Method for producing coating agent and method for producing coating film

Abstract

Provided is a method for producing a coating agent, the method comprising heating a silver-containing glass-based antibacterial agent and mixing a curable resin ingredient, a solvent, and the silver-containing glass-based antibacterial agent having been heated. When the heating temperature and heating time in the heating are expressed by A [°C] and B [min], respectively, then A×B is 8,400 or greater.

Description

Coating agent manufacturing method and coating film manufacturing method

[0001] The present disclosure relates to a method for producing a coating agent and a method for producing a coating film.

[0002] In recent years, there has been an increasing demand for antibacterial and antiviral properties. One method for imparting antibacterial and antiviral properties to a component is to apply an antibacterial and antiviral coating agent. For example, Patent Document 1 discloses an antibacterial and antiviral coating agent containing silver-based inorganic particles.

[0003] Japanese Patent Application Laid-Open No. 2023-4856

[0004] In antibacterial and antiviral coating agents, improving the antibacterial and antiviral performance is important. For example, by improving the antibacterial and antiviral performance of the antibacterial agent used in the coating agent, the antibacterial and antiviral performance of the coating film formed from the coating agent can be maintained even when the amount of antibacterial agent added is reduced. Therefore, improving the antibacterial and antiviral performance of the antibacterial agent itself is useful from the perspective of maintaining optical properties when the coating agent is used for optical applications.

[0005] Therefore, the present disclosure provides a method for producing a coating agent that can improve antibacterial and antiviral performance.

[0006] A method for producing a coating agent according to one embodiment of the present disclosure includes: subjecting a silver-based glass antibacterial agent to a heat treatment; and mixing a curable resin component, a solvent, and the heat-treated silver-based glass antibacterial agent; wherein, when the heating temperature in the heat treatment is A [°C] and the heating time is B [min], A×B is 8400 or more.

[0007] Furthermore, a method for producing a coating film according to one aspect of the present disclosure includes applying the coating agent produced by the above-described method for producing a coating agent to a surface of a substrate, and curing the curable resin component.

[0008] According to the present disclosure, antibacterial and antiviral performance can be improved.

[0009] Fig. 1 is an enlarged image of a display when glare does not occur. Fig. 2 is an enlarged image of a display when glare occurs. Fig. 3 is a flowchart showing an example of a method for manufacturing a coating agent according to an embodiment. Fig. 4 is a flowchart showing an example of a method for manufacturing a coating film according to an embodiment. Fig. 5 is a diagram showing the relationship between the antiviral activity value of a coating film and the heat treatment conditions for heat treatment of a silver-based glass antibacterial agent.

[0010] (Summary of the Present Disclosure) As an overview of the present disclosure, examples of a method for producing a coating agent and a method for producing a coating film according to the present disclosure will be described below.

[0011] For example, a method for producing a coating agent according to the first aspect of the present disclosure includes subjecting a silver-based glass antibacterial agent to a heat treatment, and mixing a curable resin component, a solvent, and the heat-treated silver-based glass antibacterial agent, wherein, when the heating temperature in the heat treatment is A [°C] and the heating time is B [min], A×B is 8400 or more.

[0012] By subjecting the silver-based glass antibacterial agent to heat treatment, the antibacterial and antiviral performance of the silver-based glass antibacterial agent is improved, and the antibacterial and antiviral performance of the coating agent can be improved.

[0013] Furthermore, for example, a method for producing a coating agent according to a second aspect of the present disclosure is the method for producing a coating agent according to the first aspect, in which the heating temperature is 160° C. or higher.

[0014] This allows the heating time in the heat treatment to be shortened.

[0015] Furthermore, for example, a method for producing a coating agent according to a third aspect of the present disclosure is the method for producing a coating agent according to the first or second aspect, in which A×B is 9000 or more.

[0016] This can further improve the antibacterial and antiviral properties.

[0017] Furthermore, for example, a method for producing a coating agent according to a fourth aspect of the present disclosure is a method for producing a coating agent according to any one of the first to third aspects, wherein the curable resin component is photocurable.

[0018] This allows the coating agent to be cured without heating the substrate on which the coating agent is applied when forming a coating film using the coating agent.

[0019] Furthermore, for example, a method for manufacturing a coating agent according to a fifth aspect of the present disclosure is a method for manufacturing a coating agent according to any one of the first to fourth aspects, in which the content of the silver-based glass antibacterial agent in the solid content of the coating agent is 2 mass% or more.

[0020] This can further improve the antibacterial and antiviral properties.

[0021] Furthermore, for example, a method for producing a coating agent according to a sixth aspect of the present disclosure is the method for producing a coating agent according to the fifth aspect, in which the content is 6 mass % or less.

[0022] This can improve the optical properties of the coating film formed from the coating agent.

[0023] Furthermore, for example, a method for manufacturing a coating agent according to a seventh aspect of the present disclosure is a method for manufacturing a coating agent according to any one of the first to sixth aspects, in which the particle diameter of the silver-based glass antibacterial agent is 3 μm or less.

[0024] This can improve the optical properties of the coating film formed from the coating agent.

[0025] Furthermore, for example, a method for producing a coating film according to an eighth aspect of the present disclosure includes applying a coating agent produced by the method for producing a coating agent according to any one of the first to seventh aspects to a surface of a substrate, and curing the curable resin component.

[0026] As a result, a coating film with improved antibacterial and antiviral properties can be produced using the above coating agent.

[0027] The embodiment will be specifically described below.

[0028] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in the independent claims are described as optional components.

[0029] Furthermore, in this specification, terms indicating the relationship between elements, terms indicating the shape of elements, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0030] In addition, in this specification, "main component a" means that the content of a is greater than 50 mass %.

[0031] (Embodiment) A coating agent according to this embodiment and a coating film produced using this coating agent will be described below. The coating agent according to this embodiment is used, for example, as an antibacterial and antiviral hard coating agent. By applying the coating agent according to this embodiment to the surface of a substrate, an antibacterial and antiviral coating can be formed as a coating film. The substrate is appropriately selected as the object to which antibacterial and antiviral properties are to be imparted, and is not particularly limited. The coating film formed from the coating agent according to this embodiment also has excellent optical properties, making it suitable for optical applications. The coating film is used, for example, to coat displays such as touch panel displays. The coating film may also be used as an antibacterial and antiviral resin film or glass film.

[0032] [Coating Agent Components] First, the components contained in the coating agent according to this embodiment will be described. The coating agent according to this embodiment includes a silver-based glass antibacterial agent, a curable resin component, and a solvent. The coating agent according to this embodiment may further include other components in addition to the silver-based glass antibacterial agent, the curable resin component, and the solvent. Examples of such other components include various additives for coating agents. The coating agent according to this embodiment may further include, for example, a thixotropic agent and a leveling agent as such other components.

[0033] Each component of the coating agent will be described in detail below.

[0034] (1) Silver-based glass antibacterial agent A silver-based glass antibacterial agent is added to impart antibacterial and antiviral properties to a coating film formed from a coating agent. Generally, the use of an antibacterial agent can impart not only antibacterial properties but also antiviral properties. Furthermore, generally, the amount of antibacterial agent added must be increased more than the amount required to impart antiviral properties.

[0035] The silver-based glass antibacterial agent contains silver-based glass particles as a main component. The silver-based glass particles are composed of silver-containing phosphate glass. By using the silver-based glass particles, it is possible to impart antibacterial and antiviral properties to a coating film formed from a coating agent while suppressing a decrease in the optical properties of the coating film. The silver-based glass particles contain, for example, Ag as a component. ２ O, ZnO, CaO, B ２ O ３ and P ２ O ５ , or Ag ２ O, CaO, B ２ O ３ and P ２ O ５ An example of the composition formula of the silver-based glass particles is 2 / 9AgO.(P ２ O ５ ZnO) ｍ ・2(2CaO・3BaO ３ ) ｎ Here, m=10 and n=1.1 to 1.4.

[0036] Specific examples of silver-based glass antibacterial agents include Ion Pure (registered trademark) ZAF-HS and Ion Pure Hb manufactured by Ishizuka Glass Co., Ltd., and Million Guard (registered trademark) PG721F manufactured by Koa Glass Co., Ltd.

[0037] The silver-based glass antibacterial agent may contain components other than the silver-based glass particles, such as by-products in the production of the silver-based glass particles. Examples of components other than the silver-based glass particles include white carbon. White carbon is also called hydrated amorphous silica. The content of the silver-based glass particles in the silver-based glass antibacterial agent is, for example, 90% by mass or more. The content of the silver-based glass particles in the silver-based glass antibacterial agent may be 95% by mass or more.

[0038] The content of the silver-based glass antibacterial agent in the solid content of the coating agent is, for example, 2% by mass or more. This can enhance the antibacterial and antiviral performance of the coating agent. Here, the solid content refers to components other than the solvent in the coating agent, and is the component that remains when a coating film is formed using the coating agent. The content of the silver-based glass antibacterial agent in the solid content of the coating agent may be 4% by mass or more.

[0039] The content of the silver-based glass antibacterial agent in the solid content of the coating agent is, for example, 6% by mass or less. This allows the coating film to maintain a high level of light transmittance and suppress glare, thereby improving the optical properties of the coating film. Here, glare (sparkling) refers to a phenomenon in which, when a coating film is formed on the surface of a display, variations in brightness are visible in the coating film due to scattering and refraction of light incident on the coating film. Glare, for example, can impair the visibility of the display. Figure 1 is an enlarged image of a display without glare. Figure 2 is an enlarged image of a display with glare. Figures 1 and 2 are images taken using a microscope with the film attached to an organic EL display and the display set to white. The film used to capture the image in Figure 1 corresponds to a coating film formed using a coating agent containing 4.1% by mass of silver-based glass antibacterial agent with a particle diameter of 1 μm in the solid content. As shown in Figure 1, when glare does not occur, only the light spots of each pixel are observed. On the other hand, when glare occurs, as shown in Figure 2, areas with high brightness are observed in addition to the light spots of each pixel.

[0040] The particle diameter of the silver-based glass antibacterial agent is, for example, 3 μm or less. This can suppress the occurrence of glare on the coating film. The particle diameter of the silver-based glass antibacterial agent is the median diameter D50. The median diameter D50 is the particle diameter at which the cumulative volume reaches 50% when the total cumulative volume of the silver-based glass antibacterial agent is taken as 100%, and the particle diameter is counted from the smallest particle diameter in the particle size distribution. The median diameter D50 can be calculated, for example, from the particle size distribution measured using a particle size distribution meter or the particle size distribution obtained by performing image processing on an electron microscope photograph. Furthermore, from the viewpoint of handleability, etc., the particle diameter of the silver-based glass antibacterial agent may be 0.2 μm or more, 0.5 μm or more, or 1 μm or more.

[0041] (2) Curable Resin Component The curable resin component is the main component of the solid content of the coating agent. The content of the curable resin component in the solid content of the coating agent is, for example, 70% by mass or more, and may be 80% by mass or more. Examples of resins formed by the curable resin component include acrylic resins, silicone resins, epoxy resins, and urethane resins. The curable resin component is, for example, photocurable. The light is, for example, ultraviolet light. Since the curable resin component is photocurable, it can be cured without heating the substrate. The curable resin component may be thermosetting. When the curable resin component is thermosetting, the curing temperature of the curable resin component may be 100°C or less, or may be 80°C or less, from the viewpoint of reducing the thermal influence on the substrate during curing. Furthermore, the curing temperature of the curable resin component is, for example, 20°C or more.

[0042] The curable resin component includes a resin raw material and a polymerization initiator. The resin raw material is a monomer or polymer containing a reactive functional group. The curable resin component may use one type of resin raw material, or two or more types of resin raw materials in combination. Similarly, the curable resin component may use one type of polymerization initiator, or two or more types of polymerization initiators in combination. The resin raw material and the polymerization initiator are not particularly limited as long as they are selected according to the type of resin formed by the curable resin component. When the curable resin component is photocurable, the polymerization initiator is a photopolymerization initiator.

[0043] The curable resin component may be a component for forming an acrylic resin from the viewpoint of improving the optical properties of the coating film. Hereinafter, the resin raw material and the photopolymerization initiator for forming the acrylic resin will be described in detail.

[0044] The resin raw material includes, for example, a polyfunctional acrylic monomer. The polyfunctional acrylic monomer is a monomer that reacts when irradiated with light, and includes, for example, multiple acrylates or multiple methacrylates in the molecule. The polyfunctional acrylic monomer may include multiple acrylates in the molecule from the viewpoint of photoreactivity. Specific examples of the polyfunctional acrylic monomer include acrylate compounds such as trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. From the viewpoint of the hardness and abrasion resistance of the coating film, the polyfunctional acrylic monomer may be dipentaerythritol hexaacrylate.

