JP2001172560A - Self-precipitating coating composition, process for coating metal surface and coated metal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition which may impart an excellent corrosion resistance, adhesivity and heat resistance to metal surfaces, a process for coating metal surfaces and a coated metal material. SOLUTION: The aqueous self-precipitating coating composition contains a water-dispersible or water-soluble organic resin, an acid, an oxidizing agent and/or a metal ion, wherein the organic resin is an anionic polyester resin comprising a polyhydric alcohol component (a) and an acid component (b). In the process for coating metal surfaces, this composition is used. The coated metal material is prepared using this.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a coating composition which can impart excellent corrosion resistance, adhesion and heat resistance to a metal surface,
The present invention relates to a metal surface coating method and a coated metal material. More particularly, the invention relates to metal surfaces, for example, iron,
Zinc-plated or water-dispersible or water-soluble organic resin such as aluminum, acid, oxidizing agent and / or
Alternatively, after contacting with an aqueous self-precipitating coating composition containing metal ions to form an uncured organic resin film on the metal surface, washing with water, and then heating and drying, excellent corrosion resistance and adhesion to the metal surface TECHNICAL FIELD The present invention relates to an autodeposition coating composition for imparting heat resistance and heat resistance, a coating method, and a coated metal material.

[0002]

2. Description of the Related Art An aqueous coating composition capable of forming an organic resin film on the metal surface by bringing the metal surface into contact with an acidic coating composition containing an organic resin,
Known as a self-deposition type coating composition,
No. 17630, Japanese Patent Publication No. 52-21006,
JP-B-54-13435, JP-A-61-16867
No. 3 publication. A feature of the conventionally known coating composition is that an organic resin film whose thickness or weight increases with immersion time can be formed by immersing a clean metal surface in the coating composition. Further, this film formation is caused by the chemical action of the coating composition on the metal surface (metal ions eluted from the metal surface by etching act on the resin particles and precipitate on the metal surface).
Thus, a resin film can be effectively formed on a metal surface without using external electricity like electrodeposition. Further, there is an advantage that a pretreatment such as a phosphate treatment is not required, and a treatment step can be shortened as compared with an electrodeposition coating method or the like.

However, various means have been developed to improve the corrosion resistance and adhesion of an organic resin film formed on a metal surface because the conventional known coating compositions have insufficient corrosion resistance and adhesion. For example, US Pat. No. 3,795,546 describes a chemical treatment (post-treatment) of an uncured organic resin film.
The number of corrosion resistance after drying of the organic resin film is determined by contacting the uncured organic resin film with an aqueous solution containing about 2.5 to 50 g / L of hexavalent chromium and polyacrylic acid before heating and drying the uncured organic resin film. Improvements are disclosed. However, harmful hexavalent chromium is used in the treatment process,
Wastewater treatment is troublesome and costly, and the formed organic resin film also contains hexavalent chromium, which is not preferable in terms of environment and safety. Japanese Patent Publication No. 3-5055841 discloses a method in which a metal surface is treated with an aqueous coating composition containing a vinylidene chloride-based resin as a main component, and an uncured resin film is heated and dried with an aqueous solution containing an alkaline substance before drying. A metal surface coating treatment capable of further improving the corrosion resistance of a vinylidene chloride-based resin by contacting the same is disclosed. However, this treatment has the advantage of not using hexavalent chromium which is harmful to the chemical treatment for imparting excellent corrosion resistance and adhesion to the organic resin film formed on the metal surface. The component is a vinylidene chloride resin and has excellent corrosion resistance but poor heat resistance.For example, it is difficult to apply it to parts around the engine of a car where heat is applied. However, there is a drawback that the range of application such as difficulty is limited, and the above chemical treatment is indispensable to impart adhesion. At present, a method for coating a metal surface having excellent corrosion resistance, adhesion and heat resistance has not been obtained.

[0004]

DISCLOSURE OF THE INVENTION The present invention simultaneously provides excellent corrosion resistance, adhesion and heat resistance to a metal surface such as iron, galvanized or aluminum without performing a chemical treatment (post-treatment). It is an object of the present invention to provide a self-deposition type coating composition for forming an organic resin film which can be formed, and a method for coating a metal surface.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on means for solving the problems of the prior art, and as a result, have found that a metal surface can be formed of a water-dispersible or water-soluble organic resin containing a water-soluble organic resin. Upon treating the metal surface with a self-deposition type coating composition, the organic resin was found to be able to solve the above-mentioned problems by treating the metal surface with a coating composition comprising an anionic polyester resin, The present invention has been completed.

That is, the present invention relates to an aqueous self-precipitating coating composition containing a water-dispersible or water-soluble organic resin on a metal surface, an acid, an oxidizing agent and / or a metal ion. Is a polyhydric alcohol component (a)
A self-precipitating coating composition, characterized by being an anionic polyester resin comprising a condensate of carboxylic acid and an acid component (b).

The present invention also relates to the present invention, wherein the polyhydric alcohol component (a) comprises at least one selected from the group consisting of an aliphatic polyhydric alcohol derivative (a) -1 and an aromatic polyhydric alcohol derivative (a) -2. The acid component (b) is an aliphatic carboxylic acid derivative (b) -1, an aromatic carboxylic acid derivative (b) -2, an aromatic acid anhydride derivative (b) -3, (b)
And at least one autodeposition coating composition selected from the group consisting of naphthalene derivative (b) -5.

Further, the present invention provides an aromatic carboxylic acid derivative (b) -2 and an aromatic acid anhydride derivative in which the acid component (b) contains a carboxyl group or a salt thereof, or a sulfonic acid group or a salt thereof. (B) An autodeposition coating composition containing at least one member selected from the group consisting of -3.

Further, the coating composition is brought into contact with a metal surface to form an uncured organic resin film on the metal surface, washed with water, and then dried by heating to form an organic resin film on the metal surface. Provided are a method for coating a metal surface, and a coated metal material.

Hereinafter, the configuration of the present invention will be described in detail. The coating composition and coating method of the present invention are suitable for treatment on a metal surface, for example, a metal surface such as iron-based, galvanized or aluminum, particularly an iron-based metal surface.

The self-deposition type coating composition used in the present invention comprises:
It contains a water-dispersible or water-soluble organic resin, an acid, an oxidizing agent and / or a metal ion. The organic resin of the present invention is a polyester resin comprising a condensate of a polyhydric alcohol component (a) and an acid component (b), and has an anionic property. The polyester resin used in the present invention contains 100 mol% of the polyhydric alcohol component (a).
And 100 mol% of the acid component (b).

The polyhydric alcohol component (a) used in the polyester resin used in the present invention is not particularly limited, but at least one selected from the group consisting of (a) -1 and (a) -2 is used. Can be used.

[0013]

Embedded image (A) -1 is an aliphatic polyhydric alcohol derivative represented by the general formula (1), and in the general formula (1), R ₁ is
It is a linear or branched alkylene having 1 to 10 carbon atoms, or alkylene containing a hydroxyl group and / or a halogen element in a part of the alkylene.

Specific examples of the aliphatic polyhydric alcohol derivative (a) -1 include ethylene glycol, neopentyl glycol, dibromoneopentyl glycol, 1,2-propanediol, 1,3-propanediol, 3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, -Methyl-1,3-propanediol, 2,2-diethyl-
Examples include 1,3-propanediol, glycerin, pentaerythritol, trimethylolethane, and trimethylolpropane.

[0015]

Embedded image (A) -2 is represented by the general formula (2), and in the general formula (2), m and n are integers of 1 or more, and 2 ≦ m + n ≦ 6.
It is. R ₂ , R ₃ , R ₄ , and R ₅ are each independently at least one selected from hydrogen and —CH ₃ .

(A) -2 is an aromatic polyhydric alcohol derivative, specifically, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol F ethylene oxide adduct, bisphenol F propylene oxide adduct And the like. Further, diethylene glycol, dipropylene glycol and the like may be contained as necessary as a polyhydric alcohol component. The polyhydric alcohol component preferably includes those in which R _{1 in the} general formula (1) is a branched alkylene. It is more preferable that neopentyl glycol be contained in an amount of at least 5 mol% or more based on all polyhydric alcohol components from the viewpoint of corrosion resistance and adhesion.

The acid component (b) used in the polyester resin used in the present invention is not particularly limited.
At least one selected from the group consisting of -1, (b) -2, (b) -3, (b) -4, and (b) -5 can be used.

[0018]

Embedded image (B) -1 is represented by the general formula (3). In the general formula (3), X ₁ and X ₂ are each independently hydrogen, carbon atom 1
It is at least one selected from alkyl groups of 10 to 10.

R ₆ is a straight-chain or branched-chain alkylene having 1 to 30 carbon atoms, or a part of the above-mentioned alkylene, in which —COOX ₃ (here, X ₃ is hydrogen, and has 1 to 1 carbon atoms).
Alkylene).

(B) -1 is an aliphatic carboxylic acid derivative, specifically, succinic acid, methyl succinic acid, ethyl succinic acid, butyl succinic acid, monomethyl succinate, dimethyl succinate, monoethyl succinate, Diethyl succinate, monobutyl succinate, dibutyl succinate, glutaric acid,
Methyl glutaric acid, ethyl glutaric acid, butyl glutaric acid, glutaric acid monomethyl ester, glutaric acid dimethyl ester, glutaric acid monoethyl ester, glutaric acid diethyl ester, glutaric acid monobutyl ester,
Glutaric acid dibutyl ester, adipic acid, adipic acid monomethyl ester, adipic acid dimethyl ester, adipic acid monoethyl ester, adipic acid diethyl ester, adipate dioctyl ester, sebacic acid, sebacic acid diethyl ester, sebacic acid dibutyl ester, dibacyl sebacate Esters, tricarballylic acid, butenetetracarboxylic acid and the like can be mentioned.

[0021]

Embedded image(B) -2 is represented by the general formula (4).
Then X₄, X₅Are independently of each other hydrogen, carbon number 1
It is at least one selected from alkyl groups of (1) to (3).
Y₁, Y₂, Y₃, Y₄Are independently of each other hydrogen, -C
OOX₆(Where X₆Is hydrogen, alkyl having 1 to 3 carbons
Group, Na, K, Ca, Ba, Li, NH ₄), -SO₃
Z₁Is (where Z₁Is hydrogen, Na, K, Ca, B
a, Li, NH₄) Is at least one selected from
You.

(B) -2 is an aromatic carboxylic acid derivative, specifically, terephthalic acid, terephthalic acid monomethyl ester, terephthalic acid dimethyl ester, terephthalic acid monoethyl ester, terephthalic acid diethyl ester, isophthalic acid, isophthalic acid Acid monomethyl ester,
Isophthalic acid dimethyl ester, isophthalic acid-5-sulfonic acid, isophthalic acid-5-sulfonic acid salt (Li salt,
Na salt, K salt, etc.), dimethyl-5-sulfonic acid isophthalate, dimethyl-5-isophthalic acidsulfonic acid salt (Li
Salt, Na salt, K salt, Ca salt, Ba salt, NH ₄ salt, etc.), trimellitic acid, trimellitic acid 1,4-dimethyl ester, pyromellitic acid, pyromellitic acid 1,4-dimethyl ester, pyromellitic Acid tetramethyl ester, pyromellitic acid tetraethyl ester and the like.

[0023]

Embedded image (B) -3 is an aromatic acid anhydride derivative represented by the general formula (5). In the general formula (5), Y ₅ and Y ₆ are each independently hydrogen, —COOX ₇ (here, And X ₇ is hydrogen, an alkyl group having 1 to 3 carbon atoms, Na, K, Ca, B
a, Li, NH ₄ ) and —SO ₃ Z ₂ (where Z ₂ is hydrogen, Na, K, Ca, Ba, Li, NH ₄ ). (B) -3 is an aromatic acid anhydride derivative, specifically, phthalic anhydride, trimellitic anhydride, methyl trimellitic anhydride, and the like.

[0024]

Embedded image (B) -4 is an anhydride of pyromellitic acid represented by the general formula (6).

[0025]

Embedded image (B) -5 is a naphthalene derivative represented by the general formula (7). In the general formula (7), Y ₇ , Y ₈ , Y ₉ ,
And Y ₁₀ are, independently of one another, hydrogen, -COOX
₈ (where X ₈ is hydrogen or an alkyl group having 1 to 3 carbon atoms).

(B) -5 is a naphthalene derivative,
Specifically, 1,2-naphthalenedicarboxylic acid, 1,2-
Naphthalenedicarboxylic acid dimethyl ester, 1,3-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid dimethyl ester, 1,4-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid dimethyl ester, 1,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid dimethyl ester, 1,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid dimethyl ester, 1,7-naphthalenedicarboxylic acid, 1,
7-naphthalenedicarboxylic acid dimethyl ester, 2,3
-Naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid dimethyl ester, 2,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid dimethyl ester, 2,7-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid dimethyl ester And the like.

As the acid component, at least one selected from the group consisting of aromatic carboxylic acid derivative (b) -2 and aromatic acid anhydride derivatives (b) -3 and (b) -4 is used as the total acid component. On the other hand, it is preferable to contain 60 mol% or more from the viewpoint of corrosion resistance, adhesion and heat resistance.

(B) -2 and (b) -3 are represented by the general formula
In (4) and (5), Y₁~ Y ₆At least
One is -COOX_{6 '}(Where X_{6 '}Is hydrogen, N
a, K, Ca, Ba, Li, NH₄), -SO₃Z
₁(Where Z₁Is hydrogen, Na, K, Ca, Ba, Li,
NH₄) And -COOX_{7 '}(Where X_{7 '}Is hydrogen,
Na, K, Ca, Ba, Li, NH₄), -SO₃Z₂
(Where Z₂Is hydrogen, Na, K, Ca, Ba, Li,
NH₄At least one selected from the group consisting of
More preferably, the content is 40 mol% or less. Contained
If the amount exceeds 40 mol%, the corrosion resistance and the adhesion will decrease.
Further, as an acid component, a C ＝ C bond other than an aromatic ring may be used if necessary
Maleic acid, a carboxylic acid derivative having
It may contain oleic acid, fumaric acid, itaconic acid and the like.

The molecular weight of the polyester resin used in the present invention is not particularly limited, but the number average molecular weight is 3,000 to 3,000.
50,000 can be used. Polyester resin used in the present invention, using the polyhydric alcohol component and the acid component, if necessary dibutyltin oxide,
After conducting esterification or transesterification at 140 to 300 ° C. in the presence of a catalyst such as lead acetate, calcium acetate or N-butyl titanate, excess alcohol components are removed under reduced pressure of 10 mmHg or less as necessary. After cooling, the obtained condensate can be heated and melted at 60 to 90 ° C. in the presence of water, and can be obtained by adding an amine, a surfactant or the like as necessary.

The polyester resin used in the present invention essentially has an anionic property. In order to impart an anionic property, the addition of an anionic surfactant may be mentioned as the surfactant. Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl disulfate, alkyl diphenyl ether disulfonate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene aryl ether sulfate, carboxylate surfactant, phosphate surfactant, and naphthalene sulfone. Acid formalin condensate,
Examples thereof include a polycarboxylic acid type surfactant, which can be added to the extent that the condensate of the polyhydric alcohol component and the acid component can be stably dispersed in water. If necessary, a nonionic surfactant may be added as long as the object of the present invention is not impaired.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether (alkyl group; octyl,
Decyl, lauryl, stearyl, oleyl, etc.), polyoxyethylene alkylphenyl ether (alkyl group;
Octyl, nonyl, etc.), polyoxyethylene / polyoxypropylene block copolymer, and the like. Further, a water-soluble resin having a sulfonic acid group and a salt thereof, a carboxyl group and a salt thereof, a phosphate group and a salt thereof, and the like may be added.

On the other hand, in the general formulas (4) and (5), Y ₁
At least one to Y ₆ is, -COOX _{6 '(wherein} X
_{6 ′} is hydrogen, Na, K, Ca, Ba, Li, NH ₄ ),
—SO ₃ Z ₁ (where Z ₁ is hydrogen, Na, K, Ca, B
a, Li, NH ₄ ) and —COOX _{7 ′} (where X
_{7 ′} is hydrogen, Na, K, Ca, Ba, Li, NH ₄ ),
-SO ₃ Z ₂ (where Z ₂ is hydrogen, Na, K, Ca, B
a, Li, NH ₄ ), an anionic property can be imparted by containing at least one selected from the group consisting of a, Li, and NH ₄ ).

The self-deposition type coating composition of the present invention comprises a mixture of the water-dispersible or water-soluble polyester resin obtained as described above, an acid, an oxidizing agent and, if necessary, a compound capable of supplying metal ions. And it can obtain by adding water further as needed. As the acid, for example, at least one selected from zircon hydrofluoric acid, titanium hydrofluoric acid, hydrofluoric acid, borofluoric acid, hydrofluoric acid, phosphoric acid, nitric acid, and the like can be used. It is more preferred to use As the oxidizing agent, potassium permanganate, hydrogen peroxide, sodium nitrite and the like can be used, but it is more preferable to use hydrogen peroxide. The compound capable of supplying metal ions is not particularly limited as long as it is stable in the coating composition, and examples thereof include ferric nitrate, ferric fluoride, ferrous phosphate, and cobaltous nitrate. It is more preferable to use ferric fluoride.

The content of the organic resin in the aqueous coating composition used in the present invention is from 5 to 550 as a resin solids concentration.
g / L is preferable, and 50-100 g / L is more preferable. The concentration of the acid is more preferably from 0.1 to 5.0 g / L, and even more preferably from 0.5 to 3.0 g / L. The concentration of the oxidizing agent is preferably 0.01 to 3.0 g / L,
0.03 to 1.0 g / L is more preferable. When a compound capable of supplying a metal ion is used, the concentration of the metal ion is preferably 50 g / L or less, more preferably 1.0 to 5.0 g / L.

The method of coating the metal surface with the aqueous coating composition of the present invention is not particularly limited, but the dipping method is more preferable. Further, the processing temperature and the processing time are not particularly limited.
It is suitable to immerse the coating composition at a temperature of 30 to 30C, preferably 20 to 25C for 10 to 300 seconds, preferably 30 to 180 seconds. In the processing outside the above range, the object of the present invention is not achieved.

The coating amount of the coating composition of the present invention on the metal surface is not particularly limited, but is 5 to 40 μm, preferably 10 to 25 μm as the thickness of the organic resin film after drying.
Range. If the film thickness is less than 5 μm, the desired film performance cannot be obtained. On the other hand, when the thickness exceeds 40 μm, blisters are easily generated in the film, and the appearance quality is significantly impaired.

In the coating treatment of the present invention, usually before the application of the coating composition, the metal surface is degreased and washed with water to form an uncured organic resin film on the metal surface with the coating composition. Washing with water and then drying by heating. The temperature and drying time during heating and drying are not particularly limited,
Generally, in the range of 80 to 200 ° C, preferably 100 to 180 ° C, 5 to 60 min, preferably 10 to 30 min.
Range. In the processing outside the above range, the object of the present invention is not achieved.

The coating composition of the present invention is used for improving the film forming property of an organic resin film formed on a metal surface, for example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol. Monopropyl ether, trimethylpentanedyl isobutyrate,
A solvent such as 2-ethylhexyldiglycol may be contained in an amount of 10 wt% or less based on the solid content of the organic resin. If it exceeds 10% by weight, the stability of the coating composition is undesirably reduced. Further, for the purpose of maintaining the coating composition more stably, the above-mentioned anionic surfactant or nonionic surfactant may be further contained as necessary. If necessary, pigments such as carbon black, phthalocyanine blue, phthalocyanine green and barium sulfate may be contained.

The aqueous self-precipitating coating composition used in the present invention consists essentially of an anionic polyester resin as an organic resin, but may be water-dispersible or water-soluble as long as the object of the present invention is not impaired. An acrylic resin, a urethane resin, an epoxy resin, a melamine resin, a phenol resin, or the like may be contained.

By coating the metal surface, particularly the iron-based metal surface, with the aqueous self-precipitating coating composition of the present invention, the iron-based metal surface can be treated without post-treatment (chemical treatment before drying). Further, excellent corrosion resistance, adhesion and heat resistance can be imparted. The effects that can be achieved by using the aqueous self-precipitating coating composition of the present invention are considered as follows. The coating film formed by using a polyester resin as the organic resin component in the self-deposition type coating composition has a good barrier property against oxygen and water vapor due to the property that the polyester resin itself has relatively crystallinity, and has a corrosion resistance. , Adhesion is provided. Further, by introducing an aromatic ring into the resin skeleton using an aromatic carboxylic acid derivative or the like, corrosion resistance,
Adhesion and heat resistance can be imparted. The aromatic ring in the resin skeleton is a portion having a high electron density, and this reacts with a portion having a high electron density on the metal surface to improve the adhesion to the material. Further, by introducing a functional group (—COOH group) into the resin skeleton by using a carboxylic acid derivative having three or more functions, the adhesion to the material is improved.

[0041]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples. Note that the present invention is not limited by these examples. A method for testing the film performance of the test plates prepared in the examples and comparative examples will be described.

(1) Film Thickness The film thickness was measured at the upper, middle, and lower portions of the test plate, and the average value was shown. (2) Corrosion resistance A test plate in which a cross-cut reaching the metal substrate was provided on the coating film was subjected to a salt spray test (JISZ-2371) for 500 hours. After the test, the tape was peeled off, and evaluated by the peeling width (maximum on both sides: mm) from the cross cut portion.

(3) Adhesion (cross-cut tape peeling test) 1 square 100 mm square was cut into a test plate before and after immersion in warm water at 40 ° C. × 240 hours, the tape was peeled off, and the number of stitches remaining on the film was measured. The following was evaluated. A before the immersion and b after the immersion. ○: No peeling ○ ': Less than 10 peels △: Less than 50 peels ×: 50 or more peels

(4) Heat Resistance The test plate was subjected to continuous heating at 150 ° C. for 24 hours, and then subjected to the same test as in the above (3) to evaluate the test. The composition of the polyester resin used in the present invention is shown in Table 1. In addition, each of the resins (A to I) in Table 1 was adjusted to a resin solid content of 25% (the solvent was water).

Examples 1 to 9 Using the aqueous coating compositions prepared using the polyester resins A to I (all having a resin solid content of 25%) having the compositions shown in Table 1 and having the formulations shown in Table 2 Then, the bath temperature of the coating composition was maintained at 20 to 22 ° C., and a cold-rolled steel plate (70 × 150 × 0.8 mm size) which had been cleaned in advance was applied by dipping for 180 seconds, followed by washing by dipping. Then, after drying in a hot air oven at 180 ° C. for 20 minutes, each film was subjected to a film performance test.

COMPARATIVE EXAMPLE 1 Using an aqueous coating composition prepared according to the following formulation, the bath temperature of the coating composition was maintained at 20 to 22 ° C., and a cold-rolled steel sheet (70 × 150 × 0.8 mm size) for 180 seconds to paint, then rinsed with water and dried in a hot air oven at 180 ° C for 20 minutes,
Each film was subjected to a performance test. [Aqueous coating composition] Component blending amount [g / L] Rhoplex WL-91 130.00 (resin solid content; 41.5%) ¹⁾ Hydrofluoric acid 1.00 Ferric fluoride 3.00 Hydrogen peroxide 0.10 Deionized water (total volume 1L) 1) Acrylic resin (Rohm & Hass)

Comparative Example 2 Using an aqueous coating composition prepared according to the following formulation, the bath temperature of the coating composition was maintained at 20 to 22 ° C., and a cold-rolled steel sheet (70 × 150 × (0.8 mm size) for 150 seconds for painting, then immersion and water washing, and then immersing the uncured organic resin film in ammonium bicarbonate-containing aqueous solution of pH 8.0 for 1 minute, followed by hot air oven After drying at 110 ° C. for 20 minutes, each film was subjected to a film performance test.

[Aqueous coating composition] Component amount [g / L] Daran SL14 3 109.00 (resin solid content; 55%) ²⁾ Hydrofluoric acid 1.00 Ferric fluoride 3.00 Hydrogen oxide 0.10 Deionized water (total volume 1L) 2) Vinylidene chloride resin (manufactured by WRGrace) Table 3 shows the test evaluation results of the examples and comparative examples.

As can be seen from Table 3, Examples 1 to 9 using the aqueous self-deposition coating composition of the present invention were excellent in corrosion resistance, adhesion and heat resistance without performing a chemical treatment (post-treatment). You can see that it is. Comparative Example 1 using an acrylic resin is inferior in corrosion resistance. Comparative Example 2 using a vinylidene chloride resin had poor heat resistance.

[0050]

The metal surface is coated with the aqueous self-precipitating coating composition of the present invention so that the metal surface can be subjected to corrosion resistance, adhesion and heat resistance without being subjected to a chemical treatment (post-treatment). An excellent organic resin film can be formed, and it can be said that the present invention is extremely useful in practical use.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryosuke Sako 1-15-1, Nihonbashi, Chuo-ku, Tokyo Japan F-term in Parkerizing Co., Ltd. (Reference) 4D075 BB24Z CA13 CA18 CA33 DA06 DB02 DB05 DB07 EA06 EB35 4J038 DD061 DD071 DD081 DD091 DD101 DD121 HA096 HA156 HA246 HA256 HA336 HA416 KA02 MA08 MA09 MA10 MA12 NA03 NA12 NA14 PA15 PA19 PC02

Claims (5)

[Claims] 1. An aqueous self-precipitating coating composition containing a water-dispersible or water-soluble organic resin, an acid, an oxidizing agent and / or a metal ion, wherein the organic resin comprises a polyhydric alcohol component ( A self-precipitating coating composition, which is an anionic polyester resin comprising a condensate of a) and an acid component (b). 2. The polyhydric alcohol component (a) comprises:
At least one selected from the group consisting of (a) -1 and (a) -2, wherein the acid component (b) is (b)-
1, (b) -2, (b) -3, (b) -4 and
The coating composition according to claim 1, which is at least one member selected from the group consisting of (b) -5. Embedded image (A) -1 is an aliphatic polyhydric alcohol derivative represented by the general formula (1), and in the general formula (1), R ₁ is
It is a linear or branched alkylene having 1 to 10 carbon atoms, or alkylene containing a hydroxyl group and / or a halogen element in a part of the alkylene. Embedded image (A) -2 is an aromatic polyhydric alcohol derivative represented by the general formula (2). In the general formula (2), m and n are integers of 1 or more and 2 ≦ m + n ≦ 6. . R ₂ , R
₃ , R ₄ and R ₅ are each independently at least one selected from hydrogen and —CH ₃ . Embedded image (B) -1 is an aliphatic carboxylic acid derivative represented by the general formula (3). In the general formula (3), X ₁ and X ₂ are each independently hydrogen, a carbon atom having 1 to 10 carbon atoms. It is at least one selected from alkyl groups. R ₆ has 1 to 3 carbon atoms
0 linear or branched alkylene or in the alkylene,, -COOX ₃ (where _{X 3} is hydrogen, an alkyl group having 1 to 10 carbon atoms) in a part of an alkylene containing. Embedded image (B) -2 is an aromatic carboxylic acid derivative represented by the general formula (4), and in the general formula (4), (X ₄ , X ₅
Are independently at least one selected from hydrogen and an alkyl group having 1 to 3 carbon atoms. Y ₁ , Y ₂ , Y ₃
And Y ₄ are each independently hydrogen, —COOX ₆ (where X ₆ is hydrogen, an alkyl group having 1 to 3 carbon atoms, Na,
_{K, Ca, Ba, Li,} NH 4), - SO 3 Z 1 ( wherein _{Z 1} is hydrogen, Na, K, Ca, Ba , Li, NH 4)
At least one member selected from the group consisting of: Embedded image (B) -3 is an aromatic acid anhydride derivative represented by the general formula (5). In the general formula (5), Y ₅ and Y ₆ are each independently hydrogen, —COOX ₇ (here, And X ₇ is hydrogen, an alkyl group having 1 to 3 carbon atoms, Na, K, Ca, B
a, Li, NH ₄ ) and —SO ₃ Z ₂ (where Z ₂ is hydrogen, Na, K, Ca, Ba, Li, NH ₄ ). Embedded image (B) -4 is an anhydride of pyromellitic acid represented by the general formula (6). Embedded image (B) -5 is a naphthalene derivative represented by the general formula (7). In the general formula (7), Y ₇ , Y ₈ , Y ₉ ,
And Y ₁₀ are, independently of one another, hydrogen, -COOX
₈ (where X ₈ is hydrogen or an alkyl group having 1 to 3 carbon atoms). 3. The method according to claim 2, wherein the acid component (b) is (b) -2 and
(B) at least one member selected from the group consisting of -3
(B) -2 and (b) -3
Is Y in general formulas (4) and (5).₁~ Y₆Little
At least one is -COOX_{6 '}(Where X_{6 '}Is water
Element, Na, K, Ca, Ba, Li, NH ₄), -SO₃
Z₁(Where Z₁Is hydrogen, Na, K, Ca, Ba, L
i, NH₄) And -COOX_{7 '}(Where X_{7 '}Is water
Element, Na, K, Ca, Ba, Li, NH₄), -SO₃
Z₂(Where Z₂Is hydrogen, Na, K, Ca, Ba, L
i, NH₄3. The coating composition according to claim 2, wherein 4. A method comprising bringing the coating composition according to claim 1 into contact with a metal surface to form an uncured organic resin film on the metal surface, washing with water, and then heating and drying. A method for coating a metal surface. 5. A coated metal material treated by the coating method according to claim 4.