JPH01203429A - Modified polysilazane and production thereof - Google Patents

Abstract

PURPOSE:To obtain modified polysilazane suitable as a precursor for silicone nitride and silicon nitride-containing ceramic, by reacting a specific polysilazane with a secondary amine and substituted hydrazine under a basic condition. CONSTITUTION:(A) A polysilazane which contains one or more hydrogens on silicon atom. and has 100-50,000 average molecular weight is reacted with (B) a secondary amine or a 1,1,2-substituted hydrazine under a basic condition to give a modified polysilazane shown by formula I or formula II [-NR<3>R<4> is secondary amine residue; -N(R<5>)NR<3>R<4> is 1,1,2-substituted hydrazine residue].

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a modified polysilazane and a method for producing the same;
More specifically, the present invention relates to a modified polysilazane that can be used as a precursor for silicon nitride and silicon nitride-containing ceramics, and a method for producing the same.

[Prior art]

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 great 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 carbon, 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 method (2), not only is it difficult to purify the raw materials, but the reaction time is long, and the product obtained is a mixed system of α-type silicon nitride and β-type silicon nitride. Generally, it is amorphous, and although method (2) has the advantage of producing high-purity α-type silicon nitride in good yield, silicon diimide (silicon diimide, which is a silicon nitride precursor)
Since Si(NH)2]x is not soluble in solvents, it has drawbacks such as its practical use being 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 (Hajime Saito, Journal of the Japan Institute of Textile Technology,
VoQ 38 &1, pp. 65-72 (1982), however, this method had the disadvantage that silicon carbide and free carbon were produced simultaneously with silicon nitride.

On the other hand, inorganic polysilazane that is soluble in solvents is
5 tack in a year (Bar, 54. (1921)
, p740), etc., and in 1983, 5eyferth (Co+um, Am.

Ceram, Soc, C-13/14. (83)3 and others have shown 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 Publication No. 59-2011).
No. 7812).

However, in the conventional manufacturing method of inorganic polysilazane, since highly volatile dichlorosilane is used as a raw material in all cases, the polysilazane produced sticks to the gas piping or the reactor wall of the reactor and damages the gas flow path. - 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 it should not be stored in a closed container at low temperatures. There were disadvantages such as complicated handling, such as having to put it in and use it. Furthermore, in the case of synthesized polysilazane such as 5tack.

It is only an oligomer with n=7-8 having the structure -(SiH,NH)n-, and is a viscous liquid at room temperature.
In the case of yferth etc., it has a more complicated structure than in the case of 5tack etc., and the proton ratio of 5i-H/N-H is about 3.
．． It is an oil-like liquid in step 3, but it is heated at about 200°C.
Alternatively, it solidifies by being left at room temperature for 3 to 5 days, and any polysilazane has sufficient properties to be used as a precursor for a silicon nitride sintered body shaped at room temperature. I couldn't say that I was doing it.

Therefore, it has been desired to develop a method for easily synthesizing polysilazane with higher molecular weight and stringability, which is useful as a silicon nitride precursor, with higher yield.

〔the purpose〕

An object of the present invention is to provide a novel modified polysilazane suitable as a silicon nitride precursor.

〔composition〕

According to the present invention, there is provided a modified polysilazane characterized in that bonds represented by the following general formulas (1) to (If) are introduced into polysilazane molecules having a number average molecular weight of 100 to 50,000.

General formula (1) General formula (II) /R'``N' ``IXR・ (In the formula, -NR' represents a 1,1,2-substituted hydrazine residue) of the modified polysilazane of the present invention The raw material polysilazane used as a starting material has at least one hydrogen atom in a silicon atom, and has a skeleton represented by the following general formula.

In the above formula, nl and R2 are a hydrogen atom, or an alkyl group or alkenyl group which may have a substituent.

It represents a cycloalkyl group, alkylamino group, aryl group, aralkyl group or alkylsilyl group. In this case, the alkyl group includes methyl, ethyl, propyl,
Examples include butyl, octyl, decyl, etc., alkenyl groups include vinyl, allyl, butenyl, octenyl, decenyl, etc., cycloalkyl groups include cyclohexyl, methylcyclohexyl, etc., and alkylamino groups include: Examples of the aryl group include phenyl, tolyl, xylyl, naphthyl, etc., examples of the aralkyl group include benzyl group, and examples of the alkylsilyl group include methylsilyl, ethylsilyl, propylsilyl,
Examples include butylsilyl, octylsilyl, decylsilyl and the like. Also.

The substituent may be any substituent as long as it does not show reactivity with the hydrogen atom bonded to the silicon atom, and examples thereof include an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, and the like.

The raw material polysilazane of the present invention has a number average molecular weight of 100 to so, ooo, and is composed of a cyclic polysilazane, a chain polysilazane, or a mixture thereof.

The raw material polysilazane preferably used in the present invention has a number average molecular weight of 300 to 2000, preferably 600 to 1.
, 000 chain polysilazane.

The polysilazane shown above can be synthesized by a conventionally known method as shown below.

■Patent issued by the inventor, 11i (Jikai 6O-145903)
・5iHzC& +2Py →5iH2(4・2Py
adduct・5iH2CQ2・2Py adduct
+ 3NHx→-+Sin, N old y” 2NH4
CQ” 2Py■D, 5eyferth et al. (USP
4,397,828) ■A, 5 tack (Ber, 54
．． (1921), P-740) Benzene・SiH, (4+ 3NH, −→ −(SiH, Nu
Ciba + 2NH4CΩ■S, M, 5cantlin et al., Inorg, Chem, 1972, 11■ B, J,
Aylett (USP 3,318,823)・Si
n, Cmu + M also N) I → H, Si (Su too) 20N~N
H・HCQ・H,Si(Me,), + Mell
JH, → −(H, SiNMe)■ + Ne, NH
+ 1%■D, 5eyferth et al. (tlsP 4,
482,669)・MeSi)ICQ, + 2P
y-4MeSiHCfl, 2Py adduc
t・MaSiH(122・2Py adduct
+ 3NH, → (MaSiHNH% + 2Py
+ 2NH, CI2 In the present invention, the polysilazane as the starting material is subjected to a dehydrogenation condensation reaction (hereinafter also simply referred to as condensation reaction) with a secondary amine or 1,1.2-substituted hydrazine under basic conditions.

Aromatic and aliphatic secondary amines can be used as the secondary amine in the present invention, and can be represented by the following general formula.

In this formula, R'' and R' represent an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group which may have a substituent as in the case of R1 and R2.

Specific examples of this secondary amine include dimethylamine, diethylamine, methylethylamine, dipropylamine, diisopropylamine, methylpropylamine, dibutylamine, cyamylamine, diallylamine, diheptylamine, dioctylamine, diallylamine, allylcyclohexyl amine, methylaniline,
Examples include ethylaniline, dibenzylamine, diphenylamine, dicyclohexylamine, and N-cyclohexylaniline.

1, 1.2-! in the present invention! As converted hydrazine,
What is represented by the following general formula can be used.

In this formula, R3, R4, and R5 represent an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group that may have a substituent as in the case of R1 and R2.

Specific examples of the 1,1,2-substituted hydrazine include trimethylhydrazine, triethylhydrazine,
Tripropylhydrazine, triphenylhydrazine, 1
．． Examples include 2-dimethyl-1-phenylhydrazine, 1,1-dimethyl-2-phenylhydrazine, and benzylidenemethylhydrazine.

The basic conditions for the reaction in the present invention include:
This means that a basic compound such as tertiary amines, secondary amines having a sterically hindered group, phosphine, etc. is allowed to coexist in the reaction system.

Such basic conditions can be formed by adding a basic compound to the reaction solvent, or by using a basic solvent or a mixture of a basic solvent and a non-basic solvent as the reaction solvent. Can be done. The amount of the basic compound added is at least 5 parts by weight per 100 parts by weight of the reaction solvent.
Parts by weight, preferably 20 parts by weight or more. If the amount of the basic compound added is less than this, the condensation reaction will not be smoothly promoted.

Any basic solvent can be used as long as it does not decompose the starting material polysilazane. Examples of such substances include trialkylamines such as trimethylamine, dimethylethylamine, diethylmethylamine, and triethylamine; tertiary amines such as pyridine, picoline, dimethylaniline, pyrazine, pyrimidine, pyridazine, and derivatives thereof; , pyrrole, 3-pyrroline, pyrazole, 2-pyrazoline, and mixtures thereof. Examples of non-basic solvents include hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons; halogenated hydrocarbons such as halogenated methane, halogenated ethane, and halogenated benzene; Ethers such as group ethers and alicyclic ethers can be used. Preferred solvents include halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride, trichloroethane, and tetrachloroethane, ethyl ether,
Ethers such as isopropyl ether, ethyl butyl ether, butyl ether, 1,2-dioxyethane, dioxane, dimethyldioxane, tetrahydrofuran, and tetrahydropyran.

Pentane, hexane, isohexane, methylpentane,
Hydrocarbons such as heptane, isohbutane, octane, isooctane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, and ethylbenzene.

The condensation reaction of the present invention is preferably carried out in a solvent as described above, and in this case, the concentration of the raw material polysilazane in the solvent is 0.01 to 50% by weight, preferably 0.1 to 20% by weight. If the concentration of polysilazane is lower than this, the intermolecular condensation 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 formed, which is not preferable. The reaction temperature is -78 to 300°C, preferably -4
The temperature range is from 0 to 200° C. At lower temperatures, the condensation reaction does not proceed sufficiently, and at higher temperatures, the condensation reaction proceeds too much and forms a gel. In addition, the amount of secondary amine or 1,1.2-substituted hydrazine used as a condensation reaction agent is the molar ratio to 1 mole (average mole) of polysilazane.
It is in the range of 0.01 to 5,000, preferably 0.5 to 1,000; if it is lower than that, the condensation reaction will not proceed sufficiently, and if it is higher than that, the condensation reaction will proceed too much and form a gel. As the reaction atmosphere, air can be used, but preferably a basic atmosphere consisting of a secondary amine, substituted hydrazine or other amine or hydrazine, dry nitrogen,
An inert gas atmosphere such as dry argon or a mixture thereof is used. In the condensation reaction of the present invention, pressure is applied during the reaction due to the raw material secondary amine or 1,1,2-substituted hydrazine and by-product hydrogen, but pressurization is not necessarily necessary and normal pressure is used. can do.

Note that the reaction time varies depending on various conditions such as the type and concentration of the starting material polysilazane, the type and concentration of the basic solvent, the amount of secondary amine or 1,1,2-substituted hydrazine added, and the condensation reaction temperature. But - 0.5 for boat fishing
A range of 20 hours is sufficient.

The optimum conditions for the condensation reaction vary depending on the average molecular weight and molecular weight distribution of the starting polysilazane and the molecular structure of the modified polysilazane, and on whether a secondary amine or a 1,1.degree. 2-substituted hydrazine is selected. A general consideration in setting conditions is that the lower the average molecular weight of the starting polysilazane, the more stringent conditions (temperature, reaction time) are required.

In the present invention, when the condensation reaction is carried out using a basic solvent, the basic solvent solution containing the resulting modified polysilazane is adjusted to have a basic solvent content of 30% by weight or less in the total solvent. The basic solvent is preferably 5 weight meters or less.

Since the modified polysilazane acts as an intermolecular condensation reaction catalyst, if its proportion to the solvent is too large, it will form a gel during long-term storage at room temperature. This adjustment of the solvent composition can be carried out, for example, by evaporating the modified polysilazane solution containing the basic compound obtained in the condensation reaction step to remove the basic compound contained therein. This can be done by adding a solvent. When the content of basic compounds in the solution is high,
When a basic reaction solvent is used, a stable solution composition can be obtained by repeatedly performing the solution composition adjustment process consisting of evaporation removal of the basic compound and addition of a non-basic solvent. In the present invention, the basic solvent for forming a stable solution of the modified polysilazane includes aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, and aliphatic hydrocarbons as shown above. Group ethers, alicyclic ethers, etc. can be used.

Polysilazane and secondary amine or 1,1 in the present invention
．． The condensation reaction with 2-substituted hydrazine is thought to include the following elementary reactions.

(1) Reaction of polysilazane and secondary amine, R3 (2) Reaction of polysilazane and 1.1.2-substituted hydrazine/.

The modified polysilazane of the present invention is a polymer produced by the condensation reaction of the raw material polysilazane and a secondary amine or a 1,1,2-substituted hydrazine as described above. Formula (1)-(II)
The modified polysilazane of the present invention, which has a high molecular weight by introducing a new bond as shown in 1, is characterized by the following molecular structure compared to the raw material polysilazane.

(1) The proportion of nitrogen atoms bonded to silicon atoms increases 0
As mentioned above, the modified polysilazane of the present invention contains a new bonding group, and the proportion of nitrogen atoms based on this bonding group increases. The upper limit of the ratio (N/Si) of nitrogen atoms bonded to silicon atoms in the modified polysilazane and silicon atoms is the range in which gelation of the modified polysilazane does not occur, in other words, the range in which solvent solubility is exhibited. Although it is specified within 1, usually 2
．． It is 5 or less, preferably 2.0 or less.

(2) The number average molecular weight range is usually 200 to soo, o
The modified polysilazane of the present invention, which is oo, uses a polysilazane having a number average molecular weight of 100 to so, ooo as a raw material as described above, and this is used as a secondary amine or a 1,1.2-
Since it is formed by polymerizing substituted hydrazine as a reactant, its molecular weight is naturally higher than that of the raw material polysilazane. - For boat fishing, the modified polysilazane targeted by the present invention has a number average molecular weight of 200-500,000. Preferably, it has 1500 to 10,000.

The modified polysilazane of the present invention has the above-mentioned characteristics in terms of molecular structure and is distinguished from the raw material polysilazane, but one of its other characteristics is that it has many branched structures. be. Due to this branched structure, the modified polysilazane of the present invention has a higher molecular weight than the raw material polysilazane, but rather provides improved solvent solubility. The inorganic silazane proposed by 5eyferth et al. has a proton ratio of 5L-H/N-H of about 3.
．． 3.It is an oil-like liquid that can be heated at about 200℃, or
It solidifies by being left at room temperature for 3 to 5 days. In contrast, the modified polysilazane of the present invention has a
It has a molecular weight of soo, ooo, contains a new bonding group as described above, has a nitrogen atom to silicon atom ratio (N/SL) higher than that of the raw material polysilazane, and is resolubilable in a solvent. The reason why the modified polysilazane of the present invention has a more branched structure than the raw material polysilazane is that in the condensation reaction of the present invention, a disproportionation reaction of polysilazane occurs in addition to the condensation reaction. it is conceivable that.

The modified polysilazane of the present invention has the above-mentioned molecular structural characteristics, and although it has new physical properties, it is often soluble in organic solvents, and in particular, it is soluble in organic solvents. The removed solid polymer exhibits a significant feature of being re-soluble in the solvent. Conventional polysilazane has poor stability, and when the solvent is removed from the solution, a resinous solid is produced, which is insoluble in the solvent, but the modified polysilazane of the present invention does not exhibit this tendency. . Therefore, while conventional polysilazane is impossible or extremely difficult to handle as a solid polymer, the modified polysilazane of the present invention can be easily handled as a solid polymer.

〔effect〕

The modified polysilazane of the present invention has the above-mentioned molecular structure and physical characteristics, and can be used in various fields. Next, the usage and production characteristics of the modified polysilazane of the present invention will be shown.

■ Modified polysilazane is soluble in organic solvents and can be converted into silicon nitride or silicon nitride-containing ceramics by firing, so it can be used as a high-performance ceramic molded product, with high high-temperature mechanical strength, heat resistance, corrosion resistance, and oxidation resistance. Continuous fibers, films, and coatings with excellent properties and thermal shock resistance can be easily obtained. Moreover, since the ceramic yield is high, it can also be used as a binder for sintering, an impregnating agent, etc.

■ Modified polysilazane does not contain impurities such as residual catalyst that promote decomposition in its polymer.

Stability is improved, handling becomes easier, and the purity of the ceramic after high-temperature firing is improved.

- Modified polysilazane has an increased molecular weight compared to 1M polysilazane, so it has improved coagulability and can be shaped quickly at room temperature.

■ Since a catalyst such as a transition metal is not used, there is no need for a separation process between the product and the catalyst.

■ Since no catalyst remains in the modified polysilazane, its stability is improved and it can be stored for a long time even after the solvent is removed and isolated.

■ It is low cost and safe because it does not use expensive and dangerous catalysts.

■ Due to its high molecular weight, evaporation loss during high-temperature firing is small, improving ceramic yield.

■ Since there are no impurities mixed in, the purity of ceramics after high-temperature firing is improved.

■ When spinning modified polysilazane, continuous spinning is possible without adding a spinning aid.

[Phase] Modified polysilazane has a melting point, so after melting,
It also becomes possible to formulate it.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Reference Example 1 A four-loop flask with an internal volume of IQ was equipped with a gas blowing pipe, a mechanical stirrer, and a dewar condenser. After purging the inside of the reactor with deoxygenated dry nitrogen, 490 mα of degassed dry pyridine was placed in a four-bottle flask and cooled with water. Next, when 51.6 g of dichlorosilane was added, a white solid adduct (SiH, CQ, 2G,) was formed.
N) was generated. The reaction mixture was cooled on ice and stirred.
51.0 g of purified ammonia was blown 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 850 mQ of filtrate. The solvent was distilled off from 5 mQ of the filtrate under reduced pressure to obtain 0.102 g of solid resin perhydropolysilazane.

The number average molecular weight of the obtained polymer was 980 as measured by GPC. Also, the IR of this polymer
(Infrared absorption) spectrum (solvent: dry 0-xylene; concentration of perhydropolysilazane: 10.2 g When considering D, the wave number (Ql-1) is 3350 (apparent extinction coefficient ε = 0.557 Q g-" Low 1) and 1175
Absorption based on NH of 2170 (ε=3.14.); Absorption based on SLH of 2170 (ε=3.14.); Absorption based on SiH and 5iNSi of 1020 to 820. In addition, 1HNMR (proton nuclear magnetic resonance) spectrum of this polymer (60A &, solvent CDCQ, / reference material TM
S), it was confirmed that all of them exhibited a wide range of absorption. That is, δ4.8 and 4.4 (br,
5iH); Absorption of 1,5 (br, NH) was confirmed.

Reference example 2 The reaction was carried out using the same apparatus as in Reference Example 1.

That is, 500 mQ of degassed dry dichloromethane was placed in the fourth flask shown in Reference Example 1 and cooled on ice.

Next, 48.6 g of dichlorosilane was added. This solution was cooled with water, and while stirring, 42.5 g of purified ammonia was blown into the solution as a mixed gas with nitrogen through a sodium hydroxide tube and an activated carbon tube. During the reaction, powder mist was generated in the gas flow path, so the gas flow path was occasionally tapped to prevent clogging.

The reaction mixture was treated in the same manner as in Reference Example 1 to obtain 9.6 g of viscous oily perhydropolysilazane. The number average molecular weight of the obtained polymer was 640 as measured by GPC.
Met.

Reference example 3 The reaction was carried out using the same apparatus as in Reference Example 1.

