Thermochromic material cable and preparation method thereof

Abstract

The invention discloses a thermochromic material cable and a preparation method thereof, and relates to the field of power equipment. A thermochromic material cable comprises at least one insulating wire core, an inner wrapping layer is wrapped outside the insulating wire core, a sheath layer is wrapped outside the inner wrapping layer, the insulating wire core sequentially comprises a conductor, a wire sheath and an insulating layer from inside to outside, and the sheath layer comprises the following raw materials in parts by weight: 140-210 parts of a sheath raw material; 1 to 2.2 parts of a thermochromic microcapsule; the raw material of the sheath adopts polyvinyl chloride resin as a base material; the thermochromic microcapsule selects modified melamine-formaldehyde-ethyl cellulose as a capsule wall material and a thermochromic material as a capsule core, the mass ratio of the capsule core to the capsule wall material is (2-2.5): 1, and the average particle size is 0.3-0.7 mu m. According to the thermochromic cable, the high temperature resistance and the ultraviolet resistance of the thermochromic material added into the cable can be improved, so that the thermochromic material cable can realize temperature detection and early warning discoloration for a long time.

Description

Technical Field

[0001] The present invention relates to the field of electric power equipment, and in particular to a thermochromic material cable and a preparation method thereof. Background Art

[0002] A cable is a device for transmitting electrical energy or signals, and is a wire product used to transmit electrical (magnetic) energy, information, and convert electromagnetic energy. A cable is specifically defined as a conductor consisting of one or more mutually insulated conductors and an outer insulating protective layer, used to transmit electricity or information from one location to another. During cable transmission, high thermal resistance limits the cable's current carrying capacity. Excessive heat accumulation and high ambient temperatures can cause fires, necessitating timely warnings and effective regulation of the cable's current carrying capacity.

[0003] Thermochromic materials change color when heated to a certain temperature (or temperature range), showing a new color. Therefore, thermochromic materials can be used to detect and display the temperature of the cable, playing a warning role.

[0004] Existing thermochromic cables typically incorporate thermochromic powder directly into the cable's insulation layer. However, this powder suffers from limitations such as poor heat resistance and UV resistance. When used in cables intended for outdoor use, the powder is susceptible to UV aging and its color-changing properties can be lost in high-temperature environments, making it unsuitable for long-term cable use. Summary of the Invention

[0005] In order to improve the high temperature resistance and UV resistance of the thermochromic material added to the cable, so that the thermochromic material cable can achieve long-term temperature detection and early warning color change, the present application provides a thermochromic material cable and a preparation method thereof.

[0006] The present application provides a thermochromic material cable and a preparation method thereof using the following technical solutions: In a first aspect, the present application discloses a thermochromic material cable, comprising at least one insulated core, the insulated core being covered with an inner sheath, the inner sheath being covered with a sheath, the insulated core comprising, from the inside to the outside, a conductor, a sheath, and an insulating layer, the sheath comprising the following raw materials in parts by weight: 140-210 parts of sheath raw material; 1-2.2 parts of thermochromic microcapsules; Among them, the sheath material is made of polyvinyl chloride resin as the base material; The thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as capsule material and thermochromic material as capsule core. The mass ratio of capsule core to capsule material is (2-2.5):1, and the average particle size is 0.3-0.7μm.

[0007] By adopting the above technical solution, the thermochromic cable of the present application incorporates thermochromic microcapsules into its sheath layer, thereby achieving a high-temperature warning function for the cable through the reversible color change of the thermochromic microcapsules at high temperatures. Since the thermochromic microcapsules are evenly dispersed in the cable sheath layer, when the temperature rises locally due to a cable fault, the color change of the thermochromic material achieves a uniform color change across the cable, further facilitating the display and early warning of high-temperature conditions.

[0008] Thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as the capsule material, which protects the capsule core of the thermochromic material. The capsule material is resistant to high temperatures and UV rays, so that during the long-term use of the cable, the thermochromic material will not age due to ultraviolet radiation or fail due to high temperatures, thereby extending the service life of the thermochromic microcapsules.

