Water-based paint composition, air purification mechanism, and air purification method

Abstract

The present invention provides a water-based paint composition, an air purification mechanism, and an air purification method that can form a high-quality coating film and exhibit sufficient air purification functionality in indoor spaces. [Solution] The water-based paint composition has the following composition. Cationic acrylic ester copolymer aqueous emulsion: 100 parts by weight, water: 100 parts by weight, 5000 mesh white charcoal powder (median particle size 1 μm): 66.7 parts by weight, 3000 mesh mixture of white charcoal powder and black charcoal powder (median particle size 5 μm): 33.3 parts by weight, titanium dioxide: 1 part by weight, sodium polycarboxylate: 1 part by weight, sodium polyacrylate: 1 part by weight.

Description

[Technical Field]

[0001] The present invention relates to an aqueous coating composition, an air purification mechanism, and an air purification method. More specifically, it relates to an aqueous coating composition, an air purification mechanism, and an air purification method that can form a high-quality coating film and exhibit sufficient air purification function in indoor spaces. [Background technology]

[0002] Paints are applied to the surface of objects for purposes such as protection, aesthetics, and functionality. The objects to which paints are applied are diverse, including buildings, vehicles, electrical machinery, metal products, furniture, and leather, and various types of paints exist depending on their intended use.

[0003] Furthermore, among the various uses of paints, interior paints applied to the walls and ceilings of buildings, especially indoor spaces, contribute not only to protecting the painted surface and improving its aesthetic appeal, but also to improving the environment of the indoor space. These interior paints are mainly composed of synthetic resins, pigments, additives, and solvents.

[0004] Paints that contribute to improving the environment of indoor spaces have the ability to reduce or adsorb harmful or unpleasant substances such as dust and dirt in indoor spaces, chemical substances such as formaldehyde and volatile organic compounds (VOCs) contained in furniture and building materials, and odors from cigarettes, pets, etc.

[0005] In this context, one example of a paint that attempts to efficiently adsorb harmful substances in the air within an indoor space is the water-based paint composition described in Patent Document 1.

[0006] The aqueous paint composition described in Patent Document 1 has a composition in which the total weight ratio of the paint composition is as follows: cationic acrylic ester copolymer aqueous emulsion: 29.07%, water: 29.07%, 1500 mesh charcoal powder (central particle size 10 μm): 19.38%, 3000 mesh charcoal powder (central particle size 5 μm): 9.69%, aluminum hydroxide: 4.84%, acrylic polymer: 2.91%, preservative: 2.91%, urethane modified polyether: 1.94%, antifungal agent: 0.10%, and silicone-based defoamer: 0.01%.

[0007] The aqueous paint composition described in Patent Document 1 contains conductive charcoal powder and is used in an air purification mechanism for indoor spaces.

[0008] More specifically, the aqueous paint composition described in Patent Document 1 purifies the air in indoor spaces by capturing positively charged particles in the air. For example, exhaust gases and particulate matter such as PM2.5 tend to exist in the atmosphere with positively charged constituent particles. In addition, ammonium ions are mainly present in the air.

[0009] Therefore, in the aqueous paint composition described in Patent Document 1, by connecting a negative voltage generator to the coating surface of the conductive paint and charging the coating surface with a negative voltage, it becomes possible to capture the positively charged particles mentioned above and purify the air in the indoor space. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 6385026 [Overview of the project] [Problems that the invention aims to solve]

[0011] However, the aqueous coating composition disclosed in Patent Document 1 had room for improvement in terms of further enhancing its effect of adsorbing harmful substances such as formaldehyde in indoor spaces by utilizing its conductive properties.

[0012] Furthermore, while paints containing alcoholic solvents (alcoholic paint compositions) are widely used to impart conductivity, they have the following drawbacks.

[0013] First, as a premise, in a conductive paint, the charcoal powder particles in the paint come into contact with each other, and the conductivity of the paint is ensured through these particles.

[0014] Here, alcohol-based paint compositions require less synthetic resin to form a coating film containing charcoal powder than water-based paint compositions, resulting in a thinner resin layer and thus superior conductivity. However, due to the low amount of synthetic resin in alcohol-based paint compositions, the coating film has low flexibility and is prone to cracking in response to deformation of the substrate.

[0015] Cracks in the paint film create electrically discontinuous regions, resulting in a problem of reduced paint conductivity. Furthermore, major alcoholic solvents, such as ethanol, methanol, and 1-propanol, are volatile organic compounds (VOCs) that can harm human health. Therefore, from a safety perspective, there is a demand to replace them with water-based paint compositions.

[0016] Thus, conventional conductive paints are insufficient in terms of conductivity, coating performance, and safety.

[0017] The present invention was conceived in view of the above points, and aims to provide an aqueous coating composition, an air purification mechanism, and an air purification method that can form a coating film of excellent quality and exhibit sufficient air purification function in indoor spaces. [Means for solving the problem]

[0018] To achieve the above object, the aqueous paint composition of the present invention contains a binder made of a synthetic resin, a first carbon material which is a powder with a median particle size of 1 μm, a second carbon material which is a powder with a median particle size of 5 μm, titanium oxide, a dispersant, and water.

[0019] Here, by containing a binder made of a synthetic resin, the synthetic resin becomes the main constituent of the coating film. That is, the synthetic resin connects the particles of the first carbon material and the second carbon material to form a coating film.

[0020] In addition, the first carbon material and the second carbon material function as aggregates that give the resin thickness and strength, and impart conductivity to the aqueous paint composition. Further, the first carbon material and the second carbon material adsorb odors, chemical substances, moisture, etc. Here, the carbon material referred to is a material having conductivity with carbon as the main component. For example, it is a material obtained by carbonizing plants such as broad-leaved trees, coniferous trees, bamboo, and palm (charcoal), activated carbon, black carbon, etc., alone or in a mixture of multiple types.

[0021] In addition, by containing the first carbon material which is a powder with a median particle size of 1 μm and the second carbon material which is a powder with a median particle size of 5 μm, when the paint is applied to the base material, the first carbon material with a smaller particle size enters between the second carbon materials with a larger particle size, enhancing the uniformity of the packing state of the particles of the first carbon material and the second carbon material, and improving the packing rate of the carbon material per unit area. Here, the base material means an area to which the paint is applied, or an area where the coating film surface of the paint is provided through an intermediate member such as an insulating layer. More specifically, the base material is a plate-like body attached to a frame-like base structure constituting a wall surface.

[0022] In addition, since the uniformity of the packing state of the particles of the first carbon material and the second carbon material is enhanced, the coating film surface of the paint becomes uniform (the film thickness is uniform), and the film-forming property, flexibility, surface contamination property, and surface scratch adhesion property can be made good. Also, the appearance of the coating film can be improved.

[0023] Furthermore, by combining the first carbon material, which is a powder with a central particle size of 1 μm, with the second carbon material, which is a powder with a central particle size of 5 μm, the contact area between the particles of the first and second carbon materials is increased, thereby improving the conductivity of the paint. In addition, the strength of the coating film can be increased.

