Winding device, film winding method and manufacturing method of porous imide resin film

Abstract

To effectively suppress generation of wrinkles and the like at the time of winding.SOLUTION: A winding device 80 winds a film F extending in a belt-like manner. The winding device 80 includes: a drive roller 81 for winding the film F; a roller drive part 82 for rotationally driving the drive roller 81; and a control device 90 for controlling the roller drive part 82 in such a manner that the drive roller 81 repeats the rotational drive and drive stop at predetermined timing when the drive roller 81 winds the film F.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In order to prevent bending or wrinkling of a long strip-shaped substrate when the substrate is wound up, a configuration has been disclosed that includes a winding roller that winds up the substrate, a tension roller that rotates while applying tension to the substrate and transports the substrate towards the winding roller, and a tension change unit that adjusts the tension of the substrate on the tension roller (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-226510 A Summary of the Invention [Problem to be solved by the invention]

[0004] The contents described in the above-mentioned Patent Document 1 have a problem in that when the object to be wound is a thin film, a soft film, or the like, it is not possible to sufficiently prevent the occurrence of wrinkles, etc., during winding.

[0005] An object of the present invention is to provide a winding device, a film winding method, and a method for producing a porous imide-based resin film that are capable of effectively suppressing the occurrence of wrinkles and the like during winding. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided a winding device for a strip-shaped film, the winding device comprising a drive roller for winding up the film, a roller drive unit for rotating the drive roller, and a control device for controlling the roller drive unit so that the drive roller repeatedly rotates and stops at predetermined timing when the drive roller winds up the film.

[0007] In a second aspect of the present invention, there is provided a method for winding a strip-shaped film using a drive roller, the method including the drive roller repeatedly rotating and stopping at a predetermined timing when winding the film.

[0008] In a third aspect of the present invention, there is provided a method for producing a porous imide-based resin film, comprising a first step of applying a coating liquid containing fine particles onto a substrate and then drying the coating liquid to form a strip-shaped unsintered film, a second step of sintering the unsintered film and then removing the fine particles to form a strip-shaped porous imide-based resin film, and a third step of performing a chemical etching process to dissolve a part of the porous imide-based resin film, the method including carrying out the film winding method according to the second aspect when winding up at least one of the unsintered film and the porous imide-based resin film. Effect of the Invention

[0009] According to the above aspect of the present invention, when the driving roller winds up the film, the driving roller repeatedly rotates and stops at a predetermined timing, and the tension acting on the film during the stoppage is relaxed, so that the tension acting on the film is suppressed from acting locally. As a result, when the driving roller is subsequently rotated, the film is less likely to wrinkle. As a result, the occurrence of wrinkles during winding can be effectively suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a manufacturing system including a winding device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of an unfired film forming unit of the manufacturing system. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of a firing / particle removal unit of the manufacturing system. [Figure 4] FIG. 2 is a diagram showing a schematic configuration of an etching unit of the manufacturing system. [Diagram 5] FIG. 2 is a diagram showing a configuration of a slitter in the manufacturing system. [Figure 6] FIG. 2 is a diagram showing a configuration of a winding device of the manufacturing system. [Figure 7] 4 is a block diagram showing a functional configuration of a control device of the winding device; FIG. [Figure 8] 1 is a flowchart showing an example of a flow of a method for producing a porous imide-based resin film according to an embodiment. [Figure 9] 1A to 1C are diagrams illustrating an example of a process for producing a porous imide-based resin film. [Figure 10] 1A to 1C are diagrams illustrating an example of a process for producing a porous imide-based resin film. [Figure 11] 4 is a flowchart showing an example of the flow of a membrane winding method according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described with reference to the drawings. However, the present invention is not limited to the contents described below. In addition, in the drawings, in order to make each configuration of the embodiment easier to understand, some parts are shown enlarged or emphasized, or some parts are shown simplified, and the actual structure, shape, scale, etc. may differ. Hereinafter, the directions in the drawings will be described using the XYZ coordinate system. In this XYZ coordinate system, a plane parallel to the horizontal plane is the XY plane. One direction parallel to this XY plane is written as the X direction, and a direction perpendicular to the X direction is written as the Y direction. In addition, a direction perpendicular to the XY plane is written as the Z direction. In the following, the X direction, Y direction, and Z direction will be described assuming that the direction indicated by the arrow in the drawing is the + direction, and the direction opposite to the direction indicated by the arrow is the - direction.

[0012] FIG. 1 is a diagram showing an example of a manufacturing system 1 equipped with a winding device 7 according to the present embodiment. FIG. 2 is a diagram showing a schematic configuration of an unfired film forming unit of the manufacturing system. FIG. 3 is a diagram showing a schematic configuration of a firing / particle removal unit of the manufacturing system. FIG. 4 is a diagram showing a schematic configuration of an etching unit of the manufacturing system. FIG. 5 is a diagram showing a configuration of a slitter of the manufacturing system. The manufacturing system 1 shown in FIG. 1 produces a porous imide-based resin film F. The manufacturing system 1 includes an unfired film forming unit 2, a firing / particle removal unit 3, an etching unit 4, a slitter 5, and a system control device (not shown). The manufacturing system 1 produces a porous imide-based resin film F by passing through the unfired film forming unit 2, the firing / particle removal unit 3, the etching unit 4, and the slitter 5 in this order.

[0013] The unsintered film forming unit 2 shown in Figures 1 and 2 applies a coating liquid containing fine particles onto a substrate S, and then dries the coating liquid to form a strip-shaped unsintered film FA. The firing / particle removal unit 3 shown in Figures 1 and 3 fires the unsintered film FA to remove the fine particles, thereby forming a strip-shaped porous imide-based resin film F. The etching unit 4 shown in Figures 1 and 4 performs a chemical etching process to dissolve a portion of the porous imide-based resin film F. The slitter 5 shown in Figures 1 and 5 cuts the porous imide-based resin film F into strips of a specified product width. The system control device provides overall control of the entire manufacturing system 1.

[0014] In this embodiment, the unfired film forming unit 2, the firing / particle removal unit 3, the etching unit 4, and the slitter 5 are arranged spaced apart from one another. In such a manufacturing system 1, intermediate products being manufactured are wound in a roll shape and transported between the processes between the unfired film forming unit 2 and the firing / particle removal unit 3, between the firing / particle removal unit 3 and the etching unit 4, and between the etching unit 4 and the slitter 5, as will be described in detail later. Note that among the unfired film forming unit 2, the firing / particle removal unit 3, and the etching unit 4, units whose processes are performed before and after each other may be provided consecutively.

[0015] [Coating solution] Before describing each component of the manufacturing system 1, the porous imide-based resin film F manufactured by the manufacturing system 1 will be described. The coating liquid that is the raw material of the porous imide-based resin film F contains a predetermined resin material, fine particles, and a solvent. Examples of the predetermined resin material include polyamic acid, polyimide, polyamideimide, and polyamide. As the solvent, an organic solvent capable of dissolving these resin materials is used.

[0016] The coating liquid is prepared, for example, by mixing a solvent in which fine particles have been previously dispersed with polyamic acid, polyimide, polyamideimide, or polyamide in an arbitrary ratio. Alternatively, the coating liquid may be prepared by polymerizing polyamic acid, polyimide, polyamideimide, or polyamide in a solvent in which fine particles have been previously dispersed. For example, the coating liquid can be produced by polymerizing tetracarboxylic dianhydride and diamine in an organic solvent in which fine particles have been previously dispersed to form polyamic acid, or further imidizing to form polyimide.

[0017] 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. If the viscosity of the coating liquid is within this range, a uniform film can be formed.

[0018] In the coating liquid, when the fine particles and the polyamic acid or polyimide are dried to form an unsintered film FA, if the material of the fine particles is an inorganic material described below, the fine particles and the polyamic acid or polyimide are mixed so that the ratio of the fine particles to the polyimide is 1 to 4 (mass ratio). It is more preferable to set it to 1.2 to 3 (mass ratio). If the material of the fine particles is an organic material described below, the fine particles and the polyamic acid or polyimide are mixed so that the ratio of the fine particles to the polyimide is 0.5 to 2 (mass ratio). It is more preferable to set it to 0.6 to 1.5 (mass ratio). In addition, the fine particles and the polyamic acid or polyimide are mixed so that the volume ratio of the fine particles to the polyimide is 0.6 to 2.7 when the unsintered film FA is formed. It is more preferable to set it to 0.8 to 2 (volume ratio). If the mass ratio or volume ratio of the fine particles / polyimide in the unsintered film FA is equal to or higher than the lower limit, a pore density suitable for a separator can be obtained, and if it is equal to or lower than the upper limit, a stable film can be formed without problems such as an increase in viscosity or cracks in the film. The mass ratio is the same as above when the resin material is polyamideimide or polyamide instead of polyamic acid or polyimide.

[0019] Each resin material will be specifically described below. <Polyamic acid> The polyamic acid used in the present embodiment is not particularly limited, and may be any one obtained by polymerizing any tetracarboxylic dianhydride and diamine. The amount of tetracarboxylic dianhydride and diamine used is not particularly limited, but it is preferable to use 0.50 to 1.50 mol of diamine per 1 mol of tetracarboxylic dianhydride, more preferably 0.60 to 1.30 mol, and particularly preferably 0.70 to 1.20 mol.

[0020] The tetracarboxylic dianhydride can be appropriately selected from tetracarboxylic dianhydrides that have been used as a synthetic raw material for polyamic acid. The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride, but it is preferable to use an aromatic tetracarboxylic dianhydride from the viewpoint of the heat resistance of the resulting polyimide resin. Two or more kinds of tetracarboxylic dianhydrides may be used in combination.

[0021] Specific examples of suitable aromatic tetracarboxylic dianhydrides 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, carboxylic acid 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'-benzophenone tetracarboxylate carboxylic 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-(m-phenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid Examples of the aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and 1,2,3,4-cyclohexane tetracarboxylic dianhydride.Among these, 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferred in terms of cost, availability, etc. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

[0022] The diamine can be appropriately selected from diamines that have been used as a synthetic raw material for polyamic acid. The diamine may be an aromatic diamine or an aliphatic diamine, but from the viewpoint of the heat resistance of the resulting polyimide resin, an aromatic diamine is preferred. These diamines may be used in combination of two or more kinds.

[0023] Examples of aromatic diamines include diamino compounds having one or about 2 to 10 phenyl groups bonded thereto, specifically phenylenediamine and its derivatives, diaminobiphenyl compounds and their derivatives, diaminodiphenyl compounds and their derivatives, diaminotriphenyl compounds and their derivatives, diaminonaphthalene and its derivatives, aminophenylaminoindan and its derivatives, diaminotetraphenyl compounds and their derivatives, diaminohexaphenyl compounds and their derivatives, and cardo-type fluorenediamine derivatives.

[0024] The phenylenediamines include m-phenylenediamine, p-phenylenediamine, etc., and the phenylenediamine derivatives include diamines to which alkyl groups such as methyl groups and ethyl groups are bonded, such as 2,4-diaminotoluene and 2,4-triphenylenediamine.

[0025] Diaminobiphenyl compounds are compounds in which two aminophenyl groups are bonded together via the phenyl groups, such as 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

[0026] Diaminodiphenyl compounds are compounds in which two aminophenyl groups are bonded to each other via another group. The bond can be an ether bond, a sulfonyl bond, a thioether bond, a bond by an alkylene or its derivative group, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, a ureylene bond, or the like. The alkylene bond has about 1 to 6 carbon atoms, and the derivative group has one or more hydrogen atoms of the alkylene group substituted with a halogen atom or the like.

[0027] 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'-diaminodiphenyl methane, 3,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl methane, 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) p-aminophenyl)-2-pentene, iminodianiline, 4-methyl-2,4-bis(p-aminophenyl)pentane, bis(p-aminophenyl)phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 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, and the like.

[0028] Among these, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4'-diaminodiphenyl ether are preferred in view of cost, availability, and the like.

[0029] The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are bonded via other groups, and the other groups are selected from the same groups as those of 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.

[0030] Examples of diaminonaphthalenes include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

[0031] Examples of aminophenylaminoindanes include 5 or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindan.

[0032] Examples of diaminotetraphenyl compounds 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.

[0033] Examples of the cardo-type fluorenediamine derivatives include 9,9-bisanilinefluorene.

[0034] The aliphatic diamine may preferably have, for example, about 2 to 15 carbon atoms, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

[0035] The diamine may be a compound in which a hydrogen atom of the diamine 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, and the like.

[0036] There is no particular limitation on the means for producing the polyamic acid used in the present embodiment, and for example, a known method such as a method of reacting an acid and a diamine component in an organic solvent can be used.

[0037] The reaction between tetracarboxylic dianhydride and diamine is usually carried out in an organic solvent. The organic solvent used in the reaction between 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 kinds.

[0038] Examples of organic solvents used in the reaction between 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 can be used alone or in combination of two or more. There is no particular restriction on the amount of organic solvent used, but it is preferable that the content of the produced polyamic acid is 5 to 50 mass %.

[0039] 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 from the viewpoint of the solubility of the produced polyamic acid.

[0040] The polymerization temperature is generally -10 to 120°C, preferably 5 to 30°C. The polymerization time varies depending on the raw material composition used, but is usually 3 to 24 hours. The intrinsic viscosity of the organic solvent solution of polyamic acid obtained under such conditions is preferably in the range of 1,000 to 100,000 cP (centipoise), more preferably 5,000 to 70,000 cP.

