Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/025—Reverse osmosis; Hyperfiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/027—Nanofiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
  • B01D67/0002—Organic membrane manufacture
  • B01D67/0006—Organic membrane manufacture by chemical reactions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
  • B01D67/0081—After-treatment of organic or inorganic membranes
  • B01D67/0093—Chemical modification
  • B01D67/00931—Chemical modification by introduction of specific groups after membrane formation, e.g. by grafting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/10—Supported membranes; Membrane supports
  • B01D69/107—Organic support material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/10—Supported membranes; Membrane supports
  • B01D69/107—Organic support material
  • B01D69/1071—Woven, non-woven or net mesh
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/12—Composite membranes; Ultra-thin membranes
  • B01D69/1214—Chemically bonded layers, e.g. cross-linking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/12—Composite membranes; Ultra-thin membranes
  • B01D69/125—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
  • B01D69/1251—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction by interfacial polymerisation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/56—Polyamides, e.g. polyester-amides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/12—Specific ratios of components used
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/30—Cross-linking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/20—Specific permeability or cut-off range
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/08—Seawater, e.g. for desalination
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
  • Y02A20/124—Water desalination
  • Y02A20/131—Reverse-osmosis

Definitions

• the present invention relates to a composite semipermeable membrane used for liquid filtration and the like.
• Membranes used for membrane separation of liquid mixtures include microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes. It is used to obtain water, to produce industrial ultrapure water, to treat wastewater, and to recover valuables.
• a composite semipermeable membrane is a membrane having a plurality of layers, and a particularly widely used composite semipermeable membrane consists of a microporous support layer and a polyfunctional aromatic amine and a polyfunctional aromatic acid halide. It has a separation functional layer containing a crosslinked aromatic polyamide obtained by a condensation reaction.
• These composite semipermeable membranes are required to have high salt removal properties in order to improve the quality of water obtained when used.
• Patent Documents 1 and 2 As a means for improving the salt-removing property of the membrane, for example, a post-treatment method (Patent Documents 1 and 2) is known in which the amine terminal of the crosslinked aromatic polyamide is converted by contacting with a diazo coupling reaction or an aqueous free chlorine solution containing bromine. It is
• an object of the present invention is to provide a composite semipermeable membrane which is improved in salt removal while maintaining water permeability.
• the present invention has any one of the following configurations [1] to [8].
• [1] A composite semipermeable membrane having a microporous support layer and a separation function layer provided on the microporous support layer, wherein the separation function layer is a portion represented by the following formula (1)
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 1 represents a structure represented by any one of formulas (2) to (4) below.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• L 1 in the above formulas (10) to (12) is a single bond, The method for producing the composite semipermeable membrane according to [6].
• the aliphatic carboxylic acid containing an amino group is at least one compound selected from proline, sarcosine, 2-aminoisobutyric acid, and threonine; A method for producing a composite semipermeable membrane according to [6] or [7].
• the composite semipermeable membrane of the present invention exhibits high salt removal and practical water permeability.
• the composite semipermeable membrane according to this embodiment has a microporous support layer and a separation function layer provided on the microporous support layer.
• a composite semipermeable membrane according to one aspect of the present invention comprises a support membrane including a substrate and a microporous support layer, and a separation functional layer formed on the microporous support layer.
• the separation function layer has substantially separation performance, and the supporting membrane is permeable to water but substantially does not have separation performance for ions and the like, and can give strength to the separation function layer.
• the composite semipermeable membrane according to the present embodiment may have a microporous support layer and a separation function layer, and the microporous support layer is a layer that constitutes the support membrane.
• the support membrane comprises a substrate and a microporous support layer.
• the present invention is not limited to this configuration.
• the support membrane may be composed of only a microporous support layer without a substrate.
• Substrate Substrates include polyester-based polymers, polyamide-based polymers, polyolefin-based polymers, and mixtures or copolymers thereof. Among them, polyester-based polymer fabric having high mechanical and thermal stability is particularly preferable. As the form of the fabric, a long-fiber nonwoven fabric, a short-fiber nonwoven fabric, and a woven or knitted fabric can be preferably used.
