Antimicrobial composition, medium containing the same, and article

Abstract

To provide a composition that contains an antimicrobial component that sufficiently exhibits antimicrobial activity and has superior persistence and durability.SOLUTION: Provided is an antimicrobial composition comprising at least one antimicrobial component, a cellulose nanofiber, and a silane coupling agent, or an antimicrobial composition comprising at least one compound wherein an antimicrobial component also has performance of a silane coupling agent, and a cellulose nanofiber.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to compositions having antibacterial properties, materials containing the compositions, and articles using them. [Background technology]

[0002] In recent years, growing awareness of cleanliness and the diversification of living environments aimed at comfortable living have led to an increasing demand for functional compositions and materials with antibacterial properties, as well as for products that use them. There are many areas of interest, ranging from textiles such as clothing and sheets used by general consumers and in medical and welfare settings, to floors, walls, and handrails in buildings, and even toys used by infants and young children. Against this social background, various proposals have been made in recent years for functional materials with antibacterial properties.

[0003] As such proposals, Patent Documents 1 and 2 disclose methods using functional materials and nanofibers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-193793 [Patent Document 2] Japanese Patent Application Publication No. 2023-108642 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses a method for supporting a functional material having antibacterial and deodorizing properties and a solvent on the surface of a textile material via nanofibers. However, although this method achieves good support between the textile material surface and the nanofibers, there is still room for improvement in a method for more firmly supporting the functional material having antibacterial and deodorizing properties on the nanofibers and improving the durability of the effects of the functional material so that they last for a longer period of time.

[0006] Furthermore, Patent Document 2 discloses a method of supporting antibacterial components on cellulose nanofibers using an aqueous solution of magnesium chloride or benzalkonium chloride, but there is still room for further study regarding the durability of the antibacterial components.

[0007] Therefore, an object of the present invention is to provide a composition that includes a component having antibacterial properties (hereinafter sometimes abbreviated as antibacterial component, in other words, a substance having antibacterial properties, an antibacterial agent), which fully exhibits such functionality and has excellent long-lasting and durable properties. [Means for solving the problem]

[0008] As a result of extensive research to achieve the above-mentioned objective, the inventors have newly discovered that by supporting the antibacterial component on cellulose nanofibers via a silane coupling agent, the antibacterial properties of the antibacterial component are fully exerted and a composition with excellent durability and long-lasting properties can be obtained, thereby completing the present invention.

[0009] That is, the above object has been achieved by the following means.

[0010] (1) An antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent.

[0011] (2) In the antibacterial composition described in (1) above, it is preferable that the component having antibacterial properties is selected from chlorine-based compounds, cationic compounds, metal-based compounds, metal oxide-based compounds, pyridine-based compounds, phenol-based compounds, and polyphenol-based compounds, and that the content of the component having antibacterial properties is 0.01 to 50 parts by mass per 100 parts by mass of cellulose nanofibers.

[0012] (3) In the antibacterial composition according to the above item (1) or (2), the content of the silane coupling agent is preferably 0.0001 to 5 parts by mass per 100 parts by mass of the cellulose nanofibers.

[0013] (4) The present invention further provides an antibacterial composition containing cellulose nanofibers and at least one compound whose component having antibacterial properties also has the properties of a silane coupling agent.

[0014] (5) In the antibacterial composition described in (4) above, it is preferable that the content of the component having antibacterial properties that also has the performance of a silane coupling agent is 0.01 to 50 parts by mass per 100 parts by mass of cellulose nanofibers.

[0015] (6) The present invention also provides an antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, a silane coupling agent, and a medium that is a solvent and / or dispersion medium for these components.

[0016] (7) Furthermore, the present invention provides an antibacterial composition comprising at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent, cellulose nanofibers, and a medium which is a solvent and / or dispersion medium for these compounds.

[0017] (8) The present invention also provides an article having antibacterial properties, in which an antibacterial composition containing at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent is formed on at least the surface of a solid article.

[0018] (9) Furthermore, the present invention provides an article having antibacterial properties, in which an antibacterial composition containing at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent and cellulose nanofibers is formed on at least the surface of the solid article. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a composition that exhibits good antibacterial activity and is excellent in long-lasting properties and durability, and an article in which the composition is formed on at least a part of the surface of the article and the antibacterial activity is excellent in long-lasting properties and durability. DETAILED DESCRIPTION OF THE INVENTION

[0020] One aspect of the present invention is an antibacterial composition containing at least one antibacterial component, cellulose nanofibers, and a silane coupling agent, or an antibacterial composition containing at least one compound in which the antibacterial component also functions as a silane coupling agent, and cellulose nanofibers. One aspect of the raw material for such an antibacterial composition is an antibacterial composition containing the antibacterial component, cellulose nanofibers, a silane coupling agent, and a solvent and / or dispersion medium for these components, or an antibacterial composition containing at least one compound in which the antibacterial component also functions as a silane coupling agent, cellulose nanofibers, and a solvent and / or dispersion medium for these components. The antibacterial composition can be obtained by removing the solvent and / or dispersion medium from these compositions. The removal of the solvent and / or dispersion medium can be achieved by applying the method described below for forming an antibacterial composition containing a solvent and / or dispersion medium on the surface of a solid article.

[0021] Below, we will explain in more detail the antibacterial composition containing at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent, or the antibacterial composition that serves as a raw material for the antibacterial composition containing at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent and cellulose nanofibers, and the antibacterial composition containing a medium that is a solvent and / or dispersion medium.

[0022] (Antibacterial ingredient) The antibacterial component can be selected from various components having antibacterial properties selected from a group consisting of antibacterial properties, depending on the intended use. In the present invention and this specification, the antibacterial component refers to a component that can reduce the number of bacteria by contacting with the antibacterial component. Examples of bacteria that can be targeted for antibacterial treatment include various types of bacteria that are desirably reduced in various fields such as household products and medical products, such as Staphylococcus aureus and Klebsiella pneumoniae.

[0023] The antibacterial component may be a natural or synthetic substance, an inorganic substance, an organic substance, or an organic-inorganic composite substance. The antibacterial component is not limited to those having only antibacterial properties, but may also have functional properties such as deodorizing properties and antiviral properties in addition to antibacterial properties. Hereinafter, a component having antibacterial properties will be referred to as an antibacterial agent, although some of the examples of antibacterial agents also have deodorizing and antiviral properties.

[0024] Inorganic antibacterial agents include chlorine-based compounds that have a certain antibacterial effect, as well as metals (e.g., copper, silver, gold, platinum, zinc, cobalt, nickel, palladium, aluminum, and combinations thereof), or metal oxide compounds (e.g., compounds that have antibacterial effect due to photocatalytic reaction, such as titanium oxide, zinc oxide, iron oxide, tungsten oxide, strontium titanate, zirconium oxide, and combinations thereof). Examples include oxides containing antibacterial metals such as silver, copper, zinc, and nickel, as well as chlorides, sulfides, iodides, or antibacterial metals or antibacterial metal ions supported on a carrier.

[0025] Specific examples of the carrier include zeolite, clay minerals, calcium silicate, zirconium phosphate, titanium phosphate, calcium phosphate, aluminum phosphate, silica gel, alumina, glass, and activated carbon.

[0026] Examples of organic antibacterial agents include various antibacterial agents such as cationic compounds, phenolic compounds, pyridine compounds, biguanide compounds, nitrile compounds, isothiazolinone compounds, imidazole compounds, organic copper compounds, and organic iodine compounds.

[0027] Natural antibacterial agents include polyphenols such as catechin, acidic and basic polysaccharides such as pectic acid and chitosan, and basic peptides and proteins such as protamine, polylysine, and nisin.

[0028] Examples of chlorine-based compounds include sodium hypochlorite; cationic compounds include polyhexamethylene biguanide, quaternary ammonium salt compounds such as alkylbenzylammonium chloride (benzalkonium chloride) and dimethyldidecylammonium chloride; phenolic compounds include phenol (carbolic acid), 4-isopropyl-3-methylphenol (isopropylmethylphenol (IPMP), Biosol), and 2-isopropyl-5-methylphenol (thymol); pyridine compounds include zinc pyrithione and sodium pyrithione; and polyphenolic compounds include epigallocatechin gallate.

[0029] The ability of the above-mentioned various antibacterial agents to be supported on cellulose nanofibers can be improved appropriately depending on the type of silane coupling agent used.

