KR20000031689A - Process for the preparation of polyamide reverse osmosis composite film - Google Patents

Abstract

PURPOSE: A reverse osmosis film having a high flow rate and a good salt rejection rate is prepared by addition of polar compound to aqueous amine solution. CONSTITUTION: Multi-functional aqueous amine solution containing multi-functional amine and polar compound and organic solution containing amine reactive compound selected from multi-functional acyl halide, sulfonyl halide and isocyanate are reacted to give polyamide film, followed by forming on a porous supporting layer to give polyamide osmosis composite film. The polar compound is selected from dipropylene glycol monoalkyl ether, 1,3-propane diol alkyl substitutes, 1,2-alkane diol, diethylene glycol hexyl ether, diethylene glycol t-butyl methyl ether, triethylene glycol dimethyl ether, 1-x-cyclohexane dimethanol(x is 2-4), or alkoxy ethanol, propylene glycol and alkoxy ethanol, sulfoxide derivative and alkoxy ethanol, urea and alkoxy ethanol, diethylene glycol hexyl ether and propylene glycol, diethylene glycol hexyl ether and sulfoxide derivative, diethylene glycol hexyl ether and glycerol, 1,3-propane diol alkyl substitute and sulfoxide derivative, propylene glycol and propylene glycol monoalkyl ether.

Description

Polyamide Reverse Osmosis Composite Membrane Manufacturing Method

The present invention relates to a new reverse osmosis composite membrane manufacturing method used for desalination of low-salt and a lot of water, such as industrial water, agricultural water, household water, etc. through salt removal of water, such as semi-saline or sea water.

Dissociated materials can be separated from the solvent by membranes with selectivity such as microfiltration, ultrafiltration, reverse osmosis membranes. Desalination of semi-saline or seawater using a reverse osmosis membrane pressurizes dissolved ions or molecules from salted water to filter salts through the reverse osmosis membrane, allowing purified water to pass through the membrane while the dissolved ions or molecules do not pass through the membrane. Means that. At this time, the osmotic pressure acts as a reverse direction of the reverse osmosis process, and the higher the concentration of the feed water, the higher the osmotic pressure.

Reverse osmosis membranes should have certain characteristics in desalination of semi-saline or seawater with a large amount of water through salt removal. The membrane must be characterized by a salt removal constant. Indeed, the salt removal rate must be at least 97% for salt free water to be suitable for many commercial applications. Another requirement for reverse osmosis membranes is that they must have a high flow rate, ie, the relative amount of water passing through the membrane at a relatively low pressure. In general, the flow rate should be at least 10 gallons at 800 psi for seawater desalination and at least 15 gallons at 225 psi in desalination conditions. However, in special cases, the salt removal rate may be lower than the desired value for high flow rate.

As a reverse osmosis membrane, the composite membrane is composed of a porous support layer and a polyamide-based composite thin film on the support layer. Typical polyamide membranes can be obtained by interfacial polymerization of polyfunctional amines and polyfunctional acyl halides.

U.S. Patent 4,277,344, previously filed by Cadotte, discloses aromatic polyamides obtained by interfacial polymerization of aromatic polyfunctional amines containing two primary amine substituents and aromatic acyl halides having three or more acyl halide functional groups. Techniques for thin films have been proposed. In this case, the reverse osmosis membrane is prepared by coating m-phenylenediamine on a microporous polysulfone support, and then reacting an excess of metaphenylenediamine solution with dissolved trimezoyl chloride (TMC), which has excellent performance. It is announced. Although Cadette's membranes show good flow rates and salt removal rates, various studies have been conducted to increase the flow rates and improve the salt removal rate of polyamide reverse osmosis composite membranes. It has been continued.

For example, Tomashke's U.S. Patent 4,872,984 (registered in October 1989) (a) to form a liquid layer on a microporous support layer (1) is essentially an aromatic polyamine of monomers having at least two amine functional groups. Applying a microporous support as an aqueous solution consisting of a reactant and (2) an amine salt of the monomer, (b) the amine reactive reactant on average has at least about 2.2 acyl halides per molecule of the reactant, and the polyfunctional acyl halide or Contacting the liquid layer with an organic solvent solution of an aromatic amine reactive reactant of a monomer consisting essentially of a mixture; and (c) drying the product of step 2 to form the permeable osmosis membrane. Presented.

In addition, Chau U.S. Patent 4,983,291 (registered in January 1991) introduced a membrane for making a polymerization reactant on or in a porous support layer. CHO's patent applies an aqueous polyamine solution containing a polar aprotic solvent that does not react with an amine, a polyhydric compound, and an acid acceptor to apply a support layer, remove the excess solution, and then dissolve the polyacyl halide. The solution was contacted for a sufficient time for polymerization to occur on the support layer, and the composite membrane thus obtained was treated with hydroxy polycarboxylic acid, polyamino alkylene polycarboxylic acid, amine salt of acid such as sulfuric acid, amino acid, multi-acid inorganic acid, and the like and dried. To obtain a reverse osmosis composite membrane.

Hirose's U.S. Patent No. 5,614,099 (registered in January 1991) is characterized in that the reverse osmosis composite membrane has an average roughness of at least 55 nm, and the polyamide type surface layer is an amino functional group. It consists of a reactant between a compound having a group and a polyfunctional acid halide having an acyl acid functional group. For example, in order to form a solution layer on a support layer, a polymer thin film is coated with a m-phenylenediamine solution and then a tree A method of forming a polymer thin film on a support layer by drying the film obtained by contacting with a trimesic chloride organic solution with hot hot air was presented.

However, the reverse osmosis composite membranes prepared by the above methods have not reached a satisfactory level in terms of physical properties, and development of more economic methods is required.

It is an object of the present invention to provide a method for producing a polyamide reverse osmosis composite membrane having improved performance compared to the aforementioned methods.

The present invention provides a polyamide obtained by reacting an aqueous polyfunctional amine solution containing a polyfunctional amine and a polar compound with an organic solution containing an amine reactive compound selected from the group consisting of polyfunctional acyl halides, polyfunctional sulfonyl halides, and polyfunctional isocyanates. In the reverse osmosis polyamide composite membrane produced by forming a membrane on a porous support layer, the polar compound is dipropylene glycol monoalkyl ether, 1,3-propanediol alkyl substituent, 1,2-alkanediol, diethylene glycol hexyl ether, di Ethylene glycol t-butyl methyl ether, triethylene glycol dimethyl ether, 1-x-cyclohexane dimethanol (x is an integer of 2 to 4) or alkoxy ethanol or propylene glycol and alkoxyethanol, sulfoxide Side derivatives and alkoxyethanol, urea and alkoxyethanol, diethylene glycol hexyl ether Two or more polar compounds such as le, propylene glycol, diethylene glycol hexyl ether and sulfoxide derivatives, diethylene glycol hexyl ether and glycerol, 1,3-propanediol alkyl substituents and sulfoxide derivatives, propylene glycol and propylene glycol monoalkyl ethers It relates to a method for producing a reverse osmosis polyamide composite membrane, characterized in that produced in combination.

Hereinafter, the present invention will be described in detail.

In the present invention, the reverse osmosis composite membrane is obtained by forming a polyamide membrane on a porous support layer, wherein the polyamide membrane is an aqueous solution composed of a mixed solution and a polyfunctional amine described later, polyfunctional acyl halide, polyfunctional sulfonyl halide, and polyfunctional isocyanate. It is obtained as a result of the reaction with an organic solution containing an amine-reactive substance consisting of.

In the present invention, the reverse osmosis composite membrane is coated with a porous support layer with an aqueous solution composed of a polyfunctional amine and a mixed solution to be described later to form a liquid membrane on the surface of the porous support layer. It can be obtained by contacting with an organic solution containing an amine-reactive substance such as to cause the amine-reactive compound to undergo interfacial polymerization with the polyfunctional amine, thereby forming a crosslinked interfacial polyamide membrane on the porous support layer and drying it. .

In general, the porous support layer used in the present invention is a microporous support layer, which does not need to be very specific, but has a pore enough to allow the permeate to pass through as a pore of a general polymer material and has a pore enough to prevent problems when the ultrathin film is crosslinked. do. The pore size of the preferred support layer is in the range of 1 to 300 nm, and when it exceeds 300 nm, the ultrathin film is depressed between the pores and collapses the flat state. Materials of the microporous support layer useful in the present invention include polysulfone, polyethersulfone, polyimide, polyacrylonitrile, polypropylene, and halogenated substituent polymer such as polyvinylidene fluoride. In the present invention, the thickness of the microporous support layer is not critical, but is preferably approximately 25 to 125 μm.

The polyfunctional amine used in the present invention is an amine of a monomer having at least two or more amine functional groups, and more preferably two to three amine functional groups. The amine functional group generally has a primary or secondary amine functional group (preferably primary functional group). Examples of suitable polyamines are metaphenylenediamine, paraphenylenediamine and substituted derivatives thereof, wherein the substituents are alkyl groups such as methyl, ethyl, ethoxy groups, hydroxyalkyl groups, hydroxy groups, or halogen atoms And the like. Still other examples of suitable polyamines include 1,3-propanediamine, alkanediamine with N-alkyl or N-aryl substituents of 1,3-propanediamine, cycloaliphatic primary amines such as cyclohexanediamine, piperazine, Cycloaliphatic secondary diamines such as piperazine alkyl derivatives, aromatic secondary amines such as N, N'-dimethyl-1,3-phenylenediamine, N, N'-diphenylethylenediamine, benzidine, xylene diamine and Derivatives thereof.

In the present invention, it is used to make an aqueous amine solution of 0.1 to 20% by weight (more preferably 0.5 to 8.0% by weight), which is mixed with a water solvent and one or two polar compounds to make an aqueous solution. The prepared aqueous solution is used to adjust within the range of PH 7 ~ 13, wherein the pH can be adjusted by containing 0.001 ~ 5% by weight of a basic acid acceptor. Acid acceptors include hydroxides, carboxylates, carbonates, borates, phosphates of alkali metals, and trialkyl amines.

Polar compounds usable in the present invention include di (propylene glycol) monoalkyl ether, alkyl derivatives of 1,3-propanediol, di (ethylene glycol) hexyl ether, di (ethylene glycol) -tert-butylmethyl ether, tri ( Ethylene glycol) dimethyl ether and 1, x-cyclohexanedimethanol (x is an integer of 2-4, 1,2-, 1,3-, 1,4-cyclohexanedimethanol) In the di (propylene glycol) monoalkyl ether means di (propylene glycol) methyl ether, di (propylene glycol) butyl ether, di (propylene glycol)-tert- butyl ether, the alkyl derivative of 1,3-propanediol 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,3-pentanediol, 2,2-diethyl -1,3-propanediol, 2,2-dimethyl-1,3-propanediol and the like. Other polar compounds that can be used include propylene glycol propyl ether, propylene glycol butyl ether, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol. Alkanediols and the like.

In the present invention, the content of the polar compound in the mixed solution is preferably in the range of about 0.01 to 8.0% by weight (more preferably, 0.1 to 4.0% by weight). However, when the polar compound of the mixed solution is di (ethylene glycol) hexyl ether, the content thereof is preferably about 0.01 to 0.3% by weight (more preferably about 0.1 to 0.3% by weight). In addition, when the polar compound of the mixed solution is 2-ethyl-1,3-hexanediol, a mixed solution having a content of the polar compound of 0.1 to 1.0% by weight is preferable.

In the present invention, the use of alkoxyethanol as the polar compound is another feature, and the preferred amount of the alkoxy ethanol is 0.05 to 4.0% by weight. Examples of alkoxyethanol include 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol and the like. More preferably, the content of alkoxy ethanol in the mixed solution is in the range of 0.05 to 3.0% by weight (most preferably 0.5 to 2.0% by weight).

In another aspect of the present invention, a combination of two or more polar materials of a polar compound is used, and two or more polar compound combinations include the following. That is, propylene glycol and alkoxy ethanol; Urea and alcoholsethanol; Alkoxyethanol and urea derivatives, where urea derivatives are compounds in which at least one hydrogen is substituted with alkyl; Glycerol and alkoxyethanol; Di (ethylene glycol) hexyl ether and propylene glycol; Di (ethylene glycol) hexyl ether and sulfoxide derivatives; Di (ethylene glycol) hexyl ether and glycerol; 1,3-propanediol alkyl substituents and sulfoxide derivatives; There are a combination of propylene glycol and propylene glycol monoalkyl ether, and the like, and sulfoxide derivatives include dimethyl sulfoxide, butyl sulfoxide, methylphenyl sulfoxide, tetramethylene sulfoxide and the like. The total content of such a combination of polar compounds is preferably such that 0.01 to 8% by weight (more preferably 3 to 4% by weight) of the mixed solvent.

Although not intended to limit the present invention to a specific theory, the effect of increasing the absorbency at the surface of the polar compound porous support layer specifically used in the present invention and the effect of preventing the membrane from drying during the evaporation of excess organic solvent after the interfacial polymerization reaction It is inferred to increase the flow rate of the membrane.

The amine reactive reactants used in the present invention are one or a mixture of two or more selected from the group consisting of polyfunctional acyl halides, polyfunctional, sulfonyl halides, polyfunctional isocyanates, and the like, which compounds are monomers, aromatic, and Functional acyl halides are considered essential and are preferably two or three carboxylic acid halides, such as trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride or combinations thereof, but other suitable amine reactivity Compounds may also be used.

The organic solvent solution used for the transport of the amine-reactive compound is composed of an organic solvent that does not mix well with water, and the amine-reactive compound is approximately 0.005 to 5% by weight (more preferably 0.01 to 0.5% by weight) in the organic solvent. It is good to exist in the range of. Suitable organic solvents for the present invention include hexane, cyclohexane, heptane, alkanes having 8 to 12 carbon atoms, halogen substituted hydrocarbons of freons, etc. Among them, mixed organic solutions having 8 to 12 carbon alkanes have the best performance. Do.

After coating the above-described aqueous solution on the porous support layer by hand coating or continuous process, the excess solution of the support layer is removed by a suitable method such as rolling, spawning or air napping, and then immersed in the organic layer described above on the applied support layer material. Alternatively, the result obtained by holding the reaction for 5 seconds to 10 minutes (more preferably, 20 seconds to 4 minutes) after contacting with a spray method is dried at 40 ° C. for about 1 minute, and then, for 1 minute to 30 minutes in a basic aqueous solution. After treatment, such as washing with water for a minute.

<Example 1>

The polysulfone support layer formed on the 140 μm thick nonwoven fabric was immersed in an aqueous layer containing 2.0 wt% MPD, 2.0 wt% 2-butoxyethanol, and 2.0 wt% propylene glycol. After removing the excess solution of the support layer, it was immersed in the solution layer dissolved 0.1% by weight of trimezoyl chloride with an isopa (EXXON company) solvent for 1 minute and then the excess solution is removed.

The resulting composite membrane is dried at room temperature for 1 minute, and then washed with an aqueous solution of Na ₂ CO ₃ at about 40 to 60 ° C. for 30 minutes or more. The reverse osmosis membrane thus obtained was measured at a pressure of 225 psi in a 2,000 ppm NaCl aqueous solution to obtain a 98.2% salt removal rate and a flow rate of 27.5 gfd.

Example 2

The reverse osmosis membrane was carried out in the same manner as in Example 1, except that 1.0 wt% 2-butoxyethanol and 1.0 wt% urea were used instead of 2.0 wt% 2-butoxyethanol, 2.0 wt% propylene glycol. Was prepared, and the physical properties were measured to obtain a flow rate of 98.8% salt removal rate, 27.0gfd.

<Example 3>

The same procedure as in Example 1 was repeated except that 2.0 weight% 2-butoxyethanol and 2.0 weight% dimethyl sulfoxide were used instead of 2.0 weight% 2-butoxyethanol, 2.0 weight% propylene glycol. The permeation membrane was prepared, and the physical properties were measured to obtain a salt removal rate of 96.4% and a flow rate of 32.2 gfd.

<Example 4-18 and Comparative Example A-X>

A reverse osmosis membrane was prepared in the same manner as in Example 1 except for using the polar compound of Table 1 below instead of 2.0 wt% of 2-butoxyethanol and 2.0 wt% of propylene glycol, and measured physical properties thereof. Table 1 shows.

division additive Concentration (% by weight) Flow rate (gfd) Salt Exclusion Rate (%) Comparative Example A - 0 16 97 Example 4 Butyl sulfoxide / 2-butoxyethanol 1/2 39.0 91.9 Example 5 Tetramethylene sulfoxide / 2-butoxyethanol 1/2 29.3 94.7 Comparative Example B Propylene glycol 2 17.1 97.8 Comparative Example C Propylene glycol 8 18.8 95.8 Example 6 2-ethoxyethanol / propylene glycol 2/2 30.4 98.2 Example 7 2-propoxyethanol / propylene glycol 2/2 27.2 99.0 Example 8 Propylene Glycol Butyl Ether / Propylene Glycol 2/2 27.8 97.6 Comparative Example D Propylene Glycol Butyl Ether 4 3.0 90.0 Comparative Example E Propylene Glycol Butyl Ether 2 19.7 86.6 Example 9 Propylene Glycol Propyl Ether 2 22.6 94.8 Example 10 Propylene Glycol Propyl Ether / Propylene Glycol 2/2 23.3 98.7 Example 11 2-butoxyethanol / N-methylpyrrolidone 2/2 22.2 97.5 Comparative Example F N-methylpyrrolidone 2 18.6 97.4 Example 12 2-butoxyethanol / N, N-dimethylformamide 2/2 25.6 94.9 Example 13 2-butoxyethanol / glycerol 1/2 31.8 96.5 Comparative Example G 2-propoxyethanol 8 7.8 94.1 Comparative Example H 2-butoxyethanol 8 5.7 91.0 Example 14 2-butoxyethanol 4 18.4 96.1 Example 15 2-butoxyethanol 3 18.0 98.1 Example 16 2-butoxyethanol 2 22.3 98.9 Example 17 2-butoxyethanol One 26.0 98.3 Example 18 2-butoxyethanol 0.5 25 97.7

division additive Concentration (% by weight) Flow rate (gfd) Salt Exclusion Rate (%) Comparative Example I Di (ethylene glycol) butyl ether / propylene glycol 2/2 15.1 97.8 Comparative Example J Dimethyl sulfoxide / propylene glycol 2/2 10.7 93.4 Comparative Example K Dimethyl Sulfoxide / Glycerol 2/2 8.7 94.4 Comparative Example L Dimethyl sulfoxide 2 20.1 96.5 Comparative Example M Butyl sulfoxide One 29.3 94.4 Comparative Example N Tetramethylene sulfone 2 26.2 95.1 Comparative Example O Tetramethylene sulfone / 2-butoxyethanol 2/2 18.0 94.3 Comparative Example P Di (ethylene glycol) diethyl ether / propylene glycol 2/2 21.2 98.1 Comparative Example Q Di (ethylene glycol) dimethyl ether 2 20.7 97.0 Comparative Example R Di (ethylene glycol) diethyl ether / propylene glycol 2/2 20.5 97.8 Comparative Example S Di (ethylene glycol) diethyl ether / propylene glycol 2/2 17.8 97.6 Comparative Example T Di (ethylene glycol) ethyl ether 2 17.7 96.7 Comparative Example U Di (ethylene glycol) ethyl ether / propylene glycol 2/2 22.7 97.3 Comparative Example V Di (ethylene glycol) methyl ether 2 14.4 95.1 Comparative Example W Di (ethylene glycol) methyl ether / propylene glycol 2/2 15.4 97.5 Comparative Example X Acetone / propylene glycol 2/2 17.9 96.6

<Examples 19-34 and Comparative Example Y-EE>

A reverse osmosis membrane was prepared in the same manner as in Example 1 except that the polar compound of Table 2 was used instead of 2.0% by weight of 2-butoxyethanol and 2.0% by weight of propylene glycol, and the physical properties thereof were measured. Table 2 shows.

division additive Concentration (% by weight) Flow rate (gfd) Salt Exclusion Rate (%) Comparative Example A - 0 16 97.0 Example 19 Di (ethylene glycol) t-butyl methyl ether 2 26.2 98.6 Comparative Example Y Di (ethylene glycol) diethyl ether 2 20.7 97.0 Example 20 Di (ethylene glycol) hexyl ether 2 200 0 Example 21 Di (ethylene glycol) hexyl ether 0.5 0 0 Example 22 Di (ethylene glycol) hexyl ether 0.4 0 0 Example 23 Di (ethylene glycol) hexyl ether 0.3 32.0 95.9 Example 24 Di (ethylene glycol) hexyl ether 0.2 29.4 97.5 Example 25 Di (ethylene glycol) hexyl ether 0.1 27.7 96.2 Comparative Example Z Di (ethylene glycol) butyl ether 2 13.6 97.4 Comparative Example AA Di (ethylene glycol) butyl ether One 23.1 95.3 Comparative Example BB Di (ethylene glycol) butyl ether 0.4 19.8 93.8 Comparative Example CC Di (ethylene glycol) butyl ether 0.3 19.3 95.5 Comparative Example DD Di (ethylene glycol) butyl ether 0.2 20.0 95.3 Comparative Example T Di (ethylene glycol) ethyl ether 2 17.7 96.7 Comparative Example V Di (ethylene glycol) methyl ether 2 14.4 95.4 Example 26 Tri (ethylene glycol) dimethyl ether 2 28.5 97.5 Comparative Example EE Tri (ethylene glycol) 2 18.8 96.7 Example 27 2-ethyl-1,3-hexanediol 0.2 26.0 98.2 Example 28 1,4-cyclohexanedimethanol 2 25.5 96.0 Example 29 Di (propylene glycol) 2 25.2 96.8 Example 30 Di (propylene glycol) methyl ether 2 27.0 96.0 Example 31 Di (ethylene glycol) hexyl ether / propylene glycol 0.2 / 2 31.3 97.1 Example 32 Di (ethylene glycol) hexyl ether / glycerol 0.2 / 2 31.1 97.4 Example 33 Di (ethylene glycol) hexyl ether / dimethyl sulfoxide 0.2 / 2 33.1 97.0 Example 34 2-ethyl-1,3-hexanediol / dimethylsulfoxide 0.2 / 2 28.2 97.0

As can be seen from the above examples and comparative examples, when the reverse osmosis membrane is prepared by adding the polar compound according to the present invention to the amine aqueous solution, the salt removal rate is excellent compared to the conventional method using the amine aqueous solution, and the usefulness such as high flow rate is shown. You can get it.

Claims (8)

A polyamide membrane obtained by reacting a polyfunctional amine aqueous solution containing a polyfunctional amine and a polar compound with an organic solution containing an amine reactive compound selected from the group consisting of polyfunctional acyl halides, polyfunctional sulfonyl halides, and polyfunctional isocyanates. In the reverse osmosis polyamide composite membrane produced by forming a polymer, the polar compound used in the polyfunctional amine aqueous solution is dipropylene glycol monoalkyl ether, 1,3-propanediol alkyl substituent, 1,2-alkanediol, diethylene glycol Hexyl ether, diethylene glycol t-butyl methyl ether, triethylene glycol dimethyl ether, 1-x-cyclohexane dimethanol (x is an integer of 2 to 4) or alkoxy ethanol or propylene glycol Alkoxyethanol, sulfoxide derivatives and alkoxyethanol, urea and alkoxyethanol, di Two such as ethylene glycol hexyl ether and propylene glycol, diethylene glycol hexyl ether and sulfoxide derivative, diethylene glycol hexyl ether and glycerol, 1,3-propanediol alkyl substituent and sulfoxide derivative, propylene glycol and propylene glycol monoalkyl ether Reverse osmosis polyamide composite membrane production method characterized in that consisting of the above polar compound combinations. The method of claim 1, wherein the polyamide membrane is formed on the porous support layer by using a method of reacting an aqueous polyfunctional amine solution with an amine reactive compound on the porous support layer. The method of claim 1, wherein the polyamide membrane is formed on the porous support layer, and the aqueous polyfunctional amine solution is coated on the porous support layer to form a liquid membrane on the porous support layer. Method for producing a reverse osmosis polyamide composite membrane, characterized in that for use in contact with the amine reactive compound selected from the group consisting of interfacial polymerization. The method of claim 1, wherein the porous support layer is made of polysulfone, polyethersulfone, polyimide, polyamide, polypropylene, and polyvinylidene fluorite. The polar compound of claim 1, wherein the polar compound is dipropylene glycol monoalkyl ether, 1,3-propanediol alkyl substituent, 1,2-alkanediol, diethylene glycol dimethyl ether, 1-x-cyclohexanedimethanol (x is 2 In the case of using a compound selected from the group consisting of (integer of ~ 4) the amount of the reverse osmosis polyamide composite membrane production method, characterized in that the amount of 0.01-8.0% by weight of the mixed aqueous solution. The method for producing a reverse osmosis polyamide composite membrane according to claim 1, wherein when the alkoxy ethanol is used as the polar compound, the amount of the alkoxyethanol is 0.05-3.0% by weight of the mixed aqueous solution. The method of manufacturing a reverse osmosis polyamide composite membrane according to claim 1, wherein when using a combination of two or more polar solvents as the polar compound, the amount thereof is 0.01-8% by weight of the mixed aqueous solution. The method according to claim 1, wherein the amount of diethylene glycol hexyl ether used as the polar compound is 0.01-3% by weight of the mixed aqueous solution.