Preparation method of mica heat insulation tape for new energy automobile power system connecting piece

Abstract

The application discloses a preparation method of a mica heat insulation band for a new energy automobile power system connecting piece. The method comprises the following steps: mixing silicone glue, nano ceramic powder, nano silicon dioxide and a silane coupling agent to obtain a first treatment liquid; mixing acrylic resin, alcohol ester twelve, nano aerogel, magnesium hydroxide and nano white carbon black to obtain a second treatment liquid; immersing mica paper in the first treatment liquid, treating the mica paper by means of glue immersion, drying, and obtaining treated mica paper; coating the treated mica paper and glass fiber cloth to obtain a mica band; treating one side of the mica band glass fiber cloth by means of film coating using the second treatment liquid to obtain a treated mica band; and coating a PI film to the side of the treated mica band far from the glass fiber cloth, thereby obtaining the mica heat insulation band. The mica heat insulation band prepared by the method has the properties of fire prevention, heat insulation and high-temperature insulation, and meets the safety management requirements of the new energy automobile power system connecting piece.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a method for preparing a mica insulating tape for connecting components of a new energy vehicle power system. Background Technology

[0002] With the continuous development of science and technology, the new energy vehicle industry, characterized by green and environmentally friendly features, is developing rapidly. New energy vehicles include various types of vehicles powered by clean energy sources such as solar energy, electricity, hydrogen, and natural gas. In the rapid development of the new energy vehicle industry, especially electric vehicles, the power battery is a crucial component. Battery connection components include connectors, which consist of connectors and an insulating layer. The insulating layer covers the surface of the connectors. As a power source for new energy sources, the energy density of power batteries is increasing, placing higher demands on the performance of the busbars connecting the circuits between battery modules. The insulation, high-temperature resistance, and flame retardancy of the connector components are receiving increasing attention. Currently, OEMs and component manufacturers are improving the structure and researching materials for connectors, but certain safety hazards still exist. Accidents caused by thermal runaway, such as vehicle fires due to connector insulation failure, leading to short circuits and open circuits in the connectors, occur frequently, causing significant personal injury and property damage.

[0003] Currently, the high-temperature insulation material for copper busbar connectors in new energy vehicles on the market is mainly PI film. It is mainly made by hot-pressing PI film onto copper busbars, then wrapping a layer of mica tape for fire-resistant insulation, and finally impregnating it with a PVC flame-retardant sheath. Its production process is complex, and its temperature resistance range is a maximum long-term temperature of 280℃ and a short-term temperature of 400℃. As the driving range of new energy vehicles continues to increase and the energy density of batteries increases, the heat resistance of insulation materials for high-current busbars used is becoming more and more stringent. Summary of the Invention

[0004] To address the issue of poor high-temperature resistance of high-temperature insulating materials for connectors, this application provides a method for preparing mica insulating tape for connectors in new energy vehicle power systems.

[0005] In a first aspect, this application provides a method for preparing a mica insulating tape for a powertrain connector in a new energy vehicle, employing the following technical solution:

[0006] A method for preparing a mica insulating tape for a powertrain connector in a new energy vehicle includes the following steps:

[0007] (1) Preparation of mica paper treatment solution: Mix organosilicone, nano ceramic powder, nano silica and silane coupling agent, stir for 30-45 min at a stirring rate of 700-1000 r / min to obtain the first treatment solution;

[0008] (2) Preparation of heat insulation layer treatment liquid: Mix acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano white carbon black, stir for 50-60 min, stirring rate is 1000-1200 r / min, to obtain the second treatment liquid;

[0009] (3) Immerse the mica paper in the first treatment solution obtained in step (1), treat the mica paper by dipping and gluing, and then dry it to obtain the treated mica paper.

[0010] (4) The mica paper processed in step (3) is coated with fiberglass cloth to obtain mica tape;

[0011] (5) The mica tape obtained in step (4) is treated on one side of the glass fiber cloth of the mica tape by means of the second treatment liquid obtained in step (2) through coating, so as to obtain the treated mica tape;

[0012] (6) Lay the PI film onto the side of the mica tape treated in step (5) away from the fiberglass cloth, dry it, and cut it to obtain the final product.

[0013] By adopting the above technical solution, the high-temperature resistance and insulation of mica paper are improved through treatment, and the supporting strength of the material after high temperature is enhanced. A heat insulation layer is formed on the fiberglass cloth surface, solving the problem that the PI insulating film cannot withstand high temperature. When the power battery is at high temperature, the outer mica heat insulation layer can effectively prevent the PI film from melting and causing insulation failure. Compared with traditional fire-resistant mica tape, it has high insulation performance and has fireproof, heat insulation and high-temperature insulation properties, which is more in line with the safety management requirements of the power system connectors of new energy vehicles.

[0014] A mica paper treatment solution was prepared by mixing silicone rubber, nano-ceramic powder, nano-silica, and a silane coupling agent. Silicone rubber possesses excellent high and low temperature resistance, electrical insulation, oxidation stability, flame retardancy, corrosion resistance, and heat resistance, making it a good material for preparing heat-resistant mica tape. Nano-ceramic powder has excellent thermal insulation properties, high temperature resistance, and is not easily detached. The addition of nano-ceramic powder improves the high temperature resistance of silicone rubber. Nano-silica has good insulation and processing properties. Nano-silica fills the pores of mica paper, and its addition improves the insulation of silicone rubber, thereby subsequently improving the insulation and heat insulation properties of the mica tape. The silane coupling agent is used as a binder to ensure uniform mixing of silicone rubber, nano-ceramic powder, and nano-silica, and further improves the bonding strength, heat resistance, and flame retardancy of the system.

[0015] A heat insulation layer treatment solution was prepared by mixing acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica. Acrylic resin is the basic raw material for preparing the heat insulation layer treatment solution, possessing good compatibility, gloss and color retention, and heat reflection and insulation effects. Dodecyl alcohol ester is a good film-forming aid, helping to promote film formation of acrylic resin. Nano-aerogel is a solid material with the lowest thermal conductivity and excellent visible light transmittance, heat insulation and cold retention, high temperature resistance, and flame retardant properties, making it an excellent transparent heat insulation material. Mixing nano-aerogel and water-based acrylic resin to prepare a transparent heat insulation treatment solution improves the performance of acrylic resin. The heat resistance, flame retardancy, and heat insulation properties of the material are enhanced. Magnesium hydroxide has heat insulation and flame retardant functions and is used as a flame retardant. The magnesium oxide residue produced by the decomposition of magnesium hydroxide is a dense oxide that can be deposited on the surface of materials to inhibit the generation of combustible gases, thus playing a role in heat insulation, isolating oxygen, and achieving the effect of smoke suppression. Nano-silica is used as a filler and has strong adhesion and tear resistance. Nano-silica particles can be fully and uniformly dispersed in acrylic resin, which greatly improves the strength, toughness, ductility, and wear resistance of acrylic resin materials, thereby improving the heat insulation and mechanical properties of mica tape.

[0016] First, mica paper is immersed in a mica paper treatment solution with limited stirring speed and time. When the stirring speed is below 700 r / min and the stirring time is below 30 min, the uniformity of the mica treatment solution is poor. Then, it is laminated with fiberglass cloth, which acts as a reinforcing material to further improve the fire resistance and mechanical strength of the mica paper. Next, a second treatment solution is applied, with limited stirring speed and time. When the stirring speed is below 1000 rpm and the stirring time is below 50 min, the uniformity of the treatment solution is poor. Finally, a PI film is laminated to obtain the treated mica heat insulation tape. The prepared mica heat insulation tape has good fireproof, heat insulation, and electrical insulation properties.

[0017] Preferably, in step (1), the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 6-8:1.5-2.5:0.5-1.5.

[0018] By adopting the above technical solution and controlling the mass ratio of silicone rubber, nano-ceramic powder, and nano-silica within a certain range, a mica paper treatment solution with superior strength, insulation performance, and thermal insulation performance is obtained. The silicone rubber, nano-ceramic powder, and nano-silica exhibit good synergistic effects, working together to improve the mechanical properties, heat resistance, and flame retardancy of the mica insulation tape. When the mass ratio of silicone rubber is below 6%, the solubility is poor, leading to poor treatment uniformity. When the mass ratio of silicone rubber is above 8%, the treatment solution is too thin, resulting in poor overall performance of the treated product. When the mass ratio of nano-ceramic powder is below 1.5%, the strength of the mica layer in the treated product is low after high temperature. When the mass ratio of nano-ceramic powder is above 2.5%, cracks appear in the mica layer of the treated product after high temperature. When the mass ratio of nano-silica is below 0.5%, the thermal insulation of the mica layer in the treated product is poor. When the mass ratio of nano-silica is above 1.5%, crystalline impurities appear on the surface of the mica layer in the treated product. Therefore, limiting the proportions of each component within the above ranges yields a treatment solution with superior overall performance.

[0019] Preferably, in step (1), the silane coupling agent accounts for 0.2-0.5% of the total weight of the mica paper treatment liquid.

[0020] By adopting the above technical solution and limiting the amount of silane coupling agent, the components are mixed evenly, resulting in a mica treatment solution with better performance. When the proportion of silane coupling agent is less than 0.2%, the treated mica layer separates, which is not conducive to the subsequent extraction of mica paper. When the proportion is higher than 0.5%, the mica paper treatment solution causes blistering of the mica paper due to the fast curing speed.

[0021] More preferably, in step (1), the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 7:2:1, and the silane coupling agent accounts for 0.2% of the total weight of the mica paper treatment liquid.

[0022] By adopting the above technical solution and further limiting the mass ratio of organosilicon, nano-ceramic powder and nano-silica and the amount of silane coupling agent, a mica treatment solution with better performance is obtained. Under the above ratio, the prepared mica treatment solution has the best comprehensive performance. After subsequent treatment of mica paper, mica paper with good mechanical properties, flame retardancy and heat resistance is obtained.

[0023] Preferably, in step (2), the mass ratio of acrylic resin, 12-ol ester, nano aerogel, magnesium hydroxide and nano silica is 7-9:0.1-0.3:2.5-3.5:1.6-2.4:3-5.

[0024] By adopting the above technical solution and controlling the mass ratio of acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica within a certain range, a heat insulation layer treatment solution with superior mechanical properties, flame retardancy, and heat insulation performance is obtained. Acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica exhibit good synergistic effects, jointly improving the mechanical properties, heat resistance, and flame retardancy of the mica insulation tape. When the mass ratio of acrylic resin is below 7%, the solubility is poor, leading to poor treatment uniformity. When the mass ratio of acrylic resin is above 9%, the treatment solution is too thin, resulting in poor treatment performance. When the mass ratio of dodecyl alcohol ester is below 0.1%, the film formation after coating is incomplete. When the mass ratio of 12-ol ester is higher than 0.3, cracks appear after film formation via coating; when the mass ratio of nano-aerogel is lower than 2.5, the final product has poor thermal insulation; when the mass ratio of nano-aerogel is higher than 3.5, insoluble flocculent matter appears after stirring; when the mass ratio of magnesium hydroxide is higher than 1.6, the product has poor flame retardant properties; when the mass ratio of magnesium hydroxide is higher than 2.4, white undissolved particles appear after stirring; when the mass ratio of nano-silica is lower than 3, the film formation is uneven after coating; when the mass ratio of nano-silica is higher than 5, particles appear on the surface of the film after coating. Therefore, limiting the proportions of each component within the above ranges yields a thermal insulation layer treatment liquid with superior overall performance.

[0025] More preferably, in step (2), the mass ratio of acrylic resin, 12-ol ester, nano aerogel, magnesium hydroxide and nano silica is 8:0.2:3:2:4.

[0026] By adopting the above technical solution and further limiting the mass ratio of acrylic resin, alcohol ester twelve, nano aerogel, magnesium hydroxide and nano silica, a heat insulation layer treatment liquid with better performance is obtained. Under the above ratio, the heat insulation layer treatment liquid has the best comprehensive performance. After subsequent treatment of mica paper, mica paper with good mechanical properties, flame retardancy and heat resistance is obtained.

[0027] Preferably, in step (3), the drying conditions are in four stages: the first stage is 60±5℃ for 3-5 min, the second stage is 100±5℃ for 2-4 min, the third stage is 150±5℃ for 3-5 min, and the fourth stage is 80±5℃ for 3-5 min.

[0028] By adopting the above technical solution and performing drying in stages, the resulting mica paper exhibits better overall performance. The gradually increasing temperature in stages one through four facilitates the drying of the mica paper and prevents powdering or cracking. If the temperature in any stage is lower than the specified limit, the mica paper will not dry properly, and the treatment solution will not solidify, leading to subsequent mica stickiness and powdering. If the temperature in any stage is higher than the specified limit, cracking will occur on the mica surface. After treatment, nano-ceramic powder increases the hardness of the mica paper, nano-silica improves its insulation at high temperatures, and silane coupling agents ensure a tighter bond between the mica paper and the treatment solution materials.

[0029] Preferably, in step (4), the coating process is as follows: applying adhesive to fiberglass cloth, bonding mica paper, drying, and winding, with the use of silicone adhesive for coating.

[0030] By adopting the above technical solutions, the coating process helps to obtain mica insulation heat pipes with fast coating speed, high precision, and uniform thickness, thereby improving the overall performance of mica insulation heat pipes.

[0031] Preferably, in step (5), the diameter of the coating port is 0.03-0.07 mm, the temperature of the coating chamber is 60℃±10℃, and the coating speed is 1.8-2.2 m / min.

[0032] By adopting the above technical solution, when the temperature of the coating chamber is too high, the heat insulation layer treatment liquid is prone to solidify and block the gap of the coating port, causing blockage. When the temperature of the coating chamber is too low, the heat insulation layer treatment liquid has poor fluidity and is prone to blockage at the coating port. When the coating speed is too fast, the uniformity of the coating is poor. When the coating speed is too slow, the coating is prone to wrinkles. At high temperatures, the wrinkles will crack and fall off.

[0033] Preferably, in step (5), the diameter of the coating port is 0.05 mm and the coating speed is 2 m / min.

[0034] By adopting the above technical solution, the diameter of the coating nozzle and the coating speed are further limited, resulting in a coating with better uniformity and no cracking.

[0035] Secondly, this application provides a mica insulating heat pipe for a power system connector of a new energy vehicle, which is prepared by the above-mentioned method.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. In this application, the high-temperature resistance and insulation of mica paper are improved by treating the mica paper, and the supporting strength of the material after high temperature is improved. A heat insulation layer is formed on the fiberglass cloth surface, which solves the problem that the PI insulating film cannot withstand high temperature. When the power battery is hot, the outer mica heat insulation layer can effectively prevent the PI film from melting and causing insulation failure. Compared with traditional fire-resistant mica tape, it has high insulation performance and has fireproof, heat insulation and high temperature insulation properties, which is more in line with the safety management requirements of the power system connectors of new energy vehicles.

[0038] 2. This application uses mica as the material, and increases the heat insulation of mica through treatment. It is then prepared by laminating a PI film. Specifically, the surface of the mica tape is treated with heat insulation material, and the PI film is laminated onto the paper surface of the mica tape. When wrapping the copper busbar, the film side is wrapped with the copper busbar side facing outward. The heat insulation layer faces outward. The mica effectively blocks the heat-affected insulation of the PI film, thus ensuring the insulation performance of the PI film. The PVC sheath is heat-shrinked onto the outside of the copper busbar using a heat-shrinking process to form an insulation layer. The process is simple and can ensure the safety of the connectors in the new energy power system.

[0039] 3. In this application, the organosilicon, nano-ceramic powder, and nano-silica are uniformly mixed, which further improves the bonding strength, heat resistance, and flame retardancy of the system. Acrylic resin, alcohol ester dodecyl, nano-aerogel, magnesium hydroxide, and nano-silica are mixed to prepare the heat insulation layer treatment liquid, which improves the strength, toughness, flame retardancy, and fire resistance of the acrylic resin material, thereby subsequently improving the heat insulation and mechanical properties of the mica tape. Attached Figure Description

[0040] Figure 1 This is a process flow diagram of Embodiment 1 of this application.

[0041] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of this application.

[0042] Explanation of reference numerals in the attached diagram: 1. PI film; 2. Mica paper; 3. Fiberglass cloth reinforcing layer; 4. Mica tape insulation layer. Implementation

[0043] The present application will be further described in detail below with reference to the embodiments.

[0044] The raw materials used in the examples and comparative examples are all commercially available.

[0045] Example 1: A method for preparing a mica insulating tape for a powertrain connector in a new energy vehicle, comprising the following steps:

[0046] (1) Preparation of mica paper treatment solution: Mix 0.5 kg of organosilicon, nano-ceramic powder, nano-silica and silane coupling agent, stir for 38 min at a stirring rate of 900 r / min to obtain the first treatment solution; wherein, the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 7:2:1; and the silane coupling agent accounts for 0.2% of the total weight of the mica paper treatment solution.

[0047] (2) Preparation of heat insulation layer treatment liquid: 0.3 kg of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica are mixed and stirred for 55 min at a stirring rate of 1100 r / min to obtain the second treatment liquid; wherein, the mass ratio of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica is 8:0.2:3:2:4.

[0048] (3) Immerse the mica paper in the first treatment solution obtained in step (1), treat the mica paper by dipping and gluing, and then dry it to obtain the treated mica paper. The drying conditions are four stages: the first stage is 60°C for 4 minutes, the second stage is 100°C for 3 minutes, the third stage is 150°C for 4 minutes, and the fourth stage is 80°C for 4 minutes.

[0049] (4) The mica paper processed in step (3) is coated and then laminated with fiberglass cloth to obtain mica tape. The coating process is: applying adhesive to fiberglass cloth, bonding mica paper, drying, and winding. Silicone adhesive is used for coating.

[0050] (5) The mica tape obtained in step (4) is treated on one side of the glass fiber cloth of the mica tape by means of the second treatment liquid obtained in step (2) through coating, and the treated mica tape is obtained; the diameter of the coating port is 0.05 mm, the temperature of the coating chamber is 60℃, and the coating speed is 2 m / min.

[0051] (6) The PI film is bonded to the side of the mica tape treated in step (5) away from the fiberglass cloth using an organosilicon adhesive, dried, and cut to obtain the mica insulating tape for the power system connectors of new energy vehicles; the process flow diagram is as follows. Figure 1 As shown in the diagram, the structural schematic is as follows: Figure 2 As shown.

[0052] Example 2: A method for preparing a mica insulating tape for a powertrain connector in a new energy vehicle, comprising the following steps:

[0053] (1) Preparation of mica paper treatment solution: Mix 1 kg of organosilicon, nano-ceramic powder, nano-silica and silane coupling agent, stir for 30 min at a stirring rate of 700 r / min to obtain the first treatment solution; wherein, the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 6:1.5:0.5; and the silane coupling agent accounts for 0.3% of the total weight of the mica paper treatment solution.

[0054] (2) Preparation of heat insulation layer treatment liquid: 0.6 kg of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica are mixed and stirred for 60 min at a stirring rate of 1000 r / min to obtain the second treatment liquid; wherein, the mass ratio of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica is 7:0.1:2.5:1.6:5.

[0055] (3) Immerse the mica paper in the first treatment solution obtained in step (1), treat the mica paper by dipping and gluing, and then dry it to obtain the treated mica paper. The drying conditions are four stages: the first stage is 55℃ for 5 minutes, the second stage is 105℃ for 2 minutes, the third stage is 145℃ for 5 minutes, and the fourth stage is 75℃ for 5 minutes.

[0056] (4) The mica paper processed in step (3) is coated and then laminated with fiberglass cloth to obtain mica tape. The coating process is: applying adhesive to fiberglass cloth, bonding mica paper, drying, and winding. Silicone adhesive is used for coating.

[0057] (5) The mica tape obtained in step (4) is treated on one side of the glass fiber cloth of the mica tape by means of the second treatment liquid obtained in step (2) through coating, and the treated mica tape is obtained; the diameter of the coating port is 0.03 mm, the temperature of the coating chamber is 50℃, and the coating speed is 2.2 m / min.

[0058] (6) The PI film is bonded to the side of the mica tape treated in step (5) away from the fiberglass cloth using an organosilicon adhesive, dried, and cut to obtain the mica insulation tape for the power system connector of new energy vehicles.

[0059] Example 3: A method for preparing a mica insulating tape for a powertrain connector in a new energy vehicle, comprising the following steps:

[0060] (1) Preparation of mica paper treatment solution: Mix 1.2 kg of organosilicon, nano-ceramic powder, nano-silica and silane coupling agent, stir for 45 min at a stirring rate of 1000 r / min to obtain the first treatment solution; wherein, the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 8:2.5:1.5; and the silane coupling agent accounts for 0.5% of the total weight of the mica paper treatment solution.

[0061] (2) Preparation of heat insulation layer treatment liquid: 0.8 kg of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica are mixed and stirred for 50 min at a stirring rate of 1200 r / min to obtain the second treatment liquid; wherein, the mass ratio of acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano silica is 9:0.3:3.5:2.4:3.

[0062] (3) Immerse the mica paper in the first treatment solution obtained in step (1), treat the mica paper by dipping and gluing, and then dry it to obtain the treated mica paper. The drying conditions are four stages: the first stage is 65°C for 3 minutes, the second stage is 95°C for 4 minutes, the third stage is 155°C for 3 minutes, and the fourth stage is 85°C for 3 minutes.

[0063] (4) The mica paper processed in step (3) is coated and then laminated with fiberglass cloth to obtain mica tape. The coating process is: applying adhesive to fiberglass cloth, bonding mica paper, drying, and winding. Silicone adhesive is used for coating.

[0064] (5) The mica tape obtained in step (4) is treated on one side of the glass fiber cloth of the mica tape by means of the second treatment liquid obtained in step (2) through coating, and the treated mica tape is obtained; the diameter of the coating port is 0.07 mm, the temperature of the coating chamber is 70℃, and the coating speed is 1.8 m / min.

[0065] (6) The PI film is bonded to the side of the mica tape treated in step (5) away from the fiberglass cloth using an organosilicon adhesive, dried, and cut to obtain the mica insulation tape for the power system connector of new energy vehicles.

[0066] Example 4: A method for preparing a mica insulating tape for connecting parts of a new energy vehicle power system. The difference from Example 1 is that in step (1), the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 4:1.2:0.3.

[0067] Example 5: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that in step (1), the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 9:2.8:1.9.

[0068] Example 6 A method for preparing a mica insulating tape for connecting parts of a new energy vehicle power system, the difference from Example 1 is that in step (1), the silane coupling agent accounts for 0.05% of the total weight of the mica paper treatment liquid.

[0069] Example 7 A method for preparing a mica insulating tape for connecting parts of a new energy vehicle power system, the difference from Example 1 is that in step (1), the silane coupling agent accounts for 0.8% of the total weight of the mica paper treatment liquid.

[0070] Example 8 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that in step (2), the mass ratio of acrylic resin, 12-ol ester, nano aerogel, magnesium hydroxide and nano silica is 5:0.05:2.2:1.4:6.

[0071] Example 9 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle, which differs from Example 1 in that, in step (2), the mass ratio of acrylic resin, 12-ol ester, nano aerogel, magnesium hydroxide and nano silica is 11:0.5:3.7:2.6:1.

[0072] Example 10 A method for preparing a mica insulating tape for connecting parts of a new energy vehicle power system. The difference from Example 1 is that in step (3), the drying conditions are in four stages: the first stage is 50°C for 6 minutes, the second stage is 85°C for 5 minutes, the third stage is 135°C for 7 minutes, and the fourth stage is 65°C for 6 minutes.

[0073] Example 11: A method for preparing a mica insulating tape for connecting parts of a new energy vehicle power system. The difference from Example 1 is that in step (3), the drying conditions are in four stages: the first stage is 75°C for 2 minutes, the second stage is 115°C for 3 minutes, the third stage is 165°C for 2 minutes, and the fourth stage is 95°C for 3 minutes.

[0074] Example 12 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle, the difference from Example 1 is that in step (5), the temperature of the coating cavity is 40°C.

[0075] Example 13 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle, the difference from Example 1 is that in step (5), the temperature of the coating cavity is 80°C.

[0076] Example 14 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle, the difference from Example 1 is that in step (5), the coating speed is 1.6 m / min.

[0077] Example 15 A method for preparing a mica insulating tape for a power system connector of a new energy vehicle, the difference from Example 1 is that in step (5), the coating speed is 2.5 m / min.

[0078] Comparative Example 1: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that in step (1), no nano-ceramic powder is added.

[0079] Comparative Example 2: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that nano-silica is not added in step (1).

[0080] Comparative Example 3: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that in step (2), no nano-aerogel is added.

[0081] Comparative Example 4: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that magnesium hydroxide is not added in step (2).

[0082] Comparative Example 5: A method for preparing a mica insulating tape for a power system connector of a new energy vehicle. The difference from Example 1 is that in step (2), no nano-silica is added.

[0083] In the performance testing experiment, the new energy vehicle power system connectors prepared in Examples 1-15 and Comparative Examples 1-5 were coated with copper busbars using mica insulating tape. After wrapping the copper busbars with a single layer of this product, a 2mm thick PVC sheath was heat-shrinked. The resulting samples were then subjected to performance testing.

[0084] Comparative Example 6 was set up, in which copper busbars were hot-pressed with PI film, wrapped with ordinary mica tape, and then dipped in a 2mm thick PVC sheath for performance testing.

[0085] The test method for the 1000℃ heat insulation performance is as follows: an adjustable temperature blowtorch is used, and the flame temperature is adjusted to 1000℃. Then, one side of the mica heat insulation tape prepared in Examples 1-15 and Comparative Examples 1-6 is burned for 10 minutes. The temperature of the other side is detected by a contact temperature sensor.

[0086] Electrical strength test: The test was conducted according to Clause 22, "Electrical Strength," of GB / T 5019.2-2009, Test Methods for Mica Products. The sample thickness was 0.40±0.01mm. A Φ25mm / Φ75mm cylindrical electrode system was used, with a rapid voltage increase method (voltage increase rate of 1.0kV / s). The test was conducted in 25# transformer oil at 23℃±2℃. The mica insulating tapes prepared in Examples 1-15 and Comparative Examples 1-6 were subjected to electrical strength tests for normal withstand voltage, withstand voltage after high temperature of 1000℃, and withstand voltage at 500℃. The test results are shown in Table 1.

[0087] Table 1 Tests of Examples and Comparative Examples

[0088] Thermal insulation performance at 1000℃ / ℃ Normal withstand voltage / mV / mm Withstand voltage after high temperature / V 500℃ withstand voltage / mV / mm Example 1 400 AC: 60 DC: 5000 AC: 60 Example 2 402 AC: 58 DC: 5000 AC: 57 Example 3 404 AC: 59 DC: 5000 AC: 58 Example 4 430 AC: 50 DC: 4800 AC: 51 Example 5 435 AC: 51 DC: 4800 AC: 50 Example 6 415 AC: 54 DC: 4950 AC: 55 Example 7 418 AC: 53 DC: 4950 AC: 54 Example 8 450 AC: 50 DC: 4750 AC: 49 Example 9 452 AC: 49 DC: 4780 AC: 50 Example 10 425 AC: 52 DC: 4900 AC: 53 Example 11 428 AC: 53 DC: 4910 AC: 52 Example 12 413 AC: 53 DC: 4950 AC: 53 Example 13 412 AC: 52 DC: 4960 AC: 53 Example 14 410 AC: 53 DC: 4960 AC: 54 Example 15 408 AC: 54 DC: 4970 AC: 53 Comparative Example 1 480 AC: 45 DC: 4600 AC: 46 Comparative Example 2 470 AC: 47 DC: 4620 AC: 45 Comparative Example 3 490 AC: 42 DC: 4500 AC: 43 Comparative Example 4 465 AC: 45 DC: 4550 AC: 44 Comparative Example 5 455 AC: 48 DC: 4650 AC: 46 Comparative Example 6 700 AC: 40 DC: 3500 AC: 20

[0089] The mica insulating tapes prepared in Examples 1-3 of this application have good heat insulation, fire resistance, and high-temperature insulation properties. Among them, the mica insulating tape prepared in Example 1 has the best performance when applied to copper busbars, with a heat insulation performance of 400℃ at 1000℃, a normal AC withstand voltage of 60mV / mm, a DC withstand voltage of 5000V after high temperature, and a AC withstand voltage of 60mV / mm at 500℃. In contrast, ordinary mica tape was used in Comparative Example 6, which had a heat insulation performance of up to 700℃ at 1000℃, a normal AC withstand voltage of 40mV / mm, a DC withstand voltage of 3500V after high temperature, and a AC withstand voltage of 20mV / mm at 500℃. The comparison shows that compared with ordinary fire-resistant mica tape, which has high insulation performance, the mica insulating tape prepared in this application has fire resistance, heat insulation, and high-temperature insulation properties, which better meets the safety management requirements of new energy vehicle power system connectors.

[0090] Examples 4-5 show that the mass ratio of silicone rubber, nano-ceramic powder, and nano-silica was changed. As shown in Table 1, compared with Examples 1-3, the thermal insulation performance of the mica insulating tape at 1000℃ increased, while the voltage resistance at normal conditions, voltage resistance after high temperature, and voltage resistance at 500℃ all decreased. This indicates that there is a synergistic effect between silicone rubber, nano-ceramic powder, and nano-silica, and that the ratio of silicone rubber, nano-ceramic powder, and nano-silica within a certain range has good comprehensive performance.

[0091] Examples 6-7 varied the mass ratio of silane coupling agent to mica paper treatment solution. As shown in Table 1, compared with Examples 1-3, the thermal insulation performance of the mica insulating tape at 1000℃ increased, while the voltage resistance at normal conditions, high temperature, and 500℃ all decreased. This indicates that the amount of silane coupling agent added affects the performance of the mica treatment solution. When the proportion of silane coupling agent exceeds a certain range, the mica layer of the treated product separates, which is not conducive to the subsequent extraction of mica paper.

[0092] Examples 8-9 varied the mass ratio of acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica. As shown in Table 1, compared with Examples 1-3, the thermal insulation performance of the mica insulating tape at 1000℃ increased, while the voltage resistance at normal conditions, high temperature, and 500℃ all decreased significantly. This indicates that there is a synergistic effect between acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica. The ratio of acrylic resin, dodecyl alcohol ester, nano-aerogel, magnesium hydroxide, and nano-silica within a certain range has good comprehensive performance. The prepared thermal insulation layer treatment liquid has the best comprehensive performance. Subsequent treatment of the mica paper yields mica paper with good mechanical properties, flame retardancy, and heat resistance.

[0093] Examples 10-11 changed the drying conditions of mica paper. As shown in Table 1, compared with Examples 1-3, the heat insulation performance of the mica insulating tape at 1000℃ increased, while the voltage resistance at normal conditions, voltage resistance after high temperature, and voltage resistance at 500℃ all decreased. This indicates that by drying in stages, the resulting mica paper has better overall performance. The temperature gradually increases from the first to the fourth stage, which helps the mica paper dry and avoids powdering or cracking.

[0094] Examples 12-13 changed the coating chamber temperature, and Examples 14-15 changed the coating speed. As can be seen from Table 1, compared with Examples 1-3, the thermal insulation performance of the mica insulating tape at 1000℃ increased, while the voltage resistance at normal conditions, voltage resistance after high temperature, and voltage resistance at 500℃ all decreased, indicating that both the coating chamber temperature and the coating speed affect the performance of the mica tape.

[0095] In Comparative Example 1, without the addition of nano-ceramic powder, Table 1 shows that the thermal insulation performance at 1000℃ is 480℃, the normal withstand voltage AC is 45mV / mm, the withstand voltage DC after high temperature is 4600V, and the withstand voltage AC at 500℃ is 46mV / mm. Compared with Example 1, the thermal insulation performance of the mica insulating tape at 1000℃ is significantly increased, while the withstand voltage at normal temperature, after high temperature, and at 500℃ are all significantly decreased, indicating that nano-ceramic powder can improve the high-temperature resistance of silicone.

[0096] In Comparative Example 2, without the addition of nano-silica, Table 1 shows that the thermal insulation performance at 1000℃ is 470℃, the normal withstand voltage AC is 47mV / mm, the withstand voltage DC after high temperature is 4620V, and the withstand voltage AC at 500℃ is 45mV / mm. Compared with Example 1, the thermal insulation performance of the mica insulating tape at 1000℃ is greater, while the withstand voltage at normal temperature, after high temperature, and at 500℃ are all significantly reduced. This indicates that nano-silica can improve the mechanical properties and high-temperature resistance of silicone rubber.

[0097] In Comparative Example 3, without the addition of nano-aerogel, Table 1 shows that the thermal insulation performance at 1000℃ is 490℃, the normal withstand voltage AC is 42mV / mm, the withstand voltage DC after high temperature is 4500V, and the withstand voltage AC at 500℃ is 43mV / mm. Compared with Example 1, the thermal insulation performance of the mica insulation tape at 1000℃ is greater, while the withstand voltage at normal temperature, after high temperature, and at 500℃ are all significantly reduced. This indicates that nano-aerogel can improve the thermal insulation, cold preservation, high temperature resistance, and flame retardant properties of the mica insulation tape.

[0098] Comparative Example 4 did not add magnesium hydroxide, and Comparative Example 5 did not add nano-silica. As shown in Table 1, compared with Example 1, the thermal insulation performance of the mica insulation tape at 1000℃ was significantly increased, while the voltage resistance at normal conditions, voltage resistance after high temperature, and voltage resistance at 500℃ were significantly decreased. This indicates that magnesium hydroxide has thermal insulation and flame retardant functions. The addition of magnesium hydroxide can improve the flame retardant performance of the mica insulation tape. The nano-silica particles can be fully and uniformly dispersed in the acrylic resin, which greatly improves the strength, toughness, ductility, and wear resistance of the acrylic resin material, thereby improving the thermal insulation and mechanical properties of the mica tape.

[0099] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a mica insulating tape for connecting components of a new energy vehicle power system, characterized in that, Includes the following steps: (1) Preparation of mica paper treatment solution: Mix organosilicone, nano ceramic powder, nano silica and silane coupling agent, stir for 30-45 min at a stirring rate of 700-1000 r / min to obtain the first treatment solution; (2) Preparation of heat insulation layer treatment liquid: Mix acrylic resin, alcohol ester dodecyl, nano aerogel, magnesium hydroxide and nano white carbon black, stir for 50-60 min, stirring rate is 1000-1200 r / min, to obtain the second treatment liquid; (3) Immerse the mica paper in the first treatment solution obtained in step (1), treat the mica paper by dipping and gluing, and then dry it to obtain the treated mica paper. (4) The mica paper processed in step (3) is coated with fiberglass cloth to obtain mica tape; (5) The mica tape obtained in step (4) is treated on one side of the glass fiber cloth of the mica tape by means of the second treatment liquid obtained in step (2) through coating, so as to obtain the treated mica tape; (6) Lay the PI film onto the side of the mica tape treated in step (5) away from the fiberglass cloth, dry it, and cut it to obtain the product; In step (1), the mass ratio of organosilicon, nano-ceramic powder and nano-silica is 6-8:1.5-2.5:0.5-1.5; In step (2), the mass ratio of acrylic resin, 12-ol ester, nano aerogel, magnesium hydroxide and nano silica is 7-9:0.1-0.3:2.5-3.5:1.6-2.4:3-5.

2. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (1), the silane coupling agent accounts for 0.2-0.5% of the total weight of the mica paper treatment liquid.

3. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (1), the mass ratio of silicone, nano-ceramic powder and nano-silica is 7:2:

1.

4. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (2), the mass ratio of acrylic resin, alcohol ester twelve, nano aerogel, magnesium hydroxide and nano silica is 8:0.2:3:2:

4.

5. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (3), the drying conditions are in four stages: the first stage is 60±5℃ for 3-5 min, the second stage is 100±5℃ for 2-4 min, the third stage is 150±5℃ for 3-5 min, and the fourth stage is 80±5℃ for 3-5 min.

6. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (4), the coating process is as follows: applying adhesive to the fiberglass cloth, bonding with mica paper, drying, and winding. The coating is carried out using an organosilicon adhesive.

7. The method for preparing a mica insulating tape for a new energy vehicle power system connector according to claim 1, characterized in that, In step (5), the diameter of the coating port is 0.03-0.07 mm, the temperature of the coating chamber is 60℃±10℃, and the coating speed is 1.8-2.2 m / min.

8. A mica insulating heat pipe for a power system connector of a new energy vehicle, which is prepared by the method described in any one of claims 1-7.

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