JP2012055858A - Method for production of semipermeable composite membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for production of a semipermeable composite membrane having a uniform defect-free skin layer on a porous support, and to provide the semipermeable composite membrane obtained by the method.SOLUTION: The method for production of a semipermeable composite membrane includes the steps of: hydrophilizing a porous support; bringing an aqueous solution containing a polyfunctional amine component into contact with the surface of the hydrophilized porous support; and bringing an organic solution including a polyfunctional acid halide component into contact with the surface of the porous support contacting with the above aqueous solution and performing the interfacial polymerization of both polyfunctional amine and acid halide components to form the skin layer including a polyamide-based resin on the surface of the porous support. The method is characterized by directly or indirectly applying vibration to the aqueous solution used for hydrophilization, that including the polyfunctional amine component or porous support for 20 sec or more in the hydrophilization process and/or solution contact process.

Description

  The present invention relates to a method for producing a composite semipermeable membrane comprising a skin layer containing a polyamide-based resin and a porous support for supporting the skin layer. Such a composite semipermeable membrane is suitable for production of ultrapure water, desalination of brine or seawater, etc., and it is also a source of contamination contained in it due to contamination that causes pollution such as dye wastewater and electrodeposition paint wastewater. Alternatively, effective substances can be removed and recovered, contributing to the closure of wastewater. Moreover, it can be used for advanced treatments such as concentration of active ingredients in food applications and removal of harmful components in water purification and sewage applications.

  Currently, a composite semipermeable membrane has been proposed in which a skin layer made of polyamide obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide is formed on a porous support. (Patent Document 1).

  Patent Document 2 describes that a porous porous membrane is immersed in degassed water in order to easily hydrophilize the membrane without causing contamination by foreign substances. Yes.

  Patent Document 3 describes that the separation membrane immersed in the liquid is washed with ultrasonic waves in order to remove unreacted residues in the liquid separation membrane.

  Patent Document 4 describes that the aromatic polysulfone porous membrane is irradiated with ultrasonic waves in an organic solvent in order to improve the water transmission rate of the aromatic polysulfone porous membrane.

  However, in the conventional method for producing a composite semipermeable membrane, there may be a problem that a defect occurs in the skin layer formed on the porous support and the salt blocking property is lowered.

JP 2001-79372 A JP-A-5-208121 JP 2005-66464 A Japanese Patent Laid-Open No. 2-139021

  An object of this invention is to provide the manufacturing method of the composite semipermeable membrane which has a uniform and defect-free skin layer on a porous support body, and the composite semipermeable membrane obtained by this method.

  As a result of intensive studies to achieve the above object, the present inventors have found that a uniform and defect-free skin layer can be formed on a porous support by the following production method, and the present invention has been completed. It came to do.

That is, the present invention includes a hydrophilic treatment step for hydrophilizing a porous support, an aqueous solution contact step for bringing an aqueous solution containing a polyfunctional amine component into contact with the surface of the porous support subjected to a hydrophilic treatment, and contacting the aqueous solution. The skin layer containing a polyamide resin is made porous by interfacial polymerization of a polyfunctional amine component and a polyfunctional acid halide component by bringing an organic solution containing the polyfunctional acid halide component into contact with the surface of the porous support. In the method for producing a composite semipermeable membrane including a step of forming on the surface of the support,
Applying vibration for 20 seconds or more directly or indirectly to the aqueous solution used for the hydrophilic treatment, the aqueous solution containing the polyfunctional amine component, or the porous support during the hydrophilic treatment step and / or the aqueous solution contact step. The manufacturing method of the composite semipermeable membrane characterized by these.

  The inventors of the present invention have the reason that a defect occurs in the skin layer when the skin layer is formed on the porous support by the conventional production method, in the aqueous solution used for the hydrophilization treatment and the aqueous solution containing the polyfunctional amine component. It has been found that there are bubbles that are generated and bubbles that are generated on the surface of the porous support when the aqueous solution is brought into contact with the surface of the porous support. Specifically, when the skin layer is formed on the porous support with the bubbles remaining, the skin layer is formed in a state where the bubbles are floated, and the skin layer is torn at such a floating portion. It is thought that defects are likely to occur.

  As in the present invention, during the hydrophilization treatment step and / or the aqueous solution contact step, the aqueous solution used for the hydrophilization treatment, the aqueous solution containing a polyfunctional amine component, or the porous support directly or indirectly for 20 seconds or more. By applying vibration, the bubbles can be effectively removed. As a result, a floating portion is hardly generated in the skin layer, and a uniform and defect-free skin layer can be formed on the porous support. If the vibration is applied for less than 20 seconds, the bubbles cannot be removed sufficiently, and defects are likely to occur in the skin layer.

  The applied vibration is preferably ultrasonic vibration. Ultrasonic vibration can effectively remove the bubbles in a shorter time than physical vibration.

