JP5979745B2 - 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 a metallic coating composition comprising an aqueous coating composition comprising a base coating composition containing a resin, a pigment, a thickener and water, and a diluent containing water and a thickener. However, it is described that the finish of the coating film to be 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 a binder-containing 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). It is described that such a composition has a high hiding power and can form a coating film having excellent adhesion, water resistance and intermediate sharpening properties.

  Patent Document 5 discloses an aqueous additive composition containing a layered silicate, a water-dilutable polyurethane resin, and an aqueous (meth) acrylic latex. According to such a composition, it is described that the storage stability of the composition itself is very good, and that the sprayability and finish are excellent when mixed with the silver metallic aqueous base coat coating composition.

  By the way, the purpose of car repair painting is to make the repair paint part the same finish as the old paint film on the car body. However, in order to apply repair paint to the finished car body, parts such as equipment inside the car body Cannot be dried at high temperatures to prevent it from being affected. Also, compared to industrial coating lines where the temperature and humidity are controlled, the paint environment varies greatly depending on the repair coating site. Therefore, an aqueous colored base coating composition that gives a satisfactory finished appearance at most repair coating sites. It is extremely difficult to design.

  Against this background, in recent years, the aqueous colored base coating composition used for painting is made low in solid content, and the coating is divided into 4-5 times, and every time one coat is applied, air blow (air spray etc. on the coating surface) In the actual situation, a colored base coating film is formed by drying the coating film by lightly spraying compressed air) and applying the same paint to the coating film repeatedly. Shortening or omission is required.

  However, when the composition as described in Patent Documents 1 to 5 is used and the air blow process is omitted and continuous coating is performed, that is, when the same paint is applied repeatedly by wet-on-wet, 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 Special table 2010-507007

  An object of the present invention is to provide a multi-component aqueous colored base coat coating composition which has a very good drying property and gives a colored base coating film having a stable finished appearance and excellent coating properties even when the coating environment is greatly changed. It is to provide.

  As a result of intensive studies on the above problems, the inventors of the present invention divided an aqueous colored base coat coating composition into a multi-component system containing a main ingredient component and a viscosity modifier component, and the viscosity modifier component was water. By including a dilutable resin component, a layered silicate and a condensed phosphate, the storage stability of each component itself is very good, and the composition obtained by mixing these before coating is a finished appearance. The present inventors have found that the coating composition is extremely excellent (for example, improvement in sagging resistance) and reached the present invention.

That is, the present invention
1.
A multi-component aqueous colored base coat coating composition for coating an aqueous colored base coat paint composition by mixing two or more components before painting,
A multi-component water-based base coat composition comprising a combination of a main component (I) and a viscosity modifier component (II),
The main component (I) contains a water-dilutable resin component (A), a pigment (B) and water,
The water-dilutable resin component containing the core-shell type acrylic resin emulsion (c1) in which the viscosity modifier component (II) has a solid content hydroxyl value of 40 mgKOH / g or less and a solid content acid value in the range of 1 to 50 mgKOH / g. (C), a multi-component water-based base coat composition comprising a layered silicate (D), a condensed phosphate (E) and water,
2.
The aqueous coloring base coat coating composition according to 1, wherein the water-dilutable resin component (A) in the main component (I) contains a water-dilutable urethane resin in a solid content of 40% by mass or more in the solid content of the component (A). ,
3.
The water- reducible resin component (A) in the main ingredient component (I) is a water- reducible urethane resin, a water-soluble acrylic resin having a solid content acid value of 5 to 100 mgKOH / g, and an acrylic resin emulsion comprising a dispersion stabilizer as constituents ( 3. A multi-component aqueous colored base coat coating composition according to item 1 or 2, comprising a water-soluble acrylic resin)
4).
The aqueous colored base coat coating composition according to any one of 1 to 3, wherein the main component (I) further comprises a polyacrylic acid viscosity modifier having an active ingredient acid value of 30 to 300 mgKOH / g ,
5.
1 item | term thru | or the mass ratio of main ingredient component (I) and viscosity modifier component (II) exists in the range of 10-100 mass parts of viscosity modifier components (II) on the basis of 100 mass parts of main ingredient component (I) 5. The multi-component aqueous colored base coat coating composition according to any one of items 4 ;
6).
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 a water-dilutable resin component The multi-component aqueous colored base coat coating composition according to any one of items 1 to 5 , which comprises (F) and a polyacrylic acid viscosity modifier (G), and water,
7).
7. The multi-component aqueous colored base coat coating composition according to 6 , wherein the water-reducible resin component (F) in the viscosity modifier component (III) includes a water-reducible acrylic resin (f1).
8).
Water-dilutable acrylic resin contained in the viscosity modifier component (III) (f1) The aqueous colored base coating composition of the multicomponent system according to item 7 comprising a water-soluble acrylic resin and acrylic resin emulsion,
9.
Viscosity modifier based on the total mass ratio of the main agent component (I), the viscosity modifier component (II) and the viscosity modifier component (III) being 100 parts by mass of the main agent component (I) and the viscosity modifier component (II). The multi-component water-based base coat composition according to any one of items 6 to 8, wherein the component (III) is in the range of 1 to 200 parts by mass,
About.

  The main component (I) and the viscosity modifier component (II) according to the present invention have good storage stability and miscibility between the components, and the aqueous colored base coat coating composition obtained by mixing these components is, A coating film with very good sagging resistance and high finish can be formed.

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

≪Main ingredient component (I) ≫
The main component (I), which is a constituent of the aqueous colored base coat coating composition of the present invention, contains a water-dilutable resin component (A), a pigment (B) and water.

<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 desirable to include.

  When the content of the water-dilutable urethane resin is within this range, the adhesion, water resistance and hiding property of the base coat film formed from the aqueous colored base coat coating composition of the present invention are improved, which is preferable.

  In this specification, solid content means non-volatile content, means a residue obtained by removing volatile components such as water and organic solvent from a sample, and the mass of the sample is multiplied by the solid content concentration. Can be calculated. The solid content concentration can be obtained 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 may be expressed as a 100 fraction.

  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 this specification, the average particle size is a value measured by diluting a sample with deionized water using a submicron particle size distribution measuring apparatus “COULTER N4 type” (manufactured by Beckman Coulter, Inc.) 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. 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 for the polymerization is a solvent having high miscibility with water, and examples thereof include an organic solvent that dissolves at least 20 g in 100 g of water at 20 ° C. Specifically, methanol, ethanol , Isopropanol, n-butanol, isobutanol and other alcohol-based organic solvents; dioxane, tetrahydrofuran and other ether-based organic solvents; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether Ethylene glycol ether organic solvents such as ethylene glycol mono n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono tert-butyl ether; 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 suitably 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.

  Further, the dispersion stabilizer used for emulsion polymerization of the acrylic resin emulsion is not particularly limited. For example, sodium dialkylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, polyoxyethylene alkylphenyl ether sulfate Anionic emulsifiers such as sodium 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 main component (I) may be prepared by mixing the pigment dispersion with other components.

  The main component (I) includes a viscosity modifier, 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, an organic solvent, It may contain other components such as paint additives that are usually used in the preparation of water-based paints such as a compatibilizer.

  Of these, conventionally known viscosity modifiers can be used without limitation, but it is desirable to use polyacrylic acid viscosity modifiers.

  The reason is that the main ingredient component (I) contains a polyacrylic acid-based viscosity modifier, so that the main ingredient component (I) can be stably stored, and is further obtained by mixing with the viscosity modifier component (II) described later. This is because the base coat coating composition can form a coating film having a good finished appearance without occurrence of unevenness and sagging.

  Examples of the polyacrylic acid viscosity modifier (C) include polyacrylic acid soda, polyacrylic acid- (meth) acrylic acid ester copolymer, and the like.

  As an active ingredient acid value of this polyacrylic acid type viscosity regulator, it can be in the range of 30-300 mgKOH / g, Preferably it is 80-280 mgKOH / g. 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 this specification, an active ingredient means the residue remove | excluding diluents, such as water and an organic solvent, from a sample.

  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). The storage stability of the main component (I) and the water-colored base coat coating composition that is within the range of mass%, preferably 1.0 to 4.5 mass%, shorten or reduce the air blowing process between each coating. Suitable from the standpoint of sagging resistance when continuously coated, mixing of the main component (I) with the viscosity modifier component (II) or viscosity modifier component (III), and the finished appearance of the base coat film ing.

  The solid content concentration of the main component (I) obtained as described above is generally adjusted to be within a range of 15 to 50% by mass, and preferably within a range of 20 to 40% by mass. Suitable from the viewpoint of finished appearance.

  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) ≫
The viscosity modifier component (II) in the present invention is a viscosity that improves the coating workability without sagging during coating by mixing the viscosity modifier component (II) immediately before coating with the main component (I). By configuring the water-based colored base coat coating composition in this way, the storage stability of each component is maintained, and even when continuously applied, unevenness and the like are generated without sagging. A base coating film having an excellent finished appearance can be formed.

  The viscosity modifier component (II) includes a water-dilutable resin component (C), a layered silicate (D), a condensed phosphate (E), and water.

<Water-dilutable resin component (C)>
The water-dilutable resin component (C) contained in the viscosity modifier component (II) is not particularly limited and can be exemplified by the same compounds as those exemplified in the description of the water-dilutable resin component (A). . When the viscosity modifier component (II) contains the water-dilutable resin component (C), there is an effect of improving sagging resistance, particularly sagging resistance during continuous coating.

  In the present invention, the water-reducible resin component (C) in the viscosity modifier component (II) preferably contains a water-reducible acrylic resin as a part of the component.

  As the water-dilutable acrylic resin, conventionally known ones can be used without limitation, and can be appropriately selected from water-soluble acrylic resins and acrylic resin emulsions as exemplified in the description of the main component (I). The solid content hydroxyl value is 40 mg KOH / g or less, particularly 20 mg KOH / g or less, more particularly 5 mg KOH / g or less, and the solid content acid value is in the range of 1 to 50 mg KOH / g, preferably 5 to 30 mg KOH / g. The water-reducible acrylic resin (c1) inside is suitable.

  By having the solid content hydroxyl value and solid content acid value of the water-dilutable acrylic resin (c1) within the above ranges, the storage stability of the viscosity modifier component (II) is good, and this and the main component (I ) Can be improved in the sagging resistance and water resistance of the aqueous colored base coat coating composition prepared.

  Examples of the water-dilutable acrylic resin (c1) having a hydroxyl value and an acid value in the above-mentioned range are, for example, a core-shell type acrylic resin obtained by polymerizing a polymerizable unsaturated monomer in multiple stages in the presence of water and a dispersion stabilizer. It is desirable to use an emulsion.

  Examples of the polymerizable unsaturated monomer used in the production of the core-shell type 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. From the viewpoint of storage stability of the viscosity modifier component (II) and water resistance of the base coat film, a reactive emulsifier is used. It is desirable to use

  The water-dilutable acrylic resin (c1) contained in the water-dilutable resin component (C) has a solid content of 10 mass% or more, preferably 50 mass% or more in the solid content (C). It is suitable to be.

<Layered silicate (D)>
The layered silicate (D) may be any of natural, synthetic and processed products. Specific examples include montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, mica and bentonite.

  Moreover, in the case of a synthetic product, it can be produced by mixing a metal ion such as sodium, magnesium, lithium and aluminum with a silicate ion source such as sodium silicate and reacting with an autoclave.

  As the layered silicate (D), a commercially available product such as “LAPONITE” (trade name, manufactured by Williver Ellis) can also be used.

  The effective component content of the layered silicate (D) in the viscosity modifier component (II) is 1 to 100 masses based on the solid content of the water-dilutable resin component (C) in the viscosity modifier component (II). %, Preferably in the range of 5 to 50% by mass from the viewpoints of storage stability of the viscosity modifier component (II), sagging resistance during continuous coating of the aqueous colored base coat coating composition, and finished appearance. .

<Condensed phosphate (E)>
Examples of the condensed phosphate include pyrophosphates such as sodium pyrophosphate, potassium pyrophosphate, and ammonium pyrophosphate; tripolyphosphates such as sodium tripolyphosphate; and sodium metaphosphates such as sodium hexametaphosphate. Among these, it is preferable to use pyrophosphate from the viewpoint of excellent miscibility with the water-dilutable resin component (C).

  The content of the condensed phosphate (E) in the viscosity modifier component (II) is 0.1 to 15 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the layered silicate (D). It is suitable from the viewpoint of storage stability of the viscosity modifier component (II), sagging resistance during continuous coating of the aqueous colored base coat coating composition, and finished appearance.

  The viscosity modifier component (II) is a dispersion aid such as polyalkylene glycol, pigment, UV absorber, light stabilizer, polymer fine particles, preservative, silane coupling agent, antifoaming agent, curing catalyst, Other components such as paint additives that are usually used in the preparation of water-based paints such as known viscosity modifiers, organic solvents, and neutralizers other than the layered silicate (D) can be included.

  The viscosity of the viscosity modifier component (II) is generally adjusted to a solid content concentration of 1 to 30% by mass, preferably 3 to 20% by mass. It is suitable from the viewpoint of painting workability and concealment of the colored base coat coating composition, and the finished appearance.

  In addition, the viscosity of the viscosity modifier component (II) is not particularly limited, but from the viewpoint of the storage stability of the viscosity modifier component (II) and the coating workability of the aqueous colored base coat coating composition, It can be in the range of 5 to 500 mPa · sec, preferably 10 to 200 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 paint composition can be improved, and the viscosity of the aqueous colored base coat paint composition can be adjusted appropriately according to the coating environment. It can also be easier to paint.

  The viscosity modifier component (III) desirably contains a water-dilutable resin component (F), a polyacrylic acid viscosity modifier (G), and water.

<Water-dilutable resin component (F)>
The water-dilutable resin component (F) that can be contained in the viscosity modifier component (III) 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. Viscosity modifier component (III) contains water-dilutable resin component (F), so it has good mixability with main component (I) and viscosity modifier component (II), and is formed from an aqueous colored base coat coating composition. The base coat coating film can have a good finished appearance with less unevenness.

  In the present invention, the water-reducible resin component (F) contained in the viscosity modifier component (III) is a part of the component that contains the water-reducible acrylic resin (f1) as a solid component in the solid component (F). The inclusion of 50% by mass or more, particularly 60% by mass or more is suitable because it can suppress the occurrence of unevenness in the base coat film.

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

  The water-dilutable acrylic resin (f1) desirably contains a water-soluble acrylic resin as part of its components. By including the water-soluble acrylic resin, the viscosity of the viscosity modifier component (III) including the polyacrylic acid viscosity modifier is moderate without excessively increasing, and the main component (I) and the viscosity modifier component (II) The resulting aqueous colored base coat coating composition is capable of forming a base coat film having almost no appearance of 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 (III) may be the same.

  The content of the water-soluble acrylic resin contained in the water-dilutable acrylic resin (f1) is 40% by mass or more, preferably 45 to 95% by mass in the solid content of the (f1) solid content. It is desirable to be.

  The water-dilutable acrylic resin (f1) contained in the viscosity modifier component (III) 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 appropriately selected from the acrylic resin emulsions exemplified in the description of the main component (I) and the viscosity modifier component (II). It may be the same as the acrylic resin emulsion contained in the main component (I) and / or the viscosity modifier component (II).

