JPS63100988A - Coat finishing method - Google Patents

Abstract

PURPOSE:To enhance sheenful properties by using iron oxide pigment covered with titanium dioxide and applying it on a colored coated face regulated to specified lightness and thereafter applying clear paint thereon. CONSTITUTION:Paint which has a vehicle component and colored pigment as an essential component and forms a coat film of 0-6 Munsell value is used and applied so that specified lightness is obtained. Paint contg. pearl pigment (0.1-30pts.wt. pearl pigment having 15-40mu size of lengthwise direction and (1/10-1/20) thickness thereof is contained for 100pts.wt. vehicle component) wherein iron oxide particles having crystalline alpha-iron oxide particles as an essential component are covered with titanium dioxide is applied on this colored coated surface. Furthermore clear paint is applied on this coated surface with 50-100mu film thickness and thereby sheenful properties and design properties are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paint finishing method, and more specifically, its object is to form a paint film with excellent shine by overcoating a colored paint, a pearl pigment-containing paint, and a clear paint.

Conventionally, as a high-quality paint finishing method that gives a shiny appearance to gasoline tanks, frames, cowlings, etc. of two-wheeled vehicles such as scooters and motorcycles, a metallic paint containing flaky metallic pigment such as aluminum powder is applied, and then a clear paint is applied. A two-coat, one-bake method is often used for metallic finishing, in which both coats are coated and then heated to cure both coats at the same time. However, the coating film produced by this method does not provide sufficient sparkle and shine, making it difficult to create a design with depth.Furthermore, the color of the shade surface becomes darker than the front surface, which is undesirable in terms of appearance. Aluminum powder itself is sensitive to acids and alkalis, which can cause stains and blisters. As described above, metallic finishing using aluminum powder or the like is unsuitable for high-quality finishing on motorcycles and the like, and also has problems such as the durability of the coating film.

In order to solve these problems, it has already been proposed to use mica powder coated with a metal oxide such as titanium dioxide in place of the above-mentioned metallic pigment such as aluminum. This pigment is a tabular crystal, and as the incident light repeats incidence and reflection on the surface and internal layers of the pigment, a pearlescent luster is obtained, and compared to aluminum powder, etc., the finished appearance and design are improved. has been improved. However, the refractive index of the mica that makes up the center of this pigment is not much different from that of the paint vehicle component, and most of the incident light is transmitted through it, so the sparkling shine is inferior to that of aluminum powder, and the design is also poor. It cannot be said that it is significantly superior to aluminum powder, etc., and in color coating, mixing different interference colors with different titanium coating film thicknesses is undesirable because it mutually weakens the coloring effect of the interference colors, especially When opposite colors are mixed, the coloring effect of the interference color is completely lost, resulting in a black stain.

For this reason, when painting without using mica powder, there is a serious problem that the color gamut is naturally limited since it is assumed that mica powder is used alone.

Therefore, as a result of extensive research in order to solve these problems, the present inventors used an iron oxide pigment (pearl pigment) coated with titanium dioxide instead of the above-mentioned aluminum powder or mica powder, Then, by applying a paint containing this pigment to a colored coating surface adjusted to a specific lightness, and then applying a clear paint, the object was achieved and the present invention was completed.

That is, the present invention is a method of finishing by overcoating a colored paint, a pearl pigment-containing paint, and a clear paint, wherein the colored paint is a paint that forms a coating film having a Munsell Value (V) of 0 to 6. .

The pearl pigment-containing paint has a pearl pigment and a vehicle component as its main components, and the pearl pigment is a pigment made by coating iron oxide particles, whose main component is α-iron oxide crystal particles, with titanium dioxide. The dimensions are 15 to 40 mm, the thickness is 1/10 to 1/20 of the longitudinal direction, and the vehicle component is 10 mm.
It relates to a painting finishing method characterized by containing 0.1 to 30 parts by weight per 0 parts by weight (solid content).

A feature of the present invention is that a paint containing a pearl pigment made by coating iron liquefied particles containing α-iron oxide crystal particles as a main component with titanium dioxide is applied to a colored coating surface adjusted to a specific brightness. can be given.

In the pearl pigment used in the present invention, the titanium dioxide layer acts as an optical thin film, and incident light is reflected on the surface of the titanium dioxide layer, or is transmitted as is and reflected on the surface of the fermented iron particles. In particular, the iron oxide particles that make up the core of pearl pigments are tabular crystals (hexagonal plates) and have an excellent metallic luster. 〈to reflect. This brightness is significantly superior to that of aluminum powder or the mica powder, and this tendency is even more pronounced under sunlight, and the brightness is almost constant even if the viewing angle is different. In addition, the color of the pearl pigment is determined by the interference effect of light, and the color tone is determined by the product of the optical thickness, geometric thickness, and refractive index of the titanium dioxide layer. Color is generated due to a phase shift due to an optical path difference between the light reflected on the surface and the light that is transmitted through the layer and reflected off the surface of the iron oxide particles. Therefore, this color development may vary depending on the refractive index of the vehicle component of the paint containing the pearl pigment.

When a paint film containing such pearl pigments is exposed to direct sunlight, it takes on a unique sparkling metallic tone no matter what angle it is viewed from, and as the metallic pattern develops due to the interference effect, it appears from deep within the paint film. Gives a three-dimensional color that seems to emit light.

Furthermore, the pearl pigment has good light resistance, weather resistance, chemical resistance, heat resistance, and adhesion.

Moreover, the color appearance due to the pearlescent luster is also three-dimensional. In addition, even in a mixed color system, each color can be fully exhibited and a very unique design can be created.

In addition, in order to sufficiently express the excellent luster of the pearl pigment, the paint containing the pigment is applied to a colored coating surface with a low brightness, the Munsell value (brightness) of which is adjusted to 0 to 6. There is a need to. In other words, when a pearl pigment-containing paint is applied to the surface of a colored paint film whose brightness has been adjusted to a low brightness, the unique luster of the pearl pigment can be fully exhibited. It looks sparkling and shining. Such finish quality cannot be expected with aluminum powder, mica powder, etc.

Color adjustment in the brushing method of the present invention can be carried out arbitrarily and easily by combining the color tone of the colored coating film and various interference colors of the pearl pigment. If the color gamuts of the two are approximated, a coating film with no color bleeds or unevenness will be produced due to the additive effect, but the brightness may decrease slightly.On the other hand, if the color tones of the two are made to be different, the pearl pigment The design is excellent because it can fully exhibit glitter, and the color tone, especially on the shade surface, can be freely controlled.

The painting finishing method of the present invention will be explained in more detail.

Colored paint: The main components are vehicle components and color pigments,
Moreover, the Munsell value (V) is 0 to 6, preferably 0
．． This is a paint that forms 3 to 3 coats and is applied prior to applying the pearl pigment-containing paint. If the Munsell value is greater than 6, it is undesirable because it is too bright and the glittering properties of the pearl pigment are significantly reduced. The Munsell value (V) is the lightness of the three color elements (lightness, hue, and saturation).

The brightness of the colored coating layer can be easily adjusted by adjusting the type, composition ratio, and amount of the colored pigment added to the colored paint.

The colored paint used in the present invention may be any paint that forms a coating film with a luminosity similar to that described above.Specifically, it may be used as an undercoat paint (electrodeposition paint is also used), which is already used in many fields. (including), intermediate coating paints, and top coating paints that can form a coating film of the above hue, such as organic solvent solution type, non-aqueous dispersion type, aqueous dispersion type, aqueous solution type,
Solvent-free and powder paints can be used. this house,
In order to maintain a high level of finished appearance and durability, it is preferable to use an organic solvent solution type top coat.

The vehicle component of the colored paint is 1.The main component is a base resin selected from acrylic resins, fluorocarbon resins, polyester resins, epoxy resins, and modified resins of these resins, as well as amino resins and isocyanate compounds (including blocked products). ), a curing agent (or crosslinking agent) such as polyamide resin, etc. can be used in combination as necessary.

The colored paint film is cured by crosslinking (crosslinking) at room temperature or by heating.
Curing) or non-crosslinking (drying).

The coating film thickness of the colored paint is suitably in the range of 10 to 50 JL, especially 20 to 35 JL, based on the cured or dried film, and the surface to be coated is completely hidden by the color tone of the colored paint. Preferably I/~.

Pearl pigment-containing paint: A paint that is applied to the surface of the colored paint layer, which is made by coating iron oxide particles whose main component is α-iron oxide crystal particles with titanium dioxide, and whose longitudinal dimension is 15
Larger than μ up to 4oJL, thickness is l/1 in the longitudinal direction
0 to 1/20 of the pearl pigment per 100 parts by weight of the vehicle component.

The paint contains 0.1 to 30 parts by weight.

The pearl pigment used in the present invention is α-iron oxide (FezOx
) It is a pigment whose core is flat (hexagonal plate-shaped) iron oxide whose main component is crystal grains, and whose surface is coated with titanium dioxide. The tabular iron oxide forming this core is α-Fe2
03 at least 80% by weight, preferably 90% or more, more preferably 98! I! Contains i% or more, S+
02, FeO, etc., have little or no content (both 0.5
mm%], and it itself has a sparkling luster.

The pearl pigment coated with titanium dioxide has a flat plate shape (hexagonal plate shape), and its longitudinal dimension is larger than 15 tiles and 40 microns or less, preferably 25 to 35 microns, and the thickness is 1 inch in the long horizontal direction. /10 to l/20, preferably 1/10 to 1
/15. If the longitudinal direction is less than 15 g, the brightness will not be sufficient when applied to objects with small coating areas such as motorcycles, while if it is larger than 40 g, painting workability will decrease and the top coat will need to be thicker. It is uneconomical.

Moreover, if the thickness becomes thicker than 1/10 in the longitudinal direction, the pearl pigment tends to protrude from the coated surface and the finishing quality deteriorates, while if it becomes smaller than 1/20, the glitter property deteriorates. The dimension of the pearl pigment in the longitudinal direction was measured using a laser particle size distribution measuring device PARTICLE 5IZER22.
00 [manufactured by MALVERN (UK)].

Regarding the longitudinal dimension of the pearl pigment used in the present invention, most of it (for example, about 90% by weight or more, preferably 9% by weight or more)
5% by weight or more) is distributed in 40p or less, and in the present invention, the above-mentioned "bigger than 15L and 40g or less" means that the pigment within this range is 70% by weight or more, preferably 80% by weight or less of the total Burr pigment. - Contains hydrogen, and
"Preferably 25 to 35p" means that the total pearl pigment content in this range is 25% by weight or more, particularly 35% by weight. 1 In the present invention, the content of pearl pigments with 5 to 15 ends is less than 40% by weight in the total pearl pigments,
In particular, it needs to be less than 50% by weight. The titanium dioxide that coats the surface of the iron oxide particles is generally anatase type, but the use of rutile type improves the weatherability.

Regarding the pearl pigment used in the present invention, the proportion of the coated titanium dioxide layer is 0.1 based on the total weight of the pearl pigment.
~30% by weight, especially 0.3-30% by weight is preferred.

Such pearl pigments combine the iron oxide particles with titanyl oxide (
TiOSO, 5.2H20), sulfuric acid
OsOa e5.2H20), titanium tetrachloride (TiC
14) and zirconium sulfate (Z r C3Oa )2
- Obtained by heat treatment in a solution of a metal resistant material (hydroxide is also possible) such as 4H20), washing with water, and drying. Furthermore, when this dried product is roasted at about 600°C and crystallized, weather resistance and gloss are improved. The color tone can be changed by heat-treating these with aluminum sulfate (A-X2 (S04)3, 18H20) or the like.

The color tone of the pearl pigment thus obtained can be arbitrarily adjusted by using the above-mentioned processing agent and processing method, such as blue, greenish blue, yellow, purple, reddish-purple,
It can be toned to reddish brown, light blue, gold, etc., and has an excellent shine.

The vehicle component is used to disperse the pearl pigment and form a coating film, and resins for coatings that are known per se and have excellent weather resistance, physical and chemical properties can be used. Specifically, thermosetting resins made by mixing base resins such as acrylic resins, polyester resins, or alkyd resins with crosslinking agents such as 7mino resins and incyanate compounds (including blocked compounds) are most preferred, but other than these Additionally, paint resins that dry or harden at room temperature can also be used. These paints are generally in the form of organic solutions, but may also be in the form of non-aqueous dispersions, aqueous solutions, aqueous dispersions, solvent-free or powder forms.

The blending amount of pearl pigment is vehicle component (solid content) 100
Per part by weight, 0.1 to 30 parts by weight, particularly 5 to 20 parts by weight are preferred.

The method of blending (dispersing) the pearl pigment into the vehicle component is not particularly limited, but it is preferable to avoid strong dispersion in order not to destroy the coated titanium dioxide layer, and the pearl pigment can be easily dispersed using an ordinary dispersion stirrer. be able to.

In addition to these two components, the pearl pigment-containing paint, which has a pearl pigment and a vehicle component as its main components, may contain ordinary metallic pigments, coloring pigments, extender pigments, various paint additives, etc. according to the present invention. It can be blended to the extent that it does not impair the desired design quality.

The coating material is applied to the surface of the colored coating IIg layer by a conventional method such as electrostatic coating, spray coating, dip coating, or airless coating. The thickness of the coating film is preferably 10 to 30 g, particularly 15 to 25 g, depending on the detonation or cured coating.

Clear coating;): A coating that forms a transparent coating on the coating surface of a pearl pigment-containing coating, and has a vehicle component as its main component.

As for the vehicle components, the form of the paint, the coating method, etc., those selected from those exemplified for the pearl pigment paint can be used. The paint may also contain a certain amount of a colored pigment, an extender pigment, a metallic pigment, the above-mentioned mica pigment, a pearl pigment, an ultraviolet absorber, etc., if necessary.

The thickness of the clear coating layer is not particularly limited, but it is 50 to 1OOμ, especially 60 to 80μ for dry cured coatings.
A range of μ is preferred.

Paint finishing method: First, the colored paint is applied directly to the object to be painted (particularly suitable are gasoline wheels, frames, cowlings, etc. of motorcycles made of plastic, etc.) (the surface of which has been chemically treated). ), or apply a primer (electrodeposition paint, etc.), intermediate coat paint, or one-coat paint to an object that has already been coated.

Next, after the colored paint film is unhardened or undried (wet), or after it has been cured or dried, a pearl pigment-containing paint is applied to the surface of the paint film.

After hk, the pearl pigment-containing paint film is uncured or undried (wet), or after it has been hardened or dried, a clear paint is applied.

Among these finishing methods, if a pearl pigment-containing paint is applied to an uncured or undried colored paint surface, a portion of the pearl pigment will sink into the colored paint surface, so the thickness of the clear paint film must be adjusted. Can be made thinner.

In addition, looking at the relationship between the size of the pearl pigment in the pearl pigment-containing paint and the film thickness of the clear paint, it is found that if the longitudinal direction of the pearl pigment is 20 yL or less, the clear paint
A coating film with excellent image clarity can be achieved by coating to a film thickness of 0 to 50 colors, but if the pearl pigment is larger than 20μ, a coating film of 60 to 80 IL is required to achieve excellent image clarity. It is preferable to paint thickly, and in this case, if it is difficult to paint more than 40 mm in one go, clear paint may be applied twice. As a method of applying two coats of clear paint, for example, the pearl pigment-containing paint and the first clear coat are coated wet-on-wet, and then the first coat is cured or dried, and then polished if necessary. It is preferable to apply a second clear paint, harden and dry.

