WO2008059924A1

WO2008059924A1 - Method of forming laminated coating

Info

Publication number: WO2008059924A1
Application number: PCT/JP2007/072188
Authority: WO
Inventors: Yoshiko Aoki; Shinichi Mashiko; Norikuni Tabii
Original assignee: Nippon Paint Co., Ltd.
Priority date: 2006-11-16
Filing date: 2007-11-15
Publication date: 2008-05-22
Also published as: JP2008126095A; JP4942459B2

Abstract

A method of forming a laminated coating being less in the fluctuation of coating appearance (color formation) and having stable designability. The method of forming a laminated coating is one comprising sequentially superimposing on a coating application object with intermediate coating a metallic base coating, a mica base coating and a color clear coating, wherein the hue exhibited by the metallic base coating, the hue exhibited by the mica base coating and the hue exhibited by the color clear coating are like colors or at least mutually adjacent hues in the color arrangement of hue circle of Munsell color system; and wherein the mica base coating is a coating formed so that the 15˚ L* value of coating composed of the metallic base coating and the mica base coating has a fluctuation range of -18 to -30% based on the 15˚ L* value of the metallic base coating; and wherein the 15˚ L* value of the laminated coating consisting of the metallic base coating, mica base coating and color clear coating is in the range of 20 to 60.

Description

Specification

Method for forming laminated coating film

Technical field

[0001] The present invention relates to a method for forming a laminated coating film that can be formed on an automobile body or an automobile part.

Background art

[0002] On the surface of a substrate such as an automobile, a plurality of coating films having various roles are formed to protect the substrate and at the same time give a beautiful appearance. The appearance of the coating film formed on the automobile is greatly related to the appearance value such as the luxury feeling of the automobile. Therefore, in the field of automobile coating, there is a need for establishment of a coating composition and a coating method that can form a coating film having a coating appearance that meets various needs.

[0003] For such overcoating of automobile bodies and the like, painting using bright pigments such as aluminum flakes and My strength is known. However, when forming a multilayer coating film using these bright pigments, there is a problem that it is difficult to obtain a certain coating film appearance with good reproducibility. The reason for this is that when these bright pigments are used, the appearance of the paint film, such as the color tone, differs due to slight changes in the paint film thickness, etc. derived from the shape of the object to be coated. This is because it is difficult to obtain stable color development. In other words, when coating a large and uneven article, there is a problem that the coating film thickness varies depending on the portion of the coating, and the hue varies depending on the film thickness variation.

[0004] Japanese Patent Application Laid-Open No. 2001-314807 (Patent Document 1) discloses that a first coating containing (1) a coloring component and / or a glittering material is applied to the surface of an object to be coated. A step of forming a film; (2) a step of forming a second coating film by applying a second paint containing a coloring component on the first coating film without baking and curing the first coating film; (3) Furthermore, a multilayer coating film forming method including a step of forming a clear coating film by applying a clear paint on the second coating film without baking and curing the second coating film is described. The multilayer coating film formed by this method contains a glittering material in the first coating film and a coloring pigment in the second coating film, but does not include my strength-based coating film formation. However, the process is different from that of the present invention. JP-A-2002-273332 (Patent Document 2) describes (1) a step of forming a glittering base coating film with a hidden film thickness of 10 m or less on a base material, and (2) a color tailor base. A glittering coating film forming method is described in which a coating film forming step and (3) a tallyer top coating film forming step are sequentially performed. The glitter coating film formed by this method is also different from the present invention in that it is composed of a glitter base coating film, a color tarrier base coating film, and a tarrier top coating film.

[0006] In JP 2003-236465 A (Patent Document 3), a color base coating film is formed, and after baking and curing, a base color coating film, a My strength base coating film, and a talya coating film are sequentially formed. In the forming method of the My strength coating film, the hue exhibited by the color base coating film, the hue exhibited by the base color coating film, and the hue exhibited by the My strength base coating film are similar colors, and the My strength base coating film. The high-strength My-strength coating film forming method characterized in that the My-strength base coating material for forming a paint contains a transparent pigment and a non-transparent pigment in a mass ratio of 3 / ;! to 20/1 Is described. The coating film formed by this method does not include the formation of a My strength base coating film using My strength base paint containing a transparent pigment and a non-transparent pigment, and does not include the formation of a color coating film during the painting process. In this respect, it is different from the present invention.

[0007] Japanese Patent Application Laid-Open No. 11 276983 (Patent Document 4) discloses that a colored base coating film layer containing a coloring pigment is formed on an intermediate coating film of an object to be coated, and a reflection color and an absorption color are formed thereon. In the method of forming a laminated coating film, in which a My strength base coating layer containing colored My strength pigments having different hues is formed, and further a clear coating layer is formed thereon, the hue of the coloring base coating layer is changed. There is described a method for forming a multilayer coating film, characterized in that the absorption color of the colored strength pigment of the My strength base coating layer is the same color. This method is different from the present invention in that it is characterized by the use of colored my strength pigments, and does not include the formation of a color tar coat film during the coating process.

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2001-314807

Patent Document 2: JP 2002-273332 A

Patent Document 3: Japanese Patent Laid-Open No. 2003-236465

Patent Document 4: JP-A-11 276983 Disclosure of the invention

Problems to be solved by the invention

[0009] The present invention solves the above-described conventional problems, and the object of the present invention is to apply a coating film on a top coat that can be formed on an automobile body or an automobile part. An object of the present invention is to provide a method for forming a laminated coating film having a stable design with little variation in film appearance (color development).

Means for solving the problem

[0010] The present invention provides:

A method for forming a multilayer coating film in which a metallic base coating film, a My strength base coating film, and a color clear coating film are sequentially formed on an object having an intermediate coating film, the hue exhibited by the metallic base coating film, In the hue exhibited by the My Power base coating film and the hue force s exhibited by this color-tally coating film, the color arrangement of the hue ring of the Munsell color system is the same color or at least adjacent hues,

This strength-based coating film has a variation range of 15 ° L * value of a metallic base coating and a coating composed of a strength base coating with respect to the 15 ° L * value of the metallic base coating. % Is a coating film formed so as to be,

The 15 ° L * value of this metallic base coating, the laminate of this strength base coating and this color tarrier coating is 20-60, and

The metallic base coating composition forming this metallic base coating film contains a non-transparent scaly pigment having an average particle size of 6 to 40, im in an amount of 5 to 25% by mass of pigment mass concentration (PWC). And

The My strength base coating composition for forming this My strength base coating film contains a transparent scaly glitter pigment in an amount of pigment mass concentration (PWC) O. 25 to 15% by mass,

The color tartar coating composition for forming the color tartar coating film contains a coloring pigment in an amount of a pigment mass concentration (PWC) O. 01 to 10 mass%.

A method for forming a laminated coating film is provided, whereby the above object is achieved.

[0011] In the above method for forming a multilayer coating film, the color tally coating is further a 15 ° L * of a multilayer coating consisting of a metallic base coating, a My strength base coating, and a color tally coating. A coating film formed so that the fluctuation range is 16 30% with respect to the 15 ° L * value of the coating film composed of the metallic base coating film and the My strength base coating film, and

The 15 ° L * value of the obtained multilayer coating film preferably has a variation width of 047% with respect to the 15 ° L * value of the metallic base coating film.

[0012] The present invention further comprises four layers, in which a top tally coating film is further formed on the laminated coating film formed by the method for forming these laminated coating films using a top tarry coating composition. A method for forming a laminated coating is also provided.

[0013] The present invention further provides a multilayer coating film formed by these multilayer coating film forming methods.

The invention's effect

[0014] The laminated coating film according to the present invention has an advantage of exhibiting a stable design property by having a My strength base coating film and a color tailor coating film on a metallic base coating film. In the laminated coating of the present invention, the hues of the metallic base coating, the My strength base coating, and the force rotatory coating are similar colors or at least adjacent to each other in the color arrangement of the Munsell color system. And 15 ° L * values based on these coatings are in a specific range. As a result, it is possible to provide a coating film with a sense of depth and excellent design properties in a state where there is little variation in coating film appearance (color development). That is, the present invention is an invention in which a means for providing a coating film having a sense of depth and excellent design properties in a state and with a small variation in coating film appearance (coloring property) has been found.

Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of a laminated coating film prepared in an example.

FIG. 2 is a diagram schematically illustrating a light source irradiation angle.

Explanation of symbols

[0016] 1: Coating object, 3: Electrodeposition coating, 5: Intermediate coating, 7: Metallic base coating, 9: My strength base coating, 11: Color tally coating, 13: Top tally coating film.

BEST MODE FOR CARRYING OUT THE INVENTION

First, the process up to the present invention will be described. For painting substrates such as automobiles! For example, in the case of forming a colored laminated coating film (including a base coating film and a color tally coating film) such as red, the hue of the base coating film on the base is the same color as the colored color coating film provided thereon. May have a red metallic color. The purpose of setting the hue of the base coating film in this way is to reduce the hue fluctuation of the laminated coating film when the thickness of the color-tally coating film formed on the base coating film changes.

[0018] However, for the purpose of reducing the hue variation of the laminated coating film, if the hue of the base coating film and the hue of the laminated coating film are too close, the depth feeling in the laminated coating film is lost. There is a profit. The feeling of depth in the laminated coating film is greatly related to the design of the coating film appearance. A coating film having a sense of depth has a sense of quality and is excellent in design.

The object of the present invention is to establish a method capable of preparing a laminated coating film having a sense of depth and excellent design properties in a state where the coating film appearance (coloring property) has little variation! / The inventors of the present invention have the lightness of V and so-called highlight when forming a multilayer coating film composed of a metallic base coating film, a mybasic coating film, and a color tailor coating film having hues of similar colors. ° We found that fluctuations in L * values were greatly related to the appearance of the resulting multilayer coating. Thus, it was also found that the object of the present invention can be achieved by adjusting the 15 ° L * value of the coating film to a specific range. Hereinafter, the method of the present invention will be described sequentially.

[0020] Metallic base coating composition

In the method for forming a laminated coating film of the present invention, a metallic base coating composition is used to form a metallic base coating film. As the metallic base coating composition, those containing a non-transparent scaly pigment, a color pigment, a film-forming resin, a curing agent, and the like are preferably used.

By including a non-transparent scaly glitter pigment in the metallic base coating composition, a metallic base coating film having high brightness of noh and illite can be formed. In non-transparent scale pigments, “non-transparency” means the pigment concentration (PWC) in the paint solids is 2

This means that the black-and-white concealment film thickness of the coating film obtained when 5% by mass is less than 30 m. This black and white masking film thickness is used to measure the masking power of the coating composition. It can be measured using a high-rate measuring paper (standard: JIS K5600). The measurement method of black and white masking film thickness is as follows. Spray paint is applied on the 2 x 2cm square black and white pine pattern of the cover ratio measurement paper so that a dry film thickness gradient of 20 to 300 m is formed, and then baked and cured. Next, by visual inspection, the coating film part where the black and white checkered pattern cannot be seen through is judged, the film thickness of the part is measured, and this film thickness is defined as the black and white hidden film thickness.

[0022] Specific examples of the non-transparent scale-like bright pigment include aluminum pigment, colored aluminum pigment, copper pigment, zinc pigment, iron pigment, nickel pigment, tin pigment and the like. Of these, aluminum pigments and colored aluminum pigments are preferably used. Here, the colored aluminum pigment is obtained by coating an organic or inorganic colored pigment on an aluminum pigment. The color pigment coating layer has a thickness of about 80 to about 600 nm. Examples of the color pigment coating include a wet method in which a color pigment and a polymer substance are dispersed in water and deposited on the surface of an aluminum pigment to form a colored layer.

[0023] In the present invention, it is preferable to use those non-transparent scaly glittering pigments having an average particle size of 6 to 40 m in the longest direction and an average particle size of 10 to 10 m. More preferably, it is 30 m. When the average particle size exceeds 40 m, the tip of the scaly glittering pigment may protrude from the surface of the coating film, and the finished appearance of the coating film obtained may be deteriorated. On the other hand, if the average particle size is less than 6 m, the surface concealment may be reduced. Further, as the non-transparent scaly glittering pigment, those having a thickness of 0.1 to 2 111 are preferably used.

[0024] In this specification, the "average particle size" of the pigment is generally used to indicate the particle size (whether the particle size is coarse! / Or fine), and is a laser beam. The median diameter (D), which was measured by the scattering method, was displayed.

50

[0025] The non-transparent scaly glittering pigment is preferably contained in the metallic base coating composition in an amount of 5 to 25% by mass of pigment mass concentration (PWC) in an amount of 7 to 20% by mass. More preferably it is included. If the pigment mass concentration (PWC) is less than 5% by mass, the metallic base coating film may be dulled and the underlying concealed pellets may be deteriorated. The pigment mass concentration (PWC) If it exceeds 25% by mass, the resulting coated film may have an inferior coating film appearance. The pigment mass concentration of the non-transparent scaly glitter pigment is a calculation formula that also includes the amount of the pigment other than the non-transparent scaly glitter pigment described below,

PWC (mass%) = (total mass of non-transparent scale-like glitter pigment) / (total mass of non-transparent scale-like glitter pigment and other pigments and all resin solids) X 100 force calculation Is done. The total resin means a film-forming resin and a curing agent.

[0026] In the present invention, commercially available non-transparent scaly pigments may be used. For example, as the aluminum pigment, "Alpaste" series manufactured by Toyo Aluminum Co., Ltd., "Alpaste" series manufactured by Asahi Kasei Co., Ltd. Examples of the colored aluminum pigment include the “colored aluminum” series manufactured by Toyo Anoleum and the “colored aluminum” series manufactured by Showa Aluminum.

[0027] m ^ mrn

Examples of coloring pigments that can be contained in the metallic base coating composition include various organic or inorganic coloring pigments. Examples of the coloring pigment include organic azo lake pigments, insoluble azo pigments, condensed azo pigments, diketopyrrolopyrrole pigments, benzimidazolone pigments, phthalocyanine pigments, indigo pigments, perinone pigments, Examples include perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, metal complex pigments, inorganic chrome yellow, yellow iron oxide, bengara, carbon black, and titanium dioxide. Furthermore, extender pigments such as calcium carbonate, barium sulfate, clay, aluminum powder, and talc can be added. Further, a metallic base coating film having a desired hue can be formed by using one or a combination of two or more of the above color pigments.

[0028] When the metallic base coating composition contains a colored pigment, the content of the colored pigment contained in the metallic base coating composition is preferably a pigment mass concentration (PWC) of 5 to 40 mass%. By including the coloring pigment in an amount within this range, the hue exhibited by the metallic base coating film, the hue exhibited by the My strength base coating film, and the hue exhibited by the color tailor coating film are in the color arrangement of the hue ring of the Munsell color system. It is possible to obtain a coating film having a similar color or at least an adjacent hue. If it falls below the lower limit, the background concealment will be reduced. If it exceeds the upper limit, the appearance may deteriorate. The pigment mass concentration (PWC) of the color pigment is preferably 7 to 35% by mass. The pigment mass concentration of the colored pigment is calculated using the above-mentioned non-transparent scaly glittering pigment,

PWC (mass%) = (total weight of colored pigments) / (total weight of colored pigments and other pigments and total resin solids) X 100

The force is calculated.

[0029] 'Coupling Kaisei !!

Examples of the film-forming resin contained in the metallic base coating composition include attalinole resin, polyester resin, alkyd resin, epoxy resin, polyurethane resin, and polyether resin, and particularly, acrylic resin and / or polyester resin. Is preferably used. These may be used alone or in combination of two or more. Examples of the curing agent include amino resins and (block) polyisocyanate compounds.

[0030] Examples of the acrylic resin preferably used include a copolymer of an acrylic monomer and another ethylenically unsaturated monomer. Examples of acrylic monomers that can be used for the copolymerization include methyl, ethyl, propyl, n-butanol, i-butyl, t-butyl, 2-ethylhexyl, laurinole, phenyl, benzyl, 2- Examples include esterified products such as hydroxyethyl, 2-hydroxypropyl, acrylic acid or 2-hydroxyethyl methacrylate, a prolatathone ring-opening adduct, acrylamide, methatalamide, and N-methylolacrylamide. Examples of other ethylenically unsaturated monomers copolymerizable with these include styrene, α-methylstyrene, itaconic acid, maleic acid, and butyl acetate.

[0031] Examples of the polyester resin that is preferably used include saturated polyester resins and unsaturated polyester resins, and examples include condensates obtained by heat condensation of polybasic acids and polyhydric alcohols. Examples of the polybasic acid include saturated polybasic acid and unsaturated polybasic acid. Examples of the saturated polybasic acid include phthalic anhydride, terephthalic acid, and succinic acid. Examples of the basic acid include maleic acid, maleic anhydride, fumaric acid and the like. Examples of polyhydric alcohols include divalent alcohols. Examples of the dihydric alcohol include ethylene glycol and diethylene glycol. Examples of the trihydric alcohol include glycerin and trimethylolpropane.

[0032] The ratio of the film-forming resin and the curing agent is preferably 90 to 50% by mass of the film-forming resin and 10 to 50% by mass of the curing agent in terms of solid content with respect to the total of both. It is more preferable that the resin is 85 to 60% by mass and the curing agent is 15 to 40% by mass. When the curing agent is less than 10% by mass (when the film-forming resin exceeds 90% by mass), there is a possibility that the crosslinking in the coating is not sufficient. On the other hand, when the crosslinking agent exceeds 50% by mass (when the coating film-forming resin is less than 50% by mass), the storage stability of the coating composition decreases and the curing rate increases. May get worse.

[0033] Other ingredients

In addition to the above components, the metallic base coating composition comprises an antisettling agent such as a polyamide wax which is a lubricating dispersion of an aliphatic amide or a polyethylene wax which is a colloidal dispersion mainly composed of oxidized polyethylene, a curing catalyst, Add UV absorbers, antioxidants, leveling agents, surface conditioners such as silicon and organic polymers, sagging inhibitors, thickeners, antifoaming agents, lubricants, crosslinkable polymer particles (microgels), etc. be able to. These additives can usually improve the performance of the coating composition or coating film by blending at a ratio of 15 parts by mass or less with respect to 100 parts by mass of the resin component (solid content basis).

[0034] Preparation of metallic base coating composition

The metallic base coating composition is provided in a form in which the above-mentioned constituents are usually dissolved or dispersed in a solvent. As the solvent, any organic solvent and / or water that can dissolve or disperse the resin component can be used. Examples of the organic solvent include those usually used in the paint field. For example, hydrocarbons such as hexane, toluene and xylene, ketones such as acetone and methyl ether ketone, esters such as ethyl acetate, cellosolve acetate and butylcetosolve, alcohols and the like can be exemplified. If the use of organic solvents is restricted from an environmental point of view, water is preferred. In this case, an appropriate amount of a hydrophilic organic solvent may be contained.

[0035] The method for preparing the metallic base coating composition is not particularly limited. Methods well known to those skilled in the art such as kneading and dispersing using a mill, kneader, or roll can be used.

[0036] The solid content of the metallic base coating composition is preferably 30 to 70% by mass during production, and preferably 20 to 55% by mass when coating the metallic base coating composition. .

[0037] My strength base coating composition

The My strength base coating film is formed using the My strength base coating composition. As the My strength-based coating composition, those containing a transparent scaly glittering pigment, a colored pigment, a film-forming resin, a curing agent, and the like are preferably used.

[0038] ^ mw ^ ^ -mwmm

When the strength-based paint composition contains a transparent scaly glitter pigment, the highlight strength of the resulting strength-based coating film is somewhat high and the brightness value of the strength of the strength-based coating film is high. The force s, the force s to form a coating that is lower than the highlight brightness value of the metallic base coating.

[0039] In the transparent scaly glittering pigment, "transparency" means that the black-and-white concealment film thickness of the coating film obtained when the pigment concentration (PWC) in the solid content of the paint is 25% is 100 m. That means that Specific examples of the transparent scaly glitter pigment include mica flake pigment, metal oxide-coated mica flake pigment, alumina flake pigment, metal oxide-coated alumina flake pigment, metal oxide-coated silica flake pigment, and metal oxide-coated glass. For example, flake face. Among these, mica flake pigment, metal oxide-coated myrtle pigment, alumina flake pigment, and metal oxide-coated alumina flake pigment are more preferably used.

[0040] The mica flake pigment is a pigment composed of natural muscovite or synthetic mica. The metal oxide-coated my strength pigment is a pigment in which the surface of natural muscovite or synthetic mica is coated with a thin film of titanium dioxide, iron oxide, and other metal oxides such as chromium, cobalt, tin, and zirconium. is there.

[0041] The alumina flake pigment is a pigment composed of aluminum oxide (Al 2 O 3) force.

The metal oxide-coated alumina flake pigment has a surface of aluminum oxide (Al 2 O 3). Fe Ti_〇 _2, Sn_〇 _2, is obtained by coating with a metal oxide such as Zr_〇 _2. By sharpening the particle size distribution that increases surface smoothness, scattering by reflected light can be reduced.

[0042] The metal oxide-coated silica flake pigment is obtained by coating a base made of flaky silica (silicon dioxide) with a metal oxide different from silica. Examples of the metal oxide coated here include iron oxide (iron monoxide, ferric trioxide, hematite) and titanium dioxide (anatase type or rutile type). The thickness of the metal oxide coating layer is preferably 50 to 200 nm, more preferably 60 to 180.

[0043] The metal oxide-coated glass flake pigment is a glitter pigment in which the surface of the glass flake is covered with titanium dioxide. The thickness of the pigment is 0.1 to 5 111, preferably 0.1 to 3 111. If the thickness is less than 0. m, the glittering pigment may be deformed or destroyed during coating preparation, and the coating composition may discolor over time. If it exceeds 5 πι, the coating film appearance may be deteriorated. is there.

[0044] Among the above pigments, a pigment coated with a metal oxide is sometimes referred to as an interference bright pigment. The pigment coated with these metal oxides can obtain a desired color by adjusting the kind (amount of coating) of the metal oxide to be coated.

[0045] It is preferable to use a transparent scaly luster pigment having an average particle diameter in the longest direction of 10 to 30 m and a thickness of 0.1 to 2 mm.

[0046] The transparent scaly glittering pigment is preferably contained in the My strength base coating composition in an amount of 0.25 to 15% by mass of pigment mass concentration (PWC) 0.5 to 10% by mass. It is preferable that the amount of the contained amount is as follows. When the pigment mass concentration (PWC) is less than 0.25% by mass, a laminated coating film having excellent design properties may not be obtained. If the pigment mass concentration (PWC) exceeds 15% by mass, the coating film appearance of the laminated coating film may deteriorate. The pigment mass concentration of the transparent scale-like glitter pigment is calculated using the formula including other pigments described later, PWC (mass%) = (total mass of the transparent scale-like glitter pigment) / (transparent scale-like glitter Total mass of pigment and other pigments and all resin solids) X 100

The force is calculated.

[0047] Commercially available transparent scaly luster pigments may be used. For example, white interference color As a metal oxide-coated pigment with a high molecular weight, Merck Japan's “Silary T60—10 W3J (trade name)”, “Nihon Koken” “Pearl Grace SME 90—9” (trade name), green interference color As a metal oxide-coated my strength pigment, “Iriodin Ultra 7235 W2J (trade name) manufactured by Merck Japan Co., Ltd. As a metal oxide-coated my strength pigment having a blue interference color,“ Iriodin Ultra 7225 ” W2J (trade name), a metal oxide-coated myrtle pigment having an interference color of yellow, such as “Iriojin Ultra 7205 W2J (trade name)” manufactured by Merck Japan, Inc. In addition, a metal oxide coating having interference light is used. Also included are alumina-covered flake pigments (alumina white, blue, red, green, gold).

[0048] Colored pigment

As the color pigment, the color pigments mentioned in the description of the metallic base coating composition can be used. And by setting the pigment mass concentration (PWC) of the color pigment contained in the My strength base coating composition to 0.5 to 15 mass%, the hue exhibited by the metallic base coating and the My strength base coating are exhibited. Hue and the hue force that the Color Talia coating film exhibits, the force S to obtain a coating film that has the same color or at least adjacent hues in the color arrangement of the Munsell color system.

[0049] 'Songsei Semi-Fresh, Hard Life and My Power Base'

As the film-forming resin and the curing agent contained in the My strength base coating composition, specifically, the film-forming resin and the curing agent mentioned in the description of the metallic base coating film can be used. It is more preferable to use the same type of film forming resin and curing agent as those used in the metallic base coating composition. Furthermore, other components that can be included in the metallic base coating composition can be used in the same manner. The preferred proportion of these components and the preparation of the My strength base coating composition are also the same as those of the metallic base coating composition.

[0050] The paint form of the My strength base paint used in the present invention may be any of an organic solvent type, an aqueous type (water-soluble, water-dispersible, emulsion), or a non-water-dispersed type.

[0051] The solid content of the My strength base coating composition is preferably 10 to 60% by mass at the time of production, while it is preferably 15 to 55% by mass at the time of painting. [0052] Color clear coating composition

The color tally coating is formed using a color tally coating composition. This color clear coating composition includes a color pigment, a film-forming resin, a curing agent, and the like.

Yes

[0053] As the color pigment, the color pigments mentioned in the description of the metallic base coating composition can be used. By setting the pigment mass concentration (PWC) of the color pigment contained in the color tally paint composition to 0.0;! To 10% by mass, the hue and strength of the metallic base coating film are maintained while maintaining the tally property. It is possible to obtain a coating film in which the hue exhibited by the base coating film and the hue exhibited by the color tailor coating film are similar colors or at least adjacent hues in the color arrangement of the Munsell color system.

[0054] The film-forming resin contained in the color tally coating composition is not particularly limited, and can be an acrylic resin, polyester resin, epoxy resin, polyether resin, which can be used in a metallic base coating composition. A film-forming resin such as polyurethane resin can be used. These resins can be used in combination with a curing agent such as an amino resin and / or a block isocyanate resin. From the viewpoint of transparency, a combination of an acrylic resin and / or a polyester resin and an amino resin is preferable. In addition, when a color talya coating film is used as the uppermost coating film of a laminated coating film, an acrylic resin and / or a polyester resin having a carboxylic acid / epoxy curing system are preferable.

[0055] The paint form of the color tally paint composition may be any of an organic solvent type, an aqueous type (water-soluble, water-dispersible, emulsion), and a non-aqueous dispersion type.

[0056] The solid content of the color tally paint composition is preferably 30 to 60% by mass, more preferably 35 to 55% by mass at the time of production. The solid content at the time of application of the color tally coating composition is preferably 20 to 55% by mass, more preferably 30 to 55% by mass.

[0057] Top clear coating composition

The coating form of the top tarry paint used in the present invention can be any of organic solvent type, aqueous type (water-soluble, water-dispersible, emulsion), non-water-dispersed type, and powder type. And those containing a functional resin and a curing agent as required. If necessary, a curing catalyst, a surface preparation agent, and the like can be used. As the coating film-forming resin, acrylic resin, polyester resin, epoxy resin, polyurethane resin and the like are not particularly limited. These can be used in combination with a curing agent such as an amino resin and / or a (block) isocyanate resin. Use a combination of acrylic resin and / or polyester resin and amino resin or acrylic resin and / or polyester resin with carboxylic acid / epoxy curing system from the viewpoint of transparency or acid etching resistance. It is preferable. Furthermore, the top talya paint may contain other additives as desired. Specifically, those mentioned in the description of the metallic base coating film can be used.

[0058] Development of law, law

A schematic diagram of a laminated coating film obtained by the method for forming a laminated coating film of the present invention is shown in FIG. The object to be coated 1 may have an electrodeposition coating film 3 if desired. The laminated coating film of the present invention is formed by forming the metallic base coating film 7 on the intermediate coating film 5, and then sequentially forming the My strength base coating film 9 and the color clear coating film 11. Furthermore, a top tailor coating film 13 may be formed.

[0059] Workpiece

The object to be used for forming the laminated coating film of the present invention is not particularly limited, and examples thereof include metals, plastics, foams and the like. Of these objects to be coated, metal substrates that can be coated by cationic electrodeposition are particularly preferably used. The metal substrate is not particularly limited, and examples thereof include simple metals such as iron, copper, aluminum, tin, and zinc, and alloys and forged products containing these single metals. Specifically, passenger cars, Car bodies and parts of automobiles such as trucks, motorcycles and noses.

[0060] When these metal substrates are used as the objects to be coated, it is particularly preferable that they are preliminarily subjected to chemical conversion treatment with phosphates, chromates, zirconium salts, or the like! It is preferable that an electrodeposition coating is formed on the metal substrate that has been subjected to such a chemical conversion treatment! As an electrodeposition coating composition, a cation type and an anion type can be used. By using a cationic type electrodeposition coating composition, it is possible to form a coating film having better anticorrosion properties. This is preferable because it is possible. Cationic electrodeposition coating compositions require a force S to use a commonly used coating composition.

[0061] Intermediate coating film

In the article to be used in the present invention, an intermediate coating film is formed on an electrodeposition coating film as desired. The intermediate coating film has a function of concealing undercoat defects, ensuring surface smoothness after top coating (improving appearance), and imparting physical properties of the coating film (impact resistance, chipping resistance, etc.). The intermediate coating film is formed using the intermediate coating composition. The intermediate coating composition includes various organic and inorganic color pigments and extender pigments, a film-forming resin and a curing agent.

[0062] As the color pigment used in the intermediate coating composition, for example, those described in the above-mentioned metallic base coating composition can be used. Typically, dark gray, light gray or white intermediate coating compositions with carbon black and titanium dioxide as the main pigments are used. A so-called color intermediate coating composition in which various color pigments are combined may be used.

[0063] The film-forming resin used in the intermediate coating composition is not particularly limited, and for example, those described in the above-mentioned metallic base coating composition can be used. A combination of an alkyd resin and / or polyester resin and an amino resin is preferred from the standpoint of pigment dispersibility or workability.

[0064] A metallic base coating film may be formed in an uncured state after the intermediate coating composition is applied to an object on which an electrodeposition coating film has been formed if desired. In addition, baking and curing may be performed before forming the metallic base coating film. In the case of performing baking and curing, baking can be performed at a curing temperature of 100 to; 180 ° C, preferably 120 to 60 ° C for 10 to 30 minutes.

[0065] Metallic base coating film

A metallic base coating composition is applied to an article having an intermediate coating film to form a metallic base coating film. When the object to be coated is an automobile body, multi-stage coating by air electrostatic spray coating, preferably the power to apply in two stages, or air electrostatic spray coating, commonly called “a (micro micro)” By using a coating method combined with a rotary atomizing electrostatic coating machine called “Bell”, “(Micro) Bell” or “Metal Bell”. It is preferable to form a taric base coating film. These coatings can further enhance the appearance and design of the coating film.

[0066] The film thickness of the metallic base coating film in the present invention varies depending on the desired application, but it is preferable to apply the coating so that the dry film thickness is 10 to 35 m. If the upper limit is exceeded, sharpness may be reduced, and defects such as unevenness or flow may occur during painting. If the lower limit is exceeded, the substrate may be hidden and the film may break.

[0067] After the coating of the metallic base coating composition, the following My strength base coating film is formed on the uncured metallic base coating film which may be baked and cured or not baked and cured. Also good. When the metallic base coating film is baked and cured, it is preferably baked at a curing temperature of 100 to 180 ° C, preferably 120 to 160 ° C for 10 to 30 minutes.

[0068] My strength base coating film

On the metallic base coating film thus formed, the My strength base coating film is formed using the My strength base coating composition. The My strength base coating film can be formed in the same manner as the metallic base coating film. In addition, after forming the metallic base coating film, baking curing is performed! / ,! If this is the case, the My strength base coating film will be formed wet-on-wet.

[0069] Here, wet-on-wet means that after a first coating composition (here, a metallic base coating composition) is applied to form a coating film, the coating film is not baked and cured, and a second coating is formed thereon. Applying a coating composition (here, My Strength base coating composition) to form a coating film. In this case, before applying the second coating composition, the coating film obtained from the first coating composition may be set and preheated. Setting is generally performed by leaving the coating at room temperature;! ~ 8 minutes. Preheating is generally performed by heating the coating film at 40 to 80 ° C for 2 to 10 minutes.

[0070] The film thickness of the My strength base coating film varies depending on the desired application, but it is preferable to apply the coating so that the dry film thickness is 10 to 35 m. If the upper limit is exceeded, sharpness may deteriorate, and defects such as unevenness or flow may occur during painting. If the lower limit is exceeded, the substrate cannot be concealed and film breakage may occur.

[0071] In the method for forming a laminated coating film of the present invention, the metallic base coating film obtained in this way is used. The hue that the metallic base coating film and the hue that the My strength base coating film exhibit are the same color or at least adjacent to each other in the color arrangement of the hue ring of the Munsell color system. There is a relationship.

[0072] Munsell color system is a type of system (color system) that expresses colors based on the three attributes of color. The Munsell color system is standardized as JIS Z 8721 (color display method with three attributes). Here, the three attributes mean hue, lightness, and saturation. Of the three attributes, “hue” represents the type of color. In this hue, there are five basic colors: red (R), yellow (Y), green (G), blue (B), purple (P), and their intermediate colors yellow-red (YR), yellow Divide into a total of 10 colors, including green (GY), blue-green (BG), blue purple (PB), and red purple (RP). Then, these colors are further divided by 5, and the color type is expressed with a total of 50 hues. The color ring divided into the 50 hues is called a hue circle. In this specification, “the same color or at least the adjacent hues in the color arrangement of the Munsell color system hue ring” means the same hue or adjacent colors divided into 50 hues in the Munsell color system. Means a hue that is judged as a hue.

[0073] In the formation of the multilayer coating film of the present invention, the hue exhibited by the metallic base coating film and the hue force S exhibited by the Myrtle base coating film are similar or at least adjacent to each other in the color arrangement of the hue ring of the Munsell color system. Due to the hue, it is possible to obtain a multilayer coating film that has a sense of depth and is less susceptible to variations in the film thickness of each coating film.

[0074] Note that "the hue exhibited by the metallic base coating film and the hue power exhibited by the My strength base coating film are the same colors or at least adjacent hues in the color arrangement of the Munsell color system hue ring" Hue strength of metallic base coating When the hue of the Munsell color system is classified as “5R”, it means that the hue of the My strength base coating is classified as 2.5R to 7.5R.

[0075] In the present invention, the hue exhibited by the metallic base coating film and the hue exhibited by the My strength base coating film are obtained by coating the metallic base coating composition and the My strength base coating composition, respectively, and baking and curing them. The hue is measured using the coating film obtained by the above. The coating film used for colorimetry can be prepared, for example, by applying a coating composition on a black-and-white mask paper so that the dry film thickness is 15 πι and baking it. Black and white hidden here The test paper is a black and white checkered pattern with 40 mm spacing, and its brightness is L * value 80 or more in the white part and L * value 12 or less in the black part. The color measurement of the hue of the Munsell color system in these coating films can be performed using a color difference meter of “Minolta spectrocolorimeter CM-2002” (trade name, manufactured by Minolta).

[0076] In the method for forming a laminated coating film of the present invention, the My strength base coating film is a metallic base coating film and a coating film made of My strength base coating film at 15 ° L * value S, 15 of the metallic base coating film. ° It is also characterized by the coating film formed so that the fluctuation range is -18-30% with respect to the L * value.

Here, L * is obtained in accordance with JIS Z8729. L * is L * a * b * color system (CIE

1976) is an index used to represent the color of an object to be measured. In this color system, L * represents lightness. Lightness L * means that the whiteness of the substance to be measured increases as the value increases, and the blackness increases as the value decreases. The L * value can be measured using “CM512m-3” (a variable angle color difference meter manufactured by Minolta).

[0078] The 15 ° L * value is measured by irradiating the light source from an angle of 15 ° when the light receiving portion in a position perpendicular to the coating film to be measured is 0 °. Mean value. FIG. 2 is a diagram for schematically explaining these light source irradiation angles.

[0079] 15 ° L * value of the coating consisting of the metallic base coating and the My strength base coating; of the metallic base coating; Is a state in which the lightness of the two-layer coating consisting of the metallic base coating and the My strength base coating is lower than that of the metallic base coating alone. Hue and My Strength of the Metallic Base Coating Film My hue is that the hue of the base coating film is the same color, and the brightness of the metallic base coating film and the Mybase coating film varies in the above range. By forming the base coating film, it is possible to reduce changes in the coating film appearance due to film thickness variations, and to form a laminated coating film with a sense of depth and excellent design.

[0080] The 15 ° L * value of the coating consisting of the metallic base coating and the My strength base coating is 0 18% (however, minus 18% for the 15 ° L * value of the metallic base coating. In the case of (except), the depth of the resulting laminated coating film becomes low and the design is poor. In addition, a 15 ° L * value strength metallic base film of a metallic base coating film and a My strength base coating film is used. If the fluctuation range is less than 30% with respect to the 15 ° L * value of the coating film (when the absolute value of the fluctuation range is large, for example, it is 1 to 32%), the color change of the coating film The film appearance may change due to film thickness fluctuation. Also, if the fluctuation range exceeds 0 for the 15 ° L * value S of the metallic base coating film and the 15 ° L * value of the metallic base coating film and the 15 ° L * value of the metallic base coating film, the resulting laminated coating The appearance of the film will be inferior.

[0081] 15 ° L * value of the coating consisting of the metallic base coating film and the My strength base coating film The fluctuation range is -18 to -30% with respect to the 15 ° L * value of the metallic base coating film. As a method for forming a force-based coating film, a dry film thickness of 6-; using a My-force-based coating composition in which the pigment mass concentration (PWC) of the transparent scaly glittering pigment is 0.25-15% by mass; For example, a method of forming a coating film so as to be 15 m may be mentioned.

[0082] After the application of the My strength base coating composition, the next color tally coating film may be formed either by baking and curing the coating film or without baking and curing. My strength base When the coating is baked and cured, it is preferably baked at a curing temperature of 100 to 180 ° C, preferably 120 to 160 ° C for 10 to 30 minutes.

[0083] Color clear coating

On the coating film formed of the metallic base coating film and the My strength base coating film thus formed, a color tailor coating film is formed by using the above-mentioned color tailor coating composition. The color clear coating film can be formed in the same manner as the above metallic base coating film. In addition, when baking hardening is not performed after the formation of the strength base coating film, the color tally coating film is formed wet-on-wet. In the case of applying wet-on-wet, the above-mentioned My Power base coating film may be preheated before setting the color tarpaulin coating composition. Preheating can be applied under the same conditions as the metallic base coating described above.

[0084] The thickness of the color tally coating varies depending on the desired application, but it is preferable to apply the coating so that the dry thickness is 10-60. If the upper limit is exceeded, sharpness may deteriorate, and defects such as unevenness or flow may occur during painting. If the lower limit is exceeded, the substrate may not be covered and film breakage may occur. [0085] Baking after painting of the color tally coating composition is preferably performed at a curing temperature of 100 180 ° C, preferably 120 to 160 ° C for 10 30 minutes.

[0086] In the method for forming a laminated coating film of the present invention, the hue exhibited by the color tartar coating film includes the hue exhibited by the metallic base coating film, the hue exhibited by the My strength base coating film, and the hue ring of the Mancel color system. In color arrangement, they are similar colors or at least adjacent hues. The color measurement of the hue of the coating film can be performed in the same manner as described above. When these coating films have such a hue, there is a feeling of depth and it is difficult to be subject to fluctuations in the film thickness of each coating film.

[0087] In the method for forming a laminated coating film of the present invention, the color tartar coating film has a 15 ° L * value of a coating film composed of a metallic base coating film, a My strength base coating film, and a color tailor coating film. It is also characterized in that the coating film is formed so that the fluctuation range is 1630% relative to the 15 ° L * value of the force-based coating film.

[0088] For a 15 ° L * value of a 15 ° L * value of a metallic base coating film, a My strength base coating film, and a color talya coating film, and 15 ° L * value of a metallic base coating film and a My strength base coating film Fluctuation range of 1 16 30% means that the coating strength S consists of 3 layers consisting of metallic base coating, My strength base coating and color tartar coating, S consists of metallic base coating and mybase coating 2 It is in a state where the brightness is low compared to the coating film of the layer. As described above, the color base coating film, the My strength base coating film, and the color tally coating film have similar colors, and the film thickness is formed by forming a color tally coating film whose brightness varies within the above range. It is possible to reduce changes in the appearance of the coating film due to fluctuations in the thickness, and it is possible to form a laminated coating film with a sense of depth and excellent design. The disadvantages when the fluctuation range of the 15 ° L * value is outside the range of -16-30% are the same as above.

[0089] For the 15 ° L * value of the laminated coating consisting of the metallic base coating, the My strength base coating, and the color tally coating, and the 15 ° L * value of the metallic base coating and the My strength base coating As a method for forming a color tally film with a variation range of 1 to 30%, a dry film thickness is obtained using a color tally paint composition in which the pigment mass concentration (PWC) of the colored pigment is 0.01 to 10% by mass. For example, a method of forming a coating film so as to be 10 60 m. [0090] The 15 ° L * value of the laminated coating composed of the metallic base coating, My strength base coating, and color-tally coating thus obtained is the variation width with respect to the 15 ° L * value of the metallic base coating. Is preferably 0 47%. When the fluctuation range is within this range, it is possible to obtain a coating film with less variation in coating appearance. This range of fluctuation is more preferably in the range of 37%.

[0091] The 15 ° L * value of the multilayer coating film composed of the metallic base coating film, the My strength base coating film, and the color tally coating film is preferably 20 60. When the laminated film has a 15 ° L * value of 20 60, a laminated film having a sense of depth and excellent design can be obtained. When the 15 ° L * value of the multilayer coating film is less than 20, only a coating color with a small amount of the glitter component can be designed, and the design properties of the multilayer coating film may be lowered. Also, if the 15 ° L * value of the layer coating exceeds 60, the brightness difference between the metallic coating and the color tally coating becomes too large, and the hue difference due to film thickness variation of the color tally coating may increase. There is.

[0092] Top clear coating

In the method for forming a laminated coating film according to the present invention, a top tailor coating film can be formed on the laminated coating film composed of the metallic base coating film, the My strength base coating film, and the color tailor coating film. By forming the top tailor coating, the metallic base coating, the My strength base coating, and the color tailor coating can be protected.

[0093] The top tally coating film can be formed using a top tally coating composition. As the top clear coating composition, those containing a film-forming resin and a curing agent are preferably used. As a film-forming resin and a curing agent, it is possible to use what can be used in a color tally paint composition. The top tarpaulin coating composition can be prepared in the same manner as the color tarpaulin coating composition.

[0094] Specifically, it is preferable to apply the top tally coating composition by a rotary atomizing electrostatic coating machine such as a bell or a bell described above.

[0095] The dry film thickness of the top tally coating film formed from the top tally paint is generally preferably about 10 70 111, more preferably about 20 50 111. If the upper limit is exceeded, defects such as scratches or sagging may occur during coating. Convex is hidden, it can't be done!

[0096] After forming the top-tally coating film, a cured coating film having a high degree of crosslinking can be obtained by setting the curing temperature for curing the coating film to 100 to 180 ° C, preferably 120 to 160 ° C. . If the upper limit is exceeded, the coating film may become hard and brittle, and if it is less than the lower limit, curing may not be sufficient. The curing time is a force varying with the curing temperature 120 ° C ~; 160 ° C is 10-30 minutes. The top tarpaulin coating is preferably applied wet-on-wet on the color tartar coating. The color tartar coating should be preheated before the top tarnish coating composition is applied. I can do this. Preheating can be performed under the same conditions as those for the metallic base coating film described above.

[0097] The film thickness of the multilayer coating film formed in the present invention is in many cases 30 to 300 m, preferably 50 to 250 111. If the upper limit is exceeded, film properties such as cooling and cooling cycles may be lowered, and if the lower limit is not reached, the strength of the film itself may be lowered.

Example

[0098] The ability to more specifically explain the present invention by the following examples The present invention is not limited to these. In the examples, “parts” and “%” are based on mass unless otherwise specified.

[0099] Example 1 Production of red metallic base coating composition

Stainless steel vessel, Nippon Paint Co., Ltd. acrylic resin (acid value 20 mgKOH / g, hydroxyl value 75, the number-average molecular weight of 5000, solid content 60 ^_0/0) 83. This, in advance, perindopril Mano Lane 6436 (Miles Inc. iron oxide (Red pigment) 13. Weighed 6 parts of pigment dispersion paste 96. 8 parts obtained by dispersing the pigment so that the particle size was 5 am or less, and then weighed Uban 128 (Mitsui Chemicals Butylated Melamine Resin, trade name) (Solid content 60%) 44/7 parts, aluminum paste 7640NS (Toyo Aluminum Aluminum pigment, non-transparent scaly pigment, trade name, average particle size 18 m) 9.7 parts and crosslinkable Resin particles (acrylic viscosity imparting agent manufactured by Nippon Paint Co., Ltd., average particle size 55 nm, solid content 25%) 15. Weigh 3 parts and stir with a desktop stirrer to prepare a red solvent-based metallic base coating composition did. This was used after adjusting the coating viscosity. The PWC of the non-transparent scaly luster pigment contained in the metallic base coating composition is 23.3 mass ⁰ /. Met.

[0100] Mica Base In a stainless steel container, acrylic resin made by Nippon Paint Co., Ltd. (acid value 20mgKOH / g, hydroxyl value 75, number average molecular weight 5000, solid content 60%) 83.2 parts in advance, Shinkasha Red, RT-35 5 (Ciba Charity Chemicals Red Pigment) 6 · 2 parts, Perind Maroon 6436 (Myles Iron Oxide Red Pigment) 0.4 parts were obtained by dispersing the pigment to a particle size of 5 m or less. 90.6 parts of pigment dispersion paste was weighed, and then 48.7 parts of Uban 128 (Mitsui Chemicals Butylated Melamine Resin, product name, solid content 60%), Iriodin 7215WI 1 (Merck My Power Pigment, Transparency scaly glitter pigment (trade name) 0.8 part and crosslinkable resin particles (acrylic thickener made by Nippon Paint Co., Ltd., average particle size 55nm, solid content 25%) 9. Weigh 2 parts and put on table The mixture was stirred with a stirrer to prepare a red solvent-based My strength base coating composition. This was used after adjusting to the coating viscosity. The PWC of the transparent scaly glittering pigment contained in the My strength base coating composition was 7.4% by mass.

[oioi] m m Color Clear

In a stainless steel container, Mac Flow O-1800 Talia (Nippon Paint Co., Ltd. acid'epoxy curable Talia paint, product name) is pre-loaded with Perind Maroon 6436 (Miles Co., Ltd. iron oxide red pigment) with a pigment concentration (PWC). A red solvent-type color coating composition obtained by dispersing the pigment so as to be 7% by mass was prepared and used after adjusting the coating viscosity.

[0102] m m Top Clear '^^.

MacFlow Ο— 1800 Talia (Nippon Paint Co., Ltd. Acid 'Epoxy Curing Type Talia Paint

, Trade name) was used after adjusting to the coating viscosity.

[0103] Measurement of Munsell value of coating film formed from each coating composition

Using the metallic base paint composition, My strength base paint composition and color tally paint composition obtained in the above production example, paint on black and white concealed pellets and test paper to a dry film thickness of 15 ΐη, and baked. It was. The obtained cured coating film was measured with a color difference meter of “Minolta spectrocolorimeter CM-2002” (trade name, manufactured by Minolta Co., Ltd.), and the color arrangement in the Munsell hue was measured. Here, the black-and-white cover test paper is a printed black and white checkered pattern with an interval of 40 mm, and its lightness is an L * value of 80 or more in the white part and an L * value of 12 or less in the black part. Table 1 shows the measurement results.

[0104] [Table 1] table 1

[0105] Example 1

Cathode electrodeposition paint "Power Top U-50" (manufactured by Nippon Paint Co., Ltd.) is dried on zinc oxide-treated thickness 0 · 8cm, 20 «11 30« 11 3 steel plate (Dal steel plate) Electrodeposition coating was performed so that the film thickness was 20 rn, and baking was performed at 160 ° C for 30 minutes. Next, on the obtained electrodeposition coating film, a gray intermediate coating “OLGA TO-H-880-3 Gray” (made by Nippon Paint Co., Ltd., polyester-melamine resin-based coating) was applied to a dry film thickness of 30. Spray coating was performed to m, and baking was performed at 140 ° C. for 20 minutes to prepare an object to be coated on which an intermediate coating film was formed.

[0106] On the obtained intermediate coating film, the metallic base coating composition of Production Example 1 was subjected to "Auto REA" (Lansberg) in two stages at intervals of 2 minutes so that the dry film thickness was 15 inches. It was painted with an air electrostatic coating machine. After a 10 minute interval, it was baked at 140 ° C for 20 minutes. Using “CM512m-3” (a variable angle color difference meter manufactured by Minolta Co., Ltd.), when the light receiving part in a position perpendicular to the obtained metallic base coating film is set to 0 °, the light source is turned from an angle of 15 °. L * values measured by irradiation were measured. Table 2 shows the measurement results.

[0107] Next, on the obtained metallic base coating film, the My strength base coating composition of Production Example 2 was electrostatically coated in the same manner so that the dry film thickness was 9 ΐη. Next, after setting for 7 minutes, baking was performed at 140 ° C for 20 minutes. The 15 ° L * value of the obtained coating film was measured in the same manner as described above. Table 2 shows the measurement results.

[0108] In the next stage, on the obtained My strength-based coating film, the color tarpaulin coating composition of Production Example 3 was rotated and atomized electrostatically with a μ-bell so that the dry film thickness was 37 m. Painted. A film for evaluation was prepared by baking at 140 ° C for 20 minutes. The 15 ° L * value of the obtained coating film was measured in the same manner as described above. Table 2 shows the measurement results.

[0109] In Tables 2 to 4, "Variation 1" means the 15 ° L * value (for 15 ° L * (2) for coatings composed of a metallic base coating and a mybase coating. It is the fluctuation range for the 15 ° L * value (15 ° L * (l) of the metallic base coating film, and is calculated from the following formula. Fluctuation 1 = {(15 ° L * (2))-(15 ° L * (l >>) / (15. L * (1)) X 100

“Variation 2” refers to the 15 ° L * value (15 ° L * (3) for the metallic base coating film, My strength base coating film, and color tally coating film. It is also the fluctuation range for the 15 ° L * value (15 ° L * (2) of the coating consisting of the My strength base coating, and is calculated from the following formula.

Variation 2 = {(15 ° L * (3))-(15 ° L * (2))} / (15 ° L * (2)) X 100

“Variation 3” refers to the 15 ° L * value (15 ° L * (3) of the metallic base coating, 15 ° L * value (This is the fluctuation range for 15 ° L * (l) and is calculated from the following formula.

Fluctuation 3 = {(15 ° L * (3))-(15 ° L * (l))} / (15. L * (1 >> X 100

[0110] The value of the spirit

The appearance of the laminated coating film thus obtained was evaluated by visual judgment. The evaluation criteria are as follows.

◯: The coating film can feel a depth, and the entire coating film has a uniform color.

Δ: A paint film with a slightly weak sense of depth, or a change in hue due to a change in the film thickness of the paint film.

X: Hue changes due to film thickness fluctuation of the coating film with a sense of depth.

[0111] Examples 2 to 6 and Comparative Examples:! To 7

The same procedure as in Example 1 was carried out except that the thicknesses of the metallic base coating, My strength base coating and color tally coating were changed to those shown in Tables 2 to 4, and the 15 ° L * value, appearance Evaluations were conducted in the same way. The results are shown in Tables 2-4. In Examples 2 to 6 and Comparative Examples 1 to 7, the hue of each coating film was changed by substantially changing the coating film thickness of each coating film, and occurred in each coating layer. Only the change in hue was evaluated.

[0112] [Table 2] Table 2

3]

Table 3

Example 5 Example 6 Comparative Example 1 Comparative Example 2 Metallic base

30 30 30 30

(β m)

Film thickness of my strength base coating film

9 9 9 9 (β m)

Color clear Huge film thickness

30 43 20 50!丄 m)

Metallic Hose 15 ° L * value 54. 49 54. 49 54. 49 54. 49

To My Power "-Made of Su coating film 41. 41 41. 41 41. 41 41. 41 15 ° L 氺 value

To Metalitata "To the coating film, to my strength"

15% L * value of the laminate 奠 from the coating film of Karatharia and 34. 37 28. 98 35. 12 28. 1

Fluctuation range 1 -24 -24 -24 -24 Fluctuation range 2 -17 -30 -15 -32 Fluctuation range 3-37 -47 -36 -48 Appearance evaluation of laminated coating ○ ○ Δ Δ [0114] [Table 4]

Table 4

[0115] As shown in Tables 3 to 5, the laminated coating films obtained by the examples have a sense of depth and excellent design, and the hue variation of the laminated coating film due to film thickness fluctuation is small. Met. On the other hand, in Comparative Examples 1, 4 and 5, since the change in L * value was small, the obtained multilayer coating film had a feeling of depth and poor design. In Comparative Examples 2, 3, 6 and 7, the obtained multilayer coating film in which the change in the L * value was large was felt to change in hue due to film thickness fluctuation.

Industrial applicability

[0116] The laminated coating film according to the present invention has the advantage of exhibiting a stable design by having the My strength base coating film on the metallic base coating film. The method for forming a laminated coating film according to the present invention is particularly suitable for the industrial coating of an object having a large and complicated shape such as an automobile body.

Claims

The scope of the claims

[1] A method for forming a multilayer coating film in which a metallic base coating film, a My strength base coating film, and a color clear coating film are sequentially formed on an object having an intermediate coating film, wherein the metallic base coating film exhibits The hue, the hue exhibited by the mica-based coating, and the hue force exhibited by the color-tallyer coating, in the color arrangement of the hue ring of the Munsell color system, the same colors or at least adjacent hues,

The mica base coating film has a variation range of -18 to 30% compared to the 15 ° L * value of the metallic base coating film and the 15 ° L * value of the metallic base coating film. It is a coating film formed so as to be,

The 15 ° L * value of the laminated coating consisting of the metallic base coating, the mica base coating and the color tally coating is 20 60, and

The metallic base coating composition that forms the metallic base coating film contains a non-transparent scaly glitter pigment having an average particle size of 6 40, im in an amount of 25 mass% of pigment mass concentration (PWC),

The mica-based coating composition for forming the mica-based coating film contains a transparent scaly glitter pigment in an amount of pigment mass concentration (PWC) O. 25 to 15% by mass,

The color tally coating composition for forming the color tally coating film contains a color pigment in an amount of 10% by mass of pigment mass concentration (PWC) O. 01-;

A method for forming a laminated coating film.

[2] In addition, the color tar coat is a 15 ° L * value of a laminated base film composed of a metallic base coat, a strength base coat, and a color tar coat. A coating film formed so that the fluctuation range is 16 30% with respect to the 15 ° L * value of the film, and

The 15 ° L * value of the resulting laminated coating film has a variation range of 0 47% relative to the 15 ° L * value of the metallic base coating film.

The method for forming a laminated coating film according to claim 1.

[3] A top layer coating film is further formed on the multilayer coating film formed by the method for forming a multilayer coating film according to claim 1 or 2 using a top tailor coating composition. Product consisting of Formation method of layer coating film.

A multilayer coating film formed by the method for forming a multilayer coating film according to claim 1.