JP2002220225A - Zeolite membrane, method for treating zeolite membrane, aluminium electrolytic capacitor, and separating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zeolite membrane having a large contact angle of water and ethylene glycol useful for electrolytic capacitor and separation of material such as alcohol, to provide a capacitor comprising such permeable membrane, and to provide a method for treating the membrane. SOLUTION: To treat a zeolite membrane with a coupling agent by contacting the zeolite membrane with water and/or steam and a treating agent having active groups to be reacted with OH groups and becoming inorganic compounds after firing. To treat a zeolite membrane under heating and/or reduced pressure with a treating agent having functional groups to be able to react with silanol groups of the zeolite after contacting each other in the absence of water. The zeolite membrane thus treated has a large contact angle of water and ethylene glycol, and a high hydrophobicity, and is useful for separation of hydrogen and separation of alcohol and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zeolite membrane, a method for treating a zeolite membrane, and a separation method. Zeolite is a crystal of an inorganic oxide having a pore size of a molecular level. Since it is a crystal, its pore distribution is very uniform, and a zeolite membrane formed from zeolite is promising as a high-performance separation membrane. The present invention relates to a zeolite membrane having particularly high water repellency, a treatment method for improving membrane performance, and a method of using the treated membrane. The zeolite membrane subjected to the treatment of the present invention can reduce the zeolite crystal gap or suppress the adhesion of the liquid film of the hydrophilic substance to the membrane surface, especially in the coexistence of the vapor or liquid of the hydrophilic substance. It can be used as a membrane for gas permeation, gas separation, and liquid separation. For example, it can be effectively used as a separation membrane for a low-concentration alcohol in an aqueous solution, a deaeration membrane in water, a hydrogen permeable membrane for an electrolytic capacitor, or a fuel hydrogen separation membrane for a fuel cell.

[0002]

2. Description of the Related Art Zeolite membranes are polycrystalline and have gaps between crystals. In addition, a crack may occur during firing due to strain. If there are many crystal gaps and cracks in such a membrane, the utilization rate of zeolite pores is low, and high-performance separation performance derived from the properties of zeolite cannot be obtained. Also, the crystal surface of zeolite is a fracture surface of the crystal, and many OH
Having a group. Therefore, there are many OH groups on the zeolite membrane surface and crystal gap. Therefore, the conventional zeolite membrane is
Not only the expected separation performance cannot be obtained due to the existence of crystal gaps and cracks, but also the hydrophilic property derived from the OH groups on the zeolite membrane surface, adheres the hydrophilic substance in the gas and increases the gas permeability. Had the disadvantage of falling off. In particular, when it is used for a hydrogen permeable membrane for an electrolytic capacitor, ethylene glycol as an electrolyte component adheres to the liquid membrane on the membrane surface, and thus has a drawback that hydrogen generated inside cannot be permeated.

As a method of filling crystal grain boundaries and cracks, WO 96/01682 discloses a technique of simultaneously contacting a metal compound and ozone on a film surface to form a metal oxide. In this method, it is essential to use ozone, a dedicated device is required, and the cost is high. The metal compound used in this method is a compound having only a reactive group (an ethoxy group in the case of tetraethoxysilane) such as tetraethoxysilane, and can achieve the purpose of filling the crystal gap, but imparts hydrophobicity to the zeolite membrane surface. I couldn't.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate all the above-mentioned disadvantages, and to treat crystal gaps, surfaces and cracks in a zeolite membrane without using ozone to fill crystal grain boundaries and cracks. Not only that, it imparts hydrophobicity to the zeolite membrane surface and improves permeation selectivity.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present invention has the following structure.

The present invention relates to (1) a zeolite membrane having a contact angle of water of 70 ° or more and a contact angle of ethylene glycol of 65 ° or more. (2) The concentration of fluorine atoms on the surface of the zeolite membrane is 5 × 10 ^-7
mol / m ² or more. (3) A method for treating a zeolite membrane, comprising contacting the zeolite membrane with a treating agent having an active group that reacts with an OH group and becoming an inorganic oxide after firing, and water and / or steam. (4) bringing one surface of the zeolite membrane into contact with the treating agent,
(3) The method for treating a zeolite membrane according to the above (3), wherein the pressure on the other side of the zeolite membrane is lower than the pressure in contact with the treating agent. (5) A method for treating a zeolite membrane, wherein the treating agent is represented by (I) or (II).

(I) R _x -M1-X _4-x (II) R _y -M2-X _3-y (R represents an alkyl group or an aryl group, and X represents an active group which reacts with an OH group. , X represents 0, 1, 2, or 3, y represents 0, 1, or 2. M1 represents any of titanium, silicon, and germanium, and M2 is boron or aluminum.) (6) Treatment agent Is represented by (III) or (IV).

[0008]

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(Where R is an alkyl group or an aryl group, and a part or all of hydrogen is substituted with fluorine, and A is an alkyl group, an aryl group, a methoxy group, an ethoxy group or chlorine. , X is an ethoxy group, a methoxy group or chlorine, M1 is titanium, silicon,
Represents any of germanium, M2 is boron or aluminum. (7) The method for treating a zeolite membrane as described above, wherein R of the treating agents (I) to (IV) has a structure represented by (V). (V) CF ₃ (CF ₂ ) _n (CH ₂ ) _m − (where n is an integer from 0 to 7 and m is an integer from 0 to 3) (8) Zeolite membrane and silanol of zeolite A method for treating a zeolite membrane, comprising subjecting a treating agent having a functional group capable of reacting with a group to contact in the absence of water, followed by heat treatment and / or reduced pressure treatment. (9) The method for treating a zeolite membrane as described above, wherein a treating agent having only one functional group in a molecule capable of reacting with a silanol group of the zeolite is used. (10) An electrolytic capacitor comprising a zeolite membrane treated by the treatment method of (3) to (9) or a zeolite membrane of (1) or (2). (11) A method for separating a substance, wherein the substance to be separated is brought into contact with the zeolite membrane treated by the treatment method according to (3) to (9) or the zeolite membrane of (1) or (2). (12) A method for separating alcohol from a low-concentration aqueous alcohol solution using the zeolite membrane treated by the treatment method according to (3) to (9) or the zeolite membrane of (1) or (2). It is.

[0010] The inventors of the present invention have found that the crystal gap of the zeolite membrane
As a result of intensive studies on a post-treatment method for the zeolite membrane in order to improve the performance of the zeolite membrane by filling the cracks and to improve the hydrophobicity of the zeolite membrane surface, the present invention has been achieved. Using a specific treatment agent, when the treatment method of the present invention is applied, the surface can be hydrophobized, and crystal gaps and cracks can be filled,
A zeolite membrane useful for separation and permeation of hydrophilic substances in the presence of vapor can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The present invention is a zeolite membrane having a contact angle of water of 70 degrees or more and a contact angle of ethylene glycol of 65 degrees or more. The zeolite membrane referred to in the present invention is a membrane containing zeolite or a zeolite analog as a main component. Zeolite is a crystalline inorganic oxide having a pore size of a molecular size. In the present invention, the molecular size means a range of about 2 to 20 angstroms. Zeolites or zeolite analogs are crystalline silicates, crystalline aluminosilicates, crystalline metallosilicates, crystalline aluminophosphates, crystalline microporous materials composed of crystalline metalloaluminophosphates, etc., silica. Zeolites containing components, ie, crystalline silicates, crystalline aluminosilicates, and crystalline metallosilicates are preferred because the inside of the zeolite pores can be made hydrophobic by reducing the number of heteroatoms. An object of the present invention is to make a zeolite membrane hydrophobic, to prevent a polar substance from being blocked by a membrane, or to prevent a polar substance from adhering as a liquid film, thereby improving gas permeation for a long time. For that purpose,
As the zeolite, a high silica crystalline aluminosilicate with Si / Al> 5 and a high silica crystalline metallosilicate with Si / metal> 5 are preferable. Si / Al ratio, S
The higher the i / metal ratio, the more preferable. Particularly, it is preferable to use a crystalline silicate containing only a silica component. Such a zeolite is preferable because the zeolite pores are hydrophobic and the zeolite pores are hardly affected by a hydrophilic substance.

There is no particular limitation on the type of zeolite. For example, Atlas of Zeolite Structure Types (Mayer, Olson, Baerochar, Zeolites, 17 (1/2), 1996): Atlas of Zeolite St
ructure types (WM Meier, DH Olson, Ch. Baerlo
cher, Zeolites, 17 (1/2), 1996).

The zeolite membrane may be a single zeolite membrane, but a membrane formed on a support is preferred because it has higher strength. The material and form of the support are not particularly limited, but it is preferable to use a porous support. The material of the porous support is not particularly limited, but as an example, metal,
Metal oxides and organic polymers. From the viewpoint of heat resistance and chemical resistance, metal oxides are preferably used. The metal oxide is not particularly limited, but alumina, zirconia, silica, mullite, titania, zeolite or a zeolite analog is preferably used. Examples of the metal include a stainless steel porous support (sintered metal).

The shape of the support is not particularly limited.
A commercially available product such as a sphere, a plate, a tube-shaped monolith, and a honeycomb can be used.

The zeolite membrane used in the present invention can be synthesized by a conventionally known method. For example, it can be synthesized by immersing the support in a mixture of a silica source, an alumina source, an alkali source, an organic template, and water and heating the mixture to about 80 to 200 ° C. (hydrothermal synthesis method). At this time, it is preferable that zeolite is applied to the support in advance as a seed crystal. There is also a method in which a mixture of a silica source, an alumina source, an alkali source, an organic template, and water, which are zeolite precursors, is applied to a support, and the mixture is treated with steam at about 80 to 200 ° C. to form a zeolite. Also in this case, it is preferable to previously apply zeolite as a seed crystal to the support (steam synthesis method). That is, the hydrothermal synthesis method is a method in which a support is immersed in a raw material of zeolite for synthesis.
In the steam synthesis method, a zeolite raw material is coated on a support,
After drying, it is a method of synthesizing while applying steam. The steam synthesis method is preferable because crystals having fewer defects can be obtained as compared with the hydrothermal synthesis method.

As a silica source, colloidal silica, fumed silica, water glass, precipitated silica, silicon alkoxide and the like are used. The alkali source is a hydroxide of an alkali metal such as sodium hydroxide, lithium hydroxide, and potassium hydroxide.

As the alkali source, sodium hydroxide,
Alkali metals such as lithium hydroxide and potassium hydroxide,
Examples include alkaline earth metals such as magnesium hydroxide and calcium hydroxide, and quaternary ammonium hydroxides.

The organic template is a template for an organic compound that constructs the pores of zeolite, and includes a tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and the like.
Grade ammonium salts, crown ethers, alcohols and the like are used.

The alumina source is necessary when producing a crystalline aluminosilicate zeolite, but aluminum salts such as ammonium nitrate, ammonium sulfate, aluminum chloride and ammonium acetate, aluminum hydroxide, aluminum oxide and aluminum alkoxide can be used.

The zeolite membrane of the present invention has a water contact angle of 7
0 degree or more, and the contact angle of ethylene glycol is 65 degrees or more. The contact angle of water and tylene glycol on the surface of the zeolite membrane is affected by the affinity / hydrophobicity of the zeolite, which is attributed to the silica / alumina ratio in the structure. A zeolite membrane having a low silica / alumina ratio of 20 or less exhibits a hydrophilic property in its pore structure itself. On the other hand, a zeolite membrane having a high silica / alumina ratio of 50 or more exhibits a hydrophobic property in its pore structure itself.
However, even in a zeolite membrane having a high silica / alumina ratio of 50 or more, crystal defects are present at a high density on the membrane surface, and silanol groups are present in the defective portions. Since the silanol group has a hydrophilic property, the hydrophobicity of the membrane surface is low even in a zeolite membrane having a high silica / alumina ratio. For example, even with a silicalite membrane that is an all-silica zeolite, if it is produced by a generally known synthesis method, the contact angle of water on the membrane surface is 50 degrees or less. The zeolite membrane in the present invention is synthesized with the intention of improving the water repellency of the membrane surface,
And / or treated, with a water contact angle of 7
It indicates 0 ° C. or higher. Here, the contact angle of water is
At the interface between the zeolite membrane and water, it refers to the angle inside the water among the angles formed from the zeolite membrane and the water surface. The measuring method is described below. Drop a water droplet on the zeolite membrane surface and wait for the water droplet surface to stop shaking. Next, the interface between the zeolite membrane and the water droplet is observed from a direction in which the zeolite membrane can be seen horizontally at 90 degrees to the surface of the membrane, and the angle formed from the zeolite membrane surface and the water droplet is measured. The measurement may be performed on the spot with a protractor or the like, or the interface between the zeolite membrane and the water droplet may be photographed and measured on the photograph. Further, the zeolite membrane according to the present invention has a contact angle of ethylene glycol of 65 ° C. or more. The method of measuring the contact angle of ethylene glycol is the same as the method of measuring the contact angle of water.

