JP2002121491A - Cationic electrodeposition coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cationic electrodeposition coating composition capable of forming coating film with high throwing power and good smoothness. SOLUTION: This cationic electrodeposition coating composition is obtained by compounding a water-dispersed paste prepared by mixing/dispersing a formulation comprising a layered carbonaceous compound <=5 μm in the maximum particle size, a magnesium silicate-based extender pigment, a dispersing resin and deionized water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cationic electrodeposition coating composition having excellent throwing power and forming a coating film having good smoothness.

[0002]

2. Description of the Related Art Cationic electrodeposition paints have excellent workability in coating and have good corrosion resistance of the coating film. Widely used. Such an electrodeposition paint is generally produced by mixing and dispersing a cationic resin, an anticorrosion pigment, an extender pigment, and the like in water.
In recent years, the degree of performance required for cationic electrodeposition coatings has increased, and for example, there has been a strong demand for further improvements in, for example, coatability, throwing power, and smoothness of coatings in bag-like interiors and narrow portions.

[0003]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to respond to these demands. As a result, the cationic electrodeposition coating composition contains a layered carbon compound having a maximum particle size of 5 μm or less. The present inventors have found that the objectives described above can be achieved, and have completed the present invention.

That is, according to the present invention, the maximum particle size is 5
Cationic electrodeposition coating composition characterized by containing a layered carbon compound of μm or less (hereinafter referred to as “the present composition”)
Is provided.

The layered carbon compound to be contained in the present composition is a carbon compound having a crystal structure in which atoms or atomic groups are arranged in a plane to form a sheet structure, and a sheet-like repetition is observed in a direction perpendicular to the plane. Yes, specifically, graphite, that is, graphite, and the like. Examples thereof include hexagonal graphite, rhombohedral graphite, and the like, which form a layer by stacking sheets having a hexagonal network structure.

Conventionally, these layered carbon compounds have been blended in paints for the purpose of imparting conductivity to the coating film, and have a maximum particle size of at least 10 μm and a blending amount of 100 parts by weight of resin solids. In most cases, the amount is 10 parts by weight or more.

A feature of the present composition is that the layered carbon compound is formed into a fine powder having a maximum particle size of 5 μm or less, preferably 0.5 to 2 μm, and is contained in a cationic electrodeposition coating composition. As a result, it is possible to significantly improve the smoothness of the electrodeposited coating film, particularly in the flat portion, and also to improve the throwing power of the electrodeposition coating, and to improve the inside of the bag-shaped object and the narrow portion of the object to be coated. The coating film forming property was excellent, and it became possible to improve the anticorrosion property and the like in these portions.

[0008] In the present composition, as the cationic electrodeposition paint containing such a layered carbon compound, those known per se can be used, for example, a base resin having a hydroxyl group and a cationic group, a curing agent, a coloring pigment, a rust preventive. An aqueous paint obtained by mixing and dispersing a pigment, an extender, a neutralizing agent, an organic solvent and the like in water such as deionized water can be used.

The base resin is a resin having a hydroxyl group and a cationic group. The hydroxyl group is involved in a crosslinking reaction with a curing agent, and the cationic group is for forming a stable aqueous dispersion. A) a reaction product of a polyepoxy resin and a cationizing agent; b) a polycondensate of a polycarboxylic acid and a polyamine (see U.S. Pat. No. 2,450,940) protonated with an acid; c) a polyisocyanate
(A) Poly (hydroxylated) compounds and polyols and mono or polyamine polyadducts obtained by protonation with an acid; (d) Hydroxy and amino group-containing copolymers of acrylic or vinyl monomers (protonated with an acid) JP-B-45-12395 and JP-B-45-12396), and e) protonated product of an adduct of a polycarboxylic acid resin and an alkyleneimine with an acid (see U.S. Pat. No. 3,403,088). Can be Of these, products obtained by reacting a cationizing agent with an epoxy group of a polyepoxide resin obtained from a polyphenol compound and epichlorohydrin, which are included in a), are preferred because of their excellent anticorrosion properties of the coating film. .

The polyepoxide resin (a) is a compound having two or more epoxy groups in one molecule.
Suitable are those having a number average molecular weight of from 00, preferably 800 to 2000, including, for example, the polyglycidyl ethers of polyphenol compounds obtained by reacting polyphenol compounds with epichlorohydrin. You. Examples of the polyphenol compound usable here include bis (4-hydroxyphenyl)-
2,2-propane, 4,4'-dihydroxybenzophenone, bis (4-hydroxyphenyl) -1,1-ethane, bis- (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-tert -Butyl-phenyl) -2,2-propane, bis (2-hydroxybutyl) methane, 1,5-dihydroxynaphthalene, bis (2,4-dihydroxyphenyl) methane, tetra (4
-Hydroxyphenyl) -1,1,2,2-ethane,
4,4'-dihydroxydiphenyl ether, 4,4 '
-Dihydroxydiphenyl sulfone, phenol novolak, cresol novolak and the like. These include polyols, polyether polyols, polyester polyols, polyamidoamines, polycarboxylic acids,
Also included are those partially reacted with a polyisocyanate compound or the like and those obtained by graft polymerization of ε-caprolactone, acrylic monomer, or the like.

The base resin having a hydroxyl group and a cationic group can be obtained, for example, by reacting most or all of the epoxy groups of these polyepoxide resins with a cationizing agent.

Examples of the cationizing agent include amine compounds such as primary amines, secondary amines, tertiary amines, and polyamines, which are reacted with these epoxy groups to form secondary amino groups, tertiary amines, and tertiary amines. A cationic group such as a quaternary amino group or a quaternary ammonium base is introduced into a cationized resin. Specifically, as the primary amine compound, for example, methylamine, ethylamine, n-propylamine, isopropylamine, monoethanolamine, n-amine
Primary compounds such as propanolamine and isopropanolamine;
Secondary amine compounds; Examples of the secondary amine compounds include secondary amines such as diethylamine, diethanolamine, di-n-propanolamine, diisopropanolamine, N-methylethanolamine, N-ethylethanolamine and the like.
Tertiary amine compounds such as triethylamine, triethanolamine, N, N-dimethylethanolamine, N-methyldiethanolamine, N, N-diethylethanolamine and N-ethyldiethanolamine; , For example, ethylenediamine,
Examples thereof include polyamines such as diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, methylaminopropylamine, dimethylaminoethylamine, and dimethylaminopropylamine.

In addition to these amine compounds, a basic group formed by using a basic compound such as ammonia, hydroxyamine, hydrazine, hydroxyethylhydrazine, N-hydroxyethylimidazoline as a cationizing agent is protonated with an acid. May be a cationic group. Acids that can be used include formic acid, acetic acid, glycolic acid,
Water-soluble organic carboxylic acids such as lactic acid are preferred.

The hydroxyl group of these cationic resins may be, for example, a reaction of an alkanolamine in the above-mentioned cationizing agent, a reaction of a ring-opened product of caprolactone which may be introduced into an epoxy resin and a reaction of a polyol. Primary hydroxyl group to be introduced; secondary hydroxyl group in epoxy resin; etc. Among them, primary hydroxyl group introduced by reaction with alkanolamine has excellent crosslinking reactivity with a curing agent. It is preferred.

The content of the hydroxyl group in the base resin having a hydroxyl group and a cationic group is from 20 to 5,0 in hydroxyl equivalent.
00, particularly preferably 100 to 1,000 mg KOH / g, and particularly preferably a primary hydroxyl equivalent of 200 to 1,000 mg KOH / g.
OH / g is preferred. In addition, the content of the cationic group,
It is preferably at least the minimum necessary to stably disperse the base resin in water, and it is generally preferably in the range of 3 to 200, particularly 10 to 80 in terms of KOH (mg / g solid content) (amine value). The base resin does not contain free epoxy groups in principle. It is preferable that the cationic group in these base resins is neutralized with an acidic compound such as acetic acid, formic acid, lactic acid, or phosphoric acid, and then dispersed and mixed in water. The pH of the aqueous dispersion is 3 to 9, particularly A range from 5 to 7 is suitable.

As a curing agent, a block polyisocyanate compound obtained by reacting and blocking all of the isocyanate groups of a polyisocyanate compound with a volatile active hydrogen compound (blocking agent) is particularly preferable. When heated above a predetermined temperature, the blocking agent is dissociated and the original isocyanate group is regenerated to participate in a crosslinking reaction with the base resin.

The polyisocyanate compound is a compound having two or more free isocyanate groups in one molecule, for example, hexamethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate. Diisocyanates such as diisocyanate, dimer acid diisocyanate and lysine diisocyanate; isophorone diisocyanate
G, methylene bis (cyclohexyl isocyanate),
Alicyclic diisocyanates such as methylcyclohexane diisocyanate, cyclohexane diisocyanate and cyclopentane diisocyanate; xylylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate Aromatic diisocyanates such as naphthalene diisocyanate and toluidine diisocyanate; urethanized adducts of these polyisocyanate compounds;
Biuret type adducts, isocyanuric ring type adducts; and the like.

Examples of the blocking agent include phenol-based blocking agents, alcohol-based blocking agents, active methylene-based blocking agents, mercaptan-based blocking agents, acid amide-based blocking agents, imide-based blocking agents, and amine-based blocking agents. And imidazole-based blocking agents, urea-based blocking agents, carbamic acid-based blocking agents, imine-based blocking agents, oxime-based blocking agents, sulfite-based blocking agents, and lactam-based blocking agents.

The block polyisocyanate compound is obtained by reacting these polyisocyanate compounds with an active hydrogen compound (blocking agent) by a known method, and substantially free isocyanate groups are present. do not do.

The composition ratio of the base resin and the curing agent is 40 to 90%, preferably 50 to 80%, and the latter is 60 to 10%, especially 50 to 20%, based on the total solid weight of both components.
% Is preferred.

As the coloring pigment, the rust-preventive pigment and the extender pigment, any pigment can be used without particular limitation as long as it is a pigment used in a cationic electrodeposition coating, for example, coloring pigments such as titanium oxide, carbon black and red iron oxide; Rust preventive pigments such as aluminum phosphomolybdate and aluminum tripolyphosphate;
Extenders such as clay, mica, barita, calcium carbonate, and silica; The blending amount of these pigments is
Per 100 parts by weight of the total solid content of the base resin and the curing agent,
It is preferably in the range of 1 to 200 parts by weight, especially 3 to 150 parts by weight.

The cationic electrodeposition paint is composed of these base resins,
It contains a crosslinking agent and a pigment, and can be further prepared by neutralizing the cationic group in the base resin with an acidic compound such as acetic acid, formic acid, lactic acid, or phosphoric acid, and then dispersing and mixing in water. The pH of the aqueous dispersion is preferably in the range of 3 to 9, particularly 5 to 7, and the resin solid content concentration is suitably 5 to 30% by weight.

In the cationic electrodeposition coating composition, in addition to the above-mentioned components, a curing catalyst, an anti-settling agent, and the like can be further appropriately added, if necessary.

Among them, the curing catalyst is effective for accelerating the crosslinking reaction between the base resin and the curing agent. Examples thereof include tin octoate, dibutyltin dilaurate, dibutyltin dibenzoate, lead acetate, and silica. Lead acid, bismuth lactate, tin,
Copper, bismuth, zinc compound, zinc formate, zinc octoate, and the like are included, and the compounding amount thereof is suitably in the range of 0.1 to 10 parts by weight per 100 parts by weight of the total of the base resin and the curing agent. .

It is preferable that the cationic electrodeposition paint is prepared by preparing a dispersion paste of the above pigment in advance and mixing and dispersing the paste with a base resin and a curing agent.

The pigment dispersion paste is prepared by previously dispersing the above-mentioned coloring pigment, rust-preventive pigment, extender pigment and the like in fine particles. For example, a pigment dispersing resin, a neutralizing agent and pigments, and Accordingly, a pigment paste can be prepared by blending a bismuth compound and subjecting it to a dispersion treatment in a dispersion mixer such as a ball mill, a sand mill or a pebble mill. Organic acids such as acetic acid, formic acid, and lactic acid can be used as the neutralizing agent. Known resins can be used as the pigment dispersing resin. For example, a base resin having a hydroxyl group and a cationic group and a surfactant can be used. Further, a tertiary amine type, a quaternary ammonium salt type, and a tertiary sulfonium salt type can be used. Such resins can be used as the dispersing resin.
Examples of the surfactant include nonionic surfactants such as acetylene glycol-based, polyethylene glycol-based, and polyvalent alcohol-based surfactants having an HLB in the range of 3 to 18, preferably 5 to 15. . The amount of the dispersant used is 1 to 150 parts by weight, especially 10 to 100 parts by weight of the pigment.
A range of 100 parts by weight is preferred. The solids content of the pigment dispersion paste is 20 to 80% by weight, especially 30 to 6%.
0% by weight is suitable.

The cationic electrodeposition paint is preferably prepared by preparing a dispersion paste of the above-mentioned pigment in advance and mixing and dispersing it with a base resin and a curing agent. The fraction content is suitably in the range of 5 to 30% by weight.

The composition has a layered carbon compound having a maximum particle size of 5
As a method for incorporating the powder in the form of fine powder having a particle size of μm or less, for example, method 1): the layered carbon compound is finely divided by mixing and dispersing it alone with a resin for dispersion and deionized water into a paste, and the resulting mixture is dispersed in a pigment. 2): A method in which a layered carbon compound alone is mixed and dispersed in a paste with a dispersing resin and deionized water together with a pigment in the step of producing a pigment dispersion paste. Further, a method of pulverizing the layered carbon compound in the step of dispersing and then blending it with the cationic electrodeposition coating material may be mentioned, but the method is not limited thereto.

In the method 1), the layered carbon compound alone is charged together with a dispersing resin and deionized water into a dispersion mixer such as a ball mill, a sand mill or a pebble mill, and the maximum particle size of the layered carbon compound is 5 μm or less, preferably This is carried out by pulverizing the powder to a size of 2 μm or less to form a paste, and blending it with the already prepared pigment dispersion paste in a cationic electrodeposition paint. As the dispersing resin, for example, the above-described base resin having a hydroxyl group and a cationic group, a surfactant, and the like can be used, and further, a resin such as a tertiary amine type, a quaternary ammonium salt type, and a tertiary sulfonium salt type can be used. It can be used as a dispersing resin. As the surfactant, for example, H
Nonionic surfactants such as acetylene glycols, polyethylene glycols, and polyhydric alcohols having an LB in the range of 3 to 18, preferably 5 to 15 are mentioned. The ratio of the layered carbon compound at the time of pulverization is 30 to 100 parts by weight, particularly 4
A range of 0 to 80 parts by weight is preferred. The solid content of the dispersion paste is suitably from 20 to 80% by weight, especially from 30 to 60% by weight.

In the method 2), the lamellar carbon compound alone is dispersed in the form of a paste, and the lamellar carbon compound is dispersed together with the pigment in the step of producing a pigment-dispersed paste of a pigment such as a color pigment. It is carried out by performing fineness and then blending it with the cationic electrodeposition paint. In method 2, it is not necessary to pulverize the layered carbon compound to a maximum particle size of 5 μm or less only in the step performed according to method 1), and the layered carbon compound has a maximum particle size of 5 μm or less after the next pigment dispersing step. Is preferably ground to 2 μm or less.

In the present composition, the content of the layered carbon compound thus finely pulverized until the maximum particle size becomes 5 μm or less, preferably 2 μm or less, is 100% by weight of the total solid content of the base resin and the curing agent. 0.2 to 2.5 per part
Parts by weight, especially in the range from 0.5 to 1.5 parts by weight, are suitable.

Further, the composition preferably contains a magnesium silicate extender in addition to the layered carbon compound. Examples of the magnesium silicate extender include talc (talc powder) and asbestos, and talc is particularly preferred. These are all known as extenders for paints, and their maximum particle size is usually 2
0 μm or more. The present composition is characterized in that it is pulverized to a maximum particle size of 5 μm or less, preferably 2 μm or less. This pulverization can be carried out simultaneously or separately in the presence of a layered carbon compound.

In the present composition, the content of the magnesium silicate extender finely pulverized to a maximum particle size of 5 μm or less, preferably 2 μm or less, is determined by the total solid content of the base resin and the curing agent. Per 100 parts by weight,
A range of 0.2 to 2.5 parts by weight, especially 0.5 to 1.5 parts by weight, is suitable. It is preferable to include a finely divided magnesium silicate extender having a maximum particle size of 5 μm or less, since the corrosion resistance of the cationic electrodeposition coating film can be improved.

[0034]

EXAMPLES Examples and comparative examples according to the present invention will be described below. All parts and percentages are based on weight, and the thickness of the coating is for the cured coating.
The present invention is not limited to only these examples.

1. Production of pigment dispersion paste (A-1): 3.13 parts of epoxy tertiary amine type dispersing resin (Note 1), 1.0 part of graphite having a maximum particle size of 40 μm or more (the same applies hereinafter), 10 parts of 10% acetic acid aqueous solution ( Neutralizer)
1.87 parts and 1.0 parts of deionized water were mixed, dispersed in a ball mill for 10 hours, and then taken out to obtain a pigment dispersion paste (A-1) having a maximum graphite particle size of 15 μm.

(Note 1) Epoxy tertiary amine type dispersing resin: In a flask, 398 parts of ethylene glycol monobutyl ether, "EHPE-3150" (trade name, manufactured by Daicel Chemical Industries, Ltd., alicyclic epoxy having an epoxy equivalent of 180) Resin), 900 parts, 371 parts of an amine compound (Note 2), and 1651 parts of an epoxyamine product (Note 3) were charged, gradually heated with stirring, reacted at 150 ° C., and it was confirmed that the epoxy equivalent became 0. Upon confirmation, an epoxy-based tertiary amine-type dispersing resin was obtained.

(Note 2) Amine compound: A reaction vessel was charged with 285 parts of stearic acid, 104 parts of hydroxyethylaminoethylamine and 80 parts of toluene, and gradually heated while mixing and stirring, while removing toluene as necessary. After separation and removal of 18 parts of reaction water, the remaining toluene was removed under reduced pressure to obtain an amine compound. The amine value was 150 and the freezing point was 76 ° C.

(Note 3) Epoxyamine product: 105 parts of diethanolamine, epoxy equivalent of 190 in a flask.
An epoxyamine product obtained by blending 760 parts of bisphenol A diglycidyl ether, 456 parts of bisphenol A and 330 parts of ethylene glycol butyl ether, and reacting the mixture at 150 ° C. until the residual amount of epoxy groups becomes zero. Solid content 80%.

(A-2): Dispersion was carried out in the same manner as in the above-mentioned pigment dispersion paste (A-1), except that the amount of graphite was increased to 2.0 parts and the amount of deionized water was adjusted. A pigment dispersion paste (A-2) having a particle size of 18 μm was obtained.

(A-3): Talc having the same composition as the pigment-dispersed paste (A-1) and a maximum particle size of 40 μm or more (the same applies hereinafter)
Dispersion was carried out in the same manner as in the above (A-1) except that 2.0 parts was added, and the amount of deionized water was adjusted, to obtain a pigment dispersion paste (A-3) having a maximum particle size of graphite and talc of 15 μm. ) Got.

These pigment dispersion pastes (A-1) to (A
Table 1 shows the composition and amount of -3).

[Table 1]

(B-1): Epoxy tertiary amine type dispersing resin (Note 1) 2.5 parts, titanium oxide 14.5 parts, purified clay 7.0 parts, organic tin 1.0 part, pigment dispersion 7.0 parts of paste (A-1), 10% acetic acid aqueous solution (neutralizing agent)
1.5 parts and 17.41 parts of deionized water in a ball mill 2
The mixture was dispersed for 0 hour, and then taken out to obtain a pigment-dispersed paste (B-1) having a maximum particle size of the pigment and graphite of 2 μm.

(B-2): "Pigment dispersion paste (A-1)
7.0 parts "to" 9.0 parts of pigment-dispersed paste (A-2) "
And the dispersion was carried out in the same manner as the pigment dispersion paste (B-1) except that the amount of deionized water was adjusted, to obtain a pigment dispersion paste (B-2) having a maximum particle size of the pigment and graphite of 2 μm.

(B-3): "Pigment dispersion paste (A-1)
7.0 parts ”to“ Pigment-dispersed paste (A-3) 1 ”
1.0 part ", and adjusting the amount of deionized water, in the same manner as in the pigment dispersion paste (B-1),
A pigment dispersion paste (B-3) having a maximum particle size of the pigment and graphite of 2 μm was obtained.

These pigment dispersion pastes (B-1) to
Table 2 shows the composition and the amount of (B-3).

[0046]

[Table 2] Table 2

(C-1): Epoxy tertiary amine type dispersing resin (Note 1) 5.63 parts, titanium oxide 14.5 parts, purified clay 7.0 parts, organic tin 1.0 part, carbon black 0.46 parts, 10% acetic acid aqueous solution (neutralizing agent) 3.37 parts,
17.97 parts of deionized water was added, and the mixture was dispersed in a ball mill for 20 hours and then taken out to obtain a pigment-dispersed paste (C-1) having a maximum pigment particle size of 2 μm or less.

(C-2): "Carbon black 0.46
Parts) to “1.0 parts of graphite”, and dispersing in the same manner as in the pigment dispersion paste (C-1) except that the amount of deionized water is adjusted. The maximum particle diameter of the pigment and graphite is 12 μm. A dispersion paste (C-2) was obtained.

(C-3): Dispersion was carried out in the same manner as for the pigment dispersion paste (C-2) except that the amount of graphite was changed to 2.0 parts and the amount of deionized water was adjusted. A pigment dispersion paste (C-3) having a diameter of 12 μm was obtained.

These pigment dispersion pastes (C-1) to
Table 3 shows the composition and the amount of (C-3).

[0051]

[Table 3]

2. Examples and Comparative Examples Example 1 50.9 parts of pigment-dispersed paste (B-1) were added to 297 parts of cationic electrodeposition emulsion (Note 4), and deionized 29.
By adding 7.1 parts, a cationic electrodeposition coating composition having a solid content of 20% was obtained.

(* 4) Emulsion for cationic electrodeposition:
"Epicoat 828" (product name, epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd.) 1010 parts, bisphenol A39
0 parts and dimethylbenzylamine 0.2 parts,
The reaction was carried out at ℃ until the epoxy equivalent reached 800. Next, 260 parts of ε-caprolactone and 0.03 part of tetrabutoxytitanium were added, the temperature was raised to 170 ° C., sampling was performed over time while maintaining this temperature, and the amount of unreacted ε-caprolactone in infrared absorption spectrum measurement was measured. The temperature was lowered to 120 ° C. when the conversion was 98% or more. Next, 160 parts of diethanolamine and 65 parts of methyl isobutyl diketiminate of diethylenetriamine were added and reacted at 120 ° C. for 4 hours, 420 parts of butyl cellolub were added, and an amine addition plastic modification having an amine value of 58 and a resin solid content of 80% was added. An epoxy resin was obtained. Next, 87.5 parts of this amine-added plastically modified epoxy resin (70 parts in resin solids), 33.3 parts of a methylethylketoxime blocked product of hexamethylene diisocyanurate as a crosslinking agent (30 parts in resin solids), LSN- 1
05 (trade name, dibutyltin dibenzoate, solid content 40%, manufactured by Sankyoki Gosei Co., Ltd.) 2.5 parts, 10% acetic acid aqueous solution 1
After mixing 5 parts and uniformly stirring, 156 parts of deionized water was added dropwise with vigorous stirring over about 15 minutes to obtain an emulsion for cationic electrodeposition paint having a solid content of 34.0%. .

Example 2 52.7 parts of pigment dispersion paste (B-2) and 30 parts of deionized water were added to 297 parts of the cationic electrodeposition emulsion (Note 4).
0.3 part was added to obtain a cationic electrodeposition coating composition having a solid content of 20%.

Example 3 5297 parts of a pigment dispersion paste (B-3) were added to 297 parts of a cationic electrodeposition emulsion (Note 4), and 30 parts of deionized water were used.
By adding 3.4 parts, a cationic electrodeposition coating composition having a solid content of 20% was obtained.

Comparative Example 1 A pigment dispersion paste (C-1) was added to 49.9 parts of deionized water 29 in 297 parts of a cationic electrodeposition emulsion (Note 4).
By adding 5.3 parts, a cationic electrodeposition coating composition having a solid content of 20% was obtained.

COMPARATIVE EXAMPLE 2 297 parts of a cationic electrodeposition emulsion (Note 4), 50.9 parts of a pigment dispersion paste (C-2), 29 deionized water
7.1 parts were added to obtain a cationic electrodeposition coating composition having a solid content of 20%.

Comparative Example 3 52.7 parts of a pigment dispersion paste (C-3) and 30 parts of deionized water were added to 297 parts of a cationic electrodeposition emulsion (Note 4).
0.3 part was added to obtain a cationic electrodeposition coating composition having a solid content of 20%.

3. Performance test results Table 4 shows the test results of the cationic electrodeposition paints obtained in the examples and comparative examples. The test method in Table 4 is as follows.

Horizontal surface finish: The horizontal portion of the L-shaped test plate bent in advance is immersed in a bath so that the distance between the vertical portion and the counter electrode is 150 cm, and the bath temperature is 28 ° C.
In the above, the current was applied for 2 minutes at a load voltage such that the film thickness became 20 μm, the switch was turned off, the device was left as it was in a bath for 3 minutes, and then the current was applied for another 1 minute. Thereafter, the test plate was pulled up, washed with water, heated and cured at 170 ° C. for 20 minutes, and the coated surface of the horizontal portion was visually evaluated (◎: no occurrence of gloss and gloss shrinkage observed: slight gloss shrinkage). The occurrence is observed, Δ: occurrence of gloss and gloss are observed, ×: occurrence of gloss and gloss are remarkable).

The throwing power: Performed by a pipe method.
An SPC mild steel plate (0.4 × 15 × 350 mm) obtained by placing an electrodeposition coating material up to a height of 300 mm in a stainless beaker (inner diameter 100 mm, height 350 mm) placed on a magnetic stirrer and treating with zinc phosphate. ) Is a stainless steel pipe (inner diameter 16mm, height 350mm)
The object inserted into the bath is put in a bath and placed under a predetermined condition (bath temperature 28).
C., an applied voltage of 250 V, and an energization time of 3 minutes), and the coating is cured by heating at 170 ° C. for 20 minutes, and the height of the coating applied from the lower end of the SPC mild steel sheet (c
m) was measured on both sides of the test plate, and the average value was determined.

Salt water immersion test: hot-dip galvanized steel sheet (0.
(8 × 150 × 70 mm) was immersed, and electrodeposition coating was performed using this as a cathode. Next, the obtained painted product is pulled out of the bath paint, washed with water, and baked at ambient temperature.
It was baked using an electric hot air drier at two levels of 160 ° C. × 10 minutes and 170 ° C. × 20 minutes to form an electrodeposition coating film. Make a cross cut wound with a cutter knife on the obtained coating film,
Furthermore, the result when immersed in a 5% saline solution at 55 ° C. for 10 days was evaluated (◎: the maximum width of rust and blisters was larger than the cut width)
Less than 3mm, ○: The maximum width of rust and blisters is 3mm or more and less than 4mm from the cut part, Δ: The maximum width of rust and blisters is 4mm from the cut part
Not more than 6 mm, ×: the maximum width of rust and blisters is 6 from the cut part
mm or more).

[0063]

[Table 4] Table 4

[Procedure amendment]

[Submission date] October 27, 2000 (2000.10.
27)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

The pigment dispersion paste is prepared by previously dispersing the above-mentioned coloring pigment, rust-preventive pigment, extender pigment and the like in fine particles. For example, a pigment dispersing resin, a neutralizing agent and pigments, and Accordingly, a pigment paste can be prepared by blending a bismuth compound and subjecting it to a dispersion treatment in a dispersion mixer such as a ball mill, a sand mill or a pebble mill. Organic acids such as acetic acid, formic acid, and lactic acid can be used as the neutralizing agent. Known resins can be used as the pigment dispersing resin. For example, a base resin having a hydroxyl group and a cationic group and a surfactant can be used. Further, a tertiary amine type, a quaternary ammonium salt type, and a tertiary sulfonium salt type can be used. Such resins can be used as the dispersing resin.
Examples of the surfactant include nonionic surfactants such as acetylene glycol-based, polyethylene glycol-based, and polyvalent alcohol-based surfactants having an HLB in the range of 3 to 18, preferably 5 to 15. . The amount of the dispersant used is 1 to 150 parts by weight, especially 10 to 100 parts by weight of the pigment.
A range of 100 parts by weight is preferred. The solids content of the pigment dispersion paste is 20 to 80% by weight, especially 30 to 60% by weight.
% By weight is suitable.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction contents]

Horizontal surface finish: The horizontal part of the L-shaped test plate which has been bent in advance is immersed in a bath so that the distance between the vertical part and the counter electrode is 150 mm, and the bath temperature is 28 ° C.
In the above, the current was applied for 2 minutes at a load voltage such that the film thickness became 20 μm, the switch was turned off, the device was left as it was in a bath for 3 minutes, and then the current was applied for another 1 minute. Thereafter, the test plate was pulled up, washed with water, heated and cured at 170 ° C. for 20 minutes, and the coated surface of the horizontal portion was visually evaluated (◎: no occurrence of gloss and gloss shrinkage observed: slight gloss shrinkage). The occurrence is observed, Δ: occurrence of gloss and gloss are observed, ×: occurrence of gloss and gloss are remarkable).

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takeshi Yawada 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside Kansai Paint Co., Ltd. (72) Insulator Midou Kawachi Sho 4-1-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa No. Kansai Paint Co., Ltd. F term (reference) 4J038 DB001 GA03 HA036 HA156 HA456 KA20 NA23 NA24 PA04 PB07 PC02

Claims (5)

[Claims] 1. A cationic electrodeposition coating composition comprising a layered carbon compound having a maximum particle size of 5 μm or less. 2. A cationic electrodeposition coating composition comprising a layered carbon compound having a maximum particle size of 5 μm or less and a magnesium silicate extender. 3. An aqueous dispersion paste obtained by mixing and dispersing a composition containing a layered carbon compound, a dispersing resin and deionized water, and containing a layered carbon compound having a maximum particle size of 5 μm or less. Characteristic cationic electrodeposition coating composition. 4. A layered carbon having a maximum particle size of 5 .mu.m or less, which is obtained by mixing an aqueous dispersion paste obtained by mixing and dispersing a compound containing a layered carbon compound, a magnesium silicate extender, a dispersing resin and deionized water. A cationic electrodeposition coating composition comprising a compound and a magnesium silicate extender. 5. The cationic electrodeposition coating composition according to claim 1, wherein the layered carbon compound is graphite.