JPH0331326A - Random copolymer silazane and production thereof - Google Patents

Abstract

PURPOSE:To obtain a random copolymer silazane, having a specific straight- chain structure and excellent in high-temperature strength, etc., by reacting respective specific inorganic dihalosilane with organo(hydro)dihalosilane with a Lewis base and reacting the resultant complex mixture with ammonia. CONSTITUTION:A random copolymer silazane, obtained by reacting an inorganic dihalosilane expressed by formula I (X is halogen) (preferably dichlorosilane) and an organo(hydro)dihalosilane expressed by formula II (R is alkyl, alkenyl, etc.) with a Lewis base (preferably pyridine, etc.) and reacting the resultant complex mixture with ammonia, linearly and randomly having units expressed by formulas III and IV with 100-50000, preferably 1000-50000 number-average molecular weight and suitable as a high-performance material for space aircraft industries, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a random copolymerized silazane and a method for producing the same.

Silicon nitride and silicon nitride-containing ceramics using polysilazane as a precursor have excellent high-temperature strength, thermal shock resistance, and oxidation resistance, so they are used as high-temperature materials or as high-performance materials in the aerospace industry and automobiles. It can be expected to have a wide range of applications in industry.

[Conventional technology]

Silicon nitride sintered bodies have excellent high-temperature strength, thermal shock resistance, and oxidation resistance, so they can be used as high-temperature structural materials for gas turbines, diesel engines, etc., or as cutting tools, making a significant contribution to energy and resource conservation. It is important as one of the possible high-performance materials.

Conventionally, methods for producing silicon nitride include: heating metal silicon powder at 1300°C to 150°C in a nitrogen or ammonia stream;
Silicon direct nitriding method, in which the silicon is directly nitrided by heating at 0°C; ■ Silica reduction method, in which silica or a silica-containing substance is heated together with carbon in a nitrogen atmosphere, the silica is reduced with urea, and the produced silicon reacts with nitrogen. , ■ Gas phase synthesis method in which silicon tetrachloride and ammonia are directly reacted at high temperature, ■ Imide thermal decomposition method in which silicon diimide obtained by ammonolysis of silicon tetrachloride is heated in a non-oxidizing atmosphere to obtain silicon nitride, etc. has been adopted.

However, in the case of method (2) above, the reaction time is long, the heating process is complicated, and the silicon nitride obtained is mainly β-type silicon nitride that is coarse and contains many impurities. In the case of method (2), not only is it difficult to purify the raw materials, but the reaction time is long, and the resulting product is a mixed system of α-type silicon nitride and β-type silicon nitride. is generally amorphous, and method (2) has the advantage of being able to produce high-purity α-type silicon nitride at a lower yield.
Since Nll)z)- is not soluble in solvents, it has the disadvantage that its uses are essentially limited.

Furthermore, a method has recently been proposed in which silicon nitride is synthesized by heating polysilazane obtained by thermally decomposing organic polysilazane at 800 to 2000°C (Qi Bi!, Journal of the Japan Institute of Textile Technology, Vol. 38 N (L 1). Pages 65-?2 (19B
2 years]), but this method had the drawback that silicon carbide and free carbon were produced at the same time as silicon nitride.

On the other hand, inorganic polysilazane that is soluble in solvents is
5tock (Ber, 54. (1921), p7
40) and others, and in 1983, 5e
yferth (CowIl, 8m.

Ceraa+, Soc, C-13/14. (83)
) and others have proven that it is useful as a silicon nitride precursor. The present inventors focused on this point of view and proposed a method for obtaining highly pure α-type silicon nitride by heat-treating inorganic polysilazane (Japanese Unexamined Patent Application Publication No. 59-1989-1).
No. 207812).

