JPH04200735A - Production of ceramic sphere - Google Patents

Abstract

PURPOSE:To obtain a dense sphere in low cost by forming an org. polymer film by the interfacial condensation reaction of a slip prepared by dispersing a ceramic raw material in a solution containing a water-insoluble monomer and an aqueous solution containing a water-soluble monomer. CONSTITUTION:At first, a necessary ceramics raw material such as alumina or silicon nitride is dispersed in a solution of the first water-insoluble org. compound to obtain a slip. Next, an aqueous solution of the second compound forming an org. high-molecular substance by the interfacial condensation reaction with the first org. substance is prepared. The slip is dropped in the aqueous solution of the second compound. The slip becomes spherical and an org. polymer film is instantaneously formed on the interface thereof. The combination of the first org. compound and the second compound at this time is selected from polybasic acid halide and polyamine, polybasic acid halide and glycol, polyisocyanate and polyamine, polyisocyanate and water, and polyisocyanate and glycol.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a ceramic ball for kneading and pulverizing ceramic raw materials using an organic polymer synthesis method using an interfacial polymerization reaction, and a ceramic ball for a ceramic true spherical material. The present invention relates to a method for manufacturing ceramic balls.

[Prior art] Conventionally, press molding, transfer granulation, and alginate have been used to manufacture ceramic balls for mixing and pulverizing ceramic raw materials and ceramic ball bases for ceramic spherical bodies. A droplet coagulation method (in-liquid curing coating method) and the like are known.

[Problems to be solved by the invention] Among the methods currently known for producing ceramic balls, the press molding method has problems such as difficulty in producing small balls with a diameter of 3 mm or less and high manufacturing costs. However, the transfer granulation method has problems such as internal defects during manufacturing and low density of the obtained sintered body, and the droplet coagulation method using alginate requires operations such as dispersion of ceramic raw materials to be performed in an aqueous solution. Oxide-based ceramics such as magnesium oxide (MgO), which easily hydrate and solidify when exposed to water, and silicon nitride (SizNa), which easily undergoes decomposition reactions, are processed in a system.
Another problem is that it is difficult to apply to non-oxide ceramics such as aluminum nitride (AIN).

[Means for Solving the Problems] In order to solve the above-mentioned problems, the method for manufacturing ceramic spheres of the present invention includes a slurry in which a ceramic sphere raw material is dispersed in a solution containing a water-insoluble monomer, and a water-soluble monomer. It is manufactured by forming an organic polymer film using an aqueous solution through an interfacial condensation reaction to synthesize an organic polymer compound.

Furthermore, there are various combinations of the first organic compound and the corresponding second compound that can be used in the present invention. Examples include polybasic acid halide and polyamine forming polyamide, and polyester. Polybasic acid halides and glycols to form polybasic acid halides, polyisocyanates and polyamines, polyisocyanates and water, polyisocyanates and glycols to form polyurethanes, etc. can be used. Furthermore, various non-aqueous solvents can be used as the solvent for the first organic compound.

The ceramic raw materials to be mixed into the first organic compound to form the slurry include alumina, zirconia, etc. containing various additives.
These include oxide materials such as mullite, spinel, and titania, nitride materials such as silicon nitride, alpha or beta sialon, carbide materials and carbonitride materials such as silicon carbide, boron carbide, and titanium carbide. Even raw materials that react and cause hydration coagulation can be used.

[Function] The production method of the present invention involves using a slurry in which the required ceramic raw material is dispersed in a solution of a water-insoluble first organic compound;
It is dropped into an aqueous solution of a second compound that forms an organic polymer substance through an interfacial polymerization reaction with the first organic compound, and the spherical slurry surface instantly forms an organic polymer film through an interfacial polymerization reaction. Ceramic spheres are obtained.

According to this manufacturing method, the solution of mixing ceramic raw materials to form a slurry is a non-aqueous solution of organic matter, so it cannot be applied to oxide ceramics that solidify when exposed to water or non-oxide ceramics that cause a decomposition reaction. It is possible.

[Example] Examples of the present invention will be described below.

Example 1 An alumina-based material and a zirconia-based material to which magnesia, which is easily hydrated and solidified in an aqueous solution, is added will be explained.

Add 50 ml of adipic acid dichloride to 1010 ml of chloroform.
Ceramic raw materials having the composition shown in Table 1 are added to a solution dissolved in 0O and kneaded in a ball mill to form a slurry. Each raw material used had a purity of 99% or more and an average particle size of 1 μm or less. Using a syringe, add 50 g of hexamethylene diamine and 35 g of sodium hydroxide to 1010 g of water.
When dropped into an aqueous solution dissolved in 0O, a spherical ceramic sphere body is obtained by an interfacial polymerization reaction. The base material is taken out by filtration, dried, and then fired in the air at each temperature shown in Table 1 for 2 hours to obtain alumina spheres and zirconia spheres.

Table 1 shows the density of ceramic spheres obtained by press molding using the same composition as the alumina spheres and zirconia spheres obtained by the above manufacturing method, and the densities of ceramic spheres obtained by the method of the present invention are almost the same as those by press molding. The density is obtained. Further, in this example, an alumina ball base and a zirconia ball base having a diameter of 2 mm were obtained.

- Margins below Table 1 Example 2 Silicon nitride systems and sialon systems containing silicon nitride and aluminum nitride, which tend to cause decomposition reactions in aqueous solutions, will be explained.

A ceramic ball base was obtained in the same manner as in Example 1 using ceramic raw materials having the composition shown in Table 2, and then fired in a nitrogen gas atmosphere at the temperature shown in Table 2 for 4 hours to form silicon nitride balls and sialon balls. can get. As raw materials, silicon nitride and aluminum nitride have an average particle size of 1 μm or less and anionic impurities of 0. 5% by weight or less, alumina, magnesia, and ittria have a purity of 99% or more, and an average particle size of 1
A diameter of μm or more was used.

Table 2 shows the densities of silicon nitride spheres and sialon spheres obtained by press molding using the same formulation as those obtained by the above manufacturing method. Almost the same density was obtained. Also,
In this example, silicon nitride sphere bodies and sialon sphere bodies with a diameter of 2 mm were obtained.

1 below margin 1 Table 2 [Effects of the invention] As described above, according to the present invention, a slurry in which a ceramic raw material of a required composition is dispersed in a solution containing a first organic compound is mixed with a first organic compound. Ceramic spheres are manufactured by dripping into an aqueous solution of a second compound that undergoes an interfacial polymerization reaction, so even oxide ceramics, which hydrate and solidify when exposed to water, and non-oxide ceramics, which undergo a decomposition reaction, can be made compact at low cost. A base material that can be used as a ceramic sphere can be manufactured.

Claims (3)

[Claims] (1) A slurry in which ceramic sphere raw materials are dispersed in a solution of a first water-insoluble organic compound is placed in an aqueous solution of a second compound that forms an organic polymer substance through an interfacial polymerization reaction with the first organic compound. A method for manufacturing a ceramic sphere characterized by dripping. (2) The combination of the first organic compound and the corresponding second compound consists of a polybasic acid halide and a polyamine, a polybasic acid halide and a glycol, a polyisocyanate and a polyamine, a polyisocyanate and water, and a polyisocyanate and a glycol. The method for manufacturing a ceramic ball according to claim 1, wherein the ceramic ball is selected from the group consisting of: (3) Ceramic raw materials include oxide materials such as alumina, zirconia, mullite, spinel, and titania containing various additives, nitride materials such as silicon nitride, α or β sialon, silicon carbide, boron carbide, titanium carbide, etc. 2. The method for manufacturing a ceramic ball according to claim 1, wherein the ceramic ball is selected from carbide-based materials and carbonitride-based materials.