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

Abstract

Provided are a composition for controlling microorganisms having an excellent microorganism controlling effect, a bactericide, an antibacterial agent, and a microorganism control material containing the composition. 【Solution means】The composition for controlling microorganisms of the present invention contains a first microorganism control component and a second microorganism control component, and the first microorganism control component consists of graphene oxide and a fluorine component. Further, the microorganism control material of the present invention is formed by supporting the first microorganism control component and the second microorganism control component on a substrate, and the first microorganism control component consists of graphene oxide and a fluorine component. The composition for controlling microorganisms and the microorganism control material of the present invention have an excellent microorganism controlling 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, mold, etc.). From this perspective, the newly developed 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 new 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 subject matters described in the following items. Item 1 A microbial control composition containing a first microbial control component and a second microbial control component, wherein the first microbial control component consists of graphene oxide and a fluorine component. Item 2 The microbial control composition according to Item 1, further containing a dispersion medium. Item 3 The microbial control composition according to Item 1, which is in powder form. Item 4 The microbial control composition according to Item 1, which is in paste form. Item 5 The microbial control composition according to any one of Items 1 to 4, which is for sterilization or antibacterial use. Item 6 A bactericide containing the microbial control composition according to any one of Items 1 to 4. Item 7 An antibacterial agent containing the microbial control composition according to any one of Items 1 to 4. Item 8 A microbial control material in which a first microbial control component and a second microbial control component are supported on a substrate, wherein the first microbial control component consists of graphene oxide and a fluorine component. Item 9 A method for controlling microorganisms using the microbial control composition according to any one of Items 1 to 5.

Advantages of the Invention

[0009] The microbial control composition of the present invention has an excellent microbial control effect and can be easily manufactured.

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", "consisting essentially of", and "consisting only of" are included.

[0012] In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value of a numerical range at a certain step can be arbitrarily combined with the upper limit value or lower limit value of a numerical range at another step. 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, 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 a first microorganism control component and a second microorganism control component, and the first microorganism control component consists of graphene oxide and a fluorine component. In the composition for controlling microorganisms of the present invention, the first microorganism control component (graphene oxide and a fluorine component) and the second microorganism control component are components (active ingredients) capable of exerting 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 effect" refers to an effect of suppressing the activity 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., and in this specification, these effects are collectively referred to as the "microorganism control effect".

[0016] [First microorganism control component] (Graphene oxide) The composition for controlling microorganisms of the present invention contains, as an essential component, a first microorganism control component consisting of graphene oxide and a fluorine component. That is, the composition for controlling microorganisms 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, and for example, various known graphene oxides can be used. Graphene oxide may be so-called reduced graphene oxide 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 controlling microorganisms 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 controlling microorganisms of the present invention is advantageous in that the microorganism control effect is likely to be enhanced, the production of graphene oxide is easier, and in some cases, a fluorine component can also be obtained simultaneously.

[0019] When obtaining graphene oxide by an electrolysis method, the method is not particularly limited, and for example, a known electrolysis method can be widely adopted. When producing graphene oxide by an electrolysis method, an apparatus including at least a power source, an electrolytic solution, and electrodes (an anode and a cathode) can be used. As the power source, for example, a known power source conventionally used in electrolysis methods 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, and for example, they can have 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 the inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, phosphoric acid, hydrofluoric acid, etc. Examples of the organic acids include succinic acid, citric acid, tartaric acid, diacetyl tartaric acid, malic acid, adipic acid, glutaric acid, maleic acid, fumaric acid. Examples of the inorganic salts include sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, etc.

[0023] As the electrolytic solution, it is preferable to use a compound containing fluorine and sulfuric acid (concentrated sulfuric acid or dilute sulfuric acid), etc. Among them, it is more preferable to use a compound containing fluorine. This is because in this case, the fluorine component can be obtained simultaneously with graphene oxide. Examples of the compound containing fluorine include the above-mentioned hydrofluoric acid borate, sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, etc.

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

[0025] The concentration of the electrolytic solution is not particularly limited. For example, in terms of efficiently obtaining graphene oxide, the electrolytic solution concentration 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 electrolytic solution temperature 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 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 not particularly limited either. For example, it can be the same as the known electrolysis method.

[0027] By the above electrolysis, graphene oxide is produced, for example, in a sheet-like shape. After electrolysis, the electrolytic solution is squeezed, and then, if necessary, washing treatment and / or ultrasonic treatment are performed to exfoliate or disperse graphene oxide, 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, etc.

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

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

[0031] In graphene oxide, the oxygen content is not particularly limited and can have, for example, 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 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 graphene oxide and fluorine component contained in the microbial control composition of the present invention. The oxygen content of graphene oxide can be quantified by elemental analysis using EDS (energy dispersive X-ray spectroscopy).

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

[0033] Note that graphene oxide may unavoidably contain, for example, graphite as a raw material.

[0034] When the graphene oxide is the above-described 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 microbial control of the present invention contains a fluorine component as an essential component. When the composition for microbial control of the present invention does not contain a fluorine component, the microbial control performance of graphene oxide cannot be exhibited.

[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 first microbial control component is derived from the compound or mixture containing the fluorine.

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

[0039] Specifically, the fluorine component can form a composite structure with graphene oxide through 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 fluorine-containing compound, the fluorine component is likely to form a composite structure with graphene oxide. That is, the first microbial control component may be a complex of graphene oxide and a fluorine component.

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

[0041] In the composition for microbial control of the present invention, the fluorine content is not particularly limited. For example, in terms of being likely to improve the microbial 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 the fluorine component contained in the first microbial control component, and 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] [Second Microbial Control Component] The second microbial control component is a component other than the first microbial control component. That is, the second microbial control component is a component other than graphene oxide and the fluorine component.

[0043] The second microbial control component is a component other than graphene oxide and the fluorine component, and as long as it has microbial control performance, its type is not particularly limited, and for example, known microbial control components can be widely exemplified.

[0044] Examples of the second microbial control component include acrinol, decalinium chloride, tetracycline, oxytetracycline, decalinium acetate, benzalkonium chloride, benzethonium chloride, chlorhexidine, chlorhexidine hydrochloride, chlorhexidine gluconate, alkyl diaminethyl glycine hydrochloride, cetylpyridinium chloride, sodium benzoate, chlorobutanol, isopropylmethylphenol, thymol, sorbic acid, potassium sorbate, sodium dehydroacetate, methyl paraoxybenzoate, ethyl paraoxybenzoate, propyl paraoxybenzoate, butyl paraoxybenzoate, oxyquinoline sulfate, phenethyl alcohol, benzyl alcohol, hinokitiol, resorcinol, povidone iodine, berberine benzoate, biguanide compounds, and the like.

[0045] The second microbial control component may be a single species or two or more species.

[0046] The second microbial control component can exist independently of graphene oxide or can be physically or chemically bonded to graphene oxide. For example, the second microbial control component may be physically adsorbed on graphene oxide.

[0047] (Composition for microbial control) In the composition for microbial control of the present invention, the content ratios of the first microbial control component and the second microbial control component are not particularly limited. For example, the content ratio of the second microbial control component is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, further preferably 3 part by mass or more, still more preferably 5 part by mass or more, particularly preferably 8 part by mass or more, per 100 parts by mass of graphene oxide contained in the first microbial control component, and preferably 500 parts by mass or less, more preferably 100 parts by mass or less, further preferably 50 parts by mass or less, still more preferably 30 parts by mass or less, particularly preferably 20 parts by mass or less.

[0048] The composition for controlling microorganisms of the present invention can contain a dispersion medium as necessary in addition to the first and second microorganism control components. Examples of the dispersion medium include various solvents, for example, the solvents contained in conventional compositions for controlling microorganisms. 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.

[0049] 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 in which graphene oxide in the first microorganism control component is dispersed in the dispersion medium. When the composition for controlling microorganisms of the present invention is a dispersion, the solid content concentration is not particularly limited, and in terms of being likely to exhibit the microorganism control performance, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and 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, can mean those that become solids when the dispersion medium is removed.

[0050] The composition for controlling microorganisms of the present invention can also have a form other than a dispersion, for example, it can be in powder form or in paste form. When the composition for controlling microorganisms of the present invention is in powder form or 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.

[0051] The composition for controlling microorganisms of the present invention can contain other additives in addition to the dispersion medium, and for example, 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 composed only of graphene oxide and fluorine component as components other than the dispersion medium.

[0052] The composition for controlling microorganisms of the present invention contains a fluorine component. 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.

[0053] 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%). For the measurement, a commercially available conductivity meter can be used.

[0054] When the composition for controlling microorganisms of the present invention is in a solid state 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.

