A protective film for mobile phone screen and preparation method thereof

Abstract

The present invention belongs to the field of adhesive technology, and specifically relates to a protective film for mobile phone screens and a preparation method thereof. The mobile phone screen protective film of the present invention includes an AB adhesive film, which includes a first adhesive layer, a PET film layer, and a second adhesive layer arranged in sequence; the first adhesive layer includes the following raw materials in parts by weight: 40-50 parts of silicone resin, 1-5 parts of modified cellulose nano whiskers, 0.1-0.5 parts of coupling agent, 0.1-0.3 parts of blue light absorber, and 0.05-0.1 parts of catalyst; the second adhesive layer includes the following raw materials in parts by weight: 50-60 parts of acrylate polymer resin, 1-5 parts of tackifier, and 0.05-0.1 parts of curing agent; the first adhesive layer of the present invention has low adhesion, and the introduced modified cellulose nano whiskers can increase the cohesive strength of the first adhesive layer, reduce the pores and cracks in the adhesive layer, and extend the service life of the AB adhesive film. The second adhesive layer has high adhesion properties, and the introduced tackifier improves its bonding strength.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and in particular relates to a protective film for a mobile phone screen and a preparation method thereof. Background Art

[0002] With the rapid development of smartphone technology, the need for protection of mobile phone screens, as the core interface for human-computer interaction, has become increasingly prominent. As one of the most fragile and expensive components of a mobile phone, the screen is extremely susceptible to damage such as scratches, impacts, and cracks during daily use. This not only affects the user experience but can also lead to high repair costs. Currently, there are a wide variety of mobile phone screen protectors on the market, including plastic films, electrostatic adsorption films, and ordinary tempered glass films. However, these traditional protective films have many performance limitations. While ordinary tempered glass films are relatively hard and can effectively resist scratches and certain impacts, they are prone to problems such as bubbles and white edges during the bonding process. Furthermore, the curvature of the screen edges is not ideally processed, resulting in a loose bond and significantly reduced protective effectiveness.

[0003] At present, most traditional adhesive films on the market use a single-component adhesive system, which still has shortcomings in performance. The prior art discloses a single-component acrylic pressure-sensitive adhesive, which has insufficient cohesive strength and is prone to failure after repeated pasting. In recent years, AB adhesive film has gradually attracted market attention as a new type of mobile phone screen protective film material. AB adhesive film is usually composed of a first adhesive layer, a PET film and a second adhesive layer, wherein the PET film serves as a base material with good flexibility and transparency; the first adhesive layer and the second adhesive layer are responsible for bonding to the mobile phone screen and tempered glass, respectively. However, the adhesive layer of some AB adhesive films is of poor quality and is prone to warping, falling off, etc. On the other hand, when the glass film is thicker and harder, degassing is more difficult, and higher requirements are placed on the bonding reliability of the adhesive layer. Summary of the Invention

[0004] The first objective of the present invention is to provide a protective film for mobile phone screens. The first adhesive layer of the present invention has low adhesion and faces the tempered glass. The modified cellulose nanowhiskers introduced into the first adhesive layer enhance the cohesive strength of the adhesive, reduce defects such as pores and cracks in the first adhesive layer, and extend the service life of the AB adhesive film. The second adhesive layer has high adhesion and faces the screen. The tackifier introduced into the second adhesive layer improves the bonding strength.

[0005] The second object of the present invention is to provide a method for preparing a protective film for a mobile phone screen.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A protective film for a mobile phone screen, comprising an AB adhesive film; the AB adhesive film comprises a first adhesive layer, a PET film layer, and a second adhesive layer arranged in sequence;

[0008] The first adhesive layer comprises the following raw materials in parts by weight: 40-50 parts of silicone resin, 1-5 parts of modified cellulose nano whiskers, 0.1-0.5 parts of coupling agent, 0.1-0.3 parts of blue light absorber, and 0.05-0.1 parts of catalyst;

[0009] The second adhesive layer comprises the following raw materials in parts by weight: 50-60 parts of acrylate polymer resin, 1-5 parts of tackifier, and 0.05-0.1 parts of curing agent;

[0010] The preparation process of the modified cellulose nano whiskers is as follows:

[0011] S1. Add 2,2,6,6-tetramethylpiperidinyl oxide, sodium bromide and sodium hypochlorite to the cellulose nanowhisker solution, adjust the pH of the solution to alkaline, react at room temperature, dialyze, and freeze-dry to obtain carboxylated cellulose nanowhiskers;

[0012] S2. Take carboxylated cellulose nanowhiskers and add them to water, adjust the pH to 5.5-6.5, then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and spermidine, react at room temperature, dialyze, and freeze-dry to obtain the product.

[0013] Furthermore, the preparation process of the acrylic polymer resin is as follows:

[0014] Ethyl acrylate, methacrylic acid, and azobisisobutyronitrile are weighed respectively in a mass ratio of (90-92): (6-9): (0.5-1); ethyl acrylate and methacrylic acid are uniformly mixed, then heated to 70-80°C, azobisisobutyronitrile is added, and the temperature is raised to 75-85°C, and the reaction is carried out for 3-5 hours to obtain an acrylate polymer resin.

[0015] Furthermore, in step S1, the dosage ratio of the cellulose nano whisker solution, 2,2,6,6-tetramethylpiperidinium oxide, sodium bromide and sodium hypochlorite is 100 mL: 100-150 mg: 300-350 mg: 15-20 mL; the reaction time is 5-7 h; the concentration of the cellulose nano whisker solution is 1-3 wt %; and the alkalinity refers to a pH value of 10-11.5.

[0016] Furthermore, in step S2, the mass ratio of the carboxylated cellulose nanowhiskers, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, spermidine and water is 1:(0.8-1.2):(0.8-1.2):(3-5):(50-80); and the reaction time is 18-24 hours.

[0017] Furthermore, the preparation process of the tackifier is as follows: adding fumed silica to a solvent containing a catalyst, then adding isocyanatepropyltriethoxysilane and hydroxyethyl acrylate, heating and reacting to obtain the tackifier.

[0018] Furthermore, the mass ratio of the fumed silica, catalyst, isocyanatepropyltriethoxysilane, hydroxyethyl acrylate and solvent is 1: (0.1-0.3): (0.3-0.5): (0.3-0.5): (5-10); the catalyst is bismuth neodecanoate; the solvent is toluene; the temperature of the heating reaction is 70-80°C, and the time is 3-5 hours.

[0019] Furthermore, the mobile phone screen protective film further includes a base material layer located on the first adhesive layer of the AB adhesive film and a release film layer located on the second adhesive layer of the AB adhesive film.

[0020] Furthermore, the substrate layer is tempered glass; and the release film layer is PET film.

[0021] When in use, the release film layer is torn off to achieve adhesion to the mobile phone screen.

[0022] Furthermore, the coupling agent is γ-aminopropyltriethoxysilane; the blue light absorber is blue light absorber BL1226; the catalyst is a platinum catalyst; and the curing agent is an isocyanate curing agent.

[0023] Furthermore, the isocyanate curing agent is an HDI curing agent.

[0024] The method for preparing the mobile phone screen protective film comprises the following steps:

[0025] a. Stir the silicone resin, modified cellulose nanowhiskers, coupling agent, blue light absorber, and catalyst to obtain a first adhesive layer;

[0026] b. Then, the acrylate polymer resin, tackifier and curing agent are stirred to obtain a second adhesive layer;

[0027] c. A first adhesive layer is coated on the upper surface of the PET film layer; a second adhesive layer is then coated on the lower surface of the PET film layer and dried to obtain an AB film; wherein the thickness of the first adhesive layer is 70-80µm; the thickness of the second adhesive layer is 38-45µm;

[0028] d. Lay the substrate layer on the first adhesive layer of the AB adhesive film, and the release film layer on the second adhesive layer of the AB adhesive film, and dry at 110℃-120℃.

[0029] Compared with the prior art, the beneficial effects of the present invention are mainly:

[0030] The AB adhesive film in this invention serves as the core adhesive layer of the wear protection film between the glass and the phone screen. The first adhesive layer of this invention has low adhesion and faces the tempered glass. The modified cellulose nanowhiskers introduced into the first adhesive layer enhance the cohesive strength of the adhesive, reducing defects such as porosity and cracks in the first adhesive layer, thereby extending the service life of the AB adhesive film. The second adhesive layer has high adhesion properties and faces the screen. The tackifier introduced into the second adhesive layer improves the bonding strength. A detailed analysis is as follows:

[0031] The modified cellulose nanowhiskers introduced in the present invention can increase the cohesive strength of the adhesive in the first adhesive layer, improve the bonding properties, and have antioxidant properties, thereby extending the service life of the AB film. The modified cellulose nanowhiskers and the adhesive components in the first adhesive layer have good interfacial compatibility, reducing defects such as pores and cracks in the first adhesive layer.

[0032] The tackifier of the present invention grafts carbamate groups onto the surface of fumed silica through covalent bonds, thereby enhancing the chemical bonding with the acrylate polymer resin. The introduced carbamate bonds have good flexibility, improve the interfacial bonding with the acrylate polymer resin, and thus improve the bonding strength of the second adhesive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is an electron microscope image of the modified cellulose nanowhiskers obtained in Example 1 of the present invention;

[0034] Figure 2 This is an electron microscope image of the tackifier obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be further described below in conjunction with specific embodiments. However, it should be understood by those skilled in the art that the following examples are only intended to illustrate the present invention and should not be construed as limiting the present invention. Specific conditions not specified in the examples are to be followed according to conventional conditions or the conditions recommended by the manufacturer. All reagents or instruments used, unless otherwise specified, are conventional products obtained from commercial channels.

[0036] In the examples and comparative examples of the present invention, the brand of the silicone resin is KR-5230; the coupling agent is γ-aminopropyltriethoxysilane; the blue light absorber is blue light absorber BL1226; the catalyst is a platinum catalyst; and the curing agent is HDI curing agent.

[0037] The diameter of the cellulose nano whisker of the invention is 50-100 nm; the diameter of the fumed silica is 200-500 nm.

[0038] The preparation process of the acrylic acid ester polymer resin of the present invention is as follows:

[0039] Ethyl acrylate, methacrylic acid and azobisisobutyronitrile were weighed respectively in a mass ratio of 91:8:1; ethyl acrylate and methacrylic acid were added into a reaction device and mixed evenly, then the temperature was raised to 75°C, azobisisobutyronitrile was added, the temperature was raised to 80°C, and the reaction was carried out for 4 hours to obtain an acrylate polymer resin.

[0040] Example 1

[0041] A protective film for a mobile phone screen, comprising an AB adhesive film, a tempered glass substrate layer, and a release film layer (PET film); the AB adhesive film comprises a first adhesive layer, a PET film layer, and a second adhesive layer;

[0042] The first adhesive layer comprises the following raw materials in parts by weight: 45 parts of silicone resin, 3 parts of modified cellulose nano whiskers, 0.3 parts of coupling agent, 0.2 parts of blue light absorber, and 0.075 parts of catalyst;

[0043] The preparation process of the modified cellulose nano whiskers is as follows:

[0044] S1. Add 2,2,6,6-tetramethylpiperidinyl oxide (TEMPO), sodium bromide, and sodium hypochlorite to a 1 wt % aqueous solution of cellulose nanowhiskers. The ratio of cellulose nanowhiskers solution, TEMPO, sodium bromide, and sodium hypochlorite is 100 mL:130 mg:320 mg:18 mL. Adjust the pH of the solution to 10.5, react at room temperature for 6 h, dialyze for 5 days, and freeze-dry the dialyzate to produce carboxylated cellulose nanowhiskers.

[0045] S2. Take carboxylated cellulose nanowhiskers and add them to water. Adjust the pH to 5.5 with 1M hydrochloric acid solution. Then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and spermidine. The mass ratio of carboxylated cellulose nanowhiskers, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, spermidine and water is 1:1:1.2:4:60. React at room temperature for 20 hours, dialyze for 5 days, and freeze-dry the dialyzate to obtain the modified cellulose nanowhiskers. The electron micrograph of the obtained modified cellulose nanowhiskers is shown in the figure below. Figure 1 shown.

[0046] The second adhesive layer comprises the following raw materials in parts by weight: 55 parts of acrylic polymer resin, 3 parts of tackifier, and 0.075 parts of curing agent;

[0047] The preparation process of the tackifier is as follows: adding fumed silica to toluene containing bismuth neodecanoate, and then adding isocyanatepropyl triethoxysilane and hydroxyethyl acrylate, the mass ratio of fumed silica, bismuth neodecanoate, isocyanatepropyl triethoxysilane, hydroxyethyl acrylate and toluene is 1:0.2:0.4:0.4:8; heating to 75 ° C, reacting for 4 hours, and then vacuum distillation to separate the toluene, washing the product with deionized water and drying to obtain the tackifier, the scanning electron microscope image is shown as follows Figure 2 shown.

[0048] The method for preparing the mobile phone screen protective film comprises the following steps:

[0049] a. The silicone resin, modified cellulose nanowhiskers, coupling agent, blue light absorber, and catalyst were stirred and mixed for 1 hour to obtain a first adhesive layer;

[0050] b. Then the acrylate polymer resin, tackifier and curing agent were stirred for 1h to obtain a second adhesive layer;

[0051] c. A first adhesive layer is coated on the upper surface of the PET film layer; a second adhesive layer is then coated on the lower surface of the PET film layer and dried to obtain an AB film; wherein the thickness of the first adhesive layer is 75µm; the thickness of the second adhesive layer is 40µm;

[0052] d. Lay the tempered glass on the first adhesive layer of the AB adhesive film, and the PET film on the second adhesive layer of the AB adhesive film, and dry at 120℃.

[0053] Example 2

[0054] A protective film for a mobile phone screen, comprising an AB adhesive film, a tempered glass substrate layer, and a release film layer (PET film); the AB adhesive film comprises a first adhesive layer, a PET film layer, and a second adhesive layer;

[0055] The first adhesive layer comprises the following raw materials in parts by weight: 40 parts of silicone resin, 1 part of modified cellulose nano whiskers, 0.1 parts of coupling agent, 0.1 parts of blue light absorber, and 0.05 parts of catalyst;

[0056] The preparation process of the modified cellulose nano whiskers is as follows:

[0057] S1. TEMPO, sodium bromide, and sodium hypochlorite were added to a 2 wt % aqueous solution of cellulose nanowhiskers. The ratio of cellulose nanowhiskers solution, TEMPO, sodium bromide, and sodium hypochlorite was 100 mL:100 mg:300 mg:15 mL. The solution was adjusted to pH 10.2, reacted at room temperature for 5 h, dialyzed for 5 days, and the dialyzate was freeze-dried to produce carboxylated cellulose nanowhiskers.

[0058] S2. Take carboxylated cellulose nanowhiskers and add them to water. Adjust the pH to 6.0 with 1M hydrochloric acid solution, then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and spermidine. The mass ratio of carboxylated cellulose nanowhiskers, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, spermidine and water is 1:0.8:1.2:3:50. React at room temperature for 18 hours, dialyze for 5 days, and freeze-dry the dialyzate to obtain the product.

[0059] The second adhesive layer comprises the following raw materials in parts by weight: 50 parts of acrylate polymer resin, 1 part of tackifier, and 0.05 parts of curing agent;

[0060] The preparation process of the thickener is as follows: adding fumed silica to toluene containing bismuth neodecanoate, and then adding isocyanatepropyltriethoxysilane and hydroxyethyl acrylate, the mass ratio of fumed silica, bismuth neodecanoate, isocyanatepropyltriethoxysilane, hydroxyethyl acrylate and toluene is 1:0.1:0.3:0.3:5; heating to 70°C, reacting for 5 hours, and then distilling under reduced pressure to separate the toluene, washing the product with deionized water and drying to obtain the thickener.

[0061] The preparation method of the protective film for mobile phone screen is the same as that in Example 1.

[0062] Example 3

[0063] A protective film for a mobile phone screen, comprising an AB adhesive film, a tempered glass substrate layer, and a release film layer (PET film); the AB adhesive film comprises a first adhesive layer, a PET film layer, and a second adhesive layer;

[0064] The first adhesive layer comprises the following raw materials in parts by weight: 50 parts of silicone resin, 5 parts of modified cellulose nano whiskers, 0.5 parts of coupling agent, 0.3 parts of blue light absorber, and 0.1 parts of catalyst;

[0065] The preparation process of the modified cellulose nano whiskers is as follows:

[0066] S1. Add 2,2,6,6-tetramethylpiperidinyl oxide, sodium bromide, and sodium hypochlorite to a cellulose nanowhisker solution (3 wt%). The ratio of cellulose nanowhisker solution, TEMPO, sodium bromide, and sodium hypochlorite is 100 mL:150 mg:350 mg:20 mL. Adjust the pH of the solution to 11.2, react at room temperature for 7 h, dialyze for 5 days, and freeze-dry the dialyzate to produce carboxylated cellulose nanowhiskers.

[0067] S2. Take carboxylated cellulose nanowhiskers and add them to water. Adjust the pH to 6.5 with 1M hydrochloric acid solution, then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and spermidine. The mass ratio of carboxylated cellulose nanowhiskers, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, spermidine and water is 1:1.2:0.8:5:80. React at room temperature for 24 hours, dialyze for 5 days, and freeze-dry the dialyzate to obtain the product.

[0068] The second adhesive layer comprises the following raw materials in parts by weight: 60 parts of acrylic polymer resin, 5 parts of tackifier, and 0.1 parts of curing agent (HDI);

[0069] The preparation process of the thickener is as follows: adding fumed silica to toluene containing bismuth neodecanoate, and then adding isocyanatepropyltriethoxysilane and hydroxyethyl acrylate, the mass ratio of fumed silica, bismuth neodecanoate, isocyanatepropyltriethoxysilane, hydroxyethyl acrylate and toluene is 1:0.3:0.3:0.5:10; heating to 80°C, reacting for 3 hours, and then distilling under reduced pressure to separate toluene, washing the product with deionized water and drying to obtain the thickener.

[0070] The preparation method of the protective film for mobile phone screen is the same as that in Example 1.

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that the modified cellulose nanowhiskers are replaced with carboxylated cellulose nanowhiskers; the other contents are the same as those in Example 1.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 1 is that the tackifier is replaced with fumed silica; the rest is consistent with Example 1.

[0075] Test Example 1

[0076] In accordance with GB / T 2792-2014, the adhesion (at 180°) of the first adhesive layer obtained in step a and the second adhesive layer obtained in step b of Examples 1-3 and Comparative Examples 1-2 to PET film and tempered glass was measured. The test results are shown in Table 1.

[0077] Table 1

[0078]

[0079] The above results show that the AB adhesive films obtained in Examples 1-3 of the present invention have excellent bonding properties. The first adhesive layer has low adhesion, faces the tempered glass, bonds with the tempered glass, has low viscosity, and acts as a buffer for the mobile phone screen to disperse impact force.

[0080] The second adhesive layer has high adhesion properties. Facing the screen, peel off the PET film underneath the second adhesive layer to achieve adhesion to the phone screen. In Comparative Example 2, replacing the tackifier with fumed silica significantly reduced adhesion, demonstrating that the introduction of the tackifier improves the bonding strength of the second adhesive layer.

[0081] Test Example 2

[0082] Light transmittance was tested according to ASTM D1003-2013. The first adhesive layer obtained in step a and the second adhesive layer obtained in step b of Examples 1-3 and Comparative Examples 1-2 were coated onto different PET films. After curing, the films were placed at 85°C and 90% relative humidity for 24 hours and observed for signs of debonding and cracking. The test results are shown in Table 2.

[0083] Table 2

[0084]

[0085] The products of the present invention exhibit excellent light transmittance and high-temperature resistance, with light transmittance exceeding 93%, demonstrating excellent optical performance and high-definition characteristics. Furthermore, the products of the present invention exhibited no degumming or cracking under high-temperature and high-humidity conditions. However, in Comparative Example 1, where the modified cellulose nanowhiskers were replaced with carboxylated cellulose nanowhiskers, degumming and cracking occurred at the edges. This suggests that the introduction of the modified cellulose nanowhiskers in the present invention can reduce cracking and degumming in the first adhesive layer, extending the service life of the AB adhesive film.

[0086] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A protective film for mobile phone screen, characterized in that: The mobile phone screen protective film comprises an AB adhesive film; the AB adhesive film comprises a first adhesive layer, a PET film layer and a second adhesive layer arranged in sequence; The first adhesive layer comprises the following raw materials in parts by weight: 40-50 parts of silicone resin, 1-5 parts of modified cellulose nano whiskers, 0.1-0.5 parts of coupling agent, 0.1-0.3 parts of blue light absorber, and 0.05-0.1 parts of catalyst; The second adhesive layer comprises the following raw materials in parts by weight: 50-60 parts of acrylate polymer resin, 1-5 parts of tackifier, and 0.05-0.1 parts of curing agent. The preparation process of the modified cellulose nano whiskers is as follows: S1. Add 2,2,6,6-tetramethylpiperidinyl oxide, sodium bromide and sodium hypochlorite to the cellulose nanowhisker solution, adjust the pH of the solution to alkaline, react at room temperature, dialyze, and freeze-dry to obtain carboxylated cellulose nanowhiskers; S2. Take carboxylated cellulose nanowhiskers and add them to water, adjust the pH to 5.5-6.5, then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and spermidine, react at room temperature, dialyze, and freeze-dry to obtain; The preparation process of the tackifier is as follows: adding fumed silica to a solvent containing a catalyst, then adding isocyanatepropyltriethoxysilane and hydroxyethyl acrylate, heating and reacting to obtain the tackifier.

2. The mobile phone screen protective film according to claim 1, characterized in that: In step S1, the usage ratio of the cellulose nano whisker solution, 2,2,6,6-tetramethylpiperidinium oxide, sodium bromide and sodium hypochlorite is 100 mL: 100-150 mg: 300-350 mg: 15-20 mL; the reaction time is 5-7 hours; the concentration of the cellulose nano whisker solution is 1-3 wt%; and the alkalinity refers to a pH value of 10-11.

5.

3. The mobile phone screen protective film according to claim 1, characterized in that: In step S2, the mass ratio of the carboxylated cellulose nanowhiskers, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, spermidine and water is 1:(0.8-1.2):(0.8-1.2):(3-5):(50-80); and the reaction time is 18-24 hours.

4. The mobile phone screen protective film according to claim 1, characterized in that: The mass ratio of the fumed silica, catalyst, isocyanatepropyltriethoxysilane, hydroxyethyl acrylate and solvent is 1: (0.1-0.3): (0.3-0.5): (0.3-0.5): (5-10); the catalyst is bismuth neodecanoate; the solvent is toluene; the temperature of the heating reaction is 70-80°C, and the time is 3-5 hours.

5. The mobile phone screen protective film according to claim 1, characterized in that: The mobile phone screen protective film further comprises a substrate layer located on the first adhesive layer of the AB adhesive film and a release film layer located on the second adhesive layer of the AB adhesive film.

6. A mobile phone screen protective film according to claim 5, characterized in that: The substrate layer is tempered glass; the release film layer is PET film.

7. The mobile phone screen protective film according to claim 1, characterized in that: The coupling agent is γ-aminopropyltriethoxysilane; the blue light absorber is blue light absorber BL1226; the catalyst is a platinum catalyst; and the curing agent is an isocyanate curing agent.

8. The method for preparing a mobile phone screen protective film according to any one of claims 1 to 7, wherein: The steps include: a. Stir the silicone resin, modified cellulose nanowhiskers, coupling agent, blue light absorber, and catalyst to obtain a first adhesive layer; b. Then, the acrylate polymer resin, tackifier and curing agent are stirred to obtain a second adhesive layer; c. A first adhesive layer is coated on the upper surface of the PET film layer; a second adhesive layer is then coated on the lower surface of the PET film layer and dried to obtain an AB film; wherein the thickness of the first adhesive layer is 70-80µm; the thickness of the second adhesive layer is 38-45µm; d. Lay the substrate layer on the first adhesive layer of the AB adhesive film, and the release film layer on the second adhesive layer of the AB adhesive film, and dry at 110℃-120℃.

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