JPH0632771B2 - Metallic finishing method - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a metallurgical finishing method, and more specifically, by using a mica flakes pigment and a graphite as a metallurgical pigment in combination, a flake-like mica flakes pigment is obtained. The pearly luster and the metallic luster of the scaly graphite interfere with each other, and in combination with the original color tone of the coating, it is possible to form a metallic coating with a unique metallic feel that is excellent in cosmetics. Regarding finishing method.

2. Description of the Related Art Metallic coatings have a variety of variations in combination with the various color tones of the coating, because the incident light from the outside is reflected on the scaly metallic pigment contained in the coating to make it glitter. It has a uniquely beautiful appearance and is often used on the outer panels of automobiles and motorcycles. As a method for forming such a metallized coating film, (i) a metallic coating material containing a metallic pigment is directly applied to the surface of an object to be coated or on the surface of a cured intermediate coating film, and the coating is heat-cured 1 coat 1 Baking method (1C1B); (ii) Metallic paint is applied, which is heat-cured, and clear paint that forms a transparent coating film is applied repeatedly, and heat-cured again 2 coats 2
Bake method (2C2B); (iii) Two-coat one-bake method (2C1B), in which the metallic paint and the clear paint are applied in the above-mentioned order to cure both coatings simultaneously by one heating;
The 3 coat 2 bake method (3 Bake method in which clear coating is further applied to the coating surface formed by C1B and heat curing is performed again (3
C2B) etc. are known.
The metallurgical finishing method according to 2C1B of (iii) above is most often adopted, after comprehensively judging the finished metalic appearance, coating film performance and the like.

On the other hand, a metallic coating that exhibits a uniform metallic feel without unevenness of metal and has excellent gloss and sharpness is a rule that the scaly metallic pigment is parallel to the coated surface and uniformly over the entire coated object. It is said that the metallized paint itself is formed due to its excellent smoothness of the coated surface itself. The reflected light of the metallic coating that satisfies these requirements is a mixture of the specific color light that has been selectively absorbed and returned from the coloring pigment contained in the coating, and the light reflected by the metallic pigment. Since a phenomenon of interference occurs between these two kinds of light, the structure of the reflected light is considerably different depending on the amount of incident light and the angle of reflection of the metalic coating film, and a variety of glitters are shown.

Mica flakes particle pigment, which is conventionally known as a metallic pigment (hereinafter sometimes referred to as "pearl mica pigment")
Has a peculiar pearly luster due to the difference between the high refractive index of titanium oxide or iron oxide coating the surface of mica and the refractive index of mica. .

On the other hand, in the metallic finish by 2C1B, it is important to improve the hidden payability of the base coat in order to improve the efficiency in the metallic finish.
For that purpose, a method of improving the hidden pay property by increasing the proportion of the pearl mica pigment in the base coat coating film or by using a pigment excellent in the hidden pay property, for example, a pigment such as carbon black is generally used. Has been adopted.

However, increasing the proportion of the pearl mica pigment is not preferable because it causes a decrease in gloss in the finished state of the coating film and a fluffy skin surface, and also has the drawback of reducing the durability of the coating film.

On the other hand, improving the hidden paying property by using carbon black or the like has a problem that the pearly luster of the pearl mica pigment is lowered and the color tone of the coating film is darkened. It has the drawback that it can only be applied to the color of the coating.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In view of the above-mentioned circumstances, the present invention does not impair the pearly luster of the pearl mica pigment as much as possible, and does not reduce the color tone of the coating film as much as possible, and the good concealing pay is obtained. The purpose is to obtain a coating film.

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention can solve the problems by using pearl mica pigment and scaly graphite as a metallic pigment. The present invention has been completed and the present invention has been completed.

Thus, according to the present invention, after a thermosetting base coat paint containing a metalic pigment is applied, a thermosetting topcoat paint containing no pigment is applied repeatedly, and both coating films are heated and cured at the same time. In the above method, a pearl mica pigment coated with titanium oxide and / or iron oxide is used in combination as a metallic pigment in the base coat paint, and a graphite particle is used in combination.

In the present invention, when the metalic base coat paint is applied and cured, the light incident on the metalic coating film has a high refractive index of the fine particle titanium oxide or iron oxide coated on the surface of the pearl mica pigment and the light passability of mica. Emits a pearly luster, while the flaky grafitite pigment produces a unique metallic luster. The light of the two interferes with each other to form a coating film having a unique pearly metallic feel excellent in aesthetic properties, which is varied in combination with various color tones of the coating film.

Furthermore, in a metallic coating containing a pearl mica pigment, the pearl mica pigment exhibits a unique pearly luster due to the difference between the high refractive index of titanium oxide or iron oxide coated on the surface of the mica and the refractive index of the mica. As a result, the hiding payability of pearl mica pigments is generally inferior. Therefore, carbon black may be added for the purpose of improving the hidden pay property, but it is better to use the pearl mica pigment and the graphite together as in the present invention when the hidden black property is improved by adding the carbon black. In comparison, the same lightness coating has much better hidden payability.

The paints used in the present invention and the metalic coating finishing method using them will be described in more detail below.

(1) Thermosetting paint containing metallic pigment This paint is a thermosetting paint containing metalic pigment, which is a known thermosetting paint (hereinafter sometimes referred to as "metalic base coat"), and more specifically thermosetting. Of the present invention is a paint comprising a resin composition, a metallic pigment and an organic solvent as main components, and if necessary, a color pigment, an extender pigment, a viscosity modifier, a coating surface modifier and the like. As the thermosetting resin composition, for example, a base resin selected from alkyd resins, polyester resins, acrylic resins, cellulosic resins and the like, and a cross-linking agent selected from amino resins, isocyanate resins (including blocked ones), etc. Are preferably used, and these base resins and crosslinking agents are
Those known per se can be used. The form of the metallic base coat is preferably an organic solvent solution type or a non-aqueous dispersion type.

Further, as the metallic pigment, pearl mica pigment coated with titanium oxide and / or iron oxide and scaly graphite are used in combination.

The amount of the pearl mica pigment is preferably 1 to 20 parts by weight and the amount of graphite is preferably 1 to 40 parts by weight per 100 parts by weight of the solid content of the thermosetting resin composition. The relative ratio of pearl mica pigment and graphite is arbitrary, but the ratio of pearl mica pigment / graphite is usually 1/9 to 9/1, preferably 1/3 to 3/1.
It is suitable to be within the range.

The total amount of pearl mica pigment and graphite per 100 parts by weight of the solid content of the thermosetting resin composition is 2 to 50.
Within the range of parts by weight is desirable.

The pearl mica pigment particles used are those having a longitudinal dimension of about 5 to 60 microns and a thickness of about 0.25 to 1 micron. The titanium oxide and / or iron oxide layer comprises about 10-85% by weight of the total weight of the particles.

In the present invention, the metalic base coat can be directly applied to an object to be coated, but a primer such as a conventionally known electrodeposition paint (anion type, cation type) and a thermosetting intermediate coating paint are applied, It is preferable to apply the coating after curing the coating. As the coating machine, it is preferable to use an atomization type coating machine, for example, an air spray coating machine, an air spray coating machine and an air atomization type or rotary electrostatic coating machine, and the like. It is preferable to adjust within 10 to 40 seconds, particularly 11 to 20 seconds (20 ° C.) with the forward cup # 4, and the coating film thickness is generally 2 to 30 μm based on the heat-cured film thickness, especially 5 A range of up to 25 μ is suitable.

In the present invention, a pigment-free thermosetting topcoat paint is applied after the above metal base coat is applied. The top coating material is not particularly limited and may be a transparent coating material composed of the same resin component as that of the metallic base coat, and the form of the coating material is preferably an organic solution type or a non-aqueous dispersion type.

Action and effect In the metallic coating thus finished, since the metallic pigment is composed of pearl mica pigment and scaly graphite, externally incident light gives a pearly luster in the pearl mica pigment, while Flake graphite pigment gives a unique metallic luster.

And the light of these two interferes with each other, the pearly luster of the pearl mica pigment shows a more diverse glitter, and it is a unique pearl-like metallic with a rich sense of variation and a deep feeling. The finish is obtained.

Further, since the coating film formed by the method of the present invention has a good concealing paying property, it is possible to easily apply a paint having a color having a higher lightness than the conventional one.

EXAMPLES Hereinafter, the present invention will be described more specifically by way of examples.
In addition, a part and% show a weight part and weight%.

Production Example 1 of Metallic Base Coat Styrene 15%, methyl methacrylate 15%, butyl methacrylate 40%, 2-ethylhexyl acrylate 13%, hydroxyethyl methacrylate 15
% And acrylic acid 2% are copolymerized in a xylol using a polymerization initiator asobisisobutyronitrile, and an acrylic resin solution having a heating residue of 50%, a solution acid value of 80, a solution viscosity of Y (Gardner, 25 ° C.) AC-1 was obtained.

