JPS62110781A - Formation of remedial coated film - Google Patents

Abstract

PURPOSE:To smoothly join an old coated film and a remedial coated film by forming the remedial first improvement base coated film and the remedial second base coated film on the first base coated film at the part to be remedied and then forming a clear coated film. CONSTITUTION:The first base coated film 2 is formed with a colored paint, the second base coated film 3 is formed thereon by weakly masking coating, and further a clear coated film 4 is formed thereon by a clear paint. When the coated film is partially remedied, the remedial first improvement base coated film 2'' is formed on the first base coated films 2 and 2' at the part to be remedied with the mixed paint of a colored paint and a weakly masking paint, the remedial second base coated film 3' is formed by the weakly masking paint or the weakly masking paint added with a clear paint, and then a remedial clear coated film 4' is formed with a clear paint. Consequently, the coloring from the remedial coated film is equalized to the coloring from the old coated film, and the old coated film and the remedial coated film are smoothly joined.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for partially repairing a paint film. More specifically, it relates to a method for partially repairing a paint film formed by forming a paint film with weak hiding power on a colored paint film, which is formed by a weakly hiding paint containing a pearlescent pigment or a titanized mica pigment. .

<Prior art> Paint films containing pearlescent pigments are known to have a high design effect due to the multiple reflection of light by the pearlescent pigments, but due to their weak hiding power, Partial repairs required a unique method.

One of the known repair methods is the one shown in FIG. 6, which is a cross-sectional view of the paint film.

In this coating film, a first base coating film (102) is formed on the surface of a substrate (101) using a colored paint, and a second base coating film (102) is formed on the surface of the base coating film using a weakly hiding paint having a pearlescent pigment.
A base coating film (103) is formed, and finally, a clear coating film (104) is formed. To repair this paint film, first polish an area slightly larger than the area to be repaired, and then □ then this polished surface (^)
The first unbase coating film (102) and the second base coating film (103)
),! : At the boundary (It) -, E, the first base coating film (10
2) Form '. Furthermore, this first base coating film (1
02) Apply a second Heath coating (103) on the surface of ' with the same paint as the weak hiding paint of the old coating, and apply a coating film thickness of the second Heath coating (103) on the polished surface (8). Form to the same extent.

Finally, a clear coating +19 (104) was applied to partially repair the area.

According to this repair method, a base coating film for repair (102)
'(103)', the layer thickness of the second base coating film (103)' made of a paint with a concealing property is the same as that of the base coating films (102) and (103) of the old coating film.

As a result, the amount of light passing through and the amount of multiple reflection of light in the second base coating film (+02) (102)'' are the same before and after repair, and the second base coating film containing pearlescent pigment etc. It is possible to partially repair the paint film without changing the brilliance, which is the design feature of the film (102) (102) '. ) and the second Heath coating (103
), the first Heath coating film for repair (102)' and the second
It becomes difficult to match the color at the boundary (B) with the Hose paint film (103)', and products that require partial repair on the market (
For example, it was difficult to put it into practical use in automobiles).

Therefore, the repair method shown in FIG.
It is proposed as No. 5. This repair method is for partially repairing a coating film having a film structure similar to that of the conventional example described above, and polishing is also performed in the same manner as described above. However, in this method, a first heath coating film (102) for repair is formed so as to cover the second base coating film (103) on the polished surface (^), and a second heath coating film is applied on top of the first heath coating film (102). film(
103)' and a clear coating film (1,04).

According to this method, the first heath coating (102) of the old coating
and the second heath (103) are completely covered with the first heath paint (102)' for repair, so the color difference can be made the same at the boundary between the paint films before and after the repair. This eliminates the drawbacks of the conventional example. However, according to this method, the thickness of each base coating film (102)'(103)' near the polished surface (C) becomes smaller, resulting in changes in the amount of light passing through and the amount of multiple reflection of light. There is a possibility that the brightness of the second base coating film (103) may change.

<Problems to be Solved by the Invention> Therefore, the present invention aims at forming a repair coating film, in particular, a weakly concealing coating film (second Hose coating film) containing a pearlescent pigment, etc. ) becomes smaller and the shine of the second base coating changes near the boundary of the repair coating.

Means for Solving the Problems> Thus, the present invention provides a first base coating film (21
(On 21', form the first improved base coating for repair (21IT) with a paint that is a mixture of a colored paint and a weakly opaque paint, and then apply a weakly opaque paint or a paint that is a mixture of a weakly opaque paint and a clear paint. The above problems are solved by providing a method for forming a repair coating film, which comprises forming a second repair base coating film (3)° and then forming a clear coating film (4)°. Note that the clear coating film includes a color clear coating containing a small amount of pigment and dye.

Hereinafter, a method for forming a repair coating film according to the present invention will be explained based on the drawings.

As shown in Figure 1, the structure of this coating film is based on the base (1).
A first base coating film (3) is formed using a colored paint on top, a second base coating film (3) is formed using a weakly hiding paint containing a pearlescent pigment, etc., and a second base coating film (3) is further formed using a clear paint. , a clear coating film (4) is formed.

Each of these old coatings is applied by a conventional spray coating method.

This old paint film (2) (3) (The repaired area of 41 has been polished over a slightly larger area with water-resistant abrasive paper, etc.), and the polished surface (8) has undergone normal repair. Similarly, degreasing, cleaning and drying are performed. In this polishing, first, the entire surface is polished using abrasive paper of 400 to 600 grit as shown in FIG. Then, as shown in Figure 3, the clear coating (4) is transferred to the second Heath coating ().
It is preferable to polish the clear coating film (4) with abrasive paper of 800 to 1500 grit, and then finish polishing the clear coating film (4) with a compound to form a polished surface (^) as shown in Fig. 1.

Then, each repair coating film is formed on this polished surface (It).

First, as shown in FIG. 1, a first base coating film (2) for repair is formed on the polished surface (A).

This coating film (2) 9 is formed of the same colored paint as the first base coating film, and ensures concealment of the polished surface (^).

Next, a first improved Hess coating L21 II for repair is formed on the first base coating 19 (21', l=) for repair.

This coating film (2)' is the first Heath coating film (2) 1 for repair.
It is desirable to form it slightly larger. The paint used for the first improved base coating 1I9(2)Pa for this repair is:
This paint is a mixture of a colored paint similar to the first base paint film (2) and a weakly hiding paint containing a pearlescent pigment, etc. similar to the second base paint film (3), and the mixing ratio is: It may be changed as appropriate depending on the paint color.

Next, a second base coating film (3) for repair is applied to approximately the same size as the first improved base coating T2). A weakly hiding paint containing the same pearlescent pigment as the second base coating (3) is used. Alternatively, a clear paint may be mixed with this weakly hiding paint.

Finally, a large repair clear coating film (4) is formed on the above-mentioned second repair base coating film (3) 1. If necessary, the clear dust part of the repair clear coating film (4)' is blurred (5) using a blurring thinner.

With the above steps, the formation of the repair coating film is completed, and it is sent to the same drying process (baking or forced drying, room temperature drying) as in the conventional method.

The formation of each of the above-mentioned coating films is generally carried out by a so-called wet coating method, in which a flash time of 2 to 5 minutes is allowed each time each coating film is formed, and then the next coating film is formed. . However, when necessary (when work is hindered due to low temperature or high humidity, or when color reproducibility is difficult), in at least one step after each coating film formation step, It is also effective to employ a baking or forced drying process (including a method of accelerating evaporation of the solvent in the paint and hardening the paint film using not only heat but also air flow). One of the advantages of this case is that the colors match more easily than with the wet painting method. Furthermore, if a beautiful pearlescent finish cannot be obtained due to paint properties or film thickness conditions, a beautiful pearlescent finish can be obtained by baking or forced drying the first base coating film (2) for repair. Furthermore, after forming the second base coating film (3) for repair, baking and forced drying may be performed. This makes it possible to stabilize the behavior of the pearlescent pigment (pearl flakes), and even when a clear paint is applied thereon, the pearl flakes do not swim and a beautiful burl effect can be obtained. Therefore, it is desirable to include one or two baking and forced drying steps between each coating film forming step.

Also, when forming a coating film using a paint that dries at room temperature, the same process as that for soft soil may be used. Furthermore, even when drying at room temperature, between each coating film formation process,
Forced drying may also be carried out, thereby achieving the same effect as described above.

Although it is desirable that the paint used for each repair coating be the same as the paint used for the old coating before repair, it does not necessarily have to be completely the same.

In the above explanation, we have described the case where the base was polished up to 11 during repair, but there are cases where the base is not polished up to 11, such as when the scratches on the paint film are shallow. In such a case, as shown in FIG. It is sufficient to sequentially form the second base coating film (3) and the clear coating film (4).

<Example> An embodiment of the present invention will be described below.

- World "L""p" 1 Castle - First, 300 dragons horizontally, 400 dragons vertically, thickness 0.8++n
A mild steel plate consisting of is used as a painted plate, and the coating is subjected to a coating base treatment consisting of degreasing, water washing, chemical treatment, and water washing processes, and the formation of an electrodeposition coating film consisting of each process of electrodeposition coating, water washing, and baking. Let's do it. Then, an intermediate coating film with a dry thickness of 30 μm was formed on the entire surface of the electrodeposited coating film using a thermosetting intermediate coating material under the coating conditions shown in Table 2.

Next, the surface of the above-mentioned coated board is degreased with a degreasing solvent such as petroleum benzene, and then a first base coating film (2) is formed using a colored acrylic enamel paint. The properties of this paint are as shown in Table 1, and under the coating conditions shown in Table 2, the first Hess coating with a dry film of W-30μ (
2) is formed and baked for about 30 minutes in a conventional hot air circulation drying oven whose temperature is adjusted to 150 ± 2°C to harden.

Next, a weakly opaque paint having the physical properties shown in Table 3 is applied under the conditions shown in Table 2 to form a second Hose coating film (3) having an average dry film thickness of 20 μm.

Table 1: Physical properties of colored paints Table 2: Painting conditions: Table 3: Physical properties of weakly concealing paints Next, after a flash time of 2 to 3 minutes, the physical properties shown in Table 4 are applied to the wet surface. A clear paint film (4) having a thickness of 30 μm was formed by applying a clear paint film (4) having a thickness of 30 μm under the conditions shown in Table 2.

Table 4 Physical properties and dilution conditions of clear paint After forming a three-layer coating (21131+41) and allowing a setting time of about 10 minutes, normal hot air circulation drying at a temperature of 150 ± 2°C was carried out. Baking is performed in a furnace for about 30 minutes to evaporate the solvent and harden the coating.

As shown in FIGS. 1 to 3, the polished surface (A
), washed with water, degreased, and dried.

J! LiL Moon' [Kun λ Non] On the above polished surface (^), place the first base for repair and (
2) Form a °. The first base coating film for this repair (2)
°, dilute the paint in Table 1 with thinner (T-65),
The viscosity of the paint was 15 at Ford Cup Th4 (20℃).
This is done by applying the paint adjusted to 100 ms under the coating conditions shown in Table 5, and is approximately the same as the first base coating (2).
It is formed to a slightly larger size. Then, after baking and hardening it by leaving it in a hot air circulation drying oven adjusted to 150 ± 2°C for about 30 minutes, the overmist part of the first base coating (2) was blotted with water using 1000 grit waterproof abrasive paper. The water was removed while pouring.

Table 5 Coating conditions for repair Next, after a flash time of 3 to 5 minutes, the first improved base coating for repair is approximately the same size as the first base coating for repair (2)l. (21” is formed.This coating film (21” is formed.
” is a mixture of the colored paints shown in Table 1 and the weakly hiding paints shown in Table 3 in a ratio of 1:10, and the paint is diluted with paint thinner (T-65) at 20°C. de1
Dry film ■ by diluting to 2 seconds and painting under the conditions shown in Table 5.

It is formed with a thickness of about 5-10μ.

Next, after a flash time of 2 to 3 minutes, the second base coating (3) I for repair is applied to the first improved base coating (2).
Form the area to be approximately the same size as 1+1 or slightly larger. This second repair coating (3) is
The weakly hiding paint shown in Table 3 was diluted with thinner ('l-65) to 13 seconds in Ford Cup 4 (20°C), and
Paint under the conditions shown in the table.

Finally, after forming a large repair clear coating film (4) with the clear paint shown in Table 4, the clear dust part was possesed with blurring thinner (5).

As a result of the above, the painted board on which the repair coating film has been formed,
The film is placed in the aforementioned hot air circulation drying oven and baked for about 30 minutes. As described above, when ten observers visually evaluated the appearance of the repaired coating film of the completed example, 10 out of 10 observed that the boundary between the old coating film and the repaired coating film was No significant difference was observed.

<Test Example> Furthermore, in order to further clarify the advantages of the present invention,
The following test was conducted.

Conditions for one-layer coating - After forming a base (electrodeposition coating film and intermediate coating film) on a coated plate made of mild steel plate, the following coating film is formed. The formation of each coating film is carried out under the same conditions as for the 5'(7)z group in the above-mentioned <Example>.

■ First base coating with colored acrylic enamel paint.

■Second base coating with weak hiding paint.

■ Clear coating film using clear paint.

Here, the film thickness of the second base coating film is 19μ, 15□μ, 1
Five types of samples are prepared, each set at 1μ, 8μ, and 4μ.

After forming a base (electrodeposition coating/coating film and intermediate coating film) on a coated plate made of 11-sided mild steel plate, the following coating film is formed. In addition, the base was formed under the same conditions as in the above-mentioned <Example> -Old Co.L. 11
Trap p-formation is carried out under the same conditions.

■ First base coat of colored acrylic enamel paint.

■ The first improved base coating film is a mixture of colored acrylic enamel paint and weakly hiding paint.

■ @Second base coating film with concealing paint.

■ Clear coating film using clear paint.

Here, the first improved base coating film was kept constant (12μ), and the second and second base coating films were 19μ, 15μ, 11μ, 8μ, 4#.
Create five types of samples set to .・ ゛Material transfer and 1 In the same manner as Sample 1 of the present invention, ■first base coating film, ■first improved base coating film, ■□second base coating film, and □■clear coating film were formed. do.

Here, the second base coating film was kept constant (15μ), and the first
Five types of samples are formed with modified base coatings set at 12μ, lOμ, 8μ, 5μ, and 3μ.

- Test results - 1 layer 11 flowers 1'' - Each of the above samples was subjected to an accelerated weathering test (test method: JIS Z
0230 Color difference display method JIS Z 8730 5.
Color differences due to 19 thickness differences in each sample were determined using the bistimulus value direct reading method, and are shown in the table below.

Results from conventional samples Note: The color difference due to the difference in film thickness was determined using the second base coating film having a film thickness of 19 μm as a reference.

Results for Sample 1 of the Invention Note: The color difference due to the difference in film thickness was determined using the second base coating film having a thickness of 19 μm as a reference.

Results for Sample 2 of the Invention Note: The color difference due to the difference in film thickness was determined using the first improved Hess coating film having a film thickness of 12 μm as a reference.

As is clear from the above test results, when the film thickness changes in conventional samples, the color difference also changes significantly.
Sample 1 of the present invention. In No. 2, the color difference does not change much even if the film thickness changes. Therefore, when forming a repair coating, even if it is impossible to make the thickness of the weakly hiding coating constant due to the conditions for forming the repair coating or the boundary between the old and new coatings, the In the invention, it was confirmed that there is little risk of color difference occurring between the new and old paint films.

One LIs! , J-Ka” process, each of the above samples was measured using a goniophotometer (
Goniophotmeter) (Murakami Color GP2
00) was measured. This test is
This was carried out at the request of Toyo Aluminum Uno, Co., Ltd., Research and Development Headquarters, and Research Institute.The light was obliquely directed at the sample at an incident angle of 45 degrees, and the reflected light was reflected at an acceptance angle of -15 degrees to 75 degrees. Light is received within the range, and the anti-'l-1 (light receiving value) at each receiving angle is
The peak value (relative value when the reflection value at 45 degrees - 0 degrees of the white standard plate is 28.3) is determined by the brightness near the specularly reflected light. The half-width (the width of the reflection angle that is half the peak value) indicates the directionality of the reflected light (the larger the peak value, the brighter the light, and the smaller the half-width, the stronger the directionality).

The results for the conventional sample are shown in FIG. 8, the results for the sample 1 of the present invention are shown in FIG. 11, and the results for the sample 2 of the present invention are shown in FIG. 10.

As a result of the above tests, it was found that when the film thickness changes in the conventional sample, the peak (a) and the half-width change significantly;
In sample 1.2 of the present invention, it was confirmed that the change in peak value and half-value width when the film thickness was changed was small.

Therefore, similar to Test Result 1, in the present invention, the influence of changes in film thickness on light reflection can be reduced, and even if it is impossible to keep the film thickness constant, new and old It has been confirmed that changes in light reflection between coatings can be reduced.

<Effects of the Invention> As shown in the enlarged cross-sectional view of FIG. Membrane (3
) °, the first mixture of colored paint and weakly hiding pigment is
A modified base coating (2)' is present. As a result, even if the layer thickness of the second base coating film (3) 1 for repair becomes thinner near the boundary (C) of the polished surface (^),
Since the improved base coating film +21'' also contains a pearlescent pigment, the thickness of the layer containing the pearlescent pigment etc. is approximately equal to the thickness of the second base coating film (3) before repair.

Moreover, since the first improved Hehs coating L21 IT contains a mixture of colored pigments and pearlescent pigments, the coloring of the first improved Hehs coating L21 IT itself is due to the color development of the first improved Hehs coating only using colored paint; The color development of the second haze containing only pearlescent pigments is similar to that of a coating film where l is +1 < gray.

As a result, near the boundary of Togidashi 111 Giant ^),
Even if the thickness of the second base coating film C11' for repair becomes smaller, this coating [9(3+' and the first improved base coating film (2)
The amount of multiple reflection of light by pearl light tear face 11 combined with 1 is:
There is no change when compared with that of the old second base coating (3),
The color development from the repair paint film can be made equal to the color development from the old paint film, and the old paint film and the repair paint film can be smoothly connected.

<Brief explanation of the drawings> Fig. 1 is a sectional view of a repair coating film formed by the method of one embodiment of the present invention, and Figs. 2 and 3 are the polishing process of repair coating 11 in the same embodiment. FIG. 4 is an enlarged sectional view of the main part of the repair coating film shown in FIG. 1, FIG. 5 is a sectional view of a repair coating film formed according to another embodiment of the present invention, and FIGS. Each figure is a cross-sectional view of a main part of a repair coating film formed by a conventional method, and FIGS. 8 to 10 are characteristic diagrams regarding the peak value and half-width of reflected light for detailed explanation of the present invention. .

(2)... Old first base coating film, (2)°... First Heas coating film for repair, (21"... First improved base coating film for repair, (3)...・Old 2nd base coating film, (3)°・
...Second base coating film for repair, (4)...Old clear coating film, (4)°...Clear coating film for repair.

Claims (1)

[Claims] A first base coating film (2) is formed using a colored paint, a second base coating film (3) is formed using a weakly hiding paint on top of the first base coating film (2), and a clear coating film (4) is further formed using a clear paint on top of this. In a method for partially repairing a painted film, a first improvement for repair is applied on the first base paint film (2) (2)' of the repaired part using a paint that is a mixture of a colored paint and a weakly hiding paint. After forming a base coating film (2)'' and forming a second base coating film (3)' for repair with a weakly hiding paint or a paint with a clear paint added to a weakly hiding paint, a second base coat (3)' for repairing is applied with a clear paint. A method for forming a repair coating film, which comprises forming a clear coating film (4)'.