JPH0755860B2 - Carbonaceous inorganic material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a carbonaceous inorganic material having excellent mechanical strength, heat resistance, and abrasion resistance.

(Prior art and its problems) Conventionally, carbon materials have been characterized by high temperature characteristics in a non-oxidizing atmosphere,
It has a low coefficient of thermal expansion, chemical resistance, weather resistance, radiation resistance, lubricity, and easy control of electrical and thermal conductivity, and is used as a high-temperature structural material, friction material and the like.

However, since carbon materials have low oxidation resistance, they cannot be used at high temperatures in an oxidizing atmosphere. Further, although it has excellent lubricity, its surface hardness is low, so that the wear resistance is not always sufficient.

In order to improve these drawbacks, a method of forming a coating layer of ceramic or the like on the surface of the carbon material by a gas phase reaction method or the like has been devised. However, this method has a drawback that the above-mentioned drawbacks cannot be sufficiently overcome because the coating layer is thin and easily peeled off, and the cost is high because a special device is required.

Further, in JP-A-60-195076 and JP-A-60-251175, there is disclosed a method for improving the above-mentioned defects by impregnating a carbon material with molten silicon and reacting it to generate silicon carbide on the surface and inside. It is disclosed. In addition, JP-A-60-255669
The publication discloses a method for improving the above drawbacks by impregnating and reacting titanium or zirconium with silicon to generate titanium carbide or zirconium carbide in addition to silicon carbide inside the carbon material. .
However, the carbon materials obtained by these methods are not excellent in high-temperature characteristics such as creep deformation at high temperatures because metal silicon remains in the formed body, and mechanical properties are not inevitable. .

(Means for Solving the Problem) An object of the present invention is to provide a novel carbonaceous inorganic material that solves the above problems.

Another object of the present invention is to provide an oxidation resistant carbonaceous inorganic material which is less deteriorated in a high temperature oxidizing atmosphere.

Another object of the present invention is to provide a carbonaceous inorganic material having excellent wear resistance.

Another object of the present invention is to provide a carbonaceous inorganic material that can be manufactured at a low temperature.

The carbonaceous inorganic material of the present invention is an inorganic material obtained from a metal-containing polycyclic aromatic polymer, and its constituent components are: i) a polycyclic aromatic compound in a mesophase state which constitutes the polymer. Crystalline carbon, or crystalline carbon and amorphous carbon, ii) crystalline carbon in an unoriented state and / or amorphous carbon derived from an optically isotropic polycyclic aromatic compound constituting the polymer Carbon, and iii) an amorphous substance consisting essentially of Si, M, C and O, and / or substantially β-SiC, MC, a solid solution of β-SiC and MC and MC
_{1-x is} an aggregate of crystalline ultrafine particles having a particle size of 500 Å or less and amorphous SiO _y and MO _z, and the ratio of the constituent elements is Si; 5 to 60 wt%, M; 0.5 to 45 weight%,
C: 30-40 wt% and O: 0.01-30 wt% Si-MC
-O substance (in the above formula, M is at least one element selected from Ti, Zr, and Hf, and 0 <x <1, 0 <y ≦
2, 0 <z ≦ 2. ) Consists of.

All "parts" in the following description are parts by weight, and "%"
Is "% by weight".

The carbonaceous inorganic material of the present invention comprises the above constituent components i), ii) and iii), and Si; 0.5 to 50%, M; 0.01 to 10
%, C; 40-97% and O; 0.1-10%.

The crystalline carbon that is a constituent component of this carbonaceous inorganic material is 500
In a high resolution electron microscope with a crystallite size of Å or less and a resolution of 1.5Å, it was oriented in the fiber axis direction.3.
It is an ultrafine graphite crystal in which a fine lattice image corresponding to the 2Å (002) plane can be observed.

Further, the constituent component iii) is distributed very uniformly so as to enclose the graphite microcrystals.

The ratio of constituent iii) to the total 100 parts of constituents i) and ii) in this carbonaceous inorganic material is 0.5 to 500 parts, and the ratio of constituents i) and ii) is 1: 0.02 to 4. .