Using this acrylic resin solution AC-1, two types of metallic base coats were prepared with the following composition.

In the production, each component was mixed and dispersed, and then a mixed solvent consisting of 35 parts of ethyl acetate, 35 parts of toluene, 10 parts of isobutanol, and 20 parts of Swazol 1000 (manufactured by Maruzen Petroleum Co., Ltd.) had a viscosity of 14 seconds (Food Cup # 4/20. C) was adjusted.

Production Example 2 of Metallic Base Coat Two types of metallic base coats were prepared in the same manner as in Production Example 1 with the following composition.

Production Example 1 of Topcoat 50% AC-1 used in the production of metalic base coat
140 parts and 55% melamine formaldehyde resin 50
Was used to prepare a top coat in the same manner as in Metallic base coat production example 1.

Example 1 A polybutadiene-based electrodeposition coating was electrodeposited on a 0.8 mm-thick dull copper plate that had been subjected to zinc phosphate chemical conversion treatment to a dry coating film thickness of about 20 .mu.m, and baked at 170.degree. C. for 20 minutes.
Sharpen with 0 sandpaper and wipe with petroleum benzine to degrease. Then, an intermediate coating surf ace for automobiles is air-spray coated so that a dry coating film has a thickness of about 25 μm, baked at 140 ° C. for 30 minutes, sanded with # 400 sandpaper, drained and dried. Then, degreasing with petroleum benzine is used as the material for the test.

On top of that, the metallic base coat obtained in the above production example 1-
Each of A and 1-B was dried with an air spray gun (Wider # 71 manufactured by Iwata Coating Machine Co., Ltd.) to a dry film thickness of 10 to 2
The coating solution was applied so as to have a thickness of 0 .mu.m and left at room temperature for 5 minutes.
Apply by air spray so that Then, after leaving it at room temperature for 10 minutes, it is heated at 140 ° C x 30 with an electric hot air dryer.
A heat-cured metallized coating film was formed for a minute.

Comparative Example 1 In Example 1, the metallic base coat 1-A, 1
Metallic base coat 2-A, 2-B instead of -B
A metallic coating film was formed in the same manner except that each of the above was used.

The metallized coating films obtained in Example 1 and Comparative Example 1 were measured with a self-recording spectroscope Macbeth MS-2020 manufactured by Macbeth Co., Ltd. under measurement conditions including C light source and specular reflection light (SCI).
The spectral reflectance was measured to determine L, a, and b.

The results are shown in Table 1 below.

Further, the metallic base coats 1-A, 1-B and 2-
Table 2 below shows the results of visually measuring the hidden pay thicknesses of A and 2-B using black and white hidden pay paper under the condition of complete hidden pay.

Further, FIG. 1 shows the results in which the relationship between the L value of the metallic coating and the hidden pay film thickness of the metallic base coat is summarized from Table-1 and Table-2. It is clear from FIG. 1 that in Example 1, a metallized coating film having the same hidden pay film thickness and a high L value as in Comparative Example 1 was obtained.

The coating films 1-A and 1-B obtained in Example 1 and the metallic coating films 2-A and 2-B obtained in Comparative Example 1 were manufactured by Jonan Seisakusho Co., Ltd. Microscopic gloss meter JSL-11. 2 to 5 show the results of measuring the luster sensation according to, and the microscopic gloss values calculated from the results are shown in Tables 3 to 6 below.

Here, the measurement with the microscopic gloss meter will be described below.

(1) Microscopic glossmeter The microscopic glossmeter was developed to measure qualitative differences such as gloss of silk and gloss of cotton. It is a gloss meter that measures minute parts that cannot be measured.

In other words, the microscatter based on the distribution of the reflection characteristics from the part of the size of the sample surface where the resolution of the naked eye becomes a problem.
It captures opic optical properties. This model was used for the measurement of glitter.

(2) Principle Light is incident on the sample surface from a specific direction, and the reflected light is received by the objective lens to form a magnified image of the sample surface. The image plane is scanned with a light receiver having a small slit, and the amount of light received is recorded.

