Low-temperature-resistant PVC (polyvinyl chloride) corrugated pipe as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of corrugated pipes, and discloses a low-temperature-resistant PVC corrugated pipe and a preparation method and application thereof.The low-temperature-resistant PVC corrugated pipe is prepared from, by weight, 90-100 parts of PVC, 20-30 parts of HPVC, 15-25 parts of HNBR, 10-15 parts of functional additive, 8-12 parts of cold-resistant agent, 2-3 parts of antioxidant, 2-4 parts of stabilizer and 1-2 parts of lubricant; wherein the functional additive is obtained by grafting diethyl allyl phosphate and glycidyl methacrylate on an ethylene-vinyl acetate copolymer. In a specific PVC / HPVC / HNBR / functional additive system, through the synergistic effect of interface compatibility optimization, low-temperature resistance complementation and mechanical property balance, the PVC corrugated pipe still has excellent performance in a low-temperature environment, and application and popularization in cold regions or seasonal low-temperature time regions are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of corrugated pipes, and in particular relates to a low-temperature resistant PVC corrugated pipe and a preparation method and application thereof. Background Art

[0002] In power transmission and communications projects, cable protection bellows, as key components for ensuring safe cable operation, must withstand long-term, complex environmental conditions. Their performance is directly related to the stability and service life of the power system. These bellows must not only possess excellent mechanical properties (such as sufficient tensile strength, impact resistance, and ring stiffness) to withstand external forces such as compression and vibration, but must also adapt to diverse environmental conditions, including low temperatures, humidity, heat, UV radiation, and chemical corrosion.

[0003] Currently, PVC corrugated conduits for cable protection still face numerous technical limitations in practical applications. In low-temperature environments, especially in cold regions or during seasonal low-temperature periods, traditional PVC materials are susceptible to increased brittleness and loss of flexibility due to reduced molecular chain mobility. This can lead to cracking of the conduits during installation, maintenance, or when subjected to external forces, rendering them ineffective in encapsulating cables and potentially leading to risks such as cable wear and short circuits. Summary of the Invention

[0004] The present invention aims to improve at least one technical problem in the background technology.

[0005] A first aspect of the present invention provides a low-temperature resistant PVC corrugated pipe, comprising the following raw materials in parts by weight: 90-100 parts of PVC, 20-30 parts of HPVC, 15-25 parts of HNBR, 10-15 parts of functional additives, 8-12 parts of cold-resistant agent, 2-3 parts of antioxidant, 2-4 parts of stabilizer, and 1-2 parts of lubricant; The functional additive is obtained by grafting diethyl allyl phosphate and glycidyl methacrylate onto ethylene-vinyl acetate copolymer.

[0006] In the low-temperature resistant PVC corrugated pipe of the present invention, PVC (polyvinyl chloride) is used as the base resin, which has excellent mechanical strength, chemical stability and cost advantages, and provides basic structural support for the corrugated pipe. However, its glass transition temperature is relatively high (about 80°C), and the movement of the molecular chain is restricted in a low-temperature environment, which is prone to brittleness, resulting in decreased toughness and weakened impact resistance of the corrugated pipe. HPVC (high-strength polyvinyl chloride) has a similar chemical structure to PVC, but has a higher degree of polymerization and a longer molecular chain, which can enhance the cohesion of the corrugated pipe, improve the overall rigidity and tensile resistance, and at the same time can adjust the crystallinity of the PVC matrix, improve the processing fluidity of the corrugated pipe, and make up for the insufficient fluidity problem caused by molecular chain entanglement during the processing of PVC. HNBR (hydrogenated nitrile butadiene rubber) has an extremely low glass transition temperature (-50°C to -35°C), and can still maintain the flexibility of the molecular chain at low temperatures. The polar cyano group in its molecular structure can form a weak interaction with the chlorine atoms in PVC and HPVC, thereby increasing The interface bonding between the rubber phase and the plastic phase is strengthened. At the same time, the oil resistance, wear resistance and aging resistance of HNBR can improve the comprehensive service performance of the corrugated pipe. The functional additive is obtained by grafting diethyl allyl phosphate and glycidyl methacrylate onto ethylene-vinyl acetate copolymer (EVA). The EVA segment has good flexibility and compatibility, which can reduce the interfacial tension between the components. The phosphate group of diethyl allyl phosphate can form a coordination bond with the chlorine atoms in PVC and HPVC, thereby enhancing the binding force of components with similar polarity. The epoxy group of glycidyl methacrylate can undergo a ring-opening reaction with the amino and hydroxyl groups in HNBR, thereby strengthening the chemical crosslinking between HNBR and PVC and HPVC, and improving the interfacial compatibility. In addition, the phosphate group of diethyl allyl phosphate also has excellent flame retardant function. It can decompose at high temperature to produce phosphoric acid substances, promote the formation of a dense carbon layer on the surface of the corrugated pipe, isolate oxygen and heat transfer, and inhibit the spread of flame.

