High temperature electrolyte resistant acrylic pressure-sensitive adhesive, swelling tape and preparation method thereof

Abstract

The invention relates to a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, a swelling tape and a preparation method thereof. The high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive comprises an acrylic polymer, which is made of raw materials containing the following components in parts by weight: 20 to 40 parts of a long-chain acrylic monomer; 3 to 10 parts of a long-chain methacrylate monomer; 1.0 to 3.0 parts of an acrylic functional monomer; 0 to 1.5 parts of a methacrylic functional monomer; 3 to 12 parts of a hard monomer; 0 to 6 parts of a SIS elastomer; 0.1 to 1.0 parts of an initiator; and 48 to 56 parts of a first solvent. The high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive can be used to make a swelling tape, which is suitable for lithium-ion batteries. After the swelling tape absorbs electrolyte, it expands to fill the gap between the battery core and the shell inside the battery, and at the same time has viscosity and is fixed in the gap position without relative displacement, thereby eliminating safety hazards of the battery during use, especially under harsh working conditions.

Description

Technical Field

[0001] The invention relates to the field of pressure-sensitive adhesives, and in particular to a high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive, a swelling adhesive tape and a preparation method thereof. Background Art

[0002] In recent years, with the development and growth of the new energy industry, the lithium-ion battery industry has achieved rapid development. Lithium batteries have not only achieved qualitative breakthroughs in performance, but also rapidly reduced costs, thus continuing to promote the development of the lithium-ion battery industry. At present, the mainstream products in the lithium-ion battery industry are basically liquid electrolyte batteries. In the manufacturing process of lithium-ion batteries, a certain gap is reserved between the battery cell and the shell in order to smoothly install the battery cell into the shell during assembly. Generally, the gap is within 200μm. Due to the existence of this gap, the battery cell and the shell will move relative to each other during use, especially under harsh working conditions, resulting in safety issues such as battery short circuit, increased internal resistance of the battery, and heat generation.

[0003] In order to solve the above problems, swelling tape came into being. Swelling tape is a special swelling substrate coated with pressure-sensitive adhesive used for lithium battery cells and shell internal winding tape. It has excellent adhesion, expansion, filling, and good process operability. The swelling tapes currently used in the market mainly include PS (polystyrene), TPU (thermoplastic polyurethane), and EVA (ethylene-vinyl acetate polymer), each with its own advantages and disadvantages. For example, the PS substrate has good swelling properties, but its high temperature resistance is average, and it will shrink at around 50°C; although the TPU substrate has good temperature resistance, it will melt into a paste when immersed in the electrolyte, affecting its use; although the EVA substrate performs well in temperature resistance and electrolyte immersion, due to its low surface energy, the subsequent bonding with the pressure-sensitive adhesive layer is weak, and the adhesive layer and the substrate are easily separated. Summary of the invention

[0004] In view of the deficiencies of the prior art, the first object of the present invention is to provide a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, which has good high-temperature electrolyte resistance, as well as good viscosity and coating properties.

[0005] The second object of the present invention is to provide a method for preparing the high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, which can obtain an acrylic pressure-sensitive adhesive with good performance.

[0006] The third object of the present invention is to provide a swelling tape prepared from the above-mentioned high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, which expands after absorbing electrolyte, can withstand electrolyte under high-temperature working conditions, has good adhesion, and does not cause relative displacement during use.

[0007] A fourth object of the present invention is to provide a method for preparing the swelling tape, which has the advantages of simple steps and the like.

[0008] The fifth object of the present invention is to provide an application of the swelling tape, and to use the container silicone tape for batteries to eliminate safety hazards of the batteries during use, especially under harsh working conditions.

[0009] To achieve the first purpose of the present invention, the present invention provides a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, which includes an acrylic polymer, and the acrylic polymer is made of a raw material containing the following components in parts by weight: 20 to 40 parts of a long-chain acrylic monomer; 3 to 10 parts of a long-chain methacrylate monomer; 1.0 to 3.0 parts of an acrylic functional monomer; 0 to 1.5 parts of a methacrylic functional monomer; 3 to 12 parts of a hard monomer; 0 to 6 parts of a SIS elastomer; 0.1 to 1.0 parts of an initiator; and 48 to 56 parts of a first solvent.

[0010] In some embodiments of the present invention, the long-chain acrylate monomer includes one or more of isooctyl acrylate, lauryl acrylate, isobornyl acrylate, and octadecyl acrylate.

[0011] In some embodiments of the present invention, the long-chain acrylate monomer is a mixture of isooctyl acrylate and one or more of lauryl acrylate, isobornyl acrylate, and octadecyl acrylate, and the amount of isooctyl acrylate accounts for 60-70% of the total amount of the long-chain acrylate monomer.

[0012] In some embodiments of the present invention, the long-chain acrylate monomer is a mixture of isooctyl acrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of isooctyl acrylate, lauryl acrylate and isobornyl acrylate is 20:(3-10):(3-10).

[0013] In some embodiments of the present invention, the long-chain methacrylate monomer includes one or more of isooctyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and octadecyl methacrylate.

[0014] In some embodiments of the present invention, the acrylic functional monomer includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, and acrylamide.

[0015] In some embodiments of the present invention, the acrylic acid functional monomer is a mixture of acrylic acid and one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and acrylamide, and the amount of acrylic acid accounts for 50-85% of the total amount of acrylic acid functional monomers.

[0016] In some embodiments of the present invention, the hard monomer is one or more of methyl methacrylate, methyl acrylate, styrene, and vinyl acetate.

[0017] In some embodiments of the present invention, the weight portion of the methacrylic acid functional monomer is 0.6 to 1.5 parts.

[0018] In some embodiments of the present invention, the methacrylic acid functional monomer includes one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, and methacrylic acid.

[0019] In some embodiments of the present invention, the methacrylic acid functional monomer is a mixture of methacrylic acid and one or both of hydroxyethyl methacrylate and hydroxypropyl methacrylate, and the amount of methacrylic acid accounts for 70-80% of the total amount of the methacrylic acid functional monomer.

[0020] In some embodiments of the present invention, the weight parts of SIS elastomer is 2 to 6 parts.

[0021] In some embodiments of the present invention, the SIS elastomer is a thermoplastic elastomer obtained by anionic polymerization. Preferably, the SIS elastomer is one or more of the products of model SIS1105, SIS1106, SIS1209, SIS11026, SIS4019, SIS1124, and SIS1126 produced by Baling Petrochemical Co., Ltd.

[0022] In some embodiments of the present invention, the initiator includes one or more of azobisisobutyronitrile, dibenzoyl peroxide, and cumene peroxide.

[0023] In some embodiments of the present invention, the initiator is a mixture of azobisisobutyronitrile and one or two of dibenzoyl peroxide and cumene peroxide, and the amount of azobisisobutyronitrile accounts for 20-70% of the total amount of the initiator.

[0024] In some embodiments of the present invention, the first solvent includes one or more of ethyl acetate, toluene, and xylene.

[0025] In some embodiments of the present invention, the solid content of the acrylic ester polymer is 44-52%, the viscosity is 4000-8000 CPS, and the weight average molecular weight Mw is 600,000-1.2 million.

