Toughened polyvinyl chloride electrical conduit and preparation method thereof

Abstract

The invention discloses a toughened polyvinyl chloride electrical conduit and a preparation method, and relates to the technical field of electrical conduits, and the toughened polyvinyl chloride electrical conduit is prepared from the following raw materials: polyvinyl chloride resin, a modified toughening agent, a stabilizer, a plasticizer, an inorganic flame retardant, a filler, a dispersant, a modified insect and mouse prevention agent and a cold-resistant agent. The modified toughening agent is prepared from phenolic resin, an elastomer, an antioxidant, a lubricant and a heat stabilizer, the weight percentage ratio of the phenolic resin to the elastomer to the antioxidant to the lubricant to the heat stabilizer is 100: (5-8): (1-3): (0.5-1.5): 2, the elastomer adopts ethylene propylene diene monomer, the antioxidant adopts 2, 6-di-tert-butyl-4-methylphenol, the lubricant adopts calcium stearate or zinc stearate, and the heat stabilizer adopts lead sulfate tribasic. By adopting the modified toughening agent, the electrical conduit has higher toughness and can bear larger mechanical stress and deformation, so that the durability and reliability of the electrical conduit in practical application are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical casings, in particular to a toughened polyvinyl chloride electrical casing and a preparation method thereof. Background Art

[0002] Electrical conduit is a kind of protective material widely used in construction and electrical engineering. It is mainly used in places such as building basements to protect wires and cables and facilitate the installation and maintenance of pipelines. Electrical conduits can be divided into many types according to material and performance, such as rigid conduits, flexible waterproof conduits, steel pipe conduits and iron sheet conduits.

[0003] The defects of existing electrical conduits are: 1. Patent document US07841367B2 discloses a fabric-reinforced PVC tube. However, the PVC tube in the above document has the technical problem of being unable to withstand large mechanical stress and being easily deformed when in use; 2. Patent document US06410852B1 discloses a continuous thread PVC electrical conduit. However, the PVC electrical conduit in the above document has the technical problem of not being able to prevent insects and rodents from eroding it and being easily damaged by insects and rodents; 3. Patent document US06257880B1 discloses a heating box bending PVC conduit, but the PVC conduit in the above document is difficult to cope with the technical problem of changing temperature and climate environment; 4. Patent document CN104300466A discloses a PVC electrical conduit, but the PVC electrical conduit in the above document has the technical problem of poor electrical insulation performance. Summary of the invention

[0004] The object of the present invention is to provide a toughened polyvinyl chloride electrical conduit and a preparation method thereof, so as to solve the technical problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: a toughened polyvinyl chloride electrical conduit, wherein the raw materials for preparing the toughened polyvinyl chloride electrical conduit include polyvinyl chloride resin, modified toughening agent, stabilizer, plasticizer, inorganic flame retardant, filler, dispersant, modified insect repellent and cold-resistant agent; The modified toughening agent is prepared by using phenolic resin, elastomer, antioxidant, lubricant and heat stabilizer, and the weight percentage is 100:5-8:1-3:0.5-1.5:2. The elastomer is ethylene propylene diene monomer rubber, the antioxidant is 2,6-di-tert-butyl-4-methylphenol, the lubricant is calcium stearate or zinc stearate, and the heat stabilizer is tribasic lead sulfate. The preparation method of the modified toughening agent is as follows: Step Si: adding the weighed raw materials into a high-speed mixer and mixing them thoroughly for 5 min to 10 min to obtain a mixture; Step Sii: preheating the mixture obtained in step Si, and after preheating, adding the premixed material into a twin-screw extruder for melt extrusion, with the barrel temperature being 160° C. to 200° C.; Step Siii: cooling the molten extruded material obtained in step Sii through a cooling device to obtain a material solidified into a strip, and pelletizing the solidified strip material to obtain modified toughening agent particles of uniform size; The modified insect repellent is prepared by using diatom mud, natural insect repellent, inorganic gelling material and filler, wherein the weight percentage is 100:8-11:4-9:3-5, the natural insect repellent uses lavender essential oil, the inorganic gelling material uses cement, and the filler uses heavy calcium powder. The preparation steps of the modified insect repellent are as follows: Step (1): adding weighed diatom mud, inorganic gelling material and filler into a mixing box, adding an appropriate amount of water and stirring to form a slurry, and gradually adding a natural insect repellent during the stirring process; Step (2): the slurry stirred in step (1) is allowed to stand for 3 hours to 5 hours to fully age, thereby obtaining a modified insect repellent.

[0006] Preferably, the stabilizer is a calcium zinc stabilizer.

[0007] Preferably, the plasticizer is trioctyl trimellitate.

[0008] Preferably, the inorganic flame retardant is aluminum hydroxide or magnesium hydroxide.

[0009] Preferably, the filler is calcined clay.

[0010] Preferably, the dispersant is sodium polymethacrylate.

[0011] Preferably, the cold-resistant agent is powdered nitrile rubber.

[0012] Preferably, the raw materials for preparing the toughened polyvinyl chloride electrical casing include the following components by weight: 100 parts of polyvinyl chloride resin; Modified toughening agent 5-8 parts; Stabilizer 4-6 parts; Plasticizer 30-42 parts; 5-8 parts of inorganic flame retardant; Filler 5-12 parts; Dispersant 6-9 parts; 4-7 parts of modified insect repellent; 3 to 8 parts of cold-resistant agent.

[0013] Preferably, the preparation steps of the toughened polyvinyl chloride electrical casing are as follows: Step S1, putting the polyvinyl chloride resin, modified toughening agent, stabilizer, plasticizer, inorganic flame retardant, filler, dispersant, modified insect repellent and cold-resistant agent weighed according to the ratio into a mixer, and fully mixing and plasticizing to form a melt; Step S2, extruding the melt obtained in step S1 through an extruder to form a desired sleeve shape; Step S3, cooling and shaping the sleeve extruded in step S2, thereby obtaining the required toughened polyvinyl chloride electrical sleeve.

[0014] Preferably, the temperature of the extruder in step S2 is divided into three zones, the temperature of the feeding zone is 130°C-160°C, the temperature of the metering zone is 165°C-180°C, the temperature of the die extrusion zone is 175°C-190°C, and the pressure of the extruder is 100MPa-160MPa.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts a modified toughening agent to make the electrical casing have higher toughness and be able to withstand greater mechanical stress and deformation, thereby improving its durability and reliability in practical applications; 2. The present invention uses modified insect repellent to make the electrical conduit have a certain ability to prevent insects and rodents from eroding, reducing circuit failures and potential safety hazards caused by insects and rodents biting. The raw materials used are all natural or environmentally friendly materials and do not contain any harmful substances. The use process will not pollute the environment, nor will it cause harm to humans and pets. 3. The invention significantly improves the flame retardant properties of the electrical conduit by adding an inorganic flame retardant, so that it can more effectively prevent the spread of fire in extreme situations such as fire and protect the safety of circuits and equipment. The addition of powdered nitrile rubber enables the electrical conduit to maintain good flexibility and mechanical properties in a low temperature environment, and is suitable for a wider range of temperature and climate environments; 4. The present invention can significantly improve the comprehensive performance of polymer materials by using calcined clay as a filler. The calcined clay is fine and uniform, and has a rich microporous structure, which can effectively improve the processing performance of the material, improve fluidity and plasticity, and reduce energy consumption. At the same time, its microporous structure can also enhance the physical and mechanical properties of the material, such as tensile strength and elastic modulus, as well as wear resistance, oil resistance and aging resistance, thereby extending the service life of the product. In addition, the price of calcined clay is relatively low and its source is wide, which can significantly reduce the cost of the product and improve the economy. More importantly, the components such as alumina in the calcined clay can enhance the thermal stability and weather resistance of the material, improve the electrical insulation performance, so that the product can still maintain good performance under high temperature, harsh environment or occasions requiring high electrical insulation. DETAILED DESCRIPTION

[0016] The following will be described clearly and completely in conjunction with 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 creative work are within the scope of protection of the present invention.

[0017] Example 1-6: Preparation of a toughened polyvinyl chloride electrical casing: This embodiment provides a material for toughening polyvinyl chloride electrical conduit, which is prepared according to the formula in Table 1 and a preparation method comprising the following steps: 1. Preparation of modified toughening agent: 100 parts of weighed phenolic resin, 6 parts of EPDM rubber, 2 parts of 2,6-di-tert-butyl-4-methylphenol, 1 part of calcium stearate and 2 parts of tribasic lead sulfate are added into a high-speed mixer and mixed thoroughly for 8 minutes to obtain a mixture, and the obtained mixture is preheated. After the preheating is completed, the premix is ​​added into a twin-screw extruder for melt extrusion. The barrel temperature is 180° C. The molten extruded material is then cooled by a cooling device to obtain a material solidified into a strip shape, and the solidified strip material is pelletized to obtain modified toughening agent particles of uniform size; 2. Preparation of modified insect repellent: 100 parts of diatom mud, 7 parts of cement and 4 parts of heavy calcium powder were weighed into a mixing box, and an appropriate amount of water was added for stirring to form a slurry. During the stirring process, 9 parts of lavender essential oil were gradually added, and the stirred slurry was allowed to stand for 3h-5h to fully age, thereby obtaining a modified insect repellent; 3. Preparation of toughened polyvinyl chloride electrical casing: 100 parts of polyvinyl chloride resin, 6 parts of modified toughening agent, 5 parts of calcium zinc stabilizer, 36 parts of trioctyl trimellitate, 7 parts of aluminum hydroxide, 9 parts of calcined clay, 7 parts of sodium polymethacrylate, 6 parts of modified insect repellent, and 5 parts of powdered nitrile rubber are put into a mixer, fully mixed and plasticized to form a melt, and then the melt is extruded through an extruder to form a desired sleeve shape. The temperature of the extruder is divided into three zones, the temperature of the feeding zone is 150°C, the temperature of the metering zone is 170°C, the temperature of the die extrusion zone is 190°C, the pressure of the extruder is 120MPa, and finally the extruded sleeve is cooled and shaped to obtain the desired toughened polyvinyl chloride electrical sleeve.

[0018] Comparative Example 1-8: Preparation of a toughened polyvinyl chloride electrical casing: The weight parts of the raw materials used in the following comparative examples are shown in Table 2.

[0019] Comparative Example 1: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, and the difference from Example 1 is that no modified toughening agent is added, and an equal amount (6 parts) of commercially available toughening agent is used instead, and other raw materials, steps and parameters are the same as those in Example 1.

[0020] Comparative Example 2: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1. The difference from Example 1 is that no modified toughening agent is added, and other raw materials, steps and parameters are the same as those in Example 1.

[0021] Comparative Example 3: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, and the difference from Example 1 is that no modified insect repellent is added, and an equal amount (6 parts) of commercially available insect repellent is used instead, and other raw materials, steps and parameters are the same as those in Example 1.

[0022] Comparative Example 4: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1. The difference from Example 1 is that no modified insect repellent is added, and other raw materials, steps and parameters are the same as those in Example 1.

[0023] Comparative Example 5: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, and the difference from Example 1 is that no aluminum hydroxide is added, and other raw materials, steps and parameters are the same as those in Example 1.

[0024] Comparative Example 6: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, except that aluminum hydroxide is not added and is replaced by an equal amount (7 parts) of decabromodiphenyl ether, and other raw materials, steps and parameters are the same as those in Example 1.

[0025] Comparative Example 7: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, and the difference from Example 1 is that calcined clay is not added, and other raw materials, steps and parameters are the same as those in Example 1.

[0026] Comparative Example 8: A toughened polyvinyl chloride electrical conduit is provided, which is prepared by referring to the method of Example 1, and the difference from Example 1 is that powdered nitrile rubber is not added, and other raw materials, steps and parameters are the same as those in Example 1.

[0027] Comparative Example 9: Commercially available polyvinyl chloride electrical conduit.

[0028] Table 1 Weight parts of raw materials used in Examples 1-6

[0029]

[0030] Table 2 Weight parts of raw materials used in Comparative Examples 1-9

[0031]

[0032]

[0033] Performance Testing: Test 1: Impact resistance test: Take a section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 as a representative sample and place it on the test bench. At room temperature, place a drop weight for impact resistance test at 30CM from the top of the sample and let it fall naturally. A total of 12 electrical conduits of each type are tested, and the number of undamaged and cracked conduits is recorded.

[0034] Test 2: Low-temperature impact resistance test: Take a section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 as a representative sample and place it on the test bench, and keep the temperature at -25°C. Place the drop weight for the impact resistance test 30CM from the top of the sample and let it fall naturally. Test 12 electrical conduits of each type, and record the number of undamaged and cracked conduits.

[0035] Test 3: Insect and rodent resistance test: Take a section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 as a representative sample and place it on the test bench. Put mice and ants in the test bench at room temperature, observe for 5 hours and record the biting of the samples by insects and rodents.

[0036] Test 4: Flame retardant performance test: Take a section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 as a representative sample and place it on the test bench. Use a combustion tester to test the flame retardant performance of one end of the sample and record how many seconds it takes for it to go out after ignition. (Note: If it goes out within 15 seconds after ignition, it is excellent).

[0037] Test 5: Toughness test: A section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 was cut as a representative sample and placed on a test bench. A bending force was applied to the sample using a bending tester. A total of 6 pieces of each type of electrical conduits were tested, and the number of conduits that were not damaged or cracked was recorded.

[0038] Test 6: Insulation performance test: A section of the electrical conduits obtained in Examples 1-6 and Comparative Examples 1-9 was cut and placed on a test bench as a representative sample. An insulation resistance tester was used to observe and record the insulation resistance value of the sample.

[0039] Table 3 Performance test of toughened polyvinyl chloride electrical conduit Furthermore, by using a modified toughening agent, the electrical casing has higher toughness and can withstand Greater mechanical stress and deformation, thus improving its durability and reliability in practical applications; As a matrix, phenolic resin itself has certain strength and hardness. The addition of elastomer (EPDM rubber) can effectively absorb and disperse external impact energy, thereby improving the impact resistance and toughness of the material. Antioxidant (2,6-di-tert-butyl-4-methylphenol) can prevent the material from degradation due to oxidation during processing and use, thereby extending the service life of the material. Heat stabilizer (tribasic lead sulfate) can prevent the material from thermal decomposition or thermal degradation at high temperature, ensuring the stability of the material in high temperature environment. The addition of lubricant (calcium stearate or zinc stearate) can reduce the friction and viscosity of the material during processing, improve the fluidity and plasticity of the material, thereby optimizing the processing performance, and then the prepared electrical conduit can significantly improve the impact resistance, weather resistance and heat resistance, thereby extending its service life and improving safety.

[0040] Furthermore, through the use of modified insect repellents, the electrical conduit has a certain ability to prevent insect and rodent erosion, reducing circuit failures and safety hazards caused by insect and rodent bites. The selected raw materials are all natural or environmentally friendly materials and do not contain any harmful substances. During use, it will not cause pollution to the environment, nor cause harm to humans and pets.

[0041] Furthermore, the addition of inorganic flame retardants significantly improves the flame retardant properties of the electrical conduit, which enables it to more effectively prevent the spread of fire and protect the safety of circuits and equipment in extreme situations such as fire. The addition of powdered nitrile rubber enables the electrical conduit to maintain good flexibility and mechanical properties in low temperature environments, making it suitable for a wider range of temperature and climate environments.

[0042] Furthermore, by using calcined clay as a filler, the comprehensive performance of polymer materials can be significantly improved. Calcined clay is fine and uniform, with rich microporous structure, which can effectively improve the processing performance of materials, improve fluidity and plasticity, and reduce energy consumption. At the same time, its microporous structure can also enhance the physical and mechanical properties of materials, such as tensile strength and elastic modulus, as well as wear resistance, oil resistance and aging resistance, thereby extending the service life of the product. In addition, calcined clay is relatively low in price and widely available, which can significantly reduce the cost of products and improve economic efficiency. More importantly, components such as alumina in calcined clay can enhance the thermal stability and weather resistance of materials, improve electrical insulation properties, and enable the product to maintain good performance under high temperature, harsh environment or occasions requiring high electrical insulation.

[0043] Working principle: by adopting modified toughening agent, the electrical conduit has higher toughness and can withstand greater mechanical stress and deformation, thereby improving its durability and reliability in practical applications. The use of modified insect repellent makes the electrical conduit have a certain ability to prevent insect and rodent erosion, reducing circuit failures and safety hazards caused by insect and rodent bites. The selected raw materials are all natural or environmentally friendly materials and do not contain any harmful substances. They will not pollute the environment during use, nor will they cause harm to humans and pets. The addition of inorganic flame retardants significantly improves the flame retardant properties of the electrical conduit, so that it can more effectively prevent the spread of fire in extreme situations such as fire, and protect the safety of circuits and equipment. The addition of powdered nitrile rubber allows the electrical conduit to maintain good flexibility and mechanical properties in low temperature environments. It is suitable for a wider range of temperature and climate environments. Using calcined clay as a filler can significantly improve the comprehensive performance of polymer materials. Calcined clay is fine and uniform, with rich microporous structure, which can effectively improve the processing performance of materials, improve fluidity and plasticity, and reduce energy consumption. At the same time, its microporous structure can also enhance the physical and mechanical properties of materials, such as tensile strength and elastic modulus, as well as wear resistance, oil resistance and aging resistance, thereby extending the service life of the product. In addition, calcined clay is relatively low in price and widely available, which can significantly reduce the cost of products and improve economic efficiency. More importantly, components such as alumina in calcined clay can enhance the thermal stability and weather resistance of materials, improve electrical insulation properties, and enable the product to maintain good performance under high temperature, harsh environment or occasions requiring high electrical insulation.

