JPH06287508A - Water-based coated composition - Google Patents

Abstract

PURPOSE:To provide a water-baed coating composition which forms, on the inner surface of a metal can which surface is required to have high processability and corrosion resistance, a coating film when applied to the metal substrate directly or through an undercoat and dried and baked, which film needs especially no repair after processing. CONSTITUTION:This coating composition is obtained from 20-90wt.% high- molecular epoxy resin (A) having a number-average mol.wt. of 9,000 or higher and 0.5 or more epoxy groups per molecule, 7-50wt.% carboxylated acrylic polymer (B), and 2-30wt.% phenol resol resin (C). An ammonium and/or amine salt of the product of the reaction of the resin (A) with the polymer (B) is used with the resin (C).

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, metal cans have usually been provided with a thin synthetic resin protective coating in order to prevent metal materials such as tin plate, tin-free steel and aluminum from directly contacting the contents and corroding. As the can inner surface paint, epoxy-based paints such as epoxy / phenol, epoxy / amino and epoxy / acryl are usually used because of their excellent adhesion, anticorrosion properties and flavor. However, since the above-mentioned paint is based on a thermosetting resin, it has a drawback of poor workability, and the base metal is often exposed in the can manufacturing process. Therefore, the metal exposed portion is repaired after the molding process. However, such repair complicates the can manufacturing process, and therefore a paint having excellent workability that does not require repair is demanded. As a coating material satisfying such demands, a vinyl chloride resin-based organosol coating material having excellent processability is used, although it is based on a thermoplastic resin and has the drawback of having many extracted components and inferior flavor.

On the other hand, in recent years, epoxy / acrylic water-based paints have begun to be used in view of work hygiene / environment or safety (dangerous substances). What has been disclosed so far is an aqueous coating obtained by esterifying an epoxy resin with an acrylic resin containing a carboxyl group, neutralizing it with a base and dispersing it in water (JP-B-59-37026), containing a carboxyl group. A water-based paint prepared by grafting a polymerizable monomer mixture onto an epoxy resin using a free radical generator and dispersing it in water in the same manner as described above (Japanese Patent Publication No. Sho 63-17869), and an epoxy resin having an acroyl group to acrylic acid. Alternatively, there is an aqueous coating composition (Japanese Patent Publication No. 62-7213) in which an ethylenic monomer containing methacrylic acid is copolymerized and dispersed in water by the same method as described above. All of these are self-emulsifying type epoxy resin-based water-based paints in which the resin itself exhibits dispersibility, do not contain a surfactant for dispersion in water, and have excellent chemical performance, water resistance and the like.

[0004]

However, the above self-emulsifying type epoxy resin-based water-based coating composition needs to contain at least 10% or more of an acrylic resin as an emulsifying component, which lowers processability and has few reaction points and crosslink density. The corrosion resistance was inferior because of low. The problems to be solved by the present invention are various problems of conventional vinyl chloride resin-based organosol paints, and self-emulsifying epoxy resin-based water-based paints, and particularly, workability, and an aqueous paint composition excellent in corrosion resistance. To provide.

[0005]

MEANS FOR SOLVING THE PROBLEMS The present invention provides a polymer epoxy resin (A) having a number average molecular weight of 9000 or more and containing 0.5 or more epoxy groups per molecule, 20 to 90% by weight, and a carboxyl group-containing acrylic resin. Polymer (B) 7 to 50% by weight, resol-type phenol resin (C) 2 to 30% by weight, (A) to (C) as constituents, and ammonium of a reaction product of (A) and (B) A water-based coating composition comprising a salt and / or an amine salt and a resol-type phenol resin (C).

Polymer epoxy resin (A) used in the present invention
Examples thereof include a bisphenol A type epoxy resin and a bisphenol F type epoxy resin, which have a high molecular weight of 9000 or more and have many epoxy groups introduced. When the number average molecular weight is less than 9000, the processability is poor, and when the epoxy group is less than 0.5 in one molecule, the adhesion to the base metal and the corrosion resistance are poor, and the number average molecular weight is 9000 or more and one molecule Epoxy group is 0.
Polymeric epoxy resins of 5 or more are preferred. As the polymer epoxy resin (A) in the constituent components, 20 to 90% by weight
Is preferable, and if it is less than 20% by weight, the workability is deteriorated and 9
If it exceeds 0% by weight, the adhesion, water resistance and the like will deteriorate.

Polymeric epoxy resin (A) in the present invention
The method for obtaining a reaction product of the above with the carboxyl group-containing acrylic polymer (B) is described in the above-mentioned publication (Japanese Patent Publication No. 59-37026).
The methods described in JP-B-63-17869 and JP-B-62-7213) can be applied correspondingly, and specifically, the following method is preferable. (1) A method of esterifying a high molecular weight epoxy resin (A) with a separately prepared carboxyl group-containing acrylic polymer. The carboxyl group-containing acrylic polymer is a vinyl monomer copolymerizable with one or more carboxyl group-containing vinyl monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid.
For example, styrene-based monomers such as styrene, vinyltoluene, 2-methylstyrene, t-butylstyrene, chlorostyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, acrylic. Acrylate ester monomers such as isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, n-2 ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, 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, lauryl methacrylate Methacrylic acid ester-based monomers such as; hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate; N-methylol (meth) acrylamide , N-butoxymethyl (meth) acrylamide and other N-substituted (meth) acrylic monomers and the like, which are obtained by copolymerizing one kind or two or more kinds thereof.

The carboxyl group-containing acrylic polymer is not particularly limited in composition ratio and kind,
Carboxyl group-containing vinyl monomer is 5% by weight or more, especially 30 to 80% by weight of methacrylic acid, and copolymerizable vinyl monomer is 95% by weight or less, especially 20 to 70% of styrene and ethyl acrylate are preferable. Average molecular weight 10,000 ~
100000 is preferred. The esterification reaction is basically a reaction of a carboxyl group with an epoxy group and / or a hydroxyl group in the acrylic polymer, and an amine-based esterification catalyst can be used. As the amine esterification catalyst,
Examples thereof include dimethylethanolamine, dimethylbenzylamine, ethanolamine, diethanolamine and morpholine.

(2) A method in which a copolymerizable vinyl monomer mixture containing a carboxyl group-containing vinyl monomer is grafted onto the polymer 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 (1) above. The composition ratio and type of the vinyl monomer mixture are not particularly limited, but 5% by weight or more of the carboxyl group-containing vinyl monomer, particularly 30 to 100% by weight of methacrylic acid, and 95% by weight of the copolymerizable vinyl monomer. Below, styrene and ethyl acrylate are particularly preferable at 0 to 70% by weight.

(3) A high molecular epoxy resin (A) is reacted with acrylic acid and / or methacrylic acid to introduce a (meth) acryloyl group, and then 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 (1) above.
Although the type is not particularly limited, carboxylic acid-containing vinyl monomer is 5% by weight or more, especially 30 to 80% by weight of methacrylic acid, and copolymerizable vinyl monomer is 95% by weight.
Styrene and ethyl acrylate are preferable in the amount of not more than 20% by weight, particularly 20 to 70% by weight.

The carboxyl group-containing acrylic polymer and the high molecular weight epoxy resin are preferably 7/93 to 71/29 (weight ratio).
If the amount of the carboxyl group-containing acrylic polymer is less than 7% by weight, it becomes difficult to make it aqueous, and if it exceeds 71% by weight, the adhesion to the base material, the corrosion resistance and the processability are deteriorated. More preferably, the above ratio is 10/90 to 30/70 (weight ratio)%. The carboxyl group-containing acrylic polymer (C) in the constituents is preferably from 7 to 30% by weight, and when it is less than 7% by weight, it becomes difficult to make it water-soluble, and when it exceeds 30% by weight, adhesion, corrosion resistance, and Workability and the like are reduced. The high molecular weight epoxy resin, which is a reaction product with the acrylic polymer shown in (1) to (3) above, is mainly one in which a carboxyl group-containing acrylic polymer is bound, and the solution is partially unbound. In some cases, the high molecular weight epoxy resin and the carboxyl group-containing acrylic polymer coexist.

Examples of the polymerization catalyst of the vinyl monomer used for the reaction production of the acrylic polymer shown in the above (1) to (3) and the catalyst for grafting the carboxyl group-containing vinyl monomer onto the polymer epoxy resin (A) include: , An organic peroxide, a persulfate, an azobis compound, and a redox system in which these are combined 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 are mentioned, and benzoyl peroxide is particularly preferable as a free radical generator as a graft catalyst. These are generally less than 100 parts by weight of the reaction components.
It can be used in a proportion of 5 to 20 parts by weight.

The acrylic polymer of (1) and (1) to (3)
It is preferable to carry out the acrylic polymer reaction shown in 1. in an organic solvent system. The organic solvent to be used is a monomer such as vinyl monomer and its copolymer, a high molecular weight epoxy resin (A).
It is preferable to use a solvent that dissolves the above and is easily mixed with water, and examples thereof include alcohol-based, glycol-based, diglycol-based, and acetate-based solvents. Specifically, n-propanol, isopropal, n-butyl alcohol, isobutyl alcohol, n-amyl alcohol, amyl alcohol, methylamyl 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- methoxide butyl 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 preferable.

Polymer epoxy resin (A) used in the present invention
In order to obtain an ammonia salt and / or an amine salt of a reaction product of a carboxyl group-containing acrylic polymer (B), ammonia and / or amine are added to the above (1) to (3).
It is obtained by neutralizing the carboxyl group of the carboxyl group-containing acrylic polymer (B) shown in (4). Examples of the amine include alkylamines such as trimethylamine, triethylamine and butylamine, alcohol amines such as dimethylaminoethanol, diethanolamine and aminomethylpropanol, and volatile amines such as morpholine.

The resol 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, as the phenol component constituting the resol type phenol resin, 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, carboxylic 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: Bifunctional phenols such as bisphenol B and bisphenol F may be used alone or in combination of two or more. As the basic catalyst, for example, ammonia, amine, hydroxide of alkaline earth metal, oxide of alkali metal, oxide of alkaline earth metal and the like can be used. If the resol type phenolic resin is less than 2% by weight, the crosslink density is low and the corrosion resistance is inferior.
On the other hand, if it exceeds the range, on the contrary, the crosslinking density becomes too high and the workability is deteriorated, so 2 to 30% by weight is preferable.

It is possible to add a solvent, a surfactant or a defoaming agent for improving the coating property to the water-based coating composition of the present invention, if necessary. It is also possible to add a wax, which is a lubricant, to the water-based coating composition of the present invention after forming a coating film to prevent scratches on the coating film during processing and transportation. It is also possible to add an amino resin as a curing agent to the water-based coating composition of the present invention, but addition of a large amount undesirably raises the crosslink density too much and lowers the processability. Addition of 5% by weight or less is preferable. As a base material to be applied, a metal plate of treated or untreated one such as an aluminum plate, a steel plate, a zinc steel plate, a tin plate is suitable, and an epoxy-based or vinyl-based primer is used as an undercoat. It can be either directly or directly on the metal material. As a painting method,
Various methods known in the art, such as roll coater coating, spray coating, dip coating, and electrodeposition coating, can be applied, but among these, roll coater coating and spray coating are preferable. The dry curing conditions are 150 to 230 ° C. and 1
~ 30 minutes or 240 ~ 300 ℃ 15 seconds ~ 60
Seconds are preferred.

[0017]

EXAMPLES Next, the present invention will be described more specifically by way of 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 Chemicals, Inc.) 225.1 parts Sodium methylate (28% solution in methanol) 0.11 parts Solvesso 150 (Mitsubishi Oil Co., Ltd.) 66.4 parts Epicoat 828EL (produced by Yuka Shell Epoxy Co., Ltd.) 2.8 parts Ethylene glycol monoethyl ether 333.5 parts Charge 4 to a 4-neck flask and heat gradually under a nitrogen stream. The mixture was reacted at 160 ° C, then was added little by little and reacted until the epoxy equivalent became 25000, then was added and the temperature was further raised to 200 ° C to make the epoxy equivalent 1
React until 9000, cool to 160 ° C or lower, and then add, 60% epoxy resin solution with a number average molecular weight of 15,000 and 0.8 epoxy groups per molecule
I got (A).

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 Chemicals, Inc.) 224.9 parts Sodium methylate (28% solution in methanol) ) 0.11 part Solvesso 150 (Mitsubishi Petroleum Co., Ltd.) 66.3 parts Epicoat 828EL (produced 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 15500. ,
A 60% epoxy resin solution (B) having an epoxy group of 1.1 per molecule was obtained.

Production Example 3 Production of Acrylic Polymer Containing Carboxyl Group (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 4 neck flask was charged under a nitrogen stream. The mixture solution was heated to 100 ° C. at 100 ° C. and added dropwise at 100 ° C. for 3 hours and 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 Phenolic Resin Solution (D) Bisphenol A 485.1 parts Formalin 40% n-butanol solution 478.7 parts 25% Ammonia water 36.2 parts A 4-neck flask was charged with to 100 under a nitrogen stream.
After reacting at 5 ° C for 5 hours, xylene / n-butanol / cyclohexanone = 1/1/1 was added to dilute and further dehydrated to obtain 35% resol type phenol resin solution (D).

Production Example 5 Production of Resol-type Phenolic Resin Solution (E) p-Cresol 417.7 parts Formalin 40% n-butanol solution 580.1 parts Magnesium hydroxide 2.2 parts Reaction was carried out for 2.5 hours in the same manner as in Production Example 4. After that, neutralize with phosphoric acid, add a large amount of water such as xylene / n-butanol / cyclohexanone = 1/1/1 and let stand for 5 hours to separate and remove the aqueous layer containing the produced salt, and further azeotropic dehydration. Thus, 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 Resol type phenol resin solution (D) 107.2 parts Ion-exchanged water 523.2 parts In a 4-necked flask Is charged, and is added with stirring under a nitrogen stream to neutralize equimolar moles of the contained carboxyl groups, then the internal temperature is raised to 80 ° C., and the mixture is stirred at this temperature for 30 minutes and then at room temperature. Cooled down. The reduction rate of oxirane% was 70%, and the viscosity was increased as compared with that before cooking. After cooking, the mixture was added with stirring, and the mixture was added little by little to obtain an aqueous dispersion having a solid content of 25%.

Examples 2 to 4 Epoxy resin solutions (A) and (B) and a carboxyl group-containing acrylic polymer solution (C) having the composition shown in Table 1 were cooked in the same manner as in Example 1, and further prepared. Resol type phenol resin solution (D), (E) and deionized water were added and 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 Resol type phenol resin solution (D) 107.1 parts Dimethylaminoethanol 15.5 Part Ion-exchanged water 483.1 parts A 4-necked flask was charged with, the internal temperature was raised to 110 ° C., the mixture was added dropwise over 2 hours with stirring under a nitrogen stream and cooled to room temperature. After adding ~, a small amount was added little by little to obtain an aqueous dispersion having a solid content of 25%.

Examples 6 to 8 35 parts of styrene, 35 parts of ethyl acrylate and 30 parts of methacrylic acid were added to the epoxy resin solutions (A) and (B) in the formulations shown in Table 2 in the same manner as in Example 1. , Benzoyl peroxide 7 parts vinyl monomer mixture was added dropwise, resol type phenol resin solution (D), (E) and dimethylaminoethanol were additionally added, and ion-exchanged water was added little by little to obtain a solid content of 25%. An aqueous dispersion was obtained.

