JP2009079116A - Production method and production equipment for porous structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a porous structure of good quality easily and inexpensively. <P>SOLUTION: This method comprises steps of casting a solution containing a raw material polymer and a solvent on a casting belt, forming a cast film 22 on the casting belt, feeding a regulated air on a surface 22a of the cast film 22 to evaporate the solvent involved in the film 22, and forming water droplets on the surface 22a through the evaporation. In the method, an image sensor 61d detects a state of the surface 22a within a detection range A1 as a picture signal. A control part 88 detects a boundary B1 between a formed range 90 and non-formed range 91 from the picture signal to generate an approximate boundary B2 based on the boundary B1. The control part 88 controls a distance CL1 between a blast area 61f, from where the regulated air is fed, and the approximate boundary B2 to be within a predetermined range. The control of the distance CL1 permits an optimal condition to be maintained and enables a water droplet formation process to proceed. Based on the method, a porous structure with uniform pores can be manufactured easily. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method and manufacturing equipment for a porous structure, and more particularly to a manufacturing method and manufacturing equipment for a porous structure having a fine pattern.

  Today, in the optical field and the electronic field, demands for higher integration, higher information density, and higher definition of image information are increasing. Therefore, it is strongly required to form a finer structure (fine pattern structure) (fine patterning) for films used in these fields. In research in the field of regenerative medicine, a membrane having a fine structure on the surface is effective as a material for cell culture.

  Various methods such as vapor deposition using a mask, photochemical reaction and photolithographic technique using a polymerization reaction, and laser ablation technique have been put to practical use for fine patterning of a film.

  It is known that a porous structure such as a porous film having a micron-scale honeycomb structure can be obtained by casting a dilute solution of a predetermined polymer under high humidity (see, for example, Patent Document 1). The outline of the manufacturing method of this porous structure is demonstrated easily. First, a solution in which a polymer is dissolved in a hydrophobic solvent is cast on a support to form a cast film on the support. Next, the solvent contained in the cast film is evaporated. With this evaporation, the temperature on the surface of the cast film reaches condensation, and a large number of water droplets are formed on the surface of the cast film. Then, the dried air is applied to the cast film to evaporate the solvent contained in the cast film. In the evaporation of the solvent, the water droplet does not evaporate, and enters the cast film while maintaining its shape or growing. Thus, self-supporting property is exhibited in the cast film by sufficiently evaporating the solvent. Finally, the water droplets that have entered the cast film having self-supporting properties are evaporated. Thus, a porous structure having a large number of pores can be obtained by evaporation of the water droplets.

Moreover, the film in which the fine patterning is formed also in the polarizing plate is used. An example of such a film is a film that exhibits an antireflection function having a moth-eye structure. This film has regular fine patterning of submicron to several tens of microns. The mainstream among the forming methods is a method of creating a plate using a micro processing technique centered on photolithography and transferring the structure of the plate to a film (for example, see Patent Document 2).
JP 2001-157574 A JP 2003-302532 A

  In the method described in Patent Document 1, when producing a porous structure having pores that are uniformly arranged and have uniform dimensions, a water droplet forming step for forming water droplets on the surface of the cast film or the surface is formed. In the water droplet growth process for growing the water droplets, the size and arrangement of the water droplets formed are governed by atmospheric conditions such as the temperature of the surface of the cast film and the dew point of the air around the surface. Therefore, in order to produce a porous structure that is uniformly arranged and has pores with uniform individual dimensions, it is desirable to perform a water droplet formation step and a water droplet growth step under appropriately controlled atmospheric conditions. . However, in the water droplet formation step and the water droplet growth step, evaporation of the solvent accompanied by the endotherm of the system and condensation of the water droplet accompanied by the heat generation of the system coexist. Therefore, it is very difficult to maintain appropriate atmospheric conditions in the water droplet formation process and the water droplet growth process.

  The method described in Patent Document 2 is called a top-down method, and in this method, a plate for determining the fine structure is produced as described above. The production of the plate is complicated, requires many steps, and requires high costs. There is also a problem that it is difficult to manufacture a plate having a large area.

  In view of the above problems, an easy and inexpensive manufacturing method and manufacturing equipment for a porous structure having pores that are uniformly arranged and have uniform dimensions are provided.

  In the present invention, a solution in which a polymer as a raw material of a porous structure is dissolved in a hydrophobic solvent is cast on a support, a cast film is formed on the support, and the conditions are adjusted to a predetermined condition. Applying regulated air to the cast film, evaporating the solvent contained in the cast film, forming water droplets on the surface of the cast film by condensation, and growing the water droplets formed on the surface, In the method of manufacturing a porous structure having pores formed by the evaporation of water droplets, from the observation of the surface of the cast film, the range on which the water droplets are formed and the water droplets are formed. The temperature of the surface of the cast film, the wind speed of the conditioned air, and the conditioned air are set so as to satisfy the water droplet formation condition that sets a boundary with a non-existing range and can uniformly form the arrangement and dimensions of the water droplets And dew point, and adjusting at least one of a distance between the blower opening for feeding the adjusted air toward the casting film and the boundary.

  It is preferable that a line that approximates the boundary is calculated as an approximate boundary, and the support or the air blowing port is moved so that the distance between the air blowing port and the approximate boundary satisfies the water droplet formation condition. Moreover, it is preferable to set the said boundary using an image sensor.

  The present invention also provides a cast film forming method in which a support and a solution in which a polymer as a raw material for a porous structure having hydrophobicity is dissolved are cast on the support and a cast film is formed on the support. Means, water droplet forming means for forming water droplets on the surface of the cast film by condensation while evaporating the solvent contained in the cast film, water droplet growing means for growing the water droplets, Water droplet evaporating means for evaporating water droplets, and control means for controlling the water droplet forming means so as to satisfy a water droplet forming condition capable of uniformly forming an array and dimensions of the water droplets in a porous structure manufacturing facility comprising: , An observation means for observing the surface, and setting a boundary between a range where the water droplet is formed on the surface and a range where the water droplet is not formed on the surface from the observation Boundary setting means, wherein the control means moves at least one of the support and the evaporation means, and surface temperature control means controls the temperature of the surface of the cast film. , At least one of wind speed control means for controlling the wind speed of the air hitting the surface, and dew point control means for controlling the dew point of air around the surface, the control means comprising the boundary and the cast The moving means, the surface temperature control means, and the distance between the air blowing outlet for sending the regulated air toward the membrane, the surface temperature, the wind speed, and the dew point satisfy the water droplet formation condition. And controlling at least one of the wind speed control means and the dew point control means.

  The control means includes calculation means for calculating a line obtained by approximating the boundary as an approximate boundary, and the distance, the surface temperature, the wind speed, and the dew point satisfy the water droplet formation condition. Thus, it is preferable to control the water droplet forming means. The observation means is preferably an image sensor.

  According to the method for producing a porous structure of the present invention, from the observation of the surface of the cast film, a boundary between the range where the water droplets are formed and the range where the water droplets are not formed is formed on the surface. The temperature of the surface of the cast film, the wind speed of the conditioned air, the dew point of the conditioned air, and the boundary so as to satisfy the water droplet formation conditions that can be set and uniformly form the array and dimensions of the water droplets In order to adjust at least one of the distance to the blower opening for sending the conditioning air toward the cast film, it is easy to form water drops with uniform arrangement and dimensions on the cast film in the water drop forming step. Become. That is, according to the present invention, it is possible to easily manufacture a porous structure that is uniformly arranged and has pores having uniform dimensions. Further, in the present invention, since it is not necessary to prepare a plate, the porous structure can be manufactured at a low cost.

  The present invention uses an image sensor to detect the progress of water droplet formation on the surface of the cast film, thereby contributing to the evaporation of the solvent according to the water droplet formation distribution and the size of the water droplets on the surface of the cast film. Allows to control factors. Such control facilitates uniform formation of water droplets of uniform dimensions on the cast film. That is, according to the present invention, a porous structure having pores having a desired size can be easily produced.

  The porous structure manufacturing facility of the present invention includes a control means for controlling the water droplet forming means and an observation for observing the surface so as to satisfy a water drop forming condition capable of uniformly forming the arrangement and dimensions of the water drops. And a boundary setting means for setting a boundary between a range where the water droplets are formed on the surface and a range where the water droplets are not formed from the observation, and the control means includes the support body. And moving means for moving at least one of the evaporation means, surface temperature control means for controlling the temperature of the surface of the cast film, wind speed control means for controlling the wind speed of the air that hits the surface, At least one of dew point control means for controlling the dew point of air around the surface, and the control means is a distance between the boundary and the blower outlet for sending the conditioning air toward the cast film; At least one of the moving means, the surface temperature control means, the wind speed control means, and the dew point control means so that the surface temperature, the wind speed, and the dew point satisfy the water droplet formation condition. Therefore, it is possible to easily and inexpensively manufacture a porous structure having uniformly arranged and uniform pores.

(Method for producing porous structure)
FIG. 1 is an explanatory view schematically showing a porous structure manufacturing process 10 according to the present invention in FIG. 1 and a porous structure manufacturing process 10 in FIG. 2 as a model. The porous structure manufacturing process 10 includes a casting process 11, a water droplet formation process 12, a water droplet growth process 13, and a water droplet evaporation process 14. The porous structure 15 is manufactured by the porous structure manufacturing process 10.

  In the casting step 11, the above-described solution is cast on the support 21 (see FIG. 2A) to form a cast film 22 (see FIG. 2A). This solution is obtained by dissolving a polymer as a raw material of the porous structure in a solvent. There are two methods for casting the solution: a method in which the solution is spread on a stationary support and spread, and a method in which the solution flows out of the casting die on the traveling support. Can be used. In general, the former is suitable for producing a variety of products with a small production volume, and the latter is suitable for mass production. In the latter method, by continuously or intermittently discharging the solution from the casting die, a long porous structure or a porous structure having a predetermined length is continuously manufactured. Can do.

  In the water droplet forming step 12, as shown in FIGS. 2 (a) and 2 (b), air 200 adjusted to a desired condition (hereinafter referred to as adjusted air) 200 is applied to the surface 22a of the cast film 22, and the cast film 22 and the solvent 23 evaporates from the surface 22a. As the solvent 23 evaporates, the temperature of the air around the surface 22a decreases. As the temperature decreases, water vapor contained in the air around the surface 22a condenses. In the reaction between the evaporation of the solvent 23 and the condensation of water vapor, when the temperature around the surface 22a is the same as or lower than the dew point in the reaction between the evaporation of the solvent 23 and the condensation of water vapor, water droplets 25 are formed on the surface 22a. . The water droplet 25 generated at this time is very small and cannot be recognized with the naked eye. In the water droplet forming step 12, damp air may be used instead of the regulated air 200. By applying this moist air to the cast film 22, water droplets 25 can be formed on the surface 22a. Further, in the water droplet forming step 12, either case of starting the evaporation of the solvent and forming the water droplet 25 on the surface 22a at the same time, or starting one of them first may be used.

  In the water droplet growth step 13, as in the water droplet formation step 12, the controlled air 200 is applied to the surface 22a, and the water droplet 25 formed on the surface 22a is slowly grown while the solvent 23 is evaporated. The water droplet 25 does not evaporate and enters the cast film 22 as shown in FIG. The purpose of this water droplet growth step 13 is to combine a plurality of extremely small water droplets generated in the water droplet formation step 12 to enlarge the water droplets, but depending on the temperature of the surface 22a of the cast film 22 and the conditions around the cast film 22 Then, there may be a phenomenon in which each extremely small water droplet generated in the water droplet forming step 12 becomes a nucleus and becomes larger.

  Then, when the water droplet 25 has a desired size, the water droplet 25 in the cast film 22 is evaporated as water vapor 27 as shown in FIG. When the solvent 23 remains in the cast film 22, the conditions are such that the water droplet 25 is evaporated after the solvent 23 is evaporated as much as possible. As this condition, for example, a compound having a boiling point lower than that of water is used as the solvent, or the vapor pressure of water or the solvent contained in the atmosphere of the cast film 22 is adjusted to a desired range. The cast film 22 from which the solvent 23 has been sufficiently removed exhibits self-supporting properties. Next, the water droplets 25 that have entered the cast film 22 having self-supporting properties are evaporated. The porous structure 15 can be generated from the cast film 22 by evaporation of the water droplets 25. If the support 21 is unnecessary, it may be peeled off after or during the formation of the porous structure 15.

  FIG. 3 is a schematic view of the porous structure 15. A very large number of holes 31 are densely formed in the porous structure 15 peeled off from the support 21 (see FIG. 2). (A) is a top view of the porous structure 15 obtained by this invention, (B) is sectional drawing which follows the bb line of (A), (C) is along the cc line of (A). It is sectional drawing. Further, (D) is a cross-sectional view of another porous structure 33, but the plan view of the porous structure 33 is the same as (A) and is omitted.

  As shown in FIG. 3A, the holes 31 are arranged on the porous structure 15 so as to form a honeycomb structure, a so-called honeycomb structure. And as shown to FIG. 3 (B) and (C), the hole 31 may be formed so that it may penetrate through both surfaces of the porous structure 15, or like the porous structure 33 of (D). In some cases, the recess 33a is formed on one side. The arrangement of the holes 31 varies depending on the density and size of the water droplets, the type of water droplets to be formed, the drying speed, the solid concentration of the solution, the timing of evaporation of the solvent 23 with respect to the water droplet growth degree in the water droplet growth process, and the like. It will be a thing. The form of the porous structure 15 produced according to the present invention is not particularly limited. However, in the present invention, for example, the thickness L1 of the porous structure 15 is 0.05 μm or more and 100 μm or less, and the diameter D1 of the hole 31 is Is particularly effective when a porous structure having a hole pitch of 31 μm or more and 0.1 μm or more and 120 μm or less is formed.

  As described above, the honeycomb structure means a structure in which holes having a fixed shape and a fixed size are arranged continuously and regularly. This regular arrangement is two-dimensional in the case of a single layer and regular in three dimensions in the case of a multilayer. This regularity is two-dimensionally arranged so that a plurality of (for example, six) holes surround one hole, and three-dimensionally a structure such as a face-centered cubic or hexagonal crystal structure. In many cases, close packing is performed, but regularity other than these may be exhibited depending on manufacturing conditions.

(solution)
The solution used in the present invention contains a polymer that is a raw material for the porous structure (hereinafter referred to as a raw material polymer) and a solvent that can dissolve the raw material polymer. The concentration of the raw material polymer in the solution when casting may be a concentration that can form the cast film 22, and specifically, it is preferably in the range of 0.02 wt% to 30 wt%. If the concentration of the raw material polymer is less than 0.02% by weight, the productivity of the film may be inferior and not suitable for mass production. In addition, if the concentration of the raw material polymer exceeds 30% by weight, the water droplet forming step 12 dries before the water droplets are sufficiently grown. It may be difficult to make.

(solvent)
The solvent used in the present invention may be any as long as it satisfies the following.
(1) A material capable of dissolving a raw material polymer of a porous structure.
(2) Those having hydrophobic properties.

  As the hydrophobic solvent, those having a water solubility of 5% by weight or less are preferable. For example, halogen organic solvents such as chloroform and dichloromethane, aromatic hydrocarbons such as benzene, toluene and xylene, ethyl acetate, butyl acetate and the like. Esters, water-insoluble ketones such as methyl isobutyl ketone, ethers such as diethyl ether, carbon disulfide and the like. Among the compounds described above, a solvent composed of two or more kinds of compounds may be used as a hydrophobic solvent. By appropriately changing the ratio of these compounds, it is possible to control the droplet formation rate, the depth of penetration of the droplet into the cast film, and the like.

(Raw polymer)
As the raw material polymer of the porous structure, a polymer compound, an amphiphilic compound, or the like can be used.

(Polymer compound)
Although it does not specifically limit as a high molecular compound, Although it can determine according to a use etc., that whose number average molecular weight (Mn) is 1,000-10,000,000 is preferable, 5000- More preferred is 1,000,000.

  As this polymer compound, those which are soluble in a water-insoluble solvent, that is, a hydrophobic solvent are preferable. For example, poly-ε-caprolactone, poly-3-hydroxybutyrate, agarose, poly-2-hydroxyethyl acrylate, polysulfone, etc. Is preferred. Poly- [epsilon] -caprolactone is particularly preferable when biodegradability is required, or in consideration of cost and availability.

  Other examples of the polymer compound include vinyl polymerized polymers (for example, polyethylene, polypropylene, polystyrene, polyacrylate, polymethacrylate, polyacrylamide, polymethacrylamide, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyhexafluoro Propene, polyvinyl ether, polyvinyl carbazole, polyvinyl acetate, polyvinyl carbazole, polytetrafluoroethylene, etc.), polyester (eg, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, polybutylene succinate, polylactic acid, etc.), polylactone (eg, Polycaprolactone etc.), polyamide or polyimide (eg nylon or polyamic acid etc.), polyurethane, polyurea, poly Boneto, polyaromatics, polysulfones, polyethersulfones, polysiloxane derivatives, and the like. These may be homopolymers, copolymers, polymer blends, or polymer alloys from the viewpoints of solubility, optical physical properties, electrical physical properties, strength, elasticity, and the like.

(Amphiphilic compounds)
The amphiphilic compound is a substance having hydrophilicity and lipophilicity, and specifically, a compound having a hydrophilic group and a hydrophobic group. As such an amphiphilic compound, oligomers such as dimers and trimers, and polymer compounds can be used in addition to many commercially available monomers such as surfactants. By mixing the amphiphilic compound and the polymer compound, water droplets are easily formed on the surface of the cast film. Further, by controlling the dispersion state with respect to the polymer compound, the position where water droplets are formed can be more easily controlled.

  An example of an amphiphilic compound is polyacrylamide. Examples of other amphiphilic polymer compounds include polyacrylamide as a main chain skeleton, a dodecyl group as a lipophilic side chain, a carboxyl group as a hydrophilic side chain, and a polyethylene glycol / polypropylene glycol block copolymer. . The lipophilic side chain is a non-polar linear group such as an alkylene group or a phenylene group, and has a hydrophilic group such as a polar group or an ionic dissociation group to the end, excluding a linking group such as an ester group or an amide group. A structure that does not branch is preferable. For example, when using an alkylene group, the lipophilic side chain preferably comprises 5 or more methylene units. The hydrophilic side chain preferably has a structure having a polar part, an ionic dissociation group, or a hydrophilic part such as an oxyethylene group at the terminal via a linking part such as an alkylene group.

  As the amphiphilic compound, it is preferable to use two or more kinds of compounds different from each other because the formation position of the water droplet and the size of the water droplet can be controlled. Moreover, the same effect can be acquired also about a high molecular compound by using 2 or more types of compounds which are mutually different. In addition, you may use said amphiphilic compound as a high molecular compound.

  The polymer compound and the amphiphilic compound may be a polymerizable (crosslinkable) polymer compound having a polymerizable group in the molecule. In addition, a polymerizable polyfunctional monomer is blended together with a polymer compound and an amphiphilic compound, and a porous structure is formed from this blend. Then, a heat curing method, an ultraviolet curing method, an electron beam curing method, etc. are known. Curing treatment may be performed by the method.

  The polyfunctional monomer used in combination with the polymer compound or the amphiphilic compound is preferably a polyfunctional (meth) acrylate from the viewpoint of reactivity. Examples of the polyfunctional (meth) acrylate include dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dipentaerythritol caprolactone adduct hexaacrylate or a modified product thereof, epoxy acrylate oligomer, polyester acrylate oligomer, Urethane acrylate oligomer, N-vinyl-2-pyrrolidone, tripropylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or a modified product thereof can be used. These polyfunctional monomers are used singly or in combination of two or more from the balance of scratch resistance and flexibility. When the polymer compound or amphiphilic compound is a polymerizable (crosslinkable) compound having a polymerizable group in the molecule, it is also preferable to use a polymerizable polyfunctional monomer that can react with the polymerizable group. .

  Among the above, the polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator. Therefore, for example, after preparing a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler, and coating the coating liquid on a transparent support When cured by a polymerization reaction with ionizing radiation or heat, an antireflection film can be produced.

  Examples of radical photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-alkyldione compounds, disulfides Examples include compounds, fluoroamine compounds and aromatic sulfoniums.

  Examples of the acetophenones include 2,2-ethoxyacetophenone, p-methylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone, 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone and the like.

  Examples of the benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

Examples of the benzophenones include benzophenone, 2,4-chlorobenzophenone, 4,4-dichlorobenzophenone, p-chlorobenzophenone, and the like.
Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  Various examples of the photo-radical polymerization initiator are also described in the latest UV curing technology (P.159, issuer: Kazuhiro Takasato, publisher; Technical Information Association, published in 1991). Yes. Further, as a commercially available photocleavable photoradical polymerization initiator, Irgacure (651, 184, 907) manufactured by Ciba Specialty Chemicals Co., Ltd. and the like are preferable examples. It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, and it is more preferable to use it in the range of 1-10 mass parts. In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, and thioxanthone.

  As said thermal radical initiator, an organic peroxide, an inorganic peroxide, an organic azo compound, an organic diazo compound, etc. can be used, for example. Examples of the organic peroxide include benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide, and the like. Examples of inorganic peroxides include hydrogen peroxide, ammonium persulfate, and potassium persulfate. Examples of the azo compound include 2,2'-azobis (isobutyronitrile), 2,2'-azobis (propionitrile), 1,1'-azobis (cyclohexanecarbonitrile), and the like. Examples of the diazo compound include diazoaminobenzene, p-nitrobenzenediazonium, and the like.

  As shown in FIG. 4, the porous structure manufacturing facility 40 includes a casting chamber 41. The casting chamber 41 is provided with a casting belt 42 that is a running support and a casting die 44 that allows the solution 43 to flow out onto one surface (hereinafter referred to as a casting surface) 42a of the casting belt 42. Is done. The casting chamber 41 includes a first area 46 to a third area 48, and the casting die 44 is disposed in the first area 46. The casting belt 42 is stretched around rollers 52 and 53. At least one of the rollers 52 and 53 is rotated by a driving device (not shown). As the rollers 52 and 53 rotate, the casting belt 42 sequentially travels endlessly in each of the first area 46, the second area 47, and the third area 48.

  The solution 43 is preferably filtered in advance before being sent to the porous structure manufacturing facility 40. As a result, foreign matters can be prevented from entering the porous structure 15. Filtration is preferably performed a plurality of times. For example, when the filtration is performed twice, the upstream filtration device (not shown) is provided with a filter having an absolute filtration accuracy (absolute filtration pore diameter) larger than the pore diameter of the porous structure 15, and the downstream side. It is preferable that the filtration device (not shown) is provided with a filter having an absolute filtration accuracy smaller than the gap of the porous structure 15.

  Further, the temperature controller 54 controls the temperature of the rollers 52 and 53, thereby controlling the temperature of the casting surface 42a of the casting belt 42 in contact with the rollers 52 and 53 within a desired range. In this way, the temperature controller 54 adjusts the temperature (hereinafter referred to as the surface temperature) of the surface 22a of the cast film 22 formed on the casting surface 42a to a desired range via the rollers 52 and 53. can do. In particular, such a casting belt 42 is effective when the condition control of the air around the cast film 22 cannot be instantaneously changed.

  Examples of a method for adjusting the temperature of the casting surface 42a by the temperature controller 54 include a method in which a liquid flow path through which the heat transfer medium flows is provided inside the rollers 52 and 53, and the temperature-controlled heat transfer medium is fed. It is done. The temperature of the casting belt 42 is preferably set to a lower limit value of 0 ° C. or higher. Moreover, it is preferable to make it an upper limit into below the boiling point of a solvent, More preferably, it is setting it as (boiling point of a solvent-3) degreeC. Thereby, the condensed moisture does not solidify, and the solvent in the cast film 22 is suppressed from rapidly evaporating. Therefore, the porous structure 15 having excellent void size, uniformity, shape, and the like. Can be obtained. Furthermore, the temperature of the casting surface 42a can be within ± 3 ° C. in the width direction of the cast film 22, so that the variation due to the position of the surface temperature can be within ± 3 ° C. in the width direction. . By suppressing the variation in temperature in the width direction of the cast film 22, it is possible to suppress the occurrence of anisotropy in the pores of the porous structure 15, thereby improving the quality as the porous structure.

  A tank (not shown) in which the solution 43 is stored is connected to the casting die 44 through a pipe. The temperature of the solution 43 stored in the tank is maintained so as to be in a desired range (0 ° C. or more and 50 ° C. or less). The solution 43 flows out from the casting die 44 onto the casting belt 42. Thus, the solution 43 is cast on the casting surface 42a of the running casting belt 42, and the cast film 22 is formed.

  In the first area 46, the air intake / intake unit 61 is disposed. In the first area 46, using the air intake / intake unit 61, the adjusted air adjusted to a desired condition is applied to the cast film 22 to form water droplets on the surface 22a, that is, to perform the water droplet forming step 12. Objective. Details of the first area 46 will be described later.

  In the second area 47, two air intake / intake units 63 and 64 are arranged along the traveling direction of the casting belt 42. The upstream air intake / intake unit 63 is disposed immediately downstream of the air intake / intake unit 61 in the first area 46. The upstream air intake / intake unit 63 is disposed immediately downstream of the air intake / intake unit 61 in the first area 46. The blower intake units 63 and 64 include blower ports 63a and 64a and intake ports 63b and 64b. The blower openings 63 a and 64 a flow adjustment air toward the surface 22 a of the cast film 22. The intake ports 63b and 64b suck in the gas around the cast film 22. The blower / intake units 63 and 64 respectively send adjusted air adjusted to a desired condition toward the cast film 22 by a control unit (not shown), and suck the gas around the surface 22a with a desired suction force.

  The main purpose of the second area is to use these air intake and intake units 63 and 64 to apply the regulated air to the cast film 22 and to uniformly grow the water droplets formed in the first area 46. The more the first area 46 and the second area 47 are separated from each other, that is, the longer the time from the formation of the water droplet to the entry into the second area 47, the more uneven the size of the water droplet when it has grown. End up. The number of the ventilation intake units is not limited to the number of the present embodiment, that is, 2 and may be 1 or 3 or more. The air intake and intake units 63 and 64 are the same as the air intake and intake unit 61, but are not limited thereto.

  In the third area 48, four air intake / intake units 71 to 74 are arranged in order along the traveling direction of the casting belt 42. The number of the air intake and intake units is not limited to the number of the present embodiment, that is, 4 and may be 1 or more and 3 or less or 5 or more. The air intake / intake units 71 to 74 are the same as the air intake / intake units 63 and 64, but are not limited thereto. The blower / intake units 71 to 74 send out air adjusted to a desired condition by a control unit (not shown).

  The main purpose of the third area 48 is to evaporate water droplets, that is, to perform the water droplet evaporation step 14, but the solvent that could not be evaporated before reaching the third area 48 is also evaporated.

  The blowing speed of the air sent out from the blowing intake units 71 to 74 is preferably 0.01 m / second or more and 20 m / second or less, more preferably 0.5 m / second or more and 15 m / second or less, Preferably, the range is from 1 m / second to 10 m / second. If the blowing speed is less than 0.01 m / sec, the evaporation of water droplets may not proceed sufficiently, and productivity may be reduced. On the other hand, if the air blowing speed exceeds 20 m / sec, evaporation of water droplets occurs abruptly and the shape of the formed holes may be disturbed.

  At least any of the dew point TD2 of the air sent out from the blower intake units 71 to 74 and the surface temperature TL of the cast film 22 in the third area 48 should satisfy the condition of 80 ° C. ≧ (TL−TD2) ° C. ≧ 1 ° C. It is preferable to control one of them. Thereby, the growth of water droplets can be stopped and the water droplets can be evaporated as water vapor. When (TL-TD2) is less than 1 ° C., the growth of water droplets cannot be reliably stopped, and the accuracy of the hole size may be reduced. On the other hand, when (TL-TD2) exceeds 80 ° C., the evaporation of the organic solvent and water droplets becomes abrupt, and the arrangement, shape and size of the regularly arranged water droplets are disturbed and a uniform honeycomb structure is expressed. Disappear.

  Each variation of the surface temperature TL immediately before entering the third area 48, the dew point near the conveyance path immediately before the third area 48, and the dew point near the conveyance path immediately after entering the third area 48 are all ± It is preferably within 3 ° C.

  Moreover, it is preferable to provide a condenser at a position away from the surface 22a by about 3 mm to 20 mm. This condenser makes it possible to condense water vapor and volatile organic solvent in the vicinity of the condenser surface so that the concentration of water and solvent gas in the vicinity of the surface 22a is not increased. In this way, the cast film 22 in the third area 48 can be more reliably dried. By applying at least one of the drying methods as described above, it is possible to reduce the dynamic influence on the film surface of the cast film 22, so that a smoother film surface can be obtained. Obtainable.

  In the third area 48, a vacuum drying apparatus or a so-called 2D nozzle may be used instead of the blower suction units 71 to 74. By performing drying under reduced pressure, it becomes easier to adjust the evaporation rates of the solvent and the water droplets, respectively. Thereby, the evaporation of the organic solvent and the evaporation of the water droplets can be made better, and the water droplets can be formed inside the cast film 22 better. The 2D nozzle has an air supply nozzle member that emits air and an exhaust nozzle member that sucks air in the vicinity of the cast film 22. The 2D nozzle is preferably one that can uniformly supply and exhaust air over the entire width of the cast film. Note that a vacuum drying apparatus and a 2D nozzle may be used in the first area 46 and the second area 47.

  Furthermore, the porous structure manufacturing facility 40 includes a peeling roller 80 that supports the porous structure 15 peeled off from the casting belt 42 when the cast film 22 is peeled off from the casting belt 42. The porous structure 15 peeled off by 80 is sent to the next process. The next step is, for example, a function providing step for performing various functions on the porous structure 15 or a winding step for winding the porous structure 15 into a roll.

  Next, details of the first area 46 will be described. As shown in FIG. 5, a ventilation intake unit 61 is provided on the downstream side in the traveling direction of the casting belt 42 when viewed from the casting die 44. The blower intake unit 61 includes a blower port 61a, an intake port 61b, a blower controller 61c, and an image sensor 61d. The blower opening 61 a allows adjustment air to flow toward the surface 22 a of the cast film 22. The air inlet 61b sucks the gas around the cast film 22. The blower controller 61c independently controls the temperature, dew point, humidity, wind speed, and suction force in the intake system of the regulated air in the blower system. In this way, the blower intake unit 61 applies the adjusted air adjusted to a desired condition to the cast film 22 and sucks the gas around the cast film 22 with a desired suction force.

  At least one of the dew point TD1 of the regulated air from the blower intake unit 61 and the surface temperature TL of the cast film 22 that passes through the first area 46 is such that the condition of 0 ° C. ≦ (TD1-TL) is satisfied. Be controlled. Thereby, the water vapor in the regulated air flowing in the vicinity of the cast film 22 can be generated as a water droplet and can be grown. More preferably, 0 ° C. ≦ (TD1-TL) ≦ 80 ° C., still more preferably 0 ° C. ≦ (TD1-TL) ≦ 30 ° C., and most preferably 0 ° C. ≦ (TD1-TL) ≦ 10 ° C. . When (TD1-TL) is less than 0 ° C., condensation may hardly occur on the surface 22a. In addition, when (TD1-TL) exceeds 80 ° C., the speed of condensation, that is, the water droplet generation rate becomes too high, and water droplets are further formed on the water droplets, so that the pore size of the porous structure 15 is not good. Uniformity, that is, the structure may be uneven. The temperature of the regulated air is not particularly limited, but is preferably in the range of 5 ° C. or more and 100 ° C. or less. If the temperature exceeds 100 ° C., water droplets may evaporate before entering the cast film 22.

  In the first area 46, it is preferable to apply the regulated air to the cast film 22 from one direction, and it is more preferable to have a tailwind (parallel flow) parallel to the cast film 22. Moreover, it is preferable that the variation in the angle at which the regulated air hits the cast film 22 is an angle that is within ± 20 °. When the regulated air is blown as a countercurrent, it is difficult to control the speed of the regulated air when the relative speed between the regulated air and the cast film 22 is low, and the surface 22a of the cast film 22 is disturbed and loses smoothness. The growth of water droplets on the surface 22a may be inhibited. Further, the air blowing speed of the regulated air is preferably in the range of 0.01 m / second to 10 m / second relative to the moving speed of the cast film 22, that is, the traveling speed of the casting belt 42, and more preferably. The range is from 0.05 m / second to 5 m / second, and most preferably from 0.1 m / second to 1 m / second. If the relative speed is less than 0.01 m / second, the cast film 22 may be transported to the second area 47 or the third area 48 before the water droplets are formed in a fine array. On the other hand, if the relative speed exceeds 10 m / sec, the surface 22a of the cast film 22 is disturbed, and the formation of water droplets may not proceed sufficiently.

  The variation in the blowing speed of the regulated air, the running speed of the casting belt 42, and the relative speed is preferably within ± 20% with respect to the average value of the relative speed. The effect of making the state of water droplets uniform is further enhanced by this condition and the condition of the regulated air. The adjustment of the relative speed can be performed by adjusting at least one of the speed of the regulated air and the transport speed of the cast film 22.

  The time for the cast film 22 to pass through the first area 46 and the second area 47 (hereinafter referred to as “passing time”) is preferably 0.1 seconds or more and 1000 seconds or less. Thereby, sufficient water droplets can be generated uniformly to fill the holes finely. If the passage time is less than 0.1 seconds, it is difficult to form the desired holes because the water droplets are not sufficiently grown, or the fine holes may not be formed finely in the film. On the other hand, if the passage time exceeds 1000 seconds, the size of the water droplets may become too large to obtain the honeycomb structured porous structure 15. By controlling the time during which the cast film 22 passes through the first area 46 and the second area 47 in this way, the mode such as the size of the hole can be controlled. When the porous structure 15 is manufactured not batch-wise but batchwise, or when the porous structure 15 is manufactured not in a long form but in a sheet form or a small strip form, it passes through the first area 46 and the second area 47 described above. A similar effect can be obtained by controlling the time for placing the cast film in an environment to condense instead of the time.

  The image sensor 61d is disposed on the downstream side of the casting die 44 and on the upstream side of the air blowing port 61a and the air intake port 61b. The image sensor 61d includes an imaging surface 61e and an imaging element, and is arranged so that the imaging surface 61e faces the surface 22a of the cast film 22 formed on the casting surface 42a. The imaging device detects a state of a certain range (hereinafter referred to as a detection range) A1 (FIG. 6) on the surface 22a of the cast film 22 as a subject image via the imaging surface 61e, and an image signal is obtained from the subject image. Is generated. Any image sensor may be used as long as it has a resolution corresponding to the size of the water droplet to be detected. Specific examples of the image pickup device include a known image pickup device such as a CCD (electrically coupled device) image sensor or a CMOS image sensor, and any of them may be used. The image sensor 61d preferably includes a dew condensation prevention device. This dew condensation prevention device prevents dew condensation on the imaging surface 61e due to regulated air or the like by keeping the temperature of the imaging surface 61e within a certain range.

  The controller 88 is connected to the blower controller 61 c, the image sensor 61 d, the temperature controller 54, and the shift unit 89. The shift unit 89 is connected to the air intake / intake unit 61. The shift unit 89 under the control of the control unit 88 makes the air intake / intake unit 61 movable in the traveling direction of the casting belt 42.

  The control unit 88 performs boundary detection processing and calculation processing. As shown in FIG. 6, in the boundary detection process, the control unit 88 reads an image signal in the detection range A1 from the image sensor 61d, and generates image data corresponding to the image signal. From this image data, the control unit 88 determines a range (hereinafter referred to as a formation range) 90 in which water droplets are formed within the detection range on the surface 22a and a range in which water droplets are not formed (hereinafter referred to as unformed ranges). 91) is detected. Then, the control unit 88 detects a boundary B <b> 1 that is a boundary between the two ranges 90 and 91 by detecting the formation range 90 and the non-formation range 91. As a method of detecting the formation range 90 and the non-formation range 91, the obtained image signal is subdivided (for example, subdivided for each pixel unit of the image sensor) using a desired threshold value and binary. For example, a known image processing method can be used. The threshold for detecting these two ranges 90 and 91 is the color and reflectance of the cast film at the time of detection, or the manufacturing conditions of the target porous structure (hole size, hole formation pitch, etc.) What is necessary is just to determine according to.

  In the calculation process, the control unit 88 approximates the boundary B1 obtained by the boundary detection process, and calculates a linear approximate boundary B2. Next, an example of a method for calculating the approximate boundary B2 will be described. First, the control unit 88 calculates the area of the formation range 90 obtained by the boundary detection process. Second, the control unit 88 divides the area of the formation range 90 obtained by this calculation process by the width W1 of the cast film 22 to obtain an average distance W2. Third, the control unit 88 sets the approximate boundary B2 as a straight line that is separated from the end A2 on the downstream side in the traveling direction M1 of the detection range A1 by the average distance W1 and is substantially perpendicular to the traveling direction M1.

  Under the control of the control unit 88, the shift unit 89 moves the blower controller 61c so that the distance CL1 between the approximate boundary B2 obtained by this calculation process and the blower surface 61f of the blower port 61a is within a predetermined range. . Furthermore, the control unit 88 controls the temperature controller 54 and the air blower controller 61c as well as the position of the air blower controller 61c, and controls the surface temperature of the cast film 22, the wind speed and the dew point of the regulated air. The controller 88 controls at least one of the parameters of the distance CL1, the surface temperature, the air speed of the regulated air, and the dew point, and performs the water droplet forming step 12 so that the atmosphere of the first area 46 satisfies the water droplet forming condition. . This water droplet formation condition is a condition that allows the water droplet arrangement and dimensions to be uniformly formed on the surface 22a of the cast film 22, and differs depending on the manufacturing condition and quality condition. Therefore, the control unit 88 controls each parameter so as to be in a desired range as compared with the data mapping of each parameter obtained from a manufacturing experiment that is the same as or similar to the target manufacturing condition and quality condition. Thus, the optimum water droplet forming step 12 can be performed.

  Next, an example is given and demonstrated about the manufacturing method of the porous structure of this invention. In addition, this invention is not limited to the content described below.

  A solution 43 in which a predetermined ratio of raw material polymer is dissolved in a solvent is prepared. Next, in the first area 46, the solution 43 flows out onto the casting surface 42a of the casting belt 42 by the casting die 44 (FIG. 5). The solution 43 is cast on the casting surface 42 a by the running of the casting belt 42. Thus, the cast film 22 is formed on the casting surface 42a.

  The controller 88 reads the image signal of the detection range A1 on the surface 22a from the image sensor 61d, and generates image data. The control unit 88 performs boundary detection processing and calculation processing on the image data, and calculates an approximate boundary B2. Further, the control unit 88 moves the air intake / intake unit 61 in the traveling direction via the shift unit 89 so that the distance CL1 between the approximate boundary B2 and the air blowing surface 61f satisfies the water droplet formation condition. Along with the control of the blower intake unit 61, the control unit 88 controls the temperature controller 54 and the blower controller 61c, so that the atmosphere of the surface 22a of the cast film 22 satisfies the water droplet formation condition, and the wind speed of the regulated air. And adjust the dew point to a predetermined range. In this way, the atmosphere of the first area 46 is maintained at the water droplet formation conditions according to the target manufacturing conditions and quality conditions. By performing the water droplet formation conditions in an atmosphere that satisfies the water droplet formation conditions, water droplets having a uniform arrangement and size can be easily formed on the surface 22a. The cast film 22 is sent to the second area 47 as the casting belt 42 travels.

  As shown in FIG. 4, in the second area 47, the air intake and intake units 63 and 64 apply the adjusted air adjusted to a desired condition to the surface 22a. The solvent evaporates from the surface 22a of the cast film 22 by the regulated air from the blower intake units 63 and 64, and water droplets grow uniformly. The grown water droplets enter the cast film 22 while maintaining its shape. The cast film 22 is sent to the third area 47 as the casting belt 42 travels.

  In the third area 48, the air intake and intake units 71 to 74 apply the adjusted air adjusted to a desired condition to the surface 22a. The water droplets on the cast film 22 are evaporated by the air of the blower intake units 71 to 74. The porous structure 15 is generated from the cast film 22 by evaporation of the water droplets. The porous structure 15 is sent to the peeling roller 80 as the casting belt 42 travels. The stripping roller 80 strips the porous structure 15 from the casting belt 42 and performs the following steps such as a function providing step and a winding step.

  In the present invention, the degree of water droplet formation on the surface 22a of the cast film 22 in the water droplet forming step 12 is detected, and the surface temperature, the wind speed and dew point of the regulated air are determined in addition to the distance CL1 according to the degree of these processes. It becomes possible to adjust to the optimum range. That is, the present invention makes it possible to perform the water droplet formation step 12 under optimum conditions, and as a result, it is possible to easily manufacture the porous structure 15 having pores that are uniformly arranged and have uniform dimensions. it can.

  In the above embodiment, in the water droplet formation step, the control unit 88 is described as controlling the surface temperature, the wind speed of the regulated air, and the dew point so as to satisfy the water droplet formation condition. In order to satisfy the condition, at least one of the distance CL1, the surface temperature, the wind speed of the regulated air, and the dew point may be controlled.

  Note that the position where the boundary B1 is formed varies depending on the target manufacturing conditions. Therefore, the image sensor 61d may be arranged at a position where the boundary B1 is within the detection range A1 according to the manufacturing conditions. The installation position of the image sensor 61d may be determined with reference to data mapping obtained from a manufacturing experiment performed in advance, or positioning control by the shift unit 88 may be performed during the water droplet forming step 12.

  In the above embodiment, the approximate boundary B2 is calculated from the calculation of the area of the formation range 90. However, the present invention is not limited to this, and the area of the unformed range 91 may be calculated and the approximate boundary B2 may be calculated from the area. it can.

  As a method for calculating the approximate boundary B2, in addition to the above, a straight line that passes through an arbitrary point on the boundary B1 and is substantially perpendicular to the traveling direction M1 may be used as the approximate boundary B2. Alternatively, a plurality of arbitrary points on the boundary B1 may be selected, and a known numerical analysis such as a least square method may be performed on these points, and a straight line obtained may be used as the approximate boundary B2.

  In the above-described embodiment, it has been described that the position of the blower / intake unit 61 is controlled by the shift unit 89 in order to set the distance CL1 in a desired range. However, the present invention is not limited to this, and the range does not affect other processes. The traveling speed of the casting belt 42 may be controlled so that the distance CL1 falls within a desired range.

  In the said embodiment, although each process 11-14 was performed continuously, ie, the manufacturing equipment of the on-line system porous structure was described, this invention is not limited to the said embodiment. That is, the present invention can also be applied to a manufacturing facility for a batch type porous structure in which each of the steps 11 to 14 is performed individually, that is, an offline type. Next, an off-line porous structure manufacturing facility will be described. In addition, when using the member similar to the said embodiment, it demonstrates using the code | symbol and the detailed description is abbreviate | omitted.

  As shown in FIG. 7, the porous structure manufacturing facility 100 includes a support plate 102, a blower / intake unit 61, a control unit 104, a shift unit 62, and a temperature controller 54. The support plate 102 includes a support surface 102a. The cast film 22 is formed on the support surface 102a by flowing and extending the solution 43 on the support surface 102a.

  The blower intake unit 61 includes a blower port 61a, an intake port 61b, a blower controller 61c, and an image sensor 61d. The blower intake unit 61 applies the adjusted air adjusted to a desired condition to the cast film 22 to evaporate the solvent contained in the solution 43 from the surface 22a. Due to the evaporation of the solvent, water droplets are formed on the surface 22a. The control unit 104 connects the blower controller 61c, the shift unit 89, and the temperature controller 54. The shift unit 89 under the control of the control unit 104 is connected to the support plate 102 and makes the support plate 102 movable in the direction D1. The temperature controller 54 under the control of the control unit 104 adjusts the temperature of the support surface 102a of the support plate 102 to a desired range.

  The image sensor 61d detects the state of the surface 22a within the detection range as an image signal via the imaging surface 61e. The control unit 103 generates image data from the image signal, performs boundary detection processing and calculation processing on the image data, and sets an approximate boundary. Further, the control unit 103 adjusts the distance between the approximate boundary and the air blowing surface 61f, the surface temperature of the surface 22a, the wind speed of the regulated air, and the dew point so that the atmosphere on the surface 22a satisfies the water droplet formation condition. In this way, the water droplet forming step 12 can be performed under optimum conditions. As a result, the porous structure 15 that is uniformly arranged and has pores with uniform dimensions can be easily manufactured.

It is explanatory drawing which shows the manufacturing process of a porous structure. It is explanatory drawing which shows the outline of the process in which a porous structure is formed. It is explanatory drawing which shows the outline | summary of a porous structure. (A) is a top view of the porous structure which concerns on this invention, (B) is sectional drawing which follows the bb line of (A), (C) is sectional drawing which follows the cc line of (A). FIG. 6D is a plan view of a porous structure according to another embodiment. It is explanatory drawing which shows the outline | summary of the 1st porous structure manufacturing equipment of this invention. It is explanatory drawing which shows the outline | summary of a 1st area. It is a top view of a cast film when it sees from the VI-VI line in FIG. It is explanatory drawing which shows the outline | summary of the 2nd porous structure manufacturing equipment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Porous structure manufacturing process 11 Cast process 12 Water drop formation process 13 Water drop growth process 14 Water drop evaporation process 15, 33 Porous structure 21 Support body 22 Cast film 22a Surface 23 Solvent 31 Hole 40, 100 Porous structure manufacturing equipment 42 Solution 54 Temperature controller 61c Blower controller 61d Image sensor 61f Blower surface 88, 104 Control unit 89 Shift unit 102 Support plate

Claims (6)

Cast a solution on which the polymer as a raw material of the porous structure is dissolved in a hydrophobic solvent, onto the support,
Forming a cast film on the support,
Applying regulated air adjusted to a predetermined condition to the cast membrane,
While evaporating the solvent contained in the cast film,
Water droplets are formed on the surface of the cast film by condensation,
Growing the water droplets formed on the surface;
In the method for producing a porous structure having pores formed by the evaporation of the water droplets,
From the observation of the surface of the cast film, on the surface, set a boundary between the range where the water droplets are formed and the range where the water droplets are not formed,
The surface temperature of the cast film, the wind speed of the conditioned air, the dew point of the conditioned air, the boundary thereof, and the cast film so as to satisfy the water droplet formation conditions that can uniformly form the array and dimensions of the water droplets A method for producing a porous structure, comprising adjusting at least one of a distance from a blower opening for sending the adjustment air toward the air. Calculating a line approximating the boundary as an approximate boundary;
The method for producing a porous structure according to claim 1, wherein the support or the blower port is moved so that a distance between the blower port and the approximate boundary satisfies the water droplet formation condition.   The method for producing a porous structure according to claim 1, wherein the boundary is set using an image sensor. A support;
A cast film forming means for casting a solution in which a polymer serving as a raw material of a porous structure having hydrophobicity is cast on the support, and forming a cast film on the support;
Water droplet forming means for forming water droplets on the surface of the cast film by condensation while evaporating the solvent contained in the cast film;
Water droplet growth means for growing the water droplets;
Water droplet evaporating means for evaporating the water droplets entering the cast film;
In a production facility for a porous structure having
Control means for controlling the water droplet forming means so as to satisfy a water droplet forming condition capable of uniformly forming an array and dimensions of the water droplets;
Observation means for observing the surface;
From the observation, boundary setting means for setting a boundary between a range where the water droplets are formed on the surface and a range where the water droplets are not formed;
Have
The control means includes a moving means for moving at least one of the support and the evaporation means, a surface temperature control means for controlling the temperature of the surface of the cast film, and a wind speed of the air hitting the surface. At least one of wind speed control means for controlling and dew point control means for controlling the dew point of air around the surface,
The control means is configured so that the distance between the boundary and the air blowing port for sending the regulated air toward the cast film, the surface temperature, the wind speed, and the dew point satisfy the water droplet formation condition. At least one of a moving means, the surface temperature control means, the wind speed control means, and the dew point control means is controlled. The control means is
Calculating means for calculating a line obtained by approximating the boundary as an approximate boundary;
5. The production of the porous structure according to claim 4, wherein the water droplet forming means is controlled so that the distance, the surface temperature, the wind speed, and the dew point satisfy the water droplet formation condition. Facility.   6. The manufacturing facility for a porous structure according to claim 4, wherein the observation means is an image sensor.

Images