CN118146598A - Oil-resistant polyvinyl chloride cable - Google Patents

Abstract

The invention relates to the technical field of cables, in particular to an oil-resistant polyvinyl chloride cable. The oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials: polyvinyl chloride, carboxyl butyl rubber or modified nitrile rubber, styrene elastomer, aniline formaldehyde resin, vinyl trimethoxy silane, antioxidant, vulcanizing agent, maleic anhydride-styrene copolymer, zinc stearate, dioctyl sebacate, liquid paraffin, white carbon black and zinc oxide. According to the invention, the modified nitrile rubber is added into the sheath layer, so that the problems of poor oil resistance, poor wear resistance and poor mechanical properties of the polyvinyl chloride cable are effectively solved, the strength and toughness of the oil-resistant polyvinyl chloride cable are effectively improved, and the oil resistance and wear resistance are also improved.

Description

Oil-resistant polyvinyl chloride cable

Technical Field

The invention relates to the technical field of cables, and in particular to an oil-resistant polyvinyl chloride cable.

Background technique

Polyvinyl chloride has good insulation properties, mechanical properties and processing properties, and is widely used as insulation material and sheath material for wires and cables. However, polyvinyl chloride has a large hardness. In order to prepare polyvinyl chloride soft plastic for wires and cables, plasticizers are usually added to polyvinyl chloride to improve its plasticity and ensure that polyvinyl chloride plastic has a certain degree of softness. Polyvinyl chloride is a modified material obtained by chlorination of polyvinyl chloride, and its chlorine content is higher than that of polyvinyl chloride resin, generally more than 65%. The increase in chlorine content enhances polarity and gives it a series of excellent properties. Compared with polyvinyl chloride, it has high strength, heat resistance, corrosion resistance, small thermal expansion coefficient, flame retardancy, and low oxygen permeability. It is used for high-voltage and ultra-high voltage cable laying casings, and can meet the requirements of heat resistance, flame retardancy, pressure resistance, construction, etc. It is a material with excellent performance. However, polyvinyl chloride is difficult to plasticize, and the impact strength of the finished product is low. When used in power cable casings, especially large-diameter power cable casings, it is necessary to modify the polyvinyl chloride material according to specific technical requirements such as its processability and impact performance.

Chinese invention patent CN116814021B discloses a high-strength wear-resistant cable, which consists of a bundled core and a wear-resistant sheath, wherein the wear-resistant sheath includes, by weight: 100 parts of polyvinyl chloride resin, 15-25 parts of high-density polyethylene, 8-12 parts of ethylene-octene copolymer, 10-15 parts of temperature-resistant enhancer, 7-11 parts of wear-resistant filler, 3-5 parts of lubricant, 5-8 parts of toughening agent and 0.2-0.3 parts of antioxidant. Although the invention effectively solves the wear resistance of the cable, the oil resistance of the cable in the invention is poor, and the mechanical strength needs to be improved.

Summary of the invention

In view of the deficiencies in mechanical strength and oil resistance of cable materials in the above-mentioned prior art, the present invention provides an oil-resistant polyvinyl chloride cable.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

An oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials: polyvinyl chloride, carboxybutyl rubber or modified nitrile rubber, styrene elastomer, aniline formaldehyde resin, vinyl trimethoxy silane, antioxidant, vulcanizing agent, maleic anhydride-styrene copolymer, zinc stearate, dioctyl sebacate, liquid paraffin, white carbon black and zinc oxide.

Preferably, the oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, and the sheath layer is composed of the following raw materials in parts by weight: 60-120 parts of polyvinyl chloride, 15-30 parts of carboxybutyl rubber or modified nitrile rubber, 10-30 parts of styrene elastomer, 5-12 parts of aniline formaldehyde resin, 5-12 parts of vinyl trimethoxy silane, 2-4 parts of antioxidant, 1-3 parts of vulcanizing agent, 5-12 parts of maleic anhydride-styrene copolymer, 1-3 parts of zinc stearate, 2-5 parts of dioctyl sebacate, 5-10 parts of liquid paraffin, 5-15 parts of white carbon black and 10-30 parts of zinc oxide.

The conductor is any one of copper, zinc and iron.

The vulcanizing agent is any one of di-tert-butyl peroxyisopropylbenzene, diisopropylbenzene peroxide and tert-butylphenol formaldehyde resin.

The antioxidant is any one of antioxidant 1010, antioxidant 168, antioxidant 1080, and antioxidant 1076.

Since polyvinyl chloride is difficult to plasticize, the finished product has low impact strength, poor toughness and poor oil resistance. When used in power cable sheaths, especially oil-resistant cable sheaths, it has a short service life due to its poor oil resistance, processability and impact performance. It is also easy to cause defects such as cracking in cables during storage and use.

The molecular structure of nitrile rubber has unsaturated double bonds and cyano groups, so it has the advantages of good oil resistance, good wear resistance and strong adhesion, and is widely used in the manufacture of various oil-resistant rubber products. The polarity of carboxyl nitrile rubber is relatively high, which increases the compatibility with polar materials such as polyvinyl chloride and matrix, and further improves the oil resistance; at the same time, the introduction of carboxyl groups also improves the tensile strength of the material, especially the tensile strength at high temperatures. The present invention aims to add carboxyl nitrile rubber with oil resistance, wear resistance and strong adhesion, which can improve the compatibility of nitrile rubber with the raw material matrix, and can improve the oil resistance of polyvinyl chloride cable materials to a certain extent. Although carboxyl nitrile rubber performs well in oil resistance, it may not have good plasticity and elasticity like polyvinyl chloride in some aspects, which may affect the flexibility and durability of the cable during installation and use.

The preparation method of the carboxylated nitrile rubber is as follows: 60-120 parts by weight of water, 1-3 parts by weight of alkylphenol polyoxyethylene polyoxypropylene ether, 10-25 parts by weight of acrylonitrile, 10-25 parts by weight of methacrylic acid, 0.1-0.3 parts by weight of ethylenediaminetetraacetic acid tetrasodium salt, 2-5 parts by weight of n-dodecyl tertiary mercaptan, and 2-5 parts by weight of sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred at 200-600 rpm and 40-50° C. for 20-40 minutes, then 20-40 parts by weight of butadiene and 0.5-2 parts by weight of azobisisobutyronitrile are added, the reaction is continued for 40-80 minutes, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain the carboxylated nitrile rubber.

Due to the characteristics of carboxylated nitrile rubber such as inability to crystallize and small intermolecular force of rubber, many of its properties are relatively poor, especially oil resistance and dimensional stability. The working life of cable materials made with it as the basic material will be greatly shortened. Therefore, the present invention further modifies the carboxylated nitrile rubber and cooperates with the interaction of nanofillers to greatly improve the performance of polyvinyl chloride cable materials, especially oil resistance, wear resistance and mechanical properties, thereby significantly improving the working life of the cable.

The invention further modifies the carboxylated nitrile rubber, wherein 2-(methacrylate)ethyl 3,5-diaminobenzoic acid and 2-methoxy-4-vinylphenol are reacted to obtain a supramolecular polymer as a modifier, wherein the supramolecular polymer includes a polymer formed based on multiple intermolecular interactions and their synergistic or multiple effects, and an amino group and a hydroxyl group in the supramolecular polymer react with a carboxylated nitrile rubber carboxyl group, and the carboxyl group condenses with the amino group or the hydroxyl group to form an amide bond or an ester group to obtain a modified nitrile rubber. When the modified carboxylated nitrile rubber is stretched under stress, hydrogen bonds between the hydroxyl group and the amino group of the supramolecular polymer itself and hydrogen bonds between the supramolecular polymer and the carboxylated nitrile rubber break and dissipate energy before covalent bonds break, and the breaking of hydrogen bonds prevents the covalently cross-linked carboxylated nitrile rubber from being destroyed prematurely due to stress concentration, thereby significantly improving the strength and toughness of the carboxylated nitrile rubber, and also improving the oil resistance and wear resistance.

Preferably, the preparation method of the modified nitrile rubber is as follows:

S1: 2-(methacrylate)ethyl 3,5-diaminobenzoic acid, 2-methoxy-4-vinylphenol and N,N-dimethylformamide are mixed and stirred, and butyltriphenylphosphine bromide and toluenesulfonyl hydrazide are added to react to obtain an intermediate;

S2: The intermediate, water, alkylphenol polyoxyethylene polyoxypropylene ether, acrylonitrile, organic acid, tetrasodium ethylenediaminetetraacetic acid, n-dodecyl tertiary mercaptan, and sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred, butadiene and azobisisobutyronitrile are added to continue the reaction, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain modified nitrile rubber.

Further, the preparation method of the modified nitrile rubber is as follows:

S1: 3-5 parts by weight of 2-(methacrylate)ethyl 3,5-diaminobenzoic acid, 5-10 parts by weight of 2-methoxy-4-vinylphenol and 70-130 parts by weight of N,N-dimethylformamide are mixed, stirred at 400-800 rpm for 8-15 min, 5-10 parts by weight of butyltriphenylphosphonium bromide and 4-6 parts by weight of toluenesulfonylhydrazide are added, reacted at 40-50° C. for 5-8 h, and the solvent is removed by distillation under reduced pressure to obtain an intermediate;

S2: 4-6 parts by weight of the intermediate, 60-120 parts by weight of water, 1-3 parts by weight of alkylphenol polyoxyethylene polyoxypropylene ether, 10-25 parts by weight of acrylonitrile, 10-25 parts by weight of methacrylic acid, 0.1-0.3 parts by weight of ethylenediaminetetraacetic acid tetrasodium salt, 2-5 parts by weight of n-dodecyl tertiary mercaptan, and 2-5 parts by weight of sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred at 200-600rpm and 40-50°C for 20-40min, then 20-40 parts by weight of butadiene and 0.5-2 parts by weight of azobisisobutyronitrile are added, the reaction is continued for 40-80min, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain a modified nitrile rubber.

The organic acid is at least one of 2-ethylacrylic acid, methacrylic acid and acrylic acid.

The oil-resistant polyvinyl chloride cable is prepared by the following method: 60-120 parts of polyvinyl chloride, 15-30 parts of carboxybutyl rubber or modified nitrile rubber, 10-30 parts of styrene elastomer, 5-12 parts of aniline formaldehyde resin, 5-12 parts of vinyl trimethoxysilane, 2-4 parts of antioxidant, 1-3 parts of vulcanizing agent, 5-12 parts of maleic anhydride-styrene copolymer, 1-3 parts of zinc stearate, 2-5 parts of dioctyl sebacate, 5-10 parts of liquid paraffin, 5-15 parts of white carbon black and 10-30 parts of zinc oxide are mixed and stirred, kneaded at 120-150° C. for 8-15 minutes, extruded and formed, and coated on the surface of the conductor to obtain the oil-resistant polyvinyl chloride cable.

Beneficial Effects of the Invention

1. The present invention provides an oil-resistant polyvinyl chloride cable, which effectively overcomes the defects of polyvinyl chloride being difficult to plasticize, having low impact strength, poor toughness, and poor oil resistance of the finished product through the interaction between various substances, expands the application in power cable sheaths, especially in oil-resistant cable sheaths, and effectively reduces defects such as cracking of cables during storage and use.

2. The present invention further modifies the carboxylated nitrile rubber and cooperates with the interaction of nanofillers to greatly improve the performance of polyvinyl chloride cable materials, especially the oil resistance, wear resistance and mechanical properties, thereby significantly improving the service life of the cable.

3. The present invention provides a method for preparing a modified nitrile rubber, wherein a supramolecular polymer is obtained as a modifier by reacting 2-(methacrylate)ethyl 3,5-diaminobenzoic acid and 2-methoxy-4-vinylphenol, and an amino group and a hydroxyl group in the supramolecular polymer are reacted with a carboxyl group of a carboxyl nitrile rubber, and the carboxyl group condenses with the amino group or the hydroxyl group to form an amide bond or an ester group to obtain a modified nitrile rubber. When the modified carboxyl nitrile rubber is stretched, hydrogen bonds between the hydroxyl group and the amino group of the supramolecular polymer itself and hydrogen bonds between the supramolecular polymer and the carboxyl nitrile rubber break and dissipate energy before covalent bonds break. The breaking of hydrogen bonds prevents the covalently cross-linked carboxyl nitrile rubber from being destroyed prematurely due to stress concentration, thereby significantly improving the strength and toughness of the carboxyl nitrile rubber, and also improving the oil resistance and wear resistance.

Detailed ways

The above content of the present invention is further described in detail below in conjunction with specific implementation modes, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments.

Introduction of some raw materials in this application:

Polyvinyl chloride was purchased from Hengtai Plastic Raw Materials Business Department in Zhangmutou, Dongguan City, with the brand name DMDA-8008.

Commercially available nitrile rubber was purchased from Hengshui Lier Technology Co., Ltd., with the brand name FGGF43.

Styrene elastomer was purchased from Guangdong Dingxin Polymer Technology Co., Ltd., brand D-1161JSP.

Aniline formaldehyde resin was purchased from Dongguan Taiyang New Material Technology Co., Ltd., model TY-8912.

Alkylphenol polyoxyethylene polyoxypropylene ether was purchased from Nantong Aochen Chemical Co., Ltd., model NPE-108.

Example 1

An oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials in parts by weight: 80 parts of polyvinyl chloride, 20 parts of nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropyl benzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide.

The nitrile rubber is commercially available nitrile rubber.

The conductor is copper.

The oil-resistant polyvinyl chloride cable is prepared by the following method: 80 parts of polyvinyl chloride, 20 parts of nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropylbenzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide are mixed and stirred, kneaded at 135° C. for 10 minutes, extruded and formed, and coated on the surface of the conductor to obtain the oil-resistant polyvinyl chloride cable.

Example 2

An oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials in parts by weight: 80 parts of polyvinyl chloride, 20 parts of carboxylated nitrile rubber, 20 parts of styrene-based elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropyl benzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide.

The preparation method of the carboxylated nitrile rubber is as follows: 70 parts by weight of water, 2 parts by weight of alkylphenol polyoxyethylene polyoxypropylene ether, 15 parts by weight of acrylonitrile, 20 parts by weight of methacrylic acid, 0.15 parts by weight of ethylenediaminetetraacetic acid tetrasodium salt, 3.5 parts by weight of n-dodecyl tertiary mercaptan, and 2.5 parts by weight of sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized and replaced with nitrogen three times, stirred at 400 rpm and 45° C. for 30 minutes, then 30 parts by weight of butadiene and 1 part by weight of azobisisobutyronitrile are added, the reaction is continued for 50 minutes, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain the carboxylated nitrile rubber.

The conductor is copper.

The oil-resistant polyvinyl chloride cable is prepared by the following method: 80 parts of polyvinyl chloride, 20 parts of carboxyl nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropylbenzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide are mixed and stirred, kneaded at 135° C. for 10 minutes, extruded and formed, and coated on the surface of the conductor to obtain the oil-resistant polyvinyl chloride cable.

Example 3

An oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials in parts by weight: 80 parts of polyvinyl chloride, 20 parts of modified nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 3 parts of antioxidant 1010, 2 parts of di-tert-butyl peroxy isopropyl benzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide.

The preparation method of the modified nitrile rubber is as follows:

S1: 4 parts by weight of 2-(methacrylate)ethyl 3,5-diaminobenzoic acid, 8 parts by weight of 2-methoxy-4-vinylphenol and 80 parts by weight of N,N-dimethylformamide were mixed, stirred at 600 rpm for 10 min, 8 parts by weight of butyltriphenylphosphonium bromide and 6 parts by weight of toluenesulfonylhydrazide were added, reacted at 45° C. for 6 h, and the solvent was removed by distillation under reduced pressure to obtain an intermediate;

S2: 4.5 parts by weight of the intermediate, 70 parts by weight of water, 2 parts by weight of alkylphenol polyoxyethylene polyoxypropylene ether, 15 parts by weight of acrylonitrile, 20 parts by weight of methacrylic acid, 0.15 parts by weight of tetrasodium ethylenediaminetetraacetic acid, 3.5 parts by weight of n-dodecyl tertiary mercaptan, and 2.5 parts by weight of sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred at 400 rpm and 45° C. for 30 minutes, then 30 parts by weight of butadiene and 1 part by weight of azobisisobutyronitrile are added, the reaction is continued for 50 minutes, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain a modified nitrile rubber.

The conductor is copper.

The oil-resistant polyvinyl chloride cable is prepared by the following method: 80 parts of polyvinyl chloride, 20 parts of modified nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropylbenzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide are mixed and stirred, kneaded at 135° C. for 10 minutes, extruded and formed, and coated on the surface of the conductor to obtain the oil-resistant polyvinyl chloride cable.

Example 4

An oil-resistant polyvinyl chloride cable comprises a conductor and a sheath layer, wherein the sheath layer is composed of the following raw materials in parts by weight: 80 parts of polyvinyl chloride, 20 parts of modified nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropyl benzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide.

The preparation method of the modified nitrile rubber is as follows:

S1: 4 parts by weight of 2-(methacrylate)ethyl 3,5-diaminobenzoic acid, 8 parts by weight of 2-methoxy-4-vinylphenol and 80 parts by weight of N,N-dimethylformamide were mixed, stirred at 600 rpm for 10 min, 8 parts by weight of butyltriphenylphosphonium bromide and 6 parts by weight of toluenesulfonylhydrazide were added, reacted at 45° C. for 6 h, and the solvent was removed by distillation under reduced pressure to obtain an intermediate;

S2: 4.5 parts by weight of the intermediate, 70 parts by weight of water, 2 parts by weight of alkylphenol polyoxyethylene polyoxypropylene ether, 15 parts by weight of acrylonitrile, 0.15 parts by weight of tetrasodium ethylenediaminetetraacetic acid, 3.5 parts by weight of n-dodecyl tertiary mercaptan, and 2.5 parts by weight of sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized and replaced with nitrogen three times, stirred at 400 rpm and 45° C. for 30 minutes, then 30 parts by weight of butadiene and 1 part by weight of azobisisobutyronitrile are added, the reaction is continued for 50 minutes, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain a modified nitrile rubber.

The conductor is copper.

The oil-resistant polyvinyl chloride cable is prepared by the following method: 80 parts of polyvinyl chloride, 20 parts of modified nitrile rubber, 20 parts of styrene elastomer, 10 parts of aniline formaldehyde resin, 8 parts of vinyl trimethoxy silane, 10103 parts of antioxidant, 2 parts of di-tert-butyl peroxy isopropylbenzene, 10 parts of maleic anhydride-styrene copolymer, 2 parts of zinc stearate, 3 parts of dioctyl sebacate, 7 parts of liquid paraffin, 10 parts of white carbon black and 20 parts of zinc oxide are mixed and stirred, kneaded at 135° C. for 10 minutes, extruded and formed, and coated on the surface of the conductor to obtain the oil-resistant polyvinyl chloride cable.

Test Example 1

Wear performance test: The oil-resistant polyvinyl chloride cables prepared in Examples 1-4 were tested using the national standard GB/T3960-2016 "Plastic Sliding Friction Wear Test Method". The lower the wear rate, the better the wear resistance. Five parallel samples were set in each group, and the average value was taken. The results are shown in Table 1.

Table 1 Wear performance test results

Wear rate,% Example 1 0.57 Example 2 0.48 Example 3 0.12 Example 4 0.29

Test Example 2

Oil resistance test: The national standard GB/T1690-2010 "Test method for liquid resistance of vulcanized rubber or thermoplastic rubber" was used for testing. The oil-resistant polyvinyl chloride cable material in Example 1-4 was injection molded by an injection molding machine. The sample was type I, the sample size was 25mm*50mm*2mm, and the oil was liquid B (30% toluene, 70% isooctane). It was immersed for 168h at a temperature of 23°C, and the mass change rate, tensile strength and elongation at break were tested. Five parallel samples were set in each group, and the average value was taken. The results are shown in Table 2.

Table 2 Mechanical properties test results

From the above results, it can be seen that the oil-resistant polyvinyl chloride cable prepared by the present invention has good oil resistance, wear resistance and mechanical properties. From Examples 1-2, it can be seen that the polarity of the carboxyl nitrile rubber is relatively high, which increases the compatibility with polar materials such as polyvinyl chloride and matrix, and further improves the oil resistance; at the same time, the introduction of carboxyl groups also improves the tensile strength of the material, especially the tensile strength at high temperatures, which can effectively improve the flexibility and durability of the cable during installation and use.

It can be seen from Examples 2-4 that the present invention further modifies the carboxylated nitrile rubber and cooperates with the interaction of nanofillers to greatly improve the performance of the polyvinyl chloride cable material, especially the oil resistance, wear resistance and mechanical properties, thereby significantly increasing the service life of the cable. The reason is that 2-(methacrylate)ethyl 3,5-diaminobenzoic acid and 2-methoxy-4-vinylphenol are reacted to obtain a supramolecular polymer as a modifier. The supramolecular polymer includes polymers formed based on multiple intermolecular interactions and their synergistic or multiple effects. The amino group and hydroxyl group in the supramolecular polymer react with the carboxyl group of carboxyl nitrile rubber. The carboxyl group condenses with the amino group or the hydroxyl group to form an amide bond or an ester group to obtain a modified nitrile rubber. When the modified carboxyl nitrile rubber is stretched, the hydrogen bonds between the hydroxyl group and the amino group of the supramolecular polymer itself and the hydrogen bonds between the supramolecular polymer and the carboxyl nitrile rubber break before the covalent bonds break to dissipate energy. The breaking of the hydrogen bonds will prevent the covalently cross-linked carboxyl nitrile rubber from being destroyed prematurely due to stress concentration, thereby significantly improving the strength and toughness of the carboxyl nitrile rubber, while also improving the oil resistance and wear resistance.

Claims (8)

1. An oil-resistant polyvinyl chloride cable, comprising a conductor and a sheath layer, characterized in that the sheath layer is composed of the following raw materials: polyvinyl chloride, carboxybutyl rubber or modified nitrile rubber, styrene elastomer, aniline formaldehyde resin, vinyl trimethoxy silane, antioxidant, vulcanizing agent, maleic anhydride-styrene copolymer, zinc stearate, dioctyl sebacate, liquid paraffin, white carbon black and zinc oxide. 2. The oil-resistant polyvinyl chloride cable according to claim 1, characterized in that the vulcanizing agent is any one of di-tert-butyl peroxyisopropylbenzene, diisopropylbenzene peroxide, and tert-butylphenol formaldehyde resin. 3. The oil-resistant polyvinyl chloride cable according to claim 1 is characterized in that the antioxidant is any one of antioxidant 1010, antioxidant 168, antioxidant 1080, and antioxidant 1076. 4. The oil-resistant polyvinyl chloride cable according to claim 1, characterized in that the conductor is any one of copper, zinc and iron. 5. The oil-resistant polyvinyl chloride cable as claimed in claim 1 is characterized in that the preparation method of the carboxylated nitrile rubber is as follows: water, alkylphenol polyoxyethylene polyoxypropylene ether, acrylonitrile, organic acid, tetrasodium salt of ethylenediaminetetraacetic acid, n-dodecyl tertiary mercaptan, and sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred, butadiene and azobisisobutyronitrile are added to continue the reaction, cooled to room temperature, and the solvent is removed by reduced pressure distillation, washed, and dried to obtain the carboxylated nitrile rubber. 6. The oil-resistant polyvinyl chloride cable according to claim 1, characterized in that the preparation method of the modified nitrile rubber is as follows: S1: 2-(methacrylate)ethyl 3,5-diaminobenzoic acid, 2-methoxy-4-vinylphenol and N,N-dimethylformamide are mixed and stirred, and butyltriphenylphosphine bromide and toluenesulfonyl hydrazide are added to react to obtain an intermediate; S2: The intermediate, water, alkylphenol polyoxyethylene polyoxypropylene ether, acrylonitrile, organic acid, tetrasodium ethylenediaminetetraacetic acid, n-dodecyl tertiary mercaptan, and sodium dodecyl diphenyl ether disulfonate are mixed, vacuumized, replaced with nitrogen three times, stirred, butadiene and azobisisobutyronitrile are added to continue the reaction, cooled to room temperature, the solvent is removed by reduced pressure distillation, washed, and dried to obtain modified nitrile rubber. 7. The oil-resistant polyvinyl chloride cable according to claim 5 or 6, characterized in that the organic acid is at least one of 2-ethylacrylic acid, methacrylic acid and acrylic acid. 8. The method for preparing an oil-resistant polyvinyl chloride cable according to any one of claims 1 to 7, characterized in that polyvinyl chloride, carboxybutyl rubber or modified nitrile rubber, styrene-based elastomer, aniline formaldehyde resin, vinyl trimethoxy silane, antioxidant, vulcanizing agent, maleic anhydride-styrene copolymer, zinc stearate, dioctyl sebacate, liquid paraffin, white carbon black and zinc oxide are mixed and stirred, kneaded and extruded, and coated on the surface of a conductor to obtain an oil-resistant polyvinyl chloride cable.