Search

CN-121460260-B - Impact-resistant insulating busbar and preparation method thereof

CN121460260BCN 121460260 BCN121460260 BCN 121460260BCN-121460260-B

Abstract

The invention discloses an impact-resistant insulating busbar and a preparation method thereof, and relates to the technical field of power electronic device manufacturing. The busbar comprises a base material, an adhesive layer and an insulating layer. The insulating layer is prepared from furan functionalized polyolefin elastomer, bismaleimide cross-linking agent, catechol-borate modified EVA, liquid crystal elastomer/lead zirconate titanate core-shell material, hexagonal boron nitride nano-sheet, 3, 4-ethylenedioxythiophene, polyethylene glycol-polystyrene-poly perfluorohexyl ethyl acrylate block copolymer and other functional additives through a specific process. The anti-impact insulating busbar prepared by the invention has the advantages of high impact resistance, excellent heat resistance, long-acting environmental stability and interface reliability while maintaining excellent electrical insulation performance, and is suitable for power equipment under severe working conditions.

Inventors

  • LI JIANBO
  • CHEN ZHIQIANG
  • HU GUIYUN

Assignees

  • 厦门市克成精密金属工业有限公司

Dates

Publication Date
20260505
Application Date
20251229

Claims (9)

  1. 1. An impact-resistant insulating busbar is characterized by comprising a base material, an adhesive layer and an insulating layer; The base material is a copper bar or an aluminum alloy bar; the adhesive layer is obtained by immersing a substrate in a solvent containing bifunctional group molecules; the difunctional group molecule is 2-methyl-3-mercapto furan or tri (2-furyl) phosphine; The insulating layer comprises the following raw materials in parts by weight: 60-80 parts of furan functionalized polyolefin elastomer; 8-12 parts of bismaleimide cross-linking agent; 20-40 parts of catechol-borate modified EVA; 15-30 parts of liquid crystal elastomer/lead zirconate titanate core-shell material; 18-27 parts of hexagonal boron nitride nanosheets; 2-3 parts of 3, 4-ethylenedioxythiophene; 2-8 parts of polyethylene glycol-polystyrene-poly perfluorohexyl ethyl acrylate block copolymer; 0.5-1 part of antioxidant; 5-15 parts of silane surface modified aluminum hydroxide micropowder; 0.5-3 parts of voltage stabilizer; the preparation method of the furan functionalized polyolefin elastomer comprises the following steps: adding maleic anhydride grafted polyolefin elastomer into a vacuum internal mixer, heating to 140-150 ℃ under the protection of nitrogen, stirring, melting and plasticizing for 3min at the rotating speed of 30-60r/min, adding 2-furanmethanamine, carrying out blending reaction for 15-30min, adding amino-terminated polyether and p-toluenesulfonic acid, heating to 160-180 ℃, vacuumizing for 1-2min, stirring and reacting for 20-40min at the rotating speed of 60-80r/min, quickly taking out the mixed material, tabletting and cooling, and carrying out vacuum drying for 24-48h at the temperature of 80 ℃ to obtain furan functionalized polyolefin elastomer; The preparation method of the catechol-borate modified EVA comprises the following steps: A1, dissolving maleic anhydride grafted ethylene-vinyl acetate copolymer in N, N-dimethylformamide containing a trace amount of deionized water, stirring at a low speed for 2-4 hours at 50-60 ℃, adding N-hydroxysuccinimide and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, and stirring for 0.5-1 hour under the condition of nitrogen atmosphere and room temperature to obtain a reaction system solution; A2, preparing an N, N-dimethylformamide mixed solution containing dopamine hydrochloride and triethylamine, dripping the N, N-dimethylformamide mixed solution into the reaction system solution obtained in the step A under the conditions of nitrogen atmosphere, room temperature and light shielding, stirring and reacting for 12-24 hours to obtain a reaction solution, dripping the reaction solution into a mixed solvent consisting of diethyl ether and N-hexane in high-speed stirring for precipitation, filtering, washing and drying to obtain catechol modified EVA; a3, dissolving the catechol modified EVA obtained in the step A2 in tetrahydrofuran, adding 1, 4-phenyldiboronic acid and a trace amount of methanol, reacting for 6-12 hours at room temperature under stirring, pouring the product into petroleum ether with 10 times of the volume of the product, stirring, inducing precipitation and filtering, collecting precipitate, washing the precipitate with petroleum ether for 3 times, and vacuum drying at 40 ℃ for 24 hours to obtain catechol-borate modified EVA; the preparation method of the liquid crystal elastomer/lead zirconate titanate core-shell material comprises the following steps: B1, dispersing nano lead zirconate titanate particles in an ethanol solution with the mass fraction of 1-3% of 3- (methacryloyloxy) propyl trimethoxysilane, regulating the pH value to 4-5, refluxing and stirring at 70 ℃ for 12-24 hours, centrifuging, and washing to obtain KH-570 modified PZT particles; And B2, dispersing KH-570 modified PZT particles obtained in the step B1 in N, N-dimethylformamide, adding a diacrylate monomer containing a liquid crystal unit, a pentaerythritol tetra (3-mercaptopropionic acid) ester chain transfer agent and an azodiisobutyronitrile free radical initiator, stirring and reacting for 6-10 hours in a nitrogen atmosphere at 75-85 ℃, centrifuging, alternately washing the N, N-dimethylformamide and acetone for 3 times, vacuum drying at 80 ℃ for 12-24 hours, and irradiating for 1-2 hours under ultraviolet light to obtain the liquid crystal elastomer/lead zirconate titanate core-shell material.
