JP6206043B2 - Composite semipermeable membrane and method for producing the same - Google Patents

Description

  The present invention relates to a composite semipermeable membrane having oxidation resistance and excellent separation performance for neutral molecules, and a method for producing the same.

  A composite semipermeable membrane comprising a microporous support membrane and a separation functional layer provided on the microporous support membrane is known as a water treatment separation membrane that prevents permeation of the lysate component. Most of the commercially available composite semipermeable membranes include a layer made of polyamide formed by interfacial polycondensation on a microporous support membrane as a separation functional layer.

  However, since the composite semipermeable membrane having a polyamide layer has an amide bond in the main chain, durability against an oxidizing agent is insufficient. It is also known that the desalting performance and selective separation performance of the composite semipermeable membrane having a polyamide layer are significantly deteriorated by chlorine, hydrogen peroxide, etc. used for sterilization of the membrane.

  As an example of the technology that improves the durability of the separation function layer of the membrane against the oxidant, the separation function layer is obtained by polymerizing a highly resistant silane compound and an ethylenically unsaturated compound with a wide range of raw material selectivity. Composite membranes are disclosed in Patent Document 1 and Patent Document 2. Patent Document 1 and Patent Document 2 describe that resistance to an oxidant is improved by having a separation functional layer formed by polymerizing a highly chemical-resistant silane compound and an ethylenically unsaturated compound. Yes. The composite semipermeable membrane disclosed in Patent Document 1 and Patent Document 2 is excellent in salt removal performance and oxidation resistance.

International Publication No. 2010/029985 International Publication No. 2012/077619

  Depending on the purpose of water treatment or the water to be treated, it may be desirable to remove not only salts but also neutral molecules. The present invention provides a composite semipermeable membrane with improved neutral molecule removal performance, excellent neutral molecule removal performance, and oxidation resistance, and a method for producing the same.

  In order to solve the above problems, the present invention comprises any one of the following configurations (1) to (8).

(1) comprising a microporous support membrane and a separation functional layer formed on the microporous support membrane,
The separation functional layer contains a polymer formed by condensation of a hydrolyzable group of the compound (A) and polymerization of the compound (A) and at least one of the compound (B) or (C), When the polymer does not contain the compound (B) or the compound (C), the separation functional layer contains the compound (B) or the compound (C) that is not polymerized,
A composite semipermeable membrane in which at least one of the following compounds (B) and (C) has one or more ethylenically unsaturated groups.
(A) one or more silicon compounds (B) having a silicon atom, a reactive group having an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom The compound (C) other than the compound (A) having an acidic group and the compound (2) having one or more basic groups, the compound (2) other than the compound (B) (2) Containing a polymer formed by condensation of a hydrolyzable group of the compound (A) and polymerization of the compound (A), the compound (D) and the compound (E);
The composite semipermeable membrane according to claim 1, wherein the compounds (B) and (C) contain one or more ethylenically unsaturated groups.
(3) The above (1) or (1), wherein the hydrolyzable group of the compound (A) is at least one functional group selected from the group consisting of an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, a halogen atom and a socyanate group. The composite semipermeable membrane according to (2).
(4) The composite semipermeable membrane according to any one of (1) to (2), wherein the compound (A) is represented by the following general formula (a).
Si (R1) _m (R2) _n (R3) _4-mn (a)
(R1 represents a reactive group containing an ethylenically unsaturated group. R2 represents at least one group selected from the group consisting of an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, an isocyanate group and a halogen atom. R3 represents at least one of hydrogen and an alkyl group, m and n are integers, and satisfy m + n ≦ 4, m ≧ 1, and n ≧ 1, and when m is 2 or more, R1 is the same as each other And when n is 2 or more, R2 may be the same or different from each other. When (4-mn) is 2 or more, R3 is the same as each other. Or different.)
(5) The composite semipermeable membrane according to (1) to (4), wherein the acidic group of the compound (B) is at least one selected from a carboxyl group, a sulfonic acid group, and a phosphonic acid group.
(6) The basic group of the compound (C) is at least one selected from a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, and a heterocyclic group. The composite semipermeable membrane according to (1) to (5) above.
(7) A method for producing a composite semipermeable membrane comprising a microporous support membrane and a separation functional layer,
Preparing the microporous support membrane (a);
Forming the separation functional layer on the microporous support membrane (b);
With
The step (b) of forming the separation functional layer includes:
Applying the compound (A) and a mixture of the compound (B) and the compound (C) on the microporous support membrane (b1);
A step (b2) of condensing a hydrolyzable group possessed by the compound (A);
Polymerizing compound (A) and at least one of compound (B) or (C) (b3);
Including
A method for producing a composite semipermeable membrane in which at least one of the following compounds (B) and (C) has one or more ethylenically unsaturated groups.
(A) one or more silicon compounds (B) having a silicon atom, a reactive group having an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom Compound (C) other than compound (A) having an acidic group and having one or more basic groups Compound (A) and compound (B) other than compound (B) (8) Compound (B) and (C ) Contains one or more ethylenically unsaturated groups,
In the step (b3), the compound (A), the compound (B) and the compound (C) are polymerized.
The manufacturing method as described in said (7).

  According to the present invention, by using a compound having an acidic group and a compound having a basic group, a film with improved neutral molecule removal performance can be obtained. By improving the removal performance of neutral molecules, high separation performance can be exhibited even for minute lysate components having no charge such as agricultural chemicals and pharmaceutical intermediates.

[1. Composite semipermeable membrane]
The composite semipermeable membrane described below includes a separation functional layer having a function of separating a solute from a solvent, and a microporous support membrane that supports the separation functional layer.

(1-1) Microporous support membrane The microporous support membrane provides strength to the composite semipermeable membrane by supporting the separation functional layer. The separation functional layer is provided on at least one surface of the microporous support membrane.

  A microporous support membrane can be provided on the substrate, and a separation functional layer can be provided on the microporous support membrane. It is also possible to provide a separation functional layer on the substrate and further provide a microporous support membrane on the separation functional layer. Although a plurality of separation functional layers may be provided on the microporous support membrane, it is usually sufficient to have one separation functional layer on one side. In general, for the reasons of supporting the membrane, preventing clogging, and ensuring water permeability, the layers are generally laminated in order from the coarser layer to the finer layer. Therefore, a configuration in which a microporous support membrane is provided on a substrate and a separation functional layer is further provided on the microporous support membrane is often employed.

  The pore diameter of the surface of the microporous support membrane used in the present invention is preferably in the range of 1 nm to 100 nm. When the pore diameter on the surface of the microporous support membrane is within this range, a separation functional layer with sufficiently few defects on the surface can be formed. Further, the obtained composite semipermeable membrane has a high pure water permeation flux, and the structure can be maintained without the separation functional layer falling into the support membrane pores during the pressurization operation.

  Here, the pore diameter of the surface of the microporous support membrane can be calculated from an electron micrograph. The surface of the microporous support membrane is photographed with an electron micrograph, the diameters of all the observable pores are measured, and the pore diameter can be obtained by arithmetic averaging. When the pores are not circular, a circle having an area equal to the area of the pores (equivalent circle) can be obtained by an image processing apparatus or the like, and the equivalent circle diameter can be obtained by the method of setting the diameter of the pores. As another means, the pore diameter can be determined by differential scanning calorimetry (DSC) using the principle that water in minute pores has a lower melting point than ordinary water. The details are described in literature (Ishikiriyama et al., Journal of Colloid and Interface Science, Vol. 171, p103, Academic Press Incorporated (1995)).

  The thickness of the microporous support membrane is preferably in the range of 1 μm to 5 mm, and more preferably in the range of 10 μm to 100 μm. If the thickness is small, the strength of the microporous support membrane tends to decrease, and as a result, the strength of the composite semipermeable membrane tends to decrease. When the thickness is large, it becomes difficult to handle when the microporous support membrane and the composite semipermeable membrane obtained therefrom are bent. In order to increase the strength of the composite semipermeable membrane, the microporous support membrane may be reinforced with cloth, nonwoven fabric, paper, or the like. The preferable thickness of these reinforcing materials is usually 50 μm or more and 150 μm or less.

  The material used for the microporous support membrane is not particularly limited. For example, homopolymers or copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulose polymer, vinyl polymer, polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfone, and polyphenylene oxide can be used. These polymers can be used alone or blended. Among the above, examples of the cellulose polymer include cellulose acetate and cellulose nitrate. Preferred examples of the vinyl polymer include polyethylene, polypropylene, polyvinyl chloride, polyacrylonitrile and the like. Of these, homopolymers and copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulose acetate, cellulose nitrate, polyvinyl chloride, polyacrylonitrile, polyphenylene sulfide, and polyphenylene sulfide sulfone are preferable. Furthermore, among these materials, it is particularly preferable to use polysulfone or polyethersulfone which has high chemical stability, mechanical strength and thermal stability and is easy to mold.

(1-2) Separation Functional Layer The thickness of the separation functional layer in the composite semipermeable membrane of the present invention is preferably in the range of 5 nm to 500 nm. The lower limit is more preferably 10 nm. More preferably, the upper limit is 200 nm. The separation functional layer having a reduced thickness can improve water permeability.

  The separation functional layer contains a polymer formed by condensation of the hydrolyzable group of the compound (A) and polymerization of the compound (A) and at least one of the compound (B) or the compound (C). The compound (B) or (C) may be contained in the separation functional layer not as a polymer but as a non-polymerized compound. That is, the compound (B) or the compound (C) may be a compound having no polymerizable group, and the compound (B) or (C) having no polymerizable group is not polymerized in the separation functional layer. It may be contained.

  The compound (A) is a silicon compound having a silicon atom, a reactive group having an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom. The compound (B) is a compound having one or more acidic groups and other than the compound (A). Compound (B) may further have one or more ethylenically unsaturated groups. The compound (C) has one or more basic groups, is a compound other than the compound (A), and is a compound other than the compound (B). Compound (C) may further have one or more ethylenically unsaturated groups.

As described above, the compound (B) and the compound (C) coexist in the separation functional layer. In the separation functional layer, the compounds (B) and (C) have a high hydrophilicity derived from an acidic group or a basic group, and form an aggregated structure due to the high hydrophilicity when used alone. . When these compounds (B) and (C) coexist, the acidic group and the basic group are neutralized from each other, and the acidic group and the basic group are capped with each other by forming a salt between organic substances, thereby reducing the hydrophilicity. To do. Thereby, formation of the aggregate structure which originated in high hydrophilicity is suppressed.
When the compound (B) or the compound (C) is a salt of an organic substance and an inorganic substance, salt recombination occurs to form a salt between the organic substances, and the aggregation structure is similarly suppressed.
Since the aggregation structure site becomes pores, the separation functional layer can be densified by suppressing the formation of the aggregation structure. This densification realizes higher neutral molecule removal performance than conventional siloxane compound-containing composite semipermeable membranes.

  Residual agricultural chemicals and pharmaceuticals are examples of neutral molecules that are desired to be removed from the solution. Residual pesticides and pharmaceuticals have a large effect on the living body even in trace amounts, and therefore, a membrane having a high removal performance with respect to neutral molecules is suitably used for water treatment.

  Moreover, moderate water permeability is implement | achieved by the acidic group of a compound (B), and the basic group of a compound (C) because a isolation | separation functional layer contains a compound (B) and a compound (C).

  First, the compound (A) in which a reactive group having an ethylenically unsaturated group and a hydrolyzable group are bonded to a silicon atom will be described.

  The reactive group having an ethylenically unsaturated group is directly bonded to the silicon atom. Examples of such reactive groups include vinyl groups, allyl groups, methacryloxyethyl groups, methacryloxypropyl groups, acryloxyethyl groups, acryloxypropyl groups, and styryl groups. From the viewpoint of polymerizability, a methacryloxypropyl group, an acryloxypropyl group, and a styryl group are preferable.

  Examples of the hydrolyzable group include an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, an aminohydroxy group, a halogen atom and an isocyanate group. As an alkoxy group, a C1-C10 thing is preferable, More preferably, it is a C1-C2 thing. The alkenyloxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, and further preferably 3 carbon atoms. As the carboxy group, those having 2 to 10 carbon atoms are preferable, and those having 2 carbon atoms, that is, an acetoxy group is preferable. Examples of the ketoxime group include a methyl ethyl ketoxime group, a dimethyl ketoxime group, and a diethyl ketoxime group. The aminohydroxy group is one in which an amino group is bonded to a silicon atom via an oxygen atom via oxygen. Examples of such include dimethylaminohydroxy group, diethylaminohydroxy group, and methylethylaminohydroxy group. As the halogen atom, a chlorine atom is preferably employed.

  In forming the separation functional layer, a compound in which a part of the hydrolyzable group is hydrolyzed to have a silanol structure can be used.

As the compound (A), the following general formula (b):
Si (R1) _m (R2 ² ) _n (R3 ³ ) _4-mn (a)
(R1 represents a reactive group containing an ethylenically unsaturated group. R2 represents at least one group selected from the group consisting of an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, an isocyanate group, and a halogen atom. R3 represents at least one of hydrogen and an alkyl group, m and n are integers, and satisfy m + n ≦ 4, m ≧ 1, and n ≧ 1, and when m is 2 or more, R1 is the same as each other And when n is 2 or more, R2 may be the same or different from each other. When (4-mn) is 2 or more, R3 is the same as each other. Or different.)
It is preferable that it is represented by these.

  R1 is a reactive group containing an ethylenically unsaturated group, as described above. R2 is a hydrolyzable group, which is as described above. The number of carbon atoms of the alkyl group to be R3 is preferably 1 or more and 10 or less, and more preferably 1 or 2.

  As the hydrolyzable group, an alkoxy group is preferably used in forming the separation functional layer because the reaction solution has a viscosity and pot life suitable for film formation.

  Such compounds (A) include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, styrylethyltrimethoxysilane, styrylethyltriethoxy. Silane, methacryloxypropylmethyldimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropyltriethoxysilane, acryloxymethyltrimethoxysilane, acryloxypropyltrimethoxysilane, (acryloxymethyl) An example is phenethyltrimethoxysilane.

In addition to the compound (A), a reactive group having an ethylenically unsaturated group is not included, but a compound having a hydrolyzable group can also be used. Such compounds have the following general formula (c):
Si (R4) _a (R5) _4-a ... General formula (c)
(R4 represents at least one group selected from the group consisting of an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, a halogen atom and an isocyanate group. R5 represents at least one of a hydrogen atom and an alkyl group. Is an integer satisfying 1 ≦ a ≦ 4, when a is 2 or more, R4 may be the same or different from each other, and when (4-a) is 2 or more, R5 is the same as each other. It may or may not be.)
Examples of such silicon compounds include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methylenebistrimethoxysilane, methylenebistriethoxysilane, ethylenebistrimethoxysilane, and ethylenebistriethoxy. Examples include silane, phenylbistrimethoxysilane, and phenylbistriethoxysilane.

Next, the compound (B) which has an acidic group and may have a reactive group having an ethylenically unsaturated group will be described.
The compound (B) is an alkali-soluble compound having an acidic group in order to increase the selective permeability of water and increase the salt rejection when the composite semipermeable membrane is used for separation of an aqueous solution. The compound (B) is preferably an organic compound. The compound (B) preferably has at least one acidic group selected from a carboxyl group, a sulfonic acid group, and a phosphonic acid group. That is, the compound (B) preferably includes carboxylic acid, phosphonic acid, phosphoric acid and sulfonic acid. Compound (B) may exist in any state of an acid, an ester compound, and a metal salt. These compounds (B) may contain two or more acidic groups, and among them, compounds containing 1 to 2 acidic groups are preferable.

  Furthermore, the compound (B) may have an ethylenically unsaturated group having addition polymerizability. Examples of the compound having an ethylenically unsaturated group include ethylene, propylene, methacrylic acid, acrylic acid, styrene, and derivatives thereof.

  Among the above compounds (B), as the compound having a carboxylic acid group, maleic acid, maleic anhydride, acrylic acid, methacrylic acid, 2- (hydroxymethyl) acrylic acid, 4- (meth) acryloyloxyethyl trimellit Acid and corresponding anhydride, 10-methacryloyloxydecylmalonic acid, N- (2-hydroxy-3-methacryloyloxypropyl) -N-phenylglycine, 4-vinylbenzoic acid, formic acid, acetic acid, propanoic acid, butanoic acid, Pentanoic acid, hexanoic acid, 2-methylpropanoic acid, 2,2-dimethylpropanoic acid, 2-methylbutanoic acid, 3-methylbutanoic acid, oleic acid, linoleic acid, linolenic acid, hydroxybenzoic acid, benzenecarboxylic acid, phthalic acid, 3-phenylacrylic acid, propanedioic acid, butanedioic acid, pyruvic acid and the like These salts are exemplified.

  Among the compounds (B), the compounds having a phosphonic acid group include vinylphosphonic acid, 4-vinylphenylphosphonic acid, 4-vinylbenzylphosphonic acid, 2-methacryloyloxyethylphosphonic acid, 2-methacrylamidoethylphosphonic. Acid, 4-methacrylamide-4-methyl-phenyl-phosphonic acid, 2- [4- (dihydroxyphosphoryl) -2-oxa-butyl] -acrylic acid and 2- [2-dihydroxyphosphoryl) -ethoxymethyl] -acrylic Acid-2,4,6-trimethyl-phenyl ester, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, decylphosphonic acid phosphonic acid, 1-methylethylphosphonic acid, 1-methylpropylphosphonic acid, 2- Methylpropylphosphonic acid, 1-hydroxyethane -1,1-diphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, 4-methoxyphenylphosphonic acid, methylenediphosphonic acid, 1,2-ethylenediphosphonic acid, 1,8-octanediphosphonic acid, and salts thereof Is exemplified.

Among the compounds having a phosphate ester among the above compounds (B), 2-methacryloyloxypropyl monohydrogen phosphate, 2-methacryloyloxypropyl dihydrogen phosphate, 2-methacryloyloxyethyl monohydrogen phosphate and 2- Methacryloyloxyethyl dihydrogen phosphate, 2-methacryloyloxyethyl-phenyl-hydrogen phosphate, 10-methacryloyloxydecyl-dihydrogen phosphate, mono- (1-acryloyl-piperidin-4-yl) phosphate, 6 -(Methacrylamide) hexyl dihydrogen phosphate, methyl phosphate, ethyl phosphate, propyl phosphate, butyl phosphate, decyl phosphate, phenyl phosphate, 1-naphthyl phosphate, 2-naphthyl phosphate, dimethyl phosphate, Examples include ethyl methyl phosphate and salts thereof.

  Among the above compounds (B), examples of the compound having a sulfonic acid group include vinyl sulfonic acid, allyl sulfonic acid, 3- (acryloyloxy) propane-1-sulfonic acid, and 3- (methacryloyloxy) propane-1-sulfone. Acid, 4-methacrylamidobenzenesulfonic acid, 1,3-butadiene-1-sulfonic acid, 2-methyl-1,3-butadiene-1-sulfonic acid, 4-vinylphenylsulfonic acid, 3- (methacrylamide) propyl Sulfonic acid, methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 2-propanesulfonic acid, decanesulfonic acid, benzenesulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, p-Toluenesulfonic acid, 4-hydroxy-1-naphthalene Phosphate, 5-hydroxy-1-naphthalenesulfonic acid, 1,2-ethanedisulfonic acid, 1,3-propane disulfonic acid, 1,8-octane dicarboxylic acid and salts thereof are exemplified.

Next, the compound (C) which has a basic group and may have a reactive group having an ethylenically unsaturated group will be described.
The compound (C) is an acid-soluble compound having a basic group in order to increase the selective permeability of water and increase the salt rejection when the composite semipermeable membrane is used for separation of an aqueous solution or the like. The compound (C) is preferably an organic compound. The basic group here means a functional group having a base dissociation constant (pKb) in water smaller than the acid dissociation constant (pKa) of the conjugate acid. Preferable basic group structures include, for example, a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, and a heterocyclic group. These compounds (C) may contain two or more basic groups, and among them, compounds containing 1 to 2 basic groups are preferred.

  Furthermore, the compound (C) may have an ethylenically unsaturated group having addition polymerizability. Examples of the compound having an ethylenically unsaturated group include ethylene, propylene, methacrylic acid, acrylic acid, styrene, and derivatives thereof.

Examples of the compound having at least one basic group and at least one ethylenically unsaturated group include the following general formulas such as allylamine, N-methylallylamine, 4-aminostyrene, N, N-dimethylallylamine, and 4-vinylbenzylamine. The amine compound represented by (1), dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminomethyl methacrylate, dimethylaminomethyl acrylate, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate, dimethylaminobutyl methacrylate, dimethylaminobutyl acrylate, Diethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminopropyl methacrylate, diethylaminopropyl acrylate, di Tilaminobutyl methacrylate, diethylaminobutyl acrylate, dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, N-hydroxy (meth) acrylamide, 1-vinylpyridine, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylimidazole, 4-vinylimidazole, 5-vinylimidazole, vinylpyrrolidone, 2-vinyloxazole, 2-vinyl-2-oxazoline, methylamine, ethylamine , Propylamine, butylamine, laurylamine, isopropylamine, isobutylamine, 2-ethylhexylamine, dimethylamine, diethylamine, dipropyl Amine, dibutylamine, dilaurylamine, diisopropylamine, diisobutylamine, di-2-ethylhexylamine, N-methylbutylamine, N-ethylbutylamine, N-ethylhexylamine, N-ethyllaurylamine, trimethylamine, triethylamine, tripropylamine , Tributylamine, trilaurylamine, triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, N, N-dimethyllaurylamine, cyclohexylamine, 2-methylcyclohexylamine, aniline, benzylamine, 4-methylbenzylamine N, N-dicyclohexylamine, N, N-di-2-methylcyclohexylamine, dibenzylamine, N, N-di-4-methylbenzylamine, N-cyclo Hexyl-2-ethylhexylamine, N-cyclohexylbenzylamine, N-stearylbenzylamine, tribenzylamine, ethanolamine, diethanolamine, propanolamine, isopropanolamine, butanolamine, triethanolamine, N, N-dimethylethanolamine, N -Methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-propylethanolamine, N-isopropylethanolamine, N-butylethanolamine, N-cyclohexyl-N-methylaminoethanol, N-benzyl-N- Propylaminoethanol, N-hydroxyethylpyrrolidine, N-hydroxyethylpiperazine, N-hydroxyethylmorpholine, ethylenediamine, N-methyl Ruethylenediamine, N, N′-dimethylethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, N, N-dimethyl-1,3-propane Diamine, N-cyclohexyl-1,3-propanediamine, N-decyl-1,3-propanediamine, N-isotridecyl-1,3-propanediamine, N, N′-dimethylpiperazine, N-methoxyphenylpiperazine, N -Methylpiperidine, N-ethylpiperidine,
Pyridine, 1-methylpyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 1-ethylpyridine, 1-decylpyridine,
Imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 5-methylimidazole 1-ethylimidazole, 1-decylimidazole, 1-propylimidazole, 1-isopropylimidazole,
1-oxazoline, 2-methyloxazole, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-isopropyl-2-oxazoline, 4,5-dihydro-2- Phenyloxazole, 4,4-dimethyl-2-oxazoline, 2,4,4-trimethyl-2-oxazoline, 2,4,5-trimethyloxazole, 2,2′-bis (2-oxazoline), 1,3- Bis (4,5-dihydro-2-oxazolyl) benzene and salts thereof,
And tetraethylammonium chloride, tetramethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride,
Triethylmethylammonium chloride, trimethylethylammonium chloride, dimethyldiethylammonium chloride, 2-hydroxyethyltrimethylammonium chloride, 3-hydroxypropyltrimethylammonium chloride, N, N-dimethylpyrrolidinium chloride, N, N-dimethylpiperidinium chloride N, N-dimethylmorpholinium chloride,
1,3-dimethylimidazolium chloride, 1,2-dimethyl-3-ethylimidazolium chloride N-methylpyridinium chloride, N-ethylpyridinium chloride, N-propylpyridinium chloride, N-butylpyridinium chloride,
Is exemplified.

  In the composite semipermeable membrane of the present invention, in order to form a separation functional layer, in addition to the silicon compound of (A), the compound (B) other than (A) having one or more acidic groups, and basic A compound (C) other than (A) and (B) having a group is used. In addition to condensing hydrolyzable groups, it is necessary to increase the molecular weight of these compounds by polymerizing compounds having ethylenically unsaturated groups.

When the silicon compound of (A) is condensed alone, the bond of the crosslinking chain concentrates on the silicon atom, and the density difference between the silicon atom periphery and the part away from the silicon atom increases, so the pore size in the separation functional layer Tends to be non-uniform. On the other hand, in addition to the high molecular weight and crosslinking of the silicon compound itself of (A), at least one of the compound (A) and the compound (B) or (C) is copolymerized to crosslink by condensation of hydrolyzable groups. The points and the crosslinking points due to the polymerization of the ethylenically unsaturated groups are moderately dispersed. By appropriately dispersing the crosslinking points in this manner, a separation functional layer having a uniform pore diameter is formed, and a composite semipermeable membrane having a balance between water permeability and removal performance can be obtained. At this time, since the compound having an ethylenically unsaturated group has a low molecular weight, it may be eluted when the composite semipermeable membrane is used and may cause a decrease in membrane performance.
That is, the separation functional layer contains a polymer of the compound (A) and at least one of the compound (B) or (C), and contains a polymer crosslinked by a condensation reaction via the functional group of the compound (A). To do.

  In the present invention, it is important that the compound (B) and the compound (C) coexist. Compounds (B) and (C) have a high hydrophilicity derived from an acidic group or a basic group, and when used alone, form an aggregate structure due to the high hydrophilicity. When (B) and (C) are allowed to coexist, the acidic group and the basic group are neutralized with each other, and the acidic group and the basic group are capped with each other by forming a salt between organic substances, thereby reducing the hydrophilicity. Thereby, formation of the aggregate structure which originated in high hydrophilicity is suppressed. When compound (B) or compound (C) is a salt with an inorganic substance, salt recombination occurs to form a salt between organic substances, and the aggregate structure is similarly suppressed.

(1-3) Substrate From the viewpoints of the strength and dimensional stability of the composite semipermeable membrane, the composite semipermeable membrane main body may have a substrate. As the base material, it is preferable to use a fibrous base material in terms of strength, unevenness forming ability and fluid permeability.

  As a base material, both a long fiber nonwoven fabric and a short fiber nonwoven fabric can be used preferably. In particular, since the long fiber nonwoven fabric has excellent film-forming properties, when the polymer solution is cast, the solution penetrates through the permeation, the porous support layer peels off, and Can suppress the film from becoming non-uniform due to fluffing of the substrate and the like, and the occurrence of defects such as pinholes. In addition, since the base material is made of a long-fiber non-woven fabric composed of thermoplastic continuous filaments, compared to short-fiber non-woven fabrics, it suppresses the occurrence of non-uniformity and film defects caused by fiber fluffing during casting of a polymer solution. be able to. Furthermore, since the composite semipermeable membrane is subjected to tension in the film forming direction when continuously formed, it is preferable to use a long fiber nonwoven fabric having excellent dimensional stability as a base material.

  In the long-fiber nonwoven fabric, in terms of moldability and strength, it is preferable that the fibers in the surface layer on the side opposite to the microporous support membrane have a longitudinal orientation than the fibers in the surface layer on the microporous support membrane side. According to such a structure, the high effect which prevents a film tear etc. is implement | achieved by maintaining intensity | strength. When unevenness is imparted to the composite semipermeable membrane by embossing or the like, if the base material is a long-fiber nonwoven fabric, the moldability of the laminate including the microporous support film and the base material is also improved, and the composite semipermeable membrane It is preferable because the uneven shape on the surface is stabilized.

  More specifically, the fiber orientation degree in the surface layer on the side opposite to the microporous support membrane of the long fiber nonwoven fabric is preferably 0 ° or more and 25 ° or less, and in the surface layer of the microporous support membrane. The orientation degree difference from the fiber orientation degree is preferably 10 ° or more and 90 ° or less.

  The manufacturing process of the composite semipermeable membrane and the manufacturing process of the element include a heating process, but a phenomenon occurs in which the porous support layer or the separation functional layer contracts due to the heating. In particular, the shrinkage is remarkable in the width direction where no tension is applied in continuous film formation. Since shrinkage causes problems in dimensional stability and the like, a substrate having a small rate of thermal dimensional change is desired. In the nonwoven fabric, if the difference between the fiber orientation degree on the surface layer opposite to the porous support layer and the fiber orientation degree on the surface layer of the microporous support film is 10 ° or more and 90 ° or less, the change in the width direction due to heat is suppressed. It is also preferable because it can be performed.

  Here, the fiber orientation degree is an index indicating the fiber orientation of the nonwoven fabric substrate constituting the microporous support membrane. Specifically, the fiber orientation degree is an average value of angles between the film forming direction (machine direction: the longitudinal direction of the nonwoven fabric) and the longitudinal direction of the fibers constituting the nonwoven fabric substrate. That is, if the longitudinal direction of the fiber is parallel to the film forming direction, the fiber orientation degree is 0 °. If the longitudinal direction of the fiber is perpendicular to the film forming direction, that is, parallel to the width direction of the nonwoven fabric, the degree of orientation of the fiber is 90 °. Therefore, the fiber orientation degree is closer to 0 °, the longer is the vertical orientation, and the closer to 90 ° is the lateral orientation.

  The degree of fiber orientation is measured as follows. First, 10 small piece samples are randomly collected from the nonwoven fabric. Next, the surface of the sample is photographed at 100 to 1000 times with a scanning electron microscope. In the photographed image, 10 fibers are selected for each sample, and the angle in the longitudinal direction of the fibers is measured when the longitudinal direction (longitudinal direction and film forming direction) of the nonwoven fabric is 0 °. The longitudinal direction of the nonwoven fabric coincides with the film forming direction of the porous support layer. Thus, the angle is measured for a total of 100 fibers per nonwoven fabric. An average value is calculated for the angles of the 100 fibers thus obtained. The value obtained by rounding off the first decimal place of the obtained average value is the fiber orientation degree.

[2. Production method]
The composite semipermeable membrane described above can be manufactured by a manufacturing method including a step of forming a separation functional layer on a microporous support membrane.

  The step of forming the separation functional layer on the microporous support membrane means that at least one of the compound (A), the compound (B) and the compound (C) via the ethylenically unsaturated group on the microporous support membrane. The step of polymerizing includes a step of performing condensation via a hydrolyzable group of compound (A) on the microporous support membrane.

  Either the step of performing polymerization or the step of performing condensation may be performed first or in parallel.

    Specifically, the step of forming the separation functional layer further includes a step of applying a reaction liquid containing the compounds (A), (B), and (C) to the microporous support membrane and a step of removing the solvent. May be.

Below, the manufacturing process of a separation functional layer is demonstrated more concretely.
First, the reaction solution containing the compounds (A), (B) and (C) is brought into contact with the microporous support membrane. Such a reaction solution usually contains a solvent. Such a solvent is not particularly limited as long as it does not destroy the microporous support membrane and dissolves the compounds (A), (B) and (C), and a polymerization initiator added as necessary.
In the production method of the present invention, (A) the content of the silicon compound in which the reactive group having an ethylenically unsaturated group and the hydrolyzable group are directly bonded to the silicon atom is 100 parts by weight of the solid content contained in the reaction solution. The amount is preferably 10 parts by weight or more, more preferably 20 parts by weight to 50 parts by weight. Here, the solid content contained in the reaction solution is the final content of the composite semipermeable membrane obtained by the production method of the present invention, excluding the solvent and the distilling component among all the components contained in the reaction solution. Refers to a component contained as a separation functional layer. When the amount of the silicon compound (A) is small, the degree of crosslinking tends to be insufficient, so that there is a possibility that problems such as elution of the separation functional layer during membrane filtration and deterioration of separation performance may occur. When the content of the compound (A) is in these ranges, the resulting separation functional layer has a high degree of crosslinking, and thus membrane filtration can be performed stably without the separation functional layer eluting.

The content of the compound (B) having an acidic group and optionally having an ethylenically unsaturated group is preferably 90 parts by weight or less with respect to 100 parts by weight of the solid content contained in the reaction solution. More preferably, it is 5 to 80 parts by weight.
The content of the compound (C) that has a basic group and may have an ethylenically unsaturated group is 90 parts by weight or less with respect to 100 parts by weight of the solid content contained in the reaction solution. Preferably, it is 5 to 80 parts by weight.

  Next, a method for forming a separation functional layer on a porous support membrane in the method for producing a composite semipermeable membrane of the present invention will be described.

  As a method for forming the separation functional layer, for example, a step of applying a reaction liquid containing compounds (A), (B) and (C), a step of removing the solvent, a step of polymerizing ethylenically unsaturated groups, A method comprising a step of condensing a hydrolyzable group can be mentioned. Each process can be executed in this order. In the step of polymerizing the ethylenically unsaturated group, the hydrolyzable group may condense at the same time.

  First, the reaction liquid containing the compounds (A), (B) and (C) is brought into contact with the microporous support membrane. Such a reaction solution is usually a solution containing a solvent, but such a solvent does not destroy the microporous support membrane, and the compounds (A), (B) and (C), and a polymerization which is added as necessary. The initiator is not particularly limited as long as it dissolves the initiator. To this reaction liquid, water of 1 to 10 times mol amount, preferably 1 to 5 times mol amount of the silicon compound (A) is added together with an inorganic acid or an organic acid, and the silicon compound (A). It is preferable to promote hydrolysis.

  As the solvent for the reaction solution, water, an alcohol-based organic solvent, an ether-based organic solvent, a ketone-based organic solvent, and a mixture thereof are preferable. For example, as an alcohol organic solvent, methanol, ethoxymethanol, ethanol, propanol, butanol, amyl alcohol, cyclohexanol, methylcyclohexanol, ethylene glycol monomethyl ether (2-methoxyethanol), ethylene glycol monoacetate, diethylene glycol monomethyl ether, Examples include diethylene glycol monoacetate, propylene glycol monoethyl ether, propylene glycol monoacetate, dipropylene glycol monoethyl ether, and methoxybutanol. Examples of ether organic solvents include methylal, diethyl ether, dipropyl ether, dibutyl ether, diamyl ether, diethyl acetal, dihexyl ether, trioxane, dioxane and the like. As ketone organic solvents, acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl cyclohexyl ketone, diethyl ketone, ethyl butyl ketone, trimethylnonanone, acetonitrile acetone, dimethyl oxide, phorone, cyclohexanone, dye Acetone alcohol etc. are mentioned.

  The amount of the solvent added is preferably 50% by weight to 99% by weight and more preferably 80% by weight to 99% by weight with respect to the total weight of the reaction solution. If the amount of the solvent added is too large, defects tend to occur in the membrane, and if it is too small, the water permeability of the resulting composite semipermeable membrane tends to be low.

  The contact between the microporous support membrane and the reaction solution is preferably performed uniformly and continuously on the surface of the microporous support membrane. Specifically, for example, a method of coating the reaction solution on the microporous support film using a coating apparatus such as a spin coater, a wire bar, a flow coater, a die coater, a roll coater, or a spray. Moreover, the method of immersing a microporous support membrane in a reaction liquid can be mentioned.

  When immersed, the contact time between the microporous support membrane and the reaction solution is preferably in the range of 0.5 minutes to 10 minutes, and more preferably in the range of 1 minute to 3 minutes. After the reaction solution is brought into contact with the microporous support membrane, it is preferable to sufficiently drain the liquid so that no droplets remain on the membrane. By sufficiently draining the liquid, it is possible to prevent the remaining portion of the liquid droplet from becoming a film defect after the film is formed and deteriorating the film performance. Liquid draining can be performed by holding the microporous support membrane in contact with the reaction liquid in the vertical direction to allow the excess reaction liquid to flow down naturally or by blowing air such as nitrogen from an air nozzle to forcibly drain the liquid. Or the like can be used. In addition, after draining, the membrane surface can be dried to remove a part of the solvent in the reaction solution.

  The step of condensing the hydrolyzable group of silicon is carried out by bringing the reaction solution into contact with the microporous support membrane and then performing a heat treatment. The heating temperature at this time is preferably lower than the temperature at which the microporous support membrane melts. In order to allow the condensation reaction to proceed rapidly, it is usually preferred to heat at 0 ° C. or higher, more preferably 20 ° C. or higher. The condensation reaction temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower. If the reaction temperature is 0 ° C. or higher, the hydrolysis and condensation reaction proceed rapidly, and if it is 150 ° C. or lower, the hydrolysis and condensation reaction are easily controlled. Further, by adding a catalyst that promotes hydrolysis or condensation, the reaction can proceed even at a lower temperature. Furthermore, in the present invention, the heating condition and the humidity condition are selected so that the separation functional layer has pores, and the condensation reaction is appropriately performed.

  As a polymerization method of the ethylenically unsaturated groups of the compounds (A), (B), and (C), heat treatment, electromagnetic wave irradiation, electron beam irradiation, and plasma irradiation can be performed. Here, electromagnetic waves include ultraviolet rays, X-rays, γ-rays and the like. The polymerization method may be appropriately selected as appropriate, but polymerization by electromagnetic wave irradiation is preferred from the viewpoint of running cost, productivity and the like. Among electromagnetic waves, ultraviolet irradiation is more preferable from the viewpoint of simplicity. When the polymerization is actually performed using ultraviolet rays, these light sources need not selectively generate only light in the ultraviolet wavelength region, but may be any material that contains electromagnetic waves in the ultraviolet wavelength region. However, from the viewpoint of shortening the polymerization time and ease of controlling the polymerization conditions, it is preferable that the intensity of these ultraviolet rays is higher than electromagnetic waves in other wavelength regions.

  Electromagnetic waves can be generated from halogen lamps, xenon lamps, UV lamps, excimer lamps, metal halide lamps, rare gas fluorescent lamps, mercury lamps, and the like. The energy of the electromagnetic wave is not particularly limited as long as it can be polymerized, but the ultraviolet thin film formation property is particularly high. Such ultraviolet rays can be generated by a low-pressure mercury lamp or an excimer laser lamp. The thickness and form of the separation functional layer according to the present invention may vary greatly depending on the respective polymerization conditions. In the case of polymerization using electromagnetic waves, the thickness and form of the separation functional layer according to the present invention may vary greatly depending on the wavelength of electromagnetic waves, the intensity, the distance to the irradiated object, and the processing time. Therefore, these conditions need to be optimized as appropriate.

  For the purpose of increasing the polymerization rate, it is preferable to add a polymerization initiator, a polymerization accelerator or the like during the formation of the separation functional layer. Here, the polymerization initiator and the polymerization accelerator are not particularly limited, and are appropriately selected according to the structure of the compound to be used, the polymerization technique, and the like.

  The polymerization initiator is exemplified below. As an initiator for polymerization by electromagnetic waves, benzoin ether, dialkylbenzyl ketal, dialkoxyacetophenone, acylphosphine oxide or bisacylphosphine oxide, α-diketone (for example, 9,10-phenanthrenequinone), diacetylquinone, furylquinone, anisylquinone, 4,4′-dichlorobenzylquinone and 4,4′-dialkoxybenzylquinone, and camphorquinone are exemplified. Initiators for thermal polymerization include azo compounds (eg, 2,2′-azobis (isobutyronitrile) (AIBN) or azobis- (4-cyanovaleric acid), or peroxides (eg, dibenzoyl peroxide). , Dilauroyl peroxide, tert-butyl peroctanoate, tert-butyl perbenzoate or di- (tert-butyl) peroxide), aromatic diazonium salts, bissulfonium salts, aromatic iodonium salts, aromatic sulfonium salts, Examples include potassium sulfate, ammonium persulfate, alkyllithium, cumylpotassium, sodium naphthalene, distyryl dianion, and benzopinacol and 2,2'-dialkylbenzopinacol are particularly preferred as initiators for radical polymerization.

  Peroxides and α-diketones are preferably used in combination with aromatic amines to accelerate the initiation of polymerization. This combination is also called a redox system. Examples of such systems include benzoyl peroxide or camphorquinone and amines (eg, N, N-dimethyl-p-toluidine, N, N-dihydroxyethyl-p-toluidine, ethyl p-dimethyl-aminobenzoate). Ester or a derivative thereof). Furthermore, a system containing a peroxide in combination with ascorbic acid, barbiturate or sulfinic acid as a reducing agent is also preferable in order to accelerate the initiation of polymerization.

  Subsequently, when this is heat-treated at about 100 to 200 ° C. for about 10 minutes to 3 hours, a covalent bond is formed between the compounds (A) by a polycondensation reaction. Thus, the composite semipermeable membrane of the present invention in which the separation functional layer is formed on the surface of the microporous support membrane can be obtained. Although the heating temperature depends on the material of the microporous support membrane, if it is too high, dissolution occurs and the pores of the microporous support membrane are blocked, resulting in a decrease in the amount of water produced in the composite semipermeable membrane. On the other hand, if the heating temperature is too low, the progress of the polycondensation reaction will be insufficient, and as a result, the formation of covalent bonds will be insufficient, so that the salt removal rate will decrease due to elution of the separation functional layer. Become.

  In addition, as above-mentioned, the superposition | polymerization process of the reactive group which has an ethylenically unsaturated group may be performed before the covalent bond formation process between hydrolysable groups, and may be performed after it.

  The composite semipermeable membrane thus obtained can be used as it is, but before use, it is preferable to hydrophilize the surface of the membrane with, for example, an alcohol-containing aqueous solution or an alkaline aqueous solution.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited thereby.

  In the following examples, the initial performance of the solute removal rate of the composite semipermeable membrane is calculated by the following formula (I).

Solute removal rate (%) = {1- (solute concentration of permeate) / (solute concentration of feed solution)} × 100 (I)
Example 1
A 15.7 wt% dimethylformamide solution of polysulfone was cast on a polyethylene terephthalate nonwoven fabric at a thickness of 200 μm at room temperature (25 ° C.). After casting, the substrate was immediately immersed in pure water and allowed to stand for 5 minutes to prepare a microporous support membrane. The microporous support membrane thus obtained had a surface pore size of 21 nm and a thickness of 150 μm.

  In a 50% by weight aqueous solution of isopropyl alcohol, 3-acryloxypropyltrimethoxysilane corresponding to the compound (A) is 80 mM, sodium 4-vinylphenylsulfonate corresponding to the compound (B) is 53 mM, and the compound (C) is The corresponding 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride was dissolved at a concentration of 27 mM and the photopolymerization initiator 2,2-dimethoxy-2-phenylacetophenone was dissolved at a concentration of 8.5 mM, and a film-forming solution was prepared. Prepared.

The microporous support membrane was brought into contact with this solution, and nitrogen was blown from an air nozzle to remove excess solution from the surface of the support membrane to form a layer of the solution on the microporous support membrane. Next, using a UV irradiation apparatus capable of irradiating 365 nm ultraviolet light, setting the irradiation intensity to 40 mW / cm ² when using an ultraviolet integrated light meter, irradiating with ultraviolet light, and supporting the separation functional layer with a microporous structure A composite semipermeable membrane formed on the membrane surface was prepared.

Next, the obtained composite semipermeable membrane is kept in a hot air dryer at 150 ° C. for 2 hours to condense the silicon compound in which the hydrolyzable group is directly bonded to the silicon atom, and the separation function is provided on the microporous support membrane. A dry composite semipermeable membrane having a layer was obtained. Thereafter, the dried composite semipermeable membrane was immersed in an aqueous isopropyl alcohol solution for hydrophilization. The composite semipermeable membrane thus obtained was supplied with a 1500 ppm glucose aqueous solution adjusted to pH 6.5 or a 1500 ppm MgSO ₄ aqueous solution adjusted to pH 6.5 under the conditions of 0.75 MPa and 25 ° C. A filtration operation was performed. Table 1 shows the glucose solute removal rate of the membrane calculated from the formula (I) by measuring the quality of the permeated water and the feed water 3 hours after the start of operation. The MgSO ₄ removal rate was 89.0%.

(Example 2)
In the membrane forming solution of Example 1, the concentration of sodium 4-vinylphenylsulfonate of compound (B) was 40 mM, and the concentration of 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride of compound (C) A composite semipermeable membrane was produced in the same manner as in Example 1 except that the amount was 40 mM. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained. The removal rate of MgSO ₄ was 87.5%.

(Example 3)
In the membrane forming solution of Example 1, the concentration of sodium 4-vinylphenylsulfonate of compound (B) was 27 mM, and the concentration of 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride of compound (C). A composite semipermeable membrane was produced in the same manner as in Example 1 except that the value was 53 mM. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained. The MgSO ₄ removal rate was 68.9%.

Example 4
In the membrane-forming solution of Example 1, the concentration of sodium 4-vinylphenylsulfonate of compound (B) was 80 mM, and the concentration of 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride 40 mM of compound (C) was 2 A composite semipermeable membrane was prepared in the same manner as in Example 1 except that -hydroxyethyltrimethylammonium chloride 40 mM was used. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained. The MgSO ₄ removal rate was 86.3%.

(Example 5)
A composite semipermeable membrane was produced in the same manner as in Example 1 except that 80 mM of 4-vinylphenylsulfonate of compound (B) was changed to 53 mM of sodium methacrylate in the membrane-forming solution of Example 1. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained. The removal rate of MgSO ₄ was 75.7%.

(Comparative Example 1)
In the membrane-forming solution of Example 1, the concentration of sodium 4-vinylphenylsulfonate of compound (B) was 80 mM, and 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride of compound (C) was added. A composite semipermeable membrane was produced in the same manner as in Example 1 except that it was not added. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained.

(Comparative Example 2)
In the film forming solution of Example 1, sodium 4-vinylphenylsulfonate of compound (B) was not added, but 2- (acryloyloxy) -N, N, N-trimethylethaneammonium chloride of compound (C) was 80 mM. A composite semipermeable membrane was produced in the same manner as in Example 1 except that. The obtained composite semipermeable membrane was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained.
In Table 1, when comparing the glucose removal rate, the composite semipermeable membranes shown in Examples 1 to 5 have a larger glucose removal rate than the composite semipermeable membranes obtained in Comparative Examples 1 and 2. It can be seen that the neutral molecule removal rate is improved by the coexistence of the acidic group and the basic group. In Examples 1-5, as a result of the measurement of the aggregate structure by the small angle X-ray scattering method (SAXS), it was confirmed that the aggregate structure was smaller than those of Comparative Examples 1 and 2. Confirmation of the agglomerated structure size by SAXS is a technique adopted in the following cited reference 1 and the like.

As mentioned above, it turns out that it is effective for the improvement of a solute removal rate by making a compound (B) and a compound (C) coexist.
Reference 1: M.M. Fujimura, et al. , Macromoleculesx 14 (1981) 1309-1315.

The composite semipermeable membrane of the present invention includes solid-liquid separation, liquid separation, filtration, purification, concentration, sludge treatment, seawater desalination, drinking water production, pure water production, waste water reuse, waste water volume reduction, valuable material recovery, etc. In addition to being used in the field of water treatment, it can be used in the field of osmotic pressure power generation.

Claims (5)

A microporous support membrane, and a separation functional layer formed on the microporous support membrane,
The separation function layer contains a polymer formed by condensation of a hydrolyzable group of the compound (A) and polymerization of the compound (A) and the compounds (B) and (C ), and further the separation function The layer contains the compound (B) and the compound (C) that are not polymerized,
The compound semipermeable membrane in which the following compounds (B) and (C 1 ) each have one or more ethylenically unsaturated groups.
(A) one or more silicon compounds (B) having a silicon atom, a reactive group having an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom A compound (C) other than the compound (A) having an acidic group and a quaternary ammonium salt other than the compound (A) and the compound (B) having one or more basic groups Hydrolyzable group is an alkoxy group of the compound (A), an alkenyloxy group, a carboxy group, a ketoxime group, a composite half of claim 1 wherein at least one functional group selected from the group consisting of a halogen atom and isocyanate group Permeable membrane. The composite semipermeable membrane according to claim 1 or 2, wherein the compound (A) is represented by the following general formula (a).
Si (R1) _m (R2) _n (R3) _4-mn (a)
(R1 represents a reactive group containing an ethylenically unsaturated group. R2 represents at least one group selected from the group consisting of an alkoxy group, an alkenyloxy group, a carboxy group, a ketoxime group, an isocyanate group and a halogen atom. R3 represents at least one of hydrogen and an alkyl group, m and n are integers, and satisfy m + n ≦ 4, m ≧ 1, and n ≧ 1, and when m is 2 or more, R1 is the same as each other And when n is 2 or more, R2 may be the same or different from each other. When (4-mn) is 2 or more, R3 is the same as each other. Or different.) Wherein the acidic group is a carboxyl group of compound (B), at least one functional group selected from among a sulfonic acid group and a phosphonic acid group, a composite semipermeable membrane according to claim 1-3. A method for producing a composite semipermeable membrane comprising a microporous support membrane and a separation functional layer,
(A) preparing the microporous support membrane;
(B) forming the separation functional layer on the microporous support membrane;
With
The step (b)
(B1) applying a mixture of the following compound (A) and the following compound (B) and the following compound (C) on the microporous support membrane;
(B2) a step of condensing the hydrolyzable group possessed by the compound (A);
(B3) polymerizing the compound (A) with the compounds (B) and (C 1 ) ;
Including
The manufacturing method of the composite semipermeable membrane in which the following compounds (B) and (C 1 ) each have one or more ethylenically unsaturated groups.
(A) one or more silicon compounds (B) having a silicon atom, a reactive group having an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom A quaternary ammonium salt other than the compound (A) and the compound (B), which has one or more basic groups (C) other than the compound (A) having an acidic group