Adhesive for corrosion prevention of 3PP pipeline

Abstract

The invention discloses an adhesive for corrosion prevention of a 3PP pipeline and a preparation method of the adhesive, and relates to the technical field of pipeline corrosion prevention. The adhesive comprises the following raw materials: compound matrix resin (hyperbranched polyethylene and maleic anhydride grafted modified polypropylene), an ethylene-glycidyl methacrylate copolymer, a nano hybrid filler and the like, and all the components have a synergistic effect to improve the performance. The preparation method comprises the following steps: mixing the raw materials except the curing agent, performing twin-screw melt blending extrusion on the mixture and the curing agent, granulating and the like. The adhesive disclosed by the invention has excellent room-temperature and high-temperature peel strength, temperature resistance and salt spray corrosion resistance, meets the anticorrosion requirements of 3PP pipelines, and is simple and controllable in preparation process and high in practicability.

Description

Technical Field

[0001] This invention relates to the field of pipeline corrosion protection materials, and in particular to a 3PP pipeline corrosion protection adhesive. Background Technology

[0002] The three-layer polyolefin (3PP) anti-corrosion structure is one of the mainstream anti-corrosion coating systems for long-distance oil and gas pipelines both domestically and internationally. Its structure, from the inside out, consists of: a fusion-bonded epoxy powder underlayer, an adhesive intermediate layer, and a polypropylene outer protective layer. This system, due to its superior high-temperature resistance, acid and alkali resistance, and water vapor permeability resistance compared to 3PE, has become the preferred choice for long-distance pipelines in high-temperature and high-UV regions such as deserts and Gobi. Among these, the adhesive, as the core intermediate layer of the 3PP coating system, plays a crucial role in connecting the underlayer epoxy powder coating to the outer polypropylene jacket layer. Its bonding strength, temperature resistance, and corrosion resistance directly affect the reliability of the entire anti-corrosion system.

[0003] Currently, most common 3PP pipe corrosion protection adhesives use maleic anhydride-grafted modified polyolefins (such as MAH-g-PP) as the main resin. While these adhesives improve polar compatibility with epoxy powder to some extent, they still have some shortcomings: First, the bond strength decreases significantly at higher temperatures (e.g., above 70℃) or under long-term hot water immersion conditions, especially in shear strength. Second, some adhesives have a narrow melt viscosity window, which can easily lead to sagging or insufficient wetting during pipe spraying and wrapping processes, affecting the uniformity of coating quality. Third, they have stringent requirements for substrate surface treatment; even slight differences in the surface condition of the epoxy powder can cause significant fluctuations in bonding reliability. Other 3PP pipe corrosion protection adhesives on the market also suffer from poor component compatibility, leading to interlayer delamination, blistering, and other failures during long-term service. Furthermore, they lack sufficient resistance to chemical corrosion, resulting in a significantly shortened service life in corrosive environments such as sulfur-containing crude oil and brine.

[0004] To solve the above-mentioned technical problems, invention patent CN104497958B discloses an adhesive for 3PP pipe corrosion protection, wherein the weight percentage of each raw material component is as follows: Nylon 1010 20-40%; polycarbonate 10-20%; compatibilizer A 3-8%; compatibilizer B 20-30%; bonding resin 10-20%; toughening resin 10-20%. The melt index of the nylon 1010 is 3.0–20.0 g / 10 min; the melt index of the polycarbonate is 3.0–20.0 g / 10 min; the compatibilizer A is a styrene-maleic anhydride copolymer; the bonding resin is an ethylene-acrylic acid copolymer; the toughening resin is one or a mixture of POE-g-MAH and / or SEBS-g-MAH. This invention, as a bonding resin in a 3PP system, maintains high bonding strength even at temperatures exceeding 100°C, ensuring the performance of the 3PP coating at high temperatures and playing a crucial role in the stability of the entire 3PP anti-corrosion system. However, the use of a high proportion of nylon 1010 and polycarbonate leads to a significant increase in raw material costs.

[0005] Therefore, developing a 3PP pipe corrosion-resistant adhesive that combines excellent high-temperature performance, strong corrosion resistance, reliable adhesion, and stable preparation process has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a 3PP pipe corrosion-resistant adhesive. By optimizing the component design and preparation process, it achieves a synergistic improvement in high-temperature stability and corrosion resistance, while reducing production costs, improving the stability of industrial production, and meeting the application requirements of various harsh working conditions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an adhesive for 3PP pipe corrosion protection, comprising, by weight percentage: 60-80 parts of matrix resin, 5-8 parts of ethylene-glycidyl methacrylate copolymer, 3-5 parts of nano-hybrid filler, 3-5 parts of functional additives, 4-6 parts of hydrogenated petroleum resin, 0.1-0.3 parts of β-nucleating agent, and 0.5-1 parts of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:(0.8-1.2).

[0008] Preferably, the hyperbranched polyethylene is prepared according to the method of Example 1 in Chinese Patent CN116948068B.

[0009] Preferably, the maleic anhydride-grafted modified polypropylene has a grafting rate of 0.8-1.5 wt% and a melt index of 30-80 g / 10 min.

[0010] Preferably, the ethylene-glycidyl methacrylate copolymer is of type LOTADER® AX8840.

[0011] Preferably, the nano-hybrid filler is composed of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of (3-5):1.

[0012] Preferably, the average particle size of the nano-titanium dioxide is 10-70 nm.

[0013] Preferably, the functional additive is a compound of coupling agent, antioxidant, lubricant and ultraviolet absorber in a mass ratio of 1:(0.8-1.2):0.5:(0.3-0.6).

[0014] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0015] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0016] Preferably, the lubricant is at least one of zinc stearate and ethylene bis-stearamide.

[0017] Preferably, the ultraviolet absorber is ultraviolet absorber UV-531.

[0018] Preferably, the hydrogenated petroleum resin is a C9 hydrogenated petroleum resin.

[0019] Preferably, the β-nucleating agent is β-nucleating agent NJS-1.

[0020] Preferably, the curing agent is dicyandiamide.

[0021] Another objective of this invention is to provide a method for preparing the 3PP pipe anti-corrosion adhesive, comprising the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and the curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying and packaging to obtain the 3PP pipe anti-corrosion adhesive.

[0022] Preferably, the process parameters of the twin-screw extruder are: feeding section temperature 160-170℃, compression section temperature 180-190℃, melting section temperature 200-210℃, die head temperature 190-200℃, screw speed 350-400 r / min, and length-to-diameter ratio 38:1.

[0023] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The 3PP pipe anti-corrosion adhesive disclosed in this invention, through the precise compounding of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene, combined with the regulation of resin crystallization morphology by β-nucleating agent and the reinforcing and toughening effect of nano-hybrid filler, not only improves the shear bond strength retention rate of the adhesive at high temperature without introducing high-cost crystalline polar resin, but also does not exhibit interlaminar cracking in low-temperature impact tests. For the first time, it has achieved full coverage of harsh working conditions in high-temperature and high-UV regions and cold regions. Its synergistic improvement effect on high and low temperature performance far exceeds the expectations of existing technologies.

[0024] (2) The 3PP pipe anti-corrosion adhesive disclosed in this invention provides more active bonding sites through the branched structure of hyperbranched polyethylene. Combined with the reactive bonding effect of ethylene-glycidyl methacrylate copolymer, it significantly reduces the sensitivity to substrate surface treatment. At the same time, the addition of hydrogenated petroleum resin precisely adjusts the melt viscosity of the adhesive. Combined with the parameter optimization of the twin-screw extrusion process, the melt viscosity window is widened. It can not only adapt to the parameters of spraying and winding equipment of different manufacturers, but also form a uniform, non-sagging, and fully wetted intermediate layer on the pipe surface. Even when the surface roughness of epoxy powder is deviated, the fluctuation range of bonding strength is still controllable. Its adaptability to construction process and the stability of bonding reliability far exceed the existing technology.

[0025] (3) The 3PP pipe corrosion protection adhesive disclosed in this invention, through the layered barrier effect and interface modification of nano-hybrid filler (DK2 nano organic clay and nano titanium dioxide), combined with the matrix resin compound system, constructs a dense corrosion-resistant barrier, making the corrosion resistance of the adhesive significantly better than that of traditional MAH-g-PP based adhesives; at the same time, this invention abandons the high-cost nylon 1010 and polycarbonate, and adopts hyperbranched polyethylene and MAH-g-PP compound matrix resin, achieving the dual goals of "high performance and low cost", and its technical effect and cost balance far exceed the conventional expectations of the industry.

[0026] (4) The 3PP pipe corrosion-resistant adhesive disclosed in this invention provides sufficient compatibility sites for each component through the branched structure of hyperbranched polyethylene. Combined with ethylene-glycidyl methacrylate copolymer as a reactive compatibilizer and surface modification of the nano-hybrid filler by a coupling agent, it achieves high compatibility among all components, including the matrix resin, functional additives, and nano-fillers. Through the synergistic effect of each raw material component, the long-term service stability of the 3PP corrosion-resistant system is significantly improved, with effects far exceeding those of existing technologies. Detailed Implementation

[0027] 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.

[0028] Example 1 An adhesive for 3PP pipe corrosion protection, by weight percentage, comprises the following raw material components: 60 parts of matrix resin, 5 parts of ethylene-glycidyl methacrylate copolymer, 3 parts of nano-hybrid filler, 3 parts of functional additives, 4 parts of hydrogenated petroleum resin, 0.1 parts of β-nucleating agent, and 0.5 parts of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:0.8.

[0029] The hyperbranched polyethylene was prepared according to the method of Example 1 in invention patent CN116948068B; the maleic anhydride grafted modified polypropylene had a grafting rate of 0.8 wt% and a melt index of 30 g / 10 min; the ethylene-glycidyl methacrylate copolymer was model LOTADER® AX8840; the nano-hybrid filler was a mixture of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of 3:1; the average particle size of the nano-titanium dioxide was... The wavelength is 10 nm; the functional additives are a mixture of coupling agent, antioxidant, lubricant, and ultraviolet absorber in a mass ratio of 1:0.8:0.5:0.3; the coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the lubricant is zinc stearate; the ultraviolet absorber is ultraviolet absorber UV-531; the hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

[0030] A method for preparing the 3PP pipe anti-corrosion adhesive includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying, and packaging to obtain the 3PP pipe anti-corrosion adhesive; the process parameters of the twin-screw extruder are: feeding section temperature 160℃, compression section temperature 180℃, melting section temperature 200℃, die head temperature 190℃, screw speed 350r / min, and length-to-diameter ratio 38:1.

[0031] Example 2 A 3PP pipe corrosion-resistant adhesive, by weight percentage, comprises the following raw material components: 65 parts of matrix resin, 6 parts of ethylene-glycidyl methacrylate copolymer, 3.5 parts of nano-hybrid filler, 3.5 parts of functional additives, 4.5 parts of hydrogenated petroleum resin, 0.15 parts of β-nucleating agent, and 0.6 parts of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:0.9.

[0032] The hyperbranched polyethylene was prepared according to the method in Example 1 of the invention patent CN116948068B; the maleic anhydride grafted modified polypropylene had a grafting rate of 1 wt% and a melt index of 50 g / 10 min; the ethylene-glycidyl methacrylate copolymer was model LOTADER® AX8840; the nano-hybrid filler was a mixture of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of 3.5:1; the average particle size of the nano-titanium dioxide was [missing information]. 30nm; the functional additives are a mixture of coupling agent, antioxidant, lubricant, and ultraviolet absorber in a mass ratio of 1:0.9:0.5:0.4; the coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 168; the lubricant is ethylene bis-stearamide; the ultraviolet absorber is ultraviolet absorber UV-531; the hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

[0033] A method for preparing the 3PP pipe anti-corrosion adhesive includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying, and packaging to obtain the 3PP pipe anti-corrosion adhesive; the process parameters of the twin-screw extruder are: feeding section temperature 163℃, compression section temperature 183℃, melting section temperature 202℃, die head temperature 193℃, screw speed 360r / min, and length-to-diameter ratio 38:1.

[0034] Example 3 A 3PP pipe corrosion protection adhesive, by weight percentage, comprises the following raw material components: 70 parts of matrix resin, 6.5 parts of ethylene-glycidyl methacrylate copolymer, 4 parts of nano-hybrid filler, 4 parts of functional additives, 5 parts of hydrogenated petroleum resin, 0.2 parts of β-nucleating agent, and 0.7 parts of curing agent; wherein the matrix resin is a mixture of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:1.

[0035] The hyperbranched polyethylene was prepared according to the method of Example 1 in invention patent CN116948068B; the maleic anhydride grafted modified polypropylene had a grafting rate of 1.1 wt% and a melt index of 55 g / 10 min; the ethylene-glycidyl methacrylate copolymer was model LOTADER® AX8840; the nano-hybrid filler was a mixture of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of 4:1; the average particle size of the nano-titanium dioxide was... The diameter is 40 nm; the functional additives are a mixture of coupling agent, antioxidant, lubricant, and ultraviolet absorber in a mass ratio of 1:1:0.5:0.45; the coupling agent is silane coupling agent KH570; the antioxidant is antioxidant 1010; the lubricant is zinc stearate; the ultraviolet absorber is ultraviolet absorber UV-531; the hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

[0036] A method for preparing the 3PP pipe anti-corrosion adhesive includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying, and packaging to obtain the 3PP pipe anti-corrosion adhesive; the process parameters of the twin-screw extruder are: feeding section temperature 165℃, compression section temperature 185℃, melting section temperature 205℃, die head temperature 195℃, screw speed 380r / min, and length-to-diameter ratio 38:1.

[0037] Example 4 A 3PP pipe corrosion-resistant adhesive, by weight percentage, comprises the following raw material components: 75 parts of matrix resin, 7.5 parts of ethylene-glycidyl methacrylate copolymer, 4.5 parts of nano-hybrid filler, 4.5 parts of functional additives, 5.5 parts of hydrogenated petroleum resin, 0.25 parts of β-nucleating agent, and 0.9 parts of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:1.1.

[0038] The hyperbranched polyethylene was prepared according to the method of Example 1 in invention patent CN116948068B; the maleic anhydride grafted modified polypropylene had a grafting rate of 1.4 wt% and a melt index of 70 g / 10 min; the ethylene-glycidyl methacrylate copolymer was model LOTADER® AX8840; the nano-hybrid filler was a mixture of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of 4.5:1; the average particle size of the nano-titanium dioxide was 60 nm; the functional additives were coupling agents, antioxidants, lubricants, and ultraviolet absorbers in a mass ratio of The mixture is composed of a compound in a ratio of 1:1.1:0.5:0.55; the coupling agent is composed 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 composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 3:5; the lubricant is composed of zinc stearate and ethylene bis-stearamide in a mass ratio of 1:2; the ultraviolet absorber is ultraviolet absorber UV-531; the hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

[0039] A method for preparing the 3PP pipe anti-corrosion adhesive includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying, and packaging to obtain the 3PP pipe anti-corrosion adhesive; the process parameters of the twin-screw extruder are: feeding section temperature 168℃, compression section temperature 188℃, melting section temperature 208℃, die head temperature 198℃, screw speed 390r / min, and length-to-diameter ratio 38:1.

[0040] Example 5 A 3PP pipe corrosion protection adhesive, by weight percentage, comprises the following raw material components: 80 parts of matrix resin, 8 parts of ethylene-glycidyl methacrylate copolymer, 5 parts of nano-hybrid filler, 5 parts of functional additives, 6 parts of hydrogenated petroleum resin, 0.3 parts of β-nucleating agent, and 1 part of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:1.2.

[0041] The hyperbranched polyethylene was prepared according to the method of Example 1 in invention patent CN116948068B; the maleic anhydride grafted modified polypropylene had a grafting rate of 1.5 wt% and a melt index of 80 g / 10 min; the ethylene-glycidyl methacrylate copolymer was model LOTADER® AX8840; the nano-hybrid filler was a mixture of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of 5:1; the average particle size of the nano-titanium dioxide was... The wavelength is 70 nm; the functional additives are a mixture of coupling agent, antioxidant, lubricant, and ultraviolet absorber in a mass ratio of 1:1.2:0.5:0.6; the coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 1010; the lubricant is zinc stearate; the ultraviolet absorber is ultraviolet absorber UV-531; the hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

[0042] A method for preparing the 3PP pipe anti-corrosion adhesive includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially performing extrusion granulation, drying, and packaging to obtain the 3PP pipe anti-corrosion adhesive; the process parameters of the twin-screw extruder are: feeding section temperature 170℃, compression section temperature 190℃, melting section temperature 210℃, die head temperature 200℃, screw speed 400r / min, and length-to-diameter ratio 38:1.

[0043] Comparative Example 1 An adhesive for 3PP pipe corrosion protection is basically the same as that in Example 5, except that an equal amount of maleic anhydride-grafted modified polypropylene is used instead of hyperbranched polyethylene.

[0044] Comparative Example 2 An adhesive for 3PP pipe corrosion protection is basically the same as that in Example 5, except that it does not contain ethylene-glycidyl methacrylate copolymer.

[0045] Comparative Example 3 An adhesive for 3PP pipe corrosion protection is basically the same as that in Example 5, except that no β-nucleating agent and curing agent are added.

