A water-based acrylate pressure-sensitive adhesive for battery labels and a method for preparing the same

Abstract

This invention belongs to the field of adhesive technology, specifically relating to a water-based acrylic pressure-sensitive adhesive for battery labels and its preparation method. The raw materials for preparing the water-based acrylic pressure-sensitive adhesive for battery labels include monomers, initiators, emulsifiers, tackifiers, chain transfer agents, solvents, buffers, and pH adjusters. The water-based acrylic pressure-sensitive adhesive for battery labels provided by this invention, through optimized formulation and polymerization process, significantly improves its adhesion, ensuring a strong bond between the label and the battery casing. Simultaneously, this pressure-sensitive adhesive exhibits excellent adhesive strength, maintaining a stable bonding effect and effectively preventing label detachment. Furthermore, its excellent anti-peeling properties ensure that the label edges are not prone to peeling during long-term use, thereby improving the overall durability and aesthetics of the battery label, providing battery manufacturers with a high-performance, environmentally friendly, and economical label adhesive solution.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to a water-based acrylic pressure-sensitive adhesive for battery labels and its preparation method. Background Technology

[0002] With increasing global environmental awareness and the growing acceptance of sustainable development concepts, various industries are placing increasingly stringent requirements on the selection and use of materials. This is particularly true in industries such as electronics, communications, and automobiles, where the application of environmentally friendly materials has become an irreversible trend. Against this backdrop, water-based adhesives, due to their low volatile organic compound (VOC) emissions, environmental friendliness, ease of processing, and recyclability, are gradually gaining a significant position in the adhesive market.

[0003] However, despite the enormous application potential of water-based adhesives in many fields, their application in battery label materials faces some challenges. In particular, water-based pressure-sensitive adhesives, while environmentally friendly, often exhibit problems such as poor adhesive strength and edge curling in practical applications. Poor adhesive strength means that the label is prone to detachment or loss of adhesion after use, affecting battery identification and tracking; while edge curling can cause the label edges to lift, affecting not only aesthetics but also potentially reducing the label's protective effect and readability.

[0004] To address the aforementioned issues, this research aims to develop a water-based acrylic pressure-sensitive adhesive specifically for battery tag materials. This adhesive combines the environmentally friendly properties of water-based adhesives with the superior performance of acrylic materials, achieving improved bond strength and effectively solving the problem of edge lifting through innovative formulation design and manufacturing processes. Summary of the Invention

[0005] The purpose of this invention is to provide a water-based acrylic pressure-sensitive adhesive for battery labels and its preparation method. The water-based acrylic pressure-sensitive adhesive for battery labels not only meets the requirements of green environmental protection, but also meets the stability and reliability requirements of battery labels in long-term use. It provides battery manufacturers with a high-performance and sustainable solution, promotes the greening and environmental protection of battery label materials, and helps to achieve the goal of sustainable development.

[0006] A water-based acrylic pressure-sensitive adhesive for battery labels, the raw materials for which are prepared include monomers, initiators, emulsifiers, tackifiers, chain transfer agents, solvents, buffers, and pH adjusters.

[0007] Preferably, the monomers include soft monomers, hard monomers, and crosslinking monomers.

[0008] Preferably, the soft monomer includes one or more of butyl acrylate, n-octyl acrylate, and isooctyl acrylate; more preferably, it is butyl acrylate.

[0009] Preferably, the hard monomer includes one or more of styrene, methyl methacrylate, and vinyl acetate; more preferably, it is styrene.

[0010] Preferably, the crosslinking monomer includes one or more of acrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethylacrylamide, and glycidyl methacrylate; more preferably, it is acrylic acid and hydroxyethyl methacrylate.

[0011] Preferably, the mass ratio of acrylic acid to hydroxyethyl methacrylate is 1:(2~4); more preferably, it is 1:3.

[0012] Preferably, the mass ratio of the soft monomer, hard monomer, and crosslinking monomer is (45~50):(1~3):1; more preferably, it is 95:4:2.

[0013] The inventors discovered that by selecting specific soft monomers, hard monomers, and crosslinking monomers, and adjusting the proportions of each component, it is possible to improve the adhesive performance of pressure-sensitive adhesives while simultaneously enhancing their resistance to peeling. This is because these monomers have a synergistic effect. Butyl acrylate provides good initial tack and holding power, while styrene enhances the rigidity and cohesiveness of the adhesive; the combination of the two achieves a balance between flexibility and rigidity. The three-dimensional network structure formed by the crosslinking reaction of acrylic acid and hydroxyethyl methacrylate further enhances the cohesiveness and mechanical strength of the adhesive, improving its heat resistance and chemical resistance. This multi-level structural design allows the adhesive to maintain good flexibility while possessing sufficient rigidity and cohesiveness, reducing peeling. In addition, the presence of the crosslinking structure effectively prevents polymer degradation during long-term use, extending the adhesive's service life. Therefore, by adjusting the proportions of these monomers, synergistic effects can be achieved in multiple aspects, significantly improving the overall performance of pressure-sensitive adhesives and meeting the needs of applications such as battery tags.

[0014] Preferably, the initiator is one or both of ammonium persulfate and potassium persulfate; more preferably, it is ammonium persulfate.

[0015] Preferably, the amount of the initiator added is 0.3% to 0.5% of the monomer mass.

[0016] Preferably, the emulsifier includes reactive emulsifiers and anionic emulsifiers.

[0017] Preferably, the mass ratio of the reactive emulsifier to the anionic emulsifier is 1:(0.5~2); more preferably, it is 1:1.

[0018] Preferably, the reactive emulsifier is ammonium allyloxynonylphenol propanol polyoxyethylene (10) ether sulfate and allyloxynonylphenol propanol polyoxyethylene ether.

[0019] Preferably, the mass ratio of allyloxynonylphenol ether and its sulfonate to allyloxynonylphenol propanol polyoxyethylene ether is (1~3):1; more preferably, it is 2:1.

[0020] Preferably, the effective content of the allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate is 95%, and the viscosity at 25°C is <35000cps.

[0021] Preferably, the allyloxynonylphenol propanol polyoxyethylene ether has an effective content of 99%, a viscosity of <300cps at 25°C, an acid value of 0.07~0.09gKOH / g, a hydroxyl value of 73~75mgKOH / g, and an HLB value of 12.6.

[0022] In some preferred embodiments, the allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate and allyloxynonylphenol propanol polyoxyethylene ether are both purchased from Guangzhou Shuangjian Trading Co., Ltd., DNS-86 and ANPEO10.

[0023] Preferably, the anionic emulsifier is sodium dodecyl sulfate and alkylphenol polyoxyethylene ether.

[0024] Preferably, the mass ratio of sodium dodecyl sulfate to alkylphenol polyoxyethylene ether is 1:(0.5~2); more preferably, it is 1:1.

[0025] Preferably, the alkylphenol polyoxyethylene ether has a cloud point of 68~78℃, a hydroxyl value of 87±5mgKOH / g, and an HLB value of 13.3~14.

[0026] In some preferred embodiments, the alkylphenol polyoxyethylene ether is purchased from Jiangsu Haian Petrochemical Plant, OP-10.

[0027] Preferably, the amount of emulsifier added is 2% to 5% of the monomer mass.

[0028] The inventors discovered that by using specific reactive and anionic emulsifiers together as emulsifiers, the adhesive properties and anti-lifting properties of pressure-sensitive adhesives can be further improved. This is likely because allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate and allyloxynonylphenol propanol polyoxyethylene ether not only possess the functions of traditional emulsifiers—reducing surface tension, promoting monomer dispersion, and stabilizing the emulsion—they can also chemically react with polymer chains, thereby anchoring them more firmly to the surface of polymer particles. This chemical bonding reduces the migration and shedding of emulsifier molecules, making the emulsion more stable, and thus improving the adhesive strength and durability of the pressure-sensitive adhesive. In addition, reactive emulsifiers can introduce additional crosslinking points into the polymer network, helping to enhance the cohesive force and anti-lifting properties of the pressure-sensitive adhesive. Sodium dodecyl sulfate and alkylphenol polyoxyethylene ether, as anionic emulsifiers, can work together with reactive emulsifiers to form more compact and uniform emulsion particles, thereby improving the microstructure and dispersion uniformity of the pressure-sensitive adhesive. The addition of anionic emulsifiers can promote the interaction between polymer chains, forming more physical crosslinking points. These crosslinking points help improve the elastic modulus and resistance to deformation of the pressure-sensitive adhesive, thereby further enhancing its resistance to warping. In addition, anionic emulsifiers can also improve the wettability and penetration of the pressure-sensitive adhesive onto the surface of the adhered object, helping to form a stronger bonding interface. However, using a single emulsifier may lead to poor emulsion stability, affecting the performance of the pressure-sensitive adhesive. At the same time, allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate is highly polar, and excessive use may lead to a decrease in the wettability of the pressure-sensitive adhesive, affecting the initial tack performance.

[0029] Preferably, the tackifier is one or more of aqueous rosin tackifying emulsion and aqueous terpene tackifying emulsion; more preferably, it is aqueous rosin tackifying emulsion and aqueous terpene tackifying emulsion.

[0030] Preferably, the mass ratio of the aqueous rosin thickening emulsion to the aqueous terpene thickening emulsion is (1~3):1; more preferably, it is 2:1.

[0031] Preferably, the viscosity of the aqueous rosin thickening emulsion at room temperature is 100~400 mPa·s, the solid content is 55±2%, and the pH value is 6~8.

[0032] Preferably, the aqueous terpene thickening emulsion has a viscosity of 600~800 mPa·s at room temperature, a solid content of 60±2%, and a pH value of 6~8.

[0033] In some preferred embodiments, the aqueous rosin thickening emulsion and the aqueous terpene thickening emulsion are both purchased from Shenzhen Yoshida Chemical Co., Ltd., models 958 and 968.

[0034] Preferably, the amount of the thickener added is 2% to 3% of the monomer mass.

[0035] The inventors discovered that by selecting specific water-based rosin tackifying emulsions and water-based terpene tackifying emulsions as tackifiers, the anti-lifting effect of pressure-sensitive adhesives (PSAs) can be further improved, while also adjusting their solid content and viscosity. This is because the two water-based tackifying emulsions exhibit a significant synergistic effect. The active functional groups in rosin and terpene molecules can interact to form a more complex and stable cross-linked network structure. This structure not only enhances the cohesiveness and adhesion of the PSAs but also significantly improves its anti-lifting effect and weather resistance. Simultaneously, the synergistic effect of the two tackifying emulsions can effectively adjust the viscosity and solid content of the PSAs, allowing the final product to meet the needs of different applications. Furthermore, this synergistic effect can optimize the wettability and permeability of the PSAs, making it easier to form a good adhesive interface with the surface of the adherend, thereby further improving the bonding effect.

[0036] Preferably, the chain transfer agent is n-dodecyl mercaptan.

[0037] Preferably, the amount of chain transfer agent added is 0.05% to 0.1% of the monomer mass.

[0038] Preferably, the buffer is one or more of sodium bicarbonate, potassium carbonate, sodium carbonate, and ammonium bicarbonate; more preferably, it is sodium bicarbonate.

[0039] Preferably, the amount of buffer added is 0.05% to 0.1% of the monomer mass.

[0040] Preferably, the pH adjuster is one or more of ammonia, sodium hydroxide, ethanolamine, and ethylenediamine; more preferably, it is ammonia.

[0041] Preferably, the solvent is deionized water.

[0042] Preferably, the amount of solvent added is 55% to 60% of the monomer mass.

[0043] The method for preparing the battery label using water-based acrylic pressure-sensitive adhesive includes the following steps:

[0044] S1. Mix emulsifier, monomer, chain transfer agent and deionized water and stir for 1-2 hours to obtain liquid one;

[0045] S2. Divide the initiator into initiator one and initiator two, and prepare initiator two solution by taking initiator two and deionized water;

[0046] S3. Dissolve the buffer in deionized water to prepare a buffer solution. Stir until the buffer dissolves, then heat to 80-90℃. Add initiator one and continue stirring until dissolved. Simultaneously add liquid one and initiator two solutions dropwise over 3-4 hours. Keep the solution at 80-90℃ for 1-2 hours, then cool to 30-50℃. Add a thickener and continue stirring for 15-30 minutes. Add deionized water and a pH adjuster to adjust the pH of the system to 6-7, then continue stirring for 15-20 minutes. Filter to obtain the final product.

[0047] In the preparation of waterborne acrylic pressure-sensitive adhesives, the monomer dropping rate, reaction temperature, and water content are key factors affecting the adhesive's performance. Excessive dropping speed can lead to rapid polymerization and monomer residue, affecting the stability of the adhesive and the performance of the final product. The temperature must be controlled within a suitable range; too high a temperature can easily cause gelation, while too low a temperature will result in an excessively slow reaction rate. The water content directly affects the moisture content of the adhesive; too high a water content may cause delamination and sedimentation, while too low a water content may cause the coating to dry too quickly and crack. Therefore, strictly controlling these process parameters is crucial for obtaining high-performance, stable-quality waterborne acrylic pressure-sensitive adhesives.

[0048] Preferably, in step S1, the amount of deionized water added is 15% to 20% of the monomer mass.

[0049] Preferably, in step S2, the mass ratio of initiator one to initiator two is 1:(1~2); more preferably, it is 2:3.

[0050] Preferably, in step S2, the mass percentage of initiator two in the initiator two solution is 5% to 7%.

[0051] Preferably, in step S3, the mass percentage of the buffer in the buffer solution is 0.2% to 0.5%.

[0052] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0053] 1. This invention provides a water-based acrylic pressure-sensitive adhesive for battery labels. Through optimized formulation and polymerization process, its adhesion is significantly improved, ensuring a strong bond between the label and the battery casing. Simultaneously, this pressure-sensitive adhesive exhibits excellent bonding strength, maintaining a stable adhesion effect and effectively preventing label detachment. Furthermore, its excellent anti-peeling properties ensure that the label edges are not prone to peeling during long-term use, thereby improving the overall durability and aesthetics of the battery label. This provides battery manufacturers with a high-performance, environmentally friendly, and economical label adhesive solution.

[0054] 2. By selecting specific soft monomers, hard monomers, and crosslinking monomers, and adjusting the proportion of each component, this invention can improve the adhesive performance of pressure-sensitive adhesives while also improving their resistance to warping.

[0055] 3. By selecting specific reactive emulsifiers and anionic emulsifiers as emulsifiers, this invention can further improve the adhesive performance and anti-lifting effect of pressure-sensitive adhesives.

[0056] 4. By selecting specific water-based rosin tackifying emulsions and water-based terpene tackifying emulsions as tackifiers, this invention can further improve the anti-buckling effect of pressure-sensitive adhesives, while also adjusting their solid content and viscosity.

[0057] 5. In the process of preparing waterborne acrylic pressure-sensitive adhesive, the present invention adjusts the product performance of the pressure-sensitive adhesive by controlling the monomer dropping rate, reaction temperature and water ratio. Detailed Implementation

[0058] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] All raw materials used in this invention are commercially available, specifically:

[0060] Allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate, with an effective content of 95% and a viscosity of <35000cps at 25℃; allyloxynonylphenol propanol polyoxyethylene ether, with an effective content of 99% and a viscosity of <300cps at 25℃, an acid value of 0.07~0.09gKOH / g, a hydroxyl value of 73~75mgKOH / g, and an HLB value of 12.6; both were purchased from Guangzhou Shuangjian Trading Co., Ltd., DNS-86 and ANPEO10.

[0061] Alkylphenol polyoxyethylene ether, with a cloud point of 68~78℃, a hydroxyl value of 87±5mgKOH / g, and an HLB value of 13.3~14, was purchased from Haian Petrochemical Plant, Jiangsu Province, OP-10.

[0062] The water-based rosin thickening emulsion has a viscosity of 100~400 mPa·s at room temperature, a solid content of 55±2%, and a pH value of 6~8; the water-based terpene thickening emulsion has a viscosity of 600~800 mPa·s at room temperature, a solid content of 60±2%, and a pH value of 6~8; both were purchased from Shenzhen Yoshida Chemical Co., Ltd., models 958 and 968.

[0063] Example 1

[0064] This embodiment provides an aqueous acrylic pressure-sensitive adhesive for battery labels, the raw materials for which are monomers, initiators, emulsifiers, tackifiers, chain transfer agents, solvents, buffers, and pH adjusters.

[0065] The monomers are soft monomers, hard monomers, and crosslinking monomers, with a mass ratio of 95:4:2.

[0066] The soft monomer is butyl acrylate.

[0067] The hard monomer is styrene.

[0068] The crosslinking monomers are acrylic acid and hydroxyethyl methacrylate in a mass ratio of 1:3.

[0069] The initiator is ammonium persulfate, and the amount added is 0.4% of the monomer mass.

[0070] The emulsifier is a reactive emulsifier and an anionic emulsifier, with a mass ratio of 1:1.

[0071] The reactive emulsifier is ammonium sulfate of allyloxynonylphenol propanol polyoxyethylene (10) ether and allyloxynonylphenol propanol polyoxyethylene ether in a mass ratio of 2:1.

[0072] The anionic emulsifier is sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of 1:1.

[0073] The amount of emulsifier added is 4% of the monomer mass.

[0074] The tackifier is a water-based rosin tackifying emulsion and a water-based terpene tackifying emulsion in a mass ratio of 2:1.

[0075] The amount of the thickener added is 2.5% of the monomer mass.

[0076] The chain transfer agent is n-dodecyl mercaptan, and the amount added is 0.08% of the monomer mass.

[0077] The buffer is sodium bicarbonate, and the amount added is 0.08% of the monomer mass.

[0078] The pH adjuster is ammonia.

[0079] The solvent is deionized water.

[0080] The amount of solvent added is 58% of the monomer mass.

[0081] The method for preparing the battery label using water-based acrylic pressure-sensitive adhesive includes the following steps:

[0082] S1. Mix the emulsifier, monomer, chain transfer agent, and deionized water and stir for 1.5 hours to obtain liquid one;

[0083] S2. Divide the initiator into initiator one and initiator two, and prepare initiator two solution by taking initiator two and deionized water;

[0084] S3. Dissolve the buffer in deionized water to prepare a buffer solution. Stir until the buffer dissolves, then heat to 85°C. Add initiator one and continue stirring until dissolved. Simultaneously add liquid one and initiator two solutions dropwise over 3.5 hours. Keep the solution at 85°C for 1.5 hours, then cool to 40°C. Add a thickener and continue stirring for 20 minutes. Add deionized water and a pH adjuster to adjust the pH of the system to 6.5, then continue stirring for 18 minutes. Filter to obtain the final product.

[0085] In step S1, the amount of deionized water added is 18% of the monomer mass.

[0086] In step S2, the mass ratio of initiator one to initiator two is 2:3.

[0087] In step S2, the mass percentage of initiator two in the initiator two solution is 6%.

[0088] In step S3, the mass percentage of buffer in the buffer solution is 0.4%.

[0089] Example 2

[0090] The difference between this embodiment and Embodiment 1 is that the monomers are soft monomers, hard monomers, and crosslinking monomers in a mass ratio of 96:3:2.

[0091] Example 3

[0092] The difference between this embodiment and Embodiment 1 is that the mass ratio of the reactive emulsifier to the anionic emulsifier is 2:3.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 1 is that the monomers are soft monomers, hard monomers, and crosslinking monomers in a mass ratio of 98:2:1.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 1 is that the crosslinking monomer is acrylic acid.

[0097] Comparative Example 3

[0098] The difference between this comparative example and Example 1 is that the emulsifier used is a reactive emulsifier.

[0099] Comparative Example 4

[0100] The difference between this comparative example and Example 1 is that the reactive emulsifier is allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate.

[0101] Comparative Example 5

[0102] The difference between this comparative example and Example 1 is that the tackifier is an aqueous rosin tackifying emulsion.

[0103] Comparative Example 6

[0104] The difference between this comparative example and Example 1 is that the amount of the thickener added is 1% of the monomer mass.

[0105] Comparative Example 7

[0106] The difference between this comparative example and Example 1 is that the preparation method of the battery label using water-based acrylic pressure-sensitive adhesive includes the following steps:

[0107] S1. Mix the emulsifier, monomer, chain transfer agent, and deionized water and stir for 1.5 hours to obtain liquid one;

[0108] S2. Divide the initiator into initiator one and initiator two, and prepare initiator two solution by taking initiator two and deionized water;

[0109] S3. Dissolve the buffer in deionized water to prepare a buffer solution. Stir until the buffer dissolves, then heat to 85°C. Add initiator one and continue stirring until dissolved. Simultaneously, add liquid one and initiator two solutions dropwise over 2 hours. Keep the solution at 85°C for 1.5 hours, then cool to 40°C. Add a thickener and continue stirring for 20 minutes. Add deionized water and a pH adjuster to adjust the pH of the system to 6.5, then continue stirring for 18 minutes. Filter to obtain the final product.

[0110] Comparative Example 8

[0111] The difference between this comparative example and Example 1 is that the preparation method of the battery label using water-based acrylic pressure-sensitive adhesive includes the following steps:

[0112] S1. Mix the emulsifier, monomer, chain transfer agent, and deionized water and stir for 1.5 hours to obtain liquid one;

[0113] S2. Divide the initiator into initiator one and initiator two, and prepare initiator two solution by taking initiator two and deionized water;

[0114] S3. Dissolve the buffer in deionized water to prepare a buffer solution. Stir until the buffer dissolves, then heat to 85°C. Add initiator one and continue stirring until dissolved. Simultaneously add liquid one and initiator two solutions dropwise over 3.5 hours. Keep the solution at 100°C for 1.5 hours, then cool to 40°C. Add a thickener and continue stirring for 20 minutes. Add deionized water and a pH adjuster to adjust the pH of the system to 6.5, then continue stirring for 18 minutes. Filter to obtain the final product.

[0115] Performance testing

[0116] The initial tack was tested according to GB 4852-2002, with the ball number indicating the tack strength; the peel strength was tested according to GB / T 2792-1998; the holding power was tested according to GB / T 4851-1998, and the time it took for the ball to fall was recorded; the viscosity was tested according to GB / T 2794-1995, using a rotational viscometer under constant temperature conditions of 25℃; pressure-sensitive adhesive was applied to the battery label, which was then attached to the outside of a size 5 battery, and the peeling was observed after 7 days. The results are shown in Table 1.

[0117] Table 1 Test Results

[0118]

[0119] According to statistics, the water-based acrylic pressure-sensitive adhesive for battery labels prepared in Examples 1-3 of this invention has good initial tack, high peel strength, and excellent holding power, while also having a certain viscosity, so it will not lift when used for battery labels. Comparative Example 1 had too much soft monomer added, Comparative Example 2 did not add hydroxyethyl methacrylate crosslinking monomer, Comparative Example 3 did not add anionic emulsifier, Comparative Example 4 did not add allyloxynonylphenol propanol polyoxyethylene ether, resulting in excessive addition of allyloxynonylphenol propanol polyoxyethylene (10) ether ammonium sulfate, Comparative Example 5 did not add water-based terpene tackifying emulsion, Comparative Example 6 had too little tackifier added, Comparative Example 7 had too fast dropping acceleration, and Comparative Example 8 had too high reaction temperature. The resulting water-based acrylic pressure-sensitive adhesives for battery labels had poor adhesion and were prone to lifting. Therefore, the water-based acrylic pressure-sensitive adhesive prepared using the raw materials and methods described in this application not only has good initial tack, high peel strength, and excellent holding power, but also has a certain viscosity, so it will not lift when used for battery labels.

