JP3908008B2 - Glittering paint composition, method for forming a glittering coating film, and coated article - Google Patents

Description

【００６１】
表１の結果から明らかのように、本実施例は、本発明の光輝性塗膜形成方法で得た塗装物であり、光輝ムラの発現しない光輝感が得られた。一方、比較例では、本発明の範囲を外れているため、光輝ムラが明らかに認められた結果であった。
【００６２】
【発明の効果】
本発明においては、被塗基材に、Ｌ値が１０以下の黒色ベース塗膜層を形成した後、上記黒色ベース塗膜層上に、ビヒクル、塗料固形分に対して０．５〜５質量％の光輝性顔料、体質顔料、及び、高分子アミン系顔料分散剤を含有する光輝性塗料組成物を光輝性クリヤー塗膜層として形成し、次いで上記光輝性クリヤー塗膜層上にトップクリヤー塗膜層を形成することによって、光輝ムラの発現しない光輝感が得られた。その結果、より高級感のある光輝感が得られる塗膜を形成することができるようになった。なお、本発明により得られる塗膜は上記光輝感を呈するため、自動車、二輪車等の乗物外板、容器外面、コイルコーティング、家電業界等の光輝性が要求される分野において好ましく使用される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glittering paint composition, a method for forming a glittering coating film, and a coated article coated by this method.
[0002]
[Prior art]
In fields where high design properties are required, such as automobile bodies, a coating film using a glitter paint containing a glitter pigment is required. As one of such glitter paints, for example, In Kaihei 8-155384, as a method for forming a multi-layer coating film for forming a high-quality color coating film having a glittering feeling and a high depth and saturation, a lightness in the Munsell display system on the substrate is N3 or less. An undercoating film forming step of applying a colored undercoating paint, an interference mica pigment having a vehicle and a dark area on the undercoating film surface, and a hue H in the Munsell display system of the interference mica pigment with respect to the Munsell hue ring 100 A top coat forming step of applying a top coat containing at least one coloring pigment in a hue range of 0 ± 25 when the interference color hue is set to 0 and the counterclockwise +50 and clockwise -50 are displayed. , Sequentially It is described to apply to.
[0003]
However, in the technique of the above publication, the orientation control of the glitter pigment is not mentioned, and in the color gamut where the brightness difference between the black base coating layer and the glitter clear coating layer is large as described above, the glitter pigment. Since the fine change in the orientation of the film generates uneven brightness, it was not sufficient to suppress the generation of uneven brightness in the dark glitter coating film.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a glittering paint composition, a method for forming a glittering coating film, and a coated article that can suppress the occurrence of uneven brightness even in a bright glittering coating film.
[0005]
[Means for Solving the Problems]
As a result of intensive studies in view of the above problems, the present inventors have arrived at the present invention.
[0006]
1. A glittering paint composition containing 0.5 to 5% by mass of a glittering pigment, an extender pigment, and a polymer amine pigment dispersant with respect to the solid content of the vehicle and the paint.
[0007]
2. The bright paint composition as described above, wherein the extender pigment is barium sulfate, and the content of the barium sulfate is 0.5 to 20% by mass with respect to the solid content of the paint.
[0008]
3. The above-mentioned glittering paint composition, wherein the barium sulfate has an average particle size of 0.02 to 1 μm.
[0009]
4). The glittering paint composition as described above, wherein the polymer amine pigment dispersant is contained in an amount of 0.5 to 5% by mass based on the solid content of the paint.
[0010]
5. After forming a black base coating layer having an L value of 10 or less on the substrate to be coated, a glittering clear coating layer is formed on the black base coating layer using the above-mentioned glittering coating composition. Then, a glittering coating film forming method of forming a top clear coating film layer on the glittering clear coating film layer.
[0011]
6). The glitter coating film forming method as described above, wherein the top clear coating film layer is formed from a clear coating material, and the clear coating material is a coating material including a resin containing a carboxyl group-containing polymer and an epoxy group-containing polymer.
[0012]
7). A coated product obtained by the above-described glittering coating film forming method.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail.
[0014]
[Glittering paint composition]
The glittering paint composition of the present invention comprises a glittering clear coating film described later containing a glittering pigment, an extender pigment, and a polymeric amine pigment dispersant in an amount of 0.5 to 5% by mass based on the vehicle and the solid content of the paint. It is a clear paint that forms a layer.
