JP2002192067A - Brilliant coating film forming method and coated material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brilliant coating film forming method which is capable of forming a brilliant coating film having a dichromatic brilliant feeling with which designs are expressed different color development varying when the coating film surface of a base material to be coated is viewed nearly from the front (highlight portion) or the coating film surface is viewed from diagonally (shaded portion) regardless of the brightness of a color base coating film layer and a coated material using the same. SOLUTION: The method comprises forming the color base coating film layer on the base material, then forming the brilliant coating film layer containing metal oxide coated silica flake pigments thereon and further forming a top clear coating film layer on the brilliant coating film layer, in which the hue of the color base coating film layer is in a hue range of +20 to +50 or -20 to -50 when the interference color in the highlight portion of the metal oxide coated silica flake pigments is defined as hue 0 in a Munsell system and the hue is indicated by counterclockwise +50 and clockwise -50 with respect to a Munsell hue ring 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a brilliant coating film and a coated article coated by the method.

[0002]

2. Description of the Related Art In a field requiring a high design such as an automobile body, a coating film using a brilliant paint containing a brilliant material is required. As one, a mica pigment coated with a metal oxide is known. By changing the coating thickness of the metal oxide, a desired interference color is obtained from the mica pigment coated with the metal oxide, and a coating film having a pearly luster can be obtained by using this in a coating. However, the glittering coating film containing the mica pigment coated with the metal oxide cannot be said to sufficiently exhibit dichroism when the viewing angle is changed.

On the other hand, silica flake pigments coated with metal oxides are used as glitter pigments exhibiting dichroism. For example, Japanese Patent Application Laid-Open No. 2000-42487 discloses that a color-based color base coating, a light interference coating forming coating containing silica flakes coated with titanium oxide or iron oxide, and a clear coating forming clear coating are sequentially applied. Is described. In this method, there is a restriction that the coating layer below the glittering coating layer is limited to a dark-colored coating layer, and the color design is not always sufficient.

[0004]

The problem to be solved by the present invention is that when the coating surface of the substrate to be coated is viewed from almost directly in front (highlight portion) regardless of the brightness of the color base coating layer. To provide a glittering coating film forming method for forming a glittering coating film capable of obtaining a dichroic glittering feeling that strongly exhibits a design exhibiting a different color development when viewed obliquely (shade portion), and a coated article. That is.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, have reached the present invention. 1. After forming a color base coating layer on a substrate, forming a glitter coating layer containing a metal oxide-coated silica flake pigment, and further forming a top clear coating layer on the glitter coating layer In the above, when the interference color in a highlight portion of the metal oxide-coated silica flake pigment is defined as a hue 0 in a Munsell display system, and displayed on the Munsell hue circle 100 at +50 counterclockwise and -50 clockwise, the color base coating A method for forming a glittering coating film, wherein the hue of the film layer is in a hue range of +20 to +50 or -20 to -50. 2. In the Munsell display system, the hue of the color base coating layer is +30 to +50, or -30 to -50.
The above method for forming a glittering coating film having a hue range of: 3. The above glittering coating film forming method, wherein the top clear coating film layer is a clear coating material containing a carboxyl group-containing polymer and an epoxy group-containing polymer. 4. A coated article obtained by the above-described method for forming a glittering coating film.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

A method for forming a glitter coating film of the present invention comprises forming a glitter coating film layer containing a metal oxide-coated silica flake pigment after forming a color base coating layer on a substrate, Further, a top clear coating layer is formed on the bright coating layer.

If necessary, a base material on which an electrodeposition coating film or an intermediate coating film is formed may be wet-on-wet (W / W),
Alternatively, a color base coating layer is formed by wet-on-dry (W / D). The above-mentioned W / W is a method in which a base coat is applied, then dried by air drying or the like, and applied to an uncured or semi-cured base coat. This is a method in which a film is baked and applied to a cured undercoat film. After the formation of the color base coating layer in this manner, the glittering coating layer is formed on the color base coating layer by W / W or W / D.

[0009] On the glittering coating layer thus formed, at least one top clear coating layer is formed as a top clear coating layer.

The method for forming each coating layer is not particularly limited, but a spray method or a roll coater method is preferred for applying a solvent-type paint or an aqueous paint, and an electrostatic coating is preferred for applying a powder paint. . Drying conditions are 80-160 ° C
For a predetermined time to obtain a glittering coating film.