[0055] 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 aforementioned electrolysis method and the produced graphene oxide contains a fluorine component, a dispersion of graphene oxide obtained by the electrolysis method can be obtained as the first microorganism control component. Therefore, the composition for controlling microorganisms of the present invention can be prepared by blending the dispersion of graphene oxide obtained by such an electrolysis method and the second microorganism control component at a predetermined ratio.

[0056] 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 reproduction. Therefore, the composition for controlling microorganisms of the present invention can be suitably used for sterilization or antibacterial purposes.

[0057] 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.

[0058] Bactericides and antibacterial agents can exhibit bactericidal and antibacterial actions against harmful microorganisms (such as 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. Among them, the composition for controlling microorganisms of the present invention can exhibit excellent action against aerobic symbiotic bacteria such as aerobic symbiotic bacteria such as Escherichia coli and Staphylococcus aureus.

[0059] 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 known methods.

[0060] 2. Microorganism control material The present invention also includes a microorganism control material. Such a microorganism control material is formed by supporting a first microorganism control component and a second microorganism control component on a substrate, and the first microorganism control component consists of graphene oxide and a fluorine component. In the microorganism control material of the present invention, the first microorganism control component (graphene oxide and fluorine component) and the second microorganism control component are the same as the first microorganism control component (graphene oxide and fluorine component) and the second microorganism control component contained in the microorganism control composition of the present invention.

[0061] The type of the substrate is not particularly limited, and examples include fibrous substrates such as woven fabrics or non-woven fabrics, and various substrates such as resin substrates, inorganic substrates, wood, and metal substrates can also be mentioned.

[0062] 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 dispersion liquid of the microorganism control composition is prepared, and the microorganism control material is produced by a method of bringing such a dispersion liquid into contact with the substrate. In this case, the dispersion liquid preferably has a conductivity within the above-mentioned range.

[0063] 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 combinable configurations described in this specification.

Examples

[0064] 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.

[0065] (Production Example 1) A graphite sheet was placed as the anode and a platinum electrode as the cathode 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% by mass. The conductivity of the aqueous dispersion of graphene oxide was 313 mS / cm.

[0066] (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% by mass, and 50 mL of it was centrifuged (10000 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% by mass concentration) obtained by this centrifugation was carried out, followed by centrifugation (10000 pm, 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.

[0067] (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.

[0068] 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-fold 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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 oxidation degree of the graphene oxide was 1.92. In this specification, the oxidation degree can mean the value of "carbon content ratio / oxygen content ratio".

[0073]

Table 1

[0074] (Example 1-1) The dispersion of graphene oxide (containing fluorine) obtained in Production Example 1 was diluted so that the graphene oxide concentration became 1 mg / mL, and this was prepared as a dispersion of the first microbial control component. Also, an aqueous solution of acrinol at a concentration of 125 μg / mL was prepared as a solution of the second microbial control component. 50 mL of the dispersion of the first microbial control component and 50 mL of the solution of the second microbial control component were mixed and stirred at 200 rpm for 3 days to obtain a composition (dispersion) for microbial control.

[0075] (Example 1-2) A microbial control composition (dispersion) was obtained in the same manner as in Example 1-1, except that the aqueous acrinol solution was changed to an aqueous chlorhexidine solution at a concentration of 125 μg / mL.

[0076] (Example 1-3) A microbial control composition (dispersion) was obtained in the same manner as in Example 1-1, except that the aqueous acrinol solution was changed to an aqueous benzalkonium chloride solution at a concentration of 125 μg / mL.

[0077] (Example 1-4) A microbial control composition (dispersion) was obtained in the same manner as in Example 1-1, except that the aqueous acrinol solution was changed to an aqueous tetracycline solution at a concentration of 125 μg / mL.

[0078] (Adsorption of the second microbial control component onto graphene oxide) From the results of ultraviolet-visible spectrum measurements of the microbial control compositions obtained in Examples 1-1, 1-2, 1-3, and 1-4, it was found that more than 90% of each second microbial control component was adsorbed onto graphene oxide. In particular, it was confirmed that more than 90% of the adsorption occurred at least 3 hours after starting the mixing of the first microbial control component and the second microbial control component.

