Classifications

• • 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
  • B01D67/0083—Thermal after-treatment
• • 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
• • 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
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
  • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
  • C08G69/32—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/08—Specific temperatures applied
  • B01D2323/081—Heating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/30—Chemical resistance
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/43—Specific optical properties

Definitions

• the present invention relates to a composite semipermeable membrane useful for selective separation of liquid mixtures.
• the composite semipermeable membrane obtained by the present invention can be suitably used for desalination of brine or seawater.
• the membrane separation method is attracting attention as an energy-saving and resource-saving method for removing substances (for example, salts) dissolved in the solvent from the solvent (for example, water).
• Membranes used in the membrane separation method include microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and the like. These membranes are used, for example, in the production of drinking water from seawater, irrigation water, water containing harmful substances, the production of industrial ultrapure water, wastewater treatment and recovery of valuable resources.
• the composite semipermeable membrane includes a porous support layer and a separation functional layer provided on the porous support layer and containing a crosslinked polyamide obtained by a polycondensation reaction between a polyfunctional amine and a polyfunctional acid halide.
• the composite semipermeable membrane having is widely used as a separation membrane having high permeability and selective separation (for example, Patent Document 1).
• An object of the present invention is to provide a composite semipermeable membrane capable of suppressing deterioration of salt removal performance even when in contact with raw water having high oxidizing property.
• the present invention includes the following 1 to 7.
• 1. A composite semipermeable membrane having a microporous support layer and a separation functional layer provided on the microporous support layer.
• the separation functional layer contains a crosslinked total aromatic polyamide which is a polycondensate of a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride and contains an amino group and a carboxy group.
• trimesic acid and trimesic acid occupy a fraction of 90% by mass or more among the aromatic carboxylic acid and the aromatic carboxylic acid salt.
• the composite semipermeable membrane of the present invention it is possible to suppress a decrease in the salt removal rate even when it comes into contact with raw water having extremely high oxidizing properties.
• the composite translucent film according to the embodiment of the present invention is a composite translucent film having a microporous support layer and a separation functional layer provided on the microporous support layer, and the separation functional layer is a composite semitransparent film. It is a polycondensate of a polyfunctional aromatic amine and a polyfunctional aromatic acid chloride, and contains a crosslinked total aromatic polyamide containing an amino group and a carboxy group.
• the composite semipermeable membrane according to the embodiment of the present invention is, for example, a support membrane including a base material and a microporous support layer formed on the base material, and a separation formed on the microporous support layer. It has a functional layer.
• the separation functional layer has substantially separation performance.
• the support film does not substantially have the separation performance of ions and the like, and can impart strength to the separation functional layer.
• Base material examples include polyester-based polymers, polyamide-based polymers, polyolefin-based polymers, mixtures thereof, copolymers, and the like. Of these, a polyester-based polymer fabric having high mechanical and thermal stability is particularly preferable.
• the thickness of the base material is preferably in the range of 10 to 200 ⁇ m, more preferably in the range of 30 to 120 ⁇ m.
• the thickness is an arithmetic mean value unless otherwise specified. That is, the thickness of the base material and the microporous support layer can be obtained by calculating the average value of the thicknesses of 20 points measured at intervals of 20 ⁇ m in the direction orthogonal to the thickness direction (plane direction of the film) in the cross-sectional observation.
• the microporous support layer is intended to give strength to a separation functional layer having substantially no separation performance such as ions and substantially having separation performance.
• the size and distribution of the pores of the microporous support layer are not particularly limited, but for example, they have uniform and fine pores or fine pores that gradually increase from the surface on the side where the separation function layer is formed to the other surface.
• a microporous support layer having a fine pore size (average pore diameter) of 0.1 nm or more and 100 nm or less on the surface on the side where the separation functional layer is formed is preferable.
• Examples of the material constituting the microporous support layer include homopolymers or copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulose-based polymer, vinyl polymer, polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfone, and polyphenylene oxide. It can be used alone or in combination of two or more.
• the cellulosic polymer cellulose acetate, cellulose nitrate and the like can be used
• vinyl polymer polyethylene, polypropylene, polyvinyl chloride, polyacrylonitrile and the like 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. More preferably, cellulose acetate, polysulfone, polyphenylene sulfide sulfone, or polyphenylene sulfide can be mentioned, and among these materials, polysulfone has high chemical, mechanical, and thermal stability and is easy to mold. Can be used in general. Specifically, it is preferable to use polysulfone composed of repeating units shown in the following chemical formula because the pore size of the microporous support layer can be easily controlled and the dimensional stability is high.
• the thickness of the base material and the 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, and 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.
• the thickness of the base material and the microporous support layer is obtained by calculating the average value of the thicknesses of 20 points measured at intervals of 20 ⁇ m in the direction orthogonal to the thickness direction (plane direction of the film) in the cross-sectional observation.
• the separation functional layer contains a crosslinked total aromatic polyamide.
• the separation functional layer preferably contains crosslinked total aromatic polyamide as a main component.
• the main component refers to a component that occupies 50% by weight or more of the components of the separation functional layer.
• the separation functional layer can exhibit high removal performance by containing 50% by weight or more of the crosslinked total aromatic polyamide.
• it is preferable that the separation functional layer is formed substantially only of the crosslinked total aromatic polyamide.
• the fact that the separation functional layer is formed substantially only of the crosslinked total aromatic polyamide means that the crosslinked total aromatic polyamide occupies 90% by weight or more of the separation functional layer.
• the crosslinked total aromatic polyamide can be formed by intercondensation polycondensation of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide.
• a polyfunctional aromatic amine and a polyfunctional aromatic acid halide contains a trifunctional or higher functional compound.
• the separation functional layer in the present invention may be hereinafter referred to as a polyamide separation functional layer.
• the polyfunctional aromatic amine has two or more amino groups 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 primary. It means an aromatic amine which is an amino group.
• examples of the polyfunctional aromatic amine include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-xylylene diamine, m-xylylene diamine, p-xylylene diamine, o-diaminopyridine, and m-.
• m-phenylenediamine, p-phenylenediamine, and 1,3,5-triaminobenzene are preferably used in consideration of selective separability, permeability, and heat resistance of the membrane. Above all, it is more preferable to use m-phenylenediamine (hereinafter, also referred to as m-PDA) from the viewpoint of easy availability and handling.
• m-phenylenediamine hereinafter, also referred to as m-PDA
• These polyfunctional aromatic amines may
• the polyfunctional aromatic acid halide refers to an aromatic acid halide having at least two halogenated carbonyl groups in one molecule.
• the trifunctional acid halide includes trimesic acid chloride and the like
• the bifunctional acid halide includes biphenyldicarboxylic acid dichloride, azobenzenedicarboxylic acid dichloride, terephthalic acid chloride, isophthalic acid chloride, naphthalenedicarboxylic acid chloride and the like. Can be mentioned.
• the polyfunctional aromatic acid chloride is preferable as a polyfunctional aromatic acid halide because it has excellent reactivity with the polyfunctional aromatic amine. Further, when the polyfunctional aromatic acid halide is a polyfunctional aromatic acid chloride having 2 to 4 carbonyl chloride groups in one molecule, a film having excellent selective separability and heat resistance can be obtained.
• the polyfunctional aromatic acid halide it is preferable to use two or more kinds of compounds for controlling the amount of functional groups by the sequential reaction described later, and further, the compound having a fast reaction rate with the polyfunctional aromatic amine and the compound having a slow reaction rate are slow. It is preferable to use a mixture of compounds.
• a polyfunctional aromatic acid halide When a polyfunctional aromatic acid halide is mixed and used, it is preferable to use a trifunctional aromatic acid halide as a main component.
• the trifunctional aromatic acid halide can crosslink the polyamide.
• the trifunctional aromatic acid halide is preferably trimesic acid chloride, and the proportion of trimesic acid chloride in the total amount of the polyfunctional aromatic acid halide used is 90% by mass or more. preferable.
• the polyamide separation functional layer contains an amide group derived from the polymerization of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide, and an amino group and a carboxy group derived from an unreacted functional group.
• the amino group on the surface of the film is the starting point of oxidative deterioration of the film, it is preferable to reduce the amount thereof in order to improve the durability.
• the carboxy group on the film surface has high hydrophilicity and chargeability, it is preferable to increase the amount from the viewpoint of improving the salt removal rate and the amount of water produced.
• the ratio of the count number) is a, and a is 5.0 or more, preferably 7.0 or more. That is, a ⁇ 5.0, and a ⁇ 7.0 is preferable.
• the ratio of the above-mentioned value a to b is a / b ⁇ , where b is the molar ratio (carboxy group / amino group) of the carboxy group and the amino group obtained by analyzing the entire separation functional layer by 13 C solid-state NMR. It is 4.3, and it is preferable that a / b ⁇ 5.5.
• the amount of surface amino groups is represented by the degree of yellowing ( ⁇ YI) before and after vanillin yellowing obtained by the following method. It is preferable that the degree of yellowing satisfies the range of 2 or more and 20 or less from the viewpoint of improving the oxidation resistance.
• the composite semipermeable membrane is immersed in a vanillin / ethanol (mass ratio 2/98) solution for 15 seconds.
• the composite semipermeable membrane after immersion is air-dried for 1 hour, ethanol is removed, and then a dry heat treatment is performed at 150 ° C. for 15 minutes.
• the constituent elements of the separation functional layer detected by the combustion method are substantially only hydrogen, carbon, nitrogen and oxygen.
• the fact that the constituent elements of the separation functional layer detected by the combustion method are substantially only hydrogen, carbon, nitrogen and oxygen means that the elements other than the above detected as the constituent elements of the separation functional layer are 1% or less. That means. It is preferable that the constituent elements of the separation functional layer are substantially only hydrogen, carbon, nitrogen and oxygen because it is a sufficient condition that the separation functional layer is not significantly halogenated or contaminated.
• the microporous support layer of the composite semipermeable membrane is dissolved using an organic solvent such as methylene chloride, thoroughly washed, and then simply.
• An example is a method of analyzing the separated functional layer using an elemental analyzer by a combustion method.
• the separation functional layer is decomposed into one or more kinds of aromatic amines and two or more kinds of aromatic carboxylic acids or aromatic carboxylic acid salts by alkaline hydrolysis.
• Alkaline hydrolysis means that the amide group of the separation functional layer is cleaved and decomposed into a monomer-derived amine and a carboxylic acid.
• the microporous support layer of the composite semipermeable membrane is dissolved with an organic solvent such as methylene chloride, thoroughly washed, and then the isolated functional layer is solidified in a high-concentration, high-temperature sodium hydroxide aqueous solution.
• the separation functional layer can be alkaline hydrolyzed by retaining the component until it dissolves.
• trimesic acid and trimesic acid salts occupy a fraction of 90% by mass or more.
• the method for producing a composite semipermeable membrane includes a step of forming a microporous support layer on a substrate and a step of forming a separation functional layer on the microporous support layer.
• a microporous support layer is obtained by dissolving the resin in a good solvent, applying this solution on a substrate, and immersing it in a coagulation bath. Can be formed.
• a solution of polysulfone N, N-dimethylformamide hereinafter referred to as DMF
• DMF polysulfone N, N-dimethylformamide
• the step of forming the separation functional layer is a step of forming a layer of polyamide by interfacial polycondensation of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide, and includes the following steps (A) to (C). ..
• A) The microporous support layer is impregnated with an aqueous solution containing a polyfunctional aromatic amine.
• C Reacting the above polyfunctional aromatic amine with a polyfunctional aromatic acid halide.
• Step (C) proceeds after (B) until washing.
• the time and temperature of step (C) can be changed according to the type of monomer used, the characteristics required for the film, and the like.
• the temperature may be room temperature or 30 ° C. or higher by heating. Further, the temperature may be changed in the step (C). Further, the steps (B) and (C) may have the following variations.
• step (B) an organic solvent solution containing two or more kinds of polyfunctional aromatic acid halides having different reaction rates with amino groups contained in the above polyfunctional aromatic amine can be applied.
• the polyfunctional aromatic acid halide having a high reaction rate first reacts to form a layer of polyamide.
• the polyfunctional aromatic acid halide with a high reaction rate is consumed and its concentration decreases, the polyfunctional aromatic acid halide with a low reaction rate reacts with the amino groups present on the surface of the polyamide layer.
• the amount of amino groups on the surface decreases.
• the step (C) includes the first step having a low temperature and the second step having a high temperature, the reaction rate is low in the second step.
• the reaction of the functional aromatic acid halide may be promoted.
• Steps (B) and (C) may be repeated two or more times after step (A), and in each step (B) at this time, a solution containing the same kind of polyfunctional aromatic acid halide is used. It may be used, or a solution containing a polyfunctional aromatic acid halide having a lower reaction rate than the first step may be used in the second and subsequent steps.
• the concentration of the polyfunctional aromatic acid halide is made higher in the second and subsequent steps than in the first step.
• the concentration of the polyfunctional aromatic acid halide is set to 1.5 times or more that of the first step.
• step (C) which is performed after applying the solution containing the polyfunctional aromatic acid halide having a low reaction rate
• the temperature may be raised over the whole or in the middle thereof. This allows the polyamide layer to be formed first, followed by the polyfunctional aromatic acid halide to react with the amino groups on its surface.
• step (C) the temperature of the front surface (the surface on the microporous support layer side) may be higher than the temperature on the back surface (the surface on the substrate side) of the support film.
• the reaction of the polyfunctional aromatic acid halide on the amino group on the surface of the polyamide layer can be promoted.
• Specific methods for forming such a temperature gradient include heating the surface of the support film. Further, the temperature rise on the back surface may be suppressed by heating the front surface of the support film and blowing air to the back surface at the same time. The formation of such a temperature gradient may be applied to any of the above (1) and (2).
• a mixture of two or more kinds of polyfunctional aromatic acid halides having different reaction rates may be applied in step (B) to form a temperature gradient from the beginning or in the middle of step (C).
• polyfunctional aromatic acid halides having different reaction rates are applied stepwise, and the temperature gradient is increased over the entire reaction time after the application of the polyfunctional acid halides having a low reaction rate, or a part thereof. It may be formed.
• the amount of amino groups on the surface of the layer is reduced, and as a result, the above-mentioned functional group ratio between the surface and the inside is realized.
• the concentration of the polyfunctional aromatic amine in the aqueous solution of the polyfunctional aromatic amine is preferably in the range of 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 15%. It is within the range of mass% or less. When the concentration of the polyfunctional aromatic amine is in this range, sufficient solute removal performance and water permeability can be obtained.
• the polyfunctional aromatic amine aqueous solution contains a surfactant, an organic solvent, an alkaline compound, an antioxidant and the like as long as it does not interfere with the reaction between the polyfunctional aromatic amine and the polyfunctional aromatic acid halide. May be.
• the surfactant has the effect of improving the wettability of the surface of the support film and reducing the interfacial tension between the aqueous polyfunctional aromatic amine solution and the non-protic solvent.
• the aqueous solution of the polyfunctional aromatic amine may be applied to the microporous support layer, or the support film may be immersed in the aqueous solution of the polyfunctional aromatic amine.
• the contact time between the microporous support layer and the aqueous solution of the polyfunctional aromatic amine is preferably 1 second or more and 10 minutes or less, and more preferably 10 seconds or more and 3 minutes or less.
• the film surface can be dried to partially remove the water content of the aqueous solution.
• the concentration of the polyfunctional aromatic acid halide in the organic solvent 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. It is more preferably in the range of% or less. This is because a sufficient reaction rate can be obtained by setting the concentration to 0.01% by mass or more, and the occurrence of side reactions can be suppressed by setting the concentration to 10% by mass or less.
• This concentration range applies to all steps if step (B) comprises a plurality of steps.
• the organic solvent solution contains a plurality of types of polyfunctional aromatic acid halides, the total concentration thereof is preferably in this range.
• polyfunctional aromatic acid halides having a relatively high reaction rate examples include trimesic acid chloride (TMC), and examples of relatively low acid halides include isophthalic acid chlorides, terephthalic acid chlorides, and 1,3-benzenedi. Examples thereof include sulfonyl chlorides, 2,4-mesitylene sulfonyl dichlorides and 2,4,5,6-tetramethylbenzene disulfonyl dichlorides.
• the organic solvent is preferably immiscible with water, dissolves polyfunctional aromatic acid halides, and does not destroy the support film, and is inactive against polyfunctional amine compounds and polyfunctional aromatic acid halides. Anything that is can be used.
• Preferred examples include hydrocarbon compounds such as n-hexane, n-octane, n-decane and isooctane.
• infrared irradiation hot air, hot steam, or a combination of these means may be used.
• the temperature and reaction time in heating can be changed depending on the compound used.
• the maximum temperature for heat treatment is preferably 50 ° C. or higher and 180 ° C. or lower, more preferably 60 ° C. or higher and 160 ° C. or lower.
• the optimum heating time varies depending on the temperature of the membrane surface which is the reaction field, but is preferably 10 seconds or longer, more preferably 20 seconds or longer.
• the composite semipermeable membrane according to the embodiment of the present invention includes, for example, a supply water flow path material such as a plastic net and a permeation water flow path material such as a tricot, in order to increase the pressure resistance as necessary. Along with the film, it is wound around a cylindrical water collecting pipe having a large number of holes, and is suitably used as a spiral type composite semipermeable membrane element. Further, the elements can be connected in series or in parallel to form a composite semipermeable membrane module housed in a pressure vessel.
• the above-mentioned composite semipermeable membrane, its elements, and modules can be combined with a pump that supplies water to them, a device that pretreats the supplied water, and the like to form a fluid separation device.
• a separation device By using such a separation device, the supplied water can be separated into permeated water such as drinking water and concentrated water that has not permeated the membrane, and water suitable for the purpose can be obtained.
• the supply water treated by the composite semipermeable membrane according to the embodiment of the present invention contains TDS (Total Dissolved Solids) of 500 mg / L or more and 100 g / L or less such as seawater, irrigation water, and wastewater. Examples include liquid mixtures.
• TDS refers to the total amount of dissolved solids and is expressed as "mass / volume” or "weight ratio (mass ratio)".
• mass ratio mass ratio
• TDS can be calculated from the weight of the residue by evaporating a solution filtered through a 0.45 micron filter at a temperature of 39.5 ° C or higher and 40.5 ° C or lower, but more simply the practical salt content (practical salt content). Convert from S).
• the operating pressure when the water to be treated is permeated through the composite semipermeable membrane is preferably 0.5 MPa or more and 10 MPa or less.
• the temperature of the supply water is preferably 5 ° C. or higher because the membrane permeation flux decreases as the temperature becomes lower. Since the solute removal rate decreases as the temperature rises, the supply water temperature is preferably 55 ° C. or lower.
• the composite translucent film was dried at room temperature under vacuum, and a flight time type secondary ion mass spectrometry measurement was performed using a TOF SIMS 5 device (manufactured by ION TOF) (secondary ion polarity: positive, mass range (secondary ion polarity: positive, mass range).
• the substrate was physically peeled off from the composite semipermeable membrane 5 m 2 , and the microporous support layer and the separation functional layer were recovered. After allowing to stand for 24 hours to dry, a small amount was added to 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 recover the insoluble matter in the beaker. This process was repeated until the elution of the polymer forming the microporous support layer in the dichloromethane solution could not be detected.
• the recovered separation functional layer was dried in a vacuum dryer to remove residual dichloromethane.
• the obtained separation functional layer was made into a powdery sample by freeze-grinding, sealed in a sample tube used for solid-state NMR measurement, and 13 C solid-state NMR measurement was performed by CP / MAS method and DD / MAS method. 13 For C solid-state NMR measurement, for example, CMX-300 manufactured by Chemagnetics can be used. The measurement conditions are shown below.
• Membrane permeation flux The amount of membrane permeation of the supplied water (seawater) was expressed as the membrane permeation flux (m 3 / m 2 / day) by the amount of water permeation per day (cubic meter) per square meter of the membrane surface.
• the composite semipermeable membrane was immersed in a 25 mg / L sodium hypochlorite aqueous solution adjusted to pH 7.0 under an atmosphere of 25 ° C. for 24 hours. Then, it was immersed in a 1000 mg / L sodium bisulfite aqueous solution for 10 minutes, and subsequently washed thoroughly with water. The obtained composite semipermeable membrane was subjected to a membrane water flow test according to the above method, and the performance after chlorine deterioration was determined. (Salt permeability coefficient after the durability acceleration test) / (Salt permeability coefficient before the durability acceleration test) was obtained as the SP ratio and used as an index for deterioration of salt removal performance. It can be evaluated that the smaller the SP ratio is and the closer it is to 1, the more the decrease in the salt removal rate after the durability acceleration test is suppressed.
• Example 1 A 2.0 mass% aqueous solution of m-phenylenediamine (mPDA) was prepared.
• the support film obtained by the above operation was immersed in the above aqueous solution for 2 minutes, and the support film was slowly pulled up in the vertical direction.
• a decan solution at 45 ° C. containing 0.10% by mass of trimesic acid chloride (TMC) and 0.010% by mass of isophthalic acid chloride (IPC) is surfaced. was applied so that it was completely wet and allowed to stand for 10 seconds. Then, it was heated in an oven at 120 ° C.
• TMC trimesic acid chloride
• IPC isophthalic acid chloride
• Example 1 the composite semipermeable membrane in Example 1 was obtained.
• Example 2 The composite semipermeable membrane in Example 2 was obtained in the same manner as in Example 1 except that the concentration of IPC was 0.015% by mass.
• Example 3 The composite semipermeable membrane in Example 3 was obtained in the same manner as in Example 1 except that the concentration of IPC was 0.030% by mass.
• Example 4 A 2.0 mass% aqueous solution of mPDA was prepared.
• the support film obtained by the above operation was immersed in the above aqueous solution for 2 minutes, and the support film was slowly pulled up in the vertical direction. After removing excess aqueous solution from the surface of the support membrane by spraying nitrogen from the air nozzle, apply a decan solution at 45 ° C containing 0.10% by mass of TMC and 0.010% by mass of IPC so that the surface is completely wet, and allow it to stand for 10 seconds. Placed. Then, hot air at 120 ° C. was blown on the coated surface and hot air at 70 ° C. was blown on the back surface to heat for 1 minute. Then, it was washed with hot water of 90 degreeC for 2 minutes to obtain a composite semipermeable membrane. By the above operation, the composite semipermeable membrane in Example 4 was obtained.
• Example 5 A 2.0 mass% aqueous solution of m-phenylenediamine was prepared.
• the support film obtained by the above operation is immersed in the above aqueous solution for 2 minutes, the support film is slowly pulled up in the vertical direction, nitrogen is blown from an air nozzle to remove excess aqueous solution from the support film surface, and then TMC0.
• a decan solution at 45 ° C. containing 10% by mass is applied so that the surface is completely wet, and the mixture is allowed to stand for 3 seconds.
• a decan solution containing 45 ° C. was applied and allowed to stand for 10 seconds, and then heated in an oven at 120 ° C. for 20 seconds. Further, it was washed with hot water at 90 ° C. for 2 minutes to obtain a composite semipermeable membrane.
• the composite semipermeable membrane in Example 5 was obtained.
• Example 6 The composite semipermeable membrane in Example 6 was obtained in the same manner as in Example 1 except that terephthalic acid chloride (TPC) was used instead of IPC.
• TPC terephthalic acid chloride
• Example 7 The composite semipermeable membrane in Example 7 was obtained in the same manner as in Example 1 except that 1,3-benzenedisulfonyl chloride was used instead of the isophthalic acid chloride.
• Comparative Example 1 A 2.0 mass% aqueous solution of m-phenylenediamine was prepared.
• the support film obtained by the above operation is immersed in the above aqueous solution for 2 minutes, the support film is slowly pulled up in the vertical direction, nitrogen is blown from an air nozzle to remove excess aqueous solution from the support film surface, and then TMC0.
• a 45 ° C. decan solution containing 10% by mass is applied so that the surface is completely wet, allowed to stand for 10 seconds, heated in an oven at 120 ° C. for 20 seconds, and then washed with hot water at 90 ° C. for 2 minutes.
• the composite translucent membrane in Comparative Example 1 was obtained.
• Comparative Example 2 A composite semipermeable membrane in Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that a decan solution containing 0.10% by mass of TMC and 0.030% by mass of IPC was used.
• Comparative Example 4 The composite semipermeable membrane of Comparative Example 1 was immersed in an aqueous solution at 30 ° C. containing 50 parts by mass of sodium hypochlorite adjusted to pH 7.7 for 30 seconds, and then washed with water. Finally, the composite semipermeable membrane of Comparative Example 4 was obtained by immersing in a 1000 mass ppm sodium bisulfite aqueous solution for 13 seconds.
• Comparative Example 5 The composite semipermeable membrane of Comparative Example 1 was immersed in an aqueous solution at 35 ° C. containing 4000 mass ppm sodium nitrite adjusted to pH 3.0 for 37 seconds, and then washed with water to obtain the composite of Comparative Example 5. A semipermeable membrane was obtained.
• Table 1 shows the structure and performance of the composite semipermeable membrane obtained in each of the above examples.
• the composite semipermeable membrane of the present invention has a low SP ratio (ratio of salt permeability coefficient before and after the durability acceleration test) and high performance of maintaining a high salt removal rate even when in contact with raw water having extremely high oxidizing properties. You can see that.
• the composite semipermeable membrane of the present invention can be suitably used for desalination of brine or seawater.

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