[0015]
[Vehicle]
The vehicle contained in the glitter coating composition disperses the glitter pigment, and is composed of a coating film-forming resin and, if necessary, a crosslinking agent.
[0016]
Examples of the coating film forming resin constituting the vehicle include (a) acrylic resin, (b) polyester resin, (c) alkyd resin, (d) fluororesin, (e) epoxy resin, and (f) polyurethane resin. (G) polyether resins and the like, and acrylic resins and polyester resins are particularly preferably used. These can be used in combination of two or more. In addition, the coating film-forming resin includes a curable type and a lacquer type, and usually a curable type is used. In the case of a curable type, it is used by mixing with a crosslinking agent such as an amino resin, a (block) polyisocyanate compound, an amine, a polyamide, or a polyvalent carboxylic acid, and is subjected to a curing reaction at heating or normal temperature. Can be advanced. Moreover, it is also possible to use together the resin for film-formation which does not have curability with the type which has curability.
[0017]
As said acrylic resin (a), the copolymer of an acryl-type monomer and another ethylenically unsaturated monomer can be mentioned. Acrylic monomers that can be used for the copolymerization include methyl, ethyl, propyl, n-butyl, i-butyl, t-butyl, 2-ethylhexyl, lauryl, phenyl, benzyl, 2-hydroxy of acrylic acid or methacrylic acid. Examples thereof include esterified products such as ethyl and 2-hydroxypropyl, ring-opening adducts of caprolactone of acrylic acid or 2-hydroxyethyl methacrylate, acrylamide, methacrylamide and N-methylolacrylamide. Examples of other ethylenically unsaturated monomers copolymerizable with these include styrene, α-methylstyrene, itaconic acid, maleic acid, and vinyl acetate.
[0018]
As said polyester resin (b), saturated polyester resin and unsaturated polyester resin are mentioned, For example, the condensate obtained by heat-condensing a polybasic acid and a polyhydric alcohol is mentioned. Examples of the polybasic acid include saturated polybasic acid and unsaturated polybasic acid. Examples of the saturated polybasic acid include phthalic anhydride, terephthalic acid, succinic acid and the like, and unsaturated polybasic acid. Examples thereof include maleic acid, maleic anhydride, and fumaric acid. Examples of the polyhydric alcohol include dihydric alcohol and trihydric alcohol. Examples of the dihydric alcohol include ethylene glycol and diethylene glycol. Examples of the trihydric alcohol include glycerin and trimethylolpropane. Etc.
[0019]
As said alkyd resin (c), modifiers, such as fats and fatty acids (soybean oil, linseed oil, coconut oil, stearic acid, etc.), natural resins (rosin, succinic acid, etc.), etc. are added to the above polybasic acid and polyhydric alcohol. An alkyd resin obtained by reaction and modification can be used.
[0020]
The fluororesin (d) is composed of any one of vinylidene fluoride resin, tetrafluoroethylene resin or a mixture thereof, a polymerizable compound containing a fluoroolefin and a hydroxy group, and other copolymerizable vinyl compounds. Examples thereof include resins made of various fluorine-based copolymers obtained by copolymerizing monomers.
[0021]
As said epoxy resin (e), the resin etc. which are obtained by reaction of bisphenol and epichlorohydrin can be mentioned. Examples of bisphenol include bisphenol A and F. Examples of the bisphenol type epoxy resin include Epicoat 828, Epicoat 1001, Epicoat 1004, Epicoat 1007, Epicoat 1009 (all trade names, manufactured by Shell Chemical Co., Ltd.) and the like, and these are used with an appropriate chain extender. A chain-extended one can also be used.
[0022]
As said polyurethane resin (f), resin which has a urethane bond obtained by reaction of various polyol components, such as an acryl, polyester, polyether, a polycarbonate, and a polyisocyanate compound can be mentioned. Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), and mixtures thereof (TDI), diphenylmethane-4,4 ′. Diisocyanate (4,4′-MDI), diphenylmethane-2,4′-diisocyanate (2,4′-MDI), and mixtures thereof (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3 ′ -Dimethyl-4,4'-biphenylene diisocyanate (TODI), xylylene diisocyanate (XDI), dicyclohexylmethane diisocyanate (hydrogenated HDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), hydrogenated xylylene diene Isocyanate (HXDI) etc. It can be mentioned.