Substrates The above-mentioned substrates are not limited and include metals such as iron, aluminum, copper and alloys thereof; inorganic materials such as glass, cement and concrete; polyethylene resins, polypropylene resins, ethylene- Resins such as vinyl acetate copolymer resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, epoxy resin and various plastic materials such as FRP; natural materials such as wood, paper and cloth fiber materials Or a synthetic material. In the glittering coating film forming method of the present invention, a color base coating layer is formed on the base material directly or via an undercoating film. It is preferable to perform undercoating by chemical conversion treatment, electrodeposition coating or the like, or intermediate coating. The intermediate coating is performed for hiding the base, imparting chipping resistance, and ensuring adhesion with the top coat.

Color Base Coating Layer The color base coating layer in the method for forming a glittering coating film of the present invention contains a vehicle comprising a coating film forming resin and, if necessary, a crosslinking agent, and a coloring pigment and / or a glittering pigment. Formed from color base paint. This color base coating layer has a function of expressing a composite color with the glittering coating layer and hiding the underlayer.

In the above-mentioned color base paint, the hue of the color base coating layer obtained therefrom is such that the interference color in the highlight portion of the metal oxide-coated silica flake pigment, which will be described later, is 0 in the Munsell display system. On the other hand, the type and amount of the coloring pigment and / or the glittering pigment are selected so that the hue range of +20 to +50, or -20 to -50 when displayed in the counterclockwise direction +50 and the clockwise direction -50. Added. Outside the above range, the enhanced dichroism cannot be exhibited. As a preferable range of the above range, +30 to +5
0, or -30 to -50.

The above-mentioned coloring pigments and glittering pigments include:
There can be mentioned those conventionally used for paints. For example, coloring pigments include organic pigments and inorganic pigments.Examples of organic pigments include azo lake pigments, phthalocyanine pigments, indigo pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments, and isoindolinones. Pigments, metal complex pigments and the like, and as the inorganic pigment, yellow iron oxide,
Bengala, titanium dioxide, carbon black and the like. On the other hand, as the glitter pigment, aluminum flake pigment, colored aluminum flake pigment, graphite pigment, mica pigment, metal titanium flake pigment, stainless flake pigment, plate-like iron oxide pigment, phthalocyanine flake pigment or metal-plated glass flake pigment, etc. Can be

The content of the coloring pigment and / or the brilliant pigment (weight ratio of the solid content of the pigment to 100 parts by weight of the coating material: PWC) is preferably less than 70%, more preferably 50%.
Less than is more preferable. If it exceeds 70%, the appearance of the coating film deteriorates. Various extender pigments such as talc, calcium carbonate, precipitated barium sulfate, and silica can be used in combination.

In the method for forming a glittering coating film, the coating resin for forming the color base paint used for forming the color base coating layer includes (a) an acrylic resin, (b) a polyester resin, and (c) Alkyd resin,
(D) a fluorine resin, (e) an epoxy resin, (f) a polyurethane resin, (g) a polyether resin, and the like, and these can be used alone or in combination of two or more kinds, and preferably an acrylic resin Or it is a polyester resin.

As the acrylic resin (a), a copolymer of an acrylic monomer and another ethylenically unsaturated monomer can be exemplified. Acrylic monomers that can be used in the above copolymerization include acrylic acid or methacrylic acid methyl, ethyl, propyl, n-butyl, i-butyl, t-butyl, 2-ethylhexyl, lauryl, phenyl, benzyl, 2-hydroxy Esterified compounds such as ethyl and 2-hydroxypropyl, ring-opened adducts of caprolactone of acrylic acid or 2-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide and N-
Methylol acrylamide, polyhydric alcohol (meth)
There are acrylic esters and the like. Other ethylenically unsaturated monomers copolymerizable therewith include styrene, α-methylstyrene, itaconic acid, maleic acid, vinyl acetate and the like.

Examples of the polyester resin (b) include saturated polyester resins and unsaturated polyester resins. Examples thereof include condensates obtained by heat-condensing a polybasic acid and a polyhydric alcohol. Examples of the polybasic acid include saturated polybasic acids such as phthalic anhydride, terephthalic acid, and succinic acid, and unsaturated polybasic acids such as maleic acid, maleic anhydride, and fumaric acid. Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol and diethylene glycol, and trihydric alcohols such as glycerin and trimethylolpropane. The resin for forming a coating film includes a curable type and a lacquer type, but a type having a curable type is usually used.

In the case of a type having curability, amino resins, (block) polyisocyanate compounds, amines, polyamides, imidazoles, imidazolines,
It is used by mixing with a crosslinking agent such as a polyvalent carboxylic acid, and the curing reaction can proceed at heating or at room temperature. Also,
Lacquer type coating film forming resin without curability,
It is also possible to use together with a type having curability.

When the vehicle contains a cross-linking agent, the ratio of the resin for forming a film to the cross-linking agent is 90 to 50% by mass and the content of the cross-linking agent is 10 to 50% by mass in terms of solid content. Preferably, the coating film forming resin is 85 to 60% by mass, and the crosslinking agent is 15 to 40% by mass. If the amount of the crosslinking agent is less than 10% by mass (the amount of the resin for forming a coating film exceeds 90% by mass), the crosslinking in the coating film is insufficient. On the other hand, if the crosslinking agent exceeds 50% by mass (the
), The storage stability of the coating material is reduced and the curing speed is increased, so that the appearance of the coating film is deteriorated.

In addition to the above-mentioned components, the color base coating material comprises a polyamide wax which is a lubricating dispersion of an aliphatic amide, a polyethylene wax which is a colloidal dispersion mainly composed of polyethylene oxide, an anti-settling agent, a curing catalyst, an ultraviolet absorbing agent. Agents, antioxidants, leveling agents, surface conditioners such as silicone and organic polymers, anti-sagging agents, thickeners, defoamers, lubricants, cross-linkable polymer particles (microgels), etc., appropriately added and contained. be able to. The performance of paints and coatings can be improved by blending these additives in a proportion of, for example, 15 parts by weight or less with respect to 100 parts by weight of the vehicle (based on solid content).

When the above-mentioned color base paint is of a solvent type or an aqueous type, it is usually provided in a form in which the above components are dissolved or dispersed in a solvent. Any solvent may be used as long as it dissolves or disperses the vehicle, and an organic solvent and / or water may be used. Examples of the organic solvent include those commonly used in the field of coatings.
Examples thereof include hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, cellosolve acetate and butyl cellosolve, and alcohols. When the use of an organic solvent is regulated from the viewpoint of the environment, it is preferable to use water. In this case, it may contain a suitable amount of hydrophilic organic solvent. The dry thickness of the color base coating layer is
10 to 100 μm is preferred. If it is less than 10 μm, it is difficult to hide the underlayer, and if it is more than 100 μm, the appearance of the coating film may be poor. More preferably, it is 20 to 50 μm.

Glittering coating layer The glittering coating layer in the glittering coating film forming method of the present invention comprises:
As described above, it is formed using a glitter paint containing a metal oxide-coated silica flake pigment in which the hue of the color base coating layer and the interference color in the highlight portion are in a specific range.

In the present specification, the interference color in the highlight portion means the color development when the coating surface of the substrate to be coated is viewed from almost directly in front.

The metal oxide-coated silica flake pigment is obtained by coating a substrate made of flake silica (silicon dioxide) with a metal oxide different from silica. Examples of the metal oxide coated here include iron oxide (iron monoxide, diiron trioxide, hematite) and titanium dioxide (anatase type or rutile type). The thickness of the metal oxide coating layer is preferably from 50 to 200 nm, more preferably from 60 to 180 nm. The content of the metal oxide-coated silica naflake pigment in the glitter paint (the ratio by weight of the solid content of the pigment to the paint solid content of 100 parts by weight: PWC) is preferably 3 to 20%, more preferably 5 to 15%. 5-10% is more preferable. If it is less than 3%, the appearance of brilliantness accompanied by saturation is reduced, and dichroism may not be obtained. If it exceeds 20%, the appearance of the coating film may be deteriorated.

The above-mentioned brilliant paint can take various forms such as a solvent type, an aqueous type or a powder type. The solvent-type paint or the water-based paint may be a one-pack type or a two-pack type such as a two-pack type urethane resin paint. The glitter paint can contain other glitter pigments and / or coloring pigments in a kind and in an amount that does not impair the effect of the metal oxide-coated silica naflake pigment. The glitter paint contains a vehicle, other glitter pigments, coloring pigments, and other components in addition to the pigment, and these may be the same as those described in the color base paint. .

The dry film thickness of the glittering coating layer is 10 to 5
0 μm is preferred. If it is less than 10 μm, a brilliant feeling accompanied by saturation cannot be sufficiently exhibited, and if it exceeds 50 μm, the appearance of the coating film may be insufficient. More preferably 10-3
0 μm.

Top Clear Coating Layer The top clear coating layer in the glittering coating film forming method of the present invention is a clear and colorless clear coating film which does not conceal the underlying layer, and further has a so-called semi-transparent feeling. It may be a cloudy clear coating film. By forming the top clear coating layer on the glitter coating layer, it is possible to improve the gloss and prevent the metal oxide-coated silica naflake pigment from projecting. The top clear coating layer is formed from a clear coating, and as the clear coating, those commonly used for overcoating can be used. Among the coating resins described in the above color base coating, A mixture of a compound having curability and a crosslinking agent can be used as a vehicle.

Further, these clear paints may be used, if necessary, within a range not impairing the transparency, such as coloring pigments, extenders, modifiers, ultraviolet absorbers, leveling agents, dispersants, defoamers, and the like. It is possible to incorporate additives. Further, a clear coating containing a carboxyl group-containing polymer and an epoxy group-containing polymer described in Japanese Patent Publication No. Hei 8-19315 is a bright clear coating film containing a metal oxide-coated silica naflake pigment for preventing acid rain and wet-on-wet. It is preferably used from the viewpoint of not disturbing the orientation of the metal oxide-coated silica naflake pigment when the layer is coated. In addition, the top clear coating layer can take various forms such as a solvent type, an aqueous type, or a powder type. The solvent-based paint or the water-based paint may be a one-pack type or a two-pack type such as a two-pack type urethane resin paint.

The dry film thickness of the top clear coating layer is as follows:
The thickness is preferably from 20 to 50 μm, and if it is out of this range, the appearance of the coating film may be insufficient. More preferably 25 to 4
5 μm.

Coated Product The coated product of the present invention comprises (1) a color base coating layer comprising an interference color in a highlight portion of the metal oxide-coated silica naflake pigment and a specific range of hues, and (2) a metal oxide coating. A multilayer coating film composed of a glittering coating layer containing a silica naflake pigment and (3) a top clear coating layer is formed.

The multi-layer coating film formed on the coating is smooth and has a good appearance. On the design side, the coating film is formed by the composite color of the glittering coating layer and the color base coating layer. It exhibits a brilliant feeling in which the dichroism in which the hue of the coating film looks different depending on the viewing angle can be stronger than that of the conventional one.

[0033]

EXAMPLES Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the compounding amount represents a weight part unless there is particular notice.

Examples 1 to 9 and Comparative Examples 1 to 3 Preparation of Substrates Dull steel sheets (length 300 mm, width 100 mm and thickness 0.8 mm) were degreased and then treated with zinc phosphate ("Surfdyne SD2000", Japan After a chemical conversion treatment using a paint (manufactured by Paint Co., Ltd.), a cationic electrodeposition paint (“Power Top U-5”) was used.
0 ", manufactured by Nippon Paint Co., Ltd.) was electrodeposited so that the dry film thickness was 25 μm. Then, it was baked at 160 ° C. for 30 minutes.

Formation of Color Base Coating Layer The obtained base material is air-sprayed with the following toned color base coating so as to have a dry film thickness of 40 μm, and baked at 140 ° C. for 30 minutes to obtain a color base coating film. A layer was formed. 1: Olga S-90 yellow (L value: 40), manufactured by Nippon Paint Co., Ltd. 2: Olga S-90 green (L value: 30), manufactured by Nippon Paint Co., Ltd. 3: Olga S-90 Blue (L value: 20), manufactured by Nippon Paint Co., Ltd. 4. "Orga S-90" red (L value: 35), manufactured by Nippon Paint Co., Ltd. L value: tristimulus values X, Y specified in JIS Z 8722,
It is a lightness index in the Hunter's color difference equation obtained from Z.

Preparation of glitter paint Acrylic resin (styrene / methyl methacrylate / ethyl methacrylate / hydroxyethyl methacrylate /
Methacrylic acid copolymer, number average molecular weight about 20,000,
A hydroxyl value of 45, an acid value of 15, and a solid content of 50% by weight, and a melamine resin (trade name, “Uban 20SE”, manufactured by Mitsui Chemicals, Inc., solid content of 60% by weight) are blended at a solids weight ratio of 80:20. The obtained vehicle was mixed with a metal oxide-coated silica flake pigment and, if necessary, a coloring pigment in the types and ratios shown in Table 1. Then, the organic solvent (toluene / xylene / ethyl acetate / butyl acetate weight ratio = 70)
/ 15/10/5) with a stirrer so as to obtain a coating proper viscosity to prepare a glittering paint. In Comparative Example 3, an interference mica pigment was used instead of the metal oxide-coated silica flake pigment.

[0037]Bright coating layer and top clear coating layer
Formation On the coated surface of the substrate on which the color base coating layer is formed,
Bring the previously obtained glitter paint to a dry film thickness of 15 μm.
Spray painted. Coating is performed using an electrostatic coating machine (“Auto R
EA ", manufactured by ABB Industry Co., Ltd.)
2.8kg / cm ^TwoI went in. Booth atmosphere during painting
Was maintained at a temperature of 25 ° C. and a humidity of 75%. 3 minutes after painting
The clear paint to a dry film thickness of 35 μm.
And set at room temperature for 10 minutes.
Bake at a temperature of 0 ° C. for 30 minutes. Two colors of the obtained coating film
The property was evaluated by the following evaluation method. Table 1 shows the results. use
Clear paint is acrylic / melamine resin clear paint
-Paint 1 (trade name: "Super Rack O-130 Clearer"
-", Manufactured by Nippon Paint Co., Ltd.) or containing a carboxyl group
Clear containing polymer and epoxy group-containing polymer
-Paint 2 ("Macflow O-520 Clear", Japan
Paint Co., Ltd.).

Evaluation method Two-color: When the test plate was viewed from almost directly in front (highlight portion) and when the test plate was viewed obliquely (shade portion),
The hues were different, and the appearance of the two-color design was visually evaluated. 3: Two-color design is noticeably exhibited. 2--Two-color design is exhibited. 1: Two-color design is not exhibited.

[0039]

[Table 1]

As is evident from the results in Table 1, this example is a coated article obtained by the glittering coating film forming method of the present invention.
A brilliant feeling in which dichroism was emphasized was developed. On the other hand, the comparative example is a coated product obtained by a method other than the glittering coating film forming method of the present invention, and did not sufficiently exhibit dichroism.

[0041]

According to the present invention, the interference color in the highlight portion of the metal oxide-coated silica flake pigment is set to hue 0 in the Munsell display system on the substrate, and +50 counterclockwise and right The hue of the color base coating layer is + 20-
Forming a color base coating layer having a hue range of +50 or -20 to -50, and then forming a metal oxide-coated silica naflake pigment-containing brilliant coating layer, and further on the brilliant coating layer By forming the top clear coating layer using the clear paint, it becomes possible to express a glittering effect in which dichroism is emphasized regardless of the brightness of the color base coating layer, and as a result, a more luxurious feeling It has become possible to form a coating film with a certain depth of glitter.

Since the coating film obtained by the present invention exhibits the above-mentioned glitter, it is preferably used in fields requiring glitter, such as automobile outer panels, motorcycle outer panels, outer surfaces of containers, coil coating, and the home appliance industry. You.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 201/00 201/00 201/06 201/06 201/08 201/08 F Terms (Reference) 4D075 CB04 DC12 EA43 EC03 EC11 EC23 4J037 AA02 AA06 AA18 AA22 AA25 CA09 CC14 CC17 CC23 CC24 CC25 CC26 DD10 EE03 FF09 4J038 CC031 CG141 CG171 CH121 CH171 DA132 DD051 DD121 DD191 DH002 HA066 KA002 HA3626 MA07 MA10 NA01 NA19 PA07 PA19 PB07 PC02 PC03 PC04 PC06 PC08 PC10

Claims (4)

[Claims] 1. After forming a color base coating layer on a substrate, a glitter coating layer containing a metal oxide-coated silica flake pigment is formed, and a top clear coating layer is further formed on the glitter coating layer. In the method of forming a layer, the interference color in the highlight portion of the metal oxide-coated silica flake pigment is defined as a hue 0 in a Munsell display system, and is displayed with a counterclockwise rotation of +50 and a clockwise rotation of −50 with respect to the Munsell hue circle 100. The hue of the color base coating layer is +20 to +
A method for forming a glittering coating film having a hue range of 50 or -20 to -50. 2. In the Munsell display system, the hue of the color base coating layer is +30 to +50 or -30.
The method for forming a brilliant coating film according to claim 1, wherein the hue range is from -50 to -50. 3. The method according to claim 1, wherein the top clear coating layer is formed from a clear coating containing a carboxyl group-containing polymer and an epoxy group-containing polymer. 4. A coated article obtained by the method for forming a glittering coating film according to any one of claims 1 to 3.