KR20150058009A - A method for isotropic pitch for manufacturing carbon fiber - Google Patents

Abstract

The present invention relates to an isotropic pitch manufacturing. method through a manufacturing method suitable for a primitive material with specific compound contents, ratios and properties, and a material which is generated from an intermediate procedure. The isotropic pitch manufacturing method of the present invention comprises the steps of: (a) manufacturing a material satisfying Formulas (1) to (4) by preprocessing a primitive material including at least one among a naphtha decomposition residue, a petroleum based heavy oil or coal tar distillate between 160 to 240 °C and (b) polymerizing and heating the material prepared in the step (a). The isotropic pitch manufactured according to the present invention, has excellent radiation and other properties, and thus a high strength and high elastic carbon fiber can be manufactured.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing an isotropic pitch for manufacturing carbon fibers,

The present invention relates to a method for producing an isotropic pitch, which comprises the steps of: preparing a raw material containing at least one of naphtha-decomposed residual oil, petroleum-derived crude oil or coal tar oil and a content of a specific compound contained in the raw material produced in the production step, The isotropic pitch produced by the manufacturing method satisfying the restrictive condition is excellent in physical properties and radioactivity Can be used to produce high-elasticity, high-strength carbon fibers.

Carbon fiber is lighter in weight than a relatively strong strength and can be used in a variety of fields such as sporting goods, aviation industry, and automobile. Therefore, much research has been conducted to obtain high strength and high elasticity carbon fiber. Mainly, high-strength and high-elasticity carbon fibers are mainly produced by oxidation stabilization and carbonization of PAN-based co-polymer fibers. Although high strength and high elasticity carbon fibers can be manufactured using anisotropic pitch, there is a problem that manufacturing cost is increased due to a complicated manufacturing process in order to produce carbon fibers having desired strength and elasticity level. Therefore, in recent years, studies on the production of high strength and high elasticity carbon fibers using isotropic pitches have been actively carried out.

Naphtha cracker bottom oil (NCB oil) has been attracting attention for the production of pitch carbon fibers. The naphtha cracker residue is a byproduct of naphtha cracking process. It is known that the content of insolubles is low and is suitable for manufacturing carbon materials. The naphtha-decomposed residual oil may be produced at an isotropic pitch or anisotropic pitch for producing pitch-based carbon fibers, depending on the conditions during the heat treatment. Among them, the isotropic pitch is amorphous, and the carbon fiber produced therefrom has a low strength, so anisotropic pitch is mainly used for producing high strength and high elasticity carbon fibers. In addition to naphtha cracking residues, petroleum heavy oils, oil fractions, and coal tar are also used in the manufacture of carbon materials.

The physical properties and composition of the isotropic pitch are important for producing high-strength and high-elasticity carbon fibers. In particular, high strength carbon fibers can be produced by using an isotropic pitch for producing carbon fibers having a certain range and level of molecular weight, softening point and viscosity. Japanese Unexamined Patent Publication (Kokai) No. 1996-144131 has invented an isotropic pitch for producing carbon fibers having a certain range of molecular weight. However, the carbon fibers produced from the carbon fibers have low tensile strength and can be used only as general purpose materials like conventional isotropic pitch carbon fibers. In addition, recently, a method of producing an isotropic pitch using a catalyst has been proposed, but the concrete properties of the carbon fiber produced therefrom are not known.

Most of the prior arts have focused on manufacturing methods such as the use of catalysts for producing isotropic pitches for carbon fibers, and it has been difficult to study the manufacturing methods from the analysis of raw materials.

In recognition of such a problem, the inventors of the present invention have conducted studies on a raw material analysis of an isotropic pitch for carbon fiber production and a manufacturing method corresponding thereto, and as a result, invented an isotropic pitch capable of producing high strength and high- It came.

Japanese Patent No. 3695077

The present invention provides a method for producing an isotropic pitch which can be used for producing high strength and high elastic carbon fibers with excellent physical properties and radioactive properties, and is characterized by using a raw material containing at least one of naphtha cracked residual oil, petroleum heavy oil or coal tar oil And an analysis of the raw material produced in the intermediate step and a suitable production method therefor.

The present invention relates to a process for producing an isotropic pitch, comprising a raw material comprising at least one of a naphtha cracking residue, a petroleum heavy oil or a coal tar oil fraction satisfying a specified range of physical properties, compound content and their ratio, Thereby providing a raw material to be produced and a suitable production method therefor.

In the present invention, the raw material can be obtained by pretreating a raw material containing at least one of naphtha-decomposed residual oil, petroleum heavy oil or coal tar oil.

In the present invention, the pretreatment may include a heating and a fractionation process.

The present invention provides a production method in which the raw material produced in the intermediate step of the isotropic pitch production method satisfies the atomic ratio, the degree of aromatization, the average molecular weight, the content of the contained compound, and the ratio thereof to a specific range.

The present invention provides a process for producing an isotropic pitch in which the raw material undergoes thermal polymerization and heating.

And provides an isotropic pitch produced according to the present invention.

The production method according to the present invention can produce carbon fibers having high strength and high elasticity to such an extent that they can produce isotropic pitches excellent in radioactivity with high physical properties and can be used for carbon composites using the produced isotropic pitches .

1 shows a process for producing a raw material having isotropic pitch and an isotropic pitch from NCB oil as a raw material.
Figure 2 shows representative compositions of raw materials and raw materials produced in the intermediate stages.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. The contents of the notice may not be separately described.

The present invention is a method for producing an isotropic pitch by thermally polymerizing and heating a raw material obtained by pretreating a raw material containing at least one of naphta cracking botto oil (NCBO), petroleum hydrocarbons or coal tar oil.

The present invention relates to a method for producing an isotropic pitch by thermally polymerizing and heating a raw material obtained by pretreating a raw material containing at least one of naphta cracking botto oil petroleum intermediate or coal tar oil.

The naphtha cracking residues may include pyrolyzed fuel oil (PFO), which is a type of naphtha cracking residue. PFO is produced at the naphtha cracking center (NCC) bottom of the naphtha cracking process and is highly oriented and rich in resin. PFO includes not only saturated compounds but also various aromatic hydrocarbons such as benzene, naphthalene, indene and biphenyl.

Petroleum hydrocarbons or coal tar oils as well as naphtha cracked residues also contain saturated compounds and various aromatic hydrocarbons, which can be used in the production of pitch and carbon fibers.

It is possible to control the physical properties and composition of the raw material for producing the isotropic pitch according to the pretreatment conditions of the raw material including at least one of naphtha-decomposed residual oil, petroleum-derived heavy crude oil and coal tar oil, and the physical properties and composition of the raw material are high strength, Lt; RTI ID = 0.0 > isotropic < / RTI > pitch for carbon fiber fabrication.

In the present invention,

(a) pretreating a raw material containing at least one of naphtha-decomposed residual oil, petroleum-derived heavy oil or coal tar oil to produce a raw material; And

(b) thermally polymerizing and heating the raw material prepared in (a) above;

And a method of manufacturing an isotropic pitch.

In the preparation process, the pretreatment can include a heating and a fractionation process, and it is possible to remove a low molecular substance which is less likely to form an oligomer by thermal polymerization reaction, and at the same time, The compound can be removed. For example, one of the main objectives is to convert a compound containing one benzene ring, such as alkenylbenzenes or indenes, which may cause negative side reactions in the isotropic pitch synthesis step, to a compound which is more stable and is effective for the production of isotropic pitch can see. The pretreatment can be carried out by heating and fractionating the raw material at a temperature of from 150 to 260 캜, preferably from 160 to 240 캜, more preferably from 175 to 235 캜 at atmospheric pressure until no further volatilization occurs.

The pretreatment can also proceed under pressure or reduced pressure. Under reduced pressure, the process can be carried out at a lower temperature. In the case of pressurization, a higher temperature is required. However, it is advantageous to supplement the design of the device to more precisely fractionate. The preprocessing process can freely adjust the pressure and the temperature within a range that achieves the same effect as the atmospheric pressure. Further, after the distillation, the filtration process may proceed under atmospheric pressure, pressurization or reduced pressure as necessary.

The filtration step removes the solid matter and the solid matter acts as a cracker in the structure of the carbon fiber produced from the isotropic pitch as a solid residue containing impurities such as metal, sulfur, nitrogen and the like, .

The filtration step can be carried out by a method commonly used in the art, for example, filtration, centrifugation, sedimentation, adsorption, extraction and the like.

The main properties of the raw material produced in the intermediate stage of the production process of the present invention are important. Of these main properties, carbon and hydrogen have an atomic ratio, degree of aromatization, average molecular weight, etc. Having a specific range of properties has a great influence on the production of isotropic pitch and further in the production of high strength high-elasticity carbon fibers.

The aromaticity fa of the raw material may be 0.70 to 0.95, preferably 0.75 to 0.90. If the degree of aromatization is low, the hydrocarbon yield may be lowered. There is no particular limitation on the case where the degree of aromatization is high, but if it is more than the above preferable range, the isotropic pitch disclosed in the present invention may not be easy to produce.

The average molecular weight (Mw) of the raw material may have a distribution of 150 to 300, preferably 185 to 290, more preferably 190 to 245. The range of the optimum molecular weight of the raw material affects the molecular weight of the produced isotropic pitch and the range of the specific molecular weight of the isotropic pitch has an important influence on the production of high strength and high elasticity carbon fibers. When the molecular weight is low, the molecular weight of the produced isotropic pitch is lowered, so that it may be difficult to produce carbon fibers of desired strength. When the molecular weight is high, the effect of thermopolymerization and heating which are precisely controlled for the production of high- have.

The raw material containing at least one of the naphtha-decomposed residual oil, petroleum-derived trehalose, or coal tar oil fraction of the present invention and the compound contained in the raw material produced at the intermediate stage may contain a saturated compound, A compound containing a ring, a compound containing two aromatic rings, a compound containing three aromatic rings, and a compound containing at least four aromatic rings. The compounds may include a condensed polycyclic compound structure or a compound containing a polycyclic compound structure such as biphenyl in which aromatic rings are linked singly or in multiple bonds. For example, such compounds may include benzene, indene, naphthalene, biphenyl, anthracene, and the like, but a wide variety of compounds and derivatives including aromatic rings may be present.

The types of raw materials including at least one of naphtha-decomposed residual oil, petroleum-based crude oil and coal tar oil and the compounds containing aromatic rings in raw materials produced in the intermediate stage vary widely. Among them, For the production of isotropic pitch, there is a main compound in which the content of the raw material and the compound contained in the raw material needs to be controlled.

Among the compounds containing one aromatic ring, it is particularly important to control the content of alkenylbenzene and indene, particularly, among the compounds containing two aromatic rings, the content of biphenyls and naphthalenes, The content of the compound having aromatic rings should be regulated as a whole to produce an isotropic pitch excellent in physical properties and radioactivity and ultimately to produce carbon fibers having high elasticity and high strength properties. This is because it does not participate in the reaction in the pitch synthesis step or it generates a mesophase partially in insoluble solid or synthesized pitch by overly reactive compounds. Such insoluble solid matter and mesophase portion become major factors that deteriorate physical properties of the pitch and radioactivity and mechanical properties of the carbon fiber, and it becomes impossible to obtain the isotropic pitch for producing the high strength carbon fiber desired in the present invention.

That is, the isotropic pitch for manufacturing the high strength and high-elastic carbon fibers can be manufactured by satisfying very limited conditions.

In the present invention, when the content of the raw material including at least one of naphtha-decomposed residual oil, petroleum-derived crude oil or coal tar oil and the content of the compound contained in the raw material produced in the intermediate stage and the content ratio thereof is within a specific range, It is possible to manufacture isotropic pitches for producing high strength and high elasticity carbon fibers by satisfying very limited conditions.

First, the content of the raw material produced in the intermediate stage for producing the desired isotropic pitch in the present invention will be described in detail.

The compound containing one aromatic ring is 20.0 to 45.0%, preferably 30.0 to 40.0%, more preferably 35.0 to 40.0% of the total amount of the raw materials. Among them, indenes are very strongly reactive substances, which are involved in various side reactions during long-term storage or synthesis of pitches at high temperatures, and are capable of producing molten solids or partially fried mesophases in the pitch polymerization step It is necessary to limit the content. The content of indenter is not more than 75.0%, preferably 35.0 to 75.0% based on the total amount of the compound including one aromatic ring, and is 5.0 to 30.0%, preferably 15.0 to 25.0%, based on the total amount of the raw materials, And a specific range of ratios. Alkenylbenzenes such as olefins also have very strong reactivities similar to those of indenes, and it is difficult to produce isotropic pitches of desired physical properties by providing protons and electrons to the surrounding compounds in the pitch polymerization step, resulting in a great variety of side reactions In the case of alkenylbenzenes, most of them can be removed by volatilization during the pretreatment.

The compound containing two aromatic rings is 50.0 to 70.0%, preferably 55.0 to 65.0%, more preferably 55.0 to 60.0% of the total amount of the raw materials. Among them, the content of the naphthalenes is 30.0% or more, preferably 35.0% or more, relative to the total amount of the compounds containing two aromatic rings, and 15.0 to 75.0%, preferably 20.0 to 60.0% Is 30.0 to 50.0%. The biphenyls do not contribute greatly to the polymerization reaction, and the lower the content, the better the content is 15.0% or less, preferably 10.0% or less, relative to the total amount of the compounds containing two aromatic rings, It is preferable to include or not contain a very small amount so as to be not more than 10.0%, preferably not more than 5.0%, more preferably not measurable, relative to the total amount of the raw materials.

A compound containing three aromatic rings and a compound containing four or more aromatic rings may not participate in the polymerization reaction or may be a condensed aromatic compound having an excessively large number of rings due to the influence of an olefin such as alkenylbenzene and a lead- To form a ring compound. Such condensed aromatic ring compounds can easily form a laminate structure and partially generate insoluble solids or mesophases at the synthesized pitch, so that it is also necessary to control the content of compounds containing three or more aromatic rings. It is preferable that the compound containing three aromatic rings is contained in an amount of not more than 10.0%, preferably not more than 5.0% of the total amount of the raw materials, and more preferably, such a small amount as not to be measurable. It is preferable that the compound containing four or more aromatic rings is contained in an amount of not more than 5.0%, preferably not more than 3.0% of the total amount of the raw materials, more preferably not to be measurable.

In order to produce the desired isotropic pitch in the present invention, the compounds contained in the raw materials as described above must satisfy the respective contents, and at the same time, they must satisfy the specific content ratios.

The content ratio of the compound contained in the raw material produced in the intermediate step of the present invention should satisfy the following.

The content ratio of the compound containing an aromatic ring is Ar_One/ Ar₂0.30 < Ar_One/ Ar₂&Lt; 0.75, preferably 0.40 < Ar_One/ Ar₂&Lt; 0.70, more preferably 0.65 < Ar_One/ Ar₂Lt; 0.70. Next, Ar_One/ Ar₃2.00 < Ar_One/ Ar₃&Lt; 12.00, preferably 4.00 < Ar_One/ Ar₃&Lt; 10.00, more preferably 8.00 < Ar_One/ Ar₃&Lt; 9.00. And Ar₃/ Ar₂And Ar₃/ Ar₂&Lt; 0.20, preferably Ar₃/ Ar₂&Lt; 0.15, more preferably Ar₃/ Ar₂<0.10 to be. In the above content ratio, Ar_OneIs the content of a compound containing one aromatic ring with respect to the total amount of raw materials, Ar₂Is the content of a compound containing two aromatic rings relative to the total amount of raw materials, Ar₃Represents the content of the compound containing three aromatic rings relative to the total amount of the raw materials. The compound containing four or more aromatic rings relative to the total amount of the raw materials is preferably Ar₄.

The content ratio of indene and naphthalene with respect to the total amount of raw materials is preferably 0.10 <tennary / naphthalene <2.00, preferably 0.15 <tennin / naphthalene <1.50, more preferably 0.50 <tennin / naphthalene <0.80 .

The lower the ratio of the biphenyls to the naphthalenes relative to the total amount of the raw materials, the better the biphenyls / naphthalenes <0.20, preferably the biphenyls / naphthalenes <0.15. When the content ratio of the biphenyls and naphthalenes in the raw material produced in the intermediate stage is 0.20 or more, the reason is not clear, but the radioactive and physical properties of the produced isotropic pitch are poor and the tensile strength at the time of producing carbon fibers is remarkably reduced.

In order to produce the desired isotropic pitch in the present invention, a raw material which satisfies the content of the above-described compounds and their ratios must be produced in the intermediate stage. For example, Ar ₁ , The isotropic pitch can be produced by controlling the content of Ar ₂ and Ar ₃ and Ar ₁ / Ar _2. More specifically, the content of indene, naphthalene and biphenyl, The isotropic pitch desired in the invention can be produced.

When the raw material partially satisfying the content of the compound and the ratio described above is produced in the intermediate stage, the radioactivity of the isotropic pitch is poor and the strength of the finally produced carbon fiber can be rapidly decreased and the elongation can also be reduced . For example, biphenyls / naphthalenes are important in the content ratio. If the above range is exceeded, the physical properties and radioactivity of the isotropic pitch are not good even if the other conditions are satisfied, and the strength of the carbon fiber produced therefrom may be drastically reduced have.

According to one embodiment of the present invention, when the raw material partially satisfying the above content and the ratio thereof is produced in the intermediate stage, the isotropic pitch produced is melt spinning, but the radioactivity is poor due to high single yarn frequency. According to another embodiment of the present invention, the carbon fiber produced from the isotropic pitch has poor strength and elongation even though the single yarn frequency is not high. On the other hand, according to one embodiment of the present invention, when the above content and the raw materials satisfying the above conditions are generated in the intermediate stage, the carbon fibers having a strength of not less than 1.5 GPa and an elongation of not less than 2% An isotropic pitch having no single yarn frequency can be produced.

When the raw materials satisfying the above-described contents of the compound of the raw materials and the ratio thereof are produced in the intermediate stage, it is possible to produce isotropic pitches having very excellent radioactive properties, and the carbon fibers produced therefrom have high strength and high elasticity properties Satisfies.

The isotropic pitch produced in the present invention has a softening point (° C.) of 250 to 280, preferably 260 to 270, and an average molecular weight (Mw) of 1450 to 2850, preferably 1600 to 2600, more preferably 1700 to 2500 . The physical properties of the isotropic pitches of the present invention have an influence on the properties of the radioactive fibers and the properties of the tubular fibers produced therefrom. The specific properties of the isotropic pitches exhibiting the above physical properties are also dependent on the radioactivity and the properties of the carbon fibers .

The isotropic pitch produced in the present invention is capable of melt spinning and has excellent radioactivity in the case of fiber spinning with no single spinning or extremely rare spinning. Melt spinning is a method of producing polymeric materials or pitches as continuous fibers by melting them, and it is unnecessary to use expensive solvents required for fiber spinning, which is a very economical method that can simplify the configuration of the spinning process and significantly reduce costs to be. In order to enable the above-mentioned melt spinning for carbon fiber production, the spinnability of the pitch should be excellent. The isotropic pitch produced according to the present invention is very excellent in radioactivity, so that melt spinning for carbon fiber production is possible and single yarn is extremely rare or does not occur . In addition, the isotropic pitch capable of melt-spinning according to the present invention is superior to isotropic pitches in producing short fibers through conventional melt-blowing, so that carbon fibers having high strength and high elasticity can be produced have.

According to one embodiment of the present invention, the frequency of the break in the melt spinning at 700 rpm for 20 minutes continuously was measured as a single yarn frequency, and as a result, the single yarn frequency was zero and the radioactivity was excellent.

The isotropic pitch produced in the present invention is capable of producing carbon fibers having high strength and high elasticity, and has excellent strength and elongation percentage higher than those of conventional carbon fibers. Conventional isotropic pitch based carbon fibers have been used as general purpose carbon fibers due to their low strength. However, carbon fibers manufactured from the isotropic pitch of the present invention have excellent strength and high elongation so that anisotropic pitch type carbon fibers or PAN type carbon fibers are used Carbon composite materials.

According to one embodiment of the present invention, a carbon fiber having an extremely high strength of 1.5 GPa or more and an elongation of 2% or more at an isotropic pitch produced by the production method of the present invention can be produced. The carbon fiber having such properties satisfies the strength that can be applied to the carbon composite material, the material, and the material, and has a wide range of application.

That is, the isotropic pitch of the present invention, which is capable of melt spinning and is very economical, capable of producing high strength and high elasticity carbon fibers, has an effect that can not be obtained from the conventional isotropic pitch.

The raw materials produced in the intermediate stages described above may be obtained by a method of pre-treating a raw material containing at least one of naphtha-decomposed residual oil, petroleum-derived heavy crude or coal tar oil or a raw material containing a specified range of compound composition And can be generated at an intermediate stage.

The raw material The pretreatment method preferably includes heating and fractionation at normal pressure. The heating can be carried out by heating at 160 to 240 ° C, preferably 175 to 235 ° C, until no further volatiles are generated. When heated at the above temperature, the raw material produced in the intermediate step of the production method of the present invention may satisfy the content of the compound for producing an isotropic pitch and the ratio thereof. Specifically, when the temperature is outside the range, the naphthalenes may be insufficiently converted to naphthalenes because the naphthalenes are not sufficiently converted to the naphthalenes. And the content of compounds containing indene or three or more aromatic rings or other compounds may be excessively reduced or increased. In addition, the biphenyl content may be excessively increased, and raw materials which are not suitable for the isotropic pitch having physical properties and radioactive properties to be produced may be produced in the intermediate stage.

The method of producing the isotropic pitch satisfying the condition of the raw material generated in the above-described intermediate step,

(a) preparing a raw material that satisfies the following formulas (1) to (4) by pretreating a raw material containing at least one of naphtha-decomposed residual oil, petroleum heavy oil or coal tar oil at 160 to 240 캜; ; And

20.0%? Ar ₁ ? 45.0% --- (1)

_{50.0% ≤ Ar 2 ≤ 70.0%} --- (2)

_{0.0% ≤ Ar 3 ≤ 10.0%} --- (3)

0.30 < Ar ₁ / Ar ₂ < 0.75 - (4)

(b) thermal polymerization and heating the raw material prepared in (a) above.

According to one embodiment of the present invention, when the pretreatment temperature is 150 캜 or less, the above-mentioned formulas (1) and (4) are not satisfied and the content of indenter is excessively large while the content of naphthalene is excessively small. According to another embodiment of the present invention, when the pretreatment temperature is 250 ° C or higher, the formula (4) is not satisfied, and the content of biphenyls is excessively high while the content of naphthalenes is excessively low.

According to one embodiment of the present invention, even if the above-mentioned conditions (1), (2) and (3) are satisfied, if the content (4) representing the content ratio is not satisfied, the frequency of single yarns during melt spinning at an isotropic pitch is high, The strength of the carbon fiber is less than 1.0 GPa. According to another embodiment, the strength of the carbon fiber produced from the isotropic pitch is less than 1.0 GPa if the above-mentioned (4) is satisfied and the content ratio satisfies the above (1) and (2) The elongation rate drops to less than 2%. According to another embodiment, if the above (1) or (3) is not satisfied even if the above-mentioned conditions (2) and (4) are satisfied, the frequency of single yarns during melt spinning at an isotropic pitch is high and the elongation And falls to less than 2%.

The naphthalene content of the raw material produced in the intermediate stage satisfying (1) to (4) of the above production method is 20.0 to 60.0% based on the total amount of the raw materials, the biphenyl content is 5.0% / Naphthalenes is preferably less than 0.20. According to one embodiment of the present invention, when the content of naphthalenes, biphenyls, and their contents is within the above-mentioned preferable ranges, but when (1) to (4) are not satisfied, The frequency may be high, the strength of the carbon fiber to be produced may be significantly lowered, or the elongation rate may be decreased. According to another embodiment, even when the content ratio of the naphthalenes and biphenyls satisfies the above-mentioned preferable range, even when the content of the naphthalenes or biphenyls does not satisfy the above-mentioned preferable range, the frequency of single yarns at the melt spinning of the isotropic pitch is high And the strength of the carbon fiber produced is significantly lowered or the elongation is lowered.

to the next, A raw material containing at least one or more of naphtha cracking residues, petroleum residues or coal tar residues Depending on the content of the contained compounds and their content ratios, the raw materials for producing isotropic pitch in the production process of the present invention can be produced in the intermediate stage.

Specifically, the compound containing one aromatic ring is preferably 30.0 to 60.0% of the total amount of the raw material. Among these, indene may be partially converted into naphthalene during the pretreatment process, but since it is a substance having strong reactivity, there is a need to limit the content of the naphthalene which can adversely affect physical properties and radioactivity of the isotropic pitch produced thereafter. The content of indenter is 25.0 to 70.0%, preferably 30.0 to 65.0%, based on the total amount of the compound containing one aromatic ring, and is 5.0 to 50.0%, preferably 10.0 to 40.0% of the total amount of the raw material. The alkenylbenzenes, which are olefins, also have very strong reactivities similar to those of indenes, which may adversely affect physical properties and radioactivity of the isotropic pitches produced thereafter. However, they are mostly volatilized during the pretreatment, 3.0% or less.

The compound containing two aromatic rings is at least 30.0%, preferably 35.0 to 80.0%, more preferably 55.0 to 70.0% of the total amount of the raw material. Among them, the content of naphthalenes should be at least 30.0%, preferably at least 35.0%, relative to the total amount of the compounds containing two aromatic rings, and from 5.0 to 60.0%, preferably from 10.0 to 45.0% A raw material containing sufficient naphthalene species can be produced in the intermediate stage. The biphenyls do not contribute greatly to the polymerization reaction, and the lower the content, the better the content is 15.0% or less, preferably 10.0% or less of the total amount of the compounds containing two aromatic rings, and 10.0% Preferably not more than 5.0%, more preferably not to the extent that it can not be measured.

A compound containing three aromatic rings and a compound containing four or more aromatic rings may not participate in the polymerization reaction or may be a condensed aromatic compound having an excessively large number of rings due to the influence of an olefin such as alkenylbenzene and a lead- To form a ring compound. That is, in the isotropic pitch production method, a desired raw material may not be produced at an intermediate stage of the isotropic pitch. The compound containing three aromatic rings is preferably not more than 8.0%, preferably not more than 5.0%, more preferably not more than 8% of the total amount of the raw material, and the compound containing four or more aromatic rings 3.0% or less, and it is preferable to include or not contain a very small amount so that it can not be measured.

Each of the content ratio of the compound containing an aromatic ring is in _{0.50 <Ar '1 / Ar'} 2 <2.00, preferably _{0.55 <Ar '1 / Ar'} 2 <1.75 in Ar _'1 / Ar' _2. Next, in Ar ' ₁ / Ar' ₃ , 5.00 <Ar ' ₁ / Ar' ₃ <30.00, preferably 8.00 <Ar ' ₁ / Ar' ₃ <25.00. And to the _{Ar '3 / Ar' 2 5.00} <Ar '3 / Ar' 2 <20.00, preferably from _{10.00 <Ar '3 / Ar'} 2 <15.00 to be. Wherein Ar ' ₁ is a content of a compound containing one aromatic ring with respect to a total amount of the raw material, Ar' ₂ is a content of a compound containing two aromatic rings with respect to the total amount of the raw material, Ar ' ₃ represents the content of the compound containing three aromatic rings relative to the total amount of the raw material. Also, a compound containing four or more aromatic rings relative to the total amount of the above raw materials may be represented by Ar ' ₄ .

A raw material containing at least one of naphtha-decomposed residual oil, petroleum-derived heavy oil or coal tar oil The content ratio of indene and naphthalene with respect to the total amount is 0.20 < indene / naphthalene < 4.00, preferably 0.25 <

The ratio of biphenyls / naphthalenes to biphenyls / naphthalenes <0.15, preferably biphenyls / naphthalenes <0.10, based on the total amount of the compounds containing two aromatic rings in the raw material.

It is preferable to use a raw material that satisfies the content of the compound contained in the raw material and the ratio thereof. For example, Ar ' ₁ , Ar 'and Ar ₂ content of' ₁ / Ar 'through the control of the _two may meet the material to be produced in an intermediate step of the present invention. More specifically, the content and ratio of specific compounds such as indene, naphthalene, biphenyl and the like can be further controlled.

According to an embodiment of the present invention, when the content of the compound included in the raw material and the naphtha decomposition residue partially satisfying the ratio are used, the content and the ratio of the raw material generated in the intermediate step may not be appropriate. For example, indenter / naphthalene is important in the content ratio of the raw material. If the ratio is outside the preferable range, the content and ratio of the raw material generated in the intermediate stage may not be appropriate even if other conditions are satisfied.

In the present invention, the thermal polymerization proceeding after the raw material production can proceed at 350 to 380 ° C for 0.1 to 2 hours, but is not limited thereto. The thermal polymerization process can proceed in an inert gas atmosphere during the process and can proceed by collecting gaseous by-products generated during nitrogen and poly-condensation. When the reaction temperature exceeds 380 ° C, an insoluble solid content is generated, or an excess amount of mesophases exceeding the range of uniform isotropic pitch is produced, or the coking is progressed, so that carbon fiber Non-uniform carbon fibers may be produced during manufacture.

Next, the heating may be a process for promoting evaporation to suppress mesophase formation, and to produce a spinnable isotropic pitch. The heating can proceed with conventional thin film distillation methods, which not only inhibits the formation of mesophases but also eliminates the need for additional processes to remove insoluble solids.

The isotropic pitch produced according to the production method of the present invention can produce carbon steel oil having a specific range of molecular weight, high softening point, and excellent radioactivity, and having high strength and high elasticity.

The production of carbon fibers may be manufactured through a melt-spinning stabilization step and a carbonization step, but is not limited thereto. A bundling agent for preventing adhesion between fibers can be used in the step of manufacturing carbon fibers, and a surface treatment and a sizing step after the carbonization step can be added to improve the adhesion with the matrix resin when the composite material is manufactured. In addition, the spinning conditions can be freely changed depending on the number of holes of the radiator or the capacity of the manufacturing facility.

Hereinafter, a method for producing an isotropic pitch according to the present invention will be described in more detail with reference to examples. In the following examples, the examples and comparative examples are examples for preferably practicing the present invention, but the present invention is not limited thereto.

How to measure property

1. Carbon and hydrogen atomic ratio (H / C)

Analysis with CHNS element analyzer

2. The degree of aromatization (fa)

Analysis by &lt; ¹³ &gt; C NMR (ASTM D5292)

3. Composition of raw materials and raw materials

2D-GC analysis

4. Average molecular weight (Mw)

The average molecular weight was analyzed by TOF-MS, the average molecular weight of the pitch was analyzed by GPC

5. Viscosity (Pa · s)

Viscosity is measured by TMA (Thermo Mechanical Analyzer)

6. Softening Point (℃)

The softening point is measured by TMA (Thermo Mechanical Analyzer).

7. Yield

The yield was calculated by the weight of the final pitch obtained relative to the weight of the naphtha cracked residual oil added.

8. Mechanical properties

In order to calculate the tensile strength (GPa) and elongation (%), a stress-strain curve was measured with a universal test machine (UTM) equipped with a 2N load cell for a sample of carbon fiber. The tensile strength was measured by an electron microscope &Lt; / RTI &gt; was calculated from the diameter of the fibers analyzed by the &lt;

&Lt; Examples 1 to 4 > and < Comparative Examples 1 to 3 &

Naphtha Cracker Bottom Oil (NCBO) having the composition and degree of aromatization shown in Tables 1 and 2 was prepared as a raw material.

carbon
(C,% by weight) Hydrogen
(H, wt%) nitrogen
(N,% by weight) Sulfur (S, wt%) H / C (atomic ratio) 92.48 7.32 0.10 0.13 0.95

Aliphatic carbide (%) Aromatic carbide (%) The degree of aromaticization (fa) Methyl carbon
(CH3, Ar-CH3) Methylene carbon
(naphthalene) Unsubstituted carbon
(Ar-H) Quaternary carbon Substituted carbon
(Ar-C) 5.85 16.86 49.70 12.38 15.21 0.74

In Examples 1 to 4, the prepared NCBO was pretreated by atmospheric distillation at 190 ° C, 200 ° C, 210 ° C, and 220 ° C, respectively. Comparative Example 1 was not pretreated. In Comparative Examples 2 and 3, And then pretreated at 250 ° C to produce a raw material. The physical properties of the raw materials produced in the intermediate stages according to the respective Examples and Comparative Examples are shown in Table 3 below.

Atomic ratio
(H / C) Aromatization degree
(fa) Average molecular weight
(Mw) Comparative Example 1 0.95 0.74 170 Comparative Example 2 0.95 0.75 180 Example 1 0.95 0.78 195 Example 2 0.94 0.84 220 Example 3 0.94 0.86 245 Example 4 0.96 0.88 260 Comparative Example 3 0.94 0.91 295

The compositions of the compounds contained in the raw materials produced in the intermediate stage according to the respective Examples and Comparative Examples are shown in Tables 4 to 7 below.

Pretreatment (℃) saturation
Carbide Aromatic ring
Including 1
(Ar ₁ ) Aromatic ring
Including 2
(Ar ₂ ) Aromatic ring
Includes 3
(Ar ₃ ) Aromatic ring
Include 4 or more
(Ar ₄ ) Total amount (%) Comparative Example 1 - 1.8 51.8 43.0 3.4 0.0 100 Comparative Example 2 150 1.6 48.3 46.3 3.8 0.0 Example 1 190 1.3 38.0 56.2 4.5 0.0 Example 2 200 1.3 30.0 61.4 7.3 0.0 Example 3 210 2.6 33.1 57.2 7.1 0.0 Example 4 220 1.8 30.2 59.7 8.3 0.0 Comparative Example 3 250 1.5 27.4 55.3 13.8 2.1

Pretreatment (℃) One aromatic ring containing compound Alkylbenzene Alkenylbenzene Indan derivatives Indenter Etc Total amount (%) Comparative Example 1 - 7.0 5.5 3.3 52.6 31.6 100 Comparative Example 2 150 5.7 0.0 4.2 54.1 36.0 Example 1 190 2.6 0.0 5.7 65.9 25.8 Example 2 200 8.3 0.0 13.3 56.7 21.7 Example 3 210 10.0 0.0 9.4 58.4 22.2 Example 4 220 8.4 0.0 11.7 44.3 35.6 Comparative Example 3 250 9.3 0.0 16.4 33.2 41.1

Pretreatment (℃) Compound containing two aromatic rings Biphenyls Naphthalene Etc Total amount (%) Comparative Example 1 - 0.5 62.5 37.4 100 Comparative Example 2 150 0.6 64.2 35.2 Example 1 190 0.7 85.3 14.0 Example 2 200 7.7 51.9 40.4 Example 3 210 6.0 53.2 40.8 Example 4 220 7.2 51.8 41.0 Comparative Example 3 250 14.8 33.7 51.5

Saturated hydrocarbons Aromatic ring
Including 1 Aromatic ring
Including 2 Aromatic ring
Three
include Aromatic ring
4
More than
include Total amount
(%) Alkylbenzene Alkenylbenzene Inflorescence Indenter Etc Biphenyls Naphthalene Etc Comparative Example 1 1.8 3.6 2.8 1.7 27.2 16.4 0.2 26.9 16.1 3.4 0.0 100 Comparative Example 2 1.6 2.8 0.0 2.0 26.1 17.4 0.3 29.7 16.3 3.8 0.0 100 Example 1 1.3 1.0 0.0 2.2 25.0 9.8 0.4 47.9 7.9 4.5 0.0 100 Example 2 1.3 2.5 0.0 4.0 17.0 6.5 4.7 31.9 24.8 7.3 0.0 100 Example 3 2.6 3.3 0.0 3.1 19.3 7.4 3.4 30.4 23.3 7.1 0.0 100 Example 4 1.8 2.5 0.0 3.5 13.4 10.8 4.3 30.9 24.5 8.3 0.0 100 Comparative Example 3 1.5 2.5 0.0 4.5 9.1 11.3 8.2 18.6 28.5 13.8 2.1 100

Thereafter, the raw material was filtered to remove the solid matter, and 100 parts by weight of the material was put into a metal container and heated at 370 ° C for 0.5 hour. Thereafter, the mixture was put into a thin film evaporator, and isotropic pitch was prepared by heating at 340 DEG C for 30 minutes in a vacuum atmosphere. The average molecular weight, softening point and viscosity of the prepared isotropic pitches are shown in Table 23.

&Lt; Examples 5 to 7 > and < Comparative Examples 4 to 5 >

Naphtha Cracker Bottom Oil (NCBO) having the chemical compositions of Tables 9 to 12 was prepared as a raw material with physical properties shown in Table 8 below.

Atomic ratio (H / C) The degree of aromaticization (fa) Average molecular weight (Mw) Comparative Example 4 1.12 0.60 120 Example 5 0.96 0.74 170 Example 6 1.10 0.65 140 Example 7 0.93 0.80 220 Comparative Example 5 0.92 0.85 260

saturation
Carbide Aromatic ring
Including 1
(Ar ' ₁ ) Aromatic ring
Including 2
(Ar ' ₂ ) Aromatic ring
Includes 3
(Ar ' ₃ ) Aromatic ring
Include 4 or more
(Ar ' ₄ ) Total amount
(%) Comparative Example 4 2.3 62.4 33.2 2.1 0 100 Example 5 1.8 51.8 43.1 3.4 0 Example 6 1.7 59.8 35.7 2.8 0 Example 7 1.4 34.2 59.8 4.1 0.5 Comparative Example 5 1.5 29.6 56.3 8.4 4.2

Table 9 shows that in each of the examples, Ar ' ₁ was 34.2 to 51.8%, Ar' ₂ was 35.7 to 59.8%, Ar ' ₃ was less than 4.1%, and Ar' ₄ was less than 0.5%. Among these contents, Ar ' ₁ / Ar' ₂ ranged from 0.57 to 1.67, Ar ' ₃ / Ar' ₂ ranged from 0.068 to 0.078 and Ar ' ₁ / Ar' ₃ ranged from 8.34 to 21.35.

One aromatic ring containing compound Total amount
(%) Alkylbenzene Alkenylbenzene Indan derivatives Indenter Etc Comparative Example 4 6.1 4.6 3.4 66.0 19.9 100 Example 5 6.9 5.4 3.3 52.7 31.7 Example 6 5.2 4.0 3.2 65.0 22.7 Example 7 8.5 6.7 6.1 31.0 47.7 Comparative Example 5 10.8 8.4 8.1 29.0 43.6

Compound containing two aromatic rings Total amount (%) Biphenyls Naphthalene Etc Comparative Example 4 1.2 34.0 64.8 100 Example 5 0.5 62.1 37.4 Example 6 0.3 35.0 64.7 Example 7 6.5 68.9 24.6 Comparative Example 5 11.5 73.7 14.7

Saturated carbide Aromatic ring
Including 1 Aromatic ring
Including 2 Aromatic
With three rings Aromatic ring
Include 4 or more Total amount
(%) Alkylbenzene Alkenylbenzene Inflorescence Indenter Etc Biphenyls Naphthalene Etc Comparative Example 4 2.3 3.8 2.9 2.1 41.2 12.4 0.4 11.3 21.5 2.1 0 100 Example 5 1.8 3.6 2.8 1.7 27.3 16.4 0.2 26.7 16.1 3.4 0 100 Example 6 1.7 3.1 2.4 1.9 38.9 13.5 0.1 12.5 23.1 2.8 0 100 Example 7 1.4 2.9 2.3 2.1 10.6 16.3 3.9 40.2 15.7 4.1 0.5 100 Comparative Example 5 1.5 3.2 2.5 2.4 8.6 12.9 6.5 41.5 8.3 8.4 4.2 100

Table 12 shows that in each of the main compounds, the content of indenter was 10.6 to 38.9%, the content of naphthalene was 12.5 to 40.2%, and the content of biphenyl was 0.1 to 3.9%. Among them, the content of indene / naphthalene and that of biphenyl / naphthalene ranged from 0.26 to 3.11 and 0.007 to 0.094, respectively.

All of the prepared NCBOs corresponding to Examples 5 to 7 and Comparative Examples 4 to 5 were pre-treated at 200 ° C by atmospheric distillation. The physical properties of the raw materials produced after the pretreatment according to the respective Examples and Comparative Examples are shown in Table 13 below.

Atomic ratio
(H / C) Aromatization degree
(fa) Average molecular weight
(Mw) Comparative Example 4 1.11 0.65 150 Example 5 0.94 0.84 220 Example 6 1.05 0.82 170 Example 7 0.93 0.86 250 Comparative Example 5 0.92 0.89 270

The compositions of the compounds contained in the raw materials produced in the intermediate stage according to the respective Examples and Comparative Examples are shown in Tables 14 to 17 below.

Saturated carbide Aromatic ring
Including 1
(Ar ₁ ) Aromatic ring
Including 2
(Ar ₂ ) Aromatic ring
Includes 3
(Ar ₃ ) Aromatic ring
Include 4 or more
(Ar ₄ ) Total amount
(%) Comparative Example 4 0.9 41.2 52.3 5.6 0 100 Example 5 1.3 30.0 61.4 7.3 0 Example 6 1.5 36.2 55.5 6.8 0 Example 7 1.2 22.5 66.6 7.4 2.3 Comparative Example 5 1.3 19.8 61.9 10.5 6.5

One aromatic ring containing compound Alkylbenzene Alkenylbenzene Indan derivatives Indenter Etc Total amount (%) Comparative Example 4 7.3 0 8.3 71.6 12.9 100 Example 5 8.3 0 13.3 56.7 21.6 Example 6 7.7 0 10.5 70.2 11.6 Example 7 13.8 0 20.9 40.4 24.9 Comparative Example 5 19.2 0 24.7 34.3 21.7

Compound containing two aromatic rings Biphenyls Naphthalene Etc Total amount (%) Comparative Example 4 8.0 27.3 64.6 100 Example 5 7.7 52.0 40.4 Example 6 6.8 39.1 54.1 Example 7 7.4 73.9 18.8 Comparative Example 5 12.6 76.0 11.4

Saturated hydrocarbons Aromatic ring
Including 1 Aromatic ring
Including 2 Aromatic
ring
Includes 3 Aromatic
ring
Include 4 or more Total amount (%) Alkylbenzene Alkenylbenzene Inflorescence Indenter Etc Biphenyls Naphthalene Etc Comparative Example 4 0.9 3.0 0.0 3.4 29.5 5.3 4.2 14.3 33.8 5.6 0.0 100 Example 5 1.3 2.5 0.0 4.0 17.0 6.5 4.7 31.9 24.8 7.3 0.0 100 Example 6 1.5 2.8 0.0 3.8 25.4 4.2 3.8 21.7 30.0 6.8 0.0 100 Example 7 0.9 3.1 0.0 4.7 9.1 5.6 4.9 49.2 12.5 7.4 2.3 100 Comparative Example 5 1.3 3.8 0.0 4.9 6.8 4.3 7.8 47.0 7.1 10.5 6.5 100

Thereafter, the raw material was filtered to remove the solid matter, and 100 parts by weight of the material was put into a metal container and heated at 370 ° C for 0.5 hour. Thereafter, the mixture was put into a thin film evaporator, and isotropic pitch was prepared by heating at 340 DEG C for 30 minutes in a vacuum atmosphere. The average molecular weight, softening point and viscosity of the prepared isotropic pitches are shown in Table 23.

Analysis of the raw materials generated in the intermediate stage

Table 18 below shows the physical properties of the raw materials produced in the intermediate steps of all Examples and Comparative Examples.

Atomic ratio
(H / C) Aromatization degree
(fa) Average molecular weight
(Mw) Comparative Example 1 0.95 0.74 170 Comparative Example 2 0.95 0.75 180 Example 1 0.95 0.78 195 Example 2 0.94 0.84 220 Example 3 0.94 0.86 245 Example 4 0.96 0.88 260 Comparative Example 3 0.94 0.91 295 Comparative Example 4 1.11 0.65 150 Example 5 0.94 0.84 220 Example 6 1.05 0.82 170 Example 7 0.93 0.86 250 Comparative Example 5 0.92 0.89 270

In Table 18, the degree of aromatization in each of the examples ranged from 0.78 to 0.88 and the average molecular weight ranged from 170 to 260.

Tables 19 to 22 below show the compositions of the compounds contained in the raw materials produced in the intermediate steps of all Examples and Comparative Examples.

Saturated carbide Aromatic ring
Including 1
(Ar ₁ ) Aromatic ring
Including 2
(Ar ₂ ) Aromatic ring
Includes 3
(Ar ₃ ) Aromatic ring
Include 4 or more
(Ar ₄ ) Total amount
(%) Comparative Example 1 1.8 51.8 43.0 3.4 0.0 100 Comparative Example 2 1.6 48.3 46.3 3.8 0.0 Example 1 1.3 38.0 56.2 4.5 0.0 Example 2 1.3 30.0 61.4 7.3 0.0 Example 3 2.6 33.1 57.2 7.1 0.0 Example 4 1.8 30.2 59.7 8.3 0.0 Comparative Example 3 1.5 27.4 55.3 13.8 2.1 Comparative Example 4 0.9 41.2 52.3 5.6 0 Example 5 1.3 30.0 61.4 7.3 0 Example 6 1.5 36.2 55.5 6.8 0 Example 7 1.2 22.5 66.6 7.4 2.3 Comparative Example 5 1.3 19.8 61.9 10.5 6.5

From Table 19 the content of the compound containing an aromatic ring in each embodiment is Ar ₁ is 22.5 ~ 38.0%, Ar ₂ is 55.5 ~ 66.6%, Ar ₃ is 4.5 ~ 8.3%, Ar ₄ belonged to 0.0 ~ 2.3% . Of these contents, Ar ₁ / Ar ₂ ranged from 0.33 to 0.67, Ar ₃ / Ar ₂ ranged from 0.08 to 0.13, and Ar ₁ / Ar ₃ ranged from 3.04 to 8.44.

One aromatic ring containing compound Total amount
(%) Alkylbenzene Alkenylbenzene Indan derivatives Indenter Etc Comparative Example 1 7.0 5.5 3.3 52.6 31.6 100 Comparative Example 2 5.7 0.0 4.2 54.1 36.0 Example 1 2.6 0.0 5.7 65.9 25.8 Example 2 8.3 0.0 13.3 56.7 21.7 Example 3 10.0 0.0 9.4 58.4 22.2 Example 4 8.4 0.0 11.7 44.3 35.6 Comparative Example 3 9.3 0.0 16.4 33.2 41.1 Comparative Example 4 7.3 0 8.3 71.6 12.9 Example 5 8.3 0 13.3 56.7 21.6 Example 6 7.7 0 10.5 70.2 11.6 Example 7 13.8 0 20.9 40.4 24.9 Comparative Example 5 19.2 0 24.7 34.3 21.7

Compound containing two aromatic rings Total amount
(%) Biphenyls Naphthalene Etc Comparative Example 1 0.5 62.5 37.4 100 Comparative Example 2 0.6 64.2 35.2 Example 1 0.7 85.3 14.0 Example 2 7.7 51.9 40.4 Example 3 6.0 53.2 40.8 Example 4 7.2 51.8 41.0 Comparative Example 3 14.8 33.7 51.5 Comparative Example 4 8.0 27.3 64.6 Example 5 7.7 52.0 40.4 Example 6 6.8 39.1 54.1 Example 7 7.4 73.9 18.8 Comparative Example 5 12.6 76.0 11.4

Saturated hydrocarbons Aromatic ring
Including 1 Aromatic ring
Including 2 With three aromatic rings Aromatic ring
Include 4 or more Total amount
(%) Alkylbenzene Alkenylbenzene Inflorescence Indenter Etc Biphenyls Naphthalene Etc Comparative Example 1 1.8 3.6 2.8 1.7 27.2 16.4 0.2 26.9 16.1 3.4 0.0 100 Comparative Example 2 1.6 2.8 0.0 2.0 26.1 17.4 0.3 29.7 16.3 3.8 0.0 100 Example 1 1.3 1.0 0.0 2.2 25.0 9.8 0.4 47.9 7.9 4.5 0.0 100 Example 2 1.3 2.5 0.0 4.0 17.0 6.5 4.7 31.9 24.8 7.3 0.0 100 Example 3 2.6 3.3 0.0 3.1 19.3 7.4 3.4 30.4 23.3 7.1 0.0 100 Example 4 1.8 2.5 0.0 3.5 13.4 10.8 4.3 30.9 24.5 8.3 0.0 100 Comparative Example 3 1.5 2.5 0.0 4.5 9.1 11.3 8.2 18.6 28.5 13.8 2.1 100 Comparative Example 4 0.9 3.0 0.0 3.4 29.5 5.3 4.2 14.3 33.8 5.6 0.0 100 Example 5 1.3 2.5 0.0 4.0 17.0 6.5 4.7 31.9 24.8 7.3 0.0 100 Example 6 1.5 2.8 0.0 3.8 25.4 4.2 3.8 21.7 30.0 6.8 0.0 100 Example 7 0.9 3.1 0.0 4.7 9.1 5.6 4.9 49.2 12.5 7.4 2.3 100 Comparative Example 5 1.3 3.8 0.0 4.9 6.8 4.3 7.8 47.0 7.1 10.5 6.5 100

Table 22 shows that the alkenylbenzene was largely volatilized in the raw material through pretreatment of the naphtha-decomposing residual oil, and the content of alkylbenzene and phosphorus was decreased as a whole. On the other hand, the total amount of the compounds including the indanols, biphenyls and three or more aromatic rings increased slightly, and the content of naphthalenes increased greatly overall. In each of the examples, the content of the main compound of the raw material was all volatilized to the extent that it was not measured in the case of alkenylbenzene, the content of indanols was 2.2-4.7%, the content of indenes was 9.1-25.4%, the content of biphenyls was 0.4-4.9% Naphthalenes belonged to 21.7 ~ 49.2%. The ratios of indene and naphthalenes (indenes / naphthalenes) were 0.18 to 1.17, and the ratios of biphenyls to naphthalenes (biphenyls / naphthalenes ) Ranged from 0.08 to 0.13.

Manufactured Isotropic  Property Analysis

Table 23 below shows the physical properties of isotropic pitches prepared according to all Examples and Comparative Examples.

Softening point (℃) Average molecular weight (Mw) Viscosity (Pa · s) Comparative Example 1 265 1350 375 Comparative Example 2 263 1400 382 Example 1 265 1750 411 Example 2 260 2200 342 Example 3 265 2350 194 Example 4 260 2500 360 Comparative Example 3 270 2950 445 Comparative Example 4 260 1500 289 Example 5 265 2200 342 Example 6 263 1800 324 Example 7 269 2500 368 Comparative Example 5 280 2800 402

As shown in Table 23, the softening point of each example belonged to 265 to 269 DEG C and the average molecular weight belonged to 1750 to 2500, and the viscosity belonged to 194 to 411. [

Isotropic pitch Carbon fiber Whether melt-spinning Single yarn frequency Diameter (탆) Tensile Strength (GPa) Elongation (%) Comparative Example 1 O 0 7.40 0.7 2.5 Comparative Example 2 O 0 7.60 1.1 2.6 Example 1 O 0 8.10 2.0 2.3 Example 2 O 0 7.30 1.7 2.3 Example 3 O 0 6.80 1.6 2.9 Example 4 O 0 7.10 1.5 2.1 Comparative Example 3 0 0 8.70 0.9 1.5 Comparative Example 4 O 7 times 6.89 0.8 2.8 Example 5 O 0 7.34 1.7 2.3 Example 6 O 0 7.02 1.5 2.1 Example 7 O 0 8.21 1.6 2.2 Comparative Example 5 0 5 times 8.32 1.1 1.9 The single yarn frequency is measured by the frequency of breaks during 20 minutes continuous irradiation.

Table 24 shows that all of the examples were capable of melt spinning and did not generate single yarn during spinning, and the tensile strength of carbon fiber was at least 1.5 GPa and elongation at least 2%. On the other hand, the comparative example shows that although the melt spinning was possible but the single yarn was generated and the elongation percentage was less than 2.0% or the tensile strength of the carbon fiber was at most 1.1 GPa even without single yarn occurrence,

Claims (13)

(a) preparing a raw material that satisfies the following formulas (1) to (4) by pretreating a raw material containing at least one of naphtha-decomposed residual oil, petroleum heavy oil or coal tar oil at 160 to 240 캜; ; And
20.0%? Ar ₁ ? 45.0% --- (1)
_{50.0% ≤ Ar 2 ≤ 70.0%} --- (2)
_{0.0% ≤ Ar 3 ≤ 10.0%} --- (3)
0.30 < Ar ₁ / Ar ₂ < 0.75 - (4)
(b) thermally polymerizing and heating the raw material prepared in (a) above;
Of the isotropic pitch.
(Ar ₁ is a content of a compound containing one aromatic ring with respect to the total amount of the raw materials, Ar ₂ is a content of a compound containing two aromatic rings relative to the total amount of the raw materials, Ar ₃ is three aromatic The content of the compound including the ring.) The method according to claim 1,
Wherein the raw material satisfies 20.0%? Naphthalene? 60.0% and 0.0%? Biphenyl? 5.0% based on the total amount. 3. The method of claim 2,
Wherein the raw material satisfies the biphenyl / naphthalene type < 0.20. The method according to claim 1,
Wherein the raw material satisfies an Ar _4? 5.0%.
(Ar ₄ is a content of a compound containing four or more aromatic rings relative to the total amount of raw materials). The method according to claim 1,
Wherein the raw material satisfies Ar ₃ / Ar ₂ < 0.15. 6. The method according to any one of claims 1 to 5,
Wherein the raw material containing at least one of the naphtha-decomposed residual oil, petroleum-derived heavy crude oil and coal tar oil fraction satisfies the following formulas (1) to (3).
30.0%? Ar ' ₁ ? 60.0% --- (1)
55.0%? Ar? ₂ ? 70.0% (2)
0.55 &lt; Ar ' ₁ / Ar' ₂ &lt; 1.75 - (3)
(Ar ' ₁ is the content of the compound containing one aromatic ring with respect to the total amount of the raw material, and Ar' ₂ is the content of the compound containing two aromatic rings with respect to the total amount of the raw material). The method according to claim 6,
Wherein the raw material satisfies 10.0% ≤ indenter ≤ 40.0% and 10.0% ≤ naphthalene ≤ 45.0% based on the total amount. 8. The method of claim 7,
Wherein the raw material satisfies 0.25 < ternary / naphthalene type < 3.50. The method according to claim 6,
Wherein the raw material satisfies Ar ' ₃ ? 5.0%.
(Ar ' ₃ is a content of a compound containing three aromatic rings relative to the total amount of the raw material). 10. The method of claim 9,
Wherein the raw material satisfies Ar ' _4? 3.0%.
(Ar ' ₄ is a content of a compound containing four or more aromatic rings relative to the total amount of the raw material). 6. The method according to any one of claims 1 to 5,
Wherein the isotropic pitch has an average molecular weight of 1450 to 2850. &lt; Desc / Clms Page number 24 &gt; 12. The method of claim 11,
Wherein the isotropic pitch is a softening point of 250 to 280. &lt; RTI ID = 0.0 &gt; 25. &lt; / RTI &gt; A raw material for producing an isotropic pitch satisfying the following formulas (1) to (7) by heat treatment and fractionation of a raw material containing at least one of naphtha cracked residual oil, petroleum heavy crude oil and coal tar oil, A raw material for producing an isotropic pitch which is spinnable and has an average molecular weight of 1450 to 2850 and a softening point of 250 to 280;
20.0%? Ar ₁ ? 45.0% --- (1)
_{50.0% ≤ Ar 2 ≤ 70.0%} --- (2)
_{0% ≤ Ar 3 ≤ 10.0%} --- (3)
20.0%? Naphthalenes? 60.0% (4)
0%? Biphenyl? 5.0% --- (5)
0.30 < Ar ₁ / Ar ₂ < 0.75 - (6)
Biphenyls / naphthalenes < 0.20 - (7)
(Ar ₁ is a content of a compound containing one aromatic ring with respect to the total amount of the raw materials, Ar ₂ is a content of a compound containing two aromatic rings with respect to the total amount of the raw materials, and Ar ₃ includes three aromatic rings with respect to the total amount of the raw materials Naphthalenes and biphenyls are contents relative to the total amount of the raw materials, and biphenyls / naphthalenes are contents of the total amount of the raw materials.

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