JP7587945B2 - Red multi-layer coating and vehicle - Google Patents

Description

The present invention relates to a red multi-layer coating film and a vehicle.

Multiple coatings with different functions are formed in sequence on the surface of an object to be coated, such as an automobile body, to protect the object while at the same time providing it with excellent design.

For example, a common method for forming such multiple coatings on an automobile body is to form an undercoat coating such as an electrocoating coating on the substrate, and then form an intermediate coating and a topcoat coating on top of that in sequence (see, for example, Patent Document 1). Of these coatings, it is the topcoat coating that has the greatest influence on the design of the coating, and the topcoat coating is made up of a base coating and a clear coating.

Furthermore, base coating films can be broadly divided into so-called metallic coating films and solid coating films. Generally, metallic coating films are coating films that contain scaly pigments (e.g., aluminum flakes) that have a lustrous appearance, and solid coating films are coating films that do not contain scaly pigments.

JP 2020-099888 A

In addition to metallic paint films, one method to improve the design of automobiles is to use colors with high value (brightness of color) and high saturation (vividness of color).

Red cars are produced in large numbers, and red is one of the many colors available for car paint, so red is one of the major colors.

However, in a single layer of red paint, there is generally a trade-off between lightness and saturation, so if you increase the amount of white pigment to increase the lightness of the paint, the saturation of the paint will decrease, and if you increase the amount of red pigment to increase the saturation of the paint, the lightness will decrease.

The inventors believed that if a solid coating could achieve both high brightness and high saturation, the range of color expression could be greatly expanded, and the design of automobiles could be further improved.

Therefore, the present invention aims to provide a red coating film that has high brightness and high saturation.

Another object of the present invention is to provide a vehicle having a red-colored paint film with high brightness and high saturation.

The red-based multi-layer coating film according to the present invention is
In order,
A white coating film having an L ^* value of 80 or more;
a first base coat having a hue of 1YR to 10Y on the Munsell Color System;
a second base coat having a hue of 1R to 10R on the Munsell Color System;
A red-based multi-layer coating film having a clear coating film,
A reddish multilayer coating film, in which a value SS obtained by multiplying the spectral reflectance of the reddish multilayer coating film by the photopic spectral luminous efficiency is 5% or less at a wavelength of 580 nm, and has a maximum value of 15% or more at wavelengths of 590 nm to 650 nm on the curve (wherein the spectral reflectance is the spectral reflectance of light received at a receiving angle of 45° with respect to light irradiated at an incident angle of 45° with respect to the normal to the reddish multilayer coating film on the clear coating film side of the reddish multilayer coating film). This allows the reddish multilayer coating film to have high brightness and high saturation.

In one embodiment of the red multilayer coating film according to the present invention, the curve has a maximum value within the range of 1.5 to 5% at wavelengths of 500 nm to 570 nm.

The vehicle according to the present invention has a red-based multi-layer coating film, with the clear coating film side located on the outside. This gives the vehicle high brightness and high saturation.

According to the present invention, it is possible to provide a reddish paint film having high brightness and high saturation. According to the present invention, it is possible to provide a vehicle having a reddish paint film having high brightness and high saturation.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a red multilayer coating film of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the configuration of the red multilayer coating film of the present invention. FIG. 3 is a schematic diagram showing an example of a method for measuring the spectral reflectance.

The following describes embodiments of the present invention. These descriptions are intended to be illustrative of the present invention and are not intended to limit the present invention in any way.

In the present invention, two or more embodiments may be combined in any manner.

In the present invention, the L ^* value, a ^* value, b ^* value, and C ^* value are the CIE 1976 lightness index, CIELAB 1976 a ^* coordinate, CIELAB 1976 b ^* coordinate, and CIELAB 1976 ab chroma, respectively, defined in JIS Z 8781-4:2013. The larger the L ^* value, the higher the whiteness and lightness of the object to be measured, and the smaller the L ^* value, the higher the blackness of the object to be measured. The larger the negative value of the a ^* value, the higher the greenness of the object to be measured, and the larger the positive value, the higher the magenta of the object to be measured. The larger the negative value of the ^b* value, the higher the blueness of the object to be measured, and the larger the positive value, the higher the yellowness of the object to be measured. The ^C* value is an index representing saturation, and the larger the value, the more vivid the color of the object to be measured, and the smaller the value, the more achromatic the object to be measured.

In the present invention, the L ^* value, a ^* value, b ^* value and C ^* value of the reddish multi-layer coating film and the white coating film are measured by the method described in the Examples.

In the present invention, the spectral reflectance of the red multilayer coating film is measured by the method described in the examples.

In this invention, the thickness of each coating or layer is referred to as the "film thickness."

In this specification, numerical ranges are intended to include the upper and lower limits of the range unless otherwise specified. For example, 590-650 nm means 590 nm or more and 650 nm or less.

In the present invention, the paint and the paint composition can be used interchangeably.

The accompanying drawings are schematic diagrams intended to facilitate understanding of the present invention, and therefore the coatings and layers in the drawings are not drawn to scale.

