JPH0759627B2 - Method for producing silicon-containing polycyclic aromatic polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention provides a carbon-based material which has excellent mechanical properties due to infusibilization and firing, and has significantly improved oxidation resistance and wettability to a matrix for composite materials. The present invention relates to a method for producing a precursor polymer which becomes an inorganic fiber.

(Prior art and its problems) Since carbon fiber is lightweight, yet has high strength and high elasticity,
It is used in a wide range of fields such as sports / leisure goods, aircraft, bicycles, and building materials.

Polyacrylonitrile was used as the raw material for the carbon fiber.
So-called pitch-based carbon fibers made from PAN-based carbon fibers and petroleum-based or coal-based pitches are known.

Pitch-based carbon fibers are generally inferior in strength to PAN-based carbon fibers, but since the raw material is inexpensive, various studies have been made on a method for increasing the strength, for example, JP-A-59-2233.
Japanese Patent No. 16 discloses a method of effectively producing a female phase and orienting it during spinning.

However, since carbon fibers are basically crystalline fibers, they have the drawbacks that they are hard and easily fluffy, and that they are inferior in wettability with the matrix when they are used as a composite material.

Therefore, various surface treatment methods for carbon fibers have been proposed, and currently known methods include polyvinyl alcohol, unsaturated polyester resin, and epoxy resin for the purpose of imparting flexibility to the fiber and suppressing fuzz formation. There is a method of applying a different sizing agent to the surface, a method of oxidizing the surface by a dry method or a wet method for the purpose of improving the adhesiveness with the matrix.

Among these treatments, in particular, the method of providing the surface oxidation layer tends to deteriorate the physical properties because the fibers are damaged during the oxidation. Furthermore, carbon fibers cannot be used because they burn in an oxidizing atmosphere exceeding 500 ° C.

Against this background, we have developed a new fiber that has high strength, high elastic modulus, good wettability with the matrix, and good adhesion, and is cheaper than the PAN-based carbon fiber that has been used in a wide range of conventional fields. Has been strongly requested.

Further, it is strongly desired in various fields to improve the oxidation resistance of carbon fibers at higher temperatures.

As a method for satisfying this demand, for example, Japanese Patent Laid-Open No. 62-2091
The methods described in Japanese Patent Laid-Open No. 39 and Japanese Patent Laid-Open No. 62-215016 have been proposed.

In these publications, an organic solvent-soluble component in coal-based or petroleum-based pitch and polysilane are mixed and heated to synthesize an organopolyarylsilane, which is spun, infusibilized,
A method for producing an inorganic fiber having properties intermediate between silicon carbide fiber and carbon fiber by firing is described.

However, in the above method, a pitch containing no organic solvent insoluble matter is selected as one of the starting materials, and the reaction is carried out under the condition that the insoluble matter is not produced even in the production of organopolyarylsilane.

Therefore, the spinning raw material which is the obtained product does not contain the insoluble matter containing the mesophase state which is said to be the most important component for the strength development of the carbon fiber.

The inorganic fiber obtained by spinning, infusibilizing, and firing the above spinning raw material has a (002) diffraction line corresponding to graphite crystals of carbon depending on the conditions, but the orientation peculiar to the pitch fiber is not recognized and high elasticity is obtained. You can't get the rate. Further, in the method of the above-mentioned publication, as the pitch component increases, the heat resistance in the inert gas improves, but the oxidation resistance decreases conversely,
Moreover, there is a problem in that the mechanical properties are significantly reduced.

(Means for Solving Problems) An object of the present invention is to solve the above problems and to have the characteristic of high elasticity of pitch fibers, and to have excellent strength, oxidation resistance, and wettability to a composite material matrix. It is to provide a method for producing a precursor polymer of carbon-based inorganic fibers.

According to the production method of the present invention, (A) a bonding unit (Si—CH ₂ ) or a bonding unit (Si—C)
H ₂₎ primarily consists of coupling units (Si-Si), hydrogen atoms in the side chain of the silicon atom, a lower alkyl group, organosilicon polymer units having a side chain group selected from the group consisting of phenyl group and silyl group, (B) a polycyclic aromatic compound unit in which the skeleton component is mainly a condensed ring structure and is in a mesophase state, and (C) a polycyclic aromatic compound unit in which the skeleton component is mainly a condensed ring structure and is in an optically isotropic phase And at least a part of the silicon atom of (A) above is
A silicon-containing polycyclic aromatic polymer is obtained which is bonded to the carbon atom of the aromatic ring of (B) and / or (C).

That is, according to the present invention, i) bond unit (Si—CH ₂ ) or bond unit (Si—CH ₂ )
And a bond unit (Si-Si), having a side chain group selected from the group consisting of a hydrogen atom lower alkyl group, a phenyl group and a silyl group in the side chain of the silicon atom, and a bond unit (Si-
The ratio of the total number of CH ₂ ) to the total number of bonding units (Si-Si) is 1: 0 to 20
At least a part of the silicon atoms of the organosilicon polymer in the range of is a petroleum-based or coal-based pitch or a heat-treated product thereof, and is a polycyclic aromatic compound obtained from a pitch containing an insoluble matter in an organic solvent. 100 parts by weight of a random copolymer bonded to carbon of an aromatic ring, and ii) a polycyclic aromatic compound obtained by heat-treating a petroleum-based or coal-based pitch, or a mesophase and both phases of an optically isotropic phase Compound (hereinafter, both are collectively referred to as "mesophase polycyclic aromatic compound") 5 to 5000
There is provided a method for producing a silicon-containing polycyclic aromatic polymer, which comprises heating and reacting 0 part by weight at a temperature in the range of 200 to 500 ° C.

First, the silicon-containing polycyclic aromatic polymer obtained by the present invention will be described. In the following description, all "parts" are "parts by weight", and all percentages (%) as units of component content are% by weight.

The silicon-containing polycyclic aromatic polymer of the present invention comprises the constituent components (A), (B) and (C), and at least a part of the silicon atoms of the constituent component (A) is the constituent component (B) and / or Alternatively, it is bonded to a carbon atom of the aromatic ring of the constituent component (C). The weight ratio of the component (A) to the sum of the component (B) and the component (C) is 1: 0.5 to 5000, preferably
1: 1 to 500, and component (B) and component (C)
It is preferable that the weight ratio is 1: 0.02-4.

When the weight ratio of the constituent component (A) to the sum of the constituent component (B) and the constituent component (C) is less than 0.5, the mesophase component in the silicon-containing polycyclic aromatic polymer is insufficient and, for example, the inorganic substance is more inorganic than the polymer. Even if fibers are manufactured, only those with low strength and elastic modulus can be obtained, and if the above-mentioned surplus exceeds 5000,
Owing to the lack of the organosilicon component in the silicon-containing polycyclic aromatic polymer, the inorganic material of this polymer has a reduced oxidation resistance and a low wettability for plastics and the like.

When the weight ratio of (C) to (B) is less than 0.02, for example, when a silicon-containing polycyclic aromatic polymer is melt-spun, spinning is significantly reduced, such as a decrease in spinnability and breakage due to uneven viscosity of the dope. If the above ratio exceeds 4, it becomes difficult, and if the above ratio exceeds 4, the strength and elastic modulus of the inorganic fiber obtained from the polymer will be low due to lack of the mesophase component in the silicon-containing polycyclic aromatic polymer.

The silicon-containing polycyclic aromatic polymer of the present invention usually contains a silicon atom in an amount of 0.01 to 30%, preferably 0.05 to 30%,
Generally, the weight average molecular weight is 200 to 11,000 and the melting point is
200 to 400 ° C.

The silicon atom content in the silicon-containing polycyclic aromatic polymer is 0.01
When the amount is less than 1, the amount of the amorphous phase composed of Si, C, O or β-SiC ultrafine particles in the inorganic material of the polymer is too small,
For example, when the wettability to the FRP matrix and the oxidation resistance are not significantly improved, and when it exceeds 30%, it is highly elastic due to the orientation of the ultrafine graphite crystals in the above mineralized material, and the heat resistance in a non-oxidizing atmosphere. Improvement cannot be achieved.

When the weight average molecular weight of the silicon-containing polycyclic aromatic polymer is lower than 200, since it does not substantially contain mesophase, it is not possible to provide a high-performance inorganic fiber, composite material, or molded body, and when it is larger than 11000. Has a high melting point, is hard to soften and flow, and is difficult to be molded into an arbitrary shape.

When the melting point of the silicon-containing polycyclic aromatic polymer is lower than 200 ° C., the mesophase is not substantially contained, and when the polymer is spun to produce an inorganic fiber, the precursor yarn is fused at the time of infusibilization. It is difficult to obtain a fired yarn having high strength and elastic modulus. Further, when the melting point of the silicon-containing polycyclic aromatic polymer is higher than 400 ° C., the softening and the flow temperature become high and the polymer is decomposed, which is not preferable.

The silicon-containing polycyclic aromatic polymer contains 10 to 98% of an insoluble matter in an organic solvent such as benzene, toluene, xylene and tetrahydrofuran, and has an optical anisotropy degree of 5 to 97 at room temperature. % Is preferable.

When the content of the silicon-containing polycyclic aromatic polymer insoluble in the above organic solvent is less than 10% or the degree of optical anisotropy is less than 5%, especially when the polymer is melt-spun into a fiber, the fiber axial direction of the mesophase is Almost no orientation occurs, and therefore even if the obtained precursor yarn is infusibilized and fired, only fibers having low strength and low elastic modulus can be obtained. In addition, the organic solvent insoluble content is 98%
If it is contained in a larger amount or the optical anisotropy is larger than 97%, the mesophase in the polymer becomes excessive, and it takes a high temperature to soften and fluidize the polymer, making it difficult to mold it into an arbitrary shape. Become.

Since the silicon-containing polycyclic aromatic polymer of the present invention melts by heating, it can be used as a precursor of inorganic fibers.

Next, a method for producing the silicon-containing polycyclic aromatic polymer of the present invention will be described.

Organosilicon polymer consisting to be one of the starting material binding units (Si-CH _2), or binding units (Si-CH ₂₎ and the coupling unit (Si-Si) may be synthesized by a known method Polydimethylsilane obtained by reacting dimethyldichlorosilane with metallic sodium can be prepared, for example, in an inert gas at 40
Obtained by heating to 0 ° C or higher.

Another starting material, the polycyclic aromatic compound, is a pitch obtained by removing a light fraction from a fluid catalytic cracking residual oil of petroleum (FCC slurry oil) or its heat-treated oil,
Pitch obtained from naphthatar, coal-based pitch such as coal tar pitch, and among these, those having high aromaticity are suitable.

The pitch contains 5 to 98% of insoluble components in organic solvents such as benzene, toluene, xylene, and tetrahydrofuran.
%, Particularly preferably 10 to 80%. In particular,
For the purpose of producing inorganic fibers, when the above-mentioned pitch having an organic solvent insoluble content of less than 5% is used as a raw material, inorganic fibers excellent in both strength and elastic modulus cannot be obtained. Further, when the above-mentioned pitch in which the organic solvent insoluble content is more than 98% is used as a raw material, the obtained copolymer has a high melting point, which makes spinning difficult.

Random copolymer (1) is preferably obtained by adding petroleum-based or coal-based pitch to an organosilicon polymer, and preferably in an inert gas.
It is prepared by reacting by heating at a temperature of 250 to 500 ° C.

The ratio of the pitch used is 50 to 4 per 100 parts of the organosilicon polymer.
It is preferably 900 parts. If the proportion of the pitch component used is excessively small, the amount of the organosilicon component increases, the compatibility with the mesophase polycyclic aromatic compound deteriorates, the uniformity during melting is impaired, and the high-strength / high-modulus inorganic fiber is used. And composite materials cannot be obtained. If the ratio is too high,
Since the amount of the organosilicon polymer component is too small, the compatibility with the matrix and the oxidation resistance of the inorganic material produced from the polymer of the present invention are deteriorated.

If the reaction temperature of the above reaction is excessively low, the bond between the silicon atom and the aromatic carbon becomes difficult to form, and if the reaction temperature is excessively high, the generated random copolymer (1) decomposes and becomes high in molecular weight. It does not happen.

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

The mesophase polycyclic aromatic compound (2) is, for example, petroleum-based or petroleum-based pitch in an inert gas at 300 to 500 ° C.
It can be prepared by polycondensation while heating to the above temperature and removing the produced soft fraction.

The mesophase polycyclic aromatic compound (2) generally has a melting point in the range of 200 to 400 ° C. and a weight average molecular weight of 20.
0 to 10000.

Among the mesophase polycyclic aromatic compounds (2), 20-
Having 100% optical anisotropy, 30-100% benzene,
Those containing an insoluble matter in toluene, xylene or tetrahydrofuran are particularly preferable for obtaining a polymer which is an excellent raw material for inorganic fibers.

The random copolymer (1) and the mesophase polycyclic aromatic compound (2) are heated and / or melted at 200 to 500 ° C to obtain a silicon-containing polycyclic aromatic polymer.

The proportion of the mesophase polycyclic aromatic compound (2) used is preferably 5 to 50,000 parts per 100 parts of the random copolymer (1), and if less than 5 parts, the mesophase content in the produced polymer will be insufficient. , Even if the obtained polymer is mineralized, a highly elastic fiber or molded article cannot be obtained, and if it is more than 50,000 parts, wettability to the matrix even if the polymer is mineralized due to lack of silicon component, Properties such as oxidation resistance cannot be fully exerted.

When the melt-mixing temperature is lower than 200 ° C, an infusible portion is generated,
If the system becomes heterogeneous and the melt-mixing temperature is higher than 500 ° C., the condensation reaction will proceed violently and the resulting polymer will have a high melting point, resulting in loss of fluidity of the polymer.

(Effect) Since the silicon-containing polycyclic aromatic polymer according to the present invention contains an organosilicon copolymer and a mesophase polycyclic aromatic compound in the polymer, it is necessary to melt-spin, infusibilize, and calcine this polymer. Enables S on the graphite crystal of ultrafine particles.
It is possible to obtain a carbon-based inorganic fiber having a structure in which amorphous and / or B-SiC ultrafine particles composed of i, C, and O are dispersed, which has high strength and high elasticity and which is excellent in wettability with plastics. . As described above, there has been no fiber that can satisfy both mechanical properties and wettability with plastics at the same time, so that development of applications for FRP is particularly expected. Further, the fiber obtained from the polymer of the present invention enables the use of the carbon-based fiber in a high temperature oxidizing atmosphere, and at the same time, the oxidation-resistant carbon-based material can be obtained by molding the polymer of the present invention. . Further, the present invention has a great advantage in terms of effective use of pitch.

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

Reference Example 1 Anhydrous xylene 2.5 and 400 g of sodium were placed in the three-necked flask of Example 5, heated to the boiling point of xylene under a nitrogen gas stream, and dimethyldichlorosilane 1 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 then water,
420 g of white powdery polydimethylsilane was obtained.

400 g of this polydimethylsilane, a gas introduction tube, a stirrer,
A three-necked flask equipped with a condenser and a distilling tube was charged into a three-necked flask, and heat-treated at 420 ° C under a nitrogen stream of 50 ml / min with stirring, and 350 g of a colorless transparent slightly viscous liquid was put in a distilling receiver. Got

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 the 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.

Reference Example 2 Among petroleum fractions, high boiling point substances such as light oil and above are subjected to fluid catalytic cracking at a temperature of 500 ° C in the presence of a silica / alumina cracking catalyst.
Fractionation was performed to obtain a residue from the bottom of the column. Below this residue
Called 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.

Example 1 (First Step) 100 g of the FCC slurry oil obtained in Reference Example 2 was heated at 420 ° C. for 2 hours under a nitrogen gas stream of 1 / min, and the residue was distilled off at 150 ° C. after distilling off the distillate at the same temperature. At hot temperature, the infusible portion was removed at the same temperature to obtain 57 g of a light component removal pitch.

The light content removal pitch contained 60% xylene insoluble matter.

25 g of the organosilicon polymer obtained in Reference Example 1 and 20 ml of xylene were added to 57 g of this light component removal pitch, the temperature was raised with stirring, and xylene was distilled off and reacted at 400 ° C. for 6 hours to give 43 g of organosilicon polymer-- A polycyclic aromatic reaction product (random copolymer (1)) was obtained.

As a result of infrared absorption spectrum measurement, this reaction product showed a decrease in Si—H bond (IR: 2100 cm ⁻¹ ) existing in the organosilicon polymer and a new Si—C (carbon of benzene ring) bond (IR: 113).
By confirming the formation of 5 cm ⁻¹ ), it was found that the organosilicon polymer was a copolymer having a part of silicon atoms directly bonded to the polycyclic aromatic ring.

In addition, this copolymer did not contain a xylene-insoluble portion, had a weight average molecular weight of 1450 and a melting point of 265 ° C.

(Second step) 400 g of FCC slurry oil obtained in Reference Example 2 was heated at 450 ° C for 1 hour under a nitrogen stream of 1 / min, and the distillate at the same temperature was distilled off, and the residue was heated at 200 ° C. Filtration was performed to remove the infusible portion at the same temperature, and 180 g of a light material removal pitch was obtained.

180 g of the obtained light component removal pitch was subjected to polycondensation at 400 ° C. for 8 hours in a nitrogen stream while removing the light component produced by the reaction to obtain a heat treated pitch of 80.3 g. This heat treatment pitch has a melting point of 310 ° C, xylene insoluble content of 97%, quinoline insoluble content of 20%.
%, And was a mesophase polycyclic aromatic compound (2) having an optical anisotropy of 95% by a polarizing microscope observation of the polished surface.

(Third step) 40 g of the random copolymer obtained in the first step and 80 g of the mesophase polycyclic aromatic compound (2) obtained in the second step were melt mixed under a nitrogen atmosphere at 350 ° C. for 1 hour to obtain a uniform mixture. A silicon-containing polycyclic aromatic polymer in a state was obtained.

This silicon-containing polycyclic aromatic polymer has a degree of optical anisotropy.
51%, xylene insoluble content 68%, melting point 281 ℃, hydrogenated under mild conditions, the weight average molecular weight (M _W ) was measured by gel permeation chromatography (GPC), M _W = 1250.

This silicon-containing polycyclic aromatic polymer is heated in air to 1000 ° C., the obtained ash is subjected to alkali melting and hydrochloric acid treatment,
After dissolving in water, the silicon concentration of the aqueous solution was measured using a high-frequency plasma emission spectrophotometer (ICP). The silicon content in the silicon-containing polycyclic aromatic polymer was
It was 5.2%.

Examples 2 to 8 Charge ratio of the organosilicon polymer obtained by the method of the first step of Example 1 and the light removal pitch and copolymerization conditions, heat treatment conditions in the second step of Example 1, third of Example 1 Various charging ratios and melt-mixing (melt-condensation) conditions in the process were selected to obtain a silicon-containing polycyclic aromatic polymer. The results are shown in Table 1 together with the results of Example 1. The silicon-containing polycyclic aromatic polymer obtained in any of the examples has a silicon atom of 0.
It contained 4 to 24.8% and had optical anisotropy.

Example 9 (First step) FCC slurry oil 20 obtained in Reference Example 2 0 g was heated under a nitrogen gas flow of 2 / min for 450 hours for 0.5 hours, the distillate at the same temperature was distilled off, and the residue was filtered while hot at 200 ° C. to remove the infusible part at the same temperature to remove the light fraction. Removal pitch
Got 57g.

The light content removal pitch contained 25% xylene insoluble matter.

25 g of the organosilicon polymer obtained in Reference Example 1 and 20 ml of xylene were added to 57 g of this light component removal pitch, the temperature was raised with stirring, and xylene was distilled off and reacted at 400 ° C. for 6 hours to give 51 g of a random copolymer ( 1) was obtained.

As a result of infrared absorption spectrum measurement, this reaction product showed a decrease in Si—H bond (IR: 2100 cm ⁻¹ ) existing in the organosilicon polymer and a new Si—C (carbon of benzene ring) bond (IR: 113).
The formation of 5 cm ^-1 ) showed that the organosilicon polymer was a copolymer having a part of silicon atoms directly bonded to the polycyclic aromatic ring.

This random copolymer (1) does not contain a xylene-insoluble portion, has a weight average molecular weight of 1400, a melting point of 265 ° C., and a softening point of 310.
It was ℃.

(Second Step) On the other hand, 180 g of the light content removal pitch was subjected to polycondensation at 400 ° C. for 8 hours under a nitrogen stream while removing the light content produced by the reaction to obtain a heat treated pitch of 97.2 g. This heat-treated pitch contains a melting point of 263 ° C, a softening point of 308 ° C, xylene insoluble content of 77%, and quinoline insoluble content of 31%. It was a group compound (2).

(Third step) 6.4 g of the random copolymer (1) obtained in the first step and the second step
Mesophase polycyclic aromatic compound obtained in process (2)
90 g of the compound was melt-mixed at 380 ° C. for 1 hour in a nitrogen atmosphere to obtain a silicon-containing polycyclic aromatic polymer in a uniform state.

This silicon-containing polycyclic aromatic polymer has a degree of optical anisotropy.
The content was 61%, xylene insoluble content was 70%, melting point was 267 ° C, and softening point was 315 ° C.

Hydrogenation was carried out under mild conditions, and the weight average molecular weight (M _w ) was measured by gel permeation chromatography (GPC). The result was M _w = 900.

This silicon-containing polycyclic aromatic polymer is heated in air to 1000 ° C., the obtained ash is subjected to alkali melting and hydrochloric acid treatment,
Solubility in water and its aqueous solution were measured for silicon concentration using a high-frequency plasma emission spectroscopic analyzer (ICP). As a result, the silicon content in the silicon-containing polycyclic aromatic polymer was
It was 0.91%.

Examples 10 to 18 Preparation ratio and copolymerization conditions of organosilicon polymer and light removal pitch in the first step of Example 9, heat treatment conditions in the second step of Example 9, preparation ratio in the third step of Practical Example 9 Various melt-mixing (melt-condensation) conditions were selected to obtain a silicon-containing polycyclic aromatic polymer. The results are shown in Table 2 together with the results of Example 9. The silicon-containing polycyclic aromatic polymer obtained in any of the examples had optical anisotropy.

Comparative Example 1 (First Step) 200 g of the FCC slurry oil obtained in Reference Example 2 was heated at 420 ° C. for 2 hours under a nitrogen gas stream of 1 / min, and the light fraction was distilled off at the same temperature to remove the light fraction. 114 g of pitch was obtained. The obtained pitch was dissolved in 500 ml of xylene at 130 ° C. to remove 69 g of xylene-insoluble matter, and then 45 g of the xylene-soluble portion in the obtained pitch was added with 45 g of the organosilicon polymer obtained in Reference Example 1, The copolymers were combined at 400 ° C. for 6 hours to obtain 32 g of an organosilicon polymer-polycyclic aromatic reaction product (random copolymer).

(Second step) 200 g of the xylene-soluble pitch component obtained in the first step was heat-treated at 400 ° C. for 6 hours in an inert atmosphere to give a heat-treated pitch of 41 g.
Got

(Third Step) 30 g of the copolymer obtained in the first step and 60 g of the heat-treated pitch obtained in the step 2 were heated and mixed at 300 ° C. for 2.5 hours.

Weight average molecular weight (M _w ) of the product obtained by the above reaction
Was 1750 and the silicon content was 10.5%, but the melting point was 198 ° C.
The polymer was an optically isotropic polymer containing only 11% of xylene-insoluble matter.

Comparative Example 2 50 g of the organosilicon polymer obtained in Reference Example 1 was added to 100 g of the light component removal pitch obtained in Example 1, and the mixture was reacted at 400 ° C. for 6 hours to give 79 g of organosilicon polymer-polycyclic aromatic reaction product. (Random copolymer) was obtained.

The copolymer obtained has a melting point of 252 ° C and a silicon content of 15%.
Thus, the average weight molecular weight (M _w ) was 1400, the xylene-insoluble matter was not contained, and the mesophase portion was not present.

Example 19 The silicon-containing polycyclic aromatic polymer obtained in each of Examples 1 and 2 was used as a spinning dope, and melt-spun using a nozzle having a diameter of 0.3 mm. The obtained precursor yarn is 300 ° C under air circulation.
Was made infusible and was fired at 1300 ° C. under an argon stream to obtain a carbonaceous inorganic fiber. The fiber diameter, pull tension and tensile modulus of this fiber are 14 μm in the case of the dope of Example 1, respectively.
190 kg / mm ² , 18 t / mm ² , in the case of the dope of Example 2, 17
The values were μ, 161 kg / mm ² , and 15 t / mm ² .

By scanning electron microscope observation, all fibers have a cross-sectional structure similar to the radial structure used in pitch fibers, and the mesophase component in the dope is oriented in the fiber axis direction during spinning, infusibilization, and firing processes. It was showing that it did.

Example 20 The silicon-containing polycyclic aromatic polymer obtained in each of Example 9, Example 10 and Example 18 was used as a spinning dope, and melt-spun using a nozzle having a diameter of 0.15 mm. The obtained precursor yarn was made infusible at 300 ° C. under air flow and was fired at 1300 ° C. under an argon stream to obtain a carbonaceous inorganic fiber. The fiber diameter, tensile strength, and tensile elastic modulus of this fiber are 8 μ, 320 kg / mm ² , and 26 t / mm ² in the case of the dope of Example 9, and 9 μ, 260 kg / in the case of the dope of Example 10, respectively. mm ² , 24 t / mm ² , 8 in the case of Example 18
μ, 300 kg / mm ² , and 22 t / mm ² .

By scanning electron microscope observation, all fibers have a cross-sectional structure similar to the radial structure used in pitch fibers, and the mesophase component in the dope is oriented in the fiber axis direction during spinning, infusibilization, and firing processes. It was showing that it did.

Comparative Example 3 The polymers obtained in Comparative Examples 1 and 2 were spun, infusibilized and fired under the same conditions as in Example 20 to obtain a fired yarn. The yarn diameter, tensile strength, and tensile elastic modulus of each fiber are shown in Comparative Example 1 respectively.
In the case of the dope of No. 1, 17 μ, 105 kg / mm ² , 7.1 t / mm ² , and in the case of the dope of Comparative Example 2, 16 μ, 75 kg / mm ² , 5.0 t / mm ² .

Further, the fiber cross section did not include a portion having an oriented structure.

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

Claims (1)

[Claims] 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 or a lower alkyl group in the side chain of a silicon atom, Having a side chain group selected from the group consisting of a phenyl group and a silyl group, the total number of bond units (Si-CH ₂ ) vs. bond units (Si-Si)
At least a part of the silicon atoms of the organosilicon polymer having a ratio of the total number of 1 to 20 is a petroleum-based or coal-based pitch or a heat-treated product thereof, and a pitch containing an insoluble component in an organic solvent. 100 parts by weight of the random copolymer bonded to the carbon of the aromatic ring of the obtained polycyclic aromatic compound, and ii) a mesophase or a mesophase and an optically isotropic phase obtained by heat-treating a petroleum-based or coal-based pitch And polycyclic aromatic compound consisting of both phases of 5 to 50,000 parts by weight, 200 to 500
A method for producing a silicon-containing polycyclic aromatic polymer, which comprises heating and / or melting at a temperature in the range of ° C.