JP2025176587A - Manufacturing method for antibacterial and antifungal fiber structure, antibacterial and antifungal fiber structure - Google Patents

Abstract

[Problem] To provide a method for producing an antibacterial and antifungal fiber structure with excellent washing durability, which prevents deterioration of the fiber's breathability and feel, prevents the harmful effects of formalin release on the environment and the human body, and prevents a decrease in the fiber structure's strength by directly fixing the antibacterial and antifungal component to the fiber structure, and the antibacterial and antifungal fiber structure obtained thereby. [Solution] The method for producing an antibacterial and antifungal fiber structure includes a processing solution preparation step of preparing a processing solution (6) containing the antibacterial and antifungal composition but not containing a film-forming compound, and a processing solution heating step of applying the processing solution (6) to a fiber structure (2) and heating it at 100 to 230°C under normal or increased pressure for 0.5 minutes or more, in which the antibacterial and antifungal composition contains a metal oxide (A), the fiber structure (2) contains synthetic fibers, and the antibacterial and antifungal component is directly fixed to the fiber structure (2) in a proportion of 0.02 parts by mass or more per 100 parts by mass of the fiber structure (2). [Selected Figure] Figure 1

Description

The present invention relates to a method for producing an antibacterial and antifungal fiber structure, and to an antibacterial and antifungal fiber structure.
More specifically, the present invention relates to a method for producing an antibacterial and antifungal fiber structure in which the antibacterial and antifungal component is directly fixed to the surface of the fiber structure without using a film-forming compound (so-called resin binder), thereby enabling sufficient antibacterial and antifungal properties to be exhibited with only a small amount of the antibacterial and antifungal component, without significantly impairing the texture of the fiber structure, and to the antibacterial and antifungal fiber structure obtained thereby.

In recent years, it has been proposed to directly add antibacterial and antifungal components to various household products, including clothing, and industrial materials, thereby imparting antibacterial and antifungal properties to the products themselves.
However, simply applying antibacterial or other chemicals to a product itself easily removes the chemicals through washing, and therefore various methods for sustaining the antibacterial and antifungal effects of textile products are being studied.
As such a method, for example, a method has been proposed in which a polymer emulsion film-forming compound is used together with the antibacterial/antifungal compound to form a resin film on the surface of fibers or between fibers, thereby immobilizing the antibacterial/antifungal compound (see Patent Document 1).
Furthermore, in order to prevent the antibacterial/antifungal compound from leaching out from the substrate to which it is attached (plastic, cloth, fiber, etc.), an antibacterial/antifungal agent in the form of an immobilized antibacterial/metal complex has been proposed (see Patent Document 2).
Furthermore, a coating agent using a binder to provide heat-retaining, antibacterial, deodorizing, and deodorizing properties, and processed fibers with heat-retaining, antibacterial, deodorizing, and deodorizing properties have been proposed (see Patent Document 3).

Special Publication No. 2009-538319 Patent Application No. 2009-512015 Japanese Patent Application No. 07-41082

However, in the method of using a film-forming compound such as a polymer emulsion as a binder and attaching and fixing the antibacterial and antifungal compound to the fiber by a resin coating, the formation of the resin coating reduces the breathability and feel of the fiber, and furthermore, often causes discoloration, making it unsuitable for clothing and interior applications.
Furthermore, the resin coating falls off due to friction and the like, and the antibacterial and antifungal properties decrease, so there is also the problem that the performance does not last for a long period of time.
Furthermore, there is a problem in that the film-forming compounds used for forming the film (for example, melamine-based compounds and glyoxal-based compounds) release formalin, which may have adverse effects on the environment and the human body.
On the other hand, when raw materials containing antibacterial agents are kneaded and spun into fibers, the antibacterial and antifungal properties are more durable to washing, but the antibacterial and antifungal agents are contained in the interior, which does not contribute to the effects, resulting in a large amount of antibacterial and antifungal agent, which increases costs.Furthermore, there is a problem in that the strength of the obtained fiber structure tends to decrease because the strength of the yarn is reduced by chemicals such as antibacterial agents.

Against this background, the present invention aims to provide a method for producing an antibacterial and antifungal fiber structure with excellent washing durability, which prevents deterioration of the fiber's breathability and feel, suppresses discoloration, and prevents the harmful effects of formalin release on the environment and human body by fixing the antibacterial and antifungal component directly to the fiber structure, rather than fixing the antibacterial and antifungal component to the fiber structure using a resin coating or incorporating the component into the spinning raw material, and the antibacterial and antifungal fiber structure obtained thereby.

Therefore, the present inventors have conducted extensive research to develop a method for imparting antibacterial and antifungal properties that are water-resistant and wash-resistant to resin molded articles used in various industrial materials and household goods (including clothing).
As a result, it was discovered that by preparing a processing liquid by dissolving or dispersing a metal oxide (A), which has conventionally been known as an antibacterial and antifungal agent, in a solvent such as water at a predetermined concentration, and then contacting the processing liquid with a fiber structure and subjecting it to a heat treatment for a predetermined period of time, the metal oxide (A) can be fixed directly to the surface of the fiber structure without the need to take the trouble of forming a resin coating using a film-forming compound.
The present inventors have also found that the metal oxide (A) immobilized on a fiber structure exhibits excellent antibacterial and antifungal properties, and therefore can impart antibacterial and antifungal properties with excellent water resistance and washing durability to various fiber structures, thereby completing the present invention.

That is, the present invention has the following aspects.
[1] A method for producing an antibacterial and antifungal fiber structure in which a metal oxide (A) contained in an antibacterial and antifungal composition is directly fixed to the surface of the fiber structure, the method comprising: a processing liquid preparation step of preparing a processing liquid containing the antibacterial and antifungal composition but not containing a film-forming compound; and a processing liquid heat treatment step of applying the processing liquid to the fiber structure and heating the processing liquid at 100 to 230°C under normal pressure or pressure for 0.5 minutes or more, in which the metal oxide (A) is directly fixed in an amount of 0.02 parts by mass or more per 100 parts by mass of the fiber structure.
[2] The method for producing an antibacterial and antifungal fiber structure according to [1], wherein the metal oxide (A) contained in the antibacterial and antifungal composition is spot-fixed to the surface of the fiber structure.
[3] The method for producing an antibacterial and antifungal fiber structure according to [1] or [2], wherein the metal oxide (A) contained in the antibacterial and antifungal composition is at least one compound selected from the group consisting of zinc oxide, titanium oxide, silver oxide, and copper oxide.
[4] The method for producing an antibacterial and antifungal fiber structure according to [1] or [2], wherein the antibacterial and antifungal composition further contains an isothiazolinone compound (B).
[5] The method for producing an antibacterial and antifungal fiber structure according to [4], wherein the isothiazolin-based compound (B) contained in the antibacterial and antifungal composition is at least one compound selected from the group consisting of 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 4-chloro-2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one.
[6] The method for producing an antibacterial and antifungal fiber structure according to [4] or [5], wherein the mass ratio (B/A) of the isothiazolinone compound (B) to the metal oxide (A) in the antibacterial and antifungal composition is set to 0.01 to 0.25.
[7] The method for producing an antibacterial and antifungal fiber structure according to any one of [1] to [6], wherein the metal oxide (A) is composed of particles having a particle diameter of 100 to 400 nm in an amount of 50 mass % or more.
[8] The method for producing an antibacterial and antifungal fiber structure according to any one of [1] to [7], wherein the film-forming compound is at least one selected from the group consisting of acrylic compounds, urethane compounds, silicone compounds, epoxy compounds, polyester compounds, and melamine compounds.
[9] The method for producing an antibacterial and antifungal fiber structure according to any one of [1] to [8], wherein the processing liquid contains phosphoric acid and/or citric acid.
[10] The method for producing an antibacterial and antifungal fiber structure according to any one of [1] to [9], wherein the pH of the processing solution is in the range of 3 to 6.
[11] An antibacterial and antifungal fiber structure in which a metal oxide (A) is directly fixed at a ratio of 0.02 parts by mass or more per 100 parts by mass of the fiber structure, and the antibacterial and antifungal fiber structure has an antibacterial activity value of 2.0 or more and an antifungal activity value of 1 or more.
[12] The antibacterial and antifungal fiber structure according to [11], wherein the fiber structure comprises synthetic fibers.
[13] The antibacterial and antifungal fiber structure according to [11] or [12], which has an antibacterial activity value of 2.0 or more and an antifungal activity value of 1 or more after 10 washes according to the standard washing method (washing method for SEK-marked fiber products).
[14] The antibacterial and antifungal fiber structure according to any one of [11] to [13], which has an antibacterial activity value of 2.0 or more and an antifungal activity value of 1 or more after 50 washes using a high-temperature accelerated washing method (a washing method for SEK-marked fiber products).
[15] The antibacterial and antifungal fiber structure according to any one of [11] to [14], which has a deodorizing rate of 50% or more for at least one odor of ammonia, acetic acid, or isovaleric acid after 10 washes using a standard washing method (washing method for SEK-marked fiber products).
[16] The antibacterial and antifungal fiber structure according to any one of [11] to [15], wherein the isothiazolinone compound (B) is directly fixed to a fiber structure having synthetic fibers, and the ratio of the isothiazolinone compound (B) to 1 part by mass of the metal oxide (A) is set to 0.01 to 0.25 parts by mass.
[17] The antibacterial and antifungal fiber structure according to any one of [11] to [16], wherein the metal oxide (A) is composed of particles having a particle diameter of 100 to 400 nm in an amount of 50 mass % or more.

The method for producing an antibacterial and antifungal fiber structure of the present invention can fix the antibacterial and antifungal component directly to the fiber structure without fixing the antibacterial and antifungal component to the fiber structure using a resin coating or incorporating the antibacterial and antifungal component into the spinning raw material, thereby preventing the fiber structure from becoming less breathable or less comfortable to the touch, reducing the risk of discoloration, and preventing the film-forming compound used to form the resin coating from having adverse effects on the environment and human body, making it possible to produce an antibacterial and antifungal fiber structure with excellent washing durability.
Furthermore, the antibacterial and antifungal fiber structure of the present invention exhibits antibacterial and antifungal properties, as well as deodorizing properties, and these deodorizing, antibacterial and antifungal properties are water-resistant and wash-resistant, and are therefore long-lasting.
Furthermore, since the antibacterial and antifungal fiber structure can be repeatedly washed, wiped with water, and laundered without losing its deodorizing, antibacterial, and antifungal properties, it has the advantage of being able to keep the antibacterial and antifungal fiber structure clean for a long period of time.

FIG. 1(a) is a diagram for explaining the manufacturing process of this embodiment, and FIG. 1(b) is a diagram for explaining another manufacturing process of this embodiment. FIG. 2(a) is a view of the surface of the fiber structure used in this embodiment, observed with an electron microscope, and FIG. 2(b) is a view showing the detection of zinc present on the surface. FIG. 3(a) is a view of the surface of the fiber structure of this embodiment observed with an electron microscope, and FIG. 3(b) is a view showing the detection of zinc present on the surface. FIG. 4(a) is a view of the surface of a conventional fiber structure observed with an electron microscope, and FIG. 4(b) is a view showing the detection of zinc present on the surface. FIG. 2 is a graph showing a comparison of XRD diffraction of the antibacterial and antifungal component of the present embodiment and zinc oxide.

The present invention will be described below based on examples of embodiments for carrying out the present invention. However, the present invention is not limited to the embodiments described below.

In this specification, "x and/or y (x and y are optional configurations)" means at least one of x and y, and can mean three possibilities: x only, y only, or x and y.
In this specification, when an expression "X to Y" (X and Y are any numbers) is used, it means "X or more and Y or less" and also means "preferably larger than X" or "preferably smaller than Y" unless otherwise specified.
In this specification, when it is expressed as "X or more" (X is any number) or "Y or less" (Y is any number), it also means that "it is preferably greater than X" or "it is preferably less than Y".
In the present specification, when numerical ranges are described in stages, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values shown in the examples.

The manufacturing method for the antibacterial and antifungal fiber structure of this embodiment, and the antibacterial and antifungal fiber structure itself, are described in detail below.

(Fiber structure)
In this embodiment, the fiber structure to be imparted with antibacterial and antifungal properties is the fiber itself or a product made from such a fiber. The fiber structure prepared before imparting the antibacterial and antifungal properties may be in the form of the final product as is, or the fiber structure may be modified or combined with other components to change its shape or configuration to form the final product.

Such fiber structures can be in various forms, including spun, knitted, woven, and nonwoven. Specific products include various types of clothing, socks, tights, sportswear, outdoor products, bedding, rugs, curtains, indoor cloths, and sanitary products such as bandages, gauze, and masks. In particular, the fiber structure of the present invention is suitable for use in sportswear, clothing, socks, tights, outdoor products, and bedding, because it feels pleasant to the touch, has excellent antibacterial and antifungal properties, is durable to washing, and poses no adverse effects on the environment or the human body.

The fiber structure used in this embodiment uses natural fibers, synthetic fibers, and blends thereof as constituent fibers. Examples of natural fibers include cotton, linen, silk, and wool. Of these, cotton is preferably used. Examples of synthetic fibers include polyester resins, polyamide resins, acrylic resins, and polyurethane resins. Of these, polyethylene terephthalate, nylon, and acrylic are preferably used in terms of durability and weather resistance.
The synthetic fibers also include semi-synthetic fibers such as cellulose resins and acetate resins, as well as composites and mixtures thereof.

The fiber structure used in this embodiment may be a mixture of natural or synthetic fibers with components other than synthetic fibers (such as metals or inorganic substances), or a blend of synthetic fibers with natural fibers such as cotton, acetate, rayon, wool, or silk.
When the fiber structure of this embodiment contains fibers other than synthetic fibers, from the standpoint of durability and weather resistance, it is preferable that the fibers account for 50 mass% or less of the total mass of the fiber structure, more preferably 30 mass% or less, and even more preferably 20 mass% or less.

(Antibacterial and antifungal composition)
The antibacterial and antifungal composition used in this embodiment contains a metal oxide (A), and preferably contains an isothiazolinone compound (B).

Examples of the metal oxide (A) include zinc oxide, titanium oxide, silver oxide, and copper oxide. Of these, zinc oxide is preferred.

Examples of the isothiazoline compound (B) include 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 4-chloro-2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one. Of these, 1,2-benzisothiazolin-3-one is preferred.

The metal oxide (A) is preferably one that is composed of particles having a particle size of 100 to 400 nm in an amount of 50% by mass or more, in view of excellent dispersibility.
The particle size of the metal oxide (A) can also be calculated as a value determined as the median diameter corresponding to a cumulative 50% in a particle size distribution measured using a laser diffraction particle size distribution analyzer in accordance with JIS R1629.

Furthermore, when an isothiazolinone compound (B) is used as the antibacterial and antifungal component, from the standpoint of safety, the mass ratio (B/A) of the isothiazolinone compound (B) to the metal oxide (A) is preferably set to 0.01 to 0.25, more preferably 0.01 to 0.1, and even more preferably 0.01 to 0.05.

(processing fluid)
The machining fluid used in this embodiment contains the antibacterial and antifungal composition but does not contain a film-forming compound.
That is, the processing fluid is obtained by diluting the antibacterial and antifungal composition to a predetermined concentration with an aqueous solvent (water or water to which a water-soluble organic solvent such as ethanol, n-propanol, or ethylene glycol has been added), and water is preferably used as the aqueous solvent.
The film-forming compound is a compound used to fix various components by forming a resin film on the surface of a fiber structure or between fibers. Examples of such film-forming compounds include acrylic compounds, urethane compounds, silicone compounds, epoxy compounds, polyester compounds, and melamine compounds.
In this embodiment, "not containing a film-forming compound" includes not only a case where no film-forming compound is contained at all, but also a case where a film-forming compound is contained in such a small amount that it is not capable of exhibiting its properties.

The content of the antibacterial and antifungal composition in the processing liquid is set taking into consideration the mass of the fiber structure to be treated and the mass of the antibacterial and antifungal component contained in the antibacterial and antifungal composition. Typically, the processing liquid preferably contains 0.01 to 5 mass% of the antibacterial and antifungal composition, more preferably 0.02 to 2 mass%, and even more preferably 0.04 to 1 mass%. Setting the content within this range has the advantage of making it easier to set the concentration of the antibacterial and antifungal component in the processing liquid to any desired range.

Furthermore, the processing liquid may contain functional components other than the antibacterial and antifungal composition, and among these, it is more preferable that the processing liquid contain an organic acid such as phosphoric acid or citric acid from the viewpoint of deodorizing and antibacterial properties.
The pH of the processing liquid is preferably 3 to 6, and more preferably 4 to 5, from the viewpoint of improving the fixing rate of the antibacterial and antifungal components to the fiber structure.

In addition to the above, the processing solution may contain various additives as needed, such as swelling agents, penetrating agents, emulsifying/dispersing agents, sequestering agents, leveling agents, softeners, suspending agents, migration inhibitors, carriers, dye-resistant agents, wrinkle-resistant agents, and texture-improving agents.

Furthermore, depending on the types of auxiliary agents and additives used and the material of the target fiber structure, water-soluble organic solvents such as ethanol, n-propanol, and ethylene glycol can be used in addition to or instead of water in the processing liquid. In some cases, non-aqueous solvents can also be used.

(Process for producing machining fluid)
As shown in FIG. 1( a), for example, the processing liquid 6 containing a predetermined amount of antibacterial and antifungal components can be prepared by placing an aqueous solvent in a treatment tank 1, adding the antibacterial and antifungal composition to the water, and optionally adding other components.
That is, the aqueous solvent that is the base of the processing fluid is usually water, and if necessary, a small amount of a solvent or a water-soluble substance may be mixed with the water.

(Processing liquid heating treatment process)
The method for applying the processing liquid to the fiber structure and the method for heating the same can be appropriately selected depending on the material of the fiber structure to be processed.
For example, as shown in FIG. 1(a), a method can be used in which the fiber structure 2 is immersed in a processing liquid 6 and then heat-treated in this state at a predetermined temperature and under a predetermined pressure.
That is, the fiber structure 2 is immersed in the processing liquid 6 in the treatment tank 1 , and then passed through squeeze rolls 3 to be pulled up while being lightly squeezed, and then introduced into a heating device 4 .
The fiber structure 2 to which a predetermined amount of the processing liquid 6 has been attached is moved within the heating device 4 and subjected to a heat treatment (so-called "pad-dry processing") at a predetermined temperature (140 to 230°C) for a predetermined time (0.5 minutes or more), and can be dried by passing through a dryer 5 as needed.

As another method, for example, as shown in FIG. 1(b), a method in which the fiber structure 2 is immersed in a processing liquid 6 and then heat-treated in that state at a predetermined temperature and under a predetermined pressure can be mentioned.
That is, the fiber structure 2 is immersed in the processing liquid 6 in this processing tank 1, and then heated under sealed conditions, and subjected to a heat treatment (so-called "exhaustion processing") at a predetermined temperature (100 to 140°C) for a predetermined time (20 minutes or more) under pressure, and then dried as necessary.

To fix a predetermined amount of antibacterial and antifungal component to the fiber structure, the concentration of the antibacterial and antifungal component in the processing liquid and the amount of the processing liquid applied relative to the amount of the target fiber structure material can be set.
For example, to directly fix the antibacterial and antifungal component at a ratio of 0.02 parts by mass per 100 parts by mass of the fiber structure, 100 parts by mass of a processing liquid containing 0.02 parts by mass of the antibacterial and antifungal component can be applied to 100 parts by mass of the fiber structure (100% squeezing).

On the other hand, if the density of the fiber structure is high, applying a large amount of liquid may result in the fiber structure becoming too heavy and unable to be squeezed sufficiently. Therefore, in such cases, it is preferable to apply a small amount of liquid (increase the amount of antibacterial and antifungal components contained in the liquid) and set the amount of antibacterial and antifungal components fixed to the fiber structure.

Another method for applying the processing liquid to a fiber structure is to apply the processing liquid to the fiber structure under normal pressure by immersion (impregnation), spraying, coating, etc., and then squeezing it to a predetermined squeezing ratio using a mangle or centrifuge, etc.

The antibacterial and antifungal fiber structure of this embodiment obtained in this manner is configured so that the antibacterial and antifungal component is adhered at a ratio of 0.02 parts by mass or more, preferably 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass per 100 parts by mass of the fiber structure.

The heat treatment with the processing solution applied to the fiber structure is carried out under normal pressure or pressure at a temperature of 140 to 230°C, preferably 140 to 180°C, and more preferably 140 to 160°C.
If the heat treatment temperature is too low, the fiber structure will not be heated sufficiently, and the components will tend to be insufficiently fixed, whereas if the heat treatment temperature is too high, the fiber structure will tend to be damaged.
The heat treatment time is 0.5 minutes or more, preferably 0.5 to 10 minutes, and more preferably 0.5 to 3 minutes.
If the heat treatment time is too short, the fiber structure will not be heated sufficiently, and the components will tend to be insufficiently fixed, whereas if the heat treatment time is too long, the fiber structure will tend to be damaged.

(Antibacterial and antifungal fiber structures)
The antibacterial and antifungal fiber structure of this embodiment has antibacterial and antifungal components directly fixed to it at a ratio of 0.02 mass parts or more per 100 mass parts of a fiber structure containing synthetic fibers, but in reality it is difficult to determine the amount of the antibacterial and antifungal components fixed from the antibacterial and antifungal fiber structure alone.
Therefore, in this embodiment, a processing liquid containing a predetermined amount of the antibacterial and antifungal component is applied to the fiber structure in a predetermined amount, and then a heat treatment is performed under predetermined conditions, whereby a predetermined amount of the antibacterial and antifungal component is directly fixed to the fiber structure.

Therefore, it can be said that the antibacterial and antifungal component is directly fixed to the antibacterial and antifungal fiber structure obtained by the manufacturing method of this embodiment at a ratio of 0.02 parts by mass or more per 100 parts by mass of the fiber structure.

Here, "antibacterial and antifungal components are directly fixed to a fiber structure" means that the antibacterial and antifungal components are chemically bonded to the surface of the fiber structure, and does not mean that the antibacterial and antifungal components are attached and fixed to the fiber structure by a resin coating using a film-forming compound.
Examples of the chemical bond include a covalent bond, an ionic bond, a hydrogen bond, and a coordinate bond.

The reason why the antibacterial and antifungal components are directly fixed to the fiber structure is unclear, but when the surface of the antibacterial and antifungal fiber structure of this embodiment was observed under an electron microscope, as shown in Figures 3(a) and 3(b), the fixation of the antibacterial and antifungal components was observed primarily in areas with high fiber surface area, such as areas of high fiber density where the warp and weft threads intersect in the fiber structure, and uneven areas on the surface of the fiber structure. Therefore, it is presumed that the antibacterial and antifungal components are fixed by the interaction between the charge (+) of the antibacterial and antifungal components (e.g., zinc in zinc oxide) and the charge (COO-) of the synthetic fiber (e.g., polyester).

In this embodiment, the antibacterial and antifungal component is spot-fixed to the surface of the fiber structure.
Here, "spot adhesion" refers to the antibacterial and antifungal component being unevenly adhered to the surface of the fiber structure, as shown in the electron microscope images in Figures 3(a) and 3(b). The amount of adhesion is preferably 1/30 to 1/3 of the surface area of the fiber structure. In particular, it is more preferable that zinc oxide is unevenly adhered in the form of clumps of 50 nm to 1000 nm, as shown in Figure 3(b).
In this embodiment, the antibacterial and antifungal components are firmly and spot-fixed to the surface of the fiber structure by chemical bonding, thereby improving washing durability.

Conversely, when a film-forming compound is blended into the processing fluid, the metal oxide (A) is fixed in a state where it is encapsulated in a resin coating, as shown in Figures 4(a) and 4(b). Therefore, the metal oxide (A) is spread thinly over the entire surface of the fiber structure, filling the gaps between the fibers and being fixed therein. Typically, a large area, typically more than half of the surface area of the fiber structure, is covered with a coating containing the metal oxide (A) therein.

In this way, the fact that the antibacterial and antifungal components are spot-fixed to the surface of the fiber structure can be seen by comparing the fiber structure before treatment with the fiber structure after treatment.
That is, as shown in Figures 2(a) and 2(b), nothing other than the fiber structure (antibacterial and antifungal components) is found in the fiber structure before treatment, but as shown in Figures 3(a) and 3(b), the fiber structure after treatment (the antibacterial and antifungal fiber structure of this embodiment) shows that nothing other than the fiber structure (antibacterial and antifungal components) is partially fixed (spot fixed) to its surface.
2 to 4 were observed under an electron microscope at a magnification of 1000 times.
2 to 4(a) are actual images, and FIGS. 2 to 4(b) are zinc atom mapping diagrams obtained by EDX (Energy Dispersive X-ray Spectroscopy).
The fiber structure shown in Fig. 3(a) and Fig. 3(b) is the fiber structure shown in Example 9 described below.

In this embodiment, the antibacterial and antifungal component is mainly composed of metal oxide (A). That is, Fig. 5 shows the charts obtained by XRD diffraction of the antibacterial and antifungal component shown in black in Fig. 3(b) and zinc oxide, superimposed on each other. As indicated by the downward arrows, these charts and peak shapes are almost the same, which shows that the antibacterial and antifungal component and zinc oxide are almost the same.
Furthermore, although the peak height decreases slightly even when the number of washings increases, a similar peak shape is still obtained, which indicates that the antibacterial and antifungal components are firmly fixed (spot fixed) to the surface of the fiber structure.

In this embodiment, the antibacterial and antifungal component, metal oxide (A), is directly fixed to the fiber structure in an amount of 0.02 parts by mass or more per 100 parts by mass of the fiber structure. However, from the standpoint of antibacterial properties, the amount is preferably 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass.

In addition, in this embodiment, it is preferable that the isothiazolinone compound (B) be directly fixed as the antibacterial and antifungal component in an amount of 0.0006 parts by mass or more per 100 parts by mass of the fiber structure. From the standpoint of safety, this amount is more preferably 0.0006 to 0.05 parts by mass, even more preferably 0.001 to 0.05 parts by mass, and even more preferably 0.005 to 0.05 parts by mass.

Furthermore, when an isothiazolinone compound (B) is used as an antibacterial and antifungal component, from the standpoint of safety, the mass ratio (B/A) of the isothiazolinone compound (B) directly fixed to the fiber structure to the metal oxide (A) is preferably set to 0.01 to 0.25, more preferably 0.01 to 0.1, and even more preferably 0.01 to 0.05.

The antibacterial and antifungal fiber structure of this embodiment has the antibacterial and antifungal component directly fixed to it at a ratio of 0.02 parts by mass or more per 100 parts by mass of the fiber structure, and therefore has the following antibacterial and antifungal properties.

(Deodorizing properties)
It has deodorizing properties against alkaline odors (e.g., odors caused by ammonia) and/or acidic odors (e.g., odors caused by acetic acid and isovaleric acid), and the deodorizing rate for at least one of the odors of ammonia, acetic acid, and isovaleric acid is 50% or more, and preferably 70% or more.
(Antibacterial)
The antibacterial activity value against at least one of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Bacillus cereus, Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa, which are common bacteria that cause food poisoning and infectious diseases, is 2.0 or higher.
(Antifungal)
In particular, the antifungal activity value against at least one of Aspergillus niger, Penicillium niger, Aspergillus niger, Trichophyton niger, and Candida, which are common molds that are important as pathogens causing deterioration of objects and infectious diseases, is 1 or more, and more preferably 2 or more.

The evaluation of the deodorizing properties is carried out in accordance with the performance test method for deodorizing processed textile products (ISO 17299-3 gas chromatography method) as follows.
That is, the fiber structure to be measured was cut into 50 ^cm2 to prepare a sample piece, and 5 μL of the odor component prepared for each odor was poured into a 500 mL Erlenmeyer flask containing the sample piece. After 2 hours, the flask was vigorously stirred and the odor concentration was measured using a gas chromatograph. At this time, the same procedure was performed without adding the sample piece, and the odor concentration measured was used as the blank test concentration, and the deodorizing rate (%) was calculated based on the following formula. Therefore, the higher the deodorizing rate (%), the better the deodorizing properties.
Deodorization rate (%) = (1 - (sample concentration) / (blank test concentration)) x 100

The antibacterial properties were evaluated by the following method in accordance with JIS L1902.
That is, the target bacteria were inoculated into a standard piece (a fiber structure that does not exhibit antibacterial activity) and a sample piece obtained by cutting the target fiber structure, and the viable cell count of each piece was measured after culturing at 37°C for 18 to 24 hours. The antibacterial activity value was calculated from the obtained viable cell counts according to the following formula.
Antibacterial activity value=(LogCt-LogCo)-(LogTt-LogTo)
F: Proliferation value of standard specimen = (LogCt - LogCo)
LogCo: Common logarithm of the arithmetic mean of the viable cell count on the standard specimen immediately after inoculation with the test bacteria. LogCt: Common logarithm of the arithmetic mean of the viable cell count on the standard specimen after 18 hours of incubation. LogTo: Common logarithm of the arithmetic mean of the viable cell count on the sample specimen immediately after inoculation with the test bacteria. LogTt: Common logarithm of the arithmetic mean of the viable cell count on the sample specimen after 18 hours of incubation.

The antifungal properties are evaluated by the following method in accordance with JIS L1921.
Specifically, the antifungal activity was evaluated by measuring the amount of ATP contained in the target fungi. First, a liquid medium containing spores of the target fungi was inoculated onto the obtained fiber structure and cultured at 25°C for 42 hours. The amount of ATP after culture was measured, and the value was calculated as a comparison with the similar test value (ATP amount) of an untreated fiber structure.

The antibacterial and antifungal fiber structure of this embodiment has an excellent texture because the antibacterial and antifungal components are directly fixed to the fiber structure, and it also has deodorizing, antibacterial, and antifungal properties that are durable through washing.The deodorizing, antibacterial, and antifungal properties are maintained with almost no loss even after 10 washes using the standard washing method (washing method for SEK-marked fiber products) established by the Japan Textile Evaluation Technology Council, or 50 washes using the high-temperature accelerated washing method (washing method for SEK-marked fiber products).

The washing method for SEK mark textile products is a method for confirming the washing durability of SEK mark textile products certified by the Japan Textile Evaluation Technology Council, a general incorporated association.
The standard washing method conforms to JIS L1930 (home washing test method for textile products), and the high-temperature accelerated washing method involves washing at a high temperature of 80°C, simulating repeated commercial washing.

In this embodiment, the antibacterial and antifungal components are fixed directly to the fiber structure without using a resin coating, which prevents the fiber from becoming less breathable or soft to the touch, prevents the release of formalin from having a negative impact on the environment and the human body, and prevents a decrease in the strength of the fiber structure. This makes it possible to produce an antibacterial and antifungal fiber structure with excellent washing durability without using special manufacturing equipment. Therefore, the antibacterial and antifungal fiber structure of this embodiment is suitable for use in clothing and non-clothing applications, such as clothing and bedding that come into direct contact with the skin, gloves, hats, futon coverings, curtains, and tents.

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. In the examples, "parts" and "%" are based on mass.

<Antibacterial and antifungal composition>
First, antibacterial and antifungal compositions I to IV were prepared, each containing the components shown below in the formulations shown in Table 1 below.
Metal oxide (A): zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd. (particle diameter 100 to 200 nm)
Isothiazolinone compound (B): 1,2-benzisothiazolin-3-one, manufactured by Arcsada Corporation Dispersant: Newcol (polyoxyethylene alkyl ether), manufactured by Nippon Nyukazai Co., Ltd.

<Fiber structure>
The following fiber structures were prepared as the target fibers.
Cotton: Cotton gold cloth (100% cotton), manufactured by Irozome Co., Ltd. PET: Polyester tropical (100% PET), manufactured by Irozome Co., Ltd. Nylon: Nylon 66 jersey (100% nylon), manufactured by Irozome Co., Ltd.

[Example 1]
<Antibacterial and antifungal fiber structure (0 times)>
A processing liquid containing 1 part of antibacterial and antifungal composition I and 99 parts of water was prepared, and a fiber structure (PET) was immersed in a processing liquid tank filled with the processing liquid. The fiber structure was then pulled up while being squeezed through squeeze rolls so that 100 parts by mass of the processing liquid was used for 100 parts by mass of the fiber structure (squeezing rate: 100%), and the fiber structure was heat-treated at 180°C for 1 minute while being moved inside a pin tenter (PT-2A, manufactured by Tsujii Senki Co., Ltd.), to obtain an antibacterial and antifungal fiber structure (0 times).
<Antibacterial and antifungal fiber structure (HL 5 times)>
The antibacterial and antifungal fiber structure (0 times) was washed five times at 40°C according to the standard washing method specified in the "SEK Mark Textile Product Washing Method" and then air-dried overnight to obtain an antibacterial and antifungal fiber structure (HL 5 times).
<Antibacterial and antifungal fiber structure (HL 10 times)>
The antibacterial and antifungal fiber structure (0 times) was washed 10 times at 40°C according to the standard washing method specified in the "SEK Mark Textile Product Washing Method" and then air-dried overnight to obtain an antibacterial and antifungal fiber structure (HL 10 times).
<Antibacterial and antifungal fiber structure (KL 50 times)>
The antibacterial and antifungal fiber structure (0 times) was washed 50 times at 80°C according to the high temperature accelerated washing method specified in the "SEK Mark Textile Product Washing Method" and then air-dried overnight to obtain an antibacterial and antifungal fiber structure (KL50 times).

[Examples 2 to 19, Comparative Example 1]
Antibacterial and antifungal fiber structures were obtained in the same manner as in Example 1, except that the composition of the processing liquid, the heating step, and the fiber structure were as shown in Tables 2 to 4. In Comparative Example 1, a urethane binder (urethane-based compound) was used as the film-forming compound.

The obtained Example products and Comparative Example products were evaluated for texture and discoloration by the methods described below, and tests were also conducted using the above-mentioned methods for deodorizing properties against acetic acid, antibacterial properties against Klebsiella pneumoniae, and antifungal properties against Trichophyton, and the deodorizing rate, antibacterial activity value, and antifungal activity value were calculated.
The antibacterial activity, antifungal activity and deodorizing properties were evaluated based on the obtained antibacterial activity and antifungal activity values in accordance with the indices shown below. These results are shown in Tables 2 to 4 below.
Regarding texture and discoloration, only the antibacterial and antifungal fiber structure (0 times) was measured and evaluated.

<Texture>
A sensory evaluation was carried out by 10 monitors.
That is, the textures such as feel and hardness of the fiber structures before and after treatment were compared by directly touching them, and the feel of the fiber structures before treatment was evaluated based on the following indexes, with the most common evaluation among the 10 monitors being used as the evaluation.
◯ (Good): The feel after treatment is the same as or better than before treatment.
× (bad): The feel after treatment is worse than before treatment.

<Discoloration>
A sensory evaluation was carried out by 10 monitors.
That is, the color tone of the fiber structure before and after treatment was visually observed, and the change in color tone compared to the fiber structure before treatment was evaluated based on the following index, with the most common evaluation among the 10 monitors being used as the evaluation.
◯ (Good): The color after treatment is the same as or better than before treatment.
× (bad): The color tone after processing is poor compared to before processing.

<Antibacterial>
The evaluation was carried out as follows in accordance with the "SEK Mark Textile Product Certification Standards" of the Japan Textile Evaluation Technology Council.
◯ (Good): Antibacterial activity value of 2.0 or more × (Bad): Antibacterial activity value of less than 2.0

<Antifungal properties>
The antifungal activity value was evaluated based on the following indexes.
◎ (Very effective)... "2" or more, which represents 1/100 of the growth value of the untreated fiber structure. 〇 (Effective)... "1" or more, but less than "2", which represents 1/10 of the growth value of the untreated fiber structure. × (Ineffective)... Untreated fiber structure is less than "1".

<Deodorizing properties>
Measurements were carried out in accordance with the performance test method for deodorizing processed textile products (ISO 17299-3 gas chromatography method) and the evaluation was based on the following indices.
◎ (Very good)...70% or more 〇 (Good)...50% or more but less than 70% × (Bad)...less than 50%

In addition, the amount of each component fixed to the antibacterial and antifungal fiber structures obtained in each example and comparative example was calculated and is shown in Tables 5 to 7 below.

As shown in Tables 2 to 7, Examples 1 to 19 had a good texture, did not discolor, and had deodorizing, antibacterial, and antifungal properties that were highly durable against washing.
On the other hand, Comparative Example 1, in which a film-forming compound was added, provided antibacterial properties, but was inferior in texture and further caused discoloration, making it unsuitable for use in clothing, bedding, etc. that come into direct contact with the skin.
Although the results for acetic acid are shown for the evaluation of deodorizing properties, similar trends were observed for ammonia and isovaleric acid.
The results for the antibacterial evaluation using Klebsiella pneumoniae are shown, but similar trends were observed for Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Escherichia coli, Salmonella, and Pseudomonas aeruginosa.
In addition, the results for the evaluation of antifungal activity against Trichophyton were shown, but the same tendency was observed for antifungal activity against Aspergillus niger.
Furthermore, the results are shown for those having PET, nylon, and cotton as the fiber structure, but the same tendency was observed for those having acrylic.

The antibacterial and antifungal fiber structure of the present invention is highly safe and has antibacterial and antifungal properties that are durable to washing, making it suitable for use in clothing, bedding, and other items that come into direct contact with the skin.

REFERENCE SIGNS LIST 1 Treatment tank 2 Fiber structure 3 Squeeze roll 4 Heating device 5 Dryer 6 Processing liquid

Claims (17)

A method for producing an antibacterial and antifungal fiber structure in which a metal oxide (A) contained in an antibacterial and antifungal composition is directly fixed to the surface of the fiber structure, comprising the steps of:
a machining fluid preparation step of preparing a machining fluid containing the antibacterial and antifungal composition and not containing a film-forming compound;
a processing solution heating step of applying the processing solution to the fiber structure and heating the fiber structure at 100 to 230°C under normal pressure or pressure for 0.5 minutes or more;
A method for producing an antibacterial and antifungal fiber structure, comprising directly fixing the metal oxide (A) in an amount of 0.02 parts by mass or more per 100 parts by mass of the fiber structure. The method for producing an antibacterial and antifungal fiber structure according to claim 1, wherein the metal oxide (A) contained in the antibacterial and antifungal composition is spot-fixed to the surface of the fiber structure. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the metal oxide (A) contained in the antibacterial and antifungal composition is at least one compound selected from the group consisting of zinc oxide, titanium oxide, silver oxide, and copper oxide. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the antibacterial and antifungal composition further contains an isothiazolinone compound (B). The method for producing an antibacterial and antifungal fiber structure according to claim 4, wherein the isothiazolin-based compound (B) contained in the antibacterial and antifungal composition is at least one compound selected from the group consisting of 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 4-chloro-2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one. The method for producing an antibacterial and antifungal fiber structure according to claim 4, wherein the mass ratio (B/A) of the isothiazolinone compound (B) to the metal oxide (A) in the antibacterial and antifungal composition is set to 0.01 to 0.25. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the metal oxide (A) is composed of particles having a particle diameter of 100 to 400 nm in an amount of 50 mass% or more. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the film-forming compound is at least one selected from the group consisting of acrylic compounds, urethane compounds, silicone compounds, epoxy compounds, polyester compounds, and melamine compounds. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the processing liquid contains phosphoric acid and/or citric acid. The method for producing an antibacterial and antifungal fiber structure according to claim 1 or 2, wherein the pH of the processing liquid is in the range of 3 to 6. An antibacterial and antifungal fiber structure in which a metal oxide (A) is directly fixed in an amount of 0.02 parts by mass or more per 100 parts by mass of the fiber structure,
The antibacterial activity value is 2.0 or more,
An antibacterial and antifungal fiber structure having an antifungal activity value of 1 or more. The antibacterial and antifungal fiber structure according to claim 11, wherein the fiber structure comprises synthetic fibers. After 10 washes using the standard washing method (washing method for SEK mark textile products),
The antibacterial activity value is 2.0 or more,
The antibacterial and antifungal fiber structure according to claim 11 or 12, which has an antifungal activity value of 1 or more. After 50 washes using the high-temperature accelerated washing method (washing method for SEK mark textile products),
The antibacterial activity value is 2.0 or more,
The antibacterial and antifungal fiber structure according to claim 11 or 12, which has an antifungal activity value of 1 or more. After 10 washes using the standard washing method (washing method for SEK mark textile products),
13. The antibacterial and antifungal fiber structure according to claim 11 or 12, which has a deodorizing rate of 50% or more for at least one odor of ammonia, acetic acid, and isovaleric acid. The antibacterial and antifungal fiber structure according to claim 11 or 12, further comprising an isothiazolinone compound (B) directly fixed to a fiber structure having synthetic fibers, and wherein the ratio of the isothiazolinone compound (B) to 1 part by mass of the metal oxide (A) is set to 0.01 to 0.25 parts by mass. The antibacterial and antifungal fiber structure according to claim 11 or 12, wherein the metal oxide (A) is composed of particles having a particle diameter of 100 to 400 nm in an amount of 50% by mass or more.