Painted articles and methods for manufacturing the same

Abstract

To provide a coated article having excellent feeling of depth in color, and a method for producing the article.SOLUTION: A coated article comprises an object to be coated and a multilayer coating film, and the multilayer coating film comprises a photoluminescent coating film including photoluminescent pigment and a colored coating film including coloring pigment and a clear coating film, where a ratio (L*15 / L*110) between lightness L*15 based on spectral reflectance in which light I45 irradiated on a surface of the multilayer coating film from the angle of 45 degrees is received at the angle of 15 degrees to specular reflection light, and lightness L*110 based on spectral reflectance in which the light I45 is received at the angle of 110 degrees to specular reflection light is 5 or more and 9 or less, and a ratio (C*15 / C*110) between chroma C*15 in the L*C*h color system based on spectral reflectance in which the light I45 is received at the angle of 15 degrees to specular reflection light, and chroma C*110 in the L*C*h color system based on spectral reflectance in which the light I45 is received at the angle of 110 degrees to specular reflection light is 8 or more and 12 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to painted articles and a method for manufacturing the same. [Background technology]

[0002] In industrial product fields such as automotive paint, there is a demand for a wide variety of colors and designs to suit user preferences. One example of such a design is a multi-layer coating in which a color clear coating containing a color pigment is laminated on a coating film containing a glossy pigment and / or a color pigment (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-042891 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Such multi-layer coatings allow the color and / or reflected light of the lower coating to be seen through the color clear coating applied to the upper layer, thus creating a sense of depth in color. The object of the present invention is to provide a painted article having an even better sense of color depth and a method for manufacturing the same. [Means for solving the problem]

[0005] To solve the above problems, the present invention provides the following embodiments. [1] A painted article comprising a workpiece and a multi-layer coating, The aforementioned multi-layer coating film is A glossy coating film is formed on the aforementioned object to be coated, and contains a glossy pigment. A colored coating film containing a coloring pigment is formed on the aforementioned glossy coating film, The system comprises a clear coating formed on the aforementioned colored coating, Light I irradiated at an angle of 45 degrees with respect to the surface of the multilayer coating film * is the lightness L based on the spectral reflectance received at an angle of 15 degrees with respect to the specularly reflected light * 15 and the light I 45 is the lightness L based on the spectral reflectance received at an angle of 110 degrees with respect to the specularly reflected light * 110 and the ratio (L * 15 / L * 110 ) is 5 or more and 9 or less, the light I 45 is the L * C * chroma C in the h color system based on the spectral reflectance received at an angle of 15 degrees with respect to the specularly reflected light * 15 and the light I 45 is the L * C * chroma C in the h color system based on the spectral reflectance received at an angle of 110 degrees with respect to the specularly reflected light * 110 and the ratio (C * 15 / C * 110 ) is 8 or more and 12 or less, a coated article

[0006] [2] Light GI irradiated at an angle of 45 degrees with respect to the surface of the bright coating film 45 ​​​​​​​​​​​​​​​​​​​​​​​​15 And the aforementioned optical GI 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to the specularly reflected light, L * C * saturation GC in the h color system * 110 Ratio to (GC) * 15 / GC * 110 The painted article described in [1] above, wherein the ratio is 15 or more and 35 or less.

[0007] [3] The coated article according to [1] or [2] above, wherein the thickness of the glossy coating film is 3 μm or more and 7 μm or less.

[0008] [4] The coated article according to [1] or [2] above, wherein the lustrous pigment comprises flaky aluminum particles.

[0009] [5] The coated article according to [4] above, wherein the flake-like aluminum particles have an average particle diameter of 8 μm or more and 13 μm or less, and a thickness of 0.08 μm or more and 0.2 μm or less.

[0010] [6] The coated article according to [1] or [2] above, wherein the luminous pigment comprises vapor-deposited chromium oxide.

[0011] [7] A step of applying a glossy pigment dispersion containing a glossy pigment onto a substrate to form an uncured glossy coating film, The process involves applying a colored paint containing a coloring pigment onto the uncured glossy coating to form an uncured colored coating, The process involves applying a clear coating to the uncured colored coating to form an uncured clear coating, The process includes a step of curing the uncured glossy coating film, the uncured colored coating film, and the uncured clear coating film to obtain a multi-layer coating film, Light I was irradiated onto the surface of the multilayer coating film at a 45-degree angle. 45The brightness L is based on the spectral reflectance obtained by receiving light at a 15-degree angle to specularly reflected light. * 15 And, the aforementioned light I 45 The brightness L is based on the spectral reflectance obtained by receiving light at an angle of 110 degrees to specularly reflected light. * 110 Ratio (L * 15 / L * 110 ) is between 5 and 9, The aforementioned optical I 45 Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L * C * Saturation C in the h color system * 15 And, the aforementioned light I 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to the specularly reflected light, L * C * Saturation C in the h color system * 110 The ratio (C * 15 / C * 110 A method for manufacturing painted articles, wherein the ratio is 8 or more and 12 or less.

[0012] [8] The method for manufacturing a painted article according to [7] above, wherein the solid content of the luminous pigment dispersion is 16% by mass or more and 20% by mass or less.

[0013] [9] The method for manufacturing a painted article according to [7] or [8] above, wherein the clear coating is a two-component coating comprising a hydroxyl group-containing resin and a polyisocyanate compound. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a painted article having particularly excellent depth of color and a method for manufacturing the same. [Brief explanation of the drawing]

[0015] [Figure 1] This is a diagram illustrating the angle of light reception.

Best Mode for Carrying Out the Invention

[0016] [Painted Article] The “depth” of a color can be rephrased as, for example, the “depth” or “three-dimensionality” of the color. When the brightness (lightness) and vividness (chroma) of a color change significantly depending on the viewing angle, the depth or three-dimensionality of that color can be felt, and it can be felt as a deep color.

[0017] Lightness and chroma each represent different properties (attributes) of a color. Generally, as the lightness increases, the chroma decreases. That is, the rate of change of lightness and the rate of change of chroma are in an inverse relationship.

[0018] The painted article of the present disclosure realizes the compatibility of a large lightness change rate and a large chroma change rate. The painted article of the present disclosure includes a substrate and a multilayer coating film. The multilayer coating film is formed on the substrate and includes a luminous coating film containing a luminous pigment, a colored coating film formed on the luminous coating film and containing a colored pigment, and a clear coating film formed on the colored coating film. Light I irradiated from an angle of 45 degrees with respect to the surface of the multilayer coating film 45 is based on the lightness L based on the spectral reflectance received at an angle of 15 degrees with respect to the specularly reflected light * 15 and light I 45 is based on the lightness L based on the spectral reflectance received at an angle of 110 degrees with respect to the specularly reflected light * 110 The ratio (L * 15 / L * 110 ) is 5 or more and 9 or less. Further, light I 45 is based on L based on the spectral reflectance received at an angle of 15 degrees with respect to the specularly reflected light * C * The chroma C in the LCh color system * 15 and light I 45 is based on L based on the spectral reflectance received at an angle of 110 degrees with respect to the specularly reflected light * C * The chroma C in the LCh color system * 110 The ratio (C *15 / C * 110 ) is 8 or more and 12 or less. Thereby, an excellent color depth feeling can be obtained.

[0019] (Brightness L * 15 , L * 110 ) In the present disclosure, the change rate of the brightness of the multilayer coating film is represented by the ratio (L * 15 and brightness L * 110 (L * 15 / L * 110 ) of brightness L at two different points. In the present disclosure, L * 15 / L * 110 is 5 or more and 9 or less. That L * 15 / L * 110 is within this range means that the brightness L changes greatly depending on the viewing angle.

[0020] Brightness L * 15 is the brightness L in the L 45 Ch color system calculated from the spectral reflectance obtained by receiving light I * C * h that is incident on the multilayer coating film at an incident angle of 45° from the clear coating film side at an angle of 15° with respect to the specularly reflected light. * Similarly, brightness L * 110 is also the brightness L in the L 45 Ch color system calculated from the spectral reflectance obtained by receiving light I * C * h that is incident on the multilayer coating film at an incident angle of 45° from the clear coating film side at an angle of 110° with respect to the specularly reflected light. * is.

[0021] L * C * In the L * Ch color system, L *represents saturation, and h represents the hue angle. Lightness L * As the numerical value increases, the brightness of the substance being measured increases, and as the numerical value decreases, the darkness increases.

[0022] L * 15 / L * 110 It may be 5.5 or higher, 6 or higher, or 6.5 or higher. * 15 / L * 110 It may be 8.5 or less, 8 or less, and 7.5 or less.

[0023] L * C * The h color system is CIEL * a * bColor system (CIE1976L * a * b * Calculated based on the color space. CIE1976L * a * b * The color space can be determined in accordance with JIS Z 8781-4. CIEL * a * The b color system was established by the International Commission on Illumination and is described in Section 4.2 of CIE Publication 15.2 (1986). Lightness L * 15 and brightness L * 110 This can be acquired, for example, using a multi-angle colorimeter (e.g., BYK-mac i, manufactured by BYK-Gardner).

[0024] A light-receiving angle of 15° is a so-called highlight condition, and has a light intensity of L that is lower than that of shade and face conditions. * It tends to be high. Brightness L * 15 This can be said to represent brightness under conditions where brightness is more easily perceived. Brightness L * 15The rate of change in brightness tends to be large, and therefore it may be 10 or more, and may be 15 or more. Brightness L * 15 From a similar perspective, it may be 30 or less, or 25 or less.

[0025] A light-receiving angle of 110° is a so-called shade condition, and the brightness L * 110 This can be said to represent brightness under conditions where brightness is less easily perceived. Brightness L * 110 From a similar perspective, it may be 0 or greater, or 2 or greater. Brightness L * 110 From a similar perspective, it may be 6 or less, or 4 or less.

[0026] (Saturation C * 15 , C * 110 ) In this disclosure, the rate of change in the saturation of a multi-layer coating is defined as saturation C * 15 and saturation C * 110 The ratio (C * 15 / C * 110 ) is expressed by. In this disclosure, the C of the multilayer coating film * 15 / C * 110 It is between 8 and 12. * 15 / C * 110 The fact that it falls within this range means that the saturation C changes significantly depending on the viewing angle.

[0027] Saturation C * 15 This is light I incident on the multilayer coating from the clear coating side at an incident angle of 45°. 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 15° to the specularly reflected light, L * C * Saturation C in the h color system * This is the case. Saturation C *110 Similarly, light I incident on the multilayer coating from the clear coating side at an incident angle of 45° 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 110° to the specularly reflected light, L * C * Saturation C in the h color system * That is the case.

[0028] L * C * In the h color system, saturation C * The larger the color, the more vibrant it becomes, and as it gets smaller, the duller it becomes.

[0029] C * 15 / C * 110 It may be 8.5 or higher, and it may be 9 or higher. C * 15 / C * 110 It may be 11 or less, and it may be 10 or less.

[0030] Saturation C * 15 Since the rate of change in saturation tends to be large, it may be 35 or higher, and may be 40 or higher. Saturation C * 15 From a similar perspective, it may be 55 or less, or 50 or less.

[0031] Saturation C * 110 From a similar perspective, it may be 1 or more, and may be 3 or more. Saturation C * 110 From a similar perspective, it may be 9 or less, or 7 or less.

[0032] Figure 1 illustrates the light reception angle. Light I is irradiated from a 45-degree angle to the surface of the multi-layer coating. 45 The specularly reflected light is shown by R0. Light I 45 Light received at a 15-degree angle to the specularly reflected light is R 15 This is shown. Light R 15 From the spectral reflectance, the brightness L* 15 and saturation C * 15 This is calculated. Optical I 45 Light received at an angle of 110 degrees to the specularly reflected light is R 110 This is shown. Light R 110 From the spectral reflectance, the brightness L * 110 and saturation C * 110 This is calculated.

[0033] (Particle-like Si 15 ) To enhance the depth of color, it is desirable to minimize the diffuse reflection of light by the multi-layer coating. For example, light incident on the multi-layer coating at an incident angle of 15° is imaged from the direction normal to the multi-layer coating, and the value obtained by analyzing it with a specific image analysis algorithm (hereinafter referred to as particle sensitivity Si) is obtained. 15 This is referred to as [the value]. When [the value] is 4 or less, the sense of color depth is further enhanced. The above image analysis algorithm uses a brightness level histogram.

[0034] Particle-like Si 15 This can be acquired using a multi-angle colorimeter (e.g., BYK-mac i, manufactured by BYK-Gardner). 15 The values ​​are the particle sensitivity Si of five different samples. 15 This is the average value.

[0035] Particle-like Si 15 It may be 3.6 or less, and 3.3 or less. Particle sensitivity Si 15 It may be 2.4 or higher, and it may be 2.7 or higher.

[0036] (subject to be coated) Examples of objects to be coated include at least a part of the body of a passenger car, truck, bus, etc. Examples of materials for the objects to be coated include metals containing iron, copper, aluminum, tin, zinc, or alloys thereof. The objects to be coated may be in the form of a plate or have a three-dimensional shape. The coated article according to this disclosure constitutes, for example, at least a part of an automobile.

[0037] The object to be coated may be degreased and / or surface treated. Examples of surface treatments include phosphate treatment, chromate treatment, zirconium conversion treatment, and composite oxide treatment. After surface treatment, the metal material may be primed with an electrodeposited coating. The electrodeposited coating may be cationic or anionic.

[0038] (Glitter coating film) The glossy coating contains glossy pigments. The glossy coating conceals the texture and color of the substrate and gives a metallic texture to the multi-layer coating. The rate of change in brightness and saturation of the glossy coating affects the rate of change in brightness and saturation of the multi-layer coating. The glossy coating is formed by a glossy pigment dispersion (X). The glossy pigment dispersion (X) will be described later.

[0039] <Lightness GL * 15 , GL * 110 > The rate of change in brightness of a glossy coating is the brightness GL. * 15 and brightness GL * 110 Ratio to (GL) * 15 / GL * 110 It can be represented by ).

[0040] Brightness GL * 15 This is a photon GI (Glow-in-the-Dark) photon irradiated onto a glossy coating film at an incident angle of 45°. 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 15° to the specularly reflected light, L * C * Lightness L in the h color system * This is the brightness GL. * 110 Similarly, when light GI is incident on a glossy coating film at an incident angle of 45°... 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 110° to the specularly reflected light, L * C * Lightness L in the h color system *This is the brightness GL. * This is measured using a coated plate on which only the cured glossy coating film is placed.

[0041] Brightness GL of glossy coating film * 15 and brightness GL * 110 Ratio to (GL) * 15 / GL * 110 ) is, for example, 15 to 25. * 15 / GL * 110 Within this range, the rate of change in brightness of the multi-layer coating tends to be larger.

[0042] GL * 15 / GL * 110 It may be 17 or older, or 18 or older. GL * 15 / GL * 110 It may be 24 or less, and it may be 23 or less.

[0043] Brightness GL * 15 The value may be 35 or higher, and may be 40 or higher, as it tends to have a large rate of change in brightness. * 15 From a similar perspective, it may be 55 or less, or 50 or less.

[0044] Brightness GL * 110 From a similar perspective, it may be 1 or more, or 2 or more. Brightness GL * 110 From a similar perspective, it may be 11 or less, or 9 or less.

[0045] <Saturation GC * 15 , GC * 110 > The rate of change in saturation of a glossy coating is saturation GC.* 15 and saturation GC * 110 The ratio (C * 15 / C * 110 It can be represented by ).

[0046] Saturation GC * 15 This is a photon GI (Glow-in-the-Dark) photon irradiated onto a glossy coating film at an incident angle of 45°. 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 15° to the specularly reflected light, L * C * Saturation C in the h color system * This is the case. Saturation GC * 110 Similarly, when light GI is incident on a glossy coating film at an incident angle of 45°... 45 This is calculated from the spectral reflectance of the specularly reflected light received at an angle of 110° to the specularly reflected light, L * C * Saturation C in the h color system * This is the case. Saturation GC * This is measured using a coated plate on which only the cured glossy coating film is placed.

[0047] GC * 15 / GC * 110 For example, it is between 15 and 35. GC * 15 / GC * 110 Within this range, the rate of change in the saturation of the multi-layer coating tends to be larger.

[0048] GC * 15 / GC * 110 It may be 18 or older, 20 or older, or 22 or older. GC * 15 / GC * 110 It may be 32 or less, 30 or less, or 27 or less.

[0049] Saturation GC * 15 The saturation GC is such that the rate of change in saturation tends to be large, and it may be 15 or higher, and may be 20 or higher. * 15 From a similar perspective, it may be 35 or less, or 30 or less.

[0050] Saturation GC * 110 From a similar perspective, it may be 0 or greater, or 0.5 or greater. (Saturation GC) * 110 From a similar perspective, it may be 2 or less, or 1.5 or less.

[0051] In particular, the brightness GL of the glossy coating film * 15 and brightness GL * 110 Ratio to (GL) * 15 / GL * 110 ) is between 15 and 25, and the saturation GC * 15 and saturation GC * 110 Ratio to (GC) * 15 / GC * 110 ) may be between 5 and 35.

[0052] <Concealing properties> The depth of color can be improved by the opacity of the glossy coating, as the influence of the substrate's (the object being coated) color becomes smaller.

[0053] The opacity of a glossy coating is evaluated, for example, by the black-and-white opacity film thickness. The black-and-white opacity film thickness is measured using opacity test paper compliant with JIS K 5600-4-1(b). A glossy pigment dispersion is spray-coated onto the 2x2cm black-and-white checkerboard pattern on the opacity test paper so that a gradient of dry film thickness is created, and then it is heat-cured. Next, the point where the black-and-white checkerboard pattern is no longer visible is determined by visual inspection, and the film thickness at that point is measured. This measured film thickness is the black-and-white opacity film thickness. The smaller the black-and-white opacity film thickness, the higher the opacity.

[0054] The black-and-white opacity film thickness of the glossy coating may be 9 μm or less, 7 μm or less, or 6 μm or less. In this case, the glossy coating can be said to have high opacity.

[0055] <Light transmittance> Low light transmittance is desirable. Electrodeposited coatings typically formed on metal substrates have low light resistance. Low light transmittance of the glossy coating reduces the amount of light reaching the electrodeposited coating, thereby suppressing its deterioration. This also suppresses peeling at the interface between the glossy coating and the electrodeposited coating.

[0056] The light transmittance of the glossy coating film at wavelengths of 400-700 nm may be 0.25% or less, 0.15% or less, or 0.10% or less. In this case, the glossy coating film can be said to have low light transmittance. The light transmittance may be 0.15% or less at any wavelength between 400 and 700 nm.

[0057] The light transmittance of a glossy coating is measured at 10 nm intervals by irradiating a film formed from a glossy pigment dispersion (glossy coating alone after curing) with light of wavelengths from 400 to 700 nm using a spectrophotometer (Hitachi U-3310).

[0058] <Luminous Pigments> Luminous pigments are not particularly limited as long as they reflect light. Examples of lustrous pigments include metal particles. Specifically, these include particles of aluminum, copper, zinc, iron, nickel, tin, aluminum oxide, chromium oxide, and alloys containing these materials. These can be used individually or in combination of two or more. The lustrous pigment may be colored.

[0059] The flaky pigment may be a flaky pigment or a flaky metal particle, as diffuse reflection is easily suppressed. The aspect ratio of the flaky pigment is, for example, 2 or more. The aspect ratio is the ratio (major axis / thickness) of the major axis of one major surface of the flaky pigment to the distance (thickness) between the two major surfaces of the flaky pigment. The aspect ratio of the flaky pigment may be between 10 and 1000.

[0060] The glossy coating film may contain other glossy pigments (glossy pigments with an aspect ratio of less than 2) along with the flake-like glossy pigment. However, the content of the other glossy pigments may be 10% by mass or less, or 5% by mass or less, of the total glossy pigments.

[0061] In terms of obtaining a high level of brilliance with a small amount, the aluminum particles may be in the form of flakes, or they may be flakes of chromium oxide (deposited chromium oxide) obtained by forming a film by vapor deposition and then crushing it.

[0062] Flake-shaped aluminum particles and vapor-deposited chromium oxide may be used in combination. In this case, the mixing ratio, by mass, may be flake-shaped aluminum particles / vapor-deposited chromium oxide = 99 / 1 to 90 / 10.

[0063] The average particle size of the flaky aluminum particles may be between 8 μm and 13 μm, as this easily improves the luster. The average particle size of the flaky aluminum particles may be 8.2 μm or more, or 8.5 μm or more. The average particle size of the flaky aluminum particles may be 12.8 μm or less, or 12.5 μm or less.

[0064] The average particle diameter refers to the volume-average particle diameter D50. The volume-average particle diameter D50 is the 50% average particle diameter (D50) in a volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer (for example, Nikkiso Co., Ltd.'s "Microtrac UPA150").

[0065] The thickness of the flaky aluminum particles may be between 0.08 μm and 0.2 μm. This allows for a thinner glossy coating, potentially further improving the glossiness. The thickness of the flaky aluminum particles may be between 0.09 μm and 0.1 μm. The thickness of the flaky aluminum particles may be between 0.19 μm and 0.18 μm.

[0066] The thickness of the flake-like lustrous pigment may also be calculated by observing a cross-section of the multilayer coating film in the thickness direction using an electron microscope. In the observation field, the region corresponding to the lustrous pigment and the other regions are binarized using image processing software. Next, 20 lustrous pigments are arbitrarily selected, and the length of the thickest part of each is measured. The average of these measurements is the thickness of the flake-like lustrous pigment.

[0067] The flaky aluminum particles may have an average particle diameter of 8 μm or more and 13 μm or less, and a thickness of 0.08 μm or more and 0.2 μm or less.

[0068] The average particle size of vapor-deposited chromium oxide may be 10 μm or more and 20 μm or less. The average particle size of vapor-deposited chromium oxide may be 11.0 μm or more and 12.0 μm or more. The average particle size of vapor-deposited chromium oxide may be 19.0 μm or less and 16.0 μm or less.

[0069] The thickness of the deposited chromium oxide may be 0.01 μm or more and 0.3 μm or less. The thickness of the deposited chromium oxide may be 0.012 μm or more and 0.013 μm or more. The thickness of the deposited chromium oxide may be 0.28 μm or less and 0.25 μm or less.

[0070] <thickness> The thickness of the glossy coating may be between 3 μm and 7 μm. This may improve the orientation of the glossy pigment. The thickness of the glossy coating may be 3.5 μm or more, or 4 μm or more. The thickness of the glossy coating may be 6.5 μm or less, or 6 μm or less. The thickness of the glossy coating is the thickness after drying or curing.

[0071] The thickness of the coating film is measured, for example, by an electromagnetic film thickness gauge. The thickness of the glossy coating film is the average of the glossy coating film thicknesses in five different samples. The thicknesses of other layers can be measured and calculated in a similar manner.

[0072] (Colored coating) The colored coating contains colored pigments. The colored coating gives the painted article the desired color. The colored coating is formed by a colored paint (Y). The colored paint (Y) will be described later.

[0073] <Coloring pigments> Examples of coloring pigments include organic coloring pigments such as azo chelate pigments, insoluble azo pigments, condensed azo pigments, diketopyrrolopyrrole pigments, benzimidazolon pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, dioxane pigments, quinacridone pigments, isoindolinone pigments, and metal complex pigments; and inorganic coloring pigments such as lead yellow, yellow iron oxide, red iron oxide, carbon black, and titanium dioxide. These can be used individually or in combination of two or more.

[0074] The primary particle size of the coloring pigment may be between 10 nm and 300 nm from the viewpoint of opacity. The primary particle size of the coloring pigment may be 30 nm or larger. The primary particle size of the coloring pigment may be 100 nm or smaller. The primary particle size can be measured from electron microscope images of the cross-section of the multi-layer coating film using image processing software.

[0075] <thickness> The thickness of the colored coating is, for example, 4 μm or more and 20 μm or less. The thickness of the colored coating may be 6 μm or more, or 8 μm or more. The thickness of the colored coating may be 17 μm or less, or 15 μm or less.

[0076] (Clear coating) The clear coating protects the glossy coating and the colored coating. The clear coating is not particularly limited and has the same structure as conventionally known clear coatings. The clear coating is formed by a clear paint (Z). The clear paint (Z) will be described later.

[0077] <thickness> The thickness of the clear coating may be between 10 μm and 50 μm, in which scratch resistance is improved and the depth of color is not easily impaired. The thickness of the clear coating may be 15 μm or more. The thickness of the clear coating may be 40 μm or less.

[0078] [Method for manufacturing painted articles] The painted articles according to this disclosure are manufactured by forming a glossy coating, a colored coating, and a clear coating on a substrate in this order. When the colored coating is formed, the glossy coating may be cured or uncured. When the clear coating is formed, the colored coating may be cured or uncured. In particular, it is preferable to laminate each coating without curing them and then heat them to cure all three uncured coatings simultaneously, as this can further improve the depth of color. This method can also improve productivity, adhesion, and water resistance.

[0079] The painted article according to this disclosure is manufactured by a method comprising, for example, the steps of: applying a glossy pigment dispersion (X) onto an object to be painted to form an uncured glossy coating film; applying a colored paint onto the uncured glossy coating film to form an uncured colored coating film; applying a clear paint onto the uncured colored coating film to form an uncured clear coating film; and curing the uncured colored coating film, the uncured glossy coating film, and the uncured clear coating film to obtain a multi-layer coating film.

[0080] The formed multilayer coating film is L * 15 / L * 110 If it is 5 or more and 9 or less, C * 15 / C * 110 The value is between 8 and 12.

[0081] (1) Steps to form an uncured glossy coating film A glossy pigment dispersion (X) is applied to the object to be coated to form an uncured glossy coating film.

[0082] Examples of painting methods include air spray painting, airless spray painting, rotary atomization painting, and curtain coating painting. These methods may also be combined with electrostatic painting. Among these, rotary atomization electrostatic painting is preferred from the viewpoint of coating efficiency. For rotary atomization electrostatic painting, rotary atomization electrostatic painting machines commonly known as "micro-microbell (μμbell)", "microbell (μbell)", or "metallicbell (metabell)" are used.

[0083] The lustrous pigment dispersion (X) is applied, for example, such that the thickness of the lustrous coating in the resulting multilayer coating is between 3 μm and 7 μm.

[0084] After applying the glossy pigment dispersion (X), pre-drying may be performed. This rapidly reduces the fluidity of the glossy coating, making it easier to suppress the flow of the glossy pigment. Furthermore, pre-drying suppresses the mixing of the uncured glossy coating and the colored paint (Y) to be applied to it, making it difficult for a mixed layer to form. As a result, the appearance of the resulting multi-layer coating can be improved.

[0085] Pre-drying methods include, for example, leaving the product at a temperature of 20°C to 25°C for 15 to 30 minutes, or heating it at a temperature of 50°C to 100°C for 30 seconds to 10 minutes.

[0086] (Glitter pigment dispersion (X)) The glossy coating film is formed by a glossy pigment dispersion (X). The glossy pigment dispersion (X) may be aqueous or solvent-based. An aqueous system means that the proportion of water in the total solvent is 50% by mass or more. A solvent-based system means that the proportion of organic solvent in the total solvent is 50% by mass or more.

[0087] The lustrous pigment dispersion (X) contains the above-mentioned lustrous pigment. The lustrous pigment dispersion (X) optionally contains resin components and solvents. The lustrous pigment dispersion (X) is prepared by diluting a mixture of the lustrous pigment, as well as resin components and various additives, with a solvent.

[0088] The viscosity of the luminous pigment dispersion (X), as measured by a Type B viscometer at 20°C, may be, for example, 3000 cps / 6 rpm or more and 15000 cps / 6 rpm or less.

[0089] The solid content of the lustrous pigment dispersion (X) affects the discharge rate of the paint composition during application. Changes in the discharge rate alter the droplet size of the paint composition, affecting the orientation of the lustrous pigment. GL * 15 / GL * 110 Set the value to 15 or more and 25 or less, GC * 15 / GC * 110 In terms of being easy to adjust to 15 to 35, the solid content of the lustrous pigment dispersion (X) may be 16% by mass or more and 20% by mass or less. This is particularly important for GL * 15 / GL * 110 The ratio is easily adjusted to between 15 and 25. The solid content of the lustrous pigment dispersion (X) may be 16.5% by mass or more, and may be 17% by mass or more. The solid content of the lustrous pigment dispersion (X) may be 19.5% by mass or less, and may be 19% by mass or less. The solid content of the lustrous pigment dispersion (X) is the total components of the lustrous pigment dispersion (X) excluding the solvent.

[0090] The PWC (pigment mass concentration) of the lustrous pigment may be 5.0% by mass or more and 25.0% by mass or less. The PWC of the lustrous pigment may be 7.0% by mass or more and 10.0% by mass or more. The PWC of the lustrous pigment may be 23.0% by mass or less, 20.0% by mass or less and 15.0% by mass or less.

[0091] PWC (Pigment Mass Concentration) is the mass ratio of the pigment to the total mass of the resin solids and the target pigment (in the above case, the luminous pigment) contained in the paint. The resin solids refer to the solids of the resin components (see below) contained in the paint.

[0092] • Resin components The lustrous pigment dispersion (X) may contain a resin component. Examples of the resin component include thermosetting resins. The resin component may further contain a curing agent.

[0093] The content of the resin component may be, for example, 30% by mass or more and 75% by mass or less of the total solid content of the luminous pigment dispersion (X). The above content of the resin component may be 35% by mass or more and 40% by mass or more. The above content of the resin component may be 70% by mass or less and 66% by mass or less.

[0094] Thermosetting resins are formed, for example, from a crosslinkable functional group and a base resin. Examples of crosslinkable functional groups include carboxyl groups, hydroxyl groups, epoxy groups, silanol groups, and (meth)acryloyl groups.

[0095] Examples of base resins include acrylic resins, polyester resins, alkyd resins, polyurethane resins, epoxy resins, and fluororesins. The epoxy resin may be a urethane-modified epoxy resin. The polyester resin may be a urethane-modified polyester resin. The acrylic resin may be a urethane-modified acrylic resin. Each urethane-modified resin has urethane bonds in its resin skeleton. These can be used individually or in combination of two or more. Among these, acrylic resins and urethane-modified polyesters may be used because they offer improved chipping resistance.

[0096] Acrylic resins can be obtained, for example, by copolymerizing (meth)acrylic acid esters having functional groups such as α,β-ethylenically unsaturated carboxylic acids, hydroxyl groups, amide groups, and methylol groups, with other (meth)acrylic acid esters and styrene.

[0097] Urethane-modified polyesters are obtained by the reaction of a hydroxyl group-containing polyester with an aliphatic diisocyanate compound. The hydroxyl group-containing polyester is prepared by polycondensation of an acid component, such as a polycarboxylic acid and / or acid anhydride, with a polyhydric alcohol. Examples of aliphatic diisocyanate compounds include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, and methylcyclohexane diisocyanate.

[0098] When water is used as the solvent, a thermosetting resin having hydrophilic groups may be used. By neutralizing the hydrophilic groups of the thermosetting resin to form an alkali salt, the thermosetting resin becomes water-soluble or water-dispersible. Examples of hydrophilic groups include carboxyl groups, hydroxyl groups, methylol groups, amino groups, sulfonic acid groups, and polyoxyethylene bonds. Examples of neutralizing agents include alkaline substances such as sodium hydroxide and amine compounds.

[0099] A thermosetting resin can be prepared in a water-dispersed state by emulsion polymerization of a raw material monomer of the thermosetting resin in the presence of a surfactant or a water-soluble resin. Alternatively, the thermosetting resin may be water-dispersed with an emulsifier. In these cases, the thermosetting resin may not contain a hydrophilic group, or may contain a small amount of a hydrophilic group.

[0100] Examples of the curing agent include amino resins, urea resins, polyisocyanate compounds, epoxy group-containing compounds, carboxy group-containing compounds, carbodiimide group-containing compounds, hydrazide group-containing compounds, and semicarbazide group-containing compounds. The polyisocyanate compound includes a blocked polyisocyanate compound in which an isocyanate group is blocked with a blocking agent. These are used alone or in combination of two or more. Among them, it may be an amino resin and / or a polyisocyanate compound in terms of various performances and costs of the obtained coating film.

[0101] The amino resin is obtained, for example, by condensing an amino compound such as melamine, benzoguanamine or urea with formaldehyde and further etherifying with a lower monohydric alcohol. Details of the polyisocyanate compound will be described later.

[0102] The content of the curing agent is not particularly limited. In terms of curability, the solid content mass of the curing agent may be 10% by mass or more and 40% by mass or less of the total of the solid content mass of the thermosetting resin and the solid content mass of the curing agent. The above solid content mass of the curing agent may be 15% by mass or more. The above solid content mass of the curing agent may be 30% by mass or less, and may be 25% by mass or less.

[0103] The content of the thermosetting resin is not particularly limited. When a curing agent is included, the solid content mass of the thermosetting resin may be 60% by mass or more and 90% by mass or less of the total of the solid content mass of the thermosetting resin and the solid content mass of the curing agent. The above solid content mass of the thermosetting resin may be 70% by mass or more. The above solid content mass of the thermosetting resin may be 85% by mass or less.

[0104] ·solvent The solvent may be water (deionized water), an organic solvent, or a combination thereof. In particular, from the viewpoint of low VOC (Volatile Organic Compounds), water may be used. That is, the lustrous pigment dispersion (X) may be aqueous. In the aqueous lustrous pigment dispersion (X), the proportion of water in the solvent is 50% by mass or more, and may be 80% by mass or more.

[0105] Examples of organic solvents include ester-based solvents such as ethyl acetate, butyl acetate, isopropyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; Examples of solvents include ether-based solvents such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, methyl methoxybutanol, ethoxypropanol, ethylene glycol isopropyl ether, ethylene glycol-t-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methoxybutanol, and propylene glycol monobutyl ether; alcohol-based solvents such as methanol, ethanol, butanol, and propyl alcohol; ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon-based solvents such as Swarzol, Shellzol, and mineral spirits; and aromatic solvents such as xylene, toluene, Solvesso-100 (S-100), and Solvesso-150 (S-150). These can be used individually or in combination of two or more.

[0106] The solvent is added, for example, so that the solid content of the luminous pigment dispersion (X) is between 16% by mass and 20% by mass.

[0107] Other pigments The lustrous pigment dispersion (X) may contain other pigments besides the lustrous pigment, depending on its opacity and other properties. Examples of other pigments include rust-preventive pigments, coloring pigments, and extender pigments. Examples of coloring pigments include those similar to those exemplified as coloring pigments used in colored coatings. Examples of extender pigments include calcium carbonate, barium sulfate, clay, and talc. These may be used individually or in combination of two or more.

[0108] • Additives The luminous pigment dispersion (X) may contain various additives as needed. Examples of additives include UV absorbers, antioxidants, defoamers, viscosity modifiers, anti-settling agents, dispersants, surface modifiers, and pinhole inhibitors. These may be used individually or in combination of two or more.

[0109] (2) Step of forming an uncured colored coating film An uncured glossy coating is painted with a colored paint (Y) to form an uncured colored coating.

[0110] The colored paint (Y) is applied, for example, so that the thickness of the colored film after curing is between 5 μm and 15 μm.

[0111] As for the coating method, for example, a method similar to the coating method for the lustrous pigment dispersion (X) can be used. Among these, rotary atomizing electrostatic coating is preferred from the viewpoint of coating efficiency.

[0112] After applying the colored paint (Y), pre-drying (also called preheating) may be performed. This suppresses the boiling of the solvent contained in the colored paint film during the curing process, making it easier to suppress the occurrence of bubbling. The conditions for pre-drying are not particularly limited and may be the same as those for pre-drying the lustrous pigment dispersion (X).

[0113] (Colored paint (Y)) The colored coating is formed by a colored paint (Y). The colored paint (Y) may be water-based or solvent-based. The colored paint (Y) may be a one-component paint or a multi-component paint such as a two-component paint.

[0114] The colored paint (Y) contains the above-mentioned coloring pigment. The colored paint (Y) also contains resin components and solvents as needed. The colored paint (Y) is prepared by diluting a mixture of coloring pigments, resin components, and various additives with a solvent.

[0115] The viscosity of the colored paint (Y), as measured by a Type B viscometer at 20°C, may be, for example, 500 cps / 6 rpm or more and 6000 cps / 6 rpm or less.

[0116] The solid content of the colored paint (Y) may be 10% by mass or more and 40% by mass or less. The solid content of the colored paint (Y) is the total components of the colored paint (Y) excluding the solvent.

[0117] The PWC of the coloring pigment may be, for example, 50% by mass or less and 0.1% by mass or more. The PWC of the coloring pigment may be 20% by mass or less.

[0118] • Resin components The colored paint (Y) may contain a resin component. Examples of resin components include those similar to those exemplified as the resin component of the lustrous pigment dispersion (X) (typically, thermosetting resins and curing agents).

[0119] The resin component content may be, for example, 50% by mass or more and 95% by mass or less of the total solid content of the colored paint (Y). The above resin component content may be 60% by mass or more, and may be 65% by mass or more. The above resin component content may be 90% by mass or less, and may be 85% by mass or less.

[0120] ·solvent The solvent may be water (deionized water), an organic solvent, or a combination thereof. Among these, from the perspective of low VOC, it may be water. That is, the colored paint (Y) may be water-based. In the water-based colored paint (Y), the proportion of water in the solvent is 50% by mass or more, and may be 80% by mass or more. Examples of the organic solvent include the same ones as those exemplified as the organic solvent of the bright pigment dispersion (X).

[0121] · Other pigments The colored paint (Y) may further contain other pigments according to hiding power and the like. Examples of other pigments include, for example, rust preventive pigments and the above-mentioned extender pigments. These are used alone or in combination of two or more.

[0122] · Additives The colored paint (Y) may contain various additives as necessary. Examples of the additives include the same ones as those exemplified as the additives of the bright pigment dispersion (X).

[0123] (Step of forming an uncured clear coating film) A clear paint (Z) is applied on the uncured colored coating film to form an uncured clear coating film.

[0124] Examples of the coating method include the same methods as those for coating the colored paint. Among these, from the perspective of coating efficiency, rotary atomization electrostatic coating is preferable.

[0125] The clear paint (Z) is applied, for example, so that the thickness of the clear coating film after curing is 25 μm or more and 45 μm or less.

[0126] (Clear paint (Z)) The clear coating film is formed by the clear paint (Z). The clear paint (Z) may be a powder, water-based, or solvent-based. The clear paint (Z) may be a one-component paint or a multi-component paint such as a two-component paint. In terms of being easily improved in the physical properties of the coating film, the clear paint (Z) may be a two-component type.

[0127] Clear coating (Z) contains a resin component. Clear coating (Z) contains a solvent as needed. Clear coating (Z) is prepared by diluting a mixture of resin components and various additives with a solvent.

[0128] The viscosity of the clear coating (Z), as measured by a Type B viscometer at 20°C, may be, for example, between 500 cps / 6 rpm and 6000 cps / 6 rpm.

[0129] The solid content of the clear coating (Z) may be, for example, 40% by mass or more and 60% by mass or less. The solid content of the clear coating (Z) is the total components of the clear coating (Z) excluding the solvent.

[0130] • Resin components The clear coating (Z) contains a resin component. Examples of the resin component include those similar to those exemplified as the resin component of the luminous pigment dispersion (X). The clear coating (Z) may contain a thermosetting resin and a curing agent as its resin component. Such a clear coating (Z) is a so-called two-component coating.

[0131] The two-component clear coating (Z) may contain a hydroxyl group-containing resin as a thermosetting resin and a polyisocyanate compound as a curing agent, as this facilitates the improvement of the physical properties of the coating film.

[0132] Examples of hydroxyl group-containing resins include hydroxyl group-containing acrylic resins, hydroxyl group-containing polyester resins, hydroxyl group-containing polyether resins, and hydroxyl group-containing polyurethane resins. These can be used individually or in combination of two or more. In particular, hydroxyl group-containing acrylic resins and hydroxyl group-containing polyester resins are preferred, and hydroxyl group-containing acrylic resins are also preferred.

[0133] The hydroxyl value of the hydroxyl-containing acrylic resin may be, for example, 80 mg KOH / g or more and 200 mg KOH / g or less. This can improve the scratch resistance and water resistance of the resulting coating film. The hydroxyl value of the hydroxyl-containing acrylic resin may be 100 mg KOH / g or more. The hydroxyl value of the hydroxyl-containing acrylic resin may be 180 mg KOH / g or less.

[0134] The weight-average molecular weight of the hydroxyl group-containing acrylic resin may be between 2,500 and 40,000. This can improve the acid resistance and smoothness of the resulting coating film. The weight-average molecular weight of the hydroxyl group-containing acrylic resin may be 5,000 or more. The weight-average molecular weight of the hydroxyl group-containing acrylic resin may be 30,000 or less.

[0135] The weight-average molecular weight can be calculated from the chromatogram measured by gel permeation chromatography, using the molecular weight of standard polystyrene as a reference. For example, the HLC8120GPC (manufactured by Tosoh Corporation) is used as the gel permeation chromatograph. For the column, TSKgel G-4000HXL, TSKgel G-3000HXL, TSKgel G-2500HXL, and TSKgel G-2000HXL (all manufactured by Tosoh Corporation) are used. Chromatography is performed, for example, using tetrahydrofuran as the mobile phase and a differential refractive index detector (RI) as the detector, under conditions of a measurement temperature of 40°C and a flow rate of 1 cc / min.

[0136] Polyisocyanate compounds have at least two isocyanate groups in one molecule. Examples of polyisocyanate compounds include aliphatic polyisocyanates, alicyclic polyisocyanates, aliphatic polyisocyanates having aromatic rings not bonded to isocyanate groups in the molecule (aroliphatic polyisocyanates), aromatic polyisocyanates, and derivatives of these polyisocyanates. These can be used individually or in combination of two or more.

[0137] Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer diisocyanate, and methyl 2,6-diisocyanatohexanoate (common name: lig Aliphatic diisocyanates such as diisocyanates (2,6-diisocyanatohexanoate 2-isocyanatoethyl, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, and 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyloctane are examples of aliphatic triisocyanates.

[0138] Examples of alicyclic polyisocyanates include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 4-methyl-1,3-cyclohexylene diisocyanate (common name: hydrogenated TDI), 2-methyl-1,3-cyclohexylene diisocyanate, 1,3- Alternatively, alicyclic diisocyanates such as 1,4-bis(isocyanatomethyl)cyclohexane (common name: hydrogenated xylylene diisocyanate) or mixtures thereof, methylenebis(4,1-cyclohexanediyl) diisocyanate (common name: hydrogenated MDI), norbornane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate); 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2- (3-Isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 2-(3-Isocyanatopropyl)-2,6-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 3-(3-Isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 5-(2-Isocyanatoethyl)-2-isocyanatomethyl-3-(3-Isocyanatopropyl)-bicyclo(2.2.1)heptane Examples include alicyclic triisocyanates such as 6-(2-isocyanatoethyl)-2-isocyanatomethyl-3-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, and 6-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane.

[0139] Examples of aromatic aliphatic polyisocyanates include aromatic aliphatic diisocyanates such as methylenebis(4,1-phenylene) diisocyanate (common name: MDI), 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene (common name: tetramethylxylylene diisocyanate) or mixtures thereof; and aromatic aliphatic triisocyanates such as 1,3,5-triisocyanatomethylbenzene.

[0140] Examples of aromatic polyisocyanates include aromatic diisocyanates such as m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylenediisocyanate, 1,5-naphthalenediisocyanate, 2,4-tolylenediisocyanate (common name: 2,4-TDI) or 2,6-tolylenediisocyanate (common name: 2,6-TDI) or mixtures thereof, 4,4'-toluidinediisocyanate, and 4,4'-diphenyletherdiisocyanate; aromatic triisocyanates such as triphenylmethane-4,4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, and 2,4,6-triisocyanatotoluene; and aromatic tetraisocyanates such as 4,4'-diphenylmethane-2,2',5,5'-tetraisocyanate.

[0141] Examples of polyisocyanate derivatives include the polyisocyanate dimers, trimers, biuretes, allophanates, uretodiones, uretoimines, isocyanurates, oxadiazinetriones, polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI), and crude TDI.

[0142] From the viewpoint of adhesion and compatibility, the material may be hexamethylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), or a derivative of hexamethylene diisocyanate.

[0143] As the polyisocyanate compound, a prepolymer of the above-mentioned polyisocyanate or its derivative may be used. The prepolymer is obtained by reacting the polyisocyanate or its derivative with a compound that can react with it under conditions of isocyanate group excess. The compound that can react with the polyisocyanate or its derivative is a compound having an active hydrogen group such as a hydroxyl group or an amino group. Examples of the above-mentioned compound include polyhydric alcohols, low molecular weight polyester resins, amines, and water.

[0144] Blocked polyisocyanate compounds may be used as the polyisocyanate compound. Blocked polyisocyanate compounds are obtained by blocking the isocyanate groups in the above-mentioned polyisocyanate or its derivatives with a blocking agent.

[0145] Examples of blocking agents include phenol compounds, lactam compounds, alcohols, ethers, oxime compounds, compounds having an active methylene group, mercaptan compounds, acid amide compounds, imide compounds, amine compounds, imidazole compounds, urea compounds, carbamate esters, imine compounds, sulfites, azole compounds, and ketone compounds.

[0146] The equivalent ratio (=OH / NCO) of the hydroxyl groups in the hydroxyl group-containing resin to the isocyanate groups in the polyisocyanate compound may be between 0.5 and 2.0 from the viewpoint of the curability and scratch resistance of the coating film. The above equivalent ratio (=OH / NCO) may be 0.8 or higher. The above equivalent ratio (=OH / NCO) may be 1.5 or lower.

[0147] ·solvent The solvent may be water (deionized water), an organic solvent, or a combination thereof. In particular, from the viewpoint of low VOC content, water may be used. That is, the clear coating (Z) may be water-based. In water-based clear coatings (Z), the proportion of water in the solvent is 50% by mass or more, and may be 80% by mass or more. Examples of organic solvents include those similar to those exemplified as organic solvents for the luminous pigment dispersion (X).

[0148] Pigments The clear coating (Z) may contain pigments to the extent that transparency is not impaired. Examples of pigments include the above-mentioned luminous pigments, coloring pigments, and extender pigments. These may be used individually or in combination of two or more. The amount of pigment added is not particularly limited. The PWC of the pigment may be, for example, 30% by mass or less, or 10% by mass or less. The PWC of the pigment may be, for example, 0.01% by mass or more.

[0149] • Additives The clear coating (Z) may contain various additives as needed. Examples of additives include those similar to those exemplified for the luminous pigment dispersion (X).

[0150] (4) Curing process This method simultaneously cures an uncured glossy coating, an uncured colored coating, and an uncured clear coating. Each coating can be cured by heating.

[0151] The heating conditions are set appropriately according to the composition of each coating film. The heating temperature is, for example, 70°C to 150°C, or 80°C to 140°C. The heating time is, for example, 10 minutes to 40 minutes, or 20 minutes to 30 minutes. Examples of heating devices include drying furnaces such as hot air furnaces, electric furnaces, and infrared induction heating furnaces. [Examples]

[0152] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples. Note that "parts" and "%" are all based on mass.

[0153] [Example 1] (I) Preparation of the object to be coated A zinc phosphate treated steel sheet with a cured electrodeposited coating was prepared as the substrate. The cured electrodeposited coating was formed by electrodepositing "Powernics," a cationic electrodeposition coating composition manufactured by Nippon Paint Co., Ltd., onto the zinc phosphate treated steel sheet to a dry film thickness of 20 μm, and then heating it at 160°C for 30 minutes.

[0154] (II) Preparation of paint Preparation of the luminous pigment dispersion (X) A lustrous pigment dispersion (X) was obtained by adding deionized water to 0.86 parts of flaky aluminum (Al) particles A, 0.09 parts of flaky Al particles B, 0.03 parts of vapor-deposited chromium oxide, 13.7 parts of aluminum dissolving thinner, 0.99 parts of carbon black pigment, 1.04 parts of perylene pigment, 0.09 parts of iron oxide pigment, 3.50 parts of hydroxyl group-containing acrylic emulsion resin, 3.50 parts of thermosetting resin, 0.24 parts of phosphoric acid, 0.33 parts of surface modifier, 0.37 parts of amine, and 0.03 parts of defoamer so that the solid content was 18.0% and stirring.

[0155] Scale-like Al particles A: Product name "Z0684N", manufactured by Toyo Aluminum Co., Ltd., thickness 0.15 μm, average particle size 12 μm Scale-like Al particles B: Product name "FD-5090", manufactured by Asahi Kasei Corporation, thickness 0.11 μm, average particle size 9 μm Vapor-deposited chromium oxide: Product name "METALURE Liquid Black", manufactured by Eckart, thickness 0.015~0.2 μm, average particle size 14 μm

[0156] • Preparation of colored paint (Y) 1.01 parts perylene pigment, 0.27 parts iron oxide pigment, 7.57 parts hydroxyl group-containing acrylic emulsion resin, 1.71 parts acrylic resin, 4.81 parts thermosetting resin, 0.26 parts surface modifier, 0.47 parts amine, and 0.01 parts deionized water was added to the mixture to a total volume of 100 parts and stirred to obtain a colored paint (Y) with a solid content of 23.0%.

[0157] (Manufacturing of hydroxyl group-containing acrylic resin emulsion) In a standard reaction vessel for the production of acrylic resin emulsions, equipped with a stirrer, thermometer, dropping funnel, reflux condenser, and nitrogen inlet tube, 445 parts water and 5 parts Newcol 293 (manufactured by Nippon Emulsifier Co., Ltd.) were charged, and the mixture was heated to 75°C while stirring. A monomer mixture containing 145 parts methyl methacrylate, 50 parts styrene, 220 parts ethyl acrylate, 70 parts 2-hydroxyethyl methacrylate, and 15 parts methacrylic acid, along with 240 parts water and 30 parts Newcol 293 (manufactured by Nippon Emulsifier Co., Ltd.), was emulsified using a homogenizer to obtain a monomer pre-emulsification solution. The monomer pre-emulsification solution was added dropwise over 3 hours while stirring in the reaction vessel. In parallel with the addition of the monomer pre-emulsification solution, an aqueous solution of 1 part APS (ammonium persulfate) dissolved in 50 parts water was added dropwise to the reaction vessel as a polymerization initiator, evenly until the addition of the monomer pre-emulsification solution was complete. After the dropwise addition of the monomer pre-emulsifier was complete, the reaction was continued at 80°C for another hour. After the reaction mixture was cooled, an aqueous solution of 2 parts dimethylaminoethanol dissolved in 20 parts water was added to the reaction vessel to obtain a hydroxyl group-containing acrylic resin emulsion with a solid content of 40.6% by mass.

[0158] The obtained hydroxyl group-containing acrylic resin emulsion had an acid value of 20 mg KOH / g, a hydroxyl value of 60 mg KOH / g, and a glass transition temperature (Tg) of 30°C. The solid content was measured according to the JIS K 5601-1-2 method for measuring residual content after heating.

[0159] • Preparation of clear coating (Z) As the clear coating (Z), PU Excel O-3100-6 (manufactured by Nippon Paint Co., Ltd., a two-component clear coating containing a hydroxyl group-containing resin and a polyisocyanate compound) was prepared.

[0160] (III) Process for forming an uncured glossy coating film A luminous pigment dispersion (X) was applied to a substrate having an electrodeposited coating using Metabel.

[0161] (IV) Process for forming an uncured colored coating film A colored paint (Y) was applied to an uncured glossy coating using Metabel.

[0162] (V) Process for forming an uncured clear coating Clear paint (Z) was applied to the uncured colored coating using a micromicrobel.

[0163] (VI) Curing process After the clear coating formation step (V), the substrate was heated at 140°C for 20 minutes to obtain a substrate with a multilayer coating A1. In the multilayer coating A1, the thickness of the glossy coating was 5 μm, the thickness of the colored coating was 10 μm, and the thickness of the clear coating was 30 μm.

[0164] [Comparative Example 1] A coated article having a multilayer coating B1 was obtained in the same manner as in Example 1, except that a luminous pigment dispersion (x1) prepared as described below was used.

[0165] • Preparation of the luminous pigment dispersion (x1) A lustrous pigment dispersion (x1) was obtained by adding deionized water to 0.95 parts of flake-shaped Al particles C, 0.03 parts of vapor-deposited chromium oxide, 13.7 parts of aluminum dissolving thinner, 0.99 parts of carbon black pigment, 1.04 parts of perylene pigment, 0.09 parts of iron oxide pigment, 3.50 parts of hydroxyl group-containing acrylic emulsion resin, 3.50 parts of thermosetting resin, 0.24 parts of phosphoric acid, 0.33 parts of surface modifier, 0.37 parts of amine, and 0.03 parts of defoamer so that the solid content was 18% and stirring.

[0166] Scale-like Al particles C: Product name "WM-2068", manufactured by Asahi Kasei Corporation, thickness 0.15 μm, average particle size 16 μm

[0167] [Comparative Example 2] A coated article having a multilayer coating B2 was obtained in the same manner as in Example 1, except that a lustrous pigment dispersion (x2) prepared as described below was used.

[0168] • Preparation of the luminous pigment dispersion (x2) A lustrous pigment dispersion (x2) was obtained by adding deionized water to 0.95 parts of flake-shaped Al particles D, 0.03 parts of vapor-deposited chromium oxide, 13.7 parts of aluminum dissolving thinner, 0.99 parts of carbon black pigment, 1.04 parts of perylene pigment, 0.09 parts of iron oxide pigment, 3.50 parts of hydroxyl group-containing acrylic emulsion resin, 3.50 parts of thermosetting resin, 0.24 parts of phosphoric acid, 0.33 parts of surface modifier, 0.37 parts of amine, and 0.03 parts of defoamer so that the solid content was 18% and stirring.

[0169] Flake-shaped Al particles D: Product name "TCR-3080", manufactured by Toyo Aluminum Co., Ltd., thickness 0.33 μm, average particle size 13 μm

[0170] [Comparative Example 3] A coated article having a multilayer coating B3 was obtained in the same manner as in Example 1, except that the thickness of the glossy coating film was set to 2 μm.

[0171] [Comparative Example 4] A coated article having a multilayer coating B4 was obtained in the same manner as in Example 1, except that the thickness of the glossy coating film was set to 10 μm.

[0172] [Comparative Example 5] A coated article having a multilayer coating B5 was obtained in the same manner as in Example 1, except that the solid content of the lustrous pigment dispersion was adjusted to 15.0%.

[0173] [Comparative Example 6] A coated article having a multilayer coating B6 was obtained in the same manner as in Example 1, except that the solid content of the lustrous pigment dispersion was adjusted to 25.0%.

[0174] [evaluation] The following evaluations were performed on the obtained multi-layer coating or glossy coating. The evaluation results are shown in Table 1.

[0175] (1) Thickness of the glossy coating The thickness of the cured glossy coating was measured using an electromagnetic film thickness gauge (FISCHERSCOPE® MMS PC2, manufactured by Fischer Instruments, Inc.). The average of five different samples was used as the thickness of the glossy coating. The thickness of other coatings was measured in the same manner.

[0176] (2) Lightness L * 15 , brightness L * 110 A painted article with a multi-layer coating was used as the test panel. Using a variable-angle colorimeter (Gonio-Spectrophotometer GSP-1, manufactured by Murakami Color Materials Research Institute Co., Ltd.), light I was shone from the clear coating side onto the multi-layer coating at a 45-degree angle. 45 When the light is received at angles of 15 degrees and 110 degrees relative to the specularly reflected light, L * C * Lightness L in the h color system * 15 and brightness L * 110 The average value of five different samples was obtained, and the brightness L * 15 and brightness L * 110 The brightness L of Example 1 was determined as follows. * 15 It is 20.0, and the brightness L * 110 The value was 2.9.

[0177] (3) Saturation C * 15 , saturation C * 110 (2) Similarly, L * C * Saturation C in the h color system * 15 and saturation C* 110 The average of five different samples was obtained, and the saturation C * 15 and saturation C * 110 This was the case. Saturation C of Example 1 * 15 It is 44.1, and the saturation C * 110 The value was 4.6.

[0178] (4) Brightness GL * 15 , brightness GL * 110 A test plate was prepared by coating a substrate with a glossy pigment dispersion and heating it at 140°C for 20 minutes. The L of the glossy coating was determined in the same manner as in (2), except that the surface of the obtained glossy coating was irradiated with light at a 45-degree angle. * C * Lightness GL in the h color system * 15 and brightness GL * 110 The average value of five different samples was used for the lightness GL. * 15 and brightness GL * 110 The brightness GL of Example 1 was determined as follows. * 15 It is 46.4, and the lightness GL * 110 The value was 2.3.

[0179] (5) Saturation GC * 15 , GC * 110 (4) Similarly, L * C * saturation GC in the h color system * 15 and saturation GC * 110 The average of five different samples was obtained for saturation GC. * 15 and saturation GC * 110 This was the case. Chromatic GC of Example 1 *15 It is 23.4, and the saturation GC * 110 The value was 1.0.

[0180] (6) Particle-like Si 15 value By using a multi-angle colorimeter (BYK-mac i, manufactured by BYK-Gardner), light irradiated from a direction tilted 15 degrees relative to the normal direction of the multi-layer coating film is imaged and analyzed from the normal direction of the multi-layer coating film, thereby enabling particle sensitivity Si 15 The average value of five different samples was obtained, and the particle sensitivity Si 15 That's what I decided.

[0181] (7) Opacity of the glossy coating An opacity test paper conforming to JIS K 5600-4-1(b) (manufactured by Nippon Test Panel Co., Ltd.) was used. A glossy pigment dispersion was spray-coated onto the 2 x 2 cm black and white checkerboard pattern on the opacity test paper so that a gradient of dry film thickness was created, and then heat-cured. Next, the area of ​​the coating film where the black and white checkerboard pattern was no longer visible was determined by visual inspection, and the film thickness at that area was measured. The measured film thickness was defined as the black and white opacity film thickness. The opacity of the glossy coating film was evaluated based on the obtained black and white opacity film thickness according to the evaluation criteria below.

[0182] (Evaluation Criteria) Good: Black and white opacity film thickness is 6 μm or less. Defect: Black and white opacity film thickness exceeds 6 μm

[0183] (8)Light transmittance A luminous pigment dispersion was applied to a release substrate and heated at 140°C for 20 minutes. The formed coating was then peeled off the substrate to obtain a film. This film was irradiated with light at wavelengths of 400-700 nm using a spectrophotometer (Hitachi U-3310), and the light transmittance was measured at 10 nm intervals.

[0184] (Evaluation Criteria) Good: Light transmittance is 0.25% or less at all wavelengths. Defective: Light transmittance exceeds 0.25% at any wavelength.

[0185] [Table 1]

[0186] This disclosure includes the following aspects. [1] A painted article comprising a workpiece and a multi-layer coating, The aforementioned multi-layer coating film is A glossy coating film is formed on the aforementioned object to be coated, and contains a glossy pigment. A colored coating film containing a coloring pigment is formed on the aforementioned glossy coating film, The system comprises a clear coating formed on the aforementioned colored coating, Light I was irradiated onto the surface of the multilayer coating film at a 45-degree angle. 45 The brightness L is based on the spectral reflectance obtained by receiving light at a 15-degree angle to specularly reflected light. * 15 And, the aforementioned light I 45 The brightness L is based on the spectral reflectance obtained by receiving light at an angle of 110 degrees to specularly reflected light. * 110 Ratio (L * 15 / L * 110 ) is between 5 and 9, The aforementioned optical I 45 Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L * C * Saturation C in the h color system * 15 And, the aforementioned light I 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to the specularly reflected light, L * C * Saturation C in the h color system * 110 The ratio (C * 15 / C * 110 Painted articles in which the ratio is between 8 and 12. [2] The surface of the aforementioned glossy coating was irradiated with light GI at a 45-degree angle. 45The brightness GL is based on spectral reflectance when light is received at an angle of 15 degrees to specularly reflected light. * 15 And the aforementioned optical GI 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to specularly reflected light, and is expressed as brightness GL. * 110 Ratio to (GL) * 15 / GL * 110 ) is between 15 and 25, The aforementioned optical GI 45 Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L * C * saturation GC in the h color system * 15 And the aforementioned optical GI 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to the specularly reflected light, L * C * saturation GC in the h color system * 110 Ratio to (GC) * 15 / GC * 110 The painted articles described in [1] above, wherein the ratio is between 15 and 35. [3] The coated article according to [1] or [2] above, wherein the thickness of the glossy coating is 3 μm or more and 7 μm or less. [4] The glossy pigment is any of the coated articles [1] to [3] described above, comprising flaky aluminum particles. [5] The flaky aluminum particles have an average particle diameter of 8 μm or more and 13 μm or less, and a thickness of 0.08 μm or more and 0.2 μm or less, as described in the above [4] painted article. [6] The aforementioned glossy pigment comprises vapor-deposited chromium oxide, and is one of the coated articles described in [1] to [5] above. [7] A step of applying a glossy pigment dispersion containing a glossy pigment onto a substrate to form an uncured glossy coating film, The process involves applying a colored paint containing a coloring pigment onto the uncured glossy coating to form an uncured colored coating, The process involves applying a clear coating to the uncured colored coating to form an uncured clear coating, The process includes a step of curing the uncured glossy coating film, the uncured colored coating film, and the uncured clear coating film to obtain a multi-layer coating film, Light I was irradiated onto the surface of the multilayer coating film at a 45-degree angle. 45 The brightness L is based on the spectral reflectance obtained by receiving light at a 15-degree angle to specularly reflected light. * 15 And, the aforementioned light I 45 The brightness L is based on the spectral reflectance obtained by receiving light at an angle of 110 degrees to specularly reflected light. * 110 Ratio to (L * 15 / L * 110 ) is between 5 and 9, The aforementioned optical I 45 Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L * C * Saturation C in the h color system * 15 And, the aforementioned light I 45 This is based on the spectral reflectance of light received at an angle of 110 degrees to the specularly reflected light, L * C * Saturation C in the h color system * 110 The ratio (C * 15 / C * 110 A method for manufacturing painted articles, wherein the ratio is 8 or more and 12 or less. [8] The method for manufacturing the coated article according to [7], wherein the solid content of the lustrous pigment dispersion is 16% by mass or more and 20% by mass or less. [9] A method for manufacturing the painted article according to [7] or [8], wherein the clear coating is a two-component coating comprising a hydroxyl group-containing resin and a polyisocyanate compound. [Industrial applicability]

[0187] The painted articles of the present invention are particularly suitable as exterior panels for automobile bodies.

Claims

1. A painted article comprising a workpiece and a multi-layer coating, The aforementioned multi-layer coating film is A glossy coating film is formed on the aforementioned object to be coated, and contains a glossy pigment. A colored coating film containing a coloring pigment is formed on the aforementioned glossy coating film, The system comprises a clear coating formed on the aforementioned colored coating, The light I irradiated at an angle of 45 degrees with respect to the surface of the multilayer coating film ４５ is the lightness L based on the spectral reflectance received at an angle of 15 degrees with respect to the specularly reflected light ＊ １５ and the light I ４５ is the lightness L based on the spectral reflectance received at an angle of 110 degrees with respect to the specularly reflected light ＊ １１０ and the ratio (L ＊ １５ / L ＊ １１０ ) is 5 or more and 9 or less The aforementioned optical I ４５ Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L ＊ C ＊ Saturation C in the h color system ＊ １５ And, the aforementioned light I ４５ Based on the spectral reflectance of light received at an angle of 110 degrees to specularly reflected light, L ＊ C ＊ Saturation C in the h color system ＊ １１０ The ratio (C ＊ １５ / C ＊ １１０ A painted article in which the ratio is between 8 and 12.

2. The surface of the aforementioned glossy coating film was irradiated with light GI at a 45-degree angle. ４５ The brightness GL is based on the spectral reflectance obtained by receiving light at a 15-degree angle to specularly reflected light. ＊ １５ And the aforementioned optical GI ４５ The brightness GL is based on the spectral reflectance of light received at an angle of 110 degrees to specularly reflected light. ＊ １１０ Ratio to (GL ＊ １５ / GL ＊ １１０ ) is between 15 and 25, The aforementioned optical GI ４５ Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L ＊ C ＊ saturation GC in the h color system ＊ １５ And the aforementioned optical GI ４５ Based on the spectral reflectance of light received at an angle of 110 degrees to specularly reflected light, L ＊ C ＊ saturation GC in the h color system ＊ １１０ Ratio to (GC ＊ １５ / GC ＊ １１０ The painted article according to claim 1, wherein the coefficient of gravity is 15 or more and 35 or less.

3. The coated article according to claim 1 or 2, wherein the thickness of the glossy coating film is 3 μm or more and 7 μm or less.

4. The coated article according to claim 1 or 2, wherein the lustrous pigment comprises flaky aluminum particles.

5. The coated article according to claim 4, wherein the flake-like aluminum particles have an average particle diameter of 8 μm or more and 13 μm or less, and a thickness of 0.08 μm or more and 0.2 μm or less.

6. The coated article according to claim 1 or 2, wherein the luminous pigment comprises vapor-deposited chromium oxide.

7. The painted article according to claim 1 or 2, wherein the black and white opacity film thickness of the glossy coating film, as measured using opacity test paper in accordance with JIS K 5600-4-1(b), is 9 μm or less.

8. The painted article according to claim 1 or 2, wherein the transmittance of light with a wavelength of 400 to 700 nm of the glossy coating film is 0.25% or less.

9. A step of applying a glossy pigment dispersion containing a glossy pigment onto a substrate to form an uncured glossy coating film, The process involves applying a colored paint containing a coloring pigment onto the uncured glossy coating to form an uncured colored coating, The process involves applying a clear coating to the uncured colored coating to form an uncured clear coating, The process includes a step of curing the uncured glossy coating film, the uncured colored coating film, and the uncured clear coating film to obtain a multi-layer coating film, Light I was irradiated onto the surface of the multilayer coating film at a 45-degree angle. ４５ The brightness L is based on the spectral reflectance obtained by receiving light at a 15-degree angle to specularly reflected light. ＊ １５ And, the aforementioned light I ４５ The brightness L is based on the spectral reflectance obtained by receiving light at an angle of 110 degrees to specularly reflected light. ＊ １１０ Ratio to (L) ＊ １５ / L ＊ １１０ ) is between 5 and 9, The aforementioned optical I 4５ Based on the spectral reflectance of light received at an angle of 15 degrees to specularly reflected light, L ＊ C ＊ Saturation C in the h color system ＊ １５ And, the aforementioned light I ４５ Based on the spectral reflectance of light received at an angle of 110 degrees to specularly reflected light, L ＊ C ＊ Saturation C in the h color system ＊ １１０ The ratio (C ＊ １５ / C ＊ １１０ A method for manufacturing a painted article, wherein the ratio is 8 or more and 12 or less.

10. The method for manufacturing a coated article according to claim 9, wherein the solid content of the lustrous pigment dispersion is 16% by mass or more and 20% by mass or less.

11. The method for manufacturing a painted article according to claim 9 or 10, wherein the clear coating is a two-component coating comprising a hydroxyl group-containing resin and a polyisocyanate compound.

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