KR20180036295A - Method for manufacturing water-treatment separation membrane, water-treatment separation membrane manufactured by using the same, and composition for manufacturing water-treatment separation membrane - Google Patents

Abstract

The present invention relates to a method for manufacturing a water treatment separation membrane, and to a composition for the polyamide layer overflow polymerization of the water treatment separation membrane. According to the embodiments described herein, it is possible to provide a high-performance water treatment separator when interfacial polymerization of a polyamide layer on a porous support, using a high-speed coating process, or using an aqueous solution containing an amine compound at a low concentration.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a water treatment membrane, a water treatment membrane manufactured using the same, and a composition for preparing a water treatment membrane. BACKGROUND ART [0002]

The present invention relates to a method for producing a water treatment separation membrane, a water treatment separation membrane produced using the same, and a composition for interfacial polymerization of a polyamide layer of a water treatment separation membrane.

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.

Korean Patent Publication No. 2014-0005489

The present invention relates to a process for producing a water treatment separation membrane capable of providing a high-performance water treatment separation membrane even when a high-speed coating process with a short contact time between an amine compound-containing aqueous solution and a porous support is used, or even when the concentration of an amine compound in an amine compound- It is intended to provide a composition for interfacial polymerization of a polyamide layer of a water treatment separation membrane and a water treatment separation membrane produced thereby.

One embodiment of the present disclosure

Preparing a porous support;

Coating an aqueous solution comprising an amine compound and a water-soluble thickener on the porous support; And

And a step of interfacially polymerizing an aqueous solution containing the amine compound and an organic solution containing an acyl halide compound to form a polyamide active layer on the porous support.

According to the embodiments described herein, it is possible to provide a high-performance water treatment separator when interfacial polymerization of a polyamide layer on a porous support, a high-speed coating process, or an aqueous solution containing a low concentration of an amine compound is used.

1 shows a water treatment separator according to an embodiment of the present invention.

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

When a member is referred to herein as being "on " another member, it includes not only a member in contact with another member but also another member between the two members.

Whenever a component is referred to as "comprising ", it is to be understood that the component may include other components as well, without departing from the specification unless specifically stated otherwise.

According to an embodiment of the present invention, there is provided a method of manufacturing a water treatment separation membrane, comprising: preparing a porous support; Coating an aqueous solution comprising an amine compound and a water-soluble thickener on the porous support; And a step of interfacially polymerizing an aqueous solution containing the amine compound and an organic solution containing an acyl halide compound to form a polyamide active layer on the porous support.

In the case of using the high speed coating method such as the slot coating method instead of the dip coating method in forming the polyamide layer of the water treatment separation membrane, since the contact time between the porous support and the solution is very short, which is less than 1/100 in the dip coating method, Depending on the coating meniscus condition and rheological properties, the membrane performance may be different even in the same composition.

In particular, low-pressure high-flow products such as low-pressure high-flow products such as BW (brackish water) and TW (tap water) products require the use of aqueous solutions containing a low concentration of amine compounds. In this case, need.

Therefore, according to the state of implementation described in this specification, a high-speed coating method in which a solution contact time is limited by using a high-speed coating method, or even when the concentration of an amine compound in an aqueous solution containing an amine compound is low, It is characterized in that a water-soluble thickener is added to an aqueous solution containing an amine compound. By doing so, it is possible to increase the shear viscosity of the aqueous solution, thereby reducing the rate at which the amine compound diffuses into the pores of the porous support when the aqueous solution containing the amine compound is coated and allowing the amine compound to be positioned only on the porous support. Thus, the physical adhesion between the porous support and the polyamide layer can be adjusted to a low level.

