Defoamer composition, water-based coating composition and articles having a coat film formed by a defoamer composition-containing coating agent

Abstract

This invention provides a defoamer composition capable of forming a coating film with excellent coating appearance and excellent shear resistance, and which does not hinder coating properties; an aqueous coating composition containing the defoamer composition; and an article obtained by coating with a coating agent containing the defoamer composition. The defoamer composition for aqueous coatings comprises: a nonionic surfactant (A) having at least one hydrophilic portion selected from the group consisting of ethylene glycol, polyethylene glycol, and polyol portions, and having an HLB of 1 to 16; a polymer (B) lacking the hydrophilic portion, having a solubility parameter of 7.5 to 12, and a weight average molecular weight of 400 to 1,000,000; and organic solid particles (C) in a solid state in the defoamer composition at 25°C.

Description

Defoaming agent composition, water-based paint composition and articles The invention relates to a defoamer composition, a water-based coating composition and an article. In recent years, the emphasis on coating appearance has been increasing in the field of water-based paints. Air bubbles remaining in the coating film during painting can severely degrade the appearance of the coating. Consequently, the performance requirements for defoamers added to paints have also increased in line with this recent emphasis on coating appearance. Here, as a defoaming agent that can also be used for applications requiring a high appearance, for example, the defoaming agent described in Patent Document 1 has been proposed. Furthermore, as defoaming agents with excellent defoaming effects, silicone-type defoaming agents (for example, see Patent Document 2) and composite defoaming agents (for example, see Patent Document 3) can be cited. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent No. 4526584 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-212403 [Patent Document 3] Japanese Patent Publication No. 01-6803 [Problems to be solved by the invention] Generally speaking, silicone-type defoamers have excellent bubble breaking properties due to their extremely low surface tension. On the other hand, due to the leakage of silicone components to the surface of the coating film, it becomes the main cause of shrinkage holes or hinders the coating properties. Even if these adverse effects are not confirmed in the short term in laboratory-scale experiments or actual coating steps, a single failure in mass production may also cause large losses. Therefore, especially in coatings for applications that value high appearance, or coating systems formed by multi-layer coatings, production line coating and other large-scale coating systems, the formulation of silicone-based materials itself is mostly avoided, and the use of silicone-type defoamers is also avoided as defoamers. On the other hand, composite defoamers contain microparticles with a hydrophobic surface. Due to the high defoaming properties caused by the hydrophobic surface, they are mostly used in anticipation of excellent defoaming effects. Furthermore, recent water-based paints often utilize ingredients that are difficult to disperse in water to enhance their functionality. Failure to fully micronize or disperse these ingredients can negatively impact the finished product's appearance. Consequently, recent efforts have focused on extending the dispersion process and increasing the shear force applied to the paint during the dispersion process (high shear). However, the composite defoamers described in Patent Document 3 and Patent Document 1 may lose their defoaming properties during long-term dispersion or high-shear dispersion steps. Therefore, there is a need for a defoamer that exhibits resistance to defoaming due to shear forces applied to the coating (hereinafter referred to as "shear resistance"). Furthermore, coatings are sometimes recycled to prevent sedimentation and separation of components within the coating, and in these cases, long-term shear resistance is required. Furthermore, the presence of fine particles in the composite defoamer may impair the smoothness and gloss of the coating film. Therefore, the present invention has been made in view of the above circumstances, and its object is to provide a defoamer composition capable of forming a coating film having an excellent painted appearance and excellent shear resistance without impairing coating properties, a water-based coating composition containing the defoamer composition, and an article coated with a coating agent containing the defoamer composition. [Means for Solving the Problem] The present inventors have diligently researched to address the aforementioned issues and have discovered that by adding a nonionic surfactant having a hydrophilic portion with a specific structure and a hydrophilic-lipophilic balance (HLB) within a specific range, a polymer having a solubility parameter (SP) value and a weight-average molecular weight within a specific range, and organic solid fine particles as components of a defoamer composition, they have found that a defoamer composition for water-based coatings can be provided that forms a coating film with excellent painted appearance, exhibits excellent shear resistance, and does not impair coatability. This finding has led to the completion of the present invention. That is, the present invention is a defoamer composition for use in water-based coatings, characterized by comprising a nonionic surfactant (A), a polymer (B), and organic solid particles (C). The nonionic surfactant (A) has at least one hydrophilic portion selected from the group consisting of an ethylene glycol portion, a polyethylene glycol portion, and a polyol portion in its molecule, and has an HLB of 1 to 16. The polymer (B) does not have the hydrophilic portion in its molecule, has an SP value of 7.5 to 12, and a weight-average molecular weight of 400 to 1,000,000. The organic solid particles (C) are in a solid state in the defoamer composition at 25°C. In one aspect of the present invention, the nonionic surfactant (A) may be one or more selected from the group consisting of ethylene glycol aliphatic ethers, polyoxyalkylene aliphatic ethers, polyoxyalkylene aromatic ethers, polyoxyalkylene fatty acid esters, alkylene oxide addition derivatives of castor oil, alkylene oxide addition derivatives of hydrogenated castor oil, polyoxyalkylene polyol ethers, polyol fatty acid esters, alkylene oxide addition derivatives of polyol fatty acid esters, polyoxyalkylene alkylamides, acetylene glycol and its derivatives, alkylene oxide addition derivatives of acetylene glycol, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers. In another aspect of the present invention, the polymer (B) may be one or more polymers selected from the group consisting of polyvinyl alkyl ether, polybutadiene, polybutylene, polyisoprene, poly-α-olefin, polyalkyl (meth)acrylate, copolymers of dibasic acid esters, polyvinyl fatty acid esters, copolymers of alkyl (meth)acrylate and vinyl fatty acid ester, and polyalkylene glycol derivatives (wherein the polyalkylene glycol derivative does not have the ethylene glycol moiety, the polyethylene glycol moiety, and the polyol moiety, and the weight average molecular weight of the polyalkylene glycol derivative is 400 to 1,000,000). In another aspect of the present invention, the organic solid particles (C) may be one or more solid particles selected from the group consisting of amide, urea, polyethylene, oxidized polyethylene, acid-modified polyethylene, and hydrogenated castor oil. In this case, the amide is preferably a fatty acid diamide obtained by reacting a fatty acid with a diamine, wherein the fatty acid is selected from the group consisting of an alkyl fatty acid and a hydroxy fatty acid and includes at least one hydroxy fatty acid, and the diamine includes one or more diamines selected from the group consisting of an alkylenediamine having 2 to 6 carbon atoms and m-xylenediamine. In another aspect of the present invention, the aspect ratio of the crystals of the organic solid particles (C) is preferably 1.1-100. In another aspect of the present invention, the defoamer composition may further include an organic medium (D) other than water that does not have the hydrophilic portion in its molecule and is liquid at 25° C., wherein the weight average molecular weight of the organic medium (D) is less than 400. In this case, the organic medium (D) may be one or more selected from the group consisting of hydrocarbon oils, alcohols, glycol ethers, and glycol esters. In another aspect of the present invention, the defoamer composition preferably does not contain a silicone compound. Furthermore, the present invention provides a water-based coating composition, characterized by comprising the defoamer composition and a water-based resin. Furthermore, the present invention is an article coated with a coating agent containing the defoaming agent composition. [Effects of the Invention] According to the present invention, a defoamer composition comprising a specific nonionic surfactant, a polymer, and organic solid fine particles as defoamer components can be provided, which can form a coating film having an excellent painted appearance, has excellent shear resistance, and does not impair external coating properties; a water-based coating composition comprising the defoamer composition; and an article coated with a coating agent comprising the defoamer composition. Hereinafter, preferred embodiments of the present invention will be described in detail. [Defoamer Composition] The defoamer composition of the present invention is an additive for suppressing the generation of bubbles caused by the presence of multiple surfactants in water-based paints. It contains as essential ingredients: a nonionic surfactant (A) having a hydrophilic portion of a specific structure and an HLB within a specific range; a polymer (B) having an SP value and a weight-average molecular weight within a specific range; and organic solid fine particles (C). Thus, the present invention provides a defoamer composition for water-based paints that forms a coating film with an excellent finished appearance, exhibits excellent shear resistance, and does not impair external coating properties. Here, the "defoaming property" in the present invention refers to the property of eliminating bubbles generated in water-based paint. As mentioned above, the "shear resistance" in the present invention refers to the resistance to the deactivation of the defoaming property accompanied by the application of shear force to the paint, in other words, it refers to the property of suppressing the defoaming agent from losing its defoaming property when shear force is applied to the paint. In addition, the "overcoatability" in the present invention refers to the property of being able to apply paint (hereinafter referred to as "overcoat") to the surface of an already applied coating film (hereinafter referred to as "primer coating film") in a coating system composed of multiple layers, showing either or both of the following: the property of being able to apply paint without generating shrinkage cavities, etc., and the property of not generating peeling problems between the overcoat coating film and the primer coating film. Furthermore, the overcoatability is generally evaluated by preparing a multilayer coating film and conducting a test of the adhesion of the overcoat coating film to the primer coating film, but it can be evaluated by simply measuring the contact angle of the primer coating film surface. When evaluating contact angle, in a topcoat or water-based coating, a co-solvent (an organic solvent blended into the coating), water containing a co-solvent, or water alone is used as the contact angle evaluation liquid. The lower the contact angle of a droplet of the contact angle evaluation liquid dropped onto the primer coating, the better the evaluation of topcoatability. These essential components and optional components contained in the defoamer composition of the present invention are described in detail below. (Nonionic Surfactant (A)) The nonionic surfactant (A) of the present invention is a component that exerts defoaming properties and is added to improve the defoaming agent's permeability into the foam film. Furthermore, the nonionic surfactant (A) also functions as a stabilizer, ensuring that defoaming droplets containing organic solid particles (C), or the organic solid particles (C) themselves, are stably present in the aqueous coating. A surfactant is an organic functional agent that has the property of reducing the surface tension of a liquid. For example, hydrogenated castor oil (hardened castor oil), a triglyceride of fatty acids, is not a surfactant and is therefore not included in the nonionic surfactant (A). As the nonionic surfactant (A) of the present invention, a nonionic surfactant having at least one hydrophilic portion selected from the group consisting of an ethylene glycol portion, a polyethylene glycol portion, and a polyol portion in its molecule and having an HLB of 1 to 16 is used. The "hydrophilic part" is defined as one or more parts selected from the group consisting of ethylene glycol part, polyethylene glycol part, and polyol part in the molecule of nonionic surfactant (A). The ethylene glycol part is composed of -CH 2CH 2O- represents an oxyethylene group. The polyethylene glycol portion is composed of -(CH 2CH 2O) n -(n≧2) represents a polyoxyethylene group. The polyol moiety refers to a portion of the molecular structure derived from an organic group having two or more hydroxyl groups, when the nonionic surfactant (A) is a derivative of a divalent or higher alcohol, obtained by removing monovalent substituents and acyl groups consisting solely of hydrocarbons having 1 or more carbon atoms, and is not equivalent to an alkanediol or polyalkylene glycol. Furthermore, when the "hydrophilic portion" is composed solely of ethylene glycol or diethylene glycol, the number of carbon atoms in the hydrophobic portion (the portion of the nonionic surfactant (A) molecule other than the "hydrophilic portion") is limited to 9 or more. If the HLB value of the nonionic surfactant (A) is less than 1, its compatibility with water may be poor, potentially leading to problems such as the nonionic surfactant component itself separating in the water-based paint. On the other hand, if the HLB value of the nonionic surfactant (A) exceeds 16, its affinity for water is too high, making it unable to fully stabilize the other components of the defoamer, potentially leading to problems such as the formation of aggregates and the separation of other defoaming components in the water-based paint. The mechanism of action of defoamers is known to involve droplets of defoamer lacking affinity for aqueous media invading the interior of the bubble membrane. These droplets penetrate the membrane, causing the bubble to break, originating from the droplets. This suggests that highly hydrophobic substances, i.e., those with low HLB values, are potentially superior in bubble breaking properties. On the other hand, defoamer droplets must be large enough to penetrate the bubble membrane. This requires a certain degree of hydrophilicity; the higher the hydrophilicity, the greater the dispersibility in water, resulting in smaller droplets. Conversely, low hydrophilicity results in larger droplets. If the droplet diameter is too small, it will not penetrate the bubble membrane; if it is too large, it will not penetrate the bubble membrane; in either case, the defoaming function will not be achieved. Therefore, there is an appropriate HLB range to control the droplet diameter. When the nonionic surfactant (A) is within an appropriate HLB range, it has defoaming properties, which is more preferable. From this point of view, the HLB of the nonionic surfactant (A) is preferably 2 to 16, and more preferably 3 to 16. The nonionic surfactant (A) also functions to homogenize the polymer (B), organic solid particles (C), and organic medium (D), which are other components of the defoamer composition of the present invention, within the defoamer composition. Furthermore, the nonionic surfactant (A) contributes to the defoaming function by controlling the droplets of the mixed components to an appropriate particle size for functioning as a defoamer and stabilizing their dispersion in the water-based coating. The HLB in the present invention is determined by the following formula based on the Griffin method: HLB = 20 × total formula weight of the hydrophilic part / molecular weight The hydrophilic portion of the above formula is defined as above. <Specific Example> The nonionic surfactant (A) of the present invention is a nonionic surfactant having the aforementioned hydrophilic portion and an HLB value within the aforementioned range. The nonionic surfactant is selected to be in a liquid state in the liquid medium contained in the composition at 25°C and not in a solid state (i.e., not present as fine particles in the defoamer composition). Examples of methods for determining whether a compound having the aforementioned hydrophilic portion and an HLB value within the aforementioned range, contained in the defoamer composition of the present invention, corresponds to the nonionic surfactant (A) of the present invention include the following method. For example, the compound is dispersed in a mixed solution of the liquid medium component contained in the defoamer composition, excluding the compound to be identified, so that the content of the compound to be identified does not exceed 50% by mass. The dispersion is then filtered and then thoroughly washed with the mixed solution. If no filtration residue is obtained, the compound to be identified can be determined to be the nonionic surfactant (A). On the other hand, when a filtration residue is obtained after the filtration and washing, it can be determined by performing qualitative analysis that the compound to be identified is not contained. This allows identification that the compound to be identified is the nonionic surfactant (A). As the nonionic surfactant (A), for example, one or more of ethylene glycol aliphatic ethers, polyoxyalkylene aliphatic ethers, polyoxyalkylene aromatic ethers, polyoxyalkylene fatty acid esters, alkylene oxide addition derivatives of castor oil, alkylene oxide addition derivatives of hydrogenated castor oil, polyoxyalkylene polyol ethers, polyol fatty acid esters, alkylene oxide addition derivatives of polyol fatty acid esters, polyoxyalkylene alkylamides, acetylene glycol and its derivatives, alkylene oxide addition derivatives of acetylene glycol, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers can be used. As the ethylene glycol aliphatic ether, for example, one in which an aliphatic chain having 9 to 22 carbon atoms is bonded to ethylene glycol via an ether bond can be used. Examples of the polyoxyalkylene aliphatic ethers include polyoxyethylene aliphatic ethers and polyoxyethylene-polyoxypropylene aliphatic ethers having 1 to 22 carbon atoms. Examples of the polyoxyalkylene aromatic ethers include polyoxyethylene aromatic ethers and polyoxyethylene-polyoxypropylene aromatic ethers having 6 to 28 carbon atoms. Examples of the polyoxyalkylene fatty acid esters include polyoxyethylene fatty acid esters and polyoxyethylene-polyoxypropylene fatty acid esters having 1 to 22 carbon atoms. Examples of the alkylene oxide addition derivatives of castor oil or hydrogenated castor oil that can be used include polyoxyalkylene castor oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene-polyoxypropylene castor oil ether; polyoxyalkylene hydrogenated castor oil ethers such as polyoxyethylene hydrogenated castor oil ether and polyoxyethylene-polyoxypropylene hydrogenated castor oil ether; polyoxyalkylene castor oil ether fatty acid esters such as polyoxyethylene castor oil ether fatty acid esters and polyoxyethylene-polyoxypropylene castor oil ether fatty acid esters; polyoxyethylene hydrogenated castor oil ether fatty acid esters (e.g., polyoxyethylene hydrogenated castor oil monoisostearate and polyoxyethylene hydrogenated castor oil triisostearate), and polyoxyalkylene hydrogenated castor oil ether fatty acid esters such as polyoxyethylene-polyoxypropylene hydrogenated castor oil ether fatty acid esters. Here, for example, when using an ethylene oxide adduct of castor oil or hydrogenated castor oil, the molar amount of ethylene oxide (EO) added to the castor oil or hydrogenated castor oil is preferably 5 mol to 100 mol, more preferably 5 mol to 60 mol. By adjusting the molar amount of EO added to this range, the defoaming properties and shear resistance of the defoaming agent of the present invention can be improved. Examples of the polyoxyalkylene polyol ethers include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to polyols such as glycerol, polyglycerol, trimethylolpropane, pentaerythritol, monosaccharides, disaccharides, trisaccharides, oligosaccharides, polysaccharides, sorbitol, and sorbitan, which have a glucose or fructose backbone. Examples of the polyol fatty acid esters include esters of polyols such as glycerol, polyglycerol, trimethylolpropane, pentaerythritol, monosaccharides, disaccharides, trisaccharides, oligosaccharides, polysaccharides, sorbitol, and sorbitan, which have a glucose or fructose backbone, and fatty acids such as acetic acid, propionic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, 12-hydroxystearic acid, linoleic acid, linolenic acid, behenic acid, and erucic acid. Examples of polyol fatty acid ester alkylene oxide addition derivatives include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to the polyol fatty acid esters. Examples of polyoxyalkylene alkylamides include polyoxyethylene stearamide and polyoxyethylene oleamide. As acetylene glycol and its derivatives, and alkylene oxide-added derivatives of acetylene glycol, commercially available products can be used, for example, Surfynol (registered trademark: product name of Nissin Chemical Industry Co., Ltd.) series, Acetylenol (registered trademark: product name of Kawake Fine Chemical Co., Ltd.) series, etc. The number of moles of ethylene oxide (EO) added to acetylene glycol or an acetylene glycol derivative is preferably 1 to 10 mol. From the perspective of improving the defoaming properties of the defoaming agent of the present invention, the number of moles of EO added is more preferably 1 to 4 mol. As polyoxyethylene-polyoxypropylene block copolymers or polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers, for example, those having a total ethylene oxide block content of 10% to 50% by mass, more preferably 10% to 20% by mass, and a propylene oxide block weight average molecular weight of 700 to 4000, more preferably 3000 to 4000, within these ranges can be used. Liquid block copolymers are particularly preferred. In the specific examples described above, in order to improve the defoaming property, polyoxyethylene hydrogenated castor oil, polyoxyethylene triisostearate hydrogenated castor oil, or the like is preferably used. <Content> The content of the nonionic surfactant (A) is preferably 5% to 80% by mass, based on the total mass of all components in the defoamer composition being 100% by mass. A content of 5% to 80% by mass of the nonionic surfactant (A) can achieve sufficient defoaming properties. To further enhance the defoaming effect, the content of the nonionic surfactant (A) is preferably 10% to 50% by mass. (Polymer (B)) The polymer (B) of the present invention is a component that contributes to defoaming properties and is added to improve the permeability of the defoaming agent into the foam membrane. Polymers (B) with an SP value of 7.5 to 12 and a weight-average molecular weight of 400 to 1,000,000 are used. Furthermore, polymers (B) that do not have a hydrophilic portion (ethylene glycol, polyethylene glycol, or polyol) in their molecules and are in a liquid or rubbery form are selected. Alternatively, polymers that are solid at 25°C but are liquid in the liquid medium contained in the composition at 25°C and do not exist in a solid state (i.e., do not exist as fine particles in the defoaming agent composition) are selected. Liquid polymers can be used alone, while rubbery or solid polymers can be dissolved in a liquid component before use. <SP Value / Weight Average Molecular Weight> The SP value of the polymer (B) of the present invention is in the range of 7.5 to 12. If the SP value is less than 7.5, defects in the coating appearance, such as craters and grains, may occur. On the other hand, if the SP value exceeds 12, the defoaming effect is insufficient, and satisfactory defoaming properties may not be achieved. Furthermore, to further improve defoaming properties, the SP value is preferably 7.5 to 11, more preferably 8.0 to 9.5, and even more preferably 8.0 to 9.0. The SP value in the present invention is a value calculated by the Fedors method, and the unit is (cal / cm 3 ) 1 / 2 The Fedors method is a method for calculating the SP value based on the molecular structure. It can be calculated based on the cohesive energy (cal / mol) of each atomic group and the molar molecular volume (cm 3 The SP value was calculated based on the relationship between mol and mol. The weight-average molecular weight of the polymer (B) of the present invention is in the range of 400 to 1,000,000. If the weight-average molecular weight is less than 400, sufficient defoaming properties may not be achieved. On the other hand, if the weight-average molecular weight exceeds 1,000,000, uniform dispersion of the polymer (B) in the coating may be difficult, leading to problems such as craters and craters. Furthermore, to further enhance defoaming properties, the weight-average molecular weight is preferably 400 to 300,000. The weight average molecular weight in the present invention is a value calculated from a chromatogram measured by gel permeation chromatography (GPC) using the molecular weight of standard polystyrene as a standard. <Specific Example> The polymer (B) of the present invention has the aforementioned SP value and weight-average molecular weight, and does not contain an ethylene glycol moiety, a polyethylene glycol moiety, or the aforementioned polyol moiety. Here, "polymer (B)" in the present invention refers to a compound having a repeating monomer unit and a degree of polymerization of 3 or greater, or a derivative thereof. Preferred examples of polymer (B) include one or more of the following: polyvinyl alkyl ether, polybutadiene, polybutene, polyisoprene, poly-α-olefin, polyalkyl (meth)acrylate, copolymers of dibasic acid esters, polyvinyl fatty acid esters, copolymers of alkyl (meth)acrylates and vinyl fatty acid esters, and polyalkylene glycol derivatives (wherein the polyalkylene glycol derivatives do not contain the aforementioned ethylene glycol moiety, polyethylene glycol moiety, or polyol moiety, and have a weight-average molecular weight of 400 to 1,000,000). The polyvinyl alkyl ether is obtained by polymerizing a vinyl ether monomer having an alkyl group with 1 to 18 carbon atoms. Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, isononyl vinyl ether, dodecyl vinyl ether, tetradecyl vinyl ether, hexadecyl vinyl ether, and octadecyl vinyl ether. One or more of these monomers may be arbitrarily selected for use. Polyvinyl alkyl ethers can be obtained by polymerizing the aforementioned monomers using a cationic polymerization method. The weight-average molecular weight of the polyvinyl alkyl ether is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. A weight-average molecular weight of less than 1,000 may result in insufficient defoaming performance. A weight-average molecular weight exceeding 500,000 may make it difficult to evenly disperse in the coating, potentially leading to problems such as craters and dents. As polybutadiene, 1,3-butadiene (CH 2=CH-CH=CH 2), or 1,2-butadiene (CH 2=C=CH-CH 3) Homopolymers and copolymers. Commercially available polybutadiene can also be used. Commercially available polybutadiene includes homopolymers, hydrogenated types, carboxylic acid-terminated types, and hydroxyl-terminated types. Examples of homopolymers include B-1000 (15mer to 25mer: number average molecular weight of approximately 1000), B-2000 (30mer to 40mer: number average molecular weight of approximately 2000), and B-3000 (45mer to 65mer: number average molecular weight of approximately 3000) (all manufactured by Nippon Soda Co., Ltd.). Examples of hydrogenated types include BI-2000 (30mer to 40mer: number average molecular weight of approximately 2000) and BI-3000 (45mer to 65mer: number average molecular weight of approximately 3000) (all manufactured by Nippon Soda Co., Ltd.). Examples of terminal carboxylic acid-type polymers include C-1000 (20-mer to 30-mer: number average molecular weight of approximately 1400) (manufactured by Nippon Soda Co., Ltd.). Examples of terminal hydroxyl-type polymers include G-1000 (20-mer to 30-mer: number average molecular weight of approximately 1500), G-2000 (30-mer to 40-mer: number average molecular weight of approximately 2000), and G-3000 (45-mer to 60-mer: number average molecular weight of approximately 2900) (all manufactured by Nippon Soda Co., Ltd.), poly(poly)bd R-15HT (20-mer to 25-mer: number average molecular weight of approximately 1200), and poly(poly)bd R-45HT (45-mer to 55-mer: number average molecular weight of approximately 2800) (all manufactured by Idemitsu Kosan Co., Ltd.). Any one or two or more of these polymers may be selected and used. The weight-average molecular weight of polybutadiene is preferably 2,000 to 300,000, more preferably 2,000 to 230,000, even more preferably 2,000 to 200,000, and most preferably 3,000 to 10,000. A weight-average molecular weight of less than 2,000 may not provide sufficient defoaming performance. A weight-average molecular weight exceeding 300,000 may make it difficult to disperse uniformly in the coating, potentially leading to problems such as craters, dents, and a sparse coating film. Furthermore, the SP value of polybutadiene is more preferably 7.5 to 9.0. As the polybutene, a homopolymer of 1-butene or a copolymer of 1-butene and isobutylene can be used. Alternatively, commercially available polybutene can be used. Commercially available polybutene includes copolymers of 1-butene and isobutylene, homopolymers of 1-butene, and hydrogenated types. Examples of copolymers of 1-butene and isobutylene include LV-7 (quadomer to hexamer: number average molecular weight of approximately 300), LV-50 (hexamer to nonamer: number average molecular weight of approximately 450), LV-100 (octamer to 12amer: number average molecular weight of approximately 500), HV-15 (nonamer to 13amer: number average molecular weight of approximately 630), HV-35 (decamer to 15amer: number average molecular weight of approximately 750), HV-50 (12amer to 16amer: number average molecular weight of approximately 800), HV-100 (16amer to 20amer: number average molecular weight of approximately 980), HV-300 (23mer to 27mer: number average molecular weight of approximately 1400), and HV-1900 (45mer to 55mer: number average molecular weight of approximately 2900) (all manufactured by ENEOS Co., Ltd.). Examples of 1-butene homopolymers include 15R (9-mer to 11-mer: number average molecular weight of approximately 570), 35R (12-mer to 14-mer: number average molecular weight of approximately 720), 100R (16-mer to 20-mer: number average molecular weight of approximately 960), and 300R (24-mer to 30-mer: number average molecular weight of approximately 1500) (all manufactured by Idemitsu Kosan Co., Ltd.). Examples of hydrogenated 1-butene homopolymers include 0H (5-mer to 7-mer: number average molecular weight of approximately 350), 5H (6-mer to 8-mer: number average molecular weight of approximately 400), 10H-T (7-mer to 10-mer: number average molecular weight of approximately 470), 300H (24-mer to 30-mer: number average molecular weight of approximately 1500), and 2000H (50-mer to 55-mer: number average molecular weight of approximately 3000) (all manufactured by Idemitsu Kosan Co., Ltd.). One or two or more kinds of these polymers may be arbitrarily selected and used. The weight-average molecular weight of polybutene is preferably 400-50,000, more preferably 400-20,000. A weight-average molecular weight of less than 400 may result in insufficient defoaming performance. A weight-average molecular weight exceeding 50,000 may make it difficult to disperse uniformly in the coating, potentially leading to problems such as craters, craters, and a sparse coating film. Furthermore, the SP value of polybutene is more preferably 7.5-9.0. Commercially available polyisoprene can be used. Commercially available polyisoprene includes hydroxyl-terminated and hydrogenated types. Examples of hydroxyl-terminated polyisoprene include polyiP (30-40mers: number average molecular weight approximately 2500) (manufactured by Idemitsu Kosan Co., Ltd.). Examples of hydrogenated polyisoprene include EPOL, a hydrogenated form of polyiP (manufactured by Idemitsu Kosan Co., Ltd.). One or more of these polymers can be selected for use. The weight-average molecular weight of polyisoprene is preferably 2,000 to 50,000, more preferably 3,000 to 20,000. A weight-average molecular weight of less than 2,000 may not provide sufficient defoaming performance. A weight-average molecular weight exceeding 50,000 may make it difficult to disperse uniformly in the coating, potentially leading to problems such as craters, craters, and a sparse coating film. Furthermore, the SP value of polyisoprene is more preferably 7.5 to 9.0. Examples of the poly-α-olefin include poly(1-hexene), poly(1-octene), poly(1-decene), poly(1-dodecene), and ethylene-propylene copolymers, and one or more of these may be arbitrarily selected and used. The weight average molecular weight of the polyα-olefin is preferably 400 to 100,000, more preferably 400 to 10,000, and even more preferably 500 to 5,000. A weight average molecular weight of less than 400 may not provide sufficient defoaming performance. A weight average molecular weight exceeding 100,000 may make it difficult to disperse uniformly in the coating, potentially leading to problems such as craters, dents, and a sparse coating film. Furthermore, the SP value of the polyα-olefin is more preferably 7.5 to 9.0. In addition, as the polymer (B) of the present invention, in addition to the above-mentioned polymers, for example, polyalkyl (meth)acrylates, copolymers of dibasic acid esters, polyvinyl fatty acid esters, copolymers of alkyl (meth)acrylates and vinyl fatty acid esters, and polyalkylene glycol derivatives (which do not have an ethylene glycol moiety, a polyethylene glycol moiety, or the above-mentioned polyol moiety and have a weight average molecular weight of 400 to 1,000,000) can also be used. Examples of the polyalkyl (meth)acrylate include polymers or copolymers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, oleyl (meth)acrylate, behenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate. Examples of copolymers of dibasic acid esters include polymers or copolymers of monoesters or diesters of maleic acid, and polymers or copolymers of monoesters or diesters of fumaric acid. Examples of polyvinyl fatty acid esters include polymers or copolymers of vinyl acetate, vinyl trimethylacetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl caprylate, vinyl decanoate, vinyl laurate, vinyl palmitate, vinyl octanoate, vinyl 2,2-dimethyloctanoate, vinyl neononanoate, vinyl neodecanoate, and vinyl neoundecanoate. Examples of copolymers of alkyl (meth)acrylates and vinyl fatty acid esters include copolymers comprising a combination of the aforementioned (meth)acrylates and the aforementioned vinyl fatty acid. Regarding polyalkyl (meth)acrylates, dibasic acid ester copolymers, polyvinyl fatty acid esters, and copolymers of alkyl (meth)acrylates and vinyl fatty acid esters, monomers other than the aforementioned monomers that do not contain an ethylene glycol moiety, a polyethylene glycol moiety, or a polyol moiety may be copolymerized within a range not exceeding 50 mol %, as long as defoaming properties or shear resistance are not impaired. Examples of polyalkylene glycol derivatives include polypropylene glycol, polybutylene glycol, polypropylene glycol monobutyl ether, polypropylene glycol monostearyl ether, and polypropylene glycol adducts and polybutylene glycol adducts added to polyols such as glycerol, trimethylolpropane, and sugars, which do not correspond to nonionic surfactants (A). Among the specific examples described above, polyvinyl alkyl ether, polybutadiene, polybutene, poly-α-olefin, and the like are preferably used in order to improve defoaming properties, coating appearance, shear resistance, and coating properties. <Content> The content of the polymer (B) is preferably 10% to 90% by mass, based on the total mass of all components in the defoamer composition being 100% by mass. A content of 10% to 90% by mass of the polymer (B) allows for sufficient defoaming performance. To further enhance the defoaming effect, the content of the polymer (B) is preferably 20% to 70% by mass. (Organic Solid Particles (C)) The organic solid particles (C) of the present invention are components that contribute to defoaming properties and are added to enhance the defoaming effect of the defoamer and improve the shear resistance of the coating. The organic solid particles (C) are selected from materials with a melting point of at least 50°C and are solid at 25°C. These organic solid particles (C) are solid in the liquid medium contained in the composition at 25°C. Furthermore, the organic solid particles (C) have a particle size of 0.1 μm or greater when present in the defoamer composition and are selected so that they do not dissolve in the defoamer composition at 25°C or that the shape of their primary particles does not change. As used herein, "primary particles" refer to isolated particles that remain intact even after dilution with a specified medium. Furthermore, as a method for determining whether the organic solid fine particles (C) are in a solid state in the liquid medium contained in the defoamer composition at 25°C, known qualitative methods can be used. For example, methods include dispersing the organic solid fine particles in a liquid medium contained in the composition at a concentration not exceeding 50% by mass, filtering or centrifuging the dispersion to separate non-flowing components, and then measuring the melting point of these components. <Particle Shape> The organic solid fine particles (C) are solid fine particles comprising an organic compound, and are selected so as not to be dispersed independently in water. Furthermore, when the particle size distribution is measured using laser diffraction-scattering measurement, for example, the particle size has a peak in the range of 0.1 μm to 150 μm. Specifically, the peak particle size (also referred to as the "maximum frequency diameter") of the organic solid fine particles (C) is preferably in the range of 0.1 μm to 150 μm, more preferably 2 μm to 150 μm, and even more preferably 2 μm to 50 μm. By ensuring that the peak particle size of the organic solid fine particles (C) is within this range, a defoamer composition having particularly excellent shear resistance can be obtained. As for the shape of the particles, particles with a concave-convex surface are more desirable than particles with a true spherical shape, and porous particles or particles with spiny protrusions are more desirable. Such particles may be, for example, clusters of microparticles whose primary particle aspect ratio is 1.1 to 100. In particular, when such clusters are used, a mixed liquid containing a defoaming liquid component (for example, a nonionic surfactant (A) or a polymer (B)) and an organic medium (D) can be better maintained on the surface of the microparticles, resulting in particularly excellent shear resistance. The aspect ratio of the primary particles can be controlled during the process of producing the organic solid microparticles (C) by appropriately adjusting the temperature at which the microparticles precipitate and crystallize, and the time the temperature is maintained. When the aspect ratio is less than 1.1, clusters are difficult to form, making it difficult to retain the defoaming liquid component, and thus difficult to achieve excellent shear resistance. On the other hand, when the aspect ratio exceeds 100, the gaps between the clusters become too large, making it difficult to retain the defoaming liquid component, and thus difficult to achieve excellent shear resistance. From the perspective of further improving shear resistance, the aspect ratio is more preferably in the range of 1.5 to 50, more preferably in the range of 2.0 to 11, and most preferably in the range of 2.0 to 9.0. The aspect ratio of the primary particles can be calculated by measuring the shape of isolated particles during observation using a transmission electron microscope (TEM) or a scanning electron microscope (SEM). Specifically, it can be calculated using the following method. The particles to be measured are diluted and suspended in an organic solvent of appropriate volatility that does not dissolve the particles. The suspension is then dropped onto a TEM observation grid or a SEM observation sample holder, and allowed to dry to prepare an observation sample. The solvent type and dilution amount are appropriately adjusted to isolate the particles. For samples prepared using a TEM or SEM, the magnification is set to a level that allows easy observation of isolated particles, and the shape of the isolated particles is confirmed. If the particle's shape is considered elliptical, the distance between the minor axis and the major axis is measured, and the ratio (major axis / minor axis) is calculated. The same measurement is performed on at least 10 particles, and the average value is used as the aspect ratio for the particle. If the particle is fibrous and difficult to be considered elliptical, the fiber length is calculated as the fiber width, with the median value of the measured fiber width being used as the fiber width. The same measurement is performed on at least 10 isolated fibrous fine particles, and the average value thereof is defined as the aspect ratio of the fibrous fine particles. <Specific Examples> The organic solid fine particles (C) are not particularly limited. For example, one or more solid fine particles of amide, urea, polyethylene, polyethylene oxide, acid-modified polyethylene, and hydrogenated castor oil can be preferably used. For example, amides can be obtained by condensing fatty acids with amines. The condensation reaction conditions (reaction temperature, component ratio, etc.) can be appropriately set using known methods. For example, fatty acids and amines as raw materials are added to a reaction vessel such as a four-necked flask and stirred in an inert gas atmosphere (e.g., under a nitrogen stream) to form a mixture. The raw material mixture is then heated and subjected to a polycondensation reaction at 150°C to 200°C for 2 to 10 hours to synthesize fatty acid amides. Monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids can be used as fatty acids, and monoamines, diamines, and triamines can be used as amines. Examples of monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated castor oil fatty acids (fatty acids having hydroxyl groups, such as 12-hydroxystearic acid (hereinafter referred to as "12-HSA") obtained by saponifying hydrogenated castor oil), saturated aliphatic monocarboxylic acids such as arachidic acid and behenic acid (behenic acid), and unsaturated aliphatic monocarboxylic acids such as oleic acid, linoleic acid, ricinoleic acid, linolenic acid, eicosenoic acid, erucic acid, and mixed fatty acids derived from natural oils and fats (such as tall oil fatty acid, rice bran fatty acid, soybean oil fatty acid, and tallow fatty acid). Among these monocarboxylic acids, it is preferred that the monocarboxylic acid contain at least a hydroxy fatty acid such as 12-HSA in order to improve the defoaming properties and shear resistance of the water-based coating. That is, as the amide used as the organic solid fine particles (C) of the present invention, an amide in which at least one of the fatty acids is a hydroxy fatty acid is preferred. As the dicarboxylic acid, for example, a dicarboxylic acid having 4 to 44 carbon atoms can be used. Examples of such dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and dimer acid. Dimer acid is a polymerized fatty acid obtained by polymerizing (dimerizing) unsaturated fatty acids (e.g., unsaturated fatty acids having 18 or 22 carbon atoms) obtained from vegetable oils such as soybean oil, tall oil, linseed oil, and cottonseed oil. Dimer acids having 36 or 44 carbon atoms are generally commercially available. As the tricarboxylic acid, for example, a tricarboxylic acid having 4 to 54 carbon atoms can be used, and examples of such tricarboxylic acids include trimer acid and trimesic acid. Trimer acid is a polymerized fatty acid obtained by distilling and refining a dimer acid to increase the trimer acid content. Trimer acid having 54 carbon atoms is generally commercially available. Examples of the monoamine include ethylamine, monoethanolamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, decylamine, laurylamine, myristylamine, cetylamine, stearylamine, 12-hydroxystearylamine, and behenylamine. Examples of the diamines that can be used include 1,2-diaminoethane (ethylenediamine (EDA)), 1,2-diaminopropane (propylenediamine (PDA)), 1,4-diaminobutane (tetramethylenediamine (TMDA)), 1,6-diaminohexane (hexamethylenediamine (HMDA)), 1,8-diaminooctane (octamethylenediamine (OMDA)), trimethylhexamethylenediamine, and 1,12-diaminododecane (dodecane). Diamines having 2 to 54 carbon atoms, such as aliphatic diamines such as o-xylenediamine, m-xylenediamine (DMDA), aromatic diamines such as diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenylsulfonium, and methylenebischloroaniline, and alicyclic diamines such as piperazine, isophoronediamine, and 1,3-bisaminomethylcyclohexane. As the triamine, for example, a triamine having 2 to 54 carbon atoms, such as an aliphatic triamine such as diethylenetriamine, can be used. Furthermore, as amines used in synthesizing the amide of the present invention, diamines or triamines derived from polymerized fatty acids, which are derivatives of polymerized fatty acids, can also be used. Examples of such polymerized fatty acid derivatives include dimer diamine (DDA), a dimer acid derivative, and trimer triamine (TTA), a trimer acid derivative. Dimer diamine, as a dimer acid derivative, is obtained by replacing the two terminal carboxyl groups of the dimer acid with a primary aminomethyl group or an amino group, and commercially available products can generally be used. Furthermore, trimer triamine, as a trimer acid derivative, is obtained by replacing the three terminal carboxyl groups of the trimer acid with a primary aminomethyl group or an amino group, and commercially available products can generally be used. The compounds used as the fatty acids and amines may be arbitrarily selected alone or in combination of two or more. Here, from the perspective of further improving shear resistance, the amide is preferably a diamide. Diamides can be obtained by reacting a fatty acid with a diamine, or by reacting a monoamine with a dicarboxylic acid. Among diamides, particularly preferred are fatty acid diamides obtained by reacting the following fatty acids with the following diamines. The fatty acids used in the synthesis of these fatty acid diamides are selected from the group consisting of alkyl fatty acids (saturated fatty acids) and hydroxy fatty acids, and include at least one hydroxy fatty acid. Furthermore, the diamines used in the synthesis of these fatty acid diamides include one or more diamines selected from the group consisting of alkylenediamines having 2 to 6 carbon atoms and m-xylylenediamine. Among these fatty acid diamides, by using ethylenebis(12-hydroxystearic acid diamide), 1,4-butanebis(12-hydroxystearic acid diamide), hexamethylenebis(12-hydroxystearic acid diamide), etc. as the organic solid fine particles (C), the water-based coating containing the defoaming agent of the present invention can have particularly excellent shear resistance. Urea is a polymer, oligomer, diurea, or monourea having a urea bond obtained by the reaction of an isocyanate compound with an amine compound. As the isocyanate compound and the amine compound, one or more compounds selected from the following compounds can be used. Examples of the isocyanate compound include aromatic monoisocyanates, aliphatic monoisocyanates, alicyclic monoisocyanates, compounds in which these monoisocyanates are rendered non-volatile to reduce their toxicity, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, compounds in which these diisocyanates are rendered non-volatile to reduce their toxicity, adducts of these diisocyanates such as biuret, uretdione, isocyanurate, and allophanate, and relatively low molecular weight urethane prepolymers. Examples of the aromatic diisocyanate include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), and m-xylylene diisocyanate (MXDI). Examples of aliphatic diisocyanates include hexamethylene diisocyanate (HDI). Examples of alicyclic diisocyanates include isophorone diisocyanate (IPDI) and hydrogenated MDI. As polyisocyanates, commercially available products may be used. Examples of commercially available products include AQUANATE 130, AQUANATE 140, AQUANATE 200, and AQUANATE 210 (manufactured by Tosoh Corporation), Bayhydur 304, Bayhydur XP-2655, Bayhydur 401-70, and Bayhydur 3100 (manufactured by Sumika Covestro). Covestro Urethane), Burnock DNW-5000, Burnock DNW-5500, Burnock DNW-6000 (manufactured by DIC Corporation), Resamine D-1063, Resamine D-2040 (manufactured by Dainichi Seika Industries, Ltd.), etc. The amine compound includes monoamine or polyamine. Examples of monoamines that can be used include aliphatic monoamines, alicyclic monoamines, aromatic monoamines, and alkanolamines. Examples of aliphatic monoamines include alkyl monoamines and other aliphatic monoamines. Examples of alkyl monoamines include octylamine, dodecylamine, octadecylamine, and octadecenylamine. Examples of alicyclic monoamines include cyclohexylamine. Examples of aromatic monoamines include aniline and toluidine. Examples of alkanolamines that can be used include ethanolamine, 2-amino-2-methyl-1-propanol, and 12-hydroxystearylamine. Examples of polyamines that can be used include aliphatic polyamines, alicyclic polyamines, and aromatic polyamines. Examples of aliphatic polyamines include alkylene polyamines, polyalkylene polyamines, and other aliphatic polyamines. Examples of alkylene polyamines include diaminomethane (methylenediamine), 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, and 1,10-diaminodecane. Examples of polyalkylene polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexamethylenetetramine. Examples of other aliphatic polyamines include tetrakis(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bis-hexamethylenetriamine, and polyethyleneimine. Examples of alicyclic polyamines include 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornyldiamine, bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, and menthene diamine (MDA). Examples of the aromatic polyamine include bis(cyanoethyl)diethylenetriamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, phenylenediamine, naphthalenediamine, diaminodiphenylmethane, diaminodiethylphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, bis(aminomethyl)naphthalene, and bis(aminoethyl)naphthalene. Oxidized polyethylene is a wax made by oxidizing polyethylene to introduce polar groups. Acid-modified polyethylene is a wax made by grafting unsaturated carboxylic acid or its anhydride onto polyethylene. Hydrogenated castor oil (also known as "hardened castor oil") is a triglyceride of saturated fatty acids obtained by hydrogenating castor oil. Commercially available hydrogenated castor oils can be used, including C-wax (manufactured by Kokura Synthetic Industries Co., Ltd.), Kao Wax 85P (manufactured by Kao Corporation), Hardened Castor Oil A (manufactured by Ito Oil Manufacturing Co., Ltd.), and Hardened Castor Oil (manufactured by Sankei Industrial Co., Ltd.). In addition, as the organic solid fine particles (C) of the present invention, in addition to the above examples, for example, polyalkyl (meth)acrylates, copolymers of dibasic acid esters, copolymers of alkyl (meth)acrylates and vinyl fatty acid esters (which are solid in the defoamer composition at 25°C (i.e., do not belong to the nonionic surfactant (A) and polymer (B)) can also be used. Among the specific examples shown above, in order to improve defoaming properties or shear resistance, it is preferable to use ethylene bis (12-hydroxystearic acid diamide), 1,4-butane bis (12-hydroxystearic acid diamide), hexamethylene bis (12-hydroxystearic acid diamide), and the like. <Content> The content of the organic solid fine particles (C) is preferably 0.1% to 10% by mass, based on the total mass of all components in the defoamer composition being 100% by mass. By setting the content of the organic solid fine particles (C) to 0.1% to 10% by mass, sufficient defoaming properties and shear resistance can be achieved. To further improve the appearance of a coating film obtained from a water-based coating composition containing the defoamer composition, the content of the organic solid fine particles (C) is preferably 1% to 5% by mass. (Organic Medium (D)) The organic medium (D) of the present invention is a component for exerting defoaming properties together with the nonionic surfactant (A) and the polymer (B), and is added to improve the diffusibility of the defoaming agent in the foam film. <Flowability> As the organic medium (D), a medium other than water that does not have a hydrophilic portion in its molecule and is liquid at 25°C can be used. Furthermore, the organic medium (D) should preferably have a weight-average molecular weight of less than 400. The use of such a medium can enhance the diffusibility of the defoaming agent of the present invention within the foam film. <Specific Example> As the organic medium (D), for example, one or more selected from the group consisting of hydrocarbon oils, alcohols, glycol ethers, and glycol esters (excluding the nonionic surfactant (A) and the polymer (B)) can be preferably used. As the hydrocarbon oil, for example, a hydrocarbon selected from the group consisting of n H 2n+2 The n-alkanes and isoalkanes represented by C n H 2n One or more of the cycloalkanes represented. As the general formula C n H 2n+2 Examples of the n-alkanes include n-hexane, n-heptane, n-octane, n-decane, n-dodecane, and liquid paraffin. Furthermore, commonly available commercially available n-alkane mixed solvents may also be used. Examples of commercially available n-alkane mixed solvents include Solvent No. 0 L (ENEOS Co., Ltd.). Any one or two or more of these solvents may be selected and used. As the general formula C n H 2n+2 Examples of isoalkanes include isohexane, isooctane, isododecane, and isohexadecane. Furthermore, commonly available commercially available isoalkane mixed solvents may also be used. Examples of commercially available isoalkane mixed solvents include IP solvent, Merveille 30 (all manufactured by Idemitsu Kosan Co., Ltd.), Shelsol T series (manufactured by Shell Chemicals), and ISOPAR series (manufactured by ExxonMobil Corporation). Any one or more of these solvents may be selected and used. As the general formula C n H 2n As an example of the cycloalkanes represented by the above, commercially available cycloalkane solvents can be used. Examples of commercially available cycloalkane solvents include methylcyclohexane, ethylcyclohexane, SWACLEAN 150 (also known as a mixture of C9 and C10 alkylcyclohexanes) (all manufactured by Maruzen Petrochemical Co., Ltd.), the Naphthesol series, and the CACTUS SOLVENT series (all manufactured by ENEOS Co., Ltd.). Any one or two or more of these solvents can be selected and used. In addition, as the organic medium (D), the organic medium of the general formula C used in the present invention can also be used. n H 2n+2 The n-alkanes and isoalkanes represented by C n H 2n A commercial solvent in which at least two or more of the cycloalkanes represented are mixed from the outset. Examples of such solvents include Naphthesol M (naphthene / isoalkane / normal alkane = 70% or more / 5% to 10% / 15% or less, a trade name of ENEOS Co., Ltd.), ISOSOL 300 (a trade name of ENEOS Co., Ltd.), ISOSOL 400 (a trade name of ENEOS Co., Ltd.), EXXSOL D80 (a mixed solvent of alkanes and cycloalkanes, a trade name of Exxon Mobil Co., Ltd.), EXXSOL D110 (a mixed solvent of alkanes and cycloalkanes, a trade name of Exxon Mobil Co., Ltd.), EXXSOL D130 (a mixed solvent of alkanes and cycloalkanes, a trade name of Exxon Mobil Co., Ltd.), and ENEOS Co., Ltd. Mobil Corporation), EXXSOL D160 (a mixed solvent of alkanes and cycloalkanes, a trade name of Exxon Mobil Corporation), etc. One or more kinds thereof can be selected and used. Examples of alcohols include ethanol, n-propanol, isopropyl alcohol (IPA), n-butanol, sec-butanol, tert-butanol, 2-ethylhexanol, isostearyl alcohol, oleyl alcohol, and TEXANOL. Examples of glycol ethers include butyl glycol, 2-ethylhexyl glycol, methyl diglycol, dimethyl diglycol, methyl triglycol (HLB: 18), methyl propylene glycol, n-propyl propylene glycol, butyl propylene glycol, methyl dipropylene glycol, propyl dipropylene glycol, and butyl dipropylene glycol. Examples of glycol esters include propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate. Furthermore, as the organic medium (D), in addition to the substances mentioned above, aromatic solvents such as xylene and toluene, ketone solvents such as methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), and methyl amyl ketone (MAK (methyl amyl ketone): also known as 2-heptanone), ether solvents such as cyclopentyl methyl ether, ester solvents such as acetates and ethyl 3-ethoxypropionate, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropaneamide, and 3-butoxy-N,N-dimethylpropaneamide, polyethers, oils and fats, and polyalkylene glycol derivatives (not included in the nonionic surfactant (A) and the polymer (B)). <Content> The content of the organic medium (D) is preferably 0.5% to 70% by mass, based on the total mass of all components in the defoamer composition being 100% by mass. A content of 0.5% to 70% by mass of the organic medium (D) allows for sufficient defoaming performance. To further enhance the defoaming effect, the content of the organic medium (D) is preferably 5% to 50% by mass. (Other Optional Ingredients) To impart other functions, the defoamer composition of the present invention may also contain other ingredients besides the aforementioned ingredients and besides the silicone compound, without impairing the characteristics of the present invention. For example, solvents, surfactants, amphiphilic compounds, and other coating additives other than defoamers may be added to uniformly dissolve or disperse the aforementioned components (A) to (D), or to improve the leveling or uniformity of the coating to which the defoamer is added. Specifically, examples include water, nonionic surfactants, ionic surfactants, leveling agents, and dispersants (excluding those included in the aforementioned nonionic surfactant (A), polymer (B), organic solid particles (C), and organic medium (D)). (Components Not Included in the Defoamer Composition of the Present Invention) The defoamer composition of the present invention preferably does not contain a silicone compound (a synthetic polymer having a main skeleton formed by siloxane bonds). If a silicone compound is included in the defoamer composition of the present invention, it may cause cratering due to the oozing of the silicone component onto the coating surface or impair coating properties. Therefore, if the defoamer composition of the present invention contains a silicone compound, it may adversely affect the appearance of a coating film applied with a water-based paint containing the defoamer composition. Therefore, in a preferred embodiment of the defoamer composition of the present invention, a silicone compound is not included. (Form of Defoaming Agent Composition) Specific forms of the defoaming agent composition of the present invention include a form in which a suspension containing organic solid fine particles (C) or an oily suspension is dispersed in a medium mainly composed of water (O (suspension) / W type emulsion), a form in which droplets mainly composed of water are dispersed in an oily suspension (W / O (suspension) type emulsion), and a form in which the W / O (suspension) type emulsion is further dispersed in a medium mainly composed of water (W / O (suspension) / W type emulsion). (Method for Preparing an Antifoaming Agent Composition) The method for preparing an antifoaming agent composition containing the above-mentioned components is not particularly limited. However, to facilitate the preparation of a uniformly dispersed antifoaming agent composition and exhibit excellent antifoaming properties, it is desirable to prepare a pre-dispersion of the organic solid fine particles (C) (hereinafter referred to as the "fine particle pre-dispersion") and add it to the mixture of the components. The fine particle pre-dispersion is preferably added while stirring using a disperser or the like. The stirring speed and temperature can be appropriately set based on the dispersion state of the organic solid fine particles (C). The method for preparing the fine particle pre-dispersion is not particularly limited and can be prepared using methods known to those skilled in the art. Examples of such methods include: melting the organic solid to be used as the fine particles for the organic solid fine particles (C) at a predetermined temperature, pouring the melt into a container pre-filled with an organic medium (D), and precipitating the organic solid fine particles (C) while cooling in the organic medium (D); or heating organic solid fine particles (C) previously adjusted to a predetermined particle size while suspended in the organic medium (D). (Applications of Defoamer Compositions) The defoamer composition of the present invention is not particularly limited in its application as long as it is added to water-based coatings, but is particularly suitable for applications requiring a high appearance or coating systems formed by multi-layer coatings. For example, the defoamer composition of the present invention can be used to impart sufficient defoaming properties during the manufacture, coating, and drying of automotive water-based base coatings, automotive water-based mid-coats, automotive water-based primer coatings, high-end furniture water-based coatings, floor coatings, building interior and exterior coatings, anti-corrosion coatings, home appliances, etc., and can prevent the occurrence of coating defects such as shrinkage cavities during the baking step. In addition, the defoamer composition of the present invention can also be preferably used in applications such as using coating raw materials that are difficult to disperse in water, and in applications such as recycling the coating to prevent sedimentation and separation of components in the coating. (Mechanism of Effect) The mechanism by which defoaming agents, such as defoaming droplets or hydrophobic particles, defoam, are exerted is well known to those skilled in the art. For example, this mechanism can be explained as follows. When defoaming droplets or hydrophobic particles penetrate the bubble membrane and the membrane thickness decreases due to water drainage, the defoaming components contained in the defoaming droplets or hydrophobic particles penetrate the membrane. Subsequently, because the defoaming components that penetrate the membrane are highly hydrophobic, water attempts to avoid them, causing the bubbles to break. To ensure minimal compatibility between hydrophobic particles and water-based coatings, they are often used in conjunction with surfactants. However, under high or prolonged shear, the surfactant detaches from the hydrophobic particles, exposing their hydrophobic surfaces. Consequently, the hydrophobic particles cannot remain stable in the water-based coating and aggregate. Agglomerated hydrophobic particles cannot redisperse, resulting in small, uneven spots, or the effective particle concentration decreases, leading to a loss of defoaming effect. Furthermore, the defoaming droplets are gradually miniaturized by the shear force, and if they cannot maintain a size that allows them to penetrate the foam film, the defoaming effect is considered to be lost. On the other hand, in the defoamer composition of the present invention, hydrophobic organic solid particles (C) are present within defoaming droplets composed of a nonionic surfactant (A), a defoaming polymer (B), and other defoaming ingredients. This is similar to the configuration of conventional composite defoamers. However, the organic solid particles (C) in the present invention are organic substances with a high affinity for the defoaming ingredients, which retains the defoaming ingredients on the particle surface, thereby preventing the hydrophobic surface of the particles from being exposed due to shear forces. Furthermore, even if the organic solid particles (C) escape from the defoaming droplets, a small amount of defoaming liquid remains on the particle surface, and they are quickly protected and colloided by the nonionic surfactant (A), suppressing aggregation of the organic solid particles (C). Furthermore, by reincorporating the protected colloided organic solid particles (C) into the defoaming droplets, the defoaming effect is restored to its optimal state. By this mechanism, even when a water-based paint to which a defoaming agent is added is exposed to high shear or to long-term shear, causing the defoaming droplets to be miniaturized or when hydrophobic particles fly out of the defoaming droplets, droplets with a defoaming effect can be reconstructed around the protected colloided particles, thereby maintaining the defoaming effect. In order to construct this mechanism, it is necessary to appropriately select and combine the materials of the nonionic surfactant (A), polymer (B), and organic solid particles (C). Regarding the imparting of shear resistance by the above mechanism, it is further desirable that the shape of the organic solid particles (C) have specific characteristics. Specifically, it is believed that (1) porous particles, (2) particles with a concave-convex surface, and (3) clusters of microcrystals with a specific aspect ratio exhibit better shear resistance. [Water-Based Paint Composition] The water-based paint composition of the present invention contains the aforementioned defoamer composition and water-based resin as essential components. Furthermore, the water-based paint composition of the present invention may further contain other paint raw materials, such as a diluent solvent, pigment, dispersant, lubricant, emulsifier, viscosity modifier, film-forming aid, and pH adjuster, as optional components. (Content of Defoamer) The content of the defoamer composition of the present invention varies depending on the type of aqueous resin used as a binder in the aqueous coating composition, the formulation of the pigment, and the like, but is generally preferably 0.1% to 5% by mass, and more preferably 0.5% to 2% by mass, relative to the aqueous coating composition. If the content of the defoamer composition is less than 0.1% by mass, there is a risk that the effects of the defoamer composition of the present invention, such as defoaming properties and shear resistance, may not be fully exerted. On the other hand, if the content of the defoamer composition exceeds 5% by mass, there is a risk that interlayer adhesion may deteriorate during repeated coating, or that uneven coating may occur in the outer coating film, or that the water resistance of the dried coating film may deteriorate, which is undesirable. (Water-Based Resin) The water-based resin contained as a binder in the water-based coating composition of the present invention is a resin component dispersed in a water-based medium. Examples of the resin component include acrylic resins, acrylic-silicone resins, alkyd resins, polyester resins, urethane resins, epoxy resins, silicone resins, and fluororesins. Water-based resins can be classified into water-soluble, colloidal dispersions, and emulsions based on their dispersion form, and any of these forms can be used. These resins can be, for example, heat-curing, UV-curing, electron beam-curing, oxidation-curing, photocationic curing, and peroxide-curing, as well as those that cure with a chemical reaction in the presence or absence of a catalyst. They can also have a high glass transition point and form a coating solely through volatilization of the diluent without a chemical reaction. Examples of the curing agent include amino resins, melamine resins, isocyanate compounds, blocked isocyanate compounds, silane coupling agents, and epoxy compounds. (Pigments) Examples of pigments include: extender pigments such as calcium carbonate (ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), etc.), barium sulfate, silica, aluminum hydroxide, talc, mica, organic fiber, and glass powder; coloring pigments such as titanium dioxide, carbon black, yellow lead, cadmium yellow, ochre, titanium yellow, zinc chromate, red iron oxide, aluminosilicate, quinacridone-based, phthalocyanine-based, anthraquinone-based, diketopyrrolopyrrole-based, benzimidazolone-based, and isoindolinone-based; and metallic pigments such as aluminum flakes, copper flakes, mica-like iron oxide, mica, and flaky powders obtained by coating mica with a metal oxide. (Other Additives) The water-based paint composition of the present invention may contain other substances, such as dispersants, lubricants, emulsifiers, viscosity modifiers, dehydrating agents (e.g., silane coupling agents), adhesion enhancers, surfactants, curing catalysts, film-forming aids, desiccants, contamination inhibitors, sensitizers, antioxidants, light stabilizers, ultraviolet absorbers, water-resistant agents, anticorrosive and antifungal agents, leveling agents, flame retardants, antistatic agents, release agents, deodorants, pH adjusters, fragrances, and other additives, within the range that does not impair the properties or the purpose of the present invention. Surfactants are commonly used as dispersants for dispersing pigments in coatings, wetting agents for improving pigment wettability or smoothness, emulsifiers for emulsifying non-aqueous resins, and viscosity modifiers for controlling coating fluidity. These agents generate unwanted foam during the production and application of water-based coatings. However, by incorporating the defoamer composition of the present invention into a water-based coating composition, the generation and retention of foam can be suppressed, and excellent defoaming properties can be maintained even when high shear forces are applied to the coating. As a result, a coating film with an excellent finished appearance can be formed without hindering exterior coating properties. (Method for Producing Water-Based Coating Compositions) The water-based coating composition of the present invention can be produced according to known methods for producing water-based coatings. For example, the defoamer composition and ingredients other than the pigment are mixed while stirring in a water-based medium such as ion-exchanged water, and the pH is adjusted as necessary to produce a clear coating. The water-based coating composition can be produced by adding the defoamer composition and the pigment to the clear coating and dispersing them in the clear coating. Furthermore, the defoamer composition of the present invention can be added to the water-based paint during the pigment mixing process as described above, or it can be added after the water-based paint is manufactured. Alternatively, a masterbatch can be prepared and added. Furthermore, the equipment used to disperse the defoamer composition and pigment can be equipment commonly used in the manufacture of water-based paints. Furthermore, the stirring speed and stirring time during the dispersion of the defoamer composition and pigment are not particularly limited and can be appropriately set while confirming the dispersion state of the defoamer composition and pigment. (Applications of the Water-Based Paint Composition) The water-based paint composition of the present invention is particularly suitable for applications requiring a high appearance or for coating systems comprising multilayer coatings. Examples of such applications include coating automotive materials, coating high-end furniture materials, floor coatings, interior and exterior building coatings, anti-corrosion coatings, and coatings for household appliances. Furthermore, the water-based paint composition of the present invention is also preferably used in applications where paint raw materials that are difficult to disperse in water are used, and where paint recycling is required to prevent sedimentation and separation of paint components. [Article] The article of the present invention is obtained by coating the surface of a substrate as a coated object with a coating agent containing the defoaming agent composition. Specifically, the article of the present invention comprises: a substrate; and a coating film obtained by coating the surface of the substrate with the coating agent. (Substrate) The substrate of the article of the present invention is not particularly limited, and examples thereof include substrates made of metal, plastic, wood, rubber, glass, stone, cement, mortar, paper, nonwoven fabric, cloth, and ceramics. (Coating Film) The coating film possessed by the article of the present invention can be obtained, for example, by applying the water-based coating composition to the substrate and then curing the coating film. The coating film formed on the substrate surface may be a single layer or a laminate of multiple layers. The water-based coating composition containing the defoamer composition of the present invention has excellent defoaming properties and shear resistance. Therefore, even when the water-based coating composition is used in applications requiring extremely high appearance and external coating properties, a satisfactory coating film appearance can be achieved without impairing external coating properties. (Coating Agent) Examples of the coating agent of the present invention used for coating the substrate include the above-mentioned water-based coating composition. (Article Manufacturing Method) The article of the present invention can be manufactured by applying a coating agent, such as the water-based coating composition of the present invention, to the substrate, followed by drying and curing. The coating agent application method is not particularly limited, and examples include spraying, roller coating, brush coating, curtain coating, bar coating, doctor blade coating, slit coating, dip coating, and flow coating. The coating agent curing method is not particularly limited, and examples include room temperature curing, heat curing, and ultraviolet curing. In addition, when forming a multilayer coating film (multilayer coating film) on the article of the present invention, for example, it includes a coating film (primer coating film) obtained by applying the water-based paint composition of the present invention to a substrate, and an outer coating film accumulated on all or part of the surface of the coating film. The coating to be applied externally can use the same coating as the coating used for the primer coating film, or a different coating can be used. In addition, when forming a multilayer coating film, the primer coating can be completely dried or hardened before external application, or the primer coating can be applied externally in an incompletely dried or hardened state within the scope that the primer coating is not disturbed by the external application. Since the external application property of the water-based paint composition containing the defoamer composition of the present invention is excellent, even when the water-based paint composition is used in applications requiring extremely high appearance and external application property, the interlayer adhesion between the coating film obtained by the water-based paint composition and the outer coating film is also excellent. When a multilayer coating film is formed on the article of the present invention, the multilayer coating film is formed, for example, by applying an outer coating to all or part of the surface of the coating film obtained by hardening the base water-based paint to which the defoamer composition of the present invention is added. Alternatively, the outer coating can be wet-applied without hardening the base water-based paint to which the defoamer composition of the present invention is added, and then the base and outer coatings are hardened simultaneously. In this case, it is preferred that after applying the base water-based paint to which the defoamer composition of the present invention is added, natural drying, air blast or preheat drying is performed as needed to remove unnecessary solvents (volatile components such as water or organic solvents) without hardening the base water-based paint, and then the outer coating is applied. Preheat drying is particularly suitable as a drying method for the base water-based paint. The coating method and curing method of the topcoat are not particularly limited, and the same methods as those described above can be used. (Applications of Articles) The articles of the present invention are particularly suitable for applications requiring a high appearance or coating systems formed of multilayer coatings. Examples of such applications include automobile parts, high-end furniture, and home appliances. While the preferred embodiments of the present invention have been described above, the present invention is not limited to the aforementioned embodiments. Specifically, it is understood that other embodiments or various modifications that can be imagined by a person skilled in the art within the scope of the invention described in the claims also fall within the technical scope of the present invention. Specifically, the invention includes the following: (1) A defoamer composition for use in water-based coatings, the defoamer composition comprising a nonionic surfactant (A), a polymer (B), and organic solid particles (C), wherein the nonionic surfactant (A) has at least one hydrophilic portion selected from the group consisting of an ethylene glycol portion, a polyethylene glycol portion, and a polyol portion in its molecule, and has an HLB of 1 to 16; the polymer (B) does not have the hydrophilic portion in its molecule, has an SP value of 7.5 to 12, and has a weight-average molecular weight of 400 to 1,000,000; and the organic solid particles (C) are in a solid state in the defoamer composition at 25°C. (2) The defoaming agent composition as described in (1), characterized in that the nonionic surfactant (A) is one or more selected from the group consisting of ethylene glycol aliphatic ethers, polyoxyalkylene aliphatic ethers, polyoxyalkylene aromatic ethers, polyoxyalkylene fatty acid esters, alkylene oxide addition derivatives of castor oil, alkylene oxide addition derivatives of hydrogenated castor oil, polyoxyalkylene polyol ethers, polyol fatty acid esters, alkylene oxide addition derivatives of polyol fatty acid esters, polyoxyalkylene alkylamides, acetylene glycol and its derivatives, alkylene oxide addition derivatives of acetylene glycol, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers. (3) The defoamer composition as described in (1) or (2), characterized in that the polymer (B) is one or more polymers selected from the group consisting of polyvinyl alkyl ether, polybutadiene, polybutylene, polyisoprene, polyα-olefin, poly(meth)acrylate, copolymer of dibasic acid ester, polyvinyl fatty acid ester, and copolymer of alkyl (meth)acrylate and vinyl fatty acid ester. (4) The defoamer composition as described in any one of (1) to (3), characterized in that the organic solid particles (C) are one or more solid particles selected from the group consisting of amide, urea, polyethylene, oxidized polyethylene, acid-modified polyethylene, and hydrogenated castor oil. (5) The defoamer composition according to (4), characterized in that the amide is a fatty acid diamide obtained by reacting a fatty acid with a diamine, wherein the fatty acid is selected from the group consisting of alkyl fatty acids and hydroxy fatty acids and contains at least one hydroxy fatty acid, and the diamine contains one or more diamines selected from the group consisting of alkylenediamines having 2 to 6 carbon atoms and meta-xylenediamine. (6) The defoamer composition according to any one of (1) to (5), characterized in that the aspect ratio of the crystals of the organic solid particles (C) is 1.1 to 100. (7) The defoamer composition according to any one of (1) to (6), characterized in that the peak particle size (maximum frequency diameter) of the organic solid particles (C) is 0.1 μm to 150 μm.(8) The defoamer composition according to any one of (1) to (7), characterized in that it further contains an organic medium (D) that does not have the hydrophilic part in the molecule and is liquid at 25°C other than water, and the weight average molecular weight of the organic medium (D) is less than 400. (9) The defoamer composition according to (8), characterized in that the organic medium (D) is one or more selected from the group consisting of hydrocarbon oils, alcohols, glycol ethers and glycol esters. (10) The defoamer composition according to any one of (1) to (9), characterized in that it does not contain a silicone compound. (11) A water-based coating composition, characterized in that it contains the defoamer composition according to any one of (1) to (10) and a water-based resin. (12) An article coated with a coating agent containing the defoamer composition according to any one of (1) to (10). [Examples]. The present invention is described in detail below with reference to the following examples. The present invention is not limited in any way by these examples. In addition, unless otherwise specified, "%" and "parts" in the examples represent "mass %" and "mass parts." [Preparation of Antifoaming Agent Samples] Antifoaming agent samples E1 to E54 and antifoaming agent samples C1 to C25 were prepared as follows. (Preparation of Nonionic Surfactant) In the present examples and comparative examples, the raw materials listed in Table 1 below were used as the nonionic surfactant component comprising the nonionic surfactant (A). The HLB of the nonionic surfactant is a value determined by the Griffin method. Raw materials listed as "A" in Table 1 are examples of the nonionic surfactant (A) of the present invention, while raw materials listed as "non-A components" are raw materials that do not correspond to the nonionic surfactant (A) of the present invention. [Table 1] Table 1 Raw materials of defoaming agent samples (non-ionic surfactants) (Polymer Synthesis and Preparation) In the present examples and comparative examples, the raw materials listed in Table 2 below were used as polymer components comprising polymer (B). Raw materials listed as "B" in Table 2 are examples of polymer (B) according to the present invention, while raw materials listed as "non-B components" are raw materials that do not correspond to polymer (B) according to the present invention. The following describes the synthesis methods for raw materials listed as "Synthesis method described in this application" in Table 2's "Source of Acquisition." <Synthesis of PEVE> Polyethyl vinyl ether (hereinafter referred to as "PEVE") was synthesized as an example of polymer (B) by the method shown below. In a 1000 ml reaction vessel including a stirrer, a reflux cooler, a dropping funnel, a thermometer, and a nitrogen inlet tube, 150 parts of toluene and 3 parts of a boron fluoride diethyl ether complex as a cationic polymerization initiator diluted to 10% with diethyl ether were placed. After heating to 30°C while introducing nitrogen, the following dropwise solution (a) was uniformly added dropwise using a dropping funnel over 120 minutes. Dropwise solution (a) 300 parts of ethyl vinyl ether 100 parts of toluene Thirty minutes after the dropwise addition of solution (a) was complete, 15 parts of ethanol was added to terminate the reaction. After the reaction was complete, the solvent was removed using an evaporator to obtain a polymer (PEVE). The synthesized polymer had a weight-average molecular weight of 3000 (SP value: 8.6). <Synthesis of Acrylic Polymer 1> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 95.0 parts of butyl acetate and 159.4 parts of dibutyl fumarate. The internal temperature was then raised to 140°C (reflux) under a nitrogen flow while stirring. A mixture containing 28.1 parts of dibutyl fumarate, 187.5 parts of ethyl acrylate, 30.0 parts of a 55% solution of 2,2-di(tert-amylperoxy)butane, and 7.5 parts of 2-ethylhexyl thioglycolate was added to the dropping funnel as a dropwise solution. This dropwise solution was then uniformly added dropwise over 120 minutes while maintaining the internal temperature of the reaction vessel at reflux. After the dropwise addition was completed, the reaction temperature was maintained at reflux for 120 minutes. After the reaction, the solvent was removed using an evaporator to obtain Acrylic Copolymer 1. The weight average molecular weight of the synthesized copolymer was 3500 (SP value: 10.1). <Synthesis of Polyvinyl Neodecanoate> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 104.6 parts of butyl acetate. The internal temperature was then raised to reflux under a nitrogen flow while stirring. A mixture containing 375.0 parts of vinyl neodecanoate (trade name VeoVa 10, manufactured by HEXON) and 20.5 parts of a 55% solution of 2,2-di(tert-amylperoxy)butane was added to the dropping funnel as the dropping solution. While maintaining the internal temperature of the reaction vessel at reflux, the dropping solution was uniformly added dropwise over 120 minutes. After the dropwise addition was completed, the reaction temperature was maintained at reflux for 60 minutes. After the reaction, the solvent was removed using an evaporator to obtain polyvinyl neodecanoate. The synthesized copolymer had a weight-average molecular weight of 7900 (SP value: 9.0). <Synthesis of Acrylic Polymer 2> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 197.5 parts of an isoparaffin solvent (trade name: MERVEILLE 30; Idemitsu Kosan Co., Ltd.). The internal temperature was then raised to 95°C while stirring under a nitrogen flow. A mixture containing 250.0 parts of lauryl methacrylate, 49.4 parts of an isoparaffin solvent (trade name: MERVEILLE 30; Idemitsu Kosan Co., Ltd.), and 3.1 parts of a 40% solution of t-butyl peroxy-2-ethylhexanoate was added to the dropping funnel as a dropwise solution. This dropwise solution was then uniformly added dropwise over 75 minutes while maintaining the internal temperature of the reaction vessel at 95°C. After the addition was complete, the reaction temperature was maintained at 95°C for 60 minutes. Then, 0.7 parts of a 40% solution of t-butyl peroxy-2-ethylhexanoate was added, and the temperature was maintained at 95°C for 45 minutes. The internal temperature of the reaction vessel was then raised to 100°C and the reaction was allowed to proceed for 30 minutes. After the reaction, the heat residue was adjusted to 50% using an isoparaffin solvent (trade name: MERVEILLE 30, Idemitsu Kosan Co., Ltd.) to obtain acrylic copolymer 2. The synthesized copolymer had a weight-average molecular weight of 178,900 (SP value: 9.0). <Synthesis of Acrylic Polymer 3> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 188.5 parts of an isoparaffin solvent (trade name: MERVEILLE 30; Idemitsu Kosan Co., Ltd.). The internal temperature was then raised to 95°C while stirring under a nitrogen flow. A mixture containing 250.0 parts of lauryl methacrylate, 47.1 parts of an isoparaffin solvent (trade name: MERVEILLE 30; Idemitsu Kosan Co., Ltd.), and 12.5 parts of a 40% solution of t-butyl peroxy-2-ethylhexanoate was added to the dropping funnel as a dropwise solution. This dropwise solution was then uniformly added dropwise over 75 minutes while maintaining the internal temperature of the reaction vessel at 95°C. After the addition was complete, the reaction temperature was maintained at 95°C for 60 minutes. Then, 0.7 parts of a 40% solution of t-butyl peroxy-2-ethylhexanoate was added, and the temperature was maintained at 95°C for 45 minutes. The internal temperature of the reaction vessel was then raised to 100°C and the reaction was allowed to proceed for 30 minutes. After the reaction, the heated residue was adjusted to 50% using an isoparaffin solvent (trade name: MERVEILLE 30, Idemitsu Kosan Co., Ltd.) to obtain acrylic copolymer 3. The synthesized copolymer had a weight-average molecular weight of 74,100 (SP value: 9.0). <Synthesis of Acrylic Polymer 4> 350.0 parts of methylpropanediol were placed in a 1000 mL reaction vessel equipped with a stirrer, a reflux cooler, a dropping funnel, a thermometer, and a nitrogen inlet tube. The internal temperature was then raised to 120°C while stirring under a nitrogen stream. A mixture containing 75.0 parts of acrylic acid, 50.0 parts of styrene, 25.0 parts of a 50% solution of tert-amyl peroxy-2-ethylhexanoate, and 6.3 parts of 2-ethylhexyl thioglycolate was placed in the dropping funnel as a dropping solution. Next, while maintaining the internal temperature of the reaction vessel at 120°C, the dropping solution was uniformly added dropwise over 120 minutes. After the dropwise addition was completed, the reaction temperature was maintained at 120°C for 60 minutes, and then 0.8 parts of a 50% solution of tert-amyl peroxy-2-ethylhexanoate was added, and the reaction was maintained at 120°C for 30 minutes to allow the reaction to proceed. After the reaction was completed, the solvent was removed using an evaporator to obtain acrylic copolymer 4. The weight average molecular weight of the synthesized copolymer was 3600 (SP value: 12.4). <Synthesis of Acrylic Polymer 5> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 200 parts of butyl acetate. The internal temperature was then raised to reflux of the butyl acetate while stirring under a nitrogen stream. A mixture of 250 parts of ethyl acrylate and 50 parts of a 50% solution of t-amyl peroxy-2-ethylhexanoate was placed in the dropping funnel as the dropping solution. The dropping solution was then uniformly added dropwise over 100 minutes while maintaining the internal temperature of the reaction vessel at reflux. After the dropwise addition was completed, the reaction temperature was maintained at reflux for 60 minutes, followed by the dropwise addition of 1.5 parts of a 50% solution of t-amyl peroxy-2-ethylhexanoate, and the reaction was allowed to proceed for 30 minutes. After the reaction was completed, the solvent was removed using an evaporator to obtain acrylic copolymer 5. The synthesized copolymer had a weight-average molecular weight of 3900 (SP value: 10.2). <Synthesis of Acrylic Polymer 6> A 1000 mL reaction vessel equipped with a stirrer, reflux cooler, dropping funnel, thermometer, and nitrogen inlet tube was charged with 108.0 parts of butyl acetate. The internal temperature was then raised to reflux of the butyl acetate while stirring under a nitrogen stream. A mixture containing 375.0 parts of 2-ethylhexyl acrylate and 17.2 parts of a 55% solution of 2,2-di(tert-amylperoxy)butane was added to the dropping funnel as a dropwise solution. This dropwise solution was then uniformly added dropwise over 120 minutes while maintaining the internal temperature of the reaction vessel at reflux. Following the completion of the dropwise addition, the reaction temperature was maintained at reflux for 60 minutes. After the reaction, the solvent was removed using an evaporator to obtain acrylic copolymer 6. The synthesized copolymer had a weight-average molecular weight of 7800 (SP value: 9.2). The SP values ​​of the polymers shown in Table 2 were calculated using the Fedors method. The weight-average molecular weights of the polymers shown in Table 2 were determined using an HLC-8320GPC (manufactured by Tosoh Corporation) as the measuring instrument. TSK gel GMHxl×2, TSKgel G2500Hxl, TSKgel G2000Hxl, and TSKgel guard columns (all manufactured by Tosoh Corporation) were used as columns. Tetrahydrofuran (THF) was used as the mobile phase. The column temperature was set to 40°C, the flow rate was set to 1 mL / min, and an RI detector was used as the detector. The weight-average molecular weights shown in Table 2 were calculated based on the molecular weight of standard polystyrene using chromatograms measured by gel permeation chromatography (GPC). [Table 2] Table 2 Raw materials (polymers) of defoamer samples (Production and Preparation of Solid Particles) In these Examples and Comparative Examples, the raw materials listed in Table 3 below were used as the solid particle component containing organic solid particles (C). Raw materials listed as "C" in Table 3 are examples of the organic solid particles (C) of the present invention, while raw materials listed as "non-C components" are not equivalent to the organic solid particles (C) of the present invention. The following describes methods for producing raw materials whose "Source" in Table 3 is "Production Method Described in This Application." Specifically, particles OC-1 to OC-18, examples of organic solid particles (C), were produced using the following method. <OC-1> 2 mol of 12-hydroxystearic acid (12-HSA) and 1 mol of hexamethylenediamine were reacted at 190°C for 6 hours under a nitrogen stream to remove the generated water, thereby obtaining diamide (a1) (Step 0). Next, a mixture (microparticle mixture) of 10 parts of diamide (a1) as a microparticle component and 90 parts of Merveille 30 (an isoalkane manufactured by Idemitsu Kosan Co., Ltd.) as an organic medium (D) was heated to 165°C using a heater to dissolve the diamide (a1) in Merveille 30 by heating, thereby obtaining a microparticle solution (Step 1). Separately, 60 parts of Merveille 30 were placed in a 500 mL container, and the microparticle solution was added thereto while stirring. The mixture was then cooled to a temperature of 97.0°C after mixing (Step 2). After the mixture containing the microparticle dissolving solution was cooled to approximately 30°C, 40 parts of ethanol was added to the mixture and stirred (Step 3). Next, while stirring was maintained, the temperature of the mixture was adjusted to 46.5°C and stirring was continued for 12 minutes to obtain a preliminary dispersion of the OC-1 microparticles (Step 4). <OC-2> In step 0, diamide (a2) was obtained by reacting 2 mol of 12-HSA with 1 mol of ethylenediamine. In step 1, diamide (a2) was used instead of diamide (a1), and the microparticle mixture was heated to 155°C. In step 2, the mixture was cooled to a temperature of 88.0°C after mixing. In step 4, the temperature of the mixed solution was adjusted to 48.5°C. A pre-dispersion of microparticles OC-2 was obtained by the same method as OC-1, except that the diamide (a2) was used instead of diamide (a1). <OC-3> In step 0, diamide (a3) ​​was obtained by reacting 2 mol of 12-HSA with 1 mol of 1,4-diaminobutane. In step 1, diamide (a3) ​​was used instead of diamide (a1), and the microparticle mixture was heated to 160°C. In step 2, the mixture was cooled to a temperature of 97.0°C after mixing. In step 4, the temperature of the mixed solution was adjusted to 42.0°C. A pre-dispersion of microparticles OC-3 was obtained by the same method as OC-1, except that the diamide (a3) ​​was used instead of diamide (a1). <OC-4> A preliminary dispersion of fine particles OC-4 was obtained by the same method as OC-3, except that the mixture was cooled to 92.5°C in step 2 and the temperature of the mixed solution was adjusted to 45.3°C in step 4. <OC-5> A pre-dispersion of fine particles OC-5 was obtained by the same method as OC-1, except that hardened castor oil was used instead of diamide (a1); the fine particle mixture was heated to 95°C in step 1; and the mixture was cooled to a temperature of 53.9°C after mixing in step 2. Step 4 was omitted. <OC-6> A pre-dispersion of fine particles OC-6 was obtained by the same method as for OC-1, except that butanediol was used as the organic medium (D) in steps 1 and 2, the fine particle mixture was heated to 120°C, and cooled in step 2 to a temperature of 25.0°C after mixing. Step 4 was omitted. <OC-7> A pre-dispersion of fine particles OC-7 was obtained by the same method as for OC-1, except that low-density oxidized polyethylene (trade name "AC 629" manufactured by Honeywell Japan, Ltd.) was used instead of diamide (a1). The fine particle mixture was heated to 150°C in step 1 and cooled to a temperature of 46.7°C after mixing in step 2. Step 4 was omitted. <OC-8> A preliminary dispersion of fine particles OC-8 was obtained by the same method as OC-1, except that the mixture was cooled to 47.7°C in step 2 and the temperature of the mixed solution was adjusted to 38.7°C in step 4. <OC-9> A preliminary dispersion of fine particles OC-9 was obtained by the same method as OC-1, except that the mixture was cooled to 44.7°C after mixing in step 2 and the temperature of the mixed liquid was adjusted to 40.3°C in step 4. <OC-10> A pre-dispersion of fine particles OC-10 was obtained by the same method as for OC-1, except that 2-ethylhexanol was used as the organic medium (D) in steps 1 and 2, the fine particle mixture was heated to 135°C, the mixture was cooled in step 2 to a temperature of 51.4°C after mixing, and the temperature of the mixed solution was adjusted to 57.7°C in step 4. <OC-11> A pre-dispersion of fine particles OC-11 was obtained by the same method as for OC-1, except that 2-ethylhexanol was used as the organic medium (D) in steps 1 and 2, the fine particle mixture was heated to 135°C, the mixture was cooled in step 2 to a temperature of 45.5°C after mixing, and the temperature of the mixed solution was adjusted to 62.1°C in step 4. <OC-12> A pre-dispersion of fine particles OC-12 was obtained by the same method as for OC-1, except that methylpropanediol was used as the organic medium (D) in steps 1 and 2, the fine particle mixture was heated to 110°C, the mixture was cooled in step 2 to a temperature of 48.5°C after mixing, and the temperature of the mixed solution was adjusted to 50.4°C in step 4. <OC-13> A preliminary dispersion of fine particles OC-13 was obtained by the same method as OC-2, except that the mixture was cooled to 37.4°C after mixing in step 2 and the temperature of the mixed solution was adjusted to 61.3°C in step 4. <OC-14> A pre-dispersion of fine particles OC-14 was obtained by the same method as for OC-1, except that methylpropanediol was used as the organic medium (D) in steps 1 and 2, the fine particle mixture was heated to 110°C, the mixture was cooled in step 2 to a temperature of 38.5°C after mixing, and the temperature of the mixed solution was adjusted to 57.4°C in step 4. <OC-15> After step 3, instead of step 4, the mixed solution obtained in step 3 was placed in a bottle, heated to 70°C over 24 hours, and maintained at that temperature for 24 hours. The temperature was then lowered to 25°C over 24 hours. A pre-dispersion of fine particles OC-15 was obtained by the same method as for OC-1, except that the mixture was heated to 70°C over 24 hours and maintained at that temperature for 24 hours. <OC-16> After step 3, instead of step 4, the mixed solution obtained in step 3 was placed in a bottle, heated to 80°C over 24 hours, and maintained at that temperature for 24 hours. The temperature was then lowered to 25°C over 24 hours. A pre-dispersion of fine particles OC-16 was obtained by the same method as for OC-1, except that the mixture was cooled to 25°C over 24 hours. <OC-17> A preliminary dispersion of fine particles OC-17 was obtained by the same method as OC-2, except that the mixture was cooled to 45.6°C in step 2 and the temperature of the mixed solution was adjusted to 45.5°C in step 4. <OC-18> In step 0, diamide (a4) was obtained by reacting 2 mol of 12-HSA with 1 mol of m-phenylenediamine. In step 1, diamide (a4) was used instead of diamide (a1), and the microparticle mixture was heated to 150°C. In step 2, the mixture was cooled to a temperature of 46.5°C after mixing. In step 4, the temperature of the mixed solution was adjusted to 47.3°C. A pre-dispersion of microparticles OC-18 was obtained by the same method as OC-1, except that the diamide (a4) was used instead of diamide (a1). <Measurement of Peak Particle Diameter> The peak particle diameter of the microparticles OC-1 to OC-18 obtained as described above was measured using a Microtrac MT-3000 EXII / USVR particle size distribution analyzer (manufactured by Microtrac) using a Merveille 30 as the circulating solvent. The peak particle diameter (μm) of each organic solid microparticle is shown in Table 3. <Aspect Ratio Measurement> The aspect ratios of the microparticles OC-1 to OC-18 obtained as described above were measured according to steps 1) to 7) below. 1) A pre-dispersion of microparticles OC-1 to OC-18 was diluted 300-fold with xylene and irradiated with ultrasound for 30 seconds to disperse the microparticles in the dilution. 2) One drop of the dilution from step 1) was added to a copper microgrid (grid pitch 150 μm) with a carbon-reinforced collodion support film on filter paper and allowed to dry naturally. 3) The microgrid, carrying the sample of microparticles obtained in step 2), was fixed to the SEM mount using carbon tape. 4) SEM measurements were performed under the following conditions: measuring instrument: SU3500 (manufactured by Hitachi High-Technologies Co., Ltd.), measurement mode: high vacuum, low accelerating voltage, image acquisition: backscattered electron imaging, acquisition magnification: 2,000x, brightness / contrast: automatic, focus: manual. 5) Image Analysis: Using image analysis software (ImageJ), after brightness / contrast correction and smoothing correction, the image was binarized to remove noise, particles at the image boundary, and agglomerated particles for particle analysis. 6) If the particles to be measured consisted solely of non-convex shapes, particle analysis was performed. The aspect ratio (= major diameter value / minor diameter value) was calculated from the obtained major diameter and minor diameter values ​​of each particle. The average aspect ratio of 10 or more particles was used as the aspect ratio of the microparticle sample (microparticles OC-1 to OC-18). 7) If the particles to be measured contained both convex and non-convex shapes, the fiber length was measured using the freehand line tool, and the fiber width at the center of the particle was measured using the straight line tool. The aspect ratio (= fiber length value / fiber width value) was calculated. The average aspect ratio of 10 or more particles was used as the aspect ratio of the sample. Furthermore, the term "non-convex shape" refers to a shape in which the area of ​​the particle's convex hull (the portion enclosed by a shrinkable imaginary curve) is at least twice the actual area. Furthermore, the term "convex shape" refers to a shape in which the area of ​​the particle's convex hull is less than twice the actual area. The aspect ratios of various organic solid fine particles are shown in Table 3. [Table 3] Table 3 Raw materials of defoaming agent samples (solid particles) (Preparation of Organic Medium) In the present Examples and Comparative Examples, the raw materials described in the following Table 4 were used as the organic medium (D). In addition, Table 4 describes the boiling points of some of the raw materials. [Table 4] Table 4 Raw materials of defoamer samples (organic medium) (Preparation of Defoamer Samples) Defoamer samples E1 to E54 and C1 to C25 were prepared by the method described below. The details of the preparation method of each defoamer sample are as follows. <Defoamer Sample E1> A 100 mL plastic cup was charged with 7.5 parts of Emulex RWIS-305 (PEG-5 triisostearate hydrogenated castor oil, manufactured by Nippon Emulsion Co., Ltd.) and 27.5 parts of PEVE. While stirring with a disperser, 30.0 parts of the pre-dispersion of fine particles OC-1 was added. The mixture was then stirred and mixed at 2000 rpm for 15 minutes to obtain Defoamer Sample E1. <Antifoaming Agent Sample E2> An antifoaming agent sample E2 was obtained by the same method as that of the antifoaming agent sample E1, except that the pre-dispersion of fine particles OC-1 was changed to the pre-dispersion of fine particles OC-2. <Antifoaming Agent Sample E3> An antifoaming agent sample E3 was obtained by the same method as that of the antifoaming agent sample E1, except that the pre-dispersion of fine particles OC-1 was changed to the pre-dispersion of fine particles OC-3. <Antifoaming Agent Sample E4> An antifoaming agent sample E4 was obtained by the same method as for the antifoaming agent sample E1, except that Elamex RWIS-305 was replaced with Elamex RWIS-330 (PEG-30 triisostearate hydrogenated castor oil manufactured by Nippon Emulsion Co., Ltd.). <Antifoaming Agent Sample E5> An antifoaming agent sample E5 was obtained by the same method as that for the antifoaming agent sample E1, except that Emalex RWIS-305 was replaced with BLAUNON CW-3 (PEG-3 hydrogenated castor oil manufactured by Aoki Oil & Fats Industry Co., Ltd.). <Antifoaming Agent Sample E6> An antifoaming agent sample E6 was obtained by the same method as that of the antifoaming agent sample E2, except that Elamex RWIS-305 was replaced with BLAUNON CW-3 (PEG-3 hydrogenated castor oil manufactured by Aoki Oil & Fats Industry Co., Ltd.). <Antifoaming Agent Sample E7> An antifoaming agent sample E7 was obtained by the same method as that for the antifoaming agent sample E3, except that Emalex RWIS-305 was replaced with BLAUNON CW-3 (PEG-3 hydrogenated castor oil manufactured by Aoki Oil & Fats Industry Co., Ltd.). <Defoamer Samples E8 to E18> Defoamer Samples E8 to E18 were obtained by the same method as Defoamer Sample E1, except that Emalex RWIS-305 was replaced with "A: nonionic surfactant" listed in Table 6, and polymer (B) was replaced with Durasyn 164. <Defoamer Sample E19> Defoamer Sample E19 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was changed to 10.3 parts of PEVE and 3.4 parts of RB810, the polymer (PEVE and RB810) was diluted with MERVEILLE 30:13.8 parts, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample E20> Defoamer Sample E20 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 22.0 parts of Acrylic Polymer 1, the polymer (Acrylic Polymer 1) was diluted with 5.5 parts of 2-ethylhexanol, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-10. <Antifoam Sample E21, Antifoam Sample E22, and Antifoam Samples E24 to E26> Antifoam Samples E21, E22, and E24 to E26 were obtained by the same method as for Antifoam Sample E1, except that PEVE was changed to "B: polymer" described in Table 7. <Defoamer Sample E23> Defoamer Sample E23 was obtained by the same method as Defoamer Sample E1, except that Elamex RWIS-305 was replaced with Elamex RWIS-320 (PEG-20 hydrogenated castor oil triisostearate, manufactured by Nippon Emulsion Co., Ltd.) and PEVE was replaced with polyvinyl neodecanoate. <Defoamer Sample E27> Defoamer Sample E27 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 27.5 parts of a MERVEILLE 30 (solvent) solution of acrylic polymer 2 (polymer concentration: 50 mass %) and mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample E28> Defoamer Sample E28 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 27.5 parts of a MERVEILLE 30 (solvent) solution of acrylic polymer 3 (polymer concentration: 50 mass %) and mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample E29> Defoamer Sample E29 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 18.6 parts of Lutonal I 60 (a solvent naphtha solution with a PIBVE concentration of 80% by mass), a polyisobutyl vinyl ether (PIBVE) manufactured by BASF, and the polymer (Lutonal I 60) was diluted with 8.9 parts of Merveille 30 before being mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample E30> Defoamer Sample E30 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 11.5 parts of Lutonal I 60 (a solvent naphtha solution with a PIBVE concentration of 80% by mass), the polymer (Lutonal I 60) was diluted with 16.0 parts of Merveille 30, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample E31> Defoamer Sample E31 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 15.3 parts of PIBVE (an isoparaffin solution with a PIBVE concentration of 60% by mass) manufactured by Siwei, and the polymer (PIBVE manufactured by Siwei) was diluted with MERVEILLE 30:12.2 parts, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Antifoaming Agent Samples E32 to E44> Antifoaming Agent Samples E32 to E44 were obtained by the same method as for Antifoaming Agent Sample E1, except that the pre-dispersion of fine particles OC-1 was changed to "C: organic solid fine particles (fine particles OC-4 to OC-16)" described in Table 8. <Defoamer Sample E45> Defoamer Sample E45 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 22.0 parts of Acrylic Polymer 5, the polymer (Acrylic Polymer 5) was diluted with 5.5 parts of 2-ethylhexanol, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-10. <Defoamer Samples E46 to E54> Defoamer Samples E46 to E54 were obtained by the same method as for Defoamer Sample E1, except that Emalex RWIS-305 was replaced with "A: nonionic surfactant" described in Table 9, PEVE was replaced with "B: polymer" described in Table 9, and the pre-dispersion of microparticles OC-1 was replaced with "C: organic solid microparticles" described in Table 9. <Antifoaming Agent Sample C1> An antifoaming agent sample C1 was obtained by the same method as that for the antifoaming agent sample E1, except that MERVEILLE 30 was used instead of the pre-dispersion of fine particles OC-1. <Antifoaming Agent Sample C2> An antifoaming agent sample C2 was obtained by the same method as that for the antifoaming agent sample E4, except that MERVEILLE 30 was used instead of the pre-dispersion of fine particles OC-1. <Antifoaming Agent Sample C3> An antifoaming agent sample C3 was obtained by the same method as that for the antifoaming agent sample E5, except that MERVEILLE 30 was used instead of the pre-dispersion of fine particles OC-1. <Antifoaming Agent Sample C4> An antifoaming agent sample C4 was obtained by the same method as that of the antifoaming agent sample E1, except that MERVEILLE 30 was used instead of EMALEX RWIS-305 and PEVE. <Defoamer Sample C5> Defoamer Sample C5 was obtained by the same method as Defoamer Sample E2, except that MERVEILLE 30 was used instead of EMALEX RWIS-305 and PEVE. <Defoamer Sample C6> Defoamer Sample C6 was obtained by the same method as Defoamer Sample E3, except that MERVEILLE 30 was used instead of EMALEX RWIS-305 and PEVE. <Defoaming Agent Sample C7> As the defoaming agent sample C7, BYK-024 (manufactured by BYK) which is a mixture of silicone, hydrophobic fine particles, and polyglycol was used. <Antifoaming Agent Sample C8> As the antifoaming agent sample C8, Agitan 295 (manufactured by MUNZING CHEMIE GmbH, Germany), which is a mixture of hydrocarbon, hydrophobic silica, and an alkoxy compound, was used. <Defoamer Samples C9 to C14, Defoamer Sample C18> Defoamer Samples C9 to C14, and Defoamer Sample C18 were obtained by the same method as Defoamer Sample E1, except that Emalex RWIS-305 was replaced with "A: nonionic surfactant" or "nonionic surfactant (non-component A)" described in Table 11, and PEVE was replaced with "B: polymer" or "polymer (non-component B)" described in Table 11. <Defoamer Sample C15> Defoamer Sample C15 was obtained by the same method as Defoamer Sample E1, except that 27.5 parts of PEVE was replaced with 13.8 parts of Acrylic Polymer 4, the polymer (Acrylic Polymer 4) was diluted with 13.7 parts of methylpropylene glycol, and then mixed with the pre-dispersion of Emalex RWIS-305 and fine particles OC-1. <Defoamer Sample C16> Defoamer Sample C16 was obtained by the same method as Defoamer Sample E1, except that Elamex Rwis-305 was replaced with Elamex Rwis-330 (PEG-30 hydrogenated castor oil triisostearate, manufactured by Nippon Emulsion Co., Ltd.), 27.5 parts of PEVE was replaced with 13.8 parts of Acrylic Polymer 4, and the polymer (Acrylic Polymer 4) was diluted with 13.7 parts of methylpropylene glycol before mixing with the pre-dispersion of Elamex Rwis-330 and fine particles OC-1. <Defoamer Sample C17> 13.0 parts of FS1265-10000cst (fluorinated silicone manufactured by Doray Industries, Inc.) was diluted with 32.5 parts of methyl isobutyl ketone to obtain a polymer dilution. Next, 6.5 parts of Emalex Rwis-305 and the polymer dilution were placed in a 100 mL plastic cup. While stirring with a disperser, 13.0 parts of the pre-dispersion of fine particles OC-1 were added. The mixture was then stirred at 2000 rpm for 15 minutes to obtain Defoamer Sample C17. <Defoamer Sample C19> A 100 mL plastic cup was charged with 7.4 parts of Elamex RWIS-305, 27.2 parts of Durasyn 164 (polyα-olefin, component B, manufactured by INEOS Oligmers), and 0.7 parts of KF-96-50CS (polydimethylsiloxane, non-component B, manufactured by Shin-Etsu Chemical Co., Ltd.). While stirring with a disperser, 29.7 parts of the pre-dispersion of fine particles OC-1 was added. The mixture was then stirred and mixed at 2000 rpm for 15 minutes to obtain Defoamer Sample C19. <Defoamer Sample C20> A 100 mL plastic cup was charged with 1.2 parts of Sylophobic 100 (hydrophobic silica manufactured by Fuji Silicon Chemical Co., Ltd., not component C), 5.8 parts of Nipsil SS-30P (hydrophobic silica manufactured by Tosoh Silica Co., Ltd., not component C), and 93.0 parts of Cosmo Purspin G (hydrogenated paraffin wax manufactured by Cosmo Lubricants Co., Ltd.). The mixture was stirred at 3500 rpm for 15 minutes to obtain Defoamer Sample C20 (silica-containing defoamer). The methanol wetting value (M value) and volume average particle size of Sylophobic 100 and Nipsil SS-30P were also measured. The M value indicates the degree of hydrophobicity, with higher M values ​​indicating lower hydrophilicity. It is expressed as the volumetric ratio of the minimum amount of methanol required to uniformly disperse hydrophobic particles in a mixture of water and methanol. The M value is calculated using the following method. 0.2 g of a test sample (Sylophobic 100 and Nipsil SS-30P) is added to 50 mL of water in a 250 mL beaker. Methanol is then added dropwise from a burette until the test sample is completely suspended. The solution in the beaker is continuously stirred with a magnetic stirrer. The endpoint is defined as the point at which the test sample is completely uniformly suspended in the solution. The volumetric percentage of methanol in the liquid mixture in the beaker at this endpoint is defined as the M value. The volume average particle size is measured using a Microtrac MT-3000EXII / USVR laser diffraction particle size analyzer, circulating 2-propanol, to measure the 50% cumulative volume average particle size. The M values ​​and volume average particle sizes of Sylophobic 100 and Nipsil SS-30P measured as above are as follows: Sylophobic 100 M value: 60, volume average particle size: 2.4 μm Nipsil SS-30P M value: 60, volume average particle size: 17.5 μm <Defoamer Sample C21> A 100 mL plastic cup was charged with 3.4 parts of Emalex RWIS-305 and 12.5 parts of Durasyn 164. While stirring with a disperser, 13.6 parts of the pre-dispersion of fine particles OC-1 and 9.7 parts of defoamer sample C20 were added. The mixture was then stirred and mixed at 2000 rpm for 15 minutes to obtain defoamer sample C21. <Defoamer Sample C22> A 100 mL plastic cup was charged with 3.4 parts of Emulex RWIS-305, 12.5 parts of Durasyn 164, 10.2 parts of Merveille 30, and 2.8 parts of ethanol. While stirring with a disperser, 9.7 parts of Defoamer Sample C20 was added. The mixture was then stirred and mixed at 2000 rpm for 15 minutes to obtain Defoamer Sample C22. <Defoamer Sample C23> 1.2 parts of Sylophobic 100 (hydrophobic silica manufactured by Fuji Silicon Chemical Co., Ltd., non-component C), 5.8 parts of Nipsil SS-30P (hydrophobic silica manufactured by Tosoh Silica Co., Ltd., non-component C), 73.4 parts of Merveille 30, and 19.6 parts of ethanol were added and stirred at 2000 rpm for 15 minutes using a disperser to prepare a silica slurry. Next, a 100 mL plastic cup was charged with 4.6 parts of Emalex RWIS-305, 16.9 parts of Durasyn 164, 13.8 parts of Merveille 30, and 3.7 parts of ethanol. While stirring with a disperser, 13.1 parts of silica slurry was added. The mixture was then stirred at 2000 rpm for 15 minutes to obtain defoamer sample C23. <Defoamer Sample C24> After preparing a silica slurry in the same manner as for Defoamer Sample C23, a 100 mL plastic cup was charged with 4.6 parts of Emulex RWIS-305 and 16.9 parts of Durasyn 164. While stirring with a disperser, 18.5 parts of the pre-dispersion of fine particles OC-1 and 13.1 parts of the silica slurry were added. The mixture was then stirred and mixed at 2000 rpm for 15 minutes to obtain Defoamer Sample C24. <Defoamer Sample C25> In a 100 mL plastic cup were placed 7.5 parts of Emalex RWIS-305, 27.5 parts of Durasyn 164, 24.0 parts of Merveille 30, and 6.0 parts of ethanol, and the mixture was stirred and mixed at 2000 rpm for 15 minutes to obtain Defoamer Sample C25. The compositions of the defoaming agent samples prepared as described above are shown in Tables 5 to 11 below. [Table 5] Table 5 Composition of defoaming agent samples (Example E1 to Example E7) [Table 6] Table 6 Composition of defoaming agent samples (Example E8 to Example E18) [Table 7] Table 7 Composition of defoaming agent samples (Example E19 to Example E31) [Table 8] Table 8 Composition of defoaming agent samples (Example E32 to Example E44) [Table 9] Table 9 Composition of defoaming agent samples (Example E45 to Example E54) [Table 10] Table 10 Composition of Defoaming Agent Samples (Comparative Examples C1 to C8) [Table 11] Table 11 Composition of Defoaming Agent Samples (Comparative Examples C9 to C25) (Preparation of Water-Based Paint Compositions and Test Solutions) Two water-based paints (control (Blank)) were prepared according to the formulations shown in Tables 12 and 13. The water-based paints shown in Table 12 are open-dry paints (paints that dry at room temperature), while the water-based paints shown in Table 13 are calcined paints (paints that harden by heating). [Table 12] Table 12 Normally Dry Coating Formula (Control) [Table 13] Table 13 Sintering coating formula (control) <Preparation of Water-Based Paint Compositions with Dry-Dry Paint Formulations> 100 parts of the dry-dry paint listed in Table 12 were weighed into a 300 mL tall glass beaker. 1 part each of the defoamers E1 to E44 and C1 to C24 obtained as described above were added dropwise thereto while stirring at 1000 rpm for 1 minute. This gave the water-based paint compositions of Examples 1 to 44 (Table 14) and Comparative Examples 1 to 24 (Table 15). <Preparation of Test Liquids for Evaluation Tests of Always-Drying Paint Formulations> The water-based paint compositions of Examples 1 to 44 and Comparative Examples 1 to 24, obtained as described above, were dispersed at 2000 rpm using a disperser equipped with a 5 cm Φ Cowles blade (pre-high shear step). Regarding the dispersion time, a dispersion liquid dispersed for 5 minutes (hereinafter sometimes referred to as a "5-minute dispersion") and a dispersion liquid dispersed for 20 minutes (hereinafter sometimes referred to as a "20-minute dispersion") were prepared for each water-based paint composition. The 5-minute dispersion and 20-minute dispersion performed in this step correspond to a short high shear step and a long high shear step, respectively. The test liquid dispersed for 20 minutes with a higher specific gravity recovery rate exhibited superior shear resistance. <Preparation of Water-Based Coating Compositions for Baking Coating Formulations: For 5-Minute Dispersions> 100 parts of the baking coating of Table 13 were weighed into a 300 mL tall glass beaker. One part each of Defoamer E9, E11 to E13, E15, E18, E24, E27, E32, E33, E45 to E54, and Defoamer C15, C20, C23, and C25, obtained as described above, were added dropwise thereto while stirring at 1000 rpm for one minute. This gave water-based coating compositions (for 5-minute dispersions) of Examples 45 to 64 and Comparative Examples 25 to 28 (see Table 16). <Preparation of Test Solution (5-Minute Dispersion) for Evaluation Test of Sintered Coating Formulations> The aqueous coating compositions of Examples 45-64 and Comparative Examples 25-28, obtained as described above, were dispersed at 2000 rpm for 5 minutes using a disperser equipped with a 5 cm Φ Cowles blade (preliminary high-shear step). The 5-minute dispersion performed in this step corresponds to a short high-shear step. <Preparation of Water-Based Coating Compositions for Baking Coating Formulations: For 20-Minute Dispersion> 100 parts of the baking coating of Table 13 were weighed into a 300-mL tall glass beaker. One part each of Defoamer E9, E11 to E13, E15, E18, E24, E27, E32, E33, E45 to E54, and Defoamer C15, C20, C23, and C25, obtained as described above, were added dropwise thereto while stirring at 1000 rpm for one minute. This gave water-based coating compositions (for 20-minute dispersions) for Examples 45 to 64 and Comparative Examples 25 to 28 (see Table 16). <Preparation of Test Solutions (20-Minute Dispersions) for Baking Coating Formulation Evaluation Tests> The water-based coating compositions of Examples 45-64 and Comparative Examples 25-28, obtained as described above, were dispersed at 2000 rpm for 20 minutes using a disperser equipped with a 5 cm Ø Cowles blade (preliminary high-shear step). The 20-minute dispersion performed in this step corresponds to a long high-shear step. Test solutions dispersed for 20 minutes exhibited higher specific gravity recovery rates and exhibited superior shear resistance. The dispersions (5-minute dispersions and 20-minute dispersions) of Examples 1 to 64 and Comparative Examples 1 to 28 obtained in the above pre-high shear step were transferred to a 200 mL plastic cup and degassed for 2 minutes using a Rentaro ARE-310 degasser (manufactured by Thinky Co., Ltd.) in the degassing mode. After standing at room temperature for more than 2 hours, the test solutions of the Examples and Comparative Examples were prepared (degassing step). [Evaluation Method] The water-based coating compositions of Examples 1 to 64 and Comparative Examples 1 to 28 obtained as described above were subjected to evaluation tests as follows. (Evaluation of Shear Resistance) 100 parts of the test solution obtained in the degassing step were transferred to a 200 mL plastic cup and dispersed at 2000 rpm for 5 minutes using a disperser equipped with a Cowles blade to foam (foaming step). The dispersion process in this step refers to the foaming step. The pre-high shear step and the foaming step were separated to ensure that the foaming conditions were the same. <Evaluation of the formulation of the normally dry paint> Use a specific gravity cup to measure the specific gravity of the test liquid 1 minute and 5 minutes after foaming, and calculate the percentage of the specific gravity of the test liquid before foaming as the specific gravity recovery rate. The closer the specific gravity recovery rate is to 100%, the better the defoaming properties. The 1 minute and 5 minutes used in calculating the specific gravity recovery rate are both the time required for the specific gravity to recover. The specific gravity recovery rate after 1 minute is evaluated as an indicator mainly related to the anti-foaming properties, and the specific gravity recovery rate after 5 minutes is evaluated as an indicator mainly related to the defoaming properties. Specific gravity recovery rate (after 1 minute) = (specific gravity of the test liquid 1 minute after foaming) / (specific gravity of the test liquid before foaming) × 100 [%] Specific gravity recovery rate (after 5 minutes) = (specific gravity of the test liquid 5 minutes after foaming) / (specific gravity of the test liquid before foaming) × 100 [%] Shear resistance was evaluated according to the following criteria. If both the specific gravity recovery rate (1 minute) and the specific gravity recovery rate (5 minutes) in the test solution dispersed for 5 minutes were rated C or higher, and at least one of the specific gravity recovery rate (1 minute) and the specific gravity recovery rate (5 minutes) in the test solution dispersed for 20 minutes was rated C or higher, the test solution was judged to have the shear resistance required by the present invention. <Evaluation Criteria for Specific Gravity Recovery Rate (1 Minute)> Specific Gravity Recovery Rate (1 Minute) [%] 95% or more: Very excellent (A) Specific Gravity Recovery Rate (1 Minute) [%] 85% or more and less than 95%: Excellent (B) Specific Gravity Recovery Rate (1 Minute) [%] 75% or more and less than 85%: Acceptable effect (C) Specific Gravity Recovery Rate (1 Minute) [%] less than 75%: Poor defoaming effect (D) <Evaluation Criteria for Specific Gravity Recovery Rate (5 Minutes)> Specific Gravity Recovery Rate (5 Minutes) [%] 98% or more: Very excellent (A) Specific Gravity Recovery Rate (5 Minutes) [%] 90% or more and less than 98%: Excellent (B) Specific Gravity Recovery Rate (5 Minutes) [%] 80% or more and less than 90%: Acceptable effect (C) Specific Gravity Recovery Rate (5 Minutes) [%] less than 80%: Poor defoaming effect (D) <Evaluation of sintering coating formulation> Use a specific gravity cup to measure the specific gravity of the test liquid 1 minute and 5 minutes after foaming, and calculate the percentage of the specific gravity of the test liquid before foaming as the specific gravity recovery rate. The closer the specific gravity recovery rate is to 100%, the better the defoaming properties. When calculating the specific gravity recovery rate, the 1 minute and 5 minutes are both the time required for the specific gravity to recover. The specific gravity recovery rate after 1 minute is evaluated as an indicator mainly related to the anti-foaming property, and the specific gravity recovery rate after 5 minutes is evaluated as an indicator mainly related to the defoaming property. Specific gravity recovery rate (after 1 minute) = (specific gravity of the test liquid 1 minute after foaming) / (specific gravity of the test liquid before foaming) × 100 [%] Specific gravity recovery rate (after 5 minutes) = (specific gravity of the test liquid 5 minutes after foaming) / (specific gravity of the test liquid before foaming) × 100 [%] Shear resistance was evaluated according to the following criteria. If both the specific gravity recovery rate (1 minute) and the specific gravity recovery rate (5 minutes) in the test solution dispersed for 5 minutes were rated C or higher, and at least one of the specific gravity recovery rate (1 minute) and the specific gravity recovery rate (5 minutes) in the test solution dispersed for 20 minutes was rated C or higher, the test solution was judged to have the shear resistance required by the present invention. <Evaluation Criteria for Specific Gravity Recovery Rate (1 Minute)> Specific Gravity Recovery Rate (1 Minute) [%] of 99.5% or more: Very excellent (A) Specific Gravity Recovery Rate (1 Minute) [%] of 95% or more and less than 99.5%: Excellent (B) Specific Gravity Recovery Rate (1 Minute) [%] of 90% or more and less than 95%: Acceptable effect (C) Specific Gravity Recovery Rate (1 Minute) [%] less than 90%: Poor defoaming effect (D) <Evaluation Criteria for Specific Gravity Recovery Rate (5 Minutes)> Specific Gravity Recovery Rate (5 Minutes) [%] of 99.5% or more: Very excellent (A) Specific Gravity Recovery Rate (5 Minutes) [%] of 95% or more and less than 99.5%: Excellent (B) Specific Gravity Recovery Rate (5 Minutes) [%] of 90% or more and less than 95%: Acceptable effect (C) Specific Gravity Recovery Rate (5 Minutes) [%] less than 90%: Poor defoaming effect (D) Furthermore, since the foaming properties and specific gravity of the paint without defoamer (control) vary depending on the paint formulation, the evaluation criteria for shear resistance in the baked paint formulation using ACD-2001 differ from those in the normally dry paint formulation using AP-3900. (Evaluation of Coating Appearance) The appearance of the coating films obtained by applying the test solutions in the dry paint formulation and the test solutions in the baked paint formulation on a glass plate, followed by drying and baking was evaluated. <Evaluation of Dry Paint Formulations> The test solution obtained in the degassing step was applied to a glass plate using a bar coater #42. The coating was dried at room temperature for one day, and the appearance of the coating film was evaluated. The coating appearance was evaluated according to the following criteria: ○: No fish-eye-like pinholes were observed in the coating film ○-: Three or fewer pits were observed in the coating film △: Three or fewer fish-eye-like pinholes were observed in the coating film X: More than three fish-eye-like pinholes or noticeable uneven spots were observed in the coating film <Evaluation of Sintered Coating Formulation> The test solution obtained in the degassing step was applied to a glass plate using a 200 μm coater. Film formation was performed under the following conditions: room temperature for 5 minutes, preheating at 80°C for 5 minutes, and sintering at 140°C for 30 minutes. The coating appearance was then evaluated. The coating appearance was evaluated according to the following criteria: ○: No fisheye-like pinholes were observed in the coating film ○-: Three or fewer pits were observed in the coating film △: Three or fewer fisheye-like pinholes were observed in the coating film ×: More than three fisheye-like pinholes or noticeable uneven spots were observed in the coating film (Evaluation of coating properties) Regarding coating properties, the presence or absence of coating obstruction risk is determined by whether the water-based coating composition contains silicone compounds ("presence of silicone"). No risk of coating obstruction due to silicone: No (no silicone compounds) Presence of risk of coating obstruction due to silicone: Yes (contains silicone compounds) [Evaluation Results] The results of the performance evaluations described above are shown in Tables 14 to 16. Furthermore, for the Blank sample (sample without defoamer), the specific gravity recovery rate (1 minute) and specific gravity recovery rate (5 minutes) data reported in the "5-minute dispersion" column of Tables 15 and 16 are the results of foaming the sample in the foaming step without the pre-high shear step to determine the specific gravity. Furthermore, for the control sample, after a 20-minute pre-high shear step, significant foaming during the pre-high shear step was observed, resulting in the discontinuation of the shear resistance evaluation test. [Table 14] Table 14 Evaluation results of dry coating formulations (Examples 1 to 44) Table 15 Evaluation results of dry paint formulations (Comparative Examples 1 to 24, control) *Results evaluated without pre-high shear step [Table 16] Table 16 Evaluation results of baking paint formulations (Examples 45 to 64, Comparative Examples 25 to 28, Control) *Results evaluated without pre-high shear step The evaluation results of the shear resistance, coating appearance and coating properties of the water-based coating compositions of Examples 1 to 64 all showed the performance required by the present invention. Comparison of Examples 1, 9, 12, and 16 shows that when the HLB of the nonionic surfactant (A) is 2 or more, the coating appearance tends to be particularly excellent. Comparison among Examples 1, 20, and 23 reveals that when the SP value of the polymer (B) is 9.5 or less, the shear resistance is particularly excellent. Comparison of Examples 1, 21, 27, and 31 reveals that when the weight average molecular weight of the polymer (B) is 300,000 or less, shear resistance and coating appearance are particularly excellent. Comparison of Examples 1, 34, 36, and 38 revealed that when the aspect ratio of the organic solid fine particles (C) was within the range of 2.0 to 11, shear resistance was particularly excellent. On the other hand, Comparative Examples 1 to 3 and 25, which did not contain organic solid fine particles (C) as a defoaming agent component, and Comparative Examples 4 to 6, which did not contain nonionic surfactant (A) and polymer (B), all showed poor shear resistance. Furthermore, separation of the defoaming agent occurred in the water-based coating composition of Comparative Example 3. Furthermore, Comparative Example 25 replaces the organic solid fine particles (C) with Merveille 30. Furthermore, Comparative Examples 7, 17, and 19, which contained silicone compounds as defoaming agents, and Comparative Examples 8, 20, and 24, which contained hydrophobic silica, exhibited poor coating appearance. Furthermore, Comparative Examples 7, 17, and 19, which also contained silicone compounds, also presented a risk of coating impairment due to the presence of silicone compounds. In Comparative Examples 9 to 14, which contained a surfactant (non-component A) having an HLB exceeding 16 as a nonionic surfactant, the defoamer composition (defoamer sample) separated, and therefore subsequent tests were discontinued. Furthermore, Comparative Examples 15 to 19, which contain a polymer that does not correspond to the polymer (B) of the present invention (non-component B), exhibit poor shear resistance or poor coating appearance. In particular, Comparative Examples 17 and 19, which contain a silicone compound as a polymer, exhibit excellent shear resistance but poor coating appearance. In addition, Comparative Examples 20 to 24 containing inorganic solid fine particles (non-component C) as solid fine particles were excellent in shear resistance, but had poor coating appearance. none none

Claims

1. A defoamer composition for use in water-based coatings, the defoamer composition being characterized by comprising: a nonionic surfactant (A) having at least one hydrophilic portion selected from the group consisting of ethylene glycol, polyethylene glycol, and polyol portions, and having a hydrophilic-lipophilic balance value of 1 to 16; a polymer (B) lacking the hydrophilic portion, having a solubility parameter value of 7.5 to 12, and a weight average molecular weight of 400 to 1,000,000; and organic solid particles (C) being in a solid state in the defoamer composition at 25°C, wherein, when the total mass of all components in the defoamer composition is set to 100% by mass, the content of the nonionic surfactant (A) is 5% to 80% by mass, the content of the polymer (B) is 10% to 90% by mass, and the content of the organic solid particles (C) is 0.1% to 10% by mass.

2. The defoamer composition as claimed in claim 1, wherein the nonionic surfactant (A) is one or more selected from the group consisting of ethylene glycol aliphatic ethers, polyoxyalkylene aliphatic ethers, polyoxyalkylene aromatic ethers, polyoxyalkylene fatty acid esters, alkylene oxide addition derivatives of castor oil, alkylene oxide addition derivatives of hydrogenated castor oil, polyoxyalkylene polyol ethers, polyol fatty acid esters, alkylene oxide addition derivatives of polyol fatty acid esters, polyoxyalkylene alkylamides, acetylenide glycol and its derivatives, alkylene oxide addition derivatives of acetylenide glycol, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers.

3. The defoamer composition as claimed in claim 1, wherein the polymer (B) is one or more polymers selected from the group consisting of polyvinyl alkyl ethers, polybutadiene, polybutene, polyisoprene, polyalphaolefins, poly(meth)acrylates, copolymers of diesters, polyvinyl fatty acids, copolymers of (meth)acrylates and vinyl fatty acids, and polyalkylene glycol derivatives, wherein, The polyalkylene glycol derivative does not have the ethylene glycol portion, the polyethylene glycol portion, and the polyol portion, and the weight average molecular weight of the polyalkylene glycol derivative is 400 to 1,000,000.

4. The defoamer composition as claimed in claim 1, wherein the organic solid particles (C) are one or more solid particles selected from the group consisting of amide, urea, polyethylene, oxidized polyethylene, acid-modified polyethylene, and hydrogenated castor oil.

5. The defoamer composition as claimed in claim 4, wherein the acetylamine is a fatty acid diacetylamine obtained by reacting fatty acids with diamines, wherein the fatty acids are selected from the group consisting of alkyl fatty acids and hydroxy fatty acids and contain at least one or more hydroxy fatty acids, and the diamines contain one or more diamines selected from the group consisting of alkyl diamines having 2 to 6 carbon atoms and m-phenylenediamine.

6. The defoamer composition as claimed in claim 1, wherein the aspect ratio of the crystals of the organic solid particles (C) is 1.1 to 100.

7. The defoamer composition as claimed in claim 1 further includes an organic medium (D) that is liquid at 25°C other than water and does not have the hydrophilic part in its molecule, the organic medium (D) having a weight average molecular weight of less than 400, and the content of the organic medium (D) being 0.5% to 70% by mass when the total mass of all components in the defoamer composition is set to 100% by mass.

8. The defoamer composition as claimed in claim 7, wherein the organic medium (D) is one or more selected from the group consisting of hydrocarbon oils, alcohols, glycol ethers and glycol esters.

9. The defoamer composition as described in claim 1 does not contain silicone compounds.

10. A water-based coating composition, characterized in that it comprises an antifoaming composition as described in any one of claims 1 to 9, and a water-based resin.

11. The water-based coating composition as claimed in claim 10, wherein the content of the defoamer composition is 0.1% to 5% by mass relative to the water-based coating composition.

12. An article having a coating film formed by a coating agent comprising a defoamer composition, said coating film being obtained by coating the surface of the article with a coating agent comprising a defoamer composition as described in any one of claims 1 to 9.