[0007] In terms of compatibility, functional additives can act as interfacial compatibilizers, forming chemical or physical bonds with PVC, HPVC, and HNBR through multiple functional groups in the molecular chain, combining with the polar groups (C-Cl) of PVC through coordination bonds, forming entanglement between molecular chains with HPVC, and cross-linking with the polar groups (-CN, -OH) of HNBR through epoxy ring-opening reactions, thereby enabling HPVC and HNBR to be evenly dispersed in the PVC matrix to form a stable "island structure"; in terms of low-temperature resistance, the PVC matrix provides structural strength, HPVC enhances the cohesion of the system, and HNBR as a dispersed phase maintains high elasticity at low temperatures, absorbing impact energy through the rubber phase in the "island structure". The amount of HPVC can be increased, crack propagation can be suppressed, and the low-temperature embrittlement problem of PVC can be solved. At the same time, the functional additives promote the interface bonding of HPVC, HNBR and PVC matrix, avoiding the performance degradation caused by interface peeling at low temperature, so that the material can still maintain a certain impact strength in low-temperature environment. In terms of mechanical properties, the high polymerization degree of HPVC improves the rigidity and tensile properties of the PVC matrix, and the elasticity of HNBR compensates for the brittleness of PVC. The two form a "rigid-flexible balance" through the bridging effect of functional additives, and the grafted chains of functional additives can be entangled between the molecular chains of PVC and HPVC, enhancing the intermolecular force. Combined with antioxidants and stabilizers, the material's anti-aging performance and long-term service stability are further improved.

[0008] Preferably, the grafting rate of diethyl allyl phosphate is 5%-8%, and the grafting rate of glycidyl methacrylate is 3%-4%.

[0009] Diethyl allyl phosphate, as the core flame retardant, requires a certain grafting ratio to provide sufficient phosphorus-containing groups. This ensures that the material effectively decomposes during combustion to produce flame-retardant gases (such as phosphoric anhydride) and form a barrier carbon layer, meeting flame retardancy requirements. Glycidyl methacrylate achieves compatibilization through the reaction of epoxy groups with the polar functional groups of PVC, HPVC, and HNBR. Excessive grafting ratios may lead to excessive crosslinking and reduced flexibility, while too low a grafting ratio may not fully improve interfacial compatibility. A grafting ratio of 3%-4% strikes a balance between compatibilization and material toughness.

[0010] The preparation of the functional additive comprises the following steps: uniformly mixing ethylene-vinyl acetate copolymer, diethyl allyl phosphate, glycidyl methacrylate and an initiator, extruding and granulating, and washing to obtain the functional additive; the extrusion and granulation temperature is 130-140°C.

[0011] Preferably, the cold-resistant agent is obtained by polymerizing dipentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of dipentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:80.

