Water-based paint composition

Abstract

To provide a water-based paint composition containing phthalocyanine blue and phthalocyanine green, which has little color variation and little roughness of a coating film. [Solution] This is an aqueous paint composition containing at least one of phthalocyanine blue and phthalocyanine green, a dispersant, a water-soluble resin, and water, wherein the dispersant contains 3% by mass or more of a polyacrylate-based dispersant relative to the total mass of the phthalocyanine blue and phthalocyanine green.

Description

[Technical Field]

[0001] The present invention relates to a water-based paint composition. [Background technology]

[0002] Aqueous paint compositions generally contain water, a water-soluble resin, a pigment, and a dispersant. Patent Document 1, for example, describes an example of this type of technology, which describes an aqueous paint composition containing a pigment, a film-forming resin, a water-soluble resin, and a surfactant. The aqueous paint composition of Patent Document 1 is suitable as a so-called acrylic paint, and it is disclosed that aqueous paint compositions with specific physical properties suppress medium separation and have good spreadability. An example of Patent Document 1 describes an aqueous paint composition containing a wetting agent, a viscosity modifier, a pigment, and a resin emulsion, and further containing a polycarboxylic acid surfactant and a phosphate ester as dispersants.

[0003] Patent Document 2 discloses an aqueous paint composition suitable for drawing with a finger. The aqueous paint composition of Patent Document 2 contains a pigment, left-handed optically rotatory gum arabic, a montmorillonite clay mineral, a wetting agent, denatonium cations, and water. The denatonium cations are thought to be involved in the dispersion of the montmorillonite clay mineral.

[0004] Patent Document 3 discloses an aqueous paint composition containing two types of cellulose ether resins with different viscosities and shear stresses within a specific range. The aqueous paint composition of Patent Document 3 is an aqueous paint composition that reduces coating unevenness and leaves little marks on the coating surface. The examples of Patent Document 3 disclose an aqueous paint composition containing water, glycerin, a cellulose ether resin, a pigment, and a polyoxyethylene distyrenated phenyl ether surfactant and a sodium naphthalene sulfonate formalin condensate as surfactants. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-46519 [Patent Document 2] Japanese Patent Application Publication No. 2017-61677 [Patent Document 3] Patent No. 6543427 Summary of the Invention [Problem to be solved by the invention]

[0006] Various pigments are used in water-based paints depending on the color, but the tinting strength varies depending on the type of pigment. Phthalocyanine blue and phthalocyanine green have high tinting strength, but care has been required to produce water-based paints of consistent quality with no variation in color or coating condition. Based on this situation, one of the objects of the present invention is to provide a water-based paint composition containing phthalocyanine blue or phthalocyanine green that has little color variation and produces a coating with little roughness. [Means for solving the problem]

[0007] The aqueous paint composition according to the present disclosure contains at least one of phthalocyanine blue and phthalocyanine green, a dispersant, a water-soluble resin, and water, wherein the dispersant contains 3% by mass or more of a polyacrylate-based dispersant relative to the total mass of the phthalocyanine blue and phthalocyanine green.

[0008] During the course of research into aqueous paint compositions, researchers discovered that paints containing phthalocyanine blue or phthalocyanine green are prone to color variation, leading to further research into color variation. As a result of this research, it was believed that color variation is related to coarse pigment particles that were not completely crushed during the manufacturing process. It was also believed that these coarse particles are a cause of roughness in paint films. Further research revealed that the use of polyacrylate-based dispersants as dispersants in aqueous paint compositions containing phthalocyanine blue or phthalocyanine green improves dispersibility, particularly by minimizing the impact on color change even when mechanical dispersing forces change during the manufacturing process, allowing for the stable production of aqueous paints with minimal color variation. Furthermore, it was discovered that such aqueous paint compositions have reduced coarse particles, making them less likely to produce roughness in paint films.

[0009] In the aqueous paint composition, the proportion by mass of the polyacrylate dispersant relative to the total mass of phthalocyanine blue and phthalocyanine green is preferably 3% by mass or more and 35% by mass or less.

[0010] In the aqueous paint composition, the dispersant preferably further comprises a dispersant other than a polyacrylate-based dispersant.

[0011] In the aqueous paint composition, the proportion of the total mass of phthalocyanine blue and phthalocyanine green relative to the total mass of the aqueous paint composition may be 0.1 mass % or more and 20 mass % or less.

[0012] A green paint according to the present disclosure may consist of the water-based paint composition. [Effects of the Invention]

[0013] According to the aqueous paint composition of the present disclosure, it is possible to provide an aqueous paint composition that contains phthalocyanine blue or phthalocyanine green, has little color variation, and has little roughness in the state of the paint film. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0013] The following is a specific description of an embodiment of the aqueous paint composition according to the present disclosure. The aqueous paint composition according to the present disclosure is an aqueous paint composition containing at least one of phthalocyanine blue and phthalocyanine green, a dispersant, a water-soluble resin, and water, wherein the dispersant comprises a polyacrylate-based dispersant. The aqueous paint composition according to the present disclosure may be a water-soluble watercolor paint, or may be an acrylic paint, the coated surface of which becomes water-insoluble after drying.

[0015] (pigment) The aqueous paint composition according to the present disclosure contains at least one of phthalocyanine blue and phthalocyanine green as a color pigment. It also contains an extender pigment. Both the color pigment and the extender pigment are powder components that do not dissolve in the liquid phase of the aqueous paint composition but are dispersed as solids.

[0016] (color pigments) The color pigment is added for the purpose of coloring the paint and controlling covering power. The aqueous paint composition according to the present disclosure is intended to provide a green-based paint and contains at least one of phthalocyanine blue and phthalocyanine green, or both, as the color pigment. The color pigment may contain only at least one of phthalocyanine blue and phthalocyanine green, or both, or may contain an additional color pigment in addition to phthalocyanine blue and / or phthalocyanine green. The additional color pigment may be any one or more of an organic raw material, an inorganic pigment, a lake pigment, and a fluorescent pigment.

[0017] The colored pigment that can be included with phthalocyanine blue and / or phthalocyanine green is not particularly limited, but may be, for example, a yellow pigment. The paint composition according to the present disclosure is suitable for use as a green paint, and green paints often also contain a yellow pigment. Examples of yellow pigments include organic yellow pigments such as azo yellow pigments, monoazo yellow pigments, disazo yellow pigments, pyrazolone yellow pigments, benzimidazolone yellow pigments, quinoxaline yellow pigments, metal complex yellow pigments, quinophthalone yellow pigments, flavanthrone yellow pigments, and anthraquinone yellow pigments. Examples of inorganic yellow pigments include cadmium yellow, cobalt yellow, titanium yellow (including yellow composite oxides such as titanium-nickel-antimony oxide, titanium-nickel-barium oxide, and titanium-chromium-antimony oxide), barium yellow, and vanadium zirconium yellow.

[0018] More specific examples include Hansa Yellow (Pigment Yellow 1), Hansa Yellow 10G (Pigment Yellow 3), Tartrazine Lake, Benzidine Yellow G, Benzidine Yellow 5G, Benzidine Yellow 8G, Permanent Yellow NCG, Quinoline Yellow, Isoindolinone Yellow G, Isoindolinone Yellow R, Isoindolinone Yellow 6G, Isoindoline Yellow R, and Isoindoline Yellow G. Of these, one or more can be used.

[0019] Furthermore, the aqueous paint composition according to the present disclosure may contain other pigments in addition to those mentioned above. Examples of other pigments include, but are not limited to, aniline black, isoindolinone orange, permanent orange 2G, induthrene brilliant orange GK, Balkan orange, pyrazoline orange TMP, benzine orange, perinone orange, isoindoline orange, quinacridone orange, DPP orange, permanent brown FG, perinone red, isoindoline red, DPP red, permanent red 4R, fire red, brilliant carmine BS, pyrazolone red, bordeaux 5B, thioindigo red, naphthol carmine HR, naphthol red F5RK, naphthol red F3RK-70, permanent red FGR, permanent carmine FB, permanent red 2B, brilliant carmine 6B, Examples of pigments include Watching Red, Permanent Red FRLL, Carmine Lake, Carmine FBB, Fast Violet B, Methyl Violet Lake, Indanthrene Violet, Indanthrene Blue, Acid Green Lake, Dichloroquinacridone Red, Quinacridone Magenta, Dichloroquinacridone Magenta, Quinacridone Violet, Quinacridone Scarlet, Dioxazine Violet, Perylene Red, Perylene Scarlet, Perylene Brown, Perylene Violet, DPP Scarlet, DPP Rubin, Quinacridone Maroon, Perylene Vermilion, Perylene Maroon, Perylene Black, Alkali Blue, Fast Sky Blue, Victoria Blue Lake, Marcalite Green Lake, and Pigment Green B.

[0020] The ratio of the total mass of the color pigments to the total mass of the aqueous paint composition is not limited as long as the effects of the present disclosure are obtained, but may be 60% by mass or less, and preferably 5% by mass or more and 40% by mass or less. Furthermore, the ratio of the total mass of the phthalocyanine blue and phthalocyanine green to the total mass of the aqueous paint composition is not limited as long as the effects of the present disclosure are obtained, but preferably 0.1% by mass or more and 20% by mass or less. When the color pigment is 5% by mass or more, color development is obtained. When the color pigment is 60% by mass or less, there is little risk of excessive viscosity, and an aqueous paint with good spreadability is obtained.

[0021] (extender pigment) Extender pigments are added to adjust coloring strength and to control the covering power, viscosity, etc. of the paint. There are no particular restrictions on the extender pigment, but examples include metal sulfates such as calcium sulfate and barium sulfate (alkaline earth metal sulfates, transition metal sulfates, etc.), metal carbonates such as calcium carbonate and magnesium carbonate (carbonates including alkaline earth metal carbonates, transition metal carbonates, etc.), clay minerals such as kaolin and bentonite, and silicates including silicic acid, aluminum silicate, and zeolite. Of these, it is preferable to include at least one of calcium carbonate, sodium aluminosilicate, and bentonite.

[0022] The content of the extender pigment is not particularly limited as long as the effects of the present disclosure can be obtained, but it may be 60% by mass or less, and preferably 5% to 40% by mass of the aqueous paint composition. If it is 5% by mass or more, the viscosity is low and there is little risk of deterioration in storage stability. In addition, the effect of controlling viscosity and covering power can be obtained. If it is 40% by mass or less, there is little risk of impairing color development and there is little risk of the viscosity becoming too high.

[0023] The total amount of color pigment and extender pigment in the aqueous paint composition is not particularly limited as long as the effects of the present disclosure can be obtained, but it is preferably 35% by mass or more and 50% by mass or less. The color pigment and extender pigment are powder components in the aqueous paint composition, and when the powder components are in this range, a composition can be obtained that has an appropriate viscosity for an aqueous paint and in which the powder is stably dispersed in the base component.

[0024] (Water-soluble resin) The aqueous paint composition according to the present disclosure contains a water-soluble resin. The water-soluble resin is included in the aqueous paint composition as a viscosity modifier. The water-soluble resin is also added to disperse the pigment and to fix the paint to the surface. As the water-soluble resin, known substances used in conventional aqueous paint compositions can be used. Specific examples of the water-soluble resin include cellulose-based water-soluble resins, gum arabic, dextrin, polyvinyl alcohol, polyvinylpyrrolidone, etc.

[0025] The cellulose-based water-soluble resin has the molecular formula (C6H 10 O5) n The water-soluble cellulose resin is a resin in which some or all of the hydroxy groups of cellulose, a polysaccharide represented by the formula (I), have been converted to ether bonds. Examples of the cellulose-based water-soluble resin include cellulose ether-based water-soluble resins, such as carboxyalkyl cellulose, hydroxyalkyl cellulose, hydroxydialkyl cellulose, and alkyl cellulose alkyl ether. Of these, one or more of carboxyalkyl cellulose, hydroxyalkyl cellulose, hydroxyalkyl alkyl cellulose, and alkyl cellulose can be used.

[0026] More specifically, examples of carboxyalkyl celluloses include carboxymethyl cellulose (CMC), carboxyethyl cellulose, and carboxypropyl cellulose. Examples of hydroxyalkyl celluloses include hydroxyethyl cellulose. Examples of hydroxyalkyl alkyl celluloses include hydroxymethyl ethyl cellulose (methylhydroxyethyl cellulose) and hydroxymethyl propyl cellulose (methylhydroxypropyl cellulose). Examples of alkyl celluloses include methyl cellulose, ethyl cellulose, ethylmethyl cellulose, and propyl cellulose. In all cases, salt forms are also included. Among these, hydroxyethyl cellulose and sodium carboxymethyl cellulose are preferably used.

[0027] The content of the water-soluble resin composition is not particularly limited as long as the effects of the present disclosure can be obtained, but may be, for example, 0.2 to 2% by mass, and more preferably 0.3 to 0.8% by mass, relative to the total mass of the aqueous paint composition. If the content of the water-soluble resin composition is 0.2% by mass or more, the necessary viscosity can be imparted to the aqueous paint composition, and good storage stability can be achieved. If the content of the water-soluble resin composition is 2% by mass or less, the viscosity will not increase too much, and the paint can have good spreadability.

