JPH0278428A - Laminated semipermeable membrane and production thereof - Google Patents

Abstract

PURPOSE:To selectively remove a pollutant or an effective substance by coating a microporous support membrane with a very thin membrane based on piperazine polyamide and ethylenediamine polyamide polycondensed with a bifunctional acid halide. CONSTITUTION:An aq. soln. contg. 0.2-1.0wt.%, in total, of piperazine and ethylenediamine in >=1.0 molar ratio of ethylenediamine to piperazine is prepd. and a compd. represented by formula I (where each of A and A' is a benzene or naphthalene ring and X is -O- or -CH2-) is added to the soln. by 0.01-1.0wt.%. The resulting soln. is applied to a microporous support membrane, a multifunctional acid halide soln. is further applied and a cross linked polymer layer is formed as an active layer by polycondensation to produce a laminated semipermeable membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite semipermeable membrane for selectively permeating components of a liquid mixture and a method for manufacturing the same.

In particular, production of ultrapure water used in semiconductor manufacturing, desalination of water, selective removal or recovery of pollutants or effective substances from dyeing wastewater, electrocoating paint wastewater, etc., and closed wastewater drainage. It is possible to contribute to such things.

[Prior art]

Various composite membranes have been studied in the past, but recently piperazine-based membranes have been proposed and attracted attention as chlorine-resistant membranes (for example, Japanese Patent Publication No. 56-500062, U.S. Patent No. 4,259). .183 Specification, PB Report 8
0-127574, PB Report 288387). However, although this membrane has a high water flow rate at low pressure, the rejection rate of common salt (sodium chloride) is low at around 50%, which poses practical problems in desalination processes, especially when using ultrapure water used in semiconductor manufacturing. There was a problem in the ability to remove organic components due to this low rejection rate when used in the production of.

Furthermore, an ethylenediamine-based film has also been proposed as a film having chlorine resistance, but for example, JP-A-58-24303
No. 1, JP-A-59-26101, JP-A-59-
Publication No. 179103, PB Report 83-243170
), although this membrane has high desalination properties, it has poor water permeability and has the problem of requiring high operating pressure to obtain a certain amount of water flow.

[Problem to be solved by the invention]

The present invention aims to solve the above-mentioned drawbacks of the prior art, and provides a composite semipermeable membrane having high desalinization properties and a high water flow rate under low operating pressure, and a method for manufacturing the same. The purpose is to provide a method.

[Means to solve the problem]

In order to achieve the above object, the present invention consists of the following configuration.

"<1) A composite semipermeable membrane consisting of a microporous support membrane and an ultra-thin membrane covering the support membrane, wherein the ultra-thin membrane is mainly composed of piperazine polyamide and ethylenediamine polyamide polycondensed with a bifunctional acid halide, and , the molar ratio of the structural units of ethylenediamine polyamide to the structural units of piperazine polyamide is 1.0 or more, and the amount of water produced at an operating pressure of 10 kg/d is 0.0.
8Tn3/Tr12・day or more, 1.5m3/m'・
Below the diary, the salt elimination rate of 0.05% by weight saline solution is 90%.
As described above, a composite semipermeable membrane is characterized in that it exhibits a performance of 99% or less.

(2) A composite semipermeable membrane consisting of a microporous support membrane and an ultra-thin membrane covering the support membrane, wherein the ultra-thin membrane is mainly composed of piperazine polyamide and ethylenediamine polyamide polycondensed with a difunctional acid halide, and The molar ratio of the structural units of ethylenediamine polyamide to the structural units of piperazine polyamide is 0.25
In addition, the amount of water supplied at an operating pressure of 10 kg/- is 0.8 T.
A composite semipermeable material characterized by exhibiting a salt rejection rate of 90% or more and 99% or less for r13/Tr12-days or more and 1,5 m3/m2-days or less, and 0.05% by weight saline solution. film.

(3) A composite in which a microporous support membrane is coated with an aqueous solution containing piperazine and ethylenediamine, and then a polyfunctional acid halide solution is applied to cause a polycondensation reaction to form a crosslinked polymer that will become the active layer. In the semipermeable membrane manufacturing process, 0.01% of the compound represented by the following formula (I) is added to the aqueous solution.
% by weight or more and 1.0% by weight or less, and the total concentration of piperazine and ethylenediamine is 0.2% by weight in the aqueous solution.
% by weight or more and 1.0% by weight or less, and further characterized in that the molar ratio of ethylenediamine to piperazine is 1.0 or more.

