KR101074359B1 - Filter media of facial mask - Google Patents

Abstract

The present invention relates to a filtration material for a face mask having a structure in which nanofiber webs are laminated, and having a multilayer structure in which nanofiber webs made of nanofibers are laminated in two or more layers, and forming an innermost layer when manufacturing a mask. From (L ₁ ) toward the nanofiber web (Ln) forming the outermost layer in the manufacture of the mask (i) the average size of the micropores formed in the nanofiber webs and (ii) the average of the nanofibers forming the nanofiber web It is characterized in that the diameter increases sequentially.

Since the present invention filters large sized fine dust sequentially, it is possible to secure sufficient voids for breathing, so it is easy to breathe, and at the same time extends the life of the face mask, and is composed of nanofibers, the efficiency of collecting fine dust and bacteria outstanding.

Face mask, filtration material, nanofiber, web, lamination, micro-pores, fine dust

Description

Filter material for face mask {Filter media of facial mask}

The present invention relates to a filtration material for a face mask, and more particularly, nanofiber webs composed of nanofibers of different average diameters are laminated in a certain order, so that the face mask has a long service life, easy to breathe, fine dust and The facial mask is also excellent in the effect of collecting bacteria.

Fine dust, especially yellow sand, has an average diameter of 0.1 ~ 2.5㎛ and causes various lung diseases when inhaled into the human respiratory system.

Recently, as the yellow dust phenomenon is increasing and industrial development increases the number of harmful industrial workplaces, the demand for face masks used for the purpose of blocking bacteria and fine dust is increasing.

Conventionally, the filtration material for face masks has been widely used nonwoven fabrics or laminates thereof made of conventional natural or synthetic fibers having an average diameter of more than 1,000 µm, but the filtration material has micropores present therein such as bacteria and fine dust. Too large to collect the problem of falling bacteria and fine dust collection effect.

In order to solve the above problems, fibers having an average diameter of 1,000 nm or less (hereinafter referred to as "nano fibers") or non-woven fabrics made of ultra-fine fibers or laminates of webs thereof have been used as filtration materials for face masks. .

As described above, the filtration material for the face mask made of nanofibers has excellent efficiency of collecting bacteria and fine dust due to small micropores present therein, but it is inconvenient to breathe due to high pressure loss when using a mask, and thus, bacteria and fine dust. There is a problem that the lack of the ability to collect in order of their size, the micropores are easily blocked despite the short use time, making the wearer's breathing difficult and the service life shortened.

On the other hand, in order to solve the problem, such as breathing inconvenient face mask with a device for supplying compressed air has been proposed, there was a problem that the device is complicated and inconvenient to use.

An object of the present invention is a facial mask having a function of sequential filtering from the large dust to the inner layer from the outer layer of the mask to facilitate breathing and to extend the useful life of the mask, and to have excellent dust and bacteria collection efficiency. It is for providing a filtering material for.

The face mask filtration material according to the present invention has a multilayer structure in which nanofiber webs made of nanofibers are laminated in two or more layers, and the mask is manufactured from a nanofiber web (L ₁ ) forming an innermost layer during mask manufacture. (I) the average size of the micropores formed in the nanofiber webs and (ii) the average diameter of the nanofibers constituting the nanofiber web are sequentially increased toward the outer nanofiber web (Ln). .

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the present invention, a nanofiber is used as a term meaning a fiber having a single yarn fineness of 1,000 nm or less, and a nanofiber web is used as a term meaning a web made of the nanofibers.

As shown in FIG. 1, the present invention is a multilayer structure in which a plurality of nanofiber webs (L ₁ , L ₂ ... Ln) are stacked in two or more layers.

It is preferable that the number of laminated layers is 2-6 layers, but it does not specifically limit in this invention, It is suitably selected according to a use.

1 is a schematic cross-sectional view of a filtration material for a face mask according to the present invention.

Among them, L ₁ is a nanofiber web in contact with the innermost layer, that is, the face part in the manufacture of the mask, Ln is a nanofiber web in contact with the outermost layer, that is, the outside air in the manufacture of the mask.

The present invention is directed toward the nanofiber web (Ln) forming the outermost layer when manufacturing the mask from the nanofiber web (L ₁ ) forming the innermost layer during mask manufacturing (ⅰ) the nanofibers (L ₁ , L ₂ .. The average size of the micropores formed in the Ln), that is, the average size of the micropores formed between the nanofibers, and (ii) the average diameter of the nanofibers constituting the nanofiber webs are sequentially increased.

More specifically, the nanofiber web (L ₂ ) formed directly on the innermost nanofiber web (L ₁ ) than the average size of the micropores in the innermost nanofiber web (L ₁ ) and the average diameter of the nanofibers (L ₂₎ The average size of the micropores and the average diameter of the nanofibers are relatively larger.

Also, the second layer in the inner layer is the average size of the micropores in the nanofiber web (L ₃ ) and the average diameter of the nanofibers in the third layer in the inner layer than the average size of the micropores in the nanofibers (L ₂ ). This is relatively larger.

