KR20190123007A - Manufacturing method of fine dust filter - Google Patents

Abstract

The present invention relates to a method for manufacturing an electrically oriented filter for blocking fine dust, a filter, and a kit. The method comprises: a filter manufacturing step of forming a nanofiber web by electrospinning a fluorine-based polymer solution on a substrate; and a dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter.

Description

MANUFACTURING METHOD OF FINE DUST FILTER}

The present invention relates to a filter for collecting fine dust contained in the air flowing into the room from the outside, including a nanofiber web, and more particularly, by applying an electric field to the filter to enhance the size of the dipole, It relates to a manufacturing method.

The dust floating in the air is divided into Total Dust (TSP) and Particulate Matter (PM) with a particle size of 50 µm or less, of which fine particles are 10 µm or less in diameter (PM 10). Divided into dust and ultra-fine dust with a diameter of 2.5 μm or less (PM 2.5).

In addition, fine dust is generated in the process of burning fossil fuels, such as fumes and automobile exhaust of the factory, mainly composed of harmful substances such as sulfate, nitrate, ammonia and heavy metals. When the nose is breathing through the nose, large dust is filtered through the hair or by the mucus in the nose and throat, but ultra-fine dust is not filtered but penetrates into the body causing various respiratory and cardiovascular diseases.

Accordingly, the importance of the filter device for purifying the contaminated air is becoming more important, and various filter devices are continuously developed to increase the filtration function and efficiency of the filter device. Among them, nanofibers are used as the material of the filter as a material expressing high performance throughout the industry.

Electrospinning technology, which is used in nanofibers to collect fine dust, applies high voltages to polymer solutions or melts and sprays polymer solutions onto negatively charged or ground-charged surfaces. In this process, as the solvent is volatilized, the nanofiber material is laminated on a collector or web in a web or non-woven state to prepare nanofibers. These nanofibers are prepared by adjusting the porosity and pore size according to the diameter and thickness of the fiber on the web or nonwoven fabric. However, the nanofiber web has a problem that the dipole orientation of the polymer constituting the inside is offset by each other, and thus the size of the dipole of the entire nanofiber is reduced to effectively collect fine dust. In addition, it is difficult to remove the collected dust from the filter, there is a problem that increases the filter consumption and difficult to reuse.

The present invention has been made in order to solve the above problems, the object of the present invention is to significantly increase the size of the nano-fiber inner dipole to significantly increase the fine dust collection efficiency filter for fine dust blocking and its manufacturing method and kits. do.

In addition, an object of the present invention is to provide a filter for blocking fine dust that can ensure sufficient visibility during the day.

In addition, an object of the present invention is to provide a fine dust blocking filter excellent in breathability when used as a filter, even when the fine dust is accumulated, the ventilation is maintained relatively high during long-term use.

One aspect of the present invention for achieving the above object is

A filter manufacturing step of forming a nanofiber web by electrospinning a fluorine-based polymer solution on a substrate and

And a dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter.

In one aspect of the invention, the dipole strengthening step may be that the electric field is 50 to 300 kV / cm.

In one aspect of the invention, after the filter manufacturing step, it may further comprise a lamination step of compressing the nanofiber web applied on the substrate.

In one embodiment of the present invention, the fluorine-based polymer is vinylidene fluoride, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, purple It may be a homopolymer or copolymer thereof comprising a monomer selected from fluoro butylethylene, perfluoro methyl vinyl ether, perfluoro ethyl vinyl ether and perfluoro propyl vinyl ether.

In one embodiment of the present invention, the electrospinning may be a tip to collector distance (TCD) of 10 to 30 cm, a scanning speed of 5 to 30mL / hr and a spinning time of 50 to 600 seconds.

In the present specification, TCD means the spinning distance from the nozzle tip to the substrate.

Another aspect of the invention is a substrate; And it may be a fine dust blocking filter comprising an electrically oriented fluorine-based polymer nanofiber web formed on the substrate.

In another embodiment of the present invention, the fine dust blocking filter may be a surface voltage of 3kV to 4.5kV.

In another embodiment of the present invention, the nanofiber web may have a thickness of 1 to 50 ㎛.

In another embodiment of the present invention, the nanofiber web has a light transmittance of 75% or more measured at 600 nm during electrospinning under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 sec spinning time. Can be.

In another embodiment of the present invention, the filter may be a fine dust collection efficiency of 80% or more according to the gravimetric method of ASHRAE STANDARD 52.1.

In another embodiment of the present invention, the nanofibers may be 10 to 500 nm in diameter.

Another aspect of the present invention may be a fine dust blocking filter kit formed by stacking any one of the fine dust blocking filters.

In another aspect of the present invention, the laminate may be formed spaced apart from each other.

In another aspect of the present invention, the electrode may be formed on both end layers of the filter, and the surface voltage may be increased by applying an additional electric field.

The present invention can provide a fine dust blocking filter and a manufacturing method and kit thereof that significantly increases the size of the nanofiber inner dipole significantly improved the fine dust collection efficiency.

In addition, the filter of the present invention has the advantage of ensuring sufficient visibility during the day.

In addition, the present invention maintains a relatively high ventilation even when long-term use, even when the fine dust is accumulated, there is an advantage that excellent ventilation when used as a filter.

In addition, the present invention has the advantage that can be used for a long time because the reusability is high by efficiently removing the collected fine dust in a short time.

1 is a scanning electron microscope (SEM) photograph of the nanofiber web prepared in Examples 1 to 3 of the present invention.
2 is a graph showing the surface voltage in Example 1 and Comparative Example 1 of the present invention.

DETAILED DESCRIPTION Hereinafter, the present invention will be described in more detail with reference to the accompanying examples or embodiments. However, the following specific examples or examples are only one reference for describing the present invention in detail, but the present invention is not limited thereto and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description in the present invention are only for effectively describing specific embodiments and are not intended to limit the present invention.

Also, the singular forms used in the specification and the appended claims may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

Basis Weight of Grammage in the present invention is defined as mass per unit area, ie grams per square meter (g / m ² ) as preferred units.

The inventors of the present invention have found that in providing a filter for blocking fine dust, it is excellent in ventilation during long-term use, visibility is secured, and can effectively block fine dust.

In addition, the manufactured fine dust blocking filter can effectively remove the collected fine dust has found a high reusability and completed the present invention.

Hereinafter will be described in more detail the manufacturing method of the fine dust cut filter according to the present invention, the fine dust cut filter and kit produced through this.

The method for producing a fine dust filter according to the present invention

A filter manufacturing step of electrospinning a fluorine-based polymer solution on the substrate to form a nanofiber web and a dipole reinforcing step of applying a electric field to the filter to reinforce the dipole.

In one aspect of the invention, a nanofiber web is formed by electrospinning a fluorine-based polymer solution on a substrate. Fluorine-based polymers have a significant advantage in dust collection because they can form nanofiber webs as solutions and form excellent chemical resistance, high durability and strong dipoles when an electric field is applied.

The substrate is used as a support or mounting sheet on the collector during electrospinning. In addition, it is possible to supplement the physical properties of the nanofiber web and to improve the handleability. The substrate is not particularly limited as long as the nanofiber web may be formed thereon, but may be a porous substrate or a mesh.

The porous substrate may be selected from a microporous film, a nonwoven fabric, and a woven fabric. The porous substrate may be selected from a polyester, nylon, polyolefin, and cellulose series. In addition, the mesh may be a polyolefin-based mesh, polyester mesh, glass fiber mesh, nylon mesh, steel mesh and aluminum mesh.

The polyolefin may be polyethylene, polypropylene, or the like, but is not limited thereto.

The basis weight of the substrate may be 5 to 100g / m ² , when satisfying the above range, satisfies the physical properties of the filter support, good stiffness may be good workability. Preferably from 10 to 50 g / m ² , more preferably from 15 to 40 g / m ² .

In addition, the basis weight of the nanofiber web may be 0.5 to 10 g / m ² , the nanofiber web and the filter can be manufactured with a small amount of polymer when the above range is satisfied, the mechanical properties and breathability may be good. . Preferably from 0.5 to 5 g / m ² , more preferably from 0.5 to 2 g / m ² .

In one embodiment of the present invention, the fluorine-based polymer is vinylidene fluoride, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, perfluoro It may be a homopolymer or copolymer thereof comprising a monomer selected from butyl ethylene, perfluoro methyl vinyl ether, perfluoro ethyl vinyl ether and perfluoro propyl vinyl ether, preferably vinylidene fluoride and tri It may be a copolymer of fluoroethylene, but is not limited thereto. The fluorine-based polymer may be dissolved in an organic solvent for electrospinning, and examples of the organic solvent may include acetone, N-methyl-2-pyrrolidone (NMP), and dimethylformamide (DMF). ), Chloroform, dimethylsulfoxide, dimethylacetamide (dimethylacetamide, DMAc) and the like may be one or two or more mixtures selected from, but is not limited thereto, preferably acetone and dimethylformamide.

The polymer solution is spun by an electrospinning process. Electrospinning process refers to a process capable of producing nanofibers through a jet of an electrically charged polymer solution and melt. The manufacturing method using the electrospinning is formed between the positive electrode and the negative electrode by the electric field forming portion and the electric field forming portion consisting of a positive electrode, a negative electrode provided to be spaced apart from the positive electrode and a power supply device coupled to the positive electrode and the negative electrode A manufacturing apparatus including a nozzle for spinning a polymer solution in an electric field forming space may be used.

In addition, the nanofiber web may be obtained by forming and stretching a jet by the electric field. The nanofiber web is more uniform, and the smaller the diameter, the better can trap particles of small particle size is suitable as a filter.

In one aspect of the present invention, a tip to collector distance (TCD), which means the spinning distance from the nozzle tip to the substrate, may be 10 to 30 cm, and the spinning time may be 50 to 600 seconds. When satisfying the TCD and spinning time, it is possible to form a uniform and good air permeability nanofiber web. Preferably, the TCD may be 10 to 25 cm, the spinning time may be 70 to 500 seconds, more preferably the TCD may be 10 to 15 cm, the spinning time may be 90 to 500 seconds, but is not limited thereto.

In addition, when performing the electrospinning, the scanning speed of the spinning solution may be 5 to 30 mL / hr. When the scanning speed is as described above, the spinning solution may be continuously discharged to form nanofibers of uniform size, and the spinning solution may be well collected in the collector, thereby improving the productivity of the nanofiber web. Preferably from 10 to 25 mL / hr, more preferably from 15 to 23 mL / hr.

In one aspect of the invention, the spinning temperature may be 5 to 45 ℃ in terms of manufacturing a uniform nanofiber web, the solvent is volatilized to meet the above range to form a nanofiber, thus the strength of the nanofiber web produced May increase. Preferably it may be 10 to 35 ℃, more preferably 15 to 35 ℃.

The content of the fluorinated polymer in the polymer solution may be 0.1 to 0.5 g, preferably 0.2 to 0.4 g, more preferably 0.25 to 0.35 g, per 2.5 mL of solvent in terms of preventing particles and beads from forming. have.

When the electrospinning is performed, the applied voltage may be 5 to 40 kV. When the above range is satisfied, spinning of the spinning solution is smooth and the uniformity of the nanofibers is improved. Preferably from 5 to 20 kV, more preferably from 10 to 13 kV.

In one aspect of the present invention, a dipole reinforcing step of applying an electric field to the filter to reinforce the dipole. When electrospinning the fluorine-based polymer solution, the dipoles are canceled out between the fluorine-based polymers, and thus the dipoles of the entire nanofiber web may be reduced or absent. Therefore, it was found that when the dipole is formed in one direction by passing an external electric field through the filter, fine dust can be effectively collected.

In addition, the dipole reinforcing step may pass an electric field through the substrate and the nanofiber web so that an electric field is formed between the electrodes so that each nanofiber is uniformly arranged along the electric field.

In one aspect of the present invention, the electric field in the dipole reinforcing step may be 50 to 300 kV / cm, the surface voltage is increased due to the uniform arrangement of nanofibers and the dipole size of the entire nanofiber web within the above range can do. Preferably from 50 to 200 kV / cm, more preferably from 50 to 150 kV / cm. However, the strength of the electric field is not limited as long as it can induce dipoles.

In one aspect of the invention, after the filter manufacturing step,

A lamination step of compressing the no-fiber web may be further included.

When performing the lamination step, the nanofiber web is pressed to the substrate, it is preferable to prevent the detachment and damage of the nanofiber web from the substrate. The temperature of the lamination step is not particularly limited as long as it is equal to or more than the softening point of the surface of the substrate or the nanofiber web. As a non-limiting example of the polyester substrate, when laminating the filter at 200 ℃ can be fixed well without damaging the nanofibers.

The lamination method may be a roll-to-roll method, a direct coating method, a printing method, a screen method, or the like, but preferably a roll-to-roll method.

Another aspect of the present invention, the substrate; And a fine dust cut filter including an electrically oriented fluorinated polymer nanofiber web formed on the substrate, wherein the surface voltage of the fine dust cut filter may be 3 kV to 4.5 kV, but is not limited in the range in which the electrical orientation is possible. . In the case of the electro-orientation, the electrostatic attraction between the fine dust and the nanofiber web increases, which greatly improves the particle removal efficiency and does not increase the differential pressure due to the air resistance.

In one aspect of the invention, the thickness of the nanofiber web may be 1 to 50 ㎛. The thickness of the nanofiber web is determined by ASTM D1777-64, and the unit is expressed in '㎛'. When the above range is satisfied, breathability and visibility may increase. Preferably it may be 5 to 35 ㎛, more preferably may be 5 to 30 ㎛ but is not limited thereto.

In one embodiment of the present invention, the nanofiber web may have a light transmittance of 75% or more measured at 600 nm during electrospinning under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 seconds spinning time. If the above range is satisfied, the outdoor view can be optimally secured when applied to the window. Preferably from 75 to 98%, more preferably from 78 to 85%.

In one embodiment of the present invention, the filter may be that the fine dust collection efficiency according to the gravimetric method of ASHRAE STANDARD 52.1 is 80% or more.

When satisfying the above range, since the nanofiber web has a large specific surface area and a small pore size, not only fine dust but also ultrafine dust may be collected with high efficiency, and thus may be suitable for application as a filter. Preferably from 85 to 100%, more preferably from 90 to 100%.

In one aspect of the invention, the nanofibers may have a diameter of 10 to 500 nm. When satisfying the above range, it is possible to have a high specific surface area and to form fine pores, which is effective for collecting fine dust. Preferably from 50 to 300 nm, more preferably from 50 to 200 nm.

In the filter for fine dust blocking, the base material and the fluorine-based polymer are the same as described above in the manufacturing method, and thus redundant description is omitted.

Another aspect of the present invention is a kit, the fine dust filter is formed by stacking. When formed by stacking filters, it is possible to manufacture a large filter can further improve the collection efficiency of fine dust.

In the kit, the fine dust blocking filter laminate may be formed to be spaced apart from each other by a predetermined interval, and the pressure loss may be reduced when spaced apart from each other. The separation distance is not limited as long as it is a value capable of maximizing fine dust collection efficiency, but may be 10 to 20 mm, and preferably 11 to 13 mm.

In one embodiment of the present invention, the filter kit may be an electrode on both end layers, the surface voltage is increased by applying an additional electric field.

In the step of increasing the surface voltage, the surface voltage may be increased by installing a plurality of electrodes in both sides of the filter kit in the axial direction and applying a voltage to the electrodes to form an electric field between the electrodes. When stacking a filter having a surface voltage of 3 kV to 4.5 kV, the surface voltage of the filter kit may be 5 kV to 10 kV, preferably 5 kV to 8 kV, and more preferably 5 kV to 7 kV. By increasing the surface voltage of the filter kit, the fine dust collecting performance may be excellent, and when the reverse voltage is applied, the fine dust collected may be easily removed, and thus reusability may be excellent.

The application of the filter and filter kit is not limited, but may be applied to windows, masks, helmets, automotive air conditioning systems, industrial exhaust filtration systems, and the like, preferably windows and masks.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following Examples and Comparative Examples are only examples for explaining the present invention in more detail, the present invention is not limited by the following Examples and Comparative Examples.

[Measurement Method]

1) Light transmittance measurement

According to ASTM E 424-71 (2007, METHOD A 6.5.2 SELECTED ORDINATES METHOD), the light transmittance at 600 nm was measured using a UV-Vis spectrometer.

2) Fine dust collection efficiency measurement

1% by weight of potassium chloride was dissolved in distilled water, and a particle generator was operated to prepare particles having an average particle diameter of 2.5 mu m. The particles were injected into the nanofibers, and the collection efficiency of potassium chloride was measured according to the gravimetric method of ASHRAE STANDARD 52.1 at a test wind speed of 1.0 m / s and a terminal pressure loss of 76 mmAq.

3) Surface voltage measurement of filter

Surface voltage was measured using electrostatic measuring surface potentiometer model 344 (TREK Inc, Electrostatie voltmeter model 344).

Example 1

0.341 g of PVDF-TrFE (poly (vinylidene fluoride-trifluoroethylene)) (manufactured by Poly K) powder was added to a container containing 1.5 mL of DMF (dimethylformamide) and 1 mL of acetone solution. Was prepared.

After moving the polymer spinning solution to the nozzle block, at 25 ℃ TCD (Tip to collector distance) is 11cm, scanning speed 20mL / hr, applied voltage 12 kV, polyester mesh used as a substrate (16 Mesh, Basis weight: 27.36 g / m ² , density: 25 × 25 bones / inch) was electrospun for 120 seconds.

