An acrylate system hot melt pressure sensitive adhesive and a method of making the same

Abstract

This invention relates to the field of adhesive technology, and more particularly to an acrylic ester-based hot melt pressure-sensitive adhesive and its preparation method. Calculated by mass parts, it comprises the following raw materials: 15-30 parts rubber oil, 20-30 parts acrylic rubber, 40-60 parts rosin resin, 0.5-3 parts polyvinylpyrrolidone, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber. The acrylic ester-based hot melt pressure-sensitive adhesive and its preparation method proposed in this invention overcome the limitations of SBC-based hot melt pressure-sensitive adhesives by improving weather resistance and providing a washable detachment response mechanism. It not only achieves durable adhesion but also enables automatic detachment without residue under washing conditions, thus overcoming the shortcomings of existing technologies.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and in particular to an acrylate-based hot melt pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Hot melt pressure-sensitive adhesives have become the preferred adhesive for high-speed coating production of traditional paper and film labels due to their advantages such as high coating efficiency, solvent-free nature, and fast curing.

[0003] Washable labels typically consist of a face stock and a hot-melt pressure-sensitive adhesive layer. They are primarily used in containers, packaging, and textiles that require repeated washing or recycling. Under specific washing conditions (e.g., immersion in an alkaline solution at 80–90°C and pH 9–11 for approximately 200 seconds), the label must detach completely from the surface of the object without leaving any hot-melt pressure-sensitive adhesive residue, thus enabling the recycling of the object. It's important to note that the layer in direct contact with the object in a washable label is the hot-melt pressure-sensitive adhesive layer. If this layer loses its adhesiveness and detaches under washing conditions, even if the bond between the face stock and the adhesive layer weakens with prolonged use or washing, the face stock can detach along with the adhesive layer, or be naturally washed away by the washing water, as long as the adhesive layer can break down completely at the interface with the object. Therefore, whether a washable label can be completely removed from the surface of the object depends mainly on whether the hot melt pressure-sensitive adhesive layer can detach from the object without leaving any residue.

[0004] Currently, the most commonly used hot-melt pressure-sensitive adhesives in the labeling industry are styrene block copolymer (SBC) systems, prepared by hot-melt blending SBC elastomers with tackifying resins and softening oils. This SBC system hot-melt pressure-sensitive adhesive exhibits good coating adaptability and initial tack, meeting the needs of general labels. However, applying SBC system hot-melt pressure-sensitive adhesives to washable labels faces the following technical challenges: (1) Insufficient aging resistance, failing to meet adhesion durability requirements. Specifically, the SBC system hot melt pressure-sensitive adhesive, due to the presence of highly reactive carbon-carbon double bonds in its molecular chain, is prone to oxidative degradation and cross-linking reactions under light, high temperature, or humid conditions, leading to easy aging of the hot melt pressure-sensitive adhesive layer in washable labels. The cohesive strength of the aged hot melt pressure-sensitive adhesive layer decreases, resulting in reduced adhesion durability during storage and use.

[0005] (2) Lack of a water-washable detachment response mechanism and easy residue. Even if the SBC system hot melt pressure-sensitive adhesive is not aged after labeling, its inherent hydrophobic and non-polar chemical properties make it difficult to respond to water washing conditions. In alkaline solutions, water molecules have difficulty effectively penetrating and acting on the interface between the hot melt pressure-sensitive adhesive and the substrate, thus failing to trigger a significant decrease in adhesion and failing to detach automatically during water washing. More importantly, even if forced detachment occurs, both aged and non-aged SBC system hot melt pressure-sensitive adhesives tend to undergo cohesive failure (the adhesive layer itself breaks), resulting in some residue stubbornly remaining on the substrate surface, causing residue.

[0006] In summary, existing SBC system hot melt pressure-sensitive adhesives generally suffer from technical problems such as insufficient adhesion durability, inability to be automatically washed off, and easy generation of adhesive residue, which fail to meet the application requirements. Summary of the Invention

[0007] The purpose of this invention is to propose an acrylic ester system hot melt pressure-sensitive adhesive and its preparation method. By improving weather resistance and providing a water-washable detachment response mechanism, it overcomes the limitations of SBC system hot melt pressure-sensitive adhesives. It can not only achieve durable adhesion, but also automatically detach without residue under water washing conditions, thus overcoming the shortcomings of the prior art.

