JPH05148449A - Method for coating metal material - Google Patents

Abstract

PURPOSE:To carry out the subject coating for providing coated steel plate for high processing, having excellent bending processing and scratch resistance by coating a specifically treated metal material with a specifically mixed primer composition, baking, drying and topcoating. CONSTITUTION:A metal material subjected to plating treatment to precipitate 2-500mg/m<2> one or more of iron, cobalt and nickel and/or chemical treatment with a phosphate or chromate is coated with a composition obtained by blending (A) a primary hydroxyl-containing lactone modified urethanized epoxy ester resin having 6,000-12,000 number-average molecular weight with (B) a resol type phenol resin, (C) (i) strontium chromate pigment or (ii) the component (i) and <= the weight of the component (i) of calcium chromate pigment and (D) pH adjusting pigment in ratios of the component A/the component C of 95/5-70/30 (weight ratio) and 25-50wt.% component C and 5-15wt.% component D in the nonvolatile components of coating material, baked and dried to carry out the objective coating.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for coating a metal material, and more particularly, to a mixed system of a lactone-modified urethane-modified epoxy ester and a phenol resin, which has a high concentration of an anticorrosive pigment and p.
The present invention relates to a method for coating a metallic material using a bake-curable primer composition for a highly corrosion-resistant metallic material containing an H-adjusting pigment.

[0002]

2. Description of the Related Art Conventionally, it is known that a chromate pigment is added to improve the anticorrosive ability of a primer for a metal material, and as a general concept, increasing the compounding amount of the chromate pigment increases the anticorrosive ability. Has been thought to lead to.

However, when the amount of chromate pigment is increased in ordinary paint resins, water resistance, wet adhesion resistance, blister resistance, and coating adhesion are deteriorated, and the content must be reduced rapidly. It was With respect to this point, the primer compositions using various kinds of novel resins that have been proposed so far have the same difference. For example, JP-A-57-3
No. 0717 proposes a primer composition for a metal material using a urethanized epoxy ester, but the compounding amount of the chromate pigment is about 13 to 22% by weight, which is inferior in water resistance. In No. 87044, a chromate pigment and calcium carbonate are blended in a precoat composition for an aluminum-plated steel sheet using epoxy, polyester, phenoxy, urethane, etc. Since it coexists, it has a drawback that the water resistance is lowered. In addition, JP-A-58
No. 120784 discloses a system using epoxy and epoxy urethane, but in the examples, the chromate pigment content is only 23% by weight. 10 to 10 salt pigments
It was suppressed to about 25% by weight.

[0004]

Therefore, a binder resin having excellent wet adhesion resistance is selected to improve the coating film anticorrosion ability by improving the adhesion of the coating film, and further increase the chromate pigment concentration. It is an object of the invention to provide a coating method in which a primer composition effective for various metal materials is applied on the metal material.

It is another object of the present invention to obtain a coated steel sheet for high working which has improved adhesion at the time of bending and good scratch resistance by such a coating method.

[0006]

According to the present invention, the above objects are (a) a lactone-modified urethane-modified epoxy ester resin (C) having a number average molecular weight of 6,000 to 12,000 primary hydroxyl groups (C) (b). Resole type phenolic resin (D) (c) Strontium chromate pigment or a mixture of strontium chromate pigment and calcium chromate pigment less than the weight of the pigment, and (d) pH adjusting pigment, which comprises resin (C) and resin (D)
Of 95/5 to 70/30, and the strontium chromate pigment or the mixed pigment of strontium chromate and calcium chromate is 25% in the nonvolatile content of the paint.
Plating treatment and / or phosphoric acid for precipitating at least one heavy metal of iron, cobalt and nickel with a primer composition for a metal material containing 50 to 50% by weight and a pH adjusting pigment in the nonvolatile content of the coating in an amount of 5 to 15% by weight. It can be achieved by a coating method in which it is applied onto a metal material that has been subjected to a chemical conversion treatment with salt or chromate, baked and dried, and then overcoated.

Conventionally, a urethane vehicle epoxy ester and a melamine resin have been mainly used as a resin vehicle of a primer composition for a metal material, but in the present invention, a combination of a lactone-modified urethane urethane ester and a phenol resin described later is used. Be done.

The lactone-modified urethanized epoxy ester used in the present invention has been found to be particularly effective as a resin for a primer of a pre-coated metal which is excellent in boiling water resistance, wet adhesion and excellent in adhesion to a top coat. The patent application was filed as Japanese Patent Application No. 60-45275 (filed on March 7, 1985). As specified in the specification of the application, such a resin can be conveniently produced by the following method. That is, first, any epoxy resin component having a hydroxyl group is used.

[Chemical 2] (In the formula, R is H or CH ₃ ; -A- is = C (CH ₃ ) ₂ ,
A resin represented by —CH ₂ —, —O—, —SO ₂ — or —S—; n is an integer of 0 or 14) may be used, and specific examples thereof include Toto Kasei Co., Ltd., trade name. "Epotote YD-017", "Same YD-014", "Same YD-017"
011 "," YD-128 ", manufactured by Dainippon Ink and Chemicals Incorporated, trade name" Epiclon 4050 "and the like are listed, and these may be used alone or in an amount of 50% by weight or less of another epoxy resin (for example, poly. Alkylene glycol glycidyl ether, etc.). If the substitution ratio exceeds 50% by weight, the corrosion resistance, water resistance, adhesiveness, chemical resistance, curability, etc. tend to decrease.

[0009] resin to be used in the present invention, first the epoxy resin (a ₁₎ to the dicarboxylic acid (a ₂₎ and secondary amine (a ₃₎ but are reacted dicarboxylic acid having a primary hydroxyalkyl group (a ₂ ), For example, polymethylene dicarboxylic acid (adipic acid, azelaic acid, sebacic acid, etc.), aromatic dicarboxylic acid (phthalic anhydride,
Phthalic acid, isophthalic acid, terephthalic acid, etc.), dimer acid, polybutadiene dicarboxylic acid, polyester dicarboxylic acid, etc., and one or more of them are used. In particular, polymethylene dicarboxylic acid is preferable in terms of processability, solubility and compatibility, and azelaic acid is most preferable, and trivalent carboxylic acids may be used in combination with such a ₂ component.

By reacting such a dicarboxylic acid with an epoxy resin having a hydroxyl group, the epoxy ring is opened and the acid is incorporated into the resin through an ester bond.
In this case, for example, it is preferable to use an amine catalyst, in the present invention is particularly secondary amine (a 3 ₃₎ is selected and used having primary hydroxyl groups, the primary hydroxyl is incorporated the amine itself into the resin together with catalysis Will give a group. Examples of the secondary amine (a ₃ ) to be used include dialkanolamines (diethanolamine, dipropanolamine, dibutanolamine, etc.), alkylalkanolamines (ethylethanolamine, etc.), and the like. Use two or more types. Particularly, dialkanolamine is preferable, and diethanolamine is most preferable.

The reaction is carried out by melting the epoxy resin or dissolving it in a suitable non-reactive solvent, then adding the dicarboxylic acid component and the catalyst component, and if necessary under N ₂ gas, usually 80 to 20.
The reaction may be carried out by heating at 0 ° C for 1 to 15 hours. Therefore, the epoxy resin having the dicarboxylic acid component incorporated therein has, in addition to the hydroxyl group of the raw material epoxy resin, a hydroxyl group formed by the reaction of a carboxyl group and a glycidyl group and a primary hydroxyl group of an alkanolamine.

In order to maximize the effects of the present invention, the epoxy ester resin is

[Chemical 1] The cyclic ester compound represented by (n is an integer of 4 to 10) is reacted, and the lactone is opened at the primary and secondary hydroxyl groups and incorporated by an ester bond. This lactone-modified epoxy ester resin is designated as [A].

As the above-mentioned cyclic lactone compound (Chemical Formula 1), for example, ε-caprolactone, ζ-enanthlactone, η-caprylolactone, or a ring-substituted product thereof is used. Particularly preferred lactone has 6 to 8 carbon atoms. belongs to.

In this reaction, it is preferable to use a tin compound, an organic salt of lead or manganese (a ₅ ) as a catalyst. Particularly preferable catalysts are chemical formula 3, chemical formula 4, and chemical formula 5.

[Chemical 3]

[Chemical 4]

[Chemical 5] (In the formula, X is an alkyl group, an aryl group, an aralkyl group,
Allyloxy group; X'is alkyl group, aryl group, aralkyl group, acyloxy group, halogen, hydroxyl group, X ''
Is a halogen atom), for example, stannous chloride, tetraphenyltin, tetraoctyltin, diphenyltin dilaurate, tri-n-butyltin hydroxide, tri-n-butyltin acetate, dimethyltin oxide, There are dibutyltin oxide, dilauryltin oxide, di-n-butyltin dichloride, dioctyltin dichloride and the like. Organic salts of lead or manganese include lead acetate, manganese acetate, 2-ethylhexane lead acetate,
Examples include lead salicylate and lead benzoate.

Lactone modified epoxy ester resin [A]
The lactone portion in the resin imparts flexibility to the resin in a state of being bonded to the ester chain. However, the present inventors have found that this amount of lactone affects not only the softening of the coating film but also the wet adhesion property, and if it is less than 1% by weight in the resin, satisfactory wet adhesion property cannot be obtained, while on the other hand, 30% by weight. It has been confirmed that if it exceeds the above range, the softening tends to be excessive, and the performance such as chemical resistance and moisture resistance tends to deteriorate. Therefore, the amount of lactone may be in the range of 1 to 30% by weight of the resin. Particularly preferred.

Next, the partially blocked polyisocyanate compound [B] is reacted with the epoxy ester resin [A]. The compound [B] is a polyisocyanate compound (b ₁ ) and an isocyanate protecting agent. (B ₂ ) and the number of isocyanate groups in (b ₁ ) / (b
It can be obtained by reacting in a ratio such that the ratio of the number of active hydrogen groups in ₂ ) is 5/1 to 5/4. This reaction is usually at room temperature to 150 ° C in a solvent-free or heat-reactive solvent.
However, after the component (b ₁ ) is dissolved in a non-reactive solvent and heated to 50 to 100 ° C., the solution of the component (b ₂ ) or a suitable non-reactive solvent is added dropwise to the reaction. It is preferable that it is used in view of the quality of the product [B] and the reaction control.

Examples of the polyisocyanate compound (b ₁ ) include aliphatic or alicyclic diisocyanate compounds (hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, etc.), aromatic diisocyanate, etc. Isocyanate compounds (tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, etc.), triisocyanate compounds and the like can be mentioned, and one or more of these are used. In particular, an aliphatic or alicyclic diisocyanate compound is preferable from the viewpoint of solubility, compatibility and processability of the obtained resin.

The above-mentioned isocyanate protecting agent (b ₂ ) is b
_The adduct formed by addition to _one component of the isocyanate group must be stable at room temperature and must dissociate when heated to 140 to 250 ° C. to regenerate the free isocyanate group. Examples of such a protective agent include lactam-based protective agents (ε-caprolactam, γ
-Butyrolactam, etc.), oxime-based protective agents (methyl ethyl ketoxime, cyclohexanone oxime, etc.) alcohol-based protective agents (methanol, ethanol, isobutyl alcohol, etc.), and phenol-based protective agents (phenol, para-tert-butylphenol, cresol, etc.).

The resin [C] according to the present invention can be produced very conveniently by reacting the product [A] with the product [B]. In this case, the reaction ratio is such that the ratio of the number of primary hydroxyl groups contained in the product [A] / the number of free isocyanate groups contained in the product [B] is 1.
The range is set to 0/1 to 10/8, preferably 10/1 to 10/6. The above reaction is usually N
It is carried out at a temperature of 50 to 150 ° C. under ₂ gas until the isocyanate group is substantially absent. In some cases, the reaction may be stopped by adding a primary alcohol, for example, when the molecular weight reaches a desired value even if the isocyanate group remains.

The number average molecular weight of the urethanized epoxy ester resin having a primary hydroxyl group produced in this manner is suitably 6,000 to 12,000. When the molecular weight is less than 6,000, the bending property and the corrosion resistance decrease, while
If it exceeds 2,000, the paint will gel. This adjustment of the molecular weight is mainly performed by the molecular weight of the epoxy ester main chain, and the ratio of g equivalent of glycidyl group of epoxy resin (a ₁ ) / g equivalent of carboxyl group of polyvalent carboxylic acid (a ₂ ) is 1.1 to. 1.4, preferably 1.15 to 1.25, and the acid value of the reaction product of (a ₁ ) and (a ₂ ) is 2 (KOHmg / g) or less, preferably 1 ( KO
It is preferable to complete the reaction so that the amount becomes Hmg / g) or less.

Such a lactone-modified urethane-modified epoxy ester resin contains a primary hydroxyl group having excellent reactivity in the molecule, and has excellent adhesion, processability, corrosion resistance, water resistance and chemical resistance which have been conventionally required. Contributing to the provision of coatings for primers.

By incorporating the lactone component, not only a primary hydroxyl group is imparted, but also the methylene chain of the lactone component improves the adhesiveness due to the relaxation of internal stress, the wet adhesion and the boiling water resistance. Combined with high solidification and good low-temperature curing characteristics, it is extremely suitable as a primer for precoat metal.

In the present invention, the lactone-modified urethane-modified epoxy ester resin [C] is used in combination with the resol-type phenol resin [D]. Any resol-type phenolic resin obtained by condensation reaction of phenols and formalin in the presence of alkali can be used.

[Chemical 6] (In the formula, n is 0 to 4; W is -CH _2- , or -CH
_{2 -O-CH 2} -; R is _CH 3, H or of 7)

[Chemical 7] Is a resol-type phenol resin represented by the following formula, and is a resol-type phenol resin obtained by etherifying a phenolic OH group with an alcohol such as butanol.

In the present invention, the resin [C] and the resol-type phenol resin [D] have a solid content weight ratio of 95/5.
Used at a ratio of ~ 70/30. When the amount of phenolic resin is less than this range, the blister resistance is reduced, and when it is more than this range, the processability is reduced,
Both are not preferable for the purpose of the invention. The use of such a resin vehicle contributes to the improvement of the wet adhesion resistance due to the primary hydroxyl group and the improvement of the wet adhesion resistance due to the phenol resin, which contributes to the improvement of the corrosion resistance.

The present inventors have found that even if a large amount of chromate pigment is added to the above resin vehicle, the water resistance, wet adhesion resistance and coating adhesion are not deteriorated. Therefore, in the present invention, the chromate rust preventive pigment is contained in the nonvolatile matter of the coating in an amount of 25 to 5%.
It is used in the range of 0% by weight and gives excellent corrosion resistance.

As the chromate, strontium chromate or a mixture of strontium chromate and calcium chromate (less than 50% of the mixture) is particularly effective, and therefore, they are particularly selectively used in the present invention. When using a mixture of strontium chromate and calcium chromate, the amount of calcium chromate is less than 50% of the mixture, 10% of the strontium chromate
It is preferable that the amount is in the above range, and if the amount of calcium chromate added for improving the corrosion resistance is large, the blister resistance is deteriorated, which causes an inconvenient result.

It should be noted that the chromate pigment accounts for 2% of the total nonvolatile content.
If it is less than 5% by weight or more than 50% by weight, the cathodic polarization effect is reduced and the corrosion resistance is reduced.

Further, in the present invention, the cathode polarization effect is enhanced, and the pH of the corrosion site on the metal surface of a metal, particularly zinc, is mainly measured.
A pH-adjusting pigment is added for the purpose of suppressing the change, and the pH of the composition is adjusted to the range of 6 to 11. Because p
This is because if it is less than H6, the corrosion resistance tends to result, and if it exceeds 11, the corrosion resistance and the blister property tend to deteriorate.

As the pH adjusting pigment, the solubility (JIS-
K-5101) is in the range of 0.001-5%, and any pigment effective in adjusting the pH of the saline suspension having a pH of 6-11 is used, for example barium metaborate, zinc phosphate, Calcium phosphate, calcium carbonate, zinc molybdate, calcium molybdate, aluminum dihydrogen tripolyphosphate and the like are appropriately combined and used for the above purpose. The pH adjusting pigment is 5 to 1 in the nonvolatile content of the paint.
It is used within the range of 5% by weight. The reason is that if it is less than 5%, the effect is insufficient, and if it exceeds 15%, the blister resistance tends to be deteriorated.

As described above, in the present invention, the wet adhesion resistance is improved by using the specific resin vehicle, and the cathode polarization effect is improved by mixing the relatively large amount of the rust preventive pigment and the pH adjusting pigment in the specific amounts. It is designed for maximum smoothing, and has particularly excellent corrosion resistance. For example, hot-dip galvanized steel sheet, hot-dip galvanized steel sheet, electro-galvanized steel sheet, cold-rolled steel sheet, etc. Used effectively.

It is desirable to subject a metal material to a conventional phosphate or chromate chemical conversion treatment from the viewpoints of corrosion resistance and coating film adhesion. , A nickel plating treatment for depositing at least one heavy metal of nickel,
200 mg / m ² the chemical conversion treatment by allowed to deposit excellent corrosion resistance primer composition of the present invention containing chromium Sanbosabi pigment in a large amount can be obtained even without, water resistance, chemical resistance, workability, curability Excellent in coating film adhesion,
By providing a coated plate with good scratch resistance, combining the above plating treatment and chemical conversion treatment, especially by using a metal material that has been subjected to chemical conversion treatment after plating treatment, good adhesion at the time of bending and scratch resistance It has been found that a particularly good coated plate can be obtained. Therefore, in the present invention, iron,
2 to 5 of at least one heavy metal of cobalt and nickel
To provide a coating method in which the above primer composition is applied to a metal material that has been subjected to plating treatment and / or phosphate or chromate conversion treatment to cause precipitation to 00 mg / m ² , and after baking drying, top coating is performed. Be done.

An acidic aqueous solution containing at least one metal ion of iron, cobalt and nickel is used for the plating treatment, and FeSiF ₆ , Fe (BF ₄ ) ₂ and Co are used.
SiF ₆ , Co (BF ₄ ) ₂ , NiSiF ₆ , Ni (B
The use of an aqueous solution containing one or more complex fluorides such as F ₄ ) ₂ is particularly useful for improving the adhesion.
For plating, a metal material is usually immersed in an aqueous solution of 0.1 to 50% by weight of such a heavy metal salt, or the aqueous solution is applied by spraying, if desired, washed with water, drained, and then dried. It is sufficient that this liquid contact is at room temperature to 80 ° C. for about 1 second to 10 minutes.

The present inventors have found that the amount of metal deposited is 2 mg /
If it is less than m ² , no adhesion improving effect is observed and it is 500 mg /
It has been found that even if it exceeds m ² , no remarkable improvement is obtained and it is uneconomical, so that it can be appropriately selected within the range of ^{2 to} 500 mg / m ² . This plating treatment, which significantly improves the adhesion at the time of bending, the coin scratching property, etc., is a galvanized steel plate for high processing, that is, a steel plate that does not have plating cracks at the 180 ° bending processing site, or has little cracking, for example, It is particularly useful for a steel sheet having a low basis weight of 180 g / m ² (both sides) or less or an ultra-low lead zinc plated steel sheet produced from a plating bath having an extremely low lead component concentration.

The primer composition according to the present invention is usually applied to a metal material which has been subjected to plating treatment and / or usual phosphate treatment or chromate treatment to a dry film thickness of about 3 to 10 μm. .. If the primer film thickness is less than 3 μm, the scratch resistance, adhesion and corrosion resistance tend to decrease, and if it exceeds 10 μm, the adhesion tends to decrease. When applying the primer composition, an appropriate coating method such as spraying, roll coating, and shower coating is adopted, and the temperature is 250 ° C. or lower, preferably 180 ° C.
Bake-drying is performed at ˜250 ° C.

In the present invention, the top coating material is then applied by a conventional method to produce a coated plate excellent in workability, corrosion resistance and scratch resistance. As already mentioned, as the pretreatment of the metal material, both plating treatment and chemical conversion treatment are used.
By performing the plating treatment alone or the chemical conversion treatment after the plating treatment, it is possible to easily obtain a coated plate which is excellent not only in corrosion resistance but also in coating film adhesion, workability, and scratch resistance.

The present invention will be described below with reference to examples. Unless stated otherwise, parts and percentages are by weight.

[0037]

Example 1 Preparation of primer coating (a) Lactone-modified urethane-modified epoxy ester (resin C) Separately described manufacturing method 28 parts as non-volatile content (parts by weight, the same below) (b) Resol-type phenol resin (resin B) as BKS -316 (manufactured by Showa High Polymer Co., Ltd.) 7 parts as a non-volatile component (c) Strontium chromate pigment 40 parts (d) Zinc phosphate pigment 10 parts (e) Titanium oxide 15 parts (f) Cyclohexanone (solvent for viscosity adjustment) ( After adding (c), (d) and (e) to the resin solution of a) and thoroughly kneading using a three-roll, the resin of (b) was added,
The solvent of (f) is added to appropriately adjust the viscosity to obtain a coating composition.

Preparation of test coated plate Hot dip galvanized steel sheet treated with zinc phosphate coating (zinc basis weight 250 g / m ² (both sides), zinc phosphate coating amount 1 g /
m ² and plate thickness 0.35 m / m) was coated with the above-mentioned primer paint. (Dry film thickness 5μ, maximum plate temperature (PMT) 22
(0 ° C, baking time 60 seconds) Then, a polyester-based topcoat paint and each of our product Superlac DIFOX-97 paints were applied. (Dry film thickness 12 μ, PMT 210 ° C.) The coated steel sheet is subjected to the following tests to evaluate the performance,
The results are shown in Table 1.

Test method Bending workability Two sheets having the same plate thickness are sandwiched in between, and the temperature is 20 ° C.
Judgment is made from the tape peeling condition of the processed part to be pressure-bonded with vise. (2TT) (Judgment Criteria Separately) Water Blistering Property The test coated plate is immersed in a boiling water bath for 8 hours and judged by the presence or absence of blistering on the coated surface. Salt spray resistance test A test piece with a cut up to the base was tested with a salt spray tester (JIS-Z-2371), and 10
After 00H, the cut portion is peeled off with tape.

Evaluation Criteria Folding tape peeling ◎ No peeling (with practicality) ○ Peeling 1-2 points (with practicality) △ Slight peeling (with practical problems) × Peeling more than half (with practical problems) JIS- K-5400 paint water resistance test by general test method (by visual inspection after immersion for 8 hours) ○ No abnormalities (with practicality) △ Luster (with practical problems) × Blister (with practical problems) Salt water spray resistance test ◎ Peeling width 0 mm ○ 1.0 mm or less △ 1.1 to 2.0 mm × 2.1 mm or more

[0041]

Examples 2 to 8 and Comparative Examples 1 to 8 In the same manner as in Example 1, except that the primer was changed to the composition shown in the table to prepare a test piece.

The same tests as in Example 1 were carried out using each test piece to evaluate the performance, and the results are shown in Tables 1 to 6. Resin C: ε-caprolactone-modified urethane-modified epoxy ester resin (separate sheet of manufacturing method) Resin B: Resol-type phenol resin BKS-316
(Showa High Polymer Co., Ltd.) Strontium chromate: Strontium chromate N (Kikuchi dye industry
KK Calcium chromate: Calcium chromate D (Kikuchi Dye Industry Co., Ltd.) Zinc phosphate: Sicor Zmp / S (BASF) Titanium oxide: Titanium CR-91 (Ishihara Sangyo KK)
Made) Calcium carbonate: heavy carbon N (made by Maruo Calcium Co., Ltd.) Aluminum tripolyphosphate dihydrogen: K-white
82 (manufactured by Teikoku Kako Co., Ltd.
Product) Urethaned Epoxy Ester Resin: Attached Sheet Methoxymethylated Melamine: Cymail 303 (A
(Manufactured by CC)

Production Method of Resin C Epoxy resin (trade name "Epototo YD- manufactured by Tohto Kasei Co., Ltd.
014 ", epoxy equivalent 950) 475 parts were dissolved in 95 parts xylol and 119 parts cellosolve acetate, 39.2 parts azelaic acid and 8.3 parts diethanolamine were added, and the mixture was reacted at 145 ° C for 6 hours to give a resin solid content. Has an acid value of 1.1 KOHmg / g and the temperature of the solution is 10
When the temperature reached 0 ° C, 105 parts of Braxel M (trade name ε-caprolactone manufactured by Daicel Chemical Industries, Ltd.) and 0.3 part of stannous chloride were added, and then the temperature was raised to 140 ° C. Sequential sampling is performed while keeping the temperature at this temperature, the amount of unreacted ε-caprolactone is traced by IR, and the reaction is terminated when the reaction rate reaches 98% or more. After the reaction was completed, 209 parts of xylol and 130 parts of methyl ethyl ketone were added,
The product [A-1] is obtained by cooling.

Separately, isophorone diisocyanate 222
After dissolving 222 parts of cellosolve acetate and heating it to 80 ° C., a solution of 113 parts of ε-caprolactam and 113 parts of cellosolve acetate is added dropwise over 1 hour to react. After completion of dropping, the temperature is 80 ° C for 3 hours.
The reaction was completed while keeping the temperature at room temperature and the isocyanate equivalent was 6
70 g equivalent of product [B] is obtained.

Next, 55.9 parts of the product [B] and 118 parts of cellosolve acetate were added to the above product [A-1], and after reacting at 100 ° C. for 3 hours, 102 parts of isopropyl alcohol were added and cooled. To obtain a thermosetting resin solution [C]. The lactone content in this resin solid component is 1
6% by weight.

Production Method of Urethane Epoxy Ester Resin Epoxy resin (trade name "Epototo YD" manufactured by Tohto Kasei Co., Ltd.
-014 ", epoxy equivalent 950) 475 parts were dissolved in 95 parts xylol and 119 parts cellosolve acetate, 39.2 parts azelaic acid and 8.3 parts diethanolamine were added, and the mixture was reacted at 145 ° C for 6 hours to obtain a resin solid form. When the acid value of the component became 1.1 KOHmg / g, 209 parts of xylol and 130 parts of methyl ethyl ketone were added and cooled to obtain the product [A-2].

3 Next, 55.9 parts of the product [B] and 118 parts of cellosolve acetate were added to the above product [A-2], and after reacting at 100 ° C. for 3 hours, 102 parts of isopropyl alcohol were added. Then, it is cooled to obtain a thermosetting resin solution.

[0048]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[0049]

Example 9 Preparation of Test Coated Plate Commercially available hot-dip galvanized steel sheet for high processing [0.50 m / m,
Coating weight 90 g / m ^{2 on} both sides] coating type chromate film treatment (Chromate treatment agent made by Nippon Paint Co., Ltd. non-rinse coat 300, amount of chromium deposited in dry film (metal conversion) 40
mg / m ²⁾ and outer using primer coating of Example 3 to that was the primer coating and topcoating the same manner as in Example 1. The evaluation results are shown in Table 7.

[0050]

Example 10 Preparation of Test Coated Plate The steel plate of Example 9 was treated with a nickel silicate solution (0.2 g equivalent /
1) at 50 ° C for 5 seconds, washed with water and dried with hot air (100
After nickel plating by the method (° C. × 1 minute) (nickel adhesion amount 15 mg / m ^{2 on} one side), chromate treatment was performed in the same manner as in Example 9, followed by primer coating and top coating. The results are shown in Table 7.

[0051]

Example 11 Preparation of test coated plate Hot-dip galvanized steel sheet containing 5% aluminum [0.40 m
/ M, basis weight 250 g / m ^{2 on} both sides] is immersed in an iron tetrafluoride solution (0.2 g equivalent / 1) at 50 ° C for 15 seconds, washed with water, and dried with hot air (100 ° C x 1 minute) for iron plating. After that (iron adhesion amount 10 mg / m ^{2 on} one side), primer coating and top coating were carried out in the same manner as in Example 9 without chromate treatment. The results are shown in Table 7.

[0052]

[Table 7]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B05D 7/24 302 S 8616-4D U 8616-4D C09D 5/00 PPF 6904-4J 5/08 PPX 6904-4J PQE 6904-4J (72) Inventor Shinji Nakano 19-17 Ikedanaka-cho, Neyagawa City, Osaka Prefecture Japan Paint Co., Ltd.

Claims (4)

[Claims] 1. At least one of iron, cobalt and nickel
(A) a number average molecular weight of 6,000 to 12,000 on a metal material that has been subjected to a plating treatment for precipitating a heavy metal of ² to 500 mg / m ² and / or a chemical conversion treatment with a phosphate or chromate. Lactone-modified urethane esterified epoxy ester resin having a primary hydroxyl group (C) (b) Resol-type phenol resin (D) (c) Strontium chromate pigment or a mixture of a strontium chromate pigment and a calcium chromate pigment having a weight less than the pigment weight, and (d) ) A resin (C) and a resin (D) composed of a pH adjusting pigment
Of 95/5 to 70/30, and the strontium chromate pigment or the mixed pigment of strontium chromate and calcium chromate is 25% in the nonvolatile content of the paint.
Is applied to a primer composition for metal materials, characterized in that the content of the pH adjusting pigment is 5 to 15% by weight in the nonvolatile content of the coating composition, and after baking and drying, topcoating is performed. How to paint metal materials. 2. A lactone-modified urethanized epoxy ester resin (C) having a primary hydroxyl group is converted into a reaction product of an epoxy resin having a hydroxyl group, a dicarboxylic acid and a secondary amine having a primary hydroxyalkyl group. Chemical 1] The product (A) obtained by reacting a cyclic ester compound represented by (n is an integer of 4 to 10), a polyisocyanate compound, and an isocyanate protecting agent, the number of isocyanate groups / activity in the protecting agent. A block isocyanate compound (B) obtained by reacting so that the ratio of the number of hydrogen is 5/1 to 5/4 is included in the number of primary hydroxyl groups of the secondary amine / the compound (B). The method according to claim 1, which is obtained by reacting so that the ratio of the number of free isocyanate groups to be obtained is 10/1 to 10/8. 3. The method according to claim 1, wherein the metal material is a galvanized steel sheet or an aluminum-zinc alloy hot-dip steel sheet. 4. A heavy metal deposition plating process is performed, and then,
The method according to claim 1, wherein the chemical conversion treatment is performed.