The prepared substrate and nanofiber web were then passed through an electric field of 100 kV / cm and laminated at 200 ° C. by the roll-to-roll technique to compress the nanofiber web onto the substrate.

Example 2

Except for electrospinning for 240 seconds, it was prepared in the same manner as in Example 1.

Example 3

Except for electrospinning for 480 seconds, it was prepared in the same manner as in Example 1.

Comparative Example 1

Except that the electric field was not passed through the nanofiber web was prepared in the same manner as in Example 1.

Comparative Example 2

Except that the electric field was not passed through the nanofiber web was prepared in the same manner as in Example 2.

Comparative Example 3

Except that the electric field was not passed through the nanofiber web was prepared in the same manner as in Example 3.

In Example 1, nanofiber webs and filters were prepared by electrospinning for 120 seconds, and showed 80% light transmittance at 600 nm, and 90.5% fine dust collection efficiency due to high surface voltage. In addition, in Example 2, a nanofiber web and a filter were manufactured by electrospinning for 240 seconds, and showed 60% light transmittance and 95.6% fine dust collection efficiency at 600 nm. In Example 3, nanofiber webs and filters were prepared by electrospinning for 480 seconds, exhibited 40% light transmittance at 600 nm, and 97.1% fine dust collection efficiency.

Therefore, it was confirmed that as the electrospinning time increases, the fine dust collection efficiency increases due to the small pore size of the nanofiber web. In addition, in Examples 1 to 3, the surface voltage was higher than 4 as the electric field was applied, and thus the fine dust collection efficiency was high. In addition, it was confirmed that even in the long-term use, even though fine dust accumulates, the ventilation is excellent and visibility is sufficiently secured.

In Comparative Examples 1 to 3, a low surface voltage was formed by not passing an electric field through the nanofiber web, and exhibited low fine dust collection efficiency.

Therefore, when the electric field was applied as in the example, it was confirmed that the improved fine dust collection efficiency, high air permeability and visibility in long-term use.

As described above in the present invention has been described by a limited embodiment, but this is only provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments, the present invention is not limited to the common knowledge Those having a variety of modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later belong to the scope of the present invention. .

Claims (15)

A filter manufacturing step of forming a nanofiber web by electrospinning a fluorine-based polymer solution on a substrate and
And dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter. The method of claim 1,
The dipole reinforcing step is a method for producing a fine dust cut filter having an electric field of 50 to 300 kV / cm. The method of claim 1,
After the filter manufacturing step, a fine dust cut filter manufacturing method further comprises a lamination step of pressing the nanofiber web applied on the substrate. The method of claim 1,
The fluorine-based polymer is vinylidene fluoride, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, perfluoro butylethylene, perfluoro A method for producing a fine dust filter, which is a homopolymer or a copolymer thereof comprising a monomer selected from methyl vinyl ether and perfluoro ethyl vinyl ether and perfluoro propyl vinyl ether. The method of claim 1,
The electrospinning method of producing a fine dust filter for TCD is 10 to 30cm, scanning speed is 5 to 30mL / hr and spinning time is 50 to 600 seconds. materials; And
Filter for blocking fine dust comprising an electrically oriented fluorine-based polymer nanofiber web formed on the substrate. The method of claim 6,
The fine dust blocking filter is a fine dust blocking filter having a surface voltage of 3kV to 4.5kV. The method of claim 6,
The nanofiber web is 1 to 50 ㎛ thick dust blocking filter. The method of claim 6,
The nanofiber web has a fine dust blocking filter having a light transmittance of 75% or more at 600 nm during electrospinning under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 sec spinning time. The method of claim 6,
The filter is a fine dust blocking filter having a fine dust collection efficiency of 80% or more according to the gravimetric method of ASHRAE STANDARD 52.1. The method of claim 6,
The fluorine-based polymer is vinylidene fluoride, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutylene, perfluoro butylethylene, perfluoro A filter for blocking dust, which is a homopolymer or copolymer thereof comprising a monomer selected from methyl vinyl ether, perfluoro ethyl vinyl ether, and perfluoro propyl vinyl ether. The method of claim 6,
The nanofiber has a diameter of 10 to 500 nm filter for blocking dust. The fine dust blocking filter kit formed by stacking any one of the fine dust blocking filters selected from claim 6 to claim 12. The method of claim 13,
The stack is fine dust filter kit is formed spaced apart from each other. The method of claim 13,
Electrode is formed on both ends of the filter, the filter kit for fine dust blocking the surface voltage is increased by applying an additional electric field.

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