UV-cured insulating tape for battery pack water-cooling plate and preparation method of UV-cured insulating tape

Abstract

The invention relates to a UV curing insulating tape for a battery pack water cooling plate and a preparation method thereof, and belongs to the technical field of insulating tapes. A pressure-sensitive adhesive layer of the UV-cured insulating tape comprises the following raw material components in parts by mass: 50-90 parts of an acrylate polymer, 50-85 parts of epoxy resin, 0.5-5 parts of a photoinitiator, 0.1-1 part of a sensitizer and 0.5-5 parts of a coupling agent; the acrylate polymer is prepared from a soft monomer, a hard monomer, a functional monomer and a crosslinking monomer according to a mass ratio of (80-90): (20-40): (35-45): (4-6) through free radical polymerization reaction. The UV-cured insulating adhesive tape has the characteristics of a pressure-sensitive adhesive tape at the initial stage, can still keep certain initial viscosity after being subjected to photocuring treatment, can be tightly attached by applying pressure under the condition of normal temperature, and has the shear strength of more than 8MPa after being completely cured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of insulating adhesive tape, and particularly relates to a UV-cured insulating adhesive tape for a battery pack water-cooling plate and a preparation method thereof. BACKGROUND

[0002] Under the background of rapid development of the new energy automobile industry, the safety and reliability of the battery pack as the core power component directly determine the running quality of the whole vehicle, and the battery water-cooling plate as the key component of the battery pack thermal management system needs to be treated by insulation packaging to ensure the stability of work and prevent safety hazards such as battery short circuit and liquid leakage. The PI adhesive tape is widely used in the packaging and fixing scene of the new energy automobile battery water-cooling plate due to its excellent insulation performance and temperature resistance, and provides reliable insulation protection and sealing protection for the water-cooling plate, which is of great significance to improve the overall safety performance of the battery pack.

[0003] At present, the mainstream technical scheme for the insulation covering of the new energy automobile battery water-cooling plate is the hot-pressing curing process, which has formed various specific structural forms through technical iteration. In the early stage, the flat hot-pressing scheme was mainly adopted, and subsequently, the flat hot-pressing + baking and hot-roller pasting + baking improved schemes were derived to improve the curing effect. With the increasing requirements of new energy automobiles on the structural strength and heat dissipation and uniform heating performance of the battery pack, the product structure design corresponding to the existing hot-pressing curing scheme becomes more and more complex, aiming to compensate for the performance short board through structural optimization, but the processing flow becomes complicated.

[0004] However, even after several improvements, the existing hot-pressing curing process still has some core defects that are difficult to overcome. Firstly, the heat dissipation effect is poor, and the heat transfer is uneven during the hot-pressing process, which is easy to cause dry burning phenomenon due to local high temperature, which not only damages the insulation and sealing performance of the adhesive tape, but also damages the water-cooling plate and the surrounding battery components, significantly reducing the running safety of the battery pack. Secondly, the production efficiency is low. The complex product structure design increases the processing procedures and prolongs the single processing cycle. At the same time, the hot-pressing curing and subsequent baking links themselves take a long time, which is difficult to adapt to the demand of the new energy automobile industry for large-scale production. Thirdly, the performance and efficiency cannot be considered simultaneously. In the process of pursuing the improvement of structural strength and the optimization of heat dissipation effect, the processing efficiency must be sacrificed. If the production efficiency is focused on, the structural strength of the battery water-cooling plate insulation covering will be insufficient, and the heat dissipation performance will be reduced, which cannot realize the synchronous optimization of the use performance and processing efficiency of the battery pack. The existence of the above problems makes the PI adhesive tape corresponding to the existing hot-pressing curing process difficult to meet the comprehensive demand of the current new energy automobile battery pack for high safety, high production efficiency and excellent thermal management performance, which restricts the high-quality development of the battery pack industry.

[0005] Therefore, developing a new type of insulating tape and its preparation method that can replace the traditional hot-press curing solution and take into account both processing efficiency and insulation sealing and heat uniformity has become an urgent technical problem to be solved in the research and development of key components for new energy vehicle battery packs. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides a UV-curable insulating tape for battery pack water-cooling plates and its preparation method. The UV-curable insulating tape for battery pack water-cooling plates initially has the characteristics of pressure-sensitive tape. After UV curing treatment, it can still maintain a certain initial tack. It can achieve tight bonding by applying pressure under room temperature conditions. After complete curing, its shear strength can reach more than 8 MPa.

[0007] The first objective of this invention is to provide a UV-curable insulating tape for a battery pack water-cooling plate, comprising a substrate layer, a release layer disposed on the substrate layer, and a pressure-sensitive adhesive layer disposed between the substrate layer and the release layer, wherein the raw material components and their weight parts of the pressure-sensitive adhesive layer are: 50-90 parts of acrylate polymer, 50-85 parts of epoxy resin, 0.5-5 parts of photoinitiator, 0.1-1 parts of sensitizer, and 0.5-5 parts of coupling agent; The acrylate polymer is prepared by free radical polymerization of soft monomers, hard monomers, functional monomers and crosslinking monomers in a mass ratio of (80-90):(20-40):(35-45):(4-6).

[0008] In one embodiment of the present invention, the soft monomer is selected from butyl acrylate, isooctyl acrylate, and tetrahydrofuran acrylate. The soft monomer provides initial tack and flexibility, ensuring that the tape can be pressure-bonded to the surface of the water-cooled plate at room temperature without heating, thus solving the problem of traditional hot-press tapes requiring high-temperature bonding. At the same time, the long-chain structure of the soft monomer can reduce the glass transition temperature, improve the tape's wetting ability on the irregular surface of the water-cooled plate, and avoid bonding gaps. And / or, the hard monomer is selected from methyl methacrylate, styrene, and isobornyl acrylate; by improving the structural strength and temperature resistance after curing, the hard monomer balances the "soft properties" brought by the soft monomer, avoiding tape deformation or insufficient temperature resistance after curing; at the same time, the rigid structure of the hard monomer can enhance the support of the polymer network and improve the shear strength. And / or, the functional monomer is selected from methacrylic acid, acrylic acid, hydroxyethyl acrylate, acryloylmorpholine, acrylamide, N-vinylcaprolactam, N-vinylpyrrolidone; by introducing active groups (carboxyl, hydroxyl, amide, etc.) through the functional monomer, the polar interaction between the adhesive layer and the substrate and the water-cooled plate is enhanced, thereby improving the peel strength.

[0009] And / or, the crosslinking monomer is glycidyl methacrylate; a three-dimensional crosslinking network is constructed through the crosslinking monomer: its epoxy groups can react with the carboxyl / hydroxyl groups of the functional monomer, and simultaneously synergistically crosslink with the epoxy groups of the epoxy resin, thus solving the problem of insufficient cohesive strength of simple acrylate polymers.

[0010] In one embodiment of the present invention, the epoxy resin is selected from one or more of the following: bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol S type epoxy resin, phenolic epoxy resin, hydrogenated phenolic epoxy resin, biphenyl type epoxy resin, hydrogenated biphenyl type epoxy resin, phenolic type epoxy resin, hydrogenated phenolic type epoxy resin, stilbene type epoxy resin, polyurethane modified epoxy resin, polyether modified epoxy resin, rubber modified epoxy resin, organosilicon modified epoxy resin, and dimer acid modified epoxy resin.

[0011] In one embodiment of the present invention, the photoinitiator is selected from one or more of diaryliodomonium salts, triarylthiomonium salts, alkylthiomonium salts, iron aromatic salts, and sulfonyloxy ketones.

[0012] In one embodiment of the present invention, the sensitizer is selected from 9,10-dibutoxyanthracene and / or 9,10-diethoxy-2-ethylanthracene; as anthracene derivatives, the sensitizer can absorb long-wavelength UV light and transfer energy to the photoinitiator, effectively improving the photoinitiation efficiency, thereby reducing the UV dose required for curing to reduce energy consumption, while avoiding damage to the substrate by short-wavelength UV light, and also promoting deep curing of the adhesive layer, improving reaction uniformity, and helping the adhesive layer to obtain high shear strength after complete curing.

[0013] In one embodiment of the present invention, the coupling agent is selected from one or more of silane coupling agents, phosphate coupling agents, and titanate coupling agents.

[0014] In one embodiment of the present invention, the substrate layer is a PI film; And / or, the release layer is a PET release film.

[0015] In one embodiment of the present invention, the thickness of the substrate layer is 10μm-200μm; And / or, the thickness of the pressure-sensitive adhesive layer is 10μm-200μm; And / or, the thickness of the release layer is 25μm-100μm.

[0016] A second objective of this invention is to provide a method for preparing the UV-curable insulating tape for a battery pack water-cooling plate, comprising the following steps: S1. Mix the acrylic polymer, epoxy resin, photoinitiator, sensitizer, coupling agent and solvent evenly to obtain a pressure-sensitive adhesive with a solid content of 30%-40%. S2. Apply the pressure-sensitive adhesive described in S1 to the surface of the substrate layer, dry it to form a pressure-sensitive adhesive layer, and then attach a release layer to the surface of the pressure-sensitive adhesive layer to obtain the UV-cured insulating tape for the battery pack water cooling plate.

[0017] In one embodiment of the present invention, in S1, the stirring speed is 400 rpm-800 rpm and the stirring time is 40 min-80 min.

[0018] The technical solution of the present invention has the following advantages compared with the prior art: (1) The UV-curable insulating tape of the present invention forms a core performance synergy through the compounding of acrylate polymer and epoxy resin. The acrylate polymer ensures the initial tack and flexibility of the adhesive layer. The specific ratio of epoxy resin avoids the defects of insufficient strength and poor temperature resistance after curing of single acrylate polymer, and overcomes the problems of insufficient flexibility and difficulty in room temperature bonding of pure epoxy resin. It achieves the synergistic effect of "initial tack meets bonding requirements and curing meets performance requirements".

[0019] (2) The UV-curable insulating tape of the present invention optimizes the curing efficiency and effect through the synergistic effect of photoinitiator and sensitizer. The photoinitiator can initiate polymerization and cross-linking reactions under UV light irradiation, while the sensitizer can absorb long-wavelength UV light and transfer energy to the photoinitiator, which not only improves the photoinitiation efficiency and reduces the UV dose and energy consumption required for curing, but also avoids damage to the PI substrate by short-wavelength UV light. At the same time, it promotes deep curing of the adhesive layer, ensures uniform and thorough cross-linking reaction, and guarantees the consistency of the overall performance of the adhesive layer. The coupling agent acts as an interface bridge to achieve multi-phase synergy. One end of it can combine with the active groups of acrylate polymer and epoxy resin in the pressure-sensitive adhesive layer, and the other end can react with hydroxyl groups and other groups on the substrate layer and the surface of the water-cooled plate. This effectively improves the interface bonding state between the adhesive layer and the substrate, and between the adhesive layer and the water-cooled plate, reduces interface defects, and synergistically improves the peel strength and shear strength of the adhesive layer, ensuring the stability and reliability of the insulating tape during long-term use. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0021] In this invention, unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] In this invention, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In this invention, unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0024] In this invention, unless otherwise stated, the term "parts" in the embodiments of this invention refers to "parts by mass".

[0025] In this invention, unless otherwise stated, the preparation of the acrylate polymer used in the embodiments of this invention includes the following steps: 65 parts of butyl acrylate, 20 parts of isooctyl acrylate, 30 parts of methyl methacrylate, 30 parts of acryloylmorpholine, 10 parts of hydroxyethyl acrylate, 5 parts of glycidyl methacrylate, and 150 parts of a mixed solvent (ethyl acetate to toluene in a mass ratio of 2:1) are weighed according to the following proportions. The above materials are then sequentially added to a four-necked reactor equipped with a stirring device, a reflux condenser, a thermometer, and a nitrogen inlet device. The stirring speed is set to 250 rpm, and high-temperature nitrogen is simultaneously introduced into the four-necked reactor. Pure nitrogen was bubbled to remove oxygen for 30 minutes to fully remove oxygen from the reactor space and reaction system. After the deoxygenation operation was completed, a slightly positive nitrogen protective atmosphere was maintained in the reactor. The system was heated to 70°C using an oil bath. After the system temperature stabilized, 0.03 parts of the initiator azobisisobutyronitrile (AIBN) were added. The system was kept at a constant temperature for 7 hours for polymerization. After the polymerization reaction was completed, the temperature was maintained and stirred for 30 minutes to ensure that the monomers in the system were fully converted. Then, heating and stirring were stopped, and the reaction system was allowed to cool naturally to room temperature to finally obtain the acrylate polymer.

[0026] In this invention, unless otherwise stated, the bisphenol A type epoxy resin used in the embodiments of this invention was purchased from Nan Ya and the model number is NPEL-128E.

[0027] In this invention, unless otherwise stated, the polyurethane-modified epoxy resin used in the embodiments of this invention is purchased from Arkema, model EPU603.

[0028] In this invention, unless otherwise stated, the iron aromatic salts IRGACURE 261 and IRGACURE 250 used in the embodiments of this invention were purchased from Hubei Kewode.

[0029] In this invention, unless otherwise stated, the silane coupling agent MP 200 used in the embodiments of this invention was purchased from Momentive.

[0030] In this invention, unless otherwise stated, the silane coupling agent KBM-403 used in the embodiments of this invention was purchased from Shin-Etsu Chemical Co., Ltd., Japan. Example 1

[0031] In this embodiment, the UV-curable insulating tape used for the water-cooling plate of the battery pack consists of a substrate layer, an adhesive layer, and a release layer from bottom to top; wherein, the substrate layer is a PI film with a thickness of 65μm; the pressure-sensitive adhesive layer has a thickness of 50μm; and the release layer is a transparent PET release film with a thickness of 25μm. The raw material components and their mass parts of the pressure-sensitive adhesive layer are as follows: 70 parts of acrylate polymer, 35 parts of bisphenol A type epoxy resin, 25 parts of polyurethane modified epoxy resin, 2.5 parts of iron aromatic salt IRGACURE 261, 0.5 parts of sensitizer 9,10-dibutoxyanthracene, and 0.5 parts of silane coupling agent MP 200.

[0032] Its preparation specifically includes the following steps: S1. Add acrylic polymer, epoxy resin, iron aromatic salt, sensitizer and silane coupling agent into a high-speed stirring tank containing ethyl acetate solvent according to the preset mass fraction. Control the stirring temperature at 45℃ and stir continuously at 600rpm for 60min. After filtering through a 200-mesh filter, a pressure-sensitive adhesive with a solid content of 35% and uniform and bubble-free is obtained. S2. Apply pressure-sensitive adhesive evenly to the surface of the substrate layer using a comma coating method. After drying in an oven to form a pressure-sensitive adhesive layer, immediately attach a release layer to the surface of the pressure-sensitive adhesive layer. During the attachment process, use a pressure roller to roll and remove bubbles. The pressure of the pressure roller is controlled at 0.4 MPa and the rolling speed is 0.8 m / min to obtain a UV-cured insulating tape for the battery pack water cooling plate. Example 2

[0033] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 35 parts bisphenol A type epoxy resin, 25 parts polyurethane modified epoxy resin, 2.5 parts iron aromatic salt IRGACURE 250, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 0.5 parts silane coupling agent MP 200. Example 3

[0034] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 60 parts bisphenol A type epoxy resin, 2.5 parts iron aromatic salt IRGACURE 250, 0.5 parts sensitizer 9,10-diethoxy-2-ethylanthracene, and 0.5 parts silane coupling agent KBM-403. Example 4

[0035] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 60 parts bisphenol A type epoxy resin, 2.5 parts iron aromatic salt IRGACURE 250, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 0.5 parts silane coupling agent KBM-403. Example 5

[0036] The basic difference from Example 1 lies in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 35 parts bisphenol A type epoxy resin, 25 parts polyurethane modified epoxy resin, 2.5 parts iron aromatic salt IRGACURE 261, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 1 part silane coupling agent MP 200. Example 6

[0037] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 35 parts bisphenol A type epoxy resin, 25 parts polyurethane modified epoxy resin, 2 parts iron aromatic salt IRGACURE 261, 0.5 parts sensitizer 9,10-diethoxy-2-ethylanthracene, and 1 part silane coupling agent MP 200. Comparative Example 1

[0038] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 35 parts bisphenol A type epoxy resin, 25 parts polyurethane modified epoxy resin, 10 parts iron aromatic salt IRGACURE 261, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 0.5 parts silane coupling agent MP 200. Comparative Example 2

[0039] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 2.5 parts iron aromatic salt IRGACURE 261, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 0.5 parts silane coupling agent MP 200. Comparative Example 3

[0040] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 35 parts of bisphenol A type epoxy resin, 25 parts of polyurethane modified epoxy resin, 2.5 parts of iron aromatic salt IRGACURE 261, 0.5 parts of sensitizer 9,10-dibutoxyanthracene, and 0.5 parts of silane coupling agent MP 200. Comparative Example 4

[0041] The difference from Example 1 is mainly in the raw material composition and mass fraction of the pressure-sensitive adhesive layer: 70 parts acrylate polymer, 35 parts bisphenol A type epoxy resin, 25 parts polyurethane modified epoxy resin, 2.5 parts iron aromatic salt IRGACURE 261, 0.5 parts sensitizer 9,10-dibutoxyanthracene, and 6 parts silane coupling agent MP 200. Test Example 1

[0042] The UV-cured insulating tapes prepared in Examples 1-6 and Comparative Examples 1-4 were subjected to the following tests: (1) Initial peel strength: In accordance with the requirements of GB / T 2792-2016 standard, take a standard sample of tape (25mm wide and 150mm long) that has not been cured by UV irradiation. After peeling off the release layer, quickly attach it to the surface of the aluminum plate at room temperature (23±2℃, relative humidity 50±5%). Roll it once with a pressure roller at 0.4MPa to ensure adhesion. Immediately install the sample on the peel strength tester, set the peel angle to 180°, the tensile speed to 300mm / min, start the tester, record the peel force data during the test, and take the average value in the test range as the initial peel strength. (2) Peel strength after curing: The tape to be bonded to the aluminum plate was placed in a UV curing device, and the irradiation energy was set to 2300mj / cm² and the wavelength to 365nm for UV irradiation treatment. After irradiation, the sample was placed in a room temperature environment (23±2℃, relative humidity 50±5%) for 72h to ensure that the tape was completely cured. Then the sample was installed on the peel strength tester, the peel angle was set to 180° and the tensile speed was 300mm / min. The tester was started, the peel force data during the test was recorded, and the average value in the test interval was taken as the peel strength after curing. (3) Cured shear strength: According to GB / T7124 standard, a fully cured tape-aluminum plate sample was selected and cut into a standard test piece with a width of 25mm and a bonding area of ​​25mm×12.5mm. The aluminum plate end and the free end of the tape of the test piece were fixed to the upper and lower clamps of the shear strength tester, ensuring that the clamps were firmly clamped and that the force direction of the test piece was parallel to the bonding surface. The tensile speed was set to 5mm / min, the tester was started to perform the shear test, the maximum shear force during the test was recorded, and the cured shear strength was calculated according to the formula "shear strength = maximum shear force / bonding area". Table 1 shows the relevant parameters of the material that were finally measured: Table 1

[0043] As shown in Table 1, the UV-cured insulating tapes in the embodiments all possess good initial peel strength, cured peel strength, and cured shear strength. The cured shear strength of all tapes reaches over 8 MPa, with some embodiments even exceeding 10 MPa, fully meeting the structural strength and bonding stability requirements of the battery pack water-cooling plate for the insulating tape. This is because the embodiments strictly adhere to a specific mass ratio of acrylate polymer and epoxy resin. Through their synergistic complementarity, the acrylate polymer ensures the initial tack and flexibility required for room-temperature bonding, while the epoxy resin enhances the structural strength and temperature resistance after curing. Simultaneously, the amounts of photoinitiator, sensitizer, and silane coupling agent are controlled within a reasonable range. These three agents respectively play roles in initiating crosslinking, improving curing efficiency, and enhancing interfacial bonding, forming a complete chain of performance optimization from initial tack to curing to interfacial bonding. This ensures that the adhesive layer can bond tightly at room temperature and form a stable three-dimensional crosslinked network after UV curing, thereby achieving a simultaneous improvement in peel strength and shear strength.

[0044] Comparing Example 1 and Comparative Example 1, it can be seen that the initial peel strength, post-curing peel strength, and post-curing shear strength of Comparative Example 1 are all significantly lower than those of Example 1, showing a substantial performance difference. This is because the amount of photoinitiator used in Comparative Example 1 is excessive. Excessive photoinitiator leads to an excessively rapid crosslinking reaction rate under UV irradiation, resulting in the rapid formation of a dense but uneven network structure within the adhesive layer. This not only impairs the adhesive layer's wetting and impregnation capabilities on the aluminum plate surface, preventing the formation of effective interfacial bonding, but also causes stress concentration within the adhesive layer, reducing cohesive strength and ultimately resulting in a comprehensive deterioration of peel and shear performance.

[0045] Comparing Example 1 and Comparative Example 2, it can be seen that the peel strength and shear strength of Comparative Example 2 after curing are much lower than those of Example 1, and there is no significant improvement in peel strength before and after curing. This is because Comparative Example 2 did not add epoxy resin components, and the system relied solely on the crosslinking monomer (glycidyl methacrylate) of the acrylate polymer itself for crosslinking, lacking the synergistic crosslinking effect between epoxy resin and acrylate polymer, making it difficult to form a high-density, high-strength three-dimensional crosslinked network. At the same time, the absence of epoxy resin also resulted in insufficient rigidity and cohesive strength of the adhesive layer after curing, making it unable to resist the external forces during peeling and shearing. Therefore, its performance is far inferior to that of Example 1, which contains both acrylate polymer and epoxy resin.

[0046] Comparing Example 1 and Comparative Example 3, it can be seen that Comparative Example 3 failed to form a film. This is because Comparative Example 3 did not add acrylate polymers and relied solely on epoxy resin as the main adhesive layer. Epoxy resin itself has extremely poor flexibility and lacks the initial tack required for room temperature bonding. During the coating process, it cannot form a continuous and uniform adhesive layer, and is prone to problems such as dripping and breakage, ultimately resulting in the inability to form a film.

[0047] Comparing Example 1 and Comparative Example 4, it can be seen that the initial peel strength, post-cured peel strength, and post-cured shear strength of Comparative Example 4 are all significantly lower than those of Example 1, indicating extremely poor performance. This is because the amount of coupling agent used in Comparative Example 4 is excessive. Excessive coupling agent will form an extra interfacial layer inside the adhesive layer. On the one hand, it hinders the cross-linking reaction between the acrylate polymer and the epoxy resin, resulting in insufficient cohesive strength of the adhesive layer; on the other hand, excessive coupling agent will be adsorbed at the interface between the adhesive layer and the aluminum plate, disrupting the polar interaction between the adhesive layer and the substrate, reducing the interfacial bonding force, and ultimately resulting in a significant decrease in peel and shear performance.

[0048] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A UV-curable insulating tape for a battery pack water-cooling plate, comprising a substrate layer, a release layer disposed on the substrate layer, and a pressure-sensitive adhesive layer disposed between the substrate layer and the release layer, characterized in that, The raw material components and their weight parts of the pressure-sensitive adhesive layer are as follows: 50-90 parts of acrylate polymer, 50-85 parts of epoxy resin, 0.5-5 parts of photoinitiator, 0.1-1 parts of sensitizer and 0.5-5 parts of coupling agent; The acrylate polymer is prepared by free radical polymerization of soft monomers, hard monomers, functional monomers and crosslinking monomers in a mass ratio of (80-90):(20-40):(35-45):(4-6).

2. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The soft monomer is selected from butyl acrylate, isooctyl acrylate, and tetrahydrofuran acrylate; And / or, the hard monomer is selected from methyl methacrylate, styrene, and isobornyl acrylate; And / or, the functional monomer is selected from methacrylic acid, acrylic acid, hydroxyethyl acrylate, acryloylmorpholine, acrylamide, N-vinylcaprolactam, and N-vinylpyrrolidone; And / or, the crosslinking monomer is glycidyl methacrylate.

3. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The epoxy resin is selected from one or more of the following: bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol S type epoxy resin, phenolic epoxy resin, hydrogenated phenolic epoxy resin, biphenyl type epoxy resin, hydrogenated biphenyl type epoxy resin, phenolic type epoxy resin, hydrogenated phenolic type epoxy resin, stilbene type epoxy resin, polyurethane modified epoxy resin, polyether modified epoxy resin, rubber modified epoxy resin, organosilicon modified epoxy resin, and dimer acid modified epoxy resin.

4. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The photoinitiator is selected from one or more of diaryliodomonium salts, triarylthiomonium salts, alkylthiomonium salts, iron aromatic salts, and sulfonyloxy ketones.

5. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The sensitizer is selected from 9,10-dibutoxyanthracene and / or 9,10-diethoxy-2-ethylanthracene.

6. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The coupling agent is selected from one or more of silane coupling agents, phosphate coupling agents, and titanate coupling agents.

7. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The substrate layer is a PI film; And / or, the release layer is a PET release film.

8. The UV-curable insulating tape for a battery pack water-cooling plate according to claim 1, characterized in that, The thickness of the substrate layer is 10μm-200μm; And / or, the thickness of the pressure-sensitive adhesive layer is 10μm-200μm; And / or, the thickness of the release layer is 25μm-100μm.

9. The method for preparing UV-curable insulating tape for a battery pack water-cooling plate as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix the acrylic polymer, epoxy resin, photoinitiator, sensitizer, coupling agent and solvent evenly to obtain a pressure-sensitive adhesive with a solid content of 30%-40%. S2. Apply the pressure-sensitive adhesive described in S1 to the surface of the substrate layer, dry it to form a pressure-sensitive adhesive layer, and then attach a release layer to the surface of the pressure-sensitive adhesive layer to obtain the UV-cured insulating tape for the battery pack water cooling plate.

10. The method for preparing UV-curable insulating tape for a battery pack water-cooling plate according to claim 9, characterized in that, In S1, the stirring speed is 400rpm-800rpm and the stirring time is 40min-80min.

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