High-adhesion aging-resistant aerial insulated cable based on interface reinforcement and preparation method thereof
Patent Information
- Application Number
- CN202611148857.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-31
- Publication Date
- 2026-08-28
AI Technical Summary
[0003]本发明要解决的技术问题是：现有架空绝缘电缆中绝缘层与导体间的界面粘附力不足、安全裕度小、抗老化性能差
[0011] The beneficial effects of this invention are as follows: The multi-scale structure on the conductor surface, combined with the micro-arc oxidation porous ceramic layer and coupling agent chemical bonding, achieves a synergistic effect of physical anchoring and chemical bonding, increasing the adhesion force from the conventional 100-120N to over 200N, significantly increasing the margin. The modulus step structure composed of high-modulus and low-modulus layers gradually disperses and transfers the thermal expansion stress difference between the conductor and the insulating layer, significantly improving the interfacial reliability under thermo-mechanical combined action. Each layer adopts a unified silane crosslinking system and anti-aging system, with crosslinking and aging occurring simultaneously. The aging rate of each layer is consistent, extending the thermal aging life from 20 years to over 30 years, and the UV aging performance is significantly better than the national standard requirements. The grooves and void-like penetration channels provide a penetration path for the melt, and with the addition of a buffer layer, reliable bonding can be achieved even under extrusion conditions, reducing sensitivity to formulation and process parameters and significantly improving production stability.
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Figure CN122658770A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power transmission and cable manufacturing technology, and in particular to a high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement and its preparation method. Background Technology
[0002] During long-term outdoor operation, overhead insulated cables are susceptible to relative slippage between the insulation layer and conductor due to wind swaying, icing, and diurnal temperature variations. This slippage can directly lead to electrical short circuits. For overhead insulated cables without conductor shielding, the insulation layer is directly extruded onto the surface of aluminum or aluminum alloy conductors, making interface bonding particularly problematic. Conventional conductors use equal-diameter monofilaments with high-compression technology, resulting in a smooth and dense surface that makes it difficult for cross-linked polyethylene melt to penetrate, leading to a small effective bonding area. Small-diameter conductors exhibit adhesion strength of only 100-120N, barely meeting standards, and exhibiting poor batch stability. The dense oxide film on the surface of aluminum alloy conductors lacks active sites, preventing polyolefins from forming chemical bonds. Interface bonding relies entirely on physical friction, making them prone to peeling after long-term operation. Even more significant is the thermal stress mismatch problem. The coefficient of linear expansion of cross-linked polyethylene differs greatly from that of aluminum or aluminum alloys, resulting in significant residual tensile stress at the interface after cooling and setting, which becomes a source of microcrack initiation during long-term operation. Current product acceptance primarily relies on room temperature slippage force tests, which are insufficient to reflect the complex conditions of simultaneous thermal and mechanical stress. Furthermore, conventional cable insulation layers have limited resistance to aging, with a typical thermal aging life of only about 20 years. Therefore, achieving high adhesion and long-life aging resistance between the insulation layer and the conductor without a conductor shielding layer is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0003] The technical problem to be solved by the present invention is that the interfacial adhesion between the insulation layer and the conductor in existing overhead insulated cables is insufficient, the safety margin is small, and the anti-aging performance is poor.
[0004] The technical solution adopted by this invention to solve its technical problem is: a high-adhesion, aging-resistant overhead insulated cable, comprising a conductor, an in-situ reactive ceramic-molecular composite anchoring layer, a modulus step buffer layer, and a main insulation layer. The in-situ reactive ceramic-molecular composite anchoring layer and the modulus step buffer layer are sequentially disposed between the conductor and the main insulation layer. The conductor adopts a multi-scale stranded structure with a compression coefficient of 0.88-0.91, and grooved or axially porous permeation channels are formed on the conductor surface. The in-situ reactive ceramic-molecular composite anchoring layer includes a micro-arc oxidized porous ceramic layer and an organic coupling agent reaction interface layer attached thereto. The modulus step buffer layer includes a high-modulus reactive buffer sublayer and a low-modulus compatible buffer sublayer. Each layer uses the same silane graft crosslinking system, forming an integrated crosslinking network through wet crosslinking.
[0005] Furthermore, the conductor is a pure aluminum conductor or an aluminum alloy conductor, and the DC resistance after compression meets the maximum value specified in the corresponding specification of GB / T 3956-2008. The permeation channels on the conductor surface are formed by one of the following methods: the diameter of the outermost monofilament is smaller than the diameter of the adjacent inner monofilament and the number of outermost monofilaments is increased accordingly; the number of central monofilaments is greater than or equal to 2; or the outermost irregular monofilament of the irregular monofilament conductor is replaced with a round monofilament.
[0006] Furthermore, the high-modulus reactive buffer sublayer has a modulus of 800-1200 MPa, and the low-modulus compatible buffer sublayer has a modulus of 200-400 MPa. The thickness of the high-modulus reactive buffer sublayer is 80-120 μm, and the thickness of the low-modulus compatible buffer sublayer is 50-100 μm.
[0007] Furthermore, the organic coupling agent is γ-aminopropyltriethoxysilane; the polar modifier is maleic anhydride-grafted polyethylene.
[0008] Furthermore, each layer contains a unified anti-aging system, including 0.3-0.8 parts of primary antioxidant 1010, 0.3-0.8 parts of secondary antioxidant 168, 0.1-0.3 parts of metal ion passivator 1024, 0.2-0.5 parts of hindered amine light stabilizer Tinuvin 622, and 2.0-3.0 parts of carbon black.
[0009] Furthermore, the cable has a rated voltage of 1kV or 10kV, a lightweight thin insulation structure, and does not have a conductor shielding layer; the nominal conductor cross-section is 10-70mm². 2 At that time, the adhesion force is greater than or equal to 200N.
[0010] Furthermore, the thickness of the main insulation layer is 1.0-1.4 mm or 2.5 mm; the outer layer stranding pitch is 9-10 D.
[0011] The beneficial effects of this invention are as follows: The multi-scale structure on the conductor surface, combined with the micro-arc oxidation porous ceramic layer and coupling agent chemical bonding, achieves a synergistic effect of physical anchoring and chemical bonding, increasing the adhesion force from the conventional 100-120N to over 200N, significantly increasing the margin. The modulus step structure composed of high-modulus and low-modulus layers gradually disperses and transfers the thermal expansion stress difference between the conductor and the insulating layer, significantly improving the interfacial reliability under thermo-mechanical combined action. Each layer adopts a unified silane crosslinking system and anti-aging system, with crosslinking and aging occurring simultaneously. The aging rate of each layer is consistent, extending the thermal aging life from 20 years to over 30 years, and the UV aging performance is significantly better than the national standard requirements. The grooves and void-like penetration channels provide a penetration path for the melt, and with the addition of a buffer layer, reliable bonding can be achieved even under extrusion conditions, reducing sensitivity to formulation and process parameters and significantly improving production stability. Attached Figure Description
[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0013] Figure 1 This is a schematic diagram of the radial cross-sectional structure of the cable of the present invention.
[0014] Explanation of reference numerals in the attached figures: 1. Conductor; 2. In-situ reactive ceramic-molecular composite anchoring layer; 3. High-modulus reactive buffer sublayer; 4. Low-modulus compatible buffer sublayer; 5. Main insulating layer; Detailed Implementation
[0015] The technical solution will be explained in detail below with specific embodiments. The comparative example is a cable made with conventional processes. Embodiments 1 and 2 are 1kV products, and Embodiment 3 is a 10kV / Q type product.
[0016] The control example was prepared using conventional processes to produce 70mm samples. 2 Overhead insulated cable: The inner conductor consists of 6 aluminum monofilaments with a diameter of 2.5mm, and the outer conductor consists of 12 aluminum monofilaments with a diameter of 2.5mm. The compression coefficient is 0.93. The conductor surface is smooth and dense, without a buffer layer, micro-arc oxidation, or coupling agent treatment. The insulation layer is directly extruded onto the conductor surface, and cross-linking is performed using an 85℃ hot water bath for 4 hours. Test data are shown in Table 1. .
[0017] Example 1 is a 1kV JKLYJ specification 25mm 2 The cable employs a path-reduced diameter reinforcement design. The inner conductor consists of one plus six 1.8mm diameter aluminum monofilaments, while the outer layer comprises eight 1.5mm diameter aluminum monofilaments. The compression factor is 0.90, and the outer layer stranding pitch is 9.5D. The conductor is immersed in an electrolyte containing 8-10 g / L sodium silicate, 2.5-3.5 g / L sodium hexametaphosphate, and 1-2 g / L sodium hydroxide at pH 10-12 and a temperature of 20-40°C, under conditions of 400-600V and a current density of 8-10 A / dm³. 2 Micro-arc oxidation was performed for 12 minutes under certain conditions to generate a porous ceramic layer with a thickness of approximately 5 μm. A 1.5% KH550 solution was prepared using ethanol and water at a volume ratio of 95:5. After moderate stirring and hydrolysis for 45 minutes, the pH was adjusted to 4-5 with acetic acid. This solution was then sprayed onto the surface of the porous ceramic layer and dried at 80℃ for 8 minutes. A high-modulus reactive buffer sublayer (100 μm) and a low-modulus compatible buffer sublayer (60 μm) were sequentially extruded using a two-layer co-extrusion process, with barrel temperatures ranging from 140℃ to 160℃ to 165℃. A 1.4 mm main insulation layer was then extruded, with barrel temperatures ranging from 150℃ to 170℃ to 165℃ to 160℃. The cable was then immersed in a hot water bath at 85℃±5℃ for 6 hours. Test data are shown in Table 2. .
[0018] Example 2 is a 1kV JKLYJ specification 50mm 2 The cable employs a two-path, multi-core design. The core conductor layer consists of four 3.0mm diameter aluminum monofilaments arranged in a 2×2 configuration, while the outer layer contains ten 3.0mm diameter aluminum monofilaments with a compression factor of 0.90. The micro-arc oxidation, coupling agent treatment, buffer layer co-extrusion, main insulation layer extrusion, and wet cross-linking process parameters are the same as in Example 1. Test data are shown in Table 3. .
[0019] Example 3 is a 10kV JKLYJ / Q specification 70mm 2 This lightweight, thin-insulated cable employs a path-reducing, wire-adding design. The inner conductor layer contains one and six 2.5mm diameter aluminum monofilaments, the middle layer contains twelve 2.5mm diameter aluminum monofilaments, and the outer layer contains eighteen reduced-diameter monofilaments. The main insulation layer thickness is adjusted to 2.5mm. The remaining formulation and process parameters are the same as in Example 1. Test data are shown in Table 4. .
Claims
1. A high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement, characterized in that: The structure includes a conductor (1), an in-situ reactive ceramic-molecular composite anchoring layer (2), a modulus step buffer layer, and a main insulation layer (5). The in-situ reactive ceramic-molecular composite anchoring layer (2) and the modulus step buffer layer are sequentially disposed between the conductor (1) and the main insulation layer (5). The conductor (1) adopts a multi-scale stranded structure with a compaction coefficient of 0.88-0.
91. Groove-shaped or axially void-shaped permeation channels are formed on the surface of the conductor (1). The equivalent opening width of the permeation channels is 0.1-0.3 mm, the equivalent depth is 0.1-0.4 mm, and they are spirally and continuously distributed along the axial direction of the conductor (1). The in-situ reactive ceramic-molecular composite anchoring layer (2) includes micro-arc oxidation porous layers. The ceramic layer and the organic coupling agent reaction interface layer attached thereto, the micro-arc oxidized porous ceramic layer is 3-8 μm thick and has micropores with a pore size of 0.5-2 μm and a porosity of 20-25% distributed on its surface; the modulus step buffer layer includes a high modulus reactive buffer sublayer (3) near the conductor (1) and a low modulus compatible buffer sublayer (4) near the main insulating layer (5), the high modulus reactive buffer sublayer (3) contains a polar modifier that can react with the amino terminus of the coupling agent; the high modulus reactive buffer sublayer (3), the low modulus compatible buffer sublayer (4) and the main insulating layer (5) adopt the same silane graft crosslinking system and form an integrated crosslinking network by wet crosslinking.
2. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The conductor (1) is a pure aluminum conductor or an aluminum alloy conductor, and its DC resistance after compression meets the maximum value specified in the corresponding specification of GB / T 3956-2008; the permeation channel on the surface of the conductor (1) is formed by one of the following methods: (i) the diameter of the outermost monofilament is smaller than the diameter of the adjacent inner monofilament, and the number of outermost monofilaments increases accordingly; (ii) the number of central monofilaments is greater than or equal to 2; (iii) the outermost irregular monofilament of the irregular monofilament conductor is replaced with a round monofilament.
3. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The high-modulus reactive buffer sublayer (3) has a modulus of 800-1200 MPa, and the low-modulus compatible buffer sublayer (4) has a modulus of 200-400 MPa; the high-modulus reactive buffer sublayer (3) has a thickness of 80-120 μm, and the low-modulus compatible buffer sublayer (4) has a thickness of 50-100 μm.
4. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The organic coupling agent is γ-aminopropyltriethoxysilane; the polar modifier is maleic anhydride-grafted polyethylene.
5. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The high-modulus reactive buffer sublayer (3), the low-modulus compatible buffer sublayer (4), and the main insulating layer (5) contain a unified anti-aging system, which includes a main antioxidant, an auxiliary antioxidant, a metal ion passivator, a hindered amine light stabilizer, and carbon black; wherein the main antioxidant 1010 is 0.3-0.8 parts, the auxiliary antioxidant 168 is 0.3-0.8 parts, the metal ion passivator 1024 is 0.1-0.3 parts, the hindered amine light stabilizer Tinuvin 622 is 0.2-0.5 parts, and the carbon black is 2.0-3.0 parts.
6. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The cable has a rated voltage of 1kV or 10kV, a lightweight thin insulation structure, and does not have a conductor shielding layer; the nominal cross-sectional area of the conductor is 10-70mm². 2 At that time, the adhesion force between the insulation layer and the conductor is greater than or equal to 200N.
7. The high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement according to claim 1, characterized in that: The thickness of the main insulation layer (5) is 1.0-1.4 mm or 2.5 mm; the outer layer stranding pitch is 9-10D, where D is the outer diameter of the stranded conductor.
8. A method for preparing a high-adhesion, aging-resistant overhead insulated cable based on interface reinforcement as described in any one of claims 1 to 7, characterized in that: Includes the following steps: S1. Conductor stranding and compaction: Aluminum or aluminum alloy monofilaments are stranded into a multi-scale structure and compacted using a mold with a compaction coefficient of 0.88-0.91, so that groove-like or axially void-like permeation channels are formed on the surface of the conductor (1), wherein the equivalent opening width of the permeation channel is 0.1-0.3 mm and the equivalent depth is 0.1-0.4 mm; S2. Micro-arc oxidation: The conductor is immersed in a composite electrolyte containing sodium silicate and sodium hexametaphosphate at pH 10-12, and the electrolyte temperature is controlled at 20-40℃, voltage at 400-600V, and current density at 8-10A / dm³. 2 S3. Coupling agent treatment: Spray γ-aminopropyltriethoxysilane hydrolysate at pH 4-5 onto the surface of the porous ceramic layer and dry at 80℃±5℃ for 5-10 minutes to form a coupling agent reaction interface layer; S4. Buffer layer co-extrusion: Use a double-layer co-extrusion process to extrude a high-modulus reactive buffer sublayer (3) and a low-modulus compatible buffer sublayer (4) in sequence; S5. Main insulation layer extrusion: Extrude the main insulation layer (5); S6. Wet crosslinking: Immerse the extruded cable in a hot water bath at 85℃±5℃ for 6 hours to allow the silanes of each layer to crosslink synchronously.
9. The preparation method according to claim 8, characterized in that: The barrel temperature for co-extruding the buffer layer in S4 is 140℃→160℃→165℃.
10. The preparation method according to claim 8, characterized in that: The barrel temperature for extruding the main insulation layer in S5 is 150℃→170℃→165℃→160℃.