Aqueous coating composition kit, aqueous coating composition, coating film, coated article, and method for producing coated article

Abstract

An aqueous coating composition kit having a first agent containing a nonaqueous epoxy compound (A1) and a silicate compound (B), and a second agent containing an amine compound (C) and water.

Description

Water-based paint composition kit, water-based paint composition, coating film, painted product, and method for manufacturing the painted product.

[0001] This disclosure relates to a water-based paint composition kit, a water-based paint composition, a coating film, a coated product, and a method for manufacturing a coated product.

[0002] Various industrial structures, such as bridges, tanks, plants, and (transport) containers, are typically coated with paint to prevent corrosion. In recent years, there has been a growing demand for a shift from solvent-based paints to water-based paints (water-based paint compositions) as the composition for forming these paint films, from the perspective of environmental protection and workplace safety.

[0003] As the above-mentioned water-based paint compositions, paint compositions such as epoxy-amine curing systems, which react an epoxy resin with an amine curing agent, are known. For example, as an epoxy-amine curing system, Patent Document 1 discloses a paint composition containing an epoxy resin, an amine curing agent, a silane coupling agent, water, and a pigment. Patent Document 2 also discloses a kit for a corrosion-preventive paint composition containing a first agent containing a non-aqueous epoxy compound, and a second agent containing an aqueous diluent component containing an amine compound and a non-aqueous component containing an amine compound.

[0004] International Publication No. 2017 / 159740, Japanese Patent Publication No. 2022-154829

[0005] Conventional water-based paint compositions, such as epoxy-amine curing systems, contain a certain amount of water to ensure workability. However, the rate of water evaporation is affected by the curing environment, which in turn affects the drying properties of the paint film. In particular, it has been found that under high humidity or low temperature conditions (e.g., 70% ambient humidity and 5°C ambient temperature), the paint film can become sticky (tack occurs). This is because, under these curing conditions, the rate of water evaporation from the paint film decreases drastically, making it easier for non-aqueous components such as non-aqueous epoxy resins and non-aqueous amine compounds to rise to the surface of the paint film. Once tack occurs, it can persist for several days, delaying the process on site. In addition to tack, as mentioned above, the non-aqueous components rise to the surface of the paint film, resulting in an uneven coating. This can lead to delayed curing, and when walking on the dried paint film, it can cause damage to the surface, such as shoe prints or twist marks, or even peeling of the paint film. The condition of the paint film surface after drying affects walkability, indicating that there is room for improvement from the perspective of walkability.

[0006] The present disclosure aims to provide a water-based paint composition kit that exhibits excellent curing properties even under high humidity or low temperatures (e.g., 70% humidity or 5°C), is less prone to tack formation, and can form a coating film with excellent walkability.

[0007] One embodiment of the aqueous coating composition kit of the present disclosure comprises a first agent containing a non-aqueous epoxy compound (A1) and a silicate compound (B), and a second agent containing an amine compound (C) and water.

[0008] According to this disclosure, it is possible to obtain a water-based paint composition kit that exhibits excellent curing properties even under high humidity or low temperature conditions (e.g., 70% humidity or 5°C), is less prone to tack formation, and can form a coating film with excellent walkability.

[0009] Figure 1 is a diagram illustrating the method for evaluating drying and curing properties in the examples.

[0010] ≪Water-based paint composition and kit thereof≫ One embodiment of the water-based paint composition kit of the present disclosure (hereinafter also referred to as "Kit 1") comprises a first agent and a second agent, wherein the first agent contains a non-aqueous epoxy compound (A1) and a silicate compound (B), and the second agent contains an amine compound (C) and water. Another embodiment of the water-based paint composition kit of the present disclosure (hereinafter also referred to as "Kit 2") comprises a first agent, a second agent and a third agent, wherein the first agent contains an aqueous epoxy compound (A2) and water, the second agent contains an amine compound (C), and the third agent contains a silicate compound (B). Hereinafter, Kit 1 and Kit 2 are collectively referred to as "the Kit."

[0011] The water-based paint composition obtained by mixing each agent of Kit 1 is also referred to as "Composition 1." The water-based paint composition obtained by mixing each agent of Kit 2 is also referred to as "Composition 2." Composition 1 and Composition 2 are collectively referred to as "the Composition." In this disclosure, "water-based paint composition" refers to a paint composition in which components such as epoxy compounds, amine compounds, and silicate compounds are dispersed and / or dissolved in water or a water-containing medium (hereinafter also referred to as "aqueous medium").

[0012] The aqueous medium is not particularly limited as long as it contains water, but the water content in the aqueous medium is preferably 50 to 100% by mass, more preferably 60 to 100% by mass. The aqueous medium may also contain a medium other than water that has a boiling point of less than 180°C at atmospheric pressure. Examples of such a medium other than water that has a boiling point of less than 180°C at atmospheric pressure include acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol monopropyl ether. These may be one or two or more.

[0013] Kit 1 may be, for example, a two-dosage kit, and may contain a further agent in addition to the first and second agents. Kit 2 may be, for example, a three-dosage kit, and may contain a further agent in addition to the first, second, and third agents.

[0014] The first, second, and third agents, etc., are usually stored, kept, and transported in separate containers, and mixed together immediately before use.

[0015] [Non-aqueous epoxy compound (A1)] The first component of this kit 1 contains a non-aqueous epoxy compound (A1). The non-aqueous epoxy compound (A1) may be one type or two or more types.

[0016] In the context of non-aqueous epoxy compounds (A1), "non-aqueous" means a state in which the epoxy compound is not freely miscible with water, and is substantially insoluble in water; it can also be called a non-aqueous dispersion type. Specifically, if the epoxy compound and water are mixed at 23°C so that the epoxy compound concentration is 3% by mass, the mixture is thoroughly stirred, and the resulting mixture is left to stand at 23°C for 1 hour, and the resulting mixture is not homogeneous, and 90% or more by mass of the epoxy compound mixed with water is separated, precipitated, or suspended, then the epoxy compound is considered a non-aqueous epoxy compound (A1). Preferably, the above epoxy compound has two or more epoxy groups in one molecule.

[0017] Furthermore, in some cases, it may be impossible to determine whether a non-aqueous epoxy compound (A1) was a non-aqueous epoxy compound after it has been mixed with other components that may be included in the first agent. However, even in such cases, if a non-aqueous epoxy compound is used as a raw material when preparing the first agent, etc., the first agent, etc. is said to contain the non-aqueous epoxy compound (A1). The same applies to aqueous epoxy compound (A2).

[0018] The non-aqueous epoxy compound (A1) is preferably a liquid epoxy compound that is liquid at room temperature (e.g., 15-25°C). Such a liquid epoxy compound is preferable because it is easy to uniformly disperse it in the first agent even if the first agent is an agent with a relatively small amount of solvent and contains components other than the non-aqueous epoxy compound (A1), and it also has good reactivity with the amine compound (C) described later.

[0019] The viscosity of the non-aqueous epoxy compound (A1) at 25°C, as measured with an E-type viscometer (TOKIMEC, FMD type, rotation speed: 60 rpm), is preferably 1,500 mPa·s or more, more preferably 3,000 mPa·s or more, preferably 120,000 mPa·s or less, more preferably 30,000 mPa·s or less, for example, 1,500 to 120,000 mPa·s.

[0020] The epoxy equivalent of the solid content of the non-aqueous epoxy compound (A1) is preferably 500 or less, more preferably 170 to 280, and even more preferably 170 to 210, from the standpoint of reducing the viscosity of the paint composition, reducing the content of volatile organic compounds (VOCs) in the paint composition, and forming a coating film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance. The epoxy equivalent is calculated based on JIS K 7236:2001.

[0021] Examples of non-aqueous epoxy compounds (A1) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, novolac type epoxy resin, cresol type epoxy resin, dimer acid modified epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, epoxidized oil-based epoxy resin, alkyl monoglycidyl ether, alkyl monoglycidyl ester, alkyl diglycidyl ether, alkyl diglycidyl ester, alkylphenol monoglycidyl ether, polyglycol monoglycidyl ether, and polyglycol diglycidyl ether. Preferred examples of the alkyl group (alkyl) include alkyl groups having 3 to 15 carbon atoms, specifically alkyl groups such as neopentyl groups and 2-ethylhexyl groups.

[0022] As the non-aqueous epoxy compound (A1), bisphenol A type epoxy resin or bisphenol F type epoxy resin is preferred because it can easily form a coating film with excellent corrosion resistance and adhesion to the substrate. Either bisphenol A type epoxy resin or bisphenol F type epoxy resin may be used, or both bisphenol A type epoxy resin and bisphenol F type epoxy resin may be used in combination.

[0023] The solid content of the non-aqueous epoxy compound (A1) in Composition 1 is preferably 1 to 35% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass, based on 100% by mass of the solid content of Composition 1. The solid content of the non-aqueous epoxy compound (A1) in the first agent of Kit 1 is preferably 40 to 90% by mass, more preferably 45 to 85% by mass, and even more preferably 50 to 80% by mass, based on 100% by mass of the solid content of the first agent. When the content of the non-aqueous epoxy compound (A1) is within the above range, it is preferable from the viewpoint that a coating film with excellent adhesion to the substrate, oil resistance, solvent resistance, chemical resistance, and corrosion resistance can be easily formed.

[0024] In this specification, components other than solvents such as organic solvents and water are referred to as "solids."

[0025] [Aqueous epoxy compound (A2)] The first component of this kit 2 contains aqueous epoxy compound (A2). Aqueous epoxy compound (A2) may consist of one type or two or more types.

[0026] Aqueous epoxy compounds (A2) refer to epoxy compounds that do not fall under non-aqueous epoxy compounds (A1). Specifically, when an epoxy compound and water are mixed at 23°C to a concentration of 3% by mass of the epoxy compound, thoroughly stirred, and allowed to stand at 23°C for 1 hour, if more than 10% by mass of the epoxy compound mixed with water is dissolved or dispersed in the water without separation, precipitation, or suspension, then the epoxy compound is considered an aqueous epoxy compound (A2). Aqueous epoxy compounds (A2) are epoxy compounds that use water as the main solvent or dispersion medium, or epoxy compounds that are miscible with water (dilutable with water). More specifically, examples include water-dispersible epoxy compounds, water-soluble epoxy compounds, and self-emulsifying epoxy compounds. The above-mentioned epoxy compounds that are miscible with water (dilutable with water) refer to epoxy compounds that do not show a significant increase in viscosity when mixed with water.

[0027] Furthermore, in the above mixture, if more than 10% by mass of the epoxy compound mixed with water is stably present in the water and the mixture is maintained in an emulsion state, the epoxy compound shall be considered a water-dilutable epoxy compound. In addition, in the above mixture, if more than 10% by mass of the epoxy compound mixed with water is stably present in the water and the epoxy compound mixed with water is present in a state where the average particle size measured by a laser diffraction particle size distribution analyzer (e.g., Mastersizer 3000 (manufactured by Spectris Co., Ltd.)) is less than 10 nm or no particles are observed, the epoxy compound shall be considered a water-soluble epoxy compound.

[0028] Aqueous epoxy compounds (A2) can be synthesized by conventionally known methods, such as solution polymerization, suspension polymerization, emulsion polymerization, seed polymerization, miniemulsification polymerization, microemulsification polymerization, and soap-free emulsion polymerization. Alternatively, the epoxy compounds may be emulsified by known methods, such as phase inversion emulsification, D-phase emulsification, forced emulsification, gel emulsification, inversion emulsification, and high-pressure emulsification.

[0029] In the preparation of the first agent, it is preferable to use a mixture containing an aqueous epoxy compound (A2) and water. Specifically, the mixture is preferably an epoxy compound emulsion or an epoxy compound dispersion, and more preferably an epoxy compound emulsion. Examples of epoxy compound emulsions include emulsions obtained by uniformly dispersing oil droplets containing an epoxy compound in an aqueous medium.

[0030] Epoxy compound emulsions can be prepared by forcibly emulsifying epoxy compounds in an aqueous medium, for example, by a phase inversion temperature emulsification method or a mechanical emulsification method. Examples of emulsifiers used include alkyl-type and alkylphenol-type nonionic surfactants; and anionic surfactants such as phosphate ester-type, alkylbenzene sulfonate-type, and sulfosuccinate-type surfactants. One or more of these emulsifiers may be used.

[0031] The solid content of the aqueous epoxy compound (A2) in the above mixture is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, based on 100% by mass of the above mixture, in order to obtain a paint composition that is superior in terms of ease of preparation, storage stability, etc. The above mixture may contain water, and may optionally contain conventionally known components such as surfactants.

[0032] The epoxy compound preferably has two or more epoxy groups in one molecule. In consideration of the water resistance of the coating film to be formed, and from the viewpoint of reducing the usage amount of the emulsifier, the epoxy compound may be a modified epoxy compound. Examples of the modification include modifying an epoxy compound into a self-emulsifying epoxy compound by introducing an emulsifying segment into the molecule through bonding the epoxy compound with one or more other compounds, and more specifically, introducing at least one selected from the group consisting of a polyoxyalkylene chain, a hydroxyl group, an amino group, a carboxyl group and the like into the epoxy compound. One of these modified epoxy compounds may be used alone, or two or more thereof may be used in combination.

[0033] Specific examples of the aqueous epoxy compound (A2) include bisphenol A type epoxy resins, bisphenol F 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, epoxidized oil-based epoxy resins, alkyl monoglycidyl ethers, alkyl monoglycidyl esters, alkyl diglycidyl ethers, alkyl diglycidyl esters, alkylphenol monoglycidyl ethers, polyglycol monoglycidyl ethers, and polyglycol diglycidyl ethers. Preferable examples of the alkyl group (alkyl) include alkyl groups having 3 to 15 carbon atoms, and specific examples include alkyl groups such as a neopentyl group and a 2-ethylhexyl group.

[0034] As the aqueous epoxy compound (A2), a bisphenol A type epoxy resin or a bisphenol F type epoxy resin is preferable from the viewpoint that a coating film excellent in corrosion resistance and adhesion to a substrate can be easily formed. Either a bisphenol A type epoxy resin or a bisphenol F type epoxy resin may be used, or a bisphenol A type epoxy resin and a bisphenol F type epoxy resin may be used in combination.

[0035] The epoxy equivalent of the solid content of the aqueous epoxy compound (A2) is preferably 150 to 6,000, more preferably 170 to 3,000, from the viewpoint such as easy formation of a coating film excellent in low-temperature drying curability, chemical resistance and corrosion resistance. The epoxy equivalent is calculated based on JIS K 7236:2001.

[0036] The content of the solid content of the aqueous epoxy compound (A2) in the present composition 2 is preferably 1 to 50% by mass, more preferably 5 to 45% by mass, still more preferably 10 to 40% by mass, based on 100% by mass of the solid content of the present composition 2. The content of the solid content of the aqueous epoxy compound (A2) in the first agent of the present kit 2 is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, still more preferably 20 to 40% by mass, based on 100% by mass of the solid content of the first agent. When the content of the aqueous epoxy compound (A2) is within the above range, it is preferable from the viewpoint such as easy formation of a coating film that is well-balanced and excellent in corrosion resistance and adhesion to a base material.

[0037] [Silicate Compound (B)] The present kit includes an agent containing the silicate compound (B). For example, the first agent of the present kit 1 further contains the silicate compound (B), and the third agent of the present kit 2 contains the silicate compound (B). The silicate compound (B) may be used alone or in combination of two or more kinds thereof.

[0038] One embodiment of this composition can form a coating that exhibits excellent curability even under high humidity or low temperature conditions (including both high humidity and low temperature conditions), is less prone to tack formation, and also has excellent walkability. The reasons for these effects are presumed to be as follows: When a coating is dried under high humidity or low temperature conditions, the evaporation rate of water from the coating is slow, and the coating remains wet for a long time. This causes non-aqueous components to rise to the surface of the coating due to their aversion to water, which contributes to tack formation. Furthermore, the uneven distribution of amine compounds and epoxy compounds causes curing delay. On the other hand, in this composition, it is thought that the hydrolysate of silicate compound (B) acts as a nucleus to promote the curing reaction between the amine compound and the epoxy compound. It is also thought that the silicate compound (B) rising to the surface of the coating during drying suppresses the rising of non-aqueous components. The silicate compound (B) that rises to the surface of the coating undergoes condensation with other silicate compounds (B) and simultaneously reacts with epoxy compounds, amine compounds, etc. Based on the above, it is presumed that the above effects were achieved by using this composition which contains silicate compound (B) along with the above components. Furthermore, by using silicate compound (B), the coating film formed from this composition also exhibits excellent chemical resistance (acid resistance and alkali resistance).

[0039] Examples of silicate compounds (B) include silane compounds and low-level condensates of silane compounds. Examples of silane compounds include alkoxysilanes such as tetraalkoxysilanes and alkylalkoxysilanes.

[0040] Examples of tetraalkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, and tetra-sec-butoxysilane. Examples of alkylalkoxysilanes include alkyltrialkoxysilane. Examples of alkyltrialkoxysilanes include methyltrialkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane; and ethyltrialkoxysilanes such as ethyltrimethoxysilane and ethyltriethoxysilane. The number of carbon atoms in the alkoxy group contained in the alkoxysilane is preferably 1 to 5, more preferably 1 to 3. The number of carbon atoms in the alkyl group contained in the alkylalkoxysilane is preferably 1 to 5, more preferably 1 to 3.

[0041] As for alkoxysilanes, alkoxysilanes that do not contain phenyl groups are preferred. When alkoxysilanes containing phenyl groups are used, steric hindrance results in inferior curability at high humidity or low temperatures (including both high humidity and low temperatures) compared to alkoxysilanes that do not contain phenyl groups, making it difficult to obtain sufficient tack resistance and walkability.

[0042] Low condensates of alkoxysilanes refer to condensates of alkoxysilanes having a degree of condensation of 2 to 20 (2 to 20 silicon atoms), preferably 3 to 18 (3 to 18 silicon atoms), more preferably 3 to 15 (3 to 15 silicon atoms), and even more preferably 3 to 10 (3 to 10 silicon atoms).

[0043] Among silicate compounds (B), low condensates of alkoxysilanes are preferred from the viewpoint of lowering the viscosity of the paint composition and balancing curability, and the compound represented by the following formula (B1) is more preferred.

[0044]

[0045] In the above formula (B1), R １ and R ２ Each of these is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. １ and X２ Each of these is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. n indicates the number of repeats. The alkyl group may or may not be substituted. Furthermore, the alkyl group may have a linear or branched structure.

[0046] Preferred silicate compounds (B) include tetramethoxysilane or its low condensates, tetraethoxysilane or its low condensates, tetra-n-propoxysilane, and tetra-n-butoxysilane. Among these, compounds with fewer carbon atoms in the alkyl group are preferred from the viewpoint of curing speed when the coating film dries, and tetramethoxysilane or its low condensates and tetraethoxysilane or its low condensates are more preferred.

[0047] Furthermore, it is preferable to use two or more silicate compounds (B) in combination, as this allows for the formation of a coating film that is less prone to tack even when dried under high humidity or low temperature conditions, and to obtain a paint composition with a long pot life. In one embodiment of this disclosure, it is more preferable to use silicate compound (B-a), which is tetraethoxysilane or a low condensate thereof, in combination with at least one silicate compound (B-b) selected from tetramethoxysilane or a low condensate thereof, tetra-n-propoxysilane, and tetra-n-butoxysilane. As this allows for the obtaining of a paint composition with excellent curing speed and a long pot life, the content of silicate compound (B-b) is preferably 1 to 100 parts by mass, more preferably 5 to 90 parts by mass, and even more preferably 15 to 80 parts by mass, per 100 parts by mass of silicate compound (B-a).

[0048] The number of repetitions n is preferably 2 to 20, more preferably 3 to 18, even more preferably 3 to 15, and particularly preferably 3 to 10, in order to obtain a paint composition with excellent curing speed.

[0049] The weight-average molecular weight (Mw) of silicate compound (B) is preferably 100 to 3,000, more preferably 150 to 2,000, and even more preferably 180 to 1,500. When Mw is above the lower limit, the curing rate of the coating film is fast and tack is less likely to occur, even under high humidity or low temperature conditions during drying. The above Mw is measured by gel permeation chromatography (GPC). The value obtained by the GPC method is a value (polystyrene equivalent) obtained using a calibration curve prepared with polystyrene as the standard substance.

[0050] The specific gravity (at 25°C) of silicate compound (B) is preferably as low as possible, but is preferably 0.7 to 1.4, and more preferably 0.8 to 1.3. When the specific gravity is below the above upper limit, tack tends to be less likely to occur when drying the coating film, even under high humidity or low temperatures.

[0051] The content of silicate compound (B) in this composition is preferably 0.05 to 35% by mass, more preferably 0.5 to 25% by mass, and even more preferably 1 to 15% by mass, based on 100% by mass of the solid content of this composition.

[0052] The content of silicate compound (B) in the first component of Kit 1 is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, and even more preferably 5 to 35 parts by mass, based on 100 parts by mass of the solid content of the non-aqueous epoxy compound (A1) in the first component.

[0053] The silicate compound (B) content in the composition 2 obtained using this kit 2 is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, and even more preferably 5 to 35 parts by mass, per 100 parts by mass of the solid content of the aqueous epoxy compound (A2).

[0054] When the silicate compound (B) content is within the above range, a coating film can be easily formed that exhibits excellent curing properties even under high humidity or low temperatures, is less prone to tack formation, and also has excellent walkability and chemical resistance.

[0055] [Amine Compound (C)] The second component of this kit contains amine compound (C). Amine compound (C) may be one type or two or more types.

[0056] Specific examples of amine compounds (C) include water-dilutable amine compounds and non-aqueous amine compounds. For example, when using a water-dilutable amine compound, it may be difficult to determine whether it was water-dilutable after mixing it with other components that may be included in the second agent. However, even in such cases, if a water-dilutable amine compound is used as a raw material when preparing the second agent, the second agent is said to contain a water-dilutable amine compound. The same applies to non-aqueous amine compounds.

[0057] A water-dilutable amine compound refers to an epoxy-curable amine compound that dissolves or disperses in a relatively large amount in the aqueous medium described above. Specifically, if, after mixing an amine compound with water at 23°C so that the solid content is 50% by mass, thoroughly stirring the mixture, and letting it stand at 23°C for 1 hour, at least 80% by mass of the solid content of the amine compound mixed with water remains uniformly in the water, then the amine compound is considered a water-dilutable amine compound. Furthermore, for components containing amine compounds with a solid content of less than 50% by mass, the solid content is adjusted to 50% by mass using an evaporator or the like. After that, it is evaluated in the same manner as above, and if the conditions are met, it is considered a water-dilutable amine compound.

[0058] Specific examples of the above-mentioned water-dilutable amine compounds include hydrophilic amine compounds obtained by reacting the following amine compounds used as curing agents for epoxy compounds with glycidyl ethers of polyalkylene glycols or polyoxyalkyleneamines, etc., amine compounds having an amide structure obtained using fatty acids and aliphatic amine compounds, or compounds obtained by forcibly dispersing the following amine compounds used as curing agents for epoxy compounds in water, after imparting emulsifying ability to them by neutralizing them with acid or mixing them with emulsifiers.

[0059] The term "non-aqueous amine compound" refers to an epoxy-curable amine compound that is not freely miscible with water, and refers to an epoxy-curable amine compound that is substantially insoluble in water. Specifically, when an amine compound and water are mixed such that the solid content is 3% by mass at 23°C, sufficiently stirred, and allowed to stand at 23°C for 1 hour, the resulting mixed solution is not in a uniform state, and 50% by mass or more of the solid content of the amine compound mixed with water is separated, precipitated or suspended, the amine compound is defined as a non-aqueous amine compound.

[0060] The amine compound used as a curing agent for epoxy compounds 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) and a flash rust inhibitor described later, and examples thereof include amine compounds having two or more amino groups in one molecule, and aliphatic, alicyclic, aromatic, and heterocyclic amine compounds are preferable.

[0061] Examples of the above aliphatic amine compounds include alkylene polyamines, polyalkylene polyamines, and alkylaminoalkylamines.

[0062] Examples of the above alkylene polyamines include those represented by the formula: "H ２ N-R １ -NH ２ " (wherein R １ is a divalent hydrocarbon group having 1 to 12 carbon atoms). Specific examples thereof 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.

