JP2006152056A - Water-based paint and painted article coated with the water-based paint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based paint generating little formaldehyde and blocking agent (volatile organic compound) from the coating film in baking. <P>SOLUTION: The water-based paint comprises (A) a resin component produced by the radical polymerization of a mixture of (a) 0.1-30 wt.% nitrogen-containing radically polymerizable unsaturated monomer expressed by formula (1) (R is H or CH<SB>3</SB>; R<SP>1</SP>is C<SB>2</SB>H<SB>2n</SB>OH; R<SP>2</SP>is H, a 1-6C alkyl or C<SB>m</SB>H<SB>2m</SB>OH; and m and n are each an integer of 2-6), (b) 1-20 wt.% carboxyl-containing radically polymerizable unsaturated monomer and (c) 50-98.9 wt.% other radically polymerizable unsaturated monomer, and (C) 0.01-10 pts.wt. (based on 100 pts.wt. of the solid component of the resin component A) of an organic acid catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-based paint that generates less formaldehyde and a blocking agent (volatile organic compound) from a coating film during baking, and a coated article formed by coating the water-based paint.

Conventional paints mainly use paints that use organic solvents. However, when organic solvents are used, there is always a risk of fire, and the impact on the health of the user has increased. The impact is concerned. Furthermore, the use of organic solvents has been limited by low VOC (volatile organic compounds) and HAPs (hazardous air pollutants) regulations. From such a background, water-based paints have been made water-based, and water-based paints for various objects to be coated have been developed. Among these, electrodeposition coating using an electrodeposition paint is excellent from the viewpoint of uniformity of coating film quality, high coating efficiency, and labor saving.
As an object to be coated, aluminum has been increasingly used as a material related to building materials, taking advantage of its properties such as light weight, easy processing, and excellent corrosion resistance. In general, aluminum molds themselves are inferior in corrosion resistance, wear resistance, chemical resistance, etc., so after anodizing the aluminum, the purpose of obtaining a glossy paint film and the die marks generated during extrusion are conspicuous. In order to make it difficult, electrodeposition coating is generally performed using anionic electrodeposition paint among water-based paints.
Conventionally, as an invention relating to an anion electrodeposition coating material, a matte coating material in which two kinds of acrylic resins having different solubility parameters (SP values) and a melamine resin that is incompatible with these acrylic resins is dispersed in water. [Patent Document 1] has been developed.
In addition, there is a method of containing a water-dispersible resin and a melamine resin, and obtaining a matte coating film by the difference in solubility parameter (SP value) of the water-dispersible resin [Patent Document 2].
Moreover, there is a method of using an emulsion obtained by radical polymerization reaction of a radically polymerizable unsaturated monomer and a melamine resin and / or a blocked isocyanate compound as a cross-linking agent [Patent Document 3].
In addition, a compound having two or more polymerizable unsaturated groups in one molecule, a hydroxyl group-containing polymerizable unsaturated monomer, a carboxyl group-containing polymerizable unsaturated monomer, and other polymerizable unsaturated monomers There is an invention in which the finished gloss can be easily adjusted with an anionic electrodeposition paint containing an acrylic resin obtained by copolymerization and a melamine resin and / or a blocked isocyanate as a crosslinking agent [Patent Document 4].
As described above, conventional anionic electrodeposition paints use melamine resin or blocked isocyanate as a cross-linking component, and formaldehyde and blocking agents (volatile organic compounds) are often generated. There was a need for improvement.
Japanese Patent Laid-Open No. 10-46065 JP 2001-131494 A JP 2003-292879 A JP 2003-49112 A

  The problem to be solved is to find a water-based paint that generates less formaldehyde and blocking agents (volatile organic compounds) from the coating film during baking.

 As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have a specific amount containing a specific nitrogen-containing radical polymerizable unsaturated monomer and a carboxyl group-containing radical polymerizable unsaturated monomer. Water-based paint (I) containing a resin component obtained by radical polymerization reaction of the body and an organic acid catalyst, and an aqueous paint containing at least two kinds of resin components and an organic acid catalyst with adjusted solubility parameters (SP value) We have found that this can be achieved by (II) and have completed the invention.

  The aqueous paint of the present invention reduces the emission of formaldehyde and blocking agents (volatile organic compounds) from the paint film during baking, and is excellent in curability, paint film performance, and paint stability.

The water-based paint of the present invention is (1). Obtained by radical polymerization reaction of a radical polymerizable unsaturated monomer including a specific nitrogen-containing radical polymerizable unsaturated monomer (a) and a carboxyl group-containing radical polymerizable unsaturated monomer (b) Water-based paint (I) containing 0.01 to 10 parts by weight of the organic acid catalyst (C) with respect to 100 parts by weight of the solid content of the resin component (A) and the resin component (A).
(2). A resin component (B ₁ ) obtained by radical polymerization reaction of a monomer containing a specific nitrogen-containing radical polymerizable unsaturated monomer (a), a carboxyl group-containing radical polymerizable unsaturated monomer ( The resin component (B ₂ ) obtained by radical polymerization reaction of the monomer containing b), and an organic acid with respect to 100 parts by weight of the solid content of the resin component (B ₁ ) and the resin component (B ₂ ) The present invention relates to an aqueous paint (II) containing 0.01 to 10 parts by weight of a catalyst (C) and adjusting the solubility parameter (SP value) of the resin component (B ₁ ) and the resin component (B ₂ ). Details will be described below.

Water-based paint (I)
The water-based paint (I) comprises 0.1 to 30% by weight of the nitrogen-containing radically polymerizable unsaturated monomer (a) represented by the formula (1) with respect to the total of the constituent monomers, and a carboxyl group. It is obtained by radical polymerization reaction of 1 to 20% by weight of the containing radical polymerizable unsaturated monomer (b) and 50 to 98.9% by weight of the other radical polymerizable unsaturated monomer (c). It is a water-based paint containing the obtained resin component (A).
Formula (1)

(In the formula (1), R represents a hydrogen atom or CH _3, ^{R 1} represents _-C n _H 2n OH, ^{R 2} is an alkyl group having 1-6 several hydrogen or C _-C m _{H 2m} OH represents m, n represents an integer of 2 to 6)

Nitrogen-containing radically polymerizable unsaturated monomer (a): Examples of the nitrogen-containing radically polymerizable unsaturated monomer (a) include N- (2-hydroxyethyl) (meth) acrylamide, N- (2- Hydroxypropyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N-methyl-N- (2-hydroxyethyl) (meth) acrylamide, N-ethyl-N- (2-hydroxyethyl) (Meth) acrylamide, N-methyl-N- (2-hydroxypropyl) (meth) acrylamide, N-methyl-N- (3-hydroxypropyl) (meth) acrylamide, N-ethyl-N- (2-hydroxypropyl) ) (Meth) acrylamide, N-ethyl-N- (3-hydroxypropyl) (meth) acrylamide, N, N-di- ( - hydroxyethyl) (meth) acrylamide, N, N-di - (2-hydroxypropyl) (meth) acrylamide, and the like. These may be used alone or in combination.
Among these, N- (2-hydroxyethyl) acrylamide, N, N-di- (2-hydroxyethyl) acrylamide, N-methyl-N- (2-hydroxyethyl) acrylamide, N-ethyl-N- (2-hydroxy) Ethyl) acrylamide is preferred from the viewpoints of curability and coating film performance.

Carboxyl group-containing radical polymerizable unsaturated monomer (b): Examples of the carboxyl group-containing radical polymerizable unsaturated monomer (b) include (meth) acrylic acid, maleic acid, crotonic acid, itaconic acid, fumaric acid. Examples thereof include monomers such as acids, and these can be used alone or in combination of two or more.

Other radical polymerizable unsaturated monomer (c): As the other radical polymerizable unsaturated monomer (c), as a hydroxyl group-containing radical polymerizable unsaturated monomer, for example, 2-hydroxyethyl (meta ) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate hydroxyalkyl (meth) acrylates of _C 2 -C ₈ acrylic acid or methacrylic acid such as (poly) ethylene glycol - mono (meth ) Acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate, etc .; these hydroxyl group-containing radical polymerizable unsaturated monomers and β-propiolactone, dimethylpropiolactone, butyrolactone, γ- Valerolactone, γ-caprolactone, γ-ca As a product name such as a reaction product with a lactone compound such as lilolactone, γ-lauryllactone, ε-caprolactone, and δ-caprolactone, Plaxel FM1 (trade name, caprolactone-modified (meth) acrylic acid hydroxy, manufactured by Daicel Chemical Industries, Ltd.) Esters), Plaxel FM2 (same as left), Plaxel FM3 (same as left), Plaxel FA-1 (same as left), Plaxel FA-2 (same as left), Plaxel FA-3 (same as left), etc .;
For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, etc. C ₁ -C ₁₈ alkyl or cycloalkyl esters of (meth) acrylic acid;

Alkoxysilyl group-containing radically polymerizable unsaturated monomer (d): As other radically polymerizable unsaturated monomer (c), an alkoxysilyl group-containing radically polymerizable unsaturated monomer (d) can be used. For example, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinyltripropoxysilane, vinylmethyldipropoxysilane, vinyldimethylpropoxysilane, γ -(Meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, and the like.

Monomer (e) having two or more radically polymerizable unsaturated groups in one molecule: As other radically polymerizable unsaturated monomer (c), two or more radically polymerizable unsaturated monomers in one molecule A monomer (e) having a saturated bond can be used. For example, divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di ( (Meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol diacrylate, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylol Propane tri (meth) acrylate, pentaeryth Tall di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, glycerol allyloxy di (Meth) acrylate, 1,1,1-tris (hydroxymethyl) ethanedi (meth) acrylate, 1,1,1-tris (hydroxymethyl) ethanetri (meth) acrylate, and the like.

Radical polymerizable unsaturated monomer (f): As the other radical polymerizable unsaturated monomer (c), the radical polymerizable unsaturated monomer (f) represented by the formula (2) may be used. For example, N-methylolacrylamide, N-methoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, Ni-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, Ni -Butoxymethyl (meth) acrylamide etc. are mentioned. Other radically polymerizable unsaturated monomers (c) can be used alone or in combination of two or more.
As the blending ratio of these monomers, the nitrogen-containing radical polymerizable unsaturated monomer (a) is 0.1% with respect to the total of the radical polymerizable unsaturated monomers constituting the resin component (A). -30% by weight, preferably 3-15% by weight. The carboxyl group-containing radical polymerizable unsaturated monomer (b) is preferably 1 to 20% by weight, and the other radical polymerizable unsaturated monomer (c) is preferably 50 to 98.9% by weight.
If the nitrogen-containing radically polymerizable unsaturated monomer (a) is less than 0.1% by weight, sufficient curability cannot be obtained, and if it exceeds 30% by weight, chemical resistance decreases. If the carboxyl group-containing radically polymerizable unsaturated monomer (b) is less than 1% by weight, the coating stability is poor, and if it exceeds 20% by weight, the coating stability and chemical resistance are lowered.

