JPS6237050B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel organometallic crosslinked block copolymer comprising a polycarbosilane moiety and a polyzirconosiloxane moiety. Polycarbosilane, which is a polymer whose main chain skeleton consists of (-Si-CH ₂ )- and two side chain groups bonded to each silicon atom, is converted into an inorganic carbide SiC by baking, so polycarbosilane It is well known that SiC fibers with good mechanical and thermal properties can be produced by forming SiC fibers into fibers and firing them.
It was disclosed in the specification of No. 126300, the specification of JP-A-51-139929, etc. The inventor subsequently discovered that the main chain skeleton was mainly (-Si
Organometallic combination of polycarbosilane consisting of the structural unit -CH ₂ )- and polytitanosiloxane having titanoxane bonding units (-Ti-O)- and siloxane bonding units (-Si-O)- in the main chain skeleton. SiC- obtained by spinning, infusible and firing copolymer
It was disclosed in Japanese Patent Application No. 54-80793 that Tic fibers have even better mechanical properties than SiC fibers. As a result of diligently continuing research on organometallic copolymers, the present inventor discovered a new crosslinked block copolymer consisting of a crosslinked polycarbosilane moiety and a polyzirconosiloxane moiety.
Moreover, when this organometallic copolymer is molded and fired, it becomes different from that obtained from conventional polycarbosilane.
It has been found that ZrC-SiC fibers can be obtained which exhibit better mechanical properties and oxidation resistance at high temperatures than SiC fibers, making it an extremely useful polymer. According to the present invention, the polycarbosilane moiety (A) has a number average molecular weight of about 500 to 10,000 and a number average molecular weight of about 500.
-10,000 polyzirconosiloxane moiety (B) and a number average molecular weight of about 1,000 to 50,000; the polycarbosilane moiety (A) mainly has the formula (-Si-CH ₂ ) - has a main chain skeleton consisting of the structural unit, and the silicon atom in the formula has a side chain group selected from the group consisting of a hydrogen atom, a lower alkyl group (preferably having 1 to 4 carbon atoms), and a phenyl group. The polyzirconosiloxane moiety (B) has one or two zirconoxane bonding units (-Zr
It has a main chain skeleton in which -O)- and siloxane bond units (-Si-O)- are randomly bonded, and the ratio of the total number of zirconoxane bonds to the total number of siloxane bonds is 30:1 to 1:30. within the range, and most of the silicon atoms in the siloxane bond have one or two side chain groups selected from the group consisting of lower alkyl groups (preferably having 1 to 4 carbon atoms) and phenyl groups. , most of the zirconium atoms in the zirconoxane bond have one or two lower alkoxy groups (preferably having 1 to 4 carbon atoms), phenoxy groups or acetylacetoxy groups as side chain groups; the polycarbosilane At least a portion of the silicon atoms in moiety (A) are present in the polyzirconosiloxane moiety (B).
is bonded to at least a portion of the silicon atoms and/or zirconium atoms of via oxygen atoms, thereby crosslinking the polycarbosilane moiety (A) and the polyzirconosiloxane moiety (B), and Ratio of the total number of (-Si-CH ₂ )- structural units in the polycarbosilane moiety (A) to the total number of (-Zr-O)-bonding units and (-Si-O)- bonding units in the polyzirconosiloxane moiety is 100:1
The organometallic crosslinked block copolymer is within the range of 1:100; melts by heating at 50 to 400°C, and is compatible with organic solvents. The organometallic copolymer of the present invention (1) has a main chain skeleton mainly composed of structural units of the formula (-Si-CH ₂ )- with a number average molecular weight of about 500 to 10,000, The atoms include essentially two side chain groups selected from the group consisting of hydrogen atoms, lower alkyl groups (preferably having 1 to 4 carbon atoms), and phenyl groups.
and (2) a main clavicle in which zirconoxane bonding units (-Zr-O)- and siloxane bonding units (-Si-O)- having a number average molecular weight of approximately 500 to 10,000 are randomly bonded. and the ratio of the total number of zirconoxane bond units to the total number of siloxane bond units is within the range of 30:1 to 1:30, and most of the silicon atoms of the siloxane bond units are lower alkyl groups (carbon number 1 to 4) and phenyl groups, and most of the zirconium atoms in the zirconoxane bonding unit have lower alkoxy groups (carbon (preferably number 1 to 4), a polyzirconosiloxane having one or two phenoxy groups or acetylacetoxy groups is combined with the total number of (-Si-CH ₂ )- structural units of the polycarbosilane to the polyzirconosiloxane. The ratio of the total number of (-Zr-O)-bonding units and (-Si-O)-bonding units is 100:
Mix at a ratio within the range of 1 to 1:100,
The resulting mixture is heated in an organic solvent and under an atmosphere inert to the reaction to convert at least a portion of the silicon atoms of the polycarbosilane into silicon atoms of the polyzirconosiloxane and/or A polycarbosilane moiety and a polyzirconosiloxane moiety having a number average molecular weight of 1000 to 1,000, which are composed of a crosslinked polycarbosilane moiety and a polyzirconosiloxane moiety, which are bonded to at least a portion of zirconium atoms via an oxygen atom.
50,000 can be produced by the method for producing organometallic crosslinked block copolymers. Below, the organometallic crosslinked block copolymer of the present invention (hereinafter sometimes simply referred to as organometallic copolymer) and the method of producing the same will be explained in more detail. The organometallic copolymer of the present invention is a crosslinked block copolymer obtained by crosslinking polycarbosilane and polyzirconosiloxane by block copolymerization. A typical block copolymer is obtained by bonding each block to each other at each end, and therefore has a structure consisting of a series of blocks connected by head-to-tail bonds. On the other hand, in the organometallic copolymer of the present invention, a part of the silicon atoms of the structural unit (-Si-CH ₂ )- present in the middle of the main chain skeleton of the polycarbosilane moiety is Therefore, a structure in which a structural unit (-Si-O- and/or -Zr-O-) existing in the middle of the main chain skeleton of the polyzirconosiloxane moiety is bonded to a part of the silicon atom and/or zirconium atom is formed. It is something that you have. That is, the organometallic copolymer of the present invention has a polycarbosilane moiety.
It is a crosslinked block copolymer with a unique structure in which (A) and the polyzirconosiloxane moiety (B) are not bonded head to tail, but are crosslinked in the middle of the main chain bonds. Although polycarbosilane itself and polyzirconosiloxane themselves are known polymers, a copolymer consisting of carbosilane and zirconosiloxane has not been known so far. Needless to say, a crosslinked block copolymer in which polycarbosilane and polyzirconosiloxane are bonded in the above-mentioned unique bonding manner has never been known, and therefore, the organometallic copolymer of the present invention Coalescence is a new polymer. The fact that the organometallic copolymer of the present invention is a crosslinked block copolymer consisting of a polycarbosilane moiety and a polyzirconosiloxane moiety can be confirmed by gel permeation chromatography (GPC) and infrared absorption spectrum (IR). ) can be confirmed. Figure 1 shows GPC of polycarbosilane obtained by the method of Reference Example 1 described below, Figure 2 shows GPC of polyzirconosiloxane obtained by the method of Reference Example 2 described later, and Figure 3 shows the GPC of polycarbosilane obtained by the method of Reference Example 2 described later. GPC of the organometallic copolymer of the present invention obtained by reacting the above polycarbosilane and polyzirconosiloxane in a weight ratio of 1:1 according to the method of Example 1.
(In each case, a solution of 50 mg of polymer dissolved in 10 ml of tetrahydrofuran was used for measurement.) Figure 4 also shows a simple mixture of the above polycarbosilane and polyzirconosiloxane (weight ratio 1:1). (The solution used for the measurement was 50 mg of a polymer mixture consisting of 25 mg of each polymer dissolved in 10 ml of tetrahydrofuran).
The simple mixture of two polymers shown in Figure 4
The GPC matches the superposition of the GPC in Figure 1 and the GPC in Figure 2. However, in the GPC of the copolymer shown in FIG. 3, a new peak that is not seen in any of the GPCs in FIGS. 1, 2, and 4 appears at an elution volume of 8.1 ml on the horizontal axis. This means that the molecular weight has increased due to block copolymerization of polycarbosilane and polyzirconosiloxane (in GPC, the lower the value on the horizontal axis (elution amount) of the peak, the higher the molecular weight is high). Also, the GPC in Figures 1 and 2
Focusing on the peak at an elution volume of 10 ml, the height of this peak is extremely small in the GPC shown in Figure 3. This means that the content of low molecular weight substances in the block copolymer was significantly reduced. As mentioned above, the GPC experimental results show that the organometallic polymer of the present invention is not a mere mixture of polycarbosilane and polyzirconosiloxane, but is a block compound with a high molecular weight due to the combination of the above two types of polymers. This indicates that it is a polymer. Next, to explain the infrared absorption spectra (IR), Figure 5 shows the IR of the polycarbosilane described in Reference Example 1, Figure 6 shows the IR of the polyzirconosiloxane described in Reference Example 2, and Figure 7 shows the IR of the polycarbosilane described in Reference Example 1. 1 is an IR of the organometallic copolymer of the present invention described in Example 1. The absorptions at 1250 cm ^-1 and 2100 cm ^-1 in the IR in Figure 5 are absorptions corresponding to Si-CH ₃ and Si-H present in the polycarbosilane starting material, respectively (polyzircon in Figure 6). In the IR of siloxane, these absorptions are not present). In the IR of the copolymer shown in Figure 7, the above two absorptions exist, but the Si-H absorption intensity (2100 cm ^-1 /Si-C
Comparing Figures 5 and 7 with respect to the ratio of H ₃ absorption intensity (1250 cm ^-1 ), the ratio is 0.608 in the IR of Figure 5, while it is considerably reduced to 0.456 in Figure 7. ing. This is due to the reaction between polycarbosilane and polyzirconosiloxane.
This shows that some of the -H bonds disappear, thereby resulting in a block copolymer of polycarbosilane and polyzirconosiloxane. That is, the organometallic copolymer (block copolymer) of the present invention is
Some of the hydrogen atoms bonded as side chain groups to the silicon atoms of the structural unit (-Si-CH ₂ )- present in the main chain skeleton of polycarbosilane are removed, and the silicon atoms are converted into polyzirconosiloxane. Structural units present in the main chain skeleton (-Si-O- and/or -Zr-O
-) is produced by crosslinking with part of the silicon atoms and/or zirconium atoms via oxygen atoms. Based on the above IR data, the crosslinking rate of the organometallic copolymer of Example 1 is calculated to be 25.0% (assuming that crosslinking occurs only due to the disappearance of Si--H bonds). The method of the present invention for producing the organometallic copolymer of the present invention comprises heating a mixture of polycarbosilane and polyzirconosiloxane in an organic solvent and under an atmosphere inert to the reaction, This is a method in which at least part of the silicon atoms of polycarbosilane is bonded to at least part of the silicon atoms and/or zirconium atoms of polyzirconosiloxane via oxygen atoms. The organic solvent is used to carry out the reaction smoothly and to suppress the production of by-products such as gel-like substances, and preferred solvents include benzene, toluene, xylene, tetrahydrofuran, and the like. In addition, it is necessary to carry out the reaction in an atmosphere of an inert gas (e.g. nitrogen, argon, hydrogen, etc.), and if it is carried out in an oxidizing atmosphere such as air, This is not preferred because oxidation of silane and polyzirconosiloxane occurs. The reaction temperature can be varied over a wide range; for example, it may be heated to a temperature below the boiling point of the organic solvent used, but if a copolymer with a high crosslinking rate is to be obtained, it may be heated to a temperature above the boiling point of the organic solvent. It is preferable to carry out the crosslinking reaction by heating to distill off the organic solvent. The reaction temperature is generally preferably 500°C or lower. The reaction time is not particularly important, but it is usually 1~
It takes about 10 hours. It is generally preferable to carry out the reaction near normal pressure, and it is not preferable to carry out the reaction in vacuum or under high reduced pressure because low molecular components will distill out of the system and the yield will decrease. In order to carry out the method of the present invention, it is preferable to carry out the reaction while feeding an inert gas into the reaction section as a gas stream. This is because it is possible to prevent a pressure increase due to a hydrocarbon gas, such as a gas such as methane, released during the reaction. In the method of the present invention, the polycarbosilane used as one of the starting materials for producing the organometallic copolymer has a number average molecular weight of about 500 to 10,000.
has a main chain skeleton mainly consisting of structural units of the formula (-Si-CH ₂ )-, in which the silicon atom is substantially a hydrogen atom, a lower alkyl group, and a phenyl group. It is a polycarbosilane having two chain groups. In addition to the above-mentioned side chain groups, an OH group may be bonded to the silicon atom of the terminal group of polycarbosilane. The method for producing polycarbosilane itself is well known;
The above polycarbosilane used as a starting material in the present invention can be produced by such known methods. For example, a method for producing polycarbosilane by directly polymerizing monosilane is described by Fritz; Angew.Chem., 79 p.657.
(1967), and a method for producing polycarbosilane by once converting monosilane into polysilane and then polymerizing it is disclosed in Japanese Patent Application Laid-Open No. 51-126300 filed by the present applicant. This method is disclosed in Japanese Patent Laid-Open Publication No. 112700/1983. Among the polycarbosilanes used in the present invention, polycarbosilanes whose main chain skeleton consists essentially only of (-Si-CH ₂ )- structural units can be produced by the above-mentioned known method. . A polycarbosilane particularly suitable for use as a starting material in the present invention is a modified polycarbosilane produced by the method described in JP-A-54-61299, filed by the applicant. , that is, it is a polycarbosilane partially containing siloxane loading. This modified polycarbosilane mainly consists of the following structural units (A) and (B),

