WO2023195479A1

WO2023195479A1 - Filtration membrane and production method for said membrane

Info

Publication number: WO2023195479A1
Application number: PCT/JP2023/014039
Authority: WO
Inventors: 秀人松山; ラジャブザデサイード; 崇佐々木; 将智高橋
Original assignee: 国立大学法人神戸大学; 日油株式会社
Priority date: 2022-04-08
Filing date: 2023-04-05
Publication date: 2023-10-12

Abstract

The present invention provides: a filtration membrane (particularly, a hollow fiber membrane-type filtration membrane) which effectively inhibits fouling, which has excellent recovery of water permeability after cleaning when fouling has occurred, and which has water resistance; and method for producing said membrane.　The present disclosure was achieved upon finding a method for producing a filtration membrane (particularly, a hollow fiber membrane-type filtration membrane) wherein: a filtration membrane is produced with a membrane-forming stock solution that contains a polymer which contains vinylidene fluoride as a monomer and an outside control solution that contains a polymer which contains styrene and maleic anhydride as monomers; and immobilizing on the filtration membrane a polymer that contains a specific phosphorylcholine group.

Description

Filtration membrane and method for manufacturing the membrane

The present disclosure relates to a filtration membrane (particularly a hollow fiber membrane filtration membrane) having both fouling resistance and water resistance, and a method for manufacturing the membrane.
This application claims priority to Japanese Application No. 2022-64806, which is incorporated herein by reference.

Recently, hollow fiber membrane filtration membranes such as ultrafiltration, microfiltration, and reverse osmosis have been used in many industrial fields such as drinking water production, water supply and sewage treatment, and wastewater treatment. Furthermore, hollow fiber membrane filtration membranes are increasingly being used in biopharmaceutical fields such as artificial dialysis, blood products, and antibody drugs.
Ultrafiltration membranes and microfiltration membranes, which are hollow fiber membrane filtration membranes, are widely used for water purification. However, the problem with hollow fiber membrane filtration membranes is that they are highly hydrophobic and easily foul. Fouling refers to causative substances called foulants contained in raw water (e.g., poorly soluble components, proteins, polymeric solutes such as polysaccharides, colloids, minute solids, microorganisms, etc.) that deposit on membranes and reduce the permeation flow rate. This phenomenon is known as the main cause of membrane performance deterioration.
As a manufacturing method for hollow fiber membrane filtration membranes that are highly effective against fouling caused by proteins and microorganisms, for example, materials that can suppress foulants such as proteins and microorganisms are retained or adsorbed on hollow fiber membrane filtration membranes. A method has been proposed.

(prior art)
Patent Document 1 discloses "a method for suppressing foulant adsorption by coating the surface of a hollow fiber membrane filtration membrane with a solution of a polymer obtained by polymerizing 2-methacryloyloxyethylphosphorylcholine."
Patent Document 2 discloses "a method in which a solution of a polymer obtained by polymerizing 2-methacryloyloxyethylphosphorylcholine is placed in a coagulation bath, and the polymer is incorporated into a film during film formation."
Patent Document 3 discloses "a production method for forming a film by mixing a solution of a polymer obtained by polymerizing specific 2-methacryloyloxyethylphosphorylcholine with polysulfone."

JP2012-055870A JP2016-077922A Retable No. 02/009857

The present disclosure provides a filtration membrane (particularly a hollow fiber membrane filtration membrane) that effectively suppresses fouling, is excellent in recovering water permeability after cleaning when fouling occurs, and has water resistance. An object of the present invention is to provide a method for manufacturing the membrane.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have developed a film-forming stock solution containing a polymer containing vinylidene fluoride as a monomer, and a film-forming solution containing a polymer containing styrene and maleic anhydride as monomers. A method for producing a filtration membrane (in particular, a hollow fiber membrane filtration membrane) in which a filtration membrane is produced using an external control liquid containing a polymer containing a specific phosphorylcholine group, and a polymer containing a specific phosphorylcholine group is immobilized on the filtration membrane. This discovery led to the completion of the present disclosure.
That is, the present disclosure is as follows.

1. Contains vinylidene fluoride as a monomer, immobilized with a polymer containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride as a monomer A filtration membrane comprising a polymer and a polymer containing styrene and maleic anhydride as monomers.
2. The filtration membrane according to the above item 1, wherein the filtration membrane is a hollow fiber membrane filtration membrane.
3. The polymer containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride as a monomer is 2-(methacryloyloxy)ethyl 2-(trimethylammonio). 2.) The filtration membrane according to item 1 above, which contains 40 mol% to 60 mol% of ethyl phosphate and 40 mol% to 60 mol% of 2-aminoethyl methacrylate or its hydrochloride.
4. The filtration membrane according to any one of items 1 to 3 above, which is for medical use.
5. The filtration membrane according to any one of items 1 to 3 above, which is for suppressing protein or bacterial adhesion.
6. A membrane forming stock solution preparation step (a) of preparing a membrane forming stock solution containing a polymer containing vinylidene fluoride as a monomer;
an external control liquid preparation step (b) of preparing an external control liquid containing a polymer containing styrene and maleic anhydride as monomers;
a process (c) for producing a film-forming stock solution in which the film-forming stock solution and the external control liquid are discharged in a film-form;
A membrane forming step (d) of manufacturing a filtration membrane by bringing the membrane-like membrane forming stock solution into contact with a coagulation liquid, and
an immobilization step (e) of reacting the filtration membrane with the polymer (P) to immobilize the polymer (P) on the membrane surface;
Here, the polymer (P) includes 30 mol% to 90 mol% of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 70 mol% to 10 mol% of 2-aminoethyl methacrylate or its hydrochloride. %,
Method for manufacturing a filtration membrane.

A monovinylidene fluoride on which a polymer (P) containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride of the present disclosure is immobilized is used. According to the method for producing a filtration membrane (particularly a hollow fiber membrane filtration membrane) containing a polymer containing styrene and maleic anhydride as monomers, the polymer (P) is It is immobilized so that it cannot be easily detached from the
That is, in the filtration membrane of the present disclosure (particularly the hollow fiber membrane filtration membrane), the polymer (P) does not elute in water, and the fouling suppressing effect can be maintained for a long period of time.

The present disclosure will be described in detail below.
(Filtration membrane of the present disclosure)
The filtration membrane of the present disclosure is made of vinylidene fluoride on which a polymer containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride is immobilized as a monomer. This is a filtration membrane (hereinafter sometimes simply referred to as "the filtration membrane of the present disclosure") including a polymer containing as a monomer and a polymer containing styrene and maleic anhydride as monomers.
The filtration membrane of the present disclosure includes a hollow fiber membrane filtration membrane and a flat membrane filtration membrane, and preferably a hollow fiber membrane filtration membrane.
An example of the composition of the hollow fiber membrane filtration membrane of the present disclosure is that a "polymer containing vinylidene fluoride as a monomer" and "a polymer containing maleic anhydride as a monomer" form a hollow fiber membrane by physical adsorption. formed and substantially free of core liquid.
In addition, a monomer (constituent unit) means a unit of a compound contained in a polymer based on each monomer or derived from each monomer.
Further, in this specification, when preferable numerical ranges (for example, content and discharge ratio) are described in stages, each lower limit value and upper limit value can be independently combined. For example, in the statement "preferably 10 to 100, more preferably 20 to 90", "preferable lower limit: 10" and "more preferable upper limit: 90" can be combined to become "10 to 90". .

(Method for manufacturing hollow fiber membrane filtration membrane of the present disclosure)
A method for manufacturing a hollow fiber membrane filtration membrane of the present disclosure includes the following steps.
Film forming stock solution preparation step (a) of preparing a film forming stock solution containing a polymer containing vinylidene fluoride as a monomer
External control liquid preparation step (b) of preparing an external control liquid containing a polymer containing styrene and maleic anhydride as monomers.
Membrane-form membrane-forming stock solution production process (c) in which hollow fibers are manufactured by discharging at least a membrane-forming stock solution and an external control liquid into a hollow fiber membrane shape.
Membrane forming step (d) of manufacturing a hollow fiber membrane filtration membrane by bringing the hollow fibers into contact with a coagulation liquid
Immobilization step (e) of reacting the hollow fiber membrane filtration membrane and the polymer (P) to immobilize the polymer (P) on the membrane surface.
Here, the polymer (P) includes 30 mol% to 90 mol% of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 70 mol% to 10 mol% of 2-aminoethyl methacrylate or its hydrochloride. It is preferable that
More specifically, the method for producing a hollow fiber membrane filtration membrane of the present disclosure includes a membrane forming stock solution in which a polymer containing vinylidene fluoride as a monomer is dissolved, a polymer containing styrene and maleic anhydride as monomers, A hollow fiber is manufactured by discharging an external control liquid and a core liquid containing A hollow fiber membrane filtration membrane that has both fouling resistance and water resistance can be produced by reacting a thread membrane filtration membrane with a polymer (P) to immobilize and coat the polymer (P) on the membrane surface. The points are distinctive.
Here, the term "fouling resistance" means that the amount of water permeation is less likely to decrease during filtration using the hollow fiber membrane filtration membrane of the present disclosure, and that the decreased amount of water permeation is recovered during washing.
Moreover, water resistance means that the polymer (P) does not peel off from the hollow fiber membrane filtration membrane of the present disclosure.

(Membrane forming stock solution)
As the polymer containing vinylidene fluoride as a monomer contained in the membrane forming stock solution of the present disclosure, vinylidene fluoride alone or copolymerized with other monomers can be used. Polymers containing only vinylidene fluoride are commercially available, for example, available from Solvay Specialty Polymers Japan Co., Ltd. (Solef ^{(registered trademark)} 11010, Solef ^{(registered trademark)} 31508, Solef ^{(registered trademark)} 6020, etc.) ).
Other monomers copolymerized with vinylidene fluoride include, but are not particularly limited to, propylene hexafluoride, tetrafluoroethylene, ethylene, ethylene tetrafluoride, ethylene trifluorochloride, vinyl fluoride, and the like.
In addition, hollow fibers can be produced in the membrane forming stock solution if the polymer containing vinylidene fluoride as a monomer is in the range of 10% to 40% by weight, but in order to produce good hollow fibers, 15% by weight is required. % to 30% by weight is preferred, and 20% to 30% by weight is more preferred.
The polymer containing vinylidene fluoride as a monomer (constituent unit) contained in the membrane forming stock solution of the present disclosure is preferably exemplified by polyvinylidene fluoride.
As the solvent for the membrane forming stock solution of the present disclosure, glycerol triacetate, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and the like can be used. Glycerol triacetate is preferred from the viewpoint of phase separation when the membrane forming stock solution, external control solution, and core solution are immersed (discharged) into the coagulation solution.

(External control liquid)
The polymer containing styrene and maleic anhydride as monomers (constituent units) contained in the external control liquid of the present disclosure is a polymer containing styrene and maleic anhydride as constituent units, or a polymer containing styrene and maleic anhydride as monomers (constituent units), or a polymer containing styrene and maleic anhydride as monomers (constituent units), or , or other monomers (ester, carboxylic acid, diammonium maleate, monoammonium maleate monoester, monoester maleate) can be used as a constituent unit.
Polymers of styrene and maleic anhydride are available from Polyscope Polymers. For example, XIRAN ^{(registered trademark)} 1000P, XIRAN ^{(registered trademark)} 2000P, XIRAN ^{(registered trademark)} 3000P, XIRAN ^{(registered trademark)} EF30, and XIRAN ^{(registered trademark)} EF40.
Polymers based on styrene and maleic anhydride, as well as other monomers, are available from Polyscope Polymers. For example, XIRAN ^{(registered trademark)} 1440 and XIRAN ^{(registered trademark)} 2625P can be exemplified.
In addition, the content of the polymer containing styrene and maleic anhydride as monomers in the external control liquid can be set at 1% by weight to 40% by weight, but in order to produce good hollow fibers, 1% by weight is required. % to 20% by weight is preferred, and 1% to 5% by weight is more preferred.
The polymer containing styrene and maleic anhydride as monomers (constituent units) contained in the external control liquid of the present disclosure is preferably exemplified by a polymer containing styrene and maleic anhydride as monomers. .
As the solvent for the external control liquid of the present disclosure, glycerol triacetate, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and the like can be used. Glycerol triacetate is preferred from the viewpoint of phase separation when the membrane forming stock solution, external control solution, and core solution are immersed (discharged) into the coagulation solution.

(core liquid)
As the core liquid of the present disclosure, glycerol triacetate, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and the like can be used.
Glycerol triacetate is preferred from the viewpoint of phase separation when the membrane forming stock solution, external control solution, and core solution are immersed (discharged) into the coagulation solution.

(Discharge ratio of film forming stock solution, external control liquid and core liquid)
The discharge ratio of the membrane forming stock solution, external control liquid, and core liquid is 1 part to 40 parts by mass of the film forming stock solution, 0.1 part to 20 parts by mass of the external control liquid, and 0.1 part by mass to the core liquid. The amount may be 50 parts by mass, but in order to produce good hollow fibers, preferably 0.1 to 10 parts by mass of the external control liquid and 0 parts by mass of the core liquid to 1 to 20 parts by mass of the membrane forming stock solution. .1 parts by mass to 20 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass of the external control liquid and 0.1 parts by mass to 10 parts by mass of the core liquid per 1 part by mass to 5 parts by mass of the membrane forming stock solution. be.
Furthermore, the discharge speed of the membrane forming stock solution, external control liquid, and core liquid is preferably 5 to 20 g/min, more preferably 7 to 9 g/min, and preferably 1 to 10 g/min for the external control liquid. /min, more preferably 2 to 4 g/min, and the core liquid is preferably 3 to 20 g/min, more preferably 5 to 8 g/min. When the discharge speed is within this range, good hollow fibers can be manufactured and the fouling suppressing effect is excellent.

(coagulation liquid)
Examples of the coagulating liquid of the present disclosure include water, which is a solvent that does not dissolve the hollow fiber membrane filtration membrane of the present disclosure. The amount of coagulation liquid used can be 100 parts by mass to 100,000,000 parts by mass per 100 parts by mass of the membrane-forming stock solution, but in order to favorably proceed with the formation of the hollow fiber membrane filtration membrane. It is preferable to use 1,000 parts by mass to 100,000,000 parts by mass of the coagulating liquid, and more preferably to use 1,000 parts by mass to 100,000 parts by mass.

(Method for producing hollow fiber membrane filtration membrane by thermally induced phase separation method of the present disclosure)
The method of manufacturing a hollow fiber membrane filtration membrane by the thermally induced phase separation method of the present disclosure includes discharging a membrane forming stock solution, a membrane forming stock solution, an external control liquid, and a core liquid from a concentric multi-slit nozzle, and cooling them with a low-temperature coagulation liquid. This causes phase separation into a concentrated phase and a dilute phase in each of the polyvinylidene fluoride layer and the styrene maleic anhydride polymer layer. In this dense phase, a hollow fiber membrane is formed in which the surface of polyvinylidene fluoride is covered with a styrene maleic anhydride polymer.

The specific manufacturing process will be explained.
Film forming stock solution preparation step (a): 10% to 40% by weight of polyvinylidene fluoride is added to glycerol triacetate and dissolved by heating to 50 to 200° C. to obtain a film forming stock solution.
External control liquid preparation step (b): Add 1% to 40% by weight of styrene maleic anhydride polymer to glycerol triacetate, and dissolve by heating to 50 to 200°C to obtain an external control liquid.
Membrane-form membrane forming stock solution manufacturing process (hollow fiber manufacturing process) (c): The membrane forming stock solution, external control liquid, and core liquid (glycerol triacetate) are discharged from a triple slit nozzle to obtain hollow fibers.
Membrane forming step (d): The hollow fibers are brought into contact with (immersed in) a coagulating liquid (water) and cooled to obtain a hollow fiber membrane filtration membrane. The temperature of the coagulating liquid is preferably 5°C to 40°C.
Immobilization step (e): The hollow fiber membrane filtration membrane and polymer (P) are immersed in water in which 0.1% to 1% by weight of triethylamine is dissolved, and reacted at 5°C to 95°C for 1 to 10 hours. The polymer (P) is immobilized on the membrane surface to obtain a hollow fiber membrane filtration membrane of the present disclosure.
In addition, after the membrane forming step (d) and/or the immobilization step (e), a washing step of removing the solvent etc. using water or hot water at 5° C. to 95° C., an extraction step of removing the solvent by extraction, A drying step at 5 to 70° C. may also be performed.
Furthermore, when the hollow fiber membrane filtration membrane is not used immediately, it can be stored in a storage solution containing water, glycerin, or ethanol.

(Polymer (P))
The polymer (P) of the present disclosure comprises 30 mol% to 90 mol% of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 70 mol% to 10 mol% of 2-aminoethyl methacrylate or its hydrochloride. Although a polymer obtained by polymerizing 2-(methacryloyloxy)ethyl 2-( Preferably, the amount is 40 mol% to 60 mol% of trimethylammonio)ethyl phosphate and 60 mol% to 40 mol% of 2-aminoethyl methacrylate or its hydrochloride.
The polymer (P) of the present disclosure may have any structure such as a random polymer or a block polymer, or may be a mixture of these polymers.

(Method for producing polymer (P))
As a method for producing the polymer (P), known methods such as solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization can be used. For example, 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl A method can be adopted in which a phosphate and 2-aminoethyl methacrylate or its hydrochloride are subjected to a polymerization reaction in a solvent in the presence of a polymerization initiator.
The solvent used in the polymerization reaction may be any solvent that dissolves 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride; specifically, water, methanol, ethanol, etc. , propanol, t-butanol, benzene, toluene, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, chloroform, etc., and two or more types may be mixed.
As the initiator used in the polymerization reaction, any common initiator may be used. For example, in the case of radical polymerization, an azo compound (water-soluble azo polymerization initiator) or an organic peroxide can be used. .

(Imobilization step (e))
The solvent used when performing the immobilization reaction between the hollow fiber membrane filtration membrane and the polymer (P) in the immobilization step (e) of the present disclosure is a solvent in which the polymer (P) is dissolved and which is a membrane material. Any solvent that does not dissolve the polyvinylidene fluoride or styrene maleic anhydride polymer can be used. Examples include water, methanol, ethanol, propanol, t-butanol, benzene, toluene, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, chloroform, etc., and two or more types may be mixed.

The concentration of the polymer (P) when performing the immobilization reaction between the hollow fiber membrane filtration membrane and the polymer (P) may be between 0.1% and 10% by weight, but this may be due to economical and environmental considerations. Considering the influence, 0.1% by weight to 5% by weight is preferable.

When carrying out the immobilization reaction between the hollow fiber membrane filtration membrane and the polymer (P), a catalyst can be used to promote the reaction. As a catalyst, an acid catalyst or a base catalyst can be used as the solvent used in the immobilization reaction of the hollow fiber membrane filtration membrane and the polymer (P). Examples include hydrochloric acid, acetic acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid monohydrate, etc. Base catalysts include 4-dimethylaminopyridine, pyridine, triethylamine, etc., but triethylamine is preferred from the viewpoint of reactivity and cost. is preferred.

The amount of catalyst used when performing the immobilization reaction between the hollow fiber membrane filtration membrane and the polymer (P) can be in the range of 0.1% to 10% by weight, but it is important to maintain reactivity and protect the environment. Considering the influence, it is preferably 0.1% to 5% by weight, more preferably 0.1% to 1% by weight.

(Applications of the filtration membrane of the present disclosure)
The filtration membrane of the present disclosure (in particular, the hollow fiber membrane filtration membrane) has been confirmed to have excellent fouling resistance and water resistance through the following examples. All applications where filtration membranes, reverse osmosis membranes, etc. are used (e.g., removal of microorganisms, bacteria, and viruses, separation and concentration of proteins, enzymes, etc., artificial dialysis, separation and removal of yeast in the production of draft sake and draft beer, seawater desalination) It can be used for production of industrial pure water and ultrapure water, concentration of fruit juice and milk, purification of wastewater, etc.).

Specific configurations of the filtration membrane of the present disclosure can be exemplified below, but are not particularly limited.
(1) Consisting of vinylidene fluoride as a monomer, immobilized with a polymer composed of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate hydrochloride as monomers. A filtration membrane containing a polymer composed of a polymer (polyvinylidene fluoride), styrene, and maleic anhydride as monomers.

Hereinafter, the present disclosure will be specifically explained using Examples, but the present disclosure is not limited to the Examples.

(Synthesis of polymer (P))
〇Synthesis example 1: Polymer (P-1)
54.59 g of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate (NOF Corporation) and 30.62 g of 2-aminoethyl methacrylate hydrochloride (Sigma-Aldrich) were dissolved in 165.41 g of water. , nitrogen was bubbled for 30 minutes. Subsequently, 1.66 g of V-50 (Fuji Film Wako Pure Chemical Industries, Ltd.) dissolved in 98.34 g of water was added as a polymerization initiator, and polymerization was carried out at 72° C. for 2 hours. After the polymerization was completed, 467 g of water was added to adjust the polymer concentration to 10% by weight.
Molar ratio of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate hydrochloride 50:50
Weight average molecular weight: 200,000 The weight average molecular weight of the polymer (P-1) was measured under the following conditions.
GPC device: Tosoh Corporation HLC-8420GPC
Column used: Ultra-Hydrogel Liner 300 x 7.8 mm manufactured by Waters Co., Ltd.
Mobile phase: 0.2mol/L sodium nitrate (contains 0.02wt% sodium azide)
Detector: Differential refractive index detector Flow rate: 0.5mL/min
Sample injection volume: 100μL
Standard substance: Pullulan Redical Kit (pulkitr1h manufactured by PSS)
〇Synthesis example 2: Polymer (P-2)
It was prepared in the same manner as in Synthesis Example 1, except that 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate was used in an amount of 76.43 g, and 2-aminoethyl methacrylate hydrochloride was added in an amount of 18.37 g.
Molar ratio of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate hydrochloride 70:30
Weight average molecular weight: 280,000 The weight average molecular weight of the polymer (P-2) was measured in the same manner as that of the polymer (P-1).
〇Synthesis example 3: Polymer (P-3)
It was prepared by performing the same operation as in Synthesis Example 1 except that 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate was used as 98.26 g and 2-aminoethyl methacrylate hydrochloride was used as 6.12 g.
Molar ratio of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate hydrochloride 90:10
Weight average molecular weight: 290,000 The weight average molecular weight of the polymer (P-3) was measured in the same manner as that of the polymer (P-1).

(Manufacturing example 1)
(Production of hollow fiber membrane filtration membrane by thermally induced phase separation method)
Film forming stock solution preparation step (a): 25 parts by mass of polyvinylidene fluoride powder (Solvay 6020 manufactured by Solvay Specialty Polymers Japan Co., Ltd., weight average molecular weight 687 kDa) was added to glycerol triacetate (Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter referred to as " 75 parts by mass (sometimes abbreviated as "GTA") was stirred and dissolved at 130° C. for 6 hours.
External control liquid preparation step (b): 10 parts by mass of styrene maleic anhydride polymer (SMA-6000 manufactured by Polyscope Polymers, weight average molecular weight 10 kDa, polystyrene:maleic anhydride molar ratio 6:1) to 190 parts by mass of GTA. It was dissolved at 60°C.
Hollow fiber manufacturing process (c): The membrane forming stock solution, external control liquid, and core solution (GTA) were discharged at 190°C from a twin-screw extruder equipped with a triple orifice spinning die (ULTnano series TW05, manufactured by Technovel). .
The discharge speed was 8.5 g/min for the film forming stock solution, 2.5 g/min (2 ml/min) for the external control liquid, and 6.2 g/min for the core solution (GTA).
Membrane forming step (d): The discharged hollow fibers were immersed in a coagulating liquid (water) and cooled to obtain a hollow fiber membrane-like filtration membrane. At this time, the temperature of the coagulation liquid was 15°C.
Washing step (d-1): Once the hollow fiber membrane filtration membrane was formed, it was soaked in 40°C warm water to remove glycerol triacetate.
Storage step (d-2): The hollow fiber membrane filtration membrane was left standing in pure water and stored.

(Production of hollow fiber membrane filtration membrane (M-1) with immobilized polymer (P-1) of the present disclosure)
The hollow fiber membrane filtration membrane (30 cm) produced in Production Example 1 was immersed in water containing 2 wt% polymer (P-1) and 0.25 wt% triethylamine (catalyst: Fuji Film Wako Pure Chemical Industries, Ltd.). After that, the solution temperature was raised to 60°C and left for 6 hours. Thereafter, it was washed with pure water and stored in pure water.

(Production of hollow fiber membrane filtration membrane (M-2) with immobilized polymer (P-2) of the present disclosure)
A hollow fiber membrane filtration membrane of the present disclosure was produced in the same manner as in Example 1, except that polymer (P-1) was replaced with polymer (P-2).

(Production of hollow fiber membrane filtration membrane (M-3) with immobilized polymer (P-3) of the present disclosure)
A hollow fiber membrane filtration membrane of the present disclosure was produced in the same manner as in Example 1, except that polymer (P-1) was replaced with polymer (P-3).

Regarding the hollow fiber membrane filtration membrane (M-1) of the present disclosure manufactured in Example 1, first, the water permeation amount (LMH/Bar) was measured at 1 bar using pure water (initial water permeation amount).
Subsequently, a 1,000 ppm bovine serum albumin solution was used as a model foulant, and the solution was permeated for 60 minutes. Thereafter, backwashing was performed for 10 minutes using pure water with the direction of water permeation reversed. After backwashing, the amount of water permeation (LMH/Bar) was measured again using pure water (the amount of water permeation after the first backwashing), and the water permeation recovery rate (%) was calculated.
After that, in the same way, the bovine serum albumin solution was permeated for 60 minutes, backwashed for 10 minutes using pure water, and the amount of water permeated was measured using pure water (water permeation amount after second backwashing). Recovery rate (%) was calculated. This operation was repeated until a total of 7 times. The results are shown in Table 1.
Note that the water permeability recovery rate (%) is a value expressed by the following formula (1). The unit of water permeation rate "LMH/Bar" represents the amount (L) of pure water passing through the filter membrane per 1 ^m2 of the filter membrane per hour under 1 bar.
Water permeability recovery rate (%) = (Water permeation amount after backwashing/Initial water permeation amount) x 100...Formula (1)
In Comparative Example 1, the hollow fiber membrane filtration membrane manufactured in Manufacturing Example 1 was used.

Regarding the hollow fiber membrane filtration membrane (M-1) of the present disclosure produced in Example 1, first, a 0.85% by weight sodium chloride (Fujifilm Wako Pure Chemical Industries, Ltd.) aqueous solution was used at 0.5 bar. The water permeation amount (LMH/Bar) was measured (initial water permeation amount).
Subsequently, a bacterial suspension (Sphingomonas paucimobilis) was used as a model foulant, and the solution was permeated for 90 minutes. Thereafter, backwashing was performed for 10 minutes with a 0.85% by weight aqueous sodium chloride solution in which the direction of water permeation was reversed. After backwashing, the amount of water permeation (LMH/Bar) was measured again using a 0.85% by weight aqueous sodium chloride solution (the amount of water permeation after the first backwashing), and the water permeation recovery rate (%) was calculated.
Thereafter, the cell suspension was permeated for 90 minutes in the same manner, backwashed for 10 minutes using a 0.85% by weight aqueous sodium chloride solution, and the amount of water permeated was determined using a 0.85% by weight aqueous sodium chloride solution. It was measured (water permeation amount after second backwashing) and water permeation recovery rate (%) was calculated.
The water permeability recovery rate (%) is a value expressed by the following formula (2). The unit of water permeation amount "LMH/Bar" represents the amount of water passing through the filter membrane (L) per 1 m ² of the filter membrane per hour under 1 bar. The results are shown in Table 2.
Water permeability recovery rate (%) = (water permeability after backwashing/initial water permeation) x 100...Formula (2)
The bacterial suspension was prepared by culturing the culture using tryptic soy broth (manufactured by Becton Dickinson, 30 g/L) at 120 rpm and 30°C for 12 hours with shaking, then diluting it 50 times with tryptic soy broth and culturing it for 4 hours. The cells were cultured again at ℃ and diluted with tryptic soy broth to a bacterial concentration of 0.05 at 450 nm absorbance.
In Comparative Example 2, the hollow fiber membrane filtration membrane manufactured in Manufacturing Example 1 was used.

The hollow fiber membrane filtration membrane (M-1) of the present disclosure manufactured in Example 1 was cut into approximately 1 cm pieces, placed on a test stand, and a water droplet was dropped on it, and the contact angle change was determined with the moment of drop as the initial stage and 120 seconds later as the final stage. was measured.
Furthermore, the contact angle was similarly measured for the hollow fiber membrane filtration membrane (M-1) of the present disclosure that had been stored in water for 30 and 60 days. The results are shown in Table 3.
The contact angle was measured using a contact angle goniometer Drop Master (manufactured by Kyowa Interface Science Co., Ltd.).
In Comparative Example 3, the hollow fiber membrane filtration membrane manufactured in Manufacturing Example 1 was used.

The contact angle change was measured in the same manner as in Example 6, except that the hollow fiber membrane filtration membrane (M-2) of the present disclosure manufactured in Example 2 was used. The results are shown in Table 3.

The contact angle change was measured in the same manner as in Example 6, except that the hollow fiber membrane filtration membrane (M-3) of the present disclosure manufactured in Example 3 was used. The results are shown in Table 3.

(Evaluation of the hollow fiber membrane filtration membrane of the present disclosure)
As is clear from Tables 1 and 2, the water permeation recovery rate of the hollow fiber membrane filtration membrane of the present disclosure was significantly superior to that of Comparative Example 1. In particular, the hollow fiber membrane filtration membrane of the present disclosure showed a high water permeability recovery rate even when the number of backwashes was increased, and also showed a high water permeability recovery rate even in cell suspensions containing proteins and bacteria. Highly ring-like.
As is clear from Table 3, the hollow fiber membrane filtration membrane of the present disclosure did not change the contact angle even after being stored in water for a long period of time, so the polymer (P) did not peel off, and it was excellent. It was revealed that it has water resistance.
As described above, the hollow fiber membrane filtration membrane of the present disclosure has excellent fouling resistance and water resistance.

To provide a hollow fiber membrane filtration membrane with excellent fouling resistance and water resistance.

Claims

A polymer containing vinylidene fluoride as a monomer, on which a polymer containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride as a monomer is immobilized. and a filtration membrane containing a polymer containing styrene and maleic anhydride as monomers.
The filtration membrane according to claim 1, wherein the filtration membrane is a hollow fiber membrane filtration membrane.
The polymer containing 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 2-aminoethyl methacrylate or its hydrochloride as a monomer is 2-(methacryloyloxy)ethyl 2-(trimethylammonio). 2. The filtration membrane according to claim 1, wherein the filtration membrane contains 40 mol% to 60 mol% of ethyl phosphate and 40 mol% to 60 mol% of 2-aminoethyl methacrylate or its hydrochloride.
The filtration membrane according to any one of claims 1 to 3, which is for medical use.
The filtration membrane according to any one of claims 1 to 3, which is for suppressing protein or bacterial adhesion.
A membrane forming stock solution preparation step (a) of preparing a membrane forming stock solution containing a polymer containing vinylidene fluoride as a monomer;
an external control liquid preparation step (b) of preparing an external control liquid containing a polymer containing styrene and maleic anhydride as monomers;
a process (c) for producing a film-forming stock solution in which the film-forming stock solution and the external control liquid are discharged in a film-form;
A membrane forming step (d) of manufacturing a filtration membrane by bringing the membrane-like membrane forming stock solution into contact with a coagulation liquid, and
an immobilization step (e) of reacting the filtration membrane with the polymer (P) to immobilize the polymer (P) on the membrane surface;
Here, the polymer (P) includes 30 mol% to 90 mol% of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 70 mol% to 10 mol% of 2-aminoethyl methacrylate or its hydrochloride. %,
Method for manufacturing a filtration membrane.