Photocurable heat-resistant insulating coating for lithium battery case and preparation method and application thereof

Abstract

The application discloses a light-cured heat-resistant and insulating coating for lithium battery shell, which comprises the following components in parts by weight: 25-45 parts of acrylate polymer; 10-20 parts of nine-functionality organic-inorganic hybrid polyurethane acrylate; 10-20 parts of active diluent; 5-10 parts of heat-resistant and insulating reinforcing agent; 2-5 parts of silane coupling agent; 3-8 parts of photoinitiator; 20-30 parts of filler; 0.2-1 part of defoaming agent; 0.2-1 part of wetting and leveling agent; and the acrylate polymer is alicyclic modified phenolic epoxy acrylate and / or silicone rubber acrylate. The light-cured heat-resistant and insulating coating for lithium battery shell has the characteristics of good adhesion, electrical insulation, heat resistance, corrosion resistance and high hardness.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a heat-resistant and insulating coating for a photocurable lithium battery casing, its preparation method, and its application. Background Technology

[0002] Currently, thermosetting coatings are commonly used as protective coatings for lithium battery casings, but thermosetting coatings have disadvantages such as low safety and environmental friendliness, long baking time, high energy consumption, and low production capacity. Existing UV coatings have poor heat resistance and low insulation, which cannot meet the performance requirements of high-capacity lithium battery casings.

[0003] Therefore, improving the heat resistance and insulation properties of photocurable lithium battery casing coatings is an urgent problem to be solved. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention proposes a photocurable heat-resistant insulating coating for lithium battery casings, its preparation method, and its application. The specific technical solution is as follows: A photocurable heat-resistant and insulating coating for lithium battery casings, comprising the following components by weight: 25-45 parts of acrylate polymer; 10-20 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 10-20 parts of reactive diluent; 5-10 parts of heat-resistant insulation reinforcing agent; 2-5 parts of silane coupling agent; 3-8 parts of photoinitiator; 20-30 parts of filler; Defoamer 0.2-1 part; 0.2-1 part wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate and / or a silicone rubber acrylate. The alicyclic modified phenolic epoxy acrylate used in this invention not only possesses the multifunctional groups of phenolic epoxy acrylate, but also has a high density of benzene rings in the molecule, resulting in high reactivity and high crosslinking density of the coating film. This allows it to easily form a highly crosslinked three-dimensional structure. Furthermore, the cured coating film is rich in a phenolic skeleton, thus exhibiting excellent thermal stability, mechanical strength, electrical insulation properties, and corrosion resistance. Simultaneously, the alicyclic modification reduces the internal stress between material molecules, improving coating adhesion and toughness. The silicone rubber acrylate grafted with the unique silicone rubber molecular structure further enhances the coating's strength and toughness while maintaining its high-temperature resistance and insulation properties. This improves the coating's tolerance to high and low temperature impacts and the stress generated by the expansion and contraction of the lithium battery casing, extending the coating's service life.

[0005] The nonfunctional organic-inorganic hybrid polyurethane acrylate used in this invention contains both a hard-segment ladder-shaped polysilsesquioxane structure and a soft-segment long-chain organic-inorganic hybrid resin, achieving high hardness and high toughness in the coating. Furthermore, the introduction of the ladder-shaped polysilsesquioxane organic-inorganic hybrid structure significantly improves the coating's heat resistance, electrical insulation, and corrosion resistance.

[0006] Furthermore, the heat-resistant insulation enhancer is a graphene-modified silicon-titanium nanopolymer. The graphene-modified silicon-titanium nanopolymer used in this invention, when added to the coating, significantly improves the coating's resistance to media penetration and temperature resistance through graphene's superior resistance to gas and liquid permeability and the silicon-titanium graphene network structure. The corrosion resistance of graphene, titanium, and silicon nanoparticles endows the coating with superior stability, making it less prone to reaction with acids, alkalis, salts, and other media. The coating is less likely to be consumed and form pores, and it is even less likely to react with corrosive media to generate soluble salts or cathodic loose expansion products. The coating composition and structure remain stable and undamaged over a long period. The silicon-titanium graphene network structure can improve the coating's adhesion, hardness, toughness, wear and crack resistance, heat resistance, electrical insulation, and corrosion resistance.

[0007] Further, the active diluent is one or more of the following: dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate trimethylolpropane triacrylate, pentaerythritol triacrylate, di(trimethylolpropane)tetraacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, hexanediol diacrylate, or isoborneol acrylate.

[0008] Furthermore, the silane coupling agent is one or more selected from epoxy-methoxy functional silane, vinyltris(β-methoxyethoxy)silane, γ-glycidyl etherpropyltrimethoxysilane, amino-methoxysilane, and aminopropyltrimethoxysilane.

[0009] Further, the photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone, 2-isopropylthioxanthone, or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. Furthermore, the filler is one or more selected from vacuum ceramic microspheres, hollow glass microspheres, alumina, aluminum silicate, talc, barium sulfate, or kaolin. The filler selected in this invention can enhance the electrical insulation, heat resistance, and mechanical strength of the coating.

[0010] Furthermore, the defoamer is an organosilicone defoamer.