[0024] Furthermore, as the uniformity of the particle packing state of the first and second carbon materials is increased, when the entire coating surface is viewed as an electrode surface that charges with a negative voltage, the unevenness of the electrical resistance value on the coating surface is reduced, and the collection efficiency of positively charged particles (positive ions) in the air can be increased.

[0025] Furthermore, by using particles of the first and second carbon materials, which have relatively small particle sizes, the surface area of ​​the first and second carbon materials increases, thereby improving the adsorption efficiency of odors, chemical substances, moisture, etc.

[0026] Furthermore, by containing titanium dioxide, it exhibits photocatalytic activity when irradiated with light, generating radicals (hydroxyl radicals and superoxide radicals) on the surface of the titanium dioxide. This generates a strong oxidizing power that can remove harmful substances such as organic matter, bacteria, and mold that come into contact with it.

[0027] Furthermore, by including a first carbon material with a central particle size of 1 μm, a second carbon material with a central particle size of 5 μm, and titanium dioxide, the conductivity, specific surface area, photocatalytic properties, mechanical properties, and chemical stability of the paint can be improved, and the efficiency of radical generation can be enhanced. Details of these advantages are described below.

[0028] First, by combining a first carbon material and a second carbon material consisting of appropriately sized particles with titanium dioxide, even if titanium dioxide, which has low conductivity on its own, is included in the paint, the presence of the first and second carbon materials makes the overall conductivity of the paint good.

[0029] Furthermore, by combining a first carbon material and a second carbon material consisting of appropriately sized particles with titanium dioxide, although titanium dioxide alone does not have the adsorption capacity to adsorb harmful substances such as formaldehyde, the first and second carbon materials have a high specific surface area and excellent adsorption capacity, so the paint as a whole can effectively adsorb harmful substances such as formaldehyde. As a result, the photocatalytic effect of titanium dioxide is more easily exerted on the adsorbed formaldehyde, etc., and the efficiency of removing harmful substances can be increased.

[0030] Furthermore, by combining the first and second carbon materials with titanium dioxide, the electrical properties of the first and second carbon materials can improve the responsiveness of titanium dioxide to visible light. That is, the photocatalytic effect of titanium dioxide can occur not only in the ultraviolet wavelength range but also in a wider wavelength range including visible light, increasing the amount of radicals generated. In addition, even in a dark room where light is blocked, the electrical properties of the first and second carbon materials, i.e., the movement of free electrons based on the conductivity of the two carbon materials, influence the movement of electrons in titanium dioxide, making it possible to activate titanium dioxide in a light-free environment and utilize its strong oxidizing power.

[0031] Furthermore, by combining the first and second carbon materials with titanium dioxide, the amount of radicals generated by the photocatalytic action of titanium dioxide can be increased. Specifically, when titanium dioxide absorbs light, electrons and holes are generated, and the first and second carbon materials capture the electrons, thereby suppressing the recombination of electrons and holes, extending the lifespan of the holes, and increasing the amount of radicals generated. In addition, the first and second carbon materials function as electron donors, improving the reactivity and chemical stability of titanium dioxide, and enabling sustained radical generation.

[0032] Furthermore, by including a dispersant, the first carbon material, the second carbon material, and titanium dioxide can be uniformly dispersed in the paint. As a result, the adsorption capacity of the first and second carbon materials for harmful substances such as formaldehyde, and their function of improving the conductivity of the paint, can be fully utilized. In addition, the function of titanium dioxide, such as the removal of harmful substances based on its photocatalytic action, can be fully utilized.

[0033] Furthermore, by including water, the synthetic resin, the first carbon material, the second carbon material, titanium dioxide, and the dispersant can be dispersed using water as the base material.

[0034] Furthermore, when titanium dioxide is blended in the range of 0.5 to 1.0 parts by weight per 100 parts by weight of the carbon material containing the first carbon material and the second carbon material, the mold-inhibiting effect and the formaldehyde adsorption effect of the paint can be further enhanced.

[0035] Furthermore, when the second carbon material is blended in an amount of 20 to 100 parts by weight per 100 parts by weight of the first carbon material, the conductivity of the paint and its adsorption effect on formaldehyde can be further enhanced. In addition, the functionality due to the oxidizing power generated by titanium dioxide can be further enhanced.

[0036] Furthermore, if the dispersant comprises a first dispersant consisting of sodium polycarboxylate and a second dispersant consisting of sodium polyacrylate, the first dispersant can uniformly disperse the first carbon material and the second carbon material, and the second dispersant can uniformly disperse titanium dioxide. That is, sodium polycarboxylate has carboxyl groups (-COO ‐ It has many carboxyl groups (-COO) and becomes negatively charged in water, adsorbing onto the particle surfaces of the first and second carbon materials. By becoming negatively charged, electrostatic repulsion occurs between the particles, suppressing aggregation of the carbon material particles. In addition, sodium polyacrylate dissolves in water and has carboxyl groups (-COO). ‐Because it has the properties of adsorbing onto the surface of titanium dioxide particles, it can increase electrostatic repulsion between particles and promote dispersion. In addition, it prevents titanium dioxide from being covered by the first and second carbon materials, making it possible to uniformly arrange titanium dioxide on the surface of the coating film. Furthermore, because sodium polycarboxylate has a chelating effect, it strongly binds to calcium and magnesium ions contained in the carbon materials, reducing the amount of these ions in the paint. As a result, it is possible to suppress sodium polyacrylate from forming salts with calcium or magnesium in the solution, thereby reducing the performance of sodium polyacrylate as a dispersant.

[0037] Furthermore, when the first dispersant is blended in an amount of 1.0 part by weight per 100 parts by weight of a carbon material containing the first carbon material and the second carbon material, the first dispersant can disperse the first carbon material and the second carbon material even more effectively. In addition, a decrease in the viscosity of the paint can be suppressed.

[0038] Furthermore, when 100 parts by weight of the second dispersant are blended with 100 parts by weight of titanium dioxide, the titanium dioxide can be dispersed even more effectively by the second dispersant. In addition, a decrease in the viscosity of the paint can be suppressed.

[0039] Furthermore, in order to achieve the above objective, the air purification mechanism of the present invention is an air purification mechanism that charges a coating surface coated with a conductive aqueous coating composition with a negative voltage using a negative voltage generating means, The aqueous paint composition contains a binder made of synthetic resin, a first carbon material which is a powder with a central particle size of 1 μm, a second carbon material which is a powder with a central particle size of 5 μm, titanium dioxide, a dispersant, and water.

[0040] Here, by including a first carbon material, which is a powder with a central particle size of 1 μm, a second carbon material, which is a powder with a central particle size of 5 μm, and titanium dioxide, the conductivity, specific surface area, photocatalytic properties, mechanical properties, and chemical stability of the paint can be improved, and the efficiency of radical generation can be improved.

[0041] Furthermore, by charging a coated surface with a conductive water-based paint composition to a negative voltage using a negative voltage generating means, an electrical attraction is generated on the surface of the coated surface, allowing it to capture positively charged particles (positive ions) present in the surrounding air. Positive ions in the air can cause increased oxidative stress in the body or oxidation of oils in a room. Therefore, by capturing positive ions in the air, it is possible to exert an antioxidant effect both inside and outside the body, providing an antioxidant environment.

