Low-voltage fast response electrolytic viscose tape and preparation method thereof

Abstract

The application discloses a low-voltage fast-response electrolytic adhesive tape, which comprises, from top to bottom, a first release film layer, a first electrolytic adhesive layer, a conductive substrate layer, a second electrolytic adhesive layer and a second release film layer; the first electrolytic adhesive layer and the second electrolytic adhesive layer comprise an acrylic polymer copolymerized from acrylic ester monomers and a reactive conductive salt; the acrylic ester monomers comprise acrylic ester soft monomers, acrylic ester hard monomers and acrylic ester functional polar monomers; and the reactive conductive salt is firmly bonded to the main chain of the acrylic polymer in the form of a covalent bond in the copolymerization process. The application further discloses a preparation method of the low-voltage fast-response electrolytic adhesive tape. The application has the advantages of fast peeling and fast response.

Description

Technical Field

[0001] This invention relates to electrolytic adhesive tape, and more specifically to a low-voltage fast-response electrolytic adhesive tape and its preparation method. Background Technology

[0002] Electrolytic adhesive tape (also known as "electro-assisted adhesive tape" or "electro-peeling tape") typically consists of an adhesive layer and a conductive layer. Its core technology is based on the electric field-induced ion migration effect. By applying a voltage to both sides of the adhesive layer, the conductive materials (cations and anions) in the adhesive layer undergo an electrolytic reaction: cations migrate to the cathode and undergo reduction, while anions migrate to the anode and undergo oxidation. This reaction effectively weakens the adhesive interface, thus significantly reducing the tape's adhesive force in a short time. Electrolytic adhesive tape exhibits strong adhesion and holding power in the un-energized state, making it suitable for applications requiring strong bonding; however, after energization, the adhesive force rapidly weakens, allowing the tape to be easily peeled off the adhered object, achieving a "controlled bonding" function. Due to its balance of reversible disassembly and environmental protection requirements, electrolytic adhesive tape shows broad application prospects in consumer electronics, new energy vehicles, solar panels, and semiconductor packaging, especially in scenarios such as smartphone battery replacement, automotive electronic module repair, and high-end equipment recycling.

[0003] In practical applications of electrolytic adhesive tape, low-voltage triggering and rapid response have become key directions for technological development. From an application perspective, low-voltage operation (typically below 12V) significantly improves safety, avoiding the risks of short circuits or thermal runaway that can be caused by high voltage, especially in battery-related applications. Rapid response (referring to debonding within seconds) directly relates to repair efficiency and user experience, and has significant value in industry.

[0004] The current market expectation for electrolytic adhesive tape has risen from basic "peelability" to a comprehensive requirement of "efficiency, safety, and convenience." Taking smartphone battery replacement as an example, ideally, the battery should be peeled off without damage within 10 seconds at a safe voltage of around 9V. However, most existing technologies still struggle to balance low-voltage triggering and rapid response, often requiring higher voltages (e.g., 22V) or longer times (e.g., 30 seconds) for effective peeling. This technological bottleneck severely limits the application of electrolytic adhesive tape in a wider range of fields.

[0005] Commonly used electrolytic adhesive tapes are physically blended types, but high ion migration resistance is an inherent drawback of these tapes. Physically blended electrolytic adhesive tapes are made by physically blending solid conductive salts (such as ammonium salts, halide carbonates, and alkali metal-containing organic sulfonates) with polar, inert solvents (such as dimethyl carbonate and propylene carbonate) into the adhesive matrix. Because the conductive salts and adhesive matrix are only physically mixed, they fail to form effective molecular-level bonds, hindering ion migration within the colloid and resulting in high migration resistance. To achieve the necessary ion migration for debonding, a high voltage (typically above 20V) and a long time (over 30 seconds) are often required. Simple physical blending also leads to easy electrolyte precipitation, especially under high temperature and humidity conditions, where ionic liquids easily migrate, affecting not only the long-term stability of the tape but also potentially causing electrochemical corrosion. Studies have shown that after exposure to high temperature and humidity conditions, the adhesive strength of this type of tape before energization is significantly reduced, and its recovery is also poor. In addition, tapes prepared by physical blending have serious problems with electrolyte precipitation, which easily contaminates the object after being energized, and are difficult to reuse. They are usually reused only a limited number of times, and their performance deteriorates significantly after 3-5 uses.

[0006] While traditional copolymer-type electrolytic adhesive tapes improve ion stability to some extent by copolymerizing reactive conductive salts with polymer monomers, they still suffer from problems such as high trigger voltage and insufficient response speed. The root cause lies in the fact that the copolymer molecular structure design does not adequately consider ion migration efficiency. Existing functional copolymers often focus on adhesive performance and stability, neglecting the construction of ion migration channels. For example, some technical solutions use functional copolymers containing monomers such as 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 1,3-bis(epoxyethylenemethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione. While these bulky groups enhance cohesive strength, they also increase resistance to ion migration. Furthermore, the ion transport mechanism in traditional copolymers is inefficient; the directional migration of anions and cations under the influence of an electric field is not rapid enough, resulting in a slow interfacial debonding process and making it difficult to achieve a second-level rapid response.

[0007] Clearly, existing copolymer-type electrolytic adhesive tapes neglect the construction of ion migration channels, increasing the resistance to ion migration, resulting in inefficient ion transport mechanisms. The directional migration of anions and cations under the influence of an electric field is not rapid enough, leading to a slow interfacial debonding process and difficulty in achieving a fast response. Summary of the Invention

[0008] To address the technical problems of existing copolymer-type electrolytic adhesive tapes that neglect the construction of ion migration channels, increasing the resistance to ion migration, resulting in low efficiency of the ion transport mechanism, and insufficient directional migration of anions and cations under the action of an electric field, leading to slow interfacial debonding and difficulty in achieving rapid response, this invention provides a low-voltage fast-response electrolytic adhesive tape and its preparation method.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is to design a low-voltage fast-response electrolytic adhesive tape, comprising, from top to bottom, a first release film layer, a first electrolytic adhesive layer, a conductive substrate layer, a second electrolytic adhesive layer, and a second release film layer; the first electrolytic adhesive layer and the second electrolytic adhesive layer comprise an acrylic polymer copolymerized from acrylate monomers and reactive conductive salts, wherein the acrylate monomers include soft acrylate monomers, hard acrylate monomers, and functional polar acrylate monomers, and the reactive conductive salts are firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

[0010] By weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on a total of 100 parts by weight of acrylate monomer, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight.

[0011] The soft monomer of the acrylate is butyl acrylate or 2-ethylhexyl acrylate; the hard monomer of the acrylate is methyl methacrylate or isobornyl acrylate; the functional polar monomer of the acrylate is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion.

[0012] The anion is either bis(trifluoromethanesulfonyl)imide ion or tetrafluoroborate ion.

[0013] The first and second electrolytic adhesive layers further include auxiliary components, which include conductive lithium salts, amphoteric organic ionic salts, and crosslinking agents.

[0014] The conductive lithium salt is lithium trifluoromethanesulfonyl, added in 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added in 2-5 parts by weight; the crosslinking agent is an isocyanate curing agent, added in 0.5-3 parts by weight.

[0015] The conductive substrate layer is an aluminum foil with a thickness of 30-40 μm. The surface of the aluminum foil is subjected to corona treatment or controllable weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5 μm.

[0016] This invention also provides a method for preparing a low-voltage fast-response electrolytic adhesive tape, comprising: In the reaction vessel, a mixture of acrylate monomers, reactive conductive salts and solvent ethyl acetate are added in proportion. The acrylate monomers include soft acrylate monomers, hard acrylate monomers and functional polar acrylate monomers. Nitrogen gas is introduced to purge oxygen, and azobisisobutyronitrile (AIBN) is added as an initiator to carry out a solution polymerization reaction. After the reaction is completed, an acrylic polymer solution is obtained. The reactive conductive salt is firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process. The acrylic polymer solution was transferred to a preparation vessel. Under light-protected conditions, the formulated amounts of conductive lithium salt and amphoteric organic ionic salt were added sequentially, and the mixture was stirred at low speed until it was completely dissolved and dispersed. Then, a crosslinking agent was added and stirred until the mixture was homogeneous to obtain an electrolytic adhesive. The surface of aluminum foil with a thickness of 30-40μm is subjected to corona treatment or controlled weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5μm. The electrolytic adhesive is evenly coated on the upper and lower surfaces of the treated aluminum foil and then dried immediately, forming a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively. After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively.

[0017] By weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on 100 parts by weight of total acrylate monomers, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight; the conductive lithium salt is lithium trifluoromethanesulfonyl, added 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added 2-5 parts by weight; the crosslinking agent is an isocyanate curing agent, added 0.5-3 parts by weight; the mass ratio of acrylate monomers to ethyl acetate solvent is 1:1 to 1:1.5; the initiator azobisisobutyronitrile accounts for 0.5%-1% of the total mass of acrylate monomers.

[0018] The soft monomer of the acrylate is butyl acrylate or 2-ethylhexyl acrylate; the hard monomer of the acrylate is methyl methacrylate or isobornyl acrylate; the functional polar monomer of the acrylate is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion.

[0019] This invention comprises, from top to bottom, a first release film layer, a first electrolytic adhesive layer, a conductive substrate layer, a second electrolytic adhesive layer, and a second release film layer. The first and second electrolytic adhesive layers consist of an acrylic polymer copolymerized from acrylate monomers and reactive conductive salts. The acrylate monomers include soft acrylate monomers, hard acrylate monomers, and functional polar acrylate monomers. During copolymerization, the reactive conductive salt is firmly bonded to the main chain of the acrylic polymer via covalent bonds. Because the reactive conductive salt is covalently fixed to the main chain of the acrylic polymer, it forms an "ion-fixed framework," constructing ion migration channels. This fixed ion framework helps regulate the migration paths of free ions, resulting in a highly efficient ion transport mechanism. Anions and cations migrate rapidly under the influence of an electric field, and the interface debonding process is fast, enabling rapid response. In addition, the reactive conductive salt is covalently fixed on the acrylic polymer backbone, which improves long-term stability and avoids the migration and precipitation of small molecule ionic liquids, thus significantly improving the long-term stability of the colloid and its high adhesion performance before energization. Attached Figure Description

[0020] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein: Figure 1 This is a structural diagram of the low-voltage fast-response electrolytic adhesive tape of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention are further described below with reference to the accompanying drawings: Please see also Figure 1 The low-voltage fast-response electrolytic adhesive tape of the present invention comprises, from top to bottom, a first release film layer 1, a first electrolytic adhesive layer 2, a conductive substrate layer 3, a second electrolytic adhesive layer 4, and a second release film layer 5. The first and second electrolytic adhesive layers comprise acrylic polymers copolymerized from acrylate monomers and reactive conductive salts. The acrylate monomers include soft acrylate monomers, hard acrylate monomers, and functional polar acrylate monomers. During copolymerization, the reactive conductive salt is firmly bonded to the main chain of the acrylic polymer via covalent bonds.

[0022] Soft acrylate monomers provide flexibility and initial tack, while hard acrylate monomers provide rigidity and cohesive strength. Functional polar acrylate monomers provide crosslinking sites and enhance adhesion. Reactive conductive salts are used to achieve stable ion presence and rapid migration. These reactive conductive salt molecules contain polymerizable double bonds, which, during the copolymerization of acrylate monomers, participate in free radical copolymerization via their allyl groups, firmly bonding to the acrylic polymer backbone via covalent bonds. This method avoids the migration and precipitation of small molecule ionic liquids, significantly improving the long-term stability (aging resistance) and high adhesion performance before energization of the colloid.

[0023] During copolymerization, reactive conductive salts are firmly bonded to the main chain of acrylic polymers via covalent bonds, which can prevent the migration and precipitation of small molecule ions, greatly improve durability, and avoid electrolyte leakage and contamination. The fixation of covalent bonds in reactive conductive salts is the key to achieving high stability, long life and no residue.

[0024] Because reactive conductive salts are covalently bonded to the acrylic polymer backbone, forming an "ion-fixed framework," they construct ion migration channels. This fixed ion framework helps regulate the migration paths of free ions, resulting in a highly efficient ion transport mechanism. Anions and cations migrate rapidly and directionally under the influence of an electric field, leading to fast interfacial debonding and rapid response. Furthermore, the covalent bonding of reactive conductive salts to the acrylic polymer backbone enhances long-term stability and prevents the migration and precipitation of small-molecule ionic liquids, significantly improving the long-term stability of the colloid and its high adhesion before energization.

[0025] In this specific embodiment, by weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on a total of 100 parts by weight of acrylate monomer, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight.

[0026] In this specific embodiment, the soft acrylate monomer is butyl acrylate or 2-ethylhexyl acrylate, the glass transition temperature (Tg) of its homopolymer is below -20°C; the hard acrylate monomer is methyl methacrylate or isobornyl acrylate; the functional polar acrylate monomer is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion.

[0027] In this specific embodiment, the anion is a bis(trifluoromethanesulfonyl)imide ion or a tetrafluoroborate ion.

[0028] To achieve a rapid electrical response, a highly efficient migratory ionic salt is introduced. Here, the fixed ionic framework helps regulate the migration paths of free ions, improving their long-term stability, thus achieving a synergy between a 'stable framework' and 'efficient conduction'. The first and second electrolytic adhesive layers also include auxiliary components, which include conductive lithium salts, amphoteric organic ionic salts, and crosslinking agents.

[0029] The addition of conductive lithium salts primarily utilizes the small radius and rapid migration of lithium ions, acting as the main migrating ions to significantly improve response speed. The addition of amphoteric organic ionic salts leverages their moderate ion size, providing internal plasticizing effects, reducing polymer chain segment movement resistance, and creating a better environment for lithium ion migration. Crosslinking agents react with functional groups such as hydroxyl groups (derived from hydroxyethyl acrylate) on the acrylic polymer chains to form a suitable three-dimensional crosslinked network, greatly enhancing the cohesive strength, heat resistance, and electrolyte resistance of the adhesive layer.

[0030] In this specific embodiment, the conductive lithium salt is lithium trifluoromethanesulfonyl, added in 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added in 2-5 parts by weight; and the crosslinking agent is an isocyanate curing agent, added in 0.5-3 parts by weight.

[0031] Of course, other auxiliary components can also be added, including leveling agents (such as BYK series, 0.1-1 parts), defoamers (0.05-0.5 parts), etc., to ensure the smooth progress of the coating process and the uniformity of the adhesive layer quality.

[0032] This invention employs a synergistic design of "fixed ionic framework + free-migrating ions". The fixed framework ensures the long-term reliability of the system, while the free ions provide excellent immediate electrical properties. The combination of the two aims to achieve a performance balance between the high efficiency of physically blended systems and the stability of fully reactive systems.

[0033] The conductive substrate layer 3 is not only a current conductor, but its interface properties are also crucial to triggering performance. In this specific embodiment, the conductive substrate layer is an aluminum foil with a thickness of 30-40 μm. The surface of the aluminum foil is subjected to corona treatment or controlled weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5 μm. The aluminum foil has good conductivity and flexibility, and the precise control of the surface roughness Ra within the range of 0.8-1.5 μm ensures that the adhesive has fast and stable electrical response performance under low voltage (≤12V).

[0034] The core purpose and mechanism of aluminum foil processing are as follows: 1. Removing the oxide layer to form microscopic conductive channels: The dense alumina layer on the surface of aluminum foil is an insulator. By etching to increase roughness, the local oxide layer can be physically removed at the microscopic level, exposing fresh aluminum substrate and forming dispersed microscopic conductive points. This is the physical basis for establishing effective electrical contact.

[0035] 2. Increased actual contact area and reduced interfacial contact resistance: The peak-valley structure of the rough surface significantly increases the actual mechanical contact and interlocking area between the adhesive and the substrate. This not only improves the wetting and anchoring of the adhesive, but more importantly, it provides countless parallel microscopic paths for current transmission in the interface layer, thereby greatly reducing the macroscopic interfacial contact resistance.

[0036] 3. Ensure effective electric field distribution under low voltage: Under low voltage conditions of ≤12V, the electric field strength driving ion migration is limited. If the interface resistance is too high (e.g., when the roughness Ra<0.5µm, the contact area is insufficient and the oxide layer is not effectively destroyed), most of the applied voltage (ohmic loss) will drop onto the high-resistance interface, failing to effectively penetrate into the adhesive layer to drive ion migration. This directly manifests as the inability to form a stable current density, resulting in a slow and uncontrollable ion migration process, leading to a significant extension of the debonding time or even failure.

[0037] 4. Significance of Roughness Optimization: Controlling Ra within the range of 0.8-1.5 μm represents the optimal balance between "removing the oxide layer / providing sufficient conductive contact points" and "avoiding excessive roughness that could lead to incomplete adhesive layer filling or stress concentration." This optimized interface ensures that, under low voltage, the electric field can act efficiently and uniformly across the entire adhesive layer, thereby activating a rapid and controllable ion migration process.

[0038] When a DC voltage of ≤12V is applied between the conductive substrate layer and the substrate serving as the other electrode: the electric field rapidly penetrates the optimized low-impedance interface and acts on the acrylic adhesive layer. Reactive conductive salts bonded to the acrylic polymer network ionize, and additional conductive lithium salts also provide a large number of migratable ions. Driven by the electric field, ions rapidly and directionally migrate along low-energy paths composed of acrylic polymer segments and polar groups. Ions rapidly accumulate at the adhesive interface, creating reverse osmotic pressure and causing a dramatic change in the chemical and physical properties of the interface layer, thus achieving rapid and clean peeling.

[0039] The preparation method of the low-voltage fast-response electrolytic adhesive tape of this invention mainly includes three steps: synthesis of acrylic polymer, formulation of adhesive, and coating and lamination. Specifically, it includes: I. Synthesis of Acrylic Polymers In a reaction vessel, a mixture of acrylate monomers, a reactive conductive salt, and ethyl acetate solvent are added in proportion. The acrylate monomers include soft acrylate monomers, hard acrylate monomers, and functional polar acrylate monomers. Ethyl acetate solvent is used to dissolve the acrylate monomers and initiate polymerization.

[0040] Nitrogen gas is introduced to purge oxygen, and azobisisobutyronitrile (AIBN) is added as an initiator to carry out a solution polymerization reaction. After the reaction is completed, an acrylic polymer solution is obtained. The reactive conductive salt is firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

[0041] II. Preparation of Adhesives The acrylic polymer solution was transferred to a preparation vessel. Under light-protected conditions, the formulated amounts of conductive lithium salt and amphoteric organic ionic salt were added sequentially, and the mixture was stirred at low speed until it was completely dissolved and dispersed. Then, a crosslinking agent was added and stirred until the mixture was homogeneous to obtain an electrolytic adhesive.

[0042] The surface of aluminum foil with a thickness of 30-40μm is subjected to corona treatment or controlled weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5μm.

[0043] III. Coating and Laminating The electrolytic adhesive is evenly applied to the upper and lower surfaces of the treated aluminum foil, and then dried immediately to form a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively.

[0044] After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively.

[0045] In this specific embodiment, by weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on 100 parts by weight of total acrylate monomer, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight; the conductive lithium salt is lithium trifluoromethanesulfonyl, added 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added 2-5 parts by weight; the crosslinking agent is an isocyanate curing agent, added 0.5-3 parts by weight; the mass ratio of acrylate monomer to solvent ethyl acetate is 1:1 to 1:1.5; the initiator azobisisobutyronitrile accounts for 0.5%-1% of the total mass of acrylate monomer.

[0046] In this specific embodiment, the soft monomer of acrylate is butyl acrylate or 2-ethylhexyl acrylate; the hard monomer of acrylate is methyl methacrylate or isobornyl acrylate; the functional polar monomer of acrylate is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion. Example

[0047] By weight, 60 parts of soft acrylate monomer, 10 parts of hard acrylate monomer, 2 parts of functional polar acrylate monomer, and 0.36 parts of reactive conductive salt were added to 72 parts of ethyl acetate solvent for polymerization. After the reaction was completed, an acrylic polymer solution was obtained. The reactive conductive salt was firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

[0048] The acrylic polymer solution was transferred to a preparation vessel, and 3 parts by weight of conductive lithium salt and 2 parts by weight of amphoteric organic ionic salt were added. The solution was then completely dissolved and dispersed under low-speed stirring. Then, 0.5 parts by weight of crosslinking agent was added and stirred until the mixture was homogeneous to obtain an electrolytic adhesive.

[0049] The surface of a 30μm thick aluminum foil is subjected to corona treatment or controlled weak acid / alkali etching to precisely control its surface roughness Ra within the range of 0.8μm.

[0050] The electrolytic adhesive is evenly applied to the upper and lower surfaces of the treated aluminum foil, and then dried immediately to form a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively.

[0051] After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively. Example

[0052] By weight, 80 parts of soft acrylate monomer, 20 parts of hard acrylate monomer, 10 parts of functional polar acrylate monomer, and 27.5 parts of reactive conductive salt were added to 165 parts of ethyl acetate solvent for polymerization. After the reaction was completed, an acrylic polymer solution was obtained. The reactive conductive salt was firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

[0053] The acrylic polymer solution was transferred to a preparation vessel, and 8 parts by weight of conductive lithium salt and 5 parts by weight of amphoteric organic ionic salt were added. The solution was then completely dissolved and dispersed under low-speed stirring. Then, 3 parts by weight of crosslinking agent were added and stirred until the mixture was homogeneous to obtain an electrolytic adhesive.

[0054] The surface of an aluminum foil with a thickness of 40 μm is subjected to corona treatment or controlled weak acid / alkali etching to precisely control its surface roughness Ra within the range of 1.5 μm.

[0055] The electrolytic adhesive is evenly applied to the upper and lower surfaces of the treated aluminum foil, and then dried immediately to form a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively.

[0056] After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively. Example

[0057] By weight, 70 parts of soft acrylate monomer, 15 parts of hard acrylate monomer, 6 parts of functional polar acrylate monomer, and 10.92 parts of reactive conductive salt were added to 113.75 parts of ethyl acetate solvent for polymerization. After the reaction was completed, an acrylic polymer solution was obtained. The reactive conductive salt was firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

[0058] The acrylic polymer solution was transferred to a preparation vessel, and 5.5 parts by weight of conductive lithium salt and 3.5 parts by weight of amphoteric organic ionic salt were added. The solution was then completely dissolved and dispersed under low-speed stirring. Then, 1.25 parts by weight of crosslinking agent were added and stirred until the mixture was homogeneous to obtain the electrolytic adhesive.

[0059] The surface of an aluminum foil with a thickness of 35.5 μm is subjected to corona treatment or controlled weak acid / alkali etching to precisely control its surface roughness Ra within the range of 1.15 μm.

[0060] The electrolytic adhesive is evenly applied to the upper and lower surfaces of the treated aluminum foil, and then dried immediately to form a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively.

[0061] After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively.

[0062] After testing, the trigger voltage of the electrolytic adhesive tapes in Examples 1, 2 and 3 was less than 12V, the unbonding time was less than 12 seconds, the initial 180° peel strength was less than 12 N / 25mm, the unbonding time after aging at 85℃ / 85%RH for 500h was extended to less than 15 seconds, the number of times they could be reused was greater than or equal to 4, and there was basically no adhesive residue. Example

[0063] I. Synthesis of Acrylic Polymers In a reactor equipped with a stirrer, condenser, thermometer, and nitrogen inlet, a mixture of soft acrylate monomers, hard acrylate monomers, functional polar acrylate monomers, reactive conductive salts, and ethyl acetate solvent is added in proportion, wherein the mass ratio of acrylate monomers to solvent is approximately 1:1 to 1:1.5. Nitrogen is introduced to purge oxygen, and the temperature is raised to 70-80°C. Azobisisobutyronitrile (AIB) initiator, comprising 0.5%-1% of the total mass of the acrylate monomers, is slowly added. The solution polymerization reaction is carried out at this temperature for 4-6 hours. After the reaction, a transparent acrylic polymer solution is obtained, in which the reactive conductive salt is firmly covalently bonded to the main chain of the acrylic polymer during copolymerization.

[0064] The synthesized acrylic polymer solution was transferred to a preparation vessel. Under light-protected conditions, the formulated amounts of conductive lithium salt and amphoteric organic ionic salt were added sequentially, and the mixture was stirred at low speed until completely dissolved and dispersed. Finally, a crosslinking agent and other additives were added at room temperature, and the mixture was stirred for 1-2 hours until homogeneous, yielding the final electrolytic adhesive.

[0065] II. Substrate Treatment The aluminum foil substrate is surface activated by a corona treatment device with a power of 1.5kW and a linear speed of 10m / min, which precisely controls the surface roughness Ra of the aluminum foil substrate within the range of 0.8μm.

[0066] III. Coating and Drying The prepared electrolytic adhesive is evenly applied to both surfaces of the activated aluminum foil using a micro-gravure coating head, controlling the wet film thickness to be 100-120 μm. It then immediately enters a segmented drying channel: the first zone has a temperature of 65-75℃ to evaporate most of the solvent; the second zone has a temperature of 90-100℃ to promote complete cross-linking. The total drying time is controlled to be 3-5 minutes.

[0067] IV. Compounding and Curing After drying, immediately laminate PET release film onto the surfaces of the upper and lower adhesive layers, with a thickness of 20-45 μm. After winding, cure at room temperature (25±5℃) for 24-48 hours to ensure the crosslinking reaction is fully completed. Finally, slit to obtain the finished electrolytic adhesive tape. Example

[0068] Prepare the following ingredients by weight: Soft acrylate monomer: 75 parts, the soft acrylate monomer is 2-ethylhexyl acrylate, used to provide flexibility and initial tack.

[0069] Acrylic hard monomer: 15 parts, the acrylate hard monomer is methyl methacrylate, used to provide rigidity and cohesive strength.

[0070] Acrylic functional polar monomer: 5 parts. The acrylate functional polar monomer is hydroxyethyl acrylate, which is used to provide crosslinking sites and enhance adhesion.

[0071] Reactive conductive salt: 8 parts. The reactive conductive salt is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt containing allyl group. Its cationic structure has the general formula [CH2=CH-CH2-R-Im]+, where R is ethylidene and Im is an imidazole ring.

[0072] Conductive lithium salt: 5 parts. The conductive lithium salt is lithium trifluoromethanesulfonyl, which is used to provide lithium ions with high mobility.

[0073] Amphoteric organic ionic salt: 3 parts. The amphoteric organic ionic salt used is pyridinium salt of hydroxypropanesulfonate, which is used to reduce ion migration resistance.

[0074] Initiator: 0.8 parts, the initiator is azobisisobutyronitrile.

[0075] Solvent: 120 parts, using ethyl acetate as the polymerization reaction medium.

[0076] Crosslinking agent: 1.5 parts. The crosslinking agent is an isocyanate curing agent, which is added before coating.

[0077] The preparation method of this embodiment is as follows: I. Premixing and Deoxygenation In a 1-liter four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube, add weighed 2-ethylhexyl acrylate, methyl methacrylate, hydroxyethyl acrylate, a reactive conductive salt, and 80% of the total amount of ethyl acetate solvent. The remaining 20% ​​of the ethyl acetate solvent will be added later. Start the stirrer at 300 rpm and simultaneously bubble nitrogen gas through it for 30 minutes to remove oxygen from the reaction system.

[0078] II. Heating Polymerization The reaction system was heated to 70±2℃, and the initiator was added all at once. This temperature was maintained, and the solution polymerization reaction was carried out for 5 hours under nitrogen protection.

[0079] III. Additives After the reaction was complete, the system was cooled to below 40°C. Conductive lithium salt and amphoteric organic ionic salt were added sequentially while stirring until completely dissolved and uniformly dispersed, yielding a viscous acrylic polymer solution.

[0080] IV. Coating, Drying, Laminating and Curing The prepared acrylic polymer adhesive is coated onto aluminum foil, dried, and then laminated with a PET release film. After curing, it is finally slit to obtain the finished electrolytic adhesive tape.

[0081] To verify the effectiveness of the present invention, the following three experimental examples are provided and their performance is compared with that of two comparative examples.

[0082] The table below lists three targeted experimental formulations (parts by weight), demonstrating a scheme to achieve performance regulation by adjusting key components.

[0083]

[0084] Fluorinated acrylates were introduced in Experiments 1-3.

[0085] Comparative Example 1 is a traditional physical mixing type: 100 parts of ordinary acrylate emulsion were directly physically blended with 12 parts of small molecule ionic liquid conductive salt and 8 parts of conductive lithium salt (LiTFSI), without using reactive conductive salt copolymerization technology.

[0086] Comparative Example 2 is an over-crosslinked type: the formulation is similar to that of Example 3, but the amount of crosslinking agent is increased to 4.0 parts, in order to explore the effect of excessively high crosslinking density.

[0087] Key performance tests were performed on the experimental and comparative samples, and the results are recorded in the table below.

[0088]

[0089] As can be seen from the table above, the low-voltage fast-response acrylic electrolytic adhesive tape provided by the present invention is significantly superior to the prior art represented by the comparative example in terms of initial bonding strength, trigger voltage, response speed, long-term stability and reusability.

[0090] Advantages of Experiments 1, 2, and 3: They demonstrate that reactive conductive salts are key to performance improvement. They are covalently bonded to the polymer backbone, fundamentally solving the core problem of poor stability caused by easy migration and precipitation of small molecule ionic liquid conductive salts (Comparative Example 1).

[0091] Synergistic effect of components: The introduction of fluorine-containing monomers in Experiments 1 to 3, together with the synergistic optimization of reactive conductive salts, lithium salts, etc., achieved a balance and improvement in performance.

[0092] The shortcomings of the comparative examples: Comparative example 1 shows that there are inherent shortcomings in traditional physical mixing technology; Comparative example 2 proves that excessive cross-linking will impair performance, which highlights the scientific nature of the formulation design of this invention.

[0093] The short unbinding times of Experiments 1, 2, and 3 demonstrate the significant effect of covalent bond fixation in preventing ion migration and precipitation. The high reusability proves that reactive conductive salts can greatly improve durability, and the absence of residue demonstrates that covalent bond fixation avoids electrolyte leakage and contamination. The data sufficiently demonstrate that covalent bond fixation in reactive conductive salts is key to achieving high stability, long lifespan, and residue-free operation.

[0094] All experimental examples successfully achieved rapid debonding (≤12 seconds) under safe low voltage (≤12V) and solved the problem of residual adhesive, with performance significantly superior to the comparative examples representing existing technologies. This fully demonstrates the effectiveness and advancement of the technical solution of this invention, especially in successfully solving the industry challenge of balancing low-voltage driving and rapid response through the molecular-level bonding of reactive conductive salts and the synergistic optimization of multiple ion transport aids.

[0095] The present invention has the following advantages: (1) Low voltage drive and fast response: The effective trigger voltage is significantly reduced from the conventional 20V or more to below 12V, and the unbinding time is shortened to less than 12 seconds, improving safety and efficiency.

[0096] (2) Excellent balance of bonding performance: Through the molecular design of acrylic polymers and the introduction of reactive conductive salts, high initial bonding strength before energization and rapid peeling without residue after energization are achieved at the same time.

[0097] (3) Excellent long-term stability: The covalent bonding of reactive conductive salts effectively prevents ion migration and precipitation, enabling the tape to maintain stable performance under harsh environments such as high temperature and high humidity, and greatly improving durability.

[0098] (4) Mature and controllable process: Based on the mature acrylic pressure-sensitive adhesive production process, the raw materials are readily available, the conditions are mild, and it is suitable for continuous large-scale production, which has high commercial conversion value.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-voltage fast-response electrolytic adhesive tape, comprising, from top to bottom, a first release film layer, a first electrolytic adhesive layer, a conductive substrate layer, a second electrolytic adhesive layer, and a second release film layer; characterized in that: The first electrolytic adhesive layer and the second electrolytic adhesive layer comprise an acrylic polymer copolymerized from acrylate monomers and reactive conductive salts. The acrylate monomers include soft acrylate monomers, hard acrylate monomers, and functional polar acrylate monomers. The reactive conductive salts are firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process.

2. The low-voltage fast-response electrolytic adhesive tape according to claim 1, characterized in that: By weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on a total of 100 parts by weight of acrylate monomer, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight.

3. The low-voltage fast-response electrolytic adhesive tape according to claim 2, characterized in that: The soft monomer of the acrylate is butyl acrylate or 2-ethylhexyl acrylate; the hard monomer of the acrylate is methyl methacrylate or isobornyl acrylate; the functional polar monomer of the acrylate is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion.

4. The low-voltage fast-response electrolytic adhesive tape according to claim 3, characterized in that: The anion is either bis(trifluoromethanesulfonyl)imide ion or tetrafluoroborate ion.

5. The low-voltage fast-response electrolytic adhesive tape according to claim 1, characterized in that: The first and second electrolytic adhesive layers further include auxiliary components, which include conductive lithium salts, amphoteric organic ionic salts, and crosslinking agents.

6. The low-voltage fast-response electrolytic adhesive tape according to claim 5, characterized in that: The conductive lithium salt is lithium trifluoromethanesulfonyl, added in 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added in 2-5 parts by weight; the crosslinking agent is an isocyanate curing agent, added in 0.5-3 parts by weight.

7. The low-voltage fast-response electrolytic adhesive tape according to claim 1, characterized in that: The conductive substrate layer is an aluminum foil with a thickness of 30-40 μm. The surface of the aluminum foil is subjected to corona treatment or controllable weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5 μm.

8. A method for preparing a low-voltage fast-response electrolytic adhesive tape, characterized in that... include: In the reaction vessel, a mixture of acrylate monomers, reactive conductive salts and solvent ethyl acetate are added in proportion. The acrylate monomers include soft acrylate monomers, hard acrylate monomers and functional polar acrylate monomers. Nitrogen gas is introduced to purge oxygen, and azobisisobutyronitrile (AIBN) is added as an initiator to carry out a solution polymerization reaction. After the reaction is completed, an acrylic polymer solution is obtained. The reactive conductive salt is firmly bonded to the main chain of the acrylic polymer in the form of covalent bonds during the copolymerization process. The acrylic polymer solution was transferred to a preparation vessel. Under light-protected conditions, the formulated amounts of conductive lithium salt and amphoteric organic ionic salt were added sequentially, and the mixture was stirred at low speed until it was completely dissolved and dispersed. Then, a crosslinking agent was added and stirred until the mixture was homogeneous to obtain an electrolytic adhesive. The surface of aluminum foil with a thickness of 30-40μm is subjected to corona treatment or controlled weak acid / alkali etching treatment to precisely control its surface roughness Ra within the range of 0.8-1.5μm. The electrolytic adhesive is evenly coated on the upper and lower surfaces of the treated aluminum foil and then dried immediately, forming a first electrolytic adhesive layer and a second electrolytic adhesive layer on the upper and lower surfaces of the aluminum foil, respectively. After drying, PET release films are immediately laminated onto the surfaces of the first electrolytic adhesive layer and the second electrolytic adhesive layer to form the first release film layer and the second release film layer, respectively.

9. The low-voltage fast-response electrolytic adhesive tape according to claim 8, characterized in that: By weight, the soft acrylate monomer, hard acrylate monomer, and functional polar acrylate monomer are 60-80 parts by weight, 10-20 parts by weight, and 2-10 parts by weight, respectively; based on 100 parts by weight of total acrylate monomers, the amount of the reactive conductive salt added is 0.5 to 25 parts by weight; the conductive lithium salt is lithium trifluoromethanesulfonyl, added 3-8 parts by weight; the amphoteric organic ionic salt is pyridinium hydroxypropanesulfonate, added 2-5 parts by weight; the crosslinking agent is an isocyanate curing agent, added 0.5-3 parts by weight; the mass ratio of acrylate monomers to ethyl acetate solvent is 1:1 to 1:1.5; the initiator azobisisobutyronitrile accounts for 0.5%-1% of the total mass of acrylate monomers.

10. The low-voltage fast-response electrolytic adhesive tape according to claim 9, characterized in that: The soft monomer of the acrylate is butyl acrylate or 2-ethylhexyl acrylate; the hard monomer of the acrylate is methyl methacrylate or isobornyl acrylate; the functional polar monomer of the acrylate is acrylic acid, hydroxyethyl acrylate or glycidyl methacrylate; the reactive conductive salt is a reactive organic ionic liquid containing an allyl imidazolium cation, with the general formula: [CH2=CH-CH2-R-Im]+ X-, where: Im represents an imidazolium ring, R is a linking group, and X- is an anion.

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