JP2760555B2 - Polyborosilazane and method for producing the same - Google Patents

Description

The present invention relates to a novel polyborosilazane and a method for producing the same. Si-NB-based ceramics made of polyborosilazane as a precursor have heat resistance and high hardness, so they are useful as reinforcing materials for high-temperature composite materials, and are widely used in the space, aviation, and automotive industries. Application can be expected.

[Conventional technology]

Many reports have been made on borosiloxanes, organoborosilanes, and boron-containing carbosilanes obtained by reacting a boron compound such as boric acid (derivative), a metal borate, or a boron halide with an organosilicon compound.

Such an organosilicon compound has a low molecular weight, and only an example using a compound having a size of at most an oligomer is known (Japanese Patent Publication No. 57-26608).

For polysilazane, perhydropolysilazane,
Various reports such as polyorgano (hydro) silazane have been reported, but boron-containing polyborosilazane has not been known.

[Problems to be solved by the invention]

The present inventors have previously disclosed polymetallosilazanes containing metals such as titanium, zirconium, and aluminum.In the course of further research, ceramics obtained by thermally decomposing polyborosilazane have remarkable heat resistance. I found something. Further, by introducing boron into the ceramics, it is possible to improve the hardness, adjust the conductivity, and the like.

That is, an object of the present invention is to provide a polyborosilazane which provides a ceramic exhibiting remarkable heat resistance (high-temperature strength) due to thermal decomposition and a method for producing the same.

[Means for solving the problem]

And according to the present invention, the above object is mainly based on the general formula (I): (Wherein R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a moiety other than these groups that is directly connected to silicon or nitrogen in the formula; Represents a carbon group, an alkylsilyl group, an alkylamino group, or an alkoxy group, provided that R ¹ , R ² , R ³
At least one is a hydrogen atom. And a part of silicon and / or part of nitrogen constituting the main skeleton represented by the following general formula (i), (ii), (iii) or (iv): This is achieved by providing a polyborosilazane, wherein the cross-linking component represented by the formula (1) is bonded, and the B / Si atomic ratio is in the range of 0.01 to 3 and the number average molecular weight is 800 to 500,000. Is done.

(In the formula, R ⁶ is a hydrogen atom, a halogen atom, a carbon atom 1
An alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkoxy group, an alkylamino group, a hydroxyl group, or an amino group having 20 or more, and R ⁷ is bonded to the nitrogen atom of the group having a nitrogen atom among R ⁶ In formula (iv), at least two of a total of six atoms consisting of three nitrogen atoms and boron atoms are used for crosslinking, and R ⁶ is bonded to the remaining atoms be able to. The novel polyborosilazane provided by the present invention is a compound having a high-molecular-weight borosilazane structure containing boron by reacting a higher-molecular-weight polysilazane with a boron compound. That is, the present invention has the first feature in polysilazane used as a raw material for producing polyborosilazane.

The reaction between the polysilazane and the boron compound and the structure of the polymer compound obtained by the reaction depend on the type of the boron compound.

For example, when a boron alkyloxide is used as the boron compound, the resulting polyborosilazane is formed by combining a boron alkoxide with a hydrogen atom bonded to at least a part of silicon atoms and / or a hydrogen atom bonded to a nitrogen atom in the main skeleton of polysilazane. It is a compound characterized by having a side chain or a cyclic or crosslinked structure in which a silicon atom and / or a nitrogen atom is condensed with a boron alkoxide upon reaction.

In the reaction between the Si—H bond of the polysilazane and the boron alkoxide, the organic group (R) of the boron alkoxide [B (OR ⁵ ) ₃ ]
^5), by elimination occurs the R ⁵ H Pull the Si-H bond hydrogen atom, Si-O-B bonds are formed.

On the other hand, in the reaction between the N—H bond of polysilazane and the boron alkoxide, the hydrogen atom of the N—H bond is extracted by the boron alkoxide, and the N—O—B bond or the N—B bond (hereinafter referred to as these Is represented as an N—Y—B bond).

Since the boron alkoxide can be up to trifunctional, the resulting polyborosilazane can be a 1-3 functional polymer with respect to boron, depending on the type of starting boron alkoxide or reaction conditions. The monofunctional polymer has the following structure in which a pendant group is introduced into Si and / or N of the main chain of polysilazane.

A cyclic or crosslinked structure is formed on the polysilazane skeleton of the highly functionalized and trifunctional polysilazane via a B atom. The cyclic structure includes a structure in which two functional groups in one molecule of boron alkoxide are condensed with adjacent silicon and nitrogen atoms of polysilazane. A crosslinked structure occurs when two or more functional groups of a boron alkoxide are condensed with two or more molecules of polysilazane.

Some of the trifunctional polymers have both the above-mentioned cyclic structure and cross-linked structure at the same time. Usually, (VI) or (VI) is obtained by the reaction of polysilazane with boron alkoxide.
The polymer shown in I) is obtained.

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

In the reaction between the Si—H bond of the polysilazane and a substance having a halogen atom among the boron compounds B (R ⁴ ) ₃ , the boron compound BXm (R ⁴ ) _3-m (X is a halogen atom, m = 1, 2, The halogen atom of 3) extracts a hydrogen atom of the Si-H bond to generate HX and desorbs, thereby forming a Si-B bond.

On the other hand, in the reaction between the NH bond of polysilazane and a boron compound having a halogen atom, the hydrogen atom of the NH bond is extracted, and an NB bond is formed as described below.

Boron compound BXm (R ⁴ ) _3-m depends on the number of halogen atoms,
As it can be up to trifunctional, the resulting polyborosilazane can be a 1-3 functional polymer with respect to boron. The monofunctional polymer has the following structure in which a pendant group is introduced into Si and / or N of the main chain of polysilazane.

In a 2-3 functional polymer, a cyclic or crosslinked structure is formed in the polysilazane skeleton via a B atom. The cyclic structure includes a structure in which two functional groups in one molecule of a boron compound are condensed with adjacent silicon atoms and nitrogen atoms of polysilazane. The crosslinked structure has two or more functional groups of the boron compound.
Occurs when condensed with more than one molecule of polysilazane.

Some of the trifunctional polymers have both the above-mentioned cyclic structure and cross-linked structure at the same time.

In the reaction between the Si-H bond of the polysilazane and a substance having a hydrogen atom among the boron compounds B (R ⁴ ) ₃ , the boron compound BH
A hydrogen atom of m (R ⁴ ) _3-m is extracted by extracting a hydrogen atom of the Si—H bond to generate H ₂ and is eliminated, thereby forming a Si—B bond.

On the other hand, in the reaction between the NH bond of polysilazane and the boron compound having a hydrogen atom, the hydrogen atom of the NH bond is extracted, and an NB bond is formed as described below.

Since the boron compound BH _m (R ⁴ ) _3-m can be up to trifunctional depending on the number of hydrogen atoms, the boron atom compound BX
Polyborosilazane having a structure similar to that described for m (R ⁴ ) _3-m can be produced.

Of Si-H bond and a boron compound B polysilazane (R ⁴⁾ _3, alkyl group, alkenyl group, cycloalkyl group, aryl group, the reaction between the substance having an alkylamino group, a boron compound B (R ⁴⁾ ₃ The organic group of is extracted from the hydrogen atom of the Si-H bond to generate R ⁴ H and is desorbed.
A -B bond is formed.

However, when one of the groups bonded to the nitrogen atom in the alkylamino group is a hydrogen atom, a dehydrogenation reaction occurs, and a Si—NB bond is formed by the following reaction.

On the other hand, in the reaction of the N—H bond of polysilazane with a boron compound having an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and an alkylamino group, hydrogen atoms of the N—H bond are extracted, and An NB bond is formed.

Since the boron compound B (R ⁴ ) ₃ can be up to trifunctional, depending on the type of the starting boron compound or the reaction conditions, the resulting polyborosilazane is
It has the same structure as when BXm (R ⁴ ) _3-m or BHm (R ⁴ ) _3-m is used.

