Maleic anhydride grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses a maleic anhydride grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive and a preparation method thereof. Maleic anhydride grafted chlorinated polypropylene with good affinity with a low-surface-energy material and hydrogenated tackifying resin with relatively low surface energy are matched to improve the bonding strength of the adhesive on the surface of the low-surface-energy material; further, an acrylate functional monomer with an epoxy functional group is introduced in the synthesis process of the polyacrylate pressure-sensitive adhesive, and then maleic anhydride grafted chlorinated polypropylene reacts with the epoxy functional group under the action of a tertiary amine catalyst; according to the invention, maleic anhydride is grafted with chlorinated polypropylene, so that maleic anhydride grafted chlorinated polypropylene is connected to an acrylate polymer through chemical bonds, and meanwhile, high-polarity tackifying resin is matched, so that the prepared polyacrylate pressure-sensitive adhesive not only has high bonding strength for materials with relatively high surface energy, but also has very high bonding strength for low-surface-energy materials such as PP (Polypropylene), PE (Polyethylene) and the like; and a primer does not need to be pre-coated on the surface of the low-surface-energy material.

Description

Technical Field

[0001] This invention relates to the field of pressure-sensitive adhesive preparation, and more particularly to a maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Polyacrylate pressure-sensitive adhesives (PSAs) possess advantages such as high bonding strength, a wide range of adjustable tack, low cost, and ease of use, making them one of the most widely used types of PSAs. They play a crucial role in electronics, automobiles, medical devices, industrial equipment, and various everyday consumer goods. Polyacrylate PSAs are primarily manufactured by reacting various acrylate monomers into polyacrylate polymers through free radical polymerization, and then combining them with tackifying resins, curing agents, and other components. To meet diverse application scenarios, researchers have developed a series of polyacrylate PSAs with different properties through various physical or chemical modification methods.

[0003] Current high-adhesion polyacrylate pressure-sensitive adhesives exhibit very high peel strength on materials with high surface energy, such as metals, glass, and plastics like PET, PC, and ABS. However, they show poor adhesion to low-surface-energy and crystalline materials such as PP, PE, or polyolefins (PO). Generally, the lower the surface energy of the object being adhered to, the lower the adhesive strength of the polyacrylate pressure-sensitive adhesive on that surface. The conventional approach is to pre-coat a primer on low-surface-energy materials to improve the adhesive strength of the polyacrylate pressure-sensitive adhesive. However, this method is not only costly and inconvenient to operate, but the primer is also generally an oil-based product that can easily pollute the environment. Therefore, it is necessary to modify conventional high-adhesion polyacrylate pressure-sensitive adhesives to improve their adhesive strength on low-surface-energy materials. Among existing patents, US Patent No. US2017058157A1 describes a chlorinated polypropylene modified polyacrylate pressure-sensitive adhesive with high adhesive strength for materials with low surface energy. This method involves physically blending chlorinated polypropylene into a UV-initiated polyacrylate adhesive. This method requires specialized UV-initiated polymerization equipment, resulting in high equipment costs, and it does not evaluate the compatibility and stability of the physically blended polychlorinated polyolefin with the acrylate adhesive. Chinese application No. CN200480000466.6 describes an acrylic-modified chlorinated polyolefin resin, its manufacturing method, and a coating composition for polyolefin materials containing this resin. This method involves a one-step free radical polymerization reaction of acid-modified chlorinated polypropylene, cyclic ether compounds, and various acrylic monomers to obtain the final product. This product is used in coatings for polyolefin materials, not in polyacrylate pressure-sensitive adhesive products. Therefore, a more complete acrylic pressure-sensitive adhesive solution is urgently needed to address the shortcomings of existing technologies. Summary of the Invention

[0004] To address the problem that existing acrylic pressure-sensitive adhesives cannot be directly used on low surface energy materials due to their poor performance, this invention provides a solution.

[0005] To achieve the above objectives, the present invention provides a maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive, comprising, by weight, 100 parts of a polyacrylate solution with a solid content of 40%, 1-10 parts of maleic anhydride-grafted chlorinated polypropylene, 0.1-0.5 parts of a tertiary amine catalyst, 5-15 parts of a tackifying resin, and 0.5-1.5 parts of a crosslinking agent.

[0006] The 40% solids content polyacrylate solution has the following specific composition: 2-10 parts hard monomer, 20-40 parts soft monomer, 1-8 parts functional monomer, 0.2-5 parts epoxy monomer, 0.05-3 parts initiator, and 40-80 parts solvent.

[0007] As an improved embodiment of this application, the hard monomer is one or more of methyl acrylate, methyl methacrylate, vinyl acetate, acrylonitrile, and isopropyl methacrylate.

[0008] As an improved embodiment of this application, the soft monomer is one or more of isooctyl acrylate, butyl acrylate, and ethyl acrylate.

[0009] As an improved embodiment of this application, the functional monomer is one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and acrylamide.

[0010] As an improved embodiment of this application, the epoxy monomer is one or more of glycidyl methacrylate, 2,3-epoxypropyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 3,4-epoxycyclohexyl methacrylate.

[0011] As an improved embodiment of this application, the initiator is one or both of azobisisobutyronitrile and benzoyl peroxide.

[0012] As an improved embodiment of this application, the tackifying resin is one or more of terpene phenol resin, rosin terpene phenol resin, hydrogenated rosin resin and petroleum resin.

[0013] As an improved embodiment of this application, maleic anhydride-grafted chlorinated polypropylene is one or both of Toyobo F-2P and F-6P from Japan.

[0014] As an improved embodiment of this application, the tertiary amine catalyst is a delayed tertiary amine catalyst.

[0015] This application also provides a method for preparing a high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene, comprising the following steps:

[0016] Soft monomers, hard monomers, functional monomers and monomers containing epoxy groups are mixed evenly in a preset ratio to obtain a monomer mixture.

[0017] Weigh the monomer mixture, the first type of initiator in a predetermined ratio, and the organic solvent accounting for 90-95% of the total solvent mass, add them to the reaction vessel and mix them evenly; heat the mixture to 75℃ to 95℃ and react for 3-6 hours.

[0018] The remaining organic solvent and a predetermined proportion of the second type of initiator are added to the reactor. After reacting for 2-5 hours, a polyacrylate solution with a solid content of 40% is obtained. Then, maleic anhydride-grafted chlorinated polypropylene and tertiary amine catalyst, which are pre-dissolved in the remaining solvent, are added to the reactor and reacted at 80-90°C for 1-3 hours. Finally, a predetermined amount of tackifying resin is added to the reactor. After the tackifying resin is completely dissolved and stirred evenly, the high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene is obtained.

[0019] The beneficial effects of this invention are as follows: Compared with the prior art, the maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive and its preparation method provided by this invention improve the adhesive strength on low surface energy materials by using acrylate monomers with low surface energy and hydrogenated tackifying resins with low surface energy, thus ensuring the bonding strength on low surface energy materials. Furthermore, during the synthesis of the polyacrylate pressure-sensitive adhesive, acrylates or similar functional monomers with epoxy functional groups are introduced. Then, maleic anhydride-grafted chlorinated polypropylene reacts with the epoxy functional groups under the action of a tertiary amine catalyst, thereby chemically linking the maleic anhydride-grafted chlorinated polypropylene to the acrylate polymer. This not only provides high bonding strength to materials with high surface energy, but also provides very high bonding strength to low surface energy materials such as PP and PE, and eliminates the need for pre-coating the low surface energy material surface with a primer. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0021] To more clearly illustrate the present invention, the invention will be further described below with reference to the accompanying drawings.

[0022] In the following description, specific examples are given to provide a more in-depth understanding of the invention. It is obvious that the described embodiments are merely some, not all, of the embodiments of the invention. It should be understood that the specific embodiments described are for illustrative purposes only and are not intended to limit the scope of the invention.

[0023] It should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the said feature, integral, step, operation, element, or component, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, or combinations thereof.

[0024] To address the aforementioned technical problems, this application provides a maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive. Please refer to the attached document. Figure 1 A maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive comprises, by weight, 100 parts of a 40% solid content polyacrylate solution, 1-10 parts of maleic anhydride-grafted chlorinated polypropylene, 0.1-0.5 parts of a tertiary amine catalyst, 5-15 parts of a tackifying resin, and 0.5-1.5 parts of a crosslinking agent; wherein, the 40% solid content polyacrylate solution specifically comprises: 2-10 parts of hard monomers, 20-40 parts of soft monomers, 1-8 parts of functional monomers, 0.2-5 parts of epoxy monomers, 0.05-3 parts of initiator, and 40-80 parts of solvent.

[0025] By combining acrylate monomers with low surface energy with hydrogenated tackifying resins with low surface energy, the adhesive strength of the adhesive on low surface energy materials is improved, ensuring bonding strength on such materials. Furthermore, during the synthesis of polyacrylate pressure-sensitive adhesive, acrylates or similar functional monomers with epoxy functional groups are introduced. Then, maleic anhydride-grafted chlorinated polypropylene reacts with the epoxy functional groups under the action of a tertiary amine catalyst, thereby chemically linking the maleic anhydride-grafted chlorinated polypropylene to the acrylate polymer. This not only provides high bonding strength to materials with high surface energy but also exhibits very high bonding strength to low surface energy materials such as PP and PE, without requiring a pre-coating of the low surface energy material surface.

[0026] As a specific embodiment of this application, the hard monomer is one or more of methyl acrylate, methyl methacrylate, vinyl acetate, acrylonitrile, and isopropyl methacrylate.

[0027] As a specific embodiment of this application, the soft monomer is one or more of isooctyl acrylate, butyl acrylate, and ethyl acrylate.

[0028] As a specific embodiment of this application, the functional monomer is one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and acrylamide.

[0029] In one specific embodiment of this application, the epoxy monomer is one or more of glycidyl methacrylate, 2,3-epoxypropyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 3,4-epoxycyclohexyl methacrylate. The introduction of the epoxy monomer facilitates its reaction with the maleic anhydride groups of maleic anhydride-grafted chlorinated polypropylene, thereby connecting the maleic anhydride-grafted chlorinated polypropylene to the polyacrylate polymer backbone. Furthermore, the epoxy functional groups can also react with the curing agent to enhance the cohesive strength of the polyacrylate pressure-sensitive adhesive. In addition, the epoxy functional groups in the adhesive can also react with active groups such as hydroxyl and carboxyl groups on the substrate, enhancing the adhesion of the polyacrylate pressure-sensitive adhesive to substrates such as PET films and PI films.

[0030] As a specific embodiment of this application, the initiator is one or both of azobisisobutyronitrile and benzoyl peroxide.

[0031] As a specific embodiment of this application, the tackifying resin is a terpene phenol resin; such as Detophene T115 and Detophene from DRT (LesDerives Resinique et Terpeniques) in France. T150; or rosin terpene phenol resin, such as LT120 and LT150 from Wuzhou Litai Synthetic Resin Co., Ltd. of Guangxi Zhuang Autonomous Region; or hydrogenated rosin resin, such as Foral105-E and Foral85-E from Eastman Chemical Company of the United States; or petroleum resin, such as S100, S110, P100, P125, and P140 from Idemitsu Chemical of Japan; select one or two of the above materials as tackifying resins; terpene phenol resin and rosin terpene phenol resin have strong polarity and can promote the bonding strength of polyacrylate pressure-sensitive adhesive on inorganic materials such as steel plates, aluminum plates, and glass, as well as plastic materials with high surface energy such as PC, PI, PET, and ABS. Hydrogenated rosin resin and petroleum resin have weak polarity and can improve the bonding strength of polyacrylate pressure-sensitive adhesive on interfaces with low surface energy such as PP and PE.

[0032] As a specific embodiment of this application, maleic anhydride-grafted chlorinated polypropylene is one or both of Toyobo F-2P and F-6P from Japan. The main reason for selecting maleic anhydride-grafted chlorinated polypropylene modified polyacrylate pressure-sensitive adhesive is that maleic anhydride-grafted chlorinated polypropylene contains maleic anhydride functional groups, which can chemically react with the epoxy functional groups in the polyacrylate pressure-sensitive adhesive, thereby chemically linking the maleic anhydride-grafted chlorinated polypropylene to the polyacrylate molecular chain. At the same time, the polypropylene segments in the maleic anhydride-grafted chlorinated polypropylene have good affinity with low surface energy materials (PP, PE, etc.), which can further improve the adhesion strength of the polyacrylate pressure-sensitive adhesive at the interface of low surface energy materials.

