A road surface rubber asphalt crack sealant and its preparation method

Abstract

This invention relates to the field of rubber asphalt technology, and in particular to a road rubber asphalt crack sealant and its preparation method. The road rubber asphalt crack sealant comprises the following components in parts by weight: asphalt, rubber powder, compatibilizer, modified silica, silane coupling agent, and additives. The road rubber asphalt crack sealant of this invention is formulated with asphalt, rubber powder, and modified silica. KH570 silane coupling agent is used to treat nano-silica, introducing unsaturated double bonds into the nano-silica. Then, it undergoes free radical polymerization with α-octadecene and sulfobetaine methacrylate under BPO catalysis, respectively introducing long-chain alkyl, sulfonyl, and betaine groups into the modified nano-silica, thereby improving the interfacial compatibility between the components and enhancing the high-temperature stability and mechanical properties of the sealant.

Description

Technical Field

[0001] This invention relates to the field of rubber asphalt technology, and in particular to a road rubber asphalt crack sealant and its preparation method. Background Technology

[0002] Asphalt crack sealant is a core material for repairing pavement cracks, and its performance directly determines the pavement's resistance to damage and its service life. Traditional crack sealants typically use asphalt as a matrix, adjusting their temperature sensitivity and mechanical properties by incorporating rubber powder or thermoplastic elastomers (such as SBS). However, these materials have significant drawbacks in practical applications: at high temperatures, the viscoelasticity of the asphalt matrix decreases, causing the sealant to soften or even flow, making it difficult to maintain its sealing effect on cracks; while at low temperatures, the material's rigidity increases sharply, its ductility decreases, and it is prone to brittle fracture, especially in areas with large diurnal temperature variations or severe seasonal climates, where repeated thermal expansion and contraction accelerate interfacial delamination, ultimately leading to secondary cracking. Furthermore, existing technologies that excessively increase the SBS content to improve high-temperature stability not only significantly increase costs but also exacerbate elastic failure after UV aging. Under long-term exposure, the material surface exhibits significant powdering and hardening, with a bond strength attenuation rate exceeding 40%.

[0003] In recent years, the introduction of nanofillers has been considered an important direction for improving the performance of crack sealants. For example, nano-silica, due to its high specific surface area and surface activity, can effectively enhance the mechanical strength and thermal stability of materials. However, in conventional processes, nanoparticles are prone to agglomeration into micron-sized particles due to the surface energy difference between nanoparticles and the asphalt matrix. This not only weakens the reinforcing effect but also creates stress concentration points within the material, inducing microcrack propagation under dynamic loads. To solve the dispersion problem, existing technologies often use a single silane coupling agent (such as KH550 and KH570) to modify the surface of nano-silica. However, its mechanism of action is limited to physical coating or simple chemical bonding. In complex environments (such as humid heat and freeze-thaw cycles), the coupling agent molecular chains are prone to hydrolysis or breakage, leading to debonding between nanoparticles and the matrix interface. More seriously, some modification processes require high-temperature, long-term reactions or large amounts of organic solvents, which not only consumes a lot of energy but also releases volatile organic compounds, contradicting the current demand for green and environmentally friendly industries. Therefore, breakthroughs are urgently needed through innovative material design and process optimization. Summary of the Invention

[0004] Therefore, it is necessary to provide a road surface rubber asphalt crack sealant. The present invention uses α-octadecene and sulfobetaine methacrylate to perform dual surface modification on nano-silica, which significantly improves the interfacial bonding strength and temperature stability.

[0005] One object of the present invention is to provide a road surface rubber asphalt crack sealant, comprising the following components in parts by weight: 60-75 parts asphalt 10-30 parts of rubber powder 20-30 parts compatibilizer 10-15 parts of modified silica 1-3 parts of silane coupling agent 1-15 parts of auxiliary agent; The modified silica is obtained by reacting α-octadecene, sulfobetaine methacrylate, and KH570-treated nano-silica.

[0006] Furthermore, the asphalt is selected from one or more of petroleum asphalt, natural asphalt, and blended asphalt.

[0007] Furthermore, the particle size of the rubber powder is 20-80 mesh.

[0008] Furthermore, the silane coupling agent is selected from one or more of A151, A171, and A172.

[0009] Furthermore, the compatibilizer is selected from one or more of naphthenic oils, aromatic oils, and reduced-strength extracted oils.

[0010] Furthermore, the additive is selected from one or more of stabilizers and rubber vulcanizing agents.

[0011] Furthermore, the rubber vulcanizing agent is selected from one or more of sulfur, rubber accelerator D, TMTD, or rubber accelerator M.

[0012] The present invention also provides a method for preparing the road rubber asphalt crack sealant, the method comprising the following steps: S1. Under the protection of an inert gas, nano-silica is blended with KH570 and heated to react, yielding an intermediate product; S2. Under the protection of an inert gas, the intermediate product, α-octadecene, and sulfobetaine methacrylate are blended, an initiator is added, and the mixture is heated to react and obtain modified silica. S3. Mix the modified silica with other components evenly, heat and shear it in a high-speed shear emulsifier to obtain the road rubber asphalt crack sealant.

[0013] Furthermore, in step S1, the temperature of the heating reaction is 100-110°C.

[0014] Furthermore, in step S2, the temperature of the heating reaction is 75-85°C.

[0015] The present invention has the following beneficial effects: The road surface rubber asphalt crack sealant of this invention is formulated with asphalt, rubber powder, and modified silica. First, nano-silica is treated with KH570 silane coupling agent to introduce unsaturated double bonds into the nano-silica. Then, it undergoes free radical polymerization with α-octadecene and sulfobetaine methacrylate under BPO catalysis, introducing long-chain alkyl, sulfonyl, and betaine groups into the modified nano-silica. On the one hand, the introduction of long alkyl chains of octadecene into the modified nano-silica effectively regulates the interfacial properties of the modified nano-silica, improves the compatibility between the modified nano-silica and asphalt and rubber powder, and avoids the agglomeration of the modified nano-silica. Furthermore, the long-chain alkyl groups can... The modified nano-silica can cross-link with asphalt or rubber powder through molecular entanglement, forming a physical cross-linked network, which improves the interfacial compatibility between the components and thus enhances the high-temperature stability and mechanical properties of the sealant. Secondly, since the modified nano-silica also introduces hydrophilic groups such as sulfonyl and betaine groups, the sulfonyl group can form hydrogen bonds with polar groups such as oxygen-containing groups in the asphalt, further enhancing the interfacial bonding force between the components, while the flexible segments of betaine can improve the elasticity of the sealant and increase its tensile strength. In addition, due to the hydrophilic properties of sulfonyl and betaine groups, the adhesion between the sealant and the crack surface (especially the damp substrate) can be enhanced, preventing the sealant from peeling off and significantly improving the mechanical properties of the sealant. Detailed Implementation

[0016] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0017] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0018] It should be understood that, except in any operational instance or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term "about". Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximations varying with the desired performance to be obtained according to the invention.

[0019] Asphalt, AH-90 petroleum asphalt, purchased from Hebei Dezhishan Petrochemical Co., Ltd.

[0020] Rubber powder, 40 mesh, purchased from Lingshou Yiteng New Material Technology Co., Ltd.

[0021] Silane coupling agent, A151, vinyltriethoxysilane.

[0022] Compatibilizer, reduced-strength extraction oil, 100SN, purchased from Shenzhen Huameite Lubrication Technology Co., Ltd.

[0023] Stabilizer: Chromic anhydride.

[0024] Rubber vulcanizing agent, rubber accelerator M, and 2-mercaptobenzothiazole were purchased from Nanjing Reagent Center.

[0025] Sulfobetaine methacrylate, 537284, purchased from Sigma.

[0026] KH570, γ-methacryloyloxypropyltrimethoxysilane.

[0027] BPO, benzoyl peroxide.

[0028] Example 1 A type of road surface rubber asphalt crack sealant, comprising the following components in parts by weight: 63 parts asphalt 15 parts rubber powder 23 parts compatibilizer 11 parts of modified silica 1 part of silane coupling agent 1 part stabilizer 3 parts rubber vulcanizing agent; The preparation method of the above-mentioned road rubber asphalt crack sealant includes the following steps: S1. By weight, under nitrogen protection, 10 parts of nano-silica and 3 parts of KH570 were mixed and added to 80 parts of toluene. After ultrasonic dispersion for 30 min, the mixture was heated to 110℃ and reacted for 5 h. After filtration, the mixture was washed three times with deionized water and dried to obtain the intermediate product. S2. Mix 5 parts of intermediate product, 10 parts of α-octadecene and 5 parts of sulfobetaine methacrylate with 80 parts of toluene. Under nitrogen protection, add 1 part of BPO as a catalyst and react at 80°C for 5 hours. After cooling, filter, wash three times with deionized water and dry to obtain the modified silica. S3. According to the above mass proportions, mix the modified silica with the other components except the stabilizer and rubber vulcanizing agent evenly, add it to the high-speed shear emulsifier, shear at a shearing temperature of 160℃ for 45 minutes, then add the stabilizer and rubber vulcanizing agent, keep warm and stir for 50 minutes to obtain the road rubber asphalt crack sealant.

[0029] Example 2 A type of road surface rubber asphalt crack sealant, comprising the following components in parts by weight: 66 parts asphalt 17 parts rubber powder 25 parts compatibilizer 12 parts of modified silica 2 parts of silane coupling agent 1 part stabilizer 3 parts rubber vulcanizing agent; The preparation method of the above-mentioned road rubber asphalt crack sealant includes the following steps: S1. By weight, under nitrogen protection, 10 parts of nano-silica and 3 parts of KH570 were mixed and added to 80 parts of toluene. After ultrasonic dispersion for 30 min, the mixture was heated to 110℃ and reacted for 5 h. After filtration, the mixture was washed three times with deionized water and dried to obtain the intermediate product. S2. Mix 5 parts of intermediate product, 10 parts of α-octadecene and 5 parts of sulfobetaine methacrylate with 80 parts of toluene. Under nitrogen protection, add 1 part of BPO as a catalyst and react at 80°C for 5 hours. After cooling, filter, wash three times with deionized water and dry to obtain the modified silica. S3. According to the above mass proportions, mix the modified silica with the other components except the stabilizer and rubber vulcanizing agent evenly, add it to the high-speed shear emulsifier, shear at a shearing temperature of 160℃ for 45 minutes, then add the stabilizer and rubber vulcanizing agent, keep warm and stir for 50 minutes to obtain the road rubber asphalt crack sealant.

[0030] Example 3 A type of road surface rubber asphalt crack sealant, comprising the following components in parts by weight: 70 parts asphalt 18 parts of rubber powder 27 parts compatibilizer 14 parts of modified silica 2 parts of silane coupling agent 1 part stabilizer 3 parts rubber vulcanizing agent; The preparation method of the above-mentioned road rubber asphalt crack sealant includes the following steps: S1. By weight, under nitrogen protection, 10 parts of nano-silica and 3 parts of KH570 were mixed and added to 80 parts of toluene. After ultrasonic dispersion for 30 min, the mixture was heated to 110℃ and reacted for 5 h. After filtration, the mixture was washed three times with deionized water and dried to obtain the intermediate product. S2. Mix 5 parts of intermediate product, 10 parts of α-octadecene and 5 parts of sulfobetaine methacrylate with 80 parts of toluene. Under nitrogen protection, add 1 part of BPO as a catalyst and react at 80°C for 5 hours. After cooling, filter, wash three times with deionized water and dry to obtain the modified silica. S3. According to the above mass proportions, mix the modified silica with the other components except the stabilizer and rubber vulcanizing agent evenly, add it to the high-speed shear emulsifier, shear at a shearing temperature of 160℃ for 45 minutes, then add the stabilizer and rubber vulcanizing agent, keep warm and stir for 50 minutes to obtain the road rubber asphalt crack sealant.

[0031] Comparative Example 1 A type of sealant, the difference between this comparative example and Example 1 is that in step S2, α-octadecene is removed, and only sulfobetaine methacrylate is used to react with the intermediate product, while the other components and preparation methods are the same.

[0032] Comparative Example 2 A type of sealant, the difference between this comparative example and Example 1 is that in step S2, butyl acrylate of equal mass is used to replace sulfobetaine methacrylate, while other components and preparation methods are the same.

[0033] Comparative Example 3 A type of grouting adhesive, brand name 20241022, was purchased from Dongping Dingxiang New Materials Center.

[0034] Test case The performance of the sealant prepared in Example 1 and Comparative Examples 1-2 was tested.

[0035] The test was conducted in accordance with the standard for the ordinary type in section 5.2 of JT-T2009-740 "Standard for Crack Sealing Adhesive for Asphalt Pavement".

[0036] The test results are shown in Table 1.

[0037] Table 1. Performance test results of the sealant in Example 1 and Comparative Examples 1-2 Low temperature stretching pass 1 failed pass 2 failed Cone penetration (0.1mm) 67 59 63 57 Softening point (%) 97 91 93 88 Flow value (mm) 0.6 0.9 0.7 1.3 Elastic recovery rate (%) 76 68 73 61 According to Table 1, the sealant of the present invention has better adhesion, resilience and temperature stability. The sealant of Example 1 has excellent overall performance, with outstanding low-temperature flexibility, high-temperature stability (high softening point, low flow value) and elastic recovery ability, which fully meet the standard requirements. However, Comparative Examples 1 and 3 have key defects such as low-temperature failure or poor high-temperature flow resistance. The performance of Comparative Example 2 is inferior to that of Example 1 in all aspects.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A road surface rubber asphalt crack sealant, characterized in that, The ingredients include the following parts by weight: 60-75 parts asphalt 10-30 parts of rubber powder 20-30 parts compatibilizer 10-15 parts of modified silica 1-3 parts of silane coupling agent 1-15 parts of auxiliary agent; The modified silica is obtained by reacting α-octadecene, sulfobetaine methacrylate, and KH570-treated nano-silica. The specific preparation process of the modified silica includes: S1. Under the protection of an inert gas, nano-silica is blended with KH570 and heated to react, yielding an intermediate product; S2. Under the protection of an inert gas, 5 parts of intermediate product, 10 parts of α-octadecene, and 5 parts of sulfobetaine methacrylate are blended, an initiator is added, and the mixture is heated to react and obtain modified silica.

2. The road surface rubber asphalt crack sealant according to claim 1, characterized in that, The asphalt is selected from one or more of petroleum asphalt, natural asphalt, and blended asphalt.

3. The road surface rubber asphalt crack sealant according to claim 1, characterized in that, The rubber powder has a particle size of 20-80 mesh.

4. The road surface rubber asphalt crack sealant according to claim 1, characterized in that, The compatibilizer is selected from one or more of naphthenic oils, aromatic oils, and reduced-strength extracted oils.

5. The road surface rubber asphalt crack sealant according to claim 1, characterized in that, The silane coupling agent is selected from one or more of A151, A171, and A172.

6. The road surface rubber asphalt crack sealant according to claim 1, characterized in that, The additives are selected from one or more of stabilizers and rubber vulcanizing agents.

7. The road surface rubber asphalt crack sealant according to claim 6, characterized in that, The rubber vulcanizing agent is selected from one or more of sulfur, rubber accelerator D, TMTD, or rubber accelerator M.

8. The method for preparing the pavement rubber asphalt crack sealant according to any one of claims 1-7, characterized in that, The preparation method of the road rubber asphalt crack sealant includes the following steps: S1. Under the protection of an inert gas, nano-silica is blended with KH570 and heated to react, yielding an intermediate product; S2. Under the protection of an inert gas, the intermediate product, α-octadecene, and sulfobetaine methacrylate are blended, an initiator is added, and the mixture is heated to react and obtain modified silica. S3. Mix the modified silica with other components evenly, heat and shear it in a high-speed shear emulsifier to obtain the road rubber asphalt crack sealant.

9. The method for preparing the pavement rubber asphalt crack sealant according to claim 8, characterized in that, In step S1, the temperature of the heating reaction is 100-110℃.

10. The method for preparing the pavement rubber asphalt crack sealant according to claim 8, characterized in that, In step S2, the temperature of the heating reaction is 75-85℃.