Anhydrous ethanol-triggered quick debonding water-based adhesive and preparation method thereof

Abstract

The application discloses anhydrous ethanol-triggered quick debonding water-based adhesive and a preparation method thereof, and relates to the technical field of new materials.The water-based adhesive is prepared by microemulsion polymerization of acrylic acid, long-chain alkyl acrylate and short-chain alkyl acrylate in the presence of a reactive anion emulsifier, with water as a dispersion medium and a peroxide as an initiator, and has a glass transition temperature of-40 to-10 DEG C.The water-based adhesive is a water-based product free of benzene, halogen, formaldehyde, ammonia and nonylphenol, has excellent environmental protection, high bonding strength, good water resistance, and can be quickly debonded and free of residual glue after being in contact with anhydrous ethanol for 20-30 seconds, is easy to operate due to low viscosity, is stable in storage, and is suitable for fields such as packaging, labeling and electronic information industry.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, and in particular to an anhydrous ethanol-triggered rapid debonding aqueous adhesive and its preparation method. Background Technology

[0002] Polyacrylate adhesives, with their advantages of low cost, simple synthesis process, and excellent bonding and aging resistance, are widely used in packaging, labeling, and the electronics and information industry. Today, these fields not only require adhesives with good bonding strength but also demand rapid debonding. In packaging scenarios requiring temporary fixation or easy opening, such as food and pharmaceutical packaging, quick-release adhesives facilitate consumer access. For applications requiring frequent label changes or rapid label removal under specific conditions, such as logistics labels and promotional labels, quick-release adhesives prevent label residue, preserving the appearance and subsequent use of the product. In the production and assembly of electronic components, adhesives are sometimes used for temporary fixation or auxiliary processing, followed by rapid debonding for subsequent testing, repair, or disassembly. For example, in chip packaging and circuit board assembly, quick-release adhesives improve production efficiency and product repairability.

[0003] Currently, most easy-peel polyacrylate adhesives are solvent-based and typically require the addition of crosslinking agents to improve their holding power and peel strength. Solvent-based adhesives have high organic solvent content, posing safety hazards during production, use, and storage, and causing serious environmental pollution. With increasing environmental awareness, the environmental performance of adhesives is receiving more and more attention, making the development of easy-peel water-based polyacrylate adhesives essential. Emulsion-type acrylic adhesives use water as a dispersion medium, are easy to handle, and are environmentally friendly, but their bond strength and water resistance are relatively poor.

[0004] Therefore, it is of great significance to provide a water-based, non-chemically crosslinked polyacrylate adhesive with high bonding strength, good water resistance, environmental friendliness, and rapid debonding after contact with anhydrous ethanol. Summary of the Invention

[0005] The purpose of this invention is to provide an anhydrous ethanol-triggered rapid debonding aqueous adhesive and its preparation method, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides an anhydrous ethanol-triggered debonding aqueous adhesive, the raw materials comprising the following raw material components in the indicated mass ratios:

[0008] The mass ratio of short-chain alkyl acrylate, long-chain alkyl acrylate, acrylic acid, reactive anionic emulsifier, initiator and water is (10~50):(2~20):(1~10):(1~10):(0.05~1.0):100.

[0009] As a further preferred embodiment of the present invention, the mass ratio of the short-chain alkyl acrylate, long-chain alkyl acrylate, acrylic acid, reactive anionic emulsifier, initiator and water is (20~40):(5~15):(2~8):(2~8):(0.2~0.8):100.

[0010] As a further preferred embodiment of the present invention, the molecular formula of the short-chain alkyl acrylate is CH2=CHCOO(CH2). n CH3 or CH2=C(CH3)COO(CH2) n CH3, where n = 1~3.

[0011] As a further preferred embodiment of the present invention, the short-chain alkyl acrylate is one or more selected from ethyl acrylate, ethyl methacrylate, butyl acrylate, and butyl methacrylate. More preferably, it is butyl acrylate.

