KR20150118432A - Optical anisotropic pitches from residual fuel oil, method for preparing the same, and pitch carbon fibers using the same - Google Patents

Abstract

The present invention relates to an optical anisotropic pitch and carbon fiber using the pitch as a precursor and, more specifically, to a remaining oil-derived optical anisotropic pitch, which is produced by directly using, as a raw material, petroleum-based remaining oil produced after a petroleum refining process, and has characteristics adequate to manufacture carbon fiber and activated carbon fiber. In addition, the present invention also relates to a method for producing the pitch, and pitch carbon fiber produced by the pitch.

Description

[TECHNICAL FIELD] The present invention relates to an optical anisotropic pitch derived from a residue, a method for manufacturing the pitch, and a pitch carbon fiber produced using the pitch. The optical anisotropic pitches from residual fuel oil,

The present invention relates to an optical anisotropic pitch and a carbon fiber using the pitch as a precursor. More specifically, the present invention relates to a method for producing a carbon fiber and an activated carbon fiber, An optical anisotropic pitch derived from the residual material having suitable characteristics, a method for manufacturing the pitch, and a pitch carbon fiber made with the pitch.

According to a report by the Oil & Gas Journal Data Book (Jan. 1, 2011), world oil production is 83,576,000 B / D and production is increasing every year. The increase in the indiscriminate use of these fossil fuels leads to an increase in greenhouse gas emissions and is a cause of climate change. The amount of byproducts of petroleum residues differs according to the refining method. The amount of residual oil is reduced by advanced technique, namely catalytic cracking, which is a chemical decomposition method, but the characteristic of residues produced there is a large molecular weight and a large carbon content. For example, the carbon content of a fluid catalytic cracking decant oil (FCC-DO) is about 90% (see Table 1). When it is burned and becomes CO ₂ , its mass becomes 12 to 44, 3.7 times. Therefore, it is advantageous to use these residues as a carbon material which can use carbon effectively, rather than as a fuel.

The types of pitches are generally classified into petroleum and coal-based types, and their average molecular characteristics are different. Since the petroleum pitch (Fig. 1 (a)) is larger than that of the coal pitch (Fig. 1 (b)) and has a large molecular size and aliphatic content, the radical reaction occurs rapidly by heat treatment. Rather than forming an isotropic coke. On the other hand, the coal tar pitch has a relatively small molecular weight and a small content of aliphatic groups, which easily forms an anisotropic phase by heat treatment. On the other hand, there is a considerable amount of hetero elements and impurities such as S, N, etc. in the coal system, which results in popping due to high temperature heat treatment, which is a problem in producing high quality materials and is disadvantageous in the process.

Among the petroleum pitches, Pyrolyzed Fuel Oil (PFO) from Naphtha cracking bottom (NCB) is linked with the aliphatic group in the 2-4 ring aromatic group so that it is a chain in the longitudinal direction and can synthesize isotropic pitch rather than anisotropy. (Byung-Jun Kim, Kap Seung Yang, Seong-Ho Yoon, Current Organic Chemistry, 2013, 17, 1463-1468)

In general, pitch is an amorphous structure and exhibits optically isotropic characteristics. When the amorphous pitch is heated to a temperature of about 350 DEG C or higher in an inert gas, the molecules of the pitch are oriented and a kind of liquid crystal optically arranged in the pitch is produced. These liquid crystals are called anisotropic or mesophase beads. The anisotropic sphere generated in this way grows into a large domain by gradually integrating with the heat treatment time. The carbon fiber produced with the anisotropic pitch thus produced is advantageous in that it has better mechanical or electrical properties than the carbon fiber produced at an isotropic pitch.

The anisotropic pitch molecules are formed from lamination such that the free energy is lowered at a temperature at which an aromatic ring having a plate-like structure can impart fluidity. Therefore, when the molecular weight suddenly increases due to condensation or radical reaction, isotropic coke is produced instead of anisotropic phase. For this reason, the anisotropic pitch precursor has a plate-like structure and exhibits fluidity below the reaction temperature to form an anisotropic phase and is excellent in radioactivity, so that it is suitable for producing carbon fibers. In addition, the radiated precursor fibers should have a sufficiently high softening point so that oxidation stability can be achieved at a high speed.

On the other hand, petroleum residues are by-products from refining processes. In the case of FCC-DO, FCC-DO refers to a by-product that is produced by the fluid catalytic cracking process using vacuum gas oil produced in the refinery process, such as LPG, gasoline, light oil, etc., as shown in FIG.

FIG. 3 shows the results of analysis of the molecular weight distribution of the used FCC-DO. As a result, it can be confirmed that various kinds of molecules ranging from about 200 to 800 Dalton are mixed in FCC-DO and molecules of 200 to 400 Dalton are mainly present. Table 1 shows the results of FCC-DO elemental analysis and orientation measurements.

sample Elemental analysis Orientation N C H S O C / H mol% FCC-DO 0 89.69 7.87 0 0.23 0.95 0.673

As a method for producing pitch, pitch oil having a certain structure and molecular weight is extracted from petroleum residue or coal tar by solvent extraction and then heat-treated. Extraction requires a large amount of solvent, which requires additional expense, which is more than half the total cost of the carbon material manufacturing process except for the carbonization process, which has been a major factor in increasing the cost of production products.

In order to solve these problems, Mitsubishi Gas Co., Ltd. has developed a process for extracting desired pitch oil from a complicated and heavy process residue by using pure compound materials (for example, naphthalene, methylnaphthalene, anthracene, etc.) To produce a precursor for a carbon material having comparatively uniform physical properties. However, the cost of the raw material is higher than that of the conventional method, and the HF / BF3, which is a super strong acid, is used to provide additional equipment for process safety reasons. Mochida, K. Shimizu, Y. Korai, H. Otsuka, Y. Sakai and S. Fujiyama, Carbon, 28, 311 (1990)].

In addition, there is a method for producing carbon fibers containing nitrogen by polycondensation of quinoline (isoquinoline) to prepare pitches, and using the pitch to prepare carbon fibers, This is expensive and difficult to recover and to remove AlCl ₃ used to make the pitch, which has limitations in commercial value [I. Mochida, KHEN and Y. Korai, Carbon, 33, 1069-1079 (1995)].

 There is a method of hydrogenating a raw material using a zeolite doped with platinum as a method of hydrogenating a raw material, but this method further requires a step of recovering and removing the used zeolite after hydrogenating the raw material [P. Arias, J. F. Cambra, B. G ㆌemez, V.L. Barrio, R. Navarro, B. Pawelec, J. L.G. Fierro, Fuel Processing Technology, 64, 17-133 (2000)] [Jian Zheng, Ming Guo, Chunshan Song, Fuel Processing Technology, 89, 467-474 (2008)].

Therefore, there is a growing need for a technique capable of manufacturing an optically anisotropic pitch by a simpler method.

The present inventors have completed the present invention by developing a technique capable of producing an optically anisotropic pitch having properties that can be used as a precursor of high-performance carbon fibers and activated carbon fibers as a raw material directly from petroleum residues.

Therefore, it is an object of the present invention to provide a process for producing an optical fiber having an optical anisotropic pitch derived from a residual material having suitable characteristics as a precursor such as high-performance carbon fiber and activated carbon fiber without using a petroleum residue as a raw material, And a method for manufacturing the same.

Another object of the present invention is to provide a method of manufacturing a pitch capable of controlling the characteristics of optically anisotropic pitch by controlling process conditions as well as being excellent in radioactivity.

It is still another object of the present invention to provide pitch carbon fibers and graphitized fibers produced with optical anisotropic pitches derived from the residue.

The object of the present invention is not limited to the above-mentioned objects, and although not explicitly mentioned, the object of the invention which can be recognized by a person skilled in the art from the description of the detailed description of the invention .

In order to achieve the object of the present invention described above, the present invention provides an optical anisotropic pitch characterized in that the petroleum residue is hydrogenated and MALDI-TOF molecular weight is 300 to 1000.

In a preferred embodiment, the pitch has a C / H molar ratio of 1.5 to 2.0.

In a preferred embodiment, the optically anisotropic pitch is spinnable at a spinning speed of 150 to 300 m / min upon spinning with a spinner.

In a preferred embodiment, the pitch has a softening point of 265 to 320 ° C.

The present invention also relates to a method of manufacturing a petroleum residue, comprising: a pretreatment step of removing a low boiling point material of a petroleum residue; A hydrogenation step of hydrogenating the pretreated residual oil; And a heat treatment step of heat-treating the hydrogenated residual oil.

