Acrylic acid pressure-sensitive adhesive film with bidirectional electric control reversible adhesion function and preparation method of acrylic acid pressure-sensitive adhesive film

Abstract

The invention discloses an acrylic acid pressure-sensitive adhesive film with a bidirectional electric control reversible adhesion function and a preparation method thereof, and relates to the technical field of pressure-sensitive adhesive films. Comprising the following raw materials in parts by weight: 100 parts of acrylate copolymer masterbatch, 1.5-3 parts of a cross-linking agent, 0.1-0.3 part of an initiator, 5-8 parts of an ionic liquid, 2-5 parts of an ionic modifier, 0.1-0.5 part of graphene oxide, 1-3 parts of a polyvinylidene fluoride-trifluorochlor oethylene copolymer and 12-18 parts of a solvent. The acrylic acid pressure-sensitive adhesive film with the bidirectional electric control reversible adhesion function has good initial viscosity, cycling stability and bidirectional electric control use performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure-sensitive adhesive film, in particular to an acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function and a preparation method thereof. BACKGROUND

[0002] Pressure-sensitive adhesive is a kind of functional material that can produce adhesion under slight pressure and does not leave residue after removal, and is widely used in packaging, medical, electronic and aerospace fields. Traditional acrylic pressure-sensitive adhesive has the advantages of mature preparation process and good initial adhesion, but has the problems of irreversible adhesion and single function. When repeated pasting or position adjustment is required, traditional pressure-sensitive adhesive is often difficult to peel off due to strong adhesion, and even damages the surface of the adherend. In this situation, an acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function emerges as the times require, which has attracted widespread attention.

[0003] The acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function is a kind of material with special performance, which combines the excellent adhesive properties of acrylic pressure-sensitive adhesive and the intelligent characteristics of electrically controlled reversible adhesion, and can realize reversible switching of adhesion state under the action of external electric field. Current electrically controlled pressure-sensitive adhesive mainly relies on single ion migration or dielectrophoresis effect, resulting in narrow range of adhesion force change. It mainly realizes electrically controlled function by doping electrolyte, ionic liquid or conductive filler in the adhesive layer, which more or less has the defects of poor compatibility with the base adhesive of pressure-sensitive adhesive, long electrically controlled response time, limited adhesion force adjustment range, easy migration of ionic liquid directly blended, and electrically controlled failure after long-term use. On the other hand, in order to ensure the initial adhesion of pressure-sensitive adhesive, tackifying resins such as petroleum resin and rosin resin are often added in traditional formula, but such resins will hinder the formation of ion transmission channel, resulting in electrically controlled reversibility failure or poor cycle stability.

[0004] To solve the above problems, patent document CN120025765A discloses an electrolytic adhesive and its preparation method, and an electrolytic adhesive tape. The electrolytic adhesive of the invention comprises the following raw material components by weight fraction: 100 parts of adhesive main body, 2-10 parts of auxiliary agent and 300 parts of solvent; the adhesive main body contains anionic acrylate copolymer and cation. The electrolytic adhesive of the invention avoids additional addition of ionic liquid by adding anionic acrylate copolymer and imidazolium cation in the adhesive main body, thereby preventing migration of ionic liquid under high temperature and high humidity environment, and improving the weather resistance and moisture resistance of the electrolytic adhesive. The electrolytic adhesive performs well in improving the storage performance under high temperature and high humidity environment, and the adhesive force decreases less before power-on after experiencing high temperature and high humidity conditions. However, the invention realizes electrolytic adhesion function by the anionic acrylate copolymer itself carrying cations, although it avoids ionic liquid migration, but the chemical bonding effect of cations and polymer main chain significantly reduces the degree of freedom of ion migration, cannot form a continuous ion transmission channel, makes the electrically controlled response time long, the adhesive force adjustment range low, and it is difficult to meet the actual demand of fast adhesion-peeling. SUMMARY

[0005] The main purpose of the present application is to overcome the above-mentioned shortcomings, and to provide an acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function and a preparation method thereof. By optimizing the adhesive formulation system and preparation process, the rapid reversible adjustment of adhesion is realized, and good initial adhesion, cycle stability and bidirectional use performance are ensured.

[0006] To achieve the above purpose, the present application provides an acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function, which is made of the following raw materials in weight parts: 100 parts of acrylate copolymer masterbatch, 1.5-3 parts of crosslinking agent, 0.1-0.3 parts of initiator, 5-8 parts of ionic liquid, 2-5 parts of ionophilic modifier, 0.1-0.5 parts of graphene oxide, 1-3 parts of polyvinylidene fluoride-trifluorochloroethylene copolymer, and 12-18 parts of solvent.

[0007] Preferably, the solvent is a mixture of ethyl acetate and acetone in a mass ratio of 1:(1-2).

[0008] Preferably, the polyvinylidene fluoride-trifluorochloroethylene copolymer is polyvinylidene fluoride-trifluorochloroethylene copolymer powder solef 31508.

[0009] Preferably, the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm.

[0010] Preferably, the ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000.

[0011] Preferably, the ionic liquid is at least one of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

[0012] Preferably, the initiator is azobisisobutyronitrile.

[0013] Preferably, the crosslinking agent is HDI trimer curing agent.

[0014] Preferably, the preparation method of the acrylic ester copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75 DEG C for 5h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylic ester copolymer masterbatch with a glass transition temperature of -35 DEG C and a solid content of 40%.

[0015] Preferably, the mass ratio of butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate, and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0016] Another object of the present application is to provide a preparation method of the acrylic pressure-sensitive adhesive film with bidirectional electrically-controlled reversible adhesion, which comprises the following steps: uniformly mixing raw materials, passing through a 400-mesh sieve, coating on a 50-micron release film, drying to obtain the acrylic pressure-sensitive adhesive film with bidirectional electrically-controlled reversible adhesion.

[0017] Due to the use of the above technical solutions, the present application has the following beneficial effects: (1) The disclosed acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function realizes the bidirectional electrically controlled reversible adhesion function of the acrylic pressure-sensitive adhesive film for the first time by constructing a synergistic functional system of "ionic liquid-lyophilic modifier-oxidized graphene-polyvinylidene fluoride-trifluorochloroethylene copolymer". Among them, the ionic liquid provides the ion conduction basis for the electrically controlled response, the lyophilic modifier effectively improves the compatibility of the ionic liquid and the acrylate copolymer masterbatch, and avoids the response failure caused by phase separation; the oxidized graphene synchronously improves the conductivity and mechanical strength of the system by virtue of the single-layer two-dimensional structure, and the polyvinylidene fluoride-trifluorochloroethylene copolymer adjusts the interfacial interaction between the adhesive film and the adherend to cooperatively give the adhesive film the efficient switching ability of adhesion under the conditions of power on and power off. The combination of core components and the synergistic mechanism are not disclosed in the prior art, and the technical bottleneck that the single functional component of traditional electrically controlled adhesion material cannot realize bidirectional reversible control is broken through.

[0018] (2) The disclosed acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function, the monomer formula design of the acrylate copolymer masterbatch, by combining butyl acrylate, hydroxyethyl acrylate and methyl methacrylate in a specific ratio, and introducing 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 4-(phenylazo)phenyl methacrylate two kinds of functional monomers, not only accurately controls the glass transition temperature of the masterbatch to-35℃ and the solid content to 40%, ensures the basic adhesion and coating processability of the pressure-sensitive adhesive, but also through the multiple interactions of the ionic groups and azo groups in the functional monomers with the ionic liquid and oxidized graphene in the system, greatly improves the electrically controlled response sensitivity of the adhesive film, solves the technical problem that the basic adhesion and reversible control of the existing electrically controlled pressure-sensitive adhesive are difficult to be considered.

[0019] (3) The disclosed acrylic pressure-sensitive adhesive film with bidirectional electrically controlled reversible adhesion function, the preferred parameter design of each raw material solves the key technical pain points of the electrically controlled adhesion system: the solvent is a mixture of ethyl acetate and acetone in a ratio of 1:(1-2), which takes into account the solubility and evaporation rate to ensure uniform and defect-free film formation; the size and thickness control of single-layer oxidized graphene, the selection of polyethylene glycol monomethyl ether acrylate (number average molecular weight 1000), the selection of a specific type of ionic liquid (1-butyl-3-methyl imidazole bis-trifluoromethyl sulfonimide salt, etc.), and the accurate proportioning of HDI trimer crosslinking agent and azobisisobutyronitrile initiator, together optimize the ion migration efficiency, interfacial bonding strength and microstructure stability of the system, so that the adhesive film has a wider adhesion control range (bidirectional reversible switching effect is significant) and faster response speed under electrically controlled conditions, overcoming the defects of low control precision and response lag in the prior art. DETAILED DESCRIPTION

[0020] The following description is provided to enable any person skilled in the art to practice the present application as claimed. The preferred embodiments disclosed herein are only examples of the present application and alternative embodiments will be apparent to those skilled in the art upon reading the present disclosure. Embodiment 1

[0021] An acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function is prepared by mixing the following ingredients: 100 parts of acrylic ester copolymer masterbatch, 1.5 parts of crosslinking agent, 0.1 part of initiator, 5 parts of ionic liquid, 2 parts of ionophilic modifier, 0.1 part of graphene oxide, 1 part of polyvinylidene fluoride-chlorotrifluoroethylene copolymer, and 12 parts of solvent.

[0022] The solvent is a mixture of ethyl acetate and acetone in a mass ratio of 1:1; the polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508; the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm; the ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000; the ionic liquid is 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide; the initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

[0023] The preparation method of the acrylic ester copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75°C for 5 h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylic ester copolymer masterbatch with a glass transition temperature of -35°C and a solid content of 40%; the mass ratio of butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate, and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0024] A preparation method of the acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function comprises the following steps: mixing the ingredients uniformly, passing through a 400-mesh sieve, coating on a 50-μm release film with a glue thickness of 50 μm, and drying (60°C×3 min→80°C×5 min→100°C×2 min) to obtain the acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function. Embodiment 2

[0025] An acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function is prepared from the following raw materials in parts by weight: 100 parts of an acrylic ester copolymer masterbatch, 2 parts of a crosslinking agent, 0.15 parts of an initiator, 6 parts of an ionic liquid, 3 parts of a lyophilic ion modifier, 0.2 parts of graphene oxide, 1.5 parts of a polyvinylidene fluoride-chlorotrifluoroethylene copolymer, and 14 parts of a solvent.

[0026] The solvent is a mixture of ethyl acetate and acetone in a mass ratio of 1:1.3; the polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508; the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm; the lyophilic ion modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000; the ionic liquid is 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonimide; the initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

[0027] The preparation method of the acrylic ester copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75°C for 5 h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylic ester copolymer masterbatch with a glass transition temperature of -35°C and a solid content of 40%; the mass ratio of butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate, and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0028] A preparation method of the acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function comprises the following steps: uniformly mixing the raw materials, passing them through a 400-mesh sieve, coating them on a 50-μm release film, drying them (60°C×3 min→80°C×5 min→100°C×2 min), and obtaining the acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function. Example 3

[0029] An acrylic pressure sensitive adhesive film with bidirectional electrically controlled reversible adhesion function is prepared from the following raw materials in parts by weight: 100 parts of an acrylic ester copolymer masterbatch, 2.3 parts of a crosslinking agent, 0.2 parts of an initiator, 6.5 parts of an ionic liquid, 3.5 parts of a lyophilic ion modifier, 0.35 parts of graphene oxide, 2 parts of a polyvinylidene fluoride-chlorotrifluoroethylene copolymer, and 15 parts of a solvent.

[0030] The solvent is ethyl acetate and acetone mixed in a mass ratio of 1:1.5; the polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508; the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm; the ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000; the ionic liquid is 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide; the initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

[0031] The preparation method of the acrylate copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75°C for 5 h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylate copolymer masterbatch with a glass transition temperature of -35°C and a solid content of 40%; the mass ratio of butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0032] A preparation method of the acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function, comprising the following steps: uniformly mixing raw materials, passing through a 400-mesh sieve, coating on a 50-μm release film, with a glue thickness of 50 microns, drying (60°C×3 min→80°C×5 min→100°C×2 min), to obtain an acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function. Example 4

[0033] An acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function, comprising the following raw materials made in parts by weight: acrylate copolymer masterbatch 100 parts, crosslinking agent 2.8 parts, initiator 0.25 parts, ionic liquid 7.5 parts, ionophilic modifier 4.5 parts, graphene oxide 0.4 parts, polyvinylidene fluoride-chlorotrifluoroethylene copolymer 2.5 parts, and solvent 17 parts.

[0034] The solvent is ethyl acetate and acetone mixed in a mass ratio of 1:1.8; the polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508; the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm; the ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000; the ionic liquid is 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide salt and 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonimide salt mixed in a mass ratio of 1:3; the initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

[0035] The preparation method of the acrylate copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75°C for 5h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylate copolymer masterbatch with a glass transition temperature of -35°C and a solid content of 40%; the mass ratio of butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0036] A preparation method of the acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function, comprising the following steps: uniformly mixing raw materials, passing through a 400-mesh sieve, coating on a 50-μm release film, with a glue thickness of 50 microns, drying (60°C×3min→80°C×5min→100°C×2min), to obtain an acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function. Example 5

[0037] An acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function, comprising the following raw materials made in parts by weight: acrylate copolymer masterbatch 100 parts, crosslinking agent 3 parts, initiator 0.3 parts, ionic liquid 8 parts, ionophilic modifier 5 parts, graphene oxide 0.5 parts, polyvinylidene fluoride-chlorotrifluoroethylene copolymer 3 parts, and solvent 18 parts.

[0038] The solvent is ethyl acetate and acetone mixed in a mass ratio of 1:2; the polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508; the graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm; the ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000; the ionic liquid is 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide; the initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

[0039] The preparation method of the acrylate copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and performing solution polymerization in an ethyl acetate solvent under a nitrogen atmosphere at 75°C for 5 h to obtain an acrylate copolymer masterbatch with a glass transition temperature of -35°C and a solid content of 40%; the mass ratio of the butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate and azobisisobutyronitrile is 75:8:17:3:5:0.4.

[0040] A preparation method of the acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion comprises the following steps: uniformly mixing raw materials, passing through a 400-mesh sieve, coating on a 50-μm release film, drying (60°C×3 min→80°C×5 min→100°C×2 min), and obtaining the acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion.

[0041] Comparative Example 1 An acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion and a preparation method thereof are basically the same as those of Example 1, except that no polyvinylidene fluoride-chlorotrifluoroethylene copolymer is added.

[0042] Comparative Example 2 An acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion and a preparation method thereof are basically the same as those of Example 1, except that no 4-(phenylazo)phenyl methacrylate is added.

[0043] To further illustrate the beneficial technical effects of the acrylic pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function involved in various embodiments of the present application, the acrylic pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function involved in Example 1 and Comparative Examples 1-2 was subjected to relevant performance tests, and the test results are shown in Table 1, and the test methods are as follows: (1) 180° peeling strength: The 180° peeling strength between the film and a stainless steel plate was tested according to GB / T 2792-2014; test conditions: temperature 23±2°C, relative humidity 50±5%, and tensile speed 300 mm / min; then the 180° peeling strength after debonding was tested, and the debonding conditions were as follows: 6V direct current voltage was applied for 40s, and then 9V direct current voltage was applied for 20s.

[0044] (2) Reversible cycle test: In the same test position, 0V and 9V direct current electric field were applied alternately, each condition was maintained for 2 minutes, and the 180° peeling strength at 0V after 50 cycles was tested, and the retention rate was calculated.

[0045] (3) Durability test: Each sample was placed in an environment of 85°C and 85% relative humidity for 500 hours, the 180° peeling strength was tested, and the retention rate was calculated.

[0046] Table 1 Performance test results of the acrylic pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function Item Units Example 1 Comparative Example 1 Comparative Example 2 180° Peel Strength N / cm 5.8 5.0 4.2 180° Peel Strength after Debonding N / cm 0.004 0.012 0.028 Reversible Cycling Performance % 97.8 84.6 70.1 Durability % 94.3 88.4 76.2 As can be seen from the performance test results in Table 1, the acrylic pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function of Example 1 is significantly superior to Comparative Example 1 (lacking polyvinylidene fluoride-chlorotrifluoroethylene copolymer) and Comparative Example 2 (lacking 4-(phenylazo) phenyl methacrylate) in terms of key performances: the initial 180° peeling strength reaches 5.8 N / cm, which is higher than that of the two comparative groups, showing excellent initial adhesion performance; the 180° peeling strength after debonding is only 0.004 N / cm, which is much lower than that of Comparative Example 1 (0.012 N / cm) and Comparative Example 2 (0.028 N / cm), and the electrically controllable debonding effect is more thorough; the performance retention rate after 50 reversible cycle tests reaches 97.8%, and the durability retention rate after being placed in an environment of 85°C and 85% relative humidity for 500 hours reaches 94.3%, both of which are much higher than those of the two comparative groups, showing excellent cycle stability and moisture resistance and heat resistance. The above results show that the synergistic effect of polyvinylidene fluoride-chlorotrifluoroethylene copolymer and 4-(phenylazo) phenyl methacrylate effectively improves the comprehensive performance of the acrylic pressure-sensitive adhesive film in bidirectional electrically controllable reversible adhesion, providing a reliable guarantee for its practical application.

[0047] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only the principles of the present application. Various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. An acrylic pressure sensitive adhesive film having a bidirectional electrically controlled reversible adhesion function, characterized by, The preparation comprises the following raw materials by weight parts: acrylate copolymer masterbatch 100 parts, crosslinking agent 1.5-3 parts, initiator 0.1-0.3 parts, ionic liquid 5-8 parts, ionophilic modifier 2-5 parts, graphene oxide 0.1-0.5 parts, polyvinylidene fluoride-chlorotrifluoroethylene copolymer 1-3 parts, solvent 12-18 parts.

2. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The solvent is a mixture of ethyl acetate and acetone in a mass ratio of 1: (1-2).

3. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The polyvinylidene fluoride-chlorotrifluoroethylene copolymer is polyvinylidene fluoride-chlorotrifluoroethylene copolymer powder solef 31508.

4. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The graphene oxide is single-layer graphene oxide with a thickness of ≤5 nm and a flake diameter of 10 μm.

5. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The ionophilic modifier is polyethylene glycol monomethyl ether acrylate with a number average molecular weight of 1000.

6. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The ionic liquid is at least one of 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide and 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonimide.

7. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The initiator is azobisisobutyronitrile; and the crosslinking agent is HDI trimer curing agent.

8. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 1, characterized in that, The preparation method of the acrylate copolymer masterbatch comprises the following steps: mixing butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt and 4-(phenylazo)phenyl methacrylate, adding azobisisobutyronitrile, and solution polymerizing at 75 DEG C for 5 h in an ethyl acetate solvent under a nitrogen atmosphere to obtain an acrylate copolymer masterbatch with a glass transition temperature of -35 DEG C and a solid content of 40%.

9. The acrylic pressure sensitive adhesive film with bidirectional electrically controllable reversible adhesive function according to claim 8, characterized in that, The mass ratio of the butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 4-(phenylazo)phenyl methacrylate and azobisisobutyronitrile is 75:8:17:3:5:0.

4.

10. A method for preparing the acrylic pressure sensitive adhesive film having bidirectional electrically controllable reversible adhesive function according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: uniformly mixing the raw materials, passing them through a 400-mesh sieve, coating them on a 50-μm release film with a glue thickness of 50 microns, and drying to obtain an acrylate pressure-sensitive adhesive film with bidirectional electrically controllable reversible adhesion function.