According to another embodiment of the present invention, the step of coating the aqueous solution containing the amine compound and the water-soluble thickener may have a shear viscosity of 1-15 cps (shear viscosity) within a shear rate of 50 to 1500 / And may be performed to keep the range constant. For example, the shear viscosity may be kept constant within the shear rate range. Here, to be kept constant means that the deviation of the shear viscosity is 10% or less, preferably 5% or less. The control of the shear viscosity as described above can be performed by controlling the addition amount of the water-soluble thickener. In the present specification, the shear viscosity means the viscosity at the corresponding shear rate condition by calculating the coating shear rate according to the production rate.

 It is possible to prevent the amine compound from diffusing into the pores of the porous support in the aqueous solution coating at the shear rate and shear viscosity range described above and to lower the adhesion between the porous support and the polyamide layer to provide a high performance water treatment membrane suitable for high flow products .

According to another embodiment of the present invention, the step of coating an aqueous solution containing the amine compound and the water-soluble thickener is performed by a slot coating method. In the slot coating method, the contact time between the porous support and the aqueous solution is very short as compared with the dip coating method. For example, the contact time is as short as 1/100 or less as compared with dip coating. Nevertheless, by using the above-mentioned water-soluble thickener to increase the shear viscosity of the aqueous solution, it is possible to provide a high-performance water treatment separation membrane. For example, since the length of the contact area of the aqueous solution at a linear velocity of 5-40 m / min in the coating step is 250-500 μm, the contact time between the aqueous solution and the organic solution may be 0.03 to 0.06 seconds.

According to another embodiment of the present invention, the coating thickness of the aqueous solution may be determined as necessary, and may be determined depending on, for example, the conditions of the interfacial polymerization and the kind of the additive. According to one example, the coating thickness of the aqueous solution may be in the range of 10 to 1,000 mu m.

According to another embodiment of the present disclosure, the water-soluble thickener is a guar gum. J. of Col. And Interface Sci. v421, p33] describes the shear viscosity of guar gum by concentration. By using the shear viscosity of the guar gum according to the concentration, the concentration of guar gum can be determined to maintain a constant shear viscosity when the aqueous solution is coated.

According to another embodiment of the present invention, the content of the water-soluble thickener is 0.05 wt% to 0.5 wt%, specifically 0.1 wt% to 0.35 wt%, based on 100 wt% of the entire aqueous solution. Such a range of content is not only advantageous for achieving the above-mentioned shear viscosity but also does not prevent the inherent amount from passing through when the water treatment separator is used.

According to another embodiment of the present invention, the amine compound is not limited as long as it can be used in the polymerization of polyamide. Specific examples thereof include m-phenylenediamine (mPD), p-phenylenediamine (PPD) 1,3,6-benzenetriamine (TAB), 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3- Can be preferably used. The content of the amine compound may be 0.1 wt% or more and 20 wt% or less based on 100 wt% of the composition. However, even when a low concentration amine compound is contained in an amount of 3.5% by weight or less as described above, a high-performance water treatment separation membrane can be provided.

The step of bringing the aqueous solution containing the amine compound into contact with the organic solution containing the acyl halide compound may be carried out by any of those known in the art such as immersion, spraying, coating and the like, Similarly, a slot coating method can be used. When an amine compound and an acyl halide compound are brought into contact with each other, an amine compound and an acyl halide compound react with each other to form a polyamide by interfacial polymerization, and a thin film is formed on the porous support.

The acyl halide compound is not limited as long as it can be used in the polymerization of polyamides. Specific examples of the acyl halide compound include aromatic compounds having 2 to 3 carboxylic acid halides such as trimethoyl chloride, isophthaloyl chloride and terephthaloyl And a mixture of two or more selected from the group consisting of chlorides. The content of the acyl halide compound may be 0.05 wt% or more and 1 wt% or less based on 100 wt% of the composition.

The organic solvent includes an organic solvent. Examples of the organic solvent include aliphatic hydrocarbon solvents such as Freon and hydrophobic liquids such as hexane, cyclohexane, heptane, and alkane having 5 to 12 carbon atoms, For example, alkanes having 5 to 12 carbon atoms and mixtures thereof, such as IsoPar (Exxon), ISOL-C (SK Chem), and ISOL-G (Exxon), may be used.

The aqueous solution containing the amine compound or the organic solution containing the acyl halide compound may further include a permeation flux enhancer or a rejection enhancer as necessary. As a flux enhancing agent and a salt removal enhancer, those known in the art can be used. The content of the flux enhancing agent or the salt elimination enhancer may be determined depending on the kind and the necessity, for example, 0.01 wt% to 10 wt% based on 100 wt% of the composition.

According to one embodiment of the present invention, the porous support may be formed with a coating layer of a polymer material on a nonwoven fabric. Examples of the polymeric material include polymeric materials such as polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethyl chloride and polyvinylidene fluoride Rides, and the like may be used, but the present invention is not limited thereto. Specifically, polysulfone may be used as the polymer material.

According to one embodiment of the present disclosure, the thickness of the porous support may be 60 [mu] m to 100 [mu] m, but is not limited thereto and may be adjusted as necessary. The pore size of the porous support is preferably 1 nm to 500 nm, but is not limited thereto.

According to another embodiment of the present invention, the water treatment separation membrane manufactured by the manufacturing method according to the above-described embodiments includes a porous support and a polyamide layer provided on the porous support.

Fig. 1 illustrates the structure of the water treatment separation membrane. 1, the brine 400 is passed through the nonwoven fabric 100, the porous support 200 and the polyamide layer 300 of the water treatment separation membrane, the concentrated water 600 is removed, and the purified water 500 is separated from the water treatment separation membrane Lt; / RTI >

The water treatment separation membrane may further include an additional layer as required. For example, the reverse osmosis membrane may further include an anti-fouling layer provided on the polyamide active layer.

The water treatment separation membrane may be used as a microfiltration membrane, an ultrafiltration membrane, a nano filtration membrane or a reverse osmosis membrane, and may be specifically used as a reverse osmosis membrane.

One or more of the above-described water treatment membranes may be included in the water treatment module.

The specific type of the water treatment module is not particularly limited, and examples thereof include a plate & frame module, a tubular module, a hollow & fiber module, or a spiral wound module. In addition, as long as the water treatment module includes the water treatment separation membrane according to one embodiment of the present invention, other structures and manufacturing methods are not particularly limited and general means known in the art can be employed without limitation have.

On the other hand, the water treatment module including the water treatment separation membrane manufactured according to one embodiment of the present invention has excellent salt removal rate and permeation flow rate, and is excellent in chemical stability, and can be used for domestic / industrial water purification devices, sewage treatment devices, It can be usefully used in a water treatment apparatus.

Another embodiment of the present disclosure provides a composition for interfacial polymerization of a polyamide layer of a water treatment separation membrane that can be used in a manufacturing method according to the above-described embodiments. Specifically, the composition for interfacial polymerization of the polyamide layer of the water treatment separation membrane includes an amine compound, a water-soluble thickener, and water. Here, the description of the amine compound, the water-soluble thickener and the solvent other than water and their contents are as described above.

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.

Water treatment  Preparation of Membrane

Comparative Examples 1 to 3 and Examples 1 to 6

An aqueous solution containing mPD and guar gum (G.G) was coated on the polysulfone porous support by a slot coating method (coating speed 25 ft / min). The coating thickness (the thickness of the liquid coating prior to drying) at the time of coating, the shear rate, and the content of guar gum in 100 wt.% Aqueous solution and the shear viscosity of the aqueous solution were as shown in Table 1 below. Since 90% or more of the aqueous solution was water and mPD had no influence on the shear viscosity, shear viscosity was measured after adding a thickener in an amount corresponding to Table 1 below. The shear rate in Table 1 is calculated by calculating the shear rate in the actual slot coating process. After coating as described above, the surface residual mPD content per unit area was measured. The coating thickness was the distance between the coating nozzle and the surface of the fabric, measured by gap gauge. Shear rate is line speed (line speed) / coating thickness. Shear viscosity was measured by shear rate using a cup and spindle fixture at Rheomety.

Then, an organic solution containing TMC was coated and subjected to interfacial polymerization to obtain a polyamide layer. The salt rejection and permeation flux of the water treatment separator containing the polyamide layer thus obtained were measured and are shown in Table 1 below. Salt retentivity and permeate flow rate were evaluated at 80 psi pressure in an aqueous solution containing 500 ppm NaCl.

Coating speed (25 ft / min) Flat sheet
Test results Residual mPD content (g / m ² )
Coating thickness
(μm) Shear rate
(s-1) GG
(weight%) Shear viscosity
(cps s) Rejection
(%) Flux
(GFD) Comparative Example 1
100

1270
N / A One 99.66 30.1 - Example 1 0.15 5 99.67 33.4 840.2 Example 2 0.30 10.5 99.64 38.7 1749.0 Comparative Example 2
300

423
N / A One 99.63 33.0 - Example 3 0.15 6.5 99.62 35.9 1199.9 Example 4 0.30 12 99.63 39.3 1853.3 Comparative Example 3
650

195
N / A One No coating - Example 5 0.15 7.5 99.60 38.6 1344.7 Example 6 0.30 14 99.59 40.5 1978.9

As shown in Table 1 above, when guar gum was added as an aqueous thickener to an aqueous solution containing mPD, viscosity increased. In this case, the mPD diffusion rate into the porous support is lowered, so that the mPD is present on the porous support and the adhesion between the porous support and the polyamide layer is lowered. As a result, it was possible to fabricate a water treatment membrane having a high permeate flow rate with little loss of salt removal rate.

Further, since a film having a high permeation flow rate can be formed under a low shear rate, it can be seen that a thicker coating thickness can be formed by increasing the viscosity of an aqueous solution, and it is advantageous in securing a wider process condition in a high-speed slot coating.

100: Nonwoven fabric
200: Porous support
300: polyamide layer
400: brine
500: Purified water
600: concentrated water

Claims (12)

Preparing a porous support;
Coating an aqueous solution comprising an amine compound and a water-soluble thickener on the porous support; And
A step of interfacially polymerizing an aqueous solution containing the amine compound and an organic solution containing an acyl halide compound to form a polyamide active layer on the porous support. The method for producing a water treatment separation membrane according to claim 1, wherein the content of the amine compound is 3.5 parts by weight or less based on 100 parts by weight of the aqueous solution containing the amine compound and the water-soluble thickener. The method of claim 1, wherein the step of coating the aqueous solution comprising the amine compound and the water-soluble thickening agent maintains a shear viscosity of 1 cps to 15 cps within a shear rate of 50 / s to 1500 / Lt; RTI ID = 0.0 > 1, < / RTI > The method according to claim 1, wherein the step of coating the aqueous solution containing the amine compound and the water-soluble thickener is performed by a slot coating method. The method for producing a water treatment separation membrane according to claim 1, wherein the contact time of the aqueous solution and the organic solution is 0.03 seconds to 0.06 seconds. The method according to claim 1, wherein the water-soluble thickener is guar gum. The method for producing a water treatment separation membrane according to claim 1, wherein the content of the water-soluble thickener is 0.05 to 0.5 parts by weight based on 100 parts by weight of the aqueous solution. A composition for interfacial polymerization of a polyamide layer in a water treatment separator comprising an amine compound, a water-soluble thickener and water. The composition according to claim 8, wherein the content of the amine compound is 3.5 parts by weight or less based on 100 parts by weight of the composition. The composition according to claim 8, wherein the composition has a shear viscosity of 1 cps to 15 cps. The composition according to claim 8, wherein the water-soluble thickener is guar gum. The composition according to claim 8, wherein the content of the water-soluble thickener is 0.05% by weight to 0.5% by weight based on 100% by weight of the total composition.

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