[0045] The content of the polyfunctional acrylic monomer in the resin raw material is, for example, 60% or more, and may be 70% or more.

[0046] The resin raw material may further contain an unsaturated group-containing acrylic copolymer. When the resin raw material further contains an unsaturated group-containing acrylic copolymer, discoloration such as yellowing of the coating film can be suppressed. Furthermore, when the resin raw material further contains an unsaturated group-containing acrylic copolymer, the adhesion of the coating film to the substrate and the flexibility of the coating film can be improved. Furthermore, the resin raw material may contain methyl methacrylate or the like as a residue that may be contained in the formation of the unsaturated group-containing acrylic copolymer.

[0047] The unsaturated group-containing acrylic copolymer is formed by copolymerizing a (meth)acrylate monomer with a (meth)acrylate monomer having a carboxyl group.

[0048] Examples of (meth)acrylate monomers include benzyl methacrylate, benzyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxypolyethylene glycol acrylate, phenoxypolyethylene glycol methacrylate, styrene, nonylphenoxypolyethylene glycol monoacrylate, nonylphenoxypolyethylene glycol monomethacrylate, nonylphenoxypolypropylene monoacrylate, nonylphenoxypolypropylene monomethacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, i-propyl acrylate, i-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, acrylate, i-butyl acrylate, i-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 3-ethylhexyl acrylate, ethylene glycol monoacrylate, ethylene glycol monomethacrylate, glycerol acrylate, glycerol methacrylate, glycerin monoacrylate, glycerin monomethacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, tetrahydrofurfuryl acrylate, and tetrahydrofurfuryl methacrylate.The (meth)acrylate monomers may be used alone or in combination of two or more kinds, as required.

[0049] Examples of the (meth)acrylate monomer having a carboxyl group include acrylic acid, methacrylic acid, as well as acrylic acid dimer, crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and reaction products of polybasic acids with hydroxyalkyl (meth)acrylates. The (meth)acrylate monomer having a carboxyl group may be used alone or in combination of two or more types, as needed.

[0050] A specific example of the unsaturated group-containing acrylic copolymer is a copolymer of benzyl methacrylate and methacrylic acid in a mass ratio of 80:20.

[0051] The unsaturated group-containing acrylic copolymer has an acid value of, for example, 100 mgKOH / g or more and 150 mgKOH / g or less, and a weight average molecular weight of, for example, 15,000 or more and 25,000 or less.

[0052] Photopolymerization initiators are used to react with resin raw materials under ultraviolet light and cure the resin raw materials. Examples of photopolymerization initiators that can be used include 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4'-methylthio-2-morpholinopropiophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime, etc.

[0053] From the viewpoint of curability and transparency, at least one of 1-hydroxycyclohexyl phenyl ketone and 2-methyl-4'-methylthio-2-morpholinopropiophenone may be used as the photopolymerization initiator, or both of these may be used.

[0054] The curable resin component may further contain a photopolymerization initiation aid, such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, or 1-chloro-4-propoxythioxant-9-one.

[0055] (3) Solvent The solvent dissolves the curable resin component and disperses the silver-based glass antibacterial agent. Examples of the solvent include hydrocarbon solvents such as n-hexane, benzene, toluene, and xylene; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as diethyl ether, tetrahydrofuran, and dipropylene glycol monomethyl ether; alcohol solvents such as ethanol, n-propanol, i-propanol, n-butanol, and t-butanol; and halogenated solvents such as dichloromethane, chloroform, carbon tetrachloride, and 1,2-dichloroethane. A single solvent may be used, or two or more solvents may be used in combination. From the viewpoints of volatility and solubility of the resin raw materials, at least one of methyl ethyl ketone and methyl isobutyl ketone may be used as the solvent.

[0056] (4) Thixotropic Agent A thixotropic agent is added to adjust the viscosity of the coating agent. By adding a thixotropic agent, it is possible to form fine wave-shaped irregularities on the surface of the coating film with a surface roughness Ra of about 0.1 μm.

