JP6155143B2 - Organic-inorganic hybrid porous membrane and method for producing the same - Google Patents

Description

  The present invention relates to an organic / inorganic hybrid porous membrane having ion conductivity, wherein the surface of an organic polymer porous membrane is coated with inorganic layered double hydroxide particles composed of two or more kinds of metal ions having different valences. And a manufacturing method thereof.

  For example, as shown in Patent Document 1 and Patent Document 2, in an electrolyte membrane for a fuel cell, for example, an organic polymer porous membrane is used as a base material (frame) in order to give strength necessary for handling the electrolyte membrane. The electrolyte membrane for a fuel cell is produced by filling the pores of the polymer porous membrane with an ion exchange polymer that is an ion conductive polymer of proton.

JP 2007-165204 A JP 2006-63095 A International Publication No. 2010/109670

  By the way, in the electrolyte membrane using the polymer porous membrane as described above as the base material, the polymer porous membrane itself has no ionic conductivity, so that the ionic conductivity of the electrolyte membrane produced using the polymer membrane is relatively low. There was a problem.

On the other hand, for example, Patent Document 3 proposes that an electrolyte membrane of a fuel cell is produced using an inorganic layered double hydroxide without using the above-described polymer porous membrane. . Since such an electrolyte membrane is composed of a layered double hydroxide, which is an ion conductive material, the ionic conductivity of the electrolyte membrane is such that the polymer porous membrane is used as a base material for the electrolyte membrane. Compared to higher. However, since the electrolyte membrane composed of the layered double hydroxide as described above is not flexible, there is a problem that the mechanical strength is insufficient, for example, when the electrolyte membrane is manufactured. In addition, the layered double hydroxide includes, for example, a basic layer [M 2 ⁺ _1−x M ³⁺ _x (OH) ₂ ] ^{x +} and an intermediate layer [A ⁿ⁻ _{x / n} · yH ₂ O] ^x− in a layered form. It is those that are stacked, represented by a common formula _{^{[M 2+ 1-x M 3+}} x (OH) 2] x + [A n- x / n · yH 2 O] x-. ^{Here, M 2+} is a divalent metal ^{ion, M 3+} is a trivalent metal ^{ion, A n-represents} a monovalent or divalent anion, x is 0.1 to 0.8 Indicates a number within range, y is a real number.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is an organic-inorganic hybrid porous material used for producing an electrolyte membrane having relatively high ion conductivity and mechanical strength. It is to provide a film and a method for manufacturing the same.

  As a result of various analyzes and examinations, the present inventor has reached the facts shown below. That is, when the surface of the organic polymer porous membrane is coated with a layered double hydroxide having anion conductivity, the layered double hydroxide is coated on the surface of the polymer porous membrane, ie, the organic / inorganic hybrid porous membrane itself. We have found the surprising fact that anion conductivity occurs substantially. The present invention has been made based on such findings.

The gist of the organic-inorganic hybrid porous membrane of the present invention for achieving the above object is an organic-inorganic hybrid porous membrane used as a base material for an electrolyte membrane of a fuel cell, which is an organic polymer porous membrane Is coated with inorganic layered double hydroxide particles composed of two or more kinds of metal ions having different valences , and the layered double hydroxide particles are scaly particles, and the metal ions A layered structure of a plurality of basic layers surrounded by and an intermediate layer composed of anions and water molecules existing between the layers is regularly stacked between the plurality of basic layers. The organic-inorganic hybrid porous membrane having ion conductivity.

According to the organic-inorganic hybrid porous membrane of the present invention, the surface of the organic polymer porous membrane is coated with inorganic layered double hydroxide particles composed of two or more kinds of metal ions having different valences, The double hydroxide particles are scaly particles, and are composed of a plurality of basic layers surrounded by the metal ions and anions and water molecules present between the plurality of basic layers. Since the organic-inorganic hybrid porous membrane itself has ionic conductivity due to the layered structure with the intermediate layer being regularly stacked , for example, the organic-inorganic hybrid porous membrane is used as the base material of the electrolyte membrane. When used as an electrolyte membrane, the ionic conductivity of the electrolyte membrane is higher than when a porous polymer membrane without ionic conductivity is used. Moreover, the strength of the electrolyte membrane can be improved by using the organic-inorganic hybrid porous membrane as a base material for the electrolyte membrane. That is, an electrolyte membrane having relatively high ionic conductivity and mechanical strength can be produced by using the organic-inorganic hybrid porous membrane.

  Here, preferably, an electrolyte membrane for an anion exchange membrane fuel cell is produced by filling the pores of the organic-inorganic hybrid porous membrane with an ion conductive polymer using the organic-inorganic hybrid porous membrane. The For this reason, the ion conductivity and mechanical strength of the electrolyte membrane for the anion exchange membrane fuel cell are preferably improved.

Further, the gist of the invention relating to the method for producing the organic-inorganic hybrid porous membrane is as follows: (a) The surface of the organic polymer porous membrane is an inorganic layered layer composed of two or more kinds of metal ions having different valences. a manufacturing method of an organic-inorganic hybrid porous membrane having ion conductivity coated with particles of double hydroxides, and the solution preparation step of preparing a solution which is dissolved (b) a plurality of metal salts, (c ) and precipitation step of precipitating the small pieces of the layered double hydroxide in the polymeric porous membrane was placed surface of the polymeric porous membrane in the solution, Ru Kotonia containing.

  According to the method for producing an organic-inorganic hybrid porous membrane, a solution in which a plurality of metal salts are dissolved is prepared in the solution preparation step, and the polymer porous membrane is placed in the solution in the precipitation step. An organic / inorganic hybrid porous membrane having ion conductivity in which the surface of the polymer porous membrane is coated with particles of the layered double hydroxide by depositing small pieces of the layered double hydroxide on the surface of the porous membrane By using the organic-inorganic hybrid porous membrane as a base material for an electrolyte membrane, for example, an electrolyte membrane having relatively high ionic conductivity and strength can be produced.

  Preferably, the polymer porous membrane is a polyvinylidene fluoride membrane having an average pore diameter of 2 μm and a porosity of about 86%.

It is sectional drawing which shows typically the structure of a fuel cell provided with the electrolyte membrane in which the organic-inorganic hybrid porous membrane of one Example of this invention was used as a base material. It is a figure which shows the surface of the organic inorganic hybrid porous membrane used for the electrolyte membrane of FIG. It is sectional drawing which shows typically the structure of the layered double hydroxide coated on the surface of the polymer porous membrane in the organic-inorganic hybrid porous membrane of FIG. It is process drawing explaining the manufacturing process of the organic inorganic hybrid porous membrane of FIG. It is a figure which shows manufacturing conditions, such as an organic inorganic hybrid porous membrane of the Example goods 1 thru | or Example goods 4 manufactured by the manufacturing process shown in FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of the comparative example product 1 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of the comparative example product 2 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of the comparative example goods 3 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic inorganic hybrid porous membrane of the comparative example goods 4 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 3 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 4 shown in FIG. It is a figure which shows the FESEM photograph which expanded the FESEM photograph of FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows atomic ratio (At.%) Of element Mg and Al contained in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows distribution of Mg element which exists in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows distribution of Al element which exists in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows the intensity | strength (count number) of the some element which exists in the organic-inorganic hybrid porous membrane of Example goods 1 shown in FIG. It is a figure which shows the FESEM photograph of the surface in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. It is a figure which shows atomic ratio (At.%) Of element Mg and Al contained in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. It is a figure which shows distribution of Mg element which exists in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. It is a figure which shows distribution of Al element which exists in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. It is a figure which shows the intensity | strength (count number) of the some element which exists in the organic-inorganic hybrid porous membrane of Example goods 2 shown in FIG. In the organic-inorganic hybrid porous membrane of Example Product 1, the organic-inorganic hybrid porous membrane of Example Product 2, the organic-inorganic hybrid porous membrane of Comparative Product 1, and the layered double hydroxide shown in FIG. It is a figure which shows a line diffraction pattern. In the organic-inorganic hybrid porous membrane of Example product 1 and the organic-inorganic hybrid porous membrane of Example product 2 shown in FIG. 5, a measurement method for measuring the ionic conductivity of these organic-inorganic hybrid porous membranes is schematically shown. FIG. FIG. 6 is a diagram showing the ionic conductivity of the organic-inorganic hybrid porous membrane in the organic-inorganic hybrid porous membrane of Example Product 1 and the organic-inorganic hybrid porous membrane of Example Product 2 shown in FIG. 5.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

FIG. 1 is a cross-sectional view schematically showing a configuration of a fuel cell 14 including an electrolyte membrane 12 in which an organic-inorganic hybrid porous membrane 10 (see FIG. 2) according to an embodiment of the present invention is used as a base material. As shown in FIG. 1, the fuel cell 14 is composed of a carbon cloth in which, for example, a catalyst-carrying carbon carrying platinum, a transition metal, or the like is supported on the entire surface of the electrolyte membrane 12, and is an anode having conductivity and gas permeability ( The fuel electrode 16 and the cathode 18 are opposed to each other with the electrolyte membrane 12 interposed therebetween. The fuel cell 14 includes a fuel chamber 20 on the side of the anode 16 not in contact with the electrolyte membrane 12 and an oxidant gas chamber 22 on the side of the cathode 18 not in contact with the electrolyte membrane 12. For example, hydrogen gas (H ₂ ) or the like is supplied to the fuel chamber 20, and gas (air) containing oxygen (O ₂ ) or the like is supplied to the oxidant gas chamber 22, for example.

