JP2012067224A - Aqueous primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous primer composition formable of a coating film that has excellent workability and corrosion resistance in the worked portion.SOLUTION: The aqueous primer composition includes a carbonyl group-containing modified epoxy resin (A), a crosslinking agent (B), and a rust preventive pigment (C). The carbonyl group-containing modified epoxy resin (A) is produced by reacting an amine compound (a) having a carbonyl group and at least one active hydrogen bonded to a nitrogen atom per molecule and an epoxy resin (b) having two or more epoxy groups per molecule.

Description

  The present invention relates to an aqueous primer composition containing a carbonyl group-containing modified epoxy resin capable of forming a coating film excellent in processability and corrosion resistance of a processed part.

  Pre-coated steel sheets are widely used in building materials such as roofs, walls, shutters, etc. of buildings, home appliances, and steel furniture. Since the precoated steel sheet is processed into various forms corresponding to such a wide application, the coating film on the steel sheet is required to have excellent workability. Although the above workability has been improved by improving the physical properties of the top coat film, problems such as cracking of the paint film and the occurrence of rust still remain in the processed part. Therefore, not only the top coating film but also the primer coating film is strongly desired to improve not only the corrosion resistance which is the original function but also the workability. In conventional primers, a composition mainly composed of an epoxy resin is used as a base resin, but a linear polyester resin is used at a ratio of 50% by mass or more of the resin component in order to improve the workability of the primer coating film. The primer composition used is disclosed in US Pat. However, since the coating film obtained from this primer composition has poor adhesion to the steel sheet, the corrosion resistance may be insufficient.

  Patent Document 2 discloses a self-curing amide epoxy resin into which an amide bond having strong hydrogen bonding properties is introduced. The amide epoxy resin can be obtained by reacting a compound obtained by the Michael addition reaction of an amine compound and an acrylamide compound with an epoxy resin, but some of the epoxy groups contained in the epoxy resin remain unreacted. The remaining epoxy group is used as a crosslinking reactive group for the crosslinking reaction of the coating film. The resin disclosed in Patent Document 2 can be applied to a thermosetting paint such as a primer, and the obtained coating film is excellent in corrosion resistance but has insufficient workability, causing cracks in the processed portion. There was a thing.

  On the other hand, in recent years, adverse effects on the environment due to volatilization of organic substances into the atmosphere have become a problem, and there is an urgent need to reduce the use of organic solvents. In Patent Document 3, a resin obtained by copolymerizing an unsaturated aromatic epoxy resin obtained by adding an unsaturated carboxylic acid to an aromatic epoxy resin and an unsaturated carboxylic acid is neutralized with a basic compound and water is added. Dispersed water dispersible resin compositions are disclosed. The coating film obtained from this composition may cause cracks in the processed part, and the corrosion resistance of the processed part may be insufficient.

JP-A-6-220355 Japanese Patent Laid-Open No. 7-48435 JP-A-6-136241

  Accordingly, an object of the present invention is to provide an aqueous primer composition capable of forming a coating film having excellent processability and processed part corrosion resistance.

As a result of intensive studies to achieve the above object, the present inventors have reacted an amine compound (a) having a carbonyl group with an epoxy resin (b) having two or more epoxy groups in one molecule. The present invention has found that the above-mentioned problems can be solved by an aqueous primer composition comprising a carbonyl group-containing modified epoxy resin (A), a crosslinking agent (B) and a rust preventive pigment (C) produced by It came to complete. That is, the present invention comprises the following items.
1. An amine compound (a) having at least one active hydrogen bonded to a nitrogen atom and having a carbonyl group is reacted with an epoxy resin (b) having two or more epoxy groups in one molecule. A water-based primer composition comprising a modified carbonyl group-containing epoxy resin (A), a crosslinking agent (B) and a rust preventive pigment (C).
2. The amine compound (a) is produced by a Michael addition reaction between diacetone acrylamide and an amine compound (c) having two or more active hydrogens bonded to a nitrogen atom in one molecule. An aqueous primer composition according to claim 1.
3. 2. The aqueous primer composition according to 1, wherein the carbonyl group-containing modified epoxy resin (A) has at least one hydrophilic group selected from the group consisting of an anionic group, a cationic group and a nonionic group. object.
4). 2. The aqueous primer according to 1, wherein the crosslinking agent (B) is at least one crosslinking agent selected from the group consisting of an isocyanate compound, a blocked isocyanate compound, an amino resin, a phenol resin, a hydrazide compound, and a semicarbazide compound. Composition.
5. 2. The aqueous primer composition according to 1, wherein the antirust pigment (C) contains a vanadium compound (c1), a silicon-containing compound (c2), and a phosphoric acid compound (c3).
6). A coated metal plate, wherein a cured coating film based on the aqueous primer composition according to any one of 1 to 5 is formed on one or both surfaces of a metal plate that may be subjected to chemical conversion treatment on the surface.

  According to the aqueous primer composition of the present invention, a primer coating film excellent in workability and processed part corrosion resistance can be obtained.

  Hereinafter, the aqueous primer composition of the present invention will be described in more detail. The aqueous primer composition of the present invention comprises a carbonyl group-containing modified epoxy resin (A), a crosslinking agent (B) and a rust preventive pigment (C).

[Carbonyl group-containing modified epoxy resin (A)]
The carbonyl group-containing modified epoxy resin (A) has at least one active hydrogen bonded to a nitrogen atom in one molecule, and at least two amine compounds (a) having a carbonyl group and an epoxy group in one molecule. It can manufacture by making it react with the epoxy resin (b) which has. The amine compound (a) can be obtained by a Michael addition reaction between diacetone acrylamide and an amine compound (c) having two or more active hydrogens bonded to a nitrogen atom in one molecule.

  The amine compound (c) may be a compound containing an oxygen atom, a sulfur atom, a nitrogen atom, etc., for example, methylamine, ethylamine, propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine. , T-butylamine, hexylamine, 2-methoxyethylamine, 2-ethoxyethylamine, 3-methoxypropylamine, 3-methylthiopropylamine, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylene Pentamine, iminobispropylamine, methyliminobispropylamine, lauryliminobispropylamine, N, N′-bisaminopropyl-1,3-propylenediamine, N, '-Bisaminopropyl-1,3-butylenediamine, 1,2-diaminopropane, bis- (3-aminopropyl) ether, bis- (3-aminopropoxy) ethane, 1,3bis- (3-aminopropoxy) C1-C16 such as -2,2-dimethylpropane, N-laurylpropylenediamine, N, N'-di-t-butylethylenediamine, N-methylethylenediamine, N-ethylethylenediamine, N, N-dimethylethylenediamine, allylamine An aliphatic compound having a carbon number of: cyclopentylamine, cyclohexylamine, cycloheptylamine, cyclooctylamine, aminomethylcyclohexane, 4-methylcyclohexylamine, 1-cyclohexylethylamine, 3,3,5-trimethylcyclohexylamine, Cycloaliphatic compounds having C1 to C16 carbon atoms such as Rondiamine and bisaminomethylcyclohexane; benzylamine, phenethylamine, 4-methylbenzylamine, N-aminopropylaniline, 2-amino-1,2-diphenylethanol 9-aminofluorene, benzhydrylamine, xylylenediamine, phenylenediamine, diaminodiphenylmethane, N-benzylethylenediamine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2,3-diaminopyridine, 2,5 -Diaminopyridine, 2,3,6-triaminopyridine, N-aminopropylaniline, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-6-methylpyridine, 2-amino -3-ethylpyridine, 2- C1-C16 such as mino-3-propylpyridine, 2-amino-4,6-dimethylpyridine, 2,6-diamino-4-methylpyridine, 3-amino-6-isopropylpyridine, 2,6-diaminopyridine and the like. Aromatic compounds having carbon number; piperazine, N-aminopropylpiperazine, 2-methylpiperazine, 2,6-dimethylpiperazine, 2,5-dimethylpiperazine, 3-methylaminopiperidine, 2-aminomethylpiperazine, 3-amino Pyrrolidine, homopiperazine, N-aminopropylpiperazine, 1,4- (bisaminopropyl) piperazine, N-aminoethylpiperidine, N-aminopropylpiperidine, 2-aminomethylpiperidine, 4-aminomethylpiperidine, furfurylamine, tetrahydro Furfurylamine, 3- ( Heterocyclic compounds having C1-C16 carbon number such as methylamino) pyrrolidine, 5-methylfurfurylamine, 2- (furfurylthio) ethylamine, 2-picolylamine, 3-picolylamine, 4-picolylamine; 2-hydroxy Ethylamine, methyl (2-hydroxyethyl) amine, 1-amino-2-propanol, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, diethanolamine, 3-amino-1 , 2-propanediol, 2- (2-aminoethoxy) ethanol, N- (2-hydroxyethyl) ethylenediamine, compounds having one or more hydroxyl groups such as 2-amino-1,3-propanediol, etc. Can be mentioned.

  Among the amine compounds (c), an amine compound having one primary amino group in one molecule, an amine compound having one primary amino group and one secondary amino group in one molecule, and secondary amino group In view of the fact that the amine compound having two groups in one molecule and the amine compound having two primary amino groups in one molecule can increase the carbonyl group concentration of the carbonyl group-containing modified epoxy resin in the present invention, It is preferable from the viewpoint of easy adjustment of the molecular weight.

  When n-butylamine having one primary amino group in one molecule is selected as the amine compound (c), the reaction for producing the amine compound (a) by Michael addition reaction to diacetone acrylamide is represented by the following formula (1) Indicated by

  Further, when N-ethylethylenediamine, which is an amine compound having one primary amino group and one secondary amino group in the molecule, is selected as the amine compound (c), an amine by Michael addition reaction to diacetone acrylamide The reaction for producing the compound (a) is represented by the following formula (2).

  The Michael addition reaction in the present invention is usually carried out in the range of 0 to 200 ° C., preferably in the range of 50 to 120 ° C., to obtain the amine compound (a) as a desired reaction product in a short time. It is preferable from the point that it can be suppressed and a side reaction can be suppressed. Mixing so that the molar ratio of diacetone acrylamide and amine compound (c) is within the range of 1 / 0.8 to 1 / 5.0, and further within the range of 1 / 0.9 to 1 / 2.2. Thus, it is preferable to perform the Michael addition reaction from the viewpoint that unreacted diacetone acrylamide does not remain and the production of a compound that does not have active hydrogen that reacts with the epoxy group is suppressed.

  The Michael addition reaction can be carried out in the presence of water or an organic solvent, but is not particularly required. When using an organic solvent, the kind is not specifically limited, However, Well-known organic solvents, such as ester type, ether type, and alcohol type, can be used. When water or an organic solvent is used, the concentration of the reaction solution is preferably 20% or more, more preferably 50% or more. If it is more dilute than this, it is not preferable because the reaction hardly proceeds. The reaction time is usually 30 minutes to 5 hours, although it varies depending on the type of amino compound used.

  From the standpoint of corrosion resistance, the Michael addition reaction is preferably carried out with a colorless medium, but a catalyst can be used if necessary. The catalyst is not particularly limited. For example, metal alkoxides such as sodium methoxide, sodium ethoxide and magnesium ethoxide; metal phenoxides such as sodium phenoxide; metal carboxylates such as sodium benzoate and potassium benzoate; triethylamine , Triethylenediamine, N, N-diethylaniline, N, N-dimethylaniline, N, N-dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, N, N'-dimethylpiperazine, pyridine, picoline, 1, Tertiary amines such as 8-diaza-bicyclo (5,4,0) undecene-7; tetraethylammonium bromide, tetrabutylammonium bromide, benzyltriethylammonium chloride, trioctylmethylammonium chloride, cetyltrimethyl bromide Quaternary ammonium salts such as ruammonium, tetrabutylammonium iodide, dodecyltrimethylammonium iodide, benzyldimethyltetradecylammonium acetate; quaternary such as tetraphenylphosphonium chloride, triphenylmethylphosphonium chloride, tetramethylphosphonium bromide Phosphonium salt; 2-methylimidazole, 2-ethylimidazole, 2-methyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, Basicity of imidazole compounds such as 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-azine-2-methylimidazole and the like Compounds. The catalyst is not limited to one type, and a plurality of types can be used. When using a catalyst, the usage-amount is preferable 10 mol% or less with respect to the usage-amount of an amine compound, and multiple types can also be used as needed.

  The amine compound (a) produced by the Michael addition reaction is obtained as a mixture with an unreacted amine compound (c) or a compound in which the carbonyl group in the Michael addition reaction product is ketiminated by the amine compound. There is.

  When a large amount of unreacted amino compound is contained, in the reaction between the amine compound (a) and the epoxy resin (b) described later, the carbonyl group-containing modified epoxy resin is extremely polymerized and thereby gelled. Since it may be, it is preferable to remove.

  Removal of the amine compound (c) from the mixture containing the amine compound (a) can be performed by distillation or azeotropy with water and / or an organic solvent under normal pressure or reduced pressure conditions. As the organic solvent, the solvent used in the Michael addition reaction can be used, but a known solvent such as alcohol or ether may be further added after the Michael addition reaction.

  Further, when the mixture containing the amine compound (a) contains a ketiminated compound, the viscosity of the carbonyl group-containing modified epoxy resin produced by the reaction between the mixture and the epoxy resin may increase. . Furthermore, in the aqueous primer composition containing the carbonyl group-containing modified epoxy resin, the ketiminated portion may be hydrolyzed into a volatile organic compound. Therefore, the above problem can be solved by adding excess water to the mixture obtained by the Michael addition reaction to hydrolyze the ketiminated portion of the ketiminated compound to regenerate the carbonyl group. preferable. The amine compound produced by this hydrolysis can be removed in the same manner as the unreacted amine compound.

  The removal of the unreacted amine compound and the amine compound produced by hydrolysis of the ketiminated compound shown here can be performed simultaneously with the Michael addition reaction or after the completion of the Michael addition reaction. May be.

Diacetone acrylamide is derived from a hydrogen atom bonded to a carbon atom forming a carbon-carbon double bond (CH ₂ ═CH) at 6.19 to 6.23 ppm in ¹ H-NMR measurement using a deuterated chloroform solvent. A peak to be observed is observed. In the measurement of ¹ H-NMR using a deuterated chloroform solvent of the reaction product, no peak is observed at 6.19 to 6.23 ppm. Therefore, in the present invention, the measurement of the Michael addition reaction is performed by the NMR measurement. The reaction rate can be observed.

  In the reaction between the amine compound (a) and the epoxy resin (b), the amine compound (a) may be used alone having at least one active hydrogen bonded to a nitrogen atom, but different numbers. These amine compounds having active hydrogen or different types of amine compounds may be used in combination.

  In the present invention, the epoxy resin (b) having two or more epoxy groups in one molecule is not particularly limited as long as it has two or more epoxy groups in the molecule. The epoxy resin (b) is obtained by reacting, for example, polyphenols such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A / F type epoxy resin, and novolac type phenol resin with epihalohydrin such as epichlorohydrin. Epoxy resin such as aliphatic epoxy resin and cycloaliphatic epoxy resin; epoxy resin obtained by further reacting polyphenols with the resin obtained by introducing a group or this glycidyl group introduction reaction product; Epoxy group-containing acrylic copolymers obtained by copolymerizing group-containing polymerizable unsaturated monomers and other polymerizable unsaturated monomers; polybutadiene resins having epoxy groups; polyurethane resins having epoxy groups, and the like. . The epoxy resin (b) has an epoxy equivalent of 140 to 5,000, preferably 150 to 2,000 and a number average molecular weight of 200 to 50,000, preferably 160 to 10. , 000 is preferably used in view of the stability and viscosity of the modified epoxy resin aqueous dispersion.

  The compounding ratio of the amine compound (a) and the epoxy resin (b) is such that the carbonyl group concentration in the carbonyl group-containing modified epoxy resin is in the range of 0.1 to 3.5 mol / kg based on the resin solid content. It is preferable from the viewpoint of the corrosion resistance of the coating film obtained from the aqueous primer composition of the present invention, and more preferably in the range of 0.4 to 3 mol / kg.

  The carbonyl group-containing modified epoxy resin preferably has a weight average molecular weight in the range of 2,000 to 50,000, more preferably in the range of 5,000 to 20,000. When the weight average molecular weight is larger than 50,000, the viscosity becomes high and the production is difficult, and the finish of the coating film is uneasy. Further, when the weight average molecular weight is less than 5,000, sufficient water resistance may not be obtained.

  In addition, in this specification, the number average molecular weight and weight average molecular weight of resins other than the resin into which the cationic group is introduced are the retention time (retention capacity) measured using a gel permeation chromatograph (GPC), It is a value obtained by converting to the molecular weight of polystyrene by the retention time (retention capacity) of standard polystyrene having a known molecular weight measured under the same conditions. Specifically, "HLC8120GPC" (trade name, manufactured by Tosoh Corporation) is used as a gel permeation chromatograph, and "TSKgel G-4000HXL", "TSKgel G-3000HXL", " Four TSKgel G-2500HXL and TSKgel G-2000HXL (trade names, both manufactured by Tosoh Corporation) were used, a differential refractometer was used as a detector, and mobile phase: tetrahydrofuran, measurement temperature : Measured under conditions of 40 ° C. and flow rate: 1 mL / min.

  The number average molecular weight and the weight average molecular weight of the resin into which the cationic group is introduced are specifically determined by using “HLC-8120GPC” (trade name, manufactured by Tosoh Corporation) as a gel permeation chromatograph. The column used was a total of three “TSKgel Super-H3000” and two “TSKgel Super-H2500” (trade names, both manufactured by Tosoh Corp.), and the detector was a differential. Using a refractometer, it can be measured under the conditions of mobile phase: tetrahydrofuran (containing 0.5% by weight of triethanolamine), measurement temperature: 25 ° C., flow rate: 0.6 mL / min.

  In the present invention, the reaction between the amine compound (a) and the epoxy resin (b) can be carried out in the presence of an organic solvent. Although it does not specifically limit as an organic solvent, Well-known organic solvents, such as ester type | system | group, alcohol type | system | group, ether type | system | group, and a ketone type | system | group, can be used. The concentration of the reaction solution is preferably in the range of 50 to 90% by mass from the viewpoint that the reaction rate and the solvent remaining when the obtained resin is dispersed with water can be reduced, more preferably. Is in the range of 55-80% by mass. Moreover, it is preferable to make reaction temperature into the range of 40-160 degreeC from the point of reaction rate or a viscosity, More preferably, it exists in the range of 60-140 degreeC.

  The molecular weight of the carbonyl group-containing modified epoxy resin of the present invention can be adjusted by the blending ratio of the amine compound (a) and the epoxy resin (b). Also, amine compounds such as isophoronediamine, 2-ethylhexylamine and cyclohexylamine having two or more active hydrogens capable of reacting with an epoxy group, compounds having a phenolic hydroxyl group and dibasic acids such as terephthalic acid and adipic acid Etc. can be added to the reaction system of the amine compound (a) and the epoxy resin (b) and reacted to adjust the molecular weight of the carbonyl group-containing modified epoxy resin.

  The amine value of the carbonyl group-containing modified epoxy resin of the present invention is preferably in the range of 10 to 200 mg-KOH / g from the viewpoint of achieving both water dispersibility and water resistance when neutralized, more preferably It is in the range of 20 to 180 mg-KOH / g. The amine value in this specification means a value measured by a titration method defined in JIS K 7237.

