JPH0798866B2 - Ceramics manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing ceramics using an organic silazane polymer used as a ceramics precursor.

[0002]

2. Description of the Related Art Ceramics have attracted attention as materials excellent in heat resistance, wear resistance, high temperature strength, etc. However, since they are hard and brittle, it is difficult to process them. It's extremely difficult. Therefore, when manufacturing a ceramic product, a method of forming fine powder of a ceramic material into a desired shape in advance by a method such as pressing and then sintering, or melting or dissolving an organic polymer as a ceramic precursor in a solvent Then, a precursor method or the like is employed in which the material is processed into a desired shape and then fired to be inorganic. The most significant feature of the precursor method is that a ceramic product having a shape that cannot be obtained by the sintering method using fine powder can be obtained, and thus a product having a special shape such as a fiber or a sheet can be manufactured.

In this case, among those generally called ceramics, SiC and Si ₃ N ₄ are excellent in high temperature such that SiC is excellent in heat resistance and high temperature strength, and Si ₃ N ₄ is excellent in thermal shock resistance and fracture toughness. characteristics widely and attention in order to have, Therefore conventionally, as shown in the following ~, a manufacturing method of preparation and their organosilicon precursor SiC-Si ₃ N ₄ based ceramic according precursor method Various proposals have been made, but all of these proposals have problems. That is, in U.S. Pat. No. 3,853,567, chlorosilanes are reacted with amines, and then 200-8
A method of obtaining SiC-Si ₃ N ₄ based ceramics by heating to 00 ° C. to obtain carbosilazane, spinning, infusibilizing this and firing at high temperature at 800 to 2000 ° C. is disclosed. However, this method requires a high temperature of 520 to 650 ° C. to obtain carbosilazane, which is extremely difficult as an industrial production method, and the ceramic yield is about 55 when inorganicizing carbosilazane.
It has a drawback that the yield is as low as%. In the examples of this US patent specification, only methyltrichlorosilane and dimethyldichlorosilane as chlorosilanes and methylamine as amines are described.

US Pat. No. 4,097,294 shows that various silicon-containing polymers are converted to ceramic materials by thermal decomposition.
However, only one example of silazane polymer is disclosed, and the yield of ceramization is as low as 12% at maximum. Further, although it is described in this US patent specification that it is possible to make ceramics into fibers, to form a thin film, etc., this suggests only that possibility, and the polymer of the most important in the precursor method is No mention is made of moldability and processability.

JP-A-57-117532 discloses that a reaction between chlorodisilanes and disilazanes
JP-A-57-139124 discloses a reaction between chlorosilanes and disilazanes, which is disclosed in JP-A-58-63725.
JP-A-60-135431 discloses that a silazane polymer is obtained by a reaction between chlorodisilanes and ammonia, and JP-A-60-135431 discloses that a silazane polymer is obtained by a reaction between trichlorosilanes and disilazanes. Further, in US Pat. No. 4,535,007, by adding a metal halide to chlorosilanes and disilazanes,
JP-A-60-208331 discloses that a silazane polymer is produced by adding a metal halide to chlorodisilanes and disilazanes. It is said that any of the above silazane polymers can be made into ceramics by thermal decomposition.
However, the yield of ceramization for any silazane polymer is 50 to 60%, which is a low yield. Also,
The above-mentioned publications do not describe the moldability and processability of the polymer, which is the most important in the precursor method, in the same manner as the specification of, and particularly, there are no examples of fiberization or fiberization. Most of the examples described above do not mention the strength of the ceramized fiber. There is a slight description of strength in JP-A-60-208331, but in this case also, the tensile strength is 53 kg / mm.
Only very low strength of ² or 63 kg / mm ² was obtained.

Japanese Unexamined Patent Publication No. 60-226890 discloses that

[0007]

[Chemical 4] A method for obtaining a silazane polymer by obtaining an ammonolysis product by the reaction of an organosilicon compound represented by and ammonia, and then dehydrogenatively condensing the product with a hydride of an alkali metal or an alkaline earth metal is disclosed. There is.
It is said that the properties of the polymer obtained by this method can be variously adjusted from oily to solid without melting point depending on the degree of dehydrogenative condensation. But,
When a polymer is molded and processed from a molten state, for example, when a continuous fiber is produced by a melt spinning method, it is necessary that the polymer has a constant degree of polymerization and is thermally stable. If the reaction is not stopped midway, the polymer will become a solid without a melting point, and in order to obtain a meltable polymer, delicate control of the reaction time, reaction temperature, amount of catalyst, amount of solvent, etc. is required, and its adjustment There is a problem that it is extremely difficult and lacks reproducibility. Further, the polymer obtained by this method has the drawback that it is not thermally stable and accompanies the formation of a gel, and the above method is not suitable as an industrial production method of a silazane polymer from the above two points.

JP-A-60-228489 discloses that

[0009]

[Chemical 5] A method for obtaining a silazane polymer by forming a cyclic silazane from the compound represented by and monomethylamine and reacting the cyclic silazane with ammonia is disclosed. However, although the above-mentioned publication describes that the polymer is suitable as a material for chemical vapor deposition, there is no detailed description about the physical properties of the polymer, and the ceramic yield is also mentioned at all. Absent.

As described above, the conventionally proposed polysilazane polymer as a ceramic precursor is unsuitable for industrial production, and in addition, it is inferior in moldability and workability as a precursor of ceramic fibers and the like. The ceramic yield was low. Further, a ceramic product manufactured by using a conventional polysilazane polymer as a precursor, such as a ceramic fiber, is inferior in various physical properties such as strength and elastic modulus.

The present invention has been made in view of the above circumstances, and is a method for producing high-quality ceramics using a ceramics precursor suitable for industrial production, excellent in moldability and workability, and having a high ceramics yield. The purpose is to provide.

[0012]

Means for Solving the Problems That is, the inventors of the present invention have proposed a method for producing a ceramic product belonging to the precursor method, and a ceramic which is preferably used for producing the ceramic product and which is excellent in industrial property, workability and the like. to develop a method for manufacturing a precursor, focusing on the SiC-Si ₃ N ₄ ceramic having both excellent high temperature properties possessed by SiC and Si ₃ N _4, the manufacture of SiC-Si ₃ N ₄ based ceramic according precursor method As a result of earnest research on the method, an organosilicon compound represented by the following general formula [I] or the following general formula [I]
And a mixture of an organosilicon compound represented by the following general formula [II] and a disilazane represented by the following general formula [III] are reacted at a temperature of 25 to 350 ° C. under an anhydrous atmosphere to form a volatile component produced as a by-product. By distilling outside,
Extremely high strength, excellent thermal stability, and obtaining a polysilazane polymer having a constant degree of polymerization, and further melting this polysilazane polymer, after molding, infusible by heating in air or electron beam irradiation, ultraviolet irradiation, etc. The present invention has been completed based on the finding that it is possible to obtain high-quality ceramics composed mainly of SiC and Si ₃ N ₄ by firing.

[0013]

[Chemical 6](However, in the formula R Is hydrogen, chlorine, bromine, methyl group, ethyl
Group, phenyl group or vinyl group, R ₁Is hydrogen or methyl
The group, X, represents chlorine or bromine, respectively. The same applies hereinafter. )

[0014]

[Chemical 7](However, R ₂And R₃Is hydrogen, chlorine, bromine, methyl group,
Cyl group, phenyl group or vinyl group, X is chlorine or bromine
Shown respectively. The same applies hereinafter. )

[0015]

[Chemical 8](However, in the formula R _Four, R _FiveAnd R₆Is hydrogen, methyl group, ethi
Group, phenyl group or vinyl group. The same applies hereinafter. )

Therefore, the present invention provides an organosilicon compound represented by the above formula [I] or the above formula [I] and the above formula [II].
A mixture of the organosilicon compounds represented by the formula [III]
And a disilazane represented by
The reaction is carried out at 50 ° C., the volatile components produced as by-products are distilled out of the system to obtain an organic silazane polymer, and then the organic silazane polymer is melted and molded, further infusibilized, and then fired to obtain a ceramic. Provided is a method for producing a ceramic, which is characterized by being obtained.

The method for producing the organic silazane polymer used in the production of the ceramics of the present invention is carried out by using the formula [I] as a starting material.
Alternatively, an organosilicon compound of the formula [I] and the formula [II] is used, and the temperature is set to 2 with the disilazane of the formula [III] under an anhydrous atmosphere.
It is possible to obtain an organic silazane polymer having excellent thermal stability and having an unprecedented structural unit simply by reacting at 5 to 350 ° C. and distilling off by-product volatile components to the outside of the system. Therefore, according to this method, the moldability and processability are excellent, and the handleability is good because of its high strength and flexibility.
A high-quality organic silazane polymer having excellent infusibilizing property and high ceramic yield (usually 70 to 80%) can be industrially easily produced.

Furthermore, the present inventors previously mentioned a method for producing an organic silazane polymer using a ternary system of methyldichlorosilane, dimethyldichlorosilane and methyltrichlorosilane (Japanese Patent Laid-Open No. 62-290730) and methyl. Dichlorosilane, methyltrichlorosilane, the following general formula [I
V], a method for producing an organic silazane polymer using a ternary system of an organosilicon compound represented by the formula (JP-A-63-117037).
Issue).

