KR20190123010A - Manufacturing method of fine dust filter - Google Patents

Abstract

The present invention relates to a method for manufacturing an electrically oriented fine dust blocking filter manufactured by comprising: a filter manufacturing step of electrospinning a polymer solution containing nylon 11 on a substrate to form a nanofiber web; and a dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter and to a filter and a kit. By significantly increasing the size of the dipole inside the nanofiber, the fine dust collection efficiency is dramatically increased.

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 to a filter and a method of manufacturing the improved collection efficiency.

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 for nanofibers to collect fine dust, applies high voltage to polymer solutions or melts, and polymer solutions are sprayed 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.

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 having excellent natural breathability compared to other nylon, even if the fine dust is accumulated, the increase ratio of the differential pressure generated before and after the filter in the long-term use is relatively low.

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

A filter manufacturing step of forming a nanofiber web by electrospinning a polymer solution containing nylon 11 on the 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, after the filter manufacturing step, it may be prepared by further comprising a lamination step of pressing the nanofiber web applied on the substrate.

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

In one embodiment of the present invention, the nanofiber web may have a tip to collector distance (TCD) of 10 to 30 cm, a scanning speed of 5 to 30 mL / 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 a nanofiber blocking filter including a nanofiber web containing an electrically oriented nylon 11 formed on the substrate.

In another embodiment of the present invention, the surface voltage of the fine dust blocking filter may be 60 to 100V.

In one embodiment of the present invention, the nanofiber web is 11cm in TCD, the scanning speed is 20mL / hr and the spinning time when the electrospinning conditions, 120 seconds, the filter may have a pressure difference between the front end and the rear end of 40Pa or less.

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

In one embodiment of the present invention, the nanofiber web may have a light transmittance of 80% or more measured at a wavelength of 600nm during electrospinning at a condition of 11cm TCD, 20mL / hr scan rate and 120 seconds spinning time .

In one 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 one aspect of the invention, the nanofibers may be of 10 to 500 nm in diameter.

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

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

In another embodiment 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 has a relatively low increase ratio of the differential pressure generated before and after the filter during long-term use, even though fine dust is accumulated, there is an advantage of excellent natural breathability compared to other nylon.

In addition, the present invention has the advantage that can be used for a long time to reuse the fine dust collected in the filter efficiently in a short time efficiently.

1 is a scanning electron microscope (SEM) photograph of the nanofiber web prepared in 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 is defined herein as mass per unit area, ie grams per square meter (g / m ² ) as preferred units.

In the present specification, the pressure drop means the absolute value of the initial pressure difference between the front and rear ends of the filter.

The inventors of the present invention, in providing a filter for blocking fine dust, found that the light transmittance is maintained even after collecting fine dust by containing nylon 11 in the filter, having excellent natural breathability and effectively blocking fine dust. It was.

In addition, it was found that the manufactured fine dust blocking filter ensures visibility and has a low increase in the differential pressure. In addition, by applying an electric field to the filter, it is possible to effectively remove the collected fine dust, thus finding a high reusability to complete 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 forming a nanofiber web by electrospinning a polymer solution containing nylon 11 on the substrate and

A dipole reinforcement step of applying an electric field to the filter to reinforce the dipole.

In one aspect of the invention, the polymer solution containing nylon 11 is electrospun on a substrate to form a nanofiber web. Nylon 11, unlike other polyamides, can form strong dipoles when an electric field is applied. Therefore, it was found that the collection efficiency of fine dust increases due to the strong dipole.

The content of nylon 11 in the polymer solution may be 1 to 10% by weight. When the above range is satisfied, it is suitable as an electrospinning solution, and the nanofiber web is easily manufactured. Preferably from 2 to 6% by weight, more preferably from 3 to 6% by weight.

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 can 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 0.1 to 10 g / m ² . When satisfying the above range can be produced a nanofiber web and filter with a small amount of polymer, excellent mechanical properties and good air permeability. Preferably from 0.5 to 3 g / m ² , more preferably from 0.5 to 2 g / m ² .

The nylon 11 may be dissolved in a solvent for electrospinning, and the solvent may be phenol, formic acid, sulfuric acid, m-cresol, thifluoroacetic & hydride / dichloromethane, N-methylmorpholine N-oxide. One or two selected from chloroform, tetrahydrofuran, aliphatic ketone group, aliphatic hydroxyl group, aliphatic compound group, glycol group, halogen compound group, aromatic compound group, aliphatic ring compound group, ester group, aliphatic ether group and amide The mixture may be, but is not limited to.

The aliphatic ketone group may be one or a mixture of two or more of methyl isobutyl ketone and methyl ethyl ketone.

The aliphatic hydroxyl group may be one or a mixture of two or more selected from m-butyl alcohol, isobutyl alcohol, isopropyl alcohol, methyl alcohol and ethanol.

The aliphatic compound group may be one or a mixture of two or more selected from hexane, tetrachloroethylene and acetone.

The glycol group may be one or a mixture of two or more selected from propylene glycol, diethylene glycol and ethylene glycol.

The halogen compound group may be one or a mixture of two or more selected from trichloroethylene, dichloromethane and the like.

The aromatic compound group may be one or a mixture of two or more selected from toluene, xylene and the like.

The aliphatic ring compound group may be one or a mixture of two or more selected from cyclohexanone and cyclohexane.

The ester group may be one or a mixture of two or more selected from n-butyl acetate and ethyl acetate.

The aliphatic ether group may be one or a mixture of two or more selected from butyl cello salb, acetic acid 2-ethoxyethanol, 2-ethoxyethanol and the like.

The amide may be one or a mixture of two or more selected from dimethylformamide and dimethylacetamide.

One non-limiting example of a solvent can be a mixture of formic acid and dichloromethane.

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, a 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 it can collect particles having a small particle diameter is suitable as a filter.

In one aspect of the invention, the tip to collector distance (TCD), which means the distance from the tip to the substrate, may be between 10 and 30 cm, and the spin time may be between 50 and 600 seconds. When the TCD and the spinning time are satisfied, it is possible to form a nanofiber web having a uniform and good visibility of the filter and having good mechanical properties. Preferably the TCD is 10 to 25 cm, the spinning time may be 50 to 500 seconds, more preferably the TCD may be 10 to 18 cm, the spinning time may be 100 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 25 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 ℃.

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 30 kV, more preferably from 10 to 25 kV.

In one aspect of the invention, the method for producing a fine dust filter includes a dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter. When the polymer solution containing nylon 11 is electrospun, dipoles may decrease due to hydrogen bonding of amide groups in nylon 11. In addition, due to spontaneous polarization inside the nylon 11, the direction of the dipole moment is directed in an arbitrary direction, thereby reducing the dipole. Therefore, the filter was passed through the electric field, it can be seen that if the dipole is formed in one direction inside the nanofiber web can effectively collect fine dust.

In addition, the dipole reinforcing step is to install a plurality of electrodes in the axial direction on both sides of the nanofiber web, by applying a voltage to the electrode to form an electric field between the electrodes, each nanofiber is uniformly arranged along the electric field Be sure to

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.

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.

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 the nanofibers and the dipole size of the entire nanofiber web within the above range 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.

Another aspect of the present invention, the substrate; And a nanofiber web comprising a nanofiber web containing an electrically oriented nylon 11 formed on the substrate, wherein the surface voltage of the microdust blocking filter may be 60V to 100V, but limited in a range in which electrical orientation is possible. It doesn't work. 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 lowers the ratio of the increase of the differential pressure at the front and rear of the filter due to air resistance.

In one embodiment of the present invention, the nanofiber web may have a differential pressure between the front end and the rear end of 40 Pa or less when the electrospinning is performed under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 seconds spinning time. Despite the accumulation of fine dust in the filter within the above range, the increase rate of the differential pressure during long-term use is low, it is good to increase the natural ventilation. Preferably 5 to 40 Pa, more preferably 15 to 35 Pa.

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, the air permeability and visibility of the filter 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 80% or more measured at 600 nm during electrospinning under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 sec spinning time. have. If the above range is satisfied, the outdoor field of view can be optimally secured even in long-term use when the filter made of nanofiber web is applied to the window. Preferably it may be 80 to 90%, more preferably may be 80 to 85%, but is not limited thereto.

In one aspect of the present invention, the filter may have a fine dust collection efficiency of 80% or more according to the gravimetric method of ASHRAE STANDARD 52.1. If the above range is satisfied, the nanofiber web has a large specific surface area and a small pore size, so that it can be used for a long time, and not only fine dust but also ultrafine dust can be efficiently removed in a short time. Preferably from 80 to 98%, more preferably from 80 to 96%.

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 above description is 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 fine dust collection efficiency may be increased 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 filters having a surface voltage of 60 V to 100 V, the surface voltage of the filter kit may be 1 kV to 6 kV, preferably 3 kV to 5 kV, and more preferably 3 kV to 4 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.

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), light transmittance was measured at a wavelength of 600 nm 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 an electrostatic measuring surface potentiometer model 344 (TREK Inc, Electrostatie voltmeter model 344).

4) Differential pressure measurement at the front and rear of the filter

The filter was set in a circular holder having an effective area of 16 cm ² , and gas was passed through the set filter at a wind speed of 0.35 m / s. Differential pressure before and after filter filtration was measured with a differential pressure gauge.

Example 1

Nylon 11 (Sigma Aldrich, T _m = 198 ° C., T _g = 46 ° C.) was added and dissolved in a container in which a formic acid and a dichloromethane solvent were mixed at a 1: 1 weight ratio to 4% by weight of the total polymer solution. The 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 20 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 to prepare a nanofiber web having a thickness of 20 μm.

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 for using nylon 6 instead of nylon 11 was prepared in the same manner as in Example 1.

Comparative Example 2

Except for using nylon 6 instead of nylon 11 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 Examples 1 to 3, nanofiber webs and filters were prepared by varying the electrospinning times, respectively. As a result, it was confirmed that as the spinning time increases, the surface voltage increases and the fine dust collection efficiency increases. In addition, it was confirmed that sufficient visibility was secured from the light transmittance value. In addition, the differential pressure is also low after the increase of the differential pressure even after collecting the fine dust, high natural ventilation.

On the other hand, in the case of Comparative Examples 1 to 2, the fine dust collection efficiency and light transmittance were significantly reduced compared to Examples 1 to 2 with the same spinning time. In addition, in the comparative example, it was confirmed that the long-term use of the filter was difficult because the pressure difference was relatively high.

In addition, in the case of Comparative Example 3, the light transmittance and the differential pressure did not change significantly compared with Example 3 of the same spinning time, but it was confirmed that the surface voltage is significantly low and the fine dust collection efficiency accordingly.

Therefore, in Examples 1 to 3, it was confirmed that as the electrospinning time increases, the fine dust collection efficiency increases as the surface voltage increases due to the small pore size of the nanofiber web and the strong dipole of nylon 11 due to the additional electric field. In addition, despite the accumulation of fine dust, the light transmittance was relatively high, and the increase ratio of the differential pressure was relatively low.

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 (14)

A filter manufacturing step of forming a nanofiber web by electrospinning a polymer solution containing nylon 11 on the substrate and
And dipole reinforcing step of reinforcing the dipole by applying an electric field to the filter. 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,
In the dipole reinforcing step, the electric field is 50 to 300kV / cm of the method for producing a fine dust filter. The method of claim 1,
The nanofiber web has a TCD of 10 to 30cm, a scanning speed of 5 to 30mL / hr and a spinning time of 50 to 600 seconds, a method for producing a fine dust filter. materials; And
Nanofiber web containing electrically oriented nylon 11 formed on the substrate
Fine dust blocking filter comprising a. The method of claim 5,
The fine dust blocking filter is a fine dust blocking filter having a surface voltage of 60 to 100V. The method of claim 5,
The nanofiber web is 11cm TCD, scanning speed 20mL / hr, and spinning time when the electrospinning conditions 120 seconds, the filter is a filter for blocking fine dust that the differential pressure between the front and rear ends 40Pa or less. The method of claim 5,
The nanofiber web has a thickness of 1 to 50 ㎛ filter for blocking dust. The method of claim 5,
The nanofiber web has a fine dust blocking filter having a light transmittance of 80% or more measured at a wavelength of 600 nm during electrospinning under conditions of 11 cm TCD, 20 mL / hr scanning speed, and 120 sec emission time. The method of claim 5,
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 5,
The nanofiber has a diameter of 10 to 500 nm filter for fine dust blocking. The fine dust blocking filter kit is formed by stacking any one of the fine dust blocking filter selected from claim 5 to claim 11. The method of claim 12,
The stack is fine dust filter kit is formed spaced apart from each other. The method of claim 12,
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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