  The hydrophilization treatment step is preferably a step of immersing the porous support in an alcohol-containing aqueous solution. It is easy to form a uniform skin layer by previously immersing the porous support in an alcohol-containing aqueous solution to make it hydrophilic. In addition, the porous support is hydrophilized and the alcohol-containing aqueous solution is subjected to vibration for 20 seconds or longer (vibration is also transmitted to the porous support) to bring the alcohol-containing aqueous solution into contact with the surface of the porous support. In this case, bubbles generated on the surface of the porous support can be effectively removed. As a result, when an aqueous solution containing a polyfunctional amine component is brought into contact with the surface of the porous support, bubbles are less likely to be generated on the surface irregularities of the porous support.

  The average pore size of the porous support is preferably 0.01 to 0.4 μm. The arithmetic average roughness (Ra) of the surface of the porous support is preferably 0.6 μm or more. When the production method of the present invention is employed, a uniform and defect-free skin layer is formed on the porous support even when the surface pore size of the porous support is large or the surface unevenness of the porous support is large. Can be formed.

  The material for forming the porous support is preferably an epoxy resin. Epoxy resins are suitable as a material for forming a porous support because they are chemically, mechanically and thermally stable.

  Moreover, this invention relates to the composite semipermeable membrane obtained by the said manufacturing method.

  Since the composite semipermeable membrane obtained by the production method of the present invention has a uniform and defect-free skin layer on the porous support, it has superior salt-blocking properties compared to conventional composite semipermeable membranes. .

2 is a photograph showing a dyed state of a defective portion of the composite semipermeable membrane obtained in Example 1. FIG. 4 is a photograph showing a dyed state of a defective portion of the composite semipermeable membrane obtained in Example 2. FIG. 4 is a photograph showing a dyed state of a defective portion of a composite semipermeable membrane obtained in Comparative Example 1. 6 is a photograph showing a dyed state of a defective portion of a composite semipermeable membrane obtained in Comparative Example 2.

  Embodiments of the present invention will be described below. The method for producing a composite semipermeable membrane according to the present invention includes a hydrophilic treatment step for hydrophilizing a porous support, and an aqueous solution contact step for bringing an aqueous solution containing a polyfunctional amine component into contact with the surface of the porous support subjected to a hydrophilic treatment. And an organic solution containing a polyfunctional acid halide component is brought into contact with the surface of the porous support in contact with the aqueous solution to cause interfacial polymerization of the polyfunctional amine component and the polyfunctional acid halide component. Forming a skin layer on the surface of the porous support.

  The polyfunctional amine component is a polyfunctional amine having two or more reactive amino groups, and examples thereof include aromatic, aliphatic, and alicyclic polyfunctional amines.

  Examples of the aromatic polyfunctional amine include m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, 1,3,5-triaminobenzene, 1,2,4-triaminobenzene, and 3,5-diamino. Examples include benzoic acid, 2,4-diaminotoluene, 2,6-diaminotoluene, N, N′-dimethyl-m-phenylenediamine, 2,4-diaminoanisole, amidole, xylylenediamine and the like.

  Examples of the aliphatic polyfunctional amine include ethylenediamine, propylenediamine, tris (2-aminoethyl) amine, and n-phenyl-ethylenediamine.

  Examples of the alicyclic polyfunctional amine include 1,3-diaminocyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, piperazine, 2,5-dimethylpiperazine, 4-aminomethylpiperazine, and the like. .

  These polyfunctional amines may be used alone or in combination of two or more. In order to obtain a skin layer having a high salt inhibition performance, it is preferable to use an aromatic polyfunctional amine.

  The polyfunctional acid halide component is a polyfunctional acid halide having two or more reactive carbonyl groups.

  Examples of the polyfunctional acid halide include aromatic, aliphatic, and alicyclic polyfunctional acid halides.

  Examples of aromatic polyfunctional acid halides include trimesic acid trichloride, terephthalic acid dichloride, isophthalic acid dichloride, biphenyl dicarboxylic acid dichloride, naphthalene dicarboxylic acid dichloride, benzene trisulfonic acid trichloride, benzene disulfonic acid dichloride, and chlorosulfonylbenzene dicarboxylic acid. An acid dichloride etc. are mentioned.

  Examples of the aliphatic polyfunctional acid halide include propanedicarboxylic acid dichloride, butanedicarboxylic acid dichloride, pentanedicarboxylic acid dichloride, propanetricarboxylic acid trichloride, butanetricarboxylic acid trichloride, pentanetricarboxylic acid trichloride, glutaryl halide, adipoid Examples include luhalides.

  Examples of the alicyclic polyfunctional acid halide include cyclopropanetricarboxylic acid trichloride, cyclobutanetetracarboxylic acid tetrachloride, cyclopentanetricarboxylic acid trichloride, cyclopentanetetracarboxylic acid tetrachloride, cyclohexanetricarboxylic acid trichloride, and tetrahydrofuran. Examples thereof include tetracarboxylic acid tetrachloride, cyclopentane dicarboxylic acid dichloride, cyclobutane dicarboxylic acid dichloride, cyclohexane dicarboxylic acid dichloride, and tetrahydrofurandicarboxylic acid dichloride.

  These polyfunctional acid halides may be used alone or in combination of two or more. In order to obtain a skin layer having a high salt inhibition performance, it is preferable to use an aromatic polyfunctional acid halide. Moreover, it is preferable to form a crosslinked structure by using a trifunctional or higher polyfunctional acid halide as at least a part of the polyfunctional acid halide component.

  In order to improve the performance of the skin layer containing a polyamide-based resin, a polymer such as polyvinyl alcohol, polyvinyl pyrrolidone, or polyacrylic acid, a polyhydric alcohol such as sorbitol, glycerin, or the like may be copolymerized.

  The porous support for supporting the skin layer is not particularly limited as long as it can support the skin layer. The production method of the present invention is particularly effective when a porous support having an average pore diameter of 0.01 to 0.4 μm and / or an arithmetic average roughness (Ra) of the surface of 0.6 μm or more is used. The arithmetic average roughness (Ra) can be measured using, for example, VK9700 manufactured by Keyence Corporation. Examples of the material for forming the porous support include various materials such as polysulfone and polyarylethersulfone such as polyethersulfone, epoxy resin, polyimide, and polyvinylidene fluoride. From the viewpoint of thermal stability, polysulfone, polyaryl ether sulfone, and epoxy resin are preferably used.

  Hereinafter, a porous support made of an epoxy resin (hereinafter referred to as an epoxy resin porous support) will be described as an example.

  The porous epoxy resin support has pores communicating with the three-dimensional network skeleton.

  The epoxy resin porous support is formed from an epoxy resin composition containing an epoxy resin, a curing agent, and a porogen.

  Examples of the epoxy resin include bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, stilbene type epoxy resin, biphenyl type epoxy resin, bisphenol A novolak type epoxy resin, Contains cresol novolac type epoxy resin, diaminodiphenylmethane type epoxy resin, polyphenyl base epoxy resin such as tetrakis (hydroxyphenyl) ethane base, fluorene-containing epoxy resin, triglycidyl isocyanurate, heteroaromatic ring (eg triazine ring) Aromatic epoxy resins such as epoxy resins; aliphatic glycidyl ether type epoxy resins, aliphatic glycidyl ester type epoxy resins, alicyclic glycidyl esters Ether type epoxy resin, aromatic epoxy resins such as alicyclic glycidyl ester type epoxy resins. These may be used alone or in combination of two or more.

  Among these, bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F are used to form a uniform three-dimensional network skeleton and uniform pores, and to ensure chemical resistance and film strength. Type epoxy resin, bisphenol AD type epoxy resin, fluorene-containing epoxy resin, and at least one aromatic epoxy resin selected from the group consisting of triglycidyl isocyanurate; alicyclic glycidyl ether type epoxy resin, and alicyclic glycidyl It is preferable to use at least one alicyclic epoxy resin selected from the group consisting of ester-type epoxy resins. In particular, from the group consisting of bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol AD type epoxy resin, fluorene-containing epoxy resin, and triglycidyl isocyanurate having an epoxy equivalent of 6000 or less and a melting point of 170 ° C. or less. At least one aromatic epoxy resin selected; selected from the group consisting of an alicyclic glycidyl ether type epoxy resin having an epoxy equivalent of 6000 or less and a melting point of 170 ° C. or less, and an alicyclic glycidyl ester type epoxy resin It is preferable to use at least one alicyclic epoxy resin.

  Examples of the curing agent include aromatic amines (eg, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, benzyldimethylamine, dimethylaminomethylbenzene), aromatic acid anhydrides (eg, phthalic anhydride, trimellitic anhydride). Acid, pyromellitic anhydride, etc.), phenolic resins, phenol novolac resins, heteroaromatic ring-containing amines (eg, triazine ring-containing amines), etc .; aliphatic amines (eg, ethylenediamine, diethylenetriamine, triethylene) Tetramine, tetraethylenepentamine, iminobispropylamine, bis (hexamethylene) triamine, 1,3,6-trisaminomethylhexane, polymethylenediamine, trimethylhexamethylenediamine, polyether Diamine), alicyclic amines (isophoronediamine, menthanediamine, N-aminoethylpiperazine, 3,9-bis (3-aminopropyl) 2,4,8,10-tetraoxaspiro (5,5) undecane) Non-aromatic curing agents such as adducts, bis (4-amino-3-methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane, modified products thereof, and the like, and aliphatic polyamidoamines composed of polyamines and dimer acids. Can be mentioned. These may be used alone or in combination of two or more.

  Among these, in order to form a uniform three-dimensional network skeleton and uniform pores, and to ensure film strength and elastic modulus, metaphenylenediamine having two or more primary amines in the molecule, diaminodiphenylmethane, And at least one aromatic amine curing agent selected from the group consisting of diaminodiphenylsulfone; bis (4-amino-3-methylcyclohexyl) methane having two or more primary amines in the molecule, and bis (4-amino) It is preferred to use at least one alicyclic amine curing agent selected from the group consisting of (cyclohexyl) methane.

  Moreover, as a combination of an epoxy resin and a hardening | curing agent, the combination of an aromatic epoxy resin and an alicyclic amine hardening | curing agent or the combination of an alicyclic epoxy resin and an aromatic amine hardening | curing agent is preferable. These combinations increase the heat resistance of the resulting epoxy resin porous support and can be suitably used as a porous support for a composite semipermeable membrane.

  A porogen is a solvent that can dissolve an epoxy resin and a curing agent, and can cause reaction-induced phase separation after the epoxy resin and the curing agent are polymerized, such as methyl cellosolve and ethyl cellosolve. Examples include cellosolves, esters such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate, and glycols such as polyethylene glycol and polypropylene glycol. These may be used alone or in combination of two or more.

  Among these, in order to form a uniform three-dimensional network skeleton and uniform pores, methyl cellosolve, ethyl cellosolve, polyethylene glycol having a molecular weight of 600 or less, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate should be used. In particular, polyethylene glycol having a molecular weight of 200 or less and propylene glycol monomethyl ether acetate are preferably used.

  Moreover, even if it is insoluble or hardly soluble at room temperature with each epoxy resin or curing agent, a solvent in which a reaction product of the epoxy resin and the curing agent is soluble can be used as a porogen. Examples of such porogen include brominated bisphenol A type epoxy resin (“Epicoat 5058” manufactured by Japan Epoxy Resin Co., Ltd.).

  The porosity, average pore size, pore size distribution, etc. of the epoxy resin porous support are the types and blending ratios of raw materials such as epoxy resin, curing agent, porogen, etc., and the heating temperature and heating time during reaction-induced phase separation, etc. Therefore, it is preferable to select the optimum conditions by creating a phase diagram of the system in order to obtain the desired porosity, average pore size, and pore size distribution. In addition, by controlling the molecular weight, molecular weight distribution, system viscosity, crosslinking reaction rate, etc. of the crosslinked epoxy resin during phase separation, the co-continuous structure of the crosslinked epoxy resin and porogen is fixed in a specific state and stable. A porous structure can be obtained.

  Moreover, as for the mixture ratio of the hardening | curing agent with respect to an epoxy resin, it is preferable that hardening | curing agent equivalent is 0.6-1.5 with respect to 1 equivalent of epoxy groups. When the curing agent equivalent is less than 0.6, the crosslinking density of the cured product is lowered, and the heat resistance, solvent resistance and the like tend to be lowered. On the other hand, if it exceeds 1.5, unreacted curing agent remains or tends to hinder the improvement of the crosslinking density. In addition to the above-described curing agent, a curing accelerator may be added to the solution in order to obtain a target porous structure. Known curing accelerators can be used, for example, tertiary amines such as triethylamine and tributylamine, 2-phenol-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenol- Examples include imidazoles such as 4,5-dihydroxyimidazole.

  The average pore size of the epoxy resin porous support is preferably 0.01 to 0.4 μm when a skin layer containing a polyamide-based resin is formed. In order to adjust to such an average pore size, an epoxy resin is used. The porogen is preferably used in an amount of 40 to 80% by weight based on the total weight of the resin, the curing agent, and the porogen. When the amount of the porogen is less than 40% by weight, the average pore diameter tends to be too small or no pores are formed. On the other hand, when the amount of porogen exceeds 80% by weight, the average pore diameter becomes too large, and it becomes difficult to form a uniform skin layer on the porous support, or the salt rejection tends to decrease remarkably. is there.

  Moreover, as a method of adjusting the average pore diameter of the epoxy resin porous support to 0.01 to 0.4 μm, a method of using a mixture of two or more epoxy resins having different epoxy equivalents is also suitable. At that time, the difference in epoxy equivalent is preferably 100 or more.

  When the pore size distribution changes in the thickness direction of the porous support, the pore size (surface pore size) of the surface on which the skin layer is formed is important. The adjustment of the surface pore diameter of the epoxy resin porous support is the same as described above, and the surface pore diameter can be adjusted to a desired range by appropriately setting various conditions such as the total epoxy equivalent and porogen ratio and curing temperature. The surface pore diameter is preferably 0.01 to 0.4 μm, similarly to the average pore diameter.

  The arithmetic average roughness (Ra) of the surface of the porous epoxy resin support is preferably 0.01 to 3 μm, more preferably 0.03 when a skin layer containing a polyamide resin is formed. ˜1 μm. When the arithmetic average roughness of the surface is too small, the water permeability is remarkably lowered, and when the arithmetic average roughness of the surface is too large, it becomes difficult to form a skin layer having no defect. In particular, when the arithmetic average roughness of the surface is 0.6 μm or more, and further 0.8 μm or more, the conventional manufacturing method tends to cause defects in the skin layer, but when the manufacturing method of the present invention is adopted, the skin layer Defects are less likely to occur.

  The said epoxy resin porous support body is producible with the following method, for example.

  1) An epoxy resin composition containing an epoxy resin, a curing agent, and a porogen is applied onto a substrate, and then the applied epoxy resin composition is heated to three-dimensionally crosslink the epoxy resin. At that time, a co-continuous structure is formed by phase separation of the crosslinked epoxy resin and the porogen. Thereafter, the porogen is washed and removed from the obtained epoxy resin sheet and dried to prepare an epoxy resin porous support having pores communicating with the three-dimensional network skeleton. The substrate to be used is not particularly limited, and examples thereof include a plastic substrate, a glass substrate, and a metal plate.

  2) An epoxy resin composition containing an epoxy resin, a curing agent, and a porogen is applied onto a substrate, and then another substrate is placed on the applied epoxy resin composition to produce a sandwich structure. In order to provide a certain thickness between the substrates, it is preferable to provide spacers (for example, double-sided tape) at the four corners of the substrates. Then, the sandwich structure is heated to cross-link the epoxy resin three-dimensionally. At that time, a co-continuous structure is formed by phase separation of the crosslinked epoxy resin and the porogen. Thereafter, the obtained epoxy resin sheet is taken out, and the porogen is washed and removed, followed by drying to produce an epoxy resin porous support having pores communicating with the three-dimensional network skeleton. The substrate to be used is not particularly limited, and examples thereof include a plastic substrate, a glass substrate, and a metal plate, and it is particularly preferable to use a glass substrate.

  3) An epoxy resin composition containing an epoxy resin, a curing agent, and a porogen is filled in a mold having a predetermined shape, and then heated to three-dimensionally crosslink the epoxy resin to produce a cylindrical or columnar resin block. . At that time, a co-continuous structure is formed by phase separation of the crosslinked epoxy resin and the porogen. Thereafter, the surface of the block is cut with a predetermined thickness while rotating the block about the cylindrical axis or the columnar axis to produce a long epoxy resin sheet. Then, the porogen in the epoxy resin sheet is removed by washing and dried to produce an epoxy resin porous support having pores communicating with the three-dimensional network skeleton.

  The conditions for heating the epoxy resin composition are not particularly limited, and may be appropriately adjusted according to the raw material or the production method to be used. For example, the temperature is about 20 to 150 ° C., and the heating time is 10 minutes to 15 hours. Degree. Post-curing may be performed after the heat treatment in order to increase the degree of crosslinking of the crosslinked epoxy resin.

  Examples of the solvent used for removing the porogen from the obtained epoxy resin sheet include water, DMF, DMSO, THF, and mixed solvents thereof, and are appropriately selected according to the type of porogen.

  The drying conditions of the epoxy resin porous support from which the porogen has been removed are not particularly limited, but the temperature is about 40 to 120 ° C., and the drying time is about 0.2 to 3 hours.

  The thickness of the epoxy resin porous support is not particularly limited, but is about 20 to 400 μm, preferably 50 to 250 μm, from the viewpoint of strength, practical water permeability and salt-blocking property. Further, the back surface of the epoxy resin porous support may be reinforced with a woven fabric, a nonwoven fabric or the like.

  Hereafter, each process of the manufacturing method of the composite semipermeable membrane of this invention is demonstrated in detail.

  First, the porous support is subjected to a hydrophilic treatment (hydrophilic treatment step). Examples of the method for hydrophilizing the porous support include a method in which the porous support is contacted or immersed in an aqueous solution containing alcohol or the like, and a method in which the porous support is treated with atmospheric pressure plasma.

  Examples of the alcohol include, but are not limited to, ethanol, isopropyl alcohol, and t-butyl alcohol.

  The alcohol concentration in the alcohol-containing aqueous solution is not particularly limited, but is preferably 3 to 50% by weight, and more preferably 5 to 30% by weight.

  The time for making the porous support hydrophilic by contacting or immersing it in an alcohol-containing aqueous solution is not particularly limited, but is preferably 20 to 1200 seconds, more preferably 30 to 600 seconds, and still more preferably 100 to 400. Seconds.

  Thereafter, a skin layer containing a polyamide resin is formed on the surface of the porous support subjected to the hydrophilic treatment by an interfacial condensation method. The interfacial condensation method includes an aqueous solution contact step in which an aqueous solution containing a polyfunctional amine component is brought into contact with the surface of a porous support subjected to a hydrophilic treatment, and a polyfunctional acid halide component on the surface of the porous support in contact with the aqueous solution. A step of forming a skin layer containing a polyamide-based resin on the surface of the porous support by bringing the polyfunctional amine component and the polyfunctional acid halide component into contact with each other and bringing the polyfunctional amine component and polyfunctional acid halide component into contact with each other. Details of the conditions of the interfacial condensation method are described in JP-A-58-24303, JP-A-1-180208 and the like, and those known techniques can be appropriately employed.

  In the interfacial polymerization method, the concentration of the polyfunctional amine component in the aqueous solution is not particularly limited, but is preferably 0.1 to 5% by weight, more preferably 0.5 to 4% by weight. When the concentration of the polyfunctional amine component is less than 0.1% by weight, defects such as pinholes are likely to occur in the skin layer, and the salt blocking performance tends to decrease. On the other hand, when the concentration of the polyfunctional amine component exceeds 5% by weight, the film thickness becomes too thick and the permeation resistance tends to increase and the permeation flux tends to decrease.

  The concentration of the polyfunctional acid halide component in the organic solution is not particularly limited, but is preferably 0.01 to 5% by weight, more preferably 0.05 to 3% by weight. When the concentration of the polyfunctional acid halide component is less than 0.01% by weight, defects such as pinholes are likely to occur in the skin layer, and the salt blocking performance tends to decrease. On the other hand, when the concentration of the polyfunctional acid halide component exceeds 5% by weight, the film thickness becomes too thick, the permeation resistance increases, and the permeation flux tends to decrease.

  The organic solvent used in the organic solution is not particularly limited as long as it has low solubility in water, does not deteriorate the porous support, and dissolves the polyfunctional acid halide component. For example, cyclohexane, heptane, octane And saturated hydrocarbons such as nonane, and halogen-substituted hydrocarbons such as 1,1,2-trichlorotrifluoroethane. Preferred is a saturated hydrocarbon having a boiling point of 300 ° C. or lower, more preferably a boiling point of 200 ° C. or lower. These organic solvents may be used alone or in combination of two or more.

Various additives can be added to the aqueous solution or the organic solution for the purpose of facilitating film formation or improving the performance of the obtained composite semipermeable membrane. Examples of the additive include surfactants such as sodium dodecylbenzenesulfonate, sodium dodecylsulfate, and sodium laurylsulfate, sodium hydroxide that removes hydrogen halide generated by polymerization, trisodium phosphate, and triethylamine. And basic compounds, acylation catalysts, compounds having a solubility parameter of 8 to 14 (cal / cm ³ ) ^1/2 described in JP-A-8-224452, and the like.

  In the present invention, at the time of the hydrophilization treatment step and / or at the time of the aqueous solution contact step, the aqueous solution used for the hydrophilization treatment, the aqueous solution containing a polyfunctional amine component, or the porous support directly or indirectly for 20 seconds or more. It is necessary to apply the vibration. The object to which vibration is applied is not particularly limited as long as the defect factor can be removed, but is preferably the aqueous solution or the porous support itself. Thereby, bubbles contained in the aqueous solution, bubbles generated on the surface of the porous support, or foreign matters that cause defects in the skin layer can be effectively removed, and uniform and defective on the porous support. It is possible to form a skin layer having no surface.

  As a method of applying vibration, for example, when the porous support is in contact with or immersed in an alcohol-containing aqueous solution or a polyfunctional amine component-containing aqueous solution, an ultrasonic generator such as an ultrasonic cleaner is used to superimpose the aqueous solution. Examples include a method of applying ultrasonic vibration, or a method of applying ultrasonic vibration directly or indirectly to the porous support by bringing the ultrasonic vibrator into contact with the porous support itself or the transport roll of the porous support. . The vibration may be applied at the same time as contacting or immersing the porous support in the aqueous solution, or may be applied after contacting or immersing the porous support for a predetermined time.

  The time for applying the vibration needs to be 20 seconds or longer, preferably 60 seconds or longer, more preferably 100 seconds or longer. In consideration of the obtained effect and production efficiency, it is preferably 10 minutes or less. When applying ultrasonic vibration, the frequency of the ultrasonic wave is preferably 20 to 200 kHz, more preferably 35 to 100 kHz.

  After contacting an aqueous solution containing a polyfunctional amine component with an organic solution containing a polyfunctional acid halide component on the surface of the porous support, the formed film on the porous support is dried by heating at 70 ° C. or higher to form a polyamide system It is preferable to form a skin layer containing a resin. By heat-treating the formed film, its mechanical strength, heat resistance, etc. can be increased. The heating temperature is more preferably 70 to 200 ° C, particularly preferably 100 to 150 ° C. The heating time is preferably about 30 seconds to 10 minutes, more preferably about 40 seconds to 7 minutes.

  The thickness of the skin layer formed on the surface of the porous support is not particularly limited, but is usually about 0.05 to 2 μm, preferably 0.1 to 1 μm.

  The composite semipermeable membrane produced by the above method has no defect in the skin layer, and is superior in salt-blocking property compared to conventional composite semipermeable membranes.

  Moreover, in order to improve the salt-blocking property, water permeability, oxidation resistance, etc. of the composite semipermeable membrane, various conventionally known treatments may be performed.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[Evaluation and measurement method]
(Measurement of porosity and average pore diameter of epoxy resin porous support)
The porosity and average pore size of the epoxy resin porous support were measured by an auto pore 9520 type apparatus manufactured by Shimadzu Corporation by mercury porosimetry. As the average pore diameter, a median diameter under the condition of an initial pressure of 7 kPa was adopted.

(Measurement of arithmetic average roughness of epoxy resin porous support surface)
The arithmetic average roughness (Ra) of the surface of the porous epoxy resin support was measured using VK9700 manufactured by Keyence Corporation.

(Measurement of permeation flux and salt rejection)
The produced flat membrane-like composite semipermeable membrane is cut into a predetermined shape and size and set in a cell for flat membrane evaluation. An aqueous solution containing about 1500 mg / L NaCl and adjusted to pH 6.5 to 7.5 with NaOH is brought into contact with the membrane at 25 ° C. by applying a differential pressure of 1.5 MPa between the supply side and the permeation side of the membrane. The permeation rate and conductivity of the permeated water obtained by this operation were measured, and the permeation flux (m ³ / m ² · d) and the salt rejection (%) were calculated. The salt rejection was calculated in advance using a correlation (calibration curve) between NaCl concentration and aqueous solution conductivity in advance.
Salt rejection (%) = {1− (NaCl concentration in the permeate [mg / L]) / (NaCl concentration in the feed liquid [mg / L])} × 100

(Evaluation of skin layer defects)
After measuring the permeation flux and the salt rejection, an aqueous solution containing 5% by weight of a dye (direct blue, molecular weight: 993) was dropped on the skin layer of the composite semipermeable membrane to evaluate the degree of dyeing. The part dyed with the dye is the part where the porous support is exposed, indicating that the skin layer is missing.

Example 1
(Preparation of epoxy resin porous support)
11.6 g of bisphenol A type epoxy resin (Toto Kasei Co., Ltd., trade name “YD-128”, epoxy equivalent: 184-194 (g / eq)) and bisphenol A type epoxy resin (Toto Kasei Co., Ltd., trade name) 60 g of polyethylene glycol 200 (Tokyo Kasei Co., Ltd.) is added to 11.6 g of “YD-011”, epoxy equivalent: 450 to 500 (g / eq), and a rotating / revolving mixer (trade name “Awatori Nertaro” ARE -250) was stirred at 2000 rpm for 5 minutes and dissolved to obtain an epoxy resin / polyethylene glycol solution. Next, 5.2 g of bis (4-aminocyclohexyl) methane (Tokyo Kasei Co., Ltd.) is added to the epoxy resin / polyethylene glycol solution, stirred at 2000 rpm for 10 minutes using an autorotation / revolution mixer, dissolved and dissolved in an epoxy resin. A polyethylene glycol / curing agent solution was obtained.

  The epoxy resin / polyethylene glycol / curing agent solution was applied on a soda glass plate provided with double-sided tape at the four corners, and another soda glass plate was laminated thereon to obtain a sandwich structure. Thereafter, the sandwich structure was placed in a dryer and reaction-cured at 120 ° C. for 3 hours. After cooling, the epoxy resin sheet was taken out and immersed in water for 12 hours to remove polyethylene glycol. Then, it was dried in a dryer at 50 ° C. for about 4 hours to obtain an epoxy resin porous support (thickness: 150 μm, average pore size: 0.106 μm, Ra: 0.83 μm).

(Manufacture of composite semipermeable membrane)
The epoxy resin porous support is hydrophilized by immersing it in an ultrasonic cleaner (ULTRASONIC, model number CA4488Z) filled with an aqueous alcohol solution containing 30% by weight of isopropyl alcohol for 600 seconds, and further subjected to ultrasonic vibration (frequency) for 600 seconds. : 38 kHz). Next, an amine aqueous solution consisting of 3 parts by weight of m-phenylenediamine, 0.3 parts by weight of sodium lauryl sulfate, 8 parts by weight of camphorsulfonic acid, 4 parts by weight of triethylamine, 10 parts by weight of isopropyl alcohol, and 84.8 parts by weight of water was prepared. It put into the ultrasonic washing machine (ULTRASONIC, model number CA4488Z), and the surface of the said epoxy resin porous support body was made to contact the said amine aqueous solution for 120 second, applying an ultrasonic vibration (frequency: 38 kHz). After removing the excess amine aqueous solution, an isooctane solution containing 1% by weight of trimesic acid chloride was applied to the surface. Thereafter, the excess isooctane solution was removed, and further kept in a hot air dryer at 120 ° C. for 3 minutes to form a skin layer containing a polyamide-based resin, thereby producing a composite semipermeable membrane. A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1 and FIG.

Example 2
An amine aqueous solution consisting of 3 parts by weight of m-phenylenediamine, 0.2 parts by weight of sodium lauryl sulfate, 8 parts by weight of camphorsulfonic acid, 4 parts by weight of triethylamine, and 84.8 parts by weight of water was subjected to an ultrasonic cleaner (ULTRASONIC, model number CA4488Z). The composite semipermeable membrane was prepared in the same manner as in Example 1 except that the surface of the porous epoxy resin support was brought into contact with the aqueous amine solution for 20 seconds while applying ultrasonic vibration (frequency: 38 kHz). did. A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1 and FIG.

Example 3
The epoxy resin porous support is hydrophilized by immersing it in an ultrasonic cleaner (ULTRASONIC, model number CA4488Z) filled with an aqueous alcohol solution containing 30% by weight of isopropyl alcohol for 300 seconds, and further subjected to ultrasonic vibration (frequency: 38 kHz), and then a composite semipermeable membrane was prepared in the same manner as in Example 1 except that no ultrasonic vibration was applied when the surface of the epoxy resin porous support was brought into contact with the aqueous amine solution for 20 seconds. . A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1.

Example 4
(Preparation of epoxy resin porous support)
139 parts by weight of bisphenol A type epoxy resin (Japan Epoxy Resin Co., Ltd., Epicoat 828), 93.2 parts by weight of bisphenol A type epoxy resin (Japan Epoxy Resin Co., Ltd., Epicoat 1010), bis (4-aminocyclohexyl) methane 52 parts by weight and 650 parts by weight of polyethylene glycol 200 (Sanyo Kasei Co., Ltd.) were mixed to prepare an epoxy resin composition. The epoxy resin composition is filled in a cylindrical mold (outer diameter: 35 cm, inner diameter: 10.5 cm) to a height of 30 cm, then reacted and cured at 25 ° C. for 12 hours, and further reacted and cured at 130 ° C. for 18 hours (post cure). Thus, a cylindrical resin block was produced. While rotating this cylindrical resin block around the cylindrical axis, using a cutting device (manufactured by Toshiba Machine Co., Ltd.), the surface of the block is continuously sliced with a thickness of 135 μm to obtain a long epoxy resin sheet ( 150 m in length) was obtained. This epoxy resin sheet was immersed in water for 12 hours to remove polyethylene glycol. Thereafter, it was dried in a dryer at 50 ° C. for about 4 hours to obtain an epoxy resin porous support (thickness: 120 μm, porosity 45%, average pore diameter: 0.101 μm, Ra: 0.81 μm).

The epoxy resin porous support is hydrophilized by being immersed in an ultrasonic cleaner (ULTRASONIC, model number CA4488Z) filled with an alcohol aqueous solution containing 30% by weight of isopropyl alcohol for 180 seconds, and at the same time ultrasonic vibration (frequency: 38 kHz). ) Was added. Thereafter, a composite semipermeable membrane was produced in the same manner as in Example 1. A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1.

Comparative Example 1
Epoxy resin prepared in Example 1 using an aqueous amine solution comprising 3 parts by weight of m-phenylenediamine, 0.2 parts by weight of sodium lauryl sulfate, 8 parts by weight of camphorsulfonic acid, 4 parts by weight of triethylamine, and 84.8 parts by weight of water. It apply | coated to the surface of the porous support body. After removing the excess amine aqueous solution, an isooctane solution containing 1% by weight of trimesic acid chloride was applied to the surface. Thereafter, the excess isooctane solution was removed, and further kept in a hot air dryer at 120 ° C. for 3 minutes to form a skin layer containing a polyamide-based resin, thereby producing a composite semipermeable membrane. A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1 and FIG.

Comparative Example 2
The porous porous epoxy resin support produced in Example 1 was hydrophilized by dipping in an ultrasonic cleaner (ULTRASONIC, model number CA4488Z) filled with an aqueous alcohol solution containing 30% by weight of isopropyl alcohol for 600 seconds, and further for more than 10 seconds. Sonic vibration (frequency: 38 kHz) was applied. Next, an amine aqueous solution consisting of 3 parts by weight of m-phenylenediamine, 0.2 parts by weight of sodium lauryl sulfate, 8 parts by weight of camphorsulfonic acid, 4 parts by weight of triethylamine, and 84.8 parts by weight of water was subjected to an ultrasonic cleaner (ULTRASONIC). The surface of the porous epoxy resin support was brought into contact with the aqueous amine solution for 15 seconds while applying ultrasonic vibration (frequency: 38 kHz). Thereafter, a composite semipermeable membrane was produced in the same manner as in Example 1. A permeation test and evaluation of defects were performed using the produced composite semipermeable membrane. The results are shown in Table 1 and FIG.

  The composite semipermeable membrane obtained by the production method of the present invention is suitably used for the production of ultrapure water, brine or desalination of seawater, etc., and stains that cause pollution such as dyed wastewater and electrodeposition paint wastewater. Therefore, it is possible to remove / recover the pollution source or the effective substance contained therein and contribute to the closure of the waste water. Moreover, it can be used for advanced treatments such as concentration of active ingredients in food applications and removal of harmful components in water purification and sewage applications.

Claims (7)

Hydrophilic treatment process for hydrophilizing the porous support, an aqueous solution contact process for bringing an aqueous solution containing a polyfunctional amine component into contact with the surface of the porous support subjected to the hydrophilic treatment, and a porous support in contact with the aqueous solution A skin layer containing a polyamide resin is formed on the surface of a porous support by bringing an organic solution containing a polyfunctional acid halide component into contact with the surface and interfacially polymerizing the polyfunctional amine component and the polyfunctional acid halide component. In the method for producing a composite semipermeable membrane including the step of:
Applying vibration for 20 seconds or more directly or indirectly to the aqueous solution used for the hydrophilic treatment, the aqueous solution containing the polyfunctional amine component, or the porous support during the hydrophilic treatment step and / or the aqueous solution contact step. A method for producing a composite semipermeable membrane characterized by the above. The method for producing a composite semipermeable membrane according to claim 1, wherein the vibration is ultrasonic vibration. The method for producing a composite semipermeable membrane according to claim 1 or 2, wherein the hydrophilization treatment step is a step of immersing the porous support in an alcohol-containing aqueous solution. The method for producing a composite semipermeable membrane according to any one of claims 1 to 3, wherein an average pore diameter of the porous support is 0.01 to 0.4 µm. The method for producing a composite semipermeable membrane according to any one of claims 1 to 4, wherein the arithmetic average roughness (Ra) of the surface of the porous support is 0.6 µm or more. The method for producing a composite semipermeable membrane according to any one of claims 1 to 5, wherein a material for forming the porous support is an epoxy resin. A composite semipermeable membrane obtained by the production method according to claim 1.

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