JPS63218208A - Composite semipermeable membrane and its production - Google Patents

Abstract

PURPOSE:To obtain the titled membrane having high desalting and water- penetrating properties, by bringing to an interfacial polycondensation of an aromatic amine contg. more than a prescribed number of amino groups in a molecule and an alicyclic acid halogenide contg. more than a prescribed number of halogenated carbonyl groups in a molecule. CONSTITUTION:A fiber reinforced polysulfone supporting membrane is dipped in an aqueous solution mixed the another aromatic amine such as methaphenylene diamine, etc., with the polyfunctional aromatic amine contg. >=3 amino groups in one molecule, such as 1,3,5-triaminobenzene, etc. The surface of the obtd. membrane is coated with a trichlorofluoroethane solution of the alicyclic halogenide contg. >=2 halogenated carbonyl groups in one molecule such as 1,3,5-cyclohexane tricaboxylic chloride, etc., after draining said aqueous solution from the obtd. membrane. And, then, the obtd. film is washed an alkaline aqueous solution, such as sodium carbonate, etc., thereby obtaining the titled membrane coated with the hyper-thin membrane layer of polyamide on the supporting membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a composite semipermeable membrane useful for selective separation of liquid mixtures, particularly for desalination of canned water and seawater, and a method for producing the same.

[Prior Art] A composite semipermeable membrane is made by coating a microporous support membrane with an ultra-thin film layer made of polyamide produced by an interfacial polycondensation reaction between a polyfunctional aromatic amine and a polyfunctional acid halide. It is attracting attention as a reverse osmosis membrane with high performance and selective separation. For example, JP-A-55-147106 has been known as an interfacial polycondensation reaction between a polyfunctional aromatic amine and a polyfunctional aromatic acid halide; For example, JP-A-61-42302 has been known as a method for carrying out an interfacial polycondensation reaction between an amine and a trifunctional alicyclic acid halide.

[Problems to be solved by the invention] However, these membranes do not have the high permeability f1, high selective separation, heat resistance, etc. required for practical reverse osmosis membranes.
It did not fully satisfy conditions such as chemical resistance and 122 element resistance.

The present invention aims to improve these membrane performances and achieve high desalination in '44I↑
(1. One object of the present invention is to provide a method for manufacturing a composite semipermeable membrane having high water permeability.

[Means to solve the problem] In order to achieve the above object, the present invention has the following configuration.

J Nawamo, the present invention provides a method of forming a membrane by coating a microporous support membrane with an ultra-thin film layer made of polyamide produced by interfacial polycondensation of 1-(1> polyfunctional aromatic amine and polyfunctional acid halide). The composite Nido permeable membrane contains an aromatic amine having three or more amino acids in one molecule as a polyfunctional aromatic amine component, and contains two or more aromatic amines in one molecule as a polyfunctional acid halide component. 1. A composite semipermeable membrane comprising an alicyclic acid halide having a halogenated carbonyl group.

(2) In a method of obtaining a composite semipermeable membrane by interfacial polycondensation, an aqueous solution containing a trifunctional or higher-functional aromatic amine is applied onto a microporous support membrane, and then a bifunctional aromatic amine is applied onto the membrane. A method for producing a composite semipermeable membrane, which comprises forming an ultra-thin film by coating a water-immiscible organic solvent solution containing the above alicyclic acid halide. ” regarding.

The composite semipermeable membrane of the present invention is comprised of an ultra-thin film layer having substantially separation performance coated on a microporous support membrane having substantially no separation performance, and the ultra-thin film layer having a polyfunctional It consists of a crosslinked polyamide obtained by interfacial polycondensation of an aromatic amine and a polyfunctional acid halide.

