JPWO2011099639A1 - Water-based coloring paint composition - Google Patents

Abstract

An object of the present invention is to provide a water-based colored coating composition that can form a colored coating film that has both water resistance and intermediate sharpening properties, and that has good coating workability and finish. is there. This water-based colored coating composition can be used for painting an automobile body and has the following configuration. An aqueous coloring paint composition comprising a base paint (I) and a diluent (II), wherein the base paint (I) comprises a core-shell acrylic emulsion (A), a core-shell acrylic emulsion (B), a urethane resin emulsion (C ), An acrylic pigment dispersion resin (D) and a color pigment (E), and the diluent (II) contains a carbodiimide compound and water.

Description

  The present invention relates to an aqueous colored coating composition, and more particularly to an aqueous colored coating composition useful as a top coating.

In order to improve the water resistance of a coating film formed from a water-based coating composition, it is well known to use a carbodiimide compound as a curing agent.
When the water-based resin contains a carboxyl group as a water-dispersing group, a carbodiimide group that can react with the carboxyl group is used as a crosslinking reactive group in the curing process of the coating film, thereby cross-linking while eliminating the hydrophilic carboxyl group. Since it can take in into reaction, the water resistance of the cured coating film formed improves.

  As a document using a carbodiimide compound as a curing agent, for example, Patent Document 1 proposes a thermosetting aqueous coating composition containing a specific hydrophilized modified polycarbodiimide compound and a carboxyl group-containing aqueous resin composition, and Patent Document 2 proposes a three-chain hydrophilic carbodiimide compound that can be cured at a relatively low temperature and provides a coating film with excellent water resistance, and an aqueous coating composition comprising the same.

  According to Patent Documents 1 and 2, it is described that these water-based coating compositions can achieve both curability and storage stability, and that the resulting coating film has good water resistance. Under relatively low temperature conditions such as drying and forced drying, a cured coating film having sufficient performance may not be obtained while satisfying the coating workability and finish performance.

  By the way, as a method for repairing automobile bodies and the like, a method of applying a base coat paint and then applying a clear coat paint has been widely performed. There is a need for the development of colored coating compositions.

  For example, in Patent Document 3, the present applicant has proposed an aqueous paint composition comprising a base coat paint containing an aqueous acrylic resin and an aqueous urethane resin, and a diluent containing a thickener.

JP 2001-11151 A JP 2003-306476 A JP2007-191686A

The water-based paint composition described in Patent Document 3 has a coating workability that is excellent in workability and finish such as a metallic feeling, adhesion, etc. even in coating sites where the coating environment such as humidity and temperature is significantly different. However, the formed coating film is soft, and there is room for further improvement in order to achieve both intermediate sharpness and water resistance.
Accordingly, an object of the present invention is to provide a water-based colored coating composition that can form a colored coating film that achieves both water resistance and intermediate sharpening properties, and that has good coating workability and finish. .

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an aqueous coloring paint composition containing a base paint (I) and a diluent (II), wherein the base paint (I) is a core-shell acrylic. An emulsion (A), a core-shell acrylic emulsion (B), a urethane resin emulsion (C), an acrylic pigment dispersion resin (D), and a coloring pigment (E), and the core portion of the core-shell acrylic emulsion (A) and / or Alternatively, the shell portion contains, as monomer units, methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ), and the ratio of methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) 40% by mass or more of the total monomer units of the core-shell acrylic emulsion (A), and the core-shell acrylic emma The core portion and / or shell portion of Luchon (B) contains, as a monomer unit, a linear or branched hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) having 6 or more carbon atoms, and a hydrocarbon group The content of the polymerizable unsaturated monomer (b ₁ ) is 20 to 80% by mass of the total monomer units of the core-shell acrylic emulsion (B), and methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) The ratio of ₁ ) is less than 40% by mass of the total monomer units of the core-shell acrylic emulsion (B), and the diluent (II) contains a carbodiimide compound and water. The present inventors have found that the above problems can be solved and have completed the present invention.

Specifically, the present invention relates to the following aspects.
[Aspect 1]
An aqueous coloring coating composition comprising a base coating (I) and a diluent (II),
The base paint (I) contains a core-shell acrylic emulsion (A), a core-shell acrylic emulsion (B), a urethane resin emulsion (C), an acrylic pigment dispersion resin (D), and a colored pigment (E).
The core part and / or the shell part of the core-shell type acrylic emulsion (A) contains methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as monomer units, and methyl (meth) acrylate and / or ethyl. The proportion of (meth) acrylate (a ₁ ) is 40% by mass or more of the total monomer units of the core-shell type acrylic emulsion (A),
The core part and / or shell part of the core-shell type acrylic emulsion (B) contains, as a monomer unit, a linear or branched hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) having 6 or more carbon atoms, The proportion of the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) is 20 to 80% by mass of the total monomer units of the core-shell type acrylic emulsion (B), and methyl (meth) acrylate and / or ethyl (meth). The proportion of acrylate (a ₁ ) is less than 40% by mass of the total monomer units of the core-shell acrylic emulsion (B),
Diluent (II) comprises a carbodiimide compound and water,
An aqueous coloring paint composition characterized by the above.

[Aspect 2]
In the core-shell type acrylic emulsion (A), the carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) is used as a monomer unit, and the solid content acid value of the core-shell type acrylic emulsion (A) is in the range of 5 to 40 mgKOH / g. The aqueous coloring coating composition according to aspect 1, further comprising such an amount.
[Aspect 3]
In the core-shell type acrylic emulsion (B), the carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) is used as a monomer unit, and the solid content acid value of the core-shell type acrylic emulsion (B) is in the range of 1 to 40 mgKOH / g. The aqueous coloring coating composition according to the aspect 1 or 2, further comprising such an amount.

[Aspect 4]
The water-based colored coating composition according to any one of aspects 1 to 3, wherein the core-shell acrylic emulsion (B) has a glass transition temperature in the range of -60 to 0 ° C.
[Aspect 5]
Based on the total solid content of the core-shell type acrylic emulsion (A), the core-shell type acrylic emulsion (B), the urethane resin emulsion (C), and the acrylic pigment dispersion resin (D),
The core-shell type acrylic emulsion (A) is 5 to 70% by mass in solid content,
The core-shell type acrylic emulsion (B) is 20 to 85% by mass in solid content,
The urethane resin emulsion (C) is 5 to 70% by mass in solid content,
Acrylic pigment-dispersed resin (D) in a solid content of 5 to 70% by mass,
The aqueous coloring coating composition as described in any one of the aspects 1-4 containing.

[Aspect 6]
The aqueous colored coating composition according to any one of aspects 1 to 5, wherein the diluent (II) contains a carbodiimide compound in the range of 0.1 to 20% by mass.
[Aspect 7]
In any one of Embodiments 1 to 6, the aqueous colored coating composition contains the diluent (II) in a range of 5 to 100 parts by mass with respect to 100 parts by mass of the solid content of the base coating (I). The aqueous coloring coating composition as described.

[Aspect 8]
In any one of Embodiments 1 to 7, the equivalent ratio of the carbodiimide group contained in the diluent (II) to the carboxyl group contained in the base paint (I) is in the range of 0.1 to 1.5. The aqueous coloring coating composition as described.

The water-based colored coating composition of the present invention can form a colored coating film that achieves both water resistance and moderate sharpness even under conditions of room temperature drying or forced drying.
Moreover, the specific base coating material which comprises the aqueous | water-based coloring coating composition of this invention, and the diluent containing a carbodiimide compound each have favorable storage stability, and can be easily mixed. Therefore, the water-based colored coating composition of the present invention is obtained by mixing both immediately before coating, has good workability in coating, and further, a colored coating film formed from the water-based colored coating composition of the present invention and The multilayer coating film formed by coating clear on the colored coating film has a good metallic feeling, jet blackness and the like, and is excellent in finish.

Hereinafter, the water-based colored coating composition of the present invention will be described in detail.
<Base paint (I)>
The base paint (I) used in the present invention contains a core-shell type acrylic emulsion (A), a core-shell type acrylic emulsion (B), a urethane resin emulsion, an acrylic pigment dispersion resin (D), and a colored pigment (E). . Hereinafter, it demonstrates in order.

