JPH0657807B2 - Pigment and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel pigment utilizing interference colors. The pigment of the present invention and the method for producing the same are particularly useful as coating materials for automobile exteriors.

[Prior Art] A metallic finish using a so-called metallic paint containing metal powder such as aluminum foil is often used for finish painting of automobiles, home appliances and the like. However, since aluminum foil has low brightness, it is difficult to use it as a light color. Therefore, in recent years, the use of pearl mica having a titanium dioxide layer coated on the surface of mica has been increasing.

As shown in FIG. 8, the pearl mica pigment has a structure in which the titanium dioxide layer 101 is coated on the surface of the mica 100. In this pearl mica, the incident light is reflected light A reflected on the surface of the titanium dioxide layer 101 and the titanium dioxide layer 10
It is divided into those that enter into 1. The light that has entered the titanium dioxide layer 101 is divided into reflected light B that is reflected at the interface with the mica 100 and transmitted light that passes through the mica 100. Various colors are generated due to the interference between the reflected light A and the reflected light B. For example, when the titanium dioxide layer 101 having a thickness of 120 to 135 nm is formed, blue is exhibited as the interference color between the reflected light A and the reflected light B.

However, a part of the transmitted light passes through the pearl mica pigment and is reflected on the surface of the base 102, and again passes through the pearl mica pigment and is emitted as reflected light C from the titanium dioxide layer 101 on the incident side. Since the reflected light C mixes with the reflected light B to become white light, there is a drawback that the interference between the reflected light A and the reflected light B is weakened accordingly, and the interference color is weakened.

Further, pearl mica has weak coloring power and hiding power, and is poor in practicality. For example, in the top metallic coating of automobiles, two coats and one bake are conventionally applied. However, a metallic coating using pearl mica usually requires a hiding film thickness of 200 μm or more, and in the conventional coating process, the color of the undercoat appears to be unclear. Therefore, uneven coating is noticeable, and repair coating is not easy. Then, for example, JP-A-5
As can be seen in Japanese Patent Laid-Open No. 9-215857, a color base layer close to the coating color of the pearl mica-containing paint is first formed, and then metallic coating is carried out with the pearl mica-containing paint. Is the current situation. However, this method requires the same number of color base paints as the coating color of the topcoat paint, and the number of coating processes also increases, resulting in increased man-hours and higher cost.

Colored mica pigments are known to solve this problem. As shown in FIG. 9, this pigment has an iron oxide layer 202 (F
e ₂ O ₃ etc.). According to this colored mica pigment, the interference color and the object color of iron oxide are colored,
Coloring power and hiding power are improved compared to pearl mica.

Further, in JP-A-60-60163, as shown in FIG. 10, a pigment in which a low-order titanium oxide layer 301 is first formed on a surface of mica 300 and a titanium dioxide layer 302 is further formed is disclosed in JP-A-60-60163. Japanese Patent Application Laid-Open No. 61-225264 discloses a paint using the pigment. According to such a pigment (hereinafter referred to as a black pearl pigment), the low-order titanium oxide layer 301 exhibits a black brown color, so that the transmitted light is absorbed and the reflected light C is reduced. Therefore, the interference between the reflected light A and the reflected light B is not disturbed, and a strong interference color is obtained, so that the coloring power and the hiding power are improved.

[Problems to be Solved by the Invention] With the above-described colored mica pigment, various colors can be obtained by changing the thickness of the titanium dioxide layer 201 and by changing the crystal form of the iron oxide layer 202. However, this pigment has a limitation that it is limited to the region from red to yellow because the object color of iron oxide is the basis for coloring.
In addition, iron oxide itself has turbidity in color, which is less clear than the interference color that is an optical color. Further, mica pigments modified with metals such as cobalt, copper, chromium and cadmium have been developed, but there are problems in terms of toxicity and durability, and none of them can be put to practical use.

In one method, the black pearl pigment develops a vivid color due to interference color, and has higher coloring power and hiding power than pearl mica. However, when used as a coating material for automobiles, the coloring power and the hiding power are still insufficient. That is, even when the black pearl pigment is contained to the limit of the physical properties of the coating film, the hiding film thickness is 80 to 1
It is as high as 00 μm, which is not practical.

Based on the above-mentioned current situation, the development of a pigment having a strong interference color, a high coloring power and a high hiding power is eagerly demanded especially in the field of overcoating for automobiles. The present invention is directed to answering this need.

