JP6207076B2 - Anion electrodeposition coating composition and coating film forming method - Google Patents

Description

  The present invention relates to an anionic electrodeposition coating composition and coating film forming method capable of forming a coating film having good coating stability and having excellent uniform film thickness, impact resistance, weather resistance and adhesion of top coating film. .

  Conventionally, anodized (anodized) aluminum material is lightweight and excellent in strength, corrosion resistance, etc. After molding, it is electrodeposited with an acrylic resin / melamine curable anion electrodeposition paint. The top coat film is applied as necessary, and it is used for aluminum sashes and the like.

  The above aluminum sashes may cause problems such as not only weather resistance but also peeling of the coating due to contact between aluminum sashes, peeling of the coating due to rail operation, etc. It was done.

  In addition, since many aluminum materials are subjected to anion electrodeposition at the same time, the film thickness may be uneven between aluminum members, or the film thickness of a specific part of the aluminum material may become unnecessarily thick (so-called uniform). Film thickness is insufficient).

  For example, Patent Document 1 discloses an anion containing a resin (A) containing a hydroxyl group and a carboxyl group, a blocked polyisocyanate compound (B), and polypropylene glycol for the purpose of improving weather resistance and adhesion of the top coat film. An electrodeposition paint is disclosed. However, with the above-mentioned anion electrodeposition coating, a coated article satisfying the uniform film thickness and the adhesion of the top coat film could not be obtained.

JP 2007-9059 A

  The problem to be solved by the present invention is to provide an anionic electrodeposition coating composition capable of providing a coated article having good coating stability and excellent uniform film thickness, impact resistance, weather resistance, and adhesion of a top coat film. To find.

  The present inventors have found that the above problems can be solved by an anionic electrodeposition coating composition containing a resin (A) containing a hydroxyl group and a carboxyl group, a crosslinking agent (B) and a specific polyether polyol (C). The present invention has been completed.

That is, the present invention relates to the following aspects.
“1. An anionic electrodeposition coating composition containing a resin (A) containing a hydroxyl group and a carboxyl group, a crosslinking agent (B) and a polyether polyol (C) represented by the following general formula (1), The polyether polyol (C) is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the solids of the resin (A) containing a hydroxyl group and a carboxyl group and the crosslinking agent (B). Anionic electrodeposition coating composition characterized by

Formula (1)
(In the formula (1), l, m and n are each independently an integer of 1 or more, and l + m + n = 3 to 15, and each A of ( OA ) _l , ( OA ) _m and ( OA ) _n Are the same or different ethylene groups and / or propylene groups)
2. The resin (A) containing a hydroxyl group and a carboxyl group contains 3 to 3 radical polymerizable unsaturated monomers represented by the following formula (2) based on the total amount of the radical polymerizable unsaturated monomers constituting the resin. The anion electrodeposition coating composition according to item 1, which is a resin containing 15% by mass,

Formula (2)
(In formula (2), R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ² represents a hydrogen atom or a methyl group)
3. The anionic electrodeposition coating composition according to item 1 or 2, wherein the crosslinking agent (B) is a melamine resin and / or a blocked isocyanate compound,
4). 0.05 to 10.0 parts by mass of epoxy phosphate ester compound (E) in solid content with respect to 100 parts by mass in total of solids of hydroxyl group and carboxyl group-containing resin (A) and crosslinking agent (B) The anion electrodeposition coating composition according to any one of items 1 to 3,
5. The anionic electrodeposition coating composition according to any one of items 1 to 4 is electrodeposited on an anodized aluminum substrate, and baked and cured to form an anion electrodeposition coating film having a dry film thickness of 3 to 9 μm. Coating film forming method,
6). The anionic electrodeposition coating composition according to any one of 1 to 4 is electrodeposited on an anodized aluminum base material to form an anionic electrodeposition coating film, and an overcoating coating is formed on the anionic electrodeposition coating film. Coating method, coating and drying by heating to form a multilayer coating film,
Coated article obtained by the coating film forming method according to 7.5 or 6. "

  The anion electrodeposition coating composition of the present invention is excellent in coating stability, and can be used in a coating line for a long period of time, and is excellent in uniform film thickness, impact resistance, weather resistance and adhesion of a top coating film. Coated articles can be provided.

  Specifically, by using the anion electrodeposition coating composition of the present invention, an aluminum material having a uniform film thickness can be obtained even when many objects are coated at the same time. Moreover, since the adhesion of the top coat film is excellent, it is possible to suppress the peeling of the top coat film due to contact between aluminum sashes or rail operation. Furthermore, even when exposed to sunlight at the window or the like, the coating film is hardly deteriorated and can provide an excellent design property over a long period of time.

It is a model figure of the jig | tool for a uniform film thickness test, and a wiring diagram.

  The present invention relates to an anionic electrodeposition coating composition containing a specific polyether polyol (C) with respect to a total solid content of 100 parts by mass of a resin (A) containing a hydroxyl group and a carboxyl group and a crosslinking agent (B). And a coating film forming method using the anion electrodeposition coating composition.

