Electrolyte-resistant double-sided adhesive tape with acrylic ultrathin substrate and preparation method

Abstract

The application discloses an electrolyte-resistant double-sided adhesive tape with an acrylic ultrathin substrate, which comprises, in sequence, a pressure-sensitive adhesive layer, a substrate layer and a hot melt adhesive layer; the substrate layer has a thickness of 0.2-1 microns; the pressure-sensitive adhesive layer has a thickness of 3.5-6.5 microns and comprises an alpha-olefin polymer, a modified polyolefin, a styrene block copolymer, a petroleum resin and a viscosity regulator; and the hot melt adhesive layer has a thickness of 3.5-6.5 microns and comprises an alpha-olefin polymer, a modified polyolefin, a styrene block copolymer and a petroleum resin. The application further provides a preparation method of the electrolyte-resistant double-sided multilayer adhesive tape with the ultrathin substrate, which comprises, in sequence, hot melt adhesive layer coating, substrate layer coating and pressure-sensitive adhesive layer coating. The multilayer adhesive tape has a relatively thin overall thickness, saves space for a battery and improves the energy density of the battery, has excellent bonding performance, electrolyte resistance and flexibility, can improve the drop resistance of the battery and ensures long-term safe use of the battery.

Description

[0001] This application is a divisional application of the invention patent application with application number 202310029912.0 and invention title "An Electrolyte-Resistant Double-Sided Multilayer Adhesive Tape with an Ultra-Thin Substrate and its Preparation Method". Technical Field

[0002] This invention belongs to the technical field of double-sided adhesive tape for batteries, and particularly relates to an electrolyte-resistant double-sided adhesive tape with an acrylic ultrathin substrate and its preparation method. Background Technology

[0003] In recent years, consumer electronics have shown increasingly prominent trends towards slimmer, lighter designs, ergonomic shapes, and mobile connectivity. Furthermore, with the expansion of radio frequency bands, increased pixel density, and improved processor performance in consumer electronics, energy consumption and heat generation have become increasingly prominent issues. This has led to a growing demand for lightweight, compact, high-capacity, high-energy-density, customizable, and fast-charging lithium-ion batteries. To address the trend towards thinner and lighter consumer electronics, the internal space of the battery cell is maximized for the positive and negative electrode materials, thereby increasing energy density. Current methods include: using silicon-carbon negative electrode materials; thinning aluminum foil, copper foil, and separators; reducing the overhang area (the portion of the negative electrode sheet extending beyond the positive and negative electrode sheets in both length and width); and thinning the tab protection tape, lithium plating protection tape, and cell / aluminum-plastic film bonding tape. Providing thin, highly adhesive, and safe and stable tapes for batteries has become a major research direction in this field.

[0004] Patent CN105950043B discloses an adhesive tape that can improve the drop resistance of batteries and its preparation method. The adhesive tape comprises a five-layer structure: the first layer is a pressure-sensitive adhesive with room temperature adhesion, used to bond the outer surface of the battery electrode assembly; the second layer is a substrate; the third layer is a primer, used to bond the substrate and the fourth layer; the fourth layer is an adhesive layer, used to bond the inner surface of the battery casing; and the fifth layer is a double-sided release film. The total thickness of the adhesive tape is 16-35 μm, and the materials used do not react with the electrolyte. It mainly relies on heating or pressurization to achieve adhesion between the battery electrode assembly and the inner surface of the casing, and the bonding strength is high. Satisfactory results can be achieved with a very small area in the battery. The substrate of this invention is made of commonly used substrates in the field, such as PP (polypropylene), PA (polyamide) or PET (polyethylene terephthalate). In order to ensure the basic requirements of the mechanical properties of the adhesive tape, it is difficult to reduce the thickness of the substrate, resulting in a large total thickness of the adhesive tape. The main means to reduce the total thickness is to reduce the thickness of the pressure-sensitive adhesive and the adhesive layer, which poses a risk of insufficient adhesive strength of the adhesive tape and damage to the battery.

[0005] Patent CN109517533A discloses a substrate-free hot-melt double-sided adhesive tape for lithium batteries, comprising a first pressure-sensitive adhesive layer, a second adhesive layer, and a third double-sided release film arranged sequentially from top to bottom. The first pressure-sensitive adhesive layer is tacky at room temperature and is used to bond the outer surface of the lithium battery cell. The second adhesive layer is low-tack at room temperature and is used to bond the inner surface of the aluminum-plastic film of the battery casing. The third double-sided release film is used to prevent the back sides of the first pressure-sensitive adhesive layer and the second adhesive layer from sticking together when the double-sided tape is rolled up. The total thickness of the substrate-free hot-melt double-sided adhesive tape for lithium batteries is 10-25 μm. The materials used in the tape do not react with the electrolyte and can maintain good stability in the electrolyte. It mainly relies on heating and pressure to bond the lithium battery cell and the outer packaging aluminum-plastic film, resulting in high bonding strength. At the same time, the substrate-free design reduces the tape thickness to below 25 μm, increasing the energy density of the battery, reducing stress, and improving the battery's drop resistance. This invention reduces the thickness of the tape through a substrate-free design, but interference easily occurs between the first pressure-sensitive adhesive layer and the second adhesive layer. During room temperature storage, the pressure-sensitive adhesive layer easily loses its tackiness, while the hot melt adhesive layer undesirably exhibits pressure sensitivity. When the release film of the hot melt adhesive layer is removed, it easily sticks to the equipment, causing the aluminum foil of the battery cell to tear. Furthermore, both adhesive layers contain 1-2% antioxidants, which have reducing properties and pose an electrochemical risk when used in lithium batteries, potentially leading to lithium plating problems.

[0006] Therefore, how to obtain a double-sided tape with an ultra-thin substrate and small overall thickness, good adhesion and electrolyte resistance, which can save space for batteries and improve battery drop performance, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of the existing technology, the present invention aims to provide an electrolyte-resistant double-sided adhesive tape with an acrylic ultrathin substrate and a preparation method thereof. The tape has a multi-layer structure, which not only has a thin overall thickness, but also has good adhesion and electrolyte resistance, saving space for the battery and increasing the battery energy density. At the same time, the tape has excellent flexibility, with an elongation of up to 400%, which effectively absorbs energy through deformation when the battery is subjected to external impact, improving the battery's drop resistance and ensuring long-term safe use of the battery.

[0008] Specifically, in a first aspect, the present invention provides an electrolyte-resistant double-sided multilayer tape with an ultra-thin substrate, comprising, in sequence, a pressure-sensitive adhesive layer, a substrate layer and a hot melt adhesive layer;

[0009] Substrate layer, thickness 0.2-1μm;

[0010] Pressure-sensitive adhesive layer, 3.5-6.5μm thick, comprising the following components by weight:

[0011]

[0012] The hot melt adhesive layer, with a thickness of 3.5-6.5 μm, comprises the following components by weight:

[0013]

[0014]

[0015] The modified polyolefin is selected from at least one of maleic anhydride modified polyolefin and acrylic acid modified polyolefin.

[0016] Specifically, the modified polyolefin is selected from at least one of maleic anhydride-modified polyolefin and acrylic acid-modified polyolefin. Among them, acrylic acid-modified polyolefin can be mainly modified by grafting and copolymerization, with ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer being preferred copolymerization modifications.

[0017] Maleic anhydride-modified polyolefins, such as MA-APAO:

[0018]

[0019] In formula (A), a and d are 50-20,000, and b and c are 10-400;

[0020] Acrylic-modified polyolefins, such as AA-APAO:

[0021]

[0022] In equation (B), a and d are 50-20,000, and b and c are 10-400;

[0023] Ethylene-acrylic acid copolymer (EAA):

[0024]

[0025] In formula (C), m / n = 4:1-19:1, and m is 50-20,000;

[0026] Ethylene-methacrylic acid copolymer (EMAA):

[0027]

[0028] In equation (D), m / n = 4:1-19:1, and m is 50-20,000.

[0029] The double-sided multilayer tape of this invention provides satisfactory adhesive strength at a thickness of less than 15 μm, with a minimum thickness of less than 8 μm. Compared to double-sided tapes in the art that are often tens of micrometers thick, this provides more effective space for the battery and improves battery energy density. Furthermore, due to the barrier effect of the substrate layer, there is no risk of interference between the pressure-sensitive adhesive layer and the hot melt adhesive layer of this invention, which could degrade the tape's performance.

[0030] Furthermore, the α-olefin polymer is selected from at least one of polyethylene, polypropylene, amorphous polyα-olefin, and ethylene octene copolymer; the styrene block copolymer includes at least one of block copolymers of styrene and butadiene, and block copolymers of styrene and isoprene.

[0031] Amorphous polyalphaolefin resins, such as APAO:

[0032]

[0033] In equation (Ⅰ), both m and n are 50-20,000;

[0034] Ethylene and octene copolymer (POE):

[0035]

[0036] In equation (Ⅱ), both m and n are 50-20,000.

[0037] Specifically, styrene block copolymers include block copolymers of styrene and butadiene, and / or block copolymers of styrene and isoprene.

[0038] Styrene-ethylene-butadiene-styrene copolymer (SEBS):

[0039]

[0040] In equation (Ⅲ), a, b, c, and d are 50-20,000;

[0041] Styrene-isoprene-styrene block copolymer (SIS):

[0042]

[0043] In equation (Ⅳ), a, b, and c are 50-20,000.

[0044] Petroleum resins include at least one of aliphatic resins (C5), alicyclic resins (DCPD), aromatic resins (C9), aliphatic / aromatic copolymers (C5 / C9), and hydrogenated petroleum resins. Hydrogenated petroleum resins include at least one of C5 hydrogenated petroleum resin and C9 hydrogenated petroleum resin. Petroleum resins are mainly used to improve viscosity, wettability, and initial tack. Petroleum resins have a high softening point, which can improve temperature resistance and chemical resistance.

[0045] Viscosity modifiers mainly include mineral oil, liquid hydrogenated tackifying resin and liquid hydrogenated polybutadiene (PolyBD), and are mainly used to improve the flowability of pressure-sensitive adhesive layers (i.e. reduce viscosity), improve their low-temperature resistance (reduce Tg), improve the compatibility of the components of the pressure-sensitive adhesive and improve its wettability.

[0046] To prevent the pressure-sensitive adhesive layer and the hot melt adhesive layer from sticking together when this double-sided multilayer tape is rolled into a material, the present invention further includes a release film. Specifically:

[0047] A first single-sided release film is provided on the outside of the pressure-sensitive adhesive layer, and a second single-sided release film is provided on the outside of the hot melt adhesive layer. The release force of the first single-sided release film towards the inside of the pressure-sensitive adhesive layer is 2-8 gf / inch, and the release force of the second single-sided release film towards the inside of the hot melt adhesive layer is 10-20 gf / inch; or

[0048] A double-sided release film is provided on the outside of the hot melt adhesive layer. The release force of the double-sided release film on the inside of the hot melt adhesive layer is 10-20 gf / inch, and the release force on the outside is 5-10 gf / inch.

[0049] There are various ways to set the release film, and you can set it as needed. When using it, simply remove the release film according to the specific operating sequence. The release film can be PET, BOPP, or double-sided silicone-free release film, etc., which are commonly used in this field, and there are no particular limitations on the thickness.

[0050] To obtain a thin substrate layer with excellent overall performance, the substrate layer of the present invention preferably uses an epoxy system or an acrylic system.

[0051] Furthermore, when an epoxy system is selected for the substrate layer, the substrate layer comprises the following components by weight:

[0052]

[0053] And solvents, controlling the solid content between 5% and 30%.

[0054] The solvent is selected from at least one of ethyl acetate, butyl acetate, and butanone.

[0055] The epoxy resin is selected from at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0056] The UV initiator is selected from at least one of diphenyliodonium hexafluorophosphate, 4-(phenylthio)phenyldiphenylthiohexafluorophosphate, and bis(4-(diphenylsulfonium)phenyl)sulfide-bishexafluorophosphate.

[0057] The thermosetting agent for the substrate layer is triphenylthionium hexafluoroantimonate or an anhydride curing agent. Among them, the anhydride curing agents include methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, and dodecyl succinic anhydride.

[0058] The diluent in the substrate layer includes at least one selected from alkylene glycidyl ether, butyl glycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, polypropylene glycol diglycidyl ether, C12-14 fatty glycidyl ether, benzyl glycidyl ether, 1,6-hexanediol diglycidyl ether, o-tolyl glycidyl ether, and neopentyl glycol diglycidyl ether. The solvent in the substrate layer includes ethyl acetate, butyl acetate, and methyl ethyl ketone (MEK).

[0059] Furthermore, the toughening rubber in the substrate layer comprises 20-50 parts by weight, selected from at least one of nitrile butadiene rubber (NBR), hydroxyl-terminated liquid nitrile butadiene rubber (HTBN), amino-terminated liquid nitrile butadiene rubber (ATBN), carboxyl-terminated nitrile butadiene rubber (CTBN), acrylate core-shell rubber, and natural rubber. Although not preferred, commonly used organic toughening agents in the art, such as polyether polyols (PPG), may also be selected as needed.

[0060] During the mixing of epoxy resin and toughened rubber, phase separation occurs in the system. The toughened rubber initially forms large, dispersed particles in the mixture, resembling a "sea-island" structure. Simultaneously, the epoxy groups may react with the active groups in the toughened rubber to form polymers with flexible chain segments. When molecules are subjected to stress and deformation, the binding force is reduced, making the polymer more susceptible to plastic deformation. When subjected to external force, the phase-separated rubber particles act like "large rivets" within the epoxy matrix, facilitating the formation of micro-shear bands, thereby inducing plastic deformation in the system.

[0061] Therefore, when using rubber-based toughening agents to toughen epoxy resin, the "particle rivets" formed after the large rubber particles separate induce shear deformation, while the small rubber particles create shear bands through cavities, thereby improving the toughness of the epoxy resin. However, when the content of toughening rubber is too high and it has too many active groups that react with the epoxy groups, it can cause the rubber particles in the cured system to agglomerate, or prevent the curing agent from fully reacting with the epoxy groups, easily leading to a decrease in mechanical properties. Therefore, the amount of toughening rubber used should not be too large.

[0062] Furthermore, the substrate layer also includes 0.5-1.5 parts by weight of modified nano-SiO2, prepared in the following manner:

[0063] Step 1: Dilute KH550 with acetone, the amount of KH550 being 1-1.5% of the weight of nano-SiO2; preferably, the dilution process is carried out by mixing evenly with a magnetic stirrer;

[0064] Step 2: Add nano-SiO2 and heat the mixture to 90-100℃, stir for 20-30 minutes to obtain modified nano-SiO2; it is preferable to use a homogenizer to achieve high-speed stirring.

[0065] The size of the nano-SiO2 is preferably 5-100nm, more preferably 10-50nm, and even more preferably 10-30nm.

[0066] The modified nano-SiO2 is preferably added using a blending method, comprising the following steps:

[0067] Modified nano-SiO2 was added to epoxy resin and stirred until homogeneous. The mixture was heated to 70±3℃ to remove residual acetone. After 20-30 minutes, the temperature was further increased to 100-120℃ to strengthen and stabilize the dispersion of nanoparticles.

[0068] The nano-SiO2 particles, surface-treated with silane coupling agents, possess a large number of hydroxyl groups. When added to a resin system, they form numerous associated hydrogen bonds, improving compatibility and dispersion uniformity, thus exhibiting a good toughening and reinforcing effect on epoxy systems. This is because the rigid particles at the nanoscale exhibit an alloy-like phenomenon with the resin system. Uniformly distributed nanoparticles can generate microcracks with the matrix under stress, inducing stress concentration and absorbing some energy, achieving a toughening effect. However, excessive addition of nanoparticles can have the opposite effect, causing macroscopic cracking of the microcracks. Therefore, the use of a small amount of nano-SiO2 does not significantly affect other properties of the system; its main benefit is in compensating for and optimizing the toughening shortcomings of toughened rubber in the nanoscale microenvironment.

[0069] This invention makes full use of the combination of organic and inorganic toughening agents and achieves sufficient toughening and reinforcement of the epoxy system with a reasonable material ratio. Even if the thickness of the substrate layer is very thin, it can still exhibit sufficient mechanical properties and provide stable and reliable support for the adhesive layers on both sides.

[0070] Furthermore, when the substrate layer is selected from an acrylic system, this invention provides an electrolyte-resistant double-sided tape with an acrylic ultrathin substrate, comprising, in sequence, a pressure-sensitive adhesive layer, a substrate layer, and a hot melt adhesive layer;

[0071] The substrate layer, with a thickness of 0.2-1 μm, comprises the following components by weight percentage:

[0072]

[0073]

[0074] The oligomer is an acrylate-terminated oligomer;

[0075] The diluent includes monofunctional acrylate monomers;

[0076] The crosslinking agent is an acrylate monomer with difunctionality or higher;

[0077] Pressure-sensitive adhesive layer, 3.5-6.5μm thick, comprising the following components by weight:

[0078]

[0079] The hot melt adhesive layer, with a thickness of 3.5-6.5 μm, comprises the following components by weight:

[0080]

[0081] The modified polyolefin is selected from at least one of maleic anhydride modified polyolefin and acrylic acid modified polyolefin.

[0082] The core properties of the substrate layer in acrylic systems are determined by oligomers. Oligomers refer to acrylate-terminated oligomers with a certain degree of polymerization. They include at least one of aliphatic polyacrylates, aromatic polyurethane acrylates, epoxy acrylates, polybutadiene acrylates, polyether acrylates, and polyester acrylates.

[0083] The diluent is primarily a monofunctional acrylate monomer, used to reduce the overall viscosity of the adhesive, facilitating application and wetting. It includes at least one of the following: acrylic acid, methacrylic acid, triethylene glycol ethyl ether methacrylate, alkoxydodecyl acrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, trimethylolpropane formal acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

[0084] Crosslinking agents are acrylate monomers with bifunctionality or higher, which can improve the degree of crosslinking of polymers, thereby increasing the molecular weight and properties such as solvent resistance and high temperature resistance of the material. They include at least one of the following: trimethylolpropane trimethacrylate, tri(2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tricyclodecanediethanol diacrylate, and triethylene glycol diacrylate.

[0085] The initiator is a photoinitiator, a class of compounds that can absorb energy of a certain wavelength in the ultraviolet (250–420 nm) or visible (400–800 nm) light region, generating free radicals, cations, etc., thereby initiating monomer polymerization, cross-linking, and curing. It includes at least one of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, trimethylformyl-diphenylphosphine oxide, 2-isopropylthioxanthone, and 2,4-diethylthioxanthone.

[0086] Furthermore, between the substrate layer and the pressure-sensitive adhesive layer, there is also a functional layer with a thickness of 0.2-1 μm, which, by weight, comprises the following components:

[0087]

[0088] The structural formula of polyetherimide (PEI) is as follows:

[0089]

[0090] The structural formula of thermoplastic polyimide (TPI) is as follows:

[0091]

[0092] Optionally, the conductive agent is spherical and / or flake-shaped conductive particles, wherein the conductive particles are selected from at least one of silver, nickel, micronized graphite, and carbon black, and the particle size D50 of the conductive particles is < 0.6 μm. The pigments include organic pigments and / or inorganic pigments; organic pigments include azo pigments and / or heterocyclic pigments; inorganic pigments include at least one of metal oxides, metal sulfides, metal chromates, metals, or alloys. The modified polyolefin of the functional layer has the same selection range as that of the pressure-sensitive adhesive layer and the hot melt adhesive layer.

[0093] Depending on the requirements, the functional layer can also be disposed between the substrate layer and the hot melt adhesive layer. However, when the functional layer needs to perform the function of primer adhesion, it is preferred to be placed between the substrate layer and the pressure-sensitive adhesive layer.

[0094] On the other hand, a method for preparing an electrolyte-resistant double-sided multilayer adhesive tape is provided, comprising the following steps:

[0095] S1. Hot melt adhesive layer coating:

[0096] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 10-30 wt%;

[0097] S1.2 Apply hot melt adhesive coating liquid to the release film; dry to form hot melt adhesive layer;

[0098] S2, Substrate layer coating:

[0099] S2.1 Prepare the substrate coating solution with a solid content of 4-50 wt%;

[0100] S2.2. Corona treatment of the hot melt adhesive layer in step S1.2, and coating the substrate layer coating liquid onto the corona-treated surface;

[0101] S2.3, UV pre-curing, with curing energy above 5000kJ; if using an acrylic system, N2 protection is preferred.

[0102] S2.4. Dry at 80-130℃ for 1.5-2 minutes to form a substrate layer;

[0103] S3, Pressure-sensitive adhesive layer coating:

[0104] S3.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 10-30 wt%.

[0105] S3.2. Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0106] S3.3. The pressure-sensitive adhesive coating liquid is bonded to the substrate layer of step S2.4 and dried to obtain an electrolyte-resistant double-sided multilayer tape.

[0107] Thirdly, for cases where a functional layer is provided between the substrate layer and the pressure-sensitive adhesive layer, the present invention also provides a method for preparing an electrolyte-resistant double-sided multilayer tape, comprising the following steps:

[0108] S1. Hot melt adhesive layer coating:

[0109] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 10-30 wt%;

[0110] S1.2. Apply the hot melt adhesive coating liquid onto the release film; dry to form a hot melt adhesive layer;

[0111] S2, Substrate layer coating:

[0112] S2.1 Prepare the substrate coating solution with a solid content of 4-50 wt%;

[0113] S2.2. Corona treatment of the hot melt adhesive layer in step S1.2 (preferably with an intensity of 1A to 2A), and coating the substrate layer coating liquid onto the corona-treated surface with a coating thickness of 0.2-1.0 μm;

[0114] S2.3, UV pre-curing, with curing energy above 5000kJ; if using an acrylic system, N2 protection is preferred.

[0115] S2.4. Dry at 80-130℃ for 1.5-2 minutes to form a substrate layer;

[0116] S3, Functional layer coating:

[0117] S3.1 Prepare the functional layer coating solution with a solid content of 5-30 wt%;

[0118] S3.2. Apply the functional layer coating liquid onto the substrate layer of step S2.4; dry to form the functional layer;

[0119] S4. Pressure-sensitive adhesive layer coating:

[0120] S4.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 10-30 wt%.

[0121] S4.2 Apply pressure-sensitive adhesive coating liquid to the release film;

[0122] S4.3. Apply the pressure-sensitive adhesive coating liquid to the functional layer of step S3.2; dry to obtain the electrolyte-resistant double-sided multilayer tape.

[0123] In the above preparation method, the coating method can employ common coating techniques such as gravure, slot die, and comma. The solvents for the hot melt adhesive layer, pressure-sensitive adhesive layer, and functional layer can be selected from MIBK, toluene, methylcyclohexane, xylene, etc., and the drying temperature is set within the range of 80℃ to 130℃ based on the flash point of the selected solvent. Preferably, an oven is used for drying, and the machine speed is designed according to the length of the oven to ensure that the colloid spends 1.5 to 2 minutes in the oven. For example, when the total oven length is 15m, the machine speed can be controlled at approximately 7.5 to 10m / min.

[0124] The advantages of this invention are as follows:

[0125] 1) This invention provides an electrolyte-resistant double-sided multilayer tape with an ultra-thin substrate (0.2-1μm). If it replaces 48μm double-sided PET tape, it can save at least 36μm of space, significantly increasing the battery casing volume and improving battery energy density.

[0126] 2) The use of a high-performance epoxy / acrylic substrate layer effectively prevents interference between the pressure-sensitive adhesive layer and the hot melt adhesive layer, ensuring the safety and stability of the tape during production, transportation and long-term use.

[0127] 3) This invention makes full use of the combination of organic and inorganic toughening agents and achieves full toughening and reinforcement of the epoxy system with reasonable material ratio. The extremely thin substrate layer exhibits good flexibility and elongation of up to 400%. It can absorb energy through deformation when the battery is subjected to external impact, thereby improving the battery's drop resistance performance. Attached Figure Description

[0128] Figure 1 This diagram shows the structure of the three-layer tape of the present invention;

[0129] Figure 2 This diagram shows the structure of the four-layer tape of the present invention;

[0130] Figure 3 This diagram illustrates the structure of a first embodiment of the five-layer adhesive tape of the present invention.

[0131] Figure 4 This diagram illustrates the structure of a second embodiment of the five-layer adhesive tape of the present invention.

[0132] Figure 5 A schematic diagram of the structure of the six-layer tape of the present invention is shown.

[0133] Explanation of reference numerals in the attached drawings: 1. Pressure-sensitive adhesive layer, 2. Substrate layer, 3. Hot melt adhesive layer, 4. Double-sided release film, 5. First single-sided release film, 6. Second single-sided release film, 7. Functional layer. Detailed Implementation

[0134] To make the objectives, technical solutions, and advantages of the present invention clearer, the following description will be provided in conjunction with Embodiments 1-5 and the appendix. Figure 1-5 The present invention will be described in further detail below. The selection of materials and their contents in the embodiments is only to illustrate the main concept of the present invention and is not exhaustive or limiting.

[0135] An electrolyte-resistant double-sided multilayer tape with an ultra-thin substrate, comprising a pressure-sensitive adhesive layer, a substrate layer, and a hot melt adhesive layer in sequence;

[0136] The pressure-sensitive adhesive layer, with a thickness of 3.5-6.5 μm, comprises the following components by weight:

[0137]

[0138] The α-olefin polymer is selected from at least one of polyethylene, polypropylene, amorphous polyα-olefin, and ethylene octene copolymer; the modified polyolefin is selected from at least one of maleic anhydride modified polyolefin and acrylic acid modified polyolefin; the styrene block copolymer is selected from at least one of styrene-ethylene-butadiene-styrene copolymer (SEBS) and styrene-isoprene-styrene block copolymer (SIS); the petroleum resin is selected from at least one of aliphatic resin (C5), alicyclic resin (DCPD), aromatic resin (C9), aliphatic / aromatic copolymer resin (C5 / C9), and hydrogenated petroleum resin, and the hydrogenated petroleum resin is selected from at least one of C5 hydrogenated petroleum resin and C9 hydrogenated petroleum resin; the viscosity modifier mainly includes at least one of mineral oil, liquid hydrogenated thickening resin, and liquid hydrogenated polybutadiene (PolyBD).

[0139] The substrate layer has a thickness of 0.2-1μm and can be either epoxy or acrylic.

[0140] When selecting an acrylic substrate layer, the following components are included by weight percentage:

[0141]

[0142] The oligomer is an acrylate-terminated oligomer selected from at least one of aliphatic polyacrylates, aromatic polyurethane acrylates, epoxy acrylates, polybutadiene acrylates, polyether acrylates, and polyester acrylates; the diluent includes a monofunctional acrylate monomer selected from acrylic acid, methacrylic acid, triethylene glycol ethyl ether methacrylate, alkoxydodecyl acrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, trimethylolpropane formal acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate. At least one of the following: the crosslinking agent is an acrylate monomer with difunctionality or higher, i.e., a difunctional or multifunctional acrylate monomer, selected from at least one of trimethylolpropane trimethacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tricyclodecanediethanol diacrylate, and triethylene glycol diacrylate; the initiator is a photoinitiator, selected from at least one of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, trimethylformyl-diphenylphosphine oxide, 2-isopropylthioxanone, and 2,4-diethylthioxanone.

[0143] The hot melt adhesive layer, with a thickness of 3.5-6.5 μm, comprises the following components by weight:

[0144]

[0145] The modified polyolefin is selected from at least one of maleic anhydride-modified polyolefin and acrylic acid-modified polyolefin; the styrene block copolymer includes at least one of styrene-butadiene block copolymer and styrene-isoprene block copolymer. The α-olefin polymer and petroleum resin can be selected from the same range as the pressure-sensitive adhesive layer.

[0146] The present invention includes a release film. Optionally, a first single-sided release film is provided on the outside of the pressure-sensitive adhesive layer, and the release force of the first single-sided release film on the inside of the pressure-sensitive adhesive layer is 2-8 gf / inch. A second single-sided release film is provided on the outside of the hot melt adhesive layer, and the release force of the second single-sided release film on the inside of the hot melt adhesive layer is 10-20 gf / inch.

[0147] Alternatively, a double-sided release film may be provided on the outside of the hot melt adhesive layer, with a release force of 10-20 gf / inch on the inside of the hot melt adhesive layer and a release force of 5-10 gf / inch on the outside.

[0148] The present invention further includes a functional layer with a thickness of 0.2-1 μm between the substrate layer and the pressure-sensitive adhesive layer. The functional layer comprises the following components by weight:

[0149]

[0150]

[0151] The conductive agent is spherical and / or flake-shaped conductive particles, selected from at least one of silver, nickel, micronized graphite, and carbon black, with a particle size D50 < 0.6 μm; the colorant includes organic pigments and / or inorganic pigments, with organic pigments comprising azo pigments and / or heterocyclic pigments; the inorganic pigment is selected from at least one of metal oxides, metal sulfides, metal chromates, metals, or alloys. The modified polyolefin can be selected from the same range as the other layers.

[0152] A method for preparing an electrolyte-resistant double-sided multilayer adhesive tape, preferably using a blending method to fully mix the corresponding materials to obtain coating liquids for each layer, specifically including the following steps:

[0153] S1. Hot melt adhesive layer coating:

[0154] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 10-30 wt%;

[0155] S1.2 Apply hot melt adhesive coating liquid to the release film; dry to form a hot melt adhesive layer with a thickness of 3.5-6.5μm;

[0156] S2, Substrate layer coating:

[0157] S2.1 Prepare a substrate coating liquid with a solid content of 4-50wt%, preferably 5-30wt%;

[0158] S2.2, Corona treatment of the hot melt adhesive layer in step S1.2 (intensity: 1A-2A), and coating the substrate layer coating liquid onto the corona-treated surface;

[0159] S2.3, UV light pre-curing, curing energy above 5000kJ; if the substrate layer uses an acrylic system, N2 protection is required.

[0160] S2.4. Dry at 80-130℃ for 1.5-2 minutes to form a substrate layer with a thickness of 0.2-1μm;

[0161] S3, Pressure-sensitive adhesive layer coating:

[0162] S3.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 10-30 wt%.

[0163] S3.2. Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0164] S3.3. The pressure-sensitive adhesive coating liquid is bonded to the substrate layer of step S2.4 and dried to obtain an electrolyte-resistant double-sided multilayer tape.

[0165] For cases where a functional layer is placed between a substrate layer and a pressure-sensitive adhesive layer, a method for preparing an electrolyte-resistant double-sided multilayer tape is provided, comprising the following steps:

[0166] S1. Hot melt adhesive layer coating:

[0167] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 10-30 wt%;

[0168] S1.2. Apply the hot melt adhesive coating liquid onto the release film to form a hot melt adhesive layer with a thickness of 3.5-6.5μm;

[0169] S2, Substrate layer coating:

[0170] S2.1 Prepare a substrate coating liquid with a solid content of 4-50wt%, preferably 5-30wt%;

[0171] S2.2, Corona treatment of the hot melt adhesive layer in step S1.2 (intensity: 1A-2A), and coating the substrate layer coating liquid onto the corona-treated surface;

[0172] S2.3, UV light pre-curing, curing energy above 5000kJ; if the substrate layer uses an acrylic system, N2 protection is required;

[0173] S2.4. Dry at 80-130℃ for 1.5-2 min to form a substrate layer with a thickness of 0.2-1.0μm;

[0174] S3, Functional layer coating:

[0175] S3.1 Prepare the functional layer coating solution with a solid content of 5-30 wt%;

[0176] S3.2. Apply the functional layer coating liquid onto the substrate layer of step S2.4; dry to form the functional layer;

[0177] S4. Pressure-sensitive adhesive layer coating:

[0178] S4.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 10-30 wt%.

[0179] S4.2. Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0180] S4.3. Apply the pressure-sensitive adhesive coating liquid to the functional layer of step S3.2; dry to obtain an electrolyte-resistant double-sided multilayer tape.

[0181] The coating method of this invention adopts micro-recessed coating, slot coating and / or comma coating. The solvents for the hot melt adhesive layer, pressure-sensitive adhesive layer and functional layer can be selected from MIBK, toluene, methylcyclohexane, xylene, etc. The corresponding drying temperature is set to 80℃~130℃. During the coating process of this invention, the machine speed is designed according to the length of the oven to ensure that the adhesive passes through the oven for 1.5~2 minutes.

[0182] Example 1

[0183] An electrolyte-resistant double-sided multilayer tape with an ultra-thin substrate comprises, in sequence, a pressure-sensitive adhesive layer, a functional layer, a substrate layer and a hot melt adhesive layer, with a total film thickness of 10.0 μm;

[0184] The pressure-sensitive adhesive layer, with a thickness of 5μm, comprises the following components by weight:

[0185]

[0186] The functional layer has a thickness of 0.5 μm and, by weight, comprises the following components:

[0187] PEI 40 copies

[0188] 36 parts of modified polyolefin

[0189] 24 parts of color powder.

[0190] The colorant is titanium dioxide and phthalocyanine green in a ratio of 1:2.

[0191] The epoxy substrate layer, with a thickness of 0.5 μm, comprises the following components by weight:

[0192]

[0193]

[0194] And the solvent methyl ethyl ketone (MEK), with a solid content controlled at 15%;

[0195] The hot melt adhesive layer, with a thickness of 4μm, comprises the following components by weight:

[0196]

[0197] A method for preparing an electrolyte-resistant double-sided multilayer adhesive tape includes the following steps:

[0198] S1. Hot melt adhesive layer coating:

[0199] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 20wt%;

[0200] S1.2. Apply the hot melt adhesive coating liquid onto the release film and dry it at 100°C to form a hot melt adhesive layer;

[0201] S2, Substrate layer coating:

[0202] S2.1 Prepare a substrate coating solution with a solid content of 15wt%;

[0203] S2.2. Corona treatment of the hot melt adhesive layer in step S1.2 (intensity 1.5A), and coating the substrate layer coating liquid onto the corona-treated surface;

[0204] S2.3, UV light pre-curing, curing energy at 6000kJ;

[0205] S2.4. Dry at 100℃ for 2 minutes to form a substrate layer;

[0206] S3, Functional layer coating:

[0207] S3.1 Prepare the functional layer coating solution with a solid content of 15wt%;

[0208] S3.2. Apply the functional layer coating liquid onto the substrate layer of step S2.4; dry at 100°C to form the functional layer;

[0209] S4. Pressure-sensitive adhesive layer coating:

[0210] S4.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 20wt%;

[0211] S4.2. Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0212] S4.3. Apply the pressure-sensitive adhesive coating liquid to the functional layer of step S3.2; dry at 100°C to obtain an electrolyte-resistant double-sided multilayer tape.

[0213] Example 2

[0214] An electrolyte-resistant double-sided adhesive tape with an acrylic ultrathin substrate comprises, in sequence, a pressure-sensitive adhesive layer, a functional layer, a substrate layer and a hot melt adhesive layer, with a total film thickness of 10.9 μm;

[0215] The pressure-sensitive adhesive layer, with a thickness of 6.5 μm, comprises the following components by weight:

[0216]

[0217] The functional layer has a thickness of 0.2 μm and, by weight, comprises the following components:

[0218] PEI 50 copies

[0219] 25 parts of modified polyolefin

[0220] 25 parts of coloring powder.

[0221] The colorant is a mixture of titanium dioxide and phthalocyanine green in a ratio of 1:1.5.

[0222] The acrylic substrate layer, with a thickness of 0.2 μm, comprises the following components by weight percentage:

[0223]

[0224]

[0225] The ratio of epoxy acrylate oligomer to polyurethane acrylate oligomer in the oligomer is 11:3.

[0226] The hot melt adhesive layer, with a thickness of 4μm, comprises the following components by weight:

[0227]

[0228] The preparation method of the electrolyte-resistant double-sided multilayer tape in this embodiment is basically the same as the preparation method in Example 1. The main difference is that: the corresponding coating liquid is prepared according to the material composition of each layer; and the substrate layer is protected with N2 during UV light pre-curing.

[0229] Example 3

[0230] An electrolyte-resistant double-sided adhesive tape with an acrylic ultrathin substrate comprises, in sequence, a pressure-sensitive adhesive layer, a functional layer, a substrate layer and a hot melt adhesive layer, with a total film thickness of 15.0 μm;

[0231] The pressure-sensitive adhesive layer, with a thickness of 6.5 μm, comprises the following components by weight:

[0232]

[0233] The functional layer, with a thickness of 1 μm, comprises the following components by weight:

[0234] PEI 20 copies

[0235] 60 parts of modified polyolefin

[0236] 20 parts titanium dioxide;

[0237] The acrylic substrate layer, with a thickness of 1 μm, comprises the following components by weight percentage:

[0238]

[0239] The hot melt adhesive layer, with a thickness of 6.5 μm, comprises the following components by weight:

[0240] 70 parts of α-olefin polymer

[0241] 20 parts of modified polyolefin

[0242] 10 parts of petroleum resin.

[0243] The preparation method of the electrolyte-resistant double-sided multilayer tape in this embodiment is basically the same as the preparation method in Example 2. The main difference is that the corresponding coating liquid is prepared according to the composition of each layer of material.

[0244] Example 4

[0245] An electrolyte-resistant double-sided multilayer tape with an ultra-thin substrate comprises a pressure-sensitive adhesive layer, a substrate layer, and a hot melt adhesive layer, with a total film thickness of 11.5 μm.

[0246] The pressure-sensitive adhesive layer, with a thickness of 6μm, comprises the following components by weight:

[0247]

[0248] The epoxy substrate layer, with a thickness of 0.5 μm, comprises the following components by weight:

[0249] 100 parts of bisphenol A epoxy resin

[0250] 8 parts of UV initiator

[0251] ATBN 20 copies

[0252] And the solvent methyl ethyl ketone (MEK), with a solid content controlled at 15%;

[0253] The hot melt adhesive layer, with a thickness of 5 μm, comprises the following components by weight:

[0254] 60 parts of α-olefin polymer

[0255] 30 parts of modified polyolefin

[0256] SEBS 10 copies.

[0257] The method for preparing electrolyte-resistant double-sided multilayer adhesive tape in this embodiment includes the following steps:

[0258] S1. Hot melt adhesive layer coating:

[0259] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 20wt%;

[0260] S1.2 Apply hot melt adhesive coating liquid to the release film; dry at 100℃ to form a hot melt adhesive layer with a thickness of 4μm;

[0261] S2, Substrate layer coating:

[0262] S2.1 Prepare a substrate coating solution with a solid content of 15wt%;

[0263] S2.2. Corona treatment of the hot melt adhesive layer in step S1.2 (strength 1.5A), and coating the substrate layer coating liquid onto the corona-treated surface;

[0264] S2.3, UV light pre-curing, curing energy at 6000kJ;

[0265] S2.4. Dry at 100℃ for 2 minutes to form a substrate layer with a thickness of 0.5μm;

[0266] S3, Pressure-sensitive adhesive layer coating:

[0267] S3.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 20wt%;

[0268] S3.2. Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0269] S3.3. The pressure-sensitive adhesive coating liquid is bonded to the substrate layer of step S2.4 and dried at 100°C to obtain an electrolyte-resistant double-sided multilayer tape.

[0270] Example 5

[0271] The main difference between this embodiment and Embodiment 4 is that the substrate layer also contains 1 part by weight of modified nano-SiO2, specifically:

[0272] The epoxy substrate layer, with a thickness of 0.5 μm, comprises the following components by weight:

[0273]

[0274] And the solvent methyl ethyl ketone (MEK), with a solid content controlled at 15%;

[0275] Preparation of modified nano-SiO2:

[0276] Step 1: Dilute KH550 with acetone. The amount of KH550 used is 1% of the weight of nano-SiO2.

[0277] Step 2: Add nano-SiO2 (particle size approximately 10-30 nm) and heat the mixture to 100°C, stirring for 30 minutes to obtain modified nano-SiO2.

[0278] Modified nano-SiO2 was added to epoxy resin and stirred until homogeneous. The mixture was then heated to 70±3℃ to remove residual acetone. After 30 minutes, the temperature was further increased to 110℃ to strengthen and stabilize the dispersion of the nanoparticles. Subsequently, it was blended with other materials to prepare the substrate coating solution.

[0279] Comparative Example 1

[0280] The difference between Comparative Example 1 and Example 4 is that the double-sided multilayer tape of Comparative Example 1 does not have a substrate layer, and the total thickness of the adhesive film is 11.0 μm, including: a pressure-sensitive adhesive layer with a thickness of 6 μm; and a hot melt adhesive layer with a thickness of 5 μm.

[0281] The preparation method of the double-sided multilayer adhesive tape of Comparative Example 1 includes the following steps:

[0282] S1. Hot melt adhesive layer coating:

[0283] S1.1 Prepare a hot melt adhesive coating liquid with a solid content of 20wt%;

[0284] S1.2 Apply hot melt adhesive coating liquid to the release film; dry at 100℃ to form a hot melt adhesive layer with a thickness of 5μm;

[0285] S2, Pressure-sensitive adhesive layer coating:

[0286] S2.1 Prepare a pressure-sensitive adhesive coating solution with a solid content of 20wt%;

[0287] S2.2, Apply the pressure-sensitive adhesive coating liquid onto the release film;

[0288] S2.3. Apply the pressure-sensitive adhesive coating liquid to the hot melt adhesive layer of step S1.2 and dry at 100°C to obtain a double-sided multilayer tape.

[0289] Comparative Example 2

[0290] Comparative Example 2 is the Nitto 5000NS product, with a thickness of 160.0 μm.

[0291] Table 1 summarizes the material composition and sources of Examples 1-5 and Comparative Examples 1-2.

[0292] Table 1. Material composition of Examples 1-5 and Comparative Examples 1-2

[0293]

[0294]

[0295]

[0296] Test methods

[0297] I. Initial peel force of pressure-sensitive layer

[0298] 1) Peel off the release film on the pressure-sensitive surface and attach it to the steel plate;

[0299] 2) Roll the adhesive film with a 2kg roller three times, cure at room temperature for 20 minutes, and then peel off the release film of the hot melt adhesive layer;

[0300] 3) Apply special adhesive tape (T4150BR) to the hot melt adhesive layer;

[0301] 4) Test peel strength at a rate of 300 mm / min. National Standard GB / T 2792-2014;

[0302] Note: The hot melt adhesive layer of this invention has low polarity, and ordinary tapes cannot exert adhesive force on it. Therefore, it is necessary to test the peel strength by bonding it with a special T4150BR tape with low surface energy.

[0303] II. Initial peel force of hot melt adhesive layer (requirement ≤ 5 N / m)

[0304] 1) Peel off the release film on one side of the hot melt adhesive layer and attach it to the steel plate;

[0305] 2) A 2kg roller presses the film back and forth 3 times;

[0306] 3) Test peel strength at a rate of 300 mm / min. National Standard GB / T 2792-2014;

[0307] III. Peel strength after immersion in electrolyte

[0308] 1) Peel off the release film on the pressure-sensitive side of the adhesive film and attach the aluminum foil:

[0309] 2) Roll the adhesive film with a 2kg roller three times, cure at room temperature for 20 minutes, and then peel off the release film of the hot melt adhesive layer;

[0310] 3) Cut the sample into 20mm*100mm strips, immerse them in electrolyte (EC / PC / DEC / EP = 3:3:1:3, and 1mol / L LiPF6), and age at 85℃ for 4 hours;

[0311] 4) After allowing the electrolyte to evaporate at room temperature for 30 minutes, attach it to the inside of the aluminum-plastic film (CPP side);

[0312] 5) Use a hot press, press at 85℃ and 1MPa for 38 minutes;

[0313] 6) Test peel strength at a rate of 50 mm / min.

[0314] IV. Interference Properties of the Coating Film

[0315] 1) Store the film at 25°C for 30 days or at 60°C for 24 hours;

[0316] 2) Test the initial peel force of the pressure-sensitive layer and the hot melt adhesive layer according to the method described above.

[0317] V. Dissolution rate

[0318] 1) Fold the film repeatedly until the film weighs about 5g;

[0319] 2) Use a hot melt machine to hot press the repeatedly folded adhesive film at 100℃ and 1MPa for 5 minutes to completely melt it into a single piece;

[0320] 3) Cut it into 2g pieces and weigh them as M1;

[0321] 4) Soak the gel block in about 30g of electrolyte (EC / PC / DEC / EP = 3:3:1:3, and 1mol / L LiPF6);

[0322] Aging conditions: 85℃ for 24 hours;

[0323] 5) Prepare a clean beaker, weigh M2, pour the electrolyte that has soaked the gel block into the beaker, 12

[0324] Bake at ℃ for 4 hours

[0325] 6) Re-weigh the beaker, M3;

[0326] Calculate the dissolution rate: (M3-M2)*100 / M1.

[0327] The above tests were performed on Examples 1-5 and Comparative Examples 1-2, and the results are shown in Table 2.

[0328] Table 2 Test results of Examples 1-5 and Comparative Examples 1-2

[0329]

[0330]

[0331] The results above show that:

[0332] In Comparative Example 1, which lacks both a substrate layer and a functional layer, even though it has good electrolyte resistance, after long-term storage, the adhesives on both sides show significant mutual leakage, causing mutual interference in performance and rendering it unusable.

[0333] As can be seen from Comparative Example 2, even though its initial peel strength is very high, the peel strength is severely weakened after immersion in electrolyte, making it unusable in batteries.

[0334] Examples 1-5 of this invention all have a thickness ≤15μm, exhibit high peel strength after immersion in electrolyte, and low dissolution rate. They are highly suitable for use in pouch batteries, especially in fast-charging systems. They possess significant commercial potential and application value.

[0335] The preferred embodiments of the present invention have been described above to make the spirit of the present invention clearer and easier to understand, and are not intended to limit the present invention. All modifications, substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope summarized by the appended claims.

Claims

1. An electrolyte-resistant double-coated adhesive tape having an acrylic ultrathin substrate, characterized by, The pressure-sensitive adhesive layer, the substrate layer and the hot melt adhesive layer are sequentially arranged. The substrate layer has a thickness of 0.2-1 μm and comprises the following components by weight percentage: The oligomer is an acrylate-terminated oligomer. The diluent comprises a monofunctional acrylate monomer. The crosslinking agent is a multifunctional acrylate monomer. The pressure-sensitive adhesive layer has a thickness of 3.5-6.5 μm and comprises the following components by weight percentage: The hot melt adhesive layer has a thickness of 3.5-6.5 μm and comprises the following components by weight percentage: The modified polyolefin is selected from at least one of maleic anhydride modified polyolefin and acrylic modified polyolefin; the α-olefin polymer is selected from at least one of polyethylene, polypropylene, amorphous poly-α-olefin and ethylene octene copolymer; and the styrene block copolymer comprises at least one of block copolymer of styrene and butadiene and block copolymer of styrene and isoprene.

2. The electrolyte-resistant double-coated tape according to claim 1, wherein The oligomer comprises at least one of aliphatic polyacrylate, aromatic polyurethane acrylate, epoxy acrylate, polybutadiene acrylate, polyether acrylate and polyester acrylate.

3. The electrolyte-resistant double-coated tape according to claim 2, wherein The diluent comprises at least one of acrylic acid, methacrylic acid, triethylene glycol ethyl ether methacrylate, alkoxy dodecyl acrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, trimethylolpropane formal acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate.

4. The electrolyte-resistant double-coated tape of claim 2, wherein The crosslinking agent comprises at least one of trimethylolpropane trimethacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate and tricyclodecane dimethanol diacrylate.

5. The electrolytic solution-resistant double-coated tape according to claim 2, wherein The initiator is a photoinitiator and comprises at least one of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, trimethyl benzoyl-diphenyl phosphine oxide, 2-isopropyl thioxanthone and 2,4-diethyl thioxanthone.

6. The electrolyte-resistant double-coated adhesive tape according to any one of claims 1 to 5, wherein The electrolyte-resistant double-sided multi-layer adhesive tape further comprises: a first single-sided release film arranged on the outside of the pressure-sensitive adhesive layer and a second single-sided release film arranged on the outside of the hot melt adhesive layer, the inside of the first single-sided release film facing the pressure-sensitive adhesive layer has a release force of 2-8 gf / inch, and the inside of the second single-sided release film facing the hot melt adhesive layer has a release force of 10-20 gf / inch; or a double-sided release film arranged on the outside of the hot melt adhesive layer, the inside of the double-sided release film facing the hot melt adhesive layer has a release force of 10-20 gf / inch, and the outside has a release force of 5-10 gf / inch.

7. The electrolyte-resistant double-sided adhesive tape according to any one of claims 1-5, further comprising a functional layer having a thickness of 0.2-1 μm between the substrate layer and the pressure-sensitive adhesive layer, the functional layer comprising the following components by weight percentage: The conductive agent has a particle size D50 of less than 0.6 μm and is selected from at least one of silver, nickel, micro-powder graphite and carbon black.

8. A process for producing the electrolyte-resistant double-coated adhesive tape according to any one of claims 1 to 6, characterized by, The method comprises the following steps: S1, hot melt adhesive layer coating: S1.1, configure hot melt adhesive layer coating liquid, solid content 10-30wt%; S1.2, coating the hot melt adhesive layer coating liquid on the release film; drying, forming a hot melt adhesive layer; S2, substrate layer coating: S2.1, configure substrate layer coating liquid, solid content 4-50wt%; S2.2, corona treatment of the hot melt adhesive layer of step S1.2, coating the substrate layer coating liquid on the corona treatment surface; S2.3, UV light pre-curing under N2 protection, curing energy above 5000kJ; S2.4, drying at 80-130℃, 1.5-2min, forming a substrate layer; S3, pressure sensitive adhesive layer coating: S3.1, configure pressure sensitive adhesive layer coating liquid, solid content 10-30wt%; S3.2, coating the pressure sensitive adhesive layer coating liquid on the release film; S3.3, laminating the pressure sensitive adhesive layer coating liquid with the substrate layer of step S2.4, drying, obtaining the electrolyte-resistant double-sided multilayer adhesive tape.

9. A method of producing the electrolytic solution-resistant double-coated tape according to claim 7, characterized by, The method comprises the following steps: S1, hot melt adhesive layer coating: S1.1, configure hot melt adhesive layer coating liquid, solid content 10-30wt%; S1.2, coating the hot melt adhesive layer coating liquid on the release film; drying, forming a hot melt adhesive layer; S2, substrate layer coating: S2.1, configure substrate layer coating liquid, solid content 4-50wt%; S2.2, corona treatment of the hot melt adhesive layer of step S1.2, coating the substrate layer coating liquid on the corona treatment surface; S2.3, UV light pre-curing under N2 protection, curing energy above 5000kJ; S2.4, drying at 80-130℃, 1.5-2min, forming a substrate layer; S3, functional layer coating: S3.1, configure functional layer coating liquid, solid content 5-30wt%; S3.2, coating the functional layer coating liquid on the substrate layer of step S2.4; drying, forming a functional layer; S4, pressure sensitive adhesive layer coating: S4.1, configure pressure sensitive adhesive layer coating liquid, solid content 10-30wt%; S4.2, coating the pressure sensitive adhesive layer coating liquid on the release film; S4.3, laminating the pressure sensitive adhesive layer coating liquid with the functional layer of step S3.2; Drying, obtaining the electrolyte-resistant double-sided multilayer adhesive tape.

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