Isotropic coated asphalt and preparation method thereof
By treating aromatic oils with ultrasonic cavitation, the problems of high energy consumption and long preparation time in coating asphalt preparation have been solved. This has enabled the preparation of isotropic coating asphalt with low energy consumption and short procedures, improving product performance and reducing production costs.
Patent Information
- Application Number
- CN202510996451.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-18
- Publication Date
- 2025-11-14
AI Technical Summary
The existing process for preparing coated asphalt is energy-intensive and time-consuming, leading to increased costs and severe product homogenization.
Aromatic oil is treated with ultrasonic cavitation. High-temperature and high-pressure bubbles are formed in the liquid-phase aromatic oil by ultrasonic waves, which break the C-C bonds and carry out the cross-linking reaction of the aromatic oil to prepare isotropic coated asphalt, avoiding external heat source heating and gas introduction.
This technology enables the preparation of isotropic coated asphalt with low energy consumption and short procedures, improving product performance and reducing production costs.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of asphalt preparation, and more specifically, to an isotropic coated asphalt and its preparation method. Background Technology
[0002] Driven by the combined effects of power batteries, energy storage batteries, and consumer batteries, the market demand for coated asphalt materials used in the modification of lithium-ion battery anode materials has surged and is expected to continue growing until at least 2030. Currently, natural graphite, as a lithium-ion battery anode material, suffers from structural defects and numerous surface side reactions, leading to a continuous consumption of active lithium during battery cycling. This results in a certain degree of decline in battery cycle life, fast-charging rate performance, energy density, and initial efficiency. As the mainstream graphite product in China, especially with the increasing demand for fast charging, the need for coating treatment to reduce specific surface area and improve electrolyte wettability is becoming increasingly necessary. Coating materials, as essential for anode modification and upgrading, by coating a layer of amorphous carbon onto the graphite surface, retain the high capacity and low voltage of graphite while possessing good compatibility with electrolytes, significantly improving its rate performance and cycle performance.
[0003] Statistics show that coated asphalt accounts for approximately 10% of the anode material usage. Currently, the raw materials for coated asphalt preparation both domestically and internationally include coal tar pitch, petroleum pitch, and natural pitch. Preparation methods mainly involve separation and modification technologies. Separation technologies primarily include vacuum flash distillation and short-path molecular distillation, while modification technologies mainly employ air oxidation, thermal polymerization, and catalytic cross-linking. In actual production, separation technologies can be used individually or in combination with modification technologies, depending on the characteristics of the raw materials and production requirements. Air oxidation involves first adding the raw materials to a reaction vessel and heating them to the reaction temperature. During heating, continuous stirring is maintained, and a certain amount of air is introduced as an oxidant. The reaction is kept at a constant temperature for a period of time, resulting in the coated asphalt product. The principle is that asphalt molecules undergo oxidative cross-linking under the oxidation of air, forming larger spatially structured macromolecules, which can improve the product performance and yield of coated asphalt. This method is simple to operate and widely used, but the reaction time is long.
[0004] In recent years, the cost of coated asphalt has been declining. Consequently, both the quality and price of coated asphalt have fluctuated dramatically. Traditional separation and modification technologies suffer from high energy consumption, long processing times, numerous procedures, and severe homogenization.
[0005] Therefore, the development of an isotropic coated asphalt preparation process with low energy consumption, short procedures, and fast flow is urgently needed. Summary of the Invention
[0006] In view of this, the present invention aims to provide an isotropic coated asphalt and its preparation method to solve the problems of high energy consumption and long preparation time of coated asphalt in the prior art.
[0007] To solve the above-mentioned technical problems, this application is implemented as follows:
[0008] This invention provides a method for preparing isotropic coated bitumen, comprising the following steps:
[0009] Aromatic oil is subjected to ultrasonic cavitation treatment to obtain isotropic coated asphalt.
[0010] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the softening point of the aromatic oil is -5 to 55°C.
[0011] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the mass content of toluene-insoluble matter in the aromatic oil is 1 to 15.5 wt%.
[0012] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the mass content of quinoline insoluble matter in the aromatic oil is 0-1%.
[0013] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the coking value of the aromatic oil is 4-10 wt%.
[0014] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the aromatic oil includes at least one of ethylene tar, catalytic cracking slurry, coal tar, and bio-tar.
[0015] Preferably, in the above-mentioned method for preparing isotropic coated asphalt, the power of the ultrasonic cavitation treatment is 0.1 to 40 kW.
[0016] Preferably, in the above-mentioned method for preparing isotropic coated asphalt, the frequency of the ultrasonic cavitation treatment is 10-280MHz.
[0017] Preferably, in the above-mentioned method for preparing isotropic coated asphalt, the ultrasonic cavitation process involves: first heating to a preset temperature to make the aromatic oil a flowing liquid phase; then heating to the reaction temperature to carry out the reaction.
[0018] Preferably, in the above-mentioned method for preparing isotropic coated asphalt, the preset temperature is 0-85℃.
[0019] Preferably, in the above-mentioned method for preparing isotropic coated bitumen, the reaction temperature is 280–380°C and the reaction time is 0.5–400 min.
[0020] The present invention also provides a method for preparing isotropic coated asphalt, which yields isotropic coated asphalt.
[0021] The beneficial technical effects of the present invention through the above technical solution are as follows:
[0022] This invention utilizes ultrasonic cavitation to cavitate liquid aromatic oil. During the negative pressure of cavitation, the flow phase of the aromatic oil liquid phase asphalt decreases, allowing the aromatic oil components surrounding the bubbles to contact and condense into asphalt components. When cavitation relaxes to create positive pressure, the bubbles break, instantly generating jets of several thousand degrees Celsius (nearly 5000°C) and pressures up to hundreds of atmospheres (500 bar), breaking the C / C bonds of the aromatic oil organic components and forming atomic states. Simultaneously, the contact area between the aromatic oil components and oxygen in the air after cavitation explosion expands, allowing for multi-dimensional cross-linking of the aromatic oil atomic components surrounding the bubbles. Furthermore, due to reduced fluidity and the involvement of oxygen, aromatic oil molecules can form a large number of free radicals. As ultrasonic cavitation continues, the aromatic oil undergoes continuous cross-linking polymerization reactions to obtain asphalt.
[0023] Therefore, asphalt does not require external heat source heating above 120°C, nor does it require additional separate gas introduction; it only needs to react in an open container with air. Under the cavitation of an ultrasonic probe, by controlling the reaction time, isotropic, highly coated asphalt products with varying molecular weights and contents can be prepared. Other features and advantages of this invention will be described in detail in the following detailed description section. Detailed Implementation
[0024] This invention discloses an isotropic coated bitumen and its preparation method. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.
[0025] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges or individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0026] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.
[0027] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.
[0028] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.
[0029] This invention provides a method for preparing isotropic coated bitumen, comprising the following steps:
[0030] Aromatic oil is subjected to ultrasonic cavitation treatment to obtain isotropic coated asphalt.
[0031] In this invention, the softening point of the aromatic oil is preferably -5 to 55°C, more preferably 0 to 30°C, and even more preferably 10 to 20°C.
[0032] In this invention, the mass content of toluene-insoluble matter in the aromatic oil is preferably 1 to 15.5 wt%, more preferably 2 to 12.5 wt%, and even more preferably 5 to 10 wt%.
[0033] In this invention, the mass content of quinoline insoluble matter in the aromatic oil is preferably 0-1%, more preferably 0.1-0.8 wt%, and even more preferably 0.3-0.5%.
[0034] In this invention, the coking value of the aromatic oil is preferably 4 to 10 wt%, more preferably 5 to 9 wt%, and even more preferably 6 to 8 wt%.
[0035] In this invention, the aromatic oil includes at least one of ethylene tar, catalytic cracking slurry oil, coal tar, and biotar.
[0036] In this invention, the power of the ultrasonic cavitation treatment is preferably 0.1 to 40 kW, more preferably 2 to 35 kW, and even more preferably 5 to 20 kW.
[0037] In this invention, the frequency of the ultrasonic cavitation treatment is preferably 10-280MHz, more preferably 20-200MHz, and even more preferably 30-150MHz.
[0038] In this invention, the ultrasonic cavitation process involves first heating to a preset temperature to make the aromatic oil a flowing liquid phase; then heating to the reaction temperature to carry out the reaction.
[0039] In this invention, the preset temperature is preferably 0-85°C, more preferably 5-70°C, and even more preferably 10-50°C.
[0040] In this invention, the reaction temperature is preferably 280–380°C, more preferably 290–350°C, and even more preferably 300–320°C. The reaction time is preferably 0.5–400 min, more preferably 2–340 min, and even more preferably 10–300 min.
[0041] The present invention also provides a method for preparing isotropic coated asphalt, which yields isotropic coated asphalt.
[0042] The present invention will be further described in detail below through examples. All raw materials used in the examples are commercially available.
[0043] Example 1
[0044] A method for preparing isotropic coated bitumen includes the following steps:
[0045] 150g of ethylene tar (softening point (SP) 18℃, toluene insoluble (TI) content 5.3wt%, quinoline insoluble (QI) content <0.13wt%, coking value 6.1%) was added to a 500mL stainless steel reactor. An ultrasonic probe (power 8KW, frequency 120MHz) with a high-temperature resistant ceramic device and a high-temperature resistant enameled wire was immersed in the reactor. The temperature was increased from room temperature to a predetermined temperature of 50℃ at a heating rate of 10℃ / min, ensuring that the raw material was above the softening point by 30 degrees and in a flowing liquid phase. The reaction was carried out at a constant temperature of 310℃ for 120min to obtain isotropic coated asphalt.
[0046] Example 2
[0047] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0048] The softening point of ethylene tar is -5℃, and the content of toluene-insoluble matter is 0.3wt%.
