JPS59199570A - Ceramic forming composition and dewaxing process - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Technical field The present invention relates to ceramic molding for extrusion molding or injection molding various ceramic products.
To 1.

This relates to a method for degreasing seaweed, which involves removing superficial components from the molded grouper body using a novel method.

(B) Background of the Invention In recent years, the use of new ceramics (hereinafter referred to as 11i as ceramics) for 1s products has been expanding due to their excellent high-temperature strength. In addition to the conventional hot press, static pressure press, and press bE Il'3, the molding method is
Plastic molding methods such as extrusion molding and injection molding are gradually becoming popular because they can be molded into complex shapes and are inexpensive to produce.

In order to perform these plastic moldings, originally 11J qjl
Ceramic powder that does not have fluidity for river cattle: 1
llll: An organic binder must be added to give the shape. Conventionally, organic binders such as styrene resin, olefin resin, polybutene, methyl methacrylate, epoxy resin, and phenol have been used as organic binders.
VJ fat.

If paraffin, wax, etc. are removed from the molded body, it is later removed from the ceramic molded body (1i) to remove the three components.
a fat 1. There was a huge score of 111 points. That is, in the conventional degreasing method, the old ramic molded body is heated to a high temperature, and the laminate is removed by decomposing it.
Rinse very gently so as not to cause blisters or cracks due to decomposed gas! The degreasing process takes anywhere from several minutes to several hundred hours. Blisters appear on the molded product after removing fingers.

The frequency of generation of oxidation is relatively high, and there is no industrially satisfactory method for producing it.

(c) By using the heating means of the invention in combination, we have discovered a composition for ceramic molding and a degreasing method that does not cause blisters, cracks, etc. in a relatively short period of time. Degreasing l: f'+',
What is important is that the surface of the ceramic molded body is
The components () are gradually vaporized as a decomposed gas, and the Il
The purpose is to proceed with the decomposition to the +'i-order interior.

Heat the instep! In the method using only molten metal, controlling the progress of this decomposition is very repetitive, but in the uninvented method, it is easy to control the progress of this decomposition. The dose occurs on the irradiated surface, and the decomposition gradually moves to the inside, and the generated decomposed gas evaporates through the already formed micropaths. When the remaining organic binder component is then heated and degreased, the microbaths formed by the irradiation are present from the inside of the molded product to the surface, so the generated gas causes blisters and creases inside the molded product, resulting in polymers with methyl groups. Yes, specifically, polypropylene 7, polyisobutylene, polymethacrylate 1,
Poly-alpha-methylstyrene and the like can be used as examples. In these polymers, free radicals are generated at the ionic carbon atoms bonded to methyl groups by external radiation or electron beams, and for example, in polypropylene, radical decay as shown in (d) occurs.

The left side shows the collapse l)i+, and the right side shows the form after collapse.

~C1l2C-C112-CI-T~-2~CI-
I2-C=CI-I2+・CH~1'l
l 1CI-Tro CI5
CH3C! (3) These outer-line collapsible resins can be used alone as a ceramic binder, but in order to increase the affinity with ceramic powder (12+) and improve the fluidity during molding, it is necessary to use other known It can also be combined with Arisa binder.Other 1+ and +17 materials include existing lj
;J ingredients can be used in appropriate combination. That is, as the ceramic powder, a cemented carbide or cermet such as aluminum nonaoxide, aluminum oxide, silicon nitride, silicon carbide, or tungsten carbide can be used.
Sintering aids include magnesia, alumina, and yttrium oxide.

La-based monoxides, boron carbide, ferrous metals, etc. can be contained. Also known as a processing aid: ", y
,”'J f', lJ, slipi'jlj, ni:E!v
r'i i+J is used, saturated fat 1-1 fat (・a sum ° [11 fat), metal soap, high-j alcohol, animal and vegetable oil.

Mineral oil, synthetic ester oil, etc. can be used. Examples are given below to reduce the effects of the present invention.

Examples Example 1 For 100 parts of silicon nitride powder, 4 parts by weight of magnesia, 2 parts by weight of stearic acid, 11 parts by weight of stearic acid, 4 parts by weight of paraffin, and 20 parts by weight of low density polyethylene. (
Polyisobutycin 4-h as part and UV-degradable resin
-(parts) were added and mixed, and after melting and kneading, it was crushed into flakes, and this material was molded into a 5 x 1 film by injection molding.
2X 40 mrn ceramic composition; 1 body. Next, as a degreasing step for this ceramic molded body, it was irradiated with ultraviolet rays in the wavelength range of 600 to 4 Q nm for 10 minutes. The intensity of this ultraviolet ray was 20111"w/A・rji. After 7 days, the degreasing treatment by heating was carried out to 1 J. is 200℃-2Hr-250℃-
41-I r-350°C-4Hr-500°C-4Hr. The Cera E Tsuk molded body thus degreased was sintered at 1700'C-12Hr to obtain Ceramic D'.

When this 67 bending strength was defined as A, it was 62 no 9y.
It's ';gm'.

In 1, instead of polypropylene, 4 parts by weight of polypropylene was added and mixed as a fort external line collapsible resin, melted and kneaded, and then crushed into flakes. 1 x 12 x 402I〃l ceramic molded body! ]Ta. Next, as a degreasing process for this ceramic (molded body), irradiation with electric radiation was performed for 5 seconds to give a dose of 10 Mrad (as in Example 1).
Degreasing treatment by heating was carried out under the same conditions as above. ;j)
No problems such as blistering or cracking occurred in the ceramic molded product after the third coating.

C. Effects of the Invention According to the embodiments of the present invention, degreasing can be carried out in an extremely short time compared to conventional degreasing l', f'I'' which merely performs heat treatment. ,
It becomes possible to stably degrease a ceramic molded body without causing cracks.
Fuu Satonoben J Koshijou I Kashikushi 417-

Claims (1)

[Claims] A ceramic molding composition characterized by comprising: A ceramic molding composition characterized by containing isobutylene, polymethacrylate or polyα-methylstyrene resin. (6) Degreasing process to remove the organic binder from the molded product [In step 1, the molded product is irradiated with a beam or electron beam and reacts with it (decomposes some components,
11) A method for preparing a ceramic molding composition, which comprises: thereafter removing residual organic components by heating means.