JP5986780B2 - Antiviral material - Google Patents

Description

  The present invention relates to nanofibers having antiviral properties that exert high effects on various viruses regardless of the presence or absence of an envelope.

  In recent years, deaths due to viral infections such as SARS (Severe Acute Respiratory Syndrome), Norovirus and avian influenza have been reported. In particular, in 2009, due to traffic development and virus mutations, we faced a “pandemic (infection explosion)” crisis that spreads virus infection all over the world, and there was also a major damage caused by viruses such as foot-and-mouth disease. Measures are needed. In order to cope with such a situation, development of antiviral agents using vaccines is urgently needed. However, in the case of vaccines, infection can be prevented only by specific viruses due to its specificity. Therefore, development of an antiviral agent capable of exerting an antiviral effect on various viruses is strongly desired.

  Here, as the fiber having antiviral properties, anti-viral rayon fibers prepared by extrusion molding by adding copper oxide particles to rayon viscose (Patent Document 1), against viruses in the fibers There are antiviral fibers in which metals and metal compounds having an inactivating effect are dispersed (Patent Document 2).

Special table 2010-522833 International Publication No. 2005/083171 Pamphlet

  However, in the method of adding and dispersing antiviral particles in the fiber as in Patent Document 1, it is necessary to make the antiviral particles fine, and it is difficult to design fine particles. In addition, when the particle size of the antiviral fine particles is reduced, the inorganic fine particles aggregate with each other, resulting in problems such as inefficiency, and the adhesion between the aggregate and the substrate is lowered and peeled off. Furthermore, there is a problem that the fiber diameter is limited by the particle diameter of the antiviral fine particles. Further, as in Patent Document 2, when metal fine particles having antiviral properties are precipitated in the fiber resin by a reduction method or the like, the particle size of the metal fine particles is small, but the amount of precipitation is limited, and the antiviral properties are limited. If the amount of precipitation is increased to improve the fiber properties, problems such as poor fiber properties occur.

  An object of the present invention is to provide an antiviral nanofiber that can be freely controlled to have a fiber diameter and a fiber length according to the purpose of use, and that the nanofiber itself has antiviral properties. In the present specification, virus inactivation and antiviral properties refer to the same action.

  1st invention is antiviral material which consists of nanofiber comprised by copper and the oxide of copper, Comprising: Monovalent copper oxide exists in the surface part of the said nanofiber at least, Antiviral material characterized by the above-mentioned It is.

  According to a second invention, in the first invention, the antiviral nanofiber has a diameter of 10 nm or more and 100 nm or less, a fiber length of 100 nm or more and 100 μm or less, and an aspect ratio of 10 or more. It is the nanofiber which has antiviral property characterized by these.

  According to a third aspect of the present invention, after copper is deposited in the pores of the porous body, the copper nanofibers obtained by removing the porous body are immersed in an aqueous solution containing a reducing agent. It is a method for producing nanofibers having antiviral properties, characterized in that at least a part of the surface is reduced to a monovalent copper compound having an antiviral effect.

  According to the present invention, it is possible to provide a nanofiber having an antiviral property that exhibits an antiviral property more effectively than a fine particle by using a fiber shape.

It is a schematic diagram of the fiber cross section of the nanofiber which has antiviral property of embodiment. It is a SEM photograph of the nanofiber which has antiviral property of an embodiment. It is the analysis result by the wide-angle X-ray-diffraction apparatus of the nanofiber which has antiviral property of embodiment.

  Hereinafter, embodiments of nanofibers having antiviral properties will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing a part of a cross section of the nanofiber 100 having antiviral properties according to the present embodiment. The nanofiber 100 having antiviral properties includes at least a monovalent copper compound 10 on the surface.

  Although the virus inactivation mechanism of the nanofiber 100 having antiviral properties is not necessarily clear at present, the monovalent copper compound 10 contained in the antiviral nanofiber 100 is not capable of reacting with moisture in the air or in droplets. When contacted, a part thereof is considered to cause a redox reaction or generate active species, thereby causing some damage to the virus and inactivating the virus.

  The virus that can inactivate the nanofiber 100 having antiviral properties according to the present embodiment is not particularly limited, and various viruses can be inactivated regardless of the type of genome, the presence or absence of an envelope, and the like. . For example, rhinovirus, poliovirus, rotavirus, foot-and-mouth disease virus, norovirus, enterovirus, hepatovirus, astrovirus, sapovirus, hepatitis E virus, A, B, C influenza virus, parainfluenza virus, mumps virus (mumps) ), Measles virus, human metapneumovirus, RS virus, Nipah virus, Hendra virus, yellow fever virus, dengue virus, Japanese encephalitis virus, West Nile virus, type B, hepatitis C virus, eastern and western equine encephalitis virus, Onyon Nyon virus, rubella virus, Lassa virus, Junin virus, Machupo virus, Guanarito virus, Sabia virus, Crimea congo hemorrhagic fever virus, snubber fever virus, Hantawi , Sinnombre virus, rabies virus, Ebola virus, Marburg virus, bat lyssa virus, human T cell leukemia virus, human immunodeficiency virus, human coronavirus, SARS coronavirus, human porvovirus, polyoma virus, human papillomavirus , Adenovirus, herpes virus, varicella-zoster virus, EB virus, cytomegalovirus, smallpox virus, monkeypox virus, cowpox virus, molasipox virus, parapox virus and the like.

  The fiber diameter of the nanofiber 100 having antiviral properties of the present embodiment is not particularly limited depending on the use environment, but is preferably 10 nm or more and 100 nm or less. This is because when the thickness is less than 10 nm, it is difficult to produce. When the thickness is larger than 100 nm, it is difficult to deposit copper on the mold, although a porous material as a template can be produced. The fiber length is preferably 100 nm or more and 100 μm or less. This is because if it is less than 100 nm, it is difficult to separate and recover from the mold, and if it is longer than 100 μm, it takes time to produce the mold, which is industrially unsuitable.

  In the present embodiment, the fiber diameter of the nanofiber 100 is an average value of fiber diameter (average fiber diameter), and the fiber length is an average value of fiber length (average fiber length). The average fiber diameter and the average fiber length are obtained by observing an image of the nanofiber 100 of the present embodiment with a microscope. Specifically, the nanofibers 100 are observed with an electron microscope or the like, the nanofibers 100 are randomly selected in the obtained image, and the fiber diameter or fiber length of each nanofiber 100 is measured by image processing software. It is obtained from the number average value of.

  Moreover, it is preferable that the aspect ratio of the nanofiber 100 is 10 or more. Here, the aspect ratio of the nanofiber 100 is a value represented by L / D, where L is the length of the fiber and D is a diameter in a cross section perpendicular to the fiber length direction.

  Among the above-described nanofibers 100 having antiviral properties, the antiviral nanofibers 100 having short fibers of about 100 nm to 500 nm have high antiviral properties by filling and kneading into a polymer material such as a resin. Molecular material can be obtained. Furthermore, from the property of being in the form of a fiber, it is possible to obtain a high-strength polymer material by filling the polymer, and the present invention can easily create a nano-form. Since the particles are aggregated when filled into the polymer and the problem that the particles cannot be filled well does not occur, the antiviral effect can be efficiently expressed by adding a small amount of the nanofiber 100 to the polymer material. Molecular materials can be provided. In addition, the nanofiber 100 having antiviral properties of long fibers of about 1 μm to 100 μm is fixed to a general nonwoven fabric, woven fabric, or fiber structure made of knitted fabric, or the nanofiber 100 itself is made into a nonwoven fabric form. Thus, a filter having antiviral properties can be obtained.

  Here, the nanofiber 100 having antiviral properties of the present embodiment is characterized in that it is a nanofiber in which at least monovalent copper oxide 10 is present on the surface. The central portion 20 of the nanofiber 100 is not particularly limited, but may be divalent copper oxide or metallic copper. In particular, when metallic copper is used for the central portion 20, it is excellent in spreadability as compared with the case where divalent copper oxide is used. is there.

  As described above, the nanofiber 100 having antiviral properties of the present embodiment is used by processing itself into a non-woven fabric form as a fiber or a paper form such as mixed paper. In addition to filters such as air purifiers, air conditioners, vehicle air conditioners, ventilation fans, vacuum cleaners, electric fans, non-woven products such as masks, caps, shoe covers, medical drapes, protective clothing, or paper It can be used as a product.

  Moreover, you may carry | support the nanofiber 100 which has antiviral property of this embodiment on another fiber using a binder. The fiber is not particularly limited as long as it has fiber-forming ability, such as polyester, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, nylon, acrylic, polyvinylidene fluoride, Polymer materials such as polyethylene tetrafluoride ethylene, polytetrafluoroethylene, polyvinyl alcohol, Kevlar (registered trademark), polyacrylic acid, polymethyl methacrylate, rayon, cupra, tencel (registered trademark), polynodic, acetate, triacetate Can be used.

  These fibers carrying nanofibers 100 can be used for clothing, bedding, bedding, masks, handkerchiefs, towels, carpets, curtains and other textiles, knitted products, air cleaners, air conditioners, ventilators, vacuum cleaners, electric fans. Used for various products such as filters for vehicle air conditioners, fishing nets such as ginger and stationary nets, filters for water treatment, filters for drinking water, filters for ballast water treatment, protective clothing, protection nets, insect nets, etc. be able to. Moreover, you may process into a nonwoven fabric form with the fiber which carry | supported the nanofiber 100. FIG.

  Moreover, the nanofiber 100 of this embodiment can be kneaded into resin etc. as mentioned above. The resin for kneading the nanofiber 100 is not particularly limited. For example, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, EVA resin, SBC resin, polymethylpentene resin, polyvinyl chloride resin, polychlorinated resin. Vinylidene resin, polymethyl acrylate resin, polyvinyl acetate resin, polyamide resin, polyimide resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyacetal resin, polyarylate resin, polysulfate resin and other thermoplastic resins, silicone resin, Styrene elastomer such as polystyrene elastomer, olefin elastomer such as polyethylene elastomer and polypropylene elastomer, polyurethane elastomer etc. Polyurethane-based elastomers, vinyl chloride elastomers include thermoplastic elastomers such as polyester elastomer, nylon-based elastomer.

  These resin materials include film-like agricultural materials such as house films and tunnel house films, stationery such as clear folders and label tapes, computer peripherals such as keyboards and mice, and furniture such as chairs and sofas. Building materials such as exterior wall materials, sashes, doors, blinds, ceiling boards, floor boards, windows, interior materials such as wallpaper, carpets and resin tiles, handrails, hanging leather and other facilities, houses such as baths, toilets and septic tanks It can be applied to equipment and interior materials for vehicles.

  Moreover, the nanofiber 100 of this embodiment can be mixed with a coating material. By using it in a paint mixture, an antiviral material can be present in the form of a fiber on the surface of the coating film, and can effectively act on the surface of the coating film to exhibit an antiviral effect. Although it does not specifically limit as a coating material, For example, it can be set as the coating material containing a coating-film formation agent and the solvent as needed. Specific examples include oil-based paints, alcoholic paints, cellulose paints, synthetic resin paints, water-based paints, and rubber-based paints.

  These paints can be applied to the surface of various forms of objects such as fiber structures, films and sheets, panels, and molded articles. Examples of the material of the object include polymers, resins, metals, metal compounds, and the like.

  The nanofiber 100 of the present embodiment described above is less flocculated and excellent in dispersibility than powdered virus inactivated particles, so that even when supported on a carrier such as fiber or resin, it is effective in a small amount. An antiviral effect can be imparted. Moreover, since it is fibrous, even if the nanofiber 100 is used alone, an excellent effect that it can be used after being processed into a fiber structure such as a nonwoven fabric is obtained.

Furthermore, the nanofiber 100 of the present embodiment has a remarkable effect that an extremely high virus inactivating effect is obtained as compared with the antiviral effect obtained by, for example, the same amount of Cu ₂ O powder.

  Then, the manufacturing method of the nanofiber 100 which has antiviral property of this embodiment is demonstrated more concretely.

  The method for producing the antiviral nanofiber 100 of the present embodiment is not particularly limited as long as a nanofiber having a monovalent copper oxide 10 formed on the surface can be formed, but as an example, the nanofiber 100 using a porous body as a template. A method of manufacturing the will be described. Specifically, first, metallic copper is deposited on the pores of a porous body made of an inorganic or organic material having pores as a template by a treatment with a reducing agent or an electrochemical treatment, and then a porous material that is a template. This is a method for producing the nanofiber 100 of the present embodiment by removing the material and forming the monovalent copper oxide 10 on the surface by reducing the obtained copper nanofiber with a reducing agent. Hereinafter, the manufacturing method of the nanofiber 100 using a porous body will be described in detail.

  In the case where the central portion 20 is composed of divalent copper oxide, metallic copper is treated with a reducing agent or electrochemically in the pores of a porous body made of an inorganic or organic substance having pores as a template. After removing the porous material as a template, the obtained copper nanofibers are oxidized with an oxidizing agent to make the entire nanofibers into divalent copper oxide, and then reduced with a reducing agent. A monovalent copper oxide layer may be formed on the surface.

  First, an anodic oxide film is suitably used as the porous body serving as a template. As a material capable of forming the anodized film, aluminum, titanium, and alloys thereof are used. Aluminum or an alloy of aluminum is preferable. When aluminum or an aluminum alloy is used, a structure having a nanoscale structure can be easily formed in a self-organized manner, and further, a fine and cylindrical shape that exceeds the exposure technology using light and electron beams. This is because a nanostructure can be realized.

  Aluminum (or an aluminum alloy, titanium, or titanium alloy) serving as a base is treated with an aqueous solution containing sulfuric acid, phosphoric acid, chromic acid, or hydrofluoric acid, carboxylic acid such as oxalic acid or maleic acid, or sulfophthalate. A porous oxide film having a cylinder structure is formed by anodizing in an aqueous solution containing a sulfonic acid such as acid, sulfomaleic acid, sulfosalicylic acid and a small amount of sulfuric acid. At this time, in order to obtain a porous film having pores showing better verticality, linearity, and independence, the porous film formed by anodizing was once removed by wet etching using chromic acid or the like. Later, anodization may be performed again, two-step anodization may be performed, or a stamper having protrusions may be pressed against the surface of the aluminum substrate to form highly ordered holes arranged in a desired pattern. These protrusions may be transferred to the surface of the aluminum substrate as depressions, thereby forming the anodic oxidation hole formation starting point.

  After forming the porous oxide film by the above method, copper is deposited in the pores of the porous oxide film by applying an AC or DC potential in an aqueous solution containing copper ions. Alternatively, a catalyst such as palladium or palladium colloid is previously adsorbed in the pores of aluminum or titanium on which the porous oxide film is formed, and then copper is added to the pores of the porous oxide film in an aqueous solution containing a reducing agent and copper ions. May be deposited.

  Copper nanofibers can be obtained by physically and chemically removing the porous oxide film. For example, as a method for removing the porous oxide film, the porous oxide film is immersed in an aqueous sodium hydroxide solution. Thus, a method of removing the porous oxide film is preferable. In addition, after separating this copper nanofiber as a copper nanofiber, a natural oxide film (bivalent copper oxide) is formed on the fiber surface.

  Next, a monovalent copper oxide 10 layer is formed on the surface of the obtained copper nanofibers. The monovalent copper oxide 10 layer can be formed by reducing the natural oxide film to form a monovalent copper oxide layer or by oxidizing copper nanofibers to divalent copper oxide. And a method of forming a monovalent copper oxide layer by reducing the surface of the nanofiber of the copper oxide.

  When the obtained copper nanofiber is oxidized to produce a divalent copper oxide nanofiber, for example, sodium chlorite, potassium chlorite, sodium chlorate, potassium chlorate, potassium persulfate, perchlorine Bivalent copper oxide nanofibers can be formed by immersing copper nanofibers in an aqueous solution containing an oxidizing agent such as potassium acid and sodium hydroxide and subjecting it to an oxidation treatment.

  The reduction treatment step of the natural oxide film or the divalent copper oxide is intended to form at least monovalent copper oxide on the surface of the antiviral nanofiber. The reducing agents used are sodium borohydride, sodium hypophosphite, hydrazine, divalent tin compounds, oxycarboxylic acids such as malic acid, tartaric acid, citric acid, succinic acid, ascorbic acid, and their salts. Etc. Further, reducing sugars such as allose, altrose, glucose, mannose, gulose, idose, galactose, talose, fructose, maltose and the like may be used. Moreover, as sugar alcohols, sorbitol etc. may be used, for example. Moreover, methanol, ethanol, n-propanol, isopropanol, etc. may be used as alcohols. The reduction treatment may be performed by immersing a copper nanofiber or a divalent copper oxide nanofiber with a natural oxide film formed on the surface thereof in an aqueous solution containing these reducing agents, and then washing and drying. Nanofiber 100 having antiviral properties is obtained.

  The above is an example of the manufacturing method of the nanofiber 100 of this embodiment. According to the manufacturing method of the nanofiber 100 of the present embodiment described above, the fiber diameter and the fiber length of the copper nanofiber deposited in the pores can be easily controlled by controlling the pore diameter and thickness of the porous body serving as a template. In addition, by reducing the natural oxide film on the surface of the obtained copper nanofibers, a monovalent copper compound having antiviral properties can be efficiently deposited on the surface portion of the nanofibers. Nanofibers that exhibit excellent antiviral properties can be stably and efficiently produced.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.
Example 1
(Preparation of nanofibers with antiviral properties)
An aluminum plate (JISH1050) was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 60 seconds, and then immersed in a 5% nitric acid aqueous solution to neutralize and remove the alkali. Next, in a 20 ° C electrolyte containing 1.5 mol / L sulfuric acid, a platinum electrode is used as the counter electrode, and anodization is carried out for 20 minutes at a current density of 1.5 A / dm ^2. An 8 μm porous anodic oxide film was formed.

  Next, an aluminum plate with a porous anodic oxide coating with a thickness of about 8 μm is immersed in an aqueous solution containing 40 g / L copper sulfate and 10 g / L boric acid, and a 10 V AC voltage using a platinum electrode as the counter electrode. Was applied for 10 minutes to precipitate copper in the pores of the anodized film.

  Thereafter, the copper nanofibers were separated from the anodized film by immersing the anodized film in which copper was deposited in a 1 mol / L sodium hydroxide aqueous solution heated to 40 ° C. for 2 minutes. A 0.1 mol / L sodium hydroxide aqueous solution and methanol were immersed in a 1: 1 solution by volume for 10 minutes, and then washed with suction filtration with methanol to obtain copper nanofibers.

After that, reduction treatment was performed for 10 minutes while applying ultrasonic waves in 20 ml of methanol as a reducing agent in 20 ml of copper nanofibers, and then the supernatant was removed by centrifugation, and the precipitate was dried by vacuum drying, and antiviral Nanofibers having the following characteristics were prepared. The fiber diameter of the nanofiber having antiviral properties was 13 nm, and the fiber length was 3 μm. A scanning electron microscope image of the obtained nanofibers having antivirus is shown in FIG. 2 (Example 2).
In Example 1, nanofibers having antiviral properties were produced in the same manner as in Example 1 except that the reduction treatment was performed for 60 minutes.
(Example 3)
In Example 1, nanofibers having antiviral properties were prepared in the same manner as in Example 1 except that the reduction treatment was performed with 0.05 mol / L citric acid aqueous solution.
Example 4
In Example 3, nanofibers having antiviral properties were prepared in the same manner as in Example 3 except that the reduction treatment was performed for 60 minutes.
(Example 5)
Nanofibers having antiviral properties were produced in the same manner as in Example 1 except that the reduction treatment was performed with a 0.1 mol / L glucose aqueous solution adjusted to pH 12 in Example 1.
(Example 6)
In Example 5, nanofibers having antiviral properties were prepared in the same manner as in Example 5 except that the reduction treatment was performed for 60 minutes.
(Example 7)
An aluminum plate (JISH1050) was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 60 seconds, and then immersed in a 5% nitric acid aqueous solution to neutralize and remove the alkali. Next, in a 20 ° C electrolyte containing 1.5 mol / L sulfuric acid, a platinum electrode is used as the counter electrode, and anodization is performed for 120 minutes at a current density of 1.5 A / dm ² , so that the thickness of the aluminum plate is approximately A 50 μm porous anodic oxide coating was formed.

  Next, an aluminum plate with a porous anodized film with a thickness of about 50 μm is immersed in an aqueous solution containing 40 g / L of copper sulfate and 10 g / L of boric acid, and a 10 V AC voltage using a platinum electrode as the counter electrode. Was applied for 90 minutes to precipitate copper in the pores of the anodized film.

Thereafter, the copper nanofibers were separated from the anodized film by immersing the anodized film in which copper was deposited in a 1 mol / L sodium hydroxide aqueous solution heated to 40 ° C. for 6 minutes. A 0.1 mol / L sodium hydroxide aqueous solution and methanol were immersed in a 1: 1 solution by volume for 10 minutes, and then washed with suction filtration with methanol to obtain copper nanofibers.
Then, after performing reduction treatment for 60 minutes while applying ultrasonic waves in 20 ml of methanol as the reducing agent in 20 ml of copper nanofibers, the supernatant was removed by centrifugation, and the precipitate was dried by vacuum drying, antiviral properties Nanofibers having the following characteristics were prepared. The nanofiber had a fiber diameter of 13 nm and a fiber length of 30 μm.
(Example 8)
An aluminum plate (JISH1050) was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 60 seconds, and then immersed in a 5% nitric acid aqueous solution to neutralize and remove the alkali. Next, in a 20 ° C electrolyte containing 1.5 mol / L sulfuric acid, a platinum electrode is used as the counter electrode, and anodization is carried out for 20 minutes at a current density of 1.5 A / dm ^2. An 8 μm porous anodic oxide film was formed.

  Next, an aluminum plate with a porous anodic oxide coating with a thickness of about 8 μm is immersed in an aqueous solution containing 40 g / L copper sulfate and 10 g / L boric acid, and a 10 V AC voltage using a platinum electrode as the counter electrode. Was applied for 1 minute to precipitate copper in the pores of the anodized film.

Thereafter, the copper nanofibers were separated from the anodized film by immersing the anodized film in which copper was deposited in a 1 mol / L sodium hydroxide aqueous solution heated to 40 ° C. for 1 minute. A 0.1 mol / L sodium hydroxide aqueous solution and methanol were immersed in a 1: 1 solution by volume for 10 minutes, and then washed with suction filtration with methanol to obtain copper nanofibers.
Then, after performing reduction treatment for 60 minutes while applying ultrasonic waves in 20 ml of methanol as the reducing agent in 20 ml of copper nanofibers, the supernatant was removed by centrifugation, and the precipitate was dried by vacuum drying, antiviral properties Nanofibers having the following characteristics were prepared. The nanofiber had a fiber diameter of about 13 nm and a fiber length of about 0.2 μm.
Example 9
An aluminum plate (JISH1050) was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 60 seconds, and then immersed in a 5% nitric acid aqueous solution to neutralize and remove the alkali. Next, in a 20 ° C electrolyte containing 3wt% oxalic acid, a platinum electrode is used as the counter electrode, and anodization is performed for 120 minutes at a current density of 1.5A / dm ² , resulting in a thickness of about 50μm on the aluminum plate surface. A porous anodic oxide coating was formed.

Next, it was immersed in a mixed solution at 30 ° C. containing 1 wt / vol% phosphoric acid and 4 wt / vol% amidosulfuric acid for 1 hour to obtain an anodized film having a pore diameter of 100 nm. Then, in order to re-form a barrier layer (alumina part) partially dissolved with phosphoric acid and amide sulfuric acid, a platinum electrode was used as a counter electrode in a 20 ° C electrolyte solution containing 1.5 mol / L sulfuric acid and 1.5 A Anodization was performed at a current density of / dm ² for 3 minutes.

  Next, an aluminum plate with a porous anodized film with a thickness of about 50 μm is immersed in an aqueous solution containing 40 g / L of copper sulfate and 10 g / L of boric acid, and a 10 V AC voltage using a platinum electrode as the counter electrode. Was applied for 90 minutes to precipitate copper in the pores of the anodized film.

Thereafter, the copper nanofibers were separated from the anodized film by immersing the anodized film in which copper was deposited in a 1 mol / L sodium hydroxide aqueous solution heated to 40 ° C. for 6 minutes. A 0.1 mol / L sodium hydroxide aqueous solution and methanol were immersed in a 1: 1 solution by volume for 10 minutes, and then washed with suction filtration with methanol to obtain copper nanofibers.
Then, after performing reduction treatment for 60 minutes while applying ultrasonic waves in 20 ml of methanol as the reducing agent in 20 ml of copper nanofibers, the supernatant was removed by centrifugation, and the precipitate was dried by vacuum drying, antiviral properties Nanofibers having the following characteristics were prepared. The nanofiber had a fiber diameter of 100 nm and a fiber length of 30 μm.
(Example 10)
An aluminum plate (JISH1050) was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 60 seconds, and then immersed in a 5% nitric acid aqueous solution to neutralize and remove the alkali. Next, a platinum electrode is used as the counter electrode in an electrolyte at 20 ° C containing 3wt% oxalic acid, and anodization is performed at a current density of 1.5A / dm ² for 20 minutes. A porous anodic oxide coating was formed.

  Next, it was immersed in a mixed solution at 30 ° C. containing 1 wt / vol% phosphoric acid and 4 wt / vol% amidosulfuric acid for 1 hour to obtain an anodized film having a pore diameter of 100 nm. Thereafter, anodization was performed for 3 minutes at a current density of 1.5 A / dm 2 using a platinum electrode as a counter electrode in an electrolyte at 20 ° C. containing 1.5 mol / L sulfuric acid.

  Next, an aluminum plate with a porous anodic oxide coating with a thickness of about 8 μm is immersed in an aqueous solution containing 40 g / L copper sulfate and 10 g / L boric acid, and a 10 V AC voltage using a platinum electrode as the counter electrode. Was applied for 3 minutes to precipitate copper in the pores of the anodized film.

Thereafter, the copper nanofibers were separated from the anodized film by immersing the anodized film in which copper was deposited in a 1 mol / L sodium hydroxide aqueous solution heated to 40 ° C. for 1 minute. A 0.1 mol / L sodium hydroxide aqueous solution and methanol were immersed in a 1: 1 solution by volume for 10 minutes, and then washed with suction filtration with methanol to obtain copper nanofibers.
Then, after performing reduction treatment for 60 minutes while applying ultrasonic waves in 20 ml of methanol as the reducing agent in 20 ml of copper nanofibers, the supernatant was removed by centrifugation, and the precipitate was dried by vacuum drying, antiviral properties Nanofibers having the following characteristics were prepared. The nanofiber had a fiber diameter of about 100 nm and a fiber length of about 1 μm.
(Comparative Example 1)
Cu ₂ O powder (manufactured by Wako Pure Chemical Industries, Ltd.) (particle diameter (d50): 2.6 μm) was used for comparison with nanofibers.
(Observation of nanofibers with antiviral properties by scanning electron microscope)
The nanofibers having antiviral properties of Example 1 were observed with a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation). The obtained SEM image is shown in FIG. From this result, it was confirmed that the nanofibers having antiviral properties obtained in Example 1 had a fiber diameter of about 13 nm and a fiber length of about 3 μm.
(Analysis of nanofibers with antiviral properties by wide-angle X-ray diffraction)
The nanofibers having antiviral properties obtained in Example 1 were analyzed for the materials of the whole nanofibers using a wide angle X-ray diffractometer (manufactured by PANalytical). The results are shown in FIG. From the diffraction pattern of FIG. 3, it was confirmed that Cu, Cu ₂ O, and CuO were present in the antiviral nanofiber obtained in Example 1.
(Analysis of antiviral nanofibers by X-ray photoelectron spectrometer)
As a result of analyzing the anti-viral nanofiber obtained in Example 1 for the substance (element) on the surface of the nanofiber using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI), the concentration ratio of oxygen and copper was 38.7: 61.3. From these results, it was confirmed that CuO and Cu ₂ O were present on the surface in a ratio of about 1: 2.
Since the X-ray photoelectron spectrometer is an analysis of several nano surfaces, it was confirmed that the nanofibers having antiviral properties contain Cu ₂ O at least in part of the surface. From the above results, it was confirmed that the nanofiber having antiviral properties contains metal Cu inside, and at least a part of the surface thereof containing Cu ₂ O.
(Antiviral evaluation method)
Measurement of the virus inactivation of the nanofibers having antiviral properties in Examples and Comparative Examples was performed using influenza virus (influenza A / Kitakyushu / 159/93 (H3N2)) as an envelope virus and norovirus as a non-enveloped virus. The feline calicivirus (feline calicivirus (F9 strain)), which is commonly used as an alternative to the above, was used. The target viruses used are influenza virus ((influenza A / Kitakyushu / 159/93 (H3N2)) cultured on MDCK cells, and feline calicivirus (feline calicivirus (F9 strain)) using CrFK cells. And cultured.

100 μl of a dispersion in which 1 mg of each sample was dispersed in 1 ml of PBS (Phosphate buffered saline) and 100 μl of virus solution were placed in a sterilized 1.5 ml tube and sensitized for 60 minutes while stirring at room temperature. After sensitization for 60 minutes, 800 μl of a surfactant-containing aqueous solution (lecithin polysorbate 80 added soy bean casein digest (SCDLP)) was added, and the virus was washed out by vortexing. Thereafter, the nanofibers were separated by centrifugation, and the supernatant was diluted with a MEM diluent until it became 10 ⁻² to 10 ⁻⁵ (10-fold serial dilution). 100 μL of the sample solution was inoculated on MDCK cells or CrFK cells cultured in a petri dish. Plaque formed by adsorbing virus to cells by standing for 60 minutes, overlaying 0.7% agar medium, culturing in 34 ° C, 5% CO ₂ incubator for 48 hours, fixing with formalin and staining with methylene blue The number was counted, and the virus infectivity titer (PFU / 0.1 ml, Log10); (PFU: plaque-forming units) was calculated. For the control, the value when the virus solution was added without using the sample of the example was used. Table 1 shows the results of virus evaluation for each example and comparative example.

  From the above results, it was confirmed that in all the Examples, the infectivity titer was lowered regardless of the presence or absence of the virus envelope. The inactivation rate for influenza virus was a high inactivation rate of 99.9998% (less than detection limit value) for highly effective and 99.9% or less for highly effective virus sensitization time of 60 minutes. It was. In particular, for feline calicivirus, the inactivation rate was 99.9998% or more (detection limit value or less) in all the examples, which was very effective. On the other hand, the virus inactivation performance of Comparative Example 1 was lower than that of nanofibers, such as 90% or more against influenza virus and 97.5% or more against feline calicivirus.

10: Monovalent copper oxide 20: Center part 100: Nanofiber having antiviral properties of this embodiment

Claims (3)

An antiviral material composed of nanofibers composed of copper and copper oxide, wherein the center of the nanofiber is copper, and at least the surface portion of the nanofiber has monovalent copper oxide Antiviral material.   2. The antiviral material according to claim 1, wherein the nanofiber has a fiber diameter of 10 nm or more and 100 nm or less, a fiber length of 100 nm or more and 100 μm or less, and an aspect ratio of 10 or more. . After copper is deposited in the pores of the porous body, copper nanofibers having a natural oxide film formed on the surface obtained by removing the porous body are immersed in an aqueous solution containing a reducing agent, A method for producing an antiviral material, comprising reducing at least part of the surface of a nanofiber to a monovalent copper compound having an antiviral effect.