KR101258431B1 - Forward osmosis membrane with high flux and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a high flow rate forward osmosis membrane and a method of manufacturing the same.
The positive osmosis membrane of the present invention is a composite membrane structure in which a polyamide layer is formed on a support made of a polymer layer on a nonwoven fabric, and a finger-like structure having a low air migration amount and low solvent resistance Structure) is formed, water can be easily introduced into the inducing solution from the raw water portion through the membrane, and high water permeability and flow rate in the osmotic direction are improved. In addition, in addition to securing a high salt rejection rate, chemical resistance and pH stability according to the structure of the polyamide layer, in particular, the present invention further includes a polyamine salt compound as a water-soluble additive in the formation of the polyamide layer, And reverse solubility of the solute in the induction solution in the reverse osmosis direction can be prevented. Therefore, the forward osmosis membrane of the present invention can be utilized effectively for stably receiving a high concentration of sea water.

Description

TECHNICAL FIELD [0001] The present invention relates to a high flow rate positive osmosis membrane and a method of manufacturing the same,

The present invention relates to a high flow rate forward osmosis membrane and a method of manufacturing the same. More particularly, the present invention relates to a composite membrane having a polyamide layer formed on a support made of a nonwoven fabric having an excellent air permeation amount and a polymer layer having a low pore- As the membrane structure, when an aqueous solution containing a polyamine salt compound in a usual amine-containing aqueous solution and an organic solution containing a polyfunctional acid halide compound are brought into contact with each other at the time of forming the polyamide layer, the high flow rate and reverse diffusion of the salt are minimized And a method for producing the same.

The positive osmosis membrane utilizes the phenomenon that the osmotic pressure generated by the concentration difference between the two solutions is used as the driving force and the low concentration solution moves toward the high concentration solution through the membrane. Reverse Osmosis Membrane (Reverse Osmosis Membrane) is opposite to reverse osmosis membrane.

The positive osmotic membrane plays an important role in maintaining the high osmotic pressure by limiting the movement of the inducing solute, while allowing the water to flow into the inducing solution from the raw water through the membrane. For this purpose, it is most important that the forward osmosis membrane has high water permeability in the osmotic direction and that the solute of the inducing solution is not diffused in the reverse osmosis direction.

In addition, it is necessary to prepare a purified osmosis membrane having high chemical resistance and high pH stability. Hereinafter, the characteristics of the positive osmosis membrane should be summarized as follows.

First, in order to minimize the internal concentration, the porosity of the support layer in the positive osmosis membrane should be high and the pore bending degree should be low.

Second, in order to increase the flow rate of permeated water, the thickness of the positive osmosis membrane should be minimized.

Third, a hydrophilic material is advantageous to minimize the permeation resistance with water.

Fourth, in order to prevent the loss of the induction solution, the solute must not diffuse into the low concentration solution in the high concentration solution.

Conventionally, US Patent No. 2006-0226067 discloses a process for producing a purified osmosis membrane. Cellulose triacetate, which is a hydrophilic material, is used to produce a purified osmosis membrane. More specifically, on a support layer having a thickness of 25 to 75 μm, (FO) mode by using an induction solution in the film, the flow rate of which was 11 gfd level. When the flow rate was 11 gfd High-flow-rate, positive osmosis membranes. However, it has been reported that the membrane prepared above has a disadvantage in that the induction solution of high concentration diffuses the solute in the direction of the low concentration of raw water. In the raw water condition containing a high concentration of salt such as seawater, Which is difficult to apply in practice.

In addition, according to PCT International Patent Application No. 2008-137082, a polysulfone solution is cast on a nonwoven fabric to prepare a membrane having an ultrafiltration membrane level, and a polyfunctional amine and a polyfunctional acyl halide are interfacially polymerized on the membrane surface, Amide reverse osmosis membrane was prepared, and a membrane from which only the nonwoven fabric was removed was applied to the FO system. As a result of evaluating the physical properties of the membrane with the FO mode, a membrane having a salt removal rate satisfying a flow rate of 0.5 gfd and a salt removal rate of 99% or more was proposed. However, since the pure osmosis membrane has a salt removal rate sufficient to separate high-concentration raw water such as seawater, the membrane is practically limited in its use because the flow rate is low.

It is an object of the present invention to provide a high flow rate positive osmosis membrane which can be applied to a high concentration of seawater desalination.

Another object of the present invention is to provide a method for producing the high flow rate positive osmosis membrane.

The present invention relates to an aqueous solution containing a polyamine salt compound in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine in an amount of 0.01 to 2% by weight of a polyamine salt compound and an organic solution layer containing a polyfunctional acid halide compound on a support made of a non- And a polyamide layer formed by polymerization.

The polyamine salt compound is preferably a tertiary polyamine salt compound prepared from a reaction molar ratio of tertiary polyamine and strong acid of 0.5 to 2: 1, and examples of the tertiary polyamine include 1,4-diazabicyclo [ 2,2,] octane (DABCO), 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU), 1,5-diazabicyclo [ (DBN), 1,4-dimethylpiperazine, 4- [2- (dimethylamino) ethyl] morpholine, N, N, N ', N'-tetramethylethylenediamine, N, N'-tetramethyl-1,3-butanediamine, N, N, N'N'-tetramethyl-1,4-butanediamine (TMBD) N, N ', N'-tetramethyl-1,6-hexanediamine (TMHD), 1,1,3,3-tetramethylguanidine (TMGU) , N'-pentamethyldiethylenetriamine, and the like.

The purified osmosis membrane of the present invention satisfies a flow rate of 3 gfd or more at the induction solution 2M NaCl or the same level of osmotic pressure and despreading of the NaCl inducing solution at 9 μs / cm · min or less, and is suitable for high concentration of seawater.

In the positive osmosis membrane of the present invention, the properties of the membrane can be controlled according to the porosity and hydrophilicity of the nonwoven fabric. Preferably, the membrane has an air permeation rate of 2 cc / cm 2 sec or more and has an average pore size of 1 to 600 μm in the nonwoven fabric , Giving a high water permeability. At this time, the thickness of the nonwoven fabric is preferably 20 to 150 mu m.

In the positive osmosis membrane of the present invention, the polymer layer can minimize the permeation resistance with water by controlling the material and structure. Preferred materials include polyacrylonitrile, polyacrylic acid, polyacrylate, polymethyl methacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, Polysulfone, polyethylene oxide and polyvinyl acetate, or copolymers thereof.

A synthetic polymer which is copolymerized with a hydrophilic compound having any one hydrophilic functional group selected from a hydroxyl group, a sulfonated group, a carbonyl group, an acetate group and an ester group may be used for the polyacrylonitrile. At this time, the thickness of the polymer layer is 30 to 250 탆.

The present invention relates to a process for producing the high flow rate positive osmosis membrane, which comprises the steps of 1) preparing a support for a nonwoven fabric-reinforced osmosis membrane by forming a polymer layer by doping a solution containing a polymer on a nonwoven fabric, 2) Or an alkylated aliphatic amine in an aqueous solution further containing 0.01 to 2% by weight of a polyamine salt compound as a water-soluble additive and then pressing to form an aqueous solution layer on the surface of the support, and 3) And a step of forming a polyamide layer by interfacial polymerization between the compounds by contacting an organic halide compound-containing organic solution.

The polymer-containing solution in step 1) contains 10 to 25% by weight of a polymer, and the polymer is selected from the group consisting of polyacrylonitrile, polyacrylic acid, polyacrylate, polymethyl methacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate , Polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, sulfonated polysulfone, polyethylene oxide, and polyvinyl acetate, or copolymers thereof are preferably used.

As the polymer, a synthetic polymer copolymerized with a hydrophilic compound having any one of hydrophilic functional groups selected from a hydroxyl group, a sulfonated group, a carbonyl group, an acetate group and an ester group may be used for the polyacrylonitrile.

The polyamine salt compound to be added in step 2) is preferably a tertiary polyamine salt compound prepared from a reaction molar ratio of tertiary polyamine and strong acid of 0.5-2: 1. To increase the flow rate of the film, a polar solvent is added to the polyamine salt compound . ≪ / RTI >

According to the present invention, it is possible to provide a purified osmosis membrane and a method of manufacturing the same, which are suitable for a high concentration of seawater desalination capable of minimizing the high flow rate and reverse diffusion of the solute of the inducing solution.

The high flow rate positive osmosis membrane of the present invention is a composite membrane structure in which a polyamide layer is formed on a support made of a polymer layer having a low pore bending degree in a nonwoven fabric having excellent air permeability and further contains a water soluble additive in forming the polyamide layer, The flow rate can be improved by forming the pores of the membrane.

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

The present invention relates to a composite membrane structure in which a polyamide layer is formed on a support made of a nonwoven fabric and a polymer layer, wherein the polyamide layer comprises 0.01 to 2 wt% of a polyamine salt compound in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine And an organic solution layer containing a polyfunctional acid halide compound are formed by interfacial polymerization.

The purified osmosis membrane of the present invention has a flow rate of 3 gfd or more, more preferably 3 to 20 gfd at the same level of 2 M NaCl or the same level of osmotic pressure and at the same time, And can be applied to seawater desalination.

In addition, the positive osmosis membrane of the present invention having a composite membrane structure in which a polyamide layer is formed can remove monovalent ions that are difficult to remove in a single membrane structure, thereby securing a high salt rejection rate.

That is, the positive osmosis membrane of the present invention has a polymer layer formed on a nonwoven fabric having a high air permeation amount so that water can flow smoothly into the induction solution in the raw water portion and has high water permeability in the osmotic direction, . Also, a polyamide formed by interfacial polymerization of an aqueous solution layer containing 0.01 to 2% by weight of a polyamine salt compound as a water-soluble additive in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine on the support and a polyfunctional acid halide- Layers are stacked, it is possible to maintain the high osmotic pressure by preventing the diffusion of the solute of the inducing solution in the chemical resistance and reverse osmosis direction of the membrane, thereby providing a membrane structure suitable for high concentration of seawater.

Hereinafter, the positive osmosis membrane of the present invention will be described for each constitution.

1) Nonwoven

In the positive osmosis membrane of the present invention, the nonwoven fabric serves as a support for the membrane.

Preferred materials that may be used in the nonwoven of the present invention include synthetic fibers selected from the group consisting of polyester, polypropylene, nylon and polyethylene; Or cellulose-based pulp. These nonwoven fabrics can control the physical properties of the membrane according to porosity and hydrophilicity of the material.

The porosity of the nonwoven fabric may be any as long as it satisfies an air permeation rate of 2 cc / cm 2 sec sec or more, more preferably 10 cc / cm 2 sec sec or more and less than 1,000 cc / If the material satisfies the air permeation amount, it can be used without any particular limitation. At this time, when the average pore size of the nonwoven fabric of the present invention is preferably 1 to 600 탆, and more preferably 300 탆 or more, smooth permeation of water and water permeability required for the positive osmosis membrane can be improved.

The thickness of the nonwoven fabric of the present invention is preferably from 20 to 150 mu m, and if it is less than 20 mu m, the strength and support of the entire film are insufficient. If it exceeds 150 mu m, the flow rate is decreased.

2) The polymer layer

In the positive osmosis membrane of the present invention, the polymer layer is used by adjusting the material and structure in order to minimize the permeation resistance with water.

Preferred are polyacrylonitrile, polyacrylic acid, polyacrylate, polymethylmethacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, sulfonated polysulfone , Polyethylene oxide and polyvinyl acetate, or copolymers thereof may be used.

Another preferred polymer is a synthetic polymer in which polyacrylonitrile (PAN) and a polymer having a hydrophilic functional group are copolymerized. At this time, the polymer having hydrophilic functional group should be a polymer compatible with polyacrylonitrile, and is a polymer having any one functional group selected from a hydroxyl group, a sulfonated group, a carbonyl group, an acetate group and an ester group. Preferable examples of the synthetic polymer include PAN-vinyl acetate copolymer, PAN-acrylic ester copolymer, and the like.

Further, since hydrophilicity increases upon treatment with base (OH) to the above-described polymer, the polymer used in the present invention includes a hydrophilic-treated compound for the polymer. The thickness of the polymer layer is preferably as small as possible in order to increase the flow rate, and a preferable thickness thereof is 30 to 250 탆.

3) Polyamide layer

In the positive osmosis membrane according to the present invention, the polyamide layer is formed on an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine on an aqueous solution containing 0.01 to 2% by weight of a polyamine salt as a water-soluble additive on a support made of the non- , And an organic solution of a polyfunctional acid halide compound in contact with each other.

Generally, the polyamide layer comprises an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine selected from metaphenyldiamine, paraphenyldiamine, orthophenyldiamine, piperazine or alkylated piperidine, and an aqueous solution containing a polyfunctional acyl halide, Is formed by interfacial polymerization between the compounds by contacting an organic solution of a polyfunctional acid halide compound selected from anhydrides, sulfonyl halides, polyfunctional sulfonyl halides or polyfunctional isocyanates. At this time, since the polyamine salt is further contained in the amine-containing aqueous solution, the present invention is advantageous in forming the pores of the polyamide layer and improves the flow rate thereof and acts as an acid acceptor of the acid generated during the interfacial reaction, . The content of the polyamine salt compound is preferably from 0.01 to 2% by weight, and if the content is less than 0.01% by weight, pore formation for improving the flow rate is insufficient, while if it exceeds 2% by weight, Undesirably causing defects in the layer.

More preferably, the polyamine salt is a tertiary polyamine salt compound prepared from a reaction molar ratio of tertiary polyamine and strong acid of 0.5 to 2: 1. When the reaction molar ratio of the tertiary polyamine salt is less than 0.5, And if the reaction molar ratio exceeds 2, the polyamine remaining after the reaction affects the polyamide chain formation, which is not preferable.

Examples of the strong acid include, but are not limited to, aromatic sulphonic acid, aliphatic sulphonic acid, cycloaliphatic sulphonic acid, trifluoroacetic acid, nitric acid, hydrochloric acid and sulfonic acid. One or a mixture thereof.

The polyamine used in the present invention is a compound in which two or more monovalent or divalent amine groups are bonded to each other, and aliphatic polyamines or aromatic polyamines may be used. More preferred are tertiary polyamines such as 1,4-diazabicyclo [ 2,2,2] octane (DABCO), 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU), 1,5- diazabicyclo [ N, N ', N'-tetramethylethylenediamine, N, N, N'-tetramethylethylenediamine, N, N ', N'-tetramethyl-1,3-butanediamine, N, N, N', N'- N, N ', N'-tetramethyl-1,6-hexanediamine (TMHD), 1,1,3,3-tetramethylguanidine (TMGU) and N, N , N ', N'-pentamethyldiethylenetriamine, and the like.

Further, for the purpose of increasing the flow rate of the produced membrane, 0.01 to 2% by weight of one or more polar solvents may be further added to the polyfunctional amine aqueous solution in addition to the polyamine salt compound. The polar solvent may be an ethylene glycol derivative, a propylene glycol derivative, a 1,3-propanediol derivative, a sulfoxide derivative, a sulfone derivative, a nitrile derivative, a ketone derivative, a urea derivative or a mixture thereof.

As described above, since the positive osmosis membrane of the composite membrane structure of the present invention is provided with the polyamide layer, not only the chemical resistance and the pH stability are secured, but also the monovalent ions which are difficult to remove in the single membrane structure are removed It is possible to secure a high salt rejection rate. Therefore, the positive osmosis membrane of the present invention optimizes the physical properties required in the forward osmosis system, and is therefore suitable for high concentration of sea water bath.

The present invention provides a method for producing a high flow rate positive osmosis membrane having the composite membrane structure. More specifically,

1) preparing a support of a nonwoven fabric-reinforced positive osmosis membrane by forming a polymer layer by doping a polymer-containing solution on a nonwoven fabric,

2) a step of immersing the support in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine in an aqueous solution further containing 0.01 to 2% by weight of a polyamine salt compound as a water-soluble additive, and then pressing to form an aqueous solution layer on the surface of the support;

3) contacting the aqueous solution layer with an organic solution containing a polyfunctional acid halide compound to form a polyamide layer by interfacial polymerization between the compounds.

The above step 1) is designed so that the forward osmosis membrane of the present invention has a high water permeability in the osmotic direction, allowing water to flow into the induction solution at the raw water portion well. At this time, the nonwoven fabric smoothly flows the water by the supporting role of the membrane and the high porosity. The material usable for the nonwoven fabric can be used without limitation as long as it exhibits a porosity that satisfies an air permeation rate of 2 cc / cm 2 sec sec or more. More preferably, the air permeation amount is in the range of 10 cc / cm 2 sec or more and less than 1,000 cc / cm 2 sec or less. At this time, the nonwoven fabric can be produced by any conventionally known production method without any particular limitation.

In order to achieve the design objective of step 1), a polymer-containing solution is doped on the nonwoven fabric to form a polymer layer. At this time, the polymer layer is used to form materials and structures for smooth flow of water and high water permeability in the direction of osmosis.

Preferred examples include polyacrylonitrile, polyacrylic acid, polyacrylate, polymethylmethacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, sulfonated poly Sulfone, polyethylene oxide, and polyvinyl acetate, or copolymers thereof.

Further, a synthetic polymer in which a hydrophilic compound having a hydrophilic functional group is copolymerized with the polymer or a polymer synthesized with the polymer can be used.

In addition, examples of the polymer described above include a compound subjected to a hydrophilic treatment process capable of increasing the hydrophilicity due to the base treatment.

An example of the specific polymer described above is the same as that described for the positive osmosis membrane, and thus a detailed description thereof will be omitted.

In this step 1), the polymer content in the polymer-containing solution is 10 to 25% by weight, more preferably 13 to 20% by weight. If the polymer content is less than 10% by weight, pores are formed to a large extent to cause defects in the coating layer during formation of the polyamide layer, thereby deteriorating the ability to remove salts. On the other hand, if the polymer content exceeds 25% The viscosity may become excessively high, so that the film formation may be difficult or the polyamide layer may not be formed uniformly, and the ability to separate the film may be deteriorated.

Further, the thickness of the polymer layer is preferably as small as possible in order to increase the flow rate, and the thickness of the polymer layer of the present invention satisfies 30 to 250 탆.

In the production process of the present invention, step 2) is carried out in such a manner that the support consisting of the nonwoven fabric and the polymer layer formed in step 1) is selected from metaphenylenediamine, paraphenylenediamine, orthophenylenediamine, piperazine or alkylated piperidine The polyamine salt compound is further contained in the aqueous solution in an amount of 0.01 to 2% by weight to improve pore formation of the polyamide layer to improve the flow rate of the polyamide layer , Promoting interfacial reaction. At this time, the polyamine salt compound is a tertiary polyamine salt compound prepared from the reaction of a tertiary polyamine with a strong acid.

For the purpose of increasing the flow rate of the produced membrane, 0.01 to 2% by weight of one or more polar solvents may be further added to the amine-containing aqueous solution in addition to the polyamine salt compound.

In the production method of the present invention, Step 3) is a step of contacting the aqueous solution layer prepared in Step 2) with an organic solution containing a polyfunctional acid halide compound to form a polyamide layer by interfacial polymerization between the compounds.

Through the manufacturing method of the present invention, it is possible to produce a composite membrane structure separation membrane in which a polyamide layer is laminated on a support made of a nonwoven fabric reinforcing polymer layer serving as a porous support. Since the separation membrane of this composite membrane structure is designed so that water can flow smoothly into the induction solution in the raw water portion by the support made of the polymer layer in the nonwoven fabric having a high air permeation amount and high water permeability in the osmotic direction, Suitable.

Further, by stacking the polyamide layer on the support, it is possible to prevent the diffusion of the solute of the inducing solution in the chemical resistance and the reverse osmosis direction of the membrane, so that the high osmotic pressure can be maintained, An osmotic membrane can be produced.

Further, by producing the composite membrane structure having a polyamide layer in the form of a film through the production method of the present invention, the limitation of the single membrane structure, which is difficult to remove a small salt such as monovalent ions, Ions can be removed. That is, a high salt rejection rate can be achieved.

Thus, the method for producing a positive osmosis membrane of the present invention can control the physical properties of a membrane according to the porosity and hydrophilicity of the nonwoven fabric, and by forming the polymer layer having high pores and low pores with optimum conditions on the nonwoven fabric, It is possible to design the water to have a high water permeability in the direction of osmosis by allowing water to flow into the inducing solution from the raw water well. Further, when a polyamide layer is formed on the polymer layer, a water-soluble additive may be further added to the aqueous solution to prevent the dissolution of the solute in the inducing solution at the same time as the flow rate is increased.

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

The following examples illustrate the present invention, but the scope of the present invention is not limited to the following examples.

≪ Example 1 >

(Nonwoven fabric 1) having a pore size of 6.3 cc / cm < 2 > sec and an average pore size of 7.5 mu m was immersed in a dimethylformamide solution containing 17.5 wt% of polyacrylonitrile (PAN) Was cast to a thickness of 50 +/- 10 mu m and immediately solidified by immersing it in a distilled water bath at room temperature and sufficiently washed with water to prepare a positive osmosis membrane separator support made of nonwoven fabric reinforced polyacrylonitrile (PAN). The prepared osmotic membrane separation membrane support was confirmed to have low bending property due to finger-like pores. After that, it was kept in ultrapure water for one day to extract the solvent. The solvent-extracted support was dissolved in an aqueous solution containing 2% by weight of meta-phenylenediamine (MPD) and 0.1% by weight of N, N, N ', N'-tetramethyl-1,6-hexadiamine (TMHD) For 20 seconds, and then the surface water layer was removed by a pressing method. The substrate was brought into interfacial contact with an ISOPAR solvent (Exxon Corp.) for 40 seconds in an organic solution containing 0.1% by weight trimesoyl chloride (TMC), and then a polyamide layer was formed by the polymerization reaction between the compounds, Lt; / RTI > The resulting osmosis membrane was immersed in a basic aqueous solution such as 0.2% by weight sodium carbonate at room temperature for 2 hours and then washed with distilled water to prepare a membrane having a composite membrane structure.

≪ Examples 2 to 6 &

The procedure of Example 1 was repeated except that the concentration of N, N, N ', N'-tetramethyl-1,6-hexadiamine (TMHD) as an aqueous solution additive was changed in Example 1 A composite membrane structure was fabricated.

≪ Examples 7 to 10 &

Except that toluene sulfonic acid (TSA) was added to N, N, N ', N'-tetramethyl-1,6-hexadiamine (TMHD) as an aqueous solution additive for the aqueous solution additive in Example 4 , A composite osmosis membrane having a composite membrane structure was prepared in the same manner as in Example 1.

≪ Examples 11 to 12 &

Except that a polyacrylonitrile-vinyl acetate copolymer (P-CO-PAN) was used instead of polyacrylonitrile (PAN) as the polymer layer material and the concentration was varied, 1, a composite membrane membrane was prepared.

≪ Examples 13 to 14 &

A nonwoven fabric (nonwoven fabric 2) of polyester having a pore size of 10 cc / cm 2 ㆍ sec or more in air permeability and an average pore size of 300 탆 or more was used and a polyacrylonitrile-vinyl acetate copolymer (P-CO-PAN ) Was prepared in the same manner as in Example 11, except that the concentration of the complex membrane was changed.

≪ Comparative Example 1 &

A composite osmosis membrane having a composite membrane structure was prepared in the same manner as in Example 1, except that the polyamide layer was formed without using an aqueous solution additive in the membrane structure of Example 1.

≪ Comparative Example 2 &

Except that a polysulfone was used as a polymer layer on a polyester nonwoven fabric (nonwoven fabric 3) having air permeability of 2 cc / cm 2 sec sec or less and having characteristics of an average pore size of 5 탆 or less , A composite membrane-structured positive osmosis membrane was prepared in the same manner as in Example 11.

≪ Comparative Example 3 &

A separator made of cellulose triacetate alone was prepared.

≪ Experimental Example 1 >

The polyamide layer is in contact with the raw water and the nonwoven fabric is placed at a position where it contacts the induction solution. The flow of water in the direction of the inducing solution from the raw water is induced, The amount of water per hour was measured by measuring the weight before and after. At this time, 2 M of sodium chloride (NaCl) was used as the induction solution, and ultrapure water (osmotic pressure of about 100 atm) was used as raw water.

≪ Experimental Example 2 >

(2M NaCl) was used as the induction solution and the conductivity (TDS) of salts introduced into the raw water side (ultrapure water) in the induction solution was measured using ultrapure water (osmotic pressure of about 100 atm) ) Was measured by using a conductivity meter to measure the degree of despreading in units of the change in the conductivity per minute.

As shown in Table 1 below, the measurement results of the physical properties of membranes evaluated as the forward osmosis mode under the induction solution conditions of 2M NaCl / ultrapure water are shown .

As can be seen in Table 1, it was confirmed that the flow rate of the positive osmosis membrane (Comparative Example 1) in which the polyamide layer was formed without an additive in the aqueous solution was significantly lower than that of the membrane prepared in the Example. However, the despersion change of the salt was advantageous compared to the separator composed of cellulose triacetate (CTA) alone (Comparative Example 3).

In addition, as a result of measuring physical properties of a separator (Comparative Example 2) having a polyamide layer formed on a polysulfone porous support as a support structure of a conventional reverse osmosis membrane, excellent salt back diffusion inhibition effect was confirmed, but the flow rate was remarkably low, It can not be used as a driven osmosis membrane.

On the other hand, in the case of the positive osmosis membrane prepared in the embodiment of the present invention, the addition of the additive to the aqueous phase during the formation of the polyamide layer inhibits the diffusion of the excellent salt and simultaneously confirms the flow rate improvement result. Also, it was confirmed that salt diffusion inhibition and flow rate of the induction solution can be controlled according to the polymer constituting the support and the content thereof according to the nonwoven fabric.

Thus, the positive osmosis membrane prepared in the example of the present invention is excellent in salt diffusion inhibition (salt diffusion: 9.9 μS / cm · min) compared with the membrane made of cellulose triacetate (salt diffusion: 9.12 μs / Mu s / cm < / RTI > or less), thereby minimizing the diffusion of the solute in the induction solution.

Further, as shown in Examples 11 and 14, when the nonwoven fabric 2 (air permeation amount of 10 cc / cm ² sec or more) having a large degree of porosity was applied in the same film configuration except that a nonwoven fabric having a difference in porosity was used , The flow rate was improved, and at the same time, the excellent salt diffusion inhibition performance was confirmed.

As described above,

First, the present invention provides a high flow rate positive osmosis membrane having a composite membrane structure in which a polyamide layer is formed on a support made of a polymer layer having a low pore bending degree in a nonwoven fabric having excellent air permeability.

Since the high flow rate positive osmosis membrane of the present invention has a polymer layer having a low pore bending degree (finger-like structure) in the nonwoven fabric having excellent air permeation amount and low solvent migration resistance, The inflow is made good, and the high water permeability and flow rate in the osmotic direction are improved. Further, by further containing a water-soluble additive at the time of forming the polyamide layer, it is possible to improve not only the salt rejection rate, the chemical resistance and the pH stability due to the inherent polyamide layer but also the flow rate of the membrane and the reverse solution Can be prevented.

Secondly, according to the method for producing a positive osmosis membrane of the present invention, by forming a polymer layer having high porosity and low pore bending on the nonwoven fabric in an optimum condition, water can be easily introduced into the induction solution from the raw water portion through the membrane, It can be designed to have a high water permeability in the direction of the water. In addition, the polyamide layer formation process has been improved to prevent reverse diffusion of high flux and solute in the inducing solution.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

A nonwoven fabric having an air permeation amount of not less than 2 cc /
On the polymer layer of a support having polymer layers having finger-like pores having a low degree of curvature,
A polyamide layer formed by interfacial polymerization of an aqueous solution layer containing 0.01 to 2 wt% of a polyamine salt compound and an organic solution layer containing a polyfunctional acid halide compound in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine; , The inductive solution 2M NaCl or the osmotic pressure of the same level, and the despreading of the NaCl-derived solution satisfies the physical property of 9 / / cm min min or less. The high flow rate osmosis membrane according to claim 1, wherein the polyamine salt compound is a tertiary polyamine salt compound prepared from a reaction molar ratio of tertiary polyamine and strong acid of 0.5 to 2: 1. The method of claim 2, wherein the tertiary polyamine is 1,4-diazabicyclo [2,2,2] octane (DABCO), 1,8-diazabicyclo [5,4,0] undec- (DBU), 1,5-diazabicyclo [4,3,0] non-5-ene (DBN), 1,4-dimethylpiperazine, 4- [2- (dimethylamino) ethyl] N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethyl-1,3-butanediamine, Butane diamine (TMBD), N, N, N ', N'-tetramethyl-1,3-propanediamine, N, N, N', N'-tetramethyl-1,6- hexanediamine , 1,3,3-tetramethylguanidine (TMGU), and N, N, N ', N'-pentamethyldiethylenetriamine. delete delete The high-flow-rate positive osmosis membrane according to claim 1, wherein the nonwoven fabric has an average pore size of 1 to 600 μm. The high-flow-rate positive osmosis membrane according to claim 1, wherein the nonwoven fabric has a thickness of 20 to 150 μm. The method of claim 1, wherein the polymer layer is selected from the group consisting of polyacrylonitrile, polyacrylic acid, polyacrylate, polymethylmethacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene Wherein the membrane is made of a single component or a copolymer thereof selected from the group consisting of glycols, sulfonated polysulfone, polyethylene oxide and polyvinyl acetate. delete 1) A polymer-containing solution is doped on a nonwoven fabric having an air permeation rate of 2 cc / cm 2 ㆍ sec or more to form a polymer layer having finger-like pores having a low degree of curvature to prepare a support of the nonwoven fabric- fair,
2) a step of immersing the support in an aqueous solution containing a polyfunctional amine or an alkylated aliphatic amine in an aqueous solution further containing 0.01 to 2% by weight of a polyamine salt compound as a water-soluble additive, and then pressing to form an aqueous solution layer on the surface of the support;
3) contacting the aqueous solution layer with an organic solution containing a polyfunctional acid halide compound to form a polyamide layer by interfacial polymerization between the compounds. delete The method of claim 10, wherein the polymer is selected from the group consisting of polyacrylonitrile, polyacrylic acid, polyacrylate, polymethylmethacrylate, polyethyleneimide, cellulose acetate, cellulose triacetate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol , Sulfonated polysulfone, polyethylene oxide, and polyvinyl acetate, or a copolymer thereof. ≪ Desc / Clms Page number 19 > delete The method of claim 10, wherein the polyamine salt compound is a tertiary polyamine salt compound prepared from a reaction molar ratio of tertiary polyamine and strong acid of 0.5 to 2: 1. 11. The method according to claim 10, wherein as the water-soluble additive, the polyamine salt compound is a compound selected from the group consisting of an ethylene glycol derivative, a propylene glycol derivative, a 1,3-propanediol derivative, a sulfoxide derivative, a sulfone derivative, a nitrile derivative, a ketone derivative and a urea derivative Wherein the polar solvent further comprises at least one compound selected from the group consisting of a polar solvent and a polar solvent.