In a preferred embodiment, the pretreatment step is carried out by treating under vacuum at 100 to 250 ° C for 2 to 8 hours.

In a preferred embodiment, the hydrogenation step is performed by mixing the hydrogen donor with the residual oil from which the low boiling point material has been removed, followed by pressurized heat treatment.

In a preferred embodiment, the hydrogen donor is selected from the group consisting of terrahydronaphthalene (1,2,3,4-Tetralin), 9,10-dihydroanthransene (9,10-DHN) Tetrahydroquinoline < / RTI > (1,2,3,4-tetrahydroquinoline).

In a preferred embodiment, the petroleum residue is PFO or FCC-DO.

In a preferred embodiment, the heat treatment step comprises: a first heat treatment step in which the pitch precursor material is heat treated at a nitrogen flow rate of 400 to 420 DEG C for 4 to 10 hours to form a pitch precursor material; cooling the pitch precursor material; And a second heat treatment step of heat-treating the material at 380 to 400 ° C for 5 to 10 hours.

In a preferred embodiment, controlling the characteristics of the optically anisotropic pitch produced by controlling at least one of temperature and time and nitrogen flow conditions for performing the primary heat treatment step and the secondary heat treatment step.

The present invention also relates to a method for producing pitch emission fibers, comprising the steps of: spinning any one of the optically anisotropic pitches described above or the optically anisotropic pitches produced by either method to form pitch-emitting fibers; Oxidizing and stabilizing the pitch-emitting fibers to produce an incompatible fiber; And a carbonization step of carbonizing the infusible fiber to produce a carbon fiber.

In a preferred embodiment, the oxidative stabilization step treats the spinning fiber at 280-320 < 0 > C in air.

In a preferred embodiment, the carbonization step treats the infusible fiber at 700 to 1500 占 폚.

The present invention also provides a pitch carbon fiber produced by the above-described production method and comprising an optically anisotropic pitch structure.

The present invention also provides pitch graphitized fibers obtained by graphitizing pitch carbon fibers and comprising an optically anisotropic pitch structure.

The present invention has the following excellent effects.

First, according to the present invention, an optical anisotropic pitch derived from a residue having suitable characteristics as precursors such as high-performance carbon fibers and activated carbon fibers, without using a solvent-extraction residue and a catalyst removal process, Method can be provided.

In addition, according to the present invention, not only the radioactivity is excellent but also the characteristics of the optical anisotropic pitch can be controlled by adjusting the process conditions.

Further, according to the present invention, it is possible to provide pitch carbon fibers and graphitized fibers produced with an optical anisotropic pitch derived from residual oil.

These technical advantages of the present invention are not limited to the above-mentioned technical scope, and even if not explicitly mentioned, the effect of the invention which can be recognized by a person skilled in the art from the description of the concrete contents for carrying out the invention Of course.

1 (a) shows the average molecular structure of the petroleum pitch and (b) shows the average molecular structure of the coal-based pitch.
2 is an example of a manufacturing process of FCC-DO which is a petroleum residue.
Fig. 3 is a graph showing the results of molecular weight distribution analysis (MALDI-TOF) of FCC-DO.
Figure 4 is a schematic process diagram for manufacturing an anisotropic pitch using petroleum residue according to embodiments of the present invention.
FIG. 5 is a graph of MALDI-TOF molecular weight distribution analysis results of a substance (VR) produced by pretreatment of FCC-DO according to embodiments of the present invention.
6 is a graph showing changes in softening point according to nitrogen flow rate conditions according to embodiments of the present invention.
FIG. 7 is a graph of MALDI-TOF molecular weight distribution analysis results of pitches produced by hydrogenation according to embodiments of the present invention and pitches produced without hydrogenation. FIG.
8 is a polarized microscope photograph of each pitch produced according to hydrogenation and nitrogen flow conditions according to embodiments of the present invention.
(a): heat treatment (b): THN addition heat treatment 600 mL / min (c) THN addition heat treatment 1000 mL / min
9 (a) is a photograph of a spinning fiber with a pitch produced without hydrogenation, and (b) is a spinning fiber photograph of a pitch produced by hydrogenation according to embodiments of the present invention.
10 is a graph showing tensile strength characteristics of carbon fibers produced by using pitch as a precursor according to an embodiment of the present invention.
FIG. 11 (a) is a graph of XRD analysis of carbon fibers prepared using pitch as a precursor according to an embodiment of the present invention, and FIG. 11 (b) is a graph of Raman spectroscopy analysis result.
12 (a) is a scanning electron microscope (SEM) photograph of a carbon fiber fabricated at a pitch according to an embodiment of the present invention, and FIG. 12 (b) It is a scanning electron microscope (SEM) photograph of a fiber.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Accordingly, the terms used in the present invention should not be construed to be mere terms, but should be interpreted based on the ordinary meanings of the terms and contents described throughout the specification of the present invention.

