# US 8,739,977 B2 · Composite semipermeable membrane and method for producing the same

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- Number: US 8,739,977 B2
- Document ID: US8739977B2
- Status: Granted
- Kind: B2
- Application number: 13/258,356
- Filed: 2010-03-18
- Published: 2012-02-02
- Granted: 2014-06-03
- Earliest claimed: 2009-03-31
- Assignees: Toray Industries, Inc.
- Applicants: Hiroki Minehara; Koji Nakatsuji
- Inventors: Hiroki Minehara; Koji Nakatsuji
- Web page: https://patentgrep.com/patent/US8739977B2

## CPC

- B01D 69/12: Composite membranes; Ultra-thin membranes
- B01D 67/0006: {by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125)}
- B01D 67/0088: {Physical treatment with compounds, e.g. swelling, coating or impregnation}
- B01D 71/70: Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only
- C02F 1/441: {by reverse osmosis}
- C09D 183/08: containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
- B01D 2323/02: Hydrophilization
- B01D 2323/34: Use of radiation
- B01D 2323/345: UV-treatment
- B01D 2323/40: in-situ membrane formation
- C02F 2103/08: Seawater, e.g. for desalination
- C08F 212/30: {Sulfur}
- C08G 77/26: nitrogen-containing groups
- Y02A 20/131: Reverse-osmosis
- 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)
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- 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)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

## Abstract

Disclosed herein are a composite semipermerable membrane and a method for producing the same. The composite semipermeable membrane comprises a microporous support membrane and a separation functional layer provided on the microporous support membrane, wherein the separation functional layer contains a condensation product produced by condensation of at least one selected from the group consisting of ions of trialkoxysilanes each having an imidazolium group and a conjugated base of a polymer having at least one acidic group. The composite semipermeable membrane achieves excellent selective separation of divalent ions over monovalent ions, and is suitable for use in various water treatment fields such as seawater desalination and drinking water production.

## Claims

### Claim 1

A composite semipermeable membrane comprising:
a microporous support membrane; and
a separation functional layer provided on the microporous support membrane, wherein the separation functional layer contains of a condensation product produced by condensation of at least one selected from among ions represented by the following general formula (1) and a conjugated base of a polymer having at least one acidic group:
wherein n is an integer of 1 to 4 and R1 and R2 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

### Claim 2 (depends on 1)

The composite semipermeable membrane according to claim 1, wherein the acidic group is at least one selected from among a carboxyl group, a sulfonate group, and a phosphonate group.

### Claim 3 (depends on 1)

The composite semipermeable membrane according to claim 1, wherein the conjugated base of the polymer is obtained by polymerizing a monomer or monomer mixture containing at least one conjugated base of a compound having at least one polymerizable double bond.

### Claim 4

A method for producing a composite semipermeable membrane comprising the step of forming a separation functional layer by applying, onto a microporous support membrane, a coating liquid containing a compound represented by the following general formula (2) and a monomer or monomer mixture containing at least one compound having an acidic group and at least one polymerizable double bond, irradiating it with energy rays, and drying it by heating:
wherein n is an integer of 1 to 4, R1 and R2 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Y− represents any anion.

### Claim 5 (depends on 2)

The composite semipermeable membrane according to claim 2, wherein the conjugated base of the polymer is obtained by polymerizing a monomer or monomer mixture containing at least one conjugated base of a compound having at least one polymerizable double bond.

### Claim 6 (depends on 1)

The composite semipermeable membrane according to claim 1, wherein the conjugated base of a polymer having at least one acidic group is selected from the group consisting of vinyl sulfonic acid and its salts, allyl sulfonic acid, o-styrene sulfonic acid and its salts, p-styrene sulfonic acid and its salts, m-styrenesulfonic acid and its salts, 2-vinylbenzoic acid and its salts, 3-vinylbenzoic acid and its salts, 4-vinylbenzoic acid and its salts, acrylic acid and its salts, methacrylic acid and its salts, 2-acryloyloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 3,5-diacrylamidebenzoic acid, vinylphosphonic acid, allylphosphonic acid, o-styrenephosphonic acid and its salts, p-styrenephosphonic acid and its salts, and m-styrenephosphonic acid and its salts.

### Claim 7 (depends on 2)

The composite semipermeable membrane according to claim 2, wherein the conjugated base of a polymer having at least one acidic group is selected from the group consisting of vinyl sulfonic acid and its salts, allyl sulfonic acid, o-styrene sulfonic acid and its salts, p-styrene sulfonic acid and its salts, m-styrenesulfonic acid and its salts, 2-vinylbenzoic acid and its salts, 3-vinylbenzoic acid and its salts, 4-vinylbenzoic acid and its salts, acrylic acid and its salts, methacrylic acid and its salts, 2-acryloyloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 3,5-diacrylamidebenzoic acid, vinylphosphonic acid, allylphosphonic acid, o-styrenephosphonic acid and its salts, p-styrenephosphonic acid and its salts, and m-styrenephosphonic acid and its salts.