Electrolyte-resistant acrylate pressure-sensitive adhesive tape and method of making same
By introducing fluorinated acrylates, cationic monomers, and a double crosslinking system, an organic-inorganic interpenetrating network was constructed, which solved the swelling and plasticization problems of acrylate pressure-sensitive adhesives in electrolytes, and achieved high-strength, stable, and durable tape performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN KAIDI ADHESIVE TECHNOLOGY CO LTD
- Filing Date
- 2026-02-09
- Publication Date
- 2026-06-16
AI Technical Summary
Traditional acrylic pressure-sensitive adhesives are prone to swelling and plasticizing in carbonate electrolytes, which leads to a decrease in adhesion performance and affects the safety and reliability of lithium-ion batteries.
By employing fluorinated acrylates, cationic functional monomers, and a double crosslinking system, combined with multifunctional siloxanes and γ-silane-modified halloysite nanotubes, an organic-inorganic interpenetrating network is constructed to enhance the cohesive strength and electrolyte resistance of the adhesive.
While maintaining good adhesion performance, it significantly inhibits swelling and plasticization, improves high-temperature stability and long-term reliability, and meets the insulation and fixing material requirements of power batteries and high-end consumer lithium batteries.
Smart Images
Figure SMS_1 
Figure SMS_2 
Figure SMS_3
Abstract
Description
Technical Field
[0001] This application relates to the field of acrylic pressure-sensitive tape technology, and more specifically, to an electrolyte-resistant acrylic pressure-sensitive tape and its preparation method. Background Technology
[0002] With the rapid development of the new energy vehicle industry and the continuous growth in demand for high-energy-density and high-safety lithium-ion batteries for consumer electronics, the manufacturing processes of power batteries and consumer lithium batteries have placed higher requirements on the performance of key auxiliary materials. In the structure of a lithium-ion battery, the cell, as the core energy unit, requires reliable fixation and electrical isolation through insulating tape in areas such as the positive and negative electrode tabs, winding or stacking termination points, to prevent safety hazards such as internal short circuits and thermal runaway during battery charge-discharge cycles, mechanical vibration, or high-temperature environments. Therefore, the tape used in these areas must not only possess excellent adhesive properties and mechanical strength but also be able to withstand the complex chemical environment inside the battery over a long period, especially exhibiting high stability against the erosion of organic electrolytes.
[0003] Currently, the industry widely uses PET-based tapes coated with acrylic pressure-sensitive adhesives as insulating and fixing materials for battery cells. However, conventional acrylic pressure-sensitive adhesives are typically copolymerized from soft monomers such as butyl acrylate and ethyl acrylate with a small amount of functional monomers such as acrylic acid. Their polymer network structure is prone to swelling, plasticization, and even partial dissolution when in contact with carbonate electrolytes commonly used in lithium-ion batteries, such as EC, DMC, and EMC. This swelling effect not only reduces the cohesive strength and peel tack of the adhesive layer, leading to problems such as tape delamination, displacement, or residue during use, but may also affect the battery's electrochemical performance due to the contamination of the battery cell's interior by adhesive degradation products.
[0004] More importantly, traditional acrylic pressure-sensitive adhesive formulations lack molecular structure design or cross-linking modification for electrolyte environments, and lack chemical inertness to lithium salts and their hydrolysis products in the electrolyte. This makes it difficult to meet the stringent reliability requirements of power batteries under high voltage, high temperature storage, and long cycle life. Therefore, there is an urgent need to develop a modified acrylic pressure-sensitive adhesive system with excellent electrolyte resistance and to composite it with a high-dimensional stability PET substrate to form a high-performance tape specifically for insulation and tab fixation of lithium-ion battery cells. This tape should maintain good initial tack and holding power while possessing comprehensive properties such as resistance to electrolyte swelling, corrosion resistance, no residue, and color stability, thereby ensuring the safety and consistency of the battery throughout its entire life cycle. Summary of the Invention
[0005] To address the problem of acrylate pressure-sensitive adhesives easily swelling and plasticizing in carbonate electrolytes, this application provides an electrolyte-resistant acrylate pressure-sensitive tape and its preparation method.
