JPH01317169A - Ceramic compact and production thereof - Google Patents

Abstract

PURPOSE:To improve high-temperature strength, corrosion and oxidation resistance and mechanical workability by calcining a ceramic compact containing a binder which is a specific polysilazane. CONSTITUTION:(a) A binder which is a polysilazane having units expressed by the formula as main recurring units and 100-50000 molecular weight, preferably chain inorganic polysilazane having 600-1400 number-average molecular weight is dissolved in (b) a solvent (e.g., xylene) to provide (B) a solution of the binder, which is then mixed with (A) ceramic powder. The resultant mixture is subsequently formed to afford a ceramic compact, which is then calcined at 400-1500 deg.C to convert the binder into ceramics. Thereby, integration is carried out.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ceramic molded body and a method for producing the same, and more specifically, a ceramic molded body obtained using a binder containing a specific polysilazane-based brace ceramics polymer. In particular, the present invention relates to a ceramic molded sintered body and a method for manufacturing the same.

(Conventional Technique 4) F. Te] Conventionally, ceramic molded bodies are usually manufactured by molding using ceramic powder or slurry and sintering the molded product, since machining of ceramics is difficult.

As the molding binder, polyhinyl butyral and various other organic polymer binders are used.

Furthermore, since many ceramics such as silicon nitride and silicon carbide are difficult to sinter, densification is attempted using an appropriate sintering aid (sintering binder). For example, sintering aids such as alumina, intoria, and magnesia are used for sintering silicon nitride, and sintering aids such as boron and carbon are used for sintering silicon carbide.

On the other hand, preceramic polymers that form ceramics after firing are known, and organosilicon compounds such as polycarpodilane, polytitanocarbosilane, and polymethylsilazane have been developed, and their use as binders has also been proposed.

[Problems to be Solved by the Invention] When producing a ceramic molded body using an organic polymer binder, a process of removing the organic polymer binder (so-called degreasing process or dehindering process) is required before sintering the ceramic. ), which inevitably reduces η° productivity, and the organic polymer binder itself has no effect of promoting sintering of ceramics.

On the other hand, conventionally used sintering aids enable low-temperature sintering of ceramics by forming a glass phase. But I can't play around with it. In addition, even if a sintering aid is used, the sintering temperature is quite high, so grain growth occurs during the sintering process, reducing the strength of the sintered body.
The low productivity of high-temperature sintering cannot be denied. Moreover, the ceramic molded sintered body thus obtained is difficult to process.

On the other hand, when using a preceramic polymer as a binder, there are advantages such as no degreasing process is required and low temperature firing is possible. Due to the low yield, there is a limit to the density and strength of the ceramic molded body that can be obtained. Further, in particular, polycarbonane, polytitanocarbosilane, and the like have the disadvantage that excessive carbon remains, causing structural defects in the ceramic molded body. Furthermore, the proposed polycarborane and the like have a disadvantage that they cannot be added in large amounts because of their high melting properties.

[Means for Solving the Problem] In view of the current state of the prior art as described above, the present inventors have developed a method that uses a preceramic polymer as a binder that does not require a degreasing step, and has developed a method that increases the amount of residual carbon and increases the pyrolysis yield. It has high temperature strength, excellent corrosion resistance and oxidation resistance,
The present invention was completed as a result of intensive research based on the idea that it would be possible to obtain a ceramic molded body with excellent machinability.

That is, according to the present invention, firstly, the main repeating unit is represented by -(SiH2Nl+-)-, and is about 100 to
A ceramic molded body is provided, which is obtained by firing a ceramic molded body containing a binder made of polysilazane having a molecular weight within the range of 50,000 to convert the binder into a ceramic and integrating the binder.

Second, the main repeating unit -(SiH2N11)-
The number average molecular weight is 200 to 500,000, and the ratio of 31 groups in one molecule to
i I+ 2 groups/S i It 3%) is 2.5
~8.4, and the element ratio is Si:50% by weight
-70% by weight, N: 20% - 34% by weight, N: 20% - 34% by weight, former 5% - 9% by weight, obtained by firing a ceramic molded body containing a binder made of polysilazane, converting the binder into a ceramic, and integrating it. A ceramic molded body characterized by the following is provided.

Third, the main repeating unit is ((SiHz)-(N0
sweat and -(-(sillz) ro-) (in these formulas,
n, m and r are each 1, 2 or 3. ) and having a molecular weight in the range of about 500 to 50,000, a ceramic molded body containing a binder made of polysiloxane is fired to form the binder into a ceramic,
A ceramic molded body characterized in that it is obtained in an integrated manner is provided.

Fourth, the composition formula (R3il-INH)X((R3iH)
l sN) I-x (wherein R is independently an alkyl group, alkenyl group, cycloalkyl group, aryl group, or a group other than these groups in which the atom directly connected to 81 is carbon, an alkylsilyl group , represents an alkylamino group, an alkoxy group, and Q, 4 < x < 1).

It is characterized by being obtained by firing a ceramic molded body containing a binder made of polyorganohydrosilazane having a molecular weight within the range of about 200' to 100.000, converting the binder into a ceramic, and integrating the binder. A ceramic molded body is provided.

Fifth, the main repeating unit is 15iR111NIlz
- (in the formula, RI) R2 is each independently selected from a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aru-4-lamino group, an aryl group, and an alkylsilyl group); (N11')-i
- (in the formula, n is 1 or 2), the atomic ratio of nitrogen and spherical atoms bonded to the gay element atoms (
A ceramic molded body containing a binder made of a modified polysilazane high polymer having a number average molecular weight of about 200 to 500,000 and a N/Si) of at least 0.80 is fired to form the binder into a ceramic and then integrated. A ceramic molded body is provided.

Sixthly, a ceramic molded body containing a binder made of polymetallosilazane, which is a reaction product of polysilazane and metal acetate, is fired to form the binder into a ceramic, which is then integrated into 14B. A ceramic molded body is provided.

Similarly, according to the present invention, a method for manufacturing each of the above ceramic molded bodies is provided.

That is, first, the repeating unit of soil is (S i I
I. A ceramic molded body containing a binder made of polysilazane represented by N11) and having a molecular weight within the range of about 100 to 50,000 is fired to convert the binder into a ceramic, thereby obtaining an integrated ceramic molded body. A method for manufacturing a ceramic molded body is provided.

Second, the main repeating unit is (Sit12NIl+-
It is expressed as
llz group/5ilh group) is 2.5 to 8.4, and the element ratio is Si: 50% to 70% by weight, N: 2
A ceramic molded body containing a binder made of polysilazane having a content of 0% to 34% by weight and H: 5% to 9% by weight is fired to convert the binder into a ceramic, thereby obtaining an integrated ceramic molded body. A method for manufacturing a ceramic molded body is provided.

Third, the main repeating unit is -(-(sioz)n(
No) = 3- and -H5i II z) rOu- (in these formulas, n, m, r are each 1.2 or 3), and is within the range of about 500 to 50,000. Provided is a method for producing a ceramic molded body, which comprises firing a ceramic molded body containing a binder made of 100% oxide having a molecular weight of 100% to form a ceramic, thereby obtaining an integrated ceramic molded body.

Fourth, the compositional formula (R5i11NII)X((R5ill
)1. sN) +- (wherein R is independently an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or 6;1 a group in which the atom directly connected to 31 other than these groups is carbon, an alkyl Silyl W1 represents an alkylamino group, alco;1-cy group, and °ζ0.4 < x <
).

A ceramic molded body containing a binder made of polyorganopidrosilarin represented by Sefumi whose 'IM sign is to get a body.

A method for manufacturing a cookie cutter is provided.

Fifth, the main repeating unit is ~SiR+HNRz-(
In the formula, R1 and R2 are each independently selected from a hydrogen atom, an alkyl group, an alkenyl group, an cycloalkyl group, an alkylamino group, an aryl group, and an alkylsilyl fin. wherein n is 1 or 2), the atomic ratio of nitrogen bonded to silicon atoms and silicon (N/Si) is at least 0.80, and the number average molecular weight is about 200 to 500.0
A method for producing a ceramic molded body is provided, which comprises firing a ceramic molded body containing a binder made of a modified polysilazane high polymer No. 00 to convert the binder into a ceramic to obtain an integrated ceramic molded body.

Sixthly, a ceramic molded body containing a binder made of polymetalonolazane, which is a reaction product of polysilazane and metal alkoxy 1', is fired to convert the binder into a ceramic, thereby obtaining an integrated ceramic molded body. A method for manufacturing a ceramic inx molded body is provided.

2. The polysilazane (hereinafter referred to as inorganic polysilazane) whose main repeating unit is represented by (SillzNll) used in the binder in the first invention is 100 to
It has a number average molecular weight of 50,000 and is composed of a cyclic inorganic polysilazane, a linear inorganic polysilazane, or a mixture thereof. The inorganic polysilazane preferably used in the present invention has a number average molecular weight of 300 to 200.
It is preferably a 1jli-like inorganic polysilazane having a molecular weight of 600 to 1,400.

The inorganic borisilaline shown above can be synthesized by the method shown below.

