High flame-retardant electronic connecting wire and preparation method thereof

Abstract

The application relates to a high-flame-retardant electronic connecting wire and a preparation method thereof, and belongs to the technical field of high polymer materials. The electronic connecting wire is composed of a wire and a surface flame-retardant protective layer, wherein the components of the flame-retardant protective layer are as follows: modified phosphorus-silicon flame retardant 7.5-10 wt%, plasticizer 14-18 wt%, heat stabilizer 1.7-2.2 wt%, antioxidant 0.12-0.16 wt% and lubricant 0.9-1.3 wt%, and the rest is PVC resin; the modified phosphorus-silicon flame retardant is synthesized by synthesizing a phosphorus oxychloride intermediate 1 with a double spiro ring structure from pentaerythritol and phosphorus oxychloride, carrying out amine-ester exchange between terminal amino polydimethylsiloxane and ketone-based diethyl malonate to prepare an intermediate 2 containing terminal amino groups, and then reacting the intermediate 2 with active phosphorus oxychloride of the intermediate 1 to form a chain-shaped macromolecular phosphorus amide compound, so that in-situ toughening, migration inhibition and carbon net flame retardation are simultaneously realized in the PVC matrix.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically, it relates to a highly flame-retardant electronic interconnect wire and its preparation method. Background Technology

[0002] Electronic connectors are fundamental components in modern electronic equipment, power systems, and communication networks, and their safety and reliability are of paramount importance. Fire is one of the main safety hazards of electrical equipment; therefore, the flame-retardant properties of the connector insulation material have become a core indicator for assessing its safety level. Currently, polyvinyl chloride (PVC) remains the mainstream material for electronic connector insulation due to its excellent electrical insulation properties, processing performance, chemical corrosion resistance, and relatively low cost.

[0003] However, traditional PVC-based electronic connectors have significant shortcomings in flame retardant performance, especially in applications requiring higher flame retardant ratings, where their performance is often less than ideal. This is mainly due to the following key factors:

[0004] Reduced flame retardancy due to plasticizers: To meet the flexibility required for electronic wiring during installation and use, a large amount of plasticizers must be added to the PVC base material. These plasticizers are usually flammable or combustible small organic molecules that dilute the chlorine inherent in the PVC resin, reducing char formation efficiency and thus severely weakening the overall flame retardant performance of the PVC insulation layer.

[0005] Hazards of molten droplets and smoke during combustion: When PVC is heated and burns, it easily produces high-temperature molten droplets. These droplets not only carry flames themselves, posing a risk of igniting combustibles below and spreading the fire, but may also cause secondary damage to precision electronic components. Furthermore, burning PVC releases large amounts of dense and corrosive black smoke containing toxic gases such as hydrogen chloride. This smoke not only severely hinders personnel escape and fire rescue efforts, but also corrodes equipment, causing even greater secondary disasters.

[0006] To improve the flame retardant properties of PVC connectors, the industry commonly uses the method of adding flame retardants. Commonly used flame retardants mainly fall into two categories: inorganic and organic. However, both face significant challenges when applied to flexible PVC electronic connectors.

[0007] Inorganic flame retardants offer high flame retardant efficiency, significant smoke suppression, low toxicity, environmental friendliness, and low cost. However, the amount required to achieve an effective flame retardant level is typically very high. Such a high proportion of filler severely damages the mechanical properties of the PVC insulation layer, leading to severe material embrittlement, a sharp decrease in flexibility, deterioration of tensile and impact resistance, and even affecting extrusion processing performance. This is a fatal flaw for flexible electronic connecting wires that require frequent bending and insertion / removal, easily causing cracking, detachment, and loss of protection for the conductor.

[0008] Organic flame retardants offer high flame retardancy and have relatively little impact on the physical and mechanical properties of materials, especially toughness, thus effectively maintaining the flexibility and processing fluidity required for soft PVC. However, they exhibit a greater tendency to migrate and exudate, exacerbating dripping during combustion and increasing the risk of ignition.

[0009] Therefore, developing a novel flame-retardant system and its corresponding preparation method, which can be effectively applied to the insulation layer of flexible electronic connecting wires, while maintaining excellent flexibility and processing performance, to achieve a high level of flame-retardant protection with high efficiency, low smoke, and no dripping, has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0010] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a high flame retardant electronic connecting wire and its preparation method.

[0011] The objective of this invention can be achieved through the following technical solutions:

[0012] A high flame-retardant electronic connection wire is composed of a conductor and a flame-retardant protective layer on the surface. The flame-retardant protective layer is composed of: 7.5-10 wt% modified phosphorus silicon flame retardant, 14-18 wt% plasticizer, 1.7-2.2 wt% heat stabilizer, 0.12-0.16 wt% antioxidant, and 0.9-1.3 wt% lubricant, with the balance being PVC resin.

[0013] The modified phosphorus-silicon flame retardant is prepared by the following method:

[0014] Step A1: Pentaerythritol and anhydrous dioxane are heated and mixed, and dry nitrogen gas is introduced for protection. The temperature is controlled at 70-80℃. Phosphorus oxychloride is slowly added and stirred for 4-4.5 hours. Then the pressure is increased to 5.5-6.5 bar, and the temperature is further increased to 120-130℃ for 1.5-2 hours. After the reaction is completed, dioxane is removed by rotary evaporation to obtain intermediate 1.

[0015] In step A1, the feed ratio of pentaerythritol, phosphorus oxychloride, and anhydrous dioxane is 0.1 mol: 0.2 mol: 180-220 mL. Pentaerythritol and phosphorus oxychloride are esterified to form a phosphate ester compound containing a bispiral ring. The specific reaction route is as follows:

[0016]

[0017] Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane and anhydrous toluene, purge with dry nitrogen, heat to 80-90℃, add trimethylaluminum and stir for 2-3 hours. After the reaction is complete, remove toluene by rotary evaporation to obtain intermediate 2.

[0018] In step A2, the feed ratio of diethyl ketomalonate, amino-terminated polydimethylsiloxane, trimethylaluminum, and anhydrous toluene is 0.1 mol: 0.403-0.405 mol: 60-80 mg: 420-500 mL. Diethyl ketomalonate and amino-terminated polydimethylsiloxane undergo an amino-ester exchange reaction. The specific reaction route is as follows:

[0019]

[0020] Preferably, the room temperature viscosity of the amino-terminated polydimethylsiloxane is not higher than 20 mm. 2 The low viscosity raw materials have low molecular weight and high reactivity, resulting in a more uniform distribution of phosphorus and silicon segments in the molecular chain of the modified phosphorus and silicon flame retardant, and a more stable carbon network formed at high temperatures.

[0021] Step A3: Premix intermediate 2 and dimethylacetamide, purge with dry nitrogen, add intermediate 1, mix and heat to 40-55℃ and stir for 6-10 h, then add triethylamine and reduce pressure to 100 Pa, continue heating to 140-150℃ and continue reacting for 2-2.5 h, after the reaction is completed, add deionized water to wash, separate the aqueous phase and dry to obtain the modified phosphorus silicon flame retardant;

[0022] In step A3, the amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1 mol: 0.2 mol: 25-30 mL: 350-400 mL. Intermediate 1 and intermediate 2 undergo an amidation reaction to form a polymer. The specific reaction route is as follows:

[0023]

[0024] Preferably, the plasticizer is epoxidized soybean oil, which has good compatibility with both the PVC matrix and the modified phosphorus-silicon flame retardant components, reducing the formation of incompatible interfaces and helping to maintain the overall mechanical properties of the composite system.

[0025] Preferably, the lubricant is a combination of low-density polyethylene wax and calcium stearate, which effectively improves the fluidity of the melt, facilitates the full mixing of the modified phosphorus silicon flame retardant with the PVC matrix, and also provides internal and external lubrication, which helps to improve the molding quality of the flame-retardant protective layer.

[0026] A method for preparing a highly flame-retardant electronic connecting wire, specifically comprising:

[0027] Step S1: Mix the raw materials of each component evenly, then plasticize and knead the mixture using a twin-screw extruder, and then extrude and granulate it to obtain flame retardant masterbatch;

[0028] Step S2: The flame-retardant masterbatch is coated onto the surface of the wire using a single-screw extruder. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

[0029] The beneficial effects of this invention are:

[0030] This invention synthesizes a modified phosphorosilicon flame retardant blended with PVC to prepare an insulating protective layer for electronic interconnects. The modified phosphorosilicon flame retardant is synthesized from pentaerythritol and phosphorus oxychloride to form a phosphoryl chloride intermediate 1 with a double-spirocyclic structure. An amino-terminated polydimethylsiloxane is subjected to amine exchange with diethyl ketomalonate to produce an amino-terminated intermediate 2. Intermediate 2 then reacts with the active phosphoryl chloride of intermediate 1 to form a chain-like macromolecular phosphoramide compound, which is the modified phosphorosilicon flame retardant. Compared with existing flame retardant systems, this invention has the following advantages: First, the modified phosphorosilicon flame retardant itself has a macromolecular chain structure, exhibiting strong heat resistance and migration resistance. Second, the polycarbonyl groups on the modified phosphorosilicon flame retardant molecule form a dipole-dipole interaction with the chlorine groups on the PVC macromolecule, resulting in entanglement between the modified phosphorosilicon flame retardant macromolecule and the PVC macromolecule. This enhances migration resistance, and the phosphorus-containing double-spirocyclic structure introduced by intermediate 1 forms a large spatial structure. Under the dipole entanglement, it embeds into the interchain segments of the PVC. The modified phosphorus-silicon flame retardant weakens intermolecular forces, resulting in a good self-toughening effect. Thirdly, the modified phosphorus-silicon flame retardant has an ordered phosphorus-containing double spirocyclic structure-organosilicon structure. In a fire, the phosphorus double spirocyclic structure preferentially decomposes, promoting the carbonization of the PVC chains in its entangled segments to form carbon particles. These high-temperature resistant carbon particles are connected by a high-temperature resistant silicon structure, thus forming a flame-retardant carbon network of countless carbon particles in space. This flame-retardant carbon network hinders the penetration of combustion and inhibits the release of smoke and the generation of softened PVC droplets, thus exhibiting excellent flame-retardant effects. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: Preparation of highly flame-retardant electronic connecting wires. The specific implementation process is as follows:

[0033] (1) Preparation of modified phosphorus silicon flame retardant

[0034] Step A1: Mix pentaerythritol and anhydrous dioxane at a heated temperature, purge with dry nitrogen for protection, control the temperature at 70°C, slowly add phosphorus oxychloride and stir for 4.5 h, then continue to purge with nitrogen to pressurize to 5.5 bar, and continue to heat to 120°C for 2 h. The feed ratio of pentaerythritol, phosphorus oxychloride and anhydrous dioxane is 0.1 mol: 0.2 mol: 180 mL. After the reaction is complete, remove dioxane by rotary evaporation to obtain intermediate 1.

[0035] Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane, and anhydrous toluene. Purge with dry nitrogen for protection, heat to 80°C, add trimethylaluminum, and stir for 3 hours. The amino-terminated polydimethylsiloxane used is commercially available Cheersil 8110, with a room temperature viscosity of approximately 15 mmHg. 2 / s, the feed ratio of diethyl ketomalonate, amino-terminated polydimethylsiloxane, trimethylaluminum and anhydrous toluene is 0.1mol:0.403mol:60mg:420mL. After the reaction is completed, toluene is removed by rotary evaporation to obtain intermediate 2.

[0036] Step A3: Take intermediate 2 and dimethylacetamide premixed, purge with dry nitrogen, add intermediate 1, mix and heat to 40℃ and stir for 10h, then add triethylamine and reduce the pressure to 100Pa, continue heating to 140℃ and continue reacting for 2.5h. The amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1mol:0.2mol:25mL:350mL. After the reaction is completed, add deionized water to wash, separate the aqueous phase and dry to obtain the modified phosphorus silicon flame retardant.

[0037] (2) Preparation of electronic connecting wires

[0038] Step S1: The raw materials are calculated according to the following weight percentages: 7.5 wt% modified phosphorus-silicon flame retardant, which is self-made in this embodiment; 18 wt% plasticizer, which is commercially available epoxidized soybean oil plasticizer; 1.7 wt% heat stabilizer, which is commercially available GP-182 type calcium-zinc composite heat stabilizer; 0.16 wt% antioxidant, which is commercially available antioxidant 1010 and antioxidant 168 used in equal weight ratios; 1.3 wt% lubricant, which is commercially available CERALENE® 2T type low-density polyethylene wax and industrial grade calcium stearate used in a weight ratio of 2:1; the balance is PVC resin, which is SG-3 type resin raw material. All components are added to a high-speed mixer and mixed evenly. The mixture is plasticized and mixed at 180°C using a twin-screw extruder, and then extruded and granulated to obtain flame retardant masterbatch.

[0039] Step S2: The flame-retardant masterbatch is extruded at 180°C using a single-screw extruder and coated onto the surface of the conductor. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

[0040] Example 2: Preparation of highly flame-retardant electronic connecting wires. The specific implementation process is as follows:

[0041] (1) Preparation of modified phosphorus silicon flame retardant

[0042] Step A1: Mix pentaerythritol and anhydrous dioxane at a heated temperature, purge with dry nitrogen for protection, control the temperature at 80°C, slowly add phosphorus oxychloride and stir for 4 hours, then continue to purge with nitrogen to pressurize to 6 bar, and continue to heat to 125°C for 1.7 hours. The feed ratio of pentaerythritol, phosphorus oxychloride and anhydrous dioxane is 0.1 mol: 0.2 mol: 200 mL. After the reaction is complete, remove dioxane by rotary evaporation to obtain intermediate 1.

[0043] Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane, and anhydrous toluene. Purge with dry nitrogen for protection, heat to 85°C, add trimethylaluminum, and stir for 2.5 hours. The amino-terminated polydimethylsiloxane used is commercially available Cheersil 8110, with a room temperature viscosity of approximately 15 mmHg. 2 / s, the feed ratio of diethyl ketomalonate, amino-terminated polydimethylsiloxane, trimethylaluminum and anhydrous toluene is 0.1mol:0.404mol:70mg:450mL. After the reaction is completed, toluene is removed by rotary evaporation to obtain intermediate 2.

[0044] Step A3: Take intermediate 2 and dimethylacetamide premixed, purge with dry nitrogen, add intermediate 1, mix and heat to 50℃ and stir for 7h, then add triethylamine and reduce the pressure to 100Pa, continue heating to 150℃ and continue reacting for 2.2h. The amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1mol:0.2mol:28mL:370mL. After the reaction is completed, add deionized water to wash, separate the aqueous phase and dry to obtain the modified phosphorus silicon flame retardant.

[0045] (2) Preparation of electronic connecting wires

[0046] Step S1: The raw materials are calculated according to the following weight percentages: 9.2 wt% modified phosphorus-silicon flame retardant, which is self-made in this embodiment; 15 wt% plasticizer, which is commercially available epoxidized soybean oil plasticizer; 2 wt% heat stabilizer, which is commercially available GP-182 type calcium-zinc composite heat stabilizer; 0.13 wt% antioxidant, which is commercially available antioxidant 1010 and antioxidant 168 used in equal weight ratios; 1.1 wt% lubricant, which is commercially available CERALENE® 2T type low-density polyethylene wax and industrial grade calcium stearate used in a weight ratio of 2:1; the balance is PVC resin, which is SG-3 type resin raw material. All components are added to a high-speed mixer and mixed evenly. The mixture is plasticized and mixed using a twin-screw extruder at 170°C, and then extruded and granulated to obtain flame retardant masterbatch.

[0047] Step S2: The flame-retardant masterbatch is extruded at 180°C using a single-screw extruder and coated onto the surface of the conductor. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

[0048] Example 3: Preparation of highly flame-retardant electronic connecting wires. The specific implementation process is as follows:

[0049] (1) Preparation of modified phosphorus silicon flame retardant

[0050] Step A1: Mix pentaerythritol and anhydrous dioxane at a heated temperature, purge with dry nitrogen for protection, control the temperature at 80°C, slowly add phosphorus oxychloride and stir for 4 hours, then continue to purge with nitrogen to pressurize to 6.5 bar, and continue to heat to 130°C for 1.5 hours. The feed ratio of pentaerythritol, phosphorus oxychloride and anhydrous dioxane is 0.1 mol: 0.2 mol: 220 mL. After the reaction is complete, remove dioxane by rotary evaporation to obtain intermediate 1.

[0051] Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane, and anhydrous toluene. Purge with dry nitrogen for protection, heat to 90°C, add trimethylaluminum, and stir for 2 hours. The amino-terminated polydimethylsiloxane used is commercially available Cheersil 8110, with a room temperature viscosity of approximately 15 mmHg. 2 / s, the ratio of ketodiethyl malonate, amino-terminated polydimethylsiloxane, trimethylaluminum and anhydrous toluene was 0.1mol:0.405mol:80mg:500mL. After the reaction was completed, toluene was removed by rotary evaporation to obtain intermediate 2.

[0052] Step A3: Take intermediate 2 and dimethylacetamide premixed, purge with dry nitrogen, add intermediate 1, mix and heat to 55℃ and stir for 6h, then add triethylamine and reduce pressure to 100Pa, continue heating to 150℃ and continue reacting for 2h. The amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1mol:0.2mol:30mL:400mL. After the reaction is completed, add deionized water to wash, separate the aqueous phase and dry to obtain the modified phosphorus silicon flame retardant.

[0053] (2) Preparation of electronic connecting wires

[0054] Step S1: The raw materials are calculated according to the following weight percentages: 10 wt% modified phosphorus-silicon flame retardant, which is self-made in this embodiment; 14 wt% plasticizer, which is commercially available epoxidized soybean oil plasticizer; 2.2 wt% heat stabilizer, which is commercially available GP-182 type calcium-zinc composite heat stabilizer; 0.12 wt% antioxidant, which is commercially available antioxidant 1010 and antioxidant 168 used in equal weight ratios; 0.9 wt% lubricant, which is commercially available CERALENE® 2T type low-density polyethylene wax and industrial grade calcium stearate used in a weight ratio of 2:1; the balance is PVC resin, which is SG-3 type resin raw material. The raw materials are added to a high-speed mixer and mixed evenly. The mixture is plasticized and mixed using a twin-screw extruder at 170°C, and then extruded and granulated to obtain flame retardant masterbatch.

[0055] Step S2: The flame-retardant masterbatch is extruded at 180°C using a single-screw extruder and coated onto the surface of the conductor. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

[0056] Example 4: Preparation of highly flame-retardant electronic connecting wires. The specific implementation process is as follows:

[0057] (1) Preparation of modified phosphorus silicon flame retardant

[0058] Step A1: Mix pentaerythritol and anhydrous dioxane at a heated temperature, purge with dry nitrogen for protection, control the temperature at 75°C, slowly add phosphorus oxychloride and stir for 4.5 h, then continue to purge with nitrogen to pressurize to 6 bar, and continue to heat to 120°C for 1.8 h. The feed ratio of pentaerythritol, phosphorus oxychloride and anhydrous dioxane is 0.1 mol: 0.2 mol: 210 mL. After the reaction is complete, remove dioxane by rotary evaporation to obtain intermediate 1.

[0059] Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane, and anhydrous toluene. Purge with dry nitrogen for protection, heat to 80°C, add trimethylaluminum, and stir for 2.5 hours. The amino-terminated polydimethylsiloxane used is commercially available Cheersil 8110, with a room temperature viscosity of approximately 15 mmHg. 2 / s, the feed ratio of diethyl ketomalonate, amino-terminated polydimethylsiloxane, trimethylaluminum and anhydrous toluene is 0.1mol:0.405mol:75mg:460mL. After the reaction is completed, toluene is removed by rotary evaporation to obtain intermediate 2.

[0060] Step A3: Take intermediate 2 and dimethylacetamide premixed, purge with dry nitrogen, add intermediate 1, mix and heat to 45℃ and stir for 8.5h. Then add triethylamine and reduce the pressure to 100Pa, continue heating to 140℃ and continue reacting for 2.5h. The amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1mol:0.2mol:30mL:380mL. After the reaction is completed, add deionized water to wash, separate the aqueous phase and dry to obtain the modified phosphorus silicon flame retardant.

[0061] (2) Preparation of electronic connecting wires

[0062] Step S1: The raw materials are calculated according to the following weight percentages: 8.8 wt% modified phosphorus-silicon flame retardant, which is self-made in this embodiment; 16 wt% plasticizer, which is commercially available epoxidized soybean oil plasticizer; 1.9 wt% heat stabilizer, which is commercially available GP-182 type calcium-zinc composite heat stabilizer; 0.15 wt% antioxidant, which is commercially available antioxidant 1010 and antioxidant 168 used in equal weight ratios; 1.2 wt% lubricant, which is commercially available CERALENE® 2T type low-density polyethylene wax and industrial grade calcium stearate used in a weight ratio of 2:1; the balance is PVC resin, which is SG-3 type resin raw material. The raw materials are added to a high-speed mixer and mixed evenly. The mixture is plasticized and mixed at 180°C using a twin-screw extruder, and then extruded and granulated to obtain flame retardant masterbatch.

[0063] Step S2: The flame-retardant masterbatch is extruded at 180°C using a single-screw extruder and coated onto the surface of the conductor. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

[0064] Comparative Example 1 is a control example of Example 4. FRX-100 type organosilicon flame retardant and OP 935 type phosphorus flame retardant are compounded in a weight ratio of 3:1 to replace the modified phosphorus silicon flame retardant in equal amounts. The rest of the implementation process is exactly the same.

[0065] Comparative Example 2 is a control example of Example 4, in which the modified phosphorus silicon flame retardant is replaced by an equal amount of FR-AHP02 type phosphorus silicon flame retardant, and the rest of the implementation process is exactly the same.

[0066] Samples were taken from the flame-retardant masterbatch prepared above and injection molded into specimens with a thickness of 2 mm. Tensile testing was performed according to ASTM D638-2022, impact testing according to ASTM D256-2024, flame retardancy rating testing according to UL94, oxygen index testing according to ASTM D2863-2023, and smoke density testing according to ASTM E662-2017. Specific test data are shown in Table 1.

[0067] Table 1

[0068]

[0069] As shown in Table 1, the flame-retardant protective layer material of the embodiment maintains moderate tensile strength, meeting the protection requirements of electronic connection lines. Its impact strength is significantly higher than that of the comparative example, indicating that the introduction of modified phosphorus silicon flame retardant can significantly improve the mechanical toughness of PVC matrix compared with existing flame retardant systems. In terms of flame retardant performance, the flame retardant rating of the embodiment reaches V-0, the oxygen index reaches about 40%, which has high flame retardant characteristics, and the smoke density is less than 100, which has low smoke characteristics.

[0070] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A high flame-retardant electronic connection wire, comprising a conductor and a flame-retardant protective layer on its surface, characterized in that, The flame-retardant protective layer consists of: 7.5-10 wt% modified phosphorus-silicon flame retardant, 14-18 wt% plasticizer, 1.7-2.2 wt% heat stabilizer, 0.12-0.16 wt% antioxidant, and 0.9-1.3 wt% lubricant, with the balance being PVC resin; The modified phosphorus-silicon flame retardant is prepared by the following method: Step A1: Mix pentaerythritol and anhydrous dioxane by heating, purge with dry nitrogen for protection, control the temperature at 70-80℃, slowly add phosphorus oxychloride and stir for 4-4.5h, then increase the pressure to 5.5-6.5 bar, continue heating to 120-130℃ and react for 1.5-2h to prepare intermediate 1, wherein the feed ratio of pentaerythritol, phosphorus oxychloride and anhydrous dioxane is 0.1mol:0.2mol:180-220mL; Step A2: Premix diethyl ketomalonate, amino-terminated polydimethylsiloxane, and anhydrous toluene, purge with dry nitrogen, heat to 80-90℃, add trimethylaluminum and stir for 2-3 hours to prepare intermediate 2. The amino content of diethyl ketomalonate and amino-terminated polydimethylsiloxane, and the feed ratio of trimethylaluminum and anhydrous toluene are 0.1mol:0.403-0.405mol:60-80mg:420-500mL. Step A3: Premix intermediate 2 and dimethylacetamide, purge with dry nitrogen, add intermediate 1, mix and heat to 40-55℃ and stir for 6-10 h, then add triethylamine and reduce pressure to 100 Pa, continue heating to 140-150℃ and continue reacting for 2-2.5 h to prepare modified phosphorus silicon flame retardant. The amino content of intermediate 1 and intermediate 2, and the feed ratio of triethylamine and dimethylacetamide are 0.1 mol: 0.2 mol: 25-30 mL: 350-400 mL.

2. The high flame-retardant electronic connection wire according to claim 1, characterized in that, The room temperature viscosity of amino-terminated polydimethylsiloxane is not higher than 20 mm. 2 / s.

3. The high flame-retardant electronic connection wire according to claim 1, characterized in that, The plasticizer is epoxidized soybean oil.

4. The high flame-retardant electronic connection wire according to claim 1, characterized in that, The lubricant is a combination of low-density polyethylene wax and calcium stearate.

5. A method for preparing a high flame-retardant electronic connecting wire according to any one of claims 1-4, characterized in that, Specifically: Step S1: Mix the raw materials of each component evenly, then plasticize and knead the mixture using a twin-screw extruder, and then extrude and granulate it to obtain flame retardant masterbatch; Step S2: The flame-retardant masterbatch is coated onto the surface of the wire using a single-screw extruder. After cooling, a flame-retardant protective layer is formed, resulting in a highly flame-retardant electronic connection wire.

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