Component ii for 100 parts of the sum of components i) and ii)
When the ratio of i) is less than 0.5, the carbonaceous inorganic material is almost the same as the carbon matrix, and improvement in oxidation resistance and wear resistance cannot be expected. The inorganic inorganic material has the same high temperature characteristics and poor lubricity as the silicon carbide matrix.

The carbonaceous inorganic material of the present invention comprises 1) a bonding unit (Si—CH ₂ ), or a bonding unit (Si—CH ₂ ) and a bonding unit (Si—Si) as a main component, and a hydrogen atom in a side chain of silicon, It has a lower alkyl group, a phenyl group, or a silyl group, and from the above bond unit to the silicon atom of the main skeleton, M
However, at least a part of the silicon atoms of the transition metal-containing organosilicon polymer bonded to at least a part of the silicon atoms directly or through an oxygen atom is obtained from a petroleum-based or coal-based pitch or a heat-treated product thereof. Random copolymer in which the carbon of the aromatic ring of the polycyclic aromatic compound is bound via a silicon-carbon linking group, and 2) mesophase or mesophase and optical etc. obtained from petroleum-based or coal-based pitch A polycyclic aromatic compound composed of both a phase and a phase (hereinafter, both may be collectively referred to as "mesophase polycyclic aromatic polymer") and heated at a temperature in the range of 200 to 500 ° C. First step of reacting and / or melting by heating to obtain a metal-containing polycyclic aromatic polymer, a metal-containing polycyclic aromatic polymer, or a mixed powder of a metal-containing polycyclic aromatic polymer and a fine powder of its calcined product Mold press Second step of molding using a normal method such as isotropic hydrostatic pressing, hot pressing, etc. After the above-mentioned molded body is infusibilized as necessary, it is vacuumed or in an inert gas at a temperature of 800 to 3000 ° C. Baked,
Third step of mineralizing, the pores of the carbonaceous inorganic material obtained by the above steps are impregnated with a melt or solution of a metal-containing polycyclic aromatic polymer as necessary, followed by firing, and the treatment of mineralization is repeated. It is provided by the manufacturing method comprising the fourth step of increasing the density by carrying out.

It is also possible to manufacture the above second to fourth steps as one step by high temperature hot pressing or the like.

Each of the above steps will be specifically described.

First step: The precursor polymer 1) is prepared by heating and reacting the organosilicon polymer and pitch in an inert gas, preferably at a temperature in the range of 250 to 500 ° C.

The organosilicon polymer, which is one of the starting materials of the precursor polymer 1), is obtained, for example, by heating polymethylsilane obtained by the reaction of dimethyldichlorosilane and metallic sodium to 400 ° C. or higher in an inert gas. To be The organosilicon polymer has a bonding unit (Si—CH ₂ ) or a bonding unit (S
i-CH ₂ ) and a bonding unit (Si-Si), and the ratio of the total number of bonding units (Si-CH ₂ ) to the total number of bonding units (Si-Si) is within the range of 1: 0 to 20. is there.

The organosilicon polymer generally has a weight average molecular weight ( _Mw ) of 300 to 1000 and a _Mw of 400 to 800, which is a random raw material for obtaining an excellent carbonaceous inorganic material. Especially preferred for preparing polymer 2).

The other starting material for the precursor polymer 1), pitch, is
Pitch obtained from petroleum or coal, particularly preferable pitch is heavy oil obtained by fluid catalytic cracking of petroleum, distillate components or residual oil obtained by distilling the heavy oil, and further these It is a heat-treated product. It is preferable that the pitch contains 5 to 98%, especially 40 to 90%, of an insoluble component in an organic solvent such as benzene, toluene, xylene, and tetrahydrofuran, and a pitch having an insoluble component of less than 5% is used as a raw material. When used as, the residual rate at the time of mineralization of the molded article becomes low, the pores are likely to remain, and the crystallinity becomes low, so an excellent carbonaceous inorganic material cannot be obtained, and the insoluble component When it is higher than 98%, insoluble and infusible caulks are likely to be formed, which is disadvantageous in molding.

