JP2001276588A - Semipermeable membrane and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semipermeable membrane having both high desalting capability and high permeability. SOLUTION: A solution containing a sulfone derivative represented by the formula (wherein R1 is a 1-5C alkyl; and R2 to R4 are each H or a 1-5C alkyl) is applied to a porous substrate, and then the derivative is polymerized to form a separation-functional layer on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semipermeable membrane having both high desalination and high water permeability, and a method for producing the same.

[0002]

2. Description of the Related Art Composite semipermeable membranes made of polyamide are used in various fields because they have higher desalination performance and water permeability than conventionally known asymmetric membranes made of cellulose acetate. I have. However, since the above-mentioned conventional composite semipermeable membrane has an amide bond in the main chain,
There was a problem that the durability was insufficient, the membrane was deteriorated by contact with chlorine or hydrogen peroxide used for sterilization of the membrane, and the separation performance such as desalination was reduced. Therefore, when operating a membrane separation device using these composite semipermeable membranes,
There were various restrictions on the sterilization method and the like. In order to solve such a problem, for example, Japanese Patent Publication No. 5-27447 discloses a film in which an amide bond is not introduced into the main chain, but the film is still damaged by abrasion. And there is a problem that the separation performance such as desalination tends to decrease.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a semipermeable membrane having both high desalination and high water permeability, and a method for producing the same. .

[0004]

Means for Solving the Problems The present invention for achieving the above object provides a half-finished structure in which a separation functional layer having a polymer containing a structural unit represented by the chemical formula (1) is provided on a porous support. Characterized by a permeable membrane.

[0005]

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(R ¹ : alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or alkyl group having 1 to 5 carbon atoms) Here, the membrane of the separation function layer It is also preferred that the thickness is in the range from 10 nm to 100 μm.

[0007] A spiral type semipermeable membrane element formed by winding a membrane unit including a stock solution channel material, a permeate solution channel material, and the above semipermeable membrane around a water collecting pipe is also preferable. A desalination method of treating raw water using a permeable membrane or a spiral type semipermeable membrane element is also preferable.

Further, the present invention is characterized by a sulfone derivative represented by the chemical formula (2).

[0009]

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(R ¹ : alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or alkyl group having 1 to 5 carbon atoms) A method for producing a semipermeable membrane, in which a solution containing the compound is placed on a porous support and then the sulfone derivative is polymerized to form a separation functional layer on the porous support, is also preferable.

Further, a method for producing the above-mentioned sulfone derivative in which the compound represented by the chemical formula (3) is reacted with the compound represented by the chemical formula (4) is also preferable.

[0012]

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(R: hydrogen or an alkyl group having 1 to 5 carbon atoms)

[0014]

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(R ^{1 to} R ³ : hydrogen or an alkyl group having 1 to 5 carbon atoms X: F, Cl, Br or I)

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The semipermeable membrane according to the present invention is provided with a separation functional layer having a polymer containing a structural unit represented by the following chemical formula (1) on a porous support.

[0017]

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(R ¹ : an alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or an alkyl group having 1 to 5 carbon atoms) Since the above-mentioned constituent units are contained in the separation functional layer, a rigid cross-linking structure based on having a sulfone skeleton which is a rigid chemical skeleton as compared with the benzene ring is developed, and high-strength scratches and the like are caused. It is possible to form a separation function layer that is hardly affected by the separation. Therefore, high separation performance can be maintained. Furthermore, since the separation functional layer is simultaneously provided with an ester group, hydrophilicity can be imparted to the separation function layer, and the water permeability of the semipermeable membrane can be improved.

The semipermeable membrane in the present invention is, as described above,
Although it has a structure in which a separation function layer is provided on a porous support, the formation of this separation function layer can be performed by simply laminating a separation function layer separately created on the porous support. Alternatively, the separation may be performed by infiltrating the separation function layer into the pores of the porous support. In the latter case, since the porous support and the separation function layer are firmly joined, the strength of the semipermeable membrane is increased, which is preferable.

The thickness of the separation function layer is 10 nm to 1 nm.
It is preferably within the range of 00 μm, and 20 nm to 10 μm
More preferably, it is within the range of m. If the thickness of the separation function layer is less than 10 nm, defects are likely to occur.
If it exceeds 0 μm, the resistance to a substance that permeates the semipermeable membrane tends to increase.

The thickness of the entire semipermeable membrane is 1 μm to 1 c.
m, more preferably in the range of 10 μm to 2 mm. When the thickness of the semipermeable membrane is less than 1 μm, the pressure resistance tends to decrease, and when it exceeds 1 cm, the amount of the substance per unit volume of the semipermeable membrane tends to decrease, and the membrane performance tends to decrease.

As the above porous support, for example,
A membrane having a large number of fine pores can be used, and a membrane having a flat membrane or a hollow fiber membrane is preferable. Further, as the material of the porous support, polysulfone, polyphenylene sulfide sulfone, polyphenylene sulfone, polyether sulfone, cellulose ester, polyacrylonitrile, polyolefin, polyester, polyvinyl halide, polyvinylidene halide, polyimide,
A homopolymer such as polyamideimide or a copolymer thereof can be used. Among them, it is preferable to use polysulfone, polyphenylene sulfide sulfone, and polyphenylene sulfone because they have high chemical, mechanical, and thermal stability and are easy to mold.
Also, especially when chemical and thermal stability is required,
Polyphenylene sulfide sulfone or polyphenylene sulfone may be used.

This porous support is used to increase the strength.
It is preferably lined with cloth, nonwoven fabric, paper or the like.
As a method for producing the porous support, for example, a solution of polysulfone in dimethylformamide (DMF) is cast to a predetermined thickness on a densely woven polyester cloth or nonwoven fabric, and the solvent on the surface is exposed in air for a predetermined time. After the removal, a method of coagulating in a coagulating liquid such as water can be used.

The production of the semipermeable membrane of the present invention can be carried out by polymerizing a compound represented by the following chemical formula (2) on a porous support to form a separation functional layer.

[0025]

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(R ¹ : alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or alkyl group having 1 to 5 carbon atoms) In the above chemical formula (2) The compound represented can be suitably used as a constituent material of the semipermeable membrane,
It can also be suitably used as a raw material monomer used in medicines and engineering plastics.

The compound represented by the chemical formula (2) can be obtained, for example, by reacting a compound represented by the chemical formula (3) with a compound represented by the chemical formula (4) as shown below. .

[0028]

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(R: hydrogen or an alkyl group having 1 to 5 carbon atoms)

[0030]

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(R ^{1 to} R ³ : hydrogen or an alkyl group having 1 to 5 carbon atoms X: F, Cl, Br or I) This reaction may be carried out in the presence of a solvent. As the solvent to be used, a solvent that sufficiently dissolves the compounds represented by the chemical formulas (3) and (4) as the starting materials and does not easily react with the respective compounds may be used. Specifically, dichloromethane, chloroform, halogenated hydrocarbons such as carbon tetrachloride, pentane, hexane, heptane, aliphatic hydrocarbons such as cyclohexane, benzene, toluene,
A polar solvent such as an aromatic hydrocarbon such as xylene, acetone, tetrahydrofuran, dimethyl sulfoxide, or N-methylpyrrolidine can be used. Among the above, a solvent containing no halogen is preferable, and acetone and tetrahydrofuran are particularly preferable.

In addition, the charge ratio of the compound represented by the chemical formula (3) and the compound represented by the chemical formula (4) in the reaction is such that the compound represented by the chemical formula (4) is added to the compound represented by the chemical formula (3). It is preferable that the molar ratio is in the range of 1 to 10 equivalents,
More preferably, it is in the range of 2.5 to 3.5 equivalents. This is because if the reaction proceeds ideally, the molar ratio is 2 equivalents and there is no excess or deficiency. If the molar ratio is within the above range, the reaction proceeds sufficiently and the purification after the reaction is completed. This is because the process can be performed efficiently.

