JP2015187246A - Aqueous coloring base coating composition and repair coating method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous coloring base coating composition which is useful for repairing coating of an automobile or the like and suitable for forming a coating film for repair having an excellent finishing property without giving a sense of incompatibility to an existing coating film, and to provide a repair coating method using the same.SOLUTION: There are provided: an aqueous coloring base coating composition which comprises a resin component (A) containing a water dispersion type acrylic resin (a1), a water dispersion type polyurethane resin (a2) and a water-soluble acrylic resin (a3), an organic solvent (B) containing a hydroxyl-containing organic solvent (b1) having a boiling point of 150°C or less and an aqueous solubility of 10 or more, a coloring pigment (C) and water, wherein the total solid content of the resin (a1) and the resin (a2) is 80 mass% or more, the ratio of the hydroxyl-containing organic solvent (b1) in the organic solvent (B) is 50 mass% or more and the aqueous coloring base coating composition contains a composition having a water contact angle at one minute after dropwise adding on a dried coating film to be formed of 40° or less as a main agent component; and a repair coating method using the aqueous coloring base coating composition.

Description

  The present invention relates to a water-based coloring base coating composition used for repair coating of an existing coating film such as an automobile body and a repair coating method using the same.

  In recent years, from the viewpoint of environmental protection, water-based paints are also required in the paint field. Compared to other organic solvents for paints, water has a unique property that it has a high boiling point for its low molecular weight and has a high surface tension and dielectric constant. These factors greatly affect the paint workability of water-based paints. Water-based paints are generally poorer in workability than organic solvent-based paints, and it is known that the resulting coatings are not likely to have high gloss. ing.

  As a measure for improving the paint workability of the aqueous paint and the finish of the formed coating film, for example, a method of improving the resin for paint used in the aqueous paint is generally performed.

  However, in the field of automotive repair coating, the coating environment such as temperature and humidity varies greatly depending on the repair coating site, and it is difficult to obtain a stable finished appearance by using a water-based paint that is greatly affected by the coating environment that fluctuates from time to time. It is said that.

  With respect to such problems, Patent Document 1 includes a water-based paint containing an organic solvent having a specific HLB value, so that the workability of painting is good and the finish of the formed coating film is not affected by the painting environment. It is described that it becomes good.

  By the way, in the top coating process in automotive repair coating, a base coating for repair with a similar color that has the same appearance as the existing coating film is applied to the ground-treated surface with a putty, primer surfacer, etc. in multiple steps. It is common to paint. And it is often performed that air blow is performed with compressed air as needed between each coating to speed the drying of each top-coated colored base coating film.

  When the water-based paint described in Patent Document 1 is used as a top coat colored base paint for repairing and one coat and one air blow are applied in stages, the familiarity of the dried paint film and the applied colored base paint is not sufficient. The coated film obtained after completion of the top coating process sometimes had skin roughness or unevenness.

  On the other hand, in Patent Documents 2 to 3, a water-based coating composition is composed of a main agent component (I), a viscosity modifier component (II) and a viscosity modifier component (III). It is described that a coating film having no defects such as can be obtained.

  According to these patent documents, a coating film having no defects is obtained even when the aqueous coating composition is continuously applied wet-on-wet, and the repair coating process can be greatly simplified. Even if a drying process is provided between the paintings, slight roughness or unevenness is observed in the formed coating film, and it cannot be said that it has reached the purpose of reproducing the color tone of the existing coating film, and is still improved. There is room for.

JP-A-2005-213274 JP 2001-316612 A International Publication WO2013 / 002121 Pamphlet

The present invention proposes a water-based coloring base coating composition suitable for forming a high-quality repair coating film that is useful for repair coating of automobiles and the like, and a repair coating method using the same. There is to do.

  As a result of intensive studies on the above-mentioned problems, the inventors of the present invention performed stepwise coating when the coating film based on the main component used in the aqueous coloring base coating composition has a specific composition and a specific range of water contact angle. As a result, the present inventors have found that the conformability of overcoating is improved.

That is, the present invention
Resin component (A) including water-dispersible acrylic resin (a1), water-dispersible polyurethane resin (a2), and water-soluble acrylic resin (a3), hydroxyl group having a boiling point of 150 ° C. or lower and a water solubility of 10 or higher An organic solvent (B) containing an organic solvent (b1), a coloring pigment (C) and water,
The total solid content of the resin (a1) and the resin (a2) based on the total solid content of the resin (a1), the resin (a2) and the resin (a3) is 80% by mass or more,
The proportion of the hydroxyl group-containing organic solvent (b1) in the organic solvent (B) is 50% by mass or more,
A water-based coloring base coating composition comprising a composition having a water contact angle of 40 ° or less at 1 minute after dripping in a formed dry coating film as a main component, and the water-based coloring base coating composition The present invention relates to a repair coating method characterized by being used.

  According to the aqueous colored base coating composition comprising the main component of the present invention as a constituent, it is excellent in coating workability, has good conformability when applied in stages, and has no skin roughness or unevenness. A colored base coating film having a high finished appearance without any discomfort with the above coating film is obtained.

  The present invention is characterized by the main component constituting the aqueous colored base coating composition. Hereinafter, each component contained in the main ingredient component will be described.

<Water-dispersed acrylic resin (a1)>
In the present invention, as the water-dispersible acrylic resin (a1), a copolymer obtained by copolymerizing (meth) acryloyl group-containing polymerizable unsaturated monomer as an essential component and other polymerizable unsaturated monomer as necessary is used in water. It is distributed.

  Specifically, the average particle diameter of the water-dispersed acrylic resin (a1) is in the range of 0.02 to 1.0 μm, preferably 0.05 to 0.3 μm.

  In the present specification, the average particle size of the water-dispersed resin is a value of a volume average particle size measured by a Coulter counter method at a measurement temperature of 20 ° C. The measurement by the Coulter counter method can be performed using, for example, “COULTER N4 type” (trade name, manufactured by Beckman Coulter, Inc.).

  As such a water-dispersed acrylic resin (a1), for example, the above-mentioned polymerizable unsaturated monomer component is emulsion-polymerized in one stage or in multiple stages in the presence of water and a dispersion stabilizer in the presence of a polymerization initiator. can get.

  In the present invention, the water-dispersible acrylic resin (a1) may be a single-layer type or a multi-layer type such as a core-shell type. However, a single-layer type is suitable from the viewpoint of coating compatibility.

  Examples of the polymerizable unsaturated monomer that can be a copolymer component of the water-dispersed acrylic resin (a1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl. Linear or branched alkyl (meth) acrylates such as (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (Meth) acrylate, cycloaliphatic alkyl (meth) acrylate such as isobornyl (meth) acrylate; Aralkyl (meth) acrylate such as benzyl (meth) acrylate; 2-methoxyethyl (meth) acrylate, 2-ethoxy Alkoxyalkyl (meth) acrylates such as ethyl (meth) acrylate; perfluoroalkyl (meth) acrylates; N, N-dialkylaminoalkyl (meth) acrylates such as N, N-diethylaminoethyl (meth) acrylate; (meth) Acrylamide; (meth) acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl aromatic compounds such as styrene and α-methylstyrene; 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-Trishydroxymethylethane di (meth) acrylate, 1,1,1-trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyan Polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule, such as nurate, diallyl terephthalate, divinylbenzene; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3 Hydroxypropyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as hydroxybutyl (meth) acrylate, allyl alcohol, ε-caprolactone modified form of the above hydroxyalkyl (meth) acrylate, containing polyoxyethylene chain whose molecular terminal is a hydroxyl group Hydroxyl group-containing polymerizable unsaturated monomers such as (meth) acrylate; carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate; (meth) acrolein, formylstyrol, C4-C7 vinyl alkyl ketone (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), acetoacetoxyethyl (meth) acrylate, acetoacetoxyallyl ester, diace Carbonyl group-containing polymerizable unsaturated monomers such as glycine (meth) acrylamide; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl Epoxy group-containing polymerizable unsaturated monomers such as (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether; isocyanatoethyl (meth) acrylate, m-isopropenyl-α, α-dimethylbenzyl Isocyanato group-containing polymerizable unsaturated monomers such as isocyanate; vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxy Alkoxysilyl group-containing polymerizable unsaturated monomers such as silane; reaction products of epoxy group-containing polymerizable unsaturated monomers or hydroxyl group-containing polymerizable unsaturated monomers with unsaturated fatty acids, dicyclopentenyloxyethyl (meth) acrylate, di Examples thereof include oxidatively curable group-containing polymerizable unsaturated monomers such as cyclopentenyloxypropyl (meth) acrylate and dicyclopentenyl (meth) acrylate, and these can be used alone or in combination of two or more.

  Further, the dispersion stabilizer used when the water-dispersed acrylic resin (a1) is emulsion-polymerized is not particularly limited. For example, sodium dialkylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, poly Anionic emulsifiers such as sodium oxyethylene alkylphenyl ether sulfate and sodium alkyldiphenyl ether disulfonate, nonionic emulsifiers such as polyoxyethylene higher alcohol ether and polyoxyethylene alkylphenyl ether, and anionic or cationic having a radical polymerizable double bond Reactive reactive emulsifiers.

  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.

  As the polymerization initiator, conventionally known polymerization initiators can be used without limitation. For example, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (tert-butyl Peroxy) -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-butylperoxide) Oxy) hexane, diisopropylbenzene peroxide, tert-butylcumylperoxy Id, 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 ), 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 ), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], dimethyl-2,2′-azobisisobutyrate, and the like.

  In the present invention, the water-dispersed acrylic resin (a1) contains a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule as a copolymerization component, and the water resistance and mediumness of the colored base coating film are as follows. Suitable from the viewpoint of sharpness and coating film hardness.

  Examples of the polyvinyl compound having at least two polymerizable unsaturated groups in one molecule include the compounds exemplified above, and they can be used alone or in combination of two or more thereof. And 0.1 to 10% by mass, preferably 0.5 to 5% by mass, based on the mass of the total polymerizable unsaturated monomer used in the production of the water-dispersible acrylic resin (a1). it can.

  The water-dispersed acrylic resin (a1) has a solid content acid value of 5 mgKOH / g or less, preferably in the range of 4 mgKOH / g, from the viewpoint of the water resistance of the colored base coating film and the coating compatibility. It is desirable.

  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.

<Water-dispersed polyurethane resin (a2)>
In the present invention, as the water-dispersible polyurethane resin (a2), those known in the art can be used without limitation. For example, a urethane prepolymer obtained by reacting a polyisocyanate, a polyol and a carboxyl group-containing diol is submerged in water. The resin emulsion obtained by dispersing can be mentioned.

  Specifically, the average particle diameter of the water-dispersible polyurethane resin (a2) can be in the range of 0.01 to 1.0 μm, particularly 0.1 to 0.5 μm.

  The polyisocyanate constituting the component includes aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, lysine diisocyanate; burette type adducts, isocyanurate cycloadducts 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, Alicyclic diisocyanate compounds such as 4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexane diisocyanate; Cyanate burette type adduct, isocyanurate cycloadduct; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1, 4-naphthalene diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, (m- or p-) phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethyl-4,4 ' -Aromatic diisocyanate compounds such as biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenylisocyanate); Of the diisocyanate compound, an isocyanurate cycloadduct; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6 -Polyisocyanate compounds having three or more isocyanate groups in one molecule such as triisocyanatotoluene, 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; Burette type adducts, isocyanurate ring adducts; excess isocyanate groups in hydroxyl groups of polyols such as ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexanetriol Amount Urethane adduct obtained by reacting a polyisocyanate compound at a rate; these urethane adduct views - let type adducts can include an isocyanurate ring adducts.

  Examples of the polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, polyoctamethylene ether glycol; dicarboxylic acid (adipic acid Succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycol (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5) -Polycondensation polyols with pentanediol, neopentyl glycol, bishydroxymethylcyclohexane, etc., such as polyethylene adipate, polybutylene adipate, poly Polyester polyols such as xamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, polyneopentyl / hexyl adipate; polycaprolactone polyol, poly-3-methylvalerolactone polyol; polycarbonate polyol; ethylene Glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, tricyclodecane dimethylol, hydrogenated bisphenol A, cyclohexane di Low molecular weight glycols such as methanol and 1,6 hexanediol; and the like. It is possible to use Te.

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

  The urethane prepolymer can be produced based on a conventionally known method.

  The water-dispersed polyurethane resin (a2) may 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-dispersible polyurethane resin (a2) preferably has a cyclic structure in the molecule because it has good middle sharpening properties for the colored base coating film.

  More preferably, it is suitable that the polyisocyanate constituting the water-dispersible polyurethane resin (a2) contains a compound derived from an alicyclic diisocyanate compound as a part of its components.

  The water-dispersed polyurethane resin (a2) has a solid content acid value of 20 mgKOH / g or less, preferably in the range of 5 to 18 mgKOH / g, from the viewpoint of the water resistance of the colored base coating film and the coating compatibility. It is desirable that

<Water-soluble acrylic resin (a3)>
In the present specification, the water-soluble acrylic resin (a3) includes, for example, a polymerizable unsaturated monomer component including an acid group-containing polymerizable unsaturated monomer, a hydroxyl group-containing polymerizable unsaturated monomer, and other polymerizable unsaturated monomers. And a resin obtained by polymerizing with a polymerization initiator in the presence of a hydrophilic organic solvent.

  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.

  In particular, by combining the carboxyl group-containing polymerizable unsaturated monomer and the phosphate group-containing polymerizable unsaturated monomer as the acid group-containing polymerizable unsaturated monomer, the coating compatibility when the composition of the present invention is applied is improved. There is an effect to.

  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.

  Moreover, as for the said water-soluble acrylic resin (a3), it is desirable to neutralize an acid group with a neutralizing agent. Examples of the neutralizing agent include the compounds exemplified above.

  The water-soluble acrylic resin (a3) generally has a solid content acid value of 5 to 150 mgKOH / g, preferably 10 to 100 mgKOH / g, a solid content hydroxyl value of 5 to 100 mgKOH / g, preferably 20 to 100 mgKOH / g, It is desirable that the 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 name) These were carried out under the conditions of 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.

<Resin component (A)>
The main component used in the present invention contains water-dispersed acrylic resin (a1), water-dispersed polyurethane resin (a2) and water-soluble acrylic resin (a3) as essential components as resin component (A). a1), the total solid content of the resin (a1) and the resin (a2) based on the total solid content of the resin (a2) and the resin (a3) is 80% by mass or more, preferably Is suitably 90% by mass or more.

  This is because the higher the proportion of the water-dispersed resin is in the above range, the better the coating compatibility when the aqueous colored base coating composition is applied repeatedly, and a coating film with a high finished appearance can be obtained. .

  Moreover, as a use ratio of the water-dispersible acrylic resin (a1) and the water-dispersible polyurethane resin (a2), the water-dispersible acrylic resin (a1) / water-dispersible polyurethane resin (a2) is a solid content mass ratio of 99/1. It is suitable from the viewpoint of the substrate adhesion and water resistance of the colored base coating film to be in the range of ˜1 / 99, preferably 80/20 to 20/80.

<Organic solvent (B)>
The main component used in the present invention is an aqueous composition, but contains an organic solvent (B).

  A conventionally known organic solvent can be used as the organic solvent (B). In particular, in the present invention, a hydroxyl group-containing organic solvent having a boiling point of 150 ° C. or lower and a water solubility of 10 or higher in the organic solvent (B) ( The ratio of b1) is 50% by mass or more, and more preferably 60% by mass or more.

  When the solvent composition of the organic solvent (B) is as described above, the coating compatibility when the aqueous colored base coating composition is applied is improved, and a colored base coating film having an excellent finished appearance is obtained. is there.

  Examples of the solvent (b1) include alcohol-based organic solvents such as methanol, ethanol, isopropanol, n-butanol, isobutanol, methoxypropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether. Ethylene glycol ether organic solvents such as ethylene glycol monoisopropyl ether; propylene glycol ether organic solvents such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether; These may be used alone or in combination of two or more.

  The content of the organic solvent (B) contained in the main component is 1 to 30% by mass, preferably 3 to 20% by mass, based on the solid content of the resin component (A) contained in the main component. Can do.

<Coloring pigment (C)>
In the present invention, conventionally known pigments (C) 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.

  Further, as the glitter pigment, it is desirable to use aluminum flakes coated with silica. This is because a coating film having a stable metallic appearance can be obtained.

  As the silica-coated aluminum pigment, commercially available products such as “Hydrolan series” (trade name, manufactured by Ecart Co.) and “Alpaste EMR series” (trade name, manufactured by Toyo Aluminum Co., Ltd.) can be used.

  The blending amount of the color pigment (C) varies depending on the pigment used depending on the intended coating color, but is generally 0.1 to 300 parts by mass with respect to 100 parts by mass of the total solid content of the resin contained in the main component. It is preferably within the range, and more preferably within the range of 0.5 to 200 parts by mass from the viewpoint of coating stability.

  The main ingredient component preferably further contains a polyether-modified silicone compound. This is because there is an effect on the wettability of the aqueous colored base coating composition and the coating familiarity with respect to the surface to be coated such as the ground surface. Examples of such polyether-modified silicone compounds include compounds in which a polyether chain is introduced at the terminal and / or side chain of polysiloxane, and the epoxy group other than the polyether chain, amino group, (meth) It may be a co-modified silicone compound in which introduction of an organic group such as an acryloyl group is used in combination.

  Examples of the polyether-modified silicone compound include KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-618, KF-6011, KF-6015. , KF-6004, X-22-4272, X-22-4952, X-22-6266, X-22-3667, X-22-4741, X-22-3939A, X-22-3908A [more; Shin-Etsu Manufactured by Chemical Industry Co., Ltd.], BYK-018, BYK-019, BYK-021, BYK-022, BYK-023, BYK-024, BYK-025, BYK-028, BYK-300, BYK-302, BYK- 306, BYK-320, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, B K-375, BYK-377, BYK-UV3510, BYK-307, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-3455, BYK-UV3500, BYKUV3530 ( Above; manufactured by Big Chemie), SILWET L-77, SILWET L-720, SILWET L-7001, SILWET L-7002, SILWET L-7604, SILWET Y-7006, SILWET FZ-2101, SILWETFZ-2104, FZ-2105, SILWET FZ-2110, SILWET FZ-2118, SILWET FZ-2120, SILWET FZ-2122, SILWETFF-2123, SILWET FZ-2130, SILWET FZ- 154, SILWET FZ-2161, SILWET FZ-2162, SILWET FZ-2163, SILWET FZ-2164, SILWET FZ-2166, SILWET FZ-2191, SILWET FZ-2203, SILWET FZ-2207, SILWET 2208, SILWET 2208Z SILWET Y-7499, SILWET FZ-3789, SF8472, BY16-004, SF8428, SH3771, SH3746, BY16-036, SH3749, SH3748, SH8400, SF8410 (or more; Toray Dow Corning Silicone Co., Ltd.), L032 Commercially available products such as L051, L066 [above; manufactured by Asahi Kasei Wacker Silicone Co., Ltd.] can be used. It can be combined.

  The polyether-modified silicone compound (D) is used in the range of 0.1 to 15% by mass, preferably 0.2 to 8% by mass, based on the solid content of the resin component (A) contained in the main component. It is desirable.

  The main ingredients are water-based paints such as viscosity modifiers, pigment dispersants, UV absorbers, light stabilizers, polymer fine particles, dispersion aids, preservatives, silane coupling agents, antifoaming agents, curing catalysts, and neutralizing agents. Other components such as paint additives generally used in the preparation may be included.

  As the viscosity modifier, conventionally known ones can be used without limitation. Specifically, polyacrylic acid viscosity modifiers such as polyacrylic acid soda, polyacrylic acid- (meth) acrylic acid ester copolymer; Polyether-based viscosity modifiers such as pluronic polyethers, polyether dialkyl esters, polyether dialkyl ethers, polyether epoxy modified products; urethane-associated viscosity modifiers; montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, Inorganic viscosity modifiers such as mica and bentonite; Fibrin derivative viscosity modifiers such as carboxymethylcellulose, methylcellulose, and hydroxyethylcellulose; Protein viscosity modifiers such as casein, sodium caseinate, and ammonium caseinate; Alginate-based viscosity modifiers such as sodium formate; Polyvinyl-based viscosity modifiers such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl benzyl ether copolymers; Maleic anhydride copolymers such as partial esters of vinyl methyl ether-maleic anhydride copolymers Polymer system viscosity modifiers; Polyamide viscosity modifiers such as polyamide amine salts.

  Among these, a polyacrylic acid-based viscosity modifier is preferable as a viscosity modifier from the viewpoint of the finished appearance of the colored base coating film.

  The active component acid value of the polyacrylic acid viscosity modifier may be, for example, 30 to 350 mg / KOH, preferably more than 100 and 300 mg / KOH or less. 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.

  The blending amount of the polyacrylic acid viscosity modifier is 0.1 to 20% by mass, preferably about 0.5 to 10% by mass, based on the solid content of the resin component (A) contained in the main component.

  The solid content concentration of the main ingredient component is generally adjusted in the range of 10 to 50% by mass, preferably 15 to 40% by mass, from the viewpoint of coating workability, concealment, and finished appearance.

  Further, the viscosity of the main component is not particularly limited, but is 100 to 3000 mPa · sec, preferably 600 to 3,000 from the viewpoint of storage stability and miscibility with the diluent component (II) described later. It can be in the range of 2000 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.

<Diluent component>
The aqueous colored base coating composition of the present invention can be a multi-component composition obtained by combining a diluent component with a main component obtained as described above.

  Examples of the diluent component include a composition containing a viscosity modifier and water.

  As the viscosity adjusting agent that can be contained in the diluent component, it can be appropriately selected from those exemplified in the description of the viscosity adjusting agent contained in the main agent component.

  In the present invention, an inorganic viscosity modifier is suitable for the viscosity modifier contained in the diluent component.

  As such inorganic viscosity modifiers, those known in the art can be used without limitation, and examples thereof include layered silicate minerals and silica particles, which are natural, synthetic, or processed products. It may be. 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) lay Products, trade name), “Aerosil RX200”, “Aerosil R812”, “AerosilR805”, “AerosilRY200”, “AerosilR202” (all are trade names made by Nippon Aerosil Co., Ltd.), “Laponite RD”, “LaponiteRDS”, “Laponite HW”, “Laponite EP”, “Laponite S482”, “Laponite OG”, “Laponite LV” (all of which can be manufactured and trade names such as Rochewood Additives Limited).

  The content of the active ingredient of the inorganic viscosity modifier in the diluent component is 0.1 to 3.0% by mass, preferably 0.3 to 2.0% by mass, based on the mass of the diluent component. Is appropriate.

  The diluent components are aqueous resins, pigments, pigment dispersants, UV absorbers, light stabilizers, polymer fine particles, dispersion aids, preservatives, silane coupling agents, antifoaming agents, surface conditioning agents, curing catalysts, organic It may contain other components such as a solvent, a neutralizing agent, and other paint additives that are usually used in the preparation of water-based paints.

  The viscosity of the diluent component is not particularly limited, but is 10 to 300 mPa · sec, preferably 10 to 10 m from the viewpoint of storage stability and miscibility with the main component (II). It can be in the range of 200 mPa · sec.

<Water-based coloring base coating composition>
In the present invention, the main ingredient component and the diluent component are each stored separately, and the painter stirs and mixes each component immediately before painting, and adjusts the viscosity with water or the like as needed, thereby providing the aqueous coloring of the present invention. A base coating composition can be prepared. 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 ingredient component and the diluent component in the aqueous colored base coating composition can be appropriately adjusted depending on the coating environment, etc., but generally the diluent component is 30 to 300 parts by mass, preferably 100 parts by mass of these main ingredient components, preferably Is in the range of 40 to 250 parts by mass, from the viewpoint of the appearance and physical properties of the colored base coating film.

  Further, in the present invention, a polyisocyanate curing agent, a blocked isocyanate curing agent, a melamine curing agent, an oxazoline curing agent, a carbodiimide curing agent, or the like, as necessary, may be included in any of the above main component and diluent component. Alternatively, it can be used as a separate component.

  The solid content concentration of the aqueous colored base coating composition of the present invention obtained as described above is generally within the range of 5 to 50% by mass, preferably 10 to 40% by mass, and the coating workability and the concealing property and the finish. Suitable from the viewpoint of appearance.

<Paint>
The aqueous coloring base 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 case of overcoating, steps such as flash-off between coatings (after coating is allowed to stand at room temperature), air blow at room temperature, and preheating at 60 ° C or less and 10 minutes or less are provided as necessary. May be.

  Drying after the application of the aqueous colored base coating composition is not particularly limited, and may be in an undried state when the top clear described below is applied repeatedly, for example, 20 to 100 ° C., It is preferable to dry at a temperature of 40 to 80 ° 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 7 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 base coating 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. Further, after the aqueous colored base coating composition is applied, a top clear coating composition may be applied on the colored base coating film.

  As such a top clear coating composition, conventionally known ones can be used without particular limitation. For example, an acrylic resin or a fluororesin containing a crosslinkable functional group such as a hydroxyl group as a main component, and a block polyisocyanate, polyisocyanate or melamine resin. A curable paint containing, for example, a curing agent, or a lacquer paint mainly composed of an acrylic resin modified with cellulose acetate butyrate can be suitably used.

  Among these, it is possible to use a two-component coating material in which a component containing a hydroxyl group-containing resin is a main component and a component containing a polyisocyanate compound is a curing agent component, so that a desired coating appearance can be obtained and forced drying conditions can be used. It is preferable because a coating film having excellent physical properties such as water resistance can be obtained.

  The top clear coating composition may further contain coating additives such as pigments, fiber derivatives, additive resins, ultraviolet absorbers, light stabilizers, surface conditioners, and curing catalysts, if necessary. .

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but 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 urethane resin emulsion:>
Production Example 1
In a reaction vessel, 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, 15.2 parts of dimethylolpropionic acid, 14.5 parts of 1,4-butanediol and 120.1 parts of isophorone diisocyanate was 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 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 17 mg KOH / g, a solid content of 30%, and an average particle size of 0.15 μm was obtained.

Production Example 2
In a reaction vessel, 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 parts of 1,4-butanediol and 120.1 parts of isophorone diisocyanate was 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 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-2) having a value of 26 mg KOH / g, a solid content of 30%, and an average particle size of 0.15 μm was obtained.

<Manufacture of acrylic resin emulsion:>
Production Example 3
In a reaction vessel, 100 parts of deionized water, “Newcol 707SF” (manufactured by Nippon Emulsifier Co., Ltd., 2.5 parts of an anionic emulsifier having a polyoxyethylene chain, solid content 30%) and a monomer mixture (styrene 9 parts, n-butyl acrylate 40 Part, 2-ethylhexyl acrylate 40 parts, 2-hydroxyethyl acrylate 10 parts, allyl methacrylate 1 part), and stirred and mixed in a nitrogen stream, and 3 parts of 3% aqueous ammonium persulfate solution was added at 60 ° C. . Then, the temperature was raised to 80 ° C., and a pre-emulsion consisting of the remaining 99 parts of the monomer mixture, 2.5 parts of “Newcol 707SF”, 4 parts of 3% ammonium persulfate and 100 parts of deionized water was added to the metering pump over 4 hours. In addition to the reaction vessel, aging was performed for 1 hour after the end of the addition. Thereafter, 33 parts of deionized water was added, the pH was adjusted to 7.5 with dimethylethanolamine, an acrylic resin emulsion (B-1) having a glass transition temperature of −44 ° C., an average particle size of 0.1 μm, and a solid content of 30%. Got.

Production Example 4
In a reaction vessel, 100 parts of deionized water, “Newcol 707SF” (manufactured by Nippon Emulsifier Co., Ltd., 2.5 parts of an anionic emulsifier having a polyoxyethylene chain, solid content 30%) and a monomer mixture (styrene 9 parts, n-butyl acrylate 39) 5 parts, 40 parts of 2-ethylhexyl acrylate, 10 parts of 2-hydroxyethyl acrylate, 0.5 part of methacrylic acid, 1 part of allyl methacrylate), and stirred and mixed in a nitrogen stream at 3 ° C. 3 parts of an aqueous ammonium persulfate solution were added. Then, the temperature was raised to 80 ° C., and a pre-emulsion consisting of the remaining 99 parts of the monomer mixture, 2.5 parts of “Newcol 707SF”, 4 parts of 3% ammonium persulfate and 100 parts of deionized water was added to the metering pump over 4 hours. In addition to the reaction vessel, aging was performed for 1 hour after the end 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 3 mg KOH / g, the glass transition temperature was −44 ° C., the average particle size was 0.1 μm, and the solid content was 30%. An acrylic resin emulsion (B-2) was obtained.

Production Example 5
In a reaction vessel, 100 parts of deionized water, “Newcol 707SF” (manufactured by Nippon Emulsifier Co., Ltd., 2.5 parts of an anionic emulsifier having a polyoxyethylene chain, solid content 30%) and a monomer mixture (styrene 9 parts, n-butyl acrylate 39) Part, 2-ethylhexyl acrylate 40 parts, 2-hydroxyethyl acrylate 10 parts, methacrylic acid 1 part, allyl methacrylate 1 part) and stirring and mixing in a nitrogen stream, 3% ammonium persulfate aqueous solution at 60 ° C Three parts were added. Then, the temperature was raised to 80 ° C., and a pre-emulsion consisting of the remaining 99 parts of the monomer mixture, 2.5 parts of “Newcol 707SF”, 4 parts of 3% ammonium persulfate and 100 parts of deionized water was added to the metering pump over 4 hours. In addition to the reaction vessel, aging was performed for 1 hour after the end 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 7 mg KOH / g, the glass transition temperature was −44 ° C., the average particle size was 0.1 μm, and the solid content was 30%. An acrylic resin emulsion (B-3) was obtained.

<Production of water-soluble acrylic resin>
Production Example 6
A mixed solvent of 27.5 parts of methoxypropanol and 27.5 parts of isobutanol is placed in a reaction vessel, heated to 110 ° C., 25 parts of styrene, 27.5 parts of n-butyl methacrylate, “Isostearyl acrylate” (Osaka Organic Chemical) 20 parts), hydroxybutyl acrylate 7.5 parts, phosphoric acid group-containing polymerizable monomer (Note 1) 15 parts, 2-methacryloyloxyethyl acid phosphate 12.5 parts, isobutanol 10 parts, t-butylperoxy 121.5 parts of a mixture consisting of 4 parts of octanoate was added to the above mixed solvent over 4 hours, and a mixture of 0.5 parts of t-butylperoxyoctanoate and 20 parts of isopropanol was added dropwise over 1 hour. Thereafter, the mixture was stirred and aged for 1 hour to obtain a water-soluble acrylic resin solution (C-1) having a solid content of 50%. The solid content hydroxyl value was 31 mgKOH / g, the solid content acid value was 80 mgKOH / g, and the weight average molecular weight was 19000.
(Note 1) 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. The mixture was further agitated and aged for 1 hour. Thereafter, 5.9 parts of isopropanol was added to obtain a phosphate group-containing polymerizable monomer solution having a solid content of 50%.

<Manufacture of aluminum pigment paste:>
Production Example 7
In a stirring and mixing container, 45.5 parts of aluminum pigment paste “Hydrolan 2156” (manufactured by Ecart Co., silica-coated aluminum flakes, pigment content 60%), 35 parts of methoxypropanol, the water-soluble acrylic resin solution obtained in Production Example 6 above ( C-1) 17.5 parts were added and stirred and mixed to obtain an aluminum pigment paste (D-1).

Production Example 8
In a stirring and mixing container, 45.5 parts of aluminum pigment paste “Hydrolan 2156” (manufactured by Ecart Co., silica-coated aluminum flake, pigment content 60%), 35 parts of ethylene glycol monobutyl ether, water-soluble acrylic resin solution (C-1) 17. 5 parts was added and stirred and mixed to obtain an aluminum pigment paste (D-2).

<Manufacture of main component:>
Example 1
After adding 93 parts of the aluminum pigment paste (D-1) obtained in Production Example 7 to the stirring and mixing vessel and stirring for 1 hour, 167 parts of the urethane resin emulsion (A-1) obtained in Production Example 1 and further Production Example After mixing 167 parts of the acrylic resin emulsion (B-1) obtained in Step 2, 17.8 parts of “Primal ASE60” (Note 2) and 1 part of the silicone compound (E-1) (Note 3) were added, Stirring was continued for 1 hour, pH was adjusted with dimethylethanolamine, and deionized water was added to obtain a main component (I-1) having a solid content of 20%. When the viscosity and pH of the main component (I-1) were measured according to the methods described in the specification, they were 1000 mPa · sec and 8.0, respectively.
(Note 2) “Primal ASE 60”: trade name, manufactured by Rohm and Haas, polyacrylic acid thickener, acid value 270 mg KOH / g, active ingredient 28%.
(Note 3) Silicone compound (E-1) “BYK-024”: trade name, manufactured by BYK-CHEMIE, polyether-modified silicone compound, active ingredient 100%.

Examples 2-6 and Comparative Examples 1-5
Main ingredient components (I-2) to (I-11) were obtained in the same manner as in Example 1 except that the combinations and blendings of the components were as shown in the following table.

(Note 4) Silicone compound (E-2): “BYK-348”, trade name, manufactured by BYK-CHEMIE, polyether-modified silicone compound, active ingredient 100%.
(Note 5) Silicone compound (E-3) “BYK-313”: trade name, manufactured by BYK-CHEMIE, polyester-modified silicone compound, active ingredient 15%.
(Note 6) Water-soluble acrylic resin solution (C-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 2-methacryloyloxy A monomer mixture prepared by dissolving 10 parts of azobisisobutyronitrile in 10 parts of ethyl) acid phosphate 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 (C-2) (solid content 55%) was obtained. The water-soluble acrylic resin (C-2) 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.

<Manufacture of diluent components>
Production Example 9
To the stirring and mixing vessel, 995 parts of water and 5 parts of “Laponite RD” (Note 7) were added and mixed by stirring to obtain diluent component (II). The viscosity was 15 mPa · sec.

  (Note 7) “Laponite RD”: trade name, manufactured by Rochwood Additives Limited, inorganic thickener, synthetic hectorite.

<Production of water-based coloring base coating composition>
Examples 7-18 and Comparative Examples 6-10
Main ingredient components (I-1) to (I-11) and diluent component (II) are sufficiently mixed by hand stirring in the blending composition shown in the following table, and water-based base coating compositions (D-1) to (D) are mixed. -17) was obtained.

<Creation of a dry coated plate containing only the main component for water contact angle evaluation>
Each main ingredient component (I-1) to (I-11) was applied on a 0.3 mm thick tin plate polished and degreased with # 800 water-resistant paper using a 200 μm applicator, and a measurement angle of 60 ° by air blowing. Was dried until the glossiness was 25, and a dry coating film of the main component alone was prepared. The glossiness was measured using a gloss meter “micro-TRI-gloss” manufactured by BYK.

<Making of evaluation coated plate for evaluation of unevenness and coating film appearance>
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. This coating object was placed horizontally and spray-coated once so that each of the water-based colored base coating compositions (D-1) to (D-17) was uniform under the conditions of 25 ° C. and relative humidity of 40%. Then, air blow was performed until the glossiness of the base coating film became 25 or less, and the dry coating film was created. Further, the same aqueous colored base coating composition was applied over the dried coating film by spray coating, and air blown until the gloss became 25 or less (second coating). Further, the same aqueous colored base coating composition was applied over the dried coating film by spray coating, and air blown until the glossiness was 25 or less (third coating). After coating, a base coat film having a dry film thickness of 15 μm was obtained. 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 immediately 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.

<Evaluation test:>
With respect to each of the above test coated plates, an evaluation test was performed for each of the following items. The results are also shown in Table 2.
(1) Water contact angle: 10 μl of water was dropped on the coating plate for water contact angle evaluation, and the contact angle for 1 minute after dropping at a measurement temperature of 20 ° C. was monitored on the model CA-X (Kyowa Interface Science Co., Ltd.) monitor. Measured. The values in the table are average values when measured three times.
(2) Repeatability of coating: In the evaluation coating plate for evaluating the appearance of the coating film, the compatibility of the paint at the stage where the colored base coating composition was applied repeatedly on the dried coating film by the colored base coating composition was visually evaluated.
A: Glossy and wet coated surface is smooth.
○: Glossy but slightly uneven on wet surface.
Δ: Slightly glossy, but wet coating surface has irregularities.
X: There is no luster and there is a large unevenness on the wet coated surface.
(3) Unevenness: Visual evaluation of metallic unevenness of each evaluation coated plate was performed.
A: No occurrence of metallic unevenness is observed.
○: Some metallic unevenness was observed, but it was within the allowable range.
Δ: Metallic unevenness was observed.
X: Many occurrences of metallic unevenness were observed.
(4) Coating film appearance: The coating film surface of each evaluation coated plate for coating film appearance evaluation was visually evaluated.
A: The coating surface is smooth.
○: The coating surface is slightly uneven.
Δ: There are irregularities on the coated surface.
X: The coating surface has large unevenness.
(5) Concealing property: The black and white concealing property at the stage where each diluted paint was spray-coated on the black and white concealing paper affixed to the coating plate was visually evaluated.
A: The base is completely hidden by spray coating twice.
○: The base is completely hidden by spraying three times.
Δ: The base is slightly seen through by spraying three times.
X: The base is seen through by spray painting three times.
(6) Middle sharpness test Evaluation plate for evaluation of coating film appearance Evaluation: When the base coat film having a dry film thickness of 15 μm was obtained, the coated plate was left at 20 ° C. for 2 hours, and the surface of the base coat film was changed to P800. Using abrasive paper, it was subjected to 5 reciprocations with a load of 50 g / cm @ 2. Thereafter, the condition of scratches on the surface of the coating film and the state of adhesion of the coating film to the abrasive paper were evaluated according to the following criteria. The results are shown in Table 3.
A: No deep scratches are observed, and no coating film adheres.
◯: Deep scratches are slightly observed, and the coating film is often attached to the abrasive paper.
Δ: Deep scratches are observed, and the coating film is often attached to the abrasive paper.
×: Many deep scratches are observed, and the adhesion of the coating film to the abrasive paper is large.

Claims (10)

Resin component (A) including water-dispersible acrylic resin (a1), water-dispersible polyurethane resin (a2), and water-soluble acrylic resin (a3), hydroxyl group having a boiling point of 150 ° C. or lower and a water solubility of 10 or higher An organic solvent (B) containing an organic solvent (b1), a coloring pigment (C) and water,
The total solid content of the resin (a1) and the resin (a2) based on the total solid content of the resin (a1), the resin (a2) and the resin (a3) is 80% by mass or more,
The proportion of the solvent (b1) in the organic solvent (B) is 50% by mass or more,
A water-based coloring base coating composition comprising a composition having a water contact angle of 40 ° or less at 1 minute after dropping in a dry coating film to be formed as a main ingredient component.   The water-based colored base coating composition according to claim 1, wherein the water-dispersible acrylic resin (a1) contains a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule as a copolymerization component.   The aqueous colored base coating composition according to claim 1 or 2, wherein the water-dispersed acrylic resin (a1) has a solid content acid value of 5 mgKOH / g or less.   The water-based colored base coating composition according to any one of claims 1 to 3, wherein the water-dispersible polyurethane resin (a2) has a cyclic structure in the molecule.   The aqueous colored base coating composition according to any one of claims 1 to 4, wherein the water-dispersed polyurethane resin (a2) has a solid content acid value of 20 mgKOH / g or less.   The aqueous coloring base coating composition according to any one of claims 1 to 5, wherein the coloring pigment (C) is an aluminum flake coated with silica.   The aqueous coloring base coating composition according to any one of claims 1 to 6, further comprising a polyether-modified silicone compound (D).   A multi-component aqueous colored base coating composition obtained by further combining a main ingredient component according to any one of claims 1 to 7 with a diluent component containing a viscosity modifier and water.   The multi-component water-based coloring base coating composition according to claim 8, wherein the use ratio of the main agent component and the diluent component is in the range of 30 to 300 parts by mass with respect to 100 parts by mass of the main agent component.   A repair coating method using the water-based colored base paint composition according to claim 1.