JPS6348827B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a molded article containing silicon, titanium, and carbon. Conventionally, regarding silicon carbide-containing molded bodies, JP-A-Sho
There are proposals in JP-A No. 53-94314, JP-A-54-3815, and JP-A-54-16521, etc., and it is disclosed that molded articles containing silicon carbide have good mechanical properties and thermal properties. ing. As a result of diligently continuing research on organometallic polymers, the present inventor has now succeeded in sintering a new organometallic polymer, polytitanocarbosilane, which can be obtained by sintering conventional polycarbosilane. The inventors have discovered that it is possible to obtain a molded product with even better performance than the silicon carbide-containing molded product, and have arrived at the present invention. That is, the molded body obtained by the method of the present invention is a molded body consisting essentially of Si, Ti, and C, and optionally further O, and the molded body substantially consists of (1) Si , amorphous consisting essentially of Ti and C and optionally further O, or (2) amorphous consisting essentially of β-SiC, TiC, a solid solution of β-SiC and TiC, and TiC _1-x (where O<x<1 ), or (3) a mixed system of the amorphous particles in (1) above and the crystalline ultrafine particles in (2) above. A molded article excluding fibers containing silicon, titanium, and carbon is provided. According to the present invention, as a method for producing the molded article containing silicon, titanium, and carbon, (1) mainly the general formula (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.) A polycarbosilane with a number average molecular weight of 200 to 10,000 and a main chain skeleton represented by the formula Ti(OR') ₄ A polytitanocarbosilane with a number average molecular weight of 700 to 100,000 derived from a titanium alkoxide represented by the formula (R' in the formula represents an alkyl group having 1 to 20 carbon atoms), At least a part of the silicon atoms of the polytitanocarbosilane are bonded to titanium atoms via oxygen atoms, and the total number of pairs of (-Si-CH ₂ )- structural units in the polytitanocarbosilane ( -Ti-O)- polytitanocarbosilane in which the ratio of the total number of structural units is within the range of 2:1 to 200:1, in vacuum, from an inert gas, a reducing gas, or a hydrocarbon gas. A first step of firing at a temperature range of 500 to 2300°C in an atmosphere consisting of at least one selected type, and (2) molding the obtained fired product, and at the same time or after the molding, in a vacuum, a second step of sintering silicon, titanium and A method of manufacturing a molded article excluding carbon-containing fibers is provided. The present invention will be explained in more detail below, but first the method of the present invention will be described. The starting material polytitanocarbosilane used in the method of the present invention mainly has the general formula (However, R in the formula is a hydrogen atom, a lower alkyl group,
or phenyl group) whose number average molecular weight has a main chain skeleton represented by
200 to 10,000 polycarbosilane and a titanium alkoxide represented by the general formula Ti(OR') ₄ (where R' in the formula represents an alkyl group having 1 to 20 carbon atoms). A polytitanocarbosilane having a number average molecular weight of 700 to 100,000, wherein at least a part of the silicon atoms of the polytitanocarbosilane are bonded to a titanium atom via an oxygen atom, and the polytitanocarbosilane The ratio of the total number of (-Si-CH ₂ )- structural units to the total number of (-Ti-O)- structural units in is 2:
1 to 200:1. In addition, such polymers include 1 as shown in the following figure.
There are functional polymers, difunctional polymers, trifunctional polymers and tetrafunctional polymers.

【formula】

【formula】

【formula】

[Formula] (However, R and R' have the same meanings as above)
In addition, the polytitanocarbosilane used in the present invention has a ratio of the polycarbosilane and the titanium alkoxide to the total number of (-Si-CH ₂ )- structural units of the polycarbosilane to the (-Ti- O
) - the ratio of the total number of structural units is 2:1 to 200:1
In addition to the quantitative ratio within the range of , it is obtained by heating the reaction in an atmosphere inert to the reaction. In the first step, the polytitanocarbosilane produced in this way is
500 to 2300℃ in an atmosphere consisting of at least one type selected from reducing gas and hydrocarbon gas.
