Mask

Abstract

This invention provides a breathable face mask that prevents the penetration of blood or droplets. The mask has an inner surface facing the wearer and an outer surface opposite the inner surface, and includes first to fourth filters. The first filter is disposed on the outer surface of the mask and is breathable, with a water absorption capacity of 100% or more and less than 1000%. The second filter is layered relative to the first filter on the inner surface of the mask and is breathable, with a water absorption capacity of less than 30%. The third filter is layered relative to the second filter on the inner surface of the mask and is breathable, and is composed of an electret filter with a water absorption capacity of less than 50%. The fourth filter is disposed on the inner surface of the mask and is breathable.

Description

[0001] This application is a divisional application based on the invention entitled "Mask" filed on October 13, 2017, with application number 201780063817.5 and application date of October 13, 2017, by NBC Mesh Technology Co., Ltd. Technical Field

[0002] This invention relates to a face mask that prevents the penetration of blood or droplets. Background Technology

[0003] Since 2010, Japan has experienced numerous natural disasters, including the Great East Japan Earthquake, the torrential rains in northern Kyushu, and the Kumamoto earthquake, forcing many evacuees to live in shelters. In addition to natural disasters, there have been overseas bombings, terrorist attacks, and building fires resulting in many casualties. Under these circumstances, the most problematic issue is infection control measures for rescue personnel. Many viral infections spread through blood, therefore, wearing protective clothing, masks, and caps is recommended during rescue operations. However, when putting on and taking off these protective suits, sometimes the blood of infected individuals can get on one's hands, or droplets can penetrate the protective clothing or mask, leading to infection through the mouth or other means.

[0004] To address these issues, virus-inactivating masks with antiviral agents fixed on the surface of the mask (Patent Document 1) and surgical masks that prevent droplet penetration have been developed (Patent Document 2), among others.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: WO2011 / 040035 Publication No.

[0008] Patent Document 2: Japanese Patent Publication No. 2014-503288. Summary of the Invention

[0009] However, while the mask in Patent Document 1 can inactivate attached viruses, it cannot prevent the penetration of substances containing large amounts of water, such as blood. Furthermore, while the mask in Patent Document 2 is excellent in preventing blood penetration (hereinafter referred to as "blood barrier property"), it is correspondingly difficult to breathe due to the use of a fine-mesh filter, and it also cannot inactivate attached viruses or bacteria.

[0010] Therefore, in order to solve the above problems, the object of the present invention is to provide a mask that is easy to breathe and can prevent the penetration of blood or droplets.

[0011] That is, the first invention is a face mask having an inner surface facing the wearer and an outer surface located on the opposite side of the inner surface, characterized in that it comprises:

[0012] The first filter is disposed on the outer surface and has air permeability, with a water absorption capacity of more than 100% and less than 1000%.

[0013] The second filter is stacked on the inner surface side relative to the first filter and is breathable, with a water absorption capacity of less than 30%.

[0014] A third filter, stacked relative to the second filter on the inner surface side and having air permeability, is composed of an electret filter with a water absorption capacity of less than 50%; and

[0015] A fourth filter is disposed on the inner surface and is breathable.

[0016] Furthermore, the second invention's mask is characterized in that, in the first invention, the weight per unit area of ​​the first filter is 15g / m². 2 Above and 40g / m 2 the following.

[0017] Furthermore, the third invention is characterized in that, in the first or second invention, the first filter and the second filter are filters other than electret filters.

[0018] Furthermore, the fourth invention is characterized in that, in any one of the first to third inventions, the fourth filter has a water absorption capacity of more than 100% and less than 1000%.

[0019] Furthermore, the fifth invention is characterized in that, in the fourth invention, inorganic microparticles with bactericidal and / or antiviral properties are fixed on at least a portion of the first filter and / or the fourth filter.

[0020] Furthermore, the sixth invention is characterized in that, in any one of the first to fifth inventions, the first filter and the fourth filter are made of rayon fibers, and the second filter and the third filter are made of polypropylene fibers.

[0021] According to the present invention, a mask that is easy to breathe and can prevent the penetration of blood or droplets is provided. Furthermore, according to the fifth invention described above, a mask capable of inactivating bacteria or viruses contained in attached blood or droplets is provided. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described. In this specification, "water absorption capacity" refers to a value measured according to JIS L 1912:1997. Specifically, the water absorption capacity WA [%) is calculated according to the following formula (1).

[0023] [Chemical Formula 1]

[0024]

[0025] In equation (1) above, M K It is the weight of the sample before immersion in water (the average of 5 measurements), M N It is the weight of the sample after immersion in water (the average of 5 measurements).

[0026] This embodiment is a mask consisting of four breathable filters, stacked in the order of first filter, second filter, third filter, and fourth filter from the outermost layer (the layer furthest from the wearer) towards the inside. These filters are welded together along the thickness direction of the mask to form a single unit. This integration process is not limited to welding; other methods, such as sewing, can also be used.

[0027] First, the first filter constituting the mask of the present invention will be described.

[0028] The first filter is characterized by a water absorption capacity of 100% or more and less than 1000%, i.e., it is made of a hydrophilic material. The water absorption capacity of the first filter is preferably 100% or more and less than 900%, more preferably 100% or more and less than 850%. Blood or droplets adhere most to the first filter, which is the outermost layer. Since the first filter is hydrophilic, blood or droplets colliding with it do not move towards the second filter but easily spread along the surface of the first filter. Therefore, the amount of blood or droplets penetrating the first filter can be significantly reduced.

[0029] As for the material used in the first filter, any material with hydrophilic properties that easily wet and spread can be appropriately selected by those skilled in the art, and natural fibers, regenerated fibers, semi-synthetic fibers, etc. are preferred. Examples of such fibers include cotton, kapok, hemp, wool, silk, Lyocell, Tencel, rayon, rayon-PET (polyethylene terephthalate) blended fibers, viscose rayon, high-strength viscose fiber (polynosic), cuprammonium fiber (cupra), casein fibers, regenerated silk, cellulose acetate, triacetate, oxidized acetate, promix, etc. Considering moderate strength and good hand feel, cotton, rayon, rayon-PET blended fibers, etc. are particularly preferred.

[0030] In addition, the first filter is breathable, but to provide functions beyond breathability, non-woven fabric is preferred as the material for the first filter. Using non-woven fabric ensures a particularly good skin feel and low skin irritation. Alternatively, the hydrophilic material of the first filter may exist in three dimensions (along the two-dimensional direction along the surface of the first filter and the thickness direction of the first filter), thereby improving water absorption. Furthermore, the weight per unit area of ​​the first filter is preferably 15 g / m². 2 Above and 40g / m 2 The following is more preferably 15g / m 2 Above and 25 / m 2 The following applies if the weight per unit area is less than 15g / m². 2 If the blood or droplets easily pass through the first filter, it becomes difficult for them to spread along the surface of the first filter as described above. On the other hand, if the weight per unit area is greater than 40 g / m²... 2 If the mask is not properly sealed, the wearer will experience difficulty breathing. Furthermore, when inhaling, in addition to the air flowing in from the outside of the mask (air flowing in through the first to fourth filters), more air flows in from the gap between the mask and the wearer (face). This results in an increase in the amount of air inhaled without passing through the mask, reducing the effectiveness of wearing the mask, which is therefore not preferable.

[0031] Furthermore, inorganic microparticles with antibacterial / antiviral properties (hereinafter referred to as antibacterial / antiviral microparticles) are bonded to the outer surface of the first filter (at least one of the outer side of the mask and the side opposite to the second filter) by an adhesive.

[0032] The antibacterial / antiviral microparticles are microparticles of at least one inorganic compound selected from the group consisting of platinum (II) iodide, palladium (II) iodide, silver (I) iodide, copper (I) iodide, and copper thiocyanate (I). They exhibit antibacterial activity regardless of whether they are Gram-positive or Gram-negative, and can inactivate viruses regardless of the presence or absence of an envelope. Furthermore, the antibacterial / antiviral microparticles used in this invention can inactivate bacteria or viruses even in the presence of proteins or lipids.