[0026] In some embodiments of the present invention, the high temperature electrolyte resistant acrylate pressure sensitive adhesive further includes a curing agent and a second solvent, and the mass ratio of the acrylate polymer, the curing agent and the second solvent is 80: (0.5-2.5): (10-20).

[0027] In some embodiments of the present invention, the curing agent includes one or both of an isocyanate curing agent and an epoxy curing agent; the isocyanate curing agent is hexamethylene diisocyanate biuret, and the epoxy curing agent is a tetrafunctional epoxy curing agent.

[0028] In some embodiments of the present invention, the second solvent includes one or more of ethyl acetate, toluene, and xylene.

[0029] To achieve the second purpose of the present invention, the present invention provides a method for preparing a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, which comprises the following steps: step 1: adding the first part of the first solvent, the first part of the long-chain acrylic ester monomer, the first part of the long-chain methacrylic ester monomer, the acrylic functional monomer, the methacrylic functional monomer, the hard monomer, and the SIS elastomer to a reactor, and stirring and mixing them evenly; mixing the second part of the first solvent and the first part of the initiator, and dropping them into the reactor to react; step 2: mixing the second part of the long-chain acrylic ester monomer and the second part of the long-chain methacrylic ester monomer and dropping them into the reactor, mixing the third part of the first solvent and the second part of the initiator and dropping them into the reactor, and reacting at a heat preservation temperature; mixing the fourth part of the first solvent and the third part of the initiator, adding them to the reactor, and reacting at a heat preservation temperature; step 3: adding the fifth part of the first solvent into the reactor for dilution to obtain an acrylic ester polymer.

[0030] In some embodiments of the present invention, in step 1, adding the mixture of the second part of the first solvent and the first part of the initiator dropwise into the reaction kettle is carried out in an inert gas atmosphere; the reaction temperature is 80-83° C., and the reaction time is 1-2 h.

[0031] In some embodiments of the present invention, in step 2, the second part of the long-chain acrylate monomer and the second part of the long-chain methacrylate monomer are mixed and added dropwise to the reactor, and the third part of the first solvent and the second part of the initiator are mixed and added dropwise to the reactor for 1 to 1.5 hours, and then kept warm for reaction for 2.5 to 3.5 hours; the fourth part of the first solvent and the third part of the initiator are mixed, added to the reactor and kept warm for 3 to 5 hours.

[0032] In some embodiments of the present invention, after step three, step four is further included: uniformly stirring the acrylate polymer obtained in step three with the curing agent and the second solvent to obtain a high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive.

[0033] In order to achieve the third purpose of the present invention, the present invention also provides a swelling tape, which includes a swelling substrate layer and a pressure-sensitive adhesive layer arranged on the swelling substrate layer, and the pressure-sensitive adhesive layer is made of the high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive described in any of the above schemes or the high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive obtained by the preparation method described in any of the above schemes.

[0034] In some embodiments of the present invention, the swelling substrate layer includes a polyester polyurethane swelling material.

[0035] In some embodiments of the present invention, the thickness of the pressure-sensitive adhesive layer is 5 to 15 μm, preferably 5 to 10 μm.

[0036] In some embodiments of the present invention, the thickness of the swelling substrate layer is 15 to 60 μm, preferably 20 to 50 μm.

[0037] To achieve the fourth purpose of the present invention, the present invention also provides a method for preparing the above-mentioned swelling tape, which comprises the following steps: coating a high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive on a release film, and drying and curing the pressure-sensitive adhesive to form a pressure-sensitive adhesive layer; compounding the pressure-sensitive adhesive layer to a swelling substrate layer; and peeling off the release film.

[0038] To achieve the fifth purpose of the present invention, the present invention also provides a battery, comprising a shell and a battery cell located in the shell, with a gap between the battery cell and the shell, and also comprising the swelling tape described in any of the above schemes or the swelling tape prepared by the preparation method described in any of the above schemes, the swelling tape being immersed in the electrolyte in the gap and expanding to fill the gap.

[0039] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0040] The high-temperature electrolyte-resistant pressure-sensitive adhesive provided by the present invention is selected from long-chain acrylate monomers, long-chain methacrylate monomers, acrylic functional monomers and hard monomers, and has excellent electrolyte resistance, suitable peeling force performance, is not dissolved by electrolyte, and can still maintain a certain degree of adhesion when immersed in electrolyte, especially at high temperature. It has excellent electrolyte resistance and meets the operating conditions of power lithium batteries. The swelling tape provided by the present invention is fixed in the position of the gap between the battery core and the shell without relative displacement. At the same time, the swelling substrate can absorb part of the electrolyte, reduce the direct contact of the electrolyte with the inside of the shell, slow down the corrosion process of the shell, reduce the risk of safety problems such as battery short circuit, increased internal resistance of the battery, and heat, and improve safety. DETAILED DESCRIPTION

[0041] The embodiment of the present invention provides a high temperature electrolyte resistant acrylic pressure sensitive adhesive, which can have good electrolyte resistance under high temperature working conditions, has strong adhesion to the swelling substrate, and has suitable viscosity, which is easy to operate and process. The high temperature electrolyte resistant acrylic pressure sensitive adhesive can be used to make swelling tape for liquid electrolyte batteries to improve the safety of battery use.

[0042] Specifically, the high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive includes an acrylic polymer, which is made of a raw material containing the following components in parts by weight: 20 to 40 parts of a long-chain acrylic monomer; 3 to 10 parts of a long-chain methacrylate monomer; 1.0 to 3.0 parts of an acrylic functional monomer; 0 to 1.5 parts of a methacrylic functional monomer; 3 to 12 parts of a hard monomer; 0 to 6 parts of a SIS elastomer; 0.1 to 1.0 parts of an initiator; and 48 to 56 parts of a first solvent.

[0043] The acrylic polymer in the high temperature electrolyte resistant pressure sensitive adhesive prepared in this embodiment uses long chain acrylic ester monomers, long chain methacrylic ester monomers, acrylic functional monomers and hard monomers to obtain an acrylic pressure sensitive adhesive with excellent electrolyte resistance. The long chain acrylic ester monomer is used as the main monomer. The long chain acrylic ester polymer is insoluble in solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) in the electrolyte due to its long chain ester structure. A certain proportion of long-chain methacrylate monomers is added to enhance the steric hindrance effect of the molecular chain, and acrylic acid functional monomers are added to introduce active hydrogen functional groups, which can not only improve the adhesion of the high-temperature electrolyte-resistant pressure-sensitive adhesive, but also further improve the temperature resistance and electrolyte resistance of the pressure-sensitive adhesive through cross-linking reactions. The final product has excellent electrolyte resistance and suitable peeling force performance under high temperature conditions, is not dissolved by the electrolyte, and can still maintain a certain adhesion when immersed in the electrolyte, especially has excellent electrolyte resistance at high temperatures, which meets the operating conditions of power lithium batteries.

[0044] In some embodiments, the raw material of the acrylic ester polymer in the high temperature electrolyte resistant acrylic ester pressure sensitive adhesive is composed of the following components: 20 to 40 parts of long chain acrylic ester monomer; 3 to 10 parts of long chain methacrylic ester monomer; 1.0 to 3.0 parts of acrylic functional monomer; 0 to 1.5 parts of methacrylic functional monomer; 3 to 12 parts of hard monomer; 0 to 6 parts of SIS elastomer; 0.1 to 1.0 parts of initiator; 48 to 56 parts of the first solvent. The raw material of the acrylic ester polymer does not contain other components except the above components, and the composition is simpler, which further reduces the cost.

[0045] In some embodiments, in the raw materials of the acrylate polymer of the high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive, the sum of the weight parts of the long-chain acrylate monomer, the long-chain methacrylate monomer, the acrylic functional monomer, the methacrylic functional monomer, the hard monomer, the SIS elastomer, the initiator and the first solvent is 100 parts, which is convenient for coordinating the dosage of each component.

[0046] In some embodiments, in the raw material of the acrylate polymer of the high temperature electrolyte resistant acrylate pressure sensitive adhesive, the weight proportion of the long chain acrylate monomer can be 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 parts, etc.; the weight proportion of the long chain methacrylate monomer can be 3, 4, 5, 6, 7, 8, 9, 10 parts, etc.; the weight proportion of the acrylic acid functional monomer can be 1, 1.5, 2, 2.5, 3 parts, etc.; the weight proportion of the methacrylic acid functional monomer can be 0, 0.1, 0.2, 0.3, etc. , 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5 parts etc.; the weight parts of the hard monomer can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 parts etc.; the weight parts of the SIS elastomer can be 0, 1, 2, 3, 4, 5, 6 parts etc.; the weight parts of the initiator can be 0.1, 0.12, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 parts etc.; the weight parts of the first solvent can be 48, 49, 50, 51, 52, 53, 54, 55, 56 parts etc.

[0047] In some embodiments, the long-chain acrylate monomer includes one or more of isooctyl acrylate, lauryl acrylate, isobornyl acrylate, and octadecyl acrylate. The above acrylate monomers have long alkyl chains and can improve the solvent resistance and electrolyte resistance of the acrylate polymer.

[0048] In some embodiments, the long-chain acrylate monomer is preferably a mixture of isooctyl acrylate and one or more of lauryl acrylate, isobornyl acrylate, and octadecyl acrylate, which further improves the performance of the high-temperature electrolyte-resistant pressure-sensitive adhesive. The amount of isooctyl acrylate can account for 60-70% of the total amount of the long-chain acrylate monomer, such as 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc.

[0049] In some embodiments, the long-chain acrylate monomer is more preferably a mixture of isooctyl acrylate, lauryl acrylate and isobornyl acrylate to further improve the adhesion of the high-temperature electrolytic resistant pressure sensitive adhesive. The weight ratio of isooctyl acrylate, lauryl acrylate and isobornyl acrylate can be 20:(3~10):(3~10), for example, 20:3:10, 20:5:5, 20:10:3, etc.

[0050] In some embodiments, the long-chain methacrylate monomer includes one or more of isooctyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and octadecyl methacrylate. The above monomers have long-chain alkyl groups that can improve the solvent resistance and electrolyte resistance of the acrylate polymer. They also have methyl groups that can increase the steric hindrance of the polymer, improve temperature resistance, and facilitate subsequent crosslinking.

[0051] In some embodiments, the acrylic functional monomer includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, and acrylamide. The acrylic functional monomer has a carboxyl group or a hydroxyl group, which can improve the adhesion of the polymer and facilitate the subsequent cross-linking and curing of the polymer.

[0052] In some embodiments, the acrylic acid functional monomer is preferably a mixture of acrylic acid and one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and acrylamide, which further improves the performance of the high-temperature electrolyte-resistant pressure-sensitive adhesive. The amount of acrylic acid accounts for 50-85% of the total amount of acrylic acid functional monomers, such as 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, etc.

[0053] In some embodiments, the hard monomer is one or more of methyl methacrylate, methyl acrylate, styrene, and vinyl acetate. The molecular chain segments formed by the above monomers are relatively hard and have low creep properties, which can improve the mechanical strength of the polymer.

[0054] In some embodiments, the weight of the methacrylic acid functional monomer is 0.6 to 1.5 parts. The methacrylic acid functional monomer can also enhance the steric hindrance effect of the molecular chain, and the methacrylic acid functional monomer can adjust the molecular structure of the cross-linking density of the pressure-sensitive adhesive, thereby enhancing the temperature resistance of the acrylic pressure-sensitive adhesive.

[0055] In some embodiments, the methacrylic acid functional monomer includes one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, and methacrylic acid. The methacrylic acid functional monomer has a hydroxyl group or a carboxyl group, which can improve the adhesion and crosslinking density of the pressure-sensitive adhesive.

[0056] In some embodiments, the methacrylic acid functional monomer is preferably a mixture of methacrylic acid and one or both of hydroxyethyl methacrylate and hydroxypropyl methacrylate, so as to further adjust the crosslinking degree of the polymer. The amount of methacrylic acid can account for 70-80% of the total amount of methacrylic acid functional monomers, such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.

[0057] In some embodiments, the weight of the SIS elastomer is 2 to 6 parts. The SIS elastomer is styrene-isoprene-styrene elastomer, which has high flexibility and electrolyte resistance, and has unsaturated double bonds, which can be grafted onto the polymer chain to increase the electrolyte resistance and adhesion of the product. When the amount of the SIS elastomer is within the above range, the electrolyte resistance of the product can be significantly increased, and the pressure-sensitive adhesive viscosity is prevented from being too high to affect the coating.

[0058] In some embodiments, the SIS elastomer is a thermoplastic elastomer obtained by anionic polymerization, has a narrow molecular weight distribution, and has a better effect on improving the properties of the polymer.

[0059] In some embodiments, the SIS elastomer is preferably one or more of the products of model SIS1105, SIS1106, SIS1209, SIS11026, SIS4019, SIS1124, and SIS1126 produced by Baling Petrochemical Co., Ltd. The above raw materials are easily purchased.

[0060] In some embodiments, the initiator includes one or more of azobisisobutyronitrile, dibenzoyl peroxide, and cumene peroxide. The free radical initiator can initiate polymerization of the monomer under heating conditions.

[0061] In some embodiments, the initiator is preferably a mixture of azobisisobutyronitrile and one or both of dibenzoyl peroxide and cumene peroxide. The use of different types of initiators can make the polymerization reaction more complete. The amount of azobisisobutyronitrile can account for 20% to 70% of the total amount of initiator, such as 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.

[0062] In some embodiments, the first solvent includes one or more of ethyl acetate, toluene, and xylene, and the above solvents have good solubility for raw materials such as monomers and initiators.

[0063] In some embodiments, the solid content of the acrylate polymer is 44-52%, and the acrylate polymer itself exists in the form of a solution. The viscosity of the acrylate polymer is 4000-8000 CPS, and the weight average molecular weight Mw is 600,000-1.2 million, which is convenient for coating and processing, and has good mechanical properties.

[0064] In some embodiments, the high temperature electrolyte resistant acrylic pressure sensitive adhesive further includes a curing agent and a second solvent. The curing agent is used to further improve the crosslinking degree of the pressure sensitive adhesive, and the second solvent is used to adjust the viscosity of the pressure sensitive adhesive. The mass ratio of the acrylic polymer, the curing agent, and the second solvent can be 80: (0.5-2.5): (10-20), for example, 80: 2: 15, 80: 1, 5: 15, etc.

[0065] In some embodiments, the curing agent includes one or both of an isocyanate curing agent and an epoxy curing agent. Isocyanates and epoxy compounds can react with active hydrogen to achieve crosslinking of polymers, and have the advantages of fast reaction speed and sufficient reaction. In some embodiments, the isocyanate curing agent is hexamethylene diisocyanate biuret, and the epoxy curing agent is a tetrafunctional epoxy curing agent.

[0066] In some embodiments, the second solvent includes one or more of ethyl acetate, toluene, and xylene, and the above solvents have good solubility for acrylate polymers, curing agents, and the like.

[0067] This embodiment also provides a method for preparing a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive, including the preparation of an acrylic polymer: adding a proportion of a long-chain acrylic monomer, a long-chain methacrylic monomer, an acrylic functional monomer, a methacrylic functional monomer, a hard monomer, a SIS elastomer and a proportion of a first initiator solution into a reactor, adding a portion of a proportion of a first solvent, reacting at 80-83°C for 1.5 hours, dripping a proportion of a second initiator and a proportion of a monomer solution, the dripping time is 1 hour, then keeping warm for 3 hours, adding a proportion of a third initiator solution, keeping warm for 3-5 hours after the reaction is complete, and diluting the remaining proportion of the first solvent to a solid content of 44-52% to obtain an acrylic polymer. It can also include the preparation of a pressure-sensitive adhesive: stirring the prepared acrylic polymer, curing agent, and second solvent evenly to obtain a coated finished pressure-sensitive adhesive.

[0068] In some embodiments, the method for preparing the high temperature electrolyte resistant acrylic pressure sensitive adhesive of this embodiment may include the following steps:

[0069] Step 1: Add the first part of the first solvent, the first part of the long-chain acrylate monomer, the first part of the long-chain methacrylate monomer, the acrylic functional monomer, the methacrylic functional monomer, the hard monomer, and the SIS elastomer into the reactor, and stir and mix them evenly; mix the second part of the first solvent and the first part of the initiator, and add them dropwise into the reactor to react;

[0070] Step 2: Mix the second part of the long-chain acrylate monomer and the second part of the long-chain methacrylate monomer and drop them into the reactor; mix the third part of the first solvent and the second part of the initiator and drop them into the reactor, and keep the temperature for reaction; mix the fourth part of the first solvent and the third part of the initiator, add them into the reactor, and keep the temperature for reaction;

[0071] Step 3: Add the fifth portion of the first solvent into the reaction kettle for dilution to obtain an acrylate polymer.

[0072] The preparation method of the high temperature electrolyte resistant acrylic pressure sensitive adhesive of this embodiment adopts the above steps to improve the performance of the polymer. Among them, the sum of the first part of the first solvent, the second part of the first solvent, the third part of the first solvent, the fourth part of the first solvent and the fifth part of the first solvent is the total amount of the first solvent, the sum of the first part of the long chain acrylate monomer and the second part of the long chain acrylate monomer is the total amount of the long chain acrylate monomer, the sum of the first part of the long chain methacrylate monomer and the second part of the long chain methacrylate monomer is the total amount of the long chain methacrylate monomer, and the sum of the first part of the initiator, the second part of the initiator and the third part of the initiator is the total amount of the initiator. Adding multiple substances in steps can better control the reaction process.

[0073] In some embodiments, in step 1, the mixture of the second part of the first solvent and the first part of the initiator is added dropwise to the reaction kettle in an inert gas atmosphere; the reaction temperature is 80-83° C., and the reaction time is 1-2 h.

[0074] In some embodiments, in step 2, the second part of the long-chain acrylate monomer and the second part of the long-chain methacrylate monomer are mixed and added dropwise to the reactor, and the third part of the first solvent and the second part of the initiator are mixed and added dropwise to the reactor for 1 to 1.5 hours, and then kept warm for reaction for 2.5 to 3.5 hours; the fourth part of the first solvent and the third part of the initiator are mixed, added to the reactor and kept warm for 3 to 5 hours.

[0075] In some embodiments, after step three, step four is further included: uniformly stirring the acrylate polymer obtained in step three with the curing agent and the second solvent to obtain a high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive.

[0076] The present embodiment also provides a swelling tape, which includes a swelling substrate layer and a pressure-sensitive adhesive layer disposed on the swelling substrate layer, wherein the pressure-sensitive adhesive layer is made of the above-mentioned high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive or the high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive obtained by the above-mentioned preparation method. The swelling tape can be wound up for storage and then cut when used. The swelling tape is suitable for batteries, and the swelling tape includes a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive and a swelling substrate having the property of swelling by adsorbing electrolyte. After absorbing electrolyte, the swelling tape expands to fill the gap between the battery cell and the shell inside the battery, and at the same time has viscosity and is fixed in the gap position without relative displacement, thereby providing a solution for the safe protection of battery operation and eliminating potential safety hazards of the battery during use, especially under harsh working conditions.

[0077] In some embodiments, the swelling substrate layer includes a polyester polyurethane swelling material. The polyester polyurethane swelling material has good swelling properties and electrolyte resistance.

[0078] In some embodiments, the thickness of the pressure-sensitive adhesive layer is 5 to 15 μm, preferably 5 to 10 μm, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 μm, etc. The thickness of the swelling substrate layer is 15 to 60 μm, preferably 20 to 50 μm, for example, 20, 25, 30, 35, 40, 45, 50 μm, etc. The swelling tape with the above thickness is suitable for filling between the battery cell and the shell in the battery, which is convenient for assembling the battery with the swelling tape.

[0079] This embodiment also provides a method for preparing the above-mentioned swelling tape, which includes the following steps: coating a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive on a release film, and drying and curing to form a pressure-sensitive adhesive layer; compounding the pressure-sensitive adhesive layer to a swelling substrate layer; and peeling off the release film. The coating method can be a transfer coating method, such as a doctor blade transfer coating, a stick transfer coating, or a micro-concave transfer coating method.

[0080] The present embodiment also provides a battery, including a shell and a battery cell located in the shell, with a gap between the battery cell and the shell, and the battery also includes the above-mentioned swelling tape or the swelling tape obtained by the above-mentioned preparation method, the swelling tape is immersed in the electrolyte in the gap and expands to fill the gap. The battery can be a liquid electrolyte battery, such as a lithium-ion battery. The swelling tape is used for filling and wrapping protection between the internal battery cell and the shell of the lithium-ion battery. The swelling tape can be bonded to the inner surface of the shell and / or the outer surface of the battery cell. When the swelling tape contacts the electrolyte, the swelling tape will swell and fill the gap between the battery cell and the shell. The swelling tape of this embodiment is fixed at the position of the gap between the battery cell and the shell without relative displacement, and absorbs part of the electrolyte at the same time, reducing the direct contact of the electrolyte with the inside of the shell, slowing down the corrosion process of the shell, reducing the risk of safety problems such as battery short circuit, increased internal resistance of the battery, and heating, thereby improving safety.