[0033] As a specific embodiment of this application, the tertiary amine catalyst is a delayed tertiary amine catalyst.

[0034] As a specific embodiment of this application, the solvent is one or more of ethyl acetate, toluene, and acetone.

[0035] As a specific embodiment of this application, the curing agent is one or more of isocyanate, epoxy resin, aluminum acetylacetonate and amino resin. Commonly used isocyanate curing agents mainly include polymers, hydrides or modifiers of toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI). The commonly used epoxy curing agent is Huntsman GA-240.

[0036] As a general inventive concept, this application also provides a method for preparing a high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene, comprising the following steps:

[0037] S1. Mix the soft monomer, hard monomer, functional monomer and epoxy group-containing monomer in a preset ratio to obtain a monomer mixture;

[0038] S2. Weigh the monomer mixture, the first type of initiator in a predetermined ratio, and the organic solvent accounting for 90-95% of the total solvent mass, add them to the reaction vessel and mix them evenly; heat the mixture to 75℃ to 95℃ and react for 3-6 hours.

[0039] S3. Add the remaining organic solvent and the second type of initiator in a preset ratio to the reactor. After reacting for 2-5 hours, a polyacrylate solution with a solid content of 40% is obtained. Then, add the maleic anhydride-grafted chlorinated polypropylene and tertiary amine catalyst that have been pre-dissolved in the remaining solvent to the reactor. React at 80-90°C for 1-3 hours. Finally, add the preset mass of tackifying resin to the reactor. After the tackifying resin is completely dissolved and stirred evenly, the high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene is obtained.

[0040] The features and performance of the present invention will be further described in detail below with reference to embodiments;

[0041] Example 1

[0042] (1) Mix 28.8 parts by weight of butyl acrylate, 0.08 parts by weight of hydroxyethyl acrylate, 3.52 parts by weight of isooctyl acrylate, 5.2 parts by weight of methyl acrylate, 0.8 parts by weight of glycidyl methacrylate, 1.6 parts by weight of acrylic acid, 60 parts by weight of ethyl acetate, and 0.08 parts by weight of benzoyl peroxide evenly, transfer the mixture to a four-necked reaction flask equipped with a thermometer and a stirrer, heat it to the boiling point and react for 4 hours; add 5 parts by weight of ethyl acetate and 0.024 parts by weight of azobisisobutyronitrile, continue to react for 3 hours, and then cool it to room temperature to obtain a polyacrylate solution with a solid content of 40%.

[0043] (2) Take 100 parts by mass of 40% solid content polyacrylate solution and keep it at a constant temperature of 70℃. Add 5 parts by mass of maleic anhydride grafted polyacrylate dissolved in ethyl acetate to a solid content of 40% to the reaction flask and stir for 5 min. Then add 0.2 parts by mass of tertiary amine catalyst U-CAT SA102 to the reaction flask, stir for 10 min and then heat to 85℃ and react for 2 h to obtain a maleic anhydride grafted polyacrylate modified polyacrylate solution with a solid content of 40%.

[0044] (3) Weigh 5 parts by weight of terpene phenol resin of model Dertophene T150, 7 parts by weight of petroleum resin of model S100 and 3 parts by weight of hydrogenated rosin resin of model Foral 105-E. After completely dissolving them with 22.5 parts by weight of ethyl acetate, add them to 100g of maleic anhydride grafted polypropylene modified polyacrylate solution with a solid content of 40% to obtain a maleic anhydride grafted polypropylene modified polyacrylate pressure-sensitive adhesive solution with a solid content of 40%. Add 1 part by weight of Desmodur L75 curing agent from Bayer, Germany to 100 parts by weight of maleic anhydride grafted polypropylene modified polyacrylate pressure-sensitive adhesive solution. After stirring evenly, use an automatic coating machine to evenly coat it onto a PET film with a thickness of 25μm. Bake at 130℃ for 3min, control the dry adhesive thickness at 25μm, and after bonding with a 50um silicone oil release film, place it in an oven at 60℃ for 48h to cure, and the pressure-sensitive adhesive is obtained.

[0045] Example 2

[0046] Referring to Example 1, the difference from Example 1 is that the amount of glycidyl methacrylate (GMA) added is changed from 2 parts to 4 parts. The remaining technical features are the same as in Example 1.

[0047] Example 3

[0048] Referring to Example 1, the difference from Example 1 is that the epoxy monomer was changed from glycidyl methacrylate (GMA) to the same mass of 3,4-epoxycyclohexylmethyl methacrylate. All other technical features are the same as in Example 1.

[0049] Example 4

[0050] Referring to Example 2, the difference from Example 2 is that the epoxy monomer was changed from glycidyl methacrylate (GMA) to the same mass of 3,4-epoxycyclohexyl methacrylate. All other technical features are the same as in Example 2.

[0051] Example 5

[0052] Referring to Example 1, the difference is that the amount of maleic anhydride-grafted chlorinated polypropylene F-2P added is adjusted from parts by mass to 2 parts by mass. All other technical features are the same as in Example 1.

[0053] Example 6

[0054] Referring to Example 1, the difference from Example 1 is that 1 part by mass of Desmodur L75 curing agent is replaced with 0.8 parts by mass of Huntsman GA-240 solution (10% solid content) dissolved in ethyl acetate. The remaining technical features are the same as in Example 1.

[0055] Example 7

[0056] Referring to Example 1, the difference from Example 1 is that the terpene phenol resin of type Dertophene T150 is replaced with rosin terpene phenol resin of type LT-150. The remaining technical features are the same as in Example 1.

[0057] Example 8

[0058] Referring to Example 1, the difference from Example 1 is that 5 parts by weight of terpene phenol resin of type Dertophene T150 are replaced with 7 parts by weight of rosin terpene phenol resin of type LT120, and 7 parts by weight of petroleum resin of type S100 are replaced with 5 parts by weight of petroleum resin of type P125. The remaining technical features are the same as those in Example 1.

[0059] Comparative Example 1

[0060] Referring to Example 1, the difference from Example 1 is that maleic anhydride-grafted chloropropene chloride F-2P and the tertiary amine catalyst U-CAT SA102 are not added. The remaining technical features are the same as in Example 1.

[0061] Comparative Example 2

[0062] Referring to Example 1, the difference from Example 1 is that maleic anhydride-grafted chlorinated polypropylene F-2P is added for physical blending at room temperature, and the tertiary amine catalyst U-CAT SA102 is not added. All other technical features are the same as in Example 1.

[0063] Comparative Example 3

[0064] Referring to Example 1, the difference from Example 1 is that hydrogenated rosin resin and petroleum resin are not added, and 15 parts by weight of tackifying resin are all made of the highly polar terpene phenol resin Dertophene T150. The remaining technical features are the same as in Example 1.

[0065] Comparative Example 4

[0066] Referring to Example 1, the difference from Example 1 is that no terpene phenolic resin or rosin terpene phenolic resin is added, and all 15 parts by weight of the tackifying resin are low-polarity hydrogenated rosin resin Foral 105-E. All other technical features are the same as in Example 1.

[0067] The pressure-sensitive adhesive products of Examples 1-8 and Comparative Examples 1-4 were obtained and their performance indicators were tested. The test items referenced the following standards:

[0068] 180° peel strength test: Measured according to GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tapes". SUS304 stainless steel plate with special surface treatment and PP plate were selected as test plates.

[0069] Initial tack test: The initial tack performance of the tape is tested using the ring method, referring to GB / T 31125-2014 "Test Method for Initial Tack of Adhesive Tapes - Ring Method".

[0070] 70℃ Holding Strength Test: Holding strength is a test method that reflects the cohesive strength of adhesives. It is determined in accordance with GB / T 4851-2014 "Test Method for Adhesive Tape Holding Strength". Observe whether the weight falls off or the distance (mm) the tape moves on the test plate after 24 hours of hanging the weight.

[0071] Please refer to Table 1 below for specific experimental data:

[0072] Table 1

[0073]

[0074] The table above shows that when polyacrylate pressure-sensitive adhesive is not modified with maleic anhydride-grafted chlorinated polypropylene, it exhibits poor adhesion and low peel strength on low surface energy materials such as PP and PE. When maleic anhydride-grafted chlorinated polypropylene is physically blended with the polyacrylate prepolymer without chemical bonding, the adhesive shows high peel strength on low surface energy PP, but poor holding power at 70°C, indicating poor cohesive strength. Comparative Example 3, combined with Example 1, shows that the polyacrylate pressure-sensitive adhesive prepared entirely with highly polar terpene phenol resin as the tackifying resin exhibits high peel strength on steel surfaces but low peel strength on low surface energy PP surfaces. Comparative Example 4, combined with Example 1, shows that the polyacrylate pressure-sensitive adhesive prepared entirely with low polar hydrogenated rosin resin as the tackifying resin exhibits high peel strength on low surface energy PP surfaces but low peel strength on steel surfaces.

[0075] As can be seen, embodiments 1-8 of this application have stronger comprehensive performance parameters and are better applicable to different surface energy materials, especially low surface energy materials.

[0076] The advantages of this invention are:

[0077] By grafting maleic anhydride onto chlorinated polypropylene and reacting it with epoxy functional groups under the action of a tertiary amine catalyst, maleic anhydride-grafted chlorinated polypropylene is chemically bonded to acrylate polymers. The resulting polyacrylate pressure-sensitive adhesive, prepared in combination with tackifying resin and curing agent, not only exhibits high bonding strength to materials with high surface energy, but also very high bonding strength to materials with low surface energy such as PP and PE, without the need for pre-coating with a primer on low surface energy materials.

[0078] The above-disclosed embodiments are merely a few specific examples of the present invention, but the present invention is not limited thereto. Any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive, characterized in that, It comprises, by weight, 100 parts of a 40% solid content polyacrylate solution, 1-10 parts of maleic anhydride-grafted chlorinated polypropylene, 0.1-0.5 parts of a tertiary amine catalyst, 5-15 parts of a tackifying resin, and 0.5-1.5 parts of a crosslinking agent; The 40% solids content polyacrylate solution has the following specific composition: 2-10 parts hard monomer, 20-40 parts soft monomer, 1-8 parts functional monomer, 0.2-5 parts epoxy monomer, 0.05-3 parts initiator, and 40-80 parts solvent.

2. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the hard monomer is one or more of methyl acrylate, methyl methacrylate, vinyl acetate, acrylonitrile, and isopropyl methacrylate.

3. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the soft monomer is one or more of isooctyl acrylate, butyl acrylate, and ethyl acrylate.

4. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the functional monomer is one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and acrylamide.

5. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the epoxy monomer is one or more of glycidyl methacrylate, 2,3-epoxypropyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 3,4-epoxycyclohexyl methacrylate.

6. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the initiator is one or both of azobisisobutyronitrile and benzoyl peroxide.

7. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the tackifying resin is one or more of terpene phenol resin, rosin terpene phenol resin, hydrogenated rosin resin, and petroleum resin.

8. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the maleic anhydride-grafted chlorinated polypropylene is one or both of Toyobo F-2P and F-6P from Japan.

9. The maleic anhydride-grafted chlorinated polypropylene modified high-viscosity polyacrylate pressure-sensitive adhesive according to claim 1, wherein the tertiary amine catalyst is a delayed-type tertiary amine catalyst.

10. A method for preparing a high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene, characterized in that, Includes the following steps: Soft monomers, hard monomers, functional monomers and monomers containing epoxy groups are mixed evenly in a preset ratio to obtain a monomer mixture. Weigh the monomer mixture, the first type of initiator in a predetermined proportion, and the organic solvent accounting for 90-95% of the total solvent mass, add them to the reaction vessel and mix them evenly; heat the mixture to 75℃ to 95℃ and react for 3-6 hours; The remaining organic solvent and a predetermined proportion of the second type of initiator are added to the reactor. After reacting for 2-5 hours, a polyacrylate solution with a solid content of 40% is obtained. Then, maleic anhydride-grafted chlorinated polypropylene and tertiary amine catalyst, which are pre-dissolved in the remaining solvent, are added to the reactor and reacted at 80-90°C for 1-3 hours. Finally, a predetermined amount of tackifying resin is added to the reactor. After the tackifying resin is completely dissolved and stirred evenly, the high-viscosity polyacrylate pressure-sensitive adhesive modified with maleic anhydride-grafted chlorinated polypropylene is obtained.

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