JPH03124780A - Coating composition and formation of coating film - Google Patents

Abstract

PURPOSE:To make it possible to form a coating film which is dense and has a glittering surface by compounding a specified biotite and a coloring pigment in a resin component. CONSTITUTION:A coating compsn. is obtd. by compounding 100 pts.wt. (solid content) resin component, if necessary, dissolved or dispersed in an org. solvent and/or water, 5.0-50 pts.wt. biotite with a length in the longitudinal direction of 5-50mu, pref. 10-30mu and a length in the lateral direction of 0.1-5mu, pref. 0.3-1.0mu, 0.1-50 pts.wt. inorg. or org. coloring pigment with a particle diameter of pref. 1mu or smaller and, if necessary, a metallic pigment, a pigment dispersing agent, an org. modified silicone, an anti-forming agent, a curing catalyst, etc. A base material is coated with this coating compsn. to form a coating film, which is coated with a clear coating material to give a transparent coating film.

Description

[Detailed Description of the Invention] Go! Top Ω plate and ball! The present invention relates to a novel coating composition that forms a coating film with excellent cosmetic properties, and a coating film forming method using the same.

Ma no 1 bisono. Top coatings for the exterior panels of automobiles, motorcycles, etc. can be roughly divided into solid color finishing methods using colored pigments and metallic finishing methods that exhibit a glittering effect. The latter metallic color usually contains a metallic pigment such as aluminum or pearl mica to give a sense of brilliance.

However, the solid color finish has a flat color tone and no glitter, and is therefore inferior in cosmetic properties.On the other hand, the coating film with a metallic finish has a sparkling shine and is excellent in cosmetic properties. However, when looking at its glitter properties, the shine from the individual particles of metallic pigments is too strong, and the dense and continuous surface that metals inherently have is difficult to finish (it is impossible to finish a painted surface with a glittering feeling). It was impossible.

In order to improve fortune-telling, the inventors of the present invention have developed a coating composition capable of forming a coating film that is dense and has a glittering appearance that shines on the surface (as a result of extensive research, the following It has been found that a coating composition containing a specific mica powder and a colored pigment meets the intended purpose of the present invention.

The present invention was completed based on this knowledge.

That is, the present invention has the following features: (1) The longitudinal dimension is 5 to 50 μm, and the transverse dimension is 0.5 μm.
Coating a coating composition containing biotite and a colored pigment having a particle size of 1 to 5μ, and (2) coating the coating composition of (1) above, and then coating the coated surface with a clear coating that forms a transparent coating. This invention relates to a coating film forming method characterized by:

First, the coating composition of the present invention will be explained.

The coating composition contains biotite having a longitudinal dimension of 5 to 50 microns and a transversal dimension of 0.1 to 5 microns, and a colored pigment.

The biotite used in the present invention is biotite (biotite).
Also called title, it is composed of elements such as K, Mg, Fe, Si, and AI2, as well as O and (OH), and is contained in acid rocks such as cakkoite and dacite, and alkaline igneous rocks, and has a layered structure. have. Optically, the color may vary depending on the composition, but the color in thin sections is brown, reddish brown, yellowish brown, and green, and the color is strongly pleochroic, and the shape is often scale-like. , the longitudinal dimension is 5 to 50μ, particularly preferably 10 to 3
0 μ, width direction dimension is 0.1 to 5 μ, particularly preferably 0
．． A material having a shape within the range of 3 to 1.0 μm is used. If the longitudinal dimension is smaller than 5μ, the brightness will decrease and it will be difficult to achieve the objective, while if it is larger than 50μ, the biotite will protrude from the painted surface, reducing the smoothness, and If the size is smaller than 0.1 μm, it will be difficult to obtain a coating film with the desired glitter, while if it is larger than 5 μm, the glitter will decrease, so both are not preferred.

A commercially available product of such biotite includes, for example, "Metal Light" (trade name, manufactured by Yamaro Mica Kogyo Co., Ltd.).

Furthermore, as the coloring pigment used together with biotite, inorganic or organic coloring pigments that are blended as colorants in ordinary paints can be used. As a preferred colored pigment, particle size (diameter)
Examples include achromatic pigments and chromatic pigments with a diameter of 1μ or less.

Specific examples of achromatic pigments include titanium white and carbon black. In addition, chromatic pigments include titanium white and 1
The color obtained by mixing =1 is Munsell hue, which is Y, YG,
A wide variety of pigments such as G, BG, B, PB, P, or RP can be used, and among these, pigments that are as transparent as possible are preferred.

