Preparation method of UV ink-jet ink for new energy battery and UV resin synthesis method of UV ink-jet ink

Abstract

The invention relates to the technical field of new energy battery materials, and discloses a preparation method of UV ink-jet ink for a new energy battery and a UV resin synthesis method of the UV ink-jet ink. Comprising the following components: 15%-25% of self-developed polyurethane acrylate UV resin, 60%-75% of a reactive diluent, 1%-5% of a photoinitiator, 1%-5% of nano UV color paste, 0.05%-1% of an auxiliary agent, 0.1%-1% of fumed silica and 0.5%-2% of an adhesion promoter. The preparation method comprises the following steps: S1, adding the self-developed polyurethane acrylate UV resin, the reactive diluent, the photoinitiator and the auxiliary agent into a stirrer together, and stirring in a dark environment at the temperature of not more than 40 DEG C until the materials are uniformly mixed to form a transparent base material. By optimizing the raw material ratio and the preparation process of the UV ink-jet ink and combining with the specific synthesis path of the self-developed polyurethane acrylate UV resin, the problems that a traditional PET blue film process is poor in cohesiveness and low in breakdown voltage resistance and a UV spraying process wastes materials and pollutes the environment are solved, and accurate printing of the ink on the surface of a new energy battery cell can be achieved.

Description

Technical Field

[0001] This invention relates to the field of new energy battery materials technology, specifically to a method for preparing UV inkjet ink for new energy batteries and a method for synthesizing UV resin. Background Technology

[0002] Currently, in the field of new energy battery cell production, the protection process for their aluminum casings mainly relies on two technologies: traditional PET blue film technology and UV spraying technology. The traditional PET blue film technology uses PET film as the substrate, forming a pressure-sensitive single-sided adhesive tape by coating the substrate surface with blue adhesive, and then applying it to the surface of the battery cell's aluminum casing for protection. However, the blue film used in this process has inherent defects in adhesion and durability, easily leading to problems such as damage, blistering, and edge curling in practical applications. Furthermore, the complex production process results in low efficiency and poor product quality consistency. More importantly, the blue film has weak breakdown voltage resistance, posing a high risk of leakage and making it unsuitable for the high voltage requirements of 800V and above in new energy vehicles. The demand for fast charging is driving the industry's development. To address the shortcomings of traditional PET blue film coating, UV spraying technology has gradually emerged as an alternative. For example, BMW has built a production line for spraying coatings on its power battery cells. This process involves directly spraying blue UV coating onto the aluminum casing of the battery cell, which is then cured by UV light to form a protective coating. While this process is superior to PET blue film in terms of voltage resistance and durability, a significant amount of UV coating fails to adhere to the cell surface, resulting in waste. This not only increases the cost of recycling but also pollutes the environment due to the unrecovered coating. Furthermore, the spraying process struggles to achieve high-precision control of the coating, failing to meet the protection requirements of complex areas on the battery cell casing.

[0003] In summary, existing aluminum casing protection processes for new energy battery cells have significant shortcomings in terms of performance adaptability, environmental friendliness, cost control, and precision control. Therefore, those skilled in the art propose a method for preparing UV inkjet ink for new energy batteries and a method for synthesizing UV resin to address these problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing UV inkjet ink for new energy batteries and a method for synthesizing UV resin, which solves the technical problems of poor adhesion and breakdown voltage of the PET blue film process used for aluminum casing protection of existing new energy battery cells, as well as the waste of materials and environmental pollution in the UV spraying process.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing UV inkjet ink for new energy batteries, wherein the raw materials for preparing the UV inkjet ink, by mass percentage, include the following components: 15%–25% self-developed polyurethane acrylate UV resin, 60%–75% reactive diluent, 1%–5% photoinitiator, 1%–5% nano UV color paste, 0.05%–1% additives, 0.1%–1% fumed silica, and 0.5%–2% adhesion promoter; and the preparation method includes the following steps:

[0006] S1. Add the self-developed polyurethane acrylate UV resin, reactive diluent, photoinitiator and additives to a stirrer, and stir until uniformly mixed in an environment protected from light and at a temperature not exceeding 40°C to form a transparent base material.

[0007] S2. Add fumed silica and nano UV color paste to the transparent base material obtained in step S1, keep the temperature not exceeding 40°C, stir at high speed for 1-2 hours, and then grind the material with a grinder until the particle size is less than or equal to 500nm, so that the fumed silica and nano UV color paste are evenly dispersed in the transparent base material, and finally obtain UV inkjet ink for new energy batteries.

[0008] Through the above technical solution, by rationally selecting raw material components and optimizing the preparation process, on the one hand, the synergistic effect of self-developed polyurethane acrylate UV resin and other raw materials is utilized, combined with operations such as light-proof low-temperature stirring and precise grinding to control particle size, to ensure that the components of the ink are uniformly dispersed and that the ink has stable performance suitable for UV inkjet printing, enabling precise coating of the surface of new energy battery cells; on the other hand, this preparation method can effectively avoid the defects of traditional processes, and the ink can form a high-performance coating after curing, providing reliable protection for new energy battery cells, while taking into account the environmental friendliness and operability of the process, helping to improve the production efficiency and quality stability of the protective coating for new energy battery cells.

[0009] Preferably, the reactive diluent is selected from at least three of the following: isobornyl acrylate, isobornyl methacrylate, tetrahydrofuran acrylate, tetrahydrofuran acrylate ethoxylate, cyclotrimethylolpropane methyl acetal acrylate, 2-phenoxyethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, triethylolpropane triacrylate triethoxylate, and trimethylolpropane triacrylate propionate.

[0010] The above technical solution utilizes at least three specific types of reactive diluents, such as isobornyl acrylate and isobornyl methacrylate, which can synergize well with other raw materials such as self-developed polyurethane acrylate UV resin and photoinitiator to adjust the viscosity of the ink system to meet the smoothness requirements of UV inkjet printing. Furthermore, these diluents can participate in the curing reaction under LED light irradiation, improving the ink curing efficiency and the mechanical strength and adhesion stability of the cured coating. Simultaneously, by optimizing the overall performance of the ink through multi-component combination, the coating can meet the environmental resistance and electrolyte resistance requirements for the protection of new energy battery cells, thus facilitating the reliable application of inks in the field of new energy batteries.

[0011] Preferably, the photoinitiator is selected from at least two of 1-hydroxycyclohexyl benzophenone, methyl benzoylformate, benzophenone, 4,6-trimethylbenzoylphosphine oxide, 2-benzyl-2-dimethylamino-4'-morpholinophenylbutanone, and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, and the photoinitiator can trigger the curing reaction under LED light irradiation at wavelengths of 365 nm and 395 nm.

[0012] The above technical solution selects at least two specific photoinitiators, such as 1-hydroxycyclohexyl benzophenone and methyl benzoate. These photoinitiators can trigger the curing reaction under LED light irradiation at wavelengths of 365nm and 395nm. Through the synergistic effect of the multi-component photoinitiators, the ink can be quickly and fully cured under LED light irradiation, meeting the curing efficiency requirements of UV inkjet printing process for new energy battery cells. It can also ensure the stability of the curing reaction, helping to form a uniform coating, thereby improving the protective effect of the coating on new energy battery cells and adapting to the efficient and reliable process requirements in the production of new energy batteries.

[0013] Preferably, the adhesion promoter is selected from at least one of phosphate ester acrylate and silane coupling agent; wherein the phosphate ester acrylate is selected from at least one of Toyo PM-2 and Sartoma CD9051, and the silane coupling agent is KH570.

[0014] By using the above technical solution, at least one of phosphate ester acrylate and silane coupling agent (KH570) is selected as an adhesion promoter, which can effectively enhance the bonding strength between the UV inkjet ink coating after curing and the substrate such as the aluminum shell of new energy battery cells, and avoid problems such as peeling and cracking of the coating during use. At the same time, it can form good compatibility with other raw materials in the ink system, further ensuring the overall stability of the coating performance and meeting the requirements of new energy battery cell protective coating for adhesion reliability.

[0015] Preferably, the additives include only defoamers and leveling agents, and the mass percentage of defoamers and leveling agents in the UV inkjet ink is 0.05% to 0.2%. The resulting UV inkjet ink has a viscosity of 20-30 mPa·s at 25°C, a shear force of ≥11 MPa after curing, and a leakage current ≤30 μA under a DC4000V, 60S withstand voltage test.

[0016] The above technical solution limits the additives to include only defoamers and leveling agents. This not only eliminates air bubbles generated during ink preparation by defoamers and optimizes the smoothness of the ink coating by leveling agents, avoiding the impact of air bubbles or uneven coating on ink performance and the quality of subsequent cured coatings, but also enables the prepared UV inkjet ink to have viscosity characteristics suitable for UV inkjet printing. At the same time, it ensures that the cured coating has shear strength and insulation properties that meet the requirements of new energy batteries, ensuring that the coating has reliable structural stability and electrical safety during battery use.

[0017] A method for synthesizing UV resin for new energy batteries, wherein the raw materials for synthesizing the UV resin include isocyanate, polyester polyol, hydroxyl-containing acrylate, catalyst and polymerization inhibitor, and the synthesis method includes the following steps:

[0018] A1. Add isocyanate, catalyst, and polymerization inhibitor to the reactor in sequence, turn on the stirring and heat to 40-50℃;

[0019] A2. Slowly add hydroxyl-containing acrylate to the reactor of step A1, controlling the adding time to be 0.8-1.2h. After the addition is complete, keep the reaction at 50-60℃ for 2.5-3.5h.

[0020] A3. Add polyester polyol to the reactor from step A2, heat to 70-80℃, and continue the reaction at this temperature for 2.5-3.5 hours;

[0021] A4. Add a small amount of hydroxyl-containing acrylate to the reactor of step A3, and continue the reaction for 0.4 to 0.6 hours until the NCO% content in the material is ≤0.1%. Stop the reaction and discharge the material to obtain polyurethane acrylate UV resin.

[0022] The above technical solution, through a synthesis process involving staged temperature control, precise dropwise addition, and endpoint control of NCO% content, ensures the formation of structurally regular polyurethane acrylate UV resin, avoiding disordered chain extension of polymer segments. It also guarantees stable resin quality and compatibility with the subsequent compounding requirements of UV inkjet inks. This provides core raw material support for the preparation of UV inkjet inks for new energy batteries with low viscosity and high curing performance, thereby helping to improve the overall performance of inks and cured coatings in the protection of new energy battery cells.

[0023] Preferably, the isocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate, and the molar ratio of the isocyanate to the hydroxyl-containing acrylate is 1:(0.95-1.05).

[0024] By employing the above technical solution, at least one specific isocyanate, such as toluene diisocyanate or diphenylmethane diisocyanate, and controlling its specific molar ratio with hydroxyl-containing acrylates, the precise reaction between the isocyanate and the hydroxyl-containing acrylates ensures the formation of a polyurethane acrylate UV resin with a regular structure and stable performance, avoiding resin performance defects caused by improper raw material ratios. Furthermore, the synthesized resin is adapted to the compounding requirements of subsequent UV inkjet inks, providing reliable core raw material support for the preparation of UV inkjet inks for new energy batteries with low viscosity, high curing efficiency, and excellent coating performance.

[0025] Preferably, the polyester polyol is selected from at least one of polycarbonate-type polyester polyol, polycaprolactone-type polyester polyol, and polyadipate-type polyester polyol, and the hydroxyl value of the polyester polyol is 100-120 mgKOH / g, and the molar ratio of polyester polyol to isocyanate is (0.45-0.55):1.

[0026] By employing the above technical solution, at least one of polycarbonate-type, polycaprolactone-type, and polyadipate-type polyester polyols is selected, and their specific hydroxyl values ​​and molar ratios with isocyanates are controlled. This approach not only facilitates the generation of polyurethane acrylate UV resins with regular structures and suitable viscosity through the compatibility reaction between polyester polyols and isocyanates, thus avoiding the impact of improper polyester polyol performance or proportions on resin quality, but also ensures that the synthesized resin exhibits good synergy with UV inkjet inks and other raw materials. This provides a key raw material guarantee for the subsequent preparation of UV inkjet inks for new energy batteries that possess low viscosity, high printability, and excellent coating performance after curing.

[0027] This invention provides a method for preparing UV inkjet ink for new energy batteries and a method for synthesizing UV resin. It has the following beneficial effects:

[0028] 1. This invention optimizes the raw material ratio and preparation process of UV inkjet inks, and combines it with the specific synthesis path of self-developed polyurethane acrylate UV resin. This solves the problems of poor adhesion, low breakdown voltage, material waste, and environmental pollution in traditional PET blue film processes, as well as UV spraying processes. It also enables precise printing of inks on the surface of new energy battery cells. After curing with 365nm and 395nm wavelength LED light, the coating has excellent adhesion, impact resistance, and electrolyte resistance, making it suitable for the high-voltage fast charging requirements of new energy vehicles, while taking into account both environmental protection and product reliability.

[0029] 2. This invention uses a synthesis method that involves single-sided end-capped isocyanate with hydroxyl-containing acrylates and then linking it with polyester polyols. This effectively reduces disordered chain extension of polymer segments, lowers resin viscosity, and thus ensures that the compounded UV inkjet ink maintains low viscosity characteristics, ensuring smooth inkjet printing. At the same time, by rationally combining raw materials such as reactive diluents and photoinitiators, the ink curing efficiency and coating mechanical strength are improved, meeting the high precision and high production efficiency requirements of UV inkjet printing for new energy battery cells.

[0030] 3. The UV inkjet ink preparation method of the present invention has a simple and controllable process. By stirring in the dark and at low temperature and precisely grinding to control the particle size, the ink components are uniformly dispersed. The raw materials used contain only defoamers and leveling agents, avoiding interference from excess components on the ink performance. At the same time, the UV resin synthesis process ensures stable resin quality by controlling the reaction temperature, dropping time and NCO% content endpoint. Attached Figure Description

[0031] Figure 1 This is the overall flowchart of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Please see the appendix Figure 1 This embodiment provides a method for preparing UV inkjet ink for new energy batteries and synthesizing a dedicated polyurethane acrylate UV resin. The specific steps are as follows:

[0035] Synthesis of polyurethane acrylate UV resin: According to the reaction ratio, isophorone diisocyanate (IPDI) and p-hydroxyanisole (total mass of 450 ppm of IPDI) were added sequentially to a reactor equipped with a stirring and temperature control device. The stirring was turned on and the temperature was raised to 45°C. Then, hydroxyethyl acrylate (HEA) was slowly added dropwise to the reactor, with the addition time controlled at 1 hour. After the addition was completed, the temperature was raised to 55°C and the reaction was maintained at this temperature for 3 hours. Next, polycarbonate-type polyester polyol (hydroxyl value of 110 mg KOH / g) was added to the reactor, and the temperature was raised to 75°C. The reaction was continued at this temperature for 3 hours. Finally, a small amount of HEA was added, and the reaction was continued for 0.5 hours. During this period, the NCO% content in the material was confirmed to drop below 0.1% by detection. The reaction was then stopped and the material was discharged to obtain the desired polyurethane acrylate UV resin.

[0036] Preparation of UV inkjet ink for new energy batteries: Weigh out the following by mass percentage: 20% of the synthesized polyurethane acrylate UV resin, 30% of reactive diluent (isoborneol acrylate, 30% tetrahydrofuran acrylate, 10.5% triethylolpropane triacrylate), 3% of photoinitiator (1-hydroxycyclohexyl benzophenone, 1% 4,6-trimethylbenzoylphosphine oxide, 0.5% bis(2,4,6-trimethylphenylyl)phosphine oxide), 0.1% of additives (defoamer, 0.1% leveling agent), 1.5% of adhesion promoter (Toyo PM-2 from Japan), and 1.5% of hydrophobic nano-sized gas... The mixture consists of 0.3% fumed silica (Degussa R-202) and 3% nano UV color paste. First, polyurethane acrylate UV resin, reactive diluent, photoinitiator, and additives are added to a stirrer and stirred until homogeneous in a light-protected environment at 38°C to form a transparent base material. Then, fumed silica and nano UV color paste are added to the transparent base material, maintaining a temperature not exceeding 40°C. The mixture is first stirred at high speed for 1.5 hours, and then ground to a particle size of 450 nm using a grinder. This ensures that the fumed silica and nano UV color paste are uniformly dispersed in the transparent base material, ultimately producing UV inkjet ink for new energy batteries.

[0037] Example 2

[0038] This embodiment provides a method for preparing UV inkjet ink for new energy batteries and synthesizing a dedicated polyurethane acrylate UV resin. The specific steps are as follows:

[0039] Synthesis of polyurethane acrylate UV resin: Toluene diisocyanate (TDI) and tert-butylcatechol (total mass of 480 ppm of TDI) were added sequentially to a reactor, stirred, and heated to 42°C. Hydroxyethyl methacrylate (HEMA) was slowly added dropwise to the reactor over a period of 1.1 h. After the addition was complete, the temperature was adjusted to 52°C and the reaction was maintained for 3.2 h. Then, polycaprolactone-type polyester polyol (hydroxyl value of 105 mg KOH / g) was added to the reactor, the temperature was raised to 72°C, and the reaction was continued for 3.3 h. Finally, a small amount of HEMA was added, and the reaction was continued for another 0.45 h. The reaction was stopped and the product was discharged after the NCO% content in the material was detected to be ≤0.1%, thus obtaining polyurethane acrylate UV resin.

[0040] Preparation of UV inkjet ink for new energy batteries: By mass percentage, take 22% of the above-synthesized polyurethane acrylate UV resin, 30% of reactive diluent (isoborneol methacrylate, 30% cyclotrimethylolpropane methyl acetal acrylate, and 9% triethylolpropane triacrylate), 2% of photoinitiator (2% 1-hydroxycyclohexyl benzophenone, 1% 4,6-trimethylbenzoylphosphine oxide, 0.5% benzophenone, and 0.5% 2-benzyl-2-dimethylamino-4'-morpholinophenylbutanone), 0.1% of additives (0.1% defoamer and 0.1% leveling agent), and 0.1% of adhesion promoter (Sartoma CD). The mixture consists of 90511.5% hydrophobic nano-sized fumed silica (Degussa R-974), 0.3% nano-UV color paste, and 3% polyurethane acrylate UV resin, reactive diluent, photoinitiator, and additives. The mixture is stirred in a stirrer at 35°C in the dark until homogeneous, forming a transparent base material. Fumed silica and nano-UV color paste are added to the transparent base material, and the temperature is kept below 40°C. The mixture is first stirred at high speed for 1.2 hours, and then ground in a grinder until the particle size is 480 nm to ensure uniform dispersion of fumed silica and nano-UV color paste, thus obtaining UV inkjet ink for new energy batteries.

[0041] Example 3

[0042] This embodiment provides a method for preparing UV inkjet ink for new energy batteries and synthesizing a dedicated polyurethane acrylate UV resin. The specific steps are as follows:

[0043] Synthesis of polyurethane acrylate UV resin: Hexamethylene diisocyanate (HDI) and hydroquinone (total mass of 420 ppm of HDI) were added to a reactor, stirred, and heated to 48°C; hydroxypropyl acrylate (HPA) was slowly added dropwise over 0.9 h, and after the addition was complete, the reaction was maintained at 58°C for 2.8 h; polyadipate-type polyester polyol (hydroxyl value of 115 mg KOH / g) was added to the reactor, the temperature was raised to 78°C, and the reaction was carried out for 2.7 h; a small amount of HPA was added, and the reaction was continued for 0.55 h. When the NCO% content in the material dropped below 0.1%, the reaction was stopped and the material was discharged to obtain polyurethane acrylate UV resin.

[0044] Preparation of UV inkjet ink for new energy batteries: Weigh out the following by weight percentage: 20% of the synthesized polyurethane acrylate UV resin, 35% of reactive diluent (isoborneol methacrylate, 35% tetrahydrofuran acrylate), 3.5% of photoinitiator (methyl benzoylformate, 1.5% bis(2,4,6-trimethylphenylyl)phosphine oxide), 0.1% of additives (defoamer, 0.1% leveling agent), 1.5% of adhesion promoter (KH570), and 1.5% of hydrophobic nano-sized fumed silica (Degussa R-202). 0.3% of polyurethane acrylate UV resin, 3% of nano UV color paste; add polyurethane acrylate UV resin, reactive diluent, photoinitiator and additives to a stirrer, stir until uniformly mixed in a light-proof environment at 36°C to form a transparent base material; add fumed silica and nano UV color paste to the transparent base material, keep the temperature not exceeding 40°C, stir at high speed for 1.8h, and then grind the material to a particle size of 420nm through a grinder, so that the fumed silica and nano UV color paste are uniformly dispersed in the transparent base material, and finally obtain UV inkjet ink for new energy batteries.

[0045] The test results are shown in Table 1 below:

[0046] Table 1 (Performance Test Results of UV Inkjet Inks for New Energy Batteries (Examples 1-3))

[0047]

[0048]

[0049] Conclusion: The UV inkjet inks for new energy batteries prepared by this invention (Examples 1-3) exhibit excellent comprehensive performance and strong stability, specifically: Firstly, the ink viscosity at 25℃ is suitable for UV inkjet printing requirements, ensuring smooth operation of the printhead; secondly, the adhesion of the cured coatings all reach GB / T9286-2021 standard level 0, with good shear strength performance, and outstanding resistance to falling ball impact (1KG, 50cm) and 90-degree bending resistance, without cracking or paint peeling, indicating that the coating is firmly bonded to the aluminum shell of the new energy battery cell, and its mechanical strength is sufficient to withstand the external forces during cell production and use; thirdly, in terms of electrical performance and environmental resistance... The coating exhibits low leakage current under DC4000V and 60S withstand voltage tests, meeting the insulation requirements of high-voltage applications in new energy batteries. Furthermore, after 500 hours of neutral salt spray, 500 cycles of high and low temperature shock (-40~85℃), and 1000 hours of double 85 aging tests, no discoloration, cracking, peeling, or blistering was observed. In electrolyte resistance tests, only slight gloss loss and good adhesion were observed, indicating that the coating effectively resists the complex environment encountered during the use of new energy batteries (such as electrolyte corrosion, drastic temperature and humidity changes, and salt spray erosion). It can replace the protective layer formed by traditional PET blue film and UV spraying processes, providing long-term stable protection for new energy battery cells.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing UV inkjet ink for new energy batteries, characterized in that, The raw materials for preparing this UV inkjet ink, by weight percentage, include the following components: 15%–25% self-developed polyurethane acrylate UV resin, 60%–75% reactive diluent, 1%–5% photoinitiator, 1%–5% nano UV color paste, 0.05%–1% additives, 0.1%–1% fumed silica, and 0.5%–2% adhesion promoter; and the preparation method includes the following steps: S1. Add the self-developed polyurethane acrylate UV resin, reactive diluent, photoinitiator and additives to a stirrer, and stir until uniformly mixed in an environment protected from light and at a temperature not exceeding 40°C to form a transparent base material. S2. Add fumed silica and nano UV color paste to the transparent base material obtained in step S1, keep the temperature not exceeding 40°C, stir at high speed for 1-2 hours, and then grind the material with a grinder until the particle size is less than or equal to 500nm, so that the fumed silica and nano UV color paste are evenly dispersed in the transparent base material, and finally obtain UV inkjet ink for new energy batteries.

2. The method for preparing UV inkjet ink for new energy batteries according to claim 1, characterized in that, The reactive diluent is selected from at least three of the following: isobornyl acrylate, isobornyl methacrylate, tetrahydrofuran acrylate, tetrahydrofuran acrylate ethoxylate, cyclotrimethylolpropane methyl acetal acrylate, 2-phenoxyethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, triethylolpropane triacrylate triethoxylate, and trimethylolpropane triacrylate propionate.

3. The method for preparing UV inkjet ink for new energy batteries according to claim 1, characterized in that, The photoinitiator is selected from at least two of 1-hydroxycyclohexyl benzophenone, methyl benzoylformate, benzophenone, 4,6-trimethylbenzoylphosphine oxide, 2-benzyl-2-dimethylamino-4'-morpholinophenylbutanone, and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, and the photoinitiator can trigger the curing reaction under LED light irradiation at wavelengths of 365 nm and 395 nm.

4. The method for preparing UV inkjet ink for new energy batteries according to claim 1, characterized in that, The adhesion promoter is selected from at least one of phosphate ester acrylate and silane coupling agent; wherein the phosphate ester acrylate is selected from at least one of Toyo PM-2 and Sartoma CD9051, and the silane coupling agent is KH570.

5. The method for preparing UV inkjet ink for new energy batteries according to claim 1, characterized in that, The additives include only defoamers and leveling agents, and the mass ratio of defoamers and leveling agents in UV inkjet ink is 0.05% to 0.2%. The resulting UV inkjet ink has a viscosity of 20-30 mPa·s at 25°C, and the shear force of its cured coating is ≥11 MPa. Under the withstand voltage test conditions of DC4000V and 60S, the leakage current is ≤30μA.

6. A method for synthesizing UV resin for new energy batteries, comprising a method for preparing UV inkjet ink for new energy batteries according to any one of claims 1-5, characterized in that, The raw materials for synthesizing this UV resin include isocyanate, polyester polyol, hydroxyl-containing acrylate, catalyst, and polymerization inhibitor, and the synthesis method includes the following steps: A1. Add isocyanate, catalyst, and polymerization inhibitor to the reactor in sequence, turn on the stirring and heat to 40-50℃; A2. Slowly add hydroxyl-containing acrylate to the reactor of step A1, controlling the adding time to be 0.8-1.2h. After the addition is complete, keep the reaction at 50-60℃ for 2.5-3.5h. A3. Add polyester polyol to the reactor from step A2, heat to 70-80℃, and continue the reaction at this temperature for 2.5-3.5 hours; A4. Add a small amount of hydroxyl-containing acrylate to the reactor of step A3, and continue the reaction for 0.4 to 0.6 hours until the NCO% content in the material is ≤0.1%. Stop the reaction and discharge the material to obtain polyurethane acrylate UV resin.

7. The method for synthesizing UV resin for new energy batteries according to claim 6, characterized in that, The isocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate, and the molar ratio of the isocyanate to the hydroxyl-containing acrylate is 1:(0.95-1.05).

8. The method for synthesizing UV resin for new energy batteries according to claim 6, characterized in that, The polyester polyol is selected from at least one of polycarbonate-type polyester polyol, polycaprolactone-type polyester polyol, and polyadipate-type polyester polyol, and the hydroxyl value of the polyester polyol is 100-120 mgKOH / g, and the molar ratio of polyester polyol to isocyanate is (0.45-0.55):1.

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