JPH02164757A - Production of ceramic material for molding - Google Patents

Abstract

PURPOSE:To reduce the loadings of a binder necessary to mold ceramics by adding at least one part of the binder when a raw material for ceramics is ground and mixing this obtained ceramic powder with the binder. CONSTITUTION:In the case of producing ceramic material for molding wherein ceramic powder is mixed with a binder, at least one part of necessary amount of the binder is added in a stage for grinding a raw material for ceramics order to obtain the above-mentioned ceramic powder. In production of the ceramic material for molding, several to 100% binder amount necessary for molding are added in a grinding stage. Thereby the surfaces of ceramic granules are made such a state that these surfaces have been coated with the film of high molecule constituting the binder. The total amount of the binder necessary for molding can be reduced by utilizing the ceramic powder obtained in such a way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a ceramic material for molding, and in particular to a method for reducing the amount of binder contained in a ceramic material for molding. be.

[Conventional technology] Conventionally, in the manufacturing method of ceramic materials for molding,
After finishing the pulverization of the ceramic raw materials, the binder is mixed. That is, after dry or wet pulverization of ceramic raw materials, a binder is mixed in a ball mill or the like. And in press molding,
After spray drying and doctor blade molding, molding is performed after defoaming.

[Problems to be Solved by the Invention] A binder is essential for molding ceramic materials, but if there is too much binder, problems such as a decrease in molding density, increased difficulty in removing the binder, and warping of the fired body occur. is more likely to occur.

Therefore, it can be said that it is desirable to have a smaller amount of binder, but in conventional manufacturing methods, if the amount of binder is reduced,
Molding becomes difficult. Therefore, there is a limit to the reduction in the amount of binder.

Furthermore, in recent years, there has been an increasing demand for atomization of ceramic particles, but since such atomization increases the specific surface area of the particles, the amount of binder required for molding inevitably increases.

Therefore, an object of the present invention is to provide a method for manufacturing a ceramic material for molding, which can reduce the amount of binder added necessary for molding ceramics.

[Means for Solving the Problems] The present invention is directed to a method of manufacturing a ceramic material for molding in which ceramic powder and a binder are mixed. It is characterized by the adoption of countermeasures.

That is, at least a part of the required amount of binder is added in the process of pulverizing ceramic raw materials to obtain ceramic powder.

[Operations and effects of the invention] In this invention, the amount of binder required for molding is several percent to 100%.
% in the pulverizing process, the surfaces of the ceramic particles are covered with a polymer film constituting the binder. It has been found that by using the ceramic powder thus obtained, the total amount of binder required for molding can be reduced.

L Embodiment A case in which a sheet is formed from a molding ceramic material using a doctor blade will be described.

In molding such a sheet, the following steps were performed in sequence.

↑ PVB addition 0 parts + 1 part + 2 parts + (PVB amount is the weight when ceramic) ↑ PVB addition 10 parts - 7 parts - 4 parts - 10 parts of PVB powder Total PVB 10 parts 8 parts 6 parts 0 parts Among the above steps, in the "dry grinding" step, the ceramic raw material was ground using an attritor with or without adding PVB (polyvinyl butyral) as a binder at the above ratio. By this pulverization, ceramic powder with a particle size of 0.8 μm was obtained. next,
After carrying out the "ball mill wet grinding" step, PVB was added or newly added at the above ratio in the "ball mill binder mixing" step. Next, a "defoaming" process was performed, and then a "forming" process was performed using a doctor blade to obtain a ceramic sheet.

In this way, the total amount of binder, ie, the total amount of PVB, required for forming the sheet was investigated. “PVB total amount” above
As described in the column, by increasing the amount of PVB added in the "dry grinding" process from 0 parts to 1 part or even 2 parts, the total amount of PVB can be increased from 10 parts to 8 parts or even 6 parts. It was found that this can be reduced.

In addition to the above-mentioned attritor, a ball mill, a vibration mill, a grain mill, etc. may be used as the dry grinder used in the "dry grinding" process.

In addition to the above-mentioned PVB, examples of binders include MC (
methyl cellulose), CMC (carboxymethyl cellulose), PVA (polyvinyl alcohol), P
It is applicable to all conventionally used binders such as EG (polyethylene glycol), PE0 (polyethylene oxide), polyacrylic acid ester, and wax.

Further, as a molding method, in addition to doctor blade molding, press molding, extrusion molding, injection molding, and other molding methods can also be applied.

(2 others)

Claims (1)

[Claims] In the method of manufacturing a ceramic material for molding in which ceramic powder and a binder are mixed, at least a part of the required amount of the binder is added in the step of pulverizing the ceramic raw material to obtain the ceramic powder. A method for manufacturing ceramic materials for molding.