[0042] Furthermore, the amount of water-based paint composition applied to the painted surface is 100-300 g / m². 2 • When within the wet range, the amount of paint applied is not excessive, and for example, when applying the paint to the substrate manually using a roller or other equipment, the paint can be applied in 1-2 passes.

[0043] Furthermore, when the generated voltage on the coating surface, which has been charged to a negative voltage by the negative voltage generating means, is within the range of -50 to -150V, the electrical attractive force on the coating surface becomes sufficient, and the efficiency of capturing positively charged particles present in the air surrounding the coating surface can be increased. For example, in an indoor space surrounded by four walls and a ceiling, instead of applying paint to multiple surfaces, applying it to just one wall or ceiling surface and charging it to a negative voltage makes it possible to sufficiently purify the air in the indoor space.

[0044] Furthermore, in order to achieve the above objectives, the air purification method of the present invention comprises the steps of applying a conductive aqueous coating composition containing a binder made of synthetic resin, a first carbon material which is a powder with a central particle size of 1 μm, a second carbon material which is a powder with a central particle size of 5 μm, titanium dioxide, a dispersant, and water to at least one surface of a plurality of wall or ceiling surfaces constituting an indoor space, and charging the coated surface to which the aqueous coating composition has been applied with a negative voltage.

[0045] In this process, by applying a conductive aqueous coating composition containing a first carbon material, which is a powder with a central particle size of 1 μm, a second carbon material, which is a powder with a central particle size of 5 μm, and titanium dioxide, the conductivity, specific surface area, photocatalytic properties, mechanical properties, and chemical stability of the coated coating can be improved, and the efficiency of radical generation from titanium dioxide can be improved.

[0046] Furthermore, by applying the water-based paint composition to at least one of the multiple wall or ceiling surfaces that constitute the interior space, a coating can be formed on the wall or ceiling surface. In addition, this coating not only protects the wall or ceiling surface but also imparts conductivity.

[0047] Furthermore, by a process of charging the coated surface of the water-based paint composition with a negative voltage, the coated surface can be made into a negatively charged electrode surface. As a result, an electrical attraction is generated on the surface of the coated surface, and positively charged particles present in the surrounding air can be collected.

[0048] Furthermore, if the first and second carbon materials are fired at different temperatures, with the first carbon material fired at a temperature of 1,000°C or higher and the second carbon material fired at a temperature of 600°C or higher, it is possible to improve the conductivity of the paint while expanding the range of odor-causing substances that can be adsorbed. Specifically, the first carbon material fired at a temperature of 1,000°C or higher readily adsorbs acidic odor-causing substances, while the second carbon material fired at a temperature of 600°C or higher readily adsorbs alkaline odor-causing substances. As a result, the paint as a whole can widely adsorb both acidic and alkaline odor-causing substances, making it a paint that contributes even more to improving the odor in indoor spaces. [Effects of the Invention]

[0049] The water-based paint composition according to the present invention is capable of forming a high-quality coating film and exhibiting sufficient air purification function in indoor spaces. Furthermore, the air purification mechanism according to the present invention is capable of forming a high-quality coating film and exhibiting sufficient air purification functionality in indoor spaces. Furthermore, the air purification method according to the present invention is capable of forming a high-quality coating film and exhibiting sufficient air purification functionality in indoor spaces. [Brief explanation of the drawing]

[0050] [Figure 1] This is an explanatory diagram illustrating the general outline of the air purification mechanism according to the present invention. [Figure 2] This is a perspective view illustrating the painted surface on the substrate and its surrounding structure. [Modes for carrying out the invention]

[0051] Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, using Figure 1 as a reference, the position of the floor surface relative to the ceiling surface 2 is defined as "down" or "below," and the position of the ceiling surface 2 relative to the floor surface is defined as "up" or "above." Also, using Figure 2 as a reference, the direction of the base material 11a as seen from the finishing material 7 is defined as the "base material side," and the direction of the finishing material 7 as seen from the base material 11a is defined as the "indoor side."

[0052] (Air purification mechanism A) In an example of an air purification mechanism to which the present invention is applied, air purification mechanism A purifies the air in an indoor space 3 surrounded by multiple walls 1 and ceiling 2, as shown in Figure 1. In air purification mechanism A, a coating surface 41 of paint 4 (described later) is formed on the wall surface 11, and there is a negative voltage generator 5 that negatively charges the coating surface 41.

[0053] In other words, the air purification mechanism A combines the paint 4 and the negative voltage generator 5 to purify the air in the indoor space 3. The paint 4 is an example of an aqueous paint composition to which the present invention is applied, and its detailed composition will be described later.

[0054] (Negative voltage generator 5) The negative voltage generator 5 has a positive electrode 51 and a negative electrode 52 (see Figures 1 and 2), is connected to a predetermined power supply 54 (see Figure 2), and is a device that applies a voltage to the painted surface 41 of the wall surface 11 that is in contact with the wiring by the negative electrode 52, thereby negatively charging the painted surface 41.

[0055] The tip of the negative electrode 52 is in direct contact with the coated surface 41, and this contact state is fixed via a mounting member or the like (not shown). The positive electrode 51 is connected to the earth 53 in the ground. The coated surface 41 is coated to have an insulation resistance of 1 MΩ or more relative to the earth 53 in the ground, and is configured to maintain a negatively charged state, that is, to maintain an electrically independent state of the coated surface 41.

[0056] The insulation resistance value is the resistance between the painted surface 41 and the ground 53 in the earth. The larger this value, the easier it is for the painted surface 41 to become electrically independent. The insulation resistance value also changes depending on whether or not insulating paint is applied between the painted surface 41 and the wall surface 11, whether or not an insulating sheet is provided between the painted surface 41 and the wall surface 11, whether or not the material of the base structure (frame structure that forms the skeleton of the wall) that makes up the wall surface 11 is insulating, and whether or not the material of the plate-shaped base material attached to the base structure is insulating.

[0057] Furthermore, the negative voltage generator 5 is a device that generates a device voltage of 0 to 300V, and is capable of imprinting a reference generated voltage of -50 to -150V on the coated film surface 41. The reference generated voltage referred to here corresponds to the "generated voltage" in the claims of this application.

[0058] Here, the surface on which the paint film surface 41 of the paint 4 is formed is not necessarily limited to the wall surface 11. For example, the paint 4 may also be applied to other wall surfaces 1 or ceiling surfaces 2. Alternatively, the paint 4 may be applied only to other wall surfaces 1 or only to ceiling surfaces 2. For example, depending on the size of the indoor space 3, it is possible to apply the paint 4 to the entire surfaces of multiple wall surfaces 1 and ceiling surfaces 2 from the viewpoint of ensuring sufficient air purification. Furthermore, in addition to the method of forming the paint film surface 41 of the paint 4 on the wall surface 11, it is also possible to pre-paint the gypsum board with the paint 4, attach the painted gypsum board to the ceiling or wall surface in the room, and then electrostatically charge the surface of the gypsum board.

[0059] Furthermore, while paint 4 is just a guideline, assuming it is applied only to the ceiling surface 2 of the room, the air volume of the room space 3 is 1 m³. 3 In contrast, the minimum required application area is 0.4 m². 2 It will be approximately 18 tatami mats (tatami = m²). 2 In a typical indoor space with a density of 0.3025 × 2 or less, applying paint 4 to one surface of the ceiling allows for efficient capture of positively charged particles in the air throughout the indoor space 3.

