WO2018148966A1

WO2018148966A1 - Sbr composite particle modified asphalt and preparation method thereof

Info

Publication number: WO2018148966A1
Application number: PCT/CN2017/074136
Authority: WO
Inventors: 徐思田; 周文婷; 陈加干; 周子炜; 王仕峰; 陶红; 马丕明; 董海云
Original assignee: 江苏宝利国际投资股份有限公司
Priority date: 2017-02-20
Filing date: 2017-02-20
Publication date: 2018-08-23

Abstract

The invention is directed to an SBR composite particle modified asphalt and a preparation method thereof. The SBR composite particle modified asphalt comprises the following components by weight percent: heavy traffic asphalt: 90-98, and modified composite particles: 2-10. The modified composite particles are obtained by Banbury mixing and granulating SBS, carbon black, SBR and calcium carbonate, wherein the ratio of the weight percentages of SBR/SBS is 70/10-50/30. The SBR composite particle modified asphalt prepared by the invention has the characteristics of high adhesive force, stable thermal storage and excellent high and low temperature performance. Particularly, it exhibits favorable ultraviolet aging in regions with low temperatures and high ultraviolet radiation, this quality being absent in SBS modified asphalt and matrix petroleum asphalt. Compared with traditional SBR modified asphalt production, the invention has the advantages of simple process route, low costs, and good stability of raw materials, and it is particularly suitable for promoting production in the Tibet region.

Description

SBR composite particle modified asphalt and preparation method thereof

Technical field

The invention relates to the field of improvement of asphalt materials, in particular to an SBR composite particle modified asphalt and a preparation method thereof.

Background technique

Tibet has its own unique geographical and climatic conditions. The air is thin, the air pressure is low, and the oxygen is small. From the perspective of temperature difference, the annual temperature difference between Tibet and the temperature difference is particularly obvious. The sunshine time is long, the ultraviolet rays are strong, and the dry season and the rainy season are distinct. More night rain, the climate type is complex, and the vertical change is large.

Asphalt is a by-product of crude oil after treatment. It is a derivative of complex hydrocarbons and non-metals that replace hydrogen in hydrocarbons. It also contains trace amounts of metal ions. Bituminous materials are susceptible to UV light, causing aging due to changes in composition and properties. Although the photochemical reaction of asphalt occurs on the surface layer under ultraviolet light irradiation, since the asphalt film thickness in the asphalt mixture is usually 5 to 15 μm, the ultraviolet radiation has a great influence on the asphalt mixture. Aging will make the surface layer of the asphalt become brittle and hard, and the strain of the fracture will be reduced, so that the temperature shrinkage crack is easily generated, resulting in cracking of the road surface.

In the natural environment of Tibet, the commonly used asphalt mixture ages quickly, and it is difficult to meet the requirements of high temperature stability, low temperature stability, durability and UV aging of asphalt pavement.

Pavement disease survey shows that UV radiation aging and rutting water damage are the main types of damage to asphalt roads on Qinghai-Tibet Highway. These diseases have a great relationship with the high temperature and temperature difference of the Qinghai-Tibet Highway and the heavy traffic environment. The harsh climatic environment of the Qinghai-Tibet Highway easily causes the asphalt to age seriously. The adhesion and flexibility of the asphalt deteriorates, which in turn exacerbates the phenomenon of low temperature cracks and water damage. The heavy traffic environment also requires the knot of the asphalt pavement. The structure is stronger.

Studies have shown that SBR polymer modified asphalt has a significant effect in improving the high temperature stability, low temperature stability and UV aging of asphalt pavement. Because SBR rubber blocks are difficult to cut and difficult to process, traditional SBR modified asphalt generally uses PSBR as a modifier. The traditional process has two drawbacks. First, PSBR is a fine-grained powdery solid. The preparation process requires the use of expensive diffusing agents, which seriously limits the cost of raw materials, and the PSBR has a low raw rubber content, usually only 80. Second, PSBR storage stability is poor, usually only 3 to 4 months of use, once expired and easy to agglomerate, increase the difficulty of use, more serious will lead to the production process Risk of cupping.

Patent CN 101434472A teaches increasing the UV resistance of SBR asphalt by adding CeO ₂ nanomaterials to the hot asphalt and UV-531 anti-purple external absorbent. The process is cumbersome, costly, prone to pollution, and the mixing conditions are limited, making it difficult to adapt to the needs of industrial production.

