Fiber material and production method for same

Abstract

A fiber material (10) comprises a fiber body (12), a binder film (14), and supported particles (20). The fiber body is at least one type of fiber from among cellulose-based fibers, animal fibers, and synthetic fibers. The supported particles are supported on a surface of the fiber body with the binder film therebetween. The supported particles have a first particle (16) that contains a quaternary ammonium salt and a second particle (18) that comprises a metal oxide which can reduce iodine. The binder film includes a silicone-based binder and a urethane-based binder.

Description

Fiber material and its manufacturing method

[0001] The present invention relates to textiles that exhibit antiviral and antibacterial properties, and to methods for producing such textiles.

[0002] It is predicted that a living body wearing clothing that exhibits antiviral properties will be less susceptible to viral infection. In the case of a human being, it is expected that the living body will be prevented from contracting a disease caused by the virus. From this perspective, the present applicant has proposed in International Publication No. 2017 / 199420 a textile material that supports Al-doped zinc oxide on its surface and exhibits antiviral properties.

[0003] Clothing is washed repeatedly, and there is a demand for textile materials that maintain sufficient antiviral properties even after repeated washing.

[0004] The present invention aims to solve the above-mentioned problems.

[0005] According to one embodiment of the present invention, there is provided a fiber material comprising a fiber body containing at least one of cellulose-based fiber, animal fiber, and synthetic fiber, and support particles supported on the surface of the fiber body via a binder film, wherein the support particles have first particles containing a quaternary ammonium salt and second particles made of a metal oxide capable of reducing iodine, and the binder film contains a silicone-based binder and a urethane-based binder.

[0006] According to another embodiment of the present invention, there is provided a method for producing a fiber material comprising a fiber body containing at least one of cellulose-based fibers, animal fibers, and synthetic fibers, and support particles supported on the surface of the fiber body via a binder film, the method comprising: an immersion step in which the fiber body is immersed in an anion-rich aqueous dispersion in which a quaternary ammonium salt, a metal oxide capable of reducing iodine, a silicone-based binder, and a urethane-based binder are co-processed; and a heating step in which a binder film is formed from the silicone-based binder and the urethane-based binder by heat treatment, wherein in the heating step, the support particles, which have first particles containing the quaternary ammonium salt and second particles made of the metal oxide, are supported on the surface of the fiber body via the binder film to obtain a fiber material.

[0007] Even if the above-mentioned fiber material is washed repeatedly, the state in which the particles are supported on the surface of the fiber body via the binder film is maintained, and therefore the fiber material exhibits excellent antiviral and antibacterial performance for a long period of time based on the particles supported on the surface of the fiber body.

[0008] Fig. 1 is an enlarged plan view of a main portion of a woven fabric obtained from a fibrous material. Fig. 2 is a schematic cross-sectional view of the fibrous material as viewed from a direction perpendicular to the longitudinal direction. Fig. 3 is a schematic flow diagram of a method for producing a fibrous material. Figs. 4A and 4B are schematic flows of a method for evaluating a fibrous material. Fig. 5 is a schematic diagram showing the degree of fading of an iodine aqueous solution over time. Fig. 6 is a diagram showing the relationship between the concentration of each component in a treatment solution and the durability of antiviral and antibacterial performance in a fibrous material.

[0009] In the following embodiment, a woven fabric 30 (see FIG. 1 ) obtained from the fiber material 10 will be described as an example. However, the form of the fiber material 10 is not limited to the woven fabric 30. For example, other textiles, yarns, cotton, fiber bundles, woven fabrics, knitted fabrics, nonwoven fabrics, etc. may be obtained from the fiber material 10 in addition to the woven fabric 30. The fiber material 10 may also be a towel having pile yarns.

[0010] FIG. 1 is an enlarged plan view of a main portion of a woven fabric 30 obtained from a fiber material 10 according to this embodiment. The woven fabric 30 is obtained by weaving warp yarns 32 made of the fiber material 10 and weft yarns 34 made of the fiber material 10. The warp yarns 32 and weft yarns 34 may be single yarns or two-ply yarns. Furthermore, the woven fabric 30 may be a yarn obtained by spinning cotton through a drawing process after conventional functional processing. Note that FIG. 1 shows a woven fabric 30 obtained by plain weaving. However, the woven fabric 30 may also be obtained by twill weaving or satin weaving.

[0011] The fiber material 10 has been subjected to predetermined treatments such as scouring and bleaching, and has also been subjected to a supporting treatment, which will be described later. The woven fabric 30 may or may not be dyed.

[0012] 2, the fibrous material 10 includes a fiber body 12, a binder film 14, and support particles 20. The support particles 20 include first particles 16 containing a quaternary ammonium salt and second particles 18 made of a metal oxide.

[0013] The fiber body 12 contains at least one of cellulosic fiber, animal fiber, and synthetic fiber. In other words, the material of the fiber body 12 may be only one of cellulosic fiber, animal fiber, and synthetic fiber, or may be two or more of cellulosic fiber, animal fiber, and synthetic fiber. The proportion of cellulosic fiber, animal fiber, and synthetic fiber in the fiber body 12 can be set within a desired range.

[0014] A typical example of a cellulosic fiber is cotton, a natural plant fiber. Other examples of cellulosic fibers include ramie, linen, hemp, jute, Manila hemp, sisal, and other hemp. The cellulosic fiber may be a regenerated fiber. Regenerated fibers are obtained by dissolving natural cellulose in a specific solvent and then forming it into a fibrous form. Specific examples of regenerated fibers include rayon, Polynosic, cupra, and Tencel (a registered trademark of Rensing GmbH, Austria).

[0015] Representative examples of animal fibers include silk, wool, and animal hair fibers. Specific examples of animal hair fibers include alpaca, mohair, angora, cashmere, camel, and buccuna. Examples of synthetic fibers include polyester, polyurethane, aliphatic polyamide fibers (such as nylon 6 or nylon 6,6), and aromatic polyamide fibers.

[0016] For example, when the fiber body 12 contains cellulosic fibers and animal fibers, the woven fabric 30 may be a fabric made using raw yarns of both fibers (blended yarns or twisted yarns), or may be a cross-woven fabric made using raw yarns of cellulosic fibers and raw yarns of animal fibers.

[0017] First particles 16 containing a quaternary ammonium salt and second particles 18 containing a metal oxide are supported on the surface of the fiber body 12 via a binder film 14. The quaternary ammonium salt is a complex or association of a quaternary ammonium cation and an anion that is bonded to the quaternary ammonium cation as a counterion by electrostatic action. - When the formula is expressed as follows, the general formula of the quaternary ammonium salt is expressed as follows:

[0018]

[0019] Here, typical examples of R1 are alkyl groups or alkoxysilane groups. Typical examples of R2 and R3 are methyl groups or ethyl groups. A preferred value for n is an integer between 6 and 18, and a more preferred value for n is 10 or 11. Typical examples of X are halogen or organic acids. In one embodiment, the first particles 16 containing a quaternary ammonium salt are solubilized in an anion-rich solution. In this case, the first particles 16 are encapsulated in association bodies of anionic surfactants contained in the anion-rich solution.

[0020] The quaternary ammonium salt may be a polymer type or a silane type. When the quaternary ammonium salt is a polymer type, the repeating unit preferably has a main chain carbon number of 7 to 12 and a molecular weight of 200 to 240. The polymer type quaternary ammonium salt may be a condensation polymer of a compound having a quaternary ammonium group and an amine compound. In this case, the preferred molecular weight of the monomer is in the range of 200 to 240.

[0021] Quaternary ammonium salts exhibit cationic properties. In contrast, in an anion-rich aqueous solution containing a quaternary ammonium salt and an anionic surfactant in a concentration range of 40 to 100 mM, and in which the molar concentration of the anionic surfactant is adjusted to at least four times the molar concentration of the quaternary ammonium salt, an association of the quaternary ammonium salt and the anionic surfactant is formed. Alternatively, an anionic surfactant association encapsulating a complex of the quaternary ammonium salt and the anionic surfactant is formed and solubilized. As a result, a liquid containing a quaternary ammonium salt and an anionic surfactant exhibits anionic properties.

[0022] Suitable examples of anionic surfactants include phosphate ester surfactants, sulfate ester surfactants, carboxylic acid surfactants, and sulfonic acid surfactants. When a phosphate ester surfactant is used, the alkyl group substituted for H in the hydroxyl group of the phosphoric acid is preferably an alkyl group having 8 to 12 carbon atoms. The molecular weight of the phosphate ester surfactant is preferably in the range of 250 to 380. Furthermore, the phosphate ester surfactant is preferably a dehydration condensation product of a primary alcohol having any number of carbon atoms and tetraphosphorus hexaoxide, and has a molecular weight in the range of 250 to 380. The dehydration condensation product may be any of a mono-type, a di-type, or a mixture of a mono-type and a di-type.

[0023] The first particles 16 having the above-described quaternary ammonium salt as a base material mainly exhibit antiviral properties.

[0024] If the woven fabric 30 is not dyed, a user may wish to dye the woven fabric 30. If the quaternary ammonium salt is cationic, the dye tends to be attracted to the quaternary ammonium cation. This may result in dye spots. To avoid this problem, it is preferable that the quaternary ammonium salt is solubilized as a result of being encapsulated in an aggregate of an anionic surfactant at a molar concentration of at least four times the quaternary ammonium salt, and that the charge of the entire dispersion be anionic.

[0025] As the metal oxide, a substance that exhibits antibacterial properties and can reduce iodine is mainly used. Specific examples of such metal oxides include zinc oxide (ZnO), titanium oxide (TiO2), and tin oxide (SnO2). Of these, ZnO is most preferable because it has the highest reducing power for iodine. ZnO may be doped with a Group 13 element to improve its reducing power for iodine. A typical example of a Group 13 element is aluminum (Al).

[0026] The first particles 16 containing a quaternary ammonium salt and the second particles 18 made of a metal oxide are held on the surface of the fiber body 12 via a binder film 14. The binder film 14 is, for example, a single film made of a physical mixture of a silicone-based binder and a urethane-based binder. Alternatively, the binder film 14 may be a compound film in which the silicone-based binder and the urethane-based binder are chemically bonded. Even if the fiber material 10 is cotton, by co-treating it with a metal oxide and a silicone-based binder, the second particles 18 can be attached to the surface of the cotton and sufficient washing durability can be imparted to the antibacterial performance.

[0027] The binder film 14 is physically fixed to the surface of the fiber body 12 mainly by mechanical action such as the anchor effect. That is, the majority of functional groups in the fiber body 12 are not chemically bonded to either the functional groups of the silicone-based binder or the functional groups of the urethane-based binder. Therefore, the functional groups in the fiber body 12 exhibit sufficient activity toward the dye. Moreover, the dye easily passes through the binder film 14. Furthermore, the functional groups in the fiber body 12 are hydrophilic and attract water molecules.

[0028] For the reasons described above, the fiber body 12 is easily dyed, even though the first particles 16 and the second particles 18 are supported on the surface via a silicone-based binder and a urethane-based binder. That is, the fiber material 10 has excellent dyeability. Therefore, it is possible to perform so-called piece dyeing on the fiber material 10 after the supporting treatment.

[0029] Therefore, while storing the woven fabric 30 in an undyed state, it is possible to collect information on trendy colors, dye the fabric 30 based on that information, and then ship the finished product. In other words, it is possible to provide products that accurately capture rapidly changing fashion colors or patterns in a short period of time. This reduces dead stock of the fiber material 10 and the woven fabric 30. However, it is also possible to obtain the fiber material 10 by performing a support treatment on the fiber body 12 after dyeing.

[0030] Furthermore, the binder film 14 exhibits good elasticity. Therefore, when the woven fabric 30 is deformed, the binder film 14 deforms accordingly. This allows the binder film 14 to remain firmly attached to the surface of the fiber body 12. Therefore, the first particles 16 and the second particles 18 are maintained supported on the surface of the fiber body 12 via the binder film 14.

[0031] Therefore, even if frictional force or the like is applied to the woven fabric 30 in water while the woven fabric 30 is being washed, the binder film 14, the first particles 16, and the second particles 18 are prevented from falling off the surface of the fiber body 12. As a result, the antiviral and antibacterial properties of the woven fabric 30 (fiber material 10) are maintained for a long period of time.

[0032] Specifically, after washing the textile material 10 100 times, the antiviral activity values ​​(Mv) for influenza A virus and SARS-CoV-2 mutant strain (Omicron strain) were 2.1 and 3.3, respectively. In influenza A virus, the nucleic acid encapsulated by the capsid is RNA. In addition, influenza A virus has an envelope.

[0033] Furthermore, after the fabric material 10 was washed 100 times, the antibacterial activity values ​​(A) for Staphylococcus aureus, Moraxella, Escherichia coli, and Klebsiella pneumoniae were 6.0, 6.1, 6.2, and 6.0, respectively.

[0034] When the binder film 14 does not contain either a silicone-based binder or a urethane-based binder, the adhesive strength of the binder film 14 to the fiber body 12 is weaker than when the binder film 14 contains both a silicone-based binder and a urethane-based binder. For this reason, the antiviral and antibacterial performance of the former binder film 14 decreases in a relatively short period of time compared to the latter binder film 14. As can be seen from this, by forming the binder film 14 using both a silicone-based binder and a urethane-based binder, the antiviral and antibacterial performance can be maintained for a relatively long period of time.

[0035] Next, a method for manufacturing the fiber material 10 will be described. As shown in Fig. 3, this manufacturing method includes a dipping step S1 and a heating step S2. The dipping step S1 and the heating step S2 are support treatments for supporting the first particles 16 and the second particles 18 on the surface of the fiber body 12.

[0036] First, an anion-rich aqueous solution is prepared. Specifically, a quaternary ammonium salt and an anionic surfactant are added to the aqueous solvent so that the total concentration is in the range of 40 to 100 mM. Here, the molar concentration of the anionic surfactant is at least four times that of the quaternary ammonium salt. By adjusting the molar concentrations of the anionic surfactant and the quaternary ammonium salt as described above, the aqueous solution becomes anion-rich. The quaternary ammonium salt and the anionic surfactant form the above-mentioned complex or aggregate. However, the complex is encapsulated in the anionic surfactant aggregate and, as a result, is solubilized. Hereinafter, the complex or aggregate of the quaternary ammonium salt and the anionic surfactant may be referred to as an "anionic dispersion."

[0037] Specific examples of the anionic surfactant include the phosphate ester surfactants, sulfate ester surfactants, carboxylic acid surfactants, and sulfonic acid surfactants, as described above.

[0038] Metal oxide particles, a silicone-based binder, and a urethane-based binder are added to and dispersed in the aqueous solution containing the anionic dispersion, thereby preparing an anion-rich aqueous dispersion. In the aqueous dispersion, the concentration of the anionic dispersion is adjusted to, for example, 0.5 to 20%. In the aqueous dispersion, the concentration of the metal oxide is adjusted to, for example, 0.2 to 10%. In the aqueous dispersion, the concentrations of the silicone-based binder and the urethane-based binder are each adjusted to, for example, 0.1 to 10%.

[0039] Silicone compounds and urethane compounds are generally anionic and tend to chemically aggregate with quaternary ammonium cations. In contrast, in the anion-rich aqueous dispersion, the quaternary ammonium cations form anionic dispersions with anionic surfactants at a molar concentration four times or more that of the quaternary ammonium cations. The anionic dispersions are soluble in aqueous solvents. Therefore, the aqueous dispersions are anionically charged. Therefore, chemical aggregation between the anionic dispersions and the silicone compounds and urethane compounds is suppressed.

[0040] Next, in the immersion step S1, the fiber body 12 is immersed in the aqueous dispersion. At this point, the fiber body 12 may be a single body before being woven, or may have been woven into a woven fabric 30 or the like. By immersing the fiber body 12 (or the woven fabric 30) in the aqueous dispersion, silicone-based compounds, urethane-based compounds, quaternary ammonium salts, and metal oxides adhere to the surface of the fiber body 12. In particular, when an aqueous dispersion containing an anionic surfactant in an anion-rich state is used, the silicone-based compounds, urethane-based compounds, quaternary ammonium salts, and metal oxides easily reach the surface of the fiber body 12.

[0041] The fiber material 10 is then squeezed out and subjected to a heating treatment in a heating step S2. The fiber material 10 may be dried before the heating treatment is performed. In other words, a drying step may be performed between the immersion step S1 and the heating step S2.

[0042] The heat treatment causes crosslinking between the silicone compound and the urethane compound, forming a binder film 14. Furthermore, particles containing a quaternary ammonium salt (first particles 16) and particles made of a metal oxide (second particles 18) are supported on the surface of the fiber body 12 via the binder film 14. As a result, the fiber material 10 is obtained. The heat treatment can be carried out by, for example, dry heat treatment or steam setting.

[0043] In the fibrous material 10 obtained through the above process, as shown in Figure 2, the binder film 14 is physically bonded to the surface of the fiber body 12 mainly by the anchor effect. The binder film 14 freely deforms in response to deformation of the fibrous material 10. Therefore, the first particles 16 and the second particles 18 are less likely to fall off from the surface of the fiber body 12. Furthermore, the first particles 16 and the second particles 18 provide the fibrous material 10 with effective antiviral and antibacterial properties against, for example, influenza A virus, Staphylococcus aureus, and Klebsiella pneumoniae.

[0044] Furthermore, in the fiber material 10, the functional groups of the fiber body 12 are in an active state that allows them to chemically bond with dyes. This gives the fiber material 10 excellent dyeability. Therefore, the fiber material 10 can be easily piece-dyed. Furthermore, when the quaternary ammonium cation forms an anionic dispersion together with the anionic surfactant, the dye can easily reach the surface of the fiber body 12. Therefore, in this case, the fiber material 10 can be even more easily piece-dyed.

[0045] Next, a method for evaluating the fiber material 10 according to this embodiment will be described. This evaluation method is a method for visually evaluating whether or not the fiber material 10 has antiviral and antibacterial properties.

[0046] Specifically, the evaluation method includes a color test and a color fading test, as shown in FIG. 4A . It is possible to determine whether the textile material 10 exhibits antiviral performance based on the results of the color test. It is also possible to determine whether the textile material 10 exhibits antibacterial performance based on the results of the color fading test. The color test and the color fading test can be performed in any order. That is, for the same textile material 10, the color fading test may be performed after the color fading test, as shown in FIG. 4A , or the color test may be performed after the color fading test, as shown in FIG. 4B .

[0047] The following describes an example of evaluating the antiviral and antibacterial properties of the woven fabric 30. In this case, a color test and a color fading test can be performed on the woven fabric 30. In other words, there is no need to unravel the woven fabric 30 or to dissolve the woven fabric 30.

[0048] In the coloration test, the woven fabric 30 is immersed in an acetic acid solution adjusted to a pH of 3 to 4 at 50 to 100°C. In this state, a quaternary ammonium salt test paper is immersed in the acetic acid solution. If the quaternary ammonium salt (first particles 16) is supported on the woven fabric 30, the quaternary ammonium salt test paper will be green or blue. Based on this coloration, it can be determined that the quaternary ammonium salt (first particles 16) is supported on the woven fabric 30. Furthermore, the woven fabric 30 exhibits antiviral performance based on the presence of the quaternary ammonium salt. Therefore, based on the green or blue coloration of the quaternary ammonium salt test paper, it can be evaluated that the woven fabric 30 exhibits antiviral performance due to the quaternary ammonium salt.

[0049] In contrast, the color of the quaternary ammonium salt test paper does not change when the quaternary ammonium salt (first particles 16) has fallen off from the woven fabric 30. Based on this, it can be evaluated that the woven fabric 30 has lost the antiviral performance due to the quaternary ammonium salt.

[0050] In the color fading test, the woven fabric 30 is immersed in an iodine aqueous solution, and then a starch aqueous solution is added to the iodine aqueous solution and allowed to stand. The iodine-starch reaction between the starch and iodine proceeds rapidly, causing the iodine aqueous solution to assume a bluish-purple color. If a metal oxide (second particles 18) is supported on the woven fabric 30, the iodine is reduced by the metal oxide when the woven fabric 30 is allowed to stand in this state. Accordingly, as shown in the "Antibacterial Performance" column in FIG. 5 , the iodine aqueous solution changes from bluish-purple to transparent over time. That is, the bluish-purple color of the iodine aqueous solution fades.

[0051] Based on this discoloration, it can be determined that metal oxide (second particles 18) is supported on the woven fabric 30. Furthermore, the woven fabric 30 exhibits antibacterial properties based on the presence of metal oxide. Therefore, based on the discoloration of the iodine solution, it can be evaluated that the woven fabric 30 exhibits antibacterial properties due to metal oxide.

[0052] In contrast, when the metal oxide (second particles 18) has fallen off from the woven fabric 30, the iodine aqueous solution does not fade over time, as shown in the "No antibacterial performance" column in Figure 5. Alternatively, the iodine aqueous solution fades slowly. Based on this, it can be evaluated that the woven fabric 30 has lost the antibacterial performance provided by the metal oxide.

[0053] As described above, by performing the coloration test and the color fading test, it is possible to visually evaluate whether the woven fabric 30 exhibits antiviral and antibacterial properties. Therefore, it is easy to determine whether the woven fabric 30 maintains its antiviral and antibacterial properties after repeated washing of the woven fabric 30, for example.

[0054] Moreover, the color change test and the color fading test are non-destructive tests, so that after it is determined that the woven fabric 30 maintains its antiviral and antibacterial properties, the woven fabric 30 can continue to be used.

[0055] This embodiment has the following advantages.

[0056] The fiber material 10 comprises a fiber body 12 containing at least one of cellulosic fiber, animal fiber, and synthetic fiber, and supported particles 20 supported on the surface of the fiber body 12 via a binder film 14. The supported particles 20 have first particles 16 containing a quaternary ammonium salt and second particles 18 made of a metal oxide capable of reducing iodine. The binder film 14 contains a silicone-based binder and a urethane-based binder.

[0057] The fiber material 10 exhibits excellent antiviral and antibacterial properties based on the support particles 20 supported on the surface of the fiber body 12. When the support particles 20 are supported on the surface of the fiber body 12 by the binder film 14, the support particles 20 remain supported on the surface of the fiber body 12 via the binder film 14 even after repeated washing of the fiber material 10. Therefore, the fiber material 10 can maintain antiviral and antibacterial properties for a long period of time.

[0058] The first particles 16 are, for example, an association or complex (anionic dispersion) of a quaternary ammonium salt and an anionic surfactant. When forming a complex, the quaternary ammonium salt is encapsulated and solubilized in an association (micelle, etc.) of the anionic surfactant. Because the anionic dispersion is soluble in an aqueous solvent, when the fiber material 10 is immersed in the aqueous solvent, the aqueous solvent becomes anionically charged. In this case, it is easy to dye the fiber body 12 on whose surface the support particles 20 are supported. Therefore, the user can dye the fiber material 10 to the desired color.

[0059] The metal oxide is, for example, zinc oxide, titanium oxide, or tin oxide. These metal oxides have a high reducing power against iodine, so it is easy to grasp the degree of fading in the fading test.

[0060] The metal oxide is, for example, a metal oxide doped with a Group 13 element. This is because a metal oxide doped with a Group 13 element has a greater reducing power for iodine than a metal oxide not doped with a dopant. Therefore, it is easier to determine the degree of discoloration in a discoloration test.

[0061] An example of a Group 13 element is aluminum. Aluminum-doped metal oxides are relatively inexpensive, which can reduce the manufacturing cost of the fiber material 10. A typical example of an aluminum-doped metal oxide is Al—ZnO.

[0062] The binder film 14 is, for example, a single film made of a mixture of a silicone-based binder and a urethane-based binder. That is, there is no particular need to form a binder film made of a compound of a silicone-based binder and a urethane-based binder. In other words, there is no particular need to chemically react the silicone-based binder and the urethane-based binder. Therefore, no equipment is required to cause a chemical reaction. This allows for reduced capital investment. However, the silicone-based binder and the urethane-based binder may also be chemically reacted.

[0063] The method for producing the fiber material 10 includes a dipping step S1 and a heating step S2. In the dipping step S1, the fiber body 12 is dipped into an anion-rich aqueous dispersion in which a quaternary ammonium salt, a metal oxide capable of reducing iodine, a silicone-based binder, and a urethane-based binder are co-processed. In the heating step S2, the fiber material 10 is subjected to a heat treatment, and a binder film 14 is formed from the silicone-based binder and the urethane-based binder.

[0064] In the heating step S2, supported particles 20 having first particles 16 containing a quaternary ammonium salt and second particles 18 made of a metal oxide are supported on the surface of the fiber body 12 via the binder film 14. This results in a fiber material 10 that exhibits antiviral and antibacterial properties based on the presence of the first particles 16 and the second particles 18.

[0065] In the immersion step S1, an aqueous dispersion liquid that has been made anion-rich by adding an anionic surfactant is used. In this case, it is easy to dye the fiber body 12 on the surface of which the support particles 20 are supported. Therefore, by dyeing the fiber material 10 after the heating step, the user can dye the fiber material 10 to the color desired by the user.

[0066] The metal oxide may be zinc oxide, titanium oxide, or tin oxide. These metal oxides have a high reducing power against iodine, making it easy to determine the degree of fading in the fading test.

[0067] The heat treatment in the heating step S2 is carried out by dry heat treatment in heat setting or steam setting.

[0068] In addition to the above disclosure, the following additional notes are disclosed.

[0069] (Note 1) The fiber material (10) comprises a fiber body (12) containing at least one of cellulosic fiber, animal fiber, and synthetic fiber, and support particles (20) supported on the surface of the fiber body via a binder film (14). The support particles include first particles (16) containing a quaternary ammonium salt and second particles (18) made of a metal oxide capable of reducing iodine. The binder film contains a silicone-based binder and a urethane-based binder.

[0070] The fiber material exhibits excellent antiviral and antibacterial properties based on the supported particles carried on the surface of the fiber body. Here, when the first particles and the second particles are carried on the surface of the fiber body by the above-mentioned binder film, the supported particles are maintained in a state of being carried on the surface of the fiber body via the binder film even after repeated washing of the fiber material. Therefore, the fiber material can maintain antiviral and antibacterial properties for a long period of time.

[0071] (Appendix 2) In the fiber material described in Appendix 1, the first particles may include a complex or aggregate of a quaternary ammonium salt and an anionic surfactant. In the complex, the quaternary ammonium salt is encapsulated and solubilized in the anionic surfactant in an anionic surfactant-rich state. In this case, it is easy to dye the fiber body with the support particles supported on the surface. Therefore, users can dye the fiber material to the desired color.

[0072] (Supplementary Note 3) In the fiber material described in Supplementary Note 1 or 2, the metal oxide may be zinc oxide, titanium oxide, or tin oxide. This is because these metal oxides have a high reducing power against iodine. Therefore, it is easy to grasp the degree of fading in a fading test.

[0073] (Appendix 4) In the fiber material according to any one of Appendices 1 to 3, the metal oxide may be a metal oxide doped with a Group 13 element. This is because a metal oxide doped with a Group 13 element has a greater reducing power for iodine than a metal oxide not doped with a dopant. Therefore, it is easier to determine the degree of fading in a fading test.

[0074] (Supplementary Note 5) In the fiber material according to Supplementary Note 4, the Group 13 element may be aluminum. Since aluminum-doped metal oxides are relatively inexpensive, the manufacturing cost of the fiber material can be reduced.

[0075] (Appendix 6) In the fiber material described in any one of Appendices 1 to 5, the binder film may be a single film made of a mixture of the silicone-based binder and the urethane-based binder. In this case, there is no need to chemically react the silicone-based binder and the urethane-based binder, so no equipment for causing a chemical reaction is required. This allows for reduced capital investment.

[0076] (Appendix 7) The method for producing the above-mentioned fiber material (10) includes an immersion step (S1) and a heating step (S2). In the immersion step, the fiber body is immersed in an anion-rich aqueous dispersion obtained by co-processing a quaternary ammonium salt, a metal oxide capable of reducing iodine, a silicone-based binder, and a urethane-based binder. In the heating step, the fiber material is subjected to a heat treatment, and a binder film (14) is formed from the silicone-based binder and the urethane-based binder.

[0077] In the heating step, supported particles (20) having first particles (16) containing the quaternary ammonium salt and second particles (18) made of the metal oxide are supported on the surface of the fiber body via the binder film, thereby obtaining a fiber material that exhibits antiviral and antibacterial properties based on the presence of the first and second particles.

[0078] (Appendix 8) In the manufacturing method described in Appendix 7, an anionic surfactant may be added to the aqueous dispersion to make the aqueous dispersion an anionic liquid. In this case, it is easy to dye the fiber body having the support particles supported on its surface. Therefore, by dyeing the fiber material after the heating step, the user can dye the fiber material in the color desired by the user.

[0079] (Appendix 9) In the production method described in Appendix 8, the sum of the molar concentrations of the quaternary ammonium salt and the anionic surfactant in the aqueous dispersion may be 40 to 100 mM, and the molar concentration of the anionic surfactant may be at least four times the molar concentration of the quaternary ammonium salt (co-processing). Under these conditions, the quaternary ammonium salt and the anionic surfactant readily form a complex or aggregate. The complex is an anionic surfactant-rich state in which the quaternary ammonium salt is encapsulated in the anionic surfactant, resulting in solubilization.

[0080] (Supplementary Note 10) In the manufacturing method according to any one of Supplementary Notes 7 to 9, the metal oxide may be zinc oxide, titanium oxide, or tin oxide. These metal oxides have a high reducing power against iodine. Therefore, it is easy to grasp the degree of fading in a fading test.

[0081] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

[0082] In the following, "control" refers to towels or the like that have been immersed in a treatment solution described below and treated. The control has not been washed. "Sample" refers to towels or the like obtained by washing the control 100 times.

[0083] [Evaluation of antiviral performance] A plurality of towels were woven using 100% cotton two-ply yarn (40 / 2) with a count of 40 as the ground warp, 100% cotton single yarn (20 / 1) with a count of 20 as the weft, and 100% cotton single yarn (20 / 1) with a count of 20 as the pile warp, and each of the plurality of towels was scoured and bleached by a conventional method.

[0084] Meanwhile, a treatment liquid was obtained by adding a quaternary ammonium salt aqueous dispersion, a zinc oxide dispersion, a silicone-based binder dispersion, and a urethane-based binder dispersion to water and mixing them. Here, the quaternary ammonium salt aqueous dispersion was obtained by adding an anionic surfactant and a quaternary ammonium salt to an aqueous solvent. The cationic component of the quaternary ammonium salt was dodecyltrimethylammonium salt. The anionic surfactant was a dehydration condensate obtained by a conventional method from a mixture of 3 parts by mass of lauryl alcohol and 1 part by mass of tetraphosphorus decoxide (phosphoric anhydride). The anionic surfactant and the quaternary ammonium salt were added to the aqueous solvent so that the sum of the molar concentrations of the anionic surfactant and the quaternary ammonium salt was 43.5±1.0 mM, and the molar concentration of the anionic surfactant was at least four times that of the quaternary ammonium salt. As can be seen from the above, the treatment liquid is anion-rich.

[0085] DECBINDER-ST (product name) manufactured by Satoda Chemical Industries, Ltd. and SU-67 (product name) manufactured by Satoda Chemical Industries, Ltd. were used as the silicone-based binder and urethane-based binder, respectively. Furthermore, Z-SDN (product name) manufactured by Satoda Chemical Industries, Ltd. was used as the zinc oxide. Z-SDN is a liquid containing zinc oxide as an active ingredient. Furthermore, the concentrations of the quaternary ammonium salt aqueous dispersion, zinc oxide, silicone-based binder, and urethane-based binder in the treatment liquid were 9%, 3%, 3%, and 6%, respectively.

[0086] Two towels were randomly selected from a number of towels and immersed in this treatment solution. After removing the towels from the treatment solution, they were wrung out using a mangle to a wringing rate of 100%, and then air-dried and heat-treated at 120°C for 4 minutes. This gave two Control A towels.

[0087] Next, the towels were washed in accordance with the C4M method specified in JIS L 1930. Specifically, the towels were washed in wash water to which JAFET standard blend detergent (Textile Evaluation Technology Council) was added at a ratio of 1.33 g / L, and then hung to dry. As a result, two samples A were obtained.

[0088] The same procedure as above was carried out except that the proportions of the quaternary ammonium salt aqueous dispersion, zinc oxide, silicone-based binder, and urethane-based binder were changed as shown in Figure 6, and two each of Controls B to E and Samples B to E were obtained. Control B and Sample B are towels treated with a treatment liquid that does not contain zinc oxide. Control C and Sample C are towels treated with a treatment liquid that does not contain a quaternary ammonium salt aqueous dispersion and a urethane-based binder. Control D and Sample D are towels treated with a treatment liquid that does not contain a urethane-based binder. Control E and Sample E are towels treated with a treatment liquid that does not contain a silicone-based binder.

[0089] The antiviral performance of each of Controls A to E and Samples A to E was evaluated. Specifically, in accordance with the plaque measurement method specified in JIS L 1922, the antiviral activity value (Mv) was calculated for influenza A virus and the SARS-CoV-2 mutant strain (Omicron strain) based on the following formula. However, for the Omicron strain, only Control A and Sample A were evaluated. According to Appendix G of JIS L 1922, an Mv of 3.0 or greater can be judged as "sufficiently effective," and an Mv of 2.0 or greater but less than 3.0 can be judged as "effective." Mv = log(Va) - log(Vc), where log(Va) and log(Vc) are defined as follows: log(Va): Common logarithm of the virus infectivity (PFU / test piece) of the standard cotton fabric immediately after inoculation. log(Vc): Common logarithm of the virus infectivity (PFU / test piece) of the antiviral-treated product after standing for 2 hours.

[0090] The results are shown in Figure 6 along with the proportion of each component in the treatment solution. From Figure 6, it can be seen that both Control A and Sample A can be judged to be "sufficiently effective" against the SARS-CoV-2 mutant strain. Furthermore, it can be seen that Control A can be judged to be "sufficiently effective" and Sample A can be judged to be "effective" against influenza A virus.

[0091] In contrast, although Controls B, D, and E could be judged to be "sufficiently effective" against influenza A virus, Samples B, D, and E had an Mv of less than 1.0. Antiviral performance could not be confirmed for Control C. From the above, it can be seen that a quaternary ammonium salt is necessary to obtain antiviral performance. Here, Sample B did not exhibit antiviral performance after washing. As can be seen from this, zinc oxide and a quaternary ammonium salt are necessary for the washing durability of antiviral performance. It can also be seen that by including both a silicone-based binder and a urethane-based binder in the treatment solution, antiviral performance is maintained even after washing.

[0092] [Coloration Test] Test pieces of 1 g each were cut out from an untreated (unprocessed) towel that had not been immersed in a treatment solution, Controls A to E, and Samples A to E. These test pieces were immersed in an acetic acid solution at 50 to 100°C and adjusted to a pH of 3 to 4. In this state, a quaternary ammonium salt test paper was immersed in the acetic acid solution, and it was observed whether the quaternary ammonium salt test paper developed a color.

[0093] The results are also shown in Figure 6. Note that "Y" indicates that the quaternary ammonium salt test paper turned green or blue. "N" indicates that no coloration was observed. From Figure 6, it can be evaluated that the quaternary ammonium salt was retained in Sample A, which maintained its antiviral performance, while the quaternary ammonium salt was not retained in Samples B, D, and E. In this way, the presence or absence of coloration corresponds to whether or not the antiviral performance was maintained.

[0094] [Evaluation of Antibacterial Performance] The antibacterial performance of each of Controls A to C and one of Samples A to C was evaluated. Specifically, the antibacterial activity value A was calculated for Staphylococcus aureus, Moraxella, Escherichia coli, and Klebsiella pneumoniae based on the following formula in accordance with the bacterial liquid absorption method specified in JIS L 1902. According to Table F of JIS L 1902, an antibacterial activity value A of 3.0 or greater can be judged as "strongly effective," and an antibacterial activity value A of 2.0 or greater but less than 3.0 can be judged as "effective." A = (log(Ct) - log(C0)) - (log(Tt) - log(T0)) Here, log(Ct), log(C0), log(Tt), and log(T0) are defined as follows: log(Ct): Common logarithm of the number of viable bacteria on the standard cotton cloth after 18 to 24 hours of culture log(C0): Common logarithm of the number of viable bacteria on the standard cotton cloth immediately after inoculation log(Tt): Common logarithm of the number of viable bacteria on the test sample after 18 to 24 hours of culture log(T0): Common logarithm of the number of viable bacteria on the test sample immediately after inoculation

[0095] The results are also shown in Figure 6. From Figure 6, it can be determined that both Control A and Sample A are "strongly effective" against all of the above-mentioned bacteria.

[0096] In contrast, control B was not effective against E. coli. Sample B had an antibacterial effect against specific bacteria. On the other hand, control C and sample C can be judged to have a "strong effect" against all of the above bacteria. This shows that zinc oxide is essential for maintaining antibacterial performance, and that by including a silicone-based binder in the treatment liquid, antibacterial performance against various types of bacteria is maintained.

[0097] [Color Fading Test] Rectangular test pieces measuring 3.5 x 5.5 cm were cut from each of the untreated towels, Controls A to E, and Samples A to E. These test pieces were immersed in 25 mL of an iodine aqueous solution with an available iodine concentration of 0.05 to 1.00 mg / mL, and then an aqueous starch solution was added to the iodine aqueous solution and allowed to stand. The iodine aqueous solution exhibited a bluish-purple color. In this state, the iodine aqueous solution was visually observed to determine whether it had faded within 30 minutes of being left standing.

[0098] The results are also shown in Figure 6. Note that "Y" indicates that discoloration was observed in the iodine aqueous solution. "N" indicates that discoloration was not observed in the iodine aqueous solution. From Figure 6, it can be evaluated that zinc oxide is retained in Sample A, which maintains its antibacterial performance against all of the above-mentioned bacteria, while zinc oxide is not retained in Samples B, D, and E. In this way, the presence or absence of discoloration corresponds to whether or not antibacterial performance is maintained.

[0099] These results clearly demonstrate that binding quaternary ammonium salt and zinc oxide to textile materials via silicone-based and urethane-based binders can maintain antiviral and antibacterial properties even after repeated washing. Furthermore, a color test using quaternary ammonium salt test paper can be used to evaluate whether antiviral properties are maintained. Furthermore, a discoloration test using an iodine solution can be used to evaluate whether antibacterial properties are maintained.

[0100] REFERENCE SIGNS LIST 10... Fiber material 12... Fiber body 14... Binder film 16... First particle 18... Second particle 20... Support particle 30... Woven fabric 32... Warp thread 34... Weft thread

Claims

1. A fibrous material (10) comprising a fiber body (12) containing at least one of cellulose fibers, animal fibers, or synthetic fibers, and supported particles (20) supported on the surface of the fiber body via a binder film (14), wherein the supported particles have a first particle (16) containing a quaternary ammonium salt and a second particle (18) made of a metal oxide capable of reducing iodine, and the binder film contains a silicone-based binder and a urethane-based binder.

2. The fibrous material according to claim 1, wherein the first particle contains a complex or aggregate of the quaternary ammonium salt and an anionic surfactant.

3. The fibrous material according to claim 1, wherein the metal oxide is zinc oxide, titanium oxide, or tin oxide.

4. The fibrous material according to claim 1, wherein the metal oxide is a metal oxide doped with a Group 13 element.

5. The fibrous material according to claim 4, wherein the Group 13 element is aluminum.

6. The fibrous material according to any one of claims 1 to 5, wherein the binder film is a single film composed of a mixture of the silicone-based binder and the urethane-based binder.

7. A method for producing a fibrous material comprising a fiber body containing at least one of cellulose fibers, animal fibers, or synthetic fibers, and supported particles supported on the surface of the fiber body via a binder film, the method comprising: an immersion step (S1) of immersing the fiber body in an aqueous dispersion in an anion-rich state in which a quaternary ammonium salt, a metal oxide capable of reducing iodine, a silicone-based binder, and a urethane-based binder are co-treated; and a heating step (S2) of forming a binder film from the silicone-based binder and the urethane-based binder by heat treatment, wherein in the heating step, the supported particles having a first particle containing the quaternary ammonium salt and a second particle made of the metal oxide are supported on the surface of the fiber body via the binder film to obtain a fibrous material.

8. The method for producing a fibrous material according to claim 7, wherein an anionic surfactant is added to the aqueous dispersion to make the aqueous dispersion an anionic liquid.

9. The method for producing a fibrous material according to claim 8, wherein the sum of the molar concentration of the quaternary ammonium salt and the molar concentration of the anionic surfactant in the aqueous dispersion is 40 to 100 mM, and the molar concentration of the anionic surfactant is at least 4 times the molar concentration of the quaternary ammonium salt.

10. The method for producing a fibrous material according to claim 7, wherein the metal oxide is zinc oxide, titanium oxide, or tin oxide.

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