KR20200044501A - Separation membrane, composition for active layer of separation membrane, and method for separation membrane - Google Patents

Abstract

The present invention relates to a separation membrane including a porous layer and an active layer containing a compound having a phosphoryl group and a trifluoromethyl group. The present invention also relates to a composition for forming the active layer of the separation membrane and a manufacturing method of the separation membrane. A salt removal rate and flow rate can be improved at the same time.

Description

Separation membrane, composition for forming active layer of separation membrane and manufacturing method of separation membrane {SEPARATION MEMBRANE, COMPOSITION FOR ACTIVE LAYER OF SEPARATION MEMBRANE, AND METHOD FOR SEPARATION MEMBRANE}

The present specification relates to a separation membrane, a composition for forming an active layer of the separation membrane, and a method of manufacturing the separation membrane.

The phenomenon in which the solvent moves between the two solutions separated by the permeable membrane through the separation membrane from the solution having a low solute concentration to the high solution is called an osmotic phenomenon, and at this time, the pressure acting on the side of the solution having a high solute concentration by the movement of the solvent. Is called osmotic pressure. However, when an external pressure higher than the osmotic pressure is applied, the solvent moves toward a solution having a low solute concentration, which is called reverse osmosis. By using the reverse osmosis principle, various salts or organic substances can be separated through a semi-permeable membrane using a pressure gradient as a driving force. Reverse osmosis membranes using this reverse osmosis phenomenon are used to separate molecular-level materials and remove salts from salt water or sea water to supply water for household, construction, and industrial use.

A typical example of such a reverse osmosis membrane is a polyamide-based reverse osmosis membrane, and the polyamide-based reverse osmosis membrane is produced by a method of forming a polyamide active layer on a microporous layer support, and more specifically, a polysulfone layer on a nonwoven fabric. Forming to form a microporous support, and immersing the microporous support in an aqueous solution of m-Phenylene Diamine (mPD) to form an mPD layer, which is again trimesoyl chloride (TMC) organic It is produced by a method of forming a polyamide layer by interfacial polymerization by immersing in a solvent to contact the mPD layer with TMC.

Korean Patent Publication 10-2015-0016475

The present specification provides a separation membrane, a composition for forming an active layer of the separation membrane, and a method of manufacturing the separation membrane.

An exemplary embodiment of the present specification is a porous layer; And an active layer comprising a compound containing a phosphoryl group and a trifluoromethyl group.

One embodiment of the present specification provides a water treatment module including the separator.

An exemplary embodiment of the present specification provides a composition for forming an active layer of a separator comprising a compound containing a phosphoryl group and a trifluoromethyl group and an acyl halide compound.

An exemplary embodiment of the present specification is forming a porous layer; And forming an active layer comprising a compound comprising a phosphoryl group and a trifluoromethyl group on the porous layer.

The separation membrane according to the exemplary embodiment of the present specification may simultaneously improve the salt removal rate and the flow rate by using an additive having a phosphoryl group and a trifluoromethyl group at the same time when forming the active layer.

1 shows a separator according to an exemplary embodiment of the present specification.
2 illustrates a water treatment module according to an exemplary embodiment of the present specification.

When a member is referred to as being “on” another member in the present specification, this includes not only the case where one member abuts another member, but also another member between the two members.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless specifically stated otherwise.

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

An exemplary embodiment of the present specification is a porous layer; And an active layer comprising a compound containing a phosphoryl group and a trifluoromethyl group.

In the reverse osmosis membrane, improving the salt removal rate and flow rate is the most important issue, and in the past, a method of increasing physical properties by using chemical methods such as fluorine-based additives has been used when forming the active layer of the reverse osmosis membrane.

However, the fluorine-based additives previously used have improved salt removal rates, but have a side effect of reducing the flow rate.

The separator according to the exemplary embodiment of the present specification may simultaneously improve the salt removal rate and flow rate of the separator including the active layer by including a compound containing phosphoryl and trifluoromethyl groups simultaneously in the active layer.

The fluorine functional group of the trifluoromethyl group improves the salt removal rate, and the phosphoryl group increases the diffusion rate in the process where the m-phenylenediamine (mPD) in the aqueous solution becomes an organic phase, m-phenylenediamine (mPD) And trimethoyl chloride (TMC) to increase the reaction, thereby improving the flow rate of the membrane.

In one embodiment of the present specification, the compound containing the phosphoryl group and the trifluoromethyl group may be n-triflylphosphoramide.

In an exemplary embodiment of the present specification, the active layer including the compound containing the phosphoryl group and the trifluoromethyl group may further include -SH-, -OH and -NH- as functional groups that react with acyl chloride.

In one embodiment of the present specification, the thickness of the active layer may be 150 nm to 250 nm, and preferably 180 nm to 220 nm.

In the present specification, the porous layer includes a first porous support and a second porous support.

A nonwoven fabric may be used as the first porous support. Polyethylene terephthalate may be used as the material of the nonwoven fabric, but is not limited thereto.

The thickness of the nonwoven fabric may be 50 μm to 150 μm, but is not limited thereto. Preferably, the thickness may be 80 μm to 120 μm. When the thickness of the nonwoven fabric satisfies the above range, durability of the separation membrane including the porous layer may be maintained.

The second porous support may mean that a coating layer of a polymer material is formed on the first porous support. As the polymer material, for example, polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethylchloride, and polyvinylidene fluoride Ride and the like may be used, but is not necessarily limited to these. Specifically, polysulfone can be used as the polymer material.

The thickness of the second porous support may be 20 μm to 100 μm, but is not limited thereto. Preferably, the thickness may be 40 μm to 80 μm. When the thickness of the coating layer satisfies the above range, durability of the separator including the porous layer including the second porous tooth body may be properly maintained.

In one embodiment of the present specification, the thickness of the first porous support and the thickness of the second porous support can be measured by cutting the separator to 10 cm x 10 cm and preparing a sample, using a digimatic thickness gauge. . The thickness can be determined by measuring the thickness 5 times using the digimatic thickness gauge, and then obtaining the average value.

The digimatic thickness gauge may be from Mitutoyo, but is not limited thereto, and one known in the art may be used.

According to an example, the second porous support may be made of a polymer solution containing the polysulfone. The polymer solution containing the polysulfone, based on the total weight of the polymer solution containing the polysulfone, put polysulfone solids of 10% to 20% by weight in 80% to 90% by weight of solvent dimethylformamide It may be a homogeneous liquid obtained after melting at 80 ° C to 85 ° C for 12 hours, but the weight range is not limited to the above range.

When the polysulfone solid in the above range is included based on the total weight of the polymer solution containing the polysulfone, the durability of the separator including the second porous support may be appropriately maintained.

The second porous support may be formed by a method of casting. The casting means a solution casting method. Specifically, after dissolving the polymer material in a solvent, it may mean a method of displacing the solvent after being developed on a smooth, non-adhesive surface. Specifically, the method of substituting with the solvent may use a nonsolvent induced phase separation method. With the non-solvent-induced phase separation method, a polymer is dissolved in a solvent to form a uniform solution, molded into a certain shape, and then immersed in a non-solvent. After that, the interaction between diffusion of the non-solvent and the solvent is carried out, the composition of the polymer solution changes, and precipitation of the polymer occurs, thereby forming a portion of the solvent and the non-solvent into pores.

In one embodiment of the present specification, the active layer may be a polyamide active layer. The active layer may be formed through interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound.

Specifically, upon contact between the aqueous solution layer containing the amine compound and the organic solution, an amine compound coated on the surface of the porous layer and an acyl halide compound react to generate polyamide by interfacial polymerization, and the porous layer It is adsorbed to form a thin film. In the above contact method, the polyamide active layer may be formed through a method such as dipping, spraying or coating.

According to an exemplary embodiment of the present specification, the amine compound included in the aqueous solution layer containing the amine compound may be an aromatic amine compound.

According to an exemplary embodiment of the present specification, the aromatic amine compound is not limited if it is an aromatic amine compound used in the production of a separator, for example, m-phenylenediamine (mPD), p-phenylenediamine, It may be one or more selected from the group consisting of 1,2,4-benzenetriamine, 4-chloro-1,3-phenylenediamine, 2-chloro-1,4-phenylenediamine, and mixtures thereof. Specifically, m-phenylenediamine (mPD) is preferable.

According to an exemplary embodiment of the present specification, the solvent of the aqueous solution containing the amine compound may be water, and the remainder excluding the amine compound in the aqueous solution containing the amine compound may be water. When the aqueous solution containing the amine compound further includes a basic acid acceptor, which will be described later, if necessary, the balance excluding the amine compound and the basic acid acceptor may be water.

The aqueous solution containing the amine compound may further include a basic acid acceptor, if necessary. The basic acid acceptor may be, for example, a trialkylamine compound, specifically, triethyleneamine camposulfonic acid, but is not limited thereto. The basic acid acceptor may be included from 1% to 10% by weight based on the total weight of the aqueous solution containing the amine compound.

According to an exemplary embodiment of the present specification, based on the total weight of the aqueous solution containing the amine compound, the content of the amine compound may be 2% to 6% by weight. When the above content is satisfied, the salt removal rate and flow rate required in industrial operating conditions can be secured.

According to an exemplary embodiment of the present specification, the acyl halide compound is not particularly limited, but, for example, as an aromatic compound having 2 to 3 carboxylic acid halides, trimesoyl chloride (TMC), isophthaloyl It may be a mixture of one or more selected from the group consisting of chloride, terephthaloyl chloride, and mixtures thereof.

According to an exemplary embodiment of the present specification, the content of the acyl halide compound may be included 0.1% to 0.3% by weight based on the total weight of the organic solution containing the acyl halide compound. When the content of the acyl halide compound satisfies the above range, it is possible to secure a salt removal rate and a flow rate required in industrial operating conditions.

Further, according to an exemplary embodiment of the present specification, the organic solution containing the acyl halide compound may further include an organic solvent, and the organic solvent may include an aliphatic hydrocarbon solvent, for example, freons and 5 to 5 carbon atoms. Hydrophobic liquids that are immiscible with water such as hexane, cyclohexane, heptane, alkanes of 12, for example, alkanes having 5 to 12 carbon atoms and mixtures thereof, IsoPar (Exxon), ISOL-C (SK Chem), ISOL-G (Exxon), IsoPar G, etc. may be used, but is not limited thereto. Preferably, the organic solvent may be IsoPar G.

According to an exemplary embodiment of the present specification, the organic solvent is the organic solvent containing the acyl halide compound, the remainder excluding the acyl halide compound may be the organic solvent. When the organic solution containing the acyl halide compound further includes the silicone additive, the remainder excluding the acyl halide compound and the silicone additive may be the organic solvent.

An exemplary embodiment of the present specification provides a separation membrane having a salt removal rate of 99.3% to 99.7% and a flow rate of 21 GFD to 27 GFD at 2,000 ppm NaCl aqueous solution, pressure 150 psi, temperature 25 ° C., and 4 L / min.

An exemplary embodiment of the present specification provides a separation membrane having a salt removal rate of 99.35% to 99.5% and a flow rate of 21 GFD to 25 GFD at 2,000 ppm NaCl aqueous solution, pressure 150 psi, temperature 25 ° C., and 4 L / min.

The salt removal rate is 2,000 ppm NaCl aqueous solution, pressure 150 psi, temperature 25 ℃, after operating the water treatment module containing the separation membrane for 1 hour under conditions of 4, after measuring the conductivity of raw water and production water to measure the salt removal rate You can.

The flow rate is calculated by calculating the amount of water produced within a certain time after operating the water treatment module including the separation membrane for 1 hour under a condition of 4 L / min under a condition of 2,000 ppm NaCl aqueous solution, pressure of 150 psi, and temperature of 25 ° C. The predetermined time may be 1 hour to 2 hours. Preferably it may be 1 hour.

An exemplary embodiment of the present specification is forming a porous layer; And forming an active layer comprising a compound containing a phosphoryl group and a trifluoromethyl group on the porous layer.

In the step of forming the porous layer, the porous layer is according to the above description.

The forming of the porous layer may include forming a second porous support on the first porous support. The method of forming the second porous support is based on the above description.

In an exemplary embodiment of the present specification, the active layer may mean a polyamide active layer, and the polyamide active layer includes forming an aqueous layer containing an amine compound on the porous layer; It may be formed through the step of forming an polyamide active layer by contacting an organic solution containing an acyl halide compound on the aqueous solution layer containing the amine compound.

The polyamide active layer may be formed by generating polyamide by interfacial polymerization and adsorbing on the porous layer while the amine compound and the acyl halide compound react upon contact of the amine compound and the acyl halide compound.

The contact may be a method such as dipping, spraying or coating. As the conditions for the interfacial polymerization, those known in the art may be used.

The method of forming an aqueous solution layer containing an aromatic amine compound on the porous layer is not particularly limited, and any method capable of forming an aqueous solution layer containing an amine compound on the porous layer can be used without limitation. Specifically, a method of forming an aqueous layer containing the amine compound on the porous layer may include spraying, coating, dipping, dropping, and the like, and those known in the art may be used.

At this time, the aqueous layer containing the amine compound may be further subjected to a step of removing the aqueous solution containing the excess amine compound, if necessary. The aqueous solution layer containing the amine compound formed on the porous layer may be non-uniformly distributed when the aqueous solution containing the amine compound present on the porous layer is too large, and the aqueous solution containing the amine compound is non-uniformly distributed. If it does, a heterogeneous polyamide active layer may be formed by subsequent interfacial polymerization. Therefore, it is preferable to remove the aqueous solution containing excess amine compound after forming an aqueous solution layer containing the amine compound on the porous layer. The removal of the aqueous solution containing the amine compound is not particularly limited, but may be performed using, for example, a sponge, an air knife, nitrogen gas blowing, natural drying, or a compression roll.

In one embodiment of the present specification, the forming of the active layer is performed by interfacial polymerization of an aqueous solution containing the amine compound and an organic solution containing an acyl halide compound, and includes the phosphoryl group and trifluoromethyl group The compound may be 0.001% to 0.05% by weight based on the total weight of the organic solution containing the acyl halide compound, and preferably 0.001% to 0.01% by weight.

When the compound containing the phosphoryl group and the trifluoromethyl group is added to the organic solution containing the acyl halide compound in the weight% range, both the flow rate of the separator and the salt removal rate can be improved, and it exceeds 0.01% by weight. When included as, the flow rate of the membrane increases, but the salt removal rate may decrease.

According to an exemplary embodiment of the present specification, the separation membrane may be used as a micro filtration membrane (Micro Filtration), ultra filtration membrane (Ultra Filtration), nano filtration membrane (Nano Filtration) or reverse osmosis membrane (Reverse Osmosis), specifically, used as a reverse osmosis membrane Can be.

One embodiment of the present specification provides a water treatment module including the separator. The separation membrane included in the water treatment module may be 1 to 50, may be 1 to 30, preferably 24 to 28, but is not limited thereto.

The specific type of the water treatment module is not particularly limited, and examples thereof may 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 above-described separator, other configurations and manufacturing methods are not particularly limited, and general means known in the field can be employed without limitation.

1 shows a separator according to an exemplary embodiment of the present specification. Specifically, FIG. 1 shows a separator in which the first porous support 100, the second porous support 200, and the active layer 300 are sequentially provided, and brine 400 is introduced into the active layer 300, The purified water 500 is discharged through the support 100, and the concentrated water 600 is discharged to the outside without passing through the active layer 300.

2 illustrates a water treatment module according to an exemplary embodiment of the present specification. Specifically, the water treatment module includes a central tube 40, a feed spacer 20, a separation membrane 10, a tricoat filtered waterway 30, and the like. When the raw water flows through the water treatment module, the raw water flows through the supply spacer 20 in the water treatment module. The one or more separators 10 extend outwardly from the tube 40 and are wound around the tube 40. The supply spacer 20 forms a passage through which raw water flows from the outside, and serves to maintain a gap between one separation membrane 10 and the other separation membrane 10. To this end, the supply spacer 20 is in contact with one or more separators 10 on the upper side and the lower side, and is wound around the tube 40. The tricoat filtered water channel 30 generally has a structure in the form of a fabric, and serves as a flow path that creates a space through which purified water can flow through the separation membrane 10. The tube 4 is located at the center of the water treatment module, and serves as a passage through which filtered water is introduced and discharged. At this time, the outside of the tube 40, it is preferable that the pores of a predetermined size is formed so that the filtered water is introduced, it is preferable that one or more are formed.

Hereinafter, examples will be described in detail to specifically describe the present specification. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present specification is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

Example 1.

(Production of porous layer)

A non-woven fabric was used as the first porous support, the non-woven fabric was polyethylene terephthalate, and polyethylene terephthalate having a thickness of 100 μm was used.

To prepare a second porous support (polysulfone layer) on the first porous support, a polymer solution containing polysulfone was prepared. The polymer solution containing the polysulfone, based on the total weight of the polymer solution containing the polysulfone, put 16% by weight of polysulfone solid in 84% by weight of solvent dimethylformamide (80 to 85 ° C) It was a homogeneous liquid obtained after dissolving in for 12 hours.

Thereafter, a polymer solution containing the polysulfone was cast on the first porous support (polyethylene terephthalate) at 40 μm by a slot die coating method to prepare a second porous support (polysulfone layer). Through this, a porous layer including a first porous support and a second porous support (polysulfone layer) was prepared.

(Preparation of active layer)

In order to prepare an active layer on the porous layer, an aqueous solution containing an amine compound was prepared. The aqueous solution containing the amine compound included 4% by weight of metaphenylenediamine (mPD) and 5% by weight of triethyleneamine camposulfonic acid (TEACSA) based on the total weight of the aqueous solution containing the amine compound.

Thereafter, an aqueous solution containing the prepared amine compound was applied on the support to form an aqueous solution layer. Furthermore, the excess aqueous solution generated during application was removed using an air knife.

On the aqueous layer containing 0.2% by weight of trimethoyl chloride (TMC), 0,001% by weight of n-triflylphosphoramide (n-triflylphosphoramide) and the balance of organic solvent (IsoPar G) relative to the total organic solution The organic solution was applied.

Then, after drying until all the liquid components evaporated at 95 ℃, and washed with ultrapure distilled water (DIW) to prepare a separator.

Example  2.

A separator was prepared in the same manner as in Example 1, except that in Example 1, 0.01% by weight of n-triflylphosphoramide was used.

Comparative example  One.

A separator was prepared in the same manner as in Example 1 described above, except that n-triflylphosphoramide was not used.

Comparative example  2.

A separator was prepared in the same manner as in Example 1, except that 0.01% by weight Hexamethyl phosphoamide (manufactured by Sigma-Aldrich, Hexamethylphosphoramide) was used instead of n-triflylphosphoramide.

Comparative example  3.

A separation membrane was prepared in the same manner as in Example 1, except that 0.01% by weight of Trifluoromethyl aniline Sigma-Aldrich (4- (Trifluoromethyl) aniline) was used instead of n-triflylphosphoramide. .

Comparative example  4.

A separator was prepared in the same manner as in Example 1, except that 0.1% by weight of n-triflylphosphoramide was used as an additive.

Experimental example .

(Measurement of separator performance)

Salt removal rate and flow measurement

After confirming that the separation membranes prepared according to Examples 1, 2 and Comparative Examples 1 to 4 were stabilized by performing 2,000 ppm of NaCl aqueous solution at a flow rate of 150 psi, 4 L / min for 1 hour, operating the equipment for about 1 hour. The amount of water permeated at 10 ° C is measured to calculate the permeate flow rate (flux: GFD (gallon / ft ² · day)), and the salt removal rate is analyzed by analyzing the salt concentration before and after permeation using a conductivity meter. Rejection) is calculated in Table 1 below.

[Table 1]

The performance change of Table 1 is a change value of salt removal rate and flow rate for Examples 1 and 2 and Comparative Examples 2 to 4 based on Comparative Example 1 without additives.

As shown in Table 1, the separation membrane (Examples 1 and 2) containing an additive containing a phosphoryl group and a trifluoromethyl group according to an exemplary embodiment of the present specification, Comparative Example 1, POS without additives Comparative Example 2 containing only the additive containing only the poryl group, Comparative Example 3 containing only the additive containing only the trifluoromethyl group, and the separation membrane of Comparative Example 4 using 0.1% by weight of n-triflylphosphoramide (n-triflylphosphoramide) It was confirmed that the salt removal rate and the flow rate were improved simultaneously.

10: separator
20: Supply spacer
30: Tricot filtered water
40: tube
100: first porous support
200: second porous support
300: active layer
400: brine
500: purified water
600: concentrated water

Claims (11)

Porous layer; And
Separator comprising an active layer comprising a compound containing a phosphoryl group and a trifluoromethyl group. The method according to claim 1, wherein the compound containing a phosphoryl group and a trifluoromethyl group is a separation membrane that is n-triflylphosphoramide (n-triflylphosphoramide). The separator according to claim 1, wherein the active layer is a polyamide active layer. The method according to claim 1, The thickness of the active layer is 150 nm to 250 nm separation membrane. The method according to claim 1, 2,000ppm NaCl aqueous solution, pressure 150 psi, temperature 25 ℃, salt removal rate is 99.3% to 99.7% at 4L / min conditions, the flow rate is 21 GFD to 27 GFD separation membrane. A water treatment module comprising one or more of the separators according to claim 1. A composition for forming an active layer of a separation membrane comprising a compound containing a phosphoryl group and a trifluoromethyl group and an acyl halide compound. The composition for forming an active layer of a separation membrane according to claim 7, wherein the composition further comprises an organic solvent. Forming a porous layer; And
Method for producing a separation membrane comprising the step of forming an active layer comprising a compound containing a phosphoryl group and a phosphoryl group and a trifluoromethyl group on the porous layer. The method according to claim 9, The active layer is formed by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound,
The organic solution containing the acyl halide compound further comprises a compound containing the phosphoryl group and trifluoromethyl group. The method of claim 10, wherein the compound containing the phosphoryl group and trifluoromethyl group comprises 0.001% to 0.01% by weight based on the total weight of the organic solution containing the acyl halide compound.

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