Water-based anticorrosive coating composition

Abstract

The present invention addresses the problem of providing a water-based anticorrosive coating composition which can impart satisfactory anticorrosive properties to various metallic materials. This water-based anticorrosive coating composition comprises a water-based main component (I) and a water-based hardener (II), wherein the water-based main component (I) comprises an aqueous epoxy resin dispersion (A) and an inorganic rust-preventive pigment (B) and the water-based hardener (II) includes a polyamine compound (D) containing an aromatic group and a thiazole compound (C).

Description

Technical Field

[0001] The present invention relates to an aqueous anticorrosive coating composition containing an aqueous main agent (I) and an aqueous curing agent (II).

Background Art

[0002] In recent years, along with the intensification of environmental problems, reduction of environmental impact has been desired in the paint field, and various studies have been made. An important issue in the paint field is reduction of the amount of organic solvent used. From such a viewpoint, aqueous paints are used as paints with reduced organic solvents, and their usage amounts are expanding in various fields.

[0003] On the other hand, as one of the uses of paints, there are general industrial uses such as exterior building finishes, bridges, ships, vehicles, industrial machines, construction machines, automobiles, etc. Among these general industrial uses, especially when painting large and thick materials, it is difficult to use baking paints because the heat capacity of the object to be painted is high, and room temperature drying paints are often used.

[0004] As a room temperature drying paint, amine-curing two-component curing epoxy paints are known. Two-component curing epoxy paints have excellent properties in adhesion, water resistance, and anticorrosion, and are used as an undercoat paint (primer) or an anticorrosive paint during painting. In order to make such two-component curing epoxy paints aqueous, the epoxy resin as the base resin is hydrophilized by modifying it with an aliphatic polyol (see, for example, Japanese Patent Laid-Open No. 09-111099 (Patent Document 1)).

[0005] However, when a two-component curing aqueous coating composition is prepared and painted using such a resin, there are technical problems that the curability, pot life, etc. are inferior compared to conventional epoxy-based room temperature drying paint compositions, and the physical properties such as the adhesion and chemical resistance of the obtained coating film are inferior. For example, when the chemical resistance of the coating film decreases, when used for applications such as industrial machines, when in contact with chemical chemicals such as cutting oil, the coating film may be corroded, and the physical properties of the base resin may decrease.

[0006] Incidentally, in recent years, from the perspective of further improving vehicle fuel efficiency, saving energy, and reducing carbon dioxide emissions, there has been a demand for weight reduction in the bodies of automobiles and railways, as well as various vehicle components. One way to lighten these vehicle bodies and components is to replace some or all of the steel material with aluminum material. On the other hand, if, for example, some of the components made of steel material are replaced with aluminum material, it is necessary to provide corrosion protection to both the steel material and the aluminum material that make up the vehicle body and components. However, conventional water-based anticorrosive coating compositions for steel sheets can provide corrosion protection to steel material, but it has been difficult to provide corrosion protection to both steel material and aluminum material. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 09-111099 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to solve the problems of the prior art described above. More specifically, the present invention aims to provide an aqueous anticorrosive coating composition that can impart good corrosion resistance to various metal materials. [Means for solving the problem]

[0009] To solve the aforementioned problems, the present invention provides the following embodiments. [1] A water-based anticorrosive coating composition comprising a water-based main component (I) and a water-based curing agent (II), The aqueous main component (I) comprises an epoxy resin aqueous dispersion (A) and an inorganic rust-preventive pigment (B), and The aqueous curing agent (II) comprises an aromatic group-containing polyamine compound (D) and a thiazole compound (C). A water-based anticorrosive coating composition. [2] The inorganic rust-preventive pigment (B) includes one or more selected from the group consisting of phosphate-based rust-preventive pigments, zinc oxide-based rust-preventive pigments, molybdenum-based rust-preventive pigments, boric acid-based rust-preventive pigments, borosilicate-based rust-preventive pigments, phosphatesilicic acid-based rust-preventive pigments, vanadic acid-based rust-preventive pigments, and tungstic acid-based rust-preventive pigments. [1] A water-based anticorrosive coating composition. [3] The mass ratio [(B):(C)] of the inorganic rust-preventive pigment (B) and the thiazole compound (C) contained in the aqueous anticorrosive paint composition is within the range of (B):(C) = 99.5:0.5 to 60:40. A water-based anticorrosive coating composition of [1] or [2]. [4] The inorganic rust-preventive pigment (B) is an aqueous anticorrosive paint composition from any of [1] to [3], comprising a phosphate-based rust-preventive pigment and a molybdenum-based rust-preventive pigment. [5] The aromatic group-containing polyamine compound (D) is an aqueous anticorrosive coating composition of any of [1] to [4] comprising a hydroxyl group and an aromatic group-containing polyamine compound. [6] The aromatic group-containing polyamine compound (D) is water-soluble and comprises a polyamine compound having a hydroxyl group, a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and an aromatic group, in any of the aqueous anticorrosive coating compositions [1] to [5]. [7] The aforementioned aromatic group-containing polyamine compound (D) is a phenalkamine compound, wherein the aqueous anticorrosive coating composition is any of [1] to [6]. [8] The epoxy equivalent of the epoxy resin aqueous dispersion (A) is in the range of 100 to 10,000 g / eq, wherein the aqueous anticorrosive coating composition is any of [1] to [7]. [9] An aqueous anticorrosive coating composition according to any of [1] to [8], wherein the ratio of the epoxy group content of the epoxy resin aqueous dispersion (A) contained in the aqueous main component (I) to the active hydrogen content of the aromatic group-containing polyamine compound (D) contained in the aqueous curing agent (II) is within the range of [(A) epoxy group content]:[(D) active hydrogen content]=1:0.4 to 1:1.2.

[10] The aqueous anticorrosive coating composition further comprises an aqueous dispersion of polyurethane resin, any of the aqueous anticorrosive coating compositions [1] to [9].

[11] The thiazole compound (C) is an aqueous anticorrosive coating composition from any of [1] to

[10] , comprising a benzothiazole compound.

