JP6059062B2 - Method for producing metal-containing film - Google Patents

Description

  The present invention relates to a method for producing a metal-containing film.

  Conventionally, various functions of metal ions have been attracting attention and utilized. For example, it has been proposed to separate paraffins such as propane and olefins such as propylene using a separation membrane in which silver ions are introduced into a thin film having micropores or mesopores (see Non-Patent Document 1). Further, it has been proposed to permeate and concentrate oxygen from the air using a film in which a cobalt complex of a porphyrin compound is dispersed in a polymer (see Patent Document 1).

  By the way, although such a film | membrane may be used as a self-supporting film | membrane, it is often formed and used on the surface of a porous base material. As a method for forming a film on the surface of the porous substrate, for example, a sulfonated polyarylether polymer solution is attached to the surface of the porous substrate, and the air velocity is 0 to 3000 feet / minute at a temperature of 0 to 120 ° C. It has been proposed to form a film of a sulfonated polyarylether by ventilating (see Patent Document 2). Also proposed is to form a silica film by bringing silica sol into contact with the surface of the porous substrate, blowing air with a dew point of -70 to 0 ° C. to dry the silica sol, and then firing it. (See Patent Document 3).

Japanese Examined Patent Publication No. 6-98278 JP-A-63-248409 International Publication No. WO2011 / 118252

Microporous and Mesoporous Materials, 78 (2005) 235-243

  However, when forming a film containing metal ions on the surface of the porous substrate, a method of attaching and drying a raw material containing a liquid as in Patent Documents 2 and 3, the metal ions contained in the raw material are liquid At the same time, the metal ion concentration in the film may decrease due to diffusion to the porous substrate side. In this case, since the metal ion concentration in the film is low, the function of the film may not be sufficiently exhibited. For this reason, it has been desired to suppress a decrease in the metal ion concentration in the film.

  The present invention has been made to solve such problems. When a metal-containing film is produced on the surface of a porous substrate using a raw material containing metal ions and a liquid, the concentration of metal ions in the film is reduced. The main purpose is to provide a device capable of suppressing the above.

  The present invention adopts the following means in order to achieve the main object described above.

The method for producing a metal-containing film of the present invention includes:
Using a raw material containing metal ions and a liquid, forming a functional film containing the metal ions on the surface of the porous substrate,
Acceleration treatment for promoting drying of the functional film is performed from the film surface side of the functional film, and the liquid content in the functional film becomes 20% by mass before the drying in 1 to 4 hours after the start of the drying. And a drying step for drying the functional film.

  In this method for producing a metal-containing film, a functional film containing metal ions is formed using a raw material containing metal ions and a liquid, and drying is performed at a predetermined speed while performing an acceleration treatment for promoting drying from the film surface side of the functional film. I do. In this method for producing a metal-containing film, a decrease in the metal ion concentration in the film can be suppressed, and the variation in the metal ion concentration is small. The reason is presumed as follows. For example, since the drying speed is sufficiently high, it is possible to prevent the liquid containing metal ions from diffusing to the porous substrate during the drying, and as a result, it is possible to suppress the decrease in the metal ion concentration in the film. It is considered possible. Moreover, since the drying speed is not too high, uneven drying is difficult to occur, and as a result, it is considered that variation in metal ion concentration can be suppressed.

  In the method for producing a metal-containing film of the present invention, the promotion process may be a process of blowing air that flows substantially parallel to the film surface to the film surface. If it is the process which ventilates to a film surface, drying can be accelerated | stimulated comparatively easily.

  In the method for producing a metal-containing film of the present invention, the functional film may further include a supporting part capable of supporting the metal ions, and an inorganic skeleton and / or an organic skeleton bonded to the supporting part. In such a case, since the metal ions are supported on the support part, it is considered that the liquid containing the metal ions is less likely to diffuse to the porous substrate side, and that the stability of the metal ions is improved and the change can be suppressed. is there. In such a manufacturing method, in the forming step, a film skeleton including the supporting part capable of supporting the metal ions and the inorganic skeleton and / or the organic skeleton bonded to the supporting part is formed, and the film The functional film may be formed by bringing a metal ion introduction liquid containing the metal ions and the liquid into contact with a skeleton. By so doing, it is possible to relatively easily form a functional film that further includes a supporting portion and an inorganic skeleton and / or an organic skeleton bonded to the supporting portion.

  In the method for producing a metal-containing film of the present invention, the liquid before drying may include 60% by mass or more of water.

  In the method for producing a metal-containing film of the present invention, the porous base material is a structure including a porous partition wall part that forms one or more cells serving as a fluid flow path. The functional film may be formed on the inner surface of the part.

  In the method for producing a metal-containing film of the present invention, the metal ion may include one or more of gold, silver, copper, platinum, palladium, nickel, cobalt, iron, and an alkali metal as a metal species.

FIG. 3 is an explanatory diagram illustrating an example of a schematic configuration of a structure body. Explanatory drawing which shows the manufacturing method of the structure 10 notionally. The graph which shows the relationship between drying time and the moisture content in a film | membrane. The graph which shows the dispersion | variation in the in-film silver density | concentration of each Example.

  One embodiment of a method for producing a metal-containing film of the present invention will be described with reference to the drawings. In this embodiment, a structure including a metal-containing membrane that functions as a separation membrane and used as a membrane element that performs concentration / separation of a mixed fluid is manufactured. FIG. 1 is an explanatory diagram illustrating an example of a schematic configuration of the structure 10. FIG. 2 is an explanatory view conceptually showing the method for manufacturing the structure 10.

  First, the structure 10 will be described.

  As shown in FIG. 1, the structure 10 includes a porous partition wall portion 14 that forms a plurality of cells 12 that serve as a flow path for a mixed fluid, and a functional layer 16 provided on an inner surface 15 a of the partition wall portion 14. And a seal portion 18 provided on the end surface 15 b of the partition wall portion 14. In the structure 10, the functional layer 16 functions as a separation membrane that separates the mixed fluid. Specifically, among the mixed fluid that has entered the cell 12 from the inlet side, the fluid that can pass through the functional layer 16 is concentrated through the porous partition wall 14 in which the functional layer 16 is formed, and is used as the concentrated fluid. It is discharged from the outer peripheral surface of the structure 10. On the other hand, the fluid that cannot pass through the functional layer 16 flows along the flow path of the cell 12 and is discharged from the outlet side of the cell 12 as a separation fluid. Note that the mixed fluid may include two or more kinds of gases, or may include two or more kinds of liquids. Moreover, it is good also as what contains gas and a liquid, good also as what contains gas and solid (powder), good also as what contains liquid and solid, and contains gas, liquid, and solid. It may be a thing.

  The structure 10 has a monolith structure including a plurality of cells 12. Although the external shape is not particularly limited, it can be a cylindrical shape, an elliptical column shape, a quadrangular column shape, a hexagonal column shape, or the like.

  The cell 12 is a flow path extending in the axial direction of the structure 10, and may be a through-hole, or one end thereof may be plugged. Further, some of the cells 12 may be plugged at both ends, and the partition wall 14 may be formed with a slit communicating with the external space. In the case of a cell having both ends plugged and having a slit formed in the partition wall portion 14, the fluid that can pass through the functional layer 16 is efficiently discharged from the outer peripheral surface of the structure 10 through the slit. The cross-sectional shape of the cell 12 may be a polygonal shape such as a triangle, a quadrangle, a pentagon, a hexagon, or an octagon, a streamline shape such as a circle or an ellipse, or a combination thereof. Among these, it is preferable that it is 1 or more of the polygon more than a square, an ellipse, and a circle. This is because the sharp corners are not formed in the cell 12, so that the filter cake can be easily removed. The maximum length of the opening of the cell 12 may be, for example, not less than 0.5 mm and not more than 10 mm. Here, the maximum length of the opening of the cell 12 refers to the length between two points where the length becomes the maximum when two points on the periphery of the opening of the cell 12 are connected by a straight line.

  The partition wall 14 mainly serves as a base material that supports the functional layer 16 and is formed to be porous so as not to hinder the flow of fluid. The pore diameter may be appropriately determined in consideration of the balance between mechanical strength and filtration resistance, and can be, for example, about 0.001 μm to several hundred μm. The pore diameter indicates an average pore diameter, and may be measured by a measurement method suitable for the size (for example, gas adsorption method, mercury intrusion method, SEM observation, etc.). The thickness of the partition 14 between the adjacent cells 12 can be set to 1 mm or more and 5 mm or less, for example. Moreover, the thickness of the partition part 14 from the outermost periphery cell 12 to an outer peripheral surface can be 1 mm or more and 5 mm or less, for example. The partition wall 14 may include an organic material such as a resin, or may include an inorganic material. Examples of the inorganic material include one or more selected from cordierite, Si-bonded SiC, recrystallized SiC, aluminum titanate, mullite, silicon nitride, sialon, zirconium phosphate, zirconia, titania, alumina, and silica. It may be formed including an inorganic material. Of these, alumina and titania are preferred. This is because the raw material is easily available, the pore diameter of the partition wall 14 is relatively easy to control, and the corrosion resistance is high.

  The partition wall 14 may have a two-layer structure in which a fine particle portion 14b having a small pore diameter is formed on the surface of a coarse particle portion 14a having a large pore diameter. What is necessary is just to determine the pore diameter of the coarse-grained part 14a suitably considering the balance of mechanical strength, filtration resistance, etc., for example, it can be set as about 0.1 micrometer-several hundred micrometers. The pore diameter of the fine-grained portion 14b only needs to be smaller than the pore diameter of the coarse-grained portion 14a. For example, the pore diameter can be about 0.001 μm to 1 μm. In what has such a two-layer structure, since the pore diameter as a whole of the partition part 14 becomes large by providing the coarse-grained part 14a, filtration resistance can be reduced. On the other hand, by providing the fine grain part 14b, the surface of the partition part 14 becomes smooth and the functional layer 16 and the seal part 18 can be formed uniformly. Note that the material of the coarse portion 14a and the fine portion 14b may be the same or different. Further, the partition wall portion 14 may not have a two-layer structure. For example, the partition wall portion 14 has three or more layers including an intermediate layer having an intermediate pore diameter between the coarse particle portion 14a and the fine particle portion 14b. It may have a layer structure, may have a gradient material structure in which the pore diameter continuously changes, or may have a single layer structure.

  The functional layer 16 functions as a separation membrane that separates the mixed fluid to be processed. The functional layer 16 is provided on the inner surface 15a of the partition wall 14, and may be formed in a film shape or a particle layer shape, for example. This functional layer 16 contains metal ions. Although the kind of metal ion is not particularly limited, it is preferable that the metal ion contains gold, silver, copper, platinum, palladium, nickel, cobalt, iron, alkali metal, etc., and more preferably contains silver. This is because silver ions are particularly suitable for the separation of unsaturated hydrocarbons. The concentration of the metal ions is not particularly limited. However, when any five locations on the surface of the functional layer 16 are measured using a scanning electron microscope / energy dispersive X-ray analyzer, all of them are 7 Atoms. % Or more and 20 Atom% or less, or 8 Atom% or more and 16 Atom% or less. Further, the standard deviation of the concentration is preferably 0 or more and 3.0 or less, and more preferably 0.1 or more and 2.0 or less. The thickness of the functional layer 16 can be, for example, about 0.01 μm to several tens of μm. Note that the functional layer 16 may also be provided on the end surface 15 b of the partition wall portion 14.

  The functional layer 16 may have a film skeleton 16a such as an inorganic skeleton and / or an organic skeleton. Such a membrane skeleton 16a may be bonded to a supporting part capable of supporting metal ions, and the supporting part may support metal ions. Examples of the inorganic skeleton include a chain structure or a three-dimensional structure skeleton in which metal elements such as silicon, titanium, aluminum, and zirconium are bonded through oxygen or the like. Examples of the organic skeleton include known resins such as polystyrene, acrylic, epoxy, polyester, polyamide, polyimide, polyurethane, polysulfone, polyether, and polyethersulfone. Examples of the supporting part include cation exchange groups such as a carboxyl group, a sulfone group, a phosphoric acid group, a phosphonic acid group, and a phenolic hydroxyl group.

  The seal portion 18 is for preventing inflow and outflow of fluid from the end surface 15 b of the partition wall portion 14, and is provided on the end surface 15 b of the partition wall portion 14. As the material of the seal portion 18, for example, a dense material such as glass, ceramics, or resin can be used. The seal portion 18 may be formed by, for example, applying and drying slurry containing a raw material on the end surface 15b of the partition wall portion 14 and performing firing or curing treatment as necessary. The slurry containing the raw material may contain a solvent, an organic binder, and the like in addition to the raw material such as glass powder, ceramic powder, and resin powder. Moreover, it is good also as a precursor slurry containing the precursor of the seal part 18. FIG. The application method is not particularly limited, and for example, the above-described slurry may be impregnated in a sponge and applied by a stamp that presses the sponge against the inlet side or the outlet side of the partition wall portion 14. Moreover, you may apply | coat by the dipping which immerses the entrance side and exit side of the partition part 14 in the slurry mentioned above. Moreover, you may apply | coat by spray etc.

  Next, a method for manufacturing the structure 10 will be described. This manufacturing method may include a partition wall forming process for forming the partition wall 14, a forming process for forming the functional layer 16 on the inner surface 15 a of the partition wall 14, and a drying process for drying the functional layer 16. Good.

[Partition wall forming step]
In the partition wall forming step, the partition wall 14 having a predetermined shape is formed. Here, as an example, as shown in FIG. 1, the case where the partition wall portion 14 having a two-layer structure in which the fine grain portion 14b is formed on the surface of the coarse grain portion 14a will be described. The partition 14 having such a two-layer structure can be manufactured, for example, as follows. First, the coarse grain part 14a is formed. Specifically, in addition to aggregate particles and dispersion medium, if necessary, additives such as surfactants are mixed and kneaded to obtain a clay, and the clay is molded, dried and fired. Can be obtained by: The pore diameter can be controlled, for example, by adjusting the average particle diameter of the aggregate particles. Subsequently, a fine grain portion 14b is formed on the surface of the coarse grain portion 14a. Specifically, in addition to the aggregate particles and the dispersion medium, if necessary, a slurry is prepared by mixing an additive such as a surfactant, and the slurry is formed on the surface of the coarse portion 14a. It can be formed by drying and firing.

[Formation process]
In the forming step, the functional layer 16 can be formed on the inner surface 15a of the partition wall portion 14 using a raw material containing metal ions and liquid. The metal ion is not particularly limited, but it is preferable that the metal ion includes one or more of gold, silver, copper, platinum, palladium, nickel, cobalt, iron, and an alkali metal. The raw material containing a metal ion and a liquid may contain BF ₄ ⁻ , NO ₃ ⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , CFCO ₂ ^{− and the} like as anions paired with such metal ions. The kind of liquid is not particularly limited, and can include various organic solvents such as alcohol and water. Among these, it is preferable that it contains water, it is more preferable that it contains 60 mass% or more of water, and it is more preferable that it contains 80 mass% or more of water. The functional layer 16 formed in the forming step only needs to contain metal ions and liquid, but preferably further includes a film skeleton 16 a that is a skeleton of the functional layer 16.

  As a method for forming the functional layer 16, for example, as shown in FIG. 2, a film skeleton 16a is formed on the inner surface 15a of the partition wall portion 14 (see FIG. 2A), and a metal skeleton is formed on the formed film skeleton 16a. The functional layer 16 including the film skeleton 16a and the metal ion introduction liquid 16b may be formed by contacting the metal ion introduction liquid 16b which is a raw material containing ions and liquid (see FIG. 2B). The formation of the membrane skeleton 16a may be performed as follows, for example. First, a sol as a raw material for the film skeleton 16a is prepared. This sol can be prepared, for example, by hydrolyzing and polymerizing a metal alkoxide raw material having a cation exchange group, or by adding a metal alkoxide to a polymer solution containing a cation exchange group and hydrolyzing and polymerizing. The obtained sol is formed on the inner surface 15a of the partition wall 14, dried and fired. By repeating such formation, drying, and firing at least once, it is possible to form the membrane skeleton 16a having a cation exchange group that can bind to the organic-inorganic composite skeleton and bond to the metal ion. Subsequently, by performing ion exchange using the metal ion introduction liquid 16b containing the desired metal ion, the functional layer 16 in which the desired metal ion is supported on the support portion can be obtained. The metal ion introduction liquid 16b may include, for example, 80% by mass or more of liquid or 90% by mass or more of liquid. The time for contacting the metal ion introduction liquid 16b is preferably 1 hour or more and 100 hours or less. This is because, if it is 1 hour or more, it is considered that the metal ions are sufficiently supported on the support part, whereas it is considered that the amount of metal ions supported on the support part does not increase even if the support part is contacted for 100 hours or more. . The method of bringing the metal ion introduction liquid 16b into contact with the membrane skeleton 16a is not particularly limited, and a method in which the partition wall portion 14 is immersed in the metal ion introduction liquid 16b, or the cell 12 is filled with the metal ion introduction liquid 16b and held for a predetermined time. A publicly known method such as a method of performing, a method of flowing down the metal ion introduction liquid 16b in the cell 12 in a state where the axial direction of the cell 12 is aligned with the vertical direction, a method of spraying, or the like can be applied. In addition, when forming such a functional layer 16, you may form by preparing the partition part 14 in which the film | membrane frame | skeleton 16a was formed previously, and performing ion exchange using the metal ion introduction liquid 16b to it.

  As a method for forming the functional layer 16, in addition to the method described above, a mixed raw material liquid containing a film skeleton material, metal ions, and a liquid may be brought into contact with the inner surface 15 a of the partition wall portion 14. The method of bringing the mixed raw material liquid into contact with the inner surface 15a of the partition wall 14 can be the same as the method of bringing the metal ion introduction liquid 16b into contact with the film skeleton 16a.

[Drying process]
In the drying step, an acceleration process for promoting the drying of the functional layer 16 from the film surface 17 side of the functional layer 16 is performed, and the liquid content in the functional layer 16 is reduced to 20 before drying for 1 to 4 hours after the start of drying. Drying is performed so that the mass% is obtained. That is, the drying is performed under the condition that when it is 1 hour after the start of drying, it is 20% by mass or more before drying, and when 4 hours after the start of drying, it is 20% by mass or less before drying. Among these, from the viewpoint of suppressing a decrease in the metal concentration in the functional layer 16, the liquid content in the functional layer 16 should be 20% by mass before drying within 1 to 3 hours after the start of drying. It is more preferable to make it 20% by mass before drying during 1 to 2 hours. On the other hand, from the viewpoint of suppressing variation in the metal concentration in the functional layer 16, the liquid content in the functional layer 16 should be 20% by mass before drying within 2 to 4 hours after the start of drying. Preferably, it is more preferably 20% by mass before drying during 3 to 4 hours.

  Examples of the promoting process include a process of blowing air that flows substantially parallel to the film surface 17 of the functional layer 16 to the film surface 17 and drying it (see FIG. 2C). With such treatment, drying can be promoted relatively easily. When performing the process which blows the wind which flows into the film surface 17 to the film surface 17 as the acceleration | stimulation process to the film surface 17 of the functional layer 16, the wind speed is preferable 5.0 m / s or more, 6.0 m / s or more Is more preferable. Moreover, 10 m / s or less is preferable and 9.0 m / s or less is more preferable. This is because it is possible to perform suitable drying at room temperature under such blowing conditions. The wind temperature is preferably 10 ° C. or higher, for example. Drying is unlikely to be promoted with wind at a temperature lower than 10 ° C. For example, 80 degrees C or less is preferable. At temperatures higher than 80 ° C., cracks and the like may occur on the film surface. Of these, the air temperature may be, for example, 20 ° C. or higher, 25 ° C. or lower, or 30 ° C. or lower. The wind dew point is preferably lower than the blowing temperature, and may be, for example, −70 ° C. or higher or 70 ° C. or lower. In order to lower the dew point temperature, for example, moisture may be adsorbed by a dehumidification rotor having a honeycomb structure in which an adsorbent is strongly bonded. In addition to what was mentioned above as a promotion process, the method of reducing the dew point of the atmosphere by the side of the film surface 17 of the functional layer 16 without blowing is mentioned.

  The acceleration treatment is preferably performed from the start of drying until the liquid content in the functional layer 16 is 20% by mass or less before the start of drying, more preferably 10% by mass or less, and more preferably 1% by mass or less. It is more preferable to carry out until it becomes. By doing so, it is possible to more easily perform the drying so that the liquid content in the functional layer 16 becomes 20% by mass before the drying in 1 to 4 hours after the start of the drying.

  According to the manufacturing method of the structure 10 described above, it is possible to suppress a decrease in the metal ion concentration in the functional layer 16, and the variation in the metal ion concentration is small. The reason for this is not clear, but is presumed as follows. When natural drying is performed as shown in FIG. 2D, since the partition wall portion 14 is porous, a liquid containing metal ions tends to diffuse toward the partition wall portion 14 due to a capillary phenomenon or the like. On the other hand, in the manufacturing method of the embodiment, as shown in FIG. 2C, the blast drying is performed under a predetermined condition, but the liquid evaporates from the functional layer 16 side and the drying speed is sufficiently high. It is considered that the metal ion introduction liquid 16b can be prevented from diffusing to the partition wall 14 side, and as a result, the decrease in the metal ion concentration in the functional layer 16 can be suppressed. Further, since the drying speed is not too high, it is difficult to cause uneven drying, and as a result, it is considered that variation in the metal ion concentration in the functional layer 16 can be suppressed.

  In addition, since the structure 10 has a monolith shape having a plurality of cells 12, the area of the functional layer per unit volume is larger than that of a tubular shape having a single cell, so that the mixed fluid can be separated. Efficiency is good. Such a structure 10 can be used as a membrane element including a functional layer 16 as a separation membrane.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The partition wall part 14 of the present embodiment corresponds to the porous substrate of the present invention, and the functional layer 16 corresponds to the functional film. In this embodiment, an example of the method for producing the metal-containing film of the present invention is clarified by describing the method for producing the structure 10.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, the manufacturing method of the structure 10 includes the partition wall forming step. However, such a step may be omitted, for example, a porous substrate prepared in advance may be used. .

  For example, in the above-described embodiment, the monolithic structure 10 including the plurality of cells 12 is used as the porous substrate. However, the tubular structure including one cell may be used. Alternatively, a plate-like structure may be used.

  Below, the example which produced the structure 10 concretely is demonstrated as an Example.

[Examples 1-5, Comparative Examples 1-3]
1. Production of structure 10 (A) Production of partition wall portion 14 (A-1) Production of coarse particle portion 14a Alumina particles having an average particle diameter of 50 μm were used as aggregate particles, and an organic binder and water were added thereto. The kneaded material was obtained by kneading. Next, using a plunger extruder, the obtained kneaded material is extruded and formed with 55 cells having an outer diameter of 30 mmφ, a length of 160 mm, and a channel diameter of 2.5 mm. Got the body. And the obtained molded object was dried at 100 degreeC for 24 hours using a hot-air circulation type dryer, and the dried molded object was baked using the electric furnace, and the coarse grain part 14a was obtained. . The firing conditions were a temperature of 1500 ° C., a firing time of 1 hour, and a heating rate and a cooling rate of 100 ° C./hour.

(A-2) Application of slurry for forming fine-grained portion Alumina particles having an average particle diameter of about 10 μm were used as aggregate particles, and a dispersant was added to 30% by mass of alumina particles to prepare a slurry for forming fine-grained portions. And the slurry for fine grain part formation was applied to the surface of coarse grain part 14a. As a coating method, a multilayer filter manufacturing method (excluding firing) described in Japanese Patent Publication No. 63-66566 was used.

(A-3) Firing Firing was performed in an electric furnace in an air atmosphere to form fine-grained portions 14b. The firing conditions were 1200 ° C. and 1 hour, and the rate of temperature increase and the rate of temperature decrease was 100 ° C./hour. In this way, the partition part 14 which has the coarse grain part 14a and the fine grain part 14b was obtained. In addition, since the fine grain part 14b is formed as an extremely thin layer of about 250 μm, it does not affect the maximum length of the opening of the cell 12 (diameter of the flow path).

(A-4) Formation of Seal Part 18 As a material of the seal part 18, 2 parts by mass of methyl cellulose as an organic binder is added to 100 parts by mass of glass powder having an average particle diameter of 10 μm, and water is further added and mixed. Thus, a slurry for forming a seal part was prepared. Then, the seal portion forming slurry was uniformly contained in the sponge, and applied to the end surface 15 b of the partition wall portion 14 by pressing the sponge. Thereafter, firing was performed in an electric furnace in an air atmosphere to form the seal portion 18. The firing conditions were 1000 ° C. for 1 hour, and the temperature increase rate and temperature decrease rate were 100 ° C./hour. Thus, the seal portion 18 was formed on the inner surface end portion 15a of the partition wall portion 14.

(B) Formation of membrane skeleton 16a (B-1) Preparation of sol 1 g of nitric acid was added to 8 g of an aqueous solution containing 25% by mass of carboxyethylsilanetriol sodium salt, and then heated at 60 ° C. for 6 hours in a water bath. By performing the treatment, hydrolysis and polymerization proceeded.

(B-2) Formation Using the obtained sol, formation was performed according to an example of JP 2012-40549 A. Specifically, first, the outer peripheral surface of the partition wall portion 14 on which the seal portion 18 was formed was masked with a masking tape. Next, the partition 14 was fixed to the falling film forming apparatus. Then, the produced sol was stored in the tank of the falling film forming apparatus, and the sol was poured from above and passed through the cell 12. Thereafter, wind at a wind speed of 5 m / s was sent from above to remove excess sol.

(B-3) Drying Further, drying was performed according to the examples of JP2012-40549A. Specifically, the inside of the cell 12 of the partition wall part 14 into which the sol was poured and the sol was adhered was dried for 30 minutes by passing air at room temperature using a dehumidifying blower within 30 seconds. The wind speed was 5 to 20 m / s, and the wind dew point was −70 to 0 ° C.

(B-4) Firing Firing was performed by holding at 150 ° C. for 2 hours in an electric furnace in an air atmosphere.

  The formation, drying and firing of the above (B-2) to (B-4) were repeated a total of 6 times to form the film skeleton 16a on the inner surface 15 of the partition wall portion 14.

(C) Introduction of metal ions (C-1) Ion exchange The outer peripheral surface of the partition wall 14 was masked with a masking tape. Next, using a liquid feed pump, 0.5 mol / L of AgBF ₄ aqueous solution (metal ion introduction liquid 16b) is fed from the lower part (inlet side or outlet side) of the partition wall 14 and the upper end of the cell 12 (outlet). Side or inlet side) and left in that state for 24 hours. Thereafter, the AgBF ₄ aqueous solution was discharged from the lower part of the partition wall 14 with a liquid feed pump.

(C-2) Drying Drying was performed following the drying of (B-3). The drying conditions at this time were the conditions shown in Table 1.

2. Evaluation of In-Membrane Water Content (Liquid Content) First, the in-membrane water content WF0 (g) after ion exchange and before drying and the in-membrane water content WFT (g) after the elapse of T time after the start of drying are expressed by the following formula ( 1) Obtained by (2).
WF0 = W0-WE (1)
WFT = WT-WE (2)
W0: mass after ion exchange and before drying, WT: mass after drying for T hours after ion exchange, and WE: mass after heat treatment at 80 ° C. for 50 hours to remove all moisture.

Subsequently, an in-film moisture content WF (mass%) indicating a ratio of the in-film water content after drying for T hours after film formation to the in-film water content before drying was determined by the following formula (3).
WF = (WFT / WF0) × 100 (3)

3. Evaluation of Silver Concentration The silver atom concentration on the surface of the functional layer 16 was measured using a scanning electron microscope / energy dispersive X-ray analyzer. The measurement was carried out at 5 times at 5 locations selected at random, and the average value and standard deviation were obtained.

4). Experimental results Table 1 shows the evaluation results of the silver concentration. FIG. 3 is a graph showing the relationship between the drying time and the moisture content in the film, and FIG. 4 is a graph showing the variation in the silver concentration in the film of each example.

  From Table 1 and FIG. 3, when the drying conditions other than the wind speed are approximately the same, the lower the rate of moisture content in the membrane, the faster the rate of decrease in moisture content in the membrane, the faster the wind speed. It was found that the average value of the in-film silver concentration after drying was higher.

  Further, according to Table 1, in Example 5 in which the moisture content in the film was blown and dried until it reached 20% by mass, and then the ventilation was stopped and the film was naturally dried in the air, the average value of the in-film silver concentration after drying was it was high. On the other hand, in Comparative Example 3, which was blown and dried until the moisture content in the film reached 30% by mass, then stopped and then naturally dried in the atmosphere, the average value of the in-film silver concentration after drying was low. From this, it was found that it is preferable to perform the acceleration treatment until the moisture content in the membrane becomes 20% by mass or less.

  Further, according to Table 1 and FIG. 4, in Comparative Example 1, the moisture content in the film was rapidly decreased and the average value of the silver concentration in the film after drying was high, but the variation in the silver concentration for each measurement site was different. It was big. This was presumed to be due to the non-uniform drying when drying was too fast. From this, it was found that it was necessary to perform drying at such a speed that the moisture content in the film in the functional layer 16 became 20% by mass before drying after lapse of 1 hour or more after the start of drying.

  Moreover, according to Table 1 and FIG. 4, in the comparative example 2, the fall of the moisture content in a film | membrane was slow, and the average value of the silver concentration in a film | membrane after drying was low. This was presumably because the silver ion-containing aqueous solution was dried from the outer peripheral surface of the partition wall 14 or the silver ions were transferred from the inside of the film to the base material. From this, it was found that the moisture content in the film in the functional layer 16 needs to be dried at such a speed that it becomes 20% by mass after drying 4 hours after the start of drying.

  The present invention can be used in, for example, a technical field that performs concentration, separation, purification, and the like of fluids.

  DESCRIPTION OF SYMBOLS 10 Structure, 12 cell, 14 Partition part, 14a Coarse grain part, 14b Fine grain part, 15a Inner surface, 15b End surface, 16 Functional layer, 16a Film | membrane frame | skeleton, 16b Metal ion introduction liquid, 17 Film surface, 18 Seal part.

Claims (10)

A method for producing a metal-containing membrane for concentrating and / or separating a mixed fluid,
Using a raw material containing metal ions and a liquid, forming a functional film containing the metal ions on the surface of the porous substrate,
Acceleration treatment for promoting drying of the functional film is performed from the film surface side of the functional film, and the liquid content in the functional film becomes 20% by mass before the drying in 1 to 4 hours after the start of the drying. A drying step of drying the functional film as follows:
The manufacturing method of the metal containing film | membrane containing this.   The method for producing a metal-containing film according to claim 1, wherein the promotion process is a process of blowing air that flows parallel to the film surface to the film surface. The functional film further includes a supporting part capable of supporting the metal ions, and an inorganic skeleton and / or an organic skeleton bonded to the supporting part.
The manufacturing method of the metal containing film | membrane of Claim 1 or 2. In the forming step, a film skeleton including the supporting part capable of supporting the metal ions and the inorganic skeleton and / or the organic skeleton bonded to the supporting part is formed, and the metal ions are formed on the film skeleton. And forming the functional film by contacting a metal ion introduction liquid containing the liquid.
The manufacturing method of the metal containing film | membrane of Claim 3.   The said liquid before the said drying is a manufacturing method of the metal containing film | membrane of any one of Claims 1-4 containing 60 mass% or more of water. The porous substrate is a structure including a porous partition wall forming one or more cells that serve as a fluid flow path,
Forming the functional film on the inner surface of the partition wall in the forming step;
The manufacturing method of the metal containing film | membrane of any one of Claims 1-5.   The metal content according to any one of claims 1 to 6, wherein the metal ion includes at least one of gold, silver, copper, platinum, palladium, nickel, cobalt, iron, and an alkali metal as a metal species. A method for producing a membrane.   The method for producing a metal-containing film according to claim 1, wherein the functional film is dried at 80 ° C. or less in the drying step.   In the said drying process, the manufacturing method of the metal containing film | membrane of any one of Claims 1-8 which ventilates on conditions whose wind dew point is -70 degreeC or more and 70 degrees C or less.   The method for producing a metal-containing film according to any one of claims 1 to 9, wherein the functional film has a film skeleton in which one or more metal elements of silicon, titanium, aluminum, and zirconium are bonded via oxygen. .