[0006] In a first aspect, this application provides an electrolyte-resistant acrylic pressure-sensitive tape, employing the following technical solution: An electrolyte-resistant acrylic pressure-sensitive tape includes a release layer, a substrate layer, and an adhesive layer, wherein the adhesive layer is prepared from the following raw materials in parts by weight: 100 parts of adhesive Hardener 0.25-0.75 parts Other adjuvants: 0-1 part The adhesive is prepared by the following method: 1) According to the weight parts, add 50-75 parts of soft monomer, 8-15 parts of hard monomer, 6-14 parts of functional monomer, 5-12 parts of fluorinated acrylate, 1-3 parts of initiator solution and 100-150 parts of organic solvent to the reactor, and react at 65-70℃ under nitrogen protection to obtain prepolymer solution. 2) Disperse 3-8 parts of halloysite nanotubes treated with γ-methacryloxypropyltrimethoxysilane in 10-15 parts of organic solvent, sonicate, then slowly add prepolymer solution, stir for 1-2 hours, then cool to 45-50℃, add 2-4 parts of multifunctional siloxane crosslinking agent and 0.1-0.3 parts of initiator solution to react, add 0.5-1.5 parts of isocyanate crosslinking agent and 0.05-0.15 parts of catalyst, stir evenly, and cure at 25-35℃ to obtain adhesive; The functional monomer is composed of hydroxyethyl acrylate, glycidyl acrylate and ionic monomers; The ionic monomers are methacryloyloxyethyltrimethylammonium chloride or methacryloyloxyethyldimethylbenzylammonium chloride; The multifunctional siloxane crosslinking agent is a polysiloxane containing acryloyloxy group and has a number average molecular weight of 800-2000.
[0007] By adopting the above technical solution, the acrylic pressure-sensitive tape produced has high adhesion reliability, electrolyte resistance, excellent thermochemical stability and no residue characteristics, which fully meets the stringent requirements of power batteries and high-end consumer lithium batteries for insulating fixing materials.
[0008] In this application, soft monomers provide flexibility and initial tack, while hard monomers enhance cohesive strength. The balanced ratio of these two ensures that the adhesive layer possesses both tackiness and mechanical stability. Among the functional monomers, hydroxyethyl acrylate provides hydroxyl groups, which react with the subsequently added isocyanate crosslinking agent to form stable urethane bonds; the epoxy groups of glycidyl acrylate enhance adhesion to metal tabs and substrates; the introduction of cationic monomers not only improves the electrostatic adsorption of the adhesive layer to polar interfaces, but more importantly, its quaternary ammonium salt structure exhibits excellent chemical inertness in the electrolyte environment, avoiding the drawback of traditional acrylic acid where carboxyl groups readily react with HF to generate water and accelerate aging.
[0009] Fluorinated acrylates, due to their high CF bond energy and low surface energy, can reduce the affinity of the adhesive layer for carbonate electrolytes, effectively inhibiting swelling and plasticization. Multifunctional siloxane crosslinking agents participate in free radical copolymerization, constructing an organic-inorganic hybrid network that retains the flexibility of acrylates while introducing highly thermally stable Si-O-Si segments, improving high-temperature tack and creep resistance. They form an interpenetrating network with the isocyanate crosslinking system, significantly enhancing cohesion, heat resistance, and long-term tack, effectively preventing debonding or displacement under long-term cycling, high-temperature storage, or mechanical vibration. Halloysite nanotubes, modified with γ-methacryloyloxypropyltrimethoxysilane, have polymerizable groups grafted onto their surface, covalently bonding with the adhesive matrix. This improves dispersibility and provides both nano-reinforcement and electrolyte penetration barrier properties.
[0010] Through the synergistic effect of its components, the tape maintains excellent initial tack and peel strength while possessing outstanding resistance to electrolyte swelling, high-temperature stability, no residue, and color stability, fully meeting the stringent reliability requirements of power batteries under high voltage, high temperature storage, and long cycle life.
[0011] Preferably, in the functional monomers, the mass ratio of hydroxyethyl acrylate, glycidyl acrylate and ionic monomers is (3-6):(2-5):1.
[0012] By adopting the above technical solution and optimizing the dosage of the three components, hydroxyethyl acrylate provides sufficient hydroxyl groups to support the subsequent efficient reaction with the isocyanate crosslinking agent, constructing a highly cohesive urethane network. Simultaneously, an appropriate amount of glycidyl acrylate enhances the chemical anchoring effect of the adhesive layer on the aluminum / copper tabs and substrate, improving interfacial adhesion durability. An appropriate amount of ionic monomer imparts chemical inertness and electrostatic adsorption capacity to the adhesive layer for electrolyte components. The optimal balance between crosslinking density, interfacial bonding strength, and electrolyte resistance is achieved through a specific ratio of these three components, ensuring that the tape maintains its performance—residue-free, non-detaching, and stable—even under high temperature, high voltage, and long-term electrolyte immersion conditions.
[0013] Preferably, the soft monomer is composed of isooctyl acrylate and butyl acrylate in a weight ratio of (2.5-4):1.
[0014] By adopting the above technical solutions and optimizing the amount and type of soft monomers, the flexibility, weather resistance, and electrolyte resistance of the adhesive can be improved. Isooctyl acrylate has longer branched alkyl side chains, giving the polymer a lower glass transition temperature and excellent low-temperature flexibility and anti-plasticization ability. Its swelling rate in carbonate electrolytes is significantly lower than that of butyl acrylate. Butyl acrylate, on the other hand, provides good initial tack and wettability to the substrate. By compounding the two in a ratio of (2.5-4):1, the dimensional stability and anti-swelling advantages of isooctyl acrylate in the electrolyte environment are fully utilized, while retaining the rapid wetting and adhesion ability of butyl acrylate to the tabs and PET substrates, avoiding the decline in adhesive performance due to excessive use of highly hydrophobic monomers. This specific ratio ensures the tape's softness and adhesion while effectively suppressing plasticization and cohesive attenuation caused by electrolyte penetration, thereby improving the reliability of the battery under long-term cycling and high-temperature storage.
[0015] Preferably, the fluorinated acrylate is one or more selected from hexafluorobutyl acrylate, trifluoroethyl methacrylate, tridecylfluorooctyl methacrylate, or perfluoroalkyl ethyl acrylate.
[0016] By adopting the above technical solutions and optimizing the types of fluorinated acrylates, the affinity of adhesives for carbonate electrolytes can be further reduced, effectively inhibiting swelling and plasticization; at the same time, the hydrophobicity, chemical inertness and thermal stability of the adhesive layer are improved, avoiding the corrosion of lithium salts and their hydrolysis products in the electrolyte, thereby significantly enhancing the long-term durability and reliability of the tape in the harsh environment of the battery while maintaining the bonding performance.
[0017] Preferably, the hard monomer is methyl methacrylate.
[0018] By adopting the above technical solutions, optimizing the types of hard monomers can effectively improve the cohesive strength, modulus and creep resistance of the adhesive, and synergistically balance the viscoelasticity of the adhesive layer with soft monomers; at the same time, methyl methacrylate has a stable structure and moderate polarity, which helps to enhance the adhesion to PET substrates, and it is not easy to swell or degrade in the electrolyte environment, thereby ensuring the dimensional stability and bonding reliability of the tape under high temperature and long-term use.
[0019] Preferably, the halloysite nanotubes have a diameter of 30-70 nm and a length of 200-800 nm.
[0020] By adopting the above technical solution and optimizing the diameter and length of halloysite nanotubes, they can be effectively dispersed in the adhesive matrix to form a dense physical barrier, delaying electrolyte penetration; at the same time, they provide excellent reinforcing effect, improve the mechanical strength of the adhesive layer, ensure the tape is flexible and adherent, and take into account barrier properties, reinforcement and processing stability.
[0021] Preferably, the concentration of the initiator solution is 0.5-1.5 wt% and the solvent is ethyl acetate, and the initiator is selected from azobisisobutyronitrile or benzoyl peroxide.
[0022] By adopting the above technical solution, the free radical polymerization rate can be effectively controlled, avoiding excessively fast reaction that leads to an overly wide molecular weight distribution or gelation. This ensures that soft / hard / functional and fluorinated monomers are fully copolymerized to form a prepolymer with uniform structure and controllable crosslinking, laying the foundation for the final adhesive layer's electrolyte resistance, cohesive strength, and process stability.
[0023] Preferably, the isocyanate crosslinking agent is hexamethylene diisocyanate trimer or isophorone diisocyanate trimer.
[0024] By adopting the above technical solution, the multifunctional structure of both can fully react with the hydroxyl groups of hydroxyethyl acrylate in the adhesive to form a high-density, thermally stable urethane crosslinking network, which further enhances the cohesive strength of the adhesive layer and its resistance to electrolyte swelling, ensuring that the tape remains reliable, residue-free, and does not age under long-term high temperature or electrolyte immersion environments.
[0025] Preferably, the catalyst is dibutyltin dilaurate or stannous octoate.
[0026] By adopting the above technical solution, the reaction between isocyanate groups and hydroxyl groups is accelerated, promoting the efficient formation of urethane crosslinking network during the curing stage; at the same time, the reaction is controllable, avoiding rapid polymerization, and ensuring that the adhesive layer structure is uniform and dense, thereby improving electrolyte resistance, cohesive strength and long-term bonding stability.
[0027] Preferably, the other additives are color pastes.
[0028] The above technical solution is used to adjust the color of the tape to meet the needs of different customers.
[0029] Secondly, this application provides a method for preparing an electrolyte-resistant acrylic pressure-sensitive tape, using the following technical solution: A method for preparing an electrolyte-resistant acrylic pressure-sensitive tape includes the following preparation steps: 1) Mix the adhesive, curing agent and other additives to obtain an adhesive slurry; 2) The substrate and release film are laminated together, and the side of the substrate away from the release film is subjected to corona treatment. Then, the adhesive slurry is coated on the surface of the substrate and dried to obtain an electrolyte-resistant acrylic pressure-sensitive tape.
[0030] By adopting the above technical solutions, corona treatment effectively improves the surface energy of the substrate, enhances its interfacial bonding with the adhesive layer, and prevents interlayer delamination in high-temperature or electrolyte environments; the use of a pre-cured adhesive system in conjunction with subsequent curing ensures the full development of the cross-linked network, while avoiding poor gelation or leveling during coating; the entire process is simple, controllable, compatible with existing coating production lines, and requires no high-temperature or complex equipment.
[0031] Preferably, the release layer is a 0.1-1μm PET release film, the substrate layer is a 19-38μm biaxially oriented PET film, and the dry adhesive layer has a thickness of 6-30μm.
[0032] By adopting the above technical solution, the release layer uses an ultra-thin 0.1-1μm PET release film to ensure easy peeling and no contamination of the adhesive surface; the substrate layer uses a 19-38μm biaxially oriented PET film, which has high dimensional stability, excellent mechanical strength and heat resistance, and is suitable for battery winding / stacking processes; the adhesive layer's dry adhesive thickness is controlled at 6-30μm, balancing sufficient adhesive strength and flexible fit, avoiding excessive thickness that could lead to internal stress or electrolyte penetration channels. The synergistic optimization of these three elements allows the tape to maintain its thinness and high transparency while possessing excellent electrical insulation, electrolyte resistance and long-term reliability, meeting the stringent requirements of high-energy-density lithium-ion batteries for the insulation of the tab fixing and termination parts.
[0033] In summary, this application has the following beneficial effects: 1. Improve electrolyte resistance and long-term reliability: By introducing fluorinated acrylate, cationic functional monomers and a double crosslinking system, the swelling, plasticization and chemical degradation of the adhesive layer in carbonate electrolytes are effectively inhibited, avoiding the aging problem caused by the reaction of carboxyl groups and HF in traditional acrylate adhesives, and ensuring that the battery does not delaminate or leave any residue under high temperature, high voltage and long cycle conditions.
[0034] 2. Constructing a high-strength, high-stability composite crosslinking network: Multifunctional siloxanes and isocyanates are synergistically crosslinked, and combined with the covalent dispersion of γ-silane-modified halloysite nanotubes to form an organic-inorganic interpenetrating network structure, which greatly enhances the cohesive strength, creep resistance and thermochemical stability of the adhesive, while maintaining good flexibility and adhesion.
[0035] 3. Achieve excellent interfacial adhesion: The epoxy and hydroxyl groups in the functional monomers synergistically enhance the chemical anchoring effect on the metal tabs and PET substrate. Combined with corona treatment and optimized coating process, the tape has both high initial tack and high peel strength, fully meeting the insulation and fixing material requirements of power batteries and high-end consumer lithium batteries. Detailed Implementation Preparation Example
[0036] Preparation Example 1 An adhesive is prepared by the following method: 1) Add 500g of soft monomer, 80g of hard monomer (methyl methacrylate), 60g of functional monomer, 50g of fluorinated acrylate (hexafluorobutyl acrylate), 10g of initiator solution and 1000g of organic solvent (ethyl acetate) to the reactor, and heat to 65℃ under nitrogen protection to react and obtain a prepolymer solution. 2) 30g of halloysite nanotubes treated with γ-methacryloxypropyltrimethoxysilane were dispersed in 100g of organic solvent (ethyl acetate), sonicated, and then slowly added to the prepolymer solution. After stirring for 1 hour, the temperature was lowered to 45°C, and 20g of multifunctional siloxane crosslinking agent and 1g of initiator solution were added to react. 5g of isocyanate crosslinking agent (hexamethylene diisocyanate trimer) and 0.5g of catalyst (dibutyltin dilaurate) were added. After stirring evenly, the mixture was cured at 25°C to obtain the adhesive. The soft monomer is composed of isooctyl acrylate and butyl acrylate in a weight ratio of 2.5:1; The functional monomer is composed of hydroxyethyl acrylate, glycidyl acrylate and ionic monomer in a weight ratio of 3:2:1; The ionic monomer is methacryloyloxyethyltrimethylammonium chloride; The multifunctional siloxane crosslinking agent is tris(methacryloyloxypropyl)-terminated polydimethylsiloxane with a number average molecular weight of 800. The initiator solution has a concentration of 0.5 wt% and uses ethyl acetate as the solvent. The initiator is selected from azobisisobutyronitrile. Halloysite nanotubes have a diameter of 300 nm and a length of 200 nm.
[0037] The difference between Preparation Examples 2-3 and Preparation Example 1 lies in the types, amounts, and parameters of the raw materials used to prepare the adhesives. The specific differences are shown in Table 1. Table 1. Types, amounts, and parameters of raw materials used in the preparation of adhesives.
[0038] In Preparation Example 2, the ionic monomer was methacryloyloxyethyl dimethyl benzyl ammonium chloride; The initiator solution has a concentration of 1 wt% and uses ethyl acetate as the solvent. The initiator is selected from benzoyl peroxide.
[0039] In Preparation Example 3, the ionic monomer was methacryloyloxyethyl dimethyl benzyl ammonium chloride; The initiator solution has a concentration of 1.5 wt% and uses ethyl acetate as the solvent. The initiator is selected from azobisisobutyronitrile.
[0040] Preparation Example 4 An adhesive, the difference between this preparation example and preparation example 1 is that the mass ratio of hydroxyethyl acrylate, glycidyl acrylate and ionic monomer is 1:2:1.
[0041] Preparation Example 5 An adhesive, the difference between this preparation example and preparation example 1 is that the soft monomer is composed of isooctyl acrylate and butyl acrylate in a weight ratio of 1:1.
[0042] Preparation Example 6 An adhesive, the difference between this preparation example and preparation example 1 is that the soft monomer is isooctyl acrylate.
[0043] Preparation Example 7 An adhesive, the difference between this preparation example and preparation example 1 is that the multifunctional siloxane crosslinking agent is bis(3-methacryloyloxypropyl)tetramethyldisiloxane.
[0044] Preparation of comparative examples Preparation of Comparative Example 1 An adhesive, the difference between this comparative preparation and Preparation Example 1 is that butyl acrylate is used instead of an equal mass of butyl acrylate.
[0045] Preparation of Comparative Example 2 An adhesive, the difference between this comparative preparation and Preparation Example 1 is that the functional monomer is composed of hydroxyethyl acrylate and glycidyl acrylate in a weight ratio of 3:2.
[0046] Preparation of Comparative Example 3 An adhesive, the difference between this comparative preparation and Preparation Example 1 is that no isocyanate crosslinking agent is added.
[0047] Preparation of Comparative Example 4 An adhesive, the difference between this comparative example and preparation example 1 is that the multifunctional siloxane crosslinking agent is replaced with KH-570.
[0048] Preparation of Comparative Example 5 An adhesive, the difference between this comparative example and preparation example 1 is that nano-silica is used instead of halloysite nanotubes whose surfaces are treated with γ-methacryloyloxypropyltrimethoxysilane.
[0049] Example The curing agent used is CYMEL325 cyanoacrylate resin produced by Zhanxin Company.
[0050] The colorant used is ML-green colorant from Huizhou Yikai Packaging Materials Co., Ltd.
[0051] Example 1 An electrolyte-resistant acrylic pressure-sensitive tape is prepared by the following method: 1) Mix 1000g of adhesive, 2.5g of curing agent and 0g of other additives (color paste) from Preparation Example 1 to obtain adhesive slurry; 2) The substrate and release film are laminated, and the side of the substrate away from the release film is subjected to corona treatment. Then, the adhesive paste is coated on the surface of the substrate and dried to obtain an electrolyte-resistant acrylic pressure-sensitive tape. The release layer is a 0.1μm PET release film, the substrate layer is a 19μm biaxially oriented PET film, and the dry adhesive layer has a thickness of 6μm.
[0052] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of raw materials used to prepare the electrolyte-resistant acrylic pressure-sensitive tape. Specific differences are shown in Table 2. Table 2. Raw material types, dosages, and parameters for preparing electrolyte-resistant acrylic pressure-sensitive tapes.
[0053] The difference between Examples 4-14 and Example 1 lies in the source of the adhesive, as shown in Table 3: Table 3 Source of adhesives in Examples 1 and 4-14 Detection method / testing method
[0054] 180° peel force: Refer to GB / T 2792-2014; Initial adhesion of steel balls: Refer to GB / T 4852-2002; High temperature resistance test: Apply the electrolyte-resistant acrylic pressure-sensitive tape to the steel plate and roll it back and forth 3 times. After standing for 2 hours, place it in an environment of 110℃ for 30 minutes, take it out, cool it, tear it off, and observe whether there is any adhesive residue.
[0055] Electrolyte resistance test: Apply the electrolyte-resistant acrylic pressure-sensitive tape to the aluminum foil, then immerse it completely in the electrolyte and place it at 85℃ for 24 hours. Remove it, wipe it dry, peel the tape off the aluminum foil, and observe whether there is any residue or corrosion in the adhesive layer of the tape. The electrolyte was purchased from Guangrui Company in Fushan Industrial Zone, Zhuhai City, and its model number is GR-8166.
[0056] Swelling performance test: Several 25×25mm acrylic pressure-sensitive tape samples were cut from electrolyte-resistant acrylic tape. The thickness A1 of the tape samples was measured using a digital high-precision vernier caliper. The cut samples were placed in clean, covered glass petri dishes and then completely immersed in the electrolyte. They were left to stand at 85℃ for 7 days. After that, the samples were removed, flattened in a special glass dish, and the thickness A2 of the tape samples was measured using a digital high-precision vernier caliper. The swelling rate was calculated as follows: Swelling rate = (A2-A1) / A1*100%. The experimental data are shown in Table 4. Table 4 Experimental data of Examples 1-14
[0057] As can be seen from the above experimental data, the adhesive prepared by the specific preparation method of this application for the preparation of acrylic pressure-sensitive tape can greatly improve the adhesive performance and corrosion resistance of acrylic pressure-sensitive tape, while reducing its swelling rate.
[0058] Comparing Example 1 with Examples 10-14, it can be seen that Example 1 maintains moderate peel strength and good initial tack while having a swelling rate of only 3.2%, and is completely free of residue and corrosion after high temperature and electrolyte immersion. In contrast, Examples 10-14 show a significantly increased swelling rate and exhibit problems such as residue, decreased adhesion, and even corrosion. This indicates that the combination of fluorinated acrylate, ionic monomers, isocyanate crosslinking agents, multifunctional siloxane crosslinking agents, and halloysite nanotubes with γ-methacryloyloxypropyltrimethoxysilane surface treatment in this application is the key factor in achieving the comprehensive performance of acrylate pressure-sensitive tape, including anti-swelling, high adhesion, high temperature resistance, and corrosion resistance.
[0059] Comparing Example 1 with Example 6, it is shown that the hydroxyl groups provided by hydroxyethyl acrylate are key to forming a high-cohesion urethane network with the isocyanate crosslinking agent. Insufficient hydroxyl content will directly weaken the crosslinking density and interfacial stability, thereby affecting the adhesive strength and durability of the tape.
[0060] Comparing Examples 1 and 7-8, it is shown that butyl acrylate provides the necessary substrate wettability and initial tack, while isooctyl acrylate imparts low swelling and flexibility. The two work synergistically in a specific ratio (2.5–4:1) to balance the adhesion and electrolyte stability of acrylic pressure-sensitive tape.
[0061] Comparing Examples 1 and 9, it is shown that polysiloxanes containing acryloyloxy groups can effectively participate in free radical copolymerization and construct a high-density, high-stability organic-inorganic interpenetrating network, thereby improving the cohesive strength and electrolyte penetration resistance of the adhesive layer.
[0062] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. An electrolyte-resistant acrylic pressure-sensitive tape, comprising a release layer, a substrate layer, and an adhesive layer, characterized in that, The adhesive layer is prepared from the following raw materials in parts by weight: 100 parts of adhesive Hardener 0.25-0.75 parts Other adjuvants: 0-1 part The adhesive is prepared by the following method: 1) According to the weight parts, add 50-75 parts of soft monomer, 8-15 parts of hard monomer, 6-14 parts of functional monomer, 5-12 parts of fluorinated acrylate, 1-3 parts of initiator solution and 100-150 parts of organic solvent to the reactor, and react at 65-70℃ under nitrogen protection to obtain prepolymer solution. 2) Disperse 3-8 parts of halloysite nanotubes treated with γ-methacryloxypropyltrimethoxysilane in 10-15 parts of organic solvent, sonicate, then slowly add prepolymer solution, stir for 1-2 hours, then cool to 45-50℃, add 2-4 parts of multifunctional siloxane crosslinking agent and 0.1-0.3 parts of initiator solution to react, add 0.5-1.5 parts of isocyanate crosslinking agent and 0.05-0.15 parts of catalyst, stir evenly, and cure at 25-35℃ to obtain adhesive; The functional monomer is composed of hydroxyethyl acrylate, glycidyl acrylate and ionic monomers; The ionic monomers are methacryloyloxyethyltrimethylammonium chloride or methacryloyloxyethyldimethylbenzylammonium chloride; The multifunctional siloxane crosslinking agent is a polysiloxane containing acryloyloxy group and has a number average molecular weight of 800-2000.
2. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: In the functional monomers, the mass ratio of hydroxyethyl acrylate, glycidyl acrylate and ionic monomers is (3-6):(2-5):
1.
3. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The soft monomer is composed of isooctyl acrylate and butyl acrylate in a weight ratio of (2.5-4):
1.
4. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The fluorinated acrylate is one or more of hexafluorobutyl acrylate, trifluoroethyl methacrylate, tridecylfluorooctyl methacrylate, or perfluoroalkyl ethyl acrylate.
5. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The hard monomer is methyl methacrylate.
6. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The initiator solution has a concentration of 0.5-1.5 wt% and is in ethyl acetate as the solvent. The initiator is selected from azobisisobutyronitrile or benzoyl peroxide.
7. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The isocyanate crosslinking agent is hexamethylene diisocyanate trimer or isophorone diisocyanate trimer.
8. The electrolyte-resistant acrylic pressure-sensitive tape according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate or stannous octoate.
9. A method for preparing an electrolyte-resistant acrylic pressure-sensitive tape as described in any one of claims 1-8, characterized in that, The preparation steps include the following: 1) Mix the adhesive, curing agent and other additives to obtain an adhesive slurry; 2) The substrate and release film are laminated together, and the side of the substrate away from the release film is subjected to corona treatment. Then, the adhesive slurry is coated on the surface of the substrate and dried to obtain an electrolyte-resistant acrylic pressure-sensitive tape.
10. The method for preparing the electrolyte-resistant acrylic pressure-sensitive tape according to claim 9, characterized in that: The release layer is a 0.1-1μm PET release film, the substrate layer is a 19-38μm biaxially oriented PET film, and the dry adhesive layer has a thickness of 6-30μm.