Resin (A) containing hydroxyl group and carboxyl group
The resin (A) containing a hydroxyl group and a carboxyl group is a resin having at least one carboxyl group in one molecule and at least one hydroxyl group in one molecule. Specific examples of the resin (A) containing a hydroxyl group and a carboxyl group include resins such as an acrylic resin, a polyester resin, a polyether resin, a polycarbonate resin, and a urethane resin. From the viewpoint of improving weather resistance, an acrylic resin is preferable. Is preferred.

  The acrylic resin comprises a carboxyl group-containing radical polymerizable unsaturated monomer (a1), a hydroxyl group-containing radical polymerizable unsaturated monomer (a2), and other radical polymerizable unsaturated monomers (a3 as required). )).

  Examples of the carboxyl group-containing radical polymerizable unsaturated monomer (a1) include monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.

  Examples of the hydroxyl group-containing radical polymerizable unsaturated monomer (a2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) ) Acrylate, and besides this, Plaxel FM1, Plaxel FM2, Plaxel FM3, Plaxel FA1, Plaxel FA2, Plaxel FA3 (above, Daicel Chemical Industries, trade name, caprolactone-modified (meth) acrylic acid hydroxy esters), etc. It is done.

  Examples of the other radical polymerizable unsaturated monomer (a3) include γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, and γ- (meth) acryloyloxy. Alkoxysilyl group-containing unsaturated monomers such as propyltriethoxysilane and vinyltrimethoxysilane; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate C1-C18 alkyl or cycloalkyl esters of (meth) acrylates such as octyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate, Aromatic vinyl monomers such as (meth) acrylic acid amide, N, N-dimethylol (meth) acrylamide, N, N-dimethoxymethyl (meth) acrylamide, N, N-di-n-butoxymethyl (meth) acrylamide, Examples include (meth) acrylamide monomers such as N-methoxymethyl-N-methylol (meth) acrylamide; and radical polymerizable unsaturated monomers represented by the following formula (2).

Formula (2)
(In Formula (2), R ¹ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R ² represents a hydrogen atom or a methyl group)
Examples of the radical polymerizable unsaturated monomer represented by the above formula (2) include N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N- Propoxymethyl (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N-hexoxymethyl (meth) acrylamide, N-isohexoxymethyl Mention may be made of (meth) acrylamide.

  The mixing ratio of these radically polymerizable unsaturated monomers is 1 to 20% by mass of the carboxyl group-containing polymerizable unsaturated monomer (a1) based on the total amount of the radically polymerizable unsaturated monomers to be constituted. 4 to 10% by mass, 1 to 40% by mass of the hydroxyl group-containing radically polymerizable unsaturated monomer (a2), preferably 5 to 30% by mass, and other radically polymerizable unsaturated monomers (a3) ) In the range of 40 to 98 mass%, preferably 60 to 91 mass%.

In particular, the radically polymerizable unsaturated monomer represented by the formula (2) is contained in an amount of 3 to 15% by mass, preferably 5 to 12% by mass, based on the total amount of the radically polymerizable unsaturated monomers to be constituted. Acrylic resin is preferable for improving impact resistance.
Resin (A) containing a hydroxyl group and a carboxyl group used in the anion electrodeposition coating composition of the present invention is the above carboxyl group-containing polymerizable unsaturated monomer (a1), hydroxyl group-containing radical polymerizable unsaturated monomer. Body (a2), if necessary, other radical polymerizable unsaturated monomer (a3), a polymerization initiator is added and mixed, and then, for example, about 50 ° C. in the presence of an inert gas such as nitrogen. In an organic solvent maintained at about 300 ° C., preferably about 60 ° C. to 250 ° C., for about 1 hour to about 24 hours, preferably about 2 hours to about 10 hours. It can be obtained by radical polymerization reaction for a time.

  Examples of the organic solvent used in the radical polymerization reaction include alcohols such as n-propanol, isopropanol, n-butanol, t-butyl alcohol, and isobutyl alcohol, ethylene glycol monobutyl ether, methyl carbitol, 2-methoxyethanol, 2-ethoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol Ethers such as propylene glycol monomethyl ether can be preferably used. In addition to this, if necessary, for example, aromatics such as xylene and toluene, acetone, methyl ethyl ketone, 2-pentanone, 2-hexanone, methyl isobutyl ketone, isophorone, cyclohexanone and other ketones, methyl acetate, acetic acid Esters such as ethyl, pentyl acetate, 3-methoxybutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl propionate, and ethyl propionate can be used in combination.

  Examples of the polymerization initiator used in the radical polymerization reaction include benzoyl peroxide, di-t-butyl hydroperoxide, t-butyl hydroperoxide, cumyl peroxide, cumene hydroperoxide, t-butyl peroxybenzoate, and lauryl peroxide. Examples thereof include oxide, acetyl peroxide, azobisdimethylvaleronitrile, and azobisisobutyronitrile.

The weight average molecular weight (Note 1) of the obtained resin (A) containing a hydroxyl group and a carboxyl group is preferably in the range of 5,000 to 100,000, particularly 20,000 to 50,000, and the acid value is 5 to 5. A range of 180 mg KOH / g, particularly 10 to 80 mg KOH / g, and a hydroxyl value of 3 to 150 mg KOH / g, particularly 10 to 80 mg KOH / g are suitable.
(Note 1) Weight average molecular weight: A value obtained by converting a weight average molecular weight measured using a gel permeation chromatograph (GPC) based on the molecular weight of standard polystyrene.
Specifically, “HLC8120GPC” (trade name, manufactured by Tosoh Corporation) is used as a gel permeation chromatograph, and “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL” are used as columns. ”And“ TSKgel G-2000HXL ”(trade names, all manufactured by Tosoh Corporation), and can be measured under the conditions of mobile phase tetrahydrofuran, measurement temperature 40 ° C., flow rate 1 mL / min, and detector RI. it can.

Cross-linking agent (B)
As the crosslinking agent (B) that can be used in the anion electrodeposition coating composition of the present invention, conventionally known compounds can be used, and examples thereof include melamine resins, benzoguanamine resins, urea resins, and blocked polyisocyanates. Can do. Among these crosslinking agents, melamine resins and blocked polyisocyanate compounds are preferred from the viewpoint of impact resistance and adhesion of the top coat film.

  Specific examples of melamine resins include fully alkyl methyl / butyl mixed etherified melamine resins, methylol group methyl / butyl mixed etherified melamine resins, imino methyl / butyl mixed etherified melamine resins, fully alkyl methylated melamine resins. And imino group-type methylated melamine resins.

  Examples of commercially available melamine resins include Cymel 232, Cymel 232S, Cymel 235, Cymel 236, Cymel 238, Cymel 266, Cymel 267, Cymel 285, and other fully alkyl methyl / butyl mixed etherified melamine resins; Cymel 272, etc. Methylol-based methyl / butyl mixed etherified melamine resins; Cymel 202, Cymel 207, Cymel 212, Cymel 253, Cymel 254 and other imino methyl / butyl mixed etherified melamine resins; Cymel 300, Cymel 301, Cymel 303, Cymel Fully alkyl type methylated melamine resin such as 350; Cymel 325, Cymel 327, Cymel 703, Cymel 712, Cymel 254, Cymel 253, Cymel 212, Cymel 1 Imino group type methylated melamine resin, such as 28 (manufactured by Nihon Cytec Industries Inc.), U-VAN 20SE60 (Mitsui Cytec Co., Ltd., butyl etherified melamine resins), and the like.

  The polyisocyanate compound in the blocked polyisocyanate compound is a compound having two or more free isocyanate groups in one molecule, and examples thereof include aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate; Alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate, cyclohexylene diisocyanate, methylenebis (cyclohexyl isocyanate), isophorone diisocyanate; tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate , Aromatic diisocyanates such as naphthalene diisocyanate 2-isocyanatoethyl-2,6-diisocyanatocaproate, 3-isocyanatomethyl-1,6-hexamethylene diisocyanate, 4-isocyanatomethyl-1,8-octamethylene diisocyanate (commonly called triisocyanate) And trivalent or higher organic polyisocyanate compounds such as aminononane triisocyanate). Examples thereof include cyclized polymers or burettes of these polyisocyanate compounds; or combinations thereof.

  On the other hand, as a blocking agent for blocking a polyisocyanate compound, oxime compounds such as methyl ethyl ketoxime, methyl amyl ketoxime and cyclohexanone oxime; phenol compounds such as phenol, para-t-butylphenol and cresol; n-butanol, 2- Aliphatic alcohols such as ethyl hexanol; 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; ε-caprolactam, γ-butyrolactam, etc. And lactam compounds.

  Commercially available products of the above blocked polyisocyanate compounds include, for example, Barnock D-750, Barnock D-800, Barnock DN-950, Barnock DN-970 or Barnock DN-15-455 (manufactured by Dainippon Ink & Chemicals, Inc.). ), Death Module L, Death Module N, Death Module HL, Death Module IL or Death Module N3390 (above, manufactured by Bayer Products), Takenate D-102, Takenate D-202, Takenate D-110N or Takenate D-123N (Takeda Pharmaceutical Co., Ltd., trade name), Coronate L, Coronate HL, Coronate EH or Coronate 203 (Nippon Polyurethane Industry Co., Ltd., trade name), Duranate 24A-90CX (Asahi Kasei Kogyo Co., Ltd., trade name) Mentioned That.

  The mixing ratio of the hydroxyl group and carboxyl group-containing resin (A) and the crosslinking agent (B) in the anionic electrodeposition coating composition is the solid content of the hydroxyl group and carboxyl group-containing resin (A) and the crosslinking agent (B). Based on a total of 100 parts by mass, the resin (A) containing a hydroxyl group and a carboxyl group is 50 to 90 parts by mass, preferably 60 to 75 parts by mass, and the crosslinking agent (B) is 10 to 50 parts by mass, preferably 25 to 40 parts. The inclusion of a mass part is preferable from the viewpoint of uniform film thickness and impact resistance.

Polyether polyol (C)
The anion electrodeposition coating composition of the present invention contains a polyether polyol (C) represented by the following general formula (1).

Formula (1)
(In the formula (1), l, m and n are each independently an integer of 1 or more, and l + m + n = 3 to 15, and each A of ( OA ) _l , ( OA ) _m and ( OA ) _n Are the same or different ethylene groups and / or propylene groups)
Commercially available products can be used as the polyether polyol (C), for example, Sanniks GP-250, Sanniks GP-400, Sanniks GP-600, Sanniks GP-1000 (above, manufactured by Sanyo Chemical Co., Ltd., Product Name), Leocon GP-250, Leocon GP-300, Leocon GP-400, Leocon GP-700 (above, manufactured by Lion Corporation), Polypropylene triol glycol triol type (above, manufactured by Wako Pure Chemical Industries, Ltd.) ).

  The blending ratio of the polyether polyol (C) in the anion electrodeposition coating composition is based on the total solid content of 100 parts by mass of the resin (A) containing a hydroxyl group and a carboxyl group and the crosslinking agent (B). It contains 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, and more preferably 1 to 6 parts by weight of the polyol (C) as a solid component, and thus the coating stability, uniform film thickness, and top coat film are contained. It is preferable from the viewpoint of improving the adhesion of the resin.

Triazine UV absorber (D)
The anion electrodeposition coating composition of the present invention can contain a triazine-based ultraviolet absorber (D) as necessary. The triazine-based ultraviolet absorber (D) can improve the weather resistance without deteriorating the adhesion of the top coat film.

  Examples of the triazine-based ultraviolet absorber (D) include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5 [(hexyl) oxy] -phenol (Ciba Specialty). • Chemicals, trade name, Tinuvin 577FF), 2- [4- [6 (2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethyl) Phenyl) -1,3,5-triazine and 2- [4- [6 (2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) ) -1,3,5-triazine mixture (trade name, Tinuvin 400, manufactured by Ciba Specialty Chemicals), 2,4-bis (2,4-dimethylphenyl) -6- (2 Hydroxy-4-iso-octyloxyphenyl) -s-triazine (trade name, Tinuvin 411L, manufactured by Ciba Specialty Chemicals) 2,4-bis (2,4-dimethylphenyl) -6- (2-hydroxy- 4-octyloxyphenyl) -1,3,5-triazine (Mitsui Cytec Co., Ltd., trade name, CYAGARD UV1164L) and the like.

When blending a triazine-based ultraviolet absorber (D) in the anionic electrodeposition coating composition,
The blending ratio is 0. 0 in terms of the solid content of the triazine-based ultraviolet absorber (D) based on 100 parts by mass of the total solid content of the hydroxyl group- and carboxyl group-containing resin (A) and the crosslinking agent (B). It is 1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, and more preferably 0.8 to 3 parts by mass from the viewpoint of improving paint stability and weather resistance.

Epoxy phosphate compound (E)
The anion electrodeposition coating composition of the present invention can contain an epoxy phosphate ester compound obtained by adding a phosphate compound to an epoxy resin, if necessary.
Examples of the epoxy resin include bisphenol-type epoxy resins, novolac-type epoxy resins, and modified epoxy resins obtained by reacting an epoxy group or a hydroxyl group in these epoxy resins with a modifier.

The bisphenol-type epoxy resin is, for example, a resin produced by condensing epichlorohydrin and bisphenol to a high molecular weight in the presence of a catalyst such as an alkali catalyst, if desired, and epichlorohydrin and bisphenol, if desired, such as an alkali catalyst. It can be a resin obtained by condensing in the presence of a catalyst and synthesizing with a low molecular weight epoxy resin, and then polyadding the low molecular weight epoxy resin and bisphenol. The epoxy equivalent of the epoxy resin is preferably 172 to 4,000, more preferably 175 to 1,000.
Examples of the bisphenol include bis (4-hydroxyphenyl) methane [bisphenol F], 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], 2,2-bis (4-hydroxyphenyl) butane [bisphenol B], bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-tert-butyl-phenyl) -2,2-propane, Examples thereof include p- (4-hydroxyphenyl) phenol, oxybis (4-hydroxyphenyl), sulfonylbis (4-hydroxyphenyl), 4,4′-dihydroxybenzophenone, and bis (2-hydroxynaphthyl) methane. The above bisphenols can be used alone or as a mixture of two or more.
Examples of the novolak type epoxy resin include a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, and a phenol glyoxal type epoxy resin having a plurality of epoxy groups in the molecule. Examples of the phosphoric acid compound include orthophosphoric acid and pyrophosphoric acid.
In addition, as a commercial item of an epoxyphosphate ester compound, XU-8096.007, XU-71899.00, XQ-82908.00, XQ-82919.00, DER620-PP50, DER621-EB50, DER621-PP50 ( As mentioned above, Dow Chemical Japan Co., Ltd. product name), Epototo ZX1300, ZX1300-1 (above, Toto Kasei Co., Ltd. product name) and the like can be mentioned.

  When the epoxy phosphate ester compound (E) is blended in the anionic electrodeposition coating composition, the blending ratio is 100 parts by mass in total of the solid content of the hydroxyl group and carboxyl group-containing resin (A) and the crosslinking agent (B). Based on the above, 0.05 to 10.0 parts by mass, preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass in terms of the solid content of the epoxyphosphate compound (E) It is preferable to be within the range of from the viewpoint of improving the coating stability, impact resistance, and adhesion of the top coat film.

  Moreover, the anion electrodeposition coating composition of this invention can contain a curing catalyst, a basic compound, surfactant, a hindered amine light stabilizer, etc. as needed. Examples of the curing catalyst include n-butylbenzenesulfonic acid, n-amylbenzenesulfonic acid, n-octylbenzenesulfonic acid, n-dodecylbenzenesulfonic acid, n-octadecylbenzenesulfonic acid, n-dibutylbenzenesulfonic acid, i-propylnaphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, etc., and amine neutralized products of these sulfonic acids, etc .; dioctyltin dilaurate, dioctyltin dibenzoate, dibutyltin dibenzoate Liquid tin compounds such as;

  When a curing catalyst is blended in the anionic electrodeposition coating composition, the blending ratio is based on the total solid content of 100 parts by mass of the resin (A) and the crosslinking agent (B) containing a hydroxyl group and a carboxyl group. It is in the range of 0.05 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass in terms of solid content of the catalyst, in terms of improving paint stability and weather resistance. Desirable from.

The basic compound is contained to neutralize the carboxyl-containing resin (A) and / or adjust the pH of the anion electrodeposition coating bath. Specifically, primary monoamines such as ethylamine, propylamine, butylamine, benzylamine, monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol; diethylamine, diethanolamine, di-n- or di- -Secondary amines such as iso-propanolamine, N-methylethanolamine, N-ethylethanolamine; tertiary monoamines such as dimethylethanolamine, trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine, dimethylaminoethanol; diethylenetriamine And polyamines such as hydroxyethylaminoethylamine, ethylaminoethylamine, and methylaminopropylamine. The blending ratio of the basic compound is 0.1 to 1.2 equivalents, preferably 0.2 to 0.8 equivalents as a neutralization equivalent.
As the surfactant, any nonionic surfactant or anionic surfactant can be used as long as it has a surface wetting action, but a nonionic surfactant that has little influence on a metal material or the like is preferable.

  Examples of nonionic surfactants include polyoxyethylene tridecyl ether surfactants, polyoxyalkylene tridecyl ether surfactants, polyoxyalkylene alkyl ether surfactants, and polyoxyethylene styrenation agents. Examples include phenyl ether.

In addition, as a commercial item of surfactant, Neugen TDS-30, Neugen TDS-50,
Polyoxyethylene tridecyl ether surfactants such as Neugen TDS-70 and Neugen TDS-80; Neugen XL-40, Neugen XL-50, Neugen XL-60, Neugen XL-70, Neugen TDX-50, Neugen TDX Polyoxyalkylene tridecyl ethers such as -80D; polyoxyalkylene alkyl ethers such as Neugen LF-60X and Neugen LF-100X; polyoxyethylene styrenated phenyls such as Neugen EA-87, Neugen EA-137 and Neugen EA-157 Ether (above, Daiichi Kogyo Seiyaku); Polyoxyalkylene alkyl ether surfactants such as New Coal 2303Y and New Coal 2306H; Polys such as New Coal NT-3, New Coal NT-5 and New Coal NT-7 Xylene alkylene alkyl ether surfactant (or, Nippon Emulsifier Co., Ltd., trade name) and the like.

  Further, polyether-modified siloxane surfactants can also be suitably used. Examples of the trade name of the polyether-modified siloxane surfactant include BYK-307, BYK-345, BYK-346, BYK-348, BYK-3455 and the like manufactured by Big Chemie. Among the above surfactants, polyoxyethylene tridecyl ether surfactants are preferable from the viewpoint of improving the uniform film thickness.

  When the surfactant is blended in the anionic electrodeposition coating composition of the present invention, the blending ratio is based on 100 parts by mass of the total solid content of the hydroxyl group and carboxyl group-containing resin (A) and the crosslinking agent (B). It is preferable that the surfactant is in the range of 0.1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, more preferably 1.0 to 5.0 parts by mass in terms of solid content. Desirable for sex.

The light stabilizer is preferably a hindered amine derivative. Specifically, bis- (2,2 ′, 6,6′-tetramethyl-4-piperidinyl) sebate, 4-benzoyloxy-2,2 ', 6,6'-tetramethylpiperidine and the like can be mentioned, and one or more of these can be appropriately selected and used. Specific examples of commercially available products include Tinuvin 123, Tinuvin 144, Tinuvin 152, Tinuvin 292, Tinuvin 5100, Tinuvin 765, Tinuvin 770, (manufactured by Ciba Japan), Sanol LS292, Sanol LS440, Sanol LS744, Sanol LS2626. , Sanol LS944 (manufactured by Sankyo Lifetech Co., Ltd.), Hostavin N20, Hostabin N24, Hostabin N30, Hostabin N321, Hostabin PR31, Hostabin 3050, Hostabin 3051, Hostabin 3052, Hostabin 3053, Hostabin 3058, Hostabin Examples include, but are not limited to, 3063, hostabin 3212 (manufactured by Clariant Japan). These light stabilizers may be used alone or in combination of two or more.
When the light stabilizer is blended in the anion electrodeposition coating composition of the present invention, the blending ratio is 100 parts by mass with respect to the total solid content of the resin (A) containing a hydroxyl group and a carboxyl group and the crosslinking agent (B). In addition, the light stabilizer is in the range of 0.1 to 10 parts by mass, preferably 0.2 to 5.0 parts by mass, more preferably 0.3 to 1.0 parts by mass in terms of solid content. Desirable to improve stability and weather resistance.