[Means for Solving the Problem] The pigment of the present invention comprises a light-transmitting substrate such as mica and glass flakes, and a light-transmitting inorganic compound coating layer formed on the surface of the substrate as an aggregate of inorganic compound particles. And a scattered metal layer having metallic luster formed on the surface of the substrate on which the inorganic compound particles are not attached between the inorganic compound particles attached to the substrate.

Further, the method for producing the pigment of the present invention, a chromium treatment step of precipitating a chromium compound on a pearl mica surface having a titanium dioxide layer formed as an aggregate of titanium dioxide particles on the surface of mica to form a chromium-coated pearl mica, It consists of a plating process of electrolessly plating a metal or alloy on chrome-coated pearl mica, and in the plating process, metal particles are attached to the surface of the mica where no titanium dioxide particles are attached between the titanium dioxide particles attached to the surface of the mica. Are adhered to form a scattered metal layer.

The substrate may be in the form of particles or scales, and scale-like ones are particularly desirable. If it is scale-like, it can be oriented in a layer form in the applied wet coating film, and a coating film excellent in flip-flop property and hiding power can be formed. Typical examples of such a substrate are natural mica and synthetic mica, but other examples include glass flakes. In addition, its size is 0.5 when it is used for paint.
˜2 μm and average particle size of 50 μm or less are preferred.

This substrate has island-shaped metal layers formed in a dotted pattern on the surface, and has a metallic luster due to this metal layer. The light transmitted through the inorganic compound coating layer is divided into the light reflected by the metal layer and the light transmitted through the substrate, and a strong interference color is obtained by the light reflected by the metal layer. In addition, the light transmitted through the substrate provides an appropriate transparency similar to that of the pearl mica pigment. As a metal constituting such a metal layer, silver,
Gold, copper, palladium, nickel, cobalt, nickel-
Phosphorus, nickel-boron, nickel-cobalt-phosphorus,
Examples include metals or alloys such as nickel-tungsten-phosphorus, silver-gold, and cobalt-phosphorus.

A light-transmitting inorganic compound coating layer is formed on the surface of the substrate. The material of the inorganic compound coating layer is selected from titanium dioxide, iron oxide, aluminum hydroxide, chromium hydroxide and the like, but a material having a large refractive index is desirable, and titanium dioxide is most recommended. By changing the type and thickness of this inorganic compound coating layer, interference colors of various color tones can be obtained.

It is also possible to attach the metal in an island shape to the surface of the inorganic compound coating layer. By doing so, the intensity of the light reflected on the surface of the inorganic compound coating layer increases, so that a stronger interference color can be obtained.

To produce the pigment of the present invention, first a metal layer is formed on a substrate such as mica. The metal layer can be formed by a plating method such as electroplating or electroless plating, or a PVD method such as vapor deposition or sputtering.
In addition, the inorganic compound coating layer, an aqueous solution of an inorganic salt is attached to the surface of the substrate, and then a hydrous layer is deposited by hydrolysis,
It can be formed by a conventionally known method such as heating at a predetermined temperature in the beginning. For example, when a titanium dioxide layer is formed, the titanyl sulfate method or the titanium tetrachloride method described in JP-B-43-25644 can be used.

An example of the pigment of the present invention is a pigment in which a metal layer is formed between mica of pearl mica and a titanium dioxide layer. Therefore, it is conceivable to produce the pigment of the present invention using pearl mica as a starting material. However, it is usually difficult to form a metal layer on the surface of mica through the titanium dioxide layer. However, as a result of diligent research, the present inventors have found that a metal layer is formed on the surface of mica by passing through the titanium dioxide layer under special conditions, and a method of forming a metal layer by utilizing the phenomenon is found. Established The method will be described below.

First, a titanium dioxide layer having a predetermined thickness is formed on the surface of mica by a known titanyl sulfate method or the like. If commercial pearl mica is used, this step can be omitted.

Next, the pearl mica is subjected to chromium treatment.
That is, a chromium compound is deposited on the surface of the titanium dioxide layer. This step is a method of precipitating chromium hydroxide by hydrolyzing a solution of a soluble chromium salt such as chloride or sulfate as disclosed in JP-B-60-3345, or JP-A-59-59. As disclosed in Japanese Patent No. 78265, chromium is converted from a solution containing iron or manganese ions and chromium ions into hydroxide, carbonate,
A method of precipitating as a phosphate or a methacrylate complex can be used.

Next, the chrome-treated pearl mica is subjected to electroless plating. According to the experiments of the present inventors, as described in detail in Examples below, at this time, the plating metal did not deposit on the surface of the titanium dioxide layer, and the titanium dioxide layer formed as an aggregate of particles on the surface of the mica. Between the titanium dioxide particles
It was discovered that the titanium dioxide particles were deposited on the surface of the mica to which the titanium dioxide particles were not attached, in the form of dots. Although the reason for this has not been clarified, it is known that the electroless plating rate is significantly delayed by the presence of the chromium compound, and it is presumed that this suppressing action has a great influence. Thereby, the metal layer can be formed on the surface of the base made of mica. By the way, in the case of pearl mica treated with alumina, untreated pearl mica, etc., the plating metal is deposited on the surface of the titanium dioxide layer, and no scattered spots are deposited on the surface of the mica.

In addition, the suppression effect varies depending on the amount of the chromium compound deposited. For example, in the case of depositing silver as a metal layer by electroless plating, the composition is such that, when the weight of pearl mica is 100% by weight, the amount of chromium compound deposited converted to metallic chromium is 0.05 to 5% by weight. There is a need to.
If the amount of the chromium compound deposited is less than 0.05% by weight, silver is deposited on the surface of the titanium dioxide layer, and the desired interference color cannot be obtained. On the other hand, if it exceeds 5% by weight, the color of chromium appears and it tends to be yellow, which is not preferable. Especially 0.15-0.3
It is desirable to set it in the range of 0% by weight.

When silver is deposited as a metal layer on the surface of mica by using the above method, the weight of pearl mica is 100.
When the weight percent is set, silver can be deposited in the range of 1 to 100 weight percent. If it is less than 1% by weight, the interference color is weak and the coloring power is inferior, and if it is more than 100% by weight, silver particles of several μm in size are deposited on the surface of the titanium dioxide layer, and a desired color cannot be obtained. A range of 0.1 to 10% by weight is particularly desirable. Within this range, the grain size of the precipitated silver particles is 10 to 500.
In the range of nm, the maximum interference color is obtained.

[Operation] The operation of the pigment of the present invention will be described with reference to FIG.

The pigment of the present invention comprises a substrate 1 having a metal layer 10 on at least a part of the surface thereof, and a transparent inorganic compound coating layer 2 formed so as to cover the surface of the substrate 1. in this case,
The metal layers 10 are formed in a dotted pattern on the surface of the base 1 on which the inorganic compound particles are not attached.

When light is incident on this pigment, a part of the incident light is reflected by the surface of the inorganic compound coating layer 2 and becomes reflected light A1. Also,
The rest of the incident light passes through the inorganic compound coating layer 2 and the metal layer 1
The light is reflected at 0, passes through the inorganic compound coating layer again, and becomes reflected light A2. Here, the reflected light A1 and the reflected light A2 cause a predetermined interference according to the optical thickness (geometrical thickness × refractive index) of the inorganic compound coating layer 2 to emit an interference color. Further, in the present invention, since the metal layer 10 has a metallic luster, almost all the light that has passed through the inorganic compound coating layer 2 and reaches the metal layer 10 is totally reflected without any loss. Therefore, the reflected light A
Since the intensity of No. 2 is maximum, the interference with the reflected light A1 is also maximum, and a strong interference color is generated. This interference color can have various color tones simply by adjusting the thickness of the inorganic compound coating layer 2. Further, the metallic luster of the metal layer 10 can be seen from the surface. Therefore, this pigment is used as a metallic pigment having various color tones.

Ordinary color pigments develop color by absorbing light. Then, when the three primary colors are mixed, the mixed color approaches black infinitely.
That is, the saturation becomes lower as the primary colors are mixed. On the other hand, the pigment of the present invention is an achromatic color of metallic luster as an object color, which is colored by interference. Since the interference color is an optical color, when the three primary colors are mixed, the mixed color approaches white infinitely. That is, in the pigment of the present invention, the mixed color approaches the metal color of the metal layer without limit. The saturation does not decrease due to the mixture of primary colors. Therefore, the pigment of the present invention has a high saturation even when a plurality of colors are mixed and has a clear color tone.

[Effects of the Invention] Therefore, according to the pigment of the present invention, a strong interference color, which is not present in conventional mica pigments, is generated, and thus the coloring power is high and the hiding property is excellent. Only by adjusting the thickness of the inorganic compound coating layer It is extremely useful as a pigment for automobile top-coat paints because it can easily obtain various color tones and can realize metallic paint with a fresh color tone that has never been seen.

Further, in the conventional metallic paint, metallic paints of various colors are obtained by mixing an organic pigment and aluminum powder. Therefore, color separation may occur due to differences in the composition and electrical properties of the pigments. Further, in order to make the color pigment into a paint, a dispersion process using a ball mill or the like is indispensable, resulting in a large number of man-hours for making the paint. However, when the pigment of the present invention is used, even if a plurality of primary colors are mixed, the composition is the same, so that color separation does not occur. In addition, the dispersion process is not required, and the number of steps can be reduced significantly.

[Examples] Hereinafter, specific examples will be described.

As shown in FIG. 1, the pigment of the present embodiment includes a mica 1 as a substrate, a silver-made metal layer 10 formed on the surface of the mica 1 in an island shape, and an inorganic layer formed on the surface of the metal layer 10. It is composed of a titanium dioxide layer 2 as a compound coating layer. This pigment and the pigment of the comparative example will be described below in detail while explaining the production method. In the following, parts mean parts by weight and% means% by weight.

(Formation of Pearl Mica) Commercially available mica powder (thickness 0.5 to 1.0 μm, particle diameter 1
0 to 50 μm) was used to form a titanium dioxide layer by the titanyl sulfate method. Specifically, as titanium dioxide 67
% Mica powder to 750 m of titanyl sulfate aqueous solution containing 150%, and rapidly heating and boiling about 4.5
Boil under reflux for hours. The product is filtered, washed with water and pH
It was isolated by setting it to 5.0.

In addition, the amount of mica powder added was changed in 6 levels. To form a titanium dioxide layer, and 6 kinds of pearl mica having different thicknesses of the titanium dioxide layer were prepared. Each of the obtained pearl mica was embedded in a resin, sliced with a microtome, and then observed with a transmission electron microscope to measure the thickness of the titanium dioxide layer, and the color tone of each color is shown in Table 1.

(Chromium treatment) 100 g of each of the above pearl mica was suspended in distilled water 1, and 92 g of FeSO ₄ 7H ₂ O and KCr (SO were added while keeping the pH at 4.5 with a 2% NaOH aqueous solution.
₄ ) 100 m of an aqueous solution containing 17 g of ₂ 12H ₂ O
And 100 m of an aqueous solution containing 1.5 g of NaH ₂ PO ₄ 2H ₂ O were added at 50 ° C. for 60 minutes. Next, the pH was adjusted to 5.0 with 2% NaOH aqueous solution, and the mixture was further stirred for 60 minutes. Then, it was filtered, washed with water, and dried at 130 ° C. In this case, the chromium compound is precipitated as phosphate.

The amounts of the two kinds of aqueous solutions added to the suspension and the addition time were changed in four stages to obtain four kinds of chromium-treated pearl mica with different chromium compound precipitation amounts. With respect to each of the four types of chromium-treated pearl mica, the amount of chromium compound attached was measured by plasma elemental analysis. This chrome treatment was carried out in the same manner for the above 6 types of pearl mica, and a total of 24 types of chrome treated pearl mica were obtained. In addition, a sample not treated with chromium and a sample treated with alumina by a conventional method instead of the chromium treatment are illustrated for comparison, and each sample N
o. Is shown in Table 2.

(Formation of Metal Layer) 15 g of each sample shown in Table 2 was distilled water 450
m and suspended. Add silver solution (AgN
Distilled water was added to 50 g of O _{3 and} 50% aqueous 28% ammonia solution to make the total amount 1) 30 m at once, and then the mixture was stirred for 5 minutes. Next, formalin solution (35
20m of a formalin solution (9m) made up to a total volume of 40m with distilled water) was added all at once, and the mixture was stirred for 55 minutes. That is, electroless plating was performed. Then, after filtering, washing with water, and drying at 120 ° C., 36 kinds of pigments of Examples and Comparative Examples were obtained. This pigment sample No. Is the sample No. in Table 2. Substitute.

In addition, using silver solutions having AgNO ₃ contents of 100 g and 300 g, 7 kinds of samples marked with * in Table 2 were similarly electroless plated to obtain 14 kinds of pigments. The sample No. Is shown in Table 3. Also,
Of the black pearls disclosed in JP-A-61-225264, red, green and black ones are
Select the type and sample No. B-1, B-2, B
-3.

(Structure of pigment) Sample No. The structure of 5-C-3 pigment was investigated by a transmission electron microscope. The micrographs are shown in FIGS. These photographs are observed with the pigment peeled off at the interface between the titanium dioxide layer 2 and the mica 1. As schematically shown in FIGS. 6 and 7, it is observed that the titanium dioxide layer 2 is formed of titanium dioxide particles 20 having a height of 10 to 100 nm and a diameter of 2 to 5 nm arranged in an orderly manner. Also, silver particles 11 are attached to the titanium dioxide layer 2 side surface of the mica 1 from the upper half portion of FIG. 2 and FIG. 3 (the surface portion of the mica 1 from which the titanium dioxide layer 2 has been peeled off) in a scattered manner. It is observed that they are doing. In addition, a concentric empty space with nothing attached, which is considered to be a trace of titanium dioxide particles adhering to that area, was also observed, and the silver particles 11 were formed around the concentric empty space.
Are observed to be deposited. From this, the sixth
As schematically shown in FIG. 7 and FIG. 7, it is presumed that silver particles 11 are deposited on the surface of the mica 1 between the titanium dioxide particles 20 to form the dotted metal layer 10. .

(Coating) Using the above-mentioned 53 kinds of samples and 6 kinds of pearl mica shown in Table 1 which are not subjected to chrome treatment and silver plating, the following composition (solid content other than organic solvent) is mixed to obtain a high-speed dispersion. Each base paint was prepared by stirring and dispersing with.

Sample pigment 3.20% Acrylic resin 18.78% Melamine resin 8.05% Anti-settling agent 1.96% Additive 0.42% Organic solvent 67.59% Total 100.00% The acrylic resin is as follows. Monomer composition, Mw
= 27,000, Mn = 12000 resin was used.

Styrene 20.0% n-Butyl methacrylate 15.0% Ethylhexyl methacrylate 20.0% Stearyl methacrylate 15.0% Butyl acrylate 13.5% Hydroxyethyl methacrylate 15.0% Methacrylic acid 1.5% Total 100.0% Melamine resin Is an n-butylated melamine resin (“u-va
n20SE ”manufactured by Mitsui Toatsu Chemicals, Inc., and an amide-based wax was used as an anti-settling agent.

The PWC of mica pigment is 10%.

(Color measurement) Each paint obtained from each sample pigment was applied on a gray intermediate coating film surface with a bar coater so that the dry film thickness was 15 μm, and baked and dried. The color tone of the obtained coated surface is measured by a colorimeter (“SM-3” Suga Test Instruments Co., Ltd.)
(Manufactured) and the Lab is shown in Table 4. The colorimetry was performed on two types, MCH corresponding to the color tone viewed from the front and CH corresponding to the color tone viewed from the oblique direction.

(Hiding power) Each coating material was applied to a black-and-white hiding test paper while gradually changing the film thickness, and the hiding film thickness at which the white and black cannot be distinguished is shown in Table 4.

(Physical properties of coating film) A copper plate on which an electrodeposition coating film and an intermediate coating film are formed is coated with each base coating material by air spraying so that a simple film thickness is 15 μm, and after a few minutes of flash time, wet. On-wet, an acrylic-melamine resin-based clear paint was applied by air spray to a dry film thickness of 35 μm. And it baked at 140 degreeC for 23 minutes, and produced the test piece. A water resistance test and a weather resistance test were conducted on this test piece, and the results are shown in Table 4. The composition of the clear paint and the acrylic resin used for the clear paint is shown below. Water resistance test is 1 in 40 ° C warm water
Two kinds of tests were carried out: a test of dipping for 0 days and a test of dipping in hot water of 80 ° C. for 10 hours, and the appearance of the coated surface was visually judged. The weather resistance test is 500 with a QUV tester.
A time-accelerated test was performed, and the color difference between after the test and before the test was measured.

[Clear coating composition] Acrylic resin 38.25% Melamine resin 16.40% Additives 1.24% Organic solvent 45.11% Total 100.00% [Acrylic resin composition] Styrene 30.0% n-Butyl methacrylate 15.0 % Ethyl acrylate 20.0% Butyl acrylate 17.5% Hydroxyethyl methacrylate 15.0% Acrylic acid 2.5% Total 100.0% Mw = 16000, Mn = 7000 (Evaluation) Pigment of this example (C series) Then PWC = The black and white hiding film thickness is 21 to 48 μm at 10%, whereas the black pearl (B series) is 93 to 101 μm.
m, Pearl mica (M series) 320-410μ
m. That is, it is clear that the pigment of the present invention is excellent in coloring power and hiding power.

Further, the color difference of the pigment of this example after the weather resistance test is equivalent to that of pearl mica, and the weather resistance is not deteriorated due to the chrome treatment and silver plating, and excellent performance is maintained. Regarding the water resistance and weather resistance, it is clear that the C series pigments are superior to the A series pigments that have not been treated with chromium, and that these properties are improved by the chromium treatment.

It can be seen that the C-series pigment has a large difference between MCH and CH and exhibits favorable flip-flop characteristics. Further, as is clear from the black-and-white hiding film thickness of the D series pigments, it can be seen that the hiding film thickness decreases as the silver plating amount increases. This is because, of the light incident on the pigment, the light that is totally reflected by the silver plating layer increases, and the interference increases.

Pigment plated with silver on pearl mica not treated with chromium and pearl mica treated with alumina (A series)
Then, the flip-flop characteristic is smaller and the concealment film thickness is larger than that of the chrome-treated one. In these pigments, although illustration is omitted, as a result of microscopic observation, silver particles were precipitated on the surface of the titanium dioxide layer.

That is, it can be said that the pigment of this example is sufficiently in a practical range even when it is used as a top coating material for automobiles.

(Color mixing) Among the pigments of the above-mentioned example, 1-C-3 (silver color),
2-C-3 (gold), 3-C-3 (red), 5-C-3
(Blue) and 6-C-3 (green) were selected to prepare coating materials in the same manner as in the examples. Then, each paint is mixed so that the pigments have the ratio shown in Table 5, and each paint is applied to art paper with a 25 mil applicator and baked. Dried. The color tone was measured in the same manner as in Example, and the results are shown in Table 5.

As described above, with the pigment of the present embodiment, pigments of various color tones can be obtained only by changing the thickness of the titanium dioxide layer, and a color tone over the entire color gamut can be obtained only by mixing them. Since each color can be achieved only by the interference color, the color mixture becomes an additive color mixture, and a clear color tone without turbidity can be obtained. Further, since each color can be obtained only with the mica pigment, problems such as color separation do not occur. Further, when the material is made into a paint, it is dispersed only by stirring, so that a dispersing step which requires a great number of man-hours as in the past is not required, and the man-hour for making a paint is significantly reduced.

[Brief description of drawings]

1 to 7 relate to a pigment according to an embodiment of the present invention.
The figure is a schematic sectional view thereof, FIGS. 2, 3, 4, and 5 are micrographs showing the crystal structure thereof, FIG. 6 is an enlarged sectional view of an essential part thereof, and FIG. 7 is an essential part thereof. It is an enlarged plan view.
FIG. 8, FIG. 9 and FIG. 10 are schematic sectional views of conventional pigments. 1 ... Mica (base material) 2 ... Titanium dioxide layer (inorganic compound coating layer) 10 ... Metal layer, 11 ... Silver particles 20 ... Titanium dioxide particles

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutoshi Minohara 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP 61-16968 (JP, A) JP 56- 120771 (JP, A)

Claims (2)

[Claims] 1. A light-transmitting inorganic scaly substrate having no coating layer such as mica and glass flakes, and a light-transmitting inorganic compound coating adhered and formed on the surface of the substrate as an aggregate of inorganic compound particles. A metal layer having a metallic luster formed on the surface of the substrate on which the inorganic compound particles are not attached between the inorganic compound particles attached to the substrate. Characteristic pigment. 2. A chromium treatment step of precipitating a chromium compound on a surface of a pearl mica having a titanium dioxide layer adhered and formed as an aggregate of titanium dioxide particles on the surface of mica to obtain a chrome mica coated with chrome, and the pearl mica coated with chrome. And a plating step of electrolessly plating a metal or an alloy on the surface of the mica in which the titanium dioxide particles are not adhered between the titanium dioxide particles adhered to the surface of the mica. A method for producing a pigment, characterized in that particles are attached to form a scattered metal layer.