High-crack-resistance and high-durability medium-pressure polyethylene pipeline material and preparation method thereof

Abstract

The invention is suitable for the technical field of polyethylene pipeline materials, and provides a high-crack-resistance and high-durability medium-pressure polyethylene pipeline material and a preparation method thereof. Comprising the following components in parts by weight: 100 to 140 parts of medium-pressure polyethylene, 5 to 7 parts of tetra (octadecyloxy) phthalocyanine, 0.6 to 1.2 parts of a nucleating agent, 2 to 4 parts of nano silicon dioxide, 1.5 to 4.5 parts of montmorillonite, 1.3 to 2.7 parts of carbon black, 0.7 to 1.4 parts of a surfactant and 1.1 to 2.6 parts of a toughening agent. Preferably, the preparation method of the tetra (octadecyloxy) phthalocyanine comprises the following steps: adding tetrachloro phthalocyanine and octadecanol into a container according to a molar ratio of 1: 4, then adding a proper amount of K2CO3, taking DMF (Dimethyl Formamide) as a solvent, reacting under the protection of nitrogen, after the reaction is finished, adding ice water, filtering, and recrystallizing with methanol. The crack resistance and durability of the polyethylene pipeline material are remarkably improved, in addition, the preparation method is simple and easy to implement and easy for industrial production, and the prepared medium-pressure polyethylene pipeline material is low in cost and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of polyethylene pipe materials, in particular to a medium-pressure polyethylene pipe material with high crack resistance and high durability and a preparation method thereof. Background Art

[0002] Polyethylene pipe material is a commonly used plastic pipe material, widely used in municipal engineering, industrial pipelines, agricultural irrigation and other fields. Its main advantages include corrosion resistance, strong chemical resistance, and easy installation. Due to its excellent performance, polyethylene pipe material is increasingly used in the gas field, especially in urban natural gas transmission, gas facilities and pipeline system construction, such as:

[0003] Chinese patent application number CN201610224181.5 and publication number CN105670086A discloses a polyethylene gas pipe material made from the following components by weight: 100-110 parts high-density polyethylene, 18-24 parts nitrile rubber, 5-12 parts trisnonylphenyl phosphite, 3-5 parts oleamide, 2-4 parts alkylphenol polyoxyethylene ether, 2-6 parts silica, 2-6 parts diphenyl octyl phosphite, 3-5 parts polyethylene wax, 5-9 parts acrylate copolymer, 3-5 parts sodium lauryl sulfate, and 6-8 parts alkoxy polydimethylsiloxane. The polyethylene gas pipe material provided by this invention exhibits excellent flame retardancy, compression resistance, flexibility, low- and high-temperature resistance, and strong rapid crack growth fracture toughness.

[0004] Chinese patent application number CN202411571769.9 and publication number CN119081270A discloses a high-strength, wear-resistant polyethylene gas pipeline and its preparation method. This invention, belonging to the field of polymer materials technology, utilizes high-density polyethylene, modified EPDM rubber, modified chlorinated polyethylene rubber, modified basalt fiber, silicon carbide ceramic, magnesium oxide, lubricant, hindered amine light stabilizer, hindered phenol antioxidant, and antistatic agent as raw materials. The invention also designs the mixing, mixing, and extrusion process steps and parameters based on the properties and dispersion characteristics of each component material. This allows for the production of uniform, high-performance gas pipelines. The invention significantly improves the pipeline's compressive strength, impact resistance, and wear resistance, as well as its weather resistance. This improves the pipeline's overall performance and service life, making it more suitable for use in various harsh environments. It can meet the demands of long-distance construction, long-term friction, and high-pressure environments, and is widely applicable to high-, medium-, and low-pressure gas transportation, as well as civil and industrial gas transportation.

[0005] In the gas industry, the crack resistance and durability of polyethylene pipe materials are crucial, as they impact the safety, stability, and long-term reliability of gas systems. During use, gas pipelines may be affected by various external loads, temperature fluctuations, soil movement, and other factors. Pipeline materials with poor crack resistance can lead to the risk of gas leaks. Durability, on the other hand, is crucial to the service life of polyethylene pipe materials. Polyethylene pipe materials with poor durability can lead to frequent replacements during use, impacting performance and increasing costs.

[0006] While existing polyethylene pipe materials have seen improvements in flame retardancy, pressure resistance, and flexibility, they still need further improvement in terms of crack resistance and durability. Especially in complex and changing external environments, such as extreme temperatures and fluctuating soil pressure, existing polyethylene pipe materials often fail to meet the requirements for long-term safe use. Therefore, developing a polyethylene pipe material with even higher crack resistance and durability is crucial. Summary of the Invention

[0007] The purpose of the present invention is to provide a medium-pressure polyethylene pipe material with high crack resistance and high durability and a preparation method thereof, so as to solve the problem that the crack resistance and durability of polyethylene pipe materials in the prior art still need to be further improved.

[0008] To achieve the above objectives, the present invention provides the following technical solutions: In a first aspect, the present invention provides a medium-pressure polyethylene pipe material with high crack resistance and high durability, comprising the following components and weight proportions:

[0009] 100-140 parts of medium-pressure polyethylene, 5-7 parts of tetrakis(octadecyloxy)phthalocyanine, 0.6-1.2 parts of nucleating agent, 2-4 parts of nano-silica, 1.5-4.5 parts of montmorillonite, 1.3-2.7 parts of carbon black, 0.7-1.4 parts of surfactant, and 1.1-2.6 parts of toughening agent.

[0010] Preferably, the preparation method of the tetrakis(octadecyloxy)phthalocyanine is as follows:

[0011] Tetrachlorophthalocyanine and octadecyl alcohol were added to a container in a molar ratio of 1:4, and then an appropriate amount of K2CO3 was added. DMF was used as a solvent and the reaction was carried out under nitrogen protection. After the reaction was completed, ice water was added, the mixture was filtered, and the mixture was recrystallized with methanol.

[0012] Preferably, the reaction temperature of the tetrakis(octadecyloxy)phthalocyanine preparation method is 120° C., and the reaction time is 24-36 hours.

[0013] Preferably, the nucleating agent is one or more of dibenzylidene sorbitol, di(p-methylbenzylidene)sorbitol, and di(3,4-dimethylbenzylidene)sorbitol.

[0014] Preferably, the surfactant is one or more of calcium stearate, oleamide, and polyethylene wax.

[0015] Preferably, the toughening agent is one or more of POE elastomer, SEBS-g-MAH, and methyl methacrylate-butadiene-styrene.

[0016] Preferably, the weight ratio of the medium-pressure polyethylene to tetrakis(octadecyloxy)phthalocyanine is 20:1.

[0017] Preferably, the medium-pressure polyethylene pipe material further comprises 0.3-0.7 parts by weight of an antioxidant, 0.1-0.6 parts by weight of a flame retardant, and 0.2-0.4 parts by weight of a light stabilizer.

[0018] Preferably, the antioxidant is one of Irganox 1010 and Irgafos 168; the flame retardant is one of magnesium hydroxide and aluminum hydroxide; and the light stabilizer is one of Tinuvin 326 and UV-531.

[0019] The second aspect of the present invention provides a method for preparing the medium-pressure polyethylene pipe material according to the first aspect of the present invention, comprising the following steps:

[0020] S1, prepare tetrakis(octadecyloxy)phthalocyanine, and dry it with other powder raw materials at 40-60°C for 4-8h;

[0021] S2, adding all raw materials into a high-speed blender, pre-mixing, and stirring for 10-30 minutes;

[0022] S3, adding the pre-mixed mixture into a twin-screw extruder for melt blending and extrusion. The temperature of each section of the twin-screw extruder is set as follows:

[0023] Feeding section: 140-160℃;

[0024] Melting / compression section: 170-190°C;

[0025] Mixing section: 180-200℃;

[0026] Homogenization / metering section: 180-190°C;

[0027] Die head / die head: 170-180℃;

[0028] S4, the melt-blended material is extruded into strips through a die, cooled in a water tank, and cut into uniform pellets by a pelletizer. The cut pellets are sent to a fluidized bed dryer or oven, fully dried at 80-90°C for 3-5 hours, and then extruded into a tube using a single-screw extruder.

[0029] The present invention has at least the following beneficial effects:

[0030] The present invention provides a highly crack-resistant and durable medium-pressure polyethylene pipe material and a preparation method, which significantly improves the crack resistance and durability of the polyethylene pipe material. In addition, the preparation method of the present invention is simple and easy to implement, and is easy to industrialize. The prepared medium-pressure polyethylene pipe material is low in cost and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a reaction scheme of tetrakis(octadecyloxy)phthalocyanine of the present invention. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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.

[0033] Example 1

[0034] This embodiment provides a medium-pressure polyethylene pipe material with high crack resistance and high durability, including the following components and parts by weight:

[0035] 100 parts of medium-pressure polyethylene, 5 parts of tetrakis(octadecyloxy)phthalocyanine, 0.6 parts of nucleating agent, 2 parts of nano-silica, 1.5 parts of montmorillonite, 1.3 parts of carbon black, 0.7 parts of surfactant, and 1.1 parts of toughening agent.

[0036] Among them, the nucleating agent is dibenzylidene sorbitol; the surfactant is calcium stearate; and the toughening agent is POE elastomer.

[0037] The weight ratio of the medium-pressure polyethylene to tetra(octadecyloxy)phthalocyanine is 20:1.

[0038] The method for preparing the above medium-pressure polyethylene pipe material comprises the following steps:

[0039] S1, tetrachlorophthalocyanine and octadecyl alcohol were added to a container in a molar ratio of 1:4, and then an appropriate amount of K2CO3 was added. DMF was used as a solvent and the reaction was carried out at 120°C for 24 hours under nitrogen protection. After the reaction was completed, ice water was added, the mixture was filtered, and the mixture was recrystallized with methanol to prepare tetrakis(octadecyloxy)phthalocyanine (such as Figure 1 As shown), and dried it with other powder raw materials at 40 ° C for 8 hours;

[0040] S2, adding all raw materials into a high-speed blender, pre-mixing, and stirring for 10 minutes;

[0041] S3, adding the pre-mixed mixture into a twin-screw extruder for melt blending and extrusion. The temperature of each section of the twin-screw extruder is set as follows:

[0042] Feeding section: 140℃;

[0043] Melting / compression section: 170°C;

[0044] Mixing section: 180℃;

[0045] Homogenization / metering section: 180°C;

[0046] Die head / die head: 170℃;

[0047] S4, the melt-blended material is extruded into strips through a die, cooled in a water tank, and cut into uniform pellets by a pelletizer. The cut pellets are sent to a fluidized bed dryer or oven, fully dried at 80°C for 3 hours, and then extruded into a tube using a single-screw extruder.

[0048] Example 2

[0049] This embodiment provides a medium-pressure polyethylene pipe material with high crack resistance and high durability, including the following components and parts by weight:

[0050] 120 parts of medium-pressure polyethylene, 6 parts of tetrakis(octadecyloxy)phthalocyanine, 1 part of nucleating agent, 3 parts of nano-silica, 3.6 parts of montmorillonite, 2.1 parts of carbon black, 1.3 parts of surfactant, and 1.9 parts of toughening agent.

[0051] The nucleating agent is di(p-methylbenzylidene) sorbitol; the surfactant is oleamide; and the toughening agent is SEBS-g-MAH.

[0052] The weight ratio of the medium-pressure polyethylene to tetra(octadecyloxy)phthalocyanine is 20:1.

[0053] The method for preparing the above medium-pressure polyethylene pipe material comprises the following steps:

[0054] S1, tetrachlorophthalocyanine and octadecyl alcohol were added to a container in a molar ratio of 1:4, and then an appropriate amount of K2CO3 was added. DMF was used as a solvent and the reaction was carried out at 120°C for 32 hours under nitrogen protection. After the reaction was completed, ice water was added, the mixture was filtered, and the mixture was recrystallized with methanol to prepare tetrakis(octadecyloxy)phthalocyanine (such as Figure 1 As shown), and dried it with other powder raw materials at 50 ° C for 6 hours;

[0055] S2, adding all raw materials into a high-speed blender, pre-mixing, and stirring for 20 minutes;

[0056] S3, adding the pre-mixed mixture into a twin-screw extruder for melt blending and extrusion. The temperature of each section of the twin-screw extruder is set as follows:

[0057] Feeding section: 150℃;

[0058] Melting / compression section: 180°C;

[0059] Mixing section: 190℃;

[0060] Homogenization / metering section: 185°C;

[0061] Die head / die head: 175℃;

[0062] S4, the melt-blended material is extruded into strips through a die, cooled in a water tank, and cut into uniform pellets by a pelletizer. The cut pellets are sent to a fluidized bed dryer or oven, fully dried at 85°C for 4 hours, and then extruded into a tube using a single-screw extruder.

[0063] Example 3

[0064] This embodiment provides a medium-pressure polyethylene pipe material with high crack resistance and high durability, including the following components and parts by weight:

[0065] 140 parts of medium-pressure polyethylene, 7 parts of tetrakis(octadecyloxy)phthalocyanine, 1.2 parts of nucleating agent, 4 parts of nano-silica, 4.5 parts of montmorillonite, 2.7 parts of carbon black, 1.4 parts of surfactant, and 2.6 parts of toughening agent.

[0066] The nucleating agent is di(3,4-dimethylbenzylidene)sorbitol; the surfactant is polyethylene wax; and the toughening agent is methyl methacrylate-butadiene-styrene.

[0067] The weight ratio of the medium-pressure polyethylene to tetra(octadecyloxy)phthalocyanine is 20:1.

[0068] The method for preparing the above medium-pressure polyethylene pipe material comprises the following steps:

[0069] S1, tetrachlorophthalocyanine and octadecyl alcohol were added to a container in a molar ratio of 1:4, and then an appropriate amount of K2CO3 was added. DMF was used as a solvent and the reaction was carried out at 120°C for 36 hours under nitrogen protection. After the reaction was completed, ice water was added, the mixture was filtered, and the mixture was recrystallized with methanol to prepare tetrakis(octadecyloxy)phthalocyanine (such as Figure 1 As shown), and dried it with other powder raw materials at 60 ° C for 4 hours;

[0070] S2, adding all raw materials into a high-speed blender, pre-mixing, and stirring for 30 minutes;

[0071] S3, adding the pre-mixed mixture into a twin-screw extruder for melt blending and extrusion. The temperature of each section of the twin-screw extruder is set as follows:

[0072] Feeding section: 160℃;

[0073] Melting / compression section: 190°C;

[0074] Mixing section: 200℃;

[0075] Homogenization / metering section: 190°C;

[0076] Die head / die head: 180℃;

[0077] S4, the melt-blended material is extruded into strips through a die, cooled in a water tank, and cut into uniform pellets by a pelletizer. The cut pellets are sent to a fluidized bed dryer or oven, fully dried at 80-90°C for 3-5 hours, and then extruded into a tube using a single-screw extruder.

[0078] Example 4

[0079] This embodiment provides a medium-pressure polyethylene pipe material with high crack resistance and high durability. The material is the same as that of Example 1, except that it further comprises 0.3 parts by weight of an antioxidant, 0.1 parts by weight of a flame retardant, and 0.2 parts by weight of a light stabilizer; the antioxidant is Irganox 1010; the flame retardant is magnesium hydroxide; and the light stabilizer is Tinuvin 326.

[0080] Example 5

[0081] This embodiment provides a medium-pressure polyethylene pipe material with high crack resistance and high durability. It is the same as Example 3, except that it also includes 0.7 parts by weight of an antioxidant, 0.6 parts of a flame retardant, and 0.4 parts of a light stabilizer; the antioxidant is Irgafos168; the flame retardant is aluminum hydroxide; and the light stabilizer is UV-531.

[0082] The alkylated phthalocyanine produced by reacting tetrachlorophthalocyanine with octadecyl alcohol in the present invention induces the polyethylene to form smaller, more uniform spherulites. The small spherulites make the crack propagation path more tortuous, consuming more energy, thereby improving crack resistance. They also improve impact toughness, reduce the risk of brittle fracture, enhance tensile strength and rigidity, resist deformation cracking, accelerate the crystallization rate and increase the crystallization temperature, resulting in more uniform shrinkage of the product during processing and cooling, and also in the pipe during processing and cooling, reducing internal stress cracking caused by uneven shrinkage. Furthermore, tetrakis(octadecyloxy)phthalocyanine absorbs UV-A / UV-B radiation (particularly in the 300-400nm band), preventing photodegradation of the polyethylene chain; and imparts weak electrical conductivity to the pipe material, preventing electrostatic adsorption of dust.

[0083] The nucleating agent in the present invention can further effectively promote the crystallization of polyethylene, refine the grains, and improve the mechanical properties and thermal stability of the material. Nano-silica and montmorillonite, as inorganic nano-fillers, can significantly improve the rigidity and heat resistance of polyethylene, while enhancing the material's anti-aging properties. Carbon black not only gives the material a black color, but also has certain reinforcing and flame retardant effects. Surfactants can reduce the surface tension between the components and improve mixing uniformity. The addition of toughening agents can significantly improve the toughness of the material and reduce the risk of cracking caused by external forces during use. In addition, the addition of antioxidants, flame retardants and light stabilizers further improves the material's aging resistance and safety.

[0084] The performance comparison of the products obtained in Examples 1-5 above with the existing PE80 / PE100 pipe materials is shown in the following table:

[0085]

[0086] In summary, the product produced by this invention exhibits excellent crack resistance and durability, making it suitable for use in gas systems. This material not only meets the basic requirements for piping materials in municipal engineering, industrial piping, agricultural irrigation, and other fields, but also maintains long-term safe use in complex and changing external environments, providing a strong guarantee for the safety, stability, and long-term reliability of gas systems.

[0087] The above shows and describes the basic principles, main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and all variations that come within the meaning and range of equivalents of the claims are intended to be included therein.

[0088] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A medium-pressure polyethylene pipe material with high crack resistance and high durability, characterized in that: It includes the following ingredients and parts by weight: 100-140 parts of medium-pressure polyethylene, 5-7 parts of tetrakis(octadecyloxy)phthalocyanine, 0.6-1.2 parts of nucleating agent, 2-4 parts of nano-silica, 1.5-4.5 parts of montmorillonite, 1.3-2.7 parts of carbon black, 0.7-1.4 parts of surfactant, and 1.1-2.6 parts of toughening agent.

2. A medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The preparation method of the tetrakis(octadecyloxy)phthalocyanine is as follows: Tetrachlorophthalocyanine and octadecyl alcohol were added to a container in a molar ratio of 1:4, and then an appropriate amount of K2CO3 was added. DMF was used as a solvent and the reaction was carried out under nitrogen protection. After the reaction was completed, ice water was added, the mixture was filtered, and the mixture was recrystallized with methanol.

3. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 2, characterized in that: The reaction temperature of the tetrakis(octadecyloxy)phthalocyanine preparation method is 120° C., and the reaction time is 24-36 hours.

4. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The nucleating agent is one or more of dibenzylidene sorbitol, di(p-methylbenzylidene)sorbitol, and di(3,4-dimethylbenzylidene)sorbitol.

5. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The surfactant is one or more of calcium stearate, oleamide, and polyethylene wax.

6. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The toughening agent is one or more of POE elastomer, SEBS-g-MAH, and methyl methacrylate-butadiene-styrene.

7. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The weight ratio of the medium-pressure polyethylene to tetrakis(octadecyloxy)phthalocyanine is 20:

1.

8. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The medium-pressure polyethylene pipe material further comprises 0.3-0.7 parts by weight of an antioxidant, 0.1-0.6 parts by weight of a flame retardant, and 0.2-0.4 parts by weight of a light stabilizer.

9. The medium-pressure polyethylene pipe material with high crack resistance and high durability according to claim 1, characterized in that: The antioxidant is one of Irganox 1010 and Irgafos 168; the flame retardant is one of magnesium hydroxide and aluminum hydroxide; and the light stabilizer is one of Tinuvin 326 and UV-531.

10. A method for preparing the medium-pressure polyethylene pipe material according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, prepare tetrakis(octadecyloxy)phthalocyanine, and dry it with other powder raw materials at 40-60°C for 4-8h; S2, adding all raw materials into a high-speed blender, pre-mixing, and stirring for 10-30 minutes; S3, adding the pre-mixed mixture into a twin-screw extruder for melt blending and extrusion. The temperature of each section of the twin-screw extruder is set as follows: Feeding section: 140-160℃; Melting / compression section: 170-190°C; Mixing section: 180-200℃; Homogenization / metering section: 180-190°C; Die head / die head: 170-180℃; S4, the melt-blended material is extruded into strips through a die, cooled in a water tank, and cut into uniform pellets by a pelletizer. The cut pellets are sent to a fluidized bed dryer or oven, fully dried at 80-90°C for 3-5 hours, and then extruded into a tube using a single-screw extruder.

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