KR20200028741A - Multi-layered filter element for mask and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a multilayer filter member which comprises: a porous base layer having a pressure loss of 0.1 to 2.0 Pa; and a nanofiber layer provided on the porous base layer and made of a nanofiber with the average diameter of 10 to 60 nm. According to the present invention, it is possible to economically provide the multilayer filter member having excellent collection efficiency and low pressure loss.

Description

Multi-layer filter member for mask and its manufacturing method {MULTI-LAYERED FILTER ELEMENT FOR MASK AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a multilayer filter member and a method for manufacturing the same, and more specifically, by including a porous base layer having a pressure loss of 0.1 to 2.0 Pa and a nanofiber layer in the form of a nonwoven fabric composed of nanofibers having an average diameter of 10 to 60 nm. The present invention relates to an economical multilayer filter member having excellent collection efficiency and low pressure loss, and a manufacturing method thereof.

With the development of the industry, the pollution level in the residential area as well as the industrial area, as well as urban concentration and the rapid supply of automobiles, is gradually becoming serious, and furthermore, the entire area is contaminated with fine dust by the yellow dust generated from the mainland China. have. These fine dust can cause respiratory and skin-related diseases.

Accordingly, various air purifiers for purifying air are rapidly spreading to various large buildings and industrial sites, as well as to general homes, and various types of masks are provided to prevent inhalation of fine dust when going out.

An air filter for filtering fine dust must be included in the air purifier or mask as described above. Conventional air filters are simply manufactured to have fine pores so that air can pass through, but are configured not to pass dust over a certain size, and are generally configured to determine the filtration rate according to the pore size. In the case of such an air filter, the smaller the pore size is, the more fine dust it can filter out.

However, in order to manufacture the air filter with a small pore size, there are disadvantages in that manufacturing costs are very high as well as manufacturing difficulties and technical limitations. In addition, the smaller the pores of the air filter, the higher the filtration performance to filter out dust, but the lower the air permeability, the lower the usability. For example, in the case of manufacturing a mask with an air filter having very small air gap, the pressure loss is high, so a user wearing the mask has a disadvantage that it is impossible to wear the mask for a long time because it becomes very difficult to breathe.

As a method for solving the above problems, a method of manufacturing an air filter capable of increasing the filtering performance while maintaining the size of the pores above a certain size is proposed in Patent Document 1 (Domestic Registration No. 10-1808115). It has been done. The air filter according to Patent Document 1 is composed of a nonwoven fabric filter fabric and an adhesive applied to one surface of the filter fabric, and the adhesive is selected as an adhesive material that maintains a gel state when curing is completed. According to Patent Document 1, since the pressure-sensitive adhesive that maintains a gel state continuously has adhesive force, fine dust smaller than the pores of the filter fabric does not pass, and thus has an effect of being adhered to the pressure-sensitive adhesive. It is stated that it is possible to provide an air filter that can effectively filter fine dust while securing it.

However, the amount of fine dust adhering to the pressure-sensitive adhesive is continuously increased over time, and accordingly, the collection efficiency decreases when used for a long time. In addition, if some of the large amount of fine dust attached to the adhesive is inhaled into the body during the breathing process, it may cause problems such as respiratory diseases. Moreover, in the case of the mask to which the filter was applied, when washing with water, the adhesive strength of the pressure-sensitive adhesive drops rapidly, and the collection efficiency can be significantly reduced.

KR 101808115 B

The problem to be solved by the present invention is to provide a multilayer filter member having excellent collection efficiency and low pressure loss even for a long period of use.

Another problem to be solved by the present invention is to provide an economical method capable of manufacturing the multilayer filter member.

In order to solve the above problems, the present invention is a porous base layer having a pressure loss of 0.1 ~ 2.0 Pa; And it is provided on the porous substrate layer, the average diameter of 10 ~ 60 ㎚ nano-fiber layer of a non-woven fabric made of nano-fiber; provides a multi-layer filter member comprising a.

The porous substrate layer may include at least one selected from the group consisting of a polyurethane-based porous body, a polyethylene terephthalate-based porous body, a polypropylene-based porous body, and a nylon-based porous body.

The nanofiber layer may have a three-dimensional network structure, and the thickness of the nanofiber layer is preferably 1 to 20 μm.

The nanofiber layer may be a spunbond nonwoven fabric.

The nanofiber layer may be a freestanding film.

The nanofibers constituting the nanofiber layer are in the group consisting of polypropylene (PP), polyethersulfone (PES), polyethylene terephthalate (PET), polyethylene and nylon. It can be obtained from more than one selected polymer.

An adhesive layer may be further provided between the porous substrate layer and the nanofiber layer. The adhesive layer may include one or more binders selected from the group consisting of nanofiber type binders and liquid binders. Furthermore, a material constituting the adhesive layer may be further provided in the porous base layer and the nanofiber layer. Specifically, the material constituting the adhesive layer is diffused in the adjacent porous substrate layer and the nanofiber layer by fixing the porous substrate layer, the binder, and the nanofiber layer sequentially by heat pressing, and fixing them. I can do it. Through this process, the material constituting the adhesive layer may be coated on the surface of the pores of the porous substrate layer and the surface of the nanofibers of the nanofiber layer.

The binder may include a polymer having a melting point of 100 to 300 ° C, preferably the binder is a group consisting of a polyurethane-based binder, a polyethylene-based binder, a polypropylene-based binder, a polyester-based binder and a polyvinylidene fluoride-based binder It may include more than a kind selected from.

The multilayer filter member according to the present invention may further include a protective sheet provided on the nanofiber layer. The protective sheet may be attached to the nanofiber layer through an adhesive layer as described above.

On the other hand, the present invention provides a method of manufacturing the above-described multi-layer filter member, wherein the manufacturing method comprises: (1) preparing a porous base layer having a pressure loss of 0.1 to 2.0 Pa; And (2) forming a nanofiber layer provided with nanofibers having an average diameter of 10 to 60 nm in a nonwoven fabric on the porous substrate layer prepared according to step (1).

The step (2) is a step of spinning a polymer solution; And spraying compressed air in a direction perpendicular to the spinning direction to form the polymer solution as a non-woven nanofiber layer.

A step (1a) of forming an adhesive layer in at least a portion between the porous base layer and the nanofiber layer may be further included.

In addition, the porous substrate layer, the adhesive layer and the nano-fiber layer may further include the step (2a) of heat-pressing the laminate is sequentially provided.

In step (1a), an adhesive layer may be formed on at least a portion of one surface of the porous substrate layer, and the nanofiber layer may be formed on one surface of the porous substrate layer provided with the adhesive layer. Alternatively, the step (1a) may be to form an adhesive layer on at least a part of one surface of the formed nanofiber layer, and to laminate it on the porous substrate.

By the step (2a), the material constituting the adhesive layer is diffused in the adjacent porous substrate layer and the nanofiber layer, and is coated on the surface of the pores of the porous substrate layer and the nanofiber surface of the nanofiber layer, and the The porous substrate layer and the nanofiber layer may be fixed to each other.

The temperature at the time of the heat pressing in the step (2a) is 70 ~ 350 ℃, the pressure is preferably 50 ~ 100 Pa.

The method of manufacturing a multilayer filter member according to the present invention may further include providing a protective sheet on the nanofiber layer.

In addition, the present invention provides a nanofilter or mask comprising the above-described multi-layer filter member.

According to the present invention, by including a nano-fiber layer in the form of a non-woven fabric made of nano-fibers having a pressure loss of 0.1 ~ 2.0 Pa porous substrate layer and an average diameter of 10 ~ 60 ㎚ multi-layer filter member with excellent collection efficiency and low pressure loss Can provide.

In addition, the multi-layer filter member according to the present invention may include a thin nanofibrous layer having a thickness of several μm, so it is light and flexible and can be effectively applied to a nano filter or a mask. In particular, when applied to a mask, the thickness variation due to mounting of the multi-layer filter member is hardly felt, thereby minimizing the wearer's rejection.

Moreover, when the adhesive layer according to the present invention is further included between the porous substrate layer and the nanofiber layer, a multilayer filter member that can be reused after washing with water can be provided.

In addition, according to the present invention, in the process of manufacturing a nanofiber layer, it is possible to easily mass-produce nanofibers having an average diameter of 10 to 60 nm by using compressed air injection.

1 is a cross-sectional view schematically showing the structure of a multilayer filter member according to an exemplary embodiment of the present invention.
2 is a cross-sectional view schematically showing the structure of a multilayer filter member according to an exemplary embodiment of the present invention.
3 is a scanning electron microscope (SEM) image of a porous substrate layer according to an exemplary embodiment of the present invention.

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

In the present specification, when a part “includes” a certain component, this means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, the present invention will be described in detail.

The multi-layer filter member according to the present invention is an air filter member for filtering fine dust in the air, and has a small size pore to effectively filter even nano-sized fine particles, but also increases the thickness of the filter to minimize pressure loss. It is composed of thin, but the biggest feature in the configuration is that it is configured to be very simple in structure and very easy to manufacture.

Specifically, the multilayer filter member includes a porous base layer having a pressure loss of 0.1 to 2.0 Pa; And a nanofiber layer in the form of a nonwoven fabric made of nanofibers having an average diameter of 10 to 60 nm, provided on the porous substrate layer. 1 is a cross-sectional view schematically showing a structure of a multilayer filter member according to an exemplary embodiment of the present invention.

First, looking at the porous substrate layer, it shows a low pressure loss in the range of 0.1 to 2.0 Pa as described above. Here, the pressure drop (Pressure Drop) refers to a pressure difference generated between the front end and the rear end of the filter when air passes through the filter. When a mask using a filter in which the filter member having a large pressure loss is stacked is worn There is a disadvantage that the wearer's breathing becomes difficult.

The porous substrate layer may include at least one porous body selected from the group consisting of a polyurethane-based porous body, a polyethylene terephthalate-based porous body, a polypropylene-based porous body, and a nylon-based porous body, and may preferably be a polyurethane-based porous body. Since the polyurethane porous body has a low pressure loss and a constant pressure, it is possible to ensure uniformity of the nanofilter when trapping fine particles in the air. Specifically, FIG. 3 shows a polyurethane porous body having a pressure loss of 1.3 Pa.

The porous substrate layer serves to prevent passage of relatively large fine particles (contaminants), and it is possible to suppress a phenomenon in which a part of the nanofilter is blocked by the fine particles.

In addition, the nanofiber layer provided on the porous substrate layer has a nonwoven fabric shape made of nanofibers having an average diameter of 10 to 60 nm. The nanofibers are obtained by spraying high-speed, high-temperature compressed air to a polymer solution spun through a nozzle in a spinning process, stretching of the polymer solution spun by the spraying is performed, and an average of 60 nm or less is obtained through this stretching process. Nanofibers having a diameter can be obtained. Then, a nanofiber layer having a three-dimensional network structure may be formed through the spinning process and the compressed air injection process.

In the case of a nanofiber layer made of nanofibers having an average diameter range as described above, even if it is composed of one layer, it may exhibit excellent trapping effect, but there is a fear that the pressure loss may increase. This can be solved by making the thickness of the nanofiber layer thin, and the thickness of the preferred nanofiber layer in consideration of the pressure loss may be 1 to 20 μm. When the average diameter of the nanofibers and the thickness of the nanofiber layer are as described above, it is possible to provide a nanofiber layer exhibiting a high collection efficiency of 93% or more for fine particles having a particle diameter of 300 nm, and the pressure loss of the nanofiber layer Showed less than 40 Pa.

The nanofiber layer may be a spunbond nonwoven fabric. The spunbond non-woven fabric is a kind of non-woven fabric made by bonding by applying heat after spinning, and has excellent strength and durability, and low manufacturing cost.

The nanofiber layer may be a freestanding film. Here, the self-supporting film refers to a film capable of maintaining its shape as a film itself even if no other support is present. For example, the nano-fiber layer according to the present invention can be made of a vacuum film having a thickness on the order of several μm by itself, and can exhibit a single sound and heat insulating effect.

The nanofiber is obtained from at least one polymer selected from the group consisting of polypropylene (PP), polyethersulfone (PES), polyethylene terephthalate (PET), polyethylene and nylon. Can be obtained, preferably from polypropylene or polyethersulfone.

In the multilayer filter member according to the present invention, an adhesive layer may be further provided between the porous base layer and the nanofiber layer. Specifically, the adhesive layer may be provided on at least a portion between the surface of the porous substrate layer facing each other and the nanofiber layer. 2 schematically shows a structure of a multilayer filter member according to an exemplary embodiment of the present invention including the adhesive layer.

The adhesive layer may include one or more binders selected from the group consisting of nanofiber type binders and liquid binders. The binder may include a polymer having a melting point of 100 to 300 ° C, preferably selected from the group consisting of polyurethane-based binders, polyethylene-based binders, polypropylene-based binders, polyester-based binders, and polyvinylidene fluoride-based binders. It may include the above.

The adhesive layer may be provided between the porous base layer and the nanofiber layer. In addition, a material constituting the adhesive layer may be further provided in the porous substrate layer and the nanofiber layer.

As the porous substrate layer, the adhesive layer, and the nanofiber layer are sequentially stacked and stacked, the binder in the adhesive layer melts and diffuses to the pore surface of the porous substrate layer and the nanofiber surface of the nanofiber layer. The porous substrate layer and the nanofiber layer may be fixed to each other by being coated.

That is, the adhesive layer may mean a layer formed through a heat-pressing process, or may mean a diffusion and coated region of a material constituting the adhesive layer by the heat-pressing.

The multi-layer filter member having the nanofiber layer fixed to the porous base layer via the adhesive layer in the same manner as above can be reused after washing with water, and the collecting efficiency of the filter does not decrease even after repeated washing.

The multilayer filter member according to the present invention may further include a protective sheet provided on the nanofiber layer. At this time, the protective sheet may be attached to the nanofiber layer via an adhesive layer, and the adhesive layer may be obtained from a binder as described above.

The protective sheet may be formed on the nanofiber layer to prevent the nanofiber layer from being damaged or the nanofiber layer contacting the wearer's skin during the process of applying the multi-layer filter member to the nanofilter or mask. . The protective sheet may be formed of at least one selected from the group consisting of polyethylene-based fibers, polypropylene-based fibers, and polyethylene terephthalate-based fibers.

Meanwhile, the present invention provides a method for manufacturing the multilayer filter member. The manufacturing method includes the steps of (1) preparing a porous base layer having a pressure loss of 0.1 to 2.0 Pa; And (2) forming a nanofiber layer provided with nanofibers having an average diameter of 10 to 60 nm in a nonwoven fabric on the porous substrate layer prepared according to step (1).

The step (2) is a step of spinning a polymer solution; And spraying compressed air in a direction perpendicular to the spinning direction to form the polymer solution as a non-woven nanofiber layer.

According to an exemplary embodiment of the present invention, the compressed air may be injected through an air filter nozzle and have a high-speed high-temperature air flow. The high-speed, high-temperature air serves to draw the polymer solution to be spun. The polymer solution subjected to the stretching process may be made of nanofibers having an average diameter of 10 to 60 nm. According to the present invention, it is possible to stably mass-produce nanofibers having a desired average diameter through the above-described process, and the process is very economical.

The nanofibers subjected to the stretching process may be stacked on a conveyor or the like and formed into a non-woven nanofiber layer.

In addition, the method of manufacturing a multi-layer filter member according to the present invention may further include a step (1a) of forming an adhesive layer on at least a portion of the area between the porous base layer and the nanofiber layer.

The step (1a) of forming the adhesive layer may be exemplified by two methods. In the first method, an adhesive layer is formed on at least part of one surface of the porous substrate layer, and on one surface of the porous substrate layer provided with the adhesive layer. It may be to form the nano-fiber layer. In addition, in the second method, an adhesive layer may be formed on at least part of one surface of the formed nanofiber layer, and it may be laminated to the porous substrate. In addition to the above two methods, if the method of fixing the nanofiber layer to the porous substrate layer using the binder, it can be used without limitation as a method of forming an adhesive layer according to the present invention.

Furthermore, the method of manufacturing a multi-layer filter member according to the present invention may further include the step (2a) of heat-pressing a laminate in which the porous substrate layer, the adhesive layer and the nanofiber layer are sequentially provided.

By the heat pressing according to the step (2a), as described above, the material constituting the adhesive layer is diffused in the porous substrate layer and the nanofiber layer, and the porous substrate layer and the nanofiber layer can be fixed to each other.

The temperature at the time of the heat-pressing of the step (2a) may be 70 to 350 ° C. In this case, since the binder can be melted without damaging the porous base layer and the nanofiber layer, the fixing effect can be maximized, which is preferable. . As such a binder, one or more selected from the group consisting of polyurethane-based binders, polyethylene-based binders, polypropylene-based binders, polyester-based binders, and polyvinylidene fluoride-based binders may be used.

The pressure during the heat pressing may be 50 to 100 Pa, in which case the binder diffuses into the porous substrate layer and the nanofiber layer without damaging the porous substrate layer and the nanofiber layer, and can attach them to each other. have.

In addition, the method of manufacturing a multilayer filter member according to the present invention may further include the step of providing a protective sheet on the nanofiber layer. At this time, the material of the protective sheet is as described above.

In addition, the present invention provides a nanofilter or mask comprising the above-described multi-layer filter member. The nanofilter or mask provided in this way has a collection efficiency of 99.97% or more and a pressure loss of 25 Pa or less for fine particles having a particle diameter of 100 nm. In addition, it is very light, has excellent flexibility, has low manufacturing cost, and can be reused after washing with water.

The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited to the specific embodiments, and should be interpreted by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Claims (22)

Porous substrate layer with a pressure loss of 0.1 to 2.0 Pa; And
It is provided on the porous substrate layer, the average diameter of 10 ~ 60 ㎚ nano-fiber layer of a non-woven fabric made of nano-fiber; containing, multi-layer filter member. The method according to claim 1,
The porous base layer comprises a polyurethane-based porous body, a polyethylene terephthalate-based porous body, a polypropylene-based porous body and a nylon-based porous body. The method according to claim 1,
The nano-fiber layer is characterized in that it has a three-dimensional network structure, a multi-layer filter member. The method according to claim 1,
The thickness of the nano-fiber layer is characterized in that 1 to 20 ㎛, multi-layer filter member. The method according to claim 1,
The nanofiber layer is a spun-bonded nonwoven fabric, characterized in that the multi-layer filter member. The method according to claim 1,
The nanofiber layer is a self-supporting film, characterized in that the multilayer filter member. The method according to claim 1,
The nanofiber is obtained from one or more polymers selected from the group consisting of polypropylene (PP), polyethersulfone (PES), polyethylene terephthalate (PET), polyethylene and nylon. Multi-layer filter member, characterized in that. The method according to claim 1,
A multi-layer filter member, characterized in that an adhesive layer is further provided between the porous base layer and the nanofiber layer. The method according to claim 8,
The adhesive layer is a multi-layer filter member, characterized in that it comprises at least one kind selected from the group consisting of a binder in the form of a nanofiber and a liquid binder. The method according to claim 8,
Multi-layer filter member, characterized in that the material constituting the adhesive layer is further provided in the porous base layer, and the nanofiber layer. The method according to claim 9,
The binder, characterized in that it comprises a polymer having a melting point of 100 ~ 300 ℃, multi-layer filter member. The method according to claim 9,
The binder is a multi-layer filter member, characterized in that it comprises at least one kind selected from the group consisting of polyurethane-based binders, polyethylene-based binders, polypropylene-based binders, polyester-based binders and polyvinylidene fluoride-based binders. The method according to claim 1,
A multilayer filter member, characterized in that a protective sheet is further provided on the nanofiber layer. (1) preparing a porous base layer having a pressure loss of 0.1 to 2.0 Pa; And
(2) forming a nanofiber layer having nanofibers having an average diameter of 10 to 60 nm in a non-woven form on a porous substrate layer prepared according to the step (1); including a multilayer filter member according to claim 1 Method of manufacturing. The method according to claim 14,
The step (2) is a step of spinning a polymer solution; And spraying compressed air in the radial direction and the vertical direction to form the polymer solution as a non-woven nanofiber layer. The method according to claim 14,
And forming an adhesive layer (1a) in at least a portion of the area between the porous base layer and the nanofiber layer. The method according to claim 16,
The porous substrate layer, the adhesive layer and the nano-fiber layer is characterized in that it further comprises the step of heat-pressing the laminate (2a) is provided, the method of manufacturing a multi-layer filter member. The method according to claim 16,
The step (1a) may include forming an adhesive layer on at least a portion of one surface of the porous substrate layer, and forming the nanofiber layer on one surface of the porous substrate layer provided with the adhesive layer; Or forming an adhesive layer on at least a portion of one surface of the formed nanofiber layer, and laminating it to the porous substrate; characterized in that, the method of manufacturing a multi-layer filter member. The method according to claim 17,
The temperature at the time of the heat-pressing in the step (2a) is 70 to 350 ° C., and the pressure is 50 to 100 Pa. The method according to claim 14,
And providing a protective sheet on the nanofiber layer. Nano-filter comprising a multi-layer filter member according to any one of claims 1 to 13. A mask comprising a multilayer filter member according to any one of claims 1 to 13.

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