[0023]
The polyether resin (g) is a polymer or copolymer having an ether bond, and is a polyoxyethylene polyether, polyoxypropylene polyether, polyoxybutylene polyether, bisphenol A or bisphenol. Examples thereof include polyether resins having at least two hydroxyl groups per molecule, such as polyethers derived from aromatic polyhydroxy compounds such as F. Also, the polyether resin is reacted with a polyvalent carboxylic acid such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, or a reactive derivative such as these acid anhydrides. And a carboxyl group-containing polyether resin obtained.
[0024]
When the vehicle includes a cross-linking agent, the ratio of the resin for forming a coating film to the cross-linking agent is preferably 90 to 50% by mass of the resin for forming a film and 10 to 50% by mass of the cross-linking agent in terms of solid content. The film-forming resin is 85 to 60% by mass, and the crosslinking agent is 15 to 40% by mass. When the crosslinking agent is less than 10% by mass (when the coating film forming resin exceeds 90% by mass), crosslinking in the coating film is not sufficient. On the other hand, if the crosslinking agent exceeds 50% by mass (if the coating film forming resin is less than 50% by mass), the storage stability of the coating composition decreases and the curing rate increases, resulting in poor coating appearance.
[0025]
When the vehicle contains a crosslinking agent, the crosslinking agent is preferably an amino resin, particularly a melamine resin. Examples of the melamine resin include butylated melamine resin etherified by n-butyl group or i-butyl group alone, and methyl / butyl mixed etherified melamine etherified by n-butyl group or i-butyl group and methyl group. A resin is more preferable. In addition, other amino resins such as benzoguanamine resin can be used even if they are other than the above.
[0026]
[Illuminating pigment]
As the bright pigment, preferably, aluminum flake pigment, metal oxide-coated alumina flake pigment, metal oxide-coated silica flake pigment, graphite pigment, interference mica pigment, colored mica pigment, metal titanium flake pigment, stainless steel flake pigment, plate It is at least one pigment selected from the group consisting of a glassy iron oxide pigment, a metal-plated glass flake pigment, a metal oxide-coated plated glass flake pigment, a hologram pigment, and a flake pigment composed of a cholesteric liquid crystal polymer. At least one pigment selected from the group consisting of aluminum flake pigment, metal oxide-coated alumina flake pigment, metal oxide-coated silica flake pigment, graphite pigment, metal oxide-coated mica pigment, and metal oxide-coated glass flake pigment It is still more preferable that it contains.
[0027]
Further, the content of the glitter pigment (weight ratio of the solid content of the pigment relative to 100 parts by weight of the solid content of paint: PWC) is 0.5 to 5% by mass and 0.5% by mass with respect to the solid content of the paint. If it is less than 5%, it is difficult to exhibit glitter, and if it exceeds 5% by mass, the composite color effect with the black color base coating film cannot be exhibited. Preferably it is 1-3 mass%. The solid content of the paint includes a vehicle, a luster pigment, an extender pigment, a color pigment, a polymer amine pigment dispersant, and a solid component. However, when a liquid is contained in the vehicle, the liquid portion is not contained in the paint solid content.
[0028]
[External pigment]
The glitter paint composition contains extender pigments in order to exert the effect of controlling the orientation of the glitter pigment. Examples of the extender pigment include talc, calcium carbonate, barium sulfate, and silica. Barium sulfate having an average particle diameter of 0.02 to 1 μm is preferably used. If the average particle diameter is out of the range, the effect of controlling the orientation of the glitter pigment may not be exhibited. The preferred content of the extender pigment (the solid content weight ratio of the pigment to 100 parts by weight of the paint solid content: PWC) is 0.5 to 20% by mass with respect to the paint solid content, and less than 0.5% by mass. The orientation control effect may not be exhibited, and if it exceeds 20% by mass, the coating film appearance may be poor. Preferably it is 5-15 mass%.
[0029]
[Coloring pigments]
The glitter paint composition can contain a color pigment in an addition amount within a range that does not hinder the development of the glitter design. As such a colored pigment, for example, as an organic pigment, for example, an azo lake pigment, a phthalocyanine pigment, an indigo pigment, a perylene pigment, a quinophthalone pigment, a dioxazine pigment, a quinacridone pigment, an isoindolinone pigment, Examples of the inorganic pigment include yellow iron oxide, red iron oxide, titanium dioxide, and carbon black. In addition, the total content of all the above-mentioned pigments (pigment solid content weight ratio: PWC with respect to 100 parts by weight of paint solid content) is preferably less than 55%, and more preferably less than 30%. When it exceeds 55%, the appearance of the coating film is deteriorated.
[0030]
[High molecular amine pigment dispersant]
By using a polymer amine pigment dispersant in the glitter paint composition, it is possible to suppress the glitter unevenness of the glitter coating film formed from the glitter paint composition.
[0031]
The polymeric amine pigment dispersant is a linear polymer having a pigment affinity portion composed of a basic pigment affinity group at least at one end of the main chain (including both ends) by a block or graft structure. . The basic pigment affinity group is a tertiary amino group, a quaternary ammonium group or a heterocyclic group having a basic nitrogen atom, and a linear polymer such as polyacrylate, polyurethane, polyester, or these Any one of the modified products may be mentioned. Examples of such a heterocyclic group include a pyrrole group, an imidazole group, a pyridinyl group, and a pyrimidinyl group.
[0032]
Moreover, what has 2-3000 said basic pigment affinity groups in 1 molecule is preferable. If it is less than 2, bright unevenness may occur. If it exceeds 3000, the viscosity may be too high and handling may be difficult. More preferably, it is 5 to 1500.
[0033]
The polymer amine pigment dispersant preferably has a number average molecular weight of 1,000 to 1,000,000. If it is less than 1000, bright unevenness may occur, and if it exceeds 1000000, the viscosity may be too high and handling may be difficult. More preferably, it is 2000-500000.
[0034]
Commercially available products include “BYK-160” (BIC Chemie), “BYK-161” (BIC Chemie), “BYK-162” (BIC Chemie), “BYK-180” (BIC Chemie), “BYK”. -181 "(manufactured by Big Chemie)," BYK-182 "(manufactured by Big Chemie)," Solsparse 20000 "(manufactured by Zeneca), and the like can be used.
[0035]
The blending amount of the polymer amine pigment dispersant in the coating is preferably 0.5 to 5% by mass based on the solid content of the glittering coating composition. If the blending amount is less than 0.5% by mass, bright unevenness may occur, and if it exceeds 5% by mass, the storage stability of the paint may be lowered. More preferably, the solid content is 1 to 3% by mass.
[0036]
[Ingredients other than the above]
In addition to the above components, the glittering paint composition includes an antisettling agent such as a polyamide wax which is a lubricating dispersion of an aliphatic amide and a polyethylene wax which is a colloidal dispersion mainly composed of polyethylene oxide, a curing catalyst, an ultraviolet ray Absorbers, antioxidants, leveling agents, surface conditioners such as silicon and organic polymers, anti-sagging agents, thickeners, antifoaming agents, lubricants, crosslinkable polymer particles (microgels), etc. may be added as appropriate. it can. These additives can improve the performance of paints and coating films by blending them at a ratio of 15 parts by mass or less with respect to 100 parts by mass (solid content basis) of the vehicle.
[0037]
The glittering paint composition of the present invention is provided in a form in which the above-mentioned constituents are usually dissolved or dispersed in a solvent. Any solvent can be used as long as it dissolves or disperses the vehicle, and an organic solvent and / or water can be used. Examples of the organic solvent include those usually used in the paint field. 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, alcohols and the like. Water is preferably used when the use of organic solvents is restricted from an environmental point of view. In this case, an appropriate amount of a hydrophilic organic solvent may be contained.
[0038]
[Glittering film forming method]
In the method for forming a glittering coating film of the present invention, after forming a black base coating film layer having an L value of 10 or less on a substrate to be coated, the above-mentioned glittering paint composition is applied on the black base coating film layer. In this method, a glittering clear coating film layer is formed and then a top clear coating film layer is formed on the glittering clear coating film layer.
[0039]
[Coating substrate]
The substrate to be coated is not limited, and metals such as iron, aluminum, copper or alloys thereof; inorganic materials such as glass, cement, concrete; polyethylene resin, polypropylene resin, ethylene-vinyl acetate Polymer resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, epoxy resin and other plastic materials such as various FRPs; natural or synthetic materials such as wood, paper and cloth fiber materials Etc. In the method of forming the glittering coating film of the present invention, when the coated product obtained by the method of forming the glittering coating film of the present invention is an automobile body or a part, the substrate to be coated is previously subjected to degreasing treatment, chemical conversion treatment, electric It is preferable to form an undercoat coating film layer or an intermediate coating film layer by adhesion coating or the like. By the wet-on-wet (W / W) or wet-on-dry (W / D) on the substrate to be coated on which the intermediate coating layer is formed on the electrodeposition coating layer or the electrodeposition coating layer, A black base coating film layer having an L value of 10 or less can be formed. The above W / W is a method in which a base coat is applied and then dried by air drying or the like, and applied to an uncured or semi-cured base coat layer. On the other hand, the above W / D is a base coat. In this method, the coating film is baked and cured, and then applied to the base coating film layer. The intermediate coating is performed for concealing the base, imparting chipping resistance, and ensuring adhesion with the top coat. In the present invention, a black base coating film layer having the following L value of 10 or less can be used as the intermediate coating film layer. In this case, the intermediate coating layer is omitted.
[0040]
[Formation of Black Base Coating Layer with L Value of 10 or Less]
In the glitter coating film forming method of the present invention, the black base coating film layer having an L value of 10 or less is composed of a vehicle comprising a coating film-forming resin and, if necessary, a crosslinking agent, a coloring pigment, and optionally glittering. It is formed from a black base paint containing a pigment. This black base paint can take various forms such as a solvent type, an aqueous type, and a powder type obtained by dispersion. As the solvent-based paint or water-based paint, a one-component paint may be used, or a two-component paint such as a two-component urethane resin paint may be used. Such a paint may contain a curing catalyst, a surface conditioner, and other additives in addition to the above components. The black base coating film layer having an L value of 10 or less is a coating film layer that masks the base layer.
[0041]
In the method for forming a glittering coating film of the present invention, the resin for forming a coating film contained in the black base coating material used to form a black base coating layer having an L value of 10 or less is the above-described glittering coating composition. (A) acrylic resin, (b) polyester resin, (c) alkyd resin, (d) fluororesin, (e) epoxy resin, (f) polyurethane resin, (g) polyether resin, etc. These can be used individually or in combination of 2 or more types, Preferably they are an acrylic resin or a polyester resin.
[0042]
In the case of a curable type, the crosslinking of amino resin, (block) polyisocyanate compound, amine-based, polyamide-based, imidazole, imidazoline, polyvalent carboxylic acid, etc. described in the above-mentioned glitter coating composition Used by mixing with an agent, the curing reaction can be allowed to proceed at heating or at room temperature. It is also possible to use a lacquer-type resin for forming a coating film having no curability together with a type having curability.
[0043]
As the color pigment contained in the black base paint, the organic pigment or inorganic pigment described in the glitter paint composition is used, and carbon black is mainly used so that the L value of the black base coating layer is 10 or less. It can be selected and used. The black base paint may contain a bright pigment. Examples of these bright pigments include the bright pigments described in the bright paint composition.
[0044]
Further, in the black base paint, the color pigment and, if necessary, the kind and amount of the bright pigment are selected and added so that the L value of the coating film obtained therefrom is 10 or less. If the L value exceeds 10, it is difficult to suppress the occurrence of bright unevenness. Here, the L value means a lightness index in Hunter's color difference formula obtained from tristimulus values X, Y, and Z defined in JIS Z28722.
[0045]
The content of the colored pigment and the bright pigment blended as necessary (solid content weight ratio of pigment to 100 parts by weight of paint solid content: PWC) is preferably less than 50%, and more preferably less than 30%. When it exceeds 50%, the appearance of the coating film is deteriorated.
[0046]
In addition to the above components, the black base paint can contain various additives described in the above-mentioned glitter paint composition as appropriate. These additives can improve the performance of paints and coating films by blending, for example, at a ratio of 15 parts by weight or less with respect to 100 parts by weight (based on solid content) of the vehicle.
[0047]
When the black base paint is solvent-based or water-based, the component is usually provided in a form dissolved or dispersed in a solvent. Any solvent can be used as long as it dissolves or disperses the vehicle, and an organic solvent and water as required can be used. As an organic solvent, what was demonstrated by said glittering paint composition can be mentioned. Water is preferably used when the use of organic solvents is restricted from an environmental point of view. In this case, an appropriate amount of a hydrophilic organic solvent may be contained.
[0048]
The dry film thickness of the black base coating layer is preferably 5 to 20 μm. If the thickness is less than 5 μm, it is difficult to conceal the base. More preferably, it is 7-15 micrometers.
[0049]
[Formation of glitter clear coating layer]
The glittering clear coating film layer in the glittering coating film forming method of the present invention is formed by the glittering paint composition. The glittering clear coating film layer can be formed by W / W or W / D on the black base coating film layer having the L value of 10 or less. The glittering clear coating layer in this case does not mask the black base coating layer having the L value of 10 or less, and the dry film thickness of the glittering clear coating layer is preferably 3 to 20 μm. If it is less than 3 μm, it is difficult to express the design, and if it exceeds 20 μm, the appearance of the coating film may be poor. More preferably, it is 5-15 micrometers.
[0050]
[Formation of top clear coating layer]
In the glitter coating film forming method of the present invention, after forming the glitter clear coating film layer, the top clear coating film layer is formed thereon by W / W or W / D. In this case, the top clear coating layer does not cover the underlayer, is a colorless and transparent clear coating, and may be a so-called color clear coating imparting a translucent feeling. By forming the top clear coating layer on the coating layer, it is possible to improve gloss and prevent the bright pigment from protruding. The top clear coating layer is formed from a clear coating, and examples of the clear coating include those commonly used for top coating. The above-described curable coating-forming resin, a crosslinking agent, Can be used.
[0051]
These clear paints are blended with additives such as color pigments, extender pigments, modifiers, UV absorbers, leveling agents, dispersants, antifoaming agents, etc., as long as the transparency is not impaired. It is possible. Moreover, when the clear paint containing the carboxyl group-containing polymer and the epoxy group-containing polymer described in JP-B-8-19315 is applied to the glittering clear coating film layer with acid rain countermeasures and wet-on-wet, It is preferably used from the viewpoint of not disturbing the orientation of the glitter pigment. Further, the top clear coating layer can take various forms such as a solvent type, an aqueous type, and a powder type. As the solvent-based paint or water-based paint, a one-component paint may be used, or a two-component paint such as a two-component urethane resin paint may be used.
[0052]
The dry film thickness of the top clear coating film layer is preferably 20 to 400 μm, and if it is outside this range, the coating film appearance may be insufficient. More preferably, it is 30-200 micrometers.
[0053]
The method of forming each coating layer is not particularly limited, but spraying, roll coater, etc. are preferable when applying a solvent-based paint or water-based paint, and electrostatic coating is preferable when applying a powder paint. As a drying condition, baking is performed at 80 to 160 ° C. for a predetermined time to obtain a coating film.
[0054]
[Painted material]
The coated product of the present invention is obtained by the above-described method of forming a glittering coating film, and has a black base coating layer having an L value of 10 or less, and the vehicle and the glittering pigment on top of the black coating layer, with a coating content of 0.00. A multi-layer coating film comprising 5 to 5% by mass, an extender pigment, a glittering clear coating layer containing a polymeric amine pigment dispersant, and then a top clear coating layer is formed. The coated material on which these multilayer coating films are formed exhibits a high glitter feeling that suppresses the occurrence of uneven brightness even in a dark-colored glitter coating film.
[0055]
【Example】
EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited only to these Examples. In addition, a compounding quantity represents a weight part unless there is particular notice.
[0056]
[Examples 1 to 23, Comparative Examples 1 to 10]
[Preparation of coated substrate]
After degreasing a dull steel plate (length 300 mm, width 100 mm and thickness 0.8 mm), after chemical conversion treatment using a zinc phosphate treating agent ("Surfdyne SD2000", Nippon Paint Co., Ltd.), cationic electrodeposition coating ( “Power Top U-50” (manufactured by Nippon Paint Co., Ltd.) was electrodeposited so that the dry film thickness was 25 μm. Next, after baking at 160 ° C. for 30 minutes, a black base paint (“Orga S-90”, manufactured by Nippon Paint Co., Ltd.), which has been adjusted so that the L value becomes the value shown in Table 1, has a dry film thickness of 40 μm. Thus, it was air spray coated and baked at 140 ° C. for 30 minutes to form a black base coating layer.
[0057]
[Preparation of glitter clear paint]
Acrylic resin (styrene / methyl methacrylate / ethyl methacrylate / hydroxyethyl methacrylate / methacrylic acid copolymer, number average molecular weight about 20,000, hydroxyl value 45, acid value 15, solid content 50% by weight) and melamine resin (trade name, Vehicle, glitter pigment, extender pigment, color pigment, and polymer amine pigment dispersion obtained by blending “Uban 20SE”, manufactured by Mitsui Chemicals, Inc., solid content 60% by weight) with a solid content weight ratio of 80:20 The agents were blended in the types and proportions shown in Table 1. Next, the mixture was stirred and mixed with an organic solvent (toluene / xylene / ethyl acetate / butyl acetate weight ratio = 70/15/10/5) with a stirrer to obtain an appropriate coating viscosity to prepare a glittering clear coating material.
[0058]
[Formation of glitter clear coating film and top clear coating film]
The bright clear coating obtained above was spray-coated on the coated surface of the coated base material on which the black base was formed so that the dry film thickness was 15 μm to form a bright clear coating film. For the coating, an electrostatic coating machine (“Auto REA”, manufactured by ABB Industry Co., Ltd.) is used, and the atomization pressure is 2.8 kg / cm. ² I went there. The booth atmosphere during painting was maintained at a temperature of 25 ° C. and a humidity of 75%. After the coating, it was set for 3 minutes, and the top clear coating was applied to a dry film thickness of 35 μm, set at room temperature for 10 minutes, and baked at a temperature of 140 ° C. for 30 minutes to form a top clear coating film. The glitter feeling of the obtained multilayer coating film was evaluated by the following evaluation method. The results are shown in Table 1. The clear paint used to form the top clear coating is acrylic / melamine resin-based clear paint 1 (trade name: “Super Lac O-130 Clear”, manufactured by Nippon Paint Co., Ltd.), or a carboxyl group-containing polymer and an epoxy group-containing polymer. Are two types of clear paint 2 ("Mac Flow O-520 Clear", manufactured by Nippon Paint Co., Ltd.). The evaluation results are shown in Table 1.
[0059]
[Evaluation methods]
Luster sensation: It was visually evaluated whether or not the uniformity of radiance sensation was expressed (irregularity of luster).
3 ... No bright unevenness
2 ... Slight shine unevenness is observed
1 ... The above brightness unevenness is clearly recognized
[0060]
[Table 1]

[0061]
As is apparent from the results in Table 1, this example was a coated product obtained by the method for forming a glittering coating film of the present invention, and a glittering feeling that did not exhibit any uneven brightness was obtained. On the other hand, in the comparative example, since it was out of the scope of the present invention, bright unevenness was clearly recognized.
[0062]
【The invention's effect】
In the present invention, after a black base coating layer having an L value of 10 or less is formed on the substrate to be coated, 0.5 to 5 mass with respect to the vehicle and paint solid content on the black base coating layer. % Glitter pigment, extender pigment, and polymeric amine pigment dispersant are formed as a glitter clear coating layer, and then a top clear coating is formed on the glitter clear coating layer. By forming the film layer, a glittering feeling without the occurrence of uneven brightness was obtained. As a result, it has become possible to form a coating film that can provide a more luxurious shine. In addition, since the coating film obtained by this invention exhibits the said brightness | luminance feeling, it is preferably used in the field | areas where brightness | luminance is requested | required, such as vehicle outer plates, such as a motor vehicle and a two-wheeled vehicle, a container outer surface, a coil coating, and household appliance industry.

Claims (7)

A glittering paint composition comprising a vehicle, a glitter pigment, an extender pigment, and a polymeric amine pigment dispersant in an amount of 0.5 to 5% by mass based on the solid content of the paint. The glitter paint composition according to claim 1, wherein the extender pigment is barium sulfate, and the content of the barium sulfate is 0.5 to 20% by mass with respect to the solid content of the paint. The glitter coating composition according to claim 2, wherein the barium sulfate has an average particle size of 0.02 to 1 µm. The glitter paint composition according to any one of claims 1 to 3, wherein the polymer amine pigment dispersant is contained in an amount of 0.5 to 5 mass% based on the solid content of the paint. After forming a black base coating film layer having an L value of 10 or less on a substrate to be coated, the glittering paint composition according to any one of claims 1 to 4 is used on the black base coating film layer. A method for forming a glittering coating film, comprising forming a glittering clear coating film layer and then forming a top clear coating film layer on the glittering clear coating film layer. 6. The method for forming a glittering coating film according to claim 5, wherein the top clear coating layer is formed from a clear coating, and the clear coating is a coating containing a resin containing a carboxyl group-containing polymer and an epoxy group-containing polymer. A coated product obtained by the method for forming a glittering coating film according to claim 5 or 6.