[0049] Everything else is the same as in Example 1.
[0050] Example 3
[0051] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0052] The softening point of ethylene tar is 55℃, and the content of toluene-insoluble matter is 17wt%.
[0053] Everything else is the same as in Example 1.
[0054] Example 4
[0055] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0056] The ultrasonic probe has a power of 0.2KW and a frequency of 20MHz.
[0057] Everything else is the same as in Example 1.
[0058] Example 5
[0059] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0060] The ultrasonic probe has a power of 40KW and a frequency of 200MHz.
[0061] Everything else is the same as in Example 1.
[0062] Example 6
[0063] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0064] The constant temperature reaction time is 20 seconds.
[0065] Everything else is the same as in Example 1.
[0066] Example 7
[0067] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0068] The constant temperature reaction time is 400 min.
[0069] Everything else is the same as in Example 1.
[0070] Comparative Example 1
[0071] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0072] The fabrication process employs an ultrasonic fabrication technique that is not resistant to high temperatures. Specifically, it uses ordinary ceramic components and an ultrasonic probe with a standard wire envelope (1KW power, 50MHz frequency).
[0073] Everything else is the same as in Example 1.
[0074] Comparative Example 2
[0075] The method for preparing isotropic coated bitumen differs from that in Example 1 in that:
[0076] The asphalt was not heated using microwaves; instead, a conventional thermal cross-linking process was employed. That is:
[0077] 150g of aromatic oil (softening point (SP) 18℃, toluene insoluble (TI) content 5.3wt%, quinoline insoluble (QI) content <0.13wt%, coking value 6.1%) was added to a 500mL stainless steel reactor and heated from room temperature to a predetermined temperature of 50℃ at a heating rate of 10℃ / min, forming a flowing liquid phase. The reaction was carried out at a constant temperature of 310℃ for 120min to obtain isotropic coated asphalt.
[0078] Everything else is the same as in Example 1.
[0079] Test Example 1
[0080] (1) The softening point (SP) was determined in accordance with the national standard GB / T2294—2019;
[0081] (2) The coking value (CV) was determined according to GB / T8727—2008;
[0082] (3) The components were determined according to the national standard GB / T 2292—2018. The sample was placed in a filter paper tube and extracted with n-heptane, toluene and quinoline solvents in sequence. After the reflux solvent was clarified, the filter paper tube was dried and weighed to obtain the contents of n-heptane soluble (HS), toluene insoluble (TI) and quinoline insoluble (QI).
[0083] (4) The carbonized asphalt samples were analyzed by polarized light microscopy using a Carl Zeiss AG polarizing microscope (Germany). The test results are shown in Table 1.
[0084] Table 1
[0085]
[0086] Table 1 shows that a higher TI content in the raw materials significantly increases the softening point, coking value, and QI content of the prepared coated asphalt. Conversely, a lower TI content results in a lower TI content. Similarly, higher power, higher frequency, and longer ultrasonic time of the ultrasonic equipment lead to a higher content of isotropic asphalt, and vice versa. In Comparative Example 1, the ultrasonic probe may not be able to sustain high-temperature ultrasonication, resulting in insufficient asphalt formation temperature and a higher proportion of volatile matter, thus producing some anisotropic asphalt. Comparative Example 2, which uses microwave heating, also produces some anisotropic asphalt.
[0087] Aromatic oils with different softening points contain varying amounts of medium-molecular-weight components, toluene-insoluble substances, and quinoline-insoluble substances. These differences are further amplified under rapid, high-temperature, and high-pressure ultrasonic treatment. This results in significant differences in the numerical values observed in the examples.
[0088] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing isotropic coated bitumen, characterized in that, Includes the following steps: Aromatic oil is subjected to ultrasonic cavitation treatment to obtain isotropic coated asphalt.
2. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The softening point of the aromatic oil is -5 to 55°C.
3. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The aromatic oil contains 1 to 15.5 wt% of toluene-insoluble matter. The mass content of quinoline insoluble matter in the aromatic oil is 0-1%; The coking value of the aromatic oil is 4-10 wt%.
4. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The aromatic oil includes at least one of ethylene tar, catalytic cracking slurry oil, coal tar, and bio-tar.
5. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The power of the ultrasonic cavitation treatment is 0.1 to 40 kW.
6. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The frequency of the ultrasonic cavitation treatment is 10–280 MHz.
7. The method for preparing isotropic coated bitumen according to claim 1, characterized in that, The ultrasonic cavitation process involves first heating to a preset temperature to make the aromatic oil a flowing liquid phase; then heating to the reaction temperature to carry out the reaction.
8. The method for preparing isotropic coated bitumen according to claim 7, characterized in that, The preset temperature is 0–85°C.
9. The method for preparing isotropic coated bitumen according to claim 7, characterized in that, The reaction temperature is 280–380°C, and the reaction time is 0.5–400 min.
10. Isotropic coated asphalt prepared by the method of any one of claims 1 to 9.