Thermal-response reversible-adhesion acrylic pressure-sensitive adhesive tape and preparation method thereof

Abstract

The invention discloses a thermal-response reversible-adhesion acrylic pressure-sensitive adhesive tape and a preparation method thereof. The thermal-response reversible-adhesion acrylic pressure-sensitive adhesive tape comprises a polymer base material and an adhesive layer, the adhesive layer is formed by coating temperature response viscosity reversible glue on the polymer base material, curing and cross-linking; the adhesive comprises the following components: an acrylic acid hard monomer, an acrylic acid soft monomer, a temperature-sensitive functional monomer, an acrylic acid monomer with a cross-linking group, an initiator, a chain transfer agent, hydrogenated rosin resin and an aziridine cross-linking agent. According to the invention, the polymer substrate after plasma activation is coated with the temperature response viscosity reversible adhesive layer, and the working principle is that when the ambient temperature reaches the working temperature of the adhesive layer or above, the conformation of the thermo-sensitive monomer molecules in the adhesive layer is overturned, and meanwhile, the whole adhesive layer shrinks and hardens, so that the surface of the polymer substrate cannot be infiltrated; the adhesive layer and the surface interface of the polymer base material are invalid, so that the adhesive tape can be repeatedly used and resources are saved.

Description

Technical Field

[0001] This invention relates to the field of pressure-sensitive tapes, specifically to a thermally responsive reversible adhesive acrylic pressure-sensitive tape and its preparation method. Background Technology

[0002] Acrylic pressure-sensitive adhesives are widely used in electronic component mounting, display bonding, automotive interiors, energy-saving building glass, medical adhesive materials, and everyday labels due to their advantages such as high initial tack, good holding power, excellent weather resistance, high transparency, and strong formula designability. Acrylic pressure-sensitive adhesive tapes typically consist of a pressure-sensitive adhesive base, a substrate, and a release material. After coating, drying, and curing, they form an adhesive layer with a certain thickness and viscosity gradient, achieving long-term or short-to-medium-term adhesion to the surfaces of the adhered objects.

[0003] Traditional acrylic pressure-sensitive adhesive systems are typically "constant tack" or weakly temperature-dependent, meaning their tack changes little within their designed operating temperature range, with significant performance degradation only occurring at extremely high or low temperatures. While these tapes are suitable for long-term fixation, they have significant limitations in scenarios requiring "controlled assembly / disassembly," "reusability," or "on-demand disassembly." For example, during the assembly and repair of precision electronic components or optical assemblies, it is desirable for the tape to maintain sufficient adhesion at room temperature to ensure reliable fixation, while significantly reducing tack under specific temperature conditions to achieve non-destructive disassembly and reuse. Traditional systems struggle to achieve this "tack on / off" or "reversible tack control" through simple temperature adjustments.

[0004] To achieve controllable adjustment of viscosity with temperature, existing technologies have proposed introducing thermoplastic elastomers, crystallizable polymers, or thermally responsive polymers (such as polymers with a low critical solution temperature (LCST) structure) into pressure-sensitive adhesives. These attempts aim to regulate the flowability and interfacial wettability of the adhesive layer by altering changes in glass transition temperature, crystallization melting behavior, or phase separation structure. However, these systems often suffer from the following problems: First, the temperature response window is narrow and cannot be finely controlled, making them susceptible to fluctuations in ambient temperature during practical applications, leading to unstable viscosity. Second, some systems undergo irreversible structural rearrangement or phase separation after a single heating or cooling cycle, resulting in viscosity decay and making it difficult to achieve reversible viscosity over multiple cycles. Third, to obtain a significant temperature response effect, a high proportion of special monomers or functional additives is often required, resulting in complex formulations and high costs, which hinders industrialization.

[0005] On the other hand, some existing temperature-sensitive pressure-sensitive adhesives or tapes also have shortcomings in balancing adhesive properties. For example, in order to ensure high initial tack and holding power at low temperatures, the system often exhibits severe creep, edge flow, or even loss of tack at high temperatures; while in order to improve high-temperature stability, it is easy to lead to insufficient initial tack at low or room temperature, making it difficult to meet the dual requirements of "reliable adhesion at room temperature" and "easy peeling at specific temperatures". In addition, some temperature-responsive adhesive systems require complex multi-step polymerization or microencapsulation processes, which are difficult to control during production, have poor environmental friendliness, and are not conducive to direct introduction into existing coating production lines.

[0006] With the rapid development of emerging application fields such as wearable devices, flexible displays, detachable building decorations, and smart packaging, the market has placed higher demands on acrylic pressure-sensitive tapes with "temperature-responsive reversible adhesion." On the one hand, it requires maintaining high and stable adhesion and durability within a set low or normal temperature range; on the other hand, it is desirable for the adhesive layer adhesion to significantly decrease at a higher or lower trigger temperature, achieving controllable peeling, and for the adhesion to be largely restored after temperature recovery, to meet the needs of multiple adhesive-peel cycles. Currently, there is a lack of acrylic pressure-sensitive tapes with a relatively simple structure and formulation, a process compatible with existing coating equipment, and the ability to maintain reversibly adjustable adhesion performance across multiple temperature cycles, as well as a method for their preparation. Therefore, it is necessary to provide an acrylic pressure-sensitive tape with temperature-responsive reversible adhesion characteristics and its preparation method to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape and its preparation method, thereby solving the problems mentioned in the background art. The acrylic pressure-sensitive tape with temperature-responsive, reversibly adhesive properties proposed in this invention exhibits good adhesion at room temperature, and its adhesion increases with temperature reaching 55-60°C. o The viscosity of C is lost and can be easily removed. When the temperature drops to room temperature, the viscosity can be restored and the device can be reused.

[0008] The present invention provides a thermally responsive reversible adhesive acrylic pressure-sensitive tape, comprising a substrate and an adhesive layer, wherein the adhesive layer is formed by coating the substrate with adhesive and curing it.

[0009] The adhesive comprises the following components: hard acrylic monomer, soft acrylic monomer, thermosensitive functional monomer, acrylic monomer with crosslinking points, initiator, chain transfer agent, hydrogenated rosin resin, and aziridine in the ratio of (2-6): (23-45): (3-8): (1-4): (0.3-0.8): (0.9-1.6): (2-8): (0.5-1.2).

[0010] Furthermore, the acrylic acid hard monomer is one or more of dimethylaminoethyl methacrylate, acetoxyethyl methacrylate, methoxyethyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and N-hydroxymethylacrylamide; the acrylic acid soft monomer is one or more of ethyl acrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, n-octyl acrylate, and lauryl acrylate.

[0011] Furthermore, the temperature-sensitive functional monomer is one or more of N-isopropylacrylamide, N-isopropylmethacrylamide, N,N-diethylacrylamide, 2-(dimethylamino)ethyl methacrylate, methyl polyethylene glycol ether methacrylate, and oligoethylene glycol methacrylate.

[0012] Furthermore, the initiator is one or a mixture of several of the following: benzoyl peroxide, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl peroxyvalerate, diisopropyl peroxydicarbonate, azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azoisobutylcyanoformamide, and cumene hydroperoxide.

[0013] Furthermore, the acrylic monomer with crosslinkable groups is one or a mixture of several of the following: acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, 3-carboxypropyl acrylate, and 3-carboxypropyl methacrylate.

[0014] Furthermore, the crosslinking agent is aziridine.

[0015] Furthermore, the substrate is any one of PET film, BOPP film, PP film, PI film, PE film or PVC film.

[0016] This invention also proposes a method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape, comprising the following steps: S1. Divide the hard monomer, soft monomer, thermosensitive functional monomer, acrylic monomer with crosslinkable sites, chain transfer agent and initiator into two portions. Add the first portion of hard monomer, the first portion of soft monomer, the first portion of thermosensitive monomer, the first portion of acrylic monomer with crosslinkable sites, the first portion of initiator and the first portion of chain transfer agent to the reactor, stir and heat to 70-90℃, and stir at a speed of 600-900 rpm. S2. By weight, continue to add the second part of hard monomer, the second part of soft monomer, the second part of temperature-sensitive monomer, the second part of acrylic monomer with crosslinkable sites, the second part of initiator and the second part of chain transfer agent dropwise into the reactor. The dropwise addition takes 60 minutes. After the dropwise addition is completed, continue to keep the reaction at the temperature for 400 minutes. Then add hydrogenated rosin resin and continue to mix and stir for 30 minutes to obtain the raw rubber. S3. Add aziridine to the original adhesive, set the mixer speed to 200-400 rpm, and continue mixing for 30 minutes to obtain the adhesive. S4. The substrate is treated with a 50W plasma corona generator for 30s, and an adhesive is coated on the activated substrate surface using a scraper. The adhesive is then cured at high temperature to prepare an acrylic pressure-sensitive tape with temperature-responsive and reversible adhesive properties.

[0017] Furthermore, by weight, the ratio of the first part of hard monomer to the second part of hard monomer is (3-7):(2-4); the ratio of the first part of soft monomer to the second part of soft monomer is (20-40):(20-30); the ratio of the first part of thermosensitive functional monomer to the second part of thermosensitive functional monomer is (2-6):(1-3); the ratio of the first part of acrylic monomer with crosslinkable points to the second part of acrylic monomer with crosslinkable points is (0.5-1.2):(0.6-1.4); and the ratio of the first part of initiator to the second part of initiator is (0.2-0.6):(0.1-0.3).

[0018] Furthermore, in S4, a scraper is used for coating, the oven temperature rises in a stepped manner from the outside to the inside, and gradually decreases in a stepped manner after reaching the highest temperature of 80°C. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention adds hydrogenated rosin tackifying resin to acrylic acid. The tackifying resin with a high softening point can improve the adhesiveness at room temperature and high temperature cohesion. Secondly, the liquid resin can not only improve the initial tack of the tape, but also reduce the hardness of the tape, preventing local stress concentration during use due to low winter temperature, which can lead to delamination at certain points.

[0020] This invention also uses aziridine as a crosslinking agent to improve the cohesive strength of the pressure-sensitive adhesive tape. At high temperature, the three-membered ring-shaped aziridine undergoes a ring-opening reaction with the carboxylic acid. After the trifunctional aziridine undergoes a crosslinking reaction with the carboxyl group in the polyacrylate, the cohesiveness of the adhesive layer is improved.

[0021] Furthermore, the addition of aziridine to the masterbatch results in good adhesive properties at room temperature. When the temperature rises to 55-60℃, the masterbatch loses its adhesiveness but can be easily removed. Upon returning to room temperature, the adhesiveness is restored, allowing for reuse. At high temperatures, the increased molecular motion of temperature-sensitive functional monomers causes molecular chain segment rotation, weakening the hydrogen bond strength between the adhesive and the substrate while strengthening the intermolecular hydrogen bond strength. Simultaneously, the entire adhesive layer shrinks and hardens, failing to wet the substrate surface, leading to adhesive deactivation. Upon returning to room temperature, the rotated molecular chain segments return to their original state, the intermolecular hydrogen bond strength weakens, and the adhesive layer's adhesion is restored. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a graph showing the change in adhesive strength of acrylic pressure-sensitive tape at different temperatures in Example 1.

[0023] Figure 2 This is a graph showing the change in adhesive strength of acrylic pressure-sensitive tape at different temperatures in Example 4.

[0024] Figure 3 This is a graph showing the change in adhesive strength of acrylic pressure-sensitive tape at different temperatures in Comparative Example 1.

[0025] Figure 4 This is a graph showing the change in adhesive strength of acrylic pressure-sensitive tape at different temperatures, which is the curve of Comparative Example 4. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0028] A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 2g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 2g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep warm for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡. Example

[0029] A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 3g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 3g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep the temperature for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡. Example

[0030] A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 4g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 2g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep warm for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡. Example

[0031] A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 4g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 3g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep the temperature for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4. The PP substrate is treated with a 50W plasma corona treatment for 30 seconds. Adhesive is then applied to the activated PP substrate surface using a scraper. The oven temperature increases in a stepped manner from the outside to the inside, reaching a maximum temperature of 80°C. o C decreases gradually in a step-like manner, the machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0032] Comparative Example 1 A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep the temperature for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive; S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0033] Comparative Example 2 A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 2g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 2g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep warm for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 0.2wt% toluene diisocyanate to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0034] Comparative Example 3 A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 2g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 2g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep warm for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 1.0wt% aziridine to the original adhesive, set the mixer speed to 350rpm, and continue stirring for 15min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0035] Comparative Example 4 A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape includes the following steps: S1. Add 10g hydroxyethyl methacrylate, 125g butyl acrylate, 2g N-isopropylacrylamide, 5g acrylic acid, 1.5g azobisisobutyronitrile, and 5g 2-cyano-2-propyl dithiobenzoate to the reaction vessel, stir and heat to 80℃, and stir at a speed of 700rpm. S2. Continue to add 6g of hydroxyethyl methacrylate, 125g of butyl acrylate, 2g of N-isopropylacrylamide, 6g of acrylic acid, and 1.0g of azobisisobutyronitrile to the reactor dropwise over 90 minutes. After the addition is complete, continue to keep warm for 400 minutes. Then add hydrogenated rosin resin and continue stirring for 40 minutes to obtain the raw gel. S3. Add 2.0 wt% aziridine to the original adhesive, set the mixer speed to 350 rpm, and continue stirring for 15 min to obtain the acrylic pressure-sensitive adhesive with temperature-responsive reversible viscosity. S4.PP substrate is treated with a 50W plasma corona machine for 30s. Adhesive is then applied to the surface of the activated PP substrate using a scraper. The oven temperature rises in a stepwise manner from the outside to the inside, reaching a maximum temperature of 80℃ and then gradually decreasing in a stepwise manner. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

[0036] This invention prepares high-molecular-weight acrylic pressure-sensitive tape with temperature-responsive reversible adhesion through a reversible addition-fragmentation chain transfer reaction. Examples demonstrate the effect of the content of temperature-sensitive functional monomers in the system on the adhesion performance of the acrylic pressure-sensitive tape at room temperature and high temperature. Comparative examples also verify the importance of the type and content of crosslinking agents. The overall process and formulation result in a product that exhibits both high adhesion at room temperature and low adhesion and low residue at high temperatures.

[0037] The above description is merely a preferred embodiment of the thermally responsive reversible adhesive acrylic pressure-sensitive tape and its preparation method according to the present invention. It should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A thermally responsive, reversibly adhesive acrylic pressure-sensitive tape, characterized in that: The tape includes a polymer substrate and a temperature-responsive, reversible adhesive layer, which is formed by coating the polymer substrate with a temperature-responsive, reversible adhesive and curing it.

2. The thermally responsive reversibly adhesive acrylic pressure-sensitive tape as described in claim 1, characterized in that: The substrate is any one of PET film, BOPP film, PP film, PE film or PVC film.

3. The thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 1, characterized in that: The temperature-responsive reversible adhesive comprises the following components: hard acrylic monomer, soft acrylic monomer, thermosensitive functional monomer, acrylic monomer with crosslinking group, initiator, chain transfer agent, hydrogenated rosin resin, and aziridine crosslinking agent; by weight, the ratio of hard acrylic monomer, soft acrylic monomer, thermosensitive functional monomer, acrylic acid, initiator, chain transfer agent, hydrogenated rosin resin, and aziridine crosslinking agent is (2-6):(23-45):(3-8):(1-4):(0.3-0.8):(0.9-1.6):(2-8):(0.5-1.2).

4. A thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 3, characterized in that: The crosslinking agent is aziridine, and the hard acrylic monomer is one or more of dimethylaminoethyl methacrylate, acetoxyethyl methacrylate, methoxyethyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and N-hydroxymethylacrylamide; the soft acrylic monomer is one or more of ethyl acrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, n-octyl acrylate, and lauryl acrylate.

5. The thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 3, characterized in that: The thermosensitive functional monomer is one or more of N-isopropylacrylamide, N-isopropylmethacrylamide, N,N-diethylacrylamide, 2-(dimethylamino)ethyl methacrylate, methyl polyethylene glycol ether methacrylate, and oligoethylene glycol methacrylate.

6. The thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 3, characterized in that: The initiator is one or a mixture of several of the following: benzoyl peroxide, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl peroxyvalerate, diisopropyl peroxydicarbonate, azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azoisobutylcyanoformamide, and cumene hydroperoxide. The acrylic monomer with crosslinkable groups is one or a mixture of several of the following: acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, 3-carboxypropyl acrylate, and 3-carboxypropyl methacrylate.

7. The thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 3, characterized in that: The chain transfer agent is one or a mixture of several of the following: 2-cyano-2-propyl dithiobenzoate, α,α-dimethylbenzyl dithiobenzoate, 4-cyano-4-[(thiobenzoyl)thio]valerate, S-dodecyl-S′-(α,α′-dimethyl-α″-acetic acid)trithiocarbonate, 2-(dodecyl trithiocarbonate sulfonyl)-2-methylpropionic acid, N,N-dimethyl dithiocarbamate, O-ethyl S-(1-methoxycarbonyl)ethyl xanthate, and S-dodecyl O-ethyl xanthate.

8. A method for preparing a thermally responsive, reversibly adhesive acrylic pressure-sensitive tape, characterized in that: The preparation of the acrylic pressure-sensitive tape with temperature-responsive reversible viscosity includes the following steps: S1. Divide the hard monomer, soft monomer, thermosensitive functional monomer, acrylic monomer with crosslinkable sites, chain transfer agent and initiator into two portions. Add the first portion of hard monomer, the first portion of soft monomer, the first portion of thermosensitive monomer, the first portion of acrylic monomer with crosslinkable sites, the first portion of initiator and the first portion of chain transfer agent to the reactor, stir and heat to 70-90℃, and stir at a speed of 600-900 rpm. S2. By weight, continue to add the second part of hard monomer, the second part of soft monomer, the second part of temperature-sensitive monomer, the second part of acrylic monomer with crosslinkable sites, the second part of initiator and the second part of chain transfer agent dropwise into the reactor. The dropwise addition takes 60 minutes. After the dropwise addition is completed, continue to keep the reaction at the temperature for 400 minutes. Then add hydrogenated rosin resin and continue to mix and stir for 30 minutes to obtain the raw rubber. S3. Add aziridine to the original adhesive, set the mixer speed to 200-400 rpm, and continue mixing for 30 minutes to obtain the adhesive. S4. The substrate is treated with a 50W plasma corona generator for 30s, and an adhesive is coated on the activated substrate surface using a scraper. The adhesive is then cured at high temperature to prepare an acrylic pressure-sensitive tape with temperature-responsive and reversible adhesive properties.

9. The method for preparing a thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 8, characterized in that: By weight, the ratio of the first part of hard monomer to the second part of hard monomer is (3-7):(2-4); the ratio of the first part of soft monomer to the second part of soft monomer is (20-40):(20-30); the ratio of the first part of thermosensitive functional monomer to the second part of thermosensitive functional monomer is (2-6):(1-3); the ratio of the first part of acrylic monomer with crosslinkable points to the second part of acrylic monomer with crosslinkable points is (0.5-1.2):(0.6-1.4); and the ratio of the first part of initiator to the second part of initiator is (0.2-0.6):(0.1-0.3).

10. The method for preparing a thermally responsive reversibly adhesive acrylic pressure-sensitive tape according to claim 9, characterized in that: In S4, a thermosetting coating machine is used for coating. The oven temperature rises in a stepwise manner from the outside to the inside, and then gradually decreases in a stepwise manner after reaching the highest temperature of 80°C. The machine speed is 14m / min, and the coating dry weight is 40g / ㎡.

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