[0057] Examples of thixotropic agents include acrylic viscosity modifiers, polyethylene viscosity modifiers, polyamide viscosity modifiers, polyether viscosity modifiers such as polyethers and urethane-modified polyethers, and cellulose viscosity modifiers such as hydroxyethyl cellulose, methyl cellulose, hydroxyethyl cellulose, and modified methyl cellulose. As the thixotropic agent, one type of thixotropic agent may be used, or two or more types of thixotropic agents may be used in combination. From the viewpoint of maintaining the light transmittance of the coating film, a cellulose viscosity modifier such as cellulose acetopropionate may be used as the thixotropic agent.

[0058] (5) Leveling Agent The leveling agent is used to reduce fingerprint adhesion to the coating film. Addition of the leveling agent can improve leveling properties, defoaming properties, water repellency, and oil repellency.

[0059] Examples of the leveling agent include a silicone-based leveling agent and a fluorine-modified acrylic-based leveling agent. From the viewpoint of achieving excellent water repellency and oil repellency, a fluorine-modified acrylic-based leveling agent such as a fluorine-modified acrylic oligomer may be used as the leveling agent.

[0060] [Method of Manufacturing Coating Agent] Next, a method of manufacturing the coating agent according to this embodiment will be described with reference to a flowchart shown in FIG.

[0061] 3, in the production of the coating agent according to this embodiment, the silver-based antibacterial glass agent is first subjected to a heat treatment (step S11). There are no particular limitations on the method for heat treating the silver-based antibacterial glass agent. The heat treatment is carried out, for example, by placing the silver-based antibacterial glass agent in a heat-resistant container in a heating device such as a hot air drying oven that has been preheated to a heat treatment temperature.

[0062] Furthermore, in step S11, when the heating temperature in the heat treatment is A [°C] and the heating time is B [minutes], A × B is 8400 or more. This can improve the antibacterial and antiviral performance of the antibacterial agent. This is presumably because the heat treatment removes moisture from the surface of the silver-based glass particles, thereby increasing the activity of the silver-based glass particles. From the viewpoint of further improving the antibacterial and antiviral performance, A × B may be 9000 or more, or may be 9600 or more. Furthermore, A × B is, for example, 20000 or less. A × B may also be 12000 or less.

[0063] The heating temperature in the heat treatment is, for example, 60°C or higher. The heating temperature in the heat treatment may be 80°C or higher. Furthermore, from the viewpoint of shortening the heating time in the heat treatment and further improving the antibacterial and antiviral performance, the heating temperature in the heat treatment may be 140°C or higher, or 160°C or higher. Furthermore, the heating temperature in the heat treatment is, for example, 400°C or lower. The heating temperature in the heat treatment may be 300°C or lower, or 200°C or lower.

[0064] The heating time in the heat treatment is, for example, 20 minutes or more. The heating time in the heat treatment may be 30 minutes or more, or 50 minutes or more. The heating time in the heat treatment is, for example, 150 minutes or less. The heating time in the heat treatment may be 120 minutes or less, or 90 minutes or less.

[0065] Next, the curable resin component, the solvent, and the silver-based glass antibacterial agent that has been heat-treated in step S11 are mixed (step S12). At this time, other components other than the silver-based glass antibacterial agent, the curable resin component, and the solvent, such as a thixotropic agent and a leveling agent, may be further mixed. That is, in step S12, the silver-based glass antibacterial agent that has been heat-treated in step S11 is mixed with the components of the coating agent other than the silver-based glass antibacterial agent. In this way, all the components contained in the coating agent are mixed, and the coating agent is obtained.

[0066] In the mixing step S12, for example, first, at least a portion of the solvent and the resin raw material are placed in a container and the contents of the container are stirred. Then, a photopolymerization initiator, a silver-based glass antibacterial agent, and optionally other components such as a thixotropic agent and a leveling agent are placed in the container and the contents of the container are further stirred. If necessary, additives are dispersed in the solvent using a bead mill or the like, and then, if necessary, solvent is added so that the solid content of the coating agent reaches a predetermined concentration. The solid content concentration in the coating agent is, for example, 10% by mass or more and 50% by mass or less. The order and method of mixing are not particularly limited as long as the components of the coating agent are uniformly mixed.

[0067] [Method for Producing a Coating Film] Next, a method for forming a coating film using the coating agent according to the present embodiment will be described. Fig. 4 is a flowchart showing an example of a method for producing a coating film according to the present embodiment.

[0068] As shown in Figure 4, in the production of a coating film according to this embodiment, first, the coating agent produced by the above-described production method is applied to the surface of a substrate (step S21). The substrate is, for example, a display, a glass plate, a resin plate, or a resin film, but is not particularly limited. The surface of the substrate may be surface-treated. The surface treatment is, for example, corona discharge treatment, but the surface treatment method may be appropriately determined depending on the material of the substrate and is not particularly limited. Furthermore, the coating method is not particularly limited. Examples of coating methods include roll coating, bar coating, gravure coating, spraying, airless spraying, and air spraying.

[0069] Before application, the coating agent may be further diluted with a solvent and then applied. The solvent used for dilution may be, for example, the same solvent as that contained in the coating agent (if multiple types of solvents are used in the coating agent, at least one of the solvents contained in the coating agent). The dilution ratio is appropriately set depending on the application method and the solids concentration of the coating agent before dilution, and is, for example, 1.1 times or more and 2 times or less.

[0070] The thickness of the coating agent applied in step S21 is set to, for example, a value obtained by dividing the final coating thickness by the solid content concentration of the coating agent so that the final coating thickness becomes the desired thickness.

[0071] Next, the coated material applied in step S21 is dried (step S22). This removes the solvent from the coating agent. The drying temperature is, for example, 60°C or higher and 100°C or lower. The drying time is 0.5 minutes or higher and 5 minutes or lower. After drying, the material is cooled (allowed to cool) at room temperature for a predetermined time, for example. The cooling time is, for example, 1 minute or higher and 10 minutes or lower. The cooling time here is the time from the end of drying to the start of curing, which will be described below.

[0072] Next, the curable resin component is cured (step S23). This cures the curable resin component, resulting in a coating film that coats the surface of the substrate. If the curable resin component is photocurable, the curable resin component is cured, for example, by irradiating the coated object with ultraviolet light.

[0073] Examples of light sources for ultraviolet irradiation include high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, etc. The conditions for ultraviolet irradiation are appropriately determined depending on the components of the coating agent, the film thickness, etc., but for example, the conditions for ultraviolet irradiation are set so that the integrated illuminance on the coated object is 100 mJ / cm ２ More than 20000mJ / cm ２ It is set to be as follows:

[0074] The coating agent and coating film according to the present disclosure will be specifically described below in examples, but the present disclosure is not limited to the following examples.

[0075] [Preparation of Coating Agent] Coating agents in the examples and comparative examples were prepared by the following method.

[0076] (1) Example 1 First, a silver-based glass antibacterial agent (Million Guard PG721F, manufactured by Koa Glass Co., Ltd.) with a particle size of 1 μm placed in a metal container was heat-treated in a hot air drying furnace under the conditions of a heating temperature of 180° C. and a heating time of 60 minutes. That is, when the heating temperature in the heat treatment is A [° C.] and the heating time is B [minutes], the silver-based glass antibacterial agent was heat-treated under the conditions of A = 180, B = 60, and A × B = 10,800.

[0077] Next, a solvent containing methyl ethyl ketone as a main component was placed in a container, and the resin raw materials were then added and stirred. The resin raw materials used were dipentaerythritol hexaacrylate, an unsaturated group-containing acrylic copolymer, and methyl methacrylate. The mass ratio of dipentaerythritol hexaacrylate, the unsaturated group-containing acrylic copolymer, and the methyl methacrylate was 76.53:22.95:0.53. The unsaturated group-containing acrylic copolymer used was a copolymer of benzyl methacrylate and methacrylic acid in a mass ratio of 80:20 (acid value 132 mg KOH / g, weight average molecular weight 19,000).

[0078] Next, the photopolymerization initiator, silver-based glass antibacterial agent, thixotropic agent, and leveling agent were further placed in a container and stirred, and the additives were dispersed in the solvent using a bead mill. 1-hydroxycyclohexyl phenyl ketone and 2-methyl-4'-methylthio-2-morpholinopropiophenone were used as the photopolymerization initiator. The ratios of 1-hydroxycyclohexyl phenyl ketone and 2-methyl-4'-methylthio-2-morpholinopropiophenone to the respective resin raw materials were each 1.17% by mass. Cellulose acetopropionate and fluorine-modified acrylic oligomer were used as the thixotropic agent and leveling agent, respectively.

[0079] The contents of the curable resin component, silver-based glass antibacterial agent, thixotropic agent, and leveling agent in the solid content of the coating agent were 84.3 mass %, 4.10 mass %, 11.43 mass %, and 0.17 mass %, respectively.

[0080] Methyl ethyl ketone was further added to the container so that the solid content concentration in the coating agent became 30% by mass, thereby obtaining the coating agent of Example 1.

[0081] (2) Examples 2 to 7 Coating agents in Examples 2 to 7 were prepared in the same manner as in Example 1, except that the heat treatment conditions for the silver-based glass antibacterial agent were changed to the conditions shown in Table 1.

[0082] (3) Examples 8 and 9 Coating agents in Examples 8 and 9 were prepared in the same manner as in Example 1, except that the particle diameter of the silver-based glass antibacterial agent was changed to the particle diameter shown in Table 1.

[0083] (4) Examples 10 to 12 Coating agents in Examples 10 to 12 were prepared in the same manner as in Example 1, except that the content of the silver-based glass antibacterial agent in the solid content of the coating agent was changed to the content shown in Table 1, and the contents of the other components were adjusted according to the change in the content of the silver-based glass antibacterial agent.

[0084] (5) Comparative Example 1 A coating agent in Comparative Example 1 was prepared in the same manner as in Example 1, except that the silver-based glass antibacterial agent was not subjected to heat treatment.

[0085] (6) Comparative Examples 2 to 4 Coating agents in Comparative Examples 2 to 4 were prepared in the same manner as in Example 1, except that the heat treatment conditions for the silver-based glass antibacterial agent were changed to the conditions shown in Table 1.

[0086] [Preparation of Coating Film] A coating film was prepared using the coating agent obtained in each of the Examples and Comparative Examples. The preparation of the coating film using the coating agent was carried out under the same conditions for each of the Examples and Comparative Examples.

[0087] First, a coating agent was applied to the surface of a polyethylene terephthalate film (Lumirror (registered trademark) T60, manufactured by Toray Industries, Inc.) prepared as a substrate using a bar coater method to a film thickness of 40 μm. The coating agent was diluted 1.2 times with methyl ethyl ketone to a solids concentration of 25 mass%. Furthermore, before applying the coating agent, the surface of the substrate was subjected to a corona discharge treatment.

[0088] Next, the coated product was dried at 100°C for 1 minute and cooled at room temperature for 3 minutes. After cooling, the applied radiation dose was 300 mJ / cm ２ The curable resin component was cured by ultraviolet irradiation under the conditions of 1. The thickness of the resulting coating film was 10 μm.

[0089] [Evaluation of antibacterial and antiviral properties of coating film] The antibacterial and antiviral properties of the coating film in each of the examples and comparative examples obtained above were evaluated.

[0090] (1) Evaluation Method To evaluate the antibacterial and antiviral performance of the coating film, a bacteriophage antiviral test was conducted in a dark place in accordance with JIS R 1706:2020, and the antiviral activity value, which is expressed as the difference in the logarithm of the infectivity titer before and after the test, was calculated. However, according to JIS R 1706:2020, the number of bacteriophage colonies to be inoculated was set to 6 x 10 １０ ~10 １１ The test was carried out in a volume of cfu / ml.

[0091] (2) Evaluation Results The evaluation results are shown in Table 1. Fig. 5 shows the relationship between the antiviral activity value of the coating film and A×B in Examples 1 to 7 and Comparative Examples 2 to 4, which were subjected to different heat treatment conditions for the heat treatment of the silver-based glass antibacterial agent. In Fig. 5, evaluation results obtained by heat treatment for the same heating time are plotted with the same type of marker. Also in Fig. 5, the antiviral activity value of the coating film in Comparative Example 1, in which the silver-based glass antibacterial agent was not subjected to heat treatment, is shown by a dashed dotted line.

[0092]

[0093] 5 , when A×B is 8400 or more, the antiviral activity value increases compared to when the silver-based glass antibacterial agent is not subjected to heat treatment, and exceeds 4. In other words, by subjecting the silver-based glass antibacterial agent to heat treatment under heat treatment conditions that result in A×B of 8400 or more, the antibacterial and antiviral performance is improved.

