JPH01100058A - Binder for ceramic molding and production of ceramic molded article - Google Patents

Abstract

PURPOSE:To contrive to improve strength of ceramic green molded article and to prevent occurrence of cracking in winding thereof, by specifying the composition of a binder comprising a methacrylic resin prepared by copolymerization of a specific monomer mixture. CONSTITUTION:The binder consists of a methacrylic resin obtained by copolymerizing a monomer concentration containing >=50wt.% monomer a, >=0.3wt.% monomer b and optionally monomer c based on sum of all the monomers. The amount of the monomer b in the monomer mixture is <=1.0wt.% in a binder for injection molding and <=5.0wt.% in a molding binder except for the injection molding. The monomer a is an alkyl methacrylate, the monomer b is a crosslinkable monomer containing two or more radically polymerizable double bonds per molecule and the monomer c is a radically polymerizable monomer except the components a and b. The binder is blended with ceramic powder, the mixture is molded into a green molded article, which is sintered to produce a ceramic molded article.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The present invention provides a ceramic molding binder suitable for molding ceramics by press molding, extrusion molding, injection molding, etc., and the use of the binder. The present invention relates to a method for producing a ceramic molded body.

[Conventional technology]

In recent years, ceramic molded bodies have become widely used as electronic and engineering components.

A green molded body is usually produced by forming a liquid or solid mixture of ceramic powder and a binder (hereinafter referred to as a ceramic compound) by casting, press molding, extrusion molding, injection molding, etc. The molded body is then sintered at a high temperature.

To explain in more detail the method for manufacturing green molded bodies, which uses a ceramic compound that is solid at room temperature as a raw material by molding methods such as press molding, extrusion molding, and injection molding, the raw material compound is heated in a molding machine. A green molded body is molded in a state in which fluidity is imparted to the molded body, and then the molded body is gradually heated to decompose and remove the binder component, that is, degrease the green molded body.
A commonly used method is to sinter at a predetermined temperature.

Conventionally, polyethylene, Thermoplastic resins such as atactic polypropylene, ethylene-vinyl acetate copolymer or polystyrene have been used.

However, when manufacturing complex-shaped ceramic products by injection molding, using the above-mentioned conventional binder made of thermoplastic resin, the fluidity within the mold is still insufficient, resulting in green molding. Weld lines were likely to occur in the molded product, and the yield rate was low. In addition, in order to prevent the occurrence of weld lines, if a binder with a low softening point and good fluidity is used, the strength of the resulting green molded product will be weak (and easily deformed), making it particularly difficult to release it from the mold. Defects such as cracks and cracks were likely to occur during cleaning and degreasing.

Furthermore, when forming long materials such as wire rods or sheet materials by methods such as press molding or extrusion molding, the molded product obtained from the conventional ceramic compound containing a binder cannot be rolled or bent. There is a problem that the green molded body cannot follow the deformation and cracks appear in the green molded body, and it is difficult to wind up the above-mentioned linear material or sheet-like material into a coil shape or a cool shape.

On the other hand, for example, YBa, Cu, o, x (however, X
is a rare earth/copper oxide-based superconducting material (also referred to as a ceramic-based superconducting material), which is a type of ceramic, and is represented by the composition formula 0 (x (a number within the range of α8))
Compared to alloy-based superconducting materials such as niobium-titanium alloys, which have been known for a long time, superconducting materials have attracted attention from various quarters because they have higher critical temperatures. Practical as explained in Materials J, May 1988 issue, page 24, etc.

One of the important issues to consider is the production of wire rods, and various methods of making wire rods are currently being considered.

As a specific method for making the rare earth/copper oxide superconducting material into a wire, for example, a powder obtained by calcining Y, 01, B3co, ' and CuO is heated with a silver sheet.

There are known methods in which the powder is filled into a wire rod by rolling, or mixed with an organic binder and then formed into a wire rod by extrusion molding, followed by sintering at a high temperature. Extrusion molding is a simpler method than the method using a silver sheath, so there are great expectations for the development of superconducting wires by extrusion molding, but as mentioned above, using conventional binders makes it difficult to Currently, its application is limited because it is difficult to wind it up.

(B) Structure of the invention [Means for solving the problem] As a result of intensive studies to solve the above problem, the present inventors have developed a polymer having an alkyl methacrylate monomer as a main structural unit and having a crosslinked structure. It has been discovered that this polymer has excellent degreasing properties and is extremely effective in increasing the strength of green molded products in mix injection molding using a binder made of this polymer. The green molded body is
The inventors have discovered that even when wound into a coil or roll, no cracks occur, leading to the completion of the present invention.