[0012] As a further preferred embodiment of the present invention, the molecular formula of the long-chain alkyl acrylate is CH2=CHCOO(CH2). n CH3 or CH2=C(CH3)COO(CH2) n CH3, where n = 5~15.

[0013] As a further preferred embodiment of the present invention, the long-chain alkyl acrylate is one or more selected from hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, and tetradecyl methacrylate. More preferably, it is dodecyl methacrylate.

[0014] As a further preferred embodiment of the present invention, the initiator comprises one or more of ammonium persulfate, potassium persulfate, and sodium persulfate. Potassium persulfate is more preferred.

[0015] As a further preferred embodiment of the present invention, the reactive anionic emulsifier is selected from one or more of allyl alcohol polyoxyethylene ether sulfate, alkenyl sulfonate, and allyl succinate alkyl ester sulfonate. More preferably, it is allyloxy alcohol polyoxyethylene ether sulfate, and even more preferably, it is allyloxynonylphenoxypropanol polyoxyethylene ether-10 ammonium sulfate (SR-10).

[0016] The waterborne adhesive with anhydrous ethanol-triggered debonding provided by this invention has a glass transition temperature of -40 to -10°C.

[0017] The waterborne polyacrylate adhesive of the present invention is a hydrophobic associative polymer obtained by microemulsion polymerization of short-chain alkyl acrylate, long-chain alkyl acrylate and acrylic acid in water with peroxide as an initiator in the presence of a reactive anionic emulsifier. It has low viscosity, high bonding strength and good water resistance, and can be rapidly debonded within 20 to 30 seconds when in contact with anhydrous ethanol.

[0018] The present invention also provides a method for preparing the above-mentioned anhydrous ethanol-triggered debonding aqueous adhesive, comprising the following steps:

[0019] The raw materials are microemulsion polymerized according to the mass ratio to obtain the anhydrous ethanol-triggered debonding aqueous adhesive.

[0020] As a further preferred embodiment of the present invention, during the preparation process, water, a reactive anionic emulsifier, short-chain alkyl acrylate, long-chain alkyl acrylate, and acrylic acid are first mixed to obtain a mixture; then an initiator solution is added to the mixture to react and obtain an anhydrous ethanol-triggered debonding aqueous adhesive.

[0021] As a further preferred embodiment of the present invention, the preparation method includes the following steps:

[0022] S1: Add reactive anionic emulsifier SR-10 to deionized water and magnetically stir at 10-30℃ for 20-60 min at a stirring speed of 100-500 rpm to obtain solution A;

[0023] S2: Add dodecyl methacrylate and butyl acrylate to solution A, and magnetically stir at 10 ~ 30℃ for 2 ~ 6 h. Then add acrylic acid and magnetically stir for 0.5 ~ 2 h until completely dissolved. The stirring speed is 100 ~ 500 rpm to obtain solution B.

[0024] S3: Add the initiator to deionized water and stir magnetically at 10~30℃ for 10~30 min at a stirring speed of 100~500 rpm to obtain solution C;

[0025] S4: Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 60-80℃ for 10-30 min at a stirring speed of 100-500 rpm.

[0026] S5: Slowly add the remaining solution B and solution C dropwise into the three-necked flask, and stir at 60 ~ 80℃ for 30 ~ 60 min at a stirring speed of 100 ~ 500 rpm, so that solution B and solution C are added dropwise at the same time to obtain solution D;

[0027] S6: Stir solution D at 60-90℃ for 20-60 min at a stirring speed of 50-300 rpm;

[0028] S7: Add NaHCO3 to solution D and adjust the pH value to 7.0-8.0 to obtain an aqueous polyacrylate adhesive, i.e., an aqueous adhesive that triggers debonding with anhydrous ethanol.

[0029] The present invention further provides the application of the above-mentioned anhydrous ethanol-triggered debonding aqueous adhesive in the fields of packaging, labeling or electronic information industry.

[0030] The water-based polyacrylate adhesive of this invention has low viscosity (< 60 mPa·s), good bonding strength and water resistance, and can quickly de-adhere within 20 to 30 seconds when in contact with anhydrous ethanol, leaving no residue. It is particularly suitable for packaging, labeling, and electronic information industries that require rapid de-adhesion.

[0031] The water-based polyacrylate adhesive provided by this invention is a water-based product that is free of benzene, halogen, formaldehyde, ammonia, and nonylphenol, making it environmentally friendly. Its preparation method is simple and easy to operate, and the adhesive itself has low viscosity, making it easy to apply and coat in subsequent use, resulting in high overall ease of use.

[0032] The waterborne polyacrylate adhesive of this invention is prepared by microemulsion polymerization of hydrophobic long-chain alkyl esters and short-chain alkyl esters of acrylic acid, functional monomer acrylic acid, and reactive emulsifier. By constructing hydrophobic associative microdomains, high adhesive strength and good water resistance are achieved. The hydrophobic long-chain alkyl side groups aggregate to form hydrophobic associative microdomains, which play a role in interfacial drainage at the adhesive-substrate interface. This rapidly breaks down the hydration layer between the waterborne polyacrylate adhesive and the substrate, promoting non-covalent interactions (such as hydrogen bonding, coordination, electrostatics, and dipole interactions) between the acrylic segments and the substrate surface. Simultaneously, the hydrophobic associative microdomains can also act as physical crosslinking points, improving the cohesive strength of the film after drying. Furthermore, the reactive emulsifier molecules are chemically bonded to the polyacrylate macromolecular chains, avoiding problems such as slow film formation, poor water resistance, and insufficient adhesion caused by the desorption of small emulsifier molecules from the polymer latex particle surface.

[0033] The waterborne polyacrylate adhesive of this invention has a non-covalent cross-linked structure with hydrophobic associating microdomains acting as physical cross-linking points. The strong hydrogen bonding between the ester and carboxyl groups on the polyacrylate copolymer molecular chain and anhydrous ethanol allows the anhydrous ethanol to rapidly diffuse to the adhesive-substrate interface, disrupting the non-covalent interactions between them and causing the adhesive film to quickly detach from the substrate surface. However, the hydrophobic associating microdomains in the adhesive film are not destroyed by the anhydrous ethanol, ensuring the integrity of the adhesive film during peeling. Based on this characteristic, when debonding is required, only a small amount of anhydrous ethanol needs to be added to the adhesive-substrate interface, and rapid debonding can be achieved after standing for 20-30 seconds, leaving no adhesive residue on the substrate surface after debonding.

[0034] The present invention discloses the following technical effects:

[0035] This invention utilizes a precise combination of three monomers—long-chain alkyl acrylate, short-chain alkyl acrylate, and acrylic acid—along with a reactive emulsifier, to prepare a non-covalently crosslinked waterborne polyacrylate adhesive via microemulsion polymerization. This adhesive, as a benzene-free, halogen-free, and formaldehyde-free water-based product, uses water as the dispersion medium, eliminating organic solvent pollution and meeting the requirements of green development. The reactive emulsifier chemically bonds to the macromolecular chain, avoiding problems such as slow film formation, poor water resistance, and insufficient adhesion caused by emulsifier desorption. The hydrophobic association of the long-chain alkyl side groups of the polyacrylate copolymer endows the adhesive with high cohesive strength and water resistance. The strong non-covalent interaction between the carboxyl groups on the molecular chain and the substrate surface gives the adhesive excellent bonding properties. Simultaneously, the strong hydrogen bonding between the ester and carboxyl groups in the molecular chain and anhydrous ethanol allows anhydrous ethanol to trigger interfacial debonding within 20-30 seconds, and the hydrophobic association ensures the integrity of the adhesive film after peeling, leaving no residue. The water-based polyacrylate adhesive of this invention has the characteristics of low viscosity, easy operation, and good storage stability, which meets the practical application requirements of packaging, electronics and other fields. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 The chemical structural formulas of the polyacrylate adhesives in Examples 1-4 are shown below.

