Coating material, method for producing coating material, building, moving body, industrial product, and furniture / equipment

Abstract

[Problem] To provide a coating material that can reduce the amount of coating on the surface of a base material to be coated, that can be applied at a low cost, and that makes it possible to adjust the viscosity by a means which does not adversely affect the human body. [Solution] The coating material 10B is applied to the surface of the base material to be coated and forms a coating film on the surface of the base material. In the coating material 10B, microbubbles 14 and / or nanobubbles 15 are mixed therein, and the microbubbles 14 and / or nanobubbles 15 are dispersed and mixed in the coating material 10B at a predetermined concentration. The viscosity of the coating material 10B after having introduced the microbubbles 14 and / or nanobubbles 15 is lower than that of the coating material before introducing the microbubbles 14 and / or nanobubbles 15, and the viscosity of the coating material 10B after having introduced the microbubbles 14 and / or nanobubbles 15 is from 1 mPa∙s to 1000 mPa∙s.

Description

Paints and paint manufacturing methods, as well as buildings, vehicles, industrial products, furniture and equipment

[0001] The present invention relates to a paint to be applied to the surface of a substrate to be coated and a method for producing the paint, as well as to buildings, mobile objects, industrial products, furniture and fixtures.

[0002] a fluorine-containing polymer and a polymer having a first crosslinkable group and a kinematic viscosity of 30 to 150 mm ２ Patent Document 1 discloses a coating material containing a polydimethylsilicone (a / s), an acrylic silicone having a second crosslinkable group, and a curing agent having a reactive group capable of reacting with the first crosslinkable group and the second crosslinkable group. By using this coating material, an antifouling coating film with excellent warm water resistance can be produced.

[0003] Japanese Patent Application Laid-Open No. 2023-52716

[0004] It is preferable to reduce the amount of paint applied to the surface of the substrate to be coated, so that the paint can be applied inexpensively. However, since the paint film can protect the surface of the substrate by applying it to the surface of the substrate to a predetermined film thickness, it is necessary to ensure that the paint film has a predetermined film thickness after the applied paint has hardened, and the amount of paint applied cannot be reduced unconditionally. Furthermore, if the specific surface area of ​​the substrate to which the paint is applied is large and the paint is applied to the entire surface, the weight of the substrate including the hardened paint film will increase.

[0005] Additionally, lacquer thinner, urethane thinner, epoxy thinner, acrylic thinner, and melamine thinner are used as organic solvents to adjust paint viscosity. These thinners contain toxic substances, such as toluene, xylene, isopropyl alcohol, 1-butanol, and methanol, which volatilize and can cause physical symptoms such as numbness in the hands and feet, dizziness, chronic bronchitis, peripheral neuritis, optic atrophy, liver damage, and brain damage in humans who inhale them. Therefore, other methods for adjusting paint viscosity without using thinners are desirable. Furthermore, water-based paints, which require water to adjust viscosity, contribute to the global water shortage.

[0006] An object of the present invention is to provide a paint that can be applied inexpensively and that can reduce the amount of paint applied to the surface of a substrate to be coated. Another object of the present invention is to provide a paint that can form a coating film that minimizes the weight increase of the substrate. Another object of the present invention is to provide a paint whose viscosity can be adjusted by a means that does not adversely affect the human body and whose viscosity can be easily adjusted even in low-temperature environments. Another object of the present invention is to provide a paint manufacturing method for a paint that can be applied inexpensively and that minimizes weight increase. Another object of the present invention is to provide buildings, vehicles, industrial products, furniture, and fixtures coated with a paint that can be applied inexpensively and that can form a coating film that minimizes weight increase.

[0007] The first premise of the present invention for solving the above-mentioned problems is a coating material that is applied to the surface of a substrate to be coated and forms a coating film on the surface of the substrate.

[0008] A feature of the paint of the present invention in the first premise is that microbubbles and / or nanobubbles are introduced into the paint, and the microbubbles and / or nanobubbles are dispersed and mixed inside the paint at a predetermined concentration.

[0009] An example of the paint of the present invention is a paint having an average particle diameter D of microbubbles and / or nanobubbles. ５０ is 100 μm or less.

[0010] Another example of the paint of the present invention is a paint having an average particle diameter D of microbubbles and / or nanobubbles. ５０ is 0.5 μm or less.

[0011] Another example of the paint of the present invention is a paint containing 10 microbubbles and / or nanobubbles per ml of paint. ５ pcs / ml or more 10 １２ The number is less than 1 / ml.

[0012] In another example of the paint of the present invention, microbubbles and / or nanobubbles are in Brownian motion inside the paint.

[0013] In another example of the paint of the present invention, the viscosity of the paint after the introduction of microbubbles and / or nanobubbles is lower than that of the paint before the introduction of microbubbles and / or nanobubbles.

[0014] In another example of the paint of the present invention, the viscosity of the paint after the introduction of microbubbles and / or nanobubbles is in the range of 1 to 1000 mPa·s.

[0015] In another example of the present invention, the gas that forms microbubbles and / or nanobubbles is any one of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide, or a mixed gas of two or more of these.

[0016] Another example of the paint of the present invention is a paint that is any one of a fluororesin paint, a silicone resin paint, an acrylic resin paint, a urethane resin paint, and a water-based paint.

[0017] A second premise of the present invention for solving the above problem is a paint manufacturing method for manufacturing the paint.

[0018] A feature of the coating material production method of the present invention in the second premise is that the coating material production method utilizes any one of a pressurized dissolution method, a micropore and porous method, an ejector method, a Venturi method, an ultrasonic method, a static mixer method, a cavitation method, a swirling liquid flow method, and a shear method, or a combination of these methods, to introduce microbubbles and / or nanobubbles into the coating material.

[0019] In another example of the present invention, the object to be coated with the paint is a building, the paint is applied to the surface of the building, and the hardened paint forms a coating on the surface of the building.

[0020] In another example of the present invention, the object to be coated with the paint is a moving body, the paint is applied to the surface of the moving body, and the hardened paint forms a coating on the surface of the moving body.

[0021] In another example of the present invention, the object to be coated with the paint is an industrial product, the paint is applied to the surface of the industrial product, and the hardened paint forms a coating film on the surface of the industrial product.

[0022] In another example of the present invention, the object to which the paint is applied is furniture or equipment, the paint is applied to the surface of the furniture or equipment, and the hardened paint forms a coating on the surface of the furniture or equipment.

[0023] According to the paint of the present invention, microbubbles and / or nanobubbles are introduced into the paint, and the closed-cell microbubbles and / or nanobubbles are dispersed and mixed (dispersed and dissolved) within the paint at a predetermined concentration, so that the microbubbles and nanobubbles can reduce the proportion of the paint itself per unit volume of the paint, and the amount of paint applied to the surface of the substrate to be coated is reduced, making it possible to reduce the amount of paint applied to the substrate. Compared to paint without dispersed microbubbles and / or nanobubbles in the paint, the reduced amount applied reduces the unit cost of the paint per unit area of ​​the substrate surface, making it possible to apply the paint inexpensively.

[0024] Average particle size D of microbubbles and / or nanobubbles ５０ The paint having an average particle size D ５０ Since microbubbles and / or nanobubbles having an average particle diameter D of 100 μm or less are dispersed and mixed (dispersed and dissolved) in the paint at a predetermined concentration, the proportion of the paint itself per unit area in the paint can be reduced by the microbubbles of fine bubbles and the nanobubbles of ultrafine bubbles, and the amount of paint itself applied when the paint is applied to the surface of the substrate to be coated can be reliably reduced. ５０ By including microbubbles or nanobubbles, the amount of paint applied to the substrate can be reduced, which reduces the unit cost of paint per unit area of ​​the substrate surface, allowing the paint to be applied inexpensively.

[0025] Average particle size D of microbubbles and / or nanobubbles ５０ The average particle size D is 0.5 μm or less. ５０Since microbubbles and / or nanobubbles having an average particle size D of 0.5 μm or less are dispersed and mixed (dispersed and dissolved) in the paint at a predetermined concentration, the proportion of the paint itself per unit area in the paint can be reduced by the microbubbles of fine bubbles and the nanobubbles of ultrafine bubbles, and the amount of paint itself applied when the paint is applied to the surface of the substrate to be coated can be reliably reduced. ５０ By including microbubbles or nanobubbles, the amount of paint applied to the substrate can be reduced, which reduces the unit cost of paint per unit area of ​​the substrate surface, allowing the paint to be applied inexpensively.

[0026] The microbubbles and / or nanobubbles contained in 1 ml of paint are 10 ５ pcs / ml or more 10 １２ In the case of a paint having a microbubble density of 10 or less per ml, the microbubbles and nanobubbles contained in 1 ml of the paint in which the microbubbles and / or nanobubbles are dispersed and mixed are within the above range, so that a large amount of fine microbubbles and ultrafine nanobubbles are dispersed and mixed (dispersed and dissolved) at a predetermined concentration inside the paint, and the proportion of the paint itself per unit area in the paint can be reduced by the fine microbubbles and ultrafine nanobubbles, and the amount of paint itself applied when the paint is applied to the surface of the substrate to be coated can be reliably reduced. ５ pcs / ml or more 10 １２ By including microbubbles and / or nanobubbles in the paint in a range of 1 / ml or less, the amount of paint applied to the substrate can be reduced, which reduces the unit cost of the paint per unit area of ​​the substrate surface, allowing the paint to be applied inexpensively.

[0027] In paints in which microbubbles and / or nanobubbles undergo Brownian motion inside the paint, the adhesiveness is reduced by the nanobubbles undergoing Brownian motion inside the paint, and the nanobubbles dissolve, cutting the bonds between molecules and weakening the interactions between molecules, thereby reducing the viscosity of the paint. ５０By adjusting the content of microbubbles or nanobubbles in a paint, the viscosity of the paint can be adjusted and the ease of application of the paint to the surface of a substrate can be improved. The amount of organic solvents such as thinners used to adjust the viscosity of the paint can be reduced or eliminated, making it possible to adjust the viscosity without reducing the amount of substances that may be harmful to the human body. By using microbubbles and / or nanobubbles to adjust the viscosity of a paint, particularly in low-temperature environments where the viscosity of the paint is high and a larger amount of thinner or the like is used to adjust the viscosity, it is possible to provide a paint that significantly reduces or eliminates the use of substances that may be harmful to the human body.

[0028] In paints in which the viscosity of microbubbles and / or nanobubbles is lower than that of the paint before the introduction of microbubbles and / or nanobubbles can be reduced by the microbubbles and / or nanobubbles dispersed (dissolved) in the paint, thereby lowering the viscosity of the paint after the introduction of microbubbles and / or nanobubbles compared to that of the paint before the introduction of microbubbles and / or nanobubbles, thereby improving the ease of application of the paint to the surface of a substrate after the introduction of microbubbles and / or nanobubbles. The viscosity of paints can be reduced by introducing microbubbles and / or nanobubbles into the paint, thereby converting high-viscosity or medium-viscosity paints into low-viscosity paints, reducing or eliminating the use of substances that may be harmful to the human body. By using microbubbles and / or nanobubbles to adjust the viscosity of paints, particularly in low-temperature environments where the viscosity of paints is high and more thinners or the like are used to adjust the viscosity, it is possible to provide paints that significantly reduce or eliminate the use of substances that may be harmful to the human body.

[0029] In paints having a viscosity in the range of 1 to 1,000 mPa·s after the introduction of microbubbles and / or nanobubbles, the viscosity of the paint can be reduced by the microbubbles and nanobubbles dispersed and mixed (dispersed and dissolved) in the paint, making it possible to lower the viscosity of the paint containing microbubbles and / or nanobubbles within the above range, thereby reliably improving the ease of application of the paint to the surface of a substrate.The viscosity of paint can be lowered by introducing microbubbles and / or nanobubbles into it, and high- or medium-viscosity paints can be converted into low-viscosity paints with reduced or no use of substances that may have adverse effects on the human body.

[0030] In paints in which the gas that forms microbubbles and / or nanobubbles is any one of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide, or a mixed gas of two or more of these, a large number of microbubbles and nanobubbles, which are ultrafine bubbles made from the exemplified gases or mixed gases of these gases, are dispersed and mixed (dispersed and dissolved) inside the paint, and the proportion of the paint itself per unit area of ​​the paint can be reduced by the fine microbubbles and ultrafine nanobubbles, and the amount of paint itself applied when the paint is applied to the surface of a substrate to be coated is reduced, allowing the amount of paint applied to the substrate to be reduced.In addition, the reduced amount applied reduces the unit price of the paint per unit area of ​​the substrate surface, making it possible to coat the surface of the substrate with paint inexpensively. The viscosity of the paint can be reduced by the microbubbles or nanobubbles of the exemplified gases or mixed gases of these gases, thereby improving the ease of application of the paint to the surface of the substrate. The viscosity of the paint varies depending on the type of gas that forms the microbubbles or nanobubbles, and the viscosity of the paint can be finely adjusted by selecting the gas used.

[0031] In paints that are fluororesin paints, silicone resin paints, acrylic resin paints, urethane resin paints, or water-based paints, the proportion of the paint itself per unit volume can be reduced by microbubbles or nanobubbles, thereby reducing the amount of paint applied to the surface of the substrate to be coated, and thereby reducing the amount of paint applied to the substrate. Compared to paints that do not contain dispersed microbubbles and / or nanobubbles, the reduced amount of paint applied reduces the unit cost of the paint per unit area of ​​the substrate surface, allowing the paint to be applied inexpensively. Even if a substrate bearing a fluororesin coating film made from a fluororesin paint, a silicone resin coating film made from a silicone resin paint, an acrylic resin coating film made from an acrylic resin paint, a urethane resin coating film made from a urethane resin paint, or a water-based paint coating film made from a water-based paint is damaged, the coating film made from the paint can protect the substrate from various damages and prevent deterioration of the substrate due to the damage. Furthermore, when the paint is a water-based paint, the amount of water used to adjust the viscosity can be reduced or there is no need to use water to adjust the viscosity, making it a useful paint in areas with water shortages or environments where water cannot be used.

[0032] A paint production method for introducing microbubbles and / or nanobubbles into paint by utilizing any one of a pressurized dissolution method, a micropore and porous method, an ejector method, a Venturi method, an ultrasonic method, a static mixer method, a cavitation method, a swirling flow method, and a shear method, or a combination of these methods, can reliably introduce microbubbles and / or nanobubbles into the paint, thereby producing a paint that can be applied to a substrate in a reduced amount and can be applied inexpensively.The paint production method can produce a paint that can be made to have a low viscosity and can improve the ease of application to the surface of a substrate.

[0033] When a building is coated with a paint containing microbubbles and / or nanobubbles, the paint is applied to the building's surface, and the cured paint forms a coating film on the building's surface. When the paint containing closed-cell microbubbles and / or nanobubbles dispersed (dissolved) at a predetermined concentration is applied to the building's surface, the amount of paint itself applied is reduced. This reduction in the amount applied reduces the unit price of the paint per unit area of ​​the building's surface, allowing the paint to be applied inexpensively to the building's surface and reducing the building's construction costs. The dispersed (dissolved) microbubbles in the paint applied to the building's surface reduces the viscosity of the paint, making it easier to apply the paint to the building's surface and shortening the time required to apply the paint to the building's surface. The mass of the paint per unit volume is reduced compared to when nanobubbles are not dispersed (dissolved) in the paint, minimizing the increase in the weight of the building, including the coating film formed from the paint, when the paint is applied to the building's surface.

[0034] When a mobile object is coated with a paint containing microbubbles and / or nanobubbles, the paint containing the microbubbles and / or nanobubbles dispersed (dissolved) at a predetermined concentration is applied to the surface of the mobile object, forming a coating film on the surface of the mobile object. The amount of paint applied to the surface of the mobile object containing the dispersed (dissolved) microbubbles and / or nanobubbles at a predetermined concentration reduces the amount of paint itself applied. This reduction in the amount of paint applied reduces the unit cost of the paint per unit area of ​​the mobile object's surface, allowing the paint to be applied inexpensively and reducing the manufacturing cost of the mobile object. The dispersed (dissolved) microbubbles in the paint applied to the surface of the mobile object reduce the viscosity of the paint, making it easier to apply the paint to the surface of the mobile object and shortening the time required to apply the paint to the surface of the mobile object. The mass of the paint per unit volume of the mobile object is reduced compared to when the nanobubbles are not dispersed (dissolved) in the paint, minimizing the increase in the weight of the mobile object, including the coating film formed from the paint, when the paint is applied to the surface of the mobile object.

[0035] When an industrial product is coated with a paint containing microbubbles and / or nanobubbles, the paint is applied to the surface of the industrial product, and the cured paint forms a coating film on the surface of the industrial product. When the paint containing closed-cell microbubbles and / or nanobubbles dispersed (dissolved) at a predetermined concentration is applied to the surface of the industrial product, the amount of paint itself applied is reduced. This reduction in the amount applied reduces the unit price of the paint per unit area of ​​the industrial product's surface, allowing the paint to be applied inexpensively and reducing the manufacturing cost of the industrial product. The dispersed (dissolved) microbubbles in the paint applied to the surface of the industrial product reduce the viscosity of the paint, making it easier to apply the paint to the surface of the industrial product and shortening the time required to apply the paint to the surface of the industrial product. The mass of the paint per unit volume of the industrial product is reduced compared to when nanobubbles are not dispersed (dissolved) in the paint, minimizing the increase in the weight of the industrial product, including the coating film formed from the paint, when the paint is applied to the surface of the industrial product.

[0036] When the paint containing microbubbles and / or nanobubbles is applied to furniture or fixtures, and the hardened paint forms a coating on the surface of the furniture or fixture, the amount of paint applied to the furniture or fixture surface is reduced when the paint containing closed-cell microbubbles and / or nanobubbles dispersed and mixed (dispersed and dissolved) at a predetermined concentration is applied to the furniture or fixture surface, and this reduced amount of paint applied reduces the unit price of the paint per unit area of ​​the furniture or fixture surface, allowing the paint to be applied inexpensively to the furniture or fixture surface and reducing the manufacturing costs of the furniture or fixture. The dispersed and dissolved microbubbles in the paint applied to the furniture or fixture surface reduce the viscosity of the paint, making it easier to apply the paint to the furniture or fixture surface and shortening the work time required to apply the paint to the furniture or fixture surface. The mass of paint per unit volume of furniture and fixtures is reduced compared to when nanobubbles are not dispersed and mixed (dispersed and dissolved) in the paint, so when paint is applied to the surfaces of furniture and fixtures, the increase in weight of the furniture and fixtures, including the coating film formed from the paint, can be minimized.

[0037] FIG. 1 is a configuration diagram showing an example of a gas introducing device that mixes microbubbles and / or nanobubbles into paint. FIG. 2 is a configuration diagram showing an example of a static fluid mixing device among gas introducing devices. FIG. 3 is an image diagram showing an example of the structure of a fluororesin coating film. FIG. 4 is an image diagram showing an example of the structure of a silicone resin coating film. FIG. 5 is an image of microbubbles and nanobubbles dispersed and mixed (dispersed and dissolved) inside the paint. FIG. 6 is an image of microbubbles and nanobubbles dispersed and mixed (dispersed and dissolved) inside the coating film formed by curing the paint. FIG. 7 is a diagram explaining the drying process of emulsion-based paint. FIG. 8 is a diagram explaining the drying process of solvent-based paint. FIG. 9 is a diagram showing examples of a paint of the present invention and comparative examples to the paint of the present invention.

[0038] The paint and paint manufacturing method according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram illustrating an example of a gas introduction device 16 for mixing microbubbles 14 and / or nanobubbles 15 into paint 10A. FIG. 2 is a diagram illustrating an example of a static fluid mixer 21 included in the gas introduction device 16. FIG. 3 is a conceptual diagram illustrating an example of the structure of a fluororesin coating film. FIG. 4 is a conceptual diagram illustrating an example of the structure of a silicone resin coating film. FIG. 5 is a diagram illustrating an image of microbubbles 14 and nanobubbles 15 dispersed and mixed (dissolved) within paint 10. FIG. 6 is a diagram illustrating an image of microbubbles 14 and nanobubbles 15 dispersed and mixed (dissolved) within coating film 13 formed by curing paint 10. FIG. 7 is a diagram illustrating the drying process of emulsion-based paint 10B. FIG. 8 is a diagram illustrating the drying process of solvent-based paint 10B. 5 and 6 show the microbubbles 14 and nanobubbles 15 as images that are visible to the naked eye, but in reality, it is difficult to visually observe the microbubbles 14 and it is impossible to visually observe the nanobubbles 15.

[0039] The paint 10B having microbubbles 14 and / or nanobubbles 15 dispersed therein is applied to the surface 12 (external surface, internal surface) of the substrate 11 (building, mobile object, industrial product, furniture, fixture, etc.) to be coated. The hardened paint 10B forms a coating film 13 that covers the surface 12 of the substrate 11. As the paint 10A before the microbubbles 14 and / or nanobubbles 15 are mixed in, any of fluororesin paint, silicone resin paint (silicone resin), acrylic resin paint, urethane resin paint, and water-based paint is used. The interior (inside) of the paint 10B (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, water-based paint) contains particles with an average particle size D (described later). ５０ is 100 μm or less, preferably, the average particle size D ５０ is 0.5 μm or less, more preferably, the average particle size D ５０ The microbubbles 14, which are independent fine bubbles having a diameter of 0.2 μm or less, or the nanobubbles 15, which are independent ultrafine bubbles, are dispersed and mixed (dispersed and dissolved) at a predetermined concentration, or the average particle diameter D ５０ is 100 μm or less, preferably, the average particle size D ５０is 0.5 μm or less, more preferably, the average particle size D ５０ The nanobubbles 15 are dispersed and mixed (dispersed and dissolved) at a predetermined concentration. ５０ is in the range of 1 to 800 nm.

[0040] The fluororesin paint is applied to the surface 12 of the substrate 11 and then hardens to form a fluororesin coating film 13 having a predetermined thickness. The silicone resin paint is applied to the surface 12 of the substrate 11 and then hardens to form a silicone resin coating film 13 having a predetermined thickness. The acrylic resin paint is applied to the surface 12 of the substrate 11 and then hardens to form an acrylic resin coating film 13 having a predetermined thickness. The urethane resin paint is applied to the surface 12 of the substrate 11 and then hardens to form a urethane resin coating film 13 having a predetermined thickness. The water-based paint is applied to the surface 12 of the substrate 11 and then hardens to form a water-based paint coating film 13 having a predetermined thickness.

[0041] Fluorine resin paint is a paint whose main component is fluororesin. The fluororesin that is the main component of fluororesin paint is one of PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylenepropene copolymer), and ETFE (ethylene-tetrafluoroethylene copolymer), or a solution of a blend of two or more of these. It is also possible to use a high-temperature modified fluororesin that increases adhesion to the surface 12 of the substrate 11 and improves abrasion resistance without reducing its heat resistance, or a low-temperature modified fluororesin that can be processed at low temperatures while taking advantage of the low friction and non-stick properties of fluororesin.

[0042] The molecular structure of PTFE (polytetrafluoroethylene) is represented by the following general formula (1).

[0043] PTFE has a molecular structure in which carbon atoms (C) and fluorine atoms (F) are bonded in a linear chain, and the bonds between the carbon atoms are tightly covered with fluorine atoms, providing protection. The arrangement of atoms within the PTFE molecule is tight and symmetrical, resulting in very little charge polarization. Furthermore, it is a polymer made up of extremely long molecular chains with a molecular weight of one million to tens of millions. Stable due to this characteristic molecular structure, PTFE forms a coating film 13 with excellent non-adhesive properties, water and oil repellency, low friction, heat resistance, chemical resistance, electrical properties, flame retardancy, and weather resistance. PTFE has a density of 2.13 to 2.20 g / cm. ３ Its room temperature hardness is F to 2H, and its water repellency angle (°) water / oil (nHD) is 110-115 / 45-50.

[0044] The molecular structure of PFA (perfluoroalkoxyalkane) is represented by the following general formula (2).

[0045] PFA is a copolymer of tetrafluoroethylene (TFE) and perfluoroalkyl vinyl ether (PFVE). Its key features include low viscosity when molten and properties comparable to those of PTFE. Like PTFE, it has excellent heat resistance, with a continuous use temperature of 260°C, and is resistant to most chemicals, including strong acids, strong alkalis, and organic solvents. PFA forms an organic coating film with excellent non-stick properties, heat resistance, cold resistance, water repellency, chemical resistance, electrical properties, flame retardancy, and weather resistance. PFA's room temperature hardness is F-H, and its water / oil repellency angle (°) is 110-115 / 45-50.

[0046] The molecular structure of FEP (perfluoroethylene propene copolymer) is represented by the following general formula (3).

[0047] FEP is a copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), and contains a trifluoromethyl group (CF) in the molecular chain. ３It has the characteristics of a low melting point while having the same non-stickiness and chemical resistance as PTFE. Because FEP has a low melt viscosity, when used for coating, it can create a continuous film without pinholes. FEP has a density of 2.15 to 2.17 g / cm ３ Its room temperature hardness is F to H, and its water repellency angle (°) water / oil (nHD) is 110-115 / 45-50.

[0048] The molecular structure of ETFE (ethylene-tetrafluoroethylene copolymer) is represented by the following general formula (4).

[0049] ETFE is a copolymer of tetrafluoroethylene and ethylene, and contains hydrogen atoms (H) in its molecular structure. Therefore, compared to PTFE and FEP, it has lower chemical resistance and heat resistance, with a continuous use temperature of 150°C. On the other hand, it has high mechanical strength and can be processed at a low melting point. ETFE has a density of 1.73 to 1.75 g / cm ３ is in the range.

[0050] Silicone resin paint is a paint whose main component is silicone resin. The molecular structure of silicone resin (silicone resin), which is the main component of silicone resin paint, is represented by the following general formula (5).

[0051] Silicone resin paints have excellent durability, water resistance, chemical resistance, and flexibility, and form a coating film 13 (a three-dimensional glass skeleton coating) with high adhesion to the surface 12 of the substrate 11. The silicone resin coating film 13 made from silicone resin paint is composed of siloxane bonds (Si-O, silicon-oxygen) and contains several silicates (SiO4 / 2) or silsesquioxanes (R-SiO3 / 2). R represents various alkyl groups or allyl groups, with typical functional groups being methyl or phenyl. Compared to organic resins composed of carbon bonds (C-C), silicone resin paints exhibit greater resistance to decomposition by heat and radiation. The resistance of silicone resin coatings is due to the strength of their oxygen-hydrogen bonds (82.6 kcal / mol for carbon-carbon bonds, compared to 108 kcal / mol for silicon-oxygen bonds), their ability to transmit visible and ultraviolet light, and their inherently partially oxidized structure.

[0052] The addition of organic functional groups gives siloxane polymers a more linear structure, imparting physical properties (e.g., flexibility) and performance inherent to the organic functional groups. The introduction of phenyl groups into the siloxane backbone enhances compatibility with organic resins, increases toughness, and maintains thermal stability at moderate temperatures (250°C). Meanwhile, methyl groups enhance curing, thermal shock resistance, and reduce weight loss under extreme humidity conditions. Silicone polymer coating solutions (silicone resins) are produced by hydrolysis of chlorosilanes or alkoxysilanes, forming highly reactive silanol groups (Si-OH). RSiCl3 + 3H2O, RSi(OH)3 + 3HCl, RSi(OR')3 + 3H2O, RSi(OH)3 + 3R'OH. The initial condensation reaction forms siloxane oligomer structures. 2 RSi(OH)3 RSi(OH)2 - O - SiR(OH)2 + H2 O. Further condensation leads to the formation of a three-dimensional crosslinked siloxane structure. The addition of heat and catalysts during the condensation reaction increases the molecular weight and improves physical properties. On the other hand, the viscosity of the polymer increases, necessitating dilution in a solvent. Similarly, in cases where specific application characteristics are required, the reaction of the hydroxyl groups of the organic resin (e.g., polyester) with the silanol and alkoxy groups forms a silicone-organic resin composite, improving performance depending on the degree of siloxane modification. Cold blending of the resin intermediate with the organic resin can be carried out using less solvent. However, a higher and longer thermal curing step is required to advance the reaction and ensure complete cure. In addition to selecting the optimal silicone resin, the other ingredients in the formulation play an important role in the coating's performance.

[0053] When creating a prototype silicone resin coating, the first step is to determine the required characteristics for the intended application and then determine which resin binder can be used. The heat, chemicals, and UV exposure the silicone resin coating will be exposed to during curing, as well as the desired physical properties, also influence the choice of resin binder. Silicone resin coatings contribute to improving the silicone resin coating's heat resistance, chemical resistance, and UV resistance, but other performance and physical properties can also be imparted by combining silicone with specific organic binders (film hardness: phenolic and melamine resins; room-temperature drying: acrylic resins; corrosion resistance: epoxy resins; toughness: alkyd resins). The amount of silicone in the coating formulation is determined based on the performance requirements for the application.

[0054] Silicone resin coatings contain a catalyst, curing conditions, solvent, and thinner formulation. Silanol-functional resins heat cure without the addition of a catalyst. However, the addition of metal driers (e.g., zinc, iron, or cobalt octoate) accelerates the cure. Typical catalyst loadings are 0.1-0.2% metal based on resin solids. Silicone resin coatings formulated with silanol-functional silicone resins require heat curing for optimal coating performance, but the cure time varies depending on the silicone content and the curing conditions of the other major ingredients. The cure method for 100% silicone resin systems is 232°C (450°F) for 30 minutes or 204°C (400°F) for 60 minutes. Silicone resin coatings (silicone resins) can be used in aromatic hydrocarbons (e.g., toluene, xylene), ketones, esters, acetates, and chlorinated solvents. Small additions (less than 5%) of glycol ethers and alcohols (e.g. butanol) improve the stability of silicone resins.

[0055] Acrylic resin paint is a paint whose main component is acrylic resin. Acrylic resin paint forms an acrylic resin coating film 13 that has excellent weather resistance, gloss, transparency, water resistance, adhesion, and corrosion resistance. Water-based acrylic resins and solvent-based acrylic resins can be used. Water-based acrylic resins include acrylic emulsions, acrylic-styrene emulsions, hydroxyl-containing acrylic emulsions, room-temperature-drying water-soluble acrylic resins, baking acrylic dispersions, and hydroxyl-containing acrylic dispersions. Solvent-based acrylic resins include isocyanate-curing acrylic resins, room-temperature / forced-drying acrylic resins, melamine-baking acrylic resins, and moisture-curing silicone acrylic resins. Organic solvents include dibutyl ether, turpentine oil, benzene, and toluene.

[0056] The urethane resin paint is composed of a polyol having multiple hydroxyl groups and a polyisocyanate as the main component. The urethane resin paint may be an acrylic urethane paint whose main component is an acrylic polyol. The urethane resin paint may also contain an acrylic polyol and cellulose acetate butyrate. The urethane resin paint forms a urethane resin coating film 13 with excellent coating performance, finish, weather resistance, adhesion, flexibility, and chemical resistance. The urethane resin paint can be diluted with an organic solvent. Examples of the organic solvent include alcohol-based, carboxylic acid ester-based, ketone-based, amide-based, aliphatic, and aromatic hydrocarbon-based solvents.

[0057] Examples of polyols that can be used include 1,6-hexanediol, cyclohexyldimethanol, neopentyl glycol, butylethylpropanediol, trimethylolethane, trimethylolpropane, polycaprolactone triol, ditrimelylpropane, pentaerythritol, polycaprolactone tetraol, dipentaerythritol, sorbitol, and mannitol. Also, a mixture of at least two of these may be used.

[0058] For the polyisocyanate, a difunctional or higher isocyanate compound is used. Examples of difunctional isocyanate compounds include hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 4,4-dicyclohexyl diisocyanate. Examples of trifunctional or higher isocyanate compounds are those synthesized using diisocyanate compounds as starting materials, such as biuret compounds, trimethylolpropane adduct compounds, isocyanurate compounds, and allophanate compounds. In order to increase the crosslink density of urethane resin coating films made from urethane resin paints and improve the weather resistance and stain resistance of the coating films, it is preferable that the polyisocyanate be a trifunctional or higher isocyanate compound.

[0059] Examples of trifunctional or higher isocyanate compounds that can be used include biuret hexamethylene diisocyanate, adducts of hexamethylene diisocyanate, isocyanurates of hexamethylene diisocyanate, blocked isocyanates, trimethylolpropane adducts of 1,3-bis(isocyanatomethyl)cyclohexane, isocyanurates of 1,3-bis(isocyanatomethyl)cyclohexane, trimethylolpropane adducts of isophorone diisocyanate, and allophanates of hexamethylene diisocyanate. Also, a mixture of at least two of these isocyanate compounds can be used. For water-based paints, emulsions, emulsions containing aggregates, or water-soluble resins can be used.

[0060] Fluorocarbon resin paints, silicone resin paints, acrylic resin paints, urethane resin paints, and water-based paints contain various additives and pigments as needed. Additives include matting agents to reduce the gloss of the paint film, surfactants to prevent a decrease in surface tension, anti-sagging agents to prevent paint from running off, color-stabilizing agents to prevent uneven color caused by pigment mixing, preservatives and mildew inhibitors to prevent corrosion of the paint film, plasticizers to improve the paint's flexibility and adhesion, anti-skinning agents to prevent the formation of a skin on the surface during paint storage, and leveling agents to ensure the fluidity of the paint film. Additives include curing agents that harden the paint film and improve its weather resistance, water resistance, chemical resistance, heat resistance, and other properties. Curing agents include blocked isocyanates such as hexamethylene isocyanate trimer or their emulsified dispersions, melamine resins such as methylated melamine, methylolated melamine, and butylolated melamine, and urea resins such as methylated urea and butylated urea. Pigments include inorganic color pigments, organic color pigments, and extender pigments. Fluorocarbon resin paints, silicone resin paints, acrylic resin paints, and urethane resin paints are available in both water-based and oil-based, one-component and two-component forms. Other additives may also be added, such as film-forming aids, thickeners, light stabilizers, design agents, surface conditioners, and aqueous media. Aqueous media are used to dilute aqueous dispersions. Thickeners used include urethane-based thickeners, polyacrylic-based thickeners, polyamide-based thickeners, cellulose-based thickeners, and clay mineral thickeners such as bentonite. The fluorocarbon resin coating film 13 made from fluorocarbon resin paint, the silicone resin coating film 13 made from silicone resin paint, the acrylic resin coating film 13 made from acrylic resin paint, the urethane resin coating film 13 made from urethane resin paint, and the coating film 13 made from water-based paint have a water contact angle of 60° or less. The water contact angle is measured by dropping a water droplet with a diameter of 1 to 2 mm onto the coating film 13, photographing the droplet with a video camera after 30 seconds, and analyzing the image. The water contact angle is defined as twice the angle between the line connecting the apex and end point of the droplet and the coating film 13.

[0061] As a means for introducing (mixing) microbubbles 14 or nanobubbles 15 into a paint, any of the following methods can be used: pressurized dissolution, micropore and porous, ejector, Venturi, ultrasonic, static mixer, cavitation, swirling liquid flow, and shear. Note that these methods can also be combined to introduce microbubbles 14 or nanobubbles 15 into a paint.

[0062] The pressurized dissolution method uses a pressurized pump (with pressure gauges on both the suction and discharge sides) to circulate the paint (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint) in a reservoir. At the same time, gas (one or more of the following: air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) is drawn into the pump's suction line. The gas is drawn into the pump by attaching a valve to restrict the flow path, generating negative pressure and allowing the gas to self-suck. The gas-liquid mixed flow with the paint is agitated by the pump and pressurized through the discharge line in the dissolution tank, resulting in dissolution. Any excess gas that remains undissolved is released into the atmosphere.

[0063] In the micropore and porous methods, a porous body in which glass, metal, ceramic, or the like is sintered or weakly bonded to form micropores, or a porous body in which a glass tube or the like is stretched thin, or a porous membrane is placed in a pressurized paint (any of fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, and water-based paint), and pressurized gas (one or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) is sent into the porous body or porous membrane, causing the gas to be ejected as bubbles from the micropore outlets, and furthermore, by applying a liquid flow, the bubbles are broken to generate fine bubbles of microbubbles 14 and ultrafine bubbles of nanobubbles 15, and the microbubbles 14 and nanobubbles 15 are mixed into the paint. In the micropore and porous methods, the bubble size can be adjusted by adjusting the liquid flow rate and the gas supply pressure.

[0064] The ejector system consists of a nozzle, negative pressure chamber, mixing chamber, and energy conversion unit. A high-speed liquid jet from the nozzle draws gas (one or more of the following: air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) into the negative pressure chamber, where it reaches maximum negative pressure. If the pressure drops below the saturated vapor pressure, cavitation occurs, and the gas and liquid are mixed and introduced into the mixing chamber. Here, the pressure is restored through turbulent mixing due to the large shearing action, breaking the gas into fine bubbles, which are then introduced into the energy conversion unit as a gas-liquid multiphase flow. In the energy conversion section, the microbubbles contract, expand, collapse, and collapse (cavitation collapse may accompany shock waves), generating fine microbubbles 14 and ultrafine nanobubbles 15, which are then mixed into the paint (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint). In the ejector system, to effectively generate microbubbles, the nozzle diameter and the diameter of the mixing chamber must be precisely aligned with the central axis, and the ratio between the nozzle diameter and the diameter of the mixing chamber, the structures of the nozzle and negative pressure chamber, and the structural balance of the energy conversion section are all important, and the microbubble characteristics differ depending on these structures.

[0065] In the Venturi method, paint (either fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint) and gas (one or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) are simultaneously flowed through a Venturi tube that has a narrowed portion called a throat in the middle of the fluid flow path, and shock waves generated by a sudden change in the liquid flow rate crush the bubbles, generating fine bubbles of microbubbles 14 and ultrafine bubbles of nanobubbles 15, and the microbubbles 14 and nanobubbles 15 are mixed into the paint. In the Venturi system, the flow velocity of bubbles dissolved in the paint fluid accelerates at the contraction section (smallest constriction section), and the pressure is suddenly reduced (cavitation occurs when the pressure falls below the saturated vapor pressure of the paint), causing the bubbles to expand temporarily, but then collapse (crush) due to a sudden increase in pressure in the expansion section downstream, breaking the bubbles down into finer bubbles. In the Venturi tube system (gas-liquid two-phase flow), the flow velocity accelerates at the contraction section (constriction section) of the Venturi tube, causing the pressure to decrease, causing the bubbles to expand, and then in the expansion section downstream, the bubbles become even more supersonic, and the further reduction in pressure causes the bubbles to expand. However, in the expansion section downstream, the pressure suddenly increases, causing the bubbles to contract, collapse, and form shock waves, generating micro-nano bubbles 14 and nano bubbles 15. In the Venturi system, in order to achieve the desired bubble atomization performance, the bubbles must expand due to a sufficient pressure reduction at the contraction part of the Venturi tube, followed by a rapid pressure recovery that leads to their violent collapse, and therefore the flow velocity at the inlet must be sufficiently fast.Furthermore, the flow velocity must exceed a predetermined value to efficiently atomize the bubbles.

[0066] The ultrasonic system consists of a hollow ultrasonic horn, an ultrasonic vibrator, a vibration circuit, and a gas supply. The hollow ultrasonic horn has a stepped cylindrical shape with a gas flow path inside, and ultrasonic vibrations are amplified according to the area ratio between the large end and small end faces. Gas (one or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) passes through a gas inlet on the side of the hollow ultrasonic horn and is released into the paint (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint) through a gas outlet on the ultrasonic vibration surface. The gas supply uses a regulator, valve, and flow meter to adjust the supply volume and pressure of gas from a gas cylinder. In the ultrasonic method, the tip of a hollow ultrasonic horn is inserted into the paint, and the hollow ultrasonic horn is ultrasonically vibrated while supplying gas. The gas-liquid interface formed at the tip of the hollow ultrasonic horn is finely divided by the disturbance caused by the ultrasound, and microbubbles 14 and nanobubbles 15 are mixed into the paint.

