JP6029332B2 - Gas separation membrane - Google Patents

Description

  The present invention relates to a gas separation membrane having both a high gas permeability coefficient and high separability. More specifically, the gas separation membrane of the present invention is particularly excellent in carbon dioxide permeability coefficient. Therefore, the gas separation membrane of the present invention is used as a gas separation membrane for separating carbon dioxide from a carbon dioxide-containing mixed gas composed of carbon dioxide and nitrogen and / or air, or as a landfill gas (from wastes buried in the ground). It can be used as a gas separation membrane for separating carbon dioxide contained in the generated organic gas).

Conventionally, as gas separation membranes, those made of various polymers such as silicone (organopolysiloxane), polyimide, and polymer (PEO) composed of ethylene oxide units are known.
Silicone has a gas permeability coefficient of carbon dioxide of 1,000 Barrer (1 Barrer = 1 * 10 ⁻¹⁰ [cm ³ (STP) cm / cm ² / s / cmHg]) or more, but oxygen, nitrogen The selectivity obtained as the transmission coefficient ratio is 10 or less (Non-Patent Document 1).
Therefore, silicone is applied to a gas separation membrane as a filling agent for filling defects generated in the gas separation layer when forming the gas separation composite membrane by utilizing its high permeability coefficient (Patent Document 1).

  On the other hand, it is known that polyimide generally exhibits a high value of 20 to 40 in terms of carbon dioxide / nitrogen selectivity (Patent Documents 2 and 3). This is because, since polyimide has a rigid molecular structure, gas permeates through the film while exhibiting a diffusion behavior depending on the size of the molecule. However, most of these carbon dioxide permeability coefficients are 0.1 to 10 Barrer (Non-patent Documents 1 and 2), which is less than 1 / 100th that of silicone. That is, in order to obtain a transmission coefficient equivalent to that of silicone, it cannot be obtained unless it is applied to 1/100 or less of the thickness of the silicone.

  Since ethylene oxide units have a high affinity for carbon dioxide, it is known that PEO exhibits 50 or more carbon dioxide / nitrogen selectivity (Non-patent Documents 3 and 4). However, the carbon dioxide permeability coefficient of these polymers remains around 100 Barrer. JP 7-060079 (Patent Document 4) describes a plasma-treated film having a hydrophilic surface with PEO preferably having 2 to 30 repeating units. Although the gas permeability coefficient of the polymer material having PEO is shown, the carbon dioxide permeability coefficient and carbon dioxide / nitrogen selectivity are not sufficient.

Japanese Patent Laid-Open No. 11-9974 JP-A-60-150806 JP-A-8-332362 Japanese Unexamined Patent Publication No. 7-060079

Journal of Membrane Science 1994, 94, 1-65 Journal of Membrane Science 1993, 83, 1-80 Chemical Engineering Science 2009, 64, 4707-4718 Journal of Membrane Science 2009, 327, 195-207

  An object of the present invention is to provide a gas separation membrane that simultaneously satisfies a high carbon dioxide permeability coefficient and a high carbon dioxide / nitrogen selectivity.

（式中、Ｒ₁およびＲ₂は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁は２価の有機基であり、ｍは１〜１００の整数であり、ｎは５〜２０００の整数である。）
即ち、本発明は下記の発明を提供する。 The present inventor has intensively studied to achieve the above object, and as a result, a gas separation membrane composed of a crosslinked polymer having a structure represented by the following general formula (1) in which organopolysiloxane and polyethylene oxide are bonded via a siloxane bond. Has found that the above-mentioned problems can be solved, and has completed the present invention.

Wherein R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and m is an integer of 1 to 100 And n is an integer of 5 to 2000.)
That is, the present invention provides the following inventions.

｛式中、Ｒ ₁ およびＲ ₂ は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ ₁ は２価の有機基であり、ｍは１〜１００の整数であり、そしてｎは５〜２０００の整数である。｝で表される構造を有することを特徴とする気体分離膜。
［２］前記架橋ポリマーが下記式（２）：

｛式中、Ｒ₁およびＲ₂は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁およびＹ₂は２価の有機基であり、ｍは１〜１００の整数であり、そしてｎは５〜２０００の整数である。｝で表される構造または下記式（３）：

｛式中、Ｒ₁およびＲ₂は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁は２価の有機基であり、Ｙ₃は１価の有機基であり、ｍは１〜１００の整数であり、そしてｎは５〜２０００の整数である。｝で表される構造を有する、前記［１］に記載の気体分離膜。
［３］前記式（１）〜式（３）中のＹ₁およびＹ₂がアミノ基、ウレア基、ウレタン基およびチオエーテル基から選ばれた少なくとも１種の基である、前記［１］または［２］に記載の気体分離膜。
［４］前記アミノ基が下記式（４）：

｛式中、Ｚ₁はＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する。｝で表される、前記［３］に記載の気体分離膜。
［５］前記部位（Ａ）と前記部位（Ｂ）の割合が、部位（Ａ）１００質量部を基準として部位（Ｂ）が５〜２５０質量部であるものである、前記［１］〜［４］のいずれかに記載の気体分離膜。
［６］分子鎖両末端にシラノール基を有するオルガノポリシロキサン（Ｃ）とアルコキシシリル基で少なくとも片末端が末端封止されたポリエチレンオキシド（Ｄ）を重縮合反応して前記架橋ポリマーを得る工程、及び
得られた架橋ポリマーを用いて気体分離膜を製造する工程、
を含む、前記［１］〜［５］のいずれかに記載の気体分離膜の製造方法。
［７］前記分子鎖両末端にシラノール基を有するオルガノポリシロキサン（Ｃ）が下記式（５）：

｛式中、Ｒ₁およびＲ₂は、炭素数１〜１０の非置換または置換の１価炭化水素基であり、そしてｎは５〜２０００の整数である。｝で表される化合物であり、かつ、前記アルコキシシリル基で少なくとも片末端が末端封止されたポリエチレンオキシド（Ｄ）が下記式（６）：

｛式中、Ｒ₃はＨまたは有機基であり、Ｒ₄およびＲ₅は水酸基、アルコキシ基または有機基であり、Ｙ₁およびＹ₂は２価の有機基であり、そしてｍは１〜１００の整数である。｝で表される化合物または下記式（７）：

｛式中、Ｒ₃はＨまたは有機基であり、Ｒ₄およびＲ₅は水酸基、アルコキシ基または有機基であり、Ｙ₁は２価の有機基であり、Ｙ₃は１価の有機基であり、そしてｍは１〜１００の整数である。｝で表される化合物である、前記［６］に記載の方法。
［８］前記式（６）中のＹ ₁ およびＹ ₂ ならびに前記式（７）中のＹ ₁ がアミノ基、ウレア基、ウレタン基およびチオエーテル基から選ばれた少なくとも１種の基である、前記［７］に記載の方法。
［９］前記アミノ基が下記式（８）：

｛式中、Ｚ₁はＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する。｝で表される、前記［８］に記載の方法。 [1] A gas separation membrane having at least a cross-linked polymer component, the gas is carbon dioxide, and crosslinked polymer, a repeating unit part (A) and ethylene oxide to repeating units of siloxane The following formula (1) having the site (B ):

{Wherein R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and m is an integer of 1 to 100. And n is an integer from 5 to 2000. } The gas separation membrane characterized by having a structure represented by these .
[2] The crosslinked polymer is represented by the following formula (2) :

{In the formula, R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms; Y ₁ and Y ₂ are divalent organic groups; It is an integer of 100, and n is an integer of 5 to 2000. } Structure Zoma other represented by the following formula (3):

{In the formula, R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and Y ₃ is a monovalent organic group. a machine group, m is an integer of 1 to 100, and n is an integer of 5 to 2,000. } The gas separation membrane according to [1], which has a structure represented by :
[3] the above formula (1) to (3) Y ₁ and Y ₂ are amino groups in a urea group, Ru least one group Der selected from urethane groups and thioether groups, the [1] or The gas separation membrane according to [2] .
[4] The amino group is lower following formula (4):

{In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the hydroxypropyl side is bonded to oxygen. } The gas separation membrane according to [3], which is represented by :
[5] the proportion of the site (A) and the site (B) is intended site (B) is 5 to 250 parts by weight based on site (A) 100 parts by mass of the [1] to [ 4] . The gas separation membrane according to any one of [ 4] .
Step of obtaining the crosslinked polymer [6] The organopolysiloxane (C) alkoxysilyl polyethylene oxide at least one terminal has been end-capped with groups having both molecular chain terminals to silanol groups (D) to a polycondensation reaction, as well as
A step of producing a gas separation membrane using the obtained crosslinked polymer ,
The manufacturing method of the gas separation membrane in any one of said [1]-[5] containing .
[7] The organopolysiloxane (C) is lower following formula having a molecular chain silanol end groups (5):

{ Wherein R ₁ and R ₂ are each an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 5 to 2000. A compound represented by}, and the alkoxy polyethylene oxide at least one terminal has been end-capped with silyl groups (D) is lower following formula (6):

{ Wherein R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group , an alkoxy group or an organic group, Y ₁ and Y ₂ are divalent organic groups, and m is 1 to 100 Is an integer. A compound represented by monomers other below following formula in} (7):

{Wherein, R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group, an alkoxy group or an organic group, Y ₁ is a divalent organic group, Y ₃ is a monovalent organic group And m is an integer from 1 to 100. } The method of the above- mentioned [6], which is a compound represented by
[8] at least one group Y ₁ in the formula (6) Y ₁ and Y ₂ and the formula in (7) in was chosen amino group, a urea group, a urethane group and a thioether group, wherein The method according to [7] .
[9] The amino group is lower following formula (8):

{In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the hydroxypropyl side is bonded to oxygen. } The method according to [8], which is represented by :

  The gas separation membrane of the present invention has a high carbon dioxide permeability coefficient and is excellent in carbon dioxide / nitrogen selectivity.

It is a figure explaining the gas permeation measuring device.

Hereinafter, the gas separation membrane of the present invention will be described in detail.
The gas separation membrane of the present invention is a gas separation membrane having at least a crosslinked polymer as a constituent component, wherein the crosslinked polymer has a site (A) having a siloxane as a repeating unit and a site (B) having an ethylene oxide as a repeating unit. It is characterized by that.

(式中、Ｒ₁およびＲ₂は炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁は２価の有機基であり、ｍは１〜１００の整数であり、ｎは５〜２０００の整数である。） Preferably, the gas separation membrane of the present invention is composed of a crosslinked polymer represented by the following general formula (1) and having a structure in which organopolysiloxane and polyethylene oxide are bonded via a siloxane bond. By combining an organopolysiloxane having a high carbon dioxide permeability coefficient and polyethylene oxide having excellent carbon dioxide / nitrogen selectivity, a membrane having high permeability can be obtained.

(In the formula, R ₁ and R ₂ are unsubstituted or substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, m is an integer of 1 to 100, n is an integer of 5 to 2000.)

（式中、Ｒ₁およびＲ₂は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁およびＹ₂は２価の有機基であり、ｍは１〜１００の整数であり、ｎは５〜２０００の整数である。）

（式中、Ｒ₁およびＲ₂は各々独立に炭素数１〜１０の非置換または置換の１価炭化水素基であり、Ｙ₁は２価の有機基であり、Ｙ₃は１価の有機残基であり、ｍは１〜１００の整数であり、ｎは５〜２０００の整数である。）
二酸化炭素の選択性の観点から、上記式（３）で表される構造を主成分として有することが好ましい。上記式（３）で表される構造はエチレンオキシド鎖の片末端が残基であるため、膜にした際エチレンオキシド鎖の自由度が高いと推測される。自由度の高いエチレンオキシド鎖は二酸化炭素と容易に相互作用し、気体分離膜にした際の二酸化炭素の選択性が良好になるため好ましい。 More preferably, the crosslinked polymer having the site (A) having the repeating unit of siloxane and the site (B) having the repeating unit of ethylene oxide has the structure represented by the following formula (2) and / or the following formula (3). It has the structure represented.

Wherein R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ and Y ₂ are divalent organic groups, and m is 1 to (It is an integer of 100, and n is an integer of 5 to 2000.)

Wherein R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and Y ₃ is a monovalent organic group. A residue, m is an integer from 1 to 100, and n is an integer from 5 to 2000.)
From the viewpoint of the selectivity of carbon dioxide, it is preferable to have the structure represented by the above formula (3) as a main component. In the structure represented by the above formula (3), since one end of the ethylene oxide chain is a residue, it is presumed that the degree of freedom of the ethylene oxide chain is high when formed into a film. An ethylene oxide chain having a high degree of freedom is preferable because it easily interacts with carbon dioxide, and the selectivity of carbon dioxide is improved when a gas separation membrane is formed.

  In order to describe the gas separation membrane of the present invention in more detail, first, a method for producing the crosslinked polymer constituting the gas separation membrane will be described. However, it is not limited to this production method, and any production method may be used as long as a crosslinked polymer having the above structure is obtained.

（式中、Ｒ₁およびＲ₂は、炭素数１〜１０の非置換または置換の１価炭化水素基であり、ｎは５〜２０００の整数である。） The crosslinked polymer in the present invention is obtained by polycondensation reaction between an organopolysiloxane (C) having silanol groups at both ends of a molecular chain and polyethylene oxide (D) having at least one end blocked with an alkoxysilyl group.
The organopolysiloxane (C) having silanol groups at both ends of the molecular chain is preferably a compound represented by the following formula (5).

(In the formula, R ₁ and R ₂ are each an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 5 to 2000.)

In the compound represented by the above formula (5), R ₁ and R ₂ are an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Specific examples of R ₁ and R ₂ include methyl groups, ethyl groups, propyl groups, butyl groups, octyl groups and other alkyl groups; cyclopentyl groups, cyclohexyl groups and other cycloalkyl groups; vinyl groups, allyl groups, hexenyls. An alkenyl group such as a group; an aryl group such as a phenyl group and a tolyl group; and a halogen-substituted alkyl group such as a chloromethyl group and a 3,3,3-trifluoropropyl group. From the viewpoint of gas permeability, R ₁ and R ₂ are preferably methyl groups. R ₁ and R ₂ may be the same group or different groups.
In the compound represented by the above formula (5), n represents an integer of 5 to 2000. It is preferable that n is an integer of 5 to 2,000 because a remarkable effect is exerted on carbon dioxide permeability and selectivity when the gas separation membrane is used.

  Specific examples of the organopolysiloxane of component (C) include dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, and methyl (3,3,3-trifluoropropyl). ) Polysiloxane, a copolymer of dimethylsiloxane and methylphenylsiloxane, and a copolymer of dimethylsiloxane and methyl (3,3,3-trifluoropropyl) siloxane. In the present invention, these may be used alone or as a mixture of two or more.

（式中、Ｒ₃はＨまたは有機基であり、Ｒ₄およびＲ₅は水酸基またはアルコキシ基または有機基であり、Ｙ₁およびＹ₂は２価の有機基であり、ｍは１〜１００の整数である。）

（式中、Ｒ₃はＨまたは有機基であり、Ｒ₄およびＲ₅は水酸基またはアルコキシ基または有機基であり、Ｙ₁は２価の有機基であり、Ｙ₃は１価の有機残基であり、ｍは１〜１００の整数である。） The polyethylene oxide (D) having at least one end capped with an alkoxysilyl group is preferably a compound represented by the following formula (6) and / or (7).

(Wherein R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group, an alkoxy group or an organic group, Y ₁ and Y ₂ are divalent organic groups, and m is 1 to 100. (It is an integer.)

Wherein R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group, an alkoxy group or an organic group, Y ₁ is a divalent organic group, and Y ₃ is a monovalent organic residue. And m is an integer from 1 to 100.)

  Particularly preferably, from the viewpoint of the selectivity of carbon dioxide when used as a gas separation membrane, the component (D) has a compound represented by the above formula (7) as a main component. In the compound represented by the above formula (7), since one end of the ethylene oxide chain is a residue, it is presumed that the degree of freedom of the ethylene oxide chain is high when formed into a film. An ethylene oxide chain having a high degree of freedom is preferable because it easily interacts with carbon dioxide, and the selectivity of carbon dioxide is improved when a gas separation membrane is formed.

In the compounds represented by the above formulas (6) and (7), specific examples of R ₃ include H and alkyl groups such as methyl, ethyl, propyl, butyl, octyl and ethoxymethyl groups. Can be mentioned. From the viewpoint of the reactivity of the polycondensation reaction, H, a methyl group, and an ethyl group are preferable.
Specific examples of R ₄ and R _{5 in} the compounds represented by the above formulas (6) and (7) include alkoxy groups such as hydroxyl group, methoxy group and ethoxy group, alkyl groups such as methyl group, ethyl group and propyl group. Groups. From the viewpoint of reactivity during the polycondensation reaction, a hydroxyl group, a methoxy group, and an ethoxy group are preferable. R ₄ and R ₅ may be the same group or different groups.

  In the compounds represented by the above formulas (6) and (7), m representing the length of the ethylene oxide repeating unit is an integer of 5 to 100. m is preferable because when 5 or more is a gas separation membrane, the carbon dioxide permeation selectivity becomes high. On the other hand, m is preferably 100 or less because the strength and heat resistance of the film are kept high. That is, when m is an integer of 5 to 100, both carbon dioxide permeation selectivity, membrane strength and heat resistance can be satisfied.

The compounds represented by the above formulas (6) and (7) are obtained by reacting polyethylene glycol (E) having a reactive group at both ends with alkoxysilane (F) having a reactive group.
In the compounds represented by the above formulas (6) and (7), Y ₁ and Y ₂ preferably have at least one group selected from an amino group, a urea group, a urethane group and a thioether group. Y ₁ and Y ₂ are linking groups resulting from the reaction of the components (E) and (F).

Examples of reactions for synthesizing compounds in which Y ₁ and Y ₂ have an amino group among the compounds represented by the above formulas (6) and (7) include, for example, polyethylene glycol diglycidyl ether as component (E), (F) As components, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propyltriethoxysilane, 3- (2 A combination of a compound selected from -aminoethylamino) propyldimethoxymethylsilane and trimethoxy (3- (phenylamino) propyl) silane.

Examples of reactions for synthesizing compounds in which Y ₁ and Y ₂ have a urea group among the compounds represented by the above formulas (6) and (7) include, for example, poly (ethylene glycol) bis (3- (Aminopropyl) terminal and (F) component may be a combination of 3- (triethoxysilyl) propyl isocyanate and a compound selected from 3- (trimethoxysilyl) propyl isocyanate.

Examples of reactions for synthesizing compounds in which Y ₁ and Y ₂ have a urethane group among the compounds represented by the above formulas (6) and (7) include, for example, poly (ethylene glycol), (F) as component (E) A combination of compounds selected from 3- (triethoxysilyl) propyl isocyanate and 3- (trimethoxysilyl) propyl isocyanate as the component, (E) poly (ethylene glycol) bis (chloroformate), (F) As components, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propyltriethoxysilane, 3- (2 -Aminoethylamino) propyldimethoxymethylsilane, trimethoxy (3- (phenylamino) Propyl) union of the compounds selected from the silane.

Examples of the reaction for synthesizing a compound in which Y ₁ and Y ₂ have a thioether group among the compounds represented by the above formulas (6) and (7) include, for example, polyethylene glycol diglycidyl ether, polyethylene glycol diester as component (E). Compound selected from vinyl ether, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, combination of compounds selected from 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane as component (F), polyethylene glycol as component (E) Examples of the dithiol and (F) component include a combination of compounds selected from vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris (2-methoxyethoxy) silane.

  The compounds represented by the above formulas (6) and (7) can be prepared depending on the blending ratio of the (E) component and the (F) component. (E) When the number of moles of the reactive group of the reactive group of the component (F) is more than twice the number of moles of the reactive group of the reactive group of the component (E), alkoxysilane is present at both ends represented by the above formula (6). Is obtained as a main component. When the number of moles of the reactive group of the reactive group of the component (E) is more than twice the number of moles of the reactive group of the reactive group of the component (F), alkoxysilane is present at one end represented by the above formula (7). Is obtained as a main component. For example, 1 mol of polyethylene glycol diglycidyl ether having 2 reactive sites as component (E) and 2 mol of 3-aminopropyltrimethoxysilane having an amino group having 2 reactive sites as component (F) In such a case, the compound represented by the above formula (6) is obtained as a main component. On the other hand, 2 moles of polyethylene glycol diglycidyl ether having 2 reactive sites as component (E) and 1 mole of 3-aminopropyltrimethoxysilane having an amino group having 2 reactive sites as component (F) In such a case, the compound represented by the above formula (7) is obtained as the main component.

In the compound represented by the above formula (7), Y ₃ is a monovalent organic residue. This is an organic residue when the (E) component reacts with the (F) component. When the gas separation membrane is used, Y ₃ is a monovalent organic residue, so that the ethylene oxide chain is fixed to the polymer chain only at one end, and it is assumed that the ethylene oxide chain has a high degree of freedom. An ethylene oxide chain having a high degree of freedom is preferable because it easily interacts with carbon dioxide and improves the selectivity of carbon dioxide when formed into a membrane.

（式中、Ｚ₁はＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する。）
（Ｅ）成分として反応性基がエポキシ基の化合物、（Ｆ）成分として反応性基が３−アミノプロピル基の化合物を用いた場合、Ｙ₁およびＹ₂が上記一般式（８）で表される化合物を合成できる。 In the compounds represented by the above formulas (6) and (7), Y ₁ and Y ₂ preferably have a structure represented by the following formula (8). The compound in which Y ₁ and Y ₂ are represented by the following formula (8) has an amino group and a hydroxyl group having high affinity for carbon dioxide in Y ₁ and Y _2, and carbon dioxide when used as a gas separation membrane. This is preferable because of good selectivity.

(In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si, and the bond on the hydroxypropyl side is bonded to oxygen.)
When a compound having a reactive group as an epoxy group is used as the component (E) and a compound having a 3-aminopropyl group as the reactive group is used as the component (F), Y ₁ and Y ₂ are represented by the general formula (8). Can be synthesized.

In the above formula (8), Z ₁ is a monovalent organic group. From the viewpoint of carbon dioxide selectivity when using a gas separation membrane, Z ₁ preferably has an ethylene oxide chain having a high affinity for carbon dioxide. For example, 2 moles of polyethylene glycol diglycidyl ether having 2 reactive sites as component (E) and 1 mole of 3-aminopropyltrimethoxysilane having an amino group having 2 reactive sites as component (F) If so, a compound having an ethylene oxide chain at Z ₁ is obtained.

  When synthesizing the compounds represented by the above formulas (6) and (7), depending on the blending ratio of the (E) component and the (F) component, the compounds represented by the above formulas (6) and (7), It may be obtained as a mixture of unreacted (E) component and / or unreacted (F) component. In that case, you may create a gas separation membrane using a mixture, without refine | purifying the compound shown by said Formula (6), (7). For example, when the compound is synthesized by adding the component (E) in excess of the component (F), a mixture of the compound represented by the above formulas (6) and (7) and the unreacted component (E). Can be used to make a gas separation membrane. In this case, an unreacted (E) component ethylene oxide chain is present in the film. The unreacted (E) component exists as a liquid, and the degree of freedom of the ethylene oxide chain of the unreacted (E) component is high and easily interacts with carbon dioxide, so that the selectivity of carbon dioxide is improved.

  The component (D) is most preferably a combination of polyethylene oxide having glycidyl groups at both ends as the component (E) and 3-aminopropyltrimethoxysilane and / or 3-aminopropyltriethoxysilane as the component (F). This is a compound synthesized by The reaction ratio between the two is a standard in which 1 mol of amino group is reacted with 1 mol of glycidyl group, but with 1 mol of glycidyl group, the amino group is reacted in the range of 0.8 to 1.2 mol. Can do. The reaction is carried out at a reaction temperature of 0 to 150 ° C., preferably 20 to 100 ° C., for 0.5 to 100 hours, preferably 2 to 50 hours, more preferably 2 to 10 hours.

  The above reaction can be performed without a solvent, and alcohol solvents such as methanol, ethanol, isopropanol, and butanol; tetrahydrofuran, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, Ether solvents such as ethylene glycol diethyl ether; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; aprotic polar solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; halogen solvents such as dichloromethane and chloroform; One or two or more selected from aromatic solvents such as toluene and xylene can be mixed and used.

  A catalyst may be used for the reaction. Specific examples of the catalyst include 1,8-diaza-bicyclo [5.4.0] -7-undecene, triethylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol, and 2- (dimethylaminomethyl). Tertiary amines such as phenol, dimethylbenzylamine, dimethylcyclohexylamine, triethanolamine, dimethylaminoethanol, N-methylmorpholine, tetramethylpropylenediamine, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine and their salts; Examples include organic phosphine compounds such as methyldiphenylphosphine, triphenylphosphine, and tris (dimethoxyphenyl) phosphine.

The addition reaction of polyethylene oxide having glycidyl groups at both ends and 3-aminopropyltrimethoxysilane and / or 3-aminopropyltriethoxysilane described above is performed by nuclear magnetic resonance analysis ( ¹ H-NMR method) or Fourier transform. It can be traced by an analytical method such as infrared spectroscopy (FT-IR method).

The gas separation membrane of the present invention will be described based on the above-described method for producing a crosslinked polymer.
In the compounds represented by the above formulas (1), (2), and (3), R ₁ and R ₂ are unsubstituted or substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms. Specific examples of R ₁ and R ₂ include methyl groups, ethyl groups, propyl groups, butyl groups, octyl groups and other alkyl groups; cyclopentyl groups, cyclohexyl groups and other cycloalkyl groups; vinyl groups, allyl groups, hexenyls. An alkenyl group such as a group; an aryl group such as a phenyl group and a tolyl group; and a halogen-substituted alkyl group such as a chloromethyl group and a 3,3,3-trifluoropropyl group. From the viewpoint of gas permeability, R ₁ and R ₂ are preferably methyl groups. R ₁ and R ₂ may be the same group or different groups.

  In the compounds represented by the above formulas (1), (2) and (3), n represents an integer of 5 to 2000. It is preferable that n is an integer of 5 to 2,000 because a remarkable effect is exerted on carbon dioxide permeability and selectivity when the gas separation membrane is used.

  In the compounds represented by the above formulas (1), (2) and (3), m representing the length of the ethylene oxide repeating unit is an integer of 5 to 100. When m is 5 or more, the permeation selectivity of carbon dioxide is increased when a gas separation membrane is used. On the other hand, m is preferably 100 or less because the strength and heat resistance of the gas separation membrane are kept high. That is, when m is 5 to 100, both carbon dioxide permeation selectivity, membrane strength, and heat resistance can be satisfied.

In the compounds represented by the above formulas (1), (2) and (3), Y ₁ and Y ₂ preferably have a linking group selected from an amino group, a urea group, a urethane group and a thioether group. These linking groups are linking groups for linking the (E) component and the (F) component used to synthesize the (D) component. That is, Y ₁ and Y ₂ are formed by a combination of the reactive group of the component (E) and the reactive group of the component (F).

（上記式中、Ｒ₆およびＲ₇は各々独立にＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する。） Specific examples of Y ₁ and Y ₂ having the amino group include linking groups having the structure shown below.

(In the above formula, R ₆ and R ₇ are each independently H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the hydroxypropyl side is bonded to oxygen.)

（Ｒ₆およびＲ₇は各々独立にＨまたは１価の有機基である） Specific examples of Y ₁ and Y ₂ having the urea group include linking groups having the structure shown below.

(R ₆ and R ₇ are each independently H or a monovalent organic group)

（上記式中、Ｒ₆およびＲ₇は各々独立にＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、カルボニル側の結合手が酸素と結合する。） Specific examples of Y ₁ and Y ₂ having the urethane group include linking groups having the structure shown below.

(In the above formula, R ₆ and R ₇ are each independently H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the carbonyl side is bonded to oxygen.)

（上記式中、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する。）

（上記式中プロピル側の結合手がＳｉと結合し、エチル側の結合手が酸素と結合する。）

Specific examples of Y ₁ and Y ₂ having the thioether group include linking groups having the structure shown below.

(In the above formula, the bond on the propyl side is bonded to Si, and the bond on the hydroxypropyl side is bonded to oxygen.)

(In the above formula, the bond on the propyl side is bonded to Si, and the bond on the ethyl side is bonded to oxygen.)

(式中、Ｚ₁はＨまたは１価の有機基であり、プロピル側の結合手がＳｉと結合し、ヒドロキシプロピル側の結合手が酸素と結合する)
上記一般式（４）で表される構造は架橋ポリマーを得る際に用いる（Ｄ）成分を合成する際の連結基である。つまり、（Ｅ）成分と（Ｆ）成分を連結するための連結基である。例えば、（Ｅ）成分として反応性基がエポキシ基の化合物、（Ｆ）成分として反応性基が３−アミノプロピル基の化合物を用いた場合、Ｙ₁およびＹ₂が上記一般式（４）で表される化合物を合成できる。Ｙ₁およびＹ₂が上記一般式（４）で表されると、Ｙ₁およびＹ₂に二酸化炭素と親和性の高いアミノ基と水酸基を有し、気体分離膜にした際の二酸化炭素の選択性が良好になるため好ましい。 In the compounds represented by the above formulas (1), (2) and (3), Y ₁ and Y ₂ preferably have a structure represented by the following general formula (4).

(In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si, and the bond on the hydroxypropyl side is bonded to oxygen)
The structure represented by the general formula (4) is a linking group for synthesizing the component (D) used for obtaining a crosslinked polymer. That is, it is a linking group for linking the (E) component and the (F) component. For example, when a compound having a reactive group as an epoxy group is used as the component (E) and a compound having a 3-aminopropyl group as the reactive group is used as the component (F), Y ₁ and Y ₂ are represented by the general formula (4). The compounds represented can be synthesized. When Y ₁ and Y ₂ are represented by the above general formula (4), selection of carbon dioxide when Y ₁ and Y ₂ have an amino group and a hydroxyl group having high affinity with carbon dioxide to form a gas separation membrane This is preferable because the property is improved.

In the above formula (4), Z ₁ is a monovalent organic group. Z ₁ is, in terms of carbon dioxide selectivity when it is used for a gas separation membrane, Z ₁ preferably has a high ethylene oxide chains of carbon dioxide and affinity. For example, when synthesizing the component (D), the Z ₁ group has 2 moles of polyethylene glycol diglycidyl ether having two reactive sites as the component (E) and two reactive sites as the component (F). When 1 mol of 3-aminopropyltrimethoxysilane having an amino group is used, a compound having an ethylene oxide chain at Z ₁ is obtained.

In the above formula (3), Y ₃ is a monovalent organic residue. Specific examples include organic residues having a hydroxyl group, an epoxy group, an amino group, an isocyanate group, an acrylic group, a methacryl group, a vinyl group, a thiol group, or a carbonyl group. The organic residue is an organic residue when the component (E) reacts with the component (F) when the component (D) is synthesized. When Y ₃ is a gas separation membrane, since Y ₃ is a monovalent organic residue, only one end of the ethylene oxide chain is fixed to the polymer chain. Therefore, it is estimated that the ethylene oxide chain has a high degree of freedom. An ethylene oxide chain having a high degree of freedom is preferable because it easily interacts with carbon dioxide and improves the selectivity of carbon dioxide when formed into a membrane.

  In the gas separation membrane of the present invention, the ratio of the part (A) and the part (B) is 5 to 250 parts by mass, more preferably 10 to 200 parts by mass, with the part (B) as a reference based on 100 parts by mass of the part (A). Parts, more preferably in the range of 10 to 150 parts by mass. If there are too many sites (B) relative to sites (A), the resulting membrane undergoes phase separation and is not suitable as a gas separation membrane.

  The gas separation membrane of the present invention can be produced by polycondensation of the component (C) and the component (D). Preferably, from the viewpoint of carbon dioxide permeability and selectivity when a gas separation membrane is used, the component (C) is a compound represented by the general formula (5), and the component (D) is the general formula (6). And / or a compound represented by the following general formula (7).

  The reaction method of the component (C) and the component (D) is not particularly limited, but the method of mixing the component (C) and the component (D) and then hydrolyzing and condensing the component with the humidity in the air, the component (D) and the water. And a method of condensing with the component (C) after hydrolyzing the alkoxysilyl groups at both ends to silanol groups.

  When (D) component is made to react with water beforehand, it is preferable that the usage-amount of water shall be 3 mol with respect to 1 mol of alkoxysilyl groups in (D) component. For the purpose of promoting the hydrolysis reaction of the alkoxy group, an acid catalyst selected from hydrochloric acid, sulfuric acid, nitric acid, formic acid and the like, and a base catalyst such as ammonia and amine can be used in combination. The amount of the catalyst used is in the range of 0.001 to 0.5 mol, more preferably 0.01 to 0.2 mol, and still more preferably 0.05 to 0.2 mol, with respect to 1 mol of the alkoxysilyl group. . Although the reaction temperature and reaction time depend on the type and amount of catalyst used, the reaction temperature is -20 to 90 ° C, more preferably -5 to 50 ° C, still more preferably 0 to 20 ° C, and the reaction time. Is in the range of 0.1 to 30 hours, more preferably 0.2 to 10 hours, still more preferably 0.2 to 5 hours. This reaction can be carried out in the absence of a solvent, and can also be carried out continuously in the solvent used in the preparation of component (D).

  Component (C) and component (D) are reacted in the absence of a solvent, and alcohol solvents such as methanol, ethanol, isopropanol, and butanol; tetrahydrofuran, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, Ether solvents such as ethylene glycol monobutyl ether, ethylene glycol dimethyl ether and ethylene glycol diethyl ether; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; aprotic polar solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; Halogen solvents such as dichloromethane and chloroform; one or two or more kinds selected from aromatic solvents such as toluene and xylene are used in combination. It is possible. Preferred are tetrahydrofuran, dichloromethane, and chloroform, which easily dissolve the hydrophobic component (C) and the hydrophilic component (D).

  The reaction between the component (C) and the component (D) is carried out in the range of 20 to 200 ° C., preferably 50 to 150 ° C., more preferably 50 to 100 ° C., and water, alcohol, and remaining solvent generated by the condensation reaction are removed. The reaction is carried out in the range of 1 to 100 hours, preferably 2 to 50 hours while removing under normal pressure or vacuum.

  A catalyst may be used for the purpose of promoting the condensation reaction between the component (C) and the component (D). Such catalysts include dibutyltin diacetate, dibutyltin dilaurate, dibutyltin bis (2-ethylhexylmalate), dibutyltin bis (butylmalate), dibutyltin bis (2,4-pentanedionate), dibutylbutoxychloro Tin, dioctyltin dilaurate, dioctyltin bis (butylmalate), dimethyltin dineodecanoate, bis (2-ethylhexanoate) tin, bisneodecanoatetin, bis (acetoxydibutyltin) oxide, bis (lauro) Organotin compounds such as xyldibutyltin) oxide; organics such as diisopropoxytitanium bis (acetylacetonate), titanium tetrakis (acetylacetonate), dioctanoxytitanium dioctinate, diisopropoxytitanium bis (ethylacetoacetate) Tan compounds, and the like can be mentioned. A catalyst can use together 1 type (s) or 2 or more types.

  In order to react the component (C) and the component (D) to obtain the gas separation membrane of the present invention, it is desirable to form both the components by polycondensation and at the same time form a thin film by a method such as casting or coating. The thin film may be a free-standing film, but a nonwoven fabric such as cellulose, polyester or polyphenylene sulfide; a microporous membrane such as polysulfone, polyethersulfone, polyacrylonitrile, polyethylene or polypropylene; a composite laminate of the nonwoven fabric and the microporous membrane, etc. A gas separation membrane having excellent durability and permeability can be obtained by using the support as a support and laminating and crosslinking the components (C) and (D) thereon. The shape of the support may be a flat membrane or a hollow fiber. The thickness of the gas separation membrane is in the range of 0.02 to 500 μm, preferably 0.05 to 100 μm, more preferably 0.05 to 10 μm, and still more preferably 0.05 to 1 μm.

  When the crosslinking reaction between the component (C) and the component (D) proceeds, the component becomes insoluble in the solvent, so that the progress of the crosslinking reaction can be easily confirmed. Further, the progress of the crosslinking reaction can be confirmed from the measurement of the glass transition temperature (Tg) by a differential scanning calorimeter (DSC) or dynamic viscoelasticity.

  In addition to the component (C) and the component (D), a crosslinking agent can be used in combination with the crosslinked polymer used in the present invention. The cross-linking agent is used to increase the cross-linking density and increase the film strength, heat resistance and durability, and examples thereof include a silane compound having a plurality of hydrolyzable functional groups and a partial hydrolysis condensate thereof. Specific examples of such a silane compound include oxime silanes such as methyltris (diethylketoxime) silane, methyltris (methylethylketoxime) silane, vinyltris (methylethylketoxime) silane, phenyltris (diethylketoxime) silane; methyltrimethoxysilane , Alkoxysilanes such as methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane; acetoxy such as methyltriacetoxysilane, ethyltriacetoxysilane Silane; methyltris (dimethylamino) silane, methyltris (diethylamino) silane, methyltris (N-methylacetamido) silane Emissions, vinyltris amino silane such as (N- ethylacetamido) silane; methyltris (dimethylamino) silane, methyl tris including but aminoxy silanes such as (diethylamino) silane, and the like. When a crosslinking agent is used in combination, the addition amount is preferably about 0.1 to 20% by weight with respect to the total weight of the component (C) and the component (D).

  In addition to the crosslinked polymer, a filler can be used in combination with the gas separation membrane of the present invention. Fillers are used to increase membrane strength and gas permeation performance, and include nano-sized silica such as fumed silica and colloidal silica; nano-sized metal oxides such as titanium oxide and zirconium oxide. Preferably used. When these fillers are used in combination, the addition amount is preferably about 0.1 to 50% by weight based on the weight of the crosslinked polymer.

  Further, in addition to these fillers, polydimethylsiloxane having both ends sealed with trimethylsilyl groups, or a copolymer of dimethylsiloxane and phenylmethylsiloxane may be added. These additives can be used to improve gas permeation performance. When these additives are used in combination, the amount added is preferably about 0.1 to 20% by weight based on the weight of the crosslinked polymer.

  Commercially available room temperature curable (RTV) silicone rubber in which additives such as the above-mentioned catalyst, crosslinking agent, filler and the like and polyorganopolysiloxane having silanol groups at both ends of the molecular chain as component (C) are premixed You may utilize a composition as (C) component. Examples of such silicone rubber compositions include KE44, KE45, KE441, KE445 manufactured by Shin-Etsu Chemical Co., Ltd .; TSE382 manufactured by Momentive Performance Materials, Inc., SH780, SE5007 manufactured by Toray Dow Corning Co., Ltd., etc. Can be mentioned.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited only to these Examples.
[Example 1]
<Synthesis of polyethylene oxide end-capped with alkoxysilyl groups>
First, the inside of a glass four-necked flask having an internal volume of 500 mL was purged with nitrogen, and 10.0 g of 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM903), ethanol (Tokyo Chemical Industry Co., Ltd.) ) Made: Special grade) 100 mL was added. This was stirred with a stirrer, and after dissolution, 47.5 g of diglycidyl ether of polyethylene oxide (PEO chain repeating unit number = 9, Mw = 526, manufactured by Aldrich) was added. The liquid temperature was increased to 90 ° C. at a rate of 3 ° C./min. The mixture was heated and refluxed at 90 ° C. for 72 hours, and after cooling, ethanol was separated and removed by using an evaporator and a vacuum pump. The obtained product was a yellowish viscous transparent liquid. The product was confirmed by ¹ H-NMR measurement, and it was confirmed that polyethylene oxide end-capped with an alkoxysilyl group (hereinafter abbreviated as PEO2) was synthesized.

<Production of gas separation membrane>
As the component (A), a commercially available oxime-type room temperature-curing silicone rubber TSE382 (made by Momentive Performance Materials Co., Ltd.) mainly composed of polydimethylsiloxane having silanol groups at both ends was used. 1.8 g of TSE382 was weighed and added to a 50 ml vial. 0.2 g of PEO2 synthesized earlier was added, and diluted to 10 wt% with THF (manufactured by Wako Pure Chemical Industries, Ltd.). The mixture was stirred with a wave rotor for 5 hours to obtain a uniform solution. The obtained liquid was developed in a PFA petri dish and allowed to stand in a vacuum dryer. The temperature was set to 50 ° C., the degree of vacuum was gradually increased over 5 hours, and the state was maintained at 0.13 KPa for 15 hours to obtain a uniform dense film having a thickness of 350 μm.

  The reaction between polydimethylsiloxane having silanol groups at both ends and PEO2 was confirmed from the change in Tg of PEO2 using DSC. That is, although PEO2 had Tg at −65 ° C., the Tg of PEO 2 at −65 ° C. disappeared by reacting with polydimethylsiloxane after film formation, and the Tg of the obtained gas separation membrane was −42. It was only one point at ° C. As a result, it was determined that polydimethylsiloxane having silanol groups at both ends and PEO2 were crosslinked to form a uniform structure.

<Gas permeation measurement>
For gas permeation measurement, K-415N manufactured by Tsukubarika Seiki Co., Ltd. shown in FIG. 1 was used. The gas permeability coefficient was obtained by the high vacuum method. As a measuring method, a membrane cut to a diameter of 5 cm is attached to a permeation cell, and the entire system is evacuated. At this time, only the gas supply valve (1) is closed, and the other valves are open. Confirm that the degree of vacuum of the entire system is 1 × 10 ⁻⁵ Torr or less. Next, the valve (2) is closed and the valve (1) is opened to introduce gas into the gas reservoir from the cylinder. After gas introduction, the valve (1) is closed. Next, the valves (3) and (4) before and after the permeation cell, and the edge valve (5) between the device and the vacuum pump are closed. The measurement is started by sequentially opening the valve (2) and the valve (3). During the measurement, the pressure on the gas supply side was adjusted to 760 Torr, and the pressure on the permeation side was 1 × 10 ⁻⁵ Torr or less. The gas used for the measurement is carbon dioxide, oxygen, and nitrogen, and the measurement temperature is 25 ° C.

The permeation coefficient P was determined by measuring and tracking the pressure increase on the permeation side due to the gas permeating through the membrane with the pressure gauge 2. Further, the delay time until the transmission curve reached a steady state was determined, and the diffusion coefficient D was determined by the Time-Lag method. Further, the solubility coefficient S was obtained from the permeability coefficient P and the diffusion coefficient D. The relationship of each parameter is as shown in the following formula.
P: Permeation coefficient [cm ³ (STP) cm / cm ² / s / cmHg]
D: Diffusion coefficient [cm ² / sec]
S: Solubility coefficient [cm ³ (STP) / cm ³ / cmHg]
L: Film thickness [cm]
θ: Delay time [sec]
D = L ² / 6θ
S = P / D
Tables 1 and 2 show the gas permeability coefficient, solubility coefficient, diffusion coefficient, gas selectivity, diffusion coefficient selectivity, and solubility coefficient selectivity of the obtained membrane.

[Examples 2 to 7]
A gas separation membrane was prepared in the same manner as in Example 1 except that the weight ratio of TSE382 and PEO2 was changed in Example 1, and a gas permeation test was performed. The results of the gas permeation test are shown in Tables 1 and 2. The membrane produced in Example 7 was phase-separated under these production conditions, and the permeation measurement was difficult.

[Comparative Example 1]
In Example 1, except that PEO2 was not used, a gas separation membrane was produced in the same manner as in Example 1, and a permeation test was performed. The results of the transmission test are shown in Tables 1 and 2.

  As is clear from Tables 1 and 2, the gas separation membrane of the present invention obtained by reacting polydimethylsiloxane having silanol groups at both ends and PEO2 has a gas selection as compared with the case of polydimethylsiloxane alone. It turns out that it is excellent in property. The gas selectivity was improved with an increase in the amount of PEO 2 added. In Example 6, the carbon dioxide / nitrogen selectivity was 25 or more. This is about 2.5 times the original selectivity of polydimethylsiloxane. It can be seen that this improvement in gas selectivity is the result of improved gas solubility selectivity. This is because the ethylene oxide structure introduced into PEO2 has a high affinity for carbon dioxide.

  On the other hand, the gas permeability coefficient tends to decrease with the addition of PEO2. However, as shown in Example 6, the carbon dioxide permeation coefficient exceeds 1000 Barrers and is extremely high. From the above, it was possible to impart a high carbon dioxide permeability coefficient and high carbon dioxide / nitrogen selectivity without significantly reducing the gas permeability coefficient inherent to polydimethylsiloxane by being able to introduce an ethylene oxide structure.

[Example 8]
Addition amount of diglycidyl ether of polyethylene oxide (PEO chain repeat unit number = 9, MW = 526, manufactured by Aldrich) from 47.5 g to 58.6 g, solvent from ethanol to methanol (manufactured by Wako Pure Chemical Industries, Ltd.) The compound was synthesized in the same manner as in Example 1 except that the above was changed. The obtained product was a yellowish viscous transparent liquid. As a result of ¹ H-NMR measurement, it was confirmed that it was a polyethylene oxide end-capped with an alkoxysilyl group (hereinafter abbreviated as PEO 3).
For film formation, a film was formed in the same manner as in Example 1 except that the amount of TSE382 added was 1.2 g instead of 1.8 g, and 0.8 g of PEO3 was added instead of 0.8 g of PEO2.
The gas permeation measurement was measured by the differential pressure method. In the gas permeability measurement, a differential pressure type gas / water vapor permeability measuring apparatus GTR30XAAS manufactured by GTRC, conforming to JIS K7126 was used. The measurement was performed at a permeation area of 15.2 cm ² and a differential pressure of 1 atm. The gas was detected by gas chromatography, and the transmittance was calculated from the area of the obtained chart. It was measured by 1-minute integration (accumulation time of permeated water vapor in the accumulation tube). The obtained gas permeability coefficient is shown in Table 3.

[Example 9]
Synthesis was carried out in the same manner as in Example 8 except that the amount of diglycidyl ether of polyethylene oxide (PEO chain repeat unit number = 9, Mw = 526, manufactured by Aldrich) was changed to 14.68 g. As a result of ¹ H-NMR measurement, it was confirmed that the polyethylene oxide was end-capped with an alkoxysilyl group. Film formation and gas permeation measurement were performed in the same manner as in Example 8. Table 3 shows the gas permeability coefficient of the obtained membrane.

[Example 10]
Diglycidyl ether of polyethylene oxide (PEO chain repeat unit number = 9, Mw = 526, manufactured by Aldrich) 58.6 g of ethylene oxide glycidyl ether (PEO chain repeat unit number = 4, epoxy equivalent (WPE) = 185, This was synthesized in the same manner as in Example 8 except that 19.43 g of EX821) manufactured by Nagase ChemteX Corporation was used. Film formation and gas permeation measurement were performed in the same manner as in Example 8. Table 3 shows the gas permeability coefficient of the obtained membrane.

[Example 11]
Diglycidyl ether of polyethylene oxide (PEO chain repeat unit number = 9, MW = 526, manufactured by Aldrich) instead of 58.6 g ethylene oxide glycidyl ether (PEO repeat unit number = 4, epoxy equivalent (WPE) = 185, Nagase Synthesized in the same manner as in Example 8 except that 4.82 g of EX821 manufactured by Chemtex Co., Ltd. was used. Film formation and gas permeation measurement were performed in the same manner as in Example 8. Table 3 shows the gas permeability coefficient of the obtained membrane.

[Example 12]
Diglycidyl ether of polyethylene oxide (PEO chain repeat unit number = 9, MW = 526, manufactured by Aldrich) instead of 58.6 g of ethylene oxide glycidyl ether (PEO chain repeat unit number = 21, epoxy equivalent (WPE) = 551, This was synthesized in the same manner as in Example 8 except that 123 g of EX861 manufactured by Nagase ChemteX Corporation was used. Film formation and gas permeation measurement were performed in the same manner as in Example 8. Table 3 shows the gas permeability coefficient of the obtained membrane.

[Example 13]
Polyethylene oxide glycidyl ether (PEO chain repeat unit number = 9, MW = 526, manufactured by Aldrich) 58.6 g instead of polyethylene oxide glycidyl ether (PEO chain repeat unit number = 21, epoxy equivalent (WPE) = 551) This was synthesized in the same manner as in Example 8 except that 30.2 g of EX861 manufactured by Nagase ChemteX Corporation was used. Film formation and gas permeation measurement were performed in the same manner as in Example 8. Table 3 shows the gas permeability coefficient of the obtained membrane.

[Comparative Example 2]
In Example 8, a gas separation membrane was prepared in the same manner as in Example 8 except that PEO3 was not used, and a permeation test was performed. The results of the transmission test are shown in Table 3.

  As is apparent from Table 3, the permeation performance when formed into a film varies greatly depending on the blending ratio of polyethylene glycol (E) having reactive groups at both ends and alkoxysilane (F) having reactive groups. In particular, when the component (D) synthesized at a ratio of 1 mol of 3-aminopropyltrimethoxylane of the component (F) to 2 mol of polyethylene oxide diglycidyl ether of the component (E) is used, a high carbon dioxide / It was found that nitrogen selectivity was obtained. This is presumed that the ethylene oxide chain has a high degree of freedom when it is made into a film, because one end of the ethylene oxide chain is a residue when made into a film. It is presumed that the ethylene oxide chain having a high degree of freedom easily interacts with carbon dioxide, and the carbon dioxide / nitrogen selectivity when formed into a membrane is improved.

[Examples 14-18]
Using the membrane prepared in Example 8, the membrane measurement temperature conditions were changed to 25 ° C., 50 ° C. and 75 ° C., and the gas permeation measurement was performed in the same manner as in Example 8 under the non-humidified and humidified (80% RH) conditions. It was measured by the differential pressure method. Table 4 shows the measurement results.

  As is apparent from Table 4, it can be seen that the gas separation membrane of the present invention can be used satisfactorily at a temperature condition of 25 ° C. to 75 ° C. Moreover, the gas separation membrane of this invention can be used on humidification conditions. When measured under humidified conditions, there is an advantage that permselectivity is improved. This is presumably because water vapor was taken into the membrane and the affinity of carbon dioxide was improved.

[Comparative Example 3]
Using X-22-164A (manufactured by Shin-Etsu Silicone, g / mol = 860) and polyethylene glycol dimethacrylate (Mn = 475, manufactured by Aldrich), which is a polydimethylsiloxane having methacrylic groups at both ends, Created. 1.6 g of X-22-164A was weighed and added to a 50 ml vial. 0.4 g of polyethylene glycol dimethacrylate (Mn = 475, manufactured by Aldrich) was added, 80 mg of azobis (isobutyronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a radical generator, and methyl ethyl ketone (Wako Pure) The product was diluted to 10 wt% with Yakuhin Kogyo Co., Ltd. The mixture was stirred with a wave rotor for 5 hours to obtain a uniform solution. The obtained liquid was developed in a glass petri dish and allowed to stand in a vacuum dryer. The temperature was set at 70 ° C., and the degree of vacuum was gradually increased over 5 hours, and the state was maintained at 0.13 KPa for 15 hours. The film was shredded by curing shrinkage, and a free-standing film having an area required for evaluation measurement could not be obtained.

  The gas separation membrane of the present invention has a high carbon dioxide permeability coefficient and carbon dioxide / nitrogen selectivity. Therefore, the gas separation membrane of the present invention is used as a gas separation membrane for separating carbon dioxide from a carbon dioxide-containing mixed gas composed of carbon dioxide and nitrogen and / or air, or as a landfill gas (from wastes buried in the ground). It can be used as a gas separation membrane for separating carbon dioxide contained in the generated organic gas).

Claims (9)

A gas separation membrane having a constituent of at least a crosslinked polymer, the gas is carbon dioxide, and crosslinked polymer, a repeating unit of the site (A) and ethylene oxide to a repeating unit of the siloxane moiety ( The following formula (1) having B) :

{Wherein R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and m is an integer of 1 to 100. And n is an integer from 5 to 2000. } The gas separation membrane characterized by having a structure represented by these . The crosslinked polymer is represented by the following formula (2) :

{In the formula, R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms; Y ₁ and Y ₂ are divalent organic groups; It is an integer of 100, and n is an integer of 5 to 2000. } And / or the following formula (3) :

{In the formula, R ₁ and R ₂ are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, Y ₁ is a divalent organic group, and Y ₃ is a monovalent organic group. a machine group, m is an integer of 1 to 100, and n is an integer of 5 to 2,000. Having the structure represented by}, gas separation membrane of claim 1. Formula (1) to (3) Y ₁ and Y ₂ are amino groups in a urea group, Ru least one group Der selected from urethane groups and thioether groups, according to claim 1 or 2 Gas separation membrane. Lower following formula is the amino group (4):

{In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the hydroxypropyl side is bonded to oxygen. Represented by}, gas separation membrane of claim 3. The proportion of the site (A) and the site (B) is, the site (A) site (B) based on 100 parts by weight are those wherein 5 to 250 parts by weight, any of claims 1-4 one The gas separation membrane according to Item. Step of obtaining the crosslinked polymer of an organopolysiloxane (C) alkoxysilyl polyethylene oxide at least one terminal has been end-capped with groups having both molecular chain terminals to silanol groups (D) and polycondensation reactions and,
A step of producing a gas separation membrane using the obtained crosslinked polymer ,
The manufacturing method of the gas separation membrane as described in any one of Claims 1-5 containing this . Organopolysiloxane (C) is lower following formula having a silanol group in the molecular chain terminal (5):

{ Wherein R ₁ and R ₂ are each an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 5 to 2000. A compound represented by}, and the alkoxy polyethylene oxide at least one terminal has been end-capped with silyl groups (D) is lower following formula (6):

{ Wherein R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group , an alkoxy group or an organic group, Y ₁ and Y ₂ are divalent organic groups, and m is 1 to 100 Is an integer. A compound represented by monomers other below following formula in} (7):

{Wherein, R ₃ is H or an organic group, R ₄ and R ₅ are a hydroxyl group, an alkoxy group or an organic group, Y ₁ is a divalent organic group, Y ₃ is a monovalent organic group And m is an integer from 1 to 100. It is a compound represented by} The method of claim 6. Y ₁ and Y ₂ and Y ₁ is an amino group of the formula (7) in in the formula (6), a urea group, at least one group selected from urethane groups and thioether groups, in claim 7 The method described. Lower following formula is the amino group (8):

{In the formula, Z ₁ is H or a monovalent organic group, and the bond on the propyl side is bonded to Si and the bond on the hydroxypropyl side is bonded to oxygen. Represented by} The method of claim 8.

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