JPS6351981A - Formation of multicolor film - Google Patents

Abstract

PURPOSE:To economically form a multicolor film having mica-like appearance by one baking, by changing the thickness of the film composed of mica-base paint formed on a colored substrate. CONSTITUTION:For example, in painting the outer panel of an automobile color intermediate coat based on a thermosetting resin is applied as a colored substrate and mica-base paint containing 0.1-10wt% of mica pigment and having hiding power of 50mum or more is partially applied to the color intermediate coat layer to form a first layer composed of the mica-base paint. Thereafter, masking is detached and a second layer composed of the same mica-base paint as the first layer is applied to the whole without performing baking. When clear paint is applied, if necessary, and baking is performed, the multicolor coating of the desired pattern formed between the mica-base paints and the colored substrate by the film thickness difference of said paints is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a method for forming a multi-colored coating, in particular a method for forming a multi-colored coating, in which a colored base is applied to a surface to be coated, such as an automobile, and then a mica-based coating is applied, which causes differences in film thickness. The present invention relates to a method for obtaining a multicolor coating by coating S in a similar manner.

[Prior Art 1 Multi-color painting of automobiles has conventionally been carried out using a two-tone finish. This can be done by applying a first paint, baking it, masking a part of it, painting it with a second paint of a different tone, and baking it again. However, in such a method, baking is performed twice, resulting in overbaking, which causes problems such as yellowing, a decrease in rJ4 smoothness, and a large step difference at the parting part. Furthermore, it has not been possible to sufficiently satisfy recent demands for diversity in design.

Various '11 proposals have been made to solve these problems. For example, Japanese Patent Application Laid-Open No. 60-58270 discloses a two-tone color coating method, which is characterized in that a two-tone color coating is applied with an intermediate coating, and then the entire surface is coated with a colored transparent or translucent top coating. ing. In detail, after forming the first intermediate coating film and baking,
Part of the ball is masked, a second intermediate coat of paint is applied, and the ball is baked. After that, the masking is removed, a colored transparent or translucent top coat is applied to the entire surface, and baking is performed again.

Furthermore, in JP-A No. 60-118266, a first base layer is formed by coating an object with a first paint color, and a second four-color paint is applied to selected areas on the first base layer. Discloses a two-tone color coating method in which a second base layer is formed by coating an obscuring paint, and clear I and fi are coated on the upper surfaces of the paint films of the first and second base layers as a Vt characteristic. are doing. In this method, a low-hidden paint such as burr mica is used to form the second base layer. This painting method uses three layers: color base, mica base, and clear to create the color.

[Problems to be Solved by the Invention] However, in the method of JP-A-60-58270 mentioned above, since a two-tone color finish is achieved by a color intermediate coating, it is necessary to perform baking twice, which is not economical, and The film thickness of the top coat is uniform, making it impossible to create sufficient variety in design. Also, JP-A-60-11
The method of No. 8266 uses three layers: color base (first base layer), mica base (second base layer), and clear (finishing layer) to create a color, so the color is only partially pearlized. fA-like finish appearance cannot be achieved.

Therefore, the purpose of this light/light is to create a multi-colored coating with an overall mica tone in one baking process! It is an object of the present invention to provide a method that can be used to form the image passively.

[Means for Solving the Problems] In view of the above objectives, the authors of 1. 5, the present invention was conceived based on the fact that the composite color of the color can be changed in various ways.

In other words, the method for forming a multicolored coating of the present invention includes (a) coating a part of the object on which the colored base has been formed with a mica-based paint to form a first mica-based coating; (b) Further, the mica-based paint is further applied over almost the entire surface of the object to be coated to form a second mica-based paint film, and due to the difference in film thickness of the resulting mica-based paint, a composite color with the colored base is formed. It is characterized by changing.

Mica-based paints reflect and scatter transmitted light by mica particles dispersed in the paint, producing a burl-like shine, but when formed on a colored substrate, a composite color is formed with it. It was also found that the composite color changes significantly depending on the thickness of the mica-based coating. Kikomei's method takes advantage of this property and uses it! of mica-based paints. By partially changing the 110 thickness, multicolor mica coating was achieved.

In the method of the present invention, the colored base is 18. For example, color intermediate coatings are used in the painting of automobile exterior panels.

Although color intermediate coatings may be applied directly to the object to be coated, they are usually applied after applying an undercoat (brimer). Undercoating has traditionally been done by electrodeposition, using conventionally known anionic or cationic electrodeposition paints. When using an anionic electrolyte paint, the coating is carried out in water using a separate IIS electrode with the object to be coated as an anode. The opposite is true when using a cadion type electro-aging paint. The film thickness of the electrodeposition coating is usually 15 to 20 .mu.m in dry film thickness, but there is no particular problem in terms of performance, apart from good performance, even if the film is thicker than this.

There are various color intermediate coatings that can be used in the present invention, but those based on thermosetting resins are particularly preferred for automotive coatings.

As the thermosetting resin, alkyd resin, Alfree alkyd resin, acrylic resin, etc. can be used.

Color intermediate paints also contain hardeners, coloring pigments, and solvents. Examples of curing agents for thermosetting resins include melamine trees and polyisocyanates having free NGO groups. The ratio of thermosetting resin and curing agent is 85:
It is preferable to set it as 15-40:60. Regarding coloring pigments, white 11 such as titanium white is used to produce the desired color.
Any pigment can be selected from Ai<, organic or amorphous pigments. Pigment moisture content in paint is generally 5 to 55.
It is preferable to set it to about % by weight. Furthermore, the solvent is used to dissolve the thermosetting resin and improve the dispersibility of the colored pigment, as well as to adjust the viscosity of the paint to improve workability and to improve the finished appearance of the paint film. For these purposes, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, etc. are preferred.

The color intermediate coating is a 20-50 μm film;
Baking is performed at 100-160°C for 10-20 minutes. The resulting intermediate coat is wet-sanded with #600 paper to improve smoothness, if necessary.

Next, masking is applied partially with tape, paper, etc. according to the desired pattern on top of the color intermediate coating. A mica-based paint is applied to this masked colored base.

There are almost a variety of mica-based paints that can be used in the method of the present invention, but in particular pearly white mica, which is made by coating mica with a thin layer of titanium white, and interference color, which has a relatively thick coating of titanium white. Interference mica that emits , colored mica coated with iron oxide, and the like are preferred.

These mica pigments are commercially available from Merck & Co., Marl Inc., Nikki Koken Kogyo Co., Ltd., Teikoku Kako (a), and EM Chemical Company.

The mica-based paint has a hiding power of 50 μm or more in order to produce a clear composite color with the colored base.

If the hiding power is less than 50 μrn, the color change caused by applying a small coat of mica-based paint will be too small, making it impossible to effectively obtain multicolor ψ. However, from a practical point of view, 50 to 150μ
Those having a hiding power of m are preferred.

Furthermore, the mica pigment content in the mica-based paint of the present invention is 0.1 to 10 small ffl+! It is 5. If it is less than 0.1% by weight, the color of the colored base will come out strongly and the effect of mica coating will be insufficient, and if it exceeds 10% by weight, the gloss of mica base 4 < 11 will decrease and the finished appearance will deteriorate. becomes worse.

The preferred mica pigment content is 0.5 to 8% by weight.

The vehicle resin in the mica-based paint may be the same as in the color intermediate paint, and the same additives and solvents for the curing agent can also be used.

'Ii'? Comb to form the first layer of mica-based paint. The dry film thickness of this second layer is 10 to 25 μm, preferably 10 to 15 μm.

After forming the first mica-based coating, the masking is removed and a second layer of mica-based coating is applied without baking. In order to fully achieve the multi-color coating effect, the second layer of mica-based paint is also coated with the same coating as the first layer.
0.1~10! 'I! Mica pigment with a diameter of 96 and 50 μm
It is preferable to have the above hiding power. The second madder coating film formed by this mica-based paint has a thickness of 10 to 25 μm, preferably 10 to 15 μm.

In the masked areas, only the second layer (10 to 25 μm) is formed on the colored base as described above; however, in the unmasked areas, the second layer is This is the second layer (20 to 50 μm). As described above, since the thickness of the mica-based paint film changes depending on the desired pattern, the visual color with the colored base also changes accordingly. As a result, a desired pattern of multicolor coating can be obtained.

After completing the application of mica-based paint, apply clear paint as necessary. The same thermosetting resin and curing agent used for the color intermediate coating can be used for the clear coating. Although it is economical to apply four coats of clear paint to the web 1 on four layers of mica-based paint in an on-wet manner, there is no problem in baking the mica-based paint casually. In either case, the top layer of the clear paint has a baking rate of 1° [Example] Kikomei will be further explained in SF\Il+ based on the following example.

Example 1 A multicolor coating was formed using a colored base and four mica bases under the following conditions.

(1) 4 objects: 0.8 tm x 300 mr x
500 rrrtn'A board.

(2) Before! 18 Coated with diphosphoric acid sub4<7 type surface treatment agent "Granodin 5D-5000" (Nippon Paint (manufactured by Kiki)).

(3) Undercoat: °゛Power Top υ-30'' (manufactured by Nippon Paint) as a cadion electrodeposition paint [g. Dry film thickness 2
Bake at 180°C for 20 minutes.

(4) Color Intermediate coating: Painted with Nippon Paint ■'s "Lega P-2 Blue" (N-6) as an oil-free melamine paint. Bake at 1,10°C for 20 minutes. Dry film thickness 35μrTl.

(5) Painting with mica-based paint: (a) Mica-based paint: Acrylic resin paint containing 5% by weight of Marl's Exualia and Highlight Blue as T-Wataru Blue Mica (Nippon Paint's Super Rack H-12”).

Hiding power 200μm0 (b) First: Attach one stripe of masking tape to the center of the color intermediate coating, place the object to be coated on the conveyor, and apply the above mica-based paint as shown below using a spray gun. Painted under the following conditions.

Spray gun: REA Ki 11 Tsubu N016 Spray gun loss: 2 Spray gun 2 (!M: 30Ca Spray gun stroke = 25 reciprocations/min Paint viscosity: 13
sec/#4 Ford Cup 20'C Discharge ffi: 300cc/min Atomization ■ArjI: 4.5 clauses/ctA Applied voltage knee 60KV Conveyor speed: 4m/min Pattern width: 30cm Film thickness: 10μm (C) Second +f'l: After applying r1 of the -th layer, remove the masking tape and apply the above mica-based paint on wet x 7h using the same method as No.1. Membrane 10. um.

(6) On the second layer of mica base Ill coated with clear 4g1J, apply "Superlac 0-288 Clear" (manufactured by Nippon Paint@l) as an acrylic resin clear paint wet-on-wet. Bake at 140℃ for 20 minutes. Regarding the obtained multicolor coating with a dry film thickness of 35 μm,
Pleochroism (contrast between two colors), PGd value (image clarity)
, gloss, weathering resistance, adhesion and ? N) Impact resistance was measured under the following conditions.

Multicolor PI: Visual judgment.

PGd fri: (t14) Japanese color rjl
Evaluated with PGD-4 type manufactured by Kyusho.

Glossiness: Visual judgment.

Accelerated weather resistance! E: JIS 511006.1740
Expressed by gloss retention room (%) after 0 hours.

Adhesion: JIS 54006.15 Measured by cellophane tape peeling test of 1 board size (1001!). Dimensions expressed by the number of remaining pI orders.

Impact resistance: JIS 54006.13 500g weight and 1/2 diameter Uses a punching type.

Example 2 A multicolor coating was formed under the same conditions as in Example 1, except that the brightness of the "Olga P-2 Blue" paint for color intermediate coating was changed from Toro to N-3, and the same tests were conducted. Ta.

Example 3 A multicolored coating was formed under the same conditions as in Example 1 except that the concentration of mica pigment in the mica-based paint was changed to 10%, and the same test was conducted.