[0046] To further illustrate the beneficial technical effects of the various embodiments of the present invention, relevant performance tests were conducted on Example 5 and Comparative Examples 1-3. The test results are shown in Table 1. The test methods are as follows: The adhesives prepared in Example 5 and Comparative Examples 1-3 were molded into 0.2 mm thick films by hot pressing at 230°C and 0.5 MPa pressure. (1) Peel strength test: Refer to GB / T 2790-1995 "Test method for peel strength of adhesives at 180°, flexible materials vs. rigid materials", place the adhesive film between an epoxy powder steel plate (surface sandblasted) and a polypropylene plate and hot press to form a standard sample for testing. The peel strength is tested at room temperature (25°C) and high temperature (120°C) respectively. Each sample is tested 3 times and the average value is taken.

[0047] (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%).

[0048] (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.

[0049] Table 1 Performance Test Results Group Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Room temperature peel strength (N / cm) 210 156 128 95 Peel strength at 120℃ (N / cm) 180 112 85 52 Peel strength retention rate (%) after 1000 hours of constant temperature at 120℃ 93.8 78.5 62.3 45.6 Salt spray corrosion resistance time (h) 3325 2450 1880 1260 Table 1 shows the performance test results, indicating that Example 5 (containing all components including hyperbranched polyethylene and maleic anhydride grafted modified polypropylene matrix, ethylene-glycidyl methacrylate copolymer, etc.) exhibits the best peel strength at room temperature and 120°C, peel strength retention rate at 120°C for 1000 hours, and salt spray corrosion resistance time. In contrast, the properties of Comparative Example 1 (replacing hyperbranched polyethylene), Comparative Example 2 (lacking ethylene-glycidyl methacrylate copolymer), and Comparative Example 3 (lacking β-nucleating agent and curing agent) decreased significantly in that order, confirming the synergistic necessity of the key components and compound system of this invention in improving the adhesive's bonding performance, temperature resistance, and corrosion resistance.

[0050] 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. An adhesive for corrosion protection of 3PP pipes, characterized in that, By weight percentage, its raw material components include: 60-80 parts of matrix resin, 5-8 parts of ethylene-glycidyl methacrylate copolymer, 3-5 parts of nano-hybrid filler, 3-5 parts of functional additives, 4-6 parts of hydrogenated petroleum resin, 0.1-0.3 parts of β-nucleating agent, and 0.5-1 parts of curing agent; wherein the matrix resin is a compound of hyperbranched polyethylene and maleic anhydride grafted modified polypropylene in a mass ratio of 1:(0.8-1.2).

2. The 3PP pipe corrosion protection adhesive according to claim 1, characterized in that, The maleic anhydride-grafted modified polypropylene has a grafting rate of 0.8-1.5 wt% and a melt index of 30-80 g / 10 min.

3. The 3PP pipe corrosion protection adhesive according to claim 1, characterized in that, The ethylene-glycidyl methacrylate copolymer is designated as LOTADER® AX8840.

4. The 3PP pipe corrosion protection adhesive according to claim 1, characterized in that, The nano-hybrid filler is composed of DK2 nano-organic clay and nano-titanium dioxide in a mass ratio of (3-5):1; the average particle size of the nano-titanium dioxide is 10-70 nm.

5. The 3PP pipe corrosion protection adhesive according to claim 1, characterized in that, The functional additives are a mixture of coupling agents, antioxidants, lubricants, and ultraviolet absorbers in a mass ratio of 1:(0.8-1.2):0.5:(0.3-0.6).

6. The 3PP pipe corrosion protection adhesive according to claim 5, characterized in that, 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.

7. The 3PP pipe corrosion protection adhesive according to claim 5, characterized in that, The lubricant is at least one of zinc stearate and ethylene bis-stearamide; the ultraviolet absorber is ultraviolet absorber UV-531.

8. The 3PP pipe corrosion protection adhesive according to claim 1, characterized in that, The hydrogenated petroleum resin is C9 hydrogenated petroleum resin; the β-nucleating agent is β-nucleating agent NJS-1; and the curing agent is dicyandiamide.

9. A method for preparing the 3PP pipe corrosion-resistant adhesive according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing all raw material components except the curing agent evenly to obtain a mixture; adding the mixture and curing agent to a twin-screw extruder for melt blending and extrusion; and then sequentially extruding, granulating, drying, and packaging to obtain 3PP pipe anti-corrosion adhesive.

10. The method for preparing the 3PP pipe anti-corrosion adhesive according to claim 9, characterized in that, The process parameters of the twin-screw extruder are as follows: feeding section temperature 160-170℃, compression section temperature 180-190℃, melting section temperature 200-210℃, die head temperature 190-200℃, screw speed 350-400 r / min, and length-to-diameter ratio 38:1.