Self-repairing glue for adhesive tape capable of realizing repeated stripping and re-pasting

Abstract

The invention discloses a self-repairing glue used for an adhesive tape and capable of being peeled off for multiple times and re-adhered, and the glue comprises the following components: (a) a bottom glue formula which accounts for 60-70% of the total mass of the glue and comprises a matrix polymer which is selected from thermoplastic polyurethane and has a molecular weight range of 80,000-120,000; the dynamic cross-linking agent accounts for 10-15% of the bottom layer formula and comprises a compound which is based on Diels-Alder reaction and is rich in furan groups and maleimide groups; the tackifier accounts for 8-12% of the bottom layer formula and is selected from polyacrylic acid; the nanometer self-repairing filler accounts for 5-8% of the bottom layer formula and is selected from nanometer silicon dioxide; through comprehensive application of a double-layer glue gradient design, a dynamic cross-linked network and an anti-residue additive, the excellent performance of repeated stripping and re-sticking is realized, and the self-repairing adhesive tape has the characteristics of self-repairing capability and no residual stripping, and can be widely applied to the fields of industrial assembly, household fixation, electronic screen protection, medical patches, environment-friendly packaging and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a self-repairing glue for an adhesive tape that can be peeled off and re-adhered multiple times. Background Art

[0002] Currently, glue is a widely used bonding material in industry, household and medical fields. Its performance directly determines the use effect of products such as tapes, protective films and patches. However, traditional glue still has many technical bottlenecks in actual use and is difficult to meet the modern multi-scenario, high-performance application requirements.

[0003] 1. Problems with the use of traditional glue

[0004] Peeling and residue issues: Traditional glues are mostly single viscosity, which cannot take into account both peeling and adhesion performance. Glue marks are easily left when peeling, especially on smooth or sensitive surfaces (such as glass, plastic, and electronic screens), affecting the appearance and function. The residual glue is difficult to remove after peeling, which increases the extra cleaning cost and limits the usage scenarios.

[0005] Non-reusable: Most glues lose their stickiness after being peeled off once, making tapes, protective films and other products disposable consumables that cannot meet application scenarios that require frequent adjustments and multiple uses. The performance decays quickly, making it difficult to play a long-term role in industrial assembly, temporary fixation or repeated packaging sealing.

[0006] Lack of self-repairing properties: After being peeled or damaged, the molecular structure of traditional glue is destroyed and cannot be restored, resulting in decreased adhesion or failure. Glue without self-repairing ability accumulates micro-damage during repeated use, shortening its service life and increasing material waste.

[0007] 2. Environmental protection and economic issues

[0008] Disposable tapes, protective films and other products use a lot of traditional glue, which wastes resources and increases environmental pollution. The non-reusable nature of glue exacerbates waste and cannot meet the needs of modern society for environmental protection and sustainable development.

[0009] 3. Limitations of existing improvement technologies

[0010] Some improved glues on the market have introduced dynamic cross-linking agents or anti-residue ingredients, but they usually only address a single problem and lack comprehensive performance improvements: Dynamic cross-linking glues are mainly used to improve durability, but the cleanability after peeling is still poor. Low-viscosity anti-residue glues are mostly used for short-term fixation, lack viscosity and do not have the characteristics of multiple uses. Wide-temperature range glues have improved environmental adaptability, but their use scenarios are limited and it is difficult to meet diverse performance requirements in high-precision and repeated use needs.

[0011] Glues and tapes that can be peeled and re-applied multiple times while maintaining stable adhesion are used in the following applications:

[0012] 1. Reusable industrial and household fixing tape

[0013] Parts that need to be temporarily fixed or adjusted multiple times during industrial assembly (such as electronic component installation, precision machinery assembly). In the home, it is used for traceless hooks, wall decoration, temporary fixing of objects, etc.

[0014] 2. High-performance electronic screen protector

[0015] Reusable protective film for mobile phones, tablets and laptop screens.

[0016] 3. Medical supplies

[0017] Medical patches such as Band-Aids and medical sensor patches that require repeated position adjustment.

[0018] 4. Resealable and environmentally friendly packaging

[0019] Sealing tape for food bags and logistics packaging boxes, users can open and close the packaging multiple times.

[0020] 5. Adjustable accessories and personalized stickers

[0021] Re-stickable brooches, decorative stickers, temporary clothing appliques.

[0022] It can be seen that glue and tape that can achieve multiple peeling and re-pasting while maintaining stable adhesion performance have great uses, but the current existing technology is still blank in this regard. Summary of the invention

[0023] The purpose of the present invention is: The present invention aims to provide a self-repairing glue for tape that can be peeled off and re-adhered multiple times, a self-repairing glue that successfully solves the above-mentioned technical problems through the comprehensive application of double-layer glue gradient design, dynamic cross-linking network and anti-residue additives, and significantly improves the adaptability and performance of multiple scenarios.

[0024] The technical solution adopted by the present invention is as follows:

[0025] A self-repairing glue for adhesive tape that can be peeled off and re-adhered multiple times, the glue comprising the following components:

[0026] (a) The base glue formula, accounting for 60-70% of the total glue mass, includes:

[0027] A base polymer selected from thermoplastic polyurethanes having a molecular weight range of 80,000-120,000;

[0028] Dynamic crosslinkers, accounting for 10-15% of the base layer formulation, include compounds rich in furan groups and maleimide groups based on the Diels-Alder reaction;

[0029] A tackifier, accounting for 8-12% of the base layer formulation, selected from polyacrylic acid;

[0030] Nano self-healing filler, accounting for 5-8% of the base layer formula, selected from nano silicon dioxide;

[0031] (b) Surface glue formula, accounting for 30-40% of the total glue mass, including:

[0032] A base polymer selected from functionalized polydimethylsiloxane having a molecular weight range of 50,000-100,000;

[0033] Dynamic crosslinkers, which make up 5-8% of the skin layer formulation, include hydrogen bonding aids;

[0034] Anti-residue additive, accounting for 3-5% of the surface layer formulation, selected from fluoropolymers or siloxane oligomers;

[0035] A tackifier, accounting for 3-5% of the surface layer formulation, is selected from polyvinyl alcohol;

[0036] (c) Solvents or regulators, accounting for 5-10% of the total mass of the glue, including ionic liquids or other compounds that can enhance the fluidity of the material.

[0037] The viscosity of the bottom layer glue is in the range of 10,000-15,000 mPa·s, and the viscosity of the surface layer glue is in the range of 5,000-8,000 mPa·s, so as to form a viscosity gradient.

[0038] Wherein, the molar ratio of the furan group to the maleimide group of the dynamic crosslinking agent is 1:1.

[0039] The anti-residue additive can migrate to the glue surface during the peeling process, reduce adhesion and prevent residue.

[0040] Wherein, the particle size of the nano self-repairing filler is 10-50 nanometers.

[0041] An adhesive tape that can be peeled off and re-adhered multiple times and prepared using the self-repairing glue, the adhesive tape comprising:

[0042] (a) a tape substrate, selected from a PET film or an OPP film, having a surface having a microstructure, including micro protrusions or micro grooves;

[0043] (b) A double layer of self-healing glue is sequentially coated on the substrate, wherein the thickness of the bottom layer of glue is 10-20 μm and the thickness of the surface layer of glue is 5-10 μm.

[0044] Among them, the double-layer glue adopts a gradient design of a dynamic cross-linking agent so that the bottom layer provides the main adhesion performance, while the surface layer is easy to peel off and reduces residue; after the self-healing glue layer is peeled off by external force, it can achieve self-repair at room temperature through reconstruction of the dynamic cross-linking agent; the tape can maintain more than 90% of the initial adhesion after ≥100 peeling and re-pasting operations.

[0045] A method for preparing the self-repairing glue comprises the following steps:

[0046] (a) heating the base glue matrix polymer to a softened state at 60-80° C.;

[0047] (b) adding a bottom layer dynamic crosslinking agent, a nano self-healing filler and a tackifier, and stirring evenly to form a bottom layer glue;

[0048] (c) coating a base layer of glue on the tape substrate and curing the base layer to a thickness of 10-20 μm;

[0049] (d) heating the surface glue matrix polymer to a fluid state;

[0050] (e) adding a surface dynamic crosslinking agent, an anti-residue additive and a tackifier, and stirring evenly to form a surface glue;

[0051] (f) Apply the top layer of glue to the bottom surface and cure it to a thickness of 5-10 microns.

[0052] Among them, the dynamic cross-linking agent of the bottom layer glue is mixed by high-speed shear to ensure uniform dispersion and enhance the high adhesion performance of the bottom layer; the anti-residue additive of the surface layer glue is dispersed by ultrasonic-assisted technology during the stirring process to improve the anti-residue performance during peeling.

[0053] In the curing process of the bottom layer and the surface layer, ultraviolet light can be selectively introduced to assist in curing, so as to further improve the weather resistance and peeling performance of the surface layer.

[0054] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0055] 1. The gradient design of the double-layer glue enables multiple peeling and re-sticking

[0056] Traditional glues mostly have a single viscosity, which makes it difficult to balance peeling performance and adhesion performance, resulting in serious residue during peeling or loss of viscosity after repeated use. The present invention adopts a gradient design of double-layer glue, the bottom layer glue has a high viscosity to provide the main adhesion performance, and the surface layer glue has a low viscosity to reduce the peeling resistance. Anti-residue additives are introduced into the surface glue, and the additives migrate to the surface of the glue during peeling to further reduce residue. Thereby, the peeling convenience is significantly improved, and there is no obvious residue after peeling. After multiple peelings, the bottom layer glue maintains adhesion performance, ensuring stability in repeated use scenarios.

[0057] 2. Dynamic cross-linking network gives glue self-healing ability

[0058] Ordinary glue cannot be restored after peeling or damage, and its performance degrades seriously after long-term use. The bottom layer glue of the present invention introduces a dynamic crosslinking agent (furan group and maleimide group) based on the Diels-Alder reaction, and the surface layer glue introduces a hydrogen bonding auxiliary agent (urea group), and the chemical bonds are rebuilt after the molecules are broken through the dynamic crosslinking network. Nanofillers (silicon dioxide with a particle size of 10-50 nanometers) improve the migration ability of molecular chains and accelerate the repair process of broken parts. Therefore, after peeling, the glue can spontaneously repair the broken area through the dynamic crosslinking network at room temperature without the need for additional energy drive. It achieves high durability for repeated peeling and pasting, and can still maintain more than 90% of the initial adhesion after multiple uses.

[0059] 3. Anti-residue properties achieve peeling and cleaning

[0060] After ordinary glue is peeled off, sticky substances remain on the surface of the object, affecting the appearance and function, especially on smooth or sensitive surfaces. In the present invention, an anti-residue additive (fluorinated polymer or siloxane oligomer) is specially added to the surface glue, and the additive is dispersed by ultrasound-assisted technology to ensure its uniform distribution. During peeling, the additive migrates to the surface of the glue, effectively reducing the adhesion and preventing residue. Therefore, the surface of the object remains clean after peeling, which is particularly suitable for smooth or sensitive materials such as glass and plastic.

[0061] 4. Environmental adaptability broadens application scenarios

[0062] Ordinary glues lose performance in extreme temperatures or high humidity environments and are difficult to use in wide temperature ranges. Thermoplastic polyurethane (TPU) and functionalized polydimethylsiloxane (PDMS) are used as base polymers in the glue of the present invention to ensure that the glue has stable performance in the range of -40°C to 120°C. The weather resistance and peeling properties of the glue are enhanced through ultraviolet-assisted curing process. The glue is suitable for a variety of extreme environments (such as low-temperature refrigeration or high-temperature industrial scenarios) to meet the needs of multiple fields such as home, industry and medical care.

[0063] 5. Process optimization improves product consistency

[0064] The present invention significantly improves the reusability, peeling convenience and environmental adaptability of the glue through a double-layer gradient design, a dynamic cross-linking network, a self-healing function and anti-residue properties, solves the main pain points in the prior art, and has broad application prospects and significant technical advantages.

[0065] The present invention achieves the excellent performance of multiple peeling and re-pasting through the comprehensive application of double-layer glue gradient design, dynamic cross-linking network and anti-residue additives. It has self-repairing ability and residue-free peeling characteristics, and can be widely used in industrial assembly, home fixation, electronic screen protection, medical patches, environmentally friendly packaging and other fields. It significantly improves the ease of use, durability and environmental protection, and solves the problems of residue, non-reusability and performance attenuation after traditional glue peeling, showing excellent technical advantages and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a process schematic diagram of the glue of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0068] See also Figure 1 The present invention relates to a self-repairing glue for adhesive tape that can be peeled off and re-adhered multiple times, and the glue comprises the following components:

[0069] (a) The base glue formula, accounting for 60-70% of the total glue mass, includes:

[0070] The matrix polymer is selected from thermoplastic polyurethane (TPU) with a molecular weight range of 80,000-120,000; it provides structural support and adhesion basis. TPU is composed of flexible segments (such as polyether or polyester) and rigid segments (such as diisocyanate polymers). The flexible segments provide higher elasticity and reversible deformation ability, while the rigid segments form a certain degree of physical cross-linking to enhance strength. When the tape is applied to the surface of the adherend, the flexible segments can fully contact the surface and increase the adhesion area. During the peeling process, the flexible segments provide reversible deformation to absorb the peeling energy, while the rigid segments maintain the structural integrity of the cross-linked network to avoid permanent damage.

[0071] Dynamic crosslinkers, accounting for 10-15% of the bottom layer formula, include compounds rich in furan groups and maleimide groups based on the Diels-Alder reaction; the molar ratio of furan groups to maleimide groups in the dynamic crosslinker is 1:1; providing recovery ability after peeling, the furan groups and maleimide groups in the crosslinker form reversible covalent bonds through the Diels-Alder reaction: furan groups + maleimide groups → Diels-Alder covalent bonds; during the peeling process, local stress causes the crosslinks to break (reverse Diels-Alder reaction), and the broken reactants can spontaneously re-react at room temperature (Diels-Alder reaction) to restore the crosslinked network. In the adhered state, the Diels-Alder reaction provides high-strength adhesion. During the peeling process, the crosslinks are broken rather than destroyed as a whole, avoiding permanent viscosity loss. After the peeling is completed, the crosslinks are spontaneously rebuilt to restore the adhesive properties of the glue.

[0072] The tackifier, which accounts for 8-12% of the base layer formula, is selected from polyacrylic acid (PAA); it improves the initial adhesion performance. Polyacrylic acid is a polar polymer, and its carboxyl group (-COOH) can form hydrogen bonds and van der Waals forces with the surface of the adherend. The tackifier improves the initial adhesion between the base glue and the adherend, and at the same time enhances the interfacial bonding strength of the dynamic cross-linking network. During the peeling process, the polarity of the tackifier slows down the peeling speed, ensuring the stability of the adhesion performance.

[0073] Nano self-healing fillers, accounting for 5-8% of the base layer formula, are selected from nano-silicon dioxide; the particle size of the nano self-healing fillers is 10-50 nanometers. To enhance molecular migration and crack repair, nano-silicon dioxide particles have a high specific surface area and surface hydroxyl groups (-OH), which can form hydrogen bonds with the polymer matrix. The filler acts as a "crack trap" during the stripping process, filling the microcracks caused by stripping and preventing the cracks from further expanding. Through the high specific surface area of ​​the filler, the migration ability of the molecular chain is enhanced, the reconstruction of the dynamic cross-linking bonds is accelerated, and the self-healing efficiency is improved.

[0074] (b) Surface glue formula, accounting for 30-40% of the total glue mass, including:

[0075] The base polymer is selected from functionalized polydimethylsiloxane (PDMS) with a molecular weight range of 50,000-100,000; providing soft and easy-to-peel properties, PDMS has a Si-O-Si main chain structure, is chemically inert and has extremely low surface energy. The low surface energy (21.6mN / m) of the PDMS molecular chain reduces the adhesion between the glue and the adherend surface, making the peeling operation easier. The highly flexible molecular chain can disperse stress during peeling and prevent damage to the adhesion interface.

[0076] Dynamic crosslinkers, accounting for 5-8% of the surface layer formula, include hydrogen bonding agents; provide recovery after peeling, hydrogen bonding agents (such as urea groups) in the surface glue can form a weak dynamic crosslinking network. The hydrogen bonds break during peeling to release the peeling stress, and after peeling, crosslinks are re-formed at room temperature to restore the integrity of the surface glue.

[0077] Anti-residue additives, accounting for 3-5% of the surface layer formula, are selected from fluorinated polymers or siloxane oligomers; anti-residue additives can migrate to the glue surface during the peeling process, reduce adhesion and prevent residue; achieve clean peeling, fluorinated polymers migrate to the surface during the peeling process, and their low surface energy and low viscosity characteristics further reduce adhesion. Anti-residue additives reduce the intermolecular forces during peeling, ensuring that there is no residue on the adherend surface after peeling.

[0078] Tackifier, accounting for 3-5% of the surface layer formulation, is selected from polyvinyl alcohol (PVA); optimizes the initial adhesion of the surface layer.

[0079] (c) Solvents or regulators, accounting for 5-10% of the total mass of the glue, including ionic liquids or other compounds that can enhance the fluidity of the material.

[0080] The viscosity of the bottom layer glue ranges from 10,000 to 15,000 mPa·s, and the viscosity of the surface layer glue ranges from 5,000 to 8,000 mPa·s to form a viscosity gradient.

[0081] A tape that can be peeled off and re-adhered multiple times using self-repairing glue, the tape comprising:

[0082] (a) The tape substrate is selected from a PET film or an OPP film, and has a microstructure on its surface, including micro-protrusions or micro-grooves; the surface micro-protrusions and micro-grooves increase the adhesion of the glue and reduce the risk of residue during peeling.

[0083] (b) A double layer of self-healing glue is sequentially coated on the substrate, wherein the thickness of the bottom layer glue is 10-20 microns and the thickness of the surface layer glue is 5-10 microns; the viscosity gradient design makes the bottom layer glue have high viscosity and a strong cross-linked network to provide adhesion performance, maintaining the long-term bonding between the tape and the adherend. The surface layer glue has low viscosity and a flexible matrix to achieve easy peeling function, and the anti-residue additive ensures the cleanliness of the peeling surface.

[0084] When peeling, the surface glue breaks first and releases stress, reducing the peeling resistance.

[0085] After peeling, the bottom layer glue rebuilds the adhesion performance through a dynamic cross-linking network and self-healing fillers, ensuring stable performance during multiple uses.

[0086] Furthermore, the double-layer glue adopts a gradient design of dynamic cross-linking agent, so that the bottom layer provides the main adhesion performance, while the surface layer is easy to peel off and reduces residue; after the self-healing glue layer is peeled off by external force, it can achieve self-repair at room temperature through reconstruction of the dynamic cross-linking agent; the tape can maintain more than 90% of the initial adhesion after ≥100 peeling and re-pasting operations.

[0087] A method for preparing a self-repairing glue comprises the following steps:

[0088] (a) Heat the base glue matrix polymer to a softened state at 60-80°C; TPU is a thermoplastic elastomer. When heated to 60-80°C, the physical crosslinking points between the molecular chains are destroyed, and the molecular chains become more flexible, forming a matrix with better fluidity. In this state, the flexible chain segments of TPU can fully combine with the subsequently added dynamic crosslinking agent, tackifier and nanofiller to form a uniformly distributed mixed system.

[0089] (b) Add the bottom layer dynamic crosslinker, nano self-healing filler and tackifier, and stir evenly to form the bottom layer glue; the furan group and maleimide group based on the Diels-Alder reaction form a preliminary crosslinking network when mixed: furan group + maleimide group → Diels-Alder crosslinking bond; this initial crosslinking network gives the bottom layer glue self-healing ability and high adhesion performance after the glue is cured. High-speed shear mixing ensures that the crosslinker is evenly dispersed in the matrix to avoid excessive or insufficient local crosslinking. Nano-silica forms multi-point interactions with the matrix polymer and dynamic crosslinker through its high specific surface area. High-speed shear stirring makes the nanoparticles evenly distributed, effectively filling the microcracks in the matrix and enhancing the repair efficiency of the dynamic crosslinking network. The polar carboxyl group of polyacrylic acid can form physical crosslinks with the matrix during stirring, improving the initial adhesion performance of the bottom layer glue.

[0090] (c) Applying a base layer of glue to the tape substrate and curing it to a thickness of 10-20 microns; (d) Heating the surface glue matrix polymer to a fluid state; During the curing process, the Diels-Alder crosslinking reaction is further enhanced to form a stable crosslinking network, ensuring that the base layer of glue has high adhesion properties. The cured nanofillers are further embedded in the network structure, which helps the glue resist crack propagation.

[0091] (e) Add surface dynamic crosslinking agent, anti-residue additive and thickener, stir evenly to form surface glue; heat to transform the PDMS molecular chain from a solid condensed structure to a liquid state with good fluidity. The functionalized PDMS molecular chain can be fully mixed with the dynamic crosslinking agent, anti-residue additive and thickener at this stage to form a uniform system. The hydrogen bonding additive (such as urea group) added to the surface glue forms a weak dynamic crosslinking network: intermolecular hydrogen bonds Dynamic fracture and reconstruction: hydrogen bonds are broken during peeling to release stress, and hydrogen bonds are re-formed at room temperature after peeling to restore adhesion. Fluoropolymers or siloxane oligomers are evenly distributed in the matrix through ultrasound-assisted dispersion technology. During the peeling process, the additive migrates to the surface interface to reduce adhesion and ensure that there is no residue on the surface of the adherend after peeling. The hydroxyl groups of polyvinyl alcohol (PVA) form physical crosslinks with the PDMS molecular chains to improve the initial adhesion of the surface glue.

[0092] (f) Apply the surface glue to the bottom surface and cure it to a thickness of 5-10 microns. During the curing process, a hydrogen bond network is gradually formed, and the anti-residue additive further enhances the peeling performance at the interface. The cured surface glue forms a low surface energy structure, further reducing the risk of residue during peeling.

[0093] Furthermore, the dynamic crosslinker of the bottom layer glue is mixed by high-speed shearing to ensure uniform dispersion and enhance the high adhesion performance of the bottom layer; high-speed shearing provides efficient mixing to ensure that the crosslinker and nanoparticles are evenly distributed in the matrix to avoid local concentration or unevenness. The anti-residue additive of the surface glue is dispersed by ultrasound-assisted technology during the stirring process to improve the anti-residue performance during peeling. The cavitation effect of ultrasound produces high-energy microbubbles, which enhance the uniform distribution of the anti-residue additive. The ultrasonically dispersed additive migrates to the interface during the peeling process to enhance the peeling performance.

[0094] Furthermore, UV-assisted curing can be selectively introduced during the curing process of the bottom layer and the surface layer to further improve the weather resistance and peeling performance of the surface layer. UV irradiation triggers the cross-linking reaction of the polymer chain, further enhancing the weather resistance of the surface glue. The dense network structure formed by UV curing significantly improves the mechanical strength and peeling performance of the surface layer.

[0095] The glue was tested within the formulation and process range with the goal of verifying the performance of the self-healing glue formula under multiple peeling and re-adhesion conditions, including peel force, self-healing efficiency, residual adhesion, and surface residue.

[0096] Test conditions

[0097] Environmental conditions: Temperature: room temperature 25°C. Humidity: 50% RH (relative humidity).

[0098] Test material: Substrate: PET film, with micro-convex surfaces (about 20 μm in diameter).

[0099] Test glue thickness: bottom glue: 10-20μm. Surface glue: 5-10μm.

[0100] Test method:

[0101] Peel force test: Test standard: ASTM D3330 (180° peel test). Peel speed: 300mm / min. Test instrument: Electronic tensile tester.

[0102] Self-repair efficiency test: Test crack interval: 50μm. Self-repair time: 24 hours (room temperature). Residual adhesion test: Simulate 50 times of peeling and re-sticking, and record the adhesion retention rate.

[0103] Surface residue observation: Use a microscope (50 times magnification) to observe whether there is any residue on the surface of the substrate. Variable parameter settings:

[0104] Bottom glue parameters:

[0105] TPU molecular weight: 80,000 / 100,000 / 120,000.

[0106] Dynamic cross-linker content: 10% / 12.5% / 15%.

[0107] Tackifier (PAA) content: 8% / 10% / 12%.

[0108] Nanofiller content: 5% / 6.5% / 8%.

[0109] Surface glue parameters:

[0110] PDMS molecular weight: 50,000 / 75,000 / 100,000.

[0111] Dynamic cross-linker content: 5% / 6% / 8%.

[0112] Anti-residue additive content: 3% / 4% / 5%.

[0113] Solvent content: 5% / 8% / 10%.

[0114] The results are summarized as follows:

[0115]

[0116]

[0117] Test results analysis

[0118] Peel force

[0119] When the TPU molecular weight is 120 kDa, the dynamic crosslinker is 15%, and the PAA tackifier is 12% (such as tests 3 and 10), the peel force is the highest, reaching 16 N / m. Lower dynamic crosslinker and PAA content (such as test 1) leads to a decrease in peel force, which is only 12 N / m.

[0120] Self-healing efficiency

[0121] High dynamic crosslinker and nanofiller content (such as experiments 3 and 10) significantly improved the self-healing efficiency to 92%-93%. Low dynamic crosslinker and nanofiller content (such as experiment 1) performed poorly, with a self-healing efficiency of only 85%.

[0122] Residual Adhesion

[0123] The combination of TPU molecular weight 120kDa and nanofiller 8% (tests 3 and 10) performed best, with residual adhesion remaining at 86%. The residual adhesion dropped to 80%-81% for lower TPU molecular weight (tests 1 and 9), indicating weaker adhesion performance of the bottom layer.

[0124] Surface residue

[0125] When the content of the surface anti-residue additive is 5% (such as test 3, 10), there is no surface residue (level 0). When the content of the anti-residue additive is less than 4% (such as test 1, 4), slight residue appears (level 1).

[0126] Best formula

[0127] Bottom glue:

[0128] TPU molecular weight: 120kDa.

[0129] Dynamic cross-linker: 12.5%-15%.

[0130] Tackifier (PAA): 10%-12%.

[0131] Nanofillers: 7%-8%.

[0132] Solvent: 10%.

[0133] Surface glue:

[0134] PDMS molecular weight: 100 kDa.

[0135] Dynamic cross-linker: 8%.

[0136] Anti-residue additive: 5%.

[0137] Tackifier (PVA): 5%.

[0138] Solvent: 10%.

[0139] The formula and test results show that this glue is suitable for scenarios that require multiple peeling and re-sticking, such as industrial assembly, home decoration, and electronic protective films.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-repairing glue for adhesive tape that can be peeled off and re-adhered multiple times, characterized in that: The glue comprises the following components: (a) The base glue formula, accounting for 60-70% of the total glue mass, includes: A base polymer selected from thermoplastic polyurethanes having a molecular weight range of 80,000-120,000; Dynamic crosslinkers, accounting for 10-15% of the base layer formulation, include compounds rich in furan groups and maleimide groups based on the Diels-Alder reaction; A tackifier, accounting for 8-12% of the base layer formulation, selected from polyacrylic acid; Nano self-healing filler, accounting for 5-8% of the base layer formula, selected from nano silicon dioxide; (b) Surface glue formula, accounting for 30-40% of the total glue mass, including: A base polymer selected from functionalized polydimethylsiloxane having a molecular weight range of 50,000-100,000; Dynamic crosslinkers, which make up 5-8% of the skin layer formulation, include hydrogen bonding aids; Anti-residue additive, accounting for 3-5% of the surface layer formulation, selected from fluoropolymers or siloxane oligomers; A tackifier, accounting for 3-5% of the surface layer formulation, is selected from polyvinyl alcohol; (c) Solvents or regulators, accounting for 5-10% of the total mass of the glue, including ionic liquids or other compounds that can enhance the fluidity of the material.

2. The self-repairing glue for tape that can be peeled off and re-adhered multiple times according to claim 1, characterized in that: The viscosity of the bottom layer glue is in the range of 10,000-15,000 mPa·s, and the viscosity of the surface layer glue is in the range of 5,000-8,000 mPa·s, so as to form a viscosity gradient.

3. The self-repairing glue for tape that can be peeled off and re-adhered multiple times according to claim 1, characterized in that: The molar ratio of the furan group to the maleimide group of the dynamic crosslinking agent is 1:

1.

4. The self-repairing glue for tape that can be peeled off and re-adhered multiple times according to claim 1, characterized in that: The anti-residue auxiliary agent can migrate to the glue surface during the peeling process, reduce adhesion and prevent residue.

5. The self-repairing glue for tape that can be peeled off and re-adhered multiple times according to claim 1, characterized in that: The particle size of the nano self-repairing filler is 10-50 nanometers.

6. An adhesive tape that can be peeled off and re-adhered multiple times prepared using the self-repairing adhesive according to any one of claims 1 to 5, characterized in that: The adhesive tape comprises: (a) a tape substrate, selected from a PET film or an OPP film, having a surface having a microstructure, including micro protrusions or micro grooves; (b) A double layer of self-healing glue is sequentially coated on the substrate, wherein the thickness of the bottom layer of glue is 10-20 μm and the thickness of the surface layer of glue is 5-10 μm.

7. The multiple peeling and re-sticking tape according to claim 6, characterized in that: The double-layer glue adopts a gradient design of a dynamic cross-linking agent so that the bottom layer provides the main adhesion performance, while the surface layer is easy to peel off and reduces residue; after the self-healing glue layer is peeled off by external force, it can achieve self-healing at room temperature through reconstruction of the dynamic cross-linking agent; the tape can maintain more than 90% of the initial adhesion after ≥100 peeling and re-pasting operations.

8. A method for preparing the self-repairing glue according to any one of claims 1 to 5, comprising the following steps: (a) heating the base glue matrix polymer to a softened state at 60-80° C.; (b) adding a bottom layer dynamic crosslinking agent, a nano self-healing filler and a tackifier, and stirring evenly to form a bottom layer glue; (c) coating a base layer of glue on the tape substrate and curing the base layer to a thickness of 10-20 μm; (d) heating the surface glue matrix polymer to a fluid state; (e) adding a surface dynamic crosslinking agent, an anti-residue additive and a tackifier, and stirring evenly to form a surface glue; (f) Apply the top layer of glue to the bottom surface and cure it to a thickness of 5-10 microns.

9. The method for preparing self-repairing glue according to claim 8, characterized in that: The dynamic cross-linking agent of the bottom layer glue is mixed by high-speed shearing to ensure uniform dispersion and enhance the high adhesion performance of the bottom layer; the anti-residue additive of the surface layer glue is dispersed by ultrasound-assisted technology during the stirring process to improve the anti-residue performance during peeling.

10. The method for preparing self-repairing glue according to claim 8, characterized in that: During the curing process of the bottom layer and the surface layer, ultraviolet rays can be selectively introduced to assist in curing, so as to further improve the weather resistance and peeling performance of the surface layer.

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