Anticorrosion coating composition

Abstract

To provide an anticorrosion paint composition that can form a coating film excellent in anticorrosion and water resistance, has a long pot life, and is excellent in drying and curability.SOLUTION: An anticorrosion paint composition comprises: an epoxy resin curable agent (A); a (meth) acrylic resin (B); a first agent containing water (D); and a second agent containing a non-aqueous epoxy resin (C) having an epoxy equivalent of 270 or smaller.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an anticorrosion coating composition, a coating film, a substrate with a coating film, and a method for producing the same. [Background technology]

[0002] BACKGROUND ART Conventionally, anticorrosion coating films have been provided on substrates of land and marine structures such as bridges, tanks, plants, and (transport) containers for the purpose of preventing corrosion.

[0003] In recent years, regulations on the content of volatile organic compounds (VOCs) have become stricter from the perspectives of environmental conservation and working environment safety, and there is a desire to switch from solvent-based paints to water-based paints for forming the above-mentioned anticorrosion coating films.

[0004] As such water-based paints, Patent Documents 1 and 2 describe natural drying (room temperature curing) water-based anticorrosive paints. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-222901 [Patent Document 2] Japanese Patent Application Publication No. 11-166153 Summary of the Invention [Problem to be solved by the invention]

[0006] Although the conventional water-based anticorrosion paints described in Patent Documents 1 and 2 above dry and harden to a certain extent at room temperature of about 23°C, the drying and hardening speed is not fast enough, and there is room for improvement, particularly with regard to the drying and hardening speed at low temperatures (e.g., 5°C) such as in winter.

[0007] Epoxy-amine paints are one example of paints with excellent corrosion resistance. To improve the drying and curing properties of such epoxy-amine paints, it is possible to increase the molecular weight of the epoxy resin or use a highly reactive amine. However, when the inventors tried these methods, they found that although the drying and curing properties improved, in the former case, the corrosion resistance decreased, and in the latter case, the pot life of the paint was shortened. In particular, there is a trade-off between excellent (fast) drying and curing properties of a paint and a long pot life of the paint, and conventional paints have not been able to achieve both.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide an anticorrosion coating composition that can form a coating film with excellent corrosion prevention and water resistance, has a long pot life, and is excellent in drying and curing properties. [Means for solving the problem]

[0009] As a result of extensive research into methods for solving the above problems, the inventors have found that a specific composition can solve the above problems, and have thus completed the present invention. An example of the configuration of the present invention is as follows.

[0010] <1> a first agent containing an epoxy resin curing agent (A), a (meth)acrylic resin (B), and water (D); and a second agent containing a non-aqueous epoxy resin (C) having an epoxy equivalent of 270 or less. Anticorrosive coating composition.

[0011] <2> The curing agent (A) comprises one or more selected from the group consisting of an aqueous amine curing agent (A1) and an aqueous amine-modified epoxy resin (A2). <1> The anticorrosion coating composition according to claim 1.

[0012] <3> The content of the nonvolatile content of the resin (B) is 20 to 95 mass% relative to 100 mass% of the total nonvolatile content of the curing agent (A), resin (B), and resin (C). <1> or <2> The anticorrosion coating composition according to claim 1.

[0013] <4> The volatile organic compound (VOC) content is 200g / L or less. <1> ~ <3> 1. The anticorrosion coating composition according to any one of claims 1 to 9.

[0014] <5> <1> ~ <4> A coating film formed from the anticorrosion coating composition according to any one of the preceding items. <6> Substrate and <5> and a substrate with a coating film comprising the coating film described in 1.

[0015] <7> A method for producing a substrate with a coating film, comprising the following steps [1] and [2]: [1] The substrate is <1> ~ <4> a step of applying the anticorrosion coating composition according to any one of [2] A step of drying the anticorrosion coating composition applied to the substrate to form a coating film. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide an anticorrosion coating composition that can form a coating film with excellent corrosion resistance and water resistance, has a long pot life (5 hours or more), and has excellent drying and curing properties (hereinafter simply referred to as "drying properties"). In particular, the anticorrosion coating composition of the present invention has a low VOC content, a long pot life, and a fast drying and curing rate even at low temperatures (e.g., 5°C) such as in winter, and therefore can significantly improve coating workability at the coating site compared to conventional coatings. DETAILED DESCRIPTION OF THE INVENTION

[0017] <Anti-corrosion coating composition> The anticorrosion coating composition according to the present invention (hereinafter also simply referred to as "the composition") comprises a first part containing an epoxy resin curing agent (A), a (meth)acrylic resin (B), and water (D), and a second part containing a non-aqueous epoxy resin (C) having an epoxy equivalent of 270 or less. In conventional compositions, a (meth)acrylic resin is often contained in a base resin containing an epoxy resin, but one of the features of the present composition is that an epoxy resin curing agent (A) and a (meth)acrylic resin (B) are blended in the first agent. This configuration of the present composition is thought to be one of the reasons why the present composition exhibits the above-mentioned effects that could not be achieved with conventional paints.

[0018] The present composition is not particularly limited as long as it is a multi-component composition containing the first and second agents, and depending on the components used, it may also be a three- or more-component composition containing a third agent other than the first and second agents. These first to third agents (hereinafter collectively referred to as "agent n") are usually stored, preserved, transported, etc. in separate containers, and are mixed together at the time of painting (e.g., immediately before painting) to form the present composition, which is then used. In other words, these agents n can be said to be components of a kit for preparing the present composition, and in other words, the present composition can be said to be a kit for anticorrosion coating compositions that includes the first agent and the second agent. In the present invention, agent n is an agent that can be stored after its preparation until the preparation of the present composition. For example, the mill-bases described in the examples below are usually mixed with other ingredients for use shortly after preparation of the mill-bases, and therefore do not fall under agent n in the present invention.

[0019] The present composition is prepared by mixing the agent n, but may be diluted after or during this preparation depending on the coating method and other factors. All descriptions in this specification, except for those relating to such dilution, are descriptions of the product before dilution.

[0020] Since this composition contains water (D), it is usually an aqueous coating composition. An aqueous coating composition is a composition in which components such as curing agent (A), resin (B), and resin (C) are dispersed and / or dissolved in water or a medium whose main component is water (aqueous medium). The water content in the aqueous coating composition is preferably 50% by mass or more, preferably 60 to 100% by mass, and more preferably 65 to 100% by mass, relative to 100% by mass of the total amount of the dispersion medium and solvent in the composition.

[0021] In environments where paint is applied to substrates such as containers, drying facilities may not be sufficient. When applying conventional water-based paints in such environments, emphasis is placed on drying speed, and large amounts of organic solvents have been blended into the paints. On the other hand, according to the present invention, a coating composition with excellent drying properties can be obtained, and therefore, even without blending a large amount of organic solvent, the desired coating film can be easily formed in places where drying equipment is insufficient and at low temperatures such as in winter. Therefore, from the viewpoints of environmental conservation and safety of the working environment, the content of volatile organic compounds (VOCs) in the composition is preferably 10% by mass or less, more preferably 8% by mass or less, and the VOC content in the composition is preferably 200 g / L or less, more preferably 180 g / L or less.

[0022] The VOC content in the composition can be calculated from the specific gravity of the composition, the heating residue percentage (mass ratio of non-volatile content), and the moisture content using the following formulas (1) and (2). The specific gravity of the composition, the heating residue percentage, and the moisture content may be measured values ​​as described below, or may be values ​​calculated from the raw materials used. VOC content (mass%)=(100-heating residue rate-moisture rate) / 100...(1) VOC content (g / L) = Composition specific gravity x 1000 x (100 - heating residual fraction - moisture percentage) / 100... (2)

[0023] Composition specific gravity (g / ml): A value calculated by filling a 100 ml specific gravity cup with this composition (the composition immediately after mixing with agent n) at a temperature of 23°C and measuring the mass of the composition.

[0024] Heating residue (mass %): 1±0.1 g of this composition (the composition immediately after mixing with agent n) or each component is weighed out onto a flat-bottomed dish, spread evenly using a wire of known mass, and heated at 125°C for 1 hour (at normal pressure), and the mass percentage is calculated by measuring the heating residue (non-volatile content) and the mass of the wire. Hereinafter, this heating residue of the composition is also referred to as the non-volatile content of the composition. Note that the non-volatile content of each component below (e.g., the non-volatile content of the curing agent (A)) refers to the components other than the solvent and dispersion medium in each component.

[0025] Moisture content (mass%): The mass percentage of water contained in 100 mass% of the composition, measured by the Karl Fischer method.

[0026] When the present composition is applied and dried at 23°C in accordance with ASTM D5895, the time required for the coating surface to reach a semi-cured (tack-free) state is preferably 10 to 60 minutes, more preferably 10 to 50 minutes, and the time required for the coating surface to reach a fully cured (dry-hard) state is preferably 10 to 90 minutes, more preferably 10 to 60 minutes. The composition of the present invention, for which each of these times (drying and curing rates) falls within the above ranges, can be said to have excellent drying properties, and can significantly improve coating workability compared to conventional paints, making it suitable for use on substrates that are difficult to heat when forming a coating film.

[0027] Furthermore, when the present composition is applied and dried at 5°C according to ASTM D5895, the time required for the coating surface to reach a semi-cured (tack-free) state is preferably 20 to 60 minutes, more preferably 20 to 50 minutes, and the time required for the coating surface to reach a completely cured (dry-hard) state is preferably 20 to 60 minutes, more preferably 20 to 50 minutes. The composition of the present invention, for which each of these times (drying and curing rates) falls within the above ranges, can be said to have excellent drying properties at low temperatures, and can significantly improve coating workability compared to conventional paints. It can also be suitably used for substrates that are difficult to heat when forming a coating film.

[0028] The pot life of the present composition, as measured by the method described in the examples below, is preferably 3 hours or more, more preferably 5 hours or more. The present composition can be made into a composition having a pot life within the above range and a drying and curing rate within the above range, thereby significantly improving the coating workability compared to conventional paints.

[0029] The present composition is suitable for use on substrates such as steel (iron, steel, ferroalloy, carbon steel, mild steel, alloy steel, etc.), non-ferrous metals (zinc, aluminum, copper, brass, zinc plating, zinc thermal spraying, etc.), and stainless steel (SUS304, SUS410, etc.), and is particularly suitable for use on substrates made of steel or stainless steel. Specific examples of such substrates include (large) steel or stainless steel structures such as ships, marine structures, plants, bridges, tanks, and containers (especially reefer containers).

[0030] The present composition can be suitably used as an anticorrosion coating composition for the above substrates. The present composition may be used as an undercoat paint (primer) for the substrate, as an intermediate coat paint formed between the undercoat paint and the topcoat paint, or as a topcoat paint. More specifically, the present composition can be suitably used as an undercoat paint for the substrate, an intermediate coat paint, a topcoat paint for the inner surfaces of tanks, containers, etc., or a zinc primer containing zinc powder.

[0031] <First agent> The first part of the composition is not particularly limited as long as it contains an epoxy resin curing agent (A), a (meth)acrylic resin (B), and water (D). The first agent may contain other components, such as pigments (E) (e.g., extender pigments, color pigments, and anti-rust pigments), flash rust inhibitors, dispersants, antifoaming agents, thixotropic agents (anti-sagging and anti-settling agents), leveling agents, wetting agents, thickeners, film-forming aids, plasticizers, driers, fibrous substances, surfactants, organic solvents, mildew inhibitors, preservatives, ultraviolet absorbers, light stabilizers, and pH adjusters, as needed, within the scope of the invention. These may be used alone or in combination of two or more. From the viewpoint of ease of application, it is preferable that the present composition does not contain sand.

[0032] [Epoxy resin hardener (A)] The curing agent (A) is not particularly limited as long as it contains active hydrogen and reacts with the epoxy resin (C), and examples thereof include amine curing agents and acid anhydride curing agents. Among these, amine curing agents are preferred because they can easily form a coating film with excellent corrosion resistance. The curing agent (A) contained in the present composition may be one type or two or more types.

[0033] Since the first agent of the present composition contains water (D), it is preferably an aqueous compound that is dispersible or soluble in water. Suitable examples of such aqueous compounds include aqueous amine curing agents (A1) and aqueous amine-modified epoxy resins (A2), and more preferably at least one selected from the group consisting of aqueous amine curing agents (A1) and aqueous amine-modified epoxy resins (A2).

[0034] The content of the nonvolatile content of the curing agent (A) in the present composition is preferably 0.5 to 20 mass%, more preferably 1 to 15 mass%, relative to 100 mass% of the nonvolatile content of the present composition, from the viewpoint that a composition with excellent drying properties can be easily obtained and a coating film with excellent water resistance and corrosion resistance can be easily formed.

[0035] <Aqueous amine curing agent (A1)> Examples of the curing agent (A1) include water-soluble amine compounds and amine emulsions. Examples of the water-soluble amine compound include the following amine compounds and compounds obtained by making the following amine compounds hydrophilic by a known method. Examples of the method for making the compounds hydrophilic include introducing a group that promotes water solubility, such as a carboxy group, a sulfonic acid group, a sulfinic acid group, a phosphonic acid group, or a hydroxyl group, and introducing a hydrophilic group by, for example, adduct-modifying a glycidyl ether of a polyalkylene glycol. The water-soluble amine compound refers to a compound that is transparent in appearance when 30% by mass of water and 70% by mass of the amine compound are mixed at 25°C and thoroughly stirred. The amine emulsion may be, for example, an emulsion in which the following amine compounds are dispersed in an aqueous medium such as water. As the curing agent (A1), one type may be used, or two or more types may be used.

[0036] The amine compound is not particularly limited as long as it is an amine compound other than a tertiary amine (an amine compound having only a tertiary amino group), but examples thereof include amine compounds containing two or more amino groups in one molecule, and aliphatic, alicyclic, aromatic, and heterocyclic amine compounds are preferred.

[0037] Examples of the aliphatic amine compounds include alkylene polyamines, polyalkylene polyamines, and alkylamino alkyl amines.

[0038] Examples of the alkylene polyamine include those represented by the formula: "H2N-R 1 -NH2" (R 1 is a divalent hydrocarbon group having 1 to 12 carbon atoms. Specific examples include methylenediamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, and trimethylhexamethylenediamine.

[0039] Examples of the polyalkylene polyamine include those of the formula: "HN-(C m H 2m NH) n Specific examples include compounds represented by the formula (III) (H) (where m is an integer of 1 to 10, and n is an integer of 2 to 10, preferably an integer of 2 to 6), such as diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, bis(hexamethylene)triamine, and triethylene-bis(trimethylene)hexamine.

[0040] Examples of the alkylaminoalkylamine include those represented by the formula: 2 2N-(CH2) p -NH2" (R 2 are independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (provided that at least one R 2 is an alkyl group having 1 to 8 carbon atoms, and p is an integer of 1 to 6. Specific examples include dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, and dimethylaminobutylamine.

[0041] Other aliphatic amines include, for example, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, polyoxyalkylenepolyamines (particularly, diethylene glycol bis(3-aminopropyl)ether), bis(aminomethyl)cyclohexane, isophoronediamine (IPDA), menthenediamine (MDA), o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, 1,4-bis(3-aminopropyl)piperazine, 1-(2'-aminoethylpiperazine), and 1-[2'-(2''-aminoethylamino)ethyl]piperazine.

[0042] Specific examples of the alicyclic amine include cyclohexanediamine, diaminodicyclohexylmethane (particularly, 4,4'-methylenebiscyclohexylamine), 4,4'-isopropylidenebiscyclohexylamine, norbornanediamine, and 2,4-di(4-aminocyclohexylmethyl)aniline.

[0043] Examples of the aromatic amine include aromatic polyamine compounds having two or more primary amino groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring. Specific examples of the aromatic amine include phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, diaminodiethylphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, and 3,3'-dimethoxy-4,4'-diaminobiphenyl.

[0044] Specific examples of the heterocyclic amine include 1,4-diazacycloheptane, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

[0045] The amine compound further includes modified products of the above-mentioned amines, for example, fatty acid modified products such as polyamidoamine, amine adducts with epoxy compounds, Mannich modified products (e.g., phenalkamine, phenalkamide), Michael adducts, ketimines, and aldimines. Among these, polyamidoamine, amine adducts with epoxy compounds, and Mannich modified products are preferred.

[0046] The water-soluble amine compound may be a commercially available product, such as "Daitoclar I-6020" (manufactured by Daito Sangyo Co., Ltd.), "Cardolite NX-8102" (manufactured by Cardolite Corporation), "Ancamine 401" (manufactured by Evonik Industries), "Beckopox EH 613w / 80WA" (manufactured by ALLNEX), or "Sunmide WH-900" (manufactured by Evonik Industries).

[0047] Commercially available amine emulsions can be used, and examples of such commercially available products include "Fujicure FXS-918-FA" (manufactured by T&K TOKA Corporation), "EPILINK 701" (manufactured by Evonik Industries), and "Yukaresin HD-03" (manufactured by Yoshimura Oil Chemical Co., Ltd.).

[0048] The curing agent (A1) is preferably a water-soluble amine compound, particularly a water-soluble polyamine, from the viewpoints of miscibility with the (meth)acrylic resin (B) described below, storage stability after mixing with other components used in the first agent, and the like.

[0049] The active hydrogen equivalent per nonvolatile content of the curing agent (A1) is preferably 30 to 500, more preferably 40 to 300, from the viewpoints that a composition with excellent drying properties can be easily obtained and a coating film with excellent corrosion resistance can be easily formed.

[0050] <Water-based amine-modified epoxy resin (A2)> The resin (A2) is not particularly limited, but specifically includes a reaction product of one or more epoxy resins (a1) with one or more amines (a2), and is preferably an aqueous resin having one or more carboxy groups in one molecule and an acid value of the nonvolatile matter of 1 to 20 mgKOH / g. By using such a resin (A2), a composition with superior drying properties can be easily obtained, and a coating film with superior corrosion resistance and adhesion to the substrate can be easily formed. The resin (A2) in the present invention refers to a resin in which the monomer components constituting the epoxy resin exceed 50% by mass relative to 100% by mass of all the monomer components constituting the resin. As the resin (A2), one type may be used, or two or more types may be used.

[0051] In the present invention, the term "aqueous resin" refers to a resin that uses water or water as the main solvent or dispersion medium, or a resin that is miscible with water (dilutable with water). More specifically, examples include water-dispersible resins, water-soluble resins, and self-emulsifying resins. Such aqueous resins can be synthesized by conventionally known methods, such as solution polymerization, suspension polymerization, emulsion polymerization, seed polymerization, miniemulsion polymerization, microemulsion polymerization, and emulsifier-free (soap-free) emulsion polymerization. In addition to these methods, aqueous resins can also be obtained by emulsifying resins using known methods, such as phase inversion emulsification, D-phase emulsification, forced emulsification, gel emulsification, inversion emulsification, and high-pressure emulsification.

[0052] In addition, even if a resin does not have an epoxy group, if the resin is made from a compound having an epoxy group as a raw material, a common name including the word "epoxy" is used. Therefore, the "epoxy resin" in the present invention also includes a resin that does not have an epoxy group.

[0053] The epoxy equivalent of the non-volatile content of the resin (A2) is preferably 1500 or more, more preferably 2000 or more, from the viewpoint that a composition having excellent drying properties can be easily obtained, and it is particularly preferable that the resin (A2) does not have an epoxy group. The epoxy equivalent can be measured in accordance with JIS K 7236:2001.

[0054] The acid value of the nonvolatile content of the resin (A2) is preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, and preferably 1 mgKOH / g or more, more preferably 2 mgKOH / g or more. By using a resin (A2) having an acid value within the above range, a composition with excellent drying properties can be easily obtained, and a coating film with excellent corrosion resistance can be easily formed. The acid value can be measured in accordance with JIS K 0070:1992.

[0055] The amine value of the nonvolatile content of the resin (A2) is preferably 150 mgKOH / g or less, more preferably 100 mgKOH / g or less, and preferably 1 mgKOH / g or more, more preferably 25 mgKOH / g or more. By using a resin (A2) having an amine value within the above range, a composition with excellent drying properties can be easily obtained, and a coating film with excellent corrosion resistance can be easily formed. The amine value can be measured in accordance with JIS K 7273:1995.

[0056] The amines (a2) are not particularly limited, and examples thereof include monoamines and polyamines such as aliphatic amines, alicyclic amines, aromatic amines, araliphatic amines, and heterocyclic amines. The amines may be used alone or in combination of two or more.

[0057] The amines are not particularly limited, and examples thereof include primary alkylamines such as butylamine, octylamine, oleylamine, and 2-ethylhexylamine; primary alkanolamines such as monoethanolamine, 2-ethoxyethanolamine, and 2-hydroxypropanolamine; aliphatic polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; alicyclic polyamines such as 1,3-diaminocyclohexane and isophoronediamine; aromatic polyamines such as diaminodiphenylmethane; aromatic aliphatic amines such as o-xylylenediamine, m-xylylenediamine, and p-xylylenediamine; Mannich bases formed from polycondensates of polyamines, aldehyde compounds, and monohydric or polyhydric phenols; polyamide polyamines obtained by reacting polyamines with polycarboxylic acids or dimer acids; and polyoxyalkylene amines such as polyoxyethylene amines and polyoxypropylene amines. In view of excellent dispersibility in an aqueous medium and excellent storage stability of a dispersion dispersed in an aqueous medium, primary alkylamines, primary alkanolamines, and polyoxyalkyleneamines are preferred, and primary alkanolamines and polyoxyalkylenepolyamines are more preferred.

[0058] Examples of the polyoxyalkyleneamines include compounds represented by the following structural formula (a2-1).

[0059] [ka] [In the formula, R 1 is a hydrogen atom, a methyl group, an ethyl group, a propyl group, or a t-butyl group, and R 2 are independently an ethylene group, a 1,2-propylene group, a 2,3-propylene group, or a 1,3-propylene group; R 3 represents a methylene group, an ethylene group, a 1,2-propylene group, a 2,3-propylene group, or a 1,3-propylene group, and n represents the average value of the repeating units and is from 2 to 100.]

[0060] The molecular weight of the polyoxyalkyleneamines is preferably 300 to 5,000 in weight average molecular weight (Mw), more preferably 400 to 1,500, from the viewpoint that a composition excellent in storage stability and anticorrosion properties can be easily obtained.

[0061] The polyoxyalkyleneamines may be commercially available products, such as "JEFFAMINE M-600" (weight average molecular weight: 600), "JEFFAMINE M-1000" (weight average molecular weight: 1,000), "JEFFAMINE M-2005" (weight average molecular weight: 2,000), and "JEFFAMINE M-2070" (weight average molecular weight: 2,000) (all manufactured by Huntsman). Of these, "JEFFAMINE M-600" and "JEFFAMINE M-1000" are preferred.

[0062] As the epoxy resin (a1), from the viewpoints of the toughness of the resulting coating film and adhesion to the substrate, a bisphenol type epoxy resin is preferred, and bisphenol A type epoxy resin, bisphenol F type epoxy resin, or bisphenol AD ​​type epoxy resin is preferred, with bisphenol A type epoxy resin being more preferred. The epoxy resin (a1) may be used alone or in combination of two or more.

[0063] In order for the reaction product to be a resin having one or more carboxy groups in the molecule, a compound having a carboxy group may be used as the epoxy resin (a1), or a compound having a carboxy group may be used as the compound (a2), and a carboxy group may be generated during the reaction of these, or after the reaction, modification may be performed so that the final resin has a carboxy group. However, it is preferable to use an unsaturated carboxylic acid (a3) ​​other than the epoxy resin (a1) and the compound (a2) during the reaction.

[0064] The unsaturated carboxylic acid (a3) ​​may be, for example, (meth)acrylic acid, which may be used alone or in combination of two or more.

[0065] The order in which the epoxy resin (a1), compound (a2), and unsaturated carboxylic acid (a3) ​​are reacted is not particularly limited. However, from the viewpoint of easily obtaining a resin that satisfies the acid value and amine value as described above, it is preferable to react the epoxy resin (a1) with the compound (a2) (hereinafter also referred to as "reaction 1") and then react the compound obtained in reaction 1 with the unsaturated carboxylic acid (a3) ​​(hereinafter also referred to as "reaction 2"). These reactions 1 and 2 can be carried out by conventionally known methods.

[0066] The mixing ratio of the epoxy resin (a1) and the compound (a2) in the above reaction 1 is preferably such that as few epoxy groups as possible remain in the resulting resin (A2), since if epoxy groups remain in the resulting resin (A2), the storage stability of the composition may decrease. For example, the amount of amino groups per mole of epoxy groups is preferably about 1.1 to 1.5 moles, more preferably about 1.1 to 1.3 moles.

[0067] In the reaction 2, the compound obtained in the reaction 1 and the unsaturated carboxylic acid (a3) ​​are mixed preferably in an amount of about 1.1 to 1.5 moles, more preferably about 1.1 to 1.3 moles, of carboxyl groups per mole of amino groups, since the corrosion resistance of the resulting coating film may be reduced if primary or secondary amino groups remain in the resulting resin (A2).

[0068] The resin (A2) may be a commercially available product, such as EPICLON C-250EP (manufactured by DIC Corporation, epoxy group-free, acid value of non-volatile matter: 5.7 mg KOH / g, amine value of non-volatile matter: 60 mg KOH / g), which is an aqueous amine-modified epoxy resin having a bisphenol A structure and one or more carboxy groups per molecule.

[0069] The content of the nonvolatile components (resin) in 100% by mass of the resin (A2) is preferably 30 to 75% by mass, more preferably 35 to 60% by mass, from the viewpoint of obtaining a composition that is easier to prepare and has better storage stability. The remainder of the resin (A2) preferably contains water, and may contain conventionally known components such as surfactants, if necessary.

[0070] [(Meth)acrylic resin (B)] The resin (B) is a resin other than the curing agent (A), and is not particularly limited as long as it is a resin obtained by using a (meth)acrylic compound as a monomer. However, from the viewpoint of easily obtaining the present composition having excellent storage stability, the (meth)acrylic resin (B) used in preparing the present composition is preferably an aqueous resin, and is in the form of an emulsion (including latex). It is more preferable that This composition contains a curing agent (A) and water (D) as the first agent, and a resin (C) as the second agent. By blending the resin (B) into the first agent, it is possible to easily obtain a composition that has a particularly long pot life and excellent drying properties, and to easily form a coating film that is excellent in water resistance. The resin (B) contained in the present composition may be one type or two or more types.

[0071] In the present invention, (meth)acrylic means acrylic and / or methacrylic. Similar expressions have similar meanings. That is, the (meth)acrylic resin (B) may be an acrylic resin or a methacrylic resin.

[0072] Examples of the resin (B) include homopolymers or copolymers of (meth)acrylic monomers, and copolymers of (meth)acrylic monomers and other monomers.

[0073] Examples of the (meth)acrylic monomer include: (Meth)acrylic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; (Meth)acrylic acid cycloalkyl esters such as cyclohexyl (meth)acrylate; (Meth)acrylic acid aryl esters such as phenyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate; alkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and diethylaminopropyl (meth)acrylate; (meth)acrylamides or derivatives thereof such as (meth)acrylamide, N-methyl(meth)acrylamide, methylol(meth)acrylamide, and alkoxymethyl(meth)acrylamide; Epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; Examples include: These (meth)acrylic monomers may be used alone or in combination of two or more.

[0074] The (meth)acrylic monomer preferably contains at least one monomer selected from (meth)acrylic acid and (meth)acrylic acid alkyl esters, more preferably contains at least one monomer selected from (meth)acrylic acid, methyl (meth)acrylate, butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate, and it is particularly preferable to contain at least 2-ethylhexyl (meth)acrylate, since a coating film with excellent water resistance can be easily formed.

[0075] Examples of other monomers that can be copolymerized with the (meth)acrylic monomer include: Aromatic vinyl monomers such as styrene, α-methylstyrene, pt-butylstyrene, and vinyltoluene; nitrile group-containing monomers such as acrylonitrile and methacrylonitrile; Fatty acid vinyl ester monomers such as vinyl propionate; Unsaturated polycarboxylic acids or anhydrides thereof, such as maleic anhydride, maleic acid, fumaric acid, and itaconic acid; Esters of unsaturated polycarboxylic acid derivatives such as dimethyl maleate and diethyl fumarate; N-substituted maleimides such as N-phenylmaleimide; olefinic monomers such as ethylene and propylene; Examples include: These monomers may be used alone or in combination of two or more.

[0076] The other monomers preferably contain an aromatic vinyl monomer, more preferably contain styrene, and particularly preferably contain styrene but do not contain a nitrile group-containing monomer, particularly acrylonitrile, from the viewpoint of being able to easily form a coating film having excellent water resistance.

[0077] The acid value of the nonvolatile content of the resin (B) is preferably 10 to 70 mgKOH / g, more preferably 20 to 60 mgKOH / g. By using a resin (B) having an acid value within the above range, a composition with excellent drying properties can be easily obtained, and a coating film with excellent corrosion resistance can be easily formed. The acid value can be measured in accordance with JIS K 0070:1992.

[0078] The weight average molecular weight (Mw) of the non-volatile content of resin (B) measured by gel permeation chromatography (GPC) is preferably 50,000 to 200,000, and more preferably 80,000 to 160,000, from the viewpoints that a composition with excellent coating performance can be obtained and a coating film with excellent coating film properties can be easily obtained.

[0079] The content of the nonvolatile content of resin (B) in the present composition is preferably 1 to 50 mass %, more preferably 3 to 40 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoints that a composition having a long pot life and excellent drying properties can be easily obtained, and a coating film having excellent water resistance can be easily formed.

[0080] For example, when the composition is used as an undercoat paint, intermediate coat paint or topcoat paint, the content of the nonvolatile content of resin (B) in the composition is preferably 5 to 50 mass %, more preferably 10 to 40 mass %, based on 100 mass % of the nonvolatile content of the composition, for the same reasons as above.Furthermore, when the composition is used as a zinc primer, the content of the nonvolatile content of resin (B) in the composition is preferably 1 to 10 mass %, based on 100 mass % of the nonvolatile content of the composition, for the same reasons as above.

[0081] For the same reasons as above, the content of the nonvolatile content of the resin (B) in the present composition is preferably 20 to 95 mass%, more preferably 25 to 90 mass%, relative to 100 mass% of the total nonvolatile content of the curing agent (A), resin (B), and resin (C).

[0082] For example, when the composition is used as an undercoat paint, intermediate coat paint or topcoat paint, the content of the nonvolatile content of resin (B) in the composition is preferably 25 to 90 mass% based on 100 mass% of the total nonvolatile content of the curing agent (A), resin (B) and resin (C), for the same reasons as above. Also, when the composition is used as a zinc primer, the content of the nonvolatile content of resin (B) in the composition is preferably 20 to 60 mass% based on 100 mass% of the total nonvolatile content of the curing agent (A), resin (B) and resin (C), for the same reasons as above.

[0083] [Water(D)] The curing agent (A) and the resin (B) may contain water, and it is preferable that the curing agent (A) and the resin (B) contain water. Therefore, the water contained in the curing agent (A) and the resin (B) may be used as water (D), but from the viewpoints of making it easier to prepare the present composition and easily obtaining a composition with better storage stability and coating workability, it is preferable to further blend water (D) in addition to the water that may be contained in the curing agent (A) and the resin (B). The water (D) is not particularly limited, and tap water or the like may be used, but ion-exchanged water or the like is preferably used.

[0084] The content of water in the first part (including water that may be contained in the curing agent (A) and the resin (B)) is not particularly limited, but is preferably 10 to 50% by mass. Furthermore, the content of water in the first agent is preferably 50% by mass or more, more preferably 70 to 100% by mass, and particularly preferably 80 to 100% by mass, relative to 100% by mass of the total amount of the dispersion medium and solvent in the first agent, in order to facilitate the production of the desired aqueous coating composition.

[0085] Pigment The present composition preferably contains a pigment (excluding zinc dust and flash rust inhibitors) from the viewpoint of imparting coating film strength, corrosion resistance, hue, etc. Examples of such pigments include extender pigments, color pigments, and anti-rust pigments, and may be either organic or inorganic. As the pigment (E), one type may be used, or two or more types may be used.

[0086] As the extender pigment, any conventionally known extender pigment can be used, and examples thereof include (precipitated) barium sulfate, (potassium) feldspar, alumina white, magnesium carbonate, barium carbonate, calcium carbonate, dolomite, silica, talc, mica, kaolin, glass flakes, and plastic flakes.

[0087] When the present composition contains an extender pigment, the content thereof is preferably 1 to 70% by mass, and more preferably 1.5 to 60% by mass, relative to 100% by mass of the nonvolatile content of the present composition.

[0088] When the present composition contains an extender pigment, for example, when the present composition is used as an undercoat paint, intermediate coat paint or topcoat paint, the content of the extender pigment in the present composition is preferably 30 to 70 mass %, more preferably 40 to 60 mass %, based on 100 mass % of the nonvolatile content of the present composition. Also, when the present composition is used as a zinc primer, for example, the content of the nonvolatile content of the extender pigment in the present composition is preferably 1 to 10 mass % based on 100 mass % of the nonvolatile content of the present composition.

[0089] As the color pigment, a conventionally known color pigment can be used, and examples thereof include inorganic pigments such as carbon black, titanium dioxide (titanium white), iron oxide (red iron oxide), yellow iron oxide, and ultramarine, organic pigments such as cyanine blue and cyanine green, and glossy pigments such as flaky iron oxide and stainless steel flakes.

[0090] When the present composition contains a color pigment, the content thereof is preferably 0.01 to 30% by mass, and more preferably 0.1 to 25% by mass, relative to 100% by mass of the nonvolatile content of the present composition.

[0091] As the anti-rust pigment, can be used conventionally known anti-rust pigment, for example, aluminum phosphate compound, zinc phosphate compound, calcium phosphate compound, magnesium phosphate compound, zinc phosphite compound, calcium phosphite compound, aluminum phosphite compound, strontium phosphite compound, zinc molybdate compound, aluminum molybdate compound, aluminum tripolyphosphate compound, zinc tripolyphosphate compound, zinc borate compound, barium borate compound, metal ion exchange silica compound.Among these, aluminum phosphate compound and zinc phosphate compound are preferred from the viewpoint of being able to easily obtain a coating film with better corrosion prevention properties, and metal ion exchange silica compound is preferred from the viewpoint of being able to easily form a coating film with excellent adhesion to non-ferrous metal substrate or stainless steel substrate, and calcium ion exchange silica compound and magnesium ion exchange silica compound are more preferred.

[0092] Commercially available examples of such anti-rust pigments include LF Bousei PW2 (manufactured by Kikuchi Color Co., Ltd.) as a zinc phosphate, LF Bousei PM-303W (manufactured by Kikuchi Color Co., Ltd.) as an aluminum phosphate, K-WHTE #140W (manufactured by Teika Corporation) as an aluminum tripolyphosphate compound, Silomask 55 (manufactured by Fuji Silysia Chemical Ltd.) as a calcium ion-exchanged silica compound, and Silomask 52 (manufactured by Fuji Silysia Chemical Ltd.) as a magnesium ion-exchanged silica compound.

[0093] When the present composition contains an anti-rust pigment, the content thereof is preferably 0.5 to 15 mass %, more preferably 1 to 10 mass %, relative to 100 mass % of the nonvolatile content of the present composition.

[0094] [Thixotropic agents (anti-sagging / anti-settling agents)] The present composition preferably contains a thixotropic agent to improve thick coating properties and sagging prevention during application, and to prevent the settling of zinc dust, pigments, and other components that are insoluble in water or organic solvents. As the thixotropic agent, one type may be used, or two or more types may be used.

[0095] Examples of thixotropic agents include organic clay salts such as stearates, lecithin salts, and alkylsulfonates of Al, Ca, and Zn, clays such as bentonite clay and hectorite clay, and organically modified versions of these clays (e.g., organically modified hectorite clay), oxidized polyethylene wax, ethylene-vinyl acetate wax, polyamide wax, hydrogenated castor oil wax, and synthetic finely divided silica. Among these, organic thixotropic agents such as organically modified hectorite clay, oxidized polyethylene wax, ethylene-vinyl acetate wax, and polyamide wax are preferred because they can easily form coating films with excellent crack resistance.

[0096] When the present composition contains a thixotropic agent, the content thereof is preferably 0.01 to 3.5 mass %, more preferably 0.05 to 3 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoint of easily forming a coating film with excellent crack resistance, etc.

[0097] [Dispersant] The present composition preferably contains a dispersant, since this improves the dispersibility of zinc dust, pigments, etc. in the composition, making it possible to easily form a coating film with a good appearance and excellent crack resistance. As the dispersant, one type may be used, or two or more types may be used.

[0098] The dispersant is not particularly limited, but examples thereof include various dispersants such as copolymers having a pigment-adsorbing group (pigment-affinity group) such as a carboxyl group, a phosphate group, an amino group, a salt group of these, or an ammonium base, and having a compatible chain such as a fatty acid, polyamino, polyether, polyester, polyurethane, or polyacrylate.

[0099] When the present composition contains a dispersant, the content thereof is preferably 0.1 to 3 mass %, more preferably 0.1 to 2.5 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoint of easily forming a coating film with excellent crack resistance, etc.

[0100] [Flash rust prevention agent] When a water-based paint is applied to an active steel surface, the elution of iron ions from the steel surface during the drying process can cause rusting and flash rust, which appears on the surface of the paint film. Flash rust can be particularly pronounced under high-temperature and high-humidity conditions. In order to suppress such flash rust, it is preferable to use a flash rust inhibitor in the present composition. As the flash rust inhibitor, one type may be used, or two or more types may be used.

[0101] Examples of flash rust inhibitors include nitrites such as sodium nitrite, potassium nitrite, calcium nitrite, strontium nitrite, barium nitrite, and ammonium nitrite; benzoates such as sodium benzoate, potassium benzoate, calcium benzoate, and ammonium benzoate; phytates such as sodium phytate and potassium phytate; salts of fatty acids such as sebacic acid and dodecanoic acid; phosphoric acid derivatives such as alkyl phosphates and polyphosphates; tannates; N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), and diethylene Examples of suitable chelating agents include amine-based chelating agents such as triaminepentaacetic acid (DTPA), propylenediaminetetraacetic acid (PDTA), iminodiacetic acid, nitrilotriacetic acid (NTA), diethylenetriaminepentamethylenephosphonic acid (DTPMP), and alkali metal salts thereof; addition reaction products of 4-methyl-γ-oxo-benzenebutanoic acid and N-ethylmorpholine; intercalation compounds obtained by intercalating monoalkylamines, polyamines, quaternary ammonium ions, etc. into layered phosphates such as aluminum dihydrogen tripolyphosphate; and hydrazine derivatives such as hydrazide compounds, semicarbazide compounds, and hydrazone compounds.

[0102] Among these, nitrites (e.g., metal salts such as sodium, potassium, calcium, etc., and ammonium salts) and benzoates (e.g., metal salts such as sodium, potassium, calcium, etc., and ammonium salts) are preferred because they have excellent flash rust resistance and are inexpensive, and nitrites are more preferred, with sodium nitrite being particularly preferred, because a composition that exhibits high flash rust resistance can be easily obtained even with a small amount used.

[0103] When the present composition contains a flash rust inhibitor, the content thereof is preferably 0.01 to 2 mass%, more preferably 0.03 to 1 mass%, relative to 100 mass% of the nonvolatile content of the present composition, in order to easily obtain a composition with excellent flash rust resistance, etc.

[0104] [Antifoaming agent] The present composition preferably contains an antifoaming agent, since this can suppress the generation of bubbles during the production or application of the composition, or can break any bubbles that have generated in the present composition, thereby making it possible to easily form a coating film having the desired physical properties. The defoaming agent may be a commercially available product, and examples of such commercially available products include "BYK-320," "BYK-066N," and "BYK-1790" (all manufactured by BYK Japan K.K.) and "TEGO Airex 902W" (manufactured by Evonik).

[0105] When the present composition contains an antifoaming agent, the content thereof is preferably 0.005 to 1 mass %, more preferably 0.01 to 0.5 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoints that the generation of foam can be sufficiently suppressed and a coating film with the desired physical properties can be easily formed.

[0106] [Film-forming agent] Since the present composition contains water, which may cause the composition to freeze in winter, and also from the viewpoint of improving film-forming properties at low temperatures and the finished appearance of the resulting coating film, it is preferable that the composition contain a film-forming aid.

[0107] The film-forming aid may be one that is commonly used in aqueous coating compositions, and examples thereof include linear or branched aliphatic alcohols having 5 to 10 carbon atoms; alcohols having an aromatic ring; monoethers such as (poly)ethylene glycol or (poly)propylene glycol; (poly)ethylene glycol ether esters; and (poly)propylene glycol ether esters.

[0108] When the present composition contains a film-forming aid, the content thereof is preferably 1 to 10 mass %, more preferably 3 to 8 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoint of being able to easily form a coating film that has excellent film-forming properties at low temperatures and excellent appearance.

[0109] [Plasticizer] When the present composition is used as a primer coating for non-ferrous metal substrates or stainless steel substrates, it is preferred that it contain a plasticizer. As the plasticizer, any known plasticizer can be used, and examples thereof include glycol ether polymers, phthalates, trimellitates, aliphatic dibasic acid esters, phosphates, ricinoleates, polyesters, acetates, and sulfonamides.

[0110] When the present composition contains a plasticizer, the content thereof is preferably 0.1 to 3.0 mass %, more preferably 0.5 to 2.5 mass %, relative to 100 mass % of the nonvolatile content of the present composition, from the viewpoint of easily forming a coating film that has excellent adhesion to non-ferrous metals and stainless steel surfaces.

[0111] [Thickener] The present composition preferably contains a thickener, since this can prevent sagging during application. As the thickener, any conventionally known thickener can be used, and examples thereof include polysaccharide-based, alkali-thickening type, polyurethane association type, polyether association type, polyolefin-based, and cellulose-based thickeners.

[0112] When the present composition contains a thickener, the content thereof is preferably 0.1 to 0.4 mass%, more preferably 0.15 to 0.35 mass%, relative to 100 mass% of the nonvolatile content of the present composition, in order to sufficiently suppress sagging during application.

[0113] [Organic solvents] When the first agent contains water, any amount of organic solvent miscible with water may be used to prevent freezing in winter and to obtain a composition with superior coating workability. As the organic solvent, one type may be used, or two or more types may be used.

[0114] Examples of such organic solvents include alcohol-based solvents having 1 to 3 carbon atoms, such as isopropyl alcohol and ethylene glycol, and glycol ether-based solvents, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0115] The organic solvent is preferably used in an amount such that the VOC content in the composition falls within the above range.

[0116] <Second agent> The second part of the composition is not particularly limited as long as it contains a non-aqueous epoxy resin (C) having an epoxy equivalent of 270 or less, and may consist essentially of the resin (C) alone, or may contain components other than the resin (C) as long as the effects of the present invention are not impaired. Components other than the resin (C) include the same components as those described in the section for the first part above, as well as zinc dust (F). One or more of the other components may be used.

[0117] Furthermore, for the same reasons as those mentioned above, it is preferable that the second agent contains a film-forming aid, and examples of such film-forming aids include the same film-forming aids as those listed in the section for the first agent.

[0118] <Epoxy resin (C)> Examples of the resin (C) include a polymer or oligomer containing two or more epoxy groups in the molecule, and a polymer or oligomer produced by a ring-opening reaction of the epoxy groups. The resin (C) may be used alone or in combination of two or more.

[0119] Resin (C) is preferably a non-aqueous epoxy resin, i.e., an epoxy resin that cannot be dissolved or dispersed in water, because it can easily produce a composition that has excellent drying properties at low temperatures and can easily form a coating film that has excellent water resistance and corrosion resistance. Specific examples of non-aqueous epoxy resins include epoxy resins whose light transmittance measured by the method described in the examples below is preferably 1% or more, and more preferably 10% or more.

[0120] The epoxy equivalent of resin (C) (epoxy equivalent of the non-volatile content of resin (C)) is preferably 100 to 270, more preferably 100 to 200, from the viewpoint that a coating composition with a low VOC content can be easily obtained. Epoxy resins having an epoxy equivalent in this range include liquid and semi-solid epoxy resins. When the epoxy equivalent is within the above range, a coating composition with a low VOC content can be easily obtained, and the effects of the present invention can be more effectively exhibited, which is preferable. When the epoxy equivalent is more than 270, it tends to be difficult to easily obtain a coating composition with a low VOC content. The epoxy equivalent weight is calculated based on the non-volatile content of the resin in accordance with JIS K 7236:2001.

[0121] In addition, an epoxy resin having an epoxy equivalent of more than 270 can be used in combination with this composition, provided that the effects of the present invention are not impaired. The ratio of epoxy resin having an epoxy equivalent of more than 270 to 100 parts by mass of resin (C) is preferably 50 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less, from the viewpoint of being able to easily obtain a coating composition with a low VOC content.

[0122] Examples of the resin (C) include bisphenol-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, novolac-type epoxy resins, cresol-type epoxy resins, dimer acid-modified epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, and epoxidized oil-based epoxy resins.

[0123] Among these, bisphenol-type epoxy resins and novolac-type epoxy resins are preferred, with bisphenol A-type or bisphenol F-type epoxy resins being more preferred, and bisphenol A-type epoxy resins being particularly preferred, because they can easily form anticorrosive coating films that have excellent adhesion to substrates.

[0124] Examples of resin (C) include epichlorohydrin-bisphenol A epoxy resins (bisphenol A diglycidyl ether type); epichlorohydrin-bisphenol AD ​​epoxy resins; epichlorohydrin-bisphenol F epoxy resins; epoxy novolac resins; alicyclic epoxy resins obtained from 3,4-epoxyphenoxy-3',4'-epoxyphenylcarboxymethane and the like; brominated epoxy resins in which at least one hydrogen atom bonded to the benzene ring in an epichlorohydrin-bisphenol A epoxy resin is substituted with a bromine atom; aliphatic epoxy resins obtained from epichlorohydrin and an aliphatic dihydric alcohol; and polyfunctional epoxy resins obtained from epichlorohydrin and tri(hydroxyphenyl)methane.

[0125] Examples of the bisphenol A type epoxy resin include condensation polymers of bisphenol A type diglycidyl ethers such as bisphenol A diglycidyl ether, bisphenol A (poly)propylene oxide diglycidyl ether, bisphenol A (poly)ethylene oxide diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and hydrogenated bisphenol A (poly)propylene oxide diglycidyl ether.

[0126] The resin (C) may be a compound synthesized by a conventionally known method, or a commercially available product. Commercially available products that are liquid at room temperature (15 to 25°C, the same applies hereinafter) include "EPOKUKDO YD-128" (manufactured by KUKDO Co., Ltd., bisphenol A diglycidyl ether, non-volatile content 100%, epoxy equivalent weight 184 to 190, viscosity 11,500 to 13,500 mPa·s / 25°C), "E-028" (manufactured by Ohtake Meishin Chemical Co., Ltd., bisphenol A diglycidyl ether, non-volatile content 100%, epoxy equivalent weight 180 to 190, viscosity 12,000 to 15,000 mPa·s / 25°C), and "j Examples include "ER-807" (manufactured by Mitsubishi Chemical Corporation, bisphenol F diglycidyl ether, epoxy equivalent 160 to 175, viscosity 3,000 to 4,500 mPa·s / 25°C), and "E-028-90X" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A diglycidyl ether (828 type epoxy resin solution, non-volatile content 90%), epoxy equivalent of non-volatile content approximately 190). Examples of epoxy resins that are semi-solid at room temperature include "jER-834" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent weight 230 to 270, non-volatile content 100%), "E-834-85X" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type semi-solid epoxy resin (834 type epoxy resin solution, non-volatile content 85%), epoxy equivalent weight of non-volatile content approximately 255), and novolac type epoxy resins such as "DEN 425" (manufactured by Dow Chemical Co., Ltd., epoxy equivalent weight 169 to 175, non-volatile content 100%), "DEN 431" (manufactured by Dow Chemical Co., Ltd., epoxy equivalent weight 172 to 179, non-volatile content 100%) and "DEN 438" (manufactured by Dow Chemical Co., Ltd., epoxy equivalent weight 176 to 181, non-volatile content 100%).

[0127] The content of the resin (C) relative to 100% by mass of the nonvolatile content of the present composition is preferably 0.5 to 25% by mass, and more preferably 1 to 20% by mass. The content of the resin (C) in the second part is preferably 1 to 95% by mass, more preferably 1.5 to 90% by mass. When the content of the resin (C) is within the above range, it is possible to easily obtain an anticorrosive coating film that is more excellent in anticorrosion properties and adhesion to the substrate.

[0128] For example, when the composition is used as an undercoat paint, intermediate coat paint or topcoat paint, the content of the nonvolatile content of resin (C) in the composition is preferably 1 to 25 mass %, more preferably 1.5 to 20 mass %, based on 100 mass % of the nonvolatile content of the composition, for the same reasons as above.Furthermore, when the composition is used as a zinc primer, the content of the nonvolatile content of resin (C) in the composition is preferably 0.5 to 10 mass %, based on 100 mass % of the nonvolatile content of the composition, for the same reasons as above.

[0129] [Zinc powder (F)] For example, when the present composition is used as a zinc primer, zinc dust (F) is added to the present composition. Examples of the zinc powder (F) include powder of metallic zinc, or powder of an alloy mainly composed of zinc (zinc content of 90 mass% or more of the total) (e.g., an alloy of zinc and at least one selected from aluminum, magnesium, and tin, preferably a zinc-aluminum alloy or a zinc-tin alloy). As the zinc powder (F), one type may be used, or two or more types may be used.

[0130] The shape of the zinc dust (F) is not particularly limited, but particulate zinc dust having a median diameter (D50) of preferably 2 to 15 μm, more preferably 2 to 7 μm, is desirable, as it allows for the easy formation of a coating film with better corrosion resistance. The D50 can be measured using a laser scattering diffraction particle size distribution analyzer, for example, "SALD 2200" (manufactured by Shimadzu Corporation).

[0131] For example, when the present composition is used as a zinc primer, the content of zinc dust (F) relative to 100% by mass of the non-volatile content of the present composition is preferably 55 to 90% by mass, more preferably 60 to 85% by mass, from the viewpoint of being able to easily form a coating film with better corrosion resistance and water resistance, etc.

[0132] <Method for preparing anticorrosion coating composition> The first and second agents can be prepared by mixing (kneading) the components to be blended into these agents. During this mixing (kneading), the components may be added and mixed all at once, or may be added and mixed in multiple batches. The present composition can be prepared by mixing (kneading) the first agent, the second agent, and other agents (for example, a third agent) that are used as needed. The mixing (kneading) can be carried out using a conventionally known device such as a mixer, disperser, or stirrer, and examples of such devices include a disperser, a mixing / dispersing mill, a mortar mixer, a roll, a paint shaker, and a homogenizer. The mixing (kneading) may be carried out while heating or cooling depending on the season, environment, etc.

[0133] <Coating film, coated substrate> The coating film according to the present invention (hereinafter also referred to as "the present coating film") is formed using the present composition, and the substrate with the coating film according to the present invention (hereinafter also referred to as "the substrate with the present coating film") is a laminate having the present coating film and a substrate.

[0134] The material of the substrate is not particularly limited, and examples thereof include steel (iron, steel, ferroalloy, carbon steel, mild steel, alloy steel, etc.), non-ferrous metals (zinc, aluminum, copper, brass, zinc plating, zinc thermal spraying, etc.), and stainless steel (SUS304, SUS410, etc.). Furthermore, when mild steel (SS400, etc.) is used as the substrate, it is desirable to adjust the surface of the substrate (e.g., adjust the arithmetic mean roughness (Ra) to about 30 to 75 μm) by polishing the surface of the substrate by grit blasting, etc., as necessary. The substrate may be a substrate that has been subjected to pretreatment such as cleaning or blasting to remove rust, dirt, paint (old paint film), and the like adhering to the substrate.

[0135] The substrate is not particularly limited, and can be used without limitation on substrates that require corrosion resistance. However, in terms of the effects of using the present composition being more pronounced, preferred examples include (steel) structures such as ships, marine structures, plants, bridges, tanks, and containers.

[0136] The dry film thickness of the coating is not particularly limited, but is usually 10 to 100 μm, preferably 15 to 80 μm, and more preferably 20 to 60 μm, in order to obtain a coating having sufficient anticorrosion properties.

[0137] The substrate with the coating film of the present invention is a laminate comprising the coating film of the present invention and a substrate, and may have an undercoat coating film (primer coating film) intended to improve adhesion to the substrate and corrosion resistance, an intermediate coating film intended to improve corrosion resistance, and a topcoat coating film that is excellent in weather resistance, aesthetics, etc. Specifically, when the present composition is used as a zinc primer, an intermediate coating film or a topcoat coating film may be formed on the present coating film; when the present composition is used as an intermediate coating, a primer coating film may be formed between the present coating film and the substrate, or a topcoat coating film may be formed on the present coating film; when the present composition is used as a topcoat paint (internal topcoat paint), a primer coating film or an intermediate coating film may be formed between the present coating film and the substrate; and when the present composition is used as an intermediate coating film for a non-ferrous metal substrate or a stainless steel substrate, a primer coating film or a topcoat coating film may be formed on the present coating film. Examples of the undercoat coating film include coating films formed from various primer compositions such as epoxy resin-based ones. Examples of the intermediate coating film include coating films formed from various intermediate coating compositions such as (meth)acrylic resin-based, epoxy resin-based, and urethane resin-based ones. Examples of the topcoat coating film include coating films formed from various topcoat coating compositions such as (meth)acrylic resin-based, (meth)acrylic silicone resin-based, urethane resin-based, silicone resin-based, and fluororesin-based ones. Furthermore, the composition of the present composition may be changed to form the undercoat coating film, intermediate coating film, and topcoat coating film using the present composition.

[0138] <Manufacturing method of substrate with coating film> The method for producing a substrate with a coating film according to the present invention (hereinafter also referred to as "the method") includes the following steps [1] and [2]. Step [1]: Applying the composition to a substrate Step [2]: A step of drying the composition applied to the substrate to form a coating film.

[0139] <Process [1]> The coating method in the step [1] is not particularly limited, and examples thereof include conventionally known methods such as spray coating such as airless spray coating and air spray coating, brush coating, roller coating, etc. Among these, spray coating is preferred because it allows for easy coating of large-area substrates such as the structure. In such coating, it is preferable to coat the resulting coating so that the dry film thickness falls within the above range.

[0140] The spray coating conditions may be adjusted as appropriate depending on the desired dry film thickness. For example, in the case of airless spray coating, it is preferable that the primary (air) pressure is about 0.3 to 0.6 MPa, the secondary (paint) pressure is about 10 to 15 MPa, and the gun movement speed is about 50 to 120 cm / sec.

[0141] When applying the composition, the viscosity of the coating composition may be adjusted as desired, preferably using water as a diluent for adjusting the viscosity. In this case, it is preferable to use a diluent so that the paint viscosity is suitable for each coating method. For example, in the case of airless spray coating, the amount of diluent used per 100 parts by mass of the composition is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass.

[0142] The viscosity of the composition suitable for spray coating (diluted as necessary) is preferably 500 to 5,000 mPa·s, more preferably 1,000 to 3,000 mPa·s, measured at 23°C using a B-type viscometer (manufactured by Rion Co., Ltd., Model VT-06) as the measuring instrument.

[0143] <Process [2]> The drying conditions in step [2] are not particularly limited and may be set appropriately depending on the coating film formation method, the type of substrate, the intended use, the coating environment, etc., but the drying temperature is usually 5 to 35° C. when drying at room temperature, and usually 30 to 90° C., more preferably 40 to 80° C. when forced drying is performed using a hot air dryer or the like. The present composition can be dried and cured even by drying at room temperature. The drying time varies depending on the drying method of the coating film, and when dried at room temperature, it may take about 1 to 7 days, as with conventional paints, but with the present composition, it can be dried and cured preferably in 1.5 to 6 hours, more preferably 1.5 to 3 hours. When forced drying is used, it may take about 5 to 60 minutes, as with conventional paints, but with the present composition, it can be dried and cured preferably in 5 to 30 minutes, more preferably 10 to 20 minutes. [Example]

[0144] The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0145] [Example 1] A mill base was prepared by adding 24 parts by weight of ion-exchanged water, 1 part by weight of Dispersant 1, 0.1 parts by weight of flash rust inhibitor, 0.1 parts by weight of antifoaming agent, 4 parts by weight of color pigment, 34 parts by weight of extender pigment, and 0.2 parts by weight of thixotropic agent to a container and dispersing the mixture to a particle size of 40 μm or less using a high-speed disperser. 32 parts by weight of Acrylic Resin 1, 2.6 parts by weight of Curing Agent A-1, 1.2 parts by weight of film-forming agent, 0.3 parts by weight of antifoaming agent, and 0.5 parts by weight of thickener to the resulting mill base, and then mixing using a high-speed disperser to prepare the first part. 70 parts by mass of epoxy resin 1 and 30 parts by mass of film-forming aid were added to a container and then mixed with a high-speed disper to prepare a second part. Thereafter, 95 parts by mass of the first part obtained as described above and 5 parts by mass of the second part were mixed in a high-speed disper until homogeneous to prepare a coating composition.

[0146] [Examples 2 to 17 and Comparative Examples 1 to 9] Coating compositions were prepared in the same manner as in Example 1, except that the raw materials shown in Tables 1 to 5 were used in the amounts (parts by mass) shown in the tables and mixed in the mixing ratios shown in Tables 1 to 5. Details of the raw materials in Tables 1 to 5 are shown in Table 6.

[0147] The coating compositions obtained in Examples 1 to 8 can be suitably used as intermediate coatings, the coating composition obtained in Example 9 can be suitably used as a topcoat coating for the inside of tanks, containers, etc., the coating composition obtained in Example 10 can be suitably used as a zinc primer, and the coating compositions obtained in Examples 11 to 17 can be suitably used as an undercoat coating for non-ferrous metal substrates or stainless steel substrates.

[0148] <Drying> According to ASTM D5895, each of the coating compositions of the Examples and Comparative Examples was applied using an applicator with a gap of 0.2 mm, and after application and drying at 23°C or 5°C, the time until the coating surface reached a semi-cured state (tack-free) and the time until it reached a completely cured state (dry-hard) were measured. The results are shown in Tables 1 to 5.

[0149] [Test specimen preparation method 1] The viscosity of each coating composition of Examples 1 to 8 and Comparative Examples 1 to 9 was adjusted with ion-exchanged water so that the viscosity at 23°C of each coating composition was 1,000 mPa·s, as measured using a Brookfield viscometer (manufactured by Rion Co., Ltd., Model VT-06). An aqueous zinc primer (EKOMATE ZINC M, manufactured by Chugoku Toryo Co., Ltd.) was sprayed onto a blast-treated steel plate (SS400, dimensions: 150 mm x 70 mm x 1.6 mm (thickness)) using an air spray to give an average dry film thickness of 30 μm. The primer was then dried at room temperature for 5 minutes and then hot-air dried at 50°C for 15 minutes to form a primer coating. Next, each of the paint compositions after viscosity adjustment was applied to the undercoat coating film by air spray so that the average dry film thickness was 40 μm, and the coating was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 15 minutes to form an intermediate coating film. Subsequently, an acrylic resin-based water-based topcoat paint ("EKOMATE FINISH", manufactured by Chugoku Toryo Co., Ltd.) was applied to the intermediate coating film using an air spray so that the average dry film thickness was 40 μm, and the coating was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 30 minutes to form a topcoat coating film. After forming the topcoat coating, it was dried for 7 days in an environment of 23°C and 50% relative humidity to prepare test specimens (substrates with coating prepared through a forced drying process) to be used in the water resistance and corrosion resistance tests described below.

[0150] [Test specimen preparation method 2] The viscosity of each coating composition of Examples 1 to 8 and Comparative Examples 1 to 9 was adjusted with ion-exchanged water so that the viscosity at 23°C of each coating composition was 1,000 mPa·s, as measured using a Brookfield viscometer (manufactured by Rion Co., Ltd., Model VT-06). A water-based zinc primer (EKOMATE ZINC M, manufactured by Chugoku Toryo Co., Ltd.) was sprayed onto a blasted steel plate (SS400, dimensions: 150 mm x 70 mm x 1.6 mm (thickness)) using an air spray to give an average dry film thickness of 30 μm, and then dried overnight at 5°C to form a primer coating. Next, each of the paint compositions after viscosity adjustment was applied to the undercoat coating film by air spray so that the average dry film thickness was 40 μm, and the coating was dried overnight in a 5°C environment to form an intermediate coating film. Subsequently, an acrylic resin-based water-based topcoat paint ("EKOMATE FINISH", manufactured by Chugoku Toryo Co., Ltd.) was applied to the intermediate coating film using an air spray so that the average dry film thickness was 40 μm, and the paint was dried overnight in a 5°C environment to form a topcoat coating film. After forming the topcoat coating film, it was dried overnight in a 5°C environment to prepare a test specimen (a substrate with a coating film prepared through a 5°C drying process) to be used in the corrosion resistance test described below.

[0151] [Test specimen preparation method 3] The viscosity of the coating composition of Example 9 was adjusted with ion-exchanged water so that the viscosity at 23°C of the composition measured using the Brookfield viscometer was 1,000 mPa·s. The aqueous zinc primer was applied by air spray to a blast-treated steel plate (SS400, dimensions: 150 mm × 70 mm × 1.6 mm (thickness)) so that the average dry film thickness was 30 μm, and the resulting film was dried at room temperature for 5 minutes, followed by hot air drying at 50°C for 15 minutes to form a primer coating film. Next, the viscosity-adjusted coating composition was applied by air spray onto the formed undercoat coating film so that the average dry film thickness was 50 μm, and the coating was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 30 minutes to form a topcoat coating film. After forming the topcoat coating, it was dried for 7 days in an environment of 23°C and 50% relative humidity to prepare test specimens (substrates with coating) to be used in various coating performance evaluation tests described below.

[0152] [Test specimen preparation method 4] The viscosity of the coating composition of Example 10 was adjusted with ion-exchanged water so that the viscosity at 23°C of the composition measured using the Brookfield viscometer was 1,000 mPa·s. The viscosity-adjusted coating composition was applied by air spray to a blast-treated steel plate (SS400, dimensions: 150 mm × 70 mm × 1.6 mm (thickness)) so that the average dry film thickness was 30 μm, and the coating was dried at room temperature for 5 minutes and then hot-air dried at 50°C for 15 minutes to form a primer coating film. An acrylic resin-based water-based intermediate coating ("EKOMATE 100 PRIMER", manufactured by Chugoku Toryo Co., Ltd.) was applied to the primer coating film using an air spray so that the average dry film thickness was 40 μm, and the film was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 15 minutes to form an intermediate coating film. The acrylic resin-based water-based topcoat paint was then applied to the intermediate coating film by air spraying so that the average dry film thickness was 40 μm, and the coating was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 30 minutes to form a topcoat coating film. After forming the topcoat coating, it was dried for 7 days in an environment of 23°C and 50% relative humidity to prepare test specimens (substrates with coating) to be used in various coating performance evaluation tests described below.

[0153] [Test specimen preparation method 5] The viscosity of the coating compositions of Examples 11 to 17 was adjusted with ion-exchanged water so that the viscosity at 23° C. of the compositions was 1,000 mPa·s, as measured using the Brookfield viscometer. The viscosity-adjusted coating composition was applied by air spray to a stainless steel plate (SUS410, dimensions 150 mm × 70 mm × 1.6 mm (thickness)) so that the average dry film thickness was 40 μm, and the coating was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 15 minutes to form a primer coating film. The acrylic resin-based water-based topcoat paint was applied to the undercoat film by air spraying so that the average dry film thickness was 40 μm, and the film was dried at room temperature for 10 minutes, followed by hot air drying at 50°C for 30 minutes to form a topcoat film. After forming the topcoat coating, it was dried for 7 days in an environment of 23°C and 50% relative humidity to prepare test specimens (substrates with coating) to be used in various coating performance evaluation tests described below.

[0154] <Water resistance> Based on JIS K 5600-6-2:2016 for liquid resistance (water immersion method), a water immersion test was conducted on the test specimens prepared as described above by immersing them in water at 23°C for 96 hours, and the water resistance was evaluated according to the following evaluation criteria. The results are shown in Tables 1 to 5. (Evaluation criteria) ○: No blistering occurred on the coating film after the water resistance test △: Blisters occurred on the coating film after the water resistance test, and the size of the blister was 2 and the amount (density) was 3 or less as specified in JIS K 5600-8-2:2008. ×: Blisters occurred on the coating film after the water resistance test, and the size of the blister was 2 and the amount (density) was 4 or more, or the size of the blister was 3 or more, as specified in JIS K 5600-8-2:2008.

[0155] <Corrosion resistance> Scratches (scribes) were made on the test specimen prepared as described above, from a point 5 cm from the bottom end of the long side and 1 cm from the left end of the short side, to a point 1 cm from the bottom end of the long side and 1 cm from the right end of the short side, to a depth sufficient to expose the steel plate or stainless steel plate.Similarly, scratches (scribes) were made on the test specimen, from a point 5 cm from the bottom end of the long side and 1 cm from the right end of the short side, to a point 1 cm from the bottom end of the long side and 1 cm from the left end of the short side, to a depth sufficient to expose the steel plate or stainless steel plate. The test specimens were placed with the scribe side facing downwards in a salt spray tester under salt spray conditions of 5 wt% salt water, 35°C temperature, and 98% relative humidity in accordance with JIS K 5600-7-1:1999, and held for 24 hours to undergo a salt spray test. The corrosion resistance was evaluated according to the following evaluation criteria. The results are shown in Tables 1 to 5. (Evaluation criteria) ○: No rust or blistering occurred on the coating film after the salt spray test. △: Rust or blistering occurred on the coating film after the salt spray test, and the rust grade specified in JIS K 5600-8-3:2008 was Ri1 or less (Ri1, Ri0), or the blister size specified in JIS K 5600-8-2:2008 was 2 and the amount (density) was 3 or less. ×: Rust or blisters have occurred on the coating film after the salt spray test, and the rust grade specified in JIS K 5600-8-3:2008 is Ri2 or higher (Ri2, Ri3...), or the blister size specified in JIS K 5600-8-2:2008 is 2 and the quantity (density) is 4 or higher, or the blister size is 3 or higher.

[0156] <Pot life> 1000 g of each coating composition of the Examples and Comparative Examples was weighed out and placed in a container with an inner diameter of 11 cm and a height of 12.5 cm, and kept in a thermostatic chamber at 35°C. The time until precipitation or aggregation of the composition occurred was measured. The results are shown in Tables 1 to 5.

[0157] <Secondary adhesion> [Cross-cut adhesion test] After the corrosion resistance test, the test specimens were washed with water and then dried for one day in an environment at 23°C and 50% humidity. A cross-cut adhesion test (cross-cut method) was then conducted on the areas of the test specimens that had been sprayed with salt water but had no scribe lines, in accordance with JIS K 5600-5-6:1999, with 25 2mm x 2mm squares. The adhesion was evaluated according to the following criteria, expressed as the percentage of the area of ​​the coating film that had peeled off from the stainless steel plate relative to the 100% coating area occupied by the 25 squares. The results are shown in Table 5. (Evaluation criteria) ○: The area of ​​peeled coating is 15% or less ×: The area of ​​peeled coating is greater than 15%

[0158] [Creep width measurement] After the corrosion resistance test, the test specimens were washed with water and then dried for one day at a temperature of 23°C and humidity of 50%. The creep width (the distance between the scribed area and the point where the coating film and the stainless steel plate had peeled off, which was the farthest from the scribed area) was measured in the test specimen's evaluation area. Note that the "evaluation area" here refers to the area excluding a 1 cm area from the edge of the test specimen. The results are shown in Table 5.

[0159] [Table 1]

[0160] [Table 2]

[0161] [Table 3]

[0162] [Table 4]

[0163] [Table 5]

[0164] [Table 6]

[0165] In Example 1, epoxy resin 1 was used. However, similar results were obtained when an #834 type epoxy resin such as "jER-834" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent weight 230-270, non-volatile content 100%) or "E-834-85X" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type semi-solid epoxy resin (834 type epoxy resin solution, non-volatile content 85%), epoxy equivalent weight of non-volatile content approximately 255) was used instead of epoxy resin 1. However, when the #834 type epoxy resin is used, the VOC content increases by about 10 g / L compared to Example 1 above.

[0166] <Properties of epoxy resin> The properties of the epoxy resins used in the above examples and comparative examples were measured as follows. 0.1 g of the epoxy resin (as is) used in the examples and comparative examples was added to a mixed solution of 90 g of pure water and 10 g of butyl carbitol in a sample bottle, and the sample bottle was shaken well to obtain a measurement solution. Note that 0.1 g of epoxy resin (as is) means that when 0.1 g of epoxy resin with a % non-volatile content is used as the epoxy resin, the epoxy resin (as is) is 0.1 g, not 0.1 × a / 100 g.

[0167] After performing a baseline measurement using the mixed solution, the transmittance of the obtained measurement solution was measured under the following measurement conditions. The mixed solution was used as a reference. The transmittance of light with a wavelength of 600 nm is shown in Table 7 below. (Measurement conditions) Equipment: SolidSpec-3700 (Shimadzu Corporation) Measurement wavelength range: 200-800nm Scan speed: 300nm / min Sampling pitch: 0.5nm Slit width: 5nm Light source: Deuterium lamp (200-310nm) and halogen lamp (310-1400nm) nm) Optical path length (cell thickness) 1cm

[0168] [Table 7]

[0169] It should be noted that, like Epoxy Resin 2, Epoxy Resin 3 is an emulsion, and therefore it is thought that the results will be similar to those of Epoxy Resin 2.

Claims

1. a first agent containing an epoxy resin curing agent (A), a (meth)acrylic resin (B), and water (D); and a second agent containing a non-aqueous epoxy resin (C) having an epoxy equivalent of 270 or less, the curing agent (A) comprises one or more selected from the group consisting of aqueous amine curing agents (A1) and aqueous amine-modified epoxy resins (A2); the active hydrogen equivalent per nonvolatile content of the aqueous amine curing agent (A1) is 30 to 500; Anticorrosive coating composition.

2. The corrosion-protective coating composition according to claim 1, wherein the acid value of the non-volatile content of the (meth)acrylic resin (B) is 10 to 70 mg KOH / g.

3. The corrosion-protective coating composition according to claim 1 or 2, wherein the weight average molecular weight (Mw) of the non-volatile content of the (meth)acrylic resin (B) measured by gel permeation chromatography (GPC) is 50,000 to 200,000.

4. 4. The corrosion-protective coating composition according to claim 1, wherein the content of non-volatile matter in the resin (B) is 20 to 95 mass% relative to 100 mass% of the total of the non-volatile matters in the curing agent (A), resin (B), and resin (C).

5. The anticorrosion coating composition according to any one of claims 1 to 4, wherein the content of volatile organic compounds (VOCs) is 200 g / L or less.

6. A coating film formed from the anticorrosion coating composition according to any one of claims 1 to 5.

7. A coated substrate comprising a substrate and the coating film according to claim 6.

8. A method for producing a substrate with a coating film, comprising the following steps [1] and [2]: [1] A step of coating a substrate with the anticorrosive coating composition according to any one of claims 1 to 5. [2] A step of drying the anticorrosive coating composition applied to the substrate to form a coating film

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