■ Inventor patent application (patent application 6O-145903)-5
ilhCffi2+2Py -> 5il12Cp, 2
・2Py adduct・S+1hCff 2 ・2P
y adduct +3Nl13-→-i5ilhNl
l). l-2NllaC1, -+-2Py■ D, 5e
yferLh et al. ([lSP 4,397,828)■
W, M, 5canLlin et al., lnorg, ch.
em, 1972. 11 Such inorganic polysilazane can be obtained as an oil-like substance or a powder depending on the degree of polymerization. And in any case,
Easily soluble in solvents such as xylene. Therefore, by adding various ceramic powders and inorganic polysilazane to such a solvent and mixing them, it is possible to easily distribute them uniformly as a binder in the ceramic powder. Here, since the inorganic polysilazane also acts as a deflating agent (dispersing agent), the present slurry becomes a homogeneous slurry suitable for granulation or slurry molding. Therefore, as a molding method, a press molding method such as a mold press method or a rubber press method, or a slurry molding method such as an extrusion method, a sheet method, or a casting method can be applied.

When the molded body obtained as described above is sintered, the inorganic polysilazane is thermally decomposed, hydrogen is volatilized, highly active Sl and N react with the ceramic particles, and act as a sintering binder. Strongly bonds between particles. This differs in wood quality from the case of sintering using conventional 5iJ4 ceramic powder.

In the case of 5i3Nn powder, the bond between Si and N is strong,
It is difficult to sinter. Therefore, in order to sinter 5i3Na, sintering aids such as 1lj2203 and MgO are added.

On the other hand, from the preceramic polymer used in the present invention, Si and N are generated in the form of radicals at relatively low temperatures, that is, in a very highly active state, and form strong bonds with ceramic particles (and reinforcing fibers if present). form a bond. Furthermore, when a preceramic polymer is turned into a ceramic, there are cases in which it basically does not react with the ceramic raw material, and cases in which it reacts with the ceramic raw material, but when it does react, of course, the reactivity is also high due to the above-mentioned high activity. If it does not react with the ceramic raw material, the ceramic polymer used in the present invention basically becomes Si3N4, or this Si:+N+ is 13
It is produced at about 00 to 1500°C and is amorphous or microcrystalline. Therefore, it is a ceramic molded sintered body with relatively low density but excellent mechanical properties. In addition, even when crystallized by higher temperature heat treatment (calcination), the crystallization occurs through the above-mentioned highly active and amorphous state, so the conventional 5i
Made into ceramics using a different mechanism than Ja sintering,
A ceramic molded sintered body that is denser and has better mechanical properties can be obtained. Furthermore, when reacting with ceramic raw materials, a ceramic molded sintered body that is denser and has better mechanical properties can be obtained for the same reason.

That is, the structure of the ceramic molded sintered body of the present invention is different from the structure of the sintered body obtained by conventional sintering of ceramics (S is Na ). When a preceramic polymer becomes ceramic and becomes amorphous or microcrystalline, it is clearly different from conventional crystalline materials, but even when preceramic polymers crystallize, they are not as sintered as conventional methods. The structure differs from that of the conventional sintered body in that it does not require a structure in which the grain boundaries of the 5iJa crystal grains are bonded by a grain boundary phase caused by a reaction with a sintering aid. Also in the present invention, A P 203 or the like can be added as ceramic particles, and in such a case, Az20. Is there a possibility that a phase similar to the reaction product of 5IJa and 5IJa is generated?Due to the difference in the mechanism of formation, differences remain in the internal structure of the obtained sintered body.

Naturally, there are cases where the silicon nitride ceramic particles produced by the thermal decomposition of polysilazane react with any ceramic. It is easy to mix homogeneously, and the reaction occurs actively due to the presence of highly active silicon, nitrogen, or amorphous silicon nitride produced by thermal decomposition, so it can be used at lower temperatures than using commercially available silicon nitride powder. It has the advantage that it can be densified or a strong sintered body can be produced. A typical example of this case is when an oxide such as AP-203 or SiO□ is used as the arbitrary ceramic.
When polysilazane is used, a reaction to form a compound containing silicon and nitrogen with sialon, silicon oxynitride, etc. occurs actively, resulting in accelerated sintering and a strong sintered body.

As mentioned above, as a typical example of a case where amorphous or microcrystalline silicon nitride ceramic particles generated by thermal decomposition of polysilazane firmly bond and fill any ceramic particles, that is, they do not react, This is a case where non-oxide ceramics such as silicon nitride and silicon carbide to which no sintering aids such as oxides are added are used. However, the presence or absence of a reaction depends on the sintering temperature and time, the type of ceramic and the mixing ratio, etc., so in the end, A, amorphous or microcrystalline silicon nitride ceramic particles produced by thermal decomposition of polysilazane, B , a compound containing silicon and nitrogen (not limited to one type) produced by the reaction between silicon nitride ceramic particles produced by thermal decomposition of polysilazane and any ceramic, and at least one of the following two types of structures: It becomes a ceramic molded body.

Even in the structure when reacting in this way, a more homogeneous structure can be obtained when compared with the conventional structure under the same chemical composition conditions. That is, abnormal grain growth does not occur. Therefore, it has the effect of improving mechanical properties.

In addition, by heat treatment, Bureceramics polymer can be made into Si,
When generating N and making it into ceramics, the bonding force is
The higher the thermal decomposition yield of preceramic polymer, the more
Furthermore, since it is strong enough to use pre-ceramink polymer that does not leave excess carbon that is not involved in bonding, it does not have organic groups in the wood, and after thermal decomposition, it produces high-purity 5L.
Inorganic polysilazane having a Na composition can be said to be a preceramic polymer suitable as a binder for sintering. The amount of residual carbon after thermal decomposition is preferably 30wt% or less, more preferably 15wL% or less, and even more preferably 5iyt% or less, but according to the polysilazane used in the present invention, such a carbon amount is of course Furthermore, it is possible to substantially leave no carbon content. Also, this 5
The form of IJN4 is usually in the form of amorphous or very small crystal grains of 3000 Å or less, 1000 Å or less, which fill the space between ceramic particles, and therefore also serves as a grain growth inhibitor.

Note that the breceramic polymer is active in Sl.

The reaction that generates N and turns into ceramic/7x is approximately 400°
It starts at 1500°C and ends at about 1500°C.

Further, the amount of the inorganic polysilazane added can be increased or decreased without any restriction depending on the properties of the intended sintered body, such as strength, density, workability, etc.

This is because, unlike conventional preceramic polymers, by controlling the degree of polymerization, the degree of melting can be reduced and softening of the molded body can be prevented even when a large amount is added.

Therefore, according to the present invention, the substantial portion is made of ceramic particles, and the binder that binds them together (i.e., the portion in which the ceramic polymer is made into ceramic)
There are various types of systems, ranging from systems in which a very small amount of binder is present to form a bond between ceramic particles, to systems in which the binder is essentially made into a ceramic, forming a matrix in which ceramic particles are dispersed. can exist. Moreover, as mentioned above, the organization of these systems is unique.

Similarly, metal or ceramic whiskers, short fibers, or continuous fibers may be included together with or in place of ceramic particles.

The inorganic polysilazane used in the present invention is a polysilazane that does not have an organic group in the side chain in a woody manner, and has a molecular weight (degree of polymerization) of
is about 100~50. ,000 (approximately 2 to 1 ooo). Such inorganic polysilazane can be produced, for example, by reacting dihalosilane with a base to produce a dihalosilane adduct, and then reacting this adduct with ammonia (JP-A-60-1/15903). (see official bulletin).

If the molecular weight of the inorganic polysilazane used in the present invention is less than 100, it will evaporate together with the solvent, reducing its effectiveness as a binder, while if it is more than 50,000, it will be insoluble in the solvent, resulting in uneven mixing and a decrease in ceramic strength.

In order to mold ceramics using such a binder, it is necessary to add ceramic powder and inorganic polysilazane to a solvent and mix them to form a slurry, or to evaporate the solvent from this slurry. Granulated powder may be prepared by press molding.

For example, in order to apply the press method, the solvent in the slurry may be evaporated using a spray dryer to form granulated powder. At this time, the inorganic polysilazane acts as a molding binder for granulation and at the same time is uniformly mixed into the ceramic powder as a sintering binder (sintering aid). By press-molding the granulated powder obtained in this way, a molded article having a predetermined shape can be obtained. Also, according to the slurry molding method,
A molded body in which binder for molding and sintering is uniformly mixed can be obtained directly without using granulated powder.

In addition, in the present invention, the ceramic molded body (sintered body) is immersed in a solution in which inorganic polysilazane is dissolved in a solvent, and the ceramic molded body in which the molded body (sintered body) is impregnated with the inorganic polysilazane is fired. Therefore, it is also possible to densify a ceramic molded body (sintered body).

Examples of solvents include hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons, halogenated hydrocarbons such as halogenated methane, halogenated ethane, and halogenated Hensen, aliphatic ethers, and alicyclic ethers. Ethers such as can be used. The preferred solvent is methylene chloride,
: Jroporum, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride, halogenated hydrocarbons such as trichloroethane, tetrachloroethane, ethyl ether, isopropyl ether, ethyl butyl ether, butyl ether, 1,2-dioquinethane, dioxane, dimethyldioxane, tetrahydrofuran , ethers such as tetrahydropyran, pentane: 1-nan, isohexane, methylpenkune, hebutane, iso\pukun, octane, isooctane, cyclopenkune, methylcyclopenkune, cyclohexane, methylcyclohexane, hensen, toluene, xylene, ethylhensen, etc. hydrocarbons, etc.

The obtained ceramic molded body is fired to turn the inorganic polysilazane into a ceramic, thereby obtaining a ceramic molded sintered body. The firing conditions include heating and sintering in a temperature range of 600 to 2300° C. in a vacuum, in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas.

The sintered body thus obtained is an amorphous body formed by thermal decomposition of polysilazane between the ceramic particles or whiskers used, or a sintered body with a diameter of 3000 Å or less or 1000 Å.
The structure is filled with the following extremely fine particles.

Thus, according to the present invention, by selecting polysilazane as the preceramic polymer and selecting polysilazane having no organic group in the side chain, ceramic forming and sintering with excellent mechanical and chemical properties can be achieved by firing at a low temperature. You get a body.

Instead of or together with the above inorganic polysilazane, the main repeating unit is represented by (S i II□Nll-), the number average molecular weight is about 200 to 500,000, and
The ratio of 5iHz group to SiH2 group in the molecule (S i H2 group/Si++, group) is 2.5 to 8.4, and the element ratio is Si: 50% to 70% by weight, N: 20% by weight % to 34% by weight, I]: 5% to 9% by weight. The same effect as the invention can be obtained (second invention).

Such an inorganic polysilazane high polymer is produced by heating an inorganic polysilazane in a basic solvent or a solvent containing a basic compound (Japanese Patent Application No. 6.3-7/1)
(See specification No. 918).

The starting inorganic polysilazane may be the inorganic polysilazane used in the first invention.

The inorganic silazane, which is the starting material, is heated in a basic solvent or a solvent to which a basic compound has been added to cause a dehydrogenation polycondensation reaction (hereinafter also simply referred to as a polycondensation reaction). in this case,
As the basic compound, compounds containing basic elements such as nitrogen and phosphorus, such as tertiary amines, secondary amines having a sterically hindered group, and phosphine can be used. The reaction solvent used is a solvent prepared by adding such a basic compound to a non-basic solvent, or a solvent consisting of the basic compound itself. When adding a basic compound to a non-basic solvent, the amount of the basic compound added is at least 5 parts by weight, preferably 20 parts by weight or more, per 100 parts by weight of the non-basic solvent. If the amount of the basic compound added is less than this, the polycondensation reaction will not be smoothly promoted.

In the polycondensation reaction, a solvent solution containing an inorganic polysilazane high polymer, that is, a high molecular weight inorganic polysilazane, is obtained, but in this case, the solution composition is adjusted to reduce the basic compound or basic solvent content. , 30% by weight in total solvent
The content is preferably 5% by weight or less.

The polycondensation reaction of inorganic polysilazane is considered to include the following elementary reactions.

(1) In the above general 2N), + 1 2-5i-N-→-3i-N-+II□II
11 HIf If -3i-N -IH This inorganic polysilazane high polymer is a polymer obtained by polycondensation reaction of the raw material inorganic polysilazane to the above-mentioned 1), and new crosslinks are created in the inorganic polysilazane molecule. It has a high molecular weight due to bonding. That is, since this inorganic polysilazane high polymer is formed by crosslinking and polymerizing inorganic polysilazane having a number average molecular weight of 100 to 50,000 as a raw material as described above, its molecular weight is naturally However, the molecular weight is greater than that of the raw material inorganic polysilazane. −
On the membrane surface, the inorganic polysilazane high polymer has a number average molecular weight of 200 to 500,000, preferably 1,500 to 500,000.
It has 10.000.

Inorganic polysilazane polymers have the above-mentioned characteristics in terms of molecular structure, which distinguishes them from the raw material inorganic polysilazane, but one of their other characteristics is that they have many branched structures. be. Due to this branched structure, the inorganic polysilazane high polymer has a higher molecular weight than the raw material inorganic polysilazane, but rather provides improved solvent solubility. For example, 5eyfer
The inorganic silazane previously proposed by th et al.
It is an oily liquid with a proton ratio of f/N-It of about 3.3, but it can be heated at about 200 °C or 3-5 at room temperature.
It solidified when left in the sun. On the other hand, this inorganic polysilazane high polymer has a molecular weight of 200 to 500
,000, and S i II 3 in one molecule
The number of groups is usually twice or more greater than that of the raw material inorganic polysilazane, and it has solvent resolubility. The reason why the inorganic polysilazane high polymer has a more branched structure than the raw material inorganic polysilazane is due to the polycondensation reaction.
For example, this is thought to be due to the following reactions occurring.

□ 1I II H 1II 1 ++ 11 11 H The branched structure of this inorganic polysilazane high polymer can be obtained by, for example, "HNMR spectrum measurement (SiH2
)/(SiJ) ((Silla): 1/2 of the area of 5i-H resonance at δ4.8, (Silla)
:173] ratio of the 5i-H resonance area at δ4.4. In the case of raw material inorganic polysilazane, the (Sillz) / (Si11:+) ratio is 5
．． The range is from 0 to 19.0, but in the case of inorganic polysilazane high polymers, the values are lowered from 2.5 to 8.4, respectively. S i ++ 2 of inorganic polysilazane high polymer
/S i H3 ratio is not within the above range, pathogenic,
The excipient properties are poor and the intended purpose cannot be achieved.

Inorganic polysilazane polymers have the above-mentioned molecular structural characteristics, and in terms of physical properties, they are soluble in organic solvents while having cross-linked bonds, and are particularly solids obtained by removing the solvent from a solution. Polymers exhibit a major characteristic of being re-soluble in solvents. Conventional inorganic polysilazane has poor stability, and when the solvent is removed from its solution, it produces a resinous solid, which is insoluble in the solvent.
Inorganic polysilazane polymers do not exhibit this tendency. Therefore, while conventional inorganic polysilazane is impossible or extremely difficult to handle as a solid polymer, inorganic polysilazane high polymers can be easily handled as a solid polymer.

Furthermore, the inorganic polysilazane high polymer has an elemental ratio of Si:59.
Weight% to 70% by weight, N: 20% to 34% by weight, 1
(=5% to 9% by weight).

Preferred elemental ratio of the inorganic polysilazane high polymer; (Si
: 61% to 68% by weight, N: 25% to 33% by weight
t < weight%, 1]: 5% to 8% by weight, and more preferable element ratios are Si: 644% to 6% by weight, N: 2
77% to 3% by weight, I]; 5% to 7% by weight.

If the element ratio of the inorganic polysilazane high polymer does not satisfy the above range, it will be difficult to easily handle it as a solid polymer, and the intended purpose will not be achieved.

As mentioned above, polysilarin-based preceramic polymers are excellent as binders for producing ceramic molded bodies (sintered bodies), but depending on the type of ceramic and the type of reinforcing material composited with the ceramic, silicon and nitrogen It may be desirable for the binder to contain other elements such as oxygen, carbon, metal elements, etc. For example, it is desirable that the binder for oxide, carbide, oxynitride, and carbonitride-based ceramics contains oxygen and carbon. Furthermore, in a ceramic sintered body reinforced with metal fibers, it is possible to improve the adhesion with the metal fibers by including a metal element in the binder. In addition, certain metals are considered to be effective as sintering aids. From this point of view, we investigated binders for producing ceramic molded bodies (sintered bodies) and found that polysiloxane, which is based on polysilazane without organic groups, has oxygen introduced into it, and polyorganohydro, which has carbon introduced therein. Silazane and metal-incorporated polymetallosilazane each have their own unique usefulness, and ceramic molded bodies (sintered bodies) manufactured using these binders have uniquely excellent mechanical and chemical properties. I discovered something. In this way, the third to sixth inventions were completed. In these binders, the smaller the amount of organic groups each polymer has, the higher the ceramic yield and the advantage of providing a denser structure.

In the binder made of these polymers, the method for producing the ceramic molded body and the method for firing are the same as those described for the binder made of the inorganic polysilazane.

The borish[Ikizazan used in the present invention is, for example, a dihalosilane or an adduct of a dihalosilane and a Lewis base,
It can be produced by reacting ammonia with water or oxygen (see JP-A-62-195024).

The polyorgano-1-rosilazane used in the present invention can be produced, for example, by reacting a complex of organohydrosilane and a Lewis base with dry ammonia (JP-A-61-89230, U.S. Pat. ,659
, No. 850).

The modified polysilazane polymer used in the present invention has the general formula -
5iR, HNI12 (wherein R1 and Rz are each independently selected from a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkylamino group, an aryl group, and an alkylsilyl group), It can be produced by dehydrogenation polycondensation reaction of polysilazane with a number average molecular weight of 100 to so, ooo and ammonia or hydrazine under basic conditions (Japanese Patent Application No. 63-74
(See specification No. 919).

By increasing the molar ratio of N to Si, this modified polysilazane high polymer has a N/Si ratio of Si
Since it is close to that of 3N4, it is more ideal as a breatheramic polymer.

The raw material polysilazane used to produce the modified polysilazane high polymer has a skeleton represented by the general formula -5iR+11NR2-.

In the above formula, R1 and R2 represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkylamino group, an aryl group, or an alkylsilyl group.

The raw material polysilazane has a number average molecular weight of 100 to 50,000 and is composed of cyclic polysilazane, chain polysilazane, or a mixture thereof. The raw material polysilazane preferably used in the present invention is a chain polysilazane having a number average molecular weight of 300 to 2,000, preferably 600 to 1,400.

In addition to the above-mentioned inorganic polysilazane, such polysilazane can be produced by the following method.

■ B, J, AyJetl (USP 3,318.82
3)・5itlzCj2 z+MezNH-)lIzs
i (NMez) 2 + Me2Ntl ・IICl
.

−HzSi (NMez) 2 +MeNIIz −+
−(11zSiNMc)−i +Me2NII −+
-1h■ D, 5eyferth et al. (USP 4..1
82,669) ■ Inventor patent application (JKAI 61-89)
230)・MeSiHCffiz +2Py □ M
eSiHCffiz·2Py adducL Polysilazane, which is a starting material, is subjected to a dehydrogenation polycondensation reaction (hereinafter also simply referred to as polycondensation reaction) with ammonia or hydrazine under basic conditions. In this case, basic conditions mean that a basic compound such as tertiary amines, secondary amines having a sterically hindered group, phosphine, etc. are allowed to coexist in the reaction system. Such basic conditions can be created by adding a basic compound to the reaction solvent, and
It can be formed by using a basic solvent or a mixture of a basic solvent and a non-basic solvent as the reaction solvent. The amount of the basic compound added is at least 5 parts by weight, preferably 20 parts by weight or more, per 100 parts by weight of the reaction solvent. If the amount of basic compound added is less than this,
Polycondensation reaction is not promoted smoothly.

The polycondensation reaction is preferably carried out in a solvent as described above, but in this case, the concentration of the raw material polysilazane in the solvent is 0.
．． It is 1 to 50% by weight, preferably 1 to 12% by weight.

If the concentration of polysilazane is lower than this, the intermolecular polycondensation reaction will not proceed sufficiently, and if it is higher than this, the intermolecular polycondensation reaction will proceed too much and a gel will be produced. The reaction temperature is
The temperature is -78 to 300°C, preferably -40 to 180°C; at lower temperatures, the polycondensation reaction does not proceed sufficiently, and at higher concentrations, the polycondensation reaction proceeds too much and forms a gel.

Further, the amount of ammonia or hydrazine used as a polycondensation reactant is in the range of 0.01 to 5.0, preferably 39) or 0.5 to 3.0, as a molar ratio to 1 mole (average mole) of polysilazane. If it is lower than that, the polycondensation reaction will not proceed sufficiently, and if it is higher than that, the polycondensation reaction will proceed too much and a gel will be produced. As the reaction atmosphere, air can be used, but preferably a basic atmosphere consisting of ammonia, hydrazine or other amines, an inert gas atmosphere such as dry nitrogen or dry alcon, or a mixed atmosphere thereof is used. be done.

The polycondensation reaction between polysilazane and ammonia or hydrazine is considered to include the following elementary reactions.

(1) In JFIJ-Sailor (1), ■n1. R
If both of 2 are organic groups, 5i-N- R, 11° (2) In the above - Saito (1), if one of R1, 17, is a hydrogen atom and the other is an organic group, (i) R + If R2 is hydrogen, then 1; 2 (N-11), 1 5i-N- Formerly (ii) If R2 is hydrogen, R, l ( □ 5i-N- R,H (3) Said -Sailor (+) When both R1 and R2 are hydrogen atoms, "Modified polysilazane high polymer is a polymer produced by polycondensation reaction of raw material polysilazane and ammonia or hylacine as described above, and polysilazane molecules A new cross-linking bond (Nll)n (n = 1 or 2) is introduced into the polymer to increase the molecular weight.Modified polysilazane high polymer has a higher molecular weight than the raw material polysilazane.
In terms of molecular structure, the following points are 1) characteristics.

(1) The proportion of nitrogen atoms bonded to silicon atoms increases.

As mentioned above, the modified polysilazane polymer newly contains -(NHh (n=1 or 2)) as a crosslinking group, and the proportion of nitrogen atoms based on this crosslinking group increases. In the case of raw material polysilazane, the ratio of nitrogen atoms bonded to silicon atoms to silicon atoms (N/Si) is, for example, 0.60 to 0.75 for inorganic polysilazane, 0.90 to 0.97 for methylhydrosilazane, 0.67-1.50 for N-methylsilazane, 0.55-0.70 for N-(triethylsilyl)allylsilazane and N-(
1.1~ for dimethylamino)cyclohexylsilazane
2.0, 0.85 to 0.96 for phenylpolysilazane
However, in the case of a modified polysilazane high polymer, its N/Si ratio is in the range of 0.80 or more and 0.80 or more, respectively.
They are 98 or more, 1.6 or more, 0.87 or more, 2.2 or more, and 0.98 or more, and are enhanced. The ratio of nitrogen atoms bonded to silicon atoms and silicon atoms (N/Si
) is defined within a range in which gelation of the modified polylazan high polymer does not occur, in other words, within a range that shows solvent solubility, but is usually 2.5 or less, preferably 2.0 or less. be.

(2) The number average molecular weight range is 200 to 500.000. The modified polysilazane high polymer is made of polysilazane having a number average molecular weight of N100 to 50,000 as described above.
This is used as F and is formed by cross-linking polymerization through -(NHh bonds, so its molecular weight is naturally greater than the molecular weight of the raw material polysilazane. -On the membrane surface. The target modified polysilazane high polymer has a number average molecular weight of 200 to 50.
0,000, preferably 1,500 to 10,000.

Modified polysilazine polymers have the above-mentioned characteristics in terms of molecular structure, which distinguishes them from the raw material polysilazane, but one of their other characteristics is that they have many branched structures. be. Due to this branched structure, the modified porinlasane high polymer has a higher molecular weight than the raw material polysilazane, but has improved solvent solubility. The inorganic silazane proposed by Oyforth et al. is an oily liquid with an S 1-If/N-II propene ratio of about 3.3, and about 200
It is heated at 0.degree. C., but it is more assimilated every 3 to 50 minutes at room temperature. On the other hand, modified polysilazane polymers have a molecular weight of 200 to 500,000 and have (N)l-)- as a crosslinking group.

(n-1 or 2), the ratio of nitrogen atoms to silicon atoms (N/Si) is 0.8 or more, and the number of S i It z groups in one molecule is usually It has solvent re-solubility.

The branched structure of the modified polysilazane high polymer is, for example,
'HN) Obtained by IR spectrum measurement (SiL
)/(SiHz) ((Sill.); Area of Si-H resonance at δ4.8 XI/2, (Sith)
: area of Si-H resonance at δ4.4×1/3] ratio. In the case of raw material polysilazane, the (S i Il.)/(SiHz) ratio is 5.0 to 8.2.5 in the powder method and 8.5 to 13 in the eyferth method.
．． 0 and S stock method, the range is 14.0 to 19.0, and the number of S itl x in one molecule is 3 to 10, 0 to 1, and 0 to 1, respectively. When the invention is modified, (Silh/5iH3
), the values are reduced to 2.5 to 4.8, 4.5 to 7.0, and 5.5 to 10.0, respectively, and furthermore, the number of 5iHa in one molecule is doubled.

The modified polysilazane polymer has the above-mentioned structural characteristics such as molecule -A, and physical properties include crosslinking -
(Nll)-n (n = l or 2),
In many cases, the solid polymer is soluble in organic solvents, and in particular, the solid polymer obtained by removing the solvent from the modified polysilazane high polymer solution exhibits a significant characteristic of being re-soluble in the solvent. Conventional polysilazane has poor stability, and when the solvent is removed from its solution, it produces a resinous solid that is insoluble in solvents, but modified polysilazane polymers do not exhibit this tendency. . Therefore, while conventional polysilazane is impossible or extremely difficult to handle as a solid polymer, the modified polysilazane high polymer can be easily handled as a solid polymer.

The polymetallosilazane used in the present invention can be produced, for example, by reacting polysilazane with a metal alkoxide. The present inventors have previously disclosed a method for producing polytitanosilazane and polyaluminosilazane by reacting polysilazane with titanium alkoxide and aluminum alkoxide (Japanese Patent Application Nos. 61-223790 and 1986).
1-226270), and in subsequent research it was discovered that polyzirconosilazane and other polymetallosilazanes can generally be produced by a similar method.

According to this method, -i formula (■): lnI □ → -5i-N+ (1)1] R2173 (R', R2, R3 are each independently a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group) group, aryl group, or a group other than these groups in which the group directly bonded to silicon is carbon, an alkylsilyl group, an alkylamino group, or an alkoxy group.However, at least one of R', R2, and R3 is a hydrogen atom. ) and a polysilazane having a main skeleton consisting of units represented by -Funenin (■): M (OR'). (II) (wherein, M
is a metal capable of forming a metal alkoxide, and R4 is a metal that can form a metal alkoxide;
May be the same or different, hydrogen atom, carbon atom number 1
represents an alkyl group or aryl group having ~20 atoms, at least one R4 is the above alkyl group or aryl group; n is the valence of M; Polymetallosilazane is produced by reacting metal alkoxides represented by ).

This polymetallosillarin is produced by the reaction between hydrogen atoms bonded to at least some of the silicon atoms and/or hydrogen atoms bonded to nitrogen atoms in the entire skeleton of polysilazane, and the metal alkoxide. Side chain group or cyclic atom fused with metal alkoxide,
This compound is characterized by having a crosslinked structure.

In the reaction between the Si-H bond of polysilazane and the metal alkoxide, the organic group (R4) of the metal alkoxy F (M(OR'), ) pulls out the hydrogen atom of the Si-H bond and replaces R'H. By desorption, a Si-0-M bond is formed.

In the reaction with oxide, the hydrogen atom of the N-H bond is extracted by the metal alkoxide, and the following N-0-M bond or N-M bond (hereinafter referred to as N-Y-M bond) is formed. Ru.

Si Nll+M(OR'), -+Si
N-OM(OR')fi-+1 1
l 1 metal alkoxide has a maximum of n
Depending on the type of starting metal alkoxide or the reaction conditions, the resulting polymetallosilazanes can be polymers with 1 to n functionality with respect to the metal. ■The functional polymer is S in the main chain of polysilazane.
It has a structure in which a pendant group is introduced into i and/or N.

R' tl R1 ]11 □ M(OR'), l-+ M(OR')11-
In the +2 to (n-1) functional polymer, a 'ζ cyclic, crosslinked structure is formed in the polysilazane skeleton via the M atom. The cyclic structure includes a structure in which two functional groups in one molecule of metal alkoxide are condensed with adjacent gay atoms and nitrogen atoms of polysilazane. A crosslinked structure occurs when two or more functional groups of a metal alkoxide are condensed with two or more molecules of polysilazane.

R'HR' -5i-N--5i N- 0II Y l1 M(011'), -21(OR'), l-2OR'
Y 13i-N--5i -N-13i-N--5i N-00Y l \/ M(OR') ゎ-2, M(OR'), l-2Y I
I ] 1 N-3i- Also, some trifunctional or higher functional polymers have the above-mentioned cyclic structure and crosslinked structure at the same time. Usually, the polymer represented by (III) or (IV) is obtained by reacting polysilazane with a metal alkoxide.

As described above, the structural change from polysilazane to polymetallosilazane is that a new pendant group or cyclic or crosslinked structure is formed based on the skeleton of polysilazane.

According to the present invention, the metal M is a metal capable of producing a metal alkoxide, and is at least one selected from the group of metals of Groups 1 to 8 of the Periodic Table of the Elements, which achieves the object of the present invention. Preferred metals for
It is at least one selected from the group of metals of Group A and Groups 3 to 8. Particularly preferred metals are titanium, aluminum, zirconium and the like.

The number average molecular weight of the polymetallosilazane used in the present invention is 2
It is within the range of 000,000 to 500,000.

The method for producing polymetallosilazane used in the present invention is as follows:
The process consists of reacting vorisillarin and metal alkoxyl in a JJIE7 medium or solvent and under an atmosphere inert to the reaction.

The polysilazane to be used may be any polysilazane having at least 5i-H bonds or jN-bonds in the molecule, and polysilazane alone, copolymers of vorisilaryne and other polymers, and polysilazane may be used. It can also be used in mixtures with other compounds.

The polysilazane used includes those having a chain, cyclic, or crosslinked structure, or those having a plurality of these structures simultaneously in the molecule, and these can be used alone or in a mixture.

Typical examples of polysilazane to be used include the following, but are not limited to these.

In the general formula (1), a compound having hydrogen atoms in R', R2, and R3 is perhydropolysilazane, and its production method is described, for example, in JP-A-60-145903, D, 5ey
Communication of Am, ferth et al.
Cer, Soc, , C-13, , January
1983. has been reported. What is obtained by these methods is a mixture of polymers having various structures, but basically contains a chain part and a cyclic part in the molecule, and -(SiH2NHh (SillzNh (SiH3)
, (a + b + c = 1). An example of the structure of perhydropolysilazane is shown below.

1] The method for producing polysilazane having a hydrogen atom in R1 and R2 and a methyl group in R3 in general formula (1) is D, 5eyfer
th et al. Polym, Prepr, Am, Chem
,Soc,, Div.

Polym, Chem, 35.10 (1984). The polysilazane obtained by this method has repeating units! 5iHzNCII3)-, a chain polymer and a cyclic polymer, neither of which has a crosslinked structure.

- A method for producing polyorgano(hydro)silazane having hydrogen atoms in R1 and R3 and an organic group in R2 in Noshiro (1),
D, 5eyferth et al. Polym, Prepr.
Am.

Chem, Soc, Div, Polym, Chem,
, 25.10 (1984), and JP-A-61-89230. Polysilazane obtained by these methods mainly has a cyclic structure with -(R2SillNII)- as a repeating unit and a degree of polymerization of 3 to 5, (R2Si11NII)X((I12SiH)1.r,
N) Some molecules have a chain structure and a cyclic structure at the same time, which can be represented by the chemical formula 1-X (0,4<x<1).

In general formula (1), R1 has a hydrogen atom, R2 and R3 have an organic group, and R1 and R2 have an organic group, R
3 has a hydrogen atom, beR'R25iNR3)
It has a cyclic structure mainly having a degree of polymerization of 3 to 5 as a repeating unit.

Next, among the polysilazane used, representative examples of polysilazane other than -Noshiro (1) will be given.

Among polyorgano(hydro)silazane, D, 5e
Communication of Am
,Cer,Soc,,C-132,July 19
84. Some have a cross-linked structure within the molecule, as reported by. - Examples are as follows.

In addition, polysilazane (R'
A polysilazane having the following structure obtained by co-ammonia decomposition of S+ (Nil)

R2HR' It The polysilazane used in hot weather has a main skeleton consisting of units represented by the general formula (1) as described above, but the unit represented by -Funenin (I) is cyclized as is clear from the following. In that case, the cyclic portion becomes the terminal group, and if such cyclization is not performed, the terminal of the main skeleton must be a group similar to R', R2, R'' or hydrogen. can.

There is no particular restriction on the molecular weight of the polysilazane to be used, and any available one can be used. However, in terms of reactivity with metal alkoxide, R', R2, and R in formula (1)
3) It-f is preferably a group with little steric hindrance. That is, R'
, R2 and R' are hydrogen atoms and 01-. An alkyl group of is preferred, and a hydrogen atom and a C1-2 alkyl group are more preferred.

There are no particular restrictions on the metal alkoxide used, but from the viewpoint of reactivity, R' in formula (+) is preferably a C1-2o alkyl group, more preferably a C1-,0 alkyl group,
7 to 4 alkyl groups are most preferred.

The mixing ratio of polysilazane and metal alkoxide is M/
It is added so that the Si atomic ratio is from 0.001 to 60, preferably from 0.01 to 5, and more preferably from 0.05 to 2.5. If the amount of metal alkoxide added is greater than this, the metal alkoxide will be recovered unreacted, and if it is less, no significant increase in molecular weight will occur.

(11) polysiloxazane, (11) polyorganohydrosilazane, and (11) polysiloxazane used as a binder in the present invention;
iii) The degree of polymerization (molecule N) of polymetallosilazane is
(i) 5 to 500 (approximately 500 to 50,000
), preferably 10 to 100 (approximately 1,000 to 10
．． 000), (ii) 4-1700 (approximately 200-1.
00,000), preferably 10-200 (about 500-
20,000), (city) molecular weight of about 200~soo,
ooo, preferably within the range of 1000 to 10,000. If their degree of polymerization or molecular weight is smaller than the above range, they will evaporate together with the solvent, reducing their effectiveness as a binder, while if larger than the above range, they will be insoluble in the solvent, resulting in non-uniform mixing. Ceramic strength decreases.

In addition, as mentioned above, the present polysilazane binder can be applied to any ceramic material such as carbon fiber, graphite fiber, silicon carbide fiber, Si-Ti CO thread fiber, alumina fiber, silica fiber, silicon nitride fiber, or tungsten fiber. It is also useful as a binder for producing fiber-reinforced ceramic molded bodies reinforced or supplemented with continuous metal fibers, whiskers, or short fibers. As a molding method, a known slurry method or press method can be applied. For example, examples include the tram winding method, in which various types of ceramic continuous fibers are impregnated into the aforementioned mixed slurry of polysilazane, ceramic powder, and solvent, and prepreg sheets are layered and pressure sintered by winding and drying the mixture around a drum, and ceramic fiber bundles. Slurry method, typified by cast molding method, in which the fibers are impregnated with slurry, and press, in which layers of continuous ceramic fibers arranged in one direction and layers of mixed powder of polysilazane and ceramics are alternately laminated and sintered under pressure. Basically, a fiber-reinforced ceramic molded body can be produced by utilizing the advantages of polysilazane as a binder in exactly the same manner as the above-mentioned system without using long fibers.

[Effects of the Invention] According to the present invention, by using a specific polysilazane-based preceramic polymer as a binder, it can be fired at a relatively low temperature to have high high-temperature strength, high oxidation resistance and corrosion resistance, and excellent workability. A ceramic sintered body can be obtained. In particular, a denser sintered body can be obtained by using a polysilazane-based polymer that does not substantially contain organic groups. Furthermore, by using polysilazane, polysiloxazane, polyorganohydrosilazane, and polymetallosilazane, each of the ceramic sintered bodies can have particularly excellent properties. Polysilazane is used as a binder for producing pure 5iJ4 sintered bodies, polysiloxazane is used as a binder for producing oxide-based sintered bodies such as alumina and silicon oxynitride, and polyorganohydrosilazane is used as a binder for SiC or 5iJ4-SiC composite sintered bodies. , polymetallosilazane is suitable as a binder for sintered bodies such as sialon and metal oxides, and polymetallosilazane is suitable as a binder for manufacturing metal-reinforced composite sintered bodies. ,Y,Ga,? It has the effect of substituting for a sintering aid by containing metals such as Lg, and in this case, it has the advantage that it is present in a uniformly dispersed manner, so it can be used in a smaller amount than the externally added sintering aid.

Furthermore, the ceramic sintered body of the present invention has the feature that ceramic molding can be performed without requiring two steps of degreasing.

〔Example〕

The polysilazane used in each of the following Examples was prepared as follows.

Toyokokan 11 Examples 1 to 7, 8. Inorganic polysilazane of 18 and 19 (
(powder) preparation.

Four 1" flasks with an internal volume of 10p, gas blower tubes,
Equipped with mechanical stirrer and dewar condenser. After purging the inside of the reactor with deoxygenated dry nitrogen, 4.91 g of degassed dry pyridine was placed in a four-bottle flask.
This was chilled on ice. Next, Schiff 1 no 1. When 516 g of Zsilane is added, a white solid adduct (SillzCn 2
・2C5)lsN) was generated. The reaction mixture was ice-cooled, and while stirring, 510 g of purified ammonia was blown into the reaction mixture through a sodium hydroxide tube and an activated carbon tube.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry pyridine, and then filtered under a nitrogen atmosphere to obtain filtrate 8.5 j2. When the solvent was distilled off from the filtrate under reduced pressure, 173 g of resin solid inorganic polysilazane was obtained.

The number average molecular weight of the obtained polymer was 980 as measured by GPC.

The above resin solid inorganic polysilazane was ground in a mortar and used as a binder.

1 Consideration ±1 Preparation of inorganic polysilazane (oil form) used in Example 8.17.

Inner volume 1! A four-round flask was equipped with a gas injection tube, mechanical stirrer, and dewar condenser. After purging the inside of the reactor with deoxygenated dry nitrogen, 500 mR of degassed dry dichloromethane was placed in a four-bottle flask and cooled with water. Next, 48.6 g of dichlorosilane was added. This solution was cooled on ice and hydroxylated with stirring.I-I
Ammonia 42 purified through Jum tube and activated carbon tube
．． 5 g was blown in as a mixed gas with nitrogen. During the reaction, pine cones were generated in the gas flow path, so the gas flow path was occasionally tapped to prevent clogging.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry pyridine, filtered under a nitrogen atmosphere, and the solvent was distilled off from the filtrate under reduced pressure to obtain 9.6 g of viscous oily inorganic polysilazane. . The number average molecular weight of the obtained polymer was 640 as measured by GPC.

Work hard↓ Preparation of polysiloxazane used in Example 10.

A gas blowing tube is placed in a fourth flask with an internal volume of 300 mR.
Equipped with mechanical stirrer and dewar condenser. 150 mfi of dry pyridine was placed in a fourth flask and cooled on ice. Next, 15.8 g of dichlorosilane
(0,156mo 42 ) was added for about 1 hour to form a white solid Adakl□ (Sil12C1z ・2
CSIl, N) was produced. This reaction mixture was cooled on ice,
While stirring, add 15.7 g of ammonia (0,92
mo f2 ), water 0.33 g (0,018 mo
e) was mixed with nitrogen gas and blown in for about 1.5 hours. After the reaction was completed, the reaction mixture was centrifuged under a nitrogen atmosphere, the residue was washed with dry methylene chloride, and the washing liquid and centrifuged liquid were combined and filtered under a nitrogen atmosphere.

The filtrate contains 2.01% polysiloxazane as shown below.
(g/mfl)%.

Take 150 ml of the filtrate and distill off the solvent under reduced pressure to give a solution of 3.01 ml.
g of white polysiloxane powder was obtained. The number average molecular weight of the obtained powder was determined by GPC to be 78.
It was 5.

8 of the polyorganohydrosilazane used in Reference Example 11
Made by Zhou.

The inside of the reaction system was purged with nitrogen gas using a device equipped with a four-eye flask having an internal volume of 200 ml and equipped with a gas blowing tube, a mechanical starch, a dewar condenser, and a dropping funnel. The apparatus was cooled in a water bath and
t, i Shill7 (CH3SillCffz) 6.01g
(52,2 mmop,) and dry dichloromethane 7
0 ml was added. Then pass through the dropping funnel 16. [iJE (210 mmo 12 ) was added dropwise to form a complex, resulting in a colorless solution. Thereafter, while stirring the solution, 4.10 g (240 mmop) of dry ammonia was blown into the solution along with nitrogen scum to effect the analkaline decomposition. The reaction 'G?' by the addition of ammonia? &.

became a white slurry. After the reaction was completed, the reaction mixture was centrifuged and then filtered. The filtrate and the filtrate were removed under reduced pressure to obtain 2.80 g of polymethyl(1:1)silazane as a colorless viscous oil. When this viscous oil was measured using the vapor pressure drop method, the average molecular weight was 1.77 x 103,
It was found that the average degree of polymerization was 30.

Preparation of polyaluminosilazane used in Example 12 A four-liter flask with an internal volume of 11 was equipped with a gas inlet tube, a mechanical starch, and a dewar condenser.

After the interior of the reactor was replaced with deoxygenated dry nitrogen, degassed dry pyridine 490 was placed in a fourth flask and cooled on ice. Next, when 51.6 g of dichlorosilane is added, a white solid adduct (Sil12Cj22 ・2C
5HJ) was produced. The reaction mixture was ice-cooled, and while stirring, 51.0 g of purified ammonia was blown into the reaction mixture through a sodium hydroxide tube and an activated carbon tube.

After the reaction is completed, the reaction mixture is centrifuged, washed with dry pyridine, and then filtered under nitrogen atmosphere to obtain filtrate 8.
50mR was obtained. When the solvent was distilled off under reduced pressure from 5 mfl of the filtrate, 0.102 g of resinous solid inorganic polysilazane was obtained.

The number average molecular weight of the obtained polymer was determined to be 1120 by the freezing point depression method (solvent: dry Hensen).

A four-loop flask with an internal volume of 200 mR was equipped with a condenser, a serum cap, and a magnetic cooler. After purging the inside of the reactor with dry argon (65), 1.50 g (7.34 mm) of aluminum triisopropoxide was placed in a fourth flask.
Hensen's solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane 40.72 g/f
f) 83 geese were added with stirring using a syringe to form a mixed solution. A reflux reaction was carried out while stirring this solution at 80° C. for 2 hours under an argon atmosphere.

The reaction solution changed from colorless to pale yellow.

The number average molecular weight of the produced polymer was determined to be 1710 by the freezing point depression method (solvent: dry Hensen).

After the reflux reaction was completed, the solvent was distilled off under reduced pressure to obtain polyaluminosilazane as a pale yellow resinous solid.

The resinous solid polyaluminosilazane was ground in a mortar and used as a binder.

Preparation of the inorganic polysilazane polymer used in Examples 13 and 14.

This tube blows gas into a four-eyed flask with an internal volume of 500 m1,
Mechanical star sea and dewar condenser were installed. After purging the inside of the reactor with deoxygenated dry nitrogen, 280mj of degassed dry pyridine was placed in a four-bottle flask! and cooled it on ice. Next, when 51.6 g of dichlorosilane was added, a white solid adduct (SiH2cL 2
CsHsN) was generated. The reaction mixture was ice-cooled, and while stirring, 30.0 g of purified ammonia was blown into the reaction mixture through a sodium hydroxide tube and an activated carbon tube.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry pyridine, and further filtered under a nitrogen atmosphere to obtain filtrate 520. The solvent was distilled off from 5 mβ of the filtrate under reduced pressure to obtain 0.98 g of resinous solid inorganic silazane.

The number average molecular weight of the obtained polymer was 1020 as measured by GPC.

100 mN of the pyridine solution of the above inorganic silazane (concentration of inorganic silazane, 5.24% by weight) was placed in a pressure-resistant reaction vessel with an internal volume of 300 m1, and heated at 150°C in a closed system with a nitrogen atmosphere for 3 hours.
The reaction was carried out with stirring for hours. During this time, a large amount of gas was generated. The pressure before and after the reaction is 1.0 kg/cf+
”- rose. After cooling to room temperature, dry ethyl Hensen 200
Add geese, pressure 3-5 mmtlg, temperature 50-70°
When the solvent was removed at C. 4.68 g of white powder was obtained. This powder was soluble in toluene, tetrabitrofuran, chlorine 1 vol and other aqueous solvents.

The average molecular weight of the polymer powder was 2470 as measured by GPC.

Preparation of the modified polysilazane polymer used in Examples 15 and 16.

A fourth flask with an internal volume of 11 was equipped with a gas blowing tube, a mechanical stirrer, and a dewar condenser. After replacing the inside of the reactor with deoxygenated dry nitrogen, 490% of degassed dry pyridine was placed in a four-neck flask and cooled on ice. Next, 51.6 g of Schiff 111:1 silane was added to form a white solid adduct (Si11zCffi2
・2C1,I+,,N) was generated. The reaction mixture was ice-cooled, and while stirring, 51.0 g of purified ammonia was blown into the reaction mixture through a sodium hydroxide tube and an activated carbon tube.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry pyridine, and further filtered under a nitrogen atmosphere to obtain filtrate 850. The solvent was distilled off from 5 ml of the filtrate under reduced pressure to obtain 0.102 g of a resin solid inorganic.

The number average molecular weight of the obtained polymer was 980 as measured by GPC.

Pyridine solution of the above inorganic polysilazane a (concentration of perhydropolysilazane, 5.04% by weight) 100mffi
was placed in a pressure-resistant reaction vessel with an internal volume of 300 mN, 2.8 g (0,165 mof) of purified anhydrous ammonia was added, and the reaction was carried out in a closed system at 100°C with stirring for 3 hours. During this time, a large amount of gas was generated. The pressure increased by 1.2 kg/c+f before and after the reaction. After cooling to room temperature,
Add 200 mff1 of dry 0-xylene and apply pressure 3 to 5.
When the solvent was removed at mmHg and a temperature of 50 to 70°C,
5.22 g of white powder was obtained. This powder was compatible with toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of the polymer powder was 3810 as measured by GPC.

A. Actual JL example of use of inorganic polysilazane - 7 for 90% by weight of 5iJa powder of 200 mesh or less
．． Element ratio after firing at 1200°C in N2 is N/5i
=1.25. ○/5i=0.05, C/5i=0.
06"-Si and N so that the inorganic polysilazane is 10% by weight.

The powder and an ortho-xylene solution of inorganic polysilazane were mixed, dried, and then lightly crushed in a mortar and sized using a mesh 100 sieve. 1500kg/(:l) of this mixed powder
Pressure molded with a molding pressure of 10mm x 50n+m
A 5mMl powder compact was obtained. This powder compact is
2, heating and sintering was carried out at a heating rate of 200°C/hr to 1200°C. As a result, the bulk density was 2.60g/c+fl
, a 5iJ4 sintered body with a bending strength of 13.5 kg/mm'' was obtained.

Mix the SiC powder and a n-hexane solution of inorganic polysilazane so that the inorganic polysilazane is 10% by weight with respect to 90% by weight of SiC powder of 200 mesh or less,
After drying, heat to 600° in N2 at a heating rate of 100°C/hr.
The mixture was preheated at C and ground. A normal hexane solution was added, mixed, dried, and pulverized so that the inorganic polysilazane was 5% by weight based on 95% by weight of this powder. This mixed powder was pressure-molded at a molding pressure of 2000 kg/cffl to obtain a powder compact of 10 mm x 50 mm x 5 cores. This powder compact was heated and sintered in argon at a heating rate of 100°C/hr to 1400°C. As a result, the bulk density was 2.66 g/c+] the bending strength was 12.4 kg/mm2
A SiC sintered body was obtained.

Actual Leakage 1 7% by weight of powdered inorganic polysilazane and 93% by weight of α-AN 203 powder of 200 mesosinus or less were mixed together with an appropriate amount of Hensen, dried, and pulverized. This mixed powder was pressure-molded at a molding pressure of 3000 kg/c+i to 10+n
A powder compact of m x 50 mm x 5 mm was obtained. This powder compact was heated and sintered in N2 at a heating rate of 200'C/hr to 1000°C. As a result, the bulk density was 3.12 g/cIfl.

An A ff 20:l sintered body with a bending strength of 7.5 kg/mm 2 was obtained.

After mixing and drying 15% by weight of powdered inorganic polysilazane and 85% by weight of Si3N4 powder of 200 mesh or less with an appropriate amount of ortho-xylene, the mixture was heated to 600°C at a heating rate of 100°C/hr in N2. It was preheated and ground.

95% by weight of this powder and 5% by weight of powdered inorganic polysilazane were mixed together with an ortho-xylene solution, and the mixture had a viscosity of about 20%.
It was made into a slurry of 0 cps. This slurry was dried with a spray dryer to form a granulated powder with an average particle size of 80μ, and placed in a carbon die for 1 hour at 1750°C under a N2 stream.
Hot pressed for an hour. As a result, the bulk density was 3.02g.
/C1fl, Si3 with bending strength 27.3kg/+nm2
An N4 sintered body was obtained.

50% by weight of an inorganic polysilazane in the form of an oil-like inorganic polysilazane and 50% by weight of SJ4 powder of 200 mesh or less were mixed to form a clay-like slurry. The slurry was extruded and
The material was heated and sintered to 1500°C at a heating rate of 0°C/hr. As a result, a Si3N4 sintered body having a bulk density of 2.67 g/cnJ and a bending strength of 15.8 kg/mm'' was obtained.

Actual Picture I 50% by weight of an inorganic polysilazane in the form of a cloudy powder and 50% by weight of S+ 3N4 powder of 200 mesh or less were mixed in ortho-xylene to form a slurry with a viscosity of about 400 cps.

Pour this slurry into a ceramic mold, dry it, and then
2, heating and sintering was carried out at a heating rate of 100°C/hr to 1500°C. This results in a bulk density of 2.63 g/c
+fl and a 5iJ4 sintered body having a bending strength of 15.0 kg/mm2 was obtained.

5i3Na sintered body obtained in the same manner as in Example 1 was immersed in a xylene solution of inorganic polysilazane having a concentration of 50 wt%, and the obtained impregnated molded body was dried and then heated at 200° in N2.
It was heated and sintered to 1400°C at a heating rate of C/hr.

As a result of performing this series of impregnation, drying, and heating sintering twice, the bulk density was 2.83 g/cl, and the bending strength was 22.2 kg.
/ mm2 5iJ4 sintered body was obtained.

Real difference flower i (use of whiskers) 40% by weight of commercially available 5iJ4 whisker and 60% by weight of oily inorganic polysilazane were mixed to form a clay-like slurry. This slurry was extruded at 100°C in N2.
It was heated and sintered to 1500°C at a heating rate of 1/1. As a result, the bulk density was 2°6og/c+fl and the bending strength was 25.
7kg/mm”, fracture toughness value 8.5 kg/mm
A highly tough Si3N4 sintered body was obtained.

Example 1 ~ (Used in combination with conventional sintering binder) 30% by weight of powdered inorganic polysilazane, SiJ of 325 mesh or less, + 60% by weight of powder, 0.3μ of α-I! ,
5% by weight of 203 powder and 5% by weight of 1μ Y2O3 powder were mixed with ortho-xylene to form a slurry with a viscosity of about 200 cps. This slurry was dried with a spray dryer to form granulated powder with an average particle size of 100μ, and 2000kg
10m+nX50 by pressure molding with a molding pressure of /cra
A powder compact of mm x 5 mm was obtained. This compact was heated and sintered in N2 at a heating rate of 200°C/hr to 1500"C. As a result, the bulk density was 2.87 g/hr.
A Si3N4 sintered body with a c+R1 bending strength of 33 and 2 kg/mm2 was obtained.

Kitamoto 1D - Using a commercially available wax binder without using inorganic polysilazane, granulated powder with an average particle size of 100 μm was prepared in the same manner as in Example 9. Mixing ratio: 5iJa powder 90, 120
3 powder 5, Y2O3 powder 5% by weight), 2000kg/
A molded article having the same shape was obtained under a molding pressure of c+fl. This molded body was subjected to long-term degreasing treatment (400°C at 10°C/hr).
°C) and then sintered under the same conditions as in Example 9, but the bulk density of the Si3N4 sintered body obtained was 1.
92 g/c+fl, and the bending strength was 9-8 kg/mm''.

B. Use of polysiloxazane 1203 was prepared in exactly the same manner as in Example 3, except that polysiloxazane was used instead of inorganic polysilazane.
A sintered body was obtained. The bulk density of this sintered body is 3.50g/c
f, the bending strength was 12.5 kg/mm 2 , and a sintered body with higher density and higher strength than in Example 3 was obtained.

C. Uses of polyorganohydrosilazane” 1 Masuzuki.

A SiC sintered body was obtained in exactly the same manner as in Example 2, except that polyorganohydrosilazane was used instead of inorganic polysilazane. The bulk density of this sintered body is 2.7
8 g/C+fi, and the bending strength was 16.5 kg/mmt, which was twice the result of Example 2.

D. Equimole of Si3N4 powder (average particle size 1μ) for use of polymetallosilazane, A! 203
Powder (average particle size: 033μ), hemp powder (average particle size: 0.
5μ) Polyaluminosilazane is 1% for the total 90%
Si, N4. 8N20z, A/
, N, and polyaluminosilazane powder were mixed together with an appropriate amount of ortho-xylene, dried, and then lightly crushed in a mortar and sized using a mesh 100 sieve. 20% of this mixed powder
Pressure molded at 00kg/crR, 10mm x 5
A powder compact of 0 mm x 5 mm was obtained. This molded body is
When heated to 1550°C at a heating rate of 200°C/hr in No. 2, a Sialon sintered body having a bulk density of 2.90 g/mm' and a bending strength of 35.8 kg/mm2 was obtained.

Northern Comparison t2- A sialon sintered body was produced in exactly the same manner as in Example 12 except that polyaluminosilazane was not used, but the bulk density was 2.2 g/cl, which was lower than that in Example 12. It turned.

D. Use of inorganic polysilazane high polymer.5.
An iJ4 sintered body was obtained. The bulk density of this sintered body is 2.75g
/c++L bending strength was 18.2 kg/mm2, and compared to Example 1, a sintered body with higher density and higher strength was obtained.

S was produced in exactly the same manner as in Example 2, except that an inorganic polysilazane high polymer was used instead of the inorganic polysilazane.
An iC sintered body was obtained. The bulk density of this sintered body is 2.75g/
cJ and bending strength were 16.4 kg/mm2, which exceeded the results of Example 2.

E. Use of modified polysilazane high polymer.
A Ja sintered body was obtained. The bulk density of this sintered body is 2.87g/
c/, and the bending strength was 24.3 kg/cffl, which exceeded the results of Examples 1 and 13.

S was prepared in exactly the same manner as in Example 1, except that a modified polysilazane high polymer was used instead of the inorganic polysilazane.
An iC sintered body was obtained. The bulk density of this sintered body is 2.83g/
The crR1 bending strength was 21.9 kg/mm2, which exceeded the results of Examples 2 and 14.

F. Use of continuous fiber ■ A slurry prepared by mixing α-Al 203 powder with an average particle size of 0.2 mm, oily inorganic polysilazane, and ortho-xylene in a weight ratio of 3 = 1:1. , diameter 20m
Cast in mφ Teflon container and heated at 80°C1 in nitrogen.
It was held for 24 hours to cure. Next, this compact was sintered under atmospheric pressure at 1600°C for 1 hour in nitrogen at a temperature increase rate of 3°C/min. The bulk density of the obtained sintered body was 3.43
g/c/. Further, when this sintered body was crushed and an attempt was made to identify the crystal phase by powder X-ray diffraction, it was found that there was a composite sintered body consisting of corundum and β-xialon. That is, it can be seen that since the amorphous silicon nitride produced by thermal decomposition of vorisilazane is highly active, it reacts with Zheζα-AN203 and is converted into β-4'' iron.

In place of this inorganic polysilazane, average particle size of 0.28 mm
A sintered body was produced in exactly the same manner as in Example 17 except for using α-5iJ4 powder, and the bulk density was 2.
, 78 g/(:+fl).The sintered body was crushed and the crystal phase was identified by powder X-ray diffraction. That is, this sintering condition (1600'CX 1
It is presumed that because the α-8He 203 powder and the α-5IJa powder did not react sufficiently at the time of 15 hours), the sintering effect due to the reaction was poor and densification did not proceed.

The weight ratio of powdered inorganic polysilazane and ortho-xylene to SiO□ powder with an average particle diameter of 5μIll is 1.28:
■: The slurry mixed at the ratio of 1 was desolventized in nitrogen at 80°C.
It was calcined in nitrogen for 1 hour at 800°C. This calcined product was ground in a mortar manufactured by Holon Karhai 1, and the ground powder was molded into a mold with a diameter of 20 mm at a pressure of 200 kgf/cM. Next, this molded body was placed in nitrogen at 5° (':/m
Atmospheric pressure sintering was carried out at 1600'CX for 1 hour at the same speed as in. The bulk density of the obtained sintered body was 2.54 g/a
It was R. Furthermore, when this sintered body was crushed and an attempt was made to identify the crystal phase by powder X-ray diffraction, it was found that it was a composite sintered body consisting of cristobalite Si3N4 and Si2N20.

Comparison side 1 A sintered body was produced in exactly the same manner as in Example 18 except that α-SiJN powder with an average particle size of 0.2 μm was used instead of inorganic polysilazane, and the bulk density was 2.
, 13 g/c+ (i).The sintered body was crushed (↓'/) and the crystal phase was identified by powder X-ray diffraction, and it was found to be cristobalite. Therefore, this sintered strip ('l(IGO
Since there was almost no reaction between the 5102 powder and the α-SiJN powder at 0°C for 1 hour, it is presumed that no sintering action occurred due to the reaction and densification did not proceed.

40 g of β-SiO powder with an average particle size of 03 μmo and 80 g of an ortho-xylene solution of inorganic polysilazane (50% inorganic polysilazane) were mixed well to prepare a homogeneous slurry. The slurry was impregnated with 3000 filaments of carbon fiber and wound around a flat mandrel at 80° in nitrogen.
After drying and curing, cut into 70mm x 70
mm x 0. A prepreg sheet 1- of 8 mm was obtained.

Next, seven of these prepreg sheets were laminated and heated in a hot press at 1,600°C for 1 hour at 500 kgf.
The composite was sintered under a pressure of /cry and subjected to machining (cutting, grinding) to obtain a carbon fiber reinforced ceramic composite with a size of 3I plate x 4 mm x 38 mm. The fiber content of this composite is 45% by volume, the high temperature bending strength at 1400°C is 65kgf/mm2, and the fracture toughness value at room temperature is 1O. 2k
gf/mm3'', and a fiber-reinforced ceramic composite sintered body characterized by high strength at high temperatures and high fracture toughness was obtained.

In addition, when this sintered body was crushed and an attempt was made to identify the crystal phase by powder X-ray diffraction, it was found that the matrix was β-SiC
It is clear that it consists of microcrystalline α-Si3Nn, and by this α-S+H1N4 (the size of the crystallite, 1x diagonal 111 fold) (Hani 111 method (JONl!S method),
It was estimated that there were 2,800 people.

Claims (14)

[Claims] 1. Obtained by firing a ceramic molded body containing a binder made of polysilazane whose main repeating unit is represented by ■SiH_2NH■ and having a molecular weight within the range of about 100 to 50,000, converting the binder into a ceramic, and integrating it. A ceramic molded body characterized by: 2. The main repeating unit is represented by ■SiH_2NH■, the number average molecular weight is about 200 to 500,000, and 1
The ratio of SiH_3 groups to SiH_2 groups in the molecule (SiH_2
group/SiH_3 group) is 2.5 to 8.4, and the element ratios are Si: 50 weight % to 70 weight %, N: 20 weight % to 34 weight %, H: 5 weight % to 9 weight %. 1. A ceramic molded body, characterized in that it is obtained by firing a ceramic molded body containing a binder made of polysilazane to form the binder into a ceramic and integrating the binder. 3. The main repeating unit is ■SiH_2)_n(NH)
___m■ and ■SiH_2)_rO■ (in these formulas, n,
m and r are 1, 2 or 3, respectively. ), characterized in that it is obtained by firing a ceramic molded body containing a binder made of polysiloxane having a molecular weight within the range of about 500 to 50,000, converting the binder into a ceramic, and integrating the binder. Molded object. 4. Composition formula (RSiHNH)_x [(RSiH)_1_
．． _5N]_1_-_x (wherein R is independently an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the atom directly connected to Si is carbon, an alkylsilyl group, a polyorganohydrosilazane having a molecular weight in the range of about 200 to 100,000. 1. A ceramic molded body, characterized in that it is obtained by firing the body, turning the binder into a ceramic, and integrating the binder into a ceramic. 5. The main repeating unit is -SiR_1HNR_2-(
In the formula, R_1 and R_2 are each independently selected from a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkylamino group, an aryl group, and an alkylsilyl group. In the formula, n is 1
or 2), the atomic ratio of nitrogen bonded to silicon atoms to silicon (N/Si) is at least 0.80, and the number average molecular weight is about 200 to 500.
1. A ceramic molded body, characterized in that it is obtained by firing a ceramic molded body containing a binder made of a modified polysilazane high polymer of 0.000 to convert the binder into a ceramic, and integrating the binder into a ceramic body. 6. 1. A ceramic molded article, characterized in that it is obtained by firing a ceramic molded article containing a binder made of polymetallosilazane, which is a reaction product of polysilazane and a metal alkoxide, to turn the binder into a ceramic and integrating the binder. 7. The ceramic molded article according to any one of claims 1 to 6, which is reinforced with metal fibers or ceramic fibers. 8. The ceramic molded article according to claim 7, wherein the fibers are long fibers or woven fabrics thereof. 9. A ceramic molded body is produced by firing a ceramic molded body containing a binder made of polysilazane whose main repeating unit is represented by ■SiH_2NH■ and having a molecular weight within the range of about 100 to 50,000, and converting the binder into a ceramic. A method for producing a ceramic molded body, characterized in that it obtains a ceramic molded body. 10. The main repeating unit is represented by ■SiH_2NH■, and the number average molecular weight is about 200 to 500,000,
Ratio of SiH_3 groups to SiH_2 groups in one molecule (SiH_
2 groups/SiH_3 groups) is 2.5 to 8.4, and the element ratio is Si: 50 weight % to 70 weight %, N: 20
It is characterized by firing a ceramic molded body containing a binder made of polysilazane with a H content of 5% to 34% by weight and H: 5% to 9% by weight to convert the binder into a ceramic to obtain an integrated ceramic molded body. A method for manufacturing a ceramic molded body. 11. The main repeating unit is ■SiH_2)_n(NH
)_m■ and ■SiH_2)_rO■ (in these formulas, n
, m, r are 1, 2 or 3, respectively. ), the ceramic molded body containing a binder made of polysiloxane having a molecular weight within the range of about 500 to 50,000 is fired, the binder is turned into a ceramic, and an integrated ceramic molded body is obtained. A method for manufacturing a ceramic molded body. 12. Composition formula (RSiHNH)_x [(RSiH)_1
＿． _5N]_1_-_x (wherein R is independently an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the atom directly connected to Si is carbon, an alkylsilyl group, It represents an alkylamino group or an alkoxy group, and 0.4<x<1.)
A ceramic molded body containing a binder made of polyorganohydrosilazane represented by A method for producing a characteristic ceramic molded body. 13. The main repeating unit is -SiR_1HNR_2-
(In the formula, R_1 and R_2 are each independently a hydrogen atom,
a main skeleton represented by an alkyl group, an alkenyl group, a cycloalkyl group, an alkylamino group, an aryl group, and an alkylsilyl group), and a main skeleton represented by ■NH■_n (in the formula, n is 1 or 2). having a crosslinking bond, the atomic ratio of nitrogen bonded to silicon atoms to silicon (N/Si) is at least 0.80, and the number average molecular weight is about 200 to 50
1. A method for producing a ceramic molded body, which comprises firing a ceramic molded body containing a binder made of a modified polysilazane high polymer having a molecular weight of 0,000 to convert the binder into a ceramic to obtain an integrated ceramic molded body. 14. Production of a ceramic molded body, characterized in that a ceramic molded body containing a binder made of polymetallosilazane, which is a reaction product of polysilazane and a metal alkoxide, is fired to convert the binder into a ceramic to obtain an integrated ceramic molded body. Method.