[0041] <Polyimide> The polyimide used in this embodiment is not limited in structure or molecular weight, and any known soluble polyimide can be used as long as it is soluble in the organic solvent used in the coating solution. The polyimide may have a condensable functional group such as a carboxyl group or a functional group that promotes a crosslinking reaction or the like during baking in the side chain.

[0042] In order to make the polyimide soluble in an organic solvent, it is effective to use a monomer for introducing a flexible, bent structure into the main chain, for example, an aliphatic diamine such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, or 4,4'-diaminodicyclohexylmethane; an aromatic diamine such as 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, or 4,4'-diaminobenzanilide; a polyoxyalkylene diamine such as polyoxyethylenediamine, polyoxypropylenediamine, or polyoxybutylenediamine; a polysiloxane diamine; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, or 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride; or the like. It is also effective to use a monomer having a functional group that improves the solubility in an organic solvent, for example, a fluorinated diamine such as 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl or 2-trifluoromethyl-1,4-phenylenediamine. Furthermore, in addition to the monomer for improving the solubility of the polyimide, the same monomer as that described in the polyamic acid column above can be used in combination, as long as the solubility is not impaired.

[0043] There is no particular limitation on the means for producing the polyimide soluble in an organic solvent used in this embodiment, and for example, a known method such as chemically imidizing or thermally imidizing a polyamic acid and dissolving it in an organic solvent can be used. Examples of such polyimides include aliphatic polyimides (all aliphatic polyimides) and aromatic polyimides, and aromatic polyimides are preferred.

[0044] <Polyamide-imide> The polyamideimide used in this embodiment is not limited in structure or molecular weight, and any known soluble polyamideimide can be used as long as it is soluble in the organic solvent used in the coating liquid. The polyamideimide may have a condensable functional group such as a carboxyl group or a functional group that promotes a crosslinking reaction or the like during baking in the side chain.

[0045] The polyamideimide used in the present embodiment is not particularly limited and may be one obtained by reacting any trimellitic anhydride with a diisocyanate, or one obtained by imidizing a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride with a diamine.

[0046] Examples of the optional trimellitic anhydride or reactive derivative thereof include trimellitic anhydride, trimellitic anhydride halides such as trimellitic anhydride chloride, and trimellitic anhydride esters.

[0047] Examples of diisocyanates include metaphenylene diisocyanate, p-phenylene diisocyanate, 4,4'-oxybis(phenylisocyanate), 4,4'-diisocyanatediphenylmethane, bis[4-(4-isocyanatephenoxy)phenyl]sulfone, and 2,2'-bis[4-(4-isocyanatephenoxy)phenyl]propane.

[0048] The diamine may be the same as those exemplified in the description of the polyamic acid.

[0049] <Polyamide> As the polyamide, polyamides obtained from dicarboxylic acids and diamines are preferred, and aromatic polyamides are particularly preferred.

[0050] Dicarboxylic acids 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 diphenic acid.

[0051] The diamine may be the same as those exemplified in the description of the polyamic acid.

[0052] <Fine particles> Next, the fine particles will be described. For example, fine particles having a high sphericity and a small particle size distribution index are used. Such fine particles have excellent dispersibility in liquid and do not aggregate with each other. The particle size (average diameter) of the fine particles can be set to, for example, about 5 to 3000 nm. By using such fine particles, the pore size of the porous imide-based resin film F obtained by removing the fine particles in a later process can be made uniform. Therefore, the electric field applied to the separator formed by the porous imide-based resin film F can be made uniform.

[0053] The material of the fine particles is not particularly limited, and any known material can be used as long as it is insoluble in the solvent contained in the coating liquid and can be removed from the porous imide-based resin film F in a later process. For example, inorganic materials include metal oxides such as silica (silicon dioxide), titanium oxide, and alumina (Al2O3). Organic materials include organic polymer fine particles such as high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene, epoxy resins, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polymethyl methacrylate, and polyether. Examples of fine particles include colloidal silica such as (monodisperse) spherical silica particles, calcium carbonate, and the like. In this case, the pore size of the porous imide-based resin film F can be made more uniform.

[0054] The coating liquid may contain various additives such as a release agent, a dispersant, a condensation agent, an imidizing agent, a surfactant, etc., in addition to the predetermined resin material, fine particles, and a solvent, as necessary.

[0055] [Unbaked film forming unit] As shown in FIG. 2, the unsintered film forming unit 2 is provided with a substrate supply section 21, a coating section 22, a drying section 23, a separation section 24, a substrate winding section 25, and a product winding section 26 on a floor surface 8. The substrate supply section 21 unwinds the substrate S extending in a strip shape. Here, the material of the substrate S may be, for example, polyethylene terephthalate (PET), but is not limited to this configuration and may be a metal material such as stainless steel. The substrate S is set on a supply roller 21r in the state of a substrate roll Sr wound in a roll shape. The substrate supply section 21 unwinds the substrate S from the substrate roll Sr.

[0056] The substrate S is unwound from the substrate roll Sr by being wound up by, for example, a winding roller 25r provided in a substrate winding section 25 described later. The substrate S is fed at a predetermined feed speed to the coating section 22, the drying section 23, and the substrate winding section 25 via a plurality of intermediate rollers. The coating section 22 applies a coating liquid containing fine particles onto the substrate S supplied from the substrate supply section 21. The coating section 22 forms a band-shaped unfired film FA on the substrate S by ejecting a coating liquid prepared in advance, for example, from a nozzle, onto the substrate S fed at a predetermined speed. Here, the configuration for applying the coating liquid onto the substrate S in the coating section 22 is not limited in any way, and various known configurations can be adopted.

[0057] The substrate S on which the unsintered film FA is formed in the coating section 22 is supplied to the drying section 23. The drying section 23 removes the solvent contained in the unsintered film FA. The drying section 23 may be configured to sequentially pass the unsintered film FA through a plurality of drying furnaces having different heating temperatures. By passing through the drying section 23, the solvent is removed from the unsintered film FA on the substrate S. The substrate S and the unsintered film FA that have passed through the drying section 23 are sent to the separation section 24. The separation section 24 separates the substrate S from the unsintered film FA. The substrate S separated in the separation section 24 is sent to the substrate winding section 25. The unsintered film FA separated from the substrate S in the separation section 24 is sent to the product winding section 26.

[0058] The substrate winding section 25 winds the substrate S around a core set on a winding roller 25r. The winding roller 25r is driven to rotate at a preset predetermined number of rotations by a motor (not shown). The product winding section 26 winds the unsintered film FA separated from the substrate S around a core set on a winding roller 26r. The winding roller 26r is driven to rotate at a preset predetermined number of rotations by a motor (not shown). In this manner, an unsintered film roll FAr around which the unsintered film FA is wound is generated. The generated unsintered film roll FAr is transported to the firing / fine particle removal unit 3, for example, by manual work using an operator or a transport cart, a manipulator, an overhead crane, or the like.

