JP2015187247A - Aqueous metallic base coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suggest an aqueous metallic base coating composition suitable for forming a coating film for repair without giving a sense of incompatibility to an old metallic coating film such as an existing metallic coating film for an automobile body or the like.SOLUTION: There are provided a multi-component aqueous metallic base coating composition which comprises a combination of a main agent component (I) and a diluent component (II), wherein the main agent component (I) comprises an urethane resin emulsion (A), an acrylic resin emulsion (B), a brilliant pigment (C) and water, the diluent component (II) comprises a viscosity modifier and water, silica particles (D) are contained in the composition and the silica particles (D) have an average particle diameter in the range of 0.1 to 25.0 μm; and a repair coating method using the composition.

Description

  The present invention relates to an aqueous metallic base coating composition used for repair coating of existing metallic coatings such as automobile bodies.

  Metallic base paint compositions containing metal pigments typified by aluminum pigments may cause metallic unevenness depending on the dispersion state of the metal pigment in the paint and the orientation state in the coating film. However, it is known that problems such as inability to obtain a metallic luster are produced, and various proposals for improvement thereof have been made.

  For example, Patent Document 1 discloses a metallic base coating composition containing a specific amount of a film-forming resin and an aluminum flake pigment having an average particle diameter and an average particle diameter thickness in a specific range.

  Patent Document 2 discloses a metallic base coating composition containing a metal pigment having a specific coupling agent adsorbed on its surface.

  Patent Document 3 describes that a metallic base coating film satisfying glitter, flip-flop properties, and concealment properties can be obtained by selectively using three different types of aluminum flake pigments.

  According to Patent Documents 1 to 3, it is possible to obtain a metallic coating film having an excellent appearance that gives high glitter and prevents metallic unevenness.

  In recent years, due to environmental considerations, water-based applications have also been required in the field of metallic base coating compositions.

  It is well known that the appearance of a coating film made of an aqueous metallic base coating composition is greatly influenced by humidity and is difficult to paint.

  By the way, when repairing an object provided with a high-quality coating film such as an automobile body, it is necessary that the repair coating film formed by the repair coating has a finished appearance equivalent to that of an existing coating film.

  In this case, since the completed automobile body is subjected to a repair coating, the repair coating film cannot be dried at a high temperature so that parts such as equipment inside the body are not affected.

  Compared to the fact that the industrial coating line is stable within the control range, the painting environment varies greatly depending on each repair painting site. Therefore, it is necessary to have a finished appearance without any sense of incongruity.

  In addition, in the case of automobile repair painting, there is a case where the paint from the repaired part to the unrepaired part is applied with a thick film to a thin film to make the color difference between the repaired part and the unrepaired part inconspicuous. .

  Therefore, when repair painting of an automobile body having a metallic color is performed with a water-based metallic base coating composition, the coating environment is not controlled, and the repair coating cannot be dried at a high temperature. Not only the color but also the metallic feeling must be reproduced with the repaired metallic coating film, and further, it is required to match the metallic feeling of the thin film portion and the thick film portion in the above-described blur coating.

  Patent Documents 1 to 3 describe that a metallic coating excellent in metallic feeling and concealment can be obtained, which is newly applied on an intermediate coating or a substrate in a controlled coating environment. The repair metallic coating is combined with the existing metallic coating not only for its color, but also for the metallic sparkle, and further, measures for obtaining a natural appearance that does not give a sense of incongruity when blurred coating is applied. Is not disclosed at all.

  On the other hand, Patent Document 4 is composed of 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, An aqueous coating composition having rheological properties with suitable sag resistance is described.

  However, although the composition described in Patent Document 4 is excellent in dripping resistance and can significantly reduce the drying time, metallic unevenness of the obtained coating film is remarkable, and in particular, it is necessary to improve the finish property of the blurred paint portion. is there.

Japanese Patent Laid-Open No. 08-170034 JP 2012-1598 A JP 2005-200519 A JP 2001-316612 A

  An object of the present invention is to propose an aqueous metallic base coating composition that is suitable for forming a repair coating film that does not feel uncomfortable with an old metallic coating film such as an existing metallic coating film for an automobile body or the like.

  As a result of intensive studies on the above-mentioned problems, the present inventors have found that a natural metallic appearance with less discomfort due to a difference in film thickness by including silica having an average particle diameter in a specific range in an aqueous metallic base coating composition having a specific composition. As a result, the present invention was reached.

That is, the present invention
A multi-component aqueous metallic base coating composition comprising a combination of a main component (I) and a diluent component (II),
The main agent component (I) contains a urethane resin emulsion (A), an acrylic resin emulsion (B), a glitter pigment (C) and water, and the diluent component (II) contains a viscosity modifier and water. And
A multi-component aqueous metallic base coating composition comprising silica particles (D) in the composition and having an average particle size of silica particles (D) in the range of 0.1 to 25.0 μm; And a repair coating method using the composition.

  According to the aqueous metallic base coating composition of the present invention, it is possible to minimize the mismatch of metallic feeling due to the difference in film thickness, and it is possible to obtain a metallic base coating film having an appearance excellent in transparency and smoothness and glitter. .

  Moreover, the storage stability of each component constituting the present coating composition and the miscibility with each other are good, and the formed coating film is excellent in physical properties such as base concealing property, water resistance and adhesion.

  The aqueous metallic base coating composition of the present invention is a multi-component composition obtained by combining the main component (I) and the diluent component (II).

  The main component (I) in the present invention contains a urethane resin emulsion (A), an acrylic resin emulsion (B), a glitter pigment (C), and water.

<Urethane resin emulsion (A)>
In the present invention, any urethane resin emulsion (A) 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 dispersed in water. The resin emulsion obtained by this can be mentioned.

  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 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 urethane resin emulsion (A) 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 urethane resin emulsion (A) preferably has a cyclic structure in the molecule because the metal base coating film has good sharpening properties.

  More preferably, it is suitable that the polyisocyanate constituting the urethane resin emulsion (A) contains a compound derived from an alicyclic diisocyanate compound as a part of the component.

  The urethane resin emulsion (A) 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 metallic 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.

  As an average particle diameter of the said urethane resin emulsion (A), it can exist in the range of 0.01-1 micrometer, especially 0.05-0.5 micrometer.

  In this specification, the average particle diameter of the urethane resin emulsion (A) and the acrylic resin emulsion (B) described later is a value of a volume average particle diameter 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.).

<Acrylic resin emulsion (B)>
In the present invention, the acrylic resin emulsion (B) has a (meth) acryloyl group-containing polymerizable unsaturated monomer as an essential component, and a copolymer obtained by copolymerizing other polymerizable unsaturated monomer as necessary is dispersed in water. It will be.

Specifically, the average particle size of the acrylic resin emulsion (B) is in the range of 0.01 to 1.0 μm, preferably 0.05 to 0.5 μm.
Such an acrylic resin emulsion (B) can be obtained, for example, by emulsion polymerization of the polymerizable unsaturated monomer component in the presence of water and a dispersion stabilizer in one step or in multiple steps using a polymerization initiator. A thing can be used conveniently.

  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 acrylic resin emulsion (B) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like linear or branched alkyl (meth) acrylate; cyclohexyl (meta ) Cycloaliphatic alkyl (meth) acrylates such as acrylate and isobornyl (meth) acrylate; Aralkyl (meth) acrylates such as benzyl (meth) acrylate; 2-methoxyethyl (meth) acrylate and 2-eth Alkoxyalkyl (meth) acrylates such as siethyl (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 Polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule such as isocyanurate, diallyl terephthalate, divinylbenzene; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, -Hydroxypropyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as hydroxybutyl (meth) acrylate, allyl alcohol, ε-caprolactone modified form of the above hydroxyalkyl (meth) acrylate, polyoxyethylene chain whose molecular terminal is a hydroxyl group Hydroxyl-containing polymerizable unsaturated monomers such as containing (meth) acrylates; Carboxy group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate; (meth) acrolein, formylstyrene , Vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), acetoacetoxyethyl (meth) acrylate, acetoacetoxyallyl ester, dia Carbonyl group-containing polymerizable unsaturated monomers such as ton (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-methacryloyloxypropyltrieth Alkoxysilyl group-containing polymerizable unsaturated monomers such as silane; epoxy group-containing polymerizable unsaturated monomers or reaction products of hydroxyl group-containing polymerizable unsaturated monomers and 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 acrylic resin emulsion (B) is emulsion polymerized is not particularly limited. For example, sodium dialkylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, polyoxyethylene Anionic emulsifiers such as sodium 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 Mention may be made of 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, it is preferable that the acrylic base emulsion (B) contained in the main component (I) contains a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule as a copolymer component. It is suitable from the viewpoint of water resistance and sharpening properties of the film.

  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. , Based on the mass of the total polymerizable unsaturated monomer used in the production of the acrylic resin emulsion (B), 0.1 to 10% by mass, preferably 0.5 to 5%.

  The acrylic resin emulsion (B) has a solid content acid value of 5 mgKOH / g or less, preferably 4 mgKOH / g or less, from the viewpoint of water resistance of the metallic base coating film and coating compatibility. Is desirable.

<Brightness pigment (C)>
In the present invention, the bright pigment (C) is not particularly limited, and a bright pigment known in the paint field can be used. Specific examples thereof include non-colored or colored metallic luster materials such as metals or alloys such as aluminum, aluminum oxide, copper, zinc, iron, nickel and tin. Further, the photochromic pigment (C) includes light-interfering pigments such as metal-deposited film flakes, mica, mica surface-coated with metal oxide, mica-like iron oxide, graphite pigment, and hologram pigment. The shape of the glitter pigment (C) is not particularly limited, and it may be further colored or treated with various surface treatment agents or dispersants. These bright pigments can be used alone or in combination of two or more.

  The glitter pigment (C) may be appropriately mixed with a dispersant and a dispersion resin, dispersed, and pasted into a paint composition.

  Particularly in the present invention, it is desirable to use a silica-coated aluminum pigment as the bright pigment (C). This is because a coating film having a stable metallic appearance is 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.

≪Main ingredient component (I) ≫
In the present invention, the main agent component (I) contains a urethane resin emulsion (A) and an acrylic resin emulsion (B) as essential components as resin components, and the total amount of both is a resin solid content contained in the main agent component (I). From the viewpoint of initial adhesion and water resistance of the metallic base coating film, it is preferably in the range of 50% by mass or more, preferably 80% by mass or more.

  Moreover, as a use ratio of a urethane resin emulsion (A) and an acrylic resin emulsion (B), it is 95 / 5-5 / 95 by the urethane resin emulsion (A) / acrylic resin emulsion (B) solid content mass ratio, Preferably it is 80. The range of / 20 to 20/80 is suitable from the viewpoint of water resistance adhesion of the metallic coating film.

  Further, the blending amount of the glitter pigment (C) is suitably in the range of 1 to 60% by mass, preferably 5 to 50% by mass, based on the resin solid content contained in the main component (I).

  The main component (I) is an aqueous resin other than (A) and (B); a pigment other than (C); a viscosity modifier, a pigment dispersant, an ultraviolet absorber, a light stabilizer, polymer fine particles, a dispersion aid, It may contain other components such as antiseptics, silane coupling agents, antifoaming agents, curing catalysts, organic solvents, neutralizing agents and the like, and other additives for paints that are usually used in preparing aqueous paints.

  Examples of the aqueous resin include water-soluble acrylic resins. In the present specification, the water-soluble acrylic resin includes, 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, a hydrophilic organic solvent. And a resin obtained by polymerizing with a polymerization initiator in the presence of.

  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, the combined use of a carboxyl group-containing polymerizable unsaturated monomer and a phosphoric acid group-containing polymerizable unsaturated monomer as an acid group-containing polymerizable unsaturated monomer improves the compatibility when the composition of the present invention is applied repeatedly. There is.

  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, 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 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 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 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.

  When using the said water-soluble acrylic resin, as the compounding quantity, it can exist in the range of 1-30 mass% in the resin solid content contained in main ingredient component (I), Preferably it is in the range of 1-20 mass%. .

  In the present invention, the main component (I) can be stably stored, and the water-based metallic base coating composition obtained by mixing with the later-described diluent component (II) has a good finished appearance with no occurrence of unevenness or sagging. The main component (I) contains a viscosity modifier so that a coating film can be formed.

  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, the polyacrylic acid viscosity modifier is good from the viewpoint of the orientation of the glitter pigment (C) in the metallic 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.

  As a compounding quantity of a polyacrylic-acid type viscosity modifier, it is 0.5-20 mass% on the basis of resin solid content contained in main ingredient component (I), Preferably it is about 1-10 mass%.

  The solid content concentration of the main component (I) is generally adjusted in the range of 10 to 50% by mass, preferably 15 to 40% by mass, from the viewpoint of coating workability and concealing property and finished appearance. Yes.

  The viscosity of the main component (I) is not particularly limited, but is preferably 100 to 3000 mPa · sec, in view of storage stability and miscibility with the diluent component (II) described later. Can be in the range of 600-2000 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 (II) ≫
In the present invention, the diluent component (II) contains a viscosity modifier and water.

  In the present invention, the rheological properties of the aqueous metallic base coating composition can be controlled according to the coating environment by mixing the diluent component (II) with the main component (I) immediately before coating. By configuring the metallic base coating composition in this way, it is possible to form a metallic coating film that maintains the storage stability of each component, has no sagging, and has an excellent finished appearance without occurrence of unevenness. .

  As the viscosity modifier that can be contained in the diluent component (II), it can be appropriately selected from those exemplified in the description of the viscosity modifier contained in the main agent component (I).

  In the present invention, an inorganic viscosity modifier is suitable for the diluent component (II).

  As such inorganic viscosity modifiers, those known in the art can be used without limitation, and examples thereof include minerals such as layered silicates, and these can be natural, synthetic, or processed products. 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) manufactured by lay Products, trade name), "Laponite RD", "LaponiteRDS", "Laponite HW", "Laponite EP", "Laponite S482", "Laponite OG", "Laponite LV" , Product name) and the like.

  The effective component content of the inorganic viscosity modifier in the diluent component (II) is 0.1 to 3.0% by mass, preferably 0.3 to 2.0% based on the mass of the diluent component (II). The range of mass% is appropriate.

  The diluent component (II) is an aqueous resin, ultraviolet absorber, light stabilizer, polymer fine particle, surface conditioner, dispersion aid, preservative, silane coupling agent, antifoaming agent, curing catalyst, organic solvent, medium It may contain other components such as paint additives that are usually used in the preparation of water-based paints such as a compatibilizer.

  Further, the viscosity of the diluent component (II) is not particularly limited, but is preferably 10 to 300 mPa · sec from the viewpoint of storage stability and miscibility with the main ingredient component (II). Can be in the range of 10 to 100 mPa · sec.

<Silica particles (D)>
The aqueous metallic base coating composition of the present invention is characterized by containing silica particles (D) having an average particle size in the range of 0.1 to 25 μm.

  The silica particles (D) may have any shape such as spherical, granular, polyhedral, needle-like, spindle-like, rice-grained, flake-like, scale-like and plate-like, but the average particle size is less than 0.1 μm However, the difference in brightness depending on the film thickness of the metallic base coating film is greatly different. On the other hand, if the average particle diameter of the silica particles (D) exceeds 25 μm, the unevenness of the metallic base coating film becomes remarkable, which is not preferable.

  As a preferable average particle diameter of a silica particle (D), it exists in the range of 0.5-10 micrometers.

  Examples of such silica particles (D) include finely divided silica, colloidal silica, white carbon, finely divided silicic acid, diatomaceous earth, etc., “Syloid” series (trade name, manufactured by Grace Japan), “AEROSIL” series (product) Name, manufactured by Nippon Aerosil Co., Ltd.), "ACEMATT" series (trade name, manufactured by DEGUSSA), "Siricia" series, "Silo Hovic" series, "Syrosphere" series (above, trade name, Fuji Silysia Chemical Co., Ltd.) “Quartron” series (trade name, manufactured by Fuso Chemical Co., Ltd.) “Fine Seal” series (trade name, manufactured by Tokuyama Co., Ltd.) “NIPSIL” series (trade name, manufactured by Tosoh Silica Co., Ltd.) "Mizukasil" series (trade name, manufactured by Mizusawa Chemical Co., Ltd.).

  In this specification, the average particle diameter of the silica particles (D) is a volume-based average particle diameter (D50), and is a value of 50% of the particle size distribution measured by a laser diffraction particle size distribution measuring device.

  In the present invention, the silica particles (D) can be included in either the main component (I) or the diluent component (II).

≪Particle component (III) ≫
The water-based metallic base coating composition of the present invention may be a multi-component system in which the particle component (III) is further combined with the main component (I) and diluent component (II), that is, a three-component system. .

  The particle component (III) is preferably in a form containing the silica particles (D) from the viewpoint of the glittering feeling and transparency of the formed metallic base coating film.

  The active ingredient content of the silica particles (D) in the particle component (III) is 1 to 50% by mass, preferably 3 to 40% by mass based on the mass of the particle component (III).

  The particle component (III) preferably contains an aqueous resin in addition to the silica particles (D). When the particle component (III) contains an aqueous resin, there is an effect that the storage stability of the particle component (III) is improved.

  As the aqueous resin, conventionally known resins can be used without limitation, but it is preferable to use a urethane resin emulsion and an acrylic resin emulsion. As such urethane resin emulsion and acrylic resin emulsion, it is possible to use appropriate resin emulsions from those listed in the description of urethane resin emulsion (A) and acrylic resin emulsion (B) contained in the main component (I). it can.

  The solid content of the aqueous resin when the particle component (III) contains an aqueous resin is 1 to 300 parts by mass, preferably 10 to 200 parts by mass, based on 100 parts by mass of the silica particles (D). It is suitable to be.

If the amount of the aqueous resin contained in the particle component (III) is too large, the viscosity of the aqueous metallic base paint becomes high, and stirring may be difficult when the components (I) to (III) are mixed.
When the particle component (III) includes a urethane resin emulsion and an acrylic resin emulsion, the ratio is 5/95 to 95/5, preferably 30/70 to 70/30, as a solid content ratio of urethane resin emulsion / acrylic resin emulsion. It is desirable to be within the range.

  When the urethane resin emulsion is less than this range, the initial adhesion of the metallic base coating film is inferior. On the other hand, when the amount is too large, the viscosity of the coating becomes high, and stirring may be difficult when preparing the coating.

  The particle component (III) preferably contains a viscosity modifier as a part of the component. Thereby, the miscibility with the main ingredient component (I) and the diluent component (II) is good, and there is an effect that a metallic base coating film excellent in glitter feeling can be obtained.

  The viscosity modifier is not particularly limited, and can be appropriately selected from those exemplified in the description of the viscosity modifier contained in the main component (I). Use of an agent is suitable from the viewpoint of the storage stability of the particle component (III).

  The effective component content of the viscosity modifier in the particle component (III) is 0.1 to 20% by mass, preferably 0.1 to 10% by mass, based on the mass of the particle component (III). is there.

  The particle component (III) preferably contains a polyether-modified silicone compound. This is because there is an effect on the conformability of repeated coating of the aqueous metallic base coating composition a plurality of times.

  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 may be used in an amount of 0.5 to 40% by mass, preferably 2.0 to 20% by mass based on the mass of the silica particles (D). Suitable from the point of sex.

  In the embodiment in which the silica particles (D) are stored separately as the particle component (III), it is suitable that the particle component (III) contains an organic solvent. This is from the viewpoint of the storage stability of the particle component (III). In addition, the spout of the container for storing the particle component (III) may have a silica film due to the silica particles (D), which causes the film-forming property of the coating film with the aqueous metallic base paint. Although a problem may occur, the phenomenon is improved by including an organic solvent in the particle component (III).

  As the organic solvent, a conventionally known organic solvent can be used, but in the present invention, a hydroxyl group-containing organic solvent having a boiling point of 150 ° C. or less and an aqueous solubility of 10 or more in the organic solvent (B) is preferable.

  Examples of such solvents include alcohol 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 Ethylene glycol ether organic solvents such as 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 can be used alone or in combination of two or more.

  As content of the organic solvent in particle | grain component (III), it is 1-300 mass% on the basis of the mass of a silica particle (D), Preferably it exists in the range of 10-200 mass%.

  Particle component (III) includes particles other than silica particles (D), water, UV absorbers, light stabilizers, dispersion aids, preservatives, silane coupling agents, antifoaming agents, curing catalysts, neutralizing agents, etc. In addition, other components such as paint additives that are usually used in the preparation of water-based paints may be included.

  The viscosity of the particle component (III) is not particularly limited, but is 10 to 2000 mPa · sec from the viewpoint of storage stability of the particle component (III) and coating workability of the aqueous metallic base coating composition. Preferably it can exist in the range of 10-1000 mPa * sec.

≪Water-based metallic base paint composition≫
In the present invention, the main component (I), the diluent component (II) and the particle component (III) used as necessary are stored separately, and the painter stirs and mixes each component immediately before painting. And the water-based metallic base coating composition of this invention can be prepared by adjusting a viscosity with water etc. as needed. 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 diluent component (II) in the aqueous metallic base coating composition can be appropriately adjusted depending on the coating environment and the like. Generally, the diluent is based on 100 parts by mass of the main component (I). The component (II) is in the range of 30 to 400 parts by mass, preferably in the range of 40 to 350 parts by mass, or the mass ratio of the main component (I), diluent component (II) and particle component (III) is generally the main component ( I) Diluent component (II) is 30 to 400 parts by weight, preferably 40 to 350 parts by weight, and particle component (III) is 0.01 to 105 parts by weight, 0.1 to 50 parts by weight, based on 100 parts by weight. In view of the appearance of the metallic coating film and the physical properties of the coating film, it is preferably within the range of 1 to 35 parts by mass.

  In the present invention, if necessary, curing agents such as polyisocyanate curing agent, block isocyanate curing agent, melamine curing agent, oxazoline curing agent, carbodiimide curing agent are used as the main component (I), diluent component (II) and particles. It can be included in any of the components (III) or used as a separate component.

  The solid content concentration of the aqueous metallic 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 concealability, and the finish. Suitable from the viewpoint of appearance.

  The viscosity of the aqueous metallic base coating composition at the time of coating is not particularly limited, but the coating workability is within the range of 50 to 800 mPa · sec, preferably 100 to 600 mPa · sec. It is good and is suitable from the viewpoint of the finished appearance of the metallic base coating film.

≪Painting≫
The aqueous metallic 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 metallic 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 10 to 60 μm is suitable.

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

  Moreover, you may use the water-based metallic 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 metallic base coating composition is applied, a top clear coating composition may be applied on the 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, a block polyisocyanate, a polyisocyanate or a 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, 23.2 parts of dimethylolpropionic acid, 14.5 parts of 1,4-butanediol and 120.1 parts of isophorone diisocyanate was charged in a polymerization vessel and reacted for 7 hours at 85 ° C. in a nitrogen stream with stirring 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.

<Manufacture of acrylic resin emulsion:>
Production Example 2
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, 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.

<Manufacture of aluminum pigment paste:>
Production Example 3
Aluminum pigment paste "Hydrolan 2156" (silica coated aluminum flake pigment paste, pigment content 60%) 45.5 parts, propylene glycol monomethyl ether 35 parts, phosphate group-containing resin solution (Note 1) 17.5 parts were added and stirred and mixed to obtain an aluminum pigment paste (C-1).
(Note 1) Phosphate group-containing resin solution: A mixed solvent 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, and the mixture is heated to 110 ° C. Heat, 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 2) 121.5 parts of a mixture comprising 15 parts, 12.5 parts of 2-methacryloyloxyethyl acid phosphate, 10 parts of isobutanol and 4 parts of t-butylperoxyoctanoate was added to the above mixed solvent over 4 hours, and t A mixture of 0.5 part of butyl peroxyoctanoate and 20 parts of isopropanol was added dropwise over 1 hour. Thereafter, the mixture was aged and stirred for 1 hour to obtain a phosphate group-containing resin solution having a solid content of 50%.
(Note 2) Phosphoric acid group-containing polymerizable monomer: 57.5 parts of monobutyl phosphoric acid and 41.1 parts of isobutanol are placed in a reaction vessel, and 42.5 parts of glycidyl methacrylate are added dropwise over 2 hours under air flow. The mixture was aged with stirring 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%.

Production Example 4
40.4 parts of aluminum pigment paste "Hydrolan 2156" (manufactured by Ecart Co., silica-coated aluminum flake pigment paste, pigment content 60%), 11.1 parts of "Nip seal E-1009", 31 parts of propylene glycol monomethyl ether in a stirring and mixing container Then, 15.5 parts of a phosphoric acid group-containing resin solution (Note 1) was added and mixed by stirring to obtain an aluminum pigment paste (C-2).

<Manufacture of base paint:>
Production Example 5
After 83.5 parts of the aluminum pigment paste (C-1) obtained in Production Example 3 was added to the stirring and mixing vessel and stirred for 1 hour, 150 parts of the urethane resin emulsion (A-1) obtained in Production Example 1 and further Mix 150 parts of the acrylic resin emulsion (B-1) obtained in Production Example 2, add 17.8 parts of “Primal ASE60” (Note 3), continue stirring for 1 hour, and adjust the pH with dimethylethanolamine. After that, deionized water was added to obtain a base paint (I-1) having a solid content of 20%. When the viscosity and pH of this base coating material (I-1) were measured according to the method described in the specification, they were 1000 mPa · sec and 8.0, respectively.
(Note 3) “Primal ASE 60”: trade name, manufactured by Rohm and Haas, polyacrylic acid thickener, acid value 270 mg KOH / g, active ingredient 28%.

Production Example 6
After adding 83.5 parts of the aluminum pigment paste (C-2) obtained in Production Example 4 to the stirring and mixing vessel and stirring for 1 hour, 150 parts of the urethane resin emulsion (A-1) obtained in Production Example 1 and further Mix 150 parts of the acrylic resin emulsion (B-1) obtained in Production Example 2, add 17.8 parts of “Primal ASE60” (Note 3), continue stirring for 1 hour, and adjust the pH with dimethylethanolamine. After that, deionized water was added to obtain a base paint (I-2) having a solid content of 20%. When the viscosity and pH of the base paint (I-2) were measured according to the method described in the specification, they were 1500 mPa · sec and 8.0, respectively.

<Manufacture of diluent:>
Production Example 7
To the stirring and mixing vessel, 995 parts of water and 5 parts of “Laponite RD” (Note 4) were added and stirred and mixed to obtain diluent (II-1). The viscosity was 15 mPa · sec.
(Note 4) “Laponite RD”: trade name, manufactured by Rochwood Additives Limited, inorganic thickener, synthetic hectorite,
Production Example 8
980 parts of water, 5 parts of “Laponite RD” (Note 4), and 15.0 parts of “Nip seal E-1009” were added to the stirring and mixing container, and the mixture was stirred and mixed to obtain diluent (II-2). The viscosity was 200 mPa · sec.

<Manufacture of particle-containing paint:>
Production Example 9
In a stirring and mixing vessel, 87 parts of water and 10 parts of “Nip seal E-1009” (Note 5) are stirred and mixed, 3 parts of “Primal ASE 60” is added, and stirring is continued for another hour, and the pH is adjusted with dimethylethanolamine. After that, deionized water was added to obtain a particle-containing paint (III-1).
When the viscosity and pH of the particle-containing paint (III-1) were measured according to the method described in the specification, they were 2000 mPa · sec and 8.0, respectively.
(Note 5) “Nip seal E-1009”: trade name, manufactured by Tosoh Silica, average particle diameter of 1.5 μm, silicon dioxide.

Production Examples 10 to 18
Particle-containing paints (III-2) to (III-10) were obtained in the same manner as in Production Example 9 except that the composition was as shown in the following table.

(Note 6) “ACEMATOKK607”: trade name, manufactured by Evonik Degussa, average particle size 2.5 μm, silicon dioxide,
(Note 7) “Syloid C305”: trade name, manufactured by Grace Japan, average particle size 5.0 μm, silicon dioxide,
(Note 8) “ACEMATTTS100”: trade name, manufactured by Evonik Degussa, average particle size 10.0 μm, silicon dioxide,
(Note 9) “MIN-U-SIL30”: trade name, U.V. S. Manufactured by SILICACOMPANY, average particle size 30.0 μm, silicon dioxide,
(Note 10) “AEROSILR-972”: trade name, manufactured by Nippon Aerosil Co., Ltd., average particle size 0.02 μm, silicon dioxide,
(Note 11) “HI-DISPERA-512”: trade name, manufactured by Gifu Shellac, average particle size of 5.0 μm, polyethylene.
(Note 12) “BYK-348”: trade name, manufactured by BYK-CHEMIE, polyether-modified silicone compound, active ingredient 100%
<Manufacture of diluted paint:>
Examples 1-18 and Comparative Examples 1-4
Base paints (I-1) to (I-2), diluents (II-1) to (II-2), and particle-containing paints (III-1) to (III-10) having the composition shown in the following table The mixture was sufficiently mixed by hand stirring to obtain diluted paints (D-1) to (D-22). The table also shows the viscosity of each diluted paint. Viscosity was measured according to the method described in the specification, and after 5 minutes had elapsed after mixing the base paint, diluent and particle-containing paint.

<Creation of evaluation coated plate for evaluation of blur characteristics:>
Degrease an electrodeposited door panel (approx. 90 x 70 cm) with isopropyl alcohol, and apply “Letane PG Hybrid Eco Filler” (trade name, 2 component urethane primer surfacer manufactured by Kansai Paint Co., Ltd.) to a dry film thickness of 50 μm. The entire door panel was spray-coated, dried at 60 ° C. for 20 minutes, polished and degreased with P600 paper. After that, spray the entire surface of the door panel with a commercially available organic solvent-based metallic base paint so that the dry film thickness is 15 μm. After 5 minutes, clear paint “Letan PG Eco Clear HX (Q)” (trade name, Kansai Paint) A two-component urethane clear containing a hydroxyl group-containing resin and a polyisocyanate) was spray-coated on the entire surface of the door panel to a dry film thickness of 40 μm and dried at 60 ° C. for 20 minutes to prepare a door panel having an old coating film.

  The old paint film on the door panel was lightly polished with P1500 paper and degreased with isopropyl alcohol. A black and white masking paper having a size (10 cm × 10 cm) was attached to the end of the door panel in the longitudinal direction, and assumed to be a repair site. The part assumed to be a repair site is thick until the black and white masking paper is completely covered (dry film thickness of about 15 μm), and gradually increases from the outer periphery of the repair site on the black and white masking paper to about 2/3 of the door panel longitudinal direction. Film thickness gradient coating was performed using each of the diluted paints (D-1) to (D-22) so that the film thickness was reduced. The minimum film thickness at this time is about 2 μm. After applying each of the diluted paints (D-1) to (D-22), an interval of 5 minutes is left, and the clear paint “Letane PG Eco Clear HX (Q)” (trade name, manufactured by Kansai Paint, hydroxyl-containing resin and poly A two-component urethane clear containing isocyanate) was spray-coated on the entire door panel so that the dry film thickness was approximately 40 μm, and dried at 60 ° C. for 20 minutes to obtain an evaluation coating plate.

<Evaluation test:>
Examples 19 to 36 and Comparative Examples 5 to 8
With respect to the test coated plate prepared as described above, an evaluation test was performed on the following items. The results are shown in the table.

(1) Glossy sensation consistency: The light source for toning in a dark room with respect to the radiance sensation caused by the difference in aluminum orientation between the repaired part (thick film part) and the peripheral part (thin film part) of each evaluation coating plate Visual evaluation was performed from the direction of skewness (diagonal direction) while illuminating the evaluation coated plate with a product name (luminous, manufactured by Kansai Paint).
A: There is no difference in brightness between the repaired part and the peripheral part.
○: A slight difference in brightness between the repaired part and the peripheral part is observed, but it is within an allowable range.
Δ: A difference in brightness between the repaired part and the peripheral part is seen, and there is a sense of incongruity.
X: The difference in brightness between the repaired part and the peripheral part is remarkably different from each other.
(2) Unevenness: Visual evaluation of metallic unevenness of the repaired portion (thick film portion) 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.
(3) ΔE * value: The color of each evaluation coating plate was measured from the right end at a light receiving angle of 75 ° corresponding to the scuffing direction using a spectrocolorimeter CM-512m3 (trade name, manufactured by Minolta) at intervals of 3 cm. The numerical value in the table is the maximum value of ΔE * between the repair site and the peripheral site. ΔE * is better as the value is lower, and if ΔE * is within 2.0, it is in a range where there is no sense of incongruity in blur painting, and is suitable for the purpose of the present invention.
(4) IV value: The IV value of the repaired part of each evaluation coated plate was measured using Alcope LMR-200 (manufactured by Kansai Paint Co., Ltd., laser type metallic feeling measuring device). The lower the IV value, the lower the front luster and the greater the effect of controlling the aluminum orientation by the particle-containing paint.
(5) Overview of coating film: The coating film surface of each evaluation coated plate 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.
(6) Concealing property: The base concealing property at the stage where each diluted paint was applied by two-stage spray coating was visually evaluated.
A: The base is completely hidden.
○: The substrate is slightly transparent.
Δ: The base can be seen through.
X: The groundwork shows through violently.
(7) Transparency: The color (turbidity) of each evaluation coated plate was visually evaluated.
A: The transparency of the coating film is high and there is no turbidity.
○: Transparency of the coating film is slightly low and turbidity is slightly observed.
Δ: The transparency of the coating film is low and turbidity is observed.
X: The transparency of the coating film is remarkably low, and the influence of turbidity on the color is great.
(8) Water resistance: Each evaluation coated plate was immersed in warm water at 40 ° C. for 10 days, and then the coating surface was observed.
A: Very good B: Good B: The coating film is swollen.
X: The coating film swells and abnormalities such as swelling and whitening are observed.
(9) Initial adhesion: Cut each evaluation coating plate with a cutter so as to reach the substrate, make 100 goby meshes with a size of 1 mm x 1 mm, stick adhesive cellophane tape on the surface, and at 20 ° C The remaining number of the goby eye coating after the tape was abruptly peeled was examined.
◎: 100 remaining ◯; 99-90 remaining △; 89-41 remaining ×; 40 or less remaining (10) Overcoat familiarity: spray coating, and then air blowing until no gloss occurs Was performed four times, and the conformability of the paint when it was repeatedly applied 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.

Claims (8)

A multi-component aqueous metallic base coating composition comprising a combination of a main component (I) and a diluent component (II),
The main agent component (I) contains a urethane resin emulsion (A), an acrylic resin emulsion (B), a glitter pigment (C) and water, and the diluent component (II) contains a viscosity modifier and water. And
A multi-component aqueous metallic base coating composition comprising silica particles (D) in the composition, wherein the average particle size of the silica particles (D) is in the range of 0.1 to 25.0 μm. The composition according to claim 1, wherein the acrylic resin emulsion (B) contains a polyvinyl compound having at least two polymerizable unsaturated groups in one molecule as a copolymerization component. The composition according to claim 1 or 2, wherein the glitter pigment (C) is silica-coated aluminum flakes. A multi-component aqueous metallic base coating composition obtained by further combining a particle component (III) in addition to the main component (I) and diluent component (II), wherein the particle component (III) is silica particles (D) And the composition according to any one of claims 1 to 3, comprising water. The mass ratio of the main agent component (I) and the diluent component (II) is such that the diluent component (II) is in the range of 30 to 400 parts by mass based on 100 parts by mass of the main agent component (I). The composition of any one of these. The mass ratio of the main component (I), the diluent component (II) and the particle component (III) is 30 to 400 parts by mass of the diluent component (II) based on 100 parts by mass of the main component (I). The composition according to claim 4, wherein (III) is in the range of 0.1 to 105 parts by mass. A repair coating method using the composition according to any one of claims 1 to 6. A repair coating method comprising applying a clear coating after coating the composition according to any one of claims 1 to 6.