Patent CN102181162A discloses a magnesium-aluminum-based layered double hydroxide inorganic material which has a prominent effect on the anti-ultraviolet aging of asphalt. Patent CN104140580A and patent CN104356660A disclose that the magnesium-aluminum layered double hydroxide/SBR composite modifier can significantly improve SBR. And the anti-UV aging ability of asphalt, and realize the long-term stable dispersion of SBR and magnesium-aluminum-based layered double hydroxide in asphalt, and the prepared SBR modified asphalt has excellent ultraviolet aging resistance. However, layered double hydroxide nanocomposites must be used, and the main use of magnesium aluminum based layered double hydroxides is PVC material flame retardants, although studies have shown that adding them to asphalt can improve the UV aging resistance, but On the other hand, it will deteriorate the other physical properties of asphalt materials. The practical solution to the problem of high-altitude highway traffic that needs to be solved is only guiding significance and does not have the feasibility of applying production.

To this end, the invention is modified by self-developed SBR composite particles to obtain a novel SBR modified asphalt, which has simple production process and can further expand the applicability of the traditional SBR modified asphalt to high ultraviolet radiation regions, in production cost and The performance is better than the traditional SBR modified asphalt.

Summary of the invention

The object of the present invention is to overcome the defects of conventional modified asphalt such as SBS modified asphalt, road petroleum asphalt in the low temperature plateau region, and the stability of PSBR raw materials in the production of traditional SBR modified asphalt, so as to obtain anti-UV effect. Modified asphalt with excellent high and low temperature performance.

In order to obtain SBR modified asphalt materials satisfying the above properties, the present invention has been determined through various attempts to prepare SBR modified composite particles by SBR/SBS/carbon black/calcium carbonate first, and then put them into re-crossing. A technical solution for preparing the final SBR modified asphalt in the asphalt. Compared with the SBR prepared by the prior art, the SBR modified asphalt of the invention has excellent performance, wherein the carbon black has an outstanding reinforcing effect on the thermal aging and ultraviolet aging of the styrene-butadiene rubber, that is, the SBR, so that it can cope with the low temperature ultraviolet aging. The ability is particularly outstanding; SBS and SBR are not well compatible, and SBS and SBR are chosen to be combined first, and the two are physically mixed in advance by the high temperature and high torque extrusion of the internal mixer through the granulation process. This mixing process is completed in the granulation stage, that is, it does not need to occur in the asphalt preparation stage, which means that the preparation conditions of the high-performance modified asphalt are reduced, and the SBS and SBR are also reduced. The difference in density with asphalt reduces the tendency of polymer segregation. At the same time, SBS and SBR are mutually restrained, which further improves the bonding performance and thermal storage stability of the finished product, and expands the use range of SBR composite particle modified asphalt; The modification of the asphalt in the form of SBR modified composite particles can reduce the generation of harmful gases during the construction process and improve the construction environment. If the above process is realized in the high-speed shearing stage of the modified asphalt, it is necessary to increase the reaction temperature and prolong the reaction time, so that not only the harmful gas is more likely to be generated, but also the asphalt tends to age under high temperature for a long time, which affects the modification. Asphalt performance.

The object of the present invention can be achieved by the following technical solutions:

A high cementitious bitumen containing raw materials and weight percentages:

Heavy asphalt: 90~98;

Modified composite particles: 2 to 10; the ratio of addition of the above modified composite particles is Determined according to the amount of SBR added.

The modified composite particles are a mixture obtained by kneading and granulating SBS, carbon black, SBR, and calcium carbonate by an internal mixer, wherein the ratio of the weight percentage of SBR/SBS is 70/10 to 50/30. The scope of the SBR/SBS ratio of the present application is the optimal range obtained by the inventors from the comparison of multiple sets of experiments, taking into account the production cost and quality. Because of the low temperature and negative pressure environment in the Tibetan Plateau, the main disease damage of the road surface is ultraviolet radiation and rutting water damage. The advantage of SBR is that it is resistant to UV aging. The high content of SBR can significantly improve the UV aging resistance of the modified asphalt. SBS can form a spatial three-dimensional network structure with the asphalt matrix, thereby effectively improving the temperature performance, tensile properties, elasticity, cohesive adhesion properties and stability of the asphalt. Adding a certain amount of SBS can improve the resistance of the asphalt mixture. Rut performance.

More preferably, the modified composite particles are firstly mixed with SBS, carbon black, SBR, and calcium carbonate, and then added with water not more than 1% of the total mass of the mixture, and then mechanically granulated by an internal mixer. The composite particles are kneaded for 10 to 20 minutes, and the mixing temperature is 100 to 130 °C. Among them, the addition of calcium carbonate acts like a solvent, reducing the friction between the SBS and SBR molecules, while the addition of a small amount of water not more than 1% of the total mass of the mixture acts as a release agent to make it easier to extrude. The combination of the two solves the problem that the SBR becomes very viscous after heating, the shear stress is particularly large, and it cannot be extruded.

Preferably, the heavy asphalt is in accordance with the requirements of the Ministry of Communications JTG F40-2004.

SBS is a main modified raw material for providing structural reinforcement to asphalt. In the present invention, it is used for combating road surface diseases in a low-temperature negative pressure region which is prone to rutting water damage, and preferably SBS is star-type styrene-butadiene-styrene copolymerization. The mass ratio of styrene to butadiene is 3/7, and the molecular weight is 150,000 to 300,000. The reason why star SBS is chosen is because the inventor combined with the overall consideration, star SBS has high relative molecular weight, large cohesive strength, high physical crosslink density, high elastic modulus than linear SBS, and better reinforcement of asphalt structure. effect.

The SBR is preferably SBR 1502 wherein the bound styrene content (wt%) is from 22.5 to 24.5.

Preferably, in the modified composite particles, SBR and SBS account for 80% of the total mass, and carbon black and calcium carbonate account for 20% of the total mass.

The content of the calcium carbonate is preferably 0-5%, which is used for reducing the mutual friction between the SBR and the SBS and as a filler for granulation, and is convenient for granulation, and the content of the carbon black is preferably 15-20%, more Excellently, the calcium carbonate content is 5% and the carbon black content is 15%.

Preferably, the ratio of the weight percentage of the SBR/SBS is 70/10.

Another object of the present invention is to provide a preparation method suitable for the above SBR composite particle modified asphalt, which comprises the following steps:

(1) SBS, carbon black, SBR, and calcium carbonate are uniformly mixed according to the ratio, and water of not more than 1% of the total mass of the mixture is added, and then the modified composite particles are obtained by mechanical granulation, and the mixing granulation reaction time is 10 to 20 minutes;

Preferably, the mixing granulation reaction time is controlled to be 10 to 15 min.

(2) The modified composite particles are added to the heavy-duty asphalt of 170-190 °C in proportion, and sheared by a colloid mill at a high speed, and the temperature is maintained at a temperature corresponding to the swelling temperature of SBS at 170 to 190 ° C, and the composite particles are modified. The melt is thinned, and then stirred and developed on a high-speed disperser, the stirring speed is controlled to be 500-1000 r/min, and the stirring reaction is performed for 60-150 min to prepare the SBR composite particle-modified asphalt. Stirring development is mainly a process of cross-linking reaction, which is beneficial to increase the softening point of the product and reduce segregation. Controlling the stirring rate is to control the strength of the crosslinking reaction. If the stirring is too fast, the crosslinking reaction is incomplete, and the reaction time is too long, which will cause the attenuation of the polymer substance. The inventors have repeatedly tested and found that the stirring speed is 500-1000 r/min. The stirring reaction is preferably 60 to 150 minutes.

Under intense shear and high temperature, the SBS/SBR composite melts and becomes finely dispersed in the asphalt. The interactions that occur during this process increase the compatibility between the SBS/SBR composite and the asphalt, thereby improving the bonding properties of the modified asphalt.

Compared with the prior art, the SBR composite particle modified asphalt prepared by the invention is subjected to the separation test according to the GB/T0661-2011 standard, and the results show that the thermal storage stability is excellent. The viscosity of 135 °C is carried out according to the GB/T0625-2011 standard, and the results show that it has good construction workability. Penetration, ductility, softening point and viscosity of modified asphalt The tests were carried out according to GB/T0604-2011, GB/T0605-2011, GB/T0606-2011, JTJ052-2000 standards. The results show that the modified asphalt has excellent high and low temperature performance and high viscosity, especially after UV aging (60 °C, 7 days) The ductility is still above 20cm, and the low temperature performance is still excellent. In summary, the physical properties of the SBR composite particle modified asphalt meet the performance index of road asphalt specified in China, suitable for large-scale production and adoption, and achieved remarkable technical effects, especially in the following points, the effect is particularly prominent:

1. By mechanical granulation, the styrene-butadiene rubber rubber block can be used as a raw material without first grinding the styrene-butadiene rubber rubber block into a powder form to prepare the SBS/SBR composite, and the composite particles are directly used as a modifier. Adding to the matrix asphalt, preparing SBR modified asphalt, avoiding the use of PSBR, greatly reducing the raw material cost of SBR, simple process, easy to control, firstly causing the direct injection of particles also greatly reduces the traditional SBR modified asphalt The preparation conditions, while reducing the generation of harmful gases during the construction process, improve the construction environment.