It is semi-mineralized or mineralized by firing at a temperature range of . When the firing temperature is 500 to 800°C, a semi-mineralized fired product is mainly obtained, and when the firing temperature is 900 to 2300°C, a mineralized fired product is mainly obtained. Next, in a second step, the semi-mineralized and mineralized fired product is molded, and at the same time or after the molding, an inert gas, a reducing gas,
By sintering at a temperature range of 800 to 2300° C. in an atmosphere consisting of at least one kind selected from hydrocarbon gases, it is converted into a molded body containing Si, Ti, and C. Although there is no restriction on the shape of the semi-mineralized fired product and the mineralized fired product, it is usually preferable to crush these fired products into granules or powder before molding. Inert gases include nitrogen gas, carbon dioxide gas, argon gas, reducing gases include hydrogen gas and carbon monoxide gas, and hydrocarbon gases include methane gas,
Examples include ethane gas, propane gas, and butane gas. The sintering temperature is preferably 800 to 2300°C. If it is below 800°C, the inorganicization of the mixed polytitanocarbosilane will not be completed, and if it is above 2300°C, the SiC contained in the sintered product will decompose, so it is not preferable. . Note that, depending on the case, a honeycomb formed body can be obtained by performing the first step firing operation and the second step sintering operation simultaneously. Next, the method for sintering can be roughly divided into a method in which the fired product is molded and then sintered, or a hot press method in which the molding and sintering of the fired product are performed simultaneously. The method of performing the molding and sintering separately includes pressurizing with a pressure of 2 to 5000 kg/cm ² using a mold press method, a rubber press method, an extrusion method, or a sheet method to obtain a predetermined shape; Next, the molded body containing Si, Ti, and C of the present invention can be obtained by sintering the molded body. In addition, when performing sintering using the hot press method,
It is possible to select a mold made of graphite, alumina, boron nitride, etc., pressurize it with a pressure of 2 to 2000 kg/cm ² and heat it at the same time to form a sintered body. In a preferred embodiment of the present invention, the fired product of polytitanocarbosilane is previously subjected to acid-alkali treatment and/or heat treatment in an oxidizing gas atmosphere in a temperature range of 600 to 1300°C before being molded and sintered. do. The acid-alkali treatment agent includes hydrofluoric acid,
Sulfuric acid, hydrochloric acid, nitric acid, aqua regia, and caustic soda, caustic potash, etc. are used as the alkali, respectively. Further, as the oxidizing gas, oxygen, air, oxygen-containing gas, etc. are used. By performing such treatment, impurities such as trace amounts of oxygen-containing compounds or trace amounts of excess carbon are removed, and the resulting Si,
The density and strength of the Ti- and C-containing molded body are increased. Next, in a preferred embodiment of the present invention, the polytitanocarbosilane is mixed as a binder before the fired product of the polytitanocarbosilane is molded and sintered. By performing such an operation, a sintered compact with high density and high strength can be obtained. Furthermore, as a preferred embodiment of the present invention, the polytitanocarbosilane is mixed as a binder into the fired product of the polytitanocarbosilane, and before the mixture is molded and sintered, Calcining is performed at 800°C or lower in an atmosphere consisting of at least one selected from active gas, reducing gas, and hydrocarbon gas. By performing such a treatment, the volumetric shrinkage of the Si, Ti, and C-containing molded product is reduced, and a molded product with excellent dimensional accuracy can be obtained. Furthermore, as another preferred embodiment of the present invention, once sintering is completed by the method of the present invention,
A molded product containing Si, Ti, and C is impregnated with liquid polytitanocarbosilane by dipping, spraying, coating, etc., and if polytitanocarbosilane is obtained as a solid, heating or After making it into a liquid state by dissolving it in a solvent, it is impregnated by the above operation, and if necessary, after increasing the degree of impregnation by applying pressure, in a vacuum, an inert gas, a reducing gas, or a hydrocarbon gas is selected. By performing a series of heating treatments at least once in a temperature range of 800 to 2300° C. in at least one atmosphere, a sintered compact with higher density and higher strength can be obtained. The polytitanocarbosilane to be impregnated as described above needs to be in liquid form, so if it can be obtained in liquid form at room temperature or at a relatively low heating temperature, it can be used as is, or if necessary, a small amount of benzene, Toluene, xylene, hexane, ether, tetrahydrofuran, dioxane, chloroform, methylene chloride, petroleum ether, petroleum benzine, ligroin, Freon,
It can be put to practical use by dissolving it using DMSO, DMF, or other solvent that can dissolve polytitanocarbosilane. Next, the silicon-, titanium-, and carbon-containing molded article of the present invention (hereinafter sometimes referred to as the molded article of the present invention) will be explained. The molded article of the present invention consists essentially of Si, Ti, C or Si,
It is a molded body made of Ti, C, and O, and is produced by the method described above. It changes as shown in the following (A) to (C) depending on the conditions such as the heating and sintering temperature. (A) When the heating sintering temperature is relatively low, a substantially amorphous Si-, Ti- and C-containing compact is obtained; Mainly Si, Ti, C
or consisting of Si, Ti, C, or O. Generally speaking, if conditions are selected in the manufacturing process so that substantially no oxygen remains in the molded body obtained after heating and sintering, an amorphous substance consisting mainly of Si, Ti, and C will be produced.
On the other hand, if conditions are selected in the manufacturing process such that oxygen tends to remain in the compact after heating and sintering, an amorphous material mainly consisting of Si, Ti, C, and O will be produced. For example, when producing polytitanocarbosilane as a starting material, the more titanium alkoxide is used relative to the amount of polycarbosilane, the more oxygen remains in the molded product after heating and sintering. It becomes easier to do. In addition, oxygen is more easily removed when heat sintering is performed in a vacuum or in a reducing gas flow than in an inert gas flow such as nitrogen or argon. becomes difficult to remain. Furthermore, oxygen is more easily removed when heating and sintering is performed simultaneously with molding than when heating and sintering is performed after molding, so that oxygen is less likely to remain in the molded product after heating and sintering. For example, in Example (1-I) described below, all pairs of (-Si-CH ₂ )- bonds (-Ti
A polytitanocarbosilane in which the ratio of the total number of -O)- bonds is approximately 8:1 is fired at 1000°C in a _N2 stream, the polytitanocarbosilane is mixed with the fired product, molded, and _N2 Heating and sintering was carried out at 1000℃ in an air stream, and the molded body obtained in this case was
It is a molded body substantially made of amorphous material mainly composed of Si, Ti, C, and O. On the other hand, in Example 3 described later, (-Si-CH ₂ )- of the polycarbosilane moiety
After firing polytitanocarbosilane in which the ratio of the total number of bonds to the total number of (-Ti-O)-bonds is about 23:1 at 800°C under a (CO + N ₂ ) stream and pulverizing the fired product, The obtained powder was compacted and heated and sintered at 1000°C under a (CO + N ₂ ) air flow, but the compact obtained in this case was mainly
It is a molded body made essentially of an amorphous material made of Si, Ti, and C. (B) When the sintering temperature is high, β-SiC, TiC, a solid solution of β-SiC and TiC, and each crystalline superstructure of TiC _1-x (O<x<1) with a grain size of 500 Å or less A sintered compact consisting essentially of a fine particle aggregate is obtained. For example, the Si, Ti, and C-containing molded product described in Example (1-) below is obtained by heating the compacted product obtained in Example (1-I) at 1700°C in a _N2 stream. Although obtained by sintering, this compact is a sintered compact consisting of the above-mentioned crystalline ultrafine particle aggregates. The reason why a molded article having the above structure can be obtained when the firing temperature is high is as follows. The polytitanocarbosilane used as a starting material was
It is mineralized by heating and sintering, but at a stage where the sintering temperature is relatively low, the mineralized substance is
As mentioned in (A), mainly Si, Ti, C or
It is amorphous consisting of Si, Ti, C, and O, and has not yet reached the stage where crystalline ultrafine particles are generated. However, when the sintering temperature increases further,
Some of the above amorphous particles are β-SiC, TiC, solid solutions of β-SiC and TiC, and
When _the sintering temperature is high enough, substantially all of the amorphous particles become It is converted into the crystalline ultrafine particle aggregate. In the conversion to this crystalline ultrafine particle aggregate, especially the amorphous is mainly Si,
In the case of Ti, C, and O, as the sintering temperature rises, oxygen is gradually removed, and when the sintering temperature becomes high enough, most of the oxygen is removed, making it difficult for oxygen to remain in the compact. As a result, as in the case where the amorphous material is substantially composed of Si, Ti, and C, the molded body is transformed into a molded product substantially composed of the crystalline ultrafine particle aggregate. (C) If the sintering temperature is relatively high but does not reach the point where the conversion from amorphous to crystalline ultrafine particle aggregates is completed, the sintering temperature described in the previous section (A) may be used. Si, which consists of a mixed system of amorphous and crystalline ultrafine particle aggregates as described in the previous section (B),
A molded article containing Ti and C is obtained. As mentioned above, Si, Ti and C of the present invention
There are various forms of the containing molded bodies, and the molded bodies of each of these forms have structures as shown in types (A-1) to (C-2) below. (A-1) type: Si, Ti and C containing molded body,
It is substantially composed of an amorphous material consisting essentially of Si, Ti, and C. (A-2) type: Si, Ti and C containing molded body,
It is substantially composed of an amorphous material consisting essentially of Si, Ti, C, and O. Type (B): The molded body containing Si, Ti and C is substantially a solid solution of β-SiC, TiC, β-SiC and TiC, and
It is substantially composed of an aggregate of crystalline ultrafine particles of TiC _1-x (O<x<1) having a particle size of 500 Å or less. (C-1) type: Si, Ti and C containing molded body,
an amorphous substance consisting essentially of Si, Ti and C;
Substantially the particle size of β-SiC, TiC, solid solution of β-SiC and TiC, and TiC _1-x (where O<x<1)
It is composed of a mixed system of aggregates of crystalline ultrafine particles of 500 Å or less. (C-2) type: Si, Ti and C containing molded body,
An amorphous substance consisting essentially of Si, Ti, C and O, a solid solution consisting essentially of β-SiC, TiC, β-SiC and TiC, and a particle size of TiC _1-x (where O<x<1) It is composed of a mixed system of aggregates of crystalline ultrafine particles of 500 Å or less. To summarize the above, the Si and Ti identified in the present invention
In the method for producing a C-containing molded body, conditions are appropriately selected so that substantially no oxygen remains in the molded body obtained after heating and sintering, and when the sintering temperature is relatively low, A molded body with the structure of the type (A-1) above is obtained, and if the sintering temperature is set high enough, a molded body with the structure of the type (B) is obtained, and at an intermediate sintering temperature, a molded body with the structure of the type (C-1) is obtained. A molded body having the structure of the mold is obtained. On the other hand, if conditions are selected such that oxygen tends to remain in the compact obtained after sintering, and the sintering temperature is relatively low, a compact having the structure of type (A-2) can be obtained. If the sintering temperature is made high enough (B)
A molded body having a type structure is obtained, and at an intermediate sintering temperature, a molded body having a (C-2) type structure is obtained. Surprisingly, the Si-, Ti-, and C-containing molded product of the present invention has a mainly amorphous structure like the (A-1) type or (A-2) type, and even when the bulk density is small, it is extremely It has good strength and thermal properties, but generally has a structure consisting of type (B) crystalline ultrafine particle aggregates and has a large bulk density, which results in poor strength and other properties. properties are the best. (B) type, (C-1) type or (C-2) of the present invention
The crystalline ultrafine particles present in the Si-, Ti- and C-containing molded body with the structure of the mold are β-SiC, TiC, β-
Solid solutions of SiC and TiC and TiC _1-x (where O<x
<1) It can be confirmed from the X-ray diffraction pattern of the compact that it is composed of a composite carbide. () in the figure shows the structure of the present invention having the (B) type structure described in Example (1-) below.
It is an X-ray powder diffraction pattern of a molded article containing Si, Ti, and C. In this X-ray diffraction pattern (), the (111) diffraction line of β-SiC is located at 2Θ = 35.8°, and 2Θ =
The (220) diffraction line of β-SiC at 60.2° and the (311) diffraction line of β-SiC at 2Θ = 72.1°, and the (311) diffraction line of β-SiC at 2Θ = 42.4°.
(200) diffraction line of TiC, (111) of TiC at 2Θ=36.4°
Diffraction line, (220) diffraction line of TiC at 2Θ=61.4° and
The (113) diffraction line of TiC appears at 2Θ = 73.5°, and what is particularly noteworthy is that each diffraction line of TiC is at a higher angle than 2Θ of each diffraction line observed for conventional TiC. The TiC has shifted from the conventional
The lattice constant is different from TiC. The data of the X-ray diffraction pattern described above is based on the Si of the present invention,
The crystalline ultrafine particles present in the Ti- and C-containing molded body mainly consist of β-SiC and TiC, and β-SiC and TiC are in solid solution;
This indicates that it is a composite carbide that partially contains TiC _1-x (O<x<1). The Si-, Ti-, and C-containing molded product made of crystalline ultrafine particles of a specific composite carbide as described above is a novel molded product that has not been known until now. Moreover, the fact that the crystalline ultrafine particles are composed of such a composite carbide means that the Si,
This provides the advantage of imparting highly desirable superior performance to Ti and C containing molded bodies. That is, compared to β-SiC, TiC has properties such as significantly higher mechanical strength such as bending strength, tensile strength, and pressure strength.
has a property that its decomposition temperature in an oxidizing atmosphere is significantly higher than that of TiC. Si of the present invention,
The Ti- and C-containing molded product contains both TiC and β-SiC, and as is clear from the fact that both are partially dissolved, they are not intimately involved in the molded product of the present invention. Because TiC and β-SiC coexist in such a state, the favorable properties of both TiC and β-SiC are combined. Thus, the Si, Ti, and C-containing molded product of the present invention has better mechanical strength characteristics than the conventional molded product mainly composed of β-SiC, and has better mechanical strength characteristics than the molded product mainly composed of TiC. It is characterized by good oxidation resistance at high temperatures. Further, the crystalline fine particles made of the composite carbide present in the Si, Ti, and C-containing molded body of the present invention are ultrafine particles with an average particle size of 500 Å or less. For example, (C-
2) The average grain size of the crystalline ultrafine particles of the molded body with the type structure (sintering temperature 1200°C) is about 80 Å, and the molded body with the type (B) structure described in Example (1-) ( It was found by X-ray diffraction that it was approximately 160 Å at a sintering temperature of 1700°C. Usually, the Si, Ti and C-containing molded article of the present invention is
As the sintering temperature during production increases, the average crystal grain size in the compact increases. One of the reasons why the Si, Ti, and C-containing molded product of the present invention has extremely high strength is thought to be that it is composed of ultrafine crystals, and the reason is that local stress concentration causes Because it is dispersed through grain boundaries, it is difficult to deform; because the crystals are ultrafine particles, there is no room for the dislocations necessary for deformation to exist in the crystal grains; and because the crystal grain size is extremely small, the appearance of the grains is The surface tension of becomes abnormally large,
This is thought to be due to the fact that the resistance to deformation is large, and since the surface of the molded body is smooth and has no unevenness, there is no cause of decrease in strength due to concentration of stress on the uneven parts. The elemental ratios determined by chemical analysis of the Si-, Ti-, and C-containing molded product of the present invention, expressed in weight%, are generally Si: 30 to 60%, Ti: 0.5 to 35%, and C: 25 to 40%.
%, O: 0.01 to 20%. As is clear from the above, in the Si-, Ti- and C-containing molded article of the present invention obtained after heating and sintering,
The best results can be obtained if manufacturing conditions are selected that allow oxygen to remain easily.
Molded bodies containing as much as 20% by weight of oxygen can be obtained. That is, type (A-2) and type (C-2)
A molded body having a mold structure is a molded body containing a substantial amount of oxygen, but even these molded bodies can contain oxygen if the sintering temperature is high enough, as shown in Example 1 below. X is almost completely removed and converted into a shaped body having the type (B) structure consisting essentially of the crystalline ultrafine particle aggregate, and oxygen atoms are not involved in the formation of the crystalline ultrafine particles. This has been confirmed from the results of line diffraction. The Si-, Ti-, and C-containing molded product of the present invention is a molded product with a new structure that has excellent mechanical strength, heat resistance, and oxidation resistance, and takes advantage of these characteristics.
It can be used for various purposes as shown below. (1) Building materials - panels, domes, trailer houses, walls, ceiling materials, floor materials, cooling towers,
Septic tanks, sewage tanks, water supply tanks, hot water supply piping, drainage pipes, heat conversion heat pipes, etc. (2) Aircraft and space development equipment - fuselages, wings, helicopter drive shafts, jet engine compressors, rotors, stators , blades, complex casings, housings, nose cones, rocket nozzles, brake materials, tire cords, etc. (3) Marine materials - boats, yachts, fishing boats, work boats, etc. (4) Road transport equipment materials - front of vehicles Heads, side plates, water tanks, toilet units, seats, car bodies, containers, road equipment, guardrails, pallets, tanks for tank trucks, bicycles, motorcycles, etc. (5) Corrosion-resistant equipment materials - tanks, tower ducts, staffs, etc. , Pipes, etc. (6) Electrical materials - surface heating elements, varistors, igniters,
Thermocouples, etc. (7) Sports equipment - boats, bows, skis, snowmobiles, water skis, glider bodies, tennis rackets, golf shafts, helmets, butts, racing jackets, etc. (8) Mechanical elements - gaskets, packing, gears, brake materials, Wear materials, abrasive materials, etc. (9) Medical equipment materials - prosthetic legs, artificial limbs, etc. (10) Audio equipment materials - Can be used for cantilevers, tone arms, speaker cones, voice coils, etc. The present invention will be explained below with reference to Examples. Reference Example 1 2.5 g of anhydrous xylene and 400 g of sodium were placed in the three-necked flask of 15, heated to the boiling point of xylene under a nitrogen gas stream, and 1 dimethyldichlorosilane was added dropwise over 1 hour. After the dropwise addition was completed, the mixture was heated under reflux for 10 hours to form a precipitate. This precipitate was filtered and washed first with methanol and then with water to obtain 420 g of white powder polydimethylsilane. On the other hand, 750 g of diphenyldichlorosilane and 124 g of boric acid are heated at a temperature of 100 to 120°C in n-butyl ether under a nitrogen gas atmosphere, and the resulting white resinous material is further heated at 400°C in vacuum for 1 hour. This yielded 530 g of polyborodiphenylsiloxane. Next, 8.27 g of the above polyborodiphenylsiloxane was added and mixed to 250 g of the above polydimethylsilane, and the mixture was heated to 350°C under a nitrogen stream in a 2 quartz tube equipped with a reflux tube to polymerize for 6 hours. Carbosilane was obtained. After cooling at room temperature, add xylene to take out the solution, evaporate the xylene, and heat at 320℃.
Concentration for 1 hour under a stream of nitrogen gave 140 g of solid.
The number average molecular weight of this polymer was determined to be 995 by vapor pressure osmosis method (VPO method).
The IR spectrum of this substance was measured at 800 cm.
Absorption of Si−CH ₃ near ^-1 and 1250cm ^-1 , 1400,
C-H absorption at 2900, 2950cm ^-1 , Si- at 2100cm ^-1
H absorption, Si−CH ₂ − near 1020 cm ⁻¹ and 1355 cm ⁻¹
Absorption of Si was observed, and the resulting polymer showed that the constituent elements were

【formula】 【formula】

[Formula] It is a polycarbosilane having the following formula. Reference example 2 Weigh out 100g of tetramethylsilane, and use a recyclable flow-through device under a nitrogen atmosphere.
The reaction was carried out at 770°C for 24 hours to obtain polycarbosilane. After cooling at room temperature, normal hexane was added to take it out as a solution, and after removing insoluble matter by filtration,
Evaporate normal hexane and heat at 180℃ for 1 hour.
Concentration under reduced pressure of 5 mm Hg yielded 14 g of sticky material. The number average molecular weight of this polymer was 450 as measured by the VPO method. When the IR spectrum of this substance was measured, similar to Reference Example 1, various absorption peaks based on polycarbosilane were observed. Reference example 3 250g of polydimethylsilane obtained in reference example 1
was placed in an autoclave under an argon atmosphere.
Polycarbosilane was obtained by heating and polymerizing at 470°C under about 100 atm for 14 hours. After cooling at room temperature, add normal hexane to take out as a solution, evaporate normal hexane, concentrate at 280 ° C for 1 hour under reduced pressure of 1 mmHg, and treat the obtained solid with acetone to remove low molecular weight substances. As a result, 60 g of a polymer having a number average molecular weight of 8750 was obtained. When the IR spectrum of this substance was measured, similar to Reference Example 1, various absorption peaks based on polycarbosilane were observed. Example 1 40 g of polycarbosilane obtained in Reference Example 1 and 28 g of titanium tetrabutoxide were weighed, 400 ml of xylene was added to this mixture to make a mixed solution consisting of a homogeneous phase, and the mixture was heated at 130°C under a nitrogen gas atmosphere. The reflux reaction was carried out with stirring for 1 hour. After the reflux reaction was completed, the temperature was further raised to 200°C to distill off the xylene solvent, and then polymerization was carried out at 200°C for 1 hour to obtain polytitanocarbosilane. The number average molecular weight of this polymer was 1528 as measured by the VPO method. The polycarbosilane portion of this polymer (-Si-
Total number of pairs _{of CH2} )-bonds -O-Ti( _OC4H9 ) ₃ and (-
The ratio of the total number of Ti--O)- bonds is approximately 8:1.
This polymer was fired to 1000°C at a temperature increase rate of 200°C/hr in an N ₂ atmosphere, and the fired product was pulverized to 200 meshes or less. 90% by weight of this powder and 10% by weight of the above polymer were mixed with an appropriate amount of benzene, and after drying,
It was lightly crushed in a mortar and sieved with a 100 mesh sieve. This mixed powder was pressure molded at a molding pressure of 1000 Kg/cm ² to obtain a compacted powder body measuring 10 mm x 50 mm x 5 mm. Next, this powder compact was heated and sintered under three different conditions as shown in (I), (), and () below. (I): The above green compact was heated and sintered to 1000°C at a temperature increase rate of 200°C/hr in an N ₂ atmosphere. As a result, Si with a bulk density of 2.54 g/cm ³ and a bending strength of 16.5 Kg/mm ² ,
A molded article containing Ti and C was obtained. The X-ray powder diffraction measurement of this compact is shown in Figure (I). In (I) of the figure, almost no β-SiC and TiC diffraction lines are observed, and from the results of chemical analysis of this compact, the compact obtained under the heating sintering conditions of Example (1-I) The body is the above (A-
2) It was found that the molded product had a mold structure. (): The above compacted body was heated at 200℃/hr in an _N2 atmosphere.
It was heated and sintered to 1200℃ at a heating rate of . As a result, Si with a bulk density of 2.68g/cm ³ and a bending strength of 19.8Kg/mm ² ,
A molded article containing Ti and C was obtained. The X-ray powder diffraction measurement of the obtained compact is shown in () of the figure. Although it is broad in () in the figure, β−
From the fact that each diffraction line of SiC and TiC is observed (however, the 2Θ of each diffraction line of TiC is shifted to the high angle side) and the results of chemical analysis of this molded body, it is found that this example (1-) It was found that the molded body obtained under the heated sintering conditions had the structure of the above-mentioned (C-2) type. Furthermore, it was found by X-ray diffraction that the average particle size of the crystalline ultrafine particles present in the molded body was about 80 Å. (): The above compacted body was heated at 200℃/hr in an _N2 atmosphere.
It was heated and sintered to 1700℃ at a heating rate of . As a result, Si with a bulk density of 2.83g/cm ³ and a bending strength of 22.0Kg/mm ² ,
A molded article containing Ti and C was obtained. The X-ray powder diffraction measurement of the obtained compact is shown in () of the figure. Sharp β-SiC and
From the fact that each diffraction line peak of TiC is observed (however, the 2Θ of each diffraction line of TiC is shifted to the high angle side) and the results of chemical analysis of this compact, this Example (I-) is heated and sintered. It was found that the molded product obtained under the curing conditions had the structure of type (B). Furthermore, it was found by X-ray diffraction that the average particle size of the crystalline ultrafine particles present in the compact was about 160 Å. Example 2 The polymer obtained in Reference Example 1 was heated at 330°C for 3 hours.
The number average molecular weight obtained by concentrating under a nitrogen stream is
Weigh out 40.0 g of polycarbosilane 2990 and 65.3 g of titanium tetraisopropoxide, add 500 ml of benzene to this mixture to make a mixed solution consisting of a homogeneous phase, and stir the mixture at 70°C for 5 hours under an argon gas atmosphere. A reflux reaction was carried out. After the reflux reaction was completed, the benzene was distilled off and then heated at 150℃ for 2 hours.
Time polymerization was performed to obtain a Ti-containing organometallic polymer with a number average molecular weight of 8900. The obtained polymer was a uniform black-blue resinous material. The total number of (-Si-CH ₂ )- bonds in the polycarbosilane portion of this resin-like material vs. -O-Ti(O-isoC ₃ H ₇ ) ₃ and (-Ti-O
) - the ratio of the total number of bonds is approximately 3:1. This polymer was fired in vacuum (10 ^-3 mmHg) at a heating rate of 100°C/hr to 800°C, and the fired product was pulverized into 200 meshes or less. This powder was set in a carbon die, and a pressure of 250 kg/cm ² was applied from the beginning at room temperature, and hot-pressed at 2000° C. for 0.5 hour in an Ar flow. As a result, the bulk density was 3.10g/cm ³ and the bending strength was 40.8.
A sintered compact of Kg/mm ² was obtained. It was found from the results of X-ray powder diffraction measurement and chemical analysis that the molded product obtained here had the structure of type (B). Example 3 40 g of polycarbosilane obtained in Reference Example 2 and 10 g of titanium tetrabutoxide were weighed out, 300 ml of normal hexane was added to this mixture to form a mixed solution consisting of a homogeneous phase, and the mixture was heated at 60°C under a nitrogen gas atmosphere. 8
The reflux reaction was carried out while stirring for hours. After the reflux reaction was completed, the mixture was further heated to distill off normal hexane, and then polymerized at 170°C for 3 hours to obtain polytitanocarbosilane with a number average molecular weight of 1450. The total number of (-Si-CH ₂ )- bonds in the polycarbosilane moiety of this polymer versus -O-Ti(OC ₄ H ₉ ) ₃ and (-Ti-O)-
The ratio of the total number of bonds is approximately 23:1. This polymer was fired in a CO+N ₂ [CO:N ₂ = 1:4 (molar ratio)] atmosphere at a temperature increase rate of 200°C/hr to 800°C, and the fired product was pulverized to 200 meshes or less. This powder was pressure-molded at a molding pressure of 2000 kg/cm ² to obtain a compacted powder body measuring 10 mm x 50 mm x 5 mm. This compacted compact is CO+N ₂ [CO:N ₂ = 1:4 (molar ratio)]
The material was heated and sintered to 1000°C in an atmosphere at a heating rate of 100°C/hr. As a result, a molded article containing Si, Ti, and C was obtained with a bulk density of 2.46 g/cm ³ and a bending strength of 12.0 Kg/mm ² . From the results of X-ray powder diffraction measurement and chemical analysis, it was found that the molded product obtained here had the structure of the type (A-1) described above. Example 4 40.0 g of polycarbosilane obtained in Reference Example 3 and 1.6 g of titanium tetraisopropoxide were weighed,
Add 200 ml of xylene to this mixture to make a mixed solution consisting of a homogeneous phase.
The reflux reaction was carried out with stirring at °C for 2 hours. After the reflux reaction was completed, the mixture was further heated to distill off xylene, and then polymerized at 300°C for 30 minutes to obtain polytitanocarbosilane with a number average molecular weight of 18,500. The polycarbosilane portion of this polymer (-Si-CH ₂
The ratio of _the total number of )- bonds to the total number of -O-Ti(O- _isoC3H7 ) ₃ and (-Ti-O)- bonds is approximately 122:1. This polymer was fired to 1800°C at a heating rate of 200°C/hr in an Ar atmosphere, and the fired product was further heated to 700°C at a heating rate of 300°C/hr in air to remove excess carbon. After removing it, it was crushed to less than 200 mesh pieces. 80% by weight of this powder and the polymer
20% by weight was mixed with an appropriate amount of n-hexane, dried, and then ground. This mixed powder was pressure-molded at a molding pressure of 3000 Kg/cm ² to obtain a powder compact measuring 10 mm x 50 mm x 5 mm. This powder compact was heated at 100℃/in an Ar atmosphere.
The material was heated and sintered to 1200℃ at a heating rate of hr. As a result, Si has a bulk density of 2.60 g/cm ³ and a bending strength of 18.3 Kg/mm ² .
A molded article containing Ti and C was obtained. From the results of X-ray powder measurement and chemical analysis, it was found that the molded body obtained here had the structure of the above-mentioned (C-1) type. Example 5 The polytitanocarbosilane obtained in Example 2 was heated to 500°C at a temperature increase rate of 100°C/hr in an N ₂ atmosphere.
The fired product was pulverized to 200 mesh or less. 85% by weight of this powder and 15% by weight of the polymer were mixed with an appropriate amount of xylene, dried, and then calcined to 700°C at a heating rate of 100°C/hr in an N ₂ atmosphere.
The calcined product was pulverized. 90% by weight of this calcined powder,
10% by weight of the polymer was further mixed with an appropriate amount of xylene, dried, and then ground. Add this mixed powder to 2000
Pressure molded with a molding pressure of Kg/cm ² to 10mm x 50mm x 5mm.
A powder compact was obtained. This powder compact was heated and sintered to 1400°C at a temperature increase rate of 200°C/hr in an N ₂ atmosphere. As a result, the bulk density was 2.86g/cm ³ and the bending strength was
A molded article containing Si, Ti and C with a weight of 30.5 Kg/mm ² was obtained.
From the results of X-ray powder diffraction measurement and chemical analysis, it was found that the compact obtained here had the above-mentioned (C-2) type structure [close to the (B) type structure]. . Example 6 The sintered compact obtained in Example (I-) was immersed in a benzene solution of the polytitanocarbosilane used in Example 1 with a concentration of 1 g/ml to obtain an impregnated compact. After drying, it was heated and sintered in N ₂ at a temperature increase rate of 200°C/hr to 1800°C. As a result of performing this series of impregnation, drying, and heating sintering twice, a molded article containing Si, Ti, and C having a bulk density of 3.01 g/cm ³ and a bending strength of 36.5 Kg/mm ² was obtained. The obtained molded body is
From the results of line powder diffraction measurement and chemical analysis, the above
It was found that the molded product had a structure of type (B).

[Brief explanation of drawings]

(I), () and () of the drawings show the X-ray powder diffraction patterns of the Si, Ti and C containing molded bodies obtained in Examples (1-I), (1-) and (1-). .

Claims (1)

[Claims] 1 (1) Mainly general formula (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.) A polycarbosilane with a number average molecular weight of 200 to 10,000 and a main chain skeleton represented by the formula Ti(OR') ₄ (However, R' in the formula represents an alkyl group having 1 to 20 carbon atoms.)
700 to 100,000 polytitanocarbosilane, at least a part of the silicon atoms of the polytitanocarbosilane are bonded to titanium atoms via oxygen atoms, and (- The ratio of the total number of structural units of Si-CH ₂ )- to the total number of structural units of (-Ti-O)- is 2:1
Polytitanocarbosilane having a ratio of 1 to 200:1 is heated in a temperature range of 500 to 2300°C in vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. and (2) forming the obtained fired product, and at the same time or after the shaping, at least one kind selected from inert gas, reducing gas, and hydrocarbon gas in a vacuum. A method for producing a silicon-, titanium-, and carbon-containing molded article, comprising a second step-a of sintering at a temperature range of 800 to 2,300°C in an atmosphere consisting of: 2 (1) Mainly general formulas (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.) A polycarbosilane with a number average molecular weight of 200 to 10,000 and a main chain skeleton represented by the formula Ti(OR') ₄ (However, R' in the formula represents an alkyl group having 1 to 20 carbon atoms.)
700 to 100,000 polytitanocarbosilane, at least a part of the silicon atoms of the polytitanocarbosilane are bonded to titanium atoms via oxygen atoms, and (- The ratio of the total number of structural units of Si-CH ₂ )- to the total number of structural units of (-Ti-O)- is 2:1
Polytitanocarbosilane having a ratio of 1 to 200:1 is heated in a temperature range of 500 to 2300°C in vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. (first step) (2) The fired polytitanocarbosilane obtained in the first step is subjected to acid-alkali treatment and/or
Alternatively, heat treatment is performed in an oxidizing gas atmosphere at a temperature range of 600 to 1300°C, and then the resulting treated product is molded, and at the same time or after this molding,
A second step-b of sintering in vacuum at a temperature range of 800 to 2300°C in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. A method for producing a molded article containing silicon, titanium, and carbon. 3 (1) Mainly general formulas (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.) A polycarbosilane with a number average molecular weight of 200 to 10,000 and a main chain skeleton represented by the formula Ti(OR') ₄ (However, R' in the formula represents an alkyl group having 1 to 20 carbon atoms.)
700 to 100,000 polytitanocarbosilane, at least a part of the silicon atoms of the polytitanocarbosilane are bonded to titanium atoms via oxygen atoms, and (- The ratio of the total number of structural units of Si-CH ₂ )- to the total number of structural units of (-Ti-O)- is 2:1
Polytitanocarbosilane having a ratio of 1 to 200:1 is heated in a temperature range of 500 to 2300°C in vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. (2) The polytitanocarbosilane used in the first step is mixed with the fired polytitanocarbosilane obtained in the first step, and then the polytitanocarbosilane obtained in the first step is mixed. At the same time or after the molding, the mixture is molded at a temperature of 800 to 2300°C in a vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. 1. A method for producing a silicon-, titanium-, and carbon-containing molded article, characterized by comprising a second step-c of sintering within a range. 4 (1) Mainly general formulas (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.) A polycarbosilane with a number average molecular weight of 200 to 10,000 and a main chain skeleton represented by the formula Ti(OR') ₄ (However, R' in the formula represents an alkyl group having 1 to 20 carbon atoms.)
700 to 100,000 polytitanocarbosilane, at least a part of the silicon atoms of the polytitanocarbosilane are bonded to titanium atoms via oxygen atoms, and (- The ratio of the total number of structural units of Si-CH ₂ )- to the total number of structural units of (-Ti-O)- is 2:1
Polytitanocarbosilane having a ratio of 1 to 200:1 is heated in a temperature range of 500 to 2300°C in vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. (1st step); (2) the polytitanocarbosilane used in the first step is mixed with the fired product of the polytitanocarbosilane obtained in the first step; The mixture is heated under vacuum, inert gas, reducing gas,
At least one selected from hydrocarbon gases
The calcined product is calcined at 800°C or less in an atmosphere consisting of seeds, and then the calcined product obtained is molded, and at the same time or after the molding, it is heated in a vacuum with an inert gas, a reducing gas, or a hydrocarbon gas. 800 to 2300℃ in an atmosphere consisting of at least one selected
A method for producing a silicon-, titanium-, and carbon-containing molded article, characterized by comprising a second step -d of sintering at a temperature range of .