JP2533966B2 - Red top coat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a red-based topcoat film which is preferably applied to topcoating of automobiles and the like.

(Prior Art) As shown in FIG. 2, the so-called three-coat coating has an electrodeposition coating 2 which is an undercoat formed on a steel plate 1 and the electrodeposition of this electrodeposition. Intermediate coating film 3 formed on coating film 2 and top coating film 13 formed as the uppermost layer
It is a coating consisting of. This electrodeposition coating is a coating composed mainly of epoxy resin for the purpose of preventing rusting of steel sheets, and is a relatively thin coating with a dry film thickness of 10 to 25 μm. Is formed by the dipping coating method because it needs to be applied to the entire steel plate including the inner surface of the bag structure portion. The intermediate coating film is a coating film made of a polyester resin or the like whose main purpose is to improve the smoothness, image clarity and adhesion of the top coating film, and has a dry film thickness of 15 to 30 μm. It is generally formed as a thick film as compared with the electrodeposition coating film.

On the other hand, solid coating, metallic coating, pearl coating, etc. are known as the top coating forming the outermost layer of the vehicle body outer panel. Among them, the red metallic top coating is the surface of the intermediate coating 3. After applying a metallic base coating 11 containing a red color pigment 9 such as azo, quinacridone, and perylene, and a bright pigment 10 such as aluminum and mica,
Wet-on-wet clear paint with no pigment 12
Is applied. The main purpose of this topcoat is to improve the appearance of the product, such as automobiles, while improving the appearance of the steel sheet, as well as preventing rust on the steel sheet. The development of the top coating film has has been promoted.

(Problems to be Solved by the Invention) By the way, although the degree of color vividness is scaled as the saturation in the Munsell color system, the same wavelength range (64
Even in the red color (0 to 780 nm), it is possible to obtain a bright red coating by increasing the saturation, which is advantageous in increasing the commercial value of automobiles.

However, when the concentration of the red coloring pigment is increased in order to increase the saturation of red color in the conventional 2-coat 1-bake metallic coating, the bright pigment is hidden by the coloring pigment, and a sufficient bright feeling cannot be obtained.

The present invention has been made in view of the above problems of the conventional art, and an object of the present invention is to provide a red metallic coating film which is bright and has an excellent glittering feeling.

(Means for Solving the Problems) In order to achieve the above object, the red-based top coating film of the present invention comprises:
A bright pigment with an average particle size of 40 μm or less formed on the lower ground
A base layer containing 15% by weight or less and 5% by weight or less of a red pigment, and a red fluorescent dye formed on the base layer.
And a clear layer containing 10% by weight or less.

(Function) Under the understanding that the phosphor has a function of absorbing invisible energy such as ultraviolet rays and converting it into visible light (photoexcitation), in the present invention, Since a low red fluorescent dye is used for the clear layer, and the colored layer and the bright layer are separated, when the top coat film according to the present invention is irradiated with sunlight, the red fluorescent dye in the clear layer is photoexcited. Then, the ultraviolet part is shifted to the visible part side by a long wavelength. This enhances the red color of the top coating film, but since the red fluorescent dye used in the present invention has a low hiding power, it can pass the irradiated sunlight to the base layer. Therefore, when the bright pigment and the red pigment contained in the base layer reflect sunlight, it becomes a bright red topcoat film having a bright feeling.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a coating film showing a coating film composition according to an embodiment of the present invention, in which an upper coating film of the present invention is formed through an undercoat on the outer panel coating of an automobile body. .

The base material of this embodiment is a general automobile pretreatment, electrodeposition 2
And the intermediate coating 3. More specifically, the unpainted body that has undergone the car body welding process is first conveyed to the cleaning process, where the rust-preventive oil applied to the body in the pressing process and the dust and the like adhering to the body in the car body welding process. To be removed. This washing process is 40-50
It consists of steps such as hot water washing at ℃, degreasing, chemical conversion treatment, etc., and its main purpose is to remove dust and to form a chemical conversion film that improves the adhesion between the electrodeposition coating material 2 and the steel sheet 1 described later.

The body that has undergone the cleaning and chemical conversion treatment steps is then dried and conveyed to the undercoating step. In the undercoating process, electrodeposition coating is generally performed with a paint made of an epoxy resin. This electrodeposition coating is carried out by so-called full dip coating, in which the body is completely immersed in the electrodeposition tank containing the electrodeposition coating, and the electrodeposition coating is formed on the inner surface of the bag structure of the vehicle body to enhance rust prevention. It is preferable. It should be noted that the electrodeposition coating is preferably cation-type electrodeposition, in which a voltage is applied to the paint side to the positive side and a body side to the negative side to apply the voltage in terms of rust prevention performance.
Then, the body coated with electrodeposition is heated and dried at a high temperature of about 200 ° C. to form an electrodeposition coating film 2 having a dry film thickness of 10 to 25 μm.

The body on which the electrodeposition coating film 2 is formed is then carried into an intermediate coating booth, and an intermediate coating film having a dry film thickness of 15 to 30 μm is formed. The intermediate coating used in this example is a thermosetting coating composed of, for example, a polyester-melamine resin as a main component, and has excellent weather resistance and excellent adhesion to the top coating. Is preferred.

The top coating film according to this embodiment is a base layer 6 and a clear layer 8.
The coating material that constitutes both layers 6 and 8 is applied by what is called wet-on-wet. The base coating material for forming the base layer 6 is a coating material in which an acrylic-melamine resin or the like contains a bright pigment 4, a red pigment 5, and a surface adjusting agent, and the bright pigment 4 includes aluminum, mica,
Micro titanium, graphite carbon, etc. with average particle size
The content is 40 μm or less, preferably 30 to 40 μm.
This is because when the average particle diameter of the bright pigment is larger than 40 μm, the bright pigment 4 to be contained in the base layer 6 projects to the clear layer 8 and is further exposed from the clear layer 8 to the surface of the top coat film. Further, when the amount of the bright pigment 4 is increased, the surface of the base layer 6 becomes not smooth, which adversely affects the quality of the top coat appearance.
It is preferable to set the content to be not more than weight%.

On the other hand, as the red pigment 5 to be added to the base paint,
It is preferable to use azo, quinacridone, perylene, or the red fluorescent dye 7 to be blended in the clear layer 8 described later, and these may be blended alone, or a plurality of red pigments may be blended in combination. Is. Further, the amount of the red pigment 5 blended is preferably 5% by weight or less. This is because if the blending amount of the red pigment 5 is more than 5% by weight, the bright pigment 4 blended in the same base layer 6 is covered and the bright feeling is lowered.

In the clear layer 8 according to this embodiment, a red fluorescent dye 7 is mixed, and as the red fluorescent dye 7, it is preferable to use perylene tetracarboxylic acid diimide. The content of the red fluorescent dye 7 is preferably 10% by weight or less, but when the content is more than 10% by weight, the light transmittance of the clear layer 8 decreases and the light cannot pass to the base layer 6. This is because the glittering feeling of the top coating film is deteriorated.

 Next, the operation of this embodiment will be described.

The red fluorescent dye 7 of this embodiment containing a phosphor has a function (photoexcitation) of absorbing invisible energy such as ultraviolet rays and converting it into visible light. Therefore,
When the top coat film according to the present embodiment is irradiated with sunlight, the red fluorescent dye 7 of the clear layer 8 is photoexcited and the ultraviolet part is shifted to the visible part side by a long wavelength, whereby the red color of the top coat film is Is emphasized.

Moreover, since the red fluorescent dye 7 used in this example has a low hiding power, the irradiated sunlight is allowed to pass through to the base layer 6, and the bright pigment 4 and the red pigment 5 contained in the base layer 6 are passed through. Further, the sunlight is reflected, and in combination with the above-described enhancement effect of red color by the clear layer 8, it becomes a bright red topcoat film having a bright feeling.

The present invention will be further described by embodying the present invention, but the present invention is not limited to this specific example.

Example 1 A 70 mm × 150 mm × 0.8 mm steel plate test piece was pretreated with Granodine SD5000 (manufactured by Nippon Paint Co., Ltd.), which is a chlorine phosphate coating conversion agent, and then Power Top U was used as cation electrodeposition. -100 (manufactured by Nippon Paint Co., Ltd.) was applied to a dry film thickness of 20 μm and baked at 180 ° C. for 20 minutes.

Next, on this electrodeposition coating film, high epico NO1 (manufactured by NOF CORPORATION) as an intermediate coating paint was applied to a dry film thickness of 35 μm and baked at 140 ° C. for 20 minutes.

On the obtained intermediate coating film, Lumogen F was applied to Bellcoat NO6000 (manufactured by NOF CORPORATION) as a base coat paint.
0.5% by weight of Red 300 (manufactured by BASF), aluminum flakes 7
After coating a paint containing 5% by weight of 620NS (manufactured by Toyo Aluminum Co., Ltd.), a flash time of 5 minutes is set, and Bellcoat NO6000 clear (manufactured by NOF Corporation)
A coating containing 1% by weight of Lumogen F Red 300 (manufactured by BASF) was applied to the dry film thickness of 35 μm by wet-on-wet and baked at 140 ° C. for 20 minutes.

Example 2 Lumogen F in the base coat paint used in Example 1
The coating was performed in the same manner as in Example 1 except that Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 3 Coating was carried out in the same manner as in Example 1 except that the amount of aluminum flake 7620NS (manufactured by Toyo Aluminum Co., Ltd.) in the base coat paint used in Example 1 was changed to 10% by weight.

Example 4 The coating was carried out in the same manner as in Example 1 except that the amount of aluminum flake 7620NS (manufactured by Toyo Aluminum Co., Ltd.) in the base coat paint used in Example 1 was changed to 15% by weight.

Example 5 Coating was carried out in the same manner as in Example 2 except that the amount of aluminum flake 7620NS (manufactured by Toyo Aluminum Co., Ltd.) in the base coat paint used in Example 2 was changed to 10% by weight.

Example 6 Coating was carried out in the same manner as in Example 2 except that the amount of aluminum flake 7620NS (manufactured by Toyo Aluminum Co., Ltd.) in the base coat paint used in Example 2 was changed to 15% by weight.

Example 7 Lumogen F in the clear coat paint used in Example 1
The coating was performed in the same manner as in Example 1 except that the amount of Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 8 Lumogen F in the clear coat paint used in Example 2
The coating was performed in the same manner as in Example 2 except that the blending amount of Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 9 Lumogen F in the clear coat paint used in Example 3
The coating was performed in the same manner as in Example 3 except that the compounding amount of Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 10 Lumogen F in the clear coat paint used in Example 4
Coating was performed in the same manner as in Example 4 except that the amount of Red 300 (manufactured by BASF) was set to 5% by weight.

Example 11 Lumogen F in the clear coat paint used in Example 5
Coating was performed in the same manner as in Example 5 except that the amount of Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 12 Lumogen F in the clear coat paint used in Example 6
Coating was performed in the same manner as in Example 6 except that the amount of Red 300 (manufactured by BASF) was changed to 5% by weight.

Example 13 Lumogen F in the clear coat paint used in Example 1
Coating was performed in the same manner as in Example 1 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Example 14 Lumogen F in the clear coat paint used in Example 2
Coating was performed in the same manner as in Example 2 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Example 15 Lumogen F in the clear coat paint used in Example 3
The coating was performed in the same manner as in Example 3 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Example 16 Lumogen F in the clear coat paint used in Example 4
Coating was performed in the same manner as in Example 4 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Example 17 Lumogen F in the clear coat paint used in Example 5
Coating was performed in the same manner as in Example 5 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Example 18 Lumogen F in the clear coat paint used in Example 6
The coating was performed in the same manner as in Example 6 except that the amount of Red 300 (manufactured by BASF) was changed to 10% by weight.

Comparative Example 1 Lumogen F in the base coat paint used in Example 11
The coating was performed in the same manner as in Example 11 except that the amount of Red 300 (manufactured by BASF) was changed to 6% by weight.

Comparative Example 2 The amount of aluminum flake 7620NS (manufactured by Toyo Aluminum Co., Ltd.) in the base coat paint used in Example 12 was 16% by weight.
The coating was performed in the same manner as in Example 12 except that

Comparative Example 3 Lumogen F in the clear coat paint used in Example 17
The coating was performed in the same manner as in Example 17 except that the amount of Red 300 (manufactured by BASF) was set to 11% by weight.

Examples 1 to 18 and Comparative Example 1 thus obtained
The 60 ° gloss gloss value of each of the test pieces of Nos. 3 to 3 was measured using the test method of JIS K-5400 6.7. The results are shown in the table.

Further, the accelerated weather resistance was evaluated by visually observing the surface of the test piece after 500 hours using the test method of JIS K-5400 6.17. If there is no change after 500 hours, it is "○", if it changes slightly, it is "△", if it changes significantly, it is "x".
And the results are shown in the table.

Furthermore, the glitter feeling was evaluated by visually evaluating the metal feeling while tilting the test piece under sunlight. The results are shown in the table, when the metallic feeling is good, “◯”, when it is slightly good, it is “Δ”, and when it is poor, it is “x”.

As is clear from these results, all of Examples 1 to 18 are excellent in gloss, weather resistance and brilliance, while Comparative Example 1
Regarding Nos. 3 to 3, there is a problem in terms of gloss (Comparative Examples 1 and 2) and glitter (Comparative Examples 1 and 3).

(Effect of the invention) As described above, according to the top coating film of the present invention, since a red fluorescent dye having a low coloring power is used for the clear layer and the colored layer and the bright layer are separated, a vivid color is obtained. It is possible to provide an overcoat coating film which is red and has a novel design property with a glittering feeling.

[Brief description of drawings]

FIG. 1 is a sectional view showing the constitution of a coating film according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the constitution of a coating film of a conventional metallic coating. 1 ... Steel plate, 2 ... Electrodeposition layer, 3 ... Intermediate coating layer, 4 ... Bright pigment, 5 ... Red pigment, 6 ... Base layer, 7 ... Red fluorescent dye, 8 ... Clear layer.

Claims (1)

(57) [Claims] 1. A base layer formed on a base, containing 15% by weight or less of a bright pigment having an average particle size of 40 μm or less and 5% by weight or less of a red pigment, and a red-based layer formed on the base layer. 10% by weight of fluorescent dye
A clear coating layer containing the following: