KR20220071138A - Hydrophilized porous polymer filter, preparation method thereof, and useing the same for dehumidification - Google Patents

Abstract

The present invention relates to a polymer filter which has pores having an average size of 0.05 to 10 μm on one surface and pores coated with a hydrophilic polymer and having an average size of 1 to 10 nm on the other surface, and is hydrophilized on one side, a manufacturing method thereof including a step of immersing one surface of a porous polymer filter in a vinyl-based monomer solution of a polymer containing a hydrophilic functional group to polymerize the same, and a use thereof for dehumidification.

Description

Hydrophilized porous polymer filter, manufacturing method thereof, and dehumidification use thereof

The present invention is a polymer filter having an average size of 0.05 to 10 μm on one surface, and a hydrophilic polymer coated with a hydrophilic polymer on the other surface to have pores of an average size of 1 to 10 nm, hydrophilic on one side, including a hydrophilic functional group It relates to a method for preparing the same, including the step of immersing one surface of a porous polymer filter in a solution of a vinyl-based monomer of a polymer to polymerize it, and to a use for dehumidifying the same.

In general, the dehumidification process uses the principle of cooling and condensing humid air. This dehumidification process uses a refrigerant to cool the air, so a process that consumes a lot of energy is required and requires less energy. Another dehumidification method may use a porous material to absorb moisture. However, dehumidification takes a long time and is not efficient. Recently, attempts have been made to dehumidify using a separator, but there is a problem in that the efficiency is greatly reduced. That is, the surface pores are too small and the moisture permeability is too low.

As a result of intensive research efforts to discover a method for treating the surface of a porous polymer filter to provide a filter with improved water permeation capacity usable in the dehumidification process, the present inventors have made one surface of the porous polymer filter a polymer vinyl containing a hydrophilic functional group. By coating the pore surface of the porous polymer by immersion in a solution containing a system monomer and polymerization, it selectively imparts hydrophilicity and at the same time controls the pore size to increase compared to a filter coated with an untreated or polymer solution containing the same hydrophilic functional group It was confirmed that the water permeation capacity can be achieved, and the present invention was completed.

Each description and embodiment disclosed in the present invention is also applicable to each other description and embodiment. That is, all combinations of the various elements disclosed herein fall within the scope of the present invention. In addition, it cannot be said that the scope of the present invention is limited by the specific descriptions described below.

In addition, those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Also, such equivalents are intended to be encompassed by the present invention.

In addition, throughout the specification of the present invention, when a part "includes" a certain component, it does not exclude other components unless otherwise stated, but may further include other components. it means.

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

The present invention is designed to improve the efficiency of the conventional separator-based dehumidifying filter because it exhibits a low water permeation flow rate due to a small pore size on the surface. Specifically, the present invention uses a nonsolvent-induced phase separation (NIPS) method, but is exposed to a high humidity environment before immersion in a nonsolvent to prepare a polymer filter having pores of several microns in size, Optionally, when introducing a hydrophilic polymer coating layer through polymerization on the pore surface from a monomer solution of a polymer having a hydrophilic functional group on one side thereof, the surface of the membrane can be hydrophilized and the pore size can be adjusted at the same time, so that the water permeation flow rate is increased It is a feature of the present invention that it has been found that it is possible to provide a dehumidifying filter with improved dehumidification efficiency.

In a first aspect of the present invention, one surface of a porous polymer filter is formed of a polymer containing at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amine group, a sulfuric acid group, a nitro group, a phosphoric acid group, and a carbonic acid group. A vinyl monomer and an initiator. It provides a method for producing a porous polymer filter having a controlled pore size by selectively introducing a polymer coating layer having a hydrophilic functional group on one surface, comprising the step of coating the pore surface of the porous polymer by immersing it in a solution containing .

For example, the porous polymer filter is formed by casting a polymer solution containing 8 to 30% by weight of a polymer, 10 to 50% by weight of an additive and an extra solvent based on the total solution weight to a predetermined thickness, and a relative humidity of 60% or more. After standing for 0.5 to 10 minutes in a, it can be prepared by immersion in a non-solvent of 50 to 80 ℃, but is not limited thereto.

Specifically, the polymer is polyethersulfone (PES), polysulfone (PSU), cellulose acetate (cellulose acetate), polyarylene ether sulfone (poly(arylene ether sulfone); PAES), polyarylene sulfone (poly(arylene sulfone)), polyvinyledene fluoride (PVDF), polytetrafluoroethylene, polyethylene, polyimide, polyetherimide, polyamideimide, polyethylene vinyl alcohol, polyacrylonitrile, nylon, It may be any one selected from the group consisting of polyester, and polyketone, or a copolymer of two or more, or a mixture thereof, but is not limited thereto.

As described above, the polymer solution may contain 8 to 30% by weight of the polymer. For example, if the polymer content in the solution is less than 8% by weight, it may be difficult to form a filter due to low viscosity, and if it is more than 30% by weight, it may be difficult to form pores.

For example, the additive contained in the polymer solution may improve the porosity and porosity of the separator, and specifically, ethylene glycol (EG) or a polymer thereof may be used. More specifically, the additive has a molecular weight of 60 to 200,000, and ethylene glycol, diethylene glycol (DEG), triethylene glycol, polyethylene glycol, etc. may be used alone or in mixture of two or more, but is not limited thereto.

As described above, the polymer solution may contain 10 to 50% by weight of the additive. For example, if the content of the additive in the solution is less than 10% by weight, it may be difficult to form pores, and if it is more than 50% by weight, it may be difficult to form the polymer solution itself.

As used herein, the term "nonsolvent" is a solvent that is not compatible with the polymer. Specifically, in the interaction between a liquid and a polymer organized by Flory, it means a solvent that does not dissolve the polymer because the interaction is the weakest in terms of the attractiveness of the interaction and the degree and strength of dissolving the polymer. Accordingly, the type of non-solvent may be different depending on the type of polymer and/or physical and chemical properties.

As described above, the polymer filter of the present invention can be prepared by a non-solvent induced phase separation method, which is a method of forming pores by immersing a polymer solution in a non-solvent. can be freely adjusted in size.

At this time, there are several factors that control the structure of the separator, one example is the concentration of the polymer in the polymer solution and the relative velocity of the solvent removed from the polymer solution and the nonsolvent entering the polymer solution. In general, if the rate at which the nonsolvent enters is faster than the rate at which the solvent is removed from the polymer solution, a separation membrane having a porous structure is formed. Other factors that determine the structure of the separation membrane include the solvent or solvent system, the type of coagulation, and the temperature of the non-solvent. If the coagulation rate is slow, a separator having a sponge-shaped microporous structure may be produced, and if the coagulation rate is high, a separator having a finger-shaped structure may be produced.

On the other hand, when the polymer material to be used is determined, a solvent and a non-solvent can be selected accordingly. Water is generally used as the non-solvent, and the choice of solvent is limited because the non-solvent and the solvent must be mixed with each other. Examples of solvents that are miscible with water and have excellent polymer solubility include dimethyl formamide (DMF), dimethyl acetamide (DMAc), N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone; NMP), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), γ-butyrolactone (GBL), 1,4-dioxane (1,4-dioxane), acetone (acetone), etc. Although the above solvents are miscible with water, their compatibility is different. The degree of affinity between the nonsolvent and the solvent affects the rate of phase separation. In general, when the affinity is large, the phase separation rate increases, and when the affinity is small, it decreases. For example, DMF, DMAc, NMP, DMSO, etc. have a high affinity for water, and THF, GBL, 1,4-dioxane, etc. have relatively low affinity. When the affinity between the nonsolvent and the solvent is high, that is, when the phase separation rate is high, the resulting polymer membrane has large pores, so it is mostly applied to ultrafiltration membranes rather than gas separation membranes.

For example, the solvent may be used without limitation as long as it is a material capable of dissolving 15% or more of the selected polymer at room temperature. For example, the solvent may be a single solvent or a mixed solvent of two or more selected from the group consisting of dimethylformamide (DMF), dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. can, but is not limited thereto. More specifically, dimethylformamide may be used, but is not limited thereto.

The non-solvent may be a solvent selected from the group consisting of water, glycerol, ethanols, ketones and ethers, or a mixture thereof, but is not limited thereto. The non-solvent may also include a mixture of a solvent and a non-solvent for mixing with the solvent in a subsequent process.

For example, it can be prepared by casting the polymer solution to a constant thickness while maintaining constant humidity and temperature on a solid film such as polyester to form a filter, and then immersing it in a nonsolvent to solidify. At this time, the relative humidity is preferably maintained at 60% or more. When the relative humidity falls below 60%, it is difficult to form pores on the surface, so that the water vapor permeability of the finally formed filter may be lowered. On the other hand, the temperature of the non-solvent is preferably maintained at 50 to 80 ℃. For example, when the temperature of the non-solvent is lowered to less than 50 ° C., it is difficult to form pores on the surface, so the water vapor permeability of the finally formed filter may be lowered. .

The vinyl-based monomer of the polymer including the functional group may be a compound including an unsaturated carbon bond capable of forming a polymer skeleton by polymerization and at least one of the above-mentioned hydrophilic functional groups in the molecule. For example, the vinyl-based monomer of the polymer including the functional group may be acrylic acid, vinylsulfonic acid, vinylamine, methacrylic acid, vinyl alcohol, or a mixture thereof, but is not limited thereto, and carboxylic acid, amine, sulfonic acid , nitro, or may include an alcohol group, but is not limited thereto. For example, the monomer may be a substance soluble in water or lower alcohol. Furthermore, the monomer may be used in a concentration of 0.1 to 1 wt%. If the concentration of the monomer is less than 0.1% by weight, it is difficult to achieve the expected level of improvement in hydrophilicity, and if it exceeds 1% by weight, the size of the finally formed pores becomes too small, so that the water permeation amount may be significantly reduced.

For example, the initiator may be azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO) or di-tert-butyl peroxide (DEBP). However, it is not limited thereto. In this case, the initiator may be used at a concentration of 0.001 to 0.01 wt%. If the initiator concentration is less than 0.001% by weight, polymer polymerization is significantly delayed and the process takes a lot of time, and if it exceeds 0.01% by weight, it no longer affects the polymerization and the reagent is wasted.

For example, the polymerization may be performed by heating to 70 to 100° C. and leaving it to stand for 5 to 60 minutes, but is not limited thereto. For example, a polymerization method of a polymer of vinyl type known in the art may be used without limitation.

A second aspect of the present invention is a polymer filter having an average size of 0.05 to 20 µm on one surface, and a hydrophilic polymer coated on the other surface, having pores of an average size of 1 to 10 nm, a hydrophilic polymer filter. to provide.

For example, the polymer filter may be manufactured by the manufacturing method of the first aspect described above, but is not limited thereto.

For example, it is characterized in that the dehumidification efficiency is improved due to the hydrophilic polymer coating and pores having a controlled size.

Specifically, the polymer filter of the present invention may exhibit an increased water permeation flow rate of 0.2 kg/m ² ·hr or more, but is not limited thereto. This suggests that since the polymer filter of the present invention can achieve the moisture permeation capacity required for the dehumidifying membrane used in the electrodeposition coating process, it can be utilized.

For example, the polymer is polyethersulfone, polysulfone, cellulose acetate, polyaryleneethersulfone, polyarylenesulfone, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polyimide, polyetherimide, polyamideimide , polyvinyl alcohol, polyacrylonitrile, nylon, polyester, and any one selected from the group consisting of polyketone, may be a copolymer of two or more or a mixture thereof, but is not limited thereto.

For example, the polymer filter may have a hollow fiber or flat membrane shape. Furthermore, it may be formed on the support according to an additional purpose such as imparting strength or imparting other functionality, but is not limited thereto. As the support, various materials known in the art may be used without limitation.

A third aspect of the present invention has pores having an average size of 0.05 to 10 μm on one surface, and a hydrophilic polymer coated on the other surface, having pores of an average size of 1 to 10 nm on one side, a hydrophilic polymer filter A dehumidifying device is provided.

For example, the dehumidifying device of the present invention may be driven using a vacuum pump, but is not limited thereto.

As described above, the polymer filter of the present invention exhibits an increased water permeation flow rate of 0.2 kg/m ² ·hr or more to achieve the water permeation capacity required for the dehumidifying membrane used in the electrodeposition coating process. The apparatus may be used in an electrodeposition painting process, for example, in a painting process of automobiles or shipbuilding equipment.

For example, the dehumidifying device of the present invention can be used in the painting process of automobiles or shipbuilding equipment. The painting process is the last process in the manufacture of automobiles and shipbuilding equipment, and in order to ensure perfect painting quality, it is essential to maintain the humidity in the workplace at an appropriate level. At this time, if the humidity is not controlled, the defect occurrence rate may significantly increase in the final product. Therefore, in order to improve the production yield, it is necessary to pay special attention to the humidity control of the painting process and the factory performing the same, and for this purpose, it is preferable to provide a dehumidifying device.

Since the polymer filter manufactured by the method of the present invention exhibits an excellent dehumidifying effect, it is possible to provide a dehumidifying device that can be easily operated without using the existing dehumidifying method that requires enormous energy and cumbersome processes, so that it is possible to dehumidify in order to improve quality. It can be usefully used in the painting process of automobiles or shipbuilding equipment that requires

1 is a view showing the surface of a PES porous filter manufactured according to an embodiment of the present invention. (a) and (b) show the front and back sides of the filter, respectively.

Hereinafter, the configuration and effects of the present invention will be described in more detail through examples, but these examples are only exemplary descriptions of the present invention and the scope of the present invention is not limited only to these examples.

Example 1: Preparation of Hydrophilized PES Filter-1

A polymer solution was prepared by mixing 15% by weight of polyethersulfone (PES), 45% by weight of dimethylformamide (DMF), and 40% by weight of diethylene glycol (DEG). The polymer solution was applied to a thickness of 100 μm while maintaining the temperature at 20° C., and left still at 70% relative humidity for 5 minutes, and then immersed in water/DMAc (dimethylacetamide) (80/20 wt%) at 60° C. to form a porous filter. prepared. After drying the porous filter, the front surface of the porous filter with large pores is immersed in a monomer solution in which 0.5 wt% of acrylic acid and 0.005 wt% of an AIBN initiator are dissolved in ethanol for 10 minutes and left at 80° C. for 30 minutes, then water A filter to which hydrophilicity was imparted was prepared by immersion in it.

Example 2: Preparation of Hydrophilized PES Filter-2

A filter to which hydrophilicity was imparted was prepared in the same manner as in Example 1, except that the back side of the porous filter having relatively small pores was immersed in the monomer solution.

Comparative Example 1: Preparation of hydrophilized PES filter-3

A filter to which hydrophilicity was imparted in the same manner as in Example 1, except that a polymer solution containing 15% by weight of PES and 85% by weight of dimethylformamide (DMF) and not containing diethylene glycol (DEG) was used. prepared.

Comparative Example 2: Preparation of hydrophilized PES filter-4

A filter to which hydrophilicity was imparted was prepared in the same manner as in Example 1, except that the porous filter was left still at 50% relative humidity instead of 70%.

Comparative Example 3: Preparation of hydrophilized PES filter-5

A filter to which hydrophilicity was imparted was prepared in the same manner as in Example 1, except that a monomer solution containing 1.2 wt% of acrylic acid was used.

Comparative Example 4: Preparation of hydrophilized PES filter-6

A filter to which hydrophilicity was imparted was prepared in the same manner as in Example 1, except that the step of polymerizing the monomer was omitted.

A polymer solution was prepared by mixing 15% by weight of polyethersulfone (PES), 45% by weight of dimethylformamide (DMF), and 40% by weight of diethylene glycol (DEG). The polymer solution was applied to a thickness of 100 μm while maintaining the temperature at 20° C., and left still at 70% relative humidity for 5 minutes, and then immersed in water/DMAc (dimethylacetamide) (80/20 wt%) at 60° C. to form a porous filter. prepared.

Comparative Example 5: Preparation of hydrophilized PES filter-7

A filter imparted with hydrophilicity was prepared in the same manner as in Example 1, except that the porous filter was immersed in a 0.5 wt% aqueous solution of polyacrylic acid for 10 minutes and then dried instead of being immersed in the monomer solution for polymerization. .

Experimental Example 1: Measurement of physical properties of hydrophilized PES filter

The water permeation rate of the hydrophilized porous filters prepared according to Examples 1 and 2 and Comparative Examples 1 to 5 was measured, and the results are shown in Table 1 below. Specifically, the water permeation flow rate was measured using a flow meter while mounting a porous filter module to be tested in a chamber controlled to 80% relative humidity and sucking in a vacuum with a relative differential pressure of 0.5 bar.

Next, the nitrogen permeability and hydrogen permeability of the prepared hydrophilized porous filters were measured using a flowmeter under 1 atm using 99% oxygen or 99.99% high-purity hydrogen, and the results are shown in Table 1. At this time, as a unit of nitrogen permeability and hydrogen permeability, GPU (gas permeation unit, 10 ^-6 cm ³ /cm ² .sec.cmHg) was used. The degree of hydrophilicity was measured by the contact angle.

division Water permeation flow rate (kg/m2hr) Nitrogen Permeability (GPU) Hydrogen Permeability (GPU) contact angle
(do) Example 1 0.22 3 62 62 Example 2 0.2 2 55 64 Comparative Example 1 0.07 One 15 64 Comparative Example 2 0.12 One 31 65 Comparative Example 3 0.15 2 35 56 Comparative Example 4 0.19 3 40 78 Comparative Example 5 0.15 One 31 75

From the above description, those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention should be construed as being included in the scope of the present invention, rather than the above detailed description, all changes or modifications derived from the meaning and scope of the claims to be described later and their equivalents.

Claims (17)

One surface of the porous polymer filter is immersed in a solution containing a vinyl-based monomer of a polymer including at least one functional group selected from the group consisting of hydroxyl group, carboxyl group, amine group, sulfuric acid group, nitro group, phosphoric acid group, and carbonic acid group and an initiator and polymerization A method of manufacturing a porous polymer filter having a controlled pore size by selectively introducing a polymer coating layer having a hydrophilic functional group on one surface, the method comprising the step of coating the pore surface of a porous polymer by forming a porous polymer.
According to claim 1,
The porous polymer filter is formed by casting a polymer solution containing 8 to 30% by weight of a polymer, 10 to 50% by weight of an additive, and an extra solvent based on the total solution weight to a predetermined thickness, and 0.5 at a relative humidity of 60% or more. After standing for 10 minutes to 10 minutes, and prepared by immersion in a non-solvent of 50 to 80 ℃, the manufacturing method.
3. The method of claim 2,
The polymer is polyethersulfone (PES), polysulfone (PSU), cellulose acetate (cellulose acetate), polyarylene ether sulfone (poly(arylene ether sulfone); PAES), polyarylene sulfone (poly ( arylene sulfone), polyvinyledene fluoride (PVDF), polytetrafluoroethylene, polyethylene, polyimide, polyetherimide, polyamideimide, polyvinyl alcohol, polyacrylonitrile, nylon, polyester, And any one selected from the group consisting of polyketone, or a copolymer of two or more or a mixture thereof, the manufacturing method.
3. The method of claim 2,
The additive is a method for producing a polymer having a molecular weight of 60 to 200,000.
3. The method of claim 2,
The additive is ethylene glycol, or a polymer thereof.
3. The method of claim 2,
The solvent is a single solvent or a mixed solvent of two or more selected from the group consisting of dimethylformamide (DMF), dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide. .
3. The method of claim 2,
The non-solvent is water, glycerol, ethanol, ketones and ethers solvents selected from the group consisting of solvents or mixtures thereof, the manufacturing method.
3. The method of claim 2,
The vinyl-based monomer of the polymer containing the functional group is acrylic acid, vinylsulfonic acid, vinylamine, methacrylic acid, vinyl alcohol, or a mixture thereof, the manufacturing method.
According to claim 1,
The initiator is azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO) or di-tert-butyl peroxide (DEBP), the manufacturing method.
According to claim 1,
The polymerization is carried out by heating to 70 to 100 ℃ and standing for 5 to 60 minutes, the manufacturing method.
A polymer filter hydrophilized on one side, having pores of an average size of 0.05 to 10 μm on one surface, and pores of an average size of 1 to 10 nm by coating the other surface with a hydrophilic polymer.
12. The method of claim 11,
The polymer filter is manufactured by the method of any one of claims 1 to 10, a polymer filter.
12. The method of claim 11,
The dehumidification efficiency is improved due to the hydrophilic polymer coating and pores of a controlled size, a polymer filter.
12. The method of claim 11,
The polymer is polyethersulfone, polysulfone, cellulose acetate, polyaryleneethersulfone, polyarylenesulfone, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polyimide, polyetherimide, polyamideimide, poly Any one selected from the group consisting of vinyl alcohol, polyacrylonitrile, nylon, polyester, and polyketone, or a copolymer of two or more or a mixture thereof, a polymer filter.
12. The method of claim 11,
A polymer filter that has a hollow fiber or flat membrane shape.
A dehumidifying device having a hydrophilic polymer filter on one side, having pores having an average size of 0.05 to 10 μm on one surface, and pores with an average size of 1 to 10 nm coated with a hydrophilic polymer on the other surface.
17. The method of claim 16,
The dehumidifying device will be used in the electrodeposition coating process, the dehumidifying device.

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