(3) Resolution, magnification The numbers in parentheses are the experimental values. Objective lens magnification M (× 11.1), scanning speed asm / min (2),
When the feeding speed of the recording apparatus is bcm / min (120), it is the mechanical magnification in the scanning direction × b / a (60). Furthermore, if a slit for scanning (0.2 x 1.0 mm) is used, the resolution is in the scanning direction: 0.2 / M (mm) = 0.018 (mm), and the direction perpendicular to the scanning is 1 / M (mm) = 0.090 (mm), so the final magnification is in the scanning direction. : XbM / a = 666 Received light amount: Variable by changing the sensitivity of the photomultiplier tube (450V
(/ 15μA) (4) Photometric conditions From the results of experiments so far, the photometric conditions are (5) Measurement results are shown in Table-3 to Table-6.

In the stock table, P: Average value of distance between peaks: Relative reflection light amount of valley h: Relative reflection light amount of mountain Table-3 Calculated microscopic gloss value of the metallic coating 1-A of Example 1 (1): 3.44 h: 5.34 (2): 3.78 h: 5.43 (3): 3.26 h: 8.09 (AVE.): 3.50 h: 6.29 (AVE.h-AVE.) = 2.75 PITCH (P): 0.271mm Table-4 Implementation Calculated Microscopic Gloss of Metallic Coating 1-B of Example 1 (1): 7.32 h: 18.36 (2): 10.74 h: 14.13 (3): 6.10 h: 9.54 (4): 6.05 h: 9.67 (5): 7.85 h: 13.21 (6): 7.94 h: 10.68 (7): 7.55 h: 10.73 (AVE.): 7.65 h: 12.33 (AVE.h-AVE.) = 4.68 PITCH (P): 0.184 mm Table-5 Comparison Calculated Microscopic Gloss of Metallic Coating 2-A of Example 1 (1): 3.63 h: 6.42 (2): 3.65 h: 6.89 (3): 5.14 h: 6.91 (4): 4.00 h: 9.07 (5): 4.64 h: 6.16 (6): 3.81 h: 9.25 (7): 3.09 h: 5.38 (AVE.): 3.99 h: 7.15 (AVE.h-AVE.) = 3.16 PITCH (P): 0.167mm Table-6 Comparison Metallic coating 2 of Example 1 -Calculated value of microscopic gloss of B (1): 13.32 h: 20.32 (2): 16.52 h: 19.83 (3): 11.20 h: 17.68 (4): 14.23 h: 17.36 (5): 15.41 h: 18.84 (6) : 14.81 h: 17.73 (7): 14.59 h: 17.27 (8): 14.41 h: 18.30 (9): 14.48 h: 16.90 (10): 13.33 h: 18.43 (11): 13.73 h: 19.18 (12): 16.01 h: 19.72 (13): 14.58 h: 17.46 (14): 15.86 h: 18.56 (15): 14.02 h: 18.77 (16): 11.78 h: 14.64 (17): 11.31 h: 26.18 (AVE.): 14.09 h : 18.66 (AVE.h-AVE.) = 4.75 PITCH (P): 0.076 mm From these results, the metallic particles 1-A, 1- of Example 1 were obtained.
B is larger than the metallic coating film of Comparative Example 1, 2-A and 2-B, and the distance between the peaks of the radiance is large, so that each radiance is not disturbed by the adjacent radiance. It is clear that an excellent coating film can be obtained.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the L value of the metallic coating and the hidden pay film thickness of the metallic base coat.
FIG. 5 shows the metallic coating films 1-A and 1-B of Example 1 and the metallic coating films 2-A and 2 of Comparative Example 1, respectively.
It is a chart showing the microscopic gloss of -B.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Hirayama 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Kansai Paint Co., Ltd. (72) Inventor Yutaka Masuda 4--17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture Nishi Paint Co., Ltd. (72) Inventor Miyoshi Takeuchi 4-1-1 Higashi-Hachiman, Hiratsuka City, Kanagawa Kansai Paint Co., Ltd. (56) Reference JP-A-60-118267 (JP, A) JP-A-59- 62372 (JP, A) JP-A-57-65354 (JP, A) JP-A-56-25448 (JP, A) JP-A-52-81351 (JP, A)

Claims (2)

[Claims] 1. A metallurgical finishing method comprising coating a thermosetting base coat paint containing a metalic pigment, coating a thermosetting topcoat paint not containing a pigment, and heating and curing both coating films at the same time. A metalic finishing method, wherein mica flakes particles coated with titanium oxide and / or iron oxide and graphite particles are used in combination as a metallic pigment in a base coat paint. 2. The base coating composition according to claim 1, wherein 1 to 20 parts by weight of mica flakes and 1 to 40 parts by weight of graphite particles are used in combination with 100 parts by weight of resin solids in the base coating composition. Metallic finishing method.