[0060] Furthermore, when applying paint 4 only to the wall surface, if the room size increases, the spatial volume will increase, and it may become impossible to secure the minimum necessary coating area on a single wall surface. In such cases, depending on the size of the room space, it is possible to sufficiently purify the air in the room space 3 by applying the paint to multiple wall surfaces.

[0061] Furthermore, it is not necessarily required that the paint 4 be applied to the entire surface of the wall 11; it is sufficient if the surface to which the paint 4 is applied is configured to become negatively charged by the negative voltage generator 5. For this reason, it is also possible to apply the paint 4 to a part of the wall 11 (for example, a certain area within the wall 11) or to multiple locations (with spaces between the applied locations). However, from the viewpoint of increasing the efficiency of capturing positively charged particles in the air by having a certain area of ​​the painted film surface act on the air in the indoor space 3, it is preferable that the paint 4 be applied to the entire surface of the wall 11.

[0062] Furthermore, the size of the indoor space 3 to which the air purification mechanism A is applied is not particularly limited; as long as there is an area such as a wall or ceiling surface to which the paint 4 can be applied, the air purification mechanism A can be used regardless of the size.

[0063] Furthermore, the negative voltage generator 5 does not necessarily need to be configured to negatively charge the coating surface 41 by directly contacting the negative electrode 52 with the coating surface 41. For example, a configuration can be adopted in which the coating surface 41 is negatively charged by using a negative charge generator such as an ion generator that can irradiate the coating surface 41 with a negative charge without contact.

[0064] Furthermore, the device output voltage of the negative voltage generator 5 does not need to be limited to the range of 0 to 300V. However, from the viewpoint of sufficiently capturing positively charged particles in the air of the indoor space 3, it is preferable to have a configuration that can apply a reference output voltage of -50 to -150V to the coating surface 41, and for this purpose, it is preferable to use a device with a device output voltage in the range of 0 to 300V for the negative voltage generator 5.

[0065] (Coated surface 41) Using Figure 2, we will explain the coated surface 41 on the wall surface 11 and its surrounding structure. The base material 11a that constitutes the wall surface 11 is a foundation (plate-like body) that forms the painted surface 41, and is made of a conductive material such as gypsum board or concrete. Below the base material 11a, a frame-shaped base structure that constitutes the framework of the wall surface 11 is formed.

[0066] Furthermore, an insulating layer 6 is provided between the base material 11a and the painted surface 41 to prevent electrical leakage from the painted surface 41 to the base material 11a. In addition, a finishing material 7 is provided on the interior side of the painted surface 41 to enhance the aesthetic appearance.

[0067] The coated surface 41 is formed by applying a paint 4 having the composition described later onto an insulating layer 6 provided on the interior side of the substrate 11a. The amount of paint 4 applied is 100 to 300 g / m². 2 It is marked as wet.

[0068] As described above, a voltage is applied to the coating surface 41 from the negative voltage generator 5, causing the coating surface 41 to become negatively charged. That is, through the conductivity of the coating surface 41, the entire coating surface becomes a negatively charged electrode surface. Here, the insulating layer 6 insulates the coating surface 41 from the base material 11a in order to maintain the coating surface 41 in an electrically independent state from the earth 53 in the ground.

[0069] The insulating layer 6 has a three-layer structure: a Japanese paper layer on the interior side, an intermediate layer made of polyethylene terephthalate, and a Japanese paper layer on the substrate side. All of the constituent materials are insulating. The insulating layer 6 is attached to the substrate 11a using wallpaper adhesive.

[0070] In the three-layer structure of the insulating layer 6, the Japanese paper layer on the substrate side allows for adhesion between the insulating sheet layer and the substrate 11a using adhesive for wallpaper application. Furthermore, the adhesion between the Japanese paper layer on the interior side and the paint 4 is enhanced. By using a paper material such as the Japanese paper layer, the adhesion of wallpaper application adhesive and the paint 4 can be improved compared to when using resin materials such as vinyl.

[0071] Here, the insulating layer 6 does not necessarily have to be a three-layer structure; it is sufficient as long as it can ensure insulation between the coated surface 41 and the substrate 11a. For example, other methods of providing an insulating layer include applying a highly insulating paint such as epoxy, polyester, urethane, or acrylic, attaching an opaque vinyl cloth, or attaching paper cloth and then applying a highly insulating paint on top of it. Furthermore, a structure using plastic materials such as polyethylene or polystyrene can be used as the intermediate layer of the three-layer structure.

[0072] Furthermore, the intermediate layer of the insulating layer 6 does not necessarily have to be made of polyethylene terephthalate; any material with electrical insulating properties is sufficient. For example, an intermediate layer coated with an insulating epoxy-based rust-preventive and waterproof paint can be used.

[0073] The finishing material 7 is a breathable cloth or a breathable color paint or the like, which is pasted or applied onto the coating film surface 41 to cover the coating film surface 41 having a black color derived from charcoal powder.

[0074] Also, although the breathable cloth, color paint, etc. constituting the finishing material 7 have insulating properties, when the coating film surface 41 on the base material 11a is charged with a negative voltage, the finishing material 7 becomes polarized and the surface of the finishing material 7 is negatively charged, so that it becomes possible to attract positively charged particles in the air in the indoor space 3.

[0075] Since the positively charged particles in the air in the indoor space 3 are very small particles (particles having a size of about 10 -7 cm to 10 -8 cm), they pass through the ventilation holes of the finishing material 7 and are attracted to the negatively charged coating film surface 41 on the base material 11a.

[0076] In the above description, the case where the base material 11a (or the base structure material) is a non-wood conductive material made of steel frame or concrete has been described. However, when the base material and the base structure material are insulating materials such as wood, a structure excluding the above-described insulating layer 6 can be adopted. That is, the paint 4 is directly applied to the wall surface of the base material 11a to form the coating film surface 41, and the finishing material 7 is provided thereon. When the base material and the base structure material are insulating materials such as wood, the insulating effect of the base material and the base structure material enables the coating film surface 41 to be maintained in an electrically independent state with respect to the ground 53 in the ground.

[0077] Furthermore, even when the base material is made of wood, when a conductive material is adopted for the base structure or when metal screws or the like are used to attach the base material to the base structure, it is preferable to provide the insulating layer 6 as described above.

[0078] In the air purification mechanism A described above, by turning on the power to the negative voltage generator 5 and applying a voltage to the painted surface 41, the painted surface 41 becomes negatively charged if it is electrically independent from the ground 53 in the earth. If the power to the negative voltage generator 5 is left on, the painted surface 41 acts as a negatively charged electrode surface, attracting positively charged harmful and unpleasant particles in the air of the indoor space 3 and capturing these particles. As a result, the air in the indoor space 3 can be purified.

[0079] The following describes the composition of an example of an aqueous paint composition to which the present invention is applied. This is an example of the composition of paint 4 described above.

[0080] The paint shown here (paint 4) has the following composition. Cationic acrylic ester copolymer aqueous emulsion: 100 parts by weight Water: 100 parts by weight 5000 mesh white charcoal powder (central particle size 1 μm): 66.7 parts by weight Mixture of 3000 mesh white charcoal powder and black charcoal powder (median particle size 5 μm): 33.3 parts by weight Titanium oxide: 1 part by weight Sodium polycarboxylate: 1 part by weight Sodium polyacrylate: 1 part by weight Furthermore, this paint composition has a viscosity of 5 Pa·s and a density of 1.22 g / cm³. 3 That is the case.

[0081] Here, the cationic acrylic ester copolymer aqueous emulsion acts as a binder and, as the main component of the coating film, binds together the carbon material powder particles to form the coating film. This acrylic ester copolymer aqueous emulsion contains approximately 45% acrylic ester copolymer and the remainder is water, and has a glass transition temperature (Tg) of 4°C.

[0082] Furthermore, water is a solvent that mixes and disperses the various components. It also serves as a base for paints.

[0083] Furthermore, 5000-mesh white charcoal powder (central particle size 1 μm) and a mixture of 3000-mesh white charcoal powder and black charcoal powder (central particle size 5 μm) are aggregates (inorganic pigments) that give thickness and strength to the resin (coating film), and are carbon materials that impart conductivity to the paint. In addition, these carbon materials impart to the paint the function of adsorbing odors, chemical substances, moisture, etc.

[0084] This paint contains a blend of two types of carbon material powders with different particle sizes. The blending ratio of the two types of carbon material powders is 66.7 parts by weight of 5000 mesh white charcoal powder to 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder. In particular, this paint combines 5000 mesh carbon material powder (central particle size 1 μm) and 3000 mesh carbon material powder (central particle size 5 μm) to improve the conductivity of the paint and enhance the functionality of titanium dioxide.

[0085] This paint incorporates two types of carbon material powders with different particle sizes, and by combining them with titanium dioxide, it is possible to improve the conductivity of the paint and enhance the functionality that titanium dioxide exhibits due to its oxidizing power.

[0086] Furthermore, 5000-mesh white charcoal powder is white charcoal made from trees of the genus Mytu (no Japanese name) in the family Hypericaceae, fired at temperatures above 1000°C. White charcoal powder is produced, for example, by firing Ubame oak at a high temperature of 1000-1400°C, preferably 1000-1200°C, and then rapidly cooling it with an appropriate amount of ash and soil. Binchotan charcoal is a representative example of white charcoal.

[0087] Furthermore, the 3000-mesh mixture of white charcoal powder and black charcoal powder is a mixture of the aforementioned white charcoal powder and black charcoal powder, which is made from trees such as oak, chestnut, sawtooth oak, and bamboo and fired at temperatures above 600°C. In addition, bamboo charcoal, activated carbon, wood charcoal, and coconut shell charcoal can also be used as raw materials for the 3000-mesh carbon material powder.

[0088] Furthermore, titanium dioxide exhibits photocatalytic activity when irradiated with light, generating radicals (hydroxyl radicals and superoxide radicals) on its surface. This generates a strong oxidizing power, making it an ingredient that removes harmful substances such as organic matter, bacteria, and mold that it comes into contact with.

[0089] Furthermore, even when using this paint in a darkroom or other light-blocked environment, the conductivity imparted to the paint by the 5000-mesh white charcoal powder and the mixture of 3000-mesh white charcoal powder and black charcoal powder influences the movement of electrons in titanium dioxide, activating titanium dioxide in a light-free environment and utilizing its powerful oxidizing ability.

[0090] Furthermore, the titanium dioxide content is 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder, totaling 1 part by weight of titanium dioxide for every 100 parts by weight of carbon material.

[0091] Furthermore, sodium polycarboxylate is a dispersant used to uniformly disperse 5000-mesh white charcoal powder and a mixture of 3000-mesh white charcoal powder and black charcoal powder. Sodium polycarboxylate is an electrostatic repulsion type dispersant with a carboxyl group content of 4 to 12 mmol / g, and it suppresses the aggregation of carbon material particles.

[0092] Furthermore, sodium polycarboxylate has chelating properties and strongly binds to calcium and magnesium ions contained in carbon materials. This prevents sodium polyacrylate from forming salts with calcium or magnesium in the solution, thus preventing a decrease in its performance as a dispersant.

[0093] Furthermore, the blending ratio of sodium polycarboxylate is 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder, totaling 1 part by weight of sodium polycarboxylate for every 100 parts by weight of carbon material.

[0094] Furthermore, sodium polyacrylate is a dispersant used to uniformly disperse titanium dioxide. Sodium polyacrylate is an electrostatic repulsion type dispersant with a carboxyl group content of 4 to 12 mmol / g, which promotes the uniform dispersion of titanium dioxide.

[0095] Furthermore, the blending ratio of sodium polyacrylate is 1 part by weight of sodium polyacrylate to 1 part by weight of titanium dioxide.

[0096] Herein, the ingredients and their proportions in this paint are not limited to those described above, and the components and their amounts can be appropriately changed as long as the functionality required by the present invention is not deviated from. An example is described in detail below.

[0097] This paint may also contain a thickening agent to adjust its viscosity. Examples of thickening agents include acrylic polymers and urethane-modified polyethers. Each thickening agent primarily consists of either an acrylic polymer or a urethane-modified polyether.

[0098] Furthermore, this paint may also be further formulated with an emulsion that provides antiseptic properties against bacteria and mold, or with preservatives or antifungal agents for water-based paints, etc.

[0099] Furthermore, this paint can also incorporate an antifoaming agent to suppress foaming within the paint. For example, a silicone-based antifoaming agent can be used.

[0100] Furthermore, in this paint, any synthetic resin with film-forming properties other than cationic acrylic ester copolymer aqueous emulsion can be used as a binder. For example, in addition to acrylic resins, other types of synthetic resins that can be used include acrylic silicone / modified silicone resins, amino alkyd resins, epoxy resins, chlorinated rubber resins, silicon resins, vinyl resins, fluororesins, phenolic resins, phthalic acid resins, unsaturated polyester resins, and polyurethane resins.

[0101] Furthermore, various types of acrylic resin paints can be used, such as emulsion-type acrylic resins, acrylic lacquers, baked acrylics, water-soluble acrylics, and acrylic alkyds. In particular, emulsion-type acrylic resins are emulsion polymers that are widely used in building interior materials and are produced by emulsion polymerization of monomers such as acrylic acid esters in water.

[0102] Here, the binder of this paint does not necessarily have to be a cationic acrylic ester copolymer aqueous emulsion. However, if the binder is cationic, the adhesion between the negatively charged carbon material powder and the binder in the paint is improved, thereby improving the strength of the paint film. Also, when the substrate to which the paint is applied has a surface that tends to be negatively charged, such as concrete or gypsum board, an electrical connection force acts between the paint and the substrate, improving the adhesion strength of the paint and forming a strong paint film. Because of these advantages based on electrical properties, it is preferable to use a cationic acrylic resin as the binder.