[0067] The static mixer method generates a high-speed rotating fluid by passing a gas-liquid mixture (or a fluid in which gas is dissolved at a high concentration under pressure) through a specially designed nozzle with a guide vane or screw that generates a strong swirling flow inside and a row of mushroom-shaped projections (current cutters) on the inner wall. The high-speed rotating fluid collides with the projections (current cutters) protruding from the inner wall of the pipe, generating cavitation and shock waves due to the strong shearing action and large negative pressure. A negative pressure recirculation region is formed in the center of the high-speed rotating fluid, which is subdivided by the cavitation and shock waves behind the projections. These flows are then recirculated, promoting turbulent mixing of the gas-liquid two-phase flow, generating fine bubbles of microbubbles 14 and ultrafine bubbles of nanobubbles 15, which are then mixed into the paint.

[0068] The cavitation method sends a gas-liquid mixture into the pump and uses cavitation to generate bubbles, and the microbubbles or nanobubbles generated by the cavitation are mixed into paint (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint). In the cavitation method, when the flow path is suddenly expanded or hits an obstacle, the boundary layer behind it separates, forming a negative pressure area, and when this negative pressure exceeds a certain limit, it overcomes the intermolecular forces of the fluid and creates cavities (voids), from which fine bubbles of microbubbles 14 and ultrafine bubbles of nanobubbles 15 are generated.

[0069] The swirling liquid flow method generates a large negative pressure at the center of a cylindrical container by swirling a high-velocity water flow of paint (either fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint) tangentially around the container at the speed of light, and the gas (one or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) is sucked in and drawn in. The shearing action of the flow causes turbulence, atomizing the gas to generate fine bubbles such as microbubbles 14 and ultrafine bubbles such as nanobubbles 15, which are then mixed into the paint. Due to its structure, the swirling liquid flow method generates even finer bubbles through collapse and shock waves.

[0070] In the shearing method (mechanical shearing method), a gas (one or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) is sucked in by rotating rotors installed in a cylindrical casing, and mixed with paint (any of fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, and water-based paint). As the rotors rotate, the shearing action of the rotors agitates and micronizes the bubbles, generating fine bubbles of microbubbles 14 and ultrafine bubbles of nanobubbles 15. The paint mixed with the microbubbles 14 and nanobubbles 15 is then released toward the mixing outlet. One example is a rotor that rotates, sucking in paint and expelling it through a stator, sucking in gas according to Bernoulli's law, and the action of two types of blades, the fixed blade and the rotating blade, creating turbulence that shears the air bubbles and makes them finer. Another example is a turbo mixer with a vortex turbo pump that automatically sucks in decompressed gas and dissolves it in the paint all at once, performing pressurization and mixing simultaneously and continuously.

[0071] A specific example of a gas introduction device 16 that introduces (mixes) microbubbles 14 and nanobubbles 15 into a coating material 10A using a static mixer system is described below. As shown in FIG. 1 , the gas introduction device 16 includes a coating material storage tank 17 having a predetermined volume, a gas supply tank 18, a water supply pump 19, an air supply pump 20, a static fluid mixer 21 (static mixer), a coating liquid storage tank 22 having a predetermined volume and containing a coating material 10B in which microbubbles 14 and nanobubbles 15 are dispersed and mixed, a cooling device (not shown), and a controller (not shown). Electric power is supplied to the gas introduction device 16 from a power source (not shown). The coating material storage tank 17 contains one of the aforementioned fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, and water-based paint (the coating material 10A before the microbubbles 14 and nanobubbles 15 are dispersed and mixed (dissolved)).

[0072] A level meter (not shown) is installed in the paint storage tank 17. The level meter is connected to the controller via a signal line, measures the level (storage volume) of the paint 10A (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, water-based paint) stored in the paint storage tank 17, and transmits the measured level to the controller. The paint storage tank 17 is connected to the water supply pump 19 via a water supply line 23 (water supply pipe). Although not shown, a flow meter, a check valve, and a water supply solenoid valve are installed in the water supply line 23. The flow meter is connected to the controller via a signal line, measures the flow rate of the paint 10A flowing through the water supply line 23, and transmits the measured flow rate to the controller. The control unit of the water supply solenoid valve is connected to the controller via a signal line, and its on / off (opening and closing) is controlled by the controller.

[0073] The gas supply tank 18 contains a gas to be dispersed and mixed into the paint 10A at a predetermined pressure. The gas to be dispersed and mixed into the paint 10A may be any one of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide, or a mixed gas containing two or more of these. The gas supply tank 18 is connected to a mixing line 25 (mixing pipe) via an air supply line 24 (air supply pipe). The air supply line 24 is equipped with a barometer, a check valve, and an air supply solenoid valve (not shown). The barometer is connected to a controller via a signal line, measures the air pressure of the gas contained in the gas supply tank 18, and transmits the measured air pressure to the controller. The control unit of the air supply solenoid valve is connected to the controller via a signal line, and its on / off (opening and closing) is controlled by the controller. An air supply pump 20 is installed in the air supply pipe 24. The control unit of the air supply pump 20 is connected to the controller via a signal line. The on / off and output of the air supply pump 20 are controlled by the controller.

[0074] The water supply pump 19 is installed in a water supply pipe 23, and its control unit is connected to the controller via a signal line. The start / stop and output of the water supply pump 19 are controlled by the controller. The water supply pump 19 is connected to a static fluid mixer 21 via a mixing pipe 25. The static fluid mixer 21 is connected to a paint tank 22 of a predetermined volume via a supply pipe 26. A level meter (not shown) is installed in the paint tank 22. The level meter is connected to the controller via a signal line, measures the level (storage volume) of the paint 10B in which the microbubbles 14 and nanobubbles 15 are dispersed and mixed and is stored in the paint tank 22, and transmits the measured level to the controller.

[0075] As shown in Fig. 2, the static fluid mixer 21 (static mixer) is formed of a cylindrical unit 27 having an inlet and an outlet, and a plurality of honeycomb structure elements 28 (agitating blades) arranged inside the cylindrical unit 27. The honeycomb structure elements 28 are arranged in a serially connected state inside the cylindrical unit 27. The static fluid mixer 21 passes the paint 10A and gas through the honeycomb structure elements 28 by centrifugal force generated by high-speed rotation, thereby finely pulverizing the gas to the micro-level and ultra-finely pulverizing it to the nano-level to generate microbubbles 14 and nanobubbles 15, and then uniformly mixes (dissolves) the generated microbubbles 14 and nanobubbles 15 into the paint 10A, thereby producing a paint 10B in which the microbubbles 14 and nanobubbles 15 are uniformly dispersed (dissolved) throughout the paint 10A.

[0076] In the static fluid mixing device 21, the paint 10A and the gas pass through the honeycomb structure element 28 many times, thereby causing the gas to become finer (micro-level) and ultra-fine (nano-level) particles, and the finer and ultra-fine gases are mixed (dissolved) into the paint 10A. The cooling device cools the cylindrical unit 27 of the static fluid mixing device 21 to a set temperature by circulating a refrigerant (e.g., hydrofluorocarbon). The control unit of the cooling device is connected to the controller via a signal line. The start / stop and output of the cooling device are controlled by the controller.

[0077] The controller is a physical computer that has a central processing unit (CPU or MPU) and memory (main memory and cache memory), operates under an independent operating system (OS), and is equipped with a large-capacity storage area. Input devices such as a keyboard and a mouse, and output devices such as a display and a printer are connected to the controller via interfaces. The central processing unit of the controller starts a nanobubble mixing application stored in the memory under the control of the operating system (OS), and performs a mixing operation to disperse and mix (disperse and dissolve) microbubbles 14 and nanobubbles 15 into the paint 10A in accordance with the application.

[0078] When the switch of the gas introducing device 16 is turned on, a mixing operation is initiated to mix microbubbles 14 and nanobubbles 15 into the paint 10A (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint) stored in the paint storage tank 17. A predetermined amount of paint 10A is poured into the paint storage tank 17, and the gas supply tank 18 contains gas (one or a mixture of two or more of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide) at a predetermined pressure. When the switch of the gas introducing device 16 is turned ON, the controller sends a water supply signal to the control unit of the water supply pump 19, an air supply signal to the control unit of the air supply pump 20, and a cooling signal to the control unit of the cooling device. Furthermore, the controller sends an open signal to the control unit of the water supply solenoid valve, an open signal to the control unit of the air supply solenoid valve, and sends measurement signals to the level meter, flow meter, and barometer.

[0079] Upon receiving the water supply signal, the control unit of the water supply pump 19 starts the water supply pump 19 at a predetermined output (set output), and upon receiving the air supply signal, the control unit of the air supply pump 20 starts the air supply pump 20 at a predetermined output (set output). Upon receiving the cooling signal, the control unit of the cooling device starts the cooling device at a predetermined output (set output). Upon receiving the open signal, the control unit of the water supply solenoid valve opens the water supply solenoid valve, and upon receiving the open signal, the control unit of the air supply solenoid valve opens the air supply solenoid valve. Upon receiving the measurement signal, the level meter begins measuring the level of the paint 10A stored in the paint storage tank 17, and upon receiving the measurement signal, the flow meter begins measuring the flow rate of the paint 10A flowing through the water supply pipe 23. Upon receiving the measurement signal, the barometer begins measuring the air pressure of the gas flowing through the air supply pipe 24.

[0080] Paint 10A stored in paint storage tank 17 is forcibly supplied from paint storage tank 17 to static fluid mixer 21 by starting water supply pump 19 (paint water supply process). Paint 10A flows from water supply pipe 23 through water supply pump 19 into mixing pipe 25, and then flows through mixing pipe 25 into static fluid mixer 21. Gas stored in gas supply tank 18 is forcibly supplied from gas supply tank 18 to static fluid mixer 21 by starting air supply pump 20 (gas supply process). The gas flows from air supply pipe 24 through air supply pump 20 into mixing pipe 25, is mixed with paint 10A in mixing pipe 25, and then flows into static fluid mixer 21 together with paint 10A. In the mixing pipeline 25, the paint 10A supplied by the water supply pump 19 is mixed with the gas supplied by the air supply pump 20 to produce a gas-mixed paint (mixing process). The gas-mixed paint flows into the static fluid mixer 21.

[0081] The controller receives the measured level measured by the level meter of the paint storage tank 17 and outputs (displays) a water injection message on the display when the measured level drops to the water injection level. The water injection message allows the user to know the amount of paint 10A being injected into the paint storage tank 17. The controller receives the measured flow rate measured by the flow meter and adjusts the output of the water supply pump 19 so that the measured flow rate becomes the target flow rate. The controller receives the measured air pressure measured by the barometer and adjusts the output of the air supply pump 20 so that the measured air pressure becomes the target air pressure.

[0082] The cooling device continuously cools the cylindrical unit 27 of the static fluid mixer 21 using a refrigerant while the gas introduction device 16 is operating (cooling process). The cooling device maintains the temperature of the cylindrical unit 27 at a set temperature (e.g., 10 to 20°C). In the static fluid mixer 21, the paint 10A mixed with gas flows in through an inlet, and the mixed paint 10A is transformed into a continuous phase fluid and a dispersed phase fluid by a plurality of honeycomb structure elements 28 (agitating blades), and the continuous phase and dispersed phase fluids of the mixed paint 10A flow in a serpentine manner through the honeycomb structure elements 28. The shear force applied at this time atomizes the dispersed phase fluid (gas), generating an atomized mixed fluid.

[0083] Next, after the flow of the generated atomized mixed fluid is rectified, the rectified atomized mixed fluid flows while meandering through the honeycomb structure element 28 arranged on the downstream side, and the atomized mixed fluid (gas) as a dispersed phase is further atomized by the shear force it receives at that time. Finally, the gas mixed in the paint 10A is atomized to the micro-level or nano-level, and the micro-level or nano-level bubbles (microbubbles 14 and / or nanobubbles 15) are dispersed and mixed (dispersed and dissolved) in the paint 10B, and particles having an average particle diameter D ５０ is 100 μm or less, preferably, the average particle size D ５０ is 0.5 μm or less, more preferably the average particle size D ５０ The microbubbles 14 are independent fine bubbles having an average particle diameter D of 0.2 μm or less. ５０A coating material 10B is produced in which nanobubbles 15, which are independent ultrafine bubbles having a size in the range of 1 to 800 nm, preferably in the range of 1 to 300 nm, are dispersed and mixed (dispersed and dissolved) at a predetermined concentration (microbubble and / or nanobubble-containing coating material manufacturing process).

[0084] When the microbubbles 14 and nanobubbles 15 are introduced (mixed) into the paint 10A, friction between the paint 10A and the microbubbles 14 and nanobubbles 15 causes the temperature of the paint 10B in the cylindrical unit 27 in which the microbubbles 14 and / or nanobubbles 15 are dispersed and mixed rises. However, the cooling device cools the cylindrical unit 27, thereby maintaining the temperature of the paint 10B in the cylindrical unit 27 at 10 to 20°C. The paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed and mixed (dispersed and dissolved) is stored in the paint storage tank 22 through the supply pipe 26. The controller receives a measurement level measured by a level meter in the paint storage tank 22 and outputs (displays) the measurement level on a display. The measurement level output on the display allows the amount of the paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed and mixed to be known.

[0085] The paint manufacturing method can reliably introduce microbubbles 14 and / or nanobubbles 15 into the paint 10A by using these methods (pressure dissolution method, micropore and porous method, ejector method, Venturi method, ultrasonic method, static mixer method, cavitation method, swirling liquid flow method, shear method), and can produce a paint 10B that can be applied in a reduced amount to the surface 12 of the substrate 11 and can also produce a paint 10B that can be applied inexpensively. The paint manufacturing method can produce a paint 10B that can have a low viscosity and can improve the ease of application to the surface 12 of the substrate 11.

[0086] The paint 10B in which a large amount of microbubbles 14 and / or nanobubbles 15 are dispersed and mixed (dispersed and dissolved) by the air bubble introduction method or the gas introduction device 16 of FIGS. 1 and 2 reacts with hydrogen ions H ＋ Concentration and hydroxide ion OH －The acid-base properties of the paint 10B are approximately neutral or alkaline, with concentrations being approximately equal. The microbubbles 14 and nanobubbles 15 dispersed and mixed inside the paint 10B are in the form of spheres with high internal bubble pressure and are negatively charged.

[0087] The paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed (dispersed and dissolved) can reduce the proportion of the paint 10B itself per unit volume of the paint 10B (the paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed (dispersed and dissolved)), and when the paint 10B (the paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed (dispersed and dissolved)) is applied to the surface 12 of the substrate 11 to be coated, the amount of the paint 10B itself to be coated is reduced, making it possible to reduce the amount of the paint 10B to be coated on the substrate 11. Furthermore, compared to when the microbubbles 14 and / or nanobubbles 15 are not dispersed and mixed in the paint 10B, the reduced amount of coating reduces the unit price of the paint 10B per unit area of ​​the surface 12 of the substrate 11, and the paint 10B can be applied (used) inexpensively. The paint 10B has a reduced mass per unit volume compared to when the microbubbles 14 or nanobubbles 15 are not dispersed and mixed (dispersed and dissolved) in the paint 10B, and therefore when the paint 10B is applied to the surface 12 of the substrate 11 to be coated, the increase in weight of the substrate 11 including the coating film 13 formed from the paint 10B can be minimized.

[0088] The viscosity of the paint 10B containing the dispersed microbubbles 14 is in the range of 1 to 1,000 mPa·s, preferably 1 to 100 mPa·s. By dispersing the microbubbles 14 into the paint 10A before the dispersion of the microbubbles 14, the viscosity of the paint 10A before the dispersion of the microbubbles 14 can be reduced to one-third to one-half. For example, by dispersing the microbubbles 14 into a high-viscosity paint 10A with a viscosity of 180 mPa·s, the viscosity can be reduced to 60 to 90 mPa·s, and by dispersing the microbubbles 14 into a medium-viscosity paint 10A with a viscosity of 60 mPa·s, the viscosity can be reduced to 20 to 30 mPa·s. The viscosity of the paint 10B can be reduced by introducing (mixing) microbubbles 14 into it, and the high-viscosity or medium-viscosity paint 10A can be converted into the low-viscosity paint 10B by reducing or eliminating the amount of substances that may have adverse effects on the human body.

[0089] The paint 10B has an average particle size D of the microbubbles 14. ５０ By adjusting the content of microbubbles 14 in the paint 10B, the viscosity of the paint 10B can be adjusted and the ease of application of the paint 10B to the surface 12 of the substrate 11 can be improved. By using microbubbles 14 to adjust the viscosity of the paint 10B, particularly in low-temperature environments where the viscosity of the paint 10B is high and where a larger amount of thinner or the like is used to adjust the viscosity, the use of paint 10B containing microbubbles 14 that dissolve in large amounts in low-temperature environments makes it possible to provide a paint 10B that significantly reduces or eliminates the use of substances that may be harmful to the human body. The viscosity of the paint 10B varies depending on the type of gas that forms the microbubbles 14, and selecting the gas used allows for fine adjustment of the paint viscosity. When the paint 10B is a water-based paint, the amount of water used to adjust the viscosity can be reduced or no water is required, making the paint 10B useful in areas with water shortages or in environments where water is unavailable.

[0090] The microbubbles 14 inside the paint 10B have an average particle size D ５０The microbubbles 14 per ml of the paint 10B in which the microbubbles 14 are dispersed and mixed are 10 ５ pcs / ml or more 10 １２ 10 ５ ~10 １２ (cells / ml range).

[0091] Since the number of microbubbles 14 per ml of paint 10B in which the microbubbles 14 are dispersed and mixed falls within the above range, a large amount of the microbubbles 14, which are fine air bubbles, are dispersed and mixed (dispersed and dissolved) in the paint 10B at a predetermined concentration, and the proportion of the paint 10B itself per unit area in the paint 10B can be reduced by the microbubbles 14, which are fine air bubbles, and the amount of paint 10B itself to be applied when the paint 10B is applied to the surface 12 of the substrate 11 to be applied can be reliably reduced. ５ ~10 １２ By containing microbubbles 14 in the range of pieces / ml, the amount of coating material 10B to be applied to the substrate 11 is reduced, so that the unit cost of the coating material 10B per unit area of ​​the surface 12 of the substrate 11 can be reduced, and the coating material 10B can be applied inexpensively.

[0092] The particle size of the microbubbles 14 dispersed within the paint 10B was measured using visualization, light scattering, laser diffraction / scattering, and interference imaging. The content and total number of microbubbles 14 dispersed within the paint 10B were measured using the electrical detection zone method and image analysis. The visualization method involves photographing the microbubbles 14 using an imaging device such as a digital microscope or CCD camera, converting the image into black and white using image processing, and measuring the particle size (bubble diameter). The light scattering method uses a laser particle size distribution analyzer to irradiate the paint containing the microbubbles 14 with a beam of laser light, detect the scattered light with a photomultiplier tube, and measure the particle size (bubble diameter) based on Mie scattering theory. The laser diffraction / scattering method involves irradiating laser light onto the microbubbles, instantaneously scattering diffracted / scattered light forward, backward, and sideways, and correlating the scattered light pattern with the bubble diameter to measure the particle size (bubble diameter). In the interference imaging method, when a spherical bubble is irradiated with laser light, a scattering pattern is obtained, but interference fringes are observed on the out-of-focus surface. The particle size (bubble diameter) is calculated from the number of interference fringes using a CCD camera.

[0093] In the paint 10B containing dispersed microbubbles 14, the rising speed of the microbubbles 14 inside the paint 10B at room temperature is in the range of 0.00005 mm / min to 0.0005 mm / min (0.0005 to 0.00005 mm / min). Because the microbubbles 14 have a small volume, their rising speed inside the paint 10B is very slow. If the rising speed of the microbubbles 14 inside the paint 10B exceeds 0.0005 mm / min, it becomes difficult to retain the microbubbles 14 in the paint 10B for a long period of time, and the microbubbles 14 may volatilize from the paint 10B within the target residence time. Since the rate at which the microbubbles 14 rise inside the paint 10B at room temperature is within the above range, the microbubbles 14 are less likely to volatilize from the paint 10B and can remain in the paint 10B for a long period of time, thereby reliably reducing the amount of paint 10B to be applied when the paint 10B is applied to the substrate 11 to be coated.

[0094] The nanobubbles 15 dispersed (dissolved) within the paint 10B undergo Brownian motion within the paint 10B at room temperature where the paint 10B is stored. The viscosity of the paint 10B with the nanobubbles 15 dispersed therein is in the range of 1 to 1,000 mPa·s, preferably in the range of 1 to 100 mPa·s. By dispersing the nanobubbles 15 into the paint 10A before the nanobubbles 15 are dispersed, the viscosity of the paint 10A before the nanobubbles 15 are dispersed can be reduced to one-quarter to one-half. For example, by dispersing the nanobubbles 15 into a high-viscosity paint 10A with a viscosity of 180 mPa·s, the viscosity can be reduced to 45 to 90 mPa·s, and by dispersing the nanobubbles 15 into a medium-viscosity paint 10A with a viscosity of 60 mPa·s, the viscosity can be reduced to 15 to 30 mPa·s. The viscosity of the paint 10B can be reduced by introducing (mixing) nanobubbles 15 into it, and the high-viscosity or medium-viscosity paint 10A can be converted into the low-viscosity paint 10B by reducing or eliminating the amount of substances that may have adverse effects on the human body.

[0095] The viscosity of the paint 10B is reduced by the nanobubbles 15 undergoing Brownian motion inside the paint 10B, and the nanobubbles 15 dissolve, cutting the bonds between molecules and weakening the interactions between molecules. This reduces the viscosity of the paint 10B, and the average particle size D of the nanobubbles 15 ５０By adjusting the content of nanobubbles 15 in the paint 10B, the viscosity of the paint 10B can be adjusted and the ease of application of the paint 10B to the surface 12 of the substrate 11 can be improved. By using nanobubbles 15 to adjust the viscosity of the paint 10B, particularly in low-temperature environments where the viscosity of the paint 10B is high and where a larger amount of thinner or the like is used to adjust the viscosity, the use of paint 10B containing nanobubbles 15 that dissolve in large amounts in low-temperature environments makes it possible to provide a paint 10B that significantly reduces or eliminates the use of substances that may be harmful to the human body. The viscosity of the paint 10B varies depending on the type of gas that forms the nanobubbles 15, and selecting the gas to be used allows for fine adjustment of the paint viscosity. When the paint 10B is an aqueous paint, the viscosity can be adjusted by using nanobubbles 15, reducing the amount of water used for viscosity adjustment or eliminating the need for water for viscosity adjustment, making the paint 10B useful in areas with water shortages or environments where water is unavailable.

[0096] The nanobubbles 15 inside the paint 10B have an average particle size D ５０ The nanobubbles 15 per ml of the coating material 10B in which the nanobubbles 15 are dispersed and mixed are 0.5 μm or less, preferably 1 nm or more and 800 nm or less, and more preferably 1 nm or more and 300 nm or less. ５ pcs / ml or more 10 １２ 10 ５ ~10 １２ ml range).

[0097] Since the content of nanobubbles 15 in paint 10B in which nanobubbles 15 are dispersed and mixed falls within the above range, a large amount of ultrafine nanobubbles 15 are dispersed and mixed (dispersed and dissolved) at a predetermined concentration inside paint 10B, and the proportion of paint 10B itself per unit area in paint 10B can be reduced by the ultrafine nanobubbles 15, and the amount of paint 10B itself to be applied when paint 10B is applied to surface 12 of substrate 11 to be applied can be reliably reduced. ５ ~10 １２By including nanobubbles 15 in the range of nanobubbles 15 / ml, the amount of coating material 10B to be applied to the substrate 11 is reduced, so that the unit cost of coating material 10B per unit area of ​​the surface 12 of the substrate 11 can be reduced, and coating material 10B can be applied inexpensively.

[0098] The particle size, content, and total number of nanobubbles 15 dispersed within the paint 10B were measured using nanoparticle tracking analysis (NTA). Nanoparticle tracking analysis can measure the particle size (particle size distribution), content, total number (particle number concentration), and aggregation state of nanobubbles 15 in the paint 10B with high resolution. In nanoparticle tracking analysis, the paint 10B containing dispersed nanobubbles 15 is placed in a sample chamber, and a laser beam is irradiated onto the sample chamber. In nanoparticle tracking analysis, a highly sensitive CMOS camera detects the 90° scattered light from each nanobubble 15 irradiated with the laser beam. The Brownian motion of the detected particles is observed and tracked as the movement of bright spots on the camera image. By tracking this movement, the diffusion coefficient is calculated, and the particle size of the nanobubbles 15 is determined using the Stokes-Einstein equation. The particle distribution (concentration) is determined by counting all particles within the field of view of the camera, whose volume is known, to determine the number of nanobubbles 15 per ml, and then calculating the nanobubble 15 content in paint 10B and the total number of nanobubbles 15 per ml of paint 10B. If nano-sized ultrafine particles are present in paint 10B, the total number of nanobubbles 15 can be counted by comparing the results with those for paint 10A. In nanoparticle tracking analysis, the zeta potential of particles is determined by measuring the electrophoretic mobility when a constant voltage is applied to a cell. The volume of nanobubbles 15 dispersed within paint 10B can also be measured by laser diffraction / scattering, and the number of nanobubbles 15 dispersed within paint 10B can also be measured by electrical detection zone analysis or image analysis.

[0099] In the paint 10B having the nanobubbles 15 dispersed therein, the rising speed of the nanobubbles 15 at room temperature is in the range of 0.000005 mm / min to 0.00005 mm / min (0.00005 to 0.000005 mm / min). Because the volume of the nanobubbles 15 is extremely small, the rising speed of the nanobubbles 15 inside the paint 10B is extremely slow. If the rising speed of the nanobubbles 15 inside the paint 10B exceeds 0.00005 mm / min, it becomes difficult to retain the nanobubbles 15 in the paint 10B for a long period of time, and the nanobubbles 15 may volatilize from the paint 10B within the target residence time. In paint 10B, the rate at which nanobubbles 15 rise inside paint 10B at room temperature is within the above range, so nanobubbles 15 are less likely to volatilize from paint 10B, and nanobubbles 15 can be retained in paint 10B for a long period of time, thereby reliably reducing the amount of paint 10B to be applied when paint 10B is applied to substrate 11 as a coating target.

[0100] The rising speed of the nanobubbles 15 in the paint 10B is extremely slow. The rising speed in the paint 10B depends on the liquid properties of the paint 10B. In water, the nanobubbles have a diameter of about 1 μm, and the Reynolds number Re is approximately 1, forming spherical bubbles. The rising speed U of a spherical bubble with a diameter d is given by the Stokes equation: U=pgd ２ / 18μ, where p is the liquid density, g is the gravitational acceleration, and μ is the liquid viscosity.

[0101] The nanobubbles 15 mixed (dissolved) inside the paint 10B have high internal bubble pressure (self-pressurizing effect). The internal bubble pressure is higher than the pressure around the bubbles by ΔP according to the Young-Laplace equation: ΔP = 4σ / d, due to the influence of surface tension σ. The relationship between the diameter d of a bubble in the paint 10B and the internal bubble pressure is such that the smaller the bubble, the higher the internal bubble pressure (3.87 "atm" for 1 μm, 29.7 "atm" for 100 nm, the surface tension σ of water: 72.8 mN / m (20°C), and the pressure around the bubble is 1 "atm"). Therefore, when the bubbles shrink, the partial pressure of the dissolved gas components, i.e., the driving force for dissolution, increases. Reducing the gas to nano-size facilitates dissolution of the gas in the paint 10B, and a large amount of nanobubbles 15 dissolves in the paint 10B.

[0102] The nanobubbles 15 mixed (dissolved) inside the paint 10B have a large gas-liquid interfacial area. The gas-liquid interfacial area per unit volume, A / V, is expressed by the formula: A / V = 6d. A / V increases as the bubble diameter d decreases, and contributes greatly to the amount of gas mixed (dissolved) in the paint 10B. The amount of mixed (dissolved) gas in the nanobubbles 15 is extremely large. The mass transfer rate N (mol / s) of the bubbles into the paint 10B is expressed by the formula: N = K Ｇ A(pp*), where K Ｇ is the gas phase reference overall mass transfer coefficient "mol / m ２ sPa”, A is the surface area of ​​the bubble [m ２ ], p is the partial pressure of the dissolved component in the bubble (Pa), and p* is the partial pressure of the gas phase (Pa) in equilibrium with the dissolved component in the liquid phase.

[0103] When the nanobubbles 15 are dissolved (mixed) into the paint 10B, the overall mass transfer resistance 1 / K is calculated based on the double boundary film theory consisting of a gas boundary film and a liquid boundary film sandwiching the gas-liquid interface. Ｌ or 1 / K Ｇ H is the liquid phase resistance 1 / k Ｌ and gas phase resistance 1 / k Ｇ As a sum of H, Ohm's law of electrical resistance is given by the formula: 1 / K Ｌ = 1 / K Ｇ H=1 / k Ｌ +1 / k Ｇ H. Here, K Ｌ is the liquid phase reference overall mass transfer coefficient, H is Henry's constant (p = H Ｃ ), formula: 1 / K Ｌ = 1 / K Ｇ H=1 / k Ｌ +1 / k Ｇ Gas side mass transfer resistance 1 / K at H Ｇ If H can be almost ignored, the liquid phase reference overall mass transfer coefficient K Ｌ and the liquid side mass transfer coefficient K Ｌ and are approximately equal.

[0104] For spherical bubbles, the Reynolds number Re<1 and the rising speed is the Stokes equation: U=pgd ２ / 18μ when the liquid side mass transfer coefficient k Ｌ is the formula: k Ｌ =DＬ / d[l+(1+dU / D Ｌ ) １／３ ] where D Ｌ is the diffusion coefficient of the gas in the liquid phase, d is the bubble diameter, and U is the rising speed of the bubble. For example, Ｌ =D Ｌ +dl+[(1+dU / D Ｌ ) １／３ ] is the bubble diameter and the liquid-side mass transfer coefficient k of the oxygen-water system. Ｌ When the bubble diameter d is 100 μm, k Ｌ is 1.817.10 －４ "m / s", k when the bubble diameter d is 10 μm Ｌ is 5.37.10 －４ "m / s", k when the bubble diameter d is 1 μm Ｌ is 5.20.10 －３ The diffusion coefficient D of oxygen inside the paint 10 is Ｌ is 2.60 / 10 －９ "m ２ / s" was used.

[0105] k relative to the bubble diameter d Ｌ Using the value of N = K and the bubble internal pressure "atm" for the bubble diameter d, Ｇ The mass transfer rate N was calculated using A(pp*) and rearranged. As a result, when the bubble diameter d was 10 μm, the rising rate U was 3.26 × 10 －３ "m / min", pressure difference ΔP is 2.91·10 ４ , the bubble number ratio is 1.0.10 ６ , area ratio is 100, mass transfer rate ratio is 6.15·10 ４ "mol / s" and 1.0 / 10 ８ When the bubble diameter d is 100 nm, the rising speed U is 3.15.10 －７ "m / min", pressure difference ΔP is 2.91·10 ６ , the bubble number ratio is 1.0.10 １２ , area ratio is 1.0.10 ４ , mass transfer rate ratio is 5.95·10 １０ "mol / s" and 1.0 / 10 １８ "mol / mm".

[0106] When a spherical bubble with a diameter of 1 mm is divided into bubbles with a diameter of 10 μm, the number of bubbles is 10 ６ If a spherical bubble with a diameter of 1 mm is divided into bubbles with a diameter of 100 nm, the number of bubbles will increase to 10. １２ The number of bubbles increases, and if the surface area of ​​a bubble with a diameter of 1 mm is taken as 1, the surface area becomes 10 ４ Therefore, if the mass transfer rate (dissolution rate) per unit time of a bubble with a diameter of 1 mm is 1, then the mass transfer rate (dissolution rate) of a bubble with a diameter of 10 μm is 6.10 ４ When the mass transfer rate (dissolution rate) per unit time of a bubble with a diameter of 1 mm is set to 1, the mass transfer rate (dissolution rate) of a bubble with a diameter of 100 nm is 6.10 times that of a bubble with a diameter of 100 nm. １０ In this way, when the bubbles become nano-sized, the surface area and the partial pressure inside the bubbles increase, and the rate of rise decreases, so that the mass transfer rate (dissolution rate) for the paint 10B increases rapidly.

[0107] The surface potential of the nanobubbles 15 was measured using an electrophoresis experimental device. The nanobubbles 15 generated in the container were subjected to zigzag motion by switching the electric field direction of the electrodes introduced into the electrophoresis cell (thickness 1 mm, height 23.0 mm, width 75.0 mm) every 1 second. The bubble diameter was calculated using the Stokes equation by measuring the rising speed, and the zeta potential of the bubbles was calculated using the Smoluchowski equation: ζ = μu / ε by measuring the horizontal speed. Here, ζ is the zeta potential "V", μ is the viscosity of the paint 10B "kg / ms", and u is the mobility of the bubbles "m ２ / sV”, ε is the dielectric constant of the paint 10B “s ２ C ２ / kgm ３ "

[0108] Regardless of the bubble diameter, the nanobubbles 15 are negatively charged at -30 to -40 mV (the same is true for the microbubbles 14). The cluster structure of the paint 10B is formed from the paint 10B molecules and ionized positive and negative ions, and while positive and negative ions tend to fit within this structure, negative ions in particular tend to accumulate at interfaces, resulting in a negative charge. Because the nanobubbles 15 are negatively charged, the nanobubbles 15 in the paint 10B repel each other, the microbubbles 15, and the nanobubbles 14 and the microbubbles 15, and the electrostatic repulsion makes it less likely that the nanobubbles 15 will bond (coalesce) with each other, the microbubbles 15, or the nanobubbles 14 and the microbubbles 15.

[0109] Since the nanobubbles 15 (microbubbles 15) mixed (dissolved) in the paint 10B are negatively charged, the nanobubbles 14 dispersed and mixed in the paint 10B repel each other, the microbubbles 15 repel each other, and the nanobubbles 14 and ... In the paint 10B, the microbubbles 14, the nanobubbles 15, and the nanobubbles 14 and the microbubbles 15 do not bond (unite) with each other, or with each other, or with each other, but the microbubbles 14 and the ultrafine nanobubbles 15 are dispersed and mixed (dispersed and dissolved) in the paint 10B. This makes it difficult for the nanobubbles 15 and the microbubbles 14 to volatilize from the paint 10B, and the nanobubbles 15 and the microbubbles 14 can remain in the paint 10B for a long period of time.

[0110] In the paint 10B, the nanobubbles 15 are not bonded in a columnar shape, but are dispersed (dissolved) in a large amount in the form of spheres with high internal bubble pressure at a predetermined concentration inside the paint 10B. ５０The nanobubbles 15 having a size of 0.5 μm or less, preferably 1 nm or more and 800 nm or less, more preferably 1 nm or more and 300 nm or less are dispersed and mixed in the paint 10B in a large amount at a predetermined concentration (high concentration), and the number of nanobubbles 15 per ml of the paint 10B is 10 ５ pcs / ml or more 10 １２ Since the concentration is in the range of nanobubbles 15 or less per unit volume, the nanobubbles 15, which are ultrafine bubbles, can reduce the proportion of the paint 10B itself per unit volume in the paint 10B (the paint 10B having the nanobubbles 15 mixed (dissolved) in it), and this can reliably reduce the amount of paint 10B itself to be applied when the paint 10B (the paint 10B having the nanobubbles 15 mixed (dissolved) in it) is applied to the surface 12 of the substrate 11 to be applied.

[0111] The paint 10B has a large amount of microbubbles 14 dispersed (dispersed and dissolved) in a spherical state with a high internal bubble pressure at a predetermined concentration inside the paint 10B, and the average particle diameter D ５０ A large amount of microbubbles 14 having a size of 100 μm or less are dispersed and mixed in the paint 10B at a predetermined concentration (high concentration), and the number of microbubbles 14 per 1 ml of the paint 10B is 10 ５ pcs / ml or more 10 １２ Since the concentration is in the range of not more than 15 / ml, the microbubbles 14, which are fine bubbles, can reduce the proportion of the paint 10B itself per unit volume in the paint 10B (paint 10B having microbubbles 14 mixed (dissolved) in it), and this can reliably reduce the amount of paint 10B itself to be applied when the paint 10B (paint 10B having microbubbles 15 mixed (dissolved) in it) is applied to the surface 12 of the substrate 11 to be applied.

[0112] The forces acting on the nanobubbles 15 inside the paint 10B include buoyancy and drag. Buoyancy is proportional to the volume of the nanobubbles 15 (proportional to the cube of the radius of the nanobubbles 15). Drag is proportional to the cross-sectional area of ​​the nanobubbles 15 (proportional to the square of the radius of the nanobubbles 15) and proportional to the square of the rising speed of the nanobubbles 15. Specifically, when the radius of the nanobubbles 15 is r, the density of the paint 10B is ρ, the gravitational acceleration is g, the viscosity of the paint 10B is η, and the moving speed of the nanobubbles 15 is u, the buoyancy acting on the nanobubbles 15 (ignoring the density of the nanobubbles 15) is expressed by Archimedes' principle as follows: F = 4πr 3 It is expressed by ρg / 3.

[0113] Furthermore, the resistance force acting on the nanobubbles 15 is expressed by the formula (2): F = 6πηru according to Stokes' theorem. From the formulas (1) and (2), the moving speed u of the nanobubbles 15 inside the paint 10B is expressed by the formula (3): u = (2 / 9)r 2 The ascending velocity of the nanobubbles 15 in the paint 10B was calculated using formula (3). As is clear from formula (3), the larger the radius r (particle size) of the nanobubbles 15, the higher the moving velocity u of the nanobubbles 15 in the paint 10B.

[0114] When the radius r of the nanobubble 15 under 1 atmosphere is a, the radius r and the water depth h are calculated by the following formula (4): r = a × {101325 / (ρgh + 101325)} 1 / 3 As is clear from the formulas (3) and (4), the particle size of the nanobubbles 15 increases as the water depth of the paint 10B decreases, and the rising speed increases.

[0115] It is hypothesized that nanobubbles 15 with a diameter of less than 1.0 μm will have their solubility reduced by the salting-out phenomenon, and will remain stable for a long period of time inside the paint 10B. If the nanobubbles 15 continue to exist stably for a long period of time due to the salting-out phenomenon, there will be no paint 10B containing nanobubbles 15 with a pH close to 7. However, there are cases where stable nanobubbles 15 exist even in a neutral liquid.

[0116] When nanobubbles 15 and larger microbubbles 14 are mixed in the paint 10B, the nanobubbles 15 may rise to the surface due to the influence of the latter larger microbubbles 14, or may be affected by cavitation destruction due to external pressure, which may shorten the lifespan of the nanobubbles 15.

[0117] A building is an example of a substrate 11 (object) to which the paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied. The paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied to the surface (front and back) of the building, and the hardened paint 10B forms a coating film 13 containing dispersed microbubbles 14 and / or nanobubbles 15 on the surface (front and back) of the building.

[0118] Structures include buildings and certain associated structures, as well as man-made structures other than buildings. Buildings include structures for viewing, offices, stores, entertainment venues, warehouses, and other similar facilities located within underground or elevated structures, building equipment, civil engineering structures such as bridges and water gates, and construction materials (mortar, concrete, ALC, siding boards, extruded cement boards, gypsum boards, slate, wood, PC boards, etc.). Structures include chimneys, towers, elevated water tanks, and similar structures, bridges, elevated roads, elevated railways, and similar structures, manufacturing facilities, storage facilities, water and electricity supply facilities, waste disposal facilities, and similar structures, sports facilities such as baseball fields and tennis courts, recreational facilities such as amusement parks, and similar structures.

[0119] A structure coated with the paint 10B incorporating microbubbles 14 and / or nanobubbles 15 has a reduced amount of paint 10B itself applied when the paint 10B containing the closed-cell microbubbles 14 and / or nanobubbles 15 dispersed (dissolved) at a predetermined concentration is applied to the surface of the structure, and this reduced amount of paint 10B reduces the unit price of the paint 10B per unit area of ​​the surface of the structure, allowing the paint 10B to be applied inexpensively to the surface of the structure and reducing the construction cost of the structure. The dispersed (dissolved) microbubbles 14 and / or nanobubbles 15 in the paint 10B applied to the surface of the structure reduces the viscosity of the paint 10B, making it easier to apply the paint 10B to the surface of the structure and shortening the application time for the paint 10B to the surface of the structure. The mass of the paint 10B per unit volume of the structure is reduced compared to when the microbubbles 14 and nanobubbles 15 are not dispersed and mixed (dispersed and dissolved) in the paint 10B, and therefore, when the paint 10B is applied to the surface of the structure, the increase in the weight of the structure including the coating film 13 formed from the paint 10B can be minimized.

[0120] A moving body is another example of a substrate 11 (object) to which the paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied. The paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied to the surface (front and back) of the moving body, and the hardened paint 10B forms a coating film 13 containing dispersed microbubbles 14 and / or nanobubbles 15 on the surface (front and back) of the moving body.

[0121] Mobile objects include automobiles, motorcycles, mopeds, bicycles, trains, flying objects, and ships. Automobiles include all automobiles, including standard automobiles, compact automobiles, light automobiles, large special-purpose automobiles, and small special-purpose automobiles, and include automobiles of all body types (SUVs, light automobiles, minivans, minivans, sedans, station wagons, etc.), all engines and power sources (gasoline-powered automobiles, diesel-powered automobiles, hybrid automobiles, EVs, fuel cell automobiles), and all drive systems (2WD, 4WD). Note that automobiles include all automobiles developed in the future. Paint 10B is applied to the exterior (surfaces), interior (surfaces), and parts (surfaces) of automobiles.

[0122] Motorcycles include standard motorcycles and large motorcycles. Motorcycles include all motorcycles developed in the future. Bicycles include city bicycles, folding bicycles, electric assist bicycles, mini velos, mountain bikes, road bikes, cross bikes, fixed gear bikes, cyclocross bikes, BMX, kick bikes, and bicycles with training wheels. Bicycles include all bicycles developed in the future. Paint 10B is applied to the exterior (surfaces) and parts (surfaces) of motorcycles and bicycles.

[0123] Electric trains include bullet trains, superconducting linear trains, special-type electric trains, general-type electric trains, express diesel railcars, general-type diesel railcars, passenger cars, electric locomotives, and diesel locomotives. Electric trains include all trains that will be developed in the future. Paint 10B is applied to the exterior (surfaces), interior (surfaces), and parts (surfaces) of electric trains. Flying objects include aircraft (single-engine passenger aircraft, reciprocating passenger aircraft, large propeller passenger aircraft, large jet passenger aircraft, civilian cargo aircraft, fighter / attack aircraft), drones, balloons, sounding rockets, artificial satellites, and the like. Flying objects include all trains that will be developed in the future. Paint 10B is applied to the exterior (surfaces), interior (surfaces), and parts (surfaces) of flying objects.

[0124] A movable body coated with the paint 10B containing the microbubbles 14 and / or nanobubbles 15 dispersed (dissolved) at a predetermined concentration requires a reduced amount of paint 10B when the paint 10B is applied to the surface of the movable body. This reduced amount reduces the cost of the paint 10B per unit area of ​​the movable body's surface, allowing the paint 10B to be applied inexpensively to the surface of the movable body and reducing the manufacturing cost of the movable body. The dispersed (dissolved) microbubbles 14 and / or nanobubbles 15 in the paint 10B to be applied to the surface of the movable body reduces the viscosity of the paint 10B, making it easier to apply the paint 10B to the surface of the movable body and shortening the application time for the paint 10B to the surface of the movable body. The mass of the paint 10B per unit volume of the moving body is reduced compared to when the microbubbles 14 and nanobubbles 15 are not dispersed and mixed (dispersed and dissolved) in the paint 10B, and therefore, when the paint 10B is applied to the surface of the moving body, the increase in the weight of the moving body including the coating film 13 formed from the paint 10B can be minimized.

[0125] Another example of a substrate 11 (object) to which the paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied is an industrial product. The paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied to the surface (front and back) of the industrial product, and the cured paint 10B forms a coating film 13 containing dispersed microbubbles 14 and / or nanobubbles 15 on the surface (front and back) of the industrial product. Industrial products are items manufactured using raw materials in industries such as the metal industry, chemical industry, and machinery industry. Industrial products include factory machinery and equipment, cutting tools, machine tools, pipelines, smartphones, televisions, displays, computers, cameras, electrical wiring, and the like. Industrial products include all products developed in the future.

[0126] When an industrial product is coated with the paint 10B into which microbubbles 14 and / or nanobubbles 15 have been introduced (mixed), the amount of paint 10B itself applied is reduced when the paint 10B containing the closed-cell microbubbles 14 and / or nanobubbles 15 dispersed (dissolved) at a predetermined concentration is applied to the surface of the industrial product, and this reduced amount of paint applied can reduce the unit price of the paint 10B per unit area of ​​the industrial product surface, allowing the paint 10B to be applied inexpensively to the surface of the industrial product and reducing the manufacturing cost of the industrial product. The dispersed (dissolved) microbubbles 14 and / or nanobubbles 15 in the paint 10B applied to the surface of the industrial product reduce the viscosity of the paint 10B, making it easier to apply the paint 10B to the surface of the industrial product and shortening the application time for the paint 10B to the surface of the industrial product. In the industrial product, the mass of the paint 10B per unit volume is reduced compared to when the microbubbles 14 and nanobubbles 15 are not dispersed and mixed (dispersed and dissolved) in the paint 10B, and therefore, when the paint 10B is applied to the surface of the industrial product, the increase in the weight of the industrial product including the coating film 13 formed from the paint 10B can be minimized.

[0127] Furniture and fixtures are another example of the substrate 11 (object) to which the paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied. The paint 10B containing dispersed microbubbles 14 and / or nanobubbles 15 is applied to the surface (front and back) of the furniture or fixture, and the hardened paint 10B forms a coating film 13 containing dispersed microbubbles 14 and / or nanobubbles 15 on the surface (front and back) of the furniture or fixture.

[0128] Furniture and equipment include Japanese furniture, sashimono (wooden sashimi), chests of drawers, dressing tables, Japanese desks, low tables, low desks, water closets, fly screens, bamboo furniture, rattan furniture, porcelain furniture, veneer boards, spatula stands, ironing boards, Western furniture, tables, chairs, reception sets, marine furniture, school furniture, beds, radio / TV / stereo cabinets, sewing machine tables, cupboards, bookshelves, hospital furniture, medicine cabinets, metal furniture, metal cabinets, metal lockers, metal chairs, metal beds, metal tables, metal storage cabinets and cupboards, etc. Furniture and equipment includes all items developed in the future.

[0129] When the paint 10B containing the microbubbles 14 and / or nanobubbles 15 is applied to furniture or fixtures, the amount of paint 10B itself applied is reduced when the paint 10B containing the closed-cell microbubbles 14 and / or nanobubbles 15 dispersed (dissolved) at a predetermined concentration is applied to the surface of the furniture or fixture. This reduction in the amount applied reduces the unit price of the paint 10B per unit area of ​​the surface of the furniture or fixture, allowing the paint 10B to be applied inexpensively to the surfaces of the furniture or fixtures and reducing the manufacturing costs of the furniture or fixtures. The dispersed (dissolved) microbubbles 14 and / or nanobubbles 15 in the paint 10B applied to the surfaces of the furniture or fixtures reduces the viscosity of the paint 10B, making it easier to apply the paint 10B to the surfaces of the furniture or fixtures and shortening the application time for the paint 10B to the surfaces of the furniture or fixtures. The mass of paint 10B per unit volume of furniture and fixtures is reduced compared to when microbubbles 14 and nanobubbles 15 are not dispersed and mixed (dispersed and dissolved) in paint 10B, and therefore when paint 10B is applied to the surface of furniture and fixtures, the increase in weight of the furniture and fixtures including coating film 13 formed from paint 10B can be minimized.

[0130] Other examples of substrates 11 (objects) to which the coating material 10B containing dispersed microbubbles 14 and / or nanobubbles 15 can be applied include metal molded products, plastic molded products, glass molded products, rubber molded products, leather molded products, wood molded products, paper molded products, woven fabric molded products, and nonwoven fabric molded products. Metal molded products can be made from materials such as iron, aluminum, duralumin, stainless steel, copper, gold, silver, titanium, nickel, and alloys. Metal molded products made from these materials can have various shapes, such as plates, rods, and other three-dimensional shapes. Plastic molded products can be made from known thermoplastic resins such as polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyamide (nylon), vinyl chloride resin, acrylic resin, silicone resin, fluororesin, polyimide resin, and polysulfone resin, as well as thermosetting resins such as epoxy resin, melamine resin, phenolic resin, and unsaturated polyester resin. Plastic molded products made from these materials can have various shapes, such as films, sheets, plates, and other three-dimensional shapes.

[0131] As an example of a method for applying a fluororesin paint, first, a degreasing treatment is performed on the substrate 11. In the degreasing treatment, the substrate 11 is heated in a furnace and baked at a temperature higher than the baking temperature to thermally decompose oils, grease, and dirt. Alternatively, if the substrate is made of a material or has a shape that is not suitable for baking, solvent cleaning is performed to clean dirt and oil with a solvent.

[0132] Next, surface preparation (pretreatment) is performed. In surface preparation, the surface 12 (painted surface) of the substrate 11 is blasted with Morundum or grit abrasives and air to remove rust, dirt, etc., and roughen to a thickness of approximately 3 to 6 microns (blasting). Alternatively, if blasting is not possible or depending on the intended function, etching or chemical coating treatment may be used for surface preparation. After surface preparation, a primer is applied to the surface 12 (painted surface) of the substrate 11 to improve adhesion between the substrate 11 and the fluororesin (primer coating). Next, the primer is baked in an oven (baking).

[0133] After baking, the fluororesin paint is applied to the surface 12 (coated surface) of the substrate 11 using a coating device such as a brush, roller, dipping, spray, roll coater, die coater, applicator, or spin coater. After the fluororesin paint is applied, it is dried to form a coating film. The drying temperature for the fluororesin paint is between room temperature and about 300°C. If the fluororesin paint is dried by heating, it is baked in a baking furnace.

[0134] Silicone resin paint, acrylic resin paint, urethane resin paint, and water-based paint are applied by a coating method suited to the shape of the substrate 11 (various articles). For example, they can be applied by spraying, dipping, brushing, roll coating, gravure coating, flexography, inkjet coating, etc. The drying temperature for silicone resin paint is room temperature to about 50°C. The drying temperature for acrylic resin paint is room temperature to about 120°C. The drying temperature for urethane resin paint is room temperature to about 100°C. When applying silicone resin paint, acrylic resin paint, and urethane resin paint, as with fluororesin paint, abrasive grit and air blasting may be used to remove rust, dirt, etc., and a surface roughening treatment may be performed to roughen the surface to about 3 to 6 microns.

[0135] Fluorine resin paint, silicone resin paint, acrylic resin paint, urethane resin paint, and water-based paint may be applied in a single layer or in multiple layers. There are no particular limitations on the amount of fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint applied, and the amount is determined according to the surface performance required of the substrate 11 (various articles) to be applied. The coating film formed by drying the fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, or water-based paint has a coating thickness in the range of 60 to 300 μm, preferably 90 to 270 μm. The coating thickness of the coating film was measured using an electromagnetic film thickness gauge, an eddy current film thickness gauge, or an outside micrometer.

[0136] The microbubbles 14 and / or nanobubbles 15 mixed (dissolved) inside the paint 10B applied to a predetermined film thickness (60 to 300 μm, preferably 90 to 270 μm) have particle sizes that gradually increase from the bottom to the top of the paint 10B within the above range. Therefore, the particle sizes of the microbubbles 14 and / or nanobubbles 15 located at the bottom of the paint 10B are the smallest, the particle sizes of the microbubbles 14 and / or nanobubbles 15 located at the top of the paint 10B are the largest, and the particle sizes of the microbubbles 14 and / or nanobubbles 15 located in the middle of the paint 10B are intermediate between those of the microbubbles 14 and / or nanobubbles 15 located at the bottom and top of the paint 10B.

[0137] In the drying process after emulsion-based (water-based) paint 10B is applied to surface 12 (coated surface) of substrate 11, as shown in Figure 7, the solvent (water) gradually evaporates, and the polymer particles dissolved in the solvent (water) deform and fuse together. Subsequently, interdiffusion of polymer chains occurs, completing film formation and forming a coating film 13 that coats surface 12 of substrate 11. The coating film 13 formed from emulsion-based paint 10 has a thickness in the range of 20 to 110 μm, preferably 30 to 90 μm.

[0138] The coating film 13 formed by drying and hardening the emulsion-based coating material 10B on the surface 12 of the substrate 11 (various articles) contains bubbles with an average particle diameter D ５０ The average particle diameter D of the microbubbles 14 and / or air bubbles is 100 μm or less ５０ Nanobubbles 15 having a size of 0.5 μm or less, preferably 1 nm or more and 800 nm or less, more preferably 1 nm or more and 300 nm or less, remain trapped without evaporating into the outside air, and microbubbles 14 and / or nanobubbles 15 are dispersed and mixed (dispersed and dissolved) at a predetermined concentration. The microbubbles 14 and / or nanobubbles 15 dispersed and mixed inside the coating film 13 made from the emulsion-based paint 10B are mixed in the form of spheres with high internal bubble pressure, similar to the state in which they were dispersed and mixed in the paint 10B.

[0139] 1 cm of the coating film 13 made from the emulsion-based coating material 10B in which microbubbles 14 and / or nanobubbles 15 are dispersed and mixed. ３ The total number of microbubbles 14 per ５ pieces / cm ３ 10 above １２ pieces / cm ３ The coating film 13 is in the following range: ３ The total number of nanobubbles per 10 ５ pieces / cm ３ 10 above １２ pieces / cm ３ It is in the following range:

[0140] In the drying process after the solvent-based paint 10B is applied to the surface 12 (coated surface) of the substrate 11, as shown in Figure 8, the solvent gradually volatilizes, and the polymer chains dissolved in the solvent gradually shrink, causing mutual diffusion of the polymer chains, completing film formation and forming a coating film 13 that coats the surface 12 of the substrate 11. The coating film 13 formed from the solvent-based paint 10 has a film thickness in the range of 20 to 110 µm, preferably 30 to 90 µm.

[0141] The coating film 13 formed by drying and curing the solvent-based coating material 10B on the surface 12 of the substrate 11 (various articles) contains bubbles with an average particle diameter D ５０ The average particle diameter D of the microbubbles 14 and / or air bubbles is 100 μm or less ５０ Nanobubbles 15 having a size of 0.5 μm or less, preferably 1 nm or more and 800 nm or less, more preferably 1 nm or more and 300 nm or less, remain trapped without evaporating into the outside air, and microbubbles 14 and / or nanobubbles 15 are dispersed and mixed (dispersed and dissolved) at a predetermined concentration. The microbubbles 14 and / or nanobubbles 15 dispersed and mixed inside the coating film 13 made from the solvent-based coating material 10B are mixed in the form of spheres with high internal bubble pressure, similar to the state in which they were dispersed and mixed in the coating material 10B.

[0142] 1 cm of the coating film 13 made from the solvent-based paint 10B in which the microbubbles 14 and / or nanobubbles 15 are dispersed and mixed. ３ The total number of microbubbles 14 per ５ pieces / cm ３10 above １２ pieces / cm ３ The coating film 13 is in the following range: ３ The total number of nanobubbles per 10 ５ pieces / cm ３ 10 above １２ pieces / cm ３ It is in the following range:

[0143] Microbubbles 14 and / or nanobubbles 15 are introduced (mixed) into paint 10B (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, water-based paint), and the closed-cell microbubbles 14 and / or nanobubbles 15 are dispersed and mixed (dispersed and dissolved) inside paint 10B at a predetermined concentration. Therefore, the proportion of paint 10B itself per unit volume of paint 10B can be reduced by the microbubbles 14 and nanobubbles 15, and the amount of paint 10B applied when paint 10B is applied to surface 12 of substrate 11 to be applied is reduced, making it possible to reduce the amount of paint 10B applied to substrate 11.

[0144] Compared to when the microbubbles 14 and / or nanobubbles 15 are not dispersed in the paint 10B (fluororesin paint, silicone resin paint, acrylic resin paint, urethane resin paint, water-based paint), the amount of paint applied can be reduced, thereby lowering the unit price of the paint 10B per unit area of ​​the surface 12 of the substrate 11 and allowing the paint 10B to be applied inexpensively. Even if the substrate 11 on which the fluororesin coating film 13 made from the fluororesin paint, the silicone resin coating film 13 made from the silicone resin paint, the acrylic resin coating film 13 made from the acrylic resin paint, the urethane resin coating film 13 made from the urethane resin paint, or the coating film 13 made from the water-based paint is formed is damaged, the coating film 13 made from the paint 10B can protect the substrate 11 from various damages and prevent deterioration of the substrate 11 due to the damage.

[0145] FIG. 9 shows an example of the paint 10B of the present invention and a comparative example of the paint 10B of the present invention. As examples of the paint 10B, a one-component curing water-based paint was used as the paint 10B, and a nanobubble-free one-component curing water-based paint (no nanobubbles (NB)) and a nanobubble-containing one-component curing water-based paint (paint 10B) (methods A and B) were prepared. (No nanobubbles (NB)) was a one-component curing water-based paint in which nanobubbles were not introduced and the paint was not diluted with water. (Method A) was a one-component curing water-based paint in which nanobubbles were dispersed and mixed by introducing nanobubbles into a one-component curing water-based paint in which nanobubbles were not introduced by a static mixer method, resulting in a nanobubble-containing one-component curing water-based paint in which nanobubbles were dispersed and mixed. (Method B) was a one-component curing water-based paint in which nanobubbles were dispersed and mixed by introducing nanobubbles into a one-component curing water-based paint in which nanobubbles were not contained by an ultrasonic method, resulting in a nanobubble-containing one-component curing water-based paint in which nanobubbles were dispersed and mixed.

[0146] Comparative examples for paint 10B include a nanobubble (NB)-free one-component curing water-based paint that is not diluted with water (a nanobubble (NB)-free one-component curing water-based paint before dilution), a nanobubble (NB)-free one-component curing water-based paint diluted with 1% water (a nanobubble (NB)-free one-component curing water-based paint with 1% water added), and a nanobubble (NB)-free one-component curing water-based paint diluted with 5% water (a nanobubble (NB)-free one-component curing water-based paint with 5% water added). A nanobubble (NB)-free one-component curing water-based paint diluted with 10% water (a nanobubble (NB)-free one-component curing water-based paint with 10% water added), a nanobubble (NB)-free one-component curing water-based paint diluted with 15% water (a nanobubble (NB)-free one-component curing water-based paint with 15% water added), and a nanobubble (NB)-free one-component curing water-based paint diluted with 20% water (a nanobubble (NB)-free one-component curing water-based paint with 20% water added) were prepared.

[0147] The viscosity (mPa s) at room temperature of 20°C was measured for the nanobubble-free one-component curing water-based paint of the Examples, the nanobubble-containing one-component curing water-based paint of Type A, the nanobubble-containing one-component curing water-based paint of Type B, the nanobubble-free one-component curing water-based paint of the Comparative Examples before dilution with water, the nanobubble-free one-component curing water-based paint with 1% water added, the nanobubble-free one-component curing water-based paint with 5% water added, the nanobubble-free one-component curing water-based paint with 10% water added, the nanobubble-free one-component curing water-based paint with 15% water added, and the nanobubble-free one-component curing water-based paint with 20% water added.

[0148] Furthermore, the viscosity (mpa s) was measured for the nanobubble-free one-component curing water-based paint before heating (20°C), the nanobubble-free one-component curing water-based paint heated to 25°C, the nanobubble-free one-component curing water-based paint heated to 30°C, the nanobubble-free one-component curing water-based paint heated to 40°C, the nanobubble-free one-component curing water-based paint heated to 50°C, and the nanobubble-free one-component curing water-based paint heated to 60°C.

[0149] The viscosity measurements showed that the nanobubble-free one-component curing water-based paint of the example had a viscosity of 718 (mPa·s), the nanobubble-containing one-component curing water-based paint of example A type had a viscosity of 682 (mPa·s), and the nanobubble-containing one-component curing water-based paint of example B type had a viscosity of 99 (mPa·s). The viscosity of the comparative example one-component curing water-based paint not containing nanobubbles before dilution with water was 718 (mPa·s), the viscosity of the comparative example one-component curing water-based paint not containing nanobubbles with 1% water added was 665 (mPa·s), the viscosity of the comparative example one-component curing water-based paint not containing nanobubbles with 5% water added was 414 (mPa·s), the viscosity of the comparative example one-component curing water-based paint not containing nanobubbles with 10% water added was 258 (mPa·s), the viscosity of the comparative example one-component curing water-based paint not containing nanobubbles with 15% water added was 172 (mPa·s), and the viscosity of the comparative example one-component curing water-based paint not containing nanobubbles with 20% water added was 102 (mPa·s).

[0150] Furthermore, the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example before heating (20°C) was 718 (mPa·s), the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example heated to 25°C was 583 (mPa·s), the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example heated to 30°C was 385 (mPa·s), the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example heated to 40°C was 319 (mPa·s), the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example heated to 50°C was 186 (mPa·s), and the viscosity of the nanobubble-free one-component curing water-based paint of the comparative example heated to 60°C was 89 (mPa·s).

[0151] As a result of the above, it was found that by dispersing and mixing nanobubbles into the one-component curing water-based paint, it is possible to reduce the water dilution by 1% in the one-component curing water-based paint, and that the viscosity (99 MPa·s) of the one-component curing water-based paint containing nanobubbles of type B far exceeds the recommended dilution amount of one-component curing water-based paint by 5%, equivalent to a water dilution amount of 20%, and is comparable to the viscosity of one-component curing water-based paint heated to 60°C. The one-component curing water-based paint of type B, which contains more nanobubbles than the one-component curing water-based paint of type A, has a greater decrease in viscosity due to the large amount of nanobubbles dispersed and mixed in the water-based paint. It is thought that the more nanobubbles are introduced into the one-component curing water-based paint, the lower the viscosity of the water-based paint.

[0152] 10A Paint 10B Paint with dispersed microbubbles and / or nanobubbles mixed therein 11 Substrate 12 Surface (outer surface, inner surface) 13 Coating film 14 Microbubbles 15 Nanobubbles 16 Microbubble / nanobubble mixing device 17 Coating liquid water storage tank 18 Gas supply tank 19 Water supply pump 20 Air supply pump 21 Static fluid mixer (microbubble / nanobubble generator) 22 Coating liquid storage tank 23 Water supply pipe 24 Air supply pipe 25 Mixing pipe 26 Supply pipe 27 Cylindrical unit 28 Honeycomb structure element (agitating blade)

Claims

1. A coating material that is applied to the surface of a substrate to be coated and forms a coating film on the surface of the substrate, wherein microbubbles and / or nanobubbles are introduced into the coating material, and the microbubbles and / or nanobubbles are dispersed and mixed within the coating material at a predetermined concentration.

2. Average particle size D of the microbubbles and / or nanobubbles ５０ The coating material according to claim 1, wherein the particle size is 100 μm or less.

3. Average particle size D of the microbubbles and / or nanobubbles ５０ The coating material according to claim 2, wherein the particle size is 0.5 μm or less.

4. The microbubbles and / or nanobubbles contained in 1 ml of the paint are 10 ５ pcs / ml or more 10 １２ 4. The paint according to claim 3, wherein the concentration is less than or equal to 1 / ml.

5. The paint according to claim 4, wherein the microbubbles and / or the nanobubbles are undergoing Brownian motion inside the paint.

6. The paint according to claim 5, wherein the viscosity of the paint after the microbubbles and / or nanobubbles are introduced is lower than that of the paint before the microbubbles and / or nanobubbles are introduced.

7. The paint according to claim 6, wherein the viscosity of the paint after the microbubbles and / or nanobubbles are introduced is in the range of 1 to 1000 mPa·s.

8. The paint according to claim 7, wherein the gas forming the microbubbles and / or the nanobubbles is any one of air, nitrogen, argon, helium, xenon, neon, krypton, radon, hydrogen, oxygen, ozone, methane, ethylene, propane, butane, acetylene, ethanol, fluorine, chlorine, bromine, iodine, ammonia, hydrogen sulfide, sulfur dioxide, carbon monoxide, and carbon dioxide, or a mixed gas of two or more of these.

9. The paint according to claim 8, wherein the paint is any one of a fluororesin paint, a silicon resin paint, an acrylic resin paint, a urethane resin paint, and a water-based paint.

10. A paint manufacturing method for manufacturing the paint according to any one of claims 1 to 8, characterized in that the paint manufacturing method introduces the microbubbles and / or nanobubbles into the paint by utilizing any one of a pressurized dissolution method, a micropore and porous method, an ejector method, a Venturi method, an ultrasonic method, a static mixer method, a cavitation method, a swirling liquid flow method, and a shear method, or a combination of these methods.

11. A structure in which the object to be coated with the paint according to any one of claims 1 to 9 is a structure, the paint is applied to the surface of the structure, and a coating film is formed on the surface of the structure by the hardened paint.

12. A moving body, characterized in that the object to be coated with the paint according to any one of claims 1 to 9 is a moving body, the paint is applied to a surface of the moving body, and a coating film is formed on the surface of the moving body by the hardened paint.

13. An industrial product characterized in that the object to be coated with the paint according to any one of claims 1 to 9 is an industrial product, the paint is applied to a surface of the industrial product, and a coating film is formed on the surface of the industrial product by the hardened paint.

14. Furniture or equipment, characterized in that the object to be coated with the paint according to any one of claims 1 to 9 is furniture or equipment, the paint is applied to the surface of the furniture or equipment, and a coating film is formed on the surface of the furniture or equipment by the hardened paint.

Images