JP5979746B2 - Multi-component water-based base coat coating composition - Google Patents

Description

  The present invention relates to a multi-component aqueous colored base coat coating composition.

  In recent years, market development of water-based coloring base coating compositions has been activated in fields such as automobiles and automobile repair coatings.

  The coating appearance of water-based coloring base paint compositions is easily affected by the temperature and humidity of the coating environment, especially when metallic pigments are included, the degree of unevenness of the coating film, the feeling of glitter, and the feeling of particles depend on the coating environment. It is widely known that it is difficult to obtain a stable finished appearance.

  Patent Document 1 discloses that a metallic paint is obtained by forming a water-based paint composition including a base paint composition containing a resin, a pigment, a thickener and water, and a diluent containing water and a thickener. However, it is described that the finished appearance of the coating film formed is good and is not greatly affected by the coating environment.

  Patent Document 2 discloses an aqueous coating composition comprising a special effect pigment-containing composition containing a water-dilutable resin, and a composition containing an inorganic layered silicate, a water-dilutable polyurethane resin and water and containing no pigment. It is described that the composition allows the rheological properties of the aqueous coating composition to have adequate sag resistance.

  Patent Document 3 includes an aqueous coating, a special effect pigment, a water-dilutable binder, an organic solvent, water and a water-soluble special effect module containing water and a lacquer additive, a water-dilutable polyurethane binder, water, an organic solvent and a lacquer additive. It is described that efficient production and storage can be achieved by comprising the binder module.

  In this way, the water-based coloring base coating composition is composed of a multi-component system, and a component for adding a water-dilutable binder such as a thickener or polyurethane to a diluent for adjusting the viscosity of the coating. The use of is a known technique.

  On the other hand, Patent Document 4 discloses an aqueous coating composition containing a water-dispersible acrylic polymer (A), an aqueous urethane resin (B) and an anionic core-shell resin dispersion (C). Describes that it is possible to form a coating film having high hiding power and excellent adhesion, water resistance, and intermediate sharpening properties.

  By the way, the purpose of automotive repair painting is to make the repair coating part the same finish as the old paint film on the automobile body. In order to apply repair painting to the finished automobile body, parts such as equipment inside the body It cannot be dried at high temperatures so as not to be affected. In addition, the paint environment differs greatly depending on each repair coating site compared to the industrial coating line being stable within the control range, so the water-based coloring base paint composition that gives a finished appearance that is satisfactory at all repair coating sites It is extremely difficult to design things.

  From this point, the solid content of the water-based base paint composition used for painting is lowered and the coating is divided into 4-5 times, and air blow (compressed with an air spray or the like on each coated surface) The coating film is dried by lightly blowing air) to increase the viscosity of the coating film to suppress sagging of the coating film, and the same paint is applied to the coating film to form a colored base coating film. In fact, shortening or omitting the air blowing process is required to improve work efficiency.

  However, when the same paint is applied by continuous coating, that is, wet-on-wet without performing an air blowing process using a composition as described in Patent Documents 1 to 4, the coating film formed is Sagging and unevenness may not occur to form a uniform coating film, and swelling may occur after the coating film is immersed in water, and sufficient coating film performance may not be obtained.

JP 2006-70095 A JP 2001-316612 A JP-A-6-340830 JP 2010-037516 A

  An object of the present invention is to provide a multi-component aqueous colored base coat coating composition which has a very good sagging resistance and gives a colored base coating film having a stable finished appearance and excellent coating film properties.

As a result of intensive studies on the above-mentioned problems, the inventors of the present invention prepared an aqueous colored base coat coating composition by diluting water with a main component (I) containing a water-dilutable urethane resin, a pigment and a polyacrylic acid-based thickener. It has been found that the sagging resistance during coating is greatly improved by dividing it into a viscosity modifier component (II) containing a water-soluble acrylic resin and a urethane-associative viscosity modifier. The membrane performance was obtained and the present invention was reached.
That is, the present invention
1.
A multi-component aqueous colored basecoat coating composition for preparing an aqueous colored basecoat coating composition by mixing two or more components before coating,
The water-dilutable resin component (A), the pigment (B), the polyacrylic acid viscosity modifier (C) having an active ingredient acid value of 80 to 280 mgKOH / g, and water, and the water-dilutable resin component (A) The water-dilutable urethane resin as a part of the component contains 40% by mass or more in the solid content of the component (A), and the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) is water-dilutable. A main ingredient component (I) in the range of 0.01 to 5.0% by mass relative to the solid content of the resin component (A);
Water-dilutable resin component (D), urethane-associative viscosity modifier (E) (excluding the water-dilutable urethane resin) and water, and water-dilutable resin component (D) is diluted with water as part of the components sexual acrylic resin (d1) with a solid content viewed contains more than 50 wt% in the (the polyacrylic acid viscosity modifier (C) excluding) (D) component solids, or does not contain water-dilutable urethane resins, Viscosity modifier component (II) containing water-dilutable urethane resin in component (D) solid content of less than 40% by mass in solid content ,
A multi-component water-based base coat composition comprising a combination of
2.
The water- reducible resin component (A) in the main component (I) is a water-soluble acrylic resin having a solid content acid value of 10 to 70 mgKOH / g in addition to the water-dilutable urethane resin and an acrylic resin comprising the dispersion stabilizer as constituent components. 2. The multi-component aqueous colored base coat coating composition according to 1, further comprising an emulsion (excluding a water-soluble acrylic resin) ;
3.
The mass ratio of the main ingredient component (I) and the viscosity modifier component (II) is in the range of 40 to 95 parts by mass of component (I) and 5 to 60 parts by mass of component (II) based on 100 parts by mass in total. The multi-component water-based base coat composition according to item 1 or 2,
4).
A multi-component system in which the viscosity modifier component (III) is further combined with the main component (I) and the viscosity modifier component (II), and the viscosity modifier component (III) is an inorganic viscosity modifier The multi-component aqueous colored base coat coating composition according to any one of items 1 to 3, which comprises (F) and water,
5.
5. The multi-component aqueous colored base coat coating composition according to item 4, wherein the viscosity modifier component (III) further comprises a water-dilutable resin component (G).
6).
The water-dilutable resin component (G) in the viscosity modifier component (III) contains a water-dilutable urethane resin as a part of the component, the multi-component aqueous colored base coat coating composition according to 5,
7).
The multi-component aqueous colored base coat coating composition according to any one of 4 to 6, wherein the viscosity modifier component (III) further comprises a pigment,
8).
The mass ratio of the main component (I), the viscosity modifier component (II) and the viscosity modifier component (III) is 30 to 80 parts by mass, and the component (II) is 30 to 80 parts by mass based on the total of 100 parts by mass. The multi-component water-based base coat composition according to any one of 4 to 7, wherein 1 to 40 parts by mass and component (III) are in the range of 0.5 to 50 parts by mass,
About.

  The aqueous colored base coat coating composition of the present invention comprises a main component (I) containing a water-dilutable urethane resin and a pigment, and a viscosity modifier component (II) containing a water-dilutable acrylic resin and a urethane-associative viscosity modifier. However, the mixing property between the two is good, and the water-based colored base coat coating composition prepared by mixing them can form a highly finished coating film with very good sagging resistance. . Further, the water-based colored base coat coating composition of the invention according to claim 4 can form a coating film with good mixing workability, good coating workability, sagging resistance, and high finished appearance.

  In addition, since the present water-based base coat coating composition has extremely good sagging resistance, the coating film can be applied at the time of coating even when the same coating is continuously applied by shortening or reducing the air blowing process between each coating. Without sagging, a highly finished appearance with almost no unevenness can be achieved, and the time and energy required to form the base coat film can be reduced.

  The aqueous colored base coat coating composition of the present invention is a combination of the main component (I) and the viscosity modifier component (II).

≪Main ingredient component (I) ≫
The main component (I) in the present invention includes a water-dilutable resin component (A), a pigment (B), a polyacrylic acid viscosity modifier (C) and water, and the water-dilutable resin component (A) is the component. As a part, the water-dilutable urethane resin contains 40% by mass or more in the solid content of the component (A), and the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) is the water-dilutable resin. It exists in the range of 0.01-5.0 mass% with respect to solid content of a component (A), It is characterized by the above-mentioned.

  In addition, in this specification, solid content means a non-volatile content, means the residue remove | excluding volatile components, such as water and an organic solvent, from a sample, and multiplies the mass of a sample by solid content concentration. Can be calculated. The solid content concentration can be measured by dividing the mass of a residue obtained by drying about 3 grams of a sample at 105 ° C. for 3 hours by the mass before drying, and it may be expressed as 100 fraction.

