JP3305023B2 - Pearl-like coating structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pearl-like coating structure, and more particularly, to a novel pearl-like coating structure capable of imparting a pearl-like effect using a color base coat that does not use any pearl pigment. It is about.

[0002]

2. Description of the Related Art Conventionally, a pearly paint finish is performed by applying an undercoating film to an object to be coated as necessary, then applying a color base coat thereon, heating and curing, and then applying a base coat. A base coat containing a pearl-based pigment is applied thereto, and a clear coat is further applied in an uncured state, and both coats are simultaneously heated and cured, that is, a so-called three-coat two-bake method is used.

[0003] Of course, passenger cars, motorcycles and the like finished in a pearly tone using this coating method have no particular problem in the finishing itself, and have been well received in the market.

[0004]

However, the conventional coating method requires three coats for the coating process except for the undercoat.
The bake method is used, and it is desired to simplify the coating process from the viewpoint of productivity.Because pearl pigments are expensive and the coating cost is high, the same pearl finish is used without using pearl pigments. There is a strong need in the art to develop a coating structure that enables it.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have oxidized aluminum powder pigment to a color base coat used in the conventional pearl paint finishing process. By containing a pigment component in which a titanium pigment is mixed in a specific ratio,
It has been found that one of the three coating steps can be omitted, and that a pearl-like finish coating structure similar to the conventional finish can be obtained, thereby completing the present invention.

Thus, according to the present invention, an aluminum powder pigment (a) having an average particle size of 10 to 25 μm and a titanium oxide pigment (b) are coated on the surface of the substrate with 100 parts by weight of (a) (b). A) a pearl-like coating structure comprising a color base coat layer containing a pigment component mixed in a ratio of 10 to 600 parts by weight, and a clear coat layer laminated thereon.

[0007] The material to be coated used to form the pearly coating film structure of the present invention is not limited as long as it can be coated, and specifically includes automobiles, motorcycles, scooters, appliances for home appliances, and the like. Metal or plastic outer plate used for the above. These materials to be coated may have conventionally known chemical conversion treatments on their surfaces, if necessary.
An undercoat may be applied.

In the present invention, the color base coat layer comprises:
A specific mixture of an aluminum powder pigment and a titanium oxide pigment as an essential pigment component as a pigment imparting a pearl effect,
In addition to the pigments, the pigments include achromatic pigments and / or chromatic pigments commonly used for coloring. As a binder resin other than the pigment component, for example, a thermosetting resin such as an alkyd resin, an oil-free alkyd resin, and an acrylic resin is used, and as a curing agent component of these resins, an amino resin, a polyisocyanate, or the like is used. As the solvent, an aliphatic hydrocarbon, an aromatic hydrocarbon, a ketone, an ester, or the like can be used.

The ratio of the aluminum powder pigment for imparting a pearl effect and the titanium oxide pigment used in the color base coat layer is 10 to 600 parts by weight, preferably 20 to 3 parts by weight, per 100 parts by weight of the former.
It is in the range of 50 parts by weight. When the latter titanium oxide pigment is 10
If the amount is less than 600 parts by weight or less than 600 parts by weight, it is impossible to obtain a pearl-like effect.

The blending of the aluminum powder pigment in the above-mentioned mixed pigment into the color base coat layer is from 1 to 20 PH.
R, preferably 2 to 15 PHR. Outside this range, a suitable pearl effect cannot be obtained.

The color base coat layer in the present invention can be colored to a desired hue by using a coloring pigment in addition to the above-mentioned aluminum powder pigment and titanium oxide pigment.

In the present invention, the L value of the coating structure imparting the pearl effect and the average particle size of the aluminum powder pigment used in the color base coat layer have a considerable effect on the impartation of the pearl effect. For example, in the case of a coating film having an L value of 25 to 65, the average particle size of the aluminum powder pigment is 10 to 15 μm.
It is preferable to use a material having a relatively small particle size, and a material having a relatively large particle size of 15 to 20 μm when the L value is 45 to 85. Further, when the L value is in the range of 55 to 95, the average particle size of the aluminum powder pigment is 20 to 25.
It is preferable to use a material as large as μm.

Here, the L value means a lightness index in the Hunter's color difference equation obtained from the tristimulus values X, Y, Z specified in JIS 28722.

The hue of the color base coat layer is not particularly limited, but it tends to be generally difficult to obtain a pearl-like effect with a hue such as red or yellow. However, even in these hues, when the Munsell chroma is 14 or less, the effect of the present invention can be expected.

Next, as the clear coat layer, a transparent clear paint composed of a vehicle component excluding the pigment component of the above-mentioned color base coat layer or a transparent color pigment is added thereto.
A color clear coating compounded below PHR is used.
Further, a pearl pigment can be blended with the transparent clear paint within a range that does not impair the transparency.

The color base coat layer and the clear coat layer are formed by first coating the color base coat so as to have a dry film thickness of 20 to 40 μm, and then applying a clear coat thereon in an uncured state to a dry film thickness of 20 to 40 μm. 40μ
m, and both coats are simultaneously heated and cured by a two-coat one-bake method. Needless to say, it may be formed by a two-coat two-bake method. As a coating method, ordinary coating means such as air spray coating and electrostatic coating are used. Heat curing of the coating film is 7
The heating is performed at 0 to 140 ° C. for 20 to 30 minutes.

[0017]

The pearlescent coating structure obtained according to the present invention can be obtained by using a specific combination of an aluminum powder pigment and a titanium oxide pigment without using any pearl pigment.
By defining the L value of the coating film and the average particle size of the aluminum pigment, a finish similar to the conventional pearl-like finish can be more suitably given to an automobile, a motorcycle and the like. This can also be understood from the reflection curve diagrams obtained by using a goniospectrophotometer for the conventional pearl-finished coating film and the coating film structure obtained by the present invention.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments. “Parts” indicates “parts by weight”.

Example 1 The following color base coat is spray-coated on a steel sheet which has been subjected to a surface treatment so as to have a thickness (dry film thickness, the same applies hereinafter) of 30 μm. Next, a clear coat described below is applied on the coating film by a wet-on-wet method to a thickness of 30 μm and cured by heating at 70 ° C. for 30 minutes. The coating structure thus obtained has a pearl-like effect, and a goniospectrophotometer (GONIO-Spectro manufactured by Murakami Colors Co., Ltd.) of this coating structure
FIG. 1 shows a reflection curve obtained using a photometer.

76.0 parts of “Retan PG-60 No. 519 Metallic Base ⁽¹⁾ ” containing a color base coat (“Rethane PG” is an acrylic resin paint manufactured by Kansai Paint Co., Ltd.) -110 2.8 parts Urethane PG-60 No.400 black 5.7 parts Urethane PG-60 No.132 White ⁽²⁾ 4.0 parts ─────────────────────── 10 Total 100.0 parts ⁽¹⁾ Main agent / curing agent blending ratio (weight): 100/10
(Same as the following examples) Aluminum powder pigment (manufactured by Toyo Aluminum Co.) Content: 9PHR Aluminum powder pigment Average particle size: 10 to 15 μm ⁽²⁾ Using titanium oxide pigment manufactured by Teica ^(the same applies to the following examples) Oxidation Titanium / aluminum pigment blending ratio (weight): 28 /
100 ⁽³⁾ L value of the coating film: 53 clear coat blended urethane PG-60 top coat clear 100.0
FIG. 1 shows a pearl coating color using only a pearl pigment, a metallic paint using only an aluminum pigment, and a coating film structure of the present invention using a goniospectrophotometer. It is a plot of angle and hue. The structure of the pearl-like coating film of Example 1 is close to the curve of the pearl coating color using only the pearl pigment, and it can be confirmed from visual evaluation that the pearl-like finish is obtained.

The pearl coating color was prepared by replacing the aluminum powder pigment in the metallic base of the color base coat with a pearl pigment (Pearl mica “Iliodin 111 Pearl” manufactured by Merck) and using a ethane PG-60N.
o.132 excluding white. Similarly, the metallic paint color was changed from the color base coat formulation to the urethane PG-
60 No. 132 excluding white.

Example 2 A pearly coating film was obtained in the same manner as in Example 1 except that the following color base coat was used. From FIG. 2, the same effect as in the first embodiment can be confirmed. The pearl coating color and the metallic coating color were prepared in the same manner as in Example 1.

Color base coat blended polyurethane PG-60 No.519 Metallic base 36.0 parts Urethane PG-60 No.400 black 54.1 parts Lethanum PG-60 No.132 white 9.9 parts ───────────── 10 Total 100.0 parts Aluminum pigment content: 2 PHR Aluminum pigment average particle size: 10 to 15 μm Titanium oxide / aluminum pigment: 300/100 L value of: 35 Example 3 Example 1 except that the following color base coat was used.
A pearl-like coating film was obtained in the same manner as described above. FIG. 3 shows the same effect as in the first embodiment. The pearl coating color and the metallic coating color were prepared in the same manner as in Example 1.

Color base coat blended polyurethane PG-60 No.762 base coat 72.5 parts Urethane PG-60 No.132 white 27.5 parts ──────────────────────── 10 Total 100.0 parts Aluminum pigment content: 12 PHR Aluminum pigment average particle size: 15 to 20 μm Titanium oxide / aluminum pigment: 150/100 L value of coating: 74 Example 4 Example 1 except that a base coat was used
A pearl-like coating film was obtained in the same manner as described above. From FIG. 4, the same effect as in the first embodiment can be confirmed. The pearl coating color and the metallic coating color were prepared in the same manner as in Example 1.

57.0 parts of a color base coat blended ethane PG-60 No. 568 base coat 43.0 parts of a ethane PG-60 No. 132 white 10 Total 100.0 parts Aluminum pigment content: 6 PHR Aluminum pigment average particle diameter: 20 to 25 μm Titanium oxide / aluminum pigment: 500/100 L value of coating film: 89

[Brief description of the drawings]

FIG. 1 is a reflection curve diagram of a pearly finish coating film formed according to Example 1, a conventional pearly finish coating film, and a metallic coating film measured by a goniospectrophotometer.

FIG. 2 is a reflection curve diagram obtained by measuring a pearl-like finish coating film, a conventional pearl-like finish coating film, and a metallic paint film formed by Example 2 with a goniospectrophotometer.

FIG. 3 is a reflection curve diagram of a pearly finish coating film formed according to Example 3, a conventional pearly finish coating film, and a metallic coating film measured by a goniospectrophotometer.

FIG. 4 is a reflection curve diagram obtained by measuring a pearly finish coating film, a conventional pearly finish coating film, and a metallic coating film formed by Example 4 with a goniospectrophotometer.

Continuation of the front page (56) References JP-A-4-214779 (JP, A) JP-A-1-11170 (JP, A) JP-A-2-132171 (JP, A) JP-A-2-245072 (JP, A) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 5/06 101 B32B 27/20 B32B 33/00 B32B 27/00

Claims (5)

(57) [Claims] An average particle size of 10 to 25 μm is applied to the surface of a substrate.
m of the aluminum powder pigment (a) and the titanium oxide pigment (b) were added to (b) 10 to 60 with respect to 100 parts by weight of (a).
A color base coat layer containing a pigment component having a mixing ratio of 0 parts by weight and containing 2 to 15 PHR of an aluminum powder pigment (a), and a clear coat layer laminated thereon. Characteristic pearl-like coating structure. 2. The color base coat layer having an average particle size of 1
A titanium oxide pigment (b) is mixed at a ratio of 10 to 600 parts by weight with respect to 100 parts by weight of an aluminum powder pigment (a) of 0 to 15 μm, and a blending amount of the aluminum powder pigment (a) is 2 to 15 PHR. The pearl-like coating film structure according to claim 1, wherein the coating film contains a pigment component represented by formula (1) and has a L value of 25 to 65. 3. The color base coat layer having an average particle size of 1
A titanium oxide pigment (b) is mixed at a ratio of 10 to 600 parts by weight with respect to 100 parts by weight of an aluminum powder pigment (a) having a size of 5 to 20 μm, and a blending amount of the aluminum powder pigment (a) is 2 to 15 PHR. The pearl-like coating film structure according to claim 1, wherein the coating film contains a pigment component having the following formula and has an L value of 45 to 85. 4. The color base coat layer having an average particle size of 2
A titanium oxide pigment (b) is mixed at a ratio of 10 to 600 parts by weight with respect to 100 parts by weight of an aluminum powder pigment (a) of 0 to 25 μm, and a blending amount of the aluminum powder pigment (a) is 2 to 15 PHR. The pearl-like coating film structure according to claim 1, wherein the coating film contains a pigment component of the formula (1) and has a L value of 55 to 95. 5. The pearlescent coating structure according to claim 1, wherein both the color base coat layer and the clear coat layer are formed by two coats and one bake coating.