Warm emulsified modified asphalt and method for preparing the same

Abstract

The application discloses normal-temperature emulsified modified asphalt and a preparation method thereof, and specifically comprises the following steps: (1) heating asphalt to a molten state, adding a modifier, stirring under constant temperature, cooling after modification, then adding a solvent, continuously stirring and cooling to normal temperature, and preparing normal-temperature flow-state modified asphalt; (2) mixing an emulsifier, pure water and a stabilizer to obtain a mixed solution, uniformly stirring under heating, adjusting the pH value of the mixed solution by using a pH regulator to obtain a soap solution, and keeping the soap solution at normal temperature for standby; (3) mixing and emulsifying the normal-temperature flow-state modified asphalt with the soap solution; and (4) recovering the solvent in the material liquid after emulsification, and discharging to obtain normal-temperature emulsified modified asphalt. The application solves the problem of poor emulsification effect caused by a large temperature difference between the soap solution and molten asphalt in a conventional modification-emulsification process, solves the problem of abnormal emulsification quality fluctuation caused by high-temperature emulsification, and is beneficial to improving the performance of the emulsified modified asphalt.

Description

Technical Field

[0001] This invention belongs to the field of asphalt modification and emulsification technology, specifically relating to a room-temperature emulsified modified asphalt and its preparation method. Background Technology

[0002] Currently, there are three main approaches to preparing modified emulsified asphalt both domestically and internationally: modification before emulsification, emulsification before modification, and simultaneous emulsification and modification. From an emulsification perspective, the modification-before-emulsification process yields the best emulsification effect. The conventional modification-before-emulsification process involves the following steps: heating and melting the asphalt, adding the modifier, maintaining a constant temperature (high temperature) after modification to preserve the flowability of the modified asphalt; preparing a soap solution and maintaining a constant temperature (low temperature) for later use; preheating the emulsifier and then heating the soap solution; starting the emulsifier; adding the molten modified asphalt and mixing it with the soap solution; and using the emulsifier to perform high-speed shearing of the modified asphalt to form the emulsified modified asphalt product. The above-described process of modifying and then emulsifying the asphalt has significant limitations. For example, to maintain the flowability of the modified asphalt, it needs to be kept at a constant temperature of up to 180°C, resulting in very high energy consumption. Meanwhile, the soap solution has a lower temperature, creating a large temperature difference with the modified asphalt, leading to poor emulsification. Furthermore, the high emulsification temperature (to maintain the flowability of the modified asphalt) easily causes foaming and demulsification during the emulsification process, making it difficult to guarantee the quality of the emulsified modified asphalt. Additionally, emulsification at high temperatures requires controlling the viscosity of the modified asphalt; higher viscosity directly affects the emulsification effect. Therefore, the amount of modifier added during the modification stage also needs to be controlled, making it difficult to prepare high-performance emulsified modified asphalt.

[0003] Therefore, it is necessary to propose a new process of modification followed by emulsification to solve the above problems. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a room-temperature emulsified modified asphalt and its preparation method. This method solves the problem of poor emulsification effect caused by the large temperature difference between the soap solution and molten asphalt in conventional pre-modification and post-emulsification processes. Furthermore, it solves the problem of abnormal fluctuations in emulsification quality caused by high-temperature emulsification, which is beneficial for improving the performance of emulsified modified asphalt.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for preparing room-temperature emulsified modified asphalt, comprising the following steps:

[0007] (1) Heat the asphalt to a molten state, add the modifier, and stir the asphalt and modifier together while keeping the asphalt in a molten state. After the modification is completed, cool down, add the solvent, and continue stirring until room temperature is reached to obtain room temperature flowable modified asphalt for use.

[0008] (2) Prepare room temperature soap solution for later use. Specifically, mix emulsifier, pure water and stabilizer to obtain a mixed solution. Heat the mixed solution and stir it evenly. Before or after cooling down, use pH adjuster to adjust the pH value of the mixed solution to obtain soap solution. The soap solution is kept at room temperature for later use.

[0009] (3) Emulsify and mix room temperature fluidity-modified asphalt with room temperature soap solution to obtain a mixture after emulsification;

[0010] (4) The solvent in the mixture is recovered and discharged to obtain room temperature emulsified modified asphalt.

