Antibiofilm composition and antibiofilm coating

Abstract

This invention provides an antibiofilm composition and an antibiofilm coating that have excellent antibiofilm properties. [Solution] An antibiofilm composition characterized in which particles of a monovalent copper compound are dispersed in an organic compound, and the polarity ratio in surface free energy, which is the ratio of the polar component to the sum of the dispersion component and the polar component of the surface free energy, is 0.5% or more and 8.0% or less. Also, an antibiofilm paint containing particles of a monovalent copper compound, characterized in which the polarity ratio in surface free energy, which is the ratio of the polar component to the sum of the dispersion component and the polar component of the surface free energy of the formed coating film, is 0.5% or more and 8.0% or less.

Description

Technical Field

[0001] Relates to an anti-biofilm composition and an anti-biofilm paint that suppress the formation of biofilms.

Background Art

[0002] Biofilms, which are aggregates composed of substances produced by microorganisms and the cells themselves, have become a problem. Biofilms are a typical example of the sliminess found in areas around water such as kitchens and bathrooms, but they also cause various social and industrial problems. For example, in air conditioning and cooling equipment, biofilms may form on the drain pan that receives condensate drainage, causing blockages in the drain outlets and drain pumps. In addition, when biofilms adhere to the heat exchanger of air conditioning equipment, the heat exchange efficiency may decrease and the microorganisms may scatter into the surrounding environment. Also, in a sewage heat utilization system that uses sewage heat for heating, ventilation, and hot water supply, biofilms may adhere to the surface of the heat exchanger, resulting in a decrease in heat exchange efficiency. Furthermore, biofilms may form on the filtration membranes of water treatment facilities that treat wastewater and cause blockages in the filtration membranes. Blockage of the filtration membranes leads to an increase in filtration energy. Thus, biofilms are a problem not only from a hygienic perspective but also from an energy-saving perspective in water-related scenarios, and the development of anti-biofilm products is demanded.

[0003] As an anti-biofilm technology, for example, a technology has been proposed in which a slime (biofilm) inhibitor containing a predetermined polyvinyl alcohol-based resin is added to cooling water or the like used in a device to suppress the generation of biofilms (Patent Document 1). Also, fine particles composed of a polycarboxylic acid derivative and a drug have been proposed, which have an effect of suppressing biofilm formation even in an environment such as around water and can also be used as a coating agent (Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] However, conventional methods did not provide sufficient antibiofilm properties. Furthermore, it was difficult to impart sufficient antibiofilm properties to the materials or paints (coatings) used in areas where biofilms were likely to form. For example, simply mixing antibacterial components into resins or paints was not effective in suppressing biofilm formation, making it difficult to manufacture materials or paints that could prevent biofilm growth.

[0006] Therefore, the present application aims to provide an antibiofilm composition and an antibiofilm coating that exhibit more effective antibiofilm properties. [Means for solving the problem]

[0007] In other words, the means to solve the above problems are as follows:

[0008] (1) A composition in which particles of a monovalent copper compound are dispersed in an organic compound, An antibiofilm composition characterized in that the polarity ratio in surface free energy, which is the ratio of the polar component to the sum of the dispersion component and the polar component of the surface free energy, is 0.5% or more and 8.0% or less.

[0009] (2) The antibiofilm composition according to (1) above, characterized in that the monovalent copper compound is copper(I) iodide.

[0010] (3) The antibiofilm composition according to (1) above, characterized in that the water contact angle is 90° or more and 99° or less.

[0011] (4) The antibiofilm composition according to (1) above, characterized in that the organic compound is a resin.

[0012] (5) The antibiofilm composition according to (4) above, characterized in that the resin is polypropylene.

[0013] (6) The antibiofilm composition according to (5) above, characterized in that the polypropylene is a homopolymer.

[0014] (7) The antibiofilm composition according to (1) above, characterized in that it is in the form of a sheet.

[0015] (8) The antibiofilm composition according to (1) above, characterized in that it is a molded article formed by injection molding.

[0016] (9) The antibiofilm composition according to (1) above, characterized in that it is a coating film.

[0017] (10) The antibiofilm composition according to (9) above, characterized in that the organic compound is a water-soluble polymer.

[0018] (11) The antibiofilm composition according to (10) above, characterized in that the water-soluble polymer is hydroxypropyl cellulose.

[0019] (12) A paint containing particles of a monovalent copper compound, An anti-biofilm coating characterized in that the polarity ratio in the surface free energy of the formed coating film, which is the ratio of the polar component to the sum of the dispersion component and the polar component, is 0.5% or more and 8.0% or less.

[0020] (13) The antibiofilm coating according to (12) above, characterized in that the monovalent copper compound is copper(I) iodide.

[0021] (14) The anti-biofilm coating material according to (12) above, characterized in that the contact angle of water with the coating film is 90° or more and 99° or less.

[0022] (15) The anti-biofilm coating material according to (12) above, characterized in that it contains a polyfunctional acrylate compound or a polyfunctional methacrylate compound as a base resin.

Advantages of the Invention

[0023] According to the present invention, it is possible to provide an anti-biofilm composition and an anti-biofilm coating material that more effectively exhibit anti-biofilm properties.

Modes for Carrying Out the Invention

[0024] (First Embodiment) An anti-biofilm composition according to the first embodiment will be described. In this embodiment, as an example, an embodiment of a sheet-like anti-biofilm composition (hereinafter also referred to as an "anti-biofilm sheet"), which is one form of the anti-biofilm composition, will be described. However, the present invention is not limited thereto, and it can be applied to various forms of compositions. The anti-biofilm sheet of the present embodiment is a sheet in which particles of a monovalent copper compound are dispersed in an organic compound. In this embodiment, a sheet in which a monovalent copper compound is dispersed in a resin, which is an example of an organic compound, will be described. The anti-biofilm sheet of the present embodiment can be formed by mixing a monovalent copper compound into a base resin (hereinafter also referred to as a "base resin") and molding it into a sheet shape (or a film shape). The anti-biofilm sheet (anti-biofilm composition) of the present embodiment can have a ratio of the polar component to the sum of the dispersion component and the polar component of the surface free energy of its surface (hereinafter, in the present application, this ratio of the polar component is also referred to as the "polar ratio in surface free energy" or simply the "polar ratio") of 0.5% or more and 8.0% or less.

[0025] The base resin that serves as the substrate for the antibiofilm sheet is not particularly limited as long as it is a (synthetic) resin (synthetic polymer material) whose polarity ratio can be adjusted to 0.5% or more and 8.0% or less, either as a property of the base resin itself or by adding additives. For example, thermoplastic resins and thermoplastic elastomers can be used as the base resin. Examples of thermoplastic resins include polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, EVA resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, methyl polyacrylate resin, polyvinyl acetate resin, polyamide resin, polyimide resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyacetal resin, polyarylate resin, and polysulfone resin. Examples of thermoplastic elastomers include silicone resin, styrene-based elastomers such as polystyrene elastomer, olefin-based elastomers such as polyethylene elastomer and polypropylene elastomer, polyurethane-based elastomers such as polyurethane elastomer, vinyl chloride-based elastomer, polyester-based elastomer, and nylon-based elastomer. In this context, polypropylene (PP) is preferably used as the base resin. Furthermore, it is preferable to use homopolymer polypropylene, which is a polymer of only propylene, because the polarity ratio can be easily adjusted with additives.

[0026] Monovalent copper compounds function as antimicrobial materials with antibacterial and antiviral properties in antibacterial biofilm sheets. Examples of monovalent copper compounds include CuI (copper(I) iodide), CuCl, Cu(CH3COO), CuBr, CuI, CuSCN, Cu2S, and Cu2O. CuI is particularly preferred due to its excellent safety and stability, and its white color, which minimizes damage to the product's color.

[0027] The monovalent copper compound only needs to be dispersed as particulate matter in the sheet formed by the base resin. The particle size of the monovalent copper compound is not particularly limited and can be set appropriately by those skilled in the art. For example, the average particle size can be 1 nm or more and less than 1 μm. Being within this range ensures material stability and provides sufficient antimicrobial effect. In this application, the average particle size refers to the volume-average particle size. The volume-average particle size can be measured based on the laser Doppler method (dynamic electrophoretic light scattering method). A zeta potential / particle size measurement system (manufactured by Otsuka Electronics) can be used as the measuring device.

[0028] Monovalent copper compounds can be included in antibiofilm sheets in appropriate amounts. For example, they can be included in a mass fraction of 0.1% to 30% of the entire antibiofilm sheet. Including them within this range allows for maintaining the strength of the sheet, minimizing the impact on water contact, and obtaining sufficient antibiofilm performance. If the amount is less than 0.1%, sufficient antibiofilm properties will not be achieved. If it exceeds 30%, the strength of the antibiofilm sheet will decrease or the antibiofilm effect will saturate, so 30% or less is preferable. In the case of antibiofilm compositions that are thicker than sheets (such as molded products), it is sufficient for the monovalent copper compound to be included at least in the outer surface portion where a biofilm may form upon contact with moisture.

[0029] The antibiofilm sheet (antibiofilm composition) may further contain various additives. The additives can be appropriate substances depending on the required functions of the antibiofilm sheet. Examples of additives include plasticizers, desiccants, curing agents, anti-skinning agents, planarizing agents, anti-sagging agents, antifungal agents, UV absorbers, heat absorbers, lubricants, surfactants, thickeners, viscosity modifiers, stabilizers, and drying modifiers. These additives may be used individually or in combination of two or more. Furthermore, other antibacterial compositions, antiviral compositions, antifungal compositions, anti-allergen compositions, catalysts, anti-reflective materials, and materials with heat-shielding properties may be added as additives other than monovalent copper compounds.

[0030] The polarity ratio in the surface free energy of the antibiofilm sheet (antibiofilm composition) of this embodiment can be 0.5% or more and 8.0% or less, as described above. Here, the polarity ratio in the surface free energy is the ratio (%) of the polar component (γsp) to the sum of the dispersion component (γsd) and polar component (γsp) of the surface free energy of the sheet surface. It is also expressed as the polarity component ratio (rate) of the surface free energy. Surface free energy refers to the energy that molecules (or atoms) present on a solid or liquid surface possess in excess of molecules (or atoms) present inside the solid or liquid. Surface free energy (γs) is defined by the following equation (1), and the polarity ratio (Rγp) is defined by the following equation (2).

[0031] γs = γsd + γsp (1) Rγp = γsp / γs × 100 (2) In equations (1) and (2) above, γs is the surface free energy, γsd is the dispersion component (nonpolar component) in the surface free energy γs, γsp is the polar component in the surface free energy γs, and Rγp is the polarity ratio.

[0032] When measuring the surface free energy γs, first, a measuring liquid (water and diiodomethane, respectively) is dropped onto the surface of the antibiofilm sheet (antibiofilm composition) to be measured, and the contact angle (θ) of each measuring liquid is measured using a contact angle meter. Based on the obtained contact angle values ​​and equation (3) below, the dispersion component γsd and the polar component γsp are calculated. In this embodiment, the contact angle is the contact angle measured by the droplet method.

[0033]

number

[0034] In equation (3) above, γsd is the dispersion component of the surface free energy of the antibiofilm sheet surface, γLd is the dispersion component of the surface free energy of the measurement liquid (water or diiodomethane), γsp is the polar component of the surface free energy of the antibiofilm sheet surface, γLp is the polar component of the surface free energy of the measurement liquid (water or diiodomethane), γL is the surface tension of the measurement liquid (water or diiodomethane), and θ is the contact angle of the measurement liquid with the antibiofilm sheet surface.

[0035] For the two measurement liquids (water and diiodomethane), the surface tension γL, dispersion component γLd, and polar component γLp can be measured in advance. By substituting the contact angle θ of the two measurement liquids into equation (3) above and solving the resulting system of equations, the dispersion component γsd and polar component γsp of the antibiofilm sheet surface can be calculated. Substituting the obtained dispersion component γsd and polar component γsp into equation (1) above, the surface free energy γs can be calculated, and substituting this surface free energy γs and polar component γsp into equation (2) above, the polarity ratio Rγp can be calculated.

[0036] If the polarity ratio of the surface free energy of the anti-biofilm sheet is between 0.5% and 8.0%, the adhesion of biofilm to the sheet can be further suppressed. If it is less than 0.5% or greater than 8.0%, bacteria themselves and bacterial metabolites, which are components of biofilm, will adhere more easily, and the adhesion force will also be stronger.

[0037] In this embodiment, the antibiofilm sheet preferably has a water contact angle of 90° to 99°. This range allows for greater suppression of biofilm adhesion. If the water contact angle is less than 90° or greater than 99°, bacteria themselves and bacterial metabolites, which are components of biofilm, adhere more easily, and the adhesion force also becomes stronger.

[0038] Biofilms are formed through multiple stages. For example, they can be divided into three stages. The first stage is the attachment of microorganisms. The second stage is the formation of the biofilm. The third stage is the maturation of the biofilm. In the case of the biofilm sheet of this embodiment, the attachment of microorganisms such as bacteria is suppressed in the first stage, and even if they do attach, the antibacterial properties of the monovalent copper compound inactivate the bacteria. In the second and third stages, the radicals generated by the monovalent copper compound oxidize not only the bacteria but also the metabolites of the bacteria that make up the biofilm, thereby damaging the biofilm itself. Furthermore, because the polarity ratio of the surface free energy of the antibiofilm sheet is within the above range, in addition to suppressing the attachment of microorganisms in the first stage, the adhesion strength of the biofilm formed and matured in the second and third stages to the sheet can be reduced, making the biofilm easier to peel off, thus obtaining excellent antibiofilm properties.

[0039] According to the antibiofilm sheet of this embodiment, an antibiofilm activity value of 50% or more, as evaluated by the antibiofilm activity test (ISO 4768), can be achieved. The detailed test method of the antibiofilm activity test (ISO 4768) will be described in the examples.

[0040] Next, the method for manufacturing the antibiofilm sheet of this embodiment will be described. The antibiofilm sheet can be manufactured, for example, by producing a masterbatch (resin pellets) containing the materials to be included in the sheet, mixing these masterbatches, and then molding them. A more detailed explanation follows below.

[0041] An antimicrobial masterbatch containing a monovalent copper compound such as copper(I) iodide is manufactured. The antimicrobial masterbatch can be manufactured, for example, as follows: First, fine particles of a monovalent copper compound, whose particle size has been adjusted to the above range by grinding or the like, are mixed with resin pellets and kneaded using a kneading extruder. This allows the copper compound particles to be dispersed inside the resin pellets. The resin pellets can be made of the same resin as the base resin of the antibiofilm sheet, but by using a different base resin, a polymer alloy can be formed and the polarity component (polarity ratio) can be adjusted. After cooling the kneaded mixture, the resin pellets are finely cut using a pelletizer to obtain the antimicrobial masterbatch. The mass ratio (concentration) of the monovalent copper compound during the manufacture of the antimicrobial masterbatch can be appropriately set by a person skilled in the art so that it results in an appropriate content in the final antibiofilm sheet.

[0042] When adding additives, the masterbatch of the additive is prepared in the same manner. For example, when using a hydrophilic agent (hydrophilic polymer or surfactant) as an additive, the hydrophilic agent is mixed with the resin pellets in a predetermined ratio. The resin pellets can be the same resin as the base resin. Then, similar to the antimicrobial masterbatch, the mixture is melt-kneaded to obtain the masterbatch of the additive. If further additives are to be added, the masterbatches of the second, third, ... additives can be prepared in the same manner.

[0043] Furthermore, masterbatches may be prepared separately for each substance to be added to the antibiofilm sheet, or a masterbatch containing multiple substances obtained by mixing multiple types of additives in a single masterbatch may be used. The antimicrobial masterbatch may also contain other substances such as additives.

[0044] Next, the antimicrobial masterbatch, the masterbatch of any additives to be added as needed, and the base resin pellets (e.g., polypropylene pellets) are mixed. The masterbatch and base resin pellets are mixed so that the monovalent copper compound and additives are present in a predetermined mass ratio throughout the entire antibiofilm sheet. The mixture is melt-kneaded in an extruder and can be formed into a sheet by extruding it, for example, through a T-die. The method of forming into a sheet is not particularly limited, and any method that can form a sheet can be appropriately selected. For example, calendering, inflation molding, or casting may be used. By the above method, an antibiofilm sheet in which particles of monovalent copper compound are dispersed and kneaded can be produced.

[0045] Similarly, antibiofilm compositions in forms other than sheets can be produced. For example, as described above, a mixture of an antimicrobial masterbatch, a masterbatch of additives to be added as needed, and a base resin pellet (e.g., polypropylene pellet) can be injection molded to produce resin components such as molded articles in various forms.

[0046] According to the above embodiment, an antibiofilm sheet, which is an antibiofilm composition that can suppress the adhesion of biofilms, is obtained. Furthermore, by having a polarity ratio in the surface free energy of the antibiofilm sheet of 0.5% to 8.0% as described above, an antibiofilm sheet that can further suppress the adhesion of biofilms is obtained. Specifically, an antibiofilm sheet with excellent antibiofilm properties is obtained, with an antibiofilm activity value of 50% or more as confirmed by the antibiofilm property test (ISO 4768).

[0047] The antibiofilm sheet of this embodiment can suppress the formation of biofilms formed by various microorganisms. This is because the monovalent copper compound, which is the antibacterial component, exhibits antibacterial activity against a wide range of bacteria regardless of whether they are Gram-positive or Gram-negative, and the radicals it generates oxidize bacterial metabolites (polysaccharides, proteins, lipids, nucleic acids, etc.) that are components of the biofilm. Microorganisms whose biofilm formation can be suppressed by the antibiofilm sheet of this embodiment include, for example, Escherichia coli, Pseudomonas aeruginosa, Salmonella, Klebsiella pneumoniae, Moraxella, Vibrio parahaemolyticus, Legionella, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus, Methylobacterium, and Rhodotorula. In all cases, their adhesion can be suppressed by the antibacterial function of the monovalent copper compound contained in the antibacterial sheet.

[0048] The anti-biofilm sheet of this embodiment can be used, for example, by attaching it to parts where biofilm is generated, such as the drain pan of the air conditioning equipment mentioned above, to suppress the adhesion of biofilm. It can also be used as a sheet to be attached to water-related areas such as washbasins.

[0049] Furthermore, the antibiofilm composition according to this embodiment can be made into various forms other than the sheet shown in the embodiment. For example, it may be a molded article (molded body), a coating film (coating film), or a fiber. Specifically, it can be used for agricultural materials such as greenhouse films and tunnel greenhouse films, molded articles such as trays for plant factories, panels, building materials, interior materials, stationery such as writing instruments, handrails, straps, telephones, toys, doorknobs, clear folders, and label tapes, sheets, shrinkable materials that shrink when heated, building materials such as chairs, sofas, exterior wall materials, sashes, doors, blinds, ceiling boards, floor boards, and windows, interior materials such as wallpaper, carpets, and resin tiles, interior materials for trains and vehicles, footwear such as clothing, underwear, socks, gloves, shoe covers, and shoes, bedding such as pajamas, mats, sheets, pillows, pillowcases, blankets, towels, futons, and futon covers. It can be applied to a variety of water-contacting surface components or fibrous structures such as insect screens and screen printing meshes, including hats, handkerchiefs, towels, carpets, curtains, filters for air purifiers and air conditioners, ventilation fans, vacuum cleaners, and electric fans, fishing nets such as fish farms and fixed nets, water treatment filters, drinking water filters, ballast water treatment filters, lining materials for pipes, film-like components attached to the surface of coastal structures with adhesives or bonding agents, components attached as sheets to the surface of ships such as fishing boats and tankers, sheet-like components for the inner walls of water intakes of power plants, pre-filters for water intakes, inner surfaces of water intakes, plate coolers, drain pipes, and water supply pipes.

