KR101184213B1 - Reveres osmosis membrane showing high boron rejection and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a reverse osmosis membrane and a method for producing the same having excellent boron removal performance.
The reverse osmosis membrane of the present invention is composed of a polyamide layer formed by interfacial polymerization of a polyfunctional acid halogen compound-containing solution including a porous support and a polyfunctional amine solution and a specific isophthaloyl chloride substituted with an alkyl group. As the alkyl group of isophthaloyl chloride occupies a certain space without participating in the amide formation, the gap between the amides can be narrowed to realize a reverse osmosis membrane having a compact pore size, thereby forming an electroless organic compound or a non-electrolyte. The removal efficiency of the ionization compound is improved, and in particular, the boron removal rate is excellent, so it is excellent in application as a separation membrane for water treatment.

Description

REVERES OSMOSIS MEMBRANE SHOWING HIGH BORON REJECTION AND MANUFACTURING METHOD THEREOF

The present invention relates to a reverse osmosis membrane having excellent boron removal performance and a method for preparing the same, wherein a solution containing a polyfunctional acid halogen compound containing a porous support and an amine solution and isophthaloyl chloride substituted with an alkyl group of C ₁ to C ₃ It is composed of a polyamide layer formed by interfacial polymerization, and as the pore size is densely formed in the polyamide layer, the present invention relates to a reverse osmosis membrane having excellent boron removal performance and a method of manufacturing the same.

The concentration of boron in irrigation water plays an important role in the production and growth of crops, with high concentrations causing yellow spots on plant leaves, accelerating decay, and ultimately ending plant growth. The presence of high concentrations of boron in drinking water can impair human reproductive function. Therefore, the European Union (EUOPEAN UNION) regulates the maximum allowable value of boron in drinking water at 1 ppm and the US (WHO) regulates it at 0.5 ppm or less.

Boron generally varies greatly in pH depending on pH. For example, at low pH conditions, most of them are in the form of boric acid (H ₃ BO ₃ ), and they are difficult to be removed (departed) from the membrane because they have a small molecular size and are not charged and have weak electrical repulsion with the surface of the separator. . However, as the pH increases, the ionization proceeds, the molecular size becomes relatively large and becomes negatively charged, thereby removing a large amount of boron due to the electrical repulsion with the negatively charged separator surface.

 Equation 1

H ₂ BO ₃ ↔ H ⁺ + H ₂ BO ₃ ^- pKa 9.14

 Equation 2

H ₂ BO ₃ ^- ↔ H ⁺ + HBO ₃ ^{2 -} pKa 12.74

 Equation 3

HBO ₃ ^{2 -} ↔ H ⁺ + BO ₃ ^{3 -} pKa 13.8

Generally, seawater has a pH of about 7 to 8, and contains 4 to 5 ppm of boron, which is present in the form of boric acid. Specifically, at pH 7, unionized boric acid (H ₃ BO ₃ ) accounts for 99.3%, and at pH 8, 93.2%.

For most seawater desalination, boron removal is 82-86% at pH 8. Applying a 86% removal rate compared to raw water, the concentration of treated water will be over 0.5 ppm, which is above the WHO regulation.

The reverse osmosis membrane used in the desalination process of seawater is the first starting point in the early 1960s when Loeb and Sourirajan proposed an asymmetric cellulose diacetate membrane. However, while the cellulose diacetate membrane has an advantage of low cost, it has been pointed out that the vulnerable to microorganisms, hydrolysis in the presence of strong bases, and a narrow range of use temperature and pH.

Therefore, as a study for improving these disadvantages, attention has been paid to a separator of a new material, such as polyamide, polyurethane, aromatic polysulfone, aromatic polyamide.

In general, a reverse osmosis membrane or a reverse osmosis composite membrane consists of a support layer for maintaining mechanical strength and an active layer having selective permeability. Recently, a reverse osmosis composite membrane comprising an aromatic polysulfone as a porous support layer and a polyamide as an active layer has been developed and commercialized. It is becoming.

The reverse osmosis composite membrane may be prepared by a thin layer dispersion method, an immersion coating method, a vapor deposition method, a Langmuir-Blodgett method, an interfacial polymerization method, and the most commonly used method is cadette. Interfacial polymerization described by US Patent No. 4,277,344.

The above-described invention discloses a technique for an aromatic polyamide composite membrane obtained by interfacial polymerization of an aromatic polyfunctional amine containing at least two primary amine substituents and an aromatic acyl halide having at least three acyl halide substituents. have. In a preferred embodiment, after coating the porous polysulfone support layer with m-phenylendiamine dissolved in water, excess metaphenylenediamine solution is removed from the coated porous support, and the coated support is Contact is made with a solution of trimesoylchloride dissolved in a Freon TF solvent (trichlorotrifluoroethane). As a result, the polysulfone / polyamide composite membrane showed excellent permeate flow rate and salt rejection ratio, but according to the demand for further improved membrane performance, studies on the increase in permeate flow rate and salt rejection rate of the polyamide reverse osmosis composite membrane were continuously conducted. It is becoming.

As an example, Uemura has suggested another reactant, an aromatic halogen, for the production of crosslinked aromatic polyamide, and the aromatic halogen is represented by the following structure (US Pat. No. 4,761,234).

Formula 1

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

　　　

R ₁₁ to R ₁₆ may be represented by a quick reaction acyl halide group or another substituent, and the number of acyl halide groups is small, usually between 2 and 6, and preferably 2 or 3 are easy to handle. -H, -OCH ₃ , -CH ₃ , -C ₂ H ₅ , -C ₃ H ₇ , -F, -Cl, -Br, and -I, which are substituents other than the acyl halide group forming the above structure, are crosslinked Although not impeded to form a bound polyamide, the substituents theoretically suggest that they are not directly adjacent to the polyamide group, but there are no examples of boron removal rates and no mention of improving boron removal rates.

In addition, Hiroki Tomioka reports that amines other than ammonia can be contacted with a polyamide reverse osmosis membrane to produce a reverse osmosis membrane having a high boron removal rate by interfacial polymerization [US Patent No. 727909]. . However, the reverse osmosis membrane also shows a high salt removal rate and excellent permeation performance in seawater desalination, which is unparalleled. However, non-electrolyte organic compounds such as isopropyl alcohol (IPA) or boron removal rate are still maintained. It does not solve the problem of low.

In the study of the reverse osmosis membrane, there are methods for improving the removal rate, first, the method of changing the pH and second, the method of changing the pore size.

More specifically, as the pH of the treated water is increased, the removal rate rises vertically. In other words, as the pH is increased boric acid (H ₃ BO ₃₎ borate ttuin a negative charge in the form of (H ₂ BO ₃ ^-) as proceeds in the form of molecular size is relatively larger as, due to the electric repulsive force between the ttuin negatively charged membrane surface increases to be. As a result, an experimental result of completely removing boron at 99% or more at pH 10 and 100% at pH 12 has been published.

However, when the pH of raw water is raised to increase the removal rate of boron, scaling of calcium carbonate and magnesium hydroxide present in seawater becomes severe, and finally, the flow rate of permeate is reduced and the membrane life is shortened. Cause. In addition, there is a disadvantage in that the cost is increased by using a large amount of the buffer solution to lower the pH.

In addition, according to T. Uemura at the 2007 Asian Conference on Desalination & Water Reuse, the pore size of the polyamide layer of the reverse osmosis membrane was measured using molecular design techniques based on mass transfer mechanisms. As a result, the size of 0.56 ~ 0.70nm, the smaller the pore size reports the correlation that the boron removal rate increases, and the method of controlling the pore size to improve the boron removal rate in the reverse osmosis membrane may be one variable It was announced. However, when the separator is manufactured, a method of controlling the pore size is not easy, and the small pore size has a problem of lowering the overall flow rate.

Thus, the present inventors tried to manufacture a reverse osmosis membrane having a higher boron removal performance than the conventional in the reverse osmosis membrane, the porous support and the polyamide layer formed on the porous support, but tightly controlled pores of the polyamide layer By providing a reverse osmosis membrane having excellent boron removal performance and a reverse osmosis membrane prepared therefrom, the present invention has been completed.

An object of the present invention is made of a porous support and a polyamide layer formed on the porous support, the pore of the polyamide layer is tightly controlled to provide a reverse osmosis membrane having excellent boron removal efficiency.

Another object of the present invention is to provide a method for preparing a reverse osmosis membrane having excellent boron removal efficiency.

In order to achieve the above object, the present invention is an interfacial polymerization of a polyfunctional acid halogen compound containing a polyfunctional amine solution and isophthaloyl chloride substituted with a C ₁ ~ C ₃ alkyl group on the porous support and the porous support It provides a reverse osmosis membrane consisting of a polyamide layer formed.

The polyfunctional amine solution may be an aqueous solution containing 0.5 to 10% by weight of meta phenylene diamine.

In this case, the polyfunctional acid halogen compound-containing solution is a solution containing 0.01 to 2% by weight of isophthaloyl chloride and 0.01 to 2% by weight of trimezoyl chloride substituted with an alkyl group of C ₁ ~ C ₃ is an aliphatic hydrocarbon solvent. Preferably, the isophthaloyl chloride substituted with an alkyl group of C ₁ ~ C ₃ is preferably 5-methyl-isophthaloyl chloride.

The porous support is preferably any one selected from the group consisting of polysulfone, polyethersulfone, polyimide, polypropylene and polyvinylidene fluoride satisfying an average pore size of 1 to 500 nm.

Furthermore, the present invention provides a method for preparing the reverse osmosis membrane, specifically 1) applying a multifunctional amine solution on a porous support, 2) C ₁ ~ C coated porous support with the multifunctional amine solution ₃ of Contacting the isophthaloyl chloride-containing polyfunctional acid halogen compound solution substituted with an alkyl group to form a separator by interfacial polymerization, 3) drying the separator formed by the interfacial polymerization at 18 to 50 ° C. for 30 seconds to 3 minutes; and 4) It provides a method for producing a reverse osmosis membrane consisting of the step of immersing the separator in a base aqueous solution of 18 ~ 95 ℃ for 1 to 30 minutes.

In this case, the polyfunctional amine solution is an aqueous solution containing 0.5 to 10% by weight of meta phenylene diamine, the polyfunctional acid halogen compound is C ₁ ~ C ₃ 0.01 to 2% by weight of isophthaloylchloride and 0.01 to 2% by weight of trimezoyl chloride substituted with an alkyl group are solutions contained in aliphatic hydrocarbon solvents.

C ₁ to C ₃ The isophthaloyl chloride substituted with an alkyl group is preferably 5-methyl-isophthaloylchloride.

The reverse osmosis membrane of the present invention is composed of a polyamide layer formed by interfacial polymerization of a porous support and an amine solution and a solution containing a polyfunctional acid halogen compound containing a specific isophthaloyl chloride substituted with a C ₁ to C ₃ alkyl group. As the alkyl group of isophthaloyl chloride during the interfacial polymerization process occupies a certain space without participating in the amide formation, the gap between the amides can be narrowed to realize a reverse osmosis membrane having a compact pore size. Thus, the reverse osmosis membrane of the present invention is improved in the removal efficiency of the non-electrolytic organic compound or non-ionized compound, in particular, excellent boron removal rate is excellent application to the separation membrane for water treatment.

1 is a schematic structure of metaphenylenediamine-5-methyl-isophthaloyl chloride (MPD-5-methyl-IPC) to which isophthaloyl chloride substituted with a methyl group is applied.
2 is a schematic structure of metaphenylenediamine-isophthaloyl chloride (MPD-IPC) to which isophthaloyl chloride is applied.

Hereinafter, the present invention will be described in more detail.

The present invention is a reverse osmosis membrane composed of a polyamide layer formed by interfacial polymerization of a porous support and an amine solution and a solution containing a specific isophthaloyl chloride substituted with an alkyl group of C ₁ to C ₃ .

Specifically, the polyamide layer has been formed the chloride one of isophthaloyl of certain substituted with a polyfunctional acid halide compound with an alkyl group of C ₁ ~ C ₃ is applied, C ₁ ~ C ₃ alkyl group is directly involved in the amide form of the Without narrowing the gaps between the amides to form dense pores, and thus the non-electrolytic organic compounds or non-ionized compounds, in particular, the boron removal rate is excellent.

More specifically, referring to FIGS. 1 and 2, FIG. 1 to which 5-methyl-isophthaloyl chloride substituted with a methyl group at position 5 is applied, has a substituent of methyl compared to FIG. 2 to which a conventional isophthaloyl chloride is applied. As a result, it can be confirmed that a certain portion of space is secured.

The polyfunctional amine solution applicable to the present invention may contain 0.1 to 20% by weight, more preferably 0.5 to 10% by weight of the multifunctional amine on the aqueous solution. The physical properties of the reverse osmosis composite membrane prepared using the same permeate flux is 41gfd or more and at the same time saline removal rate satisfies 97.5% and has a stable characteristic to the change of pH. In this case, when the content of the polyfunctional amine is less than 0.1% by weight, the polyamide separation membrane may not be properly formed, and when the content exceeds 20% by weight, the permeate flow rate may decrease significantly.

In particular, according to the present invention, by applying the above-described optimal amount of the multifunctional amine solution, it is difficult to satisfy the conventional salt removal rate and high permeability at the same time, and also the reverse osmosis membrane which reacts sensitively to the pH change in the manufacturing process of the composite membrane. Can improve the problem.

The polyfunctional amine is a polyamine having at least two amine functional groups, more preferably two to three amine functional groups, wherein the amine functional groups are typical primary or secondary amine functional groups, preferably primary amines. It is a functional group.

Preferred examples of the polyamine include aromatic primary diamines such as meta-phenylenediamine and para-phenylenediamine and substituents derived therefrom, and the substituents are alkyl groups such as methoxy groups or ethoxy groups, and methoxy groups. Or alkoxy groups such as ethoxy groups, hydroxy alkyl groups, hydroxy groups or halogen atoms.

Still other examples of preferred polyamines include alkanediamines such as 1,3-propane diamine and analogs with or without N-alkyl or aryl substituents, cycloaliphatic primary diamines such as cyclohexane diamine, piperazine and alkyl derivatives thereof. Aromatic aliphatic diamines such as cycloaliphatic secondary diamines, N, N'-dimethyl-1,3-phenylenediamine, N, N'-diphenylethylene diamine, benzidine, xylenediamine and derivatives thereof, and the like. .

Particularly preferred polyamines of the invention are aromatic primary diamines, more preferably meta phenylenediamine. At this time, the meta phenylene diamine is preferably contained in an aqueous solution of 0.5 to 10% by weight, preferably 1 to 3% by weight to improve the salt removal rate, it is possible to secure a salt removal rate of 99% or more of the polyamide separation membrane.

The polyfunctional acid halogen compound-containing solution applicable to the present invention is a solution prepared by dissolving an aromatic polyfunctional acyl halide having a polyfunctional acyl halide substituent in an aliphatic hydrocarbon solvent, and an alkyl group of C ₁ to C ₃ as an acyl halide. Isophthaloylchloride substituted with.

More specifically, the polyfunctional acid halogen compound-containing solution is 0.01 to 2% by weight of isophthaloyl chloride and 0.01 to 2% by weight of trimezoyl chloride, preferably substituted with an alkyl group of C ₁ to C ₃ as a halide in an aliphatic hydrocarbon solvent. Preferably, 0.04 to 0.2% by weight of isophthaloyl chloride and 0.01 to 0.3% by weight of trimesoyl chloride substituted with an alkyl group of C ₁ to C ₃ are dissolved.

At this time, if the content of isophthaloyl chloride and trimezoyl chloride substituted with an alkyl group of C ₁ ~ C ₃ is less than 0.01% by weight is used in too small a small amount of polyamide layer is poor pore control effect of the membrane, If the content exceeds 2% by weight, the flow rate performance is significantly lowered, which is not preferable.

Examples of isophthaloyl chloride substituted with an alkyl group of C ₁ to C ₃ include methyl-isophthaloyl chloride, ethyl-isophthaloyl chloride and propyl-isophthaloyl chloride, in particular 5-methyl-isophthaloyl chloride It is preferable in terms of pore densification and boron removal efficiency of the polyamide layer.

The aliphatic hydrocarbon solvent may dissolve the polyfunctional acid halogen compound at 0.01 to 4% by weight, more preferably 0.05 to 0.3% by weight, and does not participate in the interfacial polymerization reaction and is free of chemical bonds with the polyfunctional acid halogen compound. If the porous support layer is not damaged, it is not particularly limited and used.

Specifically, the aliphatic hydrocarbon solvent may be a mixture of structural isomers of n-alkane having 5 to 12 carbon atoms and saturated or unsaturated hydrocarbons having 8 carbon atoms, or may use 5 to 7 ring hydrocarbons.

The porous support used in the present invention is a general microporous support, and the kind thereof is not particularly limited, but in general, the porous support should be large enough to allow permeate to pass therethrough and should not be large enough to prevent crosslinking of the ultra-thin film formed thereon. The pore size of the support is 1 to 500 nm, and if it exceeds 500 nm, the ultra-thin film is recessed into the pore size after the formation of a thin film, so that the required flat sheet structure cannot be achieved.

Porous supports that can be usefully used in the present invention include polysulfones, polyethersulfones, polyimides, polyamides, polyetherimides, polyacrylonitriles, poly (methyl methacrylates), polyethylene, polypropylenes and polyvinylidene floss And those made of various halogenated polymers such as lides.

Furthermore, the present invention provides a method for producing the reverse osmosis membrane, specifically, after applying the polyfunctional amine solution on the porous support and removing the excess solution, the porous support coated with the multifunctional amine solution is C ₁ Immediately after contacting with an isophthaloyl chloride-containing polyfunctional acid halogen compound solution substituted with an alkyl group of C ₃ to proceed with interfacial polymerization, a separator is formed by interfacial polymerization and dried at 18 to 50 ° C. for 30 seconds to 3 minutes. , The membrane is immersed in a basic aqueous solution of 18 ~ 95 ℃ for 1 to 30 minutes.

Applying the multifunctional amine solution on the porous support may be a method of coating the polyfunctional amine solution on the porous support or immersing the porous support in the multifunctional amine solution, wherein the application time is 0.1 to 10 minutes, Preferably it is carried out for 0.5 to 1 minute.

The polyfunctional amine solution is the same as described above that the polyfunctional amine is dissolved in the aqueous solution, and in particular, the form containing 0.5 to 10% by weight, preferably 1 to 3% by weight of the meta phenylene diamine in the aqueous solution Used.

Contacting the porous support coated with the polyfunctional amine solution to the polyfunctional acid halogen compound solution is crosslinking at a contact interface between the polyfunctional amine solution and the polyfunctional acid halogen compound-containing solution.

At this time, the polyfunctional acid halogen compound-containing solution is the same as described above in the form of a mixed dissolution of isophthaloyl chloride and trimezoyl chloride substituted with an alkyl group of C ₁ ~ C _{3 in} an aliphatic hydrocarbon solvent.

More specifically, the solution containing the polyfunctional acid halogen compound is 0.01 to 2% by weight of isophthaloyl chloride substituted with C ₁ to C ₃ alkyl group in the aliphatic hydrocarbon solvent and 0.01 to 2% by weight of trimezoylcollide, preferably Is a form in which 0.04 to 0.2% by weight of isophthaloyl chloride and 0.01 to 0.3% by weight of trimesoyl chloride substituted with an alkyl group of C ₁ to C ₃ are dissolved.

At this time, examples of the isophthaloyl chloride substituted with the C ₁ ~ C ₃ alkyl group include methyl-isophthaloyl chloride, ethyl-isophthaloyl chloride and propyl-isophthaloyl chloride, in particular 5-methyl-isophthalo Monochloride is preferred in terms of pore densification and boron removal efficiency of the polyamide layer.

After forming the separator by the interfacial polymerization, the separator is dried for 30 seconds to 3 minutes at 18 ~ 50 ℃, to remove impurities or unreacted residue on the surface of the separator, 18 to 95 ℃ to deacyl halide separator Soak for 1 to 30 minutes in aqueous base solution.

At this time, if the drying conditions of the separation membrane is out of the above range, there is a problem that the separation function of the membrane formed undried or over-dried is lowered, and when the membrane is immersed in the base aqueous solution, the temperature of the base aqueous solution is within the above range Deviation is undesirable by affecting the performance of the separator formed for purposes other than deacyl halide purposes.

At this time, the base aqueous solution is not particularly limited, but the use of sodium carbonate solution is preferred.

That is, in the reverse osmosis membrane of the present invention, a polyamide layer is formed by interfacial polymerization of a polyfunctional amine solution and a polyfunctional acid halogen compound solution on a porous support, and isophthalate substituted with a specific alkyl group as a polyfunctional acid halogen compound. By applying monochloride, as the alkyl group of isophthaloyl chloride does not participate in the amide formation during interfacial polymerization, the space between the amides can be narrowed to form a polyamide layer having a small pore size. .

Thus, the reverse osmosis membrane of the present invention is densely formed pores in the polyamide layer is excellent in the non-electrolytic organic compound or non-ionized compound, in particular, can achieve a good boron removal efficiency of 80 to 95% boron removal rate.

At this time, the pore size in the polyamide layer is correlated with the storage removal rate as described above, and as the boron removal rate is increased within a certain range, the pore size is denser.

Hereinafter, the present invention will be described in detail with reference to examples.

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

< Example  1>

Cast 18% by weight of a solution of dimethylformamide and polysulfone to a thickness of about 125 ± 10 μm on a polyester nonwoven fabric, immediately immerse it in distilled water at 25 ° C. for phase transformation, and then sufficiently prepare the nonwoven reinforced polysulfone microporous substrate. After washing with water, the solvent and water in the substrate were substituted, and then stored in pure water at room temperature. Then, the water layer on the surface was removed by a compression method after immersion for 1 minute in an aqueous solution of metaphenylenediamine having a concentration of 3.5% by weight. The substrate was immersed in an organic solution containing 0.1% by weight of trimezoyl chloride and 0.06% by weight of 5-methyl-isophthaloyl chloride for 1 minute, followed by interfacial polymerization, followed by natural drying at room temperature (25 ° C) for 1 minute and 30 seconds. Immediately after forming the polyamide layer, the reverse osmosis composite membrane was prepared by immersing in 0.2 wt% sodium carbonate solution for 2 hours to remove unreacted residues.

< Example  2>

A reverse osmosis composite membrane was prepared in the same manner as in Example 1, except that an organic solution containing 0.1% by weight of trimezoyl chloride and 0.1% by weight of 5-methyl-isophthaloyl chloride was used.

< Example  3>

A reverse osmosis composite membrane was prepared in the same manner as in Example 1, except that an organic solution containing 0.1% by weight of trimezoyl chloride and 0.14% by weight of 5-methyl-isophthaloyl chloride was used.

< Example  4>

A reverse osmosis composite membrane was prepared in the same manner as in Example 1, except that an organic solution containing 0.1% by weight of trimezoyl chloride and 0.18% by weight of 5-methyl-isophthaloyl chloride was used.

< Example  5>

A reverse osmosis composite membrane was prepared in the same manner as in Example 1, except that 0.1% by weight of trimezoyl chloride and 0.20% by weight of 5-methyl-isophthaloyl chloride were used.

< Comparative example  1>

A reverse osmosis composite membrane was prepared in the same manner as in Example 1, except that an organic solution containing 0.1% by weight of trimezoyl chloride and 0.14% by weight of isophthaloyl chloride was used.

< Experimental Example >

The performances of the reverse osmosis membranes prepared in Examples 1 to 5 and Comparative Example 1 were evaluated, and are shown in Table 1 below.

At this time, the performance of the reverse osmosis membrane was measured at 25 ℃ and 800psi sodium chloride (NaCl) and 5ppm aqueous solution of boron concentration of 32,000ppm, boron concentration was measured using an emission spectrophotometer (ICP emission spectrophotometer). The measurement wavelength ranges from 400 to 880 nm and the measurement error is within 1 nm.

division Permeate Flow Rate (GFD) Salt removal rate (%) Boron removal rate (%) Example 1 0.1 wt% TMC,
0.06% by weight MI 14.73 98.99 79.62 Example 2 0.1 wt% TMC,
0.1 wt% MI 13.71 99.24 82.76 Example 3 0.1 wt% TMC,
0.14% by weight MI 13.03 99.36 86.05 Example 4 0.1 wt% TMC,
0.18% by weight MI 12.24 99.30 87.72 Example 5 0.1 wt% TMC,
0.2% MI 11.31 99.04 90.00 Comparative Example 1 0.1 wt% TMC,
0.14% by weight IPC 14.32 99.31 84.97 TMC: Trimezoyl chloride
IPC: isophthaloyl chloride
MI: 5-methyl-isophthaloylchloride

As shown in Table 1, in preparing the reverse osmosis membrane, the polyamide layer was formed by interfacial polymerization of a polyfunctional acid halogen compound containing isophthaloyl chloride substituted with a polyfunctional amine solution and an alkyl group. While showing a good permeation flow rate, the boron geiger ratio is about 80 to 90%, and the boron removal rate is improved as the content of isophthaloyl chloride substituted with an alkyl group increases within a certain range.

On the other hand, Comparative Example 1, to which isophthaloyl chloride without a substituent was substituted with an acyl halide, showed a lower boron removal rate compared to Example 3, to which isophthaloyl chloride substituted with an alkyl group of the same content was applied.

As a result of the above, the reverse osmosis membrane of the present invention implements a polyamide layer having a tightly controlled pore size, so that the salt removal rate, the non-electrolytic organic compound and the non-ionizing compound are excellent, and in particular, the boron removal rate is As it is excellent, it is useful as a separator for water treatment.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications belong to the appended claims.

Claims (9)

Porous support; And
The polyfunctional amine solution on the porous support
0.01 to 0.3% by weight of trimesoyl chloride and C ₁ to C ₃ at position 5 A reverse osmosis membrane comprising a polyamide layer formed by interfacial polymerization of a polyfunctional acid halogen compound-containing solution in which an isophthaloyl chloride substituted with an alkyl group is 0.14 to 0.2% by weight in an aliphatic hydrocarbon solvent. The reverse osmosis membrane according to claim 1, wherein the polyfunctional amine solution is an aqueous solution containing 0.5 to 10 wt% of meta phenylene diamine. delete The method according to claim 1, wherein in the fifth position of C ₁ ~ C ₃ The reverse osmosis membrane, wherein the isophthaloyl chloride substituted with an alkyl group is 5-methyl-isophthaloyl chloride. The method of claim 1, wherein the porous support is any one selected from the group consisting of polysulfone, polyethersulfone, polyimide, polypropylene and polyvinylidene fluoride satisfying an average pore size of 1 to 500nm Reverse osmosis membrane. 1) applying a polyfunctional amine solution on the porous support;
2) 0.01 to 0.3% by weight of trimezoyl chloride and the position of C ₁ to C ₃ at the position 5 0.14 to 0.2% by weight of isophthaloyl chloride substituted with an alkyl group is subjected to interfacial polymerization by contacting a polyfunctional acid halogen compound solution contained in an aliphatic hydrocarbon solvent to form a separator; And
3) drying the separator formed by the interfacial polymerization at 18 to 50 ° C. for 30 seconds to 3 minutes; And
4) immersing the separator in a basic aqueous solution of 18 ~ 95 ℃ 1-30 minutes; manufacturing method of the reverse osmosis membrane consisting of. The method of claim 6, wherein the multifunctional amine solution is an aqueous solution containing 0.5 to 10 wt% of meta phenylene diamine. delete The method according to claim 6, wherein in the fifth position of C ₁ ~ C ₃ Isophthaloyl chloride substituted with an alkyl group is a method for producing the reverse osmosis membrane, characterized in that 5-methyl-isophthaloyl chloride.

Images