【formula】

[Formula] (Here, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a lower alkyl group or a phenyl group) The ratio of (A) and (B) is 5:1 to 200: 1, and is a polycarbosilane partially containing siloxane bonds with a number average molecular weight of 500 to 10,000. This modified polycarbosilane is

For polysilane having the structure [formula] (where n≧3, R ₁ and R ₂ have the same meanings as above), the skeleton components are B, Si and O, and at least one of the side chains of Si is 0.01 to 15% by weight of polyborosiloxane having a phenyl group is added and mixed, and the polymer mixture is heated at usually 250°C or higher, preferably 300 to 500°C in an atmosphere inert to the reaction. Usually 8~
It can be produced by polymerizing for 10 hours. In the method of the present invention, the polyzirconosiloxane used as another starting material for producing the organometallic copolymer has a number average molecular weight of about 500 to
It has a main chain skeleton consisting of 10,000 zirconoxane bond units (-Zr-O)- and siloxane bond units (-Si-O)-, and the ratio of the total number of zirconoxane bond units to the total number of siloxane bond units is 30: 1 to 1:30, most of the silicon atoms of the siloxane bonding unit have one or two side chain groups selected from the group consisting of lower alkyl groups and phenyl groups, and Most of the zirconium atoms in the zirconoxane bonding units are polyzirconosiloxanes having one or two lower alkoxy groups, phenoxy groups, or acetylacetoxy groups as side chain groups. In addition to the above-mentioned side chain groups, an OH group may be bonded to the silicon atom or zirconium atom present as a terminal group of polyzirconosiloxane. The method for producing polyzirconosiloxane itself is known, and the above polyzirconosiloxane used as a starting material in the present invention can be produced by such a known synthesis method. Typical synthesis methods include (a) a synthesis method by cohydrolysis of organochlorosilane and zirconium alkoxide, zirconium phenoxide or zirconium acetylacetonate, and (b) a dehydrochloric acid condensation reaction of organosilanol and zirconium chloride. Synthesis method or (c) synthesis method by dealcoholization condensation reaction of organosilanol and zirconium alkoxide, zirconium phenoxide or zirconium acetylacetonate. When synthesizing the polyzirconosiloxane used in the present invention by the synthesis methods (a) to (c) above, -Si
The formation of the -O-Ti-O- bond is expressed as follows. (stomach)

[Formula] (b) -SiOH+-TiC→ -Si-O-Ti-+HC (c) -SiOH+-TiOR→ Si-O-Ti-+ROH The synthesis method for polyzirconosiloxane is, for example,
Inorganic Polymers (FGAStone Academic
Press. 1962), and also in the specification of Japanese Patent Application No. 58004/1983 filed by the applicant. The polyzirconosiloxane used as a starting material in the present invention has a number average molecular weight of 500 to 10,000,
It is a polymer that is soluble in organic solvents (eg, benzene, toluene, xylene, acetone, tetrahydrofuran, etc.). In this specification, the siloxane bonding unit present in the main chain skeleton is expressed by the simplified formula (-Si-O)- according to the conventional writing method, but as is well known to those skilled in the art,
The siloxane bonding unit represented by the above formula is a difunctional group.

[Formula] Three-tube functional group

[Formula] and tetrafunctional group

It includes three types of siloxane bonding units: ##STR1## where R is a side chain organic group. and these 3
Any of the siloxane bonding units of the species can be a structural unit forming the main chain skeleton of the polyzirconosiloxane used in the present invention. However,
As the content of tetrafunctional siloxane bonding units increases, the polymer generally becomes rich in crosslinked structures and becomes insoluble in organic solvents. It is necessary that the moieties be difunctional or trifunctional siloxane bonding units, with small amounts of tetrafunctional siloxane units. Therefore,
In the polyzirconosiloxane used as a starting material in the present invention, most of the silicon atoms in the siloxane bonding unit (-Si-O)- have one or two side chain organic groups R (lower alkyl group or phenyl group). should be combined. That is, the polyzirconosiloxane used in the present invention may contain a small amount of tetrafunctional siloxane bonding units, but the content must be within a limit that does not inhibit the solubility of the polymer in organic solvents. The polyzirconosiloxane linking units used in the present invention are substantially difunctional and/or
Or, it is preferable that it consists of a trifunctional siloxane bonding unit. Similarly to the above, the zirconoxane bonding unit represented by the formula (-Zr-O)- can also be a difunctional group, a trifunctional group,
However, for the same reason as stated above, most of the zirconoxane bonds in the polyzirconosiloxane used in the present invention contain side chain organic groups (lower alkoxy groups, phenoxy groups, or acetyl groups). acetoxy groups) (difunctional group) or one (trifunctional group), and the zirconoxane bonding unit is substantially difunctional and/or Or a trifunctional zirconoxane bonding unit is preferred. In the polyzirconosiloxane used in the present invention, the ratio of the total number of zirconoxane bonds to the total number of siloxane bonds is within the range of 30:1 to 1:30. The polyzirconosiloxane used in the present invention is
It is a polymer consisting of a skeleton in which siloxane bonds (-Si-O)- and zirconoxane bonds (-Zr-O)- as mentioned above are randomly bonded, and has a chain, cyclic, ladder, cage, or network shape. It can take various structures. In the method of the present invention, the above-mentioned polycarbosilane and polyzirconosiloxane are combined by combining the total number of (-Si-CH ₂ )- structural units of the polycarbosilane with the (-Zr-O)- bond of the polyzirconosiloxane. Unit and (-Si-
O) - The ratio of the total number of bonding units is 100:1 to 1:100
and the resulting mixture is reacted, thereby forming a crosslink between the two polymers. As explained earlier, the crosslinking reaction mainly involves the elimination of hydrogen atoms bonded as side chain groups among the silicon atoms of the structural unit (-Si-CH ₂ )- in the main chain skeleton of polycarbosilane. A reaction in which the separated silicon atoms are bonded via oxygen to a portion of the silicon atoms and/or zirconium atoms of the siloxane bond units and/or zirconoxane bond units in the main chain skeleton of polyzirconosiloxane,
The organometallic copolymer of the present invention, which is a crosslinked block copolymer, is thus produced. Therefore, when focusing on the polycarbosilane moiety of the block copolymer, the silicon atoms in the main chain skeleton involved in crosslinking had two side chain groups before the crosslinking reaction, but After the reaction, it has one side chain group,
The silicon atoms in the main chain skeleton that are not involved in crosslinking substantially have two side chain groups selected from hydrogen atoms, lower alkyl groups, and phenyl groups. The organometallic copolymer of the present invention produced by the method described above is a block copolymer with a molecular weight of 1,000 to 50,000, in which the polycarbosilane and polyzirconosiloxane specified in the present invention are crosslinked. It is a thermoplastic substance that melts when heated at 50 to 400°C, and is soluble in solvents such as benzene, toluene, xylene, and tetrahydrofuran. FIG. 7 shows the infrared absorption spectrum (IR) of the organometallic copolymer of the present invention obtained by the method of Example 1. It is a block copolymer consisting of a polycarbosilane partially containing siloxane bonds obtained from silane and polyborodiphenylsiloxane, and polyzirconosiloxane obtained from diphenylsilanediol and zirconium tetrabutoxide. Taking into consideration the IR of the starting materials (polycarbosilane and polyzirconosiloxane) shown in Figures 5 and 6, the assignment of the IR of the block copolymer shown in Figure 7 is determined as follows. It is. Si- _C6H5 around 500cm ^-1 , 700cm ^-1 ; Si- _CH3 around 800cm ^-1 , 1250cm ^-1 _; Si-O-Zr around 950cm ^-1 ;
Si−CH ₂ −Si of 1020 to 1030 cm ⁻¹ ; 1050 cm ⁻¹ , 1120
cm ^-1 Si-O; 1430 cm ^-1 Si-C ₆ H ₅ ; 2100 cm ^-1
Si-H; C in Zr-OC ₄ H ₉ from 2850 to 2940 cm ^-1
-H; C-H at 2900 cm ^-1 and 2950 cm ^-1 ; Absorption corresponding to each C-H bond at C ₆ H ₅ near 3050 cm ^-1 is shown in IR in FIG. As explained above, the organometallic copolymer of the present invention is a crosslinked block polymer with a novel structure;
This copolymer is mainly composed of ZrC and SiC, and when fired in an inert gas atmosphere or a non-oxidizing gas atmosphere, it has superior mechanical strength compared to conventional SiC. It can be converted into a composite carbide in which SiC is partially dissolved. In addition, since it melts when heated and is soluble in organic solvents, it can be molded into various shapes. By heating and firing, it is possible to obtain a composite carbide compact having the above-mentioned structure and having extremely excellent performance. Examples of such molded bodies include continuous fibers, films, coatings, powders, etc. mainly made of this composite carbide. Furthermore, the organometallic copolymer of the present invention can be used as a sintering binder or an impregnating agent in addition to the composite carbide products mentioned above, and has excellent heat resistance, so it can be used in a variety of applications even as a polymer. It is expected that the 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 and refluxed 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, 759 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 quartz tube equipped with a reflux tube for 6 hours to polymerize. A polycarbosilane to be used as a raw material for the copolymer of the present invention was obtained. After cooling at room temperature, xylene was added to take out the solution, xylene was evaporated, and the mixture was concentrated at 330° C. for 2 hours under a nitrogen stream to obtain 130 g of solid. The number average molecular weight of this polymer was 1500 as measured by vapor pressure osmosis method (VPO method).
When we measured the IR spectrum of this substance, the fifth
^As shown in the figure, ^Si-
Absorption of CH ₃ , absorption of C-H at 1400, 2900, 2950 cm ^-1 , absorption of Si-H at 2100 cm ^-1 , absorption of Si-H at 1020, 1355 cm ^-1
Absorption of Si-CH ₂ -Si, absorption of Si-O near 1100 cm ^-1 , absorption of Si-C ₆ H ₅ at 700, 1120, and 1430 cm ^-1 were observed, and the resulting polymer showed that the constituent elements were

【formula】 【formula】

【formula】

【formula】

It is a polycarbosilane with the formula: Reference Example 2 864 g of diphenylsilanediol and 383 g of zirconium tetrabutoxide were weighed out, xylene was added thereto, and a reflux reaction was carried out at 150° C. for 1 hour under nitrogen gas. After the reaction was completed, insoluble materials were filtered off, and the solvent xylene was removed using an evaporator, and the resulting intermediate product was further heated at 300°C under nitrogen gas for 1
Polyzirconosiloxane used as a raw material for the copolymer of the present invention was polymerized by heating for a period of time to obtain a polymer in which the ratio of the total number of zirconoxane bonds to the total number of siloxane bonds was 1:4. The number average molecular weight is
It was 1650 according to the VPO method. When we measured the infrared absorption spectrum of this material, as shown in Figure 6, there was a slight Si-OH absorption near ~3600 cm ^-1 .
Absorption of benzene nuclei near 3050 cm ^-1 , absorption of C ₄ H ₉ near 2900 cm ^-1 , absorption of benzene nuclei between 1600 and 1350 cm ^-1 , absorption of Si-O between 1150 and 1000 cm ^-1 , and 950 cm ^-1
Absorption of Zr-O in the Zr-O-Si bond was observed in the vicinity, and the resulting polymer had a backbone of Zr, Si, and O, with a phenyl group in the side chain of Si and a butoxy group in the side chain of Zr. It is a polymer with Example 1 40g of polycarbosilane obtained in Reference Example 1,
40g of polyzirconosiloxane obtained in Reference Example 2
400 ml of xylene was added to this mixture to obtain a mixed solution consisting of a homogeneous phase, and a reflux reaction was carried out under a nitrogen gas atmosphere at 130° C. with stirring for 3 hours. After the reflux reaction was completed, the temperature was further raised to 200°C to distill out the xylene solvent, and then
Polymerization was carried out at 200°C for 2 hours to obtain an organometallic copolymer. The number average molecular weight of this polymer is VPO
According to the law, it was 3600. The results of the gel permeation chromatography of this material shown in FIG. As is clear from the comparison of the results of the Shion chromatography, the polymer obtained here is not simply a mixture of the above-mentioned polycarbosilane and polyzirconosiloxane, but has a high molecular weight due to the reaction of both raw material polymers. It is a copolymer made of Furthermore, as is clear from the comparison between the IR spectrum of this substance shown in Figure 7 and the IR spectra of polycarbosilane and polyzirconosiloxane shown in Figures 5 and 6,
The polymer obtained here consists of a polycarbosilane part and a polyzirconosiloxane part, and some of the Si-H bonds in the polycarbosilane part disappear, and this part becomes the silicon of the polyzirconosiloxane part. It is a copolymer in which a polycarbosilane portion and a polyzirconosiloxane portion are crosslinked by bonding to at least a portion of atoms and/or zirconium atoms via an oxygen atom. The total number of (-Si-CH ₂ )- bonds in the polycarbosilane moiety versus the (-Zr-O)- bonds and (-Si-
The ratio of the total number of O)-bonds is 7:2. The copolymer obtained here was heated in a nitrogen atmosphere.
The mixture was heated to 1700°C for 8.5 hours and calcined at 1700°C for 1 hour to obtain a black solid. When X-ray powder diffraction measurements were performed on this substance, as shown in Figure 8,
(111) diffraction line of β-SiC at 2θ=35.8°, 2θ=
(220) diffraction line of β-SiC at 60.1° and 2θ = 72.1
The (311) diffraction line of β-SiC is at 2θ = 33.7
(111) diffraction line of ZrC at 2θ=39.1°
(200) diffraction line of ZrC, 2θ = 56.3° (220)
A (311) diffraction line of ZrC was observed at 2θ=67.0°. In particular, each diffraction line of ZrC is shifted to a higher angle than the 2θ of each diffraction line observed in conventional ZrC, and since the lattice constant is different from that of conventional ZrC, the obtained material mainly β
-Contains SiC and ZrC, and β-SiC and ZrC
It is estimated that it is a composite carbide with some solid solution. Example 2 600 g of diphenylsilanediol and 675 g of tetrakis acetylacetonatozirconium were weighed out, xylene and ethanol [xylene/ethanol = 4/1 (volume ratio)] were added, and the solvent was removed.
Reference example 2 except for reacting at 250°C for 30 minutes
The number average molecular weight used as a raw material for the copolymer of the present invention is 950, and the ratio of the total number of di-1conoxane bonds to the total number of siloxane bonds is 1:
Polyzirconosiloxane No. 2 was obtained. Weigh out 95 g of this polymer and 40 g of the polycarbosilane obtained in Reference Example 1, add 500 ml of xylene to this mixture to make a mixed solution consisting of a homogeneous phase, and reflux with stirring at 130°C for 2 hours under a nitrogen gas atmosphere. The reaction was carried out. After the reflux reaction was completed, the temperature was further raised to 200°C to distill off the solvent xylene.
Polymerization was carried out at 200°C for 2 hours to obtain an organometallic copolymer with a number average molecular weight of 5670. The total number of (-Si-CH ₂ )- bonds in the polycarbosilane portion of this polymer versus the (-Zr-O)- bonds and (-Si
The ratio of the total number of -O)- bonds is about 7:4. Example 3 72g of polycarbosilane synthesized in Reference Example 1,
8g of polyzirconosiloxane synthesized in Reference Example 2
400 ml of benzene was added to this mixture to make a mixed solution consisting of a homogeneous phase, and the mixture was heated for 70 mL under a nitrogen atmosphere.
The reflux reaction was carried out with stirring at °C for 5 hours. After the reflux reaction was completed, the benzene was distilled off by further heating and polymerization was carried out at 250°C for 1 hour, resulting in a number average molecular weight of 8160.
An organometallic copolymer was obtained. The obtained polymer was a uniform transparent resinous material. The ratio of the total number of (-Si-CH ₂ )- bonds in the polycarbosilane part of this resin-like material to the total number of (-Zr-O)- bonds and (-Si-O)- bonds in the polyzirconosiloxane part is The ratio is approximately 31:1.

[Brief explanation of the drawing]

Figure 1 shows gel permeation chromatography (GPC) of the polycarbosilane of Reference Example 1, and Figure 2 shows the gel permeation chromatography (GPC) of the polycarbosilane of Reference Example 2.
GPC, Figure 3 shows the GPC of the organometallic copolymer of the present invention in Example 1, and Figure 4 shows the GPC of the polycarbosilane of Reference Example 1 and the polyzirconosiloxane of Reference Example 2 in a weight ratio of 1:1. It is GPC. Figure 5 shows the infrared absorption spectrum (IR) of the polycarbosilane of Reference Example 1, Figure 6 shows the IR of the polyzirconosiloxane of Reference Example 2, and Figure 7 shows the organometallic copolymer of the present invention in Example 1. This is a combined IR. FIG. 8 is an X-ray powder diffraction diagram of a composite carbide obtained by firing the organometallic copolymer of the present invention of Example 1 at 1700° C. in a nitrogen atmosphere.

Claims (1)

[Claims] 1 Organometallic crosslinking with a number average molecular weight of about 1000 to 50,000, consisting of a polycarbosilane part (A) with a number average molecular weight of about 500 to 10,000 and a polyzirconosiloxane part (B) with a number average molecular weight of about 500 to 10,000 It is a block copolymer; the polycarbosilane moiety (A) has a main chain skeleton mainly consisting of structural units of the formula (-Si-CH ₂ )-, where the silicon atom is a hydrogen atom, a lower alkyl and phenyl group; the polyzirconosiloxane moiety (B) has a zirconoxane bonding unit (-
It has a main chain skeleton in which Zr-O)- and siloxane bond units (-Si-O)- are randomly bonded, and the ratio of the total number of zirconoxane bond units to the total number of siloxane bond units is 30:1 to 1. :30, most of the silicon atoms of the siloxane bonding unit have one or two side chain groups selected from the group consisting of a lower alkyl group and a phenyl group, and the zirconoxane bonding unit has a Most of the zirconium atoms have one or two lower alkoxy groups, phenoxy groups or acetylacetoxy groups as side chain groups; at least a part of the silicon atoms of the polycarbosilane moiety (A) At least a portion of the silicon atoms and/or zirconium atoms of the polyzirconosiloxane moiety (B) are bonded via oxygen atoms, thereby forming a bond between the polycarbosilane moiety (A) and the polyzirconosiloxane moiety (B). and the total number of (-Si-CH ₂ )- structural units of the polycarbosilane moiety (A) versus (Zr-O)- of the polyzirconosiloxane moiety.
The ratio of the total number of bond units and (-Si-O)- bond units is
100:1 to 1:100; melts when heated at 50 to 400°C, and is soluble in organic solvents;