JPH0461967A - Applying method for film protective agent for automobile - Google Patents

Abstract

PURPOSE:To prevent the contamination or scratch of a film by applying a film protective agent composed of hot melt powder wax immediately after the baking of topcoat paint to form a wax film. CONSTITUTION:A car body having an electrodeposition film 2 formed thereto is fed in an intercoat booth through an corrosion-proof process (floor back chipping-resistant material coating process) to be coated with intercoat paint in 15-30mum thickness. A topcoat film 4 is formed to the surface of the intercoat layer 3 in 20-30mum thickness and pigment composed of an inorg. or org. material is contained in a polyester/melamine resin having the same material quality as the intercoat paint. When the topcoat film 4 is formed, a film protective agent is applied to the car body before the car body is fed in an outfitting process. The film protecting agent is powder wax using no solvent or dispersing medium and heated to the m.p. of the powder wax or higher to form a solidified wax film on the topcoat film 4 of the car body through a process of melting casting film formation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a paint film protectant applied to the outer panel of an automobile body.

(Prior Art) In the automobile industry, a product distribution process is generally adopted in which a completed vehicle completed at a manufacturing factory is transported to a dealership, stored for a predetermined period of time, or delivered to a user without being stored. In order to protect finished cars from dust, rain, etc. in the atmosphere during this distribution process, a type of paint called a paint film protectant is applied to the top coat of the car.

Conventional paint film protectants are solvent-based waxes that are applied using an airless paint gun, etc., after each part is assembled onto the car body after the painting process (bottle-making process), and after various vehicle inspection processes. (See Figure 4).

This may cause discoloration of the paint film during transportation or storage,
It is possible to suppress dullness and the like and prevent a significant decrease in product value.

(Problem to be solved by the invention) However, in the conventional method of applying a paint film protectant, it is necessary to remove the protectant with a petroleum solvent before handing it over to the user, which is an extremely difficult task. there were. Furthermore, since a solvent-based wax is used as a protective agent, there is a risk that the coating film may swell or be contaminated by the solvent of the protective agent.

On the other hand, after the painting process, various parts are assembled on the car body in the bottle manufacturing process, but not only do paint film scratches frequently occur during the dovetailing process, but also paint film contamination (or Mainly, "stains" caused by the calcium content in the shower test water sometimes appeared.

The present invention was made in view of the problems of the prior art, and includes problems such as paint film contamination caused by solvents contained in protective agents,
The purpose is to prevent paint film contamination or scratches that occur during the manufacturing process, and to omit the work of removing the protective agent.

(Means for Solving the Problems) In order to achieve the above object, the coating method of the automotive paint film protectant of the present invention is such that immediately after baking the top coat applied to the exterior of the vehicle, the top coat is heated. The method is characterized in that a paint film protectant made of melted powder wax is applied, and then this paint film protectant is heated to form a wax film on the top coat film.

(Function) Since the present invention configured as described above uses heat-melting powder wax as a protective agent, it does not contain solvents that cause paint film swelling, paint film contamination, etc. It is possible to solve problems such as paint film contamination caused by protective agents.

In addition, since the protective agent coating process is performed immediately after the top coat, the coating film can be effectively protected from scratches and coating contamination during the bottle making and inspection processes that follow the coating process. .

Furthermore, if heat-melting powder wax is used as a protective agent, a solidified wax film is formed on the top coat, so there is no need to remove this protective agent thereafter.

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

Fig. 1 is a process diagram showing a coating method according to an embodiment of the present invention, Fig. 2 is a sectional view of a coating film showing the structure of a coating film formed by the same embodiment, and Fig. 3 is a process diagram showing a coating method according to an embodiment of the present invention. FIG. 3 is a front view showing a powder wax application process.

The coating method of the paint film protectant of the present invention is a general 3-coat 3-coat coating method.
Not only bake painting but also 2 coats that omit intermediate coating 2
Although it can be applied to bake painting, this example describes a 3-coat, 3-bake coating system in which an electrodeposition coating film, an intermediate coating film, and a top coating film are formed on a steel plate. do.

The coating film structure of this example is a general three-coat, three-layer coating system, and as shown in FIG. 2, pretreatment, electrodeposition 2, intermediate coating 3, and and top coat 4.

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. The body that has undergone the cleaning and chemical conversion treatment steps is then dried and transported to the undercoating step. In the undercoating process, electrodeposition coating is generally applied to passenger cars. Electrodeposition painting is performed by so-called full-deep painting, in which the body is completely immersed in an electrodeposition bath containing the electrodeposition paint, and the painting is performed by applying a positive voltage to the paint side and a negative voltage to the body side. Cationic electrodeposition is preferred for antirust performance.

Next, about 200 coats of the body with these 17 coats of paint were painted.
It is heated and dried at a high temperature of .degree. C. to form an electrodeposited coating film 2 (film thickness: 10 to 25 .mu.m).

The tenon on which the electrodeposited coating film 2 has been formed is carried into an intermediate coating booth after undergoing a rust prevention process (such as a process of applying an anti-chip material to the underside of the floor), and is coated with an intermediate coating (film thickness: 15 to 30 μm). The intermediate coating is preferably a thermosetting coating mainly composed of polyester-melamine resin, and has excellent weather resistance and adhesion to the top coating. It is also possible to use an inorganic pigment or an organic pigment as a coloring pigment in the intermediate coating to give the same color as the exterior (so-called interior coating color) and use it as the base layer in this example. It is.

In this way, the electrodeposition layer 2 and the intermediate coating layer 3 of this example are
is formed, but is not particularly limited to the specific example described above.

The top coating film 4 according to this embodiment is formed on the surface of this intermediate coating layer 3 (film thickness 20 to 30 μm), and is made of polyester-melamine resin, which is the same material as the intermediate coating, and is made of an inorganic or organic material. Contains pigments consisting of. In this example, polyester-melamine resin was used as a composition element of 1-coating film 4, but the present invention is not limited thereto, and alkyd-melamine resin, polyester-alkyd melamine resin, acrylic-melamine resin , urethane resin, or the like. In addition, solid painting, metallic painting, or burl painting, etc.
It can be applied to all types of conventional coating systems.

Once the top coat 4 is formed in this way, the paint film protectant of this example is applied before the vehicle body is transported to the bottle making process. In the normal painting process, there is a so-called coating completion inspection process that inspects the topcoat surface condition immediately after the topcoat drying process and determines whether or not to repaint, so this coating completion inspection process is passed. It is preferable to install a protective agent application process and its drying process in the process through which the coated vehicle body passes.

The coating film protectant of this example is a powdered wax that does not use a solvent or a dispersion medium, and undergoes a melting-flowing-film-forming process by heating the wax to a temperature above the melting point of the powdered wax. Therefore, compared to conventionally used solvent-based protective waxes, since no solvent or dispersion medium is used, there is no adverse effect on the top coat 4, etc., and it has the advantage of improving the environmental conditions of the painting process. are doing. In addition, since there is no need for dilution work or viscosity adjustment, T
The number can also be reduced.

Further, the powder wax of this embodiment is applied by electrostatic coating. This is mainly to prevent the wax from flowing when powdered wax is applied to the vertical parts of the car body. For example, as shown in FIG. 3, a floor conveyor 6 is installed in a wax booth (not shown), and a painting cart 7 carrying a vehicle body 1 is conveyed by this floor conveyor.

A gate-shaped reciprocating automatic machine 8 is provided, side painting guns 9, 9 that reciprocate up and down are arranged on both sides, and a top painting gun 10 that reciprocates left and right is arranged at the top. A powder wax supply device 11 consisting of a wax tank containing powder wax and a pressure feeding device such as a compressor is connected to each of these coating guns 9.10, and each coating gun 9.10 is connected to a powder wax supply device 11 that generates high pressure. A high voltage from the container 12 is applied. Note that the coating is not limited to the automatic reciprocating machine as in this embodiment, and a coating robot or the like may be provided.

After applying such heat-melting powder wax, the outer panel of the vehicle body is heated to a temperature equal to or higher than the melting point of the powder wax used. Powder coatings are significantly different from solvent-based coatings in terms of how the powder is spread over the surface of the object to be coated and how it is formed into a film. There is. Therefore, it is necessary to pay sufficient attention to uniform coating by electrostatic coating and heating conditions in the heating process for the powder wax of this example as well.

A solidified wax film 5 is formed on the top coat of the vehicle body which has undergone the above powder wax application process and wax melting process. After the wax film 5 is formed on the outermost surface in this way, the car body is transported to the bottle manufacturing process, various parts are assembled to complete the car, and a shower test etc. is performed in the vehicle inspection process before transportation. provide

As described above, according to the coating method of the paint film protectant of this example,
Since heat-melting powder wax is used as a protective agent, this powder wax does not contain solvents that can cause paint film swelling or staining. Problems such as pollution can be solved.

In addition, since the protective agent coating process is performed immediately after the top coat and before the pasting process, the paint film can be effectively protected from scratches and paint film contamination during the bottle making and inspection processes. can.

Furthermore, in the coating method of the paint film protectant of this example,
Since a solidified wax film is formed on the top coat, there is no need to remove this protective agent before delivery to the user.

(Effects of the Invention) As described above, according to the coating method of the automotive paint film protectant of the present invention, immediately after baking the paint, the paint film protectant made of heat-melting powder wax is applied. Since a wax film is formed by using a wax film, it is possible to prevent paint film contamination due to the solvent contained in the protective agent, and paint film contamination or scratches that occur during the manufacturing process. There is no need to remove the applied protective agent.

Moreover, by polishing the wax film formed on the two-coat paint film, it becomes even more glossy, making the paint film maintenance-free.

[Brief explanation of drawings]

Fig. 1 is a process diagram showing a coating method according to an embodiment of the present invention, Fig. 2 is a sectional view of a coating film showing the structure of a coating film formed by the same embodiment, and Fig. 3 is a process diagram showing a coating method according to an embodiment of the present invention. FIG. 4 is a front view showing a powder wax application process, and a process diagram showing a conventional coating method for a paint film protectant. 1... Steel plate (car body), 2... Electrodeposition, 3... Intermediate coating, 4... Top coating, 5... Wax film. Figure 2

Claims (1)

[Claims] Immediately after baking the top coat applied to the exterior of the car,
A paint film protectant made of heat-melting powder wax is applied onto the top coat film, and then a wax film is formed on the top coat film by heating the paint film protectant. How to apply automotive paint film protectant.