Paint and articles coated with said paint

Abstract

To provide a coating that is suitable for various uses including: metal products such as automobiles, railway vehicles, vessels, machines, furniture, cans, and building structures; plastic products such as automobile parts, and household appliances; wood products such as furniture, and building materials; and inorganic material products such as building materials, and glass, and has high safety and can give various substrates high antiviral properties, and an article coated with the coating.SOLUTION: A coating contains a visible photoresponsive photocatalyst (A), a resin (R), and an organic solvent (S).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a paint and an article coated with the paint. [Background technology]

[0002] Traditionally, paints have been used to protect the surfaces of various articles and to improve their appearance and functionality. In recent years, however, hygienic functions, such as antibacterial and antiviral properties, have also been desired. In particular, there is a demand for paints that can produce coating films with antiviral properties (virus inactivation properties) as a measure against infections such as new strains of influenza, SARS (Severe Acute Respiratory Syndrome), and norovirus.

[0003] Paints containing quaternary ammonium salts are known as paints capable of imparting antibacterial and antiviral properties to coating films (see, for example, Patent Document 1). However, these paints have low safety, and there has been a demand for materials that do not contain quaternary ammonium salts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6603495 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a coating material which is highly safe and capable of imparting excellent antiviral properties to various substrates, and an article coated with the coating material. [Means for solving the problem]

[0006] Means for Solving the Problems The inventors conducted intensive research to solve the above problems, and as a result, discovered that the above problems could be solved by using a paint containing a specific photocatalyst, resin, and organic solvent, and thus completed the invention.

[0007] That is, the present invention relates to a coating material comprising a visible light responsive photocatalyst (A), a resin (R), and an organic solvent (S). Effect of the Invention

[0008] The coating material of the present invention can form a coating film with excellent antiviral properties, and therefore can be suitably used for metal products such as automobiles, railway cars, ships, machinery, furniture, cans, and building structures; plastic products such as automobile parts and home appliances; wood products such as furniture and building materials; and inorganic material products such as building materials and glass. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The coating material of the present invention contains a visible light responsive photocatalyst (A), a resin (R), and an organic solvent (S).

[0010] The visible light responsive photocatalyst (A) may be, for example, a composition containing titanium oxide (a). In terms of obtaining even more excellent antiviral properties, a composition in which a metal compound is supported on titanium oxide (a) is preferred.

[0011] As the titanium oxide (a), for example, rutile type titanium oxide (a1), anatase type titanium oxide, brookite type titanium oxide, etc. can be used. These titanium oxides may be used alone or in combination of two or more. Among these, it is preferable to include rutile type titanium oxide (a1) because it has excellent photocatalytic activity in the visible light region.

[0012] The content of the rutile-type titanium oxide (a1) (rutilated rate) is preferably 15 mol % or more, more preferably 50 mol % or more, and even more preferably 90 mol % or more, in order to obtain even more excellent antiviral properties in bright places and dark places, organic compound decomposition properties in bright places, and visible light responsiveness.

[0013] Generally, the liquid phase method and the gas phase method are known as the manufacturing method of the titanium oxide (a). The liquid phase method is a method in which titanium oxide is obtained by hydrolyzing or neutralizing titanyl sulfate obtained from a liquid in which raw ore such as ilmenite ore is dissolved. The gas phase method is a method in which titanium oxide is obtained by a gas phase reaction between titanium tetrachloride obtained by chlorinating raw ore such as rutile ore and oxygen. In addition, a method for distinguishing between titanium oxides manufactured by both methods includes analyzing the impurities. Titanium oxide manufactured by the liquid phase method contains zirconium, niobium, etc. derived from impurities in ilmenite ore in the product. In contrast, the gas phase method has a process of purifying titanium tetrachloride and removing impurities, so that these impurities are hardly contained in titanium oxide.

[0014] Although titanium oxide produced by the gas phase method has the advantage of being able to produce uniform particle diameters, it is thought that secondary aggregates are difficult to produce, and therefore the apparent specific surface area is high, which increases the viscosity of the mixed liquid during the reaction process. In contrast, titanium oxide (a) produced by the liquid phase method is thought to produce gentle secondary aggregates in the firing process, and has low coagulation power compared to the specific surface area (BET value) caused by the primary particles, making it possible to suppress the viscosity of the mixed liquid. For these reasons, titanium oxide (a) produced by the liquid phase method is preferable because it can further improve the productivity of the paint.

[0015] The BET specific surface area of ​​the titanium oxide (a) is preferably 1 to 200 m, since it provides even more excellent antiviral properties and visible light responsiveness. 2 / g is preferable, and 3 to 100m 2 / g is more preferable, and 4 to 70m 2 / g is more preferable, and 8 to 50m 2 The range of 7.5 to 9.5 m / g is more preferable since the productivity of the antiviral agent can be further increased. 2 The BET specific surface area of ​​the rutile-type titanium oxide (a1) is preferably in the range of 1 / g. The method for measuring the BET specific surface area of ​​the rutile-type titanium oxide (a1) will be described in the Examples below.

[0016] The primary particle diameter of the titanium oxide (a) is preferably in the range of 0.01 to 0.5 μm, more preferably in the range of 0.06 to 0.35 μm, in order to obtain even better antiviral properties and visible light responsiveness. The primary particle diameter of the titanium oxide (a) is measured by a method in which a transmission electron microscope (TEM) is used to directly measure the size of the primary particles from an electron microscope photograph. Specifically, the minor axis diameter and major axis diameter of each primary particle of titanium oxide are measured, and the average is taken as the particle diameter of the primary particles. Next, the volume (weight) of each particle is calculated for 100 or more titanium oxide particles by approximating it to a cube of the calculated particle diameter, and the volume average particle diameter is taken as the average primary particle diameter.

[0017] In addition, as the visible light responsive photocatalyst, it is preferable to use a metal compound supported on titanium oxide (a), since this further improves photocatalytic activity in the visible light region and is likely to exhibit appropriate activity capable of decomposing dirt components under practical indoor light.

[0018] As the metal compound, for example, a copper compound, an iron compound, a tungsten compound, etc. can be used. Among these, a copper compound is preferred, and a divalent copper compound is more preferred, in that it provides even more excellent antibacterial and antiviral properties. A known method can be used to support the metal compound on the titanium oxide (a).

[0019] Next, the most preferred embodiment, that is, the method for supporting a divalent copper compound on titanium oxide (a), will be described.

[0020] An example of a method for supporting a divalent copper compound on the titanium oxide (a) is a method having a mixing step (i) of titanium oxide (a) including rutile-type titanium oxide (a1), a divalent copper compound raw material (b), water (c), and an alkaline substance (d).

[0021] The concentration of the titanium oxide (a) in the mixing step (i) is preferably in the range of 3 to 40% by mass. In the present invention, when titanium oxide (a) produced by a liquid phase method is used, the mixing step can be carried out with good handling even if the concentration of the titanium oxide (a) is increased, and specifically, the mixing step can be carried out well even if the concentration of the titanium oxide (a) is in the range of more than 25% by mass to 40% by mass or less.

[0022] As the divalent copper compound raw material (b), for example, an inorganic divalent copper compound, an organic divalent copper compound, etc. can be used.

[0023] Examples of the divalent copper inorganic compound that can be used include inorganic acid salts of divalent copper such as copper sulfate, copper nitrate, copper iodate, copper perchlorate, copper oxalate, copper tetraborate, ammonium copper sulfate, copper amidosulfate, ammonium copper chloride, copper pyrophosphate, and copper carbonate; divalent copper halides such as copper chloride, copper fluoride, and copper bromide; copper oxide, copper sulfide, azurite, malachite, and copper azide. These compounds may be used alone or in combination of two or more.

