KR20160071857A - Method for manufacturing water treatment separating membrane and water treatment separating membrane manufactured by the same - Google Patents

Abstract

The present invention relates to a method for producing a water treatment separation membrane and a water treatment separation membrane produced using the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a water treatment membrane, and a water treatment membrane produced by using the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a method for producing a water treatment separation membrane and a water treatment separation membrane produced using the same.

The phenomenon that the solvent moves between the two solutions separated by the semi-permeable membrane through the membrane from the solution with a low solute concentration to the solution with a high solute concentration is called osmotic phenomenon. The pressure acting on the solution side Is called osmotic pressure. However, when an external pressure higher than osmotic pressure is applied, the solvent moves toward the solution having a low solute concentration. This phenomenon is called reverse osmosis. By using the reverse osmosis principle, it is possible to separate various salts or organic substances through the semipermeable membrane using the pressure gradient as a driving force. Water treatment membranes using this reverse osmosis phenomenon have been used to supply water for domestic, architectural and industrial purposes by separating substances at a molecular level and removing salts from brine or seawater.

Typical examples of such a water treatment separation membrane include a polyamide-based water treatment separation membrane, and a polyamide-based water treatment separation membrane is produced by a method of forming a polyamide active layer on a microporous layer support. More specifically, Forming a microporous support by immersing the microporous support in an aqueous solution of m-Phenylene Diamine (mPD) to form an mPD layer, and then adding tri- mesoyl chloride, TMC) in an organic solvent so that the mPD layer is brought into contact with the TMC to perform interfacial polymerization, thereby forming a polyamide layer.

However, there is a problem in that the performance of the water treatment separation membrane is deteriorated due to a decrease in the salt removal rate due to a decrease in the binding force between the polyamide layer and the microporous support over time.

Korean Patent Publication No. 2014-0005489

The present invention provides a method for producing a water treatment separation membrane capable of solving the above problems and a water treatment separation membrane produced using the same.

An embodiment of the present invention includes a method of forming a porous polymer layer by casting a polymer solution on a surface of a porous support; Immersing the porous polymer layer in an amine aqueous solution containing an amine compound to form a layer containing an amine aqueous solution on the porous polymer layer; Forming a vacuum atmosphere on a side opposite to the one surface of the porous support on which the porous polymer layer is formed and removing an excess aqueous amine solution in the layer containing the amine aqueous solution using an air knife; And immersing the layer containing the amine aqueous solution in an organic solution containing a compound containing an acyl halide group to form an active layer.

Another embodiment of the present invention provides a water treatment separation membrane that is manufactured by the above-described method for producing a water treatment separation membrane.

One embodiment of the present disclosure provides a water treatment module comprising at least one water treatment membrane as described above.

Another embodiment of the present disclosure provides a water treatment apparatus comprising at least one of the above-described water treatment modules.

According to the embodiments described herein, before the active layer is formed by dipping in an organic solution containing an amine aqueous solution and an acyl halide group, an excess aqueous amine solution is added in the direction of the plane of the layer containing the amine aqueous solution The membrane is removed with an air knife, and at the same time, vacuum suction is carried out at an appropriate pressure on the opposite side of the surface on which the porous polymer layer is formed. Thus, a high performance separation membrane with a small performance deviation can be obtained.

In addition, since it includes a step of pulling at a suitable pressure during the water treatment separation membrane production process, the adhesion between the active layer and the porous support is improved.

1 is a TEM (transmission electron microscopy) image of a water treatment separation membrane according to an embodiment of the present invention.
2 is a TEM image of a water treatment separation membrane according to the prior art.

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

An embodiment of the present invention includes a method of forming a porous polymer layer by casting a polymer solution on a surface of a porous support; Immersing the porous polymer layer in an amine aqueous solution containing an amine compound to form a layer containing an amine aqueous solution on the porous polymer layer; Forming a vacuum atmosphere on a side opposite to the one surface of the porous support on which the porous polymer layer is formed and removing an excess aqueous amine solution in the layer containing the amine aqueous solution using an air knife; And immersing the layer containing the amine aqueous solution in an organic solution containing a compound containing an acyl halide group to form an active layer.

In this specification, the material of the porous support may be a polymer, and is not limited as long as it is in the form of a nonwoven fabric. For example, the porous support may be a polyester nonwoven fabric to enhance the mechanical strength of the membrane.

In this specification, casting refers to a solution casting method. Specifically, it means a method of dissolving a polymer substance in a solvent, developing it on a smooth surface having no adhesion, and then evaporating the solvent. For example, drop casting, spin coating, dip coating, and the like can be mentioned. However, the present invention is not limited thereto, and the solvent may be added during the evaporation process, But is not limited thereto.

In this specification, a vacuum atmosphere is formed on the side opposite to the one surface of the porous substrate on which the porous polymer layer is formed. The porous substrate is fixed with a vacuum pump at about 30 psi using a flat vacuum pump connected to a rotary pump But is not limited to, removing the excess amine aqueous solution by pulling the air by blowing air at about 9 psi on a flat air knife connected to a rotary pump.

When excess amine aqueous solution is removed by using an air knife, excess amine aqueous solution is pulled in the direction of the support at a suitable pressure by using a vacuum pump, so that it is possible to manufacture a separation membrane having small deviation per membrane part and excellent performance.

Further, since an appropriate pressure is applied in the direction of the support, the adhesion between the support and the active layer is improved.

The step of removing the excess amine aqueous solution in the layer containing the amine aqueous solution may include removing the aqueous amine solution in the layer containing the amine aqueous solution in an amount of more than 70% by weight based on 100% by weight of the entire water treatment separation membrane, To remove the amine aqueous solution in the layer comprising the amine aqueous solution of greater than 65 wt%, more specifically greater than 60 wt%.

If the excess amine aqueous solution is not removed, the adhesion between the support and the active layer is deteriorated because polymerization is carried out in a state where a large amount of water remains in the interfacial polymerization with the organic solution.

In this specification, the organic solution means a solution containing a material capable of forming a polyamide at an interface with the amine aqueous solution. That is, the organic solution in this specification may include an acyl halide group and a solvent.

The solvent of the organic solution may be a nonpolar solution, but is not limited thereto, and may be, for example, an organic solvent such as hexane, cyclohexane, heptane or the like, or Isol-C (SKC Corp.).

In yet another embodiment of the present disclosure, the vacuum pressure for forming the vacuum atmosphere may be in the range of 20 psi to 50 psi, specifically 25 psi to 45 psi, more specifically 25 psi to 40 psi.

When the vacuum pressure is within the above range, excessive excess aqueous amine solution remains to prevent the interfacial polymerization from being formed with high adhesion to the support, and excessive crosslinking due to the excess amine can be prevented . Also, it is possible to prevent the phenomenon that the amine monomer enters too deeply into the support, thereby preventing the phenomenon that the polyamide membrane is deeply formed inside the support to reduce the permeation flow rate.

In the embodiment of the present invention, the air knife may be provided on the opposite side of one surface of the layer containing the amine aqueous solution, which is provided close to the porous polymer layer. For example, in a direction perpendicular to the layer containing the amine aqueous solution.

In another embodiment of the present invention, the step of forming a vacuum atmosphere on the side opposite to the one surface of the porous support on which the porous polymer layer is formed and removing the excess amine aqueous solution using the air knife may be performed for 2 to 10 seconds , Specifically 3 seconds to 5 seconds, more specifically 3 seconds, but is not limited thereto. For example, the vacuum suction may be performed for a time period using the air knife, or may be performed before using the air knife.

If the step of removing excess amine aqueous solution by using the air knife is performed within 3 seconds to 10 seconds, an excess of excess amine aqueous solution can be effectively removed, and an appropriate monomer required for interfacial polymerization remains, It is possible to produce a water treatment separation membrane having It is also efficient in terms of process.

In another embodiment of the present disclosure, the wind pressure of the air knife can be 5 psi to 20 psi, specifically 5 psi to 15 psi, more specifically 8 psi to 15 psi, but is not limited thereto.

When the wind pressure of the air knife is within the above range, the excess excess amine aqueous solution can be effectively removed, and the process can be efficiently performed. Also, suitable monomers required for interfacial polymerization remain, There is an advantage.

The definition of the porous support is as described above, and the thickness of the porous support may be 60 탆 to 120 탆, but may be 90 탆 to 120 탆, and may be adjusted as needed. The pore size of the porous support is preferably 1 nm to 500 nm, but is not limited thereto. When the pore size is more than 500 nm, a solution for forming a polymer solution or an active layer, which will be described later, permeates between the pores, making it difficult to form a uniform structure. When the pore size is less than 1 nm, It is also difficult to form a uniform structure.

According to one embodiment of the present invention, the active layer includes a polyamide-based compound, and the polyamide-based compound may be formed by interfacial polymerization of an amine-based compound and a compound containing an acyl halide group of the organic solution , But is not limited thereto. For example, the organic solvent may be formed by dropping the organic solution onto the layer containing the amine aqueous solution from which the excess amine aqueous solution has been removed.

According to another embodiment of the present invention, the polymer solution may include at least one selected from the group consisting of polysulfone, polyethersulfone, polyethyleneoxide, polyimide, polyetherimide, polyetherketone polypropylene, polymethylpentene, polymethylchloride, and polyvinylidene fluoride. However, the present invention is not limited thereto, and may include, for example, at least one selected from the group consisting of polyetherketone, polypropylene, polymethylpentene, polymethylchloride and polyvinylidene fluoride. It is not. For example, the polymer solution may include polysulfone.

In another embodiment of the present disclosure, the amine aqueous solution is selected from the group consisting of meta-phenylenediamine (mPD), p-phenylenediamine, 1,3,6-benzenetriamine, But are not limited to, at least one selected from the group consisting of 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylenediamine and pyrazine. For example, the amine aqueous solution preferably contains mPD.

The amine aqueous solution may include at least one selected from water and isopropyl alcohol (IPA) as a solvent, but is not limited thereto.

In one embodiment of the present disclosure, the compound comprising amine groups relative to 100% of the total weight of the amine aqueous solution comprises 1 wt% to 10 wt%, specifically 2 wt% to 8 wt%, more specifically 2 wt% to 6 wt% %, But is not limited thereto.

When the compound containing the amine group is included within the above range, cross-linking may occur appropriately and the salt removal ratio and the permeation flow rate may be effective.

As a method of forming the amine aqueous solution layer on the porous support, bar coating, slot die coating, dipping, coating or coating method is usually used, but the present invention is not limited thereto.

In another embodiment of the present disclosure, the compound comprising the acyl halide group is a compound selected from the group consisting of trimethoyl chloride (TMC), isotaryl chlorite (IPC) and terephthaloyl chloride (TPC) But the present invention is not limited thereto. For example, the compound containing the acyl halide group may include TMC.

In another embodiment of the present invention, the compound containing the acyl halide group in an amount of from 0.1% by weight to 1% by weight, specifically 0.1% by weight to 0.8% by weight, more specifically 0.1% by weight, To 0.5% by weight, but is not limited thereto.

When the compound containing the acyl halide group is included within the above range, it is possible to prepare a water treatment separation membrane having cross-linking appropriately and having excellent salt removal rate and permeation flow rate.

According to another embodiment of the present invention, the step of forming the porous polymer layer may include, but not limited to, casting a polymer solution on one surface of the porous support to a thickness of 20 μm to 50 μm.

When the thickness of the porous polymer layer is within the above range, it has an advantage that it can serve as a support and maximize the performance of the separator active layer by having an appropriate thickness.

In one embodiment of the present invention, the step of immersing the layer containing the amine aqueous solution in the organic solution may further include drying the active layer, but the present invention is not limited thereto.

For example, the step of drying the active layer may be performed at a temperature of 60 ° C to 120 ° C, but is not limited thereto, and may be preferably carried out at a temperature of 90 ° C to 120 ° C.

According to another embodiment of the present invention, the method may further include washing the active layer after the step of drying, but the present invention is not limited thereto. For example, it may further include drying after the washing step.

According to one embodiment of the present invention, there is provided a water treatment separation membrane produced by the above-described method for producing a water treatment separation membrane.

According to another embodiment of the present disclosure, the water treatment separator may have a thickness of 110 mu m to 170 mu m, but is not limited thereto.

According to one embodiment of the present disclosure, there is provided a water treatment module including at least one of the above-described water treatment membranes.

According to another embodiment of the present invention, there is provided a water treatment apparatus including at least one of the above-described water treatment modules.

Hereinafter, the present invention will be described in detail by way of examples to illustrate the present invention. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the above-described embodiments. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art.

Manufacturing method of water treatment separator

[Example 1]

In the present invention, polysulfone is cast on a 95 to 100 탆 porous support made of polyester to be used as a reverse osmosis membrane.

To cast the polysulfone, 18 wt% polysulfone solid was added to DMF (N, N-dimetnylformamide) solution and dissolved at 80 ~ 85 ℃ for more than 12 hours. When homogeneous liquid phase was obtained, 45 ~ 50 0.0 > m. ≪ / RTI >

The prepared porous polysulfone support was immersed in an aqueous solution containing 2 wt% mPD (m-Phenylenediamine) for 2 minutes, then vacuum pressure was pulled to 10 psi and the excess aqueous solution on the support was removed by using an air knife And then dried at room temperature for 1 minute.

Subsequently, the coated substrate was immersed in a solution containing 0.1 wt% TMC (1,3,5-benzenetricarbonyl trichloride) in an Isol C solvent (SKC Corp.) for 1 minute, and then dried at 60 ° C And dried in an oven for 10 minutes.

Thereafter, the separator was washed with a 0.2 wt% aqueous sodium carbonate solution at room temperature for 2 hours or more, and then washed with distilled water to prepare a polyamide membrane having a thickness of 200 μm to obtain a separator.

[Example 2]

A separation membrane was prepared in the same manner as in Example 1, except that the vacuum pressure of Example 1 was treated at 30 psi.

[Example 3]

A separation membrane was prepared in the same manner as in Example 1, except that the vacuum pressure of Example 1 was treated at 50 psi.

 [Comparative Example 1]

A separation membrane was prepared in the same manner as in Example 1, except that the mPD aqueous solution was removed using vacuum pressure and air knife in the process of producing the polyamide membrane.

Performance Evaluation of Water Treatment Membrane

The initial salt removal rate and the initial permeate flow rate were measured at a flow rate of 4,500 ml / min at a flow rate of 32,000 ppm NaCl at 25 ° C. The reverse osmosis membrane cell apparatus used for the membrane evaluation included a planar permeation cell, a high pressure pump, Respectively.

The structure of the planar type transmissive cell was a cross-flow type with an effective permeation area of 140 cm ² .

After the washed separator was installed in the permeation cell, preliminary operation was performed for about 1 hour by using the third distilled water for stabilization of the evaluation equipment. After that, the equipment was operated for about 1 hour until the pressure and water permeability reached a steady state by replacing with a 32,000 ppm NaCl aqueous solution. The amount of water permeated for a predetermined time was measured to calculate the flow rate. Conductivity meter And the removal rate was calculated by analyzing the salt concentration before and after the permeation.

The membranes according to Examples and Comparative Examples were measured at a pressure of 800 psi in an aqueous solution of NaCl at 32,000 ppm and are shown in Table 1. The unit of permeate flow in Table 1 is GFD (gallon / ft ² day).

division Initial salt removal rate (%) The initial permeate flow (GFD) Example 1 99.45 (0.08) 34.48 (2.19) Example 2 99.68 (0.03) 33.28 (1.26) Example 3 99.55 (0.21) 32.98 (4.12) Comparative Example 1 98.51 (0.18) 32.70 (2.17)

As shown in Table 1, when removing the excess mPD aqueous solution, the excess mPD aqueous solution was removed using an air knife at the front surface, and at the same time, when the mPD aqueous solution was pulled from the support side using a suitable pressure, It is possible to obtain a high-performance separator having a small initial salt removal rate.

In addition, the adhesion between the support and the active layer was confirmed by TEM (Transmission Electron Microscopy). As a result, it was confirmed that the adhesive strength was improved when the support was pulled by the vacuum pressure of a suitable pressure.

FIG. 1 is a TEM image of a water treatment membrane prepared by pulling vacuum pneumatic pressure of 9 psi from a support side, and FIG. 2 is a TEM image when vacuum pressure is not applied on a support side.

FIG. 1 shows a high adhesion between the support and the active layer, whereas FIG. 2 shows a low adhesion between the support and the active layer.

Claims (15)

Casting a polymer solution on one surface of a porous support to form a porous polymer layer;
Immersing the porous polymer layer in an amine aqueous solution containing an amine compound to form a layer containing an amine aqueous solution on the porous polymer layer;
Forming a vacuum atmosphere on a side opposite to the one surface of the porous support on which the porous polymer layer is formed and removing an excess aqueous amine solution in the layer containing the amine aqueous solution using an air knife; And
And immersing the layer containing the amine aqueous solution in an organic solution containing a compound containing an acyl halide group to form an active layer. The method of claim 1, wherein removing the excess amine aqueous solution in the amine aqueous solution comprises removing the amine aqueous solution in the aqueous amine aqueous solution of more than 70% by weight based on 100% Wherein the water-treating separator is a water-treating separator. The method according to claim 1, wherein the vacuum pressure for forming the vacuum atmosphere is 20 psi to 50 psi. The method according to claim 1, wherein the air knife is provided on an opposite side of one surface of the layer including the amine aqueous solution, the air knife being close to the porous polymer layer. The method according to claim 1, wherein the step of forming a vacuum atmosphere on the side opposite to the side where the porous polymer layer is formed and removing the excess amine aqueous solution using an air knife is performed for 2 seconds to 10 seconds Gt; The method according to claim 1, wherein the wind pressure of the air knife is 5 psi to 20 psi. The process for producing a water treatment separation membrane according to claim 1, wherein the active layer comprises a polyamide compound and the polyamide compound is formed by interfacial polymerization of an amine compound and a compound containing an acyl halide group of the organic solution . [Claim 7] The method according to claim 7, wherein the content of the amine compound is 1 wt% to 10 wt% based on 100 wt% of the amine aqueous solution. [Claim 7] The method according to claim 7, wherein the acyl halide group-containing compound is 0.1 wt% to 1 wt% relative to 100 wt% of the total organic solution. The method for producing a water treatment separation membrane according to claim 1, wherein the porous support has a thickness of 60 탆 to 120 탆. The method for producing a water treatment separation membrane according to claim 1, wherein the thickness of the porous polymer layer is 20 to 50 탆. A water treatment separator produced by the manufacturing method according to any one of claims 1 to 11. [12] The water treatment separator according to claim 12, wherein the water treatment separator has a thickness of 110 [mu] m to 170 [mu] m. A water treatment module comprising at least one water treatment membrane of claim 13. A water treatment apparatus comprising at least one water treatment module of claim 14.

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