Asphalt isolation coating and preparation method thereof

Abstract

The invention relates to the technical field of road materials, and particularly discloses an asphalt isolation coating and a preparation method thereof. The asphalt isolation coating is prepared from the following raw materials in parts by weight: 110 to 180 parts of water, 1 to 4 parts of sodium stearate, 30 to 80 parts of glycerol, 30 to 80 parts of vegetable oil, 4 to 12 parts of polyoxyethylene ether sodium sulfonate type surfactant, 30 to 80 parts of simethicone, 5 to 10 parts of inorganic nano filler and 5 to 8 parts of organic stabilizer. The asphalt isolation coating prepared in the invention uses vegetable oil as an oil phase component instead of traditional diesel oil, and does not react with an asphalt mixture and is not consumed; meanwhile, sodium stearate and polyoxyethylene ether sodium sulfonate type surfactants are used for compounding, so that sufficient emulsification of an oil phase and a water phase is promoted, a stable emulsion structure is formed, and the isolation and anti-sticking effects of the coating are improved.

Description

Technical Field

[0001] The present application relates to the technical field of road materials, and in particular to an asphalt isolation coating and a preparation method thereof. Background Art

[0002] In order to prevent the asphalt in the hot asphalt mixture from sticking to the construction equipment, an anti-sticking coating is applied to the surface of the construction equipment in contact with the hot asphalt mixture. The material forms a chemical bond or physical adsorption with the surface of the construction equipment to form a micron-thick, thermally stable film layer on the mold surface, making the substrate surface have a very low surface energy, allowing the finished material to fall off quickly and easily.

[0003] At present, in the process of asphalt mixture construction, a mixture of diesel and water in a ratio of 1:3 is used as an isolation coating for spraying or brushing. This type of isolation material has a significant dissolving effect on the asphalt film, which can easily cause the asphalt film on the road surface to peel off, expose the aggregate on the road surface, and reduce the service life of the asphalt pavement. The watering method is used to prevent the asphalt mixture from adhering to the equipment. A large amount of watering will reduce the surface temperature of the mixture quickly, which is not conducive to the rolling construction of the asphalt pavement. Summary of the invention

[0004] In order to improve the isolation effect of the isolation coating on the asphalt mixture, the present application provides an asphalt isolation coating and a preparation method thereof.

[0005] In the first aspect, the present application provides an asphalt isolation coating, which adopts the following technical solution: An asphalt isolation coating comprises the following raw materials in parts by weight: 110-180 parts of water, 1-4 parts of sodium stearate, 30-80 parts of glycerol, 30-80 parts of vegetable oil, 4-12 parts of sodium polyoxyethylene ether sulfonate surfactant, 30-80 parts of dimethyl silicone oil, 5-10 parts of inorganic nanofiller and 5-8 parts of organic stabilizer.

[0006] By adopting the above technical scheme, vegetable oil is used as an oil phase component to provide lubricity and film-forming properties of the coating, while not reacting and consuming with the asphalt mixture, which promotes the shedding of the asphalt. The fatty acids in the vegetable oil can interact with sodium stearate and sodium polyoxyethylene ether sulfonate surfactants to form a stable emulsion structure, and form a coating with an isolation effect after the asphalt mixture is constructed. Sodium stearate and sodium polyoxyethylene ether sulfonate surfactants are compounded with each other to help emulsify the oil phase and the water phase, stabilize the oil-water interface, and improve the isolation effect of the coating. Glycerin can increase the flexibility and adhesion of the isolation coating, reduce the adhesion of the asphalt mixture, and enhance the stability of the isolation coating. Nanofillers enhance the density of the coating by filling the tiny gaps in the coating. The low surface area of ​​dimethyl silicone oil can promote the formation of a thin layer on the coating surface, and promote the isolation coating to form a dense and stable isolation film, achieving a better isolation and anti-sticking effect.

[0007] Preferably, the sodium polyoxyethylene ether sulfonate surfactant is one of sodium fatty alcohol polyoxyethylene ether sulfonate and sodium cardanol polyoxyethylene ether sulfonate.

[0008] By adopting the above technical solution, sodium fatty alcohol polyoxyethylene ether sulfonate and sodium cardanol polyoxyethylene ether sulfonate can reduce the surface tension of the oil-water interface in the oil phase, promote the emulsification of the oil phase and the water phase, form a stable emulsion structure, and improve the stability and uniformity of the coating. Compared with some other surfactants, sodium fatty alcohol polyoxyethylene ether sulfonate and sodium cardanol polyoxyethylene ether sulfonate are not easy to form precipitation with calcium and magnesium ions, thereby reducing the reaction with asphalt mixtures and improving the isolation and protection effect of the coating on asphalt mixtures.

[0009] Preferably, the inorganic nanofiller is at least one of silicon dioxide, zeolite, talc and graphite.

[0010] Preferably, the inorganic nanofiller is pre-modified, and the modification method comprises the following specific steps: The inorganic nanofiller is dispersed in a mixture of cyclohexane, sodium p-toluenesulfonate, a silane coupling agent, and octyltrimethoxysilane, and the temperature is raised to 75-85°C and refluxed for 3-4 hours, washed and dried to obtain a pretreated inorganic nanofiller, the pretreated inorganic nanofiller is mixed with a hydrogen peroxide solution, heated to 35-45°C and stirred for reaction, after the reaction, the inorganic nanofiller particles are washed and dried, and then the inorganic nanofiller particles are mixed with a sulfuric acid solution for reaction to obtain a modified inorganic nanofiller.

[0011] By adopting the above technical scheme, by carrying out alkyl sulfonic acid-alkyl modification in the inorganic nanofiller and carrying out organic-inorganic hybridization on the inorganic nanofiller, the amphiphilicity of the inorganic nanofiller can be adjusted, thereby improving the stability of the inorganic nanofiller in the isolation coating, thereby improving the wear resistance, rheology and film-forming effect of the coating.

[0012] Preferably, the mass ratio of the inorganic nanofiller to cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane is 1:(0.1-0.3):(0.1-0.3):(0.3-0.5), and the mass ratio of the pretreated inorganic nanofiller to hydrogen peroxide solution and sulfuric acid solution is 1:(55-65):(55-65).

[0013] Preferably, the organic stabilizer is at least one of xanthan gum, gelatin, agar and sodium alginate.

[0014] By adopting the above technical scheme, xanthan gum, gelatin, agar and sodium alginate have good film-forming and thickening effects, so that the coating has better adhesion and stability during construction. In the coating system, xanthan gum molecules and agar molecules can interact through hydrogen bonds and van der Waals forces to form a three-dimensional network structure, thereby increasing the viscosity and stability of the coating. Under the action of shear force, this network structure can be temporarily broken, reducing the viscosity of the coating and facilitating the coating construction; when the shear force disappears, the network structure will recover and improve the stability of the coating. Gelatin and sodium alginate can increase the viscosity of the isolation coating, improve the rheological properties of the isolation coating, and enable the isolation coating to have better adhesion and film-forming properties during construction.

[0015] Preferably, the stabilizer is pre-modified with cholesterol, and the modification method comprises the following specific steps: mixing the stabilizer with an organic solvent, heating the solution to 40-45°C and stirring to obtain a stabilizer solution, cooling the solution to 33-38°C, adding a cholesterol-chloroform solution to the stabilizer solution, mixing N,N-dicyclohexylcarbodiimide and 4-dimethylaminopyridine with organic solvents respectively and adding them to the stabilizer solution, reacting at 33-38°C, adding anhydrous ethanol to precipitate the product, drying the product after centrifugation to obtain a stabilizer complex, mixing the stabilizer complex with water and allowing it to stand to form a stabilizer complex solution, adjusting the pH of the stabilizer complex solution to be neutral, using ethanol for precipitation, centrifuging and drying the product to obtain a modified stabilizer.

[0016] By adopting the above technical scheme, cholesterol is grafted onto the surface of the stabilizer, which can reduce the hydrophilicity of the stabilizer, and can promote the contact angle of the stabilizer in the coating system to be close to 90°. It can have good hydrophilic and lipophilic abilities, and can improve the stability of the isolation material system. At the same time, it can also promote the inorganic nanofiller and surfactant to be evenly and stably dispersed in the isolation coating system, thereby reducing the stratification and precipitation of the isolation coating.

[0017] Preferably, the mass ratio of the stabilizer, the organic solvent, the cholesterol-chloroform solution, the N,N-dicyclohexylcarbodiimide and the 4-dimethylaminopyridine is 1:(45-55):(1-1.5):(0.1-0.3):(0.1-0.3).

[0018] In a second aspect, the present application provides a method for preparing an asphalt isolation coating, using the following technical solution: A method for preparing an asphalt isolation coating comprises the following specific steps: mixing water, sodium stearate, glycerin and vegetable oil, heating to 60-80°C and stirring evenly, then adding sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, inorganic nanofiller and organic stabilizer, stirring evenly and emulsifying to obtain an asphalt isolation coating.

[0019] By adopting the above technical scheme, water, sodium stearate, glycerin and vegetable oil are first mixed and pre-emulsified, and then sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, inorganic nanofiller and organic stabilizer are added to emulsify the water phase and oil phase, so that the prepared asphalt isolation coating has good stability, can be stored for a long time without stratification, and can evenly form a dense isolation film on the surface of the construction substrate.

[0020] In summary, this application has the following beneficial effects: 1. Since the present application uses vegetable oil as the oil phase component, the reaction consumption of the asphalt mixture is reduced, and the sodium stearate and polyoxyethylene ether sodium sulfonate surfactants are compounded to promote the full emulsification of the oil phase and the water phase, forming a stable emulsion structure and forming a firm and uniform isolation film on the surface of the substrate. The inorganic nanofiller can enhance the density of the coating, and the glycerol can increase the flexibility and adhesion of the isolation coating, reduce the adhesion of the coating, and improve the isolation effect of the coating.

[0021] 2. In this application, silica powder, zeolite powder, talcum powder and graphite powder are used as inorganic nanofillers and added to the coating system. At the same time, the inorganic nanofillers are organic-inorganic hybridized to adjust the amphiphilicity of the inorganic nanofillers and improve the stability of the inorganic nanofillers in the isolation coating. DETAILED DESCRIPTION

[0022] The present application is further described in detail below with reference to the embodiments.

[0023] All raw materials in the examples are commercially available. Example

[0024] Example 1 This embodiment provides an asphalt isolation coating, comprising the following raw materials in parts by weight: 145 kg of water, 2 kg of sodium stearate, 55 kg of glycerol, 55 kg of vegetable oil, 8 kg of sodium polyoxyethylene ether sulfonate surfactant, 55 kg of dimethyl silicone oil, 8 kg of inorganic nanofiller, and 7 kg of organic stabilizer. The sodium polyoxyethylene ether sulfonate surfactant is fatty alcohol sodium polyoxyethylene ether sulfonate, the inorganic nanofiller is silicon dioxide, the average particle size of the inorganic nanofiller is 50-100 nm, and the organic stabilizer is sodium alginate.

[0025] The preparation method of asphalt isolation coating comprises the following specific steps: Mix water, sodium stearate, glycerin and vegetable oil, heat to 70°C and stir evenly, then add sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, inorganic nanofiller and organic stabilizer, stir evenly and emulsify to obtain asphalt isolation coating.

[0026] Example 2 The difference between Example 2 and Example 1 is that the amount of water used in the asphalt isolation coating raw material is 110 kg, the amount of sodium stearate used is 1 kg, the amount of glycerol used is 30 kg, the amount of vegetable oil used is 30 kg, the amount of sodium polyoxyethylene ether sulfonate type surfactant used is 4 kg, the amount of dimethyl silicone oil used is 30 kg, the amount of inorganic nanofiller used is 5 kg, and the amount of organic stabilizer used is 5 kg.

[0027] Example 3 The difference between Example 3 and Example 1 is that the amount of water used in the asphalt isolation coating raw material is 180 kg, the amount of sodium stearate used is 4 kg, the amount of glycerol used is 80 kg, the amount of vegetable oil used is 80 kg, the amount of sodium polyoxyethylene ether sulfonate type surfactant used is 12 kg, the amount of dimethyl silicone oil used is 80 kg, the amount of inorganic nanofiller used is 10 kg, and the amount of organic stabilizer used is 8 kg.

[0028] Example 4 The difference between Example 4 and Example 1 is that the sodium polyoxyethylene ether sulfonate type surfactant in the raw material of the asphalt isolation coating is sodium polyoxyethylene ether sulfonate of cardanol.

[0029] Example 5 The difference between Example 5 and Example 1 is that the inorganic nanofiller in the raw material of the asphalt isolation coating is a mixture of silica, graphite, zeolite and talc, wherein the mass ratio of silica, graphite, zeolite and talc is 1:1:1:1.

[0030] Example 6 The difference between Example 6 and Example 5 is that the inorganic nanofiller in the raw material of the asphalt isolation coating is modified in advance.

[0031] The preparation method of asphalt isolation coating comprises the following specific steps: S1: Disperse the inorganic nanofiller in a mixture of cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane, wherein the mass ratio of the inorganic nanofiller to cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane is 1:0.2:0.2:0.4, heat to 80°C and reflux for 3.5 hours, wash and dry to obtain the pretreated inorganic nanofiller, mix the pretreated inorganic nanofiller with a 30% aqueous hydrogen peroxide solution, wherein the mass ratio of the pretreated inorganic nanofiller to the hydrogen peroxide solution is 1:60, heat to 40°C and stir to react for 24 hours, wash and dry the inorganic nanofiller particles after the reaction, then mix the inorganic nanofiller particles with a 0.8 mol / L aqueous sulfuric acid solution for reaction for 24 hours, wherein the mass ratio of the inorganic nanofiller particles to the aqueous sulfuric acid solution is 1:60, filter, wash, and dry to obtain the modified inorganic nanofiller.

[0032] S2: Mix water, sodium stearate, glycerin and vegetable oil, heat to 70°C and stir evenly, then add sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, modified inorganic nanofiller and organic stabilizer, stir evenly and emulsify to obtain asphalt isolation coating.

[0033] Example 7 The difference between Example 7 and Example 6 is that the mass ratio of inorganic nanofiller to cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane in the asphalt isolation coating raw materials is 1:0.1:0.3:0.3, and the mass ratio of the pretreated inorganic nanofiller to hydrogen peroxide solution and sulfuric acid solution is 1:55:65, respectively.

[0034] Example 8 The difference between Example 8 and Example 6 is that the stabilizer in the raw materials of the asphalt isolation coating is a mixture of xanthan gum, gelatin, agar and sodium alginate, and the mass ratio of xanthan gum, gelatin, agar and sodium alginate is 1:1:1:1.

[0035] Example 9 The difference between Example 9 and Example 8 is that the stabilizer in the raw material of the asphalt isolation coating is pre-modified with cholesterol.

[0036] The preparation method of asphalt isolation coating comprises the following specific steps: S1: Disperse the inorganic nanofiller in a mixture of cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane, wherein the mass ratio of the inorganic nanofiller to cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane is 1:0.2:0.2:0.4, heat to 80°C and reflux for 3.5 hours, wash and dry to obtain the pretreated inorganic nanofiller, mix the pretreated inorganic nanofiller with a 30% aqueous hydrogen peroxide solution, wherein the mass ratio of the pretreated inorganic nanofiller to the hydrogen peroxide solution is 1:60, heat to 40°C and stir to react for 24 hours, wash and dry the inorganic nanofiller particles after the reaction, then mix the inorganic nanofiller particles with a 0.8 mol / L aqueous sulfuric acid solution for reaction for 24 hours, wherein the mass ratio of the inorganic nanofiller particles to the aqueous sulfuric acid solution is 1:60, filter, wash, and dry to obtain the modified inorganic nanofiller.

[0037] S2: Mix the stabilizer with the organic solvent dimethyl sulfoxide, the mass ratio of the stabilizer to the organic solvent is 1:40, heat to 43°C and stir to dissolve to obtain a stabilizer solution, cool to 35°C, add a 20% cholesterol-chloroform solution by mass fraction to the stabilizer solution, the mass ratio of the stabilizer to the cholesterol-chloroform solution is 1:1.3, mix N,N-dicyclohexylcarbodiimide and 4-dimethylaminopyridine with the organic solvent dimethyl sulfoxide respectively and add them to the stabilizer solution, N,N-dicyclohexylcarbodiimide, 4-dimethylaminopyridine The mass ratio of pyridine, organic solvent and stabilizer is 0.2:0.2:10:1, and the reaction is carried out at 35°C for 24 hours to obtain a reaction solution, and anhydrous ethanol with a volume of 5 times the reaction solution is added dropwise to precipitate a product. The product is dried after centrifugation to obtain a stabilizer complex; the stabilizer complex is mixed with water and allowed to stand, and the mass ratio of the stabilizer complex to water is 1:2 to form a stabilizer complex solution, and a sodium bicarbonate aqueous solution with a mass fraction of 4% is used to adjust the pH of the stabilizer complex solution to neutral, and ethanol is used for precipitation. The product is centrifuged and dried to obtain a modified organic stabilizer.

[0038] S3: Mix water, sodium stearate, glycerin and vegetable oil, heat to 70°C and stir evenly, then add sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, modified inorganic nanofiller and modified organic stabilizer, stir evenly and emulsify to obtain asphalt isolation coating.

[0039] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the asphalt isolation coating does not use a sodium polyoxyethylene ether sulfonate type surfactant.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that sodium stearate is not used in the asphalt isolation coating.

[0041] Performance testing The following performance tests were conducted on the asphalt isolation coatings provided in Examples 1-9 and Comparative Examples 1-2 of the present application, and the specific test results are shown in Table 1.

[0042] Detection Methods 1. Viscosity test The viscosity of the asphalt isolation coating prepared in this application was tested with reference to the standard of GB / T 10247-2008 "Viscosity Measurement Method".

[0043] 2. Storage stability The asphalt isolation coating prepared in the present application is stored in a cool place away from light for 30 days, and its stratification and precipitation phenomena are observed. If no stratification or precipitation phenomena occur, it is qualified, otherwise it is unqualified.

[0044] 3. Film-forming effect The asphalt isolation coating prepared in the present application is brushed on an iron plate with a roughness of about ra6.3, and the solution aggregation after brushing is used to judge. If no aggregated droplets appear, it is excellent; if a small amount of aggregated droplets appear and the aggregated droplets occupy 1-5% of the film-forming area, it is good; if a large number of aggregated droplets appear and the aggregated droplets occupy more than 6% of the film-forming area, it is poor.

[0045] 4. Isolation Effect The asphalt isolation coating prepared in the present application was applied to four carriage plates for transporting asphalt mixture and on compacting wheels to isolate the asphalt mixture, with a coating thickness of 4 mm, and the isolation effect of the asphalt mixture was observed.

[0046] Table 1: Performance test results data table It can be seen from the performance test results that the asphalt isolation coating prepared in this application has a good isolation and anti-sticking effect. It can be seen from Example 6 that the modification of the inorganic nanofiller can promote the uniform dispersion of the inorganic nanofiller in the coating system, improve the density of the coating, and reduce the stratification of the coating. By comparing Comparative Examples 1-2 with Example 1, it can be seen that the sodium stearate and polyoxyethylene ether sodium sulfonate surfactants synergistically enhance the effect and can fully emulsify and disperse the water phase and the oil phase to form a stable emulsion structure. The lack of any component will affect the isolation and anti-sticking effect of the coating.

[0047] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An asphalt isolation coating, characterized in that: The invention comprises the following raw materials in parts by weight: 110-180 parts of water, 1-4 parts of sodium stearate, 30-80 parts of glycerol, 30-80 parts of vegetable oil, 4-12 parts of sodium polyoxyethylene ether sulfonate surfactant, 30-80 parts of dimethyl silicone oil, 5-10 parts of inorganic nano filler and 5-8 parts of organic stabilizer.

2. The asphalt isolation coating according to claim 1, characterized in that: The sodium polyoxyethylene ether sulfonate surfactant is one of sodium polyoxyethylene fatty alcohol ether sulfonate and sodium polyoxyethylene cardanol ether sulfonate.

3. The asphalt isolation coating according to claim 1, characterized in that: The inorganic nano filler is at least one of silicon dioxide, zeolite, talc and graphite.

4. The asphalt isolation coating according to claim 3, characterized in that: The inorganic nanofiller is modified in advance, and the modification method comprises the following specific steps: The inorganic nanofiller is dispersed in a mixture of cyclohexane, sodium p-toluenesulfonate, a silane coupling agent, and octyltrimethoxysilane, and the temperature is raised to 75-85°C and refluxed for 3-4 hours, washed and dried to obtain a pretreated inorganic nanofiller, the pretreated inorganic nanofiller is mixed with a hydrogen peroxide solution, heated to 35-45°C and stirred for reaction, after the reaction, the inorganic nanofiller particles are washed and dried, and then the inorganic nanofiller particles are mixed with a sulfuric acid solution for reaction to obtain a modified inorganic nanofiller.

5. The asphalt isolation coating according to claim 4, characterized in that: The mass ratio of the inorganic nanofiller to cyclohexane, sodium p-toluenesulfonate, silane coupling agent, and octyltrimethoxysilane is 1: (0.1-0.3): (0.1-0.3): (0.3-0.5), and the mass ratio of the pretreated inorganic nanofiller to hydrogen peroxide solution and sulfuric acid solution is 1: (55-65): (55-65).

6. The asphalt isolation coating according to claim 1, characterized in that: The organic stabilizer is at least one of xanthan gum, gelatin, agar and sodium alginate.

7. The asphalt isolation coating according to claim 4, characterized in that: The stabilizer is pre-modified with cholesterol, and the modification method comprises the following specific steps: The stabilizer is mixed with an organic solvent, heated to 40-45° C. and stirred to obtain a stabilizer solution, cooled to 33-38° C., a cholesterol-chloroform solution is added to the stabilizer solution, N,N-dicyclohexylcarbodiimide and 4-dimethylaminopyridine are respectively mixed with an organic solvent and added to the stabilizer solution, reacted at 33-38° C., anhydrous ethanol is added dropwise to precipitate a product, the product is dried after centrifugation to obtain a stabilizer complex, the stabilizer complex is mixed with water and allowed to stand to form a stabilizer complex solution, the pH of the stabilizer complex solution is adjusted to be neutral, ethanol is used for precipitation, the product is centrifuged and dried to obtain a modified stabilizer.

8. The asphalt isolation coating according to claim 5, characterized in that: The mass ratio of the stabilizer, the total amount of the organic solvent, the cholesterol-chloroform solution, the N,N-dicyclohexylcarbodiimide and the 4-dimethylaminopyridine is 1:(45-55):(1-1.5):(0.1-0.3):(0.1-0.3).

9. A method for preparing the asphalt isolation coating according to any one of claims 1 to 8, characterized in that: The method comprises the following specific steps: mixing water, sodium stearate, glycerin and vegetable oil, heating to 60-80°C and stirring evenly, then adding sodium polyoxyethylene ether sulfonate surfactant, dimethyl silicone oil, inorganic nanofiller and organic stabilizer, stirring evenly and emulsifying to obtain asphalt isolation coating.

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