JPH04314766A - Water-based rust-inhibiting coating composition - Google Patents

Abstract

PURPOSE:To provide a water-based rust-inhibiting coating composition having a vary excellent rust-inhibiting power when applied to various metallic products. CONSTITUTION:This composition comprises a latex of a vinylidene chloride polymer or a copolymer of vinylidene chloride with a vinyl monomer copolymerizable therewith, an epoxy resin soluble or dispersible in water and a complexing agent which is a compound having a functional group which can form a complex compound when combined with a metallic ion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous rust-preventing paint composition for forming a coating film for the purpose of rust-preventing various metal products including iron, zinc, aluminum, and magnesium.

0002

[Prior Art] Conventionally, for the purpose of rust prevention of various metal materials such as iron (including plated steel sheets), methods of spraying or dipping coating with alkyd resin-based or melamine-alkyd resin-based water-based paints, or anion coating methods have conventionally been used. Alternatively, a method of electrodepositing a cationic electrodeposition paint is used.

However, in the case of alkyd resin-based or melamine-alkyd resin-based paints, they often cannot satisfy the recent demands for high rust prevention performance, and the drawback is that the rust prevention ability is insufficient, especially in thin areas. have.

[0004] In addition, although electrodeposition paints have superior anti-rust properties compared to these, they require a lot of energy in the baking process, and they also damage the edges of the base material and the convex parts of uneven surfaces. It has the disadvantage that the film thickness becomes thinner due to flow during baking, resulting in poor rust prevention ability.

[0005] In contrast, coating films made of vinylidene chloride copolymers have recently been reported to have excellent density and the ability to block moisture and oxygen from permeating through the coating (hereinafter referred to as barrier properties). Taking advantage of these characteristics, water-based anticorrosion paints using vinylidene chloride copolymer latex containing a complexing agent have been proposed (Japanese Patent Application Laid-open No. 105073/1982 and 198669/1999).

[0006]

[Problems to be Solved by the Invention] However, when a coating composition using such a vinylidene chloride copolymer latex is subjected to a salt spray test, although the rust prevention at the cross cut portion is sufficient, the rust prevention at other portions is insufficient. It has drawbacks such as blistering and poor adhesion, and these drawbacks are particularly noticeable when applied to galvanized steel sheets.

[0007] Accordingly, the object of the present invention is to provide a water-based rust-preventing paint composition that has extremely excellent rust-preventing power when applied to various metal product substrates such as iron, zinc, aluminum, magnesium, and galvanized steel. It is in.

[0008]

[Means for Solving the Problems] The present invention provides a latex (A) of a vinylidene chloride polymer or a copolymer of vinylidene chloride and a vinyl group-containing monomer copolymerizable therewith, and a latex (A) that can be dissolved or dispersed in water. This is an aqueous anticorrosive paint composition containing an epoxy resin (B) and a complexing agent (C), which is a compound having a functional group capable of forming a complex with a metal ion.

The present inventors have applied the latex (A), epoxy resin (B), and complexing agent (C) together in a certain ratio as described below to coat various metal product substrates as described above. The present invention has been completed by obtaining a water-based rust-preventing paint composition that exhibits extremely excellent rust-preventing properties.

The latex (A) used in the present invention contains vinylidene chloride monomer or a mixture of vinylidene chloride monomer and a vinyl group-containing monomer copolymerizable therewith.
It can be obtained by a known method, for example, by emulsion polymerization using a polymerization initiator in the presence of an emulsifier.

[0011] As the emulsifier and polymerization initiator used here, conventionally used emulsifiers can be used. However, in view of the performance of the coating film obtained using the aqueous anticorrosive paint composition of the present invention, nonionic emulsifiers are preferable as emulsifiers. are preferred, and particularly preferred are reactive nonionic emulsifiers having a vinyl group copolymerizable with vinylidene chloride in their molecules.

[0012] The latex (A) generally has a nonvolatile content, that is, a resin solid content of 40 to 6 parts by weight in 100 parts by weight of the latex.
The remaining 60 to 40 parts by weight can be composed of water or a mixture of water and a small amount of a water-soluble organic solvent such as alcohols, cellosolves, carbitols, ethers, etc.

[0013] The vinylidene chloride polymer or copolymer in the latex (A) preferably has a particle size of 50 nm to 200 nm for reasons such as stability of the coating composition formed and good coating workability.

When a vinylidene chloride copolymer is used in the latex (A), vinyl group-containing monomers copolymerizable with vinylidene chloride include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)ethyl acrylate. (Meth) such as propyl acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, etc.
One type or a mixture of two or more types of esters of acrylic acid, (meth)acrylic acid, and vinyl compounds such as vinyl chloride, vinyl acetate, styrene, acrylonitrile, vinyltoluene, vinyl fluoride, and vinylidene fluoride can be used. .

In the latex (A) of the present invention, a polymer of only vinylidene chloride can be used, but a copolymer of vinylidene chloride and the above-mentioned vinyl group-containing monomer copolymerizable with vinylidene chloride is used. In this case, the content of vinylidene chloride in this copolymer is preferably 30% by weight or more, particularly preferably 50% by weight or more.

[0016] When the content of vinylidene chloride in the vinylidene chloride copolymer is less than 30% by weight, the crystallinity of the vinylidene chloride copolymer becomes low and the barrier properties of the formed coating film become poor. Undesirable.

Conventionally, when a latex containing a vinylidene chloride polymer or a vinylidene chloride copolymer containing about 95% by weight or more of vinylidene chloride is used, crystals of the vinylidene chloride polymer or copolymer occur in the formed coating film. It had the disadvantage that the strength was too high and the adhesion to the object to be coated was poor.

However, in the coating composition according to the present invention, vinylidene chloride can be reduced to 95% by containing an epoxy resin as component (B) and a complexing agent as component (C), which will be described later.
It has been found that not only copolymers containing more than % by weight, but also polymers containing only vinylidene chloride can be used.

The epoxy resin (B) which can be dissolved or dispersed in water used in the coating composition of the present invention is diglycidyl ether of polyalkylene oxide, diglycidyl ether of polyalkylene oxide adduct to polyphenol, or polyphenol. Reaction products of polyglycidyl ethers of phenols and secondary amines can be used.

Examples of the diglycidyl ether of polyalkylene oxide that can be used include diglycidyl ether of polyethylene oxide and diglycidyl ether of polypropylene oxide.

The diglycidyl ether of polyalkylene oxide adducts to polyphenols includes, for example, 2,2
- diglycidyl ether of polyethylene oxide adduct to bis(4-hydroxyphenyl)-propane, 2
, 2-bis(4-hydroxyphenyl)-diglydisyl ether of polypropylene oxide adduct to propane, 2,2-bis(4-hydroxycyclohexane)-
Examples include diglycidyl ether of polypropylene oxide adducts to propane.

Epoxy resins having these polyalkylene oxides in their skeletons have strong hydrophilicity and can be dispersed in water by themselves, but the water resistance and rust prevention of the coating films formed with the coating compositions of the present invention are From the viewpoint of properties, it is preferable that the molecular weight is large, and those having a molecular weight of usually 800 to 5,000 are particularly preferable.

The polyglycidyl ether of the polyphenol is generally produced, for example, by etherifying epichlorohydrin or dichlorohydrin with the polyphenol in the presence of an alkali. Examples of polyphenols include 2,2-bis(4-hydroxyphenyl)-propane, 4,4'-dihydroxybenzophenone, 1,1
-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-isobutane, 2,2-
Examples include bis(4-hydroxy-t-butylphenyl)-propane and bis(2-hydroxynaphthyl)methane. Since such epoxy resins do not have hydrophilic properties by themselves, they must be reacted with amines to impart hydrophilic properties. As usable amines, any of primary amines, secondary amines, and tertiary amines can be used, but secondary amines are particularly preferred, and these reaction products can be neutralized with an inorganic or organic acid to make them hydrophilic. It's good to do that.

The secondary amines include aliphatic or cycloaliphatic amines such as diethylamine, dipropylamine, dibutylamine, ethylpropylamine, and alkanolamines such as methylethanolamine, ethylethanolamine, methylisopropanolamine, diethanolamine. , diisopropanolamine, and cyclic amines such as pyrrolidine, piperidine, morpholin, which can also be used in mixtures of two or more.

[0025] The polyglycidyl ether of polyphenol and the secondary amine have an equivalent ratio of glycidyl group to amine of 1/1.
or more, i.e., in the absence of a solvent or in the presence of a suitable solvent such as alcohol, cellosolve, ketone, toluene, xylene, etc., in a proportion where the glycidyl group is equivalent or more.
The reaction is carried out at a temperature of 0 to 120°C to obtain an amine-modified epoxy resin. This amine-modified epoxy resin preferably contains 0.3 to 2 moles of amino groups per 1 kg of solid content.

As the acid for neutralizing the resin which is a reaction product of polyglycidyl ether of polyphenol and secondary amine, organic acids such as formic acid, acetic acid, propionic acid, and lactic acid, or hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid are used. Inorganic acids such as acids can be used, and the resin is dispersed in water after being neutralized with these acids.

The complexing agent (C), which is a compound having a functional group capable of forming a complex with a metal ion, used in the coating composition of the present invention includes, for example, mercaptopropionic acid and neopentyl glycol, trimethylolpropane or Examples include thiol group-containing compounds such as esters with alcohols such as pentaerythritol, phenolic hydroxyl group-containing compounds such as tannic acid, gallic acid, pyrogallol, and catechol, and phosphoric acid group-containing compounds such as phosphoric acid or phytic acid. It can be used alone or in the form of a mixture of two or more.

The above-mentioned complexing agent (C) may be used as it is or dissolved in a water-soluble solvent such as alcohol and pre-dispersed in the latex (A) of the coating composition of the present invention, or The above-mentioned epoxy resin that can be dispersed in water (
Part or all of B) may be reacted and used in a state bonded to an epoxy resin skeleton. The latter method is preferable because it provides excellent adhesion between the coated object and the coating after the coating is formed. At this time, a functional group that can react with the epoxy group in the epoxy resin and the epoxy group in the complexing agent, such as a thiol group,
A desired compound is obtained by reacting with a phenolic hydroxyl group, a phosphoric acid group, a carboxyl group (for example, contained in gallic acid), and the like.

[0029] This reaction method is based on the epoxy resin (B)
The epoxy group of the complexing agent (C) is reacted with a functional group that can react with the epoxy group of the complexing agent (C), such as a thiol group, a phenolic hydroxyl group, a carboxyl group, a phosphoric acid group, etc., and maintains the ability to form a complex compound. In order to prevent gelation during the reaction, the number of each of the above-mentioned functional groups is preferably carried out in excess of the number of epoxy groups. The reaction temperature is usually 40 to 120 DEG C., and the reaction is carried out without a solvent or, if necessary, in an organic solvent such as alcohols, esters, ethers, ketones, etc. Furthermore, when modifying with the amine, it is preferable to add these complexing agents at the same time to react, since gelation during the reaction can be prevented.

[0030] The aqueous anticorrosion coating composition according to the present invention comprises the above-mentioned vinylidene chloride polymer or vinylidene chloride copolymer latex (A), the above-mentioned epoxy resin (B) and the above-mentioned complexing agent (C) in water. Mix thoroughly to form a stable emulsion.

[0031] At this time, if necessary, coloring pigments, anti-rust pigments, extender pigments, curing agents such as melamine or blocked isocyanate compounds, and other various additives commonly used in paints such as plasticizers, surfactants, and humectants are added. and organic solvents may also be added.

In the aqueous rust-preventing paint composition according to the present invention, the solid content of component (A) is 30 to 65 parts by weight in terms of the vinylidene chloride content contained therein, and the solid content of component (B) is 1.
30 parts by weight, and the solid content of component (C) is 5 to 40 parts by weight.

[0033] If the vinylidene chloride content contained in the solid content of the component (A) is less than 30 parts by weight, the coating film derived from vinylidene chloride will not have sufficient barrier properties, resulting in poor rust prevention ability. This is not desirable because it becomes like this. Also 65
If the amount exceeds 1 part by weight, the coating film formed will become too hard, vinylidene chloride will decompose when heat is applied, a large amount of hydrochloric acid will be released, and the heat resistance of the coating film will deteriorate, which is not preferable.

The solid content of component (B) is 1 to 30 parts by weight, preferably 5 to 25 parts by weight, based on the solid content of the epoxy resin excluding the amine and complexing agent when reacted. If the amount is less than 1 part by weight, the adhesion of the formed coating film to the metal substrate of the object to be coated becomes poor, which is not preferable. Moreover, if it exceeds 30 parts by weight, it is not preferable because it lowers the crystallinity of the vinylidene chloride polymer or copolymer as the component (A), thereby degrading the barrier properties of the coating film and degrading the antirust ability.

[0035] In addition, the solid content of the complexing agent of the component (C) is 5 to 5, including the complexing agent, when part or all of it is bonded to the epoxy resin as described above. 4
0 parts by weight, preferably 10 to 30 parts by weight. If the amount is less than 5 parts by weight, the amount of complex compound with the metal of the object to be coated will be insufficient, and the adhesiveness and antirust ability of the coating film formed will be poor, which is not preferable. Moreover, if it exceeds 40 parts by weight, it becomes difficult to obtain a uniform coating film, and when a rust prevention test is performed,
Blisters and spots of rust may occur on the paint film, which is undesirable.

[0036] Brush coating, spray coating, dipping coating, and electrodeposition coating can be used for coating the aqueous rust-preventing paint composition according to the present invention.
About 5 to about 40 minutes, preferably 10 to about 40 minutes at a temperature of ~100°C
Dry for 30 minutes to obtain a cured film.

[0037] When painting, the viscosity may be adjusted by diluting with water or adding a thickener in order to make the paint viscosity suitable for each coating method.

[0038] In case of dip coating, the temperature is between room temperature and about 60℃.
The object to be coated is immersed in the paint solution at a temperature of 5 seconds to 3 minutes, preferably 10 seconds to 60 seconds, and after the coating film has adhered, the temperature is between room temperature and about 40 degrees Celsius.
for 1 to 40 minutes, preferably 2 to 10 minutes, and then dried as described above.

When performing electrodeposition coating, an electrical conductor (preferably a stainless steel plate, a platinum plate, or a carbon rod can be used) is immersed opposite the object to be coated, and a DC voltage is applied using these as electrodes. By doing so, electrodeposition coating can be performed. If the object to be coated is used as a cathode at this time, the vicinity of the surface of the object becomes a reducing environment, the stabilization of emulsion particles is destroyed, aggregation and precipitation occur, and a coating film is formed. Conversely, when the object to be coated is used as an anode, the metal of the object to be coated dissolves into the paint, so a complexation reaction progresses on the surface of the object, bonding of paint particles occurs, and a precipitated coating film is also formed. be done.

[0040] The voltage applied during electrodeposition coating is usually 1 to 500V.
, preferably 10 to 300V, and the time is usually 1 second to 5 minutes, preferably 20 seconds to 3 minutes.

[0041]

[Operation] When the aqueous rust-preventive coating composition of the present invention is applied to various metal objects as described above, the coating film becomes dense due to the crystallinity of the vinylidene chloride polymer or vinylidene chloride copolymer. In addition to obtaining high barrier properties, good adhesion to the substrate to be coated is obtained due to the hydroxyl groups and other polar groups contained in the epoxy resin. Furthermore, since the coating composition according to the present invention contains a complexing agent, a complex bond is generated between the coating film and the metal to be coated, and at the same time, extremely strong adhesion is applied, and at the same time, resin molecules are bonded via metal molecules. Since the comrades combine to form a polymerized or three-dimensional crosslinked structure, a denser and tougher coating film can be obtained. It also complexes rust components (metal ions) generated in a corrosive environment to form a stable compound and suppress the growth of rust.

[0042]

[Examples] The present invention will be explained below with reference to Examples.
The present invention is not limited to these. All figures in the middle part of the sentence and percentages are weights.

Production Example 1 (vinylidene chloride copolymer latex A-
1) Raw materials
Department
Solid content (parts) ────────────────
────────────── ■Deionized water
96.3
■Aqualon RN-20 1.0
1.0 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., vinyl group-containing polyoxyethylene alkyl phenol ether) ■Potassium persulfate
0.2 0.2 ■Vinylidene chloride 80
80 ■Butyl acrylate
16 16
■Glycidyl methacrylate
4 4 ■Potassium persulfate 0.05
0.05 ■Deionized water
4.95 ────────
──────────────────────
total
202.5 101.25

[0044]
The above raw materials ■, ■, ■ were placed in a glass-lined autoclave equipped with a stirrer, and the temperature was raised to 45°C, and the inside of the container was flushed with N2.
After sufficient replacement with gas, the mixture of ■, ■, ■ was heated to 18
It was added continuously at a constant rate over time. Then 45℃
The mixture was stirred for 1 hour, and then a mixture of ① and ② was added at a constant rate over 1 hour. The solid content was further stirred at 45°C for 3 hours until the solid content was 50% (
Latex A-1 (vinylidene chloride content 79.0%)
I got it.

Production Example 2 (Production of Vinylidene Chloride Copolymer Latex A-2) The same procedure was followed as in Production Example 1 except that only the polymerizable monomer was changed as shown below. .3%) latex A-2 was obtained. material
Part Solid content (part)
────────────────────────
── Vinylidene chloride
60 60 Butyl acrylate 35
35 Methacrylic acid
5 5

Production Example 3 (Production of acrylic emulsion solution A-3 that does not contain vinylidene chloride) Raw materials
Part Solid content (part) ────────────────────
───────── ■Deionized water
98.3 ■Aqualon RN-20 2.0
2.0 ■Potassium persulfate
0.2 0.2
■Methyl methacrylate 80
80 ■Butyl acrylate 16
16 ■ Glycidyl methacrylate
4 4 ■Potassium persulfate 0.05
0.05 ■Deionized water
4.95 ────
──────────────────────────
total
205.5 102.25

00
47] Put ■, ■, and ■ into a 1L four-necked flask equipped with a stirrer, cooling tube, and thermometer, and while flowing N2 gas,
The temperature was kept at 60°C. Next, a mixture of (1), (2), and (2) was added dropwise at a constant rate over 1 hour, followed by stirring at 60°C for 1 hour. Next, a mixture of (1) and (2) was added, and stirring was continued for 1 hour at 60°C to obtain an acrylic emulsion solution A-3 with a solid content of 50% (vinylidene chloride 0%).

Production Example 4 (Aqueous dispersion of amine-modified epoxy resin B-
1) Raw materials
Part Solid content (part)
Solid content ratio ────────────────
──────────────── ■ESA-
011P 950 95
0 81.9 (Sumitomo Chemical Co., Ltd.)
Bisphenol A type epoxy resin, epoxy equivalent: 475) ■Methoxypropanol 497
■Diethanolamine 210
210 18.1 ───
──────────────────────────
─── Total
1657 1160 1
00

[0049] Put ■ and ■ into a 2 liter four-necked flask equipped with a stirrer, a cooling tube, and a thermometer, heat it to 100°C to dissolve ■, then add ■, and react at 120°C for 2 hours. Epoxy resin solid content ratio 81.9%, solid content 70%
An amine-modified epoxy resin liquid C-1 was obtained.

[0050] Raw materials
Part Solid content (part) ──────────────────
─────────── ■The above amine-modified epoxy 1500 1050
Resin liquid C-1 ■Acetic acid
37.8 ■Deionized water
1087.2 ────
──────────────────────────
total
2625 1050

0
Next, (1) and (2) were placed in a 5 liter stainless steel cylindrical container, and (2) was gradually added while stirring with a disper to obtain a stable emulsion solution B-1 with a solid content of 40%.

Production Example 5 (Production of aqueous dispersion B-2 of thiol group-containing amine-modified epoxy resin) Raw materials
Department
Solid content (parts) Solid content ratio ────────
────────────────────────
■ESA-011P 950
950 61.5 ■Methoxypropanol 662 ■Pentaerythritol 489 489
31.7 Tetra(mercaptopropionic acid) ester ■Diethanolamine 105
105 6.8 ─
──────────────────────────
───── Total
2206 1544
100

3L with stirrer, cooling tube, and thermometer
■ and ■ were placed in a four-necked flask, heated to 100°C to dissolve ■, and then cooled to 50°C. Furthermore, ■ and ■ were added, and after holding at 65℃ for 2 hours, the temperature was raised to 120℃, and 2
This was maintained for a period of time to obtain a thiol group-containing amine-modified epoxy resin liquid C-2 having a solid content of 61.5% for the epoxy resin, a solid content for the complexing agent of 31.7%, and a solid content of 70%.

[0054] Raw materials
Part Solid content (part) ──────────────────
─────────── ■The above epoxy resin liquid 1000 7
00 C-2 ■Acetic acid
25.2 ■Deionized water
724.8 ──────
────────────────────────
total
1750 700

0
Next, (1) and (2) were placed in a 3 liter stainless steel cylindrical container, and (2) was gradually added while stirring with a disper to obtain emulsion solution B-2 with a solid content of 40%.

Production Example 6 (Production of aqueous dispersion B-3 of phenolic hydroxyl group-containing amine-modified epoxy resin) Raw materials
Part Solid content (Part) Solid content ratio ────────────────────
──────────── ■ESA-011P
950 950
77.5 ■Methoxypropanol
519.4 ■Gallic acid
170 170
13.9 ■Tributylamine
5.6 ■Diethanolamine
105 105 8
．． 6 ────────────────────
──────────── Small
Total 1750 12
25 100

[0057] Stirrer, cooling pipe,
Pour ■ and ■ into a 3L 4-mouthed kolben with a thermometer, 10
The mixture was heated to 0°C to dissolve (1), (2) and (2) were added, the temperature was raised to reflux temperature, and the mixture was reacted for 5 hours. After further cooling to 100°C, (2) was added and reacted at 100°C for 2 hours to form a phenolic hydroxyl group-containing amine-modified epoxy with a solid content of 77.5% for the epoxy resin, 13.9% for the complexing agent, and a solid content of 70%. Resin liquid C-3 was obtained.

[0058] Raw materials
Part Solid content (part) ──────────────────
─────────── ■The above epoxy resin liquid 1000 7
00 C-3 ■Acetic acid
25.2 ■Deionized water
724.8 ──────
────────────────────────
total
1750 700

0
Next, (1) and (2) were placed in a 3 liter stainless steel cylindrical container, and (2) was gradually added while stirring with a disper to obtain emulsion solution B-3 with a solid content of 40%.

Examples 1 to 9, Comparative Examples 1 to 3 Table 1
An aqueous dispersion of vinylidene chloride copolymer latex, epoxy resin, or modified epoxy resin shown in Production Example 2 above, and a compound having a functional group capable of forming a complex compound with a metal ion at the blending ratio shown in After charging the mixture into a cylindrical container and thoroughly stirring to obtain a stable emulsion solution, carbon black was added at a ratio of 0.5 parts to 100 parts of the emulsion solution, and the pigment was dispersed in a bead mill to form a paint.

[0061] Cold-rolled steel sheets and alloyed hot-dip galvanized steel sheets were immersed in the paint thus obtained for 30 seconds, left to stand at room temperature for 10 minutes, and then dried for 20 minutes in a drying oven maintained at 60°C. I let it happen.

The thus obtained coated plates were subjected to various tests, and the results obtained are shown in Table 1.

Example 10 After adding water to the paint prepared in the same manner as in the above example to make the solid content 20%, a stainless steel plate of the same size as the opposite electrode of the object to be coated was immersed. As a cathode, 1
After electrodeposition coating was performed by applying a direct current of 00V for 2 minutes, drying was performed in the same manner as in the other examples.

The coated plates thus obtained were subjected to various tests, and the results are shown in Table 1.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

[Table 4]

[0069]

[Table 5]

(Note 1) Contained in modified epoxy resin liquid B-2. (Note 2) Contained in modified epoxy resin liquid B-3. (Note 3) Parts by weight of solid content of each component based on 100 parts by weight of the above solid content. (Note 4) (A): Cold rolled steel plate width 70mm, length 1
50mm, thickness 0.8mm, (b): 45g/m2 of alloyed hot-dip galvanizing on (a)
Both (a) and (b) are manufactured by Nippon Test Panel Co., Ltd. (Note 5) Number of tape-removed pieces out of 100 1 mm squares. (Note 6) JIS K-5400-9-1 Maximum width of rust and blisters from the cross cut section [mm].

[0071]

[Effects of the Invention] By using the aqueous rust-preventing paint composition of the present invention, it is possible to form a coating film having excellent adhesion and rust-preventing ability to various metals including iron. The painting method is
Any of brush coating, spray coating, dip coating, and electrodeposition coating can be used, and drying can be performed at a relatively low temperature of room temperature to 120°C.

Claims (6)

[Claims] 1. A latex (A) of a vinylidene chloride polymer or a copolymer of vinylidene chloride and a vinyl group-containing monomer copolymerizable therewith, and an epoxy resin (B) that can be dissolved or dispersed in water, and Complexing agent (C) which is a compound having a functional group capable of forming a complex compound with a metal ion
An aqueous anticorrosive paint composition characterized by containing. Claim 2: The solid content of (A) is 30 to 65 parts by weight in vinylidene chloride content, the solid content of (B) is 1 to 30 parts by weight, and the solid content of (C) is 5 to 40 parts by weight. The aqueous antirust coating composition according to claim 1, characterized in that: 3. Claim 1, wherein the epoxy resin (B) that can be dissolved or decomposed in water is diglycidyl ether of polyalkylene oxide or diglycidyl ether of polyalkylene oxide adduct to polyphenol. water-based anticorrosive paint composition. 4. The epoxy resin (B) which can be dissolved or dispersed in water is a reaction product of a polyglycidyl ether of a polyphenol and a secondary amine, which is neutralized with an organic acid or an inorganic acid. The aqueous antirust coating composition according to claim 1. 5. The aqueous anticorrosive coating composition according to claim 1, wherein a compound whose functional group capable of forming a complex with a metal ion is a phenolic hydroxyl group, a thiol group, or a phosphoric acid group is used. 6. A claim characterized in that the complexing agent (C) is one obtained by reacting the epoxy resin according to claim 3 or 4 with a part or all of the compound having a functional group according to claim 5. A water-based anticorrosive paint composition of No. 1.