JPS59174569A - Manufacture of ceramic products - 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 The present invention relates to a new and useful manufacturing method for ceramic products, and more particularly, to a method using a mixture of a thermosetting resin and a thermoplastic resin in a specific mixing ratio as a binder. , and a manufacturing method comprising shaping a mixture of such a binder and raw materials for ceramic production, followed by firing and sintering.

Ceramic products are generally obtained by mixing raw materials for ceramic production with a binding material such as resin, molding, degreasing, and then sintering. The binder component to be used has an important and close relationship with the subsequent degreasing process, and depending on the composition, it may not be possible to degrease sufficiently, or as a result of rapid degreasing, the molded product may deteriorate. It is often seen that these materials have an adverse effect, such as causing various defects.

In particular, when the molded product is large, the wall thickness has increased, or when a large amount of binding material is required such as in injection molding, Japanese Patent Publication No. 36-7883 or 47-49964 or JP-A-41J-183
If so-called conventional binders such as styrene-butadiene copolymer, polyethylene, polypropylene, or polystyrene as disclosed in Publication No. 05 are used, problems such as discoloration, cracks, blisters, and cracks may occur during the degreasing process. or even during sintering, such deformation,
It has been extremely difficult to obtain good quality ceramic products because of cracks, cracks, and reduced dimensional accuracy.

However, as a result of intensive research in view of the above-mentioned drawbacks of conventional binding materials, the present inventors have found that thermosetting resin and thermoplastic resin in a specific ratio are essential components of the binding material. When using a mixture of The present invention has been completed by showing that it is possible to obtain a good ceramic product that does not exhibit defects such as this or other seeds even when exposed to heat.

Of course, the present invention uses 5 to 5 parts of a binder mixture having a weight mixing ratio of thermosetting resin and thermoplastic resin of 60/40 to 5/95 to 100 parts by weight of the raw material for producing ceramics.
We are developing a manufacturing method for ceramic products that consists of mixing 50 parts by weight, then shaping into a desired shape, then firing to remove the binder, and sintering the raw materials for ceramic manufacturing. It is something that

Here, the raw materials for producing ceramics listed in ζ are:
Oxides such as alumina, mullite, zirconia, cordierite, sterite, humelstellite, beryllia, magnesia, ditania, lanthania, thoria or hafnia; carbides such as silicon carbide, tungsten carbide, niobium carbide or thorium carbide: Alternatively, it is mainly made of a type of general-purpose ceramic raw material including nitrides such as silicon nitride, aluminum nitride, or boron nitride, or a mixture thereof, and further known materials such as magnesium carbonate, calcium carbonate, yttrium oxide, cerium oxide, or silicic acid. Conventional sintering aids and Lt20
．． These include those to which various additives such as BaO, Ta2O3, Pt, or Pd that change electrical properties are added.

On the other hand, typical thermosetting resins include epoxy resin, phenol resin, urea resin, melamine resin,
Examples of such thermosetting resins include guanamine resin, unsaturated polyester resin, unsaturated epoxy ester resin, unsaturated epoxy urethane resin, thermosetting acrylic resin, and thermosetting urethane resin. ,
A curing agent, a crosslinking agent, a mold release agent, etc. commonly used in each molding material can also be used in combination.

Typical thermoplastic resins include addition polymers such as polyethylene, polypropylene, polystyrene, polyvinyl acetate, or ethylene-vinyl acetate copolymers, and condensation polymers such as saturated polyester, polyamide, polycarbonate, and polyacetylene. and so on.

Assuming that the raw materials for producing ceramics and the resin-based binder listed above are essential components, 5 to 50 parts by weight of the latter component, that is, the resin-based binder, to 100 parts by weight of the former component, that is, the ceramic raw material. parts, preferably 10 to 4
In this case, the thermosetting resin and thermoplastic resin in the latter component, the resin-based binder, are used in a ratio of 60/40 to 5/95, preferably 40/95.
It is preferable to use a weight mixing ratio of 60 to 10/90.

When carrying out the method of the present invention, each of the above-mentioned ceramic raw materials and! ! Mixing with the fat-based binder is accomplished, for example, by melting and kneading it in a -screw or twin-screw extruder, and thus a homogeneous mixture is obtained. In addition to additives such as animal and vegetable oils, additives such as plasticizers and mold release agents can be used as long as they do not reduce the effects of the present invention. Paraffin, natural paraffin, micro wax, polyethylene wax, lauric acid, stearic acid, valmitic acid, myristic acid, erucylamide, hardened beef tallow amide, oleic acid amide, stearic acid amide, methylene bis stearamide, ethylene bis stearamide ,
Butyl stearate, glycerin monostearate,
Ethylene glycol monostearate, polyethylene glycol monostearate, cetyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol, zinc stearate, calcium stearate, lead stearate, octadecylamine, primary tallow amine, turpentine oil, corn Waxes, fats and oils, such as oil, menhaden oil, pentene oil, pine oil, coconut oil, castor oil, hydrogenated peanut oil or light oil, or derivatives thereof; glycerin, ethylene glycol, propylene dalicol, isobrobyl alniol , cellulose acetate, perchlorethylene, diethyl phthalate, dibutyl phthalate, or diethyl phthalate, or solvents or plasticizers.

Next, the above-mentioned molding means mainly include a screw type or plunger type injection molding machine, an extrusion molding machine, and a one-portion molding machine.

In addition, in the firing (degreasing) process described above, 1. Using various heating devices such as hot air dryers, electric furnaces, and gas furnaces, the temperature range is from 50°C to 700°C in air or a reducing atmosphere. The resin-based binder is removed by heating at a temperature increase rate of 2° C. to 100° C. per hour.

By the way, in the conventional method, troubles such as deformation, cracking, blistering, and cracking easily occur during the firing (degreasing) process, and it is extremely difficult to manufacture thick molded products of 71 or more or large molded products. As long as the method of the present invention is followed, all of the defects and shortcomings in the conventional method are improved or eliminated, and as a result, the stability of dimensional accuracy is greatly improved even after the sintering process. This will give you a lot of weight.

Next, the present invention will be specifically explained with reference to Examples, and unless otherwise specified, all parts and percentages are based on weight.

Example 1 To 100 parts of ceramic powder containing 95% alumina powder, 5% calcium carbonate, and 60% particles with a particle size of 5 μm or less, 20 parts of polystyrene manufactured by Ink Chemical Industries,
5 parts of J (epoxy resin manufactured by the same company) and 140
°P (60 °C) 1 part of paraffin wax, 17
After heating to 0 to 190°C and kneading, pulverize to a maximum particle size of 3 to 5 yen or less to obtain 1 liter of molding material.
I was angry.

Next, under the conditions that the injection pressure is 700 to 1 OOO kg/cJ and the molding temperature is 160 to 190°C, 10X1
A square prism of 0x20 was formed.

After that, this molded product was placed in an electric furnace, and the temperature inside the furnace was first raised to 70°C over 2 hours, and then the temperature was raised from 70°C to 300°C at a rate of 7 to 8°C per hour. The temperature was further increased from 300℃ to 700℃ at a rate of 20 to 30℃ per hour to remove organic components, and then heated to 1600℃.
After sintering, a good ceramic product was obtained.

Example 2 Ceramic containing 77% zircon, 7% feldspar, 8% talc, 5% Honbushi clay, and 3%+1 l'uite, and 90% of particles with a particle size of 5 μm or less 15 parts of low density polyethylene to 100 parts of powder
parts, 5 parts of [Evicron 7050J (same company product)], 4 parts of stearic acid and 130°F (54.4°C)
A molding material was prepared by heating and kneading 4 parts of paraffin wax in an extruder at a temperature of 170 DEG to 190 DEG C., and then pulverizing it into a powder having a particle size of 3 to 5 grains or less.

Next, the injection pressure was 600 to 800 kg/c+J, and the q molding temperature was 150 to 180°C.
A square column of x20fi was formed.

After that, this molded product was placed in an electric furnace, and the temperature inside the furnace was first raised to 80°C over 2 hours, and then the temperature was raised from 80°C to 30°C.
The temperature was raised to 50°C at a rate of 6 to 7°C per hour, and then from 350°C to 600°C at a rate of 20 to 30°C per hour to remove organic components, and then heated to 1400°C.
When sintered, a good ceramic product was obtained.

Example 3 20 parts of atactic polypropylene was added to 100 parts of ceramic raw powder containing 90% alumina powder, 5% calcium carbonate, 5% magnesium carbonate, and 60% particles with a particle size of 5 μm or less. A molding material was prepared by kneading 20 parts of Barcam 4331J (a phenolic resin manufactured by Dainippon Ink & Chemicals) and 1 part of butyl stearate at 110 to 120°C.

Next, this molding material was first heated to 120°C by high frequency heating.
When heated to γ, the pressure will be 500-700. ky/c-
and under the conditions that the molding temperature is 150 to 170°C, l
0XIOx20 Molded and sealed into a dragon prism.

Thereafter, n organic components were removed in the same manner as in Example 1.
After sintering, a good ceramic product was obtained.

Claims (1)

[Claims] The weight mixing ratio of thermosetting resin and thermoplastic resin is 60/40 to 100% of the raw material for producing ceramics.
A mixture of 5/95 binder is mixed in a range of 5 to 50 parts by weight, then formed into a desired shape, and then fired to remove the binder and sinter the raw material for producing ceramics. A method for manufacturing ceramic products characterized by: