Rubber asphalt master batch and method for preparing stable rubber asphalt from rubber asphalt master batch

Abstract

The invention particularly relates to a rubber asphalt master batch and a method for preparing stable rubber asphalt from the rubber asphalt master batch. The rubber asphalt master batch comprises the following raw materials in parts by mass: 15%-25% of anti-rutting master batch, 10%-15% of furfural extract oil, 45%-60% of waste tire rubber powder, 5%-8% of liquid coumarone resin, 1%-2% of dibenzothiazyl disulfide, 1%-2% of octadecanethiol, 2%-4% of a rubber cracking agent, 0.5%-1% of an odor removing agent and 3%-9% of powdered styrene butadiene rubber. And 0.5%-1.5% of sulfur, wherein the total mass of the sulfur is 100%. The method for preparing the stable rubber asphalt by using the rubber asphalt master batch comprises the following steps: firstly, weighing the matrix asphalt for producing the stable rubber asphalt according to the proportion, and heating to 150-170 DEG C; secondly, weighing the rubber asphalt master batch according to the proportion, and putting the rubber asphalt master batch into a product obtained in the first step; and finally, heating the product obtained in the step 2 to 185-195 DEG C, and continuously stirring for 45-60 minutes to obtain the stable rubber asphalt. The product produced by the invention is simple in process, stable in performance, low-carbon, environment-friendly, good in construction workability and outstanding in comprehensive performance.

Description

[0001] manual Technical Field

[0002] The present invention belongs to the technical field of road engineering, and specifically relates to a rubber asphalt masterbatch and a method for preparing a stable rubber asphalt using the rubber asphalt masterbatch. The stable rubber asphalt prepared using the rubber asphalt masterbatch has the characteristics of simple process, stable performance, low carbon and environmental protection, high solubility, good construction and workability, outstanding comprehensive performance and easy transportation and storage. Background Art

[0003] With the development of the economy, the rapid increase in traffic volume and the increasing severity of vehicle overloading, the total mileage of asphalt pavement maintenance and renovation is increasing. Due to deficiencies in design, materials, construction technology, construction management and quality control, as well as damage caused by natural disasters, asphalt pavements have a large number of cracks, rutting, bulging, looseness, surface oiling and potholes after being put into use for 3-5 years, which seriously affects driving speed, comfort and safety. Domestic highways have entered a large-scale maintenance period, and the engineering tasks of major road renovations are becoming increasingly huge. How to achieve sustainable and efficient development, and research and application of new processes and new materials for road maintenance, renovation, maintenance and other issues are imperative, and economically feasible, environmentally friendly and convenient maintenance processes and new materials are urgently needed to solve them.

[0004] With the development of the automobile industry, the amount of waste tires generated is increasing. According to statistics from the World Health Organization, the total stock of waste tires in the world has reached 3 billion, and is growing at a rate of about 1 billion per year. Waste tires are difficult to degrade under natural conditions. Long-term open-air stacking not only occupies a large amount of land, but also easily breeds mosquitoes to spread diseases and cause fires. The "black pollution" caused by waste tires has become a very serious problem. On the other hand, waste tires, as a renewable resource, are also called "black gold mines."

[0005] Preparing waste tires into rubber powder and then using the rubber powder in the production of road binder - rubber asphalt is an effective recycling method. The natural rubber, synthetic rubber and various additives in waste tires, such as sulfur, carbon black, silicon oxide and other chemical components, have a certain effect on improving the performance of rubber asphalt and rubber asphalt concrete. Crushing waste tires into rubber powder and swelling it with asphalt under high temperature conditions to make rubber asphalt for application in road engineering can not only improve some of the properties of asphalt, but also provide a green and environmentally friendly way for the treatment of waste tires. Compared with petroleum asphalt, many properties of rubber asphalt have been improved to varying degrees: rubber asphalt is more viscous under high temperature conditions, the high temperature stability of asphalt mixture is better, and the elastic recovery ability is strong, which significantly improves its high temperature rutting resistance in actual engineering applications; the low temperature performance is significantly improved compared with the base asphalt; the antioxidant in the tire rubber can enhance the anti-aging ability of asphalt; the large amount of rubber powder and the porous structure of rubber particles make the road surface achieve the effect of noise reduction; the construction cost is low, the road surface service life is long, and the road maintenance cost is reduced in the later stage.