In the reaction between the Si—H bond of the polysilazane and a substance having an amino group or a hydroxyl group among the boron compounds B (R ⁴ ) ₃ , the Z of the boron compound BZm (R ⁴ ) _3-m (Z is an amino group or a hydroxyl group)
By hydroxide in is eliminated occurs with H ₂ Pull the Si-H bond hydrogen atom, Si-N-B bond or Si
An -OB bond is formed.

On the other hand, in the reaction between the NH bond of the polysilazane and the boron compound having an amino group or a hydroxyl group, the hydrogen atom of the NH bond is extracted, and the N—N—B bond or the N—O—B A bond is formed.

Since the boron compound BZm (R ⁴ ) _3-m can have up to 3 functionalities depending on the number of amino groups and hydroxyl groups, the resulting polyborosilazane may be a polymer having 1 to 3 functionalities with respect to boron. it can. The monofunctional polymer has the following structure in which a pendant group is introduced into Si and / or N of the main chain of polysilazane.

In a 2-3 functional polymer, a cyclic or crosslinked structure is formed in the polysilazane skeleton via a B atom. The cyclic structure includes a structure in which two functional groups in one molecule of a boron compound are condensed with adjacent silicon atoms and nitrogen atoms of polysilazane. The crosslinked structure has two or more functional groups of the boron compound.
Occurs when condensed with more than one molecule of polysilazane.

Some of the trifunctional polymers have both the above-mentioned cyclic structure and cross-linked structure at the same time.

Si-H bond of polysilazane and boron compound In the reaction with, R ^{4 of the} boron compound abstracts the hydrogen atom of the Si-H bond to form R ⁴ H, which is desorbed.
-B bond or Si-N bond is formed.

On the other hand, the N—H bond of polysilazane and In this reaction, the hydrogen atom of the NH bond is extracted, and an NB bond or an NN bond is formed as described below.

Boron compounds Can be up to six-functional, so that depending on the type of starting boron compound or reaction conditions, the resulting polyborosilazane can be a 1-6 functional polymer with respect to the boron compound. The monofunctional polymer has the following structure in which a pendant group is introduced into Si and / or N of the main chain of polysilazane.

In a 2- to 6-functional polymer, a cyclic or cross-linked structure is formed on the polysilazane skeleton via a boron compound. In the cyclic structure, two functional groups in one molecule of the boron compound are polysilazane 1
It includes a structure condensed with two silicon atoms and / or nitrogen atoms in a molecule. A crosslinked structure occurs when two or more functional groups of a boron compound condense with two or more molecules of polysilazane.

Some of the 3 to 6 functional polymers have both the above-mentioned cyclic structure and crosslinked structure at the same time.

In the reaction of polysilazane with boron compound B (R ⁴ ) ₃ : L,
Since the complex-forming substance L does not react with polysilazane, the reaction mechanism and the structure of the product basically differ from polysilazane and B
(R ⁴ ) Same as reaction with ₃ .

The polysilazane used in the present invention has at least
Polysilazane having a Si—H bond or an N—H bond can be used, not only polysilazane alone, but also a copolymer of polysilazane and another polymer or a mixture of polysilazane and another compound.

The polysilazane used in the present invention includes a polysilazane having a chain, cyclic or cross-linked structure, or a polysilazane having a plurality of these structures in a molecule at the same time, and these can be used alone or in a mixture.

Representative examples of the polysilazane used in the present invention include the following, but are not limited thereto.

In general, R ¹ , R ² and R ³ in the general formula (I) are hydrogen, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and 5 to 7 carbon atoms. Cycloalkyl groups, aryl groups, or groups other than these groups represented by general formula (I)
A group in which the part directly connected to silicon or nitrogen in the group is carbon (eg, -CN, -COOH), an alkylsilyl group having 1 to 4 carbon atoms, an alkylamino group having 1 to 5 carbon atoms, a carbon atom It is preferable to select from the group consisting of the number 1 to 5 alkoxy groups because of small steric hindrance, and more preferably a hydrogen atom, methyl group, ethyl group, vinyl group, allyl group, methylamino group, ethylamino group, methoxy And ethoxy groups.

The compound of the formula (I) having a hydrogen atom at R ¹ , R ² and R ³ is perhydropolysilazane, and its production method is described, for example, in JP-A-60-145903, D. Seyferth et al.
ion of Am. Cer. Soc., C-13, January 1983. What is obtained by these methods is a mixture of polymers having various structures, but basically contains a chain portion and a cyclic portion in the molecule, Can be represented by the following chemical formula. An example of the structure of perhydropolysilazane is as follows.

A method for producing a polysilazane having a hydrogen atom for R ¹ and R ² and a methyl group for R ³ in the general formula (I) is described in D. Seyferth et al., Polym.
epr., Am, Chem. Soc., Div. Polym. Chem., 25 , 10 (1984). The polysilazane obtained by this method is a chain polymer or cyclic polymer having a repeating unit of SiH ₂ NCH ₃ , and neither has a crosslinked structure.

In the general formula (I), a method for producing a polyorgano (hydro) silazane having a hydrogen atom for R ¹ and R ³ and an organic group for R ² is described in D. Se.
yferth et al.Polym.Prepr., Am.Chem.Soc., Div.Polym.Chem.,
25 , 10 (1984), and JP-A-61-89230. The polysilazane obtained by these methods includes:
With R ² SiHNH as a repeating unit, the degree of polymerization is mainly 3
A chain structure and a ring structure in a molecule represented by the chemical formula of (R ² SiHNH) _X [(R ² SiH) _1.5 N] _1-X (0.4 <x <1) There is something.

In the general formula (I), a polysilazane having a hydrogen atom at R ¹ and an organic group at R ² and R ^3, and an organic group at R ¹ and R ² and a hydrogen atom at R ³ are represented by R ¹ R ² SiNR ³ . As a repeating unit, the degree of polymerization is mainly 3
-5 ring structures.

Next, among the polysilazanes used in the present invention, general formula (I)
Here are some typical examples.

Among polyorgano (hydro) silazanes, D. Seyfer
th et al. Communication of Am. Cer. Soc., C-132, July 1984.
Some have a cross-linked structure in the molecule as reported by K.K. An example is as follows.

Further, a polysilazane (R ¹ Si (NH) _x ) having a crosslinked structure obtained by ammonia decomposition of R ¹ SiX ₃ (X: halogen) as reported in JP-A-49-69717, or R ¹ polysilazane having the following structure obtained by copolymerization ammonolysis of SiX ₃ and R ² ₂ SiX ₂ also used as a starting material of the present invention Can be

The polysilazane used in the present invention has a main chain skeleton composed of the unit represented by the general formula (I) as described above.
The unit represented by the general formula (I) may be cyclized as is apparent from the above, in which case the cyclic portion serves as a terminal group. The terminus can be the same group as R ¹ , R ² , R ³ or hydrogen. As the polysilazane, in addition to those soluble in the organic solvent as described above, those insoluble in the organic solvent as shown in the following figure can be used as raw materials, but the reaction products with the boron alkoxide are insoluble in the organic solvent. Therefore, there are limitations in application.

The polysilazane used in the present invention has a number average molecular weight of about 100 to 50,000, and is composed of cyclic polysilazane, chain polysilazane, or a mixture thereof. Raw material polysilazane preferably used in the present invention,
Number average molecular weight about 250-20,000, more preferably about 500-1
It is 0,000. If the molecular weight is too small, the reaction product with the boron compound also has a low molecular weight, and because of its viscous liquid properties, not only is there a limitation in application, but also the amount of scattering during the firing process is large, and the ceramic yield is low. Not preferred. If the molecular weight is too large, the reaction product with the boron compound is likely to be insoluble in a solvent or gel, which is not preferable.

The boron compound used in the present invention is B (R ⁴ ) ₃ ... (II), B (R ⁴ ) ₃ : L (V), wherein R ⁴ and L are as defined above. ] The compound represented by any of the above.

As having a halogen atom as R ⁴ of B (R ⁴⁾ _3, fluoroborane, tribromoborane, trifluoroborane, trichloroborane, difluoromethyl borane, Jiiodoboran, Iodoboran, dibromomethyl borane, dichloromethyl borane, difluoromethyl borane , Difluoromethoxyborane, diiodomethylborane, ethynyldifluoroborane, difluorovinylborane, dibromoethylborane, dichloroethylborane, dichloroethoxyborane, ethyldifluoroborane, ethyldiiodoborane, bromodimethylborane, dibromo (dimethylamino) borane, Chlorodimethyl borane, chlorodimethoxy borane, fluorodimethyl borane, fluorodimethoxy borane, dichloroisopropyl borane, dichloropropyl borane, difluoro Lopoxyborane, bromo (dimethylamino) methylborane, chlorodivinylborane, dibromobutylborane, butyldichloroborane, butyldifluoroborane, butoxydifluoroborane, bromodiethylborane, dibromo (diethylamino) borane, chlorodiethylborane, chlorodiethoxyborane, dichloro ( (Pentafluorophenyl) borane, dichloro (diethylamino) borane, (diethylamino) difluoroborane, bromobis (dimethylamino) borane, chlorobis (dimethylamino) borane, bis (dimethylamino)
Fluoroborane, dibromophenylborane, dichlorophenylborane, difluorophenylborane, difluorophenoxyborane, diiodophenylborane, dibromo (1,3-dimethyl-1-butenyl) borane, dibromo (3,3-dimethyl-1-butenyl) borane , Dibromo (1-ethyl-1-butenyl) borane, dibromo-1-
Hexenylborane, dibromo (2-methylcyclopentyl) borane, 2-methylcyclopentyl-dichloroborane, dibromohexylborane, dibromo (2-methylpentyl) borane, difluorotoxylborane, dibromo (dipropylamino) borane, chlorodipropylborane, Chloro (1,1,2-trimethylpropyl) borane, dichloro (diisopropylamino) borane, butyl (dimethylamino) fluoroborane, dichloro (4-methylphenyl) borane, dichloro (methylphenylamino) borane, bromo (dimethylamino) Phenylborane, chloro (dimethylamino) phenylborane, 9-bromo-9
-Borabicyclo [3,3,1] nonane, 9-chloro-9-borabicyclo [3,3,1] nonane, diethylaminochloro-
(1-butenyloxy) borane, dichlorooctylborane, bromobis (1-methylpropyl) borane, bromodibutylborane, dibromo (dibutylamino) borane,
Chlorobis (2-methylpropyl) borane, dibutylchloroborane, dichloro (dibutylamino) borane, dibutylfluoroborane, bromobis (biethylamino) borane, chlorobis (diethylamino) borane, dichloro (2,4,6-trimethylphenyl) borane, 3 -Bromo-
7-methyl-3-borabicyclo [3,3,1] nonane, (diethylamino) chloro (cyclopentenyloxy) borane, dichloro (1,2,3,4,5-pentamethyl-2,4-cyclopentadiene-1) -Yl) borane, diiod (1,2,3,4,
5-pentamethyl-2,4-cyclopentagen-1-yl) borane, chlorodicyclopentyl balane, chloro (diethylamino) phenyl borane, bromodicyclopentyl borane, (1-butyl-1-hexenyl) dichloro borane, bromo dipentyl borane Chlorodiphenylborane, bromodiphenylborane, dichloro (diphenylamino) borane, chloro (diisopropylamino) phenylborane, chloro (dipropylamino) phenylborane, bromobis (2-bromo-1-hexenyl) borane, chlorobis (2-chloro -1-hexenyl) borane, chlorodicyclohexylborane, chlorodi-1-hexenylborane, chloro (1-ethyl-1-butenyl)
(1,1,2-trimethylpropyl) borane, chloro-1-
Hexenyl (1,1,2-trimethylpropyl) borane,
[Methyl (4-bromophenyl) amino] chloro (phenyl) borane, chloro (2-phenylethynyl) (1,1,
2-trimethylpropyl) borane, chloro (dibutylamino) phenylborane, chlorooctyl (1,1,2-trimethylpropyl) borane, chlorobis (dibutylamino) borane, fluorobis (2,4,6-trimethylphenyl) borane, (1-bromo-1-hexenyl) bis (2
-Methylpentyl) borane, (1-bromo-1-hexenyl) dihexylborane, bis (1-butyl-1-hexenyl) chloroborane, (5-chloro-1-pentenyl) bis (1,2-dimethylpropyl) borane, and so on.

Examples of those having an alkoxy group as R ⁴ include dihydroxymethoxyborane, dimethoxyborane, methoxydimethylborane, methyldimethoxyborane, trimethoxyborane, ethyldimethoxyborane, dimethylaminomethoxymethylborane, (dimethylamino) dimethoxyborane, and diethylmethoxy. Borane, dimethoxypropyl borane, bi (dimethylamino) methoxy borane, ethoxyethyl borane, butyl dimethoxy borane, diethoxyethyl borane, triethoxy borane, cyclopentyl dimethoxy borane, methoxy dipropyl borane, dimethoxy phenyl borane, (2-methylcyclopentyl) Dimethoxyborane, butoxydiethylborane, ethoxydipropylborane, hexyldimethoxyborane, 3-methoxy-3-borabicyclo [3,3,1] nonane, 9-methoxy-9-borabicyclo [3,3,1] nonane, dibutylmethoxyborane, methoxybis (1-methylpropyl) borane, methoxybis (2-methylpropyl) borane, propoxydipropyl Borane, triisopropoxy borane,
Tripropoxyborane, butoxydipropylborane, dibutylethoxyborane, diethyl (hexyloxy) borane, dibutoxyethylborane, di-tert-butoxyethylborane, dicyclopentylmethoxyborane, dibutylpropoxyborane, ethoxydipentylborane, (hexyloxy) Dipropylborane, tributoxyborane, tri-tert-butoxyborane, tris (2-butoxy) borane, tris (2-methylpropoxy) borane,
Methoxydiphenylborane, dicyclohexyl (methoxy) borane, dibutyl (2-penten-3-yloxy) borane, dibutoxypentylborane, ethoxydiphenylborane, (2-aminoethoxy) diphenoxyborane, dibutyl (1-cyclohexenyloxy) borane Butoxydipentylborane, dibutyl (hexyloxy) borane, dibutoxyhexylborane, dihexyloxypropylborane, tripentyloxyborane, butoxydiphenylborane, (2-methylpropoxy) diphenylborane, diphenoxyphenylborane, triphenoxyborane, triphenoxyborane Cyclohexyloxyborane, methoxybis (2,4,6-trimethylphenyl) borane, tribenzyloxyborane, tris (3-methylphenoxy) borane, trioctyl Okishiboran) Turin oxy borane, and the like trioctadecyl oxy borane.

As those having an alkenyl group as R ⁴ , ethynyl borane, vinyl borane, dihydroxy vinyl borane,
2-propenyl borane, ethynyl dimethoxy borane, methyl divinyl borane, trivinyl borane, 1-hexenyl dihydroxy borane, dimethoxy (3-methyl-1,
2-butenenyl) borane, diethyl-2-propenylborane, dihydroxy (2-phenylethenyl)
Borane, (diethylamino) diethynylborane, diethylaminodi-1-propynylborane, 2-butenyldiethylborane, diethyl (2-methyl-2-propenyl)
Borane, bis (dimethylamino) (1-methyl-2-propenyl) borane, 2-butenylbis (dimethylamino) borane, tri-2-propenylborane, tri (2-
Propenyloxy) borane, diethyl (3-ethyl-2)
-Butenyl) borane, 2-propenyldipropylborane, (diethylamino) di-1-propynylborane, butyldi-2-propenylborane, 2-butenyldipropylborane, diethyl (1-ethyl-2-butenyl) borane, ( 2-methyl-2-propenyl) dipropylborane, diethyl (1,1-dimethyl-3-buten-1-yloxy) borane, diethyl (1-hexen-4-yloxy) borane, 9- (2-propenyl)- 9-borabicyclo [3,3,1] nonane, dibutyl-2-propenylborane, (3-methyl-2-butenyl) dipropylborane,
9- (2-butenyl) -9-borabicyclo [3,3,1] nonane, tri-2-butenylborane, tris (2-methyl-2-propenyl) borane, hexyldi-2-propenylborane, 2-butenyldibutyl Borane, screw (1,2-
Dimethylpropyl) (2-phenylethenyl) borane,
Bis (1,2-dimethylpropyl) -1-octenylborane and the like can be mentioned.

