Composition for controlling microorganisms, bactericide and antibacterial agent, and microorganism control material

Abstract

Provided are a microbial control composition having an excellent microbial control effect, a bactericide and an antibacterial agent containing the composition, and a microbial control material. 【Solution means】The microbial control composition of the present invention contains graphene oxide and a fluorine component. Further, in the microbial control material of the present invention, graphene oxide and a fluorine component are supported on a substrate. The microbial control composition and the microbial control material of the present invention have an excellent microbial control effect and are suitable as a bactericide or an antibacterial agent.

Description

Technical Field

[0001] The present invention relates to a composition for controlling microorganisms, a bactericide and an antibacterial agent, and a microorganism control material.

Background Art

[0002] Conventionally, various antibacterial agents and bactericides have been applied to various articles such as household goods, industrial products, medical instruments, and building materials in order to prevent the growth of harmful microorganisms (for example, fungi, bacteria, molds, etc.). From this perspective, newly developing a composition for controlling microorganisms that can enhance the performance of antibacterial agents and bactericides is extremely important for improving hygiene.

[0003] For example, Patent Document 1 proposes a bactericide composed of a porous carbon material. Such a bactericide is said to be able to provide excellent deodorizing and bactericidal effects.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, since the demands regarding hygiene have been increasing more and more, it is strongly desired to develop a novel and easily manufacturable bactericide or antibacterial agent.

[0006] The present invention has been made in view of the above, and an object thereof is to provide a composition for controlling microorganisms having an excellent microorganism control action, a bactericide and an antibacterial agent containing the composition, and a microorganism control material.

Means for Solving the Problems

[0007] As a result of intensive research to achieve the above object, the present inventors have found that the above object can be achieved by containing graphene oxide and a fluorine component, and have completed the present invention.

[0008] That is, the present invention includes, for example, the subjects described in the following items. Item 1 A composition for controlling microorganisms, containing graphene oxide and a fluorine component. Item 2 The composition for controlling microorganisms according to Item 1, further containing a dispersion medium. Item 3 The composition for controlling microorganisms according to Item 1, which is in powder form. Item 4 The composition for controlling microorganisms according to Item 1, which is in paste form. Item 5 The composition for controlling microorganisms according to any one of Items 1 to 4, which is for sterilization or antibacterial use. Item 6 A bactericide containing the composition for controlling microorganisms according to any one of Items 1 to 4. Item 7 An antibacterial agent containing the composition for controlling microorganisms according to any one of Items 1 to 4. Item 8 A microorganism control material in which graphene oxide and a fluorine component are supported on a substrate. Item 9 A method for controlling microorganisms using the composition for controlling microorganisms according to any one of Items 1 to 5.

Effects of the Invention

[0009] The composition for controlling microorganisms of the present invention has an excellent microorganism control effect and can be easily produced.

Brief Description of the Drawings

[0010]

Figure 1

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Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail. In this specification, with regard to the expressions "containing" and "comprising", the concepts of "containing", "comprising", "substantially consisting of", and "consisting only of" are included.

[0012] In the numerical ranges described step by step in this specification, the upper limit value or lower limit value of the numerical range at a certain step can be arbitrarily combined with the upper limit value or lower limit value of the numerical range at other steps. In the numerical ranges described in this specification, the upper limit value or lower limit value of the numerical range may be replaced with the value shown in the examples or a value uniquely derivable from the examples. Further, in this specification, the numerical values connected by "~" mean a numerical range including the numerical values before and after "~" as the lower limit value and the upper limit value.

[0013] 1. Composition for controlling microorganisms The composition for controlling microorganisms of the present invention contains graphene oxide and a fluorine component. In the composition for controlling microorganisms of the present invention, graphene oxide and the fluorine component are components (active ingredients) that can exhibit a microorganism control effect.

[0014] The composition for controlling microorganisms of the present invention has an excellent microorganism control effect and can be easily produced. Therefore, the composition for controlling microorganisms of the present invention can be suitably used as a bactericide or an antibacterial agent.

[0015] In the present invention, the "microorganism control action" refers to an action of suppressing the function of microorganisms by preventing the growth of microorganisms, preventing the adhesion of microorganisms, sterilizing, etc. The effects obtained by microorganism control are deodorization, disinfection, sterilization, antibacterial, antifungal, and anti-mold, etc. In this specification, these effects are collectively referred to as the "microorganism control action".

[0016] (Graphene oxide) The composition for microorganism control of the present invention contains graphene oxide as an essential component.

[0017] The type of graphene oxide (generally denoted as GO) is not particularly limited. For example, various known graphene oxides can be used. The graphene oxide may be a reduced graphene oxide so-called "rGO".

[0018] Graphene oxide can be obtained by various production methods or can also be obtained from commercially available products. In particular, in the composition for microorganism control of the present invention, it is preferable that the graphene oxide is produced by an electrolysis method (also referred to as an electrochemical oxidation method). In this case, the composition for microorganism control of the present invention is advantageous in that the microorganism control action is likely to be enhanced, the production of graphene oxide is easier, and in addition, the above-mentioned fluorine component can sometimes be obtained at the same time.

[0019] When obtaining graphene oxide by an electrolysis method, the method is not particularly limited. For example, a known electrolysis method can be widely adopted. When producing graphene oxide by an electrolysis method, a device equipped with at least a power source, an electrolytic solution, and electrodes (an anode and a cathode) can be used. The power source can be, for example, a known power source conventionally used in the electrolysis method, which can also be adopted in the present invention.

[0020] As the anode, a graphite sheet can be used, and in addition, SiC can be used as the anode. As the cathode, metal electrodes such as stainless steel, platinum (Pt) electrodes, and gold electrodes; carbon electrodes such as graphite; etc. can be mentioned. In addition, electrodes in which platinum, gold, etc. are coated on highly corrosion-resistant metals (such as titanium, tantalum, niobium, etc.) can also be mentioned. Among them, it is preferable to use a platinum electrode or stainless steel as the cathode.

[0021] There are no restrictions on the shape, size, etc. of the electrodes. For example, they can be in the same form as the electrodes used in known electrolysis methods.

[0022] Examples of the electrolytic solution include various inorganic acids, organic acids, inorganic salts, and bases. Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, phosphoric acid, hydrofluoboric acid, etc. Examples of organic acids include succinic acid, citric acid, tartaric acid, diacetyl tartaric acid, malic acid, adipic acid, glutaric acid, maleic acid, fumaric acid. Examples of inorganic salts include sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, etc.

[0023] The electrolytic solution is preferably one or more selected from the group consisting of a fluorine-containing compound and sulfuric acid (concentrated sulfuric acid or dilute sulfuric acid), and more preferably a fluorine-containing compound. This is because in this case, the fluorine component can be obtained simultaneously with graphene oxide. Examples of the fluorine-containing compound include the above-mentioned hydrofluoboric acid, sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, etc.

[0024] Examples of the solvent contained in the electrolytic solution include water. Various types of water such as distilled water, tap water, industrial water, ion-exchanged water, deionized water, pure water, and electrolyzed water can be used. The water may contain other solvents and additives as necessary.

[0025] The concentration of the electrolytic solution is not particularly limited. For example, in terms of easily obtaining graphene oxide efficiently, the concentration of the electrolytic solution is preferably 1 mM to 6 M, more preferably 0.5 M to 5.5 M, and even more preferably 1 M to 5 M.

[0026] The conditions for producing graphene oxide by the electrolysis method are not particularly limited. For example, the temperature of the electrolytic solution can be -5 to 70 °C, more preferably -5 to 60 °C, and even more preferably 0 to 50 °C. The applied voltage is preferably, for example, 1 to 100 V, more preferably 1 to 80 V, and particularly preferably 1 to 50 V. The positions where the anode and cathode are arranged are also not particularly limited, and for example, they can be the same as those in known electrolysis methods.

