JP4789508B2 - Method for producing silver-colored pearlescent pigment - Google Patents

Description

  The present invention relates to a silver-colored pearlescent pigment and a method for producing the same, and more particularly, to a pearlescent pigment having a silver-colored pearlescent pigment and a method for producing the same.

  Conventionally, pearl mica pigments in which titanium dioxide is coated on the surface of mica or silica are known. This pearl mica pigment exhibits a pearly luster due to light interference utilizing the refractive index of the titanium dioxide layer, and various interference colors can be developed by changing the thickness of the titanium dioxide layer. Widely used as a paint.

  However, as shown in FIG. 5, the conventional pearl mica pigment is obtained by coating the surface of mica 23 having a thickness of 0.2 to 1.0 μm, for example, with a titanium oxide coating layer 14 having a thickness of 80 to 400 nm. there were.

  Therefore, since the conventional pearl mica pigment 40 is thick, it cannot be densely oriented in the top coat film or the pace paint film, and the light scattering at the edge of the pigment particle becomes strong.・ The design effect was just one step away from the “flop effect” (an effect in which the color tone changes slightly depending on the angle).

  On the other hand, Patent Document 1 discloses that flaky particles having a diameter in a plane direction of 3 to 100 μm and a thickness of 0.05 to 1 μm obtained by heat-treating a synthetic mica powder once at 600 to 1350 ° C. A pearlescent pigment for use in paints, inks, cosmetics, etc., coated with rutile titanium dioxide has been proposed.

  Further, in Patent Document 2, a pearly luster obtained by using an alkali metal or alkaline earth metal-containing plate boehmite as a base material instead of mica flakes and coating this specific boehmite with a metal oxide such as titanium oxide. Pigments have been proposed. Here, the specific boehmite used as the substrate has a thickness of 150 to 200 nm and an aspect ratio in the range of 27 to 40.

JP 9-194754 A JP 2001-207077 A

  However, the pearl luster pigment proposed in Patent Document 1 requires heat treatment to smooth the surface of the synthetic mica, and the manufacturing operation becomes complicated. Furthermore, there is no indication in Patent Document 1 about the thickness of the titanium oxide film coated on the smoothed synthetic mica. When the titanium oxide film is thick, the thickness of the obtained pearl luster pigment itself As a result, the edge light scattering of the pigment particles becomes strong, which makes it difficult to obtain the “flip-flop effect” and may lack design properties. Furthermore, if the titanium oxide film is too thick, a silver color cannot be developed, and a pigment having a white pearl color cannot be obtained.

  Moreover, in the pearl luster pigment proposed in Patent Document 2, since the base material has an aspect ratio of 40 or less, even if the base material is coated with titanium oxide, the light interference effect is hardly exhibited. Furthermore, Patent Document 2 does not provide any information about the thickness of the titanium oxide film. As described above, when the titanium oxide film is thick, the thickness of the obtained pearlescent pigment itself is also increased. Since the thickness of the obtained pearl luster pigment itself is increased, the edge light scattering of the pigment particles is increased, so that it is difficult to obtain the “flip-flop effect” and the design property may be lacking. Furthermore, if the titanium oxide film is too thick, a silver color cannot be developed, and a pigment having a white pearl color cannot be obtained.

  The present invention has been made in view of the above problems, and provides a flaky pearlescent pigment having a high flip-flop effect, silver colorability, and capable of being densely present in a coating film, and a method for producing the same. provide.

  The method for producing a silver-colored pearlescent pigment of the present invention has the following characteristics.

(1) The surface of the flaky substrate is coated with silica to form a coating composition, and the coating composition is baked at a temperature of 500 ° C. or higher and 700 ° C. or lower. A release composition is obtained by peeling from the surface of the substrate, and a coating layer made of titanium oxide is formed on the surface of the release composition having a major axis of 5 to 100 μm and an aspect ratio of 50 or more , whereby the coating layer is formed. The pigment precursor is baked at a temperature of 700 ° C. or higher, and a silver-colored pearlescent pigment having a coating layer having a thickness of 40 to 100 nm is produced.

