Preparation method of RS composite latex

Abstract

The invention discloses a preparation method of RS composite latex, and relates to the technical field of composite latex, and the preparation method comprises the following steps: preparing the RS composite latex from the following components in parts by weight: 30-70 parts of SBS latex and 30-70 parts of SBR latex; the preparation method comprises the following steps: 1) preparing SBS latex: mixing linear SBS particles and a solvent, adding the mixture into a four-neck flask, heating and stirring for a period of time, adding an additive and an emulsifier, and performing reduced pressure distillation to obtain the SBS latex; 2) preparing RS composite latex: mixing SBS latex and SBR latex, uniformly stirring, and standing for a period of time at a constant temperature to obtain stable RS composite latex; the raw materials adopted by the invention are common industrial products and are easy to obtain. The RS composite latex modified asphalt obtained by adopting a mode of mechanically mixing the SBS latex and the SBR latex is stable, not easy to demulsify, small in latex particle size, high in tensile strength and elongation after film formation, simple in preparation process, low in cost, safe, environment-friendly, convenient to use, wide in application range and very good in application prospect, and meanwhile, the high and low temperature performance of emulsified asphalt is considered.

Description

Technical Field

[0001] The invention relates to the technical field of composite latex, and more specifically to a method for preparing RS composite latex. Background Art

[0002] By the end of 2018, my country's highway mileage had reached 4.8465 million kilometers, with a maintenance rate of up to 98%; the excellent rates of my country's main trunk roads (expressways, ordinary national roads, ordinary provincial roads, and rural roads) reached 99.6%, 89%, 86% and 60% respectively. Emulsified asphalt has an important impact on the road performance of the micro-surfacing mixture after paving. Emulsified asphalt has the advantages of cold construction, enhanced adhesion between asphalt and aggregate, uniform mixing, saving raw materials, and reducing environmental pollution. Emulsified asphalt mixtures generally have defects such as insufficient adhesion of the mixture, poor water stability, low early strength, and poor late strength. The emergence of modified emulsified asphalt has greatly improved this problem, that is, by modifying the emulsified asphalt to improve road performance. The most widely used modifier in modified emulsified asphalt is styrene-butadiene rubber (SBR) latex. SBR latex prepared by emulsion polymerization greatly reduces the difficulty of preparing modified emulsified asphalt and improves the performance of emulsified asphalt. SBR latex increases the ductility of asphalt pavement, which makes the pavement more flexible and crack-resistant at low temperatures, but the high-temperature performance of SBR modified asphalt is defective, that is, in high-temperature areas, as the traffic load increases, the pavement is severely deformed, which greatly limits the application of SBR modified asphalt in different climates and regions. SBS modifier has a good improvement effect on the high and low temperature properties of asphalt, so it is most widely used in modified asphalt, but its application in modified emulsified asphalt is limited. This is mainly because the preparation of SBS modified emulsified asphalt is generally obtained by first modifying and then emulsifying, and the viscosity of SBS modified asphalt is relatively large, which increases the difficulty of emulsification and limits the application of SBS in modified emulsified asphalt. Therefore, in order to solve the problems of the above-mentioned SBS and SBR latex, this patent obtains RS composite latex after mechanically mixing SBS latex and SBR latex in a certain proportion. Summary of the invention

[0003] The purpose of the present invention is to solve the above technical problems and provide a method for preparing RS composite latex.

[0004] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: A method for preparing RS composite latex comprises the following steps: RS composite latex is composed of the following parts by weight: 30-70 parts of SBS latex and 30-70 parts of SBR latex; To prepare SBS latex, linear SBS particles and a solvent are mixed and added into a four-necked flask, and additives and emulsifiers are added after heating and stirring for a period of time, and SBS latex is obtained after reduced pressure distillation; 2) Preparation of RS composite latex: SBS latex and SBR latex are mixed and stirred evenly, and then allowed to stand at a constant temperature for a period of time to obtain a stable RS composite latex.

[0005] The solvent in step 1) includes one or a combination of two or more of deionized water, toluene, n-butane, n-pentane, and n-hexane.

[0006] The additive in step 1) is a compound of polyethylene glycol, tributyl phosphate and polyacrylamide.

[0007] The mass ratio of the polyethylene glycol, tributyl phosphate and polyacrylamide is 4:1:1-7:1:1.

[0008] In the step 1), the pressure of the reduced pressure distillation is 1-4 Kpa and the temperature is 120-150°C.

[0009] The weight proportion of the emulsifier is 2 to 5 parts.

[0010] The emulsifier is prepared by compounding alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid.

[0011] The mass ratio of the alkylphenol polyoxyethylene ether, the fatty alcohol polyoxyethylene ether phosphate, and the polymerized carboxylate polyacrylic acid is 6:2:1-2:2:1.

[0012] In the step 2), the stirring speed is 200-400 r·min-1.

[0013] In the step 2), the standing temperature is 20-50° C. and the standing time is 2-4 days.

[0014] The beneficial effects of the present invention are as follows: 1. The raw materials used in the present invention are all common industrial products and are easily available.

[0015] 2. The RS composite latex modified asphalt obtained by mechanically mixing SBS latex and SBR latex in the present invention is stable and not easy to demulsify, the latex particles have a small particle size, and the tensile strength and elongation after film formation are high. The preparation process is simple, the cost is low, and it is safe, environmentally friendly, and easy to use. At the same time, the high and low temperature performance of emulsified asphalt is taken into account, the adaptability is wide, and there is a good application prospect. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Generally, the components of the embodiments of the present invention can be arranged and designed in various different configurations.

[0017] Therefore, the detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0018] A method for preparing RS composite latex comprises the following steps: Weigh 70 parts of SBS latex and 30 parts of SBR latex; 1) Prepare SBS latex by mixing linear SBS particles and solvent and adding them into a four-necked flask, adding additives and emulsifiers after heating and stirring for a period of time, and obtaining SBS latex after vacuum distillation; Among them, the mass ratio of linear SBS particles, solvent, additive, and emulsifier is 10:1:0.3:0.3; The additive is a compound of polyethylene glycol, tributyl phosphate and polyacrylamide, and the mass ratio of polyethylene glycol, tributyl phosphate and polyacrylamide is 5:1:1; The emulsifier is a compound of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid, wherein the mass ratio of the alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid is 4:2:1; 2) Preparation of RS composite latex: 70 parts of SBS latex and 30 parts of SBR latex were weighed and mixed, stirred at 200 r / min, and allowed to stand at a constant temperature of 40°C for 2 days to obtain a stable RS composite latex; According to the mass ratio of RS composite latex to 90# base asphalt of 1:21, RS composite latex was added to the emulsified asphalt soap solution, and the modified emulsified asphalt was obtained after sufficient mixing and strong shearing and emulsification. Example 2

[0019] A method for preparing RS composite latex comprises the following steps: Weigh 50 parts of SBS latex and 50 parts of SBR latex; 1) Prepare SBS latex by mixing linear SBS particles and solvent and adding them into a four-necked flask, adding additives and emulsifiers after heating and stirring for a period of time, and obtaining SBS latex after vacuum distillation; Among them, the mass ratio of linear SBS particles, solvent, additive, and emulsifier is 10:1:0.3:0.3; The additive is a compound of polyethylene glycol, tributyl phosphate and polyacrylamide, and the mass ratio of polyethylene glycol, tributyl phosphate and polyacrylamide is 5:1:1; The emulsifier is a compound of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid, wherein the mass ratio of the alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid is 4:2:1; 2) Preparation of RS composite latex: Weigh 50 parts of SBS latex and 50 parts of SBR latex, mix them and stir them at 300 r / min, and let them stand at a constant temperature of 20°C for 3 days to obtain a stable RS composite latex; According to the mass ratio of RS composite latex to 90# base asphalt of 1:21, RS composite latex was added to the emulsified asphalt soap solution, and the modified emulsified asphalt was obtained after sufficient mixing and strong shearing and emulsification. Example 3

[0020] A method for preparing RS composite latex comprises the following steps: Weigh 30 parts of SBS latex and 70 parts of SBR latex; 1) Prepare SBS latex by mixing linear SBS particles and solvent and adding them into a four-necked flask, adding additives and emulsifiers after heating and stirring for a period of time, and obtaining SBS latex after vacuum distillation; Among them, the mass ratio of linear SBS particles, solvent, additive, and emulsifier is 10:1:0.3:0.3; The additive is a compound of polyethylene glycol, tributyl phosphate and polyacrylamide, and the mass ratio of polyethylene glycol, tributyl phosphate and polyacrylamide is 5:1:1; The emulsifier is a compound of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid, wherein the mass ratio of the alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid is 4:2:1; 2) Preparation of RS composite latex: 30 parts of SBS latex and 70 parts of SBR latex were weighed and mixed, stirred at 400 r / min, and allowed to stand at a constant temperature of 30°C for 4 days to obtain a stable RS composite latex; According to the mass ratio of RS composite latex to 90# base asphalt of 1:21, RS composite latex was added to the emulsified asphalt soap solution, and the modified emulsified asphalt was obtained after sufficient mixing and strong shearing and emulsification.

[0021] Comparative Example 1 1) Weigh 100 parts of SBS latex and add it to the emulsified asphalt soap solution at a mass ratio of 1:21 with 90# base asphalt. Mix thoroughly and strongly shear emulsify to obtain modified emulsified asphalt.

[0022] Comparative Example 2 1) Weigh 100 parts of SBR latex, add SBR latex to the emulsified asphalt soap solution at a mass ratio of 3:100, mix thoroughly, and strongly shear and emulsify to obtain modified emulsified asphalt.

[0023] The modified emulsified asphalt (low-temperature evaporation residue) prepared in the examples and comparative examples was placed in a 163°C oven for 60 minutes, stirred and cast into a film, and the following performance tests were performed: (1) Softening point determination.

[0024] (2) Determination of dynamic viscosity at 60°C.

[0025] The modified emulsified asphalt prepared in Examples 1-3 and Comparative Examples 1-2 was used to measure the wet wheel abrasion value of the slurry mixture. The results are shown in Table 1.

[0026] Table 1 Example / Comparative Example Softening point℃ 60℃ dynamic viscosity% Wet wheel abrasion value of slurry mixture g / m2 Example 1 59 20986 178 Example 2 61 21693 159 Example 3 60 20456 184 Comparative Example 1 56 18745 239 Comparative Example 2 52 18356 227 It can be seen from Table 1 that the softening point of the modified emulsified asphalt obtained in Comparative Example 2 is low, and the wet wheel abrasion value of the slurry mixture is large, while the softening point of the modified emulsified asphalt prepared by the present invention is improved, and the wet wheel abrasion value of the slurry mixture is small.

[0027] In the present invention, the additive is a compound of polyethylene glycol, tributyl phosphate, and polyacrylamide, and the emulsifier is a compound of alkylphenol polyoxyethylene ethers, fatty alcohol polyoxyethylene ether phosphates, and polymerized carboxylate polyacrylic acid. The additive and the emulsifier work synergistically, and the RS composite latex obtained by the present invention is used to directly add emulsified asphalt, thereby improving the high-temperature stability of the polymer in the asphalt, greatly improving the softening point temperature of the asphalt, and allowing the asphalt material added with the RS composite latex to not deform at high temperatures, thereby obtaining an emulsified asphalt with high stability.

Claims

1. A method for preparing RS composite latex, characterized in that: The steps include: RS composite latex is composed of the following parts by weight: 30-70 parts of SBS latex and 30-70 parts of SBR latex; To prepare SBS latex, linear SBS particles and a solvent are mixed and added into a four-necked flask, and additives and emulsifiers are added after heating and stirring for a period of time, and SBS latex is obtained after reduced pressure distillation; 2) Preparation of RS composite latex: SBS latex and SBR latex are mixed and stirred evenly, and then allowed to stand at a constant temperature for a period of time to obtain a stable RS composite latex.

2. The method for preparing RS composite latex according to claim 1, characterized in that: The solvent in step 1) includes one or a combination of two or more of deionized water, toluene, n-butane, n-pentane, and n-hexane.

3. The preparation method of RS composite latex according to claim 1, characterized in that, The additive in step 1) is a compound of polyethylene glycol, tributyl phosphate and polyacrylamide.

4. The method for preparing the RS composite latex according to claim 3, characterized in that: The mass ratio of the polyethylene glycol, tributyl phosphate and polyacrylamide is 4:1:1-7:1:

1.

5. The method for preparing RS composite latex according to claim 1, characterized in that: In the step 1), the pressure of the reduced pressure distillation is 1-4 Kpa and the temperature is 120-150°C.

6. The method for preparing the RS composite latex according to claim 1, characterized in that: The weight proportion of the emulsifier is 2 to 5 parts.

7. The method for preparing the RS composite latex according to claim 6, characterized in that: The emulsifier is prepared by compounding alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, and polymerized carboxylate polyacrylic acid.

8. The method for preparing the RS composite latex according to claim 6, characterized in that: The mass ratio of the alkylphenol polyoxyethylene ether, the fatty alcohol polyoxyethylene ether phosphate, and the polymerized carboxylate polyacrylic acid is 6:2:1-2:2:

1.

9. The method for preparing RS composite latex according to claim 1, characterized in that: In the step 2), the stirring speed is 200-400 r·min-1.

10. The method for preparing the RS composite latex according to claim 1, characterized in that In the step 2), the standing temperature is 20-50° C. and the standing time is 2-4 days.