A fog seal layer material with reversible heat reflection function and its preparation method

Abstract

The present invention discloses a fog seal layer material with reversible heat reflection function and its preparation method, which relates to the technical field of road engineering. The fog seal layer material comprises 60 - 77 parts of a moisture-curing polyurethane material, 0.04 - 0.12 parts of a wetting and dispersing agent, 0.4 - 1.2 parts of a heat reflection powder, and 12 - 24 parts of an alcohol solvent, wherein: the heat reflection powder is VO2 nano powder doped with 1.5% tungsten in M phase, with a particle size of 200 nanometers; the moisture-curing polyurethane material is a one-component polyurethane material, which consists of the following components: 15 - 18 parts of an aliphatic diisocyanate monomer, 38 - 42 parts of a polyether polyol, 5 - 34 parts of a plasticizer, 0.04 - 0.08 parts of a catalyst, 1 - 1.5 parts of a foam stabilizer, 7 - 12 parts of a chain extender, and 2 - 6 parts of a crosslinking agent. The preparation process of the fog seal layer material includes: preparing the moisture-curing polyurethane material, preparing the vanadium oxide sol system, and mixing the two to obtain the fog seal layer material. The fog seal layer material prepared by the present invention can more effectively adapt to the strain of the road surface and inhibit the expansion of cracks, and at the same time has excellent waterproof and anti-seepage performance, and can more effectively prevent the occurrence of road surface water damage diseases.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and specifically relates to a fog seal layer material with reversible heat reflection function and a preparation method thereof. Background Art

[0002] Asphalt pavements have been widely used in the field of expressways in China due to their good flatness, driving comfort and safety. Due to the special composition and color of the asphalt pavement materials, they have a high solar heat radiation absorption rate. Especially in summer, the surface temperature of the asphalt pavement is extremely easy to rise under the long-term irradiation of solar heat radiation. The excessive pavement temperature leads to an increase in the fluidity of the asphalt, and it is easy to form high-temperature diseases such as ruts, potholes and bumps under the action of wheel loads. Similarly, in winter with relatively low temperatures, the asphalt pavement has a high heat radiation coefficient and the heat loss is relatively fast, which is not conducive to the prevention and control of low-temperature cracking and snow and ice freezing of the pavement in winter.

[0003] In view of this situation, the current solutions include two methods: increasing the pavement reflectivity and changing the pavement heat storage characteristics. The first method is to increase the reflection coating on the road surface to improve the reflectivity of the road surface to sunlight, which can effectively reduce the pavement temperature in summer. However, the pavement with a high reflectivity is more likely to form low-temperature diseases in winter. The principle of the second method of changing the pavement heat storage characteristics is to use three-layer asphalt mixture specimens to make the thermal conductivity of the surface layer the highest and the bottom layer the lowest, and guide the heat to transfer downward, so as to reduce the temperature field of the asphalt surface layer structure. The disadvantage is that heat will be transferred in the reverse direction at night, and the heat transfer effect is less than satisfactory. Summary of the Invention

[0004] In view of the requirements and deficiencies in the current technology development, the present invention provides a fog seal layer material with reversible heat reflection function and a preparation method thereof. By using tungsten-doped vanadium dioxide nanopowder as the functional component of the reversible heat reflection material and mixing it with a moisture-curing polyurethane material, the heat reflection optical characteristics of the fog seal layer material and the good adhesion characteristics between the seal layer and the asphalt mixture are realized, effectively alleviating the rutting of high-temperature diseases of asphalt pavements in summer and the problems of low-temperature diseases of pavements in winter.

[0005] In the first aspect, the present invention provides a fog seal layer material with reversible heat reflection function, and the technical solution adopted to solve the above technical problems is as follows:

[0006] A fog seal layer material with reversible heat reflection function, the components and parts by weight of which are: 60-77 parts of moisture-curing polyurethane material, 0.04-0.12 parts of wetting and dispersing agent, 0.4-1.2 parts of heat reflection powder, and 12-24 parts of alcohol solvent. Among them, the heat reflection powder is VO2 nanopowder doped with 1.5% tungsten in the M phase, and the particle size is 200 nanometers;

[0007] The moisture-curing polyurethane material is a one-component polyurethane material, which is composed of the following components: 15-18 parts of aliphatic diisocyanate monomer, 38-42 parts of polyether polyol, 5-34 parts of plasticizer, 0.04-0.08 parts of catalyst, 1-1.5 parts of foam stabilizer, 7-12 parts of chain extender, and 2-6 parts of crosslinking agent.

[0008] Optionally, the aliphatic diisocyanate monomer is a composition of one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate;

[0009] The polyether polyol is a composition of one or more of polytetrahydrofuran diol, polypropylene oxide ether diol, and polyoxypropylene diol;

[0010] The plasticizer is selected as dioctyl epoxy tetrahydrophthalate;

[0011] The catalyst is selected as dibutyltin dilaurate, tin octoate, or bismuth octoate;

[0012] The foam stabilizer is selected as silicone surfactant;

[0013] The chain extender is selected as ethylene glycol, 2-methyl-1,3-propanediol, or 1,4-butanediol;

[0014] The crosslinking agent is selected as trimethylolbutane, hydroxypropyl acrylate, or N-methylolacrylamide.

[0015] Optionally, the wetting and dispersing agent is polyvinylpyrrolidone.

[0016] Optionally, the alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a ratio of 1:1.

[0017] In the second aspect, the present invention provides a preparation method of a fog seal layer material with reversible heat reflection function. The technical solution adopted to solve the above technical problems is as follows:

[0018] A preparation method of a fog seal layer material with reversible heat reflection function. The components and weight parts of the fog seal layer material are: 60-77 parts of moisture-curing polyurethane material, 0.04-0.12 parts of wetting and dispersing agent, 0.4-1.2 parts of heat reflection powder, and 12-24 parts of alcohol solvent. Among them, the heat reflection powder is VO2 nanometer powder doped with 1.5% tungsten in M phase, with a particle size of 200 nanometers. The moisture-curing polyurethane material is a one-component polyurethane material, which is composed of the following components: 15-18 parts of aliphatic diisocyanate monomer, 38-42 parts of polyether polyol, 5-34 parts of plasticizer, 0.04-0.08 parts of catalyst, 1-1.5 parts of foam stabilizer, 7-12 parts of chain extender, and 2-6 parts of crosslinking agent;

[0019] The preparation process of the fog seal layer material includes:

[0020] (1) Add polyether polyol, chain extender and crosslinking agent into the reaction kettle, heat up to 110 °C and stir under vacuum for dehydration for 1 h;

[0021] (2) Cool down to 80 °C, dropwise add aliphatic diisocyanate monomer and catalyst into the reaction kettle according to the measurement, and keep the temperature for reaction for 1.5 - 3 h;

[0022] (3) Cool down to 50 °C, add foam stabilizer and plasticizer, stir at a speed of 500 - 800 revolutions per minute for 30 min and then discharge to obtain a moisture-curing polyurethane material;

[0023] (4) Mix the heat-reflective powder, wetting and dispersing agent, and alcohol solvent, stir and reflux in silicone oil at 100 °C - 120 °C for 1.5 - 2 h to form a composite alcoholate solution of vanadium;

[0024] (5) Cool down to room temperature, add 5% acetic acid solution to adjust the pH to neutral, stir at a speed of 300 revolutions per minute for 10 minutes and then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 - 2 h and then discharge to obtain a vanadium oxide sol system;

[0025] (6) Mix and stir the moisture-curing polyurethane material obtained in step (3) and the vanadium oxide sol obtained in step (5) at room temperature to obtain a fog seal layer material with reversible heat reflection function.

[0026] Optionally, when performing step (1), the vacuum degree is -0.2 Mpa, and the stirring speed is 1000 - 1500 revolutions per minute.

[0027] Optionally, the room temperature in steps (5) and (6) is 21 °C - 25 °C.

[0028] Optionally, the aliphatic diisocyanate monomer is a composition of one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate;

[0029] The polyether polyol is a composition of one or more of polytetrahydrofuran diol, polypropylene oxide ether diol, and polypropylene glycol;

[0030] The plasticizer is selected as dioctyl epoxy tetrahydrophthalate;

[0031] The catalyst is selected as dibutyltin dilaurate, tin octoate, or bismuth octoate;

[0032] The foam stabilizer is selected as silicone surfactant;

[0033] The chain extender is selected as ethylene glycol, 2-methyl-1,3-propanediol, or 1,4-butanediol;

[0034] The crosslinking agent is selected as trimethylolbutane, hydroxypropyl acrylate, or N-methylolacrylamide;

[0035] The wetting and dispersing agent is polyvinylpyrrolidone;

[0036] The alcohol solvent is a benzyl alcohol - isobutanol solution mixed in a 1:1 ratio.

[0037] Optionally, the fog seal layer material prepared in step (6) is evenly sprayed on the surface of the asphalt road using a special fog seal layer curing equipment, and after curing, a protective layer with temperature sensitivity and optical properties is formed to achieve the negative feedback regulation of the road surface to temperature.

[0038] A fog seal layer material with reversible heat reflection function and its preparation method of the present invention have the following beneficial effects compared with the prior art:

[0039] (1) In the fog seal layer material of the present invention, tungsten - doped vanadium dioxide nanopowder is added as a heat - reflecting powder. Utilizing the characteristic that M - phase VO2 spontaneously generates a reversible semiconductor - metal phase transition near 305K, which causes changes in optical properties. When the temperature is lower than 305K, the fog seal layer material has a high near - infrared transmittance, and the transmittance can reach more than 75%, which is beneficial to maintaining the road surface temperature in the low - temperature state; when the temperature is higher than 305K, more visible light in the near - infrared band will be reflected, which helps to reduce the absorption of heat radiation by the road surface;

[0040] (2) The fog seal layer material of the present invention realizes the application of reversible heat reflectivity response in the field of asphalt pavement maintenance by compounding vanadium oxide sol with optical energy - saving performance and wet - curing polyurethane material with bonding performance;

[0041] (3) The present invention uses M - phase tungsten - doped vanadium dioxide nanopowder as a raw material to prepare a fog seal layer material with reversible heat reflection performance, and reduces the phase transition temperature to 38°C, which better meets the application scenario requirements of the negative feedback regulation of road surface temperature compared with traditional vanadium dioxide thin films (phase transition temperature is about 68°C);

[0042] (4) The fog seal layer material prepared by the present invention is sprayed into a film on the surface of the asphalt mixture using a special fog seal layer curing equipment, and the film thickness is between 0.2 - 0.5mm. The visible light transmittance of this material is about 40 - 50%, the infrared light reflectance at room temperature is about 20 - 30%, and the infrared light reflectance at high temperature is about 60 - 80%;

[0043] (5) Compared with the traditional emulsified asphalt - based fog seal layer material, the fog seal layer material prepared by the present invention shows higher bonding performance and mechanical properties, can more effectively adapt to the strain of the road surface and inhibit the expansion of cracks; at the same time, it has excellent waterproof and anti - seepage performance, and can more effectively prevent the occurrence of road surface water damage diseases. Description of the Drawings

[0044] Appended Figure 1 It is a schematic diagram of the reflectivity detection results of the fog seal layer obtained in the first embodiment of the present invention and the comparative example. Detailed implementation manners

[0045] To make the technical solutions, the technical problems to be solved and the technical effects of the present invention clearer and more understandable, the following combines specific embodiments to clearly and completely describe the technical solutions of the present invention.

[0046] First Embodiment:

[0047] This embodiment provides a fog seal layer material with reversible heat reflection function, and its components include a moisture-curing polyurethane material, 0.5 g of a wetting and dispersing agent, 5 g of heat-reflective powder, and 100 ml of an alcohol solvent, where:

[0048] The moisture-curing polyurethane material is a one-component polyurethane material, which consists of the following components: 220 g of an aliphatic diisocyanate monomer, 400 g of a polyether polyol, 110 g of a plasticizer, 0.4 g of a catalyst, 12 g of a foam stabilizer, 72 g of a chain extender, and 22 g of a crosslinking agent;

[0049] The heat-reflective powder is VO2 nanometer powder doped with 1.5% tungsten in the M phase, and the particle size is 200 nanometers.

[0050] In this embodiment, the aliphatic diisocyanate monomer is selected as isophorone diisocyanate, the polyether polyol is selected as polytetrahydrofuran diol, the plasticizer is selected as dioctyl epoxy tetrahydrophthalate, the catalyst is selected as dibutyltin dilaurate, the foam stabilizer is selected as an organosilicon surfactant, the chain extender is selected as 1,4-butanediol, the crosslinking agent is selected as trimethylolbutane, the wetting and dispersing agent is polyvinylpyrrolidone, and the alcohol solvent is a benzyl alcohol-isobutyl alcohol solution mixed in a 1:1 ratio.

[0051] The preparation method of the fog seal layer material described in this embodiment includes the following steps:

[0052] (1) Add 400 g of polytetrahydrofuran diol, 72 g of 1,4-butanediol, and 22 g of trimethylolbutane to the reaction kettle, heat up to 110 °C, and stir under vacuum for dehydration for 1 h; during this process, the vacuum degree is -0.2 Mpa, and the stirring speed is 1000-1500 revolutions per minute;

[0053] (2) Cool down to 80 °C, add 220 g of isophorone diisocyanate and 0.4 g of dibutyltin dilaurate into the reaction kettle, and keep the reaction under nitrogen protection for 3 h;

