WO2016052075A1

WO2016052075A1 - Gas separation membrane, method for producing gas separation membrane, gas separation membrane module and gas separator

Info

Publication number: WO2016052075A1
Application number: PCT/JP2015/075187
Authority: WO
Inventors: 勇輔望月; 澤田　真; 岳史成田; 滋英伊藤; 浩之野田; 向井　厚史
Original assignee: 富士フイルム株式会社
Priority date: 2014-09-30
Filing date: 2015-09-04
Publication date: 2016-04-07
Also published as: MY180782A

Abstract

A gas separation membrane which has a resin layer containing a compound that has a siloxane bond, said resin layer containing a compound that has a siloxane bond satisfying formula 1 and formula 2, and which has high gas permeability and/or high gas separation selectivity under high pressure; a method for producing a gas separation membrane; a gas separation membrane module; and a gas separator. Formula 1: 0.9 ≥ A/B ≥ 0.55 Formula 2: B ≥ 1.7 In the formulae, A represents an O/Si ratio that is a ratio of the number of oxygen atoms relative to the number of silicon atoms contained in the resin layer containing a compound that has a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound that has a siloxane bond; and B represents an O/Si ratio that is a ratio of the number of oxygen atoms relative to the number of silicon atoms in the surface of the resin layer containing a compound that has a siloxane bond.

Description

Gas separation membrane, gas separation membrane manufacturing method, gas separation membrane module, and gas separation device

The present invention relates to a gas separation membrane, a method for producing a gas separation membrane, a gas separation membrane module, and a gas separation device. More specifically, the first and fourth aspects of the present invention include a gas separation membrane having high gas separation selectivity under high pressure, a method for producing the gas separation membrane, and the gas separation membrane. The present invention relates to a gas separation membrane module and a gas separation device having the gas separation membrane module described above. More specifically, the second aspect of the present invention is a gas separation membrane having high gas permeability and gas separation selectivity under high pressure and good bending resistance, and a gas having the gas separation membrane described above. The present invention relates to a separation membrane module and a gas separation device having the gas separation membrane module described above. More specifically, the third aspect of the present invention is a gas separation membrane having at least one of gas permeability and gas separation selectivity under high pressure and excellent pressure resistance, and a gas having the gas separation membrane described above. The present invention relates to a separation membrane module and a gas separation device having the gas separation membrane module described above.

A material made of a polymer compound has a gas permeability unique to each material. Based on the properties, a desired gas component can be selectively permeated and separated by a membrane composed of a specific polymer compound (gas separation membrane). As an industrial application of this gas separation membrane, it is related to the problem of global warming, and it is considered to separate and recover it from large-scale carbon dioxide generation sources in thermal power plants, cement plants, steelworks blast furnaces, etc. Has been. This membrane separation technology is attracting attention as a means to solve environmental problems with relatively small energy, and mainly contains natural gas and biogas containing methane and carbon dioxide (biological wastes, organic fertilizers, biodegradable substances, It is used as a means for removing carbon dioxide from gas generated by fermentation and anaerobic digestion of sewage, garbage and energy crops.
The following methods are known in order to secure gas permeability and gas separation selectivity by making a portion contributing to gas separation into a thin layer in order to obtain a practical gas separation membrane. A method of making a portion contributing to separation as an asymmetric membrane a thin layer called a skin layer, or a thin layer providing a thin layer (Selective Layer) contributing to gas separation on a support having mechanical strength A method using a thin film composite (Thin Film composite) or a method using a hollow fiber including a high density layer contributing to gas separation is known.

The typical performance of the gas separation membrane includes gas separation selectivity when obtaining a desired gas from a mixed gas and gas permeability of the desired gas. Among them, gas separation membranes having various configurations have been studied for the purpose of improving gas permeability and gas separation selectivity.

For example, in Patent Document 1, a non-porous intermediate layer containing a compound having a siloxane bond is provided on a porous support, and a gas separation membrane having a layer containing cellulose triacetate or polyimide thereon is provided. A method for improving gas separation selectivity such as a mixed gas of carbon dioxide and methane is described.

In Patent Document 2, low-temperature plasma treatment was performed on the surface of the gas separation composite membrane with a non-polymerizable gas, and then a thin layer film of a silicon-containing polymer such as a compound having a siloxane bond was formed on the plasma treatment surface. A method for producing a laminated composite membrane for gas separation that is highly selective (gas separation selectivity) is described. In this document, polydimethylsiloxane or the like is cited as an example of a gas separation composite membrane that is subjected to low-temperature plasma treatment. Further, in this document, argon or the like is cited as a non-polymerizable gas used in the low temperature plasma treatment. In each example of this document, only an example in which low-temperature plasma treatment is performed on the surface of a composite membrane for gas separation made of a polydimethylsiloxane copolymer using argon gas as a non-polymerizable gas is described. .

Patent Document 3 discloses a composite film in which a thin film made of a siloxane compound having a specific structure is laminated on a polymer porous support, and a plasma polymerized film is laminated on the thin film. A composite membrane in which only the layer is plasma treated with a non-polymerizable gas is described, and the composite membrane having such a structure is described as having excellent gas selective permeability (high gas separation selectivity and high gas permeability). .

In Patent Document 4, in a thin-layer composite membrane having a support and a layer having separation selectivity made of polydimethylsiloxane or the like, a hydrophilic layer having a thickness of 0.1 μm or less is formed on the surface of the layer having separation selectivity. A method is described in which the modified surface is provided by performing UV ozone irradiation treatment or subsequent silane coupling agent treatment. In the example of this document, it is described that the film thickness of the hydrophilic modification surface provided on the surface of the layer having separation selectivity is about 1 nm to 21 nm, and if it is too thick, the gas permeability decreases.
In this document, plasma processing is described in parallel with UV ozone irradiation processing as an example of hydrophilic modification processing, but an example using plasma processing was not disclosed in the embodiment of this document. . In addition, in this document, as an example of plasma processing, a method of introducing atmospheric gas mainly into argon gas in a process chamber and performing atmospheric pressure plasma processing is cited.

Non-Patent Document 1 discloses that the surface of a film composed of a polyimide support and polydimethylsiloxane is treated with a low power of 5 W or less in a minute order (120 seconds), and 30 minutes after treatment under atmospheric pressure at 30 minutes. It has been shown that the ratio of carbon dioxide permeability to carbon is increased compared to the original polydimethylsiloxane, but high gas separation selectivity is not obtained.
Non-Patent Document 2 describes that the ratio of oxygen atoms to silicon atoms on the surface increases to 1.6 by treating the surface of the polydimethylsiloxane membrane with high-temperature atmospheric pressure plasma. Selectivity is not obtained.

JP-A-61-54222 JP 60-139316 A Japanese Patent Publication No. 3-8808 JP 2013-75264 A

However, when it is actually used in a natural gas refining process, it has been required to treat the mixed gas under high pressure by a gas separation membrane. When the present inventors examined the performance of the gas separation membrane described in these documents, it was found that there was a problem of low gas permeability and gas separation selectivity under high pressure. For example, none of the gas separation membranes described in

Non-Patent Documents

1 and 2 showed high separability under high pressure.

The problem to be solved by the first and fourth aspects of the present invention is to provide a gas separation membrane having high gas permeability and high gas separation selectivity under high pressure.

Furthermore, when the present inventors examined the bending resistance of the gas permeation performance when the gas separation membrane described in Patent Documents 1 to 4 and

Non-Patent Documents

1 and 2 is wound around a roll, the bending resistance is poor. I understood.
The problem to be solved by the second aspect of the present invention is to provide a gas separation membrane having a high bending resistance and at least one of gas permeability under high pressure and gas separation selectivity.

On the other hand, depending on the natural gas site, there are sites where the pressure is high and the pressure is further increased. Therefore, the present inventors examined the pressure resistance of the gas permeation performance when the gas separation membrane described in Patent Documents 1 to 4 and

Non-Patent Documents

1 and 2 are wound around a roll, and found that the pressure resistance is poor. It was.
The problem to be solved by the third aspect of the present invention is to provide a gas separation membrane that has high gas permeability under high pressure and gas separation selectivity and is excellent in pressure resistance.

As a result of intensive studies by the present inventors to solve the problem to be solved by the first aspect of the present invention, a gas separation membrane having a resin layer containing a compound having a siloxane bond, By allowing oxygen atoms to penetrate from the surface of the resin layer containing a compound having a bond to the thickness direction of the resin layer containing a compound having a siloxane bond to at least 10 nm, at least one of gas permeability under high pressure and gas separation selectivity It has been found that a high gas separation membrane can be obtained.

As a result of intensive studies by the present inventors in order to solve the problem to be solved by the second aspect of the present invention, a gas separation membrane having a resin layer containing a compound having a siloxane bond has a porous support. By including the region GLi existing in the body B and the region GLe existing on the porous support B, and further controlling the layer configuration and the composition of each region to a specific range, It has been found that a gas separation membrane having high permeability and gas separation selectivity and high bending resistance can be obtained.
Note that the gas separation membranes produced by the methods described in Patent Documents 1 to 4 and

Non-Patent Documents

1 and 2 do not have GLe and GLe defined in the present invention, or layers of GLe and GLe defined in the present invention. It was out of the composition or composition range of each region.

As a result of intensive studies by the present inventors to solve the problem to be solved by the third aspect of the present invention, a gas separation membrane having a resin layer containing a compound having a siloxane bond, By controlling the minimum value of the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a bond within a specific range, gas permeability and gas under high pressure It has been found that a gas separation membrane having high separation selectivity and excellent pressure resistance can be obtained.
Note that the gas separation membranes manufactured by the methods described in Patent Documents 1 to 4 and

Non-Patent Documents

1 and 2 have a minimum range of the ratio of the Si ²⁺ and Si ³⁺ peaks defined in the present invention to the total Si peak. I was off.

The problem to be solved by the fourth aspect of the present invention will be described.
It is generally considered that the gas separation selectivity of a gas separation membrane correlates with the pore diameter of minute pores existing in the membrane. Here, as a method for obtaining the pore diameter of the minute vacancy existing in the film, a method of obtaining by calculation by measuring the third component positron lifetime τ3 by the positron annihilation method is known.
The inventors of the present invention calculated the pore size of the microscopic vacancy existing in the gas separation membrane obtained by the method described in Non-Patent Document 1 by measuring the positron lifetime τ3 of the third component by the positron annihilation method. . As a result, for example, in the gas separation membrane manufactured by the method described in Non-Patent Document 1, the positron lifetime τ3 of the third component when the positron is injected with the intensity of 1 keV from the surface of the membrane by the positron annihilation method is 4. 21 (ns).
On the other hand, the film obtained by depositing silica by CVD had a third component positron lifetime τ3 of 3.15 (ns) when positrons were injected from the surface of the film by the positron annihilation method with an intensity of 1 keV.
As a result of intensive studies by the present inventors to solve the problem to be solved by the fourth aspect of the present invention, positrons are emitted from the surface of the resin layer containing a compound having a siloxane bond with an intensity of 1 keV. By controlling the positron lifetime τ3 of the third component in a specific range when implanted, it has been found that a gas separation membrane having at least one of high gas permeability and gas separation selectivity under high pressure can be obtained. .
Note that the gas separation membranes manufactured by the methods described in Patent Documents 1 to 4 and Non-Patent Document 2 also injected positrons with a strength of 1 keV from the surface of the resin layer containing the compound having a siloxane bond specified in the present invention. In this case, the positron lifetime τ3 of the third component was out of a specific range.

The present invention, which is a specific means for solving the above problems, is as follows.
[1] A gas separation membrane that satisfies any one of the following conditions 1 to 4;
Condition 1: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which a resin layer containing a compound having a siloxane bond satisfies the following

formulas

1 and 2;
Formula 1 0.9 ≧ A / B ≧ 0.55
Formula 2 B ≧ 1.7
In Formula 1 and Formula 2, A is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms. Represents an O / Si ratio, and B represents an O / Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond;
Condition 2: porous support A,
A gas separation membrane having a resin layer containing a compound having a siloxane bond located on the porous support A,
The compound having a siloxane bond has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3),
A resin layer containing a compound having a siloxane bond includes a region GLi present in the porous support B and a region GLe present on the porous support B;
The thickness of GLe is 50 to 1000 nm,
The thickness of GLi is 20 nm or more and 10 to 350% of the thickness of GLe;
The difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is 30 to 90%. Gas separation membrane;

In General Formula (2) and General Formula (3), R ¹¹ represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3);
Condition 3: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane having a minimum value Si ₀ of 1 to 40% of the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond;
Condition 4: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which a positron lifetime τ3 of a third component is 3.40 to 4.20 ns when a positron is injected at a strength of 1 keV from the surface of a resin layer containing a compound having a siloxane bond.
[2] The gas separation membrane according to [1] preferably satisfies condition 1.
[3] In the gas separation membrane according to [2], the compound having a siloxane bond includes at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3). Preferably having;

In General Formula (2) and General Formula (3), R ¹¹ represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3).
[4] In the gas separation membrane according to [2] or [3], the compound having a siloxane bond described above preferably has a repeating unit represented by the following general formula (1);
General formula (1)

In general formula (1), each R independently represents a hydrogen atom, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group, a fluorinated alkyl group, a vinyl group, an alkoxy group or a carboxyl group, and n is Represents an integer of 2 or more.
[5] In the gas separation membrane according to [4], the surface of the resin layer containing the compound having a siloxane bond is a repeating unit represented by the general formula (1) and at least the general formula It is preferable to include a compound having a siloxane bond having the repeating unit represented by (2) or the repeating unit represented by the general formula (3).
[6] In the gas separation membrane according to any one of [2] to [5], the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond is 1. It is preferable that it is 6 or less.
[7] In the gas separation membrane according to any one of [2] to [6], B is preferably 1.95 or more;
B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
[8] The gas separation membrane according to any one of [2] to [7] preferably has an A / B of 0.6 or more;
A represents an O / Si ratio which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms. , B represents an O / Si ratio which is a ratio of the number of silicon atoms to the number of oxygen atoms on the surface of the resin layer containing a compound having a siloxane bond.
[9] The gas separation membrane according to any one of [2] to [8] preferably has an A / B of 0.65 or more;
A is the ratio of the number of oxygen atoms to the number of silicon atoms in the resin layer containing the compound having the siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having the siloxane bond, B represents an O / Si ratio that is a ratio of the number of silicon atoms to the number of oxygen atoms on the surface of the resin layer containing the compound having a siloxane bond.
[10] The gas separation membrane according to any one of [2] to [9] preferably further includes a layer containing a polyimide compound.
[11] In the gas separation membrane according to any one of [2] to [10], the layer containing the polyimide compound preferably has a thickness of 0.03 to 0.3 μm.
[12] In the gas separation membrane according to any one of [2] to [11], the thickness of the resin layer containing the compound having a siloxane bond is preferably 0.1 to 5 μm.
[13] In the gas separation membrane according to any one of [2] to [12], the resin layer containing a compound having a siloxane bond has a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom. Is preferred.
[14] The gas separation membrane according to any one of [2] to [13] preferably further includes a support.
[15] In the gas separation membrane according to any one of [2] to [14], the gel fraction of the gas separation membrane is preferably 45% or more.
[16] The gas separation membrane according to [1] preferably satisfies condition 2.
[17] The gas separation membrane according to [16] preferably has a GLe thickness of 200 to 900 nm.
[18] In the gas separation membrane according to [16] or [17], the thickness of GLi is preferably 20 to 90% of the thickness of GLe.
[19] The gas separation membrane according to [1] preferably satisfies condition 3.
[20] The gas separation membrane according to [19] has a minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond. the ratio _{Si 10} with respect to the total Si peak position from the definitive a depth of 10 nm ^{Si 2+} and ^{Si 3+,} the difference Δ1 between 50 and between the ratio minimum value Si ₀ of relative peaks of the total Si peak of ^{Si 2+} and ^{Si 3+} 90 % Is preferred.
[21] The gas separation membrane according to [19] or [20] is a minimum value of the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond. the difference from the position having the Si ₀ the ratio _{Si 20} with respect to the total Si peak ^{Si 2+} and ^{Si 3+} which definitive a depth of 20 nm, a ratio minimum value Si ₀ of relative peaks of the total Si peak of ^{Si 2+} and ^{Si 3+} Delta] 2 Is preferably 55 to 90%.
[22] In the gas separation membrane according to any one of [19] to [21], the thickness of the resin layer containing a compound having a siloxane bond is preferably 150 to 900 nm.
[23] The gas separation membrane according to any one of [19] to [22] preferably further includes a support.
[24] The gas separation membrane according to [1] preferably satisfies condition 4.
[25] The gas separation membrane according to [24] has a relative intensity I3 of the third component of 13 to 41% when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond. It is preferable to become.
[26] In the gas separation membrane according to [24] or [25], the positron lifetime τ3 of the third component when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond is X , Y is the positron lifetime τ3 of the third component when a positron is injected at 3 keV from the surface of the resin layer containing a compound having a siloxane bond.
0.88 ≦ X / Y ≦ 0.99
It is preferable to satisfy.
[27] The gas separation membrane according to any one of [24] to [26] preferably further includes a layer containing a polyimide compound.
[28] In the gas separation membrane according to [27], the layer containing the polyimide compound preferably has a thickness of 0.03 to 0.3 μm.
[29] In the gas separation membrane according to any one of [24] to [28], the thickness of the resin layer containing a compound having a siloxane bond is preferably 0.1 to 5 μm.
[30] The gas separation membrane according to any one of [24] to [29], wherein the resin layer containing a compound having a siloxane bond has a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom It is preferable to contain.
[31] The gas separation membrane according to any one of [24] to [30] preferably further includes a support.
[32] A gas separation membrane module having the gas separation membrane according to any one of [1] to [31].
[33] A gas separation device having the gas separation membrane module according to [32].
[34] A method for producing a gas separation membrane satisfying the following condition P1 or the following condition P4;
Condition P1: including an oxygen atom permeation treatment step of permeating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm ³ (STP) / min or more and an input power of 23 W or more;
Condition P4: including an oxygen atom infiltration treatment step for infiltrating oxygen atoms into the resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 45 cm ³ (STP) / min or more, and using anode coupling at an input power of 23 W or more.
[35] The method for producing a gas separation membrane according to [34] preferably satisfies the condition P1.
[36] In the method for producing a gas separation membrane according to [35], the resin layer containing a compound having a siloxane bond preferably contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
[37] In the method for producing a gas separation membrane according to [35] or [36], a resin layer containing a compound having a siloxane bond is preferably formed on a support.
[38] A gas separation membrane produced by the method for producing a gas separation membrane according to any one of [35] to [37].
[39] The method for producing a gas separation membrane according to [34] preferably satisfies the condition P4.
[40] In the method for producing a gas separation membrane according to [39], the resin layer containing a compound having a siloxane bond preferably contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
[41] In the method for producing a gas separation membrane according to [39] or [40], it is preferable that a resin layer containing a compound having a siloxane bond is formed on a support.

In the present specification, when there are a plurality of substituents, linking groups, and the like (hereinafter referred to as substituents) indicated by specific symbols, or when a plurality of substituents are specified simultaneously or alternatively, It means that a substituent etc. may mutually be same or different. Even when not specifically stated, when a plurality of substituents and the like are close to each other, they may be connected to each other or condensed to form a ring.

In this specification, about the display of a compound (a resin is included), it uses for the meaning containing its salt and its ion besides the compound itself. Moreover, it is the meaning including the derivative | guide_body which changed the predetermined part in the range with the desired effect.
The substituent in the present specification (the same applies to the linking group) means that the group may have an arbitrary substituent as long as the desired effect is obtained. This is also synonymous for compounds that do not specify substitution / non-substitution.

According to the first aspect and the fourth aspect of the present invention, it is possible to provide a gas separation membrane having at least one of gas permeability and gas separation selectivity under high pressure. ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a gas separation membrane with high at least one of gas permeability under high pressure and gas separation selectivity can be provided. In addition, according to the present invention, it is possible to provide a gas separation membrane module having a gas separation membrane having high gas permeability and gas separation selectivity under high pressure.

According to the second aspect of the present invention, it is possible to provide a gas separation membrane having a high bending resistance and at least one of gas permeability and gas separation selectivity under high pressure. In addition, according to the present invention, it is possible to provide a gas separation membrane module and a gas separation device having a gas separation membrane having high gas permeability and gas separation selectivity under high pressure and high bending resistance. .

According to the third aspect of the present invention, it is possible to provide a gas separation membrane that has high gas permeability under high pressure and gas separation selectivity and is excellent in pressure resistance. In addition, according to the present invention, it is possible to provide a gas separation membrane module and a gas separation device having a gas separation membrane having high gas permeability and gas separation selectivity under high pressure and having excellent pressure resistance. .

It is a schematic diagram which shows an example of the gas separation membrane of this invention. It is a schematic diagram which shows another example of the gas separation membrane of this invention. It is a schematic diagram which shows another example of the gas separation membrane of this invention. In one example of the gas separation membrane of the present invention, the surface of the resin layer containing a compound having a siloxane bond at a depth d (in the direction of the support) from the surface of the resin layer containing a compound having a siloxane bond, and the compound having a siloxane bond It is a schematic diagram for demonstrating the position of the surface of the resin layer containing. It is a schematic diagram which shows an example of the manufacturing method of the gas separation membrane of this invention. (A) The schematic diagram of the polydimethylsiloxane film | membrane which has not been subjected to the oxygen atom permeation treatment step is shown. (B) The schematic diagram of the resin layer containing the compound which has a siloxane bond in an example of the gas separation membrane of this invention is represented. (C) A schematic view of a polydimethylsiloxane film in which oxygen atoms are uniformly introduced in the film thickness direction. It is a schematic diagram which shows another example of the gas separation membrane of this invention.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

The gas separation membrane of the present invention is a gas separation membrane that satisfies any one of the following conditions 1 to 4;
Condition 1: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which a resin layer containing a compound having a siloxane bond satisfies the following

formulas

In General Formula (2) and General Formula (3), R ¹¹ represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3);
Condition 3: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane having a minimum value Si ₀ of 1 to 40% of the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond;
Condition 4: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which a positron lifetime τ3 of a third component is 3.40 to 4.20 ns when a positron is injected at a strength of 1 keV from the surface of a resin layer containing a compound having a siloxane bond.

The method for producing the gas separation membrane of the present invention is not particularly limited, but is preferably a method for producing a gas separation membrane that satisfies the following condition P1 or the following condition P4;
Condition P1: including an oxygen atom permeation treatment step of permeating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm ³ (STP) / min or more and an input power of 23 W or more;
Condition P4: including an oxygen atom infiltration treatment step for infiltrating oxygen atoms into the resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 45 cm ³ (STP) / min or more, and using anode coupling at an input power of 23 W or more.

The mode that satisfies condition 1 is the first mode, the mode that satisfies condition 2 is the second mode, the mode that satisfies condition 3 is the third mode, and the mode that satisfies condition 4 is the fourth mode.
The gas separation membrane of the first aspect that satisfies the condition 1 is preferably manufactured by a method for manufacturing a gas separation membrane that satisfies the condition P1. The gas separation membrane according to the fourth aspect that satisfies the condition 4 is preferably manufactured by a method for manufacturing a gas separation membrane that satisfies the condition P4.
Hereinafter, the first aspect, the second aspect, the third aspect, and the fourth aspect will be described in this order.

{First aspect}
First, the first mode that satisfies condition 1 will be described.

[Gas separation membrane]
The gas separation membrane according to the first aspect of the present invention is a gas separation membrane having a resin layer containing a compound having a siloxane bond, and the resin layers containing the compound having a siloxane bond are represented by the following

formulas

1 and 2. Meet.
Formula 1 0.9 ≧ A / B ≧ 0.55
Formula 2 B ≧ 1.7
In the

formulas

1 and 2, A is a resin containing a compound having the aforementioned siloxane bond at a depth of 10 nm (preferably a depth of 10 nm toward the support) from the surface of the resin layer containing the aforementioned compound having a siloxane bond. Represents the O / Si ratio, which is the ratio of the number of oxygen atoms contained in the layer to the number of silicon atoms, and B represents the number of oxygen atoms on the surface of the resin layer containing the aforementioned compound having a siloxane bond to the number of silicon atoms. The O / Si ratio, which is the ratio.
With such a configuration, the gas separation membrane of the present invention has high gas permeability at high pressure and / or gas separation selectivity.
The higher the A / B ratio in the above formula 1, the more the resin layer containing a compound in which oxygen atoms have a siloxane bond (the resin layer containing a compound having a siloxane bond has a higher gas separation selectivity, so-called separation selectivity. It penetrates to the inside in the thickness direction). In the corona treatment or plasma treatment aiming only at improving the adhesion by modifying the surface, oxygen does not enter sufficiently to have gas separation selectivity from the surface of the resin layer containing a compound having a siloxane bond to a depth of 10 nm. The higher the value of B in Formula 2, the more the surface of the resin layer containing the compound having a siloxane bond is modified and more oxygen atoms are taken in. In the present invention, a resin layer containing a compound having a siloxane bond satisfies the

above formulas

1 and 2 to obtain a gas separation membrane having at least one of gas permeability and gas separation selectivity under high pressure. be able to. Without being bound by any theory, it is considered that separation selectivity is expressed by incorporating oxygen atoms not only into the surface of the resin layer containing a compound having a siloxane bond but also into the thickness direction.
The layer having separation selectivity is a film having a thickness of 0.1 to 30 μm, and the obtained film is oxidized at a temperature of 40 ° C. with a total pressure of 0.5 MPa on the gas supply side. When the pure gas of carbon (CO ₂ ) and methane (CH ₄ ) is supplied, the ratio of the carbon dioxide permeability coefficient (PCO ₂ ) to the methane permeability coefficient (PCH ₄ ) (PCO ₂ / PCH ₄ ) is 1 Means a layer of 5 or more.
Conventionally, a layer having a polyimide compound has often been used as a layer having gas separation membrane separation selectivity, and a polyimide compound is obtained by having a resin layer containing a compound having a siloxane bond subjected to oxygen atom permeation treatment. The structure of the gas separation membrane of the present invention that does not have a layer and has at least one of gas permeability and gas separation selectivity under high pressure has not been known.
Here, the gas permeability and gas separation selectivity of the gas separation membrane are generally in a trade-off relationship. In other words, the gas separation membrane tends to decrease the gas separation selectivity when the gas permeability increases, and the gas separation selectivity tends to increase when the gas permeability decreases. Therefore, it has been difficult for conventional gas separation membranes to increase both gas permeability and gas separation selectivity. In contrast, the gas separation membrane of the present invention can increase both gas permeability and gas separation selectivity.
This is because the gas separation membrane of the present invention has the resin layer 3 containing a compound having a siloxane bond having a structure in which oxygen atoms are introduced with gradation from the surface as shown in FIG. 6B. . Sites where oxygen atoms are introduced form pores by siloxane bonds. In addition, the introduction of oxygen reduces the thermal motion of the polymer. For this reason, the hole which can permeate | transmit many gas selectively has produced | generated. For this reason, unlike a resin layer containing a compound having a siloxane bond before the surface treatment (polydimethylsiloxane membrane 11 not subjected to the oxygen atom permeation treatment step as shown in FIG. 6A), high gas separation is achieved. Selectivity can be obtained.
In addition, polydimethylsilane in which oxygen atoms are uniformly introduced in the film thickness direction as shown in FIG. 6C without using gradation of oxygen atom introduction in the film thickness direction using a CVD (Chemical Vapor Deposition) method or the like. It is possible to produce a siloxane film. When such a membrane is compared with the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention, oxygen atoms are present in the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention. The densely introduced portion is thinner than the polydimethylsiloxane film 12 into which oxygen atoms are uniformly introduced in the film thickness direction. The polydimethylsiloxane membrane in which oxygen atoms are uniformly introduced in the film thickness direction is equal to the thickness of the portion where the oxygen atoms are densely introduced in the resin layer 3 containing a compound having a siloxane bond in the gas separation membrane of the present invention. It is difficult to make it thinner. Therefore, the present invention can achieve extremely high gas permeability and gas separation selectivity.
On the other hand, the gas separation membrane of the present invention can be designed to greatly increase gas permeability and lower gas separation selectivity. In addition, the gas separation membrane of the present invention can be designed to have low gas permeability and greatly increase gas separation selectivity. Even in these cases, if the gas separation membrane of the present invention has the same gas permeability as that of the conventional gas separation membrane, the gas separation membrane of the present invention is more gas selective than the conventional gas separation membrane. In addition, if the gas separation membrane of the present invention has the same gas separation selectivity as the conventional gas separation membrane, the gas separation membrane of the present invention has higher gas permeability than the conventional gas separation membrane. .
The gas separation membrane of the present invention is preferably produced by the method for producing a gas separation membrane of the present invention described later. Since the gas separation membrane obtained by the production method of the present invention has high performance, the gas separation membrane in the product process claim defines a gas separation membrane having high performance. The mechanism of gas separation membrane performance is considered to be determined by the size of the pores in the plane of the layer that contributes to gas separation, but it takes time and money to identify the pore size even with an electron microscope. This is impractical at the time of filing. Instead, the present specification has found that the correlation between the values of A / B and B and the performance of the gas separation membrane is high, and has found that a gas separation membrane having good performance can be provided within this range. Since the range of the gas separation membrane of the product process claim and the range of the gas separation membrane represented by the values of A / B and B are not completely the same, the same range as the product process claim can be specified as a pure product claim. Absent. In addition, if it is the method of giving the energy from the active energy ray equivalent to a plasma process, it is anticipated that the same thing as the gas separation membrane manufactured by the plasma process can be manufactured.
Hereinafter, preferred embodiments of the gas separation membrane of the present invention will be described.

<Configuration>
The gas separation membrane of the present invention is preferably a thin layer composite membrane (sometimes referred to as a gas separation composite membrane), an asymmetric membrane or a hollow fiber, and more preferably a thin layer composite membrane.
Hereinafter, a case where the gas separation membrane is a thin layer composite membrane may be described as a representative example, but the gas separation membrane of the present invention is not limited to the thin layer composite membrane.

A preferred configuration of the gas separation membrane of the present invention will be described with reference to the drawings. An example of the gas separation membrane 10 of the present invention shown in FIG. 1 is a thin layer composite membrane, which is a gas separation membrane having a support 4 and a resin layer 3 containing a compound having a siloxane bond.
Another example of the gas separation membrane 10 of the present invention shown in FIG. 2 is that the support 4 of the resin layer 3 containing a compound having a siloxane bond is added to the support 4 and the resin layer 3 containing a compound having a siloxane bond. Further, a layer (a later-described additional resin layer) 1 containing a polyimide compound is further provided on the opposite side.
The gas separation membrane of the present invention may have only one resin layer containing a compound having a siloxane bond, or may have two or more layers. The gas separation membrane of the present invention preferably has 1 to 5 resin layers containing a compound having a siloxane bond, more preferably 1 to 3 layers, and particularly preferably 1 to 2 layers from the viewpoint of production cost. It is particularly preferable to have only one layer. Another example of the gas separation membrane 10 of the present invention shown in FIG. 3 has two resin layers 3 containing a compound having a siloxane bond.

In the present specification, “on the support” means that another layer may be interposed between the support and the layer having separation selectivity. As for the upper and lower expressions, unless otherwise specified, the direction in which the gas to be separated is supplied is “up” and the direction in which the separated gas is emitted is “down” as shown in FIG. .

In the gas separation membrane of the present invention, the resin layer containing a compound having a siloxane bond satisfies the following formula 1 and the following formula 2.
Formula 1 0.9 ≧ A / B ≧ 0.55
Formula 2 B ≧ 1.7
In

Formulas

1 and 2, A represents the number of silicon atoms in the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. O / Si ratio which is a ratio to the number, and B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
The

above formulas

1 and 2 which are satisfied by the resin layer containing a compound having a siloxane bond will be described with reference to FIG. In FIG. 4, the surface of the resin layer 3 containing a compound having a siloxane bond is represented by reference numeral 6. B in the

formulas

1 and 2 means an O / Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms in the surface 6 of the resin layer containing the compound having a siloxane bond.
Further, in FIG. 4, when d is 10 nm, “the surface of the resin layer containing a compound having a siloxane bond” at a depth of 10 nm from the surface of the resin layer 3 containing a compound having a siloxane bond (toward the support). "A surface parallel to 6 is represented by reference numeral 7" The surface of the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond (toward the support) " It is. A in the above formula 1 represents oxygen in the “surface of the resin layer containing a compound having a siloxane bond at a depth of 10 nm (in the direction of the support) from the surface of the resin layer containing a compound having a siloxane bond” 7. It means the O / Si ratio, which is the ratio of the number of atoms to the number of silicon atoms.

<Support>
The gas separation membrane of the present invention preferably contains a support, and more preferably a resin layer containing a compound having a siloxane bond is formed on the support. The support is preferably a thin and porous material in order to ensure sufficient gas permeability.

In the gas separation membrane of the present invention, the resin layer 3 containing a compound having a siloxane bond may be formed and disposed on the surface or the inner surface of the porous support, and a thin layer can be easily formed by forming on the surface. It can be a composite membrane. By forming the resin layer 3 containing a compound having a siloxane bond on the surface of a porous support, a gas separation membrane having an advantage of having both high gas separation selectivity and high gas permeability and further mechanical strength It can be.

When the gas separation membrane of the present invention is a thin-layer composite membrane, the thin-layer composite membrane is obtained by applying a coating liquid (dope) that forms the resin layer 3 containing the compound having a siloxane bond on the surface of the porous support. It is preferably formed by coating (in this specification, coating means to include an aspect of being attached to the surface by dipping). Specifically, the support preferably has a porous layer (Porous Layer) on the side of the resin layer 3 containing a compound having a siloxane bond, and is porous on the side of the resin layer 3 containing a compound having a siloxane bond. More preferably, it is a laminate of a non-woven fabric (Non-Woven).

The porous layer preferably applied to the support is not particularly limited as long as it has the purpose of meeting the provision of mechanical strength and high gas permeability, and may be either organic or inorganic material. However, it is preferably a porous film of an organic polymer, and its thickness is 1 to 3000 μm, preferably 5 to 500 μm, more preferably 5 to 150 μm. The porous structure of this porous layer usually has an average pore diameter of 10 μm or less, preferably 0.5 μm or less, more preferably 0.2 μm or less, and a porosity of preferably 20 to 90%. Preferably, it is 30 to 80%. The molecular weight cutoff of the porous layer is preferably 100,000 or less, and the gas permeability is 3 × 10 ⁻⁵ cm ³ (STP; STP is an abbreviation for Standard Temperature and Pressure). ) / Cm ² · cm · sec · cmHg (30 GPU; GPU is an abbreviation for Gas Permeation Unit). Examples of the material for the porous layer include conventionally known polymers such as polyolefin resins such as polyethylene and polypropylene, fluorine-containing resins such as polytetrafluoroethylene, polyvinyl fluoride, and polyvinylidene fluoride, polystyrene, cellulose acetate, and polyurethane. And various resins such as polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, and polyaramid. The shape of the porous layer may be any shape such as a flat plate shape, a spiral shape, a tubular shape, and a hollow fiber shape.

In the thin-layer composite film, it is preferable that a woven fabric, a nonwoven fabric, a net, or the like is provided to give mechanical strength to the lower portion of the porous layer disposed on the resin layer 3 side containing the compound having a siloxane bond, Nonwoven fabrics are preferably used from the viewpoint of film forming properties and cost. As the nonwoven fabric, fibers made of polyester, polypropylene, polyacrylonitrile, polyethylene, polyamide or the like may be used alone or in combination. The nonwoven fabric can be produced, for example, by making a main fiber and a binder fiber uniformly dispersed in water using a circular net or a long net, and drying with a dryer. Moreover, it is also preferable to apply a heat treatment by sandwiching a non-woven fabric between two rolls for the purpose of removing fluff and improving mechanical properties.

<Resin layer containing a compound having a siloxane bond>
The gas separation membrane of the present invention has a resin layer containing a compound having a siloxane bond.
In the gas separation membrane of the present invention, the resin layer containing the compound having a siloxane bond satisfies the following formula 1 and the following formula 2.
Formula 1 0.9 ≧ A / B ≧ 0.55
Formula 2 B ≧ 1.7
In

Formulas

1 and 2, A represents the number of silicon atoms in the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. O / Si ratio which is a ratio to the number, and B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
In the resin layer containing the compound having a siloxane bond, A / B is preferably 0.60 or more, more preferably A / B is 0.63 or more, and A / B is 0.65 or more. It is particularly preferred that
In the resin layer containing the compound having a siloxane bond, B is preferably 1.95 or more.

In the present specification, the ratio of the number of oxygen atoms to the number of silicon atoms in each surface of a resin layer containing a compound having a siloxane bond, that is, a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond. O / Si ratio (A), which is the ratio of the number of oxygen atoms of the resin layer containing a compound having a ratio to the number of silicon atoms, and the number of oxygen atoms on the surface of the resin layer containing a compound having a siloxane bond The O / Si ratio (B), which is the ratio to the number, can be measured as a relative amount. Oxygen contained in the resin layer containing a compound having a siloxane bond at a depth of 30 nm and 50 nm from the surface of the resin layer containing a compound having a siloxane bond (preferably a depth of 30 nm in the direction of the support and 50 nm in the direction of the support) The O / Si ratio (C), which is the ratio of the number of atoms to the number of silicon atoms, can also be measured as a relative amount in the same manner as the aforementioned O / Si ratio (A) and O / Si ratio (B). The carbon / silicon ratio, which is the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond, is also the O / Si ratio (A) or the O / Si ratio (B) described above. Similarly, it can be measured as a relative amount.

O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms; The O / Si ratio (B), which is the ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond, is calculated using ESCA (Electron Spectroscopy FOR Chemical Analysis). Similarly, the carbon / silicon ratio, which is the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond, is also calculated.
A porous support formed with a resin layer containing a compound having a siloxane bond was obtained from Physical Electronics, Inc. Included in Quantera SXM manufactured by the company, X-ray source: Al—Kα ray (1490 eV, 25 W, diameter of 100 μm), measurement area: 300 μm × 300 μm, Pass Energy 55 eV, Step 0.05 eV, including a compound having a siloxane bond An O / Si ratio (B), which is a ratio of the number of oxygen atoms on the surface of the resin layer to the number of silicon atoms, is calculated.
Subsequently, an O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms (A ) Is performed with C ₆₀ ions.
Specifically, Physical Electronics, Inc. At Company Ltd. QuanteraSXM comes _{C 60} ion gun, ion beam intensity _C ⁶⁰ +: 10 keV, and 10 nA, to 10nm etching an area of 2 mm × 2 mm. An ESCA apparatus is used for this film to calculate an O / Si ratio (A) that is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond. The depth of the resin layer containing the compound having a siloxane bond from the surface of the resin layer containing the compound having a siloxane bond is calculated from the etching rate of 10 nm / min of the resin layer material containing the compound having a siloxane bond. As this value, an optimal value is appropriately used depending on the material.
O / Si ratio (A) which is the ratio of the number of oxygen atoms of the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond to the number of silicon atoms Then, the value of A / B is calculated from the O / Si ratio (B) which is the ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
Similar to the O / Si ratio (A), which is the ratio of the number of oxygen atoms to the number of silicon atoms in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. O / Si ratio (C), which is the ratio of the number of oxygen atoms in the resin layer containing a compound having a siloxane bond at a depth of 30 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms Ask for. Further, the value of C / B is calculated from the O / Si ratio (B) and the O / Si ratio (C).

In this specification, the surface of the resin layer containing the compound having a siloxane bond described above is O 2 when the O / Si ratio is measured from the surface of the gas separation membrane (preferably the surface opposite to the support). / Si ratio is the maximum, and the number of silicon atoms is 3% (atomic%) or more.
When there is no other layer on the surface of the resin layer containing a compound having a siloxane bond, oxygen atoms of the resin layer containing the compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond When the O / Si ratio is measured from the surface of the gas separation membrane in the same manner as the method for obtaining the O / Si ratio (A), which is the ratio of the number to the number of silicon atoms, the O / Si ratio is maximum. And a plane containing 3% (atomic%) or more of silicon atoms is specified.
As a result, in the above-described method, a compound having a siloxane bond in a state where a resin layer containing a compound having a siloxane bond is formed on the porous support (a state in which no other layer (for example, a layer containing polyimide) is present). The surface of the resin layer containing “the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. It is confirmed that it is “surface”.

When the surface of the resin layer containing a compound having a siloxane bond has another layer (for example, a layer containing polyimide), the surface of the resin layer containing a compound having a siloxane bond (that is, the O / Si ratio is set to the above-mentioned gas separation membrane). The depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond, the surface having the maximum O / Si ratio when measured from the surface and containing 3% (atomic%) or more of silicon atoms) The resin layer containing a compound having a siloxane bond in is obtained by a method similar to the method for obtaining the O / Si ratio (A), which is the ratio of the number of oxygen atoms to the number of silicon atoms.
As a result, in the above-described method, a compound having a siloxane bond in a state where a resin layer containing a compound having a siloxane bond is formed on the porous support (a state in which no other layer (for example, a layer containing polyimide) is present). The surface of the resin layer containing “the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. Surface ". Specifically, “comprising a compound having a siloxane bond in a state in which a resin layer containing a compound having a siloxane bond is formed on the porous support (without any other layer (for example, a layer containing polyimide)). From “the surface of the resin layer”, “the surface where the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane and the number of silicon atoms is 3% (atomic%) or more” "Means.

When the amount of oxygen atoms per unit area on each surface of the resin layer containing a compound having a siloxane bond is measured as a relative amount, the resin layer containing a compound having a siloxane bond is a resin containing a compound having a siloxane bond. The O / Si (A) ratio, which is the ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the layer to the number of silicon atoms, exceeds 1.0 and is 3.0. The following is preferable, 1.1 to 2.4 is more preferable, and 1.3 to 2.35 is particularly preferable.

The O / Si ratio (C), which is the ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 30 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms, is It is preferably 1.0 to 2.4, and particularly preferably 1.05 to 2.3.
The value of C / B is preferably 0.50 to 0.95, more preferably 0.50 to 0.90, and particularly preferably 0.50 to 0.85.

In the gas separation membrane of the present invention, the ratio of the number of carbon atoms to the number of silicon atoms (carbon / silicon ratio) on the surface of the resin layer containing a compound having a siloxane bond is preferably 1.6 or less. 0.1 to 1.3 is more preferable, and 0.1 to 1.1 is particularly preferable.

In the gas separation membrane of the present invention, the gel fraction of the gas separation membrane is preferably 45% or more from the viewpoint of enhancing storage resistance. The wet heat durability of the gas separation membrane can be improved by controlling the gel fraction of the gas separation membrane. As a result, the performance of the gas separation membrane is stabilized with respect to the environment at the time of storage, so that it does not deviate from the range of the gas separation performance defined in the specifications at the time of shipment. Moreover, the yield after shipment improves.
In the gas separation membrane, the gel fraction of the gas separation membrane is more preferably greater than 55% from the viewpoint of enhancing the wet heat (transport) resistance in addition to the storage resistance, and particularly preferably 70% or more. Since the performance of the gas separation membrane is stable with respect to the humid heat environment during transportation, it does not deviate from the range of the gas separation performance defined in the specifications at the time of shipment. Moreover, the yield after shipment improves.
In this specification, the value measured by the following method is adopted as the gel fraction of the gas separation membrane. A sample is prepared by applying and curing a resin layer containing a compound having a siloxane bond of 10 μm or less on a porous support. The signal intensity Xa of the Si component is measured for the sample by XRF measurement. On the other hand, a resin layer containing a compound having a siloxane bond is applied and cured, and then immersed in a chloroform solvent for 24 hours to prepare a sample from which eluted components are extracted. Thereafter, the XRF measurement of the sample from which the eluted component is extracted is performed, and the signal intensity Xb of the Si component is measured. Xb / Xa * 100% was defined as the gel fraction. The solvent used for extraction may be other than chloroform, and examples thereof include hexane.
In the gas separation membrane, the value represented by the following formula of the resin layer containing the compound having a siloxane bond is preferably 5000 nm or less, more preferably 900 nm or less, and particularly preferably 100 to 900 nm. .
formula:
Thickness of resin layer containing compound having siloxane bond × (1−gel fraction / 100)

In the gas separation membrane, a resin layer containing a compound having a siloxane bond that satisfies the above conditions is preferably 50% or more, more preferably 70% or more, and particularly preferably 90% or more.
In the plane of the gas separation membrane, there may be other regions other than the resin layer containing a compound having a siloxane bond that satisfies the above. Examples of other regions include a region where an adhesive or a pressure-sensitive adhesive is provided, a region where a specific treatment (preferably oxygen atom permeation treatment) is not sufficient for a resin layer containing a compound having a siloxane bond, and the like. be able to.

The resin layer containing the compound having a siloxane bond includes a compound having a siloxane bond. The compound having a siloxane bond may be “a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom”. The compound having a siloxane bond may be a “compound having a siloxane bond and having a repeating unit”, and among them, a compound having a polysiloxane unit is preferable.

In the gas separation membrane of the present invention, the compound having a siloxane bond described above preferably has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3).

In General Formula (2) and General Formula (3), R ¹¹ represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3).

R ¹¹ in the general formula (2) is preferably a hydroxyl group, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group or a carboxyl group, and a hydroxyl group, an alkyl group having 1 or more carbon atoms, amino It is preferably a group, an epoxy group or a carboxyl group, more preferably a hydroxyl group, an alkyl group having 1 or more carbon atoms, an epoxy group or a carboxyl group.
The hydroxyl group and carboxyl group represented by R ¹¹ in the general formula (2) may form an arbitrary salt.
In general formula (2) and general formula (3), * represents a binding site with # in general formula (2) or general formula (3), and # in general formula (2) or general formula (3) Represents the binding site of *. In addition, * may be a bonding site with an oxygen atom in the general formula (1) described later, and # may be a bonding site with a silicon atom in the general formula (1) described later.

In the gas separation membrane of the present invention, the compound having a siloxane bond described above preferably has a repeating unit represented by the following general formula (1).
General formula (1)

In general formula (1), each R independently represents a hydrogen atom, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group, a fluorinated alkyl group, a vinyl group, an alkoxy group or a carboxyl group, and n is Represents an integer of 2 or more.
When such a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond, and a resin layer containing a compound having a siloxane bond satisfying the

above formulas

1 and 2 is formed under high pressure High gas permeability and gas separation selectivity can be exhibited.
Further, when a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond and a resin layer containing a compound having a siloxane bond satisfying the above-described

formulas

1 and 2 is formed, it is not limited to any theory. Although it does not do, not only the surface of the resin layer containing a compound having a siloxane bond in the oxygen atom, but also the inside in the thickness direction is incorporated into the SiOx composition, so high gas permeability and gas separation under high pressure It is thought that selectivity is expressed. In particular, even when polydimethylsiloxane, which is known to have high gas permeability, is used as a resin layer containing a compound having a siloxane bond that satisfies the above formula 1, high gas permeability and separation under high pressure. Selectivity can be expressed. Not only the surface of the resin layer containing the compound having a siloxane bond but also the surface of the resin layer containing the compound having a siloxane bond and the thickness of the resin layer containing the compound having a siloxane bond. It is preferable that the compound having a siloxane bond has at least a repeating unit represented by the general formula (2) or a repeating unit represented by the general formula (3) inside in the direction.

R in the general formula (1) is preferably an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group or a carboxyl group in the general formula (1). Of these, an alkyl group, an amino group, an epoxy group or a carboxyl group is more preferred, and an alkyl group having 1 or more carbon atoms, an epoxy group or a carboxyl group is particularly preferred.
The alkyl group having 1 or more carbon atoms represented by R in the general formula (1) is preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, or a propyl group, and particularly preferably a methyl group. The alkyl group having 1 or more carbon atoms represented by R may be linear, branched or cyclic.
As the aryl group represented by R in the general formula (1), an aryl group having 6 to 20 carbon atoms is preferable, and a phenyl group is particularly preferable.
The fluorinated alkyl group represented by R in the general formula (1) is preferably a fluorinated alkyl group having 1 to 10 carbon atoms, more preferably a fluorinated alkyl group having 1 to 3 carbon atoms, and particularly preferably a trifluoromethyl group. . The fluorinated alkyl group represented by R may be linear, branched or cyclic.
The alkoxy group represented by R in the general formula (1) is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably a methoxy group, an ethoxy group, or a propyloxy group, and particularly preferably a methoxy group. The alkoxy group having 1 or more carbon atoms represented by R may be linear, branched or cyclic.
In the general formula (1), n represents an integer of 2 or more, preferably 40 to 800, more preferably 50 to 700, and particularly preferably 60 to 500.

The compound having a siloxane bond having a repeating unit represented by the general formula (1) may have an arbitrary substituent at the molecular end other than the repeating unit represented by the general formula (1). Examples and preferred ranges of substituents that may be present at the molecular ends of the compound having a siloxane bond having a repeating unit represented by the general formula (1) are the examples and preferred ranges of R in the general formula (1) It is the same.

In the gas separation membrane of the present invention, the surface of the resin layer containing the compound having a siloxane bond is represented by the repeating unit represented by the general formula (1) and at least the general formula (2). Or a compound having a siloxane bond having a repeating unit represented by the general formula (3).
In the gas separation membrane of the present invention, the above general formula of the repeating unit represented by the above general formula (3) in the above compound having the siloxane bond included in the surface of the resin layer containing the above compound having the siloxane bond. The ratio of the repeating unit represented by (2) and the repeating unit represented by the general formula (1) is preferably 100 to 600 mol%, more preferably 200 to 600 mol%, Particularly preferred is ˜600 mol%.

In the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 10 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the compound having the siloxane bond described above is included in the resin layer including the compound having the siloxane bond at a depth of 10 nm from the surface of the resin layer including the compound having the siloxane bond. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 3.0 to 500 mol%. It is preferably 3.5 to 450 mol%, more preferably 4.0 to 400 mol%.
Furthermore, in the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 30 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the above-described compound having a siloxane bond included in the resin layer containing the compound having the siloxane bond at a depth of 30 nm from the surface of the resin layer containing the compound having the siloxane bond described above. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 2.0 to 400 mol%. Preferably, it is 2.5 to 350 mol%, more preferably 3.0 to 300 mol%.

The compound having a siloxane bond used in the resin layer containing a compound having a siloxane bond preferably has a polymerizable functional group. Examples of such functional groups include epoxy groups, oxetane groups, carboxyl groups, amino groups, hydroxyl groups, and thiol groups. The resin layer containing a compound having a siloxane bond more preferably contains an epoxy group, an oxetane group, a carboxyl group, and a compound having a siloxane bond having two or more of these groups. Such a resin layer containing a compound having a siloxane bond is preferably formed on the aforementioned support by curing the radiation curable composition by irradiation with radiation.

The compound having a siloxane bond used in the resin layer containing a compound having a siloxane bond may be a polymerizable dialkylsiloxane formed from a partially crosslinked radiation-curable composition having a dialkylsiloxane group. The polymerizable dialkylsiloxane is a monomer having a dialkylsiloxane group, a polymerizable oligomer having a dialkylsiloxane group, or a polymer having a dialkylsiloxane group. Examples of the dialkylsiloxane group include a group represented by — {O—Si (CH ₃ ) ₂ } _n2 — (n2 is, for example, 1 to 100). A poly (dialkylsiloxane) compound having a vinyl group at the terminal can also be preferably used.

Examples of the compound having a siloxane bond used for a resin layer material containing a compound having a siloxane bond include polydimethylsiloxane (hereinafter also referred to as PDMS), polydiphenylsiloxane (Polydiphenylsiloxane), polydi (trifluoropropyl) siloxane (Polydi). (Trifluoropropyl) siloxane), polymethyl (3,3,3-trifluoropropyl) siloxane (Poly [methyl (3,3,3-trifluoropropyl) siloxane]), poly (1-trimethylsilyl-1-propyne) (hereinafter, referred to as “poly (1-trimethylsilyl-1-propyne)”) At least one selected from PTMSP), polydimethylsiloxane or poly (1-trimethylsilyl-1-propyne) Mukoto more preferably, it is particularly preferred that it include a polydimethylsiloxane.

A commercially available material can be used as the compound having a siloxane bond used for the material of the resin layer containing a compound having a siloxane bond. For example, as a compound having a siloxane bond used for a resin layer containing a compound having a siloxane bond For example, UV9300 (polydimethylsiloxane (PDMS) manufactured by Momentive), X-22-162C (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be preferably used.
As another material of the resin layer containing a compound having a siloxane bond, UV9380C (bis (4-dodecylphenyl) iodonium = hexafluoroantimonate manufactured by Momentive) or the like can be preferably used.

The material of the resin layer containing a compound having a siloxane bond can be prepared as a composition containing an organic solvent when forming a resin layer containing a compound having a siloxane bond, and is preferably a curable composition. The organic solvent that can be used when forming the resin layer containing the compound having a siloxane bond is not particularly limited, and examples thereof include n-heptane.

(Characteristic)
Although there is no restriction | limiting in particular as a film thickness of the resin layer containing the compound which has a siloxane bond, From a viewpoint of the ease of film forming that the film thickness of the resin layer containing the compound which has the above-mentioned siloxane bond is 0.1 micrometer or more. The thickness is preferably 0.1 to 5 μm, more preferably 0.1 to 4 μm, and particularly preferably 0.3 to 3 μm. The film thickness of the resin layer containing a compound having a siloxane bond can be determined by SEM.
The film thickness of the resin layer containing the compound having a siloxane bond can be controlled by adjusting the coating amount of the curable composition.

<Additional resin layer>
The gas separation membrane of the present invention may include an additional resin layer in addition to the above-described resin layer containing a compound having a siloxane bond (hereinafter referred to as an additional resin layer).

The resin included in the additional resin layer is listed below, but is not limited thereto. Specifically, the above-described compounds having a siloxane bond, polyimides, polyamides, celluloses, polyethylene glycols, and polybenzoxazoles are preferable, and the above-described compounds having a siloxane bond, polyimide, polybenzoxazole, and More preferably, it is at least one selected from cellulose acetate. It is particularly preferable that the gas separation membrane of the present invention has a resin layer containing a compound having a siloxane bond as described above, and further has a layer containing a polyimide compound as an additional resin layer.

The polyimide compound is preferably a polyimide having a reactive group.

In the following, the case where the resin of the additional resin layer is a polyimide having a reactive group may be described as a representative example, but the present invention may be used when the polymer having a reactive group is a polyimide having a reactive group. It is not limited.

The polyimide having a reactive group that can be used in the present invention will be described in detail below.
In the present invention, the polyimide compound having a reactive group is a polymer having a reactive group, a polyimide unit and a reactive group (preferably a nucleophilic reactive group in the side chain, more preferably a carboxyl group, And a repeating unit having an amino group or a hydroxyl group.
More specifically, the polymer having a reactive group is represented by at least one repeating unit represented by the following formula (I) and the following formula (III-a) or (III-b): It is preferable to include at least one repeating unit.
Furthermore, the polymer having a reactive group includes at least one repeating unit represented by the following formula (I) and at least one repeating unit represented by the following formula (II-a) or (II-b): And at least one repeating unit represented by the following formula (III-a) or (III-b).
The polyimide having a reactive group that can be used in the present invention may contain a repeating unit other than the above repeating units, and the number of moles thereof is the sum of the number of moles of each repeating unit represented by the above formulas. When 100 is 100, it is preferably 20 or less, more preferably 0 to 10. It is particularly preferable that the polyimide having a reactive group that can be used in the present invention consists only of each repeating unit represented by the following formulas.

In the formula (I), R represents a group having a structure represented by any of the following formulas (Ia) to (Ih). In the following formulas (Ia) to (Ih), * represents a bonding site with the carbonyl group of the formula (I). R in the formula (I) may be referred to as a mother nucleus, and the mother nucleus R is preferably a group represented by the formula (Ia), (Ib) or (Id), A group represented by (Ia) or (Id) is more preferred, and a group represented by (Ia) is particularly preferred.

・ X ¹ , X ² , X ³
X ¹ , X ² and X ³ represent a single bond or a divalent linking group. As these divalent linking groups, —C (R ^x ) ₂ — (R ^x represents a hydrogen atom or a substituent. When R ^x is a substituent, they may be linked to each other to form a ring) , —O—, —SO ₂ —, —C (═O) —, —S—, —NR ^Y — (R ^Y is a hydrogen atom, an alkyl group (preferably a methyl group or an ethyl group) or an aryl group (preferably Phenyl group)), or a combination thereof, and a single bond or —C (R ^x ) ₂ — is more preferable. When R ^x represents a substituent, specific examples thereof include the substituent group Z described below. Among them, an alkyl group is preferable, an alkyl group having a halogen atom as a substituent is more preferable, and trifluoromethyl is particularly preferable. . In the present specification, when “may be linked to each other to form a ring”, it may be bonded by a single bond, a double bond or the like to form a cyclic structure, It may form a condensed ring structure.

・ L
L represents —CH ₂ ═CH ₂ — or —CH ₂ —, preferably —CH ₂ ═CH ₂ —.

・ R ¹ , R ²
R ¹ and R ² represent a hydrogen atom or a substituent. As the substituent, any one selected from the substituent group Z shown below can be used. R ¹ and R ² may be bonded to each other to form a ring.

R ¹ and R ² are preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom.

・ R ³
R ³ represents an alkyl group or a halogen atom. Preferable examples of these alkyl groups and halogen atoms are the same as the preferable ranges of the alkyl groups and halogen atoms defined in Substituent group Z described later. L1 representing the number of R ³ is an integer of 0 to 4, preferably 1 to 4, and more preferably 3 to 4. R ³ is preferably an alkyl group, and more preferably a methyl group or an ethyl group.

・ R ⁴ , R ⁵
R ⁴ and R ^{5 each} represents an alkyl group or a halogen atom, or a group that forms a ring together with X ² by being linked to each other. Preferable examples of these alkyl groups and halogen atoms are the same as the preferable ranges of the alkyl groups and halogen atoms defined in Substituent group Z described later. The structure in which R ⁴ and R ⁵ are linked is not particularly limited, but a single bond, —O— or —S— is preferable. M1 and n1 representing the number of R ⁴ and R ⁵ are integers of 0 to 4, preferably 1 to 4, and more preferably 3 to 4.
When R ⁴ and R ⁵ are alkyl groups, they are preferably methyl groups or ethyl groups, and trifluoromethyl is also preferable.

・ R ⁶ , R ⁷ , R ⁸
R ⁶ , R ⁷ and R ⁸ represent a substituent. Here, R ⁷ and R ⁸ may be bonded to each other to form a ring. L2, m2, and n2 representing the number of these substituents are integers of 0 to 4, preferably 0 to 2, and more preferably 0 to 1.

・ J ¹
J ¹ represents a single bond or a divalent linking group. As the linking group, * —COO ^— N ⁺ R ^b R ^c R ^d — ** (R ^b to R ^d are a hydrogen atom, an alkyl group, and an aryl group, and preferred ranges thereof are those described in Substituent Group Z below. _{^{^{^{^{synonymous), * -. SO 3 -}}}}} N + R e R f R g - ** (R e ~ R g is a hydrogen atom, an alkyl group, an aryl group, its preferred range is below substituent group Z And an alkylene group or an arylene group. * Represents the binding site on the phenylene group side, and ** represents the opposite binding site. J ¹ is preferably a single bond, a methylene group or a phenylene group, and particularly preferably a single bond.

・ A ¹
A ¹ is not particularly limited as long as it is a group capable of undergoing a crosslinking reaction, but is preferably a nucleophilic reactive group, and includes a carboxyl group, an amino group, a hydroxyl group, and —S (═O) ₂ OH. It is more preferable to show the group selected. The preferred range of the amino group described above is synonymous with the preferred range of the amino group described in Substituent Group Z below. A ¹ is particularly preferably a carboxyl group, an amino group or a hydroxyl group, more particularly preferably a carboxyl group or a hydroxyl group, and particularly preferably a carboxyl group.

Substituent group Z
An alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl) , N-decyl, n-hexadecyl), a cycloalkyl group (preferably a cycloalkyl group having 3 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, particularly preferably 3 to 10 carbon atoms, such as cyclopropyl, Cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably an alkenyl group having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as vinyl, allyl, -Butenyl, 3-pentenyl, etc.), alkynyl group (preferably having 2 to 30 carbon atoms, more preferably An alkynyl group having 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl and 3-pentynyl, and an aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 carbon atoms). To 20 and particularly preferably an aryl group having 6 to 12 carbon atoms, such as phenyl, para-methylphenyl, naphthyl, anthranyl, etc.), amino group (amino group, alkylamino group, arylamino group, hetero A cyclic amino group, preferably an amino group having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzyl Amino, diphenylamino, ditolylamino, etc.), an alkoxy group (preferably having a carbon number) To 30 and more preferably an alkoxy group having 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), an aryloxy group (preferably Is an aryloxy group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyloxy, 1-naphthyloxy, 2-naphthyloxy and the like. A heterocyclic oxy group (preferably a heterocyclic oxy group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc. ),

An acyl group (preferably an acyl group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), alkoxy A carbonyl group (preferably an alkoxycarbonyl group having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), aryloxy A carbonyl group (preferably an aryloxycarbonyl group having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl), an acyloxy group ( Preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, especially Preferably, it is an acyloxy group having 2 to 10 carbon atoms, such as acetoxy, benzoyloxy, etc.), an acylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably carbon atoms). An acylamino group of 2 to 10, for example, acetylamino, benzoylamino and the like),

An alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryl Oxycarbonylamino group (preferably an aryloxycarbonylamino group having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonylamino group) A sulfonylamino group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino, benzenesulfonylamino, etc.), a sulfamoyl group (Preferably 0-30 carbon atoms, more preferred 0 to 20 carbon atoms, particularly preferably a sulfamoyl group having 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, and the like phenylsulfamoyl.),

A carbamoyl group (preferably a carbamoyl group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl and the like. ), An alkylthio group (preferably an alkylthio group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio and ethylthio), an arylthio group ( Preferably, it is an arylthio group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic thio group (preferably having 1 carbon atom) To 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 1 carbon atoms. Of a heterocyclic thio group, e.g. pyridylthio, 2-benzoxazolyl thio, and 2-benzthiazolylthio the like.),

A sulfonyl group (preferably a sulfonyl group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), a sulfinyl group (preferably A sulfinyl group having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably having 1 carbon atom) -30, more preferably a ureido group having 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), a phosphoramide group (preferably having a carbon number) A phosphoric acid amide group having 1 to 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, For example, diethyl phosphate amide, phenyl phosphate amide, etc.), hydroxyl group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom, more preferably fluorine atom) ,

A cyano group, a sulfo group, a carboxyl group, an oxo group, a nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group (preferably a 3- to 7-membered heterocyclic group, even an aromatic heterocyclic ring The hetero atom may be a non-aromatic hetero ring, and examples of the hetero atom constituting the hetero ring include a nitrogen atom, an oxygen atom and a sulfur atom, preferably 0 to 30 carbon atoms, more preferably 1 to 12 carbon atoms. Specific examples thereof include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl and the like, and a silyl group (preferably). Is a silica having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms. Groups such as trimethylsilyl and triphenylsilyl), silyloxy groups (preferably silyloxy groups having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyloxy, triphenylsilyloxy, etc.). These substituents may be further substituted with any one or more substituents selected from the above substituent group Z.
In the present invention, when one structural site has a plurality of substituents, these substituents are connected to each other to form a ring, or condensed with a part or all of the above structural sites to form an aromatic group. A ring or an unsaturated heterocyclic ring may be formed.

In the polyimide compound that can be used in the present invention, the ratio of each repeating unit represented by the aforementioned formula (I), (II-a), (II-b), (III-a), (III-b) is as follows: It is not particularly limited, and is appropriately adjusted in consideration of gas permeability and gas separation selectivity according to the purpose of gas separation (recovery rate, purity, etc.).

In the polyimide having a reactive group that can be used in the present invention, the formulas (III-a) and (III-b) with respect to the total number of moles (E _II ) of each repeating unit of the formulas (II-a) and (II-b) The ratio (E _II / E _III ) of the total number of moles (E _III ) of each repeating unit is preferably 5/95 to 95/5, more preferably 10/90 to 80/20, More preferably, it is 20/80 to 60/40.

The molecular weight of the polyimide having a reactive group that can be used in the present invention is preferably 10,000 to 1,000,000 as a weight average molecular weight, more preferably 15,000 to 500,000, Preferably, it is 20,000 to 200,000.

Unless otherwise specified, the molecular weight and the degree of dispersion are values measured using a GPC (gel filtration chromatography) method, and the molecular weight is a weight average molecular weight in terms of polystyrene. The gel packed in the column used in the GPC method is preferably a gel having an aromatic compound as a repeating unit, and examples thereof include a gel made of a styrene-divinylbenzene copolymer. Two to six columns are preferably connected and used. Examples of the solvent used include ether solvents such as tetrahydrofuran and amide solvents such as N-methylpyrrolidinone. The measurement is preferably performed at a solvent flow rate in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, the apparatus is not loaded and the measurement can be performed more efficiently. The measurement temperature is preferably 10 to 50 ° C, most preferably 20 to 40 ° C. Note that the column and carrier to be used can be appropriately selected according to the physical properties of the polymer compound that is symmetrical to the measurement.

The polyimide having a reactive group that can be used in the present invention can be synthesized by condensation polymerization of a specific bifunctional acid anhydride (tetracarboxylic dianhydride) and a specific diamine. As the method, the method described in a general book (for example, published by NTS, edited by Ikuo Imai, Rikio Yokota, latest polyimide-basics and applications-pages 3-49, etc.) is appropriately selected. be able to.

Specific examples of preferred polyimides having a reactive group that can be used in the present invention are listed below, but the present invention is not limited thereto. In the following formulae, “100”, “x”, and “y” represent copolymerization ratios (molar ratios). Examples of “x”, “y” and weight average molecular weight are shown in Table 1 below. In the polyimide compound that can be used in the present invention, y is preferably not 0.

Furthermore, a polymer (P-101) having a copolymerization ratio x of 20 and y of 80 in the above exemplified polyimide compound P-100 can also be preferably used.

In addition, when the resin of the additional resin layer is polyimide, more specifically, the product name P84 and the product from Matrimid 5218 and HP Polymers GmbH sold under the Matrimid (registered trademark) trademark by Huntsman Advanced Materials, respectively. P84 or P84HT sold under the name P84HT is also preferable.

On the other hand, as the resin of the additional resin layer other than polyimide, celluloses such as cellulose acetate, cellulose triacetate, cellulose acetate butyrate, cellulose propionate, ethyl cellulose, methyl cellulose, and nitrocellulose can be selected. As celluloses that can be used in the additional resin layer, the substitution degree of all acyl groups is preferably 2.0 to 2.7. Cellulose acetate commercially available as cellulose acetate L-40 (acyl group substitution degree 2.5, manufactured by Daicel Corporation) can also be preferably used.

As other resin of the additional resin layer, polyethylene glycols such as a polymer obtained by polymerizing polyethylene glycol # 200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), polymers described in JP-T-2010-513021, and the like are selected. be able to.

Other additional resin layers may be inserted between the support and the resin layer containing a compound having a siloxane bond. Examples of other additional resin layers include adjustment of hydrophilicity / hydrophobicity such as PVA.

(Characteristic)
The film thickness of the additional resin layer is preferably a thin film as much as possible under the condition of imparting high gas permeability while maintaining mechanical strength and gas separation selectivity.

From the viewpoint of enhancing gas permeability, the additional resin layer other than the resin layer containing the compound having a siloxane bond of the gas separation membrane of the present invention is preferably a thin layer. The thickness of the additional resin layer other than the resin layer containing the compound having a siloxane bond is usually 10 μm or less, preferably 3 μm or less, particularly preferably 1 μm or less, and 0.3 μm or less. Is more particularly preferable, and it is even more particularly preferable that it is 0.2 μm or less.
The thickness of the additional resin layer other than the resin layer containing the compound having a siloxane bond is usually 0.01 μm or more, and is practically preferably 0.03 μm or more from the viewpoint of film formation, More preferably, it is 1 μm or more.

<Protective layer>
The gas separation membrane of the present invention may be provided with a protective layer (Protective Layer) formed on the resin layer containing the compound having a siloxane bond or on the additional resin layer. The protective layer is a layer placed on the resin layer containing the compound having a siloxane bond or the additional resin layer. It is possible to prevent unintentional contact between the resin layer containing the compound having a siloxane bond or the additional resin layer and other materials during handling or use.

(material)
Although there is no restriction | limiting in particular as the material of the above-mentioned protective layer, The preferable range of the material used for the above-mentioned protective layer is the same as the range of the preferable material used for the resin layer containing the compound which has a siloxane bond. In particular, the protective layer is preferably at least one selected from polydimethylsiloxane, poly (1-trimethylsilyl-1-propyne) and polyethylene oxide, and polydimethylsiloxane or poly (1-trimethylsilyl-1-propyne). Is more preferable, and polydimethylsiloxane is particularly preferable.

(Characteristic)
The film thickness of the protective layer is preferably 20 nm to 3 μm, more preferably 50 nm to 2 μm, and particularly preferably 100 nm to 1 μm.

<Characteristics and applications>
The separation membrane of the present invention can be suitably used as a gas separation recovery method and a gas separation purification method. For example, hydrogen, helium, carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen, nitrogen, ammonia, sulfur oxides, nitrogen oxides, hydrocarbons such as methane and ethane, unsaturated hydrocarbons such as propylene, tetrafluoroethane, etc. A gas separation membrane capable of efficiently separating a specific gas from a gas mixture containing a gas such as a perfluoro compound.
The gas separation membrane of the present invention is preferably a gas separation membrane for separating at least one acidic gas from a gas mixture of acidic gas and non-acidic gas. Examples of the acid gas include carbon dioxide, hydrogen sulfide, carbonyl sulfide, sulfur oxide (SOx), and nitrogen oxide (NOx), and carbon dioxide, hydrogen sulfide, carbonyl sulfide, sulfur oxide (SOx), and nitrogen. It is preferably at least one selected from oxides (NOx), more preferably carbon dioxide, hydrogen sulfide or sulfur oxide (SOx), and particularly preferably carbon dioxide.
The aforementioned non-acidic gas is preferably at least one selected from hydrogen, methane, nitrogen, and carbon monoxide, more preferably methane and hydrogen, and particularly preferably methane.
The gas separation membrane of the present invention is preferably a gas separation membrane that selectively separates carbon dioxide from a gas mixture containing carbon dioxide / hydrocarbon (methane).

In particular, when the gas to be separated is a mixed gas of carbon dioxide and methane, the permeation rate of carbon dioxide at 30 ° C. and 5 MPa is preferably 10 GPU or more, more preferably 10 to 300 GPU. 15 to 300 GPU is particularly preferable.
1 GPU is 1 × 10 ⁻⁶ cm ³ (STP) / cm ² · sec · cmHg.

The gas separation membrane of the present invention is a gas separation selection which is the ratio of the carbon dioxide permeation flux to the methane permeation flux at 30 ° C. and 5 MPa when the gas to be separated is a mixed gas of carbon dioxide and methane. The property α is preferably 30 or more, more preferably 35 or more, particularly preferably 40 or more, and more preferably 50 or more.

It is considered that the selective gas permeation involves a dissolution / diffusion mechanism into the membrane. Taking advantage of such a viewpoint, a separation membrane containing a PEO composition has been studied (see Journal of Membrane Science, 1999, 160, 87-99). This is because carbon dioxide has a strong interaction with the polyethyleneoxy composition. Since the polyethyleneoxy membrane is a flexible rubber-like polymer membrane having a low glass transition temperature, the difference in diffusion coefficient due to the gas species is small, and the gas separation selectivity is mainly due to the effect of the difference in solubility. On the other hand, in a preferred embodiment of the present invention, the glass transition temperature of the compound having a siloxane bond contained in the resin layer containing the compound having a siloxane bond described above is high, and the film is heated while exhibiting the dissolution / diffusion action. From the viewpoint of durability, it can be greatly improved.

[Method for producing gas separation membrane]
The method for producing the gas separation membrane of the present invention is not particularly limited.
In the method for producing a gas separation membrane of the present invention, it is preferable to perform a specific treatment on the resin layer precursor containing a compound having a siloxane bond. The specific treatment to be applied to the resin layer precursor containing a compound having a siloxane bond is preferably an oxygen atom permeation treatment in which oxygen atoms permeate the resin layer precursor containing a compound having a siloxane bond. It is more preferable that
The method for producing a gas separation membrane of the present invention is preferably the following method for producing a gas separation membrane of the present invention.
The method for producing a gas separation membrane of the present invention includes an oxygen atom permeation treatment step in which oxygen atoms permeate a resin layer precursor containing a compound having a siloxane bond, and the oxygen atom permeation treatment step described above includes an oxygen flow rate of 10 cm ^3. (STP) / min or higher and a plasma treatment with an input power of 23 W or more.

A preferred configuration of the method for producing a gas separation membrane of the present invention and the method for producing a gas separation membrane of the present invention will be described with reference to the drawings.
As shown in FIG. 5, the method for producing a gas separation membrane of the present invention is a resin containing a compound having a siloxane bond with respect to a laminate of a support 4 and a resin layer precursor 2 containing a compound having a siloxane bond. It is preferable to include a step of performing a specific treatment (oxygen atom permeation treatment 5) from one surface side of the layer precursor 2.
The method for producing a gas separation membrane of the present invention includes a step of forming an additional resin layer on a surface obtained by performing a specific treatment (oxygen atom permeation treatment 5) on a resin layer precursor containing a compound having a siloxane bond. It may be included (not shown).

<Formation of resin layer precursor containing compound having siloxane bond>
The method for producing a gas separation membrane of the present invention preferably includes a step of forming a resin layer precursor containing a compound having a siloxane bond on the aforementioned support.
The method for forming the resin layer precursor containing the compound having a siloxane bond on the support is not particularly limited, but a resin layer precursor material containing a compound having a siloxane bond and a composition containing an organic solvent are used. It is preferable to apply. The coating method is not particularly limited, and a known method can be used. For example, a spin coating method, a dip coating method, or a bar coating method can be appropriately used.
The resin layer precursor material containing a compound having a siloxane bond and the composition containing an organic solvent are preferably curable compositions. Although there is no restriction | limiting in particular as a method of radiation irradiation to a curable composition when forming the resin layer containing the compound which has a siloxane bond, Electron beam, an ultraviolet-ray (UV), visible light, or infrared irradiation can be used. Depending on the material used, it can be appropriately selected.
The irradiation time is preferably 1 to 30 seconds.
The radiant energy (radiation intensity) is preferably 10 to 2000 mW / cm ² .
Integrated light intensity (integrated radiant energy amount) be greater than ^{0.05J / cm 2 (UV-A} ), preferably in view of enhancing the gel fraction of the gas separation membrane, 0.1 J ^/ cm 2 and (UV-A) More preferably, it is 0.1 to 60 J / cm ² (UV-A), particularly preferably 0.1 to 5 J / cm ² (UV-A).

Examples of the compound having a siloxane bond used for the material of the resin layer precursor including a compound having a siloxane bond include polydimethylsiloxane (hereinafter also referred to as PDMS), polydiphenylsiloxane (polydiphenylsiloxane), and polydi (trifluoropropyl) siloxane. (Polydi (trifluoropropyl) siloxane), polymethyl (3,3,3-trifluoropropyl) siloxane (Poly [methyl (3,3,3-trifluoropropyl) siloxane]), poly (1-trimethylsilyl-1-propyne) ( In the following, it preferably contains at least one selected from PTMSP, and polydimethylsiloxane or poly (1-trimethylsilyl-1-propylene). ) More preferably containing, it is particularly preferred that it include a polydimethylsiloxane.

<Treatment of resin layer precursor containing a compound having a siloxane bond>
In the method for producing a gas separation membrane of the present invention, a specific treatment (oxygen atom permeation treatment) for infiltrating oxygen atoms (preferably from one surface side) is performed on a resin layer precursor containing a compound having a siloxane bond. Preferably, the process includes a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms. A certain O / Si ratio (A) and an O / Si ratio (B) which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond described above satisfy the above formula 1. It is more preferable to perform the above-described specific processing.

Although there is no restriction | limiting in particular as a method of performing the above-mentioned specific process, For example, the method of performing plasma processing from the one surface side of the resin layer precursor containing the compound which has a siloxane bond can be mentioned.
The method for producing a gas separation membrane of the present invention includes an oxygen atom infiltration treatment step of infiltrating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
The oxygen atom permeation treatment process described above is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm ³ (STP) / min or more and an input power of 23 W or more.
For example, a method of performing the above-described plasma treatment for 5 to 30 seconds under the following conditions can be mentioned.
Plasma treatment conditions: oxygen flow rate 10 cm ³ (STP) / min or more, argon flow rate 100 cm ³ (STP) / min, input power (discharge output) 23 W or more.

The plasma treatment is preferably 5 seconds or longer under the above conditions, more preferably from the viewpoint of enhancing gas separation selectivity and increasing the scratch resistance and making it difficult to reduce gas separation selectivity. Particularly preferred, more preferably 20 seconds or more.
On the other hand, it is preferable that the above-mentioned plasma treatment be performed for 1000 seconds or less under the above conditions. When the above-mentioned specific treatment is a plasma treatment, a sufficient effect can be obtained by a short time treatment, and therefore, it can be applied to production by roll-to-roll. The aforementioned plasma treatment is more preferably 40 seconds or less under the above conditions, and particularly preferably 30 seconds or less.
Further, the cumulative energy amount by the plasma treatment is preferably 25 ~ 500000J / cm ^2, and more preferably 2500 ~ 100000J / cm ^2.

The plasma treatment applied to the present invention includes a mode in which a low-pressure plasma is used to generate a stable plasma, and an object to be processed is processed in a large vacuum chamber. Recently, an atmospheric pressure plasma processing apparatus capable of processing in an atmospheric pressure atmosphere has been developed. In this case, gas can be introduced into the process chamber and high-density plasma can be stably generated under an atmospheric pressure atmosphere. Examples of the system configuration of the atmospheric pressure plasma processing apparatus include a system composed of a gas mixing / control unit, a reactor, and a transfer conveyor (or XY table). There has also been proposed a method in which a plasma jet is blown out in a spot manner from a circular nozzle.
As plasma treatment conditions, the argon flow rate is preferably 5 to 500 cm ³ (STP) / min, more preferably 50 to 200 cm ³ (STP) / min, and 80 to 120 cm ³ (STP) / min. It is particularly preferred. In the method for producing a gas separation membrane of the present invention, the oxygen flow rate is 10 cm ³ (STP) / min or more, preferably 10 to 100 cm ³ (STP) / min, and 15 to 100 cm ³ (STP) / min. More preferably, it is particularly preferably 20 to 50 cm ³ (STP) / min. When the total pressure of the gas supplied to the gas separation membrane and the partial pressure of CO ₂ are not so high, for example, when the total pressure is 5 MPa and the partial pressure of CO ₂ is about 0.65 MPa, the oxygen flow rate is 45 cm ³ (STP) / min. It may be less.
As plasma treatment conditions, the degree of vacuum is preferably 0.6 to 100 Pa, more preferably 1 to 60 Pa, and particularly preferably 2 to 40 Pa.
In the method for producing a gas separation membrane of the present invention, as plasma treatment conditions, the input power (discharge output) is 23 W or more, preferably 23 to 1000 W, more preferably 40 to 1000 W, more preferably 110 to Particularly preferred is 500 W.
Corona treatment or the like can be used instead of plasma treatment.

<Method for preparing additional resin layer>
The method for preparing the additional resin layer other than the resin layer containing the compound having a siloxane bond is not particularly limited, and a specific resin may be used regardless of whether a known material is obtained commercially or formed by a known method. You may form by the method of mentioning later using.

The method for forming the additional resin layer other than the resin layer containing the compound having a siloxane bond is not particularly limited, but the material of the additional resin layer other than the resin layer containing the compound having the siloxane bond and the organic solvent are used. It is preferable to apply the composition containing the composition to a lower layer (for example, a resin layer containing a compound having a siloxane bond). A coating method is not particularly limited and a known method can be used. For example, a spin coating method can be used.
The conditions for forming the additional resin layer other than the resin layer containing the compound having a siloxane bond in the gas separation membrane of the present invention are not particularly limited, but the temperature is preferably −30 to 100 ° C., and −10 to 80 ° C. More preferred is 5 to 50 ° C.

In the present invention, a gas such as air or oxygen may coexist at the time of forming an additional resin layer other than the resin layer containing a compound having a siloxane bond as described above, but it is preferably in an inert gas atmosphere.

<Formation of protective layer>
The manufacturing method of the gas separation membrane of this invention may include the process of forming a protective layer on the surface which performed the surface treatment of the resin layer precursor containing the compound which has the above-mentioned siloxane bond.
The method for forming the protective layer on the surface of the resin layer precursor containing the compound having a siloxane bond described above is not particularly limited, but a composition containing the protective layer material and the organic solvent is not particularly limited. It is preferable to apply. As an organic solvent, the organic solvent used for formation of the resin layer containing the compound which has the above-mentioned siloxane bond can be mentioned. A coating method is not particularly limited and a known method can be used. For example, a spin coating method can be used.
Although there is no restriction | limiting in particular as a method of radiation irradiation to the curable composition when forming a protective layer, Although an electron beam, an ultraviolet-ray (UV), visible light, or infrared irradiation can be used, according to the material to be used suitably. You can choose.
The irradiation time is preferably 1 to 30 seconds.
The radiant energy is preferably 10 to 2000 mW / cm ² .

<Separation method of gas mixture>
By using the gas separation membrane of the present invention, the gas mixture can be separated.
In the method for separating a gas mixture using the gas separation membrane of the present invention, the components of the raw material gas mixture are affected by the raw material production area, application, or use environment, and are not particularly defined. The main components are preferably carbon dioxide and methane or carbon dioxide and nitrogen or carbon dioxide and hydrogen.
That is, the proportion of carbon dioxide and methane or carbon dioxide and hydrogen in the gas mixture is preferably 5 to 50%, more preferably 10 to 40% as the proportion of carbon dioxide. When the gas mixture is in the presence of an acidic gas such as carbon dioxide or hydrogen sulfide, the separation method of the gas mixture using the gas separation membrane of the present invention exhibits particularly excellent performance, preferably carbonization such as carbon dioxide and methane. Excellent performance in separation of hydrogen, carbon dioxide and nitrogen, and carbon dioxide and hydrogen.
The method for separating the gas mixture is preferably a method including selectively permeating carbon dioxide from a mixed gas containing carbon dioxide and methane. The pressure at the time of gas separation is preferably from 3 MPa to 10 MPa, more preferably from 4 MPa to 7 MPa, and particularly preferably from 5 MPa to 7 MPa. The gas separation temperature is preferably −30 to 90 ° C., more preferably 15 to 70 ° C.

[Gas separation membrane module, gas separation device]
The gas separation membrane module of the present invention has the gas separation membrane of the present invention.
The gas separation membrane of the present invention is preferably a thin layer composite membrane combined with a porous support, and more preferably a gas separation membrane module using this. Moreover, it can be set as the gas separation apparatus which has a means for carrying out the separation separation collection | recovery or separation refinement | purification using the gas separation membrane of this invention, a thin layer composite membrane, or a gas separation membrane module. The gas separation membrane of the present invention can be suitably used in a modular form. Examples of modules include spiral type, hollow fiber type, pleated type, tubular type, plate & frame type and the like. The gas separation membrane of the present invention may be applied to a gas separation and recovery device as a membrane / absorption hybrid method used in combination with an absorbing solution as described in, for example, JP-A-2007-297605.

{Second aspect}
Next, a second mode that satisfies condition 2 will be described.

[Gas separation membrane]
The gas separation membrane of the present invention comprises a porous support A,
A gas separation membrane having a resin layer containing a compound having a siloxane bond located on the porous support A,
The compound having a siloxane bond has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3),
A resin layer containing a compound having a siloxane bond includes a region GLi present in the porous support B and a region GLe present on the porous support B;
The thickness of GLe is 50 to 1000 nm,
The thickness of GLi is 20 nm or more and 10 to 350% of the thickness of GLe;
The difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is 30 to 90%. Gas separation membrane;

In General Formula (2) and General Formula (3), R ¹¹ represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3).
With such a configuration, the gas separation membrane of the present invention has high bend resistance and at least one of gas permeability under high pressure and gas separation selectivity.
The difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is 30 to 90%. And a resin layer containing a compound in which oxygen atoms have a siloxane bond (the resin layer containing a compound having a siloxane bond functions as a layer having a high gas separation selectivity and a so-called separation selectivity) to the inside in the thickness direction. It will penetrate. In the corona treatment or plasma treatment aiming only at improving the adhesion by modifying the surface, oxygen does not enter sufficiently to have a gas separation selectivity from the surface of the resin layer containing a compound having a siloxane bond to a depth of 20 nm. The higher the value of the difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm, the higher the siloxane. The surface of the resin layer containing the compound having a bond is modified so that many oxygen atoms are taken in. In the present invention, it is possible to obtain a gas separation membrane having at least one of gas permeability and gas separation selectivity under high pressure. Without being bound by any theory, it is considered that separation selectivity is expressed by incorporating oxygen atoms not only into the surface of the resin layer containing a compound having a siloxane bond but also into the thickness direction.
The layer having separation selectivity is a film having a thickness of 0.1 to 30 μm, and the obtained film is oxidized at a temperature of 40 ° C. with a total pressure of 0.5 MPa on the gas supply side. When the pure gas of carbon (CO ₂ ) and methane (CH ₄ ) is supplied, the ratio of the carbon dioxide permeability coefficient (PCO ₂ ) to the methane permeability coefficient (PCH ₄ ) (PCO ₂ / PCH ₄ ) is 1 Means a layer of 5 or more.
Conventionally, a layer having a polyimide compound has often been used as a layer having gas separation membrane separation selectivity, and a polyimide compound is obtained by having a resin layer containing a compound having a siloxane bond subjected to oxygen atom permeation treatment. The structure of the gas separation membrane of the present invention that does not have a layer and has at least one of gas permeability and gas separation selectivity under high pressure has not been known.
Here, the gas permeability and gas separation selectivity of the gas separation membrane are generally in a trade-off relationship. In other words, the gas separation membrane tends to decrease the gas separation selectivity when the gas permeability increases, and the gas separation selectivity tends to increase when the gas permeability decreases. Therefore, it has been difficult for conventional gas separation membranes to increase both gas permeability and gas separation selectivity. In contrast, the gas separation membrane of the present invention can increase both gas permeability and gas separation selectivity.
This is because the gas separation membrane of the present invention has the resin layer 3 containing a compound having a siloxane bond having a structure in which oxygen atoms are introduced with gradation from the surface as shown in FIG. 6B. . Sites where oxygen atoms are introduced form pores by siloxane bonds. In addition, the introduction of oxygen reduces the thermal motion of the polymer. For this reason, the hole which can permeate | transmit many gas selectively has produced | generated. For this reason, unlike a resin layer containing a compound having a siloxane bond before the surface treatment (polydimethylsiloxane membrane 11 not subjected to the oxygen atom permeation treatment step as shown in FIG. 6A), high gas separation is achieved. Selectivity can be obtained.
In addition, polydimethylsilane in which oxygen atoms are uniformly introduced in the film thickness direction as shown in FIG. 6C without using gradation of oxygen atom introduction in the film thickness direction using a CVD (Chemical Vapor Deposition) method or the like. It is possible to produce a siloxane film. When such a membrane is compared with the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention, oxygen atoms are present in the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention. The densely introduced portion is thinner than the polydimethylsiloxane film 12 into which oxygen atoms are uniformly introduced in the film thickness direction. The polydimethylsiloxane membrane in which oxygen atoms are uniformly introduced in the film thickness direction is equal to the thickness of the portion where the oxygen atoms are densely introduced in the resin layer 3 containing a compound having a siloxane bond in the gas separation membrane of the present invention. It is difficult to make it thinner. Therefore, the present invention can achieve extremely high gas permeability and gas separation selectivity.
On the other hand, the gas separation membrane of the present invention can be designed to greatly increase gas permeability and lower gas separation selectivity. In addition, the gas separation membrane of the present invention can be designed to have low gas permeability and greatly increase gas separation selectivity. Even in these cases, if the gas separation membrane of the present invention has the same gas permeability as that of the conventional gas separation membrane, the gas separation membrane of the present invention is more gas selective than the conventional gas separation membrane. In addition, if the gas separation membrane of the present invention has the same gas separation selectivity as the conventional gas separation membrane, the gas separation membrane of the present invention has higher gas permeability than the conventional gas separation membrane. .
The gas separation membrane of the present invention includes a region GLi present in the porous support B and a region GLe present on the porous support B, the thickness of GLe is 50 to 1000 nm, and the thickness of GLi is When it is 20 nm or more and is 10 to 350% of the thickness of GLe, the resin layer containing a part of the porous support and the compound having a siloxane bond is integrated, and the bending resistance is also improved. .
Hereinafter, preferred embodiments of the gas separation membrane of the present invention will be described.

A preferred configuration of the gas separation membrane of the present invention will be described with reference to the drawings. An example of the gas separation membrane 10 of the present invention shown in FIG. 1 is a thin-layer composite membrane, which has a porous support A (reference numeral 4) and a resin layer 3 containing a compound having a siloxane bond. It is. As shown in FIG. 7, in the gas separation membrane of the present invention, the resin layer containing a compound having a siloxane bond has a region GLi present in the porous support B and a region GLe present on the porous support B. Including.
Another example of the gas separation membrane 10 of the present invention shown in FIG. 2 is a resin containing a compound having a siloxane bond in addition to the porous support A (reference numeral 4) and the resin layer 3 containing a compound having a siloxane bond. The layer 3 further includes a layer (an additional resin layer described later) 1 containing a polyimide compound on the opposite side of the porous support A (reference numeral 4).
The gas separation membrane of the present invention may have only one resin layer containing a compound having a siloxane bond, or may have two or more layers. The gas separation membrane of the present invention preferably has 1 to 5 resin layers containing a compound having a siloxane bond, more preferably 1 to 3 layers, and particularly preferably 1 to 2 layers from the viewpoint of production cost. It is particularly preferable to have only one layer. Another example of the gas separation membrane 10 of the present invention shown in FIG. 3 has two resin layers 3 containing a compound having a siloxane bond.

Further, in FIG. 4, when d is 10 nm, “resin containing a compound having a siloxane bond” at a depth of 10 nm from the surface of the resin layer 3 containing a compound having a siloxane bond (in the direction of the porous support A). The surface parallel to the “surface of the layer” 6 is a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond (in the direction of the porous support A) represented by reference numeral 7. The surface of the resin layer to be included ".

<Porous support A>
The gas separation membrane of the present invention has a porous support A and a resin layer containing a compound having a siloxane bond located on the porous support A. The porous support A is preferably a thin and porous material in order to ensure sufficient gas permeability.

In the gas separation membrane of the present invention, the resin layer containing a compound having a siloxane bond includes a region GLi present in the porous support B and a region GLe present on the porous support B. That is, it is a thin-layer composite film in which the resin layer 3 containing a compound having a siloxane bond is formed and arranged in (inside) and on (on the surface) the porous support. By forming the resin layer 3 containing a compound having a siloxane bond on the surface of the porous support, a part of the porous support is soaked and filled with the compound having a siloxane bond. As a result, the porous support A that is not filled with a resin layer containing a compound having a siloxane bond, and the aforementioned GLi in which a part of the resin layer containing a compound having a siloxane bond is present in the porous support B and The above-mentioned GLe in which the rest of the resin layer containing a compound having a siloxane bond is present on the porous support B is formed, and has the advantage of having both high gas separation selectivity, high gas permeability, and bending resistance. A gas separation membrane having

When the gas separation membrane of the present invention is a thin-layer composite membrane, the thin-layer composite membrane is obtained by applying a coating liquid (dope) that forms the resin layer 3 containing the compound having a siloxane bond on the surface of the porous support. It is preferably formed by coating (in this specification, coating means to include an aspect of being attached to the surface by dipping). Specifically, the porous support A preferably has a porous layer on the resin layer 3 side containing a compound having a siloxane bond, and is arranged on the resin layer 3 side containing a compound having a siloxane bond. More preferably, it is a laminated body of a porous layer and a nonwoven fabric (Non-Woven).

The porous layer preferably applied to the porous support A is not particularly limited as long as it has the purpose of meeting mechanical strength and high gas permeability. However, it is preferably a porous film of an organic polymer, and the thickness thereof is 1 to 3000 μm, preferably 5 to 500 μm, more preferably 5 to 150 μm. The porous structure of this porous layer usually has an average pore diameter of 10 μm or less, preferably 0.5 μm or less, more preferably 0.2 μm or less, and a porosity of preferably 20 to 90%. Preferably, it is 30 to 80%. The molecular weight cutoff of the porous layer is preferably 100,000 or less, and the gas permeability is 3 × 10 ⁻⁵ cm ³ (STP; STP is an abbreviation for Standard Temperature and Pressure). ) / Cm ² · cm · sec · cmHg (30 GPU; GPU is an abbreviation for Gas Permeation Unit). Examples of the material for the porous layer include conventionally known polymers such as polyolefin resins such as polyethylene and polypropylene, fluorine-containing resins such as polytetrafluoroethylene, polyvinyl fluoride, and polyvinylidene fluoride, polystyrene, cellulose acetate, and polyurethane. And various resins such as polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, and polyaramid. The shape of the porous layer may be any shape such as a flat plate shape, a spiral shape, a tubular shape, and a hollow fiber shape.

<Resin layer containing a compound having a siloxane bond>
The gas separation membrane of the present invention has a resin layer containing a compound having a siloxane bond.
In the gas separation membrane of the present invention, the resin layer containing a compound having a siloxane bond includes a region GLi present in the porous support B and a region GLe present on the porous support B,
The thickness of GLe is 50 to 1000 nm,
The thickness of GLi is 20 nm or more and 10 to 350% of the thickness of GLe;
The difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is 30 to 90%. .

(Characteristic)
In the gas separation membrane of the present invention, the thickness of GLe is 50 to 1000 nm, preferably 200 to 900 nm, and more preferably 300 to 800 nm. When the thickness of GLe is equal to or greater than the lower limit value, the stress relaxation action against bending is improved, and it is formed above the inside of the resin layer containing the compound having a siloxane bond (region opposite to the porous support A). Moreover, the bending resistance with respect to the area | region with a high silica component (the content rate of the repeating unit represented by General formula (3) is high) becomes favorable. When the thickness of GLe is equal to or less than the upper limit value, the gas separation performance is improved without inhibiting the gas permeability.

In the gas separation membrane of the present invention, the thickness of GLi is 20 nm or more, and the absolute value of the thickness of GLi can be set in an arbitrary range unless it is contrary to the spirit of the present invention.
In the gas separation membrane of the present invention, the thickness of GLi (GLi thickness ratio [vs. GLe%]) is 10 to 350%, preferably 20 to 90%, preferably 20 to 60% of the thickness of GLe. More preferably, it is 21.2 to 60%. When the ratio of the thickness of GLi [vs. GLe%] is equal to or higher than the lower limit, the adhesion with the porous support A is improved, so that the inside of the resin layer containing the compound having a siloxane bond (porous The bending resistance with respect to the region having a high silica component (the content of the repeating unit represented by the general formula (3) is high) formed in the region opposite to the support A is improved. When the ratio of the thickness of GLi [vs. GLe%] is less than or equal to the upper limit, that is, when the penetration rate of GLi becomes small to some extent, the gas separation performance is improved without hindering gas permeability.

The gas separation membrane of the present invention comprises the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm. The difference is 30 to 90%, and 40 to 90% is preferable from the viewpoint of bending resistance. When the difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is not less than the lower limit. The desired selectivity with respect to gas permeability is obtained. When the difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is not more than the upper limit value. The resin layer containing a compound having a siloxane bond existing between the GLe surface and the GLi surface against bending can be sufficiently relaxed, and the bending resistance is improved.
In the gas separation membrane, the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm is preferably 30 to 95%, more preferably 40 to 95%, and more preferably 45 to 90%. It is particularly preferred that
In the gas separation membrane, the content of the repeating unit represented by the general formula (3) in the GLi surface layer of 20 nm is preferably 1 to 10%, more preferably 3 to 8%, and more preferably 4 to 6%. It is particularly preferred that

In the gas separation membrane of the present invention, the thickness of the resin layer containing a compound having a siloxane bond (synonymous with the thickness) is not particularly limited, but the thickness of the resin layer containing a compound having a siloxane bond is 0. The thickness is preferably 1 μm or more from the viewpoint of film formation ease, more preferably 0.1 to 5 μm, particularly preferably 0.1 to 4 μm, and more preferably 0.3 to 3 μm. Particularly preferred.
In the gas separation membrane having a resin layer containing a compound having a siloxane bond on the porous support A, it is difficult to evaluate the thickness of each layer by SEM including the case where there are other plural layers. Therefore, GLe and GLi in the present invention are confirmed from the analysis in the depth direction of TOF-SIMS. In the profile in the depth direction, the maximum intensity of the peak intensity derived from silicone is defined as GLe where the peak intensity continuously present from the peak position is 90% or more, and the range is 20% or more and less than 90% Is defined as GLi, and the range of less than 20% is designated as porous support A.
The film thickness of the resin layer containing the compound having a siloxane bond can be controlled by adjusting the coating amount of the curable composition.

(Surface of resin layer containing compound having siloxane bond)
O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms; The O / Si ratio (B), which is the ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond, is calculated using ESCA (Electron Spectroscopy FOR Chemical Analysis). Similarly, the carbon / silicon ratio, which is the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond, is also calculated.
A porous support formed with a resin layer containing a compound having a siloxane bond was obtained from Physical Electronics, Inc. Included in Quantera SXM manufactured by the company, X-ray source: Al—Kα ray (1490 eV, 25 W, diameter of 100 μm), measurement area: 300 μm × 300 μm, Pass Energy 55 eV, Step 0.05 eV, including a compound having a siloxane bond An O / Si ratio (B), which is a ratio of the number of oxygen atoms on the surface of the resin layer to the number of silicon atoms, is calculated.
Subsequently, an O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms (A ) Is performed with C ₆₀ ions.
Specifically, Physical Electronics, Inc. At Company Ltd. QuanteraSXM comes _{C 60} ion gun, ion beam intensity _C ⁶⁰ +: 10 keV, and 10 nA, to 10nm etching an area of 2 mm × 2 mm. An ESCA apparatus is used for this film to calculate an O / Si ratio (A) that is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond. The depth of the resin layer containing the compound having a siloxane bond from the surface of the resin layer containing the compound having a siloxane bond is calculated from the etching rate of 10 nm / min of the resin layer material containing the compound having a siloxane bond. As this value, an optimal value is appropriately used depending on the material.

In the present specification, the surface of the resin layer containing the compound having a siloxane bond described above was measured for the O / Si ratio from the surface of the gas separation membrane (preferably the surface opposite to the porous support A). In some cases, the O / Si ratio is maximum, and the number of silicon atoms is 3% (atomic%) or more.
When there is no other layer on the surface of the resin layer containing a compound having a siloxane bond, oxygen atoms of the resin layer containing the compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond When the O / Si ratio is measured from the surface of the gas separation membrane in the same manner as the method for obtaining the O / Si ratio (A), which is the ratio of the number to the number of silicon atoms, the O / Si ratio is maximum. And a plane containing 3% (atomic%) or more of silicon atoms is specified.
As a result, in the above-described method, it has a siloxane bond in a state where a resin layer containing a compound having a siloxane bond is formed on the porous support A (a state without any other layer (for example, a layer containing polyimide)). The surface of the resin layer containing the compound indicates that “the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. It is confirmed that the surface

When the surface of the resin layer containing a compound having a siloxane bond has another layer (for example, a layer containing polyimide), the surface of the resin layer containing a compound having a siloxane bond (that is, the O / Si ratio is set to the above-mentioned gas separation membrane). The depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond, the surface having the maximum O / Si ratio when measured from the surface and containing 3% (atomic%) or more of silicon atoms) The resin layer containing a compound having a siloxane bond in is obtained by a method similar to the method for obtaining the O / Si ratio (A), which is the ratio of the number of oxygen atoms to the number of silicon atoms.
As a result, in the above-described method, it has a siloxane bond in a state where a resin layer containing a compound having a siloxane bond is formed on the porous support A (a state without any other layer (for example, a layer containing polyimide)). The surface of the resin layer containing the compound indicates that “the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. The surface to be Specifically, “a compound having a siloxane bond in a state in which a resin layer containing a compound having a siloxane bond is formed on the porous support A (without any other layer (for example, a layer containing polyimide)). From the “surface of the resin layer containing”, “the O / Si ratio is the maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. Means "face".

(material)
In the gas separation membrane of the present invention, the compound having a siloxane bond has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3).

In general formula (1), each R independently represents a hydrogen atom, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group, a fluorinated alkyl group, a vinyl group, an alkoxy group or a carboxyl group, and n is Represents an integer of 2 or more.
When such a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond, and the resin layer containing the compound having a siloxane bond is formed, high gas permeability and gas under high pressure Separation selectivity can be expressed.
Further, when a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond, and the resin layer containing the compound having a siloxane bond described above is formed, it is not bound by any theory. Not only the surface of the resin layer containing a compound containing a siloxane bond in the atoms but also the inside of the resin in the thickness direction to form a composition of SiOx, thereby exhibiting high gas permeability and gas separation selectivity under high pressure. it is conceivable that. In particular, even when polydimethylsiloxane, which is known for its high gas permeability, is used, it exhibits high gas permeability and separation selectivity under high pressure by using a resin layer containing the above-mentioned compound having a siloxane bond. can do. Not only the surface of the resin layer containing the compound having a siloxane bond but also the surface of the resin layer containing the compound having a siloxane bond and the thickness of the resin layer containing the compound having a siloxane bond. Inside the direction, the compound having a siloxane bond has at least a repeating unit represented by the general formula (2) or a repeating unit represented by the general formula (3).

R in the general formula (1) is preferably independently an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group or a carboxyl group, and an alkyl group having 1 or more carbon atoms, an amino group or an epoxy group. Alternatively, a carboxyl group is more preferable, and an alkyl group having 1 or more carbon atoms, an epoxy group, or a carboxyl group is particularly preferable.
The alkyl group having 1 or more carbon atoms represented by R in the general formula (1) is preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, or a propyl group, and particularly preferably a methyl group. The alkyl group having 1 or more carbon atoms represented by R may be linear, branched or cyclic.
As the aryl group represented by R in the general formula (1), an aryl group having 6 to 20 carbon atoms is preferable, and a phenyl group is particularly preferable.
The fluorinated alkyl group represented by R in the general formula (1) is preferably a fluorinated alkyl group having 1 to 10 carbon atoms, more preferably a fluorinated alkyl group having 1 to 3 carbon atoms, and particularly preferably a trifluoromethyl group. . The fluorinated alkyl group represented by R may be linear, branched or cyclic.
The alkoxy group represented by R in the general formula (1) is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably a methoxy group, an ethoxy group, or a propyloxy group, and particularly preferably a methoxy group. The alkoxy group having 1 or more carbon atoms represented by R may be linear, branched or cyclic.
In the general formula (1), n represents an integer of 2 or more, preferably 40 to 800, more preferably 50 to 700, and particularly preferably 60 to 500.

In the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 20 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the above-described compound having the siloxane bond included in the resin layer containing the compound having the siloxane bond at a depth of 20 nm from the surface of the resin layer containing the compound having the siloxane bond described above. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 3.0 to 500 mol%. It is preferably 3.5 to 450 mol%, more preferably 4.0 to 400 mol%.

The polyimide compound is preferably a polyimide having a reactive group.

Specific examples of preferred polyimides having a reactive group that can be used in the present invention are listed below, but the present invention is not limited thereto. In the following formulae, “100”, “x”, and “y” represent copolymerization ratios (molar ratios). Examples of “x”, “y” and weight average molecular weight are shown in Table 2 below. In the polyimide compound that can be used in the present invention, y is preferably not 0.

Further, when the resin of the additional resin layer is polyimide, more specifically, the product name P84 and the product from Matrimid 5218 and HP Polymers GmbH sold under the Matrimid (registered trademark) trademark of Huntsman Advanced Materials, respectively. P84 or P84HT sold under the name P84HT is also preferable.

It is preferable from the viewpoint of improving adhesiveness and improving bending resistance that no other additional resin layer enters between the porous support A and the resin layer containing a compound having a siloxane bond. Examples of other additional resin layers include adjustment of hydrophilicity / hydrophobicity such as PVA.

[Method for producing gas separation membrane]
The method for producing the gas separation membrane of the present invention is not particularly limited.
In the method for producing a gas separation membrane of the present invention, it is preferable to perform a specific treatment on the resin layer precursor containing a compound having a siloxane bond. The specific treatment to be applied to the resin layer precursor containing a compound having a siloxane bond is preferably an oxygen atom permeation treatment in which oxygen atoms permeate the resin layer precursor containing a compound having a siloxane bond. It is more preferable that
In manufacturing the gas separation membrane of the present invention, the thickness of GLe and GLi can be controlled by adjusting the following parameters according to the coating method. Viscosity of composition (coating liquid), solid content concentration, time to cure after coating, etc. For example, when applying by spin coating, the thicknesses of GLe and GLi can also be controlled by adjusting the amount of coating solution and the spin coating rotational speed.

A preferred configuration of the method for producing a gas separation membrane of the present invention will be described with reference to the drawings.
As shown in FIG. 5, the method for producing a gas separation membrane of the present invention comprises a porous support A (reference numeral 4) and a laminate of a resin layer precursor 2 containing a compound having a siloxane bond. It is preferable to include a step of performing a specific treatment (oxygen atom permeation treatment 5) from the one surface side of the resin layer precursor 2 containing a compound having a hydrogen atom.
The method for producing a gas separation membrane of the present invention includes a step of forming an additional resin layer on a surface obtained by performing a specific treatment (oxygen atom permeation treatment 5) on a resin layer precursor containing a compound having a siloxane bond. It may be included (not shown).

<Formation of resin layer precursor containing compound having siloxane bond>
The method for producing a gas separation membrane of the present invention preferably includes a step of forming a resin layer precursor containing a compound having a siloxane bond on the aforementioned support.
The method for forming the resin layer precursor containing the compound having a siloxane bond on the support is not particularly limited, but a resin layer precursor material containing a compound having a siloxane bond and a composition containing an organic solvent are used. It is preferable to apply.
The solid content concentration (viscosity) of the composition is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, and particularly preferably 3 to 30% by mass. The higher the solid concentration of the composition, the easier it is to make GLi thinner.
The dropping amount of the composition is preferably 0.001 to 1 ml / cm ² , more preferably 0.002 to 0.5 ml / cm ² , and 0.005 to 0.3 ml / cm ² . It is particularly preferred. The smaller the amount of composition dropped, the easier it is to make GLi thinner.
There is no restriction | limiting in particular as a coating method of a composition, Although a well-known method can be used, For example, a spin coat method, a dip coat method, and a bar coat method can be used suitably. The spin coating rotation speed is preferably 100 to 10,000 rpm (round per minute), more preferably 500 to 9000 rpm, and particularly preferably 700 to 8000 rpm. The larger the spin coating speed, the easier it is to make GLi thinner.
The resin layer precursor material containing a compound having a siloxane bond and the composition containing an organic solvent are preferably curable compositions. The time from application of the composition to curing is preferably from 0.01 to 60 minutes, more preferably from 0.02 to 50 minutes, and particularly preferably from 0.03 to 30 minutes. The shorter the time until curing after application of the composition, the easier it is to make GLi thinner.
Although there is no restriction | limiting in particular as a method of radiation irradiation to a curable composition when forming the resin layer containing the compound which has a siloxane bond, Electron beam, an ultraviolet-ray (UV), visible light, or infrared irradiation can be used. Depending on the material used, it can be appropriately selected.
The irradiation time is preferably 1 to 30 seconds.
The radiant energy (radiation intensity) is preferably 10 to 2000 mW / cm ² .

<Treatment of resin layer precursor containing a compound having a siloxane bond>
In the method for producing a gas separation membrane of the present invention, a specific treatment (oxygen atom permeation treatment) for infiltrating oxygen atoms (preferably from one surface side) is performed on a resin layer precursor containing a compound having a siloxane bond. It is preferable to include a step, and the difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm It is more preferable to perform the above-described specific treatment until the amount reaches 30 to 90%.

Although there is no restriction | limiting in particular as a method of performing the above-mentioned specific process, For example, the method of performing plasma processing from the one surface side of the resin layer precursor containing the compound which has a siloxane bond can be mentioned.
The method for producing a gas separation membrane includes an oxygen atom infiltration treatment step of infiltrating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
It is preferable that the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm ³ (STP) / min or more and an input power of 23 W or more.
For example, a method of performing the above-described plasma treatment for 5 to 30 seconds under the following conditions can be mentioned.
Plasma treatment conditions: oxygen flow rate 10 cm ³ (STP) / min or more, argon flow rate 100 cm ³ (STP) / min, input power (discharge output) 23 W or more.

The plasma treatment applied to the present invention includes a mode in which a low-pressure plasma is used to generate a stable plasma, and an object to be processed is processed in a large vacuum chamber. Recently, an atmospheric pressure plasma processing apparatus capable of processing in an atmospheric pressure atmosphere has been developed. In this case, gas can be introduced into the process chamber and high-density plasma can be stably generated under an atmospheric pressure atmosphere. Examples of the system configuration of the atmospheric pressure plasma processing apparatus include a system composed of a gas mixing / control unit, a reactor, and a transfer conveyor (or XY table). There has also been proposed a method in which a plasma jet is blown out in a spot manner from a circular nozzle.
As plasma treatment conditions, the argon flow rate is preferably 5 to 500 cm ³ (STP) / min, more preferably 50 to 200 cm ³ (STP) / min, and 80 to 120 cm ³ (STP) / min. It is particularly preferred. In the method for producing a gas separation membrane of the present invention, the oxygen flow rate is 10 cm ³ (STP) / min or more, preferably 10 to 100 cm ³ (STP) / min, and 15 to 100 cm ³ (STP) / min. More preferably, it is particularly preferably 20 to 50 cm ³ (STP) / min.
As plasma treatment conditions, the degree of vacuum is preferably 0.6 to 100 Pa, more preferably 1 to 60 Pa, and particularly preferably 2 to 40 Pa.
In the method for producing a gas separation membrane of the present invention, as plasma treatment conditions, the input power (discharge output) is 23 W or more, preferably 23 to 1000 W, more preferably 40 to 1000 W, more preferably 110 to Particularly preferred is 500 W.
Corona treatment or the like can be used instead of plasma treatment.

{Third aspect}
Next, a third mode that satisfies condition 3 will be described.

[Gas separation membrane]
The gas separation membrane of the present invention is a gas separation membrane having a resin layer containing a compound having a siloxane bond,
The minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is 1 to 40%.
With such a configuration, the gas separation membrane of the present invention has high gas permeability at high pressure and gas separation selectivity, and is excellent in pressure resistance.
When the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is equal to or lower than the upper limit value, the gas permeation performance and the pressure resistance are It becomes good. On the other hand, when the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is equal to or higher than the lower limit value, the pressure resistance does not change much. However, gas permeation performance is improved.

The layer having separation selectivity is a film having a thickness of 0.1 to 30 μm, and the obtained film is oxidized at a temperature of 40 ° C. with a total pressure of 0.5 MPa on the gas supply side. When the pure gas of carbon (CO ₂ ) and methane (CH ₄ ) is supplied, the ratio of the carbon dioxide permeability coefficient (PCO ₂ ) to the methane permeability coefficient (PCH ₄ ) (PCO ₂ / PCH ₄ ) is 1 Means a layer of 5 or more.
Conventionally, a layer having a polyimide compound has often been used as a layer having gas separation membrane separation selectivity, and a polyimide compound is obtained by having a resin layer containing a compound having a siloxane bond subjected to oxygen atom permeation treatment. The structure of the gas separation membrane of the present invention that does not have a layer and has at least one of gas permeability and gas separation selectivity under high pressure has not been known.
Here, the gas permeability and gas separation selectivity of the gas separation membrane are generally in a trade-off relationship. In other words, the gas separation membrane tends to decrease the gas separation selectivity when the gas permeability increases, and the gas separation selectivity tends to increase when the gas permeability decreases. Therefore, it has been difficult for conventional gas separation membranes to increase both gas permeability and gas separation selectivity. On the other hand, the gas separation membrane of the present invention can increase both gas permeability and gas separation selectivity and is excellent in pressure resistance.
In the gas separation membrane of the present invention, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is 1 to 40%. FIG. 6B is a schematic view of a resin layer containing a compound having a siloxane bond in an example of the gas separation membrane of the present invention. For example, when the gas separation membrane has the resin layer 3 containing a compound having a siloxane bond having a structure in which oxygen atoms are introduced with gradation from the surface as shown in FIG. 6B, the compound containing the siloxane bond is included. The minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer is easily set to 1 to 40%. Sites where oxygen atoms are introduced form pores by siloxane bonds. In addition, the introduction of oxygen reduces the thermal motion of the polymer. Therefore, the gas separation membrane of the present invention in which the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is 1 to 40% Has produced pores that can selectively permeate many gases. On the other hand, the polydimethylsiloxane film 11 that has not been subjected to the oxygen atom permeation treatment step as shown in FIG. ^{6A is} a peak of Si ²⁺ and Si ³⁺ in ESCA depth analysis of a resin layer containing a compound having a siloxane bond. The minimum value Si _{0 of the} ratio to the total Si peak is over 40%. For this reason, unlike the resin layer (polydimethylsiloxane film 11 not subjected to the oxygen atom permeation treatment step as shown in FIG. 6A) containing a compound having a siloxane bond before the surface treatment, High gas separation selectivity can be obtained by the configuration of the gas separation membrane.
Furthermore, in the gas separation membrane of the present invention, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is 40% or less. In addition, the pressure resistance is excellent. The mechanism that the pressure resistance is excellent when the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is 40% or less is as follows. Although not bound by theory, the present inventors speculate that it is as follows.
When considered from a comparison with a crystalline glass film made of only Si ⁴⁺ , the density of the film decreases as the ratio of Si ²⁺ and Si ³⁺ increases. Therefore, also in the gas separation membrane of the present invention, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak is 40% or less, so that the membrane has sufficient pressure resistance. It is thought that it is obtained.
Further, a silica film in which oxygen atoms are uniformly introduced in the film thickness direction as shown in FIG. 6C without using gradation of oxygen atom introduction in the film thickness direction using a CVD (Chemical Vapor Deposition) method or the like. Is possible. When such a membrane is compared with the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention, silica in which oxygen atoms are uniformly introduced in the film thickness direction as shown in FIG. In the film, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is less than 1%. It is likely and difficult to control.
Further, in the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention, the site where oxygen atoms are introduced densely is compared with the silica membrane 12 where oxygen atoms are introduced uniformly in the film thickness direction. And thin. The silica membrane into which oxygen atoms are uniformly introduced in the film thickness direction is as thin as the thickness of the portion where the oxygen atoms are densely introduced in the resin layer 3 containing a compound having a siloxane bond in the gas separation membrane of the present invention. It is difficult to do.
Therefore, the gas separation membrane of the present invention can achieve both extremely high gas permeability and pressure resistance than the silica membrane into which oxygen atoms are uniformly introduced in the film thickness direction.
It should be noted that the gas separation membrane of the present invention can be designed to greatly increase gas permeability and lower gas separation selectivity. In addition, the gas separation membrane of the present invention can be designed to have low gas permeability and greatly increase gas separation selectivity. Even in these cases, if the gas separation membrane of the present invention has the same gas permeability as that of the conventional gas separation membrane, the gas separation membrane of the present invention is more gas selective than the conventional gas separation membrane. In addition, if the gas separation membrane of the present invention has the same gas separation selectivity as the conventional gas separation membrane, the gas separation membrane of the present invention has higher gas permeability than the conventional gas separation membrane. .
Hereinafter, preferred embodiments of the gas separation membrane of the present invention will be described.

In FIG. 4, the surface of the resin layer 3 containing a compound having a siloxane bond is represented by reference numeral 6.
Further, in FIG. 4, when d is 10 nm, “the surface of the resin layer containing a compound having a siloxane bond” at a depth of 10 nm from the surface of the resin layer 3 containing a compound having a siloxane bond (toward the support). "A surface parallel to 6 is represented by reference numeral 7" The surface of the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond (toward the support) " It is.

<Resin layer containing a compound having a siloxane bond>
The gas separation membrane of the present invention has a resin layer containing a compound having a siloxane bond.
In the gas separation membrane of the present invention, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is 1 to 40%. is there. Note that the total Si peak is the total of Si ²⁺ , Si ³⁺ and Si ⁴⁺ peaks (also referred to as all Si) in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond.
In the gas separation membrane of the present invention, the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond is 3 to 35%. Is preferable, and 4 to 30% is more preferable.
When the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is equal to or lower than the upper limit value, the gas permeation performance and the pressure resistance are It becomes good. On the other hand, when the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is equal to or higher than the lower limit value, the pressure resistance does not change much. However, gas permeation performance is improved.
As a method for controlling the ratio of the Si ²⁺ peak and the Si ³⁺ peak to the total Si peak, for example, when surface modification is performed by plasma treatment, plasma input power (W number), plasma treatment time (irradiation time), introduced O it can be controlled by adjusting the ₂ gas flow rate.

The gas separation membrane of the present invention has a depth of 10 nm from the position having the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond. preferably the ratio _{Si 10} with respect to the total Si peak ^{Si 2+} and ^{Si 3+,} the difference between the minimum value Si ₀ percentage relative to the peak of the total Si peak of ^{Si 2+} and ^{Si 3+} .DELTA.1 is 50-90% at a 55 to 85% is more preferable, and 60 to 80% is particularly preferable.
The gas separation membrane of the present invention has a depth of 20 nm from the position having the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond. preferably the ratio _{Si 20} with respect to the total Si peak ^{Si 2+} and ^{Si 3+,} the difference between the minimum value Si ₀ percentage relative to the peak of the total Si peak of ^{Si 2+} and ^{Si 3+} Delta] 2 is 55 to 90% in 60 to 85% is more preferable, and 65 to 80% is particularly preferable.
With respect to Δ1 or Δ2, the pressure resistance can be maintained while having good gas permeation performance by being in the above preferred range. When it is at least the lower limit value of the above preferred range, the gas permeation performance is good although the pressure resistance is not much changed. On the other hand, when it is below the upper limit of the above preferred range, the pressure resistance is good.
As Δ1 or Δ2 is larger, the resin layer containing a compound having an oxygen atom having a siloxane bond (the resin layer containing the compound having a siloxane bond functions as a layer having high separation selectivity so-called separation selectivity). It penetrates to the inside in the thickness direction. Here, when the resin layer containing a compound having a siloxane bond is the outermost layer of the gas separation membrane, “surface of the resin layer containing a compound having a siloxane bond” 6 in FIG. 4 (resin layer containing a compound having a siloxane bond) It is preferable that the surface on the opposite side of the support 4 is a position having a minimum value (Si ₀ ) of the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak. In addition, a resin containing a compound having a siloxane bond is also used when the resin layer containing a compound having a siloxane bond is not the outermost layer of the gas separation membrane, and other layers such as the additional resin layer 1 in FIG. The interface between the layer and another layer (such as the additional resin layer 1 in FIG. 2), that is, the “surface of the resin layer containing a compound having a siloxane bond” (the side opposite to the support 4 of the resin layer containing a compound having a siloxane bond) Of the Si ²⁺ and Si ³⁺ peaks is preferably a position having a minimum value (Si ₀ ) of the ratio of all Si peaks. In these cases, the surface of the resin layer containing a compound having a siloxane bond in the corona treatment or plasma treatment aiming only to improve the adhesion by modifying the surface, that is, the ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak From the position having the minimum value (Si ₀ ) to the depth of 10 nm or the depth of 20 nm, oxygen does not enter sufficiently to have gas separation selectivity. By making the resin layer containing the compound having a siloxane bond satisfy the preferable range of Δ1 or Δ2, at least one of gas permeability and gas separation selectivity under high pressure can be further increased. Without being bound by any theory, it is considered that separation selectivity can be expressed more by incorporating oxygen atoms not only into the surface of the resin layer containing the compound having a siloxane bond but also into the thickness direction.

(material)
In the gas separation membrane of the present invention, the compound having a siloxane bond described above preferably has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3).

In general formula (1), each R independently represents a hydrogen atom, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group, a fluorinated alkyl group, a vinyl group, an alkoxy group or a carboxyl group, and n is Represents an integer of 2 or more.
When such a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond, and the resin layer containing the compound having a siloxane bond is formed, high gas permeability and gas under high pressure Separation selectivity can be expressed.
Further, when a compound having a siloxane bond is used as a material for a resin layer containing a compound having a siloxane bond, and the resin layer containing the compound having a siloxane bond described above is formed, it is not bound by any theory. Not only the surface of the resin layer containing a compound containing a siloxane bond in the atoms but also the inside of the resin in the thickness direction to form a composition of SiOx, thereby exhibiting high gas permeability and gas separation selectivity under high pressure. it is conceivable that. In particular, even when polydimethylsiloxane, which is known for its high gas permeability, is used, it exhibits high gas permeability and separation selectivity under high pressure by using a resin layer containing the above-mentioned compound having a siloxane bond. can do. Not only the surface of the resin layer containing the compound having a siloxane bond but also the surface of the resin layer containing the compound having a siloxane bond and the thickness of the resin layer containing the compound having a siloxane bond. It is preferable that the compound having a siloxane bond has at least a repeating unit represented by the general formula (2) or a repeating unit represented by the general formula (3) inside in the direction.

In the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 10 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the compound having the siloxane bond described above is included in the resin layer including the compound having the siloxane bond at a depth of 10 nm from the surface of the resin layer including the compound having the siloxane bond. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 3.0 to 500 mol%. It is preferably 3.5 to 450 mol%, more preferably 4.0 to 400 mol%.
Furthermore, in the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 20 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the above-described compound having the siloxane bond included in the resin layer including the compound having the siloxane bond at a depth of 20 nm from the surface of the resin layer including the compound having the siloxane bond described above. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 2.0 to 400 mol%. Preferably, it is 2.5 to 350 mol%, more preferably 3.0 to 300 mol%.

(Characteristic)
Although there is no restriction | limiting in particular as thickness (synonymous with a film thickness) of the resin layer containing the compound which has a siloxane bond, It is preferable from a viewpoint of film forming ease that it is 0.1 micrometer or more. In the gas separation membrane of the present invention, the thickness of the resin layer containing a compound having a siloxane bond is preferably 150 to 900 nm, particularly preferably 0.1 to 4 μm, and preferably 0.3 to 3 μm. More particularly preferred. When the thickness of the resin layer containing the compound having a siloxane bond is in the above preferable range, the pressure resistance can be maintained while having good gas permeation performance. When it is at least the lower limit value of the above preferred range, the gas permeation performance is good although the pressure resistance is not much changed. On the other hand, when it is below the upper limit of the above preferred range, the pressure resistance is good. In a gas separation membrane having a resin layer containing a compound having a siloxane bond on a support, it is difficult to evaluate the thickness of each layer by SEM. Therefore, the measurement of the thickness of the resin layer containing the compound having a siloxane bond is confirmed from the analysis in the depth direction of TOF-SIMS. In the profile in the depth direction, with respect to the maximum intensity of the peak intensity derived from silicone (peak intensity of Si ³⁺ and Si ⁴⁺ ), the range where the peak intensity continuously present from the peak position is 90% or more is the film thickness Defined.
The film thickness of the resin layer containing the compound having a siloxane bond can be controlled by adjusting the coating amount of the curable composition. Moreover, as a method of controlling the thickness of the resin layer containing a compound having a siloxane bond, it can be controlled by adjusting the following parameters in accordance with the coating method. Viscosity of composition (coating liquid), solid content concentration, time to cure after coating, etc. For example, when applying by spin coating, the thickness of the resin layer containing a compound having a siloxane bond can also be controlled by adjusting the amount of coating solution and the spin coating rotation speed.

The polyimide compound is preferably a polyimide having a reactive group.

Specific examples of preferred polyimides having a reactive group that can be used in the present invention are listed below, but the present invention is not limited thereto. In the following formulae, “100”, “x”, and “y” represent copolymerization ratios (molar ratios). Examples of “x”, “y” and weight average molecular weight are shown in Table 3 below. In the polyimide compound that can be used in the present invention, y is preferably not 0.

[Method for producing gas separation membrane]
The method for producing the gas separation membrane of the present invention is not particularly limited.
In the method for producing a gas separation membrane of the present invention, it is preferable to perform a specific treatment on the resin layer precursor containing a compound having a siloxane bond. The specific treatment to be applied to the resin layer precursor containing a compound having a siloxane bond is preferably an oxygen atom permeation treatment in which oxygen atoms permeate the resin layer precursor containing a compound having a siloxane bond. It is more preferable that
The method for producing a gas separation membrane of the present invention includes an oxygen atom permeation treatment step for permeating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond, and the oxygen atom permeation treatment step described above includes an oxygen flow rate of 10 cm. ³ (STP) / min or more of the carrier gas is preferable and the plasma processing is preferably performed with an input power of 23 W or more.

A preferred configuration of the method for producing a gas separation membrane of the present invention will be described with reference to the drawings.
As shown in FIG. 5, the method for producing a gas separation membrane of the present invention is a resin containing a compound having a siloxane bond with respect to a laminate of a support 4 and a resin layer precursor 2 containing a compound having a siloxane bond. It is preferable to include a step of performing a specific treatment (oxygen atom permeation treatment 5) from one surface side of the layer precursor 2.
The method for producing a gas separation membrane of the present invention includes a step of forming an additional resin layer on a surface obtained by performing a specific treatment (oxygen atom permeation treatment 5) on a resin layer precursor containing a compound having a siloxane bond. It may be included (not shown).

<Formation of resin layer precursor containing compound having siloxane bond>
The method for producing a gas separation membrane of the present invention preferably includes a step of forming a resin layer precursor containing a compound having a siloxane bond on the aforementioned support.
The method for forming the resin layer precursor containing the compound having a siloxane bond on the support is not particularly limited, but a resin layer precursor material containing a compound having a siloxane bond and a composition containing an organic solvent are used. It is preferable to apply.
The solid content concentration (viscosity) of the composition is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, and particularly preferably 3 to 11% by mass. The higher the solid content concentration of the composition, the easier it is to make the resin layer containing the compound having a siloxane bond thinner.
The dropping amount of the composition is preferably 0.001 to 1 ml / cm ² , more preferably 0.002 to 0.5 ml / cm ² , and 0.005 to 0.05 ml / cm ² . It is particularly preferred. The smaller the amount of the composition dropped, the easier it is to make the resin layer containing the compound having a siloxane bond thinner.
There is no restriction | limiting in particular as a coating method of a composition, Although a well-known method can be used, For example, a spin coat method, a dip coat method, and a bar coat method can be used suitably. The spin coating rotation speed is preferably 100 to 10,000 rpm (round per minute), more preferably 500 to 2500 rpm, and particularly preferably 700 to 1500 rpm. The larger the spin coat rotation speed, the easier it is to make the resin layer containing the compound having a siloxane bond thinner.
The resin layer precursor material containing a compound having a siloxane bond and the composition containing an organic solvent are preferably curable compositions. The time until the composition is cured after application of the composition is preferably 0.01 to 60 minutes, more preferably 0.02 to 50 minutes, and particularly preferably 0.5 to 2 minutes. When the time until curing after application of the composition is in a preferable range, it is easy to obtain good adhesion to the support and good surface smoothness of the cured film.
Although there is no restriction | limiting in particular as a method of radiation irradiation to a curable composition when forming the resin layer containing the compound which has a siloxane bond, Electron beam, an ultraviolet-ray (UV), visible light, or infrared irradiation can be used. Depending on the material used, it can be appropriately selected.
The irradiation time is preferably 1 to 30 seconds.
The radiant energy (radiation intensity) is preferably 10 to 2000 mW / cm ² .

<Treatment of resin layer precursor containing a compound having a siloxane bond>
In the method for producing a gas separation membrane of the present invention, a specific treatment (oxygen atom permeation treatment) for infiltrating oxygen atoms (preferably from one surface side) is performed on a resin layer precursor containing a compound having a siloxane bond. And a minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peak in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond, preferably Δ1 and Δ2 respectively. It is more preferable to perform the specific process described above until the above range is reached.

Although there is no restriction | limiting in particular as a method of performing the above-mentioned specific process, For example, the method of performing plasma processing from the one surface side of the resin layer precursor containing the compound which has a siloxane bond can be mentioned.
The method for producing a gas separation membrane of the present invention includes an oxygen atom infiltration treatment step of infiltrating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
It is preferable that the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm ³ (STP) / min or more and an input power of 23 W or more.
For example, a method of performing the above-described plasma treatment for 5 to 30 seconds under the following conditions can be mentioned.
Plasma treatment conditions: oxygen flow rate 10 cm ³ (STP) / min or more, argon flow rate 100 cm ³ (STP) / min, input power (discharge output) 23 W or more.

{Fourth aspect}
A fourth mode that satisfies condition 4 will be described.

[Gas separation membrane]
The gas separation membrane of the present invention is a gas separation membrane having a resin layer containing a compound having a siloxane bond, and is obtained when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond. The three-component positron lifetime τ3 is 3.40 to 4.20 ns.
With such a configuration, the gas separation membrane of the present invention has high gas permeability at high pressure and / or gas separation selectivity. In the present invention, when the positron lifetime τ3 of the third component is 3.40 to 4.20 ns when a positron is injected from the surface of the resin layer containing a compound having a siloxane bond with an intensity of 1 keV, A gas separation membrane having at least one of gas permeability under high pressure and gas separation selectivity can be obtained.
The layer having separation selectivity is a film having a thickness of 1 to 30 μm, and the obtained film is carbon dioxide (at a temperature of 40 ° C., the total pressure on the gas supply side is set to 0.5 MPa. The ratio of the carbon dioxide permeability coefficient (PCO ₂ ) to the methane permeability coefficient (PCH ₄ ) (PCO ₂ / PCH ₄ ) when pure gases of CO ₂ ) and methane (CH ₄ ) are supplied is 1.5. It means the layer which becomes the above.
Conventionally, a layer having a polyimide compound has often been used as a layer having gas separation membrane separation selectivity, and a polyimide compound is obtained by having a resin layer containing a compound having a siloxane bond subjected to oxygen atom permeation treatment. The structure of the gas separation membrane of the present invention that does not have a layer and has at least one of gas permeability and gas separation selectivity under high pressure has not been known.
Here, the gas permeability and gas separation selectivity of the gas separation membrane are generally in a trade-off relationship. In other words, the gas separation membrane tends to decrease the gas separation selectivity when the gas permeability increases, and the gas separation selectivity tends to increase when the gas permeability decreases. Therefore, it has been difficult for conventional gas separation membranes to increase both gas permeability and gas separation selectivity. In contrast, the gas separation membrane of the present invention can increase both gas permeability and gas separation selectivity.
The gas separation membrane of the present invention preferably has a resin layer 3 containing a compound having a siloxane bond having a structure in which oxygen atoms are introduced from the surface with gradation as shown in FIG. 6B. Sites where oxygen atoms are introduced form pores by siloxane bonds. In addition, the introduction of oxygen reduces the thermal motion of the polymer. For this reason, the hole which can permeate | transmit many gas selectively has produced | generated. For this reason, unlike a resin layer containing a compound having a siloxane bond before the surface treatment (polydimethylsiloxane membrane 11 not subjected to the oxygen atom permeation treatment step as shown in FIG. 6A), high gas separation is achieved. Selectivity can be obtained.
Further, silica (a compound having a tetravalent silicon atom Si ⁴⁺ represented by general formula (1) described later) and silicone (a divalent or trivalent silicon represented by general formula (2) or (3) described later). By having a gradation structure as shown in FIG. 6 (B) in which atoms Si ²⁺ or Si ³⁺ are disturbed, adhesion at the silica / silicone interface is increased, and the film can be formed even at high CO ₂ partial pressure. High selectivity is maintained without being destroyed. The fact that the resin layer containing a compound having a siloxane bond has a gradation structure part in which silica and silicone are disturbed is related to the value of X / Y described below being in a preferable range.
In addition, polydimethylsilane in which oxygen atoms are uniformly introduced in the film thickness direction as shown in FIG. 6C without using gradation of oxygen atom introduction in the film thickness direction using a CVD (Chemical Vapor Deposition) method or the like. It is possible to produce a siloxane film. When such a membrane is compared with the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention, oxygen atoms are present in the resin layer 3 containing a compound having a siloxane bond of the gas separation membrane of the present invention. The densely introduced portion is thinner than the polydimethylsiloxane film 12 into which oxygen atoms are uniformly introduced in the film thickness direction. The polydimethylsiloxane membrane in which oxygen atoms are uniformly introduced in the film thickness direction is equal to the thickness of the portion where the oxygen atoms are densely introduced in the resin layer 3 containing a compound having a siloxane bond in the gas separation membrane of the present invention. It is difficult to make it thinner.
On the other hand, the gas separation membrane of the present invention can be designed to greatly increase gas permeability and lower gas separation selectivity. In addition, the gas separation membrane of the present invention can be designed to have low gas permeability and greatly increase gas separation selectivity. Even in these cases, if the gas separation membrane of the present invention has the same gas permeability as that of the conventional gas separation membrane, the gas separation membrane of the present invention is more gas selective than the conventional gas separation membrane. In addition, if the gas separation membrane of the present invention has the same gas separation selectivity as the conventional gas separation membrane, the gas separation membrane of the present invention has higher gas permeability than the conventional gas separation membrane. .
Hereinafter, preferred embodiments of the gas separation membrane of the present invention will be described.

<Resin layer containing a compound having a siloxane bond>
The gas separation membrane of the present invention has a resin layer containing a compound having a siloxane bond.

(Third component positron lifetime τ3)
The gas separation membrane of the present invention has a third component positron lifetime τ3 of 3.40 to 4.20 ns when a positron is injected at a strength of 1 keV from the surface of the resin layer containing the compound having a siloxane bond. It is preferably 3.40 to 4.11 ns, more preferably 3.40 to 4.10 ns, and particularly preferably 3.40 to 3.99.
The positron annihilation method is a method that utilizes the fact that positrons are extremely small and evaluates pores (free volume holes) having a diameter of about 1 to 10 nm, which is difficult to measure by other methods. The vacancies in the layer containing a polymer compound such as a polymer are analyzed by analyzing the third component, which is a long-life component of the positron lifetime spectrum, and measuring the positron lifetime τ3 of the third component (o-Ps). Can be calculated. Positrons combine with electrons in the polymer to form ortho-positronium o-Ps. This o-Ps is considered to be trapped in the vacancies and disappear. The lifetime τ ₃ of o-Ps at that time is expressed as a function of the radius R of the hole. The analysis of the positron lifetime can be performed using the nonlinear least square program POSITRONFIT. At the same time, the relative intensity I3 of the third component representing the porosity of the holes is also calculated.
In addition, when a positron beam device using an electron linear accelerator is used, it is possible to change the positron implantation energy, and it is possible to obtain information on the surface vacancies at a lower energy and at a higher energy. With an implantation energy of 1 keV, information of about 20 nm mainly from the surface in the depth direction can be obtained. With an implantation energy of 3 keV, information of 200 nm mainly from the surface in the depth direction can be obtained.
When the positron lifetime τ3 of the third component is 3.40 to 4.20 ns, for example, when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond, the compound having a siloxane bond is included. When averaged to about 20 nm in the depth direction (support direction) from the surface of the resin layer, pores having a pore diameter of 0.78 to 0.86 nm are expected to exist. A resin layer containing a compound having a siloxane bond is formed by having such pores having a diameter of about 20 nm in the depth direction (support direction) from the surface of the resin layer containing a compound having a siloxane bond. _In the separation of ₂ and CH ₄ , it has an appropriate pore size, and can improve both gas permeability and gas separation selectivity. Since it is actually a mixture of siloxane and silica, a relatively large pore size and a small pore size are blended, and it is thought that the ratio has changed.

The gas separation membrane of the present invention is a resin layer containing a compound having a siloxane bond having X as the third component positron lifetime τ3 when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond. Y is the positron lifetime τ3 of the third component when a positron is implanted at 3 keV from the surface of
0.88 ≦ X / Y ≦ 0.99
Is preferable from the viewpoint of increasing both gas permeability and gas separation selectivity,
0.88 ≦ X / Y ≦ 0.98
More preferably,
0.88 ≦ X / Y ≦ 0.97
It is particularly preferable to satisfy
With an implantation energy of 1 keV, information of about 20 nm mainly from the surface in the depth direction can be obtained. With an implantation energy of 3 keV, information of 200 nm mainly from the surface in the depth direction can be obtained.
If X / Y is less than 1, the higher the X / Y, the higher the resin layer containing a compound having a siloxane bond in the oxygen atom (the resin layer containing the compound having a siloxane bond has higher gas separation selectivity. It functions as a layer having so-called separation selectivity) and penetrates to the inside in the thickness direction. In the corona treatment or plasma treatment aiming only at improving the adhesion by modifying the surface, oxygen does not sufficiently enter from the surface of the resin layer containing a compound having a siloxane bond to a sufficient depth so as to have gas separation selectivity.

(Relative strength of third component I3)
The gas separation membrane of the present invention has a gas permeability that the relative intensity I3 of the third component is 13 to 41% when a positron is injected at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond. From the viewpoint of increasing both gas separation selectivity, it is preferably 13 to 40%, more preferably 13 to 39%, and particularly preferably 13 to 33%.
The relative intensity I3 of the third component represents the porosity of free holes (free volume holes). When the relative intensity I3 of the third component when a positron is shot at a strength of 1 keV from the surface of the resin layer containing a compound having a siloxane bond is, for example, 13 to 41%, the resin layer containing the compound having a siloxane bond It is expected that the porosity at about 20 nm in the depth direction (support direction) from the surface is 13 to 41%. Since the porosity at about 20 nm in the depth direction (support direction) from the surface of the resin layer containing a compound having a siloxane bond is in such a range, the resin layer containing a compound having a siloxane bond is CO ₂ and In the separation of CH ₄ , it has an appropriate porosity, and can improve both gas permeability and gas separation selectivity.

(material)
The resin layer containing a compound having a siloxane bond includes a compound having a siloxane bond. The compound having a siloxane bond may be “a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom”. The compound having a siloxane bond may be a “compound having a siloxane bond and having a repeating unit”, and among them, a compound having a polysiloxane unit is preferable.

In the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 10 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the compound having the siloxane bond described above is included in the resin layer including the compound having the siloxane bond at a depth of 10 nm from the surface of the resin layer including the compound having the siloxane bond. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 3.0 to 500 mol%. It is preferably 3.5 to 450 mol%, more preferably 4.0 to 400 mol%.
Furthermore, in the gas separation membrane of the present invention, the resin layer containing the compound having the siloxane bond described above at a depth of 100 nm from the surface of the resin layer containing the compound having the siloxane bond is represented by the general formula (1). And a compound having a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). In the gas separation membrane of the present invention, the compound having the siloxane bond described above is included in the resin layer including the compound having the siloxane bond at a depth of 100 nm from the surface of the resin layer including the compound having the siloxane bond. The ratio of the repeating unit represented by the general formula (3) to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 2.0 to 400 mol%. Preferably, it is 2.5 to 350 mol%, more preferably 3.0 to 300 mol%.

(Thickness)
The film thickness (synonymous with the thickness) of the resin layer containing a compound having a siloxane bond is not particularly limited, but the thickness of the resin layer containing the compound having a siloxane bond is 0.1 μm or more. From the viewpoint of ease, it is preferably 0.1 to 5 μm, more preferably 0.1 to 4 μm, and particularly preferably 0.3 to 3 μm. The thickness of the resin layer containing a compound having a siloxane bond can be determined by SEM.
When the film thickness of the resin layer containing a compound having a siloxane bond is made thinner than the above upper limit, the effect of expanding the pore diameter due to the CO ₂ swelling of the resin layer containing the compound having a siloxane bond can be suppressed, and gas separation selection can be performed. A tendency to increase sex has been observed.
The thickness of the resin layer containing the compound having a siloxane bond can be controlled by adjusting the coating amount of the curable composition.

The polyimide compound is preferably a polyimide having a reactive group.

Specific examples of preferred polyimides having a reactive group that can be used in the present invention are listed below, but the present invention is not limited thereto. In the following formulae, “100”, “x”, and “y” represent copolymerization ratios (molar ratios). Examples of “x”, “y” and weight average molecular weight are shown in Table 4 below. In the polyimide compound that can be used in the present invention, y is preferably not 0.

(Characteristic)
The thickness of the additional resin layer is preferably a thin film as much as possible under the condition of imparting high gas permeability while maintaining mechanical strength and gas separation selectivity.

From the viewpoint of enhancing gas permeability, the additional resin layer other than the resin layer containing the compound having a siloxane bond of the gas separation membrane of the present invention is preferably a thin layer. The thickness of the additional resin layer other than the resin layer containing the compound having a siloxane bond is usually 10 μm or less, preferably 3 μm or less, particularly preferably 1 μm or less, and preferably 0.3 μm or less. More particularly preferred, it is even more particularly preferred that it is 0.2 μm or less.
The thickness of the additional resin layer other than the resin layer containing the compound having a siloxane bond is usually 0.01 μm or more, and is practically preferably 0.03 μm or more from the viewpoint of film formation, More preferably, it is 1 μm or more.

(Characteristic)
The thickness of the protective layer is preferably 20 nm to 3 μm, more preferably 50 nm to 2 μm, and particularly preferably 100 nm to 1 μm.

In particular, when the gas to be separated is a mixed gas of carbon dioxide and methane, the carbon dioxide permeation rate at 40 ° C. and 6 MPa is preferably 10 GPU or more, more preferably 10 to 300 GPU. 15 to 300 GPU is particularly preferable, and 30 to 300 GPU is more preferable.
1 GPU is 1 × 10 ⁻⁶ cm ³ (STP) / cm ² · sec · cmHg.

The gas separation membrane of the present invention is a gas separation selection which is a ratio of the permeation flux of carbon dioxide to the permeation flux of methane at 40 ° C. and 6 MPa when the gas to be separated is a mixed gas of carbon dioxide and methane. The property α is preferably 30 or more, more preferably 35 or more, particularly preferably 40 or more, and particularly preferably 50 or more.

[Method for producing gas separation membrane]
The method for producing the gas separation membrane of the present invention is not particularly limited.
In the method for producing a gas separation membrane of the present invention, it is preferable to perform a specific treatment on the resin layer precursor containing a compound having a siloxane bond. The specific treatment to be applied to the resin layer precursor containing a compound having a siloxane bond is preferably an oxygen atom permeation treatment in which oxygen atoms permeate the resin layer precursor containing a compound having a siloxane bond. It is more preferable that
The method for producing a gas separation membrane of the present invention is preferably the following method for producing a gas separation membrane of the present invention.
The method for producing a gas separation membrane of the present invention includes an oxygen atom permeation treatment step for permeating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond, and the oxygen atom permeation treatment step described above includes an oxygen flow rate of 45 cm ^3. (STP) / Plasma treatment using a carrier gas of at least min and using anode coupling at an input power of 23 W or more.

<Formation of resin layer precursor containing compound having siloxane bond>
The method for producing a gas separation membrane of the present invention preferably includes a step of forming a resin layer precursor containing a compound having a siloxane bond on the aforementioned support.
The method for forming the resin layer precursor containing the compound having a siloxane bond on the support is not particularly limited, but a resin layer precursor material containing a compound having a siloxane bond and a composition containing an organic solvent are used. It is preferable to apply. The coating method is not particularly limited, and a known method can be used. For example, a spin coating method, a dip coating method, or a bar coating method can be appropriately used.
The resin layer precursor material containing a compound having a siloxane bond and the composition containing an organic solvent are preferably curable compositions. Although there is no restriction | limiting in particular as a method of radiation irradiation to a curable composition when forming the resin layer containing the compound which has a siloxane bond, Electron beam, an ultraviolet-ray (UV), visible light, or infrared irradiation can be used. Depending on the material used, it can be appropriately selected.
The irradiation time is preferably 1 to 30 seconds.
The radiant energy is preferably 10 to 2000 mW / cm ² .

<Treatment of resin layer precursor containing a compound having a siloxane bond>
In the method for producing a gas separation membrane of the present invention, a specific treatment (oxygen atom permeation treatment) for infiltrating oxygen atoms (preferably from one surface side) is performed on a resin layer precursor containing a compound having a siloxane bond. Preferably, the process includes the steps described above until the positron lifetime τ3 of the third component is 3.40 to 4.20 ns when a positron is injected at a strength of 1 keV from the surface of the resin layer containing the compound having a siloxane bond. It is more preferable to perform a specific process.

Although there is no restriction | limiting in particular as a method of performing the above-mentioned specific process, For example, the method of performing plasma processing from the one surface side of the resin layer precursor containing the compound which has a siloxane bond can be mentioned.
The method for producing a gas separation membrane of the present invention includes an oxygen atom infiltration treatment step of infiltrating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
The above-described oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 45 cm ³ (STP) / min or more and using anode coupling at an input power of 23 W or more.
For example, a method of performing the above-described plasma treatment for 5 to 30 seconds under the following conditions can be mentioned.
Plasma treatment conditions: oxygen flow rate 45 cm ³ (STP) / min or more, argon flow rate 100 cm ³ (STP) / min, input power (discharge output) 23 W or more, anode coupling.

The plasma treatment applied to the present invention includes a mode in which a low-pressure plasma is used to generate a stable plasma, and an object to be processed is processed in a large vacuum chamber. Recently, an atmospheric pressure plasma processing apparatus capable of processing in an atmospheric pressure atmosphere has been developed. In this case, gas can be introduced into the process chamber and high-density plasma can be stably generated under an atmospheric pressure atmosphere. Examples of the system configuration of the atmospheric pressure plasma processing apparatus include a system composed of a gas mixing / control unit, a reactor, and a transfer conveyor (or XY table). There has also been proposed a method in which a plasma jet is blown out in a spot manner from a circular nozzle.
As plasma treatment conditions, the argon flow rate is preferably 5 to 500 cm ³ (STP) / min, more preferably 50 to 200 cm ³ (STP) / min, and 80 to 120 cm ³ (STP) / min. It is particularly preferred. In the manufacturing method of the gas separation membrane of the present invention, the oxygen flow 45cm ³ (STP) / min or ^more, it is ^{preferably, 50 ~ 100cm 3 (STP)} / min is 50cm 3 (STP) / min or more It is more preferable.
As plasma treatment conditions, the degree of vacuum is preferably 0.6 to 100 Pa, more preferably 1 to 60 Pa, and particularly preferably 2 to 40 Pa.
In the method for producing a gas separation membrane of the present invention, as plasma treatment conditions, the input power (discharge output) is 23 W or more, preferably 23 to 1000 W, more preferably 40 to 1000 W, more preferably 110 to Particularly preferred is 500 W.
In the method for producing a gas separation membrane of the present invention, it is preferable to use anode coupling as the plasma treatment condition from the viewpoint of gas separation selectivity.
Corona treatment or the like can be used instead of plasma treatment.

Hereinafter, the present invention will be described more specifically by way of examples and comparative examples (note that comparative examples are not known techniques). The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.
In the text, “parts” and “%” are based on mass unless otherwise specified.

{First aspect}
First, the Example of the 1st aspect which satisfy | fills the conditions 1 is shown.

[Example 1]
<Preparation of resin layer precursor liquid containing a compound having a siloxane bond>
(Preparation of radiation curable polymer having dialkylsiloxane group)
In a 150 ml three-necked flask, 39 g of UV9300 (manufactured by Momentive), 10 g of X-22-162C (manufactured by Shin-Etsu Chemical Co., Ltd.), DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) 0.007 g was added and dissolved in 50 g of n-heptane. This was maintained at 95 ° C. for 168 hours to obtain a radiation curable polymer solution having a poly (siloxane) group (viscosity of 22.8 mPa · s at 25 ° C.).

(Preparation of polymerizable radiation curable composition)
5 g of the radiation curable polymer solution cooled to 20 ° C. was diluted with 95 g of n-heptane. To the obtained solution, 0.5 g of UV9380C (manufactured by Momentive) as a photopolymerization initiator and 0.1 g of organics TA-10 (manufactured by Matsumoto Fine Chemical) are added, and a polymerizable radiation curable composition is prepared. Prepared.

<Formation of resin layer precursor containing compound having siloxane bond>
PAN (polyacrylonitrile) porous film (Polyacrylonitrile porous film is present on the nonwoven fabric, including the nonwoven fabric, the film thickness is about 180 μm) The spin-coated polymerizable radiation curable composition as a support, and then the UV intensity UV treatment (Fusion UV System, Light Hammer 10, D-bulb) was performed under UV treatment conditions of 9 kW / m ² and UV irradiation time of 10 seconds, and then dried. In this way, a resin layer precursor containing a compound having a siloxane bond having a dialkylsiloxane group and having a siloxane bond having a thickness of 1 μm was formed on the porous support.

<Oxygen atom permeation treatment of a resin layer precursor containing a compound having a siloxane bond-plasma treatment->
Put porous support to form a resin layer precursor comprising a compound having a siloxane bond to the desktop vacuum plasma apparatus (UTEC Corporation), the oxygen flow rate 20 cm ³ of carrier gas conditions (STP) / min, argon flow rate 100 cm ³ ( STP) / min, the degree of vacuum was 30 Pa, the input power was 25 W, and the plasma treatment was performed for a treatment time of 10 seconds.
The obtained composite membrane was used as the gas separation membrane of Example 1.

(Calculation of the number of silicon atoms, oxygen atoms and carbon atoms in a resin layer containing a compound having a siloxane bond)
A compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond is sampled by sampling the center of the porous support on which the resin layer containing the compound having a siloxane bond has been subjected to plasma treatment. O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing to the number of silicon atoms, and the number of oxygen atoms on the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms The ratio O / Si (B) was calculated using ESCA (Electron Spectroscopy FOR Chemical Analysis).
A porous support formed with a resin layer containing a compound having a siloxane bond was obtained from Physical Electronics, Inc. Included in Quantera SXM manufactured by the company, X-ray source: Al—Kα ray (1490 eV, 25 W, diameter of 100 μm), measurement area: 300 μm × 300 μm, Pass Energy 55 eV, Step 0.05 eV, including a compound having a siloxane bond The O / Si ratio (B), which is the ratio of the number of oxygen atoms on the surface of the resin layer to the number of silicon atoms, was calculated. The carbon / silicon ratio, which is the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond, was also calculated in the same manner.
Subsequently, an O / Si ratio (A) which is a ratio of the number of oxygen atoms contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms (A ) Was performed with C ₆₀ ions. That is, Physical Electronics, Inc. The ion beam intensity was C ₆₀ ⁺ : 10 keV, 10 nA, and a 2 mm × 2 mm region was etched by 10 nm with a Quantera SXM attached C ₆₀ ion gun. An ESCA apparatus was used for this film to calculate an O / Si ratio (A) that is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing a compound having a siloxane bond. The depth of the resin layer containing the compound having a siloxane bond from the surface of the resin layer containing the compound having a siloxane bond was calculated from the etching rate of 10 nm / min of the resin layer material containing the compound having a siloxane bond. This value can be obtained every time the material changes, and the optimum value for the material is used as appropriate.
O / Si ratio (A) which is the ratio of the number of oxygen atoms of the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond to the number of silicon atoms And the value of A / B is calculated from the O / Si ratio (B), which is the ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond, 6.
Similar to the O / Si ratio (A), which is the ratio of the number of oxygen atoms to the number of silicon atoms in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. O / Si ratio (C), which is the ratio of the number of oxygen atoms in the resin layer containing a compound having a siloxane bond at a depth of 30 nm from the surface of the resin layer containing a compound having a siloxane bond to the number of silicon atoms Asked. Moreover, the value of C / B was computed from O / Si ratio (B) and O / Si ratio (C), and it described in Table 5 and Table 6 below. Tables 5 and 6 below show the values of the carbon / silicon ratio, which is the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
The surface of the resin layer containing the compound having a siloxane bond has the maximum O / Si ratio when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% ( Atomic%) or more. Method for obtaining O / Si ratio (A), which is the ratio of the number of oxygen atoms to the number of silicon atoms in a resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing a compound having a siloxane bond In the same way as above, when the O / Si ratio is measured from the surface of the gas separation membrane, the surface where the O / Si ratio is maximum and the number of silicon atoms is 3% (atomic%) or more is specified. did.
As a result, in the above-described method, a compound having a siloxane bond in a state where a resin layer containing a compound having a siloxane bond is formed on the porous support (a state in which no other layer (for example, a layer containing polyimide) is present). The surface of the resin layer containing “the O / Si ratio is maximum when the O / Si ratio is measured from the surface of the gas separation membrane, and the number of silicon atoms is 3% (Atomic%) or more. Surface ".

The surface of the resin layer containing a compound having a siloxane bond is a repeating unit represented by the general formula (1) and a repeating unit represented by at least the general formula (2) or the general formula (3). It was confirmed by the following method that a compound having a siloxane bond having a unit was included.
The Si2p spectrum was measured by ESCA, and the valence of Si (Si ²⁺ , Si ³⁺ and Si ⁴⁺ ) was separated and quantified from the curve fitting of the obtained peak.
The repeating unit represented by the general formula (2) of the repeating unit represented by the general formula (3) and the general formula (1) in the compound having a siloxane bond included in the surface of the resin layer containing the compound having a siloxane bond. It was confirmed by a similar method that the ratio to the repeating unit represented by) was 100 to 600 mol% in Examples 1 to 8 and 100 to 500 mol% in Examples 9 to 12.
A resin layer containing a compound having a siloxane bond at a depth of 10 nm and 30 nm from the surface of the resin layer containing a compound having a siloxane bond is a repeating unit represented by the general formula (1) and at least the general formula (2) It was confirmed by the following method that it contains a compound having a siloxane bond having a repeating unit represented by formula (3) or a repeating unit represented by formula (3).
The Si2p spectrum was measured by ESCA using the same etching treatment as in Example, and the valences of Si (Si ²⁺ , Si ³⁺ and Si ⁴⁺ ) were separated and quantified from the curve fitting of the obtained peaks.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 500 mol% in Examples 1 to 8, while 5 to 400 in Examples 9 to 12. It was confirmed by the same method that it was mol%.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 30 nm from the surface of the resin layer containing the compound having a siloxane bond The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 400 mol% in Examples 1 to 8, while 5 to 300 in Examples 9 to 12. It was confirmed by the same method that it was mol%.

[Examples 2 to 8]
In Example 1, the input power of the plasma treatment of the resin layer precursor containing the compound having a siloxane bond was changed from 25 W as shown in the following table, respectively. A gas separation membrane was obtained.

[Examples 9 to 10]
Example 8 was the same as Example 8 except that the resin layer precursor material containing a compound having a siloxane bond was changed from PDMS to Polydiphenyl siloxane and Poly [methyl (3,3,3-trifluoropropyl) siloxane], respectively. Thus, gas separation membranes of Examples 9 to 10 were obtained.
Polyphenyl siloxane is available under the trade name 482153 manufactured by Sigma Aldrich, and Poly [methyl (3,3-trifluoropropyl) siloxane] (abbreviated as PMTFPS) is available under the trade name 48 available from Sigma Aldrich 45. Use.

[Example 11]
In Example 4, after the oxygen atom permeation treatment, a polymerizable radiation curable composition was further spin-coated on the resin layer containing the compound having a siloxane bond, and the UV intensity was 24 kW / m and the treatment time was 10 seconds. The sample was subjected to UV treatment (Fusion UV System, Light Hammer 10, D-bulb) under the following UV treatment conditions, and then dried. In this way, a resin layer precursor containing a compound having a siloxane bond as a second layer having a thickness of 1 μm was formed.
A porous support on which a resin layer precursor containing a compound having a siloxane bond in the second layer is formed is placed in a desktop vacuum plasma apparatus (manufactured by YOUTEC), the carrier gas conditions are oxygen flow rate 20 cm ³ (STP) / min, argon A plasma treatment, which is a second oxygen atom infiltration treatment, was performed at a flow rate of 100 cm ³ (STP) / min, a degree of vacuum of 30 Pa, an input power of 100 W, and a treatment time of 10 seconds.
The obtained gas separation membrane was used as the gas separation membrane of Example 11.

[Example 12]
In Example 11, after the second oxygen atom permeation treatment was performed on the resin layer precursor containing a compound having a siloxane bond in the second layer, the resin layer containing a compound having a siloxane bond in the second layer was applied. Further, a polymerizable radiation curable composition was spin-coated, and subjected to UV treatment (Fusion UV System, Light Hammer 10, D-bulb) under UV treatment conditions with a UV intensity of 24 kW / m and a treatment time of 10 seconds. Dried. In this way, a resin layer precursor containing a compound having a siloxane bond as a third layer having a thickness of 1 μm was formed.
A porous support formed with a resin layer containing a compound precursor having a siloxane bond in the third layer is placed in a desktop vacuum plasma apparatus (manufactured by YOUTEC), and the carrier gas conditions are oxygen flow rate 20 cm ³ (STP) / min, argon The flow rate was 100 cm ³ (STP) / min, the degree of vacuum was 30 Pa, the input power was 100 W, and the plasma treatment, which is the third oxygen atom infiltration treatment, was performed in a treatment time of 10 seconds.
The obtained gas separation membrane was used as the gas separation membrane of Example 12.

[Comparative Example 1]
In Example 1, a gas separation membrane of Comparative Example 1 was obtained in the same manner as in Example 1 except that the input power for plasma treatment of the resin layer precursor containing a compound having a siloxane bond was changed from 25 W to 10 W.

[Comparative Example 2]
A gas separation membrane of Comparative Example 2 was obtained in the same manner as in Example 1, except that the carrier gas condition was changed from 20 cm ³ (STP) / min to 0 cm ³ (STP) / min in Example 1.

[Comparative Example 3]
Based on the technique described in Journal of Membrane Science 99 (1995) 139-147, a polydimethylsiloxane film was treated with 5 W for 120 seconds under an Ar atmosphere to produce a composite film. The obtained composite membrane was evaluated in the same manner as in Example 1. A stainless steel cell made of SUS316 (manufactured by DENISSEN) having high pressure resistance was used to adjust the cell temperature to 30 ° C., and gas separation performance was evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 6:94 is adjusted so that the total pressure on the gas supply side is 5 MPa (CO ₂ partial pressure: 0.65 MPa), and CO 2 _{When an} attempt was made to measure the gas permeability of each of ₂ and CH ₄ by TCD detection type gas chromatography, the pressure could not be maintained.

[Comparative Example 4]
Based on the method described in Journal of Membrane Science 440 (2013) 1-8, the polydimethylsiloxane film was subjected to atmospheric pressure plasma treatment to produce a composite film. The obtained composite membrane was evaluated in the same manner as in Example 1. Using a SUS316 stainless steel cell (DENISSEN) having high-pressure resistance, the cell temperature was adjusted to 30 ° C., and the gas separation performance was evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 6:94 is adjusted so that the total pressure on the gas supply side is 5 MPa (CO ₂ partial pressure: 0.65 MPa), and CO 2 _{When an} attempt was made to measure the gas permeability of each of ₂ and CH ₄ by TCD detection type gas chromatography, the pressure could not be maintained.

[Example 13]
<Preparation of additional resin layer>
(Synthesis of polymer (P-101))
A polymer (P-101) was synthesized according to the following reaction scheme.

Synthesis of polymer (P-101):
N-methylpyrrolidone 123 ml, 6FDA (manufactured by Tokyo Chemical Industry Co., Ltd., product number: H0771) 54.97 g (0.124 mol) was added to a 1 L three-necked flask and dissolved at 40 ° C. and stirred under a nitrogen stream. 2,3,5,6-tetramethylphenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1457) 4.098 g (0.0248 mol), 3,5-diaminobenzoic acid 15.138 g (0.0992 mol) Of N-methylpyrrolidone in an amount of 84.0 ml was added dropwise over 30 minutes while maintaining the system at 40 ° C. After stirring the reaction solution at 40 ° C. for 2.5 hours, 2.94 g (0.037 mol) of pyridine (manufactured by Wako Pure Chemical Industries, Ltd.), 31.58 g (0.31 mol) of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) Each was added and further stirred at 80 ° C. for 3 hours. Thereafter, 676.6 mL of acetone was added to the reaction solution for dilution. The acetone dilution liquid of the reaction liquid was dripped at the place which added methanol 1.15L and acetone 230mL to the 5L stainless steel container and stirred. The obtained polymer crystals were suction filtered and blown dry at 60 ° C. to obtain 50.5 g of polymer (P-101). This polymer (P-101) is the same as the above-described exemplified polyimide compound P-100 with X: Y = 20: 80. In Table 6 below, the polymer (P-101) is abbreviated as PI.

(Formation of additional resin layer)
In a 30 ml brown vial, 1.4 g of polymer (P-101) and 8.6 g of methyl ethyl ketone were mixed and stirred at 25 ° C. for 30 minutes. Thereafter, the stirred solution was spin-coated on the plasma-treated surface of the resin layer containing a compound having a siloxane bond in the same manner as in Example 5 to form an additional resin layer having a thickness of 150 nm to obtain a gas separation membrane.
The obtained separation membrane was used as the gas separation membrane of Example 13.

[Example 14]
An additional resin layer is formed in the same manner as in Example 13 except that a resin layer containing a compound having a siloxane bond, which is obtained by plasma-treating a resin layer containing a compound having a siloxane bond under the same conditions as in Example 6, A gas separation membrane of Example 14 was obtained.

[Example 15]
An additional resin layer is formed in the same manner as in Example 13 except that a resin layer containing a compound having a siloxane bond obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 7 is used. A gas separation membrane of Example 15 was obtained.

[Evaluation]
<Evaluation of gas separation performance of gas separation membrane>
In each of the gas separation membranes of the Examples and Comparative Examples, which are the obtained thin-layer composite membranes, evaluation was performed using a high-pressure resistant SUS316 stainless steel cell (DENISSEN) and adjusting the cell temperature to 30 degrees. did. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 6:94 is adjusted so that the total pressure on the gas supply side is 5 MPa (CO ₂ partial pressure: 0.65 MPa), and CO 2 The gas permeability of each of ₂ and CH ₄ was measured by TCD detection type gas chromatography. The gas separation selectivity of the gas separation membrane of each Example and Comparative Example was calculated as the ratio of the CO ₂ permeability coefficient P _{CO2 to} the CH ₄ permeability coefficient P _CH4 of this membrane (P _CO2 / P _CH4 ). The CO ₂ permeability of the gas separation membrane of each Example and Comparative Example was defined as the CO ₂ permeability Q _CO2 (unit: GPU) of this membrane.
The unit of gas permeability is a GPU (GPU) unit [1 GPU = 1 × 10 ⁻⁶ cm ³ (STP) / cm ² ) representing a permeation flux (also referred to as permeability, permeability, and Permeance) per pressure difference. · Sec · cmHg] or a barrer unit (1 barrer = 1 × 10 ⁻¹⁰ cm ³ (STP) · cm / cm ² · sec · cmHg) representing a transmission coefficient. In this specification, the unit of GPU is represented by the symbol Q, and the unit of barrer is represented by the symbol P.
When the gas permeability (CO ₂ permeability Q _CO2 ) is 30 GPU or more and the gas separation selectivity is 40 or more, the evaluation is AA,
When the gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and less than 30 GPU and the gas separation selectivity is 30 or more and less than 40, the evaluation is A,
The gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and the gas separation selectivity is less than 30, or the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is 30 or more. If so, the evaluation is B,
When the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is less than 30, or the pressure is not applied (the pressure cannot be maintained) and the test cannot be performed. Was rated C.

From Table 5 and Table 6 above, when the value of B is lower than the lower limit specified in the present invention (Comparative Example 1) and when the value of A / B is lower than the lower limit specified in the present invention (Comparative Example 2). In comparison, it was found that the gas separation membrane of the present invention has high gas permeability (CO ₂ permeability) and gas separation selectivity under high pressure.

[Examples 16 to 19]
From the following Examples 16 to 19, it was found that the storage resistance and wet heat resistance were improved by reducing the flowable PDMS. Details are described below.
A polymerizable radiation-curable composition containing PDMS as a compound having a siloxane bond having a thickness of 600 nm was applied on a PAN porous support in the same manner as in Example 6 and described in Table 7 below. In this way, samples having different gel fractions were prepared by changing the UV irradiation conditions.
Specifically, from the UV processing conditions of Example 1 made by Fusion UV System, Light Hammer 10, UV intensity of 9 kW / m ² using a D-bulb, and UV irradiation time of 10 seconds, the same apparatus was used to obtain a UV integrated light amount ( Adjustment was made by changing the irradiation intensity of the UV-A irradiation lamp so that the integrated energy amount was a value shown in Table 7 below.
Thereafter, samples having different gel fractions and subjected to plasma treatment under the conditions shown in Table 7 below, which are similar to those of Example 6, were used as gas separation membranes of Examples 16-19.
About the obtained gas separation membrane, the characteristic was evaluated similarly to Example 1, and the obtained result was described in following Table 7.

<Gel fraction>
Separately prepare a sample for gel fraction measurement up to UV irradiation in the same manner as the gas separation membranes of Examples 16 to 19, and measure the gel fraction of the resin layer containing the compound having a siloxane bond by the following method. did.
A sample for gel fraction measurement having a resin layer containing a compound having a siloxane bond on a support was cut out to prepare a sample. The sample was immersed in a chloroform solvent for 24 hours, and the signal intensity of the Si component in XRF (X-ray fluorescence analysis) before and after immersion was measured.
XRF was measured using an XRF-1700 (trade name, manufactured by Shimadzu Corporation) as a measuring device, with an X-ray voltage / current of 40 kV / 95 mA, a diaphragm of 30 mmφ (diameter), and a sample mask of 30 mmφ (diameter).
When the signal intensity of the Si component of the sample before immersion was Xa and the signal intensity of the Si component of the sample after immersion was Xb, Xb / Xa * 100 (%) was taken as the gel fraction of the gas separation membrane. In the case of producing a gas separation membrane, the polymerizable radiation-curable composition soaks in a certain amount into the support, and the rest forms a resin layer containing a compound having a siloxane bond. When the sample is immersed in a chloroform solvent, in XRF, UV of both a polymerizable radiation curable composition soaked in a support and a polymerizable radiation curable composition in which a resin layer containing a compound having a siloxane bond is formed. The components that have not been gelled by irradiation distill off, leaving the gelled components. Xa and Xb continuously measure the signal intensity of the Si component in the depth direction from the surface of the resin layer containing the compound having a siloxane bond to the opposite surface of the support, and the Si component in the depth direction This is the sum of the signal intensities.
The obtained results are shown in Table 7 below.
The gas separation performance, storage resistance, and wet heat resistance were evaluated using a sample that was plasma-treated without being immersed in the chloroform solvent.

<Storage resistance>
Storage resistance was evaluated according to the following criteria, comparing the results of gas permeability evaluation immediately after plasma treatment with the results of gas permeability evaluation of samples placed at room temperature in a 50% environment for 2 weeks.
The gas permeability changed by 50% or more was designated as B, and the gas permeability changed by less than 50% was designated as A.
The obtained results are shown in Table 7 below.

<Humidity heat resistance>
Wet heat (transport) resistance was evaluated according to the following criteria, comparing the results of gas permeability evaluation immediately after plasma treatment with the results of gas permeability evaluation of a sample placed at 70 ° C and 65% for 2 weeks. did.
The gas permeability changed by 50% or more was designated as B, and the gas permeability changed by less than 50% was designated as A.
The obtained results are shown in Table 7 below.

As the results shown in Table 7 above, when the gel fraction of the gas separation membrane was 45% or more, the storage resistance was good. Further, when the gel fraction was 55% or more, the wet heat resistance was good in addition to the storage resistance.

[Examples 101 to 119]
-modularization-
Using the gas separation membranes produced in Examples 1 to 19, spiral type modules were produced with reference to [0012] to [0017] of JP-A-5-168869. The obtained gas separation membrane modules were designated as gas separation membrane modules of Examples 101 to 119.
It was confirmed that the produced gas separation membrane modules of Examples 101 to 119 were good according to the performance of the built-in gas separation membrane.
The produced gas separation membrane modules of Examples 101 to 119 are leaves (the leaf is a portion of the gas separation membrane folded in an envelope shape in which the space on the transmission side is connected to the central tube in the spiral type module). 10 points of 1 cm × 1 cm are sampled randomly from within 10 cm × 10 cm of the center of one side, and the element ratio in the surface and depth direction is calculated according to the method of Example 1, and built-in at 9 points or more out of 10 points. It was confirmed that it was as per the separation membrane. Moreover, it was confirmed that the spiral module was good according to the performance of the built-in gas separation membrane.

{Second aspect}
The Example of the 2nd aspect which satisfy | fills the conditions 2 is shown.

[Example 1001]
<Preparation of polymerizable radiation-curable composition for forming a resin layer precursor containing a compound having a siloxane bond>
(Preparation of radiation curable polymer having dialkylsiloxane group)
In a 150 ml three-necked flask, 39 g of UV9300 (manufactured by Momentive), 10 g of X-22-162C (manufactured by Shin-Etsu Chemical Co., Ltd.), DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) 0.007 g was added and dissolved in 50 g of n-heptane. This was maintained at 95 ° C. for 168 hours to obtain a radiation curable polymer solution having a poly (siloxane) group (viscosity of 22.8 mPa · s at 25 ° C.).

(Preparation of polymerizable radiation curable composition)
The radiation curable polymer solution cooled to 20 ° C. was diluted with n-heptane so that the solid content was 10% by mass. To the obtained solution, 0.5 g of IO591 (manufactured by Tokyo Chemical Industry Co., Ltd.) that is a photopolymerization initiator and 0.1 g of titanium isoporopoxide (manufactured by aldrich) are added, and a polymerizable radiation-curable composition is obtained. Prepared.

<Formation of resin layer precursor containing compound having siloxane bond>
PAN (Polyacrylonitrile) porous membrane (Polyacrylonitrile porous membrane is present on the nonwoven fabric, including the nonwoven fabric, the thickness is 200 μm) As a porous support, the polymerizable radiation curable composition is 3000 rpm, the dropping amount is 0.04 ml. After spin coating under the conditions of / cm ² , it was stored at room temperature for 30 min. Thereafter, the polymerizable radiation curable composition was subjected to UV treatment (Fusion UV System, Light Hammer 10, D-bulb) under UV treatment conditions of a UV intensity of 24 kW / m ² and a UV irradiation time of 10 seconds to form a siloxane bond. The resin layer precursor containing a compound having the following was cured. Of the PAN porous membrane, a region in which the compound having a siloxane bond is hardly filled becomes the porous support A, and the remaining region is present in the porous support B of the resin layer containing the compound having a siloxane bond. It became area | region GLi.
Thus, the region GLi (thickness 200 nm) present in the porous support B of the resin layer containing the compound having a siloxane bond and the porous support B of the resin layer containing the compound having a siloxane bond exist. A resin layer precursor containing a compound having a siloxane bond including a region GLe (thickness 140 nm) to be formed was formed.

<Oxygen atom permeation treatment of a resin layer precursor containing a compound having a siloxane bond-plasma treatment->
A porous support A on which a resin layer precursor containing a compound having a siloxane bond is formed is placed in a desktop vacuum plasma apparatus (manufactured by Utec Co., Ltd.), the carrier gas conditions are an oxygen flow rate of 20 cm ³ (STP) / min, and an argon flow rate of 100 cm ^3. Plasma treatment was performed at (STP) / min, a degree of vacuum of 30 Pa, an input power of 150 W, and a treatment time of 10 seconds.
The obtained composite membrane was used as the gas separation membrane of Example 1001.

(Calculation of GLe and GLi)
The thickness of the gas separation membrane of each Example and Comparative Example was measured as follows.
Measurement was performed using a TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry, TRIFT V nano TOF) equipped with an Ar-Bac Ar-GCIB gun. Bi3 ++ (30 kV) was used as the primary ion source. A 20 eV electron gun was used in combination for charge neutralization. Ar-GCIB (Ar2500 +, 15 kV) was used for the depth direction analysis. The maximum peak strength derived from silicone was determined, and the thicknesses of GLe, GLi, and porous support A were determined. The thickness values of the obtained GLe and GLi are shown in Table 8 below. Moreover, the ratio with respect to the thickness of thickness GLe of GLi was calculated | required in percentage, and the result was described in following Table 8.
Moreover, the content rate of the repeating unit represented by General formula (3) in surface layer (from the surface) 20nm in each area | region was calculated | required with respect to GLe and GLi defined in this way. Si2P spectra were obtained from analysis in the depth direction by ESCA (Electron Spectroscopy FOR Chemical Analysis) analysis. From the curve fitting of the Si2P spectral peak, the valence (Si2 ⁺ , Si3 ⁺ and Si4 ⁺ ) of the silicon atom was separated and quantified. The profile of Si ⁴⁺ , Si ³⁺ and Si ²⁺ with respect to the depth is measured, and the ratio of Si ⁴⁺ to the total Si component (total of Si ⁴⁺ , Si ³⁺ and Si ²⁺ ) is calculated as an integrated value from the surface layer to 20 nm, and GLe The content of the repeating unit represented by the general formula (3) of the surface layer 20 nm and the content of the repeating unit represented by the general formula (3) of the surface layer 20 nm of GLi. The average value in N = 5 measurement was adopted, and the results are shown in Table 8 below. Further, the difference between the content of the repeating unit represented by the general formula (3) of the surface layer 20 nm of GLe and the content of the repeating unit represented by the general formula (3) of the surface layer 20 nm of GLi was calculated, It described in Table 8.
In addition, the surface layer of GLe of the resin layer containing a compound having a siloxane bond, the surface of GLe is a repeating unit represented by the general formula (1), a repeating unit represented by the general formula (2), and It was confirmed that a compound having a siloxane bond having a repeating unit represented by the general formula (3) was included.
The depth of the resin layer containing a compound having a siloxane bond from the surface of the resin layer containing a compound having a siloxane bond in the direction of the support was calculated from the etching rate of 10 nm / min of the resin layer material containing the compound having a siloxane bond. This value can be obtained every time the material changes, and the optimum value for the material is used as appropriate.
The surface of the resin layer containing the aforementioned compound having a siloxane bond (GLe surface) can be similarly determined by measuring the O / Si ratio by ESCA. That is, the O / Si ratio is maximum when measured from the surface of the gas separation membrane opposite to the porous support A toward the porous support A, and the number of silicon atoms is 3% (Atomic). %) Or more is the surface of GLe.

[Examples 1002 to 1011 and Comparative Examples 1001 to 1004]
In Example 1001, 1002 to 1011 and Comparative Examples 1001 to 1004 in the same manner as in Example 1001 except that the production conditions of the resin layer precursor containing the compound having a siloxane bond were changed as shown in Table 8 below. A gas separation membrane was obtained.

[Evaluation]
<Evaluation of gas separation performance of gas separation membrane>
In each of the gas separation membranes of the Examples and Comparative Examples, which are the obtained thin-layer composite membranes, a SUS316 stainless steel cell (made by DENISSEN) having high pressure resistance was used, and the cell temperature was adjusted to 30 ° C. for evaluation. did. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 6:94 is adjusted so that the total pressure on the gas supply side is 5 MPa (CO ₂ partial pressure: 0.65 MPa), and CO 2 The gas permeability of each of ₂ and CH ₄ was measured by TCD detection type gas chromatography. The gas separation selectivity of the gas separation membrane of each Example and Comparative Example was calculated as the ratio of the CO ₂ permeability coefficient P _{CO2 to} the CH ₄ permeability coefficient P _CH4 of this membrane (P _CO2 / P _CH4 ). The CO ₂ permeability of the gas separation membrane of each Example and Comparative Example was defined as the CO ₂ permeability Q _CO2 (unit: GPU) of this membrane.
The unit of gas permeability is a GPU (GPU) unit [1 GPU = 1 × 10 ⁻⁶ cm ³ (STP) / cm ² ) representing a permeation flux (also referred to as permeability, permeability, and Permeance) per pressure difference. · Sec · cmHg] or a barrer unit (1 barrer = 1 × 10 ⁻¹⁰ cm ³ (STP) · cm / cm ² · sec · cmHg) representing a transmission coefficient. In this specification, the unit of GPU is represented by the symbol Q, and the unit of barrer is represented by the symbol P.
When the gas permeability (CO ₂ permeability Q _CO2 ) is 30 GPU or more and the gas separation selectivity is 40 or more, the evaluation is AA,
When the gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and less than 30 GPU and the gas separation selectivity is 30 or more and less than 40, the evaluation is A,
The gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and the gas separation selectivity is less than 30, or the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is 30 or more. If so, the evaluation is B,
When the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is less than 30, or the pressure is not applied (the pressure cannot be maintained) and the test cannot be performed. Was rated C.
The obtained results are shown in Table 8 below.

<Evaluation of bending resistance>
The gas separation membrane of each Example and Comparative Example was wound around a roll having a diameter of 20 mm, and was allowed to stand for 24 hours at 25 ° C. and a relative humidity of 20%. The gas permeation performance after being wound around a roll was evaluated by the method described above. Previous gas permeability wound into a roll; for (gas permeability of CO ₂ permeability _{Q CO2),} gas permeation performance after wound into a roll; ratio of (gas permeability permeability _{Q CO2} of CO ₂₎ (retention Rate). The obtained results were evaluated based on the following criteria. The bending resistance is preferably A or B evaluation, and more preferably A evaluation.
A: Retention rate is 80% or more.
B: Retention rate is less than 80% and 30% or more.
C: Retention rate is less than 30%.
The obtained results are shown in Table 8 below.

From Table 8 above, as compared with Comparative Examples 1001 to 1004, the gas separation membrane of the present invention has high gas permeability (CO ₂ permeability) and gas separation selectivity under high pressure and good bending resistance. It was found to be a gas separation membrane.

[Example 1012]
<Preparation of additional resin layer>
(Synthesis of polymer (P-101))
A polymer (P-101) was synthesized according to the following reaction scheme.

Synthesis of polymer (P-101):
N-methylpyrrolidone 123 ml, 6FDA (manufactured by Tokyo Chemical Industry Co., Ltd., product number: H0771) 54.97 g (0.124 mol) was added to a 1 L three-necked flask and dissolved at 40 ° C. and stirred under a nitrogen stream. 2,3,5,6-tetramethylphenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1457) 4.098 g (0.0248 mol), 3,5-diaminobenzoic acid 15.138 g (0.0992 mol) Of N-methylpyrrolidone in an amount of 84.0 ml was added dropwise over 30 minutes while maintaining the system at 40 ° C. After stirring the reaction solution at 40 ° C. for 2.5 hours, 2.94 g (0.037 mol) of pyridine (manufactured by Wako Pure Chemical Industries, Ltd.), 31.58 g (0.31 mol) of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) Each was added and further stirred at 80 ° C. for 3 hours. Thereafter, 676.6 mL of acetone was added to the reaction solution for dilution. The acetone dilution liquid of the reaction liquid was dripped at the place which added methanol 1.15L and acetone 230mL to the 5L stainless steel container and stirred. The obtained polymer crystals were suction filtered and blown dry at 60 ° C. to obtain 50.5 g of polymer (P-101). This polymer (P-101) is the same as the above-described exemplified polyimide compound P-100 with X: Y = 20: 80.

(Formation of additional resin layer)
In a 30 ml brown vial, 1.4 g of polymer (P-101) and 8.6 g of methyl ethyl ketone were mixed and stirred at 25 ° C. for 30 minutes. Thereafter, spin coating is performed in the same manner as in Example 1008 on a resin layer containing a compound having a siloxane bond, which is plasma-treated under the same conditions as in Example 1008, to form an additional resin layer having a thickness of 150 nm, thereby obtaining a gas separation membrane. It was.
The obtained separation membrane was used as the gas separation membrane of Example 1012.

[Example 1013]
An additional resin layer is formed in the same manner as in Example 1012 except that a resin layer containing a compound having a siloxane bond obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 1009 is used. A gas separation membrane of Example 1013 was obtained.

[Example 1014]
An additional resin layer is formed in the same manner as in Example 1012 except that a resin layer containing a compound having a siloxane bond obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 1010 is used. A gas separation membrane of Example 1014 was obtained.

For the gas separation membranes of Examples 1012 to 1014, the gas separation performance and the bending resistance were all evaluated as AA.

[Examples 1101 to 1114]
-modularization-
Using the gas separation membranes produced in Examples 1001 to 1014, spiral type modules were produced with reference to [0012] to [0017] of JP-A-5-168869. The obtained gas separation membrane module was used as the gas separation membrane module of Examples 1101 to 1114.
It was confirmed that the produced gas separation membrane modules of Examples 1101 to 1114 were good according to the performance of the built-in gas separation membrane.
The produced gas separation membrane modules of Examples 1101 to 1114 are leafs (the leaf is a spiral type module in which the permeate side space is connected to the central tube and is bent into an envelope shape) 10 points of 1 cm × 1 cm are sampled randomly from within 10 cm × 10 cm of the center of one side of the sample, and the element ratio in the surface and depth direction is calculated according to the method of Example 1001. It was confirmed that it was as per the separation membrane. Moreover, it was confirmed that the spiral module was good according to the performance of the built-in gas separation membrane.

{Third aspect}
The Example of the 3rd aspect which satisfy | fills the conditions 3 is shown.

[Example 2001]
<Preparation of polymerizable radiation-curable composition for forming a resin layer precursor containing a compound having a siloxane bond>
With respect to KF-102 (Shin-Etsu Chemical Co., Ltd., side chain type / alicyclic epoxy-modified reactive silicone oil) cooled to 20 ° C., it was diluted with n-heptane so that the solid content was 10% by mass. To the obtained solution, 0.5 g of IO591 (manufactured by Tokyo Chemical Industry Co., Ltd.) that is a photopolymerization initiator and 0.1 g of titanium isoporopoxide (manufactured by aldrich) are added, and a polymerizable radiation-curable composition is obtained. Prepared.

<Formation of resin layer precursor containing compound having siloxane bond>
PAN (Polyacrylonitrile) porous membrane (Polyacrylonitrile porous membrane is present on the nonwoven fabric, including the nonwoven fabric, the film thickness is about 180 μm) Supporting the polymerizable radiation curable composition at 3000 rpm, dropping amount of 0.03 ml After spin coating under the conditions of / cm ² , it was stored at room temperature for 1 min. Thereafter, the polymerizable radiation curable composition was subjected to UV treatment (Fusion UV System, Light Hammer 10, D-bulb) under UV treatment conditions of a UV intensity of 24 kW / m ² and a UV irradiation time of 10 seconds to form a siloxane bond. The resin layer precursor containing a compound having the following was cured. In this manner, a resin layer precursor containing a compound having a siloxane bond having a thickness of 120 nm and including a compound having a siloxane bond having a dialkylsiloxane group was formed on the porous support.

<Oxygen atom permeation treatment of a resin layer precursor containing a compound having a siloxane bond-plasma treatment->
Put porous support to form a resin layer precursor comprising a compound having a siloxane bond to the desktop vacuum plasma apparatus (UTEC Corporation), the oxygen flow rate 20 cm ³ of carrier gas conditions (STP) / min, argon flow rate 100 cm ³ ( STP) / min, the degree of vacuum was 30 Pa, the input power was 400 W, and the plasma treatment was performed for a treatment time of 7 seconds.
The obtained composite membrane was used as the gas separation membrane of Example 2001.

<Calculation of ratio of Si ²⁺ and Si ³⁺ peaks to all Si peaks when ESCA depth analysis is performed>
The sum of the Si ²⁺ peak and Si ³⁺ peak in the depth direction in the resin layer containing the compound having a siloxane bond, and the ratio of the total Si peak to the resin subjected to the etching treatment with C ₆₀ ions. It calculated using ESCA (Electron Spectroscopy FOR Chemical Analysis).
That is, Physical Electronics, Inc. At Company Ltd. QuanteraSXM comes _{C 60} ion gun, ion beam intensity _C ⁶⁰ +: 10 keV, and 10 nA, while advancing the etching an area of 2mm × 2mm at an etching rate 10 nm / min, using ESCA apparatus, a siloxane bond By measuring the Si2p spectrum on the surface of the resin layer containing the compound having, and separating and quantifying the valence of Si (Si ²⁺ , Si ³⁺ and Si ⁴⁺ ) from the curve fitting of the obtained peak, The profile of each peak intensity was measured.
Then, the ratio of the Si ²⁺ peak and the Si ³⁺ peak to the sum of the quantified total Si peaks (Si ²⁺ , Si ³⁺ and Si ⁴⁺ ) at each depth is calculated, and this is calculated in the depth direction of Si ²⁺ and Si ^3+. The minimum value (Si ₀ ) was derived from the profile. In the gas separation membranes of Examples 2001 to 2013, the surface of the outermost layer (on the side opposite to the support) of the resin layer containing the compound having a siloxane bond was ^compared with the Si ²⁺ and Si ³⁺ peaks of all Si peaks. It was a position having the minimum value (Si ₀ ).
The ratio of Si ²⁺ and Si ³⁺ to the total Si peak at a depth of 10 nm from the position having the minimum value (Si ₀ ) of the ratio of Si ²⁺ and Si ³⁺ to the total Si (Si ²⁺ + Si ³⁺ / all Si) The difference between the ratio (Si ₁₀ ) (Si ²⁺ + Si ³⁺ / all Si) and the minimum value (Si ₀ ) of the ratio of Si ²⁺ and Si ³⁺ to the total Si peak (Si ²⁺ + Si ³⁺ / all Si) ( Si ₁₀ ) − (Si ₀ ) was defined as Δ1.
Similarly ^{Si 2+} and, Si3 + ^{Si 2+} and definitive minimum value (Si ₀₎ depth of 20nm from a position having a ratio ^{^{(Si 2+ + Si 3+ / all}} Si) to total Si peak, the total Si peak ^{Si 3+} the ratio of the relative peak _{^{^{(Si 20) (Si 2+ +}}} Si 3+ / all Si), the minimum value of the ratio ^{^{(Si 2+ + Si 3+ / all}} Si) with respect to the peak of the total Si peak of ^{Si 2+} and ^{Si 3+} and (Si ₀₎ The difference (Si ₂₀ ) − (Si ₀ ) between these was Δ2.
For the calculation of Si ₀ , Si ₁₀ , and Si ₂₀ , an average value of 5 times of measurement (N number) at different measurement locations was adopted.
Furthermore, from the peaks of Si ²⁺ , Si ³⁺ and Si ⁴⁺ , the compound having a siloxane bond included in the resin layer containing a compound having a siloxane bond on the surface of the resin layer containing the compound having a siloxane bond is represented by the general formula (3). The ratio of the represented repeating unit to the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (1) is 3 to 500 mol% in Examples 2001 and 2004 to 2013, On the other hand, in Examples 2002 and 2003, it was confirmed by the same method that it was 5 to 400 mol%.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 500 mol% in Examples 2001 and 2004 to 2013, while 5 in Example 2002 and 2003. It was confirmed by the same method that it was ˜400 mol%.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 20 nm from the surface of the resin layer containing the compound having a siloxane bond The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 400 mol% in Examples 2001 and 2004 to 2013, while 5 in Example 2002 and 2003. It was confirmed by the same method that it was ˜300 mol%.

<Calculation of thickness of resin layer containing compound having siloxane bond>
The thickness of the resin layer containing the compound having a siloxane bond in the gas separation membrane of each Example and Comparative Example was measured as follows.
Measurement was performed using a TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry, TRIFT V nano TOF) equipped with an Ar-Bac Ar-GCIB gun. Bi3 ++ (30 kV) was used as the primary ion source. A 20 eV electron gun was used in combination for charge neutralization. Ar-GCIB (Ar2500 +, 15 kV) was used for the depth direction analysis.

[Examples 2002 to 2013 and Comparative Examples 2001 to 2003]
Examples 2002 to 2013 and Comparative Example were the same as Example 2001 except that the production conditions and plasma treatment conditions of the resin layer precursor containing a compound having a siloxane bond were changed as shown in the following table. Gas separation membranes of 2001 to 2003 were obtained.
In Examples 2002 and 2003, UV POLY201 (produced by Arakawa Chemical Industries, Ltd., cation curable UV silicone resin) was used as a compound having a siloxane bond instead of KF-102 (produced by Shin-Etsu Chemical Co., Ltd.).

[Evaluation]
<Evaluation of gas separation performance of gas separation membrane>
In each of the gas separation membranes of the Examples and Comparative Examples which are the obtained thin-layer composite membranes, a high-pressure-resistant SUS316 stainless steel cell (DENISSEN) was used, and the cell temperature was adjusted to 30 ° C. evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 6:94 is adjusted so that the total pressure on the gas supply side is 5 MPa (CO ₂ partial pressure: 0.65 MPa), and CO 2 The gas permeability of each of ₂ and CH ₄ was measured by TCD detection type gas chromatography. The gas separation selectivity of the gas separation membrane of each Example and Comparative Example was calculated as the ratio of the CO ₂ permeability coefficient P _{CO2 to} the CH ₄ permeability coefficient P _CH4 of this membrane (P _CO2 / P _CH4 ). The CO ₂ permeability of the gas separation membrane of each Example and Comparative Example was defined as the CO ₂ permeability Q _CO2 (unit: GPU) of this membrane.
The unit of gas permeability is a GPU (GPU) unit [1 GPU = 1 × 10 ⁻⁶ cm ³ (STP) / cm ² ) representing a permeation flux (also referred to as permeability, permeability, and Permeance) per pressure difference. · Sec · cmHg] or a barrer unit (1 barrer = 1 × 10 ⁻¹⁰ cm ³ (STP) · cm / cm ² · sec · cmHg) representing a transmission coefficient. In this specification, the unit of GPU is represented by the symbol Q, and the unit of barrer is represented by the symbol P.
When the gas permeability (CO ₂ permeability Q _CO2 ) is 30 GPU or more and the gas separation selectivity is 40 or more, the evaluation is AA,
When the gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and less than 30 GPU and the gas separation selectivity is 30 or more and less than 40, the evaluation is A,
The gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and the gas separation selectivity is less than 30, or the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is 30 or more. If so, the evaluation is B,
When the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is less than 30, or the pressure is not applied (the pressure cannot be maintained) and the test cannot be performed. Was rated C.
The obtained results are shown in Table 9 below.

<Evaluation of pressure resistance>
In the gas separation performance evaluation, after performing the pressure resistance test after the evaluation, the process of increasing the total pressure on the gas supply side to 8 MPa and holding it for 1 hour and reducing the pressure to 5 MPa and holding it for 1 hour is repeated three times. The gas permeation performance at a total pressure of 5 MPa on the gas supply side was evaluated by the method described above. Measured gas permeability prior to performing the pressure resistance test; for (gas permeability permeability Q _CO2 of CO _{_2),} gas permeability, measured after the pressure resistance test (gas permeable, CO ₂ of permeability Q The ratio (retention rate) of _CO2 ) was calculated. The obtained results were evaluated based on the following criteria. The bending resistance is preferably AA, A or B evaluation, more preferably AA or A evaluation, and particularly preferably AA evaluation.
AA: 80% or more.
A: 70% or more and less than 80%.
B: 30% or more and less than 70%.
C: Less than 30%.
The obtained results are shown in Table 9 below.

From Table 9 above, when the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond exceeds the upper limit defined in the present invention Compared to (Comparative Examples 2001 and 2002), it is found that the gas separation membrane of the present invention has high gas permeability (CO ₂ permeability) and gas separation selectivity under high pressure and excellent pressure resistance. It was.
Further, when the minimum value Si _{0 of the} ratio of the Si ²⁺ and Si ³⁺ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing the compound having a siloxane bond is lower than the lower limit defined in the present invention (Comparative Example) Compared to 2003), the gas separation membrane of the present invention did not change much in pressure resistance, but it was found that at least one of gas permeability (CO ₂ permeability) and gas separation selectivity under high pressure was high.

[Example 2014]
<Preparation of additional resin layer>
(Synthesis of polymer (P-101))
A polymer (P-101) was synthesized according to the following reaction scheme.

(Formation of additional resin layer)
In a 30 ml brown vial, 1.4 g of polymer (P-101) and 8.6 g of methyl ethyl ketone were mixed and stirred at 25 ° C. for 30 minutes. Thereafter, spin coating is performed in the same manner as in Example 2012 on a resin layer containing a compound having a siloxane bond, which is plasma-treated under the same conditions as in Example 2012, to form an additional resin layer having a thickness of 120 nm, thereby obtaining a gas separation membrane. It was.
The obtained separation membrane was used as the gas separation membrane of Example 2014.

[Example 2015]
An additional resin layer was formed in the same manner as in Example 2014, except that a resin layer containing a compound having a siloxane bond, which was obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 2013, was used. A gas separation membrane of Example 2015 was obtained.

For the gas separation membranes of Examples 2014 to 2015, all the gas separation performance and pressure resistance evaluation described above were AA evaluations.

[Examples 2101 to 2115]
-modularization-
Using the gas separation membranes produced in Examples 2001 to 2015, spiral type modules were produced with reference to [0012] to [0017] of JP-A-5-168869. The obtained gas separation membrane module was used as the gas separation membrane module of Examples 2101 to 2115.
It was confirmed that the produced gas separation membrane modules of Examples 2101 to 2115 were good according to the performance of the built-in gas separation membrane.
The produced gas separation membrane modules of Examples 2101 to 2115 are the leaves (the leaf is a portion of the gas separation membrane folded in an envelope shape in which the space on the transmission side is connected to the central tube in the spiral type module). 10 points of 1 cm × 1 cm are sampled randomly from within 10 cm × 10 cm of the center of one side of the sample, and the element ratio in the surface and depth direction is calculated according to the method of Example 2001. It was confirmed that it was as per the separation membrane. Moreover, it was confirmed that the spiral module was good according to the performance of the built-in gas separation membrane.

{Fourth aspect}
The Example of the 4th aspect which satisfy | fills the conditions 4 is shown.

[Example 3001]
<Preparation of polymerizable radiation-curable composition for forming a resin layer precursor containing a compound having a siloxane bond>
(Preparation of radiation curable polymer having dialkylsiloxane group)
In a 150 ml three-necked flask, 39 g of UV9300 (manufactured by Momentive), 10 g of X-22-162C (manufactured by Shin-Etsu Chemical Co., Ltd.), DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) 0.007 g was added and dissolved in 50 g of n-heptane.
This was maintained at 95 ° C. for 168 hours to obtain a radiation curable polymer solution having a poly (siloxane) group (viscosity of 22.8 mPa · s at 25 ° C.).

<Formation of resin layer precursor containing compound having siloxane bond>
PAN (polyacrylonitrile) porous membrane (polyacrylonitrile porous membrane is present on the nonwoven fabric, including the nonwoven fabric, the thickness is about 180 μm) and spin-coated with a polymerizable radiation curable composition, followed by UV intensity 24 kW UV treatment (Fusion UV System, Light Hammer 10, D-bulb) was performed under UV treatment conditions of / m ² and UV irradiation time of 10 seconds, and then dried. In this way, a resin layer precursor containing a compound having a siloxane bond having a dialkylsiloxane group and having a siloxane bond having a thickness of 1 μm was formed on the porous support.

<Oxygen atom permeation treatment of a resin layer precursor containing a compound having a siloxane bond-plasma treatment->
Put porous support to form a resin layer precursor comprising a compound having a siloxane bond to the desktop vacuum plasma apparatus (UTEC Corporation), the oxygen flow rate 50 cm ³ of carrier gas conditions (STP) / min, argon flow rate 100 cm ³ ( STP) / min, the degree of vacuum was 30 Pa, the input power was 25 W, and the plasma treatment was performed for a treatment time of 20 seconds. As the plasma processing conditions common to each example and comparative example, anode coupling was used, the processing time was 20 seconds, and the oxygen flow rate was 50 cm ³ (STP) / min.
The obtained composite membrane was used as the gas separation membrane of Example 3001.

(Calculation of valence of silicon atom of resin layer containing compound having siloxane bond)
Resin containing a valence of silicon atoms contained in a resin layer containing a compound having a siloxane bond at a depth of 10 nm and 100 nm from the surface of the resin layer containing a compound having a siloxane bond toward the support, and a compound having a siloxane bond The valence of silicon atoms on the surface of the layer was calculated using ESCA (Electron Spectroscopy FOR Chemical Analysis).
A porous support formed with a resin layer containing a compound having a siloxane bond was obtained from Physical Electronics, Inc. Included in Quantera SXM manufactured by the company, X-ray source: Al—Kα ray (1490 eV, 25 W, diameter of 100 μm), measurement area: 300 μm × 300 μm, Pass Energy 55 eV, Step 0.05 eV, including a compound having a siloxane bond A spectrum on the surface of the resin layer was obtained. Etching with C60 ions was also performed. Specifically, Physical Electronics, Inc. With a Quantera SXM attached C60 ion gun, the ion beam intensity was C60 +: 10 keV, 10 nA, and a 2 mm × 2 mm region was etched by 10 nm and 100 nm. Using this ESCA apparatus, the Si2P spectrum at a depth of 10 nm and 100 nm from the surface of the resin layer containing a compound having a siloxane bond to the support and the Si2P surface of the resin layer containing a compound having a siloxane bond are used. A spectrum was obtained. From the curve fitting of the Si2P spectral peak, the valence (Si2 ⁺ , Si3 ⁺ and Si4 ⁺ ) of the silicon atom was separated and quantified. As described above, the surface of the resin layer containing a compound having a siloxane bond and the resin layer containing a compound having a siloxane bond at a depth of 10 nm and 100 nm from the surface of the resin layer containing the compound having a siloxane bond to the support, It is confirmed that the compound contains a compound having a repeating unit represented by the general formula (1) and a siloxane bond having at least the repeating unit represented by the general formula (2) or the repeating unit represented by the general formula (3). It was done.
The depth of the resin layer containing a compound having a siloxane bond from the surface of the resin layer containing a compound having a siloxane bond in the direction of the support was calculated from the etching rate of 10 nm / min of the resin layer material containing the compound having a siloxane bond. This value can be obtained every time the material changes, and the optimum value for the material is used as appropriate.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 500 mol% in Examples 3001 to 3007, while 5 to 400 in Examples 3008 to 3009. It was confirmed by the same method that it was mol%.
The repeating unit represented by the general formula (3) in the compound having a siloxane bond contained in the resin layer containing a compound having a siloxane bond at a depth of 100 nm from the surface of the resin layer containing the compound having a siloxane bond The ratio of the repeating unit represented by the formula (2) and the repeating unit represented by the general formula (1) is 3 to 400 mol% in Examples 3001 to 3007, while 5 to 300 in Examples 3008 to 3009. It was confirmed by the same method that it was mol%.
Similarly, the surface of the resin layer containing the compound having a siloxane bond can be determined by measuring the O / Si ratio by ESCA. That is, the O / Si ratio is maximum and the number of silicon atoms is 3% (Atomic%) when measured in the direction of the support from the surface opposite to the support of the gas separation membrane. The surface included above is defined as the surface.

(Measurement of the positron lifetime of the third component and the relative intensity of the third component)
A 1.5 cm × 1.5 cm square test piece was cut out from the gas separation membrane of Example 3001, attached to a commercially available Si wafer, vacuum degassed at room temperature (25 ° C.), and then subjected to positron annihilation lifetime under the following conditions. Was measured. Under the following conditions, the positron lifetime of the third component and the relative intensity of the third component are uniquely determined.

The obtained data was analyzed for the third component based on the nonlinear least square program POSITRONFIT, and the positron lifetime τ3 (ns) of the third component and the relative intensity I3 of the third component were calculated for the beam intensities of 1 keV and 3 keV, respectively. (P. Kirkegaard, M. Eldrup, OE Mogensen, N. J. Pedersen, Computer Physics Communications, 23, 307 (1981)). The results obtained are listed in the table below.
If the resin layer containing a compound having a siloxane bond is not the outermost layer and another layer such as an additional resin layer is outside the resin layer containing a compound having a siloxane bond, the siloxane bond is etched using ESCA. The conditions for projecting the surface of the resin layer containing the compound having the above are calculated, and the sample etched under the same conditions is used for measurement of the positron lifetime of the third component and the relative intensity of the third component.

[Examples 3002 to 3007]
In Example 3001, the input power of the plasma treatment of the resin layer precursor containing a compound having a siloxane bond was changed from 25 W as shown in the following table, respectively. A gas separation membrane was obtained.

[Examples 3008 and 3009]
Example 3007 is the same as Example 3007 except that the resin layer precursor material containing a compound having a siloxane bond is changed from PDMS to Polydiphenyl siloxane and Poly [methyl (3,3,3-trifluoropropyl) siloxane], respectively. Thus, gas separation membranes of Examples 3008 and 3009 were obtained.
Polyphenyl siloxane is available under the trade name 482153 manufactured by Sigma Aldrich, and Poly [methyl (3,3-trifluoropropyl) siloxane] (abbreviated as PMTFPS) is available under the trade name 48 available from Sigma Aldrich 45. Use.

[Example 3010]
In Example 3004, after oxygen atom permeation treatment, a polymerizable radiation curable composition was further spin-coated on a resin layer containing a compound having a siloxane bond, and the UV intensity was 24 kW / m ² and the treatment time was 10 UV treatment (Fusion UV System, Light Hammer 10, D-bulb) was performed under UV treatment conditions for 2 seconds, and then dried. In this way, a resin layer precursor containing a compound having a siloxane bond as a second layer having a thickness of 1 μm was formed.
A porous support formed with a resin layer precursor containing a compound having a siloxane bond in the second layer is placed in a desktop vacuum plasma apparatus (manufactured by YOUTEC), and the carrier gas conditions are oxygen flow rate 50 cm ³ (STP) / min, argon The plasma treatment, which is the second oxygen atom infiltration treatment, was performed at a flow rate of 100 cm ³ (STP) / min, a degree of vacuum of 30 Pa, an input power of 100 W, and a treatment time of 20 seconds.
The obtained gas separation membrane was used as the gas separation membrane of Example 3010.

[Example 3011]
In Example 3010, after the second oxygen atom permeation treatment was performed on the resin layer precursor containing a compound having a siloxane bond in the second layer, the resin layer containing a compound having a siloxane bond in the second layer was applied. Further, a polymerizable radiation-curable composition was spin-coated, and UV treatment (Fusion UV System, Light Hammer 10, D-bulb) was performed under a UV treatment condition of a UV intensity of 24 kW / m ² and a treatment time of 10 seconds. And then dried. In this way, a resin layer precursor containing a compound having a siloxane bond as a third layer having a thickness of 1 μm was formed.
Put porous support to form a resin layer containing a compound precursor having a siloxane bond the third layer to the desktop vacuum plasma apparatus (YOUTEC Corp.), the oxygen flow rate 50 cm ³ of carrier gas conditions (STP) / min, argon The flow rate was 100 cm ³ (STP) / min, the degree of vacuum was 30 Pa, the input power was 100 W, and the plasma treatment, which is the third oxygen atom infiltration treatment, was performed in a treatment time of 20 seconds.
The obtained gas separation membrane was used as the gas separation membrane of Example 3011.

[Comparative Example 3001]
In Example 3001, a gas separation membrane of Comparative Example 3001 was obtained in the same manner as in Example 3001, except that the input power for plasma treatment of the resin layer precursor containing a compound having a siloxane bond was changed from 25 W to 10 W.

[Comparative Example 3002]
A gas separation membrane of Comparative Example 3002 was obtained in the same manner as in Example 3001, except that the carrier gas condition was changed from 50 cm ³ (STP) / min to 0 cm ³ (STP) / min in Example 3001.

[Comparative Example 3003]
Based on the technique described in Journal of Membrane Science 99 (1995) 139-147, a polydimethylsiloxane film was treated with 5 W for 120 seconds under an Ar atmosphere to produce a composite film. The obtained composite membrane was used as a gas separation membrane of Comparative Example 3003 and evaluated in the same manner as in Example 3001. Using a stainless steel cell made of SUS316 (manufactured by DENISSEN) having high-pressure resistance, the cell temperature was adjusted to 40 ° C., and the gas separation performance was evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 13:87 is adjusted so that the total pressure on the gas supply side is 6 MPa (CO ₂ partial pressure: 0.78 MPa), and CO 2 _{When an} attempt was made to measure the gas permeability of each of ₂ and CH ₄ by TCD detection type gas chromatography, the pressure could not be maintained.

[Comparative Example 3004]
Based on the method described in Journal of Membrane Science 440 (2013) 1-8, the polydimethylsiloxane film was subjected to atmospheric pressure plasma treatment to produce a composite film. The obtained composite membrane was used as a gas separation membrane of Comparative Example 3004 and evaluated in the same manner as in Example 3001. Using a stainless steel cell made of SUS316 (manufactured by DENISSEN) having high-pressure resistance, the cell temperature was adjusted to 40 ° C., and the gas separation performance was evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 13:87 is adjusted so that the total pressure on the gas supply side is 6 MPa (CO ₂ partial pressure: 0.78 MPa), and CO 2 _{When an} attempt was made to measure the gas permeability of each of ₂ and CH ₄ by TCD detection type gas chromatography, the pressure could not be maintained.

[Comparative Example 3005]
PAN (Polyacrylonitrile) porous membrane (Polyacrylonitrile porous membrane exists on the nonwoven fabric, including the nonwoven fabric, thickness is about 180 μm) Using plasma CVD (hexamethyldisiloxane, 500 W, YOUTUCH solution vaporization CVD device) A silica film was deposited to 30 nm. The obtained composite membrane was used as a gas separation membrane of Comparative Example 3005 and evaluated in the same manner as in Example 3001.

[Example 3012]
<Preparation of additional resin layer>
(Synthesis of polymer (P-101))
A polymer (P-101) was synthesized according to the following reaction scheme.

Synthesis of polymer (P-101):
N-methylpyrrolidone 123 ml, 6FDA (manufactured by Tokyo Chemical Industry Co., Ltd., product number: H0771) 54.97 g (0.124 mol) was added to a 1 L three-necked flask and dissolved at 40 ° C. and stirred under a nitrogen stream. 2,3,5,6-tetramethylphenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1457) 4.098 g (0.0248 mol), 3,5-diaminobenzoic acid 15.138 g (0.0992 mol) Of N-methylpyrrolidone in an amount of 84.0 ml was added dropwise over 30 minutes while maintaining the system at 40 ° C. After stirring the reaction solution at 40 ° C. for 2.5 hours, 2.94 g (0.037 mol) of pyridine (manufactured by Wako Pure Chemical Industries, Ltd.), 31.58 g (0.31 mol) of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) Each was added and further stirred at 80 ° C. for 3 hours. Thereafter, 676.6 mL of acetone was added to the reaction solution for dilution. The acetone dilution liquid of the reaction liquid was dripped at the place which added methanol 1.15L and acetone 230mL to the 5L stainless steel container and stirred. The obtained polymer crystals were suction filtered and blown dry at 60 ° C. to obtain 50.5 g of polymer (P-101). This polymer (P-101) is the same as the above-described exemplified polyimide compound P-100 with X: Y = 20: 80. In the table below, polymer (P-101) is abbreviated as PI.

(Formation of additional resin layer)
In a 30 ml brown vial, 1.4 g of polymer (P-101) and 8.6 g of methyl ethyl ketone were mixed and stirred at 25 ° C. for 30 minutes. Thereafter, the stirred solution was spin-coated on the plasma-treated surface of the resin layer containing a compound having a siloxane bond in the same manner as in Example 3005 to form an additional resin layer having a thickness of 150 nm, thereby obtaining a gas separation membrane.
The obtained separation membrane was used as the gas separation membrane of Example 3012.

[Example 3013]
An additional resin layer is formed in the same manner as in Example 3012 except that a resin layer containing a compound having a siloxane bond, which is obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 3006, is used. A gas separation membrane of Example 3013 was obtained.

[Example 3014]
An additional resin layer is formed in the same manner as in Example 3012 except that a resin layer containing a compound having a siloxane bond, which is obtained by subjecting a resin layer containing a compound having a siloxane bond to plasma treatment under the same conditions as in Example 3007, is used. A gas separation membrane of Example 3014 was obtained.

[Examples 3015 to 3017]
A gas separation membrane was obtained in the same manner as in Example 3005 except that the thickness of the resin layer containing a compound having a siloxane bond was changed as described in the following table, except that plasma treatment was performed under the same conditions as in Example 3005. . The obtained gas separation membrane was used as the gas separation membrane of Examples 3015 to 3017.

[Evaluation]
<Evaluation of gas separation performance of gas separation membrane>
In each of the gas separation membranes of the Examples and Comparative Examples, which are the obtained thin-layer composite membranes, a high-pressure-resistant SUS316 stainless cell (manufactured by DENISSEN) was used, and the cell temperature was adjusted to 40 ° C. evaluated. A mixed gas having a volume ratio of carbon dioxide (CO ₂ ) and methane (CH ₄ ) of 13:87 is adjusted so that the total pressure on the gas supply side is 6 MPa (CO ₂ partial pressure: 0.78 MPa), and CO 2 The gas permeability of each of ₂ and CH ₄ was measured by TCD detection type gas chromatography. The gas separation selectivity of the gas separation membrane of each Example and Comparative Example was calculated as the ratio of the CO ₂ permeability coefficient P _{CO2 to} the CH ₄ permeability coefficient P _CH4 of this membrane (P _CO2 / P _CH4 ). The CO ₂ permeability of the gas separation membrane of each Example and Comparative Example was defined as the CO ₂ permeability Q _CO2 (unit: GPU) of this membrane.
The unit of gas permeability is a GPU (GPU) unit [1 GPU = 1 × 10 ⁻⁶ cm ³ (STP) / cm ² ) representing a permeation flux (also referred to as permeability, permeability, and Permeance) per pressure difference. · Sec · cmHg] or a barrer unit (1 barrer = 1 × 10 ⁻¹⁰ cm ³ (STP) · cm / cm ² · sec · cmHg) representing a transmission coefficient. In this specification, the unit of GPU is represented by the symbol Q, and the unit of barrer is represented by the symbol P.
When the gas permeability (CO ₂ permeability Q _CO2 ) is 30 GPU or more and the gas separation selectivity is 50 or more, the evaluation is AA,
When the gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and less than 30 GPU and the gas separation selectivity is 30 or more and less than 50, the evaluation is A,
The gas permeability (CO ₂ permeability Q _CO2 ) is 10 GPU or more and the gas separation selectivity is less than 30, or the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is 30 or more. If so, the evaluation is B,
When the gas permeability (CO ₂ permeability Q _CO2 ) is less than 10 GPU and the gas separation selectivity is less than 30, or the pressure is not applied (the pressure cannot be maintained) and the test cannot be performed. Was rated C.

From Table 11 and Table 12 above, the comparative example in which the positron lifetime τ3 of the third component when the positron is injected with the intensity of 1 keV from the surface of the resin layer containing the compound having a siloxane bond is outside the range defined in the present invention. Compared with gas separation membranes of 3001 to 3005, it was found that the gas separation membrane of the present invention has higher gas permeability (CO ₂ permeability) and gas separation selectivity under high pressure.

[Examples 3101 to 3117]
-modularization-
Using the gas separation membranes produced in Examples 3001 to 3017, spiral type modules were produced with reference to [0012] to [0017] of JP-A-5-168869. The obtained gas separation membrane module was used as the gas separation membrane module of Examples 3101 to 3117.
It was confirmed that the manufactured gas separation membrane modules of Examples 3101 to 3117 were good according to the performance of the built-in gas separation membrane.
The produced gas separation membrane modules of Examples 3101 to 3117 are leaves (the leaf is a portion of the gas separation membrane folded in an envelope shape in which the space on the transmission side is connected to the central tube in the spiral type module). 10 points of 1 cm × 1 cm are sampled randomly from within 10 cm × 10 cm of the center of one side, and the element ratio in the surface and depth direction is calculated according to the method of Example 3001. It was confirmed that it was as per the separation membrane. Moreover, it was confirmed that the spiral module was good according to the performance of the built-in gas separation membrane.

DESCRIPTION OF SYMBOLS 1 Additional resin layer 2 Resin layer precursor containing the compound which has siloxane bond 3 Resin layer 4 which contains the compound which has siloxane bond 4 Support body (in the 2nd aspect, porous support body A)
5 Oxygen atom permeation treatment 6 Surface of resin layer containing compound having siloxane bond 7 Depth from surface of resin layer containing compound having siloxane bond (in the direction of support (porous support A in the second embodiment)) Surface 10 of resin layer containing compound having siloxane bond in d Gas separation membrane 11 Polydimethylsiloxane membrane 12 not subjected to oxygen atom permeation treatment step Polydimethylsiloxane membrane d in which oxygen atoms are uniformly introduced in the film thickness direction Depth from the surface of the resin layer containing the compound having a siloxane bond (in the direction of the support (porous support A in the second embodiment))

Claims

A gas separation membrane satisfying any one of the following conditions 1, 3 and 4;
Condition 1: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which the resin layer containing the compound having a siloxane bond satisfies the following formula 1 and the following formula 2;
Formula 1 0.9 ≧ A / B ≧ 0.55
Formula 2 B ≧ 1.7
In Formula 1 and Formula 2, A is the number of oxygen atoms contained in the resin layer containing the compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. Represents an O / Si ratio that is a ratio, and B represents an O / Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond;
Condition 3: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane having a minimum value Si0 of 1 to 40% of the ratio of the Si 2+ and Si 3+ peaks to the total Si peaks in the ESCA depth analysis of the resin layer containing a compound having a siloxane bond;
Condition 4: a gas separation membrane having a resin layer containing a compound having a siloxane bond,
A gas separation membrane in which a positron lifetime τ3 of a third component is 3.40 to 4.20 ns when positrons are injected from the surface of the resin layer containing a compound having a siloxane bond with an intensity of 1 keV.
The gas separation membrane according to claim 1, wherein the condition 1 is satisfied.
The gas separation membrane according to claim 2, wherein the compound having a siloxane bond has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3);

In General Formula (2) and General Formula (3), R 11 represents a substituent, * represents a bonding site with # in General Formula (2) or General Formula (3), and # represents General Formula (2 ) Or a binding site with * in the general formula (3).
The gas separation membrane according to claim 2 or 3, wherein the compound having a siloxane bond has a repeating unit represented by the following general formula (1);
General formula (1)

In general formula (1), each R independently represents a hydrogen atom, an alkyl group having 1 or more carbon atoms, an aryl group, an amino group, an epoxy group, a fluorinated alkyl group, a vinyl group, an alkoxy group or a carboxyl group, and n is Represents an integer of 2 or more.
The surface of the resin layer containing the compound having a siloxane bond is a repeating unit represented by the general formula (1) and at least a repeating unit represented by the general formula (2) or the general formula (3). The gas separation membrane of Claim 4 containing the compound which has a siloxane bond which has a repeating unit represented.
The gas separation membrane according to any one of claims 2 to 5, wherein the ratio of the number of carbon atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond is 1.6 or less.
The gas separation membrane according to any one of claims 2 to 6, wherein B is 1.95 or more;
B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
The gas separation membrane according to any one of claims 2 to 7, wherein A / B is 0.6 or more;
A is an O / Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms in the resin layer containing the compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
The gas separation membrane according to any one of claims 2 to 8, wherein A / B is 0.65 or more;
A is an O / Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms in the resin layer containing the compound having a siloxane bond at a depth of 10 nm from the surface of the resin layer containing the compound having a siloxane bond. B represents an O / Si ratio which is a ratio of the number of oxygen atoms to the number of silicon atoms on the surface of the resin layer containing the compound having a siloxane bond.
The gas separation membrane according to any one of claims 2 to 9, further comprising a layer containing a polyimide compound.
The gas separation membrane according to any one of claims 2 to 10, wherein the layer containing the polyimide compound has a thickness of 0.03 to 0.3 μm.
The gas separation membrane according to any one of claims 2 to 11, wherein the resin layer containing the compound having a siloxane bond has a thickness of 0.1 to 5 µm.
The gas separation membrane according to any one of claims 2 to 12, wherein the resin layer containing a compound having a siloxane bond contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
The gas separation membrane according to any one of claims 2 to 13, further comprising a support.
The gas separation membrane according to any one of claims 2 to 14, wherein a gel fraction of the gas separation membrane is 45% or more.
Furthermore, it has a porous support A,
The gas separation membrane according to claim 1, which satisfies the following condition 2:
Condition 2: porous support A,
A gas separation membrane having a resin layer containing a compound having a siloxane bond located on the porous support A,
The compound having a siloxane bond has at least a repeating unit represented by the following general formula (2) or a repeating unit represented by the following general formula (3),
The resin layer containing the compound having a siloxane bond includes a region GLi existing in the porous support B and a region GLe existing on the porous support B,
The GLe has a thickness of 50 to 1000 nm;
The thickness of the GLi is 20 nm or more, and 10 to 350% of the thickness of the GLe;
The difference between the content of the repeating unit represented by the general formula (3) in the GLe surface layer 20 nm and the content of the repeating unit represented by the general formula (3) in the GLi surface layer 20 nm is 30 to 30%. 90% gas separation membrane;

In the general formula (2) and the general formula (3), R 11 represents a substituent, * represents a binding site with # in the general formula (2) or the general formula (3), and # is It represents a binding site with * in the general formula (2) or the general formula (3).
The gas separation membrane according to claim 16, wherein the thickness of the GLe is 200 to 900 nm.
The gas separation membrane according to claim 16 or 17, wherein the thickness of the GLi is 20 to 90% of the thickness of the GLe.
The gas separation membrane according to claim 1, wherein the condition 3 is satisfied.
The Si 2+ and Si Si definitive from the position at a depth of 10nm with a minimum value Si 0 percentage relative to the peak of the total Si peak 3+ 2+ and Si 3+ in ESCA depth analysis of the resin layer containing a compound having a siloxane bond The gas separation according to claim 19, wherein the difference Δ1 between the ratio Si 10 of the peak of Si to the total Si and the minimum value Si 0 of the ratio of the Si 2+ and Si 3+ peaks to the total Si peak is 50 to 90%. film.
The Si 2+ and Si Si definitive from the position at a depth of 20nm with a minimum value Si 0 percentage relative to the peak of the total Si peak 3+ 2+ and Si 3+ in ESCA depth analysis of the resin layer containing a compound having a siloxane bond The difference Δ2 between the ratio Si 20 of the peak of Si to the total Si and the minimum value Si 0 of the ratio of the Si 2+ and Si 3+ peaks to the total Si peak is 55 to 90%. Gas separation membrane.
The gas separation membrane according to any one of claims 19 to 21, wherein the resin layer containing the compound having a siloxane bond has a thickness of 150 to 900 nm.
The gas separation membrane according to any one of claims 19 to 22, further comprising a support.
The gas separation membrane according to claim 1, wherein the condition 4 is satisfied.
25. The gas separation membrane according to claim 24, wherein the relative intensity I3 of the third component when the positron is injected with the intensity of 1 keV from the surface of the resin layer containing the compound having a siloxane bond is 13 to 41%.
The positron lifetime τ3 of the third component when a positron is injected at a strength of 1 keV from the surface of the resin layer containing the compound having a siloxane bond is X, and the positron is 3 keV from the surface of the resin layer containing the compound having a siloxane bond. When the positron lifetime τ3 of the third component is Y,
0.88 ≦ X / Y ≦ 0.99
The gas separation membrane according to claim 24 or 25, wherein:
The gas separation membrane according to any one of claims 24 to 26, further comprising a layer containing a polyimide compound.
The gas separation membrane according to claim 27, wherein the layer containing the polyimide compound has a thickness of 0.03 to 0.3 μm.
The gas separation membrane according to any one of claims 24 to 28, wherein the resin layer containing the compound having a siloxane bond has a thickness of 0.1 to 5 µm.
The gas separation membrane according to any one of claims 24 to 29, wherein the resin layer containing a compound having a siloxane bond contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
The gas separation membrane according to any one of claims 24 to 30, further comprising a support.
A gas separation membrane module having the gas separation membrane according to any one of claims 1 to 31.
A gas separation apparatus comprising the gas separation membrane module according to claim 32.
A method for producing a gas separation membrane satisfying the following condition P1 or the following condition P4;
Condition P1: including an oxygen atom permeation treatment step of permeating oxygen atoms into a resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 10 cm 3 (STP) / min or more and an input power of 23 W or more;
Condition P4: including an oxygen atom infiltration treatment step for infiltrating oxygen atoms into the resin layer precursor containing a compound having a siloxane bond,
A method for producing a gas separation membrane, wherein the oxygen atom permeation treatment step is a plasma treatment using a carrier gas having an oxygen flow rate of 45 cm 3 (STP) / min or more, and using anode coupling at an input power of 23 W or more.
The method for producing a gas separation membrane according to claim 34, wherein the condition P1 is satisfied.
36. The method for producing a gas separation membrane according to claim 35, wherein the resin layer containing a compound having a siloxane bond contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
The method for producing a gas separation membrane according to claim 35 or 36, wherein a resin layer containing the compound having a siloxane bond is formed on a support.
A gas separation membrane produced by the method for producing a gas separation membrane according to any one of claims 35 to 37.
The method for manufacturing a gas separation membrane according to claim 34, wherein the condition P4 is satisfied.
40. The method for producing a gas separation membrane according to claim 39, wherein the resin layer containing a compound having a siloxane bond contains a compound having a repeating unit containing at least a silicon atom, an oxygen atom and a carbon atom.
The method for producing a gas separation membrane according to claim 39 or 40, wherein the resin layer containing the compound having a siloxane bond is formed on a support.