Silica is coated on the surface of the flaky substrate to form a coating composition, the coating composition is baked at a temperature of 500 ° C. or higher and 700 ° C. or lower, and the surface layer coating in the coating composition is further flaky substrate The peeling composition obtained by peeling from the surface becomes a scaly substrate having a very thin thickness and smoothness. The pigment obtained by coating the scale-like substrate with titanium oxide and calcining at 700 ° C. or higher is a silver-colored pearlescent pigment having a high aspect ratio, extremely thin, high smoothness and high flip-flop effect. It becomes. By setting the coating layer made of titanium oxide to the specific thickness, a white pearl-colored pearlescent pigment having a silver color can be obtained for the first time. Furthermore, the silver color-forming pearlescent pigment in which the coating layer is formed on a scaly substrate having the specific major axis and aspect ratio (ratio of thickness and length in the longitudinal direction) has an extremely thin thickness. When the pigment is contained in the coating film with the same content PWC (pigment weight content: solid content with respect to the resin of the coating material), the number of pigments in the coating film increases and can be made dense. Thereby, a coating film having a higher “flip-flop effect” can be formed.

  (2) In the method for producing a silver-colored pearlescent pigment according to (1), the flaky substrate is selected from natural mica, synthetic mica, glass flake, silica flake, alumina flake, and barium sulfate.

  The flaky substrate has good interfacial peelability from the material that becomes the scaly substrate.

  According to the present invention, a silver-colored pearlescent pigment having a high “flip-flop effect” and capable of being densely present in the coating film can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Silver color pearlescent pigment]
The configuration of the silver-colored pearlescent pigment of a preferred embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the silver-colored pearlescent pigment 20 of this embodiment is formed by coating a scaly substrate 13 with a coating layer 14 made of titanium oxide.

  The scale-like base material 13 has a thickness of 100 to 200 nm, preferably 100 to 150 nm. When the thickness of the scaly substrate 13 exceeds 200 nm, the denseness in the coating film is reduced, and the flip-flop effect is further reduced. On the other hand, it is difficult to obtain a substrate having a thickness of less than 100 nm as a substrate by a manufacturing method described later.

  Further, the major axis (length in the longitudinal direction) of the scaly substrate 13 is 5 to 100 μm, and particularly in the case of a pigment used for a paint for vehicles, the major axis of the scaly substrate 13 is preferably 5 to 15 μm. . When the major axis is less than 5 μm, a pigment having a high light interference effect cannot be obtained. When the major axis exceeds 100 μm, a part of the pigment may protrude from the coating film, and the coating film appearance deteriorates. In the case of a pigment used for a paint for vehicles, if the major axis of the scaly substrate 13 exceeds 15 μm, there is still a possibility that a part of the pigment protrudes from the top coat film or the base coat film to impair the appearance of the paint film. is there.

  The scale-like substrate 13 has an aspect ratio (ratio of thickness to major axis) of 50 or more, preferably 50 or more and 500 or less, more preferably 50 or more and 300. When the aspect ratio is less than 50, a pigment having a high light interference effect cannot be obtained. On the other hand, when the aspect ratio exceeds 500, a part of the pigment protrudes from the coating film, which may impair the appearance of the coating film. is there.

The material of the scaly substrate 13 is silica (SiO ₂ ) or mica, and mica is also preferably synthetic mica, and this synthetic mica is preferably obtained by heat-treating synthetic mica at 600 to 1350 ° C. and smoothing. Any of the above materials can form a scaly substrate having a high surface smoothness and a high aspect ratio, and a silver-colored pearlescent pigment having a high “flip-flop effect” can be obtained. In view of the simplicity of the manufacturing operation, silica that does not require a heat treatment step is more preferable as the scaly substrate 13.

On the other hand, the coating layer 14 is made of titanium oxide (TiO ₂ ), and the thickness of the coating layer 14 is 40 to 100 nm. When the thickness of the coating layer 14 is less than 40 nm, a silver color that is an interference color cannot be obtained. On the other hand, when the thickness exceeds 100 nm, the color changes from yellow to red and it is difficult to develop a silver color. .

[Method for producing silver-colored pearlescent pigment]
A method for producing a silver-colored pearlescent pigment according to a preferred embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 2, first, a surface layer film 12 made of a raw material to be a scaly substrate is formed on the surface of a flaky substrate 10, and the obtained coating composition is 700 ° C. or lower, preferably 500 ° C. to 650 ° C. Is fired at a low temperature (S100). Next, the surface layer film 12 is peeled from the flaky substrate 10 of the coating composition to obtain a scaly substrate 13 which is a peeling composition (S102). A coating layer 14 made of titanium oxide (TiO ₂ ) is formed on the surface of the obtained scaly substrate 13 to generate a pigment precursor (S104). Next, the pigment precursor is baked at a high temperature of 700 ° C. or higher, preferably 700 ° C. to 800 ° C. (S106). Further classification is performed to obtain a silver-colored pearlescent pigment 20 having an average particle diameter of 5 to 100 μm.

  Here, the thickness, the major axis, the aspect, and the thickness of the coating layer 14 of the scaly substrate 13 are as described above, and the description thereof is omitted.

  The flaky substrate 10 is rich in smoothness, and the plate size of the particles is preferably in the range of 50 to 800 μm in terms of laser diameter. When the particle size is 50 μm or less, the particle size of the exfoliated scaly substrate 13 is too small, and even when the interference gloss is sufficiently exhibited, the titanium oxide is difficult to exfoliate from the flaky substrate 10. Further, when the size of the plate shape of the particles is 800 μm or more, the interference gloss of the scaly substrate 13 can be sufficiently exerted, but the particles of the exfoliated scaly substrate 13 become too large and the mechanical strength thereof is increased. However, the usage is limited.

  The particle size of the flaky substrate 10 is more preferably in the range of 100 to 700 μm. When a flaky substrate having a thickness of 100 μm or less is used, particles of a peeling composition described later tend to be fine, and the coloration of high iris interference colors tends to be slightly weakened. Further, when the particle size of the flaky substrate 10 is larger than 700 μm, although the coloring of the high iris interference color by the particles of the peeling composition becomes strong, there is a tendency for the particles to feel rough. Furthermore, the particle size of the flaky substrate 10 is more preferably 100 to 300 μm, and it has a high gloss and is easy to peel off.

  Specifically, examples of the flaky substrate 10 that easily falls within the above-described particle diameter range include natural mica, synthetic mica, glass flake, silica flake, alumina flake, and barium sulfate. The glass flake is relatively easy to control its shape and the degree of surface smoothness, and further, the material that forms the uniform scaly substrate 13 on the surface thereof has a thickness of 100 to 200 nm as described above. It is a preferable material to select as the flaky substrate 10 because it is relatively easy to coat and the interface flaking between the glass flakes and the flaky substrate 13 is easy.

  Although the thickness of the particles of the flaky substrate 10 is not particularly defined, a range of 0.1 μm to 10 μm is preferable. When the thickness of the particles is 0.1 μm or less, the periphery of the flaky substrate 10 is curled roundly, and the periphery of the coated surface layer film 12 is also curled, and the scaly substrate 13 having smoothness cannot be obtained. On the other hand, when the thickness of the particles is 10 μm or more, the productivity of the scaly substrate 13 decreases.

For example, in order to obtain the scaly substrate 13 made of silica, a solution obtained by adding an acid such as hydrochloric acid to a sodium silicate (water glass) aqueous solution and neutralizing it is applied to the surface of the flaky substrate 10. Silica gel is deposited on the surface of the flaky substrate 10 to form a coating composition. Thereafter, the surface coating 12 of silica (SiO ₂ ) can be formed on the surface of the flaky substrate 10 by baking the coating composition at a low temperature of 700 ° C. or lower. Next, the baked coating composition in which the surface coating 12 of silica (SiO ₂ ) is formed on the surface of the flaky substrate 10 is immersed in an alkali (pH 8 or more), and the surface coating 12 made of silica from the flaky substrate 10. To peel off. Thereby, the scaly base material 13 excellent in smoothness without curling can be obtained.

  Further, in order to obtain the scaly substrate 13 made of synthetic mica, fluorine mica such as fluorine phlogopite, fluorine tetrasilicon mica, fluorine teniolite, and their isomorphous substitutes is melted, and the melt is flaky substrate 10. Is applied to the surface of the coating to form a coating composition. Thereafter, the surface coating 12 of synthetic mica can be formed on the surface of the flaky substrate 10 by baking the coating composition at a low temperature of 700 ° C. or lower. Next, the baked coating composition in which the surface coating 12 of synthetic mica is formed on the surface of the flaky substrate 10 is immersed in an alkali (pH 8 or more), and the surface coating 12 made of synthetic mica is peeled from the flaky substrate 10. Let Thereby, the scaly base material 13 excellent in smoothness without curling can be obtained.

  Further, for example, by applying hydrolysis of a soluble aqueous solution of tin oxide-titanium tetrachloride or a soluble aqueous solution of titanyl sulfate or titanium tetrachloride or titanium alcoholate to the surface of the flaky substrate 13, the flaky substrate 13 A coating layer 14 made of titanium oxide can be formed on the surface of the film. The pigment precursor on which the coating layer 14 is formed can be fired at a high temperature to obtain the pearlescent pigment 20.

  FIG. 3 shows an example of a plurality of coating films. For example, an electrodeposition coating film (not shown) is formed on a substrate such as a steel plate, and the intermediate coating film 30 is formed on the electrodeposition coating film. A white base coating film 32, a pearlescent pigment-containing base coating film 34, and a clear coating film 36 are sequentially laminated.

  The silver coloring pearlescent pigment 20 produced by the above-described production method is an ultrathin pigment. Therefore, the pearlescent pigment-containing base coating 34 in the multi-layered coating as shown in FIG. Will exist. Thereby, a multilayer coating film having a high silver coloring property and a high flip-flop effect can be obtained.

  Below, the silver coloring pearl luster pigment of this invention is demonstrated using an Example.

Example 1.
Add 1.0 kg of glass flakes to 20 liters of clean water, and while stirring, pass 50 liters of mash colloider made by Masuyuki Sangyo Co., Ltd. twice and crush it. 0.02% hexametaphosphoric acid aqueous solution was added to make the total volume 45L.

  Stir with a propeller stirrer, and after leaving still for 5 minutes, transfer the supernatant to another container, repeat this operation three times, classify large particles of 0.1 mm or more, Nodal classification was performed using a mesh (445 μm) and a 65 mesh (203 μm), and 150 g of a particle size of 40 to 65 mesh was obtained.

Next, 1.5 L of clean water was added to 150 g of classified glass flakes, and the mixture was stirred and heated to 80 ° C., and then adjusted to pH = 9 using caustic soda. Thereafter, 200 g of a sodium silicate solution (20% as SiO ₂ ) was gradually added dropwise, and at the same time, the pH was adjusted with dilute hydrochloric acid to maintain pH = 9. It was washed with water after completion of the dropwise addition and dried at 150 ° C. after filtration. The obtained coating composition was an aggregate having a particle size of 0.01 μm.

  The dry powder was fired at 700 ° C. for 1 hour in the air. A 10 percent aqueous caustic soda solution was added to the calcined powder to adjust the pH to 11, and left to stand still. The powder floating in the supernatant was classified by a decantation method, and the classified powder was filtered and washed with water. The thickness of the washing classification powder (silica powder) obtained at this time was 200 nm, the major axis was 15 μm, and the aspect ratio was 75.

  To 100 g of this water-washed classification powder (silica powder), 1.5 L of clean water was added and stirred, and 6 g of hydrochloric acid and 1.5 g of tin chloride were added to adjust the liquid temperature to 80 ° C. and pH = 2.0. To this, 360 g of titanium tetrachloride (16% as Ti) was gradually added dropwise, and at the same time, adjustment was made using caustic soda to maintain pH = 2.0. After completion of the dropwise addition, it was washed with water, filtered and dried at 150 ° C. This dry powder was fired in the atmosphere at 700 ° C. for 2 hours. The thickness of the titanium oxide coating layer of the silver coloring pearlescent pigment obtained at this time was 70 nm when calculated from the above production example.

Example 2
Add 1.0 kg of glass flakes to 20 liters of clean water, and while stirring, pass 50 liters of mash colloider made by Masuyuki Sangyo Co., Ltd. twice and pulverize. 0.02% hexametaphosphoric acid aqueous solution was added to make the total volume 45L.

  Stir with a propeller stirrer, and after leaving still for 5 minutes, transfer the supernatant to another container, repeat this operation three times, classify large particles of 0.1 mm or more, and use the supernatant for standard section 100 Nodules were classified using a mesh (154 μm) and a 200 mesh (77 μm) to obtain 100 g of a particle size of 40 to 65 mesh.

Next, 1.5 L of clean water was added to 150 g of classified glass flakes, and the mixture was stirred and heated to 80 ° C., and then adjusted to pH = 9 using caustic soda. Thereafter, 130 g of sodium silicate solution (20% as SiO ₂ ) was gradually added dropwise, and at the same time, the pH was adjusted with dilute hydrochloric acid in order to maintain pH = 9. It was washed with water after completion of the dropwise addition and dried at 150 ° C. after filtration. The obtained coating composition was an aggregate having a particle size of 0.01 μm.

  The dry powder was fired at 700 ° C. for 1 hour in the air. A 10 percent aqueous caustic soda solution was added to the calcined powder to adjust the pH to 11, and left to stand still. The powder floating in the supernatant was classified by a decantation method, and the classified powder was filtered and washed with water. The thickness of the washing classification powder (silica powder) obtained at this time was 100 nm, the major axis was 5 μm, and the aspect ratio was 50.

  To 100 g of this water-washed classification powder (silica powder), 1.5 L of clean water was added and stirred, and 6 g of hydrochloric acid and 1.8 g of tin chloride were added to adjust the liquid temperature to 80 ° C. and pH = 2.0. To this, 360 g of titanium tetrachloride (16% as Ti) was gradually added dropwise, and at the same time, adjustment was made using caustic soda to maintain pH = 2.0. After completion of the dropwise addition, it was washed with water, filtered and dried at 150 ° C. This dry powder was fired in the atmosphere at 700 ° C. for 2 hours. The thickness of the titanium oxide coating layer of the silver color developing pearl luster pigment obtained at this time was 40 nm when calculated from the above production example.

Example 3
Add 1.0 kg of glass flakes to 20 liters of clean water, and while stirring, pass 50 liters of crushed natural mica twice through a mascolloider manufactured by Masuyuki Sangyo Co., Ltd., and transfer to a plastic tank. 0.02% hexametaphosphoric acid aqueous solution was added to make the total volume 45L.

  Stir with a propeller stirrer, and after standing for 5 minutes, transfer the supernatant to another container, repeat this operation three times, classify large particles of 0.1 mm or more, and use the supernatant for standard section 10 The particles were classified using a mesh (800 μm) and a 65 mesh (203 μm) to obtain 150 g of a particle size of 10 to 65 mesh.

Next, 1.5 L of clean water was added to 150 g of classified glass flakes, and the mixture was stirred and heated to 80 ° C., and then adjusted to pH = 9 using caustic soda. Thereafter, 180 g of sodium silicate solution (20% as SiO ₂ ) was gradually added dropwise, and at the same time, the pH was adjusted with dilute hydrochloric acid in order to maintain the pH = 9. It was washed with water after completion of the dropwise addition and dried at 150 ° C. after filtration. The obtained coating composition was an aggregate having a particle size of 0.01 μm.

  The dry powder was fired at 700 ° C. for 1 hour in the air. A 10 percent aqueous caustic soda solution was added to the calcined powder to adjust the pH to 11, and left to stand still. The powder floating in the supernatant was classified by a decantation method, and the classified powder was filtered and washed with water. The thickness of the water-washed classification powder (silica powder) obtained at this time was 200 nm, the major axis was 60 μm, and the aspect ratio was 300.

  To 100 g of this water classification powder (silica powder), 1.5 L of clean water was added and stirred, and 6 g of hydrochloric acid and 1.2 g of tin chloride were added to adjust the liquid temperature to 80 ° C. and pH = 2.0. To this, 500 g of titanium tetrachloride (16% as Ti) was gradually dropped, and at the same time, adjustment was made using caustic soda to maintain pH = 2.0. After completion of the dropwise addition, it was washed with water, filtered and dried at 150 ° C. This dry powder was fired in the atmosphere at 700 ° C. for 2 hours. The thickness of the titanium oxide coating layer of the silver coloring pearlescent pigment obtained at this time was 100 nm when calculated from the above production example.

Comparative Example 1
As a pigment, “SC-100” (manufactured by Nippon Koken Co., Ltd., trade name “ultimica”) was used.

Comparative Example 2
As a pigment, “SD-100” (manufactured by Nippon Koken Co., Ltd., trade name “ultimica” type name) was used.

Comparative Example 3
As the pigment, “SB-100” (manufactured by Nippon Koken Co., Ltd., trade name “ultimica” type name) was used.

Comparative Example 4
As a pigment, “SE-100” (manufactured by Nippon Koken Co., Ltd., trade name “ultimica”) was used.

Comparative Example 5
As the pigment, “SE-100” (manufactured by Nihon Koken Co., Ltd., trade name “Ultimica”), which is different from the pigment of Comparative Example 4 in the major diameter, aspect ratio, and coating layer thickness of the base material, was used.

Comparative Example 6
As the pigment, a solid color pigment “# 040” made by Toyota Motor which is not a bright pigment was used.

  The pigments of Examples 1 to 3 and Comparative Examples 1 to 6 obtained above were mixed with acrylic melamine paint at 10% PWC (pigment weight content) to form a base paint.

  As shown in FIG. 3, an intermediate coating film 30 and a white base coating film 32 are formed on the steel plate, and the base coating is applied to the white coating base film 32 to a thickness of about 15 μm. A base coating film 34 was formed by coating, an acrylic melamine-based clear paint was applied to a thickness of about 30 μm without baking, and a clear coating film 36 was formed, followed by baking at 140 ° C. for 30 minutes. Thus, the evaluation coating plate was obtained and the evaluation shown below was performed.

[Measurement evaluation of L value]
Using a multi-angle colorimeter “X-Rite MA68II” (manufactured by X-Rite), L15 value is measured at an incident angle of 15 ° and a light receiving angle of 15 °, and an L25 value is measured at an incident angle of 25 ° and a light receiving angle of 25 °. The Δ value of “L15”-“L25” is “L15-L25” and is shown in FIG. As the value of “L15−L25” shown in FIG. 4 increases, the flip-flop effect increases.

[Bright particle BS]
Using a computer graphic (CG) display device disclosed in Japanese Patent Application Laid-Open No. 2005-77202, the ratio of the number of unit areas for each brightness level in a predetermined area was calculated, and the luminous particle property was measured. As shown in FIG. 6, the CG display device 100 measures the variable angle spectral reflectance of a sample having a predetermined area to which the paint color of the glittering material-containing paint is applied, and acquires the variable angle spectral reflectance. The reflectance measuring device 52, the variable angle spectral reflectance storage unit 54 that stores the variable angle spectral reflectance acquired by the variable angle spectral reflectance measuring device 52, and the sample coated with the paint color of the glittering material-containing paint. A light luminance measuring device 56 that measures light luminance with a camera to acquire image data and calculates the light luminance, a light luminance storage unit 58 that stores the light luminance measured by the light luminance measuring device 56, and a shape of the object The stored object shape storage unit 74, the variable spectral reflectance stored in the variable spectral reflectance storage unit 54, the light intensity stored in the light luminance storage unit 58, and the object shape storage unit 74. CG with CG Composed of CG display processor 80. which may perform processing so as to be displayed.

  As the variable angle spectral reflectance measuring device 52, for example, a variable angle spectral reflectance system manufactured and marketed by a generally known “Murakami Color Research Laboratory Co., Ltd.” or the like can be used. The light luminance measuring device 56 mainly includes a light source, a CCD (Charge Couple Device) camera, and a computer connected to the CCD camera.

  In the computer graphic (CG) display device described above, the rendering unit 70 acquires the CG display paint color stored in the CG display paint color storage unit 68 and the object shape stored in the object shape storage unit 74, CG display is performed based on the paint color for CG display. In the CG display process, the rendering unit 70 uses the CG display paint color, the object shape, and the illumination environment information for designating the illumination condition and the illumination environment to determine the paint material-containing paint color intended by the designer through the three-dimensional CG. A color image of the automobile body is generated and displayed on a CG display unit 72 such as a color display or a color printer. The CG display paint color calculated as described above is plotted in FIG.

  In addition, Table 1 shows the characteristics of the pigments of Examples and Comparative Examples.

  As shown in Table 1 and FIG. 4, the pearlescent pigment formed by forming a coating layer made of titanium oxide with a thickness of 40 to 100 nm on a scaly base material having a high aspect ratio has a high “L15-L25”. It can be seen that the flop effect is high and the glitter particle property is also high.

  The silver-coloring pearlescent pigment of the present invention is effective for any use as long as it requires a coating film having a silver-colored pearly luster, for example, for forming a coating film for home appliances and a coating film for vehicles. In particular, it is useful for forming a coating film on a vehicle exterior for making a design stand out.

It is a figure explaining one aspect | mode of a structure of the silver coloring pearl luster pigment of this invention. It is a flowchart explaining the process of 1 aspect of the manufacturing method of the silver coloring pearl luster pigment of this invention. It is a figure explaining an example of the multilayer coating film containing the silver color development pearl luster pigment of this invention. It is the figure which measured the L15-L25 and glitter particle property, and plotted the result with respect to the silver coloring pearl luster pigment of the Example of this invention, and the other pigment used for the comparative example. It is a figure explaining the one aspect | mode of the structure of the conventional pearl mica. It is a figure explaining the structure of the computer graphic (CG) display apparatus which measures a luminous particle property.

Explanation of symbols

  10 flaky substrate, 12 surface coating, 13 scaly substrate, 14 coating layer, 20 pearlescent pigment.

Claims (2)

Coating the silica on the surface of the flaky substrate to form a coating composition;
Firing the coating composition at a temperature of 500 ° C. or higher and 700 ° C. or lower;
The surface coating in the coating composition is peeled off from the surface of the flaky substrate to obtain a peeling composition,
Forming a coating layer made of titanium oxide on the surface of the release composition having a major axis of 5 to 100 μm and an aspect ratio of 50 or more ,
A method for producing a silver-colored pearlescent pigment comprising firing a pigment precursor on which the coating layer is formed at a temperature of 700 ° C. or more and having a coating layer having a thickness of 40 to 100 nm . In the manufacturing method of the pearl luster pigment of the silver coloring of Claim 1 ,
The flaky substrate is selected from natural mica, synthetic mica, glass flakes, silica flakes, alumina flakes, and barium sulfate.

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