[0027]

[Table 2]

Example 9 (1) Epoxy resin solution (A) 270.8 parts (2) Methacrylic acid 1.5 parts (3) Sodium hydroxide 0.03 parts (4) n-Butanol 70.0 parts (5) Styrene 17.5 parts (6) Acrylic Ethyl acid 17.5 parts (7) Methacrylic acid 13.5 parts (8) Benzoyl peroxide 1.0 part (9) Resol type phenol resin solution (D) 107.1 parts (10) Dimethylaminoethanol 13.9 parts (11) Ion-exchanged water 487.2 parts 4 parts Charge (1) to (3) into the neck flask and set the internal temperature to 120 to
Raise the temperature to 130 ℃, proceed the reaction under nitrogen flow, cool when the acid value becomes 0.5 or less, add (4) at 90 ℃, keep it at 90 ℃ and stir (5 ) To (8) was added dropwise over 2 hours and 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 Epoxy resin solutions (A), (B), methacrylic acid and sodium hydroxide having the composition shown in Table 3 were added and reacted in the same manner as in Example 1, and 35 parts of styrene was further added. , 35 parts of ethyl acrylate, 27 parts of methacrylic acid, and 2 parts of benzoyl peroxide were added dropwise, followed by addition of the resole-type phenol resin solutions (D), (E) and dimethylaminoethanol, and the mixture was 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 A 4-necked flask was charged with and under a nitrogen stream. 100
The mixture was heated to 0 ° C. and completely dissolved to obtain a 60% epoxy resin solution (F) having a number average molecular weight of 2900 and epoxy groups 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 4 to 4 flasks were charged with to 100 under nitrogen flow.
Heated to ℃, completely dissolved, 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
Ion-exchanged water was adjusted in the same manner as in Example 9 except that (D) was excluded to obtain an aqueous dispersion having a solid content of 25%. Comparative Examples 5 to 8 All were carried out in the same manner as in Example 1 except that the composition in Example 1 was changed to the composition shown in Table 4, and the solid content was 25%.
A water dispersion of 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]

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

Performance test The storage stability test results of the water-based coating compositions obtained in Examples 1 to 12 and Comparative Examples 1 to 10 were applied to a tin plate with a bar coater so as to have a thickness of 10 μm, and the temperature was 200 ° C. Tables 5 and 6 show the results of evaluation of various physical properties by baking for 5 minutes to prepare a test panel. The various test methods in Table 5 are as follows. (1) Storage stability of paint: Stored in a thermostat at 50 ° C, and periodically evaluated the appearance and properties. 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 make 11 cuts in each of the vertical and horizontal directions. The number of unpeeled parts of the crevices when strongly peeled with a cellophane adhesive tape having a width of 24 mm adhered is shown in the molecule. (3) Water resistance: Treated in water at 125 ° C. for 40 minutes to judge the surface condition of the coating film. (4) Workability: A special goby folding type DuPont impact tester is used to place a double-folded sample at the bottom, and a 1 Kg iron weight with a flat contact surface is dropped from a height of 50 cm. The length of cracks in the coating film at the bent portion was measured.

0 to 10 mm ··· ○ mark 10 to 20 mm ··· Δ mark 20 mm or more ··· × mark (5) Corrosion resistance: A knife was used to make a cut mark on the coating film surface. The test piece is treated in 1% saline solution at 125 ° C. for 40 minutes to determine the degree of corrosion in the vicinity of the mark X. No abnormality ・ ・ ・ ・ ○ Mark slightly corroded ・ ・ ・ ・ △ mark Marked corrosion ・ ・ ・ ・ × mark

[0039]

[Table 5]

[0040]

[Table 6]

[0041]

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

Claims (1)

[Claims] 1. A polymer epoxy resin (A) having a number average molecular weight of 9000 or more and containing 0.5 or more epoxy groups per molecule (A) 20 to 90% by weight, and a carboxyl group-containing acrylic polymer (B) 7 to 50 wt%, resol type phenolic resin (C) 2 to 30 wt%, (A) to (C) as constituents, ammonium salt and / or amine salt of the reaction product of (A) and (B), And a resol type phenol resin (C) is used.