[0063] Examples of the above polyalkylene polyamine include those represented by the formula: "H ２ N-(C ｍ H ２ｍ NH) ｎCompounds represented by (H) (where m is an integer from 1 to 10, and n is an integer from 2 to 10, preferably an integer from 2 to 6) are examples, and specific examples include diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, bis(hexamethylene)triamine, and triethylene-bis(trimethylene)hexamine.

[0064] Examples of the alkylaminoalkylamines mentioned above include formula: ２ ２ N-(CH ２ ) ｐ -NH ２ (R ２ These are independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (wherein at least one R) ２ Compounds represented by (a) are examples of compounds where (a) is an alkyl group having 1 to 8 carbon atoms, and p is an integer from 1 to 6. Specific examples include dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, and dimethylaminobutylamine.

[0065] Other aliphatic amine compounds include, for example, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, polyoxyalkylene polyamines (especially diethylene glycol bis(3-aminopropyl) ether), bis(aminomethyl)cyclohexane, isophoronediamine (IPDA), mensendiamine (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.

[0066] Specific examples of the above-mentioned alicyclic amine compounds include cyclohexanediamine, diaminodicyclohexylmethane (particularly 4,4'-methylenebiscyclohexylamine, 4,4'-methylenebis(2-methylcyclohexylamine)), 4,4'-isopropylidenebiscyclohexylamine, norbornanediamine, and 2,4-di(4-aminocyclohexylmethyl)aniline.

[0067] Examples of the above-mentioned aromatic amine compounds include aromatic polyamine compounds having two or more primary amino groups bonded to aromatic rings such as benzene rings or naphthalene rings. Specific examples of these aromatic amine compounds include phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, diaminodiethylphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, and diethylmethylbenzenediamine.

[0068] Specific examples of the above heterocyclic amine compounds include 1,4-diazacycloheptane, 1,4-bis(3-aminopropyl)piperazine, 1-[2'-(2''-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

[0069] Further examples of amine compounds used as curing agents for the epoxy compounds mentioned above include modified versions of the amine compounds, such as modified alicyclic polyamines, modified aliphatic polyamines, fatty acid modified products such as polyamidoamines, amine adducts with epoxy compounds, Mannich-modified amines (e.g., Mannich-modified amines having a phenol-derived skeleton (phenalkamine, phenalkamide, etc.)), Michael adducts, ketimines, and aldimines. Among these, modified alicyclic polyamines, modified aliphatic polyamines, polyamidoamines, amine adducts with epoxy compounds, and Mannich-modified amines having a phenol-derived skeleton are preferred.

[0070] The active hydrogen equivalent of the solid content of the amine compound (C) is preferably 20 to 200, more preferably 30 to 190, from the viewpoint of easily forming a coating film with excellent low-temperature drying and curing properties and corrosion resistance.

[0071] From the viewpoint of easily forming a coating film with excellent corrosion resistance, coating strength, and low-temperature drying and curing properties, it is desirable to use the amine compound (C) in an amount such that the reaction ratio calculated by the following formula (1) is preferably 0.3 to 1.5, more preferably 0.4 to 1.2.

[0072] Reaction ratio = {(Amount of solid content of amine compound (C) / Active hydrogen equivalent of solid content of amine compound (C)) + (Amount of solid content of component reactive with epoxy compound / Functional group equivalent of solid content of component reactive with epoxy compound)} / {(Amount of solid content of epoxy compound / Epoxy equivalent of solid content of epoxy compound) + (Amount of solid content of component reactive with amine compound (C) / Functional group equivalent of solid content of component reactive with amine compound (C))} ... (1)

[0073] Here, examples of epoxy compounds in formula (1) above include a non-aqueous epoxy compound (A1) and an aqueous epoxy compound (A2). Examples of the "component that reacts to the amine compound (C)" and the "component that reacts to the epoxy compound" in formula (1) above include silane coupling agents. As the silane coupling agent, a silane coupling agent having an amino group or an epoxy group as a reactive group can be used, so it is necessary to determine whether the silane coupling agent is reactive to the amine compound (C) or the epoxy compound depending on the type of reactive group, and to calculate the reaction ratio.

[0074] The "functional group equivalent" for each of the above components refers to the mass (g) per mol of functional group obtained by dividing the mass of 1 mol of these components by the number of mol of functional groups contained within it.

[0075] The solid content of amine compound (C) in this composition is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, and even more preferably 3 to 15% by mass, based on 100% by mass of the solid content of this composition. The solid content of amine compound (C) in the second component of this kit is preferably 5 to 100% by mass, more preferably 7 to 99% by mass, and even more preferably 10 to 99% by mass, based on 100% by mass of the solid content of the second component. When the content of amine compound (C) is within the above range, a coating film with excellent corrosion resistance and drying properties can be easily formed.

[0076] In one embodiment, the second agent of Kit 1 contains a water-dilutable amine compound and water, preferably a water-dilutable amine compound, a non-aqueous amine compound, and water. When the second agent of Kit 1 contains a water-dilutable amine compound and a non-aqueous amine compound, the solid content of the water-dilutable amine compound is preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, and even more preferably 20 to 60 parts by mass, based on 100 parts by mass of the solid content of the non-aqueous amine compound. The water content in the second agent of Kit is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, and even more preferably 20 to 40% by mass, based on 100% by mass of the second agent.

[0077] In one embodiment, the second agent of Kit 2 contains a non-aqueous amine compound. The water content in such a second agent is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the second agent.

[0078] In one embodiment, the second agent of Kit 2 further contains water in addition to the amine compound (C). The second agent contains, for example, at least one selected from water-dilutable amine compounds and non-aqueous amine compounds, and water. The water content in such a second agent is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 30 to 60% by mass, based on 100% by mass of the second agent.

[0079] [Water] To facilitate the preparation of this composition and improve its storage stability, this composition further contains water. Specifically, the second component of Kit 1 contains water, and the first component of Kit 2 contains water. The water is not particularly limited, and tap water may be used, but it is preferable to use deionized water.

[0080] The water content in this composition is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 18 to 30% by mass, based on 100% by mass of the composition. The water content is measured according to the Karl Fischer method using a moisture meter (e.g., CA-310, manufactured by Nitto Seikou Analytech Co., Ltd.).

[0081] [Other Components] This composition may further contain components other than those described above (hereinafter also referred to as "other components"). Unless otherwise specified, each agent in this kit may further contain other components. Examples of other components include non-reactive diluents, silane coupling agents, pigments, (pigment) dispersants, defoaming agents, viscosity modifiers (anti-sagging agents, anti-settling agents, thixotropes), flash rust inhibitors, curing accelerators, dehydrating agents, divalent or higher polycarboxylic acids, and film-forming aids. Each of the other components may be used individually or in combination of two or more.

[0082] Other components can be conventionally known components, and commercially available products may also be used.

[0083] <Non-reactive diluent> This composition may contain a non-reactive diluent. It is preferable that this composition contains a non-reactive diluent, as this can improve the flexibility of the resulting coating film. A non-reactive diluent refers to a compound that does not have a functional group that is reactive to epoxy groups or amino groups.

[0084] The above-mentioned non-reactive diluents can be broadly selected from conventionally known non-reactive diluents, including liquid hydrocarbon resins such as low-boiling fractions obtained by thermal decomposition of naphtha (including modified products of said liquid hydrocarbon resins), cardanol and cardanol derivatives prepared from cashew nut shell liquid, petroleum resins, xylene resins, and coumarone indene resins. Specifically, examples include the liquid hydrocarbon resins and flexibility-imparting resins described in Japanese Patent Application Publication No. 2006-342360.

[0085] Among these, liquid hydrocarbon resins, cardanol, and cardanol derivatives are preferred, and phenol-modified hydrocarbon resins, cardanol, and cardanol derivatives are more preferred, due to their excellent compatibility with the epoxy compounds (non-aqueous epoxy compounds (A1) or aqueous epoxy compounds (A2)). Examples of the phenol-modified hydrocarbon resins include resins obtained using diolefins, monoolefins, or α-methylstyrene contained in the cracked oil fractions of petroleum and coal, and phenols (phenol compounds), as described in Japanese Patent Publication No. 9-268209, Japanese Patent Publication No. 7-196793, etc.