[12] A water-based anticorrosive coating composition [1] to

[11] for use with aluminum and steel materials. [Effects of the Invention]

[0010] The aforementioned water-based anticorrosive coating composition can impart corrosion protection to metal materials, particularly both steel and aluminum materials. [Modes for carrying out the invention]

[0011] The aforementioned aqueous anticorrosive coating composition comprises an aqueous base (I) and an aqueous curing agent (II). The aqueous base (I) comprises an epoxy resin aqueous dispersion (A) and an inorganic rust-preventive pigment (B), and the aqueous curing agent (II) comprises an aromatic group-containing polyamine compound (D) and a thiazole compound (C). Each component is described below.

[0012] Epoxy resin aqueous dispersion (A) The epoxy resin aqueous dispersion (A) contained in the aqueous main agent (I) is a component in which an epoxy resin is dispersed in water. The epoxy resin is preferably a resin having at least two epoxy groups on average per molecule. The epoxy equivalent of the epoxy resin is preferably in the range of 100 to 10,000 g / eq, and more preferably in the range of 150 to 5,000 g / eq. In the present disclosure, the epoxy equivalent represents the solid content epoxy equivalent and can be measured by a method in accordance with JIS K 7236.

[0013] The number average molecular weight of the epoxy resin may be, for example, in the range of 200 to 20,000, preferably in the range of 300 to 10,000, and more preferably in the range of 500 to 6,000. In the present disclosure, the number average molecular weight is a value in terms of polystyrene by gel permeation chromatography (GPC).

[0014] The epoxy resin may be saturated or unsaturated, may be any of aliphatic, alicyclic, aromatic and / or heterocyclic, and may have a hydroxyl group.

[0015] The epoxy resin is preferably a polyglycidyl ether type epoxy resin having a skeleton based on polyhydric phenols, polyhydric alcohols, hydrogenated products of polyhydric phenols and / or novolak phenols. Among the skeletons, polyhydric alcohols and / or phenols are preferred, and dihydric alcohols are preferred. The aforementioned polyhydric phenols include resorcinol, hydroquinone, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), a mixture of isomers of dihydroxydiphenylmethane (bisphenol F), tetrabromobisphenol A, 4,4'-dihydroxydiphenylcyclohexane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybenzophenone, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis[4-(2'-hydroxypropoxy)phenyl]propane, 1,1-bis(4-hydroxyphenyl)isobutane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, bis(2-hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene, tris(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, etc., as well as halogenation and hydrogenation products of the aforementioned compounds.

[0016] The polyhydric alcohol is not particularly limited, and examples include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (n=4-35), 1,2-propylene glycol, polypropylene glycol (n=2-15), 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, glycerol, neopentyl glycol, trimethylolethane, and trimethylolpropane. Among these compounds, polypropylene glycol (n=8-10) is particularly preferred.

[0017] As the epoxy resin, for example, a polyglycidyl ester obtained by the reaction of a polycarboxylic acid with epichlorohydrin or a derivative thereof can be used. The polycarboxylic acid is not particularly limited, and examples include aliphatic, alicyclic, or aromatic polycarboxylic acids, such as oxalic acid, succinic acid, adipic acid, glutaric acid, phthalic acid, terephthalic acid, hexahydrophthalic acid, 2,6-naphthalenedicarboxylic acid, and dimerized linolenic acid. Among these, diglycidyl adipate, diglycidyl phthalate, and diglycidyl hexahydrophthalate are preferred. Among the epoxy resins, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferred.

[0018] The epoxy resin may be a polyol-modified epoxy resin obtained by reacting an aliphatic polyol compound with the epoxy resin as needed. The polyol-modified epoxy resin can be prepared by condensing the epoxy resin and the aliphatic polyol compound. In the condensation reaction, the mass ratio of the epoxy resin to the aliphatic polyol compound (mass of epoxy resin:mass of aliphatic polyol compound) is preferably in the range of 95:5 to 5:95. The polyol-modified epoxy resin has the advantage of having good water dispersion performance.

[0019] The aliphatic polyol compound is not particularly limited, and examples include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, etc., but polyalkylene glycol, which is a polyether polyol, is preferred. The polyalkylene glycol is preferably a polyalkylene glycol having alkylene groups with 4 or fewer carbon atoms, and examples include polyethylene glycol, polypropylene glycol, polybutylene glycol, and block copolymers of ethylene oxide and propylene oxide. Mixtures or copolymers of the polyalkylene glycol can also be used. Furthermore, it may be partially end-capping with a monohydric alcohol or the like. The polyalkylene glycol may have a partially branched structure, but it is more preferably a linear polyalkylene glycol. The aliphatic polyol compound may be a mixture of the polyalkylene glycol and other aliphatic polyols. Examples of other aliphatic polyols include polyester polyols, polycarbonate polyols, polyamide polyols, and polyurethane polyols, with polyester polyols being particularly preferred. The other aliphatic polyols are preferably 30% or less by mass of the aliphatic polyol compound, and more preferably 10% or less. Other aliphatic polyols include aliphatic polyester polyols of aliphatic dicarboxylic acids and aliphatic diols, dicarboxylic acids having 3 to 40 carbon atoms, diols having 2 to 20 carbon atoms, primary diamines or polyalkylene polyamine compounds having 2 to 40 carbon atoms, or compounds obtained by condensation reactions of compounds selected from amino alcohols, etc.

[0020] The condensation is preferably carried out in a ratio such that the ratio z(OH):z(EP) of the hydroxyl group equivalent of the aliphatic polyol compound to the epoxy equivalent of the epoxy resin is 1:3.6 to 1:10. More preferably, z(OH):z(EP) is in the range of 1:4 to 1:9, and even more preferably, in the range of 1:4.5 to 1:8. Carrying the reaction within this range has the advantage of obtaining good water dispersibility. The epoxy equivalent of the modified epoxy resin (polyol-modified epoxy resin) is preferably in the range of 100 to 10,000 g / eq, more preferably in the range of 150 to 5,000 g / eq, and even more preferably in the range of 200 to 2,000 g / eq.

[0021] The epoxy resin contained in the epoxy resin aqueous dispersion (A) preferably includes polyol-modified bisphenol type epoxy resins such as polyol-modified bisphenol A type epoxy resin and polyol-modified bisphenol F type epoxy resin. These polyol-modified bisphenol type epoxy resins have the advantage of having suitable water dispersibility and producing a coating film with good physical properties. In other embodiments, for example, the polyol-modified epoxy resin (preferably containing a polyol-modified bisphenol type epoxy resin) and a bisphenol type epoxy resin (a bisphenol type epoxy resin without polyol modification) may be used in combination.

[0022] The epoxy resin aqueous dispersion (A) can be prepared by carrying out the synthesis reaction of the epoxy resin (polyol-modified epoxy resin) in the absence of a solvent or in the presence of a suitable organic solvent, then adding it dropwise to water, mixing, and removing any excess solvent as needed to obtain an aqueous dispersion. When dispersing the epoxy resin in water, a dispersant such as a surfactant may be used as needed.

[0023] A commercially available product may be used as the epoxy resin aqueous dispersion (A). Examples of commercially available products include the BECKOPOX series (manufactured by Ornex Japan Co., Ltd.), the jER series (manufactured by Mitsubishi Chemical Corporation), and the ADEKA Resin EM series (manufactured by ADEKA Corporation).

[0024] The epoxy resin aqueous dispersion may be used alone or in combination of two or more types.

[0025] The aqueous main component (I) may, in addition to the epoxy resin aqueous dispersion (A), optionally contain other resin components. Examples of other resin components include polyurethane resin aqueous dispersions, polyester aqueous dispersions, and acrylic resin aqueous dispersions. When further containing other resin components, polyurethane resin aqueous dispersions are preferred as resin components from the viewpoint of compatibility with epoxy resin aqueous dispersion (A). When the aqueous main component (I) further contains other resin components such as polyurethane resin aqueous dispersions, the preferred amount is such that the various properties of the aqueous anticorrosive coating composition and the corrosion protection performance of the resulting coating film are not impaired. When the aqueous main component (I) further contains polyurethane resin aqueous dispersions in addition to epoxy resin aqueous dispersions (A), the content of polyurethane resin aqueous dispersions is preferably in the range of 0.5 to 20 parts by mass as resin solids per 100 parts by mass of resin solids of epoxy resin aqueous dispersion (A).

[0026] Inorganic rust-preventive pigment (B) Examples of inorganic rust-preventive pigments (B) included in the main component (I) include phosphate-based rust-preventive pigments, zinc oxide-based rust-preventive pigments, molybdenum-based rust-preventive pigments, boric acid-based rust-preventive pigments, borosilicate-based rust-preventive pigments, phosphate-silicic acid-based rust-preventive pigments, vanadic acid-based rust-preventive pigments, tungstic acid-based rust-preventive pigments, and the like. These inorganic rust-preventive pigments may be used individually, or two or more may be used in combination.

[0027] Examples of the phosphate-based rust-preventive pigments include oxymetallic salts of phosphorus. The metals include one or more metals selected from Mg, Ca, Ba, Sr, Zn, or Al. Examples of phosphorus oxyacids include phosphite, phosphate, and / or polyphosphate. Specific examples of phosphate-based rust-preventive pigments include, as phosphite metal salts, magnesium phosphite, calcium phosphite, barium phosphite, strontium phosphite, zinc phosphite, aluminum phosphite, zinc calcium phosphite, zinc potassium phosphite, etc. Examples of phosphate metal salts include magnesium phosphate, calcium phosphate, barium phosphate, strontium phosphate, zinc phosphate, aluminum phosphate, magnesium zinc phosphate, calcium zinc phosphate, zinc potassium phosphate, zinc potassium phosphate, etc. Examples of polyphosphate metal salts include aluminum pyrophosphate, calcium polyphosphate, magnesium polyphosphate, zinc polyphosphate, and aluminum polyphosphate. These compounds may be modified with silica or the like as needed.

[0028] Examples of the zinc oxide-based rust-preventive pigments include zinc oxide and modified zinc oxide. Examples of modified zinc oxide include zinc oxide modified with a metal salt such as a metal nitrite.

[0029] Examples of molybdenum-based rust-preventive pigments include metal molybdate salts. Examples of metal molybdate salts include zinc molybdate, calcium molybdate, barium molybdate, aluminum molybdate, magnesium molybdate, strontium molybdate, zinc calcium molybdate, and zinc potassium molybdate. Examples of phosphomolybdate salts include zinc molybdate, calcium molybdate, barium molybdate, aluminum molybdate, magnesium molybdate, strontium molybdate, and zinc potassium molybdate.

[0030] Examples of boric acid-based rust-preventive pigments include metal borate salts and metal metaborate salts. Examples of metal borate salts include zinc borate, calcium borate, barium borate, aluminum borate, magnesium borate, strontium borate, zinc calcium borate, and zinc potassium borate. Examples of metal metaborate salts include barium metaborate.

[0031] Examples of borosilicate-based rust-preventive pigments include metal borosilicate salts. Examples of metal borosilicate salts include zinc borosilicate, calcium borosilicate, barium borosilicate, aluminum borosilicate, magnesium borosilicate, strontium borosilicate, potassium zinc borosilicate, calcium zinc borosilicate strontium, and calcium calcium strontium zinc borosilicate.

[0032] Examples of phosphate-based rust-preventive pigments include metal phosphate salts. Examples of metal phosphate salts include zinc phosphate, calcium phosphate, barium phosphate, aluminum phosphate, magnesium phosphate, strontium phosphate, potassium zinc phosphate, calcium zinc phosphate, and calcium strontium zinc phosphate.

[0033] The metal salt may be a normal salt, a basic salt, or a complex salt, and may be hydrated or anhydrous.

[0034] In addition to the above, other examples of inorganic rust-preventive pigments include vanadic acid-based rust-preventive pigments and tungstic acid-based rust-preventive pigments. Other examples include cyanamide zinc calcium-based rust-preventive pigments and modified silica-based rust-preventive pigments in which metal cations such as calcium, zinc, cobalt, lead, strontium, and barium are bonded to porous silica particles.

[0035] Commercially available inorganic rust-preventive pigments (B) may be used. Examples of commercially available products include phosphate-based rust-preventive pigments such as LF-Bousei PM-300C (manufactured by Kikuchi Color Co., Ltd.) and K-White #140W (manufactured by Teika Co., Ltd.), molybdenum-based rust-preventive pigments such as LF-Bousei M-PSN (manufactured by Kikuchi Color Co., Ltd.), and zinc oxide-based rust-preventive pigments such as Zinc Oxide Type 2 (manufactured by Sakai Chemical Industry Co., Ltd.).

[0036] The inorganic rust-preventive pigment (B) may be used alone, or two or more may be used in combination. Preferably, the inorganic rust-preventive pigment (B) includes at least one selected from the group consisting of phosphate-based rust-preventive pigments, zinc oxide-based rust-preventive pigments, and molybdenum-based rust-preventive pigments, and more preferably includes at least one selected from the group consisting of phosphate-based rust-preventive pigments and molybdenum-based rust-preventive pigments. It may also include phosphate-based rust-preventive pigments and molybdenum-based rust-preventive pigments. According to the above embodiment, the coating film obtained from the aqueous anticorrosive paint composition can provide better corrosion protection to both steel and aluminum materials, and has the advantage of achieving particularly good long-term corrosion protection.

[0037] The amount of inorganic rust-preventive pigment (B) contained in the aqueous anticorrosive paint composition is preferably in the range of 10 to 80 parts by mass, and more preferably in the range of 15 to 60 parts by mass, per 100 parts by mass of resin solids contained in the aqueous anticorrosive paint composition. In this disclosure, unless otherwise specified, "resin solids contained in the aqueous anticorrosive paint composition" refers to the total resin solids of the epoxy resin aqueous dispersion (A) and the aromatic group-containing polyamine compound (D). Furthermore, if two or more of these are used, it refers to the total amount of their resin solids.

[0038] The aqueous main component (I) may further contain other pigments as needed, in addition to the inorganic rust-preventive pigment (B). The aqueous curing agent (II), described later, may also further contain other pigments as needed. Examples of other pigments include coloring pigments and extender pigments. Examples of coloring pigments include inorganic coloring pigments such as titanium dioxide, carbon black, iron oxide, and yellow iron oxide; and various organic coloring pigments, such as phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; azo pigments such as azo red, azo yellow, and azo orange; quinacridone pigments such as quinacridone red, syncasha red, and syncasha magenta; perylene pigments such as perylene red and perylene maroon; and carbazole violet, anthrapyridine, flavanthrone yellow, isoindoline yellow, induthrone blue, dibromoanzathrone red, anthraquinone red, and diketopyrrolopyrrole. Examples of extender pigments include calcium carbonate, precipitated barium sulfate, clay, and talc.

[0039] Thiazole compounds (C) The thiazole compound (C) contained in the aqueous curing agent (II) is a type of organic rust-preventive component. In the aqueous anticorrosive paint composition, by using the thiazole compound (C) together with the inorganic rust-preventive pigment (B), the coating obtained from the aqueous anticorrosive paint composition has the advantage of providing good corrosion protection to both steel and aluminum materials.

[0040] As the thiazole compound (C), a benzothiazole compound is preferred. Examples of benzothiazole compounds include, for example, mercaptobenzothiazole compounds such as 2-mercaptobenzothiazole and their salts; mercaptobenzothiazole disulfide (e.g., dibenzothiadyl disulfide); benzothiazole monocarboxylic acid compounds such as 3-(2-benzothiadylthio)propionic acid and (2-benzothiadylthio)acetic acid and their salts; (benzothiazole-2-ylthio)succinic acid, (2-benzothiazole-2-ylthio)succinic acid di-C 12-14Examples include benzothiazole dicarboxylic acid compounds such as alkylammonium salts and their salts. Examples of the salts include alkali metal salts or alkaline earth metal salts. These may be used individually or in combination.

[0041] In addition to the thiazole compound (C) mentioned above, other organic rust inhibitors may be used in combination. Examples of other organic rust inhibitors include ketocarboxylic acid-based organic rust inhibitors such as the addition reaction product of 4-methyl-γ-oxobenzenebutanoic acid and N-ethylmorpholine, and the addition reaction product of 4-methyl-γ-oxobenzenebutanoic acid and zirconium; paratert-butylbenzoic acid and its salts; and nitrite-based organic rust inhibitors such as dicyclohexylamine nitrite.

[0042] The amount of thiazole compound (C) contained in the aqueous anticorrosive coating composition is preferably in the range of 0.3 to 30 parts by mass, and more preferably in the range of 1 to 15 parts by mass, per 100 parts by mass of resin solids contained in the aqueous anticorrosive coating composition.

[0043] The mass ratio ((B):(C)) of the inorganic rust-preventive pigment (B) and the thiazole compound (C) contained in the aqueous anticorrosive paint composition is preferably in the range of 99.5:0.5 to 60:40, and more preferably in the range of 99:1 to 80:20. By having a mass ratio (B):(C) within the above range, the coating film obtained from the aqueous anticorrosive paint composition can provide better corrosion protection to both steel and aluminum materials, and in particular has the advantage of improving corrosion protection performance by improving initial adhesion.

[0044] Aromatic group-containing polyamine compounds (D) The aqueous curing agent (II) contains an aromatic group-containing polyamine compound (D). This aromatic group-containing polyamine compound (D) is a curing agent for the epoxy resin aqueous dispersion (A) contained in the aqueous main component (I). In this specification, "polyamine compound" means a compound having two or more amino groups. The amino groups of the polyamine compound may be primary amino groups, secondary amino groups, or may have both primary and secondary amino groups.

[0045] The aromatic group in the aromatic group-containing polyamine compound (D) may be an aromatic hydrocarbon group or a heteroaromatic group. The aromatic group may also be monocyclic or polycyclic. An example of an aromatic group-containing polyamine compound (D) is an aromatic compound having two or more alkylamino groups. The alkylamino group preferably has 1 to 10 carbon atoms. Specific examples of such compounds include orthoxylylenediamine, metaxylylenediamine, and paraxylylenediamine. Furthermore, phenalkamine compounds may be used as the aromatic group-containing polyamine compound (D).

[0046] The aromatic group-containing polyamine compound (D) preferably contains a hydroxyl group and an aromatic group-containing polyamine compound. The aromatic group-containing polyamine compound (D) has the advantage of having a hydroxyl group in addition to an aromatic group, resulting in good water solubility / water dispersibility in the aqueous curing agent (II). The aromatic group-containing polyamine compound (D) is preferably water-soluble.