That is, in the first aspect of the present invention, the amount of the following monomer (a) is 50% by weight or more and the amount of the following monomer (b) is α3 weight % based on the total amount of all monomers. The above is a binder for ceramic injection molding made of a methacrylic resin obtained by copolymerizing a monomer mixture which may optionally contain the following monomer (c), wherein the monomer (c) in the monomer mixture is The amount of b) is 10% by weight or less in a binder for injection molding, and 5.0% by weight or less in a binder for molding other than injection molding. ): Alkyl methacrylate.

Monomer (b): A crosslinkable monomer having at least two radically polymerizable double bonds per molecule.

Monomer (c); a radically polymerizable monomer other than the above components (al and (b)).

A second invention is a method for manufacturing a ceramic molded body, which comprises molding and sintering a composition comprising the binder and ceramic powder according to claim 1.

The present invention will be explained in more detail below. Monomers (al is an alkyl group having 1 to 12 carbon atoms) which are constituent components of the monomer mixture subjected to polymerization to obtain the methacrylic resin of the present invention. Examples include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate and lauryl methacrylate. These alkyl methacrylates can be used alone or in combination, but the amount used is based on the total amount of all monomers used for polymerization from the viewpoint of ease of decomposition in the degreasing process. Based on the standard, at least 50% by weight is required. Preferred alkyl methacrylates include:
Lower alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate are exemplified from the viewpoint of degreasing properties and strength of green molded bodies.

Specific examples of the crosslinkable monomer (monomer (b)) having at least two or more radically polymerizable double bonds per molecule, which is another essential monomer in the present invention, include:
For example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene Dimethacrylates and diacrylates such as glycol diacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, trimethacrylates and triacrylates such as trimethylolpropane triacrylate,
Tetramethacrylates and tetraacrylates such as pentaerythritol tetramethacrylate, Aronix M-6300, M-8060 manufactured by Toagosei Chemical Co., Ltd.
Examples include polyester polymethacrylate and polyester polyacrylate such as K, as well as allyl methacrylate, diallyl phthalate, divinylbenzene, and the like.

The proportion of the crosslinkable monomer used in the monomer mixture based on the total amount of all monomers varies depending on the method of ceramic molding using the binder made of methacrylic resin. When the method is injection molding, it is 0.3 to 0.3% by weight, and in molding methods other than injection molding, it is α3 to 5.0% by weight. If α is less than 5% by weight, the solvent insolubilization rate, which indicates the degree of crosslinking of the resulting methacrylic resin, will be less than 30% by weight, and the green molded product molded from the binder made of such resin will have weak mechanical strength and will be injection molded. Deformation, cracks, cracks, etc. may occur when the material is released from the mold, and sheet materials and wire materials formed by press molding or extrusion molding are susceptible to bending and cannot be wound up.

On the other hand, if it exceeds 1.0% by weight, the fluidity of the ceramic compound will be insufficient, and it will not smoothly enter the inside of the injection mold, making it impossible to obtain a green molded product with a specified shape. Furthermore, if it exceeds 5.0% by weight, it becomes difficult to mix the ceramic and the binder uniformly, making it unsuitable for molding methods other than injection molding.

Furthermore, the monomer (a) and monomer (b) may be added as necessary.
Examples of radical copolymerizable monomers that can be used with monomer C) include vinyl acetate, acrylonitrile, styrene, α-methylstyrene, vinyl chloride, vinylidene chloride, methyl acrylate, ethyl acrylate, Propyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, tetrahydrofuryl acrylate, lauryl acrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, Examples include hydroxypropyl methacrylate, glycidyl methacrylate, acrylamide, ithacrylamide, N-methylolacrylamide, etc., and the preferred amount used is 40% by weight or less based on the total amount of all monomers. Among these copolymerizable monomers, styrene and methacrylic acid are preferred from the viewpoint of degreasing properties and strength of green molded products. When the copolymerizable monomer is styrene, the preferred amount used is 10 to 40% by weight, based on the total amount of all monomers subjected to polymerization, and in the case of methacrylic acid, it is 1 to 5% by weight. be.゛The methacrylic resin in the present invention is a monomer mixture consisting of the lower alkyl methacrylate, a crosslinkable monomer, and other radical copolymerizable monomers as necessary,
It can be easily produced by radical copolymerization using known methods such as suspension polymerization, emulsion polymerization, or solution polymerization.

The binder for ceramic and plastic molding of the present invention is made of the above-mentioned methacrylic resin, and although it exhibits excellent effects even when the resin alone is used, other molding aids such as resins, plasticizers, organic Solvents, lubricants, mold release agents, waxes and other auxiliary agents may be used in combination. Examples of resins that can be used in combination include polystyrene, polyethylene, polypropylene, atactic polypropylene, ethylene/vinyl acetate copolymer, and ethylene/ethyl acrylate copolymer.

Examples of plasticizers that can be used include heptatal acid esters such as diethyl hetatalate and dibutyl phthalate, fatty acid esters such as butyl stearate, liquid polybutene and polyalkylene oxides such as polyoxybu-a-pylene glycol, polypropylene glycol, and polyethylene glycol. It will be done.

Further, organic solvents can be used for the purpose of lowering the melt viscosity of the binder in the same manner as the above-mentioned plasticizers, and specific examples include butyl alcohol, butyl acetate, toluene, xylene, and cellosolve acetate.

Examples of lubricants or mold release agents include stearic acid,
Examples of fatty acids such as oleic acid and their esters include aluminum stearate, magnesium stearate, mineral oil, etc. Waxes include paraffin wax, microcrystalline wax, carnapawa, camphor tree wax, beeswax, etc. Examples of the auxiliary agents include anthracene, naphthalene, benzoic acid, adamantane, rapeseed oil, and surfactants.

Incidentally, the solvent insolubilization rate, which is a measure of the crosslinkability of the methacrylic resin in the present invention, means the solvent insolubilization rate measured by the method shown below.

That is, dry resin 2y- was weighed, reagent grade tetrahydrofuran 40) was added to it, and the mixture was left under a tightly stopper at a temperature of 25 ± 1°C for 72 hours, and then filtered with a filter.
After the filtrate was evaporated to dryness under reduced pressure at 80°C, the weight was measured, and the solvent insolubilization rate was determined from the following formula.

S-B A: Solvent insolubilization rate (chi) A=-
x 100 (@B: Solvent soluble content (FAS
S: Sample weight (Meanwhile) Typical ceramics and materials that can be processed into sintered bodies using the binder of the present invention include alumina, zirconia, barium titanate, titanium oxide, cordierite, lead zirconate titanate, and beryllium oxide. and oxide ceramics such as yttrium oxide,
Non-oxide ceramics such as carbon dioxide, silicon carbide, tungsten carbide, titanium carbide, silicon nitride, aluminum nitride, boron nitride, titanium nitride, and sialon;
Cu.

0fu8, 5rBa, (:u, ot-,,E
r13a, (::u.

0? -X, B1Ca5rcu, Ox and La,
, B jll.

Ceramic superconducting materials represented by compositional formulas such as Cu, O, -8, etc. may be mentioned.

All of the above ceramics are kneaded with a binder as a powder with a particle size of about 0.1 to 10 μm.

Next, a method for manufacturing a ceramic or wax molded body using the binder of the present invention will be explained.

Mixing of the ceramic powder and the binder can be carried out at 80 to 190°C using a kneading machine such as Toyo Seiki's Labo Plasto Mill, or in the cylinder of an insertion molding machine.
It can be carried out under moderate temperature conditions.

The blending ratio of cerami, diasu powder, and binder is 90 to 75% by weight of cerami, diasu powder, and 10 to 25% by weight of binder.
Weight-degree is appropriate.

The ceramic compound obtained by the above method can be injection molded at an injection temperature of about 170°C and a mold temperature of about 50°C, and can be made into a wire or sheet material by extrusion molding or press molding at about 150°C. Obtainable. The green molded body thus obtained is heated in air at a heating rate of, for example, 5°C/hour.
After degreasing by heating to 00°C K, a ceramic molded body can be produced by sintering for 6 to 20 hours at a sintering temperature suitable for the ceramic used, usually within the range of 750 to 1600°C. .

In addition, when manufacturing a molded body of ceramic-based superconducting material, superconducting material powder can be used as ceramic or clay powder, but at the stage of manufacturing superconducting material from multiple raw materials such as metal oxides and metal salts, It is more efficient to use the powder of the calcined material of the raw material mixture, which is an intermediate component, in order to obtain the desired product.

That is, for example, the Y-Ba-Cu-0 superconducting material, which is the most typical ceramic-based superconducting material, is usually made from the raw materials yttoria (y, O,) and barium carbonate (BaCO,).
Either pulverize oxidized steel (cube), then mix each raw material according to the composition ratio, add ethanol etc. to it and knead thoroughly (referred to as wet mixing method or powder method), or A powder obtained by a method in which a nitrate solution of 1 is prepared, 5-acid (HCOOH) and an aqueous solution are added to the solution, and each metal is precipitated as each oxalate (referred to as coprecipitation method). body mixture, 800
After calcination at ~950℃ for about 20 hours, the temperature of 900~100
Manufactured by sintering at 0°C (for example, TECNOLOGY AND MARKET 198
7, No. 9, pp. 49-60), when the calcined body is obtained, the calcined body is preferably turned into a powder with a particle size of 1 μm or less, and a mixture of this powder and the binder of the present invention is formed into a desired shape. By molding a molded body, the molded body can be manufactured without the trouble of performing main sintering twice.

(c) Effects of the Invention The green molded body molded using the binder of the present invention has K because the binder is made of a methacrylic resin into which a crosslinked structure has been appropriately introduced.

It has strong mechanical strength, and as a result, defects such as deformation and cracking are less likely to occur when released from a mold in injection molding, and long materials and sheets formed by extrusion molding, press molding, etc. If the material is at a certain temperature, it is possible to perform secondary processing such as winding or bending.

〔Example〕

Next, the present invention will be explained in more detail by showing reference examples, examples, and comparative examples of the present invention. In addition, all parts on each side below mean parts by weight.

Reference Examples 1 to 13 Table 1 shows the compositions of monomer mixtures used to obtain various methacrylic resins for binders. The method for synthesizing the resin will be described below using Reference Example 1 as a representative example.

98 parts of butyl methacrylate, 2 parts of methacrylic acid, 4 parts of tetraethylene glycol dimethacrylate α, 2.2
A mixed solution containing 1 part of '-azobisisobutyronitrile is prepared in advance.

A 4-bottle flask containing an aqueous medium was heated to 80°C in a water bath, and 1 part of polyvinyl alcohol was added as a dispersant.The interior of the flask was replaced with nitrogen.While stirring at 20 rpm, the mixed solution was charged and polymerized for 7 hours. The obtained polymer was washed with water and dried.

Regarding the method of synthesizing the resins in Reference Examples 2 to 13, the same method as in Reference Example 1 was employed except that the monomer mixtures were different. A suspension polymerization method was used as the polymerization method.

The solvent insolubilization rates of the resins synthesized on each side are shown in Table 1, respectively.

Examples 1 to 8 Zirconia H8Y-3 with an average particle diameter of 0.6 μm,
0 (manufactured by Daiichi Kigenso Kagaku Kogyo ■) or alumina Al-1
608G (manufactured by Showa Light Metal) Ceramic, Kusu Powder 8
5 parts, 9 parts of methacrylic resin with a solvent insolubilization rate in the range of 50 to 80% by weight, and 155 parts of paraffin wax.
Add 3.0 parts of F (manufactured by Nippon Seiro) and 40 parts of stearic acid, mix in a mixing machine at 170°C, 50 rpm for 1 hour, measure the torque value (torque at the time of mixing) and
Shown in the table. The kneading properties were fair to good, and the mixture was uniformly mixed.

Examples 9 to 10 Using 85.8 parts of zirconia H8Y-3,0, 5.7 parts of the methacrylic resin shown in Table 3, and sunwax (low molecular weight polyethylene, Sanyo Chemical Industries ■I!
Ld part, Viscol (low molecular weight polypropylene, manufactured by Sanyo Ibisei Kogyo ■) 52 parts, paraffin wax 155F1
9 parts of stearic acid, 1.4 parts of stearic acid and 0.4 parts of diethyl phthalate were added and kneaded in a kneader, and the average particle size was 2 to 310.
Make pellets of E, and mold these pellets with an injection molding machine.
Injection molding was performed at an injection temperature of 170° C. and a mold temperature of 50° C. to form a test piece having a width of 5 xx, a height of 5 tm, and a length of 5 cIL. The thus obtained test piece was heated to 400° C. at a heating rate of 5° C./Hr to degrease it. After cooling, the mixture was heated in a sintering furnace at 1550° C. for 8 hours to produce a sintered product. The workability of injection molding, the degreasability of the molded product, and the sintered product were all good.

Comparative Examples 1 to 3 The kneading properties of methacrylic resins having a solvent insolubilization rate of 0% and 95% by weight were examined in the same manner as in Examples 1 to 7, and the results are shown in Table 2. In Comparative Example 1 using a methacrylic resin with a solvent insolubilization rate of 0% by weight,
The kneaded product was too soft and had poor wire cross-talk properties. In Comparative Example 2 using a methacrylic resin with a solvent insolubilization rate of 95% by weight, the resin did not melt during cross-crossing and was mixed non-uniformly, resulting in only an inferior kneaded product.

Injection molding was performed using a methacrylic resin with a solvent insolubilization rate of 0% by weight in the same manner as in Examples 9 and 10, and the degreasing property and sinterability were examined (Comparative Example 3). Regarding the workability of injection molding,
Defects such as deformation, cracks, and cracks occurred during demolding, and the yield was low at 40%. Cracks, cracks, etc. occurred during degreasing, and cracks inside the molded product occurred during sintering, making it difficult to obtain anything that passed the test.

Example 11 Zirconia H8Y-3,0 as ceramic powder
To this, 87 parts of methacrylic resin, 4 parts of paraffin wax 155F4 stearic acid, and 0.3 parts of polypropylene glycol were added, and the same operations as in Examples 1 to 8 were performed to determine the torque value, crosstalk property, and melt viscosity. As a result of the measurement, the torque value was 9 m for A42, crosstalk;
Good, melt viscosity: 2030 poise.

Table 3 1) Good injection workability: Low injection molding pressure, easy molding, good release properties from the mold, no defects such as deformation or cracking.

2) Good degreasing properties: There is no sudden decomposition or generation of abnormal gas at a given temperature, and there are no defects such as cracks.

3) Good sinterability: No cracking or collapse during sintering.

Example 12 A calcined body of y-na-cu/0-based superconducting material was manufactured by the following method.

In other words, Universal Ball Mill UB-3 manufactured by Yamato Scientific Corporation is equipped with an alumina pot and an alumina ball.
1, a slurry obtained by pulverizing and mixing the following substances for 72 hours was dried at 80°C for 48 hours, and then heated in a 940°C furnace for 20 hours to produce a Y-Ba-Cu/0-based superconducting material. A calcined body was manufactured.

Yttrium oxide...112.92g (Yt
Ox) Barium carbonate・・・・・・・・・594.74g
(BaCO8) Copper oxide・・・・・・・・・・・・・・・・・・-2
38.62g (cube) Ethanol 375.
50g, then 600g of the above calcined body and 300g of ethanol
g and 7 using the same ball mill as used earlier.
After grinding for 2 hours and drying the resulting slurry at 80°C for 48 hours, it was further ground for 72 hours until the average particle size was 0.58.
It was made into a powder of μm size.

For 200g of powder of the calcined body of the above superconducting material [Reference Example 1]
A heating kneading machine Labo Plastomill (newly manufactured by Toyo Seiki Seisakusho) K was charged with 30 g of the resin A obtained in step 1, and the mixture was kneaded at 150° C. for 1 hour to obtain a cerami-cushion compound. The ceramic compound was put into an extrusion molding machine, and 1
It was extruded into a wire rod with a diameter of 2 m at 50°C. The wire rod in a heated state immediately after extrusion could be wound up. When the wire was cooled to room temperature and heated to around 80°C, it could be easily wound and bent. Furthermore, by pulling the wire while heating it to around 80°C, it was possible to elongate it to a diameter of about 0.5 m.

The wire rod formed by the above method was heated to 500°C at a heating rate of 10°C/hour, then heated to 960°C at a heating rate of 100°C/hour, and maintained at that temperature for 20 hours. The sintering was completed, and the mixture was cooled to room temperature at a cooling rate of 40° C./hour to produce a linear sintered body of Y-Ba-Cu.0-based superconducting material.

As a result of examining the superconductivity of the obtained linear sintered body, it was confirmed that it was completely diamagnetic at 77°K, which is the boiling point of liquid nitrogen, and had an electrical resistance of aS.

Example 13 Ceramic consisting of the powder of the calcined body of the Y-Ba-Cu/0-based superconducting material prepared in Example 12 and resin A,
150℃ using a press molding machine
A sheet with a thickness of 0.5 m was molded.

The obtained sheet could be easily fabricated into any shape by heating it to around 80°C.

It was sintered in the same manner as in Example 12 to obtain a sheet-like sintered body. The superconductivity of the sintered body was equivalent to that of the linear sintered body in Example 12.

Examples 14 to 15 In Example 12, resin C (Example 14) and resin D (Example 1) were used as the binder.
Using Example 5), a ceramic compound was obtained under all the same conditions as in Example 12, and a linear green molded body was molded from the compound. The obtained linear green molded product has the same properties as the linear green molded product obtained in Example 12, that is, it can be wound up and pulled when heated to around 80°C, and is a wire material that is thinner than K. It was confirmed that it has the property of being able to be stretched.

Further, a sheet-like green molded body was formed by press molding in the same manner as in Example 15 using the above two types of ceramic compounds. It was confirmed that the obtained sheet-like green molded product had properties equivalent to those of the sheet-like green molded product obtained in Example 13.

Next, each molded body was sintered by the same method as in Example 12 to obtain a sintered body of superconducting material. The evaluation results of the superconductivity of the obtained sintered bodies were equivalent to the superconductivity of the sintered bodies obtained in Examples 12 and 13.

Examples 16 to 18 Instead of resin A used as a binder in Example 12, resin B (Example 16), resin K (Example 17)
, and using resin L (Example 18), y-na-c
Ceramics were prepared under the same conditions as in Example 12, except that the temperature at which the u-0 superconducting material was kneaded with the calcined powder was 160°C in Example 16 and 180°C in Examples 17 and 18. I got the compound.

Using the obtained ceramic, Cuscomparand, Example 12
And under the same conditions as in Example 15, extrusion molding and press molding were performed to form linear green molded bodies and sheet-shaped green molded bodies. Each of the obtained green molded bodies had properties equivalent to those of the green molded bodies in Examples 12 to 15.

Example 19 A mixture containing 200 g of the powder of the calcined Y-Ba-Cu/0-based superconducting material obtained in Example 12, 40 g of resin A, and 10 g of diethyl phthalate was kneaded at 140°C for 1 hour. A ceramic compound in which each component was uniformly mixed was obtained.

It was found that the kneading temperature could be lowered by adding the plasticizer diethyl phthalate.

Example 20 Instead of the binder consisting of 40 g of resin A and 10 g of diethyl phthalate in Example 19, a binder consisting of 20 g of resin A and 60 g of Acrift CM-5004 (ethylene-methyl methacrylate copolymer) manufactured by Sumitomo Chemical Co., Ltd. was used. The mixture was kneaded at 150° C. for 1 hour to obtain a ceramic compound in which each component was uniformly mixed.

It has been found that there is no problem at all even when other polymers are used in combination with the methacrylic resin in the present invention.

Comparative Example 4 Resin F was used instead of resin A used as the binder in Example 12, and other conditions were as follows.
A ceramic compound was obtained under the same conditions as in Example 12, and a linear green molded body was molded from the compound. The obtained linear green molded body with a diameter of 2 degrees was heated to 80°C.
I tried to stretch it into a wire rod with a diameter of 0.5 xw while keeping it at a constant temperature, but it broke in the middle and I could not stretch it.

In addition, the above compound can be press-molded to a thickness of 0.
．． A 5 m sheet was molded, but the sheet was mechanically weak and could not bend even slightly, resulting in cracks.

Comparative Example 5 Resin M was used in place of resin A used as the binder in Example 12 and kneaded at a mixing temperature of 180°C, but a compound in which the ceramic and camphor powder were mixed sufficiently uniformly could not be obtained. borrowed.

Claims (2)

[Claims] 1. Based on the total amount of all monomers, the following monomer (a)
The amount of monomer (b) below is 0.3% by weight or more and the amount of monomer (b) is 50% by weight or more.
A binder for ceramic injection molding made of a methacrylic resin copolymerized with a monomer mixture that is at least % by weight and may optionally contain the following monomer (c),
The amount of monomer (b) in the monomer mixture is 1.0% by weight or less in a binder for injection molding, and 5.0% by weight or less in a binder for molding other than injection molding. Binder for molding. Monomer (a); alkyl methacrylate. Monomer (b): A crosslinkable monomer having at least two radically polymerizable double bonds per molecule. Monomer (c); radical polymerizable monomer other than the above components (a) and (b) 2. A method for manufacturing a ceramic molded body, comprising molding and sintering a composition comprising the binder according to claim 1 and ceramic powder.