Preparation method of adhesive for 3PE anti-corrosion pipeline

Abstract

The invention discloses an adhesive for a 3PE anticorrosive pipeline, and relates to the technical field of anticorrosive materials, the adhesive is prepared from the following raw materials by weight: 60-80 parts of matrix resin, 10-15 parts of a tackifier, 5-8 parts of hydroxyl-terminated hyperbranched polyurethane, 5-10 parts of MBS resin, 2-5 parts of a nano hybrid filler, 0.5-0.8 part of a coupling agent, 0.5-1.5 parts of an antioxidant, 1-3 parts of a processing aid, and 3-6 parts of a polarity regulator. The adhesive has the advantages of high adhesive force, excellent temperature resistance and corrosion resistance, simple preparation process and controllable cost.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion materials technology, and in particular to a method for preparing a 3PE anti-corrosion pipe adhesive. Background Technology

[0002] 3PE anti-corrosion pipelines have become the mainstream anti-corrosion solution for oil and gas pipelines due to their excellent corrosion resistance, impact resistance, and long service life. Their structure, from the inside out, consists of an epoxy powder primer, an adhesive layer, and a polyethylene anti-corrosion layer. The adhesive layer, as the core bonding component of the 3PE anti-corrosion coating, plays a crucial role in connecting the epoxy coating to the polyethylene outer sheath. Its bonding performance directly determines the overall integrity and anti-corrosion reliability of the 3PE anti-corrosion coating.

[0003] Existing 3PE anti-corrosion pipe adhesives are mostly made of ordinary copolyolefin resins with the addition of a small amount of tackifier. However, these adhesives have many shortcomings in practical applications: Firstly, ordinary copolyolefins have low polarity, resulting in weak interfacial forces with the highly polar epoxy coating, leading to insufficient adhesion between the adhesive and the epoxy coating. During pipeline transportation, laying, and long-term use, problems such as coating peeling and lifting are prone to occur, which in turn allows corrosive media to penetrate and affects the anti-corrosion effect. Secondly, existing adhesives have poor temperature resistance. When the pipeline is used for transporting high-temperature media (such as hot water and hot oil pipelines), the adhesive is prone to softening and degradation, resulting in a significant decrease in bonding strength and failing to meet the requirements of high-temperature operating conditions.

[0004] To address the aforementioned issues, Chinese invention patent CN103468180B discloses a method for preparing a 3PE anti-corrosion pipe adhesive. The method involves mixing a matrix resin, grafting monomer, and initiator in a low-speed mixer, followed by extrusion granulation using a twin-screw extruder to obtain a polyethylene graft masterbatch. Then, 20-40 parts of the polyethylene graft masterbatch, 15-30 parts of high-density polyethylene, 0-10 parts of low-density polyethylene, 20-50 parts of linear low-density polyethylene, and 5-35 parts of tackifier are mixed to obtain a final product. An antioxidant of 0.1-1% of the total weight of the mixture is added, and the mixture is then homogenized in a high-speed mixer and extruded and granulated using a twin-screw extruder to obtain the target product, the 3PE anti-corrosion pipe adhesive. This invention features a simple formulation and process, high product cost-effectiveness, and suitability for large-scale continuous batch production. The low addition of grafting monomer and initiator significantly reduces environmental pollution and has broad application prospects. However, this adhesive still suffers from low bond strength retention at high temperatures and poor long-term adhesion stability with epoxy coatings.

[0005] Therefore, developing a method for preparing an adhesive for 3PE anti-corrosion pipelines that combines high adhesion, excellent temperature resistance and corrosion resistance, and has a simple preparation process and controllable cost is of great practical significance and application value for promoting the development of 3PE anti-corrosion pipeline technology and meeting the needs of pipeline corrosion protection under different working conditions. Summary of the Invention

[0006] To address the technical problems of existing 3PE anti-corrosion pipe adhesives, such as poor adhesion to epoxy and polyethylene coatings, insufficient temperature resistance, and poor corrosion resistance, as well as the high cost and complex processes of some improvement solutions making them difficult to industrialize, this invention provides a method for preparing a 3PE anti-corrosion pipe adhesive. Through reasonable raw material selection, modification design, and process parameter optimization, an adhesive with excellent comprehensive performance is prepared, thus solving the above-mentioned technical pain points.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a 3PE anti-corrosion pipe adhesive, comprising the following raw materials in parts by weight: 60-80 parts of matrix resin, 10-15 parts of tackifier, 5-8 parts of hydroxyl-terminated hyperbranched polyurethane, 5-10 parts of MBS resin, 2-5 parts of nano-hybrid filler, 0.5-0.8 parts of coupling agent, 0.5-1.5 parts of antioxidant, 1-3 parts of processing aid, and 3-6 parts of polarity modifier.

[0008] Preferably, the matrix resin is maleic anhydride-grafted polyethylene 900E.

[0009] Preferably, the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of (3-5):1.

[0010] Preferably, the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, and is provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0011] Preferably, the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.

[0012] Preferably, the nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 20-60 nm.

[0013] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; and the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0014] Preferably, the processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:(0.8-1.2).

[0015] Preferably, the polarity modifier is an ethylene-vinyl acetate copolymer.

[0016] Preferably, the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0017] Another objective of this invention is to provide a method for preparing the 3PE anti-corrosion pipe adhesive, comprising the following steps: mixing each raw material evenly according to the weight parts to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently extruding the molten material through a die and granulating it by water cooling pelletizing to obtain the 3PE anti-corrosion pipe adhesive.

[0018] Preferably, the temperatures of each section of the twin-screw extruder are as follows: feeding section 150-170℃, compression section 170-190℃, homogenization section 190-210℃, die head 200-220℃, and screw speed 150-250 r / min.

[0019] Preferably, the cooling water temperature for the water-cooled pelletizing is 20-30℃, and the pelletizing speed is 200-300 r / min.

[0020] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The 3PE anti-corrosion pipe adhesive disclosed in this invention breaks through the technical bottleneck of the prior art in which it is difficult to balance the polarity adjustment and compatibility improvement of adhesives through the synergistic compounding of hydroxyl-terminated hyperbranched polyurethane and MBS resin, and achieves a breakthrough improvement in interfacial bonding performance. The hydroxyl-terminated hyperbranched polyurethane, with its unique branched structure, can form a strong interaction with the active groups on the surface of the epoxy coating. At the same time, the core-shell structure of MBS resin can effectively improve the compatibility between polar components and non-polar matrix resin. Under the synergistic effect of the two, the interfacial bonding force between the adhesive and the epoxy coating and polyethylene layer is significantly enhanced, the uniformity of interfacial bonding is improved, the phenomenon of local stress concentration is avoided, and the risk of coating peeling caused by external impact during pipeline transportation and laying is effectively suppressed. This solves the industry pain point that the coating is prone to peeling at stress concentration parts such as corners and welds in the prior art.

[0021] (2) The 3PE anti-corrosion pipe adhesive disclosed in this invention has a composite network structure formed by nano-hybrid fillers, matrix resin, and polarity modifier. This structure not only enhances the heat distortion temperature of the adhesive through the reinforcing effect of nanoparticles and improves the structural stability under high-temperature conditions, but also improves the toughness and impact resistance of the material through the dispersion strengthening effect of nanoparticles. This breakthrough in dual performance of "high-temperature stability and low-temperature crack resistance" makes the adhesive suitable for various extreme conditions such as high-temperature medium transportation and cold-region laying, greatly expanding the application scenarios of 3PE anti-corrosion pipes and far exceeding the limitations of existing technologies that can only meet the needs of conventional temperature conditions.

[0022] (3) The 3PE anti-corrosion pipe adhesive disclosed in this invention forms a dense physical barrier network through the uniform dispersion of nano-hybrid fillers, which can effectively prevent corrosive media from penetrating to the interface. At the same time, the synergistic effect of the hydroxyl-terminated hyperbranched polyurethane and the coupling agent enhances the bonding stability between the components and inhibits component migration. This composite system can maintain stable bonding performance and structural integrity under harsh environments such as long-term humid heat aging and immersion in oil and gas media, significantly extending the service life of the 3PE anti-corrosion coating and breaking the technical limitation of the rapid performance degradation of adhesives over long-term use in the prior art.

[0023] (4) The 3PE anti-corrosion pipe adhesive disclosed in this invention adopts a single melt blending extrusion process, which does not require additional modification reaction steps. Under optimized process parameters, each raw material can achieve full dispersion and synergistic effect. This simplified process does not lead to performance loss. On the contrary, it further improves the stability of product performance by reducing the risk of component degradation during processing. At the same time, all components in the raw material system are industrially mass-produced raw materials with controllable costs. This invention can meet the needs of large-scale continuous production and stably output high-performance products, providing strong support for the high-quality industrial application of 3PE anti-corrosion pipes. Detailed Implementation

[0024] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0025] Example 1 A 3PE anti-corrosion pipe adhesive is made from the following raw materials in parts by weight: 60 parts of matrix resin, 10 parts of tackifier, 5 parts of hydroxyl-terminated hyperbranched polyurethane, 5 parts of MBS resin, 2 parts of nano-hybrid filler, 0.5 parts of coupling agent, 0.5 parts of antioxidant, 1 part of processing aid, and 3 parts of polarity modifier.

[0026] The matrix resin is maleic anhydride-grafted polyethylene 900E; the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of 3:1; the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.; the nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 20nm; the coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:0.8; the polarity modifier is ethylene-vinyl acetate copolymer; the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0027] A method for preparing the 3PE anti-corrosion pipe adhesive includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain the 3PE anti-corrosion pipe adhesive; the temperatures of each section of the twin-screw extruder are: 150℃ for the feeding section, 170℃ for the compression section, 190℃ for the homogenization section, and 200℃ for the die head, with a screw speed of 150 r / min; the cooling water temperature for the water-cooled pelletizing is 20℃, and the pelletizing speed is 200 r / min.

[0028] Example 2 A 3PE anti-corrosion pipe adhesive is made from the following raw materials in parts by weight: 65 parts of matrix resin, 12 parts of tackifier, 6 parts of hydroxyl-terminated hyperbranched polyurethane, 6 parts of MBS resin, 3 parts of nano-hybrid filler, 0.6 parts of coupling agent, 0.7 parts of antioxidant, 1.5 parts of processing aid, and 4 parts of polarity modifier.

[0029] The matrix resin is maleic anhydride-grafted polyethylene 900E; the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of 3.5:1; the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.; the nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 30nm; the coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 168; the processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:0.9; the polarity modifier is ethylene-vinyl acetate copolymer; the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0030] A method for preparing the 3PE anti-corrosion pipe adhesive includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain the 3PE anti-corrosion pipe adhesive; the temperatures of each section of the twin-screw extruder are: 155℃ for the feeding section, 175℃ for the compression section, 195℃ for the homogenization section, and 205℃ for the die head, with a screw speed of 170 r / min; the cooling water temperature for the water-cooled pelletizing is 23℃, and the pelletizing speed is 230 r / min.

[0031] Example 3 A 3PE anti-corrosion pipe adhesive is made from the following raw materials in parts by weight: 70 parts of matrix resin, 13 parts of tackifier, 6.5 parts of hydroxyl-terminated hyperbranched polyurethane, 8 parts of MBS resin, 3.5 parts of nano-hybrid filler, 0.65 parts of coupling agent, 1 part of antioxidant, 2 parts of processing aid, and 4.5 parts of polarity modifier.

[0032] The matrix resin is maleic anhydride-grafted polyethylene 900E; the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of 4:1; the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.; the nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 40nm; the coupling agent is silane coupling agent KH570; the antioxidant is antioxidant 1010; the processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:1; the polarity modifier is ethylene-vinyl acetate copolymer; the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0033] A method for preparing the 3PE anti-corrosion pipe adhesive includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain the 3PE anti-corrosion pipe adhesive; the temperatures of each section of the twin-screw extruder are: 160℃ for the feeding section, 180℃ for the compression section, 200℃ for the homogenization section, and 210℃ for the die head, with a screw speed of 200 r / min; the cooling water temperature for the water-cooled pelletizing is 25℃, and the pelletizing speed is 250 r / min.

[0034] Example 4 A 3PE anti-corrosion pipe adhesive is made from the following raw materials in parts by weight: 75 parts matrix resin, 14 parts tackifier, 7.5 parts hydroxyl-terminated hyperbranched polyurethane, 9 parts MBS resin, 4.5 parts nano-hybrid filler, 0.75 parts coupling agent, 1.3 parts antioxidant, 2.5 parts processing aid, and 5.5 parts polarity modifier.

[0035] The matrix resin is maleic anhydride-grafted polyethylene 900E; the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of 4.5:1; the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.; the nano-hybrid filler is nano-silica, with an average particle size of 50nm; the coupling agent is a compound of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the antioxidant is antioxidant 1010 and antioxidant 168 in a mass ratio of 1: 3. The processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:1.1; the polarity modifier is an ethylene-vinyl acetate copolymer; the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0036] A method for preparing the 3PE anti-corrosion pipe adhesive includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain the 3PE anti-corrosion pipe adhesive; the temperatures of each section of the twin-screw extruder are: feeding section 165℃, compression section 185℃, homogenization section 205℃, die head 215℃, and the screw speed is 240 r / min; the cooling water temperature for the water-cooled pelletizing is 28℃, and the pelletizing speed is 290 r / min.

[0037] Example 5 A 3PE anti-corrosion pipe adhesive is made from the following raw materials in parts by weight: 80 parts of matrix resin, 15 parts of tackifier, 8 parts of hydroxyl-terminated hyperbranched polyurethane, 10 parts of MBS resin, 5 parts of nano-hybrid filler, 0.8 parts of coupling agent, 1.5 parts of antioxidant, 3 parts of processing aid, and 6 parts of polarity modifier.

[0038] The matrix resin is maleic anhydride-grafted polyethylene 900E; the tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of 5:1; the hydroxyl-terminated hyperbranched polyurethane is grade 2499, catalog number HXKJ2025, provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; the MBS resin is DENKA TH-21 MBS resin, provided by Vopak Chemical Materials Co., Ltd.; the nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 60nm; the coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:1.2; the polarity modifier is ethylene-vinyl acetate copolymer; the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

[0039] A method for preparing the 3PE anti-corrosion pipe adhesive includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain the 3PE anti-corrosion pipe adhesive; the temperatures of each section of the twin-screw extruder are: 170℃ for the feeding section, 190℃ for the compression section, 210℃ for the homogenization section, and 220℃ for the die head, with a screw speed of 250 r / min; the cooling water temperature for the water-cooled pelletizing is 30℃, and the pelletizing speed is 300 r / min.

[0040] Comparative Example 1 An adhesive for 3PE anti-corrosion pipes and its preparation method are basically the same as those in Example 1, except that an equal amount of MBS resin is used instead of hydroxyl-terminated hyperbranched polyurethane.

[0041] Comparative Example 2 A 3PE anti-corrosion pipe adhesive and its preparation method are basically the same as those in Example 1, except that an equal amount of terminal hydroxyl hyperbranched polyurethane is used instead of MBS resin.

[0042] To further illustrate the beneficial technical effects of the various embodiments of the present invention, relevant performance tests were conducted on each product according to current Chinese national standards or conventional methods. The test methods are as follows: (1) Peel strength test: Referring to the national standard GB / T23257-2017, the adhesives prepared in Example 1 and Comparative Examples 1-2 were coated between the epoxy coating and the polyethylene layer to prepare 3PE anti-corrosion coating samples. The peel strength was tested at room temperature (25℃) and high temperature (120℃) respectively. Each sample was tested 3 times and the average value was taken.

[0043] (2) Temperature resistance test: The sample was placed in a constant temperature oven at 120℃ for 1000h, and then cooled to room temperature. The peel strength retention rate was tested (retention rate = peel strength after high temperature / initial peel strength × 100%).

[0044] (3) Salt spray corrosion test: Refer to the national standard GB / T 1771-2007 "Determination of the resistance of paints and varnishes to neutral salt spray", place the sample in the salt spray test chamber, set the salt spray concentration to 5% (NaCl solution), the temperature to 35℃, spray continuously, observe whether the sample coating shows blistering, peeling and other phenomena, and record the time when corrosion defects appear.

[0045] Table 1 Performance Test Results Group Example 1 Comparative Example 1 Comparative Example 2 Room temperature peel strength (N / cm) 206 155 167 Peel strength at 120℃ (N / cm) 173 108 113 Peel strength retention rate (%) after 1000 hours of constant temperature at 120℃ 89.8 72.7 76.3 Salt spray corrosion resistance time (h) 3200 2100 2210 As shown in Table 1, the performance test results indicate that the 3PE anti-corrosion pipe adhesive of Example 1 is significantly superior to Comparative Example 1 (without hydroxyl-terminated hyperbranched polyurethane) and Comparative Example 2 (without MBS resin) in all performance indicators. Specifically, Example 1 has a room temperature peel strength of 206 N / cm, a 120°C peel strength of 193 N / cm, a peel strength retention rate of 89.8% after 1000 hours at 120°C, and a salt spray corrosion resistance time of up to 3200 hours, all of which are much higher than the two control groups. This fully demonstrates that the synergistic effect of hydroxyl-terminated hyperbranched polyurethane and MBS resin can effectively improve the interfacial bonding force, high temperature stability, and salt spray corrosion resistance of the adhesive.

[0046] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A 3PE anti-corrosion pipe adhesive, characterized in that, It is made from the following raw materials in parts by weight: 60-80 parts of matrix resin, 10-15 parts of tackifier, 5-8 parts of hydroxyl-terminated hyperbranched polyurethane, 5-10 parts of MBS resin, 2-5 parts of nano-hybrid filler, 0.5-0.8 parts of coupling agent, 0.5-1.5 parts of antioxidant, 1-3 parts of processing aid, and 3-6 parts of polarity modifier.

2. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The matrix resin is maleic anhydride-grafted polyethylene 900E.

3. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The tackifier is a mixture of C5 hydrogenated petroleum resin CH-100 and terpene resin T-100 in a mass ratio of (3-5):

1.

4. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The hydroxyl-terminated hyperbranched polyurethane is grade 2499 and catalog number HXKJ2025; the MBS resin is DENKA TH-21 MBS resin.

5. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The nano-hybrid filler is nano-silica, and the average particle size of the nano-hybrid filler is 20-60 nm; the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

6. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The processing aid is a compound of calcium stearate and polyethylene wax in a mass ratio of 1:(0.8-1.2).

7. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The polarity modifier is an ethylene-vinyl acetate copolymer.

8. The 3PE anti-corrosion pipe adhesive according to claim 1, characterized in that, The ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer EVA1828.

9. A method for preparing a 3PE anti-corrosion pipe adhesive according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture; feeding the mixture into a twin-screw extruder for melt blending and extrusion to obtain a molten material; subsequently, extruding the molten material through a die and granulating it using a water-cooled pelletizing method to obtain a 3PE anti-corrosion pipe adhesive.

10. The method for preparing the 3PE anti-corrosion pipe adhesive according to claim 9, characterized in that, The temperatures of each section of the twin-screw extruder are as follows: feeding section 150-170℃, compression section 170-190℃, homogenization section 190-210℃, die head 200-220℃, and screw speed 150-250 r / min; the cooling water temperature of the water-cooled pelletizer is 20-30℃, and the pelletizing speed is 200-300 r / min.