[0030] In addition, examples of compounds in which the component having antibacterial properties also has the performance of a silane coupling agent (in other words, silane coupling agents having antibacterial properties) include dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and other quaternary ammonium salt silane coupling agents.

[0031] The amount of the antibacterial component is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, and preferably 50 parts by mass or less, more preferably 35 parts by mass or less, even more preferably 20 parts by mass or less, and still more preferably 15 parts by mass or less, per 100 parts by mass of cellulose nanofiber.

[0032] When the antibacterial component is 0.01 parts by mass or more, antibacterial performance is easily exhibited, while when it is 50 parts by mass or less, it can be sufficiently supported on the cellulose nanofiber using a silane coupling agent, and sufficient sustainability and durability can be exhibited, which is preferable.

[0033] (Cellulose nanofiber (hereinafter referred to as CNF) CNF is a highly safe material with moisture-retaining properties, and is a fine cellulose fiber obtained by defibrating pulp fibers. It generally refers to cellulose fibers including cellulose fine fibers with a fiber width (thickness) of nano-size (1 nm or more and 1000 nm or less), but fine fibers with an average fiber width of 100 nm or less are preferred. The average fiber width (thickness) can be calculated, for example, using a certain number of number averages, medians, mode diameters (mode values), etc.

[0034] (Pulp fibers that can be used for CNF) Pulp fibers that can be used as CNFs include, for example, chemical pulps such as hardwood pulp (LBKP) and softwood pulp (NBKP); mechanical pulps such as bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), pressed stone ground pulp (PGW), refiner ground pulp (RGP), chemi-ground pulp (CGP), thermo-ground pulp (TGP), ground pulp (GP), thermomechanical pulp (TMP), chemi-thermomechanical pulp (CTMP), and refiner mechanical pulp (RMP); waste paper pulp produced from used brown paper, kraft envelope paper, magazine paper, newspaper paper, flyer paper, office paper, cardboard paper, white paper, Kent paper, imitation paper, land certificate paper, and recycled paper; and deinked pulp (DIP) obtained by deinking waste paper pulp. These may be used alone or in combination as long as the effects of the present invention are not impaired.

[0035] (CNF defibrillation method) Examples of defibration methods used in the production of CNF include mechanical methods such as high-pressure homogenizer method, microfluidizer method, grinder grinding method, bead mill freeze-pulverization method, and ultrasonic defibration method, but are not limited to these methods.

[0036] CNF that has only been mechanically treated (not modified) using the above-mentioned defibration method, i.e., CNF that has not been modified with functional groups, has higher thermal stability than CNF modified with functional groups such as phosphate groups or carboxymethyl groups, and can therefore be used in a wider range of applications. However, CNF modified with functional groups such as phosphate groups or carboxymethyl groups can also be used in the present invention.

[0037] Furthermore, for example, pulp fibers that have been mechanically defibrated may be subjected to chemical treatment such as carboxymethylation or enzyme treatment. Examples of chemically treated CNF include iCNF (individualized CNF) (single nanocellulose) with a fiber width (thickness) of 3 to 4 nm, such as TEMPO-oxidized CNF, phosphate-esterified CNF, and phosphite-esterified CNF.

[0038] Alternatively, CNF that has been subjected to only chemical or enzymatic treatment, or CNF that has been subjected to chemical or enzymatic treatment and then mechanically defibrated may be used.

[0039] [Carboxymethylcellulose (hereinafter referred to as CMC)] In addition, CMC, a water-soluble polymer, may be added to prevent aggregation of CNF in the solvent and / or dispersion medium.

[0040] When CNF is added to an aqueous solvent, the microfibril fibers of the CNF bond together and aggregate. However, by adding CMC and allowing the CNF and CMC to coexist, the OH groups of the CNF and the OH groups of the CMC form hydrogen bonds, and the electrostatic interaction of the molecular chains and the steric hindrance effect prevent the CNF from aggregating, allowing the CNF to be dispersed uniformly in the solution.

[0041] CMC is preferably used because it is obtained from cellulose, has moderate biodegradability, and can be incinerated after use, making it an extremely environmentally friendly material. However, water-soluble polymers other than CMC may also be used as long as they can prevent aggregation of CNF in solution.

[0042] When CMC is added, it is preferable that the CMC be contained in an amount of 0.1 to 1.0 part when the total amount of the CNF solution obtained by fiber-opening is 100 parts.

[0043] (Hydrophobic CNF) In the present invention, the CNF may be hydrophobized. Hydrophobized CNF refers to CNF with hydrophobic groups introduced onto the surface, and CNF that has been subjected to a hydrophobic surface treatment with a hydrophobizing agent.

[0044] CNF is inherently hydrophilic, but can be made hydrophobic (lipophilic) by introducing hydrophobic groups or by surface treatment with a hydrophobizing agent, allowing it to be uniformly dispersed in organic solvents such as ethyl acetate, butyl acetate, MEK, IPA, cyclohexanone, acetone, ethanol, and other organic solvents that are compatible with these solvents.For this reason, while non-hydrophobized CNF undergoes phase separation or aggregates and becomes cloudy when mixed with an organic solvent, hydrophobized CNF disperses uniformly without becoming cloudy when mixed with an organic solvent.

[0045] Various conventionally known methods can be used for hydrophobizing CNF to make it hydrophobic (lipophilic). Representative methods include the following:

[0046] (1) Some or all of the hydroxyl groups of CNF are substituted with hydrophobic groups by reactions such as esterification (acylation) (alkyl esterification, complex esterification, β-keto esterification, etc.), alkylation, tosylation, epoxidation, arylation, etc. Among these, esterification is preferred, and in the esterified hydrophobic CNF, some or all of the hydroxyl groups of cellulose are acylated with a carboxylic acid such as acetic acid, acetic anhydride, propionic acid, or butyric acid, or a halide (especially a chloride) thereof.

[0047] (2) CNF is modified with carboxy anions by oxidation treatment using N-oxyl compounds such as TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl).Furthermore, CNF is hydrophobized by adding and reacting with organic onium compounds having an onium structure such as organic ammonium or organic phosphonium.

[0048] (3) CNF is surface-treated using one or more hydrophobizing agents selected from the group consisting of silane coupling agents (the silane coupling agents mentioned here are intended to hydrophobize CNF and are used separately from those used to support antibacterial components on CNF), titanate coupling agents, aluminum coupling agents, silicone oils, fluorine oils, silicone resins, fluorine resins, acrylic resins, and inorganic powders treated with these. Of these, silane coupling agents are preferred. Silane coupling agents hydrophobize CNF by undergoing a dehydration condensation reaction with hydroxyl groups on the fiber surface to form strong covalent bonds.

[0049] (4) Metal or ceramic raw materials are surface coated using physical vapor deposition (PVD) methods such as vacuum deposition, ion plating, and sputtering, chemical vapor deposition (CVD), or plating methods such as electroless plating and electrolytic plating, to physically modify the CNF and make it hydrophobic.

[0050] (Silane coupling agent) Examples of silane coupling agents include vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, methacryl silane coupling agents, acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, acid anhydride silane coupling agents, quaternary ammonium salt silane coupling agents, alkylene glycol silane coupling agents, carboxyl silane coupling agents, alkyl silane coupling agents, etc. In the present invention, depending on the compatibility between the antibacterial component and CNF, one selected from these may be used alone, or two or more may be used in combination.

[0051] In the present invention, examples of silane coupling agents that are relatively versatile include vinyl silane coupling agents, epoxy silane coupling agents, methacryl silane coupling agents, acrylic silane coupling agents, amino silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and quaternary ammonium salt silane coupling agents.

[0052] The amount of the silane coupling agent is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, even more preferably 0.001 parts by mass or more, still more preferably 0.005 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, and still more preferably 0.5 parts by mass or less, relative to 100 parts by mass of CNF.

[0053] When the amount is 0.0001 parts by mass or more, a sufficient amount of the antibacterial component can be supported on the CNF, resulting in a sustained and durable effect. On the other hand, when the amount is 5 parts by mass or less, the silane coupling agent is prevented from becoming excessive relative to the CNF, and the antibacterial component can be efficiently supported on the CNF, which is preferable.

[0054] The effects of silane coupling agents for supporting antibacterial components on CNF are expected to be as follows.

[0055] Silane coupling agents are mainly classified into silanol group moieties and organic functional group moieties. Depending on the characteristics of each of these two moieties, one moiety bonds with or electrically attracts the antibacterial component, while the other moiety of the silane coupling agent reacts with or is electrically attracted to the hydroxyl groups of CNF, or the modified part if functional group modified, and the silane coupling agent acts as a bridge between the CNF and the antibacterial component, firmly supporting the antibacterial component on the CNF and contributing to the durability and sustainability of the antibacterial performance.

[0056] The composition according to one embodiment of the present invention may contain additives together with the composition, as long as the effects of the present invention are not impaired.

[0057] Examples of additives include deodorants, insecticides, antifungal agents, mildewcides, antiviral agents, virucides, surfactants, preservatives, antifreezing agents, stabilizers, pH adjusters, wetting agents, dispersants, viscosity control agents, thickeners, antisettling agents, antifoaming agents, leveling agents, light stabilizers, water repellents, oil repellents, hydrophilic agents, antioxidants, pigments, dyes, ultraviolet absorbers, and antistatic agents.

[0058] (medium) The term "medium" refers to a solvent or a dispersion medium, and the term "solvent and / or dispersion medium" includes the case where, when there is no suitable solvent for dissolving the antibacterial agent or CNF, both a solvent for dissolving the silane coupling agent and a dispersion medium for dispersing the antibacterial agent or CNF may be used simultaneously.

[0059] As the medium, one or more solvents or liquid dispersion media selected from the group consisting of water and organic solvents can be used, and further, liquid detergents, fabric softeners, paints and coating agents used for painting, coating, printing, etc., inks, resins before solidification, etc. can also be used.

[0060] For example, examples of organic solvents include alcohols (e.g., methanol, ethanol, isopropyl alcohol, n-butanol, tert-butanol, ethylene glycol, glycerin, etc.), ethers (e.g., ethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), etc. As the solvent or dispersion medium, water alone may be used, or one or more organic solvents may be used, or a mixed solvent or mixed dispersion medium of water and one or more organic solvents may be used.

[0061] Examples of paints as a medium include coating materials for protecting and beautifying objects, and for providing other functions. Examples of coating agents as a medium include coating materials for improving the surface hardness of objects, imparting functions such as stain resistance, water repellency, oil repellency, hydrophilicity, lipophilicity, and anti-reflection, and for imparting adhesive and bonding functions. Furthermore, examples of inks as a medium include those used for printing and printing, as well as materials for dyeing. Additionally, by using a resin before solidification as a medium, it is possible to disperse the composition of the present invention and then solidify it to produce a resin with antibacterial properties.

[0062] The dispersion medium may be a solid dispersion medium, and in addition to liquid coating agents, inks, etc., they may be solids used in hot melt applications, etc. Furthermore, gaseous dispersion media such as aerosols used in sprays can also be used as the medium in the present invention.

[0063] There are no particular restrictions on the medium, as long as it does not cause chemical changes to the object being dissolved or dispersed (i.e., the antibacterial component is not decomposed, or if the antibacterial component contains a metal, the metal is not dissolved in an acid or alkaline solution, and further, the CNF does not aggregate or decompose).

[0064] The amount of solvent or dispersion medium should be adjusted appropriately depending on the intended use, but it is necessary to adjust the amount of solvent or dispersion medium so that the antibacterial component, CNF, and silane coupling agent are sufficiently dispersed and dissolved and mixed uniformly. (Goods) In the present invention, the term "article" refers to solid materials that can be deformed but are not fluid, such as fibers, leather, rubber, plastic films, and paper, as well as solid articles that do not normally deform.

[0065] Specific examples of solid objects that can be deformed but are not fluid include clothes, white coats, aprons, pillows, futons, sheets, towels, handkerchiefs, wet tissues, sofas, cushions, car seats, rugs, carpets, curtains, gloves, boots, plastic film bags and wraps for storing food, tissues, cardboard, and paper packaging materials.

[0066] Specific examples of solid objects that do not normally deform include building materials such as walls, floors, and handrails; operating devices such as multifunction printers, ticket machines, and ATMs; communication devices such as smartphones, tablets, and smartwatches; sanitary products used in water areas such as faucets, showers, and hand washing areas in toilets, kitchens, and bathrooms; home appliances; desks, chairs, straps, and toys.

[0067] The antibacterial composition can be formed on the surface of the article by kneading it into the raw materials in the manufacturing process of the fibers, paper, rubber, plastics, etc., or by washing the article using the fibers after it has been formed using a liquid detergent or fabric softener with antibacterial properties, or by spraying an antibacterial composition made using a liquid or gaseous medium onto the surface of the fiber, paper, rubber, or plastic, thereby exerting the antibacterial effect.

[0068] Furthermore, there are no particular limitations on the method for forming an antibacterial composition on the surface of an article by painting, coating, printing, dyeing, etc. using paint, coating agent, ink, etc., and examples include a manufacturing method having a step of applying the antibacterial composition of the present invention containing the above-mentioned medium to each article to form a coating film, and drying the coating film.

[0069] Examples of methods for applying the antibacterial composition containing the medium of the present invention to an article include spray coating, dipping, spin coating, bar coating, knife coating, roll coating, roll knife coating, blade coating, die coating, and gravure coating, as well as brush coating, roller coating, and mop coating.

[0070] When the resin composition is used for printing, a printing method such as flexographic printing, offset printing, gravure printing, silk screen printing, or ink jet printing can be used on the substrate.

[0071] Furthermore, when a hot melt type medium is used, it can be applied using a device equipped with a melter or applicator.

[0072] After the antibacterial composition containing the medium of the present invention is applied to the target article, it is preferable to carry out drying, curing, aging, etc. depending on the medium. Specifically, the antibacterial composition is formed on the surface of each article through heat drying in an oven or the like, heat curing, moisture curing, light curing, electron beam curing, and an aging period for curing.

[0073] Thus, the present invention can provide an antibacterial article having, on at least the surface of a solid article, an antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent.Furthermore, the present invention can provide an antibacterial article having, on at least the surface of a solid article, an antibacterial composition comprising at least one compound whose antibacterial properties also function as a silane coupling agent and cellulose nanofibers.

[0074] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. There is no.

[0075] (Preparation of copper nanoparticle dispersion) An example of a method for producing copper nanoparticles is shown below. (1) A first aqueous solution containing 0.1 mol / L of copper ions and 0.6 mol / L of citric acid and adjusted to pH 11 was prepared. (2) A second aqueous solution was prepared with an ascorbic acid concentration of 0.6 mol / L and adjusted to a pH of 11. Since the first aqueous solution was set to a pH of 11, the second aqueous solution was also set to a pH of 11. (3) The first aqueous solution and the second aqueous solution were each heated to 70°C and mixed, followed by stirring at 70°C for 60 minutes. As a result, a dispersion of copper nanoparticles was obtained.

[0076] (Preparation of silver nanoparticle dispersion) An example of a method for producing silver nanoparticles is shown below.

[0077] 1.0 g of silver oxide (average particle size 1.5 μm) and 1.0 g of soluble starch were added to 98 g of distilled water. The mixture was then heated at 60°C for 1 hour while stirring. The solution initially appeared black due to the suspended silver oxide, but as the reduction reaction progressed, it turned yellow and eventually yellowish-brown, confirming the formation of silver. A portion of the solution was diluted with distilled water and observed under an electron microscope, revealing that silver nanoparticles with particle sizes of 10-30 nm had been obtained. In this way, a silver nanoparticle dispersion was prepared.

[0078] The concentrations of the obtained copper nanoparticles and silver nanoparticles were measured using a high-frequency inductively coupled plasma optical emission spectrometer (ICP) (SPECTRO ARCOS FHM22 manufactured by SPECTRO Analytical Instruments).

[0079] (Preparation 1) [3-(2-aminoethylamino)propyl]trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a silane coupling agent, and 1 part by mass of the silane coupling agent was dissolved in 99 parts by mass of isopropyl alcohol to obtain a 1% by mass solution.

[0080] (Preparation 2) As a silane coupling agent with antibacterial properties, 2.5 parts by mass of a 40% by mass solution of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 97.5 parts by mass of purified water to obtain a 1% by mass solution of a quaternary ammonium salt silane coupling agent.

[0081] (Preparation 3) 0.01 parts by mass of the 1% by mass solution obtained in Preparation 1 was added to 100.2 parts by mass (100.2 g) of the copper nanoparticle dispersion (copper content: 0.1 g, 99.8 ppm) and stirred for 1 minute with a stirrer (copper: 0.1 g, silane coupling agent: 0.0001 g). (Preparation 4) 0.01 parts by mass of the 1% by mass solution obtained in Preparation 1 was added to 164.2 parts by mass (164.2 g) of the silver nanoparticle dispersion (silver content: 0.1 g, 60.9 ppm), and the mixture was stirred for 1 minute with a stirrer (silver: 0.1 g, silane coupling agent: 0.0001 g). [Example]

[0082] 50 parts by mass of CNF (2% by mass aqueous dispersion) (BiNFi-S manufactured by Sugino Machine) prepared by mechanical pulverization (1 g of CNF) was added to 500 parts by mass of purified water and stirred for 30 minutes. Then, 10 parts by mass of the solution obtained in Preparation 3 (0.01 g of copper, 0.00001 g of silane coupling agent) was added, and the mixture was further stirred and mixed for 5 minutes to obtain a composition. [Example]

[0083] 50 parts by mass of CNF (2% by mass aqueous dispersion) (BiNFi-S manufactured by Sugino Machine) prepared by mechanical pulverization (1 g of CNF) was added to 500 parts by mass of purified water and stirred for 30 minutes. Then, 10 parts by mass of the solution obtained in Preparation 4 (0.01 g of silver, 0.00001 g of silane coupling agent) was added, and the mixture was further stirred and mixed for 5 minutes to obtain a composition. [Example]

[0084] 50 parts by mass (1 g of CNF) of mechanically pulverized CNF (2% by mass aqueous dispersion) (BiNFi-S manufactured by Sugino Machine) was added to 500 parts by mass of purified water and stirred for 30 minutes. Then, 1 part by mass (0.01 g of quaternary ammonium salt) of the solution obtained in Preparation 2 was added, and the mixture was further stirred and mixed for 5 minutes to obtain a composition. [Comparative Example 1]

[0085] 50 parts by mass (1 g of CNF) of CNF (2% by mass aqueous dispersion) (BiNFi-S manufactured by Sugino Machine Co., Ltd.) prepared by mechanical pulverization was added to 500 parts by mass of purified water and stirred for 30 minutes. Then, 10 parts by mass (0.01 g of copper) of the solution obtained by preparing the copper nanoparticle dispersion was added, and the mixture was further stirred and mixed for 5 minutes to obtain a composition.

[0086] Next, 3.3 parts by mass of magnesium chloride was added thereto as an auxiliary agent, and the mixture was stirred and mixed for 5 minutes to obtain a composition. Comparative Example 2

[0087] 50 parts by mass (1 g of CNF) of CNF (2% by mass aqueous dispersion) (BiNFi-S manufactured by Sugino Machine) prepared by mechanical pulverization was added to 500 parts by mass of purified water and stirred for 30 minutes. Then, 16.4 parts by mass (0.01 g of silver) of the solution obtained by preparing the silver nanoparticle dispersion was added, and the mixture was further stirred and mixed for 5 minutes to obtain a composition.

[0088] Next, 10 parts by mass of an aqueous solution of benzalkonium chloride (10% solution) was added as an adjuvant, and the mixture was stirred and mixed for 5 minutes to obtain a composition.

[0089] (Preparation of test samples using each composition) Treated polyester fibers were produced by immersing 5 g of polyester fibers in the diluted solutions of the respective compositions prepared in Examples 1 to 3 and Comparative Examples 1 and 2 for 30 seconds, taking out the fibers, and drying them at 120°C for 10 minutes. The polyester fiber treated with the diluted solution of Example 1 was used as Example 4. The polyester fiber treated with the diluted solution of Example 2 was used as Example 5. The polyester fiber treated with the diluted solution of Example 3 was used as Example 6. The polyester fiber treated with the diluted solution of the composition of Comparative Example 1 was used as Comparative Example 3. The polyester fiber treated with the diluted solution having the composition of Comparative Example 2 was designated as Comparative Example 4. (Antibacterial evaluation) The obtained fibers were subjected to the following durability and antibacterial activity tests, and the antibacterial activity was evaluated in accordance with JIS L1902. The evaluation was carried out based on the antibacterial activity value calculated by the following method. The results are shown in Table 1.

[0090] (Sustainability and durability test) The fibers obtained in Examples 4 to 6 and Comparative Examples 3 and 4 were evaluated, as were the fibers after washing them 10 times and 15 times in a household washing machine (model number ES-KSV9E-N, manufactured by Sharp, standard cycle, detergent: JAFET standard blend detergent).

[0091] (Bacteria used) Staphylococcus aureus (Calculation of viable bacteria count) 0.2 mL of the inoculum was added to the above-mentioned fiber, which was then placed in a sterile vial and sealed. The vial was left standing at 37°C for 24 hours to serve as the sensitization period. After the sensitization period had elapsed, 20 mL of washout saline was added to the vial and mixed thoroughly to wash out the bacteria. The viable bacterial count of the washout solution was calculated using the pour plate culture method.

[0092] The antibacterial activity value was calculated using the following formula. (logA1-logA0)-(logB1-logB0) log A1: Common logarithm of the number of viable bacteria in untreated fiber after incubation logA0: Common logarithm of the number of viable bacteria on untreated fiber immediately after inoculation logB1: Common logarithm of the number of viable bacteria on the treated fiber after incubation logB0: Common logarithm of the number of viable bacteria on the treated fiber immediately after inoculation

[0093] [Table 1] As shown in Table 1, the polyester fibers treated with the compositions of the present invention (Examples 4 to 6) exhibited antibacterial properties that were excellent in long-lasting and durability.

[0094] On the other hand, in Comparative Examples 3 and 4, the antibacterial properties were lost after repeated washing, resulting in poor durability. [Industrial Applicability]

[0095] The compositions of the present invention have excellent long-lasting and durable antibacterial properties and can be used on a variety of items. For example, the antibacterial compositions of the present invention containing a vehicle can be used in laundry using liquid detergents or fabric softeners as the vehicle, or can be sprayed as an aerosol using a gas as the vehicle, effectively applying the present invention to everyday clothing, bedding, and other sheets, as well as clothing and sheets used in medical and welfare settings. Furthermore, by incorporating the antibacterial compositions of the present invention containing a vehicle into paints, coatings, inks, etc., they can be used as long-lasting and durable antibacterial surface treatment materials for floors and walls of homes and public facilities. Furthermore, by incorporating the compositions into resins, the compositions contribute to the long-lasting and durable antibacterial effect of the resin materials themselves, enabling their use in home appliances and toys. Furthermore, by incorporating the compositions into coatings for metals, glass, resins, etc., they can be used on plumbing products such as faucets, showers, and hand-washing areas in toilets, bathrooms, and kitchens, as well as communication devices such as smartphones, tablets, and smartwatches, and operating terminals such as multifunction printers, ticket machines, and ATMs, thereby providing long-lasting and durable antibacterial effects.

Claims

1. An antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent.

2. The composition according to claim 1, wherein the component having antibacterial properties is selected from a chlorine-based compound, a cationic compound, a metal-based compound, a metal oxide-based compound, a pyridine-based compound, a phenol-based compound, and a polyphenol-based compound, and the content of the component having antibacterial properties is 0.01 to 50 parts by mass per 100 parts by mass of cellulose nanofiber.

3. The composition according to claim 1 or claim 2, characterized in that the content of the silane coupling agent is 0.0001 to 5 parts by mass per 100 parts by mass of cellulose nanofibers.

4. An antibacterial composition comprising at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent, and cellulose nanofibers.

5. The composition according to claim 4, characterized in that the content of the component having antibacterial properties and also having the performance of a silane coupling agent is 0.01 to 50 parts by mass per 100 parts by mass of cellulose nanofibers.

6. An antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, a silane coupling agent, and a medium which is a solvent and / or dispersion medium for these components.

7. An antibacterial composition comprising at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent, cellulose nanofibers, and a medium which is a solvent and / or dispersion medium for these.

8. An article having antibacterial properties, comprising an antibacterial composition formed on at least the surface of a solid article, the antibacterial composition comprising at least one component having antibacterial properties, cellulose nanofibers, and a silane coupling agent.

9. An article having antibacterial properties, in which an antibacterial composition containing at least one compound whose component having antibacterial properties also has the performance of a silane coupling agent and cellulose nanofibers is formed on at least the surface of a solid article.

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