In these coating processes, curing is three-dimensional crosslinking and curing at room temperature or heating, and drying is simply evaporating the solvent to form a coating film. The heat curing temperature can be arbitrarily selected depending on the Nl composition of the vehicle used.

In the method of the present invention, it is possible to freely control the color gamut mainly by combining the color tone of the colored coating film and various interference colors of the pearl pigment, but if the pearl pigment has a low brightness, the colored coating It is preferable to set the hue of the film to a low brightness range.

The pearl pigment used in the present invention has the following design effects when compared with a coating color that does not use mica powder.

(1) It has both sides of metallic style fist and solid style. In other words, when exposed to direct sunlight, it exhibits a unique brilliance that far exceeds that of aluminum or mica powder, and when exposed to sunlight, it becomes completely solid.

(2) Regarding the shine under direct sunlight, the same shine is produced not only in the highlights but also at all angles.
It gives off a brilliance that looks like it is studded with diamonds, giving it a three-dimensional color feel.

(3) When coloring using mica powder, mixing of different interference colors must be avoided as it weakens the coloring effect.
The pearl pigment used in the present invention further improves its design by mixing different interference colors.

That is, since each interference color emits its own interference color even when mixed, it is possible to obtain a very specific design effect in which various pearlescent colors appear to shine in the coating film.

(4) Further, by combining the present pearl pigment with other coloring materials, directionality in glitter can be obtained. That is, by combining it with an appropriate amount of aluminum/mica powder, it is possible to achieve the brilliance of the combined color material in highlights and the brilliance of the present pearl pigment in shade areas. The reason why such a design effect can be obtained is that this pearl pigment has a sense of brilliance in all aspects.

(5) By varying the hue of the colored coating film used in combination with this pearl pigment in a low lightness range that does not impair the design effect, it is possible to freely control the hue of the shade and obtain new design properties. Can be done.

Examples, comparative examples 1. Object to be coated Steel plate treated with phosphorous zinc.

2. Colored paint This is an organic solution-type thermosetting paint whose main components are the compositions shown in Table 1 below.

Table 1, Pearl Pigment-Containing Paint This is an organic solution-type thermosetting paint whose main component is the composition shown in Table 2 below.

Table 2, 8] Part 4 Clear Paint An organic solution-type thermosetting paint whose main component is a vehicle component consisting of 70 parts of an acrylic resin and 30 parts of a butylated melamine resin.

5. Examples and Comparative Examples Using the various paints obtained as described above, objects to be coated were coated according to the steps in Table 3 below. In Table 3.

("1): 0 in the baking column indicates that the coating was baked at 140°C for 30 minutes, and X indicates that the coating was set at room temperature for 5 to 10 minutes without baking before moving on to the next step.

(''2) (''3): Pearl pigment in pearl pigment-containing paint, aluminum powder in ($2), ('3
), each was applied to mica powder coated with titanium dioxide.

All of the paint films finished in Examples 1 to 8 glow uniformly when exposed to sunlight, and the way they shine looks like diamonds have been encrusted from within the paint film, giving it an excellent three-dimensional color feel. was.

However, in Examples 1 to 3, the hue of the colored paint was slightly brighter, so the design was slightly inferior.

On the other hand, Comparative Example 1 used aluminum powder,
There is almost no glittering brilliance, and the design quality is poor. Comparative Example 2 also had insufficient glitter and color.

Claims (1)

[Claims] A method of finishing by overcoating a colored paint, a pearl pigment-containing paint, and a clear paint, wherein the colored paint is a paint that forms a coating film having a Munsell Value (V) of 0 to 6. The pearl pigment-containing paint has a pearl pigment and a vehicle component as its main components, and the pearl pigment is a pigment made by coating iron oxide particles, whose main component is α-iron oxide crystal particles, with titanium dioxide. Directional dimension is 15μ or more to 40
A coating finishing method characterized by having a thickness of 1/10 to 1/20 of the longitudinal direction and containing 0.1 to 30 parts by weight per 100 parts by weight (solid content) of a vehicle component.