<Core-shell type acrylic emulsion (A)>
In the present invention, the core portion and / or shell portion of the core-shell type acrylic emulsion (A) contains methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as a monomer unit.

In the core-shell acrylic emulsion (A), the proportion of methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as a monomer unit is about 40 mass of the total monomer units of the core-shell acrylic emulsion (A). % And more preferably in the range of about 60 to about 90% by weight.
When the ratio of methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) in the core-shell type acrylic emulsion (A) is less than about 40% by mass, the base paint (I) and the water-based colored paint of the present invention This is not preferable because the viscosity of the composition is lowered, the coating workability varies depending on the coating conditions, and the finish of the colored coating film formed, such as metallic feel and jetness, varies.

In the core-shell type acrylic emulsion (A), methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as monomer units are included as monomer units in the core part as long as the ratio is within the above range. It may be included as a monomer unit of the shell part, or may be included as a monomer unit of both the core part and the shell part.

Used for polymerization of monomer units other than methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) in the core portion and the shell portion of the core-shell type acrylic emulsion (A), that is, the core-shell type acrylic emulsion (A). Examples of the polymerizable unsaturated monomer that can be used include those conventionally known without limitation, such as n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) ) Straight chain or branched hydrocarbon group-containing polymerizable unsaturated monomers such as acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.); cyclohexyl (meth) acrylate, methylcyclohexyl (meta) ) Polymerizable unsaturated monomer having a cycloalkyl group such as acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate; Polymerizable unsaturated monomer having an isobornyl group such as isobornyl (meth) acrylate; ) Polymerizable unsaturated monomer having an adamantyl group such as acrylate; Aromatic vinyl monomer such as styrene, α-methylstyrene, vinyltoluene; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate Hydroxyl groups such as rate, 3-hydroxypropyl (meth) acrylate, hydroxyalkyl (meth) acrylates such as 4-hydroxybutyl (meth) acrylate, allyl alcohol, and ε-caprolactone modified products of the above hydroxyalkyl (meth) acrylates ( (Meth) acrylate; hydroxyl group-containing polymerizable unsaturated monomer such as (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end; carboxyl such as (meth) acrylic acid, maleic acid, crotonic acid, β-carboxyethyl acrylate, etc. Group-containing polymerizable unsaturated monomer: allyl (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2-propyl Polyvinyl compounds such as phenyl (meth) acrylate and 1,1,1-trishydroxymethylethanedi (meth) acrylate; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meta ) Alkoxysilyl group-containing polymerizable unsaturated monomers such as acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane; perfluorobutylethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, etc. Perfluoroalkyl (meth) acrylate; polymerizable unsaturated monomer having a fluorinated alkyl group such as fluoroolefin; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxy Epoxy group-containing polymerizable unsaturated monomers such as cyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether; maleimide groups, etc. Polymerizable unsaturated monomer having a photopolymerizable functional group; 1,2,2,6,6-pentamethylpiperidyl (meth) acrylate, 2,2,2,6,6-tetramethylpiperidinyl (meth) acrylate Etc .; vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate; (meth) acrylonitrile, (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, Glicisi Nitrogen-containing polymerizable unsaturated monomers such as adducts of ru (meth) acrylate and amines; (meth) acrylates having polyoxyalkylene chains whose molecular ends are alkoxy groups; 2-acrylamido-2-methylpropanesulfonic acid Polymerizable unsaturated monomers having a sulfonic acid group such as allyl sulfonic acid, sodium styrene sulfonate, sulfoethyl methacrylate and its sodium salt, ammonium salt; (2-acryloyloxyethyl) acid phosphate, (2-methacryloyloxyethyl) ) Acid phosphate, (2-acryloyloxypropyl) acid phosphate, (2-methacryloyloxypropyl) acid phosphate, acid phosphooxypolyethylene glycol mono (meth) acrylate, acid phosphate Oxypolypropylene glycol mono (meth) acrylate, acid phosphooxyhexaethylene glycol mono (meth) acrylate, acid phosphooxyhexapropylene glycol mono (meth) acrylate, acid phosphooxide decaethylene glycol mono (meth) acrylate, acid phosphooxide decapropylene Polymerizable unsaturated monomers having a phosphate group such as glycol mono (meth) acrylate; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrol, vinyl having about 4 to about 7 carbon atoms Carbonyl group-containing polymerizable unsaturated compounds such as alkyl ketones (eg, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) Mer, etc., and combinations thereof.
In the present specification, “(meth) acrylate” means acrylate and / or methacrylate.

In the core-shell type acrylic emulsion (A), the ratio of the core part to the shell part is preferably about 10/90 from the viewpoint of the finish of the colored coating film formed using the aqueous colored coating composition of the present invention. In the range of about 90/10, and more preferably in the range of about 20/80 to about 80/20.
The core-shell type acrylic emulsion (A) is, for example, a polymerizable unsaturated monomer mixture constituting a shell in an aqueous dispersion obtained by polymerizing a polymerizable unsaturated monomer mixture constituting a core in the presence of an emulsifier. Is obtained by polymerization.

The average particle size of the core-shell acrylic emulsion (A) is preferably in the range of about 0.01 to about 1.0 μm, and more preferably about 0.05 to about 0.5 μm.
In the present specification, the average particle diameter is a value measured by diluting a sample with deionized water with “Nanomizer N-4” (trade name, manufactured by Coulter, Inc., particle size distribution measuring apparatus) to 20 ° C. And

The core-shell type acrylic emulsion (A) contains a carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) as a monomer unit because it has the effect of making the viscosity of the aqueous colored coating composition moderate and improving the finish. It is preferable to do.
The carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) can be appropriately selected from the compounds listed above. The amount of the carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) is preferably from about 5 to about 40 mg KOH / g, and more preferably from about 10 to about 30 mg KOH / g, as the solid content acid value of the core-shell acrylic emulsion (A). The amount is within the range. The said range is preferable from a viewpoint of the water resistance and finishing property of the colored coating film formed from the water-based colored coating composition of this invention, and a viewpoint of coating workability | operativity.

  In the present specification, the “solid content” means a solid content from which volatile components such as water and organic solvent in the sample are removed, and is measured by drying about 2 g of the sample at 105 ° C. for 3 hours. be able to.

In the core-shell type acrylic emulsion (A), the carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) may be contained as a monomer unit of the core part, may be contained as a monomer unit of the shell part, or Although it may be contained as a monomer unit of both the core part and the shell part, it is preferably contained as a monomer unit of the shell part. This is because the storage stability of the core-shell type acrylic emulsion (A) and the finish of the colored coating film formed by the aqueous colored coating composition of the present invention are excellent.

Further, the core-shell acrylic emulsion (A), from the viewpoint of storage stability of the base paint (I), as a monomer unit preferably contains a hydroxyl group-containing polymerizable unsaturated monomer (a _3). The hydroxyl group-containing polymerizable unsaturated monomer (a ₃ ) can be appropriately selected from the compounds listed above. The amount of the hydroxyl group-containing polymerizable unsaturated monomer (a ₃ ) is preferably from about 1 to about 100 mgKOH / g, and more preferably from about 10 to about 50 mgKOH / g, based on the solid content hydroxyl value of the core-shell acrylic emulsion (A). The amount is within the range. The said range is preferable from the point of the water resistance and finishing property of the colored coating film formed from the water-based colored coating composition of this invention.

The hydroxyl group-containing polymerizable unsaturated monomer (a ₃ ) may be included as a monomer unit of the core portion, a monomer unit of the shell portion, or a core in the core-shell type acrylic emulsion (A). It may be included as both monomer units and shell units.

The core-shell type acrylic emulsion (A) contains a polyvinyl compound (a ₄ ) as a monomer unit from the viewpoint of the coating workability of the water-based colored coating composition of the present invention and the finish of the colored coating film to be formed. It is preferable to do. The other vinyl compound (a ₄ ) can be appropriately selected from the compounds listed above. The ratio of the polyvinyl compound (a ₄ ) is preferably about 0.1 to about 3.0% by mass, and more preferably about 0.1, based on the total amount of monomer units of the core-shell type acrylic emulsion (A). Is in the range of about 2.0% by weight.