  Moreover, an active ingredient means the residue remove | excluding diluents, such as water and an organic solvent, from a sample.

<Water-dilutable resin component (A)>
The water-dilutable resin component (A) is not particularly limited as long as it is a resin component that can be diluted with water, and any conventionally known one can be used, such as a water-soluble, emulsion-type, or colloidal-dispersion type resin. Can be used without limitation. Examples of the resin species include acrylic resins, urethane resins, polyester resins, alkyd resins, silicone resins, cellulose resins, modified resins of these resins, and the like, and these may be used alone or in combination.

  In the present invention, the water-dilutable resin component (A) contained in the main component (I) is a water-dilutable urethane resin in a solid content of 40% by mass or more, preferably 45% by mass or more. It is characterized by including.

  When the content of the water-dilutable urethane resin is less than 40% by mass, the adhesion and water resistance of the base coat film formed from the aqueous colored base coat paint composition of the present invention are insufficient, and the base coat film is concealed. It is not preferable because the property tends to decrease.

  As such water-dilutable urethane resin, those known in the art can be used without limitation. For example, a urethane prepolymer obtained by reacting polyisocyanate, polyol and carboxyl group-containing diol is dispersed in water. Can be obtained.

  Examples of polyisocyanates include aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate; burette-type adducts and 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-cyclohexane diisocyanate Alicyclic diisocyanate compounds such as 1,3-cyclopentane diisocyanate and 1,2-cyclohexane diisocyanate; Turret type adduct, isocyanurate ring adduct; 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'-biphenylene diisocyanate, Aromatic diisocyanate compounds such as bis (4-isocyanatophenyl) sulfone and isopropylidenebis (4-phenylisocyanate); these diisocyanates -Burelet type adduct, isocyanurate ring adduct; triphenylmethane-4,4 ', 4 "-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-tri Polyisocyanate compounds having three or more isocyanate groups in one molecule such as isocyanatotoluene and 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; burettes of these polyisocyanate compounds Type 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 At a ratio of polyiso Urethane adduct obtained by reacting a Aneto compound; these urethane adducts of views - let type adducts can include an isocyanurate ring adducts.

  Examples of the polyol include those having a number average molecular weight in the range of 200 to 10,000, such as polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, Polyether polyols such as polyoctamethylene ether glycol; dicarboxylic acids (adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycols (ethylene glycol, propylene glycol, 1,4-butane) Diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, bishydroxymethylcyclohexane and the like) For example, polyester polyols such as polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, polyneopentyl / hexyl adipate; polycaprolactone polyol, poly-3- Methyl valerolactone polyol; polycarbonate polyol; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, tricyclodecandi Such as methylol, hydrogenated bisphenol A, cyclohexanedimethanol, 1,6 hexanediol, etc. Molecular weight glycols; and the like, may be used alone or in combination.

  Examples of the carboxyl group-containing diol include dimethylolacetic acid, dimethylolpropionic acid, and dimethylolbutyric acid.

  In the production of the urethane prepolymer, it is desirable that the mixing ratio of the above components is such that the equivalent ratio of isocyanate group / hydroxyl group is in the range of 1.1 to 1.9. The prepolymer synthesis reaction can be performed based on a conventionally known method.

  The water-dilutable urethane resin can be neutralized with a neutralizing agent. The neutralizing agent is not particularly limited as long as it can neutralize the carboxyl group. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol , Triethylamine, ammonia and the like.

  The water-dilutable urethane resin may be in a state dispersed in water, and the average particle size thereof may be in the range of 0.01 to 1 μm, particularly 0.1 to 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

  In the invention, the water-dilutable urethane resin has a solid content acid value of 5 to 100 mgKOH / g, preferably 10 to 70 mgKOH / g, from the viewpoint of storage stability of the main component (I). desirable.

  The water-reducible resin component (A) in the main component (I) preferably further contains a water-soluble acrylic resin and an acrylic resin emulsion in addition to the water-dilutable urethane resin.

  As the water-soluble acrylic resin, for example, a polymerizable unsaturated monomer component containing an acid group-containing polymerizable unsaturated monomer, a hydroxyl group-containing polymerizable unsaturated monomer, and other polymerizable unsaturated monomers, in the presence of a hydrophilic organic solvent. And a resin obtained by polymerizing with a polymerization initiator.

  Examples of the acid group-containing polymerizable unsaturated monomer include carboxyl group-containing polymerizable unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and β-carboxyethyl acrylate; 2-acrylamide-2- Sulfonic acid group-containing polymerizable unsaturated monomers such as methylpropanesulfonic acid, allylsulfonic acid, styrenesulfonic acid sodium salt, sulfoethyl methacrylate and its sodium salt and ammonium salt; 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl Examples thereof include phosphoric acid group-containing polymerizable unsaturated monomers such as acid phosphate, 2-acryloyloxypropyl acid phosphate, and 2-methacryloyloxypropyl acid phosphate. It can be used in combination or more.

  Examples of the hydroxyl group-containing polymerizable unsaturated monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and the like having 2 to 2 carbon atoms. Eight hydroxyalkyl (meth) acrylates; N-methylolacrylamide; allyl alcohol; ε-caprolactone-modified acrylic monomers of hydroxyalkyl (meth) acrylates having 2 to 8 carbon atoms; diethylene glycol (meth) acrylate, triethylene glycol (meta ) Acrylate, polyethylene glycol (meth) acrylate, dipropylene glycol (meth) acrylate, tripropylene glycol (meth) acrylate, polypropylene glycol (meth) Acrylates, polyalkylene glycol (meth) acrylate and polyethylene polypropylene glycol (meth) acrylate and the like, which may be used in combination one or more.

  Examples of the other polymerizable unsaturated monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, and iso-butyl. (Meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate (Lauryl (meth) acrylate), tridecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate Alkyl, cycloalkyl (meth) acrylates such as benzoate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate; Aromatic ring-containing polymerizable unsaturated monomers such as benzyl (meth) acrylate, styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meta ) Polymerizable unsaturated monomer having an alkoxysilyl group such as acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane; perfluorobutylethyl (meth) acrylate, Perfluoroalkyl (meth) acrylates such as fluorooctylethyl (meth) acrylate; Polymerizable unsaturated monomers having fluorinated alkyl groups such as fluoroolefins; Polymerizable unsaturated monomers having photopolymerizable functional groups such as maleimide groups Vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate; allyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethanedi (meta ) Acrylate, 1,1,1-trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl terephthalate, divinylbenzene, etc. Polymerizable unsaturated monomer having at least two saturated groups in one molecule; (meth) acrylonitrile, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) a Relate, N, N-dimethylaminopropyl (meth) acrylamide, nitrogen-containing polymerizable unsaturated monomers such as adducts of glycidyl (meth) acrylate and amines; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate Epoxy group-containing polymerizable unsaturated monomers such as 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether Isocyanato group-containing polymerizable unsaturated monomer such as 2-isocyanatoethyl (meth) acrylate and m-isopropenyl-α, α-dimethylbenzyl isocyanate; has a polyoxyethylene chain whose molecular terminal is an alkoxy group (me ) Acrylate; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone), etc. And carbonyl group-containing polymerizable unsaturated monomers. These polymerizable unsaturated monomers can be used alone or in combination of two or more.

  The water-soluble acrylic resin is preferably neutralized with a neutralizing agent for the purpose of improving the water solubility of the resin and improving the finished appearance of the aqueous colored base coat coating composition of the present invention. The neutralizing agent is not particularly limited as long as it can neutralize an acid group. Examples thereof include sodium hydroxide, potassium hydroxide; trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol, Examples include amine compounds such as triethylamine; ammonia water.

  The water-soluble acrylic resin generally has a solid content acid value of 5 to 100 mgKOH / g, preferably 10 to 70 mgKOH / g, a solid content hydroxyl value of 10 to 150 mgKOH / g, preferably 20 to 100 mgKOH / g, and a weight average molecular weight. Is in the range of 5,000 to 10,000, preferably 8,000 to 70,000.

  In this specification, the weight average molecular weight is a value obtained by converting the weight average molecular weight measured by gel permeation chromatograph (“HLC8120GPC” manufactured by Tosoh Corporation) based on the weight average molecular weight of polystyrene. Columns are “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation, trade names) ), Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 ml / min, detector: RI.

  The number average molecular weight is a value obtained by converting the number average molecular weight measured with a gel permeation chromatograph (“HLC8120GPC” manufactured by Tosoh Corporation) based on the number average molecular weight of polystyrene. Columns are “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation, trade names) ), Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 ml / min, detector: RI.

  The hydrophilic organic solvent used in the polymerization is not strictly distinguished, but examples thereof include organic solvents that dissolve at least 20 g in 100 g of water at 20 ° C., and specifically include methanol, ethanol, isopropanol. Alcohol organic solvents such as n-butanol and isobutanol; ether organic solvents such as dioxane and tetrahydrofuran; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, ethylene Ethylene glycol ether organic solvents such as glycol mono n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono tert-butyl ether; diethylene Diethylene glycol ether organic solvents such as recall monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether, diethylene 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 ether organic solvents such as propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether; dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono -Dipropylene glycol ether organic solvents such as propyl ether and dipropylene glycol monoisopropyl ether; and ester organic solvents such as ethyl acetate, butyl acetate, isobutyl acetate, and 3-methoxybutyl acetate. Two or more types can be used in combination.

  As the polymerization initiator, conventionally known ones can be used without limitation, and examples thereof include cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (tert-butylperoxide). Oxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, cumene hydroperoxide, 2 , 5-dimethylhexane-2,5-dihydroperoxide, 1,3-bis (tert-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) ) Hexane, diisopropylbenzene peroxide, tert-butylcumyl peroxide Decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, di-tert-amyl peroxide, bis (tert-butylcyclohexyl) peroxydicarbonate, tert-butylperoxybenzoate Peroxide polymerization initiators such as 2,5-dimethyl-2,5-di (benzoylperoxy) hexane and tert-butylperoxy-2-ethylhexanoate; 2,2′-azobis (isobutyrate) Nitrile), 2,2′-azobis-2-methylbutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), azocumene, 2,2′-azobis (2-methylbutyronitrile), 2,2'-azobis-2,4-dimethylvaleronitrile, 4,4'-azobis (4-cyanovaleric acid 2- (t-butylazo) -2-cyanopropane, 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), 2,2′-azobis [2-Methyl-N- (2-hydroxyethyl) -propionamide], dimethyl 2,2′-azobis (2-methylpropionate), 1,1′-azobis (1-cyclohexane-1-carbonitrile) Azo polymerization initiators such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and dimethyl-2,2′-azobisisobutyrate.

  The acrylic resin emulsion is other than the water-soluble acrylic resin, and is obtained, for example, by emulsion polymerization of a polymerizable unsaturated monomer component in one stage or in multiple stages in the presence of water and a dispersion stabilizer. Can be preferably used.

  Examples of the polymerizable unsaturated monomer component include the same as those exemplified in the description of the water-soluble acrylic resin. When emulsion polymerization is performed in multiple stages, the monomer composition and the polymerizable monomer used at that stage are used. The proportion of the total amount used can be adjusted as appropriate.

  In addition, the dispersion stabilizer used when the acrylic resin emulsion is emulsion-polymerized is not particularly limited. For example, sodium dialkylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, polyoxyethylene alkylphenyl ether Anionic emulsifiers such as sodium sulfate and sodium alkyldiphenyl ether disulfonate, nonionic emulsifiers such as polyoxyethylene higher alcohol ether and polyoxyethylene alkylphenyl ether, and anionic or cationic reactive emulsifiers having radically polymerizable double bonds Can be mentioned.

  A reactive emulsifier is an emulsifier having both a nonionic group, an anionic group and a cationic group in the molecule and a polymerizable unsaturated group. Specific examples of the polymerizable unsaturated group include: (Meth) allyl group, (meth) acryloyl group, propenyl group, butenyl group etc. are mentioned. Commercially available products include “Latemuru” (trade name, manufactured by Kao Corporation), “Eleminol” (trade name, manufactured by Sanyo Chemical Co., Ltd.), “Aquaron” (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), “Adekaria soap” (trade name, manufactured by Asahi Denka Co., Ltd.), “ANTOX” (trade name, manufactured by Nippon Emulsifier Co., Ltd.) and the like can be mentioned.

  In the present invention, the acrylic resin emulsion contained in the main component (I) is a monolayer type obtained by emulsion polymerization of a polymerizable unsaturated monomer component in one step in the presence of water and an emulsifier, preferably a reactive emulsifier. It is desirable to use an acrylic resin emulsion from the viewpoint of the film-forming property of the base coat film and the adhesion after water immersion.

  Examples of the polymerizable unsaturated monomer that is polymerized into the single-layer acrylic resin emulsion include an acid group-containing polymerizable unsaturated monomer, a hydroxyl group-containing polymerizable unsaturated monomer, and a linear or branched carbon atom having 6 or more carbon atoms. It is suitable to contain a hydrogen group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers.

  Examples of the acid group-containing polymerizable unsaturated monomer and the hydroxyl group-containing polymerizable unsaturated monomer include the same compounds as those described above.

  Moreover, as a linear or branched hydrocarbon group-containing polymerizable unsaturated monomer having 6 or more carbon atoms, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl ( (Meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), etc. are used, and these are used alone or in combination of two or more. can do.

  The ratio of the water-soluble acrylic resin and the acrylic resin emulsion used in the water-dilutable resin component (A) is 10/90 to 80/20, preferably 25/75, in terms of a water-soluble acrylic resin / acrylic resin emulsion solid content mass ratio. A range of ˜60 / 40 is suitable from the viewpoint of the storage stability of the main component (I), the finished appearance of the base coating film obtained by continuous coating, and water resistance.

<Pigment (B)>
In the present invention, conventionally known pigments (B) contained in the main component (I) can be used without particular limitation. Specific examples thereof include metal oxide pigments such as titanium oxide and iron oxide, composite metal oxide pigments such as titanium yellow, carbon black, azo pigments, quinacridone pigments, diketopyrrolopyrrole pigments, perylene pigments, and perinones. Pigments, benzimidazolone pigments, isoindoline pigments, isoindolinone pigments, metal chelate azo pigments, phthalocyanine pigments, indanthrone pigments, dioxane pigments, indigo pigments, etc .; aluminum (evaporation) (Including aluminum), copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, mica coated with titanium oxide or iron oxide, glass flake, hologram pigment, etc. Pigments: clay, kaolin, barium sulfate, barium carbonate, potassium carbonate Siumu, talc, silica, extender pigments such as alumina white; and the like. These may be used alone or in combination depending on the color or coating film performance and its object.

  Further, when the glitter pigment is used, its shape is not particularly limited. For example, a flake shape is preferable, and it is hydrogen that it is dispersed and coated with a treatment agent containing a phosphate group or a sulfonate group. This is preferable from the viewpoint of suppressing gas generation. Conventionally known low molecular weight compounds and copolymers can be applied to the phosphoric acid group or sulfonic acid group-containing treatment agent without any particular limitation.

  The blending amount of the pigment (B) varies depending on the pigment used depending on the intended coating color, but is generally 0.1 to 300 mass with respect to 100 mass parts of the total solid content of the resin contained in the main component (I). It is preferably within the range of parts, more preferably within the range of 0.5 to 200 parts by weight from the viewpoint of paint stability. The blending method of the pigment (B) into the main component (I) is not particularly defined, but when the main component (I) contains a water-soluble acrylic resin, the pigment (B), the resin and water are added in advance. A pigment dispersion may be prepared by mixing, and the pigment dispersion may be mixed with other components and blended with the main component (I).

<Polyacrylic acid viscosity modifier (C)>
In the present invention, the main component (I) can be stably stored, and the aqueous colored base coat coating composition obtained by mixing with the viscosity modifier component (II) has a good finished appearance with no occurrence of unevenness or sagging. The main component (I) contains a polyacrylic acid viscosity modifier (C) as a viscosity modifier so that a film can be formed. Examples of the polyacrylic acid viscosity modifier (C) include polyacrylic acid soda, polyacrylic acid- (meth) acrylic acid ester copolymer, and the like.

  The active ingredient acid value of the polyacrylic acid viscosity modifier can be in the range of 30 to 300 mg / KOH, preferably 80 to 280 mg / KOH. Commercially available products include, for example, “Primal ASE60”, “Primal TT615”, “Primal RM5” (trade name) manufactured by Rohm and Haas, “SN thickener 613”, “SN thickener 618”, “manufactured by San Nopco” SN thickener 630 "," SN thickener 634 "," SN thickener 636 "(above, trade name) and the like.

  In the present invention, the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) contained in the main component (I) is 0.01 to 5.0 with respect to the solid content of the water-dilutable resin component (A). It is within the range of mass%, and preferably within the range of 1.0 to 4.5 mass%. When the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) is less than 0.01% by mass, the storage stability of the main ingredient component (I) and the air blowing process between each coating of the aqueous colored base coat paint composition are shortened. Alternatively, the sagging resistance when the coating is continuously reduced is insufficient, and when the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) exceeds 5.0% by mass, the main ingredient component (I) and the below-mentioned This is not preferable because the mixing property with the viscosity modifier component (II) is insufficient, and the finished appearance of the resulting coating film, particularly unevenness when applied to a metallic paint, occurs.

  The main ingredient component (I) is a pigment dispersant, an ultraviolet absorber, a light stabilizer, polymer fine particles, a dispersion aid, an antiseptic, a silane coupling agent, an antifoaming agent, a curing catalyst, a polyacrylic acid viscosity modifier ( Other components such as paint additives usually used in the preparation of water-based paints such as known viscosity modifiers, organic solvents, and neutralizers other than C) may be included.

  The solid content concentration of the main component (I) is generally adjusted in the range of 15 to 50% by mass, preferably 20 to 40% by mass, from the viewpoint of coating workability and concealing property and finished appearance. Yes.

  The viscosity of the main component (I) is not particularly limited, but is 100 to 2000 mPa · sec from the viewpoint of storage stability and miscibility with the viscosity modifier component (II) described later, Preferably, it can be in the range of 600 to 2000 mPa · sec, more preferably in the range of 800 to 1600 mPa · sec. In the present specification, the viscosity is a value measured at a rotational speed of 60 rpm using a viscometer digital bismetholone viscometer VDA type (manufactured by Shibaura System Co., Ltd.) within 10 minutes after the sample is prepared at 25 ° C. To do.

≪Viscosity modifier component (II) ≫
In the present invention, the viscosity modifier component (II) includes a water-dilutable resin component (D), a urethane-associated viscosity modifier (E), and water.

  In the present invention, the rheological properties of the aqueous colored base coat coating composition can be controlled according to the coating environment by mixing the viscosity modifier component (II) with the main agent (I) immediately before coating, By configuring the colored base coat paint composition in this way, the base coating film that maintains the storage stability of each component and does not sag even when continuously applied, and has an excellent finished appearance without occurrence of unevenness. It can be formed.

<Water-dilutable resin component (D)>
The water-dilutable resin component (D) that can be contained in the viscosity modifier component (II) is appropriately selected from the compounds exemplified in the description of the water-dilutable resin component (A) contained in the main component (I). Can be used. Since the viscosity modifier component (II) includes the water-dilutable resin component (D), the mixing property with the main component (I) is good, and the base coat film formed from the aqueous colored base coat coating composition is uneven. It is possible to have a good finished appearance with little occurrence of.

  In the present invention, the water-dilutable resin component (A) contained in the main component (I) contains a water-dilutable urethane resin in the solid content of the component (A) in a solid content of 40% by mass or more. The water-reducible resin component (D) contained in the viscosity modifier component (II) contains the water-reducible acrylic resin (d1) as a part of the component in a solid content of 50% by mass or more in the solid content of the component (D). It is more preferable that it is 60 mass% or more.

  If the content of the water-dilutable acrylic resin (d1) is less than 50% by mass, unevenness or the like may occur in the base coat film, which is not preferable.

  In addition, in the viscosity modifier component (II), when the water-reducible resin component (D) contains a water-dilutable urethane resin, the solid content of the component (D) is less than 40% by mass, particularly 20% by mass. It is desirable to keep it below.

  The water-dilutable acrylic resin (d1) preferably contains a water-soluble acrylic resin as part of its components. By including a water-soluble acrylic resin, the viscosity of the viscosity modifier component (II) including the polyacrylic acid viscosity modifier is moderate without excessively increasing, and the mixing with the main component (I) is good. The resulting aqueous colored base coat coating composition is capable of forming a base coat film having almost no finished sagging and having an excellent finished appearance.

  As the water-soluble acrylic resin, conventionally known ones can be used without limitation, and can be appropriately selected from the water-soluble acrylic resins exemplified in the explanation of the main component (I), and the main component ( The water-soluble acrylic resin contained in I) and the viscosity modifier component (II) may be the same.

  As content of the water-soluble acrylic resin contained in the said water-dilutable acrylic resin (d1), it is 40 mass% or more by solid content in this (d1) solid content, Preferably it exists in the range of 45-95 mass%. It is desirable to be.

  The water-dilutable acrylic resin (d1) contained in the viscosity modifier component (II) preferably contains an acrylic resin emulsion as a part of the component.

  Conventionally known acrylic resin emulsions can be used without limitation, and can be used by appropriately selecting from the acrylic resin emulsions exemplified in the explanation of the main component (I). The acrylic resin emulsion contained in (I) and the viscosity modifier component (II) may be the same.

  In the present invention, the acrylic resin emulsion contained in the viscosity modifier component (II) has a solid content hydroxyl value of 40 mgKOH / g or less, particularly 20 mgKOH / g or less, more particularly 5 mgKOH / g or less, and a solid content acid value of A core-shell type acrylic resin emulsion in the range of 1 to 50 mgKOH / g, preferably 5 to 30 mgKOH / g is suitable.

  When the viscosity modifier component (II) contains the acrylic resin emulsion together with the urethane-associative viscosity modifier (E) described later, the mixing with the main agent (I) is good, and the aqueous colored base coat coating composition is continuous. In addition to good sagging resistance and finished appearance at the time of painting, it has the effect of improving the water resistance of the colored base coat film.

  Examples of the polymerizable unsaturated monomer used in the production of the acrylic resin emulsion include those described above, and suitable monomers include aromatic ring-containing polymerizable unsaturated monomers.

  Examples of the aromatic ring-containing polymerizable unsaturated monomer include styrene, α-methylstyrene, vinyltoluene and the like.

  In the core-shell type acrylic resin emulsion, the monomer component constituting the core part contains 15-80% by mass of an aromatic ring-containing polymerizable unsaturated monomer, and the aromatic ring-containing polymerizable unsaturated monomer contained in the core part Is more contained than the aromatic ring-containing polymerizable unsaturated monomer contained in the shell portion.

  Moreover, it is preferable that it is the range of 15-80 mass% as a total amount of the aromatic ring containing polymerizable unsaturated monomer contained in both a core part and a shell part.

  The blending ratio of the core part and the shell part is 5/95 to 95/5, preferably 10/90 to 90/10 in terms of the core part / shell part mass ratio.

  Examples of the dispersion stabilizer used for the polymerization of the core-shell type acrylic resin emulsion include those described above, but it is desirable to use a reactive emulsifier from the viewpoint of water resistance of the base coat film.

  The acrylic resin emulsion content contained in the water-dilutable acrylic resin (d1) is in the range of 1 to 60% by mass, preferably 5 to 55% by mass in terms of solid content in the (d1) solid content. Is desirable.

<Urethane associative viscosity modifier (E)>
In the present invention, the viscosity modifier component (II) contains a urethane-associative viscosity modifier (E). When the viscosity modifier component (II) contains the urethane-associative viscosity modifier (E), there is an effect of improving the sagging resistance of the aqueous colored base coat coating composition of the present invention.

  The urethane-associative viscosity modifier (E) is a compound having a hydrophobic group at the terminal and having a urethane bond in the molecular chain, and it is more preferable to use a urethane-associative viscosity modifier. A commercially available product can be used as the urethane-associative viscosity modifier. As commercial names of commercial products, for example, “UH-420”, “UH-462”, “UH-472”, “UH-540”, “UH-752”, “UH-756VF” manufactured by ADEKA, “ UH-814N ”(above, manufactured by Asahi Denka);“ SN thickener 612 ”,“ SN thickener 621N ”,“ SN thickener 625N ”,“ SN thickener 627N ”,“ SN thickener 660T ”(above, San Nopco) manufactured by San Nopco. Etc.).

  The effective component content of the urethane-associated viscosity modifier (E) in the viscosity modifier component (II) is 100 parts by mass of the water-dilutable resin component (D) solid content contained in the viscosity modifier component (II). It is suitable from the point of the sagging resistance at the time of the continuous coating of a base coat coating film, and a finished appearance that it exists in the range of 1-30 mass parts as a standard, Preferably it is 10-20 mass parts.

  The viscosity modifier component (II) is a pigment, a pigment dispersant, an ultraviolet absorber, a light stabilizer, polymer fine particles, a dispersion aid, an antiseptic, a silane coupling agent, an antifoaming agent, a curing catalyst, and a urethane-associated viscosity. Other components such as paint additives commonly used in the preparation of water-based paints such as known viscosity modifiers, organic solvents, and neutralizers other than the regulator (E) may be included.

  The solid content concentration of the viscosity modifier component (II) is generally in the range of 1 to 30% by mass, preferably 5 to 20% by mass, from the viewpoints of coating workability, concealment, and finished appearance. ing.

  Although it does not restrict | limit especially as a viscosity of the said viscosity modifier component (II), From the point of the storage stability of a viscosity modifier component (II), and a miscibility with a main ingredient component (I), 100-2000 mPa · Sec, preferably 300 to 1800 mPa · sec, more preferably 400 to 1600 mPa · sec.

≪Viscosity modifier component (III) ≫
The water-based colored base coat coating composition of the present invention is a multi-component system in which the viscosity modifier component (III) is further combined with the main component (I) and the viscosity modifier component (II), that is, a three-component system. You can also.

  By further combining the viscosity modifier component (III), the sagging resistance and finished appearance of the aqueous colored base coat coating composition can be improved, and the viscosity of the aqueous colored base coat coating composition can be adjusted moderately to facilitate painting. You can also.

  The viscosity modifier component (III) is a component having a composition different from that of the main component component (I) and the viscosity modifier component (II), and preferably contains an inorganic viscosity modifier (F) and water. .

<Inorganic viscosity modifier (F)>
As said inorganic type viscosity regulator (F), what is well-known in the said field | area can be used without a restriction | limiting, For example, a layered silicate mineral, a silica fine particle, etc. are mentioned, These are natural, a synthetic product, processing Any of the products may be used. Specific examples include montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, mica and bentonite. These may be diluted with a diluting medium such as an organic solvent or water.

  “Bentone 27”, “Bentone 34”, “Bentone 38”, “Bentone SD-1”, “Bentone SD-2”, “Bentone SD-3”, “Bentone 52”, “Bentone 57” (all above) (Rheox, trade name), “Tixogel VP”, “Tixogel TE”, “Tixogel UN”, “Tixogel EZ100”, “Tixogel MP100”, “Tixogel MP250” (all of which are made by Sud Chemical) , “Craytone 40”, “Craytone 34”, “Claytone HT”, “Claytone APA”, “Claytone AF”, “Claytone HY” (all of which are Southern) Clay Products, trade name), “Aerosil RX200”, “Aerosil R812”, “Aerosil R805”, “AerosilRY200”, “Aerosil R202” (all of which are product names of Nippon Aerosil Co., Ltd.), “Laponite RD” , “LaponiteRDS” (trade name, manufactured by Wilber Ellis).

  As the effective component content of the inorganic viscosity modifier (F) in the viscosity modifier component (III), when the viscosity modifier component (III) does not contain a water-dilutable resin component (G) described later, viscosity adjustment 0.1 to 3.0% by mass, preferably 0.3 to 2.0% by mass based on the mass of the agent component (III), and the viscosity modifier component (III) is a water-dilutable resin described later. When the component (G) is included, the effective component content of the inorganic viscosity modifier (F) in the viscosity modifier component (III) is 1 to 25 based on the solid content of the water-dilutable resin component (G). From the viewpoint of sagging resistance at the time of continuous coating of the aqueous colored base coat coating composition and finished appearance, it is preferably in the range of 3% by mass, preferably 3-20% by mass.

<Water-dilutable resin component (G)>
In the present invention, the viscosity modifier component (III) further contains a water-dilutable resin component (G). The film performance and sagging resistance such as water resistance, particularly sagging resistance at the time of continuous coating. To preferred.

  The water-dilutable resin component (G) contained in the viscosity modifier component (III) is not particularly limited, but examples thereof include the same compounds as those exemplified in the description of the water-dilutable resin component (A). it can.

  In the present invention, the water-reducible resin component (G) in the viscosity modifier component (III) preferably contains a water-dilutable urethane resin as a part of the component.

  When the viscosity modifier component (III) contains a water-dilutable urethane resin, the storage stability of the viscosity modifier (III) is good, regardless of the type of pigment contained in the main component (I). There is an effect that the sagging resistance at the time of continuous coating of the water-based base coat coating composition of the above coating color is stabilized.

  Such a water-dilutable urethane resin can be appropriately selected from those exemplified in the explanation of the main component (I), and is included in the main component (I) and the viscosity modifier component (III). The water-dilutable urethane resin may be the same.

  The content of the water-dilutable urethane resin contained in the water-dilutable resin component (G) is such that the solid content of the water-dilutable urethane resin is 40% by mass or more, preferably 50% by mass or more. It is desirable to be within the range.

  In addition, the viscosity modifier component (III) has an effect of improving sagging resistance, finished appearance and ease of spreading when continuously coating a water-based base coat coating composition, and also has an effect of concealing the coating film. Therefore, it is preferable that a pigment is included.

  As such pigments, conventionally known pigments can be used without limitation, and specifically, those described above as the pigment (B) can be exemplified.

  Among them, an extender pigment is used as the pigment because the mixing property with the main component (I) and the viscosity modifier component (II) is good without adversely affecting the color and orientation of the base coat film. It is preferable.

  The amount of the pigment used is 0.05 to 10% by mass based on the mass of the viscosity modifier component (III) when the viscosity modifier component (III) does not contain the water-dilutable resin component (G), preferably When the viscosity modifier component (III) contains a water-dilutable resin component (G) within the range of 0.05 to 5% by mass, the pigment content in the viscosity modifier component (III) is diluted with water. Of the water-based base coat coating composition is 0.5 to 100% by weight, preferably 0.5 to 50% by weight based on the solid content of the water-soluble resin component (G). It is preferable in terms of sagging properties, finished appearance, and concealment.

  The viscosity modifier component (III) can contain a polyol compound having a polyalkylene skeleton.

  Examples of the polyol compound having a polyalkylene skeleton include diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, polyethylene oxide, polypropylene oxide, and ethylene oxide / propylene. Polyalkylene polyol having at least one structure of block or random copolymerization of oxide; trimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, glycerin, polyglycerin, poly Polyalcohol such as tetramethylene glycol A polyhydric alcohol having a polyalkylene skeleton modified with lene; a condensation product of the polyalkylene polyol and a polybasic acid such as maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, adipic acid, isophthalic acid, etc. A certain polyester polyol; a caprolactone-modified polyol obtained by modifying a polyether polyol with caprolactone; and the like.

  The weight average molecular weight of the polyol compound having a polyalkylene skeleton is desirably in the range of 100 to 10,000, preferably 400 to 5,000.

  The amount of the polyol having a polyalkylene skeleton is 50 to 1000% by mass, preferably 100 to 100% by mass, based on the active ingredient mass of the inorganic viscosity modifier (F) contained in the viscosity modifier component (III). It is desirable that it is in the range of 500% by mass from the viewpoint of the finish of the coating film formed using the base coat coating composition of the present invention and the storage stability of the viscosity modifier component (III).

  The viscosity modifier component (III) is an ultraviolet absorber, light stabilizer, polymer fine particle, dispersion aid, preservative, silane coupling agent, antifoaming agent, curing catalyst, and inorganic viscosity modifier (F). It may contain other components such as known viscosity modifiers, organic solvents, neutralizers, and other paint additives that are usually used in preparing aqueous paints.

  From the viewpoint of coating workability and concealment, and finished appearance, the solid content concentration of the viscosity modifier component (III) is generally adjusted within the range of 1 to 30% by mass, preferably 5 to 20% by mass. Is suitable.

  The viscosity of the viscosity modifier component (III) is not particularly limited, but from the viewpoint of the storage stability of the viscosity modifier component (III) and the coating workability of the aqueous colored base coat coating composition. It can be in the range of 10 to 2000 mPa · sec, preferably 10 to 1000 mPa · sec, more preferably 10 to 600 mPa · sec.

≪Water-based base coat paint composition≫
In the present invention, the main ingredient component (I), the viscosity modifier component (II), and the viscosity modifier component (III) used as necessary are stored separately, and the painter can use each component immediately before painting. The aqueous colored base coat coating composition of the present invention can be prepared by stirring and mixing, and adjusting the viscosity with a diluent such as water as necessary. In the present specification, the term “immediately before painting” cannot be generally defined by a painter or a painting site, but can include, for example, up to three hours before painting.

The mass ratio of the main component (I) and the viscosity modifier component (II) in the aqueous colored base coat coating composition can be appropriately adjusted depending on the coating environment and the like, but in general, the component (I) is based on a total of 100 parts by mass. 40-95 parts by mass, preferably 45-90 parts by mass, component (II) in the range of 5-60 parts by mass, preferably 10-55 parts by mass, or main component (I), viscosity modifier component (II) In general, the mass ratio of the viscosity modifier component (III) is 30 to 80 parts by mass, preferably 35 to 70 parts by mass, and 1 to 40 parts (II) based on 100 parts by mass in total. The coating film concealing property and the finished appearance at the time of continuous coating are in the range of 5 parts by mass, preferably 5 to 30 parts by mass, and 0.5 to 50 parts by mass, preferably 5 to 35 parts by mass of component (III). And sagging resistance It is suitable, et al.

  In the present invention, if necessary, a curing agent such as a polyisocyanate curing agent, a blocked isocyanate curing agent, a melamine curing agent, an oxazoline curing agent, a carbodiimide curing agent is used as the main component (I), viscosity modifier component (II) and It can be included in any of the viscosity modifier components (III) or used as a separate component.

  The solid content concentration of the aqueous colored base coat coating composition of the present invention obtained as described above is generally in the range of 10 to 40% by mass, preferably 15 to 35% by mass, and the coating workability and concealability, and the finish. Suitable from the viewpoint of appearance.

  The viscosity of the aqueous colored base coat coating composition during coating is not particularly limited, but the coating workability is within the range of 160 to 600 mPa · sec, preferably 200 to 500 mPa · sec. It is good and suitable from the viewpoint of sagging resistance and continuous appearance during continuous coating.

≪Painting≫
The water-based colored base coat coating composition of the present invention can be applied by known coating means such as spray coating, electrostatic coating, brush coating, roller coating, etc., but spray coating can be performed from the viewpoint of the finished appearance of the coating film. preferable.

  The number of times of painting may be one, but it is desirable to coat the same paint a plurality of times, for example, 3 to 6 times in order to achieve both the finished appearance and the concealment.

  In the present invention, it is possible to have a good finished appearance without sagging the coating film even if the coating is continuously performed by omitting the air blow process performed between each coating in the case of repeated coating. If necessary, a process such as flash-off (after coating is allowed to stand at room temperature), air blowing or preheating may be provided between the coatings.

  Drying after the application of the aqueous colored base coat coating composition is not particularly limited, and may be in an undried state when the top clear described below is applied repeatedly. Preferably, it is preferably dried at a temperature of 40 to 100 ° C. for 5 to 60 minutes. The film thickness can be appropriately adjusted according to the state of the surface to be coated, but generally a dry film thickness of 5 to 100 μm, particularly 10 to 60 μm is suitable.

  As the coated surface to be applied, a conventionally known substrate surface and a coating surface provided on the substrate can be exemplified, and the substrate is not particularly limited. Metals such as aluminum; Organic base materials such as plastics; Inorganic base materials such as concrete and wood; and the coating film provided on the base material is not particularly limited. A multilayer coating film formed from a base coating film and a top clear coating film formed from a colored base coating composition, and a primer coating film, an electrodeposition coating film, an intermediate coating film under the base coating film. A coating film such as a film may be appropriately provided.

  Moreover, you may use the aqueous | water-based coloring basecoat coating material composition of this invention as a coating material for repair with respect to the coating film already formed in the said to-be-coated surface. In this case, the surface to be coated can be previously treated with a putty, a primer surfacer or the like. In addition, after applying the aqueous colored base coat coating composition, a top clear coating may be applied on the coating film.

  As such a top clear coating, conventionally known ones can be used without any particular limitation. For example, acrylic resins or fluororesins containing a crosslinkable functional group such as a hydroxyl group are used as the main ingredients, and block polyisocyanates, polyisocyanates, melamine resins, etc. are cured. A curable paint contained as an agent or a lacquer paint mainly composed of cellulose acetate butyrate-modified acrylic resin can be suitably used. Further, if necessary, pigments, fiber derivatives, additive resins, UV absorbers Further, paint additives such as a light stabilizer, a surface conditioner, and a curing catalyst can be contained.

  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, “part” and “%” mean “part by mass” and “% by mass”, respectively.

<Manufacture of water-dilutable urethane resin>
Production Example 1
In a reaction vessel, number average molecular weight 2000, 115.5 parts of polybutylene adipate having hydroxyl groups at both ends, number average molecular weight 2000, polycaprolactone diol having hydroxyl groups at both ends, 115.5 parts, dimethylolpropionic acid 23.2 parts. Then, 6.5 parts of 1,4-butanediol and 120.1 parts of isophorone diisocyanate were charged and reacted under stirring in a nitrogen stream at 85 ° C. for 7 hours to obtain a prepolymer having an NCO content of 4.0%. Next, the prepolymer was cooled to 50 ° C., and 165 parts of acetone was added and dissolved uniformly. Then, 15.7 parts of triethylamine was added with stirring, and 600 parts of deionized water was added while maintaining the temperature at 50 ° C. or lower. After maintaining the aqueous dispersion at 50 ° C. for 2 hours to complete the chain extension reaction, acetone was distilled off at 70 ° C. or lower under reduced pressure, the pH was adjusted to 8.0 with triethylamine and deionized water, and solid acid A urethane resin emulsion (A-1) having a value of 26 mgKOH / g and a solid content concentration of 30% was obtained.

<Manufacture of water-soluble acrylic resin>
Production Example 2
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 1) 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, and 450 parts of propylene glycol mono-n-propyl ether was added, and the pH was adjusted to 7.5 with dimethylethanolamine. A solution of acrylic resin (B-1) (solid content 55%) was obtained. The water-soluble acrylic resin (B-1) had a weight average molecular weight of 45,000, a solid content acid value of 47 mgKOH / g, and a solid content hydroxyl value of 51 mgKOH / g.
(Note 1) “Light Ester PM”: trade name, manufactured by Kyoeisha Chemical Co., Ltd., (2-methacryloyloxyethyl) acid phosphate.

Production Example 3
In Production Example 2, the monomer composition is the same as Production Example 2 except that the monomer composition is 360 parts of methyl methacrylate, 200 parts of n-butyl acrylate, 250 parts of 2-ethylhexyl methacrylate, 130 parts of 4-hydroxybutyl acrylate, and 60 parts of acrylic acid. Thus, a water-soluble acrylic resin (B-2) was obtained.

<Manufacture of acrylic resin emulsion>
Production Example 4
In a reaction vessel, 100 parts of deionized water, “ADEKA rear soap SR-1025” (trade name, manufactured by Asahi Denka Co., Ltd., reactive emulsifier, solid content 25%) and a monomer mixture (styrene 9 parts, n-butyl) 1 part of 40 parts of acrylate, 40 parts of 2-ethylhexyl acrylate, 10 parts of hydroxyethyl acrylate, 1 part of methacrylic acid) was added and stirred and mixed in a nitrogen stream, and 3 parts of 3% ammonium persulfate was added at 60 ° C. Next, the temperature was raised to 80 ° C., and a pre-emulsion comprising the remaining 99 parts of the monomer mixture, 2.5 parts of “Adeka Aria Soap SR-1025”, 4 parts of 3% ammonium persulfate and 100 parts of deionized water was added for 4 hours. The mixture was added to the reaction vessel using a metering pump, and aged for 1 hour after completion of the addition. Thereafter, 33 parts of deionized water was added and adjusted to pH 7.5 with dimethylethanolamine to obtain an acrylic resin emulsion (C-1) having an average particle size of 0.1 μm and a solid content concentration of 30%.

Production Example 5
To the reaction vessel, 300 parts of deionized water and 8 parts of “ADEKA rear soap SR-1025” were added, and the temperature was raised to 85 ° C. after purging with nitrogen. To this, 0.8 part of ammonium persulfate and 3.5% of a pre-emulsion obtained by emulsifying the following composition (A) were added, and after 20 minutes from the addition, the rest of the pre-emulsion was added dropwise over 170 minutes.
<Core component (A)>
Deionized water 365.5 parts Styrene 392.4 parts n-Butyl acrylate 130 parts 2-Ethylhexyl acrylate 32 parts Methacrylic acid 5.6 parts "SR-1025" 31.4 parts Ammonium persulfate 1.12 parts 1 hour after completion of dropping After aging, a pre-emulsion formed by emulsifying the following (B) composition was added dropwise over 70 minutes.
<Shell component (B)>
Deionized water 156.6 parts Styrene 20 parts γ-Methacryloyloxypropyltrimethoxysilane 25 parts n-butyl acrylate 25 parts 2-ethylhexyl acrylate 50 parts methacrylic acid 2.4 parts methyl methacrylate 117.6 parts “SR-1025” 13 0.5 part 0.48 parts ammonium persulfate 30 minutes after the completion of dropping, a solution prepared by dissolving 0.8 parts ammonium persulfate in 16 parts deionized water was added dropwise over 30 minutes, and maintained at 85 ° C. for 2 hours. . Thereafter, the temperature was lowered to 40 ° C. or lower, and the pH was adjusted to 7 to 8 with aqueous ammonia to obtain an acrylic copolymer emulsion (C-2) having a solid concentration of 47.6%.

<Manufacture of aluminum pigment paste composition>
Production Example 6
48.1 parts of aluminum pigment paste “WJE-7640” (made by Toyo Aluminum Co., Ltd., metal content 52%), 35 parts of ethylene glycol monobutyl ether, and 3 parts of phosphate group-containing resin solution (Note 2) are added to the container. Then, an aluminum pigment paste composition was obtained by mixing.
(Note 2) Phosphate group-containing resin solution: A reaction vessel is charged with a solvent consisting of 27.5 parts of methoxypropanol and 27.5 parts of isobutanol, heated to 110 ° C., and then 25 parts of styrene and n-butyl. 27.5 parts of methacrylate, 20 parts of “isostearyl acrylate” (trade name, manufactured by Osaka Organic Chemical Co., Ltd.), 7.5 parts of hydroxybutyl acrylate, 15 parts of phosphoric acid group-containing polymerizable monomer (Note 3), 2-methacryloyloxy 121.5 parts of a mixture consisting of 12.5 parts of ethyl acid phosphate, 10 parts of isobutanol and 4 parts of t-butyl peroxyoctanoate are added to the solvent over 4 hours and then t-butyl peroxyocta A mixture of 0.5 parts noate and 20 parts isopropanol is added dropwise over 1 hour and then stirred with 1 By ripening while to obtain a solid concentration of 50% phosphoric acid group-containing resin solution.
(Note 3) Phosphoric acid group-containing polymerizable monomer: Into a reaction vessel, 57.5 parts of monobutyl phosphoric acid and 41.1 parts of isobutanol were added, and 42.5 parts of glycidyl methacrylate was added dropwise over 2 hours under aeration. Next, the mixture was aged for 1 hour with stirring. Next, 5.9 parts of isopropanol was added to obtain a phosphate group-containing polymerizable monomer solution having a solid content concentration of 50%.

≪Manufacture of main ingredient ingredients≫
Production Example 7
After adding 86.1 parts of the aluminum pigment paste composition obtained in Production Example 6 and 36.4 parts of the water-soluble acrylic resin solution (B-1) obtained in Production Example 2, the mixture was stirred for 1 hour. 200 parts of the polyurethane resin emulsion (A-1) obtained in Production Example 1 and 66.7 parts of the acrylic resin emulsion (C-1) obtained in Production Example 4 are mixed to effectively use “Primal ASE60” (Note 4). It added so that the quantity of a component might be 3.0 mass parts with respect to 100 mass parts of resin solid content, and also continued stirring for 1 hour. After adjusting the obtained mixture to pH 8.0 with dimethylethanolamine, deionized water was added to obtain a main agent (I-1) having a solid content concentration of 30%. The viscosity of the main agent (I-1) was 1000 mPa · sec.
(Note 4) “Primal ASE-60”: trade name, manufactured by Rohm and Haas, polyacrylic acid viscosity modifier, acid value 270 mg KOH / g, active ingredient 28%.

Production Example 8
In the above Production Example 7, the main component (I-) having a solid content concentration of 30% was prepared in the same manner as in Production Example 7 except that the entire amount of the water-soluble acrylic resin solution (B-1) was replaced with the water-soluble acrylic resin solution (B-2). 2) was obtained. The viscosity of this main agent (I-2) was 1000 mPa · sec.

Production Example 9 (for comparative example)
In Production Example 7, the same as in Production Example 7 except that the amount of the active ingredient of “Primal ASE 60” (Note 4) is 5.5 parts by mass with respect to 100 parts by mass of the resin solid content. The main agent (I-3) was obtained. The viscosity of the main agent (I-3) was 3000 mPa · sec.

Production Example 10 (for comparative example)
After adding 86.1 parts of the aluminum pigment paste composition obtained in Production Example 6 and 63.6 parts of the water-soluble acrylic resin solution (B-1) obtained in Production Example 2, the mixture was stirred for 1 hour. 11. 100 parts of the polyurethane resin emulsion (A-1) obtained in Production Example 1 and 63.6 parts of the acrylic resin emulsion (C-1) obtained in Production Example 4 were mixed to obtain “Primal ASE 60” (Note 4). 5 parts were added and stirring was continued for an additional hour. After adjusting the obtained mixture to pH 8.0 with dimethylethanolamine, deionized water was added to obtain a main agent (I-4) having a solid content concentration of 30%. The viscosity of this main agent (I-4) was 1300 mPa · sec.

≪Manufacture of viscosity modifier component (II) ≫
Production Example 11
Add 109.1 parts of the water-soluble acrylic resin solution (B-1) obtained in Production Example 2 and 50.4 parts of the acrylic resin emulsion (C-2) obtained in Production Example 5 to the stirring and mixing vessel. After stirring for an hour, 20 parts of “UH-756VF” (Note 5) was added and stirring was continued for another hour. After adjusting the obtained mixture to pH 8.0 with dimethylethanolamine, deionized water was added to obtain a viscosity modifier component (II-1) having a solid content concentration of 10%. The viscosity of the viscosity modifier component (II-1) was 1500 mPa · sec.
(Note 5) “UH-756VF”: trade name, manufactured by ADEKA, urethane-associated viscosity modifier, active ingredient 32%.

Production Example 12
In the said manufacture example 11, solid content density | concentration is carried out similarly to the said manufacture example 11, except replacing the acrylic resin emulsion (C-2) by the water-soluble acrylic resin solution (B-1) so that solid content may become the same amount. Of 10% of viscosity modifier component (II-2) was obtained. The viscosity of the viscosity modifier component (II-2) was 1000 mPa · sec.

Production Example 13
In the said manufacture example 11, it is solid like the said manufacture example 11 except the solid content mass ratio of a water-soluble acrylic resin solution (B-1) and an acrylic resin emulsion (C-2) being 50/50. A viscosity modifier component (II-3) having a partial concentration of 10% was obtained. The viscosity of the viscosity modifier component (II-3) was 500 mPa · sec.

Production Example 14 (for comparative example)
20 parts of “UH-756VF” (Note 5) was added to 942.9 parts of deionized water and adjusted to pH 8.0 with dimethylethanolamine to obtain a viscosity modifier component (II-4). The viscosity of the viscosity modifier component (II-4) was 500 mPa · sec.

Production Example 15 (for comparative example)
In the above production example 12, the solid content concentration is the same as in production example 12 except that the water-soluble acrylic resin solution (B-1) is entirely replaced with the urethane resin emulsion (A-1) so that the solid content is the same. 10% of a viscosity modifier component (II-5) was obtained. The viscosity of the viscosity modifier component (II-5) was 5000 mPa · sec.

≪Manufacture of viscosity modifier component (III) ≫
Production Example 16
To the stirring and mixing vessel, 995 parts of deionized water and 5 parts of “Laponite RD” (Note 6) were added and stirred to obtain a viscosity modifier component (III-1). The viscosity of the viscosity modifier component (III-1) was 10 mPa · sec.
(Note 6) “Laponite RD”: trade name, Wilber Ellis Co., Ltd., synthetic layered silicate, 100% active ingredient
Production Example 17
Add 695 parts of deionized water, 300 parts of urethane resin emulsion (A-1) and 5 parts of “Laponite RD” (Note 6) to the stirring and mixing container, and stir and mix to obtain the viscosity modifier component (III-2). It was. The viscosity of the viscosity modifier component (III-2) was 300 mPa · sec.

Production Example 18
965 parts of deionized water, 30 parts of barium sulfate, and 5 parts of “Laponite RD” (Note 6) were added to the stirring and mixing vessel, and stirred and mixed to obtain a viscosity modifier component (III-3). The viscosity of the viscosity modifier component (III-3) was 30 mPa · sec.

Production Example 19
Add 665 parts of deionized water, 30 parts of barium sulfate, 300 parts of urethane resin emulsion (A-1), and 5 parts of “Laponite RD” (Note 6) to the stirring and mixing container, and stir and mix to adjust the viscosity modifier component (III -4) was obtained. The viscosity of the viscosity modifier component (III-4) was 350 mPa · sec.
Production Example 20
665 parts of deionized water, 30 parts of barium sulfate, 300 parts of urethane resin emulsion (A-1), 5 parts of “Laponite RD” (Note 6), “Uniol D-2000” (trade name, Nippon Oil & Fat Co., Ltd.) 10 parts of a company-produced polypropylene glycol having a weight average molecular weight of 2000) were added and mixed by stirring to obtain a viscosity modifier component (III-5). The viscosity of the viscosity modifier component (III-5) was 340 mPa · sec.

≪Manufacture of aqueous base coat paint composition≫
Example 1
70 parts of the main agent (I-1) obtained in the above production example and 30 parts of the viscosity modifier component (II-1) are stirred and mixed, deionized water is added, and an aqueous base coat paint having a solid content concentration of 18.5%. A composition (X-1) was obtained.

Examples 2 to 13 and Comparative Examples 1 to 7
In Example 1 above, the base and coating composition (X) having a solid content of 18.5% was prepared in the same manner as in Example 1 except that the types and proportions of the main component and viscosity modifier component were as shown in Table 1. -2) to (X-20) were obtained.

Comparative Example 8
The aqueous base coat coating composition (X-12) obtained in Example 12 above was stored at 25 ° C. for 1 week as an aqueous base coat coating composition (X-21).

≪Performance evaluation≫
Each aqueous base coat coating composition obtained in the examples and comparative examples was subjected to the following performance evaluation. The results are also shown in Table 1.

(*) Viscosity of coating composition Each aqueous base coat coating composition obtained above was adjusted to 25 ° C and measured at 60 rpm using a Brookfield viscometer. The measurement was carried out 5 minutes after the production of each aqueous base coat coating composition.
(*) Mixability Main paint (I), viscosity modifier component (II), and viscosity modifier component (III) were mixed by hand stirring for 1 minute, and the coating state was evaluated according to the following criteria.
A: Each component is uniformly mixed.
X: Each component is not uniformly mixed, and a partially nonuniform point is recognized.
(*) Sacrificial resistance: 21 punch holes with a diameter of 5 mm in a 3 cm portion from the end on the long side of the coated plate coated with a clear coating composition for an automobile body having a size of 11 × 45 cm at intervals of 2 cm. The objects provided in a row were used as the objects to be coated, and each aqueous base coat coating composition was applied with a film thickness gradient in the longitudinal direction at 25 ° C. and a relative humidity of 40%. Standing vertically, it was forcibly dried for 20 minutes so that the temperature of the coated plate was kept at 60 ° C. to obtain a test coated plate for a sagging resistance test. By examining the position where the sagging of the 2 mm coating film is observed from the lower end of the punch hole of each test coating plate obtained, and measuring the film thickness (sag limit film thickness (μm)) at this position, Evaluation was performed. The larger the sagging limit film thickness, the better the sagging resistance.
A: Sagging limit film thickness is 30 μm or more,
◯: Sagging limit film thickness is 20 μm or more and less than 30 μm,
Δ: Sagging limit film thickness is 10 μm or more and less than 20 μm,
X: Sagging limit film thickness is less than 10 μm.

(*) Finished appearance (aluminum orientation)
A coated plate coated with a clear paint for an automobile body was polished and degreased with # 800 water-resistant paper to obtain an article to be coated. Each aqueous base coat coating composition was spray-coated so as to be uniform under the conditions of 25 ° C. and 40% relative humidity. Immediately thereafter, the same aqueous base coat coating composition is applied by spray coating, and immediately thereafter, the same aqueous base coat coating composition is applied by spray coating for the third time, and immediately thereafter, the same aqueous base coat coating composition is applied. Was applied for the fourth time by spray painting. Each coating was performed under conditions of 25 ° C. and a relative humidity of 40%, and no air blowing, setting, or preheating process was provided without opening between coatings. That is, wet-on-wet continuous coating was performed. After the completion of the fourth coating, air blowing was performed at room temperature for 10 minutes using an air spray to dry the base coating film to obtain a base coating film having a dry film thickness of 15 μm. Then, as a top clear finish, 100 parts of “Letane PG Multi Clear HX (Q)” (trade name, clear paint containing hydroxyl group-containing acrylic resin, manufactured by Kansai Paint Co., Ltd.) Top clear paint, 50 parts of Kansai Paint Co., Ltd., hexamethylene diisocyanate isocyanurate-type polyisocyanate curing agent) mixed just before painting, is air-sprayed onto the base coat film to a dry film thickness of 40 μm and dried. Using a machine, the coating plate was forcibly dried for 20 minutes so that the temperature of the coated plate was kept at 60 ° C., and the obtained coating surface was visually evaluated.
A: The aluminum pigment is oriented parallel and uniformly to the coating surface, and no metallic unevenness is observed.
○: Although the aluminum pigment is oriented in parallel and uniformly to the coating surface, the occurrence of metallic unevenness is very slight.
Δ: The aluminum pigment is not parallel and uniformly oriented with respect to the coating surface, and many occurrences of metallic unevenness are observed.
X: The aluminum pigment was not parallel and uniformly oriented with respect to the coating surface, and the occurrence of metallic unevenness was observed very often.

(*) Hiding property In the above-described finished appearance evaluation test, a base coat coating film was obtained in the same manner as in the above, except that the water-borne base coat coating composition was continuously coated except that the coated object was a black and white hiding rate test paper. The hiding property was evaluated by the difficulty of distinguishing the black and white of the base of the obtained coated plate.

◎: Very good concealment,
◯: Good concealment,
Δ: Slightly poor concealment
X: Poor concealment property.
(*) Adhesion Cut each test coating plate obtained in the above finished appearance evaluation with a cutter so that it reaches the substrate, make 100 goby meshes of 1mm x 1mm size, and attach adhesive tape to the surface Then, the remaining number of Gobang eyes coatings after the tape was abruptly peeled at 20 ° C. was examined.
A: 100 remaining,
○: 99 to 90 remaining,
Δ: 89 to 41 remaining,
X: 40 or less remained.
(*) Water resistance Each test plate obtained by the above-described finished appearance evaluation was immersed in warm water at 40 ° C. for 10 days and pulled up, and then the surface of each coating film was observed.
A: Very good,
○: Good,
Δ: Slight abnormalities such as swelling and whitening are observed,
X: Remarkably abnormalities such as blistering and whitening are observed.

Claims (8)

A multi-component aqueous colored basecoat coating composition for preparing an aqueous colored basecoat coating composition by mixing two or more components before coating,
The water-dilutable resin component (A), the pigment (B), the polyacrylic acid viscosity modifier (C) having an active ingredient acid value of 80 to 280 mgKOH / g, and water, and the water-dilutable resin component (A) The water-dilutable urethane resin as a part of the component contains 40% by mass or more in the solid content of the component (A), and the amount of the active ingredient of the polyacrylic acid viscosity modifier (C) is water-dilutable. A main ingredient component (I) in the range of 0.01 to 5.0% by mass relative to the solid content of the resin component (A);
Water-dilutable resin component (D), urethane-associative viscosity modifier (E) (excluding the water-dilutable urethane resin) and water, and water-dilutable resin component (D) is diluted with water as part of the components sexual acrylic resin (d1) with a solid content viewed contains more than 50 wt% in the (the polyacrylic acid viscosity modifier (C) excluding) (D) component solids, or does not contain water-dilutable urethane resins, Viscosity modifier component (II) containing water-dilutable urethane resin in component (D) solid content of less than 40% by mass in solid content ,
A multi-component water-based base coat composition comprising a combination of The water- reducible resin component (A) in the main component (I) is a water-soluble acrylic resin having a solid content acid value of 10 to 70 mgKOH / g in addition to the water-dilutable urethane resin and an acrylic resin comprising the dispersion stabilizer as constituent components. The multi-component water-based base coat composition according to claim 1, further comprising an emulsion (excluding a water-soluble acrylic resin) . The mass ratio of the main ingredient component (I) and the viscosity modifier component (II) is in the range of 40 to 95 parts by mass of component (I) and 5 to 60 parts by mass of component (II) based on 100 parts by mass in total. The multi-component water-based base coat composition according to claim 1 or 2. A multi-component system in which the viscosity modifier component (III) is further combined with the main component (I) and the viscosity modifier component (II), and the viscosity modifier component (III) is an inorganic viscosity modifier The multi-component water-based base coat composition according to any one of claims 1 to 3, comprising (F) and water. The multicomponent water-based base coat composition according to claim 4, wherein the viscosity modifier component (III) further comprises a water-dilutable resin component (G). The water-dilutable resin component (G) in the viscosity modifier component (III) contains a water-dilutable urethane resin as a part of the component, and a multi-component aqueous colored base coat coating composition according to claim 5, The multi-component water-based base coat composition according to any one of claims 4 to 6, wherein the viscosity modifier component (III) further comprises a pigment. The mass ratio of the main component (I), the viscosity modifier component (II) and the viscosity modifier component (III) is 30 to 80 parts by mass, and the component (II) is 30 to 80 parts by mass based on the total of 100 parts by mass. The multi-component aqueous colored base coat composition according to any one of claims 4 to 7, wherein 1 to 40 parts by mass and component (III) are in the range of 0.5 to 50 parts by mass.