Slitter and manufacturing system for porous imide-system resin film

Abstract

To suppress wrinkles from occurring on a film when feeding the film in an extending direction of the film, so as to suppress the wrinkles from having a bad effect on a production quality of the film.SOLUTION: A slitter 5 comprises: a cutting part 52 that cuts a porous imide-system resin film F extending in a band shape into a plurality of films in an extending direction of the porous imide-system resin film F; winding rollers 53r that wind up at least one of the plurality of porous imide-system resin films F cut by the cutting part 52; and a plurality of first guide rollers 56a and 56b, supported rotatably around a shaft line, which guide the porous imide-system resin films F toward the winding roller 53r. At least either of intervals D3 between outer peripheral surfaces of the porous imide-system resin films F wound up by the winding roller 53r and outer peripheral surfaces of the first guide rollers 56b arranged adjacent to the winding rollers 53r and intervals D4 between outer peripheral surfaces of the adjacently arranged two first guide rollers 56a and 56b are in a range of 1 mm-20 mm.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a slitter and a system for producing a porous imide-based resin film. [Background technology]

[0002] A manufacturing system for manufacturing a membrane extending in a strip shape has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6539655 Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacturing system of Patent Document 1, the manufactured membrane may be wound into a roll. The manufactured membrane may also be cut into multiple strips in the stretching direction (longitudinal direction) of the membrane. In such a case, wrinkles may occur in the membrane when the membrane is fed from the upstream side in the feeding direction to the membrane winding section or cutting section, which may adversely affect the manufacturing quality of the membrane.

[0005] The present invention aims to provide a slitter and a manufacturing system for a porous imide-based resin membrane that can prevent wrinkles from occurring in the membrane when the membrane is fed in the stretching direction of the membrane and prevent adverse effects on the production quality of the membrane. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided a slitter comprising: a cutting section that cuts a strip-like membrane into multiple strips in the stretching direction of the membrane; a winding roller that winds up at least one of the multiple strips of membrane cut by the cutting section; and a plurality of first guide rollers that are supported rotatably about an axis and guide the membrane toward the winding roller, wherein at least one of the distance between the outer circumferential surface of the membrane wound up by the winding roller and the outer circumferential surface of the first guide roller adjacent to the winding roller, and the distance between the outer circumferential surfaces of two adjacent first guide rollers, is within the range of 1 mm to 20 mm.

[0007] In a second aspect of the present invention, there is provided a slitter comprising: a cutting section that cuts a strip-like extending film into multiple strips in the extension direction of the film; a winding roller that winds up at least one of the multiple strips of film cut by the cutting section; and a plurality of second guide rollers that are supported rotatably about an axis and guide the film toward the cutting section, wherein the cutting section includes a lower blade roller whose outer circumferential surface is in contact with the film, and an upper blade roller that is arranged radially outward of the lower blade roller, and the film is cut into multiple strips by sandwiching it between the lower blade roller and the upper blade roller, and at least one of the distance between the outer circumferential surface of the lower blade roller and the outer circumferential surface of the second guide roller adjacent to the lower blade roller and the distance between the outer circumferential surfaces of two adjacent second guide rollers is within a range of 1 mm to 20 mm.

[0008] In a third aspect of the present invention, there is provided a system for producing a porous imide-based resin film, the system including: a first system for 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 system for sintering the unsintered film formed in the first system and then removing the fine particles to form a strip-shaped porous imide-based resin film; a third system for performing a chemical etching process to dissolve a portion of the porous imide-based resin film formed in the second system; and a slitter according to the first or second aspect, which cuts at least one of the porous imide-based resin films formed in the second and third systems into a plurality of strips. Effect of the Invention

[0009] According to the above aspect of the present invention, by setting at least one of the distance between the outer circumferential surface of the membrane wound by the winding roller and the outer circumferential surface of the first guide roller adjacent to the winding roller and the distance between the outer circumferential surfaces of the two adjacent first guide rollers to within a range of 1 mm to 20 mm, it is possible to suppress the occurrence of wrinkles in the membrane when the membrane is fed in the stretching direction of the membrane, and to suppress adverse effects on the production quality of the membrane. The same effect is also obtained when the cut membrane is fed to the winding roller. Furthermore, by setting at least one of the distance between the outer circumferential surface of the lower blade roller in the cutting section and the outer circumferential surface of the second guide roller adjacent to the lower blade roller and the distance between the outer circumferential surfaces of the two adjacent second guide rollers to within a range of 1 mm to 20 mm, it is possible to suppress the occurrence of wrinkles in the membrane when the membrane is fed to the cutting section, and to suppress adverse effects on the production quality of the membrane. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of a system for producing a porous imide-based resin film 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 side view showing the configuration of a cutting section of the slitter. [Figure 7] FIG. 6 is an enlarged view showing a part of the slitter shown in FIG. 5. [Figure 8] FIG. 2 is a block diagram showing a functional configuration of a control device of the slitter. [Figure 9] 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 10] 1A to 1C are diagrams illustrating an example of a process for producing a porous imide-based resin film. [Figure 11]1A to 1C are diagrams illustrating an example of a process for producing a porous imide-based resin film. 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 porous imide-based resin film manufacturing system 1 according to the present embodiment. FIG. 2 is a diagram showing a schematic configuration of an unbaked film forming unit of the manufacturing system. FIG. 3 is a diagram showing a schematic configuration of a baking / 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 manufactures a porous imide-based resin film (membrane) F. The manufacturing system 1 includes an unfired film forming unit (first system) 2, a firing / particle removal unit (second system) 3, an etching unit (third system) 4, a slitter 5, and a system control device (not shown). The manufacturing system 1 produces a porous imide-based resin film F by sequentially 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 production system 1, the porous imide-based resin film F produced by the production system 1 will be described. The coating liquid, which 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 greater than the lower limit, a pore density suitable for a separator can be obtained, and if it is equal to or less 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 liquid. 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 to a specific structure or molecular weight, and any known soluble polyamideimide can be used as long as it is soluble in an organic solvent used in the coating solution. 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 material 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 / 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, for example, with an infrared heater while feeding the unbaked film FA at a predetermined feed rate. The first etching unit 34 performs etching on the baked film FB, removes 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 an 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 the above-mentioned method. The drying section 36 dries the cleaned porous imide-based resin film F. 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 around a core set in the winding roller 37r. The winding roller 37r is driven to rotate at a preset rotation speed 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 a worker 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, while feeding the porous imide-based resin film F at a predetermined feed speed, for example, within a chamber.

[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. Note that the inspection contents and inspection methods in the inspection unit 46 are not limited to those described above.

[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. The measurement contents and measurement methods in the measuring unit 47 are also not limited to those described above. In addition, the inspection by the inspection unit 46, the results of the measurement by the measuring unit 47, the inspection standards, and handling in the case where the results are outside the measurement standards are not particularly limited.

[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 a worker or a transport cart, a manipulator, an overhead crane, or the like.

[0074] [Slitter] As shown in FIG. 5, the slitter 5 cuts the strip-shaped porous imide-based resin film F that has passed through the etching unit 4 into multiple strips in the stretching direction (longitudinal direction) of the porous imide-based resin film F. The slitter 5 cuts the porous imide-based resin film F into multiple strips of porous imide-based resin film F having a predetermined width in the X direction. The slitter 5 mainly includes an unwinding section 51, a cutting section 52, a winding section 53, a surplus portion winding section 54, a first guide roller group 56, and a second guide roller group 57. The unwinding section 51, the cutting section 52, the winding section 53, the surplus portion winding section 54, the first guide roller group 56, and the second guide roller group 57 are supported by a base 55 provided on a floor surface 8 via a frame (not shown).

[0075] The unwinding section 51 unwinds the porous imide-based resin film F extending in a band shape from the finished product roll Fm. The unwinding section 51 includes an unwinding roller 51r. The finished product roll Fm transported from the etching unit 4 is supported on the unwinding roller 51r. The unwinding roller 51r is rotatably mounted on a frame around an axis extending in the X-axis direction. Here, the unwinding roller 51r may be rotatably mounted without including the unwinding roller drive section 51d, but in this embodiment, the unwinding section 51 includes an unwinding roller drive section 51d including a motor that rotates and drives the unwinding roller 51r.

[0076] Fig. 6 is a side view showing the configuration of the cutting section of the slitter. As shown in Figs. 5 and 6, the cutting section 52 cuts the strip-shaped porous imide-based resin film F into a plurality of strips in the stretching direction of the film. The cutting section 52 divides the strip-shaped porous imide-based resin film F into a plurality of strips in the width direction of the porous imide-based resin film along the X direction. The cutting section 52 cuts the strip-shaped porous imide-based resin film F 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, for example. The cutting section 52 includes a lower blade roller 52b and an upper blade roller 52c.

[0077] The lower blade roller 52b is provided on a frame (not shown) so as to be rotatable around an axis extending in the X-axis direction. The lower blade roller 52b has a roll width equal to or greater than the width of the porous imide-based resin film F before cutting, which is fed from the unwinding section 51. The outer peripheral surface of the lower blade roller 52b contacts the porous imide-based resin film F from below. As shown in FIG. 6, a plurality of grooves 52m are formed on the outer peripheral surface of the lower blade roller 52b at predetermined positions in the X-direction. In this embodiment, for example, three grooves 52m are formed. The plurality of grooves 52m are formed at a plurality of positions in the X-direction along the outer peripheral surface of the lower blade roller 52b over the entire circumference in the circumferential direction. The positions of the plurality of grooves 52m in the X-direction are set according to the positions where the porous imide-based resin film F is to be cut.

[0078] The upper blade roller 52c is disposed radially outward of the lower blade roller 52b. In this embodiment, the upper blade roller 52c is provided on the upper side (+Z side) of the lower blade roller 52b. A plurality of upper blade rollers 52c are provided at intervals in the X direction. The upper blade rollers 52c are provided in the same number as the plurality of grooves 52m of the lower blade roller 52b. Each upper blade roller 52c is disk-shaped and provided rotatably around an axis extending in the X-axis direction. A sharp blade portion 52s is formed continuously on the outer periphery of each upper blade roller 52c all around the circumference. The blade portion 52s of each upper blade roller 52c is inserted into the groove 52m of the lower blade roller 52b.

[0079] As shown in Fig. 5, the upper blade rollers 52c are supported at the tip of a swing arm 52p so as to be rotatable about an axis extending in the X direction. The base end of the swing arm 52p is connected to a swing shaft 52y which is rotationally driven by a motor (not shown). The swing arm 52p is configured to be swingable about the base end by rotating the swing shaft 52y by the motor. With this configuration, the upper blade rollers 52c supported at the tip of the swing arm 52p can advance and retreat relative to the lower blade roller 52b.

[0080] In the cutting section 52, the porous imide-based resin film F sent from the unwinding section 51 through a second guide roller group 57 described below passes between the lower blade roller 52b and the multiple upper blade rollers 52c. While being sent at a predetermined feed speed in the extension direction of the porous imide-based resin film F, the porous imide-based resin film F is sandwiched between each of the blade portions 52s of the multiple upper blade rollers 52c and each of the grooves 52m of the lower blade roller 52b, so that the porous imide-based resin film F is continuously cut in the extension direction of the porous imide-based resin film F. As a result, the porous imide-based resin film F is cut into multiple strips in the extension direction.

[0081] 6, in this embodiment, the upper blade roller 52c has an upper blade roller 52c1 disposed at the center in the width direction of the porous imide-based resin film F, and a pair of upper blade rollers 52c2 and 52c3 spaced apart on both widthwise outer sides of the upper blade roller 52c1. The upper blade rollers 52c2 and 52c3 are disposed on the inner side in the width direction of the porous imide-based resin film F than both widthwise ends Fe of the porous imide-based resin film F.

[0082] By cutting the porous imide-based resin film F into a plurality of strips with the upper blade rollers 52c1, 52c2, and 52c3, the porous imide-based resin film Fp1 and the porous imide-based resin film Fp2 having a predetermined product width are cut out between the upper blade roller 52c1 and one of the upper blade rollers 52c2, and between the upper blade roller 52c1 and the other upper blade roller 52c3. Here, two strips of the porous imide-based resin film Fp1 and Fp2 are obtained as the porous imide-based resin film Fp having the predetermined product width, but the porous imide-based resin film Fp having the predetermined product width cut out by the cutting unit 52 may be only one strip or two or more strips. In addition, the outer portion of the porous imide-based resin film F for one upper blade roller 52c2 and the outer portion of the porous imide-based resin film F for the other upper blade roller 52c3 are not used as products, but are separated from the porous imide-based resin films Fp1 and Fp2 as surplus porous imide-based resin film Fy.

[0083] As shown in Fig. 5, the 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 Fp1 and Fp2 are cut out from the porous imide-based resin film F before cutting. For this reason, the winding section 53 includes two sets of a first winding section 53A and a second winding section 53B. Each of the winding sections 53 (53A, 53B) winds up at least one of the multiple strips of porous imide-based resin film Fp cut in the cutting section.

[0084] Each winding section 53 includes a winding roller 53r, a winding roller drive section 53d, a nip roller 53n, a guide rail 53g, and a slide member 53s. The winding roller 53r is provided rotatably around an axis extending in the X-axis direction. A core (not shown) for winding the porous imide-based resin film Fp (Fp1, Fp2) is set on the winding roller 53r. The winding roller drive section 53d includes a motor (not shown) and drives the winding roller 53r to rotate at a predetermined number of revolutions. As a result, the porous imide-based resin film Fp is wound around the core set on the winding roller 53r. In this manner, a product roll Fpr is produced around which the porous imide-based resin film Fp is wound.

[0085] The nip roller 53n is provided on the +Y direction side with respect to the winding roller 53r. The nip roller 53n is provided rotatably around an axis extending in the X-axis direction. The nip roller 53n contacts the porous imide-based resin film Fp taken up by the winding roller 53r. The nip roller 53n presses the porous imide-based resin film Fp taken up by the winding roller 53r toward the winding roller 53r. The nip roller 53n is configured so that the force pressing the porous imide-based resin film Fp can be adjusted by various known mechanisms such as a cylinder (not shown).

[0086] The guide rail 53g allows the winding roller 53r to advance and retreat relative to the first guide rollers 56a and 56b described later. The guide rail 53g extends in the Y direction. The slide member 53s is configured to be able to advance and retreat in the Y direction along the guide rail 53g. The winding roller drive unit 53d and the winding roller 53r are provided on the slide member 53s. With this configuration, the winding roller 53r can advance and retreat in the Y direction along the guide rail 53g together with the slide member 53s and the winding roller drive unit 53d. The slide member 53s is controlled by a control device 90 described later so as to gradually move away from the first guide rollers 56a and 56b as the amount of porous imide-based resin film Fp wound around the core set on the winding roller 53r increases. As a result, the position at which the porous imide-based resin film Fp is sent from the first guide rollers 56a, 56b to the winding section 53 starts to be wound around the winding roller 53r is kept constant.

[0087] 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 on the winding roller 54r. In this embodiment, the surplus porous imide-based resin film Fy is cut out from both sides in the width direction of the porous imide-based resin film Fp when the porous imide-based resin film Fp is cut in the cutting section 52. Therefore, the surplus winding section 54 sets two cores on the winding roller 54r and winds up the two strips of surplus porous imide-based resin film Fy cut out from both sides in the width direction of the porous imide-based resin film F. Two sets of winding rollers 54r may also be provided.

[0088] The winding roller 54r is driven to rotate at a preset predetermined number of revolutions by a motor (not shown). In this manner, a surplus roll Fyr is produced in which the surplus porous imide-based resin film Fy is wound. The product roll Fpr and the surplus roll Fyr produced by the slitter 5 in this manner are carried out from the slitter 5, for example, by manual work using a worker or a transport cart, a manipulator, an overhead crane, or the like.

[0089] 7 is an enlarged view of a part of the slitter shown in FIG. 5. As shown in FIG. 7, the second guide roller group 57 guides the porous imide-based resin film F before cutting toward the lower blade roller 52b of the cutting section 52. In this embodiment, the second guide roller group 57 includes, for example, two second guide rollers 57a and 57b. The number of second guide rollers 57a and 57b constituting the second guide roller group 57 is not limited to two, and may be one, or three or more. The porous imide-based resin film F unwound from the unwinding section 51 is fed to the second guide roller group 57 via intermediate rollers 58a, 58b, and 58c.

[0090] The intermediate roller 58a guides the porous imide-based resin film F unwound from the unwind roller 51r toward the intermediate roller 58b arranged at an interval in the -Y direction and the -Z direction. The intermediate roller 58b guides the porous imide-based resin film F toward the intermediate roller 58c arranged at an interval in the -Y direction and the +Z direction. The intermediate roller 58c guides the porous imide-based resin film F to the second guide roller 57a arranged at an interval in the -Y direction and the +Z direction. The second guide roller 57a guides the porous imide-based resin film F to the second guide roller 57b arranged at an interval in the -Y direction. The second guide roller 57b guides the porous imide-based resin film F toward the lower blade roller 52b arranged at an interval in the -Y direction and the +Z direction.

[0091] Here, at least one of the distance D1 between the outer peripheral surface of the lower blade roller 52b and the outer peripheral surface of the second guide roller 57b adjacent to the lower blade roller 52b and the distance D2 between the outer peripheral surfaces of the two adjacent second guide rollers 57a, 57b is set within a range of 1 mm to 20 mm. In this embodiment, the distance D2 between the outer peripheral surfaces of the two second guide rollers 57a, 57b is set within a range of 1 mm to 20 mm. The distance D1 between the outer peripheral surface of the lower blade roller 52b and the outer peripheral surface of the second guide roller 57b adjacent to the lower blade roller 52b may be set within a range of 1 mm to 20 mm. A more preferable range for the distances D1 and D2 is 1 mm to 10 mm. A particularly preferable range for the distances D1 and D2 is 2 mm to 5 mm. Such a preferable range leads to suppression of wrinkles in the porous imide-based resin film F before entering the lower blade roller 52b. Furthermore, the dimensional precision of the width of the porous imide-based resin film F can be improved.

[0092] The first guide roller group 56 guides the porous imide-based resin film Fp (Fp1, Fp2) cut in the cutting section 52 toward the winding roller 53r. The first guide roller group 56 includes two groups, a first guide roller group 56A and a first guide roller group 56B, for guiding the porous imide-based resin film Fp to each of the winding roller 53r of the first winding section 53A and the winding roller 53r of the second winding section 53B.

[0093] In this embodiment, each of the first guide roller groups 56 (56A, 56B) includes, for example, first guide rollers 56a, 56b. The number of first guide rollers 56a, 56b constituting the first guide roller group 56 is not limited to two, and may be one, or three or more. The porous imide-based resin films Fp1, Fp2 cut by the cutting unit 52 are fed to the first guide roller group 56 via a separation roller 59.

[0094] The separation roller 59 separates the porous imide-based resin film Fp cut into multiple strips by the cutting section 52 into a porous imide-based resin film Fp1, a porous imide-based resin film Fp2, and two excess strips of porous imide-based resin film Fy. The porous imide-based resin film Fp1 separated by the separation roller 59 is guided to a first guide roller 56a of a first guide roller group 56A arranged at an interval in the -Y direction and the +Z direction with respect to the separation roller 59. The first guide roller 56a of the first guide roller group 56A guides the porous imide-based resin film Fp1 to a first guide roller 56b arranged at an interval in the -Y direction and the +Z direction. The first guide roller 56b guides the porous imide-based resin film Fp1 to the first winding section 53A. The first guide roller 56b guides the porous imide-based resin film Fp1 between the winding roller 53r of the first winding section 53A and the nip roller 53n.

[0095] The porous imide-based resin film Fp2 separated by the separation roller 59 is guided to the first guide roller 56a of the first guide roller group 56B, which is arranged at a distance from the separation roller 59 in the -Y direction and the -Z direction. The first guide roller 56b guides the porous imide-based resin film Fp2 to the second winding section 53B. The first guide roller 56a of the first guide roller group 56B guides the porous imide-based resin film Fp2 to the first guide roller 56b, which is arranged at a distance from the separation roller 59 in the -Y direction and the -Z direction. The first guide roller 56b guides the porous imide-based resin film Fp2 between the winding roller 53r and the nip roller 53n of the first winding section 53A.

[0096] Here, at least one of the distance D3 between the outer peripheral surface of the porous imide-based resin film Fp taken up by the winding roller 53r and the outer peripheral surface of the first guide roller 56b adjacent to the winding roller 53r, and the distance D4 between the outer peripheral surfaces of the two adjacent first guide rollers 56a, 56b is set within a range of 1 mm to 20 mm. In this embodiment, the distance D3 between the outer peripheral surface of the porous imide-based resin film Fp taken up by the winding roller 53r and the outer peripheral surface of the first guide roller 56b adjacent to the winding roller 53r, and the distance D4 between the outer peripheral surfaces of the two adjacent first guide rollers 56a, 56b are each set within a range of 1 mm to 20 mm. A more preferable range for the distances D3 and D4 is 1 mm to 10 mm. A particularly preferable range for the distances D3 and D4 is 2 mm to 5 mm. Within such a preferable range, wrinkles can be suppressed when the porous imide-based resin film Fp is wound around the winding roller 53r.

[0097] 5, the excess porous imide-based resin film Fy separated by the separation roller 59 is guided to the winding roller 54r of the excess winding section 54 via a plurality of intermediate rollers 58e, 58f, 58g, and 58h arranged at intervals in the -Y and -Z directions with respect to the separation roller 59. Each of the first guide rollers 56a, 56b, the second guide rollers 57a, 57b, the intermediate rollers 58a to 58h, and the separation roller 59 is provided rotatably about an axis extending in the X-axis direction.

[0098] In this embodiment, the slitter 5 further includes a tension sensor 80. The tension sensor 80 measures the tension of the porous imide-based resin film F fed from the unwinding roller 51r to the take-up roller 53r. The tension sensor 80 detects, for example, the tension acting on the intermediate roller 58b by the porous imide-based resin film F. An output (detection value) of the tension detected by the tension sensor 80 is output to the control device 90.

[0099] Fig. 8 is a block diagram showing the functional configuration of the control device of the slitter. The control device 90 shown in Fig. 8 controls the operation of each part of the slitter 5. The control device 90 includes a tension acquisition unit 91 and a winding control unit 92. The tension acquisition unit 91 acquires the detection result of the tension of the porous imide-based resin film F from the unwinding roller 51r to the winding roller 53r as an output from the tension sensor 80.

[0100] The winding control unit 92 controls the operation of the winding roller drive unit 53d and the unwinding roller drive unit 51d. The winding control unit 92 controls the operation of the winding roller drive unit 53d and the unwinding roller drive unit 51d so that the porous imide-based resin film F is fed at a predetermined feed speed. In this embodiment, the control device 90 adjusts the tension applied to the porous imide-based resin film F from the unwinding roller 51r to the winding roller 53r by controlling the rotational drive of the winding roller 53r by the winding roller drive unit 53d and the rotational drive of the unwinding roller 51r by the unwinding roller drive unit 51d. To this end, the control device 90 controls the operation of the winding roller drive unit 53d and the unwinding roller drive unit 51d so that the tension applied to the porous imide-based resin film F is within a preset range according to the output of the tension sensor 80 acquired by the tension acquisition unit 91.

[0101] [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 above will be described. Fig. 9 is a diagram showing the flow of the method for producing a porous imide-based resin film F. Figs. 10 and 11 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.

[0102] 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.

[0103] 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. 10(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.

[0104] 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. 10(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.

[0105] 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.

[0106] 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. 10(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 areas where the fine particles A2 were present, and a porous imide-based resin film F is formed, as shown in FIG. 11(A).

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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 upper blade roller 52c while feeding the strip-shaped porous imide-based resin film F in its stretching direction.

[0113] The porous imide-based resin film Fp having a predetermined product width cut out from the cutting section 52 is guided to the winding section 53. In the winding section 53, the porous imide-based resin film Fp is wound around a core set in a winding roller 53r that is driven to rotate at a predetermined number of revolutions. In this manner, a product roll Fpr in which the porous imide-based resin film Fp is wound is produced.

[0114] Furthermore, the surplus porous imide-based resin film Fy cut off from the porous imide-based resin film F before cutting is guided to the surplus portion winding section 54. In the surplus portion winding section 54, the surplus porous imide-based resin film Fy is wound up. 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 from the slitter 5.

[0115] As described above, in the slitter 5 according to the present embodiment, the distance D3 between the outer peripheral surface of the porous imide-based resin film Fp taken up by the take-up roller 53r and the outer peripheral surface of the first guide roller 56b adjacent to the take-up roller 53r, and the distance D4 between the outer peripheral surfaces of the two adjacent first guide rollers 56a, 56b are within the range of 1 mm to 20 mm. With this configuration, it is possible to prevent the porous imide-based resin film Fp from being wrinkled when it is sent to the take-up section 53. Therefore, it is possible to prevent the porous imide-based resin film Fp from being taken up in a wrinkled state in the take-up section 53. As a result, it is possible to prevent adverse effects on the manufacturing quality of the porous imide-based resin film Fp.

[0116] In the slitter 5, at least one of the distance D1 between the outer circumferential surface of the lower blade roller 52b and the outer circumferential surface of the second guide roller 57b adjacent to the lower blade roller 52b and the distance D2 between the outer circumferential surfaces of the two adjacent second guide rollers 57a, 57b is set within a range of 1 mm to 20 mm. This configuration can prevent the porous imide-based resin film F from being wrinkled when the uncut porous imide-based resin film F is sent to the cutting section 52. As a result, the porous imide-based resin film F is prevented from being cut in a wrinkled state in the cutting section 52. As a result, adverse effects on the manufacturing quality of the porous imide-based resin film F can be prevented.

[0117] The winding roller 53r is provided so as to be movable toward and away from the adjacent first guide rollers 56a, 56b. This configuration ensures that the porous imide-based resin film Fp sent from the first guide rollers 56a, 56b to the winding section 53 starts to be wound around the winding roller 53r at a constant position. The upper blade roller 52c is also movable toward and away from the lower blade roller 52b, which facilitates maintenance of the upper blade roller 52c and the lower blade roller 52b.

[0118] Furthermore, by controlling the rotational drive of the winding roller 53r by the winding roller drive unit 53d and the rotational drive of the unwinding roller 51r by the unwinding roller drive unit 51d, it is possible to appropriately adjust the tension applied to the porous imide-based resin film F from the unwinding roller 51r to the winding roller 53r. This configuration makes it possible to prevent wrinkles from occurring in the porous imide-based resin film F. Furthermore, by adjusting the tension according to the output of the tension sensor 80, the tension of the porous imide-based resin film F can be always appropriately adjusted.

[0119] 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.

