High-weather-resistance electrical conduit and preparation process thereof
By using hydroxyapatite nanosheets and graphitic carbon nitride composite fillers in electrical conduits to form a dense core-shell layered structure, the problems of service life and safety of electrical conduits in outdoor environments are solved, and the improvement of high weather resistance and mechanical properties is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENJIE TECH (SUZHOU) CO LTD
- Filing Date
- 2026-02-28
- Publication Date
- 2026-05-12
AI Technical Summary
Existing high-protection electrical conduits suffer from limitations in single function, poor interfacial compatibility, lack of active protection mechanisms, and insufficient dispersion and stability of inorganic fillers, which limit their service life and safety in outdoor or harsh environments.
Using hydroxyapatite nanosheets as a substrate, a dense core-shell composite structure is formed by in-situ thermal condensation to generate a graphitic carbon nitride shell. Furthermore, the dispersibility and compatibility of the filler in epoxy resin are improved by modifying it with dodecyl phosphate, thus constructing a highly efficient physical shielding and active environmental response coating.
It significantly improves the weather resistance, UV aging resistance and mechanical properties of electrical conduits, provides photocathode protection and self-cleaning function, extends service life and improves coating adhesion and mechanical properties.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrical conduit technology, and relates to a high weather-resistant electrical conduit and its manufacturing process. Background Technology
[0002] Electrical conduits are critical components used in the construction, industrial, and infrastructure sectors for the protection, installation, and insulation of electrical wires and cables. When exposed to outdoor or harsh industrial environments for extended periods, they must withstand various factors, including ultraviolet radiation, rainwater erosion, temperature cycling, chemical corrosion, and physical impact. Therefore, the weather resistance, corrosion resistance, and mechanical durability of the conduit's outer protective coating directly determine the safety, reliability, and service life of the entire electrical system.
[0003] Currently, most high-protection electrical conduits on the market adopt a composite structure of metal base tube with an organic coating. However, existing technologies generally suffer from limitations such as single-function limitations, poor interfacial compatibility, lack of active protection mechanisms, and insufficient dispersion and stability of inorganic fillers.
[0004] Therefore, developing a novel composite filler and its matching coating system that can simultaneously achieve long-term physical shielding, active environmental response, and good compatibility with resin, and thus prepare a high-weather-resistant electrical conduit, has significant industrial application value and practical significance. Summary of the Invention
[0005] The purpose of this invention is to provide a high weather-resistant electrical conduit and its manufacturing process, which has the characteristics of good mechanical properties, high weather resistance and high corrosion resistance.
[0006] The objective of this invention can be achieved through the following technical solutions: A high weather-resistant electrical conduit, comprising a base tube and a weather-resistant protective coating laminated on the surface of the steel base tube. The weather-resistant protective coating is obtained by applying a weather-resistant protective coating to the outer surface of the base pipe and curing it. The formula of the weather-resistant protective coating is as follows, calculated by weight: 55-75 parts epoxy resin, 5-10 parts composite filler, 1-2 parts leveling agent, 1-2 parts defoamer, 10-20 parts curing agent, and 40-60 parts solvent. The preparation method of the composite filler is as follows: S1-1: Hydroxyapatite nanosheets were dispersed in an aqueous solution of melamine and stirred at 60-70 °C until the water evaporated. The mixture was then transferred to a tube furnace and calcined under a high-purity nitrogen atmosphere. After natural cooling, the product was dispersed in deionized water and sonicated for 1-2 h. The solid was collected by centrifugation, washed with deionized water, and then vacuum dried at 60-80 °C for 12 h to obtain powder A. S1-2: Disperse powder A in deionized water, stir at 60-70 °C for 30-60 min, add dodecyl phosphate aqueous solution dropwise, maintain temperature and continue stirring for 4-6 h, collect the solid by centrifugation, wash with deionized water, and then place it at 60-80 °C for vacuum drying for 12 h to obtain the composite filler.
[0007] As a preferred embodiment of the present invention, the mass ratio of hydroxyapatite nanosheets to melamine in S1-1 is 1:(5~15).
[0008] As a preferred embodiment of the present invention, the calcination parameters in S1-1 are set to increase the temperature to 500-550°C at a rate of 2-5°C / min and hold for 2-4 hours.
[0009] As a preferred embodiment of the present invention, the ultrasonic power in S1-1 is 80~120 W.
[0010] As a preferred embodiment of the present invention, the mass ratio of powder A to dodecyl phosphate in S1-2 is 1:(0.05~0.2).
[0011] As a preferred embodiment of the present invention, the leveling agent is one or more of BYK-360P, BYK-333, and Digo 410.
[0012] As a preferred embodiment of the present invention, the defoamer is one or both of benzoin and BYK-024.
[0013] In a preferred embodiment of the present invention, the epoxy resin is of type E-12, the curing agent is dicyandiamide, and the solvent is ethanol.
[0014] A manufacturing process for a high weather-resistant electrical conduit, the manufacturing process comprising the following steps: S9-1. Pretreatment of the base pipe: The outer surface of the steel base pipe is shot blasted to remove rust, and then phosphated. S9-2. Coating preparation: According to the weight ratio, epoxy resin, composite filler, leveling agent, defoamer and half the mass of solvent are mixed and dispersed for 30~60 min to obtain slurry. Add curing agent and remaining solvent, and continue to disperse for 30~60 min to obtain weather-resistant protective coating. S9-3. Coating application: The weather-resistant protective coating is applied to the outer surface of the pretreated base pipe to obtain the weather-resistant protective coating. It is first pre-cured at 40~60℃ for 20~40 min, and then heated to 80~100℃ for further curing for 40~60 min to obtain the high weather-resistant electrical conduit.
[0015] As a preferred embodiment of the present invention, the weather-resistant protective coating has a coating thickness of 150~250μm.
[0016] The composite filler in this invention uses hydroxyapatite nanosheets as a substrate, which possess excellent chemical stability and a sheet-like physical morphology. A graphitic carbon nitride shell, formed on the surface through in-situ thermal condensation, further constitutes a dense core-shell composite structure. This composite structure forms a highly tortuous physical barrier path within the coating, effectively delaying the penetration of water vapor, oxygen, and corrosive ions, providing physical shielding protection for the steel base pipe. The graphitic carbon nitride shell is chemically extremely stable and exhibits excellent absorption and scattering of ultraviolet light. Synergistically with the epoxy resin matrix, it significantly enhances the overall UV aging resistance of the coating, ensuring the weather resistance of the electrical conduit for long-term outdoor use. Furthermore, graphitic carbon nitride, as a semiconductor photocatalytic material, endows the filler and coating with new functional dimensions. Under illumination, graphitic carbon nitride can generate photogenerated carriers. These photogenerated electrons can migrate to the surface of the metal substrate, causing cathodic polarization, thereby providing a photocathode protection effect and actively inhibiting metal corrosion. Meanwhile, photogenerated holes have a strong oxidizing ability, which can decompose harmful organic matter attached to the coating surface or inhibit the growth of microorganisms, giving the coating a potential self-cleaning function and helping to maintain its long-term protective performance and appearance.
[0017] Surface organic modification of composite fillers using dodecyl phosphate significantly improves the dispersibility and compatibility of the composite filler in the epoxy resin matrix, avoiding coating defects caused by filler agglomeration. The phosphate groups can form chemical bonds with active sites on the surface of graphitic carbon nitride or hydroxyapatite, while their long organic chains can effectively entangle with the epoxy resin, thus constructing a strong organic-inorganic bridging interface between the filler and the resin. This strong interfacial bonding not only ensures the stable existence of the functional filler but also effectively transfers stress from the relatively flexible resin matrix to the high-modulus flake filler, thereby simultaneously improving the coating's adhesion, hardness, wear resistance, impact resistance, and other mechanical properties, overcoming the drawback of increased coating brittleness caused by the addition of traditional rigid fillers.
[0018] The beneficial effects of this invention are: In this invention, the composite filler uses hydroxyapatite nanosheets as a substrate, with graphitic carbon nitride grown in situ on the surface to form a dense layer. This layer creates a highly efficient physical barrier in the coating, delaying the penetration of corrosive media and enhancing resistance to UV aging. The graphitic carbon nitride layer imparts photocatalytic activity to the material, generating photogenerated electrons that migrate to the metal substrate under light, providing photocathode protection. Simultaneously, it utilizes strong oxidizing holes to achieve surface self-cleaning. Subsequently, modification with dodecyl phosphate significantly improves the dispersibility and compatibility of the filler in epoxy resin, while the phosphate groups strengthen the interfacial bonding between the inorganic filler and the organic resin, thereby simultaneously improving coating adhesion and mechanical properties, overcoming the drawback of coating embrittlement caused by traditional filler additions. Detailed Implementation
[0019] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.
[0020] It should be noted that, unless otherwise specified, the present invention does not specifically limit the source of the raw materials used in the following embodiments. Commercially available products or products prepared by conventional preparation methods that are well known to those skilled in the art can be used. Experimental methods that do not specify specific conditions are all conventional methods and conventional conditions well known in the art.
[0021] A high weather-resistant electrical conduit, comprising a base tube and a weather-resistant protective coating laminated on the surface of the steel base tube. The weather-resistant protective coating is obtained by applying a weather-resistant protective paint to the outer surface of the base pipe and curing it. The formula of the weather-resistant protective paint is as follows, calculated by weight: 65 parts epoxy resin E-12, 7.5 parts composite filler, 1.5 parts BYK-360P, 1.5 parts benzoin, 15 parts dicyandiamide, and 50 parts ethanol. The preparation method of the composite filler is as follows: S1-1: Hydroxyapatite nanosheets were dispersed in an aqueous solution of melamine at a mass ratio of 1:10. The mixture was stirred at 65 °C until the water evaporated. The mixture was then transferred to a tube furnace and calcined under a high-purity nitrogen atmosphere. The temperature was increased to 530 °C at a rate of 3 °C / min and held for 3 h. After natural cooling, the product was dispersed in deionized water and sonicated for 1.5 h at a power of 100 W. The solid was collected by centrifugation, washed with deionized water, and then vacuum dried at 70 °C for 12 h to obtain powder A. S1-2: Disperse powder A in deionized water, stir at 65 °C for 45 min, add an aqueous solution of dodecyl phosphate dropwise, the mass ratio of powder A to dodecyl phosphate is 1:0.1, maintain the temperature and continue stirring for 5 h, collect the solid by centrifugation, wash with deionized water, and then place it at 70 °C for vacuum drying for 12 h to obtain the composite filler.
[0022] A manufacturing process for a high weather-resistant electrical conduit, the manufacturing process comprising the following steps: S9-1. Pretreatment of the base pipe: The outer surface of the steel base pipe is shot blasted to remove rust, and then phosphated. S9-2. Coating preparation: According to the weight ratio, epoxy resin, composite filler, leveling agent, defoamer and half the mass of solvent are mixed and dispersed for 45 min to obtain slurry. Add curing agent and remaining solvent and continue to disperse for 45 min to obtain weather-resistant protective coating. S9-3. Coating application: The weather-resistant protective coating is applied to the outer surface of the pretreated base pipe to obtain a weather-resistant protective coating with a thickness of 200μm. It is first pre-cured at 50℃ for 30 min, and then heated to 90℃ for further curing for 50 min to obtain the high weather-resistant electrical conduit.
[0023] Example 2 A high weather-resistant electrical conduit, comprising a base tube and a weather-resistant protective coating laminated on the surface of the steel base tube. The weather-resistant protective coating is obtained by applying a weather-resistant protective coating to the outer surface of the base pipe and curing it. The formula of the weather-resistant protective coating is as follows, calculated by weight: 55 parts epoxy resin E-12, 5 parts composite filler, 1 part BYK-333, 1 part BYK-024, 10 parts dicyandiamide, and 40 parts ethanol. The preparation method of the composite filler is as follows: S1-1: Hydroxyapatite nanosheets were dispersed in an aqueous solution of melamine at a mass ratio of 1:5. The mixture was stirred at 60 °C until the water evaporated. The mixture was then transferred to a tube furnace and calcined under a high-purity nitrogen atmosphere. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 h. After natural cooling, the product was dispersed in deionized water and sonicated for 1 h at an ultrasonic power of 80 W. The solid was collected by centrifugation, washed with deionized water, and then vacuum dried at 60-80 °C for 12 h to obtain powder A. S1-2: Disperse powder A in deionized water, stir at 60 °C for 30 min, add an aqueous solution of dodecyl phosphate dropwise, the mass ratio of powder A to dodecyl phosphate is 1:0.05, maintain the temperature and continue stirring for 4 h, collect the solid by centrifugation, wash with deionized water, and then place it in a vacuum dryer at 60 °C for 12 h to obtain the composite filler.
[0024] A manufacturing process for a high weather-resistant electrical conduit, the manufacturing process comprising the following steps: S9-1. Pretreatment of the base pipe: The outer surface of the steel base pipe is shot blasted to remove rust, and then phosphated. S9-2. Coating preparation: According to the weight ratio, epoxy resin, composite filler, leveling agent, defoamer and half the mass of solvent are mixed and dispersed for 30~60 min to obtain slurry. Add curing agent and remaining solvent, and continue to disperse for 30~60 min to obtain weather-resistant protective coating. S9-3. Coating application: The weather-resistant protective coating is applied to the outer surface of the pretreated base pipe to obtain a weather-resistant protective coating with a thickness of 150μm. It is first pre-cured at 40℃ for 40 min, and then heated to 80℃ for further curing for 60 min to obtain the high weather-resistant electrical conduit.
[0025] Example 3 A high weather-resistant electrical conduit, comprising a base tube and a weather-resistant protective coating laminated on the surface of the steel base tube. The weather-resistant protective coating is obtained by applying a weather-resistant protective coating to the outer surface of the base pipe and curing it. The formula of the weather-resistant protective coating is as follows, calculated by weight: 75 parts epoxy resin E-12, 10 parts composite filler, 2 parts TIG410, 2 parts BYK-024, 20 parts dicyandiamide, and 60 parts ethanol. The preparation method of the composite filler is as follows: S1-1: Hydroxyapatite nanosheets were dispersed in an aqueous solution of melamine at a mass ratio of 1:15. The mixture was stirred at 70 °C until the water evaporated. The mixture was then transferred to a tube furnace and calcined under a high-purity nitrogen atmosphere. The temperature was increased to 550 °C at a rate of 5 °C / min and held for 4 h. After natural cooling, the product was dispersed in deionized water and sonicated for 2 h at a power of 120 W. The solid was collected by centrifugation, washed with deionized water, and then vacuum dried at 80 °C for 12 h to obtain powder A. S1-2: Disperse powder A in deionized water, stir at 70 °C for 60 min, add an aqueous solution of dodecyl phosphate dropwise, the mass ratio of powder A to dodecyl phosphate is 1:0.2, maintain the temperature and continue stirring for 6 h, collect the solid by centrifugation, wash with deionized water, and then place it at 80 °C for vacuum drying for 12 h to obtain the composite filler.
[0026] A manufacturing process for a high weather-resistant electrical conduit, the manufacturing process comprising the following steps: S9-1. Pretreatment of the base pipe: The outer surface of the steel base pipe is shot blasted to remove rust, and then phosphated. S9-2. Coating preparation: According to the weight ratio, epoxy resin, composite filler, leveling agent, defoamer and half the mass of solvent are mixed and dispersed for 60 min to obtain slurry. Add curing agent and remaining solvent and continue to disperse for 60 min to obtain weather-resistant protective coating. S9-3. Coating application: The weather-resistant protective coating is applied to the outer surface of the pretreated base pipe to obtain a weather-resistant protective coating with a thickness of 250μm. It is first pre-cured at 60℃ for 20 min, and then heated to 100℃ for further curing for 40 min to obtain the high weather-resistant electrical conduit.
[0027] Comparative Example 1 The difference between this comparative example and Example 1 is that graphitic carbon nitride is used instead of composite filler, while the rest are the same as in Example 1.
[0028] Comparative Example 2 The difference between this comparative example and Example 1 is that hydroxyapatite nanosheets are used instead of composite fillers; otherwise, they are the same as in Example 1.
[0029] Comparative Example 3 The difference between this comparative example and Example 1 is that the preparation of the composite filler does not involve step S1-2, while the rest is the same as in Example 1.
[0030] Comparative Example 4 The difference between this comparative example and Example 1 is that in the preparation of the composite filler, graphitic carbon nitride and hydroxyapatite nanosheets were mechanically mixed to replace powder A, while the rest were the same as in Example 1.
[0031] Performance testing The weather resistance of the electrical conduits prepared in the examples and comparative examples was tested with reference to GB / T 1865-2009 standard, using QUVB accelerated aging test for 1000 h.
[0032] The corrosion resistance of the electrical conduits prepared in the examples and comparative examples was tested in accordance with GB / T1771-2007 standard. The tests were conducted on a JD-120 (600L) salt spray tester with a sodium chloride solution concentration of 50 g / L and a pH of 7.0.
[0033] The impact resistance of the electrical conduits prepared in the examples and comparative examples was tested in accordance with the GB / T1732-2020 standard. The mass of the hammer was 1000 g, and the paint film was observed to be damaged by magnification of 4 times. The maximum height of the hammer drop when the film was not damaged was taken as the measurement result. The specific experimental results are summarized in the table below.
[0034] As can be seen from the above embodiments and comparative data, the electrical conduit produced by the present invention has superior weather resistance, corrosion resistance and impact resistance.
[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are still within the scope of the present invention.
Claims
1. A high weather-resistant electrical conduit, characterized in that, The electrical conduit includes a base tube and a weather-resistant protective coating laminated on the surface of the steel base tube. The weather-resistant protective coating is obtained by applying a weather-resistant protective coating to the outer surface of the base pipe and curing it. The formula of the weather-resistant protective coating is as follows, calculated by weight: 55-75 parts epoxy resin, 5-10 parts composite filler, 1-2 parts leveling agent, 1-2 parts defoamer, 10-20 parts curing agent, and 40-60 parts solvent. The preparation method of the composite filler is as follows: S1-1: Hydroxyapatite nanosheets were dispersed in an aqueous solution of melamine and stirred at 60-70 °C until the water evaporated. The mixture was then transferred to a tube furnace and calcined under a high-purity nitrogen atmosphere. After natural cooling, the product was dispersed in deionized water and sonicated for 1-2 h. The solid was collected by centrifugation, washed with deionized water, and then vacuum dried at 60-80 °C for 12 h to obtain powder A. S1-2: Disperse powder A in deionized water, stir at 60-70 °C for 30-60 min, add dodecyl phosphate aqueous solution dropwise, maintain temperature and continue stirring for 4-6 h, collect the solid by centrifugation, wash with deionized water, and then place it at 60-80 °C for vacuum drying for 12 h to obtain the composite filler.
2. The high weather-resistant electrical conduit according to claim 1, characterized in that, The mass ratio of hydroxyapatite nanosheets to melamine in S1-1 is 1:(5~15).
3. The high weather-resistant electrical conduit according to claim 1, characterized in that, The calcination parameters in S1-1 are set to increase the temperature to 500-550℃ at a rate of 2-5℃ / min and hold for 2-4 hours.
4. The high weather-resistant electrical conduit according to claim 1, characterized in that, The ultrasonic power in S1-1 is 80~120 W.
5. A high weather-resistant electrical conduit according to claim 1, characterized in that, In S1-2, the mass ratio of powder A to dodecyl phosphate is 1:(0.05~0.2).
6. The high weather-resistant electrical conduit according to claim 1, characterized in that, The leveling agent is one or more of BYK-360P, BYK-333, and Digo 410.
7. The high weather-resistant electrical conduit according to claim 1, characterized in that, The defoamer is one or both of benzoin and BYK-024.
8. A high weather-resistant electrical conduit according to claim 1, characterized in that, The epoxy resin is of type E-12, the curing agent is dicyandiamide, and the solvent is ethanol.
9. A manufacturing process for a high weather-resistant electrical conduit as described in any one of claims 1 to 8, characterized in that, The preparation process includes the following steps. S9-1. Pretreatment of the base pipe: The outer surface of the steel base pipe is shot blasted to remove rust, and then phosphated. S9-2. Coating preparation: According to the weight ratio, epoxy resin, composite filler, leveling agent, defoamer and half the mass of solvent are mixed and dispersed for 30~60 min to obtain slurry. Add curing agent and remaining solvent, and continue to disperse for 30~60 min to obtain weather-resistant protective coating. S9-3. Coating application: The weather-resistant protective coating is applied to the outer surface of the pretreated base pipe to obtain the weather-resistant protective coating. It is first pre-cured at 40~60℃ for 20~40 min, and then heated to 80~100℃ for further curing for 40~60 min to obtain the high weather-resistant electrical conduit.
10. The manufacturing process of a high weather-resistant electrical conduit according to claim 9, characterized in that, The thickness of the weather-resistant protective coating is 150~250μm.