High temperature non-fading color asphalt mixture and method of making same

Abstract

The application discloses a high-temperature non-fading color asphalt mixture and a preparation method thereof, and relates to the technical field of asphalt. The application takes iron oxide pigments as raw materials, and under the cross-linking action of a binder, takes montmorillonite as a coating agent to form a coated modified pigment through co-precipitation, so that the thermal decomposition and oxidation reaction of the pigment are inhibited, and the effects of high-temperature resistance and non-fading are achieved. Then, the modified polymer and the modified pigment are subjected to high-speed shearing at high temperature to obtain a cementing material, the dispersibility is improved through intercalation reaction, free radicals are quenched, and aging is inhibited. Finally, the cementing material is mixed with aggregate and mineral powder to obtain the color asphalt mixture, so that the effects of high-temperature resistance, non-fading and pollution resistance are achieved. The modified polymer is prepared through copolymerization of 3,3'-dimethoxy-4,4'-diphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt and erythritol, forms a three-dimensional structure, increases the contact angle of pollutants and the asphalt surface, forms a layer of closely arranged molecular layer, and significantly improves the thermal stability and the anti-fading effect.

Description

Technical Field

[0001] This invention relates to the field of asphalt technology, specifically to a high-temperature non-fading colored asphalt mixture and its preparation method. Background Technology

[0002] Asphalt pavement possesses excellent properties such as sufficient strength, high vibration damping, good tire adhesion, and ease of cleaning and maintenance, making it widely used in high-grade highways both domestically and internationally. With socio-economic development and advancements in science and technology, colored asphalt pavement has attracted increasing attention from countries worldwide. Colored asphalt pavement not only beautifies the environment and improves roadscapes but also enhances traffic warnings and delineates traffic zones.

[0003] Ordinary asphalt pavement, being black, absorbs a lot of heat, contributing to the "heat island" effect in cities during hot summers and causing severe environmental pollution. Colored asphalt pavement, with its lighter color, effectively reduces heat radiation and the urban "heat island" effect, lowering pavement temperature by 3-5°C during hot seasons. It also reduces the volatilization of lightweight components in the colored asphalt binder, making it less prone to aging and low-temperature embrittlement, extending its service life and maximizing its functionality within its lifespan. It also produces less pollution, meeting environmental protection requirements. However, due to its insufficient resistance to oil (or soil) pollution, poor resistance to ultraviolet radiation, and the influence of the environment, especially the black marks left by vehicle tires, colored asphalt pavement is easily contaminated, quickly losing its color. Furthermore, its daily maintenance costs are higher. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature non-fading colored asphalt mixture and its preparation method, so as to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-temperature non-fading colored asphalt mixture, which, by weight, mainly includes 85-111 parts of binder, 42-46 parts of coarse aggregate, 34-40 parts of fine aggregate, and 37-41 parts of mineral powder.

[0006] Furthermore, the binder is prepared by high-speed shear mixing of base oil, terpene resin, modified polymer, decolorizing agent, and modified pigment.

[0007] Furthermore, the modified polymer is prepared by copolymerization of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt, and erythritol.

[0008] Furthermore, the modified pigment is prepared by coating the surface of an iron oxide pigment with montmorillonite as a coating agent and cross-linking with a binder.

[0009] Furthermore, a method for preparing a high-temperature non-fading color asphalt mixture includes the following preparation steps:

[0010] (1) Mix 22-46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13-25 parts of docosyl hydroxypropyl quaternary ammonium salt, 10-24 parts of erythritol, and 0.5-2.5 parts of chain extender evenly, maintain at 85°C for 25-35 min under vacuum of -0.05 to -0.03 MPa, cool down to 70-80°C, add 0.03-0.07 parts of dibutyltin dilaurate, react at 110 rpm for 3-5 h, and let stand at vacuum of -0.06 to -0.08 MPa for 25-35 min to obtain the modified polymer;

[0011] (2) Disperse 11-17 parts of montmorillonite, 18-26 parts of binder, and 30-50 parts of ethanol at 60-70℃ and 200rpm for 40-60min, add 4-8 parts of iron oxide pigment, continue dispersing for 5-10min, filter with a filter screen with a pore size of 0.2-0.6μm, collect the solid, and dry at 40℃ for 10-20h to obtain the modified pigment;

[0012] (3) Place 50-60 parts of base asphalt, 32-48 parts of terpene resin with a molecular weight of 850-1250, 6-14 parts of modified polymer, 4-6 parts of decolorizing agent, and 8-18 parts of modified pigment in a high-speed shearing machine and shear at 120-150℃ and 5000-7000rpm for 20-30 minutes to obtain a binder;

[0013] (4) Mix 85-111 parts of binder, 42-46 parts of coarse aggregate, 34-40 parts of fine aggregate, and 37-41 parts of mineral powder evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0014] Furthermore, the chain extender mentioned in step (1) is any one of trimethylolpropane, neopentyl glycol, and N,N-dihydroxy(diisopropyl)aniline.

[0015] Furthermore, the adhesive in step (2) is isopropyltridodecylbenzenesulfonyl titanate.

[0016] Furthermore, in step (2), the particle size of the montmorillonite is 40-80 nm and the particle size of the iron oxide pigment is 1-2 μm; the iron oxide pigment is any one of iron oxide red, iron oxide yellow, iron oxide blue, and iron oxide green.

[0017] Furthermore, the parameters of the base asphalt in step (3) are: penetration at 25℃ 60~100mm, softening point 46~54℃, and ductility at 15℃ greater than 100cm.

[0018] Furthermore, in step (4), the coarse aggregate is crushed stone of 5-15 mm, the fine aggregate is limestone of 2.15-5.45 mm, and the particle size of the mineral powder is 0.05-0.25 mm.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] This invention uses iron oxide pigments as raw materials. Under the cross-linking action of a binder, montmorillonite is used as a coating agent to form a coated and modified pigment through co-precipitation. During heating, the layers can act as a barrier, absorbing some heat and limiting the migration and diffusion of internal metal ions, thereby inhibiting the thermal decomposition and oxidation reaction of the pigment, thus achieving high temperature resistance and non-fading effect. At the same time, the metal ions contained in montmorillonite can absorb and consume free radicals and other oxidizing substances through changes in their own oxidation state, further enhancing the anti-fading performance. Then, the modified polymer and modified pigment are sheared at high temperature and high speed to obtain a binder. During the shearing process, the cations in the modified polymer can undergo intercalation reaction with the montmorillonite on the surface of the modified pigment, which increases the interlayer spacing and improves dispersibility. This helps to better contact with free radicals in asphalt, resulting in a quenching effect and generating large molecular free radicals, thereby reducing the attack of free radicals on the asphalt mixture and effectively inhibiting aging. Finally, it is mixed with aggregates and mineral powder to obtain a colored asphalt mixture to achieve high temperature resistance, non-fading, and anti-pollution effects.

[0021] The modified polymer is prepared by copolymerization of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt, and erythritol, forming a three-dimensional structure that significantly improves thermal stability and anti-fading effect. Simultaneously, it increases the contact angle between contaminants and the asphalt surface, making it difficult for contaminants to spread and adhere to the asphalt surface, thus achieving a pollution-resistant effect. The methoxy group in 3,3'-dimethoxy-4,4'-biphenyl diisocyanate can combine with free radicals to generate relatively stable products, interrupting the free radical chain reaction process and reducing the fading of pigments due to oxidation, thus achieving anti-fading performance. The long-chain alkyl group introduced by docosyl hydroxypropyl quaternary ammonium salt has low surface energy and can form a tightly packed molecular layer on the asphalt surface, reducing the adhesion of polluting liquids to the asphalt surface, thereby achieving anti-pollution performance. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] To more clearly illustrate the method provided by the present invention, the following embodiments are provided in detail. The test methods for various indicators of the high-temperature non-fading colored asphalt mixture prepared in the following embodiments are as follows:

[0024] Marshall stability: Take the same mass of the example and comparative examples, test according to T0709, and test again after soaking in diesel at 25°C for 24 hours.

[0025] Mass loss after oil immersion: Take the same mass of the example and comparative examples, immerse them in diesel oil at 25°C for 48 hours, drain them, weigh them after immersion, and calculate the mass loss.

[0026] 60℃ rutting dynamic stability: Take the same mass of the example and comparative examples and test them according to T0719.

[0027] UV aging performance: Take the same mass of the example and comparative examples, irradiate them with a UV lamp with a wavelength of 300-360nm at an ambient temperature of 60℃ for 100h, and observe the fading of the samples. The samples are 10cm away from the UV lamp source.

[0028] Example 1

[0029] (1) 22 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13 parts of docosyl hydroxypropyl quaternary ammonium salt, 10 parts of erythritol and 0.5 parts of trimethylolpropane were mixed evenly and kept at 85°C under vacuum of -0.05MPa for 25 min. The temperature was then lowered to 70°C, and 0.03 parts of dibutyltin dilaurate were added. The mixture was stirred at 110 rpm for 3 h and then allowed to stand under vacuum of -0.06MPa for 25 min to obtain the modified polymer.

[0030] (2) 11 parts of montmorillonite with a particle size of 40 nm, 18 parts of isopropyltris(2-)-tetrate and 30 parts of ethanol were dispersed at 60 °C and 200 rpm for 40 min. 4 parts of iron oxide red with a particle size of 1 μm were added and the mixture was dispersed for another 5 min. The mixture was then filtered through a 0.2 μm pore size filter, the solid was collected, and the solid was dried at 40 °C for 10 h to obtain the modified pigment.

[0031] (3) 50 parts of base asphalt with a penetration of 60 mm at 25℃, a softening point of 46℃, and an ductility of more than 100 cm at 15℃, 32 parts of terpene resin with a molecular weight of 850, 6 parts of modified polymer, 4 parts of decolorizing agent, and 8 parts of modified pigment were placed in a high-speed shearing machine and sheared at 120℃ and 5000 rpm for 20 min to obtain the binder.

[0032] (4) Mix 85 parts of binder, 42 parts of 5mm crushed stone, 34 parts of 2.15mm limestone and 37 parts of mineral powder with a particle size of 0.05mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0033] Example 2

[0034] (1) 34 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 19 parts of docosyl hydroxypropyl quaternary ammonium salt, 17 parts of erythritol and 1.5 parts of neopentyl glycol were mixed evenly and kept at 85°C under vacuum of -0.04 MPa for 30 min. The temperature was then lowered to 75°C and 0.05 parts of dibutyltin dilaurate were added. The mixture was stirred at 110 rpm for 4 h and then allowed to stand under vacuum of -0.07 MPa for 30 min to obtain the modified polymer.

[0035] (2) 14 parts of montmorillonite with a particle size of 60 nm, 22 parts of isopropyltris(2,3-dodecylbenzenesulfonyl)titanate and 40 parts of ethanol were dispersed at 65 °C and 200 rpm for 50 min. 6 parts of iron oxide yellow with a particle size of 1.5 μm were added and the mixture was dispersed for another 7.5 min. The mixture was then filtered through a 0.4 μm pore size filter, the solid was collected, and dried at 40 °C for 15 h to obtain the modified pigment.

[0036] (3) 55 parts of base asphalt with a penetration of 80 mm at 25℃, a softening point of 50℃, and an ductility of more than 100 cm at 15℃, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizing agent, and 13 parts of modified pigment were placed in a high-speed shearing machine and sheared at 135℃ and 6000 rpm for 25 min to obtain a binder.

[0037] (4) Mix 98 parts of binder, 44 parts of 10mm crushed stone, 37 parts of 3.8mm limestone and 39 parts of mineral powder with a particle size of 0.15mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0038] Example 3

[0039] (1) 46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 25 parts of docosyl hydroxypropyl quaternary ammonium salt, 24 parts of erythritol, and 2.5 parts of N,N-dihydroxy(diisopropyl)aniline were mixed evenly and kept at 85°C under vacuum of -0.03MPa for 35 min. The mixture was then cooled to 80°C, and 0.07 parts of dibutyltin dilaurate were added. The mixture was stirred at 110 rpm for 5 h and then allowed to stand under vacuum of -0.08MPa for 35 min to obtain the modified polymer.

[0040] (2) 17 parts of montmorillonite with a particle size of 80 nm, 26 parts of isopropyltris(2,3-dodecylbenzenesulfonyl)titanate and 50 parts of ethanol were dispersed at 70 °C and 200 rpm for 60 min. 8 parts of iron oxide blue with a particle size of 2 μm were added and the mixture was dispersed for another 10 min. The mixture was then filtered through a 0.6 μm pore size filter, the solid was collected, and the solid was dried at 40 °C for 20 h to obtain the modified pigment.

[0041] (3) 60 parts of base asphalt with a penetration of 100 mm at 25℃, a softening point of 54℃, and an ductility of more than 100 cm at 15℃, 48 parts of terpene resin with a molecular weight of 1250, 14 parts of modified polymer, 6 parts of decolorizing agent, and 18 parts of modified pigment were placed in a high-speed shearing machine and sheared at 150℃ and 7000 rpm for 30 min to obtain a binder.

[0042] (4) Mix 111 parts of binder, 46 parts of 15mm crushed stone, 40 parts of 5.45mm limestone, and 41 parts of mineral powder with a particle size of 0.25mm evenly to obtain a high-temperature non-fading colored asphalt mixture.

[0043] Comparative Example 1

[0044] The difference between Comparative Example 1 and Example 2 is that step (2) is omitted, and step (3) is changed to: placing 55 parts of base asphalt with a penetration of 80 mm at 25°C, a softening point of 50°C, and a ductility greater than 100 cm at 15°C, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizing agent, and 13 parts of iron oxide yellow with a particle size of 1.5 μm in a high-speed shearing machine, and shearing at 135°C and 6000 rpm for 25 min to obtain the binder. The remaining steps are the same as in Example 2.

[0045] Comparative Example 2

[0046] The difference between Comparative Example 2 and Example 2 lies in step (3). Step (3) is changed to: mixing 55 parts of base asphalt with a penetration of 80 mm at 25°C, a softening point of 50°C, and a ductility greater than 100 cm at 15°C, 40 parts of terpene resin with a molecular weight of 1050, 10 parts of modified polymer, 5 parts of decolorizing agent, and 13 parts of modified pigment at 135°C and 200 rpm for 25 min to obtain a binder. The remaining steps are the same as in Example 2.

[0047] Comparative Example 3

[0048] The difference between Comparative Example 3 and Example 2 is that 3,3'-dimethoxy-4,4'-biphenyl diisocyanate was not added during the preparation of the modified polymer. The remaining steps were the same as in Example 2.

[0049] Comparative Example 4

[0050] The difference between Comparative Example 4 and Example 2 is that docosylhydroxypropyl quaternary ammonium salt is not added during the preparation of the modified polymer. The remaining steps are the same as in Example 2.

[0051] Comparative Example 5

[0052] The difference between Comparative Example 5 and Example 2 is that erythritol was not added during the preparation of the modified polymer. The remaining steps are the same as in Example 2.

[0053] Example of effect

[0054] Table 1 below presents the performance analysis results of the high-temperature non-fading colored asphalt mixtures of Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention.

[0055] Table 1

[0056]

[0057] A comparison of the experimental data from Examples 1, 2, and 3 with Comparative Example 1 reveals that, under the cross-linking effect of the binder, montmorillonite, as a coating agent, forms a coated and modified pigment through co-precipitation, which can act as a heat insulator, absorbing heat, limiting the migration and diffusion of internal metal ions, and inhibiting the thermal decomposition and oxidation reaction of the pigment, thus achieving high-temperature resistance and colorfastness. Simultaneously, the metal ions contained in montmorillonite absorb and consume free radicals and other oxidizing substances through changes in their own oxidation state, enhancing the anti-fading performance. A comparison of the experimental data from Examples 1, 2, and 3 with Comparative Example 2 reveals that, when a binder is prepared by high-speed shearing of the modified polymer and modified pigment at high temperature, the cations in the modified polymer can react with the surface of the modified pigment during the shearing process. Montmorillonite undergoes an intercalation reaction, which expands the interlayer spacing and improves dispersibility. This facilitates better contact with free radicals in asphalt, resulting in a quenching effect and generating large molecular free radicals. Consequently, it reduces the attack of free radicals on the asphalt mixture and effectively inhibits aging. A comparison of experimental data from Examples 1, 2, and 3 with Comparative Examples 3, 4, and 5 reveals that the modified polymer prepared by copolymerization of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt, and erythritol has a three-dimensional structure. This significantly improves thermal stability and anti-fading effect, and increases the contact angle between contaminants and the asphalt surface, making it difficult for contaminants to spread and adhere to the asphalt surface, thus achieving a pollution-resistant effect.

[0058] 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 its spirit or essential characteristics. 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A high-temperature non-fading color asphalt mixture, characterized in that, By weight, it mainly includes 85-111 parts of binder, 42-46 parts of coarse aggregate, 34-40 parts of fine aggregate, and 37-41 parts of mineral powder; The binder is prepared by high-speed shear mixing of base asphalt, terpene resin, modified polymer, decolorizing agent, and modified pigment; The modified polymer is obtained by copolymerization of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, docosyl hydroxypropyl quaternary ammonium salt, and erythritol; The modified pigment is prepared by coating the surface of an iron oxide pigment with montmorillonite as a coating agent and cross-linking with a binder.

2. A method for preparing a high-temperature non-fading color asphalt mixture, characterized in that, The preparation steps include the following: (1) Mix 22-46 parts of 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 13-25 parts of docosyl hydroxypropyl quaternary ammonium salt, 10-24 parts of erythritol, and 0.5-2.5 parts of chain extender evenly, maintain at 85°C for 25-35 min under vacuum of -0.05 to -0.03 MPa, cool down to 70-80°C, add 0.03-0.07 parts of dibutyltin dilaurate, react at 110 rpm for 3-5 h, and let stand at vacuum of -0.06 to -0.08 MPa for 25-35 min to obtain the modified polymer; (2) Disperse 11-17 parts of montmorillonite, 18-26 parts of binder, and 30-50 parts of ethanol at 60-70℃ and 200rpm for 40-60min, add 4-8 parts of iron oxide pigment, continue dispersing for 5-10min, filter with a filter screen with a pore size of 0.2-0.6μm, collect the solid, and dry at 40℃ for 10-20h to obtain the modified pigment; (3) Place 50-60 parts of base asphalt, 32-48 parts of terpene resin with a molecular weight of 850-1250, 6-14 parts of modified polymer, 4-6 parts of decolorizing agent, and 8-18 parts of modified pigment in a high-speed shearing machine and shear at 120-150℃ and 5000-7000rpm for 20-30 minutes to obtain a binder; (4) Mix 85-111 parts of binder, 42-46 parts of coarse aggregate, 34-40 parts of fine aggregate, and 37-41 parts of mineral powder evenly to obtain a high-temperature non-fading colored asphalt mixture.

3. The method for preparing a high-temperature non-fading color asphalt mixture according to claim 2, characterized in that, The chain extender mentioned in step (1) is any one of trimethylolpropane, neopentyl glycol, and N,N-dihydroxy(diisopropyl)aniline.

4. The method for preparing a high-temperature non-fading colored asphalt mixture according to claim 2, characterized in that, The adhesive used in step (2) is isopropyltridodecylbenzenesulfonyl titanate.

5. The method for preparing a high-temperature non-fading colored asphalt mixture according to claim 2, characterized in that, The montmorillonite in step (2) has a particle size of 40-80 nm and the iron oxide pigment has a particle size of 1-2 μm; the iron oxide pigment is any one of iron oxide red, iron oxide yellow, iron oxide blue, and iron oxide green.

6. The method for preparing a high-temperature non-fading colored asphalt mixture according to claim 2, characterized in that, The parameters of the base asphalt in step (3) are: penetration at 25℃ 60~100mm, softening point 46~54℃, and ductility at 15℃ greater than 100cm.

7. The method for preparing a high-temperature non-fading colored asphalt mixture according to claim 2, characterized in that, The coarse aggregate in step (4) is crushed stone of 5-15mm, the fine aggregate is limestone of 2.15-5.45mm, and the particle size of the mineral powder is 0.05-0.25mm.

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