JP2002256174A - Color luster pigment and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color luster pigment which has both a sense of transparency and a sense of brightness and can impart a delicate color variation and, simultaneously, has excellent weatherability and moisture resistance, and its manufacturing method. SOLUTION: The color luster pigment comprises a base material covered with a metal oxide, and the above base material has scaly particles of silica having an average particle diameter of <=50 μm and an aspect ratio of 10-300, and is preferably constituted of scaly silica particles composed of a layer polysilicic acid such as silica X or silica Y.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a deep transparency and brightness, which is difficult with existing pigments, can impart a subtle change in color tone, and has excellent weather resistance and The present invention relates to a novel colored luster pigment having a moisture resistance, for example, a pearly luster, a method for producing the same, and an article containing such a colored luster pigment.

[0002]

2. Description of the Related Art Colored luster pigments have various colors and colors such as pearlescent luster and metallic (metallic) luster, and are highly designed. Add to a wide range of materials such as cosmetics, printing inks, plastic materials, and coloring materials,
It is used after being blended.

[0003] For example, Japanese Patent Application Laid-Open No. 7-309718,
JP-A-11-279433 and JP-T-2000-5
As disclosed in Japanese Patent No. 05833, etc., a colored glossy pigment is obtained by coating a base material such as mica (mica) chips with various metal oxides, and has a color tone having a glossy transparency and brightness. Arises from light interference due to optical properties such as the type of metal oxide and the substrate contained. For example, a pigment having a titanium oxide film gives a pearl or silvery white coloring, depending on its thickness, and a pigment having an iron oxide film gives an inherent red to yellow coloring depending on its thickness. .

In this case, the role of a substrate such as mica, on which the metal oxide is coated, is important and relates to the color tone given by the pigment together with the metal oxide, particularly when the pigment is mixed with a transparent paint. Depending on the base material, there is a difference between those having only the surface and those having a deep portion even with the same transparency, and a coating film having a greatly different design due to luminance and light reflection. Originally, the problem of color tone comes from personal preference, and a slight difference is a big problem.

[0005] In addition, when the pigment is used as a coating material for a car body such as an automobile, a ship, or the like, the base material of the colored glossy pigment may change in appearance over a long period even under various weather conditions and use conditions. Is not allowed,
Extremely high stability is required.

[0006] Despite having such an important role, as a base material for a colored glossy pigment, a flake of mainly natural materials such as mica (mica), talc, kaolin, glass, silica, ceramics and the like has hitherto been used. Only the shape is used. However, as the taste for color tone has increased in recent years, the design has become larger, and various color tones and colors according to personal tastes have been required.In addition, the use conditions have become severer and the use period has been prolonged. With the demand for highly stable pigments, materials that are superior to conventional materials have been demanded.

[0007]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a deep transparent feeling and a luminous feeling, which are difficult with an existing pigment, and to provide a subtle color tone change. As a result, the design is larger, it can have various high-quality colors, colors, etc., and it has excellent weather resistance and moisture resistance even under severe conditions of use and period of use. It is an object of the present invention to provide a novel colored glossy pigment, a method for producing the same, and a composition containing such a colored glossy pigment, such as a paint, a plastic, or a cosmetic.

[0008]

Means for Solving the Problems The present inventors have conducted various studies on a material serving as a base material for coating the metal oxide in the above-mentioned colored glossy pigment, and found that the base material has the following average particle diameter and aspect ratio. Is a silica flake-like particles having a specific range, among them, consisting of a layered polysilicic acid such as silica X or silica Y, the primary particles of very thin nano-scale flake-like silica, especially such flake-like It has been found that when a base material composed of a secondary silica particle having a laminated structure in which a plurality of primary particles are overlapped in parallel is used, the characteristics of the colored glossy pigment are significantly improved.

Thus, according to the present invention, as a pigment,
A pigment with high designability with deep transparency and brightness, rich color tone, color, etc., and at the same time, excellent stability in weather resistance and moisture resistance even under severe conditions of use and period of use Is obtained.

In the present invention, it is not necessarily clear why an excellent colored gloss pigment can be obtained when a substrate comprising the above-mentioned specific silica flaky particles is used,
It is estimated as follows. Silica itself is originally white,
In the case where the silica is a scale-like particle having a predetermined range as an average particle diameter and a predetermined range as an aspect ratio, which is a transparent material having a high chemical stability. Since the metal oxide serving as the coloring substance is intricately supported and coated in the gaps and the particle surfaces where a plurality of extremely thin flaky particles are stacked, it has unique characteristics that cannot be obtained with conventional pigments of this type. It is thought to be a pigment that gives a coloring.
In particular, in the present invention, when the silica flaky particles are composed of a layered polysilicic acid such as silica X or silica Y, excellent characteristics are obtained.

Further, the excellent weather resistance, moisture resistance and stability of the pigment using the base material of the present invention are based on the fact that the above-mentioned flaky silica has a silanol group (-SiOH) per specific surface area.
It is thought to be due to the fact that the concentration has a value several times to several tens times larger than that of ordinary silica gel. When a pigment is produced using silica particles having such a large silanol concentration, the particles are extremely strongly bound to each other during the mixing and stirring process with the metal oxide, exhibiting a self-forming property, and drying and firing. In this case, condensation of silanol groups and the like occur, and particle binding occurs, so that a pigment having the above-mentioned excellent properties is considered to be obtained. The description of these mechanisms is not necessarily confirmed and is merely an inference, and does not restrict the interpretation of the present invention.

Thus, the present invention sufficiently achieves the above-mentioned object, and has the following constitution. (1) A colored glossy pigment including a base material coated with a metal oxide, wherein the base material is a silica flake particle having a particle diameter of 50 μm or less and an aspect ratio of 10 to 300. Characterized colored luster pigment. (2) The colored glossy pigment according to the above (1), wherein the flaky silica particles are composed of layered polysilicic acid. (3) The colored glossy pigment according to the above (2), wherein the layered polysilicic acid comprises silica X or silica Y. (4) A scale structure in which silica scale-like particles are formed by stacking a plurality of scale-like primary particles in parallel with each other between their surfaces and having a thickness of 0.01 to 0.5 μm
m, the colored glossy pigment according to the above (1), (2) or (3), which is a secondary particle of flaky silica having a surface diameter of 2 to 5 μm. (5) wherein the metal oxide is an oxide of one or more metals selected from titanium, iron, cobalt, aluminum, zirconium, nickel, chromium, and tin.
The colored glossy pigment according to any one of (4). (6) A method for producing a colored glossy pigment including a substrate coated with a metal oxide, the substrate comprising silica flaky particles having an average particle diameter of 50 μm or less and an aspect ratio of 10 to 300. A water-soluble metal salt in the presence of an alkali metal salt or an alkaline earth metal salt, and controlling the pH to form a hydroxide or hydrated oxide of the metal. A method for producing a colored glossy pigment, which is deposited on a substrate and then calcined at 500 to 1100 ° C. (7) Among the materials selected from paints, coloring materials, light diffusion sheets, plastic materials and cosmetics, the above (1) to
An article containing any one of the colored glossy pigments according to (5).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The base material of the colored glossy pigment of the present invention is a material for coating a metal oxide, and has an average particle size of 50 μm or less and an aspect ratio of 10 to 30.
It consists of scale-like particles of silica which is 0. Here, the average particle diameter is measured by a laser-scattering particle size analyzer (for example,
HORIBA LA-920, manufactured by Horiba, Ltd.). Such an average particle diameter is 50 μm
When it exceeds, the transparency of the obtained pigment is lowered, and it is difficult to obtain a deep gloss. On the other hand, if the average particle size is too small, it is difficult to obtain the gloss itself, so 0.01 μm
m or more. Above all, the average particle size is
It depends on the purpose of the pigment.
0 to 30 μm is preferable, and in the case of a paint or the like,
0.05 to 10 μm is preferred.

The aspect ratio of the substrate represents the ratio of the major axis to the thickness of the silica flaky particles, and greatly affects the performance of the substrate. One feature of the present invention is that the aspect ratio is sufficiently larger than that of a conventional substrate. In the present invention, the aspect ratio is 10 to 300.
It is necessary to be. When the aspect ratio is less than 10, the thickness increases, the transparency is lost, and it is difficult to obtain a good color tone. When the aspect ratio exceeds 300, the thickness becomes small and the strength is reduced, so that the pigment is easily broken, so that it is difficult to obtain a pigment having uniform characteristics. Above all, the aspect ratio is more preferably 20 to 200, and particularly preferably 20 to 100.

In the present invention, the silica flaky particles forming the substrate are preferably silica made of layered polysilicic acid. The layered polysilicic acid is a polysilicic acid having a silicate structure whose basic structural unit is composed of SiO ₄ tetrahedron, and means an H-type and / or a salt type such as an alkali metal. Examples of these layered polysilicic acids include silica X,
Examples include silica Y, Kenyaite, macadite, macatite, islayite, kanemite, and octosilicate. In particular, in the present invention, silica X,
Alternatively, silica Y is preferred.

The characteristic of the flaky silica particles used in the present invention is that the silanol group (-SiOH) per specific surface area is 30 to 100 μmol / m ² , particularly 50 to 70 μmol / m ² . An extremely large silica material has a value several times to several tens times larger than that of silica gel or the like. Because of the high content of such silanol groups, it is believed that particularly excellent properties are exhibited when used as a substrate for a colored glossy pigment in the present invention. Here, the content of the silanol group is a numerical value determined by the following equation and measured by a thermogravimetric analysis method. (W × 1111.1) / SA In the above formula, W is from heating at 120 ° C. to 120
The difference in weight (%) at equilibrium up to heating at 0 ° C., and SA is the specific surface area by the BET method.

The flaky silica particles used in the present invention include:
Although it may be primary particles of flaky silica, it is substantially a secondary particle having a laminated structure in which a plurality of primary particles of flaky silica are oriented parallel to each other and overlap each other. Is preferred. The secondary particles of the flaky silica preferably have a thickness of 0.01 to 0.5 μm, particularly preferably 0.05 to 0.5 μm, and a surface diameter of preferably 0.1 to 0.5 μm.
It is preferably from 5 to 10 μm, particularly preferably from 1 to 5 μm. If the thickness and the surface diameter do not have the above ranges, the desired characteristics cannot be obtained, and physical characteristics such as strength cannot be obtained.

The secondary particles of the flaky silica form pores in the gaps between the primary particles of the lamellar ultra-thin flake silica.
01-1.0 ml / g, especially 0.10-0.15 ml
/ G is preferred. The specific surface area is preferably 2
0~200m ² / g, particularly preferably a 50-80 m ² / g.

The flaky silica particles having a specific average particle size and aspect ratio used in the present invention are produced by various methods. Among them, flaky silica composed of layered polysilicic acid such as silica X or silica Y is preferably produced by the following method. That is, by subjecting a silica hydrogel, active silicic acid or hydrous silicic acid to hydrothermal treatment at 150 to 220 ° C. in the presence of an alkali metal salt, primary particles and secondary particles are three-dimensionally flaky silica. Can be produced. The tertiary aggregated particles are pulverized and dispersed using a wet pulverizer or the like, whereby the above-mentioned secondary particles of the flaky silica are produced. These flaky silicas are sold by Asahi Glass Co., Ltd. under the trade name “Sun Lovely (registered trademark)”.

The colored glossy pigment according to the present invention, comprising a substrate comprising the above-mentioned silica flaky particles, is preferably produced as follows. A slurry-like aqueous dispersion containing a substrate of silica flake particles is prepared. The concentration of the flaky silica particles in the aqueous dispersion is preferably 1 to 30% by mass,
Particularly, 5 to 15% by mass is suitable. Such an aqueous suspension is preferably heated to 50-100 ° C., while one or more of the water-soluble salts of the metal, which are ultimately coated as oxides on the substrate, are added under stirring. You. In this case, by adding an acid or a base in the presence of a water-soluble alkali metal salt or alkaline earth metal salt, such as sodium hydroxide, potassium hydroxide, and calcium hydroxide,
The pH of the aqueous suspension is preferably controlled between 1 and 7, particularly preferably between 2 and 5. Thereby, the metal salt is
Hydrolysis of the metal hydroxide or hydrated oxide is precipitated on the surface of the silica flaky particles simultaneously with the addition to the aqueous suspension or over time.

The substrate having on its surface precipitates of metal hydroxides or hydrated oxides is then preferably washed,
And after drying at 60-180 degreeC preferably, it is baked at 500 degreeC or more, preferably 800-1100 degreeC. Such calcination converts the metal hydrate or hydroxide to an oxide. The firing temperature and time vary depending on the type and thickness of the metal oxide coated on the substrate, but are preferably performed for 20 minutes to 2 hours.

As the metal salt added to the above aqueous suspension and finally converted into the metal oxide, any water-soluble salt which can be hydrolyzed by an acid or a base can be selected. Preferred metal salts include titanium, iron, cobalt, aluminum, zirconium, nickel, chromium,
Examples include tin hydrochloride, sulfate, or oxalate. Two or more of these metal salts can be used in combination. When two or more kinds are used, these can be used at the same time to obtain a pigment in which a plurality of metal oxides are coated on a substrate as a mixture. A pigment coated on a substrate in a form in which the metal oxide is laminated can also be obtained.

The amount of the metal oxide coated on the surface of the substrate in the colored glossy pigment produced in this manner depends on the amount of the substrate 1
It is preferably 50 to 300 parts by mass with respect to 00 parts by mass. Coatings smaller than the above range are not preferred because gloss will be reduced and excessive coatings will result in loss of transparency. Among them, the coating amount is preferably from 100 to 200 parts by mass.

Further, in the present invention, when obtaining a pigment in which a metal oxide is coated on the base material of the silica flaky particles, a water-soluble metal salt is added to the aqueous suspension of the silica flaky particles. In the process, a suitable doping agent is added to adjust the color tone, gloss, transparency, and the like of the obtained pigment. As the doping agent in this case, for example,
Borates such as alkali metal borates and silicates such as water glass are selected. These doping agents are preferably contained in the total pigment in an amount of 0.05 to 10% by mass.

Further, in the present invention, the color tone, gloss, transparency, durability, corrosion resistance and the like of the pigment obtained by subjecting the metal oxide-coated substrate obtained as described above to a surface treatment are obtained. Can be improved. Such a surface treatment preferably includes a silane coupling agent. As the silane coupling agent, any suitable silane coupling agent can be used, and preferred examples thereof include a non-aminosilane-based coupling agent and an aminopropyltriethoxysilane-based coupling agent. Specifically, [gamma] -glycidoxypropyltrimethoxysilane, [gamma] -aminopropyltriethoxysilane, [gamma] -trimethacryloxypropyltrimethoxysilane, [gamma] -isocyanatopropyltriethoxysilane [beta]-(3,4-epoxycyclohexyl) -Ethyltrimethoxysilane and the like.

The treatment of the base material having the surface coated with the metal oxide with these silane coupling agents is carried out by a dry method or a wet method, preferably by a wet method. For example, the above-mentioned base material is added to an aqueous liquid in which a silane coupling agent has been dissolved or dispersed, and the mixture is preferably sufficiently stirred and mixed for several hours or more. The coating amount of the silane coupling agent with respect to the substrate having the metal oxide is preferably 100 parts by mass of the former, and the latter is preferably 0.1 to 10 parts by mass,
0.25-5 parts by weight are preferred. The pigment obtained after the treatment is filtered and dried.

The colored glossy pigment of the present invention thus obtained has excellent properties as described above and can be used in a wide range of fields. For example, it is added to various materials such as paints, coloring materials, light diffusion sheets, plastic materials, and cosmetics. Above all, when the colored glossy pigment of the present invention is added to a paint for a vehicle such as an automobile, the pigment has a deep transparency and brightness that were difficult with an existing pigment, and for example, a pearly luster. It is possible to provide a paint which can impart a certain subtle color change and further has excellent weather resistance and moisture resistance.

[0028]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples of the colored glossy pigment of the present invention. However, it is needless to say that the present invention is not limited to these.

Example 1 "Sun Lovely LF" which is a secondary particle of flaky silica
A slurry having a solid content of 5% by mass of "S" (trade name of Asahi Glass Co., Ltd.) was prepared. The silica particles in the slurry are silica X particles, and are secondary particles of silica having a laminated structure in which a plurality of scale-like primary particles are formed to overlap and be oriented in parallel, and have a thickness of 0.1 μm. Surface diameter is 4
μm leaf-shaped particles are the largest, and the average particle size is 1.2
μm, and the aspect ratio was 40. The pore volume was 0.13 ml / g and the specific surface area was 55 m ² / g. The content of the silanol group per specific surface area was 65 μmol / m ² .

After heating the above slurry to 75 ° C.,
The pH was adjusted to 4 by addition of wt% hydrochloric acid. On the other hand, a 2 liter aqueous solution of FeCl ₃ (Fe content: 2
1% by mass) was added over about 8 hours with stirring.
During this addition, the pH of the slurry was kept at 4 by adding a 30% by weight aqueous NaOH solution. FeC
added after the end of the l _3, further after stirring for 15 minutes, 5 wt%
The pH of the slurry to which an aqueous solution of NaOH was added was adjusted to 6.7. As a result, a precipitate composed of hydroxide or hydrated oxide of iron was observed on the surface of the silica particles.

Thereafter, the slurry liquid is separated by filtration.
After washing with water, drying at 80 ° C. for 1 hour, 850
C. for 1 hour. The obtained pigment had a reddish color tone and had a deep glossiness. When the pigment was analyzed, it was found that the surface of the silica particles was coated with iron oxide having an average thickness of 100 μm.

Example 2 The same operation as in Example 1 was carried out except for the following points.
That is, instead of FeCl ₃ , 0.8 liters of TiC
l ₄ aqueous solution (Ti content: 350 g / l) was used to such a TiCl ₄ aqueous solution over a period of about 8 hours, it was added to the slurry. Also, the pH during addition of the TiCl ₄ aqueous solution
Is maintained at 2.2 instead of 4.4 in Example 1, and the pH adjustment after the addition of the TiCl ₄ aqueous solution is as follows:
Adjusted to 6.5 instead of 6.7.

The obtained pigment had a milky white color and had a deep pearl luster. When the pigment was analyzed, the average thickness of the pigment was 1
It was coated with 00 μm titanium oxide.

[0034]

According to the present invention, it is possible to have a deep transparency and brightness and a subtle change in color tone, which were difficult with existing pigments. The present invention provides a novel colored glossy pigment which has various colors, colors, etc. having a high degree of stability, and has excellent weather resistance and moisture resistance even under severe conditions due to prolonged use conditions and use periods, and a method for producing the same. You. According to the present invention, articles such as paints, light diffusion sheets, plastics, and cosmetics containing the colored glossy pigment are provided.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C09D 201/00 C09D 201/00 F term (reference) 4C083 AB171 BB23 BB25 BB26 CC01 EE03 EE50 FF01 4J037 AA17 AA18 CA09 DD05 EE03 EE26 EE43 EE46 EE47 EE50 FF09 FF22 FF25 4J038 EA011 HA216 HA436 HA446 KA08 KA15 KA20 NA01 NA03 NA04

Claims (7)

[Claims] 1. A colored glossy pigment comprising a base material coated with a metal oxide, wherein the base material is silica flaky particles having an average particle diameter of 50 μm or less and an aspect ratio of 10 to 300. A colored glossy pigment characterized by being present. 2. The colored glossy pigment according to claim 1, wherein the flaky silica particles are composed of layered polysilicic acid. 3. The colored glossy pigment according to claim 2, wherein the layered polysilicic acid comprises silica X or silica Y. 4. The method according to claim 1, wherein the silica flaky particles comprise a plurality of flaky particles.
Having a layered structure in which the secondary particles are formed so as to overlap and overlap with each other in a direction parallel to each other, and have a thickness of 0.01 to 0.1 mm.
The colored glossy pigment according to claim 1, which is a secondary particle of flaky silica having a surface diameter of 5 μm and a surface diameter of 0.5 to 10 μm. 5. The method according to claim 1, wherein the metal oxide is an oxide of at least one metal selected from titanium, iron, cobalt, aluminum, zirconium, nickel, chromium and tin.
5. The colored gloss pigment according to any one of the above items 4. 6. A method for producing a colored glossy pigment containing a substrate coated with a metal oxide, comprising silica flake particles having an average particle size of 50 μm or less and an aspect ratio of 10 to 300. To the aqueous suspension containing the substrate, a water-soluble salt of a metal corresponding to the metal oxide is added in the presence of an alkali metal salt or an alkaline earth metal salt, and the pH is controlled by controlling the pH of the metal. Deposited on the substrate as hydroxide or hydrated oxide, then 500-1100 ° C
A method for producing a colored gloss pigment which is fired at 7. A material selected from the group consisting of paints, coloring materials, light diffusion sheets, plastics and cosmetics.
An article comprising the colored glossy pigment according to any one of the above.