[0120] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a water-based acrylic pressure-sensitive adhesive for battery tags, characterized in that, Includes the following steps: S1. Mix emulsifier, monomer, chain transfer agent and deionized water and stir for 1-2 hours to obtain liquid one; S2. The initiator is divided into initiator one and initiator two, and initiator two and deionized water are used to prepare initiator two solution; wherein, the mass ratio of initiator one and initiator two is 1:(1~2); S3. Dissolve the buffer in deionized water to prepare a buffer solution. Stir until the buffer dissolves, then heat to 80-90℃. Add initiator one and continue stirring until dissolved. Simultaneously, add liquid one and initiator two solutions dropwise over 3-4 hours. Keep the solution at 80-90℃ for 1-2 hours, then cool to 30-50℃. Add a thickener and continue stirring for 15-30 minutes. Add deionized water and a pH adjuster to adjust the pH of the system to 6-7, then continue stirring for 15-20 minutes. Filter to obtain the final product. The raw materials for its preparation consist of monomers, initiators, emulsifiers, thickeners, chain transfer agents, solvents, buffers, and pH adjusters. The monomers are soft monomers, hard monomers, and crosslinking monomers in a mass ratio of (45~50):(1~3):1; the soft monomer is butyl acrylate, the hard monomer is styrene, and the crosslinking monomers are acrylic acid and hydroxyethyl methacrylate in a mass ratio of 1:(2~4). The initiator is one or both of ammonium persulfate and potassium persulfate, and the amount of initiator added is 0.3% to 0.5% of the monomer mass. The emulsifier is a reactive emulsifier and an anionic emulsifier with a mass ratio of 1:(0.5~2). The reactive emulsifier is ammonium allyloxynonylphenol propanol polyoxyethylene (10) ether sulfate and allyloxynonylphenol propanol polyoxyethylene ether with a mass ratio of 2:

1. The anionic emulsifier is sodium dodecyl sulfate and alkylphenol polyoxyethylene ether with a mass ratio of 1:(0.5~2). The amount of emulsifier added is 2%~5% of the monomer mass. The tackifier is a water-based rosin tackifying emulsion and a water-based terpene tackifying emulsion in a mass ratio of (1~3):1, and the amount of the tackifier added is 2%~3% of the monomer mass; The buffer is one or more of sodium bicarbonate, potassium carbonate, sodium carbonate, and ammonium bicarbonate, and the amount of the buffer added is 0.05% to 0.1% of the monomer mass. The pH adjuster is one or more of ammonia, sodium hydroxide, ethanolamine, and ethylenediamine; The chain transfer agent is n-dodecyl mercaptan, and the amount of chain transfer agent added is 0.05% to 0.1% of the monomer mass. The solvent is deionized water, and the amount of solvent added is 55% to 60% of the monomer mass.

2. The preparation method according to claim 1, characterized in that, The monomers are soft monomers, hard monomers, and crosslinking monomers in a mass ratio of 95:4:2; The crosslinking monomers are acrylic acid and hydroxyethyl methacrylate in a mass ratio of 1:

3.

3. The preparation method according to claim 1, characterized in that, The initiator is ammonium persulfate.

4. The preparation method according to claim 1, characterized in that, The emulsifier is a reactive emulsifier and an anionic emulsifier with a mass ratio of 1:1; The anionic emulsifier is sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of 1:

1.

5. The preparation method according to claim 1, characterized in that, The tackifier is a water-based rosin tackifying emulsion and a water-based terpene tackifying emulsion with a mass ratio of 2:1; The buffer is sodium bicarbonate; The pH adjuster is ammonia.

6. The preparation method according to claim 1, characterized in that, The aqueous rosin thickening emulsion has a viscosity of 100~400 mPa·s at room temperature, a solid content of 55±2%, and a pH value of 6~8.

7. The preparation method according to claim 1, characterized in that, The aqueous terpene thickening emulsion has a viscosity of 600~800 mPa·s at room temperature, a solid content of 60±2%, and a pH value of 6~8.

8. The preparation method according to claim 1, characterized in that, The mass ratio of initiator one to initiator two is 2:

3.

9. A water-based acrylic pressure-sensitive adhesive for battery labels, characterized in that, It is prepared by the method for preparing water-based acrylic pressure-sensitive adhesive for battery labels according to any one of claims 1 to 8.

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