JPH0670138B2 - Silicon-containing polycyclic aromatic polymer and method for producing the same - 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 precursor polymer which becomes an inorganic fiber and a method for producing the same.

(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.

Carbon fiber is made from polyacrylonitrile
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 Publication No. 16 discloses a method of effectively generating mesophases and orienting them 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 carbon fiber surface treatment methods have been devised, and as a currently known method, polyvinyl alcohol, unsaturated polyester resin, and epoxy resin are used for the purpose of imparting flexibility to the fiber and suppressing fuzz formation. There are a method of applying such a sizing agent to the surface, a method of subjecting the surface to a dry or wet oxidation treatment for the purpose of improving the adhesiveness with the matrix, and the like.

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, coal- or petroleum-based pitch and polysilane are mixed and heated to synthesize an organopolyarylsilane, which is spun, infusibilized, and fired to have an intermediate property between silicon carbide fiber and carbon fiber. However, it is said that the organopolyarylsilane obtained by the above method contains no organic solvent insoluble matter and is the most important component for strength development of carbon fiber. Does not include mesophase state.

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 precursor polymer of carbon-based inorganic fibers.

According to the present invention, (A) a group mainly composed of a bonding unit (Si—CH ₂ ) and a bonding unit (Si—Si), and a group consisting of a hydrogen atom, a lower alkyl group, a phenyl group and a silyl group in the side chain of a silicon atom. has a side chain selected from the ratio of the total number of bond units (Si-Si) for the total number of bond units (Si-CH ₂₎ 1: organosilicon polymer units in the range of 0 to 20, (B) From a polycyclic aromatic compound unit whose skeleton component is mainly a condensed ring structure and is in a mesophase state, and (C) A polycyclic aromatic compound unit whose skeleton component is mainly a condensed ring structure and which is an optically isotropic phase Where at least a part of the silicon atom in the above (A) is
And / or (C) is bonded to a carbon atom of the aromatic ring, and the weight ratio of (A) to the sum of (B) and (C) is 1: 0.1 to 200, and Average molecular weight is 200
There is provided a silicon-containing polycyclic aromatic polymer characterized by being ˜10000.

Further, according to the present invention, i) a group mainly composed of a bonding unit (Si—CH ₂ ) and a bonding unit (Si—Si), and a group consisting of a hydrogen atom, a lower alkyl group, a phenyl group and a silyl group in a side chain of a silicon atom. Having a side chain selected from the total number of bond units (Si—CH ₂ ) vs. bond units (S
At least a part of the silicon element of the organosilicon polymer having a ratio of the total number of i-Si) in the range of 1: 0 to 20 is a petroleum-based or coal-based pitch or a heat-treated product thereof, and Random copolymer 100 bonded to carbon of aromatic ring of polycyclic aromatic compound obtained from pitch containing no insoluble matter
Parts by weight, and ii) a polycyclic aromatic compound obtained by heat-treating a petroleum-based or coal-based pitch or composed of both phases of a mesophase and an optically isotropic phase (hereinafter, both are collectively referred to as a mesophase polycyclic aromatic compound). It may be called a compound.) 2-3900
Provided is a method for producing a silicon-containing polycyclic aromatic polymer, which comprises subjecting parts by weight to heating reaction and / or heating and melting at a temperature in the range of 200 to 500 ° C.

The manufacturing method of the present invention will be described first. In the following description, all "parts" are "parts by weight", and all percentages (%) as units of component content are% by weight.

Random copolymer i) which is one binding unit of a raw material for synthesizing (Si-Si) and consisting of binding units (Si-CH ₂₎ organosilicon polymer can be synthesized by a known method, for example, dimethyl It is obtained by heating polydimethylsilane obtained by the reaction of dichlorosilane and metallic sodium to 400 ° C. or higher in an inert gas. The weight average molecular weight (Mw) of this organosilicon polymer is generally 300 to 1000, and M
Those in which w is 400 to 800 are particularly preferable for preparing the random copolymer i) which is an intermediate raw material for obtaining an excellent carbon-based inorganic fiber.

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,
Coal pitches such as pitch obtained from naphthatar and coal tar pitch, which are soluble in organic solvents such as benzene, toluene, xylene and tetrahydrofuran. The weight average molecular weight (Mw) of the organic solvent-soluble pitch is generally 200 to 800, and Mw of 250 to 600 is a random co-polymer which is an intermediate raw material for obtaining excellent carbon-based inorganic fibers. Especially preferred for preparing coalesced i).