[0054] (3) After using dibutylamine titration to measure the NCO value and reaching 2.8%, the temperature is lowered to 50°C. Then, 12 g of organosilicon surfactant and 110 g of dioctyl epoxy tetrahydrophthalate are added. After stirring for 30 min, it is cooled and discharged to obtain a moisture-curing polyurethane material;

[0055] (4) 5 g of tungsten-doped vanadium dioxide nanopowder, 0.5 g of polyvinylpyrrolidone are mixed with 100 ml of benzyl alcohol-isobutanol solution, and stirred and refluxed in silicone oil at 120°C for 1.5 h to form a composite alkoxide solution of vanadium;

[0056] (5) The temperature is lowered to room temperature (21°C - 25°C), and 5% acetic acid solution is added to adjust the pH of the system to 7.0. After stirring at a speed of 300 rpm for 10 minutes, the speed is gradually reduced to 150 rpm and stirring is continued for 1 h before discharging to obtain a vanadium oxide sol system;

[0057] (6) 100 g of the moisture-curing polyurethane material obtained in step (3) and 12 g of the vanadium oxide sol obtained in step (5) are mixed and stirred evenly at room temperature (21°C - 25°C), then sprayed on the surface of the asphalt mixture and left to cure at room temperature for 24 h to obtain a reversible heat-reflective fog seal layer.

[0058] Example Two:

[0059] This example proposes a fog seal layer material with reversible heat-reflective function, whose components include a moisture-curing polyurethane material, 0.7 g of wetting and dispersing agent, 7 g of heat-reflective powder, and 100 ml of alcohol solvent, where:

[0060] The moisture-curing polyurethane material is a one-component polyurethane material, which consists of the following components: 230 g of aliphatic diisocyanate monomer, 400 g of polyether polyol, 180 g of plasticizer, 0.4 g of catalyst, 18 g of foam stabilizer, 86 g of chain extender, and 26 g of crosslinking agent;

[0061] The heat-reflective powder is VO2 nanopowder doped with 1.5% tungsten in M phase, with a particle size of 200 nanometers.

[0062] In this example, the aliphatic diisocyanate monomer is selected as isophorone diisocyanate, the polyether polyol is selected as polytetrahydrofuran diol, the plasticizer is selected as dioctyl epoxy tetrahydrophthalate, the catalyst is selected as dibutyltin dilaurate, the foam stabilizer is selected as organosilicon surfactant, the chain extender is selected as 1,4-butanediol, the crosslinking agent is selected as trimethylolbutane, the wetting and dispersing agent is polyvinylpyrrolidone, and the alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a 1:1 ratio.

[0063] The preparation method of the fog seal layer material described in this example includes the following steps:

[0064] (1) Add 400 g of polytetrahydrofuran diol, 86 g of 1,4-butanediol, and 26 g of trimethylolbutane into a reaction kettle, heat up to 110 °C, and stir under vacuum for dehydration for 1.5 h. During this process, the vacuum degree is -0.2 Mpa, and the stirring speed is 1000 - 1500 revolutions per minute;

[0065] (2) Cool down to 80 °C, add 230 g of isophorone diisocyanate and 0.4 g of dibutyltin dilaurate into the reaction kettle, and keep the reaction at a constant temperature for 2.5 h under nitrogen protection;

[0066] (3) After using dibutylamine titration to determine that the NCO value reaches 2.7%, cool down to 50 °C, add 18 g of silicone surfactant and 180 g of dioctyl epoxy tetrahydrophthalate, stir for 30 min, and then cool and discharge to obtain a moisture-curing polyurethane material;

[0067] (4) Mix 7 g of tungsten-doped vanadium dioxide nanopowder, 0.7 g of polyvinylpyrrolidone with 100 ml of benzyl alcohol-isobutanol solution, stir and reflux in silicone oil at 120 °C for 1.5 h to form a composite alkoxide solution of vanadium;

[0068] (5) Cool down to room temperature of 21 °C - 25 °C, add 5% acetic acid solution to adjust the pH of the system to 7.0, stir at a speed of 300 revolutions per minute for 10 minutes, then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 h before discharging to obtain a vanadium oxide sol system;

[0069] (6) Mix 100 g of the moisture-curing polyurethane material obtained in step (3) with 20 g of the vanadium oxide sol obtained in step (5) evenly at room temperature of 21 °C - 25 °C, spray it on the surface of the asphalt mixture, and let it stand and cure at room temperature for 24 h to obtain a reversible heat-reflective fog seal layer.

[0070] Example 3:

[0071] This example proposes a fog seal layer material with reversible heat-reflective function, and its components include a moisture-curing polyurethane material, 0.9 g of wetting and dispersing agent, 9 g of heat-reflective powder, and 100 ml of alcohol solvent, where:

[0072] The moisture-curing polyurethane material is a one-component polyurethane material, which consists of the following components: 260 g of aliphatic diisocyanate monomer, 600 g of polyether polyol, 180 g of plasticizer, 0.7 g of catalyst, 18 g of foam stabilizer, 72 g of chain extender, and 28 g of crosslinking agent;

[0073] The heat-reflective powder is VO2 nanopowder doped with 1.5% of tungsten in M phase, and the particle size is 200 nanometers.

[0074] In this embodiment, the aliphatic diisocyanate monomer is selected as dicyclohexylmethane diisocyanate, the polyether polyol is selected as polypropylene glycol, the plasticizer is selected as dioctyl epoxy tetrahydrophthalate, the catalyst is selected as dibutyltin dilaurate, the foam stabilizer is selected as silicone surfactant, the chain extender is selected as 1,4-butanediol, the crosslinking agent is selected as hydroxypropyl acrylate, the wetting and dispersing agent is polyvinylpyrrolidone, and the alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a 1:1 ratio.

[0075] The preparation method of the fog seal layer material described in this embodiment includes the following steps:

[0076] (1) Add 600 g of polypropylene glycol, 72 g of 1,4-butanediol, and 28 g of hydroxypropyl acrylate to the reaction kettle, heat up to 120 °C, and stir under vacuum for dehydration for 1.5 h; during this process, the vacuum degree is -0.2 Mpa, and the stirring speed is 1000-1500 revolutions per minute;

[0077] (2) Cool down to 80 °C, add 260 g of dicyclohexylmethane diisocyanate and 0.7 g of dibutyltin dilaurate into the reaction kettle, and keep the temperature for reaction for 2.5 h under nitrogen protection;

[0078] (3) After using dibutylamine titration to measure that the NCO value reaches 2.5%, cool down to 50 °C, add 18 g of silicone surfactant and 180 g of dioctyl epoxy tetrahydrophthalate, stir for 30 min, and then cool and discharge to obtain a moisture-curing polyurethane material;

[0079] (4) Mix 9 g of tungsten-doped vanadium dioxide nanopowder, 0.9 g of polyvinylpyrrolidone with 100 ml of benzyl alcohol-isobutanol solution, and stir and reflux in silicone oil at 120 °C for 2 h to form a composite alcoholate solution of vanadium;

[0080] (5) Cool down to room temperature of 21 °C - 25 °C, add 5% acetic acid solution to adjust the pH of the system to 7.0, stir at a speed of 300 revolutions per minute for 10 minutes, then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 h before discharging to obtain a vanadium oxide sol system;

[0081] (6) Mix 100 g of the moisture-curing polyurethane material obtained in step (3) with 23 g of the vanadium oxide sol obtained in step (5) evenly at room temperature of 21 °C - 25 °C, spray it on the surface of the asphalt mixture, and let it stand and cure at room temperature for 24 h to obtain a reversible heat-reflective fog seal layer.

[0082] Example 4:

[0083] This embodiment provides a fog seal layer material with reversible heat reflection function, and its components include a moisture-curing polyurethane material, 0.9 g of wetting and dispersing agent, 9 g of heat-reflective powder, and 100 ml of alcohol solvent, where:

[0084] The moisture-curing polyurethane material is a one-component polyurethane material, which is composed of the following components: 260 g of aliphatic diisocyanate monomer, 600 g of polyether polyol, 180 g of plasticizer, 0.4 g of catalyst, 18 g of foam stabilizer, 50 g of chain extender, and 32 g of crosslinking agent;

[0085] The heat-reflective powder is VO2 nano powder doped with 1.5% tungsten in the M phase, and the particle size is 200 nanometers.

[0086] In this embodiment, the aliphatic diisocyanate monomer is selected as dicyclohexylmethane diisocyanate, the polyether polyol is selected as polyoxypropylene glycol, the plasticizer is selected as dioctyl epoxy tetrahydrophthalate, the catalyst is selected as bismuth isooctanoate, the foam stabilizer is selected as silicone surfactant, the chain extender is selected as ethylene glycol, the crosslinking agent is selected as hydroxypropyl acrylate, the wetting and dispersing agent is polyvinylpyrrolidone, and the alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a ratio of 1:1.

[0087] The preparation method of the fog seal layer material described in this embodiment includes the following steps:

[0088] (1) Add 600 g of polyoxypropylene glycol, 50 g of ethylene glycol, and 32 g of hydroxypropyl acrylate to the reaction kettle, heat up to 120 °C, and stir under vacuum for dehydration for 1.5 h; during this process, the vacuum degree is -0.2 Mpa, and the stirring speed is 1000 - 1500 revolutions per minute;

[0089] (2) Cool down to 80 °C, add 260 g of dicyclohexylmethane diisocyanate and 0.4 g of bismuth isooctanoate into the reaction kettle, and keep the temperature for reaction for 3 h under nitrogen protection;

[0090] (3) After using dibutylamine titration to measure that the NCO value reaches 2.6%, cool down to 50 °C, add 18 g of silicone surfactant and 180 g of dioctyl epoxy tetrahydrophthalate, stir for 30 min, and then cool and discharge to obtain the moisture-curing polyurethane material;

[0091] (4) Mix 9 g of tungsten-doped vanadium dioxide nano powder, 0.9 g of polyvinylpyrrolidone with 100 ml of benzyl alcohol-isobutanol solution, and stir and reflux in silicone oil at 120 °C for 2 h to form a composite alcoholate solution of vanadium;

[0092] (5) Cool down to room temperature (21 °C - 25 °C), add 5% acetic acid solution to adjust the pH of the system to 7.0, stir at a speed of 300 revolutions per minute for 10 minutes, then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 h and then discharge to obtain the vanadium oxide sol system;

[0093] (6) Mix 100 g of the moisture-curing polyurethane material obtained in step (3) with 23 g of the vanadium oxide sol obtained in step (5) and stir evenly at room temperature of 21°C - 25°C, then spray it on the surface of the asphalt mixture and let it stand at room temperature for curing for 24 h to obtain a reversible heat-reflective fog seal layer.

[0094] Example Five:

[0095] This example proposes a fog seal layer material with reversible heat-reflective function, and its components include moisture-curing polyurethane material, 0.9 g of wetting and dispersing agent, 9 g of heat-reflective powder, and 100 ml of alcohol solvent, where:

[0096] The moisture-curing polyurethane material is a one-component polyurethane material, which consists of the following components: 260 g of aliphatic diisocyanate monomer, 400 g of polyether polyol, 160 g of plasticizer, 0.7 g of catalyst, 18 g of foam stabilizer, 50 g of chain extender, and 22 g of crosslinking agent;

[0097] The heat-reflective powder is VO2 nano powder doped with 1.5% tungsten in M phase, and the particle size is 200 nanometers.

[0098] In this example, the aliphatic diisocyanate monomer is selected as dicyclohexylmethane diisocyanate, the polyether polyol is selected as polytetrahydrofuran diol, the plasticizer is selected as dioctyl epoxy tetrahydrophthalate, the catalyst is selected as bismuth isooctanoate, the foam stabilizer is selected as silicone surfactant, the chain extender is selected as ethylene glycol, the crosslinking agent is selected as trimethylolbutane, the wetting and dispersing agent is polyvinylpyrrolidone, and the alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a ratio of 1:1.

[0099] The preparation method of the fog seal layer material described in this example includes the following steps:

[0100] (1) Add 400 g of polytetrahydrofuran diol, 50 g of ethylene glycol, and 22 g of trimethylolbutane to the reaction kettle, heat up to 110°C and stir under vacuum for dehydration for 1.5 h; during this process, the vacuum degree is -0.2 Mpa, and the stirring speed is 1000 - 1500 revolutions per minute;

[0101] (2) Cool down to 80°C, add 260 g of dicyclohexylmethane diisocyanate and 0.7 g of bismuth isooctanoate into the reaction kettle, and keep the temperature for reaction for 2.5 h under nitrogen protection;

[0102] (3) After using dibutylamine titration to determine that the NCO value reaches 3.6%, cool down to 50°C, add 18 g of silicone surfactant and 160 g of dioctyl epoxy tetrahydrophthalate, stir for 30 min and then cool and discharge to obtain the moisture-curing polyurethane material;

[0103] (4) Mix 9 g of tungsten-doped vanadium dioxide nanopowder, 0.9 g of polyvinylpyrrolidone with 100 ml of benzyl alcohol-isobutanol solution, and stir and reflux in silicone oil at 120 °C for 2 h to form a composite alkoxide solution of vanadium;

[0104] (5) Cool down to room temperature of 21 °C - 25 °C, add 5% acetic acid solution to adjust the pH of the system to 7.0, stir at a speed of 300 revolutions per minute for 10 minutes, then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 h before discharging to obtain a vanadium oxide sol system;

[0105] (6) Mix 100 g of the wet-cured polyurethane material obtained in step (3) with 23 g of the vanadium oxide sol obtained in step (5) at room temperature of 21 °C - 25 °C, stir evenly, spray it on the surface of the asphalt mixture, and let it stand and cure at room temperature for 24 h to obtain a reversible heat-reflective fog seal layer.

[0106] For the fog seal layer materials prepared in Example 1, Example 2, Example 3, Example 4, and Example 5, taking "spray 100 g of the wet-cured polyurethane material prepared in steps (1)-(3) of Example 1 on the surface of the asphalt mixture, let it stand and cure at room temperature for 24 h to obtain a polyurethane fog seal layer" in Example 1 as the comparative example, at the same time, conduct relevant performance tests with a traditional emulsified asphalt-based fog seal layer material of a certain brand, and the results are shown in Table 1 below.

[0107] Table 1 Performance comparison of fog seal layer materials

[0108]

[0109] It can be seen from the data of the five examples and one comparative example that the addition of nano-vanadium oxide sol has a slight negative impact on the peel strength of the one-component polyurethane material, but has no significant change on other key performance indicators of the fog seal layer; in terms of longitudinal comparison, the polyurethane-based fog seal layer material is superior to the traditional emulsified asphalt-based fog seal layer material in terms of bond strength and water permeability coefficient. Although the anti-slip performance is slightly inferior, it also meets the standard requirements of relevant specifications.

[0110] Subsequently, the reflectivity of the fog seal layers of Example 1 and the comparative example was detected, as shown in Figure 1 , and the results show that in the wavelength range of 300 - 2500, the response characteristics of the thermal reflectivity with temperature change are related to the wavelength: in the visible light region of 380 - 600 nm, the reflectivity of the fog seal layer material in Example 1 is not much different under high temperature and normal temperature conditions, while in the infrared region of 880 - 2500 nm, when the temperature rises above 38 °C, the reflectivity increases significantly, and the reflection intensity has a difference of 20% - 40% compared with that at normal temperature; compared with the fog seal layer material without vanadium oxide in the comparative example, Example 1 has an obvious thermal reflection effect mechanism.

[0111] Perform summer heat insulation / winter heat preservation simulation on the reversible heat-reflective fog seal layer in Example 3 and the emulsified asphalt-based fog seal layer of a certain brand for traditional pavement maintenance. Place the mixture specimens sprayed with different fog seal layer materials outdoors to receive solar radiation, and measure and record the changes in the road surface temperature of the specimens at fixed time intervals. The results are shown in Table 2 below.

[0112] Table 2 Changes in Road Surface Temperature

[0113]

[0114] The experimental results show that compared with the traditional emulsified asphalt-based fog seal layer materials, the reversible heat-reflective fog seal layer can reduce the average temperature of the asphalt pavement by about 7.6 °C in summer and increase the average temperature of the asphalt pavement by about 4.3 °C in winter, improving the heat storage characteristics of the asphalt pavement to a certain extent. This technology provides a new method for asphalt pavement maintenance, which is beneficial to extending the service life of asphalt pavements and improving the performance of asphalt pavements.

[0115] In summary, by using a fog seal layer material with reversible heat-reflective function and its preparation method of the present invention, the characteristics of spontaneous reversible semiconductor-metal phase transition of M-phase VO2 near 305K are utilized to cause changes in optical properties. When the temperature is lower than 305K, the fog seal layer material has a high near-infrared transmittance, and the transmittance can reach more than 75%, which is beneficial to maintaining the road surface temperature in the low-temperature state; when the temperature is higher than 305K, more visible light in the near-infrared band will be reflected, helping to reduce the absorption of heat radiation by the road surface.

[0116] The above specific application examples have elaborated in detail the principle and implementation manner of the present invention. These examples are only used to help understand the core technical content of the present invention. Based on the above specific embodiments of the present invention, any improvements and modifications made by those skilled in the art of this technology without departing from the principle of the present invention shall fall within the scope of patent protection of the present invention.

Claims

1. A fog seal layer material with reversible heat reflection function, characterized in that, Its components and parts by weight are as follows: 60 - 77 parts of moisture - curable polyurethane material, 0.04 - 0.12 parts of wetting and dispersing agent, 0.4 - 1.2 parts of heat - reflective powder, and 12 - 24 parts of alcohol solvent; Among them, the heat - reflective powder is VO₂ nano - powder doped with 1.5% tungsten in the M phase, and the particle size is 200 nanometers; The moisture - curable polyurethane material is a one - component polyurethane material, which is composed of the following components: 15 - 18 parts of aliphatic diisocyanate monomer, 38 - 42 parts of polyether polyol, 5 - 34 parts of plasticizer, 0.04 - 0.08 parts of catalyst, 1 - 1.5 parts of foam stabilizer, 7 - 12 parts of chain extender, and 2 - 6 parts of cross - linker.

2. The fog seal layer material with reversible heat reflection function according to claim 1, characterized in that, The aliphatic diisocyanate monomer is a composition of one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; The polyether polyol is a composition of one or more of polytetrahydrofuran diol, polypropylene oxide ether diol, and polypropylene glycol; The plasticizer is selected as dioctyl epoxy tetrahydrophthalate; The catalyst is selected as dibutyltin dilaurate, tin octoate, or bismuth octoate; The foam stabilizer is selected as silicone surfactant; The chain extender is selected as ethylene glycol, 2 - methyl - 1,3 - propanediol, or 1,4 - butanediol; The cross - linker is selected as trimethylolbutane, hydroxypropyl acrylate, or N - hydroxymethyl acrylamide.

3. A fog seal layer material with reversible heat reflection function according to claim 1, characterized in that, The wetting and dispersing agent is polyvinylpyrrolidone.

4. A fog seal layer material with reversible heat reflection function according to claim 1, characterized in that, The alcohol solvent is a benzyl alcohol - isobutanol solution mixed in a 1:1 ratio.

5. A preparation method of a fog seal layer material with reversible heat reflection function, characterized in that, The components and parts by weight of the fog seal layer material are as follows: 60 - 77 parts of moisture - curable polyurethane material, 0.04 - 0.12 parts of wetting and dispersing agent, 0.4 - 1.2 parts of heat - reflective powder, and 12 - 24 parts of alcohol solvent. Among them, the heat - reflective powder is VO₂ nano - powder doped with 1.5% tungsten in the M phase, and the particle size is 200 nanometers. The moisture - curable polyurethane material is a one - component polyurethane material, which is composed of the following components: 15 - 18 parts of aliphatic diisocyanate monomer, 38 - 42 parts of polyether polyol, 5 - 34 parts of plasticizer, 0.04 - 0.08 parts of catalyst, 1 - 1.5 parts of foam stabilizer, 7 - 12 parts of chain extender, and 2 - 6 parts of cross - linker; The preparation process of the fog seal layer material includes: (1) Add polyether polyol, chain extender, and cross - linker into the reaction kettle, heat up to 110 °C, and stir under vacuum for 1 h to dehydrate; (2) Cool down to 80 °C, and dropwise add aliphatic diisocyanate monomer and catalyst into the reaction kettle according to the measurement, and keep the temperature for reaction for 1.5 - 3 h; (3) Cool down to 50 °C, add foam stabilizer and plasticizer, stir at a speed of 500 - 800 revolutions per minute for 30 min, and then discharge to obtain the moisture - curable polyurethane material; (4) Mix the heat - reflective powder, wetting and dispersing agent, and alcohol solvent, stir and reflux in silicone oil at 100 °C - 120 °C for 1.5 - 2 h to form a vanadium composite alcoholate solution; (5) Cool down to room temperature, add 5% acetic acid solution to adjust the pH to neutral, stir at a speed of 300 revolutions per minute for 10 minutes, then gradually reduce the speed to 150 revolutions per minute, and continue to stir for 1 - 2 h and then discharge to obtain the vanadium oxide sol system; (6) Mix and stir the moisture-curing polyurethane material obtained in step (3) with the vanadium oxide sol obtained in step (5) at room temperature to obtain a fog seal layer material with reversible heat reflection function.

6. The preparation method of a fog seal layer material with reversible heat reflection function according to claim 5, characterized in that, Perform step (1) with a vacuum degree of -0.2 Mpa and a stirring speed of 1000 - 1500 revolutions per minute.

7. A method for preparing a fog seal layer material with reversible heat reflection function according to claim 5, characterized in that, The room temperature in steps (5) and (6) is 21°C - 25°C.

8. The preparation method of a fog seal layer material with reversible heat reflection function according to claim 5, characterized in that, The aliphatic diisocyanate monomer is a composition of one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; The polyether polyol is a composition of one or more of polytetrahydrofuran diol, polypropylene oxide ether diol, and polyoxypropylene diol; The plasticizer is selected as dioctyl epoxy tetrahydrophthalate; The catalyst is selected as dibutyltin dilaurate, tin octoate, or bismuth octoate; The foam stabilizer is selected as silicone surfactant; The chain extender is selected as ethylene glycol, 2-methyl-1,3-propanediol, or 1,4-butanediol; The crosslinking agent is selected as trimethylolbutane, hydroxypropyl acrylate, or N-methylolacrylamide; The wetting and dispersing agent is polyvinylpyrrolidone; The alcohol solvent is a benzyl alcohol-isobutanol solution mixed in a 1:1 ratio.

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