CN110157476B

CN110157476B - Method for manufacturing mesophase pitch for high-thermal-conductivity carbon fibers

Info

Publication number: CN110157476B
Application number: CN201910510771.8A
Authority: CN
Inventors: 刘辉
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-04-28
Anticipated expiration: 2039-06-13
Also published as: CN110157476A

Abstract

The invention relates to a method for manufacturing mesophase pitch for high-thermal-conductivity carbon fibers, which comprises the following steps of: (1) mixing the purified residual oil with HF gas, stirring and reacting to obtain an HFMP intermediate; (2) reacting the HFMP intermediate for 2-5 hours under the conditions of 2800-3200 Pa and 350-450 ℃, and cooling to prepare HFMP; the invention discloses a process for preparing mesophase pitch for high-thermal-conductivity carbon fibers by introducing HF (hydrogen fluoride) serving as a catalyst into residual oil for reaction for the first time. Due to the directional catalytic action of HF, the system is always carried out in an attomoto condensation mode in the process of polycondensation of small molecules into macromolecules, and the large-plane molecular structure of the mesophase asphalt is ensured. Meanwhile, due to the catalytic action of HF, the reaction time is shortened, the reaction can be carried out under normal pressure, the requirement on the pressure resistance of equipment is low, the equipment cost is saved, and the prepared mesophase pitch meets the requirement on preparing the high-heat-conductivity carbon fiber.

Description

Method for manufacturing mesophase pitch for high-thermal-conductivity carbon fibers

Technical Field

The invention relates to a method for preparing mesophase pitch for high-thermal-conductivity carbon fibers, and belongs to the technical field of preparation of high-performance carbon fibers.

Background

Mesophase pitch, also called anisotropic pitch, is a series of chemical reactions such as bond breaking, dehydrogenation, polycondensation and the like between molecules when coal tar, petroleum residual oil or pure aromatic hydrocarbon compounds (naphthalene, anthracene) are subjected to heat treatment (liquid phase carbonization at 350-.

The high heat conductivity carbon fiber is a military and civil dual-purpose industrial material with unique performance, has the characteristics of super high heat conductivity, light weight, high strength, super high modulus, high electric conductivity, low thermal expansion coefficient and the like, is most suitable for space environment with large day and night temperature difference, can be used as a reinforcement to prepare various structural and functional composite materials with zero thermal expansion coefficient, and becomes an indispensable reinforcement for solving the problems of outer layer space structure and functional composite materials. The high-heat-conductivity carbon fiber is commercially produced abroad, and China is still in the stages of development and trial production. Due to the strong military application color, developed countries in the western countries such as the United states and the Japan set the developed countries as strategic materials to be regulated, and export to China is strictly forbidden.

The mesophase pitch is the only raw material for preparing the high-thermal-conductivity carbon fiber, and the structure-function integrated high-thermal-conductivity composite material for the aerospace industry can only meet the use requirement of the carbon fiber prepared by the mesophase pitch; however, at present, no enterprises for industrially producing mesophase pitch (hereinafter abbreviated as HFMP) for high thermal conductivity carbon fibers exist in China, because the production process of HFMP is very harsh, and the performance of mesophase pitch produced by a conventional method cannot meet the requirement for preparing high thermal conductivity carbon fibers.

Chinese patent document CN104152168A (application No. 201410394762.4) discloses a mesophase pitch raw material with excellent spinnability and a preparation method thereof, wherein a naphthalene compound is used as a raw material, and a polymerization reaction is carried out in the presence of hydrogen fluoride and boron trifluoride as catalysts, wherein the amount of hydrogen fluoride is 0.5 to 15 times the molar number of the raw material, and the amount of boron trifluoride is 0.2 to 1.0 times the molar number of the raw material; and (3) the polymerization reaction temperature is 250-300 ℃, after the polymerization reaction is finished, removing a catalyst HF-BF3, carrying out reduced pressure distillation on the obtained product at the temperature of 400 ℃ and under the pressure of less than 1KPa, and separating out a low-boiling-point product to obtain a mesophase pitch raw material product. The technology takes naphthalene compounds as raw materials to prepare the mesophase pitch raw materials, so that the raw material cost is high, and the thermal conductivity of the carbon fibers prepared from the raw materials still cannot meet the requirements of special fields.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for manufacturing mesophase pitch for high-thermal-conductivity carbon fibers; the method can solve the problems of low efficiency, high requirement on equipment compression resistance, low yield and low product performance of HFMP produced by the conventional method in China.

The technical scheme of the application is as follows:

a method for manufacturing mesophase pitch for high thermal conductive carbon fibers, comprising the steps of:

(1) mixing the purified residual oil with HF gas at the temperature of 325-400 ℃, stirring and reacting for 2-5 hours, wherein the introduction speed of the HF gas is 0.01-0.20 mol/min per kilogram of residual oil, and preparing an HFMP intermediate;

(2) reacting the HFMP intermediate prepared in the step (1) for 2-5 hours under the conditions of 2800-3200 Pa and 350-450 ℃, and cooling to prepare HFMP;

according to the present invention, in the step (1), the water content of the HF gas is preferably 0.

According to the invention, in the step (1), the density of the residual oil is 1.05-1.10 g/cm³Viscosity of 18-20 Pa.S, condensation point of 23.5-24.5 ℃, flash point of 215-225 ℃ and water contentThe ratio was 0.

Preferably, according to the invention, in step (1), the HF gas is introduced at a rate in the range of 0.05, 0.10, 0.15, 0.20mol/min or any range therebetween per kg of residue.

Preferably, in step (1), the reaction temperature is 330 ℃, 340 ℃, 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃ or a range between any two of them.

Preferably, in step (1), the reaction time is 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or a range between any two of them.

Preferably, in step (2), the reaction temperature is 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃ or a range between any two of them.

Preferably, in step (2), the reaction time is 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or a range between any two of them.

A preparation method of high-thermal-conductivity carbon fibers comprises the following steps:

(i) spinning the prepared HFMP at a drawing speed of 400-450 m/min to prepare a primary spun yarn;

(ii) subjecting the primary spun yarn prepared in the step (i) to primary spinning under the condition of 280-320 ℃ in air environment and with tension of 4.5-5.5 g/g, and carrying out oxidation treatment for 25-35 min, wherein the air supply is as follows: 22-28L/min; and then adding 4.5-5.5 g/g of oxidized fibers under tension in a nitrogen environment at 950-1050 ℃, carbonizing for 18-22 min, adding 9-11 g/g of carbonized fibers under tension in an argon environment at 2400-2600 ℃, and graphitizing for 8-12 min to obtain the high-thermal-conductivity carbon fiber.

Preferably according to the invention, in step (i), the drawing speed is 410, 415, 420, 425, 430, 435, 440 m/min or a range between any two.

Preferably, according to the present invention, in the step (ii), the oxidation treatment temperature is 290, 295, 300, 305, 310 ℃ or a range between any two of them.

Preferably, in step (ii), the oxidation treatment time is 26, 27, 28, 29, 30, 31, 32, 33, 34min or a range between any two of them.

Preferably, according to the present invention, in step (ii), the carbonization temperature is 960, 970, 980, 990, 1000, 1010, 1020, 1030, 1040 or a range between any two of them.

Preferably, according to the present invention, in the step (ii), the carbonization treatment time is 19, 20, 21 or a range between any two of them.

Preferably, according to the present invention, in the step (ii), the graphitization treatment temperature is 2420, 2440, 2460, 2480, 2500, 2520, 2540, 2560, 2580 or a range between any two.

Preferably, in step (ii), the graphitization treatment time is 10 min.

The process principle of the invention is as follows:

the reaction mainly comprises two stages, namely normal pressure catalysis and reduced pressure polycondensation;

the first stage of the reaction is normal pressure catalytic reaction, HF gas is introduced into the residual oil to be used as a catalyst for cationic polymerization of a high molecular compound, so that aromatic compounds in the petroleum residual oil are promoted to undergo cationic polymerization, and in the reaction process, heavy-ring aromatic hydrocarbon macromolecules contained in the petroleum residual oil are condensed to form larger aromatic hydrocarbon molecules, and the aromatic hydrocarbon molecules are orderly arranged and have certain orientation to form an anisotropic liquid crystal phase, namely mesophase pitch. The mesophase pitch catalyzed by HF has consistent polycyclic aromatic hydrocarbon macromolecular structure and certain orientation, is beneficial to the attomoto condensation reaction, and forms a molecular structure (aromatic hydrocarbon molecular structure for catalytic polycondensation) similar to the following formula I:

the molecular arrangement of the mesophase pitch formed by the compound is more orderly, and the compound is favorable for forming an ideal graphite structure in subsequent stages of spinning, carbonization, graphitization and the like and is used as a precursor of a high-heat-conduction material.

The second stage of the reaction is a reduced pressure polycondensation reaction, and the small molecular compounds and the compounds which do not form the intermediate phase generated in the first stage of the catalytic reaction are extracted through a negative pressure distillation reaction, so that the intermediate phase content of the product is improved, the softening point of the intermediate phase asphalt is controlled, and the intermediate phase asphalt suitable for spinning is prepared.

After the mesophase pitch is made into fibers through spinning, oxidation, carbonization and graphitization, the pitch is converted into fibers, various condensed ring aromatic hydrocarbon compounds contained in the mesophase pitch are arranged in the axial direction of the fibers according to a certain orientation, but the internal carbon atom distribution is in an aromatic ring distribution state, and is similar to an ideal graphite structure, so that the thermal performance of the fibers is not obviously improved. The inventor finds that orderly arranged polycyclic aromatic hydrocarbon macromolecules are introduced into asphalt molecules, so that spinning and graphitization heat treatment are facilitated.

In the carbonization stage, the carbon fiber prepared by HF catalyzed mesophase pitch has larger crystallite size, smaller interlayer spacing and high graphitization degree which respectively reaches 3.02, 3.3945A and 53.85 percent, compared with the carbon fiber prepared by HF catalyzed pitch with the graphitization degree of 23.37 percent at the lower temperature of 1600 ℃. The graphitization degree of the carbon fiber is further increased along with the increase of the treatment temperature. Through Raman tests, the skin-core factor of the carbon fiber of HF catalyzed mesophase pitch is 0.88, and the skin-core structure of the carbon fiber prepared by uncatalyzed mesophase pitch is 0.78, which shows that HF can effectively weaken the skin-core structure, improve the state of loose and disordered structures in the fiber, reduce the internal heterodynia of the fiber and contribute to the preparation of the carbon fiber with high thermal conductivity.

Advantageous effects

The invention discloses a process for preparing mesophase pitch for high-thermal-conductivity carbon fibers by introducing HF (hydrogen fluoride) serving as a catalyst into residual oil for reaction for the first time. Due to the directional catalytic action of HF, the system is always carried out in an attomoto condensation mode in the process of polycondensation of small molecules into macromolecules, and the large-plane molecular structure of the mesophase asphalt is ensured. Meanwhile, due to the catalytic action of HF, the reaction time is shortened, the reaction can be carried out under normal pressure, the requirement on the pressure resistance of equipment is low, the equipment cost is saved, and the prepared mesophase pitch meets the requirement on preparing the high-heat-conductivity carbon fiber.

Drawings

FIG. 1 is an electron microscope (SEM) image of an oxidized silk prepared in comparative example 1;

FIG. 2 is an electron microscope (SEM) image of oxidized silk prepared in example 1;

FIG. 3 is an electron microscope (SEM) image of the carbonized filament prepared in comparative example 1;

FIG. 4 is an electron microscope (SEM) image of a carbonized filament prepared in example 1;

FIG. 5 is a hot stage polarization microscope image of HFMP prepared in example 1;

FIG. 6 is a hot stage polarization microscope image of mesophase pitch prepared in comparative example 2;

Detailed Description

The technical solutions of the present invention are further described below with reference to the following embodiments and the accompanying drawings, but the scope of the present invention is not limited thereto.

Source of raw materials

HF gas is purchased from Shandong Xuchen chemical engineering Co., Ltd, and the purity is more than or equal to 99.99%;

the petroleum residual oil is common commercial residual oil, and the technical indexes are as follows: density: 1.09g/cm³Viscosity: 19Pa · S, moisture: none, condensation point: 24 ℃, flash point: at 220 ℃.

Example 1

(1) mixing the purified residual oil with HF gas at 400 ℃ and stirring for reaction for 5 hours, wherein the introduction speed of the HF gas is 0.05mol/min per kilogram of the residual oil, so as to prepare an HFMP intermediate;

(2) reacting the HFMP intermediate prepared in the step (1) for 5 hours at 3000Pa and 390 ℃, and cooling to prepare HFMP;

(i) spinning the prepared HFMP at the drawing speed of 400 m/min to prepare a primary spun yarn;

(ii) subjecting the primary spun yarn prepared in the step (i) to oxidation treatment for 30min under the air environment of 300 ℃ and with the tension of 5 g/g per gram of primary spun yarn, wherein the air supply is as follows: 25L/min, the product is shown in figure 2; and then adding 10 g/g of tension per gram of oxidized fiber in a nitrogen environment at 1000 ℃, carrying out carbonization treatment for 20min to obtain a product as shown in figure 4, adding 10 g/g of tension per gram of carbonized fiber in an argon environment at 2500 ℃, and carrying out graphitization treatment for 10min to obtain the high-thermal-conductivity carbon fiber.

The obtained carbon fiber is detected by a flash emission method heat conduction instrument LF467, the heat conductivity reaches 650W/m.K, is 41 percent higher than that of pure copper, is more than 2 times of that of the common mesophase pitch carbon fiber, and the mechanical property is slightly improved.

Example 2

(1) mixing the purified residual oil with HF gas at 325 deg.c, stirring and reacting for 2 hr, and introducing HF gas at 0.10mol/min per kg of residual oil to obtain HFMP intermediate;

(2) reacting the HFMP intermediate prepared in the step (1) for 2 hours at 2800Pa and 450 ℃, and cooling to prepare HFMP;

(i) spinning the prepared HFMP at the drawing speed of 450 m/min to prepare a primary spun yarn;

(ii) subjecting the primary spun yarn prepared in the step (i) to primary spinning under the condition of 280 ℃ in air, wherein the tension is 5.5 g/g, and the oxidation treatment is carried out for 25min, wherein the air supply is as follows: 28L/min; and then adding 11 g/g of oxidized fiber under tension in a nitrogen environment at 950 ℃, carbonizing for 22min, adding 11 g/g of carbonized fiber under tension in an argon environment at 2600 ℃, and graphitizing for 8min to obtain the high-thermal-conductivity carbon fiber.

The obtained fiber was measured by flash method thermal conductivity meter LF467 to obtain thermal conductivity 596W/m.K.

Example 3

(1) mixing the purified residual oil with HF gas at 380 deg.c and stirring to react for 4 hr, with HF gas being introduced at 0.15mol/min per kg of residual oil to obtain HFMP intermediate;

(2) reacting the HFMP intermediate prepared in the step (1) for 4 hours under the conditions of 3200Pa and 350 ℃, and cooling to prepare HFMP;

(ii) and (3) subjecting the primary spun yarn prepared in the step (i) to oxidation treatment for 35min under the air environment of 320 ℃ and with the tension of 4.5 g/g per gram of yarn, wherein the air supply is as follows: 22L/min; and then adding 9 g/g of tension per gram of yarn in a nitrogen environment at 1050 ℃, carrying out carbonization treatment for 18min, adding 9 g/g of tension per gram of carbonized yarn in an argon environment at 2400 ℃, and carrying out graphitization treatment for 12min to obtain the high-thermal-conductivity carbon fiber.

The obtained fiber was measured by a flash method thermal conductivity meter LF467, and the thermal conductivity was 575W/m.K.

Example 4

(1) mixing the purified residual oil with HF gas at 400 ℃ and stirring for reaction for 5 hours, wherein the introduction speed of the HF gas is 0.20mol/min per kilogram of the residual oil, so as to prepare an HFMP intermediate;

(2) reacting the HFMP intermediate prepared in the step (1) for 5 hours at 3000Pa and 400 ℃, and cooling to prepare HFMP;

(ii) and (3) subjecting the primary spun yarn prepared in the step (i) to oxidation treatment for 30min under the air environment at 300 ℃ and with the tension of 5.2 g/g per gram of yarn, wherein the air supply is as follows: 25L/min; and then adding 10.5 g/g of tension per gram of filament in a nitrogen environment at 1000 ℃, carrying out carbonization treatment for 25min, adding 9.5 g/g of tension per gram of carbonized filament in an argon environment at 2500 ℃, and carrying out graphitization treatment for 10min to obtain the high-thermal-conductivity carbon fiber.

The obtained fiber was measured by a scintillation thermal conductivity meter LF467, and the thermal conductivity was 568W/m.K.

Comparative example 1

The method for manufacturing mesophase pitch for carbon fibers having high thermal conductivity as set forth in example 1, except that the HF gas was replaced with nitrogen gas in an equal volume amount to prepare pitch.

The pitch obtained in the above procedure was processed into carbon fibers in the same manner as in example 1.

And (3) carrying out relevant detection on the obtained fiber, detecting by using a flash emission method heat conduction instrument LF467, and obtaining a detection result: the thermal conductivity of the fiber was 320W/m.K.

Comparative example 2

The method for producing mesophase pitch for carbon fibers having high thermal conductivity as described in example 1 is different in that the raw material is a naphthalene compound described in chinese patent document CN104152168A (application No. 201410394762.4) to produce pitch.

And (3) carrying out relevant detection on the obtained fiber, detecting by using a flash emission method heat conduction instrument LF467, and obtaining a detection result: the thermal conductivity of the fiber was 110W/m.K.

Examples of the experiments

The graphitization degrees of the carbon fibers prepared in example 1 and comparative examples 1-2 were respectively detected by using LF467 of german navy instruments, and their thermal conductivities were compared by the graphitization degrees; generally, the higher the graphitization degree of the graphite material, the better the heat conduction and electric conductivity. The tests in table 1 are all experimental data obtained after graphitizing for 10min under different temperature conditions:

TABLE 1 comparison of graphitization degree of mesophase pitch carbon fibers prepared by HF catalysis and conventional heat treatment

	1200℃	1300℃	1400℃	1500℃	1600℃
						Example 1	—	3.75	22.56	41.07	53.85
Comparative example 1	—	—	—	—	23.37
						Comparative example 2	—	—	—	3.97	28.78

As is apparent from table 1, the mesophase pitch carbon fiber prepared by the conventional heat treatment of comparative example 1 has substantially no graphite structure at 1600 degrees or less, the mesophase pitch prepared by the chinese patent document CN104152168A of comparative example 2 also starts to show the graphite structure only at 1500 degrees, while the mesophase pitch carbon fiber prepared by the HF catalysis of the residual oil generates the graphite structure at 1300 degrees, which is also 1600 degrees, and the graphitization degree of example 1 reaches 53.85%, which is much greater than that of the mesophase pitch carbon fiber prepared by the conventional heat treatment or the chinese patent document CN 104152168A. Thus, the HF catalyzed resid produced mesophase pitch can shift the internal molecular arrangement of the carbon fibers toward graphitization at lower temperatures.

The products obtained in example 1 and comparative examples 1-2 were observed by an electron microscope and a hot stage polarization microscope, respectively, and the results are shown in fig. 1 to 6.

The fibers of comparative example 1 and example 1 after oxidation and carbonization, respectively, were examined and the results are shown in fig. 1 to 2, the oxidized fiber of comparative example 1 (fig. 1) having a cross section with significantly higher porosity than the oxidized fiber of example 1 (fig. 2), which resulted in more porosity upon continued high temperature treatment (fig. 3), whereas (fig. 4) was made by HF catalysis with a cross section with significantly less porosity (fig. 3). The smaller the pores on the cross section of the fiber, the more regular the carbon layer structure in the fiber is, and the better the heat-conducting property of the fiber is.

Example 1 and comparative example 2 differ in the starting materials prepared. In the embodiment 1, petroleum residual oil is used as a raw material, and the catalyst is prepared by using a HF single catalyst, so that the prepared CFMP has a regular molecular structure and a controllable lamellar direction (see fig. 5, different benzene rings in asphalt molecules are in the same plane and are in a highly oriented structure, and the appearance under a microscope is in a streamline regular large lamellar structure), and the petroleum residual oil has the advantages of wide source, low price, less environmental pollution and easiness in recycling and reutilization. Comparative example 2 starting from pure naphthalene, HF and BF₃Preparing the composite catalyst. Due to the physicochemical properties of naphthalene, the molecular structure of the prepared CFMP is relatively disordered (see FIG. 6, benzene rings at different positions in the molecule are arranged irregularly, so that the appearance under a microscope is a fine-particle layer structure). In addition, naphthalene belongs to a strong carcinogen and has high requirements on environmental protection. Plus BF₃The catalyst is extremely easy to hydrolyze and deteriorate, and the mixture of the catalyst and HF is difficult to recycle.

For a long time, many scientists have used pure naphthalene to catalyze reactions and have attempted to find a way to produce high quality HFMP. The results demonstrate that HF and F are used₃The B mixture is used for preparing HFMP by the catalytic reaction of pure naphthalene, although the effect is relatively traditional modeThe HFMP was improved, but not much, by only 23.15% over the conventional process, whereas the HF catalyzed resid process improved 130.42% (see table 1).

The invention is designed based on the research of the long-term system theory of the inventor, develops a new way, finds a path for producing HFMP by adopting HF catalysis in a complex system of a multi-benzene ring mixture (petroleum residual oil), and greatly improves the heat conductivity and the graphitization degree of the high-heat-conductivity carbon fiber prepared by the method compared with other methods through proper process adjustment, thereby reaching the application level of aerospace-grade products. The large-scale production of the product can upgrade and upgrade the products in related fields of China, and plays a significant role in promoting.

Claims

1. A method for manufacturing mesophase pitch for high thermal conductive carbon fibers is characterized by comprising the following steps:

(1) mixing the purified residual oil with HF gas at the temperature of 325-400 ℃, stirring and reacting for 2-5 hours, wherein the introduction speed of the HF gas is 0.01-0.20 mol/min per kilogram of residual oil, and preparing an intermediate phase pitch intermediate for high-thermal-conductivity carbon fibers;

(2) and (2) reacting the intermediate phase pitch intermediate for the high-thermal-conductivity carbon fibers prepared in the step (1) for 2-5 hours at 2800-3200 Pa and 350-450 ℃, and cooling to prepare the intermediate phase pitch for the high-thermal-conductivity carbon fibers.

2. The method according to claim 1, wherein in the step (1), the HF gas has a water content of 0.

3. The method of claim 1, wherein in step (1), the density of the residue is 1.05 to 1.10g/cm³The viscosity is 18-20 Pa.S, the condensation point is 23.5-24.5 ℃, the flash point is 215-225 ℃, and the water content is 0.

4. The method according to claim 1, wherein in the step (1), the HF gas is introduced at a rate of 0.05mol/min, 0.10mol/min, 0.15mol/min or 0.20mol/min per kg of the residue.

5. The method according to claim 1, wherein in the step (1), the HF gas is introduced at a rate of 0.05 to 0.15mol/min per kg of the residue.

6. The method according to claim 1, wherein in the step (1), the HF gas is introduced at a rate of 0.10 to 0.20mol/min per kg of the residue.

7. The method according to claim 1, wherein in the step (1), the HF gas is introduced at a rate of 0.10 to 0.15mol/min per kg of the residue.

8. The method of claim 1, wherein in step (1), the reaction temperature is 330 ℃, 340 ℃, 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃ or 400 ℃.

9. The method of claim 1, wherein in step (1), the reaction temperature is from 350 ℃ to 400 ℃.

10. The method of claim 1, wherein in step (1), the reaction temperature is 330 ℃ to 380 ℃.

11. The method of claim 1, wherein in step (1), the reaction temperature is 350 ℃ to 380 ℃.

12. The method of claim 1, wherein in step (1), the reaction time is 2.5 hours, 3 hours, 3.5 hours, 4 hours, or 4.5 hours.

13. The method according to claim 1, wherein in the step (1), the reaction time is 2.5 to 4 hours.

14. The method according to claim 1, wherein in the step (1), the reaction time is 3 to 4.5 hours.

15. The method according to claim 1, wherein in the step (1), the reaction time is 3 to 4 hours.

16. The method of claim 1, wherein in step (2), the reaction temperature is 380 ℃, 390 ℃, 400 ℃, 410 ℃ or 420 ℃.

17. The method of claim 1, wherein in step (2), the reaction temperature is 390 to 420 ℃.

18. The method of claim 1, wherein in step (2), the reaction temperature is 380 ℃ to 410 ℃.

19. The method of claim 1, wherein in step (2), the reaction temperature is 390 to 410 ℃.

20. The method of claim 1, wherein in step (2), the reaction time is 2.5 hours, 3 hours, 3.5 hours, 4 hours, or 4.5 hours.

21. The method according to claim 1, wherein in the step (2), the reaction time is 2.5 to 4 hours.

22. The method according to claim 1, wherein in the step (2), the reaction time is 3 to 4.5 hours.

23. The method according to claim 1, wherein in the step (2), the reaction time is 3 to 4 hours.

24. The preparation method of the high-thermal-conductivity carbon fiber is characterized by comprising the following steps:

(i) spinning the high-thermal-conductivity carbon fiber prepared by the method in claim 1 by using mesophase pitch at a drawing speed of 400-450 m/min to prepare a primary spun yarn;

25. The process of claim 24, wherein in step (i), the draw rate is 410 m/min, 415 m/min, 420 m/min, 425 m/min, 430 m/min, 435 m/min, or 440 m/min.

26. The method of claim 24, wherein in step (i), the concentration is from 410 to 430 m/min.

27. The method of claim 24, wherein in step (i), 420 to 440 m/min.

28. The method of claim 24, wherein in step (i), 420 to 430 meters per minute.

29. The method according to claim 24, wherein in the step (ii), the oxidation treatment temperature is 290 ℃, 295 ℃, 300 ℃, 305 ℃, or 310 ℃.

30. The method according to claim 24, wherein in the step (ii), the temperature of the oxidation treatment is 295 to 310 ℃.

31. The method according to claim 24, wherein in the step (ii), the oxidation treatment temperature is 290 to 305 ℃.

32. The method according to claim 24, wherein in the step (ii), the temperature of the oxidation treatment is 295 to 305 ℃.

33. The method according to claim 24, wherein in the step (ii), the oxidation treatment time is 26min, 27min, 28min, 29min, 30min, 31min, 32min, 33min or 34 min.

34. The method according to claim 24, wherein in the step (ii), the oxidation treatment time is 28 to 34 min.

35. The method according to claim 24, wherein in the step (ii), the oxidation treatment time is 26 to 32 min.

36. The method according to claim 24, wherein in the step (ii), the oxidation treatment time is 28 to 32 min.

37. The method according to claim 24, wherein in the step (ii), the carbonization treatment temperature is 960 ℃, 970 ℃, 980 ℃, 990 ℃, 1000 ℃, 1010 ℃, 1020 ℃, 1030 ℃ or 1040 ℃.

38. The method according to claim 24, wherein in the step (ii), the carbonization treatment temperature is 980 to 1040 ℃.

39. The method according to claim 24, wherein in the step (ii), the carbonization temperature is 960 to 1020 ℃.

40. The method according to claim 24, wherein in the step (ii), the carbonization treatment temperature is 980 to 1020 ℃.

41. The method according to claim 24, wherein in the step (ii), the carbonization treatment time is 19min, 20min or 21 min.

42. The method according to claim 24, wherein in the step (ii), the carbonization time is 19 to 20 min.

43. The method according to claim 24, wherein in the step (ii), the carbonization time is 19 to 21 min.

44. The method according to claim 24, wherein in the step (ii), the carbonization treatment time is 20 to 21 min.

45. The method according to claim 24, wherein in the step (ii), the graphitization treatment temperature is 2420 ℃, 2440 ℃, 2460 ℃, 2480 ℃, 2500 ℃, 2520 ℃, 2540 ℃, 2560 ℃ or 2580 ℃.

46. The method according to claim 24, wherein in the step (ii), the graphitization treatment temperature is 2460 to 2580 ℃.

47. The method according to claim 24, wherein in the step (ii), the graphitization treatment temperature 2420 to 2540 ℃.

48. The method according to claim 24, wherein in the step (ii), the graphitization treatment temperature is 2460 to 2540 ℃.

49. The method according to claim 24, wherein in the step (ii), the graphitization treatment time is 10 min.