[0028] (resin emulsion) The aqueous paint composition according to the present disclosure may contain a resin component such as an acrylic resin. When a resin emulsion is contained, it can constitute a so-called acrylic paint, which forms a water-insoluble coating film after drying. The resin component is added for the purposes of fixing the paint to the painting surface and imparting water resistance and durability to the paint after drying. The resin component is typically added to the aqueous paint composition in the form of an emulsion. Examples of resin emulsions include acrylic resin emulsions, styrene-acrylic resin emulsions, and vinyl acetate resin emulsions.

[0029] Specific examples of acrylic resin emulsions include acrylic acid ester copolymer resin emulsions, acrylic acid alkyl ester copolymer resin emulsions, methacrylic acid ester copolymer resin emulsions, and methacrylic acid alkyl ester copolymer resin emulsions. Specific examples of styrene-acrylic resin emulsions include styrene-acrylic acid ester copolymer resin emulsions and styrene-methacrylic acid copolymer resin emulsions. Specific examples of vinyl acetate resin emulsions include vinyl acetate-acrylic acid ester copolymer resin emulsions and vinyl acetate resin emulsions. These resin emulsions can be used alone or in combination of two or more. Of these, acrylic acid ester copolymers and vinyl acetate-acrylic acid ester copolymers are preferably used.

[0030] The content of the resin component is not particularly limited as long as the effects of the present disclosure can be obtained. For example, the content of the resin emulsion is preferably 5 to 40% by mass, and more preferably 15 to 20% by mass, of the total mass of the aqueous paint composition. If the content of the resin emulsion is 5% by mass or more, water resistance and friction transferability (resistance to color transfer when the painted surface is rubbed) can be obtained. If the content of the resin emulsion is 40% by mass or less, a decrease in coverage and the generation of gloss can be suppressed. The content (solid content) of the resin component in the resin emulsion varies depending on the raw materials used, but generally, the solid content is approximately 40% to 60%. The content of the resin component, as solid content, is preferably 2.5 to 20% by mass, and more preferably 7.5 to 10% by mass, of the total mass of the aqueous paint composition.

[0031] The aqueous paint composition according to the present disclosure contains a polyacrylate-based dispersant (specifically, for example, polyacrylate) as a dispersant, but the polyacrylate used as a dispersant and the acrylic polymer in the acrylic resin emulsion typically have different molecular weights and can be separated by centrifugation. In general, the acrylic polymer contained in the acrylic resin emulsion has a higher molecular weight than the polyacrylate used as a dispersant. The acrylic polymer in the acrylic resin emulsion settles during centrifugation, while the polyacrylate used as a dispersant is obtained as a component present in the aqueous phase (supernatant). Furthermore, the polyacrylate used in the polyacrylate-based dispersant is water-soluble, while the acrylic polymer used in the acrylic resin emulsion is water-insoluble.

[0032] (dispersant) The aqueous paint composition according to the present disclosure contains a dispersant to disperse the pigment and prevent particle aggregation. One of the characteristics of the aqueous paint composition according to the present disclosure is that it contains a polyacrylate-based dispersant. It is also preferable to contain other types of dispersants in addition to the polyacrylate-based dispersant. Examples of dispersants other than polyacrylate-based dispersants include low-molecular-weight dispersants such as surfactants. Polyacrylate-based dispersants may be high-molecular-weight dispersants such as acrylic acid copolymers. Known surfactants used in conventional aqueous paint compositions can be used as surfactants. Examples include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0033] Examples of polyacrylate-based dispersants include those containing components such as styrene-acrylic acid copolymer, styrene-acrylic acid-acrylic acid ester copolymer, styrene-methacrylic acid copolymer, or styrene-methacrylic acid-acrylic acid ester copolymer. When a high-molecular-weight dispersant (resin dispersant) such as a polyacrylate-based copolymer is used as the dispersant, the resin dispersant may be a copolymer resin having a hydrophilic portion and a hydrophobic portion in the molecule, specifically, a maleic acid-based dispersant, a sulfonic acid-based dispersant, or the like, in addition to a polyacrylate-based dispersant. When a polyacrylate-based dispersant is used, the weight-average molecular weight of the dispersant is not particularly limited; for example, a dispersant having a weight-average molecular weight of about 1,000 to 100,000 of the polymer constituting the dispersant can be used.

[0034] Examples of maleic acid-based dispersants include those containing a styrene-maleic acid copolymer, an acrylic acid ester-maleic acid copolymer, etc. Examples of sulfonic acid-based dispersants include those containing an acrylic acid ester-styrene sulfonic acid copolymer, a styrene-methacrylic acid sulfonic acid copolymer, an acrylic acid ester-allyl sulfonic acid copolymer, or salts thereof.

[0035] Examples of surfactants that can be used in combination with polyacrylate dispersants include the following. Examples of nonionic surfactants include polyoxyethylene ether-type nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkylphenyl ethers, polyhydric alcohol fatty acid esters, polyoxyethylene ethers of polyhydric alcohol fatty acid esters, etc. When a polyacrylate-based dispersant and a surfactant are used in combination, it is preferable to combine the polyacrylate-based dispersant and the nonionic surfactant.

[0036] Specific examples of the anionic surfactant include phosphate ester-type anionic surfactants such as alkyl phosphate ester salts, polyoxyalkylene alkyl phosphate ester salts, polyoxyalkylene alkylphenyl phosphate ester salts, and glycerin fatty acid ester monophosphate ester salts; carboxylic acid-type anionic surfactants such as alkyl ether carboxylate salts, polyoxyalkylene ether carboxylate salts, alkyl (or alkenyl) amide ether carboxylate salts, and acylaminocarboxylate salts; sulfofatty acid ester salts such as dioctyl sodium sulfosuccinate; higher alcohol sulfate ester salts; and polyoxyethylene alkylphenyl ether sulfate ester salts.

[0037] Examples of cationic surfactants include alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkylbenzyldimethylammonium salts. Examples of amphoteric surfactants include alkyldimethylamine oxides and alkylcarboxybetaines. The surfactants can be used alone or in combination of two or more.

[0038] The content of the dispersant is not particularly limited as long as the effects of the present disclosure can be obtained, but for example, it may be 0.1% by mass or more and 3% by mass or less, and more preferably 0.3% by mass or more and 1.5% by mass or less, relative to the total mass of the aqueous paint composition. If the content of the dispersant is 0.1% by mass or more, the function as a dispersant can be ensured and deterioration of storage stability can be suppressed. If the content of the surfactant is 3% by mass or less, foaming due to a decrease in surface tension can be suppressed and deterioration of covering power and viscosity due to an excess of surfactant can be suppressed.

[0039] Furthermore, the content ratio of the polyacrylate dispersant relative to the total mass of the aqueous paint composition is not particularly limited as long as the effects of the present disclosure can be obtained, but for example, it may be from 0.1% to 1% by mass relative to the total mass of the aqueous paint composition, and more preferably from 0.3% to 0.5% by mass.

[0040] Furthermore, the content of the polyacrylate dispersant relative to the total mass of phthalocyanine blue and phthalocyanine green is 3% by mass or more and 35% by mass or less, and preferably 3% by mass or more and 15% by mass or less. It is believed that the inclusion of a polyacrylate dispersant in the aqueous paint composition according to the present disclosure improves the dispersibility of phthalocyanine blue and phthalocyanine green, resulting in an aqueous paint composition with less color variation and less roughness in the coating film.

[0041] (water) The aqueous paint composition according to the present disclosure contains water as a medium for dissolving or dispersing the above-mentioned components. The proportion of water in the aqueous paint composition is appropriately determined taking into consideration the required properties, such as ease of drying of the paint. For example, the water content of the aqueous paint composition may be 10% by mass or more and 70% by mass or less, and more preferably 20% by mass or more and 55% by mass or less, based on the total mass of the aqueous paint composition. The aqueous paint composition may also contain an aqueous medium other than water. Examples of aqueous medium other than water include hydroxyl-containing water-soluble media such as alcohols, diols, and glycerin.

[0042] (Other ingredients) The aqueous paint composition according to the present disclosure may further contain other components such as colorants other than pigments, such as dyes, etc. Furthermore, the aqueous paint composition according to the present disclosure may contain other known additive components such as wetting agents, preservatives, antifungal agents, defoamers, and anti-foaming agents, as needed.

[0043] Examples of preservatives and antifungal agents that can be used include benzoisothiazoline-based preservatives and antifungal agents, pentachlorophenol-based preservatives and antifungal agents, cresol-based preservatives and antifungal agents, propylene glycol-based preservatives and antifungal agents, bromine-based preservatives and antifungal agents, and iodine-based preservatives and antifungal agents, and can be used alone or in combination of two or more. The amount of preservative and antifungal agent added is not particularly limited, but can be, for example, from 0.01% to 5% by mass of the aqueous paint composition, and preferably from 0.1% to 2% by mass.

[0044] (Uses of water-based paint compositions) The aqueous paint composition according to the present disclosure is typically used as an aqueous paint contained in a tube made of polyethylene resin, laminated aluminum, etc. The aqueous paint composition according to the present disclosure is suitably used to constitute a green or blue-based paint, such as those called "green," "yellow-green," "blue-green," "blue," "light blue," etc., among aqueous paints.

[0045] (Manufacturing method) The method for producing the aqueous paint composition according to the present disclosure is not particularly limited, and known methods can be used. For example, the aqueous paint composition can be obtained by mixing and dispersing the components using known mixers such as a turbo mixer, kneader, Henschel mixer, three-roll mill, horizontal ball mill, horizontal bead mill, etc.

[0046] [Example] The aqueous paint composition according to the present disclosure will be explained in more detail with reference to examples, but the scope of the aqueous paint composition according to the present disclosure should not be construed as being limited by the description of these examples.

[0047] (Preparation of Water-Based Paint Composition) Water-based paint compositions were prepared in Examples 1 to 4 and Comparative Examples 1 and 2. In Examples 1, 2, and 4 and Comparative Examples 1 and 2, the paint (acrylic gouache) is water-insoluble on the coated surface after drying. In Example 3, the paint (opaque watercolor paint) is water-soluble on the coated surface after drying. The preparation procedure involved preparing each material according to the formulations shown in Tables 1 to 3, and dispersing all materials except the antifoaming agent and resin emulsion using a hydraulic triple roll mill. The antifoaming agent and resin emulsion were then added, followed by stirring and degassing to obtain an aqueous paint composition (Example 3 did not contain a resin emulsion, so no resin emulsion was added). The blending ratios of each material shown in Tables 1 to 3 represent the number of parts by mass of each material blended per 100 parts by mass of the total weight of the aqueous paint composition. For each example, the aqueous paint composition was prepared under the following three dispersion conditions. Dispersion condition 1 (standard condition): The gap between the rolls at this time was used as the reference value. Dispersion condition 2: The gap between the rolls was set to 2.5 times the standard value. Dispersion condition 3: The gap between the rolls was set to 0.2 times the reference value.

[0048] (Evaluation of Water-Based Paint Compositions) [Hue H evaluation] Each of the aqueous paint compositions obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was diluted with 20% water and applied to paper (PHO Kent paper), after which the color was measured with a spectrophotometer to determine the hue H value.

[0049] [ΔE evaluation] For each of Examples 1 to 4 and Comparative Examples 1 and 2, ΔE was calculated from the L*a*b values ​​of the aqueous paint composition obtained under dispersion condition 2 and the aqueous paint composition obtained under dispersion condition 3. It is considered that the smaller the ΔE, the less color difference there is in the product due to differences in dispersion conditions, and evaluation was performed according to the following criteria. ◯: ΔE is less than 2; no visual difference. △: ΔE is 2 or more and less than 3; a difference is visually observed, but is a slight difference. ×: ΔE is 3 or more; there is a clear difference.

[0050] [Particle size measurement] The particle diameter (D 50 and D 90 ) was measured. D 50 It was judged that larger values ​​tend to result in poor color development. D 90 It was judged that the larger the value, the more likely the coating surface was to become rough.

[0051] The formulations and evaluation results of the aqueous paint compositions of Examples 1 and 2 are shown in Table 1, the formulations and evaluation results of the aqueous paint compositions of Examples 3 and 4 are shown in Table 2, and the formulations and evaluation results of the aqueous paint compositions of Comparative Examples 1 and 2 are shown in Table 3. A blank space in each table indicates that the material was not included.

[0052] [Table 1]

[0053] [Table 2]

[0054] [Table 3]

[0055] The specific materials used in Examples 1 to 4 and Comparative Examples 1 and 2 were as follows. Wetting agent: Propylene glycol (AGC) Water-soluble resin: Hydroxyethyl cellulose (Tylose H series P type, manufactured by Shin-Etsu Chemical Co., Ltd.) Polyacrylate dispersant 1: Polyacrylate (DISPERBYK181, manufactured by BYK Co., Ltd., active ingredient 65%) Polyacrylate dispersant 2: Polyacrylate (Solperse 43000, Lubrisol, active ingredient 50%) Dispersant: Polyoxyethylene styrenated phenol (Emulgen A-60, manufactured by Kao Corporation) Dispersant: Phosphate ester (Plysurf A-212C, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Dispersant: Phosphate ester (Plysurf A-212E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Preservative: Mixture of bromine compounds (San-ai Back SA, manufactured by San-ai Oil Co., Ltd.) Antifoaming agent: mineral oil, hydrophobic silica (Nopco 8034-L, manufactured by San Nopco Co., Ltd.) Extender pigment: calcium carbonate (light calcium carbonate, manufactured by Shanghai Yueda Co., Ltd.) Extender pigment: sodium aluminosilicate (SIPERNAT 820A, manufactured by Evonik Japan Co., Ltd.) Extender pigment: Bentonite (Hakuba Bentonite, manufactured by Hojun Co., Ltd.) Pigment: Titanium oxide (Titanium oxide JR-701, manufactured by Teika Co., Ltd.) Pigment: PY3 (Seika First Yellow 2030, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) Pigment: PG7 (Cyanine Green 2GO, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) Pigment: PB15:3 (Cyanine Blue 4927, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) Resin emulsion: Vinyl acetate / acrylic ester copolymer aqueous emulsion (Movinyl DM-5, manufactured by Japan Coating Resin Co., Ltd.)

[0056] As shown in Tables 1 to 3, the aqueous paint compositions of Examples 1 to 4 had hues ranging from 5.3G to 6.3G and developed a green color. ΔE was 0.58 to 2.31, and the color did not change significantly even when the dispersion conditions were changed, resulting in stable color development. A blend of 5% by mass (3.3% by mass of active ingredient) of polyacrylate dispersant for cyanine blue and cyanine green was effective (Example 4), and when the blending amount was 15% by mass (7.5 to 9.8% by mass of active ingredient) (Examples 1 to 3), the color difference due to differences in dispersion conditions was even smaller.

[0057] In contrast, Comparative Example 1, which did not contain a polyacrylate-based dispersant, had a slightly yellowish hue. 50 , D 90 The value was larger than in Examples 1 to 4, and it was thought that the poor dispersibility was the reason for the poor color development and roughness of the coating film. Furthermore, ΔE was 5.15, and there was a large variation in color depending on the dispersion conditions. In addition, in Comparative Example 2, in which the blending amount of polyacrylate-based dispersant relative to cyanine green and cyanine blue was 1% by mass (0.7% by mass of active ingredient), the hue was slightly yellowish under Dispersion Conditions 1 and 2. 50 , D 90 The value was larger than those of Examples 1 to 4, and it was thought that the poor dispersibility was the reason for the poor color development and roughness of the coating film. Furthermore, in Comparative Example 2, ΔE was 4.39, and there was a large variation in color depending on the dispersion conditions.

[0058] It has been confirmed that the aqueous paint composition according to the present disclosure can be produced stably regardless of the dispersion conditions by using a polyacrylate dispersant in combination with cyanine green and cyanine blue, and that it is possible to obtain an aqueous paint composition that is a green paint with excellent color development and little roughness in the coating film.

[0059] It should be understood that the embodiments and examples disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims.

Claims

1. at least one of phthalocyanine blue and phthalocyanine green; a dispersant; and A water-soluble resin, and water, an aqueous paint composition comprising: the dispersant contains a polyacrylate-based dispersant in an amount of 3 mass% or more relative to the total mass of phthalocyanine blue and phthalocyanine green; Water-based paint compositions.

2. the proportion of the polyacrylate dispersant relative to the total mass of phthalocyanine blue and phthalocyanine green is 3% by mass or more and 35% by mass or less; The aqueous paint composition according to claim 1.

3. The dispersant further includes a dispersant other than a polyacrylate-based dispersant. The aqueous paint composition of claim 1.

4. the ratio of the total mass of phthalocyanine blue and phthalocyanine green to the total mass of the aqueous paint composition is 0.1% by mass or more and 20% by mass or less; The aqueous paint composition according to any one of claims 1 to 3.

5. A green paint comprising the aqueous paint composition according to any one of claims 1 to 3.

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