[0009] Optionally, the modified melamine-formaldehyde-ethyl cellulose includes the following raw materials in parts by weight: 6-9 parts of melamine; 4-6 parts of paraformaldehyde; 15-21 parts of methanol; 2-4 parts of ethyl cellulose; 0.7-1.3 parts of nano titanium dioxide; Silane coupling agent 0.1-0.3 parts.

[0010] By adopting the above technical solution, a composite of melamine-formaldehyde resin and ethyl cellulose is selected as the capsule material for the thermochromic microcapsules. The melamine-formaldehyde resin provides structural support, imparting excellent heat resistance and mechanical strength to the microcapsules. Modification with environmentally friendly methanol reduces residual formaldehyde content. Ethyl cellulose improves the flexibility of the microcapsule material, further reducing formaldehyde release while providing a hydrophobic barrier. Nano-titanium dioxide and a silane coupling agent are used to modify the composite capsule material. Nano-titanium dioxide enhances UV resistance and resists UV exposure, while the silane coupling agent strengthens the bond between the nano-titanium dioxide and the capsule material and reduces nano-titanium dioxide aggregation, resulting in excellent UV and high temperature resistance for the microcapsule material, protecting the thermochromic material from failure.

[0011] Optionally, the thermochromic material is selected from one or more of crystal violet lactone-bisphenol A-hexadecanol, crystal violet lactone-bisphenol A-2-(4-benzyloxyphenyl)ethyl decanoate, tungsten trioxide, and salicylaldehyde acetylamino.

[0012] By adopting the above technical solution and selecting reversible thermochromic materials, the materials can undergo reversible color change at high and low temperatures, thereby achieving long-term use.

[0013] Optionally, the thermochromic material is a crystal violet lactone-bisphenol A-hexadecanol compound, and the mass ratio of crystal violet lactone, bisphenol A, and hexadecanol is 1:(4-5):(42-50).

[0014] By adopting the above technical solution, a crystal violet lactone-bisphenol A-hexadecanol compound is prepared as the core material using crystal violet lactone as the electron donor, bisphenol A as the electron acceptor, and hexadecanol as the solvent. This compound can display a specific color at a specific temperature, making the temperature state of the cable easier to inspect and observe.

[0015] Optionally, the sheath material specifically includes the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin; 13-17 parts of chlorinated polyethylene; 38-44 parts of plasticizer; 0.6-1.2 parts of antioxidant; 3-6 parts of maleic anhydride grafted polyethylene; 6-11 parts of nano ceramic powder; 5-9 parts of stabilizer; 0.8-1.5 parts of lubricant.

[0016] By adopting the above technical solution, polyvinyl chloride resin and chlorinated polyethylene are selected as the base material, maleic anhydride-grafted polyethylene is added as a compatibilizer to improve the compatibility between the sheath material and the thermochromic microcapsules, and nano-ceramic powder is used as a filler to enhance the high temperature resistance and mechanical properties of the cable sheath layer. With these raw materials, the prepared cable sheath has excellent mechanical properties, high temperature resistance, and weather resistance.

[0017] Optionally, the plasticizer is a mixture of trioctyl trimellitate and dioctyl terephthalate, wherein the mass ratio of trioctyl trimellitate to dioctyl terephthalate is (1.3-1.6):1.

[0018] By adopting the above technical solution and selecting a compound of two plasticizers, the flexibility of the sheath raw material during processing is improved, so that the high temperature resistance and tensile strength of the cable sheath are improved.

[0019] Optionally, the polyvinyl chloride resin is SG-3 polyvinyl chloride resin, and the chlorinated polyethylene is chlorinated polyethylene with a chlorine content of 35%-38% and a Mooney viscosity of 95-100.

[0020] The present application also discloses a method for preparing a thermochromic material cable, comprising the following steps: Copper wires with a diameter of 3.5 mm are twisted into a conductor, a wire sheath is coated on the outside of the conductor, and an insulation layer is coated on the outside of the wire sheath using an extrusion process to form an insulated wire core; An inner sheath is wrapped around the outside of the insulated wire core; The sheath material and thermochromic microcapsules are used to prepare the sheath layer material, and the sheath layer is coated on the outside of the inner sheath to form a thermochromic material cable.

[0021] By adopting the above technical solution, a thermochromic material cable including an insulating core, an inner sheath and a sheath layer is obtained by layer-by-layer coating, and the cable also has a high-temperature discoloration warning function.

[0022] Optionally, the sheath layer material is prepared by the following steps: Premixing polyvinyl chloride resin, chlorinated polyethylene, maleic anhydride grafted polyvinyl chloride and thermochromic microcapsules, stirring for 2-3 minutes, and then adding plasticizer, nano-ceramic powder, antioxidant, stabilizer and lubricant to form a mixture; The mixed material is added into a twin-screw extruder and melt-extruded to obtain the sheath layer material.

[0023] By adopting the above technical solution, the sheath layer material is prepared by heating, melting and then blending the base.

[0024] Optionally, the thermochromic microcapsules are prepared by the following steps: Preparation of capsule material: Melamine, paraformaldehyde, and water are weighed and added to a three-necked flask, and the pH of the system is adjusted to 7-8 with triethanolamine. Ethyl cellulose is then added, mixed evenly, and reacted at 70-75°C for 30-40 minutes to obtain a prepolymer. Methanol solution is added to the prepolymer for modification to obtain a modified prepolymer. Appropriate amounts of nano-titanium dioxide and a silane coupling agent are weighed and added to the modified prepolymer, and ultrasonic dispersion is performed to obtain a modified melamine-formaldehyde-ethyl cellulose capsule material. Emulsification of capsule core: Mix the thermochromic material, SMA emulsifier and water, and stir at high speed to emulsify and disperse to obtain an emulsion; In situ polymerization: Add modified melamine-formaldehyde-ethyl cellulose capsule material to the emulsion, adjust the pH to 5-6 with acid solution, heat and stir to 65-70℃ and react for 3.5-4h to obtain microcapsule suspension, cool to room temperature, wash with anhydrous ethanol and deionized water, filter under reduced pressure, and vacuum dry to obtain thermochromic microcapsules.

[0025] By adopting the above technical scheme and selecting the in-situ polymerization method, methanol, silane coupling agent and nano-titanium dioxide are first used to prepare the prepolymer in advance to obtain modified melamine-formaldehyde-ethyl cellulose, which is then compounded with the emulsified capsule core solution to prepare thermochromic microcapsules with good high temperature resistance and UV resistance.

[0026] In summary, this application has the following beneficial effects: 1. The thermochromic cable of this application incorporates thermochromic microcapsules into its sheath, which reversibly changes color at high temperatures, providing a high-temperature warning for the cable. The thermochromic microcapsules are evenly dispersed throughout the cable sheath. When a cable fault causes a local temperature rise, the temperature-sensitive material changes color, resulting in a uniform color change throughout the cable, further facilitating high-temperature indication and early warning.

[0027] Thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as the capsule material, which protects the capsule core of the thermochromic material. The capsule material is resistant to high temperatures and UV rays, so that during the long-term use of the cable, the thermochromic material will not age due to ultraviolet radiation or fail due to high temperatures, thereby extending the service life of the thermochromic microcapsules.

[0028] 2. When selecting the thermochromic microcapsule material, a compound of melamine-formaldehyde resin and ethyl cellulose is used. Melamine-formaldehyde resin provides structural support, giving the microcapsules excellent heat resistance and mechanical strength. Modification with environmentally friendly methanol can reduce the content of residual formaldehyde. Ethyl cellulose improves the flexibility of the microcapsule material, further reducing formaldehyde release while providing a hydrophobic barrier. Nano-titanium dioxide and a silane coupling agent are used to modify the composite capsule material. Nano-titanium dioxide can enhance UV resistance and resist ultraviolet light exposure. The silane coupling agent strengthens the bond between the nano-titanium dioxide and the capsule material and reduces nano-titanium dioxide aggregation, thus making the microcapsule material have excellent UV and high temperature resistance, protecting the thermochromic material from failure. DETAILED DESCRIPTION

[0029] The present application is further described in detail below with reference to the embodiments.

[0030] The present application discloses a thermochromic material cable comprising, from the outside in, a sheath layer, an inner sheath, and at least one insulated core, wherein the insulated core comprises, from the inside out, a conductor, a sheath, and an insulation layer. The conductor is formed by twisting copper wires, which are then coated with a sheath and an insulation layer to form an insulated core, and one or more insulated cores are uniformly coated with an inner sheath. The inner sheath may comprise one or more layers, such as a shielding layer, a filling layer, a waterproof layer, a flame retardant layer, or other multifunctional materials. The inner sheath is coated over the exterior of the insulated core by cross-braiding or extrusion.

[0031] The sheath layer is located at the outermost part of the cable. In the cable of the present application, thermochromic microcapsules are added to the sheath layer and co-extruded together with the sheath raw materials. Thermochromic microcapsules have the characteristic of changing color at a certain temperature, so the color of the sheath layer can be used to detect and display the cable temperature, thereby playing an early warning role.

[0032] The preparation method of the thermochromic material cable includes the following steps: Copper wires with a diameter of 3.5 mm are twisted into a conductor, a wire sheath is coated on the outside of the conductor, and an insulation layer is coated on the outside of the wire sheath using an extrusion process to form an insulated wire core; An inner sheath is wrapped around the outside of the insulated wire core; The sheath material and thermochromic microcapsules are used to prepare the sheath layer material, and the sheath layer is coated on the outside of the inner sheath to form a thermochromic material cable.

[0033] The following further describes the raw materials for the sheath layer of the thermochromic cable.

[0034] Preparation Example Preparation Example 1 Preparation of thermochromic microcapsules The thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as the capsule material and thermochromic material as the capsule core. The mass ratio of the capsule core to the capsule material is 2:1, and the average particle size is 0.3μm.

[0035] The capsule material includes the following raw materials: Melamine 6g, Paraformaldehyde 4g, Methanol 15g, Ethyl cellulose 2g, 0.7g of nano-titanium dioxide, with an average particle size of 30nm; 0.1 g of silane coupling agent, 3-aminopropyl-triethoxysilane was selected.

[0036] The thermochromic material is a crystal violet lactone-bisphenol A-hexadecanol compound, wherein the mass ratio of crystal violet lactone, bisphenol A and hexadecanol is 1:4:42.

[0037] The preparation method of thermochromic microcapsules comprises the following steps: Preparation of capsule material: Melamine, paraformaldehyde, and 32g of water were weighed and added to a three-necked flask. The pH of the system was adjusted to 7 with triethanolamine. Ethyl cellulose was then added, mixed uniformly, and reacted at 70°C for 40 minutes to obtain a prepolymer. Methanol was added to the prepolymer to modify it to obtain a modified prepolymer. Appropriate amounts of nano-titanium dioxide and a silane coupling agent were weighed and added to the modified prepolymer. The mixture was ultrasonically dispersed for 30 minutes to obtain a modified melamine-formaldehyde-ethyl cellulose capsule material. Emulsification of the capsule core: 49.7 g of hexadecanol was melted at 60°C, and 1.2 g of crystal violet lactone and 4.7 g of bisphenol A were added. The temperature was raised to 90°C and stirred for 2 h. After cooling, the thermochromic material was obtained. The thermochromic material was then mixed with 30 g of SMA emulsifier and 120 g of water and emulsified and dispersed with high-speed stirring to obtain an emulsion. In situ polymerization: Add modified melamine-formaldehyde-ethyl cellulose capsule material to the emulsion, adjust the pH to 5 with acid solution, heat and stir to 65℃ for 4 hours to obtain microcapsule suspension, cool to room temperature, wash with anhydrous ethanol and deionized water, filter under reduced pressure, and vacuum dry to obtain thermochromic microcapsules.

[0038] Preparation Example 2 Preparation of thermochromic microcapsules The thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as the capsule material and thermochromic material as the capsule core. The mass ratio of the capsule core to the capsule material is 2:1, and the average particle size is 0.7 μm.

[0039] The capsule material includes the following raw materials: Melamine 9g, Paraformaldehyde 6g, Methanol 21g, Ethyl cellulose 4g, 1.3g of nano-titanium dioxide, with an average particle size of 30nm; 0.3 g of silane coupling agent, 3-aminopropyl-triethoxysilane was selected.

[0040] The thermochromic material is a crystal violet lactone-bisphenol A-2-(4-benzyloxyphenyl) ethyl decanoate compound, wherein the mass ratio of crystal violet lactone, bisphenol A and 2-(4-benzyloxyphenyl) ethyl decanoate is prepared according to a ratio of 1:4:40.

[0041] The preparation method of thermochromic microcapsules comprises the following steps: Preparation of capsule material: Melamine, paraformaldehyde, and 50g of water were weighed and added to a three-necked flask. The pH of the system was adjusted to 8 with triethanolamine. Ethyl cellulose was then added, mixed evenly, and reacted at 75°C for 30 minutes to obtain a prepolymer. Methanol was added to the prepolymer to modify it to obtain a modified prepolymer. Appropriate amounts of nano-titanium dioxide and a silane coupling agent were weighed and added to the modified prepolymer. The mixture was ultrasonically dispersed for 50 minutes to obtain a modified melamine-formaldehyde-ethyl cellulose capsule material. Emulsification of the capsule core: 73.96 g of hexadecanol was melted at 62°C, and 1.85 g of crystal violet lactone and 7.39 g of bisphenol A were added. The temperature was raised to 95°C and stirred for 2 h. After cooling, the thermochromic material was obtained. The thermochromic material was then mixed with 42 g of SMA emulsifier and 150 g of water and emulsified and dispersed with high-speed stirring to obtain an emulsion. In situ polymerization: Add modified melamine-formaldehyde-ethyl cellulose capsule material to the emulsion, adjust the pH to 6 with acid solution, heat and stir to 70℃ and react for 3.5h to obtain microcapsule suspension, cool to room temperature, wash with anhydrous ethanol and deionized water, filter under reduced pressure, and vacuum dry to obtain thermochromic microcapsules.

[0042] Preparation Example 3 Preparation of thermochromic microcapsules The thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as the capsule material and thermochromic material as the capsule core. The mass ratio of the capsule core to the capsule material is 2.5:1, and the average particle size is 0.5 μm.

[0043] The capsule material includes the following raw materials: Melamine 7g, Paraformaldehyde 5g, Methanol 18g, Ethyl cellulose 3g, 1g of nano-titanium dioxide, with an average particle size of 30nm; 0.2 g of silane coupling agent, 3-aminopropyl-triethoxysilane was selected.

[0044] The thermochromic material is a crystal violet lactone-bisphenol A-hexadecanol compound, wherein the mass ratio of crystal violet lactone, bisphenol A and hexadecanol is 1:5:50.

[0045] The preparation method of thermochromic microcapsules comprises the following steps: Preparation of capsule material: Melamine, paraformaldehyde, and 40g of water were weighed and added to a three-necked flask. The pH of the system was adjusted to 7 with triethanolamine. Ethyl cellulose was then added, mixed uniformly, and reacted at 70°C for 40 minutes to obtain a prepolymer. Methanol was added to the prepolymer to modify it to obtain a modified prepolymer. Appropriate amounts of nano-titanium dioxide and a silane coupling agent were weighed and added to the modified prepolymer. The mixture was ultrasonically dispersed for 30 minutes to obtain a modified melamine-formaldehyde-ethyl cellulose capsule material. Emulsification of the capsule core: 76.3 g of hexadecanol was melted at 60°C, and 1.53 g of crystal violet lactone and 7.65 g of bisphenol A were added. The temperature was raised to 90°C and stirred for 2 h. After cooling, the thermochromic material was obtained. The thermochromic material was then mixed with 48 g of SMA emulsifier and 170 g of water and emulsified and dispersed with high-speed stirring to obtain an emulsion. In situ polymerization: Add modified melamine-formaldehyde-ethyl cellulose capsule material to the emulsion, adjust the pH to 5 with acid solution, heat and stir to 65℃ for 4 hours to obtain microcapsule suspension, cool to room temperature, wash with anhydrous ethanol and deionized water, filter under reduced pressure, and vacuum dry to obtain thermochromic microcapsules. Example

[0046] Example 1 The sheath layer includes the following raw materials: 166.4 kg of sheath raw material and 1.2 kg of thermochromic microcapsules prepared in Preparation Example 1.