  In the present invention, as the acrylic resin emulsion contained in the viscosity modifier component (III), the solid content hydroxyl value exemplified in the description of the water-dilutable acrylic resin (c1) contained in the viscosity modifier component (II) is A core-shell type acrylic resin emulsion having 40 mg KOH / g or less, particularly 20 mg KOH / g or less, more particularly 5 mg KOH / g or less, and a solid content acid value in the range of 1 to 50 mg KOH / g, preferably 5 to 30 mg KOH / g is suitable. is there.

  When the viscosity modifier component (III) contains the above-described core-shell type acrylic resin emulsion together with the polyacrylic acid viscosity modifier (G) described later, the mixing property with the main agent (I) and the viscosity modifier component (II) is good. In addition, the sagging resistance and finished appearance of the aqueous colored base coat coating composition during continuous coating are good, and the water resistance of the colored base coat coating film is improved.

  The content of the acrylic resin emulsion contained in the water-reducible acrylic resin (f1) is within the range of 1 to 60% by mass, preferably 5 to 55% by mass in solid content in the (f1) solid content. Is desirable.

<Polyacrylic acid viscosity modifier (G)>
In the present invention, the viscosity modifier component (III) preferably contains a polyacrylic acid viscosity modifier (G). When the viscosity modifier component (III) contains the polyacrylic acid viscosity modifier (G), there is an effect of improving the sagging resistance of the aqueous colored base coat coating composition of the present invention.

  As the polyacrylic acid viscosity modifier (G), the same ones as exemplified in the description of the polyacrylic acid viscosity modifier contained in the main component (I) can be used.

  The effective component content of the polyacrylic acid viscosity modifier (G) in the viscosity modifier component (III) is 100 parts by mass of the water-dilutable resin component (F) solid content contained in the viscosity modifier component (III). 1-50 parts by mass, preferably 5-50 parts by mass, more preferably 10-40 parts by mass from the viewpoint of sagging resistance at the time of continuous coating of the base coat film and the finished appearance Is suitable.

  The above viscosity modifier component (III) is pigment, pigment dispersant, ultraviolet absorber, light stabilizer, polymer fine particles, dispersion aid, preservative, silane coupling agent, antifoaming agent, curing catalyst, polyacrylic acid type It may contain other components such as a known viscosity adjusting agent other than the viscosity adjusting agent (G), an organic solvent, a neutralizing agent and the like, and other additives such as paint additives that are usually used in the preparation of aqueous paints.

  In addition, the solid content concentration of the viscosity modifier component (III) is generally in the range of 1 to 30% by mass, preferably 3 to 20% by mass, from the viewpoints of coating workability, concealing property, and finished appearance. ing.

  The viscosity of the viscosity modifier component (III) is not particularly limited, but the storage stability of the viscosity modifier component (III) and the miscibility with the main agent component (I) and the viscosity modifier component are not limited. From the point, it can be in the range of 100 to 2000 mPa · sec, preferably 300 to 1800 mPa · sec, more preferably 400 to 1600 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, etc., but in general, the viscosity is adjusted based on 100 parts by mass of the main component (I). 10 to 100 parts by mass, preferably 20 to 80 parts by mass of the component (II), or the mass ratio of the main component (I), the viscosity modifier component (II) and the viscosity modifier component (III) is generally It is applied that the viscosity modifier component (III) is in the range of 1 to 200 parts by weight, preferably 20 to 150 parts by weight, based on the total of 100 parts by weight of the component (I) and the viscosity modifier component (II). It is suitable from the viewpoint of film concealment, finished appearance during continuous coating, and sagging resistance.

  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.

  Further, the viscosity of the aqueous colored base coat coating composition at the time of painting is not particularly limited, but the coating workability is within the range of 100 to 1000 mPa · sec, preferably 200 to 700 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.

  Although the number of times of coating may be one, it is desirable to coat the same paint a plurality of times, for example, 2-6 times, in order to achieve both the finished appearance and the hiding property.

  In the present invention, it is possible to have a good finished appearance without sagging the coating film even if coating is carried out continuously by omitting the air blow process performed between each coating in the case of repeated coating. If necessary, a process such as flash-off (the coated film is allowed to stand at room temperature) and air blow 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, and a primer coating film, an electrodeposition coating film, an intermediate coating film, etc. under the base coating film These coatings may be provided as appropriate.

  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 4-liter flask, 115.5 parts of polybutylene adipate having a number average molecular weight of 2000, 115.5 parts of polycaprolactone diol having a number average molecular weight of 2000, 23.2 parts of dimethylolpropionic acid, 6.5 of 1,4-butanediol Part and 120.1 parts of isophorone diisocyanate were charged in a polymerization vessel 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 water elongation reaction, acetone was distilled off at 70 ° C. or less 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 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 single-layer acrylic 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, the pH was adjusted to 7.5 with dimethylethanolamine, the solid content acid value was 6.5 mgKOH / g, the solid content hydroxyl value was 48.4 mgKOH / g, and the average particle size was 0.1 μm. An acrylic resin emulsion (C-1) having a solid content of 30% was obtained.

<Manufacture of multilayer acrylic emulsion>
Production Example 5
To a 2 liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer, 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 nitrogen substitution. 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 the remaining pre-emulsion was added dropwise over 170 minutes 20 minutes after the addition.
<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 Adekaria soap SR-1025 31.4 parts Ammonium persulfate 1.12 parts after completion of dropping After aging for a period of time, a pre-emulsion formed by emulsifying the following composition (B) 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 Adecalia soap SR-1025 13.5 parts Ammonium persulfate 0.48 parts 30 minutes after the completion of dropping, a solution prepared by dissolving 0.8 parts of ammonium persulfate in 16 parts of deionized water was added dropwise over 30 minutes and maintained at 85 ° C for 2 hours. did. Thereafter, the temperature is lowered to 40 ° C. or lower, adjusted to pH 7 to 8 with ammonia water, an acrylic copolymer having a solid content hydroxyl value of 0 mg KOH / g, a solid content acid value of 6.5 mg KOH / g, and a solid content of 47.6%. An emulsion (C-2) was obtained.

Production Example 6
To a 2 liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer, 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 nitrogen substitution. 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 the above-mentioned pre-emulsion was added dropwise over 170 minutes 20 minutes after the addition.
<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 Adekaria soap SR-1025 31.4 parts Ammonium persulfate 1.12 parts after completion of dropping After aging for a period of time, a pre-emulsion formed by emulsifying the following composition (B) 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 37.6 parts hydroxyethyl acrylate 80 parts Adeka Rear soap SR-1025 13.5 parts Ammonium persulfate 0.48 parts 30 minutes after the completion of dropping, a solution of 0.8 parts of ammonium persulfate dissolved in 16 parts of deionized water was added dropwise over 30 minutes, and 2 Hold at 85 ° C. for hours. Thereafter, the temperature is lowered to 40 ° C. or lower, adjusted to pH 7-8 with aqueous ammonia, an acrylic copolymer having a solid content of 47.6%, a solid content hydroxyl value of 48 mg KOH / g, and a solid content acid value of 6.5 mg KOH / g. An emulsion (C-3) was obtained.

<Manufacture of aluminum pigment paste composition>
Production Example 7
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 2) are added, By mixing, an aluminum pigment paste composition was obtained.
(Note 2) 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 3) 121.5 parts of a mixture consisting of 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 3) 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. And then aged for 1 hour with stirring. Subsequently, 5.9 parts of isopropanol was added to obtain a phosphate group-containing polymerizable monomer solution having a solid content of 50%.

≪Manufacture of main ingredient ingredients≫
Production Example 8
After adding 86.1 parts of the aluminum pigment paste composition obtained in Production Example 7 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 of 30%. The viscosity of the main agent (I-1) was 1000 mPa · sec.

Production Example 9
In the above Production Example 8, the main agent (I-) having a solid content concentration of 30% was prepared in the same manner as in Production Example 8 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.
(Note 4) “Primal ASE-60”: trade name, manufactured by Rohm and Haas, polyacrylic acid viscosity modifier, active ingredient acid value of 270 mg KOH / g, active ingredient 28%.

≪Manufacture of viscosity modifier component (II) ≫
Production Example 10
Add 780 parts of deionized water, 210 parts of acrylic resin emulsion (C-2), and 10 parts of “Laponite RDS” (Note 5) to the stirring and mixing container, and stir and mix to obtain the viscosity modifier component (II-1). It was. The viscosity modifier component (II-1) had a solid content concentration of 11% and a viscosity of 10 mPa · sec.
(Note 5) “Laponite RDS”: trade name, manufactured by Wilber Ellis, synthetic layered sodium silicate: sodium pyrophosphate = 94: 6 (mass ratio).

Production Example 11
In the said manufacture example 10, it replaced with the acrylic resin emulsion (C-2), and obtained the viscosity modifier component (II-2) like the said manufacture example 10 except using an acrylic resin emulsion (C-3). . The viscosity modifier component (II-2) had a solid content concentration of 11% and a viscosity of 50 mPa · sec.

Production Example 12 (for comparative example)
In the above Production Example 10, a viscosity modifier component (II-3) was obtained in the same manner as in Production Example 10 except that the one excluding sodium pyrophosphate was used. The viscosity modifier component (II-3) had a solid content concentration of 11% and a viscosity of 30 mPa · sec.

Production Example 13 (for comparative example)
In the said manufacture example 10, the viscosity regulator component (II-4) was obtained like the said manufacture example 10 except using the thing except a synthetic | combination layered sodium silicate. The viscosity modifier component (II-4) had a solid content concentration of 10% and a viscosity of 10 mPa · sec.

≪Manufacture of viscosity modifier component (III) ≫
Production Example 14
109.1 parts of the water-soluble acrylic resin solution (B-1) obtained in Production Example 2 and 50.4 parts of the multilayer acrylic resin emulsion (C-2) obtained in Production Example 4 were mixed in a stirring and mixing vessel. In addition, after stirring for 1 hour, 57.1 parts of “Primal ASE60” (Note 4) 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 (III-1) having a solid content of 10%. The viscosity of the viscosity modifier component (II-1) was 1000 mPa · sec.

Production Example 15
In the production example 14, the solid content was the same as in the production example 14 except that the acrylic resin emulsion (C-2) was replaced by the water-soluble acrylic resin solution (B-1) so that the solid content was the same. 10% of a viscosity modifier component (III-2) was obtained. The viscosity of the viscosity modifier component (III-2) was 500 mPa · sec.

Production Example 16
In the said manufacture example 14, it is solid like the said manufacture example 14 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 (III-3) having a content of 10% was obtained. The viscosity of the viscosity modifier component (III-3) was 1500 mPa · sec.

≪Manufacture of aqueous base coat paint composition≫
Example 1
100 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 coating composition having a solid content of 20% ( X-1) was obtained.

Examples 2-13 and Comparative Examples 1-2
In the above Example 1, aqueous base coat coating compositions (X-2) to (X-) in the same manner as in Example 1 except that the types and proportions of the main component and viscosity modifier component are as shown in Table 1. 15) was obtained.

Comparative Example 3
An aqueous base coat coating composition (X-16) for a comparative example was prepared by diluting the main component (I-1) with deionized water to a solid content of 20%.

Comparative Example 4
The aqueous base coat paint composition (X-1) obtained in Example 1 above was stored at 25 ° C. for 1 week to obtain an aqueous base coat paint composition (X-17).

≪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 aqueous base coat paint composition Each aqueous base coat paint composition obtained above was brought to 25 ° C. and measured at 60 rpm using a Brookfield viscometer. The measurement was performed 5 minutes after the production of each aqueous base coat coating composition.
(*) Mixability Each main agent (I), viscosity modifier component (II), and viscosity modifier component (III) were evaluated by the following criteria after agitation and mixing for 1 minute by hand stirring.
○: 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)
The coated plate coated with the clear coating composition for automobile bodies was polished and degreased with # 800 water-resistant paper to obtain a coated object. 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 between coatings. After completion of the fourth coating, air blowing was performed at room temperature (25 ° C.) 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. After that, as a top clear finish, 100 parts of “Retan PG Multiclear HX (Q)” (trade name, clear paint composition containing hydroxyl group-containing acrylic resin, manufactured by Kansai Paint Co., Ltd.) “Retan PG Multiclear Standard Curing Agent” (Product) Name, Kansai Paint Co., Ltd., Hexamethylene diisocyanate isocyanurate type polyisocyanate curing agent) 50 parts of the top clear coating composition mixed just before coating, air spray so that the dry film thickness is 40 μm on the base coat film It was painted and forcibly dried for 20 minutes using a dryer 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: Many occurrences of metallic unevenness are observed,
X: Generation | occurrence | production of metallic unevenness was recognized very much.

(*) 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.
○: Good,
Δ: Slight whitening is observed,
X: Abnormalities such as swelling and whitening are observed.

Claims (9)

A multi-component aqueous colored base coat coating composition for coating an aqueous colored base coat paint composition by mixing two or more components before painting,
A multi-component water-based base coat composition comprising a combination of a main component (I) and a viscosity modifier component (II),
The main component (I) contains a water-dilutable resin component (A), a pigment (B) and water,
The water-dilutable resin component containing the core-shell type acrylic resin emulsion (c1) in which the viscosity modifier component (II) has a solid content hydroxyl value of 40 mgKOH / g or less and a solid content acid value in the range of 1 to 50 mgKOH / g. (C), layered silicate (D), condensed phosphate (E), and a multi-component water-based base coat coating composition characterized by comprising water. The water-based base coat composition according to claim 1, wherein the water-dilutable resin component (A) in the main component (I) contains a water-dilutable urethane resin in a solid content of 40% by mass or more in the solid content of the component (A). object. The water- reducible resin component (A) in the main ingredient component (I) is a water- reducible urethane resin, a water-soluble acrylic resin having a solid content acid value of 5 to 100 mgKOH / g, and an acrylic resin emulsion comprising a dispersion stabilizer as constituents ( The multi-component water-based base coat composition according to claim 1 or 2, comprising a water-soluble acrylic resin) . The water-based base coat composition according to any one of claims 1 to 3, wherein the main component (I) further comprises a polyacrylic acid viscosity modifier having an active ingredient acid value of 30 to 300 mgKOH / g . The mass ratio of the main agent component (I) and the viscosity modifier component (II) is within the range of 10 to 100 parts by mass of the viscosity modifier component (II) based on 100 parts by mass of the main agent component (I). 5. The multicomponent water-based base coat composition according to any one of items 4 to 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 a water-dilutable resin component The multi-component water-based base coat composition according to any one of claims 1 to 5 , comprising (F), a polyacrylic acid viscosity modifier (G), and water. The multi-component water-based base coat composition according to claim 6 , wherein the water-reducible resin component (F) in the viscosity modifier component (III) comprises a water-reducible acrylic resin (f1). The multi-component water-based base coat composition according to claim 7 , wherein the water-dilutable acrylic resin (f1) contained in the viscosity modifier component (III) includes a water-soluble acrylic resin and an acrylic resin emulsion. Viscosity modifier based on the total mass ratio of the main agent component (I), the viscosity modifier component (II) and the viscosity modifier component (III) being 100 parts by mass of the main agent component (I) and the viscosity modifier component (II). The multi-component water-based base coat composition according to any one of claims 6 to 8 , wherein the component (III) is in the range of 1 to 200 parts by mass.