through the drying section 23 is separated from the unfired film FA. The substrate S separated in the separation section 24 is wound up by the winding roller 25r of the substrate winding section 25. Fig. 9 As shown in (B), the unfired film FA separated from the substrate S in the separation section 24 is wound up by the winding roller 26r of the product winding section 26. As described above, an unfired film roll FAr is generated by winding up the unfired film FA. The generated unfired film roll FAr is taken off from the winding roller 26r and transported to the unwinding section 31 of the sintering and particle removal unit 3.

[0131] In the second step S2 of forming the porous imide resin film F, Figure 3 In the sintering and particle removal unit 3 shown, the unsintered film FA is sintered to remove the particles A2, thereby forming a strip-shaped porous imide resin film F. In the sintering and particle removal unit 3, first, the unwinding section 31 unwinds the unsintered film FA extending in a strip shape from the unsintered film roll FAr. A lead film (not shown) is installed at the front end of the unsintered film FA. Then, the lead film is guided to the winding section 37 through the sintering furnace 33, the first etching section 34, the washing section 35, and the drying section 36. The front end of the lead film is fixed to the winding core of the winding roller 37r installed in the winding section 37. Then, the winding roller 37r is driven to rotate at a predetermined speed by a motor (not shown). Thus, the unsintered film FA is sent out from the winding section 37 along its extension direction.

[0132] In the firing furnace 33, the unfired film FA is fired. Fig. 9As shown in (C), a fired film FB containing microparticles A2 is formed inside the imidized or high-temperature treated resin layer A3. In the first etching portion 34, the fired film FB is etched to remove the microparticles A2 contained in the fired film FB, thereby forming a porous imide resin film F. In the first etching portion 34, the fired film FB is immersed in an etching solution that can dissolve or decompose the microparticles A2, thereby removing the microparticles A2. If the microparticles A2 are removed as described above, pores A4 are formed in the portion where the microparticles A2 exist, as shown in FIG. Fig.10 As shown in (A), a porous imide resin film F is formed.

[0133] In the washing section 35, the porous imide resin film F formed by passing through the first etching section 34 is washed with a washing liquid. The drying section 36 dries the washed porous imide resin film F. The winding section 37 winds up the porous imide resin film F that has passed through the drying section 36 onto a winding core provided on a winding roller 37r. By operating as described above, a porous resin film roll Fr obtained by winding up the porous imide resin film F is generated. The generated porous resin film roll Fr is transported to the etching unit 4.

[0134] In the third step S3 of chemical etching, Figure 4 In the etching unit 4 shown, a chemical etching treatment is performed to dissolve a portion of the porous imide resin film F. First, the unwinding section 41 unwinds the porous imide resin film F extending in a strip from the porous resin film roll Fr. The porous imide resin film F is guided to the winding section 48 through the second etching section 42, the washing section 43, the drying section 44, the re-firing furnace 45, the inspection section 46, and the measuring section 47. The front end of the porous imide resin film F is fixed to the core of the winding roller 48r installed in the winding section 48. Then, the winding roller 48r is driven to rotate at a predetermined speed by a motor not shown. Then, the porous imide resin film F is sent out from the winding roller 48r along its extension direction.

[0135] In the second etching section 42, the porous imide resin film F sent out from the unwinding section 31 is chemically etched. By causing the second etching section 42 to perform chemical etching, Fig.10 As shown in (B), when the microparticles A2 included in the porous imide resin film F are removed by etching in the first etching section 34, burr-like irregularities generated around the pores A4 of the porous imide resin film F due to the escape of the microparticles A2 are flattened.

[0136] In the cleaning section 43, the porous imide resin film F that has passed through the second etching section 42 is cleaned with a cleaning liquid. The drying section 44 dries the cleaned porous imide resin film F. In the re-firing furnace 45, the porous imide resin film F that has passed through the drying section 44 is re-firing. The re-firing furnace 45 heats the porous imide resin film F by a heating section (not shown) while conveying the porous imide resin film F at a predetermined conveying speed in a chamber. In the re-firing furnace 45, the porous imide resin film F is heated to, for example, about 300°C to 400°C.

[0137] In the inspection section 46, the quality of the porous imide resin film F that has passed through the re-firing furnace 45 is inspected. The inspection section 46, for example, performs a foreign matter inspection on the porous imide resin film F. Next, in the measuring section 47, the dimensions of the porous imide resin film F are measured. The measuring section 47, for example, measures the film thickness of the porous imide resin film F. The porous imide resin film F that has passed through the measuring section 47 is wound up onto a winding core provided on a winding roller 48r by the winding section 48. The winding roller 48r is driven to rotate at a predetermined speed set in advance by a motor not shown in the figure. By operating as described above, a finished roll Fm obtained by winding the porous imide resin film F is generated. The generated finished roll Fm is transported to the slitting machine 5.

[0138] In the fourth step S4 of cutting the porous imide resin film F into a plurality of strips, Figure 5 The slitting machine 5 shown cuts the porous imide resin film F into a plurality of strips. First, the unwinding section 51 unwinds the porous imide resin film F extending in a strip shape from the finished roll Fm. The unwinded porous imide resin film F is guided to the cutting section 52. In the cutting section 52, the strip-shaped porous imide resin film F is cut into a plurality of strips along the extending direction of the film. In the cutting section 52, the porous imide resin film F is cut by a disc-shaped cutter 52c while the strip-shaped porous imide resin film F is conveyed along its extending direction.

[0139] The porous imide resin film Fp having a predetermined product width cut out from the cutting section 52 is guided to the product winding section 53. In the product winding section 53, the porous imide resin film Fp is wound on a winding core provided on a winding roller 53r that is driven to rotate at a predetermined rotation speed. In the above-described operation, a product roll Fpr obtained by winding the porous imide resin film Fp is produced.

[0140] In addition, the excess porous imide resin film Fy cut off from the porous imide resin film F before cutting is guided to the excess part winding section 54. The excess porous imide resin film Fy is wound in the excess part winding section 54. In the above operation, the excess roll Fyr obtained by winding the excess porous imide resin film Fy is generated. In the above operation, the product roll Fpr and the excess roll Fyr generated by the slitting machine 5 are unloaded from the slitting machine 5.

[0141] [Film winding method]

[0142] Next, a film winding method implemented when winding at least one of the unfired film FA and the porous imide resin film F in the manufacturing method of the porous imide resin film F as described above is described. The film winding method in this embodiment can be implemented when the porous imide resin film F is wound using the winding device 7 provided in the winding section 48. The film winding method shown below can also be implemented in the same manner when the winding section 37 is equipped with the winding device 7.

[0143] Fig.11 FIG. 4 is a flow chart showing the process of the film winding method. Fig.11 As shown, the film winding method in this embodiment has the following steps: step S11, driving the drive roller 81 to rotate during the first set time; step S12, stopping the drive roller 81 during the second set time; and step S13, determining whether the winding is completed.

[0144] When the winding device 7 is used to rotate a motor (not shown) at a predetermined rotation speed to start winding the porous imide resin film F with the driving roller 81, first in step S11, the driving roller 81 is driven to rotate for a first set time, for example, 1.5 to 3 seconds. Then, when the first set time has passed, in step S12, the driving roller 81 is stopped for a second set time.

[0145] Next, when the second set time has passed, in step S13, it is determined whether the winding in the winding device 7 is completed. As a result, if the winding is not completed, the process returns to step S11 and the same process as the above process is repeated. On the other hand, in step S13, when the winding in the winding device 7 is completed, a series of processes are terminated and the driving roller 81 is stopped.

[0146] As described above, when the driving roller 81 is temporarily stopped in step S12, the tension of the porous imide resin film F is relaxed on the upstream side of the driving roller 81 in the conveying direction of the porous imide resin film F. The plurality of guide rollers 73a to 73k, the first tension roller 74a, and the second tension roller 74b provided on the upstream side of the conveying direction of the porous imide resin film F with respect to the driving roller 81 are all driven rollers. Therefore, even if the driving roller 81 stops, the plurality of guide rollers 73a to 73k, the first tension roller 74a, and the second tension roller 74b each continue to rotate by inertia. With this configuration, the porous imide resin film F is continuously conveyed from the upstream side of the conveying direction of the porous imide resin film F with respect to the driving roller 81. Thus, the tension of the porous imide resin film F is relaxed, and the tension acting locally on the porous imide resin film F can be suppressed. As a result, when the driving roller 81 is subsequently driven to rotate again in step S11 , wrinkles and the like are less likely to be generated in the porous imide-based resin film F.

[0147] As described above, the winding device 7 according to the present embodiment controls the roller driving unit 82 in such a manner that the driving roller 81 repeatedly performs rotational driving and driving stop at a predetermined timing when the driving roller 81 is winding the porous imide resin film F. With this configuration, when the driving roller 81 is stopped, the tension of the porous imide resin film F is relaxed, and when the driving roller 81 is then driven to rotate again in step S11, wrinkles and the like are less likely to be generated in the porous imide resin film F. As a result, the generation of wrinkles and the like during winding can be effectively suppressed.

[0148] In addition, by repeatedly performing the operation of rotating the driving roller 81 during the first set time period set in advance, and the operation of stopping the driving roller 81 during the second set time period set in advance, the driving roller 81 is intermittently stopped during the period of winding the porous imide resin film F. As a result, the generation of wrinkles and the like during winding can be effectively suppressed in the entire porous imide resin film F extending in a strip shape. In addition, since the second set time is shorter than the first set time, the tension of the porous imide resin film F is suppressed from being continuously relaxed for a long time, the increase of the time required for winding can be suppressed, and the generation of wrinkles and the like during winding can be effectively suppressed.

[0149] In addition, as driven rollers for applying a predetermined tension to the porous imide resin film F, a plurality of guide rollers 73a to 73k, a first tension roller 74a, and a second tension roller 74b are provided. When the driving roller 81 stops, the plurality of guide rollers 73a to 73k, the first tension roller 74a, and the second tension roller 74b each continue to rotate by inertia. As a result, the porous imide resin film F is continuously conveyed from the upstream side of the conveying direction of the porous imide resin film F relative to the driving roller 81, and the tension of the porous imide resin film F is relaxed. As a result, the generation of wrinkles and the like during winding can be effectively suppressed.

[0150] The film wound up by the winding device 7 is the porous imide resin film F. By winding up the porous imide resin film F which is prone to wrinkles when wound up in this way by the winding device 7, the occurrence of wrinkles during winding can be effectively suppressed.

[0151] In addition, in the film winding method and the method for producing the porous imide resin film F according to the present embodiment, the driving roller 81 is repeatedly driven to rotate and stopped at a predetermined timing when the porous imide resin film F is wound. As a result, when the driving roller 81 is stopped, the tension of the porous imide resin film F is relaxed, and when the driving roller 81 is driven to rotate again thereafter, wrinkles and the like are less likely to be generated in the porous imide resin film F. As a result, the generation of wrinkles and the like during winding can be effectively suppressed.

[0152] The above describes the implementation mode, but the technical scope of the present invention is not limited to the above-mentioned implementation mode. It is obvious that those skilled in the art can apply various changes or improvements to the above-mentioned implementation mode. In addition, such a method in which changes or improvements are applied is also included in the technical scope of the present invention. In addition, one or more of the elements described in the above-mentioned implementation mode, etc. may sometimes be omitted. In addition, the elements described in the above-mentioned implementation mode, etc. may be appropriately combined. In addition, regarding the execution order of each process shown in the present embodiment, as long as the output of the previous process is not used in the subsequent process, it can be implemented in any order. In addition, regarding the actions in the above-mentioned implementation mode, even if "first", "next", "next" and the like are used for convenience, it is not necessary to implement them in this order.

[0153] For example, in the above-mentioned embodiment, the configuration in which the winding section 48 of the etching unit 4 is provided with the winding device 7 is described as an example, but the present invention is not limited to this configuration. For example, the winding section 37 of the sintering and particle removal unit 3 may be provided with the winding device 7. In this case, the winding device 7 winds up the porous imide resin film F before the chemical etching treatment in the etching unit 4, that is, the intermediate film produced in the process of manufacturing the porous imide resin film F.

[0154] In the above embodiment, the porous imide resin film F is rolled up as an example, but the present invention is not limited to this structure. For example, the film may be made of a material other than the porous imide resin film F.

Claims

1. A winding device for a film extending in a strip shape, the winding device comprising: A driving roller, wherein the driving roller winds up the film; a roller driving unit that drives the driving roller to rotate; and A control device controls the roller driving unit so that the driving roller repeatedly performs rotation driving and stops driving at a predetermined timing when the driving roller winds up the film.

2. The winding device according to claim 1, wherein: The control device controls the roller driving unit in such a manner as to repeatedly perform the following actions: The driving roller is driven to rotate during a first preset time period; and The operation of stopping the driving of the driving roller for a second set time period that is set in advance.

3. The winding device according to claim 2, wherein: The second set time is shorter than the first set time.

4. The winding device according to claim 3, wherein: The first setting time is 1.5 to 3 seconds. The second set time is 0.1 to 0.3 seconds. 5 . The winding device according to claim 1 , further comprising a driven roller for applying a predetermined tension to the film.

6. The winding device according to claim 5, wherein: The specified tension is 4 to 10N.

7. The winding device according to any one of claims 1 to 4, wherein: The film is a porous imide resin film or an intermediate film produced in the process of producing the porous imide resin film.

8. A film winding method, comprising: a method for winding a film extending in a strip shape using a driving roller, the film winding method comprising the step of repeatedly rotating and stopping the driving roller at a predetermined timing when the film is wound.

9. A method for producing a porous imide resin film, comprising the following steps: a first step of coating a coating liquid containing microparticles on a substrate and then drying the coating liquid to form a strip-shaped unfired film; a second step of firing the unfired film and removing the microparticles to form a strip-shaped porous imide resin film; and a third step of performing a chemical etching treatment to dissolve a portion of the porous imide resin film. The production method includes the step of performing the film winding method according to claim 8 when winding at least one of the unfired film and the porous imide resin film.

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