[0012] In the present invention, the cold-resistant agent is an eight-arm star structure. In its unique molecular structure, the eight shorter arm segments have excellent segment mobility, which can move more freely under low temperature conditions, effectively reducing the glass transition temperature and brittle temperature of PVC, so that the PVC corrugated pipe still maintains good flexibility and impact resistance at lower temperatures, and significantly reduces the low-temperature embrittlement phenomenon. At the same time, the structure has excellent compatibility with the PVC matrix. The ester polar group it contains can form a stable interaction with the C-Cl bond in PVC, and the eight side chains provide more action sites with the PVC segment, ensuring that it is evenly dispersed in the matrix, avoiding phase separation, and ensuring the stability and uniformity of the cold-resistant effect. Compared to other structures such as four arms, when the monomers are the same and the total molecular weight is similar, the eight-arm structure has better segment mobility because each arm is shorter, and the molecular free volume is larger, which is more compatible with the PVC molecular packing density, can more efficiently break the rigid stacking of PVC, and the cold-resistant performance is more outstanding. At the same time, there are more contact points and the interface compatibility is more stable, which can significantly improve the low-temperature toughness of the PVC corrugated pipe.

[0013] The preparation of the cold-resistant agent includes the following steps: dipentaerythritol is recrystallized and then polymerized with 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to obtain the cold-resistant agent.

[0014] Preferably, the antioxidant is at least one of thiophenol antioxidants, triazine hindered phenol antioxidants, triisocyanate hindered phenol antioxidants, naphthylamine, diphenylamine, p-diphenylamine and quinoline derivatives; the stabilizer includes at least one of tribasic lead sulfate, dioctyl dimaleate tin, tributyltin oxide and zinc stearate; the lubricant includes at least one of calcium stearate, barium stearate, dioctyl adipate, dioctyl sebacate, oxidized polyethylene wax and pentaerythritol stearate.

[0015] A second aspect of the present invention provides a method for preparing the above-mentioned low-temperature resistant PVC corrugated pipe, comprising the following steps: Mixing PVC, HPVC, HNBR, functional additives, cold-resistant agent, antioxidant, stabilizer and lubricant to obtain a mixed material; The mixed material is plasticized and molded to obtain a low-temperature resistant PVC corrugated pipe.

[0016] The plasticizing temperature is 175°C-190°C, and the molding temperature is 180°C-200°C.

[0017] The difference between the plasticizing temperature and the molding temperature does not exceed 5°C.

[0018] A third aspect of the present invention provides use of the above-mentioned low-temperature resistant PVC corrugated tube in cable protection.

[0019] Beneficial effects of the present invention: In the specific PVC / HPVC / HNBR / functional additive system, the present invention achieves the synergistic effects of optimized interface compatibility, complementary low-temperature resistance, and balanced mechanical properties, so that the PVC corrugated pipe still has excellent performance in a low-temperature environment, which is conducive to its use and promotion in cold areas or areas with seasonal low temperatures. DETAILED DESCRIPTION

[0020] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content of the present invention record, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the application's appended claims.

[0021] Example 1 A low-temperature-resistant PVC corrugated pipe comprises the following raw materials in parts by weight: 96 parts of PVC, 24 parts of HPVC, 18 parts of HNBR, 13 parts of functional additives, 10 parts of cold-resistant agent, 2.5 parts of thiophenol antioxidant, 3 parts of tributyltin oxide (stabilizer), and 1 part of calcium stearate (lubricant); Among them, the functional additive is obtained by grafting diethyl allyl phosphate (grafting rate is 7%) and glycidyl methacrylate (grafting rate is 4%) on ethylene-vinyl acetate copolymer; The preparation of the functional additive comprises the following steps: placing ethylene-vinyl acetate copolymer, diethyl allyl phosphate, glycidyl methacrylate, and benzoyl peroxide (initiator) in a mass ratio of 100:9:6:1 in a high-speed mixer and mixing them uniformly (stirring at 800 rpm for 20 minutes), then placing them in an extruder for extrusion granulation (extrusion granulation temperature is 140° C.), washing with ethanol and deionized water to remove unreacted monomers and initiator residues, and drying to obtain the functional additive; The cold-resistant agent is obtained by polymerizing dipentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of dipentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:80. The preparation of the cold-resistant agent comprises the following steps: dipentaerythritol is recrystallized and then polymerized with 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to obtain the cold-resistant agent.

[0022] The preparation method of the low-temperature resistant PVC corrugated pipe of Example 1 is as follows: PVC, HPVC, HNBR, functional additives, cold-resistant agent, thiophenol antioxidant, tributyltin oxide and calcium stearate are put into a high-speed mixer and mixed (stirred at 800 r / min for 30 min) to obtain a mixed material; The mixed material is put into an extruder for plasticization (plasticization temperature is 180°C) and molding (molding temperature is 185°C), and finally cut to obtain a low-temperature resistant PVC corrugated pipe.

[0023] Example 2 A low-temperature-resistant PVC corrugated pipe comprises the following raw materials in parts by weight: 92 parts of PVC, 27 parts of HPVC, 20 parts of HNBR, 11 parts of functional additives, 8 parts of cold-resistant agent, 2.7 parts of isocyanate hindered phenol antioxidant, 2.5 parts of dioctyl dimaleate tin (stabilizer), and 1.2 parts of dioctyl sebacate (lubricant); Among them, the functional additive is obtained by grafting diethyl allyl phosphate (grafting rate is 6%) and glycidyl methacrylate (grafting rate is 3%) on ethylene-vinyl acetate copolymer; The preparation of the functional additive comprises the following steps: placing ethylene-vinyl acetate copolymer, diethyl allyl phosphate, glycidyl methacrylate, and benzoyl peroxide (initiator) in a mass ratio of 100:8:5:1 in a high-speed mixer and mixing them uniformly (stirring at 800 rpm for 20 minutes), then placing them in an extruder for extrusion granulation (extrusion granulation temperature is 140° C.), washing with ethanol and deionized water to remove unreacted monomers and initiator residues, and drying to obtain the functional additive; The cold-resistant agent is obtained by polymerizing dipentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of dipentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:80. The preparation of the cold-resistant agent comprises the following steps: dipentaerythritol is recrystallized and then polymerized with 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to obtain the cold-resistant agent.

[0024] The preparation method of the low-temperature resistant PVC corrugated pipe of Example 2 is as follows: PVC, HPVC, HNBR, functional additives, cold-resistant agent, thiophenol antioxidant, tributyltin oxide and calcium stearate are put into a high-speed mixer and mixed (stirred at 800 r / min for 30 min) to obtain a mixed material; The mixed material is put into an extruder for plasticization (plasticization temperature is 185°C) and molding (molding temperature is 190°C), and finally cut to obtain a low-temperature resistant PVC corrugated pipe.

[0025] Example 3 A low-temperature resistant PVC corrugated pipe comprises the following raw materials in parts by weight: 100 parts of PVC, 21 parts of HPVC, 18 parts of HNBR, 12 parts of functional additives, 11 parts of cold-resistant agent, 3 parts of triazine hindered phenol antioxidant, 2 parts of zinc stearate (stabilizer), and 1.5 parts of dioctyl adipate (lubricant); Among them, the functional additive is obtained by grafting diethyl allyl phosphate (grafting rate is 6%) and glycidyl methacrylate (grafting rate is 4%) on ethylene-vinyl acetate copolymer; The preparation of the functional additive comprises the following steps: placing ethylene-vinyl acetate copolymer, diethyl allyl phosphate, glycidyl methacrylate, and benzoyl peroxide (initiator) in a mass ratio of 100:8:6:1 in a high-speed mixer and mixing them uniformly (stirring at 800 rpm for 20 minutes), then placing them in an extruder for extrusion granulation (extrusion granulation temperature is 140°C), washing them with ethanol and deionized water to remove unreacted monomers and initiator residues, and drying them to obtain the functional additive; The cold-resistant agent is obtained by polymerizing dipentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of dipentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:80. The preparation of the cold-resistant agent comprises the following steps: dipentaerythritol is recrystallized and then polymerized with 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to obtain the cold-resistant agent.

[0026] The preparation method of the low-temperature resistant PVC corrugated pipe of Example 3 is as follows: PVC, HPVC, HNBR, functional additives, cold-resistant agent, thiophenol antioxidant, tributyltin oxide and calcium stearate are put into a high-speed mixer and mixed (stirred at 800 r / min for 30 min) to obtain a mixed material; The mixed material is put into an extruder for plasticization (plasticization temperature is 190°C) and molding (molding temperature is 190°C), and finally cut to obtain a low-temperature resistant PVC corrugated pipe.