[0050] In this embodiment, an antibiofilm composition in which a monovalent copper compound is dispersed in a base resin is shown, but as described above, an antibiofilm composition in which a monovalent copper compound is dispersed in an organic compound other than a resin may also be used. The antibiofilm composition may be, for example, an antibiofilm coating film. The antibiofilm coating film can be formed by an antibiofilm agent in which a monovalent copper compound is dispersed in an organic compound, for example. The antibiofilm agent may be, for example, a paint or a coating agent. The antibiofilm agent may contain various additives as needed. The additives may include the various additives described above, as well as the additives described in the second embodiment.

[0051] The organic compound included in the above-mentioned antibiofilm coating should be one that can form a film and retain the monovalent copper compound on the surface of the object even after the solvent, such as alcohol or water, contained in the paint has dried away. The organic compound can be appropriately selected depending on the type of monovalent copper compound, but it is particularly preferable to use an organic compound that can suppress the oxidation of the monovalent copper compound. Examples of organic compounds that can suppress the oxidation of the monovalent copper compound include benzotriazole (BTA), mercaptobenzothiazole (MBT), benzothiazole, benzoxazole, tritriazole (TTA), 2·5-dimercaptothiadiazole (DMTDA), benzimidazole (BIA), benzimidazolethiol (BIT), benzoxazolethiol (BOT), methylbenzothiazole, methylbenzotriazole, indole, indazole, mercaptothiazoline, dithiocarbamic acid and its derivatives, and thiouracil. Examples include inhibitors such as thiobarbituric acid (TBA), imidazoline, pyrrol, pyrimidine, triazine, adenine, thiazole, thiouracil, rhodanine, thiazolidinthion, and pyrazole, as well as water-soluble polymers such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), hydroxypropylcellulose (HPC), carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose, surfactants, emulsifiers, lipids, oils, and polyesters. Among these organic compounds, water-soluble polymers such as hydroxypropylcellulose (HPC) are particularly preferred because they are highly safe for living organisms and easy to use for hand hygiene.

[0052] An antibiofilm agent (paint) for forming an antibiofilm coating can be manufactured, for example, as follows: First, a slurry containing particles of a monovalent copper compound is prepared. The slurry can be formed by adding a powder of a monovalent copper compound and necessary additives to ethanol. Then, the slurry is diluted with water and ethanol to which an organic compound has been added, and the antibiofilm agent can be manufactured by adjusting the concentration of each component to a suitable level. An antibiofilm coating can be formed by applying the prepared antibiofilm agent to the object using an appropriate method. Any appropriate method can be used for application, but for example, spin coating, dip coating, spray coating, cast coating, bar coating, microgravure coating, and gravure coating can be used.

[0053] Similar to the method used for antibiofilm sheets, a polarity ratio in the surface free energy of an antibiofilm coating (film) between 0.5% and 8.0% can further suppress the adhesion of biofilm to the coating. If the ratio is less than 0.5% or greater than 8.0%, bacteria and bacterial metabolites, which are components of biofilm, will adhere more easily, and their adhesion will be stronger. In the case of liquid paints containing solvents or water, the surface free energy of the coating is the surface free energy in the dried and hardened state, after the non-coating components (solvents, water, etc.) other than the coating components (organic compounds, copper compounds, etc.) have evaporated or decreased.

[0054] (Second embodiment) A second embodiment of the antibiofilm coating agent will be described. The antibiofilm coating agent of this embodiment is a coating agent that can be applied to a location where antibiofilm properties are desired, forming a film with antibiofilm properties. In other words, the antibiofilm coating agent is not limited to coloring paints such as paints, but is a coating agent that can form any film with antibiofilm properties. The antibiofilm coating agent of this embodiment can set the polarity ratio in terms of surface free energy of the coating film (film) surface formed using the coating agent to 0.5% or more and 8.0% or less. The antibiofilm coating agent of this embodiment contains additives having a surface conditioning function (surface conditioning agent, hydrophilic agent, water-repellent / oil-repellent agent), so that when applied to form a coating film, a coating film with the above-mentioned polarity ratio can be obtained. Furthermore, the coating film formed using the antibiofilm coating agent of this embodiment is also the antibiofilm composition of the first embodiment.

[0055] The antibiofilm coating, like the antibiofilm sheet of the first embodiment, contains a monovalent copper compound and an organic compound. It may also contain additives as needed. The form of the coating is not particularly limited; it may be a liquid or a powder. In the case of a liquid coating, it may include solvent-based coatings or water-based coatings. Various organic compounds can be used in the antibiofilm coating, but in this embodiment, the case of a resin will be described.

[0056] Monovalent copper compounds function as antimicrobial agents in antibiofilm coatings. The same copper compounds as in the first embodiment can be used as the monovalent copper compound. As in the first embodiment, CuI is preferred.

[0057] The monovalent copper compound may be contained in the anti-biofilm coating in a particulate dispersion. The particle size of the monovalent copper compound is not particularly limited and can be appropriately determined by those skilled in the art. For example, a monovalent copper compound with an average particle size of 1 nm or more and less than 1 μm can be used, as in the first embodiment.

[0058] Monovalent copper compounds can be included in antibiofilm coatings in appropriate amounts. For example, they can be included in a mass fraction of 0.5% to 30% of the total antibiofilm coating. Including them within this range allows for maintaining the strength of the coating film while minimizing the impact on water contact and obtaining sufficient antibiofilm performance. If the amount is less than 0.5%, sufficient antibiofilm properties will not be achieved. If it exceeds 30%, the strength of the antibiofilm coating film decreases or the antibiofilm effect becomes saturated, so 30% or less is preferable.

[0059] The base resin is the material that forms the framework of the coating film. Any base resin whose polarity ratio can be adjusted by additives is acceptable. Specifically, thermoplastic resins, thermosetting resins, and radiation-curable resins are used as base resins.

[0060] Examples of thermoplastic resins include olefin resins such as polyethylene, polypropylene, and chlorinated polyethylene; polystyrene resins, polyvinyl acetate resins, polyurethane resins, polyester resins; copolymers with acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters as the main chain; acrylic styrene resins; fluorine-based resins; cellulose-based resins such as nitrated cotton and ethylcellulose; drying oils such as castor oil, linseed oil, and tung oil; and natural resins such as shellac and copal.

[0061] Examples of thermosetting resins include phenolic resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, acrylic silicone resins, alkyd resins, polyurethane resins, thermosetting acrylic resins, and thermosetting polyimide resins.

[0062] Radiation-curable resins are resins that harden when irradiated with electron beams, ultraviolet light, or other light sources. Radiation-curable resins include monomers, oligomers, or polymers, and polyfunctional (meth)acrylate compounds such as polyfunctional (meth)acrylate monomers, polyfunctional (meth)acrylate oligomers, or polyfunctional (meth)acrylate polymers are preferred from the viewpoint of being able to increase the crosslinking density after curing, thereby improving the surface hardness and transparency. Examples of polyfunctional (meth)acrylate monomers include bifunctional (meth)acrylate monomers such as ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, allyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dioxane glycol di(meth)acrylate, ethoxylated (2) bisphenol A di(meth)acrylate, ethoxylated (3) bisphenol A di(meth)acrylate, ethoxylated (4) bisphenol A (meth)acrylate, ethoxylated (10) bisphenol A di(meth)acrylate, propoxylated (3) bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and 9,9-bis[4-(2-hydroxyethoxy)phenyl]ful orange (meth)acrylate;Glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (3) trimethylolpropane triacrylate, ethoxylated (6) trimethylolpropane triacrylate, ethoxylated (9) trimethylolpropane triacrylate, propoxylated (3) trimethylolpropane triacrylate, propoxylated (6) trimethylolpropane triacrylate, propoxylated (9) trimethylolpropane triacrylate, pentaerythritol tri(meth)acrylate, ethoxylated (4) pentaerythritol tri(meth)acrylate, ethoxylated (8) pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, caprolactone modified (1) tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, caprolactone Trifunctional (meth)acrylate monomers such as (3) modified tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate; pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, tripentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated (4) pentaerythritol tetra(meth)acrylate, ethoxylated (8) pentaerythritol tetra(meth)acrylate; pentafunctional (meth)acrylate monomers such as dipentaerythritol penta(meth)acrylate, tripentaerythritol penta(meth)acrylate; hexafunctional (meth)acrylate monomers such as dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate;Seven- or more functional (meth)acrylate monomers can be used, such as tripentaerythritol hepta(meth)acrylate and tripentaerythritol octa(meth)acrylate. Examples of polyfunctional (meth)acrylate oligomers and polyfunctional (meth)acrylate polymers include pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycerol di(meth)acrylate, and alkylene oxide-modified or lactone-modified compounds obtained by adding ethylene oxide, propylene oxide, ε-caprolactone, γ-butyrolactone, etc. to these, as well as isocyanate ethyl acrylate, isocyanate propyl acrylate, and active hydrogen-containing polymerizable monomers such as hydroxyethyl acrylate, along with hexamethylene diisocyanate, etc. Acrylic (meth)acrylates such as urethane (meth)acrylates obtained by adding polyisocyanate compounds to unsaturated compounds, urethane-urea (meth)acrylates having urea bonds, compounds obtained by adding (meth)acrylic acid to acrylic resin copolymerized with glycidyl methacrylate, compounds obtained by adding 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, pentaerythritol tri(meth)acrylate, etc. to acrylic resin copolymerized with 2-acryloyloxyethyl isocyanate, and resins obtained by adding 2-acryloyloxyethyl isocyanate to acrylic resin copolymerized with hydroxyl group-containing monomers can be used.

[0063] Furthermore, photopolymerization initiators may be added to radiation-curable resins as needed. Examples of photopolymerization initiators include anthraquinone, acetophenone, isopropylbenzoin ether, isobutylbenzoin ether, ethylanthraquinone, carbazole, xanthone, 4-chlorobenzophenone, o-benzoylmethylbenzoate, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,2-dimethoxy-1,2-diphenylethane-1-one, p-dimethylaminobenzoate isoamyl ester, p-dimethylaminobenzoate ethyl ester, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-H Examples include droxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1(4-morpholinophenyl)-butanone-1, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, methylbenzylformate, fluorenone, benzophenone, benzaldehyde, fluorene, triphenylamine, Michler ketone, 3-methylacetophenone, 2-methyl-1-1[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide.

[0064] As an organic compound other than resin, an organic compound can be used that can form a film and retain the monovalent copper compound on the surface of the object even after the solvent such as alcohol or water contained in the paint has dried away. Such an organic compound can be appropriately selected depending on the type of monovalent copper compound, but it is particularly preferable to use an organic compound that can suppress the oxidation of the monovalent copper compound. Examples of organic compounds that can suppress the oxidation of the monovalent copper compound include benzotriazole (BTA), mercaptobenzothiazole (MBT), benzothiazole, benzoxazole, tritriazole (TTA), 2·5-dimercaptothiadiazole (DMTDA), benzimidazole (BIA), benzimidazolethiol (BIT), benzoxazolethiol (BOT), methylbenzothiazole, methylbenzotriazole, indole, indazole, mercaptothiazoline, dithiocarbamic acid and its derivatives, and thiouracil. Examples include inhibitors such as thiobarbituric acid (TBA), imidazoline, pyrrol, pyrimidine, triazine, adenine, thiazole, thiouracil, rhodanine, thiazolidinthion, and pyrazole, as well as water-soluble polymers such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), hydroxypropylcellulose (HPC), carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose, surfactants, emulsifiers, lipids, oils, and polyesters. Among these organic compounds, water-soluble polymers such as hydroxypropylcellulose (HPC) are particularly preferred because they are highly safe for living organisms and easy to use for hand hygiene.

[0065] Furthermore, the additives may include those with surface-modifying properties to adjust the polarity of the components. Specifically, these may include surface modifiers, hydrophilic agents, and water-repellent / oil-repellent agents.

[0066] Furthermore, antibiofilm coatings may contain various additives. The additives can be appropriate depending on the application and purpose of the antibiofilm coating. Examples of additives include flame retardants, flame retardant enhancers, stabilizers, UV absorbers, plasticizers, and lubricants. Pigments, fillers, and other components may also be added as appropriate. Additionally, other additives such as antibacterial compositions, antiviral compositions, antifungal compositions, anti-allergen compositions, catalysts, anti-reflective materials, and materials with heat-shielding properties may be added, in addition to monovalent copper compounds.

[0067] The polarity ratio in the surface free energy of the coating (film) formed by applying the anti-biofilm coating of this embodiment can be 0.5% or more and 8.0% or less. The polarity ratio can be similarly determined for the coating using the method described in the first embodiment. When the polarity ratio in the surface free energy of the coating formed by the anti-biofilm coating is 0.5% or more and 8.0% or less, the adhesion of biofilm to the coating can be further suppressed. If it is less than 0.5% or greater than 8.0%, bacteria and bacterial metabolites, which are components of biofilm, will adhere more easily, and the adhesion force will also be stronger. In the case of a liquid coating containing solvents or water, the surface free energy of the coating is the surface free energy in the dried and hardened state, after the non-coating components (solvents, water, etc.) other than the coating components (resin, copper compounds, etc.) that make up the coating have evaporated and disappeared or decreased.

[0068] The coating film formed by applying the anti-biofilm coating of this embodiment preferably has a water contact angle of 90° to 99°. This range further suppresses the adhesion of biofilm to the coating film. If the water contact angle is less than 90° or greater than 99°, bacteria and bacterial metabolites, which are components of biofilm, adhere more easily, and their adhesion strength also increases.

[0069] According to the antibiofilm coating of this embodiment, it is possible to achieve an antibiofilm activity value of 50% or more, as evaluated by the antibiofilm properties test (ISO 4768) of the formed coating film, and to form a coating film with excellent antibiofilm properties.

[0070] Next, the method for manufacturing the antibiofilm coating of this embodiment will be described. First, the antibiofilm coating of this embodiment can be manufactured by mixing fine particles or slurry of a monovalent copper compound, whose particle size has been adjusted to the above range by pulverization, wet dispersion, etc., with a base resin in a solvent. Furthermore, by adding and mixing additives as needed, a coating containing additives can be obtained. Note that the method for manufacturing antibiofilm coatings using organic compounds other than resins can be described in the first embodiment.

[0071] The antibiofilm coating of this embodiment can be applied to an object by any appropriate method. For example, spin coating, dip coating, spray coating, cast coating, bar coating, microgravure coating, and gravure coating methods can be used.

[0072] According to the above embodiment, an antibiofilm coating that can suppress the adhesion of biofilms can be obtained. Furthermore, by having a polarity ratio in the surface free energy of the coating film formed by applying the antibiofilm coating that is between 0.5% and 8.0% as described above, an antibiofilm coating that can more reliably suppress the adhesion of biofilms can be obtained. Specifically, an antibiofilm coating can be obtained that can form a coating film with excellent antibiofilm properties, such as an antibiofilm activity value of 50% or more as confirmed by the antibiofilm activity test (ISO 4768).

[0073] The antibiofilm coating of this embodiment can suppress the formation of biofilms formed by various microorganisms through its coating film. This is because the monovalent copper compound, which is an antibacterial component, exhibits antibacterial activity against a wide range of bacteria regardless of whether they are Gram-positive or Gram-negative, and the radicals it generates oxidize bacterial metabolites (polysaccharides, proteins, lipids, nucleic acids, etc.) that are components of the biofilm. Microorganisms whose biofilm formation can be suppressed by the antibiofilm coating of this embodiment include, for example, Escherichia coli, Pseudomonas aeruginosa, Salmonella, Klebsiella pneumoniae, Moraxella, Vibrio parahaemolyticus, Legionella, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus, Methylobacterium, and Rhodotor. In all cases, their adhesion can be suppressed by the antibacterial function of the monovalent copper compound contained in the antibacterial coating.

[0074] The antibiofilm coating of this embodiment can suppress the growth of biofilm by, for example, applying it to the drain pan of the aforementioned air conditioning equipment. Furthermore, in some cases, it may be difficult to attach an antibiofilm sheet to the surface of heat exchangers or filtration membranes in water treatment equipment in order to maintain their heat exchange and filtration functions. Even in such cases, the antibiofilm coating can be applied to the surface of the heat exchanger or filtration membrane to suppress the growth of antibiofilm while maintaining the heat exchange and filtration functions. [Examples]

[0075] <Preparation of antibiofilm sheets> Samples of antibiofilm sheets No. 1-1 to 1-9 shown in Table 1 were actually prepared, and tests were conducted to evaluate their antibiofilm properties. Each sample was prepared as follows:

[0076] (Exam No. 1-1) For sample No. 1-1, a functional polypropylene (PP) masterbatch (functional agent PPMB) and an additive masterbatch (additive MB) 1 were first prepared. For the functional agent PP masterbatch, commercially available copper(I) iodide powder (manufactured by Nippon Chemical Industrial Co., Ltd.) was pulverized to an average particle size of 150 nm using a dry grinding device, NanoJetmizer (manufactured by Aisin Nanotechnologies Corporation, NJ-100B), to obtain copper iodide particles. A mixture was prepared by adding polypropylene (PP) resin pellets (manufactured by Prime Polymer Co., Ltd.), which is the base resin, so that the copper iodide particles in the masterbatch were 12% by mass fraction, the zirconium oxide and fatty acid ester as dispersants were 18% and 7% by mass fraction, respectively, and polyvinylpyrrolidone as an additive was 12% by mass fraction. The resulting mixture was then supplied to a twin-screw melt kneader to obtain the functional agent PP masterbatch. Furthermore, polyvinylpyrrolidone and a cationic surfactant were added as additives at mass fractions of 20% and 2%, respectively, to polypropylene (PP) resin pellets, which served as the base resin homopolymer. A mixture was prepared by adding these to the base resin homopolymer, polypropylene (PP) resin pellets, and supplying the resulting mixture to a twin-screw fusion kneader to obtain additive masterbatch 1. Functional agent PP masterbatch was added at a mass fraction of 8%, and additive masterbatch 1 at a mass fraction of 10%, and the mixture was kneaded in the kneader. A sheet with a thickness of 100 μm was then formed using a T-die extrusion molding machine to obtain a sample of antibiofilm sheet No. 1-1. The copper iodide concentration in this entire sheet was 0.96%.

[0077] (Exam No. 1-2) Samples No. 1-2 were prepared in the same manner as No. 1-1, except that the functional agent PP masterbatch was 4.4% and the additive masterbatch was 5.6%. The total copper iodide concentration in this sheet was 0.53%.

[0078] (Exam No. 1-3) Samples No. 1-3 were prepared in the same manner as No. 1-1, except that the functional agent PP masterbatch was 4.4%, the additive masterbatch was 5.6%, and polyethylene glycol (PEG) was added as another additive at 1%. The total copper iodide concentration in this sheet was 0.53%.

[0079] (Exam No. 1-4) Samples No. 1-4 were prepared in the same manner as No. 1-1, except that the functional agent PP masterbatch was 8% and the additive masterbatch was 20%. The total copper iodide concentration in this sheet was 0.96%.

[0080] (Exam No. 1-5) Samples No. 1-5 were prepared in the same manner as No. 1-1, except that the functional agent PP masterbatch was 8% and the additive masterbatch was 5%. The total copper iodide concentration in this sheet was 0.96%.

[0081] (Exam No. 1-6) Samples No. 1-6 were prepared in the same manner as No. 1-1, except that the functional agent PP masterbatch was 8.9% and the additive masterbatch was 11.1%, to create the antibiofilm sheet samples. The total copper iodide concentration for this sheet was 0.96%.