[0081] The present invention will be further described in detail below through specific examples. In the following examples, unless otherwise specified, the material composition and source of the raw material components with the same name are the same.

[0082] Example 1

[0083] 1. Preparation of Acrylate Polymer

[0084] 1. Raw material composition:

[0085] Long chain acrylate monomer: isooctyl acrylate, 40 parts;

[0086] Long chain methacrylate monomer: isooctyl methacrylate, 3 parts;

[0087] Acrylic acid functional monomer: acrylic acid, 0.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0088] Hard monomer: methyl methacrylate, 3 parts;

[0089] Initiator: dibenzoyl peroxide, 0.04 parts, azobisisobutyronitrile, 0.08 parts;

[0090] First solvent: ethyl acetate, 52.88 parts.

[0091] 2. Preparation method:

[0092] (1) 30 parts of ethyl acetate, 24.0 parts of isooctyl acrylate, 1.8 parts of isooctyl methacrylate, 0.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 3 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred to mix evenly; nitrogen was introduced into the reaction kettle, 0.04 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0093] (2) Start dripping a mixture of 16 parts of isooctyl acrylate and 1.2 parts of isooctyl methacrylate, dissolve 0.04 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.04 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0094] (3) 13.88 parts of ethyl acetate was added to dilute the mixture to a solid content of 47.0±1% to obtain a light yellow, transparent, viscous acrylic polymer having a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0095] 2. Preparation of Swelling Tape

[0096] 1. Raw material composition:

[0097] 80 parts of the acrylate polymer prepared in step 1;

[0098] Curing agent: tetrafunctional epoxidized meta-xylylenediamine curing agent (model: GA-240, manufacturer: Shenzhen Jiadida Chemical Co., Ltd.), 2 parts;

[0099] Second solvent: ethyl acetate, 15 parts;

[0100] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0101] 2. Preparation method:

[0102] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic polymer prepared in step 1, GA-240, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0103] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0104] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the swelling substrate layer.

[0105] Example 2

[0106] 1. Preparation of Acrylate Polymer

[0107] 1. Raw material composition:

[0108] Long chain acrylate monomer: isooctyl acrylate, 20 parts;

[0109] Long chain methacrylate monomer: isooctyl methacrylate, 10 parts;

[0110] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0111] Hard monomer: methyl methacrylate, 12 parts;

[0112] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0113] First solvent: ethyl acetate, 54.0 parts.

[0114] 2. Preparation method:

[0115] (1) 30 parts of ethyl acetate, 12 parts of isooctyl acrylate, 6 parts of isooctyl methacrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 12 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred to mix evenly; nitrogen was introduced into the reaction kettle, 0.8 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0116] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 4 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it within 10 minutes, and keep it warm for 4 hours;

[0117] (3) Add 15 parts of ethyl acetate to dilute to a solid content of 45.0±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0118] 2. Preparation of Swelling Tape

[0119] 1. Raw material composition:

[0120] 80 parts of the acrylate polymer prepared in step 1;

[0121] Curing agent: tetrafunctional epoxidized meta-xylylenediamine curing agent (model: GA-240, manufacturer: Shenzhen Jiadida Chemical Co., Ltd.), 2 parts;

[0122] Second solvent: ethyl acetate, 15 parts;

[0123] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0124] 2. Preparation method:

[0125] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic polymer prepared in step 1, GA-240, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0126] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0127] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0128] Example 3

[0129] 1. Preparation of Acrylate Polymer

[0130] 1. Raw material composition:

[0131] Long chain acrylate monomer: 20 parts of isooctyl acrylate and 10 parts of lauryl acrylate;

[0132] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0133] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0134] Hard monomer: methyl methacrylate, 6 parts;

[0135] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0136] First solvent: ethyl acetate, 54.0 parts.

[0137] 2. Preparation method:

[0138] (1) 30 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 10 parts of lauryl acrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 6 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred and mixed evenly; nitrogen was introduced into the reaction kettle, 0.8 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0139] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0140] (3) Add 15 parts of ethyl acetate to dilute to a solid content of 45±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0141] 2. Preparation of Swelling Tape

[0142] 1. Raw material composition:

[0143] 80 parts of the acrylate polymer prepared in step 1;

[0144] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0145] Second solvent: ethyl acetate, 15 parts;

[0146] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0147] 2. Preparation method:

[0148] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0149] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0150] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0151] Example 4a

[0152] 1. Preparation of Acrylate Polymer

[0153] 1. Raw material composition:

[0154] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0155] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0156] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0157] Hard monomer: methyl methacrylate, 6 parts;

[0158] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0159] First solvent: ethyl acetate, 54.0 parts.

[0160] 2. Preparation method:

[0161] (1) 30 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 6 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred and mixed evenly; nitrogen was introduced into the reaction kettle, 0.8 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0162] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0163] (3) Add 15 parts of ethyl acetate to dilute to a solid content of 45.0±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0164] 2. Preparation of Swelling Tape

[0165] 1. Raw material composition:

[0166] 80 parts of the acrylate polymer prepared in step 1;

[0167] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0168] Second solvent: ethyl acetate, 15 parts;

[0169] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0170] 2. Preparation method:

[0171] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0172] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0173] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0174] Example 4b

[0175] 1. Preparation of Acrylate Polymer

[0176] 1. Raw material composition:

[0177] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0178] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0179] Acrylic acid functional monomer: acrylic acid, 2.0 parts, hydroxyethyl acrylate, 0.4 parts;

[0180] Methacrylic acid functional monomer: methacrylic acid: 0.5 parts, hydroxyethyl methacrylate, 0.1 parts;

[0181] Hard monomer: methyl methacrylate, 6 parts;

[0182] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0183] First solvent: ethyl acetate, 54.0 parts.

[0184] 2. Preparation method:

[0185] (1) 30 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 2.0 parts of acrylic acid, 0.4 parts of hydroxyethyl acrylate, 0.5 parts of methacrylic acid, 0.1 parts of hydroxyethyl methacrylate, and 6 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred and mixed evenly; nitrogen was introduced into the reaction kettle, 0.8 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0186] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0187] (3) Add 15 parts of ethyl acetate to dilute to a solid content of 45.0±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0188] 2. Preparation of Swelling Tape

[0189] 1. Raw material composition:

[0190] 80 parts of the acrylate polymer prepared in step 1;

[0191] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0192] Second solvent: ethyl acetate, 15 parts;

[0193] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0194] 2. Preparation method:

[0195] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0196] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0197] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0198] Example 4c

[0199] 1. Preparation of Acrylate Polymer

[0200] 1. Raw material composition:

[0201] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0202] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0203] Acrylic acid functional monomer: acrylic acid, 1.25 parts, hydroxyethyl acrylate, 0.25 parts;

[0204] Methacrylic acid functional monomer: methacrylic acid: 1.25 parts, hydroxyethyl methacrylate, 0.25 parts;

[0205] Hard monomer: methyl methacrylate, 6 parts;

[0206] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0207] First solvent: ethyl acetate, 54.0 parts.

