JPS62106873A - Method for painting synthetic resin product in coating separated state - Google Patents

Abstract

PURPOSE:To reduce the number of film baking/curing processes and to dispense with sanding, by preliminarily applying plasma treatment to the surface of a synthetic resin product to enhance the wettability of said surface and subsequently applying differently coating paint to said surface by a wet-on-wet system. CONSTITUTION:After a plate shaped article 1 to be painted made of a polypropylene resin is washed, a strip-like mask 5 due to electroforming is applied to the surface side of a coating separating parting area 1a and the whole is set to an oxygen plasma treatment apparatus 6 and the surface of the article 1 to be painted is activated by plasma irradiation. Thereafter, the masking is detached and first color paint is applied to one treating part provided across a plasma untreated part and, in a wet-on-wet state, second color paint is applied to the other treating part and both parts are baked and cured. Thereafter, both films on the differently coating parting area 1a of the article 1 to be painted are released through an adhesive tape 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for separately painting the surface of a synthetic resin product.

[Conventional technology]

Conventionally, for example, synthetic resins, especially modified polypropylene resins, have been widely used for automobile parts and outer panels.This is because modified polypropylene resins are lightweight and moldable. This is because it not only has excellent heat resistance, impact resistance, weather resistance, etc., but also is relatively inexpensive and easily available.

When painting a synthetic resin product as described above, first, the surface of the synthetic resin product is steam cleaned with a cleaning machine that uses a chlorinated organic solvent such as trichloroethane, and then dried. After applying primer to the entire surface and baking and curing, apply the first color paint to the entire surface and bake and cure. Next, thoroughly sand the first color paint film, mask the necessary areas, and apply the second color paint to other areas and bake.
Let it harden. Finally, the masking is generally removed.

[Problem that the invention seeks to solve]

However, in such a separate painting method for synthetic + 1 fat products, baking and curing processes are required after applying the first color of the top coat and after applying the second color of the paint. Of course, it is necessary to separate the first color paint film and the second color after baking and curing.
There is a problem in that sanding must be performed after applying the first color paint to ensure adhesion with the paint film of the first color.

Therefore, this invention was made to solve the above-mentioned problems, and the surface of a synthetic resin product is subjected to plasma treatment in advance to improve the wettability of the surface and apply a paint for different application. -7 By painting with Toonuesoto, the steps for baking and curing the paint film can be reduced, and the sanding work to improve the adhesion of the paint films to each other can be completely eliminated.

[Means for solving problems]

That is, the method for separately painting a synthetic resin product according to the present invention is a method for separately painting the surface of a synthetic resin product, in which the dividing portion of the synthetic resin product is masked in advance in a band shape and then plasma treated. do the
After removing the masking, the first color paint is applied to one plasma-treated surface using the masked area as a border, and the second color paint is applied to the other plasma-treated surface in a wet-on-wet state. The paint film of a different color and the paint film of a second color are baked and cured at the same time, and then a tape is attached to the separation area to peel off the paint film at that area. be.

As mentioned above, the synthetic resin products are intended to include various synthetic resin products, including parts such as automobile outer panels and bumpers. Also,
Examples of the synthetic resin material include modified polypropylene resin, polyethylene resin, polystyrene resin, FRP resin, and the like.

Further, as the masking material, paper, adhesive tape, synthetic resin sheet, electroformed mask, etc. used in the field of painting technology can be used.

Further, the plasma treatment can be carried out according to a conventional method, for example, by performing glow discharge under low pressure of oxygen gas. To explain more specifically, a synthetic resin product is set in a container of an oxygen plasma treatment device, and
．． generating plasma under reduced pressure of 5 to 1.0 torr;
Plasma treatment can be advantageously carried out by irradiating at a power output of 400 to 1°ooow, a treatment time of 30 seconds to 60 seconds, and a flow rate of 5 to 1 ON m'/min.

Furthermore, as the first color paint and second color paint applied to the surface of the synthetic resin product, the paint applied to the synthetic resin product can be used as is, and there are no particular limitations here. For example, organic solvent-based paints,
Both water-based paints and powder paints can be used.

Furthermore, these coating methods can be used to apply a coating method such as an air spray coating method, an airless coating method, an electrostatic coating method, etc.

Also, in the baking and curing process of the paint film, commonly used hot air circulation drying ovens, dark infrared ray drying ovens, etc. can be used, and there is no need to set special baking conditions.

Furthermore, as the tape for peeling off the painted film, commercially available tapes such as adhesive tapes and pressure-sensitive adhesive tapes that are commonly used can be used. Specifically, cellotape (manufactured by Chiban Co., Ltd.) can be mentioned.

〔Example〕

Hereinafter, the method for separately painting synthetic resin products according to the present invention will be explained in detail based on the drawings.

FIGS. 1 to 8 are process diagrams illustrating the method for separately painting synthetic resin products according to the present invention.

In Figures 1 to 8, 1 is 400X250X1
．． 5mm size polypropylene +! (The object to be painted is a plate-shaped object made of oil, and as shown in FIG. The surface of the object 1 to be coated is cleaned by heating and evaporating the steam Ma with a cooler 4 above the cleaning tank 2 and causing the steam Maii to condense.

Next, as shown in FIG. 2, an electroformed belt-shaped mask 5 is masked in advance on the surface side of the painting separation area 1a of the cleaned object 1, and this is attached to the support stand ( (not shown). Then, a plasma (
(not shown) with an output of 400 to 1,000
Plasma is irradiated for 30 to 60 seconds under conditions of W and a flow rate of 5 to 1 ON m'/min to activate the surface of the object to be coated 10.

After the plasma treatment is completed, the object to be coated 1 is taken out from the oxygen plasma treatment apparatus 6, and the mask 5 masking the separation area 1a for painting is removed. As a result, as shown in FIG. 3, the masked part becomes the plasma untreated part B, and the unmasked part becomes the plasma treated part Aas Ab.

Next, as shown in Figure 4, the untreated part B of the plasma
Then, on one plasma treated area Aa, a polyester-based one-component red urethane paint Ta is air-sprayed from a spray gun 8 as a first color paint, and a red first top coat of 30 to 40 μm is applied. Film Tb
form.

Subsequently, without baking and curing the first top coat film Tb, in a wet-on-wet state, as shown in FIG. As the second color paint, a polyester-based one-component white urethane paint Tc was air-sprayed from a spray gun 9 to a thickness of 30 to 40 μm.
A white second top coat film Td of m is formed.

Then, the object 1 to be coated on which both top coats Tb and Td have been formed is carried into a dark infrared drying oven 10 whose temperature is set at 120 to 130'C, and for 20 to 30 minutes, both top coats Tb and Td are formed. Baking and hardening Td.

Thereafter, the object 1 to be painted is taken out from the dark infrared drying oven 1o, and after being cooled at room temperature, an adhesive tape 11 is once applied to the separation area 1a of the object 1 to be painted, as shown in FIG. , the first top coat film Tb and the second top coat film W! of the part 1a! Peel off Td.

As a result, as shown in FIG. 8, the red first top coat Tb is formed on one side and the white second top coat Tb is formed on the other side, with the striped base surface of the central painting parting part 1a as the boundary. A coated object 1 on which Td is formed is obtained.

In this example, the explanation was given using a plate-shaped object 1 made of polypropylene resin, but the present invention is not limited to this example, and various shapes of objects can be painted separately. can do.

〔Effect of the invention〕

As explained above, in the method for separately painting synthetic resin products according to the present invention, the surface of the synthetic resin product is subjected to plasma treatment in advance to improve the wettability of the surface and apply the paint for separate application. Since the coating is applied wet-on-wet, it is possible to reduce the number of steps required to bake and harden the coating film.

In addition, in the method for separately painting synthetic resin products according to the present invention, after plasma treatment is performed on the surface of the synthetic resin product, the paint for separately painting is applied. This has the effect of completely eliminating the need for sanding work to improve the adhesion of paint films to each other.

In addition, in the method for separately painting synthetic resin products according to the present invention, since the masking material provided at the separate parts is used in the plasma treatment process, there is no need to worry about paint adhering to the masking material. This has the effect of improving workability.

In addition, in the separate painting method for synthetic resin products according to the present invention, the object to be painted is masked in a band-like manner and no primer is used, so the boundary between the first color paint and the second color paint is It has the effect of adding stripes to the bare surface. .

[Brief explanation of drawings]

FIGS. 1 to 8 are process diagrams of a method for separately painting synthetic resin products according to the present invention. 1 - Object to be painted 1a - Coating division part 2 - - Cleaning tank 6 - Oxygen plasma treatment device 8.9 - Spray gun 10-1 11. Dark infrared drying oven 11 --- 1. Adhesive tape Aa, Ab --- 1. Plasma processing part B ---
- Untreated molecules of plasma a ------1st color paint T c ------1st color paint Applicant Toyota Motor Corporation Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Aa, Ab-plus ゛7 King of Onsen! Totoka Tc-M 2nd color ya r”←

Claims (1)

[Claims] A method of separately painting the surface of a synthetic resin product,
The parts of the synthetic resin product to be painted are masked in advance in a band shape and plasma treated. After removing the masking, the first color paint is applied to one of the plasma treated surfaces using the masked part as a border, and wet-on coating is applied. A second color paint is applied to the other plasma-treated surface in a wet state, the first color paint film and the second color paint film are simultaneously baked and cured, and furthermore, tape is applied to the separation area between the paints. A method for separately painting synthetic resin products, which is characterized by pasting and peeling off the paint film in that area.