That is, 450 mQ of degassed dry tetrahydrofuran was placed in the four-bottle flask shown in Reference Example 1, and 46.2 g of dichlorosilane cooled in a dry ice-methanol bath was added thereto. This solution was cooled, and 44.2 g of anhydrous methylamine was blown in as a mixed gas with nitrogen while stirring.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry tetrahydrofuran, and then filtered under a nitrogen atmosphere to obtain 820 mn of filtrate. When the solvent was distilled off under reduced pressure, 8.4 g of viscous oily N-methylsilazane was obtained. The number average molecular weight of the obtained polymer was 1100 as measured by GPC.

Reference example 4 A gas blowing tube is placed in a four-loaf flask with an internal volume of IQ.

After purging the inside of the 0 reactor equipped with a mechanical stirrer and dewar condenser with deoxygenated dry nitrogen, 300 m of dry dichloromethane Q and 24.3 g of methyldichlorosilane (0,2111 II
oQ) and cooled on ice. Ammonia purified through a sodium hydroxide tube and an activated carbon tube with stirring 18.
1 g (1,06+o Q ) was injected.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry dichloromethane, and filtered under a nitrogen atmosphere. When the solvent was distilled off from the filtrate under reduced pressure, 8.81 g of a colorless and transparent liquid was obtained.
Obtained. The number average molecular weight of this product was 380 as measured by GPC.

Reference example 5 The reaction was carried out using the same apparatus as in Reference Example 1.

That is, 450 mQ of degassed dry benzene was placed in the four-loaf flask shown in Reference Example 1, and this was cooled with water.

Next, 40.6 g of dichlorosilane was added. This solution was water-cooled, and while stirring, 42.0 g of purified ammonia was blown in as a mixed gas with nitrogen through a sodium hydroxide tube and an activated carbon tube.During the reaction, powder mist was generated in the gas flow path. Occasionally tap to prevent blockage.

The reaction mixture was treated in the same manner as in Reference Example 1 to obtain 5.2 g of viscous oily perhydropolysilazane. The number average molecular weight of the obtained polymer was 32 as measured by GPC.
It was 0.

Reference Example 6 A mechanical stirrer and a dewar condenser were used to drip the liquid into a four-loaf flask with an internal volume of IQ. After replacing the inside of the reactor with deoxygenated dry nitrogen, 400 m of degassed dry benzene was placed in a four-bottle flask and a known method (
J, Am, Chem, Soc, , Vol, 67, 18
13 (1945)). 64.5 g of allyldichlorosilane was added and stirred. A known method (J, Am, Chem, Soc, vol 70, 43)
5 (194 g))
2.5g and 5omQ of dry benzene were added. A benzene solution of triethylaminosilane was added dropwise to a benzene solution of allyldichlorosilane. After the dropwise addition was completed, the reaction was carried out by heating and refluxing in an oil bath while stirring.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry benzene, and further filtered under a nitrogen atmosphere to obtain 680 mQ of filtrate. When the solvent is removed from the filtrate, liquid N is produced.
-()-ethylsilyl)allylsilazane is 19.2g
Obtained. The number average molecular weight of the obtained polymer was 360 as measured by GPC.

Reference Example 7 62.0 g of Grignard reagent synthesized from cyclohexyl bromide was slowly added to 110 g of trichlorosilane. Distillation under reduced pressure yielded 16.4 g of cyclohexyldichlorosilane. The same apparatus as in Reference Example 6 was used. 12.0 g of cyclohexyldichlorosilane and 420 mQ of dry benzene were placed in a four-bottle flask and stirred. 1,1-dimethylhydrazine 15.6 in the dripping noodles
g and 40 m of dry benzene were added.

A benzene solution of 1.1-dimethylhydrazine was added dropwise to a benzene solution of cyclohexyldichlorosilane. After completion of the dropwise addition, the reaction was carried out at room temperature with stirring.

After the reaction was completed, the reaction mixture was centrifuged, washed with dry benzene, and further filtered under a nitrogen atmosphere to obtain 730mQ of filtrate. When the solvent is removed from the filtrate, an oily N-
(dimethylamino)cyclohexylsilazane 3.2g
Obtained. The number average molecular weight of the obtained polymer was 390 as measured by GPC.

Reference example 8 The reaction was carried out using the same apparatus as in Reference Example 1.

That is, 500 mQ of degassed dry toluene was placed in the four-loaf flask shown in Reference Example 1 and cooled on ice. Next, 52.1 g of phenyldichlorosilane was added. This solution was ice-cooled, and while stirring, 30.0 g of purified ammonia was blown into the solution as a mixed gas with nitrogen through a sodium hydroxide tube and an activated carbon tube.

The reaction mixture was treated in the same manner as in Reference Example 1 to obtain 6.8 g of oily phenylpolysilazane. The number average molecular weight of the obtained polymer was 380 as measured by GPC.

Example 1 Pyridine solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane, 10.3% by weight)
) 100 mQ into a pressure-resistant reaction vessel with an internal volume of 300 mQ,
Dehydrated diethylamine 3+nQ (29,0mmoQ
) was added, and the reaction was carried out in a closed system at 110°C with stirring for 3 hours. During this time, a large amount of gas was generated, which was determined to be hydrogen by gas chromatography (GC) measurements. The pressure increase before and after the reaction is 2.2 kg/a
It was J. After cooling to room temperature, dry. -Xylene 200-
was added and the solvent was removed at a pressure of 3-5 mmHg and a temperature of 50-70'C, yielding 8.6 g of white powder.

This powder was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of the polymer powder was 5240 as measured by GPC. In addition, as a result of analysis of its IR spectrum (solvent: toluene), the wave number (am-”
) 3350 and 1175 NH-based absorption; 217
Absorption based on SLH of 0; 1020-820(i')S
Absorption based on iH and 5iNSi; 2690.293
0.2880.146o, 1380 (7) CH-based absorption; 1090 CN-based absorption was confirmed. Furthermore, the 18NMR spectrum of the polymer powder (
As a result of analyzing COCO2, TMS), δ4.8 (br
.

SiH,), δ4.4 (br, Sin,), δ2.7
(br, CH,), 61.4 (br, NH), δ0.9
Absorption of (br, CH,) was measured. In addition, the elemental analysis results of the polymer powder are based on weight, Si: 50.1
%, N: 25.8%, C: 12.4%, O: 3.6%,
H near was 3%.

Example 2 A γ-picoline solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane, 5.76% by weight) was placed in a pressure-resistant reaction vessel with an internal volume of 300 μm, and 5.0 μl of trimethylhydrazine was added. was added, and the reaction was carried out in a closed system at 120°C with stirring for 3 hours.

During this time, a large amount of gas was generated. The pressure before and after the reaction is 2.0
kg/a! Rose. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 4.2 g of white powder was obtained, and this powder was soluble in the organic solvent.

The number average molecular weight of the polymer powder was 3080 as measured by GPC.

Example 3 Pyridine solution of perhydropolysilazane obtained in Reference Example 2 (concentration of perhydropolysilazane, 7.04% by weight)
) 100mQ into a pressure-resistant reaction vessel with an internal volume of 300-
25 mQ of N-methylaniline was added and the reaction was carried out in a closed system at 100°C with stirring for 6 hours. During this time, a large amount of gas was generated, and the pressure rose by L8 kg/ci before and after the reaction. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 6.8 g of pale yellow powder was obtained, and this powder was soluble in the organic solvent. When its number average molecular weight was measured by GPC,
It was 2740.

Example 4 60 ml of a pyridine solution of N-methylsilazane obtained in Reference Example 3 (concentration of N-methylsilazane 12.4% by weight)
was placed in a pressure-resistant reaction vessel with an internal volume of 300 mQ, 20.0 g of 1,2-dimethyl-1-phenylhydrazine was added, and the reaction was carried out in a closed system at 150°C with stirring for 5 hours.

During this time, gas generation was observed, and the pressure was 0.3 kg before and after the reaction.
/d rose. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 6.3 g of a pale yellow waxy solid was obtained, and the number average molecular weight by GPC was 1480. The melting point of this solid was approximately 200°C.

Example 5 100 mQ of the pyridine solution of methylsilazane obtained in Reference Example 4 (concentration of methylsilazane, 8.16% by weight) was placed in a pressure-resistant reaction vessel with an internal volume of 300 -, and 15.0 - of dipropylamine was added. The reaction was carried out in a closed system at 120°C with stirring for 6 hours. During this time, gas generation was observed,
The pressure increased by 0.4 kg/a# before and after the reaction.

When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 7.8 g of a white waxy solid was obtained, and the number average molecular weight by GPC was 1720.

Example 6 Pyridine solution of perhydropolysilazane obtained in Reference Example 5 (concentration of perhydropolysilazane, 5.59% by weight)
)100- was placed in a pressure-resistant reaction vessel with an internal volume of 300, 8.0- of trimethylhydrazine was added, and the mixture was heated to 120°C in a closed system.
The reaction was carried out with stirring for 3 hours.

During this time, a large amount of gas was generated. The pressure before and after the reaction is 0.8
kg/cJ increased. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 5.2 g of white powder was obtained. This powder was soluble in organic solvents, and its number average molecular weight was determined by GPC to be 22.
It was 50.

Example 7 A pyridine solution of N-(triethylsilyl)allylsilazane obtained in Reference Example 6 (concentration of N-(triethylsilyl)allylsilazane, 6.47% by weight) 60- was reduced to an internal volume of 3
00d pressure-resistant reaction vessel, diethylamine 15.0
- was added, and the reaction was carried out in a closed system at 160°C with stirring for 6 hours. During this time, gas generation was observed, and the pressure increased by 0.3 kg/cj before and after the reaction. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, a pale yellow waxy solid was obtained with a concentration of 3.2
g was obtained, and its number average molecular weight was found to be 1350 by GPC. The melting point of this solid was approximately 180°C.

Example 8 Pyridine solution of N-(dimethylamino)cyclohexylsilazane obtained in Reference Example 7 (N-(dimethylamino)
Concentration of cyclohexylsilazane, 3.20% by weight) 80
- was placed in a pressure-resistant reaction vessel with an internal volume of 300 -, 10.0 mQ of dibutylamine was added, and the reaction was carried out in a closed system at 120°C with stirring for 8 hours. During this time, gas generation was observed, and the pressure increased by 0.2 kg/a# before and after the reaction.

When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 2.0 g of a pale yellow waxy solid was obtained, the number average molecular weight of which was determined by GPC.
Accordingly, it was 1110. The melting point of this solid is about 150
It was ℃.

Example 9 Pyridine solution of phenylsilazane obtained in Reference Example 8 (
The mixture was placed in a pressure-resistant reaction vessel with a phenylsilazane concentration of 8.14 and an internal volume of 300 d, and 30.0 mQ of dipropylamine was added thereto, and the reaction was carried out in a closed system at 150° C. with stirring for 6 hours. During this time, gas generation was observed, and the pressure increased by 0.4 kg/cd before and after the reaction. When the solvent was distilled off under reduced pressure in the same manner as in Example 1, 7.3 g of a white waxy solid was obtained, and its number average molecular weight was 1,310.

Patent applicant: Toa Fuel Industries Co., Ltd.

Claims (1)

[Claims] (1) A modified polysilazane characterized by introducing a bond represented by the following general formula (I) or (II) into a polysilazane molecule having a number average molecular weight of 100 to 50,000. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ indicates a secondary amine residue) General formula (II) ▲Mathematical formulas, chemical formulas, tables, etc. etc.▼ (In the formula, -N-R^5 represents a 1,1,2-substituted hydrazine residue) (2) A silicon atom with at least one hydrogen atom and a number average molecular weight of 100 to 50, 000 polysilazane under basic conditions with secondary amine or 1,1,2-
Claim 1 characterized in that a substituted hydrazine is reacted.
A method for producing modified polysilazane.