[0024] Examples of the divalent copper organic compound include copper formate, copper acetate, copper propionate, copper butyrate, copper valerate, copper caproate, copper enanthate, copper caprylate, copper pelargonate, copper caprate, copper myristic acid, copper palmitate, copper margarate, copper stearate, copper oleate, copper lactate, copper malate, copper citrate, copper benzoate, copper phthalate, copper isophthalate, copper terephthalate, copper salicylate, copper mellitic acid, copper oxalate, copper malonate, copper succinate, copper glutarate, copper adipate, copper fumarate, and glycol. Examples of compounds that can be used include copper glycerate, copper gluconate, copper tartrate, copper acetylacetone, copper ethylacetoacetate, copper isovalerate, copper β-resorcylate, copper diacetoacetate, copper formylsuccinate, copper salicylamine, copper bis(2-ethylhexanoate), copper sebacate, copper naphthenate, copper oxine, copper acetylacetone, copper ethylacetoacetate, copper trifluoromethanesulfonate, copper phthalocyanine, copper ethoxide, copper isopropoxide, copper methoxide, and copper dimethyldithiocarbamate. These compounds may be used alone or in combination of two or more.

[0025] As the divalent copper compound raw material (b), among those mentioned above, it is preferable to use one represented by the following general formula (1). CuX 2 (1) (In formula (1), X is a halogen atom, CH 3 COO, NO 3 , or (SO 4 ) 1 / 2 (Indicates

[0026] X in the above formula (1) is more preferably a halogen atom, and further preferably a chlorine atom.

[0027] The amount of the divalent copper compound raw material (b) used in the mixing step (i) is preferably in the range of 0.01 to 20 parts by mass, more preferably in the range of 0.1 to 15 parts by mass, and even more preferably in the range of 0.3 to 10 parts by mass, relative to 100 parts by mass of the titanium oxide (a).

[0028] The water (c) is a solvent in the mixing step (i), and is preferably water alone, but may contain other solvents as necessary. Examples of the other solvents that can be used include alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; dimethylformamide, tetrahydrofuran, and the like. These solvents may be used alone or in combination of two or more.

[0029] As the alkaline substance (d), for example, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, triethylamine, trimethylamine, ammonia, a basic surfactant, etc. can be used, and it is preferable to use sodium hydroxide.

[0030] The alkaline substance (d) is preferably added as a solution in order to facilitate control of the reaction. The concentration of the alkaline solution to be added is preferably in the range of 0.1 to 5 mol / L, more preferably in the range of 0.3 to 4 mol / L, and even more preferably in the range of 0.5 to 3 mol / L.

[0031] In the mixing step (i), the titanium oxide (a), the divalent copper compound raw material (b), water (c), and the alkaline substance (d) may be mixed, for example, by first mixing the titanium oxide (a) with the water (c) and stirring as necessary, then mixing and stirring the divalent copper compound raw material (b), and then adding and stirring the alkaline substance (d). By this mixing step (i), the divalent copper compound derived from the divalent copper compound raw material (b) is supported on the titanium oxide (a).

[0032] The total stirring time in the mixing step (i) is, for example, 5 to 120 minutes, and preferably 10 to 60 minutes. The temperature during the mixing step (i) is, for example, in the range of room temperature to 70°C.

[0033] In order to favorably support the divalent copper compound on the titanium oxide (a), the titanium oxide (a), the divalent copper compound raw material (b), and water (c) are mixed and stirred, and then the alkaline substance (d) is mixed and stirred. The pH of the mixture thus obtained is preferably in the range of 8 to 11, and more preferably in the range of 9.0 to 10.5.

[0034] After the mixing step (i) is completed, the mixture can be separated as a solid content. Examples of the method for the separation include filtration, sedimentation, centrifugation, evaporation and drying, and filtration is preferred. The separated solid content may then be washed with water, crushed, classified, etc., as necessary.

[0035] After obtaining the solid content, it is preferable to heat treat the solid content in order to more firmly bind the divalent copper compound derived from the divalent copper compound raw material (b) supported on the titanium oxide (a). The heat treatment temperature is preferably in the range of 150 to 600° C., more preferably in the range of 250 to 450° C. The heat treatment time is preferably 1 to 10 hours, more preferably 2 to 5 hours.

[0036] By the above method, a titanium oxide composition containing titanium oxide in which a divalent copper compound is supported on titanium oxide (a) can be obtained. The amount of the divalent copper compound supported on the titanium oxide (a) is preferably in the range of 0.01 to 20 parts by mass per 100 parts by mass of titanium oxide (a) from the viewpoint of photocatalytic activity including antiviral activity. The amount of the divalent copper compound supported can be adjusted by the amount of the divalent copper compound raw material (b) used in the mixing step (i).

[0037] The resin (R) is not particularly limited as long as it is one that is generally used as a resin for coatings, and examples thereof include acrylic resins, polyester resins, epoxy ester resins, alkyd resins, urethane resins, and epoxy resins.

[0038] Furthermore, by introducing a crosslinkable functional group into the resin (R), the coating material of the present invention can be used as a two-component coating material.

[0039] As the organic solvent (S), known organic solvents used in coating applications can be used, for example, aromatic hydrocarbon compounds such as toluene, xylene, ethylbenzene, etc.; alicyclic hydrocarbon compounds such as cyclohexane, methylcyclohexane, ethylcyclohexane, etc.; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; ester compounds such as ethyl acetate, n-butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate, etc.; alcohol compounds such as n-butanol, isopropyl alcohol, cyclohexanol, etc.; glycol compounds such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, etc.; aliphatic hydrocarbon compounds such as heptane, hexane, octane, mineral turpentine, etc. These organic solvents may be used alone or in combination of two or more.

[0040] The content of the visible light responsive photocatalyst (A) in the coating material of the present invention is preferably 1 to 20% by mass, since this provides better antiviral properties and storage stability.

[0041] The content of the resin (R) in the coating material of the present invention is preferably 25 to 50% by mass, since this provides better antiviral properties and storage stability.

[0042] The content of the organic solvent (S) in the coating material of the present invention is preferably 40 to 70 mass % since this provides better antiviral properties and storage stability.

[0043] The content of the visible light responsive photocatalyst (A) in the solid content of the coating material of the present invention is preferably 5 to 20 mass%, more preferably 5 to 15 mass%, since this provides a better balance between antiviral properties and other coating film properties.

[0044] The coating material of the present invention contains the visible light responsive photocatalyst (A), the resin (R), and the organic solvent (S), and it is preferable that the visible light responsive photocatalyst (A) and the resin (R) are dissolved or dispersed in the organic solvent (S).

[0045] In addition, the coating material of the present invention may contain various additives, such as inorganic pigments, organic pigments, extender pigments, waxes, surfactants, stabilizers, flow adjusters, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, plasticizers, antistatic agents, defoamers, viscosity adjusters, light resistance stabilizers, weather resistance stabilizers, heat resistance stabilizers, pigment dispersants, thermosetting resins and thermoplastic resins, as required.

[0046] The coating material of the present invention can be prepared, for example, by adding the visible light responsive photocatalyst (A) and a pigment to a resin composition in which the resin (R) is dissolved in the organic solvent (S), and using a mixer such as a sand mill or a disperser. If necessary, a curing agent can be further added to prepare a two-liquid coating material.

[0047] Examples of methods for applying the coating material of the present invention include methods using a gravure coater, roll coater, comma coater, knife coater, air knife coater, curtain coater, kiss coater, shower coater, wheeler coater, spin coater, dipping, screen printing, spraying, applicator, bar coater, brush, etc.

[0048] The coating material of the present invention can provide a cured coating film having excellent antiviral properties to the surfaces of various articles.

[0049] The coating material of the present invention may be applied directly to the article to be coated, or a primer coating material suitable for the article to be coated may be applied first, and then the coating material of the present invention may be applied. In addition, after applying the coating material of the present invention, a top coat may be applied over it.

[0050] Examples of materials for the article to be coated include various metals such as steel plate, iron, copper, zinc, aluminum, magnesium, etc., and alloys of these metals; plastic substrates such as polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), PC-ABS polymer alloy, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyamide (PA), polypropylene (PP), fiber-reinforced plastic (FRP) containing fillers such as glass fiber and carbon fiber; and glass.

[0051] Examples of articles having a coating film of the paint of the present invention include metal products such as automobiles, railway cars, ships, machinery, furniture, cans, and building structures; plastic products such as automobile parts and home appliances; wood products such as furniture and building materials; and inorganic material products such as building materials and glass. EXAMPLES

[0052] The present invention will now be described in more detail with reference to specific examples.

[0053] (Preparation Example 1: Preparation of visible light responsive photocatalyst (A-1)) (1) Titanium dioxide a) Crystalline rutile titanium dioxide b) Manufacturing method: Liquid phase method (sulfuric acid method) c) Physical properties ·BET specific surface area: 9.0m 2 / g Rutile rate: 95.4% ·Primary particle size: 0.18μm

[0054] (2) Manufacturing process a) Mixing process (reaction process) 600 parts by mass of the titanium oxide, 8 parts by mass of copper(II) chloride dihydrate, and 900 parts by mass of water were mixed in a stainless steel container. The mixture was then stirred with a stirrer ("Robomix" manufactured by Tokushu Kika Kogyo Co., Ltd.), and a 1 mol / L aqueous solution of sodium hydroxide was added dropwise until the pH of the mixture reached 10. b) Dehydration process The mixture was filtered under reduced pressure using qualitative filter paper (5C) to separate the solid matter from the mixture, and then washed with ion-exchanged water. The washed solid matter was then dried at 120°C for 12 hours to remove moisture. After drying, a powdered titanium oxide composition was obtained using a mill (Iwatani Sangyo Co., Ltd.'s "Miller"). c) Heat treatment process The mixture was heat-treated at 450°C for 3 hours in the presence of oxygen using a precision incubator (DH650 manufactured by Yamato Scientific Co., Ltd.) to obtain a visible light responsive photocatalyst (A-1) containing titanium oxide carrying a divalent copper compound.

[0055] (Example 1: Production of paint (1)) To 100 parts by mass of a solvent-based acrylic resin (DIC Corporation's "ACRYDIC A-801-P"), 11.2 parts by mass of the above-obtained visible light responsive photocatalyst (A-1), 35.2 parts by mass of a titanium oxide pigment (Chemours Corporation's "Ti-Pure R-706"), and 19.9 parts by mass of butyl acetate were added and kneaded for 30 minutes with a sand mill to obtain a pigment dispersion. 28.4 parts by mass of a polyisocyanate resin (DIC Corporation's "Burnoc DN-980") was added as a curing agent to the obtained pigment dispersion, and the mixture was stirred with a disperser for 5 minutes to obtain paint (1).

[0056] (Examples 2 to 5: Production of paints (2) to (5)) Coating materials (2) to (5) were obtained in the same manner as in Example 1, except that the raw materials used were changed to those in Table 1.

[0057] (Comparative Examples 1 to 5: Production of Paints (R1) to (R5)) Paints (R1) to (R5) were obtained in the same manner as in Example 1, except that the raw materials used were changed to those in Table 1.

[0058] [Preparation of coating film for evaluation] Each of the paints obtained above was sprayed onto a chromate-treated aluminum plate to a film thickness of 15 μm, and then dried at 23° C. for 7 days to obtain a test plate having a coating film for evaluation.

[0059] [Antiviral evaluation] An anti-phage virus test (see JIS R1756:2020) was carried out on the test plates on which the coating films for evaluation obtained in the examples and comparative examples were formed.

[0060] 1) The light irradiation conditions were white fluorescent light with an N113 filter to cut out ultraviolet rays, and the illuminance was 500 lux. 2) 100 μL of Qβ phage solution with a known concentration was dropped onto the 5 cm×5 cm test plate obtained in the Examples and Comparative Examples, and then a 4 cm×4 cm adhesive film was placed over the plate to prepare a sample for evaluation. 3) The sample exposed to light for 8 hours was collected in SCDLP liquid, appropriately diluted, infected with E. coli, spread on an agar medium, and evaluated by counting the number of colonies after cultivation. Antiviral activity was evaluated based on the degree of inactivation of Qβ phage according to the following criteria. ◎: Inactivation level is -3 or less ○: Inactivation level is greater than -3 and less than -2 ×: Inactivation degree is greater than -2

[0061] The compositions and evaluation results of the paints (1) to (5) and (R1) to (R5) obtained above are shown in Tables 1 and 2.

[0062] [Table 1]

[0063] [Table 2]

[0064] The raw materials in the table are as follows: "ACRYDIC A-801-P": Solvent-based acrylic resin manufactured by DIC Corporation (hydroxyl value: 100 mg KOH / g, resin content: 49% by mass, organic solvent: toluene, n-butyl acetate) "Burnoc 16-416": Solvent-based urethane resin manufactured by DIC Corporation (resin content: 30% by weight, organic solvent: methyl ethyl ketone, isopropyl alcohol) "Burnoc EQD-1097": DIC Corporation, solvent-based polyester resin (hydroxyl value: 290 mg KOH / g, resin content: 77% by mass, organic solvent: ethylbenzene, xylene) "Alkidia ES-4505-60-X": Solvent-based polyester resin manufactured by DIC Corporation (resin content: 60% by mass, organic solvent: ethylbenzene, xylene) "Epiclon 1050-70X": Solvent-based epoxy resin manufactured by DIC Corporation (resin content: 70% by mass, organic solvent: ethylbenzene, xylene) "Burnoc DN-980": DIC Corporation, polyisocyanate resin (isocyanate group content (NCO%): 15.5% by mass, resin content: 75% by mass, organic solvent: ethyl acetate) "Ca-OCTOATE 4%": Calcium-based metal soap manufactured by DIC Corporation "Ca-OCTOATE 6%": Cobalt-based metal soap manufactured by DIC Corporation "12% Zr-OCTOATE": Zirconium-based metal soap manufactured by DIC Corporation

[0065] It was confirmed that the coating films obtained from Examples 1 to 5, which are the paints of the present invention, have excellent antiviral properties.

[0066] On the other hand, Comparative Examples 1 to 5 are examples that do not contain the visible light responsive photocatalyst (A) which is an essential component of the present invention, and it was confirmed that the resulting coating films had poor antiviral properties.

Claims

1. A method for producing a paint containing a visible light responsive photocatalyst (A), a resin (R), and an organic solvent (S), wherein the visible light responsive photocatalyst (A) is a titanium oxide (a) containing rutile-type titanium oxide (a1) having a divalent copper compound supported thereon, the titanium oxide (a) being produced by a liquid phase method, the visible light responsive photocatalyst (A) being produced by a method including a mixing step (i) of the titanium oxide (a), a divalent copper compound raw material (b), water (c), and an alkaline substance (d), and the concentration of the titanium oxide (a) in the mixing step (i) is in the range of more than 25 mass% and not more than 40 mass%.

2. 2. The method for producing a coating material according to claim 1, wherein the resin (R) contains one or more resins selected from the group consisting of acrylic resins, polyester resins, epoxy ester resins, alkyd resins, urethane resins and epoxy resins.

3. 3. The method for producing a coating material according to claim 1 or 2, which is a two-component curing type coating material.

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