Mask manufactured when the innermost layer of nano-fiber webs (L ₁₎ as in the fine pores average size P _1, and the second layer, the nano fiber web in the inner layer (L ₂₎ as the average size of the micropores P _2, and the mask manufacturing If the average size of the micropores in the outermost nanofiber web (Ln) is Pn, the following relational formula (I) is established.

In addition, the average diameter of the nanofibers constituting the nanofiber web (L ₁ ) that is the innermost layer at the time of manufacturing the mask is referred to as D ₁ , and the average diameter of the nanofibers constituting the nanofiber web (L ₂ ) which is the second layer in the inner layer is D _2. When the average diameter of the nanofibers constituting the nanofiber web (Ln), which is the outermost layer at the time of mask manufacture, is Dn, the following relational formula (II) is established.

In the present invention, since the relations (I) and (II) are established, bacteria and fine dust larger in size toward the innermost nanofiber web (L ₁ ) from the outermost nanofiber web (Ln) during mask manufacturing Including the first, and gradually to the inner layer is gradually collecting a relatively small bacteria and fine dust.

As a result, there is a margin of micropores in the filtration material, which facilitates breathing and extends the service life of the mask.

Nanofibers constituting the nanofiber webs (L ₁ , L ₂ .... Ln) is composed of polyvinylidene fluoride, polyacrylonitrile, polystyrene or chitosan.

The present invention exhibits a filtration efficiency of 95% or more fine dust having an average diameter of 0.3㎛.

The measuring method of filtration efficiency is mentioned later.

The average size of the micropores in the nanofiber webs (L ₁ , L ₂ .... Ln) is measured by the ASTM F-316-03 method.

The average diameter of the nanofibers constituting the nanofiber webs (L ₁ , L ₂ .... Ln) is preferably 30 ~ 1,000nm, if less than 30nm nanofibers are too thin not only difficult to manufacture but also breathing Breathing is difficult due to friction between the surface of the nanofibers and air, and when the surface area exceeds 1,000 nm, the surface area of the nanofibers decreases, thereby reducing the collection efficiency of bacteria and fine dust.

The average size of the micropores in the nanofiber web (L ₁ , L ₂ .... Ln) is preferably 0.05 ~ 3㎛, if less than 0.05㎛ breathing becomes difficult, if more than 3㎛ Dust collection efficiency is lowered.

The thickness of each of the nanofiber webs (L ₁ , L ₂ ... Ln) is 1 to 10 μm, which is more preferable for improving the filtration efficiency and lowering the exhaust resistance.

Next, look at one example of a method for producing a face mask filtration material according to the present invention.

The face mask filtration material according to the present invention can be prepared by the conventional electrospinning shown in FIG. 3 by repeating the arrangement as shown in FIG. 2 and sequentially performing a plurality of electrospinnings on the same collector 4.

2 is a schematic diagram of an electrospinning apparatus for manufacturing a nanofiber web laminate having a multilayer structure, and FIG. 3 is a schematic diagram of a conventional electrospinning apparatus.

At this time, the first diameter of the nanofiber web (L ₁ ) constituting the innermost layer during the manufacture of the mask, the thinnest average diameter of the nanofiber during the first electrospinning, and the second making the nanofiber web (L ₂ ) constituting the second inner layer In electrospinning, the average diameter of the nanofibers is made relatively thicker than in the first electrospinning, and in the final electrospinning, the average diameter of the nanofibers is made thickest.

Electrospinning was first introduced in Germany in the 1930s as a relatively simple way to produce nanofibers of tens to hundreds of nanometers in diameter. However, the technology of the time was limited to commercialization of this technology, so it was not received attention, and research began again until the 1970s, and full-scale research began only after the 2000s.

Electrospinning applied a high voltage of several thousand to tens of thousands of volts to the polymer solution, and the force of the tangential vector exceeding the surface tension of the solvent was applied from the polymer solution to form a fine polymer jet from the polymer solution. The band advances rapidly toward the object. The jets of polymer jets are then dispersed and scattered back into a number of fine fibers, which have a diameter of tens to hundreds of nanometers.

Electrospinning can be used to produce nanofiber webs as shown in Figure 2 consisting of nanofibers having a thickness of several tens to hundreds of nanometers from a polymer solution, using them for high functional clothing, ultra-precision filters, cell culture materials (scaffold). High performance products, such as) can be obtained.

In order to commercially manufacture a nanofiber web, Korean Patent No. 0412241, Korean Patent No. 0422459, and Korean Patent Publication No. 2005-15610 propose a method of electrospinning a polymer solution through a plurality of nozzles.

Specifically, in the above method, as shown in FIG. 3, the polymer solution is supplied to the plurality of nozzles 3 under high voltage through the metering pump 2, and then a high voltage having a charge opposite to the nozzle is applied. A nanofiber web is produced by electrospinning on a fiber substrate positioned on the hanging collector 4.

The filtration material for a face mask according to the present invention has a filtration efficiency of 95% or more, an exhaust resistance of less than 29.0, and a high filtration efficiency and a low exhaust resistance, which is useful as a filtration material for a face mask.

In general, in order to increase the filtration efficiency, it is necessary to increase the overall thickness or density of the face mask filtration material, so that the exhaust resistance becomes high, but the present invention solves such a conventional problem.

Since the present invention filters large sized fine dust sequentially, it is possible to secure sufficient voids for breathing, so it is easy to breathe, and at the same time extends the life of the face mask, and is composed of nanofibers, the efficiency of collecting fine dust and bacteria outstanding.

Hereinafter, the present invention will be described in detail through examples and comparative examples.

However, the scope of the present invention is not limited by the following examples.

Example  One

First, a polyacrylonitrile resin was dissolved in a mixed solvent of dimethylformamide and methyl ethyl ketone to prepare a solution during polar electrospinning.

An average diameter of 50 nm on the collector 4 through the first electrospinning apparatus, while supplying the electrospinning solution prepared as described above to each of the three conventional electrospinning apparatus as shown in FIG. 3 arranged side by side as shown in FIG. Phosphorous nanofibers were electrospun to prepare an innermost nanofiber web (L ₁ ) having an average size of 0.2 μm of micropores between nanofibers.

Next, the spinning solution was electrospun onto the innermost nanofiber web (L ₁ ) through the second electrospinning apparatus of FIG. 3 to electrospin nanofibers having an average diameter of 100 nm to average the micropores between nanofibers. A second inner layer of nanofiber web (L ₂ ) having a size of 0.8 μm was prepared.

Next, through the third electrospinning apparatus of FIG. 3, the spinning solution was electrospun onto the nanofiber web L ₂ , the second inner layer, with an average diameter of 300 nm and the average of micropores between nanofibers. The outermost nanofiber web (Ln) having a size of 1.2 μm was laminated to prepare a filtration material according to the present invention.

The results of measuring the filtration efficiency and the exhaust resistance of the filtration material manufactured as described above are shown in Table 2.

Example  2 and Comparative Example  One

A filtration material was prepared in the same manner as in Example 1 except for changing the average size of the micropores and the average diameter of the nanofibers in the nanofiber webs (L ₁ , L ₂ , Ln) as shown in Table 1.

The results of measuring the filtration efficiency and the exhaust resistance of the filtration material manufactured as described above are shown in Table 2.

Manufacture conditions division Example 1 Example 2 Comparative Example 1
The innermost nanofiber web (L ₁ ) Average size of micropores
(Μm)
0.2
0.3
1.5 Average diameter of nanofiber
(Nm)
50
60
500
Second inner layer, nanofiber web (L ₂ ) Microporous
Average size
(Μm)
0.8
0.9
0.9 Nanofiber
Average diameter
(Nm)
100
120
120
The outermost nanofiber web (Ln) Microporous
Average size
(Μm)
1.2
1.5
0.3 Nanofiber
Average diameter
(Nm)
300
500
60

Property evaluation result division Filtration efficiency (%) Exhaust resistance Example 1 99% 25.5 Example 2 98% 26.0 Comparative Example 1 89% 30.2

The filtration efficiency and the exhaust resistance were measured by the method of evaluating the filtration efficiency and exhaust resistance of the face filtration mask of the Ministry of Labor Notice No. 2000-15 (2000.5.8).

1 is a schematic cross-sectional view of a filter material for a face mask according to the present invention.

2 is a schematic view of an electrospinning apparatus for manufacturing a multi-layered nanofiber web laminate.

3 is a schematic view of a conventional electrospinning apparatus.

4 is an electron micrograph of the surface of a nanofiber web.

* Explanation of the main parts of the drawings.

a: Nanofiber web forming the innermost layer in direct contact with the face in the manufacture of a mask.

b: Nanofiber web laminated directly on the innermost nanofiber web.

n: Nanofiber web forming outermost layer in direct contact with outside air in mask manufacture

1: Polymer solution main tank 2: Polymer solution supply tank

3: nozzle block 4: collector 5: voltage transfer rod 6: voltage generation

L ₁ : Nanofiber web forming innermost layer in mask manufacturing

L ₂ : Nanofiber web laminated directly above L ₁

Ln: Nanofiber web forming outermost layer when manufacturing mask

Claims (6)

Nanofiber webs composed of nanofibers have a multilayer structure in which two to six layers are laminated, and nanofiber webs (Ln) forming an outermost layer when manufacturing a mask from a nanofiber web (L ₁ ) which forms the innermost layer when manufacturing a mask. (I) an average size of micropores formed in the nanofiber webs and (ii) an average diameter of the nanofibers constituting the nanofiber web sequentially increase in the direction of (i). The filtration material for a face mask according to claim 1, wherein an average diameter of the nanofibers forming the nanofiber webs is 30 to 1,000 nm. The filtering material for a face mask according to claim 1, wherein the average size of the micropores formed in the nanofiber webs is 0.05 to 3 µm. The filter material for a face mask according to claim 1 or 2, wherein the nanofibers are made of one resin selected from polyvinylidene fluoride, polyacrylonitrile, polystyrene, and chitosan. The filtering material for a face mask according to claim 1, wherein each of the nanofiber webs has a thickness of 1 to 10 µm. The filtration material for a face mask according to claim 1, wherein the filtration efficiency of the face mask filtration material is 95% to 99% and the exhaust resistance is 25.5 to 29.0.

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