  The anion electrodeposition coating composition of the present invention comprises a hydroxyl group- and carboxyl group-containing resin (A), a crosslinking agent (B), a polyether polyol (C), and, if necessary, a triazine-based ultraviolet absorber (D). , Epoxy phosphate ester compound (E), curing catalyst, basic compound, surfactant, light stabilizer and the like are mixed and diluted with deionized water or the like to obtain a solid content concentration of about 5 to 40% by mass, preferably It can be obtained by adjusting the pH to 10 to 25% by mass and adjusting the pH to 7.0 to 10.0, preferably 7.5 to 9.5.

Coating Film Forming Method A coating film forming method using the anion electrodeposition coating composition of the present invention is usually adjusted to a bath temperature of 15 to 35 ° C. and a load voltage of 100 to 400 V using the coating composition as a bath. In the bath, after anionic electrodeposition coating with an object to be coated such as aluminum or aluminum alloy as an anode, without washing with water (non-rinsing) or with water (rinsing), then setting at room temperature, then about 130 The anion electrodeposition coating film is obtained by heating and drying at -200 ° C, preferably 140-160 ° C for about 15-50 minutes, preferably 15-30 minutes. The dry film thickness of the anion electrodeposition coating film is about 30 μm or less, preferably 1 to 12 μm, more preferably 3 to 9 μm.

  Furthermore, a top coat can be applied on the anion electrodeposition coating film of the present invention, if necessary. As the top coating material, a coating material which is known per se and mainly contains a base resin and a curing agent can be used. Also, after washing the anion electrodeposition coating film with water and setting it at room temperature, the top coating was applied to the uncured anion electrodeposition coating film without baking and curing, and both coating films were baked and cured simultaneously to form a multilayer. A coating film can also be obtained (so-called two-coat one-bake coating).

Examples of the base resin for the top coating include acrylic resins, polyester resins, alkyd resins, epoxy resins, urethane resins, silicone resins, fluorine resins and modified products thereof, amino resins, ( Blocked) A top coating composition containing a cured product such as a polyisocyanate compound can be used. The top coating material may be any of an organic solution-type paint using an organic solvent as a medium, a non-aqueous dispersion paint, a water-soluble and / or emulsion paint and a powder paint using water as a medium.
The top coating film is applied to the anion electrodeposition coating film by a usual coating means such as brush coating, spray coating, dip coating, flow coating, roller coating, electrostatic spray coating, and then dried (including heating). ) To obtain. The film thickness of the top coat film varies depending on required performance and the like, but is usually in the range of about 10 to 100 μm, preferably 15 to 40 μm in terms of dry film thickness. In addition, drying can be performed under appropriate conditions depending on room temperature or heating.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In the following description, “part by mass” is abbreviated as “part”, and “mass%” is abbreviated as “%”.

Production Example 1 Acrylic resin solution No. 1 1) 16.7 parts of isopropyl alcohol and 13.3 parts of propylene glycol monomethyl ether were placed in a reaction vessel and maintained at 80 ° C., and the following “mixture (1)” was added dropwise over 4 hours, followed by azobis 0.5 parts of dimethylvaleronitrile was added, the reaction was carried out by maintaining at 80 ° C. for 3 hours, and further adjusted with propylene glycol monomethyl ether to prepare an acrylic resin solution no. 1 was obtained. Acrylic resin solution No. The resin solid content of No. 1 was an acid value of 43 mgKOH / g, a hydroxyl value of 63 mgKOH / g, and a weight average molecular weight of about 30,000.
“Mixture (1)”
Acrylic acid 5.5 parts Styrene 5 parts Methyl methacrylate 45 parts n-Butyl acrylate 20 parts 2-Hydroxyethyl acrylate 13 parts KBM-503 (Note 2) 2 parts Cyclohexyl methacrylate 9.5 parts Azobisdimethylvaleronitrile 1.5 Part
(Note 2) KBM-503: trade name, γ-methacryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

Production Example 2 Acrylic resin solution No. The following “mixture (2)” was added dropwise over a period of 4 hours to 16.7 parts of isopropyl alcohol and 13.3 parts of propylene glycol monomethyl ether, which were kept at 80 ° C. over 4 hours, and then azobis 0.5 parts of dimethylvaleronitrile was added, the reaction was carried out by maintaining at 80 ° C. for 3 hours, and further adjusted with propylene glycol monomethyl ether to prepare an acrylic resin solution no. 2 was obtained.
Acrylic resin solution No. The resin solid content of No. 2 was an acid value of 43 mgKOH / g, a hydroxyl value of 63 mgKOH / g, and a weight average molecular weight of about 31,000.
"Mixture (2)"
Acrylic acid 5.5 parts Styrene 5 parts Methyl methacrylate 40 parts n-Butyl acrylate 15 parts 2-hydroxyethyl acrylate 13 parts KBM-503 (Note 2) 2 parts N-butoxymethyl acrylamide 10 parts Cyclohexyl methacrylate 9.5 parts Azobis 1.5 parts of dimethylvaleronitrile.

Example 1 Anionic electrodeposition paint No. 1 Production Example 1 Acrylic resin solution No. 1 obtained in Production Example 1 1 60 parts (solid content), Cymel 235 (note 3) 40 parts (solid content), Sanniks GP-250 (note 5) 3 parts (solid content), dinonylnaphthalenesulfonic acid 0.1 part (solid content) ), Triethylamine (0.4 equivalent neutralized amount) as a neutralizing agent was added and mixed and dispersed, then deionized water was gradually added dropwise with stirring, and triethylamine was further added so that the pH was 8.2. Anion electrodeposition paint No. 10 having a solid content of 10% adjusted with deionized water. 1 was obtained.

Examples 2 to 18 and Comparative Examples 1 to 12 2-No. 30 Production Example In the same manner as in Example 1, the anionic electrodeposition paint No. 1 having a solid content of 10% with the formulation shown in Tables 1 and 2 was used. 2-No. 30 was obtained.

(Note 3) Cymel 235: Nippon Cytec Industries, Ltd., trade name, methyl-butyl mixed etherified melamine resin (Note 4) Duranate 24A-90CX: Asahi Kasei Kogyo Co., Ltd., trade name, block polyisocyanate, solid content 80 %
(Note 5) Sanniks GP-250: Sanyo Chemical Industries, trade name, polyether polyol (C), number average molecular weight 250
(Note 6) Sanniks GP-400: Sanyo Chemical Industries, trade name, polyether polyol (C), number average molecular weight 400
(Note 7) Sanniks GP-1000: Sanyo Chemical Industries, trade name, polyether polyol (C), number average molecular weight 1000
(Note 8) Sannics PP-1000: Sanyo Chemical Industries, trade name, polypropylene glycol, number average molecular weight 1,000
(Note 9) Tinuvin 400: Ciba Specialty Chemicals, trade name, triazine UV absorber (Note 10) Tinuvin 577FF: Ciba Specialty Chemicals, trade name, triazine UV absorber
(Note 11) Tinuvin 384: Ciba Specialty Chemicals, trade name, benzotriazole UV absorber
(Note 12) Uvinal 3050: manufactured by BASF Japan, trade name, benzophenone ultraviolet absorber (Note 13) XQ-82908.00: manufactured by Dow Chemical Japan, trade name, epoxy phosphate ester compound (Note 14) Epototo ZX1300: Product name, Epoxyphosphate ester compound (Note 15) Neugen TDS-50: Product name, polyoxyethylene tridecyl ether surfactant (Note 16) BYK-348 : Product name, polyether-modified siloxane fluorine-containing surfactant, manufactured by Big Chemie.

(Note 17) Paint stability:
The paint was filled in a test tube (height 20 cm, capacity 20 ml) and allowed to stand at 30 ° C. for 7 days, and then the state of the paint composition was examined.
The symbol ◎ indicates a good state without sedimentation of the coating composition.
○, although the sedimentation of the coating composition is slight, it returns to the original state by simple stirring.
In x, sedimentation of the coating composition is observed, and the original state is not restored.

Preparation of test plate Secondary electrolytic treatment (degreasing-etching-neutralization-anodizing treatment-sealing) was performed in the baths of the anion electrodeposition coating composition obtained in Examples and Comparative Examples. An anodized aluminum material (70 mm × 150 mm × 0.5 mm) having a treatment film thickness of about 10 μm is dipped, electrodeposition is applied so that the dry coating thickness is 8 μm, washed with water, and then at 180 ° C. for 20 minutes. A test plate was obtained by baking. Tables 1 and 2 also show the results of testing using each test plate according to the test conditions described below.

(Note 18) Uniform film thickness:
As shown in FIG. 1, using a jig for a uniform film thickness test in which five aluminum materials (70 mm × 150 mm × 0.5 mm) are suspended at intervals of 1 cm, a coating bath temperature of 21 ° C., an aluminum material and an electrode The electrodeposition coating was carried out at a voltage of 8 μm on the outer plate, with a distance between the electrodes of 10 cm and an energization time of 3 minutes. The uniform film thickness was evaluated by “(dry coating film mass of fifth aluminum plate / dry coating film thickness of first aluminum plate) × 100 (%)”.
◎: (Dry coating mass of the fifth aluminum plate / Dry coating mass of the first aluminum plate) × 100 = over 80% ○: (Dry coating mass of the fifth aluminum plate) / Dry coating mass of first aluminum plate) × 100 = 70% or more and less than 80% Δ is (dry coating mass of fifth aluminum plate / first aluminum plate mass) Dry coating mass) × 100 = 60% or more and less than 70%. X is (dry coating mass of fifth aluminum plate / dry coating mass of first aluminum plate) × 100 = Less than 60%.

(Note 19) Impact resistance:
After each test plate is placed in a constant temperature and humidity chamber at a temperature of 20 ° C. ± 1 and a humidity of 75 ± 2% for 24 hours, the size specified in the DuPont impact tester specified in JIS K 5600-5-3 (1999) is obtained. A striker was attached to the cradle and the test plate was sandwiched between them. Next, a weight of 500 g was dropped on the striker (1/2 inch), and the drop height (cm) at which cracks or peeling occurred on the coating film (front surface) due to the impact was measured. It was evaluated according to criteria.
◎ is a drop height at which cracks and peels occur, is over 50 cm. ○ is a drop height at which cracks and peels are generated is more than 40 cm and less than 50 cm. Δ is a drop height at which cracks and peels are generated. More than 30 cm and not more than 40 cm ×: the height of falling where cracks or peeling occurs is 30 cm or less.

(Note 20) Weather resistance:
By the accelerated weather resistance test based on JIS K5600-7-8 (1999), the time required for the gloss retention of the coating film after the test to divide 75% relative to the gloss of the coating film before the test was measured.
The symbol ◎ indicates that the gloss retention time is less than 3,000 hours when the gloss retention rate is less than 75%. The symbol ◯ indicates that the time when the gloss retention rate is less than 75% is 2,500 hours or more and less than 3,000 hours. Is less than 2,500 hours and less than 2,500 hours
X: Time for gloss retention to be less than 75% is less than 2,000 hours.

(Note 21) Adhesion of top coat film:
Fukkalon (trade name, fluorine-based baking curable paint) manufactured by Kansai Paint Co., Ltd. was applied to the test plate to a film thickness of 30 μm and dried at 215 ° C. for 20 minutes. Then, after being immersed in boiling water for 4 hours, it was taken out and left at room temperature for 1 hour.
The test plate was cut into a grid pattern at intervals of 1 mm with a cutter knife, and Cellotape (registered trademark) was applied to and peeled from the 100 squares.
◎ indicates that there is no problem with the remaining squares (pieces) / total squares (pieces) = 100/100
○ indicates that the remaining squares (pieces) / total squares (pieces) = 95 to 99/100, and there is no problem in use in the product.
Δ is a residual cell (pieces) / total cell (pieces) = 90 to 94/100, and there is a problem in using the overcoated product. ×: remaining cell (pieces) / total cell ( Pieces) = 89 or less / 100, it is difficult to use products with overcoating.

  With the anion electrodeposition coating composition of the present invention, a coated article having excellent uniform film thickness, impact resistance, top coat adhesion, and weather resistance can be obtained.

1. The 1st aluminum plate in the jig | tool for a uniform film thickness test is shown.
2. The 5th aluminum plate in the jig | tool for a uniform film thickness test is shown.
3. 3. Anion electrodeposition paint bath Distance between electrodes 10cm

Claims (7)

An anionic electrodeposition coating composition containing a hydroxyl group and carboxyl group-containing resin (A), a crosslinking agent (B) and a polyether polyol (C) represented by the following general formula (1), wherein the hydroxyl group and carboxyl The polyether polyol (C) is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the solids of the group-containing resin (A) and the crosslinking agent (B). Anion electrodeposition coating composition.

Formula (1)
(In the formula (1), l, m and n are each independently an integer of 1 or more, and l + m + n = 3 to 15, and each A of ( OA ) _l , ( OA ) _m and ( OA ) _n Are the same or different ethylene groups and / or propylene groups) The resin (A) containing a hydroxyl group and a carboxyl group contains 3 to 3 radical polymerizable unsaturated monomers represented by the following formula (2) based on the total amount of the radical polymerizable unsaturated monomers constituting the resin. The anionic electrodeposition coating composition according to claim 1, which is a resin containing 15% by mass.

Formula (2)
(In formula (2), R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ² represents a hydrogen atom or a methyl group) The anionic electrodeposition coating composition according to claim 1 or 2, wherein the crosslinking agent (B) is a melamine resin and / or a blocked isocyanate compound. 0.05 to 10.0 parts by mass of epoxy phosphate ester compound (E) in solid content with respect to 100 parts by mass in total of solids of hydroxyl group and carboxyl group-containing resin (A) and crosslinking agent (B) The anion electrodeposition coating composition as described in any one of Claims 1-3 contained. The anionic electrodeposition coating composition according to any one of claims 1 to 4 is electrodeposited on an anodized aluminum substrate, and baked and cured to form an anionic electrodeposition coating film having a dry film thickness of 3 to 9 µm. Coating film forming method. The anionic electrodeposition coating composition according to any one of claims 1 to 4 is electrodeposited on an anodized aluminum base material to form an anionic electrodeposition coating film, and an overcoating is applied on the anion electrodeposition coating film. A coating film forming method in which a paint is applied and dried by heating to form a multilayer coating film. The coated article obtained by the coating-film formation method of Claim 5 or 6.

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