Long-life anti-aging acrylic pressure-sensitive adhesive protective film and preparation method thereof

Abstract

The invention relates to the technical field of adhesive materials, and discloses a long-life anti-aging acrylic pressure-sensitive adhesive protective film and a preparation method thereof, the long-life anti-aging acrylic pressure-sensitive adhesive protective film comprises the following raw materials by weight: 50-70 parts of a modified acrylic emulsion, 5-8 parts of a nanometer material, 0.1-0.3 part of a surface treating agent, 1-3 parts of a photoinitiator, 0.5-1 part of an antioxidant, and 0.2-0.5 part of a cross-linking agent. The acrylic pressure-sensitive adhesive protective film has good ultraviolet resistance and aging resistance, by adding a surface-treated nano material, the tolerance to a high-temperature environment is improved, the service life is effectively prolonged, meanwhile, the aging resistance in the high-temperature environment can be effectively improved, and the working performance is excellent and stable.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesive materials, and particularly to a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film and a preparation method thereof. Background Art

[0002] With the continuous development of technology, the performance requirements for protective films in various products such as electronic devices, optical instruments, and automotive parts are getting higher and higher. Acrylic pressure-sensitive adhesive protective films have been widely used in various fields due to their advantages such as good initial adhesiveness, peel strength, and transparency. However, during long-term use, traditional pressure-sensitive adhesive protective films are easily affected by environmental factors such as light, temperature, and humidity, resulting in their aging and performance degradation, which seriously affects the service life and protection effect of the protective film. Therefore, it is of great practical significance to develop a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film and a preparation method thereof.

[0004] To achieve the above object, the present invention provides the following technical solutions: A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film is composed of the following raw materials in parts by weight: 50-70 parts of modified acrylic emulsion, 5-8 parts of nano material, 0.1-0.3 part of surface treatment agent, 1-3 parts of photoinitiator, 0.5-1 part of antioxidant, 0.2-0.5 part of crosslinking agent.

[0005] Further, the preparation method of the modified acrylic emulsion includes the following steps: A1. Place diethylenetriamine in a three-necked flask, cool it in an ice-water bath, pass nitrogen, slowly add acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol, react at 20-30 °C, transfer it to the egg-shaped flask of a rotary evaporator, remove methanol under reduced pressure, and raise the temperature to 120-160 °C for a reduced-pressure reaction for 2-8 h to obtain an amino-terminated acrylic emulsion; A2. Add the amino-terminated acrylic emulsion to a solvent, stir evenly, slowly add benzotriazole-isocyanate and the catalyst dibutyltin dilaurate under stirring, react at 50-70 °C for 2-8 h, cool to room temperature after the reaction, and remove the solvent by reduced-pressure distillation to obtain a modified acrylic emulsion.

[0006] Further, the mass ratio of diethylenetriamine, acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol in step A1 is 1:0.6-0.8:0.4-0.6:0.4-0.6:1.5-3; In step A2, the mass ratio of the terminal amino acrylic emulsion, benzotriazole-isocyanate, and the catalyst dibutyltin dilaurate is 1: 0.1-0.3: 0.01-0.03; the solvent is one of toluene, N, N-dimethylformamide, and tetrahydrofuran.

[0007] Furthermore, the preparation method of benzotriazole-isocyanate includes the following steps: B1. Dissolve benzotriazole in anhydrous dichloromethane, cool it to 0-5 °C, slowly add tert-butyldimethylchlorosilane and imidazole, stir evenly, warm it up to 20-30 °C, react for 2-4 h. After the reaction, add saturated brine for quenching, stir for 5-10 min, transfer to a separatory funnel, let it stand for layering, collect the organic phase and dry it with anhydrous sodium sulfate for 2-3 h. After filtration, remove the solvent by distillation under reduced pressure to obtain tert-butyldimethylchlorosilane-benzotriazole; B2. Add tert-butyldimethylchlorosilane-benzotriazole to anhydrous tetrahydrofuran, stir to dissolve it. At a low temperature of -60~-80 °C, slowly add n-butyllithium, stir and react for 1-2 h, then slowly add ethylene oxide, gradually warm it up to 0-5 °C, stir and react for 2-4 h. Slowly add 10% dilute sulfuric acid to adjust the pH to 2-3, stir at 20-30 °C for 1-2 h, extract with dichloromethane, combine the organic phases, wash with saturated sodium bicarbonate solution to remove the residual acid, then wash with saturated brine, dry with anhydrous sodium sulfate, and remove the solvent by distillation under reduced pressure to obtain tert-butyldimethylchlorosilane-benzotriazole containing hydroxyethyl; B3. Add tert-butyldimethylchlorosilane-benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate to anhydrous toluene, place it in a water bath at 60-80 °C, stir and react for 4-8 h, remove the solvent by distillation under reduced pressure to obtain a carbamate intermediate containing benzotriazole; B4. Add tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole to tetrahydrofuran, stir and react at 20-30 °C for 2-4 h. After the reaction, add saturated brine for quenching, extract with dichloromethane, wash with saturated brine, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain benzotriazole-isocyanate.

[0008] Furthermore, in step B1, the mass ratio of benzotriazole, tert-butyldimethylchlorosilane, and imidazole is 1: 1-1.3: 1.2-1.5; In step B2, the mass ratio of tert-butyldimethylchlorosilane-benzotriazole, n-butyllithium, and ethylene oxide is 1: 0.1-0.3: 0.3-0.5; In step B3, the mass ratio of tert-butyldimethylchlorosilane-benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate is 1: 0.8-1.2: 0.01-0.05; In step B4, the mass ratio of tetrabutylammonium fluoride to the carbamate intermediate containing benzotriazole is 1.2 - 1.5:1.

[0009] Further, the photoinitiator is one of 184, 1173 or benzophenone.

[0010] Further, the antioxidant is one of 1010, 168 or DLTP.

[0011] Further, the crosslinking agent is one of trimethylolpropane triacrylate, pentaerythritol triacrylate or hexamethylene diisocyanate.

[0012] Further, a preparation method of a long - life and aging - resistant acrylic pressure - sensitive adhesive protective film includes the following steps: Mix the surface treatment agent with the nanomaterial, stir at 80 - 100 °C for 2 - 3 h, cool to room temperature and then add it to the modified acrylic emulsion, stir evenly, then successively add the photoinitiator, antioxidant, crosslinking agent, stir for 30 - 60 min, coat it on the substrate, and cure it by ultraviolet irradiation for 1 - 3 min to obtain the long - life and aging - resistant acrylic pressure - sensitive adhesive protective film; The surface treatment agent is one of γ - aminopropyltriethoxysilane, γ - glycidyletheroxypropyltrimethoxysilane or γ - methacryloxypropyltrimethoxysilane; The nanomaterial is one of nano - aluminum hydroxide, nano - magnesium hydroxide or nano - montmorillonite.

[0013] A long - life and aging - resistant acrylic pressure - sensitive adhesive protective film is made of a modified acrylic emulsion, a nanomaterial, a surface treatment agent, a photoinitiator, an antioxidant and a crosslinking agent.

[0014] The modified acrylic emulsion is prepared by modifying the mixed emulsion of acrylic acid, methyl acrylate and hydroxyethyl acrylate with benzotriazole - isocyanate. The preparation of benzotriazole - isocyanate is to react tert - butyldimethylchlorosilane with the nitrogen atom of benzotriazole, then react with n - butyllithium to form a lithium salt, react with ethylene oxide, and through acid hydrolysis, obtain tert - butyldimethylchlorosilane - benzotriazole containing a hydroxyl group. Then it undergoes an acylation reaction with diphenylmethane diisocyanate, and finally deprotection is carried out with tetrabutylammonium fluoride to remove the tert - butyldimethylsilyl protecting group to obtain benzotriazole - isocyanate. The modified acrylic emulsion undergoes end - amino hyperbranched polymerization with acrylic acid, methyl acrylate and hydroxyethyl acrylate, and undergoes a nucleophilic addition reaction with benzotriazole - isocyanate to produce urea bonds, thus obtaining the modified acrylic emulsion. The modified acrylic emulsion can effectively absorb ultraviolet rays, capture free radicals, and improve the aging resistance of the pressure - sensitive adhesive protective film.

[0015] The acrylic pressure-sensitive adhesive protective film of the present invention has good ultraviolet and aging resistance. By adding surface-treated nanomaterials, its tolerance to high-temperature environments is improved, the service life is effectively extended, and at the same time, its aging resistance characteristics in high-temperature environments can be effectively enhanced, with excellent and stable working performance. Detailed implementation manners

[0016] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0017] The formula components of the long-life and aging-resistant acrylic pressure-sensitive adhesive protective film of the present invention are all commercially available without special instructions;

[0018] Embodiment 1: A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film is composed of the following raw materials in parts by weight: 50 parts of modified acrylic emulsion, 5 parts of nanomaterials, 0.1 part of surface treatment agent, 1 part of photoinitiator, 0.5 part of antioxidant, 0.2 part of crosslinking agent.

[0019] The surface treatment agent is γ-aminopropyltriethoxysilane; The nanomaterials are nano-aluminum hydroxide; The photoinitiator is 184; The antioxidant is 1010; The crosslinking agent is trimethylolpropane triacrylate.

[0020] In step A1, the mass ratio of diethylenetriamine, acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol is 1:0.6:0.4:0.4:1.5; In step A2, the mass ratio of the terminal amino acrylic emulsion, benzotriazole-isocyanate, and the catalyst dibutyltin dilaurate is 1:0.1:0.01; the solvent is toluene; In step B1, the mass ratio of benzotriazole, tert-butyldimethylchlorosilane, and imidazole is 1:1:1.2; In step B2, the mass ratio of tert-butyldimethylchlorosilane-benzotriazole, n-butyllithium, and ethylene oxide is 1:0.1:0.3; In step B3, the mass ratio of 2-hydroxyethyl tert-butyldimethylchlorosilane-benzotriazole, diphenylmethane diisocyanate, and dibutyltin dilaurate is 1:0.8:0.01; In step B4, the mass ratio of tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole is 1.2:1.

[0021] A preparation method of a long - life and aging - resistant acrylic pressure - sensitive adhesive protective film, comprising the following steps: Mix the surface treatment agent with the nanomaterial, stir at 80 °C for 2 h, cool to room temperature and then add it to the modified acrylic emulsion, stir evenly, then successively add a photoinitiator, an antioxidant, and a cross - linker, stir for 30 min, coat it on a substrate, and cure it by ultraviolet irradiation for 1 min to obtain a long - life and aging - resistant acrylic pressure - sensitive adhesive protective film.

[0022] The preparation method of the modified acrylic emulsion comprises the following steps: A1. Place diethylenetriamine in a three - necked flask, cool it in an ice - water bath, pass nitrogen, slowly add acrylic acid, methyl acrylate, 2 - hydroxyethyl acrylate, and methanol, react at 20 °C, transfer it to the egg - shaped flask of a rotary evaporator, remove methanol under reduced pressure, raise the temperature to 120 °C and react under reduced pressure for 2 h to obtain an amino - terminated acrylic emulsion; A2. Add the amino - terminated acrylic emulsion to a solvent, stir evenly, slowly add benzotriazole - isocyanate and the catalyst dibutyltin dilaurate under stirring, react at 50 °C for 2 h, cool to room temperature after the reaction, and remove the solvent by distillation under reduced pressure to obtain a modified acrylic emulsion.

[0023] The preparation method of benzotriazole - isocyanate comprises the following steps: B1. Dissolve benzotriazole in anhydrous dichloromethane, cool to 0 °C, slowly add tert - butyldimethylchlorosilane and imidazole, stir evenly, raise the temperature to 20 °C, react for 2 h, add saturated brine for quenching after the reaction, stir for 5 min, transfer to a separatory funnel, let it stand for layering, collect the organic phase and dry it with anhydrous sodium sulfate for 2 h, filter and remove the solvent by distillation under reduced pressure to obtain tert - butyldimethylchlorosilane - benzotriazole; B2. Add tert - butyldimethylchlorosilane - benzotriazole to anhydrous tetrahydrofuran, stir to dissolve, at a low temperature of - 60 °C, slowly add n - butyllithium, stir and react for 1 h, then slowly add ethylene oxide, gradually raise the temperature to 0 °C, stir and react for 2 h, slowly add 10% dilute sulfuric acid to adjust the pH to 2, stir at 20 °C for 1 h, extract with dichloromethane, combine the organic phases, wash with saturated sodium bicarbonate solution to remove the residual acid, then wash with saturated brine, dry with anhydrous sodium sulfate, and remove the solvent by distillation under reduced pressure to obtain tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl; B3. Add tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate to anhydrous toluene, place it in a 60 °C water bath, stir and react for 4 h, remove the solvent by distillation under reduced pressure to obtain a carbamate intermediate containing benzotriazole; B4. Add tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole into tetrahydrofuran, stir and react at 20 °C for 2 h. After the reaction, add saturated brine to quench the reaction, extract with dichloromethane, wash with saturated brine, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain benzotriazole-isocyanate.

[0024] Example 2: A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film is composed of the following raw materials in parts by weight: 60 parts of modified acrylic emulsion, 6 parts of nanomaterials, 0.2 part of surface treatment agent, 2 parts of photoinitiator, 0.8 part of antioxidant, 0.3 part of crosslinking agent.

[0025] The surface treatment agent is γ-glycidoxypropyltrimethoxysilane; The nanomaterials are nanomagnesium hydroxide; The photoinitiator is 1173; The antioxidant is 168; The crosslinking agent is pentaerythritol triacrylate.

[0026] In step A1, the mass ratio of diethylenetriamine, acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol is 1:0.7:0.5:0.5:2; In step A2, the mass ratio of the terminal amino acrylic emulsion, benzotriazole-isocyanate, and the catalyst dibutyltin dilaurate is 1:0.2:0.02; the solvent is N,N-dimethylformamide; In step B1, the mass ratio of benzotriazole, tert-butyldimethylchlorosilane, and imidazole is 1:1.2:1.3; In step B2, the mass ratio of tert-butyldimethylchlorosilane-benzotriazole, n-butyllithium, and ethylene oxide is 1:0.2:0.4; In step B3, the mass ratio of 2-hydroxyethyl tert-butyldimethylchlorosilane-benzotriazole, diphenylmethane diisocyanate, and dibutyltin dilaurate is 1:1:0.03; In step B4, the mass ratio of tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole is 1.3:1.

[0027] A preparation method of a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film includes the following steps: Mix the surface treatment agent and the nanomaterials, stir at 90 °C for 2.5 h, cool to room temperature and then add them to the modified acrylic emulsion, stir evenly, then add the photoinitiator, antioxidant, and crosslinking agent in sequence, stir for 45 min, coat on the substrate, and cure by ultraviolet irradiation for 2 min to obtain the long-life and aging-resistant acrylic pressure-sensitive adhesive protective film.

[0028] The preparation method of the modified acrylic emulsion includes the following steps: A1. Place diethylenetriamine in a three-necked flask, cool it in an ice-water bath, pass nitrogen, slowly add acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol, react at 25 °C, transfer it to the egg-shaped flask of a rotary evaporator, remove methanol under reduced pressure, raise the temperature to 140 °C and react under reduced pressure for 5 h to obtain an amino-terminated acrylic emulsion; A2. Add the amino-terminated acrylic emulsion to a solvent, stir evenly, slowly add benzotriazole-isocyanate and the catalyst dibutyltin dilaurate under stirring, react at 60 °C for 5 h, cool to room temperature after the reaction, and remove the solvent by distillation under reduced pressure to obtain a modified acrylic emulsion.

[0029] The preparation method of benzotriazole-isocyanate includes the following steps: B1. Dissolve benzotriazole in anhydrous dichloromethane, cool to 3 °C, slowly add tert-butyldimethylchlorosilane and imidazole, stir evenly, raise the temperature to 25 °C, react for 3 h, add saturated brine for quenching after the reaction, stir for 8 min, transfer to a separatory funnel, let it stand for layer separation, collect the organic phase and dry it with anhydrous sodium sulfate for 2.5 h, filter and remove the solvent by distillation under reduced pressure to obtain tert-butyldimethylchlorosilane-benzotriazole; B2. Add tert-butyldimethylchlorosilane-benzotriazole to anhydrous tetrahydrofuran, stir to dissolve, at a low temperature of -70 °C, slowly add n-butyllithium, stir and react for 1.5 h, then slowly add ethylene oxide, gradually raise the temperature to 3 °C, stir and react for 3 h, slowly add 10% dilute sulfuric acid, adjust the pH to 3, stir at 25 °C for 1.5 h, extract with dichloromethane, combine the organic phases, wash with saturated sodium bicarbonate solution to remove the residual acid, then wash with saturated brine, dry with anhydrous sodium sulfate, and remove the solvent by distillation under reduced pressure to obtain tert-butyldimethylchlorosilane-benzotriazole containing hydroxyethyl; B3. Add tert-butyldimethylchlorosilane-benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate to anhydrous toluene, place it in a 70 °C water bath, stir and react for 6 h, and remove the solvent by distillation under reduced pressure to obtain a carbamate intermediate containing benzotriazole; B4. Add tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole to tetrahydrofuran, stir and react at 25 °C for 3 h, add saturated brine for quenching after the reaction, extract with dichloromethane, wash with saturated brine, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain benzotriazole-isocyanate.

[0030] Example 3: A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film is composed of the following raw materials in parts by weight: 70 parts of modified acrylic emulsion, 8 parts of nanomaterials, 0.3 part of surface treatment agent, 3 parts of photoinitiator, 1 part of antioxidant, 0.5 part of crosslinking agent.

[0031] The surface treatment agent is γ-methacryloxypropyltrimethoxysilane; The nanomaterial is nanometer montmorillonite; The photoinitiator is benzophenone; The antioxidant is DLTP; The crosslinking agent is hexamethylene diisocyanate.

[0032] In step A1, the mass ratio of diethylenetriamine, acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol is 1:0.8:0.6:0.6:3; In step A2, the mass ratio of the amino-terminated acrylic emulsion, benzotriazole-isocyanate, and the catalyst dibutyltin dilaurate is 1:0.3:0.03; the solvent is tetrahydrofuran; In step B1, the mass ratio of benzotriazole, tert-butyldimethylchlorosilane, and imidazole is 1:1.3:1.5; In step B2, the mass ratio of tert-butyldimethylchlorosilane-benzotriazole, n-butyllithium, and ethylene oxide is 1:0.3:0.5; In step B3, the mass ratio of 2-hydroxyethyl tert-butyldimethylchlorosilane-benzotriazole, diphenylmethane diisocyanate, and dibutyltin dilaurate is 1:1.2:0.05; In step B4, the mass ratio of tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole is 1.5:1.

[0033] A preparation method of a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film includes the following steps: Mix the surface treatment agent with the nanomaterial, stir at 100 °C for 3 h, cool to room temperature and then add it to the modified acrylic emulsion, stir evenly, then sequentially add the photoinitiator, antioxidant, and crosslinking agent, stir for 60 min, coat it on the substrate, and cure it by ultraviolet irradiation for 3 min to obtain the long-life and aging-resistant acrylic pressure-sensitive adhesive protective film.

[0034] The preparation method of the modified acrylic emulsion includes the following steps: A1. Place diethylenetriamine in a three-necked flask, cool it in an ice-water bath, pass nitrogen, slowly add acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, and methanol, react at 30 °C, transfer it to the eggplant-shaped flask of a rotary evaporator, remove methanol under reduced pressure, and raise the temperature to 160 °C for reduced-pressure reaction for 8 h to obtain the amino-terminated acrylic emulsion; A2. Add the amino-terminated acrylic emulsion to the solvent, stir evenly, slowly add benzotriazole-isocyanate and the catalyst dibutyltin dilaurate under stirring, react at 70 °C for 8 h, cool to room temperature after the reaction, and remove the solvent by distillation under reduced pressure to obtain the modified acrylic emulsion.

[0035] The preparation method of benzotriazole - isocyanate comprises the following steps: B1. Dissolve benzotriazole in anhydrous dichloromethane, cool it to 5 °C, slowly add tert - butyldimethylchlorosilane and imidazole, stir evenly, heat up to 30 °C, react for 4 h. After the reaction, add saturated brine for quenching, stir for 10 min, transfer to a separatory funnel, let it stand for layer separation, collect the organic phase and dry it with anhydrous sodium sulfate for 3 h, filter and then distill off the solvent under reduced pressure to obtain tert - butyldimethylchlorosilane - benzotriazole; B2. Add tert - butyldimethylchlorosilane - benzotriazole to anhydrous tetrahydrofuran, stir to dissolve, at a low temperature of - 80 °C, slowly add n - butyllithium, stir and react for 2 h, then slowly add ethylene oxide, gradually heat up to 5 °C, stir and react for 4 h, slowly add 10% dilute sulfuric acid, adjust the pH to 3, stir at 30 °C for 2 h, extract with dichloromethane, combine the organic phases, wash with saturated sodium bicarbonate solution to remove the residual acid, then wash with saturated brine, dry with anhydrous sodium sulfate, and distill off the solvent under reduced pressure to obtain tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl; B3. Add tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate to anhydrous toluene, place it in an 80 °C water bath, stir and react for 8 h, distill off the solvent under reduced pressure to obtain a carbamate intermediate containing benzotriazole; B4. Add tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole to tetrahydrofuran, stir and react at 30 °C for 4 h. After the reaction, add saturated brine for quenching, extract with dichloromethane, wash with saturated brine, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain benzotriazole - isocyanate.

[0036] Comparative Example 1: The acrylic emulsion is not modified, and the rest of the process is the same as in Example 1.

[0037] Comparative Example 2: The nanomaterials treated without adding a surface treatment agent are not added, and the rest of the process is the same as in Example 1.

[0038] Comparative Example 3: The acrylic emulsion is only modified with terminal amino groups, and the rest of the process is the same as in Example 1.

[0039] Comparative Example 4: The acrylic emulsion is not modified, and the nanomaterials treated without adding a surface treatment agent are not added, and the rest of the process is the same as in Example 1.

[0040] Performance test: Aging resistance test: The pressure-sensitive adhesive protective films prepared in Examples 1 to 3 and Comparative Example 1 were coated on PET materials. The aging test method after 24 h of treatment at 65 °C and 95% RH and 12 h of ultraviolet irradiation was as follows: The test standard referred to the 180° peel strength test of pressure-sensitive tapes in GB / T 2792-2014. The results are shown in Table 1.

[0041]

[0042] As can be seen from Table 1, the difference in peel strength before and after aging treatment in Examples 1 to 3 is small. The difference in peel strength before and after aging in Comparative Example 1 and Comparative Example 3 is large. The difference in Comparative Example 2 is small before and after, but the peel strength of Comparative Example 2 is lower than that of Comparative Example 1 and 3. The peel strength of Comparative Example 3 is higher than that of Comparative Example 1, indicating that Examples 1 to 3 have better aging resistance than Comparative Example 1. The modification of acrylic emulsion can effectively improve the aging resistance of the pressure-sensitive adhesive protective film. Adding nano-materials can effectively improve the strength of the protective film. The modification of the terminal amino group of acrylic emulsion also improves the strength of the protective film to a certain extent.

[0043] High temperature resistance test: The pressure-sensitive adhesive protective films prepared in Examples 1 to 3 and Comparative Example 2 were coated on stainless steel plates, rolled back and forth with a pressure roller for 3 min, placed in an environment of 280 °C for 12 h, cooled to room temperature, and the pressure-sensitive adhesive protective film was peeled off. Observe whether there is any residue on the stainless steel plate. The results are shown in Table 2.

[0044]

[0045] As can be seen from Table 2, the pressure-sensitive adhesive protective films in Examples 1 to 3 can be peeled off completely without residue after high temperature treatment. There is no residue in Comparative Example 1, a small amount of residue in Comparative Example 2, and more residue in Comparative Example 3, indicating that adding modified nano-materials and modifying acrylic emulsion can effectively improve the high temperature resistance of the pressure-sensitive adhesive protective film.

[0046] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film, characterized in that, It consists of the following raw materials in parts by weight: 50 - 70 parts of modified acrylic emulsion, 5 - 8 parts of nanomaterial, 0.1 - 0.3 part of surface treatment agent, 1 - 3 parts of photoinitiator, 0.5 - 1 part of antioxidant, 0.2 - 0.5 part of crosslinking agent; The preparation method of the modified acrylic emulsion includes the following steps: A1. Place diethylenetriamine in a three - necked flask, cool it in an ice - water bath, pass nitrogen, slowly add acrylic acid, methyl acrylate, 2 - hydroxyethyl acrylate, and methanol, react at 20 - 30 °C, transfer it to the egg - shaped flask of a rotary evaporator, remove methanol under reduced pressure, raise the temperature to 120 - 160 °C and react under reduced pressure for 2 - 8 h to obtain an amino - terminated acrylic emulsion; A2. Add the amino - terminated acrylic emulsion to a solvent, stir evenly, slowly add benzotriazole - isocyanate and the catalyst dibutyltin dilaurate under stirring, react at 50 - 70 °C for 2 - 8 h, cool to room temperature after the reaction, remove the solvent by vacuum distillation to obtain a modified acrylic emulsion.

