Method for producing separation membrane for water treatment, and separation membrane for water treatment

Abstract

The present specification relates to a method for producing a water-treatment separation membrane having a high permeation flow rate, the method comprising a step for forming a polyamide active layer by coating a porous layer with an aqueous amine solution containing an imidazole-based compound and an acid halide organic solution, the acyl halide organic solution contains a phosphoric acid ester compound, the content of the phosphoric acid ester compound is 0.001-0.08 parts by weight based on 100 parts by weight of the whole acyl halide organic solution, and the weight ratio of the imidazole compound to the phosphoric acid ester compound is 1: 0.001-1: 0.4.

Description

Technical Field

[0001] This specification relates to a method for manufacturing a water treatment separation membrane and a water treatment separation membrane.

[0002] This specification claims the priority of Korean Patent Application No. 10-2023-0176707, filed with the Korean Patent Office on December 7, 2023, the entire contents of which are incorporated herein by reference. Background Art

[0003] Liquid separation is classified into microfiltration, ultrafiltration, nanofiltration, reverse osmosis, precipitation, active transport, and electrodialysis, etc., according to the pores of the membrane. Among them, the reverse osmosis method is a process of desalination using a semi-permeable membrane that allows water to pass through but is impermeable to salts. When high-pressure water containing dissolved salts is introduced into one side of the semi-permeable membrane, purified water from which salts have been removed flows to the other side at a lower pressure.

[0004] Specifically, as a representative example of such a water treatment separation membrane, a reverse osmosis membrane or a nanofiltration membrane can be cited, and research on improving the salt rejection rate or permeation flux is ongoing.

[0005] The reverse osmosis membrane / nanofiltration membrane is composed of a support layer on a non-woven fabric, an active layer of polyamide, and a protective layer on the surface of the active layer, and can separate solvents and solutes using the reverse osmosis phenomenon. The permeation flux and ion rejection rate of the reverse osmosis membrane / nanofiltration membrane are used as important indicators for showing the performance of the membrane, and such performance is greatly affected by the polyamide active layer formed by the interfacial polymerization of an aqueous solution and an organic solution containing each monomer.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] (Patent Document 1) Korean Patent Publication No. 10-2015-0016475 Summary of the Invention

[0009] Technical Problem

[0010] This specification provides a method for manufacturing a water treatment separation membrane and a water treatment separation membrane, and the method for manufacturing the water treatment separation membrane provides excellent salt rejection rate and effectively improves the permeation flux at the same time.

[0011] Solution to the Problem

[0012] One embodiment of this specification provides a method for manufacturing a water treatment separation membrane, which includes a step of forming a polyamide active layer by coating an amine aqueous solution and an acyl halide organic solution on a porous layer. The amine aqueous solution contains an imidazole-based compound, and the acyl halide organic solution contains a phosphate-based compound. Based on 100 parts by weight of the entire acyl halide organic solution, the content of the phosphate-based compound is 0.001 to 0.08 parts by weight, and the weight ratio of the imidazole-based compound to the phosphate-based compound is 1:0.001 to 1:0.4.

[0013] Another embodiment of this specification provides a water treatment separation membrane, which includes a porous layer; and a polyamide active layer provided on the porous layer, and the polyamide active layer contains an imidazole-based compound and a phosphate-based compound.

[0014] Advantages of the Invention

[0015] The method for manufacturing a water treatment separation membrane according to one embodiment of this specification can maintain the salt rejection rate of the water treatment separation membrane at a high level, and at the same time, can effectively improve the permeation flux. Specifically, when an imidazole-based compound having an imidazole structure with a resonance state is used in the aqueous solution used for forming the polyamide active layer, during interfacial polymerization, the imidazole group binds to the acyl halide group and then hydrolyzes, and at the same time, a carboxyl group is formed, which has the effect of increasing ion repulsion and free volume. In addition, when a phosphate-based compound is used in the organic solution, it promotes the diffusion of the acyl halide compound to the active layer, and has the effect of forming the active layer more smoothly. Therefore, the separation membrane manufactured using the above aqueous solution and organic solution not only provides a high salt rejection rate, but also provides a significantly increased permeation flux compared with the existing separation membrane. Generally speaking, it helps to reduce the energy required to obtain production water of the same water quality. In particular, when the above imidazole-based compound and phosphate compound are used in a weight ratio of 1:0.001 to 1:0.4, the effect is maximized. Description of the Drawings

[0016] Figure 1 The figure illustrates a water treatment separation membrane according to one embodiment of this specification.

[0017] Description of the Reference Numerals

[0018] 100: First porous support

[0019] 200: Second porous support

[0020] 300: Polyamide active layer

[0021] 400: Brine

[0022] 500: Purified water

[0023] 600: Concentrated water Detailed Embodiments

[0024] Hereinafter, the present specification will be described in more detail.

[0025] In the present specification, when it is stated that a certain member is "on" another member, it includes not only the case where a certain member is in contact with another member, but also the case where there are other members between the two members.

[0026] In the present specification, when it is stated that a certain part "contains / includes" a certain constituent element, unless there is a particularly contrary record, it means that other constituent elements can be further included, rather than excluding other constituent elements.

[0027] In the present specification, "A to B" means A or more and B or less.

[0028] According to a manufacturing method of a water treatment separation membrane according to an embodiment of the present specification, it is characterized in that it includes a step of forming a polyamide active layer by coating an amine aqueous solution and an acyl halide organic solution on a porous layer, the above amine aqueous solution contains an imidazole-based compound, the above acyl halide organic solution contains a phosphate-based compound, and the weight ratio of the above imidazole-based compound to the phosphate-based compound is 1:0.001 to 1:0.4.

[0029] Hereinafter, each component of the water treatment separation membrane and the method of forming the same will be specifically described.

[0030] <Porous Layer and Method of Forming the Same>

[0031] In an embodiment of the present specification, the above porous layer may be an ultrafiltration layer (UF).

[0032] In an embodiment of the present specification, the manufacturing method of the above water treatment separation membrane may further include a step of providing a porous layer.