[0082] (Exam No. 1-7) For samples No. 1-7, a functional polyethylene (PE) masterbatch (functional PEMB) and an additive masterbatch 2 were prepared. For the functional PE masterbatch, commercially available copper(I) iodide powder (manufactured by Nippon Chemical Industrial Co., Ltd.) was pulverized to an average particle size of 150 nm using a dry grinding device, the NanoJetmizer (manufactured by Aisin Nanotechnologies Corporation, NJ-100B), to obtain copper iodide particles. The obtained copper iodide particles were mixed with a metal soap as a dispersant to prevent aggregation of the copper iodide particles. A mixture was prepared by adding polyethylene (PE) resin pellets (manufactured by Asahi Kasei Chemicals Corporation) as the base resin so that the copper iodide particles mixed with the dispersant constituted 40% by mass of the entire masterbatch pellet. The resulting mixture was supplied to a twin-screw melt kneader to obtain functional PE masterbatch pellets. Furthermore, an O / W emulsion containing a nonionic surfactant was added as an additive at a mass fraction of 20% to polypropylene (PP) resin pellets, which served as the base resin, to prepare a mixture. The resulting mixture was supplied to a twin-screw melt mixer to obtain additive masterbatch 2. Functional agent PE masterbatch was added at a mass fraction of 10%, and additive masterbatch 2 was added at a mass fraction of 10% to the PP pellets (homopolymer), and the mixture was kneaded in the mixer. Then, a sheet with a thickness of 100 μm was formed using a T-die extruder to obtain samples of antibiofilm sheets No. 1-7. The copper iodide concentration in the entire sheet was 4.0%.

[0083] (Exam No. 1-8) Samples No. 1-8 were prepared in the same manner as No. 1-4, except that the PP pellets used as the base resin during film molding were replaced with a block copolymer, to create the antibiofilm sheet samples. The copper iodide concentration for the entire sheet was 0.96%.

[0084] (Exam No. 1-9) Samples No. 1-9 were prepared in the same manner as No. 1-1, except that the PP pellets used as the base resin during film molding were replaced with a block copolymer, to create the antibiofilm sheet samples. The total copper iodide concentration in this sheet was 0.96%.

[0085] (Measurement of Cu elution amount) For each sample of the prepared antibiofilm sheet, copper ions (Cu) were eluted when the sample was immersed in 1 / 5 TSB medium for 48 hours. + The amount of eluted material was measured. Specifically, a 20mm x 40mm test piece was cut out, placed in a test tube, and 1 / 5 TSB medium warmed to 35°C was added. After standing for 48 hours, the amount of Cu was measured using an atomic absorption spectrophotometer.

[0086] (Measurement of contact angle) For each sample, the contact angle between water and diiodomethane was measured. Specifically, the measurement was performed using a contact angle meter (Drop Master300 solid-liquid interface analyzer, manufactured by Kyowa Interface Science Co., Ltd.).

[0087] (Calculation of surface free energy and polarity ratio in surface free energy) For each sample, the contact angle between water and diiodomethane was measured, and the dispersion component γsd and polar component γsp of the surface free energy were calculated using equation (3) described in the embodiment. Then, the surface free energy γs of the sample and the polarity ratio Rγp at its surface free energy were calculated using equations (1) and (2) described in the embodiment.

[0088] (Anti-biofilm test) For each sample, an antibiofilm test was performed according to the method specified in ISO 4768. Specifically, a 30 × 30 mm flat test specimen was prepared from the antibiofilm sheet sample and attached to a 40 × 40 mm glass plate. The test specimen and glass plate were placed in a sterile container, the test bacterial suspension was added, and the container containing the test specimen and glass plate was incubated at 35°C for 48 hours. The test bacterial suspension used was Staphylococcus epidermidis ATCC 35984. After incubation, the specimen was washed to remove any cells not fixed to the specimen and any components of the growth medium. After washing and drying, it was stained with crystal violet (CV) solution for 30 minutes. After washing to remove excess CV solution, the biofilm on the specimen was wiped off with a water-soluble nonwoven fabric and collected, then dissolved in 1% sodium dodecyl sulfate. The absorbance of the dissolved solution at 590 nm was measured using a spectrophotometer. Using the obtained absorbance, the antibiofilm activity value R(%) was calculated using the following equation (4). R = (1 - A / B) × 100 (4) R: Antibiofilm activity value A: Average absorbance of the processed product at 590 nm after 48 hours B: Average absorbance at 590 nm of the unprocessed product after 48 hours.

[0089] Table 1 shows the composition of each sample and the test results described above.

[0090] [Table 1]

[0091] The antibiofilm sheet samples from Tests No. 1-1 to 1-4, which had a polarity ratio of 0.5% to 8.0%, all showed antibiofilm activity values ​​of 50% or higher, confirming excellent antibiofilm performance. The water contact angle of these samples was in the range of 90° to 99°. On the other hand, Tests No. 1-5 to 1-9 had polarity ratios greater than 8.0% or less than 0.5%, and all showed antibiofilm activity values ​​of less than 50%, failing to achieve sufficient antibiofilm performance.

[0092] Furthermore, despite the higher amount of Cu eluted from CuI, which possesses antimicrobial properties such as antibacterial and antiviral effects, tests No. 1-7 and 1-8 yielded significantly lower antibiofilm activity values ​​than tests No. 1-1 to 1-5. Therefore, it was confirmed that simply having high antibacterial or antiviral properties does not necessarily guarantee antibiofilm performance.

[0093] <Preparation of antibiofilm coatings> Samples of the antibiofilm coatings No. 2-1 to 2-4 shown in Table 2 were actually prepared, and tests were conducted to evaluate their antibiofilm properties. Each sample was prepared as follows.

[0094] (Exam No. 2-1) 17 parts by mass of specific fermented alcohol, 28 parts by mass of propylene glycol monomethyl ether, 31 parts by mass of acrylic acrylate (manufactured by DIC Corporation), 4 parts by mass of trifunctional acrylate monomer (manufactured by Daicel Ornex Corporation), a polyfunctional acrylate compound used as a base resin, and 20 parts by mass of Cufitec powder B (manufactured by NBC Meshtec Corporation), which contains monovalent copper compound particles (CuI), were measured out and uniformly stirred in a beaker to form a paint. Next, 40 parts by mass of ethanol and 60 parts by mass of propylene glycol monomethyl ether were mixed to form a diluent solvent. The paint and diluent solvent were blended in a ratio of 1:3 and applied to a PET substrate, Lumirror 125-T60 (manufactured by Toray Industries, Inc.), using a bar coater (#5), and dried at 50°C for 60 seconds. Electron beam irradiation was performed using an electron beam irradiation device ERECTOROBEAM-L EC250 / 15 / 180L (manufactured by Iwasaki Electric Co., Ltd.). The irradiation conditions were an acceleration voltage of 150kV, a current of 5mA, and a dose of 110kGy.

[0095] (Exam No. 2-2) 20 parts by mass of specific fermented alcohol, 34 parts by mass of propylene glycol monomethyl ether, 31 parts by mass of acrylic acrylate (manufactured by DIC Corporation), 4 parts by mass of trifunctional acrylate monomer (manufactured by Daicel Ornex Corporation) as a base resin, 1 part by mass of alkylphenone-based photopolymerization initiator (BASF Japan Ltd.), and 10 parts by mass of Cufitec Powder B (manufactured by NBC Meshtec Co., Ltd.) were measured out and uniformly stirred in a beaker to form a paint. Next, 40 parts by mass of ethanol and 60 parts by mass of propylene glycol monoethyl ether were mixed to form a diluent. The paint and diluent were blended in a ratio of 1:3 and applied to a PET substrate, Lumirror 125-T60 (manufactured by Toray Industries, Inc.), using a bar coater (#5), and dried at 50°C for 60 seconds. UV irradiation was performed using a UV irradiation device ECS-1511U (manufactured by Iwasaki Electric Field Co., Ltd.). The irradiation conditions were a lamp output of 1.5 kW and an integrated light intensity of 157.59 mJ / cm². 2 So, I had it irradiated twice.

[0096] (Exam No. 2-3) 12 parts by mass of specific fermented alcohol (manufactured by Daiichi Alcohol Co., Ltd.), 18 parts by mass of 2-ethoxyethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1 part by mass of nonionic surfactant (manufactured by Nikko Chemicals Co., Ltd.), 4 parts by mass of polyfunctional acrylate (manufactured by Toagosei Co., Ltd.) as a base resin, 26 parts by mass of urethane acrylate (manufactured by Negami Kogyo Co., Ltd.), 1 part by mass of alkylphenone-based photopolymerization initiator (manufactured by Lambson Japan Co., Ltd.), and 38 parts by mass of Cufitec dispersion alcohol-based BB2-ANA01 (manufactured by NBC Meshtec Co., Ltd.) containing monovalent copper compound particles (CuI) were measured out and uniformly stirred in a beaker to make a paint. The CuI concentration in the paint was approximately 2.8%. The obtained paint was applied to a PET substrate Lumirror 125-T60 (manufactured by Toray Industries, Inc.) using a bar coater (#20), dried, and an antibacterial / antiviral coated sheet was obtained.

[0097] (Exam No. 2-4) 83.6 parts by mass of denatured ethanol (Imazu Pharmaceutical Co., Ltd.), 16.0 parts by mass of Cufitec dispersion alcohol-based AA1-ANA02 (manufactured by NBC Mesh Tech Co., Ltd.) containing monovalent copper compound particles (CuI), 0.1 parts by mass of alkylsilane (manufactured by Shin-Etsu Chemical Co., Ltd.) as a binder instead of a base resin, and 0.3 parts by mass of fluoroalkylsilane (Evonik Industries AG) as a water repellent were measured out and uniformly stirred in a beaker to form a paint. The CuI concentration in the paint was approximately 0.4%. This was dipped into polyester mesh T-120T (manufactured by NBC Mesh Tech Co., Ltd.) and dried at 130°C for 3 minutes.

[0098] (Measurement of Cu elution amount) For each sample of the prepared antibiofilm sheet, copper ions (Cu) were eluted when the sample was immersed in 1 / 5 TSB medium for 48 hours. + The amount of eluted material was measured. Specifically, a 20mm x 40mm test piece was cut from the sample, placed in a test tube, and 1 / 5 TSB medium warmed to 35°C was added. After standing for 48 hours, the amount of Cu was measured using an atomic absorption spectrophotometer.

[0099] (Measurement of contact angle) For each sample, the contact angle between water and diiodomethane was measured. Specifically, the measurement was performed using a contact angle meter (Drop Master300 solid-liquid interface analyzer, manufactured by Kyowa Interface Science Co., Ltd.).

[0100] (Calculation of surface free energy and polarity ratio in surface free energy) In the same manner as the tests for the antibiofilm sheets described above, the surface free energy γs and the polarity ratio Rγp at that surface free energy were calculated using the contact angle measured for the coating film samples.

[0101] (Anti-biofilm test) For each sample, test specimens coated with paint were subjected to antibiofilm testing according to the method specified in ISO 4768. Specifically, flat 30 mm x 30 mm test specimens were prepared from sheets coated with the sample paint. Using these test specimens, the antibiofilm activity value R(%) was determined in the same manner as for the antibiofilm sheets.

[0102] The composition of each sample and the test results are shown in Table 2.

[0103] [Table 2]

[0104] The coatings formed using the paints from Tests No. 2-1 and 2-2, which had a polarity ratio of 0.5% to 8.0%, all exhibited antibiofilm activity values ​​of 50% or higher, confirming excellent antibiofilm performance. The water contact angles of these coatings were in the range of 90° to 99°. On the other hand, in Tests No. 2-3 and 2-4, the polarity ratio of the coatings was greater than 8.0% or less than 0.5%, and in both cases, the antibiofilm activity values ​​were less than 50%, failing to achieve sufficient antibiofilm performance.

[0105] Furthermore, comparing tests No. 2-2 and 2-3, test No. 2-3 showed a higher amount of Cu eluted from CuI, which has antimicrobial properties, but obtained a significantly lower antibiofilm activity value than test No. 2-2. Therefore, it was confirmed that even if a paint has high antibacterial or antiviral properties, it does not necessarily mean that it will have antibiofilm performance.

Claims

1. A composition in which particles of a monovalent copper compound are dispersed in an organic compound, An antibiofilm composition characterized in that the polarity ratio in surface free energy, which is the ratio of the polar component to the sum of the dispersion component and the polar component of the surface free energy, is 0.5% or more and 8.0% or less.

2. The antibiofilm composition according to claim 1, characterized in that the monovalent copper compound is copper(I) iodide.

3. The antibiofilm composition according to claim 1, characterized in that the water contact angle is 90° or more and 99° or less.

4. The antibiofilm composition according to claim 1, characterized in that the organic compound is a resin.

5. The antibiofilm composition according to claim 4, characterized in that the resin is polypropylene.

6. The antibiofilm composition according to claim 5, characterized in that the polypropylene is a homopolymer.

7. The antibiofilm composition according to claim 1, characterized in that it is in the form of a sheet.

8. The antibiofilm composition according to claim 1, characterized in that it is a molded product formed by injection molding.

9. The antibiofilm composition according to claim 1, characterized in that it is a coating film.

10. The antibiofilm composition according to claim 9, characterized in that the organic compound is a water-soluble polymer.

11. The antibiofilm composition according to claim 10, characterized in that the water-soluble polymer is hydroxypropyl cellulose.

12. A paint containing monovalent copper compound particles, An antibiofilm coating characterized in that the polarity ratio in the surface free energy of the formed coating film, which is the ratio of the polar component to the sum of the dispersion component and the polar component, is 0.5% or more and 8.0% or less.

13. The antibiofilm coating according to claim 12, characterized in that the monovalent copper compound is copper(I) iodide.

14. The antibiofilm coating according to claim 12, characterized in that the water contact angle of the coating film is 90° or more and 99° or less.

15. The antibiofilm coating according to claim 12, characterized in that it contains a polyfunctional acrylate compound or a polyfunctional methacrylate compound as a base resin.

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