JPH022862A - Modified separating membrane - Google Patents

Abstract

PURPOSE:To obtain a modified separating membrane having superior heat and chemical resistances and satisfactory permeability by using modified polysulfone resin contg. a hydrophobic polymer and hydrophilic polymers in a specified ratio. CONSTITUTION:Modified polysulfone resin contg. a hydrophilic-hydrophobic graft or block copolymer consisting of a hydrophobic polymer, preferably arom. polysulfone and a hydrophilic polymer in combination with other hydrophilic polymer is used as a membrane forming material. The total amt. of the hydrophilic polymers in the resin is regulated to <=80wt.% of the amt. of the resin and the amt. of the hydrophobic polymer to >=20wt.%. The microporous surface of a membrane made of the modified polysulfone resin is highly hydrophilic, but the polymer matrix has a phase separated structure, so the membrane ensures a high rate of water permeation, is hardly contaminated and has superior mechanical strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a modified separation membrane, more specifically a hydrophilic membrane comprising a hydrophobic aromatic polymer and a hydrophilic polymer.
The present invention relates to a modified separation membrane that is made of a polysulfone resin containing a hydrophobic graft copolymer or a block copolymer together with a second hydrophilic polymer, has excellent heat resistance, chemical resistance, etc., and has good permeability.

It is characterized by a structure containing the repeating unit shown in As expected from this structure, polysulfone resin has excellent durability and stability, but on the other hand, it exhibits hydrophobic properties. Typical products are commercially available under the trade names of Victrex from Inverial Chemical Industries (abbreviated as IC1) and Lldel from Union Carbide Co. (abbreviated as UCC), but the former has a water absorption rate of 0. 4%, the latter 0.3% (both ASTM D 5
70), which is less than 1 in 10 of cellulose acetate, which is known as a hydrophilic membrane material resin. Due to this hydrophobic property, conventional polysulfone membranes are difficult to wet with water when dried to a certain degree, have low water permeability, and
There were many problems, including the fact that hydrophobic solutes adhere to the membrane surface and cause contamination.

In order to solve these problems, various methods have been proposed to improve polysulfone membranes.

As a method for providing a hydrophilic polysulfone film by introducing a wood-loving group or a wood-loving polymer into an aromatic polysulfone polymer, for example, Japanese Patent Publication No. 13679/1982 and Japanese Patent Application Laid-open No. 1983-1989 are known.
No. 196322, etc., is a reverse osmosis membrane made from an aromatic polysulfone polymer made hydrophilic by introducing or grafting a sulfonic acid group into the polymer main chain, and JP-A-57-174104, which is made hydrophilic by introducing or grafting polyethyleneimine polymers into the polymer main chain. We are proposing a method to provide such. All of these methods are modification methods in which hydrophilic groups or hydrophilic polymers are randomly and uniformly bonded to the aromatic rings of the main chain of aromatic polysulfone polymers through covalent bonds, so they are made of unmodified polymers. It is inevitable that physical properties such as heat resistance will be lower than that of membranes. Furthermore, if the proportion of hydrophilic groups introduced into the polymer is high, the resulting membrane may swell with water, which can be said to be a modification method that involves significant changes in the physical properties of the membrane.

On the other hand, various hydrophilized polysulfone membranes made of mixed polymers in which a hydrophilic polymer is blended with an aromatic polysulfone polymer have also been proposed. For example, JP-A-57-5
No. 0507 discloses cellulose derivatives in Japanese Patent Application Laid-open No. 60-20
No. 6404 proposes a hydrophilized polysulfone membrane made of a mixed polymer obtained by blending ethylene-vinyl alcohol copolymers. However, in order to obtain a substantially hydrophilized polysulfone membrane, a significant amount of different polymers must be blended, and it is difficult to obtain a homogeneous blend with polymers with high molecular cohesion, such as aromatic polysulfone polymers. was difficult. In particular, when attempting to produce the above-mentioned hydrophilized polysulfone membrane by bringing a membrane-forming solution containing a polar organic solvent and a polymer into contact with a non-solvent for a polymer whose main component is water, and coagulating and molding the polymer, In addition to being difficult to obtain a uniform film-forming solution, there are problems with the stability of the solution, such as gelation and phase separation when left standing, and when the polymer coagulates due to contact with non-solvents, different polymers may form. There was also the possibility that the membrane structure would become non-uniform due to separation. In this way, the addition of different polymers was thought to cause deterioration of physical properties such as heat resistance and chemical resistance of the film, not only due to the effect of adding polymers with inferior physical properties, but also due to the formation of a non-uniform film structure. .

In response to the above proposal, as a method for making the membrane surface hydrophilic without impairing the physical properties of the polysulfone polymer, for example, JP-A-60-87803 proposes forming a polysulfone membrane and then applying chlorosulfonic acid while maintaining the membrane shape. JP-A-59-186604 describes a method for sulfonating polymers.
We have proposed methods for treating polysulfone films with positive column plasma. However, such a method targets only products or semi-finished products on which film formation has been completed, and is a complicated method requiring special methods and equipment, and is not a method for boat fishing.

[Means to solve the problem]

As a result of intensive research in view of the above, the present inventors have discovered that a hydrophilic-hydrophobic graft copolymer or a block copolymer consisting of a hydrophobic polymer, preferably an aromatic polysulfone, and a hydrophilic polymer can be used as a second hydrophilic polymer. The present inventors have discovered that a hydrophilic polysulfone membrane can be obtained by using a modified polysulfone resin contained together with a polysulfone polymer as a membrane material, and have completed the present invention. The purpose of the present invention is to develop a hydrophilic polysulfone membrane as a separation membrane with excellent physical properties and good permeability without impairing the excellent physical properties of polysulfone membranes such as heat resistance and chemical resistance. Our goal is to provide the following.

That is, the present invention provides hydrophobic aromatic polymer A and hydrophilic polymer B.
A resin containing a hydrophilic-hydrophobic graft copolymer or a block copolymer consisting of a hydrophilic polymer C and a polysulfone resin, wherein the hydrophilic polymer component in the resin is the total resin including B and C. 80% by weight or less of the components, and the hydrophobic polymer component is 20% by weight of the total resin component including A and D.
The present invention provides a modified separation membrane characterized by being made of the modified aromatic resin as described above.

As mentioned above, aromatic polysulfone is most preferable as the polysulfone resin, and more specifically, it is a homopolymer having a repeating unit of the following formula (I), or a homopolymer having a repeating unit of the formula (I) and a repeating unit of the following formula (II). A copolymer having at least one type of repeating unit selected from -(1'V) is preferable.

Moreover, as the hydrophobic aromatic polymer A, the same one as the above-mentioned polysulfone resin is preferable.

Further, particularly representative hydrophilic polymers B and C are vinyl-based hydrophilic polymers, and more specifically, each preferably has one or more of the following structures as a hydrophilic component. In this case, the hydrophilic polymer B is required to have a component that binds to the hydrophobic aromatic polymer A in addition to the hydrophilic component described below.

-CR, -CH2- [Here, R1 is hydrogen or a methyl group. Also, R3 is (R
3 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms. ).

C00M ( ), 1 is hydrogen or an alkali metal or basic substance that ionically bonds with a carboxylic acid ion. ).

CDOR.

(R4 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms).

C00NR5R6 (Rs, R6 are each hydrogen or an aliphatic hydrocarbon group having I to 20 carbon atoms).

(n is an integer from 0 (valence bond) to 10; M is hydrogen, or an alkali metal or basic substance that ionically bonds with the sulfonate ion).

/\Rs Re (R, , R, and R3 are each an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and 0 is a halogen ion).

(Rho is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, n is an integer of 4 to 6, and xo is a halogen ion).

(R11 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and xo is a halogen ion.) ] In addition to the above, preferred hydrophilic polymers include sulfonated polysulfone polymers.

Specifically, a homopolymer having the above-mentioned repeating unit of formula (I) is sulfonated by a known method, or a repeating unit of formula (I) and at least one member selected from formulas (II) to (IV) Preferably, a copolymer having repeating units is sulfonated by a known method.

Next, a graft copolymer and a block copolymer comprising hydrophobic aromatic polymer A and hydrophilic polymer B will be described.

Regarding the former graft copolymer, the present inventors have already reported in Japanese Patent Application Laid-Open No. 168503/1982 and Japanese Patent Application No. 224205/1983.
It can be synthesized using the method detailed in No. 1, etc.

That is, a hydrophilic polymer having a reactive functional group is reacted with a hydrophobic aromatic polymer having a functional group at the end that can react with the functional group, or an active group such as a vinyl group is reacted at the end. It can be obtained by copolymerizing a hydrophobic aromatic polymer with a hydrophilic monomer or oligomer.

Examples of combinations of specific reactive functional groups and terminal groups capable of reacting with the functional groups include the following from known organic chemical reactions.

(1) When the terminal group is a hydroxyl group or an alkali alcoholade group: A functional group such as an acid halide group, an acid anhydride group, a glycidyl group, a halomethyl group, or a sulfonyl halide group.

(2) When the terminal group is a halogenated alkyl group or a halogenated aryl group: +C112→, OM group (:, 1 is an alkali metal, m is 0
(valence bond) or positive integer), amino group (this is the first
．． (which may be secondary or tertiary).

(3) When the terminal group is an amino group: Functional groups such as halogenated alkyl groups and acid halide groups.

(4) If the terminal group is an epoxy group, Functional groups such as amino groups and alcoholade groups.

(5) When the terminal group is a carbonyl group, -Functional groups such as NHN32 groups and hydroxyl groups.

(6) When the terminal group is a carboxyl group: a functional group such as a hydroxyl group.

In addition, when introducing an active terminal group into a hydrophobic aromatic polymer or a functional group into a hydrophilic polymer, known organic chemical reactions may be used. It is necessary to carry out the reaction under conditions that do not reduce the degree of polymerization of the group polymer as much as possible. In the latter case, it is necessary to set appropriate reaction conditions so as not to change the functional groups of the hydrophilic component in an unfavorable direction or reduce the degree of polymerization.

Of course, commercially available monomers, oligomers, or aromatic polysulfone polymers that already have reactive functional groups or terminal groups may be used as they are.

The graft copolymer of the present invention or the polysulfone resin containing the same is produced by reacting the hydrophilic polymer as described above with a terminally reactive hydrophobic aromatic polymer, particularly preferably a polysulfone polymer.

In this case, care must be taken to set reaction conditions such that only one end group of the hydrophobic aromatic polymer can react.

If both terminal groups participate in the reaction, a crosslinking reaction will occur, resulting in a gel-like substance that is insoluble in the solvent.

Therefore, either a method is applied in which a reactive end group is introduced in advance onto only one side of the hydrophobic aromatic polymer, or only one of both end groups is activated.

On the other hand, the block copolymer can be synthesized using the method already described in detail by the present inventors in Japanese Patent Applications No. 196696/1982 and No. 92607/1982.

That is, when the hydrophilic polymer B is a sulfonated polysulfone polymer, the following method is available.

(1) A homopolymer consisting only of repeating units of formula (I) is prepared using conventional methods (for example, Japanese Patent Publication No. 47-617 or Japanese Patent Publication No. 42
-7799),
Without stopping the reaction, the monomers (n) to (rV) are subsequently copolymerized with the monomer (1) by a known method (for example, Canadian Patent No. 847,963) using the active end as a polymerization initiation point. Next, the repeating units (■) to (rV) are selectively sulfonated by a known method (for example, using concentrated sulfuric acid or chlorosulfonic acid).

(2) The end group (-CA or -OH) of a commercially available polyether sulfone consisting only of repeating units of formula (I) can be used as is, or it can be activated by a known organic chemical reaction by changing it to another functional group. It is reacted with a copolymer having a terminal and having at least one type of repeating unit selected from (n) to (IV) together with the repeating unit of (I). Next, the repeating units (II) to (rV) are selectively sulfonated by a known method.

