JP3008723B2 - Aqueous paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous coating composition. More specifically, an aqueous coating composition characterized by being capable of forming a coating film which is excellent in workability and corrosion resistance and does not require repair after processing as a metal can inner coating.

[0002]

2. Description of the Related Art Conventionally, a metal can is usually provided with a thin synthetic resin protective film in order to prevent a metal material such as tinplate, tin-free steel, and aluminum from directly contacting and corroding the contents. Epoxy paints such as epoxy / phenol, epoxy / amino and epoxy / acryl are usually used as the inner paint of the can because of its excellent adhesion, corrosion resistance and flavor. However, since the paint is based on a thermosetting resin, it has a drawback of poor workability, and the base metal is often exposed in a can-making process. Therefore, the metal exposed portion is repaired after the molding process. However, since such a repair complicates the can-making process, a paint having excellent workability that does not require the repair is demanded. As a coating material that satisfies such demands, there is used a vinyl chloride resin-based organosol coating material which is based on a thermoplastic resin, has a drawback that it has a large amount of extracted components and is inferior in flavor, but has excellent workability.

On the other hand, in recent years, epoxy / acrylic water-based paints have begun to be used in terms of work hygiene, environment, and safety (dangerous substances). As disclosed so far, a water-based paint in which an epoxy resin is esterified with a carboxyl group-containing acrylic resin, neutralized with a base and dispersed in water (JP-B-59-37026), containing a carboxyl group An aqueous paint (Japanese Patent Publication No. 63-17869) in which a polymerizable monomer mixture is grafted onto an epoxy resin using a free radical generator and dispersed in water in the same manner as described above, and an epoxy resin having an acroyl group is converted to acrylic acid Alternatively, there is an aqueous paint (Japanese Patent Publication No. 62-7213) which is copolymerized with an ethylenic monomer containing methacrylic acid and dispersed in water by the same method as described above. All of these are self-emulsifying epoxy resin-based aqueous coatings in which the resin itself exhibits dispersibility, does not contain a surfactant for dispersing in water, and has excellent chemical performance, water resistance, and the like.

[0004]

However, the self-emulsifying type epoxy resin-based water-based coating must contain at least 10% or more of an acrylic resin as an emulsifying component. , The corrosion resistance was poor. The problem to be solved by the present invention is a conventional vinyl chloride resin-based organosol paint, and various problems with a self-emulsifying epoxy resin-based water-based paint, particularly workability, an aqueous paint composition excellent in corrosion resistance. To provide.

[0005]

According to the present invention, there is provided a high-molecular epoxy resin (A) having a number average molecular weight of 9000 to 15,500 and containing 0.5 to 1.1 epoxy groups per molecule. An ammonium salt and / or an amine salt of a product modified to have a united portion;
An aqueous coating composition containing a resole type phenol resin (C).

The high-molecular epoxy resin (A) used in the present invention
Examples thereof include bisphenol A type epoxy resins and bisphenol F type epoxy resins, which have a high number average molecular weight of 9000 or more and have a large number of epoxy groups introduced. If the number average molecular weight is less than 9000, the processability is poor, and if the number of epoxy groups in one molecule is less than 0.5, the adhesion to the underlying metal and the corrosion resistance are poor, and the number average molecular weight is 9000 or more and 1 molecule No epoxy group inside.
Five or more polymeric epoxy resins are preferred. 20 to 90% by weight of the polymer epoxy resin (A) in the constituent components
When the content is less than 20% by weight, the processability is reduced, and
If it exceeds 0% by weight, the adhesion, water resistance and the like will be reduced.

In the present invention, the polymer epoxy resin (A)
Can have a carboxyl group-containing acrylic polymer portion as described in the above publications (JP-B-59-37026, JP-B-63-17869, and JP-B-62-7213). Can be applied mutatis mutandis, and specifically, it is preferably carried out by the following method. (1) A method in which the polymer epoxy resin (A) is esterified with a separately prepared carboxyl group-containing acrylic polymer. The carboxyl group-containing acrylic polymer is one of carboxyl group-containing vinyl monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.
A vinyl monomer copolymerizable with one or more species, for example, styrene monomers such as styrene, vinyl toluene, 2-methylstyrene, t-butylstyrene, chlorostyrene; methyl acrylate, ethyl acrylate, n-acrylate Propyl, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, n-2 ethylhexyl acrylate, n-octyl acrylate, acrylic acid Acrylate monomers such as decyl and dodecyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate;
N-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, n-2-ethylhexyl methacrylate, n-octyl methacrylate, decyl methacrylate, dodecyl methacrylate, Methacrylate monomers such as lauryl methacrylate; hydroxyl-containing monomers such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate; N-methylol ( It is obtained by copolymerizing one or more kinds of N-substituted (meth) acrylic monomers such as (meth) acrylamide and N-butoxymethyl (meth) acrylamide.

[0008] The composition ratio and type of the carboxyl group-containing acrylic polymer are not particularly limited.
The carboxyl group-containing vinyl monomer is preferably 5% by weight or more, particularly 30 to 80% by weight, of methacrylic acid, and the copolymerizable vinyl monomer is 95% by weight or less, particularly 20 to 70%, and is preferably styrene or ethyl acrylate. Average molecular weight 10,000
100000 is preferred. The esterification reaction is basically based on the reaction between a carboxyl group and an epoxy group and / or a hydroxyl group in the acrylic polymer, and an amine esterification catalyst can be used. As the amine esterification catalyst,
For example, dimethylethanolamine, dimethylbenzylamine, ethanolamine, diethanolamine, morpholine and the like can be mentioned.

(2) A method in which a copolymerizable vinyl monomer mixture containing a carboxyl group-containing vinyl monomer is grafted onto a high-molecular epoxy resin (A) using a free radical generator. The vinyl monomer mixture is a carboxyl group-containing vinyl monomer alone or a mixture thereof with another vinyl monomer, and specific examples thereof include those described in the above (1). The composition ratio and type of the vinyl monomer mixture are not particularly limited, but the carboxyl group-containing vinyl monomer is at least 5% by weight, particularly 30 to 100% by weight, and the methacrylic acid is 95% by weight. Hereinafter, styrene and ethyl acrylate are particularly preferred at 0 to 70% by weight.

(3) Acrylic acid and / or methacrylic acid are reacted with the high-molecular epoxy resin (A) to introduce a (meth) acryloyl group, and the group contains acrylic acid and / or methacrylic acid. A method of copolymerizing a vinyl monomer mixture. The reaction ratio between the polymer epoxy resin (A) and acrylic acid and / or methacrylic acid is preferably in the range of 1 / 0.1 to 1 / 1.5 (molar ratio). Specific examples of the vinyl monomer mixture include those shown in the above (1),
Although the type is not particularly limited, methacrylic acid accounts for at least 5% by weight of the carboxyl group-containing vinyl monomer, particularly 30 to 80% by weight.
Styrene and ethyl acrylate are preferred up to 20% by weight, especially 20-70% by weight.

The ratio (weight ratio) of the carboxyl group-containing acrylic polymer portion to the high molecular weight epoxy resin is preferably 7/93 to 71/29. If the content of the carboxyl group-containing acrylic polymer portion is less than 7% by weight, it is difficult to make aqueous, and if it exceeds 71% by weight, the adhesion, corrosion resistance and workability to the base material are reduced. More preferably, the ratio is between 10/90 and 30/7
0. The carboxyl group-containing acrylic polymer portion in the solid content of the aqueous coating composition is 7 to 50% by weight, and 7 to 50% by weight.
Preferably it is 30% by weight. If it is less than 7% by weight, it is difficult to make the aqueous solution, and if it is more than 50% by weight, the adhesion, corrosion resistance, workability, etc. are reduced. The esterified product obtained by the method shown in (1), the grafted product obtained by the method shown in (2), and the copolymer obtained by the method shown in (3) are each a polymer epoxy resin (A ) To which a carboxyl group-containing acrylic polymer portion is mainly bonded, and a partially unbound polymer epoxy resin (A) and a partially unbound carboxyl group-containing acrylic polymer coexist in the solution. Some do.

