CN-116925799-B - Preparation method of isotropic asphalt for coating and spinning

Abstract

The invention relates to a preparation method of isotropic asphalt for coating and spinning, which takes ethylene tar, catalytic cracking slurry oil, medium-low temperature coal tar, bio-tar and other aromatic hydrocarbon-rich heavy oil as raw materials, adopts a fluidized bed reaction mode to carry out hydrogenation stabilization and isomerization modification on the raw materials, obtains pre-polymerized asphalt by fluidized bed hydrogenation tail oil under the induction polymerization action of oxygen-containing linear polymers, carries out oxidation crosslinking reaction on the pre-polymerized asphalt under the action of plasma radiation, further improves the softening point and carbon residue value of the obtained isotropic asphalt product, inhibits the generation of mesophase optical structures, and simultaneously has relatively concentrated molecular weight distribution in the isotropic asphalt product, and shows excellent coating performance and homogeneous melt spinning performance.

Inventors

• LIU DONG
• LOU BIN
• SHI NAN
• WEN FUSHAN
• LIU XIAODONG

Assignees

• 中国石油大学(华东)

Dates

Publication Date

20260508

Application Date

20230801

Claims (3)

1. 1. The preparation method of isotropic asphalt for coating and spinning uses aromatic-rich oil as raw oil, wherein the aromatic-rich oil is one or more selected from ethylene tar, catalytic cracking slurry oil, medium-low temperature coal tar or biological tar, and is characterized by comprising the following steps: (1) The method comprises the steps of realizing hydrogenation stabilization and isomerism modification of raw oil through a boiling bed reaction mode to obtain hydrogenated tail oil, wherein the boiling bed reaction adopts a transition metal/silicon-aluminum zeolite-based catalyst, the reaction temperature is 250-350 ℃, the initial pressure of hydrogen is 1-8MPa, the reaction time is 0.5-4h, and the transition metal is selected from platinum, nickel or molybdenum; (2) Adding an oxygen-containing linear polymer into the hydrogenated tail oil to perform an induced polymerization reaction to obtain pre-polymerized asphalt, wherein the oxygen-containing linear polymer is phenolic resin or polyacrylic acid, the addition amount of the oxygen-containing linear polymer is 1-10wt% of the mass of the hydrogenated tail oil, the induced polymerization reaction temperature is 150-350 ℃, and the reaction time is 1-2h; (3) The preparation method comprises the steps of carrying out homogeneous oxidative crosslinking reaction on the pre-polymerized asphalt under the simultaneous actions of oxidizing gas bubbling and plasma irradiation to obtain isotropic asphalt for coating and spinning, wherein the softening point is 220-280 ℃, the carbon residue value is more than or equal to 70%, the temperature of the homogeneous oxidative crosslinking reaction is 200-350 ℃, the reaction time is 1-10 hours, the plasma irradiation dose is 10-100kGy, the oxidizing gas is one of air, oxygen and ozone/nitrogen mixed gas, and the gas flow is 0.5-5.0L.min -1 ·kg -1 .
2. 2. The isotropic pitch for coating and spinning obtained by the production process according to claim 1.
3. 3. The isotropic pitch for cladding and spinning according to claim 2, wherein pitch-based fiber filaments formed after the isotropic pitch spinning are subjected to a pre-oxidation treatment at 300 ℃, and carbon fibers obtained by carbonizing 2 h at 1200 ℃ after the pre-oxidation treatment have a tensile strength of 937-992 MPa.

Description

Preparation method of isotropic asphalt for coating and spinning Technical Field The invention relates to a preparation method of isotropic asphalt for coating and spinning, belonging to the technical field of preparation of high-grade novel carbon materials. Background Carbon fibers are excellent lightweight materials, however, the high cost of carbon fibers and the complex manufacturing process greatly limit the application of carbon fiber composites to automobiles. Therefore, it is urgent to reduce the cost of carbon fibers. The asphalt-based carbon fiber has light weight, small density, strong corrosion resistance and wear resistance, very high electric conductivity and thermal conductivity and the like, and is widely applied to the fields of ultrahigh heat conduction materials, aviation aircraft manufacturing, novel building reinforcing materials, automobile component materials, sports goods, wind power generation and the like. In view of the production cost and mechanical properties of carbon fibers, isotropic pitch-based carbon fibers are considered as one of the most desirable candidate materials. However, it remains a great challenge to obtain cost-effective isotropic pitch-based carbon fibers with excellent mechanical properties. The lithium ion battery cathode materials which are commercially applied on a large scale are mainly graphite (including natural graphite, artificial graphite and MCMB), and the rest of the materials such as soft carbon, hard carbon, silicon/carbon composite materials, lithium titanate and the like are in the experimental development stage and are produced in a small amount. The raw materials of the graphite cathode material mainly comprise natural graphite, petroleum coke, asphalt coke, needle coke and coated asphalt. In order to overcome some structural defects existing in graphite, the graphite is subjected to coating treatment according to different application requirements, so that the first irreversible capacity of the graphite is reduced, and the cycle performance is improved. Generally, all natural graphite negative electrode materials need to be coated, and coated asphalt has a quite large market. There have been many attempts in the prior art to produce isotropic asphalt of excellent properties. CN116288816A discloses a preparation method of isotropic pitch-based carbon fiber, which comprises the following steps of treating ethylene tar in nitrogen atmosphere, mixing with medium steel coal tar pitch, dissolving in benzene to obtain mixed pitch, adding nitrogen-bromosuccinimide, mechanically stirring under the irradiation of a xenon lamp to obtain brominated mixed pitch, removing benzene in the mixed pitch by distillation, then treating to obtain debrominated polymer pitch, preparing pitch fiber by a melt spinning machine, heating in a tube furnace, and obtaining isotropic pitch-based carbon fiber by oxygen and then nitrogen. CN115466626a discloses a preparation method of high-quality isotropic asphalt, which is obtained by mixing brominated methylnaphthalene and coal asphalt to perform a co-carbonization reaction, and adopts the co-carbonization method to improve the reactivity of the coal asphalt, solve the defect that the coal asphalt is not beneficial to polymerization, improve the rheological property of the polymerized asphalt, and further improve the polymerization degree of the synthetic asphalt. CN115558306a provides a preparation method of an isotropic asphalt material, the isotropic asphalt material is obtained by mixing a base material and a modified material and then stirring the mixture at a high temperature, and a polymer chain structure in the modified material is grafted to an aromatic molecular structure of the base material, so that formation of a large planar sheet structure is prevented, formation of an anisotropic structure material is further inhibited, and the isotropic asphalt material is obtained. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a preparation method of isotropic asphalt for coating and spinning, which sequentially adopts fluidized bed hydrogenation stabilization and isomerization modification, induced polymerization of oxygen-containing linear polymers and plasma radiation oxidation crosslinking reaction, further improves the softening point and carbon residue value of the obtained isotropic asphalt product, inhibits the generation of mesophase optical structures, ensures that the molecular weight distribution of the obtained isotropic asphalt product is relatively concentrated, and shows excellent coating performance and homogeneous melt spinning performance. The invention aims at adopting the following technical scheme: the preparation method of isotropic pitch for coating and spinning uses one or more of aromatic oil-rich oil such as ethylene tar, catalytic cracking slurry oil, medium-low temperature coal tar, bio-tar and the like as raw oil, and comprises the following s