Example 4 In step 5 of Example 1, 20 x 400 nu+ fluorescent 7-beam manufactured by Sumitomo Three M Co., Ltd. was applied to a part of the color intermediate coating film, and in step 6, Superlac M-12 was applied with a hiding power of 200.
A test piece was prepared and tested in the same manner as in Example 1 except that Super Rank 0 28M Clear was applied wet-on-wet in the seventh step.

Comparative Example 1 A multicolor coating was formed under the same conditions as in Example 1 except that the color intermediate coating was made multicolored by masking and a mica base coating was used as one layer, and the same test was conducted.

The test results of Examples 1 to 4 and Comparative Example 1 are shown in Table 1 below.

From the results shown in Table 1, it can be seen that the polychrome 11 formed by the method of the present invention has a deeper color contrast and better coating performance.

Example 5 A multicolor coating was formed under the same conditions as in Example 1 except that the concentration of mica pigment in the mica-based paint and the hiding power were as shown in Table 2 below.

The same tests as in Example 1 were conducted for each multicolor coating. The results are shown in Table 2.

From the results in Table 2, it can be seen that when the mica pigment concentration is in the range of 0.1 to 10% by weight, the color contrast is good.

Example 6 A multicolor coating was formed under the same conditions as in Example 1, except that the film thicknesses of the first, layer, and second layers of the mica-based paint were as shown in Table 3 below, and the same tests were conducted. Ta. The results are shown in Table 3.

Table 3 (Note) Sample No. 2 is the same as actual color example 1.

○: Good ×: Bad From the results in Table 3, the film thickness is outside the range of this defense (sample N
It can be seen that O31 and 4) have poor color tone contrast. In addition, for sample No. 011, a +5) color contrast could not be obtained even if the concentration of mica pigment 4 was made higher than 5% by weight, and for sample No. 014, even if the concentration of mica pigment was lower than 5% by weight. The same () did not have a satisfactory tonal contrast.

[Effects of the Invention] The method for forming a multicolor coating of the present invention has the following effects.

(1) Various color contrasts can be easily obtained by using 119 thick coating of mica-based paint.

(2) By attaching colored tape or fluorescent tape to a part of the color intermediate coating to make it multicolored, and then forming a mica coating film with different thicknesses, a coating film with a miserable and complicated design is created. can be obtained.

(3) Since it is multicolored using mica base filE5, the composite color with the colored base cannot be described as a beautiful pearl mica tone.

(4) Since the mica-based paint can be applied wet-on-wet over the color intermediate coating, the number of baking steps can be reduced overall, making it economical.

(5) Due to the above-mentioned features, the method described in this section is particularly effective for aesthetically decorating the inner and outer panels of an automatic.

Claims (7)

[Claims] (1) (a) Apply a mica-based paint to a part of the object on which the colored base has been formed to form a first mica-based coating, and (b) further cover almost the entire surface of the object. A multicolor product characterized in that the mica-based paint is applied over and over again to form a second mica-based paint film, and the composite color with the colored base is changed depending on the difference in film thickness of the resulting mica-based paint film. Method of forming the coating. (2) The method for forming a multicolored coating according to claim 1, characterized in that the mica-based paint contains 0.1 to 10% by weight of mica pigment and has a hiding power of 50 μm or more. How to do it. (3) In the method for forming a multicolor coating according to claim 1 or 2, the first mica-based coating film and the second mica-based coating film each have a thickness of 10 to 25 μm.
A method characterized by having a dry film thickness of m. (4) The method for forming a multicolored coating according to any one of claims 1 to 3, further comprising applying a clear paint. (5) In the method for forming a multicolor coating according to any one of claims 1 to 4, the second mica-based coating film is applied wet-on-wet onto the first mica-based coating film. A method characterized by forming. (6) The method for forming a multicolored coating according to any one of claims 1 to 5, wherein the colored base is a colored tape or fluorescent tape attached to a part of the colored coating film. A method characterized in that (7) In the method for forming a multicolor coating according to any one of claims 4 to 6, the clear paint is applied wet-on-wet on the second mica-based coating film. A method characterized by: