Corrosion-resistant wear-resistant control cable and preparation method and application thereof

Abstract

The application belongs to the technical field of cables, and relates to a corrosion-resistant and wear-resistant control cable as well as a preparation method and application thereof. The corrosion-resistant and wear-resistant control cable comprises, from inside to outside, a conductor, an insulation layer, a shielding layer, an inner sheath layer and a composite outer sheath layer. The composite outer sheath layer comprises a base layer and a functional modified filler dispersed in the base layer. The functional modified filler is a composite particle of a hydroxyl modified diatomite loaded with a composite corrosion inhibitor. The hydroxyl modified diatomite is diatomite modified and treated with phytic acid and silane coupling agent KH-560 in sequence. The composite corrosion inhibitor comprises a complex of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether. The corrosion-resistant and wear-resistant control cable can improve the corrosion resistance, wear resistance and tensile strength of the control cable under complex working conditions.

Description

Technical Field

[0001] This invention belongs to the field of cable technology and relates to a corrosion-resistant and wear-resistant control cable, its preparation method and application. Background Technology

[0002] When control cables are used in complex environments such as petrochemical, mining machinery, marine engineering, and rail transportation, corrosion resistance, abrasion resistance, and tensile strength are key indicators determining their service life and reliability. In corrosive environments, the sheath layer needs to effectively block or slow down the intrusion of corrosive media; under abrasive wear and repeated bending conditions, the sheath layer needs to have good abrasion resistance and mechanical strength; and the cable also needs to withstand continuous tensile and bending stresses during installation and long-term operation. How to simultaneously improve these three properties has been a long-standing technical challenge in this field.

[0003] In existing technologies, some researchers have proposed blending two polyvinyl chloride resins with different degrees of polymerization to improve material density and slow down the penetration of corrosive media. However, this passive barrier method has limited effectiveness. Once the sheath layer develops microcracks due to wear or bending, corrosive media can still penetrate along the cracks, eroding the shielding layer and conductor. This approach also adds molybdenum disulfide as a lubricating filler to reduce friction; however, molybdenum disulfide has weak bonding with polar resins such as PVC and is prone to detachment during long-term use, which actually exacerbates wear. Although caprolactam is used to improve compatibility, physical blending makes it difficult to form strong chemical bonds, and the problem of interfacial debonding is not fundamentally solved. The debonding points become stress concentration points, leading to a decrease in tensile strength, and also become preferential channels for corrosive media. In addition, some solutions use MQ silicone resin and vinyl chloride-vinyl acetate copolymer to improve high temperature resistance and use hydroxyl biphenyl compound composite bauxite to enhance tensile strength. However, this solution is mainly for high temperature environments and does not consider the performance degradation under corrosion and wear conditions. Moreover, the addition of hard fillers such as bauxite will destroy the compactness of the matrix and further reduce the corrosion resistance.

[0004] In summary, existing technologies suffer from three main problems: First, it is difficult to simultaneously improve corrosion resistance, abrasion resistance, and tensile strength; improving one often comes at the expense of another. Second, directly adding corrosion inhibitors can lead to migration and precipitation, resulting in poor compatibility with the matrix, insufficient long-term effectiveness, and potential reduction in tensile strength. Third, the inorganic filler and polymer matrix are mainly bonded by physical adsorption or weak hydrogen bonds, which can easily debond during processing or use, leading to a decline in mechanical properties. Furthermore, the debonding interface becomes a penetration path for corrosive media. Therefore, there is a need to develop a control cable that can simultaneously improve corrosion resistance, abrasion resistance, and tensile strength. Summary of the Invention

[0005] This invention proposes a corrosion-resistant and wear-resistant control cable, its preparation method, and its application, aiming to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] On one hand, the present invention provides a corrosion-resistant and wear-resistant control cable, which comprises, from the inside out, a conductor, an insulation layer, a shielding layer, an inner sheath layer, and a composite outer sheath layer; The composite outer sheath layer includes a matrix layer and functional modified fillers dispersed in the matrix layer; The functional modified filler is a composite particle of hydroxyl-modified diatomaceous earth loaded with a composite corrosion inhibitor (the composite corrosion inhibitor is loaded in the pores of hydroxyl-modified diatomaceous earth). The preparation method of the functional modified filler is as follows: hydroxyl-modified diatomaceous earth and composite corrosion inhibitor are ultrasonically dispersed in anhydrous ethanol for 30-60 min and vacuum dried at 60-80 ℃ for 12-24 h to obtain the filler. The hydroxyl-modified diatomaceous earth is diatomaceous earth that has been successively modified by phytic acid and silane coupling agent KH-560 (phytic acid first reacts with the silanol groups on the surface of the diatomaceous earth to form a phosphate ester anchoring layer, and silane coupling agent KH-560 then reacts with the remaining silanol groups and the phosphate groups of phytic acid to form an epoxy functionalized surface). The composite corrosion inhibitor comprises a compound of molybdate, benzotriazole, and fatty acid methyl ester polyoxyethylene ether.

[0008] Preferably, by weight, the composite outer sheath layer comprises: 100 parts of matrix layer and 9.5 to 18.5 parts of functional modified filler; In the functional modified filler, the weight ratio of hydroxyl-modified diatomaceous earth to composite corrosion inhibitor is 1:0.15~0.35.

[0009] Preferably, in the hydroxyl-modified diatomaceous earth, the weight ratio of diatomaceous earth, phytic acid, and silane coupling agent KH-560 is 100:2~5:1.5~3.

[0010] Preferably, in the composite corrosion inhibitor, the weight ratio of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether is 1:0.4~0.8:0.5~1.

[0011] It should be noted that if traditional corrosion inhibitors are added directly to improve corrosion resistance, small-molecule inhibitors, like plasticizers, will weaken the intermolecular forces, leading to a decrease in tensile strength. If solid lubricants such as molybdenum disulfide are added to improve wear resistance, their weak interfacial bonding with the matrix will become stress concentration points and corrosion channels, sacrificing both tensile strength and corrosion resistance. If rigid fillers are simply added to enhance tensile strength, filler agglomeration and interfacial debonding will reduce corrosion resistance and exacerbate abrasive wear. The reason why current technologies have long been unable to overcome the bottleneck of simultaneously improving corrosion resistance, wear resistance, and tensile strength lies in the inherent contradiction in the requirements of these three properties on the material's microstructure: corrosion resistance requires a dense matrix and defect-free interfaces; wear resistance requires surface lubrication and filler that is not easily detached; and tensile strength requires strong bonding between the filler and the matrix and efficient stress transfer. Traditional solutions attempt to satisfy all three simultaneously through single-component or simple physical blending, often resulting in compromises.

[0012] The composite corrosion inhibitor in this invention achieves controlled release through the physical confinement of diatomaceous earth pores, avoiding plasticizing damage to the mechanical properties of the matrix caused by small molecules. Its fatty acid methyl ester polyoxyethylene ether component provides in-situ lubrication while participating in the interfacial chemical bonding network together with molybdate and benzotriazole, unifying the two originally contradictory functions of lubrication and reinforcement at the same interface. Molybdate and benzotriazole are released and form a protective film under the triggering of corrosive media, thus making it possible to simultaneously improve corrosion resistance, wear resistance and tensile strength.

[0013] Preferably, the matrix layer is a blend matrix of polyvinyl chloride (PVC) and ethylene-vinyl acetate copolymer (EVA).

[0014] More preferably, the weight ratio of the polyvinyl chloride and the ethylene-vinyl acetate copolymer is 65~80:20~35.

[0015] Preferably, the molybdate is selected from one or more of sodium molybdate, ammonium molybdate, and calcium molybdate.

[0016] In this invention, a surface layer with a specific chemical structure and reactivity is formed on the diatomaceous earth surface after dual modification treatment with phytic acid and silane coupling agent KH-560. This surface layer performs three functions: First, the porous structure provides a stable physical loading space for the composite corrosion inhibitor, enabling the storage and long-term slow release of the corrosion inhibitor. This avoids the plasticizing damage to the mechanical properties of the matrix caused by the migration and precipitation of small molecules due to direct addition, while ensuring that the sheath layer continues to have active anti-corrosion capabilities during long-term service. Second, the epoxy groups introduced by KH-560 chemically bond with the active groups such as hydroxyl and carboxyl groups in the PVC / EVA matrix during melt blending, upgrading the inorganic filler and organic matrix from physical blending to chemical bonding, significantly enhancing the interfacial bonding force. The robust interface not only eliminates the stress concentration points caused by the debonding of traditional fillers, allowing external forces to be efficiently transferred to the rigid diatomaceous earth skeleton through chemical bonds, thereby improving tensile strength, but also prevents the debonding interface from becoming a preferential penetration channel for corrosive media, while also ensuring corrosion resistance. Third, the phosphate anchoring layer formed by phytic acid also possesses metal complexing capabilities, allowing it to form a passivation film on the exposed metal surface when corrosive media penetrates, providing active corrosion protection for the shielding layer and conductor. This effect further enhances corrosion resistance. Furthermore, the chemically bonded rigid diatomaceous earth particles bear the main load during wear, preventing abrasive wear caused by filler detachment and contributing positively to wear resistance.

[0017] On the other hand, a method for preparing the corrosion-resistant and wear-resistant control cable according to the present invention is provided, the method comprising the following steps: (1) The conductor is stranded and annealed; (2) An insulating layer is extruded onto the outside of the conductor; (3) Weave a shielding layer on the outside of the insulation layer and extrude to cover the inner sheath layer; (4) Preparation of functional modified filler: The functional modified filler is blended with the matrix layer and granulated, and then extruded and coated at 150~170 ℃ to form a composite outer sheath layer, and then subjected to online annealing at 80~120 ℃ for 10~30 min; cooled and shaped, and wound up to obtain the final product.

[0018] On another aspect, this invention provides the application of the corrosion-resistant and wear-resistant control cable described herein in improving the overall performance of control cables under complex working conditions.

[0019] Preferably, the overall performance characteristics include corrosion resistance, abrasion resistance, and tensile strength.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Regarding the improvement of the corrosion resistance of the composite outer sheath, on the one hand, the composite corrosion inhibitor is loaded into the pores of hydroxyl-modified diatomaceous earth. When corrosive media (such as salt spray, acidic or alkaline substances) begin to contact or attempt to penetrate the composite outer sheath, the porous structure of diatomaceous earth allows the corrosion inhibitor to be released in a controlled and slow manner in a humid or corrosive environment. The released corrosion inhibitor can form a dense protective film at potential metal contact points (such as shielding layers) or polymer cracks, effectively blocking the electrochemical corrosion pathway, thereby significantly inhibiting the initiation and spread of corrosion and achieving long-term protection. On the other hand, hydroxyl-modified diatomaceous earth is obtained through dual modification treatment with phytic acid and silane coupling agent KH-560. Phytic acid first reacts with the hydroxyl groups on the surface of the diatomaceous earth to form a strong phosphate ester anchoring layer, and then KH-560 reacts with it to form a surface rich in epoxy functional groups. This modification process greatly enhances the interfacial bonding force between the diatomaceous earth and the matrix layer. This strong interfacial bonding eliminates the microcracks and gaps formed between the traditional filler and the matrix due to weak physical adsorption, fundamentally blocking the preferential channel for the rapid penetration of corrosive media along the filler-matrix interface. Therefore, this invention overcomes the defect of passive barrier methods in the prior art, which fail after the appearance of microcracks in the material, and achieves superior and stable corrosion resistance.

[0021] (2) Regarding the improvement of the wear resistance of the composite outer sheath layer, on the one hand, the hydroxyl-modified diatomaceous earth, after double modification, forms a very strong chemical bond or interfacial bond with the polymer matrix, becoming a rigid reinforcing point firmly embedded in the matrix. When the cable sheath is subjected to friction or abrasive impact, these uniformly dispersed and tightly bonded rigid particles can effectively bear and disperse external shear and plowing stress, thereby protecting the relatively soft polymer matrix and preventing it from being worn out too quickly. At the same time, the strong interfacial bond also prevents the filler particles from detaching and falling off due to wear during use, avoiding the vicious cycle of the detached particles themselves becoming new abrasives and thus accelerating wear. On the other hand, the composite corrosion inhibitor loaded in the pores of the diatomaceous earth exhibits excellent lubrication performance and the potential to reduce the coefficient of friction in this invention, which can further improve the wear resistance.

[0022] (3) Regarding the improvement of the tensile strength (i.e., tensile strength) of the composite outer sheath layer, on the one hand, the hydroxyl-modified diatomaceous earth, after being chemically modified by a two-step process using phytic acid and KH-560, has a high density of reactive functional groups (such as phosphate ester bonds and epoxy groups) on its surface. During the melt blending and extrusion processing, these active groups can undergo chemical reactions or strong physical interactions with the polymer molecular chains in the matrix layer, forming a high-strength and highly stable chemical / physical bonding interface. This tough interface allows the stress in the composite outer sheath layer material to be efficiently transferred from the flexible polymer matrix to the rigid diatomaceous earth particles when subjected to tensile loads, avoiding the formation of local stress concentration points and crack initiation sources due to interface slippage or debonding. On the other hand, the rigid diatomaceous earth particles firmly bonded to the matrix serve as efficient stress-bearing points, which can share a considerable portion of the external tensile load. At the same time, when microcracks inside the material begin to propagate, these tightly bonded particles can effectively hinder the penetrating propagation of cracks, forcing the crack front to deflect, bifurcate, or become blunt, thereby absorbing more fracture energy and significantly improving the overall tensile strength and toughness of the composite material.

[0023] Since the composite outer sheath is a key functional layer for cables to resist external corrosion, wear and mechanical stress, the present invention can improve the performance of the composite outer sheath, which means that the present invention can improve the overall performance of corrosion-resistant and wear-resistant control cables. Detailed Implementation

[0024] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention clearer. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0025] The technical solution of the present invention will be described below with reference to embodiments. However, the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental methods and detection methods described in each embodiment are conventional methods; unless otherwise specified, the reagents and materials are all commercially available.

[0026] Example 1 This embodiment provides a corrosion-resistant and wear-resistant control cable, which includes, from the inside out, a conductor (TU2 oxygen-free copper), an insulation layer (SG-3 type polyvinyl chloride resin), a shielding layer (made of conventional tin-plated copper wire braid), an inner sheath layer (70℃ sheath-grade soft polyvinyl chloride plastic), and a composite outer sheath layer. The composite outer sheath layer includes a matrix layer and functional modified fillers dispersed in the matrix layer; by weight, the composite outer sheath layer includes: 100 parts matrix layer and 9.5 parts functional modified fillers; The matrix layer is a blend matrix of polyvinyl chloride and ethylene-vinyl acetate copolymer (blending temperature is 150 ℃, blending time is 15 min, stirring speed is 400 r / min), and the weight ratio of polyvinyl chloride (SG-5 type) and ethylene-vinyl acetate copolymer is 65:35. The functional modified filler is a composite particle of hydroxyl-modified diatomaceous earth loaded with a composite corrosion inhibitor (the composite corrosion inhibitor is loaded in the pores of hydroxyl-modified diatomaceous earth). The weight ratio of hydroxyl-modified diatomaceous earth to composite corrosion inhibitor is 1:0.15. The preparation method of the functional modified filler is as follows: hydroxyl-modified diatomaceous earth and composite corrosion inhibitor are ultrasonically dispersed in anhydrous ethanol (solid-liquid ratio of 1:6 g / mL, ultrasonic frequency of 40 kHz, power of 300 W, water bath temperature ≤40℃) for 30 min, vacuum dried at 60 ℃ for 12 h, and ground through a 200-mesh sieve to obtain the filler. Hydroxyl-modified diatomaceous earth is diatomaceous earth that has been sequentially modified with phytic acid and silane coupling agent KH-560 (phytic acid first reacts with the silanol groups on the surface of diatomaceous earth to form a phosphate ester anchoring layer, and silane coupling agent KH-560 then reacts with the remaining silanol groups and the phosphate groups of phytic acid to form an epoxy functionalized surface); the weight ratio of diatomaceous earth, phytic acid and silane coupling agent KH-560 is 100:2:1.5; the preparation method of hydroxyl-modified diatomaceous earth is as follows: diatomaceous earth is dispersed in a mixed solvent of ethanol / water volume ratio of 9:1, phytic acid is added and stirred at 60 ℃ for 4 h; then silane coupling agent KH-560 is added and refluxed at 80 ℃ for 6 h; filtered, washed three times with anhydrous ethanol, and dried at 100 ℃ to constant weight; The composite corrosion inhibitor is a compound of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether; the weight ratio of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether is 1:0.4:0.5; the molybdate is sodium molybdate.

[0027] Example 2 This embodiment provides a corrosion-resistant and wear-resistant control cable, which includes, from the inside out, a conductor (TU2 oxygen-free copper), an insulation layer (SG-3 type polyvinyl chloride resin), a shielding layer (made of conventional tin-plated copper wire braid), an inner sheath layer (70℃ sheath-grade soft polyvinyl chloride plastic), and a composite outer sheath layer. The composite outer sheath layer includes a matrix layer and functional modified fillers dispersed in the matrix layer; by weight, the composite outer sheath layer includes: 100 parts matrix layer and 18.5 parts functional modified fillers; The matrix layer is a blend matrix of polyvinyl chloride and ethylene-vinyl acetate copolymer (blending temperature is 155 ℃, blending time is 18 min, stirring speed is 450 r / min), and the weight ratio of polyvinyl chloride (SG-5 type) and ethylene-vinyl acetate copolymer is 80:20. The functional modified filler is a composite particle of hydroxyl-modified diatomaceous earth loaded with a composite corrosion inhibitor (the composite corrosion inhibitor is loaded in the pores of hydroxyl-modified diatomaceous earth). The weight ratio of hydroxyl-modified diatomaceous earth to composite corrosion inhibitor is 1:0.35. The preparation method of the functional modified filler is as follows: hydroxyl-modified diatomaceous earth and composite corrosion inhibitor are ultrasonically dispersed in anhydrous ethanol (solid-liquid ratio of 1:10 g / mL, ultrasonic frequency of 40 kHz, power of 300 W, water bath temperature ≤40 ℃) for 60 min, vacuum dried at 80 ℃ for 24 h, and ground through a 200-mesh sieve to obtain the filler. Hydroxyl-modified diatomaceous earth is diatomaceous earth that has been sequentially modified with phytic acid and silane coupling agent KH-560 (phytic acid first reacts with the silanol groups on the surface of diatomaceous earth to form a phosphate ester anchoring layer, and silane coupling agent KH-560 then reacts with the remaining silanol groups and the phosphate groups of phytic acid to form an epoxy functionalized surface); the weight ratio of diatomaceous earth, phytic acid and silane coupling agent KH-560 is 100:5:3; the preparation method of hydroxyl-modified diatomaceous earth is as follows: diatomaceous earth is dispersed in a mixed solvent of ethanol / water volume ratio of 9:1, phytic acid is added and stirred at 60 ℃ for 4 h; then silane coupling agent KH-560 is added and refluxed at 80 ℃ for 6 h; filtered, washed three times with anhydrous ethanol, and dried at 100 ℃ to constant weight. The composite corrosion inhibitor is a compound of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether; the weight ratio of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether is 1:0.8:1; the molybdate is calcium molybdate.

[0028] Example 3 This embodiment provides a corrosion-resistant and wear-resistant control cable, which includes, from the inside out, a conductor (TU2 oxygen-free copper), an insulation layer (SG-3 type polyvinyl chloride resin), a shielding layer (made of conventional tin-plated copper wire braid), an inner sheath layer (70℃ sheath-grade soft polyvinyl chloride plastic), and a composite outer sheath layer. The composite outer sheath layer includes a matrix layer and functional modified fillers dispersed in the matrix layer; by weight, the composite outer sheath layer includes: 100 parts matrix layer and 13 parts functional modified fillers; The matrix layer is a blend matrix of polyvinyl chloride and ethylene-vinyl acetate copolymer (blending temperature is 155 ℃, blending time is 16 min, stirring speed is 450 r / min), and the weight ratio of polyvinyl chloride (SG-5 type) and ethylene-vinyl acetate copolymer is 80:20. The functional modified filler is a composite particle of hydroxyl-modified diatomaceous earth loaded with a composite corrosion inhibitor (the composite corrosion inhibitor is loaded in the pores of hydroxyl-modified diatomaceous earth). The weight ratio of hydroxyl-modified diatomaceous earth to composite corrosion inhibitor is 1:0.2. The preparation method of the functional modified filler is as follows: hydroxyl-modified diatomaceous earth and composite corrosion inhibitor are ultrasonically dispersed in anhydrous ethanol (solid-liquid ratio of 1:7 g / mL, ultrasonic frequency of 40 kHz, power of 300 W, water bath temperature ≤40℃) for 40 min, vacuum dried at 60 ℃ for 16 h, and ground through a 200-mesh sieve to obtain the filler. Hydroxyl-modified diatomaceous earth is diatomaceous earth that has been sequentially modified with phytic acid and silane coupling agent KH-560 (phytic acid first reacts with the silanol groups on the surface of diatomaceous earth to form a phosphate ester anchoring layer, and silane coupling agent KH-560 then reacts with the remaining silanol groups and the phosphate groups of phytic acid to form an epoxy functionalized surface); the weight ratio of diatomaceous earth, phytic acid and silane coupling agent KH-560 is 100:3:2; the preparation method of hydroxyl-modified diatomaceous earth is as follows: diatomaceous earth is dispersed in a mixed solvent of ethanol / water volume ratio of 9:1, phytic acid is added and stirred at 60 ℃ for 4 h; then silane coupling agent KH-560 is added and refluxed at 80 ℃ for 6 h; filtered, washed three times with anhydrous ethanol, and dried at 100 ℃ to constant weight. The composite corrosion inhibitor is a compound of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether; the weight ratio of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether is 1:0.5:0.8; the molybdate is ammonium molybdate.

[0029] Example 4 This embodiment provides a method for preparing a corrosion-resistant and wear-resistant control cable, including the following steps: (1) The conductor is stranded and annealed (the annealing is performed in an air atmosphere, the annealing temperature is 350~380℃, and the annealing time is 2~2.5 h). (2) Extruding an insulating layer on the outside of the conductor (extrusion temperature is 135~145 ℃, extrusion speed is 7~8 m / min, and thickness is controlled at 0.5 mm±0.05 mm). (3) Weave a shielding layer on the outside of the insulation layer and extrude the inner sheath layer (extrusion temperature is 140~150 ℃, extrusion speed is 6~7 m / min, and thickness is controlled at 0.8 mm±0.08 mm). (4) Preparation of functional modified filler: The functional modified filler is blended with the matrix layer (5~8 min), granulated (temperature 160~165 ℃, speed 15~20 r / min), and then extruded and coated (extrusion temperature 150~170 ℃, extrusion speed 5~6 m / min) to form a composite outer sheath layer, and then subjected to online annealing treatment at 80~120 ℃ for 10~30 min; cooled and shaped (cooling and shaping adopts a combination of natural cooling and forced air cooling, cooling time is 15~20 min), and then pulled and wound to obtain the final product.

[0030] Comparative Example 1 This comparative example is the same as Example 3, except that the hydroxyl-modified diatomaceous earth is only modified with silane coupling agent KH-560, without phytic acid modification. The specific preparation method is as follows: diatomaceous earth is dispersed in a mixed solvent of ethanol / water at a volume ratio of 9:1, and silane coupling agent KH-560 is added directly. The mixture is refluxed at 80°C for 6 hours; filtered, washed three times with anhydrous ethanol, and dried at 100°C to constant weight. The weight ratio of diatomaceous earth to silane coupling agent KH-560 is 100:2. All other steps remain the same as in Example 3.

[0031] Comparative Example 2 This comparative example is the same as Example 3, except that the composite corrosion inhibitor only includes a compound of molybdate and benzotriazole, excluding fatty acid methyl ester polyoxyethylene ether. The weight ratio of molybdate to benzotriazole is 1:0.5, and the weight ratio of hydroxyl-modified diatomaceous earth to the composite corrosion inhibitor remains 1:0.2. Everything else is consistent with Example 3.

[0032] Comparative Example 3 This comparative example is the same as Example 3, except that: the functional modified filler is only a composite corrosion inhibitor and does not contain hydroxyl-modified diatomaceous earth; that is, molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether are directly mixed in a weight ratio of 1:0.5:0.8 and then blended with the matrix layer in the same weight parts (13 parts), without undergoing diatomaceous earth loading and ultrasonic dispersion treatment. The rest is consistent with Example 3.

[0033] Effect verification Experimental subjects: Corrosion-resistant and wear-resistant control cables prepared according to Example 4 in Examples 1-3 and Comparative Examples 1-3; Experimental methods: Corrosion resistance test: A 200 mm long sample of the composite outer sheath layer was cut from a corrosion-resistant and wear-resistant control cable, cleaned with anhydrous ethanol, and dried at room temperature for 24 hours. The sample thickness was uniform.

[0034] The test was conducted in accordance with GB / T 2423.17-2024 "Environmental Testing - Part 2: Test Methods - Test Ka: Salt Spray".

[0035] The sample is suspended vertically inside the programmable salt spray chamber, with the test surface facing upwards at an angle of 20±5° to the vertical. The sample holder is made of an inert non-metallic material (such as plastic) to avoid direct contact between the sample and the metal inner wall of the chamber. Test conditions are set as follows: NaCl solution concentration (5±1) wt%; total mass fraction of heavy metals (copper, nickel, lead) in sodium chloride ≤0.005%; total mass fraction of impurities ≤0.5%; solution pH 6.5~7.2; chamber temperature (35±2)℃; salt spray deposition rate (1~2) mL / 80cm. 2 • h; spraying method is continuous spraying; test cycle is 240 h (the 240 h test cycle is applicable to the performance evaluation of control cables under complex corrosion conditions). After the test, remove the sample, gently rinse it with running water at a temperature not exceeding 35℃ for 5 min, then rinse it with distilled water, and dry it at room temperature for 1~2 h. Observe and record the corrosion condition of the sample surface.

[0036] The surface corrosion status of samples after salt spray testing is rated according to the following criteria (0 is the best, 5 is the worst): 0: No surface change; 1: Slight discoloration or very few scattered corrosion spots; 2: Obvious discoloration or corrosion spot area ≤10%; 3: Blistering, cracking, or corrosion area 10-30%; 4: Obvious blistering, cracking, or corrosion area 30-50%; 5: Severe peeling, perforation, or corrosion area >50%.

[0037] The final result is represented by the arithmetic mean of the ratings of the three groups of samples.

[0038] Abrasion resistance test: A 750 mm long sample of the composite outer sheath was cut from a corrosion-resistant and abrasion-resistant control cable, cleaned with anhydrous ethanol, and dried at room temperature for 24 hours. Then, the sample was tested according to GB / T 17737.324-2018 "Coaxial Communication Cables - Part 1-324: Mechanical Test Methods - Cable Abrasion Resistance Test" (this standard is for coaxial communication cables, and the principle of its cable abrasion resistance test method is universal and can be understood and followed by those skilled in the field of control cables). Considering the frequent bending and dragging conditions encountered in actual use of control cables, the following accelerated simulation test conditions were set: 80-mesh quartz sandpaper was used as the friction medium; the contact pressure between the sample and the sandpaper was 10 N; the friction stroke was 150 mm; and the friction rate was 30 times / min. The number of reciprocating friction cycles was recorded when the composite outer sheath was worn through, exposing the inner sheath.

[0039] Abrasion resistance is expressed as the arithmetic mean of the number of abrasion tests conducted in four trials, with the result rounded to the nearest integer.

[0040] Tensile strength test: From corrosion-resistant and wear-resistant control cables, composite outer sheath layers were cut, and three sets of large dumbbell-shaped specimens (Type 1 specimens) were punched using a punching machine. These specimens were cleaned with anhydrous ethanol and dried at room temperature for 24 hours. The specimen width was taken as the minimum value of the three measured values, and the thickness was taken as the minimum value of three measured values ​​within the tensile region of each specimen. The original cross-sectional area was calculated using the formula: Original cross-sectional area (mm²) 2 = Width (mm) × Thickness (mm).

[0041] The test was conducted according to GB / T 2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 11: General Test Methods - Measurement of Thickness and Dimensions - Mechanical Properties Tests". The specimen was clamped in the electronic tensile testing machine fixture. The test conditions were set as follows: temperature (23±2)℃, relative humidity (50±5)%, tensile speed (25±5) mm / min. The testing machine was started, and the specimen was stretched until it broke. The maximum tensile force was recorded. The formula for calculating tensile strength is: Tensile strength (MPa) = Maximum tensile force (N) / Original cross-sectional area of ​​the specimen (mm²). 2 ).

[0042] The final result is expressed as the arithmetic mean of the tensile strength of the three groups of specimens, and the result is rounded to 0.1 MPa.

[0043] Experimental results are shown in Table 1.

[0044] Table 1 Performance test results for each group

[0045] As shown in Table 1, Examples 1-3 of the present invention exhibit excellent corrosion resistance (Example 3 is grade 0, Examples 1 and 2 are grade 1), significantly better than all comparative examples (Comparative Example 1 is grade 3, Comparative Example 2 is grade 2, and Comparative Example 3 is grade 4). The number of wear cycles of Examples 1-3 of the present invention (1260-1580 cycles) is much higher than that of the comparative examples (710-1130 cycles), with Example 3 reaching 1580 cycles, demonstrating superior wear resistance. The tensile strength of Examples 1-3 of the present invention (17.2-18.6 MPa) is also significantly higher than that of the comparative examples (12.3-15.5 MPa), indicating superior mechanical properties.

[0046] As can be seen, the corrosion-resistant and wear-resistant control cable provided by the present invention achieves a simultaneous and significant improvement in the corrosion resistance, wear resistance and tensile strength of the control cable by using phytic acid and silane coupling agent KH-560 to dual-modify diatomaceous earth and load a composite corrosion inhibitor (molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether compound), and utilizing the chemical bonding interface between the modified diatomaceous earth and the matrix layer. This effectively solves the technical problem that it is difficult to achieve all three properties in the prior art. Among them, Example 3 has the best comprehensive performance.

[0047] It should be understood that the disclosed invention is not limited to the specific methods, schemes, and substances described, as these are all subject to variation. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of the invention, which is limited only by the appended claims.

Claims

1. A corrosion-resistant and wear-resistant control cable, characterized in that, The corrosion-resistant and wear-resistant control cable comprises, from the inside out, a conductor, an insulation layer, a shielding layer, an inner sheath layer, and a composite outer sheath layer. The composite outer sheath layer includes a matrix layer and functional modified fillers dispersed in the matrix layer; The functional modified filler is a composite particle of hydroxyl-modified diatomaceous earth loaded with a composite corrosion inhibitor. The hydroxyl-modified diatomaceous earth is diatomaceous earth that has been successively modified with phytic acid and silane coupling agent KH-560. The composite corrosion inhibitor comprises a compound of molybdate, benzotriazole, and fatty acid methyl ester polyoxyethylene ether.

2. The corrosion-resistant and wear-resistant control cable according to claim 1, characterized in that, By weight, the composite outer sheath layer comprises: 100 parts matrix layer and 9.5 to 18.5 parts functional modified filler; In the functional modified filler, the weight ratio of hydroxyl-modified diatomaceous earth to composite corrosion inhibitor is 1:0.15~0.

35.

3. The corrosion-resistant and wear-resistant control cable according to claim 1, characterized in that, In the hydroxyl-modified diatomaceous earth, the weight ratio of diatomaceous earth, phytic acid, and silane coupling agent KH-560 is 100:2~5:1.5~3.

4. The corrosion-resistant and wear-resistant control cable according to claim 1, characterized in that, In the composite corrosion inhibitor, the weight ratio of molybdate, benzotriazole and fatty acid methyl ester polyoxyethylene ether is 1:0.4~0.8:0.5~1.

5. The corrosion-resistant and wear-resistant control cable according to claim 1, characterized in that, The matrix layer is a blend matrix of polyvinyl chloride and ethylene-vinyl acetate copolymer.

6. The corrosion-resistant and wear-resistant control cable according to claim 5, characterized in that, The weight ratio of the polyvinyl chloride and ethylene-vinyl acetate copolymer is 65~80:20~35.

7. The corrosion-resistant and wear-resistant control cable according to claim 1, characterized in that, The molybdate is selected from one or more of sodium molybdate, ammonium molybdate, and calcium molybdate.

8. The method for preparing the corrosion-resistant and wear-resistant control cable according to any one of claims 1 to 7, characterized in that, The preparation method includes the following steps: (1) The conductor is stranded and annealed; (2) An insulating layer is extruded onto the outside of the conductor; (3) Weave a shielding layer on the outside of the insulation layer and extrude to cover the inner sheath layer; (4) Preparation of functional modified filler: The functional modified filler is blended with the matrix layer and granulated, and then extruded and coated at 150~170 ℃ to form a composite outer sheath layer, and then subjected to online annealing at 80~120 ℃ for 10~30 min; cooled and shaped, and wound up to obtain the final product.

9. The application of the corrosion-resistant and wear-resistant control cable according to any one of claims 1 to 7 in improving the overall performance of control cables under complex working conditions.

10. The application according to claim 9, characterized in that, The overall performance characteristics include corrosion resistance, abrasion resistance, and tensile strength.

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