  2. 2. The impact-resistant insulation busbar of claim 1, wherein the amine-terminated polyether has a functionality of 2 and a number average molecular weight of 1800-2200; The mass ratio of the maleic anhydride grafted polyolefin elastomer to the 2-furanmethylamine to the amino-terminated polyether to the p-toluenesulfonic acid is 100 (0.05-0.5) (4.1-10.2) (0.1-0.55).
  3. 3. The impact-resistant insulation busbar of claim 1, wherein the bismaleimide cross-linking agent is 1,1' - (methylenedi-4, 1-phenylene) bismaleimide.
  4. 4. The impact-resistant insulation busbar of claim 1, wherein in the step A1, the maleic anhydride grafted ethylene-vinyl acetate copolymer, deionized water, N-dimethylformamide, N-hydroxysuccinimide and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride are used in a ratio of 10g to 0.36g to 200mL to 0.6g to 1.15g; in the step A2, the dosage ratio of the dopamine hydrochloride, the triethylamine to the N, N-dimethylformamide in the mixed solution containing the dopamine hydrochloride and the triethylamine is 0.5g to 0.35g to 10mL, the volume ratio of the mixed solution of the N, N-dimethylformamide to the reaction system solution in the step A2 is 1 to 20, the volume ratio of the diethyl ether to the N-hexane in the mixed solvent in the step A2 is (1-2) to (1-2), the volume ratio of the reaction solution to the mixed solvent in the step A2 is (1-12), and the dosage ratio of the catechol modified EVA, the tetrahydrofuran, the 1, 4-phenyldiboronic acid and the methanol in the step A3 is 5g to 50mL to 0.18g to 1.5g.
  5. 5. The shock-resistant insulating busbar according to claim 1, wherein in the step B1, the particle size of the nano lead zirconate titanate particles is 100-200nm, the volume ratio of ethanol to deionized water in the ethanol solution is 19:1, and the dosage ratio of the nano lead zirconate titanate particles to the ethanol solution is 1g (40-60) mL.
  6. 6. The shock resistant insulation busbar according to claim 1, wherein in the step B2, the diacrylate monomer containing the liquid crystal unit is any one of 1, 4-bis- [4- (3-acryloxypropoxy) benzoyloxy ] -2-methylbenzene and 1, 4-bis- [4- (6-acryloxyhexyloxy) benzoyloxy ] -2-methylbenzene, and the KH-570 modified PZT particles, N-dimethylformamide, pentaerythritol tetrakis (3-mercaptopropionate) transfer agent, azobisisobutyronitrile free radical initiator and the diacrylate monomer containing the liquid crystal unit are used in a ratio of 1g:20mL:0.2g:0.02g:2g.
  7. 7. The anti-impact insulation busbar of claim 1, wherein the antioxidant is any one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant BHT, antioxidant DLTP and antioxidant TNPP.
  8. 8. The impact-resistant insulating busbar of claim 1, wherein the voltage stabilizer is any one of pyromellitic diimide and N, N' -dimethyl-3, 4,9, 10-perylene tetracarboxylic diimide ‌.
  9. 9. The method for preparing the impact-resistant insulating busbar according to any one of claims 1 to 8, which is characterized by comprising the following specific steps: S1, sequentially degreasing, sand blasting coarsening, cleaning and drying a substrate, immersing the substrate in a solvent containing bifunctional group molecules at 50-60 ℃ for 0.5-1h, taking out the substrate, washing the substrate with a corresponding solvent, and drying the substrate in vacuum at 40 ℃ to obtain a busbar with an adhesive layer; The mass fraction of the difunctional group molecules in the solvent is 1-3%; the solvent is any one or two of ethanol, propanol, isopropanol, butanone, acetone, toluene and ethyl acetate; S2, weighing insulating layer raw materials according to parts by weight, blending furan functionalized polyolefin elastomer, catechol-borate modified EVA, liquid crystal elastomer/lead zirconate titanate core-shell material, hexagonal boron nitride nano-sheet, polyethylene glycol-polystyrene-poly perfluorohexyl ethyl acrylate segmented copolymer, antioxidant, silane surface modified aluminum hydroxide micro powder and voltage stabilizer in an internal mixer at the temperature of 120-140 ℃ for 2-3min at the rotating speed of 30r/min, adding 3, 4-ethylenedioxythiophene, increasing the rotating speed to 60-80r/min, blending for 10-15min, cooling to 90-95 ℃, adding bismaleimide cross-linking agent, discharging sheets after uniform mixing, cooling and granulating to obtain insulating layer composite master batch; S3, discharging the masterbatch with the adhesive layer prepared in the step S1 into a preheating mould, filling the insulating layer composite masterbatch prepared in the step S2, hot-pressing for 15-25min at the temperature of 170-180 ℃ and the pressure of 15-20MPa, and demoulding after pressure maintaining and cooling to obtain the impact-resistant insulating masterbatch.

Description

Impact-resistant insulating busbar and preparation method thereof Technical Field The invention relates to the technical field of power electronic device manufacturing, in particular to an impact-resistant insulating busbar and a preparation method thereof. Background The insulating busbar is used as a key connecting part in a power transmission and distribution system, and has the core function of providing long-term and reliable insulating protection while ensuring electrical communication. With the rapid development of new energy power generation, electric automobiles and high-end equipment manufacturing industry, the operation environment of the insulating busbar is increasingly harsh, and the insulating busbar is not only required to bear continuous power frequency or direct-current high voltage, but also is often exposed to frequent mechanical vibration, impact, extreme temperature circulation, high humidity, pollution and other complex working conditions. This presents an unprecedented challenge to the overall performance of the insulating material, not only in requiring excellent initial dielectric strength, but also in maintaining performance stability and reliability under long-term coupling of dynamic mechanical, thermal and environmental stresses, i.e., achieving balance of multiple properties such as electrical, mechanical, thermal, environmental, and long-term durability. Currently, insulating materials widely used in insulating bus bars mainly include thermosetting resins (e.g., epoxy resins, silicone resins) and composites thereof, and polyolefin materials (e.g., XLPE, XLPO) crosslinked by irradiation or chemical. These traditional material systems expose the following technical bottlenecks to be solved in long-term application practice: (1) The mechanical property, the electrical insulation property and the heat resistance are difficult to cooperatively improve. Conventional modification methods often improve performance in some way by adding inorganic fillers (e.g., silica, aluminum hydroxide), but tend to result in performance imbalances. For example, the addition of a large amount of filler to increase rigidity can impair the flexibility and impact resistance of the material, and can easily crack under vibration conditions, and the addition of ceramic filler to increase thermal conductivity can introduce electrical weaknesses that affect insulation reliability. The impact resistance and flexibility of the material often have contradiction with high strength, high heat conduction and high heat resistance. (2) The reliability of the material interior and the interfaces between layers under dynamic stress is insufficient. Under the conditions of long-term thermal cycle, mechanical vibration and cold and hot impact, the defects of microcrack, interface layering and the like are easily generated due to the fact that the thermal expansion coefficients between the organic polymer matrix and the inorganic filler are not matched, and the bonding interface between the insulating layer and the metal busbar is easy to age. These defects will become the starting point of partial discharge and breakdown path, severely threatening long-term insulation safety. The prior art relies on physical bonding or simple silane coupling agent treatment, and the interface binding force is remarkably attenuated under dynamic stress. (3) The lack of an active coping mechanism for complex multifactor aging processes has limited long-term durability. The performance decay of conventional insulating materials is a passive, irreversible process in the face of multiple aging factors such as temperature fluctuations, electric field persistence, environmental medium intrusion, etc. For example, in a hot and humid environment, moisture penetration can accelerate hydrolytic aging of materials and lead to surface leakage, and under long-term electrical stress, space charge accumulation is prone to electrical dendrite. Most of the existing material systems are static structures, impact energy cannot be dissipated through physical or chemical changes of the existing material systems, stress distribution is homogenized or early damage is repaired, life prediction is difficult, and risks under extreme or unexpected working conditions are high. (4) The co-design of surface properties and bulk properties is lacking. High humidity, salt fog or pollution environment is easy to form continuous water film or conducting layer on the surface of the insulating material to trigger creeping discharge and flashover. Most of the existing solutions are surface-coated hydrophobic coatings, but such coatings have the problems of weak binding force with a substrate, easy abrasion and poor durability, and cannot form a stable integrated protection system with a bulk material. In summary, although the existing insulation busbar technology can meet the basic insulation requirement, the existing insulation busbar technology has obvious defects in the