JPH03143575A - Formation of coated film - Google Patents

Abstract

PURPOSE:To lessen the change in painting colors by a fluctuation in film thickness by successively laminating a colored coated film layer, an interference mica-contg. base layer which contains coloring pigments, has specific color difference from the colored coated film layer and has >=100mum thickness and a clear layer on a base body. CONSTITUTION:The three layers; the colored coated film layer, the interference mica-contg. base layer which contains the coloring pigments in the paint, has >=100mum hiding film thickness of the cured coated film and in which the painting color at the hiding film thickness of the cured coated film is <=3.0 E color difference from the surface color of the colored coated film layer and the clear layer, are successively formed on the base body. The colored coated film layer is formed by applying a colored paint essentially consisting of a vehicle component and coloring pigments and curing the coating and has about 10 to 50mum film thickness. The fluctuation in the colors as the overall coated film is lessened even if the film thickness of the interference mica-contg. base layer fluctuates if this method is adopted. The management of the painting color in the painting state is thus facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a pearlescent coating film that can reduce hue changes due to changes in film thickness.

[Prior art and its problems] A multi-layer coating film consisting of an interference mica layer and a clear layer coated on top of a colored coating layer has two colors: a reflected color and a transmitted color due to the interference mica pigment.
It has been known for a long time that colors have excellent cosmetic properties. In the interference mica layer, in the direction of specular reflection of light, there is color mixing between the reflected color due to the interference of the interference mica pigment and the color absorbed by the base color layer, and in the direction of retroreflection of light, there is a mixture of the transmitted color as the base color and the colored coating. Mixture of absorbed colors due to the film layer is observed.

Conventionally, interference mica wear paints have been mixed with clear interference mica pigments, and have extremely low interference mica face/hiding power, and variations in the thickness of the interference mica layer have caused the color of the overall paint film to vary greatly. This is a problem in terms of quality control, and a method for forming a multilayer coating film that can produce an interference mica finish with little change in coating color due to variations in film thickness is desired.

[Means for Solving the Problems] As a result of extensive research in order to obtain an interference mica finish with little change in coating color due to variations in film thickness, the present inventors have incorporated a colored pigment into an interference mica shoe paint, It has been discovered that the above object can be achieved by bringing the color closer to the surface color of the base color layer, leading to the present invention.

That is, the present invention is a method for sequentially forming a three-layer coating film, a colored coating layer, an interference mica-containing base layer, and a clear layer, on a substrate, wherein the interference mica-containing base layer contains one colored pigment. 6. The hidden film thickness of the cured paint film obtained from the base layer paint is 1100P or more, and the coating color at the hidden film thickness of the cured paint film has a color difference with respect to the surface color of the colored paint film layer. No. 6 relates to a coating film forming method characterized in that ΔE≦3.0.

The colored coating layer in the method of the present invention is formed on the substrate prior to the interference mica-containing base layer, and is obtained by coating and curing a colored coating whose main components are a vehicle component and a colored pigment. be.

The vehicle component of the above-mentioned colored paint is, for example, acrylic resin,
The main component is a base resin selected from alkyd resins, polyester resins, epoxy resins, and modified resins of these, etc.
Furthermore, curing agents or crosslinking agents such as amine resins, isocyanate compounds, blocked isocyanate compounds, and polyamide resins can be used in combination as necessary. Also, the form of the paint is
Organic ('8 agent soluble if type is common, but non-aqueous multi-liquid type.

It may be of an aqueous solution type, an aqueous dispersion type, a solventless type, or a powder type. Further, as a coloring pigment, it is used in the paint component 'Jf. Either organic colored pigments or inorganic colored pigments can be used.

The coating thickness of the colored paint is approximately 10 to 50 μm based on the cured film thickness, particularly a range of 20 to 35 μm is suitable, and the substrate surface, which is the surface to be coated, may be affected by the color tone of the colored paint. It is preferable that Further, the applied colored paint film is cured at room temperature or by heating.

Next, an interference mica-containing base layer (hereinafter referred to as "base layer") and an interference mica-containing base layer paint (hereinafter referred to as "base layer")
Abbreviated as "base layer paint." ) will be explained.

In the present invention, the base layer coating material is applied to the surface of the colored coating layer, and is mainly composed of an interference mica pigment, a colored pigment, and a vehicle component. Among these components, interference mica pigments are pearlescent flaky pigments based on a thin film coating of titanium dioxide on the surface of flaky mica, and examples include titanium mica and titanium colored mica. . Titanium mica exhibits interference colors such as silver, gold, red, purple, blue, and green depending on the thickness of the titanium dioxide coating. Colored titanium mica is obtained by coating the surface of the titanium mica with colloidal particles of a colored inorganic compound in the form of a thin film to give it a different color than titanium mica.
As.

There are iron oxides, iron hydroxides, chromium oxides, chromium hydroxides, etc., and the coloring with these materials varies depending on the color of the titanium mica itself, but it can be adjusted to various colors. The particle size of interference mica generally ranges from about 5P to about 140-140 mm in longest diameter, with about 5
It is preferably within the range of #1711 to about 60F.

Colored pigments that can be used in the base layer paint include organic color pigments and inorganic color pigments commonly used in the paint field. The paint for the base layer is aluminum powder, MI
It is good if it contains metallic luster +4 such as O.

The vehicle component and the form of the paint used in the base layer paint can be appropriately selected from those exemplified in the explanation regarding the colored paint forming the colored paint layer.

The paint for the base layer must have a hidden film thickness of 100 units or more of a cured coating obtained from this paint, and if the hidden film thickness is less than 100717'1, the cosmetic properties tend to be poor.

In addition, it is necessary that the coating color in the hidden film thickness of this cured coating film has a color difference △E≦3.0 with respect to the surface color of the colored coating layer, and the color of the base layer coating is By bringing the color closer to that of the film layer, changes in hue due to variations in the thickness of the base layer can be reduced. Here △E is JISZ
87306.3, based on Hunter's color difference formula expressed by the a and b systems.

The component ratio in the base layer paint is the solid content weight ratio.

Vehicle component: interference mica color pigment 100%:
0.1-20: preferably 0.01-30.

The paint for the base layer is usually applied to a film thickness of about 5 to about 40 units, often about 10 to about 25 units (cured film thickness), using conventional methods such as electrostatic coating, air spraying, etc. Painting is done by painting, dipping, airless spray painting, etc.

In the present invention, "Full thickness" is 1.0SK54.
00 6.3 means the film thickness (dry) at which the hiding rate is 95%.

Next, the clear layer and the clear and paint forming this layer will be explained.

The clear paint forming the clear layer in the present invention is a paint that forms a transparent coating film applied to the surface of the base layer coating film, and has a vehicle component as its main component. The vehicle component and the form of the paint may be appropriately selected from those exemplified in the explanation regarding the colored paint forming the colored paint layer.

This clear paint can be used with coloring pigments, physical makeup, etc. as needed.
, interference mica pigments, metallic pigments such as aluminum powder, ultraviolet absorbers, etc. may be contained in small amounts.

The thickness of the clear layer is not particularly limited, and is approximately 20 to 70F, particularly 30 to 50F, based on the dry and cured coating.
range of doors is preferred.

Next, a coating film forming method will be explained.

First, the colored paint is applied directly to the object to be coated (four-wheeled vehicles made of metal, plastic, etc. are particularly suitable) (including those whose surfaces have been chemically treated), or by electrocoating paint, etc. Brimer, intermediate coat paint, etc. is applied to the object that has already been coated with top coat paint. Next, a base layer paint is applied to the surface of the colored paint film while it is still uncured or dry, or after it has been cured or dried.

Finally, while the base layer coating film is uncured or undried, or after it is dried as if it were cured, a clear paint is applied and then cured or dried.

Regarding the relationship between the size of the interference mica pigment in the base layer paint and the clear layer, when the interference mica pigment has a relatively small longitudinal dimension of about 30P, the clear paint has a film thickness of about 30 to 50irIR. However, when the longitudinal dimension of the interference mica pigment is relatively large, it is necessary to apply a paint film with excellent sharpness of 40 to 70%.
It is preferable to paint to about F, in this case 40
You may apply more than µ, but you may also apply two coats of clear paint. A method of applying two coats of clear paint is, for example, by applying the metallic paint and the first clear coat wet-on-wet, allowing it to dry until it hardens, then polishing as necessary before applying the second clear coat. Preferably, it is painted, cured, and dried.

In the above coating film forming method, curing is performed at room temperature or at room temperature.

is to crosslink and harden three-dimensionally by heating,
Drying is simply evaporating the solvent to form a coating. The heat curing temperature can be arbitrarily selected depending on the composition of the vehicle used.

(Action/Effect of the Invention) The coating film obtained by the method of the present invention contains colored pigments in the interference mica-containing base layer and has a color close to that of the colored coating film in the lower layer, so the interference mica-containing base layer Even if the film thickness changes, the color variation of the overall coating film can be reduced, making it extremely easy to manage the coating color in the painting process.

(Examples) Examples and comparative examples are given below to further clarify the present invention. In addition, in the following, "department" simply means "department".
Parts by weight.

1. Material to be coated Apply epoxy polyamide cationic N@ paint [trade name "Nileclone N" to a steel plate treated with zinc phosphate.

9000 Black”, manufactured by Kansai Paint Co., Ltd. 1 (cured film thickness 15L
L) and aminoalkyd resin intermediate coating [product name: rES
Brimer TP-16R Gray, manufactured by Kansai Paint Co., Ltd.] (cured film thickness 30u) is used. Both coatings were cured by heating.

2. @Color paint An organic solvent solution type (using a mixed solvent of equal weights of toluene and xylene as the organic solvent) thermosetting paint whose main component is the composition shown in Table 1 below is used.

Table 1 3゜Interference mica-containing base layer paint Organic solvent solution type (using a mixed solvent of equal weights of toluene and xylene as the organic solvent) thermosetting paint whose main component is the composition shown in Table 2 below use.

Table (Note 1) (Note 2): Manufactured by Merck End, mica-based colored pearl pigment, trade name "Iriodin 205 Rutile Bratinum Gold"
.

Manufactured by Merck End, mica-based colored pearl pigment, trade name ``Iriodin l○1 Rutile Silver''.

cormorant? -3 4. Clear paint Thermosetting organic solvent solution type (using a mixed solvent of equal weights of toluene and xylene as the organic solvent) whose main component is a vehicle component consisting of 70 parts of acrylic resin and 30 parts of butylated melamine resin. Use paint.

The above-mentioned colored paint, interference mica-containing base layer paint, and clear paint were applied to the objects to be coated under the conditions shown in Table 3 below.

The tests in Table 3 were conducted according to the following method.

・Changes in the overall appearance of the paint film due to differences in base layer thickness: Regarding three coated plates with base layer thicknesses in three levels: 10P, 15P1n, and 25 units, based on the coated plate with a base layer thickness of 15P, The difference in appearance from the other two coated plates was evaluated visually and by color difference (ΔE) using a 5M-4-CH type tester manufactured by Suga Test Instruments Co., Ltd. The visual evaluation was as follows: 6 0: Good with almost no difference in appearance ×: Difference in appearance clearly recognized

Claims (1)

[Claims] (1) A method of sequentially forming a three-layer coating film, a colored coating layer, an interference mica-containing base layer, and a clear layer, on a substrate, the coating for the interference mica-containing base layer containing a colored pigment, and The hidden film thickness of the cured paint film obtained from the base layer paint is 100 μm or more, and the coating color at the hidden film thickness of the cured film has a color difference ΔE≦3 with respect to the surface color of the colored paint film layer. .0.