[Problem to be solved by the invention]

However, in conventional inorganic polysilazane production methods, highly volatile dichlorosilane is used as a raw material, so the polysilazane formed sticks to the gas piping or the reactor wall of the reactor, resulting in gas flow - In order to prevent the above-mentioned adverse effects, it is necessary to maintain the reaction temperature at a low temperature to prevent dichlorosilane from scattering. - Dichlorosilane is highly toxic and flammable, so do not store it in a closed container at low temperatures. There were disadvantages such as complicated handling, such as having to be placed in a container. Furthermore, in the case of 5tock, etc., the synthesized polysilazane is only an oligomer of n=7 to 8 having the structure (SiHzNH)--, and is a viscous liquid at room temperature, and in the case of 5eyferth, etc. It has a more complex structure than tack etc., and 5i-
It is an oily liquid with a proton ratio of 11/N-H of about 3.3, but it solidifies by heating at about 200'C or leaving it at room temperature for 3 to 5 days. Even in the case of sintered silicon nitride, it could not be said that it had sufficient properties as a precursor for a silicon nitride sintered body shaped at room temperature.

In order to solve this problem, the present inventors first prepared an inorganic or organic polyester having a silicon-hydrogen bond, R,,R or -N- (where R and R' are organo groups, and n is 1 or 2) is suitable as a silicon nitride precursor incorporating
We proposed a polysilazane with a high molecular weight (patent application 1986).
-28295, 63-28296, 63-74
No. 919). However, the silicon nitride sintered body obtained by firing the polysilazane at a high temperature has an insufficient range of selection in terms of electrical properties and far-infrared effects.

Therefore, the present invention provides silicon nitride that can control the carbon content in a silicon nitride sintered body obtained after high-temperature firing over a wider range, that is, can be selected over a wider range in terms of electrical properties and far-infrared effects. The object of the present invention is to provide a polysilazane suitable as a precursor.

[Means to solve the problem]

According to the invention, in order to achieve the above object - up to 5
reacting a complex compound obtained by reacting an inorganic dihalosilane represented by illzXz (wherein X is a halogen atom) and an organo(hydro)dihalosilane represented by the general formula R51(H)Xz with a Lewis base with ammonia. A copolymerized silazane synthesized by general formula R51 (II
) A method for producing a copolymerized silazane is also provided, which comprises reacting a complex compound obtained by reacting an organo(hydro)dihalosilane represented by Xz with a Lewis base and reacting with ammonia.

The copolymerized silazane provided by the present invention is 5ill
Jz (referred to as inorganic halosilane) and R51(II)Xz
(referred to as organic halosilane) as a starting material, reacted with a Lewis base to form a complex, and then reacted with ammonia to synthesize 5iHJz and [wherein R is an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group]. group, alkylamino group, aralkyl group or alkylsilyl group. ] includes a linear structure randomly having units represented by
Copolymerized silazane within the range of oooo is provided.

Similarly, according to the invention. It is a copolymer in which units represented by inorganic dihalosilane represented by the general formula 5iHzXz (wherein X is a halogen atom) are randomly bonded,
Therefore, the linear structure of the copolymer itself is characterized by having the above two units randomly.

The structure of a polymer synthesized by using an inorganic halosilane or an organic halosilane as a starting material, reacting it with a Lewis base to obtain a complex, and then reacting it with ammonia is as shown in the following formula (3). be.

[However, in the above formulas (1) and (2), n, m, n', m' can include a linear part and a ring part, and generally a linear part may have a branch, but it has a structure in which cyclic portions are bonded to both ends. Although not intended to be limiting, in the overall structure in which the linear portion and the annular portion are combined or branched in various ways as in the above formulas (1) and (2), the linear portion, The annular portion is configured to additionally include a component represented by the following formula (4). Therefore, the overall composition is (SillzNH)X(R3iHNH)y ((SiH
t)+, sN) r−x ((RSiH)+, sN)
+-y However, 0.01≦y/x≦0.99.0.4<x
<1.

The copolymerized silazane of the present invention is characterized in that these units exist randomly including in the linear structure.

The number average molecular weight of the random copolymerized silazane of the present invention is generally in the range of 100 to 50,000. A copolymer with a large molecular weight can be obtained, if necessary, by heating the copolymer once produced. Further, from the viewpoint of usefulness as a ceramic precursor, it is desirable that the molecular weight is large, and a number average molecular weight of 500 or more, particularly 1000 or more is more preferable.

Next, the method for producing the copolymerized silazane of the present invention will be explained.

General formula 5iHJt (X =
F.

Dino\rosilane represented by C1, Br, I) is handled as 1
It is selected from among halosilanes from the viewpoint of properties and reactivity, but it is particularly preferable to use dichlorosilane from the viewpoints of reactivity and raw material cost.

The organodino-10 silane used in the present invention has the following general formula: % formula % (wherein R is an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylamino group, an aralkyl group, or an alkylsilyl group) ). Among these, R usually has 1 to 1 carbon atoms.
7, preferably 1 to 5, more preferably 1 to 2 alkyl groups, 2 to 7 alkenyl groups, 5 to 7 cycloalkyl groups, and aryl groups;
Chlorine, bromine and iodine are preferably used. Aryl groups include phenyl, tolyl, xylyl, diethyl, cumenyl, benzyl, phenethyl, α
-Methylbenzyl, benzhydryl, trityl, styryl, cinnamyl, biphenyl, naphthyl, etc. can be used. As the alkylsilyl group (mono-, di-, tri-substituted), alkylamino group (mono-, di-substituted), and alkoxy group, those having 1 to 7 carbon atoms are usually used.

The base used is a Lewis base that does not react with the halosilane other than to form an adduct. Examples of such Lewis bases include tertiary amines (trialkylamines such as trimethylamine, dimethylethylamine, diethylmethylamine, and triethylamine; pyridine;
picoline, dimethylaniline and derivatives thereof), secondary amines having sterically hindered groups, phosphine, stipine, arsine and derivatives thereof (e.g. trimethylphosphine, dimethylethylphosphine, methyldiethylphosphine, triethyl phosphine,
(trimethylarsine, trimethylstipine, trimethylamine, triethylamine, etc.).

Among them, bases with low boiling points and less basicity than ammonia (
For example, pyridine, picoline, trimethylphosphine,
Dimethylethylphosphine, methyldiethylphosphine, triethylphosphine) are preferred, and pyridine and picoline are particularly preferred from the viewpoint of handling and economy.

In the present invention, 5ill□x2 and R31llXz are first reacted with a Lewis base, but 5iHzχ2 and R51HX
The mixing ratio with 2 is not particularly limited, and the molar ratio is 1:99 to 9.
The ratio may be within the range of 9:1, but this ratio is selected depending on the properties of the final ceramic. In general, it can be said that the carbon content increases, and more carbon remains after ceramic formation. Typically the ratio is 10:
90-90: 10, even 30: 70-70
: Use within the range of 30.

The amount of Lewis base relative to the total dihalosilane is preferably 0.5 or more, preferably 1.0 or more, and more preferably 1.5 or more in molar ratio.

In the present invention, a Lewis base is added to the above two types of dihalosilanes to form a complex. At this time, it is preferable to use a Lewis base alone or a mixture of a non-reactive solvent and a Lewis base as the reaction solvent. good. Non-reactive solvents include hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons, halogenated hydrocarbons such as halogenated methane, halogenated ethane, and halogenated benzene, aliphatic ethers, and aliphatic hydrocarbons. Ethers such as cyclic ethers can be used.

Preferred solvents are methylene chloride, chloroform, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride,
Halogenated hydrocarbons such as trichloroethane and tetrachloroethane, ethers such as ethyl ether, isopropyl ether, ethyl butyl ether, butyl ether, 1,2-dioxyethane, dioxane, dimethyldioxane, tetrahydrofuran, and tetrahydropyran, pentane, hexane, isohexane, methylbencune, Heptane, isohbutane, octane, isooctane, cyclobencune, methylcyclobencune, cyclohexane, methylcyclohexane, benzene, toluene, xylene,
Hydrocarbons such as ethylbenzene. Among these solvents, dichloromethane and pyridine are particularly preferred from the viewpoint of safety.

The concentration of dihalosilane in the solvent can be set arbitrarily, but it is preferably in the range of 1 to 15% by weight (hereinafter abbreviated as %). In addition, as a condition for forming a complex, the temperature is within a range where the reaction system becomes liquid (typically -20 to 80°C).
), but the temperature is preferably room temperature, and the pressure is generally from normal pressure to elevated pressure, preferably under nitrogen pressure.

Since the reaction is extremely fast, the reaction time can be set arbitrarily.

Next, the complex thus produced is reacted with dry ammonia to effect ammonolysis.

The ammonia used at this time may be either gas or liquid. Ammonia is preferably dried by, for example, passing it through solid sodium hydroxide and then passing it through metallic sodium. The amount of ammonia added is preferably 3.0 to 20 times, preferably 4 to 15 times, and more preferably 5 to 10 times the molar ratio of organo(hydro)dihalosilane. The reaction solvent, reaction temperature, reaction pressure, and time may be the same as those for complex formation. However, in a closed system, ammonia is pressurized. In addition, the amount of water in the reaction system is, for example, 50 pp.
It is desirable that it be less than m.

After the reaction is completed, the copolymerized silazane is separated using conventional means such as centrifugation.

〔Effect of the invention〕

The random copolymerized silazane of the present invention and its production method have the following advantages and are industrially useful.

(1) This copolymerized silazane is soluble in organic solvents,
Because it can be converted into silicon nitride or silicon nitride-containing ceramics by firing, it can be used to produce high-performance ceramic molded bodies, such as continuous fibers, films, and coatings that have high high-temperature mechanical strength and excellent heat resistance, corrosion resistance, oxidation resistance, and thermal shock resistance. A coating can be easily obtained. In addition, since the ceramic yield is high,
It can also be used as a binder for sintering, an impregnating agent, etc.

(2) This copolymerized silazane does not contain impurities such as residual catalysts that promote decomposition, so it has improved stability and ease of handling, and also has high purity ceramics after high-temperature firing. will improve.

(3) Since no catalyst remains in this copolymerized silazane, stability is improved and long-term storage is possible even after removal of the solvent and isolation.

(4) The method of the present invention does not use expensive and dangerous catalysts such as potassium hydride or methyl iodide, and the Lewis base used in the present invention can be reused, so it is low cost and safe. .

(5) Since this copolymerized silazane has a high molecular weight, evaporation loss during high-temperature firing is small, so the ceramic yield is improved.

(6) Since there is no contamination of impurities, the purity of ceramics after high-temperature firing is improved.

(7) By changing the proportion of dihalosilane as a raw material, any desired electrical properties from an insulator to a semiconductor can be obtained from the ceramic after forming the copolymerized silazane into an inorganic polysilazane. Further, by being able to control the amount of SiC produced in the same way, the far-infrared effect can be continuously changed.

(8) The crystallization temperature of the ceramic after high-temperature firing is high.

〔Example〕

Figure 1 shows the soil synthesis equipment. In Figure 1, l is an inorganic halosilane storage tank, 2 is an organic halosilane storage tank, 3 is a solvent storage tank, 4 is a reactor, 5 is a nitrogen gas pipe, 6 is an ammonia gas pipe, 7 is a constant temperature tank, 8 is a motor, and 9 is a A heater is connected to a thermometer 10, and 11 is an exhaust gas pipe.

The following synthetic reactions were carried out using this apparatus.

After replacing the inside of the reactor installed in a constant temperature bath with a temperature of 0 °C with dry nitrogen, add dry pyridine 900- and keep it until the temperature becomes constant. .0 g and 80.8 g of dichlorosilane (SiHzCj!□) were added to form a complex mixture to obtain a white solid adduct.

The reaction mixture was cooled to O'C and, with stirring, added 72.2% of dry ammonia. I blew g.

After the reaction was completed, dry nitrogen was blown in to remove unreacted ammonia, and the filtrate was filtered under pressure under a nitrogen atmosphere to obtain a filtrate of 850
I got 1n1. Add 1000 d of dry 0-xylene to this filtrate.
When the solvent was removed under reduced pressure, 41.0 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 790 as measured by GPC. In addition, as a result of analysis of its TR spectrum (solvent: 0-xylene), the wave number (cn+-')
Absorption based on N-H of 3350 and 1175; 21
Absorption based on 5i-H of 70; 5 of 1020-820
Absorption based on i-H and 5i-NSi; 29B0
, 2950.

It was confirmed that absorption based on C-H of 1270 was exhibited. Furthermore, 'H-NMR (proton nuclear magnetic resonance) spectrum (60M) lz of this polymer, solvent: CDCf
3/Reference material T When bone analysis of the reference material was performed, it was as shown in FIG. That is, 64.8(br, 5tu
t or 5itl), 64.4(br, 5ilh
), δ1.4 (br, NH), δ0.3 (br, 5
iCIIz) absorption was observed. From these absorption spectra, as shown in Table 1, 5iCIlz/ (Sil
ls+5ill) = 0.32.

Moreover, the elemental composition (weight %) of the polymer is Si:57.
3. N:24. O, O: 4.0, C: 6.9
It was 2.

100 million yen The reaction was carried out using the same apparatus as in Example 1.

That is, after purging the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, 900 d of dry pyridine was added and maintained until the temperature became constant, and then methyldichlorosilane (CHzSiHCj!z) was added while stirring. 57.5 g 1
50.5 g of dichlorosilane (SiHzCl g) was added to form a complex mixture to obtain a white solid adduct. The reaction mixture was cooled to 0° C. and 72 g of dry ammonia were bubbled in while stirring.

After the reaction was completed, dry nitrogen was blown in to remove unreacted ammonia, and the filtrate was filtered under pressure under a nitrogen atmosphere to obtain a filtrate of 850
I got d. Add 1000100 ml of dry 0-xylene to this filtrate.
After adding O and removing the solvent under reduced pressure, 39.2 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 630 as measured by GPC. Furthermore, when the polymer was subjected to 'H-NMR analysis in the same manner as in Example 1, as shown in Table 1, 5iC1h/(SiHz+5iH) = 1
．． 1 was read.

Further, the elemental composition (wt%) of the polymer is Si:54.
4. N: 23.8. O: 3.0, C: 12
．． It was 9.

Husband leader The reaction was carried out using the same apparatus as in Example 1.

That is, after purging the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, 900 g of dry pyridine was added and maintained until the temperature became constant, and then 92 g of methyldichlorosilane (CHsSillCl) was added while stirring. .0 g and 20.2 g of dichlorosilane (SitbCIt) were added to form a complex mixture, yielding a white solid adduct. The reaction mixture was cooled to 0 °C and, with stirring,
72 g of dry ammonia was blown into it.

After the reaction is complete, dry nitrogen is blown in to remove unreacted ammonia, followed by pressure filtration under a nitrogen atmosphere to obtain a filtrate 85 (
b++j! I got it. Add 1.0 ml of dry O-xylene to this filtrate.
When OOd was added and the solvent was removed under reduced pressure, 41.2
g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 540 as measured by GPC. Furthermore, when the polymer was subjected to 'H-NMR analysis in the same manner as in Example 1, as shown in Table 1, 5iC)l:+/(SiHz+Silli =
2.1 was read.

Further, the elemental composition (wt%) of the polymer is Si:52.
8. N:22.4. O: 1.9, C: 16
．． There was 2”?

on the school plate The reaction was carried out using the same apparatus as in Example 1.

That is, after replacing the inside of the reactor installed in a constant temperature bath with a temperature of O''C with dry nitrogen, 900 d of dry pyridine was added and maintained until the temperature became constant, and then 101.0 g of dichlorosilane (SiHzCfz) was added while stirring. was added to obtain a white solid adduct. The reaction mixture was cooled to 0° C. and 72 g of dry ammonia was bubbled in while stirring.

After the reaction was completed, dry nitrogen was blown in to remove unreacted ammonia, and the filtrate was filtered under pressure under a nitrogen atmosphere to obtain a filtrate of 850
rR1 was obtained. Add 1000 d of dry 0-xylene to this filtrate.
When the solvent was removed under reduced pressure, 39.5 g of colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 1260 as measured by GPC. In addition, the polymer in Example 1
When 'H-NMR analysis was performed in the same manner as above, 5iCI
+, absorption was not observed, and as shown in Table 1, 5iCH
s/(SiHz+5iH)=O,O.