In the fuel cell 14 configured as described above, when a current is applied to the fuel cell 14, oxygen in the oxygen-containing gas and water (H ₂ O) undergo a reduction reaction at the cathode 18 to generate hydroxide ions (OH ⁻ ) Is generated, and the generated hydroxide ions are supplied from the cathode 18 to the anode 16 through the electrolyte membrane 12. Then, at the anode 14, hydroxide ions (OH ⁻ ) react with the fuel to generate water and release electrons (e ⁻ ) to generate power. In the fuel cell 14, hydroxide ions (OH ⁻ ) generated by the reduction reaction at the cathode 18 move to the anode 16 through the anion exchange membrane (alkaline electrolyte membrane) that is the electrolyte membrane 12, and It is an anion exchange membrane type fuel cell which generates electric power by oxidation-reduction reaction.

FIG. 2 is a conceptual diagram showing the surface of the organic-inorganic hybrid porous membrane 10 included in the electrolyte membrane 12 as its base material (aggregate). As shown in FIG. 2, the organic-inorganic hybrid porous membrane 10 is relatively high in, for example, a PVDF (Poly Vinylidene DiFluoride) membrane by forming continuous pores by entanglement of fibrous polymers. On the surface of the porous organic polymer membrane 24 having gas permeability, an inorganic substance composed of a divalent metal ion such as magnesium ion (Mg ²⁺ ) and a trivalent metal ion such as aluminum ion (Al ³⁺ ) is used. Layered double hydroxide LDH particles are coated. The PVDF membrane has an average pore diameter of about 50 nm to 5 μm and a porosity of about 30 to 90%. Further, the electrolyte membrane 12 of the fuel cell 14 is an aroma having an anion conducting polymer such as a chloromethyl (CM) group and a quaternary ammonium group (QA) on the chain in the pores 10a of the organic-inorganic hybrid porous membrane 10. It is produced by filling a group anion exchange polymer, a non-crosslinked block copolymer having an aromatic ring, or the like. Further, as a method for filling the pores 10a of the organic / inorganic hybrid porous membrane 10 with the anion conducting polymer, for example, the organic / inorganic hybrid porous membrane 10 is immersed in an electrolyte monomer solution and evacuated to obtain pores 10a. There is a method in which the electrolyte monomer solution is impregnated inside, and then the monomer of the electrolyte monomer solution is polymerized.

FIG. 3 is a diagram schematically showing the structure of the layered double hydroxide LDH coated on the surface of the polymer porous membrane 24 in the organic-inorganic hybrid porous membrane 10. As shown in FIG. 3, the layered double hydroxide LDH is composed of randomly present divalent or trivalent metal ions such as magnesium ions (Mg ²⁺ ), aluminum ions (Al ³⁺ ) and the like. ^-) and the base layer 26 of a plurality of layers surrounded by consist water molecules present example the carbonate ion (CO 3 ^_2-) not anionic 28 and shown such interlayer between the base layer 26 of the plurality layers The intermediate layer 30 is configured. In the inorganic layered double hydroxide LDH of this example, the layered structure of the basic layer 26 and the intermediate layer 30 is regularly stacked. For example, the basic layer 26 is [Mg ²⁺ _1-x Al ³⁺ _x (OH) ₂ ] ^{x +} , and the intermediate layer 30 is represented by [CO ₃ ²⁻ _x · yH ₂ O] ^x− .

FIG. 4 is a process diagram for explaining the manufacturing processes SA1 to SA4 of the organic-inorganic hybrid porous membrane 10 described above. As shown in FIG. 4, first, in the solution preparation step SA1, for example, 0.030 mol of magnesium nitrate hexahydrate (Mg (NO ₃ ) ₂ .6H ₂ O) and aluminum nitrate nonahydrate (Al (NO _{3) 3} · 9H ₂ O), for example, 0.015 mol, urea _{(urea, CO (NH 2)} 2) , for example, by dissolving and 0.420mol in purified water, a plurality of metal salts such as magnesium nitrate and aluminum nitrate A dissolved solution is made. In the above solution, the molar ratio of urea and nitric acid, that is, Urea / [NO ₃ ] is 4.0.

  Next, in the precipitation step SA2, the solution obtained in the solution preparation step SA1 is transferred to a poly-tetra-fluoro-ethylene container, and the polymer porous membrane 24 having a relatively high hydrophobicity in the solution in the container, for example, A PVDF membrane or the like is placed, the container is sealed, placed in an oven, and held at, for example, 95 ° C. for 12 hours. As a result, a small piece of layered double hydroxide LDH is deposited on the surface of the polymer porous membrane 24 in the solution. Since the PVDF membrane, which is the polymer porous membrane 24 used in the deposition step SA2, has a relatively high hydrophobicity, for example, when the above solution does not penetrate the PVDF membrane, the PVDF membrane is wetted with, for example, ethanol. Into the above solution. In addition, the said PVDF membrane is produced on the conditions shown in the following Table 1, for example, The electrospinning method which spins by applying a high voltage to the polymer solution in which the polymer (PVDF) was melt | dissolved in the solvent The fibers obtained by the above are laminated in a film shape as shown in FIG. 2, for example.

[Table 1]
・ Polymer solution polymer: PVDF (Kureha Corporation, KF Polymer W # 1100)
Solvent: Acetone (acetone) / DMF (N, N-dimethylformamide) Weight ratio 3: 7
Concentration: 20 wt. %

・ Electrospinning condition equipment: NANON (MEC Co., Ltd.)
Voltage: 20kV
Flow rate: 1ml / hr
Nozzle: 27G (Terumo needle)
Distance (nozzle to collector): 15cm
Film thickness: 5-20 μm

  Next, in the cleaning step SA3, the polymer porous membrane 24, that is, the organic / inorganic hybrid porous membrane 10 whose surface is coated with the particles of the layered double hydroxide LDH in the precipitation step SA2, is washed with purified water. Next, in the drying step SA4, the organic-inorganic hybrid porous membrane 10 washed in the washing step SA3 is dried at, for example, 80 degrees. Thereby, the organic-inorganic hybrid porous membrane 10 is obtained.

[Experiment I]
Here, Experiment I conducted by the present inventors will be described. The experiment I is an experiment for verifying that the surface of the polymer porous film 24 is coated with the layered double hydroxide LDH particles by the above-described precipitation step SA2.

  In this experiment I, first, the organic-inorganic hybrid porous membrane 10 of Examples 1 to 4 shown in FIG. 5 was manufactured through the solution preparation process SA1 to the drying process SA4. Then, in the manufactured organic-inorganic hybrid porous membrane 10 of Examples 1 to 4, whether or not particles were deposited on the surface of the PVDF membrane as the polymer porous membrane 24 was determined by FE-SEM (field emission type). The determination was made using a FESEM photograph obtained by a scanning electron microscope (Field Emission Scanning Electron Microscope). Further, it was determined by EDX (energy dispersive X-ray spectroscopy) and X-ray diffraction whether the particles deposited on the surface of the PVDF film were layered double hydroxide LDH. As shown in FIG. 5, the organic-inorganic hybrid porous membrane 10 of Example Product 1 is manufactured through the above-described solution preparation process SA1 to drying process SA4. Moreover, the organic-inorganic hybrid porous membrane 10 of Example Product 2 is different from the organic-inorganic hybrid porous membrane 10 of Example Product 1 in that the heat retention time was changed from 12 hours to 24 hours in the deposition step SA2. Otherwise, it was manufactured in the same manner as the organic-inorganic hybrid porous membrane 10 of Example Product 1. Further, the organic-inorganic hybrid porous membrane 10 of Example Product 3 is different from the organic-inorganic hybrid porous membrane 10 of Example Product 1 in that the heat retention time was changed from 12 hours to 48 hours in the deposition step SA2. Otherwise, it was manufactured in the same manner as the organic-inorganic hybrid porous membrane 10 of Example Product 1. In addition, the organic-inorganic hybrid porous membrane 10 of Example Product 4 is different from the organic-inorganic hybrid porous membrane 10 of Example Product 1 in that the heat retention temperature was changed from 95 ° C. to 120 ° C. in the precipitation step SA2. Otherwise, it was manufactured in the same manner as the organic-inorganic hybrid porous membrane 10 of Example Product 1.

Furthermore, in Experiment I, the organic-inorganic hybrid porous membrane 10 of Comparative Example Product 1 to Comparative Example Product 4 shown in FIG. 5 was manufactured, and the manufactured Comparative Example Product 1 to Comparative Example Product 4 were similar to the above. In the organic-inorganic hybrid porous membrane 10, whether or not particles were deposited on the surface of the PVDF membrane, which is the polymer porous membrane 24, was determined using a FESEM photograph by FE-SEM. As shown in FIG. 5, the organic-inorganic hybrid porous membrane 10 of the comparative product 1 is the polymer porous membrane 24, that is, the PVDF membrane before being processed in the above-described deposition step SA2. Further, the organic-inorganic hybrid porous membrane 10 of the comparative example product 2 has urea (Urea) dissolved in the solution prepared in the solution preparation step SA1 with respect to the organic-inorganic hybrid porous membrane 10 of the example product 1 described above. It differs from 0.420 mol to 0.210 mol, that is, the molar ratio of Urea / [NO ₃ ] in the above solution is changed from 4.0 to 2.0. It is manufactured in the same manner as the membrane 10. Further, the organic-inorganic hybrid porous membrane 10 of the comparative example product 3 has urea (Urea) dissolved in the solution prepared in the solution preparation step SA1 with respect to the organic-inorganic hybrid porous membrane 10 of the example product 1 described above. It differs from 0.420 mol to 0.315 mol, that is, the mole ratio of Urea / [NO ₃ ] in the above solution is changed from 4.0 to 3.0. It is manufactured in the same manner as the membrane 10. Moreover, the organic-inorganic hybrid porous membrane 10 of the comparative example product 4 is different from the organic-inorganic hybrid porous membrane 10 of the example product 1 in that the heat retention time was changed from 12 hours to 6 hours in the deposition step SA2. Otherwise, it was manufactured in the same manner as the organic-inorganic hybrid porous membrane 10 of Example Product 1.

  Hereinafter, the results of Experiment I will be described with reference to FIGS. As shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the comparative example product 1 in FIGS. 6 and 7, that is, the polymer porous membrane 24, the surface of the fiber was smooth in the PVDF membrane before the treatment of the deposition step SA2. . Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the comparative example product 2 in FIGS. 8 and 9, the surface of the organic-inorganic hybrid porous membrane 10 of the comparative example product 2 is shown in FIG. 6 and FIG. In the organic-inorganic hybrid porous membrane 10 of Comparative Example Product 2, the layered double hydroxide LDH particles did not precipitate on the surface of the polymer porous membrane 24. Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the comparative example product 3 in FIGS. 10 and 11, the surface of the organic-inorganic hybrid porous membrane 10 of the comparative example product 3 is shown in FIGS. In the organic-inorganic hybrid porous membrane 10 of Comparative Example Product 3, the layered double hydroxide LDH particles did not precipitate on the surface of the polymer porous membrane 24. Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the comparative example product 4 in FIGS. 12 and 13, the surface of the organic-inorganic hybrid porous membrane 10 of the comparative example product 4 is shown in FIGS. 6 and 7. In the organic-inorganic hybrid porous membrane 10 of Comparative Example Product 4, the layered double hydroxide LDH particles were not deposited on the surface of the polymer porous membrane 24.

  Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the example product 1 of FIGS. 14 and 15, the surface of the organic-inorganic hybrid porous membrane 10 of the example product 1 is shown in FIGS. Compared with the PVDF membrane before the deposition step SA2 treatment shown in FIG. 2, scale-like (small piece-like) particles were deposited almost uniformly. Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the example product 2 in FIGS. 16 and 17, the surface of the organic-inorganic hybrid porous membrane 10 of the example product 2 is shown in FIGS. 6 and 7. In comparison with the PVDF film before the deposition step SA2 shown in FIG. 2, the scaly particles were deposited substantially uniformly. The scale-like particles deposited on the organic-inorganic hybrid porous membrane 10 of Example Product 1 are smaller than the scale-like particles deposited on the organic-inorganic hybrid porous membrane 10 of Example Product 2. Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the example product 3 of FIGS. 18 and 19, the surface of the organic-inorganic hybrid porous membrane 10 of the example product 3 is shown in FIGS. In comparison with the PVDF film before the deposition step SA2 shown in FIG. 2, the scaly particles were deposited substantially uniformly. Moreover, as shown in the FESEM photograph of the organic-inorganic hybrid porous membrane 10 of the example product 4 in FIGS. 20 and 21, the surface of the organic-inorganic hybrid porous membrane 10 of the example product 4 is shown in FIGS. 6 and 7. In comparison with the PVDF film before the deposition step SA2 shown in FIG. 2, the scaly particles were deposited substantially uniformly.

  22 and FIG. 27 are diagrams showing FESEM photographs of the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2. FIG. 23 and 28 show the elements Mg and Al contained in the organic-inorganic hybrid porous film 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 shown in FIGS. It is a figure which shows atomic ratio (At.%) Of this. 24 and 29 show the distribution of Mg elements present in the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 shown in FIGS. FIG. 25 and 30 show the distribution of Al elements present in the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 shown in FIGS. FIG. 26 and 31 show the strengths of a plurality of elements existing in the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 shown in FIGS. FIG. 23 to FIG. 26, FIG. 28 to FIG. 31 show the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 shown in FIG. Elemental analysis and composition analysis are performed by (energy dispersive X-ray spectroscopy).

  As shown in FIGS. 22 to 26, in the organic-inorganic hybrid porous membrane 10 of Example Product 1, the main components of the scaly particles deposited on the surface of the polymer porous membrane 24 that is a PVDF membrane are layered. It was found to be Mg and Al contained in the double hydroxide LDH. Further, as shown in FIGS. 24 and 25, in the organic-inorganic hybrid porous membrane 10 of Example Product 1, two kinds of elements of Mg and Al are uniformly dispersed throughout the fiber of the PVDF membrane. Observed. In addition, as shown in FIGS. 27 to 31, in the organic-inorganic hybrid porous film 10 of Example Product 2, the main components of the scaly particles deposited on the surface of the polymer porous film 24 that is a PVDF film are as follows. It was found to be Mg and Al contained in the layered double hydroxide LDH. Further, as shown in FIGS. 29 and 30, in the organic-inorganic hybrid porous membrane 10 of Example Product 2, two kinds of elements of Mg and Al are uniformly dispersed throughout the fiber of the PVDF membrane. Observed.

  As shown in FIG. 32, the XRD pattern of the PVDF film in which the precipitation step SA2 of the comparative example product 1 is not performed has two diffraction peaks observed at around 20 degrees, and the XRD pattern of the layered double hydroxide LDH. Have diffraction peaks observed at around 10 degrees, around 24 degrees, around 35 degrees, around 40 degrees, and around 48 degrees. In addition, the XRD pattern of the organic-inorganic hybrid porous membrane 10 of Example Product 1 shows diffraction peaks at around 10 degrees, around 2 degrees, around 24 degrees, around 35 degrees, around 40 degrees, and around 48 degrees. In addition to the diffraction peak derived from the PVDF film, a diffraction peak attributed to the layered double hydroxide LDH was observed. Therefore, in the organic-inorganic hybrid porous membrane 10 of Example Product 1, the scale-like particles uniformly grown on the surface of the PVDF membrane fiber, which is the polymer porous membrane 24, are particles composed of layered double hydroxide LDH. It turns out that. Further, the XRD pattern of the organic-inorganic hybrid porous membrane 10 of Example Product 2 is similar to that of the organic-inorganic hybrid porous membrane 10 of Example Product 1 at around 10 degrees, two locations around 20 degrees, around 24 degrees, Diffraction peaks were observed at around 35 degrees, around 40 degrees, and around 48 degrees. In addition to the diffraction peaks derived from the PVDF film, diffraction peaks attributed to the layered double hydroxide LDH were observed. Therefore, in the organic-inorganic hybrid porous membrane 10 of Example Product 2, the scale-like particles uniformly grown on the surface of the PVDF membrane fiber that is the polymer porous membrane 24 are particles composed of layered double hydroxide LDH. It turns out that. Although not shown in the drawing, the EDX (energy dispersive X-ray spectroscopy) and the X-ray diffraction (X-ray diffraction) described above are the same as in the organic / inorganic hybrid porous membrane 10 of Example Product 1 and Example Product 2. From the organic-inorganic hybrid porous membrane 10 of Example Product 3 and Example Product 4, the scaly particles grown uniformly on the surface of the PVDF membrane fiber, which is the polymer porous membrane 24, are layered double hydroxides. The particles were composed of the product LDH.

  According to the results of Experiment I in FIGS. 6 to 32, in the organic-inorganic hybrid porous membrane 10 of the comparative product 1 to the comparative product 4, the layered double water is formed on the surface of the polymer porous membrane 24 that is the PVDF membrane. Although the particles of the oxide LDH were not coated, in the organic-inorganic hybrid porous membrane 10 of Examples 1 to 4, the layered double hydroxide LDH was formed on the surface of the polymer porous membrane 24 as the PVDF membrane. Of particles were coated. For this reason, it is considered that the scaly layered double hydroxide LDH was deposited on the surface of the polymer porous membrane 24 by the deposition step SA2.

Further, according to the results of Experiment I in FIGS. 6 to 32, in the organic-inorganic hybrid porous membrane 10 of Comparative Example Product 2 and Comparative Example Product 3, the layered double hydroxide LDH particles are formed on the surface of the PVDF membrane. Although not coated, in the organic-inorganic hybrid porous membrane 10 of Example Product 1, the surface of the PVDF membrane was coated with particles of layered double hydroxide LDH. Therefore, in the precipitation step SA2, the urea dissolved in the solution containing the PVDF membrane is 0.420 mol or more, or the urea / [NO ₃ ] molar ratio in the solution is preferably set to 4.0 or more. It is considered that the layered double hydroxide LDH can be coated on the surface of the film.

  Further, according to the result of Experiment I in FIG. 6 to FIG. 32, in the organic-inorganic hybrid porous membrane 10 of Comparative Example 4, the surface of the PVDF membrane was not coated with the layered double hydroxide LDH particles. In the organic-inorganic hybrid porous membrane 10 of Example Product 1, the surface of the PVDF membrane was coated with particles of layered double hydroxide LDH. For this reason, in precipitation process SA2, it is thought that the layered double hydroxide LDH can be suitably coated on the surface of the PVDF film by setting the holding time to 12 hours or longer.

[Experiment II]
Here, Experiment II conducted by the present inventors will be described. This experiment II is for verifying that the organic-inorganic hybrid porous membrane 10 in which the surface of the polymer porous membrane 24, which is a PVDF membrane, is coated with particles of layered double hydroxide LDH has ion conductivity. This is an experiment.

  In this experiment II, first, as shown in FIG. 33, a pair of gold electrodes is used by using the organic-inorganic hybrid porous membrane 10 of Example product 1 and the organic-inorganic hybrid porous membrane 10 of Example product 2 described above. 32 and 34 were attached to both sides of the organic-inorganic hybrid porous membrane 10. The ionic conductivity of the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 when the relative humidity is 80% at an environmental temperature of 80 ° C. by the AC impedance analyzer method. Was measured respectively. In the experiment II, the environmental control of the organic-inorganic hybrid porous membrane 10 is performed using an ESPEC (Japan) SH-221 small environment tester, and the ionic conductivity of the organic-inorganic hybrid porous membrane 10 is controlled. The measurement was performed using an electrical property evaluation apparatus of Solartron Analytical (UK) Solartron 1260 lmpedance / gain-phase analyzer.

Hereinafter, the result of Experiment II will be described with reference to FIG. As shown in FIG. 34, the ionic conductivity of the organic-inorganic hybrid porous membrane 10 of Example Product 1 is 1.2 × 10 ⁻⁶ [S / cm], and the organic-inorganic hybrid porous membrane of Example Product 1 It was found that the membrane 10 itself has ionic conductivity. In addition, the ionic conductivity of the organic-inorganic hybrid porous membrane 10 of Example Product 2 is 1.1 × 10 ⁻⁸ [S / cm], and the organic-inorganic hybrid porous membrane 10 of Example Product 2 has an ionic conductivity. It was found to have conductivity. Although not shown, the organic-inorganic hybrid porous membrane 10 of Example Product 3 and the organic-inorganic hybrid porous membrane 10 of Example Product 4 are also included in the organic-inorganic hybrid porous membrane 10 of Example Product 1 and Similar to the organic-inorganic hybrid porous membrane 10 of Example Product 2, it had ion conductivity.

  34, the organic-inorganic hybrid porous membrane 10 of Example Product 1 and the organic-inorganic hybrid porous membrane 10 of Example Product 2 had ionic conductivity. For this reason, the surface of the polymer porous film 24 which is a PVDF film is coated with particles of the layered double hydroxide LDH, so that the surface of the polymer porous film 24 is coated with the particles of the layered double hydroxide LDH. The formed organic-inorganic hybrid porous membrane 10 is considered to have ionic conductivity.

  According to the result of Experiment II in FIG. 34, the ionic conductivity of the organic-inorganic hybrid porous membrane 10 of Example Product 1 was higher than that of the organic-inorganic hybrid porous membrane of Example Product 2. Further, as described above, the size of the layered double hydroxide LDH particles coated on the surface of the PVDF membrane in the organic-inorganic hybrid porous membrane 10 of Example Product 1 from FIGS. It was smaller than the particles of the layered double hydroxide LDH in the organic / inorganic hybrid porous membrane 10. For this reason, it is considered that the ionic conductivity of the organic-inorganic hybrid porous membrane 10 increases as the size of the layered double hydroxide LDH particles coated on the surface of the PVDF membrane decreases.

  According to the organic-inorganic hybrid porous membranes 10 of Example Product 1 to Example Product 4 of this example, the organic-inorganic hybrid porous membranes 10 of Example Product 1 to Example Product 4 themselves have ionic conductivity. Therefore, when the organic-inorganic hybrid porous membrane 10 of Examples 1 to 4 is used as the base material of the electrolyte membrane 12, the polymer porous membrane 24 having no ion conductivity is used as the electrolyte membrane 12. Compared with the case where it is used as a substrate, the ionic conductivity of the electrolyte membrane 12 is increased. Moreover, the strength of the electrolyte membrane 12 can be improved by using the organic-inorganic hybrid porous membrane 10 of the example product 1 to the example product 4 as a base material of the electrolyte membrane 12. That is, by using the organic-inorganic hybrid porous membrane 10 of Example Product 1 to Example Product 4, an electrolyte membrane 12 having relatively high ionic conductivity and strength can be produced.

  Moreover, according to the organic-inorganic hybrid porous membrane 10 of the example product 1 to the example product 4 of this example, the organic-inorganic hybrid porous membrane 10 of the example product 1 to the example product 4 is used, and the ion The electrolyte membrane 12 for the anion exchange membrane fuel cell 14 is produced by filling the conductive polymer into the pores 10 a of the organic-inorganic hybrid porous membrane 10. For this reason, the ion conductivity and strength of the electrolyte membrane 12 for the anion exchange membrane fuel cell 14 are preferably improved.

  According to the method of manufacturing the organic-inorganic hybrid porous membrane 10 of Example product 1 to Example product 4 of this example, a solution in which a plurality of metal salts such as magnesium nitrate and aluminum nitrate are dissolved is prepared in the solution preparation step SA1. In the precipitation step SA2, the polymer porous membrane 24, which is a PVDF membrane, is placed in the solution, and a small piece of layered double hydroxide LDH is deposited on the surface of the polymer porous membrane 24, so that the polymer porous An organic-inorganic hybrid porous membrane 10 having ion conductivity in which the surface of the membrane 24 is coated with layered double hydroxide LDH particles is obtained, and the organic-inorganic hybrid porous membrane 10 is used as a base material of the electrolyte membrane 12, for example. By using it, the electrolyte membrane 12 having relatively high ion conductivity and strength can be produced.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

In the organic-inorganic hybrid porous membrane 10 of Example product 1 to Example product 4 of this example, the base layer 26 of the inorganic layered double hydroxide LDH coated on the surface of the polymer porous membrane 24 is composed of magnesium ions. (Mg ²⁺ ) and aluminum ions (Al ³⁺ ), but instead of the magnesium ions, divalent metal ions other than magnesium ions such as iron ions (Fe ²⁺ ), zinc ions (Zn ²⁺ ), calcium ions (Ca ²⁺ ), lithium ion (Li ²⁺ ), nickel ion (Ni ²⁺ ), cobalt ion (Co ²⁺ ), copper ion (Cu ²⁺ ), etc., trivalent metal ions other than aluminum ions instead of aluminum ions for example, iron ions ^{(Fe 3+),} manganese ion ^{(Mn 3+),} it may also be cobalt ions ^{(Co 3+)} or the like is used . Further, the basic layer 26 of the layered double hydroxide LDH is not limited to the one having one kind of divalent metal ion and one kind of trivalent metal ion. For example, it may have one type of monovalent metal ion and one type of divalent metal ion, or one type of bivalent metal ion and two types of tetravalent metal ion. . That is, it is only necessary to have one or more types of metal ions having different valences. Note that metal ions of the same element may be included as long as the valences are different from each other. That is, the layered double hydroxide LDH of the present embodiment may be composed of two or more kinds of metal ions having different valences. Moreover, in the organic-inorganic hybrid porous membrane 10 of Example Product 1 to Example Product 4 of this example, the intermediate layer 30 of the layered double hydroxide LDH had carbonate ions (CO ₃ ²⁻ ). Anions other than carbonate ions such as nitrate ions (NO ₃ ⁻ ), hydroxide ions (OH ⁻ ), chloride ions (Cl ⁻ ), bromide ions (Br ⁻ ) and the like may be used.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Organic-inorganic hybrid porous membrane 10a: Pore 12: Electrolyte membrane 14: Fuel cell 24: Polymer porous membrane LDH: Layered double hydroxide SA1: Solution preparation step SA2: Precipitation step

Claims (3)

An organic / inorganic hybrid porous membrane used as a base material for an electrolyte membrane of a fuel cell, wherein the surface of the organic polymer porous membrane is an inorganic layered double hydroxide composed of two or more kinds of metal ions having different valences coated with particles,
The layered double hydroxide particles are scaly particles, and a plurality of basic layers surrounded by the metal ions, and anions and water molecules present between the plurality of basic layers. A layered structure with an intermediate layer consisting of
An organic-inorganic hybrid porous membrane having ion conductivity , characterized in that   An electrolyte membrane for an anion exchange membrane fuel cell, produced by filling the pores of the organic-inorganic hybrid porous membrane with an ion conductive polymer using the organic-inorganic hybrid porous membrane according to claim 1. A method for producing an organic / inorganic hybrid porous membrane having ionic conductivity, in which the surface of an organic polymer porous membrane is coated with inorganic layered double hydroxide particles composed of two or more kinds of metal ions having different valences. There,
A solution preparation step for preparing a solution in which a plurality of metal salts are dissolved;
A method for producing an organic-inorganic hybrid porous membrane comprising: a step of depositing the polymer porous membrane in the solution and precipitating small pieces of layered double hydroxide on the surface of the polymer porous membrane.