2. The long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 1, wherein In step A1, the mass ratio of diethylenetriamine, acrylic acid, methyl acrylate, 2 - hydroxyethyl acrylate, and methanol is 1:0.6 - 0.8:0.4 - 0.6:0.4 - 0.6:1.5 - 3; In step A2, the mass ratio of the amino - terminated acrylic emulsion, benzotriazole - isocyanate, and the catalyst dibutyltin dilaurate is 1:0.1 - 0.3:0.01 - 0.03; the solvent is one of toluene, N,N - dimethylformamide, and tetrahydrofuran.

3. The long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 2, characterized in that The preparation method of benzotriazole - isocyanate includes the following steps: B1. Dissolve benzotriazole in anhydrous dichloromethane, cool it to 0 - 5 °C, slowly add tert - butyldimethylchlorosilane and imidazole, stir evenly, raise the temperature to 20 - 30 °C, react for 2 - 4 h, add saturated brine for quenching after the reaction, stir for 5 - 10 min, transfer to a separatory funnel, let it stand for layering, collect the organic phase and dry it with anhydrous sodium sulfate for 2 - 3 h, filter and remove the solvent by vacuum distillation to obtain tert - butyldimethylchlorosilane - benzotriazole; B2. Add tert - butyldimethylchlorosilane - benzotriazole to anhydrous tetrahydrofuran, stir to dissolve, at a low temperature of - 60 - 80 °C, slowly add n - butyllithium, stir and react for 1 - 2 h, then slowly add ethylene oxide, gradually raise the temperature to 0 - 5 °C, stir and react for 2 - 4 h, slowly add 10% dilute sulfuric acid to adjust the pH to 2 - 3, stir at 20 - 30 °C for 1 - 2 h, extract with dichloromethane, combine the organic phases, wash with saturated sodium bicarbonate solution to remove the residual acid, then wash with saturated brine, dry with anhydrous sodium sulfate, and remove the solvent by vacuum distillation to obtain tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl; B3. Add tert - butyldimethylchlorosilane - benzotriazole containing hydroxyethyl, diphenylmethane diisocyanate, and dibutyltin dilaurate to anhydrous toluene, place it in a water bath at 60 - 80 °C, stir and react for 4 - 8 h, remove the solvent by vacuum distillation to obtain a carbamate intermediate containing benzotriazole; B4. Add tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole into tetrahydrofuran, stir and react at 20 - 30 °C for 2 - 4 h. After the reaction is completed, add saturated brine for quenching, extract with dichloromethane, wash with saturated brine, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain benzotriazole - isocyanate.

4. A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 3, characterized in that, In step B1, the mass ratio of benzotriazole, tert - butyldimethylchlorosilane, and imidazole is 1:1 - 1.3:1.2 - 1.5; In step B2, the mass ratio of tert - butyldimethylchlorosilane - benzotriazole, n - butyllithium, and ethylene oxide is 1:0.1 - 0.3:0.3 - 0.5; In step B3, the mass ratio of hydroxyethyl tert - butyldimethylchlorosilane - benzotriazole, diphenylmethane diisocyanate, and dibutyltin dilaurate is 1:0.8 - 1.2:0.01 - 0.05; In step B4, the mass ratio of tetrabutylammonium fluoride and the carbamate intermediate containing benzotriazole is 1.2 - 1.5:

1.

5. A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 1, wherein, The photoinitiator is one of 184, 1173, or benzophenone.

6. The long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 1, wherein The antioxidant is one of 1010, 168, or DLTP.

7. A long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to claim 1, characterized in that The cross - linker is one of trimethylolpropane triacrylate, pentaerythritol triacrylate, or hexamethylene diisocyanate.

8. The preparation method of a long-life and aging-resistant acrylic pressure-sensitive adhesive protective film according to any one of claims 1 to 7, characterized in that, It includes the following steps: Mix the surface treatment agent with the nanomaterial, stir at 80 - 100 °C for 2 - 3 h, cool to room temperature and then add it to the modified acrylic emulsion, stir evenly, then successively add the photoinitiator, antioxidant, and cross - linker, stir for 30 - 60 min, coat on the substrate, and cure by ultraviolet irradiation for 1 - 3 min to obtain a long - life and aging - resistant acrylic pressure - sensitive adhesive protective film; The surface treatment agent is one of γ - aminopropyltriethoxysilane, γ - glycidyletheroxypropyltrimethoxysilane, or γ - methacryloxypropyltrimethoxysilane; The nanomaterial is one of nano - aluminum hydroxide, nano - magnesium hydroxide, or nano - montmorillonite.

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