(In the formula, A and A- represent a benzene ring or a naphthalene ring. X represents -0- or -CHp-.) (4) Apply an aqueous solution containing piperazine and ethylenediamine to the microporous support membrane Then, in the manufacturing process of a composite semipermeable membrane in which a polyfunctional acid halide solution is applied to cause a polycondensation reaction to form a crosslinked polymer that will become an active layer, a compound represented by the following formula (I>) is added to the aqueous solution. 0.01 of the compound
% by weight or more and 1.0% by weight or less, and the total concentration of piperazine and ethylenediamine is 1.0% by weight or more in the aqueous solution.
A method for producing a composite semipermeable membrane, characterized in that the molar ratio of ethylenediamine to piperazine is 0.01% or more and 0.25 or less.

(In the formula, A and A- represent a benzene ring or a naphthalene ring. X represents -〇- or -CH2-.) The main components are piperazine polyamide and ethylenediamine polyamide.The term "main component" means that the total weight of both polyamides accounts for 50% or more of the total weight of the ultra-thin film. The following formula (If), (II
The structural unit represented by I) is used as a repeating unit.

In the present invention, it is necessary that the molar ratio of the structural units of the ethylenediamine polyamide to the structural units of the piperazine polyamide is 1.0 or more, or 0.25 or less. Further, in order to increase the strength and insolubility of the ultra-thin film, it is preferable to include a crosslinked polyamide using a trifunctional or higher functional acid halide.

In the present invention, the microporous support membrane is a layer that does not substantially have separation performance, and is used to impart strength to an ultra-thin film layer (active layer) that substantially has separation performance, Preferably, the support film has a structure in which it has uniform fine pores or gradually larger fine pores from one side to the other, and the size of the fine pores is 100 nm or less on one side. The above-mentioned microporous support membranes include "Millipore Filter-VSWP" (trade name) manufactured by Millipore Corporation and "Ultra Filter UKIO" (trade name) manufactured by Toyo Roshi Co., Ltd.
Although they can be selected from a variety of commercially available materials, such as Paoffice of Saline Water Research and Development Progress Report, No. 359 (1968), Homopolymers or blends of polysulfone, cellulose acetate, cellulose nitrate, polyvinyl chloride, etc. are usually used, but polysulfone, which has high chemical, mechanical, and thermal stability, is used as the material. It is preferable to use, for example, a solution of polysulfone in dimethylformamide (DMF) cast to a certain thickness onto a tightly woven polyester cloth or non-woven cloth, and then mixed with 0.5% by weight of sodium dodecyl sulfate and D.I.V.
By wet coagulation in an aqueous solution containing 2% by weight of IP, a microporous support membrane having most of its surface having fine pores with a diameter of several tens of nanometers or less can be obtained.

Next, the film forming method will be explained.

In the first step of membrane formation, the microporous support membrane is coated with an aqueous solution containing piperazine and ethylenediamine (hereinafter referred to as the composition). Examples include a method of soaking a sexual support membrane.

In the present invention, it is necessary to contain the compound represented by formula (I) in the composition in an amount of 0.01% by weight or more and 1.0% by weight or less.

(In the formula, A and A- represent a benzene ring or a naphthalene ring. X represents -0- or -CH2-.) This formula (
The compound of 1) may be cross-linked with -X- to form a dimer to a pentamer. The concentration of the compound represented by formula (I) is
If the content is more than 1.0% by weight in the composition, the active layer will peel off after film formation, and if it is less than 0.01% by weight, it will be difficult to develop high water permeability. Examples of the compound represented by formula (I>) include the following (R is a long-chain alkyl group) The alkyl group may be of any type, but from the viewpoint of coating properties of the composition, the number of carbon atoms It is preferably a long chain alkyl group of about 12 or so, and two or more types of alkyl groups may be mixed.

In addition, in the present invention, in order to make the molar ratio of the constituent units of ethylenediamine polyamide to the constituent units of piperazine polyamide in the composite semipermeable membrane obtained be 1.0 or more, two amines, piperazine and ethylenediamine, in the composition are required. (hereinafter abbreviated as amine concentration)
is 0.2% by weight or more and 1.0% by weight or less, and the molar ratio of ethylenediamine to piperazine is required to be 1.0% or more. Amine concentration is 1.0
If it exceeds 0.2% by weight, the water permeability becomes low.
If it is less than that, it will be difficult to apply it uniformly.