[0019]

[Chemical 9](However, R ₇And R₈Is hydrogen or a methyl group, X is chlorine or
Bromine, R₉Is chlorine, bromine, methyl group, ethyl group or
Nyl group, R _TenIs hydrogen, chlorine, bromine, methyl group, ethyl group
Or a phenyl group, respectively. )

Compared with these methods, the method for producing an organic silazane polymer according to the present invention uses the above formula [I] or the organosilicon compound of the formula [I] and the formula [II] as a starting material, and formula [III] ] By reacting with the disilazane, the infusibilizing property of the obtained organic silazane polymer is improved, the ceramic yield is higher, and the handleability is good because it has high strength and flexibility and is industrially useful. Is advantageous to.

In addition, the method for producing a ceramic according to the present invention uses the above-mentioned organic silazane polymer as a precursor, so that a ceramic product having an excellent physical property and a stable quality and an appropriate shape can be obtained at a high yield. It can be easily manufactured.

The use of an organosilicon compound as a raw material for producing a silazane polymer, which is a ceramic precursor, has been conventionally known as described above. However, by selecting one or more of the above-mentioned organosilicon compounds as the organosilicon compound, and reacting these with the above-mentioned disilazane under specific conditions to distill a by-product out of the system, It is a new finding of the present inventors that a silazane polymer having unprecedented excellent properties can be obtained. That is, the formula [I] or the formula [I] and the formula [I
I] of the organosilicon compound, preferably the organosilicon compound of the formula [I] and the formula [II] at a mixing ratio of 50.
˜100 mol%: 0 to 50 mol%, the above-mentioned JP-A-57-117532,
JP-A-57-139124, JP-A-58-637
25, JP-A-60-135431, JP-A-62-290730, and JP-A-63-1703.
It has a structure different from that of the silazane polymer obtained by using the organosilicon compounds as described in JP-A-7-320, alone or in combination, and various repeating units and bonding structures of these repeating units are mixed. When a novel silazane polymer is obtained, and when this silazane polymer is used as a ceramic precursor as compared with an organic silazane polymer obtained by using the above-mentioned organosilicon compounds alone or in combination, In addition to having good infusibilizing property, it is a polymer having high strength and high flexibility, and having a novel structure different from such a conventional silazane polymer structure, and having excellent properties. By using the silazane polymer as the ceramic precursor, the ceramic yield is higher than that of the conventional ceramic manufacturing method using this type of precursor method. As well as improved tensile strength, that is the physical properties such as elastic modulus is remarkably produced improved stable quality ceramics, the present inventors are those found for the first time.

The present invention will be described in more detail below. In the method for producing an organic silazane polymer according to the present invention, the organosilicon compound represented by the above formula [I] is used as a starting material, or the compound represented by the formula [I] and The organosilicon compound of the formula [II] is mixed and used. In this case, the compounds of the formulas [I] and [II] are replaced by [I]: [II] 50
It is preferable to mix in a ratio of ˜100 mol%: 0 to 50 mol%. When the composition is out of the above range, the resulting silazane polymer has low strength and often lacks flexibility. For example, when the silazane polymer is melted and then spun to obtain a fibrous material, it may be wound or This may cause yarn breakage during various handlings such as processes, which may reduce the yield up to the final process or deteriorate the physical properties of the final product.

Here, as the compound of the formula [I], for example,
If ClH₂SiCH₂CH₂SiH₂Cl, Cl₂H SiCH₂
CH₂SiH Cl₂, Cl₃SiCH₂CH₂SiCl₃, C
l (CH₃)₂SiCH₂CH₂Si (CH₃)₂Cl, Cl
₂(CH₃) SiCH₂CH₂Si (CH₃) Cl₂, Cl
(CH₃)₂SiCH (CH₃) CH (CH₃) Si (CH
₃)₂Cl, Cl₂(CH₂= CH) SiCH₂CH₂Si
(CH = CH₂) Cl₂ Etc. Among these, 1,2-bis (black
Rodimethylsilyl) ethane, 1,2-bis (dichlorometh)
Cylsilyl) ethane, 1,2-bis (trichlorosilyl)
Le) ethane is preferably used.

Further, as the compound of the formula [II], for example,
If H₂SiCl₂, H SiCl₃, SiCl_Four, CH₃Si
Cl₃, (CH₃)₂SiCl₂, (C₂H_Five) SiCl₃，
(C₂H_Five)₂SiCl₂, C₆H_FiveSiCl₃, (C₆H_Five)₂
SiCl₂, CH₂= CHSiCl₃, (CH₂= CH)₂
SiCl₂, (CH₂= CH) (CH₃) SiCl₂Etc.
You can

The compounds of the formulas [I] and [II] may be used alone or as a multi-component system by combining two or more of the above compounds. .

Further, in the present invention, the above organosilicon compound is reacted with the disilazane of the above formula [III].

Here, the formulation of the disilazane of the formula [III]
The amount is the amount of the organosilicon compound of the formulas [I] and [II] above.
It suffices if it is an equimolar amount or more in terms of mol with respect to the amount of rogen.
Specifically as the disilazane of the formula [III], (H₃S
i)₂NH, {H₂(CH₃) Si}₂NH, {H (C
H₃)₂Si}₂NH, {(CH₃)₃Si}₂NH, {(C
₂H_Five)₃Si}₂NH, {(C₆H_Five)₃Si}₂NH, {C
H₂= CH (C H₃)₂Si}₂NH, {C H₂= CH (C₆
H_Five)₂Si}₂NH, {C H₂= CH (C₂H_Five)₂Si}₂
NH and the like are exemplified, and one or more of these may be used.
You can

In the present invention, the above formula [I],
When the organosilicon compound of [II] is reacted with the disilazane of the formula [III], the temperature is 25 to 350 ° C. under an anhydrous atmosphere.
The organic silazane polymer is obtained by reacting under the conditions described above and distilling off the volatile component produced as a by-product to the outside of the system. By reacting under such reaction conditions, the target silazane polymer can be obtained in various forms from oily to solid form, and further, a polymerization degree suitable as a precursor for ceramics fiber and excellent thermal stability can be obtained. A silazane polymer having the same can be obtained.

In this case, the organosilicon compound or disilazane may be dissolved in a solvent, but it is usually preferable to use it without a solvent. Regarding the reaction conditions, an anhydrous atmosphere has a reaction temperature of 25 to 350.
C., preferably 150 to 320.degree. Reaction temperature is 2
If it is lower than 5 ° C., the reaction does not proceed, and if it is higher than 350 ° C., the reaction rate becomes fast, and it is difficult to adjust the silazane polymer to a desired degree of polymerization.

When the organosilicon compound is reacted with disilazane in this way, the reactions of the following reaction formulas A and B occur successively.

[0032]

[Chemical 10]

That is, first, as shown in reaction formula A, the formula [I]
Alternatively, the organosilicon compound of the formula [I] and the formula [II] and the formula [I
II] reacts with the disilazane to form a compound of formula [V] and a volatile compound of formula [VI] as a by-product.
Of these, the by-product of the formula [VI] is distilled out of the system under normal pressure or reduced pressure as the reaction progresses. Further, subsequently, as the temperature rises, a condensation reaction of the compound of the formula [V] begins to occur as shown in the reaction formula B, and a desired higher molecular weight silazane polymer (formula [VII]) is produced. The disilazane of the formula [III], which is by-produced together with the silazane polymer of the formula [VII], is distilled out of the system by distillation under normal pressure or reduced pressure in the same manner as the by-product of the formula [VI] and reused. Is possible.

The degree of polymerization and melting point of the silazane polymer can be appropriately adjusted by changing the compounding ratio of the raw material organosilicon compound used, the reaction temperature, the reaction time, etc. It is also possible to adjust the viscosity, melting point and the like by distilling off the oligomer having a low viscosity under reduced pressure while heating.

The organic silazane polymer thus obtained takes advantage of its high moldability and processability, and is formed into a suitable shape as a ceramic precursor, particularly in the form of fiber or sheet, as shown below. To do.

The method for producing ceramics according to the present invention is
The above-mentioned organic silazane polymer is melted, molded, further infusibilized, and then fired. In this case, the polymer has a melting point of 60 to 250 ° C. and a molecular weight of 800 to 50.
It is preferable to use the one of 00 (benzene molar freezing point depression method).

Further, the organic silazane polymer obtained by the above reaction may be melted and molded as it is, but the silazane polymer is dissolved in an organic solvent such as hexane, benzene, toluene, tetrahydrofuran, etc., and after filtration. It is preferable to remove the insoluble matter by distilling off the solvent under reduced pressure or filtering the melt as it is when it is hot. By carrying out such a treatment, a silazane polymer having the above melting point and molecular weight can be obtained more reliably, and the polymer can be easily melted and molded.

The method of melting, shaping and firing the organic silazane polymer is not particularly limited, and various shaped ceramic products can be obtained by shaping the polymer into an appropriate shape and firing it.

For example, in the case of producing ceramic fibers, the organic silazane polymer can be first melted by heating and then spun by the melt spinning method. In this case, the spinning temperature in this step depends on the melting point of the polymer, but usually 1
It is preferably carried out in the range of 00 to 300 ° C.

Next, the filament obtained in this spinning step is heated in air or irradiated with an electron beam in vacuum or in N ₂ gas to make it infusible, or in N ₂ gas or Ar gas. UV irradiation is performed in the inert atmosphere described above to make the material infusibilized. In this step, heating in air is preferably performed at a temperature lower than the melting point, for example, in the temperature range of 50 to 200 ° C. In this case, if the temperature is lower than 50 ° C, the polymer does not become infusible, and if the temperature is higher than 200 ° C, the polymer may melt. The electron beam irradiation is performed in vacuum or in an N ₂ gas atmosphere at 1
The irradiation is preferably performed at an irradiation amount of 0 to 2000 Mrad, and if the irradiation amount is less than 10 Mrad, the fibers may be fused together during firing.

Further, the irradiation of ultraviolet rays has a wavelength of 250 to 400 n.
It is preferable to use an easily available commercially available UV lamp and to appropriately control the intensity of the light source, the irradiation distance, and the irradiation time according to the infusibilizing performance of the organic silazane polymer to adjust the amount of ultraviolet light. Furthermore, when light infusibilized in the ultraviolet, the formula [I was relatively high content vinyl group as a substituent R ₂
It is preferable to use an organic silazane polymer obtained from the organosilicon compound of [I]. It should be noted that an organic silazane polymer having a low vinyl group content can also be photo-infusible with ultraviolet rays by previously adding a photosensitizer or a vulcanizing agent to the organic silazane polymer. In this case, generally, when a large amount of the photosensitizer or the vulcanizing agent is added, various properties of the polymer are affected, so that the addition amount of about 0.001 to 5% by weight is preferable. If the addition amount is less than 0.001% by weight, fusion may occur. Examples of the sensitizer include benzophenone, rose bengal and acetophenone, and examples of the vulcanizing agent include diphenyl disulfide, 1,3-benzenedithiol and 2,2′-dithiobis (benzothiazole).

Then, the infusibilized filamentous material is fired at a high temperature under no tension or tension to obtain SiC, Si.
It is possible to obtain a ceramic fiber mainly composed of ₃ N ₄ and having excellent strength and elastic modulus. In this process, firing is performed in vacuum or in an inert gas such as Ar, N ₂ gas, H ₂ gas, N ₂ .
700 in one or more gases such as H ₃ gas
It is preferable to carry out at ˜2000 ° C., especially 700˜1500 ° C. In this case, firing under tension is particularly preferred, which results in a tensile strength of 230-310 kg / m.
It is possible to manufacture high-quality ceramic fibers having physical properties of m ² and an elastic modulus of 16 to 30 t / mm ² .

In addition, when the organic silazane polymer is added to the powder of one or more kinds of inorganic compounds selected from alumina, silicon carbide, silicon nitride, boron nitride, etc. as a binder during firing, high-quality ceramics can be easily obtained. A molded body can be obtained.

[0044]

As described above, according to the present invention,
It is thermally stable and has a certain degree of polymerization, so it has excellent moldability and processability, and also has good infusibilization properties. Furthermore, it has high strength and flexibility, so it is easy to handle. An organic silazane polymer, which is excellent and has a high ceramic yield and can be particularly preferably used as a precursor for ceramic fibers, can be industrially advantageously produced, and a high-quality organic silazane polymer can be used. Ceramics mainly composed of SiC and Si ₃ N ₄ can be obtained with a high ceramic yield. In this case, according to the method of the present invention, a ceramic product having a desired shape, such as a ceramic fiber, a ceramic sheet, or a ceramic molded body, can be manufactured with a high yield and with stable quality. It is possible to obtain excellent ceramic fibers, sheet moldings and the like.

[0045]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example]Polymerization process [1,2-bis (methyldichlorosilyl) ethane] stirring
Equipped with a machine, thermometer, gas inlet tube, distillation device, and dried
In a 500 ml four-necked flask, 1,2-bis (methyldiethyl)
76.8 g (0.3 mol) of chlorosilyl) ethane and
{(CH₃)₃Si}₂NH177.5g (1.1mo
I) was charged. Then N₂Gradually mix the mixture under atmosphere
(The reflux starts when the pot temperature reaches 92 ° C.)
However, the vapor temperature was 59 ° C.)
The reaction temperature is gradually raised to 30 while distilling the volatile components out of the system.
It was raised to 0 ° C. and kept at this temperature for 3 hours. N ₂air flow
Underneath, cool the reaction to room temperature and add 100 ml to the reaction.
Dehydrated hexane was added and dissolved, and the insoluble matter was filtered.
After that, add hexane and low molecular weight substances at 200 ° C, 10 mmHg
Stripped below. Residue is a glassy yellow solid polymerized
59 g was obtained in a body. This product has a molecular weight of 2650 (benzene
Molar freezing point depression method, and so on. ), Melting point 130 ° C.
The residual chlorine was 100 ppm or less from the potentiometric titration.
It was Also, from the IR, 3400 cm^-1NH, 2980
cm^-1CH, 1260cm^-1On SiCH₃Each of the sucking
Income was recognized.Polymerization process [1,2-bis (methyldichlorosilyl) ethane: methyl
Ludichlorosilane = 80: 20 (mol%)] 1,2-bi
61.4 g (0.2%) of (methyldichlorosilyl) ethane
4 mol), 6.9 g (0.06) of methyldichlorosilane
mol), {(CH₃)₃Si}₂NH177.5g
(1.1 mol) was added to 500 ml of 4 as in the polymerization step.
Charged in a one-necked flask and kept at a reaction temperature of 300 ° C for 1 hour.
Was reacted, cooled and treated in the same manner. Light yellow solid 5
3 g was obtained, which had a molecular weight of 2100 and a melting point of 82 ° C.
Met.Polymerization process [1,2-bis (methyldichlorosilyl) ethane: methyl
Lutrichlorosilane = 70: 30 (mol%)] 1,2-
53.8 g of bis (methyldichlorosilyl) ethane (0.
24 mol), 13.4 g of methyltrichlorosilane
(0.06 mol), {(CH₃)₃Si}₂NH194
g (1.2 mol) of 500 ml as in the polymerization step
Charge in a 4-neck flask and react at reaction temperature of 280 ° C for 30 minutes.
Reacted and treated. 43.7 g of a pale yellow solid are obtained,
This product had a molecular weight of 1800 and a melting point of 70 ° C.Polymerization process [1,2-bis (methyldichlorosilyl) ethane: vinyl
Lutrichlorosilane = 70: 30 (mol%)] 1,2-
Bis (methyldichlorosilyl) ethane 125.4g
(0.49 mol), vinyltrichlorosilane 33.9
g (0.21 mol), {(CH₃)₃Si}₂NH25
8.2 g (1.6 mol) was added to 1 liter as in the polymerization step.
Charge to a 4-necked 4-necked flask at a reaction temperature of 250 ° C.
It was allowed to react for a time and treated. 103.5 g of a light yellow solid is obtained
It has a molecular weight of 3100 and a melting point of 110 ° C.
It was Also, from the IR, 3400 cm^-1NH, 2950
cm^-1C-H, 1260 cm^-1Si-Me, 142
0 cm^-1To CH₂Each absorption of = CH- was observed.Polymerization process [1,2-bis (trichlorosilyl) ethane: methyldi
Chlorosilane: Methylvinyldichlorosilane = 50: 2
5:25 (mol%)] 1,2-bis (trichlorosilyl)
Le) ethane 44.6 g (0.15 mol), methyldi
8.6 g (0.075 mol) of lorosilane, methyl vinyl
10.6 g (0.075 mol) of ludichlorosilane,
{(CH₃)₃Si}₂NH129g (0.8mol)
As in the polymerization process, charge into a 500 ml four-necked flask.
Then, the reaction was carried out at a reaction temperature of 260 ° C. for 2 hours. Light yellow solid
45 g were obtained, which had a molecular weight of 2720 and a melting point of 12
It was 5 ° C. Also, from the IR, 3400 cm^-1To N
H, 2950 cm^-1C-H, 2150 cm^-1To Si-
H, 1260 cm^-1On Si-Me, 1420 cm^-1To C
H₂Each absorption of = CH- was observed.Polymerization process [1,2-bis (methyldichlorosilyl) ethane: vinyl
Lutrichlorosilane = 98: 2 (mol%)] 1,2-bi
75.3 g of su (methyldichlorosilyl) ethane (0.2
94 mol) and 0.9 g of vinyltrichlorosilane (0.
06 mol), {(CH₃)₃Si}₂NH218.9g
500 ml of (1.356 mol) as in the polymerization step
In a 4-necked flask with a reaction temperature of 240 ° C for 1.5
Reacted for hours. 57 g of a white solid are obtained, which is
It had a molecular weight of 2250 and a melting point of 86 ° C. Also, from IR
Is 3400 cm^-1NH, 2950 cm^-1C-H, 1
420 cm^-1To CH₂= CH-, 1260cm^-1To Si
-Each absorption of Me was observed.Polymerization process [1,2-bis (methyldichlorosilyl) ethane: 1,
2-bis (trichlorosilyl) ethane: vinyl trichloro
Rosilane = 50:20:30 (mol%)] 1,2-bis
(Methyldichlorosilyl) ethane 38.4 g (0.15
mol), 1,2-bis (trichlorosilyl) ethane 1
7.8 g (0.06 mol), vinyltrichlorosilane
13.5 g (0.09 mol), {(CH₃)₃Si}₂
NH184g (1.14 mol) was used in the same manner as in the polymerization step.
Charge into a 500 ml four-necked flask, and set the reaction temperature to 250.
The reaction was carried out at 0 ° C for 2 hours. 49 g of a white solid are obtained, which
The product had a molecular weight of 4200 and a melting point of 220 ° C. Also,
3400 cm from IR^-1NH, 2950 cm^-1To C
-H, 1420 cm^-1To CH₂= CH-, 1260cm
^-1Each absorption of Si-Me was recognized.

The melt spun silazane polymer 30g obtained in the fiberization step polymerization process at 190 ° C. The mono-hole spinning apparatus. 3 spinning
After a lapse of time, it was very good, and the winding speed was 400 m / min. The raw silk thus obtained was stronger than ever before, and its tensile strength was measured and found to be 10 kg / mm ² . Then, the obtained raw silk was infusibilized with an electron beam at 2000 Mrad. After that, under slight tension, 1 in N ₂ stream
Baking was performed at 1100 ° C. for 30 minutes at a heating rate of 00 ° C./Hr. The ceramic yield was 72%, the obtained fiber had a fiber diameter of 8μ, a tensile strength of 270 kg / mm ² , and an elastic modulus of 1.
The physical properties were 8 t / mm ² . In addition, when the fiber composition was analyzed by elemental analysis, Si58.8%, C2
SiC-containing 5.8%, N15.2%, and O0.2%
It was confirmed that the fiber was mainly composed of Si ₃ N ₄ . The silazane polymer 20g obtained in the fiberization process polymerization step was melt-spun at 140 ° C. using the same spinning apparatus and fiberizing process. At a winding speed of 420 m / min, spinning was very good. Further, the obtained raw silk was infusibilized at 500 Mrad with an electron beam device under a slight tension. Then, it was calcined at 1200 ° C. for 30 minutes at a temperature rising rate of 100 ° C./Hr in a N ₂ stream under no tension. The ceramic yield was 70%, and the obtained fiber had a fiber diameter of 7 μ, a tensile strength of 280 kg / mm ² , and an elastic modulus of 20 t / mm ² . Elemental analysis of the fiber composition revealed that the fiber was mainly composed of SiC-Si ₃ N ₄ . The silazane polymer 20g obtained in the fiberization process polymerization step was melt-spun at 130 ° C. using the same spinning apparatus and fiberizing process. At a winding speed of 450 m / min, spinning was very good. Further, the obtained raw silk in the air at 50 to 80 ° C
It was made infusible by heating at (5 ° C./Hr). Then
Firing was performed at 1150 ° C. for 30 minutes at a temperature rising rate of 100 ° C./Hr in a N ₂ stream under a slight tension. Ceramic yield is 68%, fiber diameter 6μ, tensile strength 230kg /
mm ^2, was fibers mainly composed of SiC-Si ₃ N ₄ modulus 19t / mm ^2. Fiberizing process To 30 g of the silazane polymer obtained in the polymerization process, 0.06 g of rose bengal as a photosensitizer was added, dissolved in tetrahydrofuran and mixed, and then 1 tetrahydrofuran was added.
It was removed under reduced pressure of 00 ° C. and 5 mmHg. Next, melt spinning was performed at 170 ° C. and a winding speed of 420 m / min using the same spinning device as in the fiberizing step. The raw silk thus obtained was irradiated with light for 3 hours at a distance of 15 cm by using an ultraviolet irradiation device (mercury lamp H-400P type for Toshiba photochemistry) under N ₂ flow under slight tension to infusibilize. Then, the obtained fiber was fired under tension in N ₂ gas stream at 1200 ° C. for 1 hour at a temperature rising rate of 100 ° C./Hr. Ceramic yield is 74%, fiber diameter 7μ, tensile strength 250k
g / mm ^2, was fibers mainly composed of SiC-Si ₃ N ₄ modulus 23t / mm ^2. Fiberizing step To 30 g of the silazane polymer obtained in the polymerization step, 0.06 g of diphenyl disulfide as a vulcanizing agent was added, dissolved and mixed in tetrahydrofuran, and then 1 tetrahydrofuran was added.
It was removed under reduced pressure of 00 ° C. and 5 mmHg. Next, melt spinning was performed using the same spinning device as in the fiberizing step. The raw silk thus obtained was irradiated with light using an ultraviolet device similar to that used in the fiberizing step to carry out infusibilization treatment. Then, the raw silk thus obtained was subjected to a tension of 11 ° C. in a N ₂ gas stream at a heating rate of 100 ° C./Hr.
It was baked at 00 ° C for 30 minutes. Ceramic yield is 68
%, Fiber diameter 8 μ, tensile strength 235 kg / mm ² ,
It was a fiber mainly composed of SiC-Si ₃ N ₄ having an elastic modulus of 20.5 t / mm ² . Fiberizing step 0.003 g of 1,3-benzenedithiol as a vulcanizing agent was added to 30 g of the silazane polymer obtained in the polymerization step,
Further, 3 mg of benzophenone as a sensitizer was dissolved in 1 liter of tetrahydrofuran, and 100 ml of this solution was added and dissolved. Then, tetrahydrofuran was distilled off under reduced pressure, and melt spinning was performed at 170 ° C. using the same spinning device as in the fiberizing step. Further, the raw silk thus obtained was subjected to an optical infusibilization treatment in the same manner as in the fiberizing step, and was then calcined at 1100 ° C. for 30 minutes at a temperature rising rate of 100 ° C./Hr in a N ₂ gas stream under a slight tension. The ceramic yield was 70%, and the fiber was mainly composed of SiC-Si ₃ N ₄ having a fiber diameter of 9 μ, a tensile strength of 260 kg / mm ² , and an elastic modulus of 20 t / mm ² .

0.5 g of the silazane polymer obtained in the step of polymerizing the ceramic molded body and SiC
10 g of fine powder and 2 g of hexane were dispersed and kneaded, and then hexane was evaporated. This powder was pressure-molded at a molding pressure of 1000 kg / mm ² to obtain a powder compact having a diameter of 25 mm and a thickness of 10 mm. Then, this green compact was heated in an argon atmosphere from room temperature to 1000 ° C. for 2 hours, and then from 1000 ° C. to 195 ° C.
When the temperature was raised to 0 ° C. over 1 hour, the temperature was kept at 1950 ° C. for 30 minutes and then cooled, the density was 2.85 g / cm ³ ,
A SiC molded body having a bending strength of 30 kg / mm ² was obtained.

[Comparative Example] Polymerization step 50 equipped with a stirrer, a thermometer, a gas introduction tube, and a distillation apparatus
In a 0 ml dry four-necked flask, 35.8 g (10.24 mol) of methyltrichlorosilane, 7.7 g (0.06 mol) of dimethyldichlorosilane, and {(CH ₃ ) ₃ S were added.
i} ₂ NH137.2 g (0.85 mol) was charged. Then, the reaction was carried out at a reaction temperature of 270 ° C. for 30 minutes in the same manner as in the polymerization step of the above-mentioned example, and then cooled to room temperature. 21 g of a blue-yellow solid is obtained, which has a molecular weight of 17
00, melting point 65 ° C.

Fiberizing Step 20 g of the obtained silazane polymer was added to a monohole (nozzle,
(Diameter 0.5 mm) Charged into a spinning machine and under a N ₂ gas flow of 120
It was melted at ° C and spun. The spinning was severe in yarn breakage, and the obtained raw yarn was very brittle. The strength of the raw yarn was measured and found to be 0.5 kg / mm ² . Then, this raw silk is 2000 Mrad using an electron beam device.
Was infusibilized and baked at 1100 ° C. for 30 minutes at a temperature rising rate of 100 ° C./Hr under N ₂ gas flow. The ceramic yield was 48%, and the obtained fibers were partially fused. Moreover, the fiber physical properties of the unfused portion were measured, and the fiber diameter was 8 μ, the tensile strength was 20 kg / mm ² , and the elastic modulus was 4 t / m.
It had very low physical properties at m ² .

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Claims (2)

[Claims] 1. The following general formula [I]: Or an organic silicon compound represented by the above formula [I] and the following general formula [II] And a mixture of an organosilicon compound represented by the following general formula [I
II] With a disilazane represented by
The reaction is carried out at 5 to 350 ° C, the volatile component produced as a by-product is distilled out of the system to obtain an organic silazane polymer, and then the organic silazane polymer is melted and molded, further infusibilized, and then fired. A method for producing ceramics, which comprises obtaining the ceramics. 2. The production method according to claim 1, wherein the organic silazane polymer is added to the inorganic compound powder as a binder and fired.