JP3319037B2 - Manufacturing method of electronic ceramic material powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electronic ceramic material powder, and more particularly to a method for producing a fine electronic ceramic material powder having little cohesion and excellent dispersibility.

[0002]

2. Description of the Related Art Conventionally, as a method for producing fine electronic ceramic material powder, for example, fine electronic ceramic material powder composed of a composite oxide having a perovskite structure represented by the general formula ABO ₃ , there is known a method of producing water of A-site metal. The solution of the oxide and the solution of the hydrolyzable organometallic compound of the B-site metal are reacted in a heated state at 80 to 95 ° C. to form a composite oxide, and the precipitate obtained by this liquid phase reaction is reduced to 100%.
A method of drying in air at about ° C., and a precipitate obtained by the liquid phase reaction is filtered off, washed with water to remove impurities, and then washed with a hydrophilic organic solvent such as ethanol, methanol, isopropanol, and acetone. There is known a method of removing water by filtration and drying the same in air at about 100 ° C.

[0003]

In the above method, the material powder can be made ultrafine by a liquid phase reaction. However, in the former method in which the produced composite oxide is dried as it is to remove water, the composite oxide is dried. A relatively large amount of water adsorbed on the particle surface of the material powder, causing agglomeration due to the liquid crosslinking force acting between the powder particles caused by the adsorbed water, losing the advantage of the wet method of obtaining ultrafine particles. There is. In the latter method, the amount of water adsorbed on the particle surface is smaller than that in the former method because the solvent is washed with an organic solvent. There is a problem that is easily generated. In addition, when agglomeration occurs in the material powder, when obtaining a sintered body of electronic ceramic, its sinterability and denseness are significantly impaired, and it has been difficult to obtain an electronic ceramic part having desired characteristics. Further, not only the complex oxide having a perovskite structure but also a carbonate or an oxide as a raw material, a precipitate formed by a liquid phase reaction is separated by filtration, washed with water, and then evaporated and dried. However, since there is a large amount of adsorbed water on the particle surface, the particles are easily aggregated, and when mixed with other raw materials, they are not uniformly dispersed, and only electronic ceramics having a non-uniform composition can be obtained.

Accordingly, an object of the present invention is to provide an electronic ceramic material powder having less cohesiveness and good dispersibility without impairing the advantage that an ultrafine material powder obtained by a liquid phase reaction can be obtained. Is the subject.

[0005]

According to the present invention, as a means for solving the above-mentioned problems, an electronic ceramic material powder produced by a liquid phase reaction is washed with water and separated by filtration to obtain a water-containing slurry. After kneading with a molecular compound and separating water, it is kneaded with an organic solvent in which the lipophilic polymer compound is soluble to remove the hydrophilic polymer compound.

[0006] Examples of the electronic ceramic material powder include carbonates, oxides, and complex oxides having a perovskite structure represented by the general formula ABO _3. It is preferable that the solution of the oxide and the solution of the hydrolyzable organometallic compound of the B-site metal are reacted to form a composite oxide, which is separated by filtration and washed with water to obtain a water-containing slurry.

As the lipophilic polymer compound, any compound can be used as long as it is a lipophilic polymer compound. A typical example is an alkyd-based resin, but is not limited thereto. However, epoxidized phenol resins can also be used. Specifically, the alkyd resin has an average functional group of 2 or less and is obtained from a divalent acid and a dihydric alcohol, that is, 2-2.
An alkyd resin obtained from a functional group raw material can be used. In addition, even if a trivalent raw material is used, an alkyd resin using a monovalent raw material in combination can also be used because it becomes a non-invertable resin. Epoxidized phenolic resins include hydroquinonyl-3-epoxypropal and P.I.
There is a soluble epoxidized phenolic resin obtained by condensing P-diphenylolpropyl-3-epoxypropane with an aldehyde.

[0008] Examples of the organic solvent include aromatic hydrocarbons, esters and ketones. Any organic solvent can be used as long as it is soluble in the lipophilic polymer compound.

[0009]

The electronic ceramic material powder obtained by the liquid phase reaction is separated by filtration, washed with water, and kneaded with a lipophilic polymer compound to form a polymer film on the surface of the electronic ceramic material powder. Since the lipophilic polymer compound has water-repellency, an action of separating water from the surface of the electronic ceramic material powder particles occurs, and the electronic ceramic material powder and the water are separated from the water-containing slurry. Next, when the electronic ceramic material powder slurry from which the water was separated was mixed with an organic solvent compatible with the lipophilic polymer compound, the lipophilic polymer compound attached to the surface of the composite oxide particles was dissolved, and When the slurry is filtered, it is separated from the lipophilic polymer compound from the surface of the material powder, and then the organic solvent is easily removed by drying.

Hereinafter, the present invention will be described specifically with reference to examples.

[0011]

EXAMPLE A barium hydroxide octahydrate and tetraisopropyl titanate were used as starting materials, and these were contained in a molar ratio of 1: 1. After heating and stirring at 80 to 95 ° C. for hydrolysis, a precipitate of barium titanate generated was separated by filtration, washed with water and filtered twice to obtain a water-containing slurry of barium titanate fine powder.

6 g of alkyd resin was added to 50 g of this water-containing slurry, kneaded with an ultra disperser for 60 minutes, the separated water was removed, and 14 g of alkyd resin was added and kneaded for 60 minutes. After removing the water separated from the kneaded material again, 200 ml of toluene was added and kneaded for 60 minutes, and then filtered to separate the barium titanate powder from the alkyd resin solution. 200 ml of toluene was added again to the filtered barium titanate powder, and kneaded.
After washing, the powder was filtered off again and dried at 100 ° C. for 5 hours to obtain a barium titanate powder.

For comparison, 100 g of methanol was added to 50 g of the water-containing slurry obtained in the above example, kneaded and dispersed with an ultra disperser for 60 minutes, and the barium titanate powder was filtered off. Further, 100 ml of acetone was added to the filtered barium titanate powder, kneaded and dispersed with an ultra disperser for 60 minutes, and then the barium titanate powder was separated by filtration, dried at 100 ° C. for 5 hours, and used as a comparative sample. Barium titanate powder was obtained.

[0014] The comparative sample with the barium titanate powder of Example and infrared absorption spectrum analysis, the powder in (the height of the peak of barium titanate 3400 cm ^-1) / (height of the peak of the OH groups of 560 cm ^-1) When the ratio of the OH groups present in the body was determined, the ratio was 0.012 in the example and 0.160 in the comparative sample. From this, it can be seen that the barium titanate powder obtained by the method of the present invention has a water adsorption amount reduced to about 1/10.

Further, distilled water was added to each of the sample of the example and the comparative sample, and the mixture was dispersed by ultrasonic waves, and then subjected to particle size distribution measurement using a centrifugal sedimentation particle size distribution analyzer.
In the example, the D ₅₀ was 0.24 μm, whereas in the comparative sample, D ₅₀ was 1.8 μm. This means that the barium titanate powder obtained by the method of the present invention is dispersed in a state close to primary particles,
It can be seen that the dispersibility of the present invention is remarkably improved as compared with the comparative sample.

[0016]

As is apparent from the above description, the present invention provides a method of kneading a water-containing slurry composed of a composite oxide produced by a liquid phase reaction with a lipophilic polymer compound, separating water, and then filtering off. Then, the lipophilic polymer compound is washed with an organic solvent compatible with the polymer, removed and dried, so that the water adsorbed on the surface of the electronic ceramic material powder is removed, and the lipophilic polymer compound is coagulated. The liquid cross-linking force which causes the above can be remarkably reduced, so that it is possible to easily produce an electronic ceramic material powder having a small cohesive property and an excellent dispersibility, and thus the characteristics of the electronic ceramic component can be improved.

In the method of the present invention, the material powder in the slurry obtained by removing water with the lipophilic polymer compound has low water adsorption and is easily dispersed in an organic solvent. Later, the drying step is omitted, the binder resin is directly added and mixed, and the sheet can be formed,
Therefore, aggregation during drying can be prevented, and a ceramic green sheet having a uniform composition of finer particles can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukio Sakabe 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-5-4817 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 35/622

Claims (2)

(57) [Claims] 1. A material powder produced by a liquid phase reaction is washed with water and separated by filtration to obtain a water-containing slurry. The water-containing slurry is kneaded with a lipophilic polymer compound, water is separated, and then the lipophilic polymer compound is removed. A method for producing an electronic ceramic material powder, comprising kneading with a soluble organic solvent to remove a lipophilic polymer compound. 2. The method according to claim 1, wherein the material powder has a perovskite structure represented by the general formula ABO ₃ and reacts a solution of a hydroxide of an A-site metal with a solution of a hydrolyzable organometallic compound of a B-site metal. 2. A composite oxide comprising the obtained composite oxide.
The method described in.