High voltage resistant photocured insulating coating and its preparation method

Abstract

The application relates to the technical field of paint, and discloses a high-voltage-resistant light-cured insulating paint and a preparation method thereof. The paint is formed by mixing two-functionality polyurethane acrylate, isobornyl acrylate, isobornyl methacrylate and the like as UV monomers and adding modified mica functional material and the like as an additive. The modified mica functional material is prepared by modifying macromolecular substances with anthracene-perfluoro block alternating connection structure and containing unsaturated alkenyl functional groups on the surface of mica powder. The unsaturated alkenyl functional groups in the macromolecular substances can participate in the polymerization process of the UV monomers, the mica powder is uniformly distributed in the coating, a continuous and stable physical barrier layer is formed, and the voltage resistance of the coating is improved. Meanwhile, the rigid anthracene ring and a large amount of fluorine elements contained in the structure of the macromolecular substances can effectively enhance the heat resistance and high-voltage breakdown resistance of the coating.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a high-voltage resistant photocurable insulating coating and its preparation method. Background Technology

[0002] With the rapid development and technological advancements in the new energy vehicle industry, batteries, as a core component, are receiving increasing attention. The power battery packs installed in new energy vehicles are typically composed of multiple individual battery cells. However, the traditional PET blue film used in high-voltage, high-energy-density cells faces the risk of cohesion breakdown, voltage breakdown leading to short circuits within the cell, and ultimately, thermal runaway, resulting in catastrophic consequences such as the entire battery pack burning or exploding. This poses a significant safety hazard. Therefore, it is necessary to develop alternatives to PET blue film to prevent these phenomena.

[0003] The use of coatings to replace PET blue film has become increasingly common in recent years. Among them, UV-curable coatings have a rapid curing effect and are therefore widely used in power batteries. However, conventional UV-curable coatings are actually difficult to meet the requirements of high-voltage power batteries. Moreover, since power batteries continuously generate heat during use, the coating needs to have good heat resistance. Therefore, developing UV-curable coatings with excellent comprehensive performance is of great significance for their further application in the field of power batteries. Summary of the Invention

[0004] In order to solve the problems mentioned in the background art, the purpose of this invention is to provide a high voltage resistant photocurable insulating coating and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0007] 30-40 parts of bifunctional polyurethane acrylate;

[0008] 8-10 parts of isoborneol acrylate;

[0009] 8-10 parts of isobornyl methacrylate;

[0010] 1-2 parts of phosphate acrylate;

[0011] 8-10 parts lauryl acrylate;

[0012] 1-3.5 parts of modified mica functional material;

[0013] Photoinitiator 0.5-1 part;

[0014] 1-2 parts of auxiliary agent;

[0015] 3-5 parts pigment;

[0016] 5-10 parts of nano-alumina.

[0017] As a further aspect of the present invention, the preparation method of the modified mica functional material includes the following steps:

[0018] Step 1: Use a silane coupling agent to modify the surface of mica powder to obtain surface-organic mica powder;

[0019] Step 2: Add the surface-organized mica powder and N,N-dimethylformamide to a nitrogen-filled reactor. After dispersing evenly, continue to add the diacid linker and catalyst. After the addition is complete, raise the temperature to 70-80℃ and keep it at that temperature for 2-4 hours. Then, add the anthracene derivative to the reactor and stir evenly. Further raise the temperature to 80-90℃ and continue stirring and keeping it at that temperature for 9-18 hours. Then, lower the temperature to 40-50℃ and add the functional reagent to the reactor. Stir for 1-2 hours, then stop heating, cool down and discharge the material. Centrifuge to remove the solid material, and after washing and vacuum drying, obtain the modified mica functional material.

[0020] As a further embodiment of the present invention, the 3-glycidyl etheroxypropyltrimethoxysilane or 3-glycidyl etheroxypropyltriethoxysilane is used.

[0021] As a further embodiment of the present invention, the diacid linker is any one of 2-(4,4,5,5,6,6,6-heptafluorohexyl)malonic acid, perfluoroglutaric acid, or perfluoroazelic acid.

[0022] As a further embodiment of the present invention, the catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, N,N-dimethylbenzylamine, tetramethylammonium bromide, or tetrabutylammonium chloride.

[0023] As a further aspect of the present invention, the anthracene derivative is prepared by the following method:

[0024] 9,10-Di(hydroxymethyl)anthracene was added to toluene and stirred until completely dissolved. Then, epichlorohydrin and boron trifluoride diethyl ether complex were added. After the addition was complete, the temperature was raised to 60-70℃ and stirred for 2-4 hours. Then, a 10-25% sodium hydroxide aqueous solution was added and kept at this temperature for 1-2 hours under continuous stirring. The solvent was evaporated and removed, and the product was collected and purified to obtain the anthracene derivative.

[0025] As a further aspect of the present invention, the molar ratio of 9,10-bis(hydroxymethyl)anthracene and epichlorohydrin is 1:2.

[0026] As a further embodiment of the present invention, the functional reagent is methacryloyl chloride or acryloyl chloride.

[0027] In the above technical solution, mica powder is first modified with a silane coupling agent containing epoxy groups to obtain surface-organized mica powder. Then, under the action of a catalyst, the epoxy groups of the surface-organized mica powder can undergo ring-opening esterification with the carboxyl substituents in the diacid linker structure. Furthermore, by using the diacid linker for bridging, the diacid linker and anthracene derivative undergo continuous ring-opening esterification on the mica powder surface, thereby modifying the mica powder surface with a macromolecular substance connected by ester bonds and having an anthracene-perfluorinated block alternating linkage structure. Finally, by using a functional reagent to condense with the hydroxyl groups generated by the ring-opening reaction in the macromolecular substance structure, unsaturated alkenyl functional groups are introduced into the macromolecular substance structure to obtain modified mica functional material.

[0028] The anthracene derivatives are prepared from 9,10-bis(hydroxymethyl)anthracene and epichlorohydrin. The active hydroxyl groups and epoxy groups in their structures first undergo a ring-opening reaction under the action of boron trifluoride diethyl ether complex. Then, under the action of sodium hydroxide, the hydroxyl groups generated by the ring-opening reaction undergo ring closure with the halogen. By controlling the amount of both, anthracene derivatives containing two equivalent epoxy groups in their structure can be obtained.

[0029] As a further aspect of the present invention, the photoinitiator is any one of benzoin dimethyl ether, photoinitiator 907, or photoinitiator 1173; the auxiliary agent is polydimethylsiloxane; and the pigment is any one of iron oxide red, titanium dioxide, or chromium oxide green.

[0030] A method for preparing a high-voltage resistant photocurable insulating coating includes the following steps:

[0031] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0032] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 800-1000 r / min, and mechanically mix for 30-60 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-300 mesh filter to obtain a light-curing insulating coating.

[0033] The beneficial effects of this invention are:

[0034] (1) This invention prepares a macromolecular material with an anthracene-perfluorinated block alternating linkage structure and containing unsaturated alkenyl functional groups on the surface of mica powder as an additive. This additive is mixed with UV monomers. During the subsequent photocuring process, the unsaturated alkenyl functional groups in the macromolecular material can participate in the polymerization process of the UV monomers, thereby enabling the mica powder and the coating molecular chains to interconnect. This promotes the uniform distribution of mica powder in the coating, thus efficiently utilizing the layered chain structure of the mica powder to form a continuous and stable physical barrier layer, improving the voltage resistance of the coating. At the same time, the rigid anthracene rings in the macromolecular material structure can significantly enhance the stability of the coating molecular chains, thereby effectively improving the heat resistance of the coating. In addition, the large amount of fluorine in the macromolecular material structure can enhance the high voltage breakdown resistance of the coating by reducing the dielectric constant of the coating.

[0035] (2) The seamless integration of UV coating materials with the battery provides more comprehensive protection for the battery, effectively preventing the risks of short circuits and thermal runaway. This material ensures more reliable electrical isolation between cells in a battery system operating under high voltage, thereby improving the safety of the entire battery pack. Moreover, UV coating technology has environmental advantages, as it does not produce volatile organic compounds (VOCs), meeting environmental protection requirements. In addition, the smooth and flat surface of the UV coating helps improve the overall aesthetics of the battery pack and makes subsequent processing easier. Furthermore, UV curing can complete the curing process in a short time, greatly improving production efficiency.

[0036] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Preparation Example

[0039] Preparation of modified mica functional materials:

[0040] Step 1: Disperse 2.5g of mica powder ultrasonically in a 60% (v / v) ethanol aqueous solution. Then add 1.5g of 3-glycidyl etheroxypropyltriethoxysilane to the resulting dispersion. After the addition is complete, stir until homogeneous, raise the temperature to 70℃, keep it at that temperature for 6 hours, cool down and discharge the material. Collect the solid material, wash it, and vacuum dry it to obtain surface-organized mica powder.

[0041] Step 2: Add 2.4g of surface-organized mica powder and N,N-dimethylformamide to a nitrogen-filled reactor. After dispersing evenly, add 1.6g of perfluoroazelic acid and 0.2g of tetrabutylammonium bromide. After the addition is complete, raise the temperature to 75℃ and keep it at that temperature for 3 hours. Then add 1g of anthracene derivative to the reactor and stir evenly. Raise the temperature further to 85℃ and keep it at that temperature and stirring for 16 hours. Then lower the temperature to 45℃ and add 0.6g of acryloyl chloride to the reactor. Stir for 2 hours, then stop heating, cool down and discharge the material. Centrifuge to remove the solid material, wash and vacuum dry it to obtain the modified mica functional material.

