A PVC cable sheath material and its preparation method, and a cold-resistant and flame-retardant cable.

Abstract

This invention discloses a PVC cable sheath material, comprising the following components by weight: 100 parts PVC resin; 26-40 parts cold-resistant rubber; 45-53 parts cold-resistant plasticizer; 45-52 parts filler; 10-26 parts flame retardant; 9-15 parts heat stabilizer; 0.5-1.2 parts antioxidant; 2.0-3.5 parts lubricant; and 0-1.2 parts colorant. This invention also discloses a method for preparing the PVC cable sheath material and a cold-resistant and flame-retardant cable. The PVC cable sheath material of this invention has excellent cold resistance and flame retardancy, and can meet the requirements for cable sheath use in extremely cold environments of ~40℃ and below.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, specifically relating to a PVC cable sheath material and its preparation method, as well as a cold-resistant and flame-retardant cable. Background Technology

[0002] In recent years, the requirements for extreme environment applications and installation of wires and cables have been continuously increasing, and the manufacturing technology of wires and cables has also made rapid progress. Due to different regions, especially special environments (such as -40℃ extreme cold environments), special purpose cables with different performance are required.

[0003] Cable sheaths are layers of rubber or rubber-synthetic sheaths that protect cables from the influence of the natural environment and external factors. They provide insulation and protect the internal conductors of the cable from damage. The quality of cable sheaths depends on the insulation performance, fire resistance, and mechanical properties of the sheath material. PVC-based cable sheath materials are common; however, PVC itself is a brittle material with poor low-temperature resistance, which can affect the cold resistance and flame retardant properties of the cable sheath. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a PVC cable sheath material and its preparation method, as well as a cold-resistant and flame-retardant cable. The PVC cable sheath material has excellent cold resistance and flame retardancy, and can meet the requirements for cable sheath use in extremely cold environments of -40℃ and below.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is:

[0006] According to a first aspect of the present invention, a PVC cable sheath material is provided, comprising the following components in parts by weight:

[0007] 100 parts of PVC resin;

[0008] 26-40 parts of cold-resistant rubber;

[0009] 45-53 parts of cold-resistant plasticizer;

[0010] 45-52 parts of filler;

[0011] 10-26 parts flame retardant;

[0012] Heat stabilizer 9-15 parts;

[0013] Antioxidant 0.5–1.2 parts;

[0014] 2.0 to 3.5 parts of lubricant;

[0015] Colorant 0-1.2 parts.

[0016] Preferably, the degree of polymerization of the PVC resin is one or more of 1000, 1300, and 2500, and when there is a combination of multiple degrees of polymerization, the weight ratio of the PVC resins with degrees of polymerization of 1000, 1300, and 2500 is 1:(1-2):(5-7).

[0017] Preferably, the cold-resistant rubber is one or a combination of two of liquid nitrile rubber and liquid chlorinated rubber. When it is a combination of two, the weight ratio of the liquid nitrile rubber to the liquid chlorinated rubber is 1:(1 to 1.5).

[0018] Preferably, the cold-resistant plasticizer is a combination of two or more of dioctyl terephthalate (DOTP), diisodecyl phthalate (DIDP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester.

[0019] Preferably, the filler is one of light calcium carbonate, heavy calcium carbonate, and calcined kaolin.

[0020] Preferably, the flame retardant is a combination of zinc borate, antimony trioxide, and chlorinated paraffin, wherein the weight ratio of zinc borate, antimony trioxide, and chlorinated paraffin is (1-4):(1-4):(1-5).

[0021] Preferably, the heat stabilizer is one or a combination of two of the following: calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer. When it is a combination of two, the weight ratio of the calcium-zinc composite heat stabilizer to the rare earth calcium-zinc composite heat stabilizer is (1-4):(1-5).

[0022] Preferably, the antioxidant is bisphenol A.

[0023] Preferably, the lubricant is any two or three of polyethylene wax, ethylene bis-stearamide (EBS), calcium stearate, and barium stearate.

[0024] Preferably, the colorant is a black masterbatch.

[0025] According to a second aspect of the present invention, a method for preparing PVC cable sheath material is provided, comprising:

[0026] Ingredients: According to the PVC cable sheath material described above, weigh out PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant, and divide them into main materials, oils, and minor materials;

[0027] Hot mixing: The main ingredient, the oil, and the minor ingredients are added to a hot mixing tank in sequence and mechanically stirred until the main ingredient, oil, and minor ingredients are mixed and heated to 95-115°C by friction to obtain a hot mixture.

[0028] Cold mixing: The hot mixture is added to a cold mixing tank and stirred and mixed, and then cooled until the hot mixture is cooled to 40-60°C to obtain a cold mixture;

[0029] Plasticizing: The cold mixture is added to a twin-screw extruder and then heated and plasticized to obtain a plasticized material.

[0030] Granulation: The plasticized material is added to a single screw extruder for granulation to obtain plastic granules;

[0031] Cooling: After cooling the plastic granules, PVC cable sheath material is obtained.

[0032] Preferably, the main material includes PVC resin, filler, and heat stabilizer;

[0033] The oil contains a cold-resistant plasticizer, and the method further includes stirring the cold-resistant plasticizer at 25–65°C for 20–35 min before adding the oil to the hot mixing tank;

[0034] The minor components include cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant.

[0035] Preferably, the stirring speed in the hot mixing step is 475–950 r / min.

[0036] Preferably, in the cold mixing step, the cooling process uses cooling water at 0-20°C.

[0037] Preferably, the temperature of the plasticizing and mixing is 100-160°C, and the temperature of the extrusion granulation is 100-160°C.

[0038] According to a third aspect of the present invention, a cold-resistant and flame-retardant cable is provided, comprising a sheath, wherein the sheath is made of the PVC cable sheath material described above.

[0039] Beneficial effects:

[0040] The PVC cable sheath material of this invention, compared with traditional PVC cable sheath materials, has excellent cold resistance and flame retardancy. Its low-temperature resistance can reach -40℃ to -45℃, its oxygen index can reach 28% to 35%, and its flame retardant efficiency is significant, fully meeting the requirements for cable sheath use in extremely cold environments at -40℃ and below. Furthermore, its tensile strength is ≥

[0041] The tensile strength at break is ≥280% (16.5 MPa), the maximum change rate of tensile strength after aging at 100℃ for 168 hours is 5%–12%, the maximum change rate of tensile strain at break is -10%–-17%, the thermal deformation is ≤40%, the thermal stability time at 200℃ is ≥90 min, and the mass loss after aging at 100℃ for 168 hours is ≤14.9 g / m³. 2 It meets the requirements of GB / T1040.3 and GB / T8815-2008 standards and has excellent machinability.

[0042] The preparation method of the PVC cable sheath material of the present invention is simple and easy to operate.

[0043] The cold-resistant and flame-retardant cable of this embodiment can be used in extremely cold environments of -40℃ and below. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating the preparation method of PVC cable sheath material in an embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0046] Example 1

[0047] This embodiment discloses a PVC cable sheath material, which comprises the following components in parts by weight:

[0048] 100 parts of PVC resin;

[0049] 26-40 parts of cold-resistant rubber;

[0050] 45-53 parts of cold-resistant plasticizer;

[0051] 45-52 parts of filler;

[0052] 10-26 parts flame retardant;

[0053] Heat stabilizer 9-15 parts;

[0054] Antioxidant 0.5–1.2 parts;

[0055] 2.0 to 3.5 parts of lubricant;

[0056] Colorant 0-1.2 parts.

[0057] Specifically, the polyvinyl chloride (PVC) resin has a degree of polymerization of one or more of 1000, 1300, and 2500. When there is a combination of multiple degrees of polymerization, the weight ratio of the PVC resin with a degree of polymerization of 1000, 1300, and 2500 is 1:(1-2):(5-7).

[0058] Specifically, the cold-resistant rubber is one or a combination of two of liquid nitrile rubber and liquid chlorinated rubber. When it is a combination of two, the weight ratio of liquid nitrile rubber to liquid chlorinated rubber is 1:(1 to 1.5).

[0059] Specifically, the cold-resistant plasticizer is a combination of two or more of dioctyl terephthalate (DOTP), diisodecyl phthalate (DIDP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester. For example, it can be a composition of DOTP, DOS, and DOS mixed in a weight ratio of 1:1:1.25, or a composition of DOTP, DOS, and DOS mixed in a weight ratio of 2:3:3, or a composition of DOS and DOS mixed in a weight ratio of 1:1.25. The specific choice can be made according to the requirements, which will not be elaborated here.

[0060] Specifically, the filler is one of light calcium carbonate, heavy calcium carbonate, and calcined kaolin.

[0061] Specifically, the flame retardant is a combination of zinc borate, antimony trioxide, and chlorinated paraffin, with the weight ratio of zinc borate, antimony trioxide, and chlorinated paraffin being (1-4):(1-4):(1-5).

[0062] Specifically, the heat stabilizer is one or a combination of two of the following: calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer. When it is a combination of two, the weight ratio of calcium-zinc composite heat stabilizer to rare earth calcium-zinc composite heat stabilizer is (1-4):(1-5).

[0063] Specifically, the antioxidant is bisphenol A (diphenol propane).

[0064] Specifically, the lubricant is a combination of two or three of the following: polyethylene wax, ethylene bis-stearamide (EBS), calcium stearate, and barium stearate. For example, it can be a composition of EBS and calcium stearate mixed in a weight ratio of 2:3, or a composition of EBS, calcium stearate, and barium stearate mixed in a weight ratio of 1:1:1. The specific choice can be made according to the requirements, which will not be elaborated here.

[0065] Specifically, the colorant is a black masterbatch.

[0066] Compared to traditional PVC cable sheath materials, the PVC cable sheath material of this embodiment exhibits superior cold resistance and flame retardancy. Its low-temperature catalytic performance can reach -40℃ to -45℃, its oxygen index can reach 28% to 35%, and its flame retardant efficiency is significant, fully meeting the requirements for cable sheath use in extremely cold environments at -40℃ and below. Furthermore, its tensile strength is ≥16.5 MPa, its tensile strain at break is ≥280%, the maximum change rate of tensile strength after aging at 100℃ for 168 hours is 5% to 12%, the maximum change rate of tensile strain at break after aging at 100℃ for 168 hours is -10% to -17%, its heat deformation is ≤40%, its thermal stability time at 200℃ is ≥90 minutes, and its mass loss after aging at 100℃ for 168 hours is ≤14.9 g / m³. 2 It meets the requirements of GB / T1040.3 and GB / T8815-2008 standards and has excellent machinability.

[0067] Example 2

[0068] like Figure 1 As shown, this embodiment discloses a method for preparing PVC cable sheath material, which includes the following steps:

[0069] Ingredients: According to the PVC cable sheath material described in Example 1, weigh out PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant, and divide them into main materials, oils, and minor materials;

[0070] Hot mixing: The main ingredients, oil, and minor ingredients are added to the hot mixing tank in sequence and mechanically stirred until the temperature of the mixture of main ingredients, oil, and minor ingredients rises to 95-115°C by friction, and then the mixing is stopped to obtain the hot mixture.

[0071] Cold mixing: Add the hot mix to the cold mixing tank and continue stirring and mixing while cooling to prevent the hot mix from becoming too hot and clumping. Stop stirring when the temperature of the hot mix cools down to 40-60°C to obtain the cold mix.

[0072] Plasticizing: Cold mix is ​​added to a twin-screw extruder, and after heating and plasticizing, plasticized material is obtained.

[0073] Granulation: Plasticizing materials are added to a single screw extruder for granulation to obtain plastic granules;

[0074] Cooling: After cooling the plastic granules, PVC cable sheath material products can be obtained.

[0075] Specifically, the main ingredients include PVC resin, fillers, and heat stabilizers. The oils include cold-resistant plasticizers; before adding the oils to the hot mixing tank, this method also includes mixing various cold-resistant plasticizers at 25–65°C for 20–35 minutes to obtain a cold-resistant plasticizer mixture, i.e., the oils. The minor ingredients include cold-resistant rubber, flame retardants, antioxidants, lubricants, and colorants.

[0076] In the hot mixing step, the mechanical stirring speed is 475–950 r / min, i.e., high-speed stirring. The hot-roller blades in the mixing tank rapidly tumble the main ingredients, oils, and minor components, causing them to generate heat through self-friction against the inner wall of the mixing tank and the blades, raising the temperature to 95–115°C. This allows the moisture in the main ingredients, oils, and minor components to evaporate as steam, eliminating the need for an external heat source. Simultaneously, it ensures thorough and uniform mixing of the main ingredients, oils, and minor components, allowing the cold-resistant plasticizer to be fully absorbed into the PVC resin. Higher temperatures require longer stirring times, and lower temperatures require shorter stirring times, typically approximately 5–15 minutes.

[0077] In the cold mixing step, the cooling process uses cooling water at 0-20℃, and the stirring speed is preferably 475-950 r / min, which usually takes about 5-10 minutes.

[0078] During the plasticizing process, the heating temperature is 100-160℃ to ensure that all raw materials are fully plasticized and mixed evenly.

[0079] In the granulation step, the extrusion granulation temperature is 100–160℃.

[0080] In practice, the main ingredients are weighed according to the amount required for each production run and added to the hot mixing tank. The oil can be weighed according to the formula ratio based on the production batch. During production, it is automatically weighed and added to the hot mixing tank containing the main ingredients by electronic scales and other automatic metering equipment. The minor ingredients are accurately weighed according to the amount required for each production run and packed into separate packaging bags, one bag per run.

[0081] The preparation method of the PVC cable sheath material in this embodiment is simple and easy to operate.

[0082] The following are several specific preparation examples to illustrate the method of this embodiment in detail. The raw material formulations for each preparation example are shown in Table 1.

[0083] Table 1. Raw material formulations for preparation examples 1-5

[0084]

[0085]

[0086] Preparation Example 1

[0087] Ingredients: Weigh out PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant according to Preparation Example 1 in Table 1. The PVC resin is a mixture of three PVC resins with polymerization degrees of 1000, 1300, and 2500 in a weight ratio of 1:2:5; the cold-resistant rubber is liquid nitrile rubber; the cold-resistant plasticizer is a mixture of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester in a weight ratio of 1:1:1.25; the filler is light calcium carbonate; the flame retardant is zinc borate, triethylene glycol diisodecyl ester, and triethylene glycol diisodecyl ester. A composition of antimony oxide and chlorinated paraffin mixed in a weight ratio of 1:1:1; a rare earth calcium-zinc composite heat stabilizer; an antioxidant of bisphenol A (bisphenol A propane); a lubricant of EBS (ethylene bis-stearamide) and calcium stearate mixed in a weight ratio of 1:1; a colorant of black masterbatch; and the addition of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester to an oil storage tank, followed by stirring at 25°C for 35 minutes to obtain an oil; and the mixing of cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant to obtain a smaller mixture;

[0088] Hot mixing: PVC resin, filler, heat stabilizer, oil, and other minor ingredients are added to a hot mixing tank in sequence and stirred at a high speed of 600 r / min until the mixture of all materials in the hot mixing tank is heated to 95°C by friction heating, and then the mixture is stopped to obtain the hot mix.

[0089] Cold mixing: Add the hot mix to the cold mixing tank and continue mixing at a stirring speed of 600 r / min. Use cooling water at 0-20℃ to cool the cold mixing tank until the temperature of the hot mix in the cold mixing tank drops to 40℃, then stop mixing to obtain the cold mix.

[0090] Plasticizing: The cold mixture is added to a twin-screw extruder and plasticized and mixed at 100°C for 10 minutes to obtain a plasticized material;

[0091] Granulation: Plasticized material is added to a single screw extruder and extruded and granulated at 110°C to obtain plastic granules;

[0092] Cooling: After the plastic granules are cooled by air cooling, they can be packaged and stored to obtain PVC cable sheath material products.

[0093] Preparation Example 2

[0094] Ingredients: PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant were weighed according to Preparation Example 2 in Table 1. The PVC resin was a mixture of three PVC resins with degrees of polymerization of 1000, 1300, and 2500 in a weight ratio of 1:1:7; the cold-resistant rubber was a mixture of liquid nitrile rubber and liquid chlorinated rubber in a weight ratio of 1:1; the cold-resistant plasticizer was a mixture of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester in a weight ratio of 2:2:3; the filler was calcined kaolin; and the flame retardant was boric acid. A composition consisting of zinc, antimony trioxide, and chlorinated paraffin in a weight ratio of 2:2:3; a composition consisting of calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer in a weight ratio of 2:3; an antioxidant consisting of bisphenol A (bisphenol A propane); a lubricant consisting of calcium stearate and barium stearate in a weight ratio of 1:1; and a colorant consisting of black masterbatch. Dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester are added to an oil storage tank and stirred at 35°C for 30 minutes to obtain an oil. Cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant are then mixed to obtain a smaller batch.

[0095] Hot mixing: PVC resin, filler, heat stabilizer, oil, and other minor ingredients are added to a hot mixing tank in sequence and stirred at a high speed of 600 r / min until the mixture of all materials in the hot mixing tank is heated to 100°C by friction heating, and then the mixture is stopped to obtain the hot mix.

[0096] Cold mixing: Add the hot mix to the cold mixing tank and continue mixing at a stirring speed of 700 r / min. Use cooling water at 0-20℃ to cool the cold mixing tank until the temperature of the hot mix in the cold mixing tank drops to 45℃, then stop mixing to obtain the cold mix.

[0097] Plasticizing: The cold mixture is added to a twin-screw extruder and plasticized and mixed at 115°C for 8 minutes to obtain a plasticized material;

[0098] Granulation: Plasticized material is added to a single screw extruder and extruded and granulated at 120°C to obtain plastic granules;

[0099] Cooling: After the plastic granules are cooled by air cooling, they can be packaged and stored to obtain PVC cable sheath material products.

[0100] Preparation Example 3

[0101] Ingredients: PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant were weighed according to Preparation Example 3 in Table 1. The PVC resin was a PVC resin with a degree of polymerization of 2500; the cold-resistant rubber was liquid nitrile rubber; the cold-resistant plasticizer was a composition of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester in a weight ratio of 2:3:3; the filler was heavy calcium carbonate; the flame retardant was a composition of zinc borate, antimony trioxide, and chlorinated paraffin in a weight ratio of 4:4:5; and the heat stabilizer was prepared according to the ingredients listed in Table 1. The stabilizer is a composition of calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer mixed in a weight ratio of 4:5; the antioxidant is bisphenol A (diphenol propane); the lubricant is a composition of EBS (ethylene bis-stearamide) and calcium stearate mixed in a weight ratio of 2:3; the colorant is black masterbatch, and dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester are added to the oil storage tank and stirred at 45°C for 25 minutes to obtain the oil. The cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant are mixed to obtain the small material.

[0102] Hot mixing: PVC resin, filler, heat stabilizer, oil, and other small ingredients are added to a hot mixing tank in sequence and stirred at a high speed of 800 r / min until the mixture of all materials in the hot mixing tank is heated to 105°C by friction heating, and then the mixture is stopped to obtain the hot mix.

[0103] Cold mixing: Add the hot mix to the cold mixing tank and continue mixing at a stirring speed of 800 r / min. Use cooling water at 0-20℃ to cool the cold mixing tank until the temperature of the hot mix in the cold mixing tank drops to 50℃, then stop mixing to obtain the cold mix.

[0104] Plasticizing: The cold mixture is added to a twin-screw extruder and plasticized and mixed at 130°C for 10 minutes to obtain a plasticized material;

[0105] Granulation: Plasticized material is added to a single screw extruder and extruded and granulated at 130°C to obtain plastic granules;

[0106] Cooling: After the plastic granules are cooled by air cooling, they can be packaged and stored to obtain PVC cable sheath material products.

[0107] Preparation Example 4

[0108] Ingredients: PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant were weighed according to Preparation Example 4 in Table 1. The PVC resin was a mixture of three PVC resins with degrees of polymerization of 1000, 1300, and 2500 in a weight ratio of 1:1:5; the cold-resistant rubber was liquid nitrile rubber; the cold-resistant plasticizer was a mixture of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester in a weight ratio of 1:1.5:1.5; the filler was light calcium carbonate; and the flame retardant was zinc borate, antimony trioxide, and chlorinated paraffin in a weight ratio of 2:3:3. A composition of mixed components in weight ratios; a composition of calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer mixed in a 1:1 weight ratio; an antioxidant of bisphenol A (diphenol propane); a composition of EBS (ethylene bis-stearamide), calcium stearate, and barium stearate mixed in a 1:1:1 weight ratio; a colorant of black masterbatch; and the addition of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester to an oil storage tank and stirring at 55°C for 20 minutes to obtain an oil; and the mixing of cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant to obtain a small component;

[0109] Hot mixing: PVC resin, filler, heat stabilizer, oil, and other minor ingredients are added to a hot mixing tank in sequence and stirred at a high speed of 600 r / min until the mixture of all materials in the hot mixing tank is heated to 110°C by friction heating, and then the mixture is stopped to obtain the hot mix.

[0110] Cold mixing: Add the hot mix to the cold mixing tank and continue mixing at a stirring speed of 900 r / min. Use cooling water at 0-20℃ to cool the cold mixing tank until the temperature of the hot mix in the cold mixing tank drops to 55℃, then stop mixing to obtain the cold mix.

[0111] Plasticizing: The cold mixture is added to a twin-screw extruder and plasticized and mixed at 145°C for 8 minutes to obtain a plasticized material;

[0112] Granulation: Plasticized material is added to a single screw extruder and extruded and granulated at 140°C to obtain plastic granules;

[0113] Cooling: After the plastic granules are cooled by air cooling, they can be packaged and stored to obtain PVC cable sheath material products.

[0114] Preparation Example 5

[0115] Ingredients: PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, and lubricant were weighed according to Preparation Example 5 in Table 1. The PVC resin was a mixture of three PVC resins with degrees of polymerization of 1000, 1300, and 2500 in a weight ratio of 1:2:5. The cold-resistant rubber was a mixture of liquid nitrile rubber and liquid chlorinated rubber in a weight ratio of 1:1.25. The cold-resistant plasticizer was a mixture of dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester in a weight ratio of 1:1.25:1.25. The composition includes: filler: calcined kaolin; flame retardant: a mixture of zinc borate, antimony trioxide, and chlorinated paraffin in a weight ratio of 4:4:5; heat stabilizer: calcium-zinc composite heat stabilizer; antioxidant: bisphenol A (bisphenol A propane); lubricant: a mixture of EBS (ethylene bis-stearamide) and calcium stearate in a weight ratio of 1:1; and dioctyl terephthalate (DOTP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester added to an oil storage tank and stirred at 65°C for 20 minutes to obtain an oil. Cold-resistant rubber, flame retardant, antioxidant, and lubricant are then mixed to obtain a smaller mixture.

[0116] Hot mixing: PVC resin, filler, heat stabilizer, oil, and other small ingredients are added to a hot mixing tank in sequence and stirred at a high speed of 600 r / min until the mixture of all materials in the hot mixing tank is heated to 115°C by friction heating, and then the mixture is stopped to obtain the hot mix.

[0117] Cold mixing: Add the hot mix to the cold mixing tank and continue mixing at a stirring speed of 500 r / min. Use cooling water at 0-20℃ to cool the cold mixing tank until the temperature of the hot mix in the cold mixing tank drops to 60℃, then stop mixing to obtain the cold mix.

[0118] Plasticizing: The cold mixture is added to a twin-screw extruder and plasticized and mixed at 160°C for 10 minutes to obtain a plasticized material;

[0119] Granulation: Plasticized material is added to a single screw extruder and extruded and granulated at 150°C to obtain plastic granules;

[0120] Cooling: After the plastic granules are cooled by air cooling, they can be packaged and stored to obtain PVC cable sheath material products.

[0121] The PVC cable sheath materials prepared in Examples 1 to 5 above were taken and subjected to cold resistance tests according to the requirements of GB / T5470 and GB / T8815-2008 standards, flame retardancy tests according to the requirements of GB / T2406 and GB / T8815-2008 standards, and tensile strength and other machinability tests according to the requirements of GB / T1040.3 and GB / T8815-2008 standards. The test results are shown in Table 2.

[0122] Table 2. Test Results

[0123]

[0124] Table 2 shows that the low-temperature embrittlement performance of the PVC cable sheath materials prepared in Examples 1-5 is between -40℃ and -45℃, and the oxygen index is between 28% and 35%. This indicates excellent cold resistance and flame retardancy, fully meeting the requirements for cable sheathing in extremely cold environments of -40℃ and below. Furthermore, the tensile strength is ≥16.5 MPa, the tensile strain at break is ≥280%, the maximum change rate of tensile strength after aging at 100℃ for 168 hours is 5%–12%, the maximum change rate of tensile strain at break after aging at 100℃ for 168 hours is -10%–-17%, the heat deformation is ≤40%, the thermal stability time at 200℃ is ≥90 min, and the mass loss after aging at 100℃ for 168 hours is ≤14.9 g / m³. 2 It meets the requirements of GB / T1040.3 and GB / T8815-2008 standards and has excellent machinability.

[0125] Example 3

[0126] This embodiment discloses a cold-resistant and flame-retardant cable, which includes a sheath. The sheath is made of the PVC cable sheath material described in Embodiment 1, or of the PVC cable sheath material prepared by the PVC cable sheath material preparation method described in Embodiment 2.

[0127] The cold-resistant and flame-retardant cable of this embodiment can be used in extremely cold environments of -40℃ and below.

[0128] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A PVC cable sheath material, characterized in that, The components include the following parts by weight: 100 parts of PVC resin; 26-40 parts of cold-resistant rubber; 45-53 parts of cold-resistant plasticizer; 45-52 parts of filler; 10-26 parts flame retardant; Heat stabilizer 9-15 parts; Antioxidant 0.5–1.2 parts; 2.0 to 3.5 parts of lubricant; Colorant 0-1.2 parts; The cold-resistant rubber is a combination of liquid nitrile rubber and liquid chlorinated rubber, wherein the weight ratio of the liquid nitrile rubber to the liquid chlorinated rubber is 1:(1~1.5). The cold-resistant plasticizer is a combination of two or more of the following: dioctyl terephthalate (DOTP), diisodecyl phthalate (DIDP), dioctyl sebacate (DOS), and triethylene glycol diisodecyl ester. The flame retardant is a combination of zinc borate, antimony trioxide, and chlorinated paraffin, wherein the weight ratio of zinc borate, antimony trioxide, and chlorinated paraffin is (1-4):(1-4):(1-5). The PVC cable sheath material has a low temperature resistance of -40℃ to -45℃ and an oxygen index of 28% to 35%.

2. The PVC cable sheath material according to claim 1, characterized in that, The degree of polymerization of the PVC resin is one or more of 1000, 1300, and 2500.

3. The PVC cable sheath material according to claim 2, characterized in that, When there is a combination of multiple types, the weight ratio of PVC resins with a degree of polymerization of 1000, 1300, and 2500 in the PVC resin is 1:(1-2):(5-7).

4. The PVC cable sheath material according to claim 1, characterized in that, The filler is one of light calcium carbonate, heavy calcium carbonate, and calcined kaolin.

5. The PVC cable sheath material according to claim 1, characterized in that, The heat stabilizer is one or a combination of two of the following: calcium-zinc composite heat stabilizer and rare earth calcium-zinc composite heat stabilizer.

6. The PVC cable sheath material according to claim 5, characterized in that, When it is a combination of two, the weight ratio of the calcium-zinc composite heat stabilizer and the rare earth calcium-zinc composite heat stabilizer in the heat stabilizer is (1-4):(1-5).

7. The PVC cable sheath material according to claim 1, characterized in that, The antioxidant is bisphenol A.

8. The PVC cable sheath material according to claim 1, characterized in that, The lubricant is any combination of two or three of the following: polyethylene wax, ethylene bis-stearamide (EBS), calcium stearate, and barium stearate.

9. The PVC cable sheath material according to claim 1, characterized in that, The colorant is a black masterbatch.

10. A method for preparing a PVC cable sheath material, comprising: Ingredients: The PVC cable sheath material according to any one of claims 1 to 9 is made by weighing PVC resin, cold-resistant rubber, cold-resistant plasticizer, filler, flame retardant, heat stabilizer, antioxidant, lubricant, and colorant, and is divided into main material, oil and minor materials; Hot mixing: The main ingredient, the oil, and the minor ingredients are added to a hot mixing tank in sequence and mechanically stirred until the main ingredient, oil, and minor ingredients are mixed and heated to 95-115°C by friction to obtain a hot mixture. Cold mixing: The hot mixture is added to a cold mixing tank and stirred and mixed, and then cooled until the hot mixture is cooled to 40-60°C to obtain a cold mixture; Plasticizing: The cold mixture is added to a twin-screw extruder and then heated and plasticized to obtain a plasticized material. Granulation: The plasticized material is added to a single screw extruder for granulation to obtain plastic granules; Cooling: After cooling the plastic granules, PVC cable sheath material is obtained.

11. The method for preparing PVC cable sheath material according to claim 10, characterized in that, The main ingredients include PVC resin, fillers, and heat stabilizers; The oil contains a cold-resistant plasticizer, and the method further includes stirring the cold-resistant plasticizer at 25–65°C for 20–35 min before adding the oil to the hot mixing tank; The minor components include cold-resistant rubber, flame retardant, antioxidant, lubricant, and colorant.

12. The method for preparing PVC cable sheath material according to claim 10, characterized in that, In the hot mixing step, the stirring speed is 475–950 r / min.

13. The method for preparing PVC cable sheath material according to claim 10, characterized in that, In the cold mixing step, the cooling process uses cooling water at 0-20℃.

14. The method for preparing PVC cable sheath material according to claim 10, characterized in that, The temperature for plasticizing and mixing is 100–160°C, and the temperature for extrusion granulation is 100–160°C.

15. A cold-resistant and flame-retardant cable, comprising a sheath, characterized in that, The sheath is made of the PVC cable sheath material as described in any one of claims 1 to 9.

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