In the present invention, terms such as first, second, etc. are used herein to describe various layers, but these layers are not limited by these terms. These terms are used only to distinguish one layer from another.

(Red multi-layer coating)
The red-based multi-layer coating film according to the present invention is
In order,
A white coating film having an L ^* value of 80 or more;
a first base coat having a hue of 1YR to 10Y on the Munsell Color System;
a second base coat having a hue of 1R to 10R on the Munsell Color System;
A red-based multi-layer coating film having a clear coating film,
A reddish multilayer coating film, in which a value at a wavelength of 580 nm in a curve obtained from a value SS obtained by multiplying the spectral reflectance of the reddish multilayer coating film by the photopic spectral luminous efficiency, is 5% or less, and which has a maximum value of 15% or more in the wavelength range of 590 nm to 650 nm on the curve (wherein the spectral reflectance is the spectral reflectance of light received at a light receiving angle of 45° with respect to light irradiated at an incident angle of 45° with respect to the normal to the reddish multilayer coating film on the clear coating film side of the reddish multilayer coating film).

Fig. 1 is a schematic cross-sectional view showing an example of the configuration of the reddish multi-layer coating film of the present invention. The reddish multi-layer coating film 1 of the example of Fig. 1 has, in order, a white coating film 10 having an L ^* value of 80 or more, a first base coating film 20 having a hue of 1YR to 10Y in the Munsell Color System, a second base coating film 30 having a hue of 1R to 10R in the Munsell Color System, and a clear coating film 40.

Below, the white-based coating film, the first base coating film, the second base coating film, and the clear coating film, which are essential components of the red-based multilayer coating film of the present invention, are illustrated. Hereinafter, the white-based coating film and the clear coating film of the red-based multilayer coating film of the present invention may be simply referred to as the "white-based coating film" and the "clear coating film", respectively.

White-based coating film The white-based coating film of the red-based multilayer coating film of the present invention is a white-based coating film having an L ^* value of 80 or more, and is an intermediate coating film. The white-based coating film of the red-based multilayer coating film of the present invention has the function of imparting brightness to the red-based multilayer coating film.

The "white" in white-based coating refers to N8.0 to N10.0 on the Japan Paint Color Sample.

The L ^* value of the white coating film is 80 or more, and if the L ^* value is less than 80, the high brightness and high chroma of the red multilayer coating film cannot be achieved at the same time. The L ^* value of the white coating film is, for example, 80 to 95. In one embodiment, the L ^* value of the white coating film is 80 or more, 81 or more, 82 or more, 83 or more, 84 or more, 85 or more, 86 or more, 87 or more, 89 or more, 90 or more, 91 or more, 92 or more, 93 or more, or 94 or more. In another embodiment, the L ^* value of the white coating film is 95 or less, 94 or less, 93 or less, 92 or less, 91 or less, 90 or less, 89 or less, 88 or less, 87 or less, 86 or less, 85 or less, 84 or less, 83 or less, 82 or less, or 81 or less.

White coatings contain white pigments and film-forming resins.

The white pigment is not particularly limited, and known white pigments such as titanium oxide, barium sulfate, and zinc oxide can be used. The white pigments may be used alone or in combination of two or more.

The amount of white pigment in the white coating film may be appropriately adjusted so that the L ^* value is 80 or more, and is, for example, 1 to 60 parts by mass per 100 parts by mass of the solid content of the coating film-forming resin of the white coating film.

The white-based coating film may contain known luster pigments such as scaly aluminum flake pigments, mica pigments, graphite pigments, and glass flake pigments, as long as the effects of the present invention are not impaired. When the white-based coating film contains a luster pigment, the content is, for example, 5 parts by mass or less, 4 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, 1 part by mass or less, 0.5 parts by mass or less, or 0.1 parts by mass or less, per 100 parts by mass of the solid content of the coating film-forming resin of the white-based coating film. In one embodiment, the white-based coating film does not contain a luster pigment.

The film-forming resin for the white coating film is not particularly limited, and any known film-forming resin for an undercoat coating film can be used. Examples of film-forming resins for the white coating film include acrylic resins, polyester resins, polyurethane resins, epoxy resins, fluororesins, silicone resins, and polyether resins. The film-forming resins may be used alone or in combination of two or more.

A white coating film only needs to contain a white pigment and a film-forming resin, and may also contain other ingredients such as pigments other than the white pigment, hardeners, dispersants, defoamers, and leveling agents.

Methods for making the L ^* value of the white coating film 80 or more include, for example, blending the above-mentioned white pigment in an amount of 1 to 60 parts by mass per 100 parts by mass of the solid content of the coating film-forming resin of the white coating film, and using a high refractive index pigment.

The thickness of the white coating film is not particularly limited and may be adjusted as appropriate, but is, for example, 5 to 50 μm, preferably 10 to 30 μm. In one embodiment, the thickness of the white coating film is 10 μm or more, 15 μm or more, 20 μm or more, or 25 μm or more. In another embodiment, the thickness of the white coating film is 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less.

The white-based coating film may be used alone or in combination of two or more types having different L ^* values, film thicknesses, etc. For example, the L ^* value of the white-based coating film may be 80 in one portion of the red-based multilayer coating film, and the L ^* value of the white-based coating film may be 85 in another portion of the red-based multilayer coating film.

First base coating film The first base coating film of the reddish multi-layer coating film of the present invention is a coating film having a hue of 1YR to 10Y in the Munsell color system, and is the first topcoat coating film. The first base coating film of the reddish multi-layer coating film of the present invention has the function of imparting brightness and chroma to the reddish multi-layer coating film.

The first base coating has one or more hues selected from the group consisting of 1YR to 10Y hues in the Munsell Color System (100 hues), that is, 1YR, 2YR, 3YR, 4YR, 5YR, 6YR, 7YR, 8YR, 9YR, 10YR, 1Y, 2Y, 3Y, 4Y, 5Y, 6Y, 7Y, 8Y, 9Y and 10Y. If the hue of the first base coating is redder (5R) than 1YR or greener (5GY) than 10Y, the lightness and saturation of the red-based multi-layer coating cannot be highly balanced. In a preferred embodiment, the hue of the first base coating is one or more hues selected from the group consisting of 6YR, 4Y, 5Y, 6Y, 7Y, 8Y, 9Y and 10Y, from the viewpoint of increasing visual sensitivity. In another preferred embodiment, the hue of the first base coating film is one or more selected from the group consisting of 4Y, 5Y, 6Y, 7Y, 8Y, 9Y, and 10Y. In yet another preferred embodiment, the hue of the first base coating film is one or more selected from the group consisting of 5Y, 6Y, 7Y, 8Y, 9Y, and 10Y. In yet another preferred embodiment, the hue of the first base coating film is one or more selected from the group consisting of 5Y and 10Y.

The first base coating contains a pigment and a film-forming resin.

The pigment for the first base coating film is not particularly limited as long as it is a pigment that can adjust the hue of the first base coating film to a hue range of 1YR to 10Y. For example, a known pigment such as Hoster Palm Yellow can be used as the pigment for the first base coating film. The pigment for the first base coating film may be used alone or in combination of two or more types.

The amount of pigment in the first base coating film may be adjusted as appropriate so that the hue of the first base coating film falls within the range of 1YR to 10Y, for example, 1 to 30 parts by mass per 100 parts by mass of the solid content of the coating film-forming resin of the first base coating film.

The first base coating film may contain the above-mentioned luster pigment to the extent that the effect of the present invention is not impaired. When the first base coating film contains a luster pigment, the content is, for example, 5 parts by mass or less, 4 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, 1 part by mass or less, 0.5 parts by mass or less, or 0.1 parts by mass or less per 100 parts by mass of the solid content of the coating film-forming resin of the first base coating film. In one embodiment, the first base coating film does not contain a luster pigment.

The film-forming resin for the first base coating film is not particularly limited, and any known film-forming resin for a topcoat coating film can be used. Examples of the film-forming resin for the first base coating film include the film-forming resins listed above for the white coating film. The film-forming resins may be used alone or in combination of two or more.

The first base coating contains a pigment and a coating film-forming resin, and as long as its hue falls within the hue range of 1YR to 10Y, it may contain other components such as pigments other than those mentioned above, hardeners, dispersants, defoamers, and leveling agents.

The thickness of the first base coating film is not particularly limited and may be adjusted as appropriate, for example, 2 to 30 μm, preferably 5 to 15 μm. By making the film thickness thicker than 5 μm, the brightness and chroma of the red-based multilayer coating film are likely to be highly increased. In addition, by making the film thickness thinner than 15 μm, the brightness of the red-based multilayer coating film can be maintained higher while increasing the chroma, making use of the brightness of the white coating film as the base. In one embodiment, the film thickness of the first base coating film is 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, or 14 μm or more. In another embodiment, the thickness of the first base coating is 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less.

The first base coating film may be used alone or in combination with two or more different types having different hues, film thicknesses, etc. For example, in one portion of the red-based multi-layer coating film, the hue of the first base coating film may be 5Y, and in another portion of the red-based multi-layer coating film, the hue of the first base coating film may be 10Y.

Second base coating film The second base coating film of the reddish multi-layer coating film of the present invention is a coating film having a hue of 1R to 10R in the Munsell color system, and is the second topcoat coating film. The second base coating film of the reddish multi-layer coating film of the present invention has the function of imparting chroma to the reddish multi-layer coating film.

The second base coating has one or more hues selected from the group consisting of 1R to 10R in the Munsell Color System (100 hues), i.e., 1R, 2R, 3R, 4R, 5R, 6R, 7R, 8R, 9R and 10R. If the hue of the second base coating is more purple than 1R or more orange than 10R, the lightness and chroma of the red-based multi-layer coating cannot be well balanced. From the viewpoint of improving both lightness and chroma, in a preferred embodiment, the hue of the second base coating is one or more hues selected from the group consisting of 3R, 4R, 5R, 6R and 7R.

The second base coating contains a pigment and a film-forming resin.

The pigment for the second base coating film is not particularly limited as long as it is a pigment that can adjust the hue of the second base coating film to a hue range of 1R to 10R. For example, a known pigment such as Irgazin DPP Red can be used as the pigment for the second base coating film. The pigment for the second base coating film may be used alone or in combination of two or more types.

The amount of pigment in the second base coating film may be adjusted appropriately so that the hue of the second base coating film falls within the range of 1R to 10R, for example, 1 to 30 parts by mass per 100 parts by mass of the solid content of the coating film-forming resin of the second base coating film.

The second base coating film may contain the above-mentioned luster pigment to the extent that the effect of the present invention is not impaired. When the second base coating film contains a luster pigment, the content is, for example, 5 parts by mass or less, 4 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, 1 part by mass or less, 0.5 parts by mass or less, or 0.1 parts by mass or less per 100 parts by mass of the solid content of the coating film-forming resin of the second base coating film. In one embodiment, the second base coating film does not contain a luster pigment.

The film-forming resin for the second base coating film is not particularly limited, and any known film-forming resin for a topcoat coating film can be used. Examples of the film-forming resin for the second base coating film include the film-forming resins listed above for the white coating film. The film-forming resins may be used alone or in combination of two or more.

The second base coating contains a pigment and a coating-forming resin, and as long as its hue falls within the hue range of 1R to 10R, it may contain other components such as pigments other than those mentioned above, hardeners, dispersants, defoamers, and leveling agents.

The thickness of the second base coating film is not particularly limited and may be adjusted as appropriate, but may be, for example, 2 to 30 μm, preferably 5 to 15 μm. By setting the thickness to 5 to 15 μm, the brightness and saturation of the red multilayer coating film can be more highly balanced. In one embodiment, the thickness of the second base coating film is 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, or 14 μm or more. In another embodiment, the thickness of the second base coating film is 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less.

The second base coating film may be used alone or in combination of two or more different types with different hues, film thicknesses, etc. For example, in one portion of the red-based multi-layer coating film, the hue of the second base coating film may be 3R, and in another portion of the red-based multi-layer coating film, the hue of the second base coating film may be 7R.

- Clear coating film The clear coating film of the red-based multilayer coating film of the present invention has the function of imparting weather resistance to the red-based multilayer coating film. The clear coating film is not particularly limited, and can be, for example, a known clear coating film described in JP-A-2016-188332.

The clear coating film contains a film-forming resin. The film-forming resin for the clear coating film is not particularly limited, and any known film-forming resin for clear coating films can be used. Examples of the film-forming resin for the clear coating film include the film-forming resins listed above for the white coating film. The film-forming resins may be used alone or in combination of two or more.

In addition to the film-forming resin, the clear coating may contain other ingredients such as UV absorbers, pigments, hardeners, dispersants, defoamers, and leveling agents.

The clear coating film may contain the above-mentioned luster pigment to the extent that the effect of the present invention is not impaired. When the clear coating film contains a luster pigment, the content is, for example, 3 parts by mass or less, 2 parts by mass or less, 1 part by mass or less, 0.5 parts by mass or less, or 0.1 parts by mass or less per 100 parts by mass of the solid content of the coating film-forming resin of the clear coating film. In one embodiment, the clear coating film does not contain a luster pigment.

The thickness of the clear coating is not particularly limited and may be adjusted as appropriate, but is, for example, 10 to 80 μm. In one embodiment, the thickness of the clear coating is 10 μm or more, 20 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, or 70 μm or more. In another embodiment, the thickness of the clear coating is 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, or 20 μm or less.

Other Layers The reddish multilayer coating film of the present invention may have, in order, a whiteish coating film, a first base coating film, a second base coating film, and a clear coating film, and may also have other layers in any position in addition to these.

Figure 2 is a schematic cross-sectional view showing another example of the configuration of the red-based multilayer coating film of the present invention. The red-based multilayer coating film 1 of the example of Figure 2 has, in order, a white-based coating film 10, a metal vapor deposition layer 50, a first base coating film 20, a second base coating film 30, and a clear coating film 40.

In one embodiment, the reddish multi-layer coating film of the present invention has, in order, a white-based coating film 10, a first base coating film 20, a second base coating film 30, and a clear coating film 40. In another embodiment, the reddish multi-layer coating film of the present invention is composed of four layers, in order, a white-based coating film 10, a first base coating film 20, a second base coating film 30, and a clear coating film 40.

In one embodiment, Hontsuaki's red multi-layer coating does not contain a photoluminescent pigment.

The thickness of the red multilayer coating film is not particularly limited and may be adjusted as appropriate, for example, from 40 to 100. In one embodiment, the thickness of the red multilayer coating film is 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 85 μm or more, or 90 μm or more. In another embodiment, the thickness of the red multilayer coating film is 100 μm or less, 90 μm or less, 85 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, or 50 μm or less.

The reddish multilayer coating film of the present invention has a value of 5% or less at a wavelength of 580 nm in a curve obtained by multiplying the spectral reflectance (%) of the reddish multilayer coating film by the spectral luminous efficiency of photopic vision, and has a maximum value of 15% or more at wavelengths of 590 nm to 650 nm on the curve. This allows the reddish multilayer coating film to have high brightness and high saturation.

In the present invention, the spectral reflectance (%) is the spectral reflectance of light received at an angle of 45° (acceptance angle 45°) from the regular reflected light to the incident light direction, relative to light irradiated at an angle of 45° (incident angle 45°) from the normal line of the reddish multilayer coating film on the clear coating film side of the reddish multilayer coating film (see Figure 3). The target wavelength range of the spectral reflectance is 400 nm to 700 nm, and the spectral reflectance is a value obtained by measuring at 10 nm intervals in the wavelength range of 400 nm to 700 nm.

The spectral luminous efficiency is a numerical value (maximum 1) that represents the intensity at which the human eye perceives brightness at each wavelength of light. The photopic spectral luminous efficiency is the CIE standard spectral luminous efficiency for photopic vision. The photopic spectral luminous efficiency values at 5 nm intervals in the wavelength range of 360 nm to 830 nm are specified, for example, in Appendix 8 of the Measurement Unit Regulations, Ministry of International Trade and Industry Ordinance No. 80 of 1992. For example, the photopic spectral luminous efficiency for wavelengths of 450 nm to 650 nm is as shown in Table 1 below, with the maximum spectral luminous efficiency at a wavelength of 555 nm being 1.

In the present invention, it is believed that it is possible to evaluate the hue and texture more closely to visual evaluation by not only the spectral reflectance of the red multilayer coating film, but also by multiplying that spectral reflectance by the spectral luminous efficiency in photopic vision, SS.

Furthermore, in the present invention, the curve obtained from the value SS obtained by multiplying the spectral reflectance of the red-based multilayer coating film by the photopic spectral luminous efficiency (hereinafter, sometimes simply referred to as the "curve of value SS") has a value of 5% or less at a wavelength of 580 nm, and has a maximum value of 15% or more at wavelengths of 590 nm to 650 nm. By having such a curve, the red-based multilayer coating film has high brightness and high saturation. If the value of the curve of value SS at a wavelength of 580 nm is greater than 5%, the color becomes more yellowish, and the color of the multilayer coating film deviates from red. Furthermore, if the maximum value is less than 15% at wavelengths of 590 nm to 650 nm on the curve of value SS, the color of the red-based multilayer coating film becomes black and muddy, and it is not possible to achieve both high brightness and high saturation.

The value of the curve of value SS at a wavelength of 580 nm is 5% or less. The value of the curve of value SS at a wavelength of 580 nm is, for example, 0.1 to 5.0%. In one embodiment, the value of the curve of value SS at a wavelength of 580 nm is 5.0% or less, 4.7% or less, 4.6% or less, 4.5% or less, 4.2% or less, 4.0% or less, 3.8% or less, 3.7% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, or 0.5% or less. In another embodiment, the value of the curve of the value SS at a wavelength of 580 nm is 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 3.7% or more, 3.8% or more, 4.0% or more, 4.2% or more, 4.5% or more, 4.6% or more, or 4.7% or more. In yet another embodiment, the value of the curve of the value SS at a wavelength of 580 nm is 2.5 to 5.0%. In yet another embodiment, the value of the curve of the value SS at a wavelength of 580 nm is 3.0 to 4.7%.

In addition to making the red-based multilayer coating film have the above-mentioned four layers, for example, making the a ^* value of the red-based multilayer coating film 50 or more also contributes to making the value SS 5% or less at a wavelength of 580 nm.

The curve of the value SS has a maximum value of 15% or more at wavelengths of 590 nm to 650 nm. The maximum value of the curve of the value SS at wavelengths of 590 nm to 650 nm is, for example, 15.0 to 40.0%. In one embodiment, the maximum value of the curve of the value SS at wavelengths of 590 nm to 650 nm is 15.0% or more, 16.0% or more, 16.3% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.4% or more, 19.5% or more, 20.0% or more, 20.5% or more, 21.0% or more, 21.5% or more, 22.0% or more, 22.5% or more, 23.0% or more, 23.5% or more, 24.0% or more, 24.5% or more, 25.0% or more, 25.1% or more, 25.3% or more, 25.5% or more, 26.0% or more, 26.5% or more, 27.0% or more, 27.5% or more, 28.0% or more, 28.5% or more, 29.0% or more, 29.5% or more, 30.0% or more, 30.5% or more, 31.0% or more, 31.5% or more, 32.0% or more, 32.5% or more, 33.0% or more, 33.5% or more, 34.0% or more, 34.5% or more, 35.0% or more, 36.0% or more, 37.0% or more, 38.0% or more, or 39.0% or more. In another embodiment, the maximum value of the curve of value SS at wavelengths 590 nm to 650 nm is 40.0% or less, 39.0% or less, 38.0% or less, 37.0% or less, 36.0% or less, 35.0% or less, 34.5% or less, 34.0% or less, 33.5% or less, 33.0% or less, 32.5% or less, 32.0% or less, 31.5% or less, 31.0% or less, 30.5% or less, 30.0% or less, 29.5% or less, 29.0% or less, 28.5% or less, 28.0% or less, 27.5% or less, 27.0% or less, 26.5% or less, 26.0% or less, 25.5% or less, 25.3% or less, 25.1% or less, 25.0% or less, 24.5% or less, 24.0% or less, 23.5% or less, 23.0% or less, 22.5% or less, 22.0% or less, 21.5% or less, 21.0% or less, 20.5% or less, 20.0% or less, 19.5% or less, 19.4% or less, 19.0% or less, 18.5% or less, 18.0% or less, 17.5% or less, 17.0% or less, 16.5% or less, 16.3% or less, or 16.0% or less.

In addition to forming the red-based multilayer coating film into the four layers described above, for example, making the L ^* value and C ^* value of the first base coating film 65 or more also contributes to obtaining a value SS having a maximum value of 15% or more at wavelengths of 590 nm to 650 nm.

The wavelength range in which the curve for value SS has a maximum value of 15% or more is 590 nm to 650 nm, but from the viewpoint of obtaining a red color with higher brightness and higher saturation in a red-based multi-layer coating film, in a preferred embodiment, it has a maximum value of 15% or more at a wavelength of 600 nm to 630 nm, and in another preferred embodiment, it has a maximum value of 15% or more at a wavelength of 610 nm.

The greater the value SS at a wavelength of 660 nm, the higher the brightness and saturation. The value SS at a wavelength of 660 nm of the curve of the value SS is, for example, 0.1 to 5.0%. In one embodiment, the value SS at a wavelength of 660 nm of the curve of the value SS is 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, or 0.5% or less. In another embodiment, the value SS at a wavelength of 660 nm of the curve of the value SS is 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, or 4.5% or more.

In the curve of the value SS, the value SS and the shape of the curve in the wavelength range shorter than 580 nm are not particularly limited, but for example, it is preferable that the curve of the value SS has a maximum value of 5.0% or less in the wavelength range of 500 nm to 570 nm. This allows the brightness and saturation of the red multi-layer coating film to be more highly balanced.

In one embodiment, the curve of the value SS has a maximum value of 1.0% or more, 1.5% or more, 1.6% or more, 1.9% or more, 2.0% or more, 2.1% or more, 2.2% or more, 2.3% or more, 2.4% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, or 4.5% or more at wavelengths of 500 nm to 570 nm. In another embodiment, the curve of the value SS has a maximum value of 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.4% or less, 2.3% or less, 2.2% or less, 2.1% or less, 2.0% or less, 1.6% or less, 1.5% or less, 1.0% or less, or 0.5% or less at wavelengths of 500 nm to 570 nm. In yet another embodiment, the curve for the value SS has a maximum value within the range of 1.5 to 5% at wavelengths between 500 nm and 570 nm.

An example of a means for adjusting the value of the curve of the value SS at wavelengths of 500 nm to 570 nm to 1.5% or more is to set the L ^* value and C ^* value of the first base coating film to 65 or more. An example of a means for adjusting the value of the curve of the value SS at wavelengths of 500 nm to 570 nm to 5% or less is to set the a ^* value of the red multilayer coating film to 50 or more.

In one embodiment, the curve for value SS has a maximum value of 5.0% or less at wavelengths between 530 nm and 560 nm. In another embodiment, the curve for value SS has a maximum value of 1.5% to 2.5% or less at wavelengths between 540 nm and 550 nm.

By reducing the value SS at wavelengths of 400 nm to 490 nm, the decrease in saturation of the red multilayer coating film can be suppressed. In one embodiment, the curve of the value SS is such that the value SS is 1.0% or less, 0.7% or less, 0.5% or less, 0.3% or less, 0.2% or less, or 0.1% or less at wavelengths of 400 nm to 490 nm. In another embodiment, the curve of the value SS is such that the value SS is 1.0% or less, 0.7% or less, 0.5% or less, 0.3% or less, 0.2% or less, or 0.1% or less at wavelengths of 400 nm to 450 nm.

In the curve of the value SS, the value SS and the shape of the curve in the wavelength range longer than 670 nm are not particularly limited. The larger the value SS in the wavelength range from 670 nm to 700 nm, the higher the brightness and saturation obtained. The value SS in the curve of the value SS in the wavelength range from 670 nm to 700 nm is, for example, 0.1 to 5.0%. In one embodiment, the value SS in the curve of the value SS in the wavelength range from 670 nm to 700 nm is 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, or 0.5% or less. In another embodiment, the value SS of the curve of the value SS at a wavelength of 660 nm is 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, or 4.5% or more. In yet another embodiment, the value of the curve of the value SS at wavelengths of 670 nm to 700 nm is 1.5 to 2.5%.

- Method for forming a red-based multi-layer coating film The method for forming a red-based multi-layer coating film of the present invention is not particularly limited as long as a predetermined white-based coating film, a first base coating film, a second base coating film and a clear coating film are formed on the surface of the substrate in order, and the predetermined value SS is obtained as described above. For example, an electrodeposition coating film is formed on the substrate, then a coating composition for a white-based coating film is applied on the electrodeposition coating film to form a white-based coating film, and then dried to form a white-based coating film, then a coating composition for a first base coating film is applied on the white-based coating film to form a first base coating film, and then dried to form a first base coating film, then a coating composition for a second base coating film is applied on the first base coating film to form a second base coating film, and then a coating composition for a clear coating film is applied on the second base coating film to form a clear coating film, and then dried to form a clear coating film, thereby obtaining a red-based multi-layer coating film. Alternatively, one or more of the coating composition for the white coating film, the coating composition for the first base coating film, the coating composition for the second base coating film and the coating composition for the clear coating film may be applied to form an uncured coating film, and then the next coating composition may be applied onto the uncured coating film to form a further uncured coating film, and the two or more uncured coating films may be cured together.

The coating composition for each coating film can be prepared by mixing the pigment and film-forming resin described above, as well as optionally adding solvents, UV absorbers, curing agents, dispersants, defoamers, leveling agents, curing catalysts, antioxidants, etc.

The coating composition of each coating may be a water-based coating composition or a solvent-based coating composition.

Examples of solvents include water, ester solvents, ether solvents, alcohol solvents, ketone solvents, aliphatic hydrocarbon solvents, and aromatic solvents.

When any of the coating films in the red multi-layer coating film is heated to harden it, the heating temperature is not particularly limited and may be adjusted as appropriate. The heating temperature is, for example, 80 to 180°C. The heating time is, for example, 5 to 60 minutes. The coating film may be dried at room temperature without heating.

The substrate on which the red multilayer coating film of the present invention is formed is not particularly limited, and examples thereof include metals, plastics, and foams. Examples of metals include iron, copper, aluminum, tin, zinc, and alloys thereof.

(vehicle)
The vehicle according to the present invention has the above-mentioned red-based multi-layer paint film, with the clear paint film side positioned on the outside, thereby giving the vehicle high lightness and high chroma.

The vehicle is not particularly limited and may be any known vehicle. Examples of the vehicle include automobiles such as passenger cars, buses, trucks, and motorcycles; motorbikes; trains; and racing cars.

The vehicle may have a red-based multi-layer coating on at least a portion of the vehicle, for example, the vehicle body, tires, wheels, or vehicle interior.

The red-colored multi-layer coating on the vehicle may be of one type alone or a combination of two or more types.

The method for manufacturing a vehicle of the present invention involves using a vehicle as a substrate and carrying out the method for forming a red-based multi-layer coating film described above to manufacture the vehicle.

(Goods)
In another embodiment of the present disclosure, it is also possible to provide an article having the above-mentioned red-based multi-layer coating film, with the clear coating film side being positioned on the outside. This allows the article to have high brightness and high chroma.

The article or substrate to be coated is not particularly limited, and examples include vehicle tires; ships; aircraft such as airplanes and helicopters; walls, floors, ceilings, roofs, pillars, signs, digital signs, doors, gates, and windows of buildings or structures such as detached houses, apartment complexes, office buildings, public facilities, commercial facilities, research facilities, military facilities, and tunnels; glass of vehicles and buildings; bridges; vending machines; road signs; traffic lights; street lights; LED, LCD, and light bulb type electronic billboards; work machines, construction machines; stone monuments; gravestones; packaging materials; mirrors; toys; transparent bodies such as glass, acrylic, and polycarbonate cases, containers, resin plates, and films.

The red-colored multi-layer coating film on the article may be of one type alone or a combination of two or more types.

As a method for manufacturing an article, the article can be manufactured by carrying out the above-mentioned method for forming a red-based multi-layer coating film on the article as a substrate.

The present invention will be described in more detail below with reference to examples. However, these examples are intended to illustrate the present invention and are not intended to limit the present invention in any way.

Details of the materials used in the examples are as follows:
Polyester-melamine paint: Nippon Paint Automotive Coatings' product name "OP-30P White"
White pigment: CR-97
Acrylic resin emulsion: Phosphate group-containing acrylic resin prepared in the same manner as in Production Example 13 described in paragraph [0100] of JP-A No. 2020-002244: Nonionic surfactant prepared in the same manner as in Production Example 4 described in paragraph [0121] of JP-A No. 2018-135439: Trade name "Noigen EA-207D" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., amphiphilic compound, number average molecular weight 4200, solid content 55%
Linoleic acid: Kishida Chemical Co., Ltd. Mixed alkylated melamine resin: Cymel 327 (solid content 90%), manufactured by Allnex Co., Ltd.
Electrodeposition coating composition: Trade name "Power Top U-50" manufactured by Nippon Paint Automotive Coatings Co., Ltd.
Paint composition for clear coating: Trade name "Macflow-O-1810" manufactured by Nippon Paint Automotive Coatings Co., Ltd.

Details of the apparatus used in the examples are as follows.
Spray gun: Anest Iwata Corporation product name "W-101-132G"
Multi-angle spectrophotometer: X-Rite product name "MA68II"

Preparation of white-based coating composition 1: 70% by mass of white pigment CR-97 was mixed into "OP-30P White". The mixture was diluted using a No. 4 Ford cup so that the outflow time measured at 20°C was 25 seconds, to prepare white-based coating composition 1.

Preparation of Coating Composition 2 for White Coating Films Coating Composition 2 for white coating films was prepared in the same manner as in Preparation of Coating Composition 1 for white coating films, except that the amount of white pigment was changed to 69 mass %.

Preparation of First Base Coating Coating Compositions 1 to 6 The components shown in Table 2 were mixed and uniformly dispersed. Dimethylaminoethanol was then added to the dispersion so that the pH was 8.1. The dispersion was then diluted with deionized water to prepare First Base Coating Coating Compositions 1 to 6 having the resin solids concentrations shown in Table 2.

Preparation of second base coating film coating compositions 1 to 3 The components shown in Table 2 were mixed and uniformly dispersed. Dimethylaminoethanol was then added to the dispersion so that the pH was 8.1. The dispersion was then diluted with deionized water to prepare second base coating film coating compositions 1 to 3 having the resin solids concentrations shown in Table 2.

The following coated plate was prepared as a substrate intended for a vehicle body: A zinc phosphate-treated dull steel plate measuring 0.8 mm in thickness, 30 cm in length and 40 cm in width was electrocoated with the electrodeposition coating composition to a dry film thickness of 20 μm, and baked at 160°C for 30 minutes to prepare the coated plate.

Example 1
The coating composition 1 for white coating film was applied on the coated plate with a spray gun, and baked at 140°C for 30 minutes to form a white coating film. Next, the coating composition 1 for the first base coating film was applied with a spray gun, set (left alone) for 4 minutes, and preheated at 80°C for 5 minutes. Next, the coating composition for the second base coating film was applied with a spray gun, set for 4 minutes, and preheated at 80°C for 5 minutes. Next, the coated plate (hereinafter referred to as "coated plate") was allowed to cool to room temperature, and the coating composition for clear coating film was applied with a spray gun and set for 7 minutes. Next, the coated plate was baked at 140°C for 30 minutes to obtain a coated plate having a red multi-layer coating film.

Examples 2 to 4, 6 to 7
Except for changing the coating composition 1 for the first base coating film to that shown in Table 3, a multilayer coating film was formed in the same manner as in Example 1, and a coated plate having a red-colored multilayer coating film was obtained.

Comparative Example 1
Except for changing the thickness of the white coating film to 20 μm, not using a paint composition for the first base coating film (a first base coating film was not formed), and replacing paint composition 1 for the second base coating film with paint composition 2 for the second base coating film, a multilayer coating film was formed in the same manner as in Example 1, and a coated plate having a multilayer coating film was obtained.

Comparative Example 2
Except for replacing the white-based coating film coating composition 1 with the white-based coating film coating composition 2 and replacing the second base coating film coating composition 2 with the second base coating film coating composition 3, a multilayer coating film was formed in the same manner as in Comparative Example 1, and a coated plate having a multilayer coating film was obtained.

Using a multi-angle spectrophotometer, the L ^* value of the white coating film and the L ^* , a ^* , b ^* and C ^* values of the multi-layer coating film were measured under the following conditions: Room temperature measurement: about 25°C, 3 measurements were taken, and the average value of the 3 measurements was calculated. The measurement results are also shown in Table 4.

Using a multi-angle spectrophotometer, the spectral reflectance of the multi-layer coating was measured under the following conditions, as shown in Figure 3: Room temperature measurement: Approximately 25°C, measurements were taken three times at 10 nm intervals in the measurement wavelength range of 400 to 700 nm, and the average value of the three measurements was calculated. The obtained spectral reflectance was multiplied by the photopic spectral luminous efficiency in Appendix 8 above to obtain the value SS. The results are also shown in Table 4.

According to the present invention, it is possible to provide a red-based multi-layer coating film having high brightness and high chroma. According to the present invention, it is possible to provide a vehicle having a red-based coating film having high brightness and high chroma.

According to the present invention, it is possible to provide a red-based multi-layer coating film having high brightness and high saturation. According to the present invention, it is possible to provide a vehicle having a red-based coating film having high brightness and high saturation.

1: Red-based multi-layer coating film 10: White-based coating film 20: First base coating film 30: Second base coating film 40: Clear coating film 50: Metal vapor deposition layer

Claims (3)

In order,
A white coating film having an L ^* value of 88 ;
a first base coat having a hue of 1YR to 10Y on the Munsell Color System;
a second base coat having a hue of 1R to 10R on the Munsell Color System;
A red-based multi-layer coating film having a clear coating film,
A reddish multilayer coating film, in which a value at a wavelength of 580 nm in a curve obtained from a value SS obtained by multiplying the spectral reflectance of the reddish multilayer coating film by the photopic spectral luminous efficiency is 3.0 to 4.7% , and the curve has a maximum value of 16.3 to 33.0% in the wavelength range of 590 nm to 650 nm (wherein the spectral reflectance is the spectral reflectance of light received at a receiving angle of 45° with respect to light irradiated at an incident angle of 45° with respect to the normal to the reddish multilayer coating film on the clear coating film side of the reddish multilayer coating film). The red multilayer coating film according to claim 1, which has a maximum value within a range of 1.5 to 5% at wavelengths of 500 nm to 570 nm on the curve. A vehicle having the red-based multi-layer coating film according to claim 1 or 2, with the clear coating film side positioned on the outside.

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