[0047] The sheath materials specifically include the following materials: 100kg of polyvinyl chloride resin, SG-3 type polyvinyl chloride resin is selected; 13kg of chlorinated polyethylene, with a chlorine content of 35% and a Mooney viscosity of 95; 38kg of plasticizer, trioctyl trimellitate is used as the plasticizer; 0.6kg antioxidant, antioxidant 1010 is selected; 3kg of maleic anhydride grafted polyethylene, brand ZJ-900E, from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; 6kg of nano-ceramic powder, with a particle size of 10-30nm; 5kg of stabilizer, calcium zinc stabilizer is used; 0.8kg lubricant, paraffin wax is used.

[0048] The sheath layer is prepared by the following steps: Polyvinyl chloride resin, chlorinated polyethylene, maleic anhydride grafted polyvinyl chloride and thermochromic microcapsules are premixed and stirred for 2 minutes, and then plasticizer, nano-ceramic powder, antioxidant, stabilizer and lubricant are added and mixed to form a mixture; the mixture is added into a twin-screw extruder and melt-extruded to obtain a sheath layer material.

[0049] Example 2 The sheath layer includes the following raw materials: 189.7 kg of sheath raw material and 2 kg of thermochromic microcapsules prepared in Preparation Example 2.

[0050] The sheath materials specifically include the following materials: 100kg of polyvinyl chloride resin, SG-3 type polyvinyl chloride resin is selected; 17kg of chlorinated polyethylene, with a chlorine content of 35% and a Mooney viscosity of 95; 44kg of plasticizer, trioctyl trimellitate is used as the plasticizer; 1.2kg antioxidant, antioxidant 1010 is selected; 6 kg of maleic anhydride grafted polyethylene, using the maleic anhydride grafted polyethylene brand ZJ-900E from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; 11kg of nano-ceramic powder, with a particle size of 10-30nm; 9kg of stabilizer, calcium zinc stabilizer is used; 1.5kg lubricant, paraffin wax is used.

[0051] The sheath layer is prepared by the following steps: Premixing polyvinyl chloride resin, chlorinated polyethylene, maleic anhydride grafted polyvinyl chloride and thermochromic microcapsules, stirring for 3 minutes, and then adding plasticizer, nano-ceramic powder, antioxidant, stabilizer and lubricant to form a mixture; The mixed material is added into a twin-screw extruder and melt-extruded to obtain the sheath layer material.

[0052] Example 3 The sheath layer includes the following raw materials: 166.4 kg of sheath raw material and 1.5 kg of the thermochromic microcapsules prepared in Preparation Example 3.

[0053] The sheath materials specifically include the following materials: 100kg of polyvinyl chloride resin, SG-3 type polyvinyl chloride resin is selected; 13kg of chlorinated polyethylene, with a chlorine content of 38% and a Mooney viscosity of 100; 38kg plasticizer, dioctyl terephthalate is used as the plasticizer; 0.6kg antioxidant, antioxidant 1076 is selected; 3kg of maleic anhydride grafted polyethylene, brand ZJ-900E, from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; 6kg of nano-ceramic powder, with a particle size of 10-30nm; 5kg of stabilizer, calcium zinc stabilizer is used; Lubricant 0.8kg, zinc stearate is selected.

[0054] Example 4 The difference between this embodiment and embodiment 1 is that there are differences in the plasticizer raw materials in the sheathing material of the sheath layer.

[0055] The plasticizer in this embodiment is a mixture of trioctyl trimellitate and dioctyl terephthalate, wherein the trioctyl trimellitate is 21.5 kg and the dioctyl terephthalate is 16.5 kg.

[0056] Example 5 The difference between this embodiment and embodiment 1 is that there are differences in the plasticizer raw materials in the sheathing material of the sheath layer.

[0057] The plasticizer in this embodiment is a mixture of trioctyl trimellitate and dioctyl terephthalate, wherein the mixture contains 23.3 kg of trioctyl trimellitate and 14.7 kg of dioctyl terephthalate.

[0058] Comparative Example Comparative Example 1 The difference between this comparative example and Example 1 is that in the sheath layer, an equal mass of thermochromic powder is used instead of the thermochromic microcapsules in Example 1. The thermochromic powder is purchased from Anhui Jingzhicai New Materials Co., Ltd. and the model is Runba WS0066.

[0059] Comparative Example 2 The difference between this comparative example and Example 1 is that the capsule materials in the thermochromic microcapsules in the sheath layer are different.

[0060] In this comparative example, the capsule material of the thermochromic microcapsules is unmodified melamine-formaldehyde-ethyl cellulose, the thermochromic material is used as the capsule core, and the mass ratio of the capsule core to the capsule material is 2:1.

[0061] The capsule material comprises the following raw materials in parts by weight: Melamine 6g, Paraformaldehyde 4g, Ethyl cellulose 2g.

[0062] The thermochromic material is a crystal violet lactone-bisphenol A-hexadecanol compound, and the mass ratio of crystal violet lactone, bisphenol A and hexadecanol is 1:4:42.

[0063] The sheath layer raw materials prepared in Examples 1-5 and Comparative Examples 1-2 were coated on the outside of the inner sheath to prepare a thermochromic material cable, and the performance of the cable was tested.

[0064] Tensile strength: The tensile strength was determined according to the method in GB / T 8815-2008 "Soft polyvinyl chloride plastics for wires and cables".

[0065] High temperature resistance: Place the jacket layer sample in an air oven at 120°C for 7 days, take it out and cool it down, test whether the thermochromic microcapsules of the jacket layer sample can still reversibly change color, and test the tensile strength again.

[0066] UV aging resistance: The sheath layer sample was irradiated with ultraviolet light using a fluorescent lamp. The fluorescent lamp used was a UV-A type ultraviolet lamp with a radiation energy peak of 340nm. The ultraviolet exposure temperature was 50°C and the exposure time was 7 days. The test was conducted to see whether the thermochromic microcapsules of the sheath layer sample could still reversibly change color.

[0067] The above results are recorded in Table 1.

[0068] Table 1 The above test data demonstrates that the thermochromic cable prepared in this application, through the selection of sheath material and the preparation and modification of thermochromic microcapsules, has a cable sheath with good tensile strength, as well as excellent resistance to high temperatures and UV aging. The thermochromic microcapsules have a longer service life at high temperatures and under UV irradiation, thus providing a high-temperature early warning for the cable.

[0069] By comparison with Comparative Examples 1 and 2, the present application microencapsulates the thermochromic material and selects nano-titanium dioxide and silane coupling agent to modify the capsule material to improve the anti-ultraviolet and high-temperature resistance, so that the internal capsule core is protected by the capsule material, so that the internal thermochromic material will not fail.

[0070] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A thermochromic cable, characterized in that: The invention comprises at least one insulated wire core, the outer surface of the insulated wire core is covered with an inner sheath, the outer surface of the inner sheath is covered with a sheath, the insulated wire core comprises a conductor, a sheath and an insulating layer from the inside to the outside, and the sheath comprises the following raw materials in parts by weight: 140-210 parts of sheath raw material; 1-2.2 parts of thermochromic microcapsules; Among them, the sheath material is made of polyvinyl chloride resin as the base material; The thermochromic microcapsules use modified melamine-formaldehyde-ethyl cellulose as capsule material and thermochromic material as capsule core. The mass ratio of capsule core to capsule material is (2-2.5):1, and the average particle size is 0.3-0.7μm.

2. The thermochromic cable according to claim 1, characterized in that: The modified melamine-formaldehyde-ethyl cellulose comprises the following raw materials in parts by weight: 6-9 parts of melamine; 4-6 parts of paraformaldehyde; 15-21 parts of methanol; 2-4 parts of ethyl cellulose; 0.7-1.3 parts of nano titanium dioxide; Silane coupling agent 0.1-0.3 parts.

3. The thermochromic cable according to claim 1, characterized in that: The thermochromic material is selected from one or more of crystal violet lactone-bisphenol A-hexadecanol, crystal violet lactone-bisphenol A-2-(4-benzyloxyphenyl)ethyldecanoate, tungsten trioxide, and salicylaldehyde acetylamino.

4. The thermochromic cable according to claim 3, characterized in that: The thermochromic material is a mixture of crystal violet lactone, bisphenol A and hexadecanol, and the mass ratio of crystal violet lactone, bisphenol A and hexadecanol is 1:(4-5):(42-50).

5. The thermochromic cable according to claim 1, characterized in that: The sheath raw materials specifically include the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin; 13-17 parts of chlorinated polyethylene; 38-44 parts of plasticizer; 0.6-1.2 parts of antioxidant; 3-6 parts of maleic anhydride grafted polyethylene; 6-11 parts of nano ceramic powder; 5-9 parts of stabilizer; 0.8-1.5 parts of lubricant.

6. The thermochromic cable according to claim 5, characterized in that: The plasticizer is a mixture of trioctyl trimellitate and dioctyl terephthalate, wherein the mass ratio of trioctyl trimellitate to dioctyl terephthalate is (1.3-1.6):

1.

7. The thermochromic cable according to claim 5, characterized in that: The polyvinyl chloride resin is SG-3 type polyvinyl chloride resin, and the chlorinated polyethylene is chlorinated polyethylene with a chlorine content of 35%-38% and a Mooney viscosity of 95-100.

8. The method for preparing a thermochromic material cable according to any one of claims 1 to 7, characterized in that: The following steps are involved: Copper wires with a diameter of 3.5 mm are twisted into a conductor, a wire sheath is coated on the outside of the conductor, and an insulation layer is coated on the outside of the wire sheath using an extrusion process to form an insulated wire core; An inner sheath is wrapped around the outside of the insulated wire core; The sheath material and thermochromic microcapsules are used to prepare the sheath layer material, and the sheath layer is coated on the outside of the inner sheath to form a thermochromic material cable.

9. The method for preparing a thermochromic material cable according to claim 8, characterized in that: The sheath material is prepared by the following steps: Premixing polyvinyl chloride resin, chlorinated polyethylene, maleic anhydride grafted polyvinyl chloride and thermochromic microcapsules, stirring for 2-3 minutes, and then adding plasticizer, nano-ceramic powder, antioxidant, stabilizer and lubricant to form a mixture; The mixed material is added into a twin-screw extruder and melt-extruded to obtain the sheath layer material.

10. The method for preparing a thermochromic material cable according to claim 8, characterized in that: Thermochromic microcapsules are prepared by the following steps: Preparation of capsule material: Melamine, paraformaldehyde, and water are weighed and added to a three-necked flask, and the pH of the system is adjusted to 7-8 with triethanolamine. Ethyl cellulose is then added, mixed evenly, and reacted at 70-75°C for 30-40 minutes to obtain a prepolymer. Methanol solution is added to the prepolymer for modification to obtain a modified prepolymer. Appropriate amounts of nano-titanium dioxide and a silane coupling agent are weighed and added to the modified prepolymer, and ultrasonic dispersion is performed to obtain a modified melamine-formaldehyde-ethyl cellulose capsule material. Emulsification of capsule core: Mix the thermochromic material, SMA emulsifier and water, and stir at high speed to emulsify and disperse to obtain an emulsion; In situ polymerization: Add modified melamine-formaldehyde-ethyl cellulose capsule material to the emulsion, adjust the pH to 5-6 with acid solution, heat and stir to 65-70℃ and react for 3.5-4h to obtain microcapsule suspension, cool to room temperature, wash with anhydrous ethanol and deionized water, filter under reduced pressure, and vacuum dry to obtain thermochromic microcapsules.

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