[0086] More specifically, the above-mentioned phenol-modified hydrocarbon resins include C5-based (aliphatic) petroleum resins made from C5 fractions; C9-based (aromatic) petroleum resins made from C9 fractions; C5 / C9 copolymer petroleum resins; dicyclopentadiene resins made from dicyclopentadiene obtained by thermal dimerization of cyclopentadiene contained in the C5 fraction; α-methylstyrene; and resins obtained by reacting these with phenols. Among these, resins obtained by addition polymerization of styrene, vinyltoluene, coumarone, indene, and α-methylstyrene, which are contained in the cracked oil fractions of petroleum and coal, with phenols are preferred.

[0087] The average molecular weight of the above-mentioned phenol-modified hydrocarbon resin is typically 200 to 1,000, and its viscosity is typically 30 to 10,000 mPa·s / 25°C.

[0088] As a non-reactive diluent, an organic solvent may be used. Preferably, the organic solvent has a boiling point of less than 180°C at normal pressure. Examples include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), ether solvents such as butyl cellosolve, ester solvents such as butyl acetate, alcohol solvents such as isopropyl alcohol, isobutyl alcohol, n-butanol, and methoxypropanol, and aliphatic hydrocarbon solvents such as n-hexane, n-octane, 2,2,2-trimethylpentane, isooctane, n-nonane, cyclohexane, and methylcyclohexane.

[0089] If the composition contains an organic solvent, it is preferable to use an organic solvent such that the VOC content in the composition is within the following range. The first agent of Kit 1 is preferably a solvent-based agent containing an organic solvent, or a solvent-free agent. When preparing the first agent containing an organic solvent, it is preferable to use an organic solvent such that the content of the organic solvent is preferably 12% by mass or less, more preferably 10% by mass or less, preferably 1% by mass or more, more preferably 2% by mass or more, for example, 1 to 12% by mass, based on 100% by mass of the first agent.

[0090] If the composition contains a non-reactive diluent, the content of the non-reactive diluent is preferably 0.1 to 15% by mass, more preferably 1 to 10% by mass, based on 100% by mass of the composition. When the content of the non-reactive diluent is within the above range, a paint composition with a long pot life can be easily obtained.

[0091] <Silane Coupling Agent> This composition may contain a silane coupling agent. By using a silane coupling agent, a low-viscosity paint composition can be easily obtained, and not only can the adhesion of the resulting coating film to the substrate be further improved, but the corrosion resistance, such as water resistance and saltwater resistance, and heat resistance of the resulting coating film can also be improved.

[0092] The silane coupling agent is not particularly limited, and conventionally known compounds can be used. However, it is preferable that the compound has at least two functional groups within the same molecule and can contribute to improving adhesion to the substrate and reducing the viscosity of the composition.

[0093] Silane coupling agents include, for example, formula: "X-SiMe ｎ Y ３－ｎ It is preferable that the compound is represented by "[n is 0 or 1, X represents a functional group that can react with organic matter (e.g., amino group, vinyl group, epoxy group, mercapto group, halogeno group, a group in which part of a hydrocarbon group is substituted with these groups, or a group in which part of a hydrocarbon group is substituted with an ether bond, etc., and part of that group is substituted with these groups), Me is a methyl group, and Y represents a hydrolyzable group (e.g., alkoxy groups such as methoxy group and ethoxy group)].

[0094] When using a silane coupling agent that is reactive to an amine compound (C), such as an epoxy group-containing silane coupling agent, it is preferable to incorporate the silane coupling agent into the first agent. Furthermore, when using a silane coupling agent that is reactive to an epoxy compound (non-aqueous epoxy compound (A1) or aqueous epoxy compound (A2)), such as an amino group-containing silane coupling agent, it is preferable to incorporate the silane coupling agent into the second agent.

[0095] Among the silane coupling agents described above, it is preferable that the silane coupling agent contains an epoxy group, in which X is an epoxy group, a group in which part of a hydrocarbon group is substituted with an epoxy group, or a group in which part of a hydrocarbon group is substituted with an ether bond or the like and part of the group is substituted with an epoxy group.

[0096] If the composition contains a silane coupling agent, the content of the silane coupling agent is preferably 1 to 25% by mass, more preferably 2 to 15% by mass, based on 100% by mass of the solid content of the composition. When the content of the silane coupling agent is within the above range, the viscosity of the composition can be reduced, making it easy to obtain a low-viscosity paint composition with excellent paintability, and improving the adhesion, corrosion resistance, and heat resistance of the resulting coating film to the substrate.

[0097] <Pigments> This composition may contain pigments (excluding the flash rust inhibitors described below). Examples of pigments include extender pigments, coloring pigments, and rust-preventive pigments.

[0098] In one embodiment, the second component of Kit 1 contains at least one selected from water-dilutable amine compounds and non-aqueous amine compounds, and a pigment. When the second component of Kit 1 is in this form, it is possible to form an anticorrosive coating film with excellent corrosion resistance, particularly under salt spray and high temperature and humidity conditions.

[0099] When this composition contains pigments, the pigment mass concentration (PWC) in this composition is preferably 20 to 80%, more preferably 30 to 75%, in order to easily obtain a composition with excellent paintability, and to easily form an anticorrosive coating film with excellent adhesion to the substrate due to stress relaxation and water resistance. The above PWC refers to the percentage of the total mass of pigments relative to the mass of solids in this composition, and is expressed by the following formula (2): PWC [%] = Total mass of all pigments in this composition / Mass of solids in this composition × 100 ... (2)

[0100] When this composition contains a pigment, the volume concentration of the pigment (PVC) in this composition is preferably 20 to 50%, more preferably 20 to 45%, even more preferably 20 to 40%, and particularly preferably 20 to 38%, in order to easily obtain a composition with superior paintability, and to easily form a coating film with superior adhesion to the substrate due to stress relaxation and superior water resistance.

[0101] The above PVC refers to the total volume concentration of pigments relative to the volume of solids in this composition, and is expressed by the following formula (3): PVC [%] = Total volume of all pigments in this composition × 100 / Volume of solids in this composition ... Formula (3)

[0102] The volume of solids in the composition can be calculated from the mass and true density of the solids in the composition. The mass and true density of the solids may be measured values ​​or values ​​calculated from the raw materials used. The volume of the pigment can be calculated from the mass and true density of the pigment used. The mass and true density of the pigment may be measured values ​​or values ​​calculated from the raw materials used. For example, it can be calculated by separating the pigment from other components from the solids in the composition and measuring the mass and true density of the separated pigment.

[0103] 《Extender Pigments》 There are no particular restrictions on extender pigments, but they are pigments other than the coloring pigments and rust-preventive pigments listed below. Examples of the above extender pigments include conventionally known talc, mica, barium sulfate (including precipitated barium sulfate and elutriated barium sulfate), (potassium) feldspar, kaolin, alumina white, clay, magnesium carbonate, barium carbonate, calcium carbonate, dolomite, and silica. Among these, talc, mica, barium sulfate, and (potassium) feldspar are preferred.

[0104] If this composition contains extender pigments, the amount of extender pigments is preferably 1 to 60% by mass, more preferably 5 to 55% by mass, based on 100% by mass of the solid content of this composition, in order to easily form a coating film that is well balanced in terms of corrosion resistance, water resistance, adhesion to the substrate, and impact resistance.

[0105] 《Coloring Pigments》 There are no particular restrictions on the coloring pigments, but they are pigments other than the rust-preventive pigments listed below. Examples of the above coloring pigments include conventionally known inorganic pigments such as carbon black, titanium dioxide (titanium white), iron oxide (red iron oxide), yellow iron oxide, and ultramarine, and organic pigments such as cyanine blue and cyanine green. Among these, titanium white, carbon black, and red iron oxide are preferred.

[0106] If the composition contains a coloring pigment, its content is preferably 0.1 to 25% by mass, more preferably 0.5 to 20% by mass, based on 100% by mass of the solid content of the composition.

[0107] Rust-preventive pigments include, for example, zinc powder, zinc alloy powder, zinc phosphate compounds, calcium phosphate compounds, aluminum phosphate compounds, magnesium phosphate compounds, zinc phosphite compounds, calcium phosphite compounds, aluminum phosphite compounds, strontium phosphite compounds, aluminum tripolyphosphate compounds, molybdate compounds, zinc cyanamide compounds, borate compounds, nitro compounds, and complex oxides. Among these, aluminum phosphate compounds are preferred.

[0108] When this composition contains a rust-preventive pigment, its content is preferably 0.1 to 15% by mass, more preferably 1 to 15% by mass, based on 100% by mass of the solid content of this composition, in order to easily form a coating film that is well balanced in terms of corrosion resistance, water resistance, adhesion to the substrate, and impact resistance.

[0109] <(Pigment) Dispersant> The (pigment) dispersant is not particularly limited, but examples include various dispersants such as copolymers having compatible chains such as fatty acids, polyaminos, polyethers, polyesters, polyurethanes, polyacrylates, etc., which have pigment adsorption groups (pigment affinity groups) such as carboxyl groups, phosphate groups, amino groups, groups of these salts, and ammonium bases.

[0110] If the composition contains a (pigment) dispersant, the amount thereof is preferably 0.1 to 5% by mass, more preferably 0.1 to 4% by mass, based on 100% by mass of the solid content of the composition, in order to easily form a coating film in which the pigment and the like are uniformly dispersed and to easily form a coating film with excellent crack resistance.

[0111] <Antifoaming agent> An antifoaming agent may be added to this composition as needed for purposes such as suppressing the generation of foam during the preparation or application of this composition, or for breaking the foam generated in this composition to form a coating film with desired physical properties.

[0112] If the composition contains an antifoaming agent, the amount is preferably 0.005 to 1% by mass, more preferably 0.01 to 0.5% by mass, based on 100% by mass of the solid content of the composition, in order to sufficiently suppress the generation of foam and to easily form a coating film with the desired physical properties.

[0113] <Viscosity modifier> The viscosity modifier is not particularly limited, but it is preferable to use a material that can suppress the settling of pigments and the like in the composition and improve its storage stability, or a material that can improve the anti-sagging properties of the composition during and after painting.

[0114] As the viscosity modifiers mentioned above, conventionally known viscosity modifiers such as organic clay waxes including stearate salts, lecithin salts, and alkyl sulfonates of Al, Ca, and Zn; polyethylene wax; amide viscosity modifiers; amide neutralized salt viscosity modifiers; mixtures of amide viscosity modifiers; hydrogenated castor oil wax; mixtures of hydrogenated castor oil wax and amide wax; synthetic fine silica powder; oxidized polyethylene wax; and urea viscosity modifiers can be used. Among these, amide viscosity modifiers, amide neutralized salt viscosity modifiers, and mixtures of amide viscosity modifiers are preferred because they can further improve the anti-sagging properties of the composition during and after painting.

[0115] If the composition contains a viscosity modifier, the solid content of the viscosity modifier is preferably 0.1 to 10% by mass, more preferably 0.3 to 8% by mass, based on 100% by mass of the solid content of the composition. When the viscosity modifier content is within the above range, a paint composition with excellent paintability can be easily obtained.

[0116] <Flash Last Inhibitors> Examples of flash last 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; phytes 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; metal sulfonates; N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), and diethylenetriamine. Examples of chelating agents include amine-based chelating agents such as tetraacetic acid (DTPA), propylenediaminetetraacetic acid (PDTA), iminodiacetic acid, nitrilotriacetic acid (NTA), diethylenetriaminepentamethylenephosphonic acid (DTPMP), and their alkali metal salts; addition reaction products obtained using 4-methyl-γ-oxobenzenebutanoic acid and N-ethylmorpholine; intercalation compounds obtained by intercalating monoalkylamines, polyamines, and / or quaternary ammonium ions with layered phosphates such as aluminum dihydrogen tripolyphosphate; and hydrazine derivatives such as hydrazide compounds, semicarbazide compounds, and hydrazone compounds.

[0117] Among these, nitrites (e.g., metal salts such as sodium, potassium, and calcium, and ammonium salts) and benzoates (e.g., metal salts such as sodium, potassium, and calcium, and ammonium salts) are preferred due to their excellent flash-rust resistance and low cost. Nitrites are more preferred, and sodium nitrite is particularly preferred, as compositions exhibiting high flash-rust resistance can be easily obtained even with small amounts of use.

[0118] If the composition contains a flashlast inhibitor, the amount is preferably 0.01 to 2% by mass, more preferably 0.03 to 1% by mass, based on 100% by mass of the solid content of the composition, in order to easily obtain a composition with excellent flashlast resistance.

[0119] <Polycarboxylic acids with two or more valent properties> Polycarboxylic acids with two or more valent properties are organic acids having two or more carboxyl groups in one molecule. It is preferable that the second agent contains polycarboxylic acids with two or more valent properties, as this allows for easy acquisition of paint compositions with a long pot life and easy formation of a coating film with excellent corrosion resistance.

[0120] There are no particular limitations on the divalent or greater polycarboxylic acid, but examples include oxalic acid, malonic acid, succinic acid, malic acid, tartaric acid, glutaric acid, adipic acid, maleic acid, and citric acid. Among these, malic acid, succinic acid, and tartaric acid are preferred because they can easily form a coating film with superior corrosion resistance.

[0121] The molecular weight of the above-mentioned divalent or greater polycarboxylic acid is preferably 500 or less, more preferably 300 or less, and even more preferably 200 or less, from the viewpoint that a paint composition with a good balance of pot life and drying properties can be easily obtained.

[0122] When this composition contains a divalent or greater polycarboxylic acid, the content of the divalent or greater polycarboxylic acid is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, preferably 30 parts by mass or less, more preferably 25 parts by mass or less, for example 5 to 30 parts by mass, based on 100 parts by mass of solids of the amine compound (C), in order to easily obtain a paint composition with a long pot life and to easily form a coating film with excellent corrosion resistance.

[0123] <Film-forming aid> Because this composition contains water, it may freeze in winter, etc., and also to improve film-forming properties at low temperatures and the finished appearance of the resulting coating film, it may contain a film-forming aid.

[0124] As film-forming aids, film-forming aids commonly used in water-based paint compositions, such as organic compounds with a boiling point of 180°C or higher at room temperature, can be used. Examples include linear or branched aliphatic alcohols having 5 to 15 carbon atoms; alcohols having aromatic rings such as benzyl alcohol; monoethers such as (poly)ethylene glycol or (poly)propylene glycol; (poly)ethylene glycol ether esters; and (poly)propylene glycol ether esters.

[0125] When this composition contains a film-forming aid, the amount of the film-forming aid is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, based on 100% by mass of the solid content of this composition, in order to easily form a coating film with excellent film-forming properties and appearance at low temperatures.

[0126] [This composition] The solid content of this composition, calculated from the solid content and blending amount of each raw material, is preferably 60 to 85% by mass, more preferably 65 to 82% by mass, and even more preferably 70 to 80% by mass.

[0127] The content of volatile organic compounds (VOCs) in this composition is preferably 100 g / L or less, more preferably 90 g / L or less, and even more preferably 80 g / L or less, in order to ensure that the composition has minimal impact on the natural environment and the painting work environment.

[0128] The VOC content in this composition can be measured according to ISO 11890-1.

[0129] <Method for preparing the composition> Composition 1 can be prepared by mixing (kneading) a first agent containing a non-aqueous epoxy compound (A1) and a silicate compound (B) with a second agent containing an amine compound (C) and water. Composition 2 can be prepared by mixing (kneading) a first agent containing an aqueous epoxy compound (A2) and water with a second agent containing an amine compound (C) and a third agent containing a silicate compound (B).

[0130] The first agent, the second agent, and the third agent, if necessary, can be prepared by mixing (kneading) the components to be incorporated into these agents. During this mixing (kneading), the components may be added and mixed all at once, or added and mixed in multiple stages. Conventional equipment such as mixers, dispersers, and agitators can be used for the above mixing (kneading). Examples of such equipment include dispersers, mixing / dispersing mills, mortar mixers, rolls, paint shakers, and homogenizers. The above mixing (kneading) may also be carried out while heating, cooling, etc., depending on the season, environment, etc.

[0131] ≪Coating film, coated product, and method for manufacturing coated product≫ The coating film of this disclosure (hereinafter also referred to as "this coating film") is formed using this composition, specifically by drying (curing) this composition, and is usually formed on a substrate. The coated product of this disclosure includes a substrate and this coating film.

[0132] The material of the above-mentioned substrate is not particularly limited and includes, for example, iron (iron, steel, ferroalloy, carbon steel, mild steel, alloy steel, etc.), non-ferrous metals (zinc, aluminum, copper, brass, galvanized, zinc sprayed, etc.), and stainless steel (SUS304, SUS410, etc.). The surface of the substrate may be coated with a shop primer or the like. Furthermore, when using, for example, mild steel (SS400, etc.) as the substrate, it is desirable to prepare the surface of the substrate by polishing it with a grit blast or the like (e.g., adjusting it so that the arithmetic mean roughness (Ra) is about 30 to 75 μm) as necessary. The above-mentioned substrate may also be a substrate that has undergone pretreatment such as cleaning or blasting to remove rust, dirt, paint (old paint film), etc. adhering to the substrate.

[0133] The above-mentioned substrate is not particularly limited, but a substrate that requires abrasion resistance and corrosion resistance is preferred in order to better demonstrate the effects of using this composition, for example, (steel) structures such as ships, offshore structures, plants, bridges, tanks, and containers.

[0134] The dry film thickness of this coating is not particularly limited, but is preferably 10 to 600 μm, more preferably 10 to 500 μm, even more preferably 10 to 400 μm, and even more preferably 15 to 300 μm, from the viewpoint of obtaining a coating with sufficient abrasion resistance and corrosion resistance. For example, it may be 50 μm or more, 100 μm or more, or 130 μm or more. With conventional water-based paint compositions, it was difficult to achieve such large film thicknesses due to the slow evaporation rate of water. On the other hand, by using this composition, even when such large film thicknesses are achieved, curing delay does not occur and a coating that is less prone to tack can be formed.

[0135] The method for forming this coating film may involve forming the desired film thickness in a single coat, or it may involve forming the desired film thickness in two or more coats.

[0136] One embodiment of this coating film is a laminated coating film of two or more layers formed by applying the composition two or more times. For example, a coating film is formed with the first coat, and then the composition is applied again on top of the coating film to obtain a laminated coating film with two or more layers. There is no particular upper limit to the number of layers in the laminated coating film, but it is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 to 3. When conventional water-based paint compositions are applied multiple times, the curing speed is particularly slowed, and the effects of volatile components remaining in the coating film tend to cause internal delamination (where only the surface of the coating film dries first, and the inside remains soft), and interlayer delamination is likely to occur, making it difficult to form a laminated coating film and ensure interlayer adhesion. This tendency is particularly pronounced when forming a large film thickness or when painting in a high-humidity environment. On the other hand, when the composition is applied two or more times, even when dried under high-humidity conditions (e.g., relative humidity of 75% RH), interlayer delamination is less likely to occur, and a laminated coating film with good adhesion can be formed.

[0137] The above-mentioned painted product may further include at least one coating film selected from the group consisting of an undercoat film (primer film) for the purpose of improving adhesion to the substrate and corrosion resistance, an intermediate coat film for the purpose of improving corrosion resistance, and a topcoat film for the purpose of weather resistance or aesthetics.

[0138] When this composition is used as a substitute for zinc primer, the coated product may include an intermediate coating or a topcoat on top of this coating.

[0139] Examples of undercoat coatings include coatings formed from various primer compositions such as epoxy resins. Examples of intermediate coatings include coatings formed from various intermediate coating compositions such as (meth)acrylic resins, epoxy resins, and urethane resins. Examples of topcoat coatings include coatings formed from various topcoat compositions such as (meth)acrylic resins, (meth)acrylic silicone resins, urethane resins, silicone resins, and fluororesin resins. The composition of this composition may be changed to form undercoat coatings, intermediate coatings, and topcoat coatings.

[0140] The method for manufacturing a coated product according to the present disclosure includes steps [1]: applying the composition to a substrate, and step [2]: drying the applied composition to form a coating film. When forming a laminated coating film, the manufacturing method may also include steps of applying the composition on the coating film after forming the first layer in step [2], and drying the applied composition to form a second layer. Furthermore, these steps may be repeated to form three or more layers of coating film. Here, the coating method, coating conditions, drying conditions, and the dry film thickness of the resulting coating film for the second and subsequent layers may be the same as or different from those for the first layer.

[0141] <Step [1]> The painting method in Step [1] is not particularly limited and includes conventionally known methods such as spray painting including airless spray painting and air spray painting, brush painting, and roller painting. Among these, spray painting is preferred because it can easily paint large surface areas of substrates such as the above-mentioned structures. When painting in this manner, it is preferable to paint so that the dry film thickness of the resulting coating is within the above range.

[0142] The conditions for spray painting can be adjusted as appropriate depending on the desired dry film thickness. For example, in the case of airless spray painting, a primary (air) pressure of approximately 0.3 to 0.6 MPa, a secondary (paint) pressure of approximately 10 to 15 MPa, and a gun travel speed of approximately 50 to 120 cm / second are preferred.

[0143] The viscosity of this composition, suitable for spray coating, is preferably 6,000 to 20,000 mPa·s, more preferably 8,000 to 12,000 mPa·s, measured at 23°C using a B-type viscometer (manufactured by Rion Co., Ltd., model VT-04F).

[0144] Furthermore, when applying this composition, the viscosity of the paint composition may be adjusted to an appropriate level as desired. Water is preferably used as the diluent for such viscosity adjustment. In this case, it is preferable to use a diluent that results in a paint viscosity suitable for each painting method. For example, when using airless spray painting, the amount of diluent used per 100 parts by mass of this composition is preferably 1 to 30 parts by mass.

[0145] <Step [2]> The drying conditions in Step [2] are not particularly limited and may be set appropriately depending on the coating film formation method, substrate type, application, painting environment, etc.

[0146] This composition exhibits excellent curability and can be dried at low temperatures. Therefore, it may be cured by forced drying with heat or airflow if desired, but it is usually dried and cured at 1 to 35°C. On the other hand, the drying time varies depending on the drying method of the coating film. When drying within the above temperature range, it is usually 1 hour to 7 days, preferably 1 to 3 days, and when forced drying, it is usually 5 to 60 minutes, preferably 10 to 30 minutes.

[0147] [Examples of Embodiments] This disclosure relates, for example, to the following <1> to <9>. <1> A water-based paint composition kit comprising: a first agent containing a non-aqueous epoxy compound (A1) and a silicate compound (B); and a second agent containing an amine compound (C) and water. <2> The water-based paint composition kit according to <1>, wherein the content of the silicate compound (B) in the first agent is 1 to 50 parts by mass per 100 parts by mass of the solid content of the non-aqueous epoxy compound (A1). <3> A water-based paint composition kit comprising: a first agent containing an aqueous epoxy compound (A2) and water; a second agent containing an amine compound (C); and a third agent containing a silicate compound (B). <4> The water-based paint composition kit according to <3>, wherein the second agent further contains water.

[0148] <5> A water-based paint composition obtained by mixing the first agent and the second agent in the water-based paint composition kit described in <1> or <2>, or by mixing the first agent, the second agent and the third agent in the water-based paint composition kit described in <3> or <4>.

[0149] <6> A coating film formed from the water-based paint composition described in <5>.

[0150] <7> The coating film according to <6>, which is a laminated coating film of two or more layers formed from the water-based coating composition.

[0151] <8> A painted product comprising a base material and a coating film as described in <6> or <7>.

[0152] <9> A method for manufacturing a painted product, comprising the steps of: applying the water-based paint composition described in <5> to a substrate [1]; and drying the water-based paint composition applied to the substrate to form a coating film [2].

[0153] The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, the amounts in the table represent "parts by mass".

[0154] [Examples 1-15 and Comparative Examples 1-3] The first component was prepared by placing each component listed in the "First Component" column of Tables 1 and 2 into a container in the amounts (numerical value, parts by mass) listed in Tables 1 and 2, and stirring with a high-speed disperser at room temperature (23°C) for 30 minutes. The second component was prepared by placing each component listed in the "Second Component" column of Tables 1 and 2 into a separate container in the amounts (numerical value, parts by mass) listed in Tables 1 and 2, and stirring with a high-speed disperser until the temperature reached 45-50°C. The prepared first component, second component, and the third component listed in the "Third Component" column of Table 2, which may be used as needed, were mixed in the mixing ratio (mass%) listed in Tables 1 and 2 to prepare the water-based paint composition in the total volume of Tables 1 and 2. A description of each component listed in Tables 1 and 2 is shown in Table 3.

[0155] [Solid Content] The solid content (amount of solids in 100% by mass of the composition) in the prepared water-based paint composition was calculated from the solid content and blending amount of each raw material. The results are shown in Tables 1 and 2.

[0156] [PWC] The mass concentration (PWC) of pigments in the prepared water-based paint composition was calculated based on formula (2) above. The results are shown in Tables 1 and 2.

[0157] [PVC] The volume concentration of pigment (PVC) in the prepared water-based paint composition was calculated based on formula (3) above. The results are shown in Tables 1 and 2.

[0158] [Reaction Ratio] The reaction ratio in the prepared water-based paint composition was calculated based on formula (1) above. The results are shown in Tables 1 and 2.

[0159] [Drying and Curing Properties] The prepared water-based coating composition was applied to a glass plate measuring 348 mm x 25 mm x 2 mm (thickness) using a film applicator so that the dry coating film thickness was 150 μm. Under conditions of 5°C and 70% RH relative humidity, an RC-type drying time recorder (manufactured by Coating Tester Co., Ltd.) was used to slowly move the test needle of the RC-type drying time recorder over the coating film at a constant speed (a speed that sets the measurement time to 24 hours). The state of the coating film was determined from the trace left by the test needle, and the time from immediately after the formation of the coating film until the coating film was semi-cured (semi-curing time) was determined. The results are shown in Tables 1 and 2. Specifically, the semi-curing time is as follows. Figure 1 shows a schematic plan view (schematic explanatory diagram) of the glass plate 2 on which the coating film 1 is formed, viewed from above on the side of the coating film 1. Position a is the position where the test needle is placed in contact with the coating film 1 formed on the glass plate 2 and the movement of the test needle begins. Position b is the position where the glass plate 2, on which the coating film 1 is formed, is no longer visible (due to the coating film 1) when viewed from above on the side of the coating film 1. Position c is the position where the test needle slides along the surface of the coating film 1 and no longer leaves any marks on the surface of the coating film 1. The time required for the test needle to move from position a to position b was defined as the half-curing time (the time required for the test needle to move from position a to position c was defined as the complete curing time).

[0160] [Tack] The prepared water-based coating composition was applied to a tin plate (150 mm x 70 mm x 0.3 mm (thickness)) using an applicator to achieve a dry film thickness of 200 μm. The samples were left to stand at 5°C and 70% RH relative humidity. After 24 and 48 hours, the surface of the coating on the test piece was pressed with a finger to evaluate the presence or absence of tack. The evaluation criteria are as follows.

[0161] <Evaluation Criteria> 5: No stickiness is felt. 4: Slight stickiness is felt, but no finger marks are left on the coating surface. 3: Sticky, the test piece does not lift when you try to remove your finger from it, but finger marks are left on the coating surface. 2: Sticky, the test piece lifts slightly before separating from your finger when you try to remove it. 1: Sticky, the test piece lifts when you try to remove your finger from it and does not separate from your finger.

[0162] [Walkability] Sandblasted SS400 steel plates measuring 150 mm x 70 mm x 2.3 mm (thickness) (arithmetic mean roughness (Ra): 30-75 μm) were prepared. The prepared water-based coating compositions were applied to the surface of these steel plates using an applicator to achieve a dry film thickness of 200 μm for each composition. The steel plates immediately after application of each water-based coating composition were dried for 24 hours and 48 hours under conditions of 5°C and 70% RH relative humidity. After each drying time, the test pieces were stepped on with shoes, and the condition of the coating surface after twisting with the heel of the shoe was evaluated. The evaluation criteria are as follows.

[0163] <Evaluation Criteria> 5: No damage to the coating, and no dirt adhering to the coating surface. 4: No damage to the coating, but dirt is visible on the coating surface. 3: No peeling of the coating, but slight scuff marks remain on the coating surface. 2: No peeling of the coating, but damage marks from twisting of the coating remain. 1: The coating has peeled off, exposing the surface of the underlying sandblasted steel plate.

[0164] [Pot Life] 300 g of each water-based paint composition prepared in Examples 1-12 and Comparative Example 1 was weighed into a container and adjusted with water so that the viscosity of each water-based paint composition at 23°C (Rion Viscometer: VT-04F, manufactured by Rion Co., Ltd.) was 2,000 mPa·s. Then, the viscosity (at 5°C) was measured after holding in a constant temperature bath at 5°C for 30 minutes and 60 minutes. The results are shown in Table 1.

[0165] [Chemical Resistance] Test plates were prepared by applying the prepared water-based paint composition to 150 mm x 70 mm x 2.3 mm (thickness) SS400 sandblasted steel plates (arithmetic mean roughness (Ra): 30-75 μm) using an air spray so that the dry film thickness was 150 μm, and drying at 23°C for 7 days. The test plates were immersed in various chemicals, including 5% sulfuric acid and 5% sodium hydroxide aqueous solution, at 23°C for 30 days. The evaluation criteria for the test plates after immersion are as follows. Note that a chemical resistance rating of 2 or higher is considered to be practically acceptable.

[0166] <Evaluation Criteria> 3: No rust has formed on the steel plate, and the coating is not peeling, blistering, cracking, or softening from the steel plate. 2: No rust has formed on the steel plate, and the coating is not peeling, blistering, or cracking from the steel plate, but slight softening is observed. 1: Rust has formed on the steel plate, and the coating is peeling, blistering, or cracking from the steel plate.

[0167] [Same-type recoating properties] A 300 mm x 100 mm x 2.3 mm (thickness) SS400 sandblasted steel plate (arithmetic mean roughness (Ra): 30-75 μm) was prepared. The prepared water-based paint composition was applied to the surface of this steel plate using an applicator to achieve a dry film thickness of 150 μm for each layer. The painted steel plate was dried for 18 hours at a temperature of 23°C and a relative humidity of 75% RH. After 18 hours, each of the water-based paint compositions was applied to the painted plate using an applicator to achieve a dry film thickness of 250 μm for each layer, and dried under the same conditions as the first layer. Seven days after applying the second layer, X-shaped cuts were made in the paint film, and the interlayer adhesion between the first and second layers was evaluated by inserting a utility knife into the cuts. The evaluation criteria are as follows.

[0168] <Evaluation Criteria> ○: No delamination was observed between the first and second layers, indicating good adhesion. ×: Delamination was observed between the first and second layers, indicating poor adhesion.

[0169]

[0170]

[0171]

[0172] 1: Coating film 2: Glass plate 3: Mark left by the test needle a: Starting position of the test needle b: Position where the glass plate is no longer visible c: Position where the test needle has slid across the coating surface and no longer leaves any marks on the coating surface

Claims

1. A water-based paint composition kit comprising: a first agent containing a non-aqueous epoxy compound (A1) and a silicate compound (B); and a second agent containing an amine compound (C) and water.

2. The aqueous coating composition kit according to claim 1, wherein the content of silicate compound (B) in the first agent is 1 to 50 parts by mass per 100 parts by mass of the solid content of the non-aqueous epoxy compound (A1).

3. A water-based paint composition kit comprising: a first agent containing an aqueous epoxy compound (A2) and water; a second agent containing an amine compound (C); and a third agent containing a silicate compound (B).

4. The water-based paint composition kit according to claim 3, wherein the second agent further comprises water.

5. A water-based paint composition obtained by mixing the first agent and the second agent in the water-based paint composition kit according to claim 1 or 2, or by mixing the first agent, the second agent and the third agent in the water-based paint composition kit according to claim 3 or 4.

6. A coating film formed from the water-based coating composition described in claim 5.

7. The coating film according to claim 6, which is a laminated coating film of two or more layers formed from the water-based coating composition.

8. A coated article comprising a substrate and a coating film according to claim 6 or 7.

9. A method for manufacturing a painted product, comprising the steps of: [1] coating a substrate with the water-based paint composition described in claim 5; and [2] drying the water-based paint composition coated on the substrate to form a coating film.

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