A polyfunctional aromatic amine is an aromatic amine having two or more amino groups in one molecule, and the present invention uses an aromatic amine having three or more amino groups in one molecule as this polyfunctional aromatic amine. It is characterized by containing an amine. As the trifunctional or higher functional amine, for example, 1,3,5-triaminobenzene can be used. The above trifunctional or higher functional aromatic amine can be used alone, but may also be used as a mixture with other aromatic amines. In this case, any amine can be selected as the amine to be mixed, but it is preferable to avoid mixing m-71 nylene diamine, as this will improve both the salt removal rate and water permeability, giving good membrane performance.

A polyfunctional acid halide is a halogen having two or more halogens, and provides a polyamide through an interfacial polycondensation reaction with the above-mentioned polyfunctional aromatic amine. It is characterized by containing an alicyclic acid dove monogenide having the above halogenated carbonyl group. As the polyfunctional alicyclic acid halide, for example, 1,3.5-Schiff[l-power 1-nantricarboxylic acid, 1
, 3-cyclohekylenedicarboxylic acid, 1,4-cyclohekylenedicarboxylic acid, and the like can be used.

These acid halides can be used alone or as a mixture with other alicyclic or aromatic acid halides. Examples of the aromatic acid halides to be mixed include acid halides such as 1°3.5-benzene I-ricarboxylic acid, prephthalic acid, and inphthalic acid.

In consideration of reactivity with polyfunctional aromatic amines, the polyfunctional acid halide is preferably a polyfunctional acid chloride.

In the present invention, a preferred example of a microporous support membrane is a polysulfone support membrane reinforced with a fabric whose main component is at least one selected from polyester and aromatic polyamide.

A microporous support membrane is a layer that does not substantially have separation performance, and is used to give strength to an ultra-thin film layer that does have separation performance. The other side has fine pores that gradually become larger, and the size of the fine pores is 1010 mm on one side.
A support membrane having a structure as below is preferable. The above-mentioned microporous support membrane can be selected from various commercially available materials such as "Millipore Filter-VSWP" (trade name) manufactured by Millibore and "Ultra Filter UK10" (trade name) manufactured by Toyo Roshi Co., Ltd. , usually “Office Δ
Bu Zeileen Tsu A-ter Lilyge and Iberotsubmen 1~ Progress Report tt Nα
359 (1968). Pomopolymers or blends such as polysulfone, cellulose acetate, cellulose nitrate, and polyvinyl chloride are usually used as materials, but polysulfone, which has high chemical, mechanical, and thermal stability, is used. is preferred. Furthermore, it is preferable to use a polysulfone consisting of medium repeating [A] whose pore diameter is easy to control and has high dimensional stability, for example,
The above solution of polysulfone in dimebylformamide (DMr) is cast to a certain thickness on a tightly woven polyester cloth or non-woven fabric, and then it is poured into an aqueous solution containing 0.5% of sodium dodecyl sulfate and % of DMF. By performing wet coagulation in a microporous support film, a microporous support film is obtained in which most of the surface has fine pores with a diameter of several tens of pores or less.

Next, a method for manufacturing the present composite semipermeable membrane will be explained.

The ultra-thin membrane layer with substantial separation performance in the composite semipermeable membrane is
It is formed by interfacial integration using an aqueous solution containing the aforementioned polyfunctional aromatic amine and a water-immiscible organic solvent solution containing the aforementioned polyfunctional acid halide.

The concentration of the amino compound in the polyfunctional aromatic amine aqueous solution is 0.1 to 10% by weight, preferably 0.5 to 5.0% by weight, and the aqueous solution contains a reaction mixture between the amino compound and the polyfunctional acid halide. A surfactant, a fi solvent, an antioxidant IL agent, etc. may be included, as long as they do not interfere with C.

The aqueous amine solution may be coated on the surface of the microporous support membrane as long as the aqueous solution is coated uniformly and continuously on the surface, and can be coated using known coating methods, such as coating the surface of the microporous support membrane with the aqueous solution. The microporous support membrane may be immersed in the aqueous solution.

Next, the excessively applied amine aqueous solution is removed by a draining step. As a method for draining the liquid, for example, there is a method of holding the membrane surface vertically and allowing it to flow down by gravity. All of the water in the aqueous solution may be removed by draining and drying the membrane surface, but this is not always necessary.

Next, an organic solvent solution of the polyfunctional acid halide described above is applied, and a crosslinked polyamide ultra-λ9 film layer is formed by interfacial integration.

The polyfunctional acid compound in the solution is usually 0.01 to 1
It is more preferable to use 0% by weight, preferably 0.02 to 2% by weight dissolved in a solvent, and to contain an acylation catalyst such as DMF in the solution, since interfacial integration is promoted.

The core solvent must be immiscible with water, dissolve acid halides and not destroy the microporous support membrane, and be inert to amino compounds and acid halides. It can be any of the following. Preferred examples include hydrocarbon compounds, tric[10 trifluoroethane, etc., and n-hexano and trichlorotrifluoroethane are preferred from the viewpoint of reaction rate and solvent volatility. Considering the safety issue of flammability, it is more preferable to use trichlorotrifluoroethane.

The method for contacting the aqueous solution phase of the amino compound with the polyfunctional acid C[1] is carried out in the same manner as the method for coating the microporous support membrane with the aqueous solution of the amino compound, followed by washing with an aqueous alkaline solution such as sodium carbonate. .

Although the composite semipermeable membrane obtained in this way exhibits sufficiently good membrane performance even in c), it is difficult to
By immersing the membrane in a chlorine-containing aqueous solution of -16 to 13, membrane performance, especially desalination rate and water permeability, can be dramatically improved. Chlorine generating reagents include chlorine gas, salami powder,
Representative examples include sodium hypochlorite, chlorine dioxide, chloramine B1, chloramine T1, halazone, dichlorodimebruhydantoin, chlorinated isocyanuric acid and its salts, and it is preferable to determine the temperature depending on the strength of oxidizing power. . Among the above-mentioned chlorine generating reagents, a C1 mono-lithium hypochlorite aqueous solution is preferred from the viewpoint of ease of handling. There is an important relationship between the oxidizing power of a chlorine-containing aqueous solution and p(-1, and if pl-1 is lower than 6, it is sufficient/3
Both of these are unsuitable because they do not show oxidized horns, and when pl-113 is exceeded, hydrolysis of the amide bond occurs and the membrane layer suffers 1t-1 damage.

Therefore, I) I-16 to 13 are preferably immersed in a chlorine-containing aqueous solution.

[Examples] The present invention is not limited in any way by the following Examples (which will be described in more detail).

In addition, in the Examples, the JJI division ratio was determined by the following formula.

Solute Concentration in Membrane Permeate Removal Kilometers] = (1--) X 100 Solute Concentration in Membrane Feed Solution The fiber-reinforced polysulfone support membrane used in J3 in the present invention was manufactured by the following method.

Taffeta (multifilament yarn of 150 denier for both warp and weft, weave density: 90 pieces/inch vertically, 67 pieces/inch horizontally, thickness 160μ) made of polyester fibers of 30 bags/20 cuts is placed on a glass plate. A 15% by weight solution of polysulfone (Udel-P3500 manufactured by Union Carbide Co., Ltd.) in dimethylformamide (DMF) was applied to the -F to a thickness of 200μ at room temperature (20°C), and then tatara was applied. A fiber-reinforced polysulfone support membrane (hereinafter referred to as FR-PS support membrane) is prepared by immersing it in pure water and leaving it for 5 minutes.
215μ) is the pure water permeability coefficient of pressure IKg/d1 temperature 2
0.005-0.01g/cd-3eC measured at 5℃
・It was atIll.

Examples 1-2 FR-PS support membrane with 1,3,5-triaminobenzene 0
．． It was immersed for 1 minute in an aqueous solution having 5!1 ffi% and 1.45 weight id% of metaphenylenediamine. After slowly pulling up the support membrane in the vertical direction and removing excess aqueous solution from the surface of the support membrane, a polyfunctional acid chloride having the composition shown in Table 1 and trichlorotrifluoroethane containing 300 ppm of DMF were added. The solution was applied so that the surface was completely wetted and allowed to stand for 11 minutes. Next, add the membrane! After draining and removing excess solution, the sample was immersed in a 1% aqueous solution of sodium carbonate for 5 minutes.

The composite semipermeable membrane thus obtained was pI-16.

The 1500r) 9m saline solution prepared in step 5 was used as jλ water, and
As a result of reverse osmosis testing under the conditions of J Ky /'cm and 25°C, the membrane performance shown in Table 1 was obtained.

Examples 3-8 An IR-113 support membrane was immersed in an aqueous Mino solution having the composition shown in Table 1 for 1 minute. The support membrane is hung 1"11j
After removing excess aqueous solution from the surface of the support membrane, the polyfunctional M chloride and DM having the compositions shown in Table 1 were removed.
The surface can be completely covered with the trichloro CI trinorolo] L tan solution containing 300 ppm of F.
It was then left to stand for 1 minute. Next, hold the llu vertically, remove excess solution with a drainer, and add 0.2
It was immersed in a wt% aqueous solution for 5 minutes.

Roughly, the membrane was immersed for 2 minutes in an aqueous solution of pLl 7 containing 600 ppm of sodium hypochlorite and 0.2% by volume of monopotassium phosphate, and then washed with tap water. Go ,.

The composite semipermeable membrane thus obtained was pif 6.

1500Dpmft salt water adjusted to 5 is used as raw water,
As a result of the reverse osmosis test under the conditions of KU/ctA and 25°C, the membrane performance shown in Table 1 was obtained.

In addition, the abbreviations in Table 1 are as follows.

TAB: L3,5-1~riaminobenzene m-PDA
: metaphenylenediamine Cr C: L3,5-Schiff[1 hexane tricarboxylic acid chloride CDC: 1,4-cyclohexanedicarboxylic acid chloride 1 M C: 1,3,5-benpine 1 hescarboxylic acid chloride (Trimesic acid chloride) TPC: Terephthalic acid chloride Water permeability is the permeation amount per day per 1 square meter of membrane area (~
"L direction mail)" was shown.

Table 1 [Effects of the Invention] According to the present invention, it is possible to provide a composite semipermeable membrane having high desalting properties and high water permeability, and a method for producing the same.

Claims (7)

[Claims] (1) In a composite semipermeable membrane formed by coating a microporous support membrane with an ultra-thin layer of polyamide obtained by interfacial polycondensation of a polyfunctional aromatic amine and a polyfunctional acid halide, Alicyclic acid halogen containing an aromatic amine having three or more amino groups in one molecule as an amine component and having two or more halogenated carbonyl groups in one molecule as a polyfunctional acid halide component A composite semipermeable membrane characterized by containing a compound. (2) The composite semipermeable membrane according to claim (1), wherein the polyfunctional aromatic amine having three or more amino groups is 1,3,5-triaminobenzene. (3) The composite semipermeable membrane according to claim (1), wherein the polyfunctional acid halide is a polyfunctional acid chloride. (4) The alicyclic acid halide having two or more halogenated carbonyl groups is 1,3,5-cyclohexanetricarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1
, 4-cyclohexanedicarboxylic acid, and at least one selected from acid halides of 4-cyclohexanedicarboxylic acid. (5) The composite semipermeable membrane according to claim (1), wherein the microporous support membrane is made of polysulfone. (6) The composite half-layer according to claim (1), wherein the microporous support membrane is reinforced with a fabric whose main component is at least one selected from polyester and aromatic polyamide. Permeable membrane. (7) In a method for obtaining a composite semipermeable membrane by interfacial polycondensation, an aqueous solution containing an aromatic amine having three or more functional groups is coated on a microporous support membrane, and then an aqueous solution containing an aromatic amine having three or more functional groups is applied onto the membrane. A method for producing a composite semipermeable membrane, comprising forming an ultra-thin film by applying a water-immiscible organic solvent solution containing an alicyclic acid halide.