[0059] [Baking / particle removal unit] As shown in FIG. 3, the firing / particle removal unit 3 is provided on the floor surface 8 with an unwinding section 31, a firing furnace 33, a first etching section 34, a cleaning section 35, a drying section 36, and a winding section 37. The unwinding section 31 unwinds the unsintered film FA extending in a strip shape from the unsintered film roll FAr. The unsintered film roll FAr on which the unsintered film FA is wound in a roll shape is set on an unsintered film roll FAr. The unsintered film FA is unwound from the unsintered film roll FAr by being wound up, for example, by a winding roller 37r provided in a winding section 37 described later.

[0060] The unsintered film FA is sent at a predetermined feeding speed through the firing furnace 33, the first etching section 34, the cleaning section 35, and the drying section 36 to the winding section 37. In this embodiment, the unsintered film FA is sent at a predetermined feeding speed by, for example, a conveyor (not shown) provided in the first etching section 34 described later in addition to the winding roller 37r.

[0061] The baking furnace 33 bakes the unbaked film FA to imidize the resin material in the coating liquid, and forms a baked film FB containing fine particles. The baking furnace 33 heats the unbaked film FA, for example, in a chamber, to about 120°C to 450°C with an infrared heater or the like while feeding the film FA at a predetermined feed rate. The first etching unit 34 etches the baked film FB to remove the fine particles contained in the baked film FB, and forms a porous imide-based resin film F. The first etching unit 34 removes the fine particles by, for example, immersing the baked film FB in an etching solution capable of dissolving or decomposing the fine particles. For example, a hydrofluoric acid solution is used as the etching solution. The first etching unit 34 immerses the baked film FB in an etching tank (not shown) in which the etching solution is stored, while feeding the baked film FB at a predetermined feed rate. As a result, the fine particles contained in the baked film FB are dissolved and removed.

[0062] When the fine particles are removed in this manner, cavities are formed in the areas where the fine particles were present, forming a porous imide-based resin film F. In addition, in the first etching section 34, for example, a conveyor that supports and transports the fired film FB from below may be provided.

[0063] The cleaning section 35 cleans the porous imide-based resin film F formed through the first etching section 34 with a cleaning liquid. The method used for cleaning the porous imide-based resin film F in the cleaning section 35 is not limited to this configuration. The drying section 36 dries the cleaned porous imide-based resin film F by various known methods. The drying section 36 volatilizes the cleaning liquid remaining in the porous imide-based resin film F by, for example, heating the porous imide-based resin film F that has passed through the cleaning section 35. Here, at least one of the cleaning section 35 and the drying section 36 may be provided with a conveyor that supports and transports the porous imide-based resin film F from below.

[0064] The winding section 37 winds the porous imide-based resin film F on a core set in the winding roller 37r. The winding roller 37r is driven to rotate at a preset predetermined number of revolutions by a motor (not shown). In this manner, a porous resin film roll Fr is produced on which the porous imide-based resin film F is wound. The produced porous resin film roll Fr is transported to the etching unit 4, for example, by manual work using an operator or a transport cart, a manipulator, an overhead crane, or the like.

[0065] [Etching unit 4] As shown in FIG. 4, the etching unit 4 includes an unwinding section 41, a second etching section 42, a cleaning section 43, a drying section 44, a re-baking furnace 45, an inspection section 46, a measurement section 47, and a winding section 48 on the floor surface 8. The unwinding section 41 unwinds the porous imide-based resin film F extending in a strip shape from the porous resin film roll Fr. The porous resin film roll Fr on which the porous imide-based resin film F is wound in a roll shape is set on the unwinding roller 41r of the unwinding section 41. The unwinding section 41 unwinds the porous imide-based resin film F from the porous resin film roll Fr. The porous imide-based resin film F is unwound from the porous resin film roll Fr by being wound, for example, by a winding roller 48r provided in the winding section 48 described later.

[0066] The unwound porous imide-based resin film F is fed at a predetermined speed through a second etching section 42, a cleaning section 43, a drying section 44, a re-baking furnace 45, an inspection section 46, and a measurement section 47 to a winding section 48. In this embodiment, the porous imide-based resin film F is fed at a predetermined speed by a winding roller 48r.

[0067] The second etching unit 42 performs chemical etching on the porous imide-based resin film F. When the fine particles contained in the porous imide-based resin film F are removed by the etching process in the first etching unit 34, the fine particles are released, forming minute burr-like irregularities protruding from the periphery of the holes on the surface of the porous imide-based resin film F. The second etching unit 42 performs chemical etching to smooth out the irregularities on the periphery of the holes.

[0068] The etching solution used in the chemical etching in the second etching unit 42 is, for example, a sodium hydroxide solution or a TMAH (tetramethylammonium hydroxide) solution. The second etching unit 42 immerses the porous imide-based resin film F in an etching tank (not shown) in which an etching solution is stored, while feeding the porous imide-based resin film F at a predetermined feed speed. As a result, the irregularities around the holes formed in the porous imide-based resin film F are dissolved or softened, and the surface of the porous imide-based resin film F is smoothed. Note that the second etching unit 42 may be provided with a conveyor that supports and transports the porous imide-based resin film F from below.

[0069] The cleaning unit 43 cleans the porous imide-based resin film F that has passed through the second etching unit 42 with a cleaning liquid. The method used for cleaning the porous imide-based resin film F in the cleaning unit 43 is not limited to this configuration. The drying unit 44 dries the cleaned porous imide-based resin film F by various known methods. The drying unit 44 volatilizes the cleaning liquid remaining in the porous imide-based resin film F by, for example, heating the porous imide-based resin film F that has passed through the cleaning unit 43. At least one of the cleaning unit 43 and the drying unit 44 may be provided with a conveyor that supports and transports the porous imide-based resin film F from below.

[0070] The re-baking furnace 45 re-baks the porous imide-based resin film F. The re-baking furnace 45 imidizes the resin components and the like remaining in the porous imide-based resin film F that were not imidized in the above-mentioned baking furnace 33. The re-baking furnace 45 heats the porous imide-based resin film F, for example, to about 300°C to 400°C, for example, with an infrared heater or the like within a chamber while feeding the porous imide-based resin film F at a predetermined feed rate.

[0071] The inspection unit 46 inspects the quality of the porous imide-based resin film F that has been through the re-firing furnace 45. The inspection unit 46, for example, inspects the porous imide-based resin film F for foreign matter. The inspection unit 46 may inspect, for example, the occurrence of pinholes in the porous imide-based resin film F. For example, the inspection unit 46 photographs the porous imide-based resin film F with a camera (not shown) while irradiating the porous imide-based resin film F with light from a lighting device (not shown). The inspection unit 46 performs image analysis on the photographed image (video) and determines whether the occurrence of foreign matter and pinholes falls within the inspection criteria. The inspection contents and inspection methods in the inspection unit 46 are not limited in any way.

[0072] The measuring unit 47 measures the dimensions of the porous imide-based resin film F. For example, the measuring unit 47 measures the film thickness of the porous imide-based resin film F. The measuring unit 47 may measure other dimensions, such as the width of the porous imide-based resin film F. The measuring unit 47 determines whether the measured dimensions of the porous imide-based resin film F are within the dimensional standards. There are no limitations on the measurement content or measurement method in the measuring unit 47. Furthermore, there are no particular limitations on the inspection by the inspection unit 46, the results of the measurement by the measuring unit 47, the inspection standards, and how to handle the results if they are outside the measurement standards.

[0073] The winding section 48 winds the porous imide-based resin film F around a core set in the winding roller 48r. The winding roller 48r is driven to rotate at a preset rotation speed by a motor (not shown). In this manner, a finished roll Fm is produced in which the porous imide-based resin film F is wound. The produced finished roll Fm is transported to the slitter 5, for example, by manual work using an operator or a transport cart, a manipulator, an overhead crane, or the like.

[0074] [Slitter] 5, the slitter 5 cuts the strip-shaped porous imide-based resin film F that has passed through the etching unit 4 to a predetermined width. The slitter 5 includes an unwinding section 51, a cutting section 52, a product winding section 53, and a surplus winding section 54. An unwinding roller 51r of the unwinding section 51 unwinds the strip-shaped porous imide-based resin film F from the finished product roll Fm.

[0075] The cutting unit 52 cuts the strip-shaped porous imide-based resin film F into multiple strips in the stretching direction (longitudinal direction) of the film. The cutting unit 52 divides the strip-shaped porous imide-based resin film F into multiple pieces in the width direction. The cutting unit 52 cuts the porous imide-based resin film F with a disk-shaped cutter 52c, for example, while feeding the strip-shaped porous imide-based resin film F in the stretching direction of the strip-shaped porous imide-based resin film F.

[0076] At this time, the porous imide-based resin film F is cut out from the widthwise middle part of the porous imide-based resin film F formed with a predetermined width in accordance with the product width. The porous imide-based resin film Fp having the predetermined product width cut out from the widthwise middle part of the porous imide-based resin film F may be one strip or two or more strips. In addition, both ends in the widthwise direction of the porous imide-based resin film F are not used as a product and are cut off from the porous imide-based resin film Fp as surplus porous imide-based resin film Fy.

[0077] The product winding section 53 winds up the porous imide-based resin film Fp having a predetermined product width cut out from the cutting section 52. In this embodiment, for example, two strips of porous imide-based resin film Fp are cut out from the porous imide-based resin film F before cutting. For this reason, two product winding sections 53 are provided. The product winding section 53 winds up the porous imide-based resin film Fp on a core set in a winding roller 53r. The winding roller 53r is driven to rotate at a predetermined rotation speed set in advance by a motor (not shown). In this manner, a product roll Fpr in which the porous imide-based resin film Fp is wound is produced.

[0078] The surplus winding section 54 winds up the surplus porous imide-based resin film Fy cut off from the porous imide-based resin film F before cutting. The surplus winding section 54 winds up the surplus porous imide-based resin film Fy on a core set in the winding roller 54r. The winding roller 54r is driven to rotate at a preset predetermined number of rotations by a motor (not shown). In this way, a surplus roll Fyr around which the surplus porous imide-based resin film Fy is wound is generated. The product roll Fpr and the surplus roll Fyr generated by the slitter 5 in this way are carried out from the slitter 5 by, for example, manual work using an operator or a transport cart, a manipulator, an overhead crane, or the like.

[0079] [Winding device] 6, the winding device 7 is used, for example, in the winding section 48 of the etching unit 4. The winding device 7 may also be used in the winding section 37 of the firing / 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.

[0080] The base 71 is provided on the floor surface 8. The introduction section 72, the multiple guide rollers 73, the tension adjustment section 74, and the winding mechanism 80 are provided on the base 71. The introduction section 72 introduces the porous imide-based resin film F into the winding device 7 from the upstream side in the feed direction of the porous imide-based resin film F (film). The introduction section 72 has a pair of upper and lower introduction rollers 72a, 72b. The porous imide-based resin film F is introduced by being sandwiched between the pair of introduction rollers 72a, 72b.

[0081] The multiple guide rollers 73 guide the porous imide-based resin film F introduced from the introduction section 72 to the winding mechanism 80 via the tension adjustment section 74. In this embodiment, guide rollers 73a to 73k are provided as the multiple guide rollers 73. Each of the guide rollers 73a to 73k is provided on a support member (not shown) provided on the base 71 so as to be rotatable around an axis extending in the X direction.

[0082] The outer peripheral surface of each of the guide rollers 73a to 73k comes into contact with the porous imide-based resin film F being taken up by a drive roller 81 of a take-up mechanism 80 described below. Each of the guide rollers 73a to 73k is a driven roller that is driven by frictional force generated between itself and the porous imide-based resin film F fed in the stretching direction. The guide rollers (driven rollers) 73a to 73k apply a predetermined tension to the porous imide-based resin film F.

[0083] The guide roller 73a is provided at a distance in the +Y direction from the pair of introduction rollers 72a, 72b. The guide roller 73a guides the porous imide-based resin film F sent out from the introduction section 72 in the +Y direction toward the guide roller 73b provided at a distance diagonally downward. The guide roller 73b guides the porous imide-based resin film F toward the guide roller 73c provided at a distance in the -Z direction. The guide roller 73c guides the porous imide-based resin film F toward the guide roller 73d provided at a distance in the +Y direction.

[0084] The guide roller 73d guides the porous imide-based resin film F toward the first tension roller 74a provided at an interval in the -Y direction and the +Z direction. The first tension roller 74a guides the porous imide-based resin film F toward the guide roller 73e provided at an interval in the +Y direction and the +Z direction. The guide roller 73e guides the porous imide-based resin film F toward the second tension roller 74b provided at an interval in the -Y direction and the +Z direction. The second tension roller 74b guides the porous imide-based resin film F toward the guide roller 73f provided at an interval in the +Y direction and the +Z direction. The guide roller 73f guides the porous imide-based resin film F toward the guide roller 73g provided at an interval in the -Y direction and the +Z direction.

[0085] The guide roller 73g guides the porous imide-based resin film F toward the guide roller 73h provided at a distance in the +Y direction. The guide roller 73i is provided facing the upper side of the guide roller 73h. The porous imide-based resin film F passes between the guide rollers 73h and 73i and is guided toward the guide roller 73j provided at a distance in the -Z direction. The guide roller 73j guides the porous imide-based resin film F toward the guide roller 73k provided at a distance in the +Y direction. The guide roller 73k guides the porous imide-based resin film F toward the drive roller 81 provided at a distance in both the +Y direction and the +Z direction.

[0086] The tension adjustment unit 74 adjusts the tension introduced to the porous imide-based resin film F fed toward the winding mechanism 80. In this embodiment, it is preferable that the tension adjustment unit 74 adjusts the tension so that a tension of, for example, 4 to 10 N is introduced to the porous imide-based resin film F. The tension adjustment unit 74 includes a first tension roller 74a, a second tension roller 74b, and a support arm 74c.

[0087] The first tension roller 74a and the second tension roller 74b are provided on a support arm 74c so as to be rotatable about an axis extending in the X-direction. The outer peripheral surfaces of the first tension roller 74a and the second tension roller 74b are in contact with the porous imide-based resin film F. Each of the first tension roller 74a and the second tension roller 74b is a driven roller that is driven by the frictional force generated between itself and the porous imide-based resin film F fed in the stretching direction.

[0088] The support arm 74c is provided so as to be able to swing about the support shaft 74d. By swinging the support arm 74c about the support shaft 74d, the distance between the guide rollers 73d, 73e, 73f and the first tension roller 74a and the second tension roller 74b changes, and the tension of the porous imide-based resin film F changes. The tension of the porous imide-based resin film F is adjusted manually in the tension adjustment unit 74. The tension of the porous imide-based resin film F may be adjusted automatically in the tension adjustment unit 74 based on the tension of the porous imide-based resin film F detected by a tension sensor (not shown).

[0089] The winding mechanism 80 includes a drive roller 81, a roller drive unit 82, and a swing mechanism 83. The drive roller 81 is provided on a swing arm 84 of the swing mechanism 83 (described later) so as to be rotatable about an axis extending in the X-axis direction. The drive roller 81 holds a cylindrical core (not shown) around which the porous imide-based resin film F is wound. The drive roller 81 is driven to rotate about the axis at a predetermined rotation speed by the roller drive unit 82.

[0090] The roller driving unit 82 drives the driving roller 81 to rotate around its axis. The roller driving unit 82 includes a motor 86 and a driving force transmission unit 87. The motor 86 is provided on a base 85. The driving force transmission unit 87 transmits the driving force of the motor 86 to the driving roller 81. In this 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, a chain or a belt. The intermediate transmission member 87c is, for example, a gear or a pulley. The first transmission member 87a is wound around the output shaft of the motor 86 and the intermediate transmission member 87c. The second transmission member 87b is wound around the intermediate transmission member 87c and a gear or a pulley provided on the driving roller 81.

[0091] The roller driving unit 82 operates the motor 86 to rotate the output shaft, 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 rotating the driving roller 81. By driving the driving roller 81 to rotate in this manner, the porous imide-based resin film F is wound up on the core held by the driving roller 81. As a result, a finished roll Fm with the porous imide-based resin film F wound around it is produced.

[0092] The swing mechanism 83 includes a swing arm 84 and an arm drive unit 89. The swing arm 84 supports a drive roller 81. A base end of the swing arm 84 is supported by a support stand 88 provided on the base 71 so as to be movable around an axis extending in the X-axis direction. The drive roller 81 is rotatably supported at a tip end of the swing arm 84.

[0093] The arm driver 89 swings the swing arm 84 around the swing shaft 84c. In this embodiment, the arm driver 89 is, for example, a telescopic cylinder. A base end of the telescopic cylinder serving as the arm driver 89 is rotatably connected to the base 85 around an axis extending in the X direction. The other end of the telescopic cylinder is rotatably connected to the swing arm 84. The telescopic cylinder serving as the arm driver 89 swings the swing arm 84 by the control device 90 so as to gradually move away from the immediately preceding guide roller 73k as the outer diameter of the porous imide-based resin film F wound around the core held by the drive roller 81 increases.

[0094] Fig. 7 is a block diagram showing the functional configuration of a control device of the winding device. The control device 90 shown in Fig. 7 controls the operation of each part of the winding device 7. The control device 90 includes a winding control part 91 and a swing control part 92 that controls the operation of the swing mechanism 83. The winding control part 91 controls the operation of the roller driving part 82 when the drive roller 81 winds up the porous imide-based resin film F. The swing control part 92 controls the arm driving part 89 in accordance with the winding amount of the porous imide-based resin film F, and swings the swing arm 84.

[0095] The winding control unit 91 controls the roller driving unit 82 so that the driving roller 81 repeats rotational driving and driving stop at a predetermined timing when the driving roller 81 winds up the porous imide-based resin film F. The winding control unit 91 controls the roller driving unit 82 so that the driving roller 81 alternately repeats a rotational driving operation and a driving stop operation. The winding control unit 91 rotates the driving roller 81 intermittently.

[0096] The winding control unit 91 controls the roller driving unit 82 to rotate the driving roller 81 for a first preset time and stop driving the driving roller 81 for a second preset time. Here, the second preset time is preferably shorter than the first preset time. The first preset time is 1.5 to 3 seconds, and the second preset time is 0.1 to 0.3 seconds.

[0097] [Method for producing porous imide-based resin film] Next, a method for producing a porous imide-based resin film F using the production system 1 configured as described above will be described. Fig. 8 is a diagram showing an example of the flow of a method for producing a porous imide-based resin film F according to an embodiment. Figs. 9 and 10 are diagrams showing an example of a manufacturing process of a porous imide-based resin film. The method for producing a porous imide-based resin film F in this embodiment includes a first step S1 of forming an unbaked film FA, a second step S2 of forming a porous imide-based resin film F, a third step S3 of performing a chemical etching process, and a fourth step S4 of cutting the porous imide-based resin film F into a plurality of strips.

[0098] In the first step S1 of forming the unsintered film FA, a strip-shaped unsintered film FA is formed in the unsintered film forming unit 2 shown in FIG. 2. In the unsintered film forming unit 2, first, the substrate supply unit 21 unrolls the substrate S extending in a strip shape. The leading end of the unsintered substrate S is fixed to a core attached to the winding roller 25r of the substrate winding unit 25 via a plurality of intermediate rollers 28. Next, the winding roller 25r is rotated at a predetermined number of revolutions by a motor (not shown). Then, the substrate supply unit 21 sends out the strip-shaped substrate S in its stretching direction.

[0099] In the coating unit 22, a coating liquid containing a resin material A1 and fine particles A2 is applied onto the substrate S supplied from the substrate supply unit 21. As a result, as shown in FIG. 9(A), a strip-shaped unfired film FA containing the resin material A1 and fine particles A2 is formed on the substrate S. The substrate S on which the unfired film FA has been formed in the coating unit 22 is sequentially dried under predetermined drying conditions in a drying furnace of the 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.

[0100] In the separation section 24, the substrate S that has passed through the drying section 23 is separated from the unsintered film FA. The substrate S separated in the separation section 24 is taken up by the take-up roller 25r of the substrate take-up section 25. As shown in FIG. 9(B) , the unsintered film FA separated from the substrate S in the separation section 24 is taken up by the take-up roller 26r of the product take-up section 26. In this manner, an unsintered film roll FAr around which the unsintered film FA is wound is produced. The produced unsintered film roll FAr is removed from the take-up roller 26r and transported to the unwinding section 31 of the firing / particle removal unit 3.

[0101] In the second step S2 of forming the porous imide-based resin film F, the unsintered film FA is sintered in the sintering / particle removing unit 3 shown in FIG. 3 to remove the particles A2, thereby forming a strip-shaped porous imide-based resin film F. In the sintering / particle removing 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 attached to the tip 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 cleaning section 35, and the drying section 36. The tip of the lead film is fixed to a core attached to the winding roller 37r of the winding section 37. Then, the winding roller 37r is rotated at a predetermined number of revolutions by a motor (not shown). Then, the unsintered film FA is sent out from the winding section 37 in its stretching direction.

[0102] In the firing furnace 33, the unfired film FA is fired to form a fired film FB containing fine particles A2 inside the imidized or high-temperature treated resin layer A3, as shown in FIG. 9(C). In the first etching section 34, the fired film FB is etched to remove the fine particles A2 contained in the fired film FB, forming a porous imide-based resin film F. In the first etching section 34, the fine particles A2 are removed, for example, by immersing the fired film FB in an etching solution capable of dissolving or decomposing the fine particles A2. When the fine particles A2 are removed in this manner, holes A4 are formed in the portions where the fine particles A2 were present, and a porous imide-based resin film F is formed, as shown in FIG. 10(A).

[0103] In the cleaning section 35, the porous imide-based resin film F formed through the first etching section 34 is cleaned with a cleaning liquid. In the drying section 36, the porous imide-based resin film F after cleaning is dried. In the winding section 37, the porous imide-based resin film F that has passed through the drying section 36 is wound around a core set in a winding roller 37r. In this manner, a porous resin film roll Fr is produced around which the porous imide-based resin film F is wound. The produced porous resin film roll Fr is transported to the etching unit 4.

[0104] In the third step S3 of the chemical etching process, the etching unit 4 shown in FIG. 4 performs a chemical etching process to dissolve a part of the porous imide-based resin film F. First, the unwinding section 41 unwinds the porous imide-based resin film F extending in a strip shape from the porous resin film roll Fr. The porous imide-based resin film F is guided to the winding section 48 through the second etching section 42, the cleaning section 43, the drying section 44, the re-baking furnace 45, the inspection section 46, and the measurement section 47. The tip of the porous imide-based resin film F is fixed to a core attached to the winding roller 48r of the winding section 48. Then, the winding roller 48r is rotated at a predetermined number of revolutions by a motor (not shown). Then, the porous imide-based resin film F is sent out from the winding roller 48r in its stretching direction.

[0105] In the second etching section 42, chemical etching is performed on the porous imide-based resin film F sent out from the unwinding section 31. By performing chemical etching, the second etching section 42 smoothes out burr-like irregularities that are generated around the periphery of the hole A4 of the porous imide-based resin film F due to the escape of the fine particles A2 when the fine particles A2 contained in the porous imide-based resin film F are removed by the etching process in the first etching section 34, as shown in FIG.

[0106] In the cleaning section 43, the porous imide-based resin film F that has passed through the second etching section 42 is cleaned with a cleaning solution. In the drying section 44, the porous imide-based resin film F after cleaning is dried. In the re-baking furnace 45, the porous imide-based resin film F that has passed through the drying section 44 is re-baked. In the re-baking furnace 45, the porous imide-based resin film F is heated in a heating section (not shown) while being fed at a predetermined feed rate within a chamber. In the re-baking furnace 45, the porous imide-based resin film F is heated to, for example, about 300°C to 400°C.

[0107] In the inspection section 46, the quality of the porous imide-based resin film F that has passed through the re-firing furnace 45 is inspected. The inspection section 46, for example, inspects the porous imide-based resin film F for foreign matter. Next, in the measurement section 47, the dimensions of the porous imide-based resin film F are measured. The measurement section 47 measures, for example, the film thickness of the porous imide-based resin film F. The porous imide-based resin film F that has passed through the measurement section 47 is wound around a core set on a winding roller 48r in the winding section 48. The winding roller 48r is driven to rotate at a predetermined number of rotations set in advance by a motor (not shown). In this way, a finished product roll Fm in which the porous imide-based resin film F is wound is produced. The produced finished product roll Fm is transported to the slitter 5.

[0108] In the fourth step S4 of cutting the porous imide-based resin film F into multiple strips, the porous imide-based resin film F is cut into multiple strips by a slitter 5 shown in FIG. 5. First, the unwinding section 51 unwinds the porous imide-based resin film F extending in a strip shape from the finished roll Fm. The unwound porous imide-based resin film F is guided to the cutting section 52. In the cutting section 52, the strip-shaped porous imide-based resin film F is cut into multiple strips in the stretching direction of the film. In the cutting section 52, the porous imide-based resin film F is cut by a disk-shaped cutter 52c while feeding the strip-shaped porous imide-based resin film F in its stretching direction.

[0109] The porous imide-based 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-based resin film Fp is wound around a core set on a winding roller 53r that is driven to rotate at a predetermined rotation speed. In this manner, a product roll Fpr in which the porous imide-based resin film Fp is wound is produced.

[0110] Furthermore, the surplus porous imide-based resin film Fy separated from the uncut porous imide-based resin film F is guided to the surplus portion winding section 54. The surplus porous imide-based resin film Fy is wound up in the surplus portion winding section 54. In this manner, a surplus roll Fyr around which the surplus porous imide-based resin film Fy is wound is produced. The product roll Fpr and surplus roll Fyr produced in this manner by the slitter 5 are conveyed out of the slitter 5.

[0111] [Membrane winding method] Next, a film winding method performed when winding up at least one of the unsintered film FA and the porous imide-based resin film F in the manufacturing method of the porous imide-based resin film F as described above will be described. The film winding method in this embodiment is performed when winding up the porous imide-based resin film F with the winding device 7 provided in the winding section 48. The film winding method described below is also performed in the case where the winding device 7 is provided in the winding section 37.

[0112] Fig. 11 is a flow chart showing the flow of the membrane winding method. As shown in Fig. 11, the membrane winding method in this embodiment includes step S11 for rotating the driving roller 81 for a first set time, step S12 for stopping the driving of the driving roller 81 for a second set time, and step S13 for determining whether the winding is completed.

[0113] In the winding device 7, a motor (not shown) is driven to rotate at a predetermined rotation speed to start winding up the porous imide-based resin film F by the drive roller 81. First, in step S11, the drive roller 81 is driven to rotate for a first preset time, for example, 1.5 to 3 seconds. Next, after the first preset time has elapsed, in step S12, the drive roller 81 is stopped from being driven for a second preset time.

[0114] Next, when the second set time has elapsed, in step S13, it is determined whether or not winding in the winding device 7 has been completed. If the result is that winding has not been completed, the process returns to step S11, and the same process as above is repeated. On the other hand, if winding in the winding device 7 has been completed in step S13, the series of processes is terminated, and the drive roller 81 is stopped.

[0115] In this way, when the driving roller 81 is temporarily stopped in step S12, the tension of the porous imide-based resin film F is relaxed on the upstream side of the driving roller 81 in the feeding direction of the porous imide-based resin film F. The guide rollers 73a to 73k, the first tension roller 74a, and the second tension roller 74b provided on the upstream side of the driving roller 81 in the feeding direction of the porous imide-based resin film F are all driven rollers. Therefore, even if the driving roller 81 stops, each of the guide rollers 73a to 73k, the first tension roller 74a, and the second tension roller 74b continues to rotate by inertia. With this configuration, the porous imide-based resin film F continues to be fed from the upstream side of the feeding direction of the porous imide-based resin film F without stopping relative to the driving roller 81. Then, the tension of the porous imide-based resin film F is relaxed, and the tension acting locally on the porous imide-based resin film F is suppressed. As a result, when the driving roller 81 is rotated again in step S11, wrinkles and the like are less likely to occur in the porous imide-based resin film F.

[0116] As described above, the winding device 7 according to this embodiment controls the roller driving unit 82 so that the driving roller 81 repeatedly rotates and stops at a predetermined timing when the driving roller 81 winds up the porous imide-based resin film F. With this configuration, when the driving roller 81 is stopped, the tension of the porous imide-based resin film F is relaxed, and when the driving roller 81 is then rotated again in step S11, wrinkles and the like are less likely to occur in the porous imide-based resin film F. As a result, it is possible to effectively suppress the occurrence of wrinkles and the like during winding.

[0117] Moreover, by repeatedly driving the drive roller 81 to rotate for a preset first set time and stopping the drive roller 81 for a preset second set time, the drive roller 81 is stopped intermittently while the porous imide-based resin film F is being wound up. As a result, it is possible to effectively prevent wrinkles and the like from occurring during winding in the entire porous imide-based resin film F that extends in a strip shape. Furthermore, since the second set time is shorter than the first set time, it is possible to effectively prevent wrinkles and the like from occurring during winding while preventing the tension of the porous imide-based resin film F from continuing to slacken for a long period of time and preventing the time required for winding from becoming too long.

[0118] In addition, the porous imide-based resin film F is provided with a plurality of guide rollers 73a-73k, a first tension roller 74a, and a second tension roller 74b as driven rollers that apply a predetermined tension to the porous imide-based resin film F. When the driving roller 81 stops, each of the plurality of guide rollers 73a-73k, the first tension roller 74a, and the second tension roller 74b continues to rotate due to inertia. As a result, the porous imide-based resin film F continues to be fed from the upstream side of the feeding direction of the porous imide-based resin film F relative to the driving roller 81 without stopping, and the tension of the porous imide-based resin film F is relaxed. As a result, it is possible to effectively prevent wrinkles and the like from occurring during winding.

[0119] The film taken up by the winding device 7 is a porous imide-based resin film F. By taking up the porous imide-based resin film F, which is prone to wrinkles during winding, by the winding device 7, it is possible to effectively prevent wrinkles and the like from occurring during winding.

[0120] In addition, in the film winding method and the manufacturing method of the porous imide-based resin film F according to the present embodiment, the drive roller 81 repeatedly rotates and stops at a predetermined timing when winding up the porous imide-based resin film F. As a result, when the drive roller 81 is stopped, the tension of the porous imide-based resin film F is relaxed, and when the drive roller 81 is rotated again thereafter, wrinkles and the like are less likely to occur in the porous imide-based resin film F. As a result, it is possible to effectively suppress the occurrence of wrinkles and the like during winding.

[0121] Although the embodiments have been described above, the technical scope of the present invention is not limited to the above-mentioned embodiments. It is clear to those skilled in the art that various modifications or improvements can be made to the above-mentioned embodiments. Furthermore, forms with such modifications or improvements are also included in the technical scope of the present invention. Furthermore, one or more of the requirements described in the above-mentioned embodiments may be omitted. Furthermore, the requirements described in the above-mentioned embodiments may be combined as appropriate. Furthermore, the execution order of each process shown in this embodiment can be realized in any order, as long as the output of the previous process is not used in the subsequent process. Furthermore, even if the operations in the above-mentioned embodiments are described using "first," "next," "followed," etc. for convenience, it is not essential to carry out the operations in this order.

[0122] For example, in the above embodiment, the winding device 7 is provided in the winding section 48 of the etching unit 4, but the present invention is not limited to this configuration. For example, the winding device 7 may be provided in the winding section 37 of the firing / particle removal unit 3. In this case, the winding device 7 winds up the porous imide-based resin film F before the chemical etching process in the etching unit 4, that is, an intermediate film produced in the process of manufacturing the porous imide-based resin film F.

[0123] In the above embodiment, the porous imide-based resin film F is wound up, but the present invention is not limited to this configuration. For example, the film may be made of a material other than the porous imide-based resin film F. [Explanation of symbols]

[0124] 7... Winding device, 81... Drive roller, 82... Roller drive section, 90... Control device, F... Porous imide resin film, FA... Unbaked film, S... Base material, S1... First process, S2... Second process, S3... Third process

Claims

1. A winding device for a strip-shaped film, comprising: a drive roller for winding up the film; A roller drive unit that drives and rotates the drive roller; a control device that controls the roller drive unit so that the drive roller repeats rotational driving and stopping at a predetermined timing when the drive roller winds up the film. Winding device.

2. The control device includes: Driving the drive roller to rotate for a first preset time period; stopping the driving roller for a second preset time period; and controlling the roller driving unit so as to repeat the above steps.

2. The winding device according to claim 1.

3. The second set time is shorter than the first set time.

3. The winding device according to claim 2.

4. The first set time is 1.5 to 3 seconds, The second set time is 0.1 to 0.3 seconds.

4. The winding device according to claim 3.

5. a driven roller for applying a predetermined tension to the film; A winding device according to any one of claims 1 to 4.

6. The predetermined tension is 4 to 10 N.

6. The winding device according to claim 5.

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

8. A method for winding a strip-shaped film by a driving roller, comprising the steps of: The driving roller repeats rotational driving and stopping at a predetermined timing when winding up the film. Membrane winding method.

9. A method for producing a porous imide-based resin film, comprising: a first step of applying a coating liquid containing fine particles onto a substrate and then drying the coating liquid to form a strip-shaped unfired film; a second step of firing the unfired film and then removing the fine particles to form a strip-shaped porous imide-based resin film; and a third step of performing a chemical etching process to dissolve a part of the porous imide-based resin film, The method includes performing the film winding method according to claim 8 when winding at least one of the unsintered film and the porous imide-based resin film. A method for producing a porous imide-based resin film.

Images