[0033] In an embodiment of the present specification, the step of providing the porous layer includes a step of preparing a first porous support; and a step of forming a second porous support by coating a composition for forming the second porous support on the above first porous support.

[0034] In an embodiment of the present specification, as the above first porous support, non-woven fabric can be used. As the material of the above non-woven fabric, polyethylene terephthalate can be used, but it is not limited thereto.

[0035] The thickness of the above first porous support may be 50 μm to 150 μm, but it is not limited thereto. Preferably, the above thickness may be 80 μm to 120 μm. When the thickness of the above first porous support satisfies the above range, the durability of the water treatment separation membrane can be maintained.

[0036] In one embodiment of the present specification, the composition for forming the second porous support may contain a polymer material. As the polymer material, for example, one or more selected from polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethyl chloride, polyvinylidene fluoride, and mixtures thereof may be used, but it is not necessarily limited thereto. Specifically, polysulfone may be used as the polymer material.

[0037] In one embodiment of the present specification, based on 100 parts by weight of the whole composition for forming the second porous support, 10 to 20 parts by weight of the polysulfone may be contained. The remaining components other than polysulfone in the composition for forming the second porous support may be a solvent, and the solvent may be dimethylformamide (DMF), but it is not limited thereto, and solvents used in the technical field may be appropriately adopted.

[0038] When the polysulfone is contained in the composition for forming the second porous support within the above weight part range, when the second porous support is formed using the composition for forming the second porous support, a second porous support with a target thickness can be formed.

[0039] The thickness of the second porous support may be 30 μm to 70 μm, but it is not limited thereto. Preferably, the thickness may be 30 μm to 60 μm, or 30 μm to 50 μm. When the thickness of the coating satisfies the above range, the durability of the water treatment separation membrane including the porous layer containing the second porous support can be appropriately maintained.

[0040] The composition for forming the second porous support may be a homogeneous liquid obtained by putting polysulfone solid in the solvent dimethylformamide and dissolving it at 80°C to 85°C for 12 hours.

[0041] In one embodiment of the present specification, the overall thickness of the porous layer may be 70 μm to 250 μm.

[0042] In another embodiment of the present specification, the step of providing the porous layer includes using a commercially available porous layer.

[0043] Except for the manufacturing method, the specific description of the commercially available porous layer is the same as the above description.

[0044] <Polyamide active layer and method for forming the same>

[0045] In one embodiment of the present specification, the step of forming the above-mentioned polyamide active layer includes the step of coating an aqueous amine solution and an organic acyl halide solution on the porous layer.

[0046] In one embodiment of the present specification, the above-mentioned porous layer includes a first porous support and a second porous support, and the step of forming the above-mentioned polyamide active layer includes the step of coating the aqueous amine solution and the organic acyl halide solution on the above-mentioned second porous support.

[0047] In one embodiment of the present specification, the step of coating the aqueous amine solution and the organic acyl halide solution on the above-mentioned porous layer may be the step of coating the above-mentioned aqueous amine solution on the above-mentioned porous layer and then coating the above-mentioned organic acyl halide solution.

[0048] In one embodiment of the present specification, the step of forming the above-mentioned polyamide active layer may include the step of coating the above-mentioned aqueous amine solution on the above-mentioned porous layer to form an aqueous solution layer, and the step of coating the above-mentioned organic acyl halide solution on the above-mentioned aqueous solution layer.

[0049] In one embodiment of the present specification, the above-mentioned aqueous amine solution contains an imidazole-based compound.

[0050] When the above-mentioned aqueous amine solution contains an imidazole-based compound, the imidazole group in the resonance state binds to the acyl halide group during interfacial polymerization and then hydrolyzes, forming a carboxyl group at the same time. Due to hydrolysis, a part of the polyamide bonds are broken while the free volume increases, resulting in an increase in the permeation flux. Due to the carboxyl group formed during the hydrolysis process, the ionic repulsion increases, so that a high salt rejection rate can be maintained.

[0051] In addition, the imidazole group has the effect of protecting the acyl halide group because it binds to the acyl halide group briefly during interfacial polymerization. Therefore, more carboxyl groups are exposed on the surface, so the surface hydrophilicity is improved, which can help increase the permeation flux.

[0052] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be any one selected from imidazole and alkylimidazole or a combination thereof.

[0053] In the present specification, alkylimidazole means that one or more hydrogens of imidazole are replaced by alkyl groups, including monoalkylimidazole, dialkylimidazole, trialkylimidazole and tetraalkylimidazole.

[0054] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be imidazole or alkylimidazole.

[0055] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be imidazole or alkylimidazole having 1 to 10 carbon atoms.

[0056] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be any one or a combination thereof selected from 1-methyl imidazole, 2-methyl imidazole, 1-ethylimidazole, 2-ethyl imidazole, 1-propyl imidazole, 2-propyl imidazole, 1-butyl imidazole, 2-butylimidazole, 1,2-dimethyl imidazole, and imidazole.

[0057] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be 1-methyl imidazole, 2-methyl imidazole, 1-ethylimidazole, 2-ethyl imidazole, 1-propyl imidazole, 2-propyl imidazole, 1-butyl imidazole, 2-butylimidazole, 1,2-dimethyl imidazole, or imidazole.

[0058] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be imidazole or an alkylimidazole having 1 to 5 carbon atoms.

[0059] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be imidazole or a monoalkylimidazole.

[0060] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be imidazole or a monoalkylimidazole having 1 to 5 carbon atoms.

[0061] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be 1-methyl imidazole, 2-methyl imidazole, or imidazole.

[0062] In one embodiment of the present specification, the above-mentioned imidazole-based compound may be 1-methyl imidazole.

[0063] In one embodiment of the present specification, based on 100 parts by weight of the whole of the above-mentioned amine aqueous solution, 0.05 to 0.5 parts by weight of the above-mentioned imidazole-based compound may be included.

[0064] In one embodiment of the present specification, based on 100 parts by weight of the whole of the above-mentioned amine aqueous solution, the above-mentioned imidazole-based compound may be 0.07 to 0.5 parts by weight, 0.08 to 0.4 parts by weight, or 0.1 to 0.3 parts by weight.

[0065] When using the imidazole-based compound within the above range, a carboxyl group is appropriately formed, which helps to increase the permeation flux. More specifically, when the content of the above imidazole-based compound is less than 0.05 parts by weight, it is difficult to expect the above effects. When it is greater than 0.5 parts by weight, during interfacial polymerization, free volume is excessively formed, and the diffusion of the amine monomer to the organic solution side is overly promoted, thereby forming a thick active layer and having a problem of performance degradation.

[0066] In one embodiment of the present specification, the above amine aqueous solution may further contain an amine compound and a solvent.

[0067] In one embodiment of the present specification, the above amine aqueous solution may contain an amine compound, an imidazole-based compound, and a solvent.

[0068] In one embodiment of the present specification, the above amine compound is not particularly limited, and as long as it is a compound applicable in the technical field of the present invention, it can be appropriately adopted. For example, the above amine compound may be one or a mixture of two or more selected from m-phenylenediamine, p-phenylenediamine, 1,2,4-benzenetriamine, 1,3,6-benzenetriamine (TAB), 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 2-chloro-1,4-phenylenediamine, and 3-chloro-1,4-phenylenediamine. Specifically, m-phenylenediamine (mPD) is preferably used.

[0069] In one embodiment of the present specification, based on 100 parts by weight of the entire above amine aqueous solution, the above amine compound may be contained in an amount of 1 part by weight to 10 parts by weight, preferably, it may be contained in an amount of 1 part by weight to 7 parts by weight, and more preferably, it may be contained in an amount of 3 parts by weight to 7 parts by weight.

[0070] When the content of the above amine compound satisfies the above range, when forming the polyamide active layer contained in the water treatment separation membrane, the amine compound can be stably dissolved in the aqueous solution, and the reaction with the acyl halide organic solution can proceed smoothly.

[0071] In one embodiment of the present specification, the above amine aqueous solution may further contain a surfactant.

[0072] In one embodiment of the present specification, the above surfactant is an additive added to improve the wetting of the aqueous solution. As long as it functions as a surfactant, its type is not limited. By including a surfactant in the above amine aqueous solution, a uniform polyamide active layer can be formed.

[0073] In one embodiment of the present specification, the above surfactant may be an anionic surfactant, a cationic surfactant, a nonionic surfactant, or an amphoteric surfactant.

[0074] In one embodiment of the present specification, the surfactant may include sodium lauryl sulfate (SLS); alkyl ether sulfates; alkyl sulfates; olefin sulfonates; alkyl ether carboxylates; sulfosuccinates; aromatic sulfonates; octylphenol ethoxylates; ethoxylated nonylphenols; alkyl poly(ethylene oxide); copolymers of poly(ethylene oxide) and poly(propylene oxide); alkyl polyglycosides such as octyl glucoside and decyl maltoside; fatty alcohol such as cetyl alcohol, alkyldimethyl hydroxyethyl ammonium chloride, cetyl trimethyl ammonium bromide, cetyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride; and more than one of alkyl betaines.

[0075] In one embodiment of the present specification, the surfactant may be an anionic surfactant.

[0076] In one embodiment of the present specification, the surfactant may be sodium lauryl sulfate (SLS).

[0077] When sodium lauryl sulfate (SLS) is used as the surfactant, the degree of affinity of sodium lauryl sulfate for water and oil (Hydrophile-Lipophile Balance, HLB) is high, it dissolves well in water, and the Critical Micelle Concentration (CMC) is also high. Therefore, even if it is added in excess, it does not interfere with the formation of the polyamide active layer.

[0078] In one embodiment of the present specification, based on 100 parts by weight of the whole amine aqueous solution, the surfactant may be included in an amount of 0.001 part by weight to 2 parts by weight. Preferably, it may be included in an amount of 0.005 part by weight to 1.5 parts by weight. More preferably, it may be included in an amount of 0.01 part by weight to 1 part by weight.

[0079] When the content of the surfactant in the amine aqueous solution satisfies the above range, the effects caused by the surfactant can be appropriately exhibited.

[0080] When the content of the surfactant is less than 0.001 part by weight, since the content is too low, it cannot function as a surfactant. When it is greater than 2 parts by weight, since the amount is too large, there is a problem that the active layer cannot be formed normally.

[0081] In one embodiment of the present specification, the solvent may be water, but it is not limited thereto. As long as it is a solvent that can dissolve the amine compound and the imidazole-based compound, it can be used.

[0082] In one embodiment of the present specification, the solvent may be the remaining components in the amine aqueous solution except for the amine compound and the imidazole-based compound.

[0083] In one embodiment of the present specification, the above amine aqueous solution may further contain one or more of a wetting agent and a swelling agent. As the above wetting agent and swelling agent, there is no limitation as long as it is used in the technical field of the present invention.

[0084] In one embodiment of the present specification, the above wetting agent may be triethylamine / p-toluenesulfonic acid (TEATSA) or triethylamine / camphorsulfonic acid (TEACSA).

[0085] In one embodiment of the present specification, based on 100 parts by weight of the whole of the above amine aqueous solution, 1 to 10 parts by weight of the above wetting agent or swelling agent may be contained.

[0086] In one embodiment of the present specification, the above solvent may be the remaining components in the above amine aqueous solution except for the above amine compound, imidazole-based compound, and wetting agent.

[0087] In one embodiment of the present specification, the method applicable to the step of forming the above aqueous solution layer is not particularly limited, and any method that can form an aqueous solution layer on the above porous layer can be used without limitation. Specifically, the method of coating the above amine aqueous solution on the above porous layer is not particularly limited, and a coating method known in the technical field of the present invention can be used.

[0088] In one embodiment of the present specification, after the step of forming the above aqueous solution layer, a step of removing the excess amine aqueous solution may further be included.

[0089] The method applicable in the above step of removing the excess amine aqueous solution is not particularly limited, and a method applicable in the technical field of the present invention can be applied. The aqueous solution layer formed on the above porous layer may be unevenly distributed when there is too much aqueous solution present on the porous layer, but in the case of uneven distribution of the aqueous solution, an uneven active layer may be formed by subsequent interfacial polymerization. Therefore, it is preferable to remove the excess aqueous solution after forming the aqueous solution layer on the above porous layer. The removal of the excess aqueous solution is not particularly limited. For example, it can be carried out using a sponge, an air knife, blowing nitrogen, natural drying, a pressure roller, etc.

[0090] In one embodiment of the present specification, the above acyl halide organic solution contains a phosphate ester-based compound.

[0091] When forming a polyamide active layer using a phosphate compound in an organic solution together with the above aqueous solution, the diffusion of the acyl halide compound into the polyamide active layer is promoted, thereby smoothly forming the polyamide active layer. Therefore, a separation membrane can be manufactured more effectively.

[0092] In one embodiment of the present specification, the above phosphate compound may be any one selected from alkyl phosphates and alkyl phosphonoacetates, or a combination thereof.

[0093] In the present specification, an alkyl phosphate refers to a compound in which one or more oxygen atoms of a phosphate ester are bonded to an alkyl group, including monoalkyl phosphates, dialkyl phosphates, and trialkyl phosphates.

[0094] In the present specification, an alkyl phosphonoacetate refers to a compound in which one or more oxygen atoms of a phosphonoacetate are bonded to an alkyl group, including monoalkyl phosphonoacetates, dialkyl phosphonoacetates, and trialkyl phosphonoacetates.

[0095] In one embodiment of the present specification, the above phosphate compound may be an alkyl phosphate or an alkyl phosphonoacetate.

[0096] In one embodiment of the present specification, the above phosphate compound may be an alkyl phosphate having 1 to 30 carbon atoms, or an alkyl phosphonoacetate having 1 to 30 carbon atoms.

[0097] In one embodiment of the present specification, the above phosphate compound may be an alkyl phosphate.

[0098] In one embodiment of the present specification, the above phosphate compound may be an alkyl phosphate having 1 to 30 carbon atoms.

[0099] In one embodiment of the present specification, the above phosphate compound may be an alkyl phosphate having 1 to 20 carbon atoms.

[0100] In one embodiment of the present specification, the above-mentioned phosphate ester compound may be any one selected from methylphosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, trimethyl phosphate, triethylphosphate, tripropyl phosphate, tributyl phosphate, triphenyl phosphate, trimethyl phosphonoacetate, and triethyl phosphonoacetate, or a combination thereof.

[0101] In one embodiment of the present specification, the above-mentioned phosphate ester compound may be methylphosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, trimethyl phosphate, triethylphosphate, tripropyl phosphate, tributyl phosphate, triphenyl phosphate, trimethyl phosphonoacetate, or triethyl phosphonoacetate.

[0102] In one embodiment of the present specification, the above-mentioned phosphate ester compound may be triethylphosphate, tributyl phosphate, or triethyl phosphonoacetate.

[0103] In one embodiment of the present specification, the above-mentioned phosphate ester compound may be triethylphosphate or tributyl phosphate.

[0104] In one embodiment of the present specification, the above-mentioned phosphate ester compound may be tributyl phosphate.

[0105] In one embodiment of the present specification, based on 100 parts by weight of the whole of the above-mentioned acyl halide organic solution, 0.001 part by weight to 0.08 part by weight of the above-mentioned phosphate ester compound may be included.

[0106] In one embodiment of the present specification, based on 100 parts by weight of the whole of the above-mentioned acyl halide organic solution, the above-mentioned phosphate ester compound may be 0.001 part by weight to 0.08 part by weight, 0.001 part by weight to 0.05 part by weight, or 0.001 part by weight to 0.03 part by weight.

[0107] When the phosphate ester compound is used within the above content range, the above-mentioned effects can be expected. When the content is less than or more than the above range, it cannot help in the formation of the polyamide active layer.

[0108] In one embodiment of the present specification, the weight ratio of the above-mentioned imidazole-based compound to the phosphate-based compound is from 1:0.001 to 1:0.4.

[0109] When more than 40 parts by weight of the above-mentioned phosphate-based compound is used relative to 100 parts by weight of the imidazole-based compound, the permeation flux can be increased, but there is a problem that the salt rejection rate decreases sharply. Specifically, when the above-mentioned phosphate-based compound is used in an amount greater than the scope of the present invention relative to the imidazole-based compound, a larger amount of acyl halide than in the prior art is promoted to the interface by the phosphate ester, and more of the imidazoles present in the aqueous solution react, resulting in excessive hydrolysis, and thus the salt rejection rate decreases sharply.

[0110] In one embodiment of the present specification, the weight ratio of the above-mentioned imidazole-based compound to the phosphate-based compound may be from 1:0.001 to 1:0.3.

[0111] In one embodiment of the present specification, the weight ratio of the above-mentioned imidazole-based compound to the phosphate-based compound may be from 1:0.1 to 1:0.3.

[0112] In one embodiment of the present specification, the above-mentioned imidazole-based compound is an alkylimidazole, and the above-mentioned phosphate-based compound may be an alkyl phosphate.

[0113] In one embodiment of the present specification, the above-mentioned imidazole-based compound is a monoalkylimidazole, and the above-mentioned phosphate-based compound may be a trialkyl phosphate.

[0114] In one embodiment of the present specification, the above-mentioned imidazole-based compound is a monoalkylimidazole having 1 to 5 carbon atoms, and the above-mentioned phosphate-based compound may be a trialkyl phosphate having 1 to 20 carbon atoms.

[0115] In one embodiment of the present specification, the above-mentioned imidazole-based compound is 1-methylimidazole, and the above-mentioned phosphate-based compound may be 2-tributyl phosphate.

[0116] In one embodiment of the present specification, the above-mentioned acyl halide organic solution may further contain an acyl halide compound and an organic solvent.

