JP3236754B2 - Mosaic charged membrane, manufacturing method thereof, desalination method and desalination apparatus using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mosaic charged membrane, and more particularly to a mosaic charged membrane useful for separating an electrolyte from a non-electrolyte or desalting a salt solution.

[0002]

2. Description of the Related Art A mosaic charged membrane in which cationic domains and anionic domains are alternately arranged allows a low-molecular-weight electrolyte to be dialyzed through a membrane, but a non-electrolyte cannot be dialyzed or is extremely dialyzed. It is a functional membrane that only slightly dialyses. For example, there are great expectations for desalination and desalination of seawater and the like, or in the field of biotechnology, and various studies have been made. by the way,
As a method of forming a mosaic pattern, block copolymers AC and B- with a C polymer each containing one of an A polymer and a B polymer that are incompatible with each other are used.
A method in which C is subjected to microphase separation, the amount of each block copolymer is adjusted to form a lamella or cylinder structure, and then cationic and anionic functional groups are introduced;
A mosaic pattern is formed on a support, and a cationic substance and an anionic substance are formed thereon by epitaxy.
xy) method.

[0003]

In the above method, when the phase separation of the block copolymer is used, the formation of a lamella or cylinder structure requires the quantitative restriction of the two kinds of copolymers to be mixed or the anisotropic structure. Due to the nature, it is technically difficult to make different ionic polymers contact each other with respect to the cross section of the membrane and penetrate with the same ionic polymer phase on the front and back of the membrane. In addition, introducing a cationic or anionic functional group after forming a lamella or cylinder structure requires a complicated process, and the amount of such a functional group is also limited. In the epitaxy method, very strict control is required to grow an ionic substance on a mosaic pattern, and there is a problem in preparing a large-area film. In any of the methods, the film formed has a small area, and has a low mechanical strength because it is extremely thin, and is inferior in pressure resistance.
In addition, there is a problem in industrially producing a membrane having excellent separation performance.

A method for solving this problem is disclosed in Japanese Patent Laid-Open No. 5-84.
430, JP-A-6-107798, JP-A-6-262047, and the like have proposed a method for manufacturing a mosaic charged film using a spherical polymer by a simple method and easy control. Although the separation performance of the mosaic charged membrane obtained by these methods is good, there is a problem that the pressure resistance is poor. Therefore, an object of the present invention is useful for separating an electrolyte and a non-electrolyte or for desalting a salt solution, and further, has a sufficient pressure resistance, a large area, and a sufficient mechanical strength. The object of the present invention is to provide a mosaic charged film body that can be manufactured by a simple process.

[0005]

The above object is achieved by the present invention described below. That is, the present invention relates to an asymmetric porous body comprising a cationic polymer, an anionic polymer and a support, wherein the support comprises a pore layer and a support layer, and both polymers are dialyzed on the pore layer. Mosaic charged membrane, characterized by being capable of being filled, its production method,
A desalination method and a desalination apparatus using the membrane.

[0006]

[Action] In mosaic charged membrane of the present invention, the cationic and anionic polymers, for example, as a preferred embodiment, using each as the cationic and anionic spherical polymer, further, the pores as a support
To provide a mosaic charged membrane having a sufficient pressure resistance, a large area, and a sufficient mechanical strength by a simple process by using an asymmetric porous body composed of a layer and a support layer. Can be.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The cationic polymer used in the present invention is a polymer having a salt group such as a primary to tertiary amino group, a quaternary ammonium base, or a pyridinium group, and the anionic polymer is sulfonic acid, carboxylic acid, sulfate, It is a polymer having a salt group such as a phosphate ester. In the case of a salt group, for a cationic group, for example, an anion such as hydrochloric acid, sulfuric acid, phosphoric acid, or an organic acid is used as a counter ion, and for an anionic group,
For example, a cation such as an alkali metal is used as a counter ion.

The cationic polymer used in the present invention includes polyvinyl pyridine and quaternized products thereof, dimethylaminoethyl poly (meth) acrylate, diethylaminoethyl poly (meth) acrylate, poly4-vinylbenzyldimethylamine, Poly 2-hydroxy-3-
(Meth) acryloyloxypropyldimethylamine and salts thereof. These polymers include:
The above-mentioned crosslinkable monomers or those obtained by further copolymerizing a monomer copolymerizable with the above-mentioned polymer constituent monomer and the crosslinkable monomer are also included.

The anionic polymer used in the present invention includes polystyrenesulfonic acid, poly (meth) acryloyloxypropylsulfonic acid, poly (meth) acrylate sulfopropyl, poly (meth) acrylate-2-sulfoethyl, and poly (meth) acrylate-2-sulfoethyl. 2- (meth) acryloylamino-2
-Methyl-1-propanesulfonic acid, poly 2- (meth)
Examples include acryloylamino-2-propanesulfonic acid, polyvinylsulfonic acid, polyacrylic acid, styrene-maleic acid copolymer, and salts thereof. These polymers also include those obtained by copolymerizing a crosslinkable monomer described below, or a monomer copolymerizable with the polymer constituent monomer and the crosslinkable monomer. Various known methods can be used as a method for producing the polymer as described above, and examples thereof include polymerization methods such as soap-free polymerization, emulsion polymerization, dispersion polymerization, and seed polymerization.

Both the cationic polymer and the anionic polymer used in the present invention have an average particle size of 0.0
1 μm to 10 μm, preferably 0.02 μm to 1 μm
Use as a spherical (particulate) polymer in the range of μm is preferred for the production of the mosaic charged membrane of the present invention. The case where both polymers are used as spherical polymers will be described below. The polymer particles used in the present invention need not necessarily be crosslinked, but are preferably crosslinked from the viewpoint of strength and solvent resistance of the resulting film. In order to crosslink the polymer particles in the process of producing by the above method, divinylbenzene, methylenebis (meth) acrylamide, ethylene glycol dimethacrylate, 1,3-dimethacrylic acid are used as crosslinkable monomers.
Known crosslinkable monomers such as butylene glycol and other tri- and tetrafunctional (meth) acrylates are copolymerized with the above-mentioned monomers constituting the polymer. The crosslinking monomer is 0.1 to 100 parts by weight of all monomers.
It is used in the range of 20 parts by weight, preferably in the range of 0.5 to 10 parts by weight.

The mosaic charged membrane of the present invention is produced by filling the above-mentioned cationic polymer particles and anionic polymer particles into a porous layer of an asymmetric porous material described later as a support. After filling the polymer particles and the anionic polymer particles, the polymer particles may be linked and cross-linked by using (meth)
(Meth) acrylic acid esters having a hydroxyl group such as hydroxyethyl acrylate and hydroxypropyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide and its methoxymethylated and butoxymethylated (meta) ) Acrylamides, glycidyl (meth) acrylate, (meth) acrylic acid and the like are copolymerized with the above-mentioned polymer-constituting monomers and the like. The crosslinking monomer is used in an amount of 1 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the total monomers.

The proportion of the cationic polymer and the anionic polymer used for filling the pore layer of the asymmetric porous material is as follows:
It is preferred that the ratio of the ionic groups of these two different ionic polymer components be equal, but depending on the size of the particles, the cationic polymer / anionic polymer (molar ratio) is 0.5 to 2 A range is preferred. After filling the mixed dispersion of cationic polymer particles and an anionic polymer particles to the asymmetric porous material pore layer of the polymer particles by connecting bridging between inter and as far as possible polymer particles and Hosoanaso polymer particles Chemical fixation is preferred. Examples of the linking crosslinking agent include polyaldehydes represented by glutaraldehyde, haloaldehydes such as chloroacetaldehyde, methylolated melamine and its methyl ether,
Derivatives such as butyl ether, aminoplast resins,
Ethylene urea derivatives and the like are used. Further, dihaloalkanes such as diiodobutane, diiodomethane, dibromobutane and the like, which can simultaneously quaternize the cationic component in the polymer as well as a crosslinking agent, can be used as the cationic component in the polymer.

The amount of the cationic polymer particles and the anionic polymer particles to be filled in the porous layer of the asymmetric porous body is as follows:
Also it varies depending particle size of the porous body having a pore size and these polymers pore layer is in the range of 0.1~1000g / m ^2, preferably in the range from 1 to 500 g / m ^2. When the filling amount is small, the dialysis speed of the membrane increases, but the pressure resistance performance becomes a problem. When the filling amount increases, the dialysis speed of the membrane becomes a problem. The asymmetric porous body used as a support in the present invention is composed of a pore layer (skin layer) on the surface having a separation function and a support layer thereunder, as schematically shown in FIG. A non-uniform porous body in which the pores of the asymmetric porous body are not of the same pore diameter and the same shape.

In a preferred porous body, the pore layer and the support layer are formed of the same material, a very thin pore layer (generally called a skin layer) is formed on the surface, and the rest is in the form of a sponge. And a porous material composed of a support layer of stainless steel, ceramic, glass, cellulose acetate, or the like. It is also possible to use a composite porous material (generally called a composite membrane) in which the material of the porous layer and the material of the support layer are different from each other as the porous material. The support layer is formed of a material such as polyether or polypiperidine amide, and the support layer is formed of a material such as polysulfone. The cationic polymer particles and the anionic polymer particles are filled in the porous layer of the porous body, and the average pore size of the porous layer is preferably equal to or smaller than the average particle size of the polymer used. However, if the polymer particles are filled, it can be used even if it is larger, and the size is in the range of 10 μm or less,
It is preferably in the range of 1 μm or less.

The shape of such an asymmetric porous body includes a flat plate type, a spiral type, a tube type, a hollow fiber type and the like, and the shape can be changed according to required pressure resistance performance and use. When the polymer particles are filled in the pore layer of the asymmetric porous body, the porous layer is used to improve the wettability of the polymer particles to the porous body and facilitate the connection and fixation between the porous body and the polymer particles. It is preferable that the surface of the body is subjected to a hydrophilic treatment. For example, ethylene thioglycol or the like is used for a porous stainless steel.

A method for producing the mosaic charged membrane of the present invention using the above-mentioned cationic polymer particles, anionic polymer particles and an asymmetric porous material will be described below. (1) A mixed dispersion of cationic and anionic polymer particles is prepared. (2) The mixed dispersion of polymer particles is thinned with an asymmetric porous material.
Fill the porous layer . (3) Chemical fixing between the polymer particles and between the polymer particles and the porous body of the pore layer with a linking crosslinking agent such as glutaraldehyde. For the method of linking crosslinking, it is preferable to mix the linking crosslinking agent in the polymer dispersion and contact it with an acid or alkali atmosphere for crosslinking or to carry out crosslinking by heat treatment or the like. May go. (4) Wash with water. (5) Perform ionic group introduction treatment.

As described above, the cationic polymer particles and the anionic polymer particles are filled in the porous layer of the asymmetric porous body , and the space between the polymer particles and preferably between the polymer particles and the porous body of the porous layer are also increased. Since the connection between the polymer particles becomes dense due to the connection, the pressure resistance of the obtained membrane is improved, and not only dialysis by the concentration difference at the time of its use, but also dialysis by pressure and a mosaic charged membrane having a large area. Can also be prepared. Although the mosaic charged membrane using the polymer previously prepared as a spherical polymer has been described above, the mosaic charged membrane can be prepared in the same manner as described above even using a dispersion in which the polymer is dispersed in an appropriate poor solvent. Can be done.

The desalination apparatus of the present invention, a Turkey use the mosaic charged membrane of the present invention described above as a dialysis membrane is characterized, the structure of the apparatus is not particularly limited. FIG. 4 shows an example.
Shown in In this apparatus, dialysis can be performed under pressure, and a tank 7 for containing a dialysis solution is a pressure-resistant tank. And is attached to the tank 7. The mosaic charged film body 11 is supported by a filter backup 12 so as to withstand the applied pressure, and is hermetically attached to the tank 7 by a packing 10 at the flange bottom 9 of the tank 7. Depending on the pressure during dialysis,
Alternatively, when the mosaic charged film body is formed using a pressure-resistant asymmetric porous body, the filter backup 12 may be omitted. Dialysis is performed at an optimum pressure according to the performance of the mosaic charged membrane, the type of dialysate, and the like. The pressure in the tank is indicated by a pressure gauge 13. N-
The valves 1 to 3 also serve as a valve for reducing the pressure of the tank, a valve for injecting the dialysate, and a valve for increasing the pressure. This apparatus is supported by a ring mount 16 fixed to a mount shaft 15 by a clamp 14.

[0019]

Next, the present invention will be described more specifically with reference to examples. The parts and percentages in the text are based on weight. Reference Example 1 (Preparation of spherical crosslinked 4-vinylpyridine polymer) 10 parts of 4-vinylpyridine, 1 part of divinylbenzene, and 0.2 parts of 2,2'-azobis (2-amidinopropane) dihydrochloride ( V-50) (manufactured by Wako Pure Chemical Industries, Ltd.) and 500 parts of deionized water were charged into a flask, and polymerized at 80 ° C. for 8 hours under a nitrogen gas stream to obtain an emulsion. This was dialyzed and purified in deionized water using a dialysis membrane made of cellulose. As a result of observing this with a scanning electron microscope, it was a homogeneous spherical polymer having an average particle diameter of 200 nm.

Reference Example 2 (Preparation of spherical uncrosslinked 4-vinylpyridine polymer) Polymerization was carried out in the same manner as in Reference Example 1 except that divinylbenzene was not used, to obtain a homogeneous spherical polymer having an average particle diameter of 300 nm.

Reference Example 3 (Preparation of spherical crosslinked 4-vinylpyridine-based polymer) 10 parts of 4-vinylpyridine, 1 part of acrylamide,
1 part of divinylbenzene, 0.2 part of 2,2'-azobis (2-amidinopropane) diacetate and 500 parts of deionized water were charged into a flask, and charged under a stream of nitrogen gas.
Polymerization was carried out at 0 ° C. for 8 hours to obtain a homogeneous spherical polymer having an average particle size of 250 nm.

Reference Example 4 (Preparation of Spherical Crosslinked Sodium Styrene Sulfonate Polymer) 10 parts of sodium styrenesulfonate, 3.5 parts of acrylamide, 1.5 parts of methylenebisacrylamide,
0.15 parts of 2,2'-azobis (2-amidinopropane) dihydrochloride and 484 parts of water were charged into a flask, and polymerized at 70 ° C. for 8 hours under a nitrogen stream. Acetone was added to the polymerization solution to precipitate a polymer. The average particle size of the obtained polymer was 100 nm as measured by a scanning electron microscope.

Reference Example 5 (Preparation of Spherical Crosslinked Sodium Styrene Sulfonate Polymer) 10 parts of sodium styrenesulfonate, 8 parts of acrylamide, 2 parts of methylenebisacrylamide, 0.4 part of 2,2'-azobisiso Butyrylonitrile and 380 parts of methanol were charged into a flask, and 55 ° C. under a nitrogen stream.
For 7 hours, and the precipitated polymer was filtered. The average particle size of the obtained polymer was 1.1 μm as measured by a scanning electron microscope.

Reference Example 6 (Preparation of Spherical Cross-Linked Sodium Styrene Sulfonate Polymer) Polymerization was carried out in the same manner as in Reference Example 4 except that N-methylolacrylamide was used instead of acrylamide, to obtain a spherical polymer having an average particle diameter of 110 nm. .

Example 1 The spherical crosslinked poly4-vinylpyridine obtained in Reference Example 1 was used in 0.1%.
3. 1% water / acetone (1 / 2.5: weight ratio) dispersion
5 parts and 9 parts of a 0.15% water / acetone (1 / 2.5: weight ratio) dispersion of the spherical crosslinked sodium polystyrene sulfonate obtained in Reference Example 4 were stirred and mixed for 4 hours, and 40% chloroacetaldehyde was added. An aqueous solution (0.01 part) was added, and the mixture was further stirred and mixed for 2 hours. This polymer particle mixed dispersion was previously treated with a 5% aqueous solution of ethylene thioglycol to introduce a hydrophilic group into a disk-shaped stainless steel asymmetric porous body having a diameter of 4 cm (an average pore diameter of the pore layer was 0.3 μm, (Average pore diameter: 100 μm).

Next, in order to chemically fix between the polymer particles and between the polymer particles and the stainless steel porous body, first, the stainless steel porous body filled with the polymer particles is allowed to stand in a glutaraldehyde atmosphere for 8 hours. The mixture was allowed to stand in a hydrogen gas atmosphere for 5 hours to link and crosslink between the polymer particles and between the polymer particles and the porous body. Thereafter, the resultant was placed in an ammonia gas atmosphere for 2 hours, and further thoroughly washed with water to remove ammonium chloride. Finally, the polymer was placed in a methyl iodide atmosphere to quaternize the pyridinium group of the polymer, washed with water and dried to obtain a mosaic charged membrane of the present invention.

The evaluation method and the mosaic-charged membrane obtained as a result of the evaluation were applied to the dialysis apparatus (membrane area 1) shown in FIG.
2 cm ² ) to evaluate the dialysis performance based on the concentration difference of the membrane. 100 ml of an aqueous 0.1 mol / l potassium chloride solution as an electrolyte and 0.1 m as a non-electrolyte in a container 1
ol / l of an aqueous glucose solution (100 ml),
Was charged with 200 ml of pure water and dialyzed at 25 ° C. under normal pressure. When the dialysis time and the amount of dialyzed potassium chloride and glucose to the container 2 were measured, sufficient dialysis performance was shown.
The results obtained are shown in FIG. In addition, the equilibrium state of both vessels
(0.025 mol / l) was taken as 100% transmittance. Further, the mosaic charged membrane was placed in the pressure dialysis apparatus shown in FIG. 4 to evaluate the pressure dialysis performance. Using potassium chloride and glucose as in the dialysis evaluation based on the concentration difference,
The solution was pressurized at a pressure of g / cm ² and the concentration of potassium chloride and glucose in the dialysate was measured.

Example 2 90 parts of a 0.1% water / acetone (1/2: weight ratio) dispersion of the spherical uncrosslinked poly (4-vinylpyridine) obtained in Reference Example 2 and the spherical crosslinkage obtained in Reference Example 4 180 parts of a 0.15% water / acetone (1/2: weight ratio) dispersion of sodium polystyrene sulfonate was stirred and mixed for 4 hours, and 0.23 parts of a 40% aqueous chloroacetaldehyde solution was further added and mixed well.
This mixed dispersion of polymer particles was filled in a tubular ceramic asymmetric porous body having a diameter of 10 mm (average pore diameter of the pore layer: 0.5 μm, average pore diameter of the support layer: 100 μm, pore area: 200 cm ² ). Thereafter, a mosaic charged film body of the present invention was obtained in the same manner as in Example 1. When the obtained mosaic charged membrane was evaluated in the same manner as in Example 1, excellent dialysis performance and pressure dialysis performance were obtained as in Example 1.

Example 3 0.1 g of the spherical crosslinked poly4-vinylpyridine obtained in Reference Example 3.
25 parts of a 1% water / acetone (1/2: weight ratio) dispersion and 0.15% water / acetone (1/2: weight ratio) dispersion of the spherical crosslinked sodium polystyrene sulfonate obtained in Reference Example 6. 12.4 parts of the liquid was stirred and mixed. This mixed dispersion of polymer particles was filled in a disk-shaped asymmetric porous body made of glass having a diameter of 10 cm (average pore diameter of the pore layer: 0.5 μm, average pore diameter of the support layer: 100 μm). Next, a heat treatment was performed at 150 ° C. for 5 hours to link and crosslink the polymer particles to obtain a mosaic charged membrane of the present invention. When the obtained mosaic charged membrane was evaluated in the same manner as in Example 1, excellent dialysis performance and pressure dialysis performance were obtained as in Example 1.

[0030]

According to the present invention as described above, the pressure resistance and the mechanical strength are improved by filling the asymmetric porous body with the cationic polymer and the anionic polymer in a dialyzable manner. A large-area mosaic-charged membrane capable of separating a non-electrolyte or desalting a salt solution can be provided by a simple process.

[0031]

[Brief description of the drawings]

FIG. 1 is a schematic view of an asymmetric porous body.

FIG. 2 is a diagram illustrating a dialysis test device used in an example.

FIG. 3 is a view showing the results of a dialysis test of Example 1.

FIG. 4 is a diagram illustrating a pressure dialysis device used in an example.

[Explanation of symbols]

1: Container 2: Container 3: Mosaic charged film 4: Magnetic stirrer 5: Motor for stirring 6: Mechanical seal 7: 250 ml pressure tank 8: Stirring shaft 9: Flange bottom 10: Packing 11: Mosaic charged film 12: Mosaic charged membrane backup (filter backup) 13: pressure gauge 14: clamp 15: gantry shaft 16: ring gantry N1-3: solution injection nozzle, nozzle for pressure reducing valve and nozzle for pressure valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B01D 71/40 B01D 71/40 (72) Inventor Toku Mizoguchi 1-7-6 Nihonbashi Bakurocho, Chuo-ku, Tokyo Dainichisei Chemical Co., Ltd. Inside the company (72) Inventor Michie Nakamura 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo Inside Dainippon Seika Kogyo Co., Ltd. (72) Inventor Hitoshi Takeuchi 1-7-6 Nihonbashi Bakurocho, Chuo-ku, Tokyo Dainisei (72) Inventor Naomi Oguma 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo Dainichi Seika Kogyo Co., Ltd. (72) Inventor Norihisa Maruyama 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo (72) Inventor Shojiro Horiguchi Inventor 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (56) Reference Patent flat 5-84430 (JP, A) JP flat 6-262047 (JP, A) JP flat 5-7745 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) B01D 61/00-71/82 510

Claims (6)

(57) [Claims] 1. A composition comprising a cationic polymer, an anionic polymer and a support, wherein the support comprises a porous layer and a support layer.
Asymmetry a porous body, a mosaic charged membrane body characterized in that both polymers are dialyzable filled into the pores layer becomes. 2. A mosaic charged membrane material according to claim 1, wherein the average pore diameter of the pores layer is 10μm or less. 3. The mosaic charged membrane according to claim 1, wherein the cationic polymer and the anionic polymer are spherical polymers having an average particle diameter in a range from 0.01 μm to 10 μm. 4. The method according to claim 1, wherein both the polymer in the dispersion containing the cationic polymer and the anionic polymer are mixed with the pore layer and the support layer.
A method for producing a mosaic charged membrane, characterized in that the pore layer of an asymmetric porous body comprising: 5. A desalination method, comprising using the mosaic charged membrane according to claim 1 when separating an electrolyte from an aqueous salt solution containing an electrolyte and a non-electrolyte. 6. An apparatus for separating an electrolyte from an aqueous solution containing an electrolyte and a non-electrolyte by a dialysis membrane, wherein the dialysis membrane is the mosaic charged membrane according to claim 1.