Water-based covering materials

Abstract

To improve performances, such as storage stability and cissing resistance, in a water-based coating material including a pigment.SOLUTION: A water-based coating material of the present invention includes 10-200 pts.wt. of a pigment with respect to 100 pts.wt. of a solid content of a synthetic resin emulsion, and a heating residue is 5-31.8 wt.%. When viscosity at 4 rpm measured with a BH-type viscometer (a guideline value of a second rotation, measurement temperature 23°C) is μ4, and viscosity at 100 rpm (a guideline value of a fourth rotation, measurement temperature 23°C) is μ100, μ4 is 1-50 Pa s, and a value of μ4 / μ100 is 10 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a novel aqueous coating material. [Background technology]

[0002] Traditionally, various coatings have been applied to buildings and civil engineering structures for the purpose of beautifying and protecting the surface. In these painted finishes, coatings generally called sealers or primers are used for purposes such as homogenizing the painted surface, preventing the leaching of alkaline components, preventing the penetration of moisture and carbon dioxide into the painted surface (preventing neutralization), and improving the adhesion between the painted surface and the finishing coating. While solvent-based and water-based materials are known for such coatings, in recent years there has been a shift towards water-based materials from the perspective of environmental hygiene and work safety.

[0003] Such water-based coatings are generally designed to achieve the above effects with a thin film of approximately several tens of microns. Therefore, their viscosity is set lower compared to finishing coatings that exhibit various patterns and colors. However, with such low-viscosity water-based coatings, there is a risk of repelling when applied to the surface to be coated.

[0004] Patent Document 1 describes an aqueous emulsion composition that can suppress the occurrence of repulsion and other issues. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2003-261732 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the above-mentioned patent document does not consider the performance when pigments are included. In aqueous coating materials such as sealers and primers, pigments may be mixed in from the viewpoint of improving the color development, opacity, and strength of the coating film, but if pigments are mixed into the composition of the above-mentioned patent document, sedimentation and aggregation of the pigment during storage may be unavoidable.

[0007] This invention has been made in view of the above-mentioned problems, and aims to improve the performance of aqueous coating materials containing pigments, such as storage stability and resistance to repelling. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above objective, the inventors conceived of an aqueous coating material that satisfies specific heating residue, viscosity conditions, etc., and thus completed the present invention.

[0009] In other words, the present invention has the following features. 1. An aqueous coating material containing a synthetic resin emulsion and a pigment, The above aqueous coating material contains a pigment in proportion to 100 parts by weight of the solid content of the above synthetic resin emulsion. 30~120 Including weight portion, Heating residue 15~31.8 It is a percentage by weight, The viscosity at 4 rpm (indicator value at the second rotation, measured at 23°C) measured with a BH-type viscometer is μ4, and the viscosity at 100 rpm (indicator value at the fourth rotation, measured at 23°C) is μ 100 In that case, μ4 7.8~12.2 Pa·s μ4 / μ 100 The value 11.3~13.0 A water-based coating material characterized by the following: 2. The aqueous coating material according to 1, further comprising a viscosity modifier, characterized in that the viscosity modifier comprises two or more selected from associative viscosity modifiers, alkali swelling type viscosity modifiers, water-soluble polymer type viscosity modifiers, and inorganic viscosity modifiers. 3. The aqueous coating material according to 2., wherein the viscosity modifier is any one combination of: an associative viscosity modifier and an alkali-swelling viscosity modifier; an associative viscosity modifier and a water-soluble polymer viscosity modifier; an associative viscosity modifier and an inorganic viscosity modifier; and an associative viscosity modifier and another associative viscosity modifier. [Effects of the Invention]

[0010] The aqueous coating material of the present invention can exhibit excellent performance in storage stability, cissing resistance and other properties. [Mode for Carrying Out the Invention]

[0011] Modes for carrying out the present invention are described below.

[0012] [Aqueous Coating Material] The aqueous coating material of the present invention contains a synthetic resin emulsion and a pigment as essential components.

[0013] The synthetic resin emulsion (hereinafter also referred to as "component (A)") acts as a binder. Examples of the synthetic resin for component (A) include acrylic resins, urethane resins, vinyl acetate resins, alkyd resins, silicone resins, epoxy resins, chlorine-based resins, acrylic silicone resins, fluororesins, and composite resins of any of the foregoing. These may be used singly or in combination of two or more.

[0014] As component (A), an acrylic resin emulsion may be included from the viewpoints of adhesion, sealing properties, durability and the like. Examples of the acrylic resin emulsion include carboxyl group-containing acrylic resin emulsions, epoxy group-containing acrylic resin emulsions, hydroxyl group-containing acrylic resin emulsions, alkoxysilyl group-containing acrylic resin emulsions, carbonyl group-containing acrylic resin emulsions, nitrile group-containing acrylic resin emulsions, amino group-containing acrylic resin emulsions, and amide group-containing acrylic resin emulsions. These may be used singly or in combination of two or more.

[0015] As the acrylic resin emulsion, for example, those obtained by emulsion polymerization of alkyl (meth)acrylate and a monomer copolymerizable with the alkyl (meth)acrylate can be used. In the present invention, alkyl acrylate and alkyl methacrylate are collectively referred to as alkyl (meth)acrylate. In addition, the term "monomer" is a general term for compounds having a polymerizable unsaturated double bond.

[0016] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, and the like. These may be used alone or in combination of two or more thereof.

[0017] Examples of the monomer copolymerizable with alkyl (meth)acrylate include: carboxyl group-containing monomers such as (meth)acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, isocrotonic acid, and salicylic acid; epoxy group-containing monomers such as glycidyl (meth)acrylate, diglycidyl fumarate, 3,4-epoxycyclohexyl (meth)acrylate, 3,4-epoxyvinylcyclohexane, allyl glycidyl ether, ε-caprolactone-modified glycidyl (meth)acrylate, and β-methylglycidyl (meth)acrylate; hydroxyl group-containing monomers such as hydroxypropyl (meth)acrylate, ethylene glycol mono(meth)acrylate, and glycerol mono(meth)acrylate;

[0018] 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysisiliane, vinyltriethoxysisiliane, vinyltriisopropoxysilane, and other monomers containing alkoxysilyl groups; Carbonyl group-containing monomers such as acrolein, diacetone (meth)acrylamide, vinyl methyl ketone, vinyl ethyl ketone, and vinyl butyl ketone; Nitrile group-containing monomers such as (meth)acrylonitrile, vinylidene cyanide, and α-cyanoethyl (meth)acrylate;

[0019] Amino group-containing monomers such as aminomethyl acrylate, aminoethyl acrylate, aminopropyl (meth)acrylate, amino-n-butyl (meth)acrylate, butylvinylbenzylamine, vinylphenylamine, p-aminostyrene, N-methylaminoethyl (meth)acrylate, and Nt-butylaminoethyl (meth)acrylate; Amide group-containing monomers such as maleic acid amide, (meth)acrylamide, N-monoalkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, 2-(dimethylamino)ethyl (methacrylate), N-[3-(dimethylamino)propyl](meth)acrylamide, and vinylamide;

[0020] Aromatic monomers such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, phenyl(meth)acrylate, and benzyl(meth)acrylate; Examples include vinylidene halogenated monomers such as vinylidene fluoride; ethylene, propylene, isoprene, butadiene, vinyl ether, vinyl ketone, and silicone macromers. These can be used individually or in combination of two or more.

[0021] In the present invention, by including at least an epoxy group-containing acrylic resin emulsion as component (A), performance such as adhesion can be sufficiently enhanced. As the epoxy group-containing acrylic resin, for example, one can be used that is obtained by emulsion polymerization of an alkyl (meth)acrylate, an epoxy group-containing monomer, and, if necessary, other monomers copolymerizable with these. From the viewpoint of improving adhesion, the composition ratio of the epoxy group-containing monomer in the epoxy group-containing acrylic resin emulsion is preferably 0.5 to 50% by weight (more preferably 1 to 30% by weight) of the total monomer constituting component (A).

[0022] Component (A) can be produced, for example, by emulsion polymerization of a group of monomers obtained by appropriately mixing the above monomers. Any known polymerization method may be used, and in addition to ordinary emulsion polymerization, soap-free emulsion polymerization, feed emulsion polymerization, seed emulsion polymerization, etc., can also be used. It can also be produced by a one-stage or multi-stage (two-stage or three or more-stage) emulsion polymerization method. During polymerization, for example, emulsifiers, initiators, dispersants, polymerization inhibitors, polymerization inhibitors, buffers, chain transfer agents, pH adjusters, etc., can be used.

[0023] Various surfactants suitable for emulsion polymerization can be used as emulsifiers, and these may be reactive types (reactive surfactants) having polymerizable unsaturated double bonds. For example, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., can be used individually or in combination as emulsifiers.

[0024] The glass transition temperature of component (A) can be adjusted by selecting the type of monomer, mixing ratio, etc. This glass transition temperature should be set appropriately considering the final required performance, but is preferably around -50 to 80°C (more preferably around -40 to 60°C). The glass transition temperature can be calculated using Fox's formula.

[0025] The average particle size of component (A) is not particularly limited, but is preferably 300 nm or less (more preferably 20 to 250 nm, and even more preferably 30 to 200 nm). If the average particle size is within this range, it is preferable in terms of improving performance such as impregnation reinforcement, sealing properties, efflorescence resistance, and whitening resistance. The average particle size referred to herein is a value measured by dynamic light scattering.

[0026] Pigments such as coloring pigments and extender pigments can be used. Of these, coloring pigments are components that contribute to improving the color development, opacity, and strength of the coating.

[0027] Examples of coloring pigments include inorganic coloring pigments such as titanium dioxide, zinc oxide, alumina, carbon black, ferric oxide (red iron oxide), yellow iron oxide, titanium yellow, black iron oxide, ultramarine, cobalt blue, cobalt green, magnesium oxide, zirconium oxide, yttrium oxide, indium oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, copper-magnesium composite oxide, and bismuth-manganese composite oxide; Organic coloring pigments such as azo, naphthol, pyrazolone, anthraquinone, perylene, quinacridone, disazo, isoindolone, benzimidazole, phthalocyanine, and quinophthalone; These can be used. By using one or more of these coloring pigments as appropriate, the coating can be set to a desired color tone.

[0028] In the present invention, even when inorganic coloring pigments are included as pigments, particularly when inorganic coloring pigments with a specific gravity of 2 or more (and even 3 or more) are included, advantageous effects such as storage stability can be achieved.

[0029] Extender pigments are components that contribute to improving the strength of the coating, adjusting gloss, and adjusting the solid content. Examples of extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, pottery clay, china clay, diatomaceous earth, hydrated fine silica, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, resin powder, resin beads, and aluminum hydroxide. One or more of these can be used.

[0030] The ratio of pigment is 10 to 200 parts by weight, preferably 20 to 150 parts by weight, and more preferably 30 to 120 parts by weight, per 100 parts by weight of solids of component (A). When a coloring pigment is included as the pigment, the ratio of coloring pigment is preferably 10 to 150 parts by weight, more preferably 20 to 120 parts by weight, and even more preferably 30 to 100 parts by weight, per 100 parts by weight of solids of component (A). When the composition ratio of coloring pigment is above the lower limit above, it is preferable in terms of improved color development, opacity, and strength. When the ratio of coloring pigment is below the upper limit above, it is preferable in terms of thinning of the coating, flattening, sealing properties, and crack suppression.

[0031] The aqueous coating material of the present invention may contain, in addition to the above-mentioned components, various additives that can be mixed with conventional coating materials. Examples of such additives include viscosity modifiers, film-forming aids, curing agents, plasticizers, preservatives, antifungal agents, antialgal agents, antibacterial agents, defoaming agents, leveling agents, coupling agents, surfactants, pigment dispersants, anti-settling agents, anti-sagging agents, wetting agents, catalysts, curing accelerators, dehydrating agents, defoaming agents, matting agents, antifreeze agents, ultraviolet absorbers, antioxidants, light stabilizers, water, solvents, and the like. The aqueous coating material of the present invention can be manufactured by uniformly mixing a synthetic resin emulsion, a pigment, and various additives as needed using conventional methods.

[0032] The aqueous coating material of the present invention has a heating residue of 5 to 60% by weight, preferably 10 to 50% by weight, and more preferably 15 to 45% by weight. Having the heating residue within this range is advantageous in terms of thin film formation, flattening, and sealing properties. If the heating residue falls below the lower limit, the sealing properties become insufficient, making it difficult to obtain sufficient effects in homogenizing the coated surface, preventing the leaching of alkaline components, preventing the penetration of moisture and carbon dioxide into the coated surface, and improving adhesion. If the heating residue exceeds the upper limit, the coating becomes thicker, and irregularities are more likely to occur. Note that the heating residue is the value measured according to the method of JIS K5601-1-2 "Heating Residue," under conditions of a heating temperature of 135°C and a heating time of 60 minutes.

[0033] In this invention, the viscosity at 4 rpm measured with a BH-type viscometer (indicator value at the second rotation, measurement temperature 23°C) is μ4, and the viscosity at 100 rpm (indicator value at the fourth rotation, measurement temperature 23°C) is μ 100 In this case, μ4 is 1 to 50 Pa·s, and μ4 / μ 100 The present invention is characterized by having a viscosity value of 10 or more. By satisfying these viscosity conditions, the aqueous coating material of the present invention can exhibit excellent performance in terms of storage stability, repellency, etc., and is also advantageous in thin-film formation.

[0034] μ4 is 1 to 50 Pa·s, preferably 3 to 40 Pa·s, more preferably 6 to 30 Pa·s, and even more preferably 8 to 20 Pa·s. If μ4 falls below the lower limit, pigment sedimentation, aggregation, etc., are likely to occur during storage. If μ4 exceeds the upper limit, the coating becomes thicker and unevenness is likely to occur.

[0035] μ4 / μ 100 The value is 10 or greater, preferably 10-20, more preferably 10.5-18, and even more preferably 11-16. μ4 / μ 100 If the value falls below the lower limit mentioned above, the coating is more likely to repel paint after application. Also, μ4 / μ 100 By setting the upper limit of the value to the above value, it is possible to suppress the occurrence of irregularities in the coating and obtain sufficient effects in terms of thinning and flattening.

[0036] In the present invention, μ4 and μ4 / μ 100 The mechanism by which the effects of the present invention are achieved when the value of satisfies the above conditions is not limited to the following, but when coating is performed on the surface to be coated (under a high shear rate), even if there are signs of repulsion on the surface to be coated, the viscosity is quickly and sufficiently restored in the subsequent standing state (under a low shear rate), so it is thought that the occurrence of repulsion is suppressed.

[0037] In this invention, by setting the ratio of synthetic resin emulsion to pigment and the heat residue within the above range, and further mixing in a viscosity modifier, an aqueous coating material that satisfies the above viscosity conditions can be obtained. The type and ratio of the viscosity modifier can be appropriately set to satisfy the above viscosity conditions.

[0038] Examples of viscosity modifiers include associative viscosity modifiers, alkali swelling viscosity modifiers, water-soluble polymer viscosity modifiers, and inorganic viscosity modifiers. These can be used individually or in combination of two or more.

[0039] Specifically, examples of associative viscosity modifiers include hydrophobic modified ethoxylated urethane (HEUR), hydrophobic modified alkali-swellable / soluble emulsion (HASE), hydrophobic modified hydroxyethylcellulose (HMHEC), and hydrophobic polyacrylamide. Examples of alkali-swellable viscosity modifiers (ASE) include alkali-swellable acrylic emulsion. Examples of water-soluble polymer-type viscosity modifiers include cellulose, cellulose derivatives (carboxymethylcellulose, carboxyethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, oxidized cellulose, etc.), polyvinyl alcohol, alginic acid, sodium alginate, polyvinylpyrrolidone, biogum, starch, starch derivatives (carboxyalkyl starch, alkyl starch, hydroxyalkyl starch, oxidized starch, etc.), xanthan gum, guar gum, locust bean gum, carrageenan, gum arabic, tragacando gum, gelatin, agar, casein, psyllium sheet gum, tamarind sheet gum, etc. Examples of inorganic viscosity modifiers include bentonite, smectite, silica, montmorillonite, etc. These can be used individually or in combination of two or more. In the present invention, it is desirable that the viscosity modifier includes at least an associative viscosity modifier, and more preferably at least a hydrophobic modified ethoxylated urethane (HEUR).

[0040] The present invention may include two or more viscosity modifiers. Such embodiments are more preferable in terms of adjusting the viscosity of aqueous coating materials. Examples of such viscosity modifier combinations include an associative viscosity modifier and an alkali-swelling viscosity modifier, an associative viscosity modifier and a water-soluble polymer viscosity modifier, an associative viscosity modifier and an inorganic viscosity modifier, and so on. Furthermore, two or more associative viscosity modifiers can also be combined, and examples of such combinations include hydrophobic modified ethoxylated urethane (HEUR) and hydrophobic modified alkali-swelling / soluble emulsion (HASE), hydrophobic modified ethoxylated urethane (HEUR) and hydrophobic modified hydroxyethylcellulose (HMHEC), hydrophobic modified ethoxylated urethane (HEUR) and hydrophobic polyacrylamide, and hydrophobic modified ethoxylated urethane (HEUR) with other hydrophobic modified ethoxylated urethane (HEUR).

[0041] The ratio of the viscosity modifier is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 4 parts by weight, and even more preferably 0.5 to 3 parts by weight, based on solid content, per 100 parts by weight of solid content of component (A). A ratio of the viscosity modifier within this range is more favorable in terms of adjusting the viscosity of the aqueous coating material.

[0042] [Film formation method] The aqueous coating material of the present invention can be applied to a surface to be coated to form a film. The aqueous coating material of the present invention is suitable as a sealer or primer.

[0043] Examples of surfaces to be coated include the interior and exterior walls of buildings and civil engineering structures. Examples of substrates constituting the surfaces to be coated include concrete, mortar, porcelain tiles, fiber-reinforced cement boards, cement calcium silicate boards, slag cement perlite boards, cement boards, ALC boards, siding boards, gypsum boards, plywood, extruded boards, steel plates, and plastic boards. The surfaces of these substrates may have undergone some kind of surface treatment (for example, treatment with putty, sealer, surfacer, filler, etc.), or they may already have a coating film applied to them, or have wallpaper or the like attached to them.

[0044] When the surface to be coated is composed of a plurality of plate-shaped base materials, the joints between adjacent plate-shaped base materials may be filled with a joint material such as a sealing material or a dry joint material. The surface of such a joint material or the vicinity thereof may be surface-treated with an elastic joint treatment material or the like.

[0045] For coating with the aqueous coating material, known coating tools can be used. As the coating tool, for example, spray, roller, brush and the like can be used. The coating amount of the aqueous coating material may be appropriately set according to the type and surface shape of the surface to be coated, the coating tool to be used, etc., and is preferably 0.03 to 0.5 kg / m 2 , more preferably 0.05 to 0.3 kg / m 2 . During coating, the aqueous coating material can be appropriately diluted, and it is desirable that the diluted aqueous coating material also satisfies the above viscosity condition.

[0046] Coating of the aqueous coating material can be performed at normal temperature (0 to 40°C). Drying after coating the aqueous coating material can also be performed at normal temperature, and heating is also possible if necessary. In the case of normal temperature drying, the drying time is preferably 1 hour or more, more preferably about 2 to 200 hours.

[0047] In the present invention, a finishing coating material can be applied after the above-mentioned aqueous coating material is coated and dried. One or more types of coating materials can be used as the finishing coating material. Specifically, for example, architectural finishing coating materials specified in JIS A6909, including thin finishing coating materials such as ricin paints and single-layer elastic coating materials, thick finishing coating materials such as stucco paints, multi-layer finishing coating materials, etc., architectural waterproof coating films specified in JIS A6021, as well as multi-color pattern paints, stone-texture finishing coating materials, sandstone-texture finishing coating materials, synthetic resin emulsion paints, glossy synthetic resin emulsion paints, non-aqueous dispersed resin enamels, and the like can be mentioned.

[0048] Various resins can be used as the resin component in the finishing coating material. Examples of resin types include vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc., or composite resins thereof. Among these, one or more types selected from acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc. are preferred. Furthermore, examples of such resin components include water-soluble resins, water-dispersible resins (resin emulsions), solvent-soluble resins, solvent-free resins, non-aqueous-dispersible resins, powder resins, etc. Among these, one or more types selected from water-soluble resins, water-dispersible resins, solvent-soluble resins, and non-aqueous-dispersible resins are preferred. In addition, these resin components may have crosslinking reactivity. When a resin component with crosslinking reactivity is used, the durability, water resistance, weather resistance, chemical resistance, adhesion, etc. of the coating can be improved.

[0049] The form of the finishing coating material can be, for example, one-component, two-component, or multi-component. The degree of gloss of the finishing coating material can be, for example, high gloss, 70% gloss, 50% gloss, 30% gloss, or matte.

[0050] For applying the finishing coating, known application tools can be used. Examples of application tools include sprayers, rollers, brushes, and trowels. The amount of finishing coating applied should be appropriately determined according to the type and shape of the surface to be coated, the type of finishing coating, and the type of application tool, but preferably 0.05 to 5 kg / m². 2 More preferably 0.1 to 4 kg / m 2 During painting, the finishing coating material can be diluted as needed. [Examples]

[0051] The following examples illustrate the features of the present invention.

[0052] (Example 1) A aqueous coating material 1 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 {epoxy group-containing acrylic resin emulsion (styrene / 2-ethylhexyl acrylate / glycidyl methacrylate copolymer, glass transition temperature 18°C, solids content 40% by weight, average particle size 90 nm)}, 60 parts by weight of coloring pigment 1 {titanium dioxide (average particle size 0.3 μm, specific gravity 4.2)}, 1 part by weight of anionic surfactant, 0.5 parts by weight of nonionic surfactant, 10 parts by weight of film-forming aid (ether-based solvent), 0.5 parts by weight of defoaming agent (silicone-based defoaming agent), 180 parts by weight of water, 4 parts by weight of viscosity modifier 1 {associative viscosity modifier (hydrophobic modified polyoxyethylene urethane resin, solids content 30% by weight)}, and 7 parts by weight of viscosity modifier 3 {water-soluble polymer-type viscosity modifier (hydroxyethylcellulose aqueous solution, solids content 3% by weight)} by a conventional method. The heat residue of aqueous coating material 1 was 31.8% by weight, and the μ4 was 12.2 Pa·s, and μ4 / μ 100 The value was 13.0.

[0053] (Example 2) Aqueous coating material 2 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 (same as above), 60 parts by weight of coloring pigment 1 (same as above), 1 part by weight of anionic surfactant (same as above), 0.5 parts by weight of nonionic surfactant (same as above), 10 parts by weight of film-forming aid (same as above), 0.5 parts by weight of defoaming agent (same as above), 180 parts by weight of water, 4 parts by weight of viscosity modifier 1 (same as above), and 7 parts by weight of viscosity modifier 4 {water-soluble polymer type viscosity modifier (methylcellulose aqueous solution, solid content 3 by weight)} by a conventional method. The heat residue of aqueous coating material 2 was 31.8% by weight, and μ4 was 11.5 Pa·s, and μ4 / μ 100 The value was 12.6.

[0054] (Example 3) Aqueous coating material 3 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 (same as above), 60 parts by weight of coloring pigment 1 (same as above), 1 part by weight of anionic surfactant (same as above), 0.5 parts by weight of nonionic surfactant (same as above), 10 parts by weight of film-forming aid (same as above), 0.5 parts by weight of defoaming agent (same as above), 180 parts by weight of water, 4 parts by weight of viscosity modifier 1 (same as above), and 7 parts by weight of viscosity modifier 5 {water-soluble polymer type viscosity modifier (aqueous solution of starch derivative, solid content 3 by weight)} by a conventional method. The heat residue of aqueous coating material 3 was 31.8% by weight, and μ4 was 12.0 Pa·s, and μ4 / μ 100 The value was 12.4.

[0055] (Example 4) Aqueous coating material 4 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 (same as above), 60 parts by weight of coloring pigment 1 (same as above), 1 part by weight of anionic surfactant (same as above), 0.5 parts by weight of nonionic surfactant (same as above), 10 parts by weight of film-forming aid (same as above), 0.5 parts by weight of defoaming agent (same as above), 160 parts by weight of water, 24 parts by weight of viscosity modifier 2 {associative viscosity modifier (hydrophobically modified hydroxyethylcellulose solution, solid content 3% by weight)}, and 7 parts by weight of viscosity modifier 3 (same as above) by a conventional method. The heat residue of aqueous coating material 4 was 31.7% by weight, and μ4 was 7.8 Pa·s, and μ4 / μ 100 The value was 11.3.

[0056] (Comparative Example 1) Aqueous coating material 5 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 (same as above), 60 parts by weight of coloring pigment 1 (same as above), 1 part by weight of anionic surfactant (same as above), 0.5 parts by weight of nonionic surfactant (same as above), 10 parts by weight of film-forming aid (same as above), 0.5 parts by weight of defoaming agent (same as above), 145 parts by weight of water, and 46 parts by weight of viscosity modifier 2 (same as above) by a conventional method. The heat residue of aqueous coating material 5 was 31.8% by weight, and μ4 was 11.8 Pa·s, and μ4 / μ 100 The value was 8.6.

[0057] (Comparative Example 2) A aqueous coating material 6 was obtained by uniformly mixing 250 parts by weight of synthetic resin emulsion 1 (same as above), 60 parts by weight of coloring pigment 1 (same as above), 1 part by weight of anionic surfactant (same as above), 0.5 parts by weight of nonionic surfactant (same as above), 10 parts by weight of film-forming aid (same as above), 0.5 parts by weight of defoaming agent (same as above), 180 parts by weight of water, and 5 parts by weight of viscosity modifier 1 (same as above) by a conventional method. The heat residue of the aqueous coating material 6 was 32.2% by weight, and the μ4 was 5.6 Pa·s, and the μ4 / μ 100 The value was 9.2.

[0058] ○ Exam 1 Each aqueous coating material obtained by the above method was sealed in a container and stored at 50°C for 30 days, after which the condition inside the container was evaluated. The evaluation criteria are as follows. A: No abnormalities B: Slight sedimentation and separation are observed. C: Clear sedimentation and separation are observed.

[0059] ○ Exam 2 For slate boards that already have a brown coating applied, a fibrous roller is used to apply the coating at a rate of 0.1 kg / m². 2 Each water-based coating material was applied, and the degree of paint repellency was evaluated. The evaluation criteria are as follows: A: No repulsion B: A slight deflection is observed. C: Clearly, a rejection is observed.

[0060] ○ Test results The test results are shown in Table 1. All tests in Examples 1-4 yielded favorable results.

[0061] [Table 1]

Claims

1. A water-based coating material containing a synthetic resin emulsion and a pigment, The above aqueous coating material contains 30 to 120 parts by weight of pigment per 100 parts by weight of solids of the above synthetic resin emulsion. The residual heat content is 15-31.8% by weight. The viscosity at 4 rpm measured with a BH-type viscometer (indicator value on the second rotation, measurement temperature 23°C) is expressed in μm. ４ The viscosity at 100 rpm (indicator value at the 4th rotation, measured at a temperature of 23°C) is measured in μm. １００ In that case, μ ４ The range is 7.8 to 12.2 Pa·s. μ ４ / μ １００ A water-based coating material characterized in that the value of is 11.3 to 13.

0.

2. The aqueous coating material according to claim 1, further comprising a viscosity modifier, and characterized in that the viscosity modifier comprises two or more selected from associative viscosity modifiers, alkali swelling type viscosity modifiers, water-soluble polymer type viscosity modifiers, and inorganic viscosity modifiers.

3. The aqueous coating material according to claim 2, characterized in that the viscosity modifier is a combination of an associative viscosity modifier and an alkali swelling type viscosity modifier, an associative viscosity modifier and a water-soluble polymer type viscosity modifier, an associative viscosity modifier and an inorganic viscosity modifier, or an associative viscosity modifier and an associative viscosity modifier.

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