In addition, in order to set the molar ratio of the constituent units of ethylenediamine polyamide to the constituent units of piperazine polyamide in the resulting composite semipermeable membrane to be 0.01 or more and 0.25 or less, the concentration of the amine should be 1°0% by weight or more, 10% by weight
and the molar ratio of ethylenediamine to piperazine must be 0.01 or more and 0.25 or less.

If the amine concentration exceeds 10% by weight, the increase in effectiveness will be small and it will be disadvantageous in terms of cost, and if it is less than 1.0% by weight, it will be difficult to achieve a high salt removal rate with good reproducibility.

Furthermore, in the present invention, Na2C(b
, NaOH, Na3POa, etc. may be added, and this is effective as a scavenger for hydrochloric acid generated when the polymerization reaction for forming the active layer occurs.

After coating a microporous support membrane with a composition, a draining step is generally provided to remove excess composition.

Examples of methods for draining the liquid include a method of holding the membrane surface in a vertical direction and allowing it to flow down by gravity.

The microporous support membrane coated with the composition is then air-dried. As a method for this, for example, after removing the excess composition as described above, the film surface is continued to be held vertically and dried at room temperature. The degree of drying may be such that no liquid composition is observed on the microporous support membrane. Remaining liquid may cause defects in the active layer. Also,
Drying with hot air is also possible, but excessive drying may impair the reproducibility of membrane performance or reduce water permeability.

In the next step, a solution of a polyfunctional acid halide in an organic solvent immiscible with water is applied, and an interfacial polycondensation reaction between the amines and the polyfunctional acid halide is carried out in 5 situ.
A crosslinked polyamide as an active layer is formed, and then the excess solution of the polyfunctional acid halide in an organic solvent is removed by draining to obtain a composite semipermeable membrane.

In the present invention, the polyfunctional acid halide may be one that reacts with the amines to form a crosslinked polyamide that is an active layer, such as trimesic acid halide, benzophenone tetracarboxylic acid halide, trimethic acid halide, pyrometyl acid halide, etc. Examples include aromatic polyfunctional acid halides such as acid halide, isophthalic acid halide, terephthalic acid halide, naphthalene dicarboxylic acid halide, diphenyldicarboxylic acid halide, lysine dicarboxylic acid halide, benzenedisulfonic acid halide, and chlorosulfonylisophthalic acid halide. However, in consideration of the solubility in the membrane forming solvent and the performance of the composite semipermeable membrane, inphthalic acid chloride, terephthalic acid chloride, and a mixture of these and trimesic acid chloride are preferred.

The concentration of acid halide is not particularly limited, but if it is too low, the formation of the active layer made of crosslinked polyamide will be insufficient, which may be a drawback, and if it is too high, it is disadvantageous from a cost perspective, so 0.1 It is preferably about 0.5% by weight.

Further, the organic solvent may be any solvent as long as it is immiscible with water, dissolves the acid halide, and does not destroy the microporous support membrane. Preferred examples include hydrocarbon compounds, cyclohexane, trichlorotrifluoroethane, etc., but n-hexane or trichlorotrifluoroethane is preferred from the viewpoint of reaction rate and solvent volatility, and from the safety point of view of flammability. Considering the above problem, trichlorotrifluoroethane is more preferred.

Although the composite semipermeable membrane obtained as described above can be used as is, it is preferable to remove unreacted residues by washing with water or the like.

As described above, in the present invention, when forming a film by interfacial polycondensation of an aqueous solution containing piperazine and ethylenediamine and a polyfunctional acid halide solution, the compound represented by general formula (I) is added to the amine aqueous solution. containing, and
By limiting the concentrations of perazine and ethylenediamine in the aqueous amine solution and the molar ratio of ethylenediamine to piperazine, the operating pressure 10k(]/
- Composite with performance of salt rejection rate of 90% or more and 99% or less of 0.05 wt% saline water under 0.81 TIB/lT12・day, 1.5Trl”7m2・day A semipermeable membrane can be obtained.

〔Example〕

In the following examples, salt rejection, as selective separation power, was determined by conventional means by measuring electrical conductivity. The rejection rate of organic matter was measured using a differential refractometer or a TOC meter.

In addition, as permeation performance, water overrate (water flow rate) was determined by the amount of water permeation per unit area and unit time.

Reference Example 1 Taffeta made of polyester fibers with a length of 30 an inch and a width of 20 an inch (multifilament yarn of 150 denier for both warp and weft yarns, weaving density of 90 yarns/inch in the vertical direction, 67 yarns/inch in the horizontal direction, thickness 160 μm) was made of glass. It was fixed on a plate, and a 16% by weight dimethylformamide (DMF) solution of polysulfone (Udel-P3500 manufactured by Union Carbide Co., Ltd.) was added on top of the plate to a thickness of 200μ at room temperature (20°C).
A fiber-reinforced polysulfone support membrane (hereinafter abbreviated as FR-PS support membrane) is produced by casting in step C), immediately immersing it in pure water, and leaving it for 5 minutes. The pure water permeability coefficient of the FR-PS support membrane (thickness 210-215μ) thus obtained is 0.005-0.01g/aJ-sec − as measured at a pressure of 1hg/−1 and a temperature of 25°C. It was an ATM.

Example I A FR-PS supported membrane was prepared in an aqueous amine solution containing 0.2% piperazine, 0.2% ethylenediamine, 0.1% sodium dodecyl diphenyl ether disulfonate, and 0.2% trisodium phosphate. immersed in for 1 minute. The support membrane was slowly pulled up vertically to remove excess aqueous solution from the surface of the support membrane, and then air-dried for 5 minutes. Next, apply a trichlorotrifluoroethane solution containing 0.12% by weight of trimesic acid chloride and 0.18% by weight of isophthalic acid chloride so that the surface is completely wet, then hold the membrane vertically and drain the excess solution. After cutting and removing it, it was washed with distilled water.

The thus obtained composite semipermeable membrane was mixed with 500 ppm saline solution adjusted to pH 6.5 as raw water, and 10 kg/a
nt, reverse osmosis test was conducted under conditions of 25°C.

As a result, the desalination rate was 96.7%, and the water overrate was 0°90m3.
/Tn2·day performance.

Subsequently, the raw water was changed to 0.1% isopropyl alcohol aqueous solution, and a reverse osmosis test was conducted under the same conditions. As a result, an exclusion rate of 86% was shown.

Example 2 Example 1 except that an aqueous amine solution containing 0.4% by weight of piperazine, 0.4% by weight of ethylenediamine, 0.2% by weight of sodium dodecyl diphenyl ether disulfonate, and 0.4% by weight of trisodium phosphate was used. A membrane was formed in the same manner as above, and a reverse osmosis test was conducted. As a result, the salt removal rate was 97.
5% and water overrate of 0.80 m3/m2·day.

Example 3 Example 1 except that an aqueous amine solution containing 0.1% by weight of piperazine, 0.1% by weight of ethylenediamine, 0.05% by weight of sodium dodecyl diphenyl ether disulfonate, and 0.1% by weight of trisodium phosphate was used. A membrane was formed in the same manner as above, and a reverse osmosis test was performed. As a result, the desalination rate was 9
It showed performance of 4.9% and water overrate of 1.20Tr+1/m2・day.

Example 4 Piperazine 0.16% by weight, ethylenediamine 0.24%
Weight%, sodium dodecyl diphenyl ether disulfonate 0.2% by weight, trisodium phosphate 0.4% by weight
Aqueous amine solution with trimesic acid chloride 0.0
A membrane was formed in the same manner as in Example 1 using a trichlorotrifluoroethane solution containing 9% by weight and 0.21% by weight of isophthalic acid chloride, and a reverse osmosis test was conducted. As a result, the desalination rate was 95.2%, water overrate was 0, and 817ri”/
It showed a performance of m2·day.

Example 5 Aqueous amine solution with 0.2% by weight of piperazine, 0.2% by weight of ethylenediamine, 0.2% by weight of sodium dodecyl diphenyl ether disulfonate, 0.4% by weight of trisodium phosphate and 0.05% by weight of trimesic acid chloride. , using a trichlorotrifluoroethane solution containing 0.25% by weight of isophthalic acid chloride, Example 1
A membrane was formed in the same manner as above, and a reverse osmosis test was conducted. As a result, the desalination rate was 95.9%, and the water overrate was 0.83Tr11/Tr1.
It showed a performance of 2 days.

Comparative Example 1 Example 1 except that an amine aqueous solution containing 0.6% by weight of piperazine, 0.6% by weight of ethylenediamine, 0.4% by weight of sodium dodecyl diphenyl ether disulfonate, and 0.6% by weight of trisodium phosphate was used. A membrane was formed in the same manner as above, and a reverse osmosis test was conducted. As a result, the desalination rate was 95.7
%, indicate the performance of water overspeed 0, 60 m3/m2・day.

Comparative Example 2 A membrane was formed in the same manner as in Example 1, except that sodium dodecyl diphenyl ether disulfonate was not added, and a reverse osmosis test was conducted. As a result, the salt removal rate was 96.5%, and the water overrate was 0.13Tn3/Tr12·day.