[0044] 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 features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A toughened polyvinyl chloride electrical casing, characterized in that: The raw materials for preparing toughened polyvinyl chloride electrical conduits include polyvinyl chloride resin, modified toughening agent, stabilizer, plasticizer, inorganic flame retardant, filler, dispersant, modified insect repellent and cold-resistant agent; The modified toughening agent is prepared by using phenolic resin, elastomer, antioxidant, lubricant and heat stabilizer, and the weight percentage is 100:5-8:1-3:0.5-1.5:

2. The elastomer is ethylene propylene diene monomer rubber, the antioxidant is 2,6-di-tert-butyl-4-methylphenol, the lubricant is calcium stearate or zinc stearate, and the heat stabilizer is tribasic lead sulfate. The preparation method of the modified toughening agent is as follows: Step Si: adding the weighed raw materials into a high-speed mixer and mixing them thoroughly for 5 min to 10 min to obtain a mixture; Step Sii: preheating the mixture obtained in step Si, and after preheating, adding the premixed material into a twin-screw extruder for melt extrusion, with the barrel temperature being 160° C. to 200° C.; Step Siii: cooling the molten extruded material obtained in step Sii through a cooling device to obtain a material solidified into a strip, and pelletizing the solidified strip material to obtain modified toughening agent particles of uniform size; The modified insect repellent is prepared by using diatom mud, natural insect repellent, inorganic gelling material and filler, wherein the weight percentage is 100:8-11:4-9:3-5, the natural insect repellent uses lavender essential oil, the inorganic gelling material uses cement, and the filler uses heavy calcium powder. The preparation steps of the modified insect repellent are as follows: Step (1): adding weighed diatom mud, inorganic gelling material and filler into a mixing box, adding an appropriate amount of water and stirring to form a slurry, and gradually adding a natural insect repellent during the stirring process; Step (2): the slurry stirred in step (1) is allowed to stand for 3 hours to 5 hours to fully age, thereby obtaining a modified insect repellent.

2. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The stabilizer is a calcium zinc stabilizer.

3. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The plasticizer is trioctyl trimellitate.

4. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The inorganic flame retardant is aluminum hydroxide or magnesium hydroxide.

5. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The filler is calcined clay.

6. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The dispersant is sodium polymethacrylate.

7. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The cold-resistant agent is powdered nitrile rubber.

8. The toughened polyvinyl chloride electrical casing according to claim 1, characterized in that: The raw materials for preparing the toughened polyvinyl chloride electrical casing include the following components by weight: 100 parts of polyvinyl chloride resin; Modified toughening agent 5-8 parts; Stabilizer 4-6 parts; Plasticizer 30-42 parts; 5-8 parts of inorganic flame retardant; Filler 5-12 parts; Dispersant 6-9 parts; 4-7 parts of modified insect repellent; 3 to 8 parts of cold-resistant agent.

9. The method for preparing a toughened polyvinyl chloride electrical casing according to claim 8, characterized in that: The preparation steps of the toughened polyvinyl chloride electrical casing are as follows: Step S1, putting the polyvinyl chloride resin, modified toughening agent, stabilizer, plasticizer, inorganic flame retardant, filler, dispersant, modified insect repellent and cold-resistant agent weighed according to the ratio into a mixer, and fully mixing and plasticizing to form a melt; Step S2, extruding the melt obtained in step S1 through an extruder to form a desired sleeve shape; Step S3, cooling and shaping the sleeve extruded in step S2, thereby obtaining the required toughened polyvinyl chloride electrical sleeve.

10. The method for preparing a toughened polyvinyl chloride electrical casing according to claim 9, characterized in that: In step S2, the temperature of the extruder is divided into three zones: the temperature of the feeding zone is 130°C-160°C, the temperature of the metering zone is 165°C-180°C, the temperature of the die extrusion zone is 175°C-190°C, and the pressure of the extruder is 100MPa-160MPa.

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