JPH0428541A - Topcoating film - Google Patents

Abstract

PURPOSE:To improve the weather resistance of a color clear and marring resistance, and to enhance the dispersion of a pigment by forming a base film composed of an acrylic resin or a polyester resin formed on the surface of an article to be coated and a clear film being shaped onto the base film and consisting of fluoroplastics containing the particulate pigment. CONSTITUTION:A metallic base film 5 is formed onto the surface of a foundation layer 2. Metallic base paints contain a polyester-melamine resin and aluminum pieces 3 or mica pieces resulting in the irregular reflection of metallic paints and a pigment 4 composed of an inorganic or organic material. In a topcoated film, the surface of the metallic base film 5 is coated with the metallic base paints and clear paints in a wet-on-wet manner, and these metallic film 5 and clear film 6 are dried simultaneously. The clear paints consist of fluoroplastics represented by a vinyl monofluoride resin, a vinyl difluoride resin, etc. Fluoroplastics have a particulate pigment 7 in which a pigment having the color same as or different from the pigment 4 contained in the metallic base paints 5 is atomized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to, for example, top coatings for automobiles, and in particular improves the weather resistance and pigment dispersibility of pigments in color clears.

(Prior art) Solid paint, metallic paint, pearl paint, etc. are known as conventional top coats for automobiles, but in recent years, in order to further enhance the design of the exterior, atomized pigments have been added to the clear paint. The development of color clears is progressing.

As shown in FIG. 5, metallic painting using color clear is performed by forming a base layer 2 such as electrodeposition coating or intermediate coating on a steel plate 1, and applying aluminum pieces 3 and pigments 4 on this base 2. A color clear coating film 6 is formed without drying (hereinafter referred to as wet-on-wet). This color clear coating film 6 contains pigments 4 contained in the metallic base coating film 5.
A finely divided pigment 7 having a smaller particle size is included, and this finely divided pigment 7 works together with the pigment 4 of the metallic base coating 5 and the aluminum pieces 3 to create a deep and vivid design. It will be played.

(Problem to be Solved by the Invention) By the way, color clear is produced by adding melamine resin (C3N3 (NH2) 3) as a crosslinking agent to acrylic resin (CH2-CHCOOH) and performing a crosslinking reaction under heating, as shown in Figure 6. A coating film is formed, and by increasing the crosslinking density, the weather resistance, scratch resistance, etc. of the coating film can be improved.

As a means of increasing crosslinking density, C0O
A method of increasing the blending amount of H groups or 5iOH groups has been adopted, but increasing the amount of C0OH groups will leave C0OH groups that cannot react with melamine resin, causing paint film deterioration. Ta. In other words, unreacted C0OH groups are easily separated into Co-OH by water or light, and the OR of Co-OH and the H of H2O generate new H2O, and the relatively stable C0OH becomes unstable. It becomes a CO. In the industry, it is believed that the presence of this unstable CO is the cause of progressing paint film deterioration. Therefore, conventional color clears made of acrylic-melamine resins have problems in terms of weather resistance and scratch resistance.

Furthermore, color clears made of acrylic-melamine resins have the problem that even if the pigment is made into fine particles, it tends to re-condense, making it impossible to provide a bright coating film. This is because in the coating structure formed by the crosslinking reaction of acrylic-melamine resin, the intermolecular force of C, Cool, or melamine is relatively small, so even if the pigment is made into fine particles, it cannot move freely between the molecules. It is thought that this is because they tend to gather in one place.

The present invention was made in view of the problems of the conventional technology, and aims to improve the weather resistance and scratch resistance of Color Clear, and to provide a vivid coating film by improving the dispersibility of pigments. The purpose is to

(Means for Solving the Problem) To achieve the above object (the top coating film of the present invention consists of a base coating film made of acrylic resin or polyester resin formed on the surface of the object to be coated, and a base coating film formed on the surface of the object to be coated, and It is characterized by having a clear coating film made of a fluororesin containing a finely divided pigment.

(Function) Since the clear coating film according to the present invention configured as described above is composed of a fluororesin, the atomized pigment is protected from ultraviolet rays by the fluorine atoms having a large particle size and strong bonding force. . In addition, since the atomized pigment is appropriately dispersed between the large particle size fluorine atoms and cannot move freely in the paint, the atomized pigment does not re-condense and the dispersibility of the atomized pigment is reduced. improves. This improves the weather resistance and scratch resistance of the pigment, and also improves the dispersibility of the pigment, making it possible to provide a coating film with excellent coating performance and vivid colors.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing the structure of a coating film according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram illustrating the chemical bonding state of the clear coating film according to the embodiment.

The top coat film of the present invention is preferably applied mainly to metallic coatings or pearl coatings, but can also be applied to solid coatings depending on the case.

In the top coating film of this embodiment, as shown in FIG. 1, a base layer 2 is first formed on a steel plate 1 such as an outer panel of an automobile.

The base layer 2 according to this embodiment includes: - pre-treatment of automobiles such as boat fishing;
Consists of electrodeposition and intermediate coating. Specifically, the unpainted body transported from the car body welding process is cleaned in a cleaning process to remove rust preventive oil applied during the pressing process and dust adhering to the body during the car body welding process. This cleaning process consists of hot water washing at 40 to 50°C, degreasing, and chemical conversion treatment, and its main tasks are dust removal and the formation of a chemical conversion film that improves the adhesion between the electrodeposition paint and the steel plate, which will be described later. It is a purpose. After this cleaning and chemical conversion treatment process, the body is then dried and transported to the undercoating process. The undercoating process is
For passenger cars, electrodeposition coating is generally applied, but electrostatic coating can also be applied. In this electrocoating process, the body is completely immersed in an electrocoat bath containing electrocoating paint, so-called full-deep coating, and a positive voltage is applied to the paint side and a negative voltage is applied to the body side. Cationic electrodeposition is preferred from the viewpoint of anti-complexity performance. Next, the body coated with this electrodeposition is heated and dried at a high temperature of approximately 200°C to form an electrodeposition coating (
film thickness 10-25 μm).

The body with the electrodeposited coating is carried to the intermediate coating booth after undergoing a rust prevention process (such as applying anti-chip material on the underside of the floor).
An intermediate paint is applied (film thickness 15 to 30 μm). The intermediate coating is a thermosetting coating mainly composed of polyester-melamine resin, and preferably has excellent weather resistance and adhesion to the top coating.

In addition, an inorganic pigment or an organic pigment may be used as the coloring pigment of the intermediate coating to give the same color as the outer panel color (so-called inner panel color), and may also be used as the base layer 2 of this example. It is possible.

In this way, the base layer 2 of this example is formed.
It is not particularly limited to the specific examples mentioned above.

In the top coating film of this example, a metallic base coating film 5 is formed on the surface of this base layer 2 (film thickness 20 to 3
0μm).

The metallic base paint used in this example is made of polyester-melamine resin, which is the same material as the intermediate coating, aluminum pieces 3 or mica pieces, which are the diffuse reflection material of the metallic paint, and an inorganic or organic material. Pigment 4. In this example, polyester-melamine resin was used as a component of the metallic base coating film 5, but the present invention is not limited thereto, and alkyd-melamine resin, polyester-alkyd-melamine resin, acrylic-melamine resin It is also possible to configure them respectively. Further, as the diffused reflection material 3, aluminum powder or mica flakes may be selected depending on the coating specifications, and it is also possible to mix the two at a predetermined mixing ratio.

The top coating film of this example is this metallic base coating film 5.
A metallic base paint and a clear paint are applied wet-on-wet to the surface of the metallic base paint 5 and the clear paint film 6 are simultaneously dried to form a top coat film.

The clear paint according to this embodiment is made of a fluororesin represented by -vinyl fluoride resin (vinyl fluoride resin), vinyl difluoride resin (vinylidene fluoride), vinyl trifluoride resin, and the like.

Further, the atomized pigment 7 is formed by atomizing a pigment of the same color or a different color from the pigment 4 contained in the metallic base coating film 5 described above.

Since the clear coating film 6 according to this embodiment configured in this way is composed of a fluorine-based resin, as shown in FIG. The chemical pigment 7 is protected from ultraviolet rays. In addition, since the atomized pigment 7 is appropriately dispersed between the fluorine atoms 8 having large particle diameters and cannot move freely in the paint, the atomized pigment 7 is not recondensed and the atomized pigment is Improves dispersibility.

This improves the weather resistance and scratch resistance of the pigment, and also improves the dispersibility of the pigment, resulting in excellent coating performance.
Moreover, it is possible to provide a coating film with vivid colors.

Figure 3 is a graph measuring the dispersibility (relationship between particle size and frequency) of the pigment contained in the clear paint according to this example, and Figure 4 is a graph of the pigment contained in the conventional clear paint. It is a graph obtained by measuring pigment dispersibility (relationship between particle size and frequency).

The pigment dispersion in the clear paint made of the fluororesin of this example is mostly 0.5 μm or less (see Figure 3), whereas the pigment dispersion in the clear paint made of the fluororesin of this example is different from that of the conventional clear paint made of acrylic-melamine resin. 0.5 to 4.0μ
m (see Figure 4). As is clear from these measurement data, if the composition is made of a fluororesin with a large atomic particle size as in this example, the dispersibility of the atomized pigment will be greatly improved, and this atomized pigment 7 and The pigment 4 of the metallic base coating film 5 and the aluminum pieces 3 work together to create a deep and vivid design.

(Effects of the Invention) As described above, according to the top coating film of the present invention, a base coating film made of acrylic resin or polyester resin formed on the surface of the object to be coated, and a base coating film formed on this coating film,
Because it has a clear coating film made of fluororesin containing atomized pigment, it has excellent weather resistance and scratch resistance, and the clear coating film has excellent pigment dispersibility, resulting in a bright topcoat coating. can be provided.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of a coating film according to an embodiment of the present invention, Fig. 2 is a conceptual diagram illustrating the chemical bonding state of a clear coating film according to the embodiment, and Fig. 3 is a cross-sectional view showing the structure of a clear coating film according to an embodiment of the present invention. Figure 4 is a graph measuring the dispersibility (relationship between particle size and frequency) of pigments contained in conventional clear paints. FIG. 5 is a sectional view showing the structure of a conventional coating film, and FIG. 6 is a conceptual diagram illustrating the chemical bonding state of a conventional clear coating film. 1... Steel plate, 2... Base treatment,
3... Aluminum piece, 4... Pigment, 5...
・Metallic base coating film, 6... Clear coating film, 7...
・Atomized pigment. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] It is characterized by having a base coating film made of acrylic resin or polyester resin formed on the surface of the object to be coated, and a clear coating film made of fluororesin containing atomized pigment formed on this coating film. Topcoat film.