  The epoxy equivalent of the carbonyl group-containing modified epoxy resin in the present invention is preferably greater than 1000. When the epoxy equivalent is 1000 or less, the storage stability of the aqueous primer composition of the present invention may be lowered.

  The carbonyl group-containing modified epoxy resin is dispersed in water or a medium containing water (hereinafter sometimes referred to as an aqueous medium) and used as an aqueous dispersion in the aqueous primer composition of the present invention. In the present specification, the aqueous dispersion includes one in which a carbonyl group-containing modified epoxy resin is dissolved in an aqueous medium. Examples of the medium containing water include a mixture of water and an organic solvent such as a water-soluble organic solvent. Water dispersion can be carried out by a conventionally known method without particular limitation. For example, a carbonyl group-containing modified epoxy resin is subjected to shearing force in the presence of an emulsifier to form fine particles in water or a medium containing water to form an aqueous dispersion. A method for obtaining a water dispersion by applying shearing force to a carbonyl group-containing modified epoxy resin into which a hydrophilic group such as an anionic group, a cationic group, or a nonionic group is introduced to form fine particles in an aqueous medium, Examples thereof include a method of applying a shearing force to the carbonyl group-containing modified epoxy resin having the hydrophilic group introduced therein in the presence of an emulsifier to form fine particles in an aqueous medium to obtain an aqueous dispersion.

  The emulsifier is not particularly limited, and an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier, an amphoteric emulsifier, a reactive emulsifier, and the like can be used.

  For example, alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate and sodium dodecyl sulfate, fatty acid salts, rosinates, alkyl sulfates, alkyl sulfosuccinates, α-olefin sulfonates, alkyl naphthalene sulfonates, polyoxyethylenes Anionic emulsifiers such as alkyl (aryl) sulfate ester salts; quaternary ammonium salts such as lauryl trialkyl ammonium salts, stearyl trialkyl ammonium salts, trialkyl benzyl ammonium salts, primary to tertiary amine salts, Cationic surfactants such as lauryl pyridinium salt, benzalkonium salt, benzethonium salt or laurylamine acetate; polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether Nonionic surfactants such as polyoxyethylene alkyl ester and polyoxyethylene sorbitan alkyl ester; amphoteric surfactants such as carboxybetaine type, sulfobetaine type, aminocarboxylic acid type, and imidazoline derivative type; Eleminol JS-2 (Sanyo Kasei) Industrial), Eleminol RS-30 (manufactured by Sanyo Chemical Industries), Latemuru S-180A (manufactured by Kao), Aqualon HS-05 (manufactured by Daiichi Kogyo Seiyaku), Aqualon RN-10 (manufactured by Daiichi Kogyo Seiyaku), Adekariso And reactive emulsifiers such as PSE-10N (Asahi Denka).

  In the present invention, the emulsifier is used in an amount of 100 parts by weight of the solid content of the carbonyl group-containing modified epoxy resin from the viewpoint of water stability when used as a film-forming component of the aqueous dispersion and the aqueous primer composition. The content is preferably in the range of 0 to 20 parts by mass, more preferably in the range of 0 to 15 parts by mass.

  In the present invention, one or more functional groups selected from an anionic group, a cationic group, and a nonionic group may be added to the carbonyl group-containing modified epoxy resin, and then dispersed in a medium containing water.

  Examples of imparting an anionic group include the following methods for imparting a carboxyl group. To a solution of a cyclic ether such as dioxane, a dialkyl ether of an oxyethylene chain such as glyme or diglyme, an aprotic organic solvent such as acetone, a carbonyl group-containing modified epoxy resin solution is added, and carboxylic anhydride is added. A carbonyl group-containing modified epoxy resin having a carboxyl group is obtained by raising the temperature to about 90 ° C. and reacting. Furthermore, if the carboxyl group is neutralized using a basic compound and then phase-reversed in an aqueous medium, an aqueous dispersion of a carbonyl group-containing modified epoxy resin can be obtained.

  The carboxylic anhydride may be an anhydride of a compound having two or more carboxyl groups in one molecule. For example, succinic anhydride, itaconic anhydride, maleic anhydride, citraconic anhydride, phthalic anhydride, trihydric anhydride A merit acid or the like can be used. In addition, as the basic compound, amines, alkaline earth metal hydroxides and / or alkali metal hydroxides can be used.

  As an example of imparting a cationic group, a method of introducing a basic amino group into an epoxy group of a carbonyl group-containing modified epoxy resin, neutralizing with an acid, and dispersing in a medium containing water can be mentioned. Specifically, a carbonyl group-containing modified epoxy resin and an amino group-containing compound are reacted to give an amino group, and then neutralized using an acidic compound such as a carboxylic acid.

  Among the amino group-containing compounds, examples of the primary amino group-containing compound include monoethanolamine, propanolamine, hydroxyethylaminopropylamine, diethylenetriamine, 2-ethylhexylamine, cyclohexylamine, and triethylenetetramine. . Examples of secondary amino group-containing compounds include diethylamine, diisopropylamine, diethanolamine, di (2-hydroxypropyl) amine, monomethylaminoethanol, monoethylaminoethanol and the like. The above amino group-containing compounds can be used alone or in combination of two or more.

  In addition, the amine compound (a) used in the production of the carbonyl group-containing modified epoxy resin or the amino group derived from the amine compound used for adjusting the molecular weight of the resin is neutralized with an acidic compound, and then the carbonyl group The contained modified epoxy resin may be dispersed in an aqueous medium to obtain an aqueous dispersion.

  In the method in which the amino group contained in the carbonyl group-containing modified epoxy resin is neutralized with an acidic compound and dispersed in water, the acidic compound includes, for example, formic acid, acetic acid, lactic acid, phosphoric acid, and organic phosphoric acid. Can do. These acidic compounds may be mixed with a carbonyl group-containing modified epoxy resin to neutralize amino groups and then dispersed while adding an aqueous medium, or a mixture with an aqueous medium may be mixed with a carbonyl group-containing modified epoxy resin. You may neutralize and disperse | distribute, mixing.

  Specific examples of the method for imparting a nonionic group include a method of reacting an amine compound (a), an epoxy resin (b), and a polyoxyalkyleneamine compound in the production of a carbonyl group-containing modified epoxy resin. be able to. Examples of the polyoxyalkyleneamine compound include a compound represented by the following formula having an amino group capable of reacting with an epoxy group.

(Wherein R ¹ represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, m is an integer of 2 to 220, preferably 5 to 180, and n is 2) An integer of ˜3, preferably 2, where the m oxyalkylene units (CnH _2n O) may be the same or different from each other.)
These polyoxyalkylene compounds are preferably used in the range of 1 to 25% by mass, and more preferably 3 to 15% by mass in the solid content of the carbonyl group-containing modified epoxy resin from the viewpoint of achieving both water dispersibility and water resistance. preferable.

  As another method for imparting a nonionic group, specifically, in the production of a carbonyl group-containing modified epoxy resin, an amine compound (a), an epoxy resin (b), and a polymer having an unsaturated group capable of Michael addition reaction are used. Examples thereof include a method of reacting with an oxyalkylene unsaturated compound. Examples of the polyoxyalkylene unsaturated compound include compounds represented by the following formula.

(In the formula, R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is an integer of 2 to 220, preferably 5 to 180, and n is an integer of 2 to 3, preferably 2. And m oxyalkylene units (CnH _2n O) may be the same or different from each other). Specific examples thereof include polyethylene glycol acrylate, polypropylene glycol acrylate, methoxy polyethylene glycol acrylate, ethoxy polyethylene glycol acrylate, and the like.

  In the present invention, after the amine compound (a) and the epoxy resin (b) are reacted to obtain a carbonyl group-containing modified epoxy resin, one or more functional groups selected from an anionic group, a cationic group and a nonionic group From the anionic group, cationic group and nonionic group by simultaneously carrying out the reaction between the amine compound (a) and the epoxy resin (b) and the reaction for imparting the functional group. A carbonyl group-containing modified epoxy resin having one or more selected functional groups may be obtained.

  Further, the concentration of the aqueous dispersion of the carbonyl group-containing modified epoxy resin is preferably in the range of 10 to 50% by mass, more preferably in the range of 20 to 45% by mass as the solid content from the viewpoint of stability and viscosity. Is within.

  In the present invention, when a nonionic group is introduced, an aqueous dispersion can be obtained in an aqueous medium as it is, but if necessary, an amino group contained in the resin is neutralized with an acidic compound. An aqueous dispersion can also be obtained in an aqueous medium.

[Crosslinking agent (B)]
The crosslinking agent (B) in the present invention is used for imparting a crosslinked structure to the primer coating film obtained after baking to improve water resistance or to improve physical properties. Examples of the crosslinking agent include amino resins, polyaldehyde compounds, phenol resins, epoxy compounds, isocyanate compounds, blocked isocyanate compounds, metal compounds (metal salts, metal complexes, metal oxides, metal hydroxides, etc.) ), Silicate compounds, hydrazide compounds, semicarbazide compounds and the like.

  Examples of the amino resin include methylolated amino resins obtained by a reaction of an amino component such as melamine, urea, benzoguanamine, acetogranamamine, sterogtanamine, spiroguanamine, and dicyandiamide with aldehydes. Examples of aldehydes used in the above reaction include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde. Moreover, what etherified the said methylolated amino resin with suitable alcohol can also be used as an amino resin. Examples of alcohols used for etherification include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-ethylbutanol, 2? Examples thereof include ethyl hexanol.

  The polyaldehyde compound is a compound having at least two aldehyde groups in one molecule, and specific examples thereof include glyoxal and glutaraldehyde.

  The phenol resin is, for example, a methylol group of a methylolated phenol resin obtained by introducing a methylol group by heating and condensing a phenol component and an aldehyde in the presence of a reaction catalyst. Examples thereof include a resole type phenol resin obtained by alkylating a part or all with an alcohol. In the production of the resole type phenol resin, a bifunctional phenol compound, a trifunctional phenol compound, a tetrafunctional or higher phenol compound, or the like can be used as the phenol component as a starting material.

  Examples of the phenol compound include, for example, o-cresol, p-cresol, p-tert-butylphenol, p-ethylphenol, 2,3-xylenol, and 2,5-xylenol. Examples of the trifunctional phenol compound include carboxylic acid, m-cresol, m-ethylphenol, 3,5-xylenol, m-methoxyphenol, and the like. Bisphenol A, bisphenol F and the like. Among them, in order to improve scratch resistance, it is preferable to use a trifunctional or higher functional phenol compound, in particular, carboxylic acid and / or m-cresol. These phenol compounds may be used alone or in combination of two or more.

  Examples of the aldehydes used for the production of the phenol resin include formaldehyde, paraformaldehyde, trioxane and the like, and they can be used alone or in combination of two or more.

  As the alcohol used for alkyl etherifying a part of the methylol group of the methylolated phenol resin, a monohydric alcohol having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, is preferably used. be able to. Suitable monohydric alcohols include methanol, ethanol, n-propanol, n-butanol, isobutanol and the like.

  The phenol resin has an average of 0.5 or more, preferably 0.6 to 3.0, alkoxymethyl groups per benzene nucleus from the viewpoint of reactivity with the carbonyl group-containing modified epoxy resin of the present invention. Things are suitable.

  The epoxy compound is a compound having at least two epoxy groups in one molecule, and typical examples thereof include ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin. Diglycidyl ether, glycerin triglycidyl ether, diglycerin triglycidyl ether, sorbitol polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A diglycidyl ether, phenol novolac polyglycidyl ether, cresol novolac polyglycidyl ether, etc. Polyglycidyl ethers of polyhydric alcohols or polyhydric phenols; glycidyl esters and glycidyl ethers of p-oxybenzoic acid Polyglycidyl esters of polycarboxylic acids such as phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester or (meth) acrylic acid glycidyl ester copolymer; polyepoxy compounds containing nitrogen-containing heterocycles such as hydantoin rings An epoxy resin which is an adduct of a compound having two or more epoxy groups in one molecule and a polyhydric alcohol, polyhydric phenol or polybasic acid; a modified epoxy resin such as a fatty acid-modified epoxy resin or an amine-modified epoxy resin A vinyl polymer having an epoxy group in the side chain, and the like. When the epoxy compound is blended, the amount of the epoxy group in the epoxy compound is 0.05 with respect to a total of 1 mol of the carboxyl group and hydroxyl group contained in the carbonyl group-containing modified epoxy resin (A) of the present invention. It is desirable that the content is adjusted to be in the range of ˜3 mol, preferably 0.1 to 2 mol.

  The isocyanate compound is a compound having two or more isocyanate groups in one molecule, and those conventionally used for the production of polyurethane can be used. Examples thereof include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates and derivatives of these polyisocyanates.

  Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, and 3-isocyanatomethyl- 3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 4,4'-methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexanediisocyanate Methyl-2,6-cyclohexanediisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane (common name: hydrogenated xylylene diisocyanate) or a mixture thereof, norbornane diisocyanate Alicyclic diisocyanates such as, for example, 1,3,5-triisocyanatocyclohexane, 1, , 5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 2- (3-isocyanatopropyl) -2 , 6-Di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 3- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 6- (2-isocyanatoethyl) -2-isocyanate Natomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyana Propyl) -bicyclo (2.2.1) -heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, etc. And alicyclic triisocyanates.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, and 1,2-propylene diisocyanate. -To, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethyl Aliphatic diisocyanates such as hexamethylene diisocyanate and 2,6-diisocyanatomethyl caproate, such as lysine ester triisocyanate, 1,4,8-triisocyanatooctane, 1 , 6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, 5,7 aliphatic such as trimethyl-1,8-diisocyanato-5-isocyanatomethyl octane Toriisoshiane - DOO, and the like.

  Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω′-diisocyanato-1,4-diethylbenzene, 1,3- or 1, Aromatic aliphatic diisocyanates such as 4-bis (1-isocyanato-1-methylethyl) benzene (common name: tetramethylxylylene diisocyanate) or mixtures thereof, for example 1,3,5-triisocyanate Examples thereof include araliphatic triisocyanates such as methylbenzene.

  Examples of aromatic polyisocyanates include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, and 1,5-naphthalenediisocyanate. 2,4'- or 4,4'-diphenylmethane diisocyanate or mixtures thereof, 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, 4,4'-toluidine diisocyanate -Aromatic diisocyanates such as 4,4'-diphenyl ether diisocyanate, for example, triphenylmethane-4,4 ', 4' ''-triisocyanate, 1,3,5-triisocyanate Aromatic triisocyanates such as natobenzene, 2,4,6-triisocyanatotoluene, for example, 4,4′-diphenylmethane-2,2 ′, 5,5′- Toraisoshiane - aromatic tetracarboxylic diisocyanate such bets - bets, and the like.

  Examples of the polyisocyanate derivatives include dimer, trimer, biuret, allophanate, carbodiimide, uretdione, uretoimine, isocyanurate, oxadiazine trione, polymethylene polyphenyl of the above polyisocyanate compound. Examples thereof include polyisocyanate (crude MDI, polymeric MDI) and crude product of tolylene diisocyanate (crude TDI).

  As the above-mentioned isocyanate compound, a compound obtained by modifying a part of the isocyanate group with a compound containing 1 to 5 active hydrogens such as a hydroxyl group or an amino group may be used as necessary.

  Said isocyanate compound may be used independently and may be used together 2 or more types.

  The blocked isocyanate compound as a cross-linking agent is a compound in which the isocyanate group of the isocyanate compound is blocked with a blocking agent.

  The reaction between the isocyanate compound and the blocking agent can be carried out under known conditions. Moreover, it is preferable that the ratio of both components is set so that a slightly excessive amount of the blocking agent is formed with respect to all isocyanate groups in the isocyanate compound so that the isocyanate group does not remain. When blocking (reacting the blocking agent), a solvent can be added as necessary. As the solvent used for the blocking reaction, those which are not reactive with isocyanate groups are preferable, for example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, and N-methylpyrrolidone (NMP). Can be mentioned.

  The blocking agent is a compound that blocks the isocyanate group. When the blocked isocyanate group is heated to, for example, 100 ° C. or higher, preferably 130 ° C. or higher, the blocking agent is dissociated to regenerate the isocyanate group and can be easily reacted with a hydroxyl group or the like.

  Examples of the blocking agent include phenols such as phenol and cresol; lactams such as ε-caprolactam and δ-valerolactam; aliphatics such as methanol, ethanol, propyl alcohol, butyl alcohol, and lauryl alcohol; ethylene glycol Ether systems such as monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether; benzyl alcohol; glycolic acid esters such as methyl glycolate and ethyl glycolate; lactic acid, methyl lactate, ethyl lactate, butyl lactate, etc. Lactic acid esters; alcoholic systems such as methylol urea and diacetone alcohol; acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzof Oximes such as enone oxime and cyclohexane oxime; active methylenes such as diethyl malonate, ethyl acetoacetate, methyl acetoacetate and acetylacetone; butyl mercaptan, t-butyl mercaptan, hexyl mercaptan, t-dodecyl mercaptan, thiophenol, ethylthiophenol Mercaptans such as acetanilide, acetanisidide, acid amides such as methacrylamide, acetic acid amide and benzamide; imides such as phthalimide and maleic imide; amines such as diphenylamine, phenylnaphthylamine, carbazole, aniline, naphthylamine and butylamine Systems; imidazole systems such as imidazole and 2-ethylimidazole; urea systems such as urea, thiourea, ethyleneurea and diphenylurea; N Carbamate esters such as phenyl phenylcarbamate; Imines such as ethyleneimine and propyleneimine; Sulphites such as sodium bisulfite and potassium bisulfite; 3,5-dimethylpyrazole, 3-methylpyrazole, Pyrazole compounds such as 4-nitro-3,5-dimethylpyrazole and 4-bromo-3,5-dimethylpyrazole can be exemplified. The above blocking agents can be used alone or in combination of two or more.

  The blocked isocyanate compounds can be used alone or in combination of two or more. When the blocked isocyanate compound is blended, the amount of the blocked isocyanate group is usually 0.05 with respect to 1 mol of the hydroxyl group contained in the carbonyl group-containing modified epoxy resin (A) of the present invention. It is desirable that the content is adjusted to be in the range of ˜3 mol, preferably 0.1 to 2 mol.

  As the hydrazide compound or semicarbazide compound, for example, a compound having two or more hydrazide groups and / or semicarbazide groups in one molecule can be preferably used. For example, saturated fatty acid dihydrazides having 2 to 18 carbon atoms such as succinic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, etc .; maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide Monoolefinically unsaturated dicarboxylic acid dihydrazide, phthalic acid, terephthalic acid or isophthalic acid dihydrazide, and pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotrihydrazide, citric acid trihydrazide, 1,2,4-benzenetrihydrazide , Ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydrazide, two or more carboxylic acid lower alkyl ester groups in one molecule. A polyhydrazide compound such as polyhydrazide obtained by reacting a low polymer having hydrazine or a hydrazine hydrate (hydrazine hydride) (Japanese Patent Publication No. 52-22878), carbonic acid dihydrazide; hexamethylene diisocyanate and isophorone Examples of the polyisocyanate compound containing diisocyanate and polyisocyanate compound obtained by reacting hydrazine and monoalkyl-substituted hydrazine with diisocyanate such as diisocyanate and polyisocyanate compound derived therefrom. Obtained from the reaction of a polyhydrazide compound obtained by reacting a dihydrazide compound or a polyhydrazide compound of the polyhydrazide compound, a polyisocyanate compound with a polyether or polyol having active hydrogen such as polyethylene glycol monoalkyl ethers. A polysemicarbazide compound obtained by reacting an isocyanate group in the modified polyisocyanate compound with hydrazine or a monoalkyl-substituted hydrazine, and reacting the above-exemplified dihydrazide or polyhydrazide with the isocyanate group of the modified polyisocyanate compound The polyhydrazide compound etc. which are made to obtain are mentioned, These can be used individually or in mixture as needed.

  The hydrazine derivative generally has a total of 0.01 to 2 mol of hydrazide group and semicarbazide group contained in the hydrazine derivative with respect to 1 mol of carbonyl group of the carbonyl group-containing modified epoxy resin (A). It is preferably from the range of 0.1 to 1.5 mol from the viewpoint of low temperature curability.

[Anti-rust pigment (C)]
As the rust preventive pigment (C), chromate, vanadium compound, silicon-containing compound, phosphoric acid compound, phosphite pigment, calcium compound, aluminum oxide, zinc oxide, zirconic acid, zirconic acid compound, What mixed any 1 type or 2 types or more, such as a molybdate compound, can be used. Among these, non-chromium rust preventive pigments other than chromate are preferable from the viewpoint of human health and environmental protection. As the non-chromium rust preventive pigment, for example, a mixture of a rust preventive pigment containing a vanadium compound (c1), a silicon-containing compound (c2) and a phosphate compound (c3) is particularly preferable from the viewpoint of corrosion resistance.

  The vanadium compound (c1) is at least one vanadium compound selected from vanadium pentoxide, calcium vanadate, and ammonium metavanadate. In particular, vanadium pentoxide and calcium vanadate are excellent in elution of pentavalent vanadium ions into water, and the pentavalent vanadium ions released from the vanadium compound (c1) react with the material metal, It effectively works to improve corrosion resistance by reacting with ions from the rust preventive pigment mixture.

The silicon-containing compound (c2) contains at least one compound selected from metal silicate salts, silica fine particles, and metal ion exchanged silica fine particles.
The silicate metal salt is a salt made of silicon dioxide and a metal oxide, and may be any of orthosilicate, polysilicate and the like. Examples of silicates include zinc silicate, aluminum silicate, aluminum orthosilicate, hydrated aluminum silicate, calcium aluminum silicate, sodium aluminum silicate, beryllium aluminum silicate, sodium silicate, calcium orthosilicate, calcium metasilicate, sodium calcium silicate, and silicic acid. Zirconium, magnesium orthosilicate, magnesium metasilicate, magnesium calcium silicate, manganese silicate, barium silicate, olivine, garnet, tortovite, cyllite, benitoite, neptunite, nymphite, turquoise, quartzite, barracite, tosen Stones, zonotorite, talc, gyoganite, aluminosilicate, borosilicate, beryllosilicate, cholite, fluorite and the like. As the metal silicate, calcium orthosilicate and calcium metasilicate are particularly preferable.

The silica fine particles can be used without particular limitation as long as they are silica fine particles, such as silica fine powder with an untreated surface, silica fine powder with a surface treated with an organic material, calcium ion-exchanged silica fine particles, organic solvent-dispersed colloidal silica, etc. Can be mentioned. Examples of the silica fine particles whose surface is not treated or treated with an organic substance include silica fine powder having an average particle size of 0.5 to 15 μm, preferably 1 to 10 μm, and organic solvent-dispersible colloidal silica. As the fine silica powder, those having an oil absorption of 30 to 350 ml / 100 g, preferably 30 to 150 ml / 100 g can be suitably used, and as commercially available products, silicia 710, silicia 740, silicia 550, Examples include Aerosil R972 (all of which are manufactured by Fuji Silysia Chemical Co., Ltd.), Mizukacil P-73 (manufactured by Mizusawa Chemical Co., Ltd.), Gasil 200DF (manufactured by Crossfield).
The organic solvent-dispersible colloidal silica is also referred to as an organosilica sol, in which silica fine particles having a particle size of about 5 to 120 nm are stably dispersed in an organic solvent such as alcohols, glycols, and ethers. In addition, examples of commercially available products include OSCAL series (manufactured by Catalyst Kasei Co., Ltd.), organosol (manufactured by Nissan Chemical Co., Ltd.), and the like.

  The metal ion exchanged silica fine particles are silica fine particles in which metal ions are introduced into a fine porous silica carrier by ion exchange. Specifically, it is a silica fine particle into which calcium or magnesium is introduced. For example, as commercially available products of calcium ion-exchanged silica, SHIELDEX (Shieldex, registered trademark) C303, SHIELDEXAC-3, SHIELDEXC-5 (all of which are manufactured by WR Grace & Co.) and the like can be mentioned. Can do.

  Examples of the phosphate compound (c3) include calcium phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium phosphate phosphate, zinc phosphate, aluminum phosphate, magnesium phosphate, phosphorus Phosphate metal salts such as zinc oxyhydrogen, aluminum phosphate, magnesium phosphate, aluminum hydrogen phosphate, magnesium hydrogen phosphate, magnesium ammonium phosphate, aluminum dihydrogen triphosphate, phosphoric acid, organic phosphate compounds, etc. Can be mentioned. Phosphate ions released from the phosphoric acid compound (c3), metal ions such as Ca, Zn, Al or Mg effectively work to improve the corrosion resistance.

In the aqueous primer composition of the present invention, the vanadium compound (c1), the silicon-containing compound (c2), and the total solid content of 100 parts by mass of the carbonyl group-containing modified epoxy resin (A) and the crosslinking agent (B) The phosphoric acid compound (c3) is preferably within the following range.
Vanadium compound (c1): 3 to 50 parts by mass, preferably 5 to 30 parts by mass,
Silicon-containing compound (c2): 3 to 50 parts by mass, preferably 5 to 30 parts by mass,
Phosphoric acid compound (c3): 3 to 50 parts by mass, preferably 5 to 30 parts by mass.

  In the primer composition of the present invention, the total amount of (c1), (c2) and (c3) is 100 parts by mass of the total solid content of the carbonyl group-containing modified epoxy resin (A) and the crosslinking agent (B). It is suitable from a corrosion-resistant viewpoint that it is 10-150 mass parts, Preferably it is 15-90 mass parts.

  Further, the vanadium compound (c1), the silicon-containing compound (c2) and the phosphorus constituting the rust preventive pigment mixture (C) blended with respect to 100 parts by mass of the total solid content of the resin (A) and the crosslinking agent (B). A mixture of mass parts of the acid compound (c3) in each quantitative range was added to 10000 parts by mass of a 5% by mass sodium chloride aqueous solution at 25 ° C., stirred for 6 hours, and allowed to stand at 25 ° C. for 48 hours. The pH of the filtrate obtained by filtering the supernatant is 3-10, preferably 4-8, so that the vanadium compound (c1), the silica fine particles (c2) and the phosphate compound (c3) are soluble in water and rust-proof. It is suitable from the viewpoint of the reactivity between the pigment solution and the metal plate, and is preferably in this range from the viewpoint of corrosion resistance.

  That is, the above-mentioned filtrate for pH measurement has a silicon content of any one of 3 to 50 parts by mass of the vanadium compound (c1) with respect to 10000 parts by mass of a 5% by mass sodium chloride aqueous solution at 25 ° C. Filtrate of a solution obtained by adding and dissolving any amount within a range of 3 to 50 parts by mass of compound (c2) and any amount within a range of 3 to 50 parts by mass of phosphoric acid compound (c3) It is.

  The aqueous primer composition of the present invention includes, in addition to the carbonyl group-containing modified epoxy resin (A), the crosslinking agent (B), the rust preventive pigment (C), and a curing catalyst blended as necessary, in the paint field. Usable coloring pigments, extender pigments, UV absorbers, UV stabilizers, organic solvents; additives such as antisettling agents, antifoaming agents, coating surface modifiers, and the like can be blended as necessary.

  Examples of the coloring pigment include organic coloring pigments such as cyanine blue, cyaning green, organic red pigments such as azo and quinacridone; inorganic coloring such as titanium white, titanium erotic, bengara, carbon black, and various fired pigments. A pigment can be mentioned, and among these, titanium white can be preferably used.

  Examples of the extender pigment include talc, clay, silica, mica, alumina, calcium carbonate, and barium sulfate.

  Examples of the ultraviolet absorber include 2- (2-hydroxy-3,5-di-tert-amylphenyl) -2H-benzotriazole, isooctyl-3- (3- (2H-benzotriazol-2-yl). ) -5-tert-butyl-4-hydroxyphenylpropionate, 2- [2-hydroxy-3,5-di (1,1-dimethylbenzidine) phenyl] -2H-benzotriazole, 2- [2- Hydroxy-3-dimethylbenzyl-5- (1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole, methyl-3- [3-t-butyl-5- (2H-benzotriazole) -2-triyl) -4-hydroxyphenyl] propionate / condensate with polyethylene glycol 300 and the like; 2- [4- (2 Hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl-4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine and the like; ethanediamide-N- (2- Succinic acid such as ethoxyphenyl) -N ′-(2-ethylphenyl)-(oxalic amide), ethanediamide-N- (2-ethoxyphenyl) -N ′-(4-isododecylphenyl)-(oxalic amide) Examples include anilide derivatives.

  Examples of the ultraviolet light stabilizer include hindered amine compounds, hindered phenol compounds; CHIMASORB 944, TINUVIN 144, TINUVIN 292, TINUVIN 770, IRGANOX 1010, IRGANOX 1098 It is a product of Chemicals Co., Ltd.).

  By blending a UV absorber or UV stabilizer into the aqueous primer composition, it is possible to suppress deterioration of the primer surface due to light passing through the upper coating film and reaching the primer coating film surface. It is possible to prevent delamination between the primer coating film and the upper coating film due to deterioration of the primer coating film surface, and maintain excellent corrosion resistance.

  The organic solvent that can be blended in the aqueous primer composition of the present invention is blended as necessary to improve the paintability of the composition of the present invention, and includes a carbonyl group-containing modified epoxy resin (A) and a cross-linking. Agents that can dissolve or disperse the agent (B) can be used. Specifically, for example, hydrocarbon solvents such as toluene, xylene, high-boiling petroleum hydrocarbons, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone. Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, methanol, ethanol, isopropanol, butanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, The Mention may be made of alcohol-based solvents such as Chi glycol monobutyl ether, which may be used alone or in combination of two or more.

  The aqueous primer composition of the present invention is coated on a metal plate, and the formed coating film exhibits excellent workability and processed part corrosion resistance. The reason for this is that in the carbonyl group-containing modified epoxy resin (A), flexibility is imparted by incorporating the structure of the amine compound (a) having a carbonyl group next to the rigid epoxy resin skeleton, Further, it is considered that the highly polar amide bond or carbonyl group contained in the amine compound (a) improved the cohesive strength of the resin, leading to excellent processability. In addition to the inherent corrosion resistance of the carbonyl group-containing modified epoxy resin (A), the highly polar amide bond and carbonyl group contained in the resin may contribute to adhesion to the metal substrate. I think it led to excellent corrosion resistance.

  The aqueous primer composition of the present invention can be applied to a metal plate and cured to obtain a coated metal plate. As the metal plate to be coated, cold rolled steel plate, hot dip galvanized steel plate, electrogalvanized steel plate, iron-zinc alloy plated steel plate (galvanyl steel plate), aluminum-zinc alloy plated steel plate (containing about 55% aluminum in the alloy) Metal plate such as “galvanium steel plate”, “galfan” containing about 5% aluminum in the alloy), nickel-zinc alloy plated steel plate, stainless steel plate, aluminum plate, copper plate, copper plated steel plate, tin plated steel plate, etc. The surface of the metal plate may be subjected to chemical conversion treatment. Examples of the chemical conversion treatment include phosphate treatment such as zinc phosphate treatment and iron phosphate treatment, composite oxide film treatment, chromium phosphate treatment, and chromate treatment.

  The composition of the present invention can be coated on the metal plate by a known method such as a roll coating method, a curtain flow coating method, a spray method, a brush coating method, or a dipping method. Although the cured film thickness of the coating film obtained from this invention composition is not specifically limited, Usually, 2-10 micrometers, Preferably it is used in the range of 3-6 micrometers. Curing of the coating film may be appropriately set according to the type of resin used, and when continuously baking what is coated by a coil coating method or the like, for example, the material reaching maximum temperature is 160 to 250. It is baked for 15 to 60 seconds under the condition of ° C, preferably 180 to 230 ° C. In the case of baking in a batch system, it can be carried out by baking at 80 to 200 ° C. for 10 to 30 minutes. In the case of a combination that does not particularly require heating for the crosslinking reaction in the coating film forming process such as when an unblocked isocyanate compound is used as the crosslinking agent (B), it is dried at room temperature according to a conventional method. Can be cured.

  A coated metal plate provided with a coating film made of the aqueous primer composition of the present invention on a metal plate which may be subjected to chemical conversion treatment can be used as it is, but is further known on this coating film. It is also possible to provide a top coat by applying a top coat.

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples. The present invention is not limited to the following examples. Hereinafter, “parts” and “%” are based on mass.

Production of amine compound (a) [Production Example 1]
Air in a 1 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 338.4 g of diacetone acrylamide, 180.2 g of deionized water, and 352.6 g of N-ethylethylenediamine were added. Then, the mixture was stirred, heated to 80 ° C. and held at 80 ° C. for 3 hours. Next, while reducing the pressure to about 100 mmHg, the temperature was maintained at 60 to 80 ° C. for 2 hours, and about 240 g of a mixture of water and unreacted N-ethylethylenediamine was removed azeotropically. Thereafter, 200 g of water was added and maintained at 80 ° C. for 1 hour, and then maintained at 60 to 80 ° C. for 1.5 hours while reducing the pressure to about 100 mmHg to remove azeotropically about 200 g of the mixture of water and N-ethylethylenediamine. Repeated twice. Then, hold at 60-80 ° C. for 1.5 hours while reducing the pressure to about 10 mmHg, remove the remaining water and N-ethylethylenediamine to remove two secondary amino groups, and further add a Michael having a carbonyl group An amine compound (a1) as a reaction product was obtained. In the ¹ H-NMR measurement of the product using deuterated chloroform solvent, since 6.19 to 6.23 ppm peak due to diacetone acrylamide is not observed, no unreacted diacetone acrylamide remains. confirmed.

  0.1 g of the amine compound (a1) obtained in a 100 mL Erlenmeyer flask was weighed, 30 mL of acetic acid was added and dissolved, and then an indicator (a solution of 0.3 g of alphazulin G dissolved in 100 mL of glacial acetic acid and Timol Blue- 0.2 mL of a solution obtained by dissolving 1.5 g in methanol was added, and titrated with 0.1N perchloric acid (acetic acid solution) until the solution changed from green to red. As a result, the amine value of the amine compound (a1) was 426 mg-KOH / g.

[Production Example 2]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 507.7 g of diacetone acrylamide, 270.3 g of water and 438.8 g of butylamine were added and stirred. The temperature was raised to 0 ° C. and kept at 80 ° C. for 2 hours. Next, the pressure was reduced to about 100 mmHg and maintained at 60 to 80 ° C. for 1.5 hours, and about 430 g of a mixture of water and unreacted butylamine was removed azeotropically. After that, an operation for attaching a moisture determination receiver to the flask, adding 270 g of water, raising the temperature to 105 ° C., holding at 103 to 105 ° C. under normal pressure for 1 hour, and azeotropically removing about 200 g of the mixture of water and butylamine twice. Repeated. Next, while maintaining the pressure at 60-80 ° C for 1.5 hours while reducing the pressure to about 10 mmHg, the remaining water and butylamine are removed to have one secondary amino group in one molecule, and further a Michael having a carbonyl group An amine compound (a2) as an addition reaction product was obtained. In the ¹ H-NMR measurement of the product using deuterated chloroform solvent, since 6.19 to 6.23 ppm peak due to diacetone acrylamide is not observed, no unreacted diacetone acrylamide remains. confirmed. The amine value of the obtained amine compound (a2) was 230 mg-KOH / g.

[Production Example 3]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 507.7 g of diacetone acrylamide, 270.3 g of water, and 366.5 g of 2-aminoethanol were added and stirred. The temperature was raised to 80 ° C. and held at 80 ° C. for 2 hours. Next, thin film distillation was performed on a wall surface at a reduced pressure of 5 mmHg and 100 ° C. using a thin film distillation apparatus (Tokyo Rika Kikai Co., Ltd., model: MF-10A, evaporation area 0.04 m ² ), and water and unreacted 2- The aminoethanol mixture was removed. Thereafter, air in a 2 L flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet was replaced with nitrogen, and about 720 g of reaction product was obtained by removing unreacted 2-aminoethanol by thin-film distillation. 500 g of water was added, the temperature was raised to 105 ° C., and the ketimine was hydrolyzed by maintaining at normal pressure at 103 to 105 ° C. for 1 hour. Furthermore, thin film distillation is performed on a wall at 100 ° C. under reduced pressure of 5 mmHg to remove a mixture of 2-aminoethanol formed by hydrolysis of water and ketimine, so that one secondary amino group per molecule and one hydroxyl group Thus, an amine compound (a3) which is a Michael addition reaction product having one carbonyl group and a carbonyl group was obtained. In the ¹ H-NMR measurement of the product using deuterated chloroform solvent, since 6.19 to 6.23 ppm peak due to diacetone acrylamide is not observed, no unreacted diacetone acrylamide remains. confirmed. The amine value of the obtained amine compound (a3) was 255 mg-KOH / g.

Production of carbonyl group-containing modified epoxy resin (A) and aqueous dispersion thereof [Production Example 4]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and “jER828” (trade name, manufactured by Japan Epoxy Resins Co., Ltd., bisphenol A type epoxy resin) 152 0.0 g and 281.1 g of propylene glycol monomethyl ether were added and stirred, and the mixture was heated to 100 ° C. and dissolved. Thereafter, a mixture of 28.1 g of 2-ethylhexylamine and 57.5 g of “Safphonamine L-100” (trade name, manufactured by Huntsman Corporation, polyoxyalkyleneamine compound) was added and held at 100 ° C. for 2 hours. Thereafter, 19.3 g of the amine compound (a1) and 24.2 g of the amine compound (a2) were added, the temperature was raised to 120 ° C. and held at 120 ° C. for 7.5 hours, and the carbonyl group-containing modified epoxy resin (A1) A solution was obtained. Thereafter, a mixture of 15.8 g of acetic acid, 8.1 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1200 g of water, about 980 g was removed while azeotropically evaporating the solvent and water under reduced pressure, diluted with water so that the heating residue was about 30%, and the carbonyl group concentration in the resin solids was reduced to 0. An aqueous dispersion (AD1) of a carbonyl group-containing modified epoxy resin (A1) of 62 mol / Kg was obtained. The amine value of this resin was 105 mg-KOH / g, and the weight average molecular weight was about 11,000.

[Production Example 5]
Air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 152.0 g of “jER828” and 282.9 g of propylene glycol monomethyl ether were added and stirred until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 32.0 g of 2-ethylhexylamine and 56.0 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours, and then 4.1 g of amine compound (a1) and amine compound (a2) Was heated to 120 ° C. and held at 120 ° C. for 7.5 hours to obtain a solution of a carbonyl group-containing modified epoxy resin (A2). did. Thereafter, a mixture of 14.9 g of acetic acid, 7.6 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1200 g of water, about 980 g was removed while azeotropically evaporating the solvent and water under reduced pressure, diluted with water so that the heating residue was about 30%, and the carbonyl group concentration in the resin solids was reduced to 0. An aqueous dispersion (AD2) of a carbonyl group-containing modified epoxy resin (A2) of 62 mol / Kg was obtained. The amine value of this resin was 98 mg-KOH / g, and the weight average molecular weight was about 7200.

[Production Example 6]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 145.9 g of “jER828” and 267.4 g of propylene glycol monomethyl ether were added and stirred to 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 25.2 g of 2-ethylhexylamine and 54.4 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours, and then 26.4 g of amine compound (a1) and amine compound (a2) Was added and heated to 120 ° C. and held at 120 ° C. for 7.5 hours to obtain a solution of a carbonyl group-containing modified epoxy resin (A3). Thereafter, a mixture of 15.6 g of acetic acid, 8.0 g of 85% phosphoric acid and 100.0 g of water was added to the solution. Further, after adding 1150 g of water, about 950 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%. An aqueous dispersion (AD3) of a carbonyl group-containing modified epoxy resin (A3) of 62 mol / Kg was obtained. The amine value of this resin was 109 mg-KOH / g, and the weight average molecular weight was about 22,000.

[Production Example 7]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 152.0 g of “jER828” and 271.9 g of propylene glycol monomethyl ether were added and stirred until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 35.5 g of 2-ethylhexylamine and 55.0 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours, and then 5.1 g of amine compound (a1) and amine compound (a2) 24.2 g was added, and the temperature was raised to 120 ° C. and maintained at 120 ° C. for 7.5 hours to obtain a solution of a carbonyl group-containing modified epoxy resin (A4). Thereafter, a mixture of 14.1 g of acetic acid, 7.2 g of 85% phosphoric acid and 100.0 g of water was added to the solution. Further, after adding 1150 g of water, about 950 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%. An aqueous dispersion (AD4) of a carbonyl group-containing modified epoxy resin (A4) of 45 mol / Kg was obtained. The amine value of this resin was 97 mg-KOH / g, and the weight average molecular weight was about 10,000.

[Production Example 8]
Air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, 145.9 g of “jER828” and 276.7 g of propylene glycol monomethyl ether were added, and the mixture was stirred until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 20.2 g of 2-ethylhexylamine and 55.2 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours, and then 32.1 g of amine compound (a1) and amine compound (a2) 23.3 g was added, the temperature was raised to 120 ° C. and maintained at 120 ° C. for 7.5 hours to obtain a solution of a carbonyl group-containing modified epoxy resin (A5). Thereafter, a mixture of 16.7 g of acetic acid, 8.6 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1200 g of water, about 1000 g is removed while azeotropically evaporating the solvent and water under reduced pressure, diluted with water so that the heating residue is about 30%, and the carbonyl group concentration in the resin solids is reduced to 0. An aqueous dispersion (AD5) of a carbonyl group-containing modified epoxy resin (A5) at 80 mol / Kg was obtained. The amine value of this resin was 113 mg-KOH / g, and the weight average molecular weight was about 12000.

[Production Example 9]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and “jER1001” (trade name, manufactured by Japan Epoxy Resins Co., Ltd., bisphenol A type epoxy resin) 176 .4 g and propylene glycol monomethyl ether 271.0 g were added and stirred, and the mixture was heated to 100 ° C. and dissolved. Thereafter, a mixture of 54.0 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours, then 23.2 g of amine compound (a1) and 17.4 g of amine compound (a2) were added, and 120 ° C. The temperature was raised to 120 ° C. and maintained for 7.5 hours to obtain a solution of the carbonyl group-containing modified epoxy resin (A6). Thereafter, a mixture of 9.2 g of acetic acid, 4.7 g of 85% phosphoric acid and 100.0 g of water was added to the solution. Further, after adding 1150 g of water, about 930 g is removed while azeotropically evaporating the solvent and water under reduced pressure, diluted with water so that the heating residue becomes about 30%, and the carbonyl group concentration in the resin solids is reduced to 0. An aqueous dispersion (AD6) of a carbonyl group-containing modified epoxy resin (A6) of 61 mol / Kg was obtained. The amine value of this resin was 63 mg-KOH / g, and the weight average molecular weight was about 13,000.

[Production Example 10]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 152.0 g of “jER828” and 271.0 g of propylene glycol monomethyl ether were added and stirred, until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 22.6 g of 2-ethylhexylamine and 55.0 g of “Safphonamine L-100” was added and held at 100 ° C. for 2 hours. Then, 30.9 g of amine compound (a1) and 10.5 g of diethanolamine were used. In addition, the temperature was raised to 120 ° C. and held at 120 ° C. for 7.5 hours to obtain a solution of the carbonyl group-containing modified epoxy resin (A7). Thereafter, a mixture of 17.1 g acetic acid, 8.8 g 85% phosphoric acid and 100.0 g water was added to the solution. Further, after adding 1150 g of water, about 950 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%. An aqueous dispersion (AD7) of a carbonyl group-containing modified epoxy resin (A7) of 45 mol / Kg was obtained. The amine value of this resin was 118 mg-KOH / g, and the weight average molecular weight was about 11,000.

[Production Example 11]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 152.0 g of “jER828” and 277.8 g of propylene glycol monomethyl ether were added and stirred to 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 28.4 g of 2-ethylhexylamine and 55.0 g of “Safphonamine L-100” was added and kept at 100 ° C. for 2 hours, and then 19.3 g of amine compound (a1) and amine compound (a3) 23.0 g was added, and the temperature was raised to 120 ° C. and maintained at 120 ° C. for 7.5 hours to obtain a solution of a carbonyl group-containing modified epoxy resin (A8). Thereafter, a mixture of 15.8 g of acetic acid, 8.1 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1200 g of water, about 1000 g is removed while azeotropically evaporating the solvent and water under reduced pressure, diluted with water so that the heating residue is about 30%, and the carbonyl group concentration in the resin solids is reduced to 0. An aqueous dispersion (AD8) of a carbonyl group-containing modified epoxy resin (A8) of 62 mol / Kg was obtained. The amine value of this resin was 106 mg-KOH / g, and the weight average molecular weight was about 12000.

[Production Example 12]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 16.9 g of diacetone acrylamide, 25.8 g of piperazine, 64.1 g of propylene glycol monomethyl ether were added, The temperature was raised to 100 ° C., and the mixture was stirred at 100 ° C. for 3 hours. Thereafter, 152.0 g of “jER828”, 206.9 g of propylene glycol monomethyl ether, 3.2 g of 2-ethylhexylamine, 55.0 g of “Safphonamine L-100”, and 18.0 g of amine compound (a1) were added at 120 ° C. The temperature was raised to 120 ° C. and maintained at 120 ° C. for 8 hours to obtain a solution of the carbonyl group-containing modified epoxy resin (A9). Thereafter, a mixture of 24.6 g of acetic acid, 12.6 g of 85% phosphoric acid and 100.0 g of water was added to the solution. Further, after adding 1150 g of water, about 950 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%. An aqueous dispersion (AD9) of a carbonyl group-containing modified epoxy resin (A9) of 62 mol / Kg was obtained. The amine value of this resin was 170 mg-KOH / g, and the weight average molecular weight was about 13,000.

[Production Example 13]
Air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 143.6 g of “jER828” and 267.3 g of propylene glycol monomethyl ether were added and stirred, until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 25.8 g of 2-ethylhexylamine, 52.5 g of “Safphonamine L-100” and 4.7 g of isophoronediamine was added and kept at 100 ° C. for 2 hours, and then 40.7 g of amine compound (a2) was added. In addition, the temperature was raised to 120 ° C. and held at 120 ° C. for 7.5 hours to obtain a solution of the carbonyl group-containing modified epoxy resin (A10). Thereafter, a mixture of 13.9 g of acetic acid, 7.1 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1120 g of water, about 910 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%, and the carbonyl group concentration in the resin solids is reduced to 0. An aqueous dispersion (AD10) of a carbonyl group-containing modified epoxy resin (A10) of 62 mol / Kg was obtained. The amine value of this resin was 97 mg-KOH / g, and the weight average molecular weight was about 11,000.

[Production Example 14]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, 143.6 g of “jER828” and 268.1 g of propylene glycol monomethyl ether were added, and the mixture was stirred until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 31.2 g of 2-ethylhexylamine, 10.5 g of “Safphonamine L-100”, “Jeffermin ED2003”, manufactured by Huntsman Corporation, 42.0 g of a polyoxyalkylenediamine compound) In addition, after maintaining at 100 ° C. for 2 hours, 40.7 g of amine compound (a2) was added, the temperature was raised to 120 ° C. and maintained at 120 ° C. for 7.5 hours, and a solution of the carbonyl group-containing modified epoxy resin (A11) Got. Thereafter, a mixture of 13.9 g of acetic acid, 7.1 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1130 g of water, about 920 g of the solvent and water are azeotropically removed under reduced pressure, and diluted with water so that the heating residue is about 30%. An aqueous dispersion (AD11) of a carbonyl group-containing modified epoxy resin (A11) of 62 mol / Kg was obtained. The amine value of this resin was 97 mg-KOH / g, and the weight average molecular weight was about 11,000.

[Production Example 15]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 94.1 g of “jER1001” and 201.6 g of propylene glycol monomethyl ether were added and stirred to 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 15.9 g of 2-ethylhexylamine and 52.8 g of “Surfonamine L-100” was added, and the mixture was kept at 100 ° C. for 2 hours. After the retention, 38.8 g of amine compound (a2), 56.3 g of “jER154” (trade name, manufactured by Japan Epoxy Resin Co., Ltd., phenol novolac type epoxy resin), 56.3 g of propylene glycol monomethyl ether were added at 120 ° C. The temperature was raised to 120 ° C. and maintained for 7.5 hours to obtain a solution of the carbonyl group-containing modified epoxy resin (A12). Thereafter, a mixture of 10.1 g of acetic acid, 5.2 g of 85% phosphoric acid and 100.0 g of water was added to the solution. Further, after adding 1100 g of water, about 900 g is removed while azeotropically evaporating the solvent and water while reducing the pressure, and diluted with water so that the heating residue is about 30%, and the carbonyl group concentration in the resin solids is reduced to 0. An aqueous dispersion (AD12) of a carbonyl group-containing modified epoxy resin (A12) of 62 mol / Kg was obtained. The amine value of this resin was 73 mg-KOH / g, and the weight average molecular weight was about 13,000.

[Comparative Production Example 1]
The air in a 2 L flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet was replaced with nitrogen, and 152.0 g of “jER828” and 253.7 g of propylene glycol monomethyl ether were added and stirred until 100 ° C. The temperature was raised and dissolved. Thereafter, a mixture of 38.8 g of 2-ethylhexylamine, 50.0 g of “Safphonamine L-100” and 12.9 g of dibutylamine was added, and the temperature was raised to 120 ° C. and held at 120 ° C. for 5 hours to remove the carbonyl group. A solution of modified epoxy resin (A13) not containing was obtained. Thereafter, a mixture of 13.5 g of acetic acid, 6.9 g of 85% phosphoric acid, and 100.0 g of water was added to the solution. Further, after adding 1100 g of water, about 900 g is removed while azeotropically evaporating the solvent and water under reduced pressure, and diluted with water so that the heating residue becomes about 30%, and modified epoxy resin containing no carbonyl group (A13) An aqueous dispersion (AD13) was obtained. The amine value of this resin was 100 mg-KOH / g, and the weight average molecular weight was about 11,000.

Production of aqueous primer composition [Example 1]
85 parts (283.3 parts as an aqueous dispersion) of the aqueous dispersion (AD1) of the carbonyl group-containing modified epoxy resin (A1) obtained in Production Example 1 as a solid content, an antirust pigment (C) [vanadium pentoxide 5 parts, 5 parts of calcium phosphate, Shieldex C303 (manufactured by WR Grace & Co., trade name, calcium ion exchanged silica) 5 parts], and titanium white pigment [TS-6200 (manufactured by DuPont)] 30 parts of the mixture was mixed, and the pigment was dispersed until the tub (particle diameter of the coarse pigment particles) became 15 microns or less. Next, a cross-linking agent (B) [Cymel 701 (manufactured by Nippon Cytec Industries, Ltd., methylated melamine resin) 15 parts] was added to this dispersion and mixed uniformly, and the viscosity was about 25 seconds (Ford Cup # 4/25 ° C.) to obtain an aqueous primer composition.

[Examples 2 to 22 and Comparative Examples 1 to 3]
Each aqueous primer composition was obtained in the same manner as in Example 1 according to the blending ratio depending on the solid content shown in Table 1-1 and Table 1-2 below. Note that (Note 1) to (Note 10) in the table are as follows.
(Note 1) Cymel 701: manufactured by Nippon Cytec Industries, Ltd., methylated melamine, solid content 82%
(Note 2) Duranet WT30-100: Water dispersible isocyanate compound manufactured by Asahi Kasei Chemicals Co., Ltd., solid content 100%, this compounded after diluting with water so that the effective solid content is 30% immediately before compounding did.
(Note 3) PR-55317: manufactured by Sumitomo Bakelite Co., Ltd., resole type phenol resin, solid content 50%
(Note 4) Hardener SC: manufactured by Asahi Kasei Chemicals, semicarbazide-based curing agent, concentration 50%
(Note 5) ADH: adipic acid dihydrazide, solid content 100%
(Note 6) Bayhijour VPLS2310: manufactured by Sumika Bayer Urethane Co., Ltd., blocked polyisocyanate compound with water dispersibility, solid content 38%
(Note 7) Shieldex C303: R. Grace & Co. Calcium ion exchange silica
(Note 8) Gasil 200DF: manufactured by Crossfield, silica fine powder
(Note 9) K-White G105: Phosphoric metal salt compound manufactured by Teika
(Note 10) TS6200: manufactured by DuPont, titanium white pigment
Preparation of coating plate for test and performance test
Aqueous primer obtained in the above examples and comparative examples so that the dry film thickness is 5 μm on a 55% aluminum-zinc plated steel plate (galvalume steel plate, plate thickness 0.35 mm, plating AZ150) subjected to chemical conversion treatment -Is applied with a bar coater, heated to reach the material maximum temperature (hereinafter referred to as PMT) 200 ° C. and baked for 45 seconds, and then coated on the opposite surface of the steel plate in the same manner. Baking was performed to obtain a primer-coated steel sheet. Heat the KP color-1555 brown full gloss (manufactured by Kansai Paint Co., Ltd., polyester / melamine paint, glass transition temperature 50 ° C.) on the first painted surface so that the PMT is 220 ° C. so that the dry film thickness is 15 μm. Then, baking was performed for 45 seconds to prepare a test coating plate. Since the test according to the following test conditions of each obtained coating plate for a test was conducted, the results are also shown in Table 1-1 and Table 1-2.

[Machinability (4T processability)]
At a room temperature of 20 ° C., each test coating plate cut to a size of 6 cm × 12 cm was subjected to 4T bending processing (bending with the surface side of the coating plate facing outward, so that the length of the bent portion was 6 cm, Four plates having the same thickness as the coated plate were sandwiched inside, and the coated plate was processed by bending 180 degrees with a vise. The crack resistance of the coating film in the bent portion and the adhesion of the coating film in the bent portion were evaluated according to the following criteria. The adhesion of the coating film in the bent portion was evaluated by the degree of peeling of the coated film in the bent portion when a cellophane adhesive tape was attached to the bent portion and the tape was peeled off instantaneously.

(Draft resistance of the coating film in the bent part)
○: No cracking of the coating film is observed in the processed part, or slight cracking of the coating film is recognized in the processed part
Δ: Significant cracking of the coating is observed in the processed part
X: The crack of a coating film is recognized remarkably in a process part.
(Adhesion of the coating film in the bent part)
○: Degree of peeling of the coating film is not recognized in the processed part, or slight peeling of the coating film is recognized in the processed part
Δ: Peeling of the coating film is considerably observed in the processed part
X: The coating film of the whole process part peels.

[Composite cycle corrosion test (CCT test)]
Conforms to JASO M609-91 (material corrosion test for automobiles, 1991). For each test, cut to a size of 6 cm x 12 cm so that the burrs at the edge of the long side of each test coating plate face the front side on the right side toward the front side and the back side on the left side. Insert a cross cut with a narrow angle of 30 degrees and a line width of 0.5 mm into the center of the surface side of the paint plate using the cutter knife back, and seal the top edge of the paint plate with a rust-proof paint. , 4T bending process part at the upper end (Folding with the front side of the paint plate facing outside, sandwiching four plates with the same thickness as the paint plate inside, and bending the paint plate 180 degrees in a vise) For a coated plate provided with 5 cycles of (5% saline spray at 35 ° C for 2 hours)-(drying at 60 ° C for 4 hours relative humidity 95%)-(wet at 50 ° C for 2 hours relative humidity 95%) as one cycle, 150 cycles (total of 1200 hours) were tested. The state of the 4T bending process part, crosscut part, and edge part of the coated board after this test was evaluated.

[4T processed part] The rust part in the 4T processed part was observed and evaluated according to the following criteria.
A: No occurrence of rust
○: White rust is observed, but less than 20mm
Δ: generation of white rust is 20 mm or more and less than 40 mm
X: Generation | occurrence | production of white rust is 40 mm or more, or generation | occurrence | production of red rust is recognized [Cross cut part] The corrosion state of the cross cut part was observed and evaluated on the following reference | standard.
◎: No white rust or swelling is observed
○: Slight white rust is observed, but no swelling is observed
Δ: Obvious white rust is observed, or white rust is slightly generated, but blistering is observed in the vicinity.
X: White rust is generated in the whole and swelling is generated in the periphery. [Edge part] The average value of the edge creep widths of the left and right long sides of the coated plate was determined and evaluated according to the following criteria.
◎: Corrosion progression width less than 5mm
○: Corrosion progression width of 5 mm or more and less than 10 mm
Δ: Corrosion progression width of 10 mm or more and less than 20 mm
×: Corrosion progression width 20 mm or more

Claims (6)

An amine compound (a) having at least one active hydrogen bonded to a nitrogen atom and having a carbonyl group is reacted with an epoxy resin (b) having two or more epoxy groups in one molecule. A water-based primer composition comprising a modified carbonyl group-containing epoxy resin (A), a crosslinking agent (B) and a rust preventive pigment (C). The amine compound (a) is produced by a Michael addition reaction between diacetone acrylamide and an amine compound (c) having two or more active hydrogens bonded to a nitrogen atom in one molecule. Item 4. The aqueous primer composition according to Item 1. The aqueous primer according to claim 1, wherein the carbonyl group-containing modified epoxy resin (A) has at least one hydrophilic group selected from the group consisting of an anionic group, a cationic group and a nonionic group. -Composition. 2. The crosslinking agent (B) is at least one crosslinking agent selected from the group consisting of an isocyanate compound, a blocked isocyanate compound, an amino resin, a phenol resin, a hydrazide compound, and a semicarbazide compound. An aqueous primer composition. The aqueous primer composition according to claim 1, wherein the rust preventive pigment (C) contains a vanadium compound (c1), a silicon-containing compound (c2), and a phosphoric acid compound (c3). . A coated metal, wherein a cured coating film based on the aqueous primer composition according to any one of claims 1 to 5 is formed on one or both surfaces of a metal plate which may be subjected to chemical conversion treatment on the surface. Board.