Anti-aging PE-based pressure-sensitive adhesive protective film and preparation method thereof

Abstract

The invention discloses an anti-aging PE-based pressure-sensitive adhesive protective film and a preparation method thereof.The anti-aging PE-based pressure-sensitive adhesive protective film is prepared by coating one side of a PE base film with an acrylate pressure-sensitive adhesive and drying the acrylate pressure-sensitive adhesive, a PE base film molecular chain on the surface of the anti-aging PE-based pressure-sensitive adhesive protective film contains a fluorine-containing polysiloxane structure, fluorine atoms can form a protective layer on the surface, and therefore the anti-aging PE-based pressure-sensitive adhesive protective film has good anti-aging performance. The bond energy of a C-F bond is higher than the photon energy in ultraviolet rays, so that the ultraviolet rays cannot break the C-F bond, the ultraviolet ray resistant effect of the PE base film is further improved, the interpenetration of a polysiloxane chain segment can improve the thermo-oxidative aging resistant effect of the PE base film, and the polysiloxane chain segment is matched with an internal hindered phenol structure, so that the aging resistant effect of the PE base film is further improved, and the service life of the PE base film is prolonged. Meanwhile, due to the addition of the modified filler, an inorganic protective layer can be formed in the PE base film, so that ultraviolet light is prevented from entering the material, the acrylate pressure-sensitive adhesive cannot be interfered by the ultraviolet light, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of pressure-sensitive adhesive protective film preparation, and particularly relates to an anti-aging PE-based pressure-sensitive adhesive protective film and a preparation method thereof. BACKGROUND

[0002] With the wide application of modern industry and electronic products, the demand for protective films of various materials is increasing. Among them, the pressure-sensitive adhesive protective film is widely used in the electronic product, manufacturing industry and packaging industry due to its good adhesion and flexibility. Especially on products such as touch screens, mobile phone screens and computer screens, the pressure-sensitive adhesive protective film not only can protect the surface from physical damage such as scratching, but also can play a role in preventing static electricity. However, the existing protective film still has certain deficiencies in weather resistance, moisture resistance and peel strength, and cannot fully meet the market demand for high-performance protective films. SUMMARY

[0003] The application aims to provide an anti-aging PE-based pressure-sensitive adhesive protective film and a preparation method thereof, and solves the problem of obvious aging of the PE-based film on the surface of the PE-based pressure-sensitive adhesive protective film after long-term use at the present stage.

[0004] The purpose of the application can be achieved by the following technical solutions. A preparation method of an anti-aging PE-based pressure-sensitive adhesive protective film, specifically comprising the following steps: Step A1: nano-silicon dioxide is placed in a muffle furnace, dried at a temperature of 110-120 DEG C for 2-4 h, then dispersed in anhydrous ethanol, stirred at a speed of 600-800 r / min and a temperature of 25-30 DEG C, 3-glycidyl ether oxypropyl trimethoxysilane and deionized water are added, the temperature is raised to 70-80 DEG C, the pH value is adjusted to 4-5, and the reaction is carried out for 6-8 h to obtain a modified filler; Step A2: PE master batch, dicumyl peroxide, 4-maleimide benzoic acid and modified additive are added to a banbury mixer, reacted at a speed of 60-80 r / min and a temperature of 185-190 DEG C for 30-40 min, then the modified filler and triethylamine are added, and the reaction is continued for 1-1.5 h to obtain a melt, the melt is introduced, blown, stretched, corona treated, edge cut and wound to obtain a PE-based film; Step A3: the following raw materials are weighed: butyl acrylate 10-15 parts, isooctyl acrylate 10-15 parts, ethyl acrylate 2-4 parts, acrylic acid 3-6 parts, hydroxyethyl acrylate 3-6 parts, azobis isobutyronitrile 0.1-0.3 parts and ethyl acetate 50-60 parts, the raw materials are mixed and reacted to obtain an acrylate pressure-sensitive adhesive, the acrylate pressure-sensitive adhesive is coated on one side of the PE-based film and dried to obtain an anti-aging PE-based pressure-sensitive adhesive protective film.

[0005] Furthermore, the amount of 3-glycidyl etheroxypropyltrimethoxysilane used in step A1 is 3% of the mass of nano-silica.

[0006] Furthermore, the PE masterbatch mentioned in step A2 is of type 2426H, and the weight ratio of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid, modified additives, modified fillers and triethylamine is 100-120:1-1.5:10-15:30-40:20-25:0.5-1.

[0007] Furthermore, the modified additive is prepared by the following steps: Step B1: Mix p-nitrostyrene, dichlorosilane, chloroplatinic acid and toluene, purge with nitrogen, and react for 20-25 hours at a speed of 200-300 r / min and a temperature of 110-115℃ to obtain a modifier. Mix lithium dimethylsilyl alcohol and tetrahydrofuran evenly, purge with nitrogen, and stir at a speed of 120-150 r / min and a temperature of 0℃. Add trifluoropropylmethylcyclotrisiloxane, heat to 20-25℃, and react for 6-8 hours. Add the modifier and continue the reaction for 1-1.5 hours to obtain a pretreated polysiloxane. Step B2: Mix the pretreated polysiloxane, palladium on carbon catalyst, and DMF evenly, introduce hydrogen gas, and react for 4-6 hours at a rotation speed of 300-500 r / min, a temperature of 75-80℃, and a pressure of 1-2 MPa to obtain an amino-modified polysiloxane. Mix 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine, and dichloromethane evenly, introduce nitrogen gas for protection, and stir and add N,N'-dicyclohexylcarbodiimide at a rotation speed of 200-300 r / min and a temperature of 0℃. Stir for 30-40 minutes, raise the temperature to 20-25℃, and continue the reaction for 12-15 hours to obtain an intermediate. Step B3: Mix the intermediate, aminated polysiloxane, chloroplatinic acid, and o-xylene evenly, purge with nitrogen, and react for 8-10 hours at a speed of 150-200 r / min and a temperature of 80-85℃ to obtain modified polysiloxane. Mix the modified polysiloxane, p-aldehyde benzoic acid, 4A molecular sieve, and tetrahydrofuran evenly, and react for 2-3 hours at a speed of 200-300 r / min and a temperature of 68-70℃ to obtain modified additive.

[0008] Furthermore, in step B1, the molar ratio of p-nitrostyrene to dichlorosilane is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of dichlorosilane, and the molar ratio of lithium dimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and modifier is 6.4:12.8:2.35.

[0009] Furthermore, the amount of palladium catalyst on carbon mentioned in step B2 is 5% of the mass of the pretreated polysiloxane, and the molar ratio of 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 1:2.2:0.2:2.4.

[0010] Furthermore, the molar ratio of the intermediate and the aminated polysiloxane in step B3 is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of the intermediate, and the ratio of the amount of modified polysiloxane, p-aldehyde benzoic acid and 4A molecular sieve is 1 mmol:2 mmol:2 g.

[0011] The beneficial effects of the present invention are as follows: The aging-resistant PE-based pressure-sensitive adhesive protective film prepared by the present invention is obtained by coating one side of a PE base film with an acrylate pressure-sensitive adhesive and drying it. The acrylate pressure-sensitive adhesive includes the following raw materials: butyl acrylate, isooctyl acrylate, ethyl acrylate, acrylic acid, hydroxyethyl acrylate, azobisisobutyronitrile and ethyl acetate. The PE base film is prepared by melt mixing and reaction of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid and modified additives, followed by film drawing, blowing, stretching, corona treatment, edge trimming and winding.

[0012] The modified filler was prepared by treating nano-silica with 3-glycidyl etheroxypropyltrimethoxysilane to graft epoxy groups onto the surface.

[0013] The modifier uses p-nitrostyrene and dichlorosilane as raw materials, reacting the double bonds on p-nitrostyrene with the Si-H bonds on dichlorosilane to obtain a modifier. Using lithium dimethylsilanolate as an initiator and trifluoropropylmethyltrisiloxane as a monomer, a fluorinated polysiloxane with one Si-H bond and the other lithium silanolate is prepared. The modifier is then added, causing the Si-Cl bonds on the modifier to react with the lithium silanolate, yielding a pretreated polysiloxane. The pretreated polysiloxane is then reduced using a palladium-on-carbon catalyst under a hydrogen atmosphere, converting the nitro groups on the pretreated polysiloxane to amino groups, and then reducing the 2-butane group... The intermediate is prepared by reacting 1,4-diol and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid to esterify the hydroxyl group on 1,4-diol and the carboxyl group on β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid. The intermediate is then reacted with an amino-modified polysiloxane to react the double bond on the intermediate with the Si-H bond on the amino-modified polysiloxane to prepare a modified polysiloxane. The modified polysiloxane is then reacted with p-aldehyde benzoic acid to react the amino group on the modified polysiloxane with the aldehyde group on the p-aldehyde benzoic acid to prepare a modified additive.

[0014] The PE-based pressure-sensitive adhesive protective film has a fluorinated polysiloxane structure in its molecular chain. Fluorine atoms can form a protective layer on the surface, and the bond energy of the CF bond is higher than that of photons in ultraviolet light, preventing ultraviolet light from breaking the CF bond, thus increasing the UV resistance of the PE-based film. The interpenetration of polysiloxane segments can enhance the heat and oxygen aging resistance of the PE-based film. Combined with the hindered phenolic structure inside, the aging resistance of the PE-based film is further improved. At the same time, the addition of modified fillers can form an inorganic protective layer inside the PE-based film, which can prevent ultraviolet light from entering the material, making the acrylic pressure-sensitive adhesive immune to ultraviolet interference, thereby increasing its service life. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1: A method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film, specifically including the following steps: Step A1: Place nano-silica in a muffle furnace and dry it at 110℃ for 2 hours. Then disperse it in anhydrous ethanol. Stir and add 3-glycidyl etheroxypropyltrimethoxysilane and deionized water at 25℃ and 600 r / min. Heat to 70℃, adjust the pH to 4, and react for 6 hours to obtain the modified filler. Step A2: Add PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid and modified additives to a mixer and react for 30 minutes at a speed of 60 r / min and a temperature of 185℃. Then add modified filler and triethylamine and continue the reaction for 1 hour to obtain a melt. The melt is then processed through film drawing, blowing, stretching, corona treatment, edge trimming and winding to obtain a PE base film. Step A3: Weigh the following raw materials in parts by weight: 10 parts butyl acrylate, 10 parts isooctyl acrylate, 2 parts ethyl acrylate, 3 parts acrylic acid, 3 parts hydroxyethyl acrylate, 0.1 parts azobisisobutyronitrile, and 50 parts ethyl acetate. Mix the raw materials and react them to obtain an acrylic pressure-sensitive adhesive. Coat the acrylic pressure-sensitive adhesive on one side of a PE base film and dry it to obtain an aging-resistant PE base pressure-sensitive adhesive protective film.

[0017] The amount of 3-glycidyl etheroxypropyltrimethoxysilane used in step A1 is 3% of the mass of nano-silica.

[0018] The PE masterbatch mentioned in step A2 is of type 2426H, and the weight ratio of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid, modified additives, modified fillers and triethylamine is 100:1:10:30:20:0.5.

[0019] The modified additive is prepared by the following steps: Step B1: Mix p-nitrostyrene, dichlorosilane, chloroplatinic acid and toluene, purge with nitrogen, and react for 20 h at 200 r / min and 110 °C to obtain a modifier. Mix lithium dimethylsiloxane and tetrahydrofuran evenly, purge with nitrogen, stir and add trifluoropropylmethylcyclotrisiloxane at 120 r / min and 0 °C, heat to 20 °C and react for 6 h, then add the modifier and continue reacting for 1 h to obtain a pretreated polysiloxane. Step B2: The pretreated polysiloxane, palladium on carbon catalyst and DMF were mixed evenly, and hydrogen was introduced. The mixture was reacted for 4 hours at a speed of 300 r / min, a temperature of 75 °C and a pressure of 1 MPa to obtain the amino-modified polysiloxane. 2-Buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and dichloromethane were mixed evenly, and nitrogen was introduced for protection. The mixture was stirred and N,N'-dicyclohexylcarbodiimide was added at a speed of 200 r / min and a temperature of 0 °C. The mixture was stirred for 30 min, heated to 20 °C and reacted for another 12 h to obtain the intermediate. Step B3: Mix the intermediate, aminated polysiloxane, chloroplatinic acid and o-xylene evenly, purge with nitrogen, and react for 8 hours at 150 r / min and 80 °C to obtain modified polysiloxane. Mix the modified polysiloxane, p-aldehyde benzoic acid, 4A molecular sieve and tetrahydrofuran evenly, and react for 2 hours at 200 r / min and 68 °C to obtain modified additive.

[0020] In step B1, the molar ratio of p-nitrostyrene and dichlorosilane is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of dichlorosilane, and the molar ratio of lithium dimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and modifier is 6.4:12.8:2.35.

[0021] The amount of palladium catalyst on carbon mentioned in step B2 is 5% of the mass of the pretreated polysiloxane, and the molar ratio of 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 1:2.2:0.2:2.4.

[0022] The molar ratio of the intermediate and the aminated polysiloxane in step B3 is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of the intermediate, and the ratio of the amount of modified polysiloxane, p-aldehyde benzoic acid and 4A molecular sieve is 1 mmol:2 mmol:2 g.

[0023] Example 2, a method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film, specifically includes the following steps: Step A1: Place nano-silica in a muffle furnace and dry it at 115℃ for 3 hours. Then disperse it in anhydrous ethanol. Stir and add 3-glycidyl etheroxypropyltrimethoxysilane and deionized water at 28℃ and 800 r / min. Heat to 75℃, adjust the pH to 4, and react for 7 hours to obtain the modified filler. Step A2: Add PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid and modified additives to a mixer and react for 35 minutes at a speed of 60 r / min and a temperature of 190℃. Then add modified filler and triethylamine and continue the reaction for 1.3 hours to obtain a melt. Pass the melt through film drawing, blowing, stretching, corona treatment, edge trimming and winding to obtain a PE base film. Step A3: Weigh the following raw materials in parts by weight: 13 parts butyl acrylate, 13 parts isooctyl acrylate, 3 parts ethyl acrylate, 4.5 parts acrylic acid, 4.5 parts hydroxyethyl acrylate, 0.2 parts azobisisobutyronitrile, and 55 parts ethyl acetate. Mix the raw materials and react them to obtain an acrylic pressure-sensitive adhesive. Coat the acrylic pressure-sensitive adhesive on one side of a PE base film and dry it to obtain an aging-resistant PE base pressure-sensitive adhesive protective film.

[0024] The amount of 3-glycidyl etheroxypropyltrimethoxysilane used in step A1 is 3% of the mass of nano-silica.

[0025] The PE masterbatch mentioned in step A2 is of type 2426H, and the weight ratio of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid, modified additives, modified fillers and triethylamine is 110:1.3:13:35:23:0.8.

[0026] The modified additive is prepared by the following steps: Step B1: Mix p-nitrostyrene, dichlorosilane, chloroplatinic acid and toluene, purge with nitrogen, and react for 20 h at 200 r / min and 115 °C to obtain a modifier. Mix lithium dimethylsiloxane and tetrahydrofuran evenly, purge with nitrogen, stir and add trifluoropropylmethylcyclotrisiloxane at 150 r / min and 0 °C, raise the temperature to 20 °C and react for 7 h. Then add the modifier and continue the reaction for 1.3 h to obtain a pretreated polysiloxane. Step B2: The pretreated polysiloxane, palladium on carbon catalyst and DMF were mixed evenly, and hydrogen was introduced. The mixture was reacted for 5 h at a speed of 500 r / min, a temperature of 75 °C and a pressure of 1 MPa to obtain an amino-modified polysiloxane. 2-Buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and dichloromethane were mixed evenly, and nitrogen was introduced for protection. The mixture was stirred and N,N'-dicyclohexylcarbodiimide was added at a speed of 300 r / min and a temperature of 0 °C. The mixture was stirred for 35 min, heated to 20 °C and reacted for another 15 h to obtain an intermediate. Step B3: Mix the intermediate, aminated polysiloxane, chloroplatinic acid and o-xylene evenly, purge with nitrogen, and react for 9 hours at 150 r / min and 85°C to obtain modified polysiloxane. Mix the modified polysiloxane, p-aldehyde benzoic acid, 4A molecular sieve and tetrahydrofuran evenly, and react for 2 hours at 200 r / min and 70°C to obtain modified additive.

[0027] In step B1, the molar ratio of p-nitrostyrene and dichlorosilane is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of dichlorosilane, and the molar ratio of lithium dimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and modifier is 6.4:12.8:2.35.

[0028] The amount of palladium catalyst on carbon mentioned in step B2 is 5% of the mass of the pretreated polysiloxane, and the molar ratio of 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 1:2.2:0.2:2.4.

[0029] The molar ratio of the intermediate and the aminated polysiloxane in step B3 is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of the intermediate, and the ratio of the amount of modified polysiloxane, p-aldehyde benzoic acid and 4A molecular sieve is 1 mmol:2 mmol:2 g.

[0030] Example 3: A method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film, specifically including the following steps: Step A1: Place nano-silica in a muffle furnace and dry it at 120℃ for 4 hours. Then disperse it in anhydrous ethanol. Stir and add 3-glycidyl etheroxypropyltrimethoxysilane and deionized water at 30℃ and 800 r / min. Heat the mixture to 80℃, adjust the pH to 5, and react for 8 hours to obtain the modified filler. Step A2: Add PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid and modified additives to a mixer and react for 40 minutes at a speed of 80 r / min and a temperature of 190℃. Then add modified filler and triethylamine and continue the reaction for 1.5 hours to obtain a melt. Pass the melt through film drawing, blowing, stretching, corona treatment, edge trimming and winding to obtain a PE base film. Step A3: Weigh the following raw materials in parts by weight: 15 parts butyl acrylate, 15 parts isooctyl acrylate, 4 parts ethyl acrylate, 6 parts acrylic acid, 6 parts hydroxyethyl acrylate, 0.3 parts azobisisobutyronitrile, and 60 parts ethyl acetate. Mix the raw materials and react them to obtain an acrylic pressure-sensitive adhesive. Coat the acrylic pressure-sensitive adhesive on one side of a PE base film and dry it to obtain an aging-resistant PE base pressure-sensitive adhesive protective film.

[0031] The amount of 3-glycidyl etheroxypropyltrimethoxysilane used in step A1 is 3% of the mass of nano-silica.

[0032] The PE masterbatch mentioned in step A2 is of type 2426H, and the weight ratio of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid, modified additives, modified fillers and triethylamine is 120:1.5:15:40:25:1.

[0033] The modified additive is prepared by the following steps: Step B1: Mix p-nitrostyrene, dichlorosilane, chloroplatinic acid and toluene, purge with nitrogen, and react for 25 h at 300 r / min and 115 °C to obtain a modifier. Mix lithium dimethylsiloxane and tetrahydrofuran evenly, purge with nitrogen, stir and add trifluoropropylmethylcyclotrisiloxane at 150 r / min and 0 °C, raise the temperature to 25 °C and react for 8 h. Then add the modifier and continue the reaction for 1.5 h to obtain a pretreated polysiloxane. Step B2: The pretreated polysiloxane, palladium on carbon catalyst and DMF were mixed evenly, and hydrogen was introduced. The mixture was reacted for 6 hours at a speed of 500 r / min, a temperature of 80 °C and a pressure of 2 MPa to obtain the amino-modified polysiloxane. 2-Buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and dichloromethane were mixed evenly, and nitrogen was introduced for protection. The mixture was stirred and N,N'-dicyclohexylcarbodiimide was added at a speed of 300 r / min and a temperature of 0 °C. The mixture was stirred for 40 min, heated to 25 °C and reacted for another 15 h to obtain the intermediate. Step B3: Mix the intermediate, aminated polysiloxane, chloroplatinic acid and o-xylene evenly, purge with nitrogen, and react for 10 h at 200 r / min and 85 °C to obtain modified polysiloxane. Mix the modified polysiloxane, p-aldehyde benzoic acid, 4A molecular sieve and tetrahydrofuran evenly, and react for 3 h at 300 r / min and 70 °C to obtain modified additive.

[0034] In step B1, the molar ratio of p-nitrostyrene and dichlorosilane is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of dichlorosilane, and the molar ratio of lithium dimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and modifier is 6.4:12.8:2.35.

[0035] The amount of palladium catalyst on carbon mentioned in step B2 is 5% of the mass of the pretreated polysiloxane, and the molar ratio of 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 1:2.2:0.2:2.4.

[0036] The molar ratio of the intermediate and the aminated polysiloxane in step B3 is 2:1, the amount of chloroplatinic acid is 0.01% of the mass of the intermediate, and the ratio of the amount of modified polysiloxane, p-aldehyde benzoic acid and 4A molecular sieve is 1 mmol:2 mmol:2 g.

[0037] Comparative Example 1: This comparative example uses nano-silica instead of the modified filler, but the other steps are the same as in Example 1.

[0038] Comparative Example 2: This comparative example uses amino-modified polysiloxane instead of modified polysiloxane, while the remaining steps are the same as in Example 1.

[0039] Comparative Example 3 is the same as Example 1, except that hexamethylcyclotrisiloxane is used instead of trifluoropropylmethylcyclotrisiloxane.

[0040] The PE base films prepared in Examples 1-3 and Comparative Examples 1-3 were made into Type 4 samples according to the standard GB / T1040.3-2006. The tensile speed was 50 mm / min. After testing the tensile strength, the samples were irradiated for 2000 h according to the standard ISO 4892-2. The tensile strength retention rate after photoaging was tested. The samples were treated for 400 h at a temperature of 85℃ and a humidity of 85%. The tensile strength retention rate after damp heat aging was tested. The test results are shown in Table 1 below.

[0041] Table 1

[0042] As shown in Table 1, this application has excellent aging resistance.

[0043] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film, characterized in that: Specifically, the steps include the following: Step A1: Place nano-silica in a muffle furnace, keep it warm and dry, disperse it in anhydrous ethanol, stir and add 3-glycidyl etheroxypropyltrimethoxysilane and deionized water, heat and react to obtain the modified filler. Step A2: Add PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid and modified additives to a mixer and react. Then add modified filler and triethylamine and continue the reaction to obtain a melt. Pass the melt through film drawing, blowing, stretching, corona treatment, edge trimming and winding to obtain a PE base film. Step A3: Weigh the following raw materials in parts by weight: 10-15 parts butyl acrylate, 10-15 parts isooctyl acrylate, 2-4 parts ethyl acrylate, 3-6 parts acrylic acid, 3-6 parts hydroxyethyl acrylate, 0.1-0.3 parts azobisisobutyronitrile, and 50-60 parts ethyl acetate. Mix the raw materials and react them to obtain an acrylic pressure-sensitive adhesive. Coat the acrylic pressure-sensitive adhesive on one side of a PE base film and dry it to obtain an aging-resistant PE base pressure-sensitive adhesive protective film.

2. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 1, characterized in that: The amount of 3-glycidyl etheroxypropyltrimethoxysilane used in step A1 is 3% of the mass of nano-silica.

3. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 1, characterized in that: The weight ratio of PE masterbatch, dicumyl peroxide, 4-maleimide benzoic acid, modified additives, modified fillers and triethylamine mentioned in step A2 is 100-120:1-1.5:10-15:30-40:20-25:0.5-1.

4. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 1, characterized in that: The modified additive is prepared by the following steps: Step B1: Mix p-nitrostyrene, dichlorosilane, chloroplatinic acid and toluene, purge with nitrogen, and react to obtain a modifier. Mix lithium dimethylsilyl alcohol and tetrahydrofuran evenly, purge with nitrogen, stir and add trifluoropropylmethylcyclotrisiloxane. After heating and reacting, add the modifier and continue the reaction to obtain pretreated polysiloxane. Step B2: The pretreated polysiloxane, palladium on carbon catalyst and DMF are mixed evenly, hydrogen is introduced and the reaction is carried out to obtain amino-modified polysiloxane. 2-Buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and dichloromethane are mixed evenly, nitrogen is introduced for protection, N,N'-dicyclohexylcarbodiimide is added and the reaction is carried out to obtain intermediate. Step B3: Mix the intermediate, aminated polysiloxane, chloroplatinic acid and o-xylene evenly, purge with nitrogen for protection, and react to obtain modified polysiloxane. Mix the modified polysiloxane, p-aldehyde benzoic acid, 4A molecular sieve and tetrahydrofuran to obtain modified additive.

5. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 4, characterized in that: The molar ratio of p-nitrostyrene and dichlorosilane in step B1 is 2:1, and the molar ratio of lithium dimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and modifier is 6.4:12.8:2.

35.

6. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 4, characterized in that: The amount of palladium catalyst on carbon mentioned in step B2 is 5% of the mass of the pretreated polysiloxane, and the molar ratio of 2-buten-1,4-diol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 1:2.2:0.2:2.

4.

7. The method for preparing an aging-resistant PE-based pressure-sensitive adhesive protective film according to claim 4, characterized in that: The molar ratio of the intermediate and the aminated polysiloxane mentioned in step B3 is 2:1, and the ratio of the modified polysiloxane, p-aldehyde benzoic acid and 4A molecular sieve is 1 mmol:2 mmol:2 g.

8. An aging-resistant PE-based pressure-sensitive adhesive protective film, characterized in that: Prepared according to any one of the preparation methods described in claims 1-7.

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