JP2018035478A - Composite nanofiber, method of manufacturing composite nanofiber, and mask - Google Patents

Abstract

Disclosed is a composite nanofiber which is a fiber material having antibacterial properties, and a method for producing the composite nanofiber. Moreover, the mask which is a textile product using the composite nanofiber of this invention is provided. A composite nanofiber comprising: a silver silica nanocomposite obtained by adding silver particles having a diameter of 20 nm or less to silica particles having a diameter of 1000 nm or less; and nanofibers supporting the silver-silica nanocomposite. In addition, a composite preparation step of preparing a silver silica nanocomposite in which silver particles of a diameter of 20 nm or less are added to silica particles of a diameter of 1000 nm or less, and composite nanofibers for producing a composite nanofiber by supporting the silver silica nanocomposite on a nanofiber The manufacturing method of the composite nanofiber which includes a fiber manufacturing process in this order. [Selection] Figure 9

Description

  The present invention relates to a composite nanofiber having antibacterial action, a method for producing the composite nanofiber, and a mask using the composite nanofiber.

  2. Description of the Related Art Conventionally, a mask having a covering covering a nostril and a mounting member disposed on the covering is known. The covering includes a microfiber nonwoven fabric or woven fabric layer having an average fiber diameter of 1 to 100 μm, and a nanofiber nonwoven fabric layer having an average fiber diameter of 1 nm or more and less than 1000 nm, which is laminated on the microfiber nonwoven fabric or woven fabric layer. Further, the microfiber nonwoven fabric or the woven fabric layer contains an inorganic porous material (for example, see Patent Document 1).

  The conventional mask has the following effects. That is, since the covering constituting the mask includes the microfiber nonwoven fabric or woven fabric layer containing the inorganic porous material and the nanofiber nonwoven fabric layer, the microfiber nonwoven fabric or the woven fabric layer is used for bacteria and viruses in the air. It has both the effect of adsorbing fungi and killing / inactivating them, and the effect of collecting and removing these bacteria from the air with a nanofiber nonwoven fabric layer.

JP 2008-188082 A

  By the way, in the technical field of textile materials and textile products related to hygiene, in order to further reduce the risk of users suffering from infectious diseases, it is required to suppress the survival and proliferation of bacteria etc. on textile products. ing. That is, there is a demand for fiber materials and fiber products having antibacterial action.

  Then, this invention is made | formed in view of the said subject, and it aims at providing the manufacturing method of the composite nanofiber which is a fiber raw material which has antimicrobial property, and the said composite nanofiber. Another object of the present invention is to provide a mask that is a fiber product using the composite nanofiber of the present invention.

[1] The composite nanofiber of the present invention comprises a silver silica nanocomposite obtained by adding silver particles having a diameter of 20 nm or less to silica particles having a diameter of 1000 nm or less, and nanofibers supporting the silver silica nanocomposite. To do.

[2] In the composite nanofiber of the present invention, it is preferable that at least a part of the silver-silica nanocomposite is embedded in the nanofiber.

[3] The method for producing a composite nanofiber of the present invention comprises a composite preparation step of preparing a silver silica nanocomposite in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less, And a composite nanofiber preparation step of preparing composite nanofibers supported by the fibers in this order.

[4] In the method for producing a composite nanofiber of the present invention, the average diameter of the silica particles is preferably 100 nm or less.

[5] In the method for producing a composite nanofiber of the present invention, the average diameter of the silver particles is preferably 10 nm or less.

[6] In the method for producing a composite nanofiber of the present invention, in the composite preparation step, an orthosilicate organic compound is added to a reaction solution that is a basic alcohol solution, and then a silane coupling agent is added. Further, after that, the reaction solution is removed to obtain the silica particles, and the silica particles are dispersed in a dispersion solvent, and then a reducing agent and a silver ion compound are added to add the silver particles to the silica particles. It is preferable to include the silver particle addition step to be performed in this order.

[7] In the composite nanofiber manufacturing method of the present invention, in the composite nanofiber manufacturing step, at least a part of the silver silica nanocomposite is embedded in the nanofiber to manufacture the composite nanofiber. Is preferred.

[8] In the method for producing a composite nanofiber of the present invention, the composite nanofiber production step comprises dissolving a polymer material, which is a raw material of the nanofiber, in a solvent to produce a polymer solution, and then adding silver to the polymer solution. A spinning solution preparation process for preparing a spinning solution as a raw material of the composite nanofiber by adding a silica nanocomposite and stirring, and an electrospinning process for performing electrospinning using the spinning solution are included in this order. Is preferred.

[9] In the method for producing a composite nanofiber of the present invention, the polymer material preferably contains polyvinyl alcohol as a main component.

[10] In the method for producing a composite nanofiber of the present invention, in the spinning solution preparation step, glutaraldehyde is added to the spinning solution, and the composite nanofiber preparation step includes the nanofiber after the electrospinning step. It is preferable to further include an insolubilization step of performing an insolubilization treatment with respect to water.