• the microporous support layer does not substantially have the ability to separate ions and the like, and has a function to give strength to the separation functional layer that has substantially the ability to separate ions. It is.
• the size and distribution of pores in the microporous support layer are not particularly limited.
• the microporous support layer has, for example, uniform fine pores, or gradually large fine pores from the surface on which the separation functional layer is formed to the other surface, and the surface on which the separation functional layer is formed.
• a microporous support layer having a surface pore size of 0.1 nm or more and 100 nm or less is preferred.
• the material used for the microporous support layer and its shape are not particularly limited.
• microporous support layer examples include homopolymers or copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulosic polymer, vinyl polymer, polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfone, and polyphenylene oxide. They can be used alone or mixed. Cellulose-based polymers such as cellulose acetate and cellulose nitrate, and vinyl polymers such as polyethylene, polypropylene, polyvinyl chloride and polyacrylonitrile can be used.
• homopolymers or copolymers such as polysulfone, polyamide, polyester, cellulose acetate, cellulose nitrate, polyvinyl chloride, polyacrylonitrile, polyphenylene sulfide, and polyphenylene sulfide sulfone are preferred, and cellulose acetate is more preferred as the material for the microporous support layer.
• polysulfone, polyphenylene sulfide sulfone, or polyphenylene sulfone are particularly preferable as a material for the microporous support layer because it has high chemical, mechanical and thermal stability and is easy to mold.
• Polysulfone preferably has a weight average molecular weight (Mw) of 10,000 or more and 200,000 or less, more preferably 10,000 or more and 200,000 or less, when measured by gel permeation chromatography (GPC) using N-methylpyrrolidone as a solvent and polystyrene as a standard substance. It is 15000 or more and 100000 or less.
• Mw weight average molecular weight
• GPC gel permeation chromatography
• the Mw of polysulfone is 10,000 or more, it is possible to obtain mechanical strength and heat resistance preferable for the microporous support layer. Further, when the Mw is 200,000 or less, the viscosity of the solution is in an appropriate range, and good moldability can be achieved.
• a solution of polysulfone in N,N-dimethylformamide (hereinafter referred to as DMF) is applied to a uniform thickness on a tightly woven polyester or non-woven fabric. Cast and wet solidify it in water. According to this method, it is possible to obtain a microporous support layer having fine pores with a diameter of several tens of nanometers or less on most of the surface.
• the thickness of the base material and microporous support layer affects the strength of the composite semipermeable membrane and the packing density when it is used as an element.
• the total thickness of the substrate and the microporous support layer is preferably 30 ⁇ m or more and 300 ⁇ m or less, more preferably 100 ⁇ m or more and 220 ⁇ m or less.
• the thickness of the microporous support layer is preferably 20 ⁇ m or more and 100 ⁇ m or less, and more preferably 25 ⁇ m or more and 50 ⁇ m or less. more preferred.
• the thickness means an average value.
• the average value represents an arithmetic mean value. That is, the thickness of the substrate and the microporous support layer is obtained by calculating the average value of the thickness of 20 points measured at intervals of 20 ⁇ m in the direction perpendicular to the thickness direction (surface direction of the membrane) by cross-sectional observation.
• the separation functional layer contains a crosslinked aromatic polyamide.
• the separation functional layer preferably contains a crosslinked aromatic polyamide as a main component.
• the main component refers to a component that accounts for 50% by mass or more of the components of the separation functional layer.
• the separation functional layer contains 50% by mass or more of the crosslinked aromatic polyamide, high salt removal performance can be exhibited.
• the content of the crosslinked aromatic polyamide in the separation functional layer is more preferably 80% by mass or more, and even more preferably 90% by mass or more.
• the crosslinked aromatic polyamide has a partial structure represented by the following formula (1) due to amide bonds via its terminal amino groups.
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 1 represents a structure represented by any one of formulas (2) to (4) below.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• Ar 1 to Ar 3 in the above formula (1) are preferably benzene rings which may have a substituent from the viewpoint of securing an appropriate free volume through which water permeates in the separation functional layer.
• substituents that the benzene ring may have include an amino group, a carboxy group, and a methyl group, but substituents other than these may also be employed. Also, the benzene ring may be unsubstituted.
• R 2 to R 5 in the above formula (1) are preferably hydrogen atoms from the viewpoint of forming hydrogen bonds between the crosslinked aromatic polyamides constituting the separation functional layer and contributing to improvement of selective permeability. .
• L 1 in the above formulas (2) to (4) is preferably a single bond from the viewpoint of suppressing a decrease in hydrophilicity of the crosslinked aromatic polyamide constituting the separation functional layer.
• W 3 in the above formulas (2) to (4) is preferably an aliphatic chain having 1 to 6 carbon atoms which may contain a hetero atom or a branch. .
• the crosslinked aromatic polyamide preferably contains a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride as monomer components. That is, it is preferably a polycondensate of a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride. Specific examples of polyfunctional aromatic amines and polyfunctional aromatic acid chlorides are described in the section on production methods.
• R 1 contains an amino group in its structure.
• the hydrogen atoms contained in the above amino groups are hydrogen bond donors, and have a high affinity with hydrogen bond acceptors such as carbonyl groups in the crosslinked aromatic polyamide and oxygen atoms in the permeated water. Contributes to the formation of hydrogen bonds. This increases the water permeability of the separation functional layer containing the crosslinked aromatic polyamide.
• the separation functional layer containing the crosslinked aromatic polyamide there is concern about clogging of pores, which are passages of permeated water.
• the amino group in the structure of R 1 in the above formula (1) is a secondary amino group, or a primary amino group such that the carbon atom adjacent to the amino group is a tertiary carbon or a quaternary carbon.
• the amino group in the structure of R 1 in the above formula (1) is more preferably a secondary amino group.
• W 3 in the structure of R 1 in the above formula (1) is preferably an aliphatic chain having 1 to 6 carbon atoms which may contain heteroatoms or branches.
• W 1 to W 3 in the above formulas (2) to (4) contain a carbonyl group. do not have.
• R 1 in the above formula (1) includes the following formulas (5) to (8).
• R 1 in the above formula (1) is preferably represented by any one of the following formulas (5) to (8) from the viewpoint of formation of continuous hydrogen bonds.
• the ratio of (molar equivalent of amino group + molar equivalent of carboxy group)/(molar equivalent of amide group) measured by DD-MAS- 13 C solid-state NMR method is 0.56 or less. is preferred.
• the polyamide in the separation functional layer forms a dense network structure, improving the salt removal rate.
• the ratio is more preferably 0.50 or less, still more preferably 0.45 or less, and particularly preferably 0.42 or less. From the viewpoint of ensuring water-permeable channels in the separation functional layer, the ratio is preferably 0.30 or more, more preferably 0.35 or more.
• polycondensation of polyfunctional aromatic amine and polyfunctional aromatic acid chloride there is a method of drying after drying, and a method of polymerizing using a high-concentration polyfunctional aromatic amine aqueous solution and a high-concentration polyfunctional aromatic acid chloride solution in the polymerization step.
• the amount of functional groups in the separation functional layer can be measured using the DD-MAS- 13 C solid-state NMR method by the following procedure.
• the substrate is first peeled off to obtain the separation functional layer and the microporous support layer, and then the microporous support layer is dissolved and removed to obtain the separation functional layer.
• the obtained separation function layer was measured by DD/MAS- 13 C solid-state NMR method, and the amount ratio of each functional group was calculated by comparing the carbon peak of each functional group or the integrated value of the carbon peak to which each functional group is bonded. can be calculated.
• CMX-300 manufactured by Chemagnetics
• Method for producing a composite semipermeable membrane includes the polymerization step and modification step described below.
• Polymerization step step of forming a crosslinked aromatic polyamide-containing layer
• the polymerization step is a step of forming a layer containing a crosslinked aromatic polyamide having a partial structure of the following formula (9) on the microporous support layer. is.
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• Preferred embodiments of the groups represented by Ar 1 to Ar 3 and R 2 to R 5 in formula (9) are the same as in formula (1).
• the polymerization step is a step of forming a crosslinked aromatic polyamide by polycondensing a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride, and more specifically, a polyfunctional aromatic amine (hereinafter simply referred to as a polyfunctional aromatic amine aqueous solution) on the microporous support layer, and thereafter, an organic solvent containing a polyfunctional aromatic acid chloride on the microporous support layer and contacting with a solution (hereinafter also simply referred to as a polyfunctional aromatic acid chloride solution).
• a polyfunctional aromatic amine hereinafter simply referred to as a polyfunctional aromatic amine aqueous solution
• At least one of the polyfunctional aromatic amine and the polyfunctional aromatic acid chloride is preferably trifunctional or higher. This results in a rigid molecular chain and a good pore structure for removing fine solutes such as hydrated ions and boron.
• a polyfunctional aromatic amine has two or more amino groups of at least one of a primary amino group and a secondary amino group in one molecule, and at least one of the amino groups is a primary It is an aromatic amine that is an amino group.
• Polyfunctional aromatic amines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, o-diaminopyridine and m-diaminopyridine.
• p-diaminopyridine compounds having two amino groups bonded to an aromatic ring in either the ortho-, meta- or para-position, and 1,3,5-triaminobenzene, 1, Examples include 2,4-triaminobenzene, 3,5-diaminobenzoic acid, 3-aminobenzylamine, 4-aminobenzylamine and the like.
• One type of these polyfunctional aromatic amines may be used, or a plurality of types may be used in combination.
• at least one compound selected from m-phenylenediamine, p-phenylenediamine and 1,3,5-triaminobenzene is often used in terms of obtaining a membrane excellent in selective separation, permeability and heat resistance. It is preferably used as a functional aromatic amine.
• m-phenylenediamine is preferable because of its availability and ease of handling.
• a polyfunctional aromatic acid chloride is an aromatic acid chloride having at least two chlorocarbonyl groups in one molecule.
• trifunctional acid chlorides include trimesic acid chloride
• bifunctional acid chlorides include biphenyldicarboxylic acid dichloride, azobenzenedicarboxylic acid dichloride, terephthalic acid chloride, isophthalic acid chloride, and naphthalenedicarboxylic acid chloride.
• One type of these polyfunctional aromatic acid chlorides may be used, or a plurality of types may be used in combination.
• polyfunctional aromatic acid chlorides having 2 to 4 carbonyl chloride groups in one molecule are preferred, and trimesic acid chloride is more preferred, in that a membrane excellent in selective separation, permeability and heat resistance can be obtained. preferable.
• polyfunctional aromatic amine and polyfunctional aromatic acid chloride are preferably m-phenylenediamine and trimesic acid chloride, respectively.
• the concentration of the polyfunctional aromatic amine in the polyfunctional aromatic amine aqueous solution is preferably in the range of 0.1% by mass or more and 20% by mass or less, more preferably in the range of 0.5% by mass or more and 15% by mass or less. is. If the concentration of the polyfunctional aromatic amine is within this range, sufficient salt removal performance and water permeability can be obtained.
• the contact of the polyfunctional aromatic amine aqueous solution with the microporous support layer is preferably carried out uniformly and continuously on the microporous support layer.
• a method of coating the microporous support layer with an aqueous polyfunctional aromatic amine solution, a method of immersing the microporous support layer in an aqueous polyfunctional aromatic amine solution, and the like can be mentioned.
• the contact time between the microporous support layer and the polyfunctional aromatic amine aqueous solution is preferably from 1 second to 10 minutes, more preferably from 10 seconds to 3 minutes.
• the support film after contact with the polyfunctional aromatic amine aqueous solution is held in the vertical direction and the excess aqueous solution is allowed to flow naturally, or an air flow such as nitrogen is blown from an air nozzle to forcibly drain. and the like can be used.
• the film surface can be dried to partially remove water from the aqueous solution.
• the concentration of the polyfunctional aromatic acid chloride in the polyfunctional aromatic acid chloride solution is preferably in the range of 0.01% by mass or more and 10% by mass or less, and 0.02% by mass or more and 2.0% by mass or less. It is more preferable that it is within the range.
• a sufficient reaction rate can be obtained by setting the concentration of the polyfunctional aromatic acid chloride to 0.01% by mass or more, and side reactions can be suppressed by setting the concentration to 10% by mass or less.
• the organic solvent in the polyfunctional aromatic acid chloride solution is preferably one that is immiscible with water, dissolves the polyfunctional aromatic acid chloride, and does not destroy the support film. Any substance can be used as long as it is inert to acid chloride.
• Preferred examples of organic solvents include hydrocarbon compounds and mixed solvents such as n-nonane, n-decane, n-undecane, n-dodecane, isooctane, isodecane and isododecane.
• the contact of the polyfunctional aromatic acid chloride solution with the microporous support layer may be carried out in the same manner as the method of coating the microporous support layer with the polyfunctional aromatic amine aqueous solution.
• the membrane After bringing the polyfunctional aromatic acid chloride solution into contact with the microporous support layer, the membrane may be dried. By carrying out the drying, it is possible to adjust the ratio of (molar equivalent of amino group + molar equivalent of carboxy group)/(molar equivalent of amide group) of the separation functional layer.
• the drying method is not particularly limited, it can be carried out using, for example, an oven, a heat gun, a hot air generator, or the like.
• the temperature during drying that is, the temperature during polycondensation of polyfunctional amino and polyfunctional aromatic acid chloride, is (molar equivalent of amino group + molar equivalent of carboxy group) / (molar equivalent of amide group) of the separation functional layer. is preferably in the range of 50 to 100°C, more preferably in the range of 60 to 90°C, and even more preferably in the range of 65 to 90°C.
• the dried film may be drained in the same manner as the polyfunctional aromatic amine aqueous solution in order to remove excess solution remaining on the film surface.
• a mixed fluid of water and air can be used in addition to the method mentioned for the polyfunctional aromatic amine aqueous solution.
• Unreacted monomers can be removed by washing the film thus obtained with hot water.
• the temperature of the hot water is preferably 40°C or higher and 100°C or lower, more preferably 60°C or higher and 100°C or lower.
• the crosslinked aromatic polyamide-containing layer has a separation function even before the modification step described later, this layer is sometimes referred to as a separation functional layer, and the substrate, the microporous support layer and the crosslinked aromatic polyamide-containing A composite membrane having layers is sometimes referred to as a composite semipermeable membrane.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• L 1 in formulas (10) to (12) is preferably a single bond from the viewpoint of suppressing a decrease in hydrophilicity of the crosslinked aromatic polyamide constituting the separation functional layer.
• Preferred embodiments of the groups represented by W 1 to W 3 in formulas (10) to (12) are the same as in formula (1).
• the compounds represented by formulas (10) to (12) are aliphatic carboxylic acids containing amino groups.
• Specific examples of aliphatic carboxylic acids containing amino groups include sarcosine, glycocyamine, N-methylalanine, N-ethylglycine, proline, azetidine-2-carboxylic acid, hydroxyproline, 3,4-dehydroproline, homoproline, and serine. , threonine, allothreonine, lysine, arginine, cysteine, 2-aminoisobutyric acid, 2-aminobutyric acid, valine, leucine, isoleucine, methionine, glucosamic acid and the like.
• the aliphatic carboxylic acid containing an amino group is preferably at least one of proline, sarcosine, 2-aminoisobutyric acid, and threonine, from the viewpoint of continuous hydrogen bond formation.
• an aliphatic carboxylic acid containing an amino group represented by any one of the formulas (10) to (12) (hereinafter referred to as "amino group-containing aliphatic carboxylic acid") is added to the crosslinked aromatic polyamide represented by the above formula (9).
• the separation function layer of the composite semipermeable membrane may be reacted by coating an amino group-containing aliphatic carboxylic acid, or an amino group-containing aliphatic carboxylic acid
• the composite semipermeable membrane containing the separation function layer may be immersed in a solution containing it to react.
• the solution containing the amino group-containing aliphatic carboxylic acid may be passed through and reacted.
• the reaction time, temperature and concentration when the amino group-containing aliphatic carboxylic acid is applied to the composite semipermeable membrane as an aqueous solution or as it is can be appropriately adjusted depending on the type of amino group-containing aliphatic carboxylic acid and the application method. .
• the concentration of the amino group-containing aliphatic carboxylic acid is 0.1 mmol/L
• the reaction time is preferably 30 minutes or longer and the reaction temperature is preferably 10° C. or higher.
• a solution containing the amino group-containing aliphatic carboxylic acid may be used, or a solvent-free liquid of the amino group-containing aliphatic carboxylic acid may be used.
• the solvent can be changed according to the type of amino group-containing aliphatic carboxylic acid, and water or isopropanol is exemplified.
• condensation accelerators include sulfuric acid, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (hereinafter referred to as DMT-MM), 1-(3 -dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-carbonyldiimidazole, 1,1'-carbonyldi(1,2, 4-triazole), 1H-benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate, 1H-benzotriazol-1-yloxytris(
• the method for producing the composite semipermeable membrane may include a step of forming a microporous support layer on the base material before the step of forming the separation function layer, to form a composite semipermeable membrane. Moreover, various post-treatments may be performed after the separation functional layer is formed.
• a composite semipermeable membrane consists of a feed water channel material such as a plastic net, a permeate water channel material such as tricot, a film to increase pressure resistance as necessary, and a cylindrical water collecting pipe with many holes. and is suitably used as a spiral-type composite semipermeable membrane element. Furthermore, a composite semipermeable membrane module in which these elements are connected in series or in parallel and housed in a pressure vessel can also be formed.
• the above composite semipermeable membranes, their elements, and modules can be combined with a pump that supplies water to them, a device that preprocesses the water, and the like to form a fluid separation device.
• a separator By using this separator, it is possible to separate feed water into permeated water such as drinking water and concentrated water that has not permeated the membrane, thereby obtaining desired water.
• feed water treated by the composite semipermeable membrane examples include liquid mixtures containing 500 mg/L or more and 100 g/L or less of TDS (Total Dissolved Solids) such as seawater, brackish water, and waste water.
• TDS Total Dissolved Solids
• mass/volume or weight ratio
• the operating pressure during permeation is preferably 0.5 MPa or more and 10 MPa or less.
• scale such as magnesium may be generated in the case of feed water with a high solute concentration such as seawater. Region operation is preferred.
• a composite semipermeable membrane containing a crosslinked aromatic polyamide containing structure
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 1 represents a structure represented by any one of formulas (2) to (4) below.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• the ratio of (molar equivalent of amino group + molar equivalent of carboxy group)/(molar equivalent of amide group) of the separation functional layer measured by DD-MAS- 13 C solid-state NMR method is 0.56 or less.
• L 1 in the above formulas (2) to (4) is a single bond
• W 3 in the above formulas (2) to (4) is a heteroatom or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch
• R 1 in the above formula (1) is represented by any one of the following formulas (5) to (8), The composite semipermeable membrane according to any one of ⁇ 1> to ⁇ 4>.
• Ar 1 to Ar 3 are each independently an aromatic ring having 5 to 14 carbon atoms which may have a substituent.
• R 2 to R 5 are each independently a hydrogen atom or an aliphatic chain having 1 to 10 carbon atoms.
• L 1 is a single bond or an aliphatic chain of 1-6 carbon atoms.
• W 1 to W 3 are each independently a hydrogen atom, a heteroatom, or an aliphatic chain having 1 to 6 carbon atoms which may contain a branch, and at least one of W 1 to W 3 is hetero It is an aliphatic chain of 1-6 carbon atoms which may contain atoms or branches.
• W3 is a hydrogen atom
• the total number of carbon atoms of W1 and W2 is 2 or more and 12 or less.
• W 1 to W 3 do not contain a carbonyl group.
• L 1 in formulas (10) to (12) is a single bond
• the aliphatic carboxylic acid containing an amino group is at least one compound selected from proline, sarcosine, 2-aminoisobutyric acid, and threonine;
• composite semipermeable membrane may be used regardless of whether it is before or after the modification step.
• membrane permeation flux The membrane permeation flux (m 3 /m 2 /day) was determined from the daily water permeation rate (m 3 ) per square meter of the membrane surface obtained under the above conditions.
• the substrate was physically peeled off from 5 m 2 of the composite semipermeable membrane to recover the microporous support layer and the separation functional layer. After drying by standing still for 24 hours, the microporous support layer and separation function layer were added little by little into a beaker containing dichloromethane and stirred to dissolve the polymer constituting the microporous support layer. The insoluble matter in the beaker was collected with filter paper. This insoluble matter was placed in a beaker containing dichloromethane and stirred to collect the insoluble matter in the beaker.
• the recovered separation functional layer was dried in a vacuum dryer to remove residual dichloromethane.
• the obtained separation function layer was freeze-ground to form a powder sample, sealed in a sample tube used for solid-state NMR measurement, and measured by DD-MAS- 13 C solid-state NMR method.
• CMX-300 manufactured by Chemagnetics was used. Measurement conditions are shown below.
• Reference substance polydimethylsiloxane (internal standard: 1.56 ppm)
• Sample rotation speed 10.5 kHz
• Pulse repetition time 100s From the obtained spectrum, peak division was performed for each peak derived from the carbon atom to which each functional group is bonded, and the functional group amount ratio was quantified from the areas of the divided peaks.
• Comparative example 1 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of acetic acid and DMT-MM at 25° C. for 1 hour. A composite semipermeable membrane of Comparative Example 1 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Comparative example 2 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of glycine and DMT-MM at 25° C. for 1 hour. A composite semipermeable membrane of Comparative Example 2 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Comparative Example 3 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of N,N-dimethylglycine and DMT-MM at 25° C. for 1 hour. A composite semipermeable membrane of Comparative Example 3 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Comparative Example 4 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of acetulic acid and DMT-MM at 25° C. for 1 hour. A composite semipermeable membrane of Comparative Example 4 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 1 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of sarcosine and DMT-MM at 25° C. for 1 hour.
• the composite semipermeable membrane of Example 1 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 2 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of proline and DMT-MM at 25° C. for 1 hour.
• the composite semipermeable membrane of Example 2 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 3 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 100 mmol/L of threonine and DMT-MM at 25° C. for 1 hour.
• the composite semipermeable membrane of Example 3 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 4 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 2-aminoisobutyric acid and DMT-MM at a concentration of 100 mmol/L each at 25° C. for 1 hour.
• the composite semipermeable membrane of Example 4 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 5 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 2-aminobutyric acid and DMT-MM at a concentration of 100 mmol/L each at 25° C. for 1 hour.
• the composite semipermeable membrane of Example 5 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 6 The composite semipermeable membrane obtained in Reference Example 1 was immersed in a pH 8 aqueous solution containing 3-aminobutyric acid and DMT-MM at a concentration of 100 mmol/L each at 25° C. for 1 hour. A composite semipermeable membrane of Example 6 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Example 7 The composite semipermeable membrane obtained in Reference Example 2 was immersed in a pH 8 aqueous solution containing 100 mmol/L of sarcosine and DMT-MM at 25° C. for 1 hour. A composite semipermeable membrane of Example 7 was obtained by immersing the obtained composite semipermeable membrane in RO water.
• Examples 1 to 7 which are composite semipermeable membranes according to one embodiment of the present invention, have excellent salt removal properties while maintaining water permeability compared to Comparative Examples 1 to 4. Indicated.

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