Moreover, 0.1-20 weight% and / or the alkoxysilyl group containing radically polymerizable unsaturated monomer (d) with respect to the sum total of the radically polymerizable unsaturated monomer which comprises the resin component (A) and / or. By blending the monomer (e) having two or more radically polymerizable unsaturated groups in one molecule within a range of 0.1 to 20% by weight, the gloss of the coating film can be appropriately adjusted. . Furthermore, coating-film performance improves further by mix | blending the radically polymerizable unsaturated monomer (f) represented by Formula (2) within the range of 1 to 15 weight%.
Formula (2)

(In the formula (2), R represents a hydrogen atom or CH ₃ , and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)

Monomer (a), monomer (b), monomer (c), and monomer (d), monomer (e), monomer (f) were added as necessary. The radical polymerization reaction is carried out in the presence of an inert gas such as nitrogen in an organic solvent maintained at about 50 ° C to about 300 ° C, preferably about 60 ° C to 250 ° C. Each resin component can be obtained by radical polymerization reaction for a period of time to about 24 hours, preferably about 2 hours to about 10 hours.
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 suitably 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 component (A) is preferably in the range of 5,000 to 100,000, particularly 20,000 to 80,000, the acid value is in the range of 5 to 180 mgKOH / g, and the hydroxyl group. A value of 3 to 150 mgKOH / g is suitable.
(Note 1) Weight average molecular weight: Measured according to JIS K 0124-83, using TSK GEL4000H _XL + G3000H _XL + G2500H _XL + G2000H _XL (manufactured by Tosoh Corporation) as a separation column at a flow rate of 1.0 ml. / Min, using GPC tetrahydrofuran as the eluent, and calculated from the chromatogram obtained with the RI refractometer and the polystyrene calibration curve.

Water-based paint (II)
The water-based paint (II) is a resin component (B ₁ ) and a resin component (B ₂ ), and the difference in solubility parameter (Note 2) between the resin component (B ₁ ) and the resin component (B ₂ ) is 0. the resin component is in the range of .5~2.0 _{(B 1)} and resin component _(B 2), and 100 parts by weight of the solid content of the resin component _{(B 1)} and resin component _{(B 2),} organic acids It is a water-based paint containing 0.01 to 10 parts by weight of the catalyst (C).
Resin component (B ₁ ): The resin component (B ₁ ) contains 0.1 to 30% by weight of the nitrogen-containing radical polymerizable unsaturated monomer (a) represented by the formula (1), and contains a carboxyl group It is obtained by radical polymerization reaction of the radically polymerizable unsaturated monomer (b) and / or other radically polymerizable unsaturated monomer (c) at a ratio of 70 to 99.9% by weight.
Formula (1)

(In the formula (1), R represents a hydrogen atom or CH _3, ^{R 1} represents _-C n _H 2n OH, ^{R 2} is an alkyl group having 1-6 several hydrogen or C _-C m _{H 2m} OH represents m and n represents an integer of 2 to 6)

Resin component (B ₂ ): Next, the resin component (B ₂ ) contains 1 to 20 wt% of the carboxyl group-containing radical polymerizable unsaturated monomer (b), and is represented by the formula (1). It is a resin component obtained by radical polymerization reaction of the radically polymerizable unsaturated monomer (a) and / or other radically polymerizable unsaturated monomer (c) in a proportion of 80 to 99% by weight. .
(Note 2) Solubility parameter (SP value): The solubility parameter (SP value) is an abbreviation for (solubility parameter) and represents a measure of intermolecular interaction of liquid molecules. The SP value can be measured by cloud point titration. Specifically, the following formula (3), K.P. W. SUH, J. et al. M.M. It can be calculated according to the CORBETT equation (Journalof Applied Polymer Science, 12, 2359, 1968).
Formula (3)

(In the formula (3), the volume fraction of _{V H} is n- hexane, the volume fraction of _{V D} deionized water, the SP value of [delta] _H is n- hexane, [delta] _D is the SP value of the deionized water )
In the cloud point titration, 0.5 g of resin (solid content) as a sample was dissolved in 10 ml of acetone, n-hexane was gradually added, and the titration amount H (ml) at the cloud point was read. The titration amount D (ml) at the turbidity point by adding ion water is read, and these are applied to the following formulas to calculate V _H , V _D , δ _H , and δ _D. In addition, SP value of each solvent is acetone: 9.75, n-hexane: 7.24, deionized water: 23.43.
[V _H = H / (10 + H), V _D = D / (10 + D), δ _H = 9.75 × 10 / (10 + H) + 7.24 × H / (10 + H), δ _D = 9.75 × 10 / (10 + D) + 23.43 × D / (10 + D)]

As the nitrogen-containing radically polymerizable unsaturated monomer (a) in the resin component (B ₁ ), the same monomer as that used for the resin component (A) can be used.
Specifically, for example, N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N-methyl- N- (2-hydroxyethyl) (meth) acrylamide, N-ethyl-N- (2-hydroxyethyl) (meth) acrylamide, N-methyl-N- (2-hydroxypropyl) (meth) acrylamide, N-methyl -N- (3-hydroxypropyl) (meth) acrylamide, N-ethyl-N- (2-hydroxypropyl) (meth) acrylamide, N-ethyl-N- (3-hydroxypropyl) (meth) acrylamide, N, N-di- (2-hydroxyethyl) (meth) acrylamide, N, N-di- (2-hydroxypropy ) (Meth) acrylamide, and the like. These may be used alone or in combination.

In addition, the same monomers used for the resin component (A) are used for the carboxyl group-containing radical polymerizable unsaturated monomer (b) and other radical polymerizable unsaturated monomers (c). can do.
As a blending ratio of the above-mentioned monomer, the nitrogen-containing radically polymerizable unsaturated monomer (a) is added to the total of the radically polymerizable unsaturated monomers constituting the resin component (B ₁ ) by 0.00. 1 to 30% by weight, carboxyl group-containing radically polymerizable unsaturated monomer (b) and / or other radically polymerizable unsaturated monomer (c) in a proportion of 70 to 99.9% by weight. It is preferable from the viewpoint of curability and chemical resistance. When the carboxyl group-containing radically polymerizable unsaturated monomer (b) is used, it is preferably 5% by weight or less from the viewpoint of coating stability.
In the resin component (B ₂ ), the carboxyl group-containing radical polymerizable unsaturated monomer (b) contained as an essential component can be the same monomer as used for the resin component (A). . Specific examples include monomers such as (meth) acrylic acid, maleic acid, crotonic acid, itaconic acid, and fumaric acid, and these can be used alone or in combination of two or more.
Moreover, about the nitrogen-containing radically polymerizable unsaturated monomer (a) and the other radically polymerizable unsaturated monomer (c), the same monomer as that used for the resin component (A) is used. be able to.

As a blending ratio of the above monomer, the carboxyl group-containing radical polymerizable unsaturated monomer (b) is 1 with respect to the total of the radical polymerizable unsaturated monomers constituting the resin component (B ₂ ). ~ 20 wt%, 80 to 99 wt% of the nitrogen-containing radically polymerizable unsaturated monomer (a) and / or other radically polymerizable unsaturated monomer (c) represented by the above formula (1) Is preferable from the viewpoint of chemical resistance and paint stability. When using a nitrogen-containing radically polymerizable unsaturated monomer (a), the range of 0.1 to 30% by weight is preferable from the viewpoint of curability and chemical resistance.
Here, the resin component (B ₁₎ and the monomer to be used in the resin component (B ₂₎ may be a resin component (B ₁₎ and / or the resin component (B ₂₎ at a particular nitrogen-containing radical- It is possible to select a monomer so that the functional group ratio of the amide group to the carboxyl group of the monomer (a) is amide group / carboxyl group = 0.3 to 1.5. From the viewpoints of safety and chemical resistance.

The water-based paint (II) adjusts the gloss of the coating film by setting the difference in solubility parameter (SP value) between the resin component (B ₁ ) and the resin component (B ₂ ) to 0.5 to 2.0. be able to.
Furthermore, the alkoxysilyl group-containing radically polymerizable unsaturated monomer (d) is added to the total amount of the radically polymerizable unsaturated monomer constituting the resin component (B ₁ ) and the resin component (B ₂ ) by 0. By blending the monomer (e) having 1 to 20% by weight and / or two or more radically polymerizable unsaturated groups in one molecule in the range of 0.1 to 20% by weight, a coating with further low gloss A membrane can be obtained.
The radical polymerization reaction of the resin component (B ₁ ) and the resin component (B ₂ ) described above is performed by the above-described nitrogen-containing radical polymerizable unsaturated monomer (a) and carboxyl group-containing radical polymerizable unsaturated monomer. (B) and other radical polymerizable unsaturated monomer (c) are selected according to the purpose, and are about 50 ° C. to about 300 ° C., preferably about 60 ° C. to 250 ° C. in the presence of an inert gas such as nitrogen. Each resin component can be obtained by subjecting a radical polymerizable unsaturated monomer to a radical polymerization reaction in an organic solvent maintained at a temperature of about 1 hour to about 24 hours, preferably about 2 hours to about 10 hours. it can.

As the organic solvent used for the radical polymerization reaction, one or more kinds similar to those used for the synthesis of the resin component (A) can be used. As the polymerization initiator used for the radical polymerization reaction, one or more kinds similar to those used for the synthesis of the resin component (A) can be used.
The weight average molecular weight (see Note ₁ ) of the resin component (B ₁ ) thus obtained is in the range of 500 to 50,000, preferably 2,000 to 30,000, and the acid value is in the range of 50 mgKOH / g or less. The hydroxyl value is suitably in the range of 3 to 150 mgKOH / g.
The weight average molecular weight (see Note 1) of the resin component (B ₂ ) is 5,000 to 100,000, preferably 20,000 to 80,000, and the acid value is 5 to 180 mgKOH / g. The hydroxyl value is suitably in the range of 3 to 150 mgKOH / g.
Although it is the compounding ratio of the resin component (B ₁ ) and the resin component (B ₂ ) in the water-based paint (II), the resin component (B ₁ ) / resin component (B ₂ ) = 10/90 to 90 / by weight ratio. 10, preferably in the range of 20/80 to 80/20.

Organic acid catalyst (C):
The organic acid catalyst (C) used as an essential component in the water-based paint (I) or water-based paint (II) of the present invention includes an amide group and a carboxyl group of the specific nitrogen-containing radically polymerizable unsaturated monomer (a). The purpose is to promote the condensation reaction.
Examples of the organic acid catalyst (C) include n-butylbenzene sulfonic acid, n-aminobenzene sulfonic acid, n-octyl sulfonic acid, n-octyl benzene sulfonic acid, n-dodecyl benzene sulfonic acid, and n-octadeciber benzene. Sulfonic acid, n-dibutylbenzene sulfonic acid, isopropyl naphthalene sulfonic acid, dodecyl naphthalene sulfonic acid, dinonyl naphthalene disulfonic acid, dinonyl naphthalene sulfonic acid, paratoluene sulfonic acid, xylene sulfonic acid, pentadecyl benzene sulfonic acid, cumene sulfonic acid , Methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, trichloromethanesulfonic acid, trifluoroacetic acid, trichloroacetic acid and the like, and these can be used alone or in combination of two or more.
Among these, dinonylnaphthalenesulfonic acid and methanesulfonic acid are preferable from the viewpoint of curability. As the amount of the organic acid catalyst (C), 100 parts by weight of the solid content of the resin component (resin component (A), or the resin component _{(B 1)} and resin component _(B 2)), 0. 01-10 weight part is preferable.
These are one or more equivalents of basic compounds such as ammonia, diethylamine, ethylethanolamine, diethanolamine, monoethanolamine, monopropanolamine, isopropanolamine, ethylaminoethylamine, hydroxyethylamine, diethylenetriamine and other organic amines, and caustic soda, Neutralize with alkali metal hydroxide such as caustic.

Polyhydric alcohol (D):
Furthermore, water-based paint (I) and water-based paint (II) are blended with polyhydric alcohol (D) for the purpose of reducing volatile organic compounds instead of using volatile organic compounds that volatilize from the water-based paint at a low boiling point. can do.
The polyhydric alcohol (D) is a dihydric alcohol such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,6-hexanediol, Neopentyl glycol, 2-methyl-2,4-pentanediol, etc .; trihydric or higher alcohols include glycerin, trimethylolpropane, trimethylolethane, diglycerin, triglycerin, 1,2,6-hexanetriol, penta Erythritol, dipentaerythritol, sorbitol, etc .; Examples of alicyclic polyhydric alcohols include 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, etc., and these may be used alone or in combination of two or more. it can.
Among these, ethylene glycol, propylene glycol, glycerin, diethylene glycol, 2-methyl-2,4-pentanediol and the like are preferable. As a compounding quantity of a polyhydric alcohol (D), 20 weight part or less is preferable with respect to 100 weight part of resin solid content total.

Epoxy resin modified with phosphoric monoester and monobasic acid (E):
Furthermore, the water-based paint (I) and the water-based paint (II) can be appropriately mixed with a phosphoric acid monoester and an epoxy resin (E) modified with a monobasic acid for the purpose of improving the coating film performance.
Phosphoric acid monoester and phosphoric acid monoester which is a reaction product of monobasic acid and epoxy resin and epoxy resin modified with monobasic acid (E) (hereinafter, epoxy resin modified with phosphoric acid monoester and monobasic acid ( E) is referred to as “modified epoxy resin (E)”.)
Examples of the phosphoric acid monoester include orthoalkyl monoalkyl esters such as orthophosphoric acid monomethyl ester, orthophosphoric acid monoethyl ester, orthophosphoric acid monopropyl ester, orthophosphoric acid monobutyl ester, and orthophosphoric acid monostearyl ester.
Examples of the monobasic acid include fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, coconut oil fatty acid, castor oil fatty acid, and aromatics such as benzoic acid and p-ter-butylbenzoic acid. Examples include acids.
The above epoxy resin is a condensate of epichlorohydrin and bisphenol having an epoxy equivalent of 100 to 4,000 and having one or more epoxy groups in one molecule. For example, Epicoat 828, 1001 on the left, 1004, left 1007, and left 1009 (above, manufactured by Japan Epoxy Resin Co., Ltd.).
The production of the modified epoxy resin (E) is, for example, 0.5 to 1.5 mol of phosphoric acid monoester, preferably 0.8 to 1.2 mol, and 0.5 mol of monobasic acid with respect to 1 mol of epoxy resin. It is obtained by reacting at a ratio of ˜1.5 mol, preferably 0.8 to 1.2 mol.
The blending amount of the modified epoxy resin (E) is 0.01 to 10 parts by weight with respect to 100 parts by weight of the solid content of the resin component (A) or the resin component (B ₁ ) and the resin component (B ₂ ). It is preferable in terms of performance.

About anionic electrodeposition paint As the coating method of the water-based paint (I) or the water-based paint (II) described above, electrodeposition coating,
It can be applied by airless spray, air spray, electrostatic coating, brush, roll coater, curtain flow, or the like. Among these, it is preferable that the coating film is formed by electrodeposition coating, particularly anion electrodeposition coating, and it will be described on the assumption that an aqueous coating material is used as the anion electrodeposition coating material.
Hereinafter, the aqueous paint (I) is referred to as an anionic electrodeposition paint (I), and the aqueous paint (II) is referred to as an anion electrodeposition paint (II).
The anion electrodeposition paint (I) or the anion electrodeposition paint (II) is produced by using the resin component (A) and the organic acid catalyst (C) in the anion electrodeposition paint (I) and the anion electrodeposition paint (II). After blending two types of resin, resin component (B ₁ ) and resin component (B ₂ ), and organic acid catalyst (C), polyhydric alcohol (D), modified epoxy resin (E), and further necessary Depending on the case, a block polyisocyanate compound, a melamine resin, a pigment, a dye, a flow regulator, an ultraviolet absorber, and a light stabilizer can be blended.
Next, a neutralizing equivalent of 0.1 to 1.5 equivalent, preferably 0.2 to 1.2 equivalent of a neutralizing agent, for example, ethylamine, propylamine, butylamine, benzylamine, relative to the carboxyl group of the resin component Primary monoamines such as monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol; di-n- or di-iso-propanolamine, N-methylethanolamine, N-ethylethanolamine, etc. Secondary monoamines; tertiary monoamines such as dimethylethanolamine, trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine, dimethylaminoethanol; diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, methyl A polyamine triethylamine such as minopropylamine is blended and mixed, and then deionized water is gradually added to the mixture so that the solid content is 5 to 60% by weight, preferably 10 to 40% by weight. It is adjusted with a neutralizing agent so as to be 0.0 to 9.0, and is adjusted with deionized water so as to have a solid content of 5 to 20% by weight, and an anionic electrodeposition paint (I) or an anion electrodeposition paint ( II) can be obtained.
In order to form a coating film using the anionic electrodeposition paint (I) or the anion electrodeposition paint (II), the anion electrodeposition paint obtained above is put in a bathtub, and an aluminum material is put in this. After soaking, anion electrodeposition coating is performed so that the dry film thickness is about 5 to 30 μm, water washing is not performed (non-rinse) or water washing (rinsing), and then set at room temperature, then 120 to 200 ° C. Preferably, the coating film can be formed by baking and drying at 160 to 180 ° C. for about 20 to 40 minutes.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited thereby. “Parts” and “%” indicate “parts by weight” and “% by weight”.

About Anionic Electrodeposition Paint (I) Production Example 1 Resin Solution No. 1 production example (used for anion electrodeposition coating (I))
Into a reaction vessel, 16.7 parts of isopropyl alcohol and 13.3 parts of propylene glycol monomethyl ether were charged and kept at 80 ° C., and the following “mixture (1)” was dropped over 4 hours, followed by azobisdimethylvaleronitrile. 0.5 part is added, it reacts by hold | maintaining at 80 degreeC for 3 hours, Furthermore, it adjusts with propylene glycol monomethyl ether, Resin solution No. 60 with a solid content of 60 weight%. 1 was produced. Resin solution No. 1 had an acid value of 63 mgKOH / g, a hydroxyl value of 98 mgKOH / g, and a weight average molecular weight of about 35,000.

“Mixture (1)”
N- (2-hydroxyethyl) acrylamide 10 parts Acrylic acid 8 parts Styrene 10 parts Methyl methacrylate 30 parts Ethyl acrylate 10 parts N-Butyl acrylate 22 parts 2-Hydroxyethyl acrylate 10 parts Azobisdimethylvaleronitrile 1.5 parts

Production Examples 2 to 12 (used in Examples of anionic electrodeposition paint (I))
Instead of “Mixture (1)” in Production Example 1, resin solution No. 1 was prepared in the same manner as in Production Example 1 except that the content of the blend was changed to the content of Table 1. 2 Resin solution No. 2 12 was obtained.

Production Examples 13 to 16 (used for Comparative Examples of Anion Electrodeposition Paint (I))
Instead of “Mixture (1)” in Production Example 1, the resin solution no. 13 to Resin Solution No. 16 was obtained.

Example 1 Anionic electrodeposition paint No. 1 Production Example 1 Resin Solution No. 1 prepared in Production Example 1 1 After adding 1667 parts (solid content 1000 parts), dinonylnaphthalenesulfonic acid 10 parts (10 parts), and triethylamine 0.4 equivalent, deionized water was gradually added dropwise while stirring, Triethylamine was added so that the pH was 8.2, adjusted with deionized water, and an anionic electrodeposition paint No. 10 having a solid content of 10%. 1 was obtained.

Examples 2 to 14 Anion electrodeposition paint No. 2-No. 14 Production Example In the same manner as in Example 1, an anionic electrodeposition paint No. 1 having a formulation of Table 3 and a solid content of 10% was prepared. 2-No. 14 was obtained.

(Note 3) Modified epoxy resin: coconut oil fatty acid / Epicoat 828 (trade name, epoxy resin, manufactured by Japan Epoxy Resin Co., Ltd.) / Monobutyl phosphate = 1/1/1 molar ratio reactant

Comparative Examples 1-6 Anionic electrodeposition paint No. 15-No. Production Example 20 In the same manner as in Example 1, an anionic electrodeposition paint No. 1 having a composition as shown in Table 4 and a solid content of 10% was prepared. 15-No. 20 was obtained.

(Note 4) Nicarax MX430: manufactured by Sanwa Chemical Co., Ltd., trade name, butoxylated melamine resin, solid content 100%
(Note 5) Duranate 24A-90CX: Asahi Kasei Kogyo Co., Ltd., trade name, block polyisocyanate, solid content 80%
About preparation of a test board About 10 micrometers of film thickness which gave secondary electrolytic treatment (degreasing-etching-neutralization-anodizing treatment-sealing) using the anion electrodeposition paint obtained by the Example and the comparative example as a bath Anodized aluminum material (silver: size: 150 × 70 × 0.5 mm) was immersed, electrodeposition was applied so that the dry film thickness was 10 μm, washed with water, and baked at 180 ° C. for 20 minutes.
Regarding the test results, the anion electrodeposition paint No. 1-No. Table 14 shows examples of anion electrodeposition paint No. 15-No. Table 6 shows 20 comparative examples. In addition, the coating-film performance was used for the test according to the following test conditions.

(Note 7) Formaldehyde emission:
The amount of formaldehyde released was measured by the following method.
2 g of the electrodeposition coating film before baking is scraped off and placed in a sealed glass bottle, baked at 150 ° C. for 30 minutes, cooled, heated to 50 ° C., and 10 ml of deionized water is added and stirred well. Thereto was added 5 ml of dinitrophenylhydrazine hydrochloride acidic solution, left for 30 minutes, extracted with 5 ml of chloroform, and quantified with HPLC-8020 (trade name, liquid chromatography, manufactured by Tosoh Corporation).
◎: Less than 10 μg of formalin emission per gram of coating film (dry) ○: Less than 10 μg of formalin emission per gram of coating film (dry) and less than 20 μg Δ is formalin per gram of coating film (dry) Emission amount of 20 μg or more and less than 500 μg × indicates that formalin emission amount per 1 g of coating film (dry) is 500 μg or more (Note 8) Emission amount of volatile organic compounds:
The amount of volatile organic compounds emitted was measured by the following method.
2 g of the electrodeposition coating film before baking is scraped off and placed in a sealed glass bottle and baked at 150 ° C. for 30 minutes. After cooling, 10 ml of deionized water is added and stirred well. After leaving for 30 minutes,
Quantification was performed with GC-15A (manufactured by Shimadzu Corporation, trade name, gas chromatography).
◎ indicates that the volatile organic compound in the extract is less than 0.5%. ○ indicates that the volatile organic compound in the extract is 0.5% or more and less than 1.0%. When the organic compound is 1.0% or more and less than 3.0%, the volatile organic compound in the extract is 3.0% or more (Note 9) Gel fraction:
The gel fraction was measured by the following method.
After electrodeposition coating and washing with water, the test plate baked at 180 ° C. for 20 minutes is put into a separate type round bottom flask, 100 g of acetone is added to 1 g of the cured coating film, and the mixture is refluxed for 5 hours. Next, after drying at 105 ° C. for 1 hour, the coating weight before and after reflux was measured and calculated by applying to the following formula.
Gel fraction (%) = weight of coating film after reflux / weight of coating film before reflux × 100
(Note 10) Chemical resistance (alkali resistance):
Chemical resistance (alkali resistance) was measured by the following method.
After immersing in a 0.5% aqueous sodium hydroxide solution at 20 ° C. for 100 hours, the coated surface was examined for abnormalities.
◎: No abnormality ○: Slightly inferior but good without any practical problem △: Abnormality ×: Remarkable abnormality is observed (Note 11) Paint stability: paint in a test tube (height 20 cm, capacity 20 ml) After filling and allowing to stand at 20 ° C. for 7 days, the height of the residue precipitated on the bottom of the container was examined.
Indicates that the residue is less than 0.5 mm, the residue is 0.5 mm or more and less than 10 mm, and the residue is 10 mm or more (Note 12) 60 degree specular gloss:
The degree of gloss of the coating film was measured according to the 60 degree specular gloss of JIS K-5400 7.6 (1990), and the reflectivity was measured when the incident angle and the light receiving angle were 60 degrees. Expressed as a percentage when the glossiness of the reference surface is 100

About Anionic Electrodeposition Paint (II) Production Example 17 Production Example of Resin Component (B ₁ ) (For Anion Electrodeposition Paint (II))
Into a reaction vessel, 16.7 parts of isopropyl alcohol and 13.3 parts of propylene glycol monomethyl ether were charged and kept at 80 ° C., and the following “mixture (2)” was dropped over 4 hours, followed by azobisdimethylvaleronitrile. 0.5 part is added, it reacts by hold | maintaining at 80 degreeC for 3 hours, Furthermore, it adjusts with propylene glycol monomethyl ether, Resin solution No. 60 with a solid content of 60 weight%. 17 was produced. Resin solution No. 17 had a hydroxyl value of 57 mgKOH / g, a weight average molecular weight of about 12,000, and an SP value of 9.18.

"Mixture (2)"
Styrene 10 parts Methyl methacrylate 38 parts Ethyl acrylate 10 parts n-Butyl acrylate 30 parts 2-hydroxyethyl acrylate 12 parts Azobisdimethylvaleronitrile 8 parts

Production Examples 18 to 26 Production Examples of Resin Component (B ₁ ) (for Anion Electrodeposition Paint (II))
Instead of “Mixture (2)” in Production Example 17, the resin solution no. 18-Resin solution No. 26 was obtained.

(Note 13) KBM-503: Shin-Etsu Chemical Co., Ltd., trade name, γ-methacryloxypropyltrimethoxysilane

Production Example 27 Production Example of Resin Component (B ₂ ) (For Anion Electrodeposition Paint (II))
Into a reaction vessel, 16.7 parts of isopropyl alcohol and 13.3 parts of propylene glycol monomethyl ether were charged, and the following “mixture (3)” was dropped into the reaction vessel over 4 hours, followed by azobisdimethylvaleronitrile. 0.5 part is added, it reacts by hold | maintaining at 80 degreeC for 3 hours, Furthermore, it adjusts with propylene glycol monomethyl ether, Resin solution No. 60 with a solid content of 60 weight%. 27 was produced. Resin solution No. No. 27 had a weight average molecular weight of about 35000, an acid value of 5 mgKOH / g, a hydroxyl value of 76 mgKOH / g, and an SP value of 10.48.

"Mixture (3)"
Acrylic acid 0.5 parts Styrene 13 parts Methyl methacrylate 48.5 parts Ethyl acrylate 5 parts n-Butyl acrylate 17 parts 2-hydroxyethyl acrylate 16 parts Azobisdimethylvaleronitrile 1.5 parts

Production Examples 28 to 35 Production Example of Resin Component (B ₂ ) Table 8 was prepared in the same manner as in Production Example 27 except that the content of blending was changed to that shown in Table 8 instead of “Mixture (3)” in Production Example 17. The resin solution No. 28-Resin solution No. 35 was obtained.

Example 15 Anion electrodeposition paint no. Production Example No. 21 Resin Solution No. 18 667 parts (solid content 400 parts), Resin Solution No. 29 After adding 1000 parts (solid content: 600 parts), dinonylnaphthalenesulfonic acid (10 parts) (solid content: 10 parts) and triethylamine (0.4 equivalents) and mixing and dispersing, deionized water was gradually added dropwise while stirring. Further, triethylamine was added so that the pH was 8.2, and the pH was adjusted with deionized water. 21 was obtained.
Examples 16 to 25 Anionic electrodeposition paint No. 22-No. Production Example No. 31 In the same manner as in Example 15, an anionic electrodeposition paint No. 1 having a composition of Table 7 and a solid content of 10% was prepared. 22-No. 31 was obtained.

Comparative Example 7 Anionic electrodeposition paint No. Production Example No. 32 Resin Solution No. 18 667 parts (solid content 400 parts), Resin Solution No. 28 After adding 1000 parts (solid content 600 parts), dinonylnaphthalenesulfonic acid 10 parts (10 parts) and triethylamine 0.4 equivalents, mixing and dispersing, deionized water was gradually added dropwise with stirring, Triethylamine was added so that the pH was 8.2, adjusted with deionized water, and an anionic electrodeposition paint No. 10 having a solid content of 10%. 32 was obtained.

Comparative Examples 8 to 15 Anionic electrodeposition paint No. 33-No. 40, an anionic electrodeposition paint No. of Comparative Examples 8 to 15 with the contents of Table 10 by the same operation as in Comparative Example 7 33-No. 40 was obtained.

  Table 11 shows the anion electrodeposition paint Nos. Of Examples. 21-No. 31 is shown in Table 12 as an anionic electrodeposition paint No. 32-No. 40. In addition, the coating-film performance was used for the test according to the said test conditions.

  INDUSTRIAL APPLICATION This invention can obtain the coating article by the aqueous coating material which reduced generation | occurrence | production of the formaldehyde from a coating film at the time of baking, or a blocking agent (volatile organic compound).

Claims (8)

The nitrogen-containing radically polymerizable unsaturated monomer (a) represented by the following formula (1) is 0.1 to 30% by weight, the carboxyl group-containing radically polymerizable monomer, based on the total of the constituent monomers. Resin component obtained by radical polymerization reaction of a mixture of 1 to 20% by weight of the saturated monomer (b) and 50 to 98.9% by weight of the other radical polymerizable unsaturated monomer (c) ( A) and a water-based paint containing 0.01 to 10 parts by weight of the organic acid catalyst (C) with respect to 100 parts by weight of the solid content of the resin component (A).
Formula (1)

(In the formula (1), R represents a hydrogen atom or CH _3, ^{R 1} represents _-C n _H 2n OH, ^{R 2} is a hydrogen atom, alkyl group having 1 to 6 carbon atoms or _-C m _{H 2m} OH represents m and n represents an integer of 2 to 6) The difference in solubility parameter (SP value) between the resin component (B ₁ ) and the resin component (B ₂ ), and the resin component (B ₁ ) and the resin component (B ₂ ) is 0.5-2. 0 resin component is in the range of _{(B 1)} and resin component _(B 2), and a resin component and _{(B 1)} 100 parts by weight of the solid content of the resin component _{(B 2),} an organic acid catalyst (C) A water-based paint containing 0.01 to 10 parts by weight.
Resin component (B ₁ ): 0.1 to 30% by weight of the nitrogen-containing radical polymerizable unsaturated monomer (a) represented by the following formula (1) with respect to the total amount of the constituent monomers By containing a carboxyl group-containing radical polymerizable unsaturated monomer (b) and / or another radical polymerizable unsaturated monomer (c) in a radical polymerization reaction of a mixture of 70 to 99.9% by weight. Obtained resin component (B ₁ )
Resin component (B ₂ ): 1 to 20% by weight of the carboxyl group-containing radical polymerizable unsaturated monomer (b), and a nitrogen-containing radical polymerizable unsaturated monomer represented by the following formula (1) Resin component (B ₂ ) obtained by radical polymerization reaction of (a) and / or other radical polymerizable unsaturated monomer (c) at a ratio of 80 to 99% by weight
Formula (1)

(In the formula (1), R represents a hydrogen atom or CH _3, ^{R 1} represents _-C n _H 2n OH, ^{R 2} is an alkyl group of 2-6 several hydrogen or C _-C m _{H 2m} OH represents m and n represents an integer of 1 to 6)   The nitrogen-containing radically polymerizable unsaturated monomer (a) represented by the formula (1) is N- (2-hydroxyethyl) acrylamide, N, N-di- (2-hydroxyethyl) acrylamide, N-methyl. The water-based paint according to claim 1 or 2, which is at least one selected from -N- (2-hydroxyethyl) acrylamide and N-ethyl-N- (2-hydroxyethyl) acrylamide.   The water-based paint according to any one of claims 1 to 3, comprising an alkoxysilyl group-containing radically polymerizable unsaturated monomer (d) as the other radically polymerizable unsaturated monomer (c). .   5. The monomer (e) having two or more radically polymerizable unsaturated groups in one molecule as the other radically polymerizable unsaturated monomer (c). The water-based paint described in the item. The radically polymerizable unsaturated monomer (f) represented by the following formula (2) is contained as the other radically polymerizable unsaturated monomer (c). The water-based paint described in 1.
Formula (2)

(In the formula (2), R represents a hydrogen atom or CH ₃ , and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)   The water-based paint according to any one of claims 1 to 6, wherein the water-based paint is an anionic electrodeposition paint.   A coated article obtained by coating the anodized aluminum with the water-based paint described in any one of claims 1 to 7.