[0027] Comparative Example 1 A PVC corrugated pipe is different from Example 1 in that the weight portion of HPVC is 5 parts. Other aspects are the same as Example 1.

[0028] Comparative Example 2 A PVC corrugated pipe is different from Example 1 in that the weight portion of HPVC is 40 parts. Other aspects are the same as Example 1.

[0029] Comparative Example 3 A PVC corrugated pipe is different from Example 1 in that the weight portion of HNBR is 3 parts. Other aspects are the same as Example 1.

[0030] Comparative Example 4 A PVC corrugated pipe is different from Example 1 in that the weight portion of HNBR is 35 parts. Other aspects are the same as Example 1.

[0031] Comparative Example 5 A PVC corrugated pipe is different from Example 1 in that no functional additive is added. Other aspects are the same as Example 1.

[0032] Comparative Example 6 A PVC corrugated pipe is different from Example 1 in that the grafting rate of diethyl allyl phosphate in the functional additive is 2%. Other aspects are the same as Example 1.

[0033] Comparative Example 7 A PVC corrugated pipe differs from Example 1 in that the grafting rate of glycidyl methacrylate in the functional additive is 1%. Other aspects are the same as Example 1.

[0034] Comparative Example 8 A PVC corrugated pipe differs from Example 1 in that the grafting rate of glycidyl methacrylate in the functional additive is 8%. Other aspects are the same as Example 1.

[0035] Comparative Example 9 A PVC corrugated pipe is different from Example 1 in that the functional additive is obtained by grafting diethyl allyl phosphate and glycidyl methacrylate onto PE. Other aspects are the same as Example 1.

[0036] Comparative Example 10 A PVC corrugated pipe is different from the embodiment 1 in that no cold-resistant agent is added. Other aspects are the same as the embodiment 1.

[0037] Comparative Example 11 A PVC corrugated pipe differs from Example 1 in that: the cold-resistant agent is obtained by polymerizing pentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of pentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:20. Other aspects are the same as Example 1.

[0038] Effect test The performance tests of the products obtained in the above examples and comparative examples were carried out, and the relevant test methods are as follows: Tensile strength test: carried out in accordance with ISO 527-1 and ISO 527-2; Flame retardancy - Limiting Oxygen Index (LOI) test: carried out in accordance with ISO 4589-2; Proof Tracking Index (PTI) test: carried out in accordance with GB / T 4207-2012; Low temperature brittleness test: carried out in accordance with GB / T 15256-2014; The test results are shown in Table 1.

[0039] Table 1 Performance test results Combined with the data in Table 1, compared with Example 1, the amount of HPVC in Comparative Example 1 is too little. Due to insufficient HPVC, the rigid support is weakened, the tensile strength and low-temperature resistance of the material are reduced, the tensile strength is significantly reduced, and the low-temperature brittle temperature is increased; the amount of HPVC in Comparative Example 2 is too much, which reduces the toughness of the corrugated pipe, deviates from the optimal state, the tensile strength is slightly reduced, and the low-temperature brittle temperature is increased; the amount of HNBR in Comparative Example 3 is too little, which cannot provide sufficient low-temperature elasticity, the brittleness of the material increases, the tensile strength is significantly reduced, and the low-temperature brittle temperature is greatly increased; the amount of HNBR in Comparative Example 4 is too much. Although the low-temperature brittle temperature is slightly improved, the excessive rubber phase weakens the rigidity of the corrugated pipe, resulting in a decrease in overall mechanical properties; the lack of functional additives in Comparative Example 5 leads to extremely poor compatibility of the components, the disappearance of synergistic effect, and the overall deterioration of flame retardancy, tracking resistance and low-temperature resistance; the diethyl allyl phosphate grafting of the functional additive in Comparative Example 6 is too little, and due to insufficient phosphate groups, the flame retardancy and compatibility are weakened; In comparative example 7, the glycidyl methacrylate of the functional additive is grafted too little, and due to insufficient epoxy groups, the interfacial bonding force between the HNBR phase and the PVC and HPVC phases is weakened, the compatibility is reduced, the tensile strength is significantly reduced, and the low-temperature brittle temperature is increased; in comparative example 8, the glycidyl methacrylate of the functional additive is grafted too much, and the excessive epoxy groups cause excessive cross-linking of the molecular chain, the toughness of the material is damaged, the tensile strength of the corrugated pipe is reduced, and the low-temperature brittle temperature is increased; in comparative example 9, PE is a non-polar hydrocarbon chain structure, which has poor compatibility with PVC, HPVC, and HNBR, affecting the bonding between PVC, HPVC, and HNBR, and the synergistic effect cannot be exerted; in comparative example 10, due to the lack of a cold-resistant agent, the low-temperature fluidity of the molecular chain cannot be effectively improved, resulting in deterioration of the low-temperature resistance; in comparative example 11, the cold-resistant agent obtained by polymerization is a four-arm star structure. The four-arm star structure has fewer branches than the eight-arm star structure, and its dispersibility in the system is weaker than that of the eight-arm star structure. The toughening effect is relatively weak, which increases the low-temperature brittle temperature of the corrugated pipe.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A low-temperature resistant PVC corrugated pipe, characterized in that: The invention comprises the following raw materials in parts by weight: 90-100 parts of PVC, 20-30 parts of HPVC, 15-25 parts of HNBR, 10-15 parts of functional additives, 8-12 parts of cold-resistant agent, 2-3 parts of antioxidant, 2-4 parts of stabilizer, and 1-2 parts of lubricant; The functional additive is obtained by grafting diethyl allyl phosphate and glycidyl methacrylate onto ethylene-vinyl acetate copolymer.

2. The low-temperature resistant PVC corrugated pipe according to claim 1, characterized in that: The grafting rate of the diethyl allyl phosphate is 5%-8%, and the grafting rate of the glycidyl methacrylate is 3%-4%.

3. The low-temperature resistant PVC corrugated pipe according to claim 2, characterized in that: The preparation of the functional additive comprises the following steps: uniformly mixing the ethylene-vinyl acetate copolymer, the diethyl allyl phosphate, the glycidyl methacrylate and the initiator, extruding and granulating, and washing to obtain the functional additive; the extrusion and granulation temperature is 130-140°C.

4. The low-temperature resistant PVC corrugated pipe according to claim 1, characterized in that: The cold-resistant agent is obtained by polymerizing dipentaerythritol and 3,6-dimethyl-1,4-dioxane-2,5-dione, and the molar ratio of the dipentaerythritol to the 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:

80.

5. The low-temperature resistant PVC corrugated pipe according to claim 4, characterized in that: The preparation of the cold-resistant agent comprises the following steps: the dipentaerythritol is recrystallized and then polymerized with the 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to obtain the cold-resistant agent.

6. The low-temperature resistant PVC corrugated pipe according to claim 1, characterized in that: The antioxidant is at least one of thiophenol antioxidants, triazine hindered phenol antioxidants, triisocyanate hindered phenol antioxidants, naphthylamine, diphenylamine, p-diphenylamine and quinoline derivatives; and / or the stabilizer includes at least one of tribasic lead sulfate, dioctyl dimaleate tin, tributyltin oxide and zinc stearate; and / or the lubricant includes at least one of calcium stearate, barium stearate, dioctyl adipate, dioctyl sebacate, oxidized polyethylene wax and pentaerythritol stearate.

7. A method for preparing a low-temperature resistant PVC corrugated pipe according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing the PVC, the HPVC, the HNBR, the functional additive, the cold-resistant agent, the antioxidant, the stabilizer, and the lubricant to obtain a mixed material; The mixed material is plasticized and molded to obtain the low-temperature resistant PVC corrugated pipe.

8. The method for preparing a low-temperature resistant PVC corrugated pipe according to claim 7, characterized in that: The plasticizing temperature is 175°C-190°C, and the molding temperature is 180°C-200°C.

9. The method for preparing a low-temperature resistant PVC corrugated pipe according to claim 8, characterized in that: The difference between the plasticizing temperature and the molding temperature does not exceed 5°C.

10. Use of the low-temperature resistant PVC corrugated tube according to any one of claims 1 to 6 in cable protection.

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