Self-adhesive bituminous waterproofing membrane, method for its production and use

Abstract

The application provides a self-adhesive asphalt waterproof roll, a preparation method and application thereof. The self-adhesive asphalt waterproof roll comprises, from inside to outside, an asphalt bonding layer and a weather-resistant layer arranged in sequence. The asphalt bonding layer comprises a base asphalt component, a maleic anhydride modified styrene-butadiene-styrene block copolymer and an ionic liquid. The base asphalt component comprises a matrix asphalt, a softening agent, a styrene-butadiene-styrene block copolymer, a polystyrene butadiene copolymer, a tackifying resin and an inorganic filler. The ionic liquid is a compound of one of methyltrioctylammonium bis(trifluoromethylsulfonyl) imide and N-octylpyridine bis(trifluoromethylsulfonyl) imide and 1-allyl-3-methylimidazolium chloride. The weather-resistant layer comprises a fluorocarbon resin layer and a polyester / polyolefin layer.

Description

Technical Field

[0001] This application relates to the field of asphalt technology, specifically to a self-adhesive asphalt waterproof membrane, its preparation method, and its application. Background Technology

[0002] The problem of roof leakage in old buildings is becoming increasingly prominent, seriously affecting building safety and functionality. Currently, a large number of residential, industrial, and public buildings constructed in the last century commonly suffer from roof leakage due to factors such as aging waterproofing materials, structural deformation, and initial construction defects. The leakage problem is further aggravated during the rainy season and extreme weather, causing not only indoor mold and damage to facilities and equipment, but also posing a risk of corroding the building structure and causing structural safety hazards. Moreover, the repair scenarios are diverse, covering flat roofs, metal roofs, and various types of buildings including industrial, commercial, and residential buildings.

[0003] Currently, commonly used roof waterproofing repair materials all have limitations: elastomeric modified bitumen waterproofing membranes (such as styrene-butadiene-styrene block copolymer modified bitumen membranes) require hot-melt application, posing a high safety risk for open flame operations on old buildings; thermoplastic polyolefin waterproofing membranes have good weather resistance, but are difficult to fully adhere to the substrate for secondary repairs, easily leading to water seepage; bitumen-based and polyurethane coatings are only suitable for local crack repairs and lack long-term weather resistance; although weather-resistant self-adhesive bitumen waterproofing membranes can be cold-applied and fully adhered to prevent water seepage, they are prone to adhesion failure and secondary leakage in complex conditions such as damp substrates and substrates with residual aged waterproofing membrane debris. Although performance can be compensated for by coating-membrane composite methods, this has the disadvantages of high cost and difficulty in subsequent repairs. Summary of the Invention

[0004] In view of this, in order to at least partially solve at least one of the aforementioned technical problems, this application provides a self-adhesive bitumen waterproof membrane, its preparation method, and its application.

[0005] To achieve the above objectives, the technical solution of this application is as follows.

[0006] According to one embodiment of this application, a self-adhesive bitumen waterproof membrane is provided, which includes, from the inside out, a bitumen adhesive layer and a weather-resistant layer arranged sequentially.

[0007] The asphalt bonding layer comprises: base asphalt components, maleic anhydride-modified styrene-butadiene-styrene block copolymer, and ionic liquid.

[0008] The base asphalt components include: base asphalt, softener, styrene-butadiene-styrene block copolymer, polystyrene-butadiene copolymer, tackifying resin, and inorganic filler.

[0009] The ionic liquid is a compound of one of methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide with 1-allyl-3-methylimidazolium chloride.

[0010] The weather-resistant layer includes a fluorocarbon resin layer and a polyester / polyolefin layer.

[0011] According to another embodiment of this application, a method for preparing the above-mentioned self-adhesive bitumen waterproof membrane is provided, comprising: melting and mixing a base bitumen component and a maleic anhydride-modified styrene-butadiene-styrene block copolymer, adding an ionic liquid, and stirring and dispersing to obtain a target modified bitumen; coating the target modified bitumen onto the surface of the fluorocarbon resin layer of the weather-resistant layer to form a bitumen sheet; and passing the bitumen sheet through an electric field of 10-50 kV / m at a temperature of 50-70°C to obtain a self-adhesive bitumen waterproof membrane.

[0012] According to another embodiment of this application, an application of the above-mentioned self-adhesive bitumen waterproof membrane in waterproof repair of construction surfaces is provided.

[0013] According to embodiments of this application, the self-adhesive bitumen waterproof membrane adopts a composite structure of bitumen adhesive layer and weather-resistant layer, achieving synergistic functions of interface bonding, waterproof sealing, structural reinforcement, and long-term weather resistance. The bitumen adhesive layer undertakes waterproof bonding and self-healing functions; the weather-resistant layer adopts a composite structure of fluorocarbon resin layer and polyester / polyolefin layer, which has good anti-aging, corrosion resistance, and mechanical reinforcement effects, and can meet the requirements of long-term exposed service. The bitumen adhesive layer is synergistically modified by maleic anhydride-modified styrene-butadiene-styrene block copolymer (SBS-g-MAH) and two-component compound ionic liquid. SBS-g-MAH improves the cohesive strength of the system while forming stable bonds to the ionic liquid, preventing component leaching; the hydrophobic and hydrophilic ionic liquid compound system can be adapted to complex repair conditions such as old oily bitumen substrates, damp substrates, and substrates with broken polyethylene (PE) film, achieving stable interface bonding. In addition, ionic liquids can form a reversible secondary bond network within the asphalt system, significantly improving the self-healing performance of the roll material and effectively resisting cracking and leakage in the base layer; the base asphalt components and functional modifiers have excellent compatibility, balancing system stability and raw material costs, and are suitable for industrial mass production. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments.

[0015] In the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments of this application. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0016] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.

[0017] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0018] Because self-adhesive modified bitumen waterproof membranes can be applied using a cold-applied process, eliminating the need for open flames, and can adhere fully to the substrate, effectively preventing water seepage, they have gradually become the primary material for waterproofing repairs and upgrades of roofs in older residential areas. Furthermore, their application in exposed environments has been expanded when combined with weather-resistant surface layers. However, existing weather-resistant self-adhesive bitumen waterproof membranes still have several technical shortcomings in their application to repairing older roofs: the substrate conditions are complex, there are significant differences in the properties of new and old materials, and they are often accompanied by floating dust, debris, residual polyethylene (PE) film fragments, and substrate cracking. These issues make it easy for the self-adhesive modified bitumen waterproof membrane to leak secondary due to poor interfacial adhesion and shrinkage mismatch between the membrane and the substrate.

[0019] Although self-healing, self-adhesive modified bitumen waterproof membranes adapted to complex environments and long-term durability requirements have been developed, their self-healing function relies solely on the capillary flow effect and surface energy of the bitumen components to passively fill microcracks. This cannot solve the interfacial bonding problem under complex substrates. Debris such as floating dust, residual film layers, and bitumen debris will still severely weaken the interfacial bonding effect of the membrane, making it impossible to simultaneously achieve excellent weather resistance, adaptability to complex substrates, and self-healing performance.

[0020] In realizing the concept of this application, it was discovered that simply adjusting the conventional modified components of the asphalt system cannot simultaneously solve the compatibility problem between asphalt membranes and complex polar substrates, nor can it address the bottleneck of the inability to synergistically improve the system's cohesive strength, interfacial adhesion performance, and self-healing properties. Although the interfacial polarity compatibility can be improved by introducing ionic liquids, the disordered dispersion of ionic liquids in the asphalt system prevents them from fully exerting their interfacial adhesion effect, easily leading to a decrease in the cohesive strength of the asphalt system. Therefore, there is an urgent need to provide a self-adhesive modified asphalt waterproof membrane that, while ensuring the membrane's excellent weather resistance, achieves a synergistic improvement in the system's cohesive strength, interfacial adhesion performance on complex substrates, and self-healing properties.

[0021] Based on this, this application proposes a self-adhesive asphalt waterproof membrane, its preparation method, and its application. A modified asphalt bonding system is constructed using a base asphalt component with a specific mass ratio, maleic anhydride-modified styrene-butadiene-styrene block copolymer (SBS-g-MAH), and a two-component compound ionic liquid. The bonding and binding effect of SBS-g-MAH on the ionic liquid ensures the cohesive strength and structural stability of the asphalt system. Simultaneously, a weather-resistant layer with fluorocarbon resin as its core is matched to ensure the long-term exposed weather resistance of the membrane. Furthermore, through a pre-cooling followed by low-temperature electric field directional treatment preparation process, the orderly arrangement and interfacial enrichment of the anions and cations of the ionic liquid are precisely controlled. Without damaging the asphalt matrix, this simultaneously improves the interfacial bonding performance and self-healing ability of the membrane under complex repair conditions such as damp surfaces, broken PE film surfaces, and old rubber asphalt surfaces. No additional composite asphalt coating is required, significantly reducing project costs and subsequent repair difficulty, and adapting to all scenarios of waterproofing repair for old roofs.

[0022] Specifically, according to one aspect of this application, a self-adhesive bitumen waterproof membrane is provided, which includes, from the inside out, a bitumen adhesive layer and a weather-resistant layer arranged sequentially.

[0023] The asphalt bonding layer comprises: base asphalt components, maleic anhydride-modified styrene-butadiene-styrene block copolymer, and ionic liquid.

[0024] The base asphalt components include: base asphalt, softener, styrene-butadiene-styrene block copolymer, polystyrene-butadiene copolymer, tackifying resin, and inorganic filler.

[0025] The ionic liquid is a compound of one of methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide with 1-allyl-3-methylimidazolium chloride.

[0026] The weather-resistant layer includes a fluorocarbon resin layer and a polyester / polyolefin layer.

[0027] According to embodiments of this application, the self-adhesive bitumen waterproof membrane adopts a composite structure of a bitumen adhesive layer and a weather-resistant layer, achieving synergistic functions of interfacial bonding, waterproof sealing, structural reinforcement, and long-term weather resistance. The bitumen adhesive layer, as the main functional layer, directly contacts the substrate to be constructed, undertaking the functions of interfacial bonding, waterproof sealing, and micro-crack self-healing. Combined with the weather-resistant layer, it effectively prevents interlayer delamination and water seepage. The weather-resistant layer adopts a composite structure of a fluorocarbon resin layer and a polyester / polyolefin layer. The high-energy carbon-fluorine (CF) bonds in the fluorocarbon resin endow it with excellent resistance to UV aging, acid and alkali corrosion, and self-cleaning properties, effectively resisting external environmental erosion. The polyester / polyolefin layer, as a reinforcing skeleton, improves the tensile strength, tear resistance, and dimensional stability of the membrane.

[0028] The asphalt bonding layer utilizes a synergistic modification design of maleic anhydride-modified styrene-butadiene-styrene block copolymer (SBS-g-MAH) and a compounded ionic liquid to effectively resolve the contradiction between improved interfacial adhesion and decreased system cohesive strength. On one hand, SBS-g-MAH can increase the crosslinking density and cohesive strength of the asphalt system, while simultaneously forming stable bonds to the ionic liquid, thus solving the problems of decreased system cohesive strength and component analysis caused by adding the ionic liquid alone. On the other hand, this application employs a two-component system of hydrophobic ionic liquid (methyltrioctylammonium bis(trifluoromethanesulfonyl)imide or N-octylpyridine bis(trifluoromethanesulfonyl)imide) and hydrophilic ionic liquid (1-allyl-3-methylimidazolium chloride). The liquid has a long alkyl chain hydrophobic structure, exhibiting good compatibility and interfacial bonding ability with oily substrates such as asphalt organic molecules, residual rubber asphalt on old roofs, and aged asphalt. It can form a relatively stable miscible entanglement structure with the interface between new and old asphalt. The hydrophilic ionic liquid has highly polar imidazole cations and chloride ions that can form hydrogen bonds, possessing good hydrophilicity and polar compatibility. It can stably bond with water molecules and polar groups on damp substrates through hydrogen bonding. At the same time, it can penetrate the gaps of residual broken PE film with its low viscosity and good migration to form effective adhesion with the underlying asphalt substrate. The combination of the two ionic liquids can be adapted to complex maintenance conditions such as old oily asphalt substrates, damp substrates, and substrates with broken PE film, achieving relatively stable interfacial adhesion.

[0029] Meanwhile, ionic liquids, as molten salts that are liquid at or near room temperature, are formed by organic cations and inorganic / organic anions bonded together by ionic bonds. In asphalt systems, they can form a reversible secondary bond network through ion-dipole interactions, hydrogen bonds, and ion aggregation, effectively improving the self-healing properties of modified asphalt. At room temperature, ionic liquids have a low melting point and good viscosity. As the ambient temperature rises, self-adhesive asphalt waterproof membranes can melt relatively quickly. The free anions and cations can reduce the surface energy of the bonding interface through electrostatic interaction, further enhancing the adhesion and repair effect of the membrane to the substrate, and effectively resisting the leakage risks caused by cracking of the base layer.

[0030] In addition, the base asphalt component in the asphalt binder has good compatibility with functional modifiers such as SBS-g-MAH and ionic liquids, which can simultaneously improve the processing stability and dimensional stability of the modified asphalt system, while taking into account the cost of raw materials and meeting the needs of industrialized mass production.

[0031] According to embodiments of this application, the ratio of one of methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide to 1-allyl-3-methylimidazolium chloride is 8:2 to 9:1, for example, 8:2, 8.8:1.2, 8.5:1.5, 9:1, etc. Through the synergistic complementarity of the two ionic liquids, charge balance, functional matching, and synergistic migration activity of the anions and cations in the compound system are achieved, thereby balancing the cohesive strength, adhesive properties, and self-healing properties of the asphalt system.

[0032] First, all the aforementioned ionic liquids are molten salt structures in which cations and anions are bonded by ionic bonds. In methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide, the corresponding cations are hydrophobic long-chain alkyl-substituted quaternary ammonium or pyridine cations, and the anions are weakly coordinated, low-hydrophilic bis(trifluoromethanesulfonyl)imide anions. These anions exhibit strong bonding with organic molecules in the base asphalt components and the substrate, thereby enhancing the cohesive strength and creep recovery performance of the modified asphalt and ensuring the self-healing ability and adhesive compatibility of the self-adhesive asphalt waterproof membrane. In 1-allyl-3-methylimidazolium chloride, the cation is an imidazolium cation with strong polarity and hydrophilicity, and the anion is a chloride ion with strong coordination and easy hydrogen bonding. It can bond with water molecules on the substrate through hydrogen bonding, thus improving adhesion to the substrate. By combining various ionic liquids in appropriate proportions, the functional balance of cations and anions in the system can be achieved, while ensuring the charge balance between total cations and total anions, thus avoiding a decrease in system stability caused by charge imbalance.

[0033] Furthermore, this ratio range allows for matching the number of polar grafting sites between the compounded ionic liquid and SBS-g-MAH in the system. The anhydride groups of SBS-g-MAH can form hydrogen bonds and ionic bonds with the cations in the ionic liquid, achieving appropriate binding of the ionic liquid. If the compounding ratio of the two ionic liquids is too high or too low, it will break the matching relationship between SBS-g-MAH and the ionic liquid, leading to an imbalance in its binding effect on the ionic liquid. It will also cause an imbalance in the function and charge balance of anions and cations in the system, reducing the overall stability of the modified asphalt. Ultimately, this results in the inability to simultaneously achieve the cohesive strength, adhesion performance, and self-healing performance of the self-adhesive asphalt waterproof membrane.

[0034] According to embodiments of this application, the asphalt bonding layer comprises 100% by mass, including: 95%~98% base asphalt component; 2~4% maleic anhydride-modified styrene-butadiene-styrene block copolymer; and 0.2%~1.0% ionic liquid. At this mass percentage ratio, the components in the asphalt bonding layer form a synergistic and complementary modification system, which can regulate and balance the basic viscoelastic properties, cohesive strength, adhesion to complex substrates, and self-healing properties of the bonding layer, while ensuring that the modification effects of each component are fully utilized without performance antagonism.

[0035] According to some specific embodiments, the mass percentage of the base asphalt component can be 95%, 96%, 97%, 98%, etc. As the main body of the asphalt binder, the base asphalt component ensures the basic adhesion, viscoelasticity, and formability of the asphalt binder, preventing other components from damaging the asphalt matrix and providing a stable base for subsequent optimization and modification. The mass percentage of maleic anhydride-modified styrene-butadiene-styrene block copolymer can be 2%, 2.5%, 3%, 3.5%, 4%, etc., which can improve the cohesive strength, deformation resistance, and structural stability of the asphalt binder. Furthermore, through the formation of hydrogen bonds and ionic bonds between the anhydride groups and the cations of the ionic liquid, it achieves appropriate binding of the ionic liquid. Its proportion range matches the mass percentage of the ionic liquid, avoiding insufficient binding leading to ionic liquid loss or excessive binding restricting the function of the ionic liquid. The mass percentage of ionic liquid can be 0.2%, 0.3%, 0.5%, 0.7%, 0.8%, 1.0%, etc. It reduces the surface energy of the bonding interface through the electrostatic interaction of anions and cations in the system, and improves the adhesion to complex substrates such as damp surfaces and surfaces with residual impurities. At the same time, it endows the asphalt bonding layer with good self-healing ability by utilizing secondary bond interactions such as ion-dipole interactions, hydrogen bonds, and ion aggregation. This proportion ensures the modification effect of ionic liquid while avoiding excessive addition that may affect the cohesive strength of the asphalt bonding layer and its compatibility with the base asphalt components.

[0036] According to the embodiments of this application, the components in the base asphalt component, by weight, include: 45-55 parts of base asphalt; 10-15 parts of softening oil; 3-5 parts of styrene-butadiene-styrene block copolymer; 3-5 parts of polystyrene-butadiene copolymer; 2-5 parts of tackifying resin; and 20-40 parts of inorganic filler.

[0037] According to some specific embodiments, the base asphalt can be, for example, 45 parts, 47 parts, 50 parts, 53 parts, 55 parts, etc. The base asphalt, as the main substrate of the base asphalt component, provides basic adhesion and waterproofing properties. The softening oil can be, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc., which can adjust the viscoelastic properties of the base asphalt component and improve its application performance. The styrene-butadiene-styrene block copolymer can be, for example, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc. The polystyrene-butadiene copolymer can be in quantities of 3, 3.5, 4, 4.5, or 5 parts, which together enhance the elasticity, deformation resistance, and cohesive strength of the base asphalt component. The tackifying resin can be in quantities of 2, 3, 4, or 5 parts, further improving the interfacial adhesion of the base asphalt component and strengthening its compatibility with various types of substrates. The inorganic filler can be in quantities of 20, 25, 30, 35, or 40 parts, optimizing the system's formability and structural stability while reasonably controlling raw material costs. The raw materials in the base asphalt component form a synergistic and complementary system, possessing good adhesion, viscoelasticity, structural stability, and construction compatibility. This lays a stable foundation for the subsequent application of maleic anhydride-modified styrene-butadiene-styrene block copolymer and ionic liquid-modified components, while also meeting the requirements for the use and preparation of self-adhesive asphalt waterproof membranes.

[0038] According to the embodiments of this application, the base asphalt is at least one of 70# petroleum asphalt and 90# petroleum asphalt.

[0039] Styrene-butadiene-styrene block copolymer (SBS) has a linear structure with a number average molecular weight of 100,000 to 140,000. The linear structure makes it easier to be compatible and dispersed with the matrix asphalt molecules. Linear SBS in this molecular weight range has good elasticity, cohesive strength and resistance to deformation, which can effectively improve the viscoelasticity, aging resistance and structural stability of the base asphalt components.

[0040] The polystyrene-butadiene copolymer is either solution-polymerized or emulsion-polymerized. Both types are well-compatible with base asphalt, with a number-average molecular weight of 80,000 to 180,000. This molecular weight range can balance flexibility and dispersibility. It works synergistically with linear SBS to further enhance the flexibility, cohesive strength, and crack resistance of the base asphalt components.

[0041] Maleic anhydride-modified styrene-butadiene-styrene block copolymer (SBS-g-MAH) is obtained by grafting a linear styrene-butadiene-styrene block copolymer with linear maleic anhydride. The linear structure of the styrene-butadiene-styrene block copolymer facilitates uniform grafting. The grafting rate of SBS-g-MAH is 0.5%~1.0%, which balances the compatibility of SBS-g-MAH with the base asphalt and the number of polar anhydride sites. If the grafting rate is too low (below 0.5%), there may be insufficient polar sites, which cannot effectively form bonds with the cations in the ionic liquid to bind the ionic liquid; if the grafting rate is too high (above 1.0%), it may reduce its compatibility with the base asphalt, resulting in uneven dispersion of the base asphalt components.

[0042] The softening oil is at least one of the following: triple-strength oil, double-strength oil, aromatic oil, and naphthenic oil; the tackifying resin is at least one of the following: petroleum resin, rosin resin, and terpene resin; the inorganic filler is calcium powder of 200-400 mesh. The specific types and proportions of each component can be flexibly selected according to the actual construction conditions and performance requirements to suit different application scenarios.

[0043] According to embodiments of this application, the fluorocarbon resin layer is obtained by casting at least one of polyvinylidene fluoride, polyvinyl fluoride, and vinyl fluoride-vinyl ether copolymer. The aforementioned fluorocarbon resin contains carbon-fluorine (CF) bonds with high bond energies, up to 485 KJ / mol, making it difficult for the fluorocarbon resin to break under external factors such as heat and ultraviolet radiation. This gives the film layer good resistance and can effectively resist environmental corrosion such as ultraviolet radiation, acid rain, and salt spray. The casting process can produce a fluorocarbon resin film with uniform thickness and a dense structure, further blocking the intrusion of external media. Furthermore, the surface of the fluorocarbon resin layer is hydrophobic, allowing for self-cleaning through rainwater washing, reducing the accumulation of impurities and corrosive media, and further extending the service life and weather resistance of the film layer.

[0044] The polyester / polyolefin layer is a polyethylene terephthalate film or a polyethylene film. These films have high mechanical strength and toughness, which can provide support for the fluorocarbon resin layer. At the same time, they have good compatibility with the fluorocarbon resin layer, and the raw materials are readily available and suitable for the industrial production of self-adhesive bitumen waterproof membranes.

[0045] According to the embodiments of this application, the thickness of the self-adhesive bitumen waterproof membrane is 1.0~2.0 mm, for example, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, etc., and the thickness of the weather-resistant layer is 100μm~200μm, for example, 100μm, 120μm, 150μm, 180μm, 200μm, etc. The thickness of the fluorocarbon resin layer is 20~35μm, for example, 20μm, 25μm, 30μm, 35μm, etc. The matching and coordinated thickness of each layer ensures both the overall waterproof performance of the membrane and the weather-resistant protection effect of the fluorocarbon layer, while avoiding problems such as failure due to excessively thin single layers, reduced flexibility due to excessively thick layers, or poor interlayer adhesion. In actual self-adhesive bitumen waterproof membrane applications, the specific thickness parameters of each layer can be adjusted according to the roof waterproofing requirements, the usage environment, and the conditions of the construction substrate.

[0046] According to another embodiment of this application, a method for preparing the above-mentioned self-adhesive bitumen waterproof membrane is provided, comprising: melting and mixing a base bitumen component and a maleic anhydride-modified styrene-butadiene-styrene block copolymer, adding an ionic liquid, and stirring and dispersing to obtain a target modified bitumen; coating the target modified bitumen onto the surface of the fluorocarbon resin layer of the weather-resistant layer to form a bitumen sheet; and passing the bitumen sheet through an electric field of 10-50 kV / m at a temperature of 50-70°C to obtain a self-adhesive bitumen waterproof membrane.

[0047] In some specific embodiments, the process can be carried out at temperatures of 50℃, 55℃, 60℃, 65℃, and 70℃. This temperature range allows the asphalt sheet to maintain suitable viscoelasticity, reduces ion migration resistance, and does not cause thermal aging of the asphalt. The asphalt sheet can be subjected to electric fields of 10kV / m, 20kV / m, 30kV / m, 40kV / m, and 50kV / m to obtain a self-adhesive asphalt waterproof membrane. The electric field strength can achieve the orderly directional arrangement of anions and cations in the asphalt sheet without breaking down the material. After electric field orientation treatment, the interfacial adhesion, self-healing efficiency, and system stability can be improved.

[0048] According to the embodiments of this application, the preparation method of the self-adhesive bitumen waterproof membrane is characterized by mild and highly controllable process conditions, which enables the base bitumen components, SBS-g-MAH, and ionic liquid to be fully melted and dispersed, ensuring the uniformity and stability of the target modified bitumen system. By directly coating the target modified bitumen onto the surface of the weather-resistant layer, the interlayer bonding strength can be improved. Oriented treatment with an electric field at a suitable temperature can avoid asphalt thermal aging and achieve the orderly arrangement of anions and cations in the ionic liquid, significantly improving the interfacial adhesion performance, self-healing efficiency, and stability of the membrane. The resulting self-adhesive bitumen waterproof membrane can adapt to various complex maintenance conditions and has both good waterproof and weather-resistant properties.

[0049] According to the embodiments of this application, the coating temperature is 160~180℃, for example, it can be 160℃, 165℃, 170℃, 175℃, 180℃, etc., which can ensure that the target modified asphalt has suitable melt fluidity, so that the coating is uniform and dense, while avoiding excessive temperature from causing thermal aging of the target modified asphalt and weather-resistant layer, and improving the interlayer bonding stability.

[0050] The time for the asphalt sheet to pass through the electric field is 0.5 s to 1 s, for example, 0.5 s, 0.6 s, 0.7 s, 0.8 s, 0.9 s, 1 s, etc. The appropriate time can ensure that the anions and cations in the ionic liquid are fully oriented, thereby optimizing the interfacial adhesion and self-healing performance, while avoiding excessive processing time that may affect production efficiency or damage the roll structure.

[0051] The winding temperature of self-adhesive bitumen waterproof membrane is 20~35℃, for example, it can be 20℃, 25℃, 30℃, 35℃, etc. This allows the self-adhesive bitumen waterproof membrane to cool and set fully, avoiding problems such as adhesion and deformation when winding at high temperatures, and ensuring the dimensional stability and appearance flatness of the membrane.

[0052] According to another embodiment of this application, an application of the above-mentioned self-adhesive bitumen waterproof membrane in waterproof repair of construction surfaces is provided.

[0053] According to the embodiments of this application, when the self-adhesive bitumen waterproof membrane of this application is applied to the waterproof repair of the construction surface, it can be adapted to complex repair conditions such as damp base surface, dusty base surface, and base surface with aging film / bitumen debris. It does not require additional coating composite construction, adheres firmly to the construction surface, has strong self-healing and weather resistance, can effectively reduce the probability of secondary leakage, is easy to construct, has high repair efficiency, and the waterproof repair effect is stable and long-lasting.

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments. Unless otherwise specified, all methods described in the embodiments are conventional and can be performed according to the techniques or conditions described in the literature or the product manual.

[0055] Example 1

[0056] Embodiment 1 of this application provides a self-adhesive bitumen waterproof membrane. The preparation method of this self-adhesive bitumen waterproof membrane is as follows.

[0057] After melting 70# petroleum asphalt and softening oil, linear styrene-butadiene-styrene block copolymer (linear SBS), solution-polymerized polystyrene-butadiene copolymer (solution-polymerized SBR), maleic anhydride-modified styrene-butadiene-styrene block copolymer (SBS-g-MAH), and tackifying resin were added and stirred to disperse. Then, 200-mesh calcium powder was added and stirring continued until homogeneous. Finally, ionic liquid was added and stirred to disperse for 60 minutes to obtain the target modified asphalt. The base asphalt components (70# petroleum asphalt, softening oil, linear SBS, solution-polymerized SBR, tackifying resin, and 200-mesh calcium powder) accounted for 97% by mass; SBS-g-MAH accounted for 2.5% by mass; and the ionic liquid accounted for 0.5% by mass. The ionic liquid was obtained by compounding methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride in a mass ratio of 9:1.

[0058] At a temperature of 160℃, the target modified asphalt is coated onto the surface of the fluorocarbon resin layer of the weather-resistant layer using a scraping device to form an asphalt bonding layer. Silicone oil isolating material is then adhered to the asphalt bonding layer to obtain asphalt sheet.

[0059] The asphalt sheet was cooled to 50°C by air cooling, then subjected to an electric field of 50kV / m for 0.5s, and then cooled to below 35°C by air cooling again to obtain a self-adhesive asphalt waterproof membrane.

[0060] Example 2

[0061] Example 2 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 2.8% and the mass percentage of ionic liquid is 0.2%.

[0062] Example 3

[0063] Example 3 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 2.3% and the mass percentage of ionic liquid is 0.7%.

[0064] Example 4

[0065] Example 4 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 2.0% and the mass percentage of ionic liquid is 1.0%.

[0066] Comparative Example 1

[0067] Comparative Example 1 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 3.0% and the mass percentage of ionic liquid is 0%.

[0068] Comparative Example 2

[0069] Comparative Example 2 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 1.5% and the mass percentage of ionic liquid is 1.5%.

[0070] Comparative Example 3

[0071] Comparative Example 3 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 1.0% and the mass percentage of ionic liquid is 2.0%.

[0072] Comparative Example 4

[0073] Comparative Example 1 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between this self-adhesive bitumen waterproof membrane and Example 1 is that the mass percentage of SBS-g-MAH is 0% and the mass percentage of ionic liquid is 3.0%.

[0074] The adhesion performance of the self-adhesive bitumen waterproof membranes in the embodiments and comparative examples of this application was evaluated by peel strength against rubber asphalt substrates, damp substrates, dusty substrates, and substrates with broken polyethylene (PE) film. The self-healing performance was evaluated by creep recovery time and recovery rate. The specific test methods are as follows.

[0075] The bonding performance test of self-adhesive bitumen waterproof membrane was conducted according to GB 23441-2009 "Self-adhesive Polymer Modified Bitumen Waterproof Membrane": Under (23±2)℃ conditions, membrane specimens were adhered to different substrates according to GB / T 328.20, with the adhesive surface dimensions being 50mm×75mm. The specimens were repeatedly rolled three times with a 2kg roller with a width of (50~60)mm, and then left to stand for 24 hours after bonding. One end of the substrate was bent 180° to the same end of the membrane, and then clamped into fixtures for testing. The peel strength (unit: N / mm) was calculated using the maximum force, and the arithmetic mean of the results from five specimens was taken as the test result.

[0076] The rubber asphalt substrate is: a styrene-butadiene-styrene block copolymer (SBS) modified bitumen waterproof membrane that has aged after exposure to the elements, with a softening point of 100~140℃ and a penetration of 15~45dmm; the damp substrate is: a surface with visible dampness or a 1m... 2After the roll material is laid flat on the base layer for 3-4 hours, there are obvious water droplets on the lower surface of the roll material, with a moisture content of more than 9%; the definition of the dusty base surface refers to GB 23457-2025 "Pre-laid Waterproof Roll Material": fine sand with a mud content of no more than 2% and a maximum particle size of no more than 0.20 mm is evenly spread on the flat pre-laid reverse adhesive surface after the isolation material has been removed, and left to stand for (168±2) hours. Each specimen is rinsed with water for 2 minutes to remove the fine sand on the surface, and then wiped or sucked dry to obtain the dusty base surface; the base surface with broken polyethylene (PE) film on the surface is: based on an unaged PE film with a thickness of about 10μm, the PE film has been exposed and aged, and has shown irregular weathering, powdering and breakage and detachment, forming broken fragments with no strength and small residual amount, which are attached to the rubber asphalt base surface.

[0077] Table 1 shows the performance test data of self-adhesive bitumen waterproof membranes with different amounts of SBS-g-MAH and ionic liquid added in Examples 1 to 4 and Comparative Examples 1 to 4.

[0078] Table 1

[0079]

[0080] As shown in Table 1, the bond strength between the self-adhesive bitumen waterproof membrane and the rubber bitumen substrate decreases with decreasing SBS-g-MAH content and increasing ionic liquid content. This is because the rubber bitumen substrate is an oily interface with good compatibility with the self-adhesive bitumen waterproof membrane, and there is no obvious physical barrier to interfacial bonding. In this case, the peel strength is mainly determined by the cohesive strength of the bitumen adhesive layer. As a reactive elastic modifier, SBS-g-MAH can form chemical bonds with the matrix bitumen components through grafted anhydride groups, thereby improving the cohesive strength of the bitumen adhesive layer. The effect of SBS-g-MAH on cohesive strength and interfacial adhesion is higher than that of ionic liquid. As the proportion of SBS-g-MAH decreases and the proportion of ionic liquid increases, the cohesive strength of the bitumen adhesive layer gradually decreases, thus reducing the bond strength with the rubber bitumen substrate. The peel strength of Examples 1 to 4 of this application is relatively stable, only slightly lower than that of Comparative Example 1 without added ionic liquid, and far superior to that of Comparative Examples 2 to 4 with excessive ionic liquid. This indicates that the self-adhesive bitumen waterproof membrane of this application can retain good cohesive strength and conventional substrate adhesion performance while taking into account other properties.

[0081] In Examples 1-4 and Comparative Examples 1-4 of this application, the bonding strength between all self-adhesive bitumen waterproof membranes and the dusty substrate is relatively low, with only a slight improvement observed when the ionic liquid content is ≥0.7%. This is because the self-adhesive bitumen waterproof membranes are primarily bonded through chemical forces such as hydrogen bonds and ionic bonds formed between the ionic liquid and the substrate. The dust layer, however, forms a continuous physical barrier, blocking direct contact between the self-adhesive bitumen waterproof membrane and the substrate, thus preventing the effective formation of interfacial chemical forces. Only when the ionic liquid content is high can a small amount of ionic liquid penetrate through the dust gaps and form a weak bond with the substrate. Therefore, the bonding strength increases slightly with increasing ionic liquid content, but the overall strength remains low.

[0082] In Examples 1-4 and Comparative Examples 1-4 of this application, the peel strength of all self-adhesive bitumen waterproof membranes to damp substrates showed a trend of first increasing and then decreasing with the increase of ionic liquid addition. In Examples 1 and 3 of this application, the peel strength reached 1.7 N / mm, which is better than Comparative Example 1 (1.3 N / mm) without ionic liquid addition. In Comparative Examples 2-4, where the ionic liquid exceeded the upper limit of this application, the peel strength was about 1.3-1.4 N / mm. The main reason is that water molecules on a damp substrate are highly polar media, which can activate the polar imidazole cations and chloride ions in the ionic liquid, promoting their full migration to the interface. Through hydrogen bonding, they bond with water molecules and polar groups on the substrate, improving the adhesion performance with the damp interface. Therefore, as the amount of ionic liquid added increases, the adhesion strength initially shows an upward trend. However, when the amount of ionic liquid added exceeds 1.0%, the proportion of SBS-g-MAH in the system simultaneously drops below 2.0%, and the number of anhydride polar grafting sites is insufficient to effectively bind the excessive ionic liquid, resulting in a significant decrease in the cohesive strength of the asphalt system itself, ultimately leading to a reduction in adhesion strength.

[0083] In Examples 1-4 and Comparative Examples 1-4 of this application, the peel strength between all self-adhesive bitumen waterproof membranes and the substrate with shredded PE film showed a continuous upward trend with increasing ionic liquid addition. The peel strength between the self-adhesive bitumen waterproof membranes and the substrate with shredded PE film in these examples was superior to that in Comparative Example 1 without added ionic liquid. The shredded PE film is a non-polar inert material and cannot form an effective bond with the self-adhesive bitumen itself. Its physical barrier effect on the interface is similar to that of floating dust, therefore its overall trend is similar to that of the dust-covered substrate. However, there are obvious gaps between the shredded PE films, allowing the ionic liquid to fully penetrate to the underlying substrate and form stable hydrogen and ionic bonds, thus achieving effective interfacial adhesion. Therefore, with increasing ionic liquid addition, the peel strength between the self-adhesive bitumen waterproof membranes and the substrate with shredded PE film shows a continuous upward trend.

[0084] Furthermore, with increasing ionic liquid addition, the 30s creep recovery rate of all self-adhesive bitumen waterproof membranes in Examples 1-4 and Comparative Examples 1-4 of this application showed an upward trend. The recovery rate of Comparative Example 1 without added ionic liquid was 96%, while that of Examples 1-4 of this application reached 97%-98%. Comparative Examples 2-4 with excessive ionic liquid could further increase the recovery rate to 99%. The main reason is that ionic liquid is a molten salt system composed of anions and cations, with abundant reversible secondary bonds such as ion-dipole interactions, hydrogen bonds, and ion aggregation between molecules. When the self-adhesive bitumen waterproof membrane undergoes creep deformation under external force, these reversible secondary bonds can achieve rapid reset of the molecular chain through breakage and reconstruction. At the same time, ionic liquid can improve the molecular chain fluidity of the self-adhesive bitumen waterproof membrane and enhance its entropy elastic recovery ability. Therefore, with increasing ionic liquid addition, the creep recovery rate increases, and the self-healing performance is optimized.

[0085] In summary, the self-adhesive bitumen waterproof membranes of Examples 1-4 of this application achieve a comprehensive balance of various properties by adjusting the mass percentages of the matrix bitumen component, SBS-g-MAH, and ionic liquid. They retain good cohesive strength and adhesion to rubber-asphalt substrates while improving adhesion to complex substrates such as damp substrates and substrates with broken PE film, and also possess good self-healing properties. In contrast, the self-adhesive bitumen waterproof membrane in Comparative Example 1 without ionic liquid has insufficient adhesion to complex substrates; the self-adhesive bitumen waterproof membranes in Comparative Examples 2-4 have excessive ionic liquid and insufficient SBS-g-MAH content. Although their self-healing properties are improved, their cohesive strength for adhesion to conventional substrates decreases, and their adhesion to damp substrates declines, failing to achieve synergistic optimization of multiple properties.

[0086] Example 5

[0087] Example 5 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the ionic liquid is obtained by compounding N-octylpyridine bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride in a mass ratio of 9:1.

[0088] Example 6

[0089] Example 6 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the ionic liquid is obtained by compounding N-octylpyridine bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride in a mass ratio of 8:2.

[0090] Comparative Example 5

[0091] Comparative Example 5 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the ionic liquid is obtained by compounding N-octylpyridine bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride in a mass ratio of 10:0.

[0092] Comparative Example 6

[0093] Comparative Example 6 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the ionic liquid is obtained by compounding N-octylpyridine bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride in a mass ratio of 5:5.

[0094] Comparative Example 7

[0095] Comparative Example 7 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the ionic liquid is obtained by compounding N-octylpyridine bis(trifluoromethanesulfonyl)imide and 1-allyl-3-methylimidazolium chloride at a mass ratio of 0:10.

[0096] Table 2 shows the performance test data of self-adhesive bitumen waterproof membranes using different ionic liquids in Examples 5, 6, and Comparative Examples 5 to 7.

[0097] Table 2

[0098]

[0099] As shown in Table 2, the adhesion strength between all self-adhesive bitumen waterproof membranes and the dust-laden substrates in Examples 5-6 and Comparative Examples 5-7 of this application is relatively low, showing only a slight upward trend with the increase of the proportion of hydrophilic imidazole ionic liquid (1-allyl-3-methylimidazolium chloride). The main reason is that only when the proportion of hydrophilic imidazole ionic liquid is high, its strong polarity and fluidity allow a small amount of ionic liquid to penetrate through the gaps in the dust. Since 1-allyl-3-methylimidazolium chloride has better hydrogen bonding with water molecules, it is easier to bond with the moisture on the substrate, thus forming a weak interfacial bond with the substrate below.

[0100] In Examples 5-6 and Comparative Examples 5-7 of this application, the peel strength between the self-adhesive bitumen waterproof membrane and the damp substrate increases with the increase of the proportion of hydrophilic imidazole ionic liquid. Because the cation of the hydrophilic imidazole ionic liquid is a highly polar imidazole ring, and the anion is a chloride ion that easily forms hydrogen bonds, it possesses good hydrophilicity and polar compatibility. It can stably bond with water molecules and polar groups of the substrate through hydrogen bonding, effectively solving the adhesion problem at the damp interface. As its proportion increases, the number of polar groups in the self-adhesive bitumen waterproof membrane that can participate in interfacial bonding also increases, thus improving the adhesion strength to the damp substrate.

[0101] In Examples 5-6 and Comparative Examples 5-7 of this application, the peel strength of the self-adhesive bitumen waterproof membrane to the PE film substrate with fragments generally decreased with the increase of the proportion of hydrophilic imidazole ionic liquid. In Examples 5 and 6 of this application, the peel strength of the self-adhesive bitumen waterproof membrane was stable at 1.2-1.3 N / mm, which was better than that of Comparative Example 7, which only added imidazole ionic liquid. The main reason is that the ionic liquid can penetrate the gaps in the PE film and form a bond with the bitumen substrate below the fragmented PE film. The hydrophobic pyridine ionic liquid (N-octylpyridine bis(trifluoromethanesulfonyl)imide) has a long alkyl chain substituted pyridine cation, which has stronger compatibility and bonding force with organic molecules, aged oils, etc. in the bitumen substrate, and can form a more stable interfacial bond with the bitumen substrate below at the gaps in the PE film. As the proportion of hydrophilic imidazole ionic liquid increases, the proportion of hydrophobic pyridine ionic liquid decreases simultaneously, so the interfacial bonding strength gradually decreases.

[0102] In Examples 5-6 and Comparative Examples 5-7 of this application, the 30s creep recovery rate of the self-adhesive bitumen waterproof membrane decreased with the increase of the proportion of hydrophilic imidazole ionic liquid. The recovery rate of Examples 5 and 6 of this application reached 98%-99%, which is better than that of the comparative examples. Because the hydrophobic pyridine ionic liquid has stronger ionic bond forces between its anions and cations, and its long alkyl chain structure has better compatibility with nonpolar organic molecules in the bitumen matrix, it can form a stable reversible secondary bond network in the bitumen system. When the self-adhesive bitumen waterproof membrane is subjected to external force and undergoes creep deformation, this reversible secondary bond network can drive the bitumen molecular chains to reset through rapid fracture-reconstruction, achieving good elastic recovery and self-healing effect. However, the hydrophilic imidazole ionic liquid has weaker compatibility with organic molecules in the bitumen matrix and is difficult to form a stable secondary bond network. As its proportion increases, the creep recovery rate gradually decreases, and the self-healing performance decreases.

[0103] In summary, Examples 5 and 6 of this application achieve synergistic optimization and comprehensive balance of various properties by adjusting the compounding ratio of ionic liquids. This retains both good adhesion and self-healing properties to PE film substrates with fragments, and also provides good compatibility with damp substrates, making it suitable for complex working conditions in various scenarios such as waterproofing and repair of old roofs. Comparative Example 5, which uses only hydrophobic pyridine-type ionic liquids, while exhibiting good self-healing properties, lacks sufficient hydrophilic polar groups, resulting in insufficient adhesion to damp substrates. Comparative Examples 6 and 7 have an excessively high proportion of hydrophilic imidazole-type ionic liquids, which, although slightly improving adhesion strength on damp substrates, reduces both adhesion to PE film substrates with fragments and self-healing properties.

[0104] Example 7

[0105] Embodiment 7 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Embodiment 1 is that the bitumen sheet is subjected to an electric field treatment for 1.0 s.

[0106] Comparative Example 8

[0107] Comparative Example 8 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the bitumen sheet is cooled to below 35°C by air cooling and no electric field treatment is performed to obtain the self-adhesive bitumen waterproof membrane.

[0108] Comparative Example 9

[0109] Comparative Example 9 of this application provides a self-adhesive bitumen waterproof membrane. The only difference between the preparation method of this self-adhesive bitumen waterproof membrane and Example 1 is that the bitumen sheet is not cooled down (the surface temperature of the bitumen sheet is about 70~100℃), and is directly treated with an electric field of 50kV / m for 1.0s.

[0110] Table 3 shows the performance test data of the self-adhesive bitumen waterproof membranes prepared under different cooling temperatures and electric field treatment conditions in Example 7, Comparative Examples 8 and 9.

[0111] Table 3

[0112]

[0113] As shown in Table 3, the peel strength between the self-adhesive bitumen waterproof membrane and the dust-laden substrate in Examples 7 and Comparative Examples 8-9 of this application is 0.0 N / mm, indicating no effective interfacial adhesion. This shows that whether or not the electric field treatment is applied, and the cooling temperature, does not affect this performance. This is because the physical barrier of the dust layer prevents the ionic liquid from forming an effective bond with the substrate, regardless of how the electric field is used to control the distribution and migration of the ionic liquid.

[0114] In Example 7, the peel strength of the self-adhesive asphalt waterproof membrane to a damp substrate and to a substrate with broken PE film reached 1.5 N / mm and 1.3 N / mm, respectively, both superior to Comparative Example 8 without electric field treatment and Comparative Example 9 without cooling and direct electric field treatment. The main reason is that the applied electric field can drive the directional migration of anions and cations in the ionic liquid through directional electrostatic force, causing polar ions to accumulate at the bonding interface, increasing the density of polar groups at the interface, enhancing the hydrogen bonding with polar water molecules and polar groups of the base layer on the damp substrate, and allowing more ionic liquid to penetrate the gaps in the broken PE film and form effective adhesion with the underlying asphalt substrate, thus improving the interfacial bonding strength. In this application, the asphalt sheet is cooled before being treated with an electric field, which maintains a suitable viscosity for the asphalt sheet, providing sufficient space for the directional migration of ions, while avoiding excessively high temperatures that would cause the thermal motion of ions to counteract the directional effect of the electric field, thus forming a stable ion-rich layer at the bonding interface.

[0115] The self-adhesive bitumen waterproof membrane in Example 7 achieved a 98% creep recovery rate in 30 seconds, which was superior to Comparative Examples 8 and 9. The electric field effect allows the anions and cations in the ionic liquid to arrange themselves in an orderly manner, forming a more regular and reversible secondary bond network in the self-adhesive bitumen waterproof membrane. Under external force creep, the rapid breaking and reconstruction of bonds can drive the bitumen molecular chains to reset, improving the system's elastic recovery and self-healing effect. Although an electric field was applied to Comparative Example 9, at a relatively high temperature without cooling, the random thermal motion of ions prevented the formation of a stable and ordered structure, resulting in no significant improvement in the recovery rate. Comparative Example 8, without electric field treatment, had disordered ion dispersion, failing to form a regular secondary bond network, and exhibited poor elastic recovery performance.

[0116] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A self-adhesive bitumen waterproof membrane, characterized in that, The self-adhesive bitumen waterproof membrane comprises, from the inside out, a bitumen adhesive layer and a weather-resistant layer arranged sequentially. The asphalt bonding layer comprises: a base asphalt component, a maleic anhydride-modified styrene-butadiene-styrene block copolymer, and an ionic liquid; and, by weight percentage, comprises: The base asphalt component is 95%~97%; 2-4% maleic anhydride-modified styrene-butadiene-styrene block copolymer; Ionic liquids: 0.2%~1.0%; among which, The base asphalt components include: base asphalt, softener, styrene-butadiene-styrene block copolymer, polystyrene-butadiene copolymer, tackifying resin, and inorganic filler; The ionic liquid is a compound of one of methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide with 1-allyl-3-methylimidazolium chloride, wherein the ratio of one of methyltrioctylammonium bis(trifluoromethanesulfonyl)imide and N-octylpyridine bis(trifluoromethanesulfonyl)imide with 1-allyl-3-methylimidazolium chloride is 8:2 to 9:1; The weather-resistant layer includes a fluorocarbon resin layer and a polyester / polyolefin layer; The preparation method of the self-adhesive bitumen waterproof membrane includes: The target modified asphalt is obtained by melting and mixing the base asphalt components and maleic anhydride-modified styrene-butadiene-styrene block copolymer, adding an ionic liquid, and stirring to disperse. The target modified asphalt is coated onto the surface of the fluorocarbon resin layer of the weather-resistant layer to form an asphalt bonding layer, thereby obtaining asphalt sheet material; At a temperature of 50~65℃, the asphalt sheet is passed through an electric field of 10~50kV / m to obtain a self-adhesive asphalt waterproof membrane.

2. The self-adhesive bitumen waterproof membrane according to claim 1, characterized in that, The components of the base asphalt composition, by weight, include: 45-55 parts of base asphalt; 10-15 parts of softening oil; 3-5 parts of styrene-butadiene-styrene block copolymer; 3-5 parts of polystyrene-butadiene copolymer; 2-5 parts of tackifying resin; 20-40 parts of inorganic filler.

3. The self-adhesive bitumen waterproof membrane according to claim 1, characterized in that, The base asphalt is at least one of 70# petroleum asphalt and 90# petroleum asphalt; The styrene-butadiene-styrene block copolymer has a linear structure and a number-average molecular weight of 100,000 to 140,000. The polystyrene-butadiene copolymer is a solution-polymerized polystyrene-butadiene copolymer or an emulsion-polymerized polystyrene-butadiene copolymer, with a number-average molecular weight of 80,000 to 180,000. The tackifying resin is at least one of petroleum resin, rosin resin, and terpene resin; The inorganic filler is calcium powder of 200-400 mesh; The maleic anhydride-modified styrene-butadiene-styrene block copolymer is obtained by grafting a linear styrene-butadiene-styrene block copolymer with linear maleic anhydride, with a grafting rate of 0.5% to 1.0%.

4. The self-adhesive bitumen waterproof membrane according to claim 1, characterized in that, The fluorocarbon resin layer is obtained by casting at least one of polyvinylidene fluoride, polyvinyl fluoride, and vinyl fluoride-vinyl ether copolymer. The polyester / polyolefin layer is a polyethylene terephthalate film or a polyethylene film.

5. The self-adhesive bitumen waterproof membrane according to any one of claims 1 to 4, characterized in that, The thickness of the self-adhesive bitumen waterproof membrane is 1.0~2.0mm; The thickness of the weather-resistant layer is 100μm~200μm, wherein the thickness of the fluorocarbon resin layer is 20~35μm.

6. The self-adhesive bitumen waterproof membrane according to claim 1, characterized in that, The coating temperature is 160~180℃; The asphalt sheet passes through the electric field for 0.5 to 1 second; The winding temperature of the self-adhesive bitumen waterproof membrane is 20~35℃.

7. The application of a self-adhesive bitumen waterproof membrane as described in any one of claims 1 to 6 in the waterproofing repair of construction surfaces.

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