[0117] In one embodiment of the present specification, the above-mentioned acyl halide organic solution may contain an acyl halide compound, a phosphate-based compound, and an organic solvent.

[0118] In one embodiment of the present specification, the above-mentioned acyl halide compound is not particularly limited, but for example, it may be an aliphatic compound having 2 to 3 carboxylic acid halides.

[0119] In one embodiment of the present specification, the above acyl halide compound may be one or a mixture of two or more selected from trimesoyl chloride (TMC), isophthaloyl chloride, and terephthaloyl chloride.

[0120] In one embodiment of the present specification, the above acyl halide compound may be trimesoyl chloride (TMC).

[0121] In one embodiment of the present specification, based on 100 parts by weight of the whole acyl halide organic solution, 0.1 to 0.5 parts by weight of the above acyl halide compound may be included. When the content of the above acyl halide compound satisfies the above range, it has the effect of preventing the reduction of the salt rejection rate and permeation flux of the finally manufactured water treatment separation membrane.

[0122] In one embodiment of the present specification, as the above organic solvent, aliphatic hydrocarbon solvents can be used, for example, Freons and hydrophobic liquids that do not mix with water such as hexane, cyclohexane, heptane, and alkanes. For example, IsoPar (Exxon), ISOL-C (SK Chem), ISOL-G (Exxon), etc., which are alkanes having 5 to 12 carbon atoms and their mixtures, are not limited thereto.

[0123] In one embodiment of the present specification, the above organic solvent may be IsoPar G, which is a paraffin-based solvent.

[0124] In one embodiment of the present specification, based on 100 parts by weight of the whole acyl halide organic solution, 99.5 to 99.9 parts by weight of the above organic solvent may be included. When the content of the above organic solvent satisfies the above range, it has the effect of preventing the reduction of the salt rejection rate and permeation flux of the finally manufactured water treatment separation membrane.

[0125] In one embodiment of the present specification, the above organic solvent may be the remaining components in the above acyl halide organic solution except for the above acyl halide compound and phosphate ester compounds.

[0126] In one embodiment of the present specification, the method applicable in the step of coating the above acyl halide organic solution is not particularly limited, and coating methods well-known in the art can be used.

[0127] In one embodiment of the present specification, in the step of coating the above acyl halide organic solution, interfacial polymerization of the above amine aqueous solution and the above acyl halide organic solution may occur. Specifically, when the above acyl halide organic solution is coated on the above aqueous solution layer, the amine aqueous solution in the above aqueous solution layer contacts the above acyl halide organic solution, and interfacial polymerization occurs during the contact (simultaneously with the contact).

[0128] In one embodiment of the present specification, the step of coating the organic solution of acyl halide on the above aqueous solution layer may be a step of interfacial polymerization of the aqueous amine solution in the above aqueous solution layer and the organic solution of acyl halide.

[0129] Specifically, when the organic solution of acyl halide is coated on the above aqueous solution layer, the amine compound in the above aqueous solution layer reacts with the acyl halide compound in the above organic solution, and at the same time, polyamide is formed by interfacial polymerization, adsorbed on the porous layer to form a film, thereby forming a polyamide active layer.

[0130] In one embodiment of the present specification, the step of forming the above polyamide active layer may further include a step of drying the polyamide active layer formed on the above porous layer after coating the above organic solution on the above aqueous solution layer.

[0131] In one embodiment of the present specification, the drying method in the step of drying the above polyamide active layer is not particularly limited, and a method applicable in the technical field of the present invention can be appropriately adopted. For example, the above polyamide active layer can be dried in an oven at 90 °C for 3 minutes.

[0132] In one embodiment of the present specification, the thickness of the above polyamide active layer can be 100 nm to 500 nm. Preferably, the thickness of the above polyamide active layer can be 150 nm to 450 nm, or 200 nm to 400 nm. When the thickness of the above polyamide active layer meets the above range, the salt rejection rate and permeation flux of the water treatment separation membrane to be achieved in the present specification can be satisfied.

[0133] In one embodiment of the present specification, the step of forming the above polyamide active layer may further include a step of washing the above polyamide active layer in water after the step of drying the above polyamide active layer. By washing the above polyamide active layer in water, unreacted substances that did not participate in the interfacial polymerization can be removed.

[0134] In one embodiment of the present specification, in the step of washing the above polyamide active layer in water, the washing method is not particularly limited, and a method applicable in the technical field of the present invention can be appropriately adopted. For example, the above polyamide active layer can be immersed in water at 80 °C for 5 minutes.

[0135] <Protective layer and method for forming the same>

[0136] The method for manufacturing a water treatment separation membrane according to one embodiment of the present specification may further include a step of forming a protective layer on the above polyamide active layer.

[0137] In one embodiment of the present specification, the step of forming the above protective layer may include a step of bringing the above polyamide active layer into contact with an aqueous solution for forming the protective layer.

[0138] In one embodiment of the present specification, the step of bringing the above-mentioned polyamide active layer into contact with the aqueous solution for forming the above-mentioned protective layer can be carried out by methods such as dipping, slot-die coating, bank coating, gravure coating, etc., but is not limited thereto.

[0139] In one embodiment of the present specification, the step of bringing the above-mentioned polyamide active layer into contact with the aqueous solution for forming the above-mentioned protective layer may be the step of dipping the above-mentioned polyamide active layer in the aqueous solution for forming the above-mentioned protective layer.

[0140] In one embodiment of the present specification, the step of dipping the above-mentioned polyamide active layer in the aqueous solution for forming the above-mentioned protective layer can be carried out for 30 seconds to 10 minutes, 1 minute to 8 minutes, or 3 minutes to 7 minutes.

[0141] In addition, if necessary, after dipping in the aqueous solution for forming the above-mentioned protective layer, a step of drying in an oven at 90 °C for 3 minutes can also be carried out.

[0142] In one embodiment of the present specification, the aqueous solution for forming the above-mentioned protective layer may contain one or more of glycerol, polyvinyl alcohol (PVA), and polyvinylpyrrolidone (PVP).

[0143] In one embodiment of the present specification, the aqueous solution for forming the above-mentioned protective layer may contain glycerol.

[0144] In one embodiment of the present specification, the aqueous solution for forming the above-mentioned protective layer may contain glycerol at a concentration of 1% to 20%.

[0145] In one embodiment of the present specification, the aqueous solution for forming the above-mentioned protective layer may contain the above-mentioned glycerol at a concentration of 5% to 15%.

[0146] In one embodiment of the present specification, the aqueous solution for forming the above-mentioned protective layer may further contain a solvent, and the solvent may be water, but is not limited thereto.

[0147] In one embodiment of the present specification, the thickness of the above-mentioned protective layer is not particularly limited, and the overall thickness of the water treatment separation membrane can be appropriately formed within a range satisfying 100 μm or more and 250 μm or less.

[0148] Next, the water treatment separation membrane will be described.

[0149] <Performance of the water treatment separation membrane>

[0150] In one embodiment of the present specification, the desalination rate of the above-mentioned water treatment separation membrane measured under the conditions of 2000 ppm NaCl aqueous solution, a pressure of 150 psi, a temperature of 25 °C, and a flow rate of 4 L / minute can be 99.20% or more, and the permeate flux can be 28.00 GFD or more.

[0151] In one embodiment of the present specification, the permeate flux of the above-mentioned water treatment separation membrane measured under the conditions of 2000 ppm NaCl aqueous solution, a pressure of 150 psi, a temperature of 25 °C, and a flow rate of 4 L / minute can be 28.00 GFD or more, 28.10 GFD or more, or 28.30 GFD or more. There is no upper limit, but it can be 40.0 GFD or less, 39.0 GFD or less, or 38 GFD or less.

[0152] In one embodiment of the present specification, the permeate flux of the above-mentioned water treatment separation membrane measured under the conditions of 2000 ppm NaCl aqueous solution, a pressure of 150 psi, a temperature of 25 °C, and a flow rate of 4 L / minute can be 28.00 GFD or more and 40.0 GFD or less. Preferably, it can be 28.10 GFD or more and 39 GFD or less. More preferably, it can be 28.30 GFD or more and 38 GFD or less.

[0153] In one embodiment of the present specification, the desalination rate of the above-mentioned water treatment separation membrane measured under the conditions of 2000 ppm NaCl aqueous solution, a pressure of 150 psi, a temperature of 25 °C, and a flow rate of 4 L / minute can be 99.20% or more, 99.23% or more, or 99.25% or more. There is no upper limit, but it can be 100% or less, or 99.90% or less.

[0154] In one embodiment of the present specification, the desalination rate of the above-mentioned water treatment separation membrane measured under the conditions of 2000 ppm NaCl aqueous solution, a pressure of 150 psi, a temperature of 25 °C, and a flow rate of 4 L / minute can be 99.20% or more, and the permeate flux can be 28.10 GFD or more.

[0155] In one embodiment of the present specification, the above-mentioned water treatment separation membrane in 2000 ppm MgSO 4 aqueous solution, a pressure of 70 psi, a temperature of 25 °C, and a flow rate of 4 L / minute, the desalination rate can be 99.30% or more, and the permeate flux can be 16.00 GFD or more.

[0156] In one embodiment of the present specification, the above-mentioned water treatment separation membrane in 2000 ppm MgSO 4The permeation flux measured under the conditions of an aqueous solution, a pressure of 70 psi, a temperature of 25 °C, and a flow rate of 4 L / min can be 16.00 GFD or more, 16.10 GFD or more, or 16.20 GFD or more. There is no upper limit, but it can be 40.0 GFD or less, 39.0 GFD or less, or 38 GFD or less.

[0157] In one embodiment of the present specification, the above-mentioned water treatment separation membrane is in an aqueous solution of 2000 ppm MgSO 4 The permeation flux measured under the conditions of an aqueous solution, a pressure of 70 psi, a temperature of 25 °C, and a flow rate of 4 L / min can be 16.00 GFD or more and 40.0 GFD or less. Preferably, it can be 16.10 GFD or more and 39 GFD or less. More preferably, it can be 16.20 GFD or more and 38 GFD or less.

[0158] In one embodiment of the present specification, the above-mentioned water treatment separation membrane is in an aqueous solution of 2000 ppm MgSO 4 The salt rejection rate measured under the conditions of an aqueous solution, a pressure of 70 psi, a temperature of 25 °C, and a flow rate of 4 L / min can be 99.30% or more, 99.33% or more, or 99.34% or more. There is no upper limit, but it can be 100% or less, or 99.90% or less.

[0159] In one embodiment of the present specification, the above-mentioned water treatment separation membrane is in an aqueous solution of 2000 ppm MgSO 4 The salt rejection rate measured under the conditions of an aqueous solution, a pressure of 70 psi, a temperature of 25 °C, and a flow rate of 4 L / min can be 99.30% or more, and the permeation flux can be 16.10 GFD or more.

[0160] That is, the water treatment separation membrane manufactured according to one embodiment of the present specification ensures a minimum salt rejection rate of 99% under various brine conditions and pressure conditions, and also provides significantly improved performance in terms of permeation flux.

[0161] In the present specification, for the measurement of the above-mentioned permeation flux and salt rejection rate, after the equipment was operated for about 1 hour under specific pressure conditions and flow rate conditions for the brine to be evaluated to confirm stabilization, the amount of water permeated in 15 minutes at 25 °C was measured, and the permeation flux (Flux, GFD) was calculated. The conductivity meter was used to analyze the conductivity of the raw water and the salt concentration of the treated water after permeation, and thus the salt rejection rate (Rejection, %) was calculated.

[0162] In the present specification, the unit of the permeation flux is GFD (gallons / ft 2 / day (gallons / ft 2 / day)).

[0163] <Water treatment separation membrane>

[0164] Another embodiment of the present specification provides a water treatment separation membrane, which includes a porous layer and a polyamide active layer provided on the porous layer, and the polyamide active layer contains an imidazole-based compound and a phosphate-based compound.

[0165] In one embodiment of the present specification, whether the polyamide active layer contains an imidazole-based compound and a phosphate-based compound can be confirmed by using GC / MS or GC / FID analysis methods.

[0166] Specifically, the manufactured polyamide active layer is analyzed by GC / MS or GC / FID, and the imidazole-based compound and the phosphate-based compound used when manufacturing the polyamide active layer are respectively analyzed by GC / MS or GC / FID, and the same peaks are confirmed in the GC / MS or GC / FID of the polyamide active layer, so as to confirm whether it is contained.

[0167] The performance of the water treatment separation membrane according to one embodiment of the present specification is the same as that described above.

[0168] Another embodiment of the present specification provides a water treatment separation membrane manufactured by the above-mentioned manufacturing method of the water treatment separation membrane.

[0169] The water treatment separation membrane manufactured by the manufacturing method according to one embodiment of the present specification includes a porous layer and a polyamide active layer provided on the porous layer.

[0170] The water treatment separation membrane manufactured by the manufacturing method according to another embodiment of the present specification includes a porous layer; a polyamide active layer provided on the porous layer; and a protective layer provided on the polyamide active layer.

[0171] The water treatment separation membrane manufactured by the manufacturing method according to another embodiment of the present specification includes a first porous support; a second porous support provided on the first porous support; a polyamide active layer provided on the second porous support; and a protective layer provided on the polyamide active layer.

[0172] The specific descriptions of the porous layer, the polyamide active layer and the protective layer are the same as the above descriptions.

[0173] Figure 1 The water treatment separation membrane according to one embodiment of the present specification is illustrated. Specifically, Figure 1The figure illustrates a water treatment separation membrane in which a porous layer including a first porous support 100 and a second porous support 200 and a polyamide active layer 300 are sequentially provided. Brine 400 flows into the polyamide active layer 300, purified water 500 is discharged through the first porous support 100, and concentrated water 600 cannot pass through the polyamide active layer 300 and is discharged to the outside. The water treatment separation membrane according to an embodiment of the present specification is not limited to Figure 1 the structure, and may further include other components.

[0174] In an embodiment of the present specification, the thickness of the water treatment separation membrane may be 100 μm or more and 250 μm or less. When the thickness of the water treatment separation membrane is within the above range, the salt rejection rate and permeation flux of the water treatment separation membrane to be achieved in the present specification can be appropriately maintained. When the thickness of the water treatment separation membrane is less than 100 μm, the permeation flux of the water treatment separation membrane increases but the salt rejection rate may decrease. When the thickness of the water treatment separation membrane is greater than 250 μm, the salt rejection rate of the water treatment separation membrane increases but the permeation flux may decrease.

[0175] The thickness of the water treatment separation membrane refers to the thickness of the water treatment separation membrane including the porous layer, the polyamide active layer, and the protective layer.

[0176] <Water treatment module>

[0177] Another embodiment of the present specification provides a water treatment module including one or more of the above-described water treatment separation membranes.

[0178] The number of water treatment separation membranes included in the water treatment module may be 1 to 50, may be 1 to 30, and preferably may be 24 to 28, but is not limited thereto.

[0179] The specific type of the water treatment module is not particularly limited. In an example thereof, it includes a plate & frame module, a tubular module, a hollow & fiber module, or a spiral wound module, etc. In addition, as long as the water treatment module includes the water treatment separation membrane manufactured according to an embodiment of the present specification, there are no particular restrictions on other components and manufacturing methods, etc., and conventional methods well-known in the art can be adopted without limitation.

[0180] On the other hand, the water treatment module according to an embodiment of the present specification has excellent salt rejection rate and permeation flux, and excellent chemical stability, and thus can be usefully used in water treatment devices such as household / industrial water purification devices, sewage treatment devices, seawater desalination treatment devices, etc.

[0181] Next, in order to specifically describe this specification, examples will be given and described in detail. However, the examples of this specification can be deformed into various different forms, and the scope of this specification is not construed as being limited to the examples detailed below. The examples of this specification are provided to more comprehensively explain this specification to those skilled in the art.

[0182] [Manufacturing Example] Manufacture of Water Treatment Separation Membrane

[0183] An amine aqueous solution (remaining component: water) containing the following content in Table 1 was prepared using 5% by weight of m-phenylenediamine, 0.05% by weight of SLS, 3% by weight of TEACSA, and the imidazole-based compound described in Table 1 below. An acyl halide organic solution (remaining component: Isopar G) containing the following content in Table 1 was prepared using 0.2% by weight of TMC and the phosphate ester compound described in Table 1 below. The above amine aqueous solution was coated on a UF support (100 μm) to form an aqueous solution layer. After 10 seconds, the remaining aqueous solution was removed by an air knife. Then, after coating the above acyl halide organic solution on the above aqueous solution layer, after 10 seconds, it was dried in an oven at 90 °C for 3 minutes to form a polyamide active layer (0.2 - 0.4 μm). Then, the above active layer was immersed in water at 80 °C for 5 minutes to remove residues, immersed in a 10% glycerol solution for 5 minutes, and then dried in an oven at 90 °C for 3 minutes to manufacture a water treatment separation membrane.

[0184] The parts by weight described in Table 1 below are based on 100 parts by weight of the entire above aqueous solution or organic solution.

[0185]

Table 1

[0186]

[0187] *A-1: 1-Methylimidazole

[0188] *A-2: Imidazole

[0189] *A-3: 2-Methylimidazole

[0190] *B-1: Triethyl Phosphate

[0191] *B-2: Tributyl Phosphate

[0192] *B-3: Triethyl Phosphonoacetate

[0193] [Experimental Example] Evaluation of Water Treatment Separation Membrane

[0194] 1) Measurement of permeation flux and salt rejection: Condition 1

[0195] For the water treatment separation membrane produced in the above production example, after operating the equipment for about 1 hour at a flow rate of 4 L / minute and a pressure of 150 psi with a 2000 ppm NaCl aqueous solution to confirm stabilization, the amount of water permeated in 15 minutes at 25 °C was measured, and the permeation flux (GFD) was calculated. The conductivity meter was used to analyze the conductivity of the raw water and the salt concentration of the treated water after permeation, and the results of calculating the salt rejection rate (%) are shown in Table 2 below.

[0196]

Table 2

[0197]

[0198] 2) Measurement of permeation flux and salt rejection: Condition 2

[0199] For the water treatment separation membrane produced in the above production example, a MgSO 4 aqueous solution at a flow rate of 4 L / minute and a pressure of 70 psi was used to operate the equipment for about 1 hour to confirm stabilization. Then, the amount of water permeated in 15 minutes at 25 °C was measured, and the permeation flux (GFD) was calculated. The conductivity meter was used to analyze the conductivity of the raw water and the salt concentration of the treated water after permeation, and the results of calculating the salt rejection rate (%) are shown in Table 3 below.

[0200]

Table 3

[0201]

[0202] From the results in Tables 2 and 3 above, it can be confirmed that for the water treatment separation membrane produced according to the present invention, compared with the water treatment separation membranes different from the present invention, it provides the same or a higher level of salt rejection rate under various brine and pressure conditions, and at the same time, the permeation flux is also significantly improved. Specifically, for Conditions 1 and 2, the permeation fluxes and salt rejection rates of the example group and the comparative example group were compared, and it was confirmed that there were comparative examples that met either the permeation flux or the salt rejection rate to be achieved in the present invention, but there were no comparative examples that met both. There is a relationship where when either the permeation flux or the salt rejection rate is improved, the other decreases. However, when using the water treatment separation membrane of the present invention, it was found that both performances showed a high level.

[0203] In Comparative Example 1, no imidazole-based compound and phosphate-based compound were used. It can be seen that the salt rejection rate was relatively high, but the permeation flux was only about 50% of that of the example. In addition, the permeation flux of Comparative Example 2 without an imidazole-based compound did not reach the level of the example. Although the contents of Comparative Examples 3 to 9 without a phosphate-based compound were adjusted diversely, compared with the permeation flux and salt rejection rate provided by the water treatment separation membrane of the present invention, it was also confirmed that they had lower performances.

[0204] Comparative Examples 10 and 11 are the results of using both an imidazole-based compound and a phosphate-based compound, but in amounts that do not satisfy the weight ratio range of the present invention. It can be seen that the performance of either the permeation flux or the salt rejection rate is significantly reduced.

[0205] In summary, as shown in the present invention, a water treatment separation membrane produced by including an imidazole-based compound in an amine aqueous solution, including a phosphate-based compound in an acyl halide organic solution, and using the imidazole-based compound and the phosphate-based compound in a weight ratio of 1:0.001 to 1:0.4 can provide the effect of effectively improving the permeation flux without reducing the salt rejection rate.

Claims

1. A method for producing a water treatment separation membrane, comprising the step of coating an amine aqueous solution and an acyl halide organic solution on a porous layer to form a polyamide active layer, The aqueous amine solution contains an imidazole compound, The acyl halide organic solution comprises a phosphate ester compound, Based on 100 parts by weight of the acyl halide organic solution as a whole, the content of the phosphate ester compound is 0.001 parts by weight to 0.08 parts by weight. The weight ratio of the imidazole compound to the phosphate compound is 1:0.001 to 1:0.

4.

2. The method for producing a water treatment separation membrane according to claim 1, wherein: The imidazole compound is any one selected from imidazole and alkyl imidazole or a combination thereof.

3. The method for producing a water treatment separation membrane according to claim 1, wherein: The aqueous amine solution contains 0.05 to 0.5 parts by weight of the imidazole compound based on 100 parts by weight of the entire aqueous amine solution.

4. The method for producing a water treatment separation membrane according to claim 1, wherein: The phosphate ester compound is any one selected from alkyl phosphates and alkyl phosphonoacetates, or a combination thereof.

5. The method for producing a water treatment separation membrane according to claim 1, wherein: The acyl halide organic solution contains 0.001 to 0.05 parts by weight of the phosphate compound based on 100 parts by weight of the entire acyl halide organic solution.

6. The method for producing a water treatment separation membrane according to claim 1, wherein: The method also includes the step of forming a protective layer on the polyamide active layer.

7. The method for producing a water treatment separation membrane according to claim 6, wherein: The step of forming the protective layer includes the step of coating an aqueous solution for forming a protective layer on the polyamide active layer.

8. The method for producing a water treatment separation membrane according to claim 7, wherein: The protective layer-forming aqueous solution includes glycerin at a concentration of 1% to 20%.

9. The method for producing a water treatment separation membrane according to claim 1, wherein: The water treatment separation membrane has a salt removal rate of 99.20% or more and a permeation flow rate of 28.00 GFD or more measured under the conditions of 2000 ppm NaCl aqueous solution, 150 psi pressure, 25° C., and 4 L / min.

10. The method for producing a water treatment separation membrane according to claim 1, wherein: The water treatment separation membrane has a desalination rate of 99.30% or more and a permeation flow rate of 16.00 GFD or more measured under the conditions of 2000 ppm MgSO4 aqueous solution, 70 psi pressure, 25°C temperature, and 4 L / min.

11. A water treatment separation membrane, comprising: Porous layer; and a polyamide active layer disposed on the porous layer, The polyamide active layer comprises an imidazole compound and a phosphate compound.

12. The water treatment separation membrane according to claim 11, wherein The water treatment separation membrane has a salt removal rate of 99.20% or more and a permeation flow rate of 28.00 GFD or more measured under the conditions of 2000 ppm NaCl aqueous solution, 150 psi pressure, 25° C., and 4 L / min.

13. The water treatment separation membrane according to claim 11, wherein The water treatment separation membrane has a desalination rate of 99.30% or more and a permeation flow rate of 16.00 GFD or more measured under the conditions of 2000 ppm MgSO4 aqueous solution, 70 psi pressure, 25°C temperature, and 4 L / min.

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