[0006] The main components of waste tire rubber powder are natural rubber and synthetic rubber accounting for about 70%, carbon black accounting for 15%-25%, oil softener accounting for about 10%, and vulcanizer accounting for 1%-3%. At present, the traditional production process of rubber asphalt is to stir, high-speed shear and swell the waste tire rubber powder particles with a certain grade and the matrix asphalt at high temperature (180℃-220℃), and obtain rubber asphalt after the mixture is swollen and stable. The rubber asphalt is the product of the rubber powder particles after development and swelling suspended in the matrix asphalt. It can be seen that in the process of high-temperature stirring, high-speed shearing and swelling development of traditional rubber asphalt, the aromatic phenol and saturated phenol in the matrix asphalt are absorbed by the rubber powder particles, resulting in volume expansion, and the relative content of the light components of aromatic phenol and saturated phenol in the matrix asphalt is reduced, while the viscosity, toughness and elasticity are enhanced, so that the performance of the matrix asphalt is greatly improved, and then the comprehensive road performance of the mixture prepared with rubber asphalt is improved. However, in this process, only the part of the waste tire rubber powder that contacts the base asphalt undergoes cracking reaction. The natural rubber and synthetic rubber in the rubber powder are dissolved into the base asphalt, acting as a modifier for the base asphalt and improving the performance of the base asphalt. However, more than 95% of the waste rubber powder is still suspended in the base asphalt in the form of particles, without acting as a modifier, but only as a filler.

[0007] Due to the material composition of waste tire rubber powder and the limitations of traditional rubber asphalt production process, there are many disadvantages in the production, transportation, storage, mixture production and construction of rubber asphalt. The advantages of rubber asphalt have not been fully released, which has greatly affected the promotion and application, mainly in the following aspects:

[0008] (1) Finished rubber asphalt is prone to segregation and stratification. Since the density of waste tire rubber powder is 1.5 times that of base asphalt, the rubber powder suspended in the base asphalt in a particle state is unstable, and the precipitation of the rubber powder is inevitable over time;

[0009] (2) The indicators of finished rubber asphalt decay quickly. Under high temperature conditions, the surface of rubber powder particles in contact with the base asphalt continuously absorbs aromatic phenols and saturated phenols in the asphalt, and is dissolved by the light components of the asphalt to become a component of the asphalt. In this process, the softening point of the rubber asphalt decreases, the viscosity decreases, the ductility decreases, and the penetration increases. This process is consistent with the production, transportation, storage, mixture production, construction and the entire life cycle of the rubber asphalt after the road is opened to traffic;

[0010] (3) The finished rubber asphalt has a strong odor during the application process. Due to the presence of vulcanizing agents in waste rubber powder, during high-temperature stirring, high-speed shearing, swelling development and use, the flue gas of rubber asphalt contains H2S and sulfur-containing organic matter. These substances often have a foul odor, especially H2S gas. The human olfactory limit for H2S is extremely low, and H2S gas is extremely toxic to organisms, which has greatly affected the industry's intention to use it;

[0011] (4) The temperature of finished rubber asphalt pumping, mixing and construction rolling is extremely high. Since waste tire rubber powder continuously absorbs aromatic phenol and saturated phenol in the base asphalt, the viscosity of the asphalt increases sharply. In order to make the rubber asphalt have sufficient construction and compaction properties, the temperature needs to be greatly increased to reduce the viscosity;

[0012] (5) The oil-to-stone ratio of the finished rubber asphalt mixture is too high. As the rubber powder continuously absorbs the light components in the base asphalt, the free asphalt content in the rubber asphalt that plays a lubricating role is sharply reduced. In order for the mixture to reach the volume index required for construction, it is necessary to increase the amount of rubber asphalt in the mixture, which increases the production cost of the mixture by at least 30%;

[0013] (6) The performance of waste tire rubber powder is not fully released. Waste tire rubber powder accounts for 20% of rubber asphalt. Due to the limitations of current material formula and production process, only less than 5% of the large amount of natural rubber and synthetic rubber in waste tire rubber powder is released into asphalt to act as a modifier. More than 95% of the high-quality modifier is not released and is only suspended in the asphalt in the form of granular fillers, resulting in the waste of high-quality modifiers;

[0014] (7) The production and application of finished rubber asphalt is extremely inconvenient, and the cost has not been further optimized. Finished rubber asphalt needs to undergo long-term high temperature, high-speed shear and swelling development, and is prone to segregation and stratification, has a strong odor, is greatly affected by environmental protection, and has rapid index decay, resulting in low production efficiency of finished rubber asphalt, tight transportation and storage time, the need for special tanks and special storage, and difficulty in pumping. The production efficiency of the mixture is low, and many links make the application of rubber asphalt extremely inconvenient.

[0015] Therefore, it is necessary to develop a rubber asphalt masterbatch and a method for preparing stable rubber asphalt to solve the many drawbacks of traditional rubber asphalt in the production, transportation, storage, mixture production, construction and cost control processes, and provide a new idea for the promotion and application of rubber asphalt in my country. Summary of the invention

[0016] In order to solve the many bottlenecks existing in the application process of traditional rubber asphalt, the present invention provides a rubber asphalt masterbatch and a method for preparing stable rubber asphalt using the rubber asphalt masterbatch. The prepared stable rubber asphalt product is stable and does not segregate, the indicators do not decay, the oil-stone ratio of the mixture does not increase, the asphalt pumping and construction temperature is low, and there is no irritating odor. At the same time, the natural rubber and synthetic rubber in the waste tire rubber powder can be completely and fully released into the matrix asphalt, and the comprehensive road performance of the stable rubber asphalt is greatly improved. The production process of preparing stable rubber asphalt using the rubber asphalt masterbatch is simple, the production cost is low, and it can be produced on-site as needed.

[0017] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0018] A rubber asphalt masterbatch comprises the following components by weight: 15%-25% of anti-rutting masterbatch, 10%-15% of furfural extracted oil, 45%-60% of waste tire rubber powder, 5%-8% of liquid coumarone resin, 1%-2% of dibenzothiazole disulfide, 1%-2% of octadecanethiol, 2%-4% of rubber cracking agent, 0.5%-1% of deodorant, 3%-9% of powdered styrene-butadiene rubber, and 0.5%-1.5% of sulfur, and the total weight thereof meets 100%.

[0019] Preferably, the anti-rutting masterbatch has a softening point of 85-100°C, a needle penetration (0.1 mm) of less than or equal to 20, and an ash content of less than or equal to 1%;

[0020] Preferably, the kinematic viscosity (100°C) of the furfural extracted oil is 20-30 cSt, and the aromatic phenol content is 80%-100%;

[0021] Preferably, the maximum particle size of the waste tire rubber powder is less than 0.6 mm, and other performance indicators meet the requirements of "Road Waste Tire Rubber Powder" (JT / T798-2011);

[0022] Preferably, the softening point of the liquid coumarone resin is 5°C-25°C;

[0023] Preferably, the dibenzothiazyl disulfide has a melting point greater than 164°C, an ash content less than or equal to 0.5%, and a maximum particle size less than or equal to 0.005 mm;

[0024] Preferably, the octadecanethiol has a purity greater than or equal to 98%, a melting point of 30°C-33°C, and a maximum particle size less than or equal to 0.075 mm;

[0025] Preferably, the rubber cracking agent is a liquid with a purity greater than or equal to 99% and a relative density (20 / 4°C) of 0.7-0.9;

[0026] Preferably, the maximum particle size of the deodorant is less than or equal to 15 μm, the solid content is greater than or equal to 99%, and the water-soluble content is less than or equal to 0.5%;

[0027] Preferably, the maximum particle size of the powdered styrene-butadiene rubber is less than or equal to 0.3 mm, and the average molecular weight is 200,000-300,000;

[0028] Preferably, the sulfur is in powder form, with a maximum particle size of less than or equal to 0.15 mm, and other performance indicators meet the requirements of superior products in "Industrial Sulfur" (GB / T2449-2006).

[0029] The present invention also provides a method for preparing rubber asphalt masterbatch, which comprises the following steps:

[0030] Step 1, weighing in proportion, adding anti-rutting masterbatch, furfural extracted oil, waste tire rubber powder, liquid coumarone resin, dibenzothiazole disulfide, octadecyl mercaptan, rubber cracking agent and deodorant into a pressure reactor, and stirring for 5-10 minutes;

[0031] Step 2, heating the product obtained in step 1 to 200°C-230°C and maintaining a pressure of 1Mpa;

[0032] Step 3, the product obtained in step 2 is sheared continuously for 240 min-360 min using a fast shearing machine under the condition of constant temperature and pressure, and the speed of the shearing machine is greater than or equal to 2900 rpm;

[0033] Step 4, restoring the product obtained in step 3 to standard atmospheric pressure and reducing the temperature to 190° C.-195° C.;

[0034] Step 5, adding the powdered styrene-butadiene rubber into the product obtained in step 4, maintaining 190° C.-195° C., and continuously rapid shearing for 30 min-60 min, with the speed of the shearing machine being greater than or equal to 2900 rpm;

[0035] Step 6, putting the product obtained in step 5 into a steel belt granulator for granulation;

[0036] Step 7, cooling the product obtained in step 6 to below 30° C.;

[0037] Step eight, fully mixing the product obtained in step seven with sulfur to obtain rubber asphalt masterbatch.

[0038] Preferably, the maximum particle size of the product obtained in step 6 is less than or equal to 2 mm;

[0039] Preferably, the trichloroethylene solubility of the rubber asphalt masterbatch prepared according to the above steps 1 to 8 is greater than or equal to 99%.

[0040] The present invention also provides a method for preparing stable rubber asphalt using rubber asphalt masterbatch, the method comprising the following steps:

[0041] Step 1: weigh the base asphalt used to produce the stabilized rubber asphalt according to the proportion, and heat it to 150° C.-170° C.;

[0042] Step 2, weighing the rubber asphalt masterbatch according to the proportion, and adding the rubber asphalt masterbatch into the product obtained in step 1;

[0043] Step 3: Heat the product obtained in step 2 to 185°C-195°C and continue stirring for 45min-60min to obtain a stable rubber asphalt.

[0044] Preferably, the rubber asphalt masterbatch prepared according to the above steps, according to the usage amount accounting for 30%-50% of the total weight of the stabilized rubber asphalt, has a softening point of greater than or equal to 55°C, a needle penetration (0.1mm) of 20-60, an elongation of greater than or equal to 15cm at 5°C, a trichloroethylene solubility greater than or equal to 99%, a dynamic viscosity at 60°C greater than or equal to 6000Pa.s, a 48h softening point difference less than or equal to 2°C, an elastic recovery greater than or equal to 75%, and a viscosity at 180°C less than or equal to 3Pa.s.

[0045] The rubber asphalt masterbatch and the method for preparing the stable rubber asphalt developed by the present invention have the following advantages:

[0046] 1. Under high temperature and high pressure, with the help of furfural extraction oil softener, dibenzothiazole disulfide, octadecyl mercaptan and other desulfurizers, as well as rubber cracking agent, the natural rubber and synthetic rubber in the waste tire rubber powder are quickly depolymerized and fully released in the form of macromolecular polymers, acting as a modifier of the matrix asphalt, rather than acting as a filler in the matrix asphalt in the form of rubber powder particles suspended;

[0047] 2. Waste tire rubber powder is completely released into the matrix asphalt in the form of macromolecular polymers and becomes a component of asphalt. Unlike traditional rubber asphalt, it will not continuously absorb light components in the matrix asphalt, thereby reducing the lubricating components of the asphalt;

[0048] 3. A large amount of hydrogen sulfide, sulfur dioxide and asphalt fume generated during the depolymerization of waste tire rubber powder are absorbed, converted and decomposed by the effective ingredients of the deodorizer, making the prepared stable rubber asphalt more environmentally friendly;

[0049] 4. Liquid coumarone resin has good compatibility with powdered styrene-butadiene rubber, anti-rutting masterbatch, furfural extracted oil, natural rubber, synthetic rubber, and base asphalt. It mainly acts as a tackifier, plasticizer, and regenerator in rubber asphalt.

[0050] 5. Sulfur, as a natural stabilizer, can cause the rubber asphalt masterbatch and the matrix asphalt to quickly produce secondary cross-linking reaction and vulcanization, so that the comprehensive mechanical properties of the prepared stabilized rubber asphalt, such as crack resistance, tensile strength, shear resistance, compression resistance and impact strength, are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of a process flow for preparing a rubber asphalt masterbatch according to the present invention;

[0052] Figure 2 A schematic diagram of a process flow of preparing stable rubber asphalt from a rubber asphalt masterbatch of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] Example 1

[0055] A rubber asphalt masterbatch comprises the following components by weight: 25% of anti-rutting masterbatch, 15% of furfural extracted oil, 40% of waste tire rubber powder, 5% of liquid coumarone resin, 1% of dibenzothiazole disulfide, 1% of octadecyl mercaptan, 2.5% of rubber cracking agent, 0.5% of deodorant, 9% of powdered styrene-butadiene rubber, and 1% of sulfur, and the total weight thereof meets 100%.

[0056] Preferably, the anti-rutting masterbatch has a softening point of 100°C, a needle penetration (0.1 mm) of 5, and an ash content of 1%;

[0057] Preferably, the kinematic viscosity (100°C) of the furfural extracted oil is 20 cSt, and the aromatic phenol content is 80%;

[0058] Preferably, the maximum particle size of the waste tire rubber powder is 0.6 mm, and other performance indicators meet the requirements of "Road Waste Tire Rubber Powder" (JT / T798-2011);

[0059] Preferably, the softening point of the liquid coumarone resin is 5°C;

[0060] Preferably, the dibenzothiazyl disulfide has a melting point of 164.4°C, an ash content of 0.5%, and a maximum particle size of 0.005 mm;

[0061] Preferably, the octadecyl mercaptan has a purity of 98%, a melting point of 30°C, and a maximum particle size of 0.075 mm;

[0062] Preferably, the rubber cracking agent is a liquid with a purity of 99% and a relative density (20 / 4°C) of 0.7;

[0063] Preferably, the maximum particle size of the deodorant is 15 μm, the solid content is 99%, and the water-soluble content is 0.5%;

[0064] Preferably, the maximum particle size of the powdered styrene-butadiene rubber is 0.3 mm and the average molecular weight is 300,000;

[0065] Preferably, the sulfur is in powder form with a maximum particle size of 0.15 mm, and other performance indicators meet the requirements of superior products in "Industrial Sulfur" (GB / T2449-2006).

[0066] The present invention also provides a method for preparing rubber asphalt masterbatch, which comprises the following steps:

[0067] Step 1, weighing in proportion, adding anti-rutting masterbatch, furfural extracted oil, waste tire rubber powder, liquid coumarone resin, dibenzothiazole disulfide, octadecyl mercaptan, rubber cracking agent and deodorant into a pressure reactor, and stirring for 10 minutes;

[0068] Step 2, heating the product obtained in step 1 to 200° C. and maintaining a pressure of 1 MPa;

[0069] Step 3, the product obtained in step 2 is sheared for 240 minutes using a fast shearing machine under the condition of constant temperature and pressure, and the speed of the shearing machine is 2900 rpm;

[0070] Step 4, restoring the product obtained in step 3 to standard atmospheric pressure and reducing the temperature to 190° C.;

[0071] Step 5, adding the powdered styrene-butadiene rubber into the product obtained in step 4, maintaining 190° C., and continuously rapid shearing for 30 minutes, with the speed of the shearing machine being 2900 rpm;

[0072] Step 6, putting the product obtained in step 5 into a steel belt granulator for granulation;

[0073] Step 7, cooling the product obtained in step 6 to 25° C.;

[0074] Step eight, fully mixing the product obtained in step seven with sulfur to obtain rubber asphalt masterbatch.

[0075] Preferably, the maximum particle size of the product obtained in step 6 is 2 mm;

[0076] Preferably, the trichloroethylene solubility of the rubber asphalt masterbatch prepared according to the above steps 1 to 8 is 99%.

[0077] The present invention also provides a method for preparing stable rubber asphalt using rubber asphalt masterbatch, the method comprising the following steps:

[0078] Step 1: weigh the base asphalt used to produce the stabilized rubber asphalt according to the proportion and heat it to 150° C.

[0079] Step 2, weighing the rubber asphalt masterbatch according to the proportion, and adding the rubber asphalt masterbatch into the product obtained in step 1;

[0080] Step 3: Heat the product obtained in step 2 to 185° C. and continue stirring for 45 minutes to obtain a stable rubber asphalt.

[0081] Preferably, the rubber asphalt masterbatch prepared according to the above steps, according to the usage amount accounting for 30% of the total weight of the stabilized rubber asphalt, has a softening point of 55°C, a needle penetration (0.1mm) of 60, an elongation of 15cm at 5°C, a trichloroethylene solubility of 99.5%, a dynamic viscosity at 60°C of 6000Pa.s, a 48h softening point difference of 2°C, an elastic recovery of 75%, and a viscosity of 1.3Pa.s at 180°C.

[0082] Example 2

[0083] A rubber asphalt masterbatch comprises the following components by weight: 20% of anti-rutting masterbatch, 10% of furfural extracted oil, 47.5% of waste tire rubber powder, 5% of liquid coumarone resin, 1% of dibenzothiazole disulfide, 1% of octadecyl mercaptan, 4% of rubber cracking agent, 1% of deodorant, 9% of powdered styrene-butadiene rubber, and 1.5% of sulfur, and the total weight thereof meets 100%.

[0084] Preferably, the anti-rutting masterbatch has a softening point of 85°C, a needle penetration (0.1 mm) of 20, and an ash content of 0.2%;

[0085] Preferably, the kinematic viscosity (100°C) of the furfural extracted oil is 30 cSt, and the aromatic phenol content is 100%;

[0086] Preferably, the maximum particle size of the waste tire rubber powder is 0.15 mm, and other performance indicators meet the requirements of "Road Waste Tire Rubber Powder" (JT / T798-2011);

[0087] Preferably, the softening point of the liquid coumarone resin is 25°C;

[0088] Preferably, the dibenzothiazyl disulfide has a melting point of 166°C, an ash content of 0.2%, and a maximum particle size of 0.002 mm;

[0089] Preferably, the octadecyl mercaptan has a purity of 99.4%, a melting point of 33°C, and a maximum particle size of 0.005 mm;

[0090] Preferably, the rubber cracking agent is a liquid with a purity of 99.9% and a relative density (20 / 4°C) of 0.9;

[0091] Preferably, the maximum particle size of the deodorant is 10 μm, the solid content is 99.5%, and the water-soluble content is 0.11%;

[0092] Preferably, the powdered styrene-butadiene rubber has a maximum particle size of 0.09 mm and an average molecular weight of 200,000;

[0093] Preferably, the sulfur is in powder form with a maximum particle size of 0.075 mm, and other performance indicators meet the requirements of superior products in "Industrial Sulfur" (GB / T2449-2006).

[0094] The present invention also provides a method for preparing rubber asphalt masterbatch, which comprises the following steps:

[0095] Step 1, weighing in proportion, adding anti-rutting masterbatch, furfural extracted oil, waste tire rubber powder, liquid coumarone resin, dibenzothiazole disulfide, octadecyl mercaptan, rubber cracking agent and deodorant into a pressure reactor, and stirring for 10 minutes;

[0096] Step 2, heating the product obtained in step 1 to 230°C and maintaining the pressure at 1 MPa;

[0097] Step 3, the product obtained in step 2 is sheared for 360 minutes using a fast shearing machine under the condition of constant temperature and pressure, and the speed of the shearing machine is 3300 rpm;

[0098] Step 4, restoring the product obtained in step 3 to standard atmospheric pressure and reducing the temperature to 195° C.;

[0099] Step 5, adding the powdered styrene-butadiene rubber into the product obtained in step 4, maintaining 195° C., and continuously rapid shearing for 60 minutes, with the speed of the shearing machine being 3300 rpm;

[0100] Step 6, putting the product obtained in step 5 into a steel belt granulator for granulation;

[0101] Step 7, cooling the product obtained in step 6 to 20° C.;

[0102] Step eight, fully mixing the product obtained in step seven with sulfur to obtain rubber asphalt masterbatch.

[0103] Preferably, the maximum particle size of the product obtained in step 6 is less than or equal to 2 mm;

[0104] Preferably, the trichloroethylene solubility of the rubber asphalt masterbatch prepared according to the above steps 1 to 8 is 99.3%.

[0105] The present invention also provides a method for preparing stable rubber asphalt using rubber asphalt masterbatch, the method comprising the following steps:

[0106] Step 1: weigh the base asphalt used to produce the stabilized rubber asphalt according to the proportion and heat it to 170° C.

[0107] Step 2, weighing the rubber asphalt masterbatch according to the proportion, and adding the rubber asphalt masterbatch into the product obtained in step 1;

[0108] Step 3: Heat the product obtained in step 2 to 195° C. and continue stirring for 60 minutes to obtain a stable rubber asphalt.

[0109] Preferably, the rubber asphalt masterbatch prepared according to the above steps, according to the usage amount accounting for 50% of the total weight of the stabilized rubber asphalt, has a softening point of 74°C, a needle penetration (0.1mm) of 20, an elongation of 25cm at 5°C, a trichloroethylene solubility of 99%, a dynamic viscosity at 60°C of 20000Pa.s, a 48h softening point difference of 1.2°C, an elastic recovery of 85%, and a viscosity of 2.3Pa.s at 180°C.

[0110] Example 3

[0111] A rubber asphalt masterbatch comprises the following components by weight: 15% of anti-rutting masterbatch, 10% of furfural extracted oil, 60% of waste tire rubber powder, 5% of liquid coumarone resin, 2% of dibenzothiazole disulfide, 2% of octadecanethiol, 2.5% of rubber cracking agent, 0.6% of deodorant, 3.5% of powdered styrene-butadiene rubber, and 0.5% of sulfur, and the total weight thereof meets 100%.

[0112] Preferably, the anti-rutting masterbatch has a softening point of 90°C, a needle penetration (0.1 mm) of 2, and an ash content of 0.5%;

[0113] Preferably, the kinematic viscosity (100°C) of the furfural extracted oil is 25 cSt, and the aromatic phenol content is 90%;

[0114] Preferably, the maximum particle size of the waste tire rubber powder is 0.4 mm, and other performance indicators meet the requirements of "Road Waste Tire Rubber Powder" (JT / T798-2011);

[0115] Preferably, the softening point of the liquid coumarone resin is 20°C;

[0116] Preferably, the dibenzothiazyl disulfide has a melting point of 169°C, an ash content of 0.32%, and a maximum particle size of 0.001 mm;

[0117] Preferably, the octadecyl mercaptan has a purity of 98.4%, a melting point of 31°C, and a maximum particle size of 0.019 mm;

[0118] Preferably, the rubber cracking agent is a liquid with a purity of 99% and a relative density (20 / 4°C) of 0.8;

[0119] Preferably, the maximum particle size of the deodorant is 10 μm, the solid content is 99.3%, and the water-soluble content is 0.34%;

[0120] Preferably, the powdered styrene-butadiene rubber has a maximum particle size of 0.2 mm and an average molecular weight of 250,000;

[0121] Preferably, the sulfur is in powder form with a maximum particle size of 0.1 mm, and other performance indicators meet the requirements of superior products in "Industrial Sulfur" (GB / T2449-2006).

[0122] The present invention also provides a method for preparing rubber asphalt masterbatch, which comprises the following steps:

[0123] Step 1, weighing in proportion, adding anti-rutting masterbatch, furfural extracted oil, waste tire rubber powder, liquid coumarone resin, dibenzothiazole disulfide, octadecyl mercaptan, rubber cracking agent and deodorant into a pressure reactor, and stirring for 8 minutes;

[0124] Step 2, heating the product obtained in step 1 to 210° C. and maintaining a pressure of 1 MPa;

[0125] Step 3, the product obtained in step 2 is sheared for 280 minutes using a fast shearing machine at a speed of 3000 rpm under the condition of constant temperature and pressure;

[0126] Step 4, restoring the product obtained in step 3 to standard atmospheric pressure and reducing the temperature to 192° C.;

[0127] Step 5, adding the powdered styrene-butadiene rubber into the product obtained in step 4, maintaining 192° C., and continuously rapid shearing for 45 minutes, with the speed of the shearing machine being 3000 rpm;

[0128] Step 6, putting the product obtained in step 5 into a steel belt granulator for granulation;

[0129] Step 7, cooling the product obtained in step 6 to 25° C.;

[0130] Step eight, fully mixing the product obtained in step seven with sulfur to obtain rubber asphalt masterbatch.

[0131] Preferably, the maximum particle size of the product obtained in step 6 is 1.8 mm;

[0132] Preferably, the trichloroethylene solubility of the rubber asphalt masterbatch prepared according to the above steps 1 to 8 is 99.2%.

[0133] The present invention also provides a method for preparing stable rubber asphalt using rubber asphalt masterbatch, the method comprising the following steps:

[0134] Step 1: weigh the base asphalt used to produce the stabilized rubber asphalt according to the proportion and heat it to 160° C.

[0135] Step 2, weighing the rubber asphalt masterbatch according to the proportion, and adding the rubber asphalt masterbatch into the product obtained in step 1;

[0136] Step 3: Heat the product obtained in step 2 to 193° C. and continue stirring for 60 minutes to obtain a stable rubber asphalt.

[0137] Preferably, the rubber asphalt masterbatch prepared according to the above steps, according to the usage amount accounting for 45% of the total weight of the stabilized rubber asphalt, has a softening point of 80°C, a needle penetration (0.1mm) of 30, an elongation of 18.5cm at 5°C, a trichloroethylene solubility of 99.1%, a dynamic viscosity of 58000Pa.s at 60°C, a softening point difference of 1.4°C after 48h, an elastic recovery of 90%, and a viscosity of 2.9Pa.s at 180°C.

[0138] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A rubber asphalt masterbatch, characterized in that: The invention comprises the following raw materials in parts by mass: 15%-25% of anti-rutting masterbatch, 10%-15% of furfural extracted oil, 45%-60% of waste tire rubber powder, 5%-8% of liquid coumarone resin, 1%-2% of dibenzothiazole disulfide, 1%-2% of octadecyl mercaptan, 2%-4% of rubber cracking agent, 0.5%-1% of deodorizing agent, 3%-9% of powdered styrene-butadiene rubber and 0.5%-1.5% of sulfur, and the total mass meets 100%. Preferably, the anti-rutting masterbatch has a softening point of 85-100°C, a needle penetration (0.1 mm) of less than or equal to 20, and an ash content of less than or equal to 1%; Preferably, the kinematic viscosity (100°C) of the furfural extracted oil is 20-30 cSt, and the aromatic phenol content is 80%-100%; Preferably, the maximum particle size of the waste tire rubber powder is less than 0.6 mm, and other performance indicators meet the requirements of "Road Waste Tire Rubber Powder" (JT / T798-2011); Preferably, the softening point of the liquid coumarone resin is 5°C-25°C; Preferably, the dibenzothiazyl disulfide has a melting point greater than 164°C, an ash content less than or equal to 0.5%, and a maximum particle size less than or equal to 0.005 mm; Preferably, the octadecanethiol has a purity greater than or equal to 98%, a melting point of 30°C-33°C, and a maximum particle size less than or equal to 0.075 mm; Preferably, the rubber cracking agent is a liquid with a purity greater than or equal to 99% and a relative density (20 / 4°C) of 0.7-0.9; Preferably, the maximum particle size of the deodorant is less than or equal to 15 μm, the solid content is greater than or equal to 99%, and the water-soluble content is less than or equal to 0.5%; Preferably, the maximum particle size of the powdered styrene-butadiene rubber is less than or equal to 0.3 mm, and the average molecular weight is 200,000-300,000; Preferably, the sulfur is in powder form, with a maximum particle size of less than or equal to 0.15 mm, and other performance indicators meet the requirements of superior products in "Industrial Sulfur" (GB / T2449-2006). Preferably, the rubber asphalt masterbatch is mainly prepared by the following steps: Step 1, weighing in proportion, adding anti-rutting masterbatch, furfural extracted oil, waste tire rubber powder, liquid coumarone resin, dibenzothiazole disulfide, octadecyl mercaptan, rubber cracking agent and deodorant into a pressure reactor, and stirring for 5-10 minutes; Step 2, heating the product obtained in step 1 to 200°C-230°C and maintaining a pressure of 1Mpa; Step 3, the product obtained in step 2 is sheared continuously for 240 min-360 min using a fast shearing machine under the condition of constant temperature and pressure, and the speed of the shearing machine is greater than or equal to 2900 rpm; Step 4, restoring the product obtained in step 3 to standard atmospheric pressure and reducing the temperature to 190° C.-195° C.; Step 5, adding the powdered styrene-butadiene rubber into the product obtained in step 4, maintaining 190° C.-195° C., and continuously rapid shearing for 30 min-60 min, with the speed of the shearing machine being greater than or equal to 2900 rpm; Step 6, putting the product obtained in step 5 into a steel belt granulator for granulation; Step 7, cooling the product obtained in step 6 to below 30° C.; Step eight, fully mixing the product obtained in step seven with sulfur to obtain rubber asphalt masterbatch.

2. The method for preparing stable rubber asphalt using rubber asphalt masterbatch according to claim 1, characterized in that: The following steps are involved: Step 1: weigh the base asphalt used to produce the stabilized rubber asphalt according to the proportion, and heat it to 150° C.-170° C.; Step 2, weighing the rubber asphalt masterbatch according to the proportion, and adding the rubber asphalt masterbatch into the product obtained in step 1; Step 3: Heat the product obtained in step 2 to 185°C-195°C and continue stirring for 45min-60min to obtain a stable rubber asphalt.

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