Further, the elemental composition (wt%) of the polymer is Si:64.
3. N: 26.8. O: 1.9, C: 2
．． It was 6.

Stop opening I The reaction was carried out using the same apparatus as in Example 1.

That is, after purging the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, 900 d of dry pyridine was added and the temperature was maintained until the temperature became constant, and then methyldichlorosilane (CIlsSillCj2 z) 115 .0
g was added to obtain a white solid adduct. The reaction mixture was cooled to 0 °C and, with stirring, 72 g of dry ammonia was added.
Infused.

After the reaction was completed, dry nitrogen was blown in to remove unreacted ammonia, and the filtrate was filtered under pressure under a nitrogen atmosphere to obtain a filtrate of 850
mj! I got it. Add 1000 d of dry 0-xylene to this filtrate.
When the solvent was removed under reduced pressure, 40.5 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 380 as measured by GPC. Further, when the polymer was subjected to 'H-NMR analysis in the same manner as in Example 1, as shown in Table 1, 5iCH+/(SiHz+5iH)-3,0
It was read that.

Further, the elemental composition (wt%) of the polymer is Si:48.
2. N: 21.6. O: 1.6, C: 20
．． It was 5.

Fruit 1111 The reaction was carried out using the same apparatus as in Example 1.

That is, after replacing the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, 200mf of dry pyridine and 700111i of dry dichloromethane were added. was added and held until the temperature became constant, then ethyldichlorosilane (Cd
lsSillCl g) 25.8 g 1 dichlorosilane (SillzCf□) 80.3 g were added respectively to form a complex compound to obtain a white solid adduct. The reaction mixture was cooled to 0° C. and 72 g of dry ammonia were bubbled in while stirring.

After the reaction is completed, dry nitrogen is blown in to remove unreacted ammonia, and the filtrate is filtered under pressure under a nitrogen atmosphere.
I got d. When 1000 d of dry O-xylene was added to this filtrate and the solvent was removed under reduced pressure, 39.5 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 720 as measured by GPC.

Implementation 1 The reaction was carried out using the same apparatus as in Example 1.

That is, after replacing the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, 900 d of dry T-picoline was added and maintained until the temperature became constant, and then phenyldichlorosilane (CaHsSiHCj !t) 35.8
g, dichlorosilane (SiHzC!2t) 80.
3 g of each were added to form a complex mixture to obtain a white solid adduct. The reaction mixture was cooled to 0° C. and 72 g of dry ammonia were bubbled in while stirring.

After the reaction is completed, dry nitrogen is blown in to remove unreacted ammonia, and the filtrate is filtered under pressure under a nitrogen atmosphere.
I got IIN. Add 1000ml of dry 0-xylene to this filtrate.
When the solvent was removed under reduced pressure, 45.5 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 680 as measured by GPC.

124.0 g of Grignard reagent synthesized from dichlorohexyl bromide was slowly added to 220 g of trichlorosilane. Distillation under reduced pressure yielded 32.8 g of cyclohexyldichlorosilane.

The same equipment as in Example 1 was used. After replacing the inside of the reactor installed in a constant temperature bath with a temperature of 0°C with dry nitrogen, add 900% of dry pyridine and maintain it until the temperature becomes constant, then add 35.0% of cyclohexyldichlorosilane while stirring.
g and 80.3 g of dichlorosilane were respectively added to form a complex mixture to obtain a white solid adduct. The reactor mixture was cooled to 0° C., and 72 g of dry ammonia was blown into the reactor while stirring.

After the reaction is completed, dry nitrogen is blown in to remove unreacted ammonia, and the filtrate is filtered under pressure under a nitrogen atmosphere.
IIIIf/, was obtained. Add 10% of dry 0-xylene to this filtrate.
When 00II11 was added and the solvent was removed under reduced pressure, 3
6.5 g of a colorless viscous liquid was obtained.