[0094] Furthermore, as shown in FIG. 5 , it is believed that when A×B is 9000 or more, the antiviral activity value exceeds 5, and by subjecting the silver-based glass antibacterial agent to heat treatment under heat treatment conditions that result in A×B being 9000 or more, the antibacterial and antiviral performance can be significantly improved.

[0095] Furthermore, as can be seen from a comparison of Examples 2 and 4 to 7, when the value of A×B was the same, no significant difference in the antiviral activity value was observed even if the heating temperature and heating time in the heat treatment were different.

[0096] Furthermore, as shown in Table 1, a coating film with high antibacterial and antiviral performance was achieved even when the particle size of the silver-based glass antibacterial agent was larger than that of Examples 1 to 7, as in Examples 8 and 9. Furthermore, as can be seen from Examples 1 and 10 to 12, a coating film with high antibacterial and antiviral performance was achieved not only when the content of the silver-based glass antibacterial agent in the solid content was increased from 4.10 mass%, but also when the content of the silver-based glass antibacterial agent in the solid content was reduced from 4.10 mass% to 2.47 mass%.

[0097] [Evaluation of Optical Properties of Coating Film] The optical properties of the coating films obtained above were evaluated in Examples 1 and 8 to 12. As the optical properties, light transmittance was measured and glare was evaluated.

[0098] (1) Method for measuring light transmittance The light transmittance of the coating film was measured using a haze meter manufactured by BYK-Chemie. The measured light transmittance is the total light transmittance of visible light. If the light transmittance is 85% or more, it can be said that the transparency of the coating film is high.

[0099] (2) Evaluation method for glare A smartphone (Samsung Electronics, Galaxy (registered trademark) A30) with an organic EL display with a pixel density of 403 PPi was prepared as a display. Isopropyl alcohol was then dropped onto the display, a coating film was placed on the display, and the coating film was pressed down from above to remove air from between the coating film and the display. The degree of glare was then visually evaluated according to the following criteria. A rating of "2" or higher was considered to be a good level that was unlikely to be noticeable in actual use.

[0100] 3: Almost no glare was perceived 2: A little glare was perceived (the brightness of the glare area was low) 1: Clear glare was perceived (the brightness of the glare area was high)

[0101] (3) Evaluation Results Table 2 shows the evaluation results of the optical properties.

[0102]

[0103] As shown in Table 2, it was confirmed that the optical properties of the coating films in Examples 1 and 8 to 12 were all good. Furthermore, the optical properties were particularly good in Examples 1 and 8, in which the particle size of the silver-based glass antibacterial agent was 3 μm or less, and in Examples 1, 10, and 11, in which the content of the silver-based glass antibacterial agent in the solid content of the coating agent was 5.73 mass% or less.

[0104] (Others) The coating agent and coating film according to the present disclosure have been described above based on embodiments and examples, but the present disclosure is not limited to these embodiments and examples. As long as they do not deviate from the gist of the present disclosure, various modifications that a person skilled in the art would conceive of to the embodiments and examples, as well as other forms constructed by combining some of the components of the embodiments and examples, are also included in the scope of the present disclosure.

[0105] The coating agent and coating film according to the present disclosure can be used to coat various objects.

Claims

1. Heat treatment of silver-based glass antibacterial agents, This includes mixing a curable resin component, a solvent, and the heat-treated silver-based glass antibacterial agent, If the heating temperature in the aforementioned heat treatment is A [°C] and the heating time is B [minutes], then A × B is 8400 or more. A method for manufacturing a coating agent.

2. The heating temperature is 160°C or higher. A method for producing a coating agent according to claim 1.

3. A × B is 9000 or more. A method for producing a coating agent according to claim 1 or 2.

4. The curable resin component is photocurable. A method for producing a coating agent according to claim 1 or 2.

5. The content of the silver-based glass antibacterial agent in the solid content of the coating agent is 2% by mass or more. A method for producing a coating agent according to claim 1 or 2.

6. The aforementioned content is 6% by mass or less. A method for producing a coating agent according to claim 5.

7. The particle size of the silver-based glass antibacterial agent is 3 μm or less. A method for producing a coating agent according to claim 1 or 2.

8. Applying a coating agent manufactured by the method for manufacturing a coating agent described in claim 1 or 2 to the surface of a substrate, The process includes curing the aforementioned curable resin component, A method for manufacturing a coating film.