JP2007197688A - Electrodeposition paint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeposition paint excellent in anticorrosion properties of a coated film, finishing quality, paint stability, etc. <P>SOLUTION: This electrodeposition paint comprises particles of at least one kind of metal compounds selected from bismuth hydroxide, zirconium compounds and tungsten compounds, and has an average particle diameter of the metal compound particles of 1-1,000 nm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrodeposition paint excellent in anticorrosiveness, finish, and paint stability of a coating film.

  Electrodeposition coatings form coatings with excellent coating performance such as anti-corrosion and finishing properties, so they are widely used in application fields where these performances are required, for example, painting automobile bodies and parts. Yes.

  Electrodeposition paints have been formulated with rust preventives such as lead compounds and chromium compounds to further improve their corrosion resistance, but these are extremely harmful and have problems in their use as a countermeasure against pollution. It was. For this reason, various studies have been made on non-toxic or low-toxic rust preventives that replace these lead compounds and chromium compounds.

  For example, Patent Document 1 (= EP-A-0509437) discloses an electrodeposition coating composition containing a dialkyltin aromatic carboxylate and a bismuth compound or a zirconium compound. Discloses an electrodeposition coating composition containing a compound selected from the group consisting of bismuth silicate, bismuth silicomolybdate, bismuth hydroxide and a zirconium compound. However, these electrodeposition coating compositions are not fully satisfactory in an anticorrosion property, particularly in an exposure resistance test which is a long-term anticorrosion test.

Further, Patent Document 3 discloses a cationic electrodeposition coating material having improved perforated rust resistance by containing bismuth oxide having a maximum particle size of 1.5 μm.
Japanese Unexamined Patent Publication No. 5-65439 JP 2000-290542 A JP 2004-269595 A

  The main object of the present invention is to provide an electrodeposition coating material excellent in anticorrosion properties, finish properties, coating stability and the like of the coating film.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention now have an electrodeposition paint containing particles of at least one metal compound selected from bismuth hydroxide, a zirconium compound and a tungsten compound as a rust preventive component. In addition, when the metal compound particles are blended in the form of fine particles having an average particle diameter of 1 to 1,000 nm, the corrosion resistance of the formed coating film is remarkably improved, particularly in an exposure resistance test which is a long-term corrosion resistance test. Remarkable improvement was observed, and it was also found that electrodeposition coating properties, finish properties, paint stability, etc. on the rust-proof steel plate were improved, and the present invention was completed.

  Thus, the present invention is an electrodeposition coating comprising particles of at least one metal compound selected from bismuth hydroxide, zirconium compounds and tungsten compounds, wherein the metal compound particles have an average particle diameter of 1 to 1000 nm. The present invention provides an electrodeposition coating material characterized by being.

The electrodeposition paint of the present invention includes both anion electrodeposition paints and cationic electrodeposition paints, but cationic electrodeposition paints are particularly preferred from the standpoint of corrosion resistance. Therefore, hereinafter, the cationic electrodeposition paint will be described in more detail.

  The electrodeposition paint of the present invention contains particles of at least one metal compound selected from bismuth hydroxide, a zirconium compound and a tungsten compound as a rust preventive component.

  Examples of the zirconium compound include zirconium oxide, zirconium hydroxide, and zirconium silicate. Examples of the tungsten compound include tungstic acid, iron tungstate, and tungsten oxide. In the present invention, bismuth hydroxide is particularly preferable.

  The electrodeposition paint of the present invention is characterized in that these metal compounds are dispersed and contained in the form of fine particles having an average particle diameter of 1 to 1000 nm, preferably 10 to 700 nm, more preferably 50 to 300 nm.

  In this specification, “average particle diameter” is UPA-EX250 (trade name, Nanotrac particle size distribution measuring device, dynamic light scattering method / laser Doppler method (UPA method), manufactured by Nikkiso Co., Ltd.) 8 to 6,000 nm).

  Such a fine metal compound is generally difficult to form by a ball mill usually used for pigment dispersion, and the metal compound is used in a powerful grinding means such as a planetary ball mill or a homogenizer. Until the metal compound which has an average particle diameter of the inside is obtained, it can obtain by processing normally about 0.5 to 96 hours, Preferably it is 1 to 48 hours, More preferably, it is about 5 to 24 hours.

  The electrodeposition coating composition of the present invention comprising these fine-particle metal compounds is prepared, for example, by previously forming a pulverized product of the metal compound having the above average particle diameter by the above-described means, and using the pulverized product as a color pigment. , Extender pigments, other rust preventive pigments and organic tin compounds, at least one paint additive component, pigment dispersion resin and dispersion medium (water and / or organic solvent), and optionally a surfactant It can be produced by preparing a pigment dispersion paste by mixing and dispersing together with a water-soluble organic acid or the like by a conventional method and then mixing with an emulsion for electrodeposition paint.

  Alternatively, at least one metal compound selected from bismuth hydroxide, a zirconium compound, and a tungsten compound, and at least one paint additive component selected from a color pigment, an extender pigment, another antirust pigment, and an organic tin compound; , A pigment dispersion resin and a dispersion medium (water and / or organic solvent), and optionally, a surfactant, a water-soluble organic acid, etc., and a powerful pulverizing means such as a planetary ball mill or a homogenizer. Then, the dispersed solid particles in the pigment-dispersed paste are co-ground until the average particle size is 1 to 1000 nm, preferably 10 to 700 nm, more preferably 50 to 300 nm to prepare a pigment-dispersed paste. The electrodeposition coating material of the present invention can also be produced by mixing with an emulsion for coating material.

Examples of the color pigment used in the preparation of the pigment dispersion paste include white pigments such as titanium white, zinc white, lithopone, zinc sulfide, and antimony white; carbon black, acetylene black, graphite, iron black, and aniline black. Examples of extender pigments include extender pigments such as clay, mica, barita, talc, calcium carbonate, and silica. Other antirust pigments include, for example, aluminum phosphomolybdate, Examples of the organic tin compound include dibutyltin oxide (DBTO) and dioctyltin oxide (DOTO). In the present invention, the use amount of these organotin compounds is reduced more than usual,
Or its use can be omitted.

  Examples of the pigment dispersion resin used in the preparation of the pigment dispersion paste include tertiary amino group-containing epoxy resins, quaternary ammonium salt type epoxy resins, tertiary amino group-containing acrylic resins, and quaternary ammonium salt type acrylic resins. Of these, tertiary amino group-containing epoxy resins and quaternary ammonium salt type epoxy resins are preferred from the standpoint of corrosion resistance.

  Examples of the surfactant used as necessary include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene derivative, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene Nonionic surfactants such as fatty acid esters, polyoxyethylene alkylamines, and alkyl alkanolamides; anionic surfactants such as fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, and alkyl phosphates; amphoteric such as alkylbetaines Examples of the water-soluble organic acid include acetic acid, formic acid, lactic acid, propionic acid, hydroxyacetic acid, methoxyacetic acid, maleic acid, and fumaric acid.

  Examples of the organic solvent as the dispersion medium include ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as diethyl ether and diethylene glycol monobutyl ether; alcohol solvents such as methanol, ethanol, n-propanol, and isopropanol. .

  The electrodeposition paint of the present invention can contain a base resin and a crosslinking agent as a vehicle component. In the present invention, a cationic electrodeposition paint comprising a cationic resin as a base resin and a blocked polyisocyanate compound as a crosslinking agent is particularly suitable, but the present invention is not limited to this.

  A cationic resin used as a base resin in a cationic electrodeposition coating is a resin having a cationizable group such as an amino group, an ammonium base, a sulfonium base, or a phosphonium base in the molecule. Those usually used as a base resin for coating materials, for example, epoxy resins, acrylic resins, polybutadiene resins, alkyd resins, polyester resins and the like can be mentioned. In particular, an amine-added epoxy resin obtained by addition reaction of an amino group-containing compound with an epoxy resin is suitable.

  Examples of the above amine-added epoxy resins include (1) adducts of epoxy resins with primary mono- and polyamines, secondary mono- and polyamines, or primary and secondary mixed polyamines (for example, US Pat. No. 3,984,299); (2) Adducts of epoxy resins with secondary mono- and polyamines having ketiminated primary amino groups (eg, US Pat. No. 4,017,438). (3) Reactants obtained by etherification of an epoxy resin and a ketiminated hydroxy compound having a primary amino group (for example, see JP-A-59-43013) be able to.

  The epoxy resin used in the production of the above amine-added epoxy resin is a compound having at least one, preferably two or more epoxy groups in one molecule, generally at least 200, preferably 400 to 4,000, Those having a number average molecular weight in the range of 800 to 2,500 and an epoxy equivalent weight in the range of at least 160, preferably 180 to 2,500, more preferably 400 to 1,500 are preferred. What is obtained by reaction of a polyphenol compound and epihalohydrin is preferable.

Here, the “number average molecular weight” is TSK GEL4000HXL + G3000HXL + G2500HXL + G2000HXL (manufactured by Tosoh Corporation) as a separation column according to the method described in JIS K 0124-83, and tetrahydrofuran for GPC is used as an eluent. / Min is a value obtained by calculation from a chromatogram obtained with an RI refractometer and a calibration curve of polystyrene.

  Examples of the polyphenol compound used for forming the epoxy resin include bis (4-hydroxyphenyl) -2,2-propane, 4,4′-dihydroxybenzophenone, and bis (4-hydroxyphenyl) -1,1. -Ethane, bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-2 or 3-tert-butyl-phenyl) -2,2-propane, bis (2-hydroxynaphthyl) methane, tetra (4-hydroxyphenyl) -1,1,2,2-ethane, 4,4′-dihydroxydiphenylsulfone, phenol novolak, cresol novolak, and the like can be mentioned.

  The epoxy resin may be partially reacted with a polyol, a polyether polyol, a polyester polyol, a polyamidoamine, a polycarboxylic acid, a polyisocyanate compound or the like, and a lactone such as ε-caprolactone, An acrylic monomer or the like may be graft-polymerized.

  Examples of the primary mono- and polyamines, secondary mono- and polyamines, and primary and secondary mixed polyamines used in the production of the amine-added epoxy resin of (1) above include monomethylamine, dimethylamine, and monoamine. Mono- or di-alkylamines such as ethylamine, diethylamine, monoisopropylamine, diisopropylamine, monobutylamine, dibutylamine; alkanolamines such as monoethanolamine, diethanolamine, mono (2-hydroxypropyl) amine, monomethylaminoethanol; ethylenediamine And alkylene polyamines such as propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

  Examples of the secondary mono- and polyamines having a ketimized primary amino group used in the production of the amine-added epoxy resin (2) include, for example, the production of the amine-added epoxy resin (1). Among primary mono- and polyamines, secondary mono- and polyamines or primary and secondary mixed polyamines used, compounds having primary amino groups, such as monomethylamine, monoethanolamine, ethylenediamine, diethylenetriamine Examples thereof include ketimine compounds obtained by reacting ketone compounds with the above.

  Examples of the hydroxy compound having a ketiminated primary amino group used in the production of the amine-added epoxy resin (3) include, for example, a first compound used in the production of the amine-added epoxy resin (1). Of primary mono- and polyamines, secondary mono- and polyamines or primary and secondary mixed polyamines, compounds having a primary amino group and a hydroxyl group, such as monoethanolamine, mono (2-hydroxypropyl) amine Examples thereof include a hydroxyl group-containing ketimine compound obtained by reacting a ketone compound with the above.

  In particular, as a base resin, a xylene formaldehyde resin-modified amino group-containing epoxy resin obtained by reacting an xylene formaldehyde resin and an amino group-containing compound with an epoxy resin having an epoxy equivalent of 180 to 3,000, preferably 250 to 2,000. Is preferable from the viewpoint of improving the corrosion resistance of the coating film.

  As the epoxy resin used as a starting material for the production of the amino group-containing epoxy resin, the same epoxy resin as described for the cationic resin can be used.

  The xylene formaldehyde resin is useful for internal plasticization (modification) of the epoxy resin, and can be produced, for example, by subjecting xylene and formaldehyde and further optionally a phenol to a condensation reaction in the presence of an acidic catalyst.

  As said formaldehyde, the compound etc. which generate | occur | produce formaldehyde, such as formalin, paraformaldehyde, and trioxane which are industrially easy to acquire, can be illustrated.

  Furthermore, the above phenols include mono- or divalent phenolic compounds having 2 or 3 reaction sites. Specifically, for example, phenol, cresol, para-octylphenol, nonylphenol, bisphenolpropane, Bisphenol methane, resorcin, pyrocatechol, hydroquinone, para-tert-butylphenol, bisphenol sulfone, bisphenol ether, para-phenylphenol and the like can be mentioned, and these can be used alone or in combination of two or more. Of these, phenol and cresol are particularly preferred.

  Examples of the acidic catalyst used in the condensation reaction of xylene and formaldehyde as described above and further phenols include sulfuric acid, hydrochloric acid, paratoluenesulfonic acid, oxalic acid, etc. Sulfuric acid is preferred.

  The condensation reaction can be performed, for example, by heating to a temperature at which xylene, phenols, water, formalin and the like existing in the reaction system are refluxed, usually about 80 to about 100 ° C. It can be completed in about hours.

  Under the above-mentioned conditions, xylene-formaldehyde resin can be obtained by heat-reacting xylene, formaldehyde and further phenols in the presence of an acidic catalyst.

  The xylene formaldehyde resin thus obtained is generally in the range of 20 to 50,000 centipoise (25 ° C.), preferably 25 to 30,000 centipoise (25 ° C.), more preferably 30 to 15,000 centipoise (25 ° C.). And preferably have a hydroxyl equivalent weight in the range of from 100 to 50,000, in particular from 150 to 30,000, more particularly from 200 to 10,000.

  The amino group-containing compound is a cationic component for introducing an amino group into an epoxy resin to make the epoxy resin cationic, and the same one as used in the production of the cationic resin is used. be able to.

  Although the reaction of the xylene formaldehyde resin and the amino group-containing compound with the epoxy resin can be performed in any order, generally, the xylene formaldehyde resin and the amino group-containing compound are simultaneously reacted with the epoxy resin. Is preferred.

The above addition reaction can be usually performed in a suitable solvent at a temperature of about 80 to about 170 ° C., preferably about 90 to about 150 ° C. for about 1 to 6 hours, preferably about 1 to 5 hours. Examples of the solvent include hydrocarbon solvents such as toluene, xylene, cyclohexane, and n-hexane; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone. Ketone solvents; amide solvents such as dimethylformamide and dimethylacetamide; alcohol solvents such as methanol, ethanol, n-propanol, and iso-propanol; or a mixture thereof.

  The use ratio of each reaction component in the above addition reaction is not strictly limited and can be appropriately changed, but is based on the total solid content mass of the three components of epoxy resin, xylene formaldehyde resin and amino group-containing compound. Therefore, the following range is appropriate. That is, the epoxy resin is generally 50 to 90% by mass, particularly 50 to 85% by mass; the xylene formaldehyde resin is generally 5 to 45% by mass, particularly 6 to 43% by mass; the amino group-containing compound is generally 5 to 25% by mass. %, Particularly 6 to 20% by mass.

  When the above cationic resin has an amino group as a cationizable group, it should be neutralized with an organic carboxylic acid such as formic acid, acetic acid, propionic acid or lactic acid; an acid such as inorganic acid such as hydrochloric acid or sulfuric acid. Can be water-soluble or water-dispersed.

  As the curing agent used in combination with the base resin described above, the blocked polyisocyanate compound, which is an addition reaction product in a substantially theoretical amount of the polyisocyanate compound and the blocking agent, is used for coating curability and corrosion resistance. From the viewpoint of

  As the polyisocyanate compound used here, those conventionally known can be used. For example, tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane-2,4′-diisocyanate, diphenylmethane-4 , 4'-diisocyanate (usually called "MDI"), crude MDI, bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, isophorone diisocyanate, aromatic, aliphatic or alicyclic polyisocyanates Compound; cyclized polymer of these polyisocyanate compounds, isocyanate biuret; ethylene glycol in excess of these polyisocyanate compounds Le, propylene glycol, may be mentioned trimethylolpropane, hexanetriol, terminal isocyanate-containing compounds obtained by reacting a low molecular weight active hydrogen-containing compounds such as castor oil and the like. These can be used alone or in combination of two or more.

  On the other hand, the blocking agent is added and blocked to the isocyanate group of the polyisocyanate compound, and the blocked polyisocyanate compound produced by the addition is stable at room temperature, but the baking temperature of the coating film (usually about 100 to When heated to about 200 ° C., it is desirable that the blocking agent dissociates and free isocyanate groups can be regenerated.

  Examples of the blocking agent that satisfies such requirements include lactam compounds such as ε-caprolactam and γ-butyrolactam; oxime compounds such as methyl ethyl ketoxime and cyclohexanone oxime; phenols such as phenol, para-t-butylphenol, and cresol. Compounds; aliphatic alcohols such as n-butanol and 2-ethylhexanol; aromatic alkyl alcohols such as phenyl carbinol and methyl phenyl carbinol; ether alcohol compounds such as ethylene glycol monobutyl ether and diethylene glycol monoethyl ether Can be mentioned.

  The base resin and the curing agent are generally 50 to 95% by weight, particularly 65 to 85% by weight, and the curing agent is 5 to 50% by weight, particularly 15 based on the total solid content of both. It can be used within a range of ˜35% by mass.

The base resin and curing agent described above are appropriately mixed together with other paint additives to prepare a dissolution varnish, and then in an aqueous medium, formic acid, acetic acid, lactic acid, propionic acid, citric acid, An emulsion for cationic electrodeposition coating can be prepared by adding a neutralizing agent selected from malic acid, sulfamic acid, a mixture of one or more thereof, and dispersing in water.

  Next, the above-mentioned pigment dispersion paste is added to the above emulsion, and if necessary, diluted with an aqueous medium to prepare a cationic electrodeposition paint.

  In the electrodeposition paint thus prepared, the blending amount of at least one metal compound fine particle selected from bismuth hydroxide, zirconium compound and tungsten compound is from the viewpoint of anticorrosion, paint stability, etc. The amount is preferably 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight, more preferably 0.1 to 5 parts by weight per 100 parts by weight of the total solid content of the base resin and the crosslinking agent.

  The cationic electrodeposition paint of the present invention prepared as described above can be applied to the surface of a desired conductive substrate by electrodeposition coating. Electrodeposition coating is generally performed by diluting with a deionized water or the like so that the bath solid concentration is about 5 to about 40% by mass, and further adjusting the pH to 5.5 to 9.0. A coating bath is used, and it can usually be performed under conditions of a bath temperature of 15 to 35 ° C. and an applied voltage of 100 to 400V.

  The thickness of the coating film formed using the cationic electrodeposition coating is not particularly limited, but generally it is preferably within the range of 10 to 40 μm based on the cured coating film. The baking temperature of the coating film is generally about 120 to about 200 ° C., particularly about 140 to about 180 ° C. on the surface of the coating, and the baking time is usually 5 to 60 minutes, preferably It can be about 10 to 30 minutes.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited only to these Examples. “Parts” and “%” are “parts by mass” and “% by mass”.

Example 1 of pulverized production of bismuth hydroxide
100 parts of bismuth hydroxide was charged into PM-400 (Note 1), pulverized for 20 hours using 1000 parts of zirconia beads having a particle diameter of 0.5 mm, and bismuth hydroxide fine particles No. 1 having an average particle diameter of 60 nm. 1 was obtained.
(Note 1) PM-400: Product name, planetary ball mill, manufactured by Retsch.

Production Examples 2-7
Except for changing the pulverization time, the same operation as in Production Example 1 was carried out, and bismuth hydroxide or bismuth oxide pulverized product No. 2-No. 7 was obtained.

Production and production example 8 of pigment dispersion resin
To 1010 parts of Epicoat 828EL (trade name, epoxy resin manufactured by Japan Epoxy Resin Co., Ltd.), 390 parts of bisphenol A, 240 parts of polycaprolactone diol (number average molecular weight of about 1,200) and 0.2 part of dimethylbenzylamine are added, The reaction was continued at 130 ° C. until the epoxy equivalent was about 1,090.

  Next, 134 parts of dimethylethanolamine and 90 parts of acetic acid were added and reacted at 120 ° C. for 4 hours, and then the solid content was adjusted by adding ethylene glycol monobutyl ether. The solid content was 60% and the ammonium salt value was 44 mgKOH. / G ammonium salt type resin for pigment dispersion was obtained.

Production and production example 9 of pigment dispersion paste
In a 1 L ball mill, 5.8 parts of pigment dispersing resin obtained in Production Example 8 (solid content 3.5 parts), 14 parts of titanium white, 7 parts of clay, 1 part of dioctyltin oxide, and pulverization obtained in Production Example 1 Item No. 1 (average particle diameter of bismuth hydroxide 60 nm) and 20.2 parts of deionized water were added and dispersed for 20 hours to obtain a pigment dispersion paste No. 1 having a solid content of 55%. 1 was obtained.

Production Examples 10-22B
With the blending contents, dispersion (grinding) means, and dispersion time shown in Table 2 below, pigment dispersion paste No. 2-No. 15 was obtained. Table 2 also shows the average particle size of the dispersed solid particles in the obtained pigment dispersion paste.

Production and Production Example 23 of Resin for Cationic Electrodeposition Coating : Production of Substrate Resin (A) 240 parts of 50% formalin and 55 parts of phenol in a separable flask having an internal volume of 2 liters equipped with a thermometer, reflux condenser and stirrer Then, 101 parts of 98% industrial sulfuric acid and 212 parts of metaxylene were charged and reacted at 84 to 88 ° C. for 4 hours. After the reaction is completed, the resin phase is separated from the sulfuric acid aqueous phase by standing, then the resin phase is washed with water three times, and unreacted metaxylene is stripped for 20 minutes under the condition of 20-30 mmHg / 120-130 ° C. A xylene formaldehyde resin having a viscosity of 1050 centipoise (25 ° C.) was obtained.

(B) In a flask, Epicoat 828EL (Japan Epoxy Resin Co., Ltd., trade name, epoxy resin, epoxy equivalent 190, molecular weight 350) 1000 parts, bisphenol A
400 parts and 0.2 parts of dimethylbenzylamine were added and reacted at 130 ° C. until the epoxy equivalent was 750. Next, after adding 300 parts of the xylene formaldehyde resin obtained in the above (A), 140 parts of diethanolamine and 65 parts of diethylenetriamine ketimine compound and reacting at 120 ° C. for 4 hours, 420 parts of ethylene glycol monobutyl ether was added and the amine value was increased. 52. A xylene formaldehyde resin-modified amino group-containing epoxy resin having a resin solid content of 80% was obtained.

Production Example 24: Production of curing agent 46 parts of methyl isobutyl ketone was added to 270 parts of Cosmonate M-200 (trade name, Crude MDI, manufactured by Mitsui Chemicals, Inc.), and the temperature was raised to 70 ° C. Furthermore, after slowly adding 281 parts of diethylene glycol monoethyl ether, the temperature was raised to 90 ° C. While maintaining this temperature, sampling was carried out over time, and the reaction was stopped after confirming that there was no absorption of unreacted isocyanate by infrared absorption spectrum measurement. An isocyanate type curing agent was obtained.

Production Example 25: Production of emulsion for electrodeposition paint 87.5 parts of xylene formaldehyde resin-modified amino group-containing epoxy resin having a solid content of 80% obtained in Production Example 23 (solid content 70 parts), and curing obtained in Production Example 24 33.3 parts (solid content 30 parts) and 10% formic acid 8.2 parts were mixed and stirred uniformly, and then 165 parts of deionized water was added dropwise over about 15 minutes with vigorous stirring to obtain a solid content of 34 % Emulsion was obtained.

Production Example 1 of Cationic Electrodeposition Paint
In 294 parts of emulsion obtained in Production Example 25 (solid content: 100 parts), pigment dispersion paste No. 1 obtained in Production Example 9 was added. 1 50 parts (27.5 parts solids) and 293.5 parts deionized water were added, and the cationic electrodeposition paint No. 1 having a solid content of 20% was added. 1 was obtained.

Examples 2-8
Cationic electrodeposition paint No. 1 in the same manner as in Example 1 with the blending ratio shown in Table 3 below. 2-No. 7B was obtained.

Comparative Examples 1-7
Cationic electrodeposition paint No. 1 in the same manner as in Example 1 with the blending ratio shown in Table 4 below. 8-No. 14 was obtained.

Preparation of test plate Using each of the cationic electrodeposition paints obtained in the above examples and comparative examples, the dry film thickness is 20 μm on a cold-rolled steel plate (0.8 mm × 70 mm × 150 mm) subjected to zinc phosphate treatment. Thus, electrodeposition coating was applied, and baking was performed at 170 ° C. for 20 minutes to prepare a test plate, which was tested according to the following test method. The results are shown in Tables 5 and 6 below.
(Note 2) Paint stability:
The top surface of a 3 liter container containing the cationic electrodeposition coating material was opened and stirred at 30 ° C. for 4 weeks, and then the cationic electrodeposition coating material was filtered using a 400 mesh filter screen, and the amount of filtration residue was measured.
○ indicates that the filtration residue is less than 10 mg / L,
Δ is a filtration residue amount of 10 mg / L or more and less than 15 mg / L,
X is the amount of filtration residue is 15 mg / L or more,
It shows that.

(Note 3) Finish:
The surface roughness value (Ra) of the coated surface of the test plate was measured using a Surf Test 301 (trade name, surface roughness meter, manufactured by MITSUTOYO) at a cutoff of 0.8 mm.
◎ has a surface roughness value (Ra) of less than 0.2 μm,
○, the surface roughness value (Ra) is 0.2 μm or more and less than 0.3 μm,
Δ is a surface roughness value (Ra) of 0.3 μm or more and less than 0.4 μm,
X has a surface roughness value (Ra) of 0.4 μm or more,
It shows that.

(Note 4) Anticorrosion:
The electrodeposition coating film was cross-cut with a knife so as to reach the base of the test plate, and using this, a salt spray resistance test was conducted for 1,200 hours according to JISZ-2371. The evaluation was made according to the following criteria based on the rust and blister width from the knife scratch.
◎: The maximum width of rust and blisters is less than 2mm (one side) from the cut part,
○ indicates that the maximum width of rust and blisters is 2 mm or more and less than 3 mm (one side) from the cut part.
△ indicates that the maximum width of rust and blisters is 3 mm or more and less than 4 mm (one side) from the cut part.
X is rust, the maximum width of blisters is 4 mm or more (one side) from the cut part,
It shows that.

(Note 5) Exposure resistance:
After spraying the test plate with WP-300 (trade name, waterborne intermediate coating) manufactured by Kansai Paint Co., Ltd. so that the cured film thickness is 25 μm, it is 140 ° C. × 30 with an electric hot air dryer. Partial baking was performed. Furthermore, after spraying neoamylac 6000 (manufactured by Kansai Paint Co., Ltd., trade name, top coat) on the intermediate coating film so as to have a cured film thickness of 35 μm, it is 140 ° C. in an electric hot air dryer. Baking was performed for 30 minutes to prepare an exposure test plate.

The coating film on the obtained exposure test plate was cross-cut with a knife so as to reach the substrate, and this was exposed outdoors in Okinoerabu Island, Kagoshima Prefecture for a year, then rust and swelling from the knife scratches. Evaluation was made according to the following criteria according to the width.
◎ indicates that the maximum width of rust or blister is less than 2 mm (one side) from the cut part,
○ is that the maximum width of rust or blister is 2 mm or more and less than 3 mm (one side) from the cut part,
△ is the maximum width of rust or blister is 3 mm or more and less than 4 mm (one side) from the cut part,
X indicates that the maximum width of rust or blister is 4 mm or more (one side) from the cut part.
It shows that.

Claims (11)

  An electrodeposition coating comprising particles of at least one metal compound selected from bismuth hydroxide, a zirconium compound and a tungsten compound, wherein the metal compound particles have an average particle diameter of 1 to 1000 nm. Electrodeposition paint.   The electrodeposition paint according to claim 1, which is a cationic electrodeposition paint.   The electrodeposition paint according to claim 1 or 2, wherein the zirconium compound is selected from the group consisting of zirconium oxide, zirconium hydroxide and zirconium silicate, and the tungsten compound is selected from the group consisting of tungstic acid, iron tungstate and tungsten oxide.   The electrodeposition paint according to claim 1 or 2, wherein the metal compound is bismuth hydroxide.   The electrodeposition paint according to any one of claims 1 to 4, wherein the average particle diameter of the metal compound particles is 10 to 700 nm.   6. The metal compound particle according to claim 1, comprising a base resin and a crosslinking agent, and comprising 0.01 to 10 parts by weight of the metal compound particles per 100 parts by weight of the total solid content of the base resin and the crosslinking agent. Electrodeposition paint.   The electrodeposition paint according to claim 6, which is a cationic electrodeposition paint comprising a cationic resin as a base resin and a blocked polyisocyanate compound as a crosslinking agent.   The electrodeposition paint according to claim 6, wherein the base resin is an xylene formaldehyde resin-modified amino group-containing epoxy resin obtained by reacting an xylene formaldehyde resin and an amino group-containing compound with an epoxy resin having an epoxy equivalent of 180 to 3,000.   At least one metal compound selected from bismuth hydroxide, zirconium compounds and tungsten compounds; at least one paint additive component selected from color pigments, extender pigments, other antirust pigments and organotin compounds; and pigment dispersion A pigment dispersion paste comprising a resin for use and a dispersion medium, wherein the average particle size of dispersed solid particles in the pigment dispersion paste is 1-1000 nm.   The pigment dispersion paste according to claim 9, wherein the pigment dispersion resin is a tertiary amino group-containing epoxy resin or a quaternary ammonium salt type epoxy resin.   The electrodeposition paint according to any one of claims 1 to 8, comprising the pigment dispersion paste according to claim 9.