Further, the reaction temperature is preferably in the range of 5 ° C. higher than the melting point of the solvent used to the boiling point of the solvent, and 5 ° C. higher than the melting point of the solvent to 10 ° C. higher than the boiling point of the solvent. More preferably, it is within a low temperature range. When the reaction temperature is higher than the above range,
The reaction rate tends to increase and control tends to be difficult.

The reaction time may be determined by monitoring the presence of the compound represented by the chemical formula (3) during the reaction by a thin-layer chromatograph or the like as appropriate, and ending the reaction when disappearance is confirmed. Good. If the reaction time is too long, the reaction product tends to decompose.

By obtaining the semipermeable membrane of the present invention using the above-mentioned compound, a semipermeable membrane having a high level of both separation performance and water permeability can be easily obtained by a commonly used vinyl polymerization method. can do.

The method of polymerizing the sulfone derivative represented by the chemical formula (2) may be a general vinyl polymerization method, and can be performed by addition polymerization such as radical polymerization, anionic polymerization, or cationic polymerization. Specifically, heating, infrared, ultraviolet, X-ray, radiation (electron beam, γ-ray)
Irradiation of energy rays, photopolymerization, ion polymerization, plasma polymerization, etc. The selection of the polymerization method may be appropriately performed depending on the structure of the sulfone derivative represented by the chemical formula (2) or the productivity and cost of each method. However, polymerization by heating that can be performed by a simple apparatus is preferable. . In terms of running costs,
Polymerization by infrared rays or ultraviolet rays is also preferable.

Of the above methods, in the case of polymerization by heating, the polymerization is preferably carried out at a temperature in the range of 20 to 300 ° C., more preferably 30 to 200 ° C., from the viewpoint of productivity and cost. . Further, the treatment time is preferably in the range of 1 second to 1 day, and more preferably in the range of 10 seconds to 8 hours, from the viewpoint of productivity, polymerization efficiency, cost and the like. As a heating method, a method using heat transfer, radiation, or convection can be used. Of course, these methods may be used alone or in combination.

When the sulfone derivative represented by the chemical formula (2) is polymerized, it has a dense structure due to a crosslinking reaction. In order to control the degree of the crosslinking, that is, the crosslinking density, the chemical formula (2) A monomer having addition polymerizability other than the sulfone derivative represented by formula (1) may be present during the above polymerization. In this case, it is preferable that the content ratio of the monomer having addition polymerizability is 10 to 90% by weight based on the total amount of the monomers. If it is less than 10% by weight, the control of the crosslinking density tends to be insufficient,
On the other hand, if it exceeds 90% by weight, it is difficult to achieve both desalination performance and water permeability performance.

With the above content ratio, it is possible to obtain a separation functional layer in which the content of the structural unit represented by the chemical formula (1) is in the range of 10 to 90% by weight based on the whole polymer. .

Examples of the monomer having addition polymerizability include a vinyl derivative having a group such as a vinyl group, a vinyl halide group and a vinyl ester group, and an acrylic derivative having a group such as an acryl group and a methacryl group. Can be used. Among them, acrylic derivatives are preferred from the viewpoints of compatibility with various solvents and chemical stability of reaction products. Specific examples of the above compound, as a compound having a vinyl group, ethylene, propylene, butene,
Pentene, styrene, vinyl sulfone, p-chlorostyrene, p-cyanostyrene, p-fluorostyrene, p
-Methylstyrene, p-methoxystyrene, sodium o-styrenesulfonate, sodium p-styrenesulfonate, sodium m-styrenesulfonate, o-aminostyrene, m-aminostyrene, p-aminostyrene, 2-methyl-5 -Vinylpyridine, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, N-
Vinylcarbazole, vinylamine, 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, N-vinyl-2-pyrrolidone, 1-vinylimidazole, butadiene, 4-vinylstyrene, N-methylmaleimide,
Dipropylene ether, divinylethylene glycol and the like can be used. Further, as the compound having a vinyl halide group, vinyl fluoride, vinyl chloride, vinylidene chloride, ethylene tetrafluoride and the like can be used, and as the compound having a vinyl ester group, vinyl benzoate, vinyl acetate and the like can be used. Further, as a compound having an acrylic group or a methacrylic group, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, acryloylmorpholine, methoxyethyl acrylate , Ethoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxypropylene glycol acrylate, methoxydipropylene glycol acrylate, tetrahydrofurfuryl acrylate, 2-acryloyl Roxyethyl succinic acid Methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methacryloylmorpholine, methoxyethyl methacrylate, ethoxyethyl methacrylate , Methoxydiethylene glycol methacrylate, ethoxydiethylene glycol methacrylate, methoxytriethylene glycol methacrylate, methoxytriethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methoxypropylene glycol methacrylate,
Methoxy dipropylene glycol methacrylate, tetrahydrofurfuryl methacrylate, 2-methacryloyloxyethyl succinic acid, triethylene glycol diacrylate, hexaethylene glycol diacrylate, nonaethylene glycol diacrylate, triethylene glycol dimethacrylate, hexaethylene Glycol dimethacrylate, nonaethylene glycol dimethacrylate, pentaerythritol triacrylate, and the like can be used. Among the above, it is preferable to use acrylic acid or a derivative thereof having excellent compatibility with a solvent and high stability of a polymerization reaction product.

In order to polymerize the monomer on the porous support, for example, a solution of the monomer to be polymerized, such as the compound represented by the chemical formula (2), is applied or impregnated on the porous support, They can be carried out by polymerizing them. As described above, the polymerization itself may be carried out by heating, in addition to heating, or by independently irradiating energy rays such as ultraviolet rays and radiation.

The solvent used for the above-mentioned monomer solution is preferably a solvent in which the monomer is soluble and which does not easily react with the monomer or the porous support. Specifically, alcohols such as methanol, ethanol, and isopropyl alcohol, dichloromethane, dibromomethane, chloroform, bromoform, halogenated hydrocarbons such as carbon tetrachloride, hydrocarbons such as benzene, hexane, and cyclohexane, and water can be used. it can. Water is preferred from the viewpoints of safety, availability, and the like.

The concentration of the whole monomer in the solution is
It is preferably in the range of 0.01 to 50% by weight, and 0.1 to 50% by weight.
More preferably, it is in the range of 1 to 20% by weight. When the concentration is less than 0.01% by weight, defects are likely to be generated in the separation function layer, and when the concentration is more than 50% by weight, resistance to a substance permeating the membrane is increased and membrane performance is apt to be reduced.

The method of applying or impregnating the monomer solution onto the porous support includes impregnating the porous support with the solution, dip coating, roll coating, spraying, and discharging the solution from a die. And the like. After coating or impregnating the porous support, it is also preferable to remove excess solution by tilting the porous support or spraying a gas onto the porous support.

Further, the separation function layer is made thin and uniform.
As a method of forming without causing defects such as pinholes, the monomer or the solution used in the polymerization is not compatible or soluble in the solution, or a liquid or solid that does not mix with the above solution, It is also preferable to carry out polymerization at the interface. For example, a method of arranging a polyester film or the like on a porous support and injecting the above solution into a gap between the two can be used. At this time, the interface is set in the porous support or on the porous support.

In the above-mentioned polymerization, various polymerization initiators, polymerization accelerators, polymerization aids, polymerization inhibitors and other additives may be present. Preferably, an initiator or a polymerization accelerator is present. Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile, peroxides such as benzoyl peroxide, benzophenone, and Nippon Kayaku Co., Ltd.
benzophenone derivatives such as Ayacure (registered trademark) BP-100 "," Kayacure (registered trademark) BMS ", 1- (4- (2-hydroxyethoxy) -phenyl) -2-hydroxydi-2-methyl -1-propan-1-one and "Irgacure (registered trademark) 2959", "Irgacure (registered trademark) 184", and "Irgacure (registered trademark) 9" manufactured by Ciba Geigy.
07, Irgacure (registered trademark) 651, Irgacure (registered trademark) 369, and Irgacure (registered trademark) 1173.
Thioxanthone derivatives such as -diethylthioxanthone and 1-chloro-4-propoxythioxanthone;
LUSCILLIN (LUC) manufactured by AS F (BASF)
Acylphosphine oxide derivatives such as IRIN) ® TPO ", benzoin ether derivatives such as benzoin isobutyl ether, redox initiators,
Aromatic diazonium salts, bissulfonium salts, aromatic iodonium salts, aromatic sulfonium salts, potassium persulfate, ammonium persulfate, alkyl lithium, cumyl potassium, sodium naphthalene, distyryl dianion, and the like can be used. Among them, it is preferable to use an azo compound, a benzophenone derivative, an acetophenone derivative, or an acylphosphine oxide derivative which is easy to handle.

The concentration of the polymerization initiator may be appropriately determined depending on the type of the monomer, the temperature, the reaction time, the polymerization conditions and the like.
It is preferably in the range of 0% by weight, more preferably in the range of 0.01 to 5% by weight. When the concentration is less than 0.001% by weight, the polymerization reaction becomes difficult to proceed,
If the content exceeds% by weight, a polymer as a reaction product contains a large amount of a polymerization initiator, and the performance of the semipermeable membrane tends to decrease.

As the polymerization accelerator, a photosensitizer or a photopolymerization accelerator can be used. As a photosensitizer,
Eosin or camphorquinone can be used.
As the photopolymerization accelerator, N-methyldiethanolamine, N, N-dimethylaminomethacrylate, N,
N-dimethyl-p-toluidine, 2,4,6-tris (trichloromethyl) -s-triazine, isoamyl-
p-Dimethylaminobenzoate, manufactured by Nippon Kayaku Co., Ltd., "Kayacure (registered trademark) DM"
For example, aromatic tertiary amine derivatives such as "BI" and "Kayacure (registered trademark) EPA" can be used.

The concentration of the polymerization accelerator may be appropriately determined depending on the type of the monomer, the temperature, the reaction time, the polymerization conditions and the like.
It is preferably in the range of 0% by weight, more preferably in the range of 0.01 to 5% by weight. When the concentration is less than 0.001% by weight, the promotion of the polymerization reaction tends to be insufficient,
On the other hand, when the content exceeds 10% by weight, a polymer as a reaction product contains a large amount of a polymerization accelerator, and the performance of the semipermeable membrane tends to decrease.

The above polymerization initiators and polymerization accelerators may be added to the monomer solution from the beginning and mixed, a method of preliminarily coating or impregnating the support, a method of coating after the monomer is coated, and the like. Can be used.

As long as the semipermeable membrane of the present invention is formed in a flat membrane shape, it can be used by incorporating it into a spiral, tubular, or plate-and-frame semipermeable membrane element. In addition, as long as they are formed in a hollow fiber shape, they can be bundled and incorporated into an element. For example, in the case of a spiral type semipermeable membrane element, a membrane having a rhombic structure is used as a stock solution channel material, and a nonwoven fabric or the like is used as a permeated water channel material to form a membrane unit together with the semipermeable membrane of the present invention. Alternatively, a structure in which the membrane unit is wound around the water collecting pipe can be employed. In this case, the membrane unit has a structure in which a permeated liquid flow path material is disposed inside a bag-shaped semipermeable membrane having one open end, and a raw liquid flow path material is disposed outside. By joining the opening so as to cover the hole formed in the water collecting pipe, the raw water flowing from the outside is filtered through a semipermeable membrane, collected in the water collecting pipe, and taken out to the outside.

Further, it is also possible to connect a plurality of these elements in series or in parallel and incorporate them in a pressure vessel to use as a semipermeable membrane module.