The present invention relates to a zeolite membrane characterized in that the surface of the zeolite membrane has a fluorine atom concentration of 5 × 10 ⁻⁷ mol / m ² or more. Fluorine on the surface of the zeolite membrane referred to here refers to those contained in the compound directly reacted with the silanol groups on the surface of the zeolite membrane, those contained in the compound deposited on the surface of the zeolite membrane, the grain boundaries of the zeolite membrane, and the cracks in the cracks. Means all fluorine present in the vicinity of the zeolite membrane surface, such as those contained in the material that fills in. The state of the presence of fluorine is not particularly limited, but in particular, a compound containing a group in which a part or all of hydrogen of an alkyl group or an aryl group is substituted with fluorine has high hydrophobicity, and such a compound is present on the surface of the zeolite membrane. In this case, the zeolite membrane is preferably used because the water repellency of the zeolite membrane increases. Among them, a silane coupling agent containing a group in which part or all of hydrogen of an alkyl group or an aryl group has been substituted with fluorine can react with a silanol group on the surface of the zeolite membrane, and significantly reduce the permeation amount of the zeolite membrane. It is preferably used because the water repellency of the zeolite membrane surface can be enhanced. In addition, since the same compound can be polymerized at the grain boundaries and cracks on the surface of the zeolite membrane, it not only increases the water repellency of the zeolite membrane surface, but also contributes to the improvement in the denseness of the zeolite membrane, thereby improving the permeation selectivity. , Used favorably.

As a method for measuring the concentration of fluorine atoms on the surface of the zeolite membrane, any generally known elemental analysis method can be used. For example, ES which is a kind of electron spectroscopy
CA (electron spectroscopy)
The atomic ratio from the surface of the sample to a depth of 5 to 10 nm can be obtained by a for chemical analysis method. The ratio between the total silicon atomic weight and the fluorine atomic weight in this region and the ratio between the coupling agent central atomic weight and the silicon atomic weight caused by the zeolite are determined, and the fluorine atom concentration per unit area is calculated based on these values. it can. Further, as another method, after peeling off the surface layer of the zeolite membrane and obtaining a powdery sample, the amount of fluorine is calculated by a normal elemental analysis method, and the fluorine concentration per unit area is calculated from the peeled zeolite area. There is also a calculation method. If the fluorine concentration is too low, a water-repellent effect cannot be obtained, so that it is preferably 5 × 10 ⁻⁷ mol / m ² or more. If the amount is too large, a polymer containing fluorine atoms may be formed on the surface of the zeolite membrane, and 5 ×
It is preferably at most 10 ^-2 mol / m ² .

Further, the present invention relates to a method for forming a zeolite membrane with OH
A treatment agent having an active group that reacts with a group and becoming an inorganic oxide after firing, and a method for treating a zeolite membrane, which is brought into contact with water and / or steam.

The feature of the method for treating a zeolite membrane in the present invention is that the zeolite membrane has an active group which reacts with an OH group and is brought into contact with water and / or water vapor with a treating agent which becomes an inorganic oxide after firing. is there. The form of the water to be brought into contact may be any state of solid, liquid and gas, and is preferably liquid or gas. The contact temperature may be any temperature, but is preferably 0 ° C. or higher, and more preferably 0 ° C. or higher and 200 ° C. or lower for ease of handling. Water and / or water vapor are preferably introduced before or after contact with the metal compound. Particularly preferably, O
After the zeolite membrane is brought into contact with a treating agent having an active group that reacts with the H group and becoming an inorganic oxide after firing, it is brought into contact with water and / or steam. When water and / or water vapor are simultaneously brought into contact with a treating agent having an active group that reacts with an OH group and becoming an inorganic oxide after firing, the reaction between the surface of the zeolite membrane and the treating agent results in water and treating agent. Is preferentially caused to form an inorganic hydroxide particle layer having poor permeability on the surface of the zeolite membrane. When the treatment agent is brought into contact with water and / or steam after contacting the zeolite membrane with the treatment agent, the water introduced after the treatment agent has reacted with the OH group on the surface of the zeolite membrane causes unreacted active groups in each treatment agent. The networking of the zeolite membranes is preferable because the network can be processed without significantly impairing the permeation performance of the zeolite membrane itself.

The method of contacting the treating agent with the zeolite membrane is as follows.
There is no particular limitation. It may be brought into contact with a liquid or with a vapor. In the case of a liquid, the treatment agent alone or a solution in which the treatment agent is dissolved in a solvent may be used.

The method for treating a zeolite membrane according to the present invention is a method in which one surface of a zeolite membrane is brought into contact with a treating agent, and the pressure on the other surface of the zeolite membrane is made lower than the surface in contact with the treating agent. It is preferably adopted. This method is not particularly limited, for example, a method in which the treatment agent is brought into contact with one surface of the zeolite membrane to increase the pressure on the treatment agent side, or the treatment agent vapor is brought into contact with one surface of the zeolite membrane, and the treatment agent is brought into contact with the carrier gas. The method of increasing the pressure on the side, the method of bringing the treatment agent into contact with one surface of the zeolite membrane, and drawing the other surface of the zeolite film into a vacuum, the method of bringing one surface of the zeolite membrane into contact with the vapor of the treatment agent, There is a method of reducing the pressure on the side opposite to the surface that is in contact with the processing agent by drawing the other surface to a vacuum. The aforementioned carrier gas is selected from gases that do not react with the treating agent, and preferably has a molecular diameter smaller than the zeolite pores.

The pressure difference between the surface in contact with the treatment agent and one surface is not particularly limited as long as it is generated, but is preferably 50 kP.
A pressure difference of at least a and more preferably at least 100 kPa is applied.
The temperature at which the treating agent is brought into contact with the treating agent may be any temperature as long as the treating agent is not decomposed.
It is below ° C.

The treating agent of the present invention is not particularly limited as long as it has an active group which reacts with an OH group and becomes an inorganic oxide after firing. The state of the treatment agent is preferably liquid at room temperature for handling. The state at the time of contact is preferably a liquid or a gas. It is preferable that the substance having a high vapor pressure is brought into contact with the liquid as a vapor, and the substance having a low vapor pressure is brought into contact with a liquid. Dissolve the solid thing in the solvent,
Preferably, it is brought into contact as a liquid. A liquid material may be brought into contact with a solvent dissolved in a solvent. Tetraalkoxysilanes, tetraalkoxytitaniums, metal halides, metal nitrates and the like are examples of the treating agent of the present invention. Specific examples include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrapropoxytitanium, silicon tetrachloride, barium nitrate, and the like.

Here, it is preferable to use the treatment agent represented by (I) or (II).

(I) _Rx- M1-X4- _x (II) _Ry- M2-X3 _-y R is an alkyl group or an aryl group, preferably an alkyl group. The alkyl group is not particularly limited as long as it is a compound containing carbon and hydrogen, but preferably contains fluorine in addition to carbon and hydrogen. The reason is to improve the hydrophobicity of the film by containing fluorine. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1 or more and 20 or less, more preferably 4 or more and 20 or less. As the number of carbon atoms increases, the hydrophobicity increases, which is preferable. M1 represents any of titanium, silicon and germanium, and M2 represents
Boron or aluminum.

X is not limited as long as it is an active group, but is preferably an amino group, an alkoxy group, a hydroxyl group, a proton or a halogen, preferably an alkoxy group, a marine group or a halogen. Alkoxy is most preferred because it is easy to handle.
The alkoxy is not particularly limited, but preferably has 4 carbon atoms.
The following are preferably ethoxy or methoxy. The reason for this is that the alkoxy having a small number of carbon atoms has a high reaction activity with the OH group on the zeolite membrane and is liable to react.

X is 0, 1, 2, or 3, preferably 1 or 2, and most preferably 1. y is 0, 1 or 2, preferably 1 or 2, and more preferably 1. The reason is that it has not only a hydrophobic group but also two or three active groups, it can be networked, and it is easy to fill cracks and grain boundaries.

Examples of the treating agent include silanes such as silane, alkylsilane, arylsilane, alkoxysilane, vinylsilane and aminosilane, aluminum compounds such as alkylaluminum, arylaluminum and alkoxyaluminum, alkylgermane, arylgermane, alkoxygermane, amino Examples include germanium compounds such as germanium, titanium compounds such as alkyl titanium, aryl titanium, alkoxy titanium, vinyl titanium, and amino titanium; and boron compounds such as boron alkoxide, alkyl boron, aryl boron, and amino boron.

Further, when the treating agent is (III) or (I)
V) is preferred.

[0036]

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Here, R is an alkyl group or an aryl group in which part or all of hydrogen has been substituted with fluorine. The carbon number of the alkyl group is not particularly limited, but is preferably 1 or more and 20 or less, more preferably 3 or more and 10 or less.
It is as follows. It is thought that the higher the carbon number, the greater the hydrophobicity and the greater the effect of improving the water repellency.However, the bulky material impedes diffusion of a substance that permeates the membrane near the surface of the membrane, and may reduce the permeation rate. Conceivable. Therefore, those having a large number of carbon atoms are preferably used in applications where water repellency is important, while those having a small number of carbon atoms are preferably used in applications where transmission speed is important.

A is an alkyl group, an aryl group, a methoxy group, an ethoxy group or chlorine, preferably an alkyl group, particularly preferably a methyl group or an ethyl group. In the present invention, the X part of the treating agent (III) or (IV) reacts with the surface of the zeolite membrane, and the R part has a function of increasing the water repellency of the membrane surface. When the portion A is a methoxy group, an ethoxy group or chlorine, the coupling agents bonded to the surface of the zeolite membrane polymerize to form a strong coating layer, and the effect of inhibiting the permeating substance is large. When the A portion is an alkyl group or an aryl group, if the carbon number is large, the bulk becomes bulky and the diffusion of the permeated substance on the zeolite membrane surface is inhibited. For the above reasons, a methyl group or an ethyl group having a low reaction activity and a small number of carbon atoms are preferably used for the portion A.

X is an ethoxy group, a methoxy group or chlorine. M1 represents any of titanium, silicon, and germanium, and M2 represents either boron or aluminum.

Further, the treating agents (I) to (IV) preferably have a structure in which R is represented by (V). (V) CF ₃ (CF ₂ ) _n (CH ₂ ) _m − where n is an integer of 0 to 7, and m is an integer of 0 to 3. The total carbon number is any one of 1 to 11, and it is considered that the larger the carbon number, the greater the hydrophobicity and the greater the effect of improving the water repellency. It is also conceivable that they inhibit the diffusion of water and reduce the permeation rate. Therefore, those having a large number of carbon atoms are preferably used in applications where water repellency is important, while those having a small number of carbon atoms are preferably used in applications where transmission speed is important. As a coupling agent having a large number of carbon atoms, n = 7 and m = 2.
(Heptadecafluoro-1,1,2,2, tetrahydrodecyl) dimethylchlorosilane, (heptadecafluoro-1,1,2,2, tetrahydrodecyl) methyldichlorosilane, (heptadecafluoro-1,1,1,2) 2,
2, tetrahydrodecyl) trichlorosilane. Further, (tridecafluoro-1,1,2,2, tetrahydrooctyl) dimethylchlorosilane or (tridecafluoro-1,1,2,2,2) in which n = 5 and m = 2.
Examples thereof include (tetrahydrooctyl) methyldichlorosilane and (tridecafluoro-1,1,2,2, tetrahydrooctyl) trichlorosilane. As a coupling agent having a small number of carbon atoms, n = 3 and m = 2, (3,
3,4,4,5,5,6,6,6-nonafluorohexyl) dimethylchlorosilane and (3,3,4,4,5
5,6,6,6-nonafluorohexyl) methyldichlorosilane and 3,3,4,4,5,5,6,6,6-nonafluorohexyl) trichlorosilane. Further, (3,3,3-trifluoropropyl) dimethylchlorosilane wherein n = 1 and m = 2,
Examples thereof include (3,3-trifluoropropyl) methyldichlorosilane and (3,3,3-trifluoropropyl) trichlorosilane.

Further, the present invention is characterized in that the zeolite is characterized by contacting a zeolite membrane with a treating agent having a functional group capable of reacting with a silanol group of the zeolite in the absence of water, followed by a heat treatment and / or a reduced pressure treatment. It relates to the treatment of the membrane. When the zeolite membrane is brought into contact with the coupling agent in the absence of water, the silanol group on the zeolite membrane surface reacts with the coupling agent, but the coupling agent has no functional group that causes a condensation reaction. No polymerization reaction occurs between the ring agents. Therefore, after the zeolite membrane and the coupling agent are brought into contact with each other in the absence of water, heat treatment and / or reduced pressure treatment is performed to remove the coupling agent that has not reacted with the silanol groups of the zeolite membrane. it can. In this treatment, in addition to the coupling agent that has reacted with the silanol group on the zeolite membrane surface,
Since no polymer is deposited on the surface of the zeolite membrane, the physical properties of the surface of the zeolite membrane can be changed without greatly reducing the transmittance of the zeolite membrane. As the coupling agent used in this treatment, those having only one site in the molecule that can react with a silanol group are preferably used. For example, monochlorosilane, monoalkoxysilane, monohydroxysilane and the like can be mentioned.

