JP3010247B2 - Plate-like alumina pigment and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent coating properties,
The present invention also relates to a plate-like pigment powder having excellent high-temperature stability. In particular, the pigment of the present invention is useful as a pigment for paints and a pigment for ceramics.

[0002]

2. Description of the Related Art In general, when an inorganic pigment is produced, it is produced by mixing and using appropriate raw material powders, followed by sintering and pulverization by various methods. Therefore, the shape of the pigment particles becomes granular, and it is difficult to control the shape. Further, since the whole particles are colored, a large amount of expensive raw materials required for coloring are required. Since it contains more vitreous, it reacts and decomposes at high temperatures and is unstable. For example, Japanese Patent Publication No. 6-10101 discloses Al ₂
O ₃ , TiO ₂ , SiO ₂ , Pr ₆ O ₁₁ , V ₂ O ₅ , MnO
_2. There is disclosed an invention of a decorative member of colored ceramics in which a mixed powder of a Co ₃ O _{4 and} an inorganic pigment is sintered, and the pulverized pigment powder is added to the ceramic powder. This is because in order to obtain pigment powder by crushing the sintered product, the shape of the pigment powder is not constant, the size varies, the orientation is inferior, and the crushing cannot be easily performed to make finer. Have a problem.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the problems of the prior art and to provide inexpensively a pigment powder which is controlled to have a plate-like shape and is stable even at a high temperature.

[0004]

Means for Solving the Problems The present inventors have found that the above objects can be achieved by a novel plate-like alumina pigment, and have reached the present invention. That is, the present invention relates to a method of forming Mg, Zn, Mn, Ni, C
Alumina spinel of o, Ti, Fe, Cr, Cu, V
Tabular alumina pigment, characterized in that more become colored complex metal oxide is present, and Mg that develops color by reacting with the alumina in tabular alumina, Zn, Mn, Ni, Co, T
i, Fe, Cr, Cu, V
Coated with a colored complex metal oxide that, 1000-1
This is a method for producing a plate-like alumina pigment, which is calcined at 900K. The plate-like alumina pigment of the present invention has excellent applicability because it has a plate-like shape and is easily oriented,
Also, since it is calcined at a high temperature using alumina as a base material, it has excellent high-temperature stability.

[0005] The plate-like alumina used as the starting base material of the present invention is characterized in that the alumina particles produced by the Bayer method or the like have a granular shape, whereas the alumina particles have a plate-like shape. Specifically, the maximum length of the plate-like alumina is defined as the particle diameter, and the particle diameter is 0.1 to 20 μm, preferably 0.5 to 20 μm.
１５15 μm and an aspect ratio of 2-50 , preferably 1
What is 0-50 is preferable. As a method for producing plate-like alumina, for example, a method of adding a mineralizer such as aluminum fluoride in a calcination step is known as disclosed in Japanese Patent Publication No. 35-6977. Japanese Patent Publication No. 37-7750 is known as a hydrothermal synthesis method. The coloring elements include Mg, Zn, Mn, Ni, Co, Ti, and F.
e, Cr, Cu, V are preferred . Specifically, Co ₃ O ₄ , Co
O, Co ₂ O ₃ , MnO ₂ , MnO, V ₂ O ₅ , TiO ₂ , M
gO, ZnO, NiO, CuO, Cu ₂ O, Fe ₂ O ₃ ,
FeO and the like. On the surface of the plate-like alumina, there is a colored metal oxide composed of an alumina-based spinel of these metal elements reacted with the surface.

[0006] A composite oxide having the above-mentioned colored metal oxide having a spinel structure is particularly preferable because it is easy to produce and stable. Examples of the alumina-based spinel composition include (Mg, Co) O.Al ₂ O ₃ (blue), CoO.
(Fe, Al) ₂ O ₃ (brown), etc. , MgO · Al ₂ O ₃ ,
ZnO.Al ₂ O ₃ , MnO.Al ₂ O ₃ , NiO.Al _{2
O 3, CoO · Al 2 O} 3, Al, such as FeO · Al ₂ O ₃
Minate type is mentioned. In the present invention, a metal or a metal compound composed of the above-described metal element that reacts with alumina to form a color on plate-like alumina particles is formed by a CVD method, a PVD method,
It is coated by a precipitation method or the like and calcined at a high temperature to produce a plate-like pigment powder. The calcination temperature is 1000-1
900K is preferred, and 1200-1600K is particularly preferred. The calcination time is from 15 minutes to 6 hours, preferably from 1 to 3 hours, at normal pressure or under pressure. The atmosphere is not particularly limited. For example, the reaction is performed in the air or in a nitrogen atmosphere.

The metal or metal compound used in the reaction includes metals, alloys, metal sulfates, metal oxides, hydrates and metal halides (particularly metal chlorides) composed of the above metal elements. No. The precipitation method is a method in which a precipitate is gradually formed on the surface of the plate alumina in a solution in which the plate alumina is mixed by a chemical reaction such as hydrolysis. In this case, the amount ratio of the metal or metal compound to the plate-like alumina can be changed in a wide range, but generally, the weight ratio is 1%.
７０70: 1, preferably 5-60: 1. By calcining at a high temperature, the surface of the plate-like alumina particles reacts with the metal or metal compound to form a colored metal composite oxide. The plate-like alumina pigment of the present invention can be used in various fields where inorganic pigments have conventionally been used. Since they are minute and plate-like, the pigment particles are easily aligned with each other, and therefore are particularly preferable as pigments to be added to thin-shaped articles and coatings. For example, they are suitable for paints, inks, and polymer materials. Also, since it is excellent in high-temperature stability, it also exhibits excellent performance as a ceramic pigment.

When used as a pigment for paints and inks, the resin vehicle is not particularly limited, and those for general paints can be used. For example, those having one or two or more reactive cross-linking functional groups in the molecule can be used. For example, a base resin selected from an acrylic resin, an alkyd resin, and a polyester resin and a melamine resin, a polyisocyanate compound, and a blocked polyisocyanate Combinations with a curing agent selected from compounds are mentioned.
The plate-like alumina pigment according to the present invention is basically hydrophilic and adapts well to an aqueous paint as it is. However, the use of an appropriate dispersant makes the paint more excellent. Further, if a hydrophobic treatment is performed with a coupling agent such as a silane coupling agent or a titanate-based coupling agent, it can be blended into a solvent-type paint. The plate-like alumina pigment is 1 to 100 parts by weight of the resin solid content of the coating material.
Although 120 parts by weight is blended, 40 to 120 parts by weight is a suitable range. The coating composition can be further mixed with various conventionally known additives, if necessary, to obtain a coating. For example, when used as a chipping-resistant paint, it contains various pigments, viscosity modifiers, anti-sagging agents, solvents and the like.

When the present invention is added to a polymer composition,
The polymer compound is not particularly limited, and is a natural or synthetic plastic or rubber. For example, polyethylene, polypropylene, polyvinyl chloride, acrylic resin, methacrylic resin, polystyrene, phenolic resin, polyamide resin,
Composite materials such as fluororesin, polyacetal resin, ABS resin, polyimide, FRP, polycarbonate, urea resin, epoxy resin, diallyl phthalate resin, polyphenylene oxide, polyphenylene sulfide, silicone resin, polyurethane, unsaturated polyester, alkyd resin, ethylene-vinegar Examples of such copolymers include block copolymers, graft copolymers, cellulose derivatives, natural rubber, butadiene rubber, isoprene rubber, rubbers such as SBR, EPR, EPT, and silicone rubber, such as bi-copolymers. Among them, epoxy resins, acrylic resins, various vinyl resins, urethane resins, amino alkyd resins, polyester resins, and the like are preferable from the viewpoint of transparency as described later. As described above, the plate-like alumina pigment according to the present invention is basically hydrophilic, and is compatible with a hydrophilic resin as it is, but can be more sufficiently dispersed by using an appropriate dispersant. It is also effective to treat with a hydrophobic resin by treating with a coupling agent such as a silane coupling agent or a titanate coupling agent.

The polymer composition to which the pigment of the present invention is added is used for various applications and is not particularly limited. Examples thereof include various molded articles, films or sheets, laminates, optical parts, tubular bodies, rods, hollow articles, and the like. In addition to belts and tires, they are used for gears, electrical equipment cabinets, bearings, rods, fans, turbines, building components, automobile components, pipes, bottles, tools, wheels, furniture, engineering plastics such as honeycomb structures, and the like. The above polymer composition is molded for the above uses by various molding methods. As the molding method, those used as processing methods for each polymer are applied. Further, the above-mentioned polymer composition may contain one or more other various additives, if desired. For example, as inorganic substances, asbestos powder, asbestos fiber, mica, talc, sulfuric acid balium, wollastonite,
Graphite, gypsum, diatomaceous earth, calcite, slate powder, rock wool, clay, kaolin, lineage, zinc white, lithopone,
Titanium white, glass fiber, steatite, inorganic pigment, carbon and the like.

Examples of the organic substance include wood flour, paper, hemp, woven cloth, shredded cloth, synthetic fiber, natural resin, organic pigment and the like. These various additives include fillers, plasticizers, lubricants, coloring agents, curing agents, modifiers, heat resistance, impact resistance, chemical resistance, abrasion resistance,
It is added for the purpose of improving conductivity. Conversely, known additives suitable for these purposes can be added to the polymer composition of the present invention. The weight ratio of the plate-like alumina pigment to the polymer compound in the polymer composition is from 1:99 to 99: 1. As pigments for ceramics, any of pigment bases, underglaze pigments, and onglaze pigments can be used.

[0012]

The present invention will be specifically described below with reference to examples. Example 1 100 parts of gibbsite and 100 parts of water were mixed to form 773
K, hydrothermal synthesis at 100 atm was performed to obtain a plate-like alumina powder. 75 g of the obtained plate-like alumina powder in 300 ml of water
/ L, cobalt sulfate 0.1 mol / l, urea 1 mol /
1 was added, precipitation treatment was carried out at 363 K, filtration and washing, followed by drying to obtain a plate-like alumina powder coated with cobalt oxide hydrate. This was calcined at 1473 K for 1 hour to obtain a blue plate-like pigment powder. It can be seen that the compound layer is formed only on the surface as shown in the X-ray diffraction pattern of FIG. The electron micrograph is shown in FIG. Examples 2 to 4 Instead of using cobalt sulfate, nickel sulfate, manganese sulfate or iron sulfate was used in the same manner as in Example 1 to obtain green, brown or ocher plate-like alumina pigment powders, respectively. Was completed. It can be seen that these plate-like alumina pigments have a compound layer formed only on the surface as shown in the X-ray diffraction patterns of FIGS. The electrophotographs are shown in FIGS.

Example 5 An experiment similar to that of Example 1 was carried out using a combination of a coloring element and a calcination temperature. The results shown in Table 1 were obtained. In addition, in order to show that the plate-like alumina pigment of the present invention has a property of being easily oriented, plate-like alumina adhered to a glass sample table by a precipitation method (slurry method) was compared with a powder method for comparison. 9 (slurry method) and 10 (powder method) show the X-ray diffraction patterns of the granular alumina deposited in step (1). As a result, FIG. 10 obtained by the powder method almost matches the X-ray diffraction pattern of FIG.
The (1,1,3) plane of the alumina is (1,0,4),
(1,1,6), which indicates that the plate-like alumina pigment of the present invention has a property of being easily oriented.

[0014]

[Table 1]

[0015]

As described above, a plate-like pigment powder can be produced by using plate-like alumina particles, coating with a metal element which reacts with alumina to form a color, and calcining at a high temperature. Control of the particle size, aspect ratio, and the like can also be performed by controlling the plate-like alumina particles. When the plate-like pigment particles thus produced are mixed with a paint or the like and used, the particles are easily oriented, and thus exhibit excellent coating properties.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction pattern of the pigment of the present invention.

FIG. 2 is an X-ray diffraction pattern of another pigment of the present invention.

FIG. 3 is an X-ray diffraction pattern of another pigment of the present invention.

FIG. 4 is an X-ray diffraction pattern of another pigment of the present invention.

FIG. 5 is an electron micrograph of a plate-like alumina pigment of a Co-based coating.

FIG. 6 is an electron micrograph of a plate-like alumina pigment coated with a Ni-based coating.

FIG. 7 is an electron micrograph of a plate-like alumina pigment coated with a Mn-based coating.

FIG. 8 is an electron micrograph of a plate-like alumina pigment coated with an Fe-based coating.

FIG. 9 is an X-ray diffraction pattern of a plate-like pigment by a slurry method.

FIG. 10 is an X-ray diffraction pattern of a granular pigment by a powder method.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Saburo Sano 3-2-3, 15-24 Kita Chikusa, Chikusa-ku, Nagoya-shi, Aichi Prefecture (72) Inventor Masaki Maeda 49- 1 (72) Inventor Yoji Matsuo 4016, Mikkaichi, Kurobe City, Toyama Prefecture Examiner Chiyako Inoue (56) References JP-A-5-17132 (JP, A) JP-A-4-39362 (JP, A) JP-A-4-4 28771 (JP, A) JP-A-63-254169 (JP, A) JP-A-5-279594 (JP, A) JP-A-6-135714 (JP, A) WO 93/11194 (WO, A1) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) C09C 1/40 C09C 3/06 C01F 7/02

Claims (4)

(57) [Claims] 1. The surface of a plate-like alumina is coated with Mg, Zn, Mn, Ni, Co, Ti, Fe, Cr,
A plate-like alumina pigment comprising a colored composite metal oxide comprising an alumina spinel of Cu and V. 2. The particle size of said plate-like alumina is 0.1 to 2
2. The plate-like alumina pigment according to claim 1, wherein the alumina pigment has an aspect ratio of 0 to 50 [mu] m. 3. Mg, Zn, Mn, Ni, Co, Ti, Fe, C which develops color by reacting with alumina on plate-like alumina
A method for producing a plate-like alumina pigment, characterized in that a colored composite metal oxide comprising alumina spinels of r, Cu, and V is coated and calcined at 1000 to 1900K. 4. The method according to claim 1, wherein the coating is formed by CVD, PVD.
The method for producing a plate-like alumina pigment according to claim 3, wherein the coating is performed by a method selected from a precipitation method and a precipitation method.