Antibacterial fiber product and method for producing antibacterial fiber product

Abstract

To obtain an antimicrobial fiber product having a substance having antimicrobial activity on the surface and to provide a method for producing the fiber product.SOLUTION: According to one embodiment of the present invention, there is provided an antimicrobial fiber product comprising a fiber containing a thermoplastic resin at least on the surface thereof, and particles carried on the surface side of the fiber and containing a nitride. Further, there is provided a method for producing an antimicrobial fiber product, which comprises a step of preparing a fiber containing a thermoplastic resin at least on the surface thereof and particles containing a nitride, and a step of bringing the particles in a heated state into contact with the fiber to support the particles on the surface of the fiber, thereby obtaining the antimicrobial fiber product.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an antibacterial textile product and a method for producing the antibacterial textile product. [Background technology]

[0002] Patent Documents 1 and 2 describe the production of fibers from a mixed solution of a substance having antibacterial activity and a polymer material. As the substance having antibacterial activity, Patent Document 1 uses catalyst particles whose surface is coated with an inert substance, while Patent Document 2 uses a metal or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-145140 [Patent Document 2] Special Publication No. 2014-505801 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the fibers in Patent Documents 1 and 2 are in a mixture state with a substance having antibacterial activity, and there is a risk that the antibacterial activity of the substance may not be fully exhibited. Furthermore, neither document presents experimental results that specifically identify the substance and polymer material having antibacterial activity, and it is unclear whether the mixture can exhibit antibacterial properties or how antibacterial properties are exhibited. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided an antibacterial textile product having fibers containing a thermoplastic resin at least on the surface thereof, and particles containing nitrides carried on the surface side of the fibers.

[0006] According to this embodiment, an antibacterial textile product having a substance with antibacterial activity on the surface thereof can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a graph showing the measurement results of particle size distribution. [Figure 2] A scanning electron microscope image of the cross section of sample No. 1 is shown. [Figure 3] A scanning electron microscope image of the cross section of sample No. 2 is shown. [Figure 4] A scanning electron microscope image of the cross section of sample No. 3 is shown. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Various features shown in the following embodiment can be combined with each other. [Antibacterial textile products] First, the antibacterial textile product according to the present disclosure will be described. The antibacterial textile product has fibers containing a thermoplastic resin at least on the surface thereof, and particles carried on the surface side of the fibers. In this embodiment, an antibacterial fiber sheet will be described as an antibacterial fiber product. In this case, the fiber is a fiber sheet, and the fiber sheet is made of single fibers including monofilaments or multifilaments.

[0009] The fiber sheet may be a woven fabric, a nonwoven fabric, a knitted fabric, or the like, but a nonwoven fabric is preferred. Nonwoven fabrics are advantageous in that their thickness, basis weight, and other design parameters can be flexibly changed, allowing the antibacterial fiber sheet to be given the desired properties depending on its intended use. Furthermore, because they are generally porous, they are easily applicable to applications such as medical filters. Furthermore, because they have little directionality and do not fray, they have the advantage of being able to be cut into the desired shape for use.

[0010] The single fiber contains a thermoplastic resin at least on its surface. The configuration of the single fiber is not particularly limited as long as it contains a thermosetting resin at least on its surface, but the following describes a case where the single fiber has an inner layer that functions as the core of the single fiber (fiber body) and an outer layer that covers the inner layer. The outer layer is made of a material containing a thermoplastic resin. Examples of thermoplastic resins include polyethylene, polypropylene, polyamide, polyester, polylactic acid, polyvinyl chloride, polyacrylonitrile, ABS resin, polybutylene, polyether ether ketone, polyphenylene sulfide, polyetherimide, polyamideimide, aromatic polyamide (aramid), and polysulfone. One type of thermoplastic resin may be used alone, or two or more types may be used in combination.

[0011] The proportion of the thermoplastic resin in the outer layer is preferably about 40% by mass or more, more preferably about 50% by mass or more, even more preferably about 60% by mass or more, about 70% by mass or more, and particularly preferably about 80% by mass or more, or about 90% by mass or more, which allows particles to be firmly supported on the surface side of the fiber sheet, as described below. The proportion of the thermoplastic resin contained in the outer layer may be about 100% by mass or less, about 95% by mass or less, about 80% by mass or less, or about 60% by mass or less, thereby improving the heat resistance of the fiber sheet. In addition to thermoplastic resins, the outer layer may contain, for example, chemical fiber materials such as cellulose compounds (such as regenerated cellulose), glass, carbon, and metal, natural fiber materials such as plants, animals (hair), cocoons, and feathers, and mixtures thereof.

[0012] The constituent material of the inner layer is not particularly limited, but examples include synthetic fiber materials such as thermoplastic resins, cellulose compounds (such as regenerated cellulose), glass, carbon, and metal, and natural fiber materials such as plants, animals (hair), cocoons, and feathers. When the single fiber has a circular cross section, the ratio of the thickness of the outer layer to its average radius is not particularly limited, but may be about 0.001 to 0.999, about 0.1 to 0.9, or about 0.3 to 0.7. When a single fiber does not have a circular cross section, the average radius can be considered to be, for example, half the average area-equivalent circle diameter of the cross section. In this case, the cross section of the single fiber may be, for example, a rounded polygon, an ellipse, a star, or the like. Hereinafter, when the terms "radius" and "diameter" are used in this specification, they respectively include "half the area-equivalent circle diameter" and "area-equivalent circle diameter."

[0013] The single fibers constituting at least one surface of the fiber sheet support a plurality of particles. The particles contain nitride. The nitride generates and releases ammonia upon hydrolysis. Ammonia is known to exhibit antibacterial properties against at least both gram-positive and gram-negative bacteria. Since the antibacterial fiber sheet supports nitride-containing particles on the surface of the fiber sheet, the particles can be easily brought into contact with water (hydrolyzed), thereby quickly generating and releasing ammonia. In other words, the antibacterial fiber sheet can efficiently exhibit antibacterial properties. Note that the water that hydrolyzes the nitride is not limited to a liquid state, and may be in a non-liquid state such as a gas or solid.

[0014] Preferably, the single fibers that make up the other surface of the fiber sheet also carry a plurality of particles, and more preferably, the single fibers that make up the central portion of the fiber sheet in the thickness direction also carry a plurality of particles. This increases the proportion of particles in the entire antibacterial fiber sheet, thereby increasing the amount of ammonia released and improving the antibacterial properties.

[0015] Examples of nitrides include aluminum nitride (AlN), magnesium nitride (Mg3N2), calcium nitride (Ca3N2), iron nitride (Fe2N, Fe3N 1+X , Fe4N, Fe7N3, Fe 16Examples of suitable nitrides include metal nitrides such as silicon nitride (SiN), nonmetal nitrides such as silicon nitride (SiN) and carbon nitride (CN), and composite nitrides such as oxynitrides such as sialon (SiN·AlO). Among these, the nitride preferably contains at least one selected from the group consisting of silicon nitride, boron nitride, aluminum nitride, yttrium nitride, titanium nitride, zirconium nitride, gallium nitride, vanadium nitride, calcium nitride, and iron nitride. These nitrides are particularly stable in the atmosphere, making it easy to maintain the antibacterial properties of the antibacterial fiber sheet until use. In other words, these nitrides can exhibit their antibacterial properties at the desired timing. In particular, using at least one nitride selected from the group consisting of silicon nitride, boron nitride, and aluminum nitride can also reduce costs.

[0016] The proportion of particles in the entire antibacterial fiber sheet is preferably about 5% by volume or more, more preferably about 6% by volume or more, and even more preferably about 7% by volume or more. In this case, the amount of particles supported on the surface of the fiber sheet is less likely to vary, improving the reliability of the antibacterial fiber sheet's antibacterial properties. In other words, the quality of the antibacterial fiber sheet can be ensured. Furthermore, by supporting such a sufficient amount of nitride, a stable supply of ammonia from the antibacterial fiber sheet can be maintained, which means that the antibacterial fiber sheet can be expected to maintain its antibacterial properties for a long period of time.

[0017] Furthermore, the proportion of particles in the entire antibacterial fiber sheet is preferably about 50% by volume or less, more preferably about 30% by volume or less, and even more preferably about 15% by volume or less. Since the majority of the particles can come into contact with the surface of the single fibers in just the right amount, the fiber sheet can firmly support the particles. This prevents deterioration of the quality of the antibacterial fiber sheet due to particle shedding.

[0018] The proportion of particles in the entire antibacterial fiber sheet is preferably about 10% by mass to 40% by mass, more preferably about 12% by mass to 35% by mass, and even more preferably about 15% by mass to 30% by mass, which makes it easier to more reliably achieve the above-mentioned effects. The proportion (volume % and mass %) of particles in the antibacterial fiber sheet can be determined, for example, by X-ray diffraction (XRD) analysis of the antibacterial fiber sheet.

[0019] The area of ​​the region on the surface of the antibacterial fiber sheet that is composed of particles (in other words, the area of ​​the region on the surface of the fiber sheet that is covered with particles) is preferably about 5% or more, more preferably about 10% or more, about 20% or more, or about 40% or more, and may even be 100%. This allows the nitride-containing particles to be more reliably brought into contact with water. In other words, the antibacterial fiber sheet can more reliably exhibit antibacterial properties. Furthermore, the antibacterial fiber sheet can reduce variation in its properties and ensure high quality.

[0020] The area of ​​the region on the surface of the antibacterial fiber sheet that is composed of particles may be approximately 80% or less, approximately 70% or less, approximately 50% or less, or approximately 20% or less. In this case, the area of ​​the region on the surface of the antibacterial fiber sheet where the monofilaments are exposed increases. In other words, the thermoplastic resin contained in the outer layer of the monofilaments fills the spaces between the particles, which has the advantage of sufficiently preventing the particles from falling off the fiber sheet. The area of ​​the region composed of particles on the surface of the antibacterial fiber sheet can be obtained, for example, by elemental analysis using a scanning electron microscope (SEM)-energy dispersive X-ray spectroscopy (EDX). Elemental mapping images of 10 randomly spaced locations on the antibacterial fiber sheet are obtained, the proportion of the region where particles are mapped in each image is calculated, and the arithmetic average of the 10 images can be obtained as the area composed of particles on the surface of the antibacterial fiber sheet.

[0021] The average particle size of all particles supported on the fiber sheet is preferably about 0.01 μm to 50 μm, more preferably about 0.05 μm to 30 μm, and even more preferably about 0.1 μm to 10 μm. When the particle size is not too large, the particles are easily supported on the surface of the fiber sheet (the outer layer of the single fiber). Furthermore, when the particle size is large to a certain extent, the nitrogen content of the antibacterial fiber sheet can be ensured. In other words, the amount of ammonia eluted from the antibacterial fiber sheet can be increased, thereby improving the antibacterial properties. The average particle size may be, for example, the cumulative 50% diameter (D50) of the volume-based particle size frequency distribution.

[0022] The particle size frequency distribution based on the volume of the whole particles preferably has multiple peaks, and it is more preferable that the peak on the larger diameter side is larger among the multiple peaks. In this way, by using a large number of large diameter particles, the cost of the whole particles can be reduced while the gaps between the large diameter particles can be filled with small diameter particles. In other words, the particle loading can be increased while reducing costs, and the amount of ammonia eluted from the antibacterial fiber sheet can be increased. Furthermore, when the cumulative 10% diameter, cumulative 50% diameter, and cumulative 90% diameter of the particle size are defined as D10, D50, and D90, respectively, the value of (D90-D10) / D50 is preferably 1 or more and 2 or less, more preferably approximately 1.1 or more and 1.8 or less, and even more preferably approximately 1.15 or more and 1.6 or less. In this way, particles with different particle size distributions are mixed while maintaining a certain degree of sharpness in the particle size distribution of the entire particles. This makes it easy to ensure uniformity of particle size in the in-plane direction of the antibacterial fiber sheet, thereby reducing variation in the properties of the antibacterial fiber sheet and ensuring high quality. D10, D50, and D90 can be obtained by measuring particle size distribution by, for example, a laser diffraction / scattering method.

[0023] The particles are preferably supported so as to be embedded in the surface of the fiber sheet (the outer layer of the single fiber). In the radial direction of the single fiber, the length of the embedded portion of the particle relative to the maximum length of the particle is preferably 20% or more, preferably 50% or more, and may be 80% or more, or even 90% or more. By embedding the particles in the surface of the fiber sheet in this way, it is possible to effectively prevent the particles from falling off the fiber sheet. In other words, the adhesion of the particles to the surface of the fiber sheet is improved. The length of the part of the particle embedded in the surface of the fiber sheet can be obtained, for example, by elemental analysis using a scanning electron microscope (SEM)-energy dispersive X-ray spectroscopy (EDX). An elemental mapping image of an arbitrary part of the antibacterial fiber sheet is obtained, and the length of the part embedded in the surface of the fiber sheet for any 100 particles in the elemental mapping image is calculated, and the arithmetic average of the 100 lengths is calculated.

[0024] When 3 parts by mass of antibacterial fiber sheet and 50 parts by mass of water are mixed and left to stand for 10 minutes, the ammonia concentration in the water is preferably about 0.05 mg / L or more, more preferably about 0.1 mg / L or more, even more preferably about 0.15 mg / L or more, about 0.2 mg / L or more, about 0.25 mg / L or more, or about 0.3 mg / L or more, and particularly preferably about 0.35 mg / L or more, about 0.4 mg / L or more, or about 0.45 mg / L or more. Such rapid elution of ammonia makes it possible to inhibit the growth of bacteria such as gram-positive bacteria and gram-negative bacteria at an early stage.

[0025] Furthermore, when 3 parts by weight of the antibacterial fiber sheet is mixed with 50 parts by weight of water and left to stand for 360 minutes, the ammonia concentration in the water is preferably about 0.05 mg / L or more, more preferably about 0.1 mg / L or more, even more preferably about 0.15 mg / L or more, even more preferably about 0.2 mg / L or more, and particularly preferably about 0.25 mg / L or more. In this way, ammonia is retained in the water over time, and long-term antibacterial properties can be expected to be maintained. The area ratio of the antibacterial fiber sheet that is occupied by the portion that produces the above-mentioned ammonia concentration is preferably about 60% or more, more preferably about 70% or more, or about 80% or more, even more preferably about 90% or more, or about 95% or more, and particularly preferably 100%.

[0026] The antibacterial fiber sheet preferably has at least one hydrophilic functional group (hydrophilic group, polar group) on its surface, such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH), an aldehyde group (-CHO), a thiol group (-SH), a phosphate group (-HPO), or a carbonyl group (-CO). This increases the affinity of the antibacterial fiber sheet with water (i.e., improves the hydrophilicity (water wettability) of the antibacterial fiber sheet), and promotes the generation and elution of ammonia due to the hydrolysis of nitrides. In other words, it is easier to increase the ammonia concentration in water, and therefore the antibacterial fiber sheet can more reliably exhibit antibacterial properties.

[0027] At least one of the particles and the fiber sheet preferably has these hydrophilic groups, more preferably the particles or both the particles and the fiber sheet, and even more preferably both the particles and the fiber sheet. Among the hydrophilic groups, it is particularly preferable to have a hydroxy group, in which case it is possible to prevent unintended effects on the target (for example, water, a solution, a chemical solution, etc.) that exhibits antibacterial properties. When the particles have hydrophilic groups, their presence and bonding state can be identified by, for example, X-ray photoelectron spectroscopy (XPS).

[0028] It is preferable that the amount of impurities attached to the surface of the antibacterial fiber sheet is small. Examples of such impurities include organic substances such as human sebum, grease such as machine oil, dust including fiber debris, particles not supported on the fiber sheet, ceramic fragments resulting from particle breakage, and inorganic substances including inorganic salts. By keeping the amount of such impurities attached small, adverse effects on the antibacterial fiber sheet caused by the properties of the impurities can be prevented or suppressed. In particular, it is preferable that the amount of oil or organic substance attached is small, which can further improve the affinity of the antibacterial fiber sheet with water. It is preferable that impurities are not attached to the surface of the antibacterial fiber sheet as much as possible, but even if they are attached, the proportion of the area that they occupy on the surface of the antibacterial fiber sheet is preferably about 60% or less, more preferably about 50% or less, about 40% or less, about 30% or less, or about 20% or less, and even more preferably about 10% or less, or about 5% or less.

[0029] The weight of the antibacterial fiber sheet is not particularly limited, but is preferably 1 g / m 2 More than 1000g / m 2 It is preferable that the density is about 5 g / m or less. 2 More than 500g / m 2 It is more preferable that the content is about 10 g / m or less. 2 More than 150g / m 2 It is more preferable that the antibacterial fiber sheet has a basis weight of about 1000 or less. An antibacterial fiber sheet having such a basis weight can easily ensure a balance between the amount of particles carried and the porosity. The basis weight can be obtained, for example, by cutting out a 100×100 cm area from any one location on the antibacterial fiber sheet and measuring the mass of that area.

[0030] The thickness of the antibacterial fiber sheet is not particularly limited, but is preferably about 0.001 mm to 10 mm, more preferably about 0.01 mm to 5 mm, and even more preferably about 0.1 mm to 1 mm. The thickness of the antibacterial fiber sheet can be determined, for example, by obtaining images of five mutually spaced cross-sections of the antibacterial fiber sheet using a scanning electron microscope (SEM) and measuring the thickness at five locations based on the SEM images.

[0031] The mean flow pore size of the antibacterial fiber sheet can be set appropriately depending on the application, but is preferably approximately 0.1 μm or more and 1000 μm or less, more preferably approximately 1 μm or more and 500 μm or less, and even more preferably approximately 10 μm or more and 100 μm or less. The mean flow pore size of the antibacterial fiber sheet can be obtained, for example, in accordance with ASTM E1294-89:1999. The antibacterial fiber sheet as described above can be used for a variety of purposes, but is particularly suitable for use in medical filters (e.g., filters for blood treatment circuits, dialysis filters, infusion filters, etc.) that are used in contact with water-containing liquids (body fluids).

[0032] [Manufacturing method of antibacterial fiber sheet] Next, we will explain the method for producing an antibacterial fiber sheet. The method includes a first step of preparing a fiber sheet containing a thermoplastic resin on at least the surface and nitride-containing particles, and a second step of bringing the heated particles into contact with the fiber sheet to support the particles on the surface of the fiber sheet, thereby obtaining an antibacterial fiber sheet.

[0033] (First step) In the first step, a fiber sheet and particles are prepared. The fiber sheet and particles may be prepared by purchasing them commercially, or may be prepared by the user. In the latter case, for example, particles having different particle sizes can be mixed to prepare particles having the above-mentioned particle size distribution as a whole. Here, the particles having different particle sizes can be prepared by purchasing commercially available products, or can be prepared by physical methods such as milling, gas condensation, electrospraying, and atomization, or chemical methods such as microemulsion, hydrothermal synthesis, and pyrolysis.

[0034] When preparing a fiber sheet, first, monofilaments are prepared. Monofilaments may be prepared by purchasing commercially available products, or may be prepared using a spinning method such as wet spinning, dry spinning, melt spinning, gel spinning, liquid crystal spinning, or electrospinning. Then, using the monofilaments, a web can be formed by a method such as a dry method, wet method, spunbonding, meltblown method, or airlaid method. The formed web can then be bonded by a method such as a chemical bonding method such as a dipping method or a spray method, a thermal bonding method, a needle punch method, or a hydroentanglement method, to prepare a fiber sheet.

[0035] The weight of the fiber sheet is not particularly limited, but is preferably 1 g / m 2 More than 1000g / m 2 It is preferable that the density is about 5 g / m or less. 2 More than 500g / m 2 It is more preferable that the content is about 10 g / m or less. 2 More than 150g / m 2 It is more preferable that the temperature is about the same or less. The thickness of the fiber sheet is not particularly limited, but is preferably about 0.001 mm to 10 mm, more preferably about 0.01 mm to 5 mm, and even more preferably about 0.1 mm to 1 mm.

[0036] The mean flow pore size of the fiber sheet can be set appropriately depending on the application, but is preferably approximately 0.1 μm or more and 1000 μm or less, more preferably approximately 1 μm or more and 500 μm or less, and even more preferably approximately 10 μm or more and 100 μm or less. If the fiber sheet has such a mean flow pore size, in the subsequent second step, heated particles can easily reach the surfaces of the single fibers located in the center of the fiber sheet in the thickness direction, thereby increasing the amount of particles supported on the fiber sheet.

[0037] (Second step) In the second step, heated particles are brought into contact with the surface of the fiber sheet. The particles are heated so that when they contact the outer layer of the monofilaments that make up the fiber sheet, their temperature is equal to or higher than the melting point of the thermoplastic resin contained in the outer layer. This allows the thermoplastic resin in the outer layer to melt upon contact with the particles. The molten thermoplastic resin then cools and solidifies again, allowing the particles to be fixed and supported on the outer layer. In other words, the particles are fused to the surface of the fiber sheet.

[0038] The particles are preferably heated to a temperature higher than the melting point of the thermoplastic resin of the outer layer. In this case, the difference between the heating temperature of the particles and the melting point is preferably about 5°C to 100°C, more preferably about 10°C to 80°C, and even more preferably about 15°C to 50°C. By sufficiently heating the particles in this way, the thermoplastic resin of the outer layer in contact with the particles can be heated and reliably melted. In addition, by not overheating the particles, the molten thermoplastic resin in the outer layer can be cooled and solidified quickly, allowing the particles to be more reliably supported on the fiber sheet. Furthermore, it is possible to prevent the fiber sheet from melting more than necessary, which would cause the shape of the fiber sheet and the single fibers to be distorted. In other words, it is possible to reliably fuse the particles to the surface of the fiber sheet while reducing damage to the fiber sheet.

[0039] It is preferable that the outer layer contains the thermoplastic resin in the proportions described above for the outer layer of the single fiber, because the thermoplastic resin can fusion-bond (support) the particles so as to encase them, thereby improving the adhesion of the particles to the surface of the fiber sheet. When the inner layer contains a thermoplastic resin, the thermoplastic resin preferably has a higher melting point than the thermoplastic resin contained in the outer layer, which allows the inner layer to remain solid while the thermoplastic resin of the outer layer is melted in the second step.

[0040] The method for contacting the particles with the fiber sheet (contact method) is not particularly limited, but examples include a method in which an air current such as an aerosol containing particles is blown onto the fiber sheet. Examples of carrier gases that can be used to transport the particles include air, reducing gases such as nitrogen, and inert gases such as argon and helium. Other contact methods include a method in which the particles are allowed to fall from above the fiber sheet under their own weight, and a method in which the fiber sheet and heated particles are mixed in a container by, for example, stirring, shaking, or vibrating.

[0041] The particles are preferably brought into contact with both sides of the fiber sheet. For example, the particles may be brought into contact with the fiber sheet while it is being conveyed in its longitudinal direction, and then the fiber sheet may be turned over and conveyed again in the longitudinal direction while it is being conveyed again. This reduces unevenness in the amount of particles carried, and allows for the production of an antibacterial fiber sheet with uniformity on both sides. Furthermore, in the second step, it is preferable to use the so-called roll-to-roll method. That is, it is preferable to unwind a rolled fiber sheet, bring it into contact with heated particles, and then rewind it into a roll. This can reduce manufacturing costs, especially in mass production.

[0042] The thermoplastic resin of the outer layer, which has melted upon contact with the particles, then solidifies again (the particles fuse to the surface of the fiber sheet), yielding an antibacterial fiber sheet. The method for solidifying the thermoplastic resin (solidification method) is not particularly limited, but examples include leaving the antibacterial fiber sheet at room temperature (natural cooling), blowing room-temperature or cold air onto the antibacterial fiber sheet using a fan (cooling by blowing), and leaving the antibacterial fiber sheet in a low-temperature environment such as a low-temperature room or refrigerator (forced cooling). Among these, blowing cooling is particularly preferred as the solidification method, as it allows the thermoplastic resin to be rapidly solidified while blowing away excess particles that are not fused to the thermoplastic resin (fiber sheet).

[0043] Furthermore, the method for producing an antibacterial fiber sheet preferably further comprises a step of subjecting the antibacterial fiber sheet to a surface treatment such as corona discharge treatment, flame treatment, or plasma treatment after the antibacterial fiber sheet is obtained, thereby improving the desired properties of the antibacterial fiber sheet, such as its antibacterial properties and texture. As the surface treatment, plasma treatment such as atmospheric pressure plasma treatment or vacuum plasma treatment is preferred. Such plasma treatment can avoid exposing the antibacterial fiber sheet to high temperatures, thereby preventing particles from falling off from the fiber sheet due to re-melting of the thermoplastic resin in the outer layer. Furthermore, the high precision and uniformity of the surface treatment can more reliably modify the surface of the antibacterial fiber sheet and improve the homogeneity of the antibacterial fiber sheet.

[0044] As the plasma treatment, vacuum plasma treatment is more preferable. Vacuum plasma treatment can further improve the uniformity of the surface treatment, thereby further improving the homogeneity of the antibacterial fiber sheet. In addition, since air does not enter the gaps between the single fibers of the antibacterial fiber sheet, the antibacterial fiber sheet can be effectively prevented from becoming twisted or wrinkled. In the plasma treatment, various gases can be used as the treatment gas (i.e., plasma gas), but it is preferable to use a gas containing at least one selected from the group consisting of oxygen (O2) gas (oxygen plasma), hydrogen (H2) gas (hydrogen plasma), water vapor (H2O) (water vapor plasma), nitrogen (N2) gas (nitrogen plasma), and ammonia (NH3) gas (ammonia plasma). By using these gases, hydrophilic groups can be added to the surface of the antibacterial fiber sheet, thereby increasing its hydrophilicity.

[0045] In particular, by using a gas containing nitrogen atoms (nitrogen gas, ammonia gas, etc.), it is expected that at least some of the nitrogen atoms will be attached to the surface of the antibacterial fiber sheet, thereby increasing the amount of ammonia that is eluted when the antibacterial fiber sheet comes into contact with water. Furthermore, by using gases such as oxygen gas, hydrogen gas, and water vapor, it is possible to impart highly hydrophilic groups such as hydroxyl groups and carboxyl groups to the surface of the antibacterial fiber sheet, and also to remove impurities such as oils and fats and organic substances adhering to the surface of the antibacterial fiber sheet through oxidative decomposition, thereby improving the hydrophilicity of the antibacterial fiber sheet. It may also be provided in the following forms:

[0046] (1) An antibacterial textile product comprising fibers containing a thermoplastic resin at least on the surface thereof, and particles containing nitrides carried on the surface side of the fibers.

[0047] (2) The antibacterial textile product according to (1) above, wherein the proportion of the particles in the entire antibacterial textile product is 5% by volume or more.

[0048] (3) In the antibacterial textile product described in (1) or (2) above, the frequency distribution of the particle size based on volume of the particles has multiple peaks, and when the cumulative 10% diameter, cumulative 50% diameter, and cumulative 90% diameter of the particle size are D10, D50, and D90, respectively, the value of (D90-D10) / D50 is 1 or more and 2 or less.

[0049] (4) An antibacterial textile product according to any one of (1) to (3) above, wherein when 3 parts by mass of the antibacterial textile product is mixed with 50 parts by mass of water and left to stand for 10 minutes, the ammonia concentration in the water is 0.05 mg / L or more.

[0050] (5) An antibacterial textile product according to any one of (1) to (4) above, wherein when 3 parts by mass of the antibacterial textile product is mixed with 50 parts by mass of water and left to stand for 360 minutes, the ammonia concentration in the water is 0.05 mg / L or more.

[0051] (6) The antibacterial textile product according to any one of (1) to (5) above, wherein the nitride comprises at least one selected from the group consisting of silicon nitride, boron nitride, aluminum nitride, yttrium nitride, titanium nitride, zirconium nitride, gallium nitride, vanadium nitride, calcium nitride, and iron nitride.

[0052] (7) The antibacterial fiber product according to any one of (1) to (6) above, wherein the fiber is a fiber sheet.

[0053] (8) A method for producing an antibacterial textile product, comprising the steps of: preparing fibers containing a thermoplastic resin at least on the surface thereof; and particles containing nitrides; and bringing the particles in a heated state into contact with the fibers, thereby supporting the particles on the surface of the fibers, thereby obtaining the antibacterial textile product.

[0054] (9) The method for producing an antibacterial textile product according to (8) above, further comprising a step of subjecting the antibacterial textile product to a plasma treatment after obtaining the antibacterial textile product.

[0055] (10) The method for producing an antibacterial textile product according to (9) above, wherein oxygen gas is used as the treatment gas in the plasma treatment.

[0056] (11) The method for producing an antibacterial textile product according to (9) or (10) above, wherein the plasma treatment is a vacuum plasma treatment. Of course, this is not the case.

[0057] Finally, while various embodiments of the present disclosure have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the claims. For example, the single fiber does not have to be composed of two layers, an inner layer and an outer layer, as long as it has a thermosetting resin on the surface. The single fiber may be composed of, for example, only one layer or three or more layers. Furthermore, the antibacterial textile product may be in the form of fibers rather than sheets. That is, the antibacterial textile product may be an antibacterial fiber. In this case, the fiber carrying the nitride-containing particles may preferably have the monofilament structure described above. Then, since the second step of carrying particles on a single fiber is performed, it is expected that the proportion of particles contained in the final product can be improved by using such an antibacterial fiber to produce the final product, such as an antibacterial fiber sheet.

[0058] (Example) The present invention will be described in more detail below using the following examples and comparative examples, but the present invention is not limited to the following examples.

[0059] 1. Sample Preparation (Sample No. 1: Example) First step As a single fiber, a composite fiber having an outer layer made of polyethylene resin (melting point 132°C) and an inner layer made of polypropylene resin, an average diameter of 10.5 μm, and a fiber length of 100 mm was prepared. Using this single fiber, a web was produced using a papermaking device. A thermal bonding treatment was performed on this papermaking sheet at 140°C in an air-through dryer, to produce a roll of a fiber sheet. The basis weight of this fiber sheet was 51 g / m 3 The thickness was 0.36 mm and the mean flow pore size was 35 μm. Silicon nitride particles (SN-9FWS, manufactured by Denka Co., Ltd.) were prepared as particles.

[0060] Second process In the spraying device, the particles were heated to 220°C and mixed with air heated to 167°C to form a mixed air stream. 3 It contained particles of The mixed airflow was blown onto the fiber sheet while it was being unwound from the fiber sheet roll at a speed of 5 m / min. The blowing speed of the mixed airflow was 5 m / sec. Then, the particles not supported on the fiber sheet were blown off by the air (blow), which also served to cool the fiber sheet, and the fiber sheet was then wound up. The opposite side of the fiber sheet was treated in the same way and cut into a 25.7 cm x 18.2 cm rectangle to obtain a sample (antibacterial fiber sheet). The basis weight of this sample (antibacterial fiber sheet) was 65 g / m 2 , the thickness was 0.37 mm, and the mean flow pore size was 35 μm.

[0061] (Sample No. 2: Example) The sample (antibacterial fiber sheet) obtained in the same manner as Sample No. 1 was subjected to atmospheric pressure plasma treatment using a plasma irradiation device (DP series, manufactured by SDI Corporation). The plasma generation method was the dielectric barrier discharge method, the treatment gas was nitrogen, the gas flow rate was 80 L / min, the treatment time was 0.08 min, and the discharge power density was 20 W min / m. 2 The plasma treatment was performed on both sides of the sample (antibacterial fiber sheet) with the electrode-substrate (sample) distance set at 2 mm.

[0062] (Sample No. 3: Example) The sample (antibacterial fiber sheet) obtained in the same manner as Sample No. 1 was subjected to vacuum plasma treatment using a plasma irradiation device (Pink, V6-G). The plasma was generated by microwave discharge, with oxygen as the treatment gas, a gas flow rate of 0.1 L / min, a treatment time of 0.5 min, and a discharge power density of 50 W min / m. 2 The treatment was carried out on both sides of the sample (antibacterial fiber sheet) under the conditions of a vacuum degree of 20 Pa and a distance between the electrode and the substrate (sample) of 2 mm. (Sample No. 4: Comparative Example) The fiber sheet prepared in the first step of Sample No. 1 was used as the sample as it was.

[0063] 2. Measurement and testing [Particle size distribution measurement] The particle size distribution of the particles prepared in the first step on a volume basis was measured using a laser diffraction / scattering particle size distribution measuring device (MRB Sync, manufactured by Microtrack Bell). [Scanning electron microscope observation] The cross sections of Samples No. 1 to 3 were observed using a scanning electron microscope (SEM) (FE-7001F, manufactured by JEOL Ltd.). [Appearance evaluation] The appearance of Samples Nos. 1 to 4 was evaluated visually.

[0064] [Ammonia elution amount measurement] The amount of ammonia elution was measured for the particles prepared in the first step and each of Samples No. 1 to 4 according to the following procedure. Specifically, 1.8 g of sample (or particles) and 30 mL of distilled water were placed in each of three 50 mL sterilized vials, mixed for 30 seconds, and then capped. Two vials were left to stand for 10 minutes and 360 minutes, respectively. The contents of the vials were filtered using filter paper with 5.0 μm openings, and the ammonia concentration of the filtrate was measured. The ammonium ion concentration and pH were also measured as reference values.

[0065] The ammonia concentration and ammonium ion concentration were measured using an ion chromatograph analyzer (ICS-2100, manufactured by Thermo Fisher Scientific). The pH was measured using a pH meter (Mettler-Toledo, FP20-Std-Kit). In addition, since neither ammonia nor ammonium ions were detected in sample No. 4, subsequent tests were omitted.

[0066] [Antibacterial activity test] The antibacterial activity of samples No. 1 to 3 against Staphylococcus aureus and Escherichia coli was tested in accordance with JIS L 1902:2015, Section 8.1 "Bacterial liquid absorption method." The incubation temperature and incubation time for the test sample and control sample were 35°C and 24 hours, respectively. The antibacterial activity value was calculated using the following formula: A=(logC t -logC0)-(logT t -logT0) where A is the antibacterial activity value, (logC t -logC0) is the growth value of the control sample, (logT t -logT0) indicates the proliferation value of the test sample.

[0067] 3.Results [Particle size distribution measurement results] Figure 1 is a graph showing the measurement results of particle size distribution. As shown in Figure 1, the volume-based particle size frequency distribution had two peaks. The particle size for each cumulative volume is shown in Table 1 below.

[0068] [Table 1]

[0069] [Scanning electron microscope observation results] FIG. 2 shows a scanning electron microscope image of the cross section of Sample No. 1. FIG. 3 shows a scanning electron microscope image of the cross section of Sample No. 2. FIG. 4 shows a scanning electron microscope image of the cross section of Sample No. 3. The lower images in FIGS. 2 to 4 are enlarged images of the area surrounded by the dashed line in the upper image. As shown in FIGS. 2 to 4, it was confirmed that particles were supported on the surface of the fiber sheet (single fiber) in all of Examples 1 to 3.

[0070] Other measurement and test results are shown in Table 3 below. In addition, "SA" in the antibacterial activity values ​​indicates Staphylococcus aureus (S. aureus), and "EC" indicates Escherichia coli (E. coli).

[0071] [Table 2]

Claims

1. An antibacterial textile product, Fibers containing a thermoplastic resin at least on the surface thereof; Particles containing nitride are supported on the surface side of the fiber. Antibacterial textile products.

2. The antibacterial textile product according to claim 1, The proportion of the particles in the entire antibacterial textile product is 5% by volume or more. Antibacterial textile products.

3. The antibacterial textile product according to claim 1, The particle size frequency distribution based on the volume of the particles has multiple peaks, When the cumulative 10% diameter, cumulative 50% diameter, and cumulative 90% diameter of the particle size are defined as D10, D50, and D90, respectively, the value of (D90-D10) / D50 is 1 or more and 2 or less. Antibacterial textile products.

4. The antibacterial textile product according to claim 1, When 3 parts by mass of the antibacterial textile product and 50 parts by mass of water are mixed and left to stand for 10 minutes, the ammonia concentration in the water is 0.05 mg / L or more. Antibacterial textile products.

5. The antibacterial textile product according to claim 1, When 3 parts by mass of the antibacterial textile product and 50 parts by mass of water are mixed and left to stand for 360 minutes, the ammonia concentration in the water is 0.05 mg / L or more. Antibacterial textile products.

6. The antibacterial textile product according to claim 1, The nitride includes at least one selected from the group consisting of silicon nitride, boron nitride, aluminum nitride, yttrium nitride, titanium nitride, zirconium nitride, gallium nitride, vanadium nitride, calcium nitride, and iron nitride. Antibacterial textile products.

7. The antibacterial textile product according to claim 1, The fiber is a fiber sheet. Antibacterial textile products.

8. A method for producing an antibacterial textile product, comprising: providing fibers containing a thermoplastic resin on at least the surface thereof and particles containing a nitride; and bringing the particles in a heated state into contact with the fibers to support the particles on the surfaces of the fibers, thereby obtaining the antibacterial textile product. A method for manufacturing antibacterial textile products.

9. The method for producing an antibacterial textile product according to claim 8, The method further comprises a step of subjecting the antibacterial textile product to a plasma treatment after obtaining the antibacterial textile product. A method for manufacturing antibacterial textile products.

10. The method for producing an antibacterial textile product according to claim 9, In the plasma treatment, oxygen gas is used as a treatment gas. A method for manufacturing antibacterial textile products.

11. The method for producing an antibacterial textile product according to claim 9, The plasma treatment is a vacuum plasma treatment. A method for manufacturing antibacterial textile products.

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