[0103] Furthermore, the binder of this paint does not necessarily have a glass transition temperature (Tg) of 4°C. However, using a binder with a low glass transition temperature makes it easier for the binder's glass transition temperature to be lower than the ambient temperature at which the paint is applied, suppressing the generation of shrinkage stress between the paint film and the substrate, and preventing a decrease in the adhesion of the paint film to the substrate. For this reason, it is preferable that the glass transition temperature of the binder be a low value, for example, 10°C or less. Also, in an indoor environment, the minimum indoor temperature is usually at least 5°C, so if the binder's glass transition temperature is 4°C, sufficient adhesion of the paint film can be ensured.

[0104] Furthermore, the two types of carbon materials with different particle sizes used in this coating are not necessarily limited to white charcoal powder or a mixture of white charcoal powder and black charcoal powder; conductive materials with carbon as the main component can also be used. For example, activated carbon, black carbon, etc., can be used instead of white charcoal or black charcoal. Alternatively, a material can be made by mixing multiple types of materials such as white charcoal, black charcoal, activated carbon, and black carbon.

[0105] Furthermore, it is not necessarily required that the two types of carbon materials with different particle sizes in this paint consist of white charcoal fired at 1000°C or higher and black charcoal fired at 600°C or higher. However, since white charcoal fired at 1000°C or higher readily adsorbs acidic odor-causing substances, and black charcoal fired at 600°C or higher readily adsorbs alkaline odor-causing substances, it is preferable that the two types be combined so that the entire paint can broadly adsorb acidic and alkaline odor-causing substances.

[0106] Furthermore, the raw materials for white charcoal powder are not necessarily limited to trees of the genus Mytu (no Japanese name) in the family Hypericaceae. For example, known raw materials for white charcoal such as Quercus phillyraeoides, Quercus glauca, Quercus dentata, and Magnolia obovata can also be used. For black charcoal, Quercus dentata, Quercus acutissima, Quercus serrata, Quercus crispula, and Pinus densiflora can be used as raw materials. In addition, as carbon materials, bamboo charcoal, activated carbon, wood charcoal, coconut shell charcoal, etc. can also be used.

[0107] Furthermore, the carbon material in this paint is not necessarily limited to two types with different particle sizes. For example, it is possible to add a third carbon material with a different particle size (median particle size) to create a blend of three or more types. However, due to the increased complexity of controlling the uniformity of the paint film through adjustments of the blending ratios, and the resulting higher manufacturing costs, it is preferable to use two types of carbon material with different particle sizes.

[0108] Furthermore, in this coating, the blending ratio of carbon material is not necessarily limited to 66.7 parts by weight of 5000 mesh white charcoal powder (central particle size 1 μm) and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder (central particle size 5 μm). However, from the viewpoint of improving the conductivity of the coating and enhancing the functionality of titanium dioxide, it is preferable that the mixture of 3000 mesh white charcoal powder and black charcoal powder (central particle size 5 μm) is blended in the range of 20 to 100 parts by weight for every 100 parts by weight of 5000 mesh white charcoal powder (central particle size 1 μm). Moreover, from the viewpoint of further improving the conductivity of the coating, it is even more preferable that the mixture of 3000 mesh white charcoal powder and black charcoal powder (central particle size 5 μm) is blended in the range of 33.3 parts by weight (50 parts by weight) for every 66.7 parts by weight (100 parts by weight) of 5000 mesh white charcoal powder (central particle size 1 μm).

[0109] Furthermore, in this coating, the blending ratio of titanium dioxide is not necessarily limited to 1 part by weight of titanium dioxide per 100 parts by weight of carbon material, which is the sum of 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder. However, in order to enhance the mold-inhibiting effect due to the oxidizing power of titanium dioxide and the formaldehyde adsorption effect due to the combination of carbon material and titanium dioxide, it is preferable that titanium dioxide is blended in the range of 0.5 to 1 part by weight per 100 parts by weight of carbon material, and it is even more preferable that titanium dioxide is blended in the range of 1 part by weight per 100 parts by weight of carbon material.

[0110] Furthermore, in this coating, the blending ratio of sodium polycarboxylate is not necessarily limited to 1 part by weight of sodium polycarboxylate per 100 parts by weight of carbon material, which is the sum of 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder. However, from the viewpoint of uniformly dispersing the carbon material, it is preferable to blend it at a ratio of 1 part by weight of sodium polycarboxylate per 100 parts by weight of carbon material.

[0111] Furthermore, the mixing ratio of sodium polyacrylate in this paint is not necessarily limited to 1 part by weight of sodium polycarboxylate per 1 part by weight of titanium dioxide. However, from the viewpoint of promoting the uniform dispersion of titanium dioxide, it is preferable to mix it at a ratio of 1 part by weight of sodium polyacrylate per 1 part by weight of titanium dioxide.

[0112] Furthermore, in this coating, the binder mixing ratio is not necessarily limited to 100 parts by weight of binder for every 100 parts by weight of carbon material, which is the sum of 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder. It is also possible to mix the binder in the range of 80 to 120 parts by weight for every 100 parts by weight of carbon material.

[0113] Furthermore, in this paint, the water content is not necessarily limited to 100 parts by weight of water per 100 parts by weight of carbon material, which is the sum of 66.7 parts by weight of 5000 mesh white charcoal powder and 33.3 parts by weight of a mixture of 3000 mesh white charcoal powder and black charcoal powder. It is also possible to mix water in the range of 60 to 140 parts by weight per 100 parts by weight of carbon material.

[0114] Furthermore, in aqueous paint compositions to which the present invention is applied, other components may be added as needed, in addition to the composition described above, within the limits that do not deviate from the effects of the present invention. For example, additive components that improve the functionality of the paint, such as thickeners, preservatives, fungicides, defoamers, and flame retardants, may be added separately.

[0115] Paint 4, an example of an aqueous paint composition to which the present invention described above is applied, exhibits excellent paint film performance, including improved uniformity of the painted surface, film formation, flexibility, surface stain resistance, surface scratch adhesion, paint conductivity, paint film strength, storage stability, and adhesion strength to the substrate.

[0116] Furthermore, the paint 4 to which the present invention is applied has the following advantages in more detail.

[0117] First, in paint 4, by combining 5000-mesh white charcoal powder (central particle size 1 μm) and a mixture of 3000-mesh white charcoal powder and black charcoal powder (central particle size 5 μm) as aggregates, the paint can be given sufficient conductivity.

[0118] As a result, by applying a negative voltage to the paint 4 via the negative voltage generator 5, the paint film can efficiently adsorb positive ions in the surrounding space, thereby providing an antioxidant space.

[0119] Furthermore, the electrical properties derived from carbon materials improve the responsiveness of titanium dioxide to visible light, promoting its photocatalytic action and increasing the amount of radicals generated. As a result, the efficiency of removing harmful substances such as formaldehyde, bacteria, and mold by radicals can be enhanced.

[0120] Furthermore, the movement of free electrons based on the conductivity of carbon materials influences the movement of electrons in titanium dioxide, allowing titanium dioxide to be activated even in the absence of light, and enabling its powerful oxidizing ability to be utilized even in dark rooms.

[0121] Furthermore, by combining 5000-mesh white charcoal powder (central particle size 1 μm) with a mixture of 3000-mesh white charcoal powder and black charcoal powder (central particle size 5 μm), the specific surface area of ​​the carbon material can be increased, improving the adsorption efficiency of odors, chemical substances, moisture, etc. In particular, the adsorption efficiency for formaldehyde can be enhanced.

[0122] Furthermore, by increasing the adsorption efficiency of harmful substances such as formaldehyde onto the coating film, the photocatalytic effect of titanium dioxide becomes more readily apparent, further enhancing the efficiency of harmful substance removal.

[0123] Furthermore, regarding titanium dioxide in paints, applying a negative voltage increases the oxygen vacancies on the titanium dioxide surface, thereby improving its catalytic activity. Additionally, the surface charge of the titanium dioxide changes, activating it and increasing the reaction efficiency with harmful substances.

[0124] Furthermore, regarding titanium dioxide in paint, applying a negative voltage causes the titanium dioxide to act as a dielectric and be affected by an external electric field, changing the charge distribution within the titanium dioxide and activating its photocatalytic properties.

[0125] Furthermore, with respect to titanium dioxide in paint, the movement of water molecules is facilitated by a low-frequency electric field, accelerating the water splitting reaction on the surface of the titanium dioxide. This improves the efficiency of hydrogen generation and increases the amount of radicals generated.

[0126] As described above, the aqueous coating composition, air purification mechanism, and air purification method to which the present invention is applied are capable of forming a coating film of excellent quality and can exert sufficient air purification function in indoor spaces. [Examples]

[0127] The following describes embodiments of the present invention.

[0128] Samples of paints to which the present invention was applied were prepared, and the following evaluations were performed.

[0129] (1) Raw material components of the sample First, the paint was manufactured by adding raw material components to achieve the composition shown in Tables 1 to 3, and then the specified amount (300 g / m²) was applied to a test specimen substrate (100 mm x 100 mm, made of polypropylene). 3 Each sample of the above was applied and dried for 7 days to create test pieces, which were then used to prepare samples for Examples 1-3 and Comparative Examples 1-9. The values ​​for each component in the "Test Formulations" shown in Tables 1 to 10, including the contents of the tables described later, represent the amount of the target raw material in parts by weight (for example, the white charcoal powder (central particle size 1 μm) in Table 1 represents 66.7 parts by weight). Furthermore, each paint shown in Tables 1 to 3 has a composition that assumes application to a base material by hand using a roll or the like, and the viscosity has been adjusted by adding water separately in addition to the water contained in the acrylic resin that acts as a binder.

[0130] (2) Evaluation of the conductivity of the coating surface For each sample shown in Tables 1 to 3, the probe of a tester (surface resistance meter) was brought into contact with the coating surface of the test piece, and the electrical resistance value (unit: kΩ) at the coating surface was measured. In addition, for each sample, the resistance value was measured at 10 points on its surface, and the average of these 10 points was taken as the resistance value of that sample. The measurement results are also shown in Tables 1 to 3.

[0131] (Table 1) JPEG0007836540000002.jpg25169

[0132] (Table 2) JPEG0007836540000003.jpg26169

[0133] (Table 3) JPEG0007836540000004.jpg22169

[0134] As shown in Tables 1 to 3, in terms of the conductivity of the coating film surface, Examples 1 to 3 all showed lower resistance values ​​compared to Comparative Examples 1 to 9, indicating good conductivity on the coating film surface. Furthermore, Example 3 showed the best conductivity.

[0135] (3) Raw material components of the sample The paint was manufactured by adding raw material components to achieve the composition shown in Table 4, and 300 g / m² was applied to the substrate that would serve as the test piece. 2 Samples for Examples 1-3 and Comparative Example 4 were prepared by applying the coating amount specified. The coatings shown in Table 4 have compositions that are intended for application to a substrate by hand using a roll or the like, and their viscosity is adjusted by adding water separately in addition to the water contained in the acrylic resin that acts as a binder. Examples 1-3 and Comparative Example 4 are the same samples as those used in the evaluation of the conductivity of the coating film surface described in (2) above.

[0136] (4) Evaluation of the dispersibility of titanium dioxide For each sample shown in Table 4, characteristic X-rays were detected using a scanning electron microscope (SEM) and an energy-dispersive X-ray analyzer (EDS) in combination to measure the titanium concentration (Ti concentration) on the coating surface and evaluate the dispersibility of titanium dioxide in each sample. Furthermore, the Ti concentration was measured at three locations on the surface of each sample, and the average value of these three locations is shown in Table 4 as the surface Ti concentration (%) for that sample. Note that a higher surface Ti concentration (%) value in Table 4 indicates better dispersion of titanium dioxide in the coating.

[0137] (Table 4) JPEG0007836540000005.jpg26169

[0138] In terms of surface Ti concentration on the coating film surface, Examples 1 to 3 all showed higher surface Ti concentrations compared to Comparative Example 9. In particular, Example 3 produced a paint by mixing white charcoal powder with sodium polycarboxylate and a mixture of white charcoal powder and black charcoal powder, and then mixing titanium dioxide with sodium polyacrylate. This resulted in the highest surface Ti concentration, and the titanium dioxide was efficiently localized on the coating film surface by effectively dispersing it.

[0139] (5) Raw material components of the sample The paint was manufactured by adding raw material components to achieve the composition shown in Tables 5 and 6, and then applied to a test piece of wood at a rate of 300 g / m². 2 Samples 1-4 were prepared by applying the specified amount. Sample 4 was prepared to confirm whether titanium dioxide alone has the ability to adsorb formaldehyde.

[0140] (6) Evaluation of adsorption capacity for formaldehyde For each sample shown in Tables 5 and 6, after coating and drying the paint, the sample was brought into contact with the target gas (formaldehyde) in a test container for 30 minutes, and the initial adsorption (%) to formaldehyde was measured to evaluate the adsorption capacity. The substrate was then coated with a specified amount (300 g / m²). 3Each sample was applied to a sample and dried for 7 days to prepare a test specimen. A 4L glass container was filled with formaldehyde gas, and the test specimen was placed inside the container. The gas concentration in the container was measured after 30 minutes. The gas concentration was measured using a gas detector and gas detection tube manufactured by Gastec Co., Ltd. Adsorption was expressed as the reduction rate (%) before and after placing the test specimen in the container. Measurements were taken three times for each sample under a temperature of 25°C ± 2, and the average of the three measurements was used as the measurement result. Table 5 shows the results of tests conducted in an environment where the sample was irradiated with light (with a light source), and Table 6 shows the results of tests conducted with the sample placed in a light-shielded environment (without a light source).

[0141] (Table 5) JPEG0007836540000006.jpg19169

[0142] (Table 6) JPEG0007836540000007.jpg19169

[0143] In Test Examples 2 and 4, which contained neither white charcoal powder nor a mixture of white charcoal powder and black charcoal powder (no carbon material) but did contain titanium dioxide, the reduction rate of formaldehyde was low. On the other hand, in Test Examples 1 and 3, which contained both white charcoal powder and titanium dioxide, more than 80% of formaldehyde was reduced, demonstrating high adsorption capacity. Furthermore, when comparing the samples with and without a light source, Test Example 1, with a light source, showed higher adsorption capacity than Test Example 3, without a light source.

[0144] (7) Raw material components of the sample The paint was manufactured by adding raw material components to achieve the composition shown in Tables 7 and 8, and 300 g / m² was applied to the substrate that would serve as the test piece. 2 Samples for Examples 1-3 and Comparative Examples 9-11 were prepared by applying the coating in the specified amounts. Note that Examples 1-3 and Comparative Example 9 are the same samples used for the evaluation of the conductivity of the coating surface described in (2) above.

[0145] (8) Evaluation of adsorption capacity for formaldehyde For each sample shown in Tables 7 and 8, the adsorption capacity for formaldehyde was evaluated in the same manner as described in (6) Evaluation of formaldehyde adsorption capacity above. Tables 7 and 8 show the results of tests conducted in an environment where the sample was irradiated with light (with a light source) and tests conducted with the sample placed in a light-shielded environment (without a light source). For each sample shown in Table 8, a negative voltage of -125V was applied by connecting a negative voltage generator to each sample and placing it in a glass container filled with formaldehyde, and the gas concentration in the container was measured after 30 minutes.

[0146] (Table 7) JPEG0007836540000008.jpg32170

[0147] (Table 8) JPEG0007836540000009.jpg33168

[0148] As shown in Tables 7 and 8, Examples 1-3 all showed a larger reduction rate of formaldehyde compared to Comparative Examples 9-11, demonstrating good adsorption capacity for formaldehyde. Furthermore, Examples 2 and 3 showed a reduction of over 80% of formaldehyde, indicating high adsorption capacity. In addition, Example 3 showed the highest adsorption capacity. Moreover, for all samples, the adsorption capacity was higher with a light source than without.

[0149] Furthermore, as shown in Tables 7 and 8, Examples 1-3 (see Table 8), in which a negative voltage of -125V was applied, showed a reduction in formaldehyde and higher adsorption capacity compared to Examples 1-3 (see Table 7), in which no negative voltage was applied.

[0150] (9) Raw material components of the sample The paint was manufactured by adding raw material components to achieve the compositions shown in Tables 9 and 10, and then applied to the nonwoven fabric at a rate of 300 g / m². 2Samples for Examples 1-3 and Comparative Examples 9-11 were prepared by applying the specified coating amounts. As a control for the test, a nonwoven fabric was prepared after being sterilized in an autoclave (120°C, 20 minutes). Examples 1-3 and Comparative Example 9 are the same samples as those used in the evaluation of the conductivity of the coating surface described in (2) above, and Comparative Examples 10 and 11 are the same samples as those used in the evaluation of the adsorption capacity for formaldehyde described in (8) above.

[0151] (10) Evaluation of mold inhibition test Mold inhibition tests were performed on each of the samples shown in Tables 9 and 10 according to the following procedure. (a) In order to increase the amount of airborne bacteria (mold, bacteria), the chamber was made into a high-temperature, high-humidity environment, and a planter containing soil for vegetation was placed inside as a source of bacterial growth. (b) A small fan was operated inside the chamber to circulate the air within the chamber. (c) After preparing each sample and control, they were left to stand in the chamber to create an environment conducive to mold growth, with a temperature of 30°C and a humidity of 90-100%. (d) After two weeks, each sample and control was removed, and PDA medium for fungal count measurement (Eiken Chemical Co., Ltd.: Petan Check 25) was lightly pressed onto the painted surface of each sample. (e) After another two weeks, the number of colonies expressed on the PDA medium was counted. The results shown in Tables 9 and 10 represent the number of colonies counted on PDA culture medium. Tables 9 and 10 also show the results of tests conducted under conditions where the sample was irradiated with light (with a light source) and tests conducted with the sample in a light-shielded environment (without a light source). Furthermore, for each sample shown in Table 10, a negative voltage of -125V was applied within the chamber by connecting a negative voltage generator to each sample.

[0152] (Table 9) JPEG0007836540000010.jpg32169

[0153] (Table 10) JPEG0007836540000011.jpg34169

[0154] As shown in Tables 9 and 10, Examples 1-3 all had fewer colonies on the PDA medium compared to Comparative Examples 9-11, and Examples 1-3 showed superior mold inhibition compared to Comparative Examples 9-11. Example 3 exhibited the highest mold inhibition effect. Furthermore, regarding the presence or absence of a light source, all samples except Example 2 (shown in Table 10) showed higher adsorption capacity with a light source than without.

[0155] Furthermore, as shown in Tables 7 and 8, Examples 1-3 (see Table 10), in which a negative voltage of -125V was applied, had fewer colonies compared to Examples 1-3 (see Table 9), demonstrating a higher mold suppression effect. [Explanation of Symbols]

[0156] 1 Wall surface 11 Wall surface 11a Substrate 2 Ceiling surface 3 Indoor space 4 Paint 5. Negative Voltage Generator 51 Positive electrode 52 Negative electrode 53 Earth 54 Power supply 6. Insulating layer 7 Finishing materials

Claims

1. A binder made of synthetic resin, A first carbon material is a powder with a central particle size of 1 μm, A second carbon material, which is a powder with a central particle size of 5 μm, Titanium oxide and Dispersant and Water and contains Water-based paint composition.

2. The carbon material comprising the first carbon material and the second carbon material is blended with titanium oxide in an amount of 0.5 to 1.0 parts by weight. The aqueous paint composition according to claim 1.

3. The second carbon material is blended in a range of 20 to 100 parts by weight with 100 parts by weight of the first carbon material. The aqueous paint composition according to claim 1 or claim 2.

4. The dispersant comprises a first dispersant consisting of sodium polycarboxylate and a second dispersant consisting of sodium polyacrylate. The aqueous paint composition according to claim 1 or claim 2.

5. The carbon material comprising the first carbon material and the second carbon material is blended in an amount of 1.0 part by weight of the first dispersant, The second dispersant is blended in an amount of 100 parts by weight with respect to 100 parts by weight of the titanium oxide. The aqueous paint composition according to claim 4.

6. An air purification mechanism that charges a coated surface coated with a conductive aqueous paint composition with a negative voltage using a negative voltage generating means, The aqueous paint composition contains a binder made of synthetic resin, a first carbon material which is a powder with a central particle size of 1 μm, a second carbon material which is a powder with a central particle size of 5 μm, titanium dioxide, a dispersant, and water. Air purification mechanism.

7. The amount of the aqueous coating composition applied to the coated surface is 100 to 300 g / m². ２ - Within the wet range The air purification mechanism according to claim 6.

8. The generated voltage on the coating surface, which has been charged with a negative voltage by the negative voltage generating means, is within the range of -50 to -150V. The air purification mechanism according to claim 6 or claim 7.

9. A step of applying a conductive aqueous coating composition containing a binder made of synthetic resin, a first carbon material which is a powder with a central particle size of 1 μm, a second carbon material which is a powder with a central particle size of 5 μm, titanium dioxide, a dispersant, and water to at least one surface of a plurality of wall or ceiling surfaces constituting an interior space. The process includes a step of charging the coated surface to which the aqueous paint composition has been applied with a negative voltage. Air purification methods.

10. The first carbon material and the second carbon material are materials fired at different temperatures. The first carbon material is fired at a temperature of 1,000°C or higher. The second carbon material was fired at a temperature of 600°C or higher. The air purification method according to claim 9.

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