The zeolite membrane subjected to such a treatment method generally has a contact angle of water of 70 ° or more, a contact angle of ethylene glycol of 65 ° or more, has a hydrophobic surface, and has a degassing membrane or a separation membrane. Very useful as. The degassing membrane is used to remove the gas generated by the decomposition of the contents in the container,
It is a film that removes gas components that have melted into the liquid. Zeolites include hydrophobic zeolites and hydrophilic zeolites, but hydrophobic zeolites are preferred for this application.
In the case of a crystalline aluminosilicate zeolite, the higher the silica / alumina molar ratio, the more preferable it is because it has hydrophobic pores. In particular, the zeolite of the present invention is suitable for degassing in the presence of a hydrophilic vapor or a hydrophilic liquid. A typical example of a hydrophobic zeolite is silicalite made of only a silica component.
Examples of use as a degassing membrane include degassing of dissolved oxygen in water and a hydrogen permeable membrane of an aluminum electrolytic capacitor. Aluminum electrolytic capacitors generate hydrogen during use, but when hydrogen accumulates, the internal pressure rises and eventually causes an explosion. The inventors have found that the zeolite membrane of the present invention can be a degassed membrane that suppresses the permeation of electrolyte components and allows only hydrogen to permeate, and has led to the invention of an electrolytic capacitor characterized by mounting the zeolite membrane of the present invention.

An electrolytic capacitor equipped with a zeolite membrane according to the present invention is an electrolytic capacitor having a zeolite membrane having a contact angle of water of 70 ° or more and a contact angle of ethylene glycol of 65 ° or more. Although it is a capacitor, the zeolite membrane is preferably used by being attached to a case or a sealing plug of an electrolytic capacitor, and particularly preferably is attached to a sealing plug. Examples of the mounting method include a method of bonding with a hermetic epoxy adhesive and a method of mounting using an O-ring or a spring, but are not limited thereto.

Next, the electrolytic capacitor of the present invention is shown in the drawings.

An example which can be implemented in FIGS. 1 and 2 is shown below.
FIG. 1 is a cross section of a general electrolytic capacitor. An electrolytic solution is impregnated in a capacitor element 2 wound with kraft paper interposed between an anode foil and a cathode foil, and an anode terminal 3 and a cathode terminal 4 are protruded from a through hole of a sealing plug 1 to make an aluminum container 5.
It is stored in. FIG. 2 shows the sealing plug 1 as viewed from above. The permeable membrane of the present invention is installed, for example, at position 6 in FIG. 2 using an adhesive or an O-ring. The zeolite membrane of the present invention is permeable to hydrogen but not water or ethylene glycol, so that water or ethylene glycol, which is a main component of water vapor or an electrolytic solution, is not easily transmitted, and the composition of the electrolytic solution is not changed. Hydrogen generated by decomposition can escape to the outside, bursting can be avoided, and performance can be stabilized for a long time. As the form of the zeolite membrane used in the present invention, a plate-like one is preferably used. The shape is not particularly limited, and the size may be smaller than the size of the sealing plug, and is preferably smaller than the radius of the sealing plug. The thickness is not particularly limited, as long as it can maintain a mechanical strength that does not break at the time of setting.

The electrolytic capacitor of the present invention has the same configuration as a conventionally known electrolytic capacitor except for the hydrogen-permeable zeolite membrane.

In the electrolytic capacitor of the present invention configured as described above, the hydrogen gas generated in the container 5 during use passes through the zeolite membrane 1 and is discharged to the outside of the electrolytic capacitor. Accumulated inside and damaged,
Since the electrolyte is not broken and the electrolyte can be prevented from evaporating as a liquid or vapor, a long-life capacitor can be obtained.

Next, a separation method using a zeolite membrane in the present invention will be described. Separation using a membrane means
To change the composition ratio of a gas or liquid mixture containing two or more components before and after permeation through a membrane. Since the composition ratio of the zeolite membrane of the present invention can also be changed before and after permeation, it can be used to separate substances.

The invention of a separation method using the zeolite membrane of the present invention as a separation membrane will be described. For separation,
It is necessary that the substance permeate through the zeolite membrane. The transmission driving force is generally a pressure difference and a density difference. Any known method can be used for the separation, but in the case of a liquid, a method such as a pervaporation method or a reverse osmosis method can be adopted. In the case of gas, it can be separated by providing a pressure difference between the gas supply side and the gas permeation side. Also,
For both liquid and gaseous components, there is a method in which a sweep gas is caused to flow on the permeation side of the membrane and separation is performed using a concentration gradient. Usually, in the case of separation, modularization is performed to increase the surface area. For the modularization, a well-known modularization method usually used for a ceramic film can be applied.

A method for separating alcohol from a low-concentration aqueous alcohol solution using the zeolite membrane of the present invention will be described. The low-concentration alcohol aqueous solution here refers to an aqueous solution having an alcohol concentration of less than 20%. For example, when fermenting biomass with fermentation bacteria to obtain alcohol, if the alcohol concentration in the fermentation step is too high, the fermentation bacteria will die,
In the fermentation process, it is obtained as an aqueous alcohol solution of less than 20%. If the zeolite membrane having a high surface water repellency according to the present invention is applied here, the alcohol concentration can be increased before and after permeation.

[0051]

EXAMPLES Reference Example 1 (Synthesis of zeolite membrane) 20 g of a 20-25% aqueous solution of tetrapropylammonium hydroxide (TPAOH) (Tokyo Kasei 20-25
% Aqueous solution) and 0.28 g of NaOH (Katayama reagent first grade) was added and stirred. And 5g of fumed silica (Aldrich)
And heated to 80 ° C. to obtain a transparent aqueous solution. Put this in the Teflon (registered trademark) line autoclave,
After heating at 125 ° C. for 8 hours, fine particles of silicalite (80 nm) were obtained. This was diluted with water to a 1% colloid.

0.1 g of this silicalite colloid is 10 m in diameter.
m, 3 mm thick cylindrical α-alumina porous support (Nippon Insulator: coated on one side with alumina fine particles for a thickness of about 50 μm, average pore diameter is 0.1 μm) on a surface treated with alumina fine particles After coating by dripping as uniformly as possible, it was dried and baked at 550 ° C. for 1 hour.

The surface of the support coated with the silicalite fine particles was immersed in a mixed sol of LUDOX HS40 and a 21.9% TPAOH aqueous solution 1: 1 for 2 minutes. After drying at room temperature for 1 hour, 0.5 g of water was put into a 50 ml autoclave and heated at 120 ° C. for 24 hours under steam pressure. Next, the film sample was fired at 550 ° C. for 2 hours. The temperature was raised at a rate of 0.6 ° C./min and the rate of temperature drop was set at 1.2 ° C./min. X-ray diffraction and an electron microscope confirmed that a silicalite thin film was formed on the support.

The obtained silicalite membrane was incorporated into the permeation cell shown in FIG. 3, hydrogen was supplied from a hydrogen cylinder, and the cylinder pressure was reduced.
The pressure was set to 0.2 MPa, and the hydrogen permeability was measured. The results are shown in Table 1.

The obtained silicalite film was heated at 120 ° C.
After drying in vacuum for 2 hours, the substrate was placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the silicalite film was vacuum-dried again at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of ethylene glycol was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became like.

[0056]

[Table 1]

Example 1 (Treatment with isobutyltriethoxysilane) The silicalite membrane obtained in Reference Example 1 was placed in the cell of FIG. 3 and charged in the apparatus of FIG. Place 30 ml of isobutyltriethoxysilane in a test tube and raise the oven temperature to 150 ° C.
And Hydrogen is supplied from the hydrogen cylinder and the cylinder pressure is 0.2M
Pa was set. The other side was connected to a soap film flow meter and the pressure was set at atmospheric pressure (about 0.1 MPa). The permeated gas flow rate was measured with a soap film flow meter to determine the hydrogen permeability. Initially the hydrogen permeability is 1.
It was ^{7 mol · m -2 s -1 Pa} -1 - 40 x 10. One hour later, when the hydrogen permeability reached 0.111 × 10 ⁻⁷ mol · m ⁻² s ⁻¹ Pa ⁻¹ , the mixture was cooled, and the silicalite membrane treated with isobutyltriethoxysilane was taken out and then placed in room temperature water for 3 minutes. Exposed.

The silicalite film treated with isobutyltriethoxysilane was vacuum-dried at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the silicalite membrane treated with isobutyltriethoxysilane was vacuum-dried again at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of ethylene glycol was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became like.

Example 2 (Treatment with n-hexylsilane) The silicalite membrane obtained in Reference Example 1 was placed in the cell of FIG. 3 and charged in the apparatus of FIG. 30 ml of n-hexylsilane was placed in a test tube, and the temperature of the oven was set to 60 ° C. Hydrogen was supplied from a hydrogen cylinder, and the cylinder pressure was set to 0.2 MPa. The other side is connected to a soap film flow meter, and the pressure is atmospheric pressure (about 0.1MP
a) The permeated gas flow rate was measured with a soap film flow meter to determine the hydrogen permeability. Initial hydrogen permeability is 2.53 x 10
^-7 mol · m ^-2 s ^-1 Pa ^-1 but after 3 hours the hydrogen permeability was 0.14
When 3 x 10 ^-7 mol · m ^-2 s ^-1 Pa ^-1 is reached, cool down
After taking out the silicalite film treated with hexylsilane, it was left in the air for 12 hours.

The silicalite film treated with n-hexylsilane was vacuum-dried at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the silicalite film treated with n-hexylsilane was vacuum-dried again at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of ethylene glycol was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became like.

Example 3 (Treatment with nC ₈ F ₁₇ C ₂ H ₄ Si (OEt) ₃ ) The silicalite film obtained in Reference Example 1 was placed in the cell of FIG. 3 and charged in the apparatus of FIG. NC ₈ F ₁₇ C ₂ H ₄ Si (OEt) _{3 on the} film surface
Was added dropwise, and the film surface was immersed in the treating agent. Vacuum pumped from the opposite side of the membrane. After the treatment was left at room temperature for 1 hour with the treatment agent remaining on the film surface as a liquid, the treatment agent remaining on the film surface was sucked out with a pipette, and the film was taken out of the cell. The removed film surface was washed with pure water for 3 minutes. Further heating was performed at 100 ° C. for 1 hour.

The silicalite film treated with nC ₈ F ₁₇ C ₂ H ₄ Si (OEt) ₃ was vacuum dried at 120 ° C. for 2 hours, and then the treated surface was placed on a plate placed perpendicular to the direction of gravity. Was placed face up. One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the silicalite film treated with nC ₈ F ₁₇ C ₂ H ₄ Si (OEt) ₃ was again vacuum-dried at 120 ° C. for 2 hours,
The substrate was placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of ethylene glycol was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became like.

Further, as a result of ESCA measurement of a silicalite membrane treated with nC ₈ F ₁₇ C ₂ H ₄ Si (OEt) ₃ , the fluorine concentration on the zeolite membrane surface was 1 × 10 ⁻³ mol / m ^2. Was.

Example 4 (Treatment with Si (OMe) ₄ ) The silicalite membrane obtained in Reference Example 1 was placed in the cell of FIG. 3 and charged into the apparatus of FIG. About 30ml of pure water in a test tube
The temperature of the oven 1 was maintained at 30 ° C. Further, the temperature of the oven 2 was set to 100 ° C. The cylinder pressure of the nitrogen cylinder was supplied at 0.2 MPa. One hour later, the nitrogen was turned off and the test tube containing the water was quickly removed. Furthermore, a test tube containing about 30 ml of tetramethoxysilane was attached, and oven 1
Was kept at 30 ° C. Oven 2 temperature 100 ℃
And the cylinder pressure of the nitrogen cylinder was supplied at 0.2 MPa. Initially, the hydrogen permeability was 3.45 × 10 ⁻⁷ mol · m ⁻² s ⁻¹ Pa ⁻¹ . 1
After a lapse of time, the hydrogen permeability became 0.651 x 10 ^-7 mol · m ^-2 s ^-1 Pa ^-1 . After cooling, the silicalite membrane treated with Si (OMe) ₄ was taken out and baked at 550 ° C for 2 hours. did.

Further, the silicalite film treated with Si (OMe) ₄ was vacuum-dried at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. . One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the silicalite film treated with Si (OMe) ₄ was again vacuum-dried at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward.
One drop of ethylene glycol is dropped on the treated surface, and 30 drops after dropping.
Seconds later, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror CA-
Table 2 shows the results obtained by using a type D (manufactured by Kyowa Interface Science Co., Ltd.).

Example 5 (Treatment with n-CF ₃ CH ₂ CH ₂ SiMe ₂ Cl) The silicalite film obtained in Reference Example 1 was vacuum dried at 120 ° C. for 2 hours. Next, a solution was prepared by adding n-CF ₃ CH ₂ CH ₂ SiMe ₂ Cl to 10% by weight of sufficiently dehydrated diethyl ether.
Let stand for minutes. Next, the membrane was taken out of the solution and washed several times with sufficiently dehydrated diethyl ether. 120 ° C
For 2 hours under vacuum.

After the silicalite film treated with n-CF ₃ CH ₂ CH ₂ SiMe ₂ Cl is vacuum dried at 120 ° C. for 2 hours, the treated surface is directed upward on a plate placed perpendicular to the direction of gravity. And put it on. One drop of water was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became so. Next, the film was vacuum-dried again at 120 ° C. for 2 hours, and then placed on a plate placed perpendicular to the direction of gravity with the treated surface facing upward. One drop of ethylene glycol was dropped on the treated surface, and 30 seconds after the drop, the contact angle between the surface of the permeable membrane and the droplet was measured using an optical mirror type CA-D type (manufactured by Kyowa Interface Science Co., Ltd.). It became like.

Further, as a result of ESCA measurement of the silicalite membrane treated with n-CF ₃ CH ₂ CH ₂ SiMe ₂ Cl, the fluorine concentration on the zeolite membrane surface was 1 × 10 ⁻³ mol / m ² .

[0069]

[Table 2]

Example 6 (Measurement of Hydrogen Permeability) The membranes prepared in Examples 1 to 5 were incorporated into the permeation cell shown in FIG. 3 and then incorporated into the apparatus shown in FIG. Hydrogen was supplied from a hydrogen cylinder, the cylinder pressure was set to 0.2 MPa, and the permeate side was connected to a soap film flow meter to measure hydrogen permeability. Table 3 shows the results.

[0071]

[Table 3]

Comparative Example 1 (Hydrogen Permeability of Untreated Membrane in Ethylene Glycol Atmosphere) The membrane of Reference Example 1 was put in the cell of FIG. 3 and incorporated in the apparatus of FIG. 30 ml of ethylene glycol was placed in the test tube, and the temperature of the oven was set at 105 ° C. Set the pressure of the hydrogen cylinder to 0.
The pressure was set to 2 MPa, and the permeation side was connected to a soap film flow meter to measure the hydrogen permeability. 23 hours after the start of measurement, the hydrogen permeability is 0.330 x
It was 10 ^-7 mol · m ^-2 s ^-1 Pa ^-1 . The transmittance reduction rate is 89
% (Table 3) Example 7 (Ethylene glycol permeation experiment) The treated zeolite membrane obtained in Examples 1 to 5 is shown in FIG.
And charged into the apparatus shown in FIG. 30 ml of ethylene glycol was placed in a test tube, and the entire apparatus was heated to 105 ° C. Hydrogen was supplied from a hydrogen cylinder, the cylinder pressure was set to 0.2 MPa, and the permeate side was connected to a soap film flow meter to measure hydrogen permeability. Table 3 shows the hydrogen transmission rate 23 hours after the start of the measurement and the reduction rate of the hydrogen transmission rate in the presence of ethylene glycol vapor.

Comparative Example 2 (Application of Untreated Membrane to Electrolytic Capacitor) The membrane of Reference Example 1 was placed in the cell of FIG. 3, incorporated in the apparatus of FIG. 8, and ethylene glycol was placed in the test tube portion. The device was placed in an 85 ° C. oven. After 30 hours, the weight is 9.39 x
It decreased by 10 ^-3 g. When the surface of the film was observed at the end of the experiment, dew condensation due to ethylene glycol was observed. This membrane was fixed to a sealing plug as shown in FIG. 2 in order to adapt it to a large aluminum electrolytic capacitor. As shown in FIG. 11, a spring was applied to the surface of the permeable membrane where zeolite was not attached, and this was fixed between the upper and lower ends of the sealing plug. Using this sealing plug, a large screw terminal type electrolytic capacitor was prepared. The electrolytic capacitor was placed in an oven at 85 ° C., and a voltage of 470 V was applied to the electrode. After 1000 hours of use, the state of the silicone rubber was visually checked, and the silicone rubber was slightly swollen. Further, when the film was taken out of the condenser, the electrolytic solution was attached to the surface. Further, when the hydrogen permeability was measured, no hydrogen was permeated.

Example 8 (Application of the Membrane of Example 3 to an Electrolytic Capacitor) The treated zeolite membrane obtained in Example 3 was put in the cell of FIG. 3, incorporated in the apparatus of FIG. 8, and ethylene glycol was added to the test tube portion. Was put. The device was placed in an 85 ° C. oven. After 30 hours, the weight had decreased by 1.33 × 10 ⁻³ g. When the surface of the film was observed after the end of the experiment, droplets of ethylene glycol were not seen, and no dew condensation was observed. This membrane was fixed to a sealing plug as shown in FIG. 2 in order to adapt it to a large aluminum electrolytic capacitor. As shown in FIG. 11, a spring was applied to the surface of the permeable membrane where zeolite was not attached, and this was fixed between the upper and lower ends of the sealing plug. Using this sealing plug, a large screw terminal type electrolytic capacitor was prepared. The electrolytic capacitor was placed in an oven at 85 ° C., and a voltage of 470 V was applied to the electrode. After a lapse of 1000 hours, the state of the silicone rubber was visually confirmed, and the silicone rubber did not swell at all. Further, when the film was taken out of the condenser, no adhesion of the electrolytic solution to the surface was observed. When the hydrogen permeability of the membrane after use was measured, it was 0.52 x 10 ^-7 mol · m ^-2 s
^-1 Pa ^-1 .

Example 9 (Hydrogen / Water Permeation Experiment of the Membrane of Example 3) Of the silicalite membrane obtained in Example 3, membrane 4 was placed in the cell of FIG. 9 and charged into the apparatus of FIG. About 30 ml of pure water was put into the test tube, and the temperature of the oven 1 was kept at 40 ° C. The water vapor pressure at that time was 6.5 kPa. Next, the temperature of the oven 3 was set to 120 ° C., hydrogen was supplied from a hydrogen cylinder, and the cylinder pressure was set to 0.2 MPa. The vent was opened, and the ratio of the gas flow rate flowing to the vent side to the gas flow rate flowing to the membrane side was adjusted to be about 20/1. The ratio of hydrogen / water vapor of the gas permeating the membrane was measured by gas chromatography. When the hydrogen / steam permeation selectivity α was determined from the measurement results in Equation 1, the selectivity α was 4.5.

Α = (S ′ (hydrogen) / S ′ (water)) / (S (hydrogen) / S (water)) (Formula 1) S (hydrogen), S (water): Permeation through membrane GC analysis area of hydrogen or water in premixed gas S '(hydrogen), S' (water):
GC Analysis Area of Hydrogen or Water Example 10 (Ethanol / Water Separation Experiment of Membrane of Example 5) The silicalite membrane obtained in Example 5 was placed in the cell of FIG. 9 and charged into the apparatus of FIG. An ethanol / water mixture (weight ratio 10:90) was brought into contact with the membrane surface, and a vacuum pump was pulled from the opposite side of the membrane. A liquid nitrogen temperature trap was installed between the membrane and the vacuum pump to collect all the permeated components.
From the result of measuring the composition ratio of the permeating component by gas chromatography, the permeation selectivity α of ethanol / water was determined to be 150 according to the expression 2, and the selectivity α was 150.

Α = (S ′ (hydrogen) / S ′ (water)) / (S (hydrogen) / S (water)) (Formula 2) S (ethanol), S (water): Permeation through membrane In the premix
Concentration of ethanol or water S '(ethanol), S' (water): GC analysis area of ethanol or water in the mixed solution after permeation

[0078]

The zeolite membrane of the present invention has high surface water repellency and is effective for separating a hydrophobic substance from a hydrophilic substance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of an aluminum electrolytic capacitor.

FIG. 2 is a schematic view of a sealing plug.

FIG. 3 is a diagram of a cell for fixing a zeolite membrane.

FIG. 4 is a diagram of an apparatus used for zeolite membrane treatment and permeation experiments.

FIG. 5 is a diagram of an apparatus used for processing a zeolite membrane.

FIG. 6 is a diagram of an apparatus used for tetramethoxysilane treatment of a zeolite membrane.

FIG. 7 is an apparatus diagram used for a hydrogen permeation experiment.

FIG. 8 is a diagram of an apparatus used for an ethylene glycol permeation experiment.

FIG. 9 is a diagram of a cell for fixing a zeolite membrane.

FIG. 10 is a diagram of a gas permeation selectivity measuring device.

FIG. 11 is a sectional view of a sealing plug.

FIG. 12 is a schematic view of an ethanol / water separation experiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing stopper 2 Aluminum thin film 3 Anode 4 Cathode 5 Outer container 6 Permeable membrane 7 Silicone rubber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 29/76 C07C 29/76 31/08 31/08 31/20 31/20 A H01G 9/12 H01G 9 / 12 A F term (reference) 4D006 GA03 GA25 GA41 MA02 MA03 MA04 MA09 MA21 MB04 MB10 MB15 MB19 MB20 MC02 MC03X MC86 NA46 NA50 NA54 NA62 PA03 PB12 PB18 PB32 PB66 PC01 PC12 4G073 BA20 BA56 BA57 BA63 BA64 BA80 BD18 CZ006 UA06 AD18 DA25 FE11

Claims (12)

[Claims] 1. A zeolite membrane having a contact angle of water of 70 ° or more and a contact angle of ethylene glycol of 65 ° or more. 2. The method according to claim 1, wherein the concentration of fluorine atoms on the surface of the zeolite membrane is 5 ×.
A zeolite membrane having a content of 10 ^-7 mol / m ² or more. 3. A method for treating a zeolite membrane, comprising contacting the zeolite membrane with a treating agent having an active group that reacts with an OH group and becoming an inorganic oxide after firing, and water and / or steam. . 4. The zeolite membrane according to claim 3, wherein one surface of the zeolite membrane is brought into contact with the treating agent, and the pressure on the other surface of the zeolite membrane is made lower than the surface in contact with the treating agent. Method for treating zeolite membranes. 5. The method for treating a zeolite membrane according to claim 3, wherein the treating agent is represented by (I) or (II). (I) _Rx- M1-X4 _-x (II) _Ry- M2-X3 _-y (R represents an alkyl group or an aryl group, X represents an active group that reacts with an OH group, and x represents 0, 1, 2, or 3, y represents 0, 1, or 2. M1 represents any of titanium, silicon, and germanium, and M2 is boron or aluminum.) 6. The method for treating a zeolite membrane according to claim 3, wherein the treating agent is represented by (III) or (IV). Embedded image (Where R is an alkyl group or an aryl group,
A part of or all of hydrogen is replaced by fluorine,
A is an alkyl group, an aryl group, a methoxy group, an ethoxy group or chlorine, and X is an ethoxy group, a methoxy group or chlorine. M1 represents any of titanium, silicon, and germanium, and M2 is boron or aluminum. ) 7. The method for treating a zeolite membrane according to claim 5, wherein R of the treating agents (I) to (IV) has a structure represented by (V). (V) CF ₃ (CF ₂ ) _n (CH ₂ ) _m − (where n is an integer from 0 to 7 and m is an integer from 0 to 3) 8. A treatment of a zeolite membrane, which comprises subjecting a zeolite membrane to a treating agent having a functional group capable of reacting with a silanol group of the zeolite in the absence of water, followed by heat treatment and / or reduced pressure treatment. Method. 9. The method for treating a zeolite membrane according to claim 8, wherein a treating agent having only one functional group in a molecule capable of reacting with a silanol group of the zeolite is used. 10. An aluminum electrolytic capacitor equipped with a zeolite membrane treated by the treatment method according to any one of claims 3 to 9, or a zeolite membrane according to claim 1 or 2. 11. A zeolite membrane treated by the treatment method according to any one of claims 3 to 9, or a substance characterized by contacting the substance to be separated with the zeolite membrane according to claim 1 or 2. Separation method. 12. An alcohol from an aqueous alcohol solution having an alcohol concentration of less than 20% using the zeolite membrane treated by the treatment method according to any one of claims 3 to 9 or the zeolite membrane according to claim 1 or 2. Separation method.