[0208] 2. Preparation method:

[0209] (1) 30 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 1.25 parts of acrylic acid, 0.25 parts of hydroxyethyl acrylate, 1.25 parts of methacrylic acid, 0.25 parts of hydroxyethyl methacrylate, and 6 parts of methyl methacrylate were added to a reaction kettle equipped with a thermometer, a condenser, and an emulsifying tank, and stirred and mixed evenly; nitrogen was introduced into the reaction kettle, 0.8 parts of dibenzoyl peroxide was dissolved in 3 parts of ethyl acetate, and added to the reaction kettle, and stirring and heating were started, and the mixture was heated to 80° C. and reacted for 1 hour;

[0210] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0211] (3) Add 15 parts of ethyl acetate to dilute to a solid content of 45.0±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0212] 2. Preparation of Swelling Tape

[0213] 1. Raw material composition:

[0214] 80 parts of the acrylate polymer prepared in step 1;

[0215] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0216] Second solvent: ethyl acetate, 15 parts;

[0217] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0218] 2. Preparation method:

[0219] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0220] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0221] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0222] Example 5a

[0223] 1. Preparation of Acrylate Polymer

[0224] 1. Raw material composition:

[0225] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0226] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0227] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0228] Hard monomer: methyl methacrylate, 6 parts;

[0229] SIS elastomer: 2.0 parts (model SIS-1106, manufacturer: Yueyang Baling Petrochemical Co., Ltd.);

[0230] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0231] The first solvent: ethyl acetate, 50.0 parts, toluene, 2 parts.

[0232] 2. Preparation method:

[0233] (1) Dissolve 2 parts of SIS in 2 parts of toluene to prepare elastomer, 28 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 6 parts of methyl methacrylate in a reactor equipped with a thermometer, a condenser, and an emulsifier, and stir to mix evenly; introduce nitrogen into the reactor, dissolve 0.8 parts of dibenzoyl peroxide in 3 parts of ethyl acetate, add the mixture to the reactor, and start stirring and heating. Heat to 80°C and react for 1 hour;

[0234] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0235] (3) 13 parts of ethyl acetate was added to dilute the mixture to a solid content of 47.0±1% to obtain a light yellow, transparent, viscous acrylic polymer having a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0236] 2. Preparation of Swelling Tape

[0237] 1. Raw material composition:

[0238] 80 parts of the acrylate polymer prepared in step 1;

[0239] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0240] Second solvent: ethyl acetate, 15 parts;

[0241] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0242] 2. Preparation method:

[0243] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0244] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0245] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0246] Example 5b

[0247] 1. Preparation of Acrylate Polymer

[0248] 1. Raw material composition:

[0249] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0250] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0251] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0252] Hard monomer: methyl methacrylate, 6 parts;

[0253] SIS elastomer: 4.0 parts (model SIS-1106, manufacturer: Yueyang Baling Petrochemical Co., Ltd.);

[0254] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0255] First solvent: ethyl acetate, 46.0 parts, toluene, 4 parts;

[0256] 2. Preparation method:

[0257] (1) Dissolve 4 parts of SIS in 4 parts of toluene to prepare an elastomer, 26 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 6 parts of methyl methacrylate in a reactor equipped with a thermometer, a condenser, and an emulsifier, and stir to mix evenly; introduce nitrogen into the reactor, dissolve 0.8 parts of dibenzoyl peroxide in 3 parts of ethyl acetate, add the mixture to the reactor, and start stirring and heating. Heat to 80°C and react for 1 hour;

[0258] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0259] (3) 11 parts of ethyl acetate was added to dilute the mixture to a solid content of 49.0±1% to obtain a light yellow, transparent, viscous acrylic polymer having a viscosity of 4000 to 8000 cps and a molecular weight of 800,000 to 1,000,000.

[0260] 2. Preparation of Swelling Tape

[0261] 1. Raw material composition:

[0262] 80 parts of the acrylate polymer prepared in step 1;

[0263] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0264] Second solvent: ethyl acetate, 15 parts;

[0265] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0266] 2. Preparation method:

[0267] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0268] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0269] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0270] Example 5c

[0271] 1. Preparation of Acrylate Polymer

[0272] 1. Raw material composition:

[0273] Long chain acrylate monomer: isooctyl acrylate, 20 parts, lauryl acrylate, 5 parts, isobornyl acrylate, 5 parts;

[0274] Long chain methacrylate monomer: isooctyl methacrylate, 6 parts;

[0275] Acrylic acid functional monomer: acrylic acid, 2.5 parts, hydroxyethyl acrylate, 0.5 parts;

[0276] Hard monomer: methyl methacrylate, 6 parts;

[0277] SIS elastomer: 6.0 parts (model SIS-1106, manufacturer: Yueyang Baling Petrochemical Co., Ltd.);

[0278] Initiator: dibenzoyl peroxide, 0.8 parts, azobisisobutyronitrile, 0.2 parts;

[0279] The first solvent: ethyl acetate, 42.0 parts, toluene, 6 parts.

[0280] 2. Preparation method:

[0281] (1) Dissolve 6 parts of SIS in 6 parts of toluene to prepare elastomer, 24 parts of ethyl acetate, 12 parts of isooctyl acrylate, 4 parts of isooctyl methacrylate, 5 parts of lauryl acrylate, 5 parts of isobornyl acrylate, 2.5 parts of acrylic acid, 0.5 parts of hydroxyethyl acrylate, and 6 parts of methyl methacrylate in a reactor equipped with a thermometer, a condenser, and an emulsifier, and stir to mix evenly; introduce nitrogen into the reactor, dissolve 0.8 parts of dibenzoyl peroxide in 3 parts of ethyl acetate, add the mixture to the reactor, and start stirring and heating, heating to 80°C and reacting for 1 hour;

[0282] (2) Start dripping a mixture of 8 parts of isooctyl acrylate and 2 parts of isooctyl methacrylate, dissolve 0.12 parts of azobisisobutyronitrile in 3 parts of ethyl acetate and mix well, drip it into the reaction kettle and drip it all within 90 minutes, keep it warm at 82°C for 3 hours, then drip 0.08 parts of azobisisobutyronitrile dissolved in 3 parts of ethyl acetate and drip it all within 10 minutes, and keep it warm for 4 hours;

[0283] (3) Add 9 parts of ethyl acetate to dilute to a solid content of 51.0±1% to obtain a light yellow, transparent, viscous acrylic polymer with a viscosity of 4000-8000 cps and a molecular weight of 800,000-1,000,000.

[0284] 2. Preparation of Swelling Tape

[0285] 1. Raw material composition:

[0286] 80 parts of the acrylate polymer prepared in step 1;

[0287] Curing agent: isocyanate curing agent (model: L-45, manufacturer: Covestro Polymers (China) Co., Ltd.), 1.5 parts;

[0288] Second solvent: ethyl acetate, 15 parts;

[0289] Swelling substrate: polyester polyurethane swelling substrate (model: 3F-S6398SW manufacturer: Guangzhou Sanfu Chemical Co., Ltd.).

[0290] 2. Preparation method:

[0291] (1) Preparing a pressure-sensitive adhesive: When preparing the adhesive, the acrylic acid ester polymer prepared in step 1, L-45, and ethyl acetate are mixed and stirred uniformly in a mass ratio to obtain a coating adhesive preparation formula;

[0292] (2) Preparation of swelling tape: The pressure-sensitive adhesive prepared in step (1) is coated on a 50 μm PET release film, and after curing and drying, the surface of the pressure-sensitive adhesive layer is laminated to the non-release surface of the swelling substrate layer, and finally the release film is dissociated to obtain an electrolyte-resistant swelling tape, wherein the drying temperature is 110° C. and the drying time is 2 min.

[0293] The thickness of each layer of the product is: 5μm for the pressure-sensitive adhesive layer and 45μm for the substrate layer.

[0294] Comparative Example 1

[0295] This comparative example is used to illustrate the effect of long-chain methacrylate monomers on product performance when used in combination. This comparative example is carried out with reference to Example 1, wherein 43 parts of isooctyl acrylate are used, and no long-chain methacrylate monomer is contained. The amount of isooctyl acrylate added in step (1) of preparing the acrylic ester polymer is 25.8 parts, and the amount of isooctyl acrylate added in step (2) is 17.2 parts. Other than these, the other components and their preparation methods are the same as those in Example 1.

[0296] Performance Testing

[0297] The swelling tapes prepared in Examples 1-5 and Comparative Example 1 were subjected to performance tests. The specific test methods are as follows. The measured results are shown in Table 1.

[0298] (1) 180° peel strength: measured in accordance with GB / T 2792-2014 Test method for peel strength of adhesive tapes using a peel strength tensile testing machine (tape width: 25 mm, 25 μm PET backing as reinforcement, peel rate: 300 mm / min).

[0299] (2) Initial tack: According to GB / T 4852-2002 “Test method for initial tack of pressure-sensitive adhesive tapes (rolling ball method)”, the initial tack tester was used for measurement (the tilt angle was 30°).

[0300] (3) Stickiness: The test is carried out in accordance with GB / T 4851-2014. The adhered sample with the pressure-sensitive adhesive tape is hung vertically on a test frame, and a weight of a specified mass is hung below. The displacement of the adhered sample sliding down in a certain period of time (or the time for the adhered sample to completely detach) is used to characterize the stickiness of the pressure-sensitive adhesive.

[0301] (4) Electrolyte resistance: The prepared pressure-sensitive adhesive was coated on a 25 μm PET film, and after curing and drying, an electrolyte-resistant test tape was obtained. The drying temperature was 110°C, the drying time was 2 min, and the coating thickness was 5-10 μm. The test tape sample was laminated to a 12 μm aluminum foil and fully flattened using a small rubber roller. The tape was well laminated to the aluminum foil without bubbles or wrinkles. Then it was cut into several 25×25 mm tape sample pieces. The cut sample was placed in a 1000 mL PP plastic bottle, and then the battery-specific electrolyte was poured in. The electrolyte level submerged the tape sample. Then the test bottle was placed in a room temperature and 85°C environment and left to stand for 12 hours, 24 hours, 48 ​​hours, 72 hours, and 7 days, respectively. The test tape sample in the test bottle was taken out to observe whether the tape fell off the aluminum foil, and whether there was electrolyte immersion at the edge of the tape and the aluminum foil, or whether the sample penetrated.

[0302] (5) Residual adhesive performance test: stick the swelling tape on a clean special test stainless steel plate, press the tape at each sticking point, and place it in a constant temperature and humidity test chamber set at 85°C and 85% humidity. After 24 hours, take out the sample and cool it down thoroughly, tear it open and observe whether there is any residual adhesive on the steel plate.

[0303] (6) Swelling performance test: Cut the test tape sample into several pieces of 25×25 mm in size, and use a digital high-precision vernier caliper to measure the thickness A1 of the tape sample. Place the cut sample in a clean glass petri dish with a lid, add a battery-specific electrolyte so that the liquid level exceeds the sample and fully immerses the sample. Place the sample in an environment of 85°C for 7 days, take out the sample, place it in a special glass dish and flatten it, and use a digital high-precision vernier caliper to measure the thickness A2 of the tape sample.

[0304] Swelling ratio = (A2-A1)÷A1×100%.

[0305] The battery electrolyte mentioned above is a specific electrolyte of the battery manufacturer, such as the electrolyte product of Ningbo Shanshan Co., Ltd.: Ld-88; the electrolyte product of Xinzhoubang Technology Co., Ltd.: l bc305. This test adopts the former.

[0306] Table 1 - Swelling tape performance test results

[0307]

[0308]

[0309] It can be seen from the comparative examples that each component in the embodiment has a specific role, thereby achieving the application effect of the product. Long-chain acrylate monomers are used as the main monomers. Long-chain acrylate polymers are insoluble in solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) in the electrolyte due to their long-chain ester structure. A certain proportion of methyl long-chain acrylate monomers and acrylic acid functional monomers are added to synthesize acrylate polymers. The introduction of long-chain methacrylate monomers enhances the spatial steric effect of the molecular chain. An external multi-functional curing agent is used for later cross-linking to form a molecular structure with a suitable cross-linking density, so that the temperature resistance of the acrylate pressure-sensitive adhesive is enhanced. The final beneficial effect of the product is that the tape product has excellent electrolyte resistance under high temperature conditions. Functional monomers acrylic acid and hydroxyethyl acrylate provide cross-linking points of different functional groups for the pressure-sensitive adhesive molecular chain, and can undergo later cross-linking reactions with various curing agents to enhance cohesion, improve residual glue and high temperature resistance. A more ideal application effect can be achieved by using a suitable addition ratio range and mixed functional monomers. The swelling substrate layer is a polyester polyurethane swelling material, which not only has excellent swelling performance but also has good adhesion with the electrolyte-resistant acrylic pressure-sensitive adhesive, ensuring that the swelling tape maintains the integrity of its shape and realizes the filling functionality in an environment full of electrolyte.

[0310] In order to enhance the electrolyte resistance of acrylic pressure-sensitive adhesive, some embodiments add rubber thermoplastic elastomer SIS for graft polymerization modification, which can increase the electrolyte resistance and adhesion of the product. This is mainly due to the introduction of SIS elastomer, which changes the molecular chain structure of the original acrylic pressure-sensitive adhesive. In addition, SIS elastomer has excellent electrolyte resistance and can maintain good adhesion in the electrolyte environment, thereby enhancing the electrolyte resistance of the product. If the amount of SIS elastomer added is too small, the final electrolyte resistance of the product will not increase significantly. If the amount added is too large, the viscosity of the SIS elastomer after dissolving in the solvent is very large due to its large molecular weight, and it is difficult to dissolve, thus affecting the viscosity and coating performance of the acrylic pressure-sensitive adhesive. If the adhesion of the product is too large, it will affect the operability and process of the product. If the adhesion is too small, it will not stick to the adherend, resulting in bonding failure. Some of the above embodiments add a suitable amount of rubber thermoplastic elastomer SIS to obtain suitable adhesion performance and better meet the application requirements of the product.

[0311] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. High temperature electrolyte resistant acrylic pressure sensitive adhesive, characterized in that The invention comprises an acrylate polymer, wherein the acrylate polymer is made of raw materials comprising the following components in parts by weight: 20-40 parts of long chain acrylate monomer; 3 to 10 parts of long chain methacrylate monomer; 1.0-3.0 parts of acrylic acid functional monomer; Methacrylic acid functional monomer 0-1.5 parts; 3 to 12 parts of hard monomer; SIS elastomer 0-6 parts; Initiator 0.1-1.0 part; 48-56 parts of the first solvent; The long-chain acrylate monomer is a mixture of isooctyl acrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of isooctyl acrylate, lauryl acrylate and isobornyl acrylate is 20:(3-10):(3-10); The long-chain methacrylate monomer includes one or more of isooctyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and octadecyl methacrylate; The acrylic acid functional monomer is a mixture of acrylic acid and one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and acrylamide, and the amount of acrylic acid accounts for 50 to 85% of the total amount of the acrylic acid functional monomer; The methacrylic acid functional monomer includes one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, and methacrylic acid; The hard monomer is one or more of methyl methacrylate, methyl acrylate, styrene and vinyl acetate.

2. The high temperature electrolyte resistant acrylic pressure sensitive adhesive according to claim 1, characterized in that: The weight portion of the methacrylic acid functional monomer is 0.6 to 1.5 parts; The weight portion of the SIS elastomer is 2 to 6 parts; the SIS elastomer is a thermoplastic elastomer obtained by anionic polymerization.

3. The high temperature electrolyte resistant acrylic pressure sensitive adhesive according to claim 2, characterized in that: The methacrylic acid functional monomer is a mixture of methacrylic acid and one or two of hydroxyethyl methacrylate and hydroxypropyl methacrylate, and the amount of methacrylic acid accounts for 70-80% of the total amount of methacrylic acid functional monomers; The SIS elastomer is one or more of the products of Baling Petrochemical Co., Ltd. with model numbers SIS1105, SIS1106, SIS1209, SIS11026, SIS4019, SIS1124, and SIS1126.

4. The high temperature electrolyte resistant acrylate pressure sensitive adhesive according to any one of claims 1 to 3, characterized in that: The initiator includes one or more of azobisisobutyronitrile, dibenzoyl peroxide, and cumene peroxide; The first solvent includes one or more of ethyl acetate, toluene, and xylene; The solid content of the acrylic ester polymer is 44-52%, the viscosity is 4000-8000 CPS, and the weight average molecular weight Mw is 600,000-1.2 million.

5. The high temperature electrolyte resistant acrylic pressure sensitive adhesive according to claim 4, characterized in that: The initiator is a mixture of azobisisobutyronitrile and one or two of dibenzoyl peroxide and cumene peroxide, and the amount of azobisisobutyronitrile accounts for 20-70% of the total amount of the initiator.

6. The high temperature electrolyte resistant acrylate pressure sensitive adhesive according to any one of claims 1 to 3, characterized in that It also includes a curing agent and a second solvent, wherein the mass ratio of the acrylate polymer, the curing agent and the second solvent is 80: (0.5-2.5): (10-20); The curing agent includes one or both of an isocyanate curing agent and an epoxy curing agent; the isocyanate curing agent is hexamethylene diisocyanate biuret, and the epoxy curing agent is a tetrafunctional epoxy curing agent; The second solvent includes one or more of ethyl acetate, toluene, and xylene.

7. The method for preparing the high temperature electrolyte resistant acrylic pressure sensitive adhesive according to any one of claims 1 to 6, characterized in that The following steps are involved: Step 1: Add the first part of the first solvent, the first part of the long-chain acrylate monomer, the first part of the long-chain methacrylate monomer, the acrylic functional monomer, the methacrylic functional monomer, the hard monomer, and the SIS elastomer into the reactor, and stir and mix them evenly; mix the second part of the first solvent and the first part of the initiator, and add them dropwise into the reactor to react; Step 2: Mix the second part of the long-chain acrylate monomer and the second part of the long-chain methacrylate monomer and drop them into the reactor; mix the third part of the first solvent and the second part of the initiator and drop them into the reactor, and keep the temperature for reaction; mix the fourth part of the first solvent and the third part of the initiator, add them into the reactor, and keep the temperature for reaction; Step 3: Add the fifth portion of the first solvent into the reaction kettle for dilution to obtain an acrylate polymer.

8. The preparation method according to claim 7, characterized in that: In step 1, the mixture of the second part of the first solvent and the first part of the initiator is added dropwise to the reaction kettle in an inert gas atmosphere; the reaction temperature is 80-83° C., and the reaction time is 1-2 hours; In step 2, the second part of the long-chain acrylate monomer and the second part of the long-chain methacrylate monomer are mixed and then added dropwise to the reactor, and the third part of the first solvent and the second part of the initiator are mixed and then added dropwise to the reactor for 1 to 1.5 hours, and then kept warm for reaction for 2.5 to 3.5 hours; the fourth part of the first solvent and the third part of the initiator are mixed, added to the reactor and kept warm for 3 to 5 hours; After step three, the method further includes step four: uniformly stirring the acrylic polymer obtained in step three with the curing agent and the second solvent to obtain a high-temperature electrolyte-resistant acrylic pressure-sensitive adhesive.

9. Swelling tape, characterized in that It comprises a swelling substrate layer and a pressure-sensitive adhesive layer arranged on the swelling substrate layer, wherein the pressure-sensitive adhesive layer is made of the high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive according to any one of claims 1 to 6 or the high-temperature electrolyte-resistant acrylate pressure-sensitive adhesive obtained by the preparation method according to claim 7 or 8.

10. The method for preparing a swelling tape according to claim 9, characterized in that The following steps are involved: Applying the high temperature electrolyte resistant acrylate pressure sensitive adhesive to the release film, and drying and curing the acrylate pressure sensitive adhesive to form a pressure sensitive adhesive layer; Compounding the pressure-sensitive adhesive layer to the swollen substrate layer; peeling off the release film; The swelling substrate layer includes a polyester polyurethane swelling material; The thickness of the pressure-sensitive adhesive layer is 5 to 15 μm; The thickness of the swelling substrate layer is 15 to 60 μm.

11. The method for preparing a swelling tape according to claim 10, characterized in that: The thickness of the pressure-sensitive adhesive layer is 5 to 10 μm; The thickness of the swelling substrate layer is 20 to 50 μm.

12. A battery comprising a housing and a cell in the housing, wherein a gap exists between the cell and the housing, characterized in that It also includes the swelling tape according to claim 9 or the swelling tape prepared by the preparation method according to claim 10 or 11, wherein the swelling tape is arranged in the gap and expands to fill the gap.

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