[0079] (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 using an autoclave and stored at 57 °C to prepare the MHA medium. - Ultrapure water: 500 mL - Starch: 0.75 g - Beef extract: 1 g - Casein acid hydrolyzate: 8.7 g - Agar: 1.7% (8.5 g) - NaOH: 850 μL

[0080] (Test Example 1A-1) The microbial control composition obtained in Example 1-1 was stirred and dispersed in a vortex mixer in advance, and then 3 mL was collected. To this, 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 of 5 mL, and mixed with a vortex mixer to obtain a test solution. This test solution was cultured at 37 °C for 24 hours while shaking and stirring at a rotation speed of 160 rpm in a shaking incubator. After the culture was completed, it was stirred with a vortex mixer, then 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.

[0081] (Test Example 1A-2) Cultivation was carried out in the same manner as in Test Example 1A-1, except that the microbial control composition obtained in Example 1-2 was used instead of the microbial control composition obtained in Example 1-1.

[0082] (Test Example 1A-3) Cultivation was carried out in the same manner as in Test Example 1A-1, except that the microbial control composition obtained in Example 1-3 was used instead of the microbial control composition obtained in Example 1-1.

[0083] (Test Example 1A-4) Cultivation was carried out in the same manner as in Test Example 1A-1, except that the microbial control composition obtained in Example 1-4 was used instead of the microbial control composition obtained in Example 1-1.

[0084] (Reference Test Example 1A) Cultivation was carried out in the same manner as in Test Example 1A-1, except that the aqueous dispersion of graphene oxide obtained in Production Example 1 was used instead of the microbial control composition obtained in Example 1-1.

[0085] (Test Example 1a; Control) 500 μL of E. coli and an aqueous solution of 0.9% NaCl were added to make a total volume of 5 mL, and the mixture was mixed with a vortex mixer to obtain a test solution. Such a test solution was held at 37°C for 24 hours while being shaken and stirred at a rotational speed of 160 rpm with a shaking incubator. Thereafter, after stirring 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.

[0086] (Results of Test Examples 1A-1 to 1A-4) Figure 5 shows the results of Test Example 1A-1, Test Example 1A-2, Test Example 1A-3, and Test Example 1A-4. 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 after 3 hours of culture.

[0087] From these results, it was shown that the microbial control compositions used in Test Examples 1A-1, 1A-2, 1A-3, and 1A-4 had an excellent bactericidal effect against E. coli compared to the aqueous dispersion of graphene oxide used in Reference Test Example 1A. The microbial control compositions obtained in Example 1-3 and Example 1-4 (containing benzalkonium chloride and tetracycline, respectively) showed the disappearance of bacteria at 3 hours from the start of culture. Therefore, it was demonstrated that the microbial control compositions obtained in each example had a bactericidal effect.

[0088] [Microbial Control Material] (Example 2-1) A 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 (containing 50 mg of graphene oxide) obtained by diluting the microbial control composition obtained in Example 1-4 to a concentration of 0.5 mass% was applied to the gauze at 55.6 μg / cm 2It was impregnated so as to achieve this. After confirming that there was no dripping of the liquid, it was dried overnight at room temperature (25 °C) to obtain gauze carrying graphene oxide (hereinafter referred to as "G-GO1"). Next, 10 mg of tetracycline hydrochloride (TC) was dissolved in 200 mL of ion-exchanged water in a beaker to prepare a 50 mg / L solution, and G-GO1 was immersed therein and left standing at room temperature for 3 hours. To prevent volatilization, the beaker was covered with parafilm. Thereafter, G-GO1 was taken out from the beaker and dried overnight in the air to obtain a microbial control material in which graphene oxide (fluorine-containing) and TC were carried on the gauze. Hereinafter, this microbial control material was designated as "G-GO2".

[0089] (Example 2-2) G-GO2 was obtained in the same manner as in Example 2-1, except that the microbial control composition obtained in Example 1-3 was used instead of the microbial control composition obtained in Example 1-4.

[0090] (Comparative Example 2-1) Gauze (100% cotton material) cut out to 30 cm × 30 cm was washed with ion-exchanged water and dried. Next, 10 mg of tetracycline hydrochloride (TC) was dissolved in 200 mL of ion-exchanged water in a beaker to prepare a 50 mg / L solution, and the gauze was immersed therein and left standing at room temperature for 3 hours. To prevent volatilization, the beaker was covered with parafilm. Thereafter, the gauze was taken out from the beaker and dried overnight in the air to obtain a microbial control material in which TC was carried on the gauze.

[0091] (Comparative Example 2-2) Gauze (100% cotton material) cut out to 30 cm × 30 cm was washed with ion-exchanged water and dried. Next, 10 mg of benzalkonium chloride (BK) was dissolved in 200 mL of ion-exchanged water in a beaker to prepare a 50 mg / L solution, and the gauze was immersed therein and left standing at room temperature for 3 hours. To prevent volatilization, the beaker was covered with parafilm. Thereafter, the gauze was taken out from the beaker and dried overnight in the air to obtain a microbial control material in which BK was carried on the gauze.

[0092] (Test Example 2A-1) The G-GO2 obtained in Example 2-1 was placed in a sterilized 30 mL vial. In accordance with the provisions of JIS L1902 (2015), 0.2 mL of the test inoculum (S. aureus 1.61×10 5 CFU) was pipetted onto several locations on the G-GO2 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 to the cultured G-GO2. After thoroughly stirring with a vortex mixer, the number of colonies was counted.

[0093] (Test Example 2A-2) The number of colonies was counted in the same manner as in Test Example 2A-1, except that the G-GO2 obtained in Example 2-2 was used instead of the G-GO2 obtained in Example 2-1.

[0094] (Comparative Test Example 2A-1) The number of colonies was counted in the same manner as in Test Example 2A-1, except that the gauze obtained in Comparative Example 2-1 was used instead of the G-GO2 obtained in Example 2-1.

[0095] (Comparative Test Example 2A-2) The number of colonies was counted in the same manner as in Test Example 2A-1, except that the gauze obtained in Comparative Example 2-2 was used instead of the G-GO2 obtained in Example 2-1.

[0096] (Test Example 2a; Control) A test piece of 0.40 ± 0.05 g was cut from a gauze (100% cotton material) cut into 30 cm × 30 cm. This was placed in a sterilized 30 mL vial. In accordance with the provisions of JIS L1902 (2015), the test inoculum (S. aureus 1.61×10 50.2 mL of CFU was pipetted and inoculated at several locations, followed by culturing at 37 °C for 24 hours. Subsequently, 20 mL of washing physiological saline 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-GO2. After thoroughly stirring with a vortex mixer, the number of colonies was counted.

[0097] Figure 6 shows the adsorption amount of the second microbial control component (TC or BK) of the microbial control materials obtained in each example and comparative example. From this result, it can be seen that in the microbial control material containing graphene oxide, the adsorption amount of the second microbial control component (TC or BK) is larger than that of the microbial control material not containing graphene oxide.

[0098] 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).

[0099]

Number

[0100] In the above formula, C t is the arithmetic mean value of the viable cell count after culturing, C0 is the arithmetic mean value of the viable cell count immediately after inoculation, T t is the arithmetic mean value of the viable cell count after culturing, T0 is the arithmetic mean value of the viable cell count immediately after inoculation, and when C0 > T0, C0 was adopted.

[0101] It can be seen from Table 2 that Test Examples 2A-1 and 2A-2 show high antibacterial activity values A. From this, it is demonstrated that the microbial control material containing the first microbial control component (graphene oxide and fluorine component) and the second microbial control component can exhibit superior microbial control performance (bactericidal performance) compared to the microbial control materials not containing the first microbial control component (Comparative Examples 2-1 and 2-2), and is suitable as a microbial control material.

[0102]

Table 2

Claims

1. A microbial control composition containing a first microbial control component and a second microbial control component other than the first microbial control component, wherein the first microbial control component consists of graphene oxide and a fluorine component, and the fluorine component is at least one selected from the group consisting of tetrafluoroboric acid, fluoboric acid, sodium fluoborate, potassium fluoborate, and ammonium fluoborate.

2. The microbial control composition according to Claim 1, further containing a dispersion medium.

3. The microbial control composition according to Claim 1, which is in powder form.

4. The microbial control composition according to Claim 1, which is in paste form.

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

6. A bactericide containing the microbial control composition according to any one of Claims 1 to 4.

7. An antibacterial agent containing the microbial control composition according to any one of Claims 1 to 4.

8. A microbial control material in which a first microbial control component and a second microbial control component other than the first microbial control component are supported on a substrate, wherein the first microbial control component consists of graphene oxide and a fluorine component, and the fluorine component is at least one selected from the group consisting of tetrafluoroboric acid, fluoboric acid, sodium fluoborate, potassium fluoborate, and ammonium fluoborate.

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