[0008] To achieve this objective, the present invention adopts the following technical solution: An acrylic ester-based hot melt pressure-sensitive adhesive, by weight, comprises the following raw materials: 15-30 parts rubber oil, 20-30 parts acrylic ester rubber, 0.5-3 parts polyvinylpyrrolidone, 40-60 parts rosin resin, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber.

[0009] Furthermore, the glass transition temperature of the acrylate rubber is -40 to -25°C.

[0010] Furthermore, the hydroxyl content in the acrylate rubber is 0.5% to 1% by mass percentage.

[0011] Furthermore, the rubber oil is a naphthenic oil.

[0012] Furthermore, the rosin resin includes either rosin glycerol ester or rosin pentaerythritol ester.

[0013] Furthermore, the antioxidant includes a primary antioxidant and a secondary antioxidant, wherein the primary antioxidant includes either antioxidant 1098 or antioxidant 1010, and the secondary antioxidant includes antioxidant 168.

[0014] Furthermore, the ultraviolet absorber includes any one of benzotriazole ultraviolet absorbers and triazine ultraviolet absorbers.

[0015] A method for preparing an acrylic ester-based hot melt pressure-sensitive adhesive, comprising the following steps: A. Add the formulated amount of rubber oil, antioxidant, polyvinylpyrrolidone, ultraviolet absorber and 40% of the formulated amount of rosin resin to the reactor, and stir at a temperature of 140-150℃ until completely melted to obtain the first mixture; B. Add the formulated amount of acrylate rubber to the first mixture and stir at a temperature of 140-150°C until completely melted to obtain the second mixture; C. Add the remaining amount of rosin resin to the second mixture and stir at 140-150°C until completely melted to obtain an acrylic ester system hot melt pressure-sensitive adhesive.

[0016] The technical solution provided by this invention may include the following beneficial effects: 1. This technical solution uses a triple synergistic mechanism of eliminating weaknesses through saturated structure, blocking reaction with antioxidants, and shielding light energy with ultraviolet absorbers to form a defense system. This effectively solves the problem of insufficient aging resistance of traditional SBC system hot melt pressure sensitive adhesives and meets the requirements for adhesion durability during storage and use.

[0017] 2. Both acrylic rubber and rosin resin contain a large number of ester groups. When immersed in an alkaline solution at 80-90℃ and pH 9-11, the ester groups in the acrylic rubber and rosin resin undergo saponification to generate carboxylate and alcohol. This saponification reaction enables the hot melt pressure-sensitive adhesive to detach automatically without residue. The specific mechanism is as follows: First, the highly water-soluble polyvinylpyrrolidone facilitates water molecules to penetrate into the interface between the hot melt pressure-sensitive adhesive layer and the substrate. The acrylic rubber and rosin resin in the formulation... The strong hydrophilic carboxylate groups generated by the reaction of grease in an alkaline solution at 80–90℃ and pH 9–11 dramatically increase the polarity and hydrophilicity of the hot-melt pressure-sensitive adhesive layer. This drives the alkaline solution to rapidly and deeply penetrate and wet the entire bonding interface, establishing a washable detachment response mechanism and significantly reducing the adhesion between the hot-melt pressure-sensitive adhesive and the adhered object. Secondly, the water molecules and ions enriched at the interface significantly weaken the physical adsorption and electrostatic interaction between the hot-melt pressure-sensitive adhesive and the adhered object (such as glass), leading to a reversible loss of interfacial adhesion. The synergistic effect of these two factors effectively controls the detachment path, achieving automatic detachment without residue. Detailed Implementation

[0018] This technical solution provides an acrylate-based hot melt pressure-sensitive adhesive, which, by weight, includes the following raw materials: 15-30 parts rubber oil, 20-30 parts acrylate rubber, 40-60 parts rosin resin, 0.5-3 parts polyvinylpyrrolidone, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber.

[0019] To address the common technical problems of insufficient adhesion durability, inability to automatically detach from water, and easy residue formation in existing SBC-based hot melt pressure-sensitive adhesives, this technical solution proposes an acrylic ester-based hot melt pressure-sensitive adhesive. By designing and optimizing the formulation of the hot melt pressure-sensitive adhesive to improve its weather resistance and provide a water-washable detachment response mechanism, this solution overcomes the limitations of SBC-based hot melt pressure-sensitive adhesives. It not only achieves adhesion durability but also enables automatic detachment without residue under water washing conditions, thus meeting practical application requirements.

[0020] Specifically, the raw materials for the acrylate-based hot-melt pressure-sensitive adhesive in this technical solution include rubber oil, acrylate rubber, rosin resin, polyvinylpyrrolidone, antioxidants, and ultraviolet absorbers. Unlike traditional styrene block copolymers (SBCs), acrylate rubber refers to synthetic rubber copolymerized from various acrylate monomers. Its main chain has a saturated carbon-carbon single bond structure and lacks highly chemically reactive carbon-carbon double bonds. These structural characteristics fundamentally eliminate the possibility of oxidative degradation and cross-linking reactions under light, high temperature, or humid conditions, thereby improving the aging resistance of the acrylate-based hot-melt pressure-sensitive adhesive.

[0021] Furthermore, the antioxidants in the formulation can efficiently capture free radicals generated by the polymer during the initial processing or use, and decompose the generated hydroperoxides, thereby actively blocking the autocatalytic chain reaction of thermo-oxidative aging, preventing further breakage or cross-linking of molecular chains, ensuring that the hot melt pressure-sensitive adhesive maintains its mechanical properties during high-temperature processing, long-term storage and use, and improving its aging resistance.

[0022] Furthermore, the UV absorber in the formulation preferentially absorbs high-energy UV radiation and converts it into harmless, low-heat release. This mechanism effectively prevents UV radiation from directly causing the breakage of polymer (such as acrylate rubber) molecular chains or generating new free radicals, thus further improving aging resistance.

[0023] In summary, this technical solution constitutes a defense system through a triple synergistic mechanism of eliminating weaknesses through saturated structure, blocking reactions with antioxidants, and shielding light energy with ultraviolet absorbers. This effectively solves the problem of insufficient aging resistance of traditional SBC system hot melt pressure-sensitive adhesives and meets the requirements for adhesive durability during storage and use.

[0024] Secondly, both acrylic rubber and rosin resin contain a large number of ester groups. When immersed in an alkaline solution at a temperature of 80-90℃ and a pH of 9-11, the ester groups in the acrylic rubber and rosin resin undergo a saponification reaction, generating carboxylates and alcohols. This saponification reaction enables the hot melt pressure-sensitive adhesive to detach automatically without residue. The specific mechanism is as follows: First, the highly water-soluble polyvinylpyrrolidone facilitates the entry of water molecules into the interface between the hot melt pressure-sensitive adhesive layer and the substrate through wetting. The acrylic rubber and rosin resin in the formulation... The strong hydrophilic carboxylate groups generated by the reaction of grease in an alkaline solution at 80–90℃ and pH 9–11 dramatically increase the polarity and hydrophilicity of the hot-melt pressure-sensitive adhesive layer. This drives the alkaline solution to rapidly and deeply penetrate and wet the entire bonding interface, establishing a washable detachment response mechanism and significantly reducing the adhesion between the hot-melt pressure-sensitive adhesive and the adhered object. Secondly, the water molecules and ions enriched at the interface significantly weaken the physical adsorption and electrostatic interaction between the hot-melt pressure-sensitive adhesive and the adhered object (such as glass), leading to a reversible loss of interfacial adhesion. The synergistic effect of these two factors effectively controls the detachment path, achieving automatic detachment without residue.

[0025] In addition, as described above, the hot melt pressure-sensitive adhesive of this technical solution has high aging resistance, which also helps to avoid the decrease in cohesive strength of the hot melt pressure-sensitive adhesive layer after aging, and the cohesive failure during the automatic detachment process of water washing, resulting in residual adhesive. This also helps to achieve automatic detachment without residue.

[0026] It should be noted that, under dry conditions, the acrylic rubber, rosin resin, and rubber oil in this technical solution work together to form a viscoelastically balanced adhesive layer. The acrylic rubber provides the main structure, the rosin resin provides initial tack by rapidly wetting the interface and enhancing intermolecular forces, while the rubber oil, as a plasticizer, adjusts the modulus of the adhesive layer and improves its penetration and wetting ability on the surface of the object to be bonded. The above components work synergistically to give the hot melt pressure-sensitive adhesive a strong and durable physical adhesion at room temperature, ensuring stable adhesion to the surface of the object to be bonded during storage, transportation, and use.

[0027] Furthermore, the water-washable detachment response mechanism of this technical solution is triggered on demand. Specifically, under normal temperature and non-alkaline conditions, the ester groups are relatively stable, and the hot-melt pressure-sensitive adhesive maintains excellent aging resistance. The saponification reaction is only triggered under specific water washing conditions, thus facilitating the unification of adhesive durability and water-washable detachment without residue.

[0028] To further clarify, the glass transition temperature of the acrylate rubber is -40 to -25°C.

[0029] This technical solution limits the glass transition temperature of acrylic rubber, ensuring that the acrylic rubber is in a highly elastic state at room temperature. Its molecular chains possess moderate mobility, providing not only good initial tack and wettability to the surface of the substrate, but also sufficient cohesive strength to guarantee durable adhesion. Furthermore, when placed in a water-washing environment at 80–90°C, the operating temperature is much higher than the glass transition temperature of the acrylic rubber. This fully activates the molecular chains, resulting in extremely strong mobility and vigorous movement, significantly increasing the free volume. This greatly promotes the penetration and diffusion of alkaline solutions and facilitates efficient saponification with the ester groups, thereby synergistically triggering the rapid loss of interfacial adhesion and ultimately achieving residue-free detachment.

[0030] To further clarify, the hydroxyl content in the acrylate rubber is 0.5% to 1% by mass percentage.

[0031] This technical solution limits the hydroxyl content in the acrylate rubber to 0.5-1%, which is beneficial for utilizing the hydroxyl group to provide appropriate polarity and also facilitates the interfacial response of the hot melt pressure-sensitive adhesive under water washing conditions, thereby achieving residue-free detachment. It should be noted that since acrylate rubber is polymerized from various acrylate monomers, at least one of them can be limited to a functional monomer containing an active hydroxyl group (such as hydroxyethyl acrylate), thus limiting the mass percentage of hydroxyl groups in the acrylate rubber to between 0.5-1%.

[0032] To further clarify, the rubber oil is a naphthenic oil.

[0033] This technical solution limits the rubber oil to naphthenic oil, taking advantage of the fact that naphthenic oil has higher polarity and better compatibility than paraffin oil (a type of rubber oil). This increases the free volume between its chain segments, making it easier for water molecules to diffuse into the interior of the acrylic rubber layer and the bonding interface under high temperature washing. This is more conducive to establishing a water-washable detachment response mechanism and reducing the adhesion between the hot melt pressure-sensitive adhesive and the adhered object, further facilitating automatic detachment without residue.

[0034] To further clarify, the rosin resin includes either rosin glycerol ester or rosin pentaerythritol ester.

[0035] The rosin resin used in this solution is one of rosin glycerol ester and rosin pentaerythritol ester. The ester groups rich in the above-mentioned rosin resin cooperate with the ester groups in the acrylic rubber to undergo a controllable saponification reaction under alkaline water washing conditions and construct a water-washable response mechanism to achieve automatic separation without residue.

[0036] To further explain, the antioxidant includes a primary antioxidant and a secondary antioxidant, and the primary antioxidant includes either antioxidant 1098 or antioxidant 1010, while the secondary antioxidant includes antioxidant 168.

[0037] This technical solution defines the main antioxidants as antioxidant 1098 and antioxidant 1010. Antioxidant 1098 is an excellent, low-volatility, hindered phenolic antioxidant with good thermal stability and good compatibility with polymers. Antioxidant 1010 is a multi-functional hindered phenolic antioxidant with good light stability and anti-discoloration properties, and good compatibility with polymers. The auxiliary antioxidants include antioxidant 168, which has good auxiliary antioxidant properties. When used in conjunction with the main antioxidants, the synergistic effect can significantly enhance the anti-aging effect of the main antioxidants, delay the high-temperature aging of hot melt pressure-sensitive adhesives, improve their adhesion durability, and extend their service life.

[0038] To further clarify, the ultraviolet absorber includes any one of benzotriazole ultraviolet absorbers and triazine ultraviolet absorbers.

[0039] The use of either benzotriazole or triazine UV absorbers allows for selection based on actual application requirements, increasing the flexibility of the solution.

[0040] It should be noted that benzotriazole UV absorbers can be UV-P, UV-326, and UV-327, and triazine UV absorbers can be UV-1164 and Mfsorb® 1577; the specific types are not limited here.

[0041] A method for preparing an acrylic ester-based hot melt pressure-sensitive adhesive, comprising the following steps: A. Add the formulated amount of rubber oil, antioxidant, polyvinylpyrrolidone, ultraviolet absorber and 40% of the formulated amount of rosin resin to the reactor, and stir at a temperature of 140-150℃ until completely melted to obtain the first mixture; B. Add the formulated amount of acrylate rubber to the first mixture and stir at a temperature of 140-150°C until completely melted to obtain the second mixture; C. Add the remaining amount of rosin resin to the second mixture and stir at 140-150°C until completely melted to obtain an acrylic ester system hot melt pressure-sensitive adhesive.

[0042] The present technical solution also provides a preparation method for an acrylate-based hot-melt pressure-sensitive adhesive. The preparation method is simple and highly operable, ensuring that the obtained acrylate-based hot-melt pressure-sensitive adhesive can not only achieve bonding durability but also automatically detach without residual glue under water washing conditions.

[0043] The technical solution of the present invention will be further described below through specific embodiments.

[0044] Performance testing: Bonding durability: After coating the acrylate-based hot-melt pressure-sensitive adhesive on the surface of the facing material, a washable label is obtained. After placing the washable label in a constant temperature and humidity environment at 23°C and 50RH% for 12 hours, the holding power is tested according to the test method of GB / T 4851-2014 "Test Method for Adhesive Tape Holding Power". If the washable label does not fall off within 1 hour and the displacement amount ≤ 1.0 mm, the bonding durability is qualified.

[0045] Detachment performance test: After coating the acrylate-based hot-melt pressure-sensitive adhesive on the surface of the facing material, a washable label is obtained. After pasting the washable label on a glass bottle, a test sample is obtained. The test sample is placed in an alkaline solution at a temperature of 80 - 90°C and a pH value of 9 - 11 and soaked for 200 s, and it is observed whether the test sample detaches and whether there is no residual glue on the detachment interface. If the test sample completely detaches and there is no residual glue on the interface, the detachment performance is qualified.

[0046] Example 1 In this example, calculated by mass fraction, the acrylate-based hot-melt pressure-sensitive adhesive includes the following raw materials: 25 parts of naphthenic oil, 25 parts of acrylate rubber, 50 parts of rosin glyceride, 1 part of antioxidant (including antioxidant 1098 and antioxidant 168 with a mass ratio of 1:1), 2 parts of polyvinylpyrrolidone, and 1 part of UV-326; among them, the glass transition temperature of the acrylate rubber is -30°C; calculated by mass percentage, the hydroxyl content in the acrylate rubber is 0.5%. The preparation method of the acrylate-based hot-melt pressure-sensitive adhesive in this example includes the following steps: A. Add the formulated amount of naphthenic oil, antioxidant 1098, antioxidant 168, polyvinylpyrrolidone, UV-326, and 40% of the formulated amount of rosin glyceride to the reaction kettle, and stir at a temperature of 140°C until completely melted to obtain the first mixture. B. Add the formulated amount of acrylate rubber to the first mixture, and stir at a temperature of 145°C until completely melted to obtain the second mixture. C. Add the remaining formulated amount of rosin glyceride to the second mixture, and stir at a temperature of 145°C until completely melted to obtain the acrylate-based hot-melt pressure-sensitive adhesive.

[0047] Example 2 In this embodiment, the acrylic ester system hot melt pressure-sensitive adhesive comprises the following raw materials according to mass parts: 15 parts naphthenic oil, 25 parts acrylic ester rubber, 60 parts rosin pentaerythritol ester, 0.5 parts antioxidant (including antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1), 1 part polyvinylpyrrolidone, and 0.5 parts UV-327; wherein, the glass transition temperature of the acrylic ester rubber is -40℃; and the hydroxyl content in the acrylic ester rubber is 1% according to mass percentage. The preparation method of the acrylic ester system hot melt pressure-sensitive adhesive in this embodiment includes the following steps: A. Add the formulated amounts of naphthenic oil, antioxidant 1010, antioxidant 168, polyvinylpyrrolidone, UV-327, and 40% of the formulated amount of rosin pentaerythritol ester to the reactor and stir at 150°C until completely melted to obtain the first mixture. B. Add the formulated amount of acrylate rubber to the first mixture and stir at 150°C until completely melted to obtain the second mixture; C. Add the remaining amount of rosin pentaerythritol ester to the second mixture and stir at 150°C until completely melted to obtain an acrylic ester system hot melt pressure-sensitive adhesive.

[0048] Example 3 In this embodiment, the acrylic ester system hot melt pressure-sensitive adhesive comprises the following raw materials according to mass percentages: 30 parts naphthenic oil, 30 parts acrylic ester rubber, 40 parts rosin glycerol ester, 1.5 parts antioxidant (including antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1), 3 parts polyvinylpyrrolidone, and 1.5 parts UV-1164; wherein, the glass transition temperature of the acrylic ester rubber is -25°C; and the hydroxyl content in the acrylic ester rubber is 0.8% by mass percentage. The preparation method of the acrylic ester system hot melt pressure-sensitive adhesive in this embodiment includes the following steps: A. Add the formulated amounts of naphthenic oil, antioxidant 1010, antioxidant 168, polyvinylpyrrolidone, UV-1164, and 40% of the formulated amount of rosin glycerol ester to the reaction vessel, and stir at 140°C until completely melted to obtain the first mixture; B. Add the formulated amount of acrylate rubber to the first mixture and stir at 150°C until completely melted to obtain the second mixture; C. Add the remaining amount of rosin glycerol ester to the second mixture and stir at 150°C until completely melted to obtain an acrylic ester system hot melt pressure-sensitive adhesive.

[0049] Comparative Example 1 The preparation method and raw materials of Comparative Example 1 are the same as those of Example 1, except that SBS is used instead of acrylic rubber in the acrylic ester system hot melt pressure sensitive adhesive formulation of Comparative Example 1.

[0050] The performance of the acrylic ester system hot melt pressure-sensitive adhesives used in the examples and comparative examples was tested, and the specific test results are shown in Table 1 below: Table 1. Test results of relevant performance of acrylic ester system hot melt pressure-sensitive adhesive

[0051] As can be seen from the performance test results in the table above, the acrylic ester system hot melt pressure-sensitive adhesive prepared by this technical solution overcomes the limitations of the SBC system hot melt pressure-sensitive adhesive by improving weather resistance and providing a water-washable detachment response mechanism. It can not only achieve durable adhesion, but also automatically detach without residue under water washing conditions.

[0052] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. An acrylic ester-based hot melt pressure-sensitive adhesive, characterized in that, The ingredients, calculated by weight, include the following raw materials: 15-30 parts rubber oil, 20-30 parts acrylate rubber, 0.5-3 parts polyvinylpyrrolidone, 40-60 parts rosin resin, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber.

2. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The glass transition temperature of the acrylate rubber is -40 to -25°C.

3. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The hydroxyl content in the acrylate rubber is 0.5% to 1% by mass percentage.

4. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The rubber oil is a naphthenic oil.

5. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The rosin resin includes either rosin glycerol ester or rosin pentaerythritol ester.

6. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The antioxidants include primary antioxidants and secondary antioxidants, wherein the primary antioxidants include either antioxidant 1098 or antioxidant 1010, and the secondary antioxidants include antioxidant 168.

7. The acrylic ester system hot melt pressure-sensitive adhesive according to claim 1, characterized in that, The ultraviolet absorber includes any one of benzotriazole ultraviolet absorbers and triazine ultraviolet absorbers.

8. A method for preparing an acrylic ester-based hot melt pressure-sensitive adhesive, characterized in that, The method for preparing the acrylate system hot melt pressure-sensitive adhesive according to any one of claims 1 to 7 comprises the following steps: A. Add the formulated amount of rubber oil, antioxidant, polyvinylpyrrolidone, ultraviolet absorber and 40% of the formulated amount of rosin resin to the reactor, and stir at a temperature of 140-150℃ until completely melted to obtain the first mixture; B. Add the formulated amount of acrylate rubber to the first mixture and stir at a temperature of 140-150°C until completely melted to obtain the second mixture; C. Add the remaining amount of rosin resin to the second mixture and stir at 140-150°C until completely melted to obtain an acrylic ester system hot melt pressure-sensitive adhesive.

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