[0120] For example, in the above embodiment, the porous imide-based resin film F is used as an example of the film, but the film is not limited to this configuration. For example, the film may be a film made of a material other than the porous imide-based resin film F. [Explanation of symbols]

[0121] Reference Signs List 2...Unbaked film forming unit (first system), 3...Baking / particle removal unit (second system), 4...Etching unit (third system), 5...Slitter, 51d...Unwinding roller drive section, 51r...Unwinding roller, 52...Cutting section, 52b...Second guide roller, 52b...Lower blade roller, 52c, 52c1, 52c2, 52c3...Upper blade roller, 53d...Take-up roller drive section, 53r...Take-up roller, 56a, 56b...First guide roller, 57a, 57b...Second guide roller, 80...Tension sensor, 90...Control device, F, Fp, Fp1, Fp2...Porous imide-based resin film (film), FA...Unbaked film, FB...Baked film, S...Substrate

Claims

1. A cutting unit that cuts the strip-shaped film into multiple strips in the stretching direction of the film; a take-up roller that takes up at least one of the plurality of strips of the film cut at the cutting section; a plurality of first guide rollers supported rotatably about an axis and configured to guide the film toward the winding roller; At least one of the distance between the outer circumferential surface of the film wound by the winding roller and the outer circumferential surface of the first guide roller adjacent to the winding roller and the distance between the outer circumferential surfaces of two adjacent first guide rollers is within a range of 1 mm to 20 mm. Slitter.

2. The winding roller is provided so as to be movable toward and away from the adjacent first guide roller. The slitter of claim 1.

3. The cutting portion is a lower blade roller having an outer peripheral surface in contact with the film; an upper blade roller disposed radially outward of the lower blade roller; The film is cut into a plurality of strips by sandwiching the film between the lower blade roller and the upper blade roller. The slitter of claim 1.

4. a plurality of second guide rollers for guiding the film toward the lower blade roller; At least one of a distance between an outer peripheral surface of the lower blade roller and an outer peripheral surface of the second guide roller adjacent to the lower blade roller and a distance between the outer peripheral surfaces of two adjacent second guide rollers is within a range of 1 mm to 20 mm. The slitter of claim 3.

5. A cutting unit that cuts the strip-shaped film into multiple strips in the stretching direction of the film; a take-up roller for taking up at least one of the plurality of strips of the film cut at the cutting section; a plurality of second guide rollers supported rotatably about an axis and configured to guide the film toward the cutting section; the cutting unit includes a lower blade roller, the outer peripheral surface of which is in contact with the film, and an upper blade roller disposed radially outward of the lower blade roller, and the film is cut into a plurality of strips by sandwiching the film between the lower blade roller and the upper blade roller; At least one of a distance between an outer peripheral surface of the lower blade roller and an outer peripheral surface of the second guide roller adjacent to the lower blade roller and a distance between the outer peripheral surfaces of two adjacent second guide rollers is within a range of 1 mm to 20 mm. Slitter.

6. The upper blade roller is movable forward and backward relative to the lower blade roller. The slitter according to claim 3 or claim 5.

7. a winding roller drive unit that drives the winding roller to rotate; an unwinding roller that unwinds the film before it is cut; an unwinding roller drive unit that drives the unwinding roller to rotate; a control device for controlling the operation of the winding roller drive unit and the unwinding roller drive unit, the control device adjusts the tension applied to the film from the unwinding roller to the winding roller by controlling the rotational drive of the winding roller by the winding roller drive unit and the rotational drive of the unwinding roller by the unwinding roller drive unit. The slitter according to claim 1 or claim 5.

8. a tension sensor for measuring the tension of the film from the unwinding roller to the take-up roller; the control device controls operations of the take-up roller drive unit and the unwinding roller drive unit in response to an output of the tension sensor. The slitter of claim 7.

9. A system for producing a porous imide-based resin film, comprising: A first system applies a coating liquid containing fine particles onto a substrate and then dries the coating liquid to form a strip-shaped unfired film; a second system for forming a band-shaped porous imide-based resin film by baking the unbaked film formed in the first system and then removing the fine particles; a third system for performing a chemical etching process to dissolve a part of the porous imide-based resin film formed in the second system; and the slitter according to claim 1 or claim 5, which cuts at least one of the porous imide-based resin films formed by the second system and the third system into a plurality of strips. A manufacturing system for porous imide resin membranes.

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