Examples of the vinyl monomer polymerization catalyst and the catalyst for grafting a carboxyl group-containing vinyl monomer to the polymer epoxy resin (A) used in the reaction according to the above methods (1) to (3) include organic peroxides. Oxides, persulfates, azobis compounds, and Redox-based catalysts obtained by combining these with a reducing agent can be used. Specifically, benzoyl peroxide, perbutyl octate, t-butyl hydroperoxide, azobisisobutyronitrile, azobisvaleronitrile, 2,2′-
Azobis (2-aminopropane) hydrochloride and the like can be mentioned. As the free radical generator as the graft catalyst, benzoyl peroxide and the like are particularly preferable. These are generally used in an amount of 0.1 to 100 parts by weight of the reaction components.
It can be used in a proportion of 5 to 20 parts by weight.

The reaction (1) for obtaining an acrylic polymer,
The esterification reaction shown in (1), the graft reaction shown in (2), the reaction for obtaining the (meth) acryloyl group-containing mixture shown in (3), and the copolymerization reaction of the (meth) acryloyl group-containing mixture, It is preferable to carry out the reaction in an organic solvent system, and the organic solvent used is a solvent which dissolves a monomer such as a vinyl monomer, a copolymer thereof, a polymer epoxy resin (A), etc., and is easily mixed with water. Preferred are, for example, alcohol-based, glycol-based, diglycol-based, and acetate-based solvents. Specifically, n-propanol, isopropal, n-butyl alcohol, isobutyl alcohol, n-amyl alcohol, amyl alcohol, methyl amyl alcohol, ethylene glycol, diethylene glycol, 1,3-butylene glycol, ethylene glycol monoethyl ether, Ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, methyl propylene glycol, methyl propylene diglycol, propyl propylene glycol, propyl propylene diglycol, butyl propylene glycol, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene Glycol monomethyl ether ace Over DOO, 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, can be mentioned 3-methyl-3-methoxybutyl acetate and the like. Other solvents can be used, but those which can be removed under reduced pressure later are preferred.

The esterified product obtained by the method shown in the above (1), the grafted product obtained by the method shown in the above (2), or the ammonium of the copolymer obtained by the method shown in the above (3) used in the present invention. Salts and / or amine salts are
An esterified product obtained by the method shown in the above (1),
It is obtained by neutralizing the carboxyl group in the grafted product obtained by the method shown in (2) and the carboxyl group in the copolymer obtained by the method shown in (3) with ammonia and / or amine. Examples of the amine include alkylamines such as trimethylamine, triethylamine and butylamine; alcoholamines such as dimethylaminoethanol, diethanolamine and aminomethylpropanol; and volatile amines such as morpholine.

The resole type phenol resin used in the present invention is a resin obtained by condensing an arbitrary phenol component and formaldehyde in the presence of a basic catalyst.
Further, phenol components constituting the resol type phenol resin include o-cresol, p-cresol, p-te
rt-butylphenol, p-ethylphenol, 2,3
Bifunctional phenols such as -xylenol, 2,5-xylenol, p-tert-aminophenol, p-nonylphenol, p-phenylphenol, p-cyclohexylphenol, phenolic acid, m-cresol, m-ethylphenol, 3, Trifunctional phenols such as 5-xylenol and m-methoxyphenol, monofunctional phenols such as 2,4-xylenol and 2,6-xylenol,
Bisphenol A: A single or a combination of two or more of tetrafunctional phenols such as bisphenol B and bisphenol F is used. As the basic catalyst, for example, ammonia, amine, hydroxide of alkaline earth metal, oxide of alkali metal, oxide of alkaline earth metal, or the like can be used. If the resole type phenolic resin is less than 2% by weight, the crosslinking density is low and the corrosion resistance is inferior, and 30% by weight.
On the other hand, when the ratio exceeds 2, the crosslink density becomes too high and the processability decreases, so that 2 to 30% by weight is preferable.

It is possible to add a solvent, a surfactant and an antifoaming agent for improving the coatability to the aqueous coating composition of the present invention, if necessary. After the formation of the coating film, a wax as a lubricant may be added to the aqueous coating composition of the present invention for the purpose of preventing the coating film from being scratched during processing and transportation. It is also possible to add an amino resin as a curing agent to the aqueous coating composition of the present invention, but adding a large amount is not preferable because the crosslink density becomes too high and the processability decreases. Addition of up to 5% by weight is preferred. As a substrate to be applied, a treated or untreated metal plate such as an aluminum plate, a steel plate, a zinc steel plate, a tin plate, etc. is suitable. Or directly on a metal material. As the painting method,
Various methods known in this field, for example, roll coater coating, spray coating, dip coating, electrodeposition coating and the like can be applied. Among them, roll coater coating and spray coating are preferable. The drying and curing conditions are as follows.
~ 30 minutes or 15 ~ 60 at 240 ~ 300 ° C
Seconds are preferred.

[0017]

Next, the present invention will be described more specifically with reference to examples. In the examples, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively. Production Example 1 Production of Epoxy Resin Solution (A) Epicoat 828EL (manufactured by Yuka Shell Epoxy Co., Ltd.) 372.1 parts Bisphenol A (Mitsui Toatsu Chemical Co., Ltd.) 225.1 parts Sodium methylate (28% methanol solution) 0.11 part Solvesso 150 (Mitsubishi Sekiyu KK) 66.4 parts Epicoat 828EL (Yukaka Epoxy Co., Ltd.) 2.8 parts Ethylene glycol monoethyl ether 333.5 parts Charge 4 into a four-necked flask and heat gradually under a nitrogen stream. The reaction was carried out at 160 ° C., then added little by little, and allowed to react until the epoxy equivalent reached 25,000.
The reaction was allowed to reach 9000, cooled to 160 ° C. or lower, and then added, followed by a 60% epoxy resin solution having a number average molecular weight of 15000 and an epoxy group of 0.8 per molecule.
(A) was obtained.

Production Example 2 Production of Epoxy Resin Solution (B) Epicoat 828EL (manufactured by Yuka Shell Epoxy Co., Ltd.) 371.8 parts Bisphenol A (Mitsui Toatsu Chemical Co., Ltd.) 224.9 parts Sodium methylate (28% methanol solution) 0.11 part Solvesso 150 (Mitsubishi Oil Co., Ltd.) 66.3 parts Epikote 828EL (manufactured by Yuka Shell Epoxy Co., Ltd.) 6.0 parts Ethylene glycol monoethyl ether 330.9 parts In the same manner as in Production Example 1, the number average molecular weight is 15,500. ,
A 60% epoxy resin solution (B) having 1.1 epoxy groups per molecule was obtained.

Production Example 3 Production of Carboxyl Group-Containing Acrylic Polymer (C) Styrene 210.0 parts Ethyl acrylate 210.0 parts Methacrylic acid 180.0 parts Benzoyl peroxide 20.0 parts n-butanol 380.0 parts A four-necked flask was charged and placed under a nitrogen stream. At 100 ° C. over 3 hours, and the mixture was kept at the same temperature for 2 hours to obtain a 60% carboxyl group-containing acrylic polymer solution (C).

Production Example 4 Production of resol type phenol resin solution (D) Bisphenol A 485.1 parts Formalin 40% n-butanol solution 478.7 parts 25% ammonia water 36.2 parts
After reacting at 5 ° C. for 5 hours, xylene / n-butanol / cyclohexanone = 1/1/1 was added for dilution, followed by dehydration to obtain a 35% resol phenol resin solution (D).

Production Example 5 Production of resol type phenol resin solution (E) 417.7 parts of p-cresol 580.1 parts of formalin 40% n-butanol solution 2.2 parts of magnesium hydroxide The reaction was carried out in the same manner as in Production Example 4 for 2.5 hours. Thereafter, the mixture is neutralized with phosphoric acid, a large amount of water such as xylene / n-butanol / cyclohexanone = 1/1/1 is added thereto, and the mixture is left for 5 hours. As a result, a 35% resol type phenol resin solution (E) was obtained.

Example 1 Epoxy resin solution (A) 271.0 parts Carboxyl group-containing acrylic polymer (C) 83.1 parts Dimethylaminoethanol 15.5 parts Resole-type phenol resin solution (D) 107.2 parts Ion-exchanged water 523.2 parts In a four-necked flask Was added, and the mixture was added while being stirred under a nitrogen stream to substantially neutralize the carboxyl groups contained therein. Then, the internal temperature was raised to 80 ° C., the mixture was stirred at this temperature for 30 minutes, and then room temperature was added. Cooled down. The reduction rate of the oxirane% was 70%, and the viscosity was increased as compared to before the cooking. After cooking, the mixture was further added with stirring, and further added little by little to obtain an aqueous dispersion having a solid content of 25%.

Examples 2 to 4 In the same manner as in Example 1, the epoxy resin solutions (A) and (B) and the carboxyl group-containing acrylic polymer solution (C) were cooked in the proportions shown in Table 1 and further cooked. Resol type phenol resin solution (D), (E) and ion exchanged water were added and the solid content was 25
% Aqueous dispersion was obtained.

[0024]

[Table 1]

Example 5 Epoxy resin solution (A) 270.8 parts n-butanol 70.0 parts Styrene 17.5 parts Ethyl acrylate 17.5 parts Methacrylic acid 15.0 parts Benzoyl peroxide 3.5 parts Resole-type phenol resin solution (D) 107.1 parts Dimethylaminoethanol 15.5 Part Ion-exchanged water 483.1 parts was charged into a four-necked flask, the internal temperature was raised to 110 ° C., and a mixed solution of was added dropwise over 2 hours while stirring under a nitrogen stream, followed by cooling to room temperature. Was added in small portions to obtain an aqueous dispersion having a solid content of 25%.

In the same manner as in Example 5, 35 parts of styrene were added to the epoxy resin solutions (A) and (B) in the proportions shown in Table 2.
A vinyl monomer mixture of 35 parts of ethyl acrylate, 30 parts of methacrylic acid, and 7 parts of benzoyl peroxide was added dropwise, and resole-type phenol resin solutions (D), (E) and dimethylaminoethanol were added, and ion-exchanged water was further added. Was added little by little to obtain an aqueous dispersion having a solid content of 25%.

[0027]

[Table 2]

Example 9 (1) 270.8 parts of epoxy resin solution (A) (2) 1.5 parts of methacrylic acid (3) 0.03 part of sodium hydroxide (4) 70.0 parts of n-butanol (5) 17.5 parts of styrene (6) Acrylic Ethyl acid 17.5 parts (7) Methacrylic acid 13.5 parts (8) Benzoyl peroxide 1.0 part (9) Resole type phenol resin solution (D) 107.1 parts (10) Dimethylaminoethanol 13.9 parts (11) Deionized water 487.2 parts 4 Charge (1) to (3) in a neck flask and adjust the internal temperature to 120 to
The temperature was raised to 130 ° C., the reaction was advanced under a nitrogen stream, and when the acid value became 0.5 or less, the mixture was cooled, (4) was added at 90 ° C., and further kept at 90 ° C. while stirring (5 ) To (8) were added dropwise over 2 hours, and the mixture was cooled to room temperature. continue
(9) to (10) were added, and (11) was added little by little with stirring to obtain an aqueous dispersion having a solid content of 25%.

Examples 10 to 12 In the same manner as in Example 9, the epoxy resin solutions (A) and (B), methacrylic acid and sodium hydroxide were charged and reacted according to the formulation shown in Table 3, and 35 parts of styrene were further reacted. , 35 parts of ethyl acrylate, 27 parts of methacrylic acid, and 2 parts of benzoyl peroxide in a vinyl monomer mixture were added dropwise. Subsequently, resol-type phenol resin solutions (D), (E) and dimethylaminoethanol were added and stirred. While adding ion-exchanged water little by little, an aqueous dispersion having a solid content of 25% was obtained.

[0030]

[Table 3]

Comparative Production Example 1 Production of Epoxy Resin Solution (F) Epicoat 1007 (manufactured by Yuka Shell Epoxy Co., Ltd.) 600.0 parts Ethylene glycol monoethyl ether 400.0 parts In a four-necked flask were charged and placed under a nitrogen stream. 100
The mixture was heated to ℃ and completely dissolved to obtain a 60% epoxy resin solution (F) having a number average molecular weight of 2,900 and an epoxy group of 1.5 per molecule. Comparative Production Example 2 Production of Epoxy Resin Solution (G) Epicoat 1009 (manufactured by Yuka Shell Epoxy Co., Ltd.) 600.0 parts Ethylene glycol monoethyl ether 400.0 parts ~ was placed in a four-necked flask, and 100 parts were placed under a nitrogen stream.
℃, completely dissolved and number average molecular weight 10,000, 1
A 60% epoxy resin solution (G) having 0.3 epoxy groups per molecule was obtained.

Comparative Example 1 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 1 except that the epoxy resin solution (A) in Example 1 was changed to the epoxy resin solution (F). . Comparative Example 2 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 5 except that the epoxy resin solution (A) in Example 5 was changed to the epoxy resin solution (F). Comparative Example 3 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 9 except that the epoxy resin solution (A) in Example 9 was changed to the epoxy resin solution (F).

Comparative Example 4 Resol type phenol resin solution in Example 9 above
Except for removing (D), all operations were performed in the same manner as in Example 9 to prepare ion-exchanged water to obtain an aqueous dispersion having a solid content of 25%. Comparative Examples 5 to 8 Except that the composition in Example 1 was changed to the composition shown in Table 4, the same procedure was performed as in Example 1 to obtain a solid content of 25%.
Was obtained. Comparative Example 9 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 1 except that the epoxy resin solution (A) in Example 1 was changed to the epoxy resin solution (G).

Comparative Example 10 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 5 except that the epoxy resin solution (A) in Example 5 was changed to the epoxy resin solution (G). . Comparative Example 11 An aqueous dispersion having a solid content of 25% was obtained in the same manner as in Example 9 except that the epoxy resin solution (A) in Example 9 was changed to the epoxy resin solution (G).

[0035]

[Table 4]

Method for preparing paint The organic solvent contained in the aqueous dispersions obtained in the above Examples and Comparative Examples was adjusted so that the content was 15% in the paint at a solid content of 25%. It was adjusted by removing under reduced pressure.

Performance Test As a result of the storage stability test results of the aqueous coating compositions obtained in Examples 1 to 12 and Comparative Examples 1 to 10, the composition was coated on a tin plate with a bar coater so as to have a thickness of 10 μm. Test panels were prepared by baking and drying for 5 minutes, and the results of evaluating various physical properties are shown in Tables 5 and 6. Various test methods in Table 5 are as follows. (1) Storage stability of the paint: The paint was stored in a thermostat at 50 ° C., and the appearance and properties were periodically evaluated. Good storage stability ・ ・ ・ ・ ○ Abnormalities such as gelation, sedimentation and separation occurred during storage ・ ・ ・ ・ × (2) Adhesion: Approximately 1.5 mm width using a knife on the coating surface Then, 11 vertical and horizontal cuts are made in the goban. The number of unstripped portions of the gobang when the cellophane adhesive tape having a width of 24 mm is closely adhered and strongly peeled is represented by a molecule. (3) Water resistance: treated in water at 125 ° C. for 40 minutes to determine the surface condition of the coating film. (4) Workability: It is generated when a folded sample is placed at the bottom using a special goby-folding type ポ ン upon impact tester, and an iron weight with a flat contact surface and a weight of 1 kg is dropped from a height of 50 cm. The length of the crack in the coating film at the bent portion was measured.

0 to 10 mm ··· 10 to 20 mm ··· △ 20 mm or more ··· × (5) Corrosion resistance: The cross-section of the mark X was cut on the coating surface using a knife. The test piece is treated in a 1% saline solution at 125 ° C. for 40 minutes, and the degree of corrosion in the vicinity of the X mark is determined. No abnormality ・ ・ ・ ・ ○ mark Slightly corroded ・ ・ ・ ・ △ mark Significantly corroded ・ ・ ・ ・ ×

[0039]

[Table 5]

[0040]

[Table 6]

[0041]

According to the present invention, it is possible to improve the good workability and the adhesion to the base material, and to increase the crosslink density after curing to impart corrosion resistance.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-215015 (JP, A) JP-A-60-215016 (JP, A) JP-A-63-43966 (JP, A) JP-A-4- 351682 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 1/00-201/10

Claims (3)

(57) [Claims] (1) Number average molecular weight is 9000~ 15500
And 0.5 epoxy groups per molecule~ 1.1Including
Carboxy group-containing acrylic polymer (A)
Of the reaction product obtained by esterification with the polymer (B)
Monium salt and / or amine salt and resole type pheno
A water-based coating composition containing a water-soluble resin composition (C), wherein the solid content of the water-based coating composition is 100% by weight.
The epoxy resin (A)
20 to 90% by weight of the carboxyl group-containing acrylic copolymer (B)
 7 to 50% by weight Resol type phenol resin (C)
 2 to 30% by weight. (2) Number average molecular weight is 9000~ 15500
And 0.5 epoxy groups per molecule~ 1.1that's all
Radical generation in high molecular epoxy resin (A) containing
Using carboxyl group-containing vinyl monomer
Do not graft the polymerizable vinyl monomer mixture.
Ammonium salt and / or amine salt of the reaction product
And an aqueous solution containing a resol-type phenol resin (C)
A paint composition wherein the solid content of the aqueous paint composition is 100% by weight.
The epoxy resin (A)
20 to 90% by weight Carboxyl group-containing vinyl to be subjected to the graft reaction
Copolymerizable vinyl monomer mixture containing monomers (B
2) 7 to 50% by weight Resol type phenol resin (C)
 2 to 30% by weight. (3) Number average molecular weight is 9000~ 15500
And 0.5 epoxy groups per molecule~ 1.1Including
Acrylic acid and / or
(Meth) acryloyl group containing by reacting acrylic acid
Essential compound, acrylic acid and / or methacrylic acid
Copolymerization by copolymerization with vinyl monomer contained as a component
Ammonium and / or amine salts of the
Aqueous phenolic resin composition containing phenolic resin (C)
When the solid content of the aqueous coating composition is 100% by weight
The epoxy resin (A)
20 to 90% by weight Acrylic acid to be reacted with the epoxy resin (A)
And / or methacrylic acid, and the (meth) acryloyl
Acrylic acid and / or used for copolymerization with
Or vinyl monomer containing methacrylic acid as an essential component
(B3) 7 to 50% by weight of the resol-type phenol resin (C)
 2 to 30% by weight.