Alkylamino group as R ^4, as having an amino group, amino-borane, Jiaminoboran, amino dimethylborane, (dimethylamino) borane, dimethyl (methylamino) borane, methyl bis (methylamino) borane,
Tris (methylamino) borane, (dimethylamino) dimethylborane, bis (dimethylamino) borane, bis (dimethylamino) methylborane, aminodipropylborane, (diethylamino) dimethylborane, (dimethylamino) diethylborane, tris (dimethylamino) ) Borane, isopropylbis (dimethylamino) borane, dimethyl (phenylamino) borane, bis (methylamino) phenylborane, bis (dimethylamino) -1-pyrrolylborane, aminodibutylborane, diethylborane, dimethylaminodipropylborane, Bis (dimethylamino) phenylborane, dibutyl (dimethylamino)
Borane, di-tert-butyl (dimethylamino) borane,
Dibutyl (diethylaminoborane, tris (diethylamino) borane, dimethylaminodiphenylborane, aminobis (2,4,6-trimethylphenyl) borane and the like can be mentioned.

As those having a hydroxyl group as R ⁴ , boric acid, hydroxyborane, dihydroxy (methyl) borane,
Hydroxydimethyl borane, ethyl dihydroxy borane, dihydroxy propyl borane, 2-furanyl dihydroxy borane, diethyl hydroxy borane, butyl dihydroxy borane, cyclopentyl dihydroxy borane, pentyl dihydroxy borane, (3 -Aminophenyl) dihydroxyborane, phenyldihydroxyborane, heptyldihydroxyborane, dihydroxy (2-phenylethyl) borane, dihydroxy (1-naphthalenyl)
Borane, hydroxybis (2,4,6-trimethylphenyl) borane, hydroxydiphenylborane and the like.

As those having an alkyl group as R ⁴ , methyl borane, dimethyl borane, ethyl borane, trimethyl borane, diethyl borane, ethyl dimethyl borane, diethyl methyl borane, 3-methyl-2-butyl borane, triethyl borane, (1,1,2-trimethyl Propyl) borane,
Dibutylborane, triisopropylborane, tripropylborane, bis (3-methyl-2-butyl) borane, bis (1,1,2-trimethylpropyl) borane, tri-tert
-Butyl borane, tributyl borane, tris (1-methylpropyl) borane, tris (2-methylpropyl) borane, tripentylborane, tris (1,2-dimethylpropyl) borane, trihexylborane, trioctylborane, and the like. Can be

As having a cycloalkyl group as R ^4, those having cyclopentyl Ruboran, cyclohexyl borane, dicyclohexyl borane, cyclohexyl (1,1,2-tri-methylpropyl) borane, tricyclopentyl Ruboran, an aryl group as tricyclohexyl borane R ^4, tri -1-naphthylborane, tris (2,4,6-trimethylphenyl) borane, tribenzylborane, tris (4-
Methylphenyl) borane, triphenylborane, phenylborane, ethyldiphenylborane and the like.

As a compound having a hydrogen atom as R ⁴ , borane can be mentioned.

As, 2,4,6-trichloroborazine, 2,4,6-tribromoborazine, 2,4,6-trifluoroborazine, borazine, 1-methylborazine, 2,4,6-trichloro-1,3, 5−
Trimethylborazine, 2,4,6-tribromo-1,3,5-trimethylborazine, 2,4,6-trifluoro-1,3,5-trimethylborazine, 1,3,5-trimethylborazine, 2,4 , 6-Trimethylborazine, 2,4,6-trimethoxyborazine, 2,4
-Dichloro-1,3,5,6-tetramethylborazine, 2-chloro-1,3,4,5-6-pentamethylborazine, 2,4,6-trichloro-1,3,5-triethylborazine, Hexamethyl borazine, 1,3,5-triethyl borazine, 2,4,6-triethyl borazine, 1,3,5-tripropyl borazine, 2,4,6-
Triethyl-1,3,5-trimethylborazine, 1,3,5-tributyl-2,4,6-trichloroborazine, hexaethylborazine, 2,4,6-trichloro-1,3,5-triphenylborazine, 2,4,6-triphenylborazine, 2,4,6-tri (diethylamino) borazine, 2,4,6-tri (bis (trimethylsilyl) amino) borazine, 2,4,6-tris (dimethylamino) 1 , 3,5-trimethylborazine, 1,3,5-trimethyl-2,4,6-triphenylborazine and the like.

B (R ⁴ ) ₃ : As L, borane-phosphine, borane-hydrazine, trifluoroborane-methal, cyanoborane-ammonia, difluoroborane-methylamine, borane-methylamine, tribromoborane-dimethylsaluside, trichloroborane -Dimethyl saluide,
Trifluoroborane-dimethyl ether, trifluoroborane-ethanol, borane-isocyanomethane, dibromoborane-dimethylsulfide, dichloroborane-
Dimethyl sulfide, trichloroborane-dimethylamine, trifluoroborane-ethylamine, cyanoborane-methylamine, bromoborane-dimethylsulfide, chloroborane-dimethylsulfide, difluoroborane-dimethylamine, iodoborane-dimethylsulfide-chloroborane-dimethylamine, borane-dimethylamine , Borane-dimethylphosphine, borane-dimethylsulfide, tribromoborane-trimethylphosphine, tribromoborane-trimethylamine, trichloroborane-trimethylamine, trichloroborane-trimethylphosphine, trifluoroborane-trimethylamine, trifluoroborane-trimethylphosphine Fin, triiodoborane-trimethylphosphine, cyanoborane Dimethylamine, difluoroborane-trimethylamine, bromoborane-trimethylphosphine, chloroborane-trimethylphosphine, fluoroborane-trimethylamine, iodoborane-trimethylamine, iodoborane-trimethylphosphine, borane-trimethylamine, trimethylborane-ammonia, trimethoxyborane-ammonia, Borane
Trimethylphosphite, borane-trimethylphosphine, trifluoroborane-2-methylimidazole, trifluoroborane-tetrahydrofuran, chloroborane-tetrahydrofuran, trichloroborane-diethylether, trifluoroborane-diethylether, dibromoborane-diethylether, dichloroborane -Diethyl ether, cyanoborane-trimethylamine, bromoborane-diethylether, dibromoborane-trimethylamine, dibromomethylborane-trimethylphosphine, chloroborane-dithietherether, borane-tert-butylamine, borane-diethylamine,
Tribromoborane-pyridine, trichloroborane-pyribine, trifluoroborane-pyridine, borane-pyridine, borane-4-aminopyridine, bromodimethylborane-trimethylphosphine, dichlorocyanoborane-
Pyridine, trifluoroborane-phenol, cyanoborane-pyridine, dibromomethylborane-pyridine, borane-4-methylpyridine, trifluoroborane-1-
Hexanol, tribromoborane-triethylamine,
Trichloroborane-triethylamine, chloroborane-
Triethylamine, borane-triethylamine, trimethylborane-trimethylamine, borane-tris (dimethylamino) phosphine, trifluoroborane-methoxybenzene, trifluoroborane-4-methylaniline, borane-2,6-dimethylpyridine, trifluborane-dibutyl ether Phenyldichloroborane-triethylamine, tribromoborane-triphenylphosphine, trichloroborane-triphenylphosphine,
Trifluoroborane-triphenylphosphine, borane-triphenylamine, borane-triphenylphosphine, trimethylborane-triphenylamine, triphenylborane-trimethylamine, triphenylborane-pyridine, triphenylborane-triethylamine, and the like. be able to. In addition to the above substances, tetraborane (10), pentaborane (9), pentaborane (11), hexaborane (10), hexaborane (12), octaborane (12), octaborane (18), isononaborane (15), nonaborane (15) , Decaborane (14), 1,
1'-bipentaborane (9), 1,2'-bipentaborane (9), 2,2'-bipentaborane (9), 1-carbahexaborane (7), 2-carbahexaborane (9),
2-dicarbahexaborane (6), 1,2-dicarbapentaborane (7), 2,4-dicarbaheptaborane (7), 2,3
-Dicarbahexaborane (8), 1,7-dicarbaoctaborane (8), 1,2-dicarbadodecaborane (12), 1,7
Good results can also be obtained using -dicarbadodecaborane (12) and 1,12-dicarbadodecaborane (12).

Most of these boron compounds are on the market,
Even those that have not been put on the market can be manufactured in the same manner as those put on the market.

The number average molecular weight of the novel polyborosilazane of the present invention is 200
50500,000, preferably 800800200,000.

The present invention also relates to a method for producing the above-mentioned novel polyborosilazane, which is mainly composed of the general formula (I): (Wherein R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a moiety other than these groups that is directly connected to silicon or nitrogen in the formula; Represents a carbon group, an alkylsilyl group, an alkylamino group, or an alkoxy group, provided that R ¹ , R ² , R ³
At least one is a hydrogen atom. ) Having a main skeleton consisting of units represented by
100,000 to 500,000 polysilazane, and formula (II), (IV) or (V): B (R ⁴ ) ₃ (II) B (R ⁴ ) ₃ : L (V) (In these formulas, R ⁴ may be the same or different and include a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group, An alkyl group, an aryl group, an alkoxy group, an alkylamino group, a hydroxyl group or an amino group, and L is a compound that forms a complex with B (R ⁴ ) _3. ) To obtain a polyborosilazane having a number average molecular weight of 800 to 500,000 from a boron / silicon atom ratio in the range of 0.01 to 3.

The polysilazane used in the present invention is not particularly limited, and any available polysilazane can be used. However, in terms of reactivity with a boron compound, R ¹ , R ² , and R ³ in the formula (I) have steric hindrance. Small groups are preferred. That, R ^1, preferably an alkyl group having a hydrogen atom and _C 1 _{~ 5} as R ² and R ^3, more preferably an alkyl group having a hydrogen atom and _C 1 _{~ 2.}

The boron compound used in the present invention is not particularly limited,
In terms of reactivity, the formula (II) ~ R ⁴ is preferably an alkyl group and alkoxy group of hydrogen atoms and halogen atoms and C ₁ ~ ₂₀ in (V), hydrogen atom and halogen atoms and C ₁
Alkyl groups and alkoxy groups of from ₁₀ to ₁₀ are more preferred,
Alkyl and alkoxy groups of hydrogen atoms and halogen atoms and C ₁ ~ ₄ are most preferred. The general formula includes the formula (II)
R ⁴ to (V) are a hydrogen atom, a halogen atom, a carbon atom 1
It is preferably selected from an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 1 to 10 carbon atoms, and a methyl group, an ethyl group, an n-propyl group, i
-Propyl group, n-butyl group, i-butyl group, t-butyl group, phenyl group, benzyl group, tolyl group, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i More preferably, it is selected from a -butoxy group, a t-butoxy group, and a phenoxy group. The mixing ratio between the polysilazane and the boron compound is added so that the M / Si atomic ratio is 0.001 to 60, preferably 0.01 to 5, and more preferably 0.05 to 2.5. If the addition amount of the boron compound is larger than this, the boron compound is simply recovered without reacting without increasing the reactivity with the polysilazane, and if the addition amount is small, significant increase in the molecular weight does not occur.

The reaction can be carried out without a solvent, but it is more difficult to control the reaction than when an organic solvent is used, and a gel-like substance may be formed. Therefore, it is generally preferable to use an organic solvent. As the solvent, aromatic hydrocarbon, aliphatic hydrocarbon,
Alicyclic hydrocarbon solvents, halogenated hydrocarbons,
Aliphatic ethers and alicyclic ethers can be used. Preferred solvents, methylene chloride, chloroform, carbon tetrachloride,
Bromoform, ethylene chloride, ethyl chloride, trichloroethane, halogenated hydrocarbons such as tetrachloroethane, ethyl ether, isopropyl ether, ethyl butyl ether, butyl ether, 1,2-dioxyethane, dioxane, dimethyl dioxane, ethers such as tetrahydrofuran, tetrahydropyran, Pentane,
Hexane, isohexane, methylpentane, heptane,
Hydrocarbons such as isoheptane, octane, isooctane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene and the like.

In order to obtain a high molecular weight polyborosilazane, it is preferable to carry out the reaction between the polysilazane and the boron compound under basic conditions. In this case, the basic condition means that a basic compound, for example, a tertiary amine, a secondary amine having a sterically hindered group, phosphine or the like coexists in the reaction system. Such basic conditions can be formed by adding a basic compound to a reaction solvent, or by using a basic solvent or a mixture of a basic solvent and the non-basic solvent as a reaction solvent. be able to. The amount of the basic compound added is at least 5 parts by weight, preferably at least 20 parts by weight, per 100 parts by weight of the reaction solvent. When the addition amount of the basic compound is less than this,
The effect of remarkably increasing the molecular weight is lost.

Any basic solvent can be used as long as it does not decompose the starting materials polysilazane and boron compound. Such include, for example, trialkylamines such as trimethylamine, dimethylethylamine, diethylmethylamine and triethylamine;
In addition to tertiary amines such as pyridine, picoline, dimethylaniline, pyrazine, pyrimidine, pyridazine and derivatives thereof, pyrrole, 3-pyrroline, pyrazole,
-Pyrazolyl, and mixtures thereof.

The reaction temperature is preferably in a range where the reaction system is a liquid system. In order to further increase the molecular weight of polyborosilazane, the reaction can be carried out at a temperature higher than the boiling point of the solvent.
The temperature is preferably 0 ° C. or lower, preferably −78 ° C. to 300 ° C.

The pressure is preferably normal pressure. Pressurization is not particularly limited, but under reduced pressure, low-boiling components are distilled off and the yield is undesirably reduced. The reaction time is generally about 30 minutes to one day, but it is preferable to extend the reaction time in order to further increase the molecular weight of polyborosilazane.

The reaction atmosphere is preferably a dried inert atmosphere such as dry nitrogen or dry argon to prevent oxidation or hydrolysis of the raw material boron compound and polysilazane or the product polyborosilazane.

The reaction of the present invention is advantageous in that an expensive catalyst such as a noble metal is not required.

The product polyborosilazane and the starting boron compound can be separated by distillation under reduced pressure of the boron compound, gel permeation chromatography, or high performance liquid chromatography.

The novel polyborosilazane obtained by the method of the present invention is obtained by condensing a part of the silicon-hydrogen bond of the polysilazane with a hydrogen atom or a halogen atom of a boron compound or an organic group, and newly forming a silicon- (oxygen) -boron bond or a silicon-hydrogen bond. A polymer having a structure in which a nitrogen-boron bond is formed and / or a part of the nitrogen-hydrogen bond of polysilazane is condensed with a boron compound. The novel polyborosilazane of the present invention uses polysilazane having a number average molecular weight of 100 to 50,000 as a raw material as described above, and a boron compound residue, Since the polymer is formed by forming a crosslinked polymer by bonding or polymerizing by introducing a pendant group, its molecular weight is naturally higher than that of the raw material polysilazane. Generally, the novel polyborosilazane for the purpose of the present invention has a number average molecular weight of 200 to 500,0.
00, preferably 800-200,000. In the case of the polyborosilazane according to the present invention, the ratio of boron atoms to silicon atoms in the polyborosilazane is in the range of 0.01 or more and 3 or less, and is soluble in an organic solvent.

The obtained polyborosilazane has a higher cross-linking structure and molecular weight than the raw material polysilazane, so that the solidification property is improved,
Immediate shaping is possible at room temperature. In addition, the high molecular weight reduces evaporation loss during high-temperature firing, and improves the ceramic yield. For example, according to the polyborosilazane of the present invention, a ceramic yield of 70% or more, and even 80% or more, can be obtained.

The polyborosilazane of the present invention can be easily converted to ceramics by firing in a gas atmosphere or in a vacuum. Nitrogen is convenient as the atmospheric gas, but argon and ammonia can also be used. Further, a mixed gas of nitrogen, ammonia, argon, hydrogen and the like can be used.

The firing temperature is generally in the range of 700 to 1900 ° C. If the firing temperature is too low, it takes a long time for firing, and if it is too high, it is disadvantageous in terms of energy cost.

The heating rate is generally in the range of 0.1 ° C./min to 300 ° C./min. If the heating rate is too slow, it takes a long time for firing, or if it is too slow, thermal decomposition and shrinkage occur at once, causing cracks in the ceramics. Good results can be obtained by controlling the heating rate to 0.5 ° C./min to 50 ° C./min in a temperature range of 600 ° C. or less where the thermal decomposition of polyborosilazane mainly occurs.

The polymetallosilazanes disclosed by the present inventors generally have the characteristic that when fired, an amorphous ceramic is obtained, and the high-temperature strength such as the elastic modulus is excellent. For example, 1200
Even when the temperature is maintained at about 1 to about 1300 ° C. for about 1 hour, the amorphous state is maintained. However, the ceramics obtained by firing the polyborosilazane provided by the present invention are further excellent in heat resistance, and a remarkable property that they are still amorphous even when heated at 1500 ° C or more, preferably 1700 ° C or more. Is shown. Generally, a polycrystalline material has a lower mechanical strength than an amorphous material because a grain boundary serves as a fracture source. Ceramics obtained by firing the polyborosilazane provided by the present invention, 1700
It has excellent high-temperature mechanical strength because it is amorphous even at ℃. The fact that amorphous at 1700 ° C. is theoretically considered to be almost the highest value in the Si-N system, and considering that the temperature of 1700 ° C. is close to the upper limit of the heat resistance even in the crystalline Si-N system. It can be seen that this effect is extremely excellent.

〔The invention's effect〕

The provision of the polyborosilazane of the present invention has the following effects.

(1) It is known that ceramics obtained from metallosilazane into which Al, Ti, and Zr are introduced have improved heat resistance as compared with ceramics obtained from raw material polysilazane. The metal has higher heat resistance than that of the metal and can improve the high-temperature mechanical strength.

(2) Polyborosilazane is soluble in an organic solvent and is converted into Si-NB ceramics after firing, so that a high-performance composite ceramic molded body can be obtained.

(3) Boron coexists in ceramics obtained by firing polyborosilazane, so that the hardness of the ceramics can be improved.

(4) Since the composition of the ceramics can be controlled, the conductivity of the ceramics can be selected from a wide range.

〔Example〕

Reference Example 1 A four-necked flask having an internal volume of 1 was equipped with a gas blow-in tube, a mechanical stirrer, and a dewar condenser.
After the inside of the reactor was replaced with deoxygenated dry nitrogen, 490 ml of degassed dry pyridine was placed in a four-necked flask, and cooled with ice. Then, when 51.6 g of dichlorosilane was added, a white solid adduct (SiH ₂ Cl ₂ .2C ₅ H ₅ N) was formed. The reaction mixture was ice-cooled, and while stirring, 51.0 g of purified ammonia was blown through a sodium hydroxide tube and an activated carbon tube.

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

The number average molecular weight of the obtained polymer was 980 as measured by GPC. When the IR (infrared absorption) spectrum (solvent: dry o-xylene; concentration of perhydropolysilazane: 10.2 g / l) of this polymer is examined, the wave number (cm ⁻¹ ) is 3350 (apparent absorption coefficient ε = 0.557). The absorption based on NH of lg ^-1 cm ^-1 and 1175; the absorption based on SiH of 2170 (ε = 3.14); the absorption based on SiH and SiNSi of 1020 to 820 were confirmed to be ¹ H NMR. (Proton nuclear magnetic resonance) spectrum (60 MHz solvent CDCl ₃ / reference material TM)
Examination of S) confirmed that all showed broad absorption. That is, δ 4.8 and 4.4 (br, SiH); 1.5 (b
(r, NH) was confirmed.

Reference Example 2 A reaction was carried out using the same apparatus as in Reference Example 1. That is,
450 ml of degassed dry tetrahydrofuran was placed in the four-necked flask shown in Reference Example 1, and cooled in a dry ice-methanol bath. Next, 46.2 g of dichlorosilane was added. The solution is cooled and stirred with anhydrous methylamine.
44.2 g was blown as a mixed gas with nitrogen.

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

Reference Example 3 A four-necked flask having an internal volume of 1 was equipped with a gas blowing tube, a mechanical stirrer, and a dewar condenser. After the inside of the reactor was replaced with deoxygenated dry nitrogen, 300 ml of dry dichloromethane and 24.3 g (0.211 mol) of methyldichlorosilane were placed in a four-necked flask and cooled with ice. While stirring, 18.1 g (1.06 mol) of purified ammonia was blown through a sodium hydroxide tube and an activated carbon tube.

After completion of the reaction, the reaction mixture was centrifuged, washed with dry dichloromethane, and further filtered under a nitrogen atmosphere.
The solvent was distilled off from the filtrate under reduced pressure to obtain 8.81 g of colorless and transparent methyl (hydro) silazane. The number average molecular weight of this product was 380 as measured by GPC.

Reference Example 4 A reaction was carried out using the same apparatus as in Reference Example 1. That is, 500 ml of degassed dry toluene was put into the four-necked flask shown in Reference Example 1, and this was cooled with ice. Next, 52.1 g of phenyldichlorosilane was added. The solution was cooled, and while stirring, 30.0 g of purified ammonia was blown through a sodium hydroxide tube and an activated carbon tube as a mixed gas with nitrogen.

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

Example 1 A pyridine solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane; 5.10% by weight) 1
00 ml was placed in a pressure-resistant reaction vessel having an internal volume of 300 ml, and 4.0 cc (0.035 mol) of trimethyl borate was added, and the reaction was carried out while stirring at 160 ° C. for 3 hours in a closed system. 1.0k before and after reaction
g / cm ² . The generated gas was hydrogen and methane by gas chromatography (GC) measurement. After cooling to room temperature, 100 ml of dry φ-xylene was added, and the pressure was 3 to 5 mm
After removing the solvent at Hg and a temperature of 50 to 70 ° C., 5.45 g of a white powder was obtained. This powder was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents.

The number average molecular weight of the polymer powder was 2,100 as measured by GPC. In addition, as a result of analyzing the IR spectrum, absorptions based on NH at wave numbers (cm ⁻¹ ) of 3350 and 1175; absorptions based on SiH of 2170; SiH and SiNSi of 1020 to 820
Absorption based on CH; 2960, 2940, 2840 absorption based on CH; 1090
Absorption based on SiO; confirmed to exhibit an absorption based on BO of 1500-1300. Further analysis of the ¹ H NMR spectrum (CDCl ₃ , TMS) of the polymer powder indicated that δ 4.8 (Br, Si
H ₂ ), δ 4.7 (br, OSiH ₂ ), δ 4.4 (br, SiH ₃ ), δ 3.6
(Br, CH ₃ O) and δ1.4 (br, NH) absorption were observed. The results of elemental analysis of the polymer were as follows: Si: 42.4%, N: 25.9%, C: 8.8%, O: 12.7%, B: 7.0%, H: 3.8% on a weight basis.

Example 2 100 ml of a φ-xylene solution of methylpolysilazane obtained in Reference Example 2 (concentration of methylpolysilazane; 10.4% by weight)
Into a pressure-resistant reaction vessel having an internal volume of 300 ml, and boron trichloride 17.
3 g (0.283 mol) was added, and the reaction was carried out while stirring at 20 ° C. for 3 hours in a closed system. The white precipitate was separated by filtration, and the solvent of the filtrate was distilled off under reduced pressure in the same manner as in Example 1 to obtain 8.2 g of a colorless and transparent rubbery solid. The number average molecular weight of this substance was 1,440 as measured by GPC.

Example 3 10 ml of a solution of perhydropolysilazane in φ-xylene (concentration of perhydropolysilazane; 5.84% by weight) obtained in Example 1 was placed in a pressure-resistant reaction vessel having an internal volume of 300 ml, and 4.0 cc of pyridine-borane complex (0.0396 mol) was added. ) And add 80 in a closed system
The reaction was carried out with stirring at ℃ for 3 hours. The pressure increased 0.2 kg / cm ² before and after the reaction. The generated gas was hydrogen by GC measurement. The solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 4.98 g of a reddish brown solid. The number average molecular weight of this material was 170,000 as measured by GPC.

Example 4 100 ml of a solution of N-methylsilazane in γ-picoline obtained in Reference Example 3 (concentration of N-methylsilazane; 4.95% by weight)
Was placed in a pressure-resistant reaction vessel having an internal volume of 300 ml, 4.0 cc (0.0148 mol) of tributyl borate was added, and the reaction was carried out while stirring at 120 ° C. for 3 hours in a closed system. 0.8k pressure before and after reaction
g / cm ² . After cooling to room temperature, the solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 5.03 g of a pale yellow rubbery solid. The number average molecular weight of this substance was 1880 as measured by GPC.

Example 5 80 ml of a pyridine solution of phenylpolysilazane obtained in Reference Example 4 (phenylpolysilazane concentration; 3.65% by weight)
Into a pressure-resistant reaction vessel having an internal volume of 300 ml, and 1.26 g of boric acid (0.
The reaction was carried out while stirring at 60 ° for 1 hour in a closed system. The pressure increased by 0.6 kg / cm ² before and after the reaction. After cooling to room temperature, the solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 2.46 g of a white solid. The number average molecular weight of this substance was 3.2040 as measured by GPC.

Example 6 A pyridine solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane; 5.37% by weight) 1
00 ml was placed in a pressure-resistant reaction vessel having an internal volume of 300 ml, and 3.2 ml (0.0376 mol) of 1,3,5-trimethylborazine was added.
The reaction was carried out with stirring at 0 ° C. for 3 hours. The pressure rose 0.3 kgcm ² before and after the reaction. The generated gas was hydrogen by GC measurement. After cooling to room temperature, the solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 4.86 g of a white powder. This powder was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents. The number average molecular weight of this polymer powder was 243 as measured by GPC.
It was 0.

Example 7 A pyridine solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane; 6.32% by weight) 1
00 ml was placed in a pressure-resistant reaction vessel having an internal volume of 300 ml, and 5.5 ml (0.0379 mol) of trimethoxyboroxine was added.
The reaction was carried out with stirring at ℃ for 3 hours. The pressure increased 0.2 kg / cm ² before and after the reaction. The generated gas was hydrogen and methane by GC measurement. After cooling to room temperature, the solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 5.77 g of a white powder. This powder was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents. The number average molecular weight of this polymer powder was 1940 as measured by GPC.

Example 8 The polyborosilazane obtained in Example 1 was heated to 1000 ° C. in ammonia at a heating rate of 3 ° C./min, and thermally decomposed to obtain a white solid in a yield of 88.0% by weight. X-ray powder diffraction measurement of the obtained ceramic confirmed that it was amorphous. The elemental analysis of this solid
On a weight basis, Si: 40.7%, N: 33.5%, C: 1.57%, O: 12.0%, B: 7.00%.

Next, the solid was further heated in nitrogen to 1700 ° C. at a heating rate of 10
The mixture was calcined by heating at a rate of ° C./min to obtain a gray solid. When the powder was subjected to powder X-ray diffraction measurement, it was confirmed that the material was kept in an amorphous state as shown in FIG.

Example 9 The polyborosilazane obtained in Example 3 was heated to 1000 ° C. in ammonia at a heating rate of 3 ° C./min, and thermally decomposed to obtain a pale brown solid in a yield of 82.0% by weight. . X-ray powder diffraction measurement of the obtained ceramic confirmed that it was amorphous. The results of elemental analysis of this solid were as follows: Si: 43.5%, N: 38.7%, C: 0.70%, O: 8.40%, B: 5.60% on a weight basis.

Next, the solid was heated and fired in nitrogen at 1500 ° C. at a rate of temperature increase of 10 ° C./min to obtain a black-gray solid. The powder was subjected to powder X-ray diffraction measurement. As shown in FIG. 2, it was confirmed that the material was kept in an amorphous state.

Next, the solid was further heated to 1700 ° C in nitrogen.
Heating and baking at 10 ° C./min gave a black-grey solid. The powder was subjected to powder X-ray diffraction measurement. As shown in FIG. 3, the (101) diffraction line of α-Si ₃ N ₄ was obtained at 2θ = 20.5 °, and 2θ = 20.5 °.
(110) diffraction line of α-Si ₃ N ₄ at 22.9 °, α at 2θ = 26.4 °
-Si ₃ N ₄ in (200) diffraction line, 2θ = 30.9 ° to the _{α-Si 3 N 4 (201} ) diffraction line, 2θ = 31.7 ° to the _{α-Si 3 N 4 (002} ) diffraction line, 2 [Theta] = (102) diffraction line of α-Si ₃ N ₄ at 34.5 °, 2θ
= 35.2 ° to the _{α-Si 3 N 4 (210} ) diffraction line, 2θ = 38.8 ° to the _{α-Si 3 N 4 (211} ) diffraction line, 2θ = 39.4 ° to the α-Si ₃ N ₄
(112) diffraction line of α-Si ₃ N ₄ at 2θ = 40.1 ° (300)
Diffraction line, (202) diffraction line of α-Si ₃ N ₄ at 2θ = 41.8 °, 2
(301) diffraction line of α-Si ₃ N ₄ at θ = 43.4 °, 2θ = 46.9 °
The α-Si ₃ N ₄ in (220) diffraction line, 2θ = 48.2 ° to the α-Si ₃ N
₄ (212) diffraction line, 2θ = 48.8 ° to α-Si ₃ N ₄ (310)
Diffraction line, β-Si ₃ N ₄ (110) diffraction line at 2θ = 23.3 °, (200) diffraction line of β-Si ₃ N ₄ at 2θ = 26.9 °, 2θ
= 33.6 ° in the _{β-Si 3 N 4 (101} ) diffraction line, 2θ = 36.0 ° in the _{β-Si 3 N 4 (210} ) diffraction line, 2θ = 41.4 ° to β-Si ₃ N ₄
(201) diffraction line of β-Si ₃ N ₄ at 2θ = 49.9 ° (310)
Diffraction lines were observed, confirming that it was crystalline silicon nitride.

Example 10 100 mL of a solution of perhydropolysilazane obtained in Reference Example 1 in φ-xylene (concentration of perhydropolysilazane; 4.53% by weight) was placed in a 300 mL pressure-resistant reaction vessel, and 3.34 g of a borane-dimethylsulfide complex (0.044 g) was added. Mol) was added slowly, and the reaction was carried out while stirring at 20 ° C. for 3 hours in a closed system. The pressure increased by 1.2 kg / cm ² before and after the reaction. The gas generated was hydrogen as determined by gas chromatography (GC). After removing the solvent at a pressure of 3 to 5 mmHg and a temperature of 50 to 70 ° C., 4.15 g of a white powder was obtained. This powder was soluble in toluene, tetrahydrofuran, chloroform and other organic solvents. The number average molecular weight of the polymer powder was 4,400 as measured by GPC. As a result of analyzing the IR spectrum, the wave number (cm ⁻¹ ) of 3350
And 1175 based on NH; 2170 based on SiH; 102
Absorption based on SiH and SiNSi from 0 to 820; confirmed to exhibit absorption based on BN from 1500 to 1300. Further analysis of the ¹ H NMR spectrum (CDCl ₃ , TMS) of the polymer powder indicated that δ 4.8 (br, SiH ₂ ), δ 4.4 (br, SiH ₃ , δ 1.4 (br, N
H) absorption was observed.

The polymer powder was heated to 1000 ° C. in ammonia at a heating rate of 5 ° C./min, and thermally decomposed to obtain a gray solid in a yield of 83.0% by weight. When the obtained ceramic was subjected to powder X-ray diffraction measurement, it was confirmed that the ceramic was amorphous.

Next, the solid was further heated to 1700 ° C in nitrogen.
Heating and baking at 10 ° C./min gave a black-grey solid. When the powder was subjected to powder X-ray diffraction measurement, it was confirmed that the substance was kept in an amorphous state. Elemental analysis results of this substance were as follows: Si: 47.5%, N: 36.8%, C: 1.30%, O: 2.23%, B: 11.4%.

Comparative Example 1 A condenser, a seal cap, a thermometer, and a magnetic stirrer were placed in a four-necked flask having an inner volume of 100 ml. After the inside of the reactor was replaced with dry nitrogen, the benzene solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane: 4.4) was placed in a four-necked flask.
63.4 g of 5 wt%), and 4.00 g (12.2 mmol) of zirconium tetraisopropoxide was added to dry benzene with stirring.
The solution dissolved in 6.0 ml was added using a syringe and reacted while refluxing.

After the completion of the reaction, the reaction solution was subjected to GPC fractionation, whereby polyhydroszirconosilazane was obtained as a pale yellow solid.

The number average molecular weight of the produced polymer was 2,100 as measured by a freezing point depression method (solvent: dry benzene). As a result of elemental analysis, the polymer was found to be Si: 34.0, Zr: 18.6,
It had a composition of N: 13.0, O: 13.2, C: 14.4 and H: 5.1 (% by weight each).

When the polymer obtained here was fired at 1350 ° C. under a nitrogen atmosphere, a black solid was obtained in a yield of 78% by weight. As a result of X-ray powder diffraction measurement of this substance, as shown in FIG. 4, a diffraction line of an amorphous ZrO ₂ phase was observed. When perhydropolysilazane is calcined under the same conditions, formation of crystalline silicon nitride is confirmed by X-rays. However, when polyhydrozirconosilazane is used as a precursor, amorphous ZrO ₂ phase is formed to produce silicon nitride. Is maintained at a higher temperature.

Comparative Example 2 A condenser, a seal cap, a thermometer, and a magnetic stirrer were installed in a four-necked flask having an inner volume of 200 ml. After the inside of the reactor was replaced with dry nitrogen, 110 g of the benzene solution of perhydropolysilazane (concentration of perhydropolysilazane: 4.57% by weight) obtained in Reference Example 1 was placed in a four-necked flask, and titanium tetraisopropoxy was stirred. A solution obtained by dissolving 6.30 g (22.2 mmol) of benzene in 6.5 ml of dry benzene was added using a syringe. The reaction solution changed from colorless to light brown, purple, and black. After completion of the reaction, the solvent was distilled off under reduced pressure to obtain polyhydrotitanosilazane as a dark brown solid. The yield was 84.0% by weight.

The number average molecular weight of the produced polymer was 1,840 as measured by freezing point depression method (solvent: dry benzene). The polymer obtained here is not simply a mixture of perhydropolysilazane and titanium alkoxide, but a polymer having a high molecular weight by a condensation reaction of both substances.

As a result of elemental analysis of the obtained polymer, the polymer was identified as S
i: 33.0, Ti: 9.8, N: 14.0, O: 11.8, C: 23.4 and H: 6.6 (each by weight).

When the obtained polymer was calcined at 1350 ° C. for 1 hour under a nitrogen atmosphere, a black solid was obtained in a yield of 72% by weight. When X-ray powder diffraction measurement was performed on this substance, as shown in FIG. 5, only a diffraction line of an amorphous TiN phase was observed. When perhydropolysilazane is fired under the same conditions, formation of crystalline nitrogen silicon has been confirmed X-ray. However, when polyhydrotitanium nosilazane is used as a precursor, an amorphous TiN phase is formed, thereby producing silicon nitride. The amorphous state is maintained up to higher temperatures.

The elemental analysis result (% by weight) of the obtained ceramics is S
i: 41.3, Ti: 12.9, N: 20.5, O: 19.9, C: 4.5.

Comparative Example 3 A pyridine solution of perhydropolysilazane obtained in Reference Example 1 (perhydropolysilazane concentration: 5.25% by weight) 1
The mixture was placed in a 20 ml pressure-resistant reaction vessel having an internal volume of 300 ml, 13.0 g (mol) of aluminum triisopropoxide was added, and the reaction was carried out with stirring at 120 ° C. for 3 hours in a closed system. The pressure increased 1.8 kg / cm ² before and after the reaction. After cooling to room temperature, the solvent was distilled off under reduced pressure in the same manner as in Example 1 to obtain 12.3 g of a pale yellow solid.
Obtained.

The obtained polymer was heated to 1500 ° C. at 10 ° C./min in nitrogen and thermally decomposed to obtain an off-white solid in a yield of 69.8% by weight. A powder X-ray diffraction measurement of this material showed that the (100) diffraction line of β-Sialon at 2θ = 13.3 ° and the (110) diffraction line of β-Sialon at 2θ = 23.1 °, 2θ
= 26.8 ° at (200) diffraction line of β-Sialon, 2θ = 33.2 °
Β-Sialon (101) diffraction line, β = Siaon at 2θ = 35.8 °
lon (210) diffraction line, 2θ = 38.4 ° to β-Sialon (11
1) Diffraction line, β-Sialon (201) diffraction line at 2θ = 40.8 °, β-Sialon (220) and (211) diffraction lines at 2θ = 47.5 °, β-Sialon (310) at 2θ = 49.5 ° ) Diffraction line, 2θ
= (301) diffraction line of β-Sialon at 51.6 °, 2θ = 57.2 °
(221) diffraction line of β-Sialon at 2θ = 59.1 ° β-Sia
The (311) diffraction line of lon was observed, and it was confirmed to be crystalline β-Sialon. Elemental analysis results of the obtained ceramics were: Si: 38.9, N: 25.8, Al: 21.9%, C: 3.2%, O: 12.3% on a weight basis.

[Brief description of the drawings]

1 to 3 are powder X-ray diffraction patterns of ceramics obtained by firing polyborosilazane, and FIGS. 4 and 5 are X-ray powder diffraction patterns of ceramics obtained by firing polyzirconosilazane and polytitanosilazane.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Tashiro 1-3-1 Nishitsurugaoka, Oi-machi, Irima-gun, Saitama Prefecture Within Toa Fuel Industry Co., Ltd. (72) Inventor Takeshi Isoda Oimachi, Iruma-gun, Saitama 1-3-1, Nishitsurugaoka, Research Institute of Toa Fuel Industry Co., Ltd. (72) Inventor Kiyoshi Sato 1-3-1, Nishitsurugaoka, Oimachi, Iruma-gun, Saitama Prefecture Research Institute of Toa Fuel Industry Co., Ltd. (56) References JP-A-53-50299 (JP, A) JP-A-1-252638 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 77/62

Claims (2)

(57) [Claims] 1. A compound represented by the general formula (I): (Wherein, R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group,
Or a group other than these groups in which the portion directly connected to silicon or nitrogen in the formula is carbon, an alkylsilyl group, an alkylamino group, or an alkoxy group. However, at least one of R ¹ , R ² and R ³ is a hydrogen atom. And a part of silicon and / or part of nitrogen constituting the main skeleton represented by the following general formula (i), (ii), (iii) or (iv): A) a polyborosilazane having a B / Si atomic ratio in the range of 0.01 to 3 and a number average molecular weight of 800 to 500,000. (Wherein, R ⁶ is a hydrogen atom, a halogen atom, a carbon atom having 1 to 1)
Having 20 alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, alkoxy groups, alkylamino groups,
A hydroxyl group or an amino group, R ⁷ is a residue bonded to the nitrogen atom of the group having a nitrogen atom in R ⁶ , and is represented by the formula (i
In v), at least two of a total of six atoms, each consisting of three nitrogen atoms and boron atoms, are used for crosslinking, and R ⁶ can be bonded to the remaining atoms. ) 2. A compound of the general formula (I): (Wherein, R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group,
Or a group other than these groups in which the portion directly connected to silicon or nitrogen in the formula is carbon, an alkylsilyl group, an alkylamino group, or an alkoxy group. However, at least one of R ¹ , R ² and R ³ is a hydrogen atom. ) Having a main skeleton consisting of units represented by
100 to 50,000 polysilazanes and the general formula (II), (IV) or (V): B (R ⁴ ) ₃ (II) B (R ⁴ ) ₃ : L (V) (In these formulas, R ⁴ may be the same or different and include a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group, An alkyl group, an aryl group, an alkoxy group, an alkylamino group, a hydroxyl group or an amino group, and L is a compound that forms a complex with B (R ⁴ ) _3. ) A boron / silicon atom ratio in the range of 0.01 to 3 and a number average molecular weight of 800 to 500,000 to obtain a polyborosilazane.