JP3579088B2 - Ultrafine brown pigment and method for producing the same - Google Patents

Description

【００２５】
【発明の効果】
本発明の超微粒子褐色系顔料は、塗料、インキ、プラスチックスなど種々の用途の着色顔料として好適なものであり、とりわけ彩色意匠性に富んだ優れたフリップ・フロップ効果が望まれるメタリック塗料系に極めて好適なもので、色分かれや色ムラなども惹起することなく、かつ耐候性や耐熱性にも優れたので、高級塗装仕上げに有用なものである。また本発明の製造方法は、チタン源としてとりわけルチル結晶の微小チタニアゾルを使用したり、さらにケイ素化合物やアルミニウム化合物を添加して焼成処理したりすることによって、一層工業的有利に製造することができる。[0001]
[Industrial applications]
The present invention relates to an ultrafine brown pigment exhibiting excellent design properties, durability and dispersibility and a method for producing the same, and the ultrafine brown pigment of the present invention is used for coloring paints, inks, plastics, and the like. It is used as a pigment and is particularly useful for high-grade industrial paints such as automotive paints.
[0002]
[Prior art]
In recent years, ultra-fine titanium dioxide having an average particle size of 0.01 to 0.1 μm is blended with a resin medium together with a metal flake pigment such as aluminum flake or a metal luster pigment such as titanium mica to form a so-called excellent flip- High-grade metallic paint finishes that exhibit a flop effect and are excellent in design have attracted attention and have been put to practical use.
[0003]
[Problems to be solved by the invention]
By the way, recently, the demands for diversification and high-grade coloring design of automobiles and high-grade painted finishing products have been further intensified, and furthermore, a metallic coloring exhibiting a highly individualized and excellent coloring design flip-flop effect. There is a strong need for a paint composition for finish coating. For this reason, for example, although it has been tried to prepare a metallic coating composition by blending a white fine powder such as the above ultrafine titanium dioxide and various organic pigments, color separation and color unevenness are caused. There are still a number of problems that still need improvement, such as ease of use and insufficient weatherability and heat resistance.
[0004]
[Means for Solving the Problems]
The present inventors have always focused on the excellent light scattering ability of titanium oxide-based colored pigments, and by selectively controlling the light scattering ability, imparted a variety of flip-flop effects in a metallic paint finishing system to achieve coloring. Various studies were conducted to enrich the design and to solve the above-mentioned problems. As a result, the ultra-fine colored pigment of a specific coloring system composed mainly of titanium and sharing a specific component with this component has a superior flip-flop effect rich in coloring design with a metallic coating system. It can be provided as a novel ultrafine brown pigment which exhibits ultrafine titanium oxide, particularly titanium oxide fine rutile crystals, as a titanium source. It has been found that by treating the compound of formula (1) and post-baking, an ultrafine brown pigment having desired desired properties can be produced industrially and advantageously, and the present invention has been completed.
[0005]
That is, the present invention
1. Neutralize the aqueous solution of titanium tetrachloride to obtain a fine titania sol having a rutile-type crystal structure, and then, in the aqueous dispersion slurry of the fine titania, add a silicon compound as a baking treatment auxiliary to the TiO of the fine titania in terms of oxide. 1 to 10% by weight with respect to ₂ to cover the surface of the fine titania with the silicon compound. Then, the aqueous dispersion slurry of the fine titania coated with the silicon compound is mixed with antimony based on 100 parts by weight of the TiO _{2 of} the fine titania. The source is characterized by adding and mixing 10 to 40 parts by weight of Sb ₂ O _{3 and 3 to} 15 parts by weight of manganese source as MnO , and then calcining the treated product at a temperature of 800 to 1050 ° C. A method for producing an ultrafine brown pigment having an average particle size of 0.01 to 0.15 μm comprising titanium, antimony and manganese oxides ,
2. The ultrafine brown pigment produced by the method described in 1 is made into an aqueous dispersion slurry, and after adding a water-soluble salt of at least one element selected from the group consisting of aluminum, silicon, titanium, zirconium, tin and antimony, Or a method for producing ultrafine brown pigments, which comprises neutralizing by adding an alkali to precipitate on the surface of the brown pigment, separating, drying and pulverizing ; The ultrafine brown pigment, characterized in that the surface of the ultrafine brown pigment produced by the method according to the above 1 or 2, is coated with at least one organic compound selected from the group consisting of polyhydric alcohols, alkanolamines and organosilicons. This is a method for producing a series pigment.
[0006]
The ultrafine brown pigment of the present invention is composed of oxides of titanium, antimony, and manganese, and has an average single particle diameter of 0.01 to 0.15 μm, preferably 0.03 to 0.1 μm, as determined by electron microscopy. belongs to. If the average single particle diameter is smaller than the above range, a desired flip-flop effect is not obtained, and if it is larger than the above range, a solid coating film which does not exhibit the desired flip-flop effect tends to be obtained. Usually, it contains 10 to 40 parts by weight, preferably 15 to 35 parts by weight of an oxide of antimony as Sb ₂ O _{3 and 3 to} 15 parts by weight, preferably 4 to 12 parts by weight of an oxide of manganese as MnO 2, The balance consists essentially of oxides of titanium, and may also contain very small amounts of oxides of lithium, sodium, phosphorus, calcium, etc., if necessary. Such an ultrafine brown pigment exhibits a deep reddish brown to purple brown color, and is mixed with a resin medium together with a metal flake pigment such as aluminum flake or a metallic luster pigment such as titanium mica to give a unique color. A paint composition such as a metallic paint or a pearl paint having a flip-flop effect and excellent in design can be obtained.
[0007]
The ultrafine brown pigment of the present invention further has a surface thereof coated with a hydrated oxide or oxide of at least one element selected from the group consisting of aluminum, silicon, titanium, zirconium, tin and antimony, and a polyhydric alcohol, alkanolamine. And a coating of at least one organic compound selected from the group of organosilicons. The ultrafine brown pigment having such a coating is excellent in dispersibility and durability in a resin medium, and can exhibit a more favorable flip-flop effect in the coating composition. Coverage, compared brown pigments nucleus, aluminum 1 to 30 wt% as _Al 2 _{O 3,} silicon 1-20% by weight SiO _2, each other compounds oxides _(TiO 2, _ZrO 2, SnO ₂ , Sb ₂ O ₃ ) is suitably from 0.3 to 15% by weight. In the case of coating with an organic compound, it is appropriate that each solid content is 0.3 to 5% by weight based on the brown pigment of the core.
[0008]
In the production method of the present invention, a brown pigment can be obtained by mixing base components of a titanium source, an antimony source and a manganese source and calcining the mixture at a temperature of 700 to 1100 ° C. The present invention is particularly characterized in that ultrafine titanium oxide hydroxide is used as a titanium source. This is a fine titania sol having a rutile-type crystal structure, a fine hydrated titanium oxide sol showing a rutile-type crystal peak as measured by an X-ray diffraction method, and its average crystallite diameter is usually 50 to 120 ° C. belongs to. This is, for example, to ripen a colloidal amorphous hydrous titanium oxide obtained by neutralizing an aqueous solution of titanium tetrachloride with aqueous ammonia at pH 7 to 8, or to prepare an amorphous hydrous titanium oxide such as metatitanic acid or orthotitanic acid. It is obtained by heat-treating titanium oxide in an aqueous sodium hydroxide solution and then heat-treating it in a hydrochloric acid solution, or by heating and hydrolyzing an aqueous solution of titanium tetrachloride. In the present invention, such a fine titania sol having a rutile type crystal structure can be used as it is or after being pulverized as finely as possible after drying.
[0009]
Various sources can be used as the antimony source and the manganese source as the base component.Examples of the antimony source include antimony trioxide, antimony pentoxide, antimony pentachloride, antimony trichloride, and antimony soda. Manganese (II) chloride, manganese sulfate, manganese carbonate and the like can be used as a source.
[0010]
The mixing of the raw materials of the above-mentioned base components can be performed by various methods. For example, when powders are used as the raw materials, they may be simply mixed. When a compound solution of a base component of an antimony source or a manganese source is used, for example, a solution of these base components is added to and mixed with ultrafine titanium oxide-containing titanium oxide, and then dried, or ultrafine titanium oxide-containing hydrogenation is added. A compound solution of each component is added to an aqueous dispersion of titanium and neutralized with an acid or alkali to precipitate each component on the surface of the hydrous titanium oxide, or used as an aqueous dispersion of an antimony source and a manganese source. In this case, the aqueous dispersion may be added to a slurry of ultra-fine particles of hydrated titanium oxide, mixed and then filtered and washed.
[0011]
The mixing ratio of each component is such that antimony is 10 to 40 parts by weight, preferably 15 to 35 parts by weight, as Sb ₂ O ₃ , and manganese is _{3 to} 15 parts by weight as MnO ₂ with respect to 100 parts by weight of TiO _{2 of the} ultrafine titanium oxide hydroxide. Parts, preferably 4 to 12 parts by weight. In addition to these base components, various auxiliary components can be used. For example, a very small amount of a compound such as lithium, sodium, phosphorus, and calcium can be mixed.
[0012]
The raw material mixture obtained by mixing as described above is fired at a temperature of 700 to 1100 ° C, preferably 800 to 1050 ° C. The raw material mixture may be in the form of a slurry, a cake, or a dry powder. By firing, each component undergoes a solid phase reaction to form a color, and the brown pigment of the present invention is obtained. In the present invention, since ultra-fine hydrated titanium oxide is used as a titanium source, the fired product is easily pulverized by a dry pulverizer such as a micronizer, a jet mill, a roller mill, a bantam mill, and a sample mill, so that the average single unit can be easily obtained. An ultrafine brown pigment having a particle size of 0.01 to 0.1 μm can be obtained. It should be noted that the ultrafine titanium oxide hydrate used as the titanium source in the present invention is liable to undergo particle growth and sintering during firing, and in order to suppress such growth, a silicon compound and / or aluminum compound is subjected to a firing treatment. It is desirable to bake in the presence of an auxiliary. In this case, the auxiliary may be added to the ingredient material, mixed with the hydrous titanium oxide and the auxiliary in advance, or coated with the auxiliary on the surface of the hydrous titanium oxide in advance. Although possible, a coating method is more desirable. The amount of the auxiliary agent used varies depending on the mixing ratio of the component raw materials, the baking treatment conditions, and the like, and cannot be specified unconditionally. However, in terms of the oxide of the auxiliary agent, 1 to 10% by weight based on TiO _{2 in} the hydrous titanium oxide. , Preferably 3 to 8% by weight. Specific examples of the sintering treatment auxiliary used include, for example, inorganic silicon compounds such as water-soluble silicates such as colloidal silica and sodium silicate, and organic silicon compounds such as silicone oil and silane coupling agents. Examples of the aluminum compound include water-soluble aluminum salts such as aluminum sulfate, aluminum nitrate, aluminum chloride, and sodium aluminate.
[0013]
The calcination can be performed by various methods, for example, using a stationary furnace such as an electric furnace or a tunnel kiln, or an internal combustion type or an external combustion type rotary kiln.
[0014]
In the present invention, the ultrafine brown pigment obtained in this manner is further subjected to a hydrous oxidation of at least one element selected from the group consisting of aluminum, silicon, titanium, zirconium, tin and antimony on the particle surface. Or an organic compound selected from the group consisting of the above-mentioned and / or polyhydric alcohols, alkanolamines, and organosilicons. And durability can be further improved. The ultrafine brown pigment thus obtained can exhibit a more favorable flip-flop effect in a coating composition such as a metallic coating or a pearl coating. The coating amount is 1 to 30% by weight of aluminum as Al ₂ O ₃ , 1 to 20% by weight of silicon as SiO ₂ , and other compounds are oxides (TiO ₂ , ZrO ₂₎ with respect to the brown pigment of the core. , SnO ₂ , Sb ₂ O ₃ ) is suitably from 0.3 to 15% by weight. In the case of coating with the organic compound, 0.3 to 5% by weight based on the core brown pigment is appropriate as each solid content.
[0015]
The ultrafine brown pigment of the present invention is suitable not only for paints but also for various uses such as inks and plastics, but is a metallic paint composition capable of exhibiting an excellent flip-flop effect rich in color design. In particular, when it is subjected to The metallic coating composition can be prepared by various methods. For example, the ultrafine brown pigment and various metallic luster-like pigments such as flaky metal pigments and pearl pigments can be prepared in a ratio of from 0.1 to 0.1 to The mixing can be carried out by blending them in a weight ratio of 10 and dispersing them in various thermosetting or thermoplastic resins. These resins are usually blended at a ratio of 10 to 50% by weight of the coating composition.
[0016]
【Example】
Comparative Example 1
500 ml of an aqueous solution of titanium tetrachloride at a concentration of 200 g / l as TiO ₂ and an aqueous solution of sodium hydroxide at a concentration of 100 g / l as Na ₂ O were added in parallel to water so as to maintain the pH of the system at 5 to 9, Aged for hours. Resulting filter hydrous titanium dioxide precipitate ultrafine particles, washed, dispersed again in water and the water-containing titanium dioxide slurry at a concentration of 100 g / l as TiO _2. To this slurry was added Sb ₂ O ₃ powder 40 g, then 200 g / l of manganese sulfate aqueous solution was added (the MnSO ₄ 5H ₂ O 20% sulfuric acid solution to dissolve) 50 ml as MnO, ammonia water 20% aqueous solution The pH was adjusted to pH 7 by addition to produce a precipitate of the manganese component. After thus treated hydrous titanium dioxide slurry comprising a well stirred with a homomixer, and calcined 5 hours at 800 ° C. in an electric furnace, allowed to cool, to obtain ultrafine particles brown pigment by dry milling. This was a rutile crystal having an average single particle size (electron microscopy) of 0.03 μm.
[0017]
Comparative Example 2
The ultrafine brown pigment powder obtained in the same manner as in Comparative Example 1 was dispersed in water to form a slurry having a solid content of 100 g / l, wet-pulverized, and then heated to 70 ° C. A 1% by weight aqueous solution of stannous chloride as SnO ₂ was added to the solid content of the slurry, then a 2% by weight aqueous solution of zirconium sulfate was added as ZrO ₂ , and then an aqueous solution of sodium hydroxide was added to adjust the pH to 7. After the adjustment, a 7% by weight aqueous solution of sodium aluminate and sulfuric acid as Al ₂ O ₃ were added in parallel to maintain the pH of the system at 7 to 10, thereby precipitating the hydrated oxides of tin, zirconium and aluminum. I let it. Thereafter, filtration, washing, to obtain ultrafine particles brown pigment was dry-pulverized after drying. This was a rutile crystal having an average single particle size of 0.06 μm.
[0018]
Comparative Example 3
In Comparative Example 2, an ultrafine brown pigment was obtained by performing the same treatment as in Example 2 except that the firing temperature was 950 ° C. This was a rutile crystal having an average single particle diameter of 0.08 μm.
[0019]
Example 1
10 ml of an aqueous solution of sodium silicate having a concentration of 100 g / l as SiO ₂ was added to the ultrafine titanium dioxide slurry containing 100 g / l as a TiO ₂ obtained in the same manner as in Comparative Example 1; The pH was adjusted to 7 by adding sulfuric acid, followed by filtration and washing to obtain ultrafine hydrated titanium dioxide coated with 1% by weight of a silicon compound as SiO ₂ . Next, this was again made into an aqueous slurry, and the slurry was treated with Sb ₂ O ₃ and MnO in the same manner as in Comparative Example 1 and then calcined at 950 ° C. for 5 hours to obtain ultrafine particles of the present invention. A brown pigment was obtained. This was a rutile crystal having an average single particle size of 0.04 μm.
[0020]
Example 2
The ultrafine brown pigment obtained in the same manner as in Example 1 was treated with SnO ₂ and Al ₂ O ₃ in the same manner as in Comparative Example 2 to obtain the ultrafine brown pigment of the present invention. A pigment was obtained. This was a rutile crystal having an average single particle size of 0.04 μm.
[0021]
Example 3
The procedure of Example 2 was repeated, except that the firing temperature was changed to 1050 ° C., to obtain the ultrafine brown pigment of the present invention. This was a rutile crystal having an average single particle diameter of 0.08 μm.
[0022]
Comparative Example 4
An aqueous solution of titanium sulfate having a concentration of 200 g / l as TiO ₂ was hydrolyzed by heating at 110 ° C. to form a hydrated titanium dioxide precipitate, which was filtered and washed, and then subjected to the same method as in Comparative Example 1 to obtain Sb ₂ O. ₃ and MnO, and then calcined at 1200 ° C. for 5 hours to obtain a brown pigment having an average single particle size of the rutile crystal of 0.3 μm.
[0023]
Test Examples The performance of the ultrafine brown pigment of each of the above examples and the brown pigment of the comparative example was tested, and the results shown in Table 1 were obtained.
The performance evaluation in Table 1 was performed as follows.
1. A paint preparation sample, 7.5 g, was mixed into 56.1 g (53% nonvolatile content) of a mixed varnish of acrylic resin / butylated melamine resin = 8/2 (weight ratio), and a paint shaker (Red Devil Co., # 5110) ) To form a paint, aluminum paste was added (sample / Al = 1/1 by weight) and mixed well to obtain a metallic paint.
2. Enamel paint color measurement An enamel paint without aluminum paste is applied on a white plate so that the dry film thickness becomes 60 μm, baked at 105 ° C. for 30 minutes, and the L value, a value and b value are measured with a color difference meter. It was measured.
3. Metallic coating color change color measurement This coating composition was applied on a steel plate so that the dry film thickness became 18 μm, and after setting for 30 minutes, an acrylic clear was applied so that the dry film thickness became 12 μm, and after 30 settings, Bake at 130 ° C. for 30 minutes. The color of this coated plate was measured using a gonio colorimeter GCMS-3 type (manufactured by Murakami Shiken) at an incident angle of 45 °, a measurement angle of 40 ° (face color), and −20 ° (flop color). ΔL, Δa, and Δb were obtained by the above method.
ΔL = L (40 °)-L (-20 °)
Δa = a (40 °)-a (-20 °)
Δb = b (40 °) −b (−20 °)
4. Comprehensive Evaluation From the colorimetric results of the above 2 and 3, the color design was comprehensively evaluated.
：: Both coloring property and flip-flop effect are the most excellent.
：: Both coloring and flip-flop effect are excellent.
×: No flip-flop effect.
[0024]
[Table 1]

[0025]
【The invention's effect】
The ultrafine brown pigment of the present invention is suitable as a coloring pigment for various uses such as paints, inks and plastics, and is particularly suitable for a metallic paint system in which an excellent flip-flop effect rich in coloring design is desired. It is extremely suitable and does not cause color separation or unevenness of color, and is excellent in weather resistance and heat resistance, so that it is useful for high-grade paint finishing. In addition, the production method of the present invention can be produced more industrially advantageously by using a fine titania sol of rutile crystal as a titanium source, or by adding a silicon compound or an aluminum compound and performing a calcination treatment. .

Claims (3)

Neutralize the aqueous solution of titanium tetrachloride to obtain a fine titania sol having a rutile-type crystal structure, and then, in the aqueous dispersion slurry of the fine titania, add a silicon compound as a baking treatment auxiliary to the TiO of the fine titania in terms of oxide. 1 to 10% by weight with respect to ₂ to cover the surface of the fine titania with the silicon compound. Then, the aqueous dispersion slurry of the fine titania coated with the silicon compound is mixed with antimony based on 100 parts by weight of the TiO _{2 of} the fine titania. The source is characterized by adding and mixing 10 to 40 parts by weight of Sb ₂ O _{3 and 3 to} 15 parts by weight of manganese source as MnO , and then calcining the treated product at a temperature of 800 to 1050 ° C. A process for producing an ultrafine brown pigment comprising titanium, antimony and manganese oxides having an average particle size of 0.01 to 0.15 μm. The ultrafine brown pigment obtained by the method according to claim 1 is made into an aqueous dispersion slurry, and after adding a water-soluble salt of at least one element selected from the group consisting of aluminum, silicon, titanium, zirconium, tin and antimony, A method for producing ultrafine brown pigments, comprising neutralizing by adding an acid or alkali to precipitate on the surface of the brown pigment, separating, drying and pulverizing. 3. Ultrafine particles, wherein the surface of the ultrafine brown pigment produced by the method according to claim 1 or 2 is coated with at least one organic compound selected from the group consisting of polyhydric alcohols, alkanolamines and organosilicones. A method for producing a brown pigment.