[0033] The viral inactivation mechanism of antibacterial / antiviral particles is not yet clear. However, it is believed that when antibacterial / antiviral particles come into contact with moisture in the air or droplets, they affect the electrical charges, membrane proteins, and DNA (deoxyribonucleic acid) on the surface of viruses attached to the mask of this embodiment through a partial redox reaction, thereby inactivating them. Therefore, if antibacterial / antiviral particles are present on a hydrophilic substrate (the outer surface of the filter), moisture in the air or droplets is easily retained on the hydrophilic substrate, thus making it easier for the antibacterial / antiviral particles to act on bacteria or viruses, which is preferable.

[0034] Here, the particle size of the antibacterial / antiviral microparticles is not particularly limited, and those skilled in the art can set it appropriately, but it is preferred that the average particle size is 1 nm or more and less than 500 nm. If the average particle size is less than 1 nm, it becomes materially unstable, and therefore the antibacterial / antiviral microparticles agglomerate due to physical interactions, making it difficult to uniformly fix the antibacterial / antiviral microparticles on the outer surface of the first filter. In addition, when the average particle size is 500 nm or more, the adhesion between the antibacterial / antiviral microparticles and the first filter is reduced compared to when it is less than 500 nm. It should be noted that in this specification, the average particle size refers to the volume average particle size.

[0035] In this embodiment, antibacterial / antiviral microparticles are fixed to the first filter using an adhesive. The adhesive is not particularly limited; a low molecular weight silane monomer or oligomer thereof is preferred because it reduces the barrier to contact between the antibacterial / antiviral microparticles and bacteria or viruses, effectively inactivating them. Furthermore, the adhesion between the silane monomer or oligomer thereof and the antibacterial / antiviral microparticles or the first filter is also high, thus enabling stable fixation of the antibacterial / antiviral microparticles to the first filter.

[0036] Thus, in the mask of this embodiment, if silane monomers or oligomers thereof are used as an adhesive, even a small amount of silane monomers or oligomers thereof has sufficient fixing force, thereby increasing the exposed area (area of ​​the area not covered by the adhesive) of the antibacterial / antiviral particles fixed on the first filter. Therefore, compared to using adhesives such as synthetic resins other than silane monomers or oligomers thereof to fix the antibacterial / antiviral particles to the first filter, the probability of bacteria or viruses attached to the surface of the first filter coming into contact with the antibacterial / antiviral particles can be increased. Therefore, even if the amount of antibacterial / antiviral particles is small, bacteria or viruses can be effectively inactivated.

[0037] Among the aforementioned silane monomers, silane coupling agents having unsaturated bond groups are preferred. This is because, since the coupling agent acquires multiple hydrophilic groups (-OH groups) through hydrolysis, it maintains high hydrophilicity (maintains water absorption capacity) even when hydrophobic antibacterial / antiviral microparticles composed of inorganic microparticles are immobilized on a highly hydrophilic first filter.

[0038] Furthermore, the antibacterial / antiviral microparticles are firmly fixed to the first filter through chemical bonds with silane monomers or their oligomers. Therefore, compared to conventional methods using adhesives such as synthetic resins other than silane monomers or their oligomers, the detachment of the antibacterial / antiviral microparticles from the first filter is significantly suppressed. Thus, the mask of this embodiment can prolong the time it can maintain the inactivation of bacteria or viruses compared to conventional masks. Additionally, by selecting a silane monomer, the antibacterial / antiviral microparticles can be retained on the first filter through condensation reactions, amide bonds, hydrogen bonds, ionic bonds, van der Waals forces, or physical adsorption.

[0039] In this embodiment, there is no particular limitation on the manner in which the antibacterial / antiviral particles are maintained on the first filter, and those skilled in the art can choose an appropriate method. For example, the antibacterial / antiviral particles can be dispersed on the first filter. Alternatively, the aggregate of antibacterial / antiviral particles can be maintained on the first filter in a planar or three-dimensional manner. More specifically, the aggregate can be maintained in a dotted, island-like, or film-like manner. Furthermore, when the aggregate is maintained in a three-dimensional manner, the antibacterial / antiviral particles contain particles that are bound to the first filter via silane monomers or oligomers thereof (referred to as antibacterial / antiviral particle a), and particles bound to antibacterial / antiviral particle a via silane monomers or oligomers thereof.

[0040] Regarding the amount of antibacterial / antiviral microparticles retained on the mask of this embodiment, those skilled in the art can appropriately set it considering the purpose or use of the mask and the particle size of the antibacterial / antiviral microparticles. Specifically, relative to the total amount of substances (adhesive and antibacterial / antiviral microparticles) retained on the first filter, the antibacterial / antiviral microparticles are preferably 1.0% to 80.0% by mass, more preferably 5.0% to 60.0% by mass. When the antibacterial / antiviral microparticles are less than 1.0% by mass, the activity of inactivating bacteria or viruses is reduced compared to the case where it is 1.0% by mass or more. In addition, even if the antibacterial / antiviral microparticles are more than 80.0% by mass, the effect of inactivating bacteria and viruses is not significantly different compared to the case where it is in the range of 1.0% to 80.0% by mass. Furthermore, if the antibacterial / antiviral microparticles are more than 80.0% by mass, due to insufficient amount of adhesive, the adhesiveness of the oligomer formed by the condensation reaction of silane monomers is reduced, and the antibacterial / antiviral microparticles are more likely to detach from the first filter compared to the case where it is less than 80.0% by mass.

[0041] The mask according to this embodiment can inactivate various viruses regardless of the type of genome or the presence or absence of an envelope. Examples of viruses that could be identified as such include: rhinovirus, poliovirus, foot-and-mouth disease virus, rotavirus, norovirus, enterovirus, hepatoviruses, astroviruses, sap virus, hepatitis E virus, influenza A, B, and C viruses, parainfluenza viruses, mumps virus, measles virus, human metapneumoviruses, RS virus (respiratory syncytial virus), Nipah viruses, Hendra viruses, yellow fever virus, dengue viruses, Japanese encephalitis virus, West Nile virus, hepatitis B and C viruses, eastern and western equine encephalitis virus, O'nyong-nyong viruses, rubella virus, Lassa viruses, Junin viruses, and Machupo virus. Viruses, including Guanaritoviruses, Sabia viruses, Crimean-Congohemorrhagic fever viruses, sandfly fever, Hantaviruses, Sin Nombre viruses, rabies virus, Ebola virus, Marburg viruses, bat rabies virus, human T-cell leukemia virus, human immunodeficiency virus, human coronaviruses, SARS coronaviruses, human parvoviruses, polyomaviruses, and human papillomavirus. The viruses include papillomaviruses, adenoviruses, herpesviruses, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, smallpox virus, monkeypox virus, cowpox virus, molluscum contagiosum virus, parapoxviruses, and Zika virus.

[0042] Furthermore, the mask according to this embodiment is not particularly limited to bacteria that can be inactivated; it can kill various bacteria regardless of their Gram-positive, Gram-negative, aerobic, or anaerobic nature. Examples of such bacteria include: *Escherichia coli*, *Staphylococcus aureus*, *Staphylococcus epidermidis*, *Streptococcus*, *Streptococcus pneumoniae*, *Haemophilus influenzae*, *Bordetella pertussis*, *Enterobacterium*, *Klebsiella pneumoniae*, *Pseudomonas aeruginosa*, *Vibrio*, *Salmonella dysenteriae*, *Vibrio cholerae*, *Symptomyces dysenteriae*, *Bacillus anthracis*, *Mycobacterium tuberculosis*, *Botoxobacterium botulism*, *Clotrimazole*, and *Streptococcus*.

[0043] Furthermore, according to this embodiment, even if droplets adhere to the mask, it can inactivate bacteria or viruses, even if lipids or proteins are present, in addition to bacteria or viruses.

[0044] Therefore, the mask according to this embodiment can inactivate bacteria or viruses attached to it, thus preventing infection of the wearer. Furthermore, even in the event of contact with a used mask, secondary infection is unlikely.

[0045] Next, the second filter of this embodiment will be described.

[0046] The second filter in this embodiment is characterized by a water absorption capacity of less than 30%. Preferably, the water absorption capacity of the second filter is less than 20%, more preferably less than 10%. Because the water absorption capacity of the second filter is less than 30%, it not only blocks droplets or blood that have permeated the first filter, but also assists the blood or droplets in moving along the first filter. If the water absorption capacity is 30% or more, droplets or blood will permeate the second filter, which is undesirable.

[0047] The second filter is preferably a filter other than an electret filter. While electret filters have high dust collection efficiency and can capture fine particles, if a high-efficiency filter is placed near the outer layer of a multi-layered filter mask, such as the second filter in this application, it is prone to clogging due to dust and other contaminants in a short time, leading to a decrease in the mask's functionality. Therefore, it is preferable to place a filter with good dust collection efficiency in the filter located closer to the outermost filter than the outermost filter. As described later, in the mask of this embodiment, since an electret filter is used in the third filter, particles that have permeated the second filter can be captured through the third filter. Therefore, by using a filter other than an electret filter in the second filter, a mask that is less prone to clogging and has high dust collection efficiency can be obtained. Furthermore, when the second filter is composed of a filter other than an electret filter, the first filter is also preferably composed of a filter other than an electret filter. Since both the first and second filters are composed of filters other than electret filters, clogging is even less likely. Furthermore, since filters located on the outer or inner surfaces of a mask are easily exposed to dust, dust and other particles can quickly cause blockages when these filters are made of electret filters, leading to a decline in the mask's functionality. Therefore, the first and fourth filters are preferably made of filters other than electret filters. Additionally, since electret filters are charged, they are made of hydrophobic materials that easily generate electricity (i.e., it is difficult to make them of hydrophilic materials that are difficult to charge). Therefore, filters using hydrophilic materials (e.g., the first filter) are difficult to configure as electret filters.

[0048] For materials with a water absorption capacity of less than 30%, synthetic fibers are preferred. Examples of synthetic fiber materials include polyester, polypropylene, polyethylene terephthalate, nylon, acrylic acid, polyacrylic acid, and polymethyl methacrylate; however, polypropylene, with its excellent properties of preventing the penetration of blood and the like, is preferred.

[0049] The second filter in this embodiment also has the same air permeability as the first filter described above. However, in order to give it functions other than air permeability, non-woven fabric is preferred as the material for the second filter. By using non-woven fabric, a good skin feel and low skin irritation can be ensured. Furthermore, the water-absorbing material of the second filter, as described above, exists in three dimensions (along the two-dimensional direction along the surface of the first filter and the thickness direction of the first filter), which improves its hydrophobicity. In addition, the weight per unit area of ​​the second filter is preferably 15 g / m². 2 Above and 40g / m 2 The following is more preferably 15g / m 2 Above and 25 / m 2The following applies if the weight per unit area is less than 15g / m². 2 If blood or droplets easily pass through the second filter, it will be difficult for the second filter to perform its functions. On the other hand, if the weight per unit area is greater than 40g / m2, the wearer of the mask will experience difficulty breathing.

[0050] Furthermore, the third filter of this embodiment will be described.

[0051] The third filter in this embodiment is characterized by being composed of an electret filter with a water absorption capacity of less than 50%. Preferably, the water absorption capacity of the third filter is less than 40%, more preferably less than 30%.

[0052] Electret filters are known for their high dust collection efficiency, effectively capturing viruses, bacteria, and dust that have permeated the first and second filters, even with low weight per unit area. In cases where the third filter is not an electret filter, fine dust particles may sometimes permeate. Furthermore, by constructing this electret filter from the same low-absorption material as the second filter, droplets or blood that have permeated the second filter can be effectively blocked.

[0053] For materials with a water absorption capacity of less than 50%, synthetic fibers are preferred. Specific examples of synthetic fiber materials include polyester, polypropylene, polyethylene terephthalate, nylon, acrylic acid, polyacrylic acid, and polymethyl methacrylate, but polypropylene, which has excellent properties in preventing blood and other permeability, is preferred.

[0054] The third filter in this embodiment also possesses air permeability, similar to the first and second filters described above. However, to provide functions beyond air permeability, a non-woven fabric is preferred as the material for the third filter. Using a non-woven fabric ensures a pleasant skin feel and low skin irritation. The water-absorbing material of the third filter exists in three dimensions (along the two-dimensional direction along the surface of the first filter and the thickness direction of the first filter), thereby improving hydrophobicity. Furthermore, the weight per unit area of ​​the third filter is preferably 15 g / m². 2 Above and 40g / m 2 The following is more preferably 15g / m 2 Above and 25 / m 2 The following applies if the weight per unit area is less than 15g / m². 2 If blood or droplets easily pass through the third filter, it will be difficult for the third filter to perform its functions. On the other hand, if the weight per unit area is greater than 40g / m²... 2 If the mask is worn too long, the wearer will experience difficulty breathing.

[0055] Finally, the fourth filter of this embodiment will be described.

[0056] The fourth filter in this embodiment is characterized by its breathability. Since it is sometimes impossible to completely prevent the penetration of blood or droplets using the first to third filters, blood barrier properties are reduced without a fourth filter. The fourth filter only needs to be breathable and is not particularly limited, but since the fourth filter comes into direct contact with the wearer, if its absorbency is low, moisture from exhaled breath will remain on the inside of the mask, causing discomfort. Therefore, a hydrophilic filter is preferred. For example, the absorbency of the fourth filter can be 100% or more and less than 1000%. Here, the absorbency of the fourth filter is preferably 100% or more and less than 900%, more preferably 100% or more and less than 850%. Therefore, the material of the fourth filter, like that of the first filter, is preferably natural fibers, regenerated fibers, semi-synthetic fibers, etc., and cotton and rayon are particularly preferred.

[0057] Furthermore, similarly to the first filter, antibacterial / antiviral microparticles can be fixed to the outer surface of the fourth filter (at least one of the surface exposed to the wearer and the surface opposite the third filter). By fixing the antibacterial / antiviral microparticles to the outer surface of the fourth filter, bacteria or viruses contained in droplets or blood that have passed through the third filter can be inactivated. Moreover, even with prolonged use of the mask, odors caused by bacterial growth can be suppressed, thus providing a safer and more durable mask.

[0058] The average particle size or mass percentage of the antibacterial / antiviral microparticles can be set in the same way as the antibacterial / antiviral microparticles fixed on the first filter. Additionally, silane monomers or oligomers thereof can be used as a binder.

[0059] In this embodiment of the mask, it is preferable that not only is the water absorption capacity of the first filter set to 100% or more and less than 1000%, but the water absorption capacity of the fourth filter is also set to 100% or more and less than 1000%, and antibacterial / antiviral microparticles are fixed (retained) on at least a portion of these first and / or fourth filters. In this mask of the present embodiment, since the first and fourth filters easily retain moisture, the antibacterial / antiviral microparticles retained on the filters easily come into contact with moisture, thus easily improving antibacterial and antiviral properties. Furthermore, the first and fourth filters are filters disposed on the outer or inner surface of the mask, in locations where bacteria or viruses easily attach. Therefore, it is easier to inactivate more bacteria or viruses attached to the mask.

[0060] In addition, in the mask of this embodiment, it is preferred that the first filter and the fourth filter are made of rayon fibers, and the second filter and the third filter are made of polypropylene fibers.

[0061] The mask of this embodiment has been described in detail above, but the present invention is not limited thereto and may be implemented in other ways. Thus, when using the mask of the present invention, the wearer can be comfortable and it can prevent the penetration of blood or droplets, as well as prevent infection by attached bacteria or viruses.

[0062] Example

[0063] The present invention will now be described in more detail with reference to specific embodiments. However, the present invention is not limited to these embodiments.

[0064] (Example 1)

[0065] The first filter uses a rayon-PET blended nonwoven fabric (20g / m²). 2 Polypropylene nonwoven fabric (20g / m²) is used as the second filter. 2 As the third filter, a polypropylene electret filter 1 (Mitsui Chemicals Co., Ltd. MER04, 20 g / m²) was used. 2 The fourth filter uses the same rayon-PET blended nonwoven fabric (20g / m²) as the first filter. 2 These four filters were welded together in the order of first, second, third, and fourth filters, and this was used as a sample of Example 1.

[0066] (Example 2)

[0067] In addition to making the first and fourth filters of Example 1 into rayon nonwoven fabric (20g / m² per unit area weight), 2 In addition to the above, the sample of Example 2 was obtained by the same method as in Example 1.

[0068] (Example 3)

[0069] 1.0% by mass of commercially available copper iodide (I) powder was added to ethanol as an antibacterial / antiviral agent, followed by 1.4% by mass of zirconium oxide particles covalently bonded to the surface with methacryloxypropyltrimethoxysilane. The mixture was pre-dispersed in a homogenizer for 5 minutes, then pulverized and dispersed using a bead mill to obtain a slurry with an average particle size of 146 nm. Here, average particle size refers to volume average particle size. Next, 0.7% by mass of tetramethoxysilane was added to the slurry, and it was sprayed onto a rayon nonwoven fabric identical to the first filter in Example 2. The slurry was then dried at 120°C for 3 minutes to obtain the first filter with antibacterial / antiviral properties used in Example 3. The material formed by fusing this first filter with antibacterial / antiviral properties, along with the second, third, and fourth filters used in Example 2, was used as a sample for Example 3.

[0070] (Example 4)

[0071] Except that the same filter as the first filter in Example 3 was used as the fourth filter, the sample of Example 4 was obtained using the same method as in Example 3.

[0072] (Example 5)

[0073] Except for the rayon nonwoven fabric used in the first filter of Example 4, which has a unit area weight of 15 g / m², 2 In addition, the sample of Example 5 was obtained using the same method as in Example 4.

[0074] (Example 6)

[0075] Except for the rayon nonwoven fabric used in the first filter of Example 4, which has a unit area weight of 40 g / m², 2 In addition, the sample of Example 6 was obtained using the same method as in Example 4.

[0076] (Example 7)

[0077] In addition to using the second filter of Example 4 as polyethylene terephthalate (PET) nonwoven fabric (20 g / m²), 2 In addition to the above, the sample of Example 7 was obtained using the same method as in Example 4.

[0078] (Example 8)

[0079] In addition to using the third filter of Example 4 as a PP (polypropylene) electret filter 2 (Toray Industries, Inc. EMO2010, unit area weight 20g / m²), 2 In addition to the above, the sample of Example 8 was obtained using the same method as in Example 4.

[0080] (Example 9)

[0081] In addition to using cotton nonwoven fabric (20g / m² per unit area weight) 2 Except for the rayon nonwoven fabric used in the fourth filter of Example 4, the sample of Example 9 was obtained using the same method as in Example 4.

[0082] (Comparative Example 1)

[0083] The first, third, and fourth filters of Example 2 were fused together to obtain the sample of Comparative Example 1.

[0084] (Comparative Example 2)

[0085] The first, second, and fourth filters of Example 2 were fused together to obtain the sample of Comparative Example 2.

[0086] (Comparative Example 3)

[0087] In addition to using the same polypropylene nonwoven fabric (20 g / m²) as the second filter in Example 2, 2 In addition to the first filter, the sample of Comparative Example 3 was obtained using the same method as in Example 2.

[0088] (Comparative Example 4)

[0089] In addition to using the same rayon nonwoven fabric (20g / m²) as the first filter in Example 2, 2 In addition to the second filter, the sample of Comparative Example 4 was obtained using the same method as in Example 2.

[0090] (Comparative Example 5)

[0091] In addition to using the same rayon nonwoven fabric (20g / m²) as the first filter in Example 2, 2 In addition to the third filter, the sample of Comparative Example 5 was obtained using the same method as in Example 2.

[0092] (Comparative Example 6)

[0093] The first, second, and third filters of Example 2 were fused together to obtain the sample of Comparative Example 6.

[0094] The combinations of the above samples are shown in Table 1.

[0095] [Table 1]

[0096]

[0097] (Water absorption test)

[0098] Regarding the water absorption capacity of each of the above samples (Examples 1 to 9, Comparative Examples 1 to 6), a water absorption test of JIS L 1912:1997 "Test Methods for Medical Nonwoven Fabrics" was carried out: the test was carried out based on the water absorption amount, and the water absorption capacity (%) was calculated. The results are shown in Table 2.

[0099] (Blood barrier property test)

[0100] Regarding the blood barrier property test of each of the above samples (Examples 1 to 9, Comparative Examples 1 to 6), it was carried out based on ASTM F1862 "Standard Test Method for Resistance of Medical Face Masks to Penetration by Synthetic Blood". Thirty-two samples of each were prepared. Among the 32 samples, when there was no blood penetration in 29 or more samples, it was considered qualified. At this time, the injection pressure of the artificial blood was 160 mmHg. The results are shown in Table 2.

[0101] (Antiviral property evaluation)

[0102] 0.4 g was collected from the first filter and the fourth filter of Examples 2 to 9 and the first filter of Comparative Example 1 respectively. Each sample (0.4 g) was placed in a vial, 0.2 ml of virus solution was dropped in, and it was allowed to act at 37°C for 5 minutes. After acting for 5 minutes, 10 ml of SCDLP medium (soybean casein glucose lecithin Tween 80 medium) was added, and the virus was washed by stirring using a Vortex mixer. Then, it was diluted (serial 10-fold dilution) with MEM (minimum Eagle’s medium) diluent until each reaction sample reached 10-2 to 10-5. 100 μL of the sample solution was inoculated into MDCK (Madin-Darby Canine Kidney) cells cultured in a petri dish. After standing for 90 minutes to allow the virus to adsorb to the cells, 0.7% agar medium was overlaid, and it was cultured in an incubator at 34°C and 5% CO2 for 48 hours, then fixed with formalin, subjected to methylene blue staining, the number of plaques formed was counted, and the infectious titer of the virus (PFU: plaque-forming units) was calculated. Here, for the first filter and the fourth filter in each sample, the infectious titer of the virus was calculated respectively. The results are shown in Table 2.

[0103] [Table 2]

[0104]

[0105] In all embodiments of the present invention, the blood barrier performance was satisfactory. However, in Comparative Examples 1, 2, and 6 (lacking a second, third, or fourth filter), Comparative Example 3 (low absorbency of the first filter), Comparative Example 4 (high absorbency of the second filter), and Comparative Example 5 (high absorbency of the third filter), the blood barrier performance was unsatisfactory. That is, if a nonwoven fabric substrate with high absorbency (over 100%) is used in the first filter, and hydrophobic nonwoven fabric substrates with low absorbency are used in the second and third filters (second filter: absorbency less than 30%, third filter: absorbency less than 50%), and a fourth filter is not provided, a decrease in blood barrier performance is observed. Furthermore, in the samples of Examples 3-9, which underwent antiviral processing, even within a short time of 5 minutes, a high antiviral effect below the detection limit was confirmed. From the above results, it can be seen that the mask of this embodiment, due to its excellent blood barrier performance and high antiviral effect, can provide a blood-barrier mask that helps prevent secondary infection.

Claims

1. A face mask having an inner surface facing the wearer and an outer surface located on the opposite side of the inner surface, characterized in that, From the outside to the inside, the following are included: The first filter is disposed on the outer surface and has air permeability, with a water absorption capacity of more than 100% and less than 1000%. The second filter is stacked on the inner surface side relative to the first filter and is breathable, with a water absorption capacity of less than 30%. A third filter, stacked relative to the second filter on the inner surface side and having air permeability, is composed of an electret filter with a water absorption capacity of less than 50%; and A fourth filter, disposed on the inner surface, is breathable and has a water absorption capacity of over 100% and less than 1000%. The second filter and the third filter are both nonwoven fabrics made solely of synthetic fibers. The first filter is the outermost layer of the mask. The weight per unit area of ​​the second filter and the third filter is 15 g / m². 2 Above and 40g / m 2 the following, The first filter and the fourth filter are made of rayon fibers or cotton fibers.

2. The mask according to claim 1, characterized in that, The weight per unit area of ​​the first filter is 15 g / m². 2 Above and 40g / m 2 the following.

3. The mask according to claim 1 or 2, characterized in that, The first filter and the second filter are filters other than electret filters.

4. The mask according to claim 1 or 2, characterized in that, The first filter has a water absorption capacity of over 100% and below 900%. The fourth filter has a water absorption capacity of over 100% and below 900%.

5. The mask according to claim 4, characterized in that, Inorganic microparticles with bactericidal and / or antiviral properties are fixed on at least a portion of the first filter and / or the fourth filter.

6. The mask according to claim 1 or 2, characterized in that, The first filter and the fourth filter are made of rayon fibers, and the second filter and the third filter are made of polypropylene fibers.

Images