JPH04268383A - Metallic coating material - Google Patents

Abstract

PURPOSE:To develop the interference color and metallic brightness with sufficient intensities and increase the hiding power of a metallic coating material contg. a mica pigment such as a pearl mica pigment. CONSTITUTION:A metallic coating material which contains a pigment comprising a transparent or translucent flake 100, a TiO2 layer 101 formed to cover the whole surface of the flake 100, light-absorbing parts 102 comprising a lower oxide of titanium and formed in the form of scattered dots on the surface of the TiO2 layer 101, and brightening parts 103 having a metallic luster and formed in the form of scattered dots on the surface of the TiO2 layer 102. The light-absorbing parts 102 serve to increase (hiding power, and the light which weakens interference color by recompositing with interference light can be decreased.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallic paint used as a top coat for automobiles, etc.

0002

2. Description of the Related Art Metallic paints containing foil-like aluminum powder have been widely used for top coating of automobiles. Although this metallic paint has a high hiding power and is preferable, it has been difficult to form a pale metallic paint color because the brightness of aluminum is not so high.

[0003] Therefore, in recent years, metallic paints containing pearl mica pigments with a TiO2 layer formed on the mica surface have been developed and put into practical use. This metallic paint develops an interference color due to the high refractive index of TiO2 as well as the pearly luster of mica, and gives a sparkling metallic appearance even when painted in a monochromatic color. However, metallic paints containing pearl mica pigments have poor hiding power, and are often difficult to apply using the current two-coat, one-bake system for car painting. Furthermore, the resulting coating film had a problem of lacking metallic luster when viewed from an oblique direction (shade).

[0004] Furthermore, JP-A-1-104673 discloses a metallic paint containing a pigment in which a glittering metal is deposited on a part of the surface of mica by sputtering. However, with this paint, only a metallic luster effect can be obtained and the design is poor.

[0005]

[Problems to be Solved by the Invention] In order to improve these problems, Japanese Patent Laid-Open No. 1-1-1 filed by the applicant of the present application
No. 08267 discloses a pigment having metallic glitter parts formed in the form of islands on the surface of pearl mica. A metallic paint using this pigment has improved metallic luster when viewed from an oblique direction (shade) and has improved hiding power. However, even in this metallic paint, the hiding power and strength of interference color are not sufficient, and further improvements are desired.

The present invention has been made in view of the above circumstances, and aims to develop interference colors and metallic glitter with sufficient intensity and to increase hiding power.

[0007]

[Means for Solving the Problems] The present inventors have conducted extensive research to improve the intensity of interference color and hiding power of the pigment disclosed in JP-A-1-108267, and as a result, they have completed the present invention. I came to the conclusion. That is, the metallic paint of the present invention consists of a translucent scale-like base material, a TiO2 layer coated on the entire surface of the base material, and a lower titanium oxide formed dotted on the surface of the TiO2 layer. A light absorbing part,
It is characterized by containing a pigment consisting of glittering parts having metallic luster formed in scattered dots on the surface of the TiO2 layer.

A feature of the present invention is that it contains a novel pigment. This pigment will be explained. The base material forms the base of the pigment, and transparent or translucent scale-like materials such as mica, glass foil, molybdenum disulfide, and Fe2 O3 are used. Mica naturally occurring as a scale-like crystal is particularly preferred, and natural mica and synthetic mica such as muscovite, biotite, and phlogopite can be used.

[0009] Normally, this base material is scale-like with a (thickness/length) ratio of approximately (1 to 5)/100, the average thickness is approximately 500 to 1000 Å, and the length of one piece is approximately 500 to 1000 Å. 3-50
It is about μm. The TiO2 layer is similar to the TiO2 layer of conventional pearl mica and is coated on the entire surface of the substrate. Depending on the thickness of this TiO2 layer, interference colors of various tones can be produced.

The most distinctive feature of this pigment is that it has light-absorbing parts and bright parts formed in scattered dots on the surface of the TiO2 layer. Here, the light absorbing portion is composed of a low-order oxide of titanium. Unlike TiO2, which is colorless and transparent, lower-order oxides of titanium have reflective and absorbing properties. Therefore, it has object colors ranging from blue to brown to black, and various colors can be obtained in combination with interference colors from the TiO2 layer. This light absorbing portion can be formed by locally reducing the TiO2 layer. In addition, the lower oxide of titanium is TiO2
It may also be deposited in scattered spots on the surface of the layer. It is particularly convenient to form it simultaneously with the formation of the bright portion, as will be described later.

[0011] The bright part has a metallic luster and can be processed by chemical methods such as electroplating or electroless plating, sputtering, vapor deposition,
By a physical method such as ion plating, titanium, zirconium, tungsten, nickel, aluminum, silver, platinum, gold, etc. can be formed in a dotted manner. For example, sputtering titanium to TiO2
When deposited on the TiO layer, the TiO
A portion of the two layers is reduced to form a light absorbing portion made of a lower titanium oxide at the same time.

[0012] The total projected area of the light absorbing part and the bright part on the TiO2 layer is 0.00% relative to the total surface area of the TiO2 layer.
It is desirable to form it so that it may be in the range of 0.03 to 98%. When it is less than 0.03%, the hiding power decreases, and when it is more than 98%, the interference color development becomes weak. Further, the light absorbing part and the bright part may be formed separately on the TiO2 layer, or the bright part can be formed by overlapping the light absorbing part. Further, in order to impart weather resistance to the pigment, surface treatment may be performed. As the surface treatment, chromium-based, alumina-based, zirconia-based treatments, etc. can be applied.

The metallic paint of the present invention contains a resin constituting the matrix, other pigments, additives, etc. as other components. As the resin, various resins used in conventional metallic paints such as acrylic resin, melamine resin, and polyester resin can be used. In addition, the pigment may be composed only of the above-mentioned new pigment,
It can also be used in combination with conventional pearl mica pigments, various organic pigments, and inorganic pigments. Furthermore, various conventionally used additives such as dispersants, plasticizers, and surface conditioners can also be used.

The above novel pigment is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the solid content of the metallic paint of the present invention. If the content is less than 1 part by weight, the effect of the content will be insufficient, and if it is more than 20 parts by weight, the dispersion stability will decrease and the clarity of the coating film and the workability of painting will decrease.

[0015]

Effects and Effects of the Invention As shown in FIG. 2, the pigment contained in the metallic paint of the present invention includes, for example, TiO2
Reflected light A reflected on the surface of layer 101 and TiO2 layer 101
and the reflected light B reflected at the interface with the base material 100 interfere,
It develops an interference color determined by (thickness of TiO2 layer x refractive index of TiO2 layer). Further, a part of the incident light is absorbed in the light absorption section 102, and the reflected light C produces the object color of the light absorption section 102. Furthermore, the reflected light D reflected by the bright part 103
This gives a metallic shine. Therefore, it is possible to obtain a deep and unique colored metallic color tone that is a combination of these reflected lights, interference lights, absorbed lights, metallic luster, and the like.

[0016] In general, the hiding power of a pigment decreases as more light passes through the pigment. With the new pigment contained in the metallic paint of the present invention, a portion of the light F that has passed through the base material is absorbed by the light absorption part 102 on the opposite side, so the amount of light transmitted is smaller than that of conventional mica pigments and is concealed. Strength improves. Furthermore, when viewed with a shade, the light absorption effect of the light absorbing portion 102 reduces diffused reflection and produces bright colors, so that the contrast with the front view is large and good flip-flop properties are exhibited.

Further, the reflected light E that passes through the pigment, is reflected on the surface of the base or other pigments, enters the pigment again, and is transmitted through the pigment is recombined with the reflected light A and the reflected light B, thereby weakening the interference light. However, in the pigment of the present invention, part of the light that has passed through the base material is absorbed by the light absorption section 102 on the opposite side, and some of the light that has passed through the pigment is reflected by the base or other pigment surfaces and re-entered the pigment. Since a portion of the reflected light E is also absorbed by the light absorbing portion 102, the amount of reflected light E is reduced compared to conventional mica pigments. This prevents the interference light from being weakened and produces a strong interference color.

Therefore, according to the metallic paint of the present invention, it is possible to obtain a metallic luster, a strong interference color, and color development based on the object color of the light-absorbing portion, and furthermore, it has a large hiding power, so it is extremely useful as a top coating for automobiles.

[0019]

[Examples] The present invention will be specifically explained below with reference to Examples. [Example 1] FIGS. 1 and 2 are schematic cross-sectional views of a pigment used in a metallic paint according to an example of the present invention. This pigment consists of mica 100 as a scaly base material and mica 100 as a scaly base material.
A TiO2 layer 101 is formed on the entire surface of the TiO2 layer 101.
A light absorbing portion 102 made of a low-order oxide of titanium is formed in a dotted manner on the surface of the O2 layer 101, and a bright portion 1 made of titanium is formed on the surface of the light absorbing portion 102, respectively.
03. The method for producing this pigment will be explained below. (Manufacture of pearl mica pigment) Mica flakes (diameter 10~
20 μm, thickness approximately 0.5 μm) was added to 500 ml of ion-exchanged water, and thoroughly stirred to uniformly disperse it. 158.2 ml of an aqueous titanyl sulfate solution having a concentration of 40% by weight was added to the obtained dispersion, and the mixture was heated with stirring and boiled for 6 hours. After cooling, it is filtered, washed with water, and baked at 900℃.
90 g of red pearl mica pigment whose surface was coated with TiO2 was obtained. (Description of powder sputtering equipment) Next, FIGS. 3 and 4
Titanium was sputtered onto the pearl mica pigment using the powder sputtering apparatus shown in FIG. This powder sputtering apparatus is comprised of a reduced pressure heat treatment chamber 1, a rotating barrel type sputtering chamber 2, a fluid jet mill 3, and a powder filter 4.

The reduced pressure heat treatment chamber 1 is a container heated by electrical resistance, and communicates with a main exhaust system 6 and an advanced exhaust system 7 via a filter 5. The main exhaust system 6 is a mechanical vacuum pump, and the advanced exhaust system 7 is a combination of a cryosorption pump, a turbomolecular pump, a mechanical booster pump, etc., and a cooling trap. This vacuum heat treatment chamber 1 is equipped with a screw feeder 9 and a motor 40 that rotates the screw feeder 9, and is configured to drop the fine powder 8 subjected to the vacuum heat treatment into a conduit 10 that feeds it into the rotating barrel type sputtering chamber 2. There is.

The rotating barrel type sputtering chamber 2 (hereinafter simply referred to as barrel) is a rotating cylindrical body having a ball mill-like structure as shown in FIG. It is pivotally supported via a magnetic seal 30. The other side wall is supported via a magnetic seal 30 by a shaft 12 that functions as a rotating shaft. A sputtering device 50 is held at the tip of the shaft 12 so as to face each other. Its orientation is not vertical, but has an inclination determined by the position of the powder bed caused by the rotation of the barrel 2, as will be explained later. This sputtering device 50 is operated by a high frequency current supplied through the shaft 12 from a power source (not shown).

The conduit 10 communicates with the reduced pressure heat treatment chamber 1 via a valve 121. This conduit 10 enters the barrel 2 horizontally from one side wall of the barrel 2 and curves downward again to reach near the bottom of the barrel 2. In this case, the curvature is not directed vertically downwards, but in a position where a fluidized bed of fine powder is created due to the rotation of the barrel 2. A pipe 19 is provided within the conduit 10 that communicates with the main exhaust system 6, the advanced exhaust system 7, and the inert gas supply source 31. Furthermore, the conduit 10 communicates via a valve 122 with a conduit 11 that supplies fine powder to the fluid jet mill 3 .

The barrel 2 is supported by support rolls 13. This support roll 13 is connected to the rotating shaft of a motor 14 via a belt 15, and rotates the barrel 2 by the rotation of the motor 14. The fluid jet mill 3 includes a propeller 2 that rotates at high speed by a motor 20.
1, and is configured so that the fine powder conveyed from the conduit 11 collides with its propeller 21. The discharge side of the fluid jet mill 3 communicates with a circulation pipe 23 provided with a valve 22 , which in turn communicates with the reduced pressure heat treatment chamber 1 . And below the valve 22 of the circulation pipe 23,
A powder filter 4 with a valve 24 is connected. This powder filter 4 is a trap that communicates with an exhaust system 26 via a cylindrical filter 25. (Formation of light-absorbing portions and bright portions) 90 g of the pearl mica pigment described above was put into the barrel 2 of the powder sputtering apparatus, and the pressure in the reduced-pressure heat treatment chamber 1 was reduced to 2×10 −5 Torr. Then, argon gas is gradually supplied from the pipe 31 to supply the pigment to the fluid jet mill 3, and the propeller 21
After being dispersed into primary particles by colliding with
to be collected. Reduced pressure heat treatment chamber 1 at 2 x 10-2 Torr
The pressure was reduced to 100° C. and heated to 100° C. with a heater to dry and degas the collected pigment for 30 minutes.

Next, the pigment was transferred into the barrel 2 which had been replaced with argon gas in advance, and sputtering using a bipolar magnetron was started under a reduced pressure of 2×10 −2 Torr while the barrel 2 was being rotated at 5 rpm. The conditions were: titanium was the target, power was 0.2 kW x 2, frequency was 13.56 MHz, and the temperature of the pigment was 200° C. or lower. Approximately 0.05% (approximately 2.0%) of the total surface area in 1 hour.
0% by weight) of titanium was coated. Repeat this process for 10
Repeated times to achieve a total of 95% (20% by weight) titanium coating.

After the coating was completed, argon gas was supplied into the barrel 2 from the pipe 31, and the resulting pigment was collected in the powder filter 4. (Evaluation of Pigment) The surface of the obtained pigment was subjected to Auger analysis and X-ray diffraction analysis, and the results are shown in FIGS. 5 and 6. From FIGS. 5 and 6, the obtained pigment has a titanium low-order oxide layer on the surface portion, and of course a titanium layer is also formed. That is, it is clear that when sputtered titanium atoms collide with the TiO2 layer, TiO2 is reduced and a lower oxide of titanium is formed.

When the obtained pigment was observed using a SEM, it was observed that titanium particles were formed on the surface in the form of scattered dots like islands, as shown in FIG. (Painting) The obtained pigment is made into acrylic/melamine clear paint (35% by weight of acrylic resin, 15% by weight of butylated melamine resin, 5% by weight of organic solvent, and a small amount of additives) so that the PWC is 10%. The mixture was thoroughly and uniformly stirred to prepare the metallic paint of this example. (Evaluation of paint) This metallic paint was applied to black and white hiding test paper using a 25 mil bar coater. and 140
A coating film was formed by baking and drying at ℃ for 30 minutes. The color tones of this coating film were measured on each surface of the white and black backgrounds, and the overall hiding power, color turbidity (transparency), metallic brilliance, and performance in which the color tone changes depending on the viewing angle (flip-flop property) were visually observed. A sensory evaluation was performed. The results are shown in Table 1. Table 1
It can be seen that this coating film develops a strong interference color, has a metallic luster, and has excellent hiding properties.

In other words, in order to develop an interference color, the TiO2 layer must be exposed at least partially, that a lower titanium oxide layer is formed when titanium collides, and that titanium It is clear from the results that the above pigment has a structure schematically shown in FIG. 1 from the results that it has a glittering appearance and that the surface is observed as dots under SEM. This color has a metallic color close to dark gray. [Example 2] A pigment formed in the same manner as in Example 1 except that the amount of titanium coated by sputtering was 2.0% by weight was used, and a paint was formed in the same manner as in Example 1, and the results were evaluated in the same manner. It is shown in Table 1. This color is an intermediate color between white and silver, similar to aluminum metallic. [Comparative Example 1] Using the pearl mica pigment before sputtering, it was made into a paint in the same manner as in Example 1 and evaluated. The results are shown in Table 1. [Comparative Example 2] Silver was deposited in island shapes on the pearl mica pigment used in Example 1 by electroless plating. The total projected area of deposited silver is 9% of the total surface area of the TiO2 layer.
It is 5%. This pigment was also made into a paint in the same manner as in Example 1,
Table 1 shows the results of the same evaluation.

[0028]

[Table 1] [Evaluation] From Table 1, the pigments of Examples have superior hiding power and strong interference color compared to Comparative Examples. It is clear that this is due to the effect of forming light absorbing parts and bright parts in a dotted manner on the surface of the TiO2 layer. In addition, if the amount of titanium coated by sputtering is less than 0.03% of the total surface area, the feeling of metallic brilliance will be poor and the hiding power will decrease, and if it exceeds 98%, the intensity of interference color will decrease and it will eventually become a gray achromatic color. It is also clear that this will happen.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a pigment used in the metallic paint of the present invention.

FIG. 2 is an explanatory diagram showing the optical effects of pigments used in the metallic paint of the present invention.

FIG. 3 is a front view of the powder sputtering apparatus.

FIG. 4 is a side view of the powder sputtering apparatus.

FIG. 5 is an Auger analysis chart of a pigment used in a metallic paint according to an example of the present invention.

FIG. 6 is an X-ray diffraction chart of a pigment used in a metallic paint according to an example of the present invention.

FIG. 7 is an SEM photograph showing the particle structure of a pigment used in a metallic paint according to an example of the present invention.

[Explanation of symbols]

Claims (1)

[Claims] 1. A transparent or translucent scale-like base material, a TiO2 layer coated on the entire surface of the base material, and a TiO2 layer formed on the entire surface of the base material.
2 Contains a pigment consisting of a light-absorbing part made of low-order titanium oxide formed in the form of dots on the surface of the TiO2 layer, and a bright part with metallic luster formed in the form of dots on the surface of the TiO2 layer. A metallic paint that is characterized by: