# US 10,478,786 B2 · Gas separation membrane, gas separation module, gas separation apparatus, and gas separation method

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- Number: US 10,478,786 B2
- Document ID: US10478786B2
- Status: Granted
- Kind: B2
- Application number: 15/679,160
- Filed: 2017-08-17
- Published: 2018-01-25
- Granted: 2019-11-19
- Earliest claimed: 2015-02-27
- Assignees: FUJIFILM Corporation
- Applicants: FUJIFILM Corporation
- Inventors: Koji Hironaka; Keisuke Kodama; Satoshi Sano
- Web page: https://patentgrep.com/patent/US10478786B2

## CPC

- B01D 71/64: Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
- B01D 53/228: {characterised by specific membranes}
- B01D 69/1214: {Chemically bonded layers, e.g. cross-linking}
- B01D 69/1216: {Three or more layers}
- B01D 71/701: {Polydimethylsiloxane}
- B01D 71/80: Block polymers
- C08G 73/1085: {Polyimides with diamino moieties or tetracarboxylic segments containing heterocyclic moieties}
- C08G 73/128: {the unsaturated precursors containing heterocyclic moieties in the main chain}
- C08G 73/22: Polybenzoxazoles
- C08G 77/455: containing polyamide, polyesteramide or polyimide sequences
- C09D 183/04: Polysiloxanes
- C10L 3/104: {Carbon dioxide}
- B01D 53/1475: {Removing carbon dioxide}
- B01D 69/02: characterised by their properties
- B01D 71/62: Polycondensates having nitrogen-containing heterocyclic rings in the main chain
- B01D 2256/22: Carbon dioxide
- B01D 2256/245: Methane
- B01D 2257/504: Carbon dioxide
- B01D 2257/7025: Methane
- B01D 2258/05: Biogas
- B01D 2325/023: Dense layer within the membrane
- C01B 32/55: Solidifying
- C07C 9/04: Methane (production by treatment of sewage C02F11/04; natural gas, synthetic natural gas C10L3/06)
- C10L 2290/548: Membrane- or permeation-treatment for separating fractions, components or impurities during preparation or upgrading of a fuel
- Y02C 20/20: of methane
- Y02C 20/40: of CO2
- Y02P 20/151: Reduction of greenhouse gas [GHG] emissions, e.g. CO2
- Y02P 20/156: Methane [CH4]
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A gas separation membrane has a gas separation layer containing a poly(benzoxazole-imide) compound in which the poly(benzoxazole-imide) compound having structural units represented by General formulae (I) and (II), or structural units represented by General formulae (I), (II) and (III) satisfies a specific molar quantity condition. In the formulae, X and Y each represent a single bond or a specific divalent linking group; L represents a specific divalent linking group including a phenylene group; and R represents a specific group. A gas separation module and a gas separation method use the gas separation membrane. A gas separation apparatus includes the gas separation module.

## Claims

### Claim 1

A gas separation membrane comprising:
a gas separation layer containing a poly(benzoxazole-imide) compound,
wherein the poly(benzoxazole-imide) compound satisfies a condition (A) or (B):
(A) the poly(benzoxazole-imide) compound has a structural unit represented by General formula (I) and a structural unit represented by General formula (II), and
in the poly(benzoxazole-imide) compound, a molar quantity m of the structural unit represented by General formula (I) and a molar quantity n of the structural unit represented by General formula (II) satisfy Mathematical expression 1;
(B) the poly(benzoxazole-imide) compound has the structural unit represented by General formula (I), the structural unit represented by General formula (II), and a structural unit represented by General formula (III), and
in the poly(benzoxazole-imide) compound, the molar quantity m of the structural unit represented by General formula (I), the molar quantity n of the structural unit represented by General formula (II), and a molar quantity q of the structural unit represented by General formula (III) satisfy Mathematical expression 2:
0.25≤m/n≤9.00(0<n), Mathematical expression 1:
0.25≤m/(n+q)≤9.00(0<n, 0<q), Mathematical expression 2:
where X and Y each represent a single bond, a divalent linking group selected from Group (IV) of linking groups, or a divalent linking group formed by combining one or two or more linking groups selected from Group (IV);
L represents a divalent linking group including a phenylene group provided that the phenylene group does not have an —OR group as a substituent; and
R represents COR1 or Si(R2)3 where R1 and R2 each represent an alkyl group,

### Claim 2 (depends on 1)

The gas separation membrane according to claim 1, wherein the poly(benzoxazole-imide) compound satisfies the condition (B), and L is a divalent linking group selected from Group (V),

### Claim 3 (depends on 2)

The gas separation membrane according to claim 2, wherein L is a divalent linking group represented by the following formula

### Claim 4 (depends on 1)

The gas separation membrane according to claim 1, wherein Y is a single bond or a divalent linking group selected from Group (IV-1),

### Claim 5 (depends on 1)

The gas separation membrane according to claim 1, wherein Y is a divalent linking group selected from Group (IV-2),

### Claim 6 (depends on 1)

The gas separation membrane according to claim 1, wherein Y is a divalent linking group represented by the following formula

### Claim 7 (depends on 1)

The gas separation membrane according to claim 1, wherein X is a single bond or a divalent linking group represented by the following formula

### Claim 8 (depends on 1)

The gas separation membrane according to claim 1, wherein the gas separation layer further contains a polymer other than the poly(benzoxazole-imide) compound.

### Claim 9 (depends on 1)

The gas separation membrane according to claim 1, wherein the gas separation layer is formed by heat-treating a layer containing a polyimide compound having a structural unit represented by General formula (VI) and a structural unit represented by General formula (VII),
where X, Y, and L respectively have the same definition as X, Y, and L in General formulae (II) and (III); and RZ represents a COR1 or Si(R2)3 where R1 and R2 each represent an alkyl group.

### Claim 10 (depends on 9)

The gas separation membrane according to claim 9, wherein RZ is COR1 or Si(R2)3 where R1 and R2 each represent an alkyl group.

### Claim 11 (depends on 9)

The gas separation membrane according to claim 9, wherein RZ is COR1 where R1 represents an alkyl group.

### Claim 12 (depends on 9)

The gas separation membrane according to claim 9, wherein RZ is COCH3.

### Claim 13 (depends on 9)

The gas separation membrane according to claim 9, wherein RZ is Si(R2)3 where R2 represents an alkyl group.

### Claim 14 (depends on 9)

The gas separation membrane according to claim 9, wherein a temperature of the heat-treating is 300° C. to 600° C.

### Claim 15 (depends on 1)

The gas separation membrane according to claim 1, wherein the gas separation membrane is an asymmetric membrane.

### Claim 16 (depends on 1)

The gas separation membrane according to claim 1, further comprising:
a siloxane compound layer disposed on the gas separation layer,
wherein a Si ratio of the siloxane compound layer after immersion in chloroform to the siloxane compound layer before immersion in chloroform, the Si ratio being calculated by Mathematical expression (I), is 0.6 to 1.0,
Si ratio=(Si-Kα X-ray intensity after immersion in chloroform)/(Si-Kα X-ray intensity before immersion in chloroform), Mathematical expression (1).

### Claim 17 (depends on 16)

The gas separation membrane according to claim 16, wherein the siloxane compound layer contains an organopolysiloxane compound having a structure in which siloxane compounds are linked to each other through a linking group selected from the group consisting of *—O-M-O—*, *—S-M-S—*, *—NRaC(═O)—*, *—NRbC(═O)NRb—*, *—O—CH2—O—*, *—S—CH2CH2—*, *—OC(═O)O—*, *—CH(OH)CH2OCO—*, *—CH(OH)CH2O—*, *—CH(OH)CH2S—*, *—CH(OH)CH2NRc—*, *—CH(CH2OH)CH2OCO—*, *—CH(CH2OH)CH2O—*, *—CH(CH2OH)CH2S—*, *—CH(CH2OH)CH2NRc—*, *—CH2CH2—*, *—C(═O)O−N+(Rd)3—*, *—SO3−N+(Re)3—*, and *—PO3H−N+(Rf)3—* ,
where M represents a divalent to tetravalent metal atom; Ra, Rb, Rc, Rd, Re, and Rf each independently represent a hydrogen atom or an alkyl group; and the symbol * represents a linking site.

### Claim 18 (depends on 17)

The gas separation membrane according to claim 17, wherein the metal atom M is a metal atom selected from the group consisting of Be, Mg, Ca, Sc, Y, Ti, Zr, V, Cr, Mo, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, and In.

### Claim 19 (depends on 16)

The gas separation membrane according to claim 16, wherein the siloxane compound layer has at least one structure represented by (a) or (b);
(a) a structure having a structure represented by General formula (1) and a structure represented by General formula (2) or General formula (3), and
(b) a structure represented by General formula (4),
where RS represents an alkyl group or an aryl group; LA represents a single bond or a divalent linking group; XA represents a linking group selected from the group consisting of *—O-M1-O—*, *—S-M1-S—*, *—O—CH2—O—*, *—S—CH2CH2—*, *—OC(═O)O—*, *—CH2CH2—*, and *—C(═O)O−N+(Rd)3—*,
where M1 represents Zr, Fe, Zn, B, Al, Ti, In, or Ga; Rd represents a hydrogen atom or an alkyl group; a1 and b1 are each an integer of 2 or more; the symbol * represents a linking site; and the symbol ** represents a linking site in a siloxane bond.

### Claim 20 (depends on 19)

The gas separation membrane according to claim 19, wherein the structure of (a) further has a repeating unit represented by Formula (5),

### Claim 21 (depends on 20)

The gas separation membrane according to claim 20, wherein a content ratio of the repeating unit represented by Formula (5) in the siloxane compound layer is 0.01 to 0.55.

### Claim 22 (depends on 1)

A gas separation module comprising the gas separation membrane according to claim 1.

### Claim 23 (depends on 22)

A gas separation apparatus comprising the gas separation module according to claim 22.

### Claim 24 (depends on 1)

A gas separation method comprising supplying gas to the gas separation membrane according to claim 1.

### Claim 25 (depends on 24)

The gas separation method according to claim 24, wherein carbon dioxide is selectively permeated through the gas separation membrane to be separated from methane contained in the gas.

### Claim 26

A gas separation membrane comprising:
a gas separation layer containing a poly(benzoxazole-imide) compound,
wherein the poly(benzoxazole-imide) compound has a structural unit represented by General formula (I), a structural unit represented by General formula (II), and a structural unit represented by General formula (III), and
in the poly(benzoxazole-imide) compound, the molar quantity m of the structural unit represented by General formula (I), the molar quantity n of the structural unit represented by General formula (II), and a molar quantity q of the structural unit represented by General formula (III) satisfy the following Mathematical expression:
0.25≤m/(n+q)≤9.00(0<n, 0<q),
where X and Y each represent a single bond, a divalent linking group selected from Group (IV) of linking groups, or a divalent linking group formed by combining one or two or more linking groups selected from Group (IV);
L represents a divalent linking group selected from Group (V); and
R represents a hydrogen atom, COR1, or Si(R2)3 where R1 and R2 each represent an alkyl group,

### Claim 27

A gas separation membrane comprising:
a gas separation layer containing a poly(benzoxazole-imide) compound,
wherein the poly(benzoxazole-imide) compound has a structural unit represented by General formula (I), a structural unit represented by General formula (II), and a structural unit represented by General formula (III), and
in the poly(benzoxazole-imide) compound, the molar quantity m of the structural unit represented by General formula (I), the molar quantity n of the structural unit represented by General formula (II), and a molar quantity q of the structural unit represented by General formula (III) satisfy the following Mathematical expression:
0.25≤m/(n+q)≤9.00(0<n, 0<q),
where X and Y each represent a single bond, a divalent linking group selected from Group (IV) of linking groups, or a divalent linking group formed by combining one or two or more linking groups selected from Group (IV);
L represents a divalent linking group including a phenylene group provided that the phenylene group does not have an —OR group as a substituent; and
R represents a hydrogen atom, COR1, or Si(R2)3 where R1 and R2 each represent an alkyl group,
and
the gas separation layer is formed by heat-treating a layer containing a polyimide compound having a structural unit represented by General formula (II) and a structural unit represented by General formula (III).