Mold-resistant coating film, member, and product

Abstract

To provide a mold-resistant coating film that exhibits excellent antifungal property, high stability to heat and light, and applicability over a broad range.SOLUTION: A mold-resistant coating film of one aspect of the present disclosure includes: at least one selected from nickel powder and nickel alloy powder; and a binder resin, characterized in that the nickel ion elution rate from the coating film surface is 0.1 μg / cm2 d or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to mildew-resistant coatings, components and products. [Background technology]

[0002] In recent years, from a hygienic viewpoint, coatings intended to inhibit mold have been applied in a variety of situations, and it has become common practice to add and apply antifungal agents to coatings. Many different types of antifungal agents are known, and for example, silver-loaded zeolite, organic antifungal agents to which metal powder has been added, and coatings using cerium oxide have been proposed as antifungal agents (Patent Documents 1, 2, and 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7174198 [Patent Document 2] Japanese Patent Publication No. 2023-088351 [Patent Document 3] Japanese Patent Publication No. 2022-041991 Summary of the Invention [Problem to be solved by the invention]

[0004] The silver-supported zeolite of Patent Document 1 may discolor due to light, which may limit its range of use. The organic antifungal agent of Patent Document 2 decomposes and deteriorates due to light, heat, etc., and contains metal powder to suppress this decomposition and deterioration, making it difficult to reduce costs. The antifungal agent of Patent Document 3, which utilizes a photocatalytic reaction such as cerium oxide, cannot function in the absence of light, which may limit its range of use.

[0005] The present disclosure has been made in light of the above-mentioned circumstances, and aims to provide an anti-fungal coating film that has high anti-fungal properties, high stability against heat and light, and can be used in a wide range of applications. [Means for solving the problem]

[0006] A mildew-proofing coating according to one embodiment of the present disclosure is a mildew-proofing coating containing at least one of nickel powder and nickel alloy powder, and a binder resin, and has a nickel ion elution rate from the coating surface of 0.1 μg / cm 2 ·d or more. [Effects of the Invention]

[0007] The antifungal coating film of the present disclosure has high antifungal properties, is highly stable against heat and light, and can be used in a wide range of applications. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a graph showing the relationship between the nickel ion elution rate and the test results of mold resistance in antifungal coating films. [Figure 2] FIG. 2 is a graph showing the relationship between the elution rate parameter and the elution rate of nickel ions in an antifungal coating film. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] (1) A mildew-proofing coating according to one embodiment of the present disclosure is a mildew-proofing coating containing at least one of nickel powder and nickel alloy powder, and a binder resin, and has a nickel ion elution rate from the coating surface of 0.1 μg / cm 2 ·d or more.

[0010] The antifungal coating film (hereinafter referred to as the coating film) contains at least one of nickel powder and nickel alloy powder, and a binder resin, and therefore has high stability against heat and light. This prevents the range of use from being limited by the environment. Furthermore, the coating film elutes nickel ions from the surface into liquids such as water at the above-mentioned elution rate, thereby demonstrating high antifungal properties.

[0011] (2) In the above (1), the binder resin may contain at least one resin selected from the group consisting of a urethane resin, a cellulose resin, and a phenol resin, thereby further improving the reliability of eluting the nickel ions at the elution rate.

[0012] (3) In the above (2), the urethane-based resin may be aqueous. By using an aqueous urethane-based resin, it is possible to further improve the reliability of eluting the nickel ions at the elution rate.

[0013] (4) In any of (1) to (3) above, the elution rate parameter v expressed by the following formula 1 may be 0.1 or more. This further improves the reliability of eluting the nickel ions at the elution rate. v=-0.01885×α+0.00025×m+1.68351 (1) In the above formula 1, α is the contact angle between the coating film and water [°], m is the nickel content per unit area of the coating film [μg / cm 2 ] means.

[0014] (5) A member according to one embodiment of the present disclosure has a coating film of any one of (1) to (4) above formed on its surface.

[0015] Since the coating film is formed on the surface of the member, the member has high anti-fungal properties and can suppress limitations on the range of use depending on the environment.

[0016] (6) A product according to one embodiment of the present disclosure includes the component (5) described above.

[0017] Because the product includes the component, it has high mold resistance and can prevent its range of use from being limited by the environment.

[0018] [Details of the embodiments of the present disclosure] Hereinafter, embodiments of the present disclosure will be described in detail.

[0019] [Mold-resistant coating] The antifungal coating film according to one embodiment of the present disclosure contains at least one of nickel powder and nickel alloy powder, and a binder resin, and has a nickel ion elution rate from the coating film surface of 0.1 μg / cm 2 ·d or more.

[0020] [Nickel powder and nickel alloy powder] The coating film contains at least one of nickel powder and nickel alloy powder. That is, the coating film has powder containing nickel (Ni), a nickel alloy, or both. The nickel alloy may contain metal elements other than nickel, such as iron (Fe), cobalt (Co), or zinc (Zn). That is, the powder may consist of nickel, or may contain nickel as the main component and metal elements other than nickel. Furthermore, the powder may inevitably contain other metal elements. Note that the "main component" refers to the component with the largest content in the powder in terms of mass, e.g., a component with a content of 50 mass% or more.

[0021] Since the powder is made of nickel or an alloy containing nickel as its main component, it can release nickel ions into the adsorbed water that may be present on the surface of the powder in use. These nickel ions can come into contact with and kill bacteria, mold, etc. that may grow in the adsorbed water.

[0022] The lower limit of the nickel content relative to the total mass of the powder is preferably 70 mass %, more preferably 80 mass %, from the viewpoint of exhibiting effective antifungal properties. The upper limit of the nickel content is not particularly limited and may be, for example, 99 mass % or 100 mass %.

[0023] The powder may partially contain solid-solution elements other than metal elements. The elements contained in the powder are not particularly limited, and examples thereof include hydrogen (H), oxygen (O), and phosphorus (P). The powder preferably contains solid-solution elements of hydrogen or phosphorus, and more preferably contains solid-solution elements of hydrogen.

[0024] As a method for dissolving elemental hydrogen in the powder, for example, a method may be mentioned in which a solvent containing elemental hydrogen is mixed with raw material nickel before it is pulverized into powder, and the mixed raw material nickel is wet-pulverized. By wet-pulverizing the raw material nickel, elemental hydrogen can be added from the solvent containing elemental hydrogen into the raw material nickel at the same time as the raw material nickel is pulverized to a desired particle size.

[0025] The solvent is not particularly limited as long as it is a known solvent containing hydrogen, and examples thereof include water, ethanol, etc. When water or ethanol is used as the solvent, it is thought that the hydrogen element generated by decomposition of the solvent becomes solid-dissolved in nickel.

[0026] The lower limit of the hydrogen element content relative to the total mass of the powder obtained by wet milling is preferably 0.05% by mass, more preferably 0.07% by mass. The upper limit of the hydrogen element content is preferably 1.00% by mass, more preferably 0.80% by mass. When the powder contains hydrogen element, this hydrogen element forms a hydride that alters the proteins that make up bacteria and mold, thereby improving the antifungal effect of the coating film. Furthermore, by setting the hydrogen element content within the above range, oxidation and alteration of the powder can be suppressed, thereby improving the durability of the antifungal effect.

[0027] As a method for dissolving elemental phosphorus in the powder, for example, a method in which a predetermined amount of pure nickel and a Ni-P alloy are mixed to prepare raw nickel, and this raw nickel is pulverized by water atomization can be mentioned.

[0028] When the powder contains phosphorus, the lower limit of the phosphorus content relative to the total mass of the powder is preferably 0.15 mass%, more preferably 0.20 mass%, and even more preferably 0.25 mass%, from the viewpoint of effectively promoting the elution of nickel ions. The upper limit of the phosphorus content is preferably 15.70 mass%, more preferably 12.00 mass%, and even more preferably 10.00 mass%.

[0029] Phosphorus penetrates into the grain boundaries of the powder and promotes the elution of nickel ions. Therefore, when the powder contains phosphorus, the antifungal effect of the coating film can be improved. Furthermore, by setting the phosphorus content within the above range, the reliability of the effect of promoting the elution of nickel ions can be improved.

[0030] The lower limit of the particle size of the powder is preferably 0.1 μm, more preferably 0.2 μm, based on the 50% cumulative volume (D50 value) measured using a laser scattering particle size distribution analyzer. The upper limit of the particle size is preferably 20.0 μm, more preferably 15.0 μm. By having the particle size of the powder within the above range, the specific surface area of the powder can be made sufficient, and the antifungal effect can be improved.

[0031] The lower limit of the specific surface area of the above powder is 1 m 2 / g is preferred, and 2m 2 The upper limit of the specific surface area is 11 m / g. 2 / g is preferred, and 10m 2 / g is more preferred, and 9m 2 / g is even more preferable. With the specific surface area in the above range, a sufficient amount of nickel ions can be eluted, improving the antifungal effect. The "specific surface area" refers to the specific surface area measured by gas adsorption, and refers to the amount calculated by analyzing the amount of adsorption using N2 gas using the BET method. Specific conditions include pretreatment conditions of vacuum degassing at 200°C for 3 hours and an adsorption temperature of -196°C.

[0032] The method for adjusting the specific surface area of the powder is not particularly limited, and examples thereof include a method of controlling the processing time using a pulverizer such as a jet mill, roller mill, hammer mill, pin mill, rotary mill, vibration mill, planetary mill, attritor, or bead mill, a method of immersing in an aqueous solution of an acid or the like, and elution, etc. The pulverization using the pulverizer may be dry or wet.

[0033] [Binder resin] The coating film contains a binder resin. The binder resin may be an acrylic resin, a silicone resin, or the like, but it is preferable that the binder resin contains at least one resin selected from the group consisting of a urethane resin, a cellulose resin, and a phenol resin. The inclusion of such a resin can promote the elution of nickel ions.

[0034] The urethane resin is preferably water-based, which can improve the affinity between the coating film and water, improve the diffusion of water in the coating film, and further promote the elution of nickel ions.

[0035] The method for producing the paint that forms the coating film is not particularly limited, and examples include a method in which the powder is mixed with a solution containing the binder resin and stirred. The content of the powder relative to the total amount of the solution may be, for example, 0.1% by mass or more and 10% by mass or less. The coating film is formed by applying or coating this paint onto a desired member or the like. The solution may contain a dispersion medium, pigment, curing agent, etc. as needed, as long as the solution does not inhibit the elution of nickel ions from the coating film.

[0036] [Component] The coating film is formed on the surface of the member. That is, the coating film is formed on at least a portion of the surface of the member. The coating film may be formed on the entire surface of the member. The method for forming the coating film on the surface is not particularly limited, and examples include methods such as applying the coating with a brush or paintbrush, or spray painting, followed by drying. The member is not particularly limited, and examples include equipment components and device components. For example, members requiring mold resistance include outdoor equipment covers such as outdoor lighting covers and smart meter covers; components or housing equipment used around water such as kitchens, bathrooms, and toilets; home appliances such as refrigerators and air conditioners; ATMs (automated teller machines) installed in convenience stores; POS terminals; portable terminals such as mobile phones, smartphones, and tablets; computing devices such as personal computers; various packaging materials; wallpaper; various filters; switches; daily necessities and materials; sanitary materials; clothing; and vehicle-related parts.

[0037] [product] The product includes the component. That is, the product has the component at least in part. The product may have all of its components as the component. The product is not particularly limited, and examples thereof include equipment and devices.

[0038] [Other embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components based on the description in this specification and common general technical knowledge, and all of these should be construed as belonging to the scope of the present invention. [Example]

[0039] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0040] Nickel powder containing approximately 1% by mass of phosphorus was prepared by water atomization, and then crushed into powder with a specific surface area of 2 m2 using a bead mill.2 The powder was ground to a D50 value of 8.0 μm.

[0041] In Test Example 1, a commercially available water-based epoxy paint was used as the binder resin. The powder was mixed into a solution containing this binder resin and stirred with a medicine spoon to obtain a paint. The powder was mixed in an amount of 5 mass% based on the total mass of the solution. The obtained paint was spray-coated onto a 50 mm square polypropylene substrate and air-dried to form a mildew-resistant coating film.

[0042] In Test Example 2, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 10 mass %.

[0043] In Test Example 3, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 20 mass %.

[0044] In Test Example 4, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 2% by mass.

[0045] In Test Example 5, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 3 mass %.

[0046] In Test Example 6, an antifungal coating film was formed using the same mixing ratio and procedure as in Test Example 4.

[0047] In Test Example 7, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 0.3 mass %.

[0048] In Test Example 8, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 0.5 mass %.

[0049] In Test Example 9, an antifungal coating film was formed in the same manner as in Test Example 1, except that the mixing ratio of the powder was 1% by mass.

[0050] In Test Example 10, a mildew-resistant coating film was formed using the same procedure as in Test Example 8, except that a commercially available solvent-based urethane paint was used as the binder resin and the substrate was made of SPCC (Steel Plate Cold Commercial: cold-rolled steel plate).

[0051] In Test Example 11, an antifungal coating film was formed in the same manner as in Test Example 10, except that the mixing ratio of the powder was 1 mass %.

[0052] In Test Example 12, an antifungal coating film was formed in the same manner as in Test Example 10, except that the mixing ratio of the powder was 2% by mass.

[0053] In Test Example 13, an antifungal coating film was formed in the same manner as in Test Example 4, except that a commercially available weak solvent-based urethane paint was used as the binder resin.

[0054] The rate of nickel ion elution from the antifungal coating was measured for Test Examples 1 to 13. The antifungal coating surface of each Test Example was contacted with 2 mL of water per unit area and allowed to stand at room temperature for 7 days. The concentration of nickel ions eluted in the water for each Test Example was then measured using a Hanna Instruments HI83300 benchtop spectrophotometer. The amount of nickel ion elution calculated using the obtained value was divided by the area of the coating surface of each Test Example and the number of days of contact with water (7) to calculate the rate of nickel ion elution per unit area and number of days.

[0055] In addition, antifungal properties were tested using a mold resistance test based on JIS Z 2911:2018. First, the test mold was inoculated onto potato dextrose agar medium and cultured at 24±1°C for 10 days. After that, a 3% glucose-added inorganic base solution was used to inoculate the mold until the number of spores reached 10. 6The spore solution was prepared to a concentration of 1 / mL, which was used as the test spore solution. The test fungus used was Cladosporium sphaerospermum NBRC 6348. Each test example with the antifungal coating was placed in the center of the above-mentioned 3% glucose-supplemented inorganic salt agar medium, and the above-mentioned test spore solution was sprayed and inoculated. The test example was then cultured for 4 weeks under conditions of 24±1°C and a relative humidity of 95% or higher. After the culture, the growth of mold on the coating surface of each test example was observed with the naked eye and under a microscope.

[0056] The binder resin, powder mixture amount, and test results for each test example are shown in Table 1. The criteria for judging the mold resistance test results are shown in Table 2. In the judgments in Table 1, mold resistance test results of 0 to 2 were rated A, indicating sufficient mold resistance, and results of 3 or higher were rated B, indicating insufficient mold resistance. The relationship between the nickel elution rate in Table 1 and the mold resistance test results is shown in Figure 1.

[0057] [Table 1]

[0058] [Table 2]

[0059] Figure 1 shows a correlation between the nickel elution rate and the results of the mold resistance test. 2 Test Examples 1 to 5, which satisfied the criteria of d or higher, showed results of 0 to 2 in the mold resistance test, demonstrating excellent mold prevention effects.

[0060] In Test Example 6, in which the coating film was formed under the same conditions as Test Example 4, the result of the mildew resistance test was 3. The reason for this is thought to be that even when the paint was obtained under the same conditions, the coating film formed by spray coating described above varies in thickness, etc., and this variation can cause fluctuations in the nickel content per unit area of the coating film.

[0061] Next, a test was conducted to evaluate the relationship between the contact angle of the coating film with water and the rate of nickel elution from the coating film.

[0062] In Test Example 14, an antifungal coating film was formed in the same manner as in Test Example 4, except that a commercially available aqueous urethane paint was used as the binder resin.

[0063] In Test Example 15, an antifungal coating film was formed in the same manner as in Test Example 4, except that a commercially available weak solvent urethane paint was used as the binder resin.

[0064] In Test Example 16, a mildew-proof coating film was formed in the same manner as in Test Example 12, except that a commercially available weak solvent urethane paint different from that in Test Example 12 was used as the binder resin.

[0065] In Test Example 17, an antifungal coating film was formed in the same manner as in Test Example 16, except that a commercially available solvent-based urethane paint was used as the binder resin.

[0066] For Test Examples 14 to 17, the contact angle with water, the content of nickel element contained in the antifungal coating film, and the nickel ion elution rate were measured. The contact angle was measured using a contact angle meter after dropping water onto the antifungal coating film of each Test Example. The nickel element content was determined by peeling only the antifungal coating film of each Test Example from the substrate in the same area, dissolving this antifungal coating film in acid, and then quantifying the amount of nickel element in the solution by ICP emission spectrometry. This was done by dropping water onto the antifungal coating film of an area of 25 cm. 2 The nickel content per unit area was calculated by dividing by 0.1 μg / cm. The nickel ion elution rate was measured in the same manner as in Test Examples 1 to 13. The results are shown in Table 3. In Table 3, the results for the nickel ion elution rate were 2 A dissolution rate of 0.1 μg / cm or more is considered to be sufficient and is rated as A. 2 Those with a dissolution rate of less than d were rated B as they had an insufficient dissolution rate.

[0067] [Table 3]

[0068] Table 3 shows that the smaller the water contact angle of the antifungal coating, the greater the nickel ion elution rate. This is thought to be because antifungal coatings with a small water contact angle have a high affinity for water, which facilitates water diffusion into the coating and promotes nickel ion elution. However, it is clear that the nickel content in the antifungal coating also has a significant effect on the nickel ion elution rate, and it is thought that the balance between the hydrophilicity of the antifungal coating and the nickel content is important. Therefore, we investigated the range of hydrophilicity and nickel content required to achieve a sufficient nickel ion elution rate using the elution rate parameter v, defined as in Equation 1 below. v = -0.01885α + 0.00025m + 1.68351 ····(1) Here, α represents the contact angle of water with the antifungal coating film [°], and m [mass %] represents the nickel content in the antifungal coating film.

[0069] The calculation results of the elution rate parameter v for Test Examples 14 to 17 are shown in Table 4. The relationship between the elution rate parameter and the nickel ion elution rate is shown in Figure 2. Figure 2 confirms a high correlation between the elution rate parameter and the nickel ion elution rate, showing an approximately 1:1 correspondence. Therefore, the nickel ion elution rate of 0.1 μg / cm 3 required for sufficient antifungal properties is 2 To satisfy the condition d, it is considered preferable to form a coating film having a contact angle and nickel content that satisfies the dissolution rate parameter v of 0.1 or more.

[0070] [Table 4] [Industrial Applicability]

[0071] The antifungal coating film of the present disclosure has excellent antifungal effects and can be easily used in a variety of environments, and is therefore suitable for use in components, equipment, products, and the like that require antifungal properties.

Claims

1. A mildew-proof coating film containing at least one of nickel powder and nickel alloy powder, and a binder resin, The nickel ion elution rate from the coating surface is 0.1 μg / cm ２ -Anti-fungal coating film with a coating strength of d or higher.

2. 2. The mildew-proofing coating film according to claim 1, wherein the binder resin comprises at least one resin selected from the group consisting of urethane-based resins, cellulose-based resins, and phenol-based resins.

3. 3. The mildew-proofing coating film according to claim 2, wherein the urethane resin is water-based.

4. 2. The mildew-proofing coating film according to claim 1, wherein the dissolution rate parameter v, represented by the following formula 1, is 0.1 or more. v=-0.01885×α+0.00025×m+1.68351 (1) In the above formula 1, α is the contact angle between the coating film and water [°], m is the nickel content per unit area of the coating film [μg / cm ２ ]means.

5. A member having the antifungal coating film according to any one of claims 1 to 4 formed on its surface.

6. A product comprising the member according to claim 5.

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