The number average molecular weight of this viscous liquid was 700 as measured by GPC.

Table 1 'H-NMR (ratio) The copolymerized silazane obtained in Example 1 was
A gray-black solid was obtained in a yield of 85.2% by weight by heating to °C at a temperature increase rate of 3 °C/min and thermal decomposition.

When the obtained ceramic was subjected to powder X-ray diffraction measurement, it was confirmed that it was amorphous.

Next, this solid was further heated and calcined in nitrogen at a heating rate of 10° C./min to 1700° C. to obtain a black-green solid.

Powder X-ray diffraction measurements of this substance revealed that 2θ=
(101) diffraction line of α-5iJa at 20.5°, 2θ-
(110) diffraction line of α-5i, N, at 22,9°, 2θ
(200) diffraction line of α-S43N4 at -2664°, 2
(201) diffraction line of α-3i3N4 at θ=30.9',
(002) diffraction line of α5iJ4 at 2θ=31.7°, 2
α-5iJ4(7) (102) diffraction line at θ=34.5', 2θ=35.2°near -5iJ4no(210) diffraction line, 2θ=38.8°ni(X 5j3Na (7
) (211) diffraction line, α-5i3N at 2θ=39.4°
(112) diffraction line of n, α-3iJ at 2θ=40.1'
, (300) diffraction line, α-5iJ at 2θ=41.8°
(202) diffraction line of n, 2θ-43, 4° Ni α-5iJ
a-(301) diffraction line, α-5i at 2θ=46.9°
3N, (220) diffraction line, α-5 at 2θ = 48.2°
(212) diffraction line of i, N, α- at 2θ=48.8'
The (310) diffraction line of 5i3N4, and the (110) diffraction line of β-Si, N, at 2θ = 23.3°, 2θ = 26.9
(200) diffraction line of β5sJa at °, 2θ = 33.6°
(101) diffraction line of β-3iJ4, 2θ=36.0'
(210) diffraction line of β-5iJn, 2θ=41.4
β−3iJs (′) (201) diffraction line at °, 2 θ=
49.9'! , :β-3iJ4(')(310) diffraction line, 2θ=34.2°niry-5iC(7) (10
1) Diffraction line, 2θ = 35.7° nicx -3iC (7)
(006) diffraction line, (102) diffraction line, 2θ=38.
(103) diffraction line of α-5iC at 2°, 2θ=41.5
A (104) diffraction line of α-5iC was observed at 10°C, confirming that it was a crystalline silicon nitride-silicon carbide mixed ceramic.

The elemental analysis results of this crystalline mixed ceramic are (wt%
) Si:62.3. N: 25.8.0: 4
．． 2, C near, 5.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus used to produce random copolymerized silazane in Examples, and FIG. 2 is a 'H-NMR spectrum of the random copolymerized silazane of Examples. DESCRIPTION OF SYMBOLS 1...Inorganic halosilane storage tank, 2...Organic halosilane storage tank, 3...Solvent storage tank, 4...Reactor, 6...
・Ammonia gas pipe, 7... Constant temperature chamber. Synthesizer @1 diagram

Claims (2)

[Claims] 1. General formula SiH_2X_2 (in the formula, X is a halogen atom)
Inorganic dihalosilane and general formula RSi(H)X_
It is a copolymerized silazane synthesized by reacting the complex mixture obtained by reacting the organo(hydro)dihalosilane shown in 2 with a Lewis base with ammonia, and has a general formula, ▲ mathematical formula, chemical formula, table, etc. ▼ and ▲
There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R is an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylamino group, an aralkyl group, or an alkylsilyl group. A copolymerized silazane having a linear structure randomly having units represented by the following formula and having a number average molecular weight within the range of 100 to 50,000. 2. General formula SiH_2X_2 (in the formula, X is a halogen atom)
Inorganic dihalosilane and general formula RSi(H)X_
A method for producing a copolymerized silazane, which comprises reacting a complex mixture obtained by reacting an organo(hydro)dihalosilane represented by 2 with a Lewis base with ammonia.