[11] The mask of the present invention includes a covering covering the nostril and a mounting member disposed on the covering, and the covering includes silica particles having a diameter of 1000 nm or less and silver particles having a diameter of 20 nm or less. It is preferable to have a composite nanofiber nonwoven fabric composed of composite nanofibers comprising a silver-silica nanocomposite to which is added and nanofibers that support the silver-silica nanocomposite.

  Since the composite nanofiber of the present invention includes a silver-silica nanocomposite in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less, the composite is a fiber material having antibacterial properties as shown in an experimental example described later. It becomes nanofiber.

  According to the method for producing a composite nanofiber of the present invention, the composite nanofiber of the present invention, which is a fiber material having antibacterial properties, can be produced as shown in the experimental examples described later.

  Since the mask of the present invention is a fiber product using the composite nanofiber of the present invention, the mask has antibacterial properties and is excellent in hygiene.

It is a schematic diagram of the composite nanofiber 1 which concerns on embodiment. It is a flowchart of the manufacturing method of the composite nanofiber which concerns on embodiment. It is a schematic diagram of the composite nanofiber manufacturing apparatus 100 in embodiment. It is a figure shown in order to demonstrate the mask 10 which concerns on embodiment. It is a TEM image of the silver silica nanocomposite in an experimental example. It is a SEM image of the silver silica nanocomposite in an experimental example. It is a graph which shows the analysis result by EDS of the silver silica nanocomposite in an experiment example. It is a SEM image of the composite nanofiber which concerns on an experiment example, and the nanofiber for a comparison. It is a TEM image of the composite nanofiber which concerns on an experiment example. It is a graph which shows the analysis result by XRD of the composite nanofiber which concerns on an experiment example, and a comparative nanofiber. It is a photograph which shows the experimental result about the antibacterial property of the composite nanofiber which concerns on an experiment example. It is a graph which shows the experimental result about the antimicrobial property of the composite nanofiber which concerns on an experiment example.

  Hereinafter, the composite nanofiber, the manufacturing method of the composite nanofiber, and the mask according to the present invention will be described.

1. Composite nanofiber 1 according to the embodiment
Drawing 1 is a mimetic diagram of composite nanofiber 1 concerning an embodiment. FIG. 1 shows a cross-sectional view of the composite nanofiber 1.
As shown in FIG. 1, the composite nanofiber 1 according to the embodiment is a silver silica nanocomposite (Silver / silica nanocomposite, also referred to as SNC) 2 in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less. And nanofibers 3 supporting the silver-silica nanocomposite 2.
The “nanofiber” in the present specification refers to a fiber having a nanoscale diameter (fiber having an average fiber diameter of approximately 3000 nm or less, preferably 1000 nm or less).

If the structure as a fiber remains, the composite nanofiber 1 which concerns on embodiment can be made into various forms. For example, it may be used as a single fiber, may be used as a yarn obtained by twisting a plurality of fibers, or may be used as a nonwoven fabric. In particular, when used for a textile product such as a mask 10 described later, a composite nanofiber 1 according to the embodiment made of a nonwoven fabric can be suitably used.
In the composite nanofiber 1, at least a part of the silver silica nanocomposite 2 is embedded in the nanofiber 3.

In the embodiment, the average diameter of the silica particles is 100 nm or less, and the average diameter of the silver particles is 10 nm or less. A method for obtaining such a silver-silica nanocomposite 2 will be described in the item of a method for producing a composite nanofiber.
In addition, the particle diameter of a silica particle is larger than the particle diameter of a silver particle.

The nanofiber 3 uses a polymer material as a main raw material. Polymer materials include polyvinyl alcohol (PVA), polypropylene (PP), polyvinyl acetate (PVAc), polyethylene terephthalate (PET), polybutylene terephthalate (PB), polyethylene naphthalate (PEN), polyamide (PA), polyurethane ( PUR), polyacrylonitrile (PAN), polyetherimide (PEI), polylactic acid (PLA), polycaprolactone (PCL), protein fibers (silk, collagen, etc.), chitosan, etc., alone or in combination Can be used. As the polymer material, polyvinyl alcohol (hereinafter sometimes simply referred to as “PVA”) is preferably the main component. The polymer material constituting the nanofiber 3 in the embodiment is PVA.
In the present specification, the “main component” in a polymer material refers to a polymer material that occupies most (for example, 80% or more by weight) of all polymer materials constituting the nanofiber.

The nanofiber 3 may contain additives other than the polymer material.
When the polymer material contains PVA as a main component, it is preferable that the nanofibers 3 have been insolubilized with water. The insolubilization treatment can be performed by, for example, adding glutaraldehyde to a polymer material and electrospinning, and then reacting nanofibers with hydrogen chloride.

The amount of the silver silica nanocomposite 2 can be, for example, 1 wt% or more with respect to the nanofibers 3 by weight. From the viewpoint of obtaining sufficient antibacterial properties, the amount of the silver silica nanocomposite 2 is preferably 3 wt% or more, more preferably 5 wt% or more with respect to the nanofibers 3.
Moreover, the quantity of the silver silica nanocomposite 2 can be 30 wt% or less by weight ratio with respect to the nanofiber 3, for example. From the viewpoint of preventing excessive aggregation of the silver-silica nanocomposite 2 during production, the amount of the silver-silica nanocomposite 2 is preferably 20 wt% or less with respect to the nanofibers 3. More preferably, it is 15 wt% or less.

2. FIG. 2 is a flowchart of a method for producing a composite nanofiber according to an embodiment.
FIG. 3 is a schematic diagram of the composite nanofiber manufacturing apparatus 100 in the embodiment. FIG. 3 shows a state when electrospinning is performed.

  As shown in FIG. 2, the method for producing a composite nanofiber according to the embodiment includes a composite preparation step S10 and a composite nanofiber preparation step S20 in this order. Hereinafter, each step will be described.

The composite preparation step S10 is a step of preparing a silver silica nanocomposite 2 in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less. In the embodiment, the average diameter of the porous silica particles is 100 nm or less, and the average diameter of the silver particles is 10 nm or less.
The composite preparation step S10 includes a silica particle preparation step S12 and a silver particle addition step S14 in this order.

The silica particle preparation step S12 is a step of adding an orthosilicate organic compound to a reaction solution that is a basic alcohol solution, adding a silane coupling agent, and then removing the reaction solution to obtain silica particles. .
In the present specification, the “basic alcohol solution” refers to an alcohol solution containing a basic substance. The basic alcohol solution may further contain water or substances other than those described above as long as it has sufficient reactivity.
As the basic substance, for example, aqueous ammonia (ammonium hydroxide), potassium hydroxide, sodium hydroxide and the like can be used. As the basic substance, aqueous ammonia can be particularly preferably used because of its easy removal after the reaction.
As the alcohol, ethanol can be preferably used.

In the present specification, the “orthosilicate organic compound” refers to a compound having a structure in which an alkyl group is bonded to an orthosilicate ion (SiO ₄ ⁴⁻ ). As the orthosilicate organic compound, tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS) can be suitably used.
In the present specification, the “silane coupling agent” refers to a coupling (binding) agent having silane as a core. As the silane coupling agent, a mercapto silane coupling agent such as 3-mercaptopropyltrimethoxysilane or an amino silane coupling agent such as 3-aminopropyltrimethoxysilane can be preferably used. . As the silane coupling agent, 3-mercaptopropyltrimethoxysilane can be particularly preferably used from the viewpoint of reaction efficiency.

“Removing the reaction solution” means removing the basic ions and unreacted substances contained in the reaction solution by removing the reaction solution used to obtain the silica particles. The silica particles obtained in the silica particle preparation step S12 (used in the next silver particle addition step S14) are in the form of a mixture with some solvent (a solvent that is not a reaction solvent) if the reaction solvent is sufficiently removed. May be.
The reaction solution can be removed by, for example, centrifugation using an appropriate solvent. As the solvent used for removing the reaction solution, alcohols, particularly ethanol can be preferably used.

The silver particle addition step S14 is a step of adding silver particles to the silica particles by adding a reducing agent and a silver ion compound after dispersing the silica particles in the dispersion solvent.
As the dispersion solvent, alcohols, particularly ethanol can be preferably used. For dispersion, mechanical stirring or ultrasonic waves can be used.
As used herein, “reducing agent” refers to a reagent for reducing silver ions to form metallic silver. In the present specification, the “silver ion compound” refers to a compound containing silver ions (for example, a silver salt).
As the reducing agent and the silver ion compound, for example, when the dispersion solvent is ethanol, for example, polyvinylpyrrolidone and silver (I) nitrate can be preferably used, respectively.
In the embodiment, the silver silica nanocomposite 2 can be obtained by the silver particle addition step S14.

The composite nanofiber manufacturing step S20 is a step of manufacturing the composite nanofiber 1 by supporting the silver silica nanocomposite 2 on the nanofiber 3.
In the composite nanofiber manufacturing step S20 according to the embodiment, at least a part of the silver silica nanocomposite 2 is embedded in the nanofiber 3 to manufacture the composite nanofiber 1. The composite nanofiber production step S20 includes a spinning solution production step S22, an electrospinning step S24, and an insolubilization step S26 in this order.

In the spinning solution preparation step S22, a polymer material that is a raw material of the nanofiber 3 is dissolved in a solvent to prepare a polymer solution, and then the silver silica nanocomposite 2 is added to the polymer solution and stirred, whereby the composite nanofiber 1 This is a process for producing a spinning solution as a raw material.
As the polymer material, various materials can be used as described in the description of the composite nanofiber 1. In an embodiment, the polymer material is PVA. In the embodiment, glutaraldehyde is added to the spinning solution for the subsequent insolubilization step S26.

  The electrospinning step S24 is a step of performing electrospinning using a spinning solution. Electrospinning process S24 can be implemented using an apparatus as shown in FIG. 3, for example.

In FIG. 3, reference numeral 6 denotes a spinning solution, reference numeral 102 denotes a solution tank into which the spinning solution is put, reference numeral 104 denotes a valve, reference numeral 106 denotes a nozzle, reference numeral Reference numeral 108 denotes a collector, and reference numeral 110 denotes a power supply device.
In the embodiment, the composite nanofiber 1 can be obtained as a non-woven fabric 8 deposited on the collector 108. The composite nanofiber 1 may be used as it is as the non-woven fabric 8, or may be used after being drawn out for each fiber to be used as a yarn, or may be used after being processed by twisting the entire non-woven fabric 8 into a yarn. Also good.
In FIG. 3, a flat plate is described as the collector 108, but the present invention is not limited to this. As the collector, a drum-like and rotatable one, or a belt-conveyor-like rotatable one (that is, one capable of continuously producing a long nonwoven fabric) may be used.

Insolubilization process S26 is a process performed after electrospinning process S24, and is a process of performing insolubilization processing to nanofiber 3 to water. Insolubilization process S26 can be implemented by exposing the composite nanofiber 1 to hydrogen chloride, for example.
The term “insolubilization” in the present specification refers to lowering the solubility in the liquid than before performing the insolubilization treatment, and does not mean to completely eliminate the solubility in the liquid. As long as there is no problem in use, a certain degree of solubility may remain.

  Through the above steps, the composite nanofiber 1 according to the embodiment can be manufactured.

3. Mask According to Embodiment FIG. 4 is a view for explaining the mask 10 according to the embodiment. 4A is a front view of the mask 10, FIG. 4B is a cross-sectional view taken along plane A1-A1 in FIG. 4A, and FIG. 4C is B1 in FIG. 4A. It is sectional drawing in -B1 surface

As shown in FIG. 4, the mask 10 according to the embodiment includes a rectangular covering body 20 that covers the nostril, and a string 30 as a mounting member disposed on the short side of the covering body 20.
The covering body 20 is a composite body 40 composed of a plurality of rectangular laminated bodies, and the outer peripheral portion thereof is thermocompression bonded with the belt-like nonwoven fabrics 50 and 60 and integrated. The outer peripheral portion on the long side of the composite 40 is thermocompression bonded by embossing in a state covered with the strip-shaped nonwoven fabric 50, and the outer peripheral portion on the short side of the composite is embossed in a state covered with the strip-shaped nonwoven fabric 60. Is thermocompression-bonded.
A plurality of thermocompression bonding portions 52 and 62 that are embossed are formed on the outer peripheral portions of the belt-shaped nonwoven fabrics 50 and 60. In addition, a plurality of pleats are formed along the long side direction of the covering body 20, and both end portions of each pleat are fixed by a strip-shaped nonwoven fabric 60.

The covering 20 includes a silver silica nanocomposite in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less, and the silver silica nanocomposite as at least one laminate of a plurality of rectangular laminates. It has the composite nanofiber nonwoven fabric which consists of composite nanofiber provided with the nanofiber which supports a body.
The composite nanofiber nonwoven fabric is preferably arranged on the front surface (outer surface) side when the mask 10 is worn on the human body.

  The covering 20 is a laminate comprising a plurality of laminates, usually a laminate made of a nonwoven fabric of fibers (microfibers, etc.), a laminate made of a nanofiber nonwoven fabric different from the above-described composite nanofiber nonwoven fabric, etc. May further be included.

The stack of the normal fibers of the nonwoven fabric, for example, a nonwoven fabric manufactured by a melt blown method or spunbond method, basis weight be suitably used within the range of 10g ^/ m ² ~50g / m 2 Can do. In addition, the fiber which comprises the nonwoven fabric which consists of a normal fiber may be any of a natural fiber (for example, cellulose), a synthetic fiber (for example, polypropylene, polyethylene, polyurethane, polyamide, polyethylene terephthalate, etc.), and these mixed fibers. .

  As a laminated body which consists of a nanofiber nonwoven fabric different from a composite nanofiber nonwoven fabric, what a nanofiber consists of a polyurethane, polyvinyl alcohol, polyamide, or polyvinylidene fluoride can be used suitably, for example. The average fiber diameter is preferably in the range of 50 nm to 300 nm. When the average fiber diameter is less than 50 nm, it may be difficult to form the nanofiber nonwoven fabric by the electrospinning method. Moreover, when an average fiber diameter exceeds 300 nm, the specific surface area of a nanofiber nonwoven fabric becomes small, and the collection efficiency of the liquid of a mask 10, a harmful particle, a virus, etc. may fall.

4). Effects of Composite Nanofiber 1, Composite Nanofiber Manufacturing Method, and Mask 10 According to Embodiments Hereinafter, the composite nanofiber 1, the manufacturing method of the composite nanofiber, and the effects of the mask 10 according to the embodiment are described.

  Since the composite nanofiber 1 according to the embodiment includes the silver-silica nanocomposite 2 in which silver particles having a diameter of 20 nm or less are added to silica particles having a diameter of 1000 nm or less, as shown in an experimental example to be described later, a fiber material having antibacterial properties It becomes a composite nanofiber.

  Moreover, according to the composite nanofiber 1 which concerns on embodiment, since silver particle is added to the silica particle, compared with the case where nanosized silver particle is used as it is, there is a risk that silver particle is released to the environment. It becomes possible to reduce.

  Moreover, according to the composite nanofiber 1 which concerns on embodiment, since at least one part of the silver silica nanocomposite 2 is embedded in the inside of the nanofiber 3, by preventing the drop of the silver silica nanocomposite from a nanofiber, It becomes possible to exhibit antibacterial properties over a long period of time, and to further reduce the risk of nano-sized silver particles being released to the environment.

  According to the manufacturing method of the composite nanofiber which concerns on embodiment, it becomes possible to manufacture the composite nanofiber 1 which concerns on embodiment which is a fiber raw material which has antibacterial property.

  Moreover, according to the manufacturing method of the composite nanofiber which concerns on embodiment, since the composite nanofiber 1 is manufactured using the silver silica nanocomposite 2, compared with the case where a nanosized silver particle is used as it is, silver particle is The risk of being released to the environment can be reduced.

  Further, according to the method for producing a composite nanofiber according to the embodiment, since the average diameter of the porous silica particles is 100 nm or less, the specific surface area of the silica particles can be sufficiently increased, and as a result, sufficient It becomes possible to carry an amount of silver particles and to have sufficient antibacterial properties.

  Further, according to the method for producing a composite nanofiber according to the embodiment, since the average diameter of the silver particles is 10 nm or less, the specific surface area of the silver particles can be sufficiently increased, and as a result, the reaction of the silver particles It is possible to sufficiently increase the property and to have sufficient antibacterial properties.

  Moreover, according to the composite nanofiber manufacturing method according to the embodiment, the composite preparation step S10 adds an orthosilicate organic compound to a reaction solution that is a basic alcohol solution, and then adds a silane coupling agent. Further, after that, the silica particle preparation step of removing the reaction solution to obtain silica particles and dispersing the silica particles in the dispersion solvent, and then adding the reducing agent and the silver ion compound to add the silver particles to the silica particles. Since the additional steps are included in this order, highly uniform silica particles, silver particles, and silver-silica nanocomposites can be stably produced, and high-quality composite nanofibers can be produced.

  Moreover, according to the composite nanofiber manufacturing method according to the embodiment, in the composite nanofiber manufacturing step, at least a part of the silver silica nanocomposite 2 is embedded in the nanofiber 3 to manufacture the composite nanofiber 1. It becomes possible to produce the composite nanofiber 1 that can exhibit antibacterial properties for a long period of time and can further reduce the risk that nano-sized silver particles are released to the environment. .

  Further, according to the method for producing a composite nanofiber according to the embodiment, since the spinning solution preparation step S22 and the electrospinning step S24 are included in this order, at least a part of the silver silica nanocomposite is embedded in the nanofiber. It is possible to produce composite nanofibers.

  In addition, according to the method for producing a composite nanofiber according to the embodiment, since the polymer material contains polyvinyl alcohol as a main component, it is possible to use water, which is a solvent having a low environmental load, as a solvent for spinning.

  Further, according to the method for producing a composite nanofiber according to the embodiment, glutaraldehyde is added to the spinning solution in the spinning solution preparation step S22, and the composite nanofiber preparation step S20 is performed on the nanofiber 3 after the electrospinning step S24. Since the insolubilization process S26 which performs the insolubilization process with respect to water is included, the solubility of nanofibers in water can be lowered by the insolubilization process, and the durability of the composite nanofiber can be increased.

  Since the mask according to the embodiment is a fiber product using the composite nanofiber 1 according to the embodiment, the mask has antibacterial properties and is excellent in hygiene.

[Experimental example]
In the experimental example, the composite nanofiber of the present invention was actually manufactured according to the method of manufacturing the composite nanofiber of the present invention, and its form and effect were confirmed.

1. Raw materials and apparatus used in the experimental example First, the raw materials and apparatus used in the experimental example will be described. In addition, description is abbreviate | omitted about a general purpose laboratory instrument and experiment apparatus.

  The raw materials, solvents and reagents used in the experimental examples were purchased as they were purchased through Sigma-Aldrich Japan.

As a power supply device in electrospinning, Har-100 * 12 of Matsusada Precision Co., Ltd. was used.
As a collector used for electrospinning, a grounded rotary drum collector was used. The rotary drum collector was covered with a commercially available cooking sheet, and electrospinning was performed thereon.
As a syringe pump for uniformizing the discharge amount of the spinning solution, KDS-100 manufactured by kd Scientific, USA was used.

As a scanning electron microscope (SEM), S-3000N manufactured by Hitachi High-Technologies Corporation was used.
As a transmission electron microscope (TEM), 2010 FasTEM of JEOL Ltd. was used.
As an X-ray diffractometer (XRD), Rotaflex RTP300 manufactured by Rigaku Corporation was used.

In experiments regarding antibacterial properties, reagents, culture media, and experimental instruments were used as defined by the general Kirby-Bauer method (disc diffusion method).
As bacteria, E. coli which is a Gram-negative bacterium. E. coli (ATCC 25922), Salmonella enterica serotype Typhimurium (IFO 12529), Shigella dysenteriae (ATCC 13313), and Gram-positive S. aureus coty
Image J (v. 1.4.8) was used as image analysis software.

2. Next, the manufacturing method of the composite nanofiber which concerns on an experiment example is demonstrated.
The manufacturing method of the composite nanofiber according to the experimental example is basically the same as the manufacturing method of the composite nanofiber according to the embodiment, and includes a composite preparation step and a composite nanofiber manufacturing step in this order.

(1) Composite preparation step (1-1) Silica particle preparation step First, 21.2 g of 25% aqueous ammonia and 250 g of ethanol were mixed to prepare a reaction solution, which was stirred for 20 minutes. Thereafter, 10 g of tetraethyl orthosilicate (tetraethylorthosilicate) was added to the mixed solution, and the mixture was further stirred for 1 hour. Thereafter, 2 g of 3-mercaptopropyltrimethoxysilane was added and further stirred for 6 hours. All the above steps were performed at 40 ° C. Thereafter, in order to remove the reaction solvent, centrifugation at 10,000 rpm for 15 minutes was performed three times to obtain silica particles.

(1-2) Silver Particle Addition Step Next, the entire amount of silica particles obtained in the silica particle preparation step was added to 96 g of a dispersion solvent (ethanol) and subjected to ultrasonic treatment and stirring to be dispersed. Thereafter, 4 g of polyvinylpyrrolidone (PVP K15) was added and stirred for 2 hours. Thereafter, the weight of the silica particles is calculated from the amount of silicon used in the silica particle preparation step, and silver nitrate (AgNO ₃ ) so that the weight of the silver particles in the silver silica nanocomposite is 11000 ppm when the silver silica nanocomposite is obtained. And stirred for 6 hours.
Thereafter, centrifugation at 10000 rpm for 15 minutes was performed twice to obtain a silver silica nanocomposite. The obtained silver silica nanocomposite was redispersed and stored in 100 mL of water.

(2) Composite nanofiber preparation step (2-1) Spinning solution preparation step First, an 8% aqueous solution of PVA (hydrolysis degree: 87 to 89%, Mn: 85000 to 124000) was prepared. After adding PVA to water and stirring at room temperature for 24 hours, a 50% glutaraldehyde aqueous solution was added to the PVA aqueous solution so that glutaraldehyde was 22 wt% with respect to PVA, and the mixture was further stirred for 3 hours.
Thereafter, a silver silica nanocomposite was further added to prepare a spinning solution. The spinning solution includes 5 wt% of silver silica nanocomposite with respect to PVA, 10 wt% of silver silica nanocomposite with respect to PVA, and 15% of silver silica nanocomposite with respect to PVA. Three types of things were made.

(2-2) Electrospinning process The electrospinning apparatus used in the electrospinning process was almost the same as the electrospinning apparatus shown in FIG. 3, but a rotating drum collector covered with a cooking sheet was used as a collector.
First, the spinning solution was injected into a 5 mL plastic syringe equipped with a capillary tip (inner diameter: 0.7 mm), and a copper wire connected to the anode was inserted into the solution to perform electrospinning. A pump was used to control the flow rate, and the solution was supplied at a rate of 0.1 mL / min. The distance between the tip and the collector was 12 cm, and the applied voltage was 12 kV.
After electrospinning, the produced composite nanofiber was dried at room temperature for 2 days.
Moreover, the nanofiber which does not use a silver silica nanocomposite was also produced for comparison.

(2-3) Insolubilization process The composite nanofiber prepared in the electrospinning process and the nanofiber not using the silver-silica nanocomposite (hereinafter referred to as a sample in this paragraph) are separated from the cooking sheet and then concentrated hydrochloric acid. (37% aqueous solution) was subjected to insoluble treatment by exposure to volatile hydrogen chloride. Specifically, an appropriate amount of concentrated hydrochloric acid was placed in a 100 mL glass beaker, and the sample was placed 2 inches (about 5 cm) above the beaker. After insolubilization treatment was performed for 60 seconds on one side, insolubilization treatment was further performed for 30 seconds on the other side. After the insolubilization treatment, the sample was left at room temperature for 30 minutes. Thereafter, each sample was sealed and stored in a plastic container.

Through the above steps, the composite nanofiber according to the experimental example and the nanofiber for comparison were manufactured.
In the following description, among the produced composite nanofibers, the silver silica nanocomposite having a concentration of 5% is 5% composite nanofiber, 10% is 10% composite nanofiber, and 15% is 15%. % Composite nanofiber.
Moreover, in the following description, the nanofiber which does not contain a silver silica nanocomposite is described as a comparative nanofiber. In addition, the comparative nanofiber was manufactured by the same manufacturing method as the above-described manufacturing method of the composite nanofiber except that the silver silica nanocomposite was not used.

3. Observation and Results First, the silver silica nanocomposite was observed by TEM.
FIG. 5 is a TEM image of the silver-silica nanocomposite in the experimental example. 5 (a) and FIG. 5 (b) have different magnification rates, and FIG. 5 (b) has a higher magnification rate.
By TEM observation, as shown in FIG. 5, it was confirmed that silver particles were attached to the outside of the large silica particles. When calculated from the photograph, the average diameter of the silica particles was 90 nm, and the average diameter of the silver particles was 3 to 5 nm.

Next, the silver silica nanocomposite was observed and analyzed by SEM and EDS (energy dispersive X-ray spectrometer associated with SEM).
FIG. 6 is an SEM image of the silver-silica nanocomposite in the experimental example.
FIG. 7 is a graph showing the analysis result by EDS of the silver silica nanocomposite in the experimental example. The vertical axis in FIG. 7 indicates the X-ray intensity (unit: count), and the horizontal axis indicates the X-ray energy (unit: keV).

As a result of observation by SEM, it was confirmed that the silver silica nanocomposite had a uniform outer shape as shown in FIG.
As a result of analysis by EDS, it was confirmed that Ag, Si, and O were the main components as shown in FIG.

Next, 5% composite nanofiber, 10% composite nanofiber, 15% composite nanofiber and comparative nanofiber were observed by SEM.
FIG. 8 is an SEM image of the composite nanofiber and the comparative nanofiber according to the experimental example. FIG. 8A is an SEM image of a comparative nanofiber, FIG. 8B is an SEM image of a 5% composite nanofiber, and FIG. 8C is an SEM image of a 10% composite nanofiber, FIG. 8 (d) is an SEM image of 15% composite nanofiber.
As a result of observation by SEM, as shown in FIG. 8, both the composite nanofiber and the comparative nanofiber were uniform, the surface was smooth, and no bead-like structure was observed.

Next, 5% composite nanofiber, 10% composite nanofiber, and 15% composite nanofiber were observed by TEM.
FIG. 9 is a TEM image of the composite nanofiber according to the experimental example. 9 (a) and 9 (b) are TEM images of 5% composite nanofibers, and FIG. 9 (c) and FIG. 9 (d) are TEM images of 10% composite nanofibers. ) And FIG. 9 (f) are TEM images of 15% composite nanofibers. 9A and 9B, FIG. 9C and FIG. 9D, and FIG. 9E and FIG. 9F are images with different magnifications.
As a result of observation by TEM, as shown in FIG. 9, it was confirmed that the silver silica nanocomposite was embedded in the nanofiber in all the composite nanofibers.

Next, 5% composite nanofiber, 10% composite nanofiber, 15% composite nanofiber and comparative nanofiber were observed by XRD.
FIG. 10 is a graph showing the analysis results by XRD of the composite nanofiber and the comparative nanofiber according to the experimental example. The vertical axis of the graph shown in FIG. 10 indicates intensity (unit: arbitrary unit), and the horizontal axis indicates 2θ (unit: °). In FIG. 10, a reference A indicates a graph of comparative nanofibers, a reference B indicates a graph of 5% composite nanofibers, and a reference C indicates a graph of 10% composite nanofibers. , D represents a graph of 15% composite nanofibers.
As a result of observation by XRD, as shown in FIG. 10, a peak peculiar to PVA was observed at 19.33 ° in all composite nanofibers and comparative nanofibers. In addition, about silver particle, since the diameter was too small, the peak was not able to be observed.

Next, an experiment on antibacterial properties was conducted on 5% composite nanofibers, 10% composite nanofibers, 15% composite nanofibers and comparative nanofibers.
FIG. 11 is a photograph showing experimental results on the antibacterial properties of the composite nanofiber according to the experimental example. FIG. 11 (a) is a photograph showing the result of the comparative nanofiber, FIG. 11 (b) is a photograph showing the result of the 5% composite nanofiber, and FIG. 11 (c) is the result of the 10% composite nanofiber. FIG. 11 (d) is a photograph showing the result of 15% composite nanofiber. For convenience of photography, only FIG. 11A is shown larger than the other photos. A white object shown in FIG. 11A is a sample. Further, in FIGS. 11B to 11D, a circular object whose outline is indicated by a broken line is a sample, and a region (including the sample itself) surrounded by a circular boundary outside the sample is a fungus. It is a growth prevention area.
FIG. 12 is a graph showing experimental results on the antibacterial properties of the composite nanofiber according to the experimental example. The vertical axis | shaft of the graph shown in FIG. 12 shows the area (unit: mm < ² >) of a fungal growth inhibition area | region (inhibition zone). In FIG. 12, a reference A indicates a graph of comparative nanofibers, a reference B indicates a graph of 5% composite nanofibers, and a reference C indicates a graph of 10% composite nanofibers. , D represents a graph of 15% composite nanofibers. In addition, about the nanofiber for a comparison, the fungal growth inhibition area | region was not able to be confirmed (after-mentioned), but in FIG. 12, the area of a sample is described as a fungal growth inhibition area | region for convenience.

Experiments on antibacterial properties were performed based on the Kirby-Bauer method (disk diffusion method). First, the samples used in the experiment (each non-woven fabric made of composite nanofibers and comparative nanofibers cut so as to be approximately circular and 80 mm ² ) are placed on a prescribed LB agar plate medium added with logarithmic bacteria. And overnight culture at 37 ° C. Thereafter, the area where the bacteria did not grow due to the antibacterial property of the composite nanofiber, that is, the area of the bacteria growth inhibition area was analyzed with image analysis software.

As a result, as shown in FIG. 11 (a), the growth inhibition region could not be confirmed in the comparative nanofiber, but in each composite nanofiber as shown in FIG. 11 (b) to FIG. 11 (d) The blocking area was confirmed. That is, antibacterial properties were confirmed for all the composite nanofibers.
Moreover, as shown in FIG. 12, when the magnitude | size of the fungal growth inhibition area | region was computed, it has confirmed that there exists a tendency for antimicrobial property to be high, so that the density | concentration of a silver silica nanocomposite is high.

4). Conclusion From the above experimental examples, it was confirmed that the composite nanofiber of the present invention can be surely manufactured by the method of manufacturing the composite nanofiber of the present invention.
Moreover, it has confirmed that the composite nanofiber of this invention has antibacterial property.

  As mentioned above, although the composite nanofiber of this invention, the manufacturing method of the said composite nanofiber, and the mask were demonstrated based on embodiment and an experiment example, this invention is not limited to this, The range which does not deviate from the summary For example, the following modifications are possible.

(1) The composite nanofiber of the present invention can also be applied to fiber materials and fiber products related to hygiene other than masks. Examples of such fiber materials and textile products include lab coats, surgical gowns, hats, gloves and mattresses.

DESCRIPTION OF SYMBOLS 1 ... Composite nanofiber, 2 ... Silver silica nanocomposite, 3 ... Nanofiber, 6 ... Raw material solution, 8 ... Nonwoven fabric, 10 ... Mask, 20 ... Covering body, 30 ... String, 40 ... Composite, 50, 60 ... Strip Nonwoven fabric, 52, 62 ... thermocompression bonding part, 100 ... composite nanofiber manufacturing device, 102 ... solution tank, 104 ... valve, 106 ... nozzle, 108 ... collector, 110 ... power supply device

Claims (11)

A silver-silica nanocomposite obtained by adding silver particles having a diameter of 20 nm or less to silica particles having a diameter of 1000 nm or less;
A composite nanofiber comprising a nanofiber supporting the silver-silica nanocomposite. The composite nanofiber according to claim 1,
At least a part of the silver-silica nanocomposite is embedded in the nanofiber. A composite preparation step of preparing a silver silica nanocomposite obtained by adding silver particles having a diameter of 20 nm or less to silica particles having a diameter of 1000 nm or less;
A method for producing a composite nanofiber, comprising: a composite nanofiber production step of producing a composite nanofiber by supporting the silver silica nanocomposite on a nanofiber in this order. In the manufacturing method of the composite nanofiber according to claim 3,
The method for producing a composite nanofiber, wherein the silica particles have an average diameter of 100 nm or less. In the manufacturing method of the composite nanofiber according to claim 3 or 4,
The average diameter of the silver particles is 10 nm or less. In the manufacturing method of the composite nanofiber in any one of Claims 3-5,
The composite preparation step includes
A silica particle preparation step of adding an orthosilicate organic compound to a reaction solution that is a basic alcohol solution, then adding a silane coupling agent, and then removing the reaction solution to obtain the silica particles;
A composite nanofiber comprising: a silver particle addition step of adding silver particles to the silica particles by adding a reducing agent and a silver ion compound after dispersing the silica particles in a dispersion solvent in this order. Production method. In the manufacturing method of the composite nanofiber in any one of Claims 3-6,
In the composite nanofiber manufacturing step, the composite nanofiber is manufactured by embedding at least a part of the silver-silica nanocomposite in the nanofiber. In the manufacturing method of the composite nanofiber according to claim 7,
The composite nanofiber manufacturing process includes:
A polymer solution, which is a raw material of the nanofiber, is dissolved in a solvent to prepare a polymer solution, and then a silver silica nanocomposite is added to the polymer solution and stirred to prepare a spinning solution, which is a raw material of the composite nanofiber. A spinning solution preparation process,
A method for producing a composite nanofiber comprising an electrospinning step of performing electrospinning using the spinning solution in this order. In the manufacturing method of the composite nanofiber according to claim 7 or 8,
The method for producing a composite nanofiber, wherein the polymer material contains polyvinyl alcohol as a main component. In the manufacturing method of the composite nanofiber according to claim 9,
In the spinning solution preparation step, glutaraldehyde is added to the spinning solution,
The composite nanofiber manufacturing process further includes an insolubilization process for insolubilizing the nanofiber with water after the electrospinning process. A covering covering the nostril, and a mounting member disposed on the covering,
The covering is a composite nanofiber nonwoven fabric comprising a composite nanofiber comprising a silver silica nanocomposite obtained by adding silver particles having a diameter of 20 nm or less to silica particles having a diameter of 1000 nm or less, and nanofibers supporting the silver silica nanocomposite. A mask characterized by having a mask.