The weight average molecular weight (M _w ) of this optically isotropic pitch is
The melting point is 300 to 3000, and the melting point is 70 to 200 ° C. The weight average molecular weight is a value determined as follows. That is, if the pitch does not contain an organic solvent insoluble matter for gel permeation chromatograph (GPC) measurement such as benzene, toluene, xylene, tetrahydrofuran, chloroform and dichlorobenzene, the GPC measurement is performed as it is, and the pitch contains the organic solvent insoluble matter. If contained, hydrogenate under mild conditions,
GPC measurement is performed after changing the organic solvent insoluble matter to a component soluble in organic solvent. (The weight average molecular weight of the polymer containing an organic solvent insoluble matter is a value obtained by performing the same treatment as above).

The usage ratio of pitch is 10 to 1 per 100 parts of the organosilicon polymer.
It is preferably 900 parts. If the proportion of the pitch used is excessively small, the silicon carbide component in the obtained carbonaceous inorganic material will increase, and the lubricating properties of carbon and the high-temperature characteristics in a non-oxidizing atmosphere will be lost. If it is excessively large, the amount of silicon carbide component decreases, and the oxidation resistance and wear resistance of the carbonaceous inorganic material deteriorate.

If the reaction temperature of the above reaction is excessively low, the bond between the silicon atom and the aromatic carbon is hard to be generated, and if the reaction temperature is excessively high, decomposition and high molecular weight of the generated precursor copolymer 1) occur violently. Not preferable.

The precursor polymer 1) referred to here includes, in addition to the copolymer in which the organosilicon polymer and the pitch are bonded via the silicon-carbon linking group, each polycondensate of the organosilicon polymer and the pitch.

Nitrogen, argon and the like are preferably used as the inert gas.

Next, the precursor polymer 1) and the transition metal compound represented by the formula MX ₄ are reacted at a temperature in the range of 100 to 500 ° C.

In the above MX ₄ , M is at least one element selected from Ti, Zr and Hf, and X is a compound in which M can be bonded to silicon of the precursor polymer 1) directly or through an oxygen atom by condensation. There is no particular limitation as long as it is present, but a halogen atom, an alkoxy group, or a complex-forming group such as β-diketone is preferable.

If the reaction temperature is excessively low, the condensation reaction between the precursor association 1) and the formula MX ₄ will not proceed, and if the reaction temperature is excessively high, the crosslinking reaction of the precursor polymer 1) via M will proceed excessively. Gelation occurs, the precursor polymer 1) itself condenses to a high molecular weight, or MX ₄ is volatilized in some cases, and is a random copolymer that is an intermediate raw material for obtaining an excellent carbonaceous inorganic material. 2) cannot be obtained.

As an example, when M is Ti and X is OC ₄ H ₉ , the reaction temperature is 2
00 to 400 ° C is suitable.

By this reaction, a random copolymer 2) in which at least a part of silicon atoms in the precursor polymer 1) is bonded to M directly or via an oxygen atom is prepared. M can also be bonded to the silicon atom of the precursor polymer 1) in a side chain form by a bonding mode such as -MX ₃ or -O-MX ₃ , and M can be directly or oxygen bonded to the silicon atom of the precursor polymer 1). It is also possible to adopt a mode of bonding that is cross-linked via.

As a method of preparing the random copolymer 2), a method of reacting an organosilicon polymer with MX ₄ and further reacting the obtained product with pitch can be used in addition to the method described above.

In the random copolymer 2), the bonding unit (M) of the transition metal compound is 0.2% to 35%, particularly 0.5% based on the total weight of the bonding unit (Si-CH ₂ ) and the bonding unit (Si-Si). % To 20% is preferable.

In the first step, finally, the random copolymer 2) and the mesophase polycyclic aromatic compound are heated and / or melted by heating to prepare a metal-containing polycyclic aromatic polymer 3).

The mesophase polycyclic aromatic compound can be prepared, for example, by heating petroleum-based or coal pitch to 300 to 500 ° C. in an inert gas, and polycondensing while removing the soft fraction produced.

If the polycondensation reaction temperature is appropriately low, the condensed ring will not grow sufficiently, and if the temperature is too high, an insoluble and infusible product will be produced by coking.

The above mesophase polycyclic aromatic compound has a melting point of 200
~ 400 ℃ range, the weight average molecular weight is 200 ~ 1000
It is 0.

Among the mesophase polycyclic aromatic compounds, 20-100
%, Especially 40-100% optical anisotropy, 2-60%
The quinoline-insoluble matter and the quinoline-insoluble matter of 30 to 100% of benzene, toluene, xylene, or tetrahydrofuran are particularly preferable for improving the mechanical performance of the carbonaceous inorganic material.

The proportion of the mesophase polycyclic aromatic compound used is preferably from 5 to 1900 parts per 100 parts of the random copolymer 2), and when it is less than 5 parts, the mesophase content in the product is insufficient, resulting in excellent high temperature properties. If the carbonaceous inorganic material cannot be obtained, and if it is more than 1900 parts, a carbonaceous inorganic material excellent in oxidation resistance and abrasion resistance cannot be obtained due to lack of silicon component.

By heating and melting the random copolymer 2) and the mesophase polycyclic aromatic compound in the temperature range of 200 to 500 ° C., at least a part of the random copolymer 2) is mesophase polycyclic aromatic compound. A metal-containing polycyclic aromatic polymer 3) bound to the compound is obtained. However,
The term "bond" as used herein means a chemical bond between silicon and carbon of the polycyclic aromatic compound and / or a polycyclic aromatic ring portion chemically bonded to silicon in the random copolymer 2) and a mesophase polycyclic aromatic compound. It means physical coupling such as van der Waals coupling between.

When the melt-mixing temperature is lower than 200 ° C, an infusible portion is generated,
The system becomes non-uniform, and an excellent carbonaceous inorganic material cannot be obtained,
Further, if the melt-mixing temperature is higher than 500 ° C., the condensation reaction may proceed violently and block-shaped infusible matter may occur, which is disadvantageous in molding.

As a method for preparing the metal-containing polycyclic aromatic polymer 3), in addition to the above-mentioned method, an organosilicon polymer is reacted with pitch, and mesophase pitch and MX ₄ are simultaneously or sequentially added to the obtained product. A method of further reacting and preparing is also possible.

The weight average molecular weight of the metal-containing polycyclic aromatic polymer 3) is 20.
It has a melting point of 200 to 400 ° C. at 0 to 11000.

Second step: The metal-containing polycyclic aromatic polymer 3) or a mixed powder of the metal-containing polycyclic aromatic polymer 3) and the fine powder of the calcined product is pulverized, and a usual carbon material molding method is used. It can be molded. The calcination can be performed at a temperature in the range of 800 to 1300 ° C.

Further, the molding method can be arbitrarily selected from the usual carbon material molding methods in consideration of the shape, size, application, productivity, etc. of the molded body. A dry mold pressing method is used for producing with high productivity, and an isotropic hydrostatic pressing method (rubber pressing method) is used for obtaining a molded article having a slightly complicated shape. A metal-containing polycyclic aromatic polymer is used. Examples of the method for melting and molding 3) include a hot press molding method, an injection molding method and an extrusion molding method.

Further, the use ratio of the metal-containing polycyclic aromatic polymer 3) and the calcined product thereof can be appropriately determined in consideration of the shape of the molded product, application, cost and the like.

Third step: The above-mentioned molded body is subjected to infusibilization treatment if necessary.

A typical infusibilizing method is a method of heating the molded body in an oxidizing atmosphere. The temperature of infusibilization is preferably 50 to 400
The temperature is in the range of ° C. If the infusibilization temperature is too low, no polymer sticking occurs, and if this temperature is too high, the polymer burns.

The purpose of the infusibilization is to make the polymer constituting the molded body into a state of infusible and infusible with a three-dimensional structure so that the molded body is not melted at the time of mineralization in the next step and the molded body shape is maintained. Examples of the gas forming the oxidizing atmosphere at the time of infusibilization include air, ozone, oxygen, chlorine gas, bromine gas, ammonia gas, and mixed gas thereof.

As another infusibilizing method other than the above, a method of infusibilizing by γ-ray irradiation or electron beam irradiation while heating the molded body in an oxidizing atmosphere or a non-oxidizing atmosphere at low temperature as necessary is also adopted. be able to.

The purpose of irradiating with the γ ray or electron beam is to prevent the matrix from melting and losing the shape of the molded body by further polymerizing the polymer constituting the molded body.

The appropriate irradiation dose of gamma rays or electron beams is 10 ⁶ to 10 ¹⁰ rads.

Irradiation can be performed in a vacuum, an inert gas atmosphere, or an oxidizing gas atmosphere such as air, ozone, oxygen, chlorine gas, bromine gas, ammonia gas, or a mixed gas thereof.

The infusibilization by irradiation can be performed at room temperature, and if necessary, the infusibilization can be achieved by heating while heating in the temperature range of 50 to 200 ° C.

The infusibilized molded body can be vacuumed or in an inert gas.
It is mineralized by firing at a temperature in the range of 800-3000 ° C.

In the heating process, mineralization becomes severe from about 700 ℃,
It is estimated that mineralization is almost completed at about 800 ° C. Therefore, the firing is preferably performed at a temperature of 800 ° C. or higher. Moreover, since an expensive apparatus is required to obtain a temperature higher than 3000 ° C., firing at a temperature higher than 3000 ° C. is impractical in terms of cost.

The infusibilizing step can be omitted by extremely slowing the temperature rise rate of the mineralization in this step, using a shape-retaining jig, a shape-retaining means such as a powder head, or the like. Further, in the molding of the second step, the third step itself can be omitted by using the high temperature hot pressing method.

Fourth step: The carbonaceous inorganic material obtained in the third step is, if necessary, impregnated with a melt, a solution or a slurry of the metal-containing polycyclic aromatic polymer 3), and if necessary, rendered infusible and fired to be mineralized. This makes it possible to increase the density and strength of the carbonaceous inorganic material.

The impregnation may be performed by using a melt, a solution or a slurry of the metal polycyclic aromatic polymer 3). However, in order to permeate the fine open pores, the carbonaceous inorganic material is impregnated with the metal polycyclic aromatic polymer. After impregnating the solution or slurry of the group 3) polymer, the permeation of the micropores is promoted under reduced pressure, the temperature is raised while distilling off the solvent, and the pressure is increased to 10 to 500 kg / cm ² to obtain a metal polycyclic aromatic compound. The pores are filled with the melt of polymer 3).

The carbonaceous inorganic material impregnated with the metal polycyclic aromatic polymer 3) can be infusibilized, calcined and mineralized in the same manner as in the third step. By repeating this operation 2 to 10 times, a high-density, high-strength carbonaceous inorganic material can be obtained.

The existence state of Si, M, C, and O in the constituent component iii) can be controlled by the mineralization temperature in the third step and the fourth step.

That is, when it is desired to obtain an amorphous material consisting essentially of Si, M, C, and O, it is preferable to set the mineralization temperature to 800 to 1000 ° C. and substantially β-SiC, MC, and β-SiC. And MC solid solution and MC _1-x (where 0 <x <1) particle size 500Å
The following ultrafine particles and SiO _y (where 0 <y ≦ 2), MO
_When it is desired to obtain an amorphous material of _z (where 0 <z ≦ 2), a firing temperature of 1700 ° C. or higher is suitable.

Further, when a mixed system of each aggregate is desired, it can be appropriately selected from the above intermediate temperature.

Also, the amount of oxygen in the carbonaceous inorganic material of the present invention should be controlled by, for example, the selection of X in MX ₄ added in the first step, the addition ratio of MX ₄ and the infusibilizing conditions in the third step and the fourth step. You can

(Effects of the Invention) The carbonaceous inorganic material of the present invention contains silicon carbide and titanium carbide components which are extremely uniformly dispersed and integrated in carbon. The presence of these components promotes the microcrystallization of carbon at low temperature, suppresses the consumption due to the oxidation of carbon, and improves the hardness.

Therefore, this carbonaceous inorganic material is excellent in mechanical properties, oxidation resistance, and wear resistance, and is excellent as various brakes and heat resistant structural materials.

(Example) The present invention will be described below with reference to Examples.

Reference Example 1 (Production Method of Polymer I) 2.5 l of anhydrous xylene and 40 parts of sodium were placed in a 5 l three-necked flask.
0 g was added, the mixture was heated to the boiling point of xylene under a nitrogen gas stream, and 1 l of dimethyldichlorosilane was added dropwise over 1 hour. After completion of the dropping, the mixture was heated under reflux for 10 hours to form a precipitate. The precipitate was filtered, washed with methanol and then with water to obtain 420 g of white powdery polydimethylsilane.

400 g of this polydimethylsilane, a gas introduction tube, a stirrer,
Charge a 3 liter three-necked flask equipped with a condenser and a distillation tube,
Heat treatment was carried out at 420 ° C. under a nitrogen stream of 50 ml / min with stirring to obtain 350 g of a colorless transparent slightly viscous liquid in the distilling receiver.

The number average molecular weight of this liquid was 470 as measured by the vapor pressure osmosis method.

The infrared absorption spectrum of this substance was measured and found to be 65
Absorption of Si-CH ₃ at 0-900 cm ^-1 and 1250 cm ^-1 , Si at 2100 cm ^-1
Absorption of -H, Si-CH ₂ -Si absorption of of 1020 cm ^-1 and near 1355 cm ^-1, absorption of CH was observed at 2900 cm ^-1 and 2950 cm ^-1,
Further, when the far-infrared absorption spectrum of this substance was measured, absorption of Si-Si was observed at 380 cm ^-1 , and thus the obtained liquid substance was mainly composed of (Si-CH ₂ ) bond units and (Si-Si). It was found to be an organosilicon polymer having a bonding unit and having a hydrogen atom and a methyl group in the side chain of silicon.

From the results of nuclear magnetic resonance analysis and infrared absorption analysis, this organosilicon polymer shows that the total number of (Si—CH ₂ ) bond units is
It was confirmed that the polymer had a ratio of the total number of -Si) bond units of approximately 1: 3.

300 g of the above organosilicon polymer was treated with ethanol to remove low molecular weight substances, and 40 g of a polymer having a number average molecular weight of 1200 was obtained.

Measurement of the infrared absorption spectrum of this material, the absorption peak similar to that described above was observed, the material consists predominantly (Si-CH ₂₎ coupling units and (Si-Si) bond unit, hydrogen on the side chain of the silicon It was found to be an organosilicon polymer having atoms and methyl groups.

From the results of nuclear magnetic resonance analysis and infrared absorption analysis, this organosilicon polymer shows that the total number of (Si—CH ₂ ) bond units is
It was confirmed that the polymer had a ratio of the total number of -Si) bond units of about 7: 1. The organosilicon polymer obtained by removing the low molecular weight substances is referred to as organosilicon polymer A.

On the other hand, among petroleum fractions, high boiling point substances above light oil are
Fluid catalytic cracking / rectification was performed at a temperature of 500 ° C in the presence of an alumina cracking catalyst, and a residue was obtained from the bottom of the column. Hereinafter, this residue is referred to as FCC slurry oil.

As a result of elemental analysis, the FCC slurry oil had an atomic ratio of carbon atoms to hydrogen atoms (C / H) of 0.75 and an aromatic carbon ratio of 0.55 by nuclear magnetic resonance analysis.

500 g of the above FCC slurry oil was heated to 450 ° C. under a nitrogen gas stream, the distillate at the same temperature was distilled off, and the residue was filtered while hot at 200 ° C. to remove infusible parts at the same temperature and A minute removal pitch of 225 g was obtained.

The light content removal pitch was an optically isotropic pitch containing 75% xylene insoluble matter.

21 g of the above organosilicon polymer A and 20 ml of xylene were added to 49 g of this light content removal pitch, the temperature was raised with stirring, and xylene was distilled off, followed by reaction at 400 ° C. for 6 hours to obtain 39 g of a precursor polymer.

As a result of infrared absorption spectrum measurement, this precursor polymer was found to have Si-H bonds (IR: 2100 cm ^-1 ) present in the organosilicon polymer.
And the formation of a new Si-C (carbon of benzene ring) bond (IR: 1135cm ^-1 ) was observed, so that some of the silicon atoms of the organosilicon polymer were directly bonded to the polycyclic aromatic ring. It was found to be a copolymer having a portion.

Tetraoctoxytitanium [Ti (OC
₈ H ₁₇ ) ₄ ] 2.75 g of xylene solution (25% xylene solution 11
g) was added, xylene was distilled off, and the mixture was reacted at 340 ° C. for an hour to obtain 38 g of a random copolymer.

This copolymer did not contain a xylene-insoluble portion, had a weight average molecular weight of 1650 and a melting point of 272 ° C.

In parallel with this, 400 g of FCC slurry oil was heated to 450 ° C. under a nitrogen gas stream, the distillate at the same temperature was distilled off, and the residue was filtered while hot at 200 ° C. The portion was removed to obtain 180 g of a light material removal pitch. 180 g of the obtained light component removal pitch was subjected to polycondensation at 400 ° C. for 7 hours under a nitrogen stream while removing the light component produced by the reaction, to obtain a heat treated pitch of 85 g.

This heat treatment pitch has a melting point of 268 ° C, xylene insoluble content of 92%,
It contained 12% quinoline-insoluble matter, and the mesophase pitch was 89% with the optical anisotropy of the polished surface observed by a polarizing microscope.

35 g of the random copolymer and 70 g of the mesophase pitch
Are mixed and heated under a nitrogen atmosphere at 350 ° C. for 1 hour,
A polycyclic aromatic polymer containing silicon and titanium in a uniform state was obtained.

This polymer had a melting point of 272 ° C. and contained 59% xylene-insoluble matter.

Reference Example 2 (Production Method of Polymer II) To 39 g of the precursor copolymer obtained in Reference Example 1 was added an ethanol-xylene solution (1.5%) of 5.4 g of tetrakisacetylacetonatozirconium, and xylene and ethanol were distilled off. Polymerization was carried out at 0 ° C. for 1 hour to obtain 39.5 g of a zirconium-containing random copolymer.

20 g of this polymer and 50 g of mesophase pitch prepared in the same manner as in Reference Example 1 were finely pulverized and mixed, and melted at 350 ° C. in a spinning cylinder to obtain a zirconium-containing polycyclic aromatic polymer.

Reference Example 3 (Manufacturing Method of Polymer III) In the same manner as in Reference Example 1 except that the light content removal pitch and the usage amount of the organosilicon polymer A were changed to 50 g and 50 g, respectively.
57 g of precursor polymer was obtained.

An ethanol-xylene solution (1.5%) of 7.2 g of hafnium chloride was added to 40 g of this precursor copolymer, and xylene and ethanol were distilled off, followed by polymerization at 250 ° C. for 1 hour to obtain 43.5 g of a hafnium-containing random copolymer.

60 g of this polymer and 40 g of mesophase pitch were melt mixed at 320 ° C. to obtain a hafnium-containing polycyclic aromatic polymer.

Example 1 The polymer I powder obtained in Reference Example 1 was heated at 800 ° C. in a nitrogen stream.
The temperature was raised to 1, a calcined body was prepared, and this was finely pulverized to obtain a calcined body powder. Granulated powder obtained by adding an equal weight of the powder of Polymer I to the calcined powder and wet-mixing the mixture at 350 ° C. and 100 kg / cm ²
Hot pressing was performed to obtain a disk-shaped molded body having a diameter of 7 cm. This molded body was embedded in a carbon powder powder head and held in shape,
After raising the temperature to 800 ° C at a rate of 5 ° C / h in a nitrogen stream,
The temperature was raised to 300 ° C to make it inorganic. The obtained carbonaceous inorganic material had a bulk density of 1.52 g / cm ³ .

This carbonaceous inorganic material was dipped in a 50% xylene slurry of Polymer I, heated to 350 ° C while distilling off xylene under reduced pressure, and then pressure-impregnated to 100 kg / cm ² , followed by 5 ° C / in air.
The temperature was raised to 300 ° C. at a rate of h to infusibilize it, and then it was mineralized at 1300 ° C. This operation of impregnation and mineralization was repeated three more times to obtain a material having a bulk density of 1.96 g / cm ³ . The bending strength of this material is 2
It was 3 kg / mm ² . Further, when the carbonaceous inorganic material was baked at 2500 ° C. in argon, the bulk density was improved to 1.99 g / cm ³ and the bending strength was improved to 28 kg / mm ² . The bending strength at 1500 ° C in nitrogen was also 29 kg / mm ² .

Example 2 Using Polymer II, 30% of the powder of Polymer III obtained in Reference Example 3 was added to 70% of the calcined powder obtained in the same manner as in Example 1, and molded and mineralized in the same manner as in Example 1. Bulk density 1.72 g /
A carbonaceous inorganic material of cm ³ was obtained.

In the same manner as in Example 1, this material was impregnated with a 50% xylene slurry of Polymer II to be mineralized, and this impregnation and mineralization were repeated 3 times to obtain a carbonaceous inorganic material having a bulk density of 2.04 g / cm ³ . The bending strength of this material was 28 kg / mm ² , and no weight reduction or strength reduction was observed even after this material was kept in air at 600 ° C. for 24 hours.

Comparative Example 1 20% of mesophase pitch, which is an intermediate product of Reference Example 1, was added to 80% of artificial graphite powder having a bulk density of 0.15 g / cm ³ under no load, and molded in the same manner as in Example 1 to form an inorganic material. To obtain a carbon material having a bulk density of 1.66 g / cm ³ .

This carbon material was impregnated with mesophase pitch and mineralized in the same manner as in Example 1 four times to obtain a carbon material having a bulk density of 1.92 g / cm ³ .

The bending strength of this carbon material was 5.0 kg / mm ² , and when this carbon material was kept in air at 600 ° C. for 24 hours, a 20% weight loss was observed and it became porous.

Comparative Example 2 The carbon material having a bulk density of 1.66 g / cm ³ obtained in Comparative Example 1 was sprinkled with metallic silicon powder, melt-impregnated at 1500 ° C., and reaction-sintered to obtain a carbon-silicon carbide composite material. The bending strength of the obtained material is 8.
Although it was improved to ² kg / mm ² , when bending strength was measured at 1500 ° C in nitrogen, deformation occurred due to melting of unreacted silicon.
The bending strength dropped to 3.0 kg / mm ² .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Shibuya 5 1978, Kozugushi, Ube City, Yamaguchi Prefecture 5 Ube Kosan Co., Ltd.

Claims (1)

[Claims] 1. An inorganic material obtained from a metal-containing polycyclic aromatic polymer, the constituent components of which are: i) crystalline carbon derived from a polycyclic aromatic compound in a mesophase state which constitutes the polymer. Or crystalline carbon and amorphous carbon, ii) non-oriented crystalline carbon and / or amorphous carbon derived from the optically isotropic polycyclic aromatic compound constituting the polymer, and iii) Amorphous substance consisting essentially of Si, M, C and O, and / or substantially β-SiC, MC, solid solution of β-SiC and MC and MC
_{1-x is} an aggregate of crystalline ultrafine particles with a particle size of 500 Å or less and amorphous SiO _y and MO _z, and the ratio of constituent elements is Si; weight%,
C: 30-40 wt% and O: 0.01-30 wt% Si-MC
-O substance (in the above formula, M is at least one element selected from Ti, Zr, and Hf, and 0 <x <1, 0 <y ≦
2, 0 <z ≦ 2. ) A carbonaceous inorganic material characterized by comprising: