Pressure-sensitive adhesive label film and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a pressure-sensitive adhesive label film and a preparation method thereof. The pressure-sensitive adhesive label film is prepared from the following raw materials in parts by weight: 80 to 100 parts of polypropylene resin, 8 to 16 parts of composite filler, 3 to 6 parts of functionalized polysiloxane, 2 to 4 parts of plasticizer, 0.5 to 1.5 parts of antioxidant, 1.5 to 3.5 parts of lubricant and 0.1 to 0.3 part of initiator, polypropylene resin is used as a base material, and various functional aids are added, so that the transparency and weather resistance of the film material are comprehensively improved; wherein the composite filler utilizes a synergistic effect among mesoporous silica, TiO2 QDs and maleic anhydride, so that the transparency of the film is remarkably improved; the functional polysiloxane improves the weather resistance of the matrix in hot, wet and other environments, and prolongs the service life of the film.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a pressure-sensitive adhesive label film and a preparation method thereof. Background Art

[0002] Pressure-sensitive adhesive labels are mainly composed of three parts: face material, pressure-sensitive adhesive and backing paper. The face material, as the basic material of pressure-sensitive adhesive labels, usually includes paper, plastic film, etc. The plastic film materials mainly include polyester, polypropylene, polyethylene and polyvinyl chloride, etc. Compared with other materials, polypropylene film has lower cost, lighter weight, non-toxic and tasteless, and better moisture resistance.

[0003] However, polypropylene film still has some disadvantages: (1) its weather resistance is average. Under environmental conditions such as ultraviolet rays, oxygen, and moisture, it may undergo oxidative degradation, cross-linking, and breakage, resulting in reduced weather resistance; (2) its transparency is low. Due to the high crystallinity of the polypropylene molecular chain and its tendency to turn yellow under ultraviolet light, its transparency is reduced. These disadvantages limit the application of polypropylene film as a surface material for pressure-sensitive adhesive labels. Therefore, it is necessary to develop a polypropylene film with high transparency and good weather resistance as a surface material for pressure-sensitive adhesive labels. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a pressure-sensitive adhesive label film and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A pressure-sensitive adhesive label film comprises the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 8-16 parts of composite filler, 3-6 parts of functionalized polysiloxane, 2-4 parts of plasticizer, 0.5-1.5 parts of antioxidant, 1.5-3.5 parts of lubricant, and 0.1-0.3 parts of initiator; The plasticizer is diethyl phthalate, the antioxidant is one of antioxidant 1010 or antioxidant 168, the lubricant is calcium stearate, and the initiator is dibenzoyl peroxide; The composite filler is prepared by the following steps: Step A1, after mixing sodium hydroxide, hexadecyltrimethylammonium bromide, ethylene glycol and deionized water, heating to 60-80°C and stirring for 1 hour, adding tetraethyl orthosilicate and stirring for 3-6 hours, centrifuging, washing, drying, collecting the product, and then calcining at 550-600°C for 3-5 hours to obtain mesoporous silica; Further, in step A1, the dosage ratio of sodium hydroxide, hexadecyltrimethylammonium bromide, ethylene glycol, deionized water and tetraethyl orthosilicate is 0.15-0.45 g: 0.5-1.5 g: 40 mL: 200 mL: 4-12 mL; Step A2, ultrasonically dispersing mesoporous silica in deionized water, adding acetic acid under stirring, then adding tetrabutyl titanate ethanol solution and stirring evenly, then transferring the mixed solution to an autoclave, and hydrothermally treating it at 150-200° C. for 12-16 h, centrifuging, washing, and drying to obtain TiO2 QDs@SiO2 nanomaterials (titanium dioxide quantum dots loaded mesoporous silica nanomaterials); Further, in step A2, the amount ratio of mesoporous silica, deionized water, acetic acid and tetrabutyl titanate ethanol solution is 0.1-0.3 g: 50 mL: 50-100 mL: 2.5-7.5 mL, and the volume ratio of tetrabutyl titanate to ethanol in the tetrabutyl titanate ethanol solution is 1:10; Step A3, evenly disperse the TiO2 QDs@SiO2 nanomaterial in a mixture of deionized water and ethanol (the volume ratio of deionized water to ethanol is 2:8), then add KH-550 (silane coupling agent), heat to 45°C and stir to react for 4-6 hours, centrifuge, wash, dry, and collect the amino TiO2 QDs@SiO2 nanomaterial; then evenly disperse the amino TiO2 QDs@SiO2 nanomaterial in N,N-dimethylformamide (DMF), slowly add maleic anhydride DMF solution, heat to 45-55°C and stir to react for 5-10 hours, filter, wash, and dry to obtain a composite filler; Further, in step A3, the amount ratio of TiO2 QDs@SiO2 nanomaterial, mixed solution and KH-550 in the amination of TiO2 QDs@SiO2 nanomaterial is 1-3 g: 100 mL: 0.5-1.5 mL; Furthermore, in step A3, the amount ratio of the aminated TiO2 QDs@SiO2 nanomaterial, DMF and maleic anhydride DMF solution in the composite filler is 2-3 g:50 mL:50 mL, and the amount ratio of maleic anhydride to DMF in the maleic anhydride DMF solution is 0.01-0.02 mol:50 mL.

[0006] The functionalized polysiloxane is prepared by the following steps: Step B1, add propylene oxide to DMF, heat to 135-145°C under nitrogen, then add imidazole and 3-isocyanatepropyltrimethoxysilane, stir to react for 2-3h, distill under reduced pressure, and dry to obtain a functional monomer; Further, in step B1, the usage ratio of propylene oxide, DMF, imidazole and 3-isocyanatepropyltrimethoxysilane is 0.1-0.2 mol: 100 mL: 0.006-0.012 g: 0.1-0.2 mol; Step B2, octamethylcyclotetrasiloxane and hexamethyldisiloxane are mixed and stirred evenly, and the temperature is raised to 40-60°C, concentrated sulfuric acid is added and stirred evenly, and then KH-570 (silane coupling agent), methyltrifluoropropylcyclotrisiloxane, hexadecyltrimethoxysilane and functional monomer are added and stirred for 5-7h, cooled, anhydrous sodium carbonate is added and stirred for 10min, and filtered to obtain functionalized polysiloxane; Furthermore, in step B2, the mass ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, KH-570, methyltrifluoropropylcyclotrisiloxane, hexadecyltrimethoxysilane and functional monomer is 3-5: 2-3: 0.1-0.3: 0.2-0.5: 0.1-0.2: 0.2-0.4, and the amount of concentrated sulfuric acid used is 0.3%-0.6% of the total mass of the reactants.

[0007] A method for preparing a pressure-sensitive adhesive label film comprises the following steps: Step S1, weighing raw materials by weight, polypropylene resin, composite filler, functionalized polysiloxane, plasticizer, antioxidant, lubricant and initiator, stirring them evenly with a high-speed stirrer, and putting them into a twin-screw extruder for melt extrusion to form a melt, and the extrusion temperature of the twin-screw extruder is 220-240° C.; Step S2, extruding the melt in step S1 through a T-die, and then calendering and shaping the melt extruded through the T-die through three rollers to form a film, and then trimming, corona, and winding to obtain a pressure-sensitive adhesive label film. The thickness of the film formed by shaping is 60-80 μm.

[0008] Beneficial effects of the present invention: The pressure-sensitive adhesive label film of the present invention is based on polypropylene resin and is added with various functional additives to comprehensively improve the transparency and weather resistance of the film material; wherein the composite filler utilizes the synergistic effect between mesoporous silica, TiO2 QDs and maleic anhydride to significantly improve the transparency of the film; the functionalized polysiloxane improves the weather resistance of the substrate in hot, humid and other environments, and prolongs the service life of the film.

[0009] In the composite filler, mesoporous silica was first synthesized using tetraethyl orthosilicate as raw material and hexadecyltrimethylammonium bromide as template; TiO2 QDs were then loaded on the mesoporous silica using tetrabutyl titanate as raw material to obtain TiO2 QDs@SiO2 nanomaterials; finally, the nanomaterials were surface modified using a silane coupling agent, and maleic anhydride was grafted onto the surface of the nanomaterials to obtain a composite filler. The composite filler utilizes the synergistic effect between mesoporous silica, TiO2 QDs and maleic anhydride to significantly improve the transparency of the film; among them, mesoporous silica as a substrate can utilize its own high transparency and then load TiO2 QDs to further improve the transparency of the film. This is because TiO2 QDs have excellent ultraviolet absorption ability, which can effectively reduce the photodegradation reaction of polypropylene molecular chains due to ultraviolet irradiation, reduce molecular chain degradation and discoloration, thereby reducing the reduction in transparency caused by yellowing; in addition, the maleic anhydride groups grafted on the surface of the composite filler can also copolymerize with the polypropylene molecular chains, destroying the regularity and orderliness of the polypropylene molecular chains, hindering the formation of crystals, reducing the crystallinity, and thereby reducing the scattering and refraction of light on the polypropylene film, thereby improving the transparency of the film.

[0010] Functionalized polysiloxane improves the weather resistance of the film in the matrix. This is due to the synergistic effect of the introduced long-chain hydrophobic alkyl, silicon-oxygen bond and fluorine element, which improves the water resistance of the film. The oxazolidinone ring has excellent heat resistance and can effectively improve the heat resistance of the film, thereby improving the weather resistance of the matrix in hot and humid environments and extending the service life of the film. In addition, the double bonds in the functional polysiloxane can also participate in the copolymerization of polypropylene resin, reduce the crystallinity and improve the transparency of the film. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0012] Example 1: The composite filler is prepared by the following steps: Step A1, 0.15g sodium hydroxide, 0.5g hexadecyltrimethylammonium bromide, 40mL ethylene glycol and 200mL deionized water were mixed, the temperature was raised to 60°C and stirred for 1h, 4mL tetraethyl orthosilicate was added and stirred for 3h, centrifuged, washed, dried, the product was collected, and then calcined at 550°C for 3h to obtain mesoporous silica; Step A2, 0.1 g of mesoporous silica was uniformly dispersed in 50 mL of deionized water by ultrasonication, 50 mL of acetic acid was added under stirring, and then 2.5 mL of tetrabutyl titanate ethanol solution was added and stirred evenly, and then the mixed solution was transferred to an autoclave, and hydrothermally treated at 150° C. for 12 h, centrifuged, washed, and dried to obtain TiO2 QDs@SiO2 nanomaterials, wherein the volume ratio of tetrabutyl titanate to ethanol in the tetrabutyl titanate ethanol solution was 1:10; Step A3, evenly disperse 1g TiO2 QDs@SiO2 nanomaterial in 100mL deionized water and ethanol mixture (the volume ratio of deionized water to ethanol is 2:8), then add 0.5mL KH-550, heat to 45℃ and stir to react for 4h, centrifuge, wash, dry, and collect the amino TiO2 QDs@SiO2 nanomaterial; then evenly disperse 2g of amino TiO2 QDs@SiO2 nanomaterial in 50mL N,N-dimethylformamide, slowly add 50mL maleic anhydride DMF solution, heat to 45℃ and stir to react for 5h, filter, wash, and dry to obtain a composite filler, and the amount ratio of maleic anhydride to DMF in the maleic anhydride DMF solution is 0.01mol:50mL.

[0013] Functionalized polysiloxane is prepared by the following steps: Step B1, add 0.1 mol of propylene oxide to 100 mL of DMF, heat to 135° C. under nitrogen, then add 0.006 g of imidazole and 0.1 mol of 3-isocyanatepropyltrimethoxysilane, stir to react for 2 h, distill under reduced pressure, and dry to obtain a functional monomer; Step B2, 3g of octamethylcyclotetrasiloxane and 2g of hexamethyldisiloxane are blended and stirred evenly, and the temperature is raised to 40°C, concentrated sulfuric acid is added and stirred evenly, and then 0.1g of KH-570, 0.2g of methyltrifluoropropylcyclotrisiloxane, 0.1g of hexadecyltrimethoxysilane and 0.2g of functional monomer are added and stirred for 5h, cooled, anhydrous sodium carbonate is added and stirred for 10min, and filtered to obtain functionalized polysiloxane. The amount of concentrated sulfuric acid is 0.3% of the total mass of the reactants.

[0014] Example 2: The composite filler is prepared by the following steps: Step A1, 0.3 g of sodium hydroxide, 1 g of hexadecyltrimethylammonium bromide, 40 mL of ethylene glycol and 200 mL of deionized water were mixed, the temperature was raised to 70° C. and stirred for 1 h, 8 mL of tetraethyl orthosilicate was added and stirred for 4.5 h, centrifuged, washed, dried, the product was collected, and then calcined at 580° C. for 4 h to obtain mesoporous silica; Step A2, 0.2 g of mesoporous silica was uniformly dispersed in 50 mL of deionized water by ultrasonication, 75 mL of acetic acid was added under stirring, and then 5 mL of tetrabutyl titanate ethanol solution was added and stirred evenly, and then the mixed solution was transferred to an autoclave, and hydrothermally treated at 170°C for 14 h, centrifuged, washed, and dried to obtain TiO2 QDs@SiO2 nanomaterials, wherein the volume ratio of tetrabutyl titanate to ethanol in the tetrabutyl titanate ethanol solution was 1:10; Step A3, evenly disperse 2g TiO2 QDs@SiO2 nanomaterial in 100mL deionized water and ethanol mixture (the volume ratio of deionized water and ethanol is 2:8), then add 1mL KH-550, heat to 45℃ and stir to react for 5h, centrifuge, wash, dry, and collect the amino TiO2 QDs@SiO2 nanomaterial; then evenly disperse 2.5g amino TiO2 QDs@SiO2 nanomaterial in 50mL N,N-dimethylformamide, slowly add 50mL maleic anhydride DMF solution, heat to 50℃ and stir to react for 7h, filter, wash, and dry to obtain a composite filler, and the amount ratio of maleic anhydride to DMF in the maleic anhydride DMF solution is 0.015mol:50mL.

[0015] Functionalized polysiloxane is prepared by the following steps: Step B1, add 0.15 mol of propylene oxide to 100 mL of DMF, heat to 140° C. under nitrogen, then add 0.009 g of imidazole and 0.15 mol of 3-isocyanatepropyltrimethoxysilane, stir to react for 2.5 h, distill under reduced pressure, and dry to obtain a functional monomer; Step B2, 4g of octamethylcyclotetrasiloxane and 2.5g of hexamethyldisiloxane were blended and stirred evenly, and the temperature was raised to 50°C, concentrated sulfuric acid was added and stirred evenly, and then 0.2g of KH-570, 0.35g of methyltrifluoropropylcyclotrisiloxane, 0.15g of hexadecyltrimethoxysilane and 0.3g of functional monomer were added and stirred for 6h, cooled, anhydrous sodium carbonate was added and stirred for 10min, and filtered to obtain functionalized polysiloxane. The amount of concentrated sulfuric acid was 0.45% of the total mass of the reactants.

[0016] Example 3: The composite filler is prepared by the following steps: Step A1, 0.45g sodium hydroxide, 1.5g hexadecyltrimethylammonium bromide, 40mL ethylene glycol and 200mL deionized water were mixed, the temperature was raised to 80°C and stirred for 1h, 12mL tetraethyl orthosilicate was added and stirred for 6h, centrifuged, washed and dried, the product was collected, and then calcined at 600°C for 5h to obtain mesoporous silica; Step A2, 0.3 g of mesoporous silica was uniformly dispersed in 50 mL of deionized water by ultrasonication, 100 mL of acetic acid was added under stirring, and 7.5 mL of tetrabutyl titanate ethanol solution was added and stirred evenly, and the mixed solution was transferred to an autoclave, and hydrothermally treated at 200 ° C for 16 h, centrifuged, washed, and dried to obtain TiO2 QDs@SiO2 nanomaterials, and the volume ratio of tetrabutyl titanate to ethanol in the tetrabutyl titanate ethanol solution was 1:10; Step A3, evenly disperse 3g of TiO2 QDs@SiO2 nanomaterial in 100mL of a mixture of deionized water and ethanol (the volume ratio of deionized water to ethanol is 2:8), then add 1.5mL of KH-550, heat to 45°C and stir to react for 6h, centrifuge, wash, dry, and collect the amino TiO2 QDs@SiO2 nanomaterial; then evenly disperse 3g of amino TiO2 QDs@SiO2 nanomaterial in 50mL of N,N-dimethylformamide, slowly add 50mL of maleic anhydride DMF solution, heat to 55°C and stir to react for 10h, filter, wash, and dry to obtain a composite filler, and the amount ratio of maleic anhydride to DMF in the maleic anhydride DMF solution is 0.02mol:50mL.

[0017] Functionalized polysiloxane is prepared by the following steps: Step B1, add 0.2 mol of propylene oxide to 100 mL of DMF, heat to 145° C. under nitrogen, then add 0.012 g of imidazole and 0.2 mol of 3-isocyanatepropyltrimethoxysilane, stir to react for 3 h, distill under reduced pressure, and dry to obtain a functional monomer; Step B2, 5g of octamethylcyclotetrasiloxane and 3g of hexamethyldisiloxane were blended and stirred evenly, and the temperature was raised to 60°C, concentrated sulfuric acid was added and stirred evenly, and then 0.3g of KH-570, 0.5g of methyltrifluoropropylcyclotrisiloxane, 0.2g of hexadecyltrimethoxysilane and 0.4g of functional monomer were added and stirred for 7h, cooled, anhydrous sodium carbonate was added and stirred for 10min, and filtered to obtain functionalized polysiloxane. The amount of concentrated sulfuric acid was 0.6% of the total mass of the reactants.

[0018] Embodiment 4: A method for preparing a pressure-sensitive adhesive label film comprises the following steps: 80 parts of polypropylene resin, 8 parts of the composite filler prepared in Example 1, 3 parts of the functionalized polysiloxane prepared in Example 1, 2 parts of diethyl phthalate, 0.5 parts of antioxidant 1010, 1.5 parts of lubricant, and 0.1 parts of initiator; Step S1, weighing raw materials by weight, polypropylene resin, the composite filler prepared in Example 1, the functionalized polysiloxane prepared in Example 1, diethyl phthalate, antioxidant 1010, calcium stearate and dibenzoyl peroxide, stirring them evenly with a high-speed stirrer, and putting them into a twin-screw extruder for melt extrusion to form a melt, and the extrusion temperature of the twin-screw extruder is 220° C.; Step S2, extruding the melt in step S1 through a T-die, and then calendering and shaping the melt extruded through the T-die through three rollers to form a film, and then trimming, corona, and winding to obtain a pressure-sensitive adhesive label film. The thickness of the film formed by shaping is 60 μm.

[0019] Embodiment 5: A method for preparing a pressure-sensitive adhesive label film comprises the following steps: 90 parts of polypropylene resin, 12 parts of the composite filler prepared in Example 2, 4.5 parts of the functionalized polysiloxane prepared in Example 2, 3 parts of diethyl phthalate, 1 part of antioxidant 168, 2.5 parts of lubricant, and 0.2 parts of initiator; Step S1, weighing raw materials by weight, polypropylene resin, the composite filler prepared in Example 2, the functionalized polysiloxane prepared in Example 2, diethyl phthalate, antioxidant 168, calcium stearate and dibenzoyl peroxide, stirring them evenly with a high-speed stirrer, and putting them into a twin-screw extruder for melt extrusion to form a melt, and the extrusion temperature of the twin-screw extruder is 230° C.; Step S2, extruding the melt in step S1 through a T-die, and then calendering and shaping the melt extruded through the T-die through three rollers to form a film, and then trimming, corona, and winding to obtain a pressure-sensitive adhesive label film. The thickness of the film formed by shaping is 70 μm.

[0020] Embodiment 6: A method for preparing a pressure-sensitive adhesive label film comprises the following steps: 100 parts of polypropylene resin, 16 parts of the composite filler prepared in Example 3, 6 parts of the functionalized polysiloxane prepared in Example 3, 4 parts of diethyl phthalate, 1.5 parts of antioxidant 168, 3.5 parts of lubricant, and 0.3 parts of initiator; Step S1, weighing raw materials by weight, polypropylene resin, the composite filler prepared in Example 3, the functionalized polysiloxane prepared in Example 3, diethyl phthalate, antioxidant 168, calcium stearate and dibenzoyl peroxide, stirring them evenly with a high-speed stirrer, and putting them into a twin-screw extruder for melt extrusion to form a melt, and the extrusion temperature of the twin-screw extruder is 240° C.; Step S2, extruding the melt in step S1 through a T-die, and then calendering and shaping the melt extruded through the T-die through three rollers to form a film, and then trimming, corona, and winding to obtain a pressure-sensitive adhesive label film. The thickness of the film formed by shaping is 80 μm.

[0021] Comparative Example 1: This comparative example is a pressure-sensitive adhesive label film, which differs from Example 6 in that nano-silicon dioxide is used instead of the composite filler prepared in Example 3, and the rest are the same.

[0022] Comparative Example 2: This comparative example is a pressure-sensitive adhesive label film. The difference from Example 6 is that commercially available polysiloxane is used instead of the functionalized polysiloxane prepared in Example 3, and the rest is the same.

[0023] The pressure-sensitive adhesive label films prepared in Examples 4-6 and Comparative Examples 1-2 were subjected to performance tests: Light transmittance test: Test light transmittance in accordance with GB / T 2410-2008 standard; Weathering test: According to GB / T 16422.3-2014 standard, the sample was tested in a UVA-340 test chamber: 8 hours of drying + 4 hours of condensation as one cycle, and 6 cycles were carried out for a total of 72 hours. The colorimeter was used to measure the data of the sample under the D65 light source before and after the sample was placed in the test chamber. The color difference before and after was compared and expressed as △E. The larger the △E, the worse the weathering resistance; The test results are shown in Table 1:

[0024] As can be seen from Table 1, the pressure-sensitive adhesive label film prepared by the present invention has a transmittance test and a weather resistance test, and the transmittance is in the range of (93.3-94.2)%, and the color difference change △E is in the range of 0.4-0.5, indicating that the film material has good light transmittance and weather resistance, and has a good application prospect in pressure-sensitive adhesive label surface materials.

[0025] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A pressure-sensitive adhesive label film and a method for preparing the same, characterized in that: The invention comprises the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 8-16 parts of composite filler, 3-6 parts of functionalized polysiloxane, 2-4 parts of plasticizer, 0.5-1.5 parts of antioxidant, 1.5-3.5 parts of lubricant and 0.1-0.3 parts of initiator; The composite filler is prepared by the following steps: Step A1, after mixing sodium hydroxide, hexadecyltrimethylammonium bromide, ethylene glycol and deionized water, heating to 60-80°C and stirring for 1 hour, adding tetraethyl orthosilicate and stirring for 3-6 hours, centrifuging, washing, drying, collecting the product, and then calcining at 550-600°C for 3-5 hours to obtain mesoporous silica; Step A2, uniformly dispersing mesoporous silica in deionized water by ultrasonication, adding acetic acid under stirring, then adding tetrabutyl titanate ethanol solution and stirring evenly, then transferring the mixed solution to an autoclave, and hydrothermally treating it at 150-200° C. for 12-16 h, centrifuging, washing, and drying to obtain TiO2 QDs@SiO2 nanomaterials; Step A3, disperse the TiO2 QDs@SiO2 nanomaterial evenly in a mixture of deionized water and ethanol, then add KH-550, heat to 45°C and stir to react for 4-6 hours, centrifuge, wash, dry, and collect the amino TiO2 QDs@SiO2 nanomaterial; then disperse the amino TiO2 QDs@SiO2 nanomaterial evenly in N,N-dimethylformamide, slowly add maleic anhydride DMF solution, heat to 45-55°C and stir to react for 5-10 hours, filter, wash, and dry to obtain a composite filler.

2. The pressure-sensitive adhesive label film according to claim 1, characterized in that: In step A1, the dosage ratio of sodium hydroxide, hexadecyltrimethylammonium bromide, ethylene glycol, deionized water and tetraethyl orthosilicate is 0.15-0.45 g: 0.5-1.5 g: 40 mL: 200 mL: 4-12 mL.

3. The pressure-sensitive adhesive label film according to claim 1, characterized in that: In step A2, the usage ratio of mesoporous silica, deionized water, acetic acid and tetrabutyl titanate ethanol solution is 0.1-0.3 g:50 mL:50-100 mL:2.5-7.5 mL, and the volume ratio of tetrabutyl titanate to ethanol in the tetrabutyl titanate ethanol solution is 1:

10.

4. The pressure-sensitive adhesive label film according to claim 1, characterized in that: In step A3, the dosage ratio of TiO2 QDs@SiO2 nanomaterial, mixed solution and KH-550 in the amination of TiO2 QDs@SiO2 nanomaterial is 1-3 g: 100 mL: 0.5-1.5 mL.

5. The pressure-sensitive adhesive label film according to claim 1, characterized in that: Step A3: The amount ratio of the aminated TiO2 QDs@SiO2 nanomaterial, DMF and maleic anhydride DMF solution in the composite filler is 2-3 g: 50 mL: 50 mL, and the amount ratio of maleic anhydride to DMF in the maleic anhydride DMF solution is 0.01-0.02 mol: 50 mL.

6. The pressure-sensitive adhesive label film according to claim 1, characterized in that: The functionalized polysiloxane is prepared by the following steps: Step B1, add propylene oxide to DMF, heat to 135-145°C under nitrogen, then add imidazole and 3-isocyanatepropyltrimethoxysilane, stir to react for 2-3h, distill under reduced pressure, and dry to obtain a functional monomer; Step B2, octamethylcyclotetrasiloxane and hexamethyldisiloxane are blended and stirred evenly, and the temperature is raised to 40-60°C, concentrated sulfuric acid is added and stirred evenly, and then KH-570, methyltrifluoropropylcyclotrisiloxane, hexadecyltrimethoxysilane and functional monomers are added and stirred for 5-7h, cooled, anhydrous sodium carbonate is added and stirred for 10min, and filtered to obtain functionalized polysiloxane.

7. The pressure-sensitive adhesive label film according to claim 6, characterized in that: In step B1, the usage ratio of propylene oxide, DMF, imidazole and 3-isocyanatepropyltrimethoxysilane is 0.1-0.2 mol:100 mL:0.006-0.012 g:0.1-0.2 mol.

8. The pressure-sensitive adhesive label film according to claim 6, characterized in that: In step B2, the mass ratio of octamethylcyclotetrasiloxane, hexamethyldisiloxane, KH-570, methyltrifluoropropylcyclotrisiloxane, hexadecyltrimethoxysilane and functional monomer is 3-5: 2-3: 0.1-0.3: 0.2-0.5: 0.1-0.2: 0.2-0.4, and the amount of concentrated sulfuric acid used is 0.3%-0.6% of the total mass of the reactants.

9. The pressure-sensitive adhesive label film according to claim 1, characterized in that: The plasticizer is diethyl phthalate, the antioxidant is one of antioxidant 1010 and antioxidant 168, the lubricant is calcium stearate, and the initiator is dibenzoyl peroxide.

10. A method for preparing the pressure-sensitive adhesive label film according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, weighing raw materials by weight, polypropylene resin, composite filler, functionalized polysiloxane, plasticizer, antioxidant, lubricant and initiator, stirring them evenly with a high-speed stirrer, and putting them into a twin-screw extruder for melt extrusion to form a melt, and the extrusion temperature of the twin-screw extruder is 220-240° C.; Step S2, extruding the melt in step S1 through a T-die, and then calendering and shaping the melt extruded through the T-die through three rollers to form a film, and then trimming, corona, and winding to obtain a pressure-sensitive adhesive label film. The thickness of the film formed by shaping is 60-80 μm.

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