Reference Example 2 Sodium hypochlorite was added to raw water under the same conditions as in Example 1 to adjust the residual chlorine to 10 ppm and p) to 46.5, and the membrane obtained in Example 1 was operated for 25 hours. Performance before and after adding chlorine: desalination rate 96.3% 96.9%, water overrate 0.92Tr+3/m''day 0, 86 m'/Tn
No deterioration occurred after 2 days. Add more chlorine,
When operated for 70 hours at 0 ppm, the desalination rate was 97.
．． 0%, water overspeed is 0, 86 Tri3/ln2・
day, and the chlorine resistance was good.

Reference example 3 Raw water was changed to 1.0% perperoxide ice water pH 6.5, Example 1
Using the membrane obtained at 3 kg/crt, 12
It was operated for 0 hours and a hydrogen peroxide resistance test was conducted. Evaluation pressure 10kg/(J, salt 500ppm, pH 6,5,25
The reverse osmosis performance before and after the hydrogen peroxide resistance aqueous test evaluated under the conditions of °C was 95.5% for the desalination rate of 96.0%, and the water velocity overrate of 0.89 m3/m2/day for 0 and 95 m3/m2, respectively.
・Showed good resistance to day and day.

Example 6 A composition having 2.0% by weight of piperazine, 0.2% by weight of ethylenediamine, 0.1% by weight of sodium dodecyl diphenyl ether disulfonate, and 1.0% by weight of trisodium phosphate was applied to a PR-PS support membrane for 1 minute. Coated. Stand the support membrane vertically, remove excess aqueous solution from the surface of the support membrane, and then dry at 70°C for 30 seconds. Next, a trichlorotrifluoroethane solution containing 0.12% by weight of trimesic acid chloride and 0.18% by weight of inphthalic acid chloride is applied so that the surface is completely wetted, and then the membrane is held vertically and the excess solution is removed. After cutting and removing it, it was washed with distilled water.

The composite semipermeable membrane thus obtained was mixed with 500 ppm saline solution adjusted to pH 6.5 as raw water, and 10 kg g10
A reverse osmosis test was conducted under the conditions of +t and 25°C.

As a result, the desalination rate was 96.0%, and the water velocity overrate was 0°8371.
The performance was 13/m2/day.

Subsequently, the raw water was changed to 0.1% inpropyl alcohol aqueous solution, and a reverse osmosis test was conducted under the same conditions. The result showed an exclusion rate of 56%.

Example 7 Ethylenediamine in the composition of Example 6 was 0.1% by weight.
A film was formed in the same manner as in Example 6 except for binding, and a reverse osmosis test was conducted. As a result, the desalination rate was 95.5%, the water velocity overrate was 1,
Show the performance of OOmff1/rn2・day.

Example 8' A film was formed in the same manner as in Example 6, except that sodium dodecyl diphenyl ether disulfonate in the composition of Example 60 was changed to methylene bis(sodium naphthalene sulfonate) shown in the following formula, and a reverse osmosis test was conducted. As a result, the desalination rate was 95.9%, and the water velocity overrate was 0.90Trlffi/Tr1.
Show the performance for 2 days.

Example 9 The composition of Example 6 was applied to an FR-PS support membrane for 1 minute. The support membrane was stood vertically, and after removing excess aqueous solution from the surface of the support membrane, it was dried at 80° C. for 30 seconds.

Next, apply a trichlorotrifluoroethane solution containing 0.24% by weight of trimesic acid chloride and 0.06% by weight of isophthalic acid chloride so that the surface is completely wet, then hold the membrane vertically and drain the excess solution. After cutting and removing it, it was washed with distilled water. As a result of the reverse osmosis test, the salt removal rate was 92.2%, and the water velocity overrate was 1.25Tr13/Tr12.
showed the performance of the day.

Comparative Example 3 A film was formed in the same manner as in Example 6, except that a composition containing 1.0% by weight of piperazine, 0.1% by weight of sodium dodecyl diphenyl ether disulfonate, and 1.0% by weight of trisodium phosphate was used. , conducted a reverse osmosis test. As a result, desalination rate was 66.0%, water velocity overrate was 1, and 57 m3.
/m2·day.

Comparative Example 4 Produced in the same manner as in Example 8 using a composition containing 2.0% by weight of piperazine, 1.2% by weight of ethylenediamine, 0.1% by weight of sodium dodecyl diphenyl ether disulfonate, and 1.0% by weight of trisodium phosphate. membrane and reverse osmosis test was performed. As a result, the salt removal rate was 96.0% and the water velocity overrate was 0.20TrI! /Tr12·day.

Reference Example 4 Under the same conditions as in Example 6, sodium hypochlorite was added to the raw water to adjust the residual chlorine to 10 ppm and the pH to 6.5, and the membrane obtained in Example 6 was operated for 30 hours. The performance before and after adding chlorine is as follows: desalination rate of 95.9% is 96.5%, water overrate is 0.86Tr13/Tr12・day is 0.80Trl/day
No deterioration occurred at Tr12·day, and the chlorine resistance was good.

Reference Example 5 Raw water was changed to 2.0% perperoxide ice water pH 6.5, Example 6
Using the membrane obtained in the above, the membrane was operated at 3 kg/ffl at 25° C. for 60 hours, and an aqueous peroxide resistance test was conducted. Evaluation pressure 10
kg/art, salt 500ppm, pH 6,5,25
The reverse osmosis performance before and after the hydrogen peroxide resistance test evaluated under the conditions of °C was 95.6% for desalination rate of 96°2%, water overspeed 0, and 0.92m for 85 m'/ynz□day, respectively. /
It shows good resistance with m2・day.

[Effects of the Invention] According to the present invention, even if the operating pressure is as low as 10 kg/-, the water supply amount at an operating pressure of 10 kg/ri is 0, 8 m3/m2-day or more, and 1.5 Tr+! /T
It is possible to provide a composite semipermeable membrane that can exhibit a salt rejection rate of 90% or more and 99% or less in 0.05 wt% saline under r12/day, and a method for producing the same.

Claims (3)

[Claims] (1) A composite semipermeable membrane consisting of a microporous support membrane and an ultra-thin membrane covering the support membrane, wherein the ultra-thin membrane is mainly composed of piperazine polyamide and ethylenediamine polyamide polycondensed with a difunctional acid halide, and The molar ratio of the structural units of ethylenediamine polyamide to the structural units of piperazine polyamide is 1.0 or more, and the amount of water produced at an operating pressure of 10 kg/cm^2 is 0.
．． 8m^3/m^2・day or more, 1.5m^3/m^2・
Within days, the salt elimination rate of 0.05% by weight saline is 90%
As described above, a composite semipermeable membrane is characterized in that it exhibits a performance of 99% or less. (2) A composite semipermeable membrane consisting of a microporous support membrane and an ultra-thin membrane covering the support membrane, wherein the ultra-thin membrane is mainly composed of piperazine polyamide and ethylenediamine polyamide polycondensed with a difunctional acid halide, and The molar ratio of the structural units of ethylenediamine polyamide to the structural units of piperazine polyamide is 0.01
above, 0.25 or less, and furthermore, the operating pressure is 10 kg/
The amount of water produced in cm^2 is 0.8 m^3/m^2・day or more and 1.5 m^3/m^2・day or less, the salt rejection rate of 0.05% by weight saline solution is 90% or more, A composite semipermeable membrane characterized by exhibiting a performance of 99% or less. (3) A microporous support membrane is coated with an aqueous solution containing piperazine and ethylenediamine, and then a polyfunctional acid halide solution is coated to cause a polycondensation reaction to form a crosslinked polymer that will become the active layer. In the manufacturing process of the permeable membrane, 0.0 of a compound represented by the following formula (I) is added to the aqueous solution.
1% by weight or more and 1.0% by weight or less, and the total concentration of piperazine and ethylenediamine is 0 in the aqueous solution.
．． 2% by weight or more and 1.0% by weight or less, and further characterized in that the molar ratio of ethylenediamine to piperazine is 1.0 or more. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, A and A' represent a benzene ring or a naphthalene ring. X represents -O- or -CH_2-.) (4)
A microporous support membrane is coated with an aqueous solution containing piperazine and ethylenediamine, and then a polyfunctional acid halide solution is coated to cause a polycondensation reaction to form a crosslinked polymer that will become the active layer. In the manufacturing process, 0.0 of a compound represented by the following formula (I) is added to the aqueous solution.
1% by weight or more and 1.0% by weight or less, and the total concentration of piperazine and ethylenediamine is 1% by weight or more in the aqueous solution.
．． 0% by weight or more and 10% by weight or less, and further characterized in that the molar ratio of ethylenediamine to piperazine is 0.01 or more and 0.25 or less. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, A and A' represent a benzene ring or a naphthalene ring. X represents -O- or -CH_2-.)