As a raw material, the advantage of using the solvent-soluble component is that, in a wide range of use ratios of the organosilicon polymer and the pitch, a low-melting point and solvent-soluble random copolymer is obtained,
The solvent-insoluble impurities in the random copolymer can be purified by filtration, and the heating reaction and / or melting of the random copolymer i) and the mesophase polycyclic aromatic compound ii) can be performed in a wider range. It can be performed under a moderate condition and in a homogeneous manner. Therefore, when spinning the obtained silicon-containing polycyclic aromatic polymer, spinning at a lower temperature is possible.

The random copolymer i) is prepared by adding a solvent-soluble component of petroleum-based or coal-based pitch to an organosilicon polymer and heating and reacting it in an inert gas, preferably at a temperature of 250 to 500 ° C. It

The ratio of the pitch used is 2 to 1 per 100 parts of the organosilicon polymer.
It is preferably 900 parts. If the proportion of the pitch component used is too small, the amount of the organosilicon polymer component increases,
The compatibility with pitch containing mesophase deteriorates, and when the inorganic fiber is prepared from the polymer of the present invention, the homogeneity in the spinning dope is impaired, the strength of the baked yarn and the elastic modulus decrease, and the ratio is If the amount is too large, the amount of the organosilicon polymer component is too small, and the wettability of the baked yarn with respect to the matrix and the oxidation resistance are deteriorated.

If the reaction temperature of the above reaction is excessively low, the bond between the silicon atom of the organosilicon polymer and the aromatic carbon of the polycyclic aromatic compound becomes difficult to form, and if the reaction temperature is excessively high, the random copolymer formed The decomposition and high molecular weight of i) occur severely, which is not preferable.

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

The weight average molecular weight (Mw) of the random copolymer i) is generally 200 to 10,000, and the one having Mw of 250 to 8000 is a precursor polymer (silicon-containing polycyclic aromatic compound) for obtaining excellent inorganic fibers. It is particularly preferable as a raw material of (polymer).

The mesophase polycyclic aromatic compound ii) is prepared, for example, by heating petroleum-based or coal-based pitch in an inert gas at a temperature of 300 to 500 ° C. to perform polycondensation while removing the produced soft fraction. can do.

The mesophase polycyclic aromatic compound ii) has a melting point of 200-4.
It is in the range of 00 ° C and has a weight average molecular weight of 200 to 10,000
Is. However, since the mesophase polycyclic aromatic compound ii) contains an organic solvent insoluble matter, this weight average molecular weight should be hydrogenated under mild conditions to change this organic solvent insoluble matter to an organic solvent soluble ingredient. It is the value obtained by the subsequent GPC measurement (the weight average molecular weight of the polymer containing the organic solvent insoluble matter is the value obtained by performing the same treatment as above).

Among the mesophase polycyclic aromatic compounds ii), 20 to 10
An inorganic fiber having an optical anisotropy of 0% and containing 2 to 60% quinoline insoluble matter and 30 to 100% insoluble matter in benzene, toluene, xylene or tetrahydrofuran is excellent in mechanical performance. Is particularly preferred for obtaining a polymer for use.

The random copolymer i) and the mesophase polycyclic aromatic compound ii) are heated and / or heated and melted at 200 to 500 ° C.,
The silicon-containing polycyclic aromatic polymer of the present invention is obtained. that time,
It is also possible to carry out the mixing with the mesophase polycyclic aromatic compound ii) more homogeneously by using a solution of the random copolymer i) in an organic solvent.

The use ratio of the mesophase polycyclic aromatic compound ii) is preferably 2 to 4000 parts per 100 parts of the random copolymer i), and if less than 2 parts, the mesophase content in the product is insufficient, so the above-mentioned generation If a highly elastic fired yarn cannot be obtained from the product, and if it exceeds 4000 parts, the wettability of the inorganic fiber obtained from the product with respect to the matrix and the oxidation resistance are deteriorated due to the lack of the silicon component.

When the melt-mixing temperature is lower than 200 ° C, an infusible portion is generated,
The system becomes non-uniform, which adversely affects the strength and elastic modulus of the fired yarn, and when the melt-mixing temperature is higher than 500 ° C, the condensation reaction proceeds violently, the resulting polymer has a high melting point, and the spinning of the polymer is remarkable. It will be difficult.

Next, the silicon-containing polycyclic aromatic polymer obtained by the present invention will be described.

The silicon-containing polycyclic aromatic polymer obtained by the present invention is
Constituting the constituents (A), (B) and (C), at least a part of the silicon atoms of the constituent (A) is the constituent (B).
And / or is bonded to a carbon atom of the aromatic ring of component (C). The weight ratio of the component (A) to the sum of the component (B) and the component (C) is 1: 0.1 to 200, and the weight ratio of the component (B) to the component (C) is 1: 0.02 to. It is preferably 4. When the weight ratio of the component (A) to the sum of the component (B) and the component (C) is less than 0.1,
The mesophase component in the silicon-containing polycyclic aromatic polymer is insufficient, and the inorganic fiber obtained from this polymer has low strength and elastic modulus. Further, when the above ratio exceeds 200, the silicon-containing polycyclic aromatic polymer is Due to the lack of the organosilicon component in the cyclic aromatic polymer, the oxidation resistance of the inorganic fiber obtained from this polymer is lowered, and the wettability of the fiber with the FRP matrix is lowered.

Further, if the weight ratio of (C) to (B) is less than 0.02, spinning becomes extremely difficult during melt-spinning of the silicon-containing polycyclic aromatic polymer, such as reduced spinnability and yarn breakage due to uneven viscosity of the dope. 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 has a silicon atom of 0.
25-40% content, weight average molecular weight 200-10,000
And the melting point is 180 to 400 ° C.

The silicon atom content in the silicon-containing polycyclic aromatic polymer is 0.25.
If less than%, Si in the inorganic fiber obtained from the polymer,
Since the amount of the amorphous phase composed of C or O or the β-SiC ultrafine particles is too small, the wettability with respect to the FRP matrix and the oxidation resistance of the fiber are not significantly improved. High elasticity due to the orientation of the ultrafine graphite crystals in the fiber, heat resistance improvement in a non-oxidizing atmosphere cannot be achieved, and it is no different from SiC fiber.

If the weight average molecular weight of the silicon-containing polycyclic aromatic polymer is lower than 200, a highly elastic fired yarn cannot be obtained because it contains substantially no mesophase,
If it is larger than this, the melting point becomes high and spinning is difficult.

When the melting point of the silicon-containing polycyclic aromatic polymer is lower than 180 ° C., it does not substantially contain mesophase, and the precursor yarn obtained by spinning this polymer is easily fused at the time of infusibilization, strength, A fired yarn with a high elastic modulus cannot be obtained,
If the temperature is higher than 400 ° C, the polymer will be decomposed during spinning, and spinning will be difficult.

Further, 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 preferred.

The silicon-containing polycyclic aromatic polymer is
If it is less than 10% or the optical anisotropy degree is less than 5%, the orientation of the mesophase in the fiber axis direction hardly occurs during melt spinning, and thus the obtained precursor yarn has low strength even if it is infusibilized and fired. , Only low modulus fibers are obtained,
When the content of the organic solvent insoluble component is more than 98% or the optical anisotropy degree is more than 97%, the mesophase becomes excessive and spinning of the polymer becomes difficult.

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

(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 β-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 according to the present invention enables use of the carbon-based fiber in a high temperature oxidizing atmosphere, and an 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.

(Examples) 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 and then with water to obtain 420 g of white powdery polydimethylsilane.

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 in 1250 cm ^-1 of 0~900cm ^-1, Si in 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 to 400 ° C. under a nitrogen gas stream, and the distillate at the same temperature was distilled off to obtain 72 g of a residue.

The residue was dissolved in 500 ml of xylene, 4 g of insoluble matter was separated and removed, and then concentrated to obtain a 30% pitch xylene solution.

To 50 ml of a 30% solution of the above pitch, 50 ml of a 60% xylene solution of the organosilicon polymer obtained in Reference Example 1 was added, the temperature was raised with stirring, and xylene was distilled off and reacted at 400 ° C. for 6 hours to give 18 g of organic compound. A silicon polymer-polycyclic aromatic reaction product (random copolymer) 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 random 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 1810 and a melting point of 225 ° C.

(Second Step) 400 g of the FCC slurry oil obtained in Reference Example 2 was heated to 450 ° C. under a nitrogen gas stream, the distillate at the same temperature was distilled off, and the residue was hot filtered at 200 ° C. The infusible portion at the temperature was removed to obtain 180 g of the light component removal pitch.

180 g of the obtained light component removal pitch was subjected to polycondensation at 400 ° C. for 6 hours under a nitrogen stream while removing the light component produced by the reaction, to obtain a heat treated pitch of 90 g. This heat-treated pitch has a melting point of 260 ° C, xylene insoluble content of 88%, and quinoline insoluble content of 7%.
And the optical anisotropy of the polished surface observed by a polarizing microscope was 85% mesophase pitch.

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

This silicon-containing polycyclic aromatic polymer has a degree of optical anisotropy.
44%, xylene insoluble content 59%, melting point 240 ℃, hydrogenated under mild conditions, the weight average molecular weight (M _w ) was measured by gel permeation chromatography (GPC), M _w = 1380.

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 by using a high frequency plasma emission spectrophotometer (ICP). The silicon content of the silicon-containing polycyclic aromatic polymer was 1
It was 1.0%.

The above polymer was used as a spinning dope and melt-spun using a nozzle having a diameter of 0.3 mm. The obtained precursor yarn was made infusible at 300 ° C. under air flow, and fired at 1300 ° C. under an argon stream to obtain a carbon-based inorganic fiber. The thread diameter, tensile strength and tensile modulus of this fiber are 12μ, 160Kg / mm ² and 13t / mm ^{2 respectively.}
Met.

Examples 2 to 4 Preparation ratio and copolymerization conditions of the organosilicon polymer obtained by the method of the first step of Example 1 and the light component removal pitch, and Example 1
The silicon-containing polycyclic aromatic polymer was obtained by variously selecting the heat treatment conditions in the second step, the charging ratio in the third step of Example 1, and the melt mixing (melt condensation) conditions. The results are shown in Table 1 together with the results of Example 1. The silicon-containing polycyclic aromatic polymers obtained in each of the examples all show optical anisotropy and are dopes that can be spun at a relatively low melting point despite containing xylene-insoluble matter. It was

Comparative Example 1 100 g of the light content removal pitch obtained in Example 1 50 g of the organosilicon polymer obtained in Consideration 1 was added and reacted at 400 ° C. for 6 hours to obtain 79 g of an organosilicon polymer-polycyclic aromatic reaction product (random copolymer).

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

Comparative Example 2 The polymer obtained in Comparative Example 1 was spun, infusibilized and fired under the same conditions as in Example 1 to obtain a fired yarn. The thread diameter, tensile strength, and tensile elastic modulus of each fiber are 16μ and 75kg / m, respectively.
It was m ² and 5.0 t / mm ² .

Also, the fiber cross section did not contain any oriented structure.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Shibuya 5 1978, Ogushi, Ube, Yamaguchi Prefecture 5 1978, Ube Industries, Ltd. Ube Research Institute Examiner Yukio Hokura (56) References JP 62-209139 (JP, A) )

Claims (2)

[Claims] 1. A group consisting mainly of (A) a bonding unit (Si—CH ₂ ) and a bonding unit (Si—Si), and having a hydrogen atom, a lower alkyl group, a phenyl group and a silyl group in the side chain of a silicon atom. has a side chain selected, the ratio of the total number of bond units (Si-Si) for the total number of bond units (Si-CH ₂₎ 1: organosilicon polymer units in the range of 0 to 20, (B) backbone The component mainly comprises a condensed ring structure and is a polycyclic aromatic compound unit in a mesophase state, and (C) the skeleton component is mainly a condensed ring structure and is a polycyclic aromatic compound unit which is an optically isotropic phase. At least a part of the silicon atom of the above (A) is
And / or (C) is bonded to a carbon atom of the aromatic ring, and the weight ratio of (A) to the sum of (B) and (C) is 1: 0.1 to 200, and Average molecular weight is 200
A polycyclic aromatic polymer containing silicon, characterized in that 2. A bond unit (Si—CH ₂ ) and a bond unit (S)
i-Si) having a side chain selected from the group consisting of a hydrogen atom, a lower alkyl group, a phenyl group and a silyl group in the side chain of a silicon atom, and the total number of bond units (Si-CH ₂ ) pair bond At least a part of the silicon element of the organosilicon polymer having a ratio of the total number of units (Si-Si) within the range of 1: 0 to 20,
A petroleum-based or coal-based pitch or a heat-treated product thereof, wherein a random copolymer bonded to carbon of an aromatic ring of a polycyclic aromatic compound obtained from a pitch containing no insoluble matter in an organic solvent 100 wt. Part, and ii) 2 to 3900 parts by weight of a polycyclic aromatic compound having a mesophase state or both phases of a mesophase and an optically isotropic phase obtained by heat-treating a petroleum-based or coal-based pitch at 200 to 500 ° C. A method for producing a silicon-containing polycyclic aromatic polymer, which comprises heating and / or melting at a temperature within a range.