[0047] The aromatic group-containing polyamine compound (D) preferably includes a polyamine compound having a hydroxyl group, a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and an aromatic group. The linear or branched hydrocarbon group having 6 to 30 carbon atoms may be a saturated hydrocarbon group or an unsaturated hydrocarbon group containing one or more unsaturated bonds. The number of carbon atoms in the aromatic group is, for example, 3 to 30, preferably 6 to 30.

[0048] As the aromatic group-containing polyamine compound (D), phenalkamine compounds are preferred. Phenalkamine compounds are polyamine compounds having a hydroxyl group (phenolic hydroxyl group), a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and an aromatic group. The polyamine portion constituting the phenalkamine compound has an ethylenediamine structure. Due to having the above structure, phenalkamine compounds have the advantages of being water-soluble, having good surface orientation of the coating film during application, and having good reactivity to the hydroxyl groups of epoxy resins, as well as having good water resistance, corrosion resistance, and adhesion to the material of the resulting coating film.

[0049] Phenalkamine compounds can be synthesized, for example, by the Mannich base reaction of alkylphenols, aldehydes, and amines (primary amines, secondary amines, etc.). Examples of amines used in the Mannich base reaction include ethylenediamine, diethyltriamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, isophoronediamine, and their condensation products. The amines may be mixtures.

[0050] Examples of alkylphenols used in the Mannich base reaction include phenols having linear or branched hydrocarbon groups with 6 to 30 carbon atoms. The alkylphenol may also be an extract. For example, a cardanol-containing extract obtained from cashew nut shell liquid can be used as the alkylphenol. The cardanol-containing extract is a known component described, for example, in International Publication No. 2004 / 024792.

[0051] Formaldehyde is preferably used as the aldehyde in the Mannich base reaction. The Mannich base reaction can be carried out under acidic or basic conditions, preferably under acidic conditions, under conditions known to those skilled in the art.

[0052] The aromatic group-containing polyamine compound (D) may also be a polyol-modified compound obtained by reacting some of the amino groups of the polyamine with the epoxy groups of the polyol-modified epoxy resin. By modifying some of the amino groups with polyol, hydrophilic groups are introduced, which has the advantage of improving water solubility or water dispersion performance.

[0053] The active hydrogen equivalent of the aromatic group-containing polyamine compound (D) is preferably in the range of 30 to 250 g / eq, and more preferably in the range of 50 to 200 g / eq. In this disclosure, the active hydrogen equivalent of the aromatic group-containing polyamine compound (D) is the solid content value (amine component amount) excluding the solvent, and can be calculated from the solid content amine value and structural formula measured in accordance with the provisions of JIS K 7237.

[0054] A commercially available product may be used as the aromatic group-containing polyamine compound (D). Examples of commercially available products include the Cardolite® series (manufactured by Cardolite), the Phenalkamine series (manufactured by Paladin), and the SUNMIDE series (manufactured by Evonik).

[0055] The ratio of the epoxy group content of the epoxy resin aqueous dispersion (A) contained in the aqueous main component (I) to the active hydrogen content of the aromatic group-containing polyamine compound (D) contained in the aqueous curing agent (II) [(Epoxy group content of (A): Active hydrogen content of (D)] is preferably in the range of 1:0.4 to 1:1.2, and more preferably in the range of 1:0.6 to 1:0.9. By having the ratio of the contents within the above range, better reactivity of the epoxy resin aqueous dispersion (A) and the aromatic group-containing polyamine compound (D) is ensured, and the coating film obtained from the aqueous anticorrosive paint composition has the advantage of being able to obtain good water resistance and corrosion resistance. In this disclosure, the epoxy group content means the value calculated as the amount of epoxy resin aqueous dispersion (g) / epoxy equivalent (g / eq), and the active hydrogen content means the value calculated as the amount of aromatic group-containing polyamine compound (g) / active hydrogen equivalent (g / eq). When two or more epoxy resin aqueous dispersions are used in combination, the epoxy group content of each is calculated and then summed up. Similarly, when two or more aromatic group-containing polyamine compounds are used in combination, the active hydrogen content of each is calculated and then summed up.

[0056] The number-average molecular weight of the aromatic group-containing polyamine compound (D) may be in the range of 200 to 20,000, preferably in the range of 300 to 15,000, and more preferably in the range of 1,000 to 10,000.

[0057] The aqueous curing agent (II) may optionally contain other polyamine compounds in addition to the aromatic group-containing polyamine compound (D). Examples of other polyamine compounds include polyalkyleneamines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentaamine, and pentaethylenehexaamine; aliphatic diamines such as 2,2,4- and / or 2,4,4-trimethylhexamethylenediamine, bis(3-aminopropyl)amine, 1,4-bis(3-aminopropyl)piperazine, N,N-bis(3-aminopropyl)ethylenediamine, neopentanediamine, 2-methyl-1,5-pentanediamine, 1,3-diaminopentane, and hexamethylenediamine; and 1,2- and 1,3-diamine. Examples include alicyclic amines such as nocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, 1,2-diamino-4-ethylcyclohexane, 1-cyclohexyl-3,4-diaminocyclohexane, isophorone diamines and their reaction products, 4,4'-diaminodicyclohexyl-methane and propane, bis(4-aminocyclohexyl)-methane and propane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3-amino-1-cyclohexylaminopropane, and 1,3- and 1,4-bis(aminomethyl)cyclohexane.

[0058] When other polyamine compounds are used in combination, the ratio of the epoxy group content of the epoxy resin aqueous dispersion (A) contained in the aqueous main component (I) to the active hydrogen content of the other polyamine compound contained in the aqueous curing agent (II) [(Epoxy group content of (A): Active hydrogen content of the other polyamine)] is preferably in the range of 1:0 to 1:0.8, and more preferably in the range of 1:0 to 1:0.5. Having the amount of the other polyamine compound within this range provides the advantage that the coating film obtained from the aqueous anticorrosive paint composition can be obtained with good corrosion resistance.

[0059] Preparation of water-based anticorrosive coating compositions and film formation The aqueous main component (I) and aqueous curing agent (II) of the aqueous paint composition can be prepared by mixing the various components by methods known to those skilled in the art. Furthermore, the method for preparing the paint composition can be one commonly used by those skilled in the art. For example, a kneading and mixing method using a kneader or roll, or a dispersion and mixing method using a sand grind mill or disperser, can be used, as commonly used by those skilled in the art.

[0060] The aqueous main component (I) and aqueous curing agent (II) of the aqueous coating composition may further contain other components used in the field of coating compositions, as needed. The other components are not particularly limited and include, for example, film-forming aids, ultraviolet absorbers, hindered amine light stabilizers, antioxidants, crosslinked resin particles, curing catalysts, pigment dispersants, settling inhibitors, defoaming agents, surfactants, thickeners, organic solvents, preservatives, surface modifiers, flash rust inhibitors, and the like.

[0061] The aforementioned aqueous anticorrosive coating composition can be applied to a material to be coated, forming a coating film that imparts corrosion resistance to the material. Regarding the timing of mixing the aqueous main component (I) and the aqueous curing agent (II) in the aqueous anticorrosive coating composition, the aqueous main component (I) and the aqueous curing agent (II) may be mixed before use and applied using a normal painting method. Alternatively, the two components may be mixed using a two-component mixing gun, with each component delivered to the gun and mixed at the tip of the gun.

[0062] Examples of substrates to which the water-based anticorrosive coating composition is applied include metal materials. Examples of metal materials include iron, steel, copper, aluminum, tin, zinc, and alloys containing these metals. The metal materials may be plated with zinc, copper, chromium, etc., or they may be surface-treated using surface treatment agents such as chromic acid, zinc phosphate, or zirconium salt. The substrates to which the water-based anticorrosive coating composition is applied may also include plastic materials. Examples of plastic materials include polypropylene resin, polycarbonate resin, polyurethane resin, polyester resin, polystyrene resin, ABS resin, vinyl chloride resin, and polyamide resin. These plastic materials may be primed. In addition to the above materials, the substrates to which the water-based anticorrosive coating composition is applied may also be wood, glass, cloth, concrete, ceramic materials, etc.

[0063] The aforementioned water-based anticorrosive coating composition has the advantage of providing good corrosion protection to various metal materials such as iron and aluminum. Therefore, the object to be coated may include, for example, both aluminum and iron materials.

[0064] The object to be coated with the aforementioned water-based anticorrosive paint may be a molded product containing the aforementioned material. Examples of molded products include automobile bodies, various vehicle bodies, and parts for home appliances. Specific examples of such objects to be coated include large objects (e.g., railway vehicles, ship hulls, buildings and structures); construction machinery (e.g., bulldozers, scrapers, hydraulic excavators, digging machines, transport machinery (trucks, trailers, etc.), cranes and cargo handling machinery, foundation work machinery (diesel hammers, hydraulic hammers, etc.), tunnel construction machinery (boring machines, etc.), road rollers, etc.); and industrial machinery such as general industrial equipment (low-voltage and heavy-voltage), agricultural machinery, steel furniture, machine tools and large vehicles; and so on.

[0065] The method for applying the water-based anticorrosive coating composition is not particularly limited, and examples include commonly used coating methods such as dipping, brushing, rolling, roll coater, air spray, airless spray, curtain flow coater, roller curtain coater, and die coater. In the case of spray coating, a two-component mixing gun may be used if necessary. These can be appropriately selected depending on the object to be coated.

[0066] The water-based anticorrosive coating composition is applied so that the dry film thickness after coating formation is 20 to 200 μm, preferably 30 to 100 μm. The curing temperature of the water-based coating composition is preferably in the range of 20°C to 150°C, and more preferably in the range of 40°C to 100°C. The curing time can be appropriately selected according to the curing temperature, and may be, for example, between 10 minutes and 7 days.

[0067] The aforementioned aqueous anticorrosive coating composition contains both an inorganic rust-preventive pigment (B) and a thiazole compound (C), and also contains an aromatic group-containing polyamine compound (D). As a result, the coating film obtained from the aqueous anticorrosive coating composition has the advantage of providing good corrosion protection to various metal materials, particularly both steel and aluminum materials. [Examples]

[0068] The present invention will be further described by the following examples, but the present invention is not limited thereto. In the examples, "parts" and "%" are based on mass unless otherwise specified.

[0069] Example 1 Manufacturing of aqueous main component (1) The epoxy resin aqueous dispersion (A-1) consists of 46.97 parts of BECKOPOX EP386w / 52WA (manufactured by Ornex Japan Co., Ltd.), the inorganic rust-preventive pigment (B-1) consists of 12.95 parts of LF Bousei PM-300C (phosphate-based rust-preventive pigment, manufactured by Kikuchi Color Co., Ltd.), 13.48 parts of TODA COLOR KN-R (coloring pigment, manufactured by Toda Pigment Co., Ltd.; solid content concentration: 100%), 0.5 parts of PRIMAL RM-12W (viscosity modifier, manufactured by Dow Chemical International Co., Ltd.; solid content concentration: 19%), 1.83 parts of SURFYNOL 440 (surface modifier, manufactured by Evonik Japan Co., Ltd.; solid content concentration: 100%), and Dispex Ultra 4.25 parts of PX4585 (wetting and dispersing agent, manufactured by BASF Japan; solids content: 50%), 0.28 parts of BYK-011 (defoaming agent, manufactured by Bic Chemie Japan; solids content: 30%), 3.68 parts of propylene glycol monomethyl ether, 3.52 parts of diethylene glycol monobutyl ether, and 8.45 parts of deionized water were mixed and stirred using a disperser to obtain aqueous main component (1).

[0070] Preparation of aqueous hardener (1) 9.53 parts of Cardolite NX-8101 (manufactured by Cardolite) as an aromatic group-containing polyamine compound (D-1), 2.02 parts of HALOX 350 (manufactured by ICL SPECIALTY PRODUCTS INC.) as a thiazole compound (C-1), 0.48 parts of TAP (curing accelerator; 2,4,6-tris(dimethylaminomethyl)phenol, manufactured by Tsukuno Foods Industry Co., Ltd.; solid content concentration: 88%), and 3.97 parts of ion-exchanged water were mixed and stirred using a disperser to obtain aqueous curing agent (1).

[0071] Coating of water-based anticorrosive paint compositions After solvent degreasing a 0.8mm thick, 70mm x 150mm JIS G 3141 (SPCC~SD) cold-rolled steel sheet, a paint composition containing Uniepoch 30 Primer NC (manufactured by Nippon Paint Industrial Coatings Co., Ltd.) as the main component and Uniepoch 30 Primer Hardener (manufactured by Nippon Paint Industrial Coatings Co., Ltd.) as the hardener was mixed using a disperser. The mixture was then applied using a spray gun to achieve a dry film thickness of 30-50 μm and dried at 23°C for one day. Next, a paint composition containing naxBES Non-Sample Primer Surfacer HS (manufactured by Nippon Paint Industrial Coatings Co., Ltd.) as the main component and naxBES Non-Sample Primer Surfacer Hardener HS (manufactured by Nippon Paint Industrial Coatings Co., Ltd.) as the hardener was mixed using a disperser and applied using a spray gun to a dry film thickness of 40-50 μm, and dried at 23°C for one day. Next, the aqueous main agent (1) and the water-dispersible curing agent (1) obtained above were mixed using a disperser so that the ratio of the epoxy group content of the epoxy resin aqueous dispersion (A) to the active hydrogen content of the aromatic group-containing polyamine compound (D) was [(A):(D)] = 1:0.75. Then, the mixture was applied to the surface of the surfacer coating using a spray gun to a dry film thickness of 30 to 50 μm, and dried at 60°C for 1 hour to obtain a corrosion-resistant coating.

[0072] Example 2 Aqueous main component (2) was obtained in the same manner as the production method for aqueous main component (1), except that 3.81 parts of polyurethane resin aqueous dispersion (NeoRez R-4000, manufactured by DSM Coating Resins) were further added to the aqueous main component (1) of Example 1. A corrosion-resistant coating film was obtained using the same procedure as in Example 1, except that aqueous main component (2) was used.

[0073] Examples 3-12, 14, 18-21, Reference Examples 13, 15-17, Comparative Examples 1-3 The aqueous main component and aqueous curing agent were prepared in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Tables 1 to 4 below. In Example 21 and Comparative Example 3, the amount of BECKOPOX EH613w / 80WA, an aliphatic group-containing polyamine compound, was set to 0.25 and 0.75 in terms of active hydrogen content, respectively, relative to the epoxy group content of (A). Using the obtained aqueous main component and aqueous curing agent, a corrosion-resistant coating film was obtained by the same procedure as in Example 1.

[0074] The corrosion-resistant coatings formed in the above examples and comparative examples were used for the following evaluations. The evaluation results are shown in Tables 1 to 4 below.

[0075] Coating film appearance evaluation The appearance of the coating was visually inspected. The evaluation criteria were as follows: 5: The paint leveling is good, the paint film is uniform, and there are no abnormalities. 4: The paint leveling is good, but the paint film is somewhat uneven. 3: The paint leveling was slightly poor, resulting in a somewhat uniform paint film. 2: Poor paint leveling results in an uneven paint film. 1: The paint leveling is extremely poor, resulting in an uneven paint film.

[0076] Water resistance evaluation Each test specimen was immersed in water at 20°C for 168 hours, after which the appearance of the coating was visually observed. The evaluation criteria were as follows: 5: No paint film abnormalities (blistering) occur. 4: There are blisters less than 1 mm in diameter on part of the paint film. 3: There are blisters on part of the coating that are between 1mm and 2mm in diameter. 2: There are blisters with a diameter of 2 mm or more on part of the paint film. 1: There are blisters of 2mm or more across the entire surface of the coating.

[0077] Corrosion resistance evaluation (SST, salt spray) Each test specimen was scored with a utility knife to create a 10 cm long cross-cut to reach the material. A salt spray test was then performed for 240 hours using a salt spray tester ST-11L (manufactured by Suga Test Instruments Co., Ltd.) according to the neutral salt spray resistance test method described in JIS K 5600-7-1 (JIS Z 2371). The occurrence of rust and blistering from the cross-cut area was visually evaluated. The evaluation criteria are as follows. 5: No rust or blistering occurs. 4: Rust or blistering less than 1 mm in size present at the cross-cut area. 3: Rust or blistering present at the cross-cut area, measuring between 1mm and 2mm in length. 2: Rust or blistering of 2mm or more from the cross-cut area. 1: Rust and blistering are present throughout.

[0078] Moisture resistance evaluation Each test specimen was placed in a humidity resistance tester (wetness tester CT-3, manufactured by Suga Test Instruments Co., Ltd.), and its appearance after 48 hours was visually evaluated according to the following criteria. ○: No rust, blistering, whitening, etc. have occurred. △: Slight rust, blistering, whitening, etc. are present. ×: Significant rust, blistering, whitening, etc.

[0079] [Table 1]

[0080] [Table 2]

[0081] TIFF0007831839000003.tif117170

[0082] [Table 4]

[0083] The components shown in the table above are as follows: Epoxy resin aqueous dispersion (A) Epoxy resin aqueous dispersion (A-1) BECKOPOX EP386w / 52WA (manufactured by Daicel Ornex), polyol-modified bisphenol A type epoxy resin; epoxy equivalent: 518 g / eq, number average molecular weight: 917, solids content: 52% Epoxy resin aqueous dispersion (A-2) BECKOPOX EP384w / 53WA (manufactured by Daicel Ornex), polyol-modified bisphenol A type epoxy resin; epoxy equivalent: 520 g / eq, number average molecular weight: 2,137, solids content: 53% Epoxy resin aqueous dispersion (A-3) BECKOPOX EP2307w / 45WAMP (manufactured by Daicel Ornex), polyol-modified bisphenol A type epoxy resin; epoxy equivalent: 1,980 g / eq, number average molecular weight: 5,735, solids content: 45% Epoxy resin aqueous dispersion (A-4) BECKOPOX EP2340w / 56WA (manufactured by Daicel Ornex), water-dispersible bisphenol A type epoxy resin; epoxy equivalent: 240 g / eq, number average molecular weight: 462, solids concentration: 56%

[0084] Inorganic rust-preventive pigment (B) Inorganic rust inhibitor (B-1) : Phosphate-based rust-preventive pigment, LF Bowsei PM-300C (aluminum tripolyphosphate-based, manufactured by Kikuchi Color Co., Ltd.) Inorganic rust inhibitor (B-2) : Phosphate-based rust-preventive pigment, K-White #140W (condensed aluminum phosphate type, manufactured by Teika Co., Ltd.) Inorganic rust inhibitor (B-3) : Molybdenum-based rust-preventive pigment, LF Bowsei M-PSN (zinc molybdate-based, manufactured by Kikuchi Color Co., Ltd.) Inorganic rust inhibitor (B-4) Zinc oxide-based rust-preventive pigments, two types of zinc oxide (zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd.)

[0085] Thiazole compounds (C) Thiazole compounds (C-1) :HALOX 350 (manufactured by ICL SPECIALTY PRODUCTS INC.), (benzothiazole-2-ylthio) succinate, solid content: 100% Thiazole compounds (C-2):Asconium142DA (manufactured by ASCOTEC), benzothiazole-2-thiol, solid content concentration: 32%

[0086] Aromatic group-containing polyamine compounds (D) Aromatic group-containing polyamine compound (D-1) NX-8101 (manufactured by Cardolite), phenalkamine-based modified aliphatic polyamine: Number of carbon atoms in linear or branched hydrocarbon groups: 15, Active hydrogen equivalent: 135 g / eq, Solids concentration: 50% Aromatic group-containing polyamine compounds (D-2) NX-8401 (manufactured by Cardolite), phenalkamine-based modified aliphatic polyamine: Number of carbon atoms in linear or branched hydrocarbon groups: 15, Active hydrogen equivalent: 164 g / eq, Solids concentration: 56.5% Aromatic group-containing polyamine compounds (D-3) Gaskamine 240 (manufactured by Mitsubishi Gas Chemical Co., Ltd.), active hydrogen equivalent: 103 g / eq, solid content concentration: 100%

[0087] Polyurethane resin aqueous dispersion NeoRez R-4000 (manufactured by DSM Coating Resins; solid content: 35%)

[0088] aliphatic group-containing polyamine compounds BECKOPOX EH613w / 80WA (manufactured by Ornex Japan), aliphatic polyamine: active hydrogen equivalent: 116g / eq, solids concentration: 80%

[0089] As shown in the table above, all of the corrosion-resistant coatings formed using the aqueous corrosion-resistant coating compositions of the examples were found to have a good coating appearance, and to have good water resistance, corrosion resistance, and moisture resistance. Comparative Example 1 is an example that does not include the inorganic rust-preventive pigment (B). In this example, it was confirmed that the water resistance, corrosion resistance, and moisture resistance were inferior. Comparative Example 2 is an example that does not contain the thiazole compound (C). In this example, it was confirmed that the water resistance, corrosion resistance, and moisture resistance were inferior. Comparative Example 3 is an example in which the curing agent polyamine compound does not contain aromatic groups. In this example, it was confirmed that the water resistance, corrosion resistance, and moisture resistance were significantly inferior. From Comparative Examples 1 to 3, it can be seen that the aqueous anticorrosive coating composition achieves good corrosion resistance by containing all of the specific components (A) to (D). [Industrial applicability]

[0090] The aforementioned water-based anticorrosive coating composition can, for example, impart corrosion resistance to metal materials, and in particular, can provide good corrosion resistance to both steel and aluminum materials.

Claims

1. A water-based anticorrosive coating composition comprising a water-based main component (I) and a water-based curing agent (II), wherein the water-based main component (I) and the water-based curing agent (II) are mixed before use, The aqueous main component (I) comprises an epoxy resin aqueous dispersion (A) and an inorganic rust-preventive pigment (B), and The aqueous curing agent (II) comprises an aromatic group-containing polyamine compound (D) and a thiazole compound (C), The inorganic rust-preventive pigment (B) includes one or more selected from the group consisting of phosphate-based rust-preventive pigments, molybdenum-based rust-preventive pigments, boric acid-based rust-preventive pigments, borosilicate-based rust-preventive pigments, phosphate-silicic acid-based rust-preventive pigments, vanadic acid-based rust-preventive pigments, and tungstic acid-based rust-preventive pigments. The mass ratio [(B):(C)] of the inorganic rust-preventive pigment (B) and the thiazole compound (C) contained in the aqueous anticorrosive paint composition is within the range of (B):(C) = 99.5:0.5 to 60:

40. The aromatic group-containing polyamine compound (D) includes a phenalkamine compound. A water-based anticorrosive coating composition.

2. The aqueous anticorrosive paint composition according to claim 1, wherein the inorganic anticorrosive pigment (B) comprises a phosphate-based anticorrosive pigment and a molybdenum-based anticorrosive pigment.

3. The aqueous anticorrosive coating composition according to claim 1 or 2, wherein the aromatic group-containing polyamine compound (D) comprises a hydroxyl group and an aromatic group-containing polyamine compound.

4. The aqueous anticorrosive coating composition according to any one of claims 1 to 3, wherein the aromatic group-containing polyamine compound (D) is water-soluble and comprises a polyamine compound having a hydroxyl group, a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and an aromatic group.

5. The aqueous anticorrosive coating composition according to any one of claims 1 to 4, wherein the epoxy equivalent of the epoxy resin aqueous dispersion (A) is in the range of 100 to 10,000 g / eq.

6. The aqueous anticorrosive coating composition according to any one of claims 1 to 5, wherein the ratio of the epoxy group content of the epoxy resin aqueous dispersion (A) contained in the aqueous main component (I) to the active hydrogen content of the aromatic group-containing polyamine compound (D) contained in the aqueous curing agent (II) is in the range of [epoxy group content of (A)] : [active hydrogen content of (D)] = 1 : 0.4 to 1 : 1.

2.

7. The aqueous corrosion-resistant coating composition according to any one of claims 1 to 6, further comprising an aqueous dispersion of polyurethane resin.

8. The aqueous anticorrosive coating composition according to any one of claims 1 to 7, wherein the thiazole compound (C) comprises a benzothiazole compound.

9. A water-based anticorrosive coating composition according to any one of claims 1 to 8, for use with aluminum and steel materials.

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