2. 15 to 20 parts of carbon black are added in an appropriate amount during the granulation process. The carbon black component of the present invention functions on the one hand, and the carbon black itself has a shielding effect on light, which can effectively reduce the ultraviolet radiation and reduce the ultraviolet aging effect; on the other hand, the carbon black chemical activity is large, and the carbon black has high chemical activity. It has many surface active points and uses it to form a network structure with rubber during the mixing process, thereby greatly improving the Mooney viscosity of the rubber material, that is, the nano structure of the carbon black surface is used to reinforce the styrene-butadiene rubber, thereby effectively improving the final The viscoelastic properties of the product.

3. The combination of SBS and SBR reduces the density difference between SBS, SBR and asphalt, and reduces the tendency of polymer segregation. At the same time, SBS and SBR are mutually restrained, which further improves the bonding performance and thermal storage stability of the finished product. It has expanded the use range of SBR composite particle modified asphalt and reduced the production cost of asphalt pavement. It is especially suitable for promotion and production in Tibet. It has great economic benefits and is worth promoting.

detailed description

The invention will now be described in detail in connection with specific embodiments.

Example 1

Step 1: In terms of mass fraction, 3.2% of PSBR1502 (Shandong Gaoshi, average particle size is not more than 1.2mm), 0.4% of SBS T6302H, added to 90 parts of 70# heavy-duty asphalt, at 170-190 °C The shear was performed with a colloid mill.

Step 2: Transfer the sheared modified asphalt to a high-speed disperser for 150 min, stir the rotation speed of 800-900 r/min, and add a total of 0.05 parts of sulfur in the process to obtain a modified asphalt. The modified asphalt obtained was numbered 1, and the performance is shown in Table 1.

Example 2

Step 1: 10 parts of SBS, 15 parts of carbon black, 5 parts of calcium carbonate, and 70 parts of SBR 1502 were uniformly mixed in parts by mass. Add 1 part of water not more than the total mass of the mixture, the mixing time is 10 min, the mixing temperature is 100-130 ° C, and granulation is carried out to obtain composite modified composite particles.

Step 2: 3.9 parts of the composite modified composite particles and 1.8 parts of rubber oil were added to 95 parts of 70# pitch in parts by mass, and sheared with a colloid mill at 170 to 190 °C.

Step 3: The sheared modified asphalt is transferred to a high-speed disperser for 120 min stirring, and the stirring speed is 800-900 r/min. In the process, a total of 0.05 parts of sulfur is added in multiple times to obtain SBR composite particle modified asphalt. The modified asphalt obtained was numbered 2, and the performance is shown in Table 1.

Example 3

Step 1: 10 parts of SBS, 15 parts of carbon black, 5 parts of calcium carbonate, and 70 parts of SBR 1502 sub-package were uniformly mixed in parts by mass. Add 1 part of water not more than the total mass of the mixture, the mixing time is 10 min, the mixing temperature is 100-130 ° C, and granulation is carried out to obtain composite modified composite particles.

Step 2: 5 parts of the composite modified composite particles and 1.8 parts of rubber oil were added to 94 parts of 70# pitch in mass parts, and sheared with a colloid mill at 170 to 190 °C.

Step 3: Transfer the sheared modified asphalt to a high-speed disperser for 120 min, stir the rotation speed of 800-900 r/min, and add 0.09 in multiple times during the process. A portion of sulfur is used to prepare SBR composite particle modified asphalt. The modified asphalt obtained was numbered 3 and the performance is shown in Table 1.

Example 4

Step 1: 10 parts of SBS, 15 parts of carbon black, 5 parts of calcium carbonate, 35 parts of SBR 1502 genuine material, and 35 parts of SBR sub-plate material were uniformly mixed in parts by mass. Add 1 part of water not more than the total mass of the mixture, the mixing time is 10 min, the mixing temperature is 100-130 ° C, and granulation is carried out to obtain composite modified composite particles.

Step 2: 4.2 parts of the composite modified composite particles and 1.8 parts of rubber oil were added to 94 parts of 70# pitch in parts by mass, and sheared with a colloid mill at 170 to 190 °C.

Step 3: The sheared modified asphalt is transferred to a high-speed disperser for 120 min stirring, and the stirring speed is 800-900 r/min. In the process, a total of 0.05 parts of sulfur is added in multiple times to obtain SBR composite particle modified asphalt. The modified asphalt obtained was numbered 4 and the performance is shown in Table 1.

Table 1 Performance of modified asphalt obtained in Examples 1 to 4

Comparing Examples 1-4, it can be seen that the SBR composite particle modified asphalt represented by Example 4 has the highest viscosity toughness and exhibits excellent bonding performance, and its 5°C ductility is above 150 cm, and has good low temperature performance; The spread is minimal and has good Thermal storage stability; 135 ° C viscosity is also large, with good construction and operability, which means that the method of the present invention can also use SBR sub-brand material, that is, the corner scrap or impurities appearing in the SBR production process More waste, and better results, can greatly reduce the procurement cost of SBR.

Table 2 Experimental performance of modified asphalt obtained in Examples 1 to 4 at 60 ° C for 7 days of UV aging

Comparing the ultraviolet aging test performance of Examples 1-4, the SBR composite particle modified asphalt represented by Example 4 can maintain the 2°C ductility at 22.2 cm, indicating that it can still maintain good after the influence of high ultraviolet radiation. Low temperature performance. The above conclusions also verify that the SBR composite particle modified asphalt according to the present invention is suitable for popularization and application in low temperature and high ultraviolet radiation regions all year round.

In order to further verify the advantages of this type of SBR composite particle modified asphalt in terms of road performance, the inventors conducted a more complete demonstration through the mixture test. The test conditions of the mixture were as follows: grading AC-13, oil-stone ratio 4.9%.

Table 3 Road performance of modified asphalt mixture obtained in Examples 1-4

In the case where the gradation type and the gradation composition are the same, the results of the mixture test of Comparative Examples 1-4 can be found that the SBR modified asphalt represented by Example 4 (the modified composite particle ratio is SBS/carbon black) /Calcium carbonate/SBR1502 sub-brand material/SBR1502 plus brand material=10:15:5:35:35) SBR composite granulated modified asphalt Comparative Example 1 Shandong Gaoshi SBR (original rubber content 75%) modified asphalt, The water stability increased by 8.27%; the freeze-thaw splitting strength increased by 6.34%; the dynamic stability increased by 73.46%; and the low temperature crack resistance improved by 46.91%.

In summary, the SBR composite particle modified asphalt involved in the present invention is suitable for popularization and application in low temperature and high ultraviolet radiation regions all year round.

Claims

An SBR composite particle modified asphalt characterized in that SBS, carbon black, SBR and calcium carbonate are made into modified composite particles by an internal mixer to modify asphalt, and the modified asphalt comprises the following components and weight percentage content:

Heavy cross-linking: 90 ~ 98; modified composite particles: 2 ~ 10;

The modified composite particles are a mixture obtained by kneading and granulating SBS, carbon black, SBR, and calcium carbonate by an internal mixer, wherein the ratio of the weight percentage of SBR/SBS is 70/10 to 50/30.
The SBR composite particle modified asphalt according to claim 1, wherein the heavy asphalt is in accordance with the requirements of the Ministry of Communications JTG F40-2004.
The SBR composite particle modified asphalt according to claim 1, wherein the SBS, carbon black, SBR, and calcium carbonate are mixed in an internal mixer, and water having a mass of not more than 1% of the total mass of the mixture is added. .
The SBR composite particle modified asphalt according to claim 3, wherein the mixed kneaded material is mechanically extruded and granulated, and the mixing time is 10 to 20 minutes, and the mixing temperature is 100 to 130 °C.
The SBR composite particle-modified pitch according to claim 1, wherein the SBS is a star-type styrene-butadiene-styrene copolymer, wherein a mass ratio of styrene to butadiene is 3/. 7, the number average molecular weight is 150,000 to 300,000.
The SBR composite particle-modified pitch according to claim 1, wherein the SBR is SBR 1502, and the bound styrene content (wt%) is 22.5 to 24.5.
The SBR composite particle-modified pitch according to claim 1, wherein the ratio of the weight percentage of the SBR/SBS is 70/10.
The method for preparing SBR composite particle modified asphalt according to any one of claims 1 to 7, characterized in that the method comprises the following steps:

(1) Mixing SBS, carbon black, SBR, and calcium carbonate in proportion, adding water of not more than 1% of the total mass of the mixture, and then mechanically granulating to obtain modified composite particles. The mixing time is 10 to 20 minutes;

(2) The modified composite particles are added to the heavy-duty asphalt of 170-190 °C in proportion, and sheared by a colloid mill at a high speed, the temperature is maintained at 170-190 ° C, and the modified composite particles are melted and thinned, and then at a high speed. Stirring development on the dispersing machine, controlling the stirring speed of 500-1000r/min, stirring reaction for 60-150min, then preparing SBR composite particle modified asphalt.
The method for preparing SBR composite particle modified asphalt according to claim 8, wherein in the step (2), during the stirring development process, the total mass of the total SBR composite particle modified asphalt is added in multiple times. % stabilizer.