When a liquid is separated using the above-described elements and modules, the pressure difference between both surfaces of the semipermeable membrane is 0.01
Preferably in the range of 20 to 20 MPa, and 0.1 to 10 MPa.
More preferably, it is within the range of MPa. 0.01MPa
If it is less than, it becomes difficult to sufficiently exert the separation performance, and 20
If it exceeds MPa, the semipermeable membrane may be deformed and the separation performance may be reduced.

In the separation membrane of the present invention, an aqueous solution or a solution containing an organic substance can be used as a target (liquid to be treated) for selective separation. In particular, it can be suitably used for aqueous solutions, and is effective for use in extracting fresh water from highly concentrated brackish water or seawater.

[0055]

The present invention will be described in more detail with reference to the following examples.

In the following examples, the exclusion rate of the semipermeable membrane was calculated by equation (A), and the permeation flux was calculated by equation (B).

Rejection rate (%) = ((solute concentration of feed solution−solute concentration of permeate solution) / solute concentration of feed solution) × 100 (A) Permeate flux (m ³ · m ^−2. d ^-1 ) = (permeate per day) / (membrane area) (B) (Example 1) bis (4-hydroxyphenyl) sulfone (10 mmol, 2.5 g) in 50 ml of acetone Potassium carbonate (4.0 g) was added, and acryloyl chloride (39 mmol, 2.0 g) was added dropwise at 25 ° C.
After stirring for 4 hours, the solvent was distilled off under reduced pressure and redissolved in ethyl acetate. This solution was separated and washed with water, dried again, and then dried under vacuum to obtain 2.9 g of bis (4-acryloxyphenyl) sulfone. The analytical values of this compound are shown below.

¹ H-NMR (dimethyl sulfoxide-
d ₆ , 270 MHz) δ ppm: 7.66 (s, 4
H), 6.69 (d, J = 16.2 Hz, 2H), 6.
36 (m, J = 17.1 Hz, 2H), 6.08 (d,
J = 9.9 Hz, 2H), 2.20 (s, 12H) IR (KBr): 790, 888, 976, 1,05
0, 1,233, 1,308, 1,455, 1,57
3,1,600,1,658,1,699,3,088
cm ^-1 . (Example 2) Taffeta made of polyester fiber having a length of 30 cm and a width of 20 cm (167 dt for both warp and weft)
ex (150 denier) multifilament yarn, woven density warp 90 yarns / inch, weft 67 yarns / inch, thickness 16
0 μm) was fixed on a glass plate, and a 15% by weight dimethylformamide (DMF) solution of polysulfone (Udel P-3500 manufactured by Amoco KK) was placed on the glass plate at 200 μm.
At a room temperature (20 ° C.), immediately immersed in pure water and left for 5 minutes to prepare a fiber-reinforced porous membrane (porous support). The pure water permeation coefficient of the thus obtained fiber-reinforced porous membrane was 0.1 MPa
a, when measured at a temperature of 25 ° C., 0.5 to 1 (g · cm
⁻² · sec ⁻¹ · MPa ⁻¹ ). 6.5% by weight of bis (4-hydroxyphenyl) sulfone and 3.5% by weight of "9EG-A" (a polyfunctional acrylic monomer manufactured by Kyoeisha Chemical Co., Ltd.) ,
It was immersed in an aqueous solution containing 0.2% by weight of "Irgacure 2959" (initiator manufactured by Ciba Geigy) and 0.1% by weight of sodium lauryl sulfate for 5 minutes. The porous film is pulled up at a pulling rate of 20 cm / min, and the wavelength is 172 n.
m, using an excimer lamp of 20 W, irradiating ultraviolet rays for 30 seconds with the shortest distance between the lamp and the porous film being 1 cm,
Polymerization was performed to prepare a semipermeable membrane in which a layer (separation functional layer) made of a polymer was provided on a porous support.

The semipermeable membrane thus obtained is subjected to pH
A 1,500 ppm aqueous solution of NaCl adjusted to 6.5 was used as raw water, and reverse osmosis was evaluated under the conditions of an operating pressure of 1.5 MPa and a temperature of 25 ° C. As a result, the exclusion rate was 68%, and the permeation flux was 0.46 m. ^{It was 3} · m ^-2 · d ^-1 . (Comparative Example) Except that 6.5% by weight of 1,3,5-triacrylhexahydro-1,3,5-triazine was used instead of 6.5% by weight of 3,5-diacrylamidobenzoic acid, and A semipermeable membrane was obtained in the same manner as in Example 1.

The semipermeable membrane thus obtained was treated at pH 6.
Using a 1,500 ppm aqueous solution of NaCl adjusted to 5 as a raw water, reverse osmosis was evaluated under the conditions of an operating pressure of 1.5 MPa and a temperature of 25 ° C. As a result, the exclusion rate was 20%, and the permeation flux was 3 m.
^{It was 3} · m ⁻² · d ⁻¹ , and the rejection was significantly inferior to Example 1.

[0061]

According to the present invention, since the separation functional layer has a sulfone skeleton, which is a rigid chemical skeleton, the separation functional layer can be formed with high strength and not easily damaged by abrasion. And a semipermeable membrane having high separation performance can be obtained. In addition, since it contains an ester group, high permeability, especially high water permeability, can be imparted to the separation function layer, and a semipermeable membrane having both high separation and high permeability can be obtained. .

Since the sulfone derivative of the present invention has two polar functional groups and four double bonds in one molecule, it can be easily used as a polyfunctional monomer, and can be used for pharmaceuticals and engineering plastics. Very useful as a raw material. In addition, by performing the polymerization of the polyfunctional monomer using a non-halogen solvent, it is possible to suppress the discharge of halogens and provide a polymerization method with less harmfulness.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 317/22 C07C 317/22 C08F 2/00 C08F 2/00 C 20/38 20/38 F term (reference 4D006 GA02 GA03 HA01 HA21 HA42 HA61 KE06Q MA01 MA03 MA06 MA07 MA31 MB02 MB06 MC17 MC22 MC25 MC39 MC48X MC54 MC58 MC61 MC62 MC63X NA42 NA46 PA02 PB03 PB04 PB05 4H006 AA01 AA02 AB46 AC48 TA02 TB13 TB03 4J01Q04 AL03 BA58P BC43P CA01 CA04

Claims (7)

[Claims] 1. A semipermeable membrane comprising a porous support and a separation functional layer having a polymer containing a structural unit represented by the chemical formula (1) provided thereon. (R ¹ : alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or alkyl group having 1 to 5 carbon atoms) 2. The separation function layer has a thickness of 10 nm to 100 μm.
2. The semipermeable membrane according to claim 1, which is in the range of m. 3. A spiral type wherein a raw liquid flow path material, a permeated liquid flow path material, and a membrane unit including the semipermeable membrane according to claim 1 or 2 are wound around a water collecting pipe. Semi-permeable membrane element. 4. A fresh water producing method comprising treating raw water using the semipermeable membrane according to claim 1 or 2, or the spiral type semipermeable membrane element according to claim 3. 5. A sulfone derivative represented by the formula (2). Embedded image (R ¹ : alkyl group having 1 to 5 carbon atoms R ^{2 to} R ⁴ : hydrogen or alkyl group having 1 to 5 carbon atoms) 6. A method comprising disposing a solution containing the sulfone derivative according to claim 5 on a porous support, and polymerizing the sulfone derivative to form a separation functional layer on the porous support. Method for producing a semipermeable membrane. 7. The method for producing a sulfone derivative according to claim 5, wherein the compound represented by the chemical formula (3) is reacted with the compound represented by the chemical formula (4). Embedded image (R: hydrogen or an alkyl group having 1 to 5 carbon atoms) (R ^{1 to} R ³ : hydrogen or an alkyl group having 1 to 5 carbon atoms X: F, Cl, Br or I)