[0042] Anthracene derivatives were prepared using the following methods:

[0043] 0.8 g of 9,10-bis(hydroxymethyl)anthracene was added to toluene and stirred until completely dissolved. Then, 0.6 g of epichlorohydrin and 0.1 g of boron trifluoride diethyl ether complex were added. After the addition was complete, the temperature was raised to 65 °C and stirred for 3 h. Then, 5 mL of 10% sodium hydroxide aqueous solution was added and kept at this temperature for 1.5 h under constant stirring. The solvent was evaporated to remove the solvent, the product was collected, and purified to obtain the anthracene derivative.

[0044] Example 1

[0045] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0046] 30 parts of bifunctional polyurethane acrylate;

[0047] 8 parts of isoborneol acrylate;

[0048] 8 parts of isobornyl methacrylate;

[0049] 1 part of phosphate acrylate;

[0050] 8 parts lauryl acrylate;

[0051] One part of modified mica functional material;

[0052] 0.5 parts of dimethyl benzoate;

[0053] 1 part of polydimethylsiloxane;

[0054] 3 parts of iron oxide red;

[0055] Five parts of nano-alumina.

[0056] The preparation method of the coating includes the following steps:

[0057] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0058] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 1000 r / min, and mechanically mix for 40 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-mesh filter to obtain a light-curing insulating coating.

[0059] The preparation method of the modified mica functional material is shown in the preparation example, and the same applies to the following.

[0060] Example 2

[0061] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0062] 35 parts of bifunctional polyurethane acrylate;

[0063] 8 parts of isoborneol acrylate;

[0064] 8 parts of isobornyl methacrylate;

[0065] 1.5 parts of phosphate acrylate;

[0066] 8 parts lauryl acrylate;

[0067] 3 parts of modified mica functional material;

[0068] 0.6 parts of dimethyl benzoate;

[0069] 1.5 parts of polydimethylsiloxane;

[0070] 4 parts of iron oxide red;

[0071] 8 parts of nano-alumina.

[0072] The preparation method of the coating includes the following steps:

[0073] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0074] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 1000 r / min, and mechanically mix for 40 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-mesh filter to obtain a light-curing insulating coating.

[0075] Example 3

[0076] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0077] 40 parts of bifunctional polyurethane acrylate;

[0078] 10 parts of isoborneol acrylate;

[0079] 10 parts of isobornyl methacrylate;

[0080] Two parts of phosphate acrylate;

[0081] 10 parts lauryl acrylate;

[0082] 3.5 parts of modified mica functional material;

[0083] 1 part of benzoin dimethyl ether;

[0084] 2 parts of polydimethylsiloxane;

[0085] 5 parts of iron oxide red;

[0086] 10 parts of nano-alumina.

[0087] The preparation method of the coating includes the following steps:

[0088] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0089] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 1000 r / min, and mechanically mix for 40 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-mesh filter to obtain a light-curing insulating coating.

[0090] Comparative Example 1

[0091] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0092] 35 parts of bifunctional polyurethane acrylate;

[0093] 8 parts of isoborneol acrylate;

[0094] 8 parts of isobornyl methacrylate;

[0095] 1.5 parts of phosphate acrylate;

[0096] 8 parts lauryl acrylate;

[0097] 3 parts mica powder;

[0098] 0.6 parts of dimethyl benzoate;

[0099] 1.5 parts of polydimethylsiloxane;

[0100] 4 parts of iron oxide red;

[0101] 8 parts of nano-alumina.

[0102] The preparation method of the coating includes the following steps:

[0103] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0104] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 1000 r / min, and mechanically mix for 40 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-mesh filter to obtain a light-curing insulating coating.

[0105] Comparative Example 2

[0106] A high-voltage resistant photocurable insulating coating, comprising the following raw materials by weight:

[0107] 35 parts of bifunctional polyurethane acrylate;

[0108] 8 parts of isoborneol acrylate;

[0109] 8 parts of isobornyl methacrylate;

[0110] 1.5 parts of phosphate acrylate;

[0111] 8 parts lauryl acrylate;

[0112] 0.6 parts of dimethyl benzoate;

[0113] 1.5 parts of polydimethylsiloxane;

[0114] 4 parts of iron oxide red;

[0115] 8 parts of nano-alumina.

[0116] The preparation method of the coating includes the following steps:

[0117] Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly;

[0118] The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 1000 r / min, and mechanically mix for 40 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-mesh filter to obtain a light-curing insulating coating.

[0119] Test case

[0120] Each coating in the examples and comparative examples was made into a load test specification coating film sample and subjected to various performance tests.

[0121] a. Adhesion test shall be conducted in accordance with standard GB / T 9286-2021;

[0122] b. Perform breakdown strength testing according to standard GB / T 1408.1-2016;

[0123] c. Place the sample in a temperature environment of 150℃, take it out after 24 hours, observe the surface phenomenon of the coating film, and evaluate the heat resistance performance.

[0124] The test results are recorded in the table below:

[0125]

[0126] Analysis of the test results shows that the coating prepared in this embodiment of the invention has excellent comprehensive performance and can meet the requirements of high-voltage power batteries. Replacing the modified mica functional material with unmodified mica powder results in two problems: firstly, it cannot be uniformly dispersed, making it difficult to form a continuous and stable barrier layer; secondly, it loses its macromolecular components, thus leading to a significant decrease in the coating's various properties. Furthermore, analysis reveals that when the modified mica functional material participates in photocuring polymerization, the abundant active alkenyl groups in the macromolecular components can generate cross-linking effects, increasing the cohesive energy of the coating's molecular chains and thus positively impacting the coating's adhesion.

[0127] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

[0128] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-voltage resistant photocurable insulating coating, characterized in that, By weight, it includes the following ingredients: 30-40 parts of bifunctional polyurethane acrylate; 8-10 parts of isoborneol acrylate; 8-10 parts of isobornyl methacrylate; 1-2 parts of phosphate acrylate; 8-10 parts lauryl acrylate; 1-3.5 parts of modified mica functional material; Photoinitiator 0.5-1 part; 1-2 parts of auxiliary agent; 3-5 parts pigment; 5-10 parts of nano-alumina; The preparation method of the modified mica functional material includes the following steps: Step 1: Use a silane coupling agent to modify the surface of mica powder to obtain surface-organic mica powder; Step 2: Add surface-organized mica powder and N,N-dimethylformamide to a nitrogen-filled reactor. After dispersing evenly, continue to add diacid linker and catalyst. After the addition is complete, raise the temperature to 70-80℃ and keep it at that temperature for 2-4 hours. Then add anthracene derivative to the reactor and stir evenly. Further raise the temperature to 80-90℃ and continue stirring and keeping it at that temperature for 9-18 hours. Then lower the temperature to 40-50℃ and add functional reagent to the reactor. Stir for 1-2 hours, then stop heating, cool down and discharge the material. Centrifuge to remove the solid material, and after washing and vacuum drying, obtain modified mica functional material. The anthracene derivative was prepared using the following method: 9,10-Di(hydroxymethyl)anthracene was added to toluene and stirred until completely dissolved. Then, epichlorohydrin and boron trifluoride diethyl ether complex were added. After the addition was complete, the temperature was raised to 60-70℃ and stirred for 2-4 hours. Then, a 10-25% sodium hydroxide aqueous solution was added and kept at this temperature for 1-2 hours under constant stirring. The solvent was evaporated and removed, the product was collected, and purified to obtain anthracene derivatives. The functional reagent is methacryloyl chloride or acryloyl chloride.

2. The high-voltage resistant photocurable insulating coating according to claim 1, characterized in that, The silane coupling agent is 3-glycidyl etheroxypropyltrimethoxysilane or 3-glycidyl etheroxypropyltriethoxysilane.

3. The high-voltage resistant photocurable insulating coating according to claim 1, characterized in that, The diacid linker is any one of 2-(4,4,5,5,6,6,6-heptafluorohexyl)malonic acid, perfluoroglutaric acid, or perfluoroazelic acid.

4. The high-voltage resistant photocurable insulating coating according to claim 1, characterized in that, The catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, N,N-dimethylbenzylamine, tetramethylammonium bromide, or tetrabutylammonium chloride.

5. The high-voltage resistant photocurable insulating coating according to claim 1, characterized in that, The molar ratio of 9,10-bis(hydroxymethyl)anthracene to epichlorohydrin is 1:

2.

6. The high-voltage resistant photocurable insulating coating according to claim 1, characterized in that, The photoinitiator is any one of benzoin dimethyl ether, photoinitiator 907, or photoinitiator 1173; the auxiliary agent is polydimethylsiloxane; and the pigment is any one of iron oxide red, titanium dioxide, or chromium oxide green.

7. A method for preparing a high-voltage resistant photocurable insulating coating as described in claim 1, characterized in that, Includes the following steps: Step 1: Weigh all the ingredients according to their weight proportions and prepare them accordingly; The second step is to add all the prepared raw materials into a high-speed mixer, control the mixing speed to 800-1000 r / min, and mechanically mix for 30-60 minutes to form a premix. Then, transfer the premix to a grinding equipment for grinding and filter it with a 200-300 mesh filter to obtain a light-curing insulating coating.

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