[0011] This invention adds a solvent compatible with asphalt during the asphalt modification process to reduce the viscosity of the modified asphalt, allowing it to maintain its fluidity at room temperature. During emulsification, the temperature of the modified asphalt is close to that of the soap solution, solving problems such as foaming and demulsification during emulsification and ensuring the emulsification effect. Furthermore, because the modified asphalt and solvent can maintain their fluidity at room temperature and the emulsification effect is guaranteed, the amount of modifier added can be increased during asphalt modification to improve the performance of the final product.

[0012] Preferably, the solvent is an organic solvent compatible with asphalt and with a boiling point below 90°C, such as acetone. The solvent has no effect on the properties of the emulsified modified asphalt; its function is to ensure that the modified asphalt maintains its flowability at room temperature. The present invention uses a low-boiling-point organic solvent, which has the advantage of facilitating solvent recycling.

[0013] Preferably, the solvent is any one or more of acetone, butanone, and tetrahydrofuran.

[0014] Preferably, the solvent is acetone.

[0015] In conventional processes, due to the high temperature of modified asphalt and the large temperature difference between it and soap solution, foaming and demulsification inevitably occur during emulsification. To ensure the quality of emulsification, the emulsification time needs to be extended, generally exceeding 10 minutes. Even with extended emulsification time, the quality of emulsification is difficult to guarantee, and the product quality of emulsified modified asphalt fluctuates significantly. In this invention, in step (3), the emulsification time of room-temperature fluidized modified asphalt mixed with soap solution is less than 3 minutes. Because this invention prepares modified asphalt that can maintain fluidity at room temperature, it changes the high-temperature emulsification step in the conventional process of modification followed by emulsification. Since the emulsification effect of modified asphalt and soap solution in this invention is guaranteed, the problems of foaming and demulsification are solved. This invention shortens the emulsification time of room-temperature fluidized modified asphalt mixed with soap solution to within 3 minutes (conventional high-temperature emulsification requires more than 10 minutes of emulsification time), thereby improving emulsification efficiency while ensuring the emulsification effect.

[0016] Preferably, in step (1), the amount of the modifier added is greater than 3% by mass fraction, and more preferably, the amount of the modifier added is greater than 5%.

[0017] In conventional pre-modification followed by emulsification processes, the amount of modifier added needs to be controlled below 3%. Otherwise, the viscosity of the modified asphalt increases, and the high-temperature emulsification effect will be worse. Therefore, in existing technologies, the emulsification effect restricts the asphalt modification effect. To ensure the emulsification effect of asphalt, the viscosity of the modified asphalt needs to be strictly controlled, that is, the amount of modifier added needs to be strictly controlled. This invention, however, solves the problems existing in the modified asphalt emulsification process by adding a solvent to obtain modified asphalt that maintains its fluid dynamics at room temperature. It removes the limitation of the emulsification process on the asphalt modification process. This invention allows for the addition of more modifiers (more than 5%) during asphalt modification to obtain modified asphalt with superior performance (high and low temperature performance, rubber properties, etc.).

[0018] Preferably, in step (1), the preparation steps of the modified asphalt are as follows:

[0019] The asphalt is heated to a molten state. When the asphalt temperature reaches 160℃~180℃, the modifiers SBR and SBS are added. The mixture is stirred for 2~3 hours while remaining in the molten state for modification, for example, stirring for 2.5 hours at 175℃. After the modification is completed, the temperature is lowered to below 140℃, and then the solvent is added. Stirring continues until room temperature is reached, and room temperature flow-modified asphalt is obtained for use.

[0020] Preferably, in step (1), the solvent is added only after the modification is completed and the temperature is cooled to below 120°C, and then the temperature is rapidly reduced to room temperature during stirring to reduce solvent evaporation.

[0021] Preferably, in step (2), the emulsifier, pure water and stabilizer are mixed and stirred at a temperature not higher than 80°C to obtain a mixed solution. The mixed solution is cooled to room temperature. Before or after the mixed solution cools to room temperature, a pH adjuster is added to adjust the pH value of the mixed solution to the required value to obtain a room temperature soap solution. More preferably, the mixed solution is heated to 50-60°C and stirred.

[0022] Preferably, in step (2), the emulsifier is an anionic emulsifier or a cationic emulsifier;

[0023] Anionic oxidants have an alkaline pH value. Therefore, when the emulsifier is anionic, the pH adjuster is an alkaline adjuster with alkaline substances as the main component.

[0024] The pH value of cationic oxidants is acidic. When the emulsifier is a cationic emulsifier, the pH adjuster is an acidic adjuster with acidic substances as the main components.

[0025] Adjusting the pH value of the soap solution is to maintain the stability of the soap solution system.

[0026] Preferably, when the emulsifier is an anionic emulsifier, the pH adjuster is any one of sodium hydroxide, sodium carbonate, sodium bicarbonate, or potassium carbonate;

[0027] When the emulsifier is a cationic emulsifier, the pH adjuster is any one of hydrochloric acid, phosphoric acid, tartaric acid, lactic acid, or acetic acid.

[0028] Preferably, in step (4), the solvent in the mixture is recovered by vacuum distillation at 40–60°C. Alternatively, other suitable recovery methods can also be used in this invention.

[0029] In a second aspect, the present invention provides a room-temperature emulsified modified asphalt, which is prepared using the above-described preparation method.

[0030] In a third aspect, the present invention provides a modified bitumen roll comprising the above-prepared room-temperature emulsified modified bitumen.

[0031] Beneficial effects:

[0032] This invention involves adding a solvent to modified asphalt to reduce its viscosity, enabling it to maintain its flow dynamics at room temperature. This allows it to emulsify with soap solution at room temperature, effectively shortening the emulsification time and improving the emulsification effect. This solves the problem of poor emulsification caused by the large temperature difference between the high-temperature emulsified soap solution and the modified asphalt. The resulting emulsified modified asphalt has stable quality and produces a small and uniformly distributed particle size.

[0033] This invention raises the upper limit of the amount of modifier added to modified asphalt. Under the premise of ensuring a good emulsification effect, the amount of modifier added can reach more than 3%, or even more than 5%, thereby improving the performance of emulsified modified asphalt.

[0034] The modified asphalt of the present invention does not require high temperature to maintain the flow dynamics, and the emulsification process is carried out at room temperature, without the need to heat the modified asphalt or soap solution, effectively reducing energy consumption. The solvent of the present invention can also be recycled and reused, effectively reducing production costs. Detailed Implementation

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, specific implementation methods of the present invention are described below. Obviously, the following description is merely some embodiments of the present invention; those skilled in the art can obtain other implementation methods without creative effort.

[0036] To address the problem of significant temperature difference between modified asphalt and soap solution in conventional pre-modification followed by emulsification processes, this invention discloses a method for preparing room-temperature emulsified modified asphalt. This method maintains the flow dynamics of the modified asphalt at room temperature, thereby reducing the emulsification temperature to room temperature. The specific preparation steps are as follows:

[0037] (1) Asphalt modification: Heat the asphalt to a molten state, add the modifier, maintain a high temperature to keep the asphalt in a molten state during the stirring process, stir the asphalt and modifier to modify it, cool it after the modification is completed, then add the solvent, continue stirring while cooling to room temperature, and prepare room temperature flow-modified asphalt for use.

[0038] (2) Preparation of soap solution at room temperature: Emulsifier, pure water and stabilizer are mixed to obtain a mixed solution. The mixed solution is heated and stirred evenly. Before or after cooling, pH value of the mixed solution is adjusted using pH adjuster to obtain soap solution. The soap solution is kept at room temperature for later use.

[0039] (3) Add soap solution to the emulsifying unit, add room temperature fluid dynamic modified asphalt and mix with soap solution to emulsify;

[0040] (4) The emulsified liquid is subjected to vacuum distillation to recover the solvent, and the discharged material is room temperature emulsified modified asphalt.

[0041] In step (1), specifically, asphalt is metered into the reaction vessel, and the melting temperature is set to 160℃~180℃, for example, 165℃. After the asphalt is completely melted, SBR (polystyrene-butadiene copolymer) and SBS (styrene-butadiene-styrene block copolymer) are metered into the vessel. The vessel is stirred and dispersed at 175℃ for 2.5 hours, and then stirred at low speed while cooling down. When the temperature drops below 140℃, preferably below 120℃, an organic solvent (such as acetone) is added in a sealed environment, and the stirring speed is gradually increased while a cooling medium is introduced to rapidly cool the modified asphalt. After cooling to room temperature, the modified asphalt is kept stirred.

[0042] In step (2), specifically, emulsifier, stabilizer, and pure water are metered and added to a flask to obtain a mixed solution. The temperature is controlled below 80°C, preferably between 50°C and 60°C, to mix the solution evenly. The mixed solution is then cooled to room temperature for later use. Before or after the soap solution temperature drops to room temperature, a regulator is added to the mixed solution to adjust the pH of the mixed solution, thereby obtaining the soap solution. The use of a regulator to adjust the pH of the mixed solution before or after cooling to obtain the soap solution refers to the following two situations:

[0043] After the emulsifier, stabilizer, and pure water are thoroughly mixed, the resulting solution will be at a relatively high temperature, such as 50–60°C. First, adjust the pH of the solution using a pH adjuster, then cool it down to room temperature. Alternatively, cool the solution to room temperature first, then adjust the pH using a pH adjuster.

[0044] In step (3), modified asphalt at room temperature and soap solution at room temperature are mixed in a certain proportion and emulsified at room temperature by high-speed shearing in an emulsifier. Taking the production of 60% solids content modified emulsified asphalt as an example, modified asphalt at room temperature and soap solution at room temperature are mixed in a mass ratio of 3:2 and emulsified at room temperature by high-speed shearing in an emulsifier. It should be noted that the mixing ratio of modified asphalt and soap solution in this invention is determined according to actual production needs and is not limited to the above mixing ratio.

[0045] In step (4), the emulsified mixture is subjected to vacuum distillation at 40–60°C (e.g., 50°C) to recover the organic solvent and obtain emulsified modified asphalt. Maintaining a low temperature for vacuum distillation is to prevent demulsification at high temperatures, which would affect the performance of the emulsified modified asphalt.

[0046] Furthermore, the modified asphalt of this invention maintains its flowability at room temperature, avoiding the problem of excessive viscosity due to excessive addition of modifiers during asphalt modification, which could affect emulsification. Simultaneously, this invention can further improve the performance of the modified asphalt. For example, this invention can increase the amount of modifier added, to 3% or even 5% or more, thereby enhancing the high and low temperature performance and rubber properties of the modified asphalt, whereas conventional processes require the modifier addition amount not to exceed 3%.

[0047] The amount of modifier added in this invention can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, or more than 9%. It is easy to understand that, based on this invention, when preparing emulsified modified asphalt, the asphalt can be modified according to the performance requirements of the final product, and an appropriate amount of modifier can be added.

[0048] It should be noted that the amount of modifier added in this invention can be increased to more than 3%, but this does not mean that the preparation method of this invention must add more than 3% of modifier. Rather, it needs to be determined according to the performance requirements of the final product. For example, using the preparation method of this invention, the amount of modifier added can also be less than 3%. The preparation method of this invention improves the particle size distribution of the product, thereby improving the physical properties and storage performance of the product, and removes the limitation of emulsification process on asphalt modification in conventional processes.

[0049] Furthermore, the solvent of the present invention serves to reduce the viscosity of the modified asphalt, enabling the modified asphalt and soap solution to enter the emulsifier in fluid form at the same temperature, thereby improving the emulsification effect. The solvent refers to an organic solvent that is compatible with asphalt and has a boiling point below 90°C, such as acetone, methyl ethyl ketone, tetrahydrofuran, etc.

[0050] The mass fraction of the solvent can be less than the mass fraction of the modified asphalt, as long as the modified asphalt maintains its fluidity at room temperature after the solvent is added.

[0051] Furthermore, since the dynamic modified asphalt and soap solution in this invention can be mixed and emulsified at room temperature, the problems of foaming and demulsification that occur during the emulsification process in conventional processes are solved. The emulsification effect is better than that of conventional modified asphalt at high temperature. This invention can complete emulsification within 3 minutes, while the conventional high-temperature emulsification time is more than 10 minutes. The emulsification effect of this invention is better and the emulsification efficiency is higher.

[0052] Taking the preparation of 60% solids content emulsified modified asphalt as an example, the technical solution of the present invention will be described in detail below with specific embodiments and comparative examples.

[0053] Example 1

[0054] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 160℃, add 12 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 170℃, and after the modification is completed, cool to below 120℃, then add 120 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0055] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 50°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0056] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 2 minutes.

[0057] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0058] Example 2

[0059] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 160℃, add 16 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 170℃, and after the modification is completed, cool to below 120℃, then add 140 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0060] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 50°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0061] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 2 minutes.

[0062] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0063] Example 3

[0064] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 165℃, add 20 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 175℃, and after the modification is completed, cool to below 120℃, then add 160 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0065] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 55°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0066] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 3 minutes.

[0067] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0068] Example 4

[0069] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 165℃, add 24 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 175℃, and after the modification is completed, cool to below 120℃, then add 180 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0070] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 55°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0071] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 3 minutes.

[0072] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0073] Example 5

[0074] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 165℃, add 28 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 175℃, and after the modification is completed, cool to below 120℃, then add 200 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0075] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 55°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0076] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 3 minutes.

[0077] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0078] Example 6

[0079] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a molten state at 165℃, add 32 parts of SBS (linear) 1301 and 4 parts of SBR, stir at 175℃, and after the modification is completed, cool to below 120℃, then add 220 parts of acetone as a solvent, continue stirring while rapidly cooling to room temperature, and prepare room temperature flow-modified asphalt for use;

[0080] (2) Taking the preparation of alkaline soap solution as an example, according to the mass fraction, 12 parts of anionic emulsifier, 1.3 parts of cellulose ether stabilizer and 300 parts of pure water are added to the flask. The above raw materials are stirred for 20 minutes at 55°C until they are mixed evenly. The temperature is then reduced to room temperature. The pH value of the above mixture is adjusted to 11 using sodium hydroxide and then set aside for use.

[0081] (3) Add soap solution to the emulsifying unit. The modified asphalt and soap solution are calculated at a mass ratio of 3:2. Add room temperature fluidized modified asphalt and soap solution and mix them together for emulsification. The emulsification time is 3 minutes.

[0082] (4) The emulsified liquid is subjected to vacuum distillation at 50°C to recover acetone, and the discharged material is room temperature emulsified modified asphalt.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a completely molten state at 165℃, add 16 parts of SBS 1302 and 4 parts of SBR, stir and disperse for 2 hours and then set aside, keeping the high temperature to keep the modified asphalt in a molten state.

[0086] (2) Calculate by mass parts, add 12 parts of emulsifier JY-AFF1, 1.3 parts of stabilizer and 300 parts of pure water to the flask, and stir the above raw materials at 55℃ until they are evenly mixed. Use sodium hydroxide to adjust the pH value of the above mixture to 11 and keep it warm for later use.

[0087] (3) Use hot water to preheat the emulsifying unit, add soap solution, and then add molten modified asphalt. Keep the emulsifying unit at a high temperature to keep the modified asphalt in a molten state. The emulsification time is 10 minutes. Then add defoamer. After 2 minutes, discharge the material to the iron tank for storage to obtain emulsified modified asphalt (due to the extremely poor emulsification effect, the obtained modified asphalt is a non-uniform fluid with internal stringing. After 24 hours of storage, segregation occurs, floating matter appears on the upper surface, and sediment accumulates at the bottom, making it unusable and untestable).

[0088] Comparative Example 2

[0089] (1) Calculate by mass parts, heat 400 parts of Shell 70# asphalt to a completely molten state at 165℃, add 4 parts of SBS 1302 and 4 parts of SBR, stir and disperse for 2 hours and then set aside. Keep the high temperature to keep the modified asphalt in a molten state.

[0090] (2) Calculate by mass parts, add 12 parts of emulsifier JY-AFF1, 1.3 parts of stabilizer and 300 parts of pure water to the flask, and stir the above raw materials at 55℃ until they are evenly mixed. Use sodium hydroxide to adjust the pH value of the above mixture to 11 and keep it warm for later use.

[0091] (3) Use hot water to preheat the emulsifier, add soap solution, and then add molten modified asphalt to keep the emulsifier at a high temperature so that the modified asphalt is always in a molten state. The emulsification time is 10 minutes. Then add defoamer and discharge the material into an iron tank for storage after 2 minutes to obtain emulsified modified asphalt.

[0092] The amounts of modified asphalt components and acetone used in Examples 1-5 and Comparative Examples 1-2 are shown in Table 1.

[0093] The emulsified modified asphalts prepared in Examples 1-5 and Comparative Examples 1-2 were tested, and the test results are shown in Table 2.

[0094] Table 1. Component dosage and acetone dosage of modified asphalt in the examples and comparative examples.

[0095]

[0096] Table 2 Performance test results of the examples and comparative examples

[0097]

[0098] As shown in Table 1, the modifier addition amount (the percentage of the sum of the mass parts of SBS and SBR to the sum of the mass parts of asphalt) of the present invention is 4%, 5%, 6%, 7%, 8%, and 9% respectively. As the amount of modifier added increases, the amount of acetone used as a solvent also needs to be increased. This is because after the amount of modifier added increases, the viscosity of the modified asphalt increases, and more acetone needs to be added to maintain the flow dynamics of the modified asphalt at room temperature.

[0099] As can be seen from the test results in Table 2, the softening point, low-temperature flexibility and heat resistance of emulsified modified asphalt are significantly improved after the amount of modifier added is increased. It can be seen that the present invention improves the process of modification before emulsification, which allows the amount of modifier additive to exceed the 3% limit, effectively improving the various properties of emulsified modified asphalt.

[0100] As can be seen from the examples and comparative examples, since the comparative example uses a conventional process, the temperature difference between the modified asphalt and the soap solution is large during the emulsification process, which can lead to foaming and demulsification. Therefore, an antifoaming agent must be used in the comparative example, which increases the production cost.

[0101] The present invention also provides room temperature emulsified modified asphalt prepared using the above preparation method. The room temperature emulsified modified asphalt prepared by the present invention can be used to prepare high-performance liquid roll products.

[0102] The embodiments provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention, and the descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing room-temperature emulsified modified asphalt, characterized in that, Includes the following steps: (1) Heat the asphalt to a molten state. When the asphalt temperature reaches 160℃~180℃, add the modifiers SBR and SBS, and stir for 2~3 hours while maintaining the molten state for modification. After the modification is completed, cool down to below 140℃, then add the solvent, continue stirring and cool down rapidly until room temperature, and obtain room temperature flow-modified asphalt for use. The solvent is an organic solvent that is compatible with asphalt and has a boiling point below 90°C. (2) Prepare room temperature soap solution for later use; (3) Emulsify and mix the fluidity-modified asphalt at room temperature with soap solution at room temperature. The emulsification time is ≤3min. After the emulsification is completed, a mixture is obtained. (4) The solvent in the mixture is recovered and discharged to obtain room temperature emulsified modified asphalt.

2. The method for preparing room-temperature emulsified modified asphalt according to claim 1, characterized in that, The solvent is any one or more of acetone, butanone, and tetrahydrofuran.

3. The method for preparing room-temperature emulsified modified asphalt according to claim 1, characterized in that, In step (1), the amount of the modifier added is greater than 3% by mass fraction.

4. The method for preparing room-temperature emulsified modified asphalt according to claim 3, characterized in that, In step (1), the amount of the modifier added is greater than 5% by mass fraction.

5. The method for preparing room-temperature emulsified modified asphalt according to claim 1, characterized in that, In step (2), the preparation steps of the room temperature soap solution are as follows: Emulsifier, pure water and stabilizer are mixed and stirred at a temperature not exceeding 80°C to obtain a mixed solution. The mixed solution is cooled to room temperature. Before or after the mixed solution cools to room temperature, a pH adjuster is added to adjust the pH value of the mixed solution to the required value to obtain room temperature soap solution.

6. The method for preparing room-temperature emulsified modified asphalt according to claim 5, characterized in that, In step (2), the emulsifier is an anionic emulsifier or a cationic emulsifier; When the emulsifier is anionic, the pH adjuster is an alkaline adjuster with alkaline substances as the main component. When the emulsifier is a cationic emulsifier, the pH adjuster is an acidic adjuster with acidic substances as its main components.

7. The method for preparing room-temperature emulsified modified asphalt according to claim 6, characterized in that, When the emulsifier is an anionic emulsifier, the pH adjuster is any one of sodium hydroxide, sodium carbonate, sodium bicarbonate or potassium carbonate; When the emulsifier is a cationic emulsifier, the pH adjuster is any one of hydrochloric acid, phosphoric acid, tartaric acid, lactic acid, or acetic acid.

8. A room-temperature emulsified modified asphalt, characterized in that, It is prepared by the method for preparing room temperature emulsified modified asphalt as described in any one of claims 1-7.

9. A modified bitumen roll material, characterized in that, It includes the room-temperature emulsified modified asphalt as described in claim 8.

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