JP2003226843A - Water-based metallic coating material and method for forming double-layer coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a water-based metallic coating material capable of forming a metallic coating film of good design with favorable glitter feeling in a double- layer coating film composed of the metallic coating film and a clear coating film formed by 2-coat-1-bake system, wherein a metallic pigment in the metallic coating film is not intermingled with the clear coating film as the upper layer, and to provide a method for forming such a double-layer coating film by the 2-coat-1-bake system (2C1B) using the water-based metallic coating material. <P>SOLUTION: The water-based metallic coating material comprises (A) a thermosetting resin composition, (B) the metallic pigment, (C) infusible crosslinked resin particles 30-130°C in glass transition temperature and (D) a metal silicate. The method for forming the double-layer coating film by the 2C1B comprises the steps of coating a substrate with the water-based metallic coating material, coating the resulting uncured coating surface with a clear coating material, preferably a high-solid one, and then heating to subject both the coating films to simultaneous crosslinking curing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallic coating formed by a two-coat-one-bake method (2C1B) in which a water-based metallic paint and a clear paint are applied by wet-on-wet, and then both coatings are simultaneously cured by heating. The metallic pigment in the metallic coating film in the multilayer coating film consisting of the coating film and the clear coating film does not mix with the clear coating film of the upper layer, and a metallic coating film with excellent glitter and glitter is provided. The present invention relates to an aqueous metallic paint to be formed and a method for forming a multilayer coating film by 2C1B using the same.

[0002]

2. Description of the Related Art Aqueous metallic paints prepared by mixing and dispersing a resin composition and a metallic pigment in water are already known, and are widely used as top coat paints for automobile outer panels. However, this water-based metallic coating is suitable for resource saving and pollution control, but when a clear coating (particularly high solid content type clear coating) is applied to the uncured coating surface, a mixed layer occurs between the layers of both coatings, It has a defect that the glittering metallic feeling is reduced and the designability is deteriorated. The occurrence of such a defect is fatal as a top coating material for automobile outer panels, and there is a strong demand for an urgent solution.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned defects and meet these needs, and it is a design which does not mix with a clear coating film as an upper layer and has a good glitter feeling as glitter. It is an object of the present invention to develop a novel water-based metallic paint that forms a metallic coating film having excellent properties and a method for forming a multilayer coating film composed of a metallic coating film and a clear coating film.

As a result of earnest studies, the present inventors have found that in addition to a thermosetting resin composition and a metallic pigment, non-melting type crosslinked resin particles having a glass transition temperature of 30 to 130 ° C. and a metal silicate are contained. It has been found that the water-based metallic coating composition can achieve the above-mentioned object, and completed the present invention. As a result, even if a clear coating such as a high solid content type is applied to the uncured coating surface of the water-based metallic coating, there is no intermixing between the layers of both coatings, and the design is good with a glittering feeling that is good. It became possible to form a metallic coating film.

According to the present invention, however, the thermosetting resin composition (A), the metallic pigment (B), the non-melting type crosslinked resin particles (C) having a glass transition temperature of 30 to 130 ° C. and the metal silicate. An aqueous metallic coating material (hereinafter referred to as "present coating material") containing (D) is provided.

Furthermore, the present invention is a multi-layer coating film by a two-coat one-bake system characterized in that after coating a clear coating on the uncured coating surface of the present coating composition, both coating layers are simultaneously heated to crosslink and cure. A forming method (hereinafter referred to as “this method”) is also provided.

The present paint and the present method will be described in detail below.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present coating composition has a thermosetting resin composition (A), a metallic pigment (B) and a glass transition temperature of 30.
It is a water-based metallic paint characterized by containing non-melting type crosslinked resin particles (C) and metal silicate (D) at ˜130 ° C.

The thermosetting resin composition (A) is a resin component which constitutes the continuous phase of the coating film formed by the present coating composition. This composition may be liquid or particulate at room temperature, It is preferable that it becomes liquid when heated during formation.

Specifically, thermosetting coating resins which are known per se and which can be dissolved or dispersed in water can be used. For example, an acrylic resin in which a hydrophilic group such as a carboxyl group and a crosslinking functional group such as a hydroxyl group coexist in one molecule,
One or more base resins selected from vinyl resins, polyester resins, urethane resins, etc. and hydrophobic or hydrophilic alkyl etherified melamine resins that react with these crosslinkable functional groups, blocked polyisocyanate compounds, etc. A resin composition containing the above crosslinking agent can be preferably used.
The composition ratio of these base resin and crosslinking agent will be described later.

The metallic pigment (B) is a pigment for imparting a glittering brilliance and light coherence to the coating film formed by the present paint, and for example, flaky aluminum, vapor-deposited aluminum, aluminum oxide. , Oxybismuth chloride [eg Engelhard Asia
Pacific Inc. Product name, "Mearli
te Radiant Pearl STL "," Me
arlite Radiant Pearl SU
Q ”,“ BBT ”(tentative name) and the like], mica, titanium oxide-coated mica, iron oxide-coated mica, mica-like iron oxide and the like. The size of these metallic pigments ranges from 1 to 1 in the longitudinal direction.
The thickness is preferably 30 μm and the thickness is 0.001 to 1 μm.

In particular, the thickness of the metallic pigment (B) is usually 0.1 to prevent mixing with the upper clear coating film.
Although a coating with a thickness of about 0.3 μm is often used, this coating has a mixed coating with an upper clear coating film even if a coating with a thickness of 0.4 to 0.6 μm or more is used. There is an effect that it is possible to further improve the glitter feeling. The mixing ratio of the metallic pigment (B) is 0.5 to 40 parts by weight per 100 parts by weight (solid content) of the thermosetting resin composition (A) and the non-melting crosslinked resin particles (C) described below. Is suitable.

The non-melting type crosslinked resin particles (C) having a glass transition temperature of 30 to 130 ° C. are three-dimensionally crosslinked and hardened resin particles, and are dissolved in water contained in the coating composition and further in an organic solvent. In the cured coating film formed by the present coating composition, which does not mix with the thermosetting resin composition (A) and does not melt in the heating step for curing the coating film. Exists in the form of particles.

By containing the resin particles (C), it is possible to prevent the uncured coating film of the present coating composition from mixing with the clear coating film coated on the coating surface, and as a result, the glittering feeling is good. It is now possible to form metallic coatings with excellent design.

The non-melting type crosslinked resin particles (C) are, for example, 1 selected from isobornyl (meth) acrylate, cyclohexyl (meth) acrylate and styrene.
It can be obtained by an aqueous emulsion or aqueous suspension polymerization method by using one or more polymerizable monomers having a high glass transition temperature, and if necessary, other polymerizable monomers in combination. The composition ratio of the polymerizable monomer having a high glass transition temperature is 5 to 100% by weight based on the total weight of the polymerizable monomer components for obtaining the non-melting type crosslinked resin particles (C), Particularly, the range of 30 to 90% by weight is suitable.

As the other polymerizable monomer, a polyfunctional polymerizable monomer having two or more polymerizable unsaturated bonds in one molecule, a hydroxyl group-containing polymerizable monomer, a carboxyl group-containing polymerizable monomer. Examples thereof include a monomer, a glycidyl group-containing polymerizable monomer, and a non-functional polymerizable monomer that does not contain these functional groups.

The polyfunctional polymerizable monomer is a compound having two or more, preferably 2 to 4 polymerizable unsaturated bonds in one molecule and is effective for three-dimensionally crosslinking the resin particles. Is. Specifically, ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, 2-butyl-2-ethyl-1,
3-propanediol, diethylene glycol, polyethylene glycol, cyclohexanedimethanol, tricyclodecane dimethanol, bisphenol A, bishydroxyphenylmethane, bishydroxyphenyl ether, hydrogenated bisphenol A, hydrogenated bishydroxyphenylmethane, glycerin, trimethylolpropane , Pentaerythritol, dipentaerythritol, polyhydroxy compounds such as tris (2-hydroxyethyl) isocyanuric acid, or polyacrylates and polymethacrylates of these modified with ethylene oxide, propylene oxide, ethylene oxide / propylene oxide mixture, Polyvinyl ether compound; divinylbenzene, allyl methacrylate, methylenebisacrylamide, dibi Nylethylene urea, triallyl cyanurate, 2-hydroxy-1-acryloxy-3-methacryloxypropane, di (meth) acryloyloxyethyl acid phosphate and the like can be mentioned. As a commercially available product of such a polyfunctional polymerizable monomer,
For example, Kayarad HX-220, 620, R-6
04, MANDA (Nippon Kayaku Co., Ltd., trade name)
Etc. can be mentioned.

The composition ratio of the polyfunctional polymerizable monomer is 20% by weight or less, and particularly preferably 0. 0% or less, based on the total weight of the polymerizable monomer components for obtaining the non-melting type crosslinked resin particles (C). 1-1
A range of 0% by weight is suitable.

The hydroxyl group-containing polymerizable monomer is a compound having at least one hydroxyl group and at least one polymerizable unsaturated bond in one molecule, and examples thereof include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. 2 to 2 carbon atoms such as hydroxypropyl and hydroxybutyl (meth) acrylate
Examples thereof include monoesters of 0 glycol and (meth) acrylic acid. When a hydroxyl group-containing polymerizable monomer is used in combination, hydroxyl groups can be introduced into the non-melting type crosslinked resin particles (C), and this reacts with the crosslinking agent of the thermosetting resin composition (A) to provide a stronger coating film. Are more preferable because they can be formed.

The composition ratio of the hydroxyl group-containing polymerizable monomer is 40% by weight or less, particularly 1 to 20 based on the total weight of the polymerizable monomer components for obtaining the non-melting type crosslinked resin particles (C).
A range of weight% is suitable.

The carboxyl group-containing polymerizable monomer has one carboxyl group and one polymerizable unsaturated bond in each molecule.
It is a compound having at least one, and examples thereof include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, mesaconic acid, and their anhydrides and half ester compounds. The composition ratio of the carboxyl group-containing polymerizable monomer is in the range of 20% by weight or less, particularly 10% by weight or less, based on the total weight of the polymerizable monomers for obtaining the non-melting type crosslinked resin particles (B). The inside is suitable.

The glycidyl group-containing polymerizable monomer is a compound having at least one glycidyl group and at least one polymerizable unsaturated bond in one molecule. For example, glycidyl acrylate
And glycidyl methacrylate. The composition ratio of the glycidyl group-containing polymerizable monomer is in the range of 20% by weight or less, particularly 10% by weight or less, based on the total weight of the polymerizable monomers for obtaining the non-melting type crosslinked resin particles (C). The inside is suitable.

The non-functional polymerizable monomer is a compound that does not contain the above-mentioned functional group and has one polymerizable unsaturated bond in one molecule. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth)
Acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth)
(Meth) acrylic acid such as acrylate and 1 to 2 carbon atoms
(2) mono-esterified product with linear or branched aliphatic monovalent alcohol; (meth) acrylic acid such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, etc. and C2-18 Alkoxyester of N; N-
Dimethylaminoethyl (meth) acrylate, N, N-
Diethylaminoethyl (meth) acrylate, Nt-
Aminoacrylic monomers such as butylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate; (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth ) Acrylamide, N-butyl (meth) acrylamide, N-
(Meth) acrylamide-based monomers such as dimethyl (meth) acrylamide; styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl acetate, “Veova 9”, “Veova 10” (all are oiled shell epoxies) , Vinyl chloride, etc. The composition ratio of the non-functional polymerizable monomer is 95% by weight or less, particularly 10 to 70% by weight, based on the total weight of the polymerizable monomer components for obtaining the non-melting type crosslinked resin particles (C). The range of is suitable.

The non-melting type crosslinked resin particles (C) are polymerizable monomers having the above-mentioned polymerizable monomer having a high glass transition temperature, and optionally other polymerizable monomers in combination. It can be obtained by polymerizing the components by an aqueous emulsion polymerization method or an aqueous suspension polymerization method.
Further, the thus obtained aqueous emulsion or the crosslinked resin particles contained in the aqueous suspension is subjected to evaporation or azeotropic distillation of water or precipitation or aggregation of the polymer (particles),
Those separated in the form of a solid (particulate) by a physical or chemical means such as a spray drying method can be preferably used.

The glass transition temperature (Tg) of the non-melting type crosslinked resin particles (C) is 30 to 130 ° C., preferably 40 to 10 ° C.
It is within the range of 0 ° C. T of non-melting type crosslinked resin particles (C)
When g is lower than 30 ° C., the glittering feeling of the multilayer coating film obtained by coating the clear coating on the uncured coating surface of the present coating is deteriorated, and it becomes difficult to form a metallic coating film having a good glitter feeling. On the other hand, when Tg is higher than 130 ° C., the finish appearance (occurrence of skin) of the single coating film of the coating composition itself is deteriorated, which is not preferable.

The glass transition temperature of the non-melting type crosslinked resin particles (C) is measured by the differential scanning calorimeter (DSC) "SS".
"C / 5200" (manufactured by Seiko Co., Ltd., trade name) in a sample made of aluminum [non-melting type crosslinked resin particles (C)]
Approximately 10 g was weighed, dried at 80 ° C. for 3 hours to remove water, then sealed, and placed under a nitrogen atmosphere at −50 to −15.
The measurement was performed by heating to 0 ° C. at a heating rate of 10 ° C./min.

As the metal silicate (D), lithium magnesium silicate sodium salt and the like can be preferably used in terms of composition. The metal silicate (D) can be easily obtained by, for example, purifying clay minerals such as hectorite and bentonite, or synthesizing them by a known method. The particles are flaky fine particles, and the lengthwise dimension is preferably 1 to 2 μm or less, and particularly preferably ultrafine particles of about 10 nm to 500 nm. As a corresponding commercial item, Laporte
Industries Ltd. Product name "Laponi"
te RD ”and the like.

This coating composition has the above-mentioned thermosetting resin composition (A), metallic pigment (B) and glass transition temperature of 30.
It is a water-based metallic paint characterized by containing non-melting type crosslinked resin particles (C) and metal silicate (D) at ˜130 ° C. Specifically, it can be obtained by mixing and dispersing these components in water. The blending ratio of each of these components can be arbitrarily selected according to the purpose.

For example, a thermosetting resin composition (A) comprising a base resin and a crosslinking agent and non-melting type crosslinked resin particles (C)
Based on the total solid weight of the thermosetting resin composition (A)
The base resin is 1 to 70% by weight, preferably 10 to 30% by weight, the crosslinking agent is 10 to 50% by weight, especially 15 to 35% by weight, and the non-melting type crosslinked resin particles (C) are 20 to 90% by weight. In particular, the range of 40 to 70% by weight is preferable.

The metal silicate (D) is added in an amount of 0.5 to 20 per 100 parts by weight (solid content) of the thermosetting resin composition (A) and the non-melting type crosslinked resin particles (C). Parts by weight,
In particular, the range of 1 to 10 parts by weight is suitable. The mixing ratio of the metallic pigment (B) is preferably 0.5 to 40 parts by weight per 100 parts by weight (solid content) of the thermosetting resin composition (A) and the non-melting type crosslinked resin particles (C). ing.

The present coating composition has the above-mentioned thermosetting resin composition (A), metallic pigment (B) and glass transition temperature of 30.
A water-based metallic paint containing non-melting type cross-linked resin particles (C) and metal silicate (D) at 130 ° C, and if necessary, solid color pigments, extender pigments, ultraviolet absorbers, and light stabilizers. It is also possible to add an anti-settling agent, a coating surface adjusting agent, an organic solvent, and other paint additives, and the present paint can be obtained by uniformly mixing these components with water.

The coating composition of the present invention can be applied directly to the outer panel of automobiles such as passenger cars, trucks, auto-buses and buses made of metal or plastic, the outer panel of household electric appliances, and the like. It is preferable to apply an undercoat paint such as a cationic electrodeposition paint, an intermediate paint, and the like in advance, and apply the paint to an object to be coated by curing these paint films. Of these, it is preferable to subject the metal-coated article to chemical conversion treatment with phosphate, chromate, or the like in advance. Also,
As the undercoat paint and the intermediate paint, those known per se can be used.

The present coating composition is used for these objects (undercoating material,
Furthermore, it can be applied by electrostatic coating, airless spray, air spray, etc. The coating film thickness is generally 5 to 30 μm, particularly 10 to 25 μm, based on the cured coating film. This coating film can be crosslinked and cured by heating at 100 to 180 ° C. for 10 to 40 minutes.

In the single coating film of the present coating composition, the metallic pigment is oriented uniformly on the coating surface and parallel to the coating surface, and the glittering and glittering feeling is excellent and the flip-flop (F
F) Good property.

The present method is characterized in that the present coating is applied, the uncured coating surface is applied with a clear coating, and then the coating is heated to crosslink and cure both coatings simultaneously. A coating film forming method.

The clear coating material is preferably a thermosetting coating material that forms a colorless transparent or colored transparent coating film. Specifically, it contains a thermosetting resin composition and an organic solvent, and if necessary, a coloring pigment. Examples include paints containing a metallic pigment, an ultraviolet absorber, and the like.

Examples of the thermosetting resin composition include acrylic resin, polyester resin, alkyd resin, fluororesin, urethane resin and silicone having a crosslinkable functional group such as hydroxyl group, carboxyl group, silanol group and epoxy group. Base resin such as containing resin and melamine resin, urea resin, (block) polyisocyanate compound, epoxy compound or resin, carboxyl group-containing compound or resin, acid anhydride, alkoxysilane group which can react with these crosslinkable functional groups Examples thereof include compositions containing a compound or a crosslinking agent such as a resin.

Among these thermosetting resin compositions, an acrylic resin having a crosslinkable functional group such as a carboxyl group, a silanol group or an epoxy group, which forms a coating film excellent in acid resistance and scratch resistance. (Base resin) and epoxy compound or resin, carboxyl group-containing compound or resin,
It is preferable to use a composition comprising a crosslinking agent selected from acid anhydrides and the like.

In the present method, it is preferable to use, as the clear paint, a high solid content clear paint having a high solid content at the time of coating from the viewpoints of resource saving, environmental friendliness, improvement of coating efficiency and improvement of finish. . As the high solid content type clear, a clear coating composition having the following composition is particularly suitable, and these have a solid content of 45% by weight or more, preferably 60% by weight or more, more preferably 7% by weight at the time of coating.
It is within the range of 0 to 90% by weight.

High solid content clear coating (1): (a) contains a hydroxyl group-containing compound having a weight average molecular weight of 1000 or less and a hydroxyl value of 200 to 800 and (b) a polyisocyanate compound, and the ratio of both components is A high-solids clear coating having an NCO / OH molar ratio of 0.5 / 1 to 2.0 / 1.

The high solids clear coating composition (1) has a solids content of 70% by weight or more, particularly 75 to 9 when coated.
The coating can be applied within the range of 0% by weight, the viscosity of the coating at that time is low, and a coating having excellent finished appearance, coating hardness, acid rain resistance and scratch resistance can be formed.

The component (a) is not particularly limited in composition so long as it is a compound having a weight average molecular weight and a hydroxyl value within the above-mentioned ranges, but in particular, a carboxyl group-containing compound and an epoxy group-containing compound are used. It is preferable to use the ring-opening esterification reaction product (a-1) as the component (a) in order to achieve the object of the present invention.

The component (a-1) can be prepared by a ring-opening esterification reaction between the carboxyl group of the carboxyl group-containing compound and the epoxy group of the epoxy group-containing compound. Examples of the hydroxyl group contained in the component (a-1) include a hydroxyl group generated by ring opening of an epoxy group and a hydroxyl group introduced by another method.

The compound containing a carboxyl group is 1 in one molecule.
Or a compound having two or more carboxyl groups, for example, acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, octanoic acid, dodecanoic acid, palmitic acid, stearic acid, oleic acid, pivalic acid, versatic acid,
Monocarboxylic acids such as benzoic acid; polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetrahydrophthalic acid, phthalic acid, butanetricarboxylic acid, butanetetracarboxylic acid, trimellitic anhydride; Examples thereof include oxyacids such as glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, hydroxypivalic acid, dimethylolpropionic acid, dimethylolbutanoic acid, and gluconic acid, and their anhydrides are also applicable. Further, it is possible to use a product obtained by previously reacting these anhydrides with glycols. Specific examples thereof include a reaction product of trimethylolpropane and hexahydrophthalic anhydride, a reaction product of trimethylolpropane and succinic anhydride, and the like. Among these, by using a reaction product of an oxyacid or an anhydride having a hydroxyl group and a carboxyl group together, and a glycol, a large number of hydroxyl groups can be obtained (a-1).
It is preferable because it can be introduced into the component.

The epoxy group-containing compound is a compound having one or two or more epoxy groups in one molecule, and compounds known per se can be used. For example, the following compounds can be exemplified.

A) Glycidol.

(B) An epoxy group-containing compound obtained by an etherification reaction of a hydroxyl group-containing compound with epihalohydrin.

(C) An epoxy group-containing compound obtained by an esterification reaction between a carboxyl group-containing compound and epihalohydrin.

D) An epoxy group-containing compound obtained by reacting an unsaturated group with a peroxide. The glycidol of the above item a) is 2,3-epoxy-1-propanol, and is obtained, for example, by the reaction of allyl alcohol with benzoic acid or tungstic acid with hydrogen peroxide.

Examples of the hydroxyl group-containing compound include phenol, bisphenol A, bisphenol F, phenol novolac resin, orthocresol novolac resin, aromatic hydroxyl group-containing compounds such as bromide thereof; alicyclic group such as hydrogenated bisphenol A System hydroxyl group-containing compound; carbon number such as methanol and ethanol is 1
~ 20 aliphatic monoalcohols; ethylene glycol, propylene glycol, hexanediol, diethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, etc. Examples include system polyols. Epichlorohydrin can be preferably used as epihalohydrin. The etherification reaction between the hydroxyl group-containing compound and epihalohydrin can be carried out by a known method, and this reaction gives the component (b). As commercially available products corresponding to the component (b), "Denacol EX-313" and "Denacol E" manufactured by Nagase & Co., Ltd.
"X-321", "Denacor EX-421", "Denacor EX-611" (all are trade names) and the like.

As the carboxyl group-containing compound and epihalohydrin in (c), for example, the carboxyl group-containing compound and epihalohydrin exemplified in the preparation of the component (a-1) can be preferably used. The esterification reaction between the carboxyl group-containing compound and epihalohydrin can be carried out by a known method, and this reaction yields component (c). As a commercially available product corresponding to the component (c), "CURDULA E10" (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.),
"Glidex N10" (trade name, manufactured by Exxon),
Examples include "Araldite PT910" (trade name, manufactured by Ciba Geigy).

Examples of the compound in (d) are commercially available products such as "Celoxide 2021" and "Celoxide 3000" (both are trade names) manufactured by Daicel Chemical Industries.
Among these compounds, an oxy acid is particularly preferably used among the carboxy group-containing compounds, and a glycidyl ester having a hydrophobic group is particularly preferably used among the epoxy group containing compounds.

The ring-opening esterification reaction of the carboxyl group-containing compound and the epoxy group-containing compound for preparing the component (a-1) proceeds even at room temperature, but for example, 10
Heat to 0-160 ° C, preferably 115-150 degrees,
It is preferable to carry out without catalyst.

The component (a) has a weight average molecular weight of 1
000 or less, preferably 300 to 700, having a hydroxyl value of 2
It is a compound having two or more hydroxyl groups in one molecule of 00 to 800, preferably 300 to 600. In the component (a), if the weight average molecular weight is more than 1000, high solid differentiation becomes difficult, and if the hydroxyl value is less than 200, the curability is poor, while if it is more than 800, the compatibility with the polyisocyanate compound is reduced. Is not preferred.

The polyisocyanate compound as the component (b) is a compound having two or more free isocyanate groups (unblocked) in one molecule, and those known per se can be used. For example, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate
, Dimer acid diisocyanate, lysine diisocyanate, and other aliphatic polyisocyanates; hydrogenated xylylene diisocyanate, cyclohexylene diisocyanate, methylene bis (cyclohexyl isocyanate)
A) alicyclic polyisocyanates such as isophorone diisocyanate; tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate. Aromatic polyisocyanates such as tetramethyl xylylene diisocyanate and naphthalene diisocyanate; 2-isocyanatoethyl-2,6-diisocyanatocaproie
3-isocyanatomethyl-1,6-hexamethylene diisocyanate, 4-isocyanatomethyl-1,8-
Trivalent or higher valent organic polyisocyanate compounds such as octamethylene diisocyanate (commonly called triaminononane triisocyanate); Polyisocyanate having two or more isocyanate groups in one molecule thereof Compound 2
Polymers or trimers; polyisocyanate compounds having two or more isocyanate groups in one molecule and polyhydric alcohol, low molecular weight polyester resin, water or the like under the condition of excess isocyanate groups. Examples thereof include prepolymers obtained by urethanization reaction.

In the component (b), a block polyisocyanate compound in which an isocyanate group is blocked can be used in combination with these unblocked polyisocyanate compounds.

The block polyisocyanate compound is a compound in which the isocyanate group of the above polyisocyanate compound is blocked with a blocking agent. As a blocking agent,
Examples thereof include active methylene compounds such as phenols, oximes, lactams, alcohols, mercaptans and diethyl malonate. The proportion of these block polyisocyanate compounds is 50% by weight or less based on the total amount of the non-block polyisocyanate compounds,
A range of 30% by weight or less is particularly preferable. The number average molecular weight of the component (b) is preferably 2,000 or less, particularly preferably 200 to 1,000.

The high-solids clear coating composition (1) has the above-mentioned (a) weight average molecular weight of 1000 or less and a hydroxyl value of 20.
A hydroxyl group-containing compound of 0 to 800 and (b) a polyisocyanate compound are contained as essential components, and the ratio of both components is 0.5 based on the NCO / OH contained in each component. / 1 to 2.0 / 1, particularly preferably 0.7 / 1 to 1.5 / 1 is suitable.

The high-solids clear coating composition (1) can be prepared by blending the above-mentioned components (a) and (b) with the organic solvent in the above-mentioned ratio and mixing them uniformly. Further, it is possible to contain one kind or two or more kinds selected from (c) curing catalyst and (d) rheology control agent.

The curing catalyst as the component (c) is useful for promoting the crosslinking reaction of the coating film by the components (a) and (b). Specifically, tin octylate, dibutyltin di (2-ethylhexanoate), dioctyltin di (2-ethylhexanoate), dioctyltin diacetate, dibutyltin dilaurate, dibutyltin oxide, monobutyltin trioctate, Organotin compounds such as lead 2-ethylhexynoate and zinc octylate may be mentioned. Furthermore, acids such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, butylphosphoric acid and octylphosphoric acid, and amine neutralized products of these acids are preferable. The amount of the (c) curing catalyst used can be arbitrarily selected depending on the purpose of use, but 0.005 to 5 parts by weight, particularly 0.01 to 3 parts by weight, per 100 parts by weight of the total of the components (a) and (b). A range of parts by weight is suitable.

By adding a rheology control agent as the component (d), a high solid content clear paint (1)
Can be given thixotropy, and when high shear stress is applied during spray coating, the viscosity will be sufficiently lowered to facilitate spray coating work. In the case where a low shear stress is applied after being applied to the surface to be coated, the apparent viscosity can be increased. As a result, it is possible to prevent the occurrence of coating defects such as sagging and cissing when coating on a vertical surface to be coated or when baking onto that portion after coating, and it is possible to form a coating film with a good finished appearance. The effect is obtained. Examples of such rheology control agents include crosslinked polymer fine particles and polyurea compounds.

The crosslinked polymer fine particles are internally crosslinked particulate polymers which are hardly or completely insoluble in the above-mentioned components (a) and (b) and organic solvents and which can be stably dispersed in the clear coating composition. is there. Specifically, the three-dimensionally crosslinked non-melting type crosslinked resin particles (C) described in the present coating, and the resin particles in which water and the like are scattered and removed by a spray drying method or the like can be preferably used.

The compounding amount of the component (d) can be arbitrarily selected according to the purpose of use, but the total amount of the components (a) and (b) is 100.
A suitable range is 1 to 20 parts by weight, especially 2 to 10 parts by weight.

The high-solids clear coating composition (1) contains the above-mentioned components (a) and (b) as essential components, and is further selected from (c) a curing catalyst, (d) a rheology control agent, etc., if necessary. 1 or 2 or more of them may be contained, and in addition to these, solid color pigments, metallic pigments, light interference pigments, extender pigments, ultraviolet absorbers, light stabilizers, antisettling agents, coating surface adjusting agents. It is also possible to add other additives for paints, etc., and it can be obtained by uniformly mixing these components with an organic solvent.

The high solid content clear coating composition (1) is used as an organic solvent type high solid content coating composition, and as the organic solvent, various coating organic solvents such as aromatic or aliphatic hydrocarbon solvents, Alcohol-based solvents, ester-based solvents, ketone-based solvents, ether-based solvents and the like can be used. The high solid content clear paint (1) has a solid content concentration of 70 when applied.
Suitable is at least wt.%, Especially 75 to 90 wt.%.

The high-solids clear coating composition (1) contains (b) a polyisocyanate compound, which reacts relatively easily with the component (a) at room temperature.
It is preferable that the component (b) is used in a so-called two-liquid type in which the component (a) is separated in advance. In the case of a two-pack type, each group may be mixed and used immediately before use. In this case, in consideration of the reactivity with the component (b), the components other than the component (a) may be added to either the component (a) side or the component (b) side,
Alternatively, the third component can be used.

The high-solids clear coating composition (1) has a low viscosity such that it can be coated even when the solid content concentration at the time of coating is 70% by weight or more, and therefore airless spray, air spray, rotary atomizing coating method, etc. Can be easily painted by.
These coatings may be performed by applying static electricity. Excellent in atomization by these coating methods, smoothness, sharpness,
It is possible to form a coating film that is excellent in fleshness, and is also excellent in acid resistance, scratch resistance, and finished appearance (for example, gloss, fleshness, and sharpness). You can

High solids clear coating (2): (e) Hydroxyl group which is a reaction product of a carboxyl group-containing compound and an epoxy group-containing compound, and has a weight average molecular weight of 1,000 or less and a hydroxyl value of 200 to 800. Containing compounds,
A high-solids coating composition comprising (f) a polyisocyanate compound and (g) a melamine resin. Like the high solids clear coating (1), the high solids clear coating (2) may be applied with a solid content of 70% by weight or more, particularly 75 to 90% by weight at the time of coating. It is possible to form a coating film having a low viscosity at that time and excellent in finished appearance, coating film hardness, acid rain resistance and scratch resistance.

As the component (e), a ring-opening esterification reaction product (a-of a carboxyl group-containing compound and an epoxy group-containing compound, as exemplified in the high solid content clear paint (1), is used.
1) can be used preferably. Further, as the component (f), the polyisocyanate compound (b) exemplified in the high-solids clear coating composition (1) can be preferably used.

The (g) melamine resin is used as a crosslinking agent together with the (f) polyisocyanate compound, and is obtained by reacting a part or all of the amino groups (--NH ₂ ) in the melamine molecule with an aldehyde. Methylolated melamine resins (including those containing imino group> NH in the molecule). Formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like can be used as the aldehyde. Alkyl etherified melamine resins obtained by etherifying a part or all of the methylol groups of this methylolated melamine resin (including those containing imino group> NH in the molecule) are also melamine resins. Can be used as

Examples of the alcohol used for the etherification include methyl alcohol, ethyl alcohol, n
-Propyl alcohol, i-propyl alcohol, n-
Butyl alcohol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like have 1 carbon atom.
Examples include monovalent alcohols of 10 to 10. The number average molecular weight of the component (g) is preferably within the range of 150 to 3000. Among these, the use of a melamine resin containing an imino group is more preferable because it can improve the weather resistance of the coating film, especially the gloss retention.

The high-solids clear coating composition (2) is a reaction product of the above-mentioned (e) carboxyl group-containing compound and epoxy group-containing compound and has a weight average molecular weight of 100.
A compound having a hydroxyl value of 0 or less and 200 to 800,
The composition contains (f) a polyisocyanate compound and (g) a melamine resin, and the ratio of each of these components is not particularly limited and can be arbitrarily selected according to the purpose.
(E) component: 10 to 60% by weight, particularly 20 to 45% by weight, based on the total solid content of the components (e) to (g), (f)
Ingredients: 30-70% by weight, especially 35-60% by weight,
Component (g): 3 to 40% by weight, particularly 5 to 30% by weight is suitable, and a high solids clear coating composition (2) is prepared by blending these components in an organic solvent and mixing them uniformly. Can be prepared.

The high-solids clear coating composition (2) contains the above-mentioned components (e), (f) and (g), and optionally (c) a curing catalyst and (d) a rheology control agent. It is possible to contain one or more selected from the following. In addition to this, solid color pigments, metallic pigments, light interference pigments, extender pigments, ultraviolet absorbers, light stabilizers, antisettling agents, It is also possible to add a paint surface modifier, other additives for paints, etc., and it can be obtained by uniformly mixing these components with an organic solvent.

The high-solids clear coating composition (2) is used as an organic solvent-type high-solids coating composition, and as the organic solvent, various coating organic solvents such as aromatic or aliphatic hydrocarbon solvents, Alcohol-based solvents, ester-based solvents, ketone-based solvents, ether-based solvents and the like can be used. The high solid content clear paint (2) has a solid content concentration of 70 when applied.
Suitable is at least wt.%, Especially 75 to 90 wt.%.

The high-solids clear coating composition (2) contains (f) a polyisocyanate compound, which reacts relatively easily with the component (e) at room temperature.
It is preferable to use the so-called two-component type in the same manner as the high solid content clear paint (1).

The high-solids clear coating composition (2) has a low viscosity such that it can be coated even when the solid content concentration at the time of coating is 70% by weight or more, and therefore airless spray, air spray, rotary atomizing coating method, etc. Can be easily painted by.
These coatings may be performed by applying static electricity. Excellent in atomization by these coating methods, smoothness, sharpness,
It is possible to form a coating film having an excellent feeling of flesh. The high-solids clear coating composition (2) can form a cured coating film excellent in acid resistance, scratch resistance, and finished appearance (for example, gloss, flesh feeling, sharpness).

High solid content clear coating (3): (h) Compound which is a reaction product of a carboxyl group-containing compound and an epoxy group-containing compound and has a weight average molecular weight of 1,000 or less and a hydroxyl value of 200 to 800. , (I) weight average molecular weight of 500 to 6000, and hydroxyl value of 50 to 60
A high-solids coating composition containing a hydroxyl group-containing resin of 0, (j) a polyisocyanate compound, and (k) a melamine resin.

Like the high solids clear coatings (1) and (2), the high solids clear coating (3) has a solids content of 70% by weight or more, particularly 75 to 90% by weight at the time of coating. The coating can be applied within the range, and the viscosity of the coating at that time is low, and a coating having excellent finish appearance, coating hardness, acid rain resistance and scratch resistance can be formed.

As the component (h), the ring-opening esterification reaction product (a-of the carboxyl group-containing compound and the epoxy group-containing compound, as exemplified in the high solid content clear coating (1), is used.
1) can be used preferably. Further, as the component (j), the polyisocyanate compound (b) exemplified in the high-solids clear coating composition (1) can be preferably used. Further, as the (k) melamine resin, the (g) melamine resin exemplified in the high solid content clear paint (2) can be preferably used.

(I) Weight average molecular weight of 500 to 600
As the hydroxyl group-containing resin having a hydroxyl group value of 0 and a hydroxyl value of 50 to 600, polyester resins and acrylic resins having a weight average molecular weight and a hydroxyl value within the above ranges are particularly suitable.

The hydroxyl group-containing polyester resin can be produced by subjecting the carboxyl group of the polybasic acid and the hydroxyl group of the polyhydric alcohol to an esterification reaction. A polybasic acid is a compound having two or more carboxyl groups in one molecule, such as phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic acid, hexahydrophthalic acid. acid,
Examples thereof include het acid, maleic acid, fumaric acid, itaconic acid, trimellitic acid, pyromellitic acid, and their anhydrides. Polyhydric alcohol is a compound having two or more hydroxyl groups in one molecule, for example, ethylene glycol
1,2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, 1,2-hexanediol, 1,2-dihydroxycyclohexane, 3-ethoxypropane-1, Α-glycol such as 2-diol and 3-phenoxypropane-1,2-diol; neopentyl glycol, 2-methyl-1,3-
Propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-
1,3-propanediol, 2,2,4-trimethyl-
1,3-pentanediol, 2-butyl-2-ethyl-
1,3-propanediol, 2-phenoxypropane-
1,3-diol, 2-methyl-2-phenylpropane-1,3-diol, 1,3-propylene glycol,
1,3-butylene glycol, 2-ethyl-1,3-octanediol, 1,3-didoxycyclohexane,
1,4-butanediol, 1,4-dihydroxycyclohexane, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 3-methyl-
1,5-pentanediol, 1,4-dimethylol cyclohexane, tricyclodecane dimethanol, 2,2-
Dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate (this is an esterified product of hydroxypivalic acid and neopentyl glycol), bisphenol A, bisphenol F, bis ( 4-hydroxyhexyl) -2,2-propane, bis (4-hydroxyhexyl) methane, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,
4,8,10-tetraoxaspiro [5,5] undecane, diethylene glycol, triethylene glycol,
Glycerin, diglycerin, triglycerin, pentaerythritol, dipentaerythritol, sorbite
, Trimethylolethane, trimethylolpropane,
Examples thereof include ditrimethylolpropane and tris (2-hydroxyethyl) isocyanurate.

The introduction of hydroxyl groups into the polyester resin is carried out by, for example, polyvalent alcohol having 3 or more hydroxyl groups in one molecule.
This can be done by using the

The hydroxyl group-containing acrylic resin can be produced, for example, by copolymerizing a polymerizable monomer component containing a hydroxyl group-containing polymerizable monomer and an acrylic monomer by a conventional method.

The hydroxyl group-containing polymerizable monomer is a compound having at least one hydroxyl group and at least one polymerizable unsaturated bond in one molecule, and examples thereof include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. 2 to 2 carbon atoms such as hydroxypropyl and hydroxybutyl (meth) acrylate
Examples thereof include monoesters of 0 glycol and (meth) acrylic acid. The acrylic monomer is a monoester product of (meth) acrylic acid and a monovalent alcohol having 1 to 22 carbon atoms, such as methyl acrylate,
Methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate
G, hexyl acrylate, hexyl methacrylate,
Octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl (meth) acrylate, isobornyl ( (Meth) acrylate and the like.

In producing the hydroxyl group-containing acrylic resin,
Other polymerizable monomers other than the hydroxyl group-containing polymerizable monomer and the acrylic monomer can be used in combination. Other monomers include, for example, (meth) acrylic acid such as methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate, and methoxyethyl methacrylate, and C2-18. Alkoxy ester; N, N-dimethylaminoethyl acrylate
, N, N-dimethylaminoethyl methacrylate,
N, N-diethylaminoethyl acrylate, N, N-
Diethylaminoethyl methacrylate, Nt-butylaminoethyl acrylate, Nt-butylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylate, N, N-dimethylaminopropyl Amino acrylic monomers such as methacrylate; acrylamide, methacrylamide, N-methyl acrylamide, N
-Acrylamide monomers such as -methylmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-butylacrylamide, N-butylmethacrylamide, N-dimethylacrylamide and N-dimethylmethacrylamide; glycidyl acrylate , Glycidyl group-containing monomers such as glycidyl methacrylate;
Acrylic acid, methacrylic acid, maleic acid, itaconic acid,
Carboxylic group-containing polymerizable monomers such as fumaric acid, mesaconic acid and their anhydrides and half-esters; styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl acetate, “Veova 9”, “Veova” 10 "
(Each oil-shell epoxy), vinyl chloride and the like.

Further, a hydroxyl group-containing modified oligomer obtained by subjecting a polyhydric alcohol having two or more hydroxyl groups in one molecule to a ring-opening esterification reaction can also be applied as the hydroxyl group-containing resin. As commercial products corresponding to these,
For example, "TONE 0200 Polyol", "TO
NE 0301 Polyol "," TONE 0305
Polyol "(these are all manufactured by Union Carbide Co., trade name)," Plaxel 205 "," Plaxel 303 "," Plaxel 305 "(these are all products manufactured by Daicel Chemical Co., Ltd.).

The weight average molecular weight of the component (i) such as polyester resin and acrylic resin is 500 to 600.
0, preferably 1000 to 5200, hydroxyl value is 50 to
A value of 600, preferably 80 to 200, and an acid value of 15 or less, particularly 4 to 10, is suitable. When the weight average molecular weight of the component (i) is less than 500, the physical properties of the coating film deteriorate, and when it is more than 6000, high solidification becomes difficult, and when the hydroxyl value is less than 50, the curability of the coating film deteriorates. If it is larger, the compatibility with other components will be reduced, and thus both are not preferable.

The high-solids clear coating composition (3) is (h) a reaction product of a carboxyl group-containing compound and an epoxy group-containing compound, and has a weight average molecular weight of 1,000 or less.
A compound having a hydroxyl value of 200 to 800, (i) a weight average molecular weight of 500 to 6000, and a hydroxyl value of 50 to 6
00-containing hydroxyl-containing resin, (j) polyisocyanate compound and (k) melamine resin, and the ratio of each of these components is not particularly limited and can be arbitrarily selected according to the purpose. ) To (k), based on the total solid content of (h) component: 5 to 50% by weight, especially 10 to 4
0% by weight, component (i): 5 to 50% by weight, especially 10 to 4
0% by weight, component (j): 30 to 70% by weight, especially 40 to
60% by weight, component (k): 3 to 30% by weight, especially 7 to 2
The suitable amount is within the range of 5% by weight, and the high solids clear coating composition (3) can be prepared by blending these components in an organic solvent and mixing them uniformly.

The high-solids clear coating composition (3) may further contain, if necessary, one or more selected from (c) curing catalyst, (d) rheology control agent and the like. In addition to the above, it is possible to further include solid color pigments, metallic pigments, light interference pigments, extender pigments, ultraviolet absorbers, light stabilizers, anti-settling agents, surface control agents, and other paint additives. It can be obtained by uniformly mixing these components with an organic solvent.

The high-solids clear coating composition (3) is used as an organic solvent type high-solids coating composition, and as the organic solvent, various coating organic solvents such as aromatic or aliphatic hydrocarbon solvents, Alcohol-based solvents, ester-based solvents, ketone-based solvents, ether-based solvents and the like can be used. The high solid content clear paint (3) has a solid content concentration of 70 when applied.
Suitable is at least wt.%, Especially 75 to 90 wt.%.

The high-solids clear coating composition (3) contains the (j) polyisocyanate compound, which reacts relatively easily with the (h) and (i) components at room temperature. Similar to the minute clear coating composition (1), it is preferably used in the so-called two-component type.

The high-solids clear coating composition (3) has a low viscosity such that it can be coated even when the solid content concentration at the time of coating is 70% by weight or more, and therefore airless spray, air spray, rotary atomization coating method, etc. Can be easily painted by.
These coatings may be performed by applying static electricity. Excellent in atomization by these coating methods, smoothness, sharpness,
It is possible to form a coating film having an excellent feeling of flesh. The high-solids clear coating composition (3) can form a cured coating film excellent in acid resistance, abrasion resistance, and finished appearance (for example, gloss, flesh feeling, and sharpness).

In this method, the present coating composition (water-based metallic coating composition) is applied to an object to be coated, and the uncured coating surface is coated with a clear coating composition, particularly preferably a high solid content type clear coating composition. It is a method of forming a coating film.

Cationic electrodeposition coatings on the outer panels of automobiles such as passenger cars, trucks, auto-buses, buses, etc. made of metal or plastic, on the outer panels of household electric appliances, etc., or directly on these articles. An undercoat paint and an intermediate coat paint, etc. are applied in advance, and the present paint is applied to an object formed by curing these coating films. Among these, the metal coated object is
It is preferable to perform chemical conversion treatment with phosphate, chromate, or the like. As the undercoat paint and the intermediate paint, those known per se can be used.

The present coating composition is used for these objects (undercoating coating,
Furthermore, it can be applied by electrostatic coating, airless spray, air spray, etc. The coating film thickness is generally 5 to 30 μm, particularly 10 to 20 μm, based on the cured coating film.

The metallic coating film of the present coating composition is allowed to stand at room temperature for several minutes, and then the clear coating composition is applied to the uncured coating surface without crosslinking and curing. The clear coating is applied by a coating method such as electrostatic coating, airless spray or air spray so that the film thickness is about 10 to 70 μm, preferably 20 to 50 μm, and then about 100 to 1
80 ° C, preferably about 10-40 at about 120-160 ° C
The method is accomplished by heating for minutes to crosslink and cure both coatings simultaneously.

[0097]

1) The present coating composition has a thermosetting resin composition (A), a metallic pigment (B) and a glass transition temperature of 30.
Flip-flop (FF) containing non-melting type crosslinked resin particles (C) and metal silicate (D) at 130 ° C
And the dispersibility of the metallic pigment are improved, and it is possible to form a metallic coating film having excellent glitter and excellent glitter.

2) In a multilayer coating film obtained by applying a clear coating on the uncured surface of the present coating and then heating the coatings simultaneously to cure them, there is no interphase between the layers of the coatings. It is possible to form a metallic coating film having an excellent glitter and an excellent glitter property.

3) In this method, as the clear paint,
Use of high solids clear coatings (1) to (3) is preferable from the viewpoint of environmental protection and resource saving, and there is no occurrence of cracks (foaming) on the coated surface, and etching and stains of the coating film due to acid rain. It has an effect that it is particularly effective as a paint for forming an uppermost top coating film for automobiles, in which it is possible to prevent the generation of dirt and the like, and almost no generation of scratches due to a car washing machine or the like is observed.

4) When the high solid content clear coatings (1) to (3) are used as the clear coating, a coating film excellent in smoothness, sharpness and feeling of flesh can be formed, and moreover, acid resistant. Toughness, scratch resistance, and finished appearance (for example, luster, texture,
It is possible to form a cured coating film having excellent image clarity.

[0101]

EXAMPLES Examples and comparative examples relating to the present invention will be described. All parts and% are based on weight, and the film thickness of the coating film is based on the cured coating film.

Example 1 20 parts of hydroxyl group-containing acrylic resin (Note 1), 30 parts of melamine resin (Note 2), three-dimensionally crosslinked resin particles (Note 3) 5
0 part, "Laponite RD" 5 parts, "Alpaste 7679NS" (manufactured by Toyo Aluminum Co., Ltd., trade name, aluminum flake paste, particle size about 12 μm, thickness 0.1 to 0.2 μm) 10 parts in deionized water The mixture was dispersed to obtain an aqueous metallic paint having a viscosity adjusted to 30 seconds / fod cup # 4/20 ° C.

Hydroxyl group-containing acrylic resin: Styrene 15
Copolymer of 20 parts of methyl methacrylate, 25 parts of ethyl acrylate, 20 parts of n-butyl acrylate, 15 parts of hydroxyethyl acrylate and 5 parts of acrylic acid. Number average molecular weight 12,000, hydroxyl value 7
2 mgKOH / g, acid value 39 mgKOH / g. Neutralize with dimethylethanolamine.

Melamine resin: "Cymel 325" (trade name, melamine resin containing imino group, manufactured by Mitsui Cytec Co., Ltd.).

Three-dimensionally crosslinked resin particles: styrene 80
Parts, 10 parts of n-butyl acrylate, 5 parts of hydroxyethyl acrylate, 5 parts of hexanediol diacrylate
Three-dimensionally crosslinked resin fine particles obtained by polymerizing a monomer component consisting of parts by an aqueous emulsion polymerization method. Hydroxyl value 2
4 mgKOH / g, glass transition temperature 65 ° C., particle size was about 160 nm (peak particle size).

Comparative Example 1 70 parts of a hydroxyl group-containing acrylic resin (Note 1), 30 parts of melamine resin (Note 2), and 10 parts of "Alpaste 7679NS" were mixed and dispersed in deionized water to give a viscosity of 30 seconds / fos. A water-based metallic paint having a cup size of 4/20 ° C. was obtained.

Comparative Example 2 20 parts of hydroxyl group-containing acrylic resin (Note 1), 30 parts of melamine resin (Note 2), three-dimensionally crosslinked resin particles (Note 3) 5
0 part and 10 parts of "Alpaste 7679NS" were mixed and dispersed in deionized water to give a viscosity of 30 seconds / foad cup # 4 /
A 20 ° C. aqueous metallic paint was obtained.

Comparative Example 3 70 parts of a hydroxyl group-containing acrylic resin (Note 1), 30 parts of a melamine resin (Note 2), 5 parts of "Laponite RD",
10 parts of "Alpaste 7679NS" was mixed and dispersed in deionized water, and viscosity was 30 seconds / fod cup # 4/20 ° C.
A water-based metallic paint of

Comparative Example 4 20 parts of hydroxyl group-containing acrylic resin (Note 1), 30 parts of melamine resin (Note 2), three-dimensionally crosslinked resin particles (Note 4) 5
0 parts, 5 parts of "Laponite RD" and 10 parts of "Alpest 7679NS" are mixed and dispersed in deionized water,
An aqueous metallic paint having a viscosity of 30 seconds / fod cup # 4/20 ° C. was obtained.

(Note 4) Three-dimensionally cross-linked resin particles: Resin particles obtained by polymerization by an aqueous emulsion polymerization method. Polymer fine particles of a monomer component consisting of 10 parts of styrene, 80 parts of n-butyl acrylate, 5 parts of hydroxyethyl acrylate and 5 parts of hexanediol diacrylate. The hydroxyl value was 24 mgKOH / g, the glass transition temperature was −33 ° C., and the particle size was about 160 nm (peak particle size).

Example 2 An epoxy resin-based cationic electrodeposition coating was applied to a cold rolled dull steel sheet that had been subjected to a chemical conversion treatment (film thickness: 25 μm), and the temperature was maintained at 170 ° C. for 3 days.
After heating and curing for 0 minutes, an intermediate coating paint (“Luga Bake AM”, manufactured by Kansai Paint Co., Ltd., trade name, polyester resin / melamine resin-based paint, gray color) is applied to a film thickness of 30 μm, and at 140 ° C. for 30 minutes. Heated and cured. On this coated surface, the water-based metallic coating material obtained in Example 1 was formed to a film thickness of 18 μm.
High-solid content clear paint (Note 5) on the uncured coating surface, which is formed by volatilizing the water in the coating film by coating it on the surface and drying at 80 ° C for 10 minutes, viscosity of 50 seconds / Ford cup # 4/2
Adjust the temperature to 0 ° C, paint to a film thickness of 35 μm, and apply 3 at 140 ° C.
A multi-layer coating film was obtained by heating both coating films simultaneously by heating for 0 minutes. The results of these performance tests are shown in Table 1.

(Note 5) High solid content type clear coating material: 20 parts of hydroxyl group-containing compound (Note 6) (solid content, the same hereinafter), polyisocyanate compound (“Desmodur N3300”,
Sumitomo Bayer Urethane Co., Ltd., trade name, hexamethylene diisocyanate isocyanurate type) 50 parts, melamine resin (Note 2) 30 parts, curing catalyst (“NACURE
5543 ", manufactured by King Industries, USA, trade name, amine neutralized solution of dodecylbenzene sulfonic acid)
1 part and 5 parts of rheology control agent (Note 7) were mixed with an organic solvent (xylol / ethyl acetate = 1/1 weight ratio) and the viscosity during coating was 50 seconds / Ford cup # 4/20
High solid content type clear coating material adjusted to ℃ and solid content rate of 76%.

(Note 6) Hydroxyl group-containing compound: 296 parts of dimethylolbutanoic acid were charged into a reaction apparatus equipped with a stirrer, a cooler, a temperature controller, a nitrogen introducing tube and a dropping funnel, and the nitrogen in the reaction vessel was replaced. It was heated to 120 ° C. 490 parts of "CARDURA E10" was added dropwise thereto over 2 hours, the temperature was kept at 120 ° C, and the reaction was terminated when the acid value became 9 or less. The resulting hydroxyl group-containing compound has a solid content of about 98% and a Gardner viscosity (20 ° C.) Z6Z.
7, hydroxyl value 428mgKOH / g, number average molecular weight 60
It was 0 and the weight average molecular weight was 610.

(Note 7) Rheology control agent: 12
-A resin acid value of 30 obtained by dehydration condensation of hydroxystearic acid using toluene as a catalyst with methanesulfonic acid as a catalyst,
Glycidyl methacrylate was added to the terminal carboxyl group of the self-condensing polyester resin having a number average molecular weight of about 1800 using dimethylaminoethanol as a catalyst to introduce a polymerizable double bond to obtain a macromonomer (a). The solid content of this product was 70%, and it had about 1 polymerizable double bond based on the number average molecular weight per molecule.

On the other hand, 174 parts of butyl acetate was placed in the flask and heated under reflux. In this, 70% macromonomer (a) was added.
Solution 297 parts, methyl methacrylate 195.9 parts, glycidyl methacrylate 18.5 parts, xylene 163.
A mixture of 0 parts and 2,6-azobisisobutyronitrile (9.6 parts) was added dropwise at a uniform rate over 3 hours, and the mixture was aged for 2 hours. Then, a mixture of 0.05 parts of p-t-butylcatechol, 3.8 parts of methacrylic acid, and 0.5 parts of dimethylaminoethanol was added to the flask, and the mixture was heated at 140 ° C. until the resin acid value became 0.5. The reaction was carried out for 5 hours to obtain a macromonomer (b) having a solid content of 50%. The obtained macromonomer (b) is a graft polymer having a first segment made of poly-12-hydroxystearic acid and a second segment made of a copolymer of methyl methacrylate and glycidyl methacrylate. It had an average of 4 polymerizable unsaturated double bonds.

On the other hand, 153 parts of xylene was placed in a flask and heated to 125 ° C., then 50 parts of 2-ethylhexyl acrylate, 23 parts of n-butyl acrylate, 25 parts of 2-hydroxyethyl acrylate, 2 parts of acrylic acid, t
4 parts of a mixture consisting of 4.5 parts of butyl peroctoate
The solution was added dropwise over a period of time and then aged for 2 hours. The resulting acrylic resin varnish had a solid content of 65% and a number average molecular weight of 7,000. This acrylic resin varnish 1
To 00 parts, 2 parts of glycidyl methacrylate, 0.01 part of 4-t-butylpyrocatechol and 0.15 part of tetrabutylammonium bromide were added and stirred at 115 ° C. for 7 hours to introduce a copolymerized double bond into the molecule. Then, a macromonomer (C) was obtained. The number of introduced double bonds in the macromonomer (c) is about 1.0 based on the number average molecular weight per molecule, SP value is 8.70, and hydroxyl value is 121 mgKOH /
It was g.

A flask was charged with 190 parts of heptane, 20 parts of 50% macromonomer (ii) solution and 23 parts of 65% macromonomer (ii) solution, and at reflux temperature, 20 parts of 50% macromonomer (ii) solution, 65%. Macromonomer (C) solution 23 parts, methyl methacrylate 50 parts, 2-
Hydroxyethyl acrylate 50 parts, glycidyl methacrylate 1.5 parts, methacrylic acid 0.8 parts, 2,2
A mixture of 2 parts of'-azobisisobutyronitrile was added dropwise over 5 hours, followed by aging for 2 hours. Then,
Dimethylaminoethanol (0.1 part) was added, and the mixture was aged for 4 hours to obtain a non-aqueous dispersion liquid of polymer fine particles. The obtained dispersion was a white dispersion having a solid content of 40%, and the particle size of the particles was about 160 nm (peak particle size). The particle size was measured by "COULTER N4 type submicron particle analyzer" by Coal Tar. The particles were insoluble in organic solvents such as acetone, ethyl acetate and xylene.

Comparative Example 5 An epoxy resin-based cationic electrodeposition coating was applied to a cold rolled dull steel sheet that had been subjected to a chemical conversion treatment (film thickness 25 μm), and the temperature was maintained at 170 ° C. for 3 days.
After heating for 0 minutes to cure, an intermediate coating (“Luga Bake AM” Kansai Paint Co., Ltd., trade name, polyester resin / melamine resin-based coating, gray color) is applied to a film thickness of 30 μm and heated at 140 ° C. for 30 minutes. And cured. The water-based metallic paint obtained in Comparative Example 1 was applied to this coating surface to a film thickness of 18 μm, and the coating film was dried at 80 ° C. for 10 minutes to volatilize the water in the coating film. Clear paint (Note 5) viscosity 50 seconds / Ford cup # 4/20
Adjust the temperature to ℃, paint to a film thickness of 35μm, 140 ℃ 30
A multi-layer coating film was obtained by heating both coating films simultaneously by heating for a minute. The results of these performance tests are shown in Table 1.

Comparative Example 6 A cold rolled dull steel sheet subjected to chemical conversion treatment was coated with an epoxy resin-based cationic electrodeposition coating (film thickness: 25 μm), and the temperature was maintained at 170 ° C. for 3 days.
After heating for 0 minutes to cure, an intermediate coating (“Luga Bake AM” Kansai Paint Co., Ltd., trade name, polyester resin / melamine resin-based coating, gray color) is applied to a film thickness of 30 μm and heated at 140 ° C. for 30 minutes. And cured. The water-based metallic paint obtained in Comparative Example 2 was applied to this coating surface to a film thickness of 18 μm, and the coating film was dried at 80 ° C. for 10 minutes to volatilize the water content in the coating film. Clear paint (Note 5) viscosity 50 seconds / Ford cup # 4/20
Adjust the temperature to ℃, paint to a film thickness of 35μm, 140 ℃ 30
A multi-layer coating film was obtained by heating both coating films simultaneously by heating for a minute. The results of these performance tests are shown in Table 1.

Comparative Example 7 Epoxy resin-based cationic electrodeposition paint was applied to a cold rolled dull steel sheet that had been subjected to chemical conversion treatment (film thickness 25 μm), and the temperature was maintained at 170 ° C. for 3 days.
After heating for 0 minutes to cure, an intermediate coating (“Luga Bake AM” Kansai Paint Co., Ltd., trade name, polyester resin / melamine resin-based coating, gray color) is applied to a film thickness of 30 μm and heated at 140 ° C. for 30 minutes. And cured. The water-based metallic paint obtained in Comparative Example 3 was applied to this coating surface to a film thickness of 18 μm, and the coating film was dried at 80 ° C. for 10 minutes to volatilize the water in the coating film. Clear paint (Note 5) viscosity 50 seconds / Ford cup # 4/20
Adjust the temperature to ℃, paint to a film thickness of 35μm, 140 ℃ 30
A multi-layer coating film was obtained by heating both coating films simultaneously by heating for a minute. The results of these performance tests are shown in Table 1.

Comparative Example 8 A cold rolled dull steel sheet subjected to chemical conversion treatment was coated with an epoxy resin-based cationic electrodeposition coating (film thickness: 25 μm), and the temperature was maintained at 170 ° C. for 3 days.
After heating for 0 minutes to cure, an intermediate coating (“Luga Bake AM” Kansai Paint Co., Ltd., trade name, polyester resin / melamine resin-based coating, gray color) is applied to a film thickness of 30 μm and heated at 140 ° C. for 30 minutes. And cured. The water-based metallic paint obtained in Comparative Example 4 was applied to the coated surface to a film thickness of 18 μm, and the coating film was dried at 80 ° C. for 10 minutes to volatilize the water content in the coating film. Clear paint (Note 5) viscosity 50 seconds / Ford cup # 4/20
Adjust the temperature to ℃, paint to a film thickness of 35μm, 140 ℃ 30
A multi-layer coating film was obtained by heating both coating films simultaneously by heating for a minute. The results of these performance tests are shown in Table 1.

[0122]

[Table 1] Table 1

The test method for the multilayer coating film is as follows. Whiteness of highlight: The IV value was measured using ALCOP LMR100 (trade name, manufactured by Fuji Industry Co., Ltd.). The larger this value is, the better the whiteness of the highlight portion is.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) C09D 7/12 C09D 7/12 (72) Inventor Yoshizumi Matsuno 4-17-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai Paint Co., Ltd. F term (reference) 4D075 AE12 BB26Z CA02 CA33 CA48 CB04 CB06 CB13 DA06 DB01 DB31 DC11 DC18 EA06 EA08 EA10 EA19 EA43 EB14 EB16 EB20 EB22 EB32 EB01 EC21 EC02 EC23 EC01 EC23 EC23 4 HA456 KA08 MA02 MA08 MA13 NA01

Claims (4)

[Claims] 1. A thermosetting resin composition (A), a metallic pigment (B), a non-melting type crosslinked resin particle (C) having a glass transition temperature of 30 to 130 ° C., and a metal silicate (D). Aqueous metallic paint characterized by the following. 2. The non-melting type crosslinked resin particles (C) use one or more selected from isobornyl (meth) acrylate, cyclohexyl (meth) acrylate and styrene as a polymerizable monomer component. The water-based metallic paint according to claim 1, which is polymer particles. 3. The aqueous metallic coating composition according to claim 1 or 2 is applied, the uncured coating surface is coated with the clear coating material, and then both coatings are simultaneously heated to crosslink and cure. A method for forming a multilayer coating film by the coat 1 bake method. 4. The method for forming a multilayer coating film according to claim 3, wherein the clear coating material is a high solid content clear coating material.