JP2008031210A - Pigment-dispersed paste and cation electrodeposition coating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment-dispersed paste excellent in storage stability, as well as a cation electrodeposition coating material excellent in secondary sagging resistance, electrodeposition coating properties to a rust preventive steel sheet, anticorrosion property and coating material stability. <P>SOLUTION: This pigment-dispersed paste contains: (A) a resin for dispersing a pigment produced by reacting (a) 30 to 70% by mass of a glycidyl etherified product of a novolac-type phenolic resin, (b) 5 to 45% by mass of a cyclic ester compound, (c) 5 to 15% by mass of an amine compound and (d) 1 to 30% by mass of a phenolic compound, based on the total solid content mass of (a), (b), (c) and (d); and (B) a pigment component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pigment dispersion paste and a cationic electrodeposition paint. The present invention particularly relates to a pigment dispersion paste excellent in storage stability, and a cation excellent in secondary sagging resistance, electrodeposition coating on a rust-proof steel sheet, corrosion resistance and paint stability using the pigment dispersion paste. It relates to electrodeposition paint.

  Cationic electrodeposition paints are widely used as undercoat paints for metal products such as automobile bodies because of their excellent paint workability and good rust prevention properties. The pigment dispersion paste used for this electrodeposition paint is usually stored in a tank after production or stored in a warehouse in a drum can. However, if it is not stirred regularly, the pigment will settle down and hinder use. I have come. In particular, when transporting overseas, the pigment dispersion paste contained in the drum can is exposed to a non-stirring state for a long period of time, and thus improvement of the stability of the pigment dispersion paste is urgently needed.

  Conventionally, it has been disclosed that coating properties obtained by electrodeposition coating an electrodeposition coating containing a resin having a quaternary onium base can provide coating properties excellent in corrosion resistance, alkali resistance, etc. (Patent Literature) 1-3). However, the paints of Patent Documents 1 to 3 use a resin having a quaternary onium base, and are particularly insufficient in corrosion resistance.

  Further, a quaternary ammonium group-containing resin obtained by reacting a monoepoxide and an amine compound having at least one organic group containing an acyclic portion having about 8 to 30 carbon atoms is used as a pigment dispersion resin. An example was disclosed (Patent Document 4). In addition, an acid salt of an aliphatic tertiary monoamine, or an acid salt of a tertiary amine which is a reaction product of an epoxidized product and an aliphatic secondary amine, and a resin having a plurality of 2,3-epoxypropoxy groups A quaternary ammonium group-containing resin obtained by reacting is disclosed (Patent Document 5). In addition, an aqueous dispersion of a cationic resin, an acrylic resin-based pigment dispersion resin having an amino group and an alkoxy-terminated polyalkylene oxide structure, and an electrodeposition coating comprising a pigment have been proposed (Patent Document 6).

  Also disclosed is a pigment dispersion resin selected from polyphenols, aliphatic polyols, and polyglycidyl ethers of alicyclic polyols having a primary amino group or tertiary and / or quaternary onium base (Patent Document 7). ).

  Further, in a method for producing a pigment dispersion resin by oniumation of a reaction product of an epoxy resin containing a hydroxyl group and a half-blocked isocyanate, propylene glycol monoalkyl ether having primary OH at the terminal is used as a solvent for oniumation. A method to be used is disclosed (Patent Document 8).

  Further, in a pigment dispersion paste containing an aqueous medium, a pigment, and a pigment dispersant, which is an intermediate composition for preparing a cationic electrodeposition coating composition, an ionic group-containing resin particle and an ionic group are used as the pigment dispersant. The thing containing a containing epoxy resin is proposed (patent document 9).

  Furthermore, a cationic electrodeposition coating composition comprising an amine-modified epoxy resin having an amino group, a blocked isocyanate curing agent and a binder resin emulsion containing a modified epoxy resin having an onium group is disclosed (Patent Document 10).

  Also, an amine-modified bisphenol-type epoxy resin (a) having a quaternary ammonium and an amino group, and a blocked isocyanate curing agent (b), as appropriate, an amine-modified bisphenol-type epoxy resin (c) or an amine-modified novolak-type epoxy resin (d ) Is disclosed (Patent Document 11). Patent Document 11 is not an invention relating to a pigment-dispersed resin.

  However, even if these resins described in Patent Documents 1 to 11 are used in the pigment dispersion paste, they are not satisfactory in terms of secondary sagging resistance, electrodeposition coating properties of rust-proof steel sheets, corrosion resistance, and paint stability. It was.

Japanese Examined Patent Publication No. 53-47143 Japanese Patent Publication No.55-23313 Japanese Patent Publication No.56-2089 JP 59-91164 A JP-A 61-228068 JP-A-8-231901 Japanese Patent Application Laid-Open No. 11-323211 JP 2002-60453 A JP 2002-69358 A JP 2006-2002 JP 2006-2003 A

  The object of the present invention is to solve the problems of the prior art as described above, excellent in the storage stability of the pigment dispersion paste, and resistant to secondary sagging, electrodeposition coating of rust-proof steel sheets, corrosion resistance and It is an object of the present invention to provide a cationic electrodeposition paint that is satisfactory in paint stability.

  As a result of diligent studies to solve the above problems, the present inventors have obtained a pigment dispersion obtained by reacting a glycidyl etherified product of a novolac type phenol resin, a cyclic ester compound, an amine compound and a phenol compound at a predetermined quantitative ratio. The present inventors have found that the problem can be solved by a cationic electrodeposition paint obtained by blending a pigment dispersion paste characterized by containing a resin and a pigment component. The present invention has been completed.

  Therefore, this invention provides the following content, for example.

  1. Glycidyl etherified product of novolak type phenol resin (a), cyclic ester compound (b), amine compound (c) and phenol compound (d) are combined into a total solid of (a), (b), (c) and (d) A pigment obtained by reacting at a ratio of (a) 30 to 70% by mass, (b) 5 to 45% by mass, (c) 5 to 15% by mass, and (d) 1 to 30% by mass based on the partial mass. A pigment dispersion paste comprising a dispersion resin (A) and a pigment component (B).

  2. 2. The mass ratio of the pigment dispersing resin (A) to the pigment component (B) is in the range of pigment dispersing resin (A) / pigment component (B) = 1 / 0.05 to 1/50. Pigment dispersion paste.

  3. Cationic electrodeposition paint comprising 0.1 to 50 parts by mass of the pigment dispersion paste according to 1 or 2 based on the solid content with respect to 100 parts by mass of the solid content of the base resin and the curing agent of the cationic electrodeposition paint. .

  4). 3. The cationic electrodeposition according to 3, comprising 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 2,500 as a base resin. paint.

  5. A coated article obtained by applying the cationic electrodeposition coating composition according to 3 or 4.

  The pigment-dispersed paste of the present invention is excellent in storage stability, and a cationic electrodeposition coating using the pigment-dispersed paste gives a coated article excellent in secondary sagging resistance, electrodeposition coating properties of rust-proof steel plates, and corrosion resistance. Further, since the cationic electrodeposition coating composition of the present invention is excellent in stability, even if it is used for a long time in a coating line where a load such as UF filtration is applied, the finish does not deteriorate.

  Furthermore, the cationic electrodeposition paint of the present invention is left in an unstirred state, for example, left for 1 to 24 hours, and stirred again for a certain time (for example, 1 to 3 hours). A coated article having excellent finish can be provided.

  Hereinafter, preferred embodiments of the present invention will be described. However, it should be understood that the present invention is not limited to these embodiments, and various modifications can be made within the spirit and scope of the present invention.

[Resin for pigment dispersion (A)]
The resin (A) for pigment dispersion used in the present invention contains the glycidyl etherified product (a), the cyclic ester compound (b), the amine compound (c) and the phenol compound (d) of a novolak type phenol resin in the predetermined ratio. It is obtained by reacting with

Glycidyl etherified product of novolac type phenol resin (a)
As the glycidyl etherified product (a) of the novolac type phenol resin, a compound represented by the following formula (1) can be preferably used.

(In the above formula, R ₁ and R ₂ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, an aralkyl group or a halogen atom, and R ₃ is an alkyl having 1 to 10 carbon atoms. Group, aryl group, aralkyl group, allyl group or halogen atom, R ₄ and R ₆ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a glycidyloxyphenyl group, and R ₅ represents A hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, an allyl group or a halogen atom, and n is an integer of 1 to 38)
In the general formula (1), the “alkyl group” is linear or branched, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isoamyl. Hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl group and the like.

The “aryl group” may be either monocyclic or polycyclic, and examples thereof include phenyl and naphthyl groups. Particularly, the phenyl group is preferable, and the “aralkyl group” is an aryl-substituted alkyl group. And includes, for example, benzyl, phenethyl and the like, and benzyl is preferred.
“Halogen atom” includes fluorine, chlorine, bromine and iodine atoms.

The “glycidyloxyphenyl group” represented by R ₄ or R ₆ is a group represented by the following formula (2).

(In the above formula, W represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms)
In the general formula (1), R ₁ and R ₂ are preferably a hydrogen atom, a methyl group, a chlorine atom and a bromine atom, and particularly preferably a hydrogen atom, a methyl group and a bromine atom.

Further, as R ₃ and R ₅ , a methyl group, a tert-butyl group, a nonyl group, a phenyl group, a chlorine atom and a bromine atom are preferable, and a methyl group, a tert-butyl group, a phenyl group and a bromine atom are particularly preferable. is there. Furthermore, R ₄ and R ₆ are preferably hydrogen atoms, and n is particularly preferably 1-8.

  The number average molecular weight of the pigment dispersing resin (A) is generally preferably in the range of about 400 to about 8,000, particularly 600 to 2,000. The pigment dispersing resin (A) preferably has 3.5 to 10 glycidyl groups per molecule, and the epoxy equivalent of the pigment dispersing resin (A) is about 180 to about 2, 000, particularly preferably in the range of 200 to 600.

In this specification, the number average molecular weight is determined according to JIS K0124-83 using TSK GEL4000H _XL + G3000H _XL + G2500H _XL + G2000H _XL (manufactured by Tosoh Corporation) as a separation column and GPC tetrahydrofuran as an eluent. It was obtained by calculation from a chromatogram obtained with an RI refractometer and a standard polystyrene calibration curve at 40 ° C. and a flow rate of 1.0 ml / min.

  The pigment dispersing resin (A) is, for example, the following formula (3)

(Wherein R ₁ , R ₂ and R ₃ are as defined above)
And a bifunctional phenol compound (a-1) represented by the following formula (4)
R ₄ —CHO Formula (4)
(Wherein R ₄ has the same meaning as above)
The aldehyde compound (a-2) and / or the following formula (5)
R ₄ —CO—R ₆ formula (5)
(Wherein R ₄ and R ₆ are as defined above)
It is produced by introducing a glycidyl ether group by further reacting an epihalohydrin (a-5) with a novolak-type phenol resin (a-4) obtained by subjecting a ketone compound (a-3) represented by can do.

  In addition, during or after the reaction for obtaining the novolac type phenol resin (a-4), the following formula (6)

(Wherein R ₇ represents an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, an allyl group or a halogen atom, and R ₁ and R ₂ are as defined above).
A monofunctional phenol compound (a-6) represented by the formula (1) may be used in combination as an end-capping agent.

Specific examples of the group R ₇ in the formula (6) include methyl group, ethyl group, propyl group, n-butyl group, tert-butyl group, pentyl group, hexyl group, nonyl group, ethylene group, propylene group, phenyl Group, benzyl group, chlorine atom, bromine atom and iodine atom, etc., preferably methyl group, tert-butyl group, nonyl group, phenyl group, chlorine atom and bromine atom, especially methyl group, tert-butyl group A phenyl group and a bromine atom are preferred.

  The term “bifunctional” used for the phenol compound of the above (a-1) means that in formula (3), two hydrogen atoms are directly bonded to the ortho position and / or the para position based on the hydroxyl group. Means that These hydrogen atoms undergo a dehydration condensation reaction with the carbonyl group (C═O) in the above components (a-2) and (a-3) to produce a novolak type phenol resin (a-4).

  In addition, the term “monofunctional” used for the phenol compound of component (a-6) means that in formula (6), one hydrogen atom is directly bonded to the ortho or para position with reference to the hydroxyl group. Means that This hydrogen atom forms a terminal of the novolak type phenol resin (a-4) by dehydration condensation reaction with the carbonyl group (C═O) in the component (A-2) or (A-3).

  Examples of the bifunctional phenol compound (a-1) represented by the formula (3) include phenol, p-propenylphenol, o-benzylphenol, 6-n-amyl-n-cresol, o-cresol, p -Cresol, o-ethylphenol, o-phenylphenol, p-phenylphenol, p-tert-pentylphenol, p-tert-butylphenol, o-chlorophenol, p-chlorophenol, 4-chloro-3,5-xylenol O-allylphenol, nonylphenol, o-bromophenol, p-cumylphenol, and the like.

  Examples of the aldehyde compound (a-2) represented by the formula (4) include acetaldehyde and formaldehyde. Alternatively, m- (or p-) hydroxybenzaldehyde may be used as the aldehyde compound (a-2), and after reaction with the component (a-1), this hydroxybenzaldehyde may be glycidyl etherified with epihalohydrin (a-5). .

  In addition, the benzene nucleus of the hydroxybenzaldehyde may be substituted with an alkyl group having 1 to 10 carbon atoms.

  Examples of the ketone compound (a-3) represented by the formula (5) include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

  Furthermore, examples of the epihalohydrin (a-5) include epichlorohydrin and epibromohydrin.

  A novolac-type phenol resin (a-4) is obtained by subjecting the component (a-1) to a condensation polymerization reaction of the component (a-2) and / or the component (a-3). This polycondensation reaction can be carried out according to a known method for producing a novolak type phenol resin.

In the production of the novolak-type phenol resin (a-4), if necessary, during the condensation polymerization reaction of the component (a-1) with the component (a-2) and / or the component (a-3) or Thereafter, the monofunctional phenol compound (a-6) represented by the formula (5) can be reacted as a terminal blocking agent.
Specific examples of the monofunctional phenol compound (a-6) represented by the formula (6) include 2-tert-butyl-4-methylphenol, 2,4-xylenol, 2,6-xylenol, 2 , 4-dichlorophenol, 2,4-dibromophenol, dichloroxylenol, dibromoxylenol, 2,4,5-trichlorophenol, 6-phenyl-2-chlorophenol, and the like.

  The polycondensation reaction of the component (a-6) with the component (a-1), the component (a-2) and / or the component (a-3) can be carried out in the same manner as described above.

The glycidyl etherified product (a) of the novolac-type phenol resin can be obtained by reacting the phenolic hydroxyl group in the novolac-type phenol resin (a-4) with epihalohydrin (a-5) to glycidyl ether. Specifically, for example, a novolac-type phenol resin (a-4) is dissolved in epihalohydrin (a-5) to form a solution, and an aqueous solution of an alkali metal hydroxide is continuously added to the solution. Of water and unreacted epihalohydrin (a-5). The component (a-5) can be separated from the distilled liquid and reused. This reaction is preferably carried out in the presence of an ether solvent such as dioxane or diethoxyethane.
The glycidyl etherified product (a) of the novolak-type phenol resin can be produced as described above, but a commercially available product may be used. As glycidyl etherified products, DEN-438 and DEN-439 (made by Dow Chemical Japan Co., Ltd., trade name); as polyglycidyl etherified products of cresol type novolak resin, EPICRON N-695 (produced by Dainippon Ink Co., Ltd., products) Name), CNE195LB (Changchun Japan Co., Ltd.), EOCN-102S, EOCN-1020 and EOCN104S (Nippon Kayaku Co., Ltd., trade name); BREN-S (Nippon Kayaku Co., Ltd., trade name); long chain Examples of polyglycidyl etherified products of alkyl-modified phenol type novolak resins include ESMB-260 (trade name, manufactured by Sumitomo Chemical Co., Ltd.).

Cyclic ester compound (b)
The cyclic ester compound (b) has the following formula (7)

(In the above formula, R ₈ represents a hydrogen atom or CH ₃ , and n is an integer of 3 to 6)
Specifically, for example, δ-valerolactone, ε-caprolactone, ζ-enalactone, η-caprolactone, γ-valerolactone, δ-caprolactone, ε-enalactone, ξ- Caprolactone is exemplified, and ε-caprolactone is particularly preferable.

  The methylene chain portion derived from the lactone of the cyclic ester compound (b) imparts storage stability and weather resistance to the pigment dispersion resin (A).

Amine compound (c)
The amine compound (c) may be a primary or secondary amine compound having at least one primary hydroxyl group in one molecule. This is useful for introducing a primary hydroxyl group and a basic group into the pigment dispersing resin (A).

  A cationic resin is formed by the reaction of the amino group of the amine compound (c) with the glycidyl group of the glycidyl etherified product (a) of the novolak type phenol resin represented by the formula (1), and the primary resin in the cationic resin is produced. Hydroxyl group and basic group are produced by reaction with conventional bisphenol A type epoxy resin, but water dispersibility is remarkably superior to those groups, and pigment dispersion paste and cation using the pigment dispersion paste are used. Contributes to improving the stability of electrodeposition paints. Furthermore, in the formed coating film, it contributes also to the improvement of anticorrosion property, especially corrosion resistance.

  Specific examples of the amine compound (c) include the compounds exemplified below.

(1) Primary alkanolamines such as monoethanolamine, monopropanolamine, monobutanolamine (2) N-methylethanolamine, N-ethylethanolamine, diethanolamine, di-n- (or iso) -propanolamine, Secondary alkanolamines such as dibutanolamine (3) Adducts (secondary alkanolamines) of the above primary alkanolamines with α, β-unsaturated carbonyl compounds, such as monoethanolamine and N, N- Adducts with dimethylaminopropylacrylamide, adducts of monoethanolamine and hydroxyethyl (meth) acrylate, adducts of monoethanolamine and hydroxypropyl (meth) acrylate, monoethanolamine and hydroxybutyl (meth) acrylate (4) Primary and secondary alkanolamines such as hydroxyethylaminoethylamine (5) One or more selected from hydroxyamine, hydroxyethylhydrazine and hydroxybutylhydrazine and ketone compounds such as dimethyl ketone , Methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, dipropyl ketone and other condensates (secondary alkanolamine)
(6) Following formula (8)

(In the above formula, n is an integer of 1 to 6, and R ₉ represents a hydrocarbon chain having 4 to 36 carbon atoms which may contain a hydroxyl group and / or a polymerizable unsaturated group)
An amine compound in which a primary hydroxyl group, a secondary amino group, and an amide group coexist in one molecule represented by the formula (8) is, for example, an N-hydroxyalkylalkylenediamine and a C5-C37 amine compound. It can be obtained by dehydrating condensation reaction with a monocarboxylic acid. Examples of such diamines include primary hydroxyl groups such as hydroxyethylaminoethylamine, N-hydroxyethylpropylenediamine, N-hydroxyethylbutylenediamine, N-hydroxyethylpentylenediamine, N-hydroxyethylhexylenediamine, and the like. First and second diamines are preferred, and examples of monocarboxylic acids include coconut oil fatty acid, castor oil fatty acid, rice bran oil fatty acid, soybean oil fatty acid, tall oil fatty acid, dehydrated castor oil fatty acid, safflower oil fatty acid, linseed oil Mixed fatty acids such as fatty acids and tung oil fatty acids, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, 12-hydroxystearic acid, Behe Such as acid, and the like.

  The reaction of the diamine with the monocarboxylic acid to obtain the amine compound represented by the above formula (8) is usually performed by mixing both components in an approximately equimolar ratio and using an organic solvent such as toluene or methyl isobutyl ketone. It can be carried out by removing a specified amount of reaction product water, and an amine compound can be obtained by removing the residual organic solvent by a reduced pressure method or the like.

  The amine compound thus obtained generally has an amine value (secondary amine) in the range of 88 to 350 mgKOH / g, particularly 120 to 230 mgKOH / g, and a hydroxyl value (preferably a primary hydroxyl group) of 44. It is preferable to be within the range of -350 mgKOH / g, particularly 60-230 mgKOH / g.

  Of the compounds (1) to (6) described above as the amine compound (c), the primary alkanol secondary amines (2), (3) and (6) are preferred. In particular, it is preferable to use an amine compound represented by the formula (8) (particularly hydroxyethylaminoethyl fatty acid amide) and diethanolamine in order to improve finish and anticorrosion properties.

Phenol compound (d)
As the phenol compound (d), one having at least one, preferably 1 to 5, phenolic hydroxyl groups in one molecule can be used. Specifically, for example, 2,2-bis (p-hydroxyphenyl) propane, 4,4′-dihydroxybenzophenone, 1,1-bis (p-hydroxyphenyl) ethane, 1,1-bis (p-hydroxy) Phenyl) isobutane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, bis (2,4-dihydroxyphenyl) methane, Examples thereof include polyhydric phenol compounds such as 1,1,2,2-tetra (p-hydroxyphenyl) ethane, 4,4-dihydroxydiphenyl ether, 4,4-dihydroxydiphenyl sulfone, phenol novolac, and cresol novolac.

  Furthermore, monophenol compounds such as phenol, nonylphenol, α- or β-naphthol, p-tert-octylphenol, o- or p-phenylphenol can also be used.

  In order to form a coating film having more excellent anticorrosion properties, the phenol compound (d) is particularly bisphenol A [2,2-bis (p-hydroxyphenyl) propane] or bisphenol F [bis (p-hydroxyphenyl). It is preferable to use a reaction product of bisphenols such as) methane] and epichlorohydrin.

  Among these reaction products, in particular, the number average molecular weight is at least 200, preferably in the range of about 800 to about 3,000, and an average of 2 or less, preferably 0. Those represented by the following formulas containing 8 to 1.2 phenolic hydroxyl groups are suitable.

(In the above formula, n is an average number of 0 to 7, and R ₁₀ represents a residue of an active hydrogen compound)
In the above formula, the active hydrogen-containing compound which is a precursor of R ₆ in the general formula (1) includes, for example, amines such as secondary amines; phenols such as nonylphenol; organic acids such as fatty acids. Thiols; alcohols such as alkyl alcohol, cellosolve, butyl cellosolve and carbitol; and compounds such as inorganic acids. Of these, dialkanolamine which is a secondary amine having a primary hydroxyl group, and monophenol such as nonylphenol, phenylphenol and phenol are particularly preferred. In particular, when a primary hydroxyl group-containing amine is used, curability is improved, and when monophenol is used, stability is improved.

  Further, as the phenol compound, for example, 1 mol of a bisphenol A diglycidyl ether type polyepoxide having a molecular weight of 200 or more, preferably 380 to 2,000, and a molecular weight of 200 or more, preferably 200 to 2,000. Reaction of 1 mol of bisphenol A polyphenol within the range of 1 and 1 mol of a compound having active hydrogen in the presence of a catalyst or a solvent, if necessary, at a temperature of 30 to 300 ° C., preferably 70 to 180 ° C. Let

  In addition, as the phenol compound (d), polyols such as dimer diol, ethylene glycol, propylene glycol and butylene glycol; polyether glycols such as polyethylene glycol, polypropylene glycol and polybutylene glycol; polyester polyols such as polycaprolactone; Polycarboxylic acids; polyisocyanates; monoisocyanates; oxides of unsaturated compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide; allyl glycidyl ether, polypropylene glycol diglycidyl ether, 2-ethylhexyl glycidyl ether, methyl glycidyl Has a hydroxyl group such as ether, butyl glycidyl ether, or phenyl glycidyl ether Glycidyl esters of organic acids as fatty acids;; glycidyl ether compounds alicyclic oxirane-containing compounds and the like may also be used those obtained by reacting bisphenol A. Further, a compound obtained by graft polymerization of δ-4-caprolactone, an acrylic monomer or the like to this compound can also be used.

Production of Pigment Dispersing Resin (A) The pigment dispersing resin (A) is, for example, a glycidyl etherified product (a) of a novolac type phenol resin, a cyclic ester compound (b), an amine compound (c) and a phenol compound (d ) At the same time, or by reacting the cyclic ester compound (b) and the amine compound (c) with the glycidyl etherified product (a) of a novolak-type phenol resin and then reacting the phenol compound (d). It is done.

The reaction temperature in the reaction of the glycidyl etherified product of the novolak type phenol resin (a), the cyclic ester compound (b), the amine compound (c) and the phenol compound (d) is usually 50 to 300 ° C. in the presence of an organic solvent, The inside of the range of 70-200 degreeC is especially preferable. The resulting cationic resin composition (A) generally has a number average molecular weight in the range of 1,000 to 20,000, particularly 1,500 to 10,000, and a hydroxyl value of 10 to 1000 mgKOH / g, particularly 50. It is preferable for the coating film performance and the coating stability that it is in the range of ˜300 mg KOH / g and the amine value of 10 to 300 mg KOH / g, particularly 30 to 100 mg KOH / g.
[Production of pigment dispersion paste]
In the pigment dispersion paste, a neutralizing agent and a pigment component (B) are blended with the above-described pigment dispersion resin (A), and a dispersion machine conventionally used such as a ball mill, a pebble mill, a sand mill, or a shaker is used as a dispersion machine. And can be produced by making the particle diameter 15 μm or less, preferably 8 μm or less. Among these, a ball mill is preferable from the viewpoint of workability, and a dispersion time by the ball mill is preferably 1 to 96 hours, and more preferably 10 to 48 hours from the viewpoint of pigment particle size and production man-hour.

  In this specification, the particle size is dispersed based on the degree of dispersion according to JIS K-5400-4.7.1 (1990) distribution diagram, and the distribution density of the particles is observed using a tube gauge. This is a reading of the scale where the grain began to appear.

  As the pigment component (B), those commonly used for electrodeposition paints can be used as well, and examples of the color pigment include carbon black, perylene black, titanium oxide, phthalocyanine blue, phthalocyanine green, and ocher. It is done. When the coating color is black, such as for parts, carbon black and perylene black are preferred. Examples of extender pigments include clay, mica, talc, barium sulfate (varita), and silica. Examples of rust preventive pigments include aluminum phosphomolybdate, aluminum tripolyphosphate, bismuth oxide, bismuth hydroxide, and base. Bismuth carbonate, bismuth nitrate, bismuth silicate, hydrotalcite, zinc compounds and the like can also be used.

  Among these, it is preferable to contain barium sulfate (barita) as an extender for securing the effect of increasing the amount and the gloss of the coating film. The content of barium sulfate (barita) is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the solid content of the base resin and the curing agent of the cationic electrodeposition paint. More preferably, it is 1 to 8 parts by mass. In particular, by using the pigment dispersion resin (A) of the present invention and barium sulfate (varita) in combination, a gloss of 60 ° specular gloss of 85 or more, preferably 90 or more can be obtained.

  The curing catalyst appropriately blended is effective for promoting the crosslinking reaction of the coating film, and examples thereof include dioctyl tin oxide, dibutyl tin oxide, tin octoate, dibutyl tin dilaurate, and dibutyl tin dibenzoate.

  The mass ratio of the pigment dispersing resin (A) to the pigment component (B) is in the range of pigment dispersing resin (A) / pigment component (B) = 1 / 0.05 to 1/50, preferably 1 / 0.5 to 1/30 is good for finishing and paint stability.

  The blending ratio of the pigment dispersion resin (A) used for preparing the pigment dispersion paste is 0.1 to 20 parts by mass, particularly 3 to 15 in total per 100 parts by mass of the solid content of the base resin and the curing agent. It is desirable to be within the range of 5 parts by mass, more particularly 5-12 parts by mass.

[Preparation of cationic electrodeposition paint]
The pigment dispersion paste provided by the present invention can be mixed with an emulsion containing a base resin, a curing agent and the like to form an electrodeposition paint. The electrodeposition paint may be either an anionic type or a cationic type, but in general, a cationic type is preferred from the viewpoint of corrosion resistance.

  Further, as the base resin, for example, any resin for paint such as epoxy resin, acrylic resin, polybutadiene resin, alkyd resin, polyester resin, etc. can be used. The polyamine resin represented by is preferable.

  The amino group-containing epoxy resin is obtained by adding an amine compound to the epoxy resin, and as an epoxy resin used in that case, in particular, from the viewpoint of anticorrosiveness of the coating film, a polyphenol compound and an epihalohydrin, For example, an epoxy resin obtained by reaction with epichlorohydrin is suitable.

  As the polyphenol compound that can be used for the formation of such an epoxy resin, those conventionally used can be used, for example, bis (4-hydroxyphenyl) -2,2-propane (bisphenol A). ), 4,4-dihydroxybenzophenone, bis (4-hydroxyphenyl) methane (bisphenol F), bis (4-hydroxyphenyl) -1,1-ethane, bis (4-hydroxyphenyl) -1,1-isobutane, Bis (4-hydroxy-tert-butylphenyl) -2,2-propane, bis (2-hydroxynaphthyl) methane, tetra (4-hydroxyphenyl) -1,1,2,2-ethane, 4,4-dihydroxy Diphenyl sulfone (bisphenol S), phenol novolak, cresol novolac Etc. The.

  Moreover, as an epoxy resin obtained by reaction of a polyphenol compound and epichlorohydrin, especially the following formula induced | guided | derived from bisphenol A is shown.

(In the above formula, n is 0 to 8)
Those represented by are preferred.

  The epoxy resin can generally have an epoxy equivalent weight in the range of 180 to 2,500, preferably 200 to 2,000, more preferably 400 to 1,500, and is generally at least 200, in particular 400 to 4, Those having a number average molecular weight in the range of 000, more particularly in the range of 800 to 2,500 are suitable.

  Examples of such commercially available epoxy resins include those sold by Japan Epoxy Resins Co., Ltd. under the trade names of Epicoat 828EL, 1002, 1004, and 1007.

  The amine compound is a cationic component that cationizes the epoxy resin by introducing an amino group into the epoxy resin, and contains at least one active hydrogen that reacts with the epoxy group, for example, a primary amino group An amine compound having the following formula is used.

  Examples of the amine compound having a primary amino group include ketiminates such as monoethanolamine, propanolamine, hydroxyethylaminoethylenediamine, hydroxyethylaminopropylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. Can be mentioned.

  The amine compound having the primary amino group may be used in combination with other amine compounds, and as the amine compound that can be used in combination, a secondary amine is particularly preferable, for example, diethylamine, diisopropylamine, diethanolamine, di (2-hydroxy). Propyl) amine, monomethylaminoethanol, monoethylaminoethanol and the like.

  The above epoxy resin can be modified by reacting with xylene formaldehyde resin, caprolactone polyol compound or the like.

  The xylene formaldehyde resin can be produced, for example, by subjecting xylene, formaldehyde and optionally phenols 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. The xylene formaldehyde resin can generally have a viscosity in the range of 20 to 50,000 mPa · s (25 ° C.), preferably 30 to 15,000 mPa · s (25 ° C.), and generally 100 to 50, Preferably having a hydroxyl equivalent weight in the range of 000, in particular 200 to 10,000.

  On the other hand, the caprolactone polyol compound can be obtained by adding caprolactone to a compound containing a plurality of active hydrogen groups, for example, ethylene glycol, propylene glycol, trimethylolpropane and the like.

  In general, the modification of an epoxy resin with a xylene formaldehyde resin or a polycaprolactone polyol compound is preferably performed by simultaneously reacting an amine compound and a modifier with an epoxy group of the epoxy resin.

  The use ratio of the above modifier is not strictly limited and can be appropriately changed according to the application of the coating composition, etc., but generally 5 to 50 mass based on the solid content mass of the epoxy resin. %, Preferably in the range of 10 to 30% by mass. In order to improve the anticorrosion property, an amino group-containing epoxy resin modified with xylene formaldehyde resin is preferable.

  Next, as a hardening | curing agent mix | blended with a cationic electrodeposition coating material, conventionally known hardening | curing agents, such as a blocked polyisocyanate compound and an amino resin, can be used, and a blocked polyisocyanate compound is especially preferable.

  As the polyisocyanate compound, conventionally known compounds can be used. For example, tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane-2,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate. (Usually referred to as “MDI”), crude MDI, bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, isophorone diisocyanate, and the like; Cyclic polymers of cyanate compounds, isocyanate violets; excess amounts of these polyisocyanate compounds include ethylene glycol, 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.

  Examples of the blocking agent include lactam compounds such as ε-caprolactam and γ-butyrolactam; oxime compounds such as methyl ethyl ketoxime and cyclohexanone oxime; phenol compounds such as phenol, para-tert-butylphenol and cresol; n-butanol; Examples thereof include aliphatic alcohols such as 2-ethylhexanol; aromatic alkyl alcohols such as phenyl carbinol and methyl phenyl carbinol; ether alcohol compounds such as ethylene glycol monobutyl ether. Of these, oxime-based and lactam-based blocking agents are blocking agents that dissociate at a relatively low temperature, and are particularly suitable from the viewpoint of low-temperature curability.

  The amount of the base resin and the curing agent used is 60 to 90%, preferably 70 to 85%, and the curing agent is 40 to 10%, preferably 30 to 15% based on the total mass of both. % Range.

  The above-mentioned base resin and curing agent can usually be made into an emulsion by neutralizing it with a water-soluble organic acid such as formic acid, acetic acid, or lactic acid to make it water-soluble or water-dispersed.

  The cationic electrodeposition paint of the present invention is prepared by adding the pigment dispersion paste to the emulsion and blending additives such as an organic solvent, a surfactant, a surface conditioner, and a repellency inhibitor as necessary. In addition, by diluting with deionized water or the like so that the solid content concentration is in the range of 5 to 25% by mass and adjusting the pH in the range of 5.0 to 7.0, A bath of paint can be obtained. Electrodeposition coating can usually be performed under conditions of a bath temperature of 15 to 35 ° C. and an applied voltage of 100 to 400V.

  Examples of the object to be coated include automobile bodies, motorcycle parts, household equipment, other equipment, and the like, and there are no particular limitations as long as it is a metal. Hot-dip galvanized steel sheet, electrogalvanized steel sheet, electrogalvanized steel Layer-plated steel sheet, organic composite plated steel sheet, Al material, Mg material, etc., and after cleaning the surface of these steel plates and cold-rolled steel plate as necessary, such as alkaline degreasing, phosphate chemical conversion treatment, Examples of the surface treatment include chromate treatment.

  Next, the electrodeposition coating film is dried at a coating surface temperature of 110 to 200 ° C., preferably 140 to 180 ° C., preferably 10 to 180 minutes using drying equipment such as an electric hot air dryer or a gas hot air dryer. Preferably, it can be cured by heating for 20 to 50 minutes.

  EXAMPLES Hereinafter, although a production example, an Example, and a comparative example demonstrate this invention further in detail, this invention is not limited only to these examples. In each example, “parts” indicates mass parts, and “%” indicates mass%.

Production Example 1 Pigment Dispersion Resin No. Production Example 1 450 ml of nonylphenol and 960 parts of CNE195LB (Note 3) were charged into a flask equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, and gradually heated with mixing and stirring, and reacted at 160 ° C. . Thereafter, 430 parts of ε-caprolactone is charged, and the temperature is raised to 170 ° C. for reaction. Furthermore, 105 parts of diethanolamine and 124 parts of N-methylethanolamine were reacted to confirm that the epoxy value was 0, and the solid content was adjusted by adding ethylene glycol monobutyl ether, for pigment dispersion having a solid content of 60%. Resin No. One solution was obtained. This pigment dispersing resin No. The hydroxyl value of 1 was 150 mgKOH / g, the amine value was 70 mgKOH / g, and the number average molecular weight was 2,200.

(Note 3) CNE195LB: manufactured by Changchun Japan Co., Ltd., trade name, cresol-type novolac epoxy resin, glycidyl etherified product of novolac-type phenol resin Production Example 2 Pigment Dispersion Resin No. Production Example 2 Into a flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 450 parts of nonylphenol and 960 parts of CNE195LB (Note 3) were charged, and gradually heated with mixing and stirring, and reacted at 160 ° C. . Thereafter, 430 parts of ε-caprolactam is charged, and the temperature is raised to 170 ° C. for reaction. Further, 278 parts of diethanolamine was reacted to confirm that the epoxy value was 0, and the solid content was adjusted by adding ethylene glycol monobutyl ether. Two solutions were obtained. This pigment dispersing resin No. The hydroxyl value of 2 was 200 mgKOH / g, the amine value was 70 mgKOH / g, and the number average molecular weight was 2,300.

Production Example 3 Pigment Dispersing Resin No. Production Example 3 Into a flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 450 parts of nonylphenol and 960 parts of CNE195LB (Note 3) were charged, and gradually heated with mixing and stirring, and reacted at 160 ° C. . Thereafter, 430 parts of ε-caprolactone is charged, and the temperature is raised to 170 ° C. for reaction. Furthermore, 200 parts of N-methylethanolamine was reacted to confirm that the epoxy value was 0, and the solid content was adjusted by adding ethylene glycol monobutyl ether. Three solutions were obtained. This pigment dispersing resin No. 3 had a hydroxyl value of 120 mgKOH / g, an amine value of 70 mgKOH / g, and a number average molecular weight of 2,200.

Comparative Production Example 1 Pigment dispersing resin No. 1 Production Example 4 Into a flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 450 parts of nonylphenol and 960 parts of CNE195LB (Note 3) were charged, and gradually heated with mixing and stirring, and reacted at 160 ° C. . Furthermore, 105 parts of diethanolamine and 124 parts of N-methylethanolamine were reacted to confirm that the epoxy value was 0, and the solid content was adjusted by adding ethylene glycol monobutyl ether, for pigment dispersion having a solid content of 60%. Resin No. Four solutions were obtained. This pigment dispersing resin No. The hydroxyl value of 4 was 150 mgKOH / g, the amine value was 90 mgKOH / g, and the number average molecular weight was 2,000.

Comparative Production Example 2 Pigment dispersion resin No. Production Example 5 In a flask equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 110 parts of nonylphenol and 960 parts of CNE195LB (Note 3) were charged and gradually heated with mixing and stirring, and reacted at 160 ° C. . Thereafter, 430 parts of ε-caprolactone is charged, and the temperature is raised to 170 ° C. for reaction. Further, 260 parts of diethanolamine and 124 parts of N-methylethanolamine were reacted to confirm that the epoxy value was 0, and the solid content was adjusted by adding ethylene glycol monobutyl ether, for pigment dispersion having a solid content of 60%. Resin No. Five solutions were obtained. This pigment dispersing resin No. The hydroxyl value of 5 was 250 mgKOH / g, the amine value was 120 mgKOH / g, and the number average molecular weight was 2,500.

  Table 1 shows the blending contents of Production Examples 1 to 3 and Comparative Production Examples 1 and 2.

Comparative Production Example 3 Pigment Dispersing Resin No. 6 Production Example To a flask equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 398 parts of ethylene glycol monobutyl ether, EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd., trade name, alicyclic epoxy having an epoxy equivalent of 180) Resin) 900 parts, diethanolamine 315 parts, amine compound (Note 4) 371 parts and epoxyamine product (Note 5) 1651 parts were charged, gradually heated with mixing and stirring, reacted at 150 ° C., epoxy equivalent 0 The solid content was adjusted by adding ethylene glycol monobutyl ether, and pigment dispersion resin No. 60 having a solid content of 60% was prepared. 6 solutions were obtained. This pigment dispersing resin No. The hydroxyl value of 6 was 180 mgKOH / g, the amine value was 96.5 mgKOH / g, and the number average molecular weight was 2,000.

(Note 4) Amine compound: 285 parts of stearic acid, 104 parts of hydroxylethylaminoethylamine and 80 parts of toluene were charged into a reaction vessel equipped with a thermometer, stirrer, reflux condenser and water separator, and gradually mixed and stirred. Heat, remove toluene as required, separate and remove 18 parts of the reaction water while raising the temperature, and then remove the remaining toluene under reduced pressure to obtain an amine compound having an amine value of 150 and a freezing point of 76 ° C. (Note 5) ) Epoxyamine product: In a flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 105 parts diethanolamine, 760 parts bisphenol A diglycidyl ether having an epoxy equivalent of 190, 456 parts bisphenol A and 330 parts ethylene glycol monobutyl ether And add epoxy at 150 ° C Epoxyamine product having a solid content of 80% obtained by reacting until the residual amount of the silyl group becomes zero. Comparative Production Example 4 Resin No. 4 for pigment dispersion 7 Production Example Epicoat 828EL (trade name, epoxy resin, manufactured by Japan Epoxy Resin Co., Ltd.) 1010 parts, 390 parts of bisphenol A, 240 parts of polycaprolactone diol (number average molecular weight about 1,200) and 0.2 parts of dimethylbenzylamine And is reacted at 130 ° C. until the epoxy equivalent is about 1,090. Next, 134 parts of dimethylethanolamine and 90 parts of acetic acid were added and reacted at 120 ° C. for 4 hours. Then, the solid content was adjusted by adding ethylene glycol monobutyl ether, and an ammonium salt type resin pigment having a solid content of 60%. Resin for dispersion No. 7 solutions were obtained. This pigment dispersing resin No. 7 had an ammonium salt value of 44 mg KOH / g and a number average molecular weight of 3,000.

Production Example 4 Pigment Dispersion Paste No. 4 1
8.3 parts of pigment dispersion resin with a solid content of 60% obtained in Production Example 1 (5 parts of solid content), 14 parts of JR-600E (Note 6), 11 parts of hydride PXN (Note 7), 1 part of bismuth hydroxide 1 part of dibutyltin oxide, 2.7 parts of 10% acetic acid (neutralizing agent) and 12 parts of deionized water were dispersed in a ball mill for 20 hours. 1 was obtained.

(Note 6) JR-600E: Product name, titanium white, manufactured by Teika Co., Ltd. (Note 7) Hydride PXN: Product name, aluminum silicate, manufactured by Georgia Kaolin Co., Ltd. Production Examples 5-12 Production Examples 2 to 9 Pigment dispersion paste No. In the same manner as in No. 1, the pigment dispersion paste no. 2-9 were created.

(Note 8) BF-20: manufactured by Sakai Chemical Industry Co., Ltd., trade name, barium sulfate (Note 9) Storage stability: 100 g of each pigment dispersion paste was put in a glass container and stored at 40 ° C. for 30 days. The state of the pigment dispersion paste was checked.

◎: Good with no problem ○: Slight pigment settling is observed, but returns to the state before storage with stirring for less than 10 minutes. Δ: Sedimentation of the pigment dispersion paste is observed, and stirring with less than 10 minutes returns to the state before storage. Even if it does not return or it becomes a paste state by stirring for 10 minutes or more, the aggregated state (dama) of the pigment remains. ×: The pigment is markedly settled, or even if it is stirred for 30 minutes or more, it remains in the paste state. Production Example 13 Amino group-containing epoxy resin No. 1
300 parts of ε-caprolactone is added to 400 parts of PP-400 (manufactured by Sanyo Chemical Co., Ltd., trade name, polypropylene glycol, number average molecular weight 400), and the temperature is raised to 130 ° C. Thereafter, 0.01 part of tetrabutoxy titanium is added and the temperature is raised to 170 ° C. Sampling was carried out over time while maintaining this temperature, the amount of unreacted ε-caprolactone was monitored by infrared absorption spectrum measurement, and when the reaction rate reached 98% or more, cooling was performed to obtain denaturant 2.

  Separately, 400 parts of bisphenol A and 0.2 part of dimethylbenzylamine were added to 1,000 parts of Epicoat 828EL (trade name, epoxy resin, epoxy equivalent 190, number average molecular weight 350, manufactured by Japan Epoxy Resin Co., Ltd.) at 130 ° C. The reaction is continued until the epoxy equivalent is 750. To this, 120 parts of nonylphenol was added and reacted at 130 ° C. until the epoxy equivalent reached 1,000. Next, 2200 parts of a modifying agent, 95 parts of diethanolamine and 65 parts of a diethylenetriamine ketimine compound were added, reacted at 120 ° C. for 4 hours, adjusted with ethylene glycol monobutyl ether, an amine value of 40 mg KOH / g, and a resin solid content of 80%. Polyol-modified amino group-containing epoxy resin No. added with nonylphenol 1 was obtained.

Production Example 14 Amino group-containing epoxy resin 2
A separable flask having an internal volume of 2 liters equipped with a thermometer, a reflux condenser and a stirrer was charged with 480 parts of 50% formalin, 110 parts of phenol, 202 parts of 98% industrial sulfuric acid and 424 parts of metaxylene at 84 to 88 ° C. React 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. 480 parts of a phenol-modified xylene formaldehyde resin having a viscosity of 1050 centipoise (25 ° C.) were obtained.

  To another flask, 1000 parts of Epicoat 828EL (trade name, epoxy resin, epoxy equivalent 190, molecular weight 350, manufactured by Japan Epoxy Resin Co., Ltd.), 400 parts of bisphenol A and 0.2 part of dimethylbenzylamine were added, and epoxy equivalent at 130 ° C. React until 750. Next, after adding 300 parts of xylene formaldehyde resin, 137 parts of diethanolamine and 95 parts of a ketimine product of diethylenetriamine and reacting at 120 ° C. for 4 hours, 403 parts of ethylene glycol monobutyl ether was added, and the amine value was 57 mg KOH / g resin solid content. An amino group-containing epoxy resin modified with xylene formaldehyde resin having a molecular weight of 2,000 and a solid content of 80%. 2 was obtained.

Production Example 15
In a reaction vessel, 270 parts of Cosmonate M-200 (Note 10) and 25 parts of methyl isobutyl ketone are added, and the temperature is raised to 70 ° C. To this, 15 parts of 2,2-dimethylolbutanoic acid was gradually added, and then 118 parts of ethylene glycol monobutyl ether was added dropwise, reacted at 70 ° C. for 1 hour, cooled to 60 ° C., and propylene glycol 152 Add parts. While maintaining this temperature, sampling was carried out over time, and it was confirmed by infrared absorption spectrum measurement that there was no absorption of unreacted isocyanato groups. 1 was obtained.

(Note 10) Cosmonate M-200: Trade name, manufactured by Mitsui Chemicals, Crude MDI
Production Example 17 Emulsion No. Production of 80% amino group-containing epoxy resin No. 1 obtained in Production Example 14 above. 1 was mixed with 87.5 parts (solid content 70 parts), the curing agent obtained in Production Example 16 was mixed with 33.3 parts (solid content 30 parts), and 10 parts formic acid 8.2 parts. , 183.5 parts of deionized water was added dropwise over about 15 minutes while stirring vigorously, and emulsion No. 3 with a solid content of 32.0% was obtained. 1 was obtained.

Production Example 18 Emulsion No. Production of 80% amino group-containing epoxy resin No. 1 obtained in Production Example 15 above. 2 was mixed with 87.5 parts (solid content 70 parts), the curing agent obtained in Production Example 16 was mixed with 33.3 parts (solid content 30 parts), and 10% formic acid 8.2 parts. , 183.5 parts of deionized water was added dropwise over about 15 minutes while stirring vigorously, and emulsion No. 33.0% solid content was obtained. 2 was obtained.

Example 1 Cationic Electrodeposition Paint No. Production of 32 No. 32 emulsion No. obtained in Production Example 17 No. 1 312.5 parts (solid content 100 parts), 50% pigment paste No. obtained in Production Example 4 No. 1 was added with 52 parts (26 parts) and 265.5 parts of deionized water. 1 was obtained.

Examples 2-6 Cationic electrodeposition paint No. Production Examples 2 to 6 Cationic electrodeposition paints No. 1 in the same manner as in Example 1 with the combinations shown in Table 3. 2-6 were created.

Comparative Examples 1-6 Cationic electrodeposition paint No. Production Examples 7 to 12 Cationic electrodeposition paints No. 1 in the same manner as in Example 1 with the combinations shown in Table 4. 7-12 were created.

Preparation of test plate Using each cationic electrodeposition paint obtained in the above examples and comparative examples, a cold-rolled steel plate (0.8 mm x 70 mm x 150 mm) subjected to zinc phosphate treatment has a dry film thickness of 20 µm. Thus, electrodeposition coating was applied at a bath temperature of 28 ° C., washed with water, baked at 170 ° C. for 20 minutes to prepare a test plate, and tested according to the following test method. The results are shown in Tables 5 and 6.

Secondary sagging resistance As shown in FIG. 1, two steel plates (1) and a steel plate (2) are rolled up together (the clearance between the steel plate (1) and the steel plate (2) is 100 μm) to produce a jig of 20 μm. Electrodeposition coating was performed under conditions where a dry coating film was obtained, washed with water, set for 10 minutes, then baked at 170 ° C. for 20 minutes, and the coated surface was observed for resistance to secondary sagging and peeling.

○: There is no problem with sagging / waxing △: Level that requires correction such as sharpening due to sagging / waxing X: Level with sagging / waxing that significantly impairs the appearance Suitability for electrodeposition coating of rust-proof steel sheets An electrodeposited paint is immersed in an alloyed hot-dip galvanized steel sheet (0.8 mm x 70 mm x 150 mm) that has been treated with zinc phosphate, and at a bath temperature of 28 ° C, 250 V for 3 minutes (30 seconds pressure increase + 2 minutes 30 seconds) (Constant voltage) The number of pinholes on the coated surface after electrodeposition coating, washing with water and baking and drying was counted.

○: No occurrence of pinholes △: 1-10 occurrences of pinholes X: More than 10 occurrences of pinholes Corrosion resistance Cross-cut scratches on the electrodeposition coating film with a knife so as to reach the base of the test plate Using this, a salt spray resistance test was conducted for 840 hours in accordance with JIS Z-2371. Evaluation was performed 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 2 mm (one side) from the cut part ○: The maximum width of rust and blisters is 2 mm or more and less than 3 mm (one side) from the cut part △: Maximum width of rust and blisters Is 3 mm or more and less than 4 mm (one side) from the cut part. ×: The maximum width of rust and blisters is 4 mm or more (one side) from the cut part. (Coating by Kansai Paint Co., Ltd., aqueous intermediate coating) was applied so that the cured film thickness was 25 μm, and then baked at 140 ° C. for 30 minutes with an electric hot air dryer. Furthermore, after applying neo-amylac 6000 (manufactured by Kansai Paint Co., Ltd., top coat) on the intermediate coating film by spray coating method so that the cured film thickness becomes 35 μm, it is 140 ° C. × 30 in an electric hot air dryer. An exposure test plate was prepared by baking for a minute. 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 horizontally in Chikura Town, Chiba Prefecture for one year, then rust and blister width from knife scratches. Based on the following criteria.

A: Maximum width of rust or swelling is less than 2 mm from the cut part (one side)
○: The maximum width of rust or blister is 2 mm or more and less than 3 mm from the cut part (one side)
Δ: The maximum width of rust or swelling is 3 mm or more and less than 4 mm from the cut part (one side)
X: The maximum width of rust or swelling is 4 mm or more (one side) from the cut part. 60 degree specular gloss The degree of gloss of the multilayer coating film is 60 degrees specular gloss of JIS K-5400 7.6 (1990). Accordingly, the reflectance was measured when the incident angle and the light receiving angle were 60 degrees, respectively, and expressed as a percentage when the glossiness of the reference surface of the specular glossiness was 100.

Paint stability (1)
Each cationic electrodeposition paint obtained in Examples and Comparative Examples was allowed to stand for 24 hours without stirring, and then stirred (700 rpm) for 3 hours, and then bent into an L shape (horizontal plane / vertical plane = 5 cm / 10 cm). Using a test plate, electrodeposition coating was performed under the conditions that a 20 μm dry coating film was obtained, washed with water, baked at 170 ° C. for 20 minutes, and the coating surface state of the L surface (horizontal surface) was checked.

◎: The L surface is good without any problem in finish. ○: Slight shine is observed on the L surface, but there is no problem as a product. △: Either L, dents or repellency is observed on the L surface. The surface of the surface is markedly rough, dents, or repellency. Paint stability (2)
Using 3 liters of each cationic electrodeposition paint obtained in Examples and Comparative Examples, a test was conducted so that the dry film thickness was 20 μm on a cold-rolled steel sheet (0.8 mm × 70 mm × 150 mm) subjected to zinc phosphate treatment. Each plate was subjected to electrodeposition coating, and then each emulsion and pigment paste were replenished so as to obtain a solid content before electrodeposition coating. On the next day, the same operation was repeated for 30 days (turnover test), and a change in “60 ° specular gloss” was observed.

A: Change in 60-degree specular gloss per month is less than 2 ○: Change in 60-degree specular gloss per month is 2 or more and less than 5 Δ: 1 month of 60-degree specular gloss Change between 5 and 10 or less x: change in 60 degree specular gloss per month exceeds 10

  Since the pigment dispersion paste of the present invention is excellent in storage stability, it is also advantageous during transportation in summer and overseas. By using this pigment dispersion paste, it is possible to supply an electrodeposition paint having excellent coating film performance and stability. is there.

It is the schematic of the panel for a secondary sagging resistance test.

Explanation of symbols

1 Cold-rolled steel sheet (1) subjected to chemical conversion treatment (0.8 mm x 70 mm x 150 mm)
2 Cold-rolled steel sheet with chemical conversion treatment (2) (0.8 mm x 50 mm x 50 mm)
3 Paint sauce water that exudes after the test

Claims (5)

  Glycidyl etherified product of novolak type phenol resin (a), cyclic ester compound (b), amine compound (c) and phenol compound (d) are combined into a total solid of (a), (b), (c) and (d) A pigment obtained by reacting at a ratio of (a) 30 to 70% by mass, (b) 5 to 45% by mass, (c) 5 to 15% by mass, and (d) 1 to 30% by mass based on the partial mass. A pigment dispersion paste comprising a dispersion resin (A) and a pigment component (B).   The mass ratio of the pigment dispersing resin (A) to the pigment component (B) is in the range of pigment dispersing resin (A) / pigment component (B) = 1 / 0.05 to 1/50. The pigment dispersion paste described in 1.   Cationic electrode comprising 0.1 to 50 parts by mass of the pigment-dispersed paste according to claim 1 or 2 based on the solid content with respect to 100 parts by mass of the solid content of the base resin and the curing agent of the cationic electrodeposition coating. Wearing paint.   The cation according to claim 3, comprising 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 2,500 as a base resin. Electrodeposition paint.   A coated article obtained by coating the cationic electrodeposition paint according to claim 3 or 4.

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