Hereinafter, the technical structure of the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

The technical feature of the present invention is that the optical anisotropic pitch derived from the residue having suitable properties as a precursor such as high-performance carbon fiber, activated carbon fiber and the like, without using solvent extraction and catalyst removal process while using petroleum residue as a raw material, Which is a method developed.

Therefore, the optically anisotropic pitch of the present invention is obtained by hydrogenating petroleum residues and has a MALDI-TOF molecular weight of 300 to 1000.

In addition, the optical anisotropic pitch of the present invention has a C / H molar ratio of 1.5 to 2.0, a softening point of 265 to 320 ° C and a very good spinnability. For example, a spinning speed of 150 to 300 m / min Radioactive. Due to these properties, the optically anisotropic pitch of the present invention can be used as a precursor material for carbon fibers because it can form spinning fibers without being spun well during spinning.

In addition, the method of manufacturing an optically anisotropic pitch of the present invention includes a pretreatment step of removing a low boiling point material of a petroleum residue; A hydrogenation step of hydrogenating the pretreated residual oil; And a heat treatment step of heat-treating the hydrogenated residual oil. Here, the petroleum residues may be all petroleum residues of known species, for example PFO or FCC-DO.

The pretreatment step is a step for removing low boiling matter contained in petroleum residues. Any known method may be used, but may be carried out, for example, by treating at 100 to 250 ° C under vacuum for 2 to 8 hours. As a result, the degree of orientation and C / H mol% are increased as compared to the residual oil not subjected to the pretreatment step.

The hydrogenation step is carried out by mixing the hydrogen donor with the residual oil from which the low-boiling point material has been removed, followed by a pressure heat treatment. For example, 5-10 parts by weight hydrogen donor is mixed per 100 parts by weight of the raw material (VR) The pressure in the reactor is increased to 10-15 bar by using nitrogen, the temperature is raised to 300 ° C to 350 ° C at 5 ° C per minute, and the heat treatment is performed for 30 minutes to 90 minutes.

At this time, the hydrogen donor may be any known material suitable for carrying out the hydrogenation step described above, for example, terahydronaphthalene (1,2,3,4-Tetralin), 9,10-dihydroanthran Sen (9,10-DHN), 1,2,3,4-tetrahydroquinoline, or 1,2,3,4-tetrahydroquinoline.

 The heat treatment step may be performed including a first heat treatment step, a cooling step and a second heat treatment step. The first heat treatment step is to form a pitch precursor material by inducing a condensation polymerization reaction. The first heat treatment step may be performed at 400 to 420 ° C under a nitrogen flow rate condition for 3 to 10 hours, and the nitrogen flow rate condition may range from 500 to 1100 ml / min . The cooling step is to enhance the anisotropy of the formed pitch precursor material through the second heat treatment by treating the formed pitch precursor material at a first heat treatment temperature to a room temperature at a nitrogen flow rate for 4 to 6 hours. The second heat treatment step is performed by heat treating the cooled pitch precursor material at 380 to 400 占 폚 for 5 to 12 hours.

The molecular weight, softening point, C / H molar ratio, and radioactivity of the optical anisotropic pitch produced by controlling at least one of the first heat treatment and the second heat treatment temperature and the nitrogen flow condition in the above-mentioned heat treatment step can be controlled.

In addition, the method of producing pitch carbon fibers of the present invention is characterized by using an optically anisotropic pitch having the above-described characteristics or an optically anisotropic pitch produced by the above-described production method as a carbon fiber precursor material, And a carbonization step.

The spinning step is the step of melt-spinning the optically anisotropic pitch of the present invention to form pitch spinning fibers, for example using a single-hole spinneret spinning at a temperature above the softening point of the optically anisotropic pitch described above, 150 to 300 m / min.

The oxidative stabilization step may be performed by preparing an incompatible fiber by oxidizing and stabilizing the fiber at a temperature of from room temperature to 280 ° C to 320 ° C at a temperature of 1 ° C per minute for 30 to 90 minutes.

The carbonization step is a step of carbonizing the infusible fiber to produce carbon fiber. The infusibilized fiber is heated from 700 to 1500 占 폚 at room temperature to 5 占 폚 / minute and carbonized for 30 minutes to 90 minutes.

The pitch carbon fiber of the present invention includes an optically anisotropic pitch structure, and has a tensile strength of 888.7 MPa or more and a tensile rigidity of 90.6 GPa or more.

By graphitizing the pitch carbon fibers of the present invention, pitch graphitized fibers containing an optically anisotropic pitch structure can be obtained.

Example 1

As shown in Fig. 4, the optically anisotropic pitch can be produced after hydrogenating the petroleum residue. More specifically, it is as follows.

1. Pre-processing step

First, 200 g of petroleum residue (FCC-DO) was charged into a 500 ml reactor, stirred at 300 rpm, and the low-boiling substance was removed under vacuum at 150 ° C for 4 hours.

2. Hydrogenation step

10 g of Tetrahydronaphthalene (THN) was mixed with 100 g of the raw material (VR) from which the low boiling point material was removed, and the resulting mixture was charged into a pressurized reactor. The inside pressure of the reactor was raised to 9.8 bar using nitrogen, The temperature was raised to 5 [deg.] C / min and the hydrogenation step was carried out by heat treatment for 1 hour.

3. Heat treatment step

100 g of the hydrogenated residual oil (VR-THN) was placed in a 500 ml reactor, and the temperature was raised from room temperature to 400 ° C at a rate of nitrogen flow rate of 600 ml / min at a normal pressure to 5 ° C per minute and subjected to a first heat treatment for 4 hours, . The pitch precursor material was then cooled for 4 hours to room temperature while maintaining a nitrogen flow rate. Next, the cooled pitch precursor was heated to 380 캜 and subjected to an additional secondary heat treatment for 8 hours to prepare an optical anisotropic pitch 1 [VR-THN * 400 (240) 380 (480) 600 ml / min].

Example 2

The optical anisotropic pitch 2 [VR-THN * 400 (240) 380 (480) 800 ml / min] was prepared in the same manner as in Example 1 except that the nitrogen flow rate was changed to 800 ml / min.

Example 3

The optical anisotropic pitch 3 [VR-THN * 400 (240) 380 (480) 1000 ml / min] was prepared in the same manner as in Example 1 except that the nitrogen flow rate was changed to 1000 ml / min.

Comparative Example 1

200 g of petroleum residue (FCC-DO), which had not undergone the pretreatment step, was charged into a 500 ml reactor and stirred at 300 rpm. The temperature was raised from room temperature to 400 ° C at a nitrogen flow rate of 600 ml / And a heat treatment was performed for 6 hours to prepare a comparative example pitch 1 [FD 400 (300) 600 ml / min].

Comparative Example 2

(Comparative Example 2) [VR * 400 (240) 400 (360) 600 ml / min] was obtained in the same manner as in Example 1, except that the hydrogenation step was not performed and the second heat treatment was performed at 400 ° C for 6 hours.

Experimental Example 1

The various characteristics of the pitches obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were analyzed, and the results are shown in Table 2.

Sample type yield
(wt%) Softening point
() Elemental analysis Orientation
Degree N C H S O C / H mol% FCC-DO - - 0 89.69 7.87 0 0.23 0.95 0.653 VR - - 0.442 90.983 7.694 0.232 0.577 0.99 0.686 VR-THN - - 0.12 88.94 7.87 0 0.11 0.94 - Comparative Example 1 FD 400 (300)
600ml / min 86.5 Liquid Comparative Example 2 VR * 400 (240) 400 (360) 600 ml / min 33.1 293.2 0 95.48 4.46 0 0.06 1.79 - Example 1 VR-THN
400 (240) 380 (480) 600 ml / min 15.2 317.9 0 95.52 4.41 0 0.07 1.81 - Example 2 VR-THN
400 (240) 380 (480) 800 ml / min 16.5 293.1 0.41 95.15 4.25 0 0.19 1.87 - Example 3 VR-THN
400 (240) 380 (480) 1000 ml / min 13.2 278.5 0.41 94.74 4.68 0 0.18 1.69 -

First, in the case of Comparative Example 1, only the FCC-DO itself was subjected to the heat treatment for 6 hours at 400 ° C. However, as shown in Table 2, the result was confirmed to be a liquid phase like the FCC-DO used for the first time. It can be seen that a preprocessing step is essential for producing pitch.

In addition, when the low boiling point material was removed from the FCC-DO, the degree of orientation and the C / H mol% were increased as seen from Examples 1 to 3 and Comparative Example 2. On the other hand, it can be seen that the C / H mol% decreases again after the hydrogenation, which is predicted by the increase of the hydrogen content after the heat treatment under pressure. In addition, as compared with the results of Example 1, it was found that the yield and C / H ratio decreased and the softening point decreased when the flow rate of nitrogen was increased as in Example 2 and Example 3, .

Experimental Example 2

The molecular weights of the molecules constituting the petroleum residue (FCC-DO) and the residual oil (VR) from which the low-boiling substance was removed were analyzed and the results are shown in FIG.

From FIG. 5, it can be seen that the ratio of molecules having molecular weights of 600 Dalton or more to VR is increased compared to FCC-DO. This is because the volatile substance, which is a low molecular substance, is removed, The distribution seems to be growing.

Experimental Example 3

Experiments were carried out using the Soxhlet extractor to determine the optical anisotropic pitches 1 to 3 and the solubility of the used samples obtained in Examples 1 to 3. The results are shown in Table 3.

Sample Solubility (%) BS BI-TS TI-THFS THFI FCC-DO 100.0 - - - VR 100.0 - - - VR-THN
400 (240) 380 (480)
600ml / min 11.7 8.9 13.1 66.3 VR-THN
400 (240) 380 (480)
800ml / min 16.8 15.3 7.4 60.5 VR-THN
400 (240) 380 (480)
1000ml / min 7.9 21.5 19.8 50.8 * BS-benzene soluble; BI-TS benzene insoluble and toluene soluble; TI-THFS - toluene insoluble and THF soluble; THFI THF insoluble

The sample FCC-DO and the VR from which the low boiling point material was removed were 100% dissolved in benzene, but in the case of synthesized optical anisotropic pitch 1 to 3, about 11.7%, 16.8%, and 7.8 %, Respectively, and those which were not soluble in THF were 66.3%, 60.5% and 50.8%, respectively.

Experimental Example 4

The softening point of the optical anisotropic pitch 1 to 3 prepared in Examples 1 to 3 was measured at 380 캜 according to the additional heat treatment time, and the results are shown in Fig.

6, when the nitrogen flow rate is 1000 ml / min, the initial softening point is higher than the other flow conditions, but as the heat treatment time is increased, the softening point of the pitch generated at a nitrogen flow rate of 600 ml / min is higher Respectively. When the initial nitrogen flow rate is high, the low molecular weight material is rapidly removed and the softening point is measured to be high. However, it is predicted that the low molecular weight material is formed in the production of the polymer material.

Experimental Example 5

The molecular weight distributions of the optical anisotropic pitch 1 obtained in Example 1 and the comparative example 2 obtained in Comparative Example 2 were analyzed and the results are shown in Fig.

7, in the case of VR 400 (240) 400 (360), which is a pitch synthesized without processing with THN as in Comparative Example 2, a lot of molecules corresponding to 200 to 400 Dalton were measured, In the case of VR-THN 400 (240) 380 (480), which is an optical anisotropic pitch of the present invention, it is understood that molecules having less than 300 Dalton are almost eliminated and molecules having 300 to 600 Dalton are measured.

Experimental Example 6

The structure of the pitches obtained in Comparative Example 2 and Examples 1 and 3 was observed, and the results are shown in Fig.

FIG. 8 (a) is a photograph of the optical structure of Comparative Example 2 obtained in Comparative Example 2, wherein anisotropic regions are observed after the additional heat treatment, but a large number of optically isotropic regions exist. From the photographs (b) and (c) shown in the photographs of the optical structures of the additional heat treatment time periods of Example 1 and Example 3, it was confirmed that the anisotropic region expanded in the case of Example 1 because the additional heat treatment time was increased at 380 ° C, In the case of Example 3, it was confirmed that the generated anisotropic region did not increase to a large domain but increased only to a small region as the annealing time increased. It is predicted that anisotropic nuclei are produced by removing low molecular substances but they do not form large domains due to lack of fluidity. This phenomenon seems to be favorable for the expansion of the anisotropic phase because the molecules having a large molecular weight and a flat structure have a large molecular weight but a high fluidity.

Therefore, the anisotropic pitch having excellent radioactivity is advantageously used when growing into a large domain by gradually integrating with anisotropy, and when the molecular weight suddenly becomes large, it becomes difficult to form an expanded anisotropic phase due to a non-uniform phase, thereby locally forming beads, Element.

Example 4

A pitch carbon fiber was prepared as follows using the optical anisotropic pitch 1 obtained in Example 1 as a carbon fiber precursor.

1. Radiation step

The optically anisotropic pitch 1 was melted and spinning was carried out using a single hole emitter to obtain pitch spinning fibers. At this time, the spinning was carried out at a spinning temperature of 360 캜 and a winding speed of 150 m / min.

2. Oxidation Stabilization Step

The pitch spinning fiber was heated from room temperature to 300 캜 at a rate of 1 캜 per minute and oxidized and stabilized for 1 hour to obtain an infusible fiber.

3. Carbonization step

Carbonization was carried out by heating the infusibilized fiber from room temperature to 800 ° C at a rate of 5 ° C per minute and carbonizing for 1 hour to obtain pitch carbon fiber 1.

Example 5

The pitch carbon fiber 2 was obtained in the same manner as in Example 4, except that the spinning temperature was 370 ° C and the winding speed was 300 m / min.

Example 6

The pitch carbon fiber 3 was obtained in the same manner as in Example 4, except that the spinning temperature was 370 캜, the winding speed was 300 m / min, and the carbonization temperature was 1000 캜.

Comparative Example 3

A comparative example pitch carbon fiber was obtained in the same manner as in Example 4 except that the carbon fiber precursor was used as the comparative example 2 obtained in Comparative Example 2. [

Experimental Example 7

The comparative example pitch spinning fiber obtained in Comparative Example 3 and the pitch spinning fiber obtained in Example 4 were observed and the resulting photographs are shown in Figs. 9 (a) and 9 (b), respectively.

In Comparative Example 3 and Example 4, the softening point of the pitch used as the carbon precursor was measured at about 300 ° C., but when irradiated with the fiber, as shown in FIG. 10, the optical anisotropy pitch 1 of Example 4, The comparative example pitch 2 of Comparative Example 3, that is, the VR 400 (240) 400 (360) which is a non-hydrogenated sample, was spin- It was confirmed that the fibers could not be made by taking up the single yarn because of the poor radioactivity.

Experimental Example 8

Table 4 shows the diameters, the fusing yields, and the carbonization yields of the fibers according to the spinning conditions in the process of producing the pitch carbon fibers as in Examples 4 to 6, according to the following formula.

Radiation condition Radial fiber diameter (탆) Carbon fiber diameter (탆) Disproportionation yield (%) Carbonization yield (%) 150 m / min-800 DEG C 47.0 to 52.0 46.4 to 50.9 103.35 88.57 300m / min-800C 22.0 to 33.0 20.2 to 31.2 107.38 88.60 300 m / min-1000 < 0 > C 22.0 to 33.0 13.5 to 30.2 107.38 86.15

(% By weight) = sample mass after immobilization / sample mass after immobilization ㅧ 100

Carbonization yield (% by weight) = mass of sample after carbonization / sample mass before carbonization 100

From Table 4, it can be seen that the diameter of the carbon fibers as well as the diameter of the radial fibers can be controlled according to the spinning conditions and the carbonization conditions.

Experimental Example 9

The tensile strength characteristics of the pitch carbon fiber 2 prepared in Example 5 were analyzed and the results are shown in FIG.

10, it can be seen that the produced pitch carbon fiber 2 exhibits a tensile strength of 888.7 MPa and a tensile rigidity of 90.6 GPa, which is expected to be higher when the diameter is controlled.

Experimental Example 10

XRD analysis and raman spectroscopy analysis were performed on the pitch carbon fiber 2 prepared in Example 5, and the results are shown in FIG.

From Fig. 11, it can be seen from the XRD analysis that 2theta peak was observed at 25.34 피 for the pitch carbon fiber, and the interlayer spacing was 3.5101 Å, where FWHM was 0.031. Further, Raman spectroscopy analysis was the D band is measured at 1329.3cm ^-1, the G band was measured in the 1602.0cm ^-1, it has been identified as the 1.059 relative _{intensity (R = I D / I} G).

Example 7

The pitch carbon fiber 2 produced in Example 5 was graphitized at 2800 DEG C for 30 minutes to obtain pitch graphitized fibers.

Experimental Example 11

Sections of the pitch carbon fibers 2 produced in Example 5 and the cross-section of the pitch graphitized fibers prepared in Example 7 were analyzed using SEM, and the results are shown in FIG.

It can be seen from Fig. 12 that the radial structure of the anisotropic pitch fiber structure appears in the graphitized graphite fibers after the graphitization.

The above experimental results show that the optical anisotropic pitch according to the present invention not only has properties of a carbon precursor which is effective for producing graphite fibers as well as carbon fibers but also exhibits excellent properties without a process relating to solvents and catalysts, Lt; RTI ID = 0.0 > anisotropic < / RTI > Accordingly, the present invention can provide a precursor material capable of producing a carbonaceous product having a high added value at a low cost by utilizing the petroleum stover.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (16)

An optical anisotropic pitch obtained by hydrogenating a petroleum residue and having a MALDI-TOF molecular weight of 300 to 1000.
The method according to claim 1,
Wherein the pitch is a C / H molar ratio of 1.5 to 2.0.
The method according to claim 1,
An optical anisotropic pitch having a spinnability capable of winding at a spinning speed of 150 to 300 m / min when spinning the optically anisotropic pitch with a spinner.
The method according to claim 1,
Wherein the pitch is a softening point of 265 to 320 ° C.

A pretreatment step of removing a low boiling point material of petroleum residue;
A hydrogenation step of hydrogenating the pretreated residual oil; And
And a heat treatment step of heat-treating the hydrogenated residual oil.
6. The method of claim 5,
Wherein the pretreatment step is performed by treating at 100 to 250 ° C under vacuum for 2 to 8 hours.
6. The method of claim 5,
Wherein the hydrogenation step is performed by mixing the hydrogen donor with the residual oil from which the low-boiling point material has been removed, followed by a pressure heat treatment.
8. The method of claim 7,
The hydrogen donor is selected from the group consisting of terahydronaphthalene (1,2,3,4-Tetralin), 9,10-dihydroanthransene (9,10-DHN), 1,2,3,4-tetrahydroquinoline , 2,3,4-tetrahydroquinoline). ≪ / RTI >
6. The method of claim 5,
Wherein the petroleum residue is PFO or FCC-DO.
6. The method of claim 5,
The heat treatment step may include a first heat treatment step of forming a pitch precursor material by heat treatment at 400 to 420 ° C under a nitrogen flow rate condition for 4 to 10 hours, cooling the pitch precursor material, and cooling the cooled pitch precursor material to 380 to 400 ° C And a second heat treatment step of performing a heat treatment for 5 to 10 hours in the second heat treatment step.
11. The method of claim 10,
Wherein the characteristic of the optically anisotropic pitch is controlled by controlling at least one of a temperature and a time and a nitrogen flow rate condition for performing the first heat treatment step and the second heat treatment step.
A spinning step of melt spinning the optically anisotropic pitch of any one of claims 1 to 4 or the optically anisotropic pitch produced by the method of any one of claims 5 to 11 to form pitch spinning fibers;
Oxidizing and stabilizing the pitch-emitting fibers to produce an incompatible fiber; And
And carbonizing the infusible fiber to produce a carbon fiber.
13. The method of claim 12,
Wherein the oxidative stabilization step comprises treating the spinning fiber at 280 to 320 DEG C in the air.
13. The method of claim 12,
Wherein the carbonization step comprises treating the infusible fiber at 700 to 1500 占 폚.
A pitch carbon fiber produced by the manufacturing method of claim 12 and comprising an optically anisotropic pitch structure.
A pitch graphitized fiber obtained by graphitizing the pitch carbon fiber of claim 15 and comprising an optically anisotropic pitch structure.

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