Among these, in order to fully exhibit the cosmetic properties based on biotite, the lightness (Lo) of the coating film containing biotite is 55.
Below, preferably 53 or less, particularly preferably 53 to 20
It is made by mixing and dispersing colored pigments in a resin component so that the coloring pigments are mixed and dispersed in a resin component.

The resin components blended into the coating composition of the present invention include:
There are no particular limitations, such as thermosetting acrylic resin/melamine resin, thermosetting acrylic resin/CAB/
Melamine resin, thermosetting polyester (alkyd) resin/melamine resin, thermosetting polyester (alkyd) resin/CAB/melamine resin, isocyanate curing urethane resin, room temperature drying acrylic resin, emulsion type water dilutable/melamine resin etc. can be mentioned.

These resin components are pre-treated with organic solvents and/or
It is preferably dissolved or dispersed in water, and its forms include solution type, dispersion type, high solid type, and non-aqueous dispersion type.

In the coating composition of the present invention, the blending amount of biotite is preferably 5.0 to 50 parts by weight per 100 parts by weight (solid content) of the resin component. There is a tendency for the brilliance and shine to be lost. On the other hand, if the amount exceeds 50 parts by weight, smoothness may be impaired and sufficient gloss and sharpness may not be ensured.

The amount of the coloring pigment varies depending on the type of coloring pigment used, etc., and cannot be generalized, but it is usually 0.1 to 100 parts by weight (solid content) of the resin component blended into the composition of the present invention. It is better to use 50 parts by weight or more, more specifically, for example, when using titanium white, the resin component should be 100 parts by weight or more.
0.1 to 10 parts by weight per part by weight, preferably 0.1
~5 parts by weight is particularly preferred, and when carbon black is used, it is preferably from 0.1 to 100 parts by weight of the resin component.
5 parts by weight is preferable, and 0.1 to 2 parts by weight is particularly preferable. Furthermore, when a chromatic pigment is used, it is preferably about 20 parts by weight or less per 100 parts by weight of the resin component.1.
Preferably 0 to 10 parts by weight.

In the coating composition of the present invention, in addition to biotite and colored pigments, metallic pigments can be blended as necessary. Examples of such metallic pigments include aluminum powder, bronze powder, stainless steel powder, titanium powder, chromium powder, pearl mica, colored pearl mica, interference pearl mica, mica-like iron oxide, titanium-coated mica-like iron oxide, and phthalocyanine plate crystals. etc. can be given. The blending amount of these metallic pigments is 30 parts by weight or less, preferably 0 parts by weight, per 100 parts by weight of the solid content of the resin component.
．． It is desirable that the amount is 5 to 5 parts by weight.

In producing the coating composition of the present invention, the method for blending the biotite is not particularly limited, but
Typical methods are shown in (1) to (3) below.

(1) Biotite is added to a resin varnish that does not contain a colored pigment or a resin varnish in which a colored pigment or the like is dispersed, and is dispersed in the resin by stirring.

(2) After mixing the resin varnish and biotite, they are stirred using a dispersing machine such as a ball mill or a sand mill in the same manner as colored pigments.

(3) Mix biotite and a solvent, stir, and then add to the resin.

The coating composition of the present invention may further contain additives such as a pigment dispersant, an organically modified silicone, and an antifoaming agent, a curing catalyst, and the like, if necessary.

Next, the coating film forming method of the present invention will be explained.

The method of the present invention is characterized in that the coating composition of the present invention described above is coated, and the coated surface is coated with a clear paint.

Examples of the base material (object to be coated) used in the present invention include metals such as steel and aluminum, and plastic base materials represented by polyurethane, polypropylene, and the like. The base material has been previously coated with an electrodeposition coating and/or an undercoat or intermediate coat, if necessary. The 1F coating method and the undercoating and intermediate coating methods are not particularly limited, and conventionally known methods may be used.

In the present invention, a colored base coat layer is formed on such a substrate using the coating composition of the present invention, and a clear paint is further applied on the colored base coat layer to form a clear coat layer. The formation of the clear coat layer can be carried out, for example, by appropriately diluting the coating composition of the present invention with a thinner to a viscosity suitable for coating, spraying it on the substrate, and then baking or not baking it. (A clear paint for forming a clear coat layer may be spray-painted and then baked. Among this method, the coating composition of the present invention is spray-painted onto a substrate and a clear coat layer is formed without baking. It is preferable to use the so-called 2-coat, 1-bake method, in which a clear paint is spray-painted for the purpose and then baked.The spray-painting method may be either electrostatic or non-electrostatic; The machine may be either a spray gun or a mini-bell type rotary atomizer, but it is preferable to use a non-electrostatic air atomizing spray gun.The baking conditions are not different from conventional ones, for example,
The coating film is preferably cured and dried by baking at a temperature of 140°C for 20 to 40 minutes.

The amount of the coating composition and clear coating of the present invention to be used is as follows:
Although not particularly limited, the cured dry film thickness of the colored base coat layer is usually about 10 to 30μ, preferably about 15μ.
It is preferable to use each of the above compositions so that the cured dry film thickness of the clear coat layer is usually about 20 to 60 microns, preferably about 30 to 50 microns. If the hiding power of the colored base coat layer is low, the thickness of the colored base coat layer may be made thicker, but if the substrate is previously coated with a low lightness intermediate coating with a Munsell lightness of about 0.5 to 2, the colored base coat layer may be thicker. Even if the base coat layer is thin, the appearance can be hidden.

Further, the clear coat layer may be formed on the colored base coat layer in two steps by the method shown below. That is, after coating and baking the clear paint on the colored base coat layer, the clear coat layer is further coated. It is also possible to perform baking, and in this way, a coating film with excellent image clarity, durability, etc. can be formed on the substrate.

Since the coating composition of the present invention contains a specific biotite powder, the coating film formed thereby has a three-dimensional and deep feeling compared to conventional solid color coatings. It also has a dense, continuous surface with a metallic luster that shines with less sparkle than metallic coatings.

Such metallic luster could not be obtained even with conventional metallic pigments such as aluminum and burr mica.

Furthermore, when a clear paint is applied to the painted surface, image clarity, smoothness, weather resistance, etc. are improved.

1 barrel Examples are given below to further clarify the present invention.

In the following, "parts" simply means "parts by weight."

A cationic electrodeposition paint (Nileclone 9400, manufactured by Kansai Paint Co., Ltd.) is electrodeposited on a steel plate, and then a polyester/melamine resin intermediate coating resin (ES Brimer T) is applied on top of this.
P-37, manufactured by Kansai Paint Co., Ltd.) 100 copies, titanium white (R
-650, manufactured by Sakai Chemical Industries, Ltd.), 40 parts of barium sulfate (Baryta #100, manufactured by Sakai Chemical Industries, Ltd.), and 4 parts of carbon black (Carbon MA-100, Mitsubishi Carbon). An intermediate coat was applied using the paint.

The coating composition of the present invention and the clear paint having the compositions shown below were applied to the steel plate which had been subjected to the electrodeposition coating and the intermediate coating, using the 2-coat, 1-bake method (after coating the coating of the present invention, the clear coating was subsequently applied). and baking at 140° C. for 30 minutes) to form a colored base coat layer with a dry thickness of 15 to 20 μm and a clear coat layer with a dry thickness of 45 μm.

The composition of the colored base coat used in this painting process is shown in Table 1.

In Table 1, (1) Carbon black = “Black Pearls 130
0A-73J Manufactured by CABOT, product name (2) Titanium white: "Titanium dioxide JR-7
014 Manufactured by Teikoku Kako, trade name (3) Cyanine Blue G-314: Manufactured by Sanyo Shiki Co., Ltd., trade name (4) Monolight Blue 3R: Manufactured by ICI, trade name (5) Chromofine Red R-6820: Dainichiseika Manufactured by Merck Japan, product name (6) Pearl mica: “Iriodin 219 Rutile Lilac Pearl” Manufactured by Merck Japan, product name (7) Aluminum powder: “Aluminum Paste 1980
0J, manufactured by Asahi Kasei Metals Co., Ltd., trade name clear paint, is a butyl etherified melamine resin/hydroxyl group-containing acrylic resin thermosetting paint.

Performance test results A coating film (3
Coat 2 bake) was evaluated.

The coating films obtained by using the coating compositions of the present invention (Examples 1 to 5) as colored pace coats were very dense, and a deep three-dimensional coating film with glittering luster on a continuous surface was obtained. , which fully achieves the purpose of the present invention. On the other hand, the product using Comparative Example 1 had a rough shine and a sense of depth (three-dimensional effect).
In addition, Comparative Example 2 had a strong shine and became rough, making it difficult to finish a coating film that shined on a continuous surface.

Claims (2)

[Claims] (1) The longitudinal dimension is 5 to 50μ, the transversal dimension is 0.
A coating composition containing biotite having a particle size of 1 to 5μ and a colored pigment. (2) A method for forming a coating film, which comprises applying the coating composition of (1) above, and then coating the coated surface with a clear coating material that forms a transparent coating film.