In the core-shell type acrylic emulsion (A), the polyvinyl compound (a ₄ ) may be contained as a monomer unit of the core part, may be contained as a monomer unit of the shell part, or the core part and the shell part. These may be contained as both monomer units, but are preferably contained as monomer units in the core portion. This is because the storage stability and production stability of the core-shell type acrylic emulsion (A) and the finish of the colored coating film formed by the aqueous colored coating composition of the present invention are excellent.

The core-shell acrylic emulsion (A) preferably has a glass transition temperature in the range of about 0 to about 60 ° C, and more preferably about 10 to about 50 ° C.
In this specification, the glass transition temperature as an absolute temperature is a value calculated by the following formula.
1 / Tg = W1 / T1 + W2 / T2 +... Wn / Tn
In the formula, W1, W2... Wn are mass% of each monomer [= (blending amount of each monomer / total monomer mass) × 100], and T1, T2... Tn are homopolymer glass of each monomer. Transition temperature (absolute temperature). In addition, the glass transition temperature of the homopolymer of each monomer is a value according to Polymer Hand Book (4th Edition), and the glass transition temperature of the monomer not described in the above literature is a homopolymer of the monomer having a weight average molecular weight of 5 A value obtained by synthesizing to about 10,000 and measuring the glass transition temperature by differential scanning thermal analysis is used.

  As the polymerization initiator that can be used for the polymerization of the core-shell type acrylic emulsion (A), conventionally known polymerization initiators can be used without limitation, and examples thereof include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide. , Organic peroxides such as cumene hydroperoxide, tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydroperoxide; azobisiso Butyronitrile, azobis (2,4-dimethylvaleronitrile), azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4′-azobis (4- Anobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], azobis {2-methyl-N- [2- (1-hydroxy Butyl)]-propionamide}, persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate, and the like, and combinations thereof.

  Moreover, as an emulsifier that can be used for the polymerization of the core-shell type acrylic emulsion (A), an anionic emulsifier and a nonionic emulsifier are suitable. Examples of the anionic emulsifier include alkyl sulfonic acid, alkyl benzene sulfonic acid, and alkyl phosphoric acid. Examples include sodium salts and ammonium salts such as acids. Examples of the nonionic emulsifier include polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene phenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonylphenyl ether, Oxyethylene octyl phenyl ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate, sorbitan monolaurate, sorbitan monostearate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan A monolaurate etc. are mentioned.

  Furthermore, for polymerization of the core-shell type acrylic emulsion (A), a polyoxyalkylene group-containing anionic emulsifier having an anionic group and a polyoxyalkylene group such as a polyoxyethylene group or a polyoxypropylene group in one molecule; A reactive anionic emulsifier having an anionic group and a polymerizable unsaturated group in the molecule can be used.

When the core-shell type acrylic emulsion (A) has a carboxyl group by including a carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) as a monomer unit, the carboxyl group is neutralized with a neutralizing agent. can do. The neutralizing agent is not particularly limited. For example, ammonia, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, monoethanolamine, diethanolamine, butylamine, ethylenediamine, methylethanolamine, dimethylethanolamine, dimethylpropanolamine. An amine compound such as

<Core-shell type acrylic emulsion (B)>
In the present invention, the core part and / or the shell part of the core-shell type acrylic emulsion (B) is a linear or branched hydrocarbon group-containing polymerizable unsaturated monomer (b) having about 6 or more carbon atoms as a monomer unit. ₁ ).

In the core-shell acrylic emulsion (B), the proportion of the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) as the monomer unit is about 20 to about 80% by mass of the total monomer units of the core-shell acrylic emulsion (B). And preferably from about 30 to about 60% by weight.
If the proportion of the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) as the monomer unit is less than about 20% by mass, the formed coating film has insufficient water resistance, while if it exceeds about 80% by mass, the base paint Since the storage stability of (I) is insufficient, it is not preferable.

Specific examples of the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) include, for example, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl ( Examples thereof include (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), and combinations thereof.

In the core-shell type acrylic emulsion (B), the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) may be contained as a monomer unit of the core part as long as the ratio is within the above range. It may be included as a monomer unit, or may be included as a monomer unit of both the core part and the shell part.

In the core-shell acrylic emulsion (B), the proportion of methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as a monomer unit is about 40 mass of the total monomer units of the core-shell acrylic emulsion (B). %.

The core-shell type acrylic emulsion (B) is, for example, in an aqueous dispersion obtained by polymerizing a polymerizable unsaturated monomer mixture constituting the core in the presence of an emulsifier, as in the case of the core-shell type acrylic emulsion (A). The polymer is obtained by adding a polymerizable unsaturated monomer mixture constituting the shell and polymerizing.
The average particle diameter of the core-shell type acrylic emulsion (B) is preferably about 0.01 to about 1.0 μm, and more preferably about 0.05 to about 0.5 μm, like the core-shell type acrylic emulsion (A). Is in range.

In the present invention, by employing the “core-shell type” acrylic emulsion (B), the finish of the colored coating film formed from the aqueous colored coating composition of the present invention can be further improved.
In the core-shell acrylic emulsion (B), the ratio of the core portion to the shell portion is preferably in the range of about 10/90 to about 90/10, and more preferably about 20/80 to about 80/20. Is within the range. The above range is preferable from the viewpoint of setting the viscosity of the water-based colored coating composition of the present invention to a viscosity suitable for coating, the viewpoint of suppressing the viscosity reduction during storage, and the finish of the colored coating film.

Polymerization that can be used for the polymerization of monomer units other than the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) in the core portion and the shell portion of the core-shell type acrylic emulsion (B), that is, the core-shell type acrylic emulsion (B). Examples of the unsaturated monomer include those listed in the section of the core-shell type acrylic emulsion (A).
Examples of the polymerization initiator and the emulsifier used for the polymerization of the core-shell type acrylic emulsion (A) include those listed in the section of the core-shell type acrylic emulsion (A).

In addition, the core-shell type acrylic emulsion (B) is a carboxyl group-containing polymerizable unsaturated monomer (b ₂₎ as a monomer unit from the viewpoint of water-resistant adhesion of a colored coating film formed from the aqueous colored coating composition of the present invention. ) Is preferably contained.
Examples of the carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) include the same ones as the carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) described in the section of the core-shell acrylic emulsion (A). The amount of the carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) is preferably from about 1 to about 40 mg KOH / g, and more preferably from about 5 to about 30 mg KOH / g, as the solid content acid value of the core-shell acrylic emulsion (B). The amount is within the range. The said range is preferable from a viewpoint of the water resistance of the colored coating film formed from the water-based colored coating composition of this invention, and the finishing property of a colored coating film.

In the core-shell type acrylic emulsion (B), the carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) may be contained as a monomer unit of the core part, may be contained as a monomer unit of the shell part, or Although it may be contained as a monomer unit of both the core part and the shell part, it is preferably contained as a monomer unit of the shell part. This is because the storage stability of the core-shell type acrylic emulsion (B), the finish of the colored coating film formed by the aqueous colored coating composition of the present invention, and the water adhesion resistance are excellent.

The core-shell type acrylic emulsion (B) desirably contains a hydroxyl group-containing polymerizable unsaturated monomer (b ₃ ) as a monomer unit from the viewpoint of storage stability of the base coating material (I). Examples of the hydroxyl group-containing polymerizable unsaturated monomer (b ₃ ) include the same hydroxyl group-containing polymerizable unsaturated monomer (a ₃ ). The amount of the hydroxyl group-containing polymerizable unsaturated monomer (b ₃ ) is preferably from about 1 to about 100 mgKOH / g, and more preferably from about 10 to about 50 mgKOH / g, as the solid content hydroxyl value of the core-shell acrylic emulsion (B). The amount is within the range. The said range is suitable from the point of the water resistance and finishing property of the colored coating film formed from the water-based coloring coating composition of this invention.

The hydroxyl group-containing polymerizable unsaturated monomer (b ₃ ) may be included as a monomer unit of the core portion, a monomer unit of the shell portion, or a core in the core-shell type acrylic emulsion (B). It may be included as both monomer units and shell units.

Further, the core-shell acrylic emulsion (B), from the viewpoint of improving water resistance of the coating film formed, as monomer units, preferably contains a polyvinyl compound (b _4). Examples of the polyvinyl compound (b ₄ ) include the same compounds as the other vinyl compounds (a ₄ ). The ratio of the polyvinyl compound (b ₄ ) is preferably about 0.1 to about 3% by mass, and more preferably about 0.1 to about 3% by mass, based on the total amount of all monomer units of the core-shell type acrylic emulsion (B). It is in the range of about 2% by weight.

In the core-shell type acrylic emulsion (B), the polyvinyl compound (b ₄ ) may be contained as a monomer unit of the core part, may be contained as a monomer unit of the shell part, or the core part and the shell part. These may be contained as both monomer units, but are preferably contained as monomer units in the core portion. This is because the storage stability and production stability of the core-shell type acrylic emulsion (B), and the sharpening property of the colored coating film formed by the aqueous colored coating composition of the present invention are excellent.

When the core-shell type acrylic emulsion (B) has a carboxyl group by including a carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) as a monomer unit, the carboxyl group is neutralized with a neutralizing agent. can do. There is no restriction | limiting in particular as said neutralizing agent, The compound listed by the term of a core-shell type acrylic emulsion (A) can be mentioned.

The core-shell acrylic emulsion (B) preferably has a glass transition temperature in the range of about −60 to about 0 ° C., and more preferably about −50 to about −10 ° C.
Since the water-based colored coating composition of the present invention contains the core-shell type acrylic emulsion (B) and the urethane resin emulsion (C) described later, it is possible to achieve both the hardness and water resistance of the formed colored coating film. It is considered.

<Urethane resin emulsion (C)>
As the urethane resin emulsion (C), those usually used as urethane resin emulsions in this technical field can be used without particular limitation.
The urethane resin emulsion (C) preferably has an average particle size in the range of about 0.01 to about 1.0 μm, and more preferably about 0.01 to about 0.5 μm.

  The urethane resin emulsion (C) can be obtained, for example, by dispersing a urethane prepolymer produced by reacting a polyisocyanate, a polyol and a carboxyl group-containing diol in water in the presence of a desired chain extender.

  Examples of the polyisocyanate include aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate; burette type adducts, isocyanurate ring adducts of these diisocyanate compounds; isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or 2,6-) diisocyanate, 1,3- (or 1,4-) di (isocyanatomethyl) cyclohexane, 1,4- Cycloaliphatic diisocyanate compounds such as cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexane diisocyanate; these diisocyanates Burette type adducts, isocyanurate ring adducts; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1, 4-naphthalene diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether isocyanate, (m- or p-) phenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethyl-4,4 ′ -Aromatic diisocyanate compounds such as biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenylisocyanate); Burette type adduct of isocyanate compound, isocyanurate cycloadduct; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanate Polyisocyanate compounds having three or more isocyanate groups in one molecule such as natotoluene, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate; burette type of these polyisocyanate compounds Adducts, isocyanurate cycloadducts; ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexanetriol and other isocyanate groups in excess of hydroxyl groups By ratio Urethane adducts obtained by reacting polyisocyanate compounds; bullet type adducts of these urethanized adducts, isocyanurate ring adducts, and the like.

Examples of the polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, polyoctamethylene ether glycol; dicarboxylic acid (adipine) Acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycol (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1 , 5-pentanediol, neopentyl glycol, bishydroxymethylcyclohexane, etc.), for example, polyols produced by polycondensation such as polyethylene adipate, poly Polyester polyols such as tylene adipate, polyhexamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, polyneopentyl / hexyl adipate; polycaprolactone polyol, poly-3-methylvalerolactone polyol; Polycarbonate polyol: ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, tricyclodecane dimethylol, hydrogenated bisphenol A, low molecular weight glycols such as cyclohexanedimethanol and 1,6-hexanediol; The combination of the Luo and the like.
As the polyol, polycarbonate polyol is preferable from the viewpoint of the hardness and water resistance of the colored coating film formed from the aqueous colored coating composition of the present invention.

  Examples of the polycarbonate polyol include those obtained by reacting a carbonate with a polyol, and those obtained by reacting phosgene with bisphenol A and the like.

  Examples of the carbonate ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like. On the other hand, examples of the polyol capable of reacting with the carbonate ester include ethylene glycol, diethylene glycol, Triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1 , 0-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propane Diol, 2-methyl-1,8-octanediol, 2-butyl-2-ethylpropanediol, 2-methyl-1,8-octanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexane Dihydroxy compounds such as dimethanol, hydroquinone, resorcin, bisphenol-A, bisphenol-F, 4,4′-biphenol, polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene adipate, polyhexamethy Nsakushineto, polyester polyols such as polycaprolactone and the like.

  Examples of the carboxyl group-containing diol include dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutyric acid, and the like. From the viewpoint of the hardness and water resistance of the colored coating film formed from the aqueous colored coating composition of the present invention. Dimethylolpropionic acid is preferred.

  Further, as the above-mentioned desired chain extender, conventionally known ones such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4 '-Dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, polyoxyethylenediamine, polyoxypropylenediamine, amine-terminated polyoxyethylene-polyoxypropylene copolymer Diamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine, tetraethylenepentamine, etc .; hydroxyethylhydrazine, hydroxyethyldiethylenetriamine, 2-[(2-aminoethyl) Amino] ethanol, the compound having an amino group and a hydroxyl group such as 3-amino-propanediol; hydrazine, it may be mentioned acid hydrazides, and the like.

  When a urethane resin emulsion (C) contains a carboxyl group etc., it can neutralize with a neutralizing agent. There is no restriction | limiting in particular as said neutralizing agent, What was listed by the term of the core-shell type acrylic emulsion (A) is mentioned.

<Acrylic pigment dispersion resin (D)>
Examples of the acrylic pigment-dispersed resin (D) include an acrylic resin obtained by polymerizing a polymerizable unsaturated monomer with a polymerization initiator in the presence of a hydrophilic organic solvent.

Examples of the polymerizable unsaturated monomer include the compounds listed in the section of the core-shell acrylic emulsion (A), which can be used in appropriate combination.
The acrylic pigment-dispersed resin (D) is preferably a resin that can be dissolved or dispersed in water, specifically, preferably about 10 to about 100 mg KOH / g, and more preferably about 20 to It has a hydroxyl value of about 70 mg KOH / g, and preferably an acid number of about 10 to about 80 mg KOH / g, and more preferably about 20 to about 60 mg KOH / g.

  Examples of the hydrophilic organic solvent used for polymerization include alcohol organic solvents such as methanol, ethanol, isopropanol, n-butanol and isobutanol; ether organic solvents such as dioxane and tetrahydrofuran; ethylene glycol monomethyl ether and ethylene glycol. Ethylene glycol ether organic solvents such as monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono tert-butyl ether; diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether, Diethylene glycol ether organic solvents such as ethylene glycol monoisopropyl ether, diethylene glycol mono n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono tert-butyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene Propylene glycol ether organic solvents such as glycol monoisopropyl ether; Dipropylene glycol ether organic solvents such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono n-propyl ether, dipropylene glycol monoisopropyl ether ;vinegar Ethyl, butyl acetate, isobutyl acetate, 3-ester organic solvents such as methoxybutyl acetate, and combinations thereof.

Examples of the polymerization initiator include compounds listed in the section of the core-shell type acrylic emulsion (A).
Moreover, when acrylic pigment dispersion resin (D) has a carboxyl group, it is preferable to neutralize the said carboxyl group with a neutralizing agent. The neutralizing agent is not particularly limited as long as it can neutralize a carboxyl group, and examples thereof include compounds listed in the section of the core-shell type acrylic emulsion (A).
The acrylic pigment dispersion resin (D) preferably has a weight average molecular weight in the range of about 1000 to about 100,000, and more preferably about 8,000 to about 70,000.

  In the present specification, the number average molecular weight and the weight average molecular weight mean values obtained by converting the molecular weight measured with a gel permeation chromatograph (“HLC8120GPC” manufactured by Tosoh Corporation) based on the molecular weight of polystyrene. . For the measurement, “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation) The measurement is performed under the conditions of mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 cc / min, detector: RI.

The water-based colored coating composition of the present invention is based on the total solid content of the core-shell type acrylic emulsion (A), the core-shell type acrylic emulsion (B), the urethane resin emulsion (C), and the acrylic pigment dispersion resin (D). ,
The core-shell type acrylic emulsion (A) is preferably about 5 to about 70% by mass, and more preferably about 7 to about 61% by mass in terms of solid content.
The core-shell type acrylic emulsion (B) is preferably about 20 to about 85% by mass, and more preferably about 25 to about 79% by mass,
Preferably, the urethane resin emulsion (C) is solids, preferably about 5 to about 70% by weight, and more preferably about 7 to about 61% by weight, and the acrylic pigment dispersion resin (D) is preferably solids. Comprises from about 5 to about 70 weight percent, and more preferably from about 7 to about 61 weight percent. The above range is preferable from the viewpoints of the storage stability of the base coating material (I), the finish of the colored coating film formed using the colored coating composition of the present invention, the water resistance, the sharpening property, and the like.

<Coloring pigment (E)>
The water-based colored paint composition of the present invention can exhibit its effect to the maximum when it is an enamel paint containing the color pigment (E), and the color pigment (E) is included in the base paint (I). Is done. As the color pigment (E), those usually used in the paint field are not particularly limited, and various color pigments can be used according to the purpose.

  Specific examples of the color pigment (E) include metallic pigments such as aluminum powder, bronze powder, copper powder, tin powder, lead powder, zinc powder, iron phosphide; pearl-like metal-coated mica powder, mica-like iron oxide, etc. Pearl pigments; white pigments such as titanium oxide; black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, iron black, aniline black; yellow iron oxide, titanium yellow, monoazo yellow, condensed azo yellow, azomethine Yellow pigments such as yellow, bismuth vanadate, benzimidazolone, isoindolinone, isoindoline, quinophthalone, benzidine yellow, permanent yellow; orange pigments such as permanent orange; red iron oxide, naphthol AS azo red, ansanthrone, anthrac Nonyl red, perylene mar Red pigments such as cobalt red, quinacridone violet and dioxazine violet; blue pigments such as cobalt blue, phthalocyanine blue and selenium blue; phthalocyanine And green pigments such as green.

  In the present invention, the colored pigment (E) is mixed with the base paint (I) in a state of being dispersed by the acrylic pigment-dispersed resin (D), and the amount of the colored pigment (E) varies depending on the type of pigment. However, in general, it is preferably about 0.1 to about 300 parts by weight, and more preferably about 1 to about 150 parts by weight with respect to 100 parts by weight of the solid content of the resin component contained in the base paint (I). Within the range of the part.

  The base paint (I) may be an extender pigment, a thickener, an organic solvent, an ultraviolet absorber, a light stabilizer, a surface conditioner, polymer fine particles, a dispersion aid, a basic neutralizer, a preservative, if desired. Other components usually used in water-based paints such as an antifoaming agent and a curing catalyst can be included.

<Diluent (II)>
In the present invention, the diluent (II) gives the base coating (I) a wide range of workability by diluting the base coating (I), generally just before coating, and also provides the colored coating of the present invention. It is a component which can improve the water resistance of the colored coating film formed with a composition.

  Diluent (II) contains a carbodiimide compound and water. The carbodiimide compound preferably has two or more carbodiimide groups in the molecule and has water solubility or water dispersibility. Also, the carbodiimide compound preferably has a carbodiimide equivalent in the range of about 100 to about 800, and more preferably about 200 to about 600.

  The carbodiimide compound can be produced, or a commercially available product can be used as it is, and specific examples of commercially available products include, for example, “Carbodilite V-02”, “Carbodilite V-04”, “Carbodilite V-06” “Carbodilite E-01”, “Carbodilite E-04” (trade name, manufactured by Nisshinbo Co., Ltd.) and the like can be mentioned. These may be used alone or in a mixture of two or more.

  Diluent (II) is preferably about 0.1 to about 20% by mass, more preferably about 1 from the viewpoint of the finish of the colored coating film formed from the aqueous colored coating composition of the present invention. In the range of about 10% by mass.

Diluent (II) is for paints usually contained in water-based paints such as organic solvents, UV absorbers, light stabilizers, basic neutralizers, preservatives, antifoaming agents, surface conditioners, curing catalysts, etc., if desired. Other components such as additives can be further included.
The water-based colored coating composition of the present invention can be a two-pack type coating composed of a base coating (I) and a diluent (II).

The aqueous coloring paint composition of the present invention can be easily prepared by mixing the base paint (I) and the diluent (II) immediately before painting.
In the water-based colored coating composition of the present invention, the ratio of the base coating (I) and the diluent (II) can be appropriately adjusted depending on the coating environment and the like. For example, the diluent (II) is used in the base coating (I). Preferably, it may be included in the range of about 5 to about 100 parts by weight, and more preferably about 10 to about 60 parts by weight with respect to 100 parts by weight of the solid content. The said range is preferable from a viewpoint of the finish of the colored coating film formed from the water-based coloring coating composition of this invention, water resistance, and coating workability | operativity.

  Further, the equivalent ratio of the carbodiimide group contained in the diluent (II) to the carboxyl group contained in the base paint (I) is preferably about 0.1 to about 1.5, and more preferably about 0.1 to 0.1. Within the range of about 1.0 equivalent. The said range is preferable from a water-resistant viewpoint of the colored coating film formed from the water-based coloring coating composition of invention.

  Examples of the object to be coated with the aqueous colored coating composition of the present invention include iron, aluminum, brass, copper plate, stainless steel plate, tin plate, galvanized steel plate, alloyed zinc (Zn-Al, Zn-Ni, Zn-Fe, etc.) Metals such as plated steel sheets; Surface-treated metals obtained by subjecting these metal surfaces to chemical conversion treatment such as zinc phosphate treatment and chromate treatment; Surfaces of materials to be coated such as plastic, wood, concrete, mortar, etc. Examples of the material surface to be coated include a primer or the like undercoating, intermediate coating, overcoating, or clear coating.

  Spray coating, electrostatic coating, brush coating, roller coating, and the like can be used without particular limitation as a coating means for the water-based colored coating composition of the present invention. Further, the drying method of the water-based colored coating composition of the present invention is not particularly limited, and normal temperature drying, forced drying, and heat drying can be used. The effect is high under dry conditions.

After the water-based colored coating composition of the present invention is applied to the object to be coated to form a colored coating film, a top clear coating may be applied thereon to form a clear coating film.
Prior to applying the top clear coating, the colored coating formed from the aqueous colored coating composition of the present invention may be cured and dried, or the top clear coating is applied over the uncured colored coating, Both coatings can also be dried.

  As the above-mentioned top clear coating, conventionally known ones can be used without particular limitation, for example, acrylic resins containing a crosslinkable functional group such as a hydroxyl group, fluororesins, etc., main ingredients such as block polyisocyanates, polyisocyanates, melamine resins, etc. Two-part curable paints using a curing agent, lacquer paints mainly composed of cellulose acetate butyrate-modified acrylic resin, and the like. In particular, a coating containing a polyisocyanate curing agent is obtained by transferring a part of the polyisocyanate curing agent from a top clear coating to a colored coating formed from an aqueous colored coating composition, and the hydroxyl group in the colored coating. And the adhesion between the colored coating film and the top clear coating film, water adhesion resistance, and the like can be improved.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples. In the following examples, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

<Manufacture of core-shell type acrylic emulsion (A)>
[Production Example 1]
In a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device, 65 parts of deionized water and “Newcol 562SF” (trade name, anionic emulsifier, non-volatile content 60%, manufactured by Nippon Emulsifier Co., Ltd.) 0.5 part was added, stirred in a nitrogen stream and heated to 85 ° C. Next, 80 parts of the following monomer mixture (1), 1.6 parts of “Newcol 562SF”, 1.6 parts of monomer emulsion consisting of 55 parts of deionized water, and 5.2 parts of 3% ammonium persulfate aqueous solution were introduced into the reaction vessel. And held at 85 ° C. for 15 minutes. Next, the remaining monomer emulsion was added dropwise to the reaction vessel with a metering pump over 3 hours, and aged for 1 hour after completion of the addition. Next, a monomer emulsion comprising 20 parts of the following monomer mixture (2), 0.5 part of “Newcol 562SF”, 13 parts of deionized water, and 3 parts of a 0.7% ammonium persulfate aqueous solution was added to the reaction vessel over 2 hours. It was dripped in. Next, 43 parts of 0.5% aqueous dimethylethanolamine solution was added to the reaction vessel, cooled to 30 ° C., filtered through a 100 mesh nylon cloth, and an acid value of 16 mg KOH / g, hydroxyl value of 21 mg KOH / g, glass transition A core-shell acrylic emulsion (A-1) having a temperature of 15.9 ° C., an average particle size of 130 nm, and a non-volatile content of 35.4% was obtained.

[Monomer mixture (1)]
Methyl methacrylate 36 parts Ethyl acrylate 20 parts n-Butyl acrylate 19.8 parts Hydroxyethyl methacrylate 4 parts Allyl methacrylate 0.2 parts

[Monomer mixture (2)]
Methyl methacrylate 5.5 parts ethyl acrylate 10 parts n-butyl acrylate 1 part hydroxyl ethyl methacrylate 1 part methacrylic acid 2.5 parts

[Production Example 2]
In the same manner as in Production Example 1 except that the monomer mixture (1) and the monomer mixture (2) were changed to the following monomer mixture (3) and monomer mixture (4), respectively, an acid value of 16 mgKOH / g, a hydroxyl value of 21 mgKOH / g, a core-shell acrylic emulsion (A-2) having a glass transition temperature of 23 ° C., an average particle diameter of 150 nm, and a non-volatile content of 35.4% was obtained.

[Monomer mixture (3)]
Methyl methacrylate 40 parts Ethyl acrylate 22 parts n-Butyl acrylate 13.8 parts Hydroxyethyl methacrylate 4 parts Allyl methacrylate 0.2 parts

[Monomer mixture (4)]
Methyl methacrylate 5.5 parts ethyl acrylate 10 parts n-butyl acrylate 1 part hydroxyl ethyl methacrylate 1 part methacrylic acid 2.5 parts

<Manufacture of core-shell type acrylic emulsion (B)>
[Production Example 3]
Into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device, 65 parts of deionized water and 0.5 part of “Newcol 562SF” are added and stirred in a nitrogen stream to 85 ° C. The temperature rose. Next, 4 parts of a monomer emulsion consisting of 70 parts of the following monomer mixture (5), 1.6 parts of “Newcol 562SF” and 55 parts of deionized water, and 5.2 parts of 3% aqueous ammonium persulfate solution were introduced into the reaction vessel. And held at 85 ° C. for 15 minutes. Next, the remaining monomer emulsion was added dropwise to the reaction vessel with a metering pump over 3 hours, and aged for 1 hour after completion of the addition. Next, a monomer emulsion comprising 30 parts of the following monomer mixture (6), 0.5 part of “Newcol 562SF”, 13 parts of deionized water, and 3 parts of a 0.7% ammonium persulfate aqueous solution was added to the reaction vessel over 2 hours. It was dripped in. Next, 43 parts of 0.5% aqueous dimethylethanolamine solution was added to the reaction vessel, cooled to 30 ° C., filtered through a 100 mesh nylon cloth, and an acid value of 9.8 mg KOH / g, hydroxyl value of 21 mg KOH / g, A core-shell acrylic emulsion (B-1) having a glass transition temperature of −42 ° C., an average particle size of 120 nm, and a non-volatile content of 35.2% was obtained.

[Monomer mixture (5)]
n-butyl acrylate 35 parts 2-ethylhexyl acrylate 27 parts styrene 4 parts hydroxyethyl methacrylate 3.5 parts allyl methacrylate 0.5 parts

[Monomer mixture (6)]
n-butyl acrylate 8 parts 2-ethylhexyl acrylate 17 parts styrene 2 parts hydroxyethyl methacrylate 1.5 parts methacrylic acid 1.5 parts

[Production Example 4]
The acid value of 19.5 mgKOH / g, the hydroxyl value was the same as in Production Example 3 except that the monomer mixture (5) and the monomer mixture (6) were changed to the monomer mixture (7) and the monomer mixture (8), respectively. A core-shell acrylic emulsion (B-2) having 21 mg KOH / g, a glass transition temperature of −35 ° C., an average particle diameter of 140 nm, and a non-volatile content of 35.2% was obtained.

[Monomer mixture (7)]
n-butyl acrylate 35 parts 2-ethylhexyl acrylate 27 parts styrene 4 parts hydroxyethyl methacrylate 3.5 parts allyl methacrylate 0.5 parts

[Monomer mixture (8)]
n-butyl acrylate 5 parts 2-ethylhexyl acrylate 18.5 parts styrene 2 parts hydroxyethyl methacrylate 1.5 parts methacrylic acid 3.0 parts

[Production Example 5]
An acid value of 19.5 mgKOH / g, a hydroxyl value was obtained in the same manner as in Production Example 3 except that the monomer mixture (5) and the monomer mixture (6) were changed to the monomer mixture (9) and the monomer mixture (10), respectively. A core-shell acrylic emulsion (B-3) having 21 mg KOH / g, glass transition temperature of −24 ° C., average particle size of 120 nm, and nonvolatile content of 35.2% was obtained.

[Monomer mixture (9)]
Methyl methacrylate 10 parts n-butyl acrylate 25 parts 2-ethylhexyl acrylate 27 parts Styrene 4 parts Hydroxyethyl methacrylate 3.5 parts Allyl methacrylate 0.5 parts

[Monomer mixture (10)]
n-butyl acrylate 5.0 parts 2-ethylhexyl acrylate 18.5 parts styrene 2 parts hydroxyethyl methacrylate 1.5 parts methacrylic acid 3.0 parts

<Manufacture of single layer type acrylic emulsion for comparative example>
[Production Example 6]
In a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device, 80 parts of deionized water and 0.5 part of “Newcol 562SF” are added, stirred in a nitrogen stream, and heated to 85 ° C. Warm up. Next, 4 parts of a monomer emulsion consisting of 100 parts of the following monomer mixture (11), 1.6 parts of “Newcol 562SF” and 55 parts of deionized water, and 5.2 parts of 3% aqueous ammonium persulfate solution were introduced into the reaction vessel. And held at 85 ° C. for 15 minutes. Next, the remaining monomer emulsion was added dropwise to the reaction vessel with a metering pump over 3 hours, and aged for 1 hour after completion of the addition. Next, 43 parts of 0.5% aqueous dimethylethanolamine solution was added to the reaction vessel, cooled to 30 ° C., filtered through a 100 mesh nylon cloth, and an acid value of 9.8 mg KOH / g, hydroxyl value of 21 mg KOH / g, A single-layer acrylic emulsion having a glass transition temperature of −42 ° C., an average particle size of 120 nm, and a non-volatile content of 35.2% was obtained.

[Monomer mixture (11)]
n-butyl acrylate 43.5 parts 2-ethylhexyl acrylate 44 parts styrene 6 parts hydroxyethyl methacrylate 5 parts methacrylic acid 1.5 parts

<Manufacture of urethane resin emulsion (C)>
[Production Example 7]
1,6 hexanediol polycarbonate polyol (number average molecular weight 1000) 52.0 parts, trimethylolpropane 2.5 parts, 1,4-butanediol 1.0 part, dimethylolpropionic acid 4.1 parts, and isophorone 33.9 parts of diisocyanate was reacted in methyl ethyl ketone as a reaction solvent using dibutyltin dilaurate as a catalyst, and then 0.8 part of triethylamine was added and reacted to synthesize a urethane prepolymer. The amount of free isocyanate groups in the urethane prepolymer was 2.1%. Next, 3.1 parts of triethylamine was added to the urethane prepolymer for neutralization, and then 250 parts of distilled water was added to the urethane prepolymer and emulsified while stirring at high speed using a homomixer. Subsequently, the urethane resin emulsion (C-1) was obtained by collect | recovering the methyl ethyl ketone which is a reaction solvent under reduced pressure using an evaporator.

[Production Example 8]
A urethane resin emulsion (C-2) was obtained in the same manner as in Production Example 7 except that the polycarbonate polyol was changed to polyethylene glycol having a number average molecular weight of 1000.

<Production of pigment dispersion resin solution>
[Production Example 9]
750 parts of ethylene glycol-n monobutyl ether was added to the reaction vessel, and the temperature was raised to 115 ° C. in a nitrogen stream. After the temperature of the reaction vessel reached 115 ° C., the following monomer mixture (12) was added to the reaction vessel over 3 hours and aged for 2 hours. After completion of the reaction, the product was neutralized with dimethylethanolamine in an equivalent amount, and further 250 parts of ethylene glycol-n monobutyl ether was added to give a yellow liquid pigment dispersion resin (D-1) solution (solid content 50%). Got. The acid value of the pigment dispersion resin (D-1) was 31 mgKOH / g, the hydroxyl value was 42 mgKOH / g, and the weight average molecular weight was 45,000.

[Monomer mixture (12)]
Methyl methacrylate 200 parts n-Butyl acrylate 200 parts Isobornyl acrylate 300 parts Styrene 110 parts Hydroxyethyl acrylate 50 parts Acrylic acid 40 parts "NF biisomer S20W" (Note 1) 200 parts Azobisisobutyronitrile 10 parts

(Note 1) “NF biisomer S20W”: trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., methoxypolyethylene glycol methacrylate (compound containing a 45-mer of oxyethylene groups in the molecule and having a methoxy group at the end), Active ingredient 50%, molecular weight 2080.

[Production Example 10]
To the reaction vessel, 550 parts of propylene glycol mono n-propyl ether was added, and the temperature was raised to 115 ° C. in a nitrogen stream. After the temperature of the reaction vessel reached 115 ° C., 350 parts of methyl methacrylate, 200 parts of n-butyl acrylate, 250 parts of 2-ethylhexyl methacrylate, 130 parts of 4-hydroxybutyl acrylate, 60 parts of acrylic acid, and “light ester PM” (Note 2) A monomer mixture in which 10 parts of azobisisobutyronitrile was dissolved in 10 parts was added to the vessel over 3 hours and aged for 2 hours. After completion of the reaction, the product was neutralized with dimethylethanolamine in an equivalent amount, 450 parts of propylene glycol mono n-propyl ether was added, and the pH was adjusted to 7.5 with dimethylethanolamine, and the pigment dispersion was a yellow liquid. A solution (solid content 55%) of resin (D-2) was obtained. The weight average molecular weight of the pigment dispersion resin (D-2) was 45,000, the acid value was 47 mgKOH / g, and the hydroxyl value was 51 mgKOH / g.

(Note 2) “Light Ester PM”: trade name, manufactured by Kyoeisha Chemical Co., Ltd., (2-methacryloyloxyethyl) acid phosphate.

<Manufacture of aluminum pigment paste>
[Production Example 11]
To the container, 48.1 parts of aluminum pigment paste “WJE7640” (manufactured by Toyo Aluminum Co., Ltd., metal content 52%), 35 parts of ethylene glycol monobutyl ether, and 3 parts of a phosphate group-containing resin solution (Note 3) are added. By mixing, an aluminum pigment paste was obtained.

(Note 3) Phosphate group-containing resin solution: A solvent consisting of 27.5 parts of methoxypropanol and 27.5 parts of isobutanol is placed in a 4 liter flask equipped with a stirrer, a temperature controller and a refrigerator. Heated to ℃, then, 25 parts of styrene, 27.5 parts of n-butyl methacrylate, 20 parts of “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), 7.5 parts of hydroxybutyl acrylate, phosphate group-containing polymerizable monomer (Note 4) 121.5 parts of a mixture comprising 15 parts, 12.5 parts of 2-methacryloyloxyethyl acid phosphate, 10 parts of isobutanol, and 4 parts of t-butylperoxyoctanoate was added to the above solvent over 4 hours. To a mixture of 0.5 parts t-butylperoxyoctanoate and 20 parts isopropanol. It was added dropwise over between, then by aging for 1 hour with stirring to give a solid content of 50% phosphoric acid group-containing resin solution.

(Note 4) Phosphoric acid group-containing polymerizable monomer: 57.5 parts of monobutyl phosphoric acid and 41.1 parts of isobutanol are placed in a 4 liter flask, and 42.5 parts of glycidyl methacrylate are added dropwise over 2 hours under aeration. Then, the mixture was aged with stirring for 1 hour. Subsequently, 5.9 parts of isopropanol was added to obtain a phosphoric acid group-containing polymerizable monomer solution having a solid content of 50%.

<Manufacture of carbon black pigment paste>
[Production Example 12]
In a container, 40 parts of deionized water, 10 parts of carbon black (“MONARCH 1300”, trade name, manufactured by Cabot Specialty Chemicals Inc.), and 36.3 of the pigment dispersion resin (D-2) solution obtained in Production Example 10 were obtained. Part was added, mixed with a disper for 15 minutes, and then dispersed with a “Scan Dix” (trade name, manufactured by LAU-Disperser Orwell Co., Ltd.) for 30 minutes to obtain a carbon black pigment paste.

<Manufacture of water-based colored paint composition (metallic color)>
[Example 1]
In a container, 86.1 parts of aluminum pigment paste obtained in Production Example 11 (25 parts of aluminum pigment), 40 parts of pigment-dispersed resin solution (D-1) obtained in Production Example 9 (20 parts of solid content), And dispersed for 1 hour, 43 parts of core-shell acrylic emulsion (A-1) (solid content 15 parts), 114 parts of core-shell acrylic emulsion (B-1) (solid content 40 parts), urethane resin emulsion (D -1) 89 parts (solid content 25 parts) and urethane associative thickener 2 parts were added to the vessel, stirred for an additional hour, adjusted to pH 8.0 with dimethylethanolamine, and 20% solids By adding deionized water so as to obtain a metallic base material. Addition of 40 parts of diluent containing 5% of “Carbodilite SV02” (trade name, manufactured by Nisshinbo Co., Ltd., carbodiimide compound, solid content 40%, carbodiimide equivalent 429 per solid content) and water 95% to 100 parts of the above main agent As a result, a metallic water-based colored coating composition was obtained.

[Examples 2 to 8 and Comparative Examples 2 to 4]
An aqueous colored coating composition was produced in the same manner as in Example 1 except that the resin and pigment were as shown in Table 1 or Table 3. In addition, the resin amount of Table 1 and Table 3 means solid content, and the quantity of an aluminum pigment means the mass of the aluminum pigment with respect to PHR, ie, 100 mass parts of resin solid content contained in a base coating material.

[Comparative Example 1]
Example 1 except that the diluent was changed to a diluent containing 5% "Baihijole VPLS2319" (trade name, manufactured by Sumitomo Bayer Urethane Co., Ltd., light yellow transparent liquid water-dispersible polyisocyanate) and 95 parts of water. In the same manner, an aqueous colored coating composition was produced.

<Manufacture of water-based colored paint composition (black paint color)>
[Example 9]
To the container, 86.3 parts of carbon black pigment paste obtained in Production Example 12 (10 parts of carbon black) was added and stirred for 10 minutes, and then 43 parts of core-shell acrylic emulsion (A-1) (solid content) 15 parts), 114 parts of core-shell type acrylic emulsion (B-1) (solid content 40 parts), 89 parts of urethane resin emulsion (D-1) (solid content 25 parts), and 2 parts of urethane associative thickener The mixture was further stirred for 1 hour, adjusted to pH 8.0 with dimethylethanolamine, and deionized water was added so as to have a solid content of 20%, thereby obtaining a black paint base. 40 parts of a diluent containing 5 parts of “Carbodilite SV-02” and 95 parts of water was added to 100 parts of the above main agent to obtain a black-based aqueous colored coating composition.

[Examples 10 to 16 and Comparative Example 5]
A black-based aqueous colored coating composition was produced in the same manner as in Example 9 except that the resin and pigment were as shown in Table 2 or Table 3. In Tables 2 and 3, the amount of the carbon black pigment means PHR as in the case of the aluminum pigment.

<Performance evaluation>
The aqueous coloring coating compositions obtained in Examples 1 to 16 and Comparative Examples 1 to 5 were evaluated with respect to the following performance. The results are also shown in Tables 1 to 3.

[Mixability]
A diluent is added to a metallic paint base agent or a black paint base agent, and after mixing for 1 minute by hand stirring, the state of the paint is evaluated based on the following criteria.
A: The main agent and the diluent are uniformly mixed. ×: The main agent and the diluent are not uniformly mixed and are partially non-uniform.

[Finishability]
A base plate is prepared by polishing the surface of the clear coating film of the coated plate, which has been formed in order for undercoat, intermediate coating and topcoat clear for automobile body, with # 800 water-resistant paper and then degreasing. The aqueous colored coating composition produced in Examples 1 to 16 and Comparative Examples 1 to 5 is applied to the base plate in four stages under conditions of 25 ° C. and relative humidity of 40%. Between each stage, hot air of 50 ° C was blown to each test plate at 10 m / sec with a hot air generator, and the surface was dried to the touch dry state. Finally, the base coat with a dry film thickness of 15 μm Get. Next, 100 parts of “Letane PG Multiclear HX (Q)” (trade name, manufactured by Kansai Paint Co., Ltd., clear paint containing hydroxyl group-containing acrylic resin) is added to “Letane PG Multiclear Standard Curing Agent” (trade name, Kansai Paint Co., Ltd.). A top clear coating material prepared by mixing 50 parts of hexamethylene diisocyanate isocyanurate type polyisocyanate curing agent) immediately before coating is air spray-coated on the base coat so as to have a dry film thickness of 40 μm, and then a dryer. A test coating plate is obtained by forcibly drying for 20 minutes so that the temperature of the base plate is kept at 60 ° C. Based on the following evaluation criteria, the coating surface of the test coating plate obtained in this way is visually evaluated, aluminum orientation for the metallic coating test plate, and jetness for the black coating test plate. evaluate.

[Aluminum orientation]
A: The aluminum pigment is oriented in a parallel and uniform manner with respect to the coating surface, and no metallic unevenness is observed. ○: The aluminum pigment is oriented in a parallel and uniform manner with respect to the coating surface, but a slight amount of metallic unevenness is observed. △: Many metallic unevenness is recognized ×: Very much metallic unevenness is recognized

[Blackness]
◎: Jetness is very good ○: Jetness is good △: Jetness is insufficient ×: Jetness is poor and slight white blur is observed

[Storage]
Based on the following evaluation criteria, the state of the paint after enclosing the water-based colored paint composition obtained in Examples 1 to 16 and Comparative Examples 1 to 5 in a 250 mL glass bottle and storing at 40 ° C. for 1 month. evaluate.
◎: No change is observed in the paint ○: Slight settling is observed in the paint, but it returns to its original state when lightly stirred. △: Settling is observed in the paint, and it does not return to its original state when lightly stirred. : Sedimentation is noticeable

[Adhesiveness]
The test coated plate obtained in the above evaluation of the finishing property is cut with a cutter so as to reach the substrate, 100 100 mm 1 mm × 1 mm goblets are formed, and an adhesive tape is attached to the surface, and then 20 The remaining number of goby-like coatings after the tape is abruptly peeled at ℃ is examined.
◎: 100 pieces of Goban-like coating film remain ○: 90-99 pieces of Goban-like coating film remain Δ: 41-89 pieces of Goban-like coating film remain × : 40 or less gob-like coatings remain

[water resistant]
The test coated plate obtained in the evaluation of the finish is immersed in 40 ° C. warm water for 10 days, and the coated surface is visually evaluated.
◎: There is no abnormality on the coated surface and it is very good. ○: There is almost no abnormality on the coated surface and it is good. △: Slight whitening is observed on the coated surface. ×: Swelling, whitening, etc. on the coated surface. Abnormalities are observed

[Center sharpening]
The base coat formed in the evaluation of the finish is left in a laboratory at about 20 ° C. for 2 hours, and then the surface of the base coat is reciprocated 5 times while applying a load of 50 g / cm ² using P800 abrasive paper. Grind. Based on the following criteria, how the scratches enter the surface of the base coat and the state of adhesion of the coating film to the abrasive paper are evaluated.
A: No deep scratches are observed on the surface of the base coat, and no coating film is adhered to the abrasive paper. O: Slight scratches are observed on the surface of the base coat, and many coating films are adhered to the abrasive paper. Deep scratches are observed on the surface of the base coat, and many coating films adhere to the abrasive paper. ×: Many deep scratches are observed on the surface of the base coat, and many coating films adhere to the abrasive paper.

Claims (8)

An aqueous coloring coating composition comprising a base coating (I) and a diluent (II),
The base paint (I) contains a core-shell acrylic emulsion (A), a core-shell acrylic emulsion (B), a urethane resin emulsion (C), an acrylic pigment dispersion resin (D), and a colored pigment (E).
The core part and / or the shell part of the core-shell type acrylic emulsion (A) contains methyl (meth) acrylate and / or ethyl (meth) acrylate (a ₁ ) as monomer units, and methyl (meth) acrylate and / or ethyl. The proportion of (meth) acrylate (a ₁ ) is 40% by mass or more of the total monomer units of the core-shell type acrylic emulsion (A),
The core part and / or shell part of the core-shell type acrylic emulsion (B) contains, as a monomer unit, a linear or branched hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) having 6 or more carbon atoms, The proportion of the hydrocarbon group-containing polymerizable unsaturated monomer (b ₁ ) is 20 to 80% by mass of the total monomer units of the core-shell type acrylic emulsion (B), and methyl (meth) acrylate and / or ethyl (meth). The proportion of acrylate (a ₁ ) is less than 40% by mass of the total monomer units of the core-shell acrylic emulsion (B),
Diluent (II) comprises a carbodiimide compound and water,
An aqueous coloring paint composition characterized by the above. In the core-shell type acrylic emulsion (A), the carboxyl group-containing polymerizable unsaturated monomer (a ₂ ) is used as a monomer unit, and the solid content acid value of the core-shell type acrylic emulsion (A) is in the range of 5 to 40 mgKOH / g. The water-based colored coating composition of claim 1 further comprising such an amount. In the core-shell type acrylic emulsion (B), the carboxyl group-containing polymerizable unsaturated monomer (b ₂ ) is used as a monomer unit, and the solid content acid value of the core-shell type acrylic emulsion (B) is in the range of 1 to 40 mgKOH / g. The aqueous coloring coating composition according to claim 1 or 2, further comprising such an amount. The water-based colored coating composition according to any one of claims 1 to 3, wherein the core-shell type acrylic emulsion (B) has a glass transition temperature in the range of -60 to 0 ° C. Based on the total solid mass of the core-shell acrylic emulsion (A), core-shell acrylic emulsion (B), urethane resin emulsion (C), and acrylic pigment dispersion resin (D),
The core-shell type acrylic emulsion (A) is 5 to 70% by mass in solid content,
The core-shell type acrylic emulsion (B) is 20 to 85% by mass in solid content,
The urethane resin emulsion (C) is 5 to 70% by mass in solid content,
Acrylic pigment-dispersed resin (D) in a solid content of 5 to 70% by mass,
The aqueous coloring coating composition as described in any one of Claims 1-4 containing. The aqueous coloring coating composition as described in any one of Claims 1-5 in which diluent (II) contains a carbodiimide compound in 0.1-20 mass%. The said water-based coloring coating composition contains diluent (II) in the range of 5-100 mass parts with respect to 100 mass parts of solid content of a base coating material (I). The water-based colored coating composition described in 1. The equivalent ratio of the carbodiimide group contained in the diluent (II) to the carboxyl group contained in the base paint (I) is in the range of 0.1 to 1.5. The water-based colored coating composition described in 1.