[0011] Furthermore, the wetting and leveling agent is polyether-modified polydimethylsiloxane.

[0012] The present invention also provides a method for preparing the above-mentioned photocurable lithium battery casing heat-resistant insulating coating, characterized by comprising the following steps: The photoinitiator is dissolved in the reactive diluent, and then the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent are added and stirred to obtain the photocurable lithium battery shell heat-resistant insulation coating.

[0013] The present invention also provides the application of the above-mentioned photocurable heat-resistant insulating coating for lithium battery casing in the preparation of lithium battery casing coatings.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The effective solid content of the photocurable lithium battery heat insulation coating of the present invention is ≥98%, which is twice that of the existing solvent-based heat insulation coating (about 50%). This is equivalent to reducing the amount of coating used per unit area by half, and there is almost no VOC emission, which shows outstanding environmental performance. 2. The photocurable lithium battery heat-resistant insulating coating of the present invention has an extremely low content of flammable and explosive organic solvents, which greatly improves the safety factor compared with existing solvent-based coatings; 3. The photocurable heat-resistant insulating coating for lithium batteries of the present invention does not require high-temperature and long-term baking during use. It only requires 30-40 seconds of ultraviolet light irradiation, which reduces energy consumption and improves production efficiency. 4. The photocurable lithium battery heat-resistant insulating coating of the present invention has the characteristics of good adhesion, electrical insulation, heat resistance, corrosion resistance and high hardness. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0016] Example 1 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 45 parts of acrylate polymer; 10 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 10 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 20 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent was γ-glycidyl ether propyltrimethoxysilane, purchased from Dow Corning 6040; The photoinitiator is a mixture of 184 initiator (1-hydroxycyclohexylphenyl ketone) and TPO initiator (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) in a mass ratio of 1:1. The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK333 (polyether modified polydimethylsiloxane). The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0017] Example 2 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 35 parts of acrylate polymer; 15 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 15 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 20 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0018] Example 3 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 25 parts of acrylate polymer; 20 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 20 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 20 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0019] Example 4 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 25 parts of acrylate polymer; 10 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 17 parts of reactive diluent; 10 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 30 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1; The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd.

[0020] The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0021] Example 5 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 32 parts of acrylate polymer; 13 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 15 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 25 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0022] Example 6 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 32 parts of acrylate polymer; 13 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 15 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 25 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model UA-1020, was purchased from Zhongshan Jieshida Fine Chemical Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is an organosilicone defoamer, Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0023] Example 7 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 45 parts of acrylate polymer; 10 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 10 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 20 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.). The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipentaerythritol hexapropionate; The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent is vinyltris(β-methoxyethoxy)silane (model A-172, Momentive Corporation, USA). The photoinitiator is a mixture of 1173 initiator (2-hydroxy-2-methyl-1-phenylpropanone) and 819 initiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) in a mass ratio of 2:1. The filler is alumina; The defoamer is an organosilicone defoamer (model 6800, Deqian Company); The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0024] Comparative Example 1 Compared with Example 5, the acrylate polymer in Example 5 was replaced with an equal amount of phenolic epoxy acrylate (model U-Cure9271, purchased from Kunshan Castel Polymer Materials Co., Ltd.), and the remaining components and preparation process were the same as in Example 5.

[0025] Comparative Example 2 Compared with Example 5, the nonfunctional organic-inorganic hybrid polyurethane acrylate in Example 5 was replaced with an equal amount of nonfunctional polyurethane acrylate resin (model B-919B, purchased from Guangdong Boxin New Material Technology Co., Ltd.), and the remaining components and preparation process were the same as in Example 5.

[0026] Comparative Example 3 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 42 parts of acrylate polymer; 15 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 15 parts reactive diluent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 20 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The silane coupling agent is Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above ratio, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0027] Comparative Example 4 A photocurable heat-resistant and insulating coating for lithium battery casings, in parts by weight: 25 parts of acrylate polymer; 10 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 10 parts reactive diluent; 7 parts of heat-resistant insulation reinforcing agent; 2 parts of silane coupling agent; 5 parts of photoinitiator; 40 parts of filler; 0.5 parts of defoamer; 0.5 parts of wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate (model WDS-5709, purchased from Wuxi Vidos Electronic Materials Co., Ltd.) and a silicone rubber acrylate (model PAR-97, purchased from Shenzhen Sabis Technology Co., Ltd.), with a mass ratio of 2:1. The nine-functional organic-inorganic hybrid polyurethane acrylate, model FJ-7273, was purchased from Dongguan Fengjin New Materials Co., Ltd. The reactive diluent is dipropylene glycol diacrylate and dipentaerythritol pentaacrylate in a mass ratio of 2:1. The heat-resistant insulation reinforcing agent is a graphene-modified silicon-titanium nanopolymer, purchased from Changsha Tianyuan Xiwang Materials Technology Co., Ltd. The silane coupling agent was γ-glycidyl ether propyltrimethoxysilane, purchased from Dow Corning 6040; The photoinitiator is a mixture of 184 initiator and TPO initiator in a mass ratio of 1:1; The filler is vacuum ceramic microspheres with a particle size of 5-10 micrometers; The defoamer is Shin-Etsu KSZ-108 from Japan; The wetting and leveling agent is BYK 333; The preparation method of the heat-resistant insulating coating for the casing of a photocurable lithium battery includes the following steps: Weigh each component according to the above proportions, dissolve the photoinitiator in the reactive diluent, and then add the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer, and the wetting and leveling agent. Stir evenly to obtain a photocurable lithium battery heat-resistant insulating coating.

[0028] Unless otherwise specified, the word "parts" in this instruction manual means "parts by weight".

[0029] <Test Standards> The performance test standards for each embodiment and comparative example of the present invention are as follows, and the test results are shown in Table 1: Adhesion: Adhesion is tested according to GB / T9286-1998. The adhesion grades from best to worst are "0", "1", "2", and "3". Hardness: The hardness is tested according to GB / T6739-2022, with the unit being H. The hardness is required to be not less than 3H. Electrical insulation performance: According to GB / T 1981.2-2009 "Electrical Insulation Paints - Part 2: Test Methods", the volume resistivity at a DC voltage of 500V (DC500V) is tested in Ω, and the volume resistivity is required to be greater than 10¹²Ω. Electrical strength test: The electrical strength is tested according to GB / T 1408.1-2006 "Electrical strength test method for insulating materials - Part 1: Test under power frequency", with the unit being kV / mm. The electrical strength is required to be greater than 38 kV / mm. Heat resistance aging test: The heat resistance aging time is tested according to GB / T 11026.1-2003 "Heat resistance of electrical insulation materials - Part 1: Aging procedures and evaluation of test results", in hours. The heat resistance aging time is required to be greater than 4200 hours.

[0030] Salt spray resistance test: The salt spray resistance time is tested according to GB / T10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", with the unit being hours. The salt spray resistance time is required to be greater than 4000 hours.

[0031] Table 1.

[0032] As shown in Table 1, the photocurable heat-resistant insulating coating for lithium battery casings prepared by this invention exhibits excellent performance in terms of adhesion, hardness, electrical insulation, heat resistance, and corrosion resistance. Comparative Example 1, due to the use of unmodified phenolic epoxy acrylate, resulted in a hard and brittle coating with poor adhesion, and decreased heat resistance and corrosion resistance. Comparative Example 2, by using a 9-functionality polyurethane acrylate instead of an organic-inorganic hybrid resin, resulted in large volume shrinkage during curing, poor adhesion, and decreased insulation, heat resistance, and corrosion resistance. Comparative Example 3, by not using a heat-resistant insulating reinforcing agent, resulted in decreased insulation, heat resistance, and corrosion resistance. Comparative Example 4, by using excessive amounts of vacuum ceramic microspheres, resulted in poor resin encapsulation of the filler, a hard and brittle coating, poor adhesion, and decreased electrical insulation, heat resistance, and corrosion resistance.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The application of a photocurable heat-resistant insulating coating for lithium battery casings in the preparation of lithium battery casing coatings, characterized in that, The photocurable lithium battery casing heat-resistant insulating coating comprises the following components by weight: 25-45 parts of acrylate polymer; 10-20 parts of a nine-functional organic-inorganic hybrid polyurethane acrylate; 10-20 parts of reactive diluent; 5-10 parts of heat-resistant insulation reinforcing agent; 2-5 parts of silane coupling agent; 3-8 parts of photoinitiator; 20-25 parts of filler; Defoamer 0.2-1 part; 0.2-1 part wetting and leveling agent; The acrylate polymer is an alicyclic modified phenolic epoxy acrylate and a silicone rubber acrylate; the heat-resistant insulating reinforcing agent is a graphene modified silicon-titanium nanopolymer; the filler is one or more of vacuum ceramic microspheres, glass hollow microspheres, alumina, aluminum silicate, talc, barium sulfate or kaolin; the nine-functional organic-inorganic hybrid polyurethane acrylate is model FJ-7273.

2. The application according to claim 1, characterized in that, The active diluent is one or more of the following: dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, di(trimethylolpropane)tetraacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, hexanediol diacrylate, or isoborneol acrylate.

3. The application according to claim 1, characterized in that, The silane coupling agent is one or more of vinyltris(β-methoxyethoxy)silane, γ-glycidyl etherpropyltrimethoxysilane, and aminopropyltrimethoxysilane.

4. The application according to claim 1, characterized in that, The photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone, 2-isopropylthioxanthone, or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

5. The application according to claim 1, characterized in that, The defoamer is an organosilicone defoamer.

6. The application according to claim 1, characterized in that, The wetting and leveling agent is polyether-modified polydimethylsiloxane.

7. A method for preparing a heat-resistant and insulating coating for a photocurable lithium battery casing according to any one of claims 1-6, characterized in that, Includes the following steps: The photoinitiator is dissolved in the active diluent, and then the acrylate polymer, the nine-functional organic-inorganic hybrid polyurethane acrylate, the heat-resistant insulation reinforcing agent, the silane coupling agent, the defoamer and the wetting and leveling agent are added and stirred to obtain the photocurable lithium battery shell heat-resistant insulation coating.

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