A direct-injection high-modulus polymer asphalt modifier and its preparation method and application

Abstract

The present invention discloses a direct-injection high-modulus polymer asphalt modifier, which is mainly prepared from the following components by weight: 25-55 parts of PTW resin, 30-45 parts of PCTA resin, 4-15 parts of APAO-g-MAH resin compatibilizer, and 3-10 parts of core-shell butadiene rubber. The melt index of the PTW resin is 12g / 10min at 190°C and a load of 2.16kg. The specific gravity of the PCTA resin is 1.2g / cm 3 , Rockwell hardness R grade 103. Based on the same inventive concept, the present invention also provides a method for preparing a direct-cast high-modulus polymer asphalt modifier. The present invention also provides the use of a direct-cast high-modulus polymer asphalt modifier or asphalt mixture as a road building material in road maintenance or road construction. The present invention solves the problem of pavement damage by introducing a high-fluidity polymer alloy crosslinking agent to improve the adhesion between the surface layer and the middle and lower layers, increase the crosslinking degree and pavement toughness, and add a high-strength and high-toughness resin and an impact modifier.

Description

Technical Field

[0001] The present invention relates to the field of asphalt modification, and in particular to a direct-injection high-modulus polymer asphalt modifier, a preparation method thereof, and applications thereof. Background Art

[0002] Asphalt pavement currently accounts for a significant portion of my country's road surface, with virtually all highways paved with asphalt. The renovation and maintenance of older roads also requires significant amounts of asphalt. The production of asphalt pavement is an energy-intensive and highly polluting process, requiring significant amounts of stone, asphalt, and fuel. This process not only generates significant amounts of harmful gases and dust, but also pollutes the environment and impacts health. With increasing awareness of environmental protection and sustainability, the environmental performance and sustainability of asphalt materials have become crucial considerations. The development of resource-efficient, environmentally friendly, and eco-friendly pavements is the inevitable path forward for future pavement development. Direct-injection high-modulus modified asphalt technology is an emerging asphalt modification technology. It is prepared by directly mixing the direct-injection high-modulus asphalt modifier with heated aggregate and then spraying it with high-temperature asphalt for stirring. Direct-injection high-modulus modified asphalt technology has the characteristics of simple process, energy saving, low cost, and high construction efficiency. Direct-injection asphalt mixture not only meets the requirements of national standards, but also meets the current environmental protection and economic requirements. However, ordinary direct-injection high-modulus modified asphalt has certain defects due to the poor adhesion between the surface layer and the middle and lower layers, which is prone to pavement pumping, pavement peeling and pitting, pavement delamination and separation, etc.

[0003] Therefore, the existing technology is in urgent need of improvement. Summary of the Invention

[0004] The present invention addresses the shortcomings of existing technologies by providing a direct-injection high-modulus polymer asphalt modifier, its preparation method, and its application. This invention addresses the aforementioned problems by introducing a high-flow polymer alloy crosslinker to improve adhesion between the surface layer and the middle and lower layers, increasing the degree of crosslinking and pavement toughness. Furthermore, the invention incorporates a high-strength, high-toughness resin and an impact modifier to improve the toughness of the pavement.

[0005] The technical solution of the present invention is achieved as follows:

[0006] A direct-injection high-modulus polymer asphalt modifier is primarily prepared from the following components in parts by weight: 25-55 parts PTW resin, 30-45 parts PCTA resin, 4-15 parts APAO-g-MAH resin compatibilizer, and 3-10 parts core-shell butadiene rubber. Of course, other additives may be added as appropriate depending on the specific application environment. Preferably, a direct-injection high-modulus polymer asphalt modifier is primarily prepared from the following components in parts by weight: 39-55 parts PTW resin, 31-45 parts PCTA resin, 5-12 parts APAO-g-MAH resin compatibilizer, and 3-9 parts core-shell butadiene rubber.

[0007] PCTA resin, short for copolymer of terephthalic acid, isophthalic acid, and 1,4-cyclohexanedimethanol, has a benzene ring structure and a cycloalkane structure, resulting in high molecular chain rigidity and a large molecular weight. The addition of isophthalic acid reduces the regularity of the molecular chain, maintaining high modulus while also providing impact resistance. This effectively increases the modulus and viscosity of modified asphalt, while also improving its toughness. Its high melt index imparts improved dispersibility and coating properties. Furthermore, its stable ring structure imparts excellent weather resistance and aging resistance to the modified asphalt.

[0008] PTW resin is a terpolymer of ethylene / butyl acrylate / glycidyl acrylate. Its esters, due to their similar polarity to asphalt, are more easily dispersed in the asphalt phase, effectively reducing the surface tension of asphalt. This improves the stretchability of the PCTA macromolecular chains and allows for better dispersion in the recycled asphalt petroleum system, endowing the present invention's direct-injection high-modulus polymer asphalt modifier with excellent storage stability and dispersibility. Furthermore, the PTW resin's flexible molecular chain structure offers excellent ductility, elongation at break, and elasticity, enhancing asphalt's fatigue resistance and high-temperature rutting resistance. PTW resin also possesses highly reactive epoxy groups.

[0009] APAO-g-MAH resin is an amorphous poly-α-olefin copolymer grafted with maleic anhydride. Its polyolefin structure is similar to the ethylene structure of PTW resin, which improves dispersibility and compatibility with the modifier-asphalt. The strong polarity of maleic anhydride also enhances its own dispersibility and compatibility in asphalt. It also improves the interfacial affinity between aggregate and stone and asphalt, ensuring thorough mixing of the aggregate and enhancing the penetration of asphalt molecules. This allows for a tighter packing of the asphalt mixture with the aggregate and stone, reducing porosity. Furthermore, under the influence of high temperature and screw shear, its anhydride groups undergo a broad dehydration reaction with the residual polar hydroxyl groups in the PCTA resin to form carboxylic acid groups, enhancing the compatibility of the PCTA resin in the asphalt dispersion. Furthermore, the anhydride groups react with free amino groups in the asphalt to generate new carboxylic acid groups.

[0010] Core-shell butadiene rubber, a core-shell butadiene rubber bisphenol A epoxy toughening agent, has a unique core-shell structure with high impact resistance and cushioning effect, which effectively improves toughness. In addition, its active epoxy groups and the active epoxy groups in PTW can react with the carboxylic acid groups and hydroxyl groups in PCTA resin at high temperature to improve the dispersibility and stability of PCTA resin. On the other hand, they can react with the carboxylic acid groups, amino groups, and phenolic hydroxyl groups in asphalt. At the same time, they can also react with the carboxylic acid groups generated by the APAO-g-MAH reaction. Finally, they synergize with other components in the asphalt phase to generate a high-modulus asphalt modifier with high dispersibility and stability and a complex network cross-linked structure.

[0011] As described above, the direct-cast high modulus polymer asphalt modifier, the PTW resin is an ethylene / butyl acrylate / glycidyl acrylate terpolymer, and its melt index is 10-12 g / 10 min at 190°C and a load of 2.16 kg. Under this performance, the aliphatic polyester of the PTW resin can significantly reduce the surface tension of asphalt due to its polarity similar to that of asphalt, and improve the compatibility and dispersibility of the PCTA resin in the asphalt mixture. The PTW resin also has a toughening effect and exhibits high viscosity and high elasticity. Preferably, the PTW resin is an ethylene / butyl acrylate / glycidyl acrylate terpolymer produced by Dow Chemical Company of the United States. More preferably, the PTW resin is produced by Dow Chemical Company of the United States. PTW, with a melting point of 72°C, has a melt index of 12g / 10min and a density of 0.94g / cm3 at 190°C and a load of 2.16kg. 3 .

[0012] The direct-cast high modulus polymer asphalt modifier as described above, the PCTA resin is a copolymer of ethylene terephthalate, isophthalic acid, and 1,4-cyclohexanedimethanol, and its density is 1.2 g / cm 3 , Rockwell hardness R grade 103. Under this scheme, its benzene ring structure and cycloalkane structure molecular chain have high rigidity and large molecular weight. The addition of isophthalic acid reduces the regularity of the molecular chain, ensuring high modulus while also having impact resistance. It can effectively improve the modulus of modified asphalt while improving the viscosity and toughness of modified asphalt. Its high melt index (high fluidity) has better dispersibility in aggregate stones. Preferably, the PCTA resin adopts AN004 from American Eastman Chemical Co., Ltd., with a density of 1.2g / cm 3 , Rockwell hardness R grade 103, at 190℃, load is 2.16KG, melt index is 25~40g / 10min.

[0013] As the above-mentioned direct-cast high modulus polymer asphalt modifier, the APAO-g-MAH resin is an amorphous poly-α-olefin copolymer grafted with maleic anhydride. Preferably, the density of the APAO-g-MAH resin is 0.98 g / cm 3 The glass transition temperature is -32°C; the grafting rate is 2-4%, preferably 2.6%. In this solution, APAO-g-MAH resin acts as a reactive compatibilizer, enhancing the compatibility and dispersibility of the modifier and asphalt. It also improves the interfacial affinity between the aggregate and the asphalt. Thorough mixing with the aggregate enhances the penetration of asphalt molecules, tightly encapsulating the asphalt mixture and the aggregate, reducing the void content.

[0014] The direct-injection high-modulus polymer asphalt modifier described above, wherein the core-shell butadiene rubber is a core-shell butadiene rubber bisphenol A epoxy toughening agent. Preferably, the core-shell butadiene rubber is MX154 provided by Kaneka Chemical Co., Ltd. of Japan, having an epoxy equivalent weight of 301 g / eq, a viscosity (50°C) of 25,000 mPa.s, and a CSR active ingredient content of 40 wt%. Under this solution, the core-shell butadiene rubber has high reactivity, and the core-shell structure has high impact resistance and cushioning effect.

[0015] Based on the same inventive concept, the present invention provides a method for preparing a direct-injection high modulus polymer asphalt modifier, comprising the following steps:

[0016] Step 1: PTW resin and PCTA resin are fully mixed in a high-speed mixer according to a set ratio to obtain material 1; preferably, in step 1, the mixing speed is 300-500 rpm and the mixing time is 20-30 min; more preferably, in step 1, the mixing speed is 300 rpm and the mixing time is 20 min;

[0017] Step 2: adding APAO-g-MAH resin to material 1 in a set ratio and mixing uniformly in a high-speed mixer to obtain material 2; preferably, in step 2, the mixing speed is 300-500 rpm and the mixing time is 20-30 min; more preferably, in step 2, the mixing speed is 400 rpm and the mixing time is 25 min;

[0018] Step 3: adding the core-shell butadiene rubber to material 2 in a set ratio and mixing them evenly in a high-speed mixer to obtain material 3; preferably, in step 3, the mixing speed is 300-500 rpm and the mixing time is 20-30 min; more preferably, in step 3, the mixing speed is 400 rpm and the mixing time is 30 min;

[0019] Step 4: Feed material 3 from step 3 through the main feed port into a parallel twin-screw extruder for extrusion and pelletization. The pelletizer is then water-cooled and pelletized. After drying, a direct-injection high-modulus polymer asphalt modifier is obtained. Preferably, the pelletizing temperature is 200°C and the screw speed is 500 rpm. Preferably, the drying step comprises water-cooled pelletizing followed by drying in a dryer. More preferably, the drying step comprises water-cooled pelletizing followed by microwave hot air drying at 55°C. These conditions result in rapid drying, energy conservation, and high efficiency.

[0020] Based on the same inventive concept, the present invention also provides an asphalt mixture using the above-described direct-injection high-modulus polymer asphalt modifier or the direct-injection high-modulus polymer asphalt modifier prepared by the above-described preparation method. The mass fraction of the direct-injection high-modulus polymer asphalt modifier in the modified asphalt mixture is 0.7% to 1.1%. Preferably, the mass fraction of the direct-injection high-modulus polymer asphalt modifier in the modified asphalt mixture is 0.8% to 0.9%.

[0021] Based on the same inventive concept, the present invention also provides the use of a direct-injection high modulus polymer asphalt modifier as described above, or a direct-injection high modulus polymer asphalt modifier prepared by the preparation method as described above, or an asphalt mixture as described above as a road construction material in road maintenance or road construction.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention provides a direct-cast high-modulus polymer asphalt modifier, which is mainly prepared from the following components: PTW resin, PCTA resin, APAO-g-MAH resin compatibilizer, and core-shell butadiene rubber. The active epoxy groups in the core-shell butadiene rubber and PTW can react with the carboxylic acid groups and hydroxyl groups in the PCTA resin at high temperatures, improving the dispersibility and stability of the PCTA resin. On the other hand, they can react with the carboxylic acid groups, amino groups, and phenolic hydroxyl groups in the asphalt. They can also react with the carboxylic acid groups generated by the reaction of APAO-g-MAH with free amino groups in asphaltene, further improving the dispersibility and stability of the direct-cast high-modulus asphalt modifier. The strong polarity of maleic anhydride in APAO-g-MAH improves its own dispersibility and compatibility in asphalt, and can also improve the interfacial affinity between aggregate and asphalt. When fully mixed with the aggregate, the penetration ability of asphalt molecules is enhanced, and the asphalt mixture and aggregate are tightly wrapped, reducing the void ratio.

[0024] 2. Since the modifier of the present invention has better dispersibility, it can be directly added to the mixing pot at the construction site and mixed with aggregate and ordinary asphalt in a short time to produce a modified asphalt mixture, which simplifies the construction process and shortens the construction period.

[0025] 3. PCTA resin is a non-crystalline copolyester with both benzene rings and a rigid cycloalkyl structure. Its high molecular chain rigidity and high molecular weight contribute to improving the modulus of modified asphalt. The synergistic effect of the highly dispersed cross-linking system enables this direct-injection high-modulus polymer asphalt modifier to achieve high modulus performance with minimal usage. Furthermore, the stable ring structure of PCTA resin imparts excellent weather resistance and aging resistance to the modified asphalt.

[0026] 4. The flexible molecular chain structure of PTW resin also provides toughening. The unique core-shell structure of core-shell butadiene rubber also contributes to impact toughening in the modifier of this invention. The stable ring structure of PCTA resin has excellent impact resistance. The direct-injection high-modulus polymer asphalt modifier of this invention has excellent impact toughening properties. DETAILED DESCRIPTION

[0027] The following will be combined with the contents of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are intended solely for the purpose of describing specific embodiments and are not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0030] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0031] In the following examples, PTW resin was obtained from Dow Chemical Company, USA. PTW has a melting point of 72°C, a melt index of 12g / 10min at 190°C and a load of 2.16kg, and a density of 0.94g / cm 3 The PCTA resin used is AN004 from American Eastman Chemical Co., Ltd., with a density of 1.2g / cm 3 , Rockwell hardness R grade 103, 230 ℃, load 2.16KG, melt index 25 ~ 40g / 10min. APAO-g-MAH resin uses APAO-J M202 from Hangzhou Henkel New Materials Technology Co., Ltd., with a density of 0.98g / cm 3 Glass transition temperature: -32°C; grafting rate: 2-4%. The actual grafting rate of the product in this example is 2.6%. The core-shell butadiene rubber is MX154 from Kaneka Chemical Co., Ltd., Japan, with an epoxy equivalent weight of 301 g / eq, a viscosity (50°C): 25,000 mPa·s, and a CSR active ingredient content of 40 wt%.

[0032] Example 1:

[0033] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components in parts by weight: 53 parts of PTW resin, 32 parts of PCTA resin, 8 parts of APAO-g-MAH resin, and 7 parts of core-shell butadiene rubber.

[0034] The preparation method of the direct-injection high modulus asphalt modifier is as follows:

[0035] Step 1: 53 parts of PTW resin and 32 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 300 rpm for 20 min to obtain material 1;

[0036] Step 2: Add 8 parts of APAO-g-MAH resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0037] Step 3: Add 7 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0038] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 55°C. After drying, a direct-injection high modulus asphalt modifier is obtained.

[0039] Example 2:

[0040] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components in parts by weight: 40 parts of PTW resin, 45 parts of PCTA resin, 8 parts of APAO-g-MAH resin compatibilizer, and 7 parts of core-shell butadiene rubber.

[0041] The preparation method of the direct-injection high modulus polymer asphalt modifier is as follows:

[0042] Step 1: 40 parts of PTW resin and 45 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 1;

[0043] Step 2: Add 8 parts of APAO-g-MAH resin compatibilizer to material 1 and mix evenly in a high-speed mixer at a mixing speed of 300 rpm for 25 min to obtain material 2;

[0044] Step 3: Add 7 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0045] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 400rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 45°C. After drying, a direct-injection high modulus polymer asphalt modifier is obtained.

[0046] Example 3:

[0047] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components in parts by weight: 44 parts of PTW resin, 40 parts of PCTA resin, 12 parts of APAO-g-MAH resin compatibilizer, and 3 parts of core-shell butadiene rubber.

[0048] The preparation method of the direct-injection high modulus polymer asphalt modifier is as follows:

[0049] Step 1: 44 parts of PTW resin and 40 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 1;

[0050] Step 2: Add 12 parts of APAO-g-MAH resin compatibilizer to material 1 and mix evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0051] Step 3: Add 3 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 3;

[0052] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 300rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 65°C. After drying, a direct-injection high modulus polymer asphalt modifier is obtained.

[0053] Example 4:

[0054] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components in parts by weight: 55 parts of PTW resin, 31 parts of PCTA resin, 5 parts of APAO-g-MAH resin compatibilizer, and 9 parts of core-shell butadiene rubber.

[0055] The preparation method of the direct-injection high modulus polymer asphalt modifier is as follows:

[0056] Step 1: 55 parts of PTW resin and 31 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 1;

[0057] Step 2: Add 5 parts of APAO-g-MAH resin compatibilizer to material 1 and mix evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0058] Step 3: Add 9 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 3;

[0059] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 400rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 65°C. After drying, a direct-injection high modulus polymer asphalt modifier is obtained.

[0060] Example 5:

[0061] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components in parts by weight: 39 parts of PTW resin, 40 parts of PCTA resin, 12 parts of APAO-g-MAH resin compatibilizer, and 9 parts of core-shell butadiene rubber.

[0062] The preparation method of the direct-injection high modulus polymer asphalt modifier is as follows:

[0063] Step 1: 39 parts of PTW resin and 40 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 500 rpm for 25 min to obtain material 1;

[0064] Step 2: Add 12 parts of APAO-g-MAH resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 2;

[0065] Step 3: Add 9 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 500 rpm for 20 min to obtain material 3;

[0066] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 65°C. After drying, a direct-injection high modulus polymer asphalt modifier is obtained.

[0067] Comparative Example 1:

[0068] An asphalt modifier is mainly prepared from the following components by weight: 53 parts of PE resin, 32 parts of PCTA resin, 8 parts of APAO-g-MAH resin, and 7 parts of core-shell butadiene rubber. The PE resin is LG Chemical's HDPE ME5000 with a density of 0.952 g / cm 3 The melt index was 5 g / 10 min at 2.16 kg and 190° C. The same PCTA resin, APAO-g-MAH resin, and core-shell butadiene rubber as in Example 1 were used.

[0069] The preparation method of the asphalt modifier is as follows:

[0070] Step 1: 53 parts of PE resin and 32 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 300 rpm for 20 min to obtain material 1;

[0071] Step 2: Add 8 parts of APAO-g-MAH resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0072] Step 3: Add 7 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0073] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500 rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 55°C to obtain an asphalt modifier.

[0074] Comparative Example 2:

[0075] An asphalt modifier is mainly prepared from the following components by weight: 53 parts of PTW resin, 32 parts of PET resin, 8 parts of APAO-g-MAH resin compatibilizer, and 7 parts of core-shell butadiene rubber. RE5264NC010, density 1.64 g / cm 3 , the melt volume flow rate is 16.cm 3 The same PTW resin, APAO-g-MAH resin compatibilizer, and core-shell butadiene rubber as in Example 1 were used.

[0076] The preparation method of the asphalt modifier is as follows:

[0077] Step 1: 53 parts of PTW resin and 32 parts of PET resin were mixed evenly in a high-speed mixer at a mixing speed of 300 rpm for 20 min to obtain material 1;

[0078] Step 2: Add 8 parts of APAO-g-MAH resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0079] Step 3: Add 7 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0080] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500 rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 55°C to obtain an asphalt modifier.

[0081] Comparative Example 3:

[0082] An asphalt modifier is mainly prepared from the following components in parts by weight: 53 parts of PTW resin, 32 parts of PCTA resin, 8 parts of APAO resin, and 7 parts of core-shell butadiene rubber, wherein the APAO resin is VESTOPLAST703 produced by Evonik of Germany, with a melt viscosity of 2700±700 mpas at 190°C and a softening point (ring and ball method) of 124±6°C. The same PTW resin, PCTA resin, and core-shell butadiene rubber as those in Example 1 are used.

[0083] The preparation method of the asphalt modifier is as follows:

[0084] Step 1: 53 parts of PTW resin and 32 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 300 rpm for 20 min to obtain material 1;

[0085] Step 2: Add 8 parts of APAO resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0086] Step 3: Add 7 parts of core-shell butadiene rubber to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0087] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500 rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 55°C to obtain an asphalt modifier.

[0088] Comparative Example 4:

[0089] A direct-injection high-modulus polymer asphalt modifier is mainly prepared from the following components by weight: 53 parts of PTW resin, 32 parts of PCTA resin, 8 parts of APAO-g-MAH resin, and 7 parts of MBS resin. MBS resin is a terpolymer of methyl methacrylate, butadiene, and styrene, and uses EM500 from LG Chemical of South Korea with a density of 1.05-1.10 g / cm 3 The melt index is 17.5 g / 10 min when tested under a load of 1.2 kg and at 300° C. The same PTW resin, PCTA resin, and APAO-g-MAH resin compatibilizer as in Example 1 are used.

[0090] The preparation method of the asphalt modifier is as follows:

[0091] Step 1: 53 parts of PTW resin and 32 parts of PCTA resin were mixed evenly in a high-speed mixer at a mixing speed of 300 rpm for 20 min to obtain material 1;

[0092] Step 2: Add 8 parts of APAO-g-MAH resin to material 1 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 25 min to obtain material 2;

[0093] Step 3: Add 7 parts of MBS resin to material 2 and mix them evenly in a high-speed mixer at a mixing speed of 400 rpm for 30 min to obtain material 3;

[0094] Step 4: Add material 3 in step 3 from the main feed port to a parallel twin-screw extruder for granulation. The granulation temperature is 200°C, the screw speed is 500 rpm, and water-cooled pelletizing is used. The obtained pellets are dried with microwave hot air at 55°C to obtain an asphalt modifier.

[0095] The direct-injection high-modulus polymer asphalt modifier of the present invention and the comparative asphalt modifier were evaluated by testing the performance indicators of the prepared modified asphalt mixture. Preferably, the mass fraction of the added modifier in the prepared modified asphalt mixture was 0.86%. The asphalt was sourced from Jingbo Petrochemical Co., Ltd., and the test results of various indicators were as follows: needle penetration (0.1mm): 60-80, elongation at 10°C (cm): 20, softening point (°C): 46, solubility (%): 99.5, and dynamic viscosity at 60°C Pa·s: 180. The asphalt mixture was prepared by heating the stone aggregate to 185°C, adding the asphalt modifier and stirring for 30 seconds, and then spraying the heated asphalt at 165°C and stirring for 45 seconds to prepare the modified asphalt mixture.

[0096] Asphalt mixtures were tested for various relevant indicators according to the JTGE20-2011 Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering. However, direct-injection production methods are not widely adopted, and there are no corresponding national or industry standards. To better test the dispersion of the modifier at production temperatures and its coating dispersion performance, we conducted tests simulating an on-site production process.

[0097] Gravel Aggregate Dispersion Test Method: 500g of washed aggregate was dried in an oven at 185°C for 5 hours. 4.5g of modifier was quickly added and stirred vigorously. The modifier's melting and adhesion to the aggregate surface were observed. In this test, 1% Pigment Red 254 was added to the modifier during extrusion to distinguish it from the aggregate. Two sets of tests were conducted, with stirring for 30s and 45s, and the test results of each example and comparative example were evaluated according to the following dissolution and coating effect grading criteria: ① Good coating: The modifier completely melted, and the aggregate surface was evenly coated, showing a uniform red color; ② Fair coating: The modifier melted, but had poor fluidity, with partial coating, and the coated aggregate easily agglomerated; ③ Difficult to coat (poor): The modifier did not melt, and the particles did not deform.

[0098] Table 1 Melt coating performance test results

[0099]

[0100] Comparison of Melt Coating Properties: Examples 1-5 outperform Comparative Examples 1-4, demonstrating that the direct-cast high-modulus polymer asphalt modifier provided by the present invention exhibits significantly improved flowability, dispersibility, and film-forming properties. Comparison of Comparative Example 2 with Example 1 demonstrates that the PCTA melt index significantly influences the modifier's melt coating properties, with good melt coating properties requiring a relatively high PCTA melt index.

[0101] In order to characterize the performance of the direct-injection high modulus polymer asphalt modifiers prepared in Examples 1 to 5 and compare them with the modifiers of Comparative Examples 1 to 4, the asphalt mixtures prepared using different modifiers of Examples 1 to 5 and Comparative Examples 1 to 4 were subjected to performance tests. The specific test evaluation results are shown in Table 2.

[0102] A standard asphalt mixture sample was prepared and tested according to GB / T 36143-2018 High Modulus Fatigue-Resistant Asphalt Mixture for Road Use. The asphalt-to-stone ratio of the modified asphalt mixture was 5%.

[0103] Table 2 Evaluation results of modified asphalt mixture

[0104]

[0105] As shown in Table 2, the dynamic stability performance of Examples 1 to 5 is significantly improved compared with that of Comparative Examples 1 to 4, indicating that the asphalt mixture prepared using the modifier of the present invention has significant anti-rutting performance. The freeze-splitting residual strength of Examples 1 to 5 is significantly improved compared with that of Comparative Examples 1 to 4, indicating that the asphalt mixture prepared using the modifier of the present invention has good adhesion.

[0106] The test results in Tables 1 and 2 for Examples 1 to 5 and Comparative Examples 1 to 4 demonstrate that the asphalt mixtures containing the direct-injection high-modulus asphalt modifier of the present invention exhibit high dispersibility and effectively alleviate rutting. This means that the four components—PTW resin, PCTA resin, APAO-g-MAH resin compatibilizer, and core-shell butadiene rubber—must be used in combination to achieve the material's comprehensive performance. Substituting similar components will not achieve the superior results of the present invention.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A direct-injection high modulus polymer asphalt modifier, characterized in that: The invention is mainly prepared from the following components in parts by weight: 25 to 55 parts of PTW resin, 30 to 45 parts of PCTA resin, 4 to 15 parts of APAO-g-MAH resin compatibilizer, and 3 to 10 parts of core-shell butadiene rubber; the core-shell butadiene rubber is a core-shell butadiene rubber bisphenol A epoxy toughening agent.

2. The direct-injection high modulus polymer asphalt modifier according to claim 1, characterized in that: The melt index of the PTW resin is 10-12 g / 10 min at 190° C. and a load of 2.16 kg.

3. The direct-injection high modulus polymer asphalt modifier according to claim 1, characterized in that: The PCTA resin has a density of 1.2 g / cm³ and a Rockwell hardness R grade of 103. Its melt index is 25 to 40 g / 10 min at 190° C. and a load of 2.16 kg.

4. The direct-injection high modulus polymer asphalt modifier according to claim 1, characterized in that: The APAO-g-MAH resin has a density of 0.98 g / cm3, a glass transition temperature of -32°C, and a grafting rate of 2-4%.

5. The direct injection high modulus polymer asphalt modifier according to claim 1, characterized in that: The core-shell butadiene rubber has an epoxy equivalent of 301 g / eq, a viscosity at 50° C. of 25,000 mPa.s, and a CSR active ingredient content of 40 wt %.

6. The method for preparing a direct-injection high modulus polymer asphalt modifier according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: PTW resin and PCTA resin are mixed uniformly in a high-speed mixer according to a set ratio to obtain material 1; Step 2: Add APAO-g-MAH resin to material 1 in a high-speed mixer according to a set ratio and mix evenly to obtain material 2; Step 3: adding the core-shell butadiene rubber to material 2 in a set ratio and mixing them evenly in a high-speed mixer to obtain material 3; Step 4: Add the material 3 in step 3 from the main feeding port into the parallel twin-screw extruder for extrusion and granulation, adopt water-cooling granulation, and obtain the direct-injection high modulus asphalt modifier after drying.

7. An asphalt mixture, characterized in that: The direct-injection high modulus polymer asphalt modifier described in claims 1 to 5 or the direct-injection high modulus polymer asphalt modifier prepared by the preparation method described in claim 6 is used.

8. The asphalt mixture according to claim 7, characterized in that: The mass fraction of the direct-injection high modulus polymer asphalt modifier in the asphalt mixture is 0.7% to 1.1%.

9. Use of the direct-injection high modulus polymer asphalt modifier according to any one of claims 1 to 5, the direct-injection high modulus polymer asphalt modifier prepared by the preparation method according to claim 6, or the asphalt mixture according to claim 8 as a road construction material in road maintenance or road construction.

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