A photocurable ink, insulating coating, battery case, method for producing the same, and battery

Abstract

This application provides a photocurable ink, an insulating coating, a battery casing, a method for preparing the same, and a battery. The photocurable ink comprises acrylic resin, an active monomer, and an initiator. The initiator promotes the polymerization reaction between the active monomer and the acrylic resin, thereby enabling the photocurable ink to cure. The initiator includes a deep-curing initiator, a shallow-curing initiator, and an amine co-initiator. The deep-curing initiator has an absorption wavelength of 300nm-400nm. The deep-curing initiator ensures that it can be effectively activated to generate free radicals even in deep regions, achieving deep curing. The shallow-curing initiator forms an excited state under light irradiation. The excited-state shallow-curing initiator abstracts hydrogen atoms from the amine co-initiator, generating active free radicals and amine free radicals. The amine free radicals can react with oxygen to generate peroxide amines, improving oxygen inhibition. During the curing of the photocurable ink, both surface and bottom layers can be cured simultaneously, thereby improving the mechanical properties of the insulating coating.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a photocurable ink, an insulating coating, a battery casing, a method for preparing the same, and a battery. Background Technology

[0002] Currently, lithium-ion batteries generally have an aluminum casing. In order to improve the insulation performance of the lithium-ion battery surface, a spray printing process is generally used to spray an insulating ink onto the aluminum casing surface. Then, the insulating ink is photocured to obtain an integrated insulating coating.

[0003] However, during the curing process of insulating ink, due to oxygen inhibition, the surface ink is prone to incomplete curing, resulting in the bottom layer of the insulating coating curing while the surface layer remains uncured, which reduces the mechanical properties of the insulating coating and needs further improvement. Summary of the Invention

[0004] The embodiments of this application provide a photocurable ink, an insulating coating, a battery casing, a method for preparing the same, and a battery, aiming to solve the aforementioned technical problems.

[0005] In a first aspect, embodiments of this application provide a photocurable ink, comprising: an acrylic resin, an active monomer, and an initiator;

[0006] The initiator includes a deep curing initiator, a shallow curing initiator, and an amine co-initiator. The absorption wavelength of the deep curing initiator is 300nm-400nm, and the shallow curing initiator includes thioxanthone compounds.

[0007] In one embodiment, the initiator has an absorption wavelength of 365 nm or 395 nm; and / or

[0008] The deep curing initiator in the photocurable ink has a mass percentage of 2%-5%; and / or

[0009] The sum of the masses of the shallow curing initiator and the amine co-initiator constitutes 1%-3% of the mass percentage of the photocurable ink; and / or

[0010] The mass ratio of the shallow curing initiator to the amine co-initiator is 1:(0.2-0.5); and / or

[0011] The initiator in the photocurable ink has a mass percentage of 3%-8%; and / or

[0012] The active monomer in the photocurable ink has a mass percentage of 25%-50%; and / or

[0013] The acrylic resin constitutes 40%-60% by mass in the UV-curable ink.

[0014] In one embodiment, the deep curing initiator comprises at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolithyl)dicentectan, bis2,6-difluoro-3-pyrrolithyldicentectan, 2-hydroxy-2-methyl-1-phenylpropanone, and 1-hydroxycyclohexylphenyl ketone; and / or

[0015] The thioxanthone compounds include at least one of 2-chlorothioxanthone, isopropylthioxanthone, and 2,4-diethylthioxanthone; and / or

[0016] The amine co-initiator includes at least one of an active amine and a tertiary amine benzoate; and / or

[0017] The acrylic resin includes polycarbonate-type polyurethane acrylate and linear aliphatic epoxy acrylate; and / or

[0018] The active monomers include monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers, wherein the functionality of the polyfunctional acrylate monomers is greater than or equal to 3.

[0019] In one embodiment, the active amine includes at least one selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophorone diamine, and 1,2-cyclohexanediamine; and / or

[0020] The tertiary amine benzoate comprises at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethylformate, and 2-ethylhexyl N,N-dimethylbenzoate; and / or

[0021] The monofunctional acrylate monomers include at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate; and / or

[0022] The bifunctional acrylate monomers include at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; and / or

[0023] The multifunctional acrylate monomers include at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tri(2-hydroxyethyl)isocyanurate triacrylate.

[0024] In one embodiment, the mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer, and the polyfunctional acrylate monomer is (3-5):1:(0.3-0.5); and / or

[0025] The polycarbonate-type polyurethane acrylate has a molecular weight of 500-1200; and / or

[0026] The linear aliphatic epoxy acrylate has a molecular weight of 500-1200; and / or

[0027] The mass ratio of the polycarbonate-type polyurethane acrylate to the linear aliphatic epoxy acrylate is (0.5-3):1; and / or

[0028] The polycarbonate-type polyurethane acrylate has the general structural formula shown in formula (1):

[0029]

[0030] In structural formula (1), R1 is selected from a benzene ring or a C1-C6 substituted or unsubstituted alkyl group, and / or R2 is selected from a substituted or unsubstituted cyclohexyl group, and / or R3 and R4 are each independently selected from a C1-C6 substituted or unsubstituted alkyl group, and / or n is selected from an integer from 1 to 10, and / or m is selected from an integer from 1 to 10; and / or

[0031] The linear aliphatic epoxy acrylate has the general structural formula shown in formula (2):

[0032]

[0033] In structural formula (2), R1 is selected from C1-C10 substituted or unsubstituted straight-chain or branched alkyl groups, and / or x is selected from integers from 1 to 6.

[0034] In one embodiment, the photocurable ink further includes pigments, wetting agents, polymerization inhibitors, and / or diluents.

[0035] In one embodiment, the wetting agent comprises at least one of polyether-modified silicone and polyester-modified silicone; and / or

[0036] The polymerization inhibitor includes at least one of hydroquinone and p-methoxyphenol; and / or

[0037] The diluent includes at least one of isoborneol acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate. The test results are shown in Table 3.