[0027] By the above electrolysis, graphene oxide is generated, for example, in a sheet-like shape. After squeezing the electrolytic solution after electrolysis, graphene oxide can be exfoliated or dispersed by performing a washing treatment and / or an ultrasonic treatment as necessary, whereby a graphene oxide dispersion can be obtained.

[0028] By the above electrolysis method, graphene oxide, which is an essential component of the composition for controlling microorganisms of the present invention, can be obtained. In addition, graphene oxide can also be produced using, for example, the method disclosed in International Publication No. 2020 / 105646.

[0029] The shape of graphene oxide is not particularly limited, and for example, it can be sheet-like, flake-like, particulate, etc., and is preferably sheet-like. Graphene oxide may be monolayer or multilayer, and when producing graphene oxide by the above electrolysis method, it is likely to be in a sheet-like shape having a single-layer to multilayer structure.

[0030] The size of the graphene oxide is not particularly limited, and for example, it can be the same size as the graphene oxide obtained by the conventional electrolysis method. For example, the size of the graphene oxide measured from the image observed by a scanning electron microscope is 10 nm to 50 μm, preferably about 100 nm to 20 μm. When the graphene oxide is produced by the above electrolysis method, the size of the graphene oxide is likely to be within these ranges. The size of the graphene oxide can mean the average value obtained by measuring the equivalent circle diameters of 50 randomly selected particles from the image observed by a scanning electron microscope with a caliper. When the graphene oxide is in the form of a sheet, flake, etc., for example, its thickness is about 1 nm to 50 nm.

[0031] In the graphene oxide, the oxygen content is not particularly limited, and for example, it can have the same oxygen content as known graphene oxide. For example, in terms of being likely to improve the microbial control performance, the oxygen content of the graphene oxide is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, based on the total amount of the graphene oxide and the fluorine component contained in the microbial control composition of the present invention. The oxygen content of the graphene oxide can be quantified by elemental analysis using EDS (energy dispersive X-ray spectroscopy).

[0032] The graphene oxide may contain a fluorine component. Such a fluorine component can be contained in the graphene oxide, for example, by being mixed or generated during the production process of the graphene oxide. When the fluorine component is contained in the graphene oxide, the fluorine component can also be used as the fluorine component in the microbial control composition of the present invention. In particular, in the above electrolysis method, when an electrolytic solution containing a fluorine-containing compound is used, graphene oxide containing a fluorine component is likely to be obtained.

[0033] It should be noted that the graphene oxide may unavoidably contain, for example, graphite as a raw material.

[0034] When the graphene oxide is the aforementioned reduced graphene oxide, the method for producing such reduced graphene oxide is not particularly limited, and for example, a known method for producing reduced graphene oxide can be widely adopted.

[0035] (Fluorine component) The composition for controlling microorganisms of the present invention contains a fluorine component as an essential component. When the composition for controlling microorganisms of the present invention does not contain a fluorine component, the performance of graphene oxide in controlling microorganisms cannot be exerted.

[0036] The fluorine component may be either fluorine alone or a fluorine compound. The fluorine component may be a fluorine ion.

[0037] As described above, when graphene oxide is produced by an electrolysis method using an electrolytic solution containing a compound containing fluorine, the fluorine component contained in the composition for controlling microorganisms is derived from the compound or mixture containing the fluorine.

[0038] In the composition for controlling microorganisms of the present invention, the fluorine component can exist independently of graphene oxide, or can exist by being physically or chemically bonded to graphene oxide.

[0039] Specifically, the fluorine component can form a composite structure with graphene oxide by chemical bonds or physical bonds such as ionic bonds, covalent bonds, hydrogen bonds, and intercalation. In particular, when graphene oxide is produced by an electrolysis method using an electrolytic solution containing a compound containing fluorine, the fluorine component is likely to form a composite structure with graphene oxide.

[0040] In the composition for controlling microorganisms of the present invention, the fluorine component may be inevitably contained in a production process such as an electrolysis method as described above, or the fluorine component may be separately added to the composition for controlling microorganisms.

[0041] In the composition for controlling microorganisms of the present invention, the fluorine content is not particularly limited. For example, in terms of the ease of improving the microorganism control performance, the fluorine content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, particularly preferably 1.5% by mass or more, based on the total amount of graphene oxide and fluorine components contained in the composition for controlling microorganisms of the present invention, and is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 4% by mass or less. The fluorine content can be quantified by elemental analysis using EDS (energy dispersive X-ray spectroscopy).

[0042] (Composition for controlling microorganisms) The composition for controlling microorganisms of the present invention can contain a dispersion medium as needed. Examples of the dispersion medium include various solvents, for example, the solvents contained in conventional compositions for controlling microorganisms can be mentioned. Examples of the dispersion medium include water, lower alcohols (for example, alcohols having 1 to 3 carbon atoms), and mixed solvents thereof. A preferred dispersion medium is water.

[0043] When the composition for controlling microorganisms of the present invention further contains a dispersion medium such as water, the composition for controlling microorganisms of the present invention becomes a dispersion liquid in which graphene oxide is dispersed in the dispersion medium. When the composition for controlling microorganisms of the present invention is a dispersion liquid, the solid content concentration is not particularly limited, and in terms of the ease of exhibiting the microorganism control performance, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 2% by mass or less. Note that the solid content means components other than volatile components such as the dispersion medium, and in particular, it can mean what becomes a solid when the dispersion medium is removed.

[0044] The composition for controlling microorganisms of the present invention can also have a form other than a dispersion liquid. For example, it can be in a powder form or in a paste form. When the composition for controlling microorganisms of the present invention is in a powder form or a paste form, for example, a powdery composition for controlling microorganisms can be obtained by the method of removing the dispersion medium of the aforementioned dispersion liquid.

[0045] The composition for controlling microorganisms of the present invention can contain other additives in addition to the aforementioned dispersion medium. For example, it can contain various additives contained in conventional compositions for controlling microorganisms. In the composition for controlling microorganisms of the present invention, the content ratios of graphene oxide and fluorine component are preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more based on the total mass of the composition for controlling microorganisms of the present invention excluding the dispersion medium. The composition for controlling microorganisms of the present invention may be such that the components other than the dispersion medium consist only of graphene oxide and fluorine component.

[0046] The composition for controlling microorganisms of the present invention contains a fluorine component. However, since the content of the fluorine component is correlated with the conductivity of the composition for controlling microorganisms of the present invention, it is preferable that the conductivity of the composition for controlling microorganisms of the present invention is also within a predetermined range.

[0047] From this viewpoint, the conductivity (mS / cm) of the composition for controlling microorganisms of the present invention is preferably 180 mS / cm or more, more preferably 200 mS / cm or more, still more preferably 250 mS / cm or more, and particularly preferably 300 mS / cm or more. The upper limit of the conductivity of the composition for controlling microorganisms of the present invention is not particularly limited. For example, from a practical viewpoint, it is preferably 10000 mS / cm or less, and more preferably 2000 mS / cm or less. The conductivity referred to in the present invention means a value measured with an aqueous dispersion having a solid content concentration of 2% by mass (±0.1%). A commercially available conductivity meter can be used for the measurement.

[0048] When the composition for controlling microorganisms of the present invention is in a solid form such as powder and is prepared from an aqueous dispersion dispersed in an aqueous dispersion medium, it is preferably prepared from an aqueous dispersion within the above conductivity range.

[0049] The method for preparing the composition for controlling microorganisms of the present invention is not particularly limited, and various methods can be widely adopted. For example, in the case where graphene oxide is produced by the above-described electrolysis method and the produced graphene oxide contains a fluorine component, the dispersion of graphene oxide obtained by the electrolysis method can be obtained as the composition for controlling microorganisms of the present invention.

[0050] The composition for controlling microorganisms of the present invention can exhibit excellent microorganism control performance. In particular, it can kill various microorganisms or prevent their growth. Therefore, the composition for controlling microorganisms of the present invention can be suitably used for sterilization or antibacterial purposes.

[0051] That is, the composition for controlling microorganisms of the present invention can be suitably used as an active ingredient of a bactericide or an antibacterial agent. By containing the composition for controlling microorganisms of the present invention, the bactericide can exhibit excellent bactericidal action, and the antibacterial agent can exhibit excellent bactericidal action by containing the composition for controlling microorganisms of the present invention.

[0052] Bactericides and antibacterial agents can exhibit bactericidal and antibacterial actions against harmful microorganisms (e.g., fungi, bacteria, molds, etc.) on various articles such as household goods, industrial products, medical instruments, and building materials. Microorganisms are, for example, fungi, bacteria, molds, etc., and among them, the composition for controlling microorganisms of the present invention can exhibit excellent action against aerobic symbiotic bacteria such as Escherichia coli and Staphylococcus aureus.

[0053] The method for controlling microorganisms using the composition for controlling microorganisms of the present invention is not particularly limited, and various methods can be adopted according to its form. For example, microorganisms can be controlled by the same method as a known method.

[0054] 2. Microorganism control material The present invention also includes a microorganism control material in which graphene oxide and a fluorine component are supported on a substrate. In such a microorganism control material, the graphene oxide and the fluorine component are the same as those contained in the microorganism control composition of the present invention.

[0055] The type of the substrate is not particularly limited, and examples thereof include fibrous substrates such as woven fabrics or non-woven fabrics, and various substrates such as resin substrates, inorganic substrates, wood, and metal substrates.

[0056] The method for producing the microorganism control material is not particularly limited. For example, the microorganism control material can be obtained by bringing the microorganism control composition of the present invention into contact with the substrate. Preferably, a microorganism control material is produced by preparing a microorganism control composition in a dispersed liquid state and bringing such a dispersion into contact with the substrate. In this case, the dispersion preferably has a conductivity within the above-described range.

[0057] In identifying the inventions included in the present disclosure, each configuration (properties, structure, functions, etc.) described in each embodiment of the present disclosure may be combined in any manner. That is, the present disclosure includes all the subjects composed of any combinations of the configurable components described in this specification.

Examples

[0058] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the embodiments of these examples.

[0059] (Production Example 1) A graphite sheet as the anode and a platinum electrode as the cathode were placed in a container filled with an electrolyte solution, and these electrodes were connected to a power source. Electrolysis was carried out by applying a voltage of 5 V between the electrodes while maintaining the electrolyte solution at 30 °C. As the electrolyte solution, an aqueous solution of tetrafluoroboric acid with a concentration of 4.3 M was used. After such electrolysis was completed, the electrolyte solution was concentrated, washed, and dispersed to obtain an aqueous dispersion of graphene oxide having a solid content concentration of 1.98 mass%. The conductivity of the aqueous dispersion of graphene oxide was 313 mS / cm.

[0060] (Production Example 2) The graphene oxide obtained in Production Example 1 was purified. Specifically, the aqueous dispersion of graphene oxide obtained in Production Example 1 was diluted to 0.5 mass%, and 50 mL of it was centrifuged (10,000 rpm, 10 minutes). After that, the supernatant was removed, water was added to the obtained solid matter, and the operation of centrifuging again was repeated 4 times. Dialysis (1000 mL, 4 days) of the aqueous dispersion of graphene oxide (0.5 mass% concentration) obtained by this centrifugation was carried out, followed by centrifugation (10,000 rpm, 10 minutes), and then dialysis was carried out again. The obtained dispersion of graphene oxide (pH was 5.1) was freeze-dried to obtain a solid matter of graphene oxide. As a result of EDS analysis, fluorine was not detected in such a solid matter of graphene oxide.

[0061] (Analysis of Graphene Oxide) Figure 1 shows the XRD analysis results of powdery graphene oxide obtained from the aqueous dispersion of graphene oxide obtained in Production Example 1. From this analysis result, the formation of graphene oxide was confirmed.

[0062] Figure 2 shows the measurement results of AFM (Atomic Force Microscope) observation of the graphene oxide obtained in Production Example 1. The sample for AFM analysis was prepared by dropping a test solution obtained by diluting the graphene oxide dispersion obtained in Production Example 1 20 times onto mica and then drying it. As a result of AFM observation, it was confirmed that the thickness of the graphene oxide obtained in Production Example 1 was 1 nm to several tens of nm.

[0063] Figure 3 is an SEM image of the graphene oxide obtained in Production Example 1. The sample for SEM was prepared by spin-coating the aqueous dispersion obtained in Production Example 1. From this analysis result, it was found that the graphene oxide obtained in Production Example 1 was in a form in which single-layer to multi-layer graphene oxides were aggregated, and it was also confirmed that the size of the graphene oxide was about 5 μm.

[0064] Figure 4 shows the EDS analysis results of the graphene oxide obtained in Production Example 1. Note that Fig. 4(a) shows the SEM image of graphene oxide, (b) shows the carbon distribution, (c) shows the oxygen distribution, and (d) shows the fluorine distribution. The sample for EDS analysis was obtained by producing a powder by freeze-drying the graphene oxide dispersion.

[0065] Table 1 summarizes the results of the EDS analysis, and it was confirmed that F was contained in a predetermined ratio in the graphene oxide.

[0066] Therefore, it was found that the graphene oxide dispersion obtained in Production Example 1 was a composition containing graphene oxide and fluorine (fluorine component). Also, from the results of the EDS analysis, it was found that the degree of oxidation of the graphene oxide was 1.92. In this specification, the degree of oxidation can mean the value of "carbon content ratio / oxygen content ratio".

[0067] [Table 1]

[0068] (Example 1) The dispersion of graphene oxide obtained in Production Example 1 (containing fluorine) was used as a composition for controlling microorganisms.

[0069] (Comparative Example 1) Using the graphene oxide without fluorine obtained in Production Example 2 (that is, purified graphene oxide), a 0.36 mass% concentration graphene oxide dispersion (containing fluorine) was used as a composition for controlling microorganisms.

[0070] (Preparation of MHA Medium) An MHA medium (agar medium, Mueller - Hinton agar) was prepared with a composition consisting of the following component ratios. It was sterilized at 121 °C for 15 minutes by autoclaving and stored at 57 °C to obtain the MHA medium. - Ultra - pure water: 500 mL - Starch: 0.75 g - Beef extract: 1 g - Casein acid hydrolysate: 8.7 g - Agar: 1.7% (8.5 g) - NaOH: 850 μL

[0071] (Test Example 1A) The microbial control composition (aqueous dispersion containing graphene oxide and fluorine component) obtained in Example 1 was stirred and dispersed in a vortex mixer in advance, and then 1 mL, 2 mL, and 3 mL were respectively collected. To each microbial control composition, 500 μL of the bacterium Escherichia coli (hereinafter referred to as E.coli, 10 6 CFU) and 0.9% NaCl aqueous solution were added to make a total volume of 5 mL, and mixed with a vortex mixer to obtain test solutions. Then, these test solutions were cultured at 37 °C for 24 hours while being shaken and stirred at a rotational speed of 160 rpm in a shaking incubator. After the culture was completed, they were stirred with a vortex mixer, and then 100 μL was collected with a pipette and dropped onto the MHA medium and spread with a spreader. Then, they were cultured at 37 °C for 12 hours in a thermostat, and then colony counting was performed.

[0072] (Test Example 1a; Control) 500 μL of the bacterium Escherichia coli (hereinafter referred to as E.coli solution, 10 6Add CFU) and 0.9% NaCl aqueous solution to make a total volume of 5 mL, mix with a vortex mixer to obtain a test solution. Such a test solution was held at 37 °C for 24 hours while shaking and stirring at a rotational speed of 160 rpm with a shaking incubator. Then, after stirring the test solution with a vortex mixer, 100 μL was collected with a pipette, dropped onto an MHA medium, and spread with a spreader. Then, it was cultured at 37 °C for 12 hours in a thermostat, and colony counting was performed during or after the culture.

[0073] (Results of Test Example 1A) Figure 5 shows the results of Test Example 1A, where the horizontal axis of the graph represents the amount of the graphene oxide dispersion used, and the vertical axis represents the killing rate of E. coli.

[0074] From these results, it was shown that the graphene oxide dispersion obtained in Production Example 1 has a bactericidal effect on E. coli. Therefore, it was demonstrated that the microbial control composition containing graphene oxide and a fluorine component has a bactericidal effect.

[0075] (Test Example 1B (Comparison)) Cultivation was carried out in the same manner as in Test Example 1A except that the microbial control composition obtained in Comparative Example 1 was used instead of the microbial control composition obtained in Example 1.

[0076] (Test Example 1b (Control)) Add 500 μL of E. coli solution and 0.9% NaCl aqueous solution to make a total volume of 5 mL, mix with a vortex mixer to obtain a test solution. Such a test solution was held at 37 °C for 24 hours while shaking and stirring at a rotational speed of 160 rpm with a shaking incubator. Then, after stirring the test solution with a vortex mixer, 100 μL was collected with a pipette, dropped onto an MHA medium, and spread with a spreader. Then, it was cultured at 37 °C for 12 hours in a thermostat.

[0077] (Results of Test Example 1B) As for the results of Test Example 1B, no clear decrease in bacteria was confirmed. That is, it can be said that when the fluorine-containing graphene oxide dispersion (stock solution) is purified to remove the fluorine component, the microbial control performance is not exhibited.

[0078] Figure 6 is a photograph showing the state of the medium after culturing in Test Example 1A, Test Example 1a, Test Example 1B, and Test Example 1a, and compares the state of the medium for each amount of use of the microbial control composition. In Test Example 1A (1 mL, 2 mL, and 3 mL of Example 1), a clear decrease in bacteria was visually confirmed, whereas in Test Example 1B (Comparative Example 1), no decrease in bacteria was observed, which can also be judged from this photograph.

[0079] (Production Example 3-1) By adjusting the application of voltage between the electrodes, an aqueous dispersion of graphene oxide having a solid content concentration of 1.98 mass% with a conductivity of 192 mS / cm was obtained in the same manner as in Production Example 1.

[0080] (Production Example 3-2) In the same manner as in Production Example 1, an aqueous dispersion of graphene oxide having a solid content concentration of 1.98 mass% with a conductivity of 313 mS / cm was obtained.

[0081] (Production Example 3-2) By adjusting the application of voltage between the electrodes, an aqueous dispersion of graphene oxide having a solid content concentration of 1.98 mass% with a conductivity of 7306 mS / cm was obtained in the same manner as in Production Example 1.

[0082] [Microbial control material] (Example 3-1) Gauze (100% cotton material) cut out to 30 cm × 30 cm was washed with ion-exchanged water and dried. Then, 10 mL of an aqueous dispersion of graphene oxide diluted to a concentration of 0.5 mass% with the graphene oxide dispersion obtained in Production Example 3-1 (containing 50 mg of graphene oxide) was applied to the gauze at 55.6 μg / cm 2It was impregnated so as to achieve this. After confirming that there was no liquid dripping, it was dried overnight at room temperature (25 °C) to obtain gauze carrying graphene oxide (hereinafter referred to as "G-GO").

[0083] (Example 3-2) G-GO was obtained in the same manner as in Example 3-1, except that the aqueous dispersion of graphene oxide obtained in Production Example 3-2 was used instead of the aqueous dispersion of graphene oxide obtained in Production Example 3-1.

[0084] (Example 3-3) G-GO was obtained in the same manner as in Example 3-1, except that the aqueous dispersion of graphene oxide obtained in Production Example 3-3 was used instead of the aqueous dispersion of graphene oxide obtained in Production Example 3-1.

[0085] (Test Example 2A-1) A test piece of 0.40 ± 0.05 g was cut out from the gauze of G-GO obtained in Example 3-1, placed in a sterilized 30 mL vial, and in accordance with the provisions of JIS L1902 (2015), 0.2 mL of the test inoculation bacterial solution (S. aureus 1.61×10 5 CFU) was pipetted onto several places on G-GO and cultured at 37 °C for 24 hours. Then, 20 mL of the physiological saline for washing prepared using 4.25 g of sodium chloride, 1 g of polysorbate 80, and 500 mL of ultrapure water was added to the cultured G-GO. After thoroughly stirring with a vortex mixer, the number of colonies was counted.

[0086] (Test Example 2A-2) The number of colonies was counted in the same manner as in Test Example 2A-1, except that the G-GO obtained in Example 3-2 was used instead of the G-GO obtained in Example 3-1.

[0087] (Test Example 2A-3) The number of colonies was counted in the same manner as in Test Example 2A-1, except that the G-GO obtained in Example 3-3 was used instead of the G-GO obtained in Example 3-1.

[0088] (Test Example 2a; Control) A test piece weighing 0.40 ± 0.05 g was cut out from gauze (100% cotton material) cut into 30 cm × 30 cm, placed in a sterilized 30 mL vial, and in accordance with the provisions of JIS L1902 (2015), 0.2 mL of the test inoculation bacterial solution (S. aureus 1.61×10 5 CFU) was pipetted onto several places on the gauze and cultured at 37°C for 24 hours. Then, 20 mL of physiological saline for washing prepared using 4.25 g of sodium chloride, 1 g of polysorbate 80, and 500 mL of ultrapure water was added, and after thoroughly stirring with a vortex mixer, the number of colonies was counted.

[0089] Table 2 shows the test results of each test example, indicating the values of the growth value G and the antibacterial activity value A. The antibacterial activity value A was calculated by the following formula (1).

[0090]

Number

[0091] In the above formula, C t is the arithmetic mean value of the viable bacteria count after culture, C0 is the arithmetic mean value of the viable bacteria count immediately after inoculation, T t is the arithmetic mean value of the viable bacteria count after culture, T0 is the arithmetic mean value of the viable bacteria count immediately after inoculation, and when C0 > T0, C0 was adopted.

[0092] It can be seen from Table 2 that Test Examples 2A-1, 2A-2, and 2A-3 showed high antibacterial activity values A. That is, it can be said that the G-GO obtained in Examples 3-1, 3-2, and 3-3 showed high antibacterial activity values A. Therefore, it was demonstrated that the gauze supported with graphene oxide containing a fluorine component can exhibit excellent microbial control performance (sterilization performance) and is suitable as a microbial control material.

[0093]

Table 2

Claims

1. containing graphene oxide and a fluorine component, wherein the fluorine component is at least one selected from the group consisting of tetrafluoroboric acid, fluoroboric acid, sodium fluoroborate, potassium fluoroborate, and ammonium fluoroborate, a composition for controlling microorganisms.

2. The composition for controlling microorganisms according to Claim 1, further containing a dispersion medium.

3. The composition for controlling microorganisms according to Claim 1, which is in powder form.

4. The composition for controlling microorganisms according to Claim 1, which is in paste form.

5. The composition for controlling microorganisms according to any one of Claims 1 to 4, which is for sterilization or antibacterial use.

6. A bactericide containing the composition for controlling microorganisms according to any one of Claims 1 to 4.

7. An antibacterial agent containing the composition for controlling microorganisms according to any one of Claims 1 to 4.

8. Graphene oxide and a fluorine component are supported on a substrate, wherein the fluorine component is at least one selected from the group consisting of tetrafluoroboric acid, fluoroboric acid, sodium fluoroborate, potassium fluoroborate, and ammonium fluoroborate, a material for controlling microorganisms.

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