[0038] Figure 2 The DSC curves are for the dried films of the polyacrylate adhesives in Examples 1-4.

[0039] Figure 3 The images show actual photos of the polyacrylate adhesives used in Examples 1-4. Detailed Implementation

[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0041] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0042] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0043] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0044] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0045] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0046] In the following embodiments of the present invention, unless otherwise specified, all operations are carried out at room temperature. Room temperature refers to "25±3℃".

[0047] All raw materials used in the embodiments of this invention were commercially available.

[0048] Acrylic acid, analytical grade, purchased from Zhiyuan Chemical Reagent Co., Ltd.; Dodecyl methacrylate, analytical grade, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Butyl acrylate, analytical grade, purchased from Shandong Keyuan Biochemical Co., Ltd.; Allyloxynonylphenoxypropanol polyoxyethylene ether-10 ammonium sulfate (SR-10), analytical grade, purchased from Shanghai Aladdin Biotechnology Co., Ltd.; Potassium persulfate, sodium persulfate, and ammonium persulfate, all analytical grade, purchased from Tianjin Damao Chemical Reagent Factory; Anhydrous ethanol, analytical grade, purchased from Zhiyuan Chemical Reagent Co., Ltd.

[0049] Example 1

[0050] A method for preparing an anhydrous ethanol-triggered debonding aqueous polyacrylate adhesive, comprising the following steps:

[0051] (1) Add 2.0 g of reactive anionic emulsifier SR-10 to 25 g of deionized water and stir magnetically at 25°C for 30 min at a stirring speed of 200 rpm to obtain solution A; add 3.0 g of dodecyl methacrylate and 10 g of butyl acrylate to solution A and stir magnetically at 25°C for 3 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 200 rpm;

[0052] (2) Add 100 mg of potassium persulfate initiator to 15 g of deionized water and stir magnetically at 25 °C for 10 min to obtain solution C. The stirring speed is 200 rpm.

[0053] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 70°C for 30 min at a stirring speed of 200 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 70°C for 60 min at a stirring speed of 200 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0054] (4) Stir solution D at 80°C for 60 min at a stirring speed of 150 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.0 to obtain water-based polyacrylate adhesive.

[0055] Example 2

[0056] A method for preparing an anhydrous ethanol-triggered debonding aqueous polyacrylate adhesive, comprising the following steps:

[0057] (1) 1.8 g of reactive anionic emulsifier SR-10 was added to 20 g of deionized water and magnetically stirred at 25°C for 40 min at a stirring speed of 150 rpm to obtain solution A; 3.5 g of dodecyl methacrylate and 12 g of butyl acrylate were added to solution A and magnetically stirred at 25°C for 4 h, then 2.0 g of acrylic acid was added and magnetically stirred for 1 h until completely dissolved to obtain solution B at a stirring speed of 150 rpm;

[0058] (2) Add 150 mg of sodium persulfate to 20 g of deionized water and stir magnetically at 25 °C for 20 min to obtain solution C. The stirring speed is 150 rpm.

[0059] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 75°C for 30 min at a stirring speed of 150 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 75°C for 60 min at a stirring speed of 150 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0060] (4) Stir solution D at 85°C for 30 min at a stirring speed of 150 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.5 to obtain water-based polyacrylate adhesive.

[0061] Example 3

[0062] A method for preparing an anhydrous ethanol-triggered debonding aqueous polyacrylate adhesive, comprising the following steps:

[0063] (1) 1.6 g of reactive anionic emulsifier SR-10 was added to 30 g of deionized water and magnetically stirred at 30°C for 20 min at a stirring speed of 300 rpm to obtain solution A; 4.0 g of dodecyl methacrylate and 16 g of butyl acrylate were added to solution A and magnetically stirred at 30°C for 4 h; then 2.5 g of acrylic acid was added and magnetically stirred for 1.5 h until completely dissolved to obtain solution B at a stirring speed of 300 rpm.

[0064] (2) Add 200 mg of ammonium persulfate to 10 g of deionized water and stir magnetically at 30°C for 30 min to obtain solution C. The stirring speed is 300 rpm.

[0065] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 65°C for 30 min at a stirring speed of 300 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 65°C for 50 min at a stirring speed of 300 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0066] (4) Stir solution D at 80°C for 60 min at a stirring speed of 300 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.0 to obtain water-based polyacrylate adhesive.

[0067] Example 4

[0068] A method for preparing an anhydrous ethanol-triggered debonding aqueous polyacrylate adhesive, comprising the following steps:

[0069] (1) Add 2.0 g of reactive anionic emulsifier SR-10 to 20 g of deionized water and stir magnetically at 15°C for 30 min at a stirring speed of 500 rpm to obtain solution A; add 5.0 g of dodecyl methacrylate and 14 g of butyl acrylate to solution A and stir magnetically at 15°C for 6 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 500 rpm;

[0070] (2) Add 100 mg potassium persulfate and 80 mg sodium persulfate to 20 g deionized water and stir magnetically at 15 °C for 30 min to obtain solution C. The stirring speed is 500 rpm.

[0071] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 80°C for 30 min at a stirring speed of 500 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 80°C for 60 min at a stirring speed of 250 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0072] (4) Stir solution D at 85°C for 60 min at a stirring speed of 250 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 8.0 to obtain water-based polyacrylate adhesive.

[0073] Figure 1 The chemical structural formulas of the polyacrylate adhesives in Examples 1-4 are shown below.

[0074] The performance of the water-based polyacrylate adhesives prepared in Examples 1-4 was tested:

[0075] 1. Glass transition temperature test:

[0076] The glass transition temperature of the dried polyacrylate adhesive sample was tested using a differential scanning calorimeter at a heating rate of 10 K / min, with a test temperature range of -60 to 100 °C, under nitrogen protection.

[0077] 2. Viscosity test: The viscosity of the water-based polyacrylate adhesive was tested according to GB / T 2794-1995 standard.

[0078] 3.180° Peel Strength Test: The test was conducted according to the GB / T 2792-2014 standard, which describes the test method for 180° peeling of adhesive tape from a steel plate. The adhesive layer thickness was approximately 30 μm.

[0079] Using a pipette, 2–3 mL of water-based polyacrylate adhesive was dropped onto the front side of a PET film measuring 100 mm in length and 25 mm in width. The adhesive was then spread evenly using a 30 μm coating rod and placed in a 60°C oven for 30 minutes to form an adhesive layer on the PET film surface. The PET adhesive tape was then bonded to a test steel plate, and the 180° peel strength was tested.

[0080] 4. Shear strength test: According to GB / T 7754-1987, the shear strength of the material is tested using a universal testing machine, with the adhesive layer thickness being approximately 0.2 mm.

[0081] 5. Water whitening resistance test: The PET tape sample coated with water-based polyacrylate adhesive was immersed in deionized water at room temperature (25℃), with the adhesive side facing down. The whitening of the adhesive film was observed at regular intervals, and the evaluation level is shown in Table 1.

[0082] Table 1 Evaluation Levels of Water Whitening

[0083]

[0084] 6. Anhydrous ethanol-triggered adhesive-substrate interface debonding test: According to GB / T 2792-2014 standard, PET adhesive tape coated with water-based polyacrylate adhesive was bonded to a test steel plate. Then, a small amount of anhydrous ethanol was dripped at the adhesive-steel plate interface. The free end of the PET tape was held with tweezers and the PET tape was gently peeled off from the steel plate. The residual adhesive on the steel plate surface was observed, and the time of adhesive debonding from the steel plate after contact with anhydrous ethanol was recorded.

[0085] Figure 2 The DSC curves of the polyacrylate adhesive films after drying in Examples 1-4 are shown (Examples 1-4 represent Examples 1-4 respectively).

[0086] Figure 3The images show actual photos of the polyacrylate adhesives used in Examples 1-4.

[0087] Table 2 Glass transition temperatures of each embodiment

[0088]

[0089] Table 3 Appearance, viscosity, and storage stability of each embodiment

[0090]

[0091] Table 4 Bond strength of each embodiment

[0092]

[0093] Table 5 Evaluation results of water whitening and anhydrous ethanol-triggered de-adhesion time for each embodiment

[0094]

[0095] Comparative Example 1

[0096] The amount of reactive anionic emulsifier SR-10 in Example 1 was reduced to 0.6 g, while the amount of other components added and the experimental operation steps were exactly the same as in Example 1. In the later stage of the polymerization reaction, the emulsion became unstable and severe aggregation occurred, making it impossible to successfully prepare waterborne polyacrylate adhesive.

[0097] The preparation steps are as follows:

[0098] (1) Add 0.6 g of reactive anionic emulsifier SR-10 to 25 g of deionized water and stir magnetically at 25°C for 30 min at a stirring speed of 200 rpm to obtain solution A; add 3.0 g of dodecyl methacrylate and 10 g of butyl acrylate to solution A and stir magnetically at 25°C for 3 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 200 rpm;

[0099] (2) Add 100 mg of potassium persulfate to 15 g of deionized water and stir magnetically at 25 °C for 10 min to obtain solution C. The stirring speed is 200 rpm.

[0100] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 70°C for 30 min at a stirring speed of 200 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 70°C for 60 min at a stirring speed of 200 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0101] (4) Stir the solution D at 80°C at a stirring speed of 150 rpm. After 10 min, the emulsion becomes unstable and severely aggregates, making it impossible to obtain water-based polyacrylate adhesive.

[0102] Comparative Example 2

[0103] The amount of dodecyl methacrylate in Example 1 was reduced to 1.8 g, while the amounts of other components and the experimental procedures were exactly the same as in Example 1. The prepared waterborne polyacrylate adhesive exhibited a 180° peel strength of 1.54 N / 25 mm with the test steel plate, and a water whitening rating of 4, indicating poor water resistance. The adhesive-steel plate interface debonded after 60 seconds of contact with anhydrous ethanol, leaving some adhesive residue on the test steel plate.

[0104] The preparation steps are as follows:

[0105] (1) Add 2.0 g of reactive anionic emulsifier SR-10 to 25 g of deionized water and stir magnetically at 25°C for 30 min at a stirring speed of 200 rpm to obtain solution A; add 1.8 g of dodecyl methacrylate and 10 g of butyl acrylate to solution A and stir magnetically at 25°C for 3 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 200 rpm;

[0106] (2) Add 100 mg of potassium persulfate to 15 g of deionized water and stir magnetically at 25 °C for 10 min to obtain solution C. The stirring speed is 200 rpm.

[0107] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 70°C for 30 min at a stirring speed of 200 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 70°C for 60 min at a stirring speed of 200 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0108] (4) Stir solution D at 80°C for 60 min at a stirring speed of 150 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.0 to obtain water-based polyacrylate adhesive.

[0109] Comparative Example 3

[0110] The reactive nonionic emulsifier ER-30 from Idico (Japan) was used instead of the reactive anionic emulsifier SR-10 in Example 1. The amounts of other components and the experimental procedures were exactly the same as in Example 1. The prepared waterborne polyacrylate adhesive showed a 180° peel strength of only 0.65 N / 25 mm to the test steel plate, with a water whitening rating of level 4, indicating poor water resistance. The adhesive-steel plate interface detached within 30 seconds of contact with anhydrous ethanol, but some adhesive residue remained on the test steel plate.

[0111] The preparation steps are as follows:

[0112] (1) Add 2.0 g of reactive nonionic emulsifier ER-30 to 25 g of deionized water and stir magnetically at 25°C for 30 min at a stirring speed of 200 rpm to obtain solution A; add 3.0 g of dodecyl methacrylate and 10 g of butyl acrylate to solution A and stir magnetically at 25°C for 3 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 200 rpm;

[0113] (2) Add 100 mg of potassium persulfate to 15 g of deionized water and stir magnetically at 25 °C for 10 min to obtain solution C. The stirring speed is 200 rpm.

[0114] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 70°C for 30 min at a stirring speed of 200 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 70°C for 60 min at a stirring speed of 200 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0115] (4) Stir solution D at 80°C for 60 min at a stirring speed of 150 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.0 to obtain water-based polyacrylate adhesive.

[0116] Comparative Example 4

[0117] Sodium dodecyl sulfate (SDS), a non-reactive anionic emulsifier, was used instead of the reactive anionic emulsifier SR-10 in Example 1. The amounts of other components added and the experimental procedures were exactly the same as in Example 1. The prepared waterborne polyacrylate adhesive exhibited a 180° peel strength of only 1.32 N / 25 mm from the test steel plate, with a water whitening rating of level 5, indicating very poor water resistance. The adhesive detached from the steel plate interface within 30 seconds of contact with anhydrous ethanol, but adhesive residue remained on the test steel plate.

[0118] The preparation steps are as follows:

[0119] (1) Add 2.0 g of non-reactive anionic emulsifier sodium dodecyl sulfate (SDS) to 25 g of deionized water and stir magnetically at 25 °C for 30 min at a stirring speed of 200 rpm to obtain solution A; add 3.0 g of dodecyl methacrylate and 10 g of butyl acrylate to solution A and stir magnetically at 25 °C for 3 h, then add 2.0 g of acrylic acid and stir magnetically for 1 h until completely dissolved to obtain solution B at a stirring speed of 200 rpm;

[0120] (2) Add 100 mg of potassium persulfate to 15 g of deionized water and stir magnetically at 25 °C for 10 min to obtain solution C. The stirring speed is 200 rpm.

[0121] (3) Add 5% solution B and 5% solution C to a three-necked flask, purge with nitrogen to remove oxygen, and stir at 70°C for 30 min at a stirring speed of 200 rpm; slowly add the remaining solution B and solution C dropwise to the three-necked flask, and stir at 70°C for 60 min at a stirring speed of 200 rpm, so that solution B and solution C are added at the same time to obtain solution D;

[0122] (4) Stir solution D at 80°C for 60 min at a stirring speed of 150 rpm; finally, add NaHCO3 to solution D and adjust the pH value to 7.0 to obtain water-based polyacrylate adhesive.

[0123] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A water-based adhesive with anhydrous ethanol-triggered debonding, characterized in that, The raw materials include the following components in the indicated mass proportions: The mass ratio of short-chain alkyl acrylate, long-chain alkyl acrylate, acrylic acid, reactive anionic emulsifier, initiator and water is (20~40):(5~15):(2~8):(2~8):(0.2~0.8):100; The molecular formula of the short-chain alkyl acrylate is CH2=CHCOO(CH2). n CH3 or CH2=C(CH3)COO(CH2) n CH3, where n = 1~3; The long-chain alkyl acrylate is one or more of dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, and tetradecyl methacrylate; The reactive anionic emulsifier is SR-10; The waterborne adhesive that triggers debonding with anhydrous ethanol is prepared by microemulsion polymerization.

2. The water-based adhesive with anhydrous ethanol-triggered debonding according to claim 1, characterized in that, The short-chain alkyl acrylate is one or more of ethyl acrylate, ethyl methacrylate, butyl acrylate, and butyl methacrylate.

3. The water-based adhesive with anhydrous ethanol-triggered debonding according to claim 1, characterized in that, The initiator includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate.

4. A method for preparing the aqueous adhesive with anhydrous ethanol-triggered debonding as described in any one of claims 1-3, comprising the following steps: The raw materials are microemulsion polymerized according to the mass ratio to obtain the anhydrous ethanol-triggered debonding aqueous adhesive.

5. The application of the anhydrous ethanol-triggered debonding aqueous adhesive as described in any one of claims 1-3 in the packaging, labeling, or electronic information industry.

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