Asphalt modifier, preparation method thereof and asphalt containing modifier

Abstract

The invention relates to an asphalt modifier and a preparation method thereof and asphalt containing the modifier, and the preparation method comprises the following steps: (1) uniformly mixing styrene tar and a layering solvent, and standing for layering to obtain a supernatant F1 and a subnatant F2; (2) adding alkali liquor into the supernatant F1 for reaction, then filtering to obtain filtrate F3, and heating to remove light components in the filtrate F3 to obtain residual liquid F4; (3) adding butadiene, an initiator and an active agent into the residual liquid F4, mixing, reacting in an inert atmosphere, adding a terminating agent, reacting, dehydrating and drying to obtain S1; and (4) cutting off light components and heavy components from the subnatant F2 to obtain an intermediate component S2, and mixing S1 and S2 in proportion to obtain the asphalt modifier. The asphalt modifier is prepared by taking the hazardous waste styrene tar as the raw material, so that the problems of non-uniform dispersion, unstable storage and the like caused by direct use of the styrene tar are solved, meanwhile, resource utilization of the styrene tar is realized, and the production cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of road asphalt, and particularly relates to an asphalt modifier, a preparation method thereof, and asphalt containing the modifier. Background Art

[0002] Due to the large regional and seasonal temperature differences in China and the increasing traffic volume, higher requirements are put forward for the quality of asphalt pavements. Due to the characteristics of the composition and structure of ordinary asphalt, after aging, its tensile strength is insufficient, resulting in easy fatigue cracking of asphalt, insufficient low-temperature tensile strength, resulting in easy low-temperature cracking of asphalt, and insufficient shear strength at high temperatures, resulting in easy softening of asphalt to form ruts at high temperatures. Therefore, it is necessary to modify the base asphalt.

[0003] In the research of modified asphalt, modified asphalt is usually prepared by doping a modifier in the base asphalt and through physical miscibility or chemical reaction. At present, the modifiers reported in the literature are mainly divided into two types: polymer type and non-polymer type. Among them, polymer-type asphalt modifiers include thermoplastic elastomers, rubber asphalt modifiers, and resins. Styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), polyester elastomer, polyolefin elastomer, etc. all belong to thermoplastic elastomers. Since the preparation process of SBS modified asphalt is simple and the material source is wide, it is the most studied and widely used asphalt modifier at home and abroad. Styrene-butadiene rubber (SBR), natural rubber (NR), chloroprene rubber (CR), etc. all belong to rubber asphalt modifiers, and among them, SBR with good low-temperature performance is widely used.

[0004] Styrene tar is a common solid waste in the production process of styrene, mainly including aromatics, oligomers, inhibitors, etc. In actual production, due to the high carbon-hydrogen ratio of styrene tar, containing a large number of unsaturated bonds and low ash content, its viscosity is relatively large at room temperature (>100 mm 2 / s, 20 °C). At present, most manufacturers burn it as fuel or outsource the disposal, failing to realize the resource utilization of styrene tar, and at the same time reducing the comprehensive cost of the styrene plant. If styrene tar is processed into an asphalt modifier to replace the high-cost additives used in the prior art, it can not only realize the resource utilization of styrene tar but also reduce the preparation cost of modified asphalt.

[0005] Cao Ping et al. (Influence of Styrene Tar on the Properties of Rubber-Modified Asphalt [J]. Fine Petrochemicals, 2012, v.29; No.167(02): 77-80) used the asphalt produced by Liaohe Oilfield as raw material, added rubber powder and styrene tar, and prepared modified asphalt by high-speed shearing method. The influence of rubber powder and styrene tar on the properties of asphalt was investigated, and the aging experiment of the modified asphalt was carried out. It was determined that the optimal mass fraction of rubber powder was 15%, and styrene tar was added to the rubber-modified asphalt with a mass fraction of 15% to enable the rubber powder to swell fully in the asphalt and improve the service performance of the rubber asphalt. The experiment showed that the addition of styrene tar could improve the properties of the rubber-modified asphalt. At this time, the softening point of the asphalt could reach 39.7 °C, the penetration of the asphalt could reach 11 (0.1 mm), and the ductility was 121 cm, meeting the standard of No. 140 road asphalt. The aging experiment showed that the rubber powder coalesced and precipitated after the modification asphalt was aged. This was mainly due to the problems of uneven mixing and poor mechanical properties of the product caused by directly adding styrene tar to the matrix asphalt, resulting in storage instability. At the same time, the instability of the composition of styrene tar itself would also lead to an increase in the instability of the modified asphalt.

[0006] CN103627192A discloses a modified asphalt and its preparation method. The modified asphalt includes the following components: base asphalt, waste rubber powder and composite emulsifier, and their mass ratio is: 100 parts of base asphalt, 10-30 parts of waste rubber powder, and 1-8 parts of composite emulsifier; the composite emulsifier includes coal tar, styrene tar, catalytic cracking slurry with a temperature above 450 °C and polymer modifier, and the mass ratio of each component of the composite emulsifier is: coal tar: 10-80 parts, styrene tar: 3-10 parts, catalytic cracking slurry with a temperature above 450 °C: 30-50 parts, polymer modifier: 1-10 parts. This patent uses styrene tar as one of the components of the composite emulsifier and also needs to use other multiple components in combination. In addition, ultrasonic and high-speed shearing means are required during the preparation of asphalt, and the preparation requirements are relatively high. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the present invention provides an asphalt modifier, its preparation method and asphalt containing the modifier. The present invention uses hazardous waste styrene tar as raw material to prepare an asphalt modifier, solves the problems of uneven dispersion and unstable storage existing in the direct use of styrene tar, and realizes the resource utilization of styrene tar and reduces the production cost.

[0008] The first aspect of the present invention provides a preparation method of an asphalt modifier, including the following steps:

[0009] (1) Mix styrene tar with a layered solvent, and after standing and separating layers, obtain the upper layer liquid F1 and the lower layer liquid F2;

[0010] (2) Add an alkali solution to the upper-layer liquid F1 for reaction, and then filter to obtain a filtrate F3. Heat the filtrate F3 to remove the light components, and obtain a remaining liquid F4;

[0011] (3) Add butadiene, an initiator, and an activator to the remaining liquid F4, mix them, and carry out the reaction under an inert atmosphere. Then add a terminator for reaction, and dehydrate and dry to obtain S1;

[0012] (4) Cut off the light components and heavy components from the lower-layer liquid F2 to obtain an intermediate component S2, and mix S1 and S2 to obtain an asphalt modifier.

[0013] The styrene tar described in step (1) comes from the rectification residue generated in the production process of producing styrene by ethylbenzene dehydrogenation method, and mainly contains components such as styrene, stilbene, diphenylethane, polycyclic aromatic hydrocarbons, and polymerization inhibitor.

[0014] The layering solvent described in step (1) is at least one of straight-chain alkanes, branched-chain alkanes, cycloalkanes, etc. with C4-C10, and preferably at least one of straight-chain alkanes and branched-chain alkanes with C5-C7.

[0015] The mass ratio of the styrene tar to the layering solvent described in step (1) is 1:1-4, preferably 1:2-3.5. The means of mixing the two include but are not limited to stirring, forced circulation, etc., that is, any method and equipment that can achieve sufficient mixing of various substances in the system are acceptable.

[0016] The static layering described in step (1) can be achieved in a separating funnel, a separator, etc. The time for static layering is generally not less than 1 h.

[0017] The alkali described in step (2) is one or several of sodium hydroxide, potassium hydroxide, etc. The mass concentration of the alkali solution is 2.5%-20%, preferably 5%-15%. The volume ratio of the alkali solution to the upper-layer liquid F1 is 1:50-200, preferably 1:80-150. Further, it is preferred to slowly add the alkali solution while stirring to prevent the quality of the recovered product from deteriorating due to rapid addition. The stirring rate is 60-200 rpm, preferably 80-120 rpm.

[0018] The reaction described in step (2) can be carried out in a reactor with both reaction and filtration functions, such as a polymerization inhibitor filter. The polymerization inhibitor filter has both reaction and filtration functions and can avoid blockage caused by the deposition of reaction materials in the pipeline during transportation. Specifically, a reaction tank with a stirring function and an openable / closable bottom is set above the filter. After the reaction is completed, the bottom of the reaction tank is opened, and the mixed liquid enters the filter set below under the action of gravity for filtration to obtain a filtrate and solid substances.

[0019] In step (2), the light components in filtrate F3 can be removed by heating. The heating temperature is generally 50 - 150°C, preferably 65 - 128°C. The evaporated light components can be recycled after recovery, and stirring can be assisted to ensure uniform heating of the material.

[0020] In step (3), the mass ratio of the remaining liquid F4 to butadiene is 1:0.5 - 8, preferably 1:1.2 - 3. The initiator is one or more of alkyllithium, sodium alkyl, calcium alkyl, strontium alkyl, potassium amide, lithium tert-butoxide, etc., and the alkyl group is a straight-chain or branched-chain alkyl group with C3 - C5; the addition amount is 0.05% - 0.25% of the sum of the masses of the remaining liquid F4 and butadiene, preferably 0.09% - 0.13%. The active agent is tetrahydrofuran, and the addition amount is 5% - 15% of the sum of the masses of the remaining liquid F4 and butadiene, preferably 6.5% - 10.5%.

[0021] The specific reaction process in step (3) is as follows: a) First, add 50% of the total amount of the remaining liquid F4, heat up to 40 - 60°C, add the initiator and the active agent, and react for 0.5 - 2 h; b) Introduce all butadiene, heat up to 50 - 70°C, and react for 0.5 - 4 h; c) Add the remaining 50% of the remaining liquid F4, heat up to 70 - 90°C, and react for 0.5 - 2 h.

[0022] The inert atmosphere in step (3) refers to any one of nitrogen atmosphere, argon atmosphere, helium atmosphere, etc.

[0023] The terminator in step (3) is deionized water or lower alcohols, preferably one or more of ethanol, propanol, etc., and the addition amount is 0.025% - 0.25% of the mass of the remaining liquid F4.

[0024] The reaction conditions for adding the terminator in step (3) are: pressure 0.01 - 0.09 MPa, temperature 85 - 105°C.

[0025] The dehydration in step (3) can be carried out using common existing dehydration equipment, such as an extrusion water press; the drying temperature is 40 - 55°C, and the absolute pressure is 5.0 - 7.4 kPa.

[0026] In step (4), the light components and heavy components are cut off from the lower layer liquid F2. The temperature for cutting off the light components is generally lower than 150°C, preferably 95 - 125°C; the heavy components are mainly cut off from the components in the lower layer liquid F2 above 480°C, and atmospheric distillation or vacuum distillation is used.

[0027] In step (4), the mass ratio of S1 to S2 is 1 - 10:1.

[0028] In the second aspect of the present invention, an asphalt modifier is provided, which is prepared by the method of the present invention described above.

[0029] In the third aspect of the present invention, a modified asphalt is provided, which contains the asphalt modifier described in the present invention above. The content of the asphalt modifier is 5%-40% of the mass of the base asphalt, preferably 13%-30%.

[0030] In the fourth aspect of the present invention, a preparation method of modified asphalt is provided. The base asphalt is heated to 130-160°C, and the asphalt modifier prepared by the present invention is added. After stirring reaction and development, the modified asphalt is obtained. The stirring reaction temperature is 155-165°C, the stirring speed is 4000-8000 r / min, preferably 5500-7500 r / min, the duration is 20-300 min, preferably 50-150 min. The development temperature is 150-170°C, and the development time is 2-6 h.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention uses solid hazardous waste styrene tar as a raw material to prepare an asphalt modifier. This modifier can make the base asphalt graft with each other to form a more stable network structure, with better storage stability, and avoid the instability of the modified asphalt caused by the property change of styrene tar.

[0033] (2) The components S1 and S2 contained in the asphalt modifier of the present invention are both prepared from styrene tar and have excellent compatibility. Moreover, the introduction of S2 helps to improve the diffusion degree of S1 in the base asphalt, so that the two are evenly dispersed in the asphalt system, solving the problems of uneven dispersion and unstable storage of directly using styrene tar in the base asphalt.

[0034] (3) Using the modifier prepared from styrene tar to modify the base asphalt reduces the usage amount of conventional additives and saves costs. At the same time, it realizes the resource utilization of solid waste, with significant environmental and economic benefits. Specific Embodiments

[0035] The following specific embodiments are used to further illustrate the method and its effects of the present invention. The embodiments are implemented on the premise of the technical solution of the present invention, and the detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0036] The experimental methods in the following embodiments are all conventional methods in the art unless otherwise specified. The experimental materials used in the embodiments are all purchased from conventional biochemical reagent stores unless otherwise specified.

[0037] The styrene tar in this embodiment comes from the styrene product distillation residue in the ethylbenzene dehydrogenation method styrene production unit of a certain refining enterprise of Sinopec, which mainly contains components such as styrene, stilbene, diphenylethane, polycyclic aromatic hydrocarbons, and polymerization inhibitor.

[0038] The crumb rubber modified asphalt prepared in the embodiments of the present invention is compared with the relevant indicators in the technical requirements of polymer modified asphalt in the Standard "Technical Specifications for Construction of Highway Asphalt Pavements" (J-TGF40-2004).

[0039] Example 1

[0040] (1) Styrene tar and n-hexane are stirred and mixed evenly according to a mass ratio of 1:3, left to stand and separate for 2 h, and the upper layer liquid F1 and the lower layer liquid F2 are obtained by separation.

[0041] (2) A sodium hydroxide solution with a mass fraction of 7% is added to F1, and the volume ratio of the sodium hydroxide solution to F1 is 1:80. Stir and react at 115 rpm and then filter. The filtrate F3 is heated to 75 °C to remove some light components therein, and the remaining liquid F4 is obtained.

[0042] (3) The remaining liquid F4 is mixed with butadiene, butyl lithium, and tetrahydrofuran. The mass ratio of the remaining liquid F4 to butadiene is 1:1.75, and the addition amount of butyl lithium is 0.12% of the sum of the masses of the remaining liquid F4 and butadiene. The addition amount of tetrahydrofuran is 8.5% of the sum of the masses of the remaining liquid F4 and butadiene. The reaction is carried out under a nitrogen atmosphere. Specifically: a) First, add 50% of the total amount of the remaining liquid F4, heat up to 40 °C, add the initiator and the activator, and react for 1 h; b) Introduce all the butadiene, heat up to 50 °C, and react for 2 h; c) Add the remaining 50% of the remaining liquid F4, heat up to 80 °C, and react for 1 h to obtain the glue liquid F5. Add the terminator ethanol to F5, and the addition amount is 0.125% of the mass of the remaining liquid F4. React fully at 0.025 MPa and 90 °C. After the reaction is completed, dehydrate, and dry at 40 °C and 5.0 kPa to obtain S1.

[0043] (4) Cut off the light components and heavy components from the lower layer liquid F2. The temperature for cutting off the light components is 95 °C; cutting off the heavy components mainly means cutting off the components above 480 °C in the lower layer liquid F2, and adopting atmospheric distillation. The remaining substance is S2. Mix S1 and S2 according to a mass ratio of 5:1, which is the asphalt modifier.

[0044] Example 2

[0045] (1) Styrene tar and n-heptane are stirred and mixed evenly according to a mass ratio of 1:2, left to stand and separate for 2 h, and the upper layer liquid F1 and the lower layer liquid F2 are obtained by separation.

[0046] (2) A sodium hydroxide solution with a mass fraction of 12% is added to F1, and the volume ratio of the sodium hydroxide solution to F1 is 1:70. Stir and react at 115 r / min and then filter. The filtrate F3 is heated to 90 °C to remove some light components in the filtrate, and the remaining liquid F4 is obtained.

[0047] (3) Mix the residual liquid F4 with butadiene, sodium butyl, and tetrahydrofuran. The mass ratio of the residual liquid F4 to butadiene is 1:2.5. The addition amount of sodium butyl is 0.2% of the sum of the masses of the residual liquid F4 and butadiene. The addition amount of tetrahydrofuran is 6.5% of the sum of the masses of the residual liquid F4 and butadiene. React under a nitrogen atmosphere. The specific process is as follows: a) First add 50% of the total amount of the residual liquid F4, heat up to 40 °C, add the initiator and activator, and react for 1 h; b) Introduce all the butadiene, heat up to 50 °C, and react for 2 h; c) Add the remaining 50% of the residual liquid F4, heat up to 80 °C, and react for 1 h to obtain the glue liquid F5. Add the terminator ethanol to F5, and the addition amount is 0.2% of the mass of the residual liquid F4. React fully at 0.02 MPa and 100 °C. After the reaction is completed, dehydrate and dry at 45 °C and 6.0 KPa to obtain S1.

[0048] (4) Cut off the light components and heavy components from the lower layer liquid F2. The temperature for cutting off the light components is 125 °C; mainly cut off the components above 480 °C in the lower layer liquid F2 for removing the heavy components. Use atmospheric distillation, and the residue is S2. Mix S1 and S2 according to the mass ratio of 5:1, which is the asphalt modifier.

[0049] Example 3

[0050] (1) Stir and mix styrene tar and isopentane evenly according to the mass ratio of 1:4, stand for layering for 2 h, and separate to obtain the upper layer liquid F1 and the lower layer liquid F2.

[0051] (2) Add a potassium hydroxide solution with a mass fraction of 5% to F1. The volume ratio of the potassium hydroxide solution to F1 is 1:150. Stir and react at 115 r / min and filter. Heat the filtrate F3 to 65 °C to remove some light components in the filtrate to obtain the residual liquid F4.

[0052] (3) Mix the residual liquid F4 with butadiene, potassium amide, and tetrahydrofuran. The mass ratio of the residual liquid F4 to butadiene is 1:1.2. The addition amount of potassium amide is 0.09% of the sum of the masses of the residual liquid F4 and butadiene. The addition amount of tetrahydrofuran is 10.5% of the sum of the masses of the residual liquid F4 and butadiene. React under a nitrogen atmosphere. The specific process is as follows: a) First add 50% of the total amount of the residual liquid F4, heat up to 40 °C, add the initiator and activator, and react for 1 h; b) Introduce all the butadiene, heat up to 50 °C, and react for 2 h; c) Add the remaining 50% of the residual liquid F4, heat up to 80 °C, and react for 1 h to obtain the glue liquid F5. Add the terminator ethanol to F5, and the addition amount is 0.03% of the mass of the residual liquid F4. React fully at 0.085 MPa and 105 °C. After the reaction is completed, dehydrate and dry at 55 °C and 6.5 KPa to obtain S1.

[0053] (4) Cut off the light components and heavy components from the lower layer liquid F2. The temperature for cutting off the light components is 115 °C; the main purpose of cutting off the heavy components is to cut off the components above 480 °C in the lower layer liquid F2. Atmospheric distillation is used, and the residue is S2. Mix S1 and S2 according to the mass ratio of 5:1, which is the asphalt modifier.

[0054] Example 4

[0055] Same as Example 1, except that: the alkane is a mixture of n-pentane and n-heptane, and the mass ratio of the two is 1:2. Finally, an asphalt modifier is prepared.

[0056] Example 5

[0057] Same as Example 1, except that: the alkane is 2-methylpentane. Finally, an asphalt modifier is prepared.

[0058] Example 6

[0059] Same as Example 1, except that: the alkane is cyclohexane. Finally, an asphalt modifier is prepared.

[0060] Example 7

[0061] Same as Example 1, except that: the terminator is deionized water. Finally, an asphalt modifier is prepared.

[0062] Example 8

[0063] Same as Example 1, except that: mix S1 and S2 according to the mass ratio of 10:1, which is the asphalt modifier. Finally, an asphalt modifier is prepared.

[0064] Example 9

[0065] Same as Example 1, except that: mix S1 and S2 according to the mass ratio of 1:1, which is the asphalt modifier. Finally, an asphalt modifier is prepared.

[0066] Comparative Example 1

[0067] Same as Example 1, except that: directly use S2 as the final asphalt modifier.

[0068] Comparative Example 2

[0069] Same as Example 1, except that: directly use S1 as the final asphalt modifier.

[0070] Comparative Example 3

[0071] Same as Example 1, except that: the styrene tar is not pretreated with alkane and is directly added with lye for subsequent reaction, and finally S3 is prepared as the modified asphalt additive.

[0072] Comparative Example 4

[0073] Same as Example 1, except that in the preparation process of S1, filtrate F3 directly replaces residual liquid F4 for reaction, that is, the process of removing light components from filtrate F3 is not carried out, and finally an asphalt modifier is obtained.

[0074] Comparative Example 5

[0075] Same as Example 1, except that in the preparation process of S1, no initiator or activator is added to residual liquid F4, and finally an asphalt modifier is obtained.

[0076] Comparative Example 6

[0077] Same as Example 1, except that in the preparation process of S1, terminator is not added to glue liquid F5 for reaction, and finally an asphalt modifier is obtained.

[0078] Comparative Example 7

[0079] Same as Example 1, except that light components and heavy components are not removed from F2, and it is directly mixed with S1.

[0080] Test Example 1

[0081] Melt the base asphalt at 135 °C, slowly add the asphalt modifier at 15% of the mass of the base asphalt, while raising the temperature to 160 °C and starting stirring, stir at 7000 r / min for 60 min, and finally place it in an oven at 160 °C for development for 2.5 h to obtain the modified asphalt. Detect the product performance of the prepared modified asphalt, and the results are shown in Table 1. The modified asphalt is obtained and compared with the relevant indicators in the standard "Technical Specification for Construction of Highway Asphalt Pavement" (J-TGF40-2004).

[0082] Table 1 Product Performance of Examples and Comparative Examples

[0083]

Claims

1. A preparation method of an asphalt modifier, characterized in that It includes the following steps: (1) Mix styrene tar with a separating solvent, and after standing for separation, obtain the upper layer liquid F1 and the lower layer liquid F2; (2) Add an alkali solution to the upper layer liquid F1 for reaction, then filter to obtain the filtrate F3, and heat to remove the light components in the filtrate F3 to obtain the remaining liquid F4; (3) Add butadiene, an initiator, and an activator to the remaining liquid F4 and mix them, react under an inert atmosphere, then add a terminator for reaction, and dehydrate and dry to obtain S1; (4) Cut off the light components and heavy components from the lower layer liquid F2 to obtain the intermediate component S2, and mix S1 and S2 to obtain the asphalt modifier.

2. The method according to claim 1, wherein: The styrene tar described in step (1) comes from the rectification residue generated in the production process of producing styrene by ethylbenzene dehydrogenation, and mainly contains styrene, stilbene, diphenylethane, polycyclic aromatic hydrocarbons, and polymerization inhibitors.

3. The method according to claim 1, characterized in that: The separating solvent described in step (1) is at least one of straight-chain alkanes, branched-chain alkanes, and cycloalkanes with C4-C10, preferably at least one of straight-chain alkanes and branched-chain alkanes with C5-C7.

4. The method according to claim 1 or 3, characterized in that: The mass ratio of the styrene tar to the separating solvent described in step (1) is 1:1-4, preferably 1:2-3.

5.

5. The method according to claim 1, wherein: The standing separation described in step (1) is achieved in a separating funnel or a separator, and the standing separation time is not less than 1 h.

6. The method according to claim 1, characterized in that: The alkali described in step (2) is one or several of sodium hydroxide and potassium hydroxide, and the mass concentration of the alkali solution is 2.5%-20%, preferably 5%-15%.

7. The method according to claim 1, wherein: The volume ratio of the alkali solution to the upper layer liquid F1 described in step (2) is 1:50-200, preferably 1:80-150.

8. The method according to claim 1, characterized in that: The alkali solution is slowly added while stirring, and the stirring rate is 60-200 rpm, preferably 80-120 rpm.

9. The method according to claim 1, characterized in that: The light components in the filtrate F3 can be removed by heating in step (2), and the heating temperature is generally 50-150 °C, preferably 65-128 °C.

10. The method according to claim 1, characterized in that: The mass ratio of the remaining liquid F4 to butadiene in step (3) is 1:0.5-8, preferably 1:1.2-3; the initiator is one or several of alkyllithium, alkylsodium, alkylcalcium, alkylstrontium, potassium amide, and lithium tert-butoxide, where the alkyl group is a straight-chain or branched-chain alkyl group with C3-C5; the addition amount of the initiator is 0.05%-0.25% of the sum of the masses of the remaining liquid F4 and butadiene, preferably 0.09%-0.13%; the activator is tetrahydrofuran, and the addition amount is 5%-15% of the sum of the masses of the remaining liquid F4 and butadiene, preferably 6.5%-10.5%.

11. The method according to claim 1 or 11, characterized in that: The specific reaction process in step (3) is as follows: a) First add 50% of the total amount of the remaining liquid F4, heat to 40-60 °C, add the initiator and the activator, and react for 0.5-2 h; b) Introduce all the butadiene, heat to 50-70 °C, and react for 0.5-4 h; c) Add the remaining 50% of the remaining liquid F4, heat to 70-90 °C, and react for 0.5-2 h.

12. The method according to claim 1, characterized in that: The inert atmosphere described in step (3) refers to any one of a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere.

13. The method according to claim 1, wherein: The terminator described in step (3) is deionized water or a lower alcohol, preferably one or several of ethanol and propanol, and the addition amount is 0.025%-0.25% of the mass of the remaining liquid F4.

14. The method according to claim 1, characterized in that: The reaction conditions for adding the terminator described in step (3) are as follows: the pressure is 0.01 - 0.09 MPa, and the temperature is 85 - 105 °C.

15. The method according to claim 1, wherein: The dehydration in step (3) is carried out using an extrusion water compressor; the drying temperature is 40 - 55 °C, and the absolute pressure is 5.0 - 7.4 kPa.

16. The method according to claim 1, wherein: In step (4), the light components and heavy components are cut off from the lower layer liquid F2. The temperature for cutting off the light components is generally lower than 150 °C, preferably 95 - 125 °C; the heavy components are mainly cut off from the components above 480 °C in the lower layer liquid F2, and atmospheric distillation or vacuum distillation is used.

17. The method according to claim 1, characterized in that: In step (4), the mass ratio of S1 to S2 is 1 - 10:

1.

18. An asphalt modifier, characterized in that It is prepared by using the method described in any one of claims 1 - 17.

19. A modified asphalt, characterized in that It contains the asphalt modifier prepared by using the method described in any one of claims 1 - 17, and the content of the asphalt modifier is 5% - 40% of the mass of the matrix asphalt, preferably 13% - 30%.

20. A method for preparing the modified asphalt according to claim 19, characterized in that: The matrix asphalt is heated to 130 - 160 °C, and the asphalt modifier prepared by using the method described in any one of claims 1 - 17 or the asphalt modifier described in claim 18 is added, and the modified asphalt is obtained through stirring reaction and development.

21. The method according to claim 20, wherein: The stirring reaction temperature is 155 - 165 °C, the stirring speed is 4000 - 8000 r / min, preferably 5500 - 7500 r / min, the duration is 20 - 300 min, preferably 50 - 150 min; the development temperature is 150 - 170 °C, and the development time is 2 - 6 h.

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