In addition, when a vinyl polymer is used as the hydrophilic polymer B, for example, a hydrophobic aromatic polymer having a phenolic hydroxyl group at the end is combined with a vinyl group-containing polymer and a radical polymerization initiator. The desired block copolymer can be produced by carrying out the reaction below (Japanese Patent Application No. 196696/1983).

In addition to the hydrophilic-hydrophobic graft copolymer or block copolymer and polysulfone polymer synthesized by the method described above, the separation membrane of the present invention also contains a second compound as described above.
of hydrophilic polymer C is added. If this hydrophilic polymer C is compatible with the polysulfone polymer, it will have heat resistance and hydrophilic properties that are close to the goals of the present invention even when blended alone with the polysulfone polymer without the intervention of a graft copolymer or block copolymer. In some cases, it may be possible to obtain a separation membrane with different characteristics.

For example, JP-A-61-40 disclosed by the present inventors
That's number 2. However, there are very few hydrophilic polymers that have good compatibility with polysulfone polymers. In many cases, they are incompatible, and a simple blend of an incompatible hydrophilic polymer and a polysulfone polymer results in an extremely heterogeneous film that is not suitable for practical use.

By the way, in general, when the compatibility between polymer (1) and polymer (2) is not good, a third polymer (2) may be added as a compatibilizer. It is known that copolymers, especially block and graft copolymers, which have a repeating unit of

The present inventors applied this to film formation, and used polysulfone polymer, hydrophilic polymer C, and the aforementioned hydrophilic-hydrophobic block or graft copolymer to make them compatible as membrane materials. It was possible to obtain a heat-resistant and hydrophilic separation membrane, which is the goal of the present invention. In addition, particularly good results were obtained when a conventional dry, dry-wet, or wet phase conversion film-forming method was used as the film-forming method. In other words, during the phase transformation process during membrane formation, the phase separates into a region rich in polysulfone polymer components and a region rich in hydrophilic components, and finally the microporous surface of the separation membrane is covered with hydrophilic components, making the membrane resistant to contamination. sex is significantly improved. On the other hand, since the polymer matrix that essentially determines the structure of the membrane is mainly formed from polysulfone polymer, the membrane's mechanical strength and heat resistance reach a level comparable to that of polysulfone membranes.

In addition, in order to obtain the membrane targeted by the present invention, the hydrophilic components, that is, the aforementioned hydrophilic polymers B and C, must have a content in the membrane of 8.
It needs to be 0% by weight or less. If this value is exceeded, the interior of the polymer matrix of the membrane will also become significantly hydrophilic, resulting in a decrease in heat resistance and mechanical strength.

In addition, the ratio of the block copolymer or graft copolymer to the hydrophilic polymer C should be adjusted to such an extent that a uniform film-forming polymer solution (described later) can be obtained. It is preferable to minimize the amount of copolymer or graft copolymer added. In addition, the reaction mixture of block copolymers or graft copolymers contains hydrophilic polymers and unreacted polysulfone polymers in addition to the desired copolymer, so the solution of the reaction mixture can be used directly for film formation. It can also be used as a solution.

Next, the above-mentioned phase conversion film forming method will be described in detail. In this film forming method, it is necessary to dissolve the polymer in a suitable solvent, and examples of such a solvent include N,N-dimethylacetamide, N,N-dimethylformamide, N-
Water-soluble solvents such as methyl-2-pyrrolidone, 2-pyrrolidone, dimethyl sulfoxide, sulfolane, and tetrahydrofuran (these are the first group of solvents), and water-insoluble halogenated hydrocarbons such as methylene chloride and chloroform. (these are referred to as the solvents of group Ⅰ).

When using the first group of solvents, dissolve the above-mentioned polymer mixture in it, and if necessary, add an electrolyte, a water-soluble polymer, or a water-soluble poor solvent (for example, water, alcohols, ketones, etc.) at the same time. A solution for film forming by dissolving and mixing (this is called a dope) is prepared. In order to form a separation membrane in the form of a sheet or tube, the dope is placed on a suitable support (e.g. glass plate or tube, nonwoven fabric, cloth, etc.) in the form of a sheet or tube to a thickness of several tens of microns to several hundred microns. After casting by an appropriate method within the range of Or perform wet-dry film formation. Further, a hollow fiber membrane can be manufactured by spinning the dope through a hollow fiber forming nozzle using a known method.

In addition, when using the solvent of Group Ⅰ, the dope prepared in the same manner as in Group 1 is cast or discharged in the form of a sheet, a tube, or a hollow fiber in the same manner as in Group 1, By exposing the membrane to ambient air under certain conditions for a certain period of time to cause liquid-liquid phase separation and further evaporating the solvent, a relatively porous separation membrane can finally be obtained. This method is almost the same as the dry film forming method for cellulose acetate membrane filters.

〔Effect of the invention〕

In the separation membrane made of the modified aromatic resin of the present invention, the microporous surface of the membrane is highly hydrophilic, but the polymer matrix that substantially determines the structure of the membrane is mainly composed of polysulfone polymer. ) It has a phase-separated structure. As a result, the membrane of the present invention has a high water permeation rate and is resistant to dirt, and at the same time has a high mechanical strength.
Its heat resistance, chemical resistance, etc. are comparable to those of conventional aromatic polysulfone membranes. Therefore, it can be effectively used in membrane separation operations under harsh conditions that conventional separation membranes mainly made of hydrophilic polymers (e.g., cellulose acetates or hydrophilized polysulfone membranes made by conventional methods) cannot withstand. It has advantages.

〔Example〕

EXAMPLES Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Polyethersulfone (abbreviated as PES) (Vi
ctrex 5003P, manufactured by ICI Corporation) was dissolved in 70 ml of dimethyl sulfoxide (DMS [abbreviated as 1]), 15 g of vinylpyrrolidone was added, stirred, and N2 gas was blown into the solution for 10 minutes. After heating this solution to 70°C,
0.38 g of azobisisobutyrolitrile was added and stirred for 4 hours. After returning to room temperature and adding 0.2 g of hydroquinone, 50 g of solution was collected. This solution contains high molecular weight type PES (Vict
rex 5200P, manufactured by IC1 > 10 g,
A solution consisting of 030 g of DMS and 10 g of acetone was mixed and stirred day and night to obtain a homogeneous solution. After filtering and degassing this solution, a polyester nonwoven fabric (MF-80K) was used.

(manufactured by Nippon Vilene Co., Ltd.) to a thickness of 150 μm,
After being exposed to a certain atmosphere for a certain period of time, an asymmetric separation membrane was obtained by immersing it in water at 10°C. Furthermore, 90℃
After washing with hot water for 15 minutes, the pure water permeability coefficient (L,)
, L, and the elimination rate (Ro) of bovine serum albumin were measured. The definitions of each parameter are as follows.

(However, the paste after 1 hour of filtration is called B, and the paste after a hour is called L3.) Then, after Soxhlet extraction with water, it was dried and heated to 270MHz'H.
- When analyzed by NIAR and organic solvent-based GPC, it was found to be a block copolymer having the following structure.

-f-CH2CH→yr CH2CH0 As a result Ri2=
8.7 m'/m'-day/kg/cm2. β=6.5
% and R, = 100%.

In addition, this separation membrane is dried and the membrane material polymer is DIJS.
O-d, dissolved in (deuterated DMSO), IH-N
Analysis by F, 4R (100 MHz) revealed that 28% by weight of polyvinylpyrrolidone (PVP) component was present. When this was further extracted with an aqueous acetone solution, the PvP component was reduced to 16% by weight, and it was found that the PvP homopolymer (ie, hydrophilic polymer C) was contained at 12% by weight.

In addition, the remainder of the above reaction mixture was reprecipitated with water, and the high molecular weight type PES (V 1c
A separation membrane was formed in the same manner as in Example 1 from only a solution of trex5200P). This separation membrane is Ll! =9.6
m3/m2·day·kg/cm2, but β=20%, and the pure water permeation rate is significantly reduced.

Example 2 PES of formula (I) whose terminal is a hydroxyl group (V 1ctr
ex52003P) 200g in DMSO600mj2
and PhCn 300- at room temperature, and 50 liters of 0.5N NaOH aqueous solution was added to this. and stirred at room temperature for 2 hours, and the end was sodium ferulate type 0P.
A solution of ES was obtained.

After adding 4 g of benzyl chloride to this, it was heated at room temperature for 7 hours.
The mixture was stirred at 0° C. for 2 hours to convert one end of PES into a benzyl ether type. 0.5N-NaOH50- was added dropwise to this solution, and after stirring for 1 hour, 6 g of chloromethylstyrene was added dropwise, and the reaction was carried out at room temperature for 1 hour and at 70°C for 3 hours to introduce a vinyl group to the other end of PES. . This reaction mixture was reprecipitated with a mixed solution of methanol/water (8:2 (volume ratio)), and the polymer was collected by filtration and dried. When this polymer was analyzed by 'HNMR at 270 MHz, it was confirmed that it was a PES macromer having a benzyl ether group introduced at one end and a vinyl group (styryl group) introduced at the other end.

This P[ES macromer 170g and vinylpyrrolidone 1
70g in DMSO800I! was dissolved in water, and N2 gas was blown into the solution. This solution was heated to 70° C., 2.1 g of azobisisobutyronitrile was added as a polymerization initiator, and polymerization was carried out for 5 hours. After returning to room temperature and adding 2 g of hydroquinone,
0 g of the solution was collected and transferred to Victrex as in Example 1.
The mixture was mixed with 50 g of a solution of 5200P to obtain an asymmetric separation membrane in the same manner as in Example 1. This membrane is LA = 12m3
/m2・day・kg/cm', β=1.2%,
It had excellent water permeability. Also, R of this separation membrane is 100
%, and this performance remained unchanged even after being immersed in hot water at 80°C for 30 days. In addition, compositional analysis of this separation membrane was performed in the same manner as in Example 1, and the PVP component was 28% by weight, of which 19% by weight was PVP in the graft copolymer having the following characteristics, and 9% by weight. % was PvP homopolymer.

Pu5-PVP graft copolymer: IJW = 140.000 MN = 70,000 MW/MN = 2.0 PVP content 37% by weight Example 3 25 g of the block copolymer of Example 1, PVP homopolymer (molecular weight 40 .000, manufactured by Aldrich) 25g,
Victrex 5200P 150g in DMSo
600 g and polyethylene glycol (PEG abbreviated) with an i molecular weight of 200,200 g in a mixed solvent to obtain a uniform film-forming solution (dope). After filtering and defoaming this dope,
Extruded from an annular nozzle for manufacturing hollow fibers, D is inside the hollow fibers.
! , IS O/water = 1 l (weight ratio) was sent to cause solidification, and water was applied from the outside as a coagulation liquid to cause solidification.

The inner diameter of the obtained hollow fiber membrane was 530 μm, and the membrane thickness was 150 μm.
m, Ij = 17m3/112-day kg/cm2
．． It had excellent performance of β=1.0% and R0=100%.

The content of PVP homopolymer in the film was 10% by weight (14% by weight when combined with PvP in the block copolymer).

Comparative Example 2 A hollow fiber membrane was produced in the same manner as in Example 3 except that the block copolymer was not added. This membrane p-47m3
/m2・day・kg/cm', β=10% and R,=
The performance was 95%, which was inferior to that of the membrane of Example 3. The content of PvP homopolymer in the film was as low as 3% by weight.

Example 4 60g of acrylic acid instead of 170g of vinylpyrrolidone
The macromer was polymerized in the same manner as in Example 2, except that the reaction mixture was reprecipitated with water, and then Soxhlet-extracted with water for 30 hours. This was vacuum dried and 'H-NMR and G
When analyzed by PC, it was found that in addition to unreacted PES, it contained 25% by weight of a graft copolymer having the following characteristics.

PE5-FAA” graft copolymer: MW=770.
000 FAA content 14% by weight Trunk polymer: PAA, MW = 108.000 Branch polymer: PES, 'a = 15.000 Number of branches = 44 PAA: polyacrylic acid 25 g of polymer product containing this graft copolymer A dope was prepared in the same manner as in Example 3, except that 25 g of the block copolymer of Example 1 was used, and a hollow fiber membrane was produced. The inner diameter of the hollow fiber membrane obtained was 500 μm.
, the film thickness was 150 μm, and had excellent performance of lj-15m3/m''・day・kg/cm2.β-0% and R,=100%. The percentage was 10% by weight, and the FAA component was 0.5% by weight.

Example 5 A dope was prepared in the same manner as in Example 3, except that 10 g of FAA homopolymer (polymerization degree = 709, manufactured by Nippon Pure Chemical Industries, Ltd.) was used instead of 25 g of PVP homopolymer, and a hollow fiber membrane was produced. The inner diameter of this membrane is 550 μm, and the thickness is 14
At 0 μm, 14 = 20 m3/m2・day・kg/cm
2. It had excellent performance with β=0% and R,=100%. The content of the FAA homopolymer in the film was 5% by weight, and the content of the PVP component was 4% by weight.

Claims (5)

[Claims] (1) A resin containing a hydrophilic-hydrophobic graft copolymer or a block copolymer consisting of a hydrophobic aromatic polymer A and a hydrophilic polymer B together with a hydrophilic polymer C and a polysulfone resin D, the resin From a modified aromatic resin in which the hydrophilic polymer component of B and C combined is 80% by weight or less of the total resin component, and the hydrophobic polymer component of A and D combined is 20% by weight or more of the total resin component. A modified separation membrane characterized by: (2) The modified separation membrane according to claim 1, which is produced by a phase conversion method from a solution of a modified aromatic resin. (3) The hydrophobic aromatic polymer A is a homopolymer having a repeating unit of the following formula (I), or a repeating unit of the formula (I) together with at least one member selected from the following formulas (II) to (IV).
The modified separation membrane according to claim 1, which is a copolymer having repeating units of various types. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) ▲Mathematical formulas , chemical formulas, tables, etc.▼...(IV) (4) The modified separation membrane according to claim 1, wherein each of the hydrophilic polymers B and C has one or more of the following structures as a hydrophilic component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [Here, R_1 is hydrogen or a methyl group. Also, R_2 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (R_3 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms), ▲ ▲ has mathematical formulas, chemical formulas, tables, etc. ▼ (M is hydrogen or carboxylic acid It is an alkali metal or basic substance that forms an ionic bond with ions.), ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R_4 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms.), ▲Mathical formulas, There are chemical formulas, tables, etc. ▼ (R_5 and R_6 each represent hydrogen or 1 to 20 carbon atoms.
It is an aliphatic hydrocarbon group having . ), ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. It is a metal or a basic substance.), ▲ Formula,
There are chemical formulas, tables, etc.▼ (R_1, R_8 and R_9 each represent 1 or 2 carbon atoms.
It is an aliphatic hydrocarbon group having 0 atoms, and X^■ is a halogen ion. ), ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1_0 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, n is an integer from 4 to 6, and X^■ is a halogen ion.), ▲ Formula There are , chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1_1 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and X^■ is a halogen ion.) . ] (5) The polysulfone resin D is a homopolymer having a repeating unit of the following formula (I), or a copolymer having at least one repeating unit selected from formulas (II) to (IV) together with the repeating unit of the formula (I). The modified separation membrane according to claim 1, which is a polymer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) ▲Mathematical formulas , chemical formulas, tables, etc.▼...(IV)