[0038] In one embodiment, the pigment in the ink has a mass percentage of 0.5-1%; and / or

[0039] The wetting agent in the ink comprises 0.5-2.5% by mass; and / or

[0040] The polymerization inhibitor is present in the ink at a mass percentage of 0.1-0.5%; and / or

[0041] The diluent in the ink has a mass percentage of 4-5%; and / or

[0042] The pigment has a particle size D50 ≤ 0.4 μm.

[0043] Secondly, embodiments of this application also provide an insulating coating formed from the photocurable ink described above.

[0044] Thirdly, embodiments of this application also provide a battery casing, comprising:

[0045] Main body;

[0046] An insulating coating is disposed on at least a portion of the outer surface of the main body, and the insulating coating is formed from the photocurable ink as described above.

[0047] Fourthly, embodiments of this application also provide a method for preparing a battery casing, the method comprising:

[0048] The main body provides the battery casing;

[0049] Using the photocurable ink described above as a raw material, an ink layer is formed by spraying onto at least a portion of the outer surface of the main body;

[0050] The ink layer is cured by ultraviolet light to form an insulating coating, thus obtaining the battery casing.

[0051] In one embodiment, the thickness of the ink layer is 50 μm-150 μm; and / or

[0052] The ultraviolet light source includes an LED lamp, and / or the wavelength of the ultraviolet light is 365nm or 395nm, and / or the curing time is 1s-10s.

[0053] Fifthly, embodiments of this application also provide a battery, including the insulating coating as described above, or including the battery casing as described above, or a battery casing prepared using the method described above.

[0054] The beneficial effects of the embodiments of this application are as follows:

[0055] The photocurable ink of this application embodiment includes acrylic resin, reactive monomers, and an initiator. The initiator promotes the polymerization reaction between the reactive monomers and the acrylic resin, thereby enabling the photocurable ink to cure. The initiator includes a deep-curing initiator, a shallow-curing initiator, and an amine co-initiator. The deep-curing initiator has an absorption wavelength of 300nm-400nm. Generally, the longer the wavelength of light, the better its ability to penetrate materials. Therefore, inks in deeper regions typically require longer wavelengths of light for photocuring. Since the deep-curing initiator has an absorption wavelength of 300nm-400nm, it can absorb and match longer wavelengths of light, ensuring that the deep-curing initiator can be effectively activated to generate free radicals even in deeper regions, thereby achieving deep curing. 。 Shallow curing initiators include thioxanthone compounds. Due to their high absorption efficiency and rapid initiation ability, thioxanthone compounds can meet the requirements of surface curing. Under light irradiation, thioxanthone compounds form an excited state. The electron-rich sulfur atoms in the molecular structure of thioxanthone compounds enhance the molecule's ability to absorb light, enabling the excited state to be generated efficiently. The excited-state thioxanthone compounds abstract hydrogen atoms from amine co-initiators through intramolecular hydrogen abstraction reactions, generating active free radicals and amine free radicals. The amine free radicals can react with oxygen to generate peroxide amines, thereby consuming oxygen in the surface area and reducing oxygen interference with surface curing. This allows the surface area to complete surface curing before oxygen diffuses to the reaction interface, improving oxygen inhibition problems and enhancing the surface curing effect of the coating. When photocuring inks, surface curing and underlayer curing can be achieved simultaneously, resulting in a uniform distribution of shrinkage stress during curing, reducing local stress concentration, and ensuring uniform cross-linking of the insulating coating, thereby improving the overall strength of the coating and ultimately improving the mechanical properties of the insulating coating. Detailed Implementation

[0056] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation; while "inner" and "outer" refer to the outline of the device.

[0057] In related technologies, during the curing process of insulating ink, due to oxygen inhibition, the surface ink is prone to incomplete curing, resulting in the bottom layer of the insulating coating curing while the surface layer remains uncured, which needs further improvement.

[0058] This application provides a photocurable ink comprising an acrylic resin, an active monomer, and an initiator. The initiator promotes the polymerization reaction between the active monomer and the acrylic resin, thereby enabling the photocurable ink to cure. The initiator includes a deep-curing initiator, a shallow-curing initiator, and an amine co-initiator. The deep-curing initiator has an absorption wavelength of 300nm-400nm. Generally, the longer the wavelength of light, the better its ability to penetrate materials. Therefore, inks in deeper regions typically require longer wavelengths of light for photocuring. Since the deep-curing initiator has an absorption wavelength of 300nm-400nm, it can absorb and match longer wavelengths of light, ensuring that the deep-curing initiator can be effectively activated to generate free radicals even in deeper regions, thus achieving deep curing. 。 Shallow curing initiators include thioxanthone compounds. Due to their high absorption efficiency and rapid initiation ability, thioxanthone compounds can meet the requirements of surface curing. Under light irradiation, thioxanthone compounds form an excited state. The electron-rich sulfur atoms in the molecular structure of thioxanthone compounds enhance the molecule's ability to absorb light, enabling the excited state to be generated efficiently. The excited-state thioxanthone compounds abstract hydrogen atoms from amine co-initiators through intramolecular hydrogen abstraction reactions, generating active free radicals and amine free radicals. The amine free radicals can react with oxygen to generate peroxide amines, thereby consuming oxygen in the surface area and reducing oxygen interference with surface curing. This allows the surface area to complete surface curing before oxygen diffuses to the reaction interface, improving oxygen inhibition problems and enhancing the surface curing effect of the coating. When photocuring inks, surface curing and underlayer curing can be achieved simultaneously, resulting in a uniform distribution of shrinkage stress during curing, reducing local stress concentration, and ensuring uniform cross-linking of the insulating coating, thereby improving the overall strength of the coating and ultimately improving the mechanical properties of the insulating coating.

[0059] In one embodiment, the absorption wavelength of the initiator is 365 nm or 395 nm. It should be noted that the initiator is a composition including a deep-curing initiator, a shallow-curing initiator, and an amine co-initiator. The absorption wavelength of the initiator refers to the threshold required for the composition to absorb light and initiate curing. When the absorption wavelength of the initiator is 365 nm or 395 nm, an initiator containing multiple components can exhibit significant absorption at wavelengths of 365 nm or 395 nm and efficiently initiate polymerization reactions. Since the wavelength range of light emitted by electrodeless lamps is generally 200 nm-450 nm, the requirements for initiator selection are low. Therefore, electrodeless lamps are used as light sources for photocuring in the market. However, electrodeless lamps have disadvantages such as severe heat generation, high equipment temperature, short lifespan, and high cost, which limit their large-scale application. LED lamps, on the other hand, have advantages such as low heat generation, long equipment lifespan, and low cost, and can be widely used in the photocuring of inks. However, the wavelength range of ultraviolet light emitted by LED lamps is relatively narrow, typically around 365nm or 395nm, which places high demands on the type of initiator. In this embodiment, the initiator's absorption wavelength is 365nm or 395nm, highly matching the wavelength of the ultraviolet light emitted by the LED lamp. This allows the ultraviolet light emitted by the LED lamp to be effectively absorbed by the initiator, efficiently initiating the photocuring reaction. Therefore, in this embodiment, through the synergistic effect of the deep-curing initiator, shallow-curing initiator, and amine co-initiator, the initiator containing multiple components achieves an absorption wavelength of 365nm or 395nm. This allows the photocurable ink to use LED lamps as the light source, reducing equipment lifespan and cost while ensuring good curing performance.

[0060] In one embodiment, the mass percentage of the deep-curing initiator in the UV-curable ink is 2%-5%. Optionally, the mass percentage of the deep-curing initiator in the UV-curable ink can be any one or any two of 2%, 3%, 4%, 5%, etc., and is not limited herein. In this embodiment, when the mass percentage of the deep-curing initiator in the UV-curable ink is too high or too low, it can easily lead to a problem of poor consistency between the surface and deep curing degrees of the insulating coating.

[0061] In one embodiment, the total mass percentage of the shallow-curing initiator and the amine co-initiator in the UV-curable ink is 1%-3%. Optionally, the total mass percentage of the shallow-curing initiator and the amine co-initiator in the UV-curable ink can be any one or any two of 1%, 1.5%, 2%, 2.5%, 3%, etc., and is not limited herein. In this embodiment, when the total mass of the shallow-curing initiator and the amine co-initiator is too large, it can easily lead to excessively rapid curing of the ink surface, forming an uneven surface. Defects such as orange peel and pinholes may appear on the surface of the insulating coating, affecting the appearance and performance of the insulating coating. When the total mass of the shallow-curing initiator and the amine co-initiator is too small, it can easily lead to incomplete curing of the ink surface.

[0062] In one embodiment, the mass ratio of the shallow curing initiator to the amine co-initiator is 1:(0.2-0.5). Optionally, the mass ratio of the shallow curing initiator to the amine co-initiator can be any one or any two of 1:0.2, 1:0.3, 1:0.4, 1:0.5, etc., and is not limited herein. In this embodiment, the shallow curing initiator mainly promotes ink curing by generating free radicals with the amine co-initiator through a hydrogen abstraction reaction. When the mass ratio of the shallow curing initiator to the amine co-initiator is too low, it is easy to result in too few free radicals generated by the shallow curing initiator, and the amine co-initiator has low initiation efficiency alone, resulting in slower curing speed and incomplete surface curing. When the mass ratio of the shallow curing initiator to the amine co-initiator is too high, it is easy to result in too little amine co-initiator content, and the effect of the amine co-initiator in improving oxygen inhibition is not ideal.

[0063] In one embodiment, the initiator comprises 3%-8% by mass in the UV-curable ink. Optionally, the initiator may be any one or any two of 3%, 4%, 5%, 6%, 8%, etc., and is not limited herein. In this embodiment, excessive initiator content can lead to excessively rapid curing, potentially causing internal stress or cracks in the insulating coating. Insufficient initiator content can result in incomplete curing, affecting the mechanical strength and durability of the insulating coating.

[0064] In one embodiment, the deep curing initiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolithyl)dicenzolide, bis(2,6-difluoro-3-pyrrolithyl)dicenzolide, 2-hydroxy-2-methyl-1-phenylpropanone, and 1-hydroxycyclohexylphenyl methyl ketone.

[0065] In one embodiment, the thioxanthone compound includes at least one of 2-chlorothioxanthone, isopropylthioxanthone, and 2,4-diethylthioxanthone.

[0066] In one embodiment, the amine co-initiator includes at least one of an active amine and a tertiary amine benzoate.

[0067] In one embodiment, the active amine includes at least one selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophorone diamine, and 1,2-cyclohexanediamine.

[0068] In one embodiment, the tertiary amine benzoate includes at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethylformate, and 2-ethylhexyl N,N-dimethylbenzoate.

[0069] In one embodiment, the mass percentage of the active monomer in the UV-curable ink is 25%-50%. Optionally, the mass percentage of the active monomer in the UV-curable ink can be any one or any two of 25%, 30%, 35%, 40%, 50%, etc., and is not limited herein. In this embodiment, if the mass percentage of the active monomer in the UV-curable ink is too high, the excess active monomer can easily reduce the crosslinking density of the acrylic resin, leading to a decrease in the mechanical properties of the insulating coating; in addition, the more active monomers there are, the higher the UV energy required for complete curing, and with limited UV energy, too much active monomer can easily lead to incomplete curing. Active monomers can reduce the viscosity of the UV-curable ink. If the mass percentage of the active monomer in the UV-curable ink is too low, the viscosity of the UV-curable ink can easily increase, limiting the penetration of ultraviolet light into the UV-curable ink, resulting in poor curing effect.

[0070] In one embodiment, the active monomers include monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers, wherein the functionality of the polyfunctional acrylate monomers is greater than or equal to 3. In this embodiment, monofunctional acrylate monomers can increase the flexibility and adhesion of the insulating coating, while difunctional and polyfunctional acrylate monomers can improve the electrical insulation, electrolyte resistance, and crosslinking density of the insulating coating. The combined use of monofunctional, difunctional, and polyfunctional acrylate monomers can produce a synergistic effect, improving the flexibility, electrical insulation, solvent resistance, and adhesion of the insulating coating.

[0071] In one embodiment, the monofunctional acrylate monomer includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate.

[0072] In one embodiment, the bifunctional acrylate monomer includes at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate.

[0073] In one embodiment, the multifunctional acrylate monomer includes at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tri(2-hydroxyethyl)isocyanurate triacrylate.

[0074] In one embodiment, the mass ratio of monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers is (3-5):1:(0.3-0.5). Optionally, the mass ratio of monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers can be any one or any two of 3:1:0.5, 4:1:0.5, 5:1:0.5, 3:1:0.4, 5:1:0.3, etc., and is not limited herein. In this embodiment, when the mass of monofunctional acrylate monomers is too high and the mass of polyfunctional acrylate monomers is too low, it is easy to lead to a low crosslinking density and poor high-temperature resistance of the insulating coating. When the mass of monofunctional acrylate monomers is too low and the mass of polyfunctional acrylate monomers is too high, it is easy to lead to incomplete curing of the insulating coating, stickiness of the insulating coating, easy cracking of the insulating coating, and poor aging resistance.

[0075] In one embodiment, the mass percentage of acrylic resin in the UV-curable ink is 40%-60%. Optionally, the mass percentage of acrylic resin in the UV-curable ink can be any one or any two of 40%, 45%, 50%, 55%, 60%, etc., and is not limited herein.

[0076] In one embodiment, the acrylic resin includes polycarbonate-type polyurethane acrylate and linear aliphatic epoxy acrylate. The polycarbonate-type polyurethane acrylate has carbonate groups, which have low polarity and are less prone to chemical reactions, giving it good hydrolysis resistance and chemical corrosion resistance. This makes the insulating coating less prone to aging, decomposition, and yellowing during high temperature, high humidity, and long-term use. The linear aliphatic epoxy acrylate maintains the high insulation performance of epoxy resin itself. Furthermore, the linear structure of the linear aliphatic epoxy acrylate gives the insulating coating good hydrophobic properties, further improving its hydrophobicity. The combined use of polycarbonate-type polyurethane acrylate and linear aliphatic epoxy acrylate can improve the overall performance of the insulating coating.

[0077] In one embodiment, the molecular weight of the polycarbonate-type polyurethane acrylate is 500-1200. Optionally, the molecular weight of the polycarbonate-type polyurethane acrylate can be any one or any two of 500, 700, 800, 900, 1000, 1200, etc., and is not limited herein. In this embodiment, the molecular weight of the polycarbonate-type polyurethane acrylate is set to 500-1200 so that the UV-curable ink has a suitable viscosity, reducing ink tailing, clogging, and other phenomena when spraying the UV-curable ink.

[0078] In one embodiment, the molecular weight of the linear aliphatic epoxy acrylate is 500-1200; optionally, the molecular weight of the linear aliphatic epoxy acrylate can be any one or any two of 500, 700, 800, 900, 1000, 1200, etc., and is not limited herein. In this embodiment, the molecular weight of the linear aliphatic epoxy acrylate is set to 500-1200 so that the UV-curable ink has a suitable viscosity, reducing ink tailing, clogging, and other phenomena during UV-curable ink spraying.

[0079] In one embodiment, the mass ratio of polycarbonate-type polyurethane acrylate to linear aliphatic epoxy acrylate is (0.5-3):1. Optionally, the mass ratio of polycarbonate-type polyurethane acrylate to linear aliphatic epoxy acrylate can be any one or any two of 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc., and is not limited herein. In this embodiment, when the mass ratio of polycarbonate-type polyurethane acrylate to linear aliphatic epoxy acrylate is too small, it is easy to result in too little polycarbonate-type polyurethane acrylate and too much linear aliphatic epoxy acrylate, reducing the insulation performance of the coating. When the mass ratio of polycarbonate-type polyurethane acrylate to linear aliphatic epoxy acrylate is too large, it is easy to result in too much polycarbonate-type polyurethane acrylate and too little linear aliphatic epoxy acrylate, reducing the chemical corrosion resistance of the insulating coating and making the insulating coating prone to aging, decomposition, and yellowing during high temperature, high humidity, and long-term use.

[0080] In one embodiment, the polycarbonate-type polyurethane acrylate has the general structural formula shown in formula (1):

[0081] In the structural formula (1), R1 is selected from a benzene ring or a C1-C6 substituted or unsubstituted alkyl group, and / or R2 is selected from a substituted or unsubstituted cyclohexyl group, and / or R3 and R4 are each independently selected from a C1-C6 substituted or unsubstituted alkyl group, and / or n is selected from an integer from 1 to 10, and / or m is selected from an integer from 1 to 10.

[0082] In one embodiment, the polycarbonate-type polyurethane acrylate represented by structural formula (1) can be prepared by the following method:

[0083] S11. A diol compound having the structure shown in Formula 1 and dimethyl carbonate are added to a reactor vessel and mixed thoroughly to obtain a first mixture. Calcium oxide is added to the first mixture as a catalyst, and the reaction is carried out at an ambient temperature of 100℃-160℃ for 0.5h-5h to obtain polycarbonate diol as shown in Formula 2. The molar ratio of the diol compound to dimethyl carbonate is (2-5):1, and the mass percentage of the catalyst in the first mixture is 0.1%-1%. The reaction formula is as follows:

[0084]

[0085] S12. Acetone solvent and isocyanate compounds are added to a reactor vessel, and the polycarbonate diol and isocyanate compounds are reacted at an ambient temperature of 60℃-90℃ for 6h-12h to obtain the intermediate shown in Formula 3; wherein the molar ratio of isocyanate compound to diol compound is 2:1, and the reaction formula is as follows:

[0086]

[0087] S13. An acrylate having the structure shown in Formula 4 is added to a reactor vessel, and the intermediate and the acrylate are reacted at an ambient temperature of 60℃-90℃ for 6h-12h to obtain a polycarbonate-type polyurethane acrylate having the structure shown in Formula (1); wherein the molar ratio of acrylate to diol compound is 2:1, and the reaction formula is as follows:

[0088]

[0089] In one embodiment, the linear aliphatic epoxy acrylate has the general structural formula shown in formula (2):

[0090]

[0091] In structural formula (2), R1 is selected from C1-C10 substituted or unsubstituted straight-chain or branched alkyl groups, and x is selected from integers from 1 to 6.

[0092] In this embodiment, the linear aliphatic epoxy acrylate maintains the high insulation performance of the epoxy resin itself. In addition, the linear aliphatic epoxy acrylate has a longer linear alkane chain segment. The linear alkane chain segment has low motion resistance, which makes the linear aliphatic epoxy acrylate have good photocuring activity, improves photocuring efficiency, and accelerates crosslinking speed. At the same time, the longer linear alkane chain segment has a better hydrophobic effect, which can improve the hydrophobic performance of the insulating coating.

[0093] In one embodiment, the linear aliphatic epoxy acrylate represented by structural formula (2) can be prepared by the following method:

[0094] Acrylic acid and diglycidyl ether having the structure shown in Formula 5 were added to a reactor containing acetone solvent and mixed thoroughly to obtain a mixture. Triethylamine was added to the mixture as a catalyst, and the mixture was reacted at an ambient temperature of 30℃-100℃ for 2-10 hours to obtain a linear aliphatic epoxy acrylate with the structure shown in Formula (2). The molar ratio of acrylic acid to diglycidyl ether was 2:1, and the mass percentage of the catalyst in the mixture was 0.05%-1%. The reaction formula is as follows:

[0095]

[0096] In one embodiment, the photocurable ink further includes pigments, wetting agents, polymerization inhibitors, and / or diluents.

[0097] In one embodiment, the wetting agent comprises at least one of polyether-modified silicone and polyester-modified silicone. The wetting agent can improve the spreadability and anti-cratering properties of UV-curable inks.

[0098] In one embodiment, the wetting agent in the UV-curable ink comprises 0.5% to 2.5% by mass. Optionally, the wetting agent in the UV-curable ink may be any one or any two of 0.5%, 1%, 1.5%, 2%, 2.5%, etc., and is not limited herein.

[0099] In one embodiment, the polymerization inhibitor includes at least one of hydroquinone and p-methoxyphenol. The polymerization inhibitor can improve the storage stability of the photocurable ink.

[0100] In one embodiment, the mass percentage of the polymerization inhibitor in the UV-curable ink is 0.1%-0.5%; optionally, the mass percentage of the polymerization inhibitor in the UV-curable ink can be any one or any two of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc., without limitation herein.

[0101] In one embodiment, the diluent includes at least one of isoborneol acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate.

[0102] In one embodiment, the mass percentage of the diluent in the UV-curable ink is 4%-5%; alternatively, the mass percentage of the diluent in the UV-curable ink can be any one or any two of 4%, 4.2%, 4.6%, 4.8%, 5%, etc., without limitation herein.

[0103] In one embodiment, the pigment in the UV-curable ink is 0.5%-1% by mass. Optionally, the pigment in the UV-curable ink may be any one or any two of 0.5%, 0.6%, 0.7%, 0.8%, 1%, etc., without limitation herein.

[0104] In one embodiment, the pigment particle size D50 ≤ 0.4 μm.

[0105] In one embodiment, the pigment includes at least one of phthalocyanine blue powder, phthalocyanine green powder, and titanium dioxide.

[0106] This application also provides a method for preparing a photocurable ink, comprising: adding acrylic resin, active monomer, initiator and other raw materials into a double planetary mixer, and dispersing them at 500r / min-1000r / min for 0.5h-1h to obtain the photocurable ink.

[0107] This application also provides an insulating coating formed from the photocurable ink described above.

[0108] This application also provides a battery casing, including a main body and an insulating coating. The insulating coating is disposed on at least a portion of the outer surface of the main body and is formed by the photocurable ink described above. In this embodiment, the main body can be made of a material with a certain hardness and strength. The main body can be made of materials such as copper, iron, aluminum, stainless steel, and aluminum alloy, and is not limited thereto. The shape of the main body is also not limited; the shape of the main body can be cuboid, cylindrical, hexagonal prism, etc., and is not limited thereto.

[0109] This application also provides a method for preparing a battery casing, comprising:

[0110] S01, A main body providing a battery casing;

[0111] S02. Using the photocurable ink as described above as raw material, an ink layer is formed by spraying it onto at least a portion of the outer surface of the main body.

[0112] S03. The ink layer is cured by ultraviolet light to form an insulating coating, thus obtaining the battery casing.

[0113] In this embodiment, an ink layer is sprayed onto the surface of the main body using a spraying process, and then cured by ultraviolet light. The ink layer can be cured in situ on the surface of the main body, which can improve the adhesion of the insulating coating to the main body. At the same time, the insulating coating has good flexibility and thermal shrinkage resistance, and the insulating coating is not prone to brittleness and thermal shrinkage.

[0114] In one embodiment, the thickness of the ink layer is 50μm-150μm; optionally, the thickness of the ink layer can be any one or any two of 50μm, 80μm, 100μm, 120μm, 150μm, etc., and is not limited herein.

[0115] In one embodiment, the light source for ultraviolet light includes an LED lamp, and / or the wavelength of the ultraviolet light is 365nm or 395nm, and / or the curing time is 1s-10s.

[0116] This application also provides a battery, including the insulating coating as described above, or including the battery casing as described above, or a battery casing prepared using the method described above. In this embodiment, the type of battery is not limited; the battery may be a lithium-ion battery, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery.

[0117] The present application will be further described below through specific embodiments.

[0118] Example 1

[0119] This embodiment provides a photocurable ink, which includes acrylic resin, reactive monomers, initiators, pigments, wetting agents, polymerization inhibitors, and diluents; wherein:

[0120] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The absorption wavelength of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is 382 nm. The mass percentage of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide in the UV-curable ink is 5%, the mass percentage of 2-chlorothionanone in the UV-curable ink is 1%, and the mass percentage of ethylenediamine in the UV-curable ink is 0.2%. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0121] The acrylic resin accounts for 45% of the mass of the UV-curable ink. The acrylic resin is composed of polycarbonate-type polyurethane acrylate and linear aliphatic epoxy acrylate, with a mass ratio of 0.5:1 between the polycarbonate-type polyurethane acrylate and the linear aliphatic epoxy acrylate.

[0122] The active monomer in the photocurable ink has a mass percentage of 40.3%. The active monomer is composed of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate, and the mass ratio between isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 5:1:0.3.

[0123] The pigment in the UV-curable ink is 0.7% by mass, and the pigment is titanium dioxide.

[0124] The wetting agent in the UV-curable ink has a mass percentage of 2.3%, and the wetting agent is polyether-modified silicone.

[0125] The polymerization inhibitor has a mass percentage of 0.5% in the UV-curable ink, and the polymerization inhibitor is p-methoxyphenol;

[0126] The diluent in the UV-curable ink is 5% by mass, and the diluent is lauryl acrylate.

[0127] Example 2

[0128] The main difference between Example 2 and Example 1 is:

[0129] The initiator comprises 8% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5% by mass in the UV-curable ink, 2% by mass in the UV-curable ink, and 1% by mass in the UV-curable ink. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.5.

[0130] The diluent accounts for 3.2% by mass in the UV-curable ink;

[0131] The rest is the same as in Example 1.

[0132] Example 3

[0133] The main difference between Example 3 and Example 1 is:

[0134] The initiator comprises 8% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5% by mass in the UV-curable ink, 2.5% by mass in the UV-curable ink, and 0.5% by mass in the UV-curable ink. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0135] The diluent accounts for 3.2% by mass in the UV-curable ink;

[0136] The rest is the same as in Example 1.

[0137] Example 4

[0138] The main difference between Example 4 and Example 1 is:

[0139] The initiator comprises 3% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 2% by mass in the UV-curable ink, 0.83% by mass in the 2-chlorothionanone, and 0.17% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0140] The diluent accounts for 8.2% by mass in the UV-curable ink;

[0141] The rest is the same as in Example 1.

[0142] Example 5

[0143] The main difference between Example 5 and Example 1 is:

[0144] The initiator comprises 3% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 2% by mass in the UV-curable ink, 0.67% by mass in the 2-chlorothionanone, and 0.33% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.5.

[0145] The diluent accounts for 8.2% by mass in the UV-curable ink;

[0146] The rest is the same as in Example 1.

[0147] Example 6

[0148] The main difference between Example 6 and Example 1 is:

[0149] The initiator is composed of 2-hydroxy-2-methyl-1-phenylpropanone, isopropylthioxanthanone, and ethyl N,N-diphenylmethylformate; the mass percentage of 2-hydroxy-2-methyl-1-phenylpropanone in the UV-curable ink is 5%, the mass percentage of isopropylthioxanthanone in the UV-curable ink is 1%, the mass percentage of ethyl N,N-diphenylmethylformate in the UV-curable ink is 0.2%, and the mass ratio between isopropylthioxanthanone and ethyl N,N-diphenylmethylformate is 1:0.2.

[0150] The rest is the same as in Example 1.

[0151] Example 7

[0152] The main difference between Example 7 and Example 1 is:

[0153] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5% by mass in the UV-curable ink, 0.8% by mass in the 2-chlorothionanone, and 0.4% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.5.

[0154] The rest is the same as in Example 1.

[0155] Example 8

[0156] The main difference between Example 8 and Example 1 is:

[0157] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 3:1:0.5;

[0158] The rest is the same as in Example 1.

[0159] Example 9

[0160] The main difference between Example 9 and Example 1 is:

[0161] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 2% by mass, 3.5% by mass, and 0.7% by mass, with a mass ratio of 1:0.2 between 2-chlorothionanone and ethylenediamine.

[0162] The rest is the same as in Example 1.

[0163] Example 10

[0164] The main difference between Example 10 and Example 1 is:

[0165] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5.5% by mass in the UV-curable ink, 0.58% by mass in the 2-chlorothionanone, and 0.12% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0166] The rest is the same as in Example 1.

[0167] Example 11

[0168] The main difference between Example 11 and Example 1 is:

[0169] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5% by mass in the UV-curable ink, 1.09% by mass in the 2-chlorothionanone, and 0.11% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.1.

[0170] The rest is the same as in Example 1.

[0171] Example 12

[0172] The main difference between Example 12 and Example 1 is:

[0173] The initiator comprises 6.2% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 5% by mass in the UV-curable ink, 0.75% by mass in the 2-chlorothionanone, and 0.45% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.6.

[0174] The rest is the same as in Example 1.

[0175] Example 13

[0176] The main difference between Example 13 and Example 1 is:

[0177] The initiator comprises 8.5% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 6.85% by mass in the UV-curable ink, 1.375% by mass in the 2-chlorothionanone, and 0.275% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0178] The rest is the same as in Example 1.

[0179] Example 14

[0180] The main difference between Example 14 and Example 1 is:

[0181] The initiator comprises 2.5% by mass in the UV-curable ink and consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothionanone, and ethylenediamine. The initiator also comprises 2.0% by mass in the UV-curable ink, 0.42% by mass in the 2-chlorothionanone, and 0.08% by mass in the ethylenediamine. The mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0182] The rest is the same as in Example 1.

[0183] Example 15

[0184] The main difference between Example 15 and Example 1 is:

[0185] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 2:1:0.5;

[0186] The rest is the same as in Example 1.

[0187] Example 16

[0188] The main difference between Example 16 and Example 1 is:

[0189] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate, and trimethylolpropane triacrylate is 5:1:0.2.

[0190] The rest is the same as in Example 1.

[0191] Comparative Example 1

[0192] The main difference between Comparative Example 1 and Example 1 is:

[0193] The initiator has a mass percentage of 6.2% in the UV-curable ink and is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-chlorothionanone; the mass percentage of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide in the UV-curable ink is 5%, and the mass percentage of 2-chlorothionanone in the UV-curable ink is 1.2%.

[0194] The rest is the same as in Example 1.

[0195] Comparative Example 2

[0196] The main difference between Comparative Example 2 and Example 1 is:

[0197] The initiator has a mass percentage of 6.2% in the UV-curable ink and is composed of 2-chlorothionanone and ethylenediamine; the mass percentage of 2-chlorothionanone in the UV-curable ink is 5.17%, the mass percentage of ethylenediamine in the UV-curable ink is 1.03%, and the mass ratio of 2-chlorothionanone to ethylenediamine is 1:0.2.

[0198] The rest is the same as in Example 1.

[0199] Comparative Example 3

[0200] The main difference between Comparative Example 3 and Example 1 is:

[0201] The initiator has a mass percentage of 6.2% in the UV-curable ink and is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and ethylenediamine; the mass percentage of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide in the UV-curable ink is 5%, and the mass percentage of ethylenediamine in the UV-curable ink is 1.2%.

[0202] The rest is the same as in Example 1.

[0203] Test method:

[0204] The photocurable inks of Examples 1 to 16 and Comparative Examples 1 to 3 were sprayed onto aluminum sheets. An LED lamp was used as the light source, the wavelength of the ultraviolet light was 395nm, and the curing time was 8s to obtain an insulating coating with a thickness of 100μm.

[0205] (1) Cross-cut adhesion test

[0206] Following the method described in GB / T 9286-2021, the insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 were adhered to the surface of a 150×100mm aluminum plate placed on a horizontal, rigid plane. A cross-cutting tool was used to cut perpendicular to the sample, ensuring all cuts penetrated to the substrate surface. Subsequently, the same number of cuts were made in a direction intersecting the original cut lines at 90° angles, forming a grid. Afterward, a soft brush was used to sweep the surface several times, and transparent tape was applied over the grid, flattened, and then peeled off. The adhesion of the bonding insulating coatings was compared to the adhesion grading table. The test results are shown in Table 1.

[0207] (2) Shear strength test

[0208] The test was conducted according to the method in GB / T 7124-2008. The test results are shown in Table 1.

[0209] (3) Insulation resistance test

[0210] The insulation performance of the insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 was tested using an insulation withstand voltage tester at DC 1500V for 60 seconds. The insulation resistance was measured. The test results are shown in Table 1.

[0211] (4) High temperature resistance test

[0212] The insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 were subjected to high-temperature resistance tests: the test temperature was 130°C, and the test time was 48 hours. The samples were observed to detect any abnormalities such as shrinkage, peeling, or cracking. The test results are shown in Table 1.

[0213] (5) Withstand voltage test

[0214] The insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 were subjected to withstand voltage tests using an insulation withstand voltage tester. The test conditions were DC 4000V, the test time was 60s, and the leakage current was ≤0.1mA. The test results are shown in Table 1.

[0215] (6) Aging test

[0216] The insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 were subjected to voltage withstand tests and aging treatment using a constant temperature and humidity chamber. The aging treatment temperature was 85°C, the relative humidity was 85%, and the aging time was 2000 hours. After aging, the presence of cracks or peeling in the insulating coatings was observed. Simultaneously, the shear strength, adhesion, voltage withstand performance, and insulation resistance of the aged insulating coatings were tested. The test results are shown in Table 2.

[0217] (7) Electrolyte resistance test

[0218] The insulating coatings obtained in Examples 1 to 16 and Comparative Examples 1 to 3 were immersed in D73 electrolyte for 48 hours at 25°C. After drying, the voltage withstand performance, insulation performance, and adhesion of the insulating coatings were tested. The test results are shown in Table 3.

[0219] Table 1:

[0220]

[0221] Table 2:

[0222]

[0223] Table 3:

[0224]

[0225]

[0226] The test results from Examples 1 to 16 and Comparative Examples 1 to 3 show that the insulating coatings prepared in Examples 1 to 16, before aging treatment, all exhibited a cross-cut adhesion grade of 0 and a shear strength greater than or equal to 9.1 MPa. The insulating coatings of this application demonstrate good mechanical properties. This is because the photocurable ink includes acrylic resin, reactive monomers, and an initiator. The initiator promotes the polymerization reaction between the reactive monomers and the acrylic resin, thereby enabling the photocurable ink to cure. The initiators include deep-curing initiators, shallow-curing initiators, and amine co-initiators. The absorption wavelength of the deep-curing initiator is 300 nm-400 nm. The deep-curing initiator ensures that it can be effectively activated to generate free radicals even in deep regions, achieving deep curing. 。 The shallow curing initiator forms an excited state under light irradiation. The excited-state shallow curing initiator abstracts hydrogen atoms from the amine co-initiator to generate active free radicals and amine free radicals. The amine free radicals can react with oxygen to generate peroxide amines, which improves the oxygen inhibition problem and enhances the surface curing effect of the coating. When the light-cured ink is cured, the surface curing and the bottom curing can be achieved simultaneously, so that the shrinkage stress is evenly distributed, reducing local stress concentration, while ensuring uniform cross-linking of the insulating coating, improving the overall strength of the coating and thus improving the mechanical properties of the insulating coating.

[0227] A comparison of Examples 1-8, 9, and 10 shows that controlling the content of deep-curing initiators, shallow-curing initiators, and amine co-initiators within appropriate ranges can further improve the high-temperature resistance and aging performance of the insulating coating. This results in the insulating coating exhibiting good mechanical properties, insulation properties, voltage withstand properties, and high-temperature resistance both before and after aging treatment.

[0228] A comparison of Examples 1-8, 11, and 12 shows that controlling the mass ratio of the shallow curing initiator and the amine co-initiator within an appropriate range can further improve the high-temperature resistance, aging resistance, and electrolyte resistance of the insulating coating. This results in the insulating coating exhibiting good mechanical properties, insulation properties, voltage withstand properties, and high-temperature resistance before, after, and after electrolyte immersion treatment.

[0229] A comparison of Examples 1-8, 13, and 14 shows that controlling the mass percentage of the initiator in the UV-curable ink within an appropriate range can further improve the high-temperature resistance, aging resistance, and electrolyte resistance of the insulating coating. This results in the insulating coating exhibiting good mechanical properties, insulation properties, voltage resistance, and high-temperature resistance before, after, and after electrolyte immersion treatment.

[0230] A comparison of Examples 1-8, 15, and 16 shows that controlling the mass ratio of monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers within an appropriate range can further improve the high-temperature resistance, aging resistance, and electrolyte resistance of the insulating coating. This results in the insulating coating exhibiting good mechanical properties, insulation properties, voltage resistance, and high-temperature resistance before, after, and after electrolyte immersion treatment.

[0231] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A photocurable ink, characterized in that, include: Acrylic resin, reactive monomer, and initiator; The initiator includes a deep curing initiator, a shallow curing initiator, and an amine co-initiator. The absorption wavelength of the deep curing initiator is 300nm-400nm, and the shallow curing initiator includes thioxanthone compounds. The initiator in the photocurable ink has a mass percentage of 3%-8%; The sum of the masses of the shallow curing initiator and the amine co-initiator in the photocurable ink is 1%-3% by mass. The mass ratio between the shallow curing initiator and the amine co-initiator is 1:(0.2-0.5).

2. The photocurable ink according to claim 1, characterized in that, The initiator has an absorption wavelength of 365 nm or 395 nm; and / or The deep curing initiator in the photocurable ink has a mass percentage of 2%-5%; and / or The active monomer in the photocurable ink has a mass percentage of 25%-50%; and / or The acrylic resin in the UV-curable ink has a mass percentage of 40%-60%.

3. The photocurable ink according to claim 1 or 2, characterized in that, The deep curing initiator comprises at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolithyl)dicenzolide, bis2,6-difluoro-3-pyrrolithyldicenzolide, 2-hydroxy-2-methyl-1-phenylpropanone, and 1-hydroxycyclohexylphenyl ketone; and / or The thioxanthone compounds include at least one of 2-chlorothioxanthone, isopropylthioxanthone, and 2,4-diethylthioxanthone; and / or The amine co-initiator includes at least one of an active amine and a tertiary amine benzoate; and / or The acrylic resin includes polycarbonate-type polyurethane acrylate and linear aliphatic epoxy acrylate; and / or The active monomers include monofunctional acrylate monomers, difunctional acrylate monomers, and polyfunctional acrylate monomers, wherein the functionality of the polyfunctional acrylate monomers is greater than or equal to 3.

4. The photocurable ink according to claim 3, characterized in that, The active amine includes at least one selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophorone diamine, and 1,2-cyclohexanediamine; and / or The tertiary amine benzoate comprises at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethylformate, and 2-ethylhexyl N,N-dimethylbenzoate; and / or The monofunctional acrylate monomers include at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate; and / or The bifunctional acrylate monomers include at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; and / or The multifunctional acrylate monomers include at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tri(2-hydroxyethyl)isocyanurate triacrylate.

5. The photocurable ink according to claim 3, characterized in that, The mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer, and the polyfunctional acrylate monomer is (3-5):1:(0.3-0.5); and / or The polycarbonate-type polyurethane acrylate has a molecular weight of 500-1200; and / or The linear aliphatic epoxy acrylate has a molecular weight of 500-1200; and / or The mass ratio of the polycarbonate-type polyurethane acrylate to the linear aliphatic epoxy acrylate is (0.5-3):1; and / or The polycarbonate-type polyurethane acrylate has the general structural formula shown in formula (1): Structural formula (1); In structural formula (1), R1 is selected from a benzene ring or a C1-C6 substituted or unsubstituted alkyl group, and / or R2 is selected from a substituted or unsubstituted cyclohexyl group, and / or R3 and R4 are each independently selected from a C1-C6 substituted or unsubstituted alkyl group, and / or n is selected from an integer from 1 to 10, and / or m is selected from an integer from 1 to 10; and / or The linear aliphatic epoxy acrylate has the general structural formula shown in formula (2): Structural formula (2); In structural formula (2), R1 is selected from C1-C10 substituted or unsubstituted straight-chain or branched alkyl groups, and / or x is selected from integers from 1 to 6.

6. The photocurable ink according to claim 1 or 2, characterized in that, The photocurable ink also includes pigments, wetting agents, polymerization inhibitors, and / or diluents.

7. The photocurable ink according to claim 6, characterized in that, The wetting agent includes at least one of polyether-modified silicone and polyester-modified silicone; and / or The polymerization inhibitor includes at least one of hydroquinone and p-methoxyphenol; and / or The diluent includes at least one of isoborneol acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate.

8. The photocurable ink according to claim 6, characterized in that, The pigment in the photocurable ink has a mass percentage of 0.5-1%; and / or The wetting agent comprises 0.5-2.5% by mass in the UV-curable ink; and / or The polymerization inhibitor is present in the photocurable ink at a mass percentage of 0.1-0.5%; and / or The diluent in the UV-curable ink has a mass percentage of 4-5%; and / or The pigment has a particle size D50 ≤ 0.4 μm.

9. An insulating coating, characterized in that, The insulating coating is formed from the photocurable ink according to any one of claims 1-8.

10. A battery casing, characterized in that, include: Main body; An insulating coating is disposed on at least a portion of the outer surface of the main body, the insulating coating being formed from the photocurable ink according to any one of claims 1-8.

11. A method for preparing a battery casing, characterized in that, The method for preparing the battery casing includes: The main body provides the battery casing; Using the photocurable ink according to any one of claims 1-8 as raw material, an ink layer is formed by spraying onto at least a portion of the outer surface of the main body; The ink layer is cured by ultraviolet light to form an insulating coating, thus obtaining the battery casing.

12. The method for preparing the battery casing according to claim 11, characterized in that, The thickness of the ink layer is 50μm-150μm; and / or The ultraviolet light source includes an LED lamp, and / or the wavelength of the ultraviolet light is 365nm or 395nm, and / or the curing time is 1s-10s.

13. A battery, characterized in that, It includes the insulating coating as described in claim 9, or the battery casing as described in claim 10, or a battery casing prepared using the method described in claim 11 or 12.

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