Automobile film with heat-insulating and hydrophobic effects and preparation method thereof
By preparing a blend of composite modifier and grafted modified polypropylene and biaxially stretching, the problems of functional component migration and poor compatibility in automotive films were solved, achieving long-lasting stability and synergistic effect of the hydrophobic and heat insulation properties of automotive films.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SINOMA TECH SERVICE (BEIJING) CO LTD
- Filing Date
- 2026-01-27
- Publication Date
- 2026-04-17
AI Technical Summary
The functional components of existing automotive films are prone to migration and failure, and their hydrophobic and weather-resistant properties deteriorate rapidly over time. Furthermore, the inorganic heat-insulating fillers have poor compatibility with organic polymers, affecting the film's light transmittance and long-term stability.
A composite modifier was prepared by free radical polymerization of fluorinated monomers, oleic acid, and reactive ultraviolet absorbers with alkenyl-modified ATO/TiO2. Graft-modified polypropylene was melt-blended with the composite modifier, and automotive films were prepared by biaxial stretching to form strong covalent bonds.
The hydrophobicity and UV aging resistance of polypropylene were improved, the problems of functional component migration and poor compatibility were solved, and the performance stability and synergistic effect of modified polypropylene were achieved.
Smart Images
Figure CN121873397A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer composite materials technology, specifically relating to an automotive film with heat insulation and hydrophobic properties and its preparation method. Background Technology
[0002] With the development of the automotive industry, consumers' demands for driving comfort and car maintenance are increasing, leading to the widespread application of functional automotive films (such as heat-insulating window films and paint protection films). An ideal automotive film should possess the following functions: excellent heat insulation performance, blocking near-infrared rays from sunlight to reduce heat accumulation inside the vehicle; good hydrophobic properties, preventing rainwater from adhering, maintaining clear visibility, and easy cleaning; and excellent weather resistance and UV aging resistance to ensure long-term use without yellowing, cracking, or peeling.
[0003] Most automotive films currently on the market employ a multi-layered composite structure. The functional layer typically incorporates functional fillers (such as infrared blocking agents like ITO and ATO) and additives (such as fluorinated hydrophobic agents and UV absorbers) through physical blending or coating. However, this physical doping method has the following inherent drawbacks: functional components are prone to migration and failure. Small molecule additives such as antioxidants and UV absorbers, as well as low surface energy components like hydrophobic agents, are easily lost to the surface during long-term use or under high-temperature environments, leading to a rapid decline in hydrophobic and weather-resistant properties over time. Interfacial compatibility is poor. Inorganic heat-insulating fillers (such as ATO) have poor compatibility with the organic polymer matrix, easily agglomerating and affecting the film's light transmittance, mechanical properties, and long-term stability. Functionality is limited. Heat insulation, hydrophobicity, and weather resistance are usually provided by different additives, resulting in complex formulations and potential interference between components, making it difficult to achieve sustained performance stability and synergistic effects.
[0004] Therefore, developing an integrated automotive membrane material with stable functional components, durable performance, and synergistic effects among its various functions is of great practical significance. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides an automotive film with heat insulation and hydrophobic properties, as well as a method for its preparation.
[0006] A method for preparing an automotive film with heat insulation and hydrophobic properties includes the following steps: Step 1: A composite modifier is prepared by reacting fluorinated monomers, oleic acid, reactive ultraviolet absorbers, and alkenyl-modified ATO / TiO2. Step 2: Polypropylene reacts with glycidyl methacrylate and styrene to obtain grafted modified polypropylene; the grafted modified polypropylene is melt-blended with a composite modifier, extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties.
[0007] Preferably, in step one, the preparation method of the composite modifier specifically includes: adding a fluorinated monomer, oleic acid, a reactive ultraviolet absorber and an alkenyl-modified ATO / TiO2 to toluene to obtain a mixed monomer dispersion; heating the mixed monomer dispersion to a set temperature; adding an initiator solution dropwise; after the addition is complete, reacting; after the reaction is complete, separating and purifying, and drying to obtain the composite modifier.
[0008] Preferably, the mass ratio of fluorinated monomer, oleic acid, reactive ultraviolet absorber, and alkenyl-modified ATO / TiO2 is (3-5):(2-3.6):(2-4):(4-6); the amount of toluene is 3-5 times the sum of the mass of fluorinated monomer, oleic acid, reactive ultraviolet absorber, and alkenyl-modified ATO / TiO2; the content of initiator in the initiator solution is 1%-3% of the sum of the mass of fluorinated monomer, oleic acid, reactive ultraviolet absorber, and alkenyl-modified ATO / TiO2; the reaction conditions are: reaction in a nitrogen atmosphere at a set temperature for 20-28 hours; the set temperature is 65-75℃.
[0009] Preferably, the fluorinated monomer includes dodecafluoroheptyl methacrylate, the reactive ultraviolet absorber includes 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and the initiator solution includes a 2,2'-azobisisobutyronitrile (AIBN) solution.
[0010] Preferably, the 2,2'-azobisisobutyronitrile solution is prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:(10-20).
[0011] Preferably, the alkenyl-modified ATO / TiO2 is prepared by the following steps: Step (1): Dissolve tin chloride pentahydrate and antimony chloride in deionized water, add carbon microspheres, disperse by ultrasonication, adjust the pH to 8-9, react, filter, wash, dry, and calcine to obtain ATO (antimony tin oxide). Step (2): Dissolve titanium tetrachloride in deionized water, add ATO, adjust the pH to 7, react, filter, wash, and dry to obtain ATO / TiO2. Step (3): Add ATO / TiO2 and γ-methacryloxypropyltrimethoxysilane (silane coupling agent KH-570) to an ethanol aqueous solution, disperse by ultrasonication, adjust the pH value to 3-5, and react. After the reaction is completed, filter, wash, and dry to obtain alkenyl-modified ATO / TiO2.
[0012] Preferably, in step (1), the mass ratio of tin chloride pentahydrate, antimony chloride, deionized water, and carbon microspheres is (24-30):(1.8-2.2):(60-80):(1-1.4), the reaction conditions are 6-8 h at 30-40℃, and the calcination conditions are 1-2 h at 500-600℃; in step (2), the mass ratio of titanium tetrachloride, ATO, and deionized water is (8-10):10:(400-600), and the reaction conditions are 6-8 h at 70-80℃; in step (3), the mass ratio of ATO / TiO2, γ-methacryloyloxypropyltrimethoxysilane, and aqueous ethanol solution is 10:(15-20):(300-400), and the reaction conditions are 8-12 h at 70-80℃.
[0013] Preferably, the ethanol aqueous solution is a 95wt% ethanol aqueous solution.
[0014] Preferably, the preparation method of grafted modified polypropylene in step two specifically includes: Polypropylene, benzoyl peroxide and xylene were mixed and swollen. Under nitrogen protection, glycidyl methacrylate and styrene were added and reacted. After the reaction was completed, the mixture was purified to obtain grafted modified polypropylene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:(10-20):(2-4):(2.8-3.5):(2.1-2.7). The swelling conditions are stirring at 35-45℃ for 40-60 min and reaction conditions are reacting at 90-110℃ for 1.5-2.5 h under nitrogen protection, at a stirring speed of 100-200 r / min.
[0015] Preferably, in step two, when preparing the modified polypropylene masterbatch, the mass ratio of grafted modified polypropylene to composite modifier is 100:(3-5), and the melt blending temperature is 180-200℃.
[0016] Preferably, in step three, the melting temperature is 180-200℃, and the biaxial stretching is performed sequentially in the longitudinal and transverse directions. The longitudinal stretching temperature is 100-120℃, and the stretching ratio is 4-6 times. The transverse stretching temperature is 160-180℃, and the stretching ratio is 8-10 times.
[0017] Preferably, the thickness of the automotive film with heat insulation and hydrophobic properties is 60-100 μm.
[0018] The present invention also discloses an automotive film with heat insulation and hydrophobic properties prepared by the above-described method for preparing an automotive film with heat insulation and hydrophobic properties.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, polypropylene is used as the resin matrix, and fluorinated monomers, oleic acid, reactive ultraviolet absorbers, and alkenyl-modified ATO / TiO2 are used as raw materials. A composite modifier is prepared through free radical polymerization. The introduction of hydrophobic substances, fluorinated monomers and oleic acid, into the composite modifier can effectively improve the hydrophobic properties of polypropylene; the introduction of ultraviolet absorbers can effectively improve the anti-ultraviolet aging properties of polypropylene; the introduction of ATO / TiO2 can not only effectively improve the infrared blocking properties of polypropylene, but also further improve the anti-ultraviolet aging properties of polypropylene; the fluorinated monomers, oleic acid, reactive ultraviolet absorbers, and alkenyl-modified ATO / TiO2 are all linked by polymer molecular chains, which can effectively avoid the migration problems of small organic molecule additives in the resin matrix and the poor compatibility problems of inorganic nanoparticles in the resin matrix. In this invention, the polypropylene undergoes graft modification, which effectively increases the polarity of the polypropylene molecular chain, thereby improving its compatibility with the composite modifier and achieving long-lasting stability of the modified polypropylene's thermal insulation and hydrophobic properties. Furthermore, by grafting glycidyl methacrylate onto the polypropylene, highly active epoxy groups are introduced. During melt blending, the carboxyl groups introduced by oleic acid on the composite modifier can undergo an in-situ ring-opening reaction with the epoxy groups on the grafted modified polypropylene molecules, forming a strong covalent bond. This anchors the functional components within the polypropylene resin matrix network, fundamentally solving the performance degradation problem caused by the migration of small organic molecule additives and the poor compatibility between inorganic nanoparticles and the polypropylene resin matrix, further improving the performance stability of the modified polypropylene. Attached Figure Description
[0020] Figure 1 The graph shows the results of measuring the infrared and ultraviolet blocking properties of the automotive films prepared in Examples 2-6 and Comparative Examples 1-2 of this invention. Figure 2 The graph shows the hydrophobic properties of the automotive films prepared in Examples 2-6 and Comparative Examples 1-2 of this invention. Detailed Implementation
[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0022] Example 1 This embodiment discloses a method for preparing alkenyl-modified ATO / TiO2, including the following steps: Step (1): Dissolve tin chloride pentahydrate and antimony chloride in deionized water, add carbon microspheres, the mass ratio of tin chloride pentahydrate, antimony chloride, deionized water and carbon microspheres is 27:2:70:1.2, ultrasonically disperse at 50kHz frequency for 30min, add 1mol / L sodium hydroxide aqueous solution to adjust the pH value to 8.5, react at 35℃ for 7h, after the reaction is completed, filter, wash the filter cake with deionized water and ethanol three times in sequence, place it in a vacuum drying oven at 50℃ to dry to constant weight, calcine at 550℃ for 1.5h to obtain ATO; Step (2): Dissolve titanium tetrachloride in deionized water, add ATO, the mass ratio of titanium tetrachloride, ATO and deionized water is 9:10:500, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH value to 7, react at 75℃ for 7h, after the reaction is completed, filter, wash the filter cake 3 times with deionized water, place it in a vacuum drying oven at 50℃ and dry to constant weight to obtain ATO / TiO2; Step (3): Add ATO / TiO2 and γ-methacryloxypropyltrimethoxysilane to a 95wt% ethanol aqueous solution. The mass ratio of ATO / TiO2, γ-methacryloxypropyltrimethoxysilane and 95wt% ethanol aqueous solution is 10:18:350. After ultrasonic dispersion at 50kHz for 30min, add 1mol / L hydrochloric acid solution to adjust the pH to 4. React at 75℃ for 10h. After the reaction is completed, filter, wash the filter cake three times with ethanol, and dry it in a vacuum drying oven at 50℃ until constant weight to obtain alkenyl modified ATO / TiO2.
[0023] Example 2 This embodiment discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 3:2:2:4. The amount of toluene used is 3 times the sum of the masses of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 65℃. A 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 1% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 65 °C for 28 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50 °C to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:10. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 35°C for 60 min to allow swelling. Under nitrogen protection, add glycidyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:10:2:2.8:2.1. Under nitrogen protection, react at 90°C with a stirring speed of 100 r / min for 2.5 h. After the reaction is complete, wash with acetone and filter, then dry in a vacuum drying oven at 50°C to constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:3 and a melt-blending temperature of 180℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 180℃, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0024] Example 3 This embodiment discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 5:3.6:4:6. The amount of toluene used is 5 times the sum of the masses of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 75°C. At ℃, a 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 3% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 2 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 75℃ for 20 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50℃ to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:20. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 45°C for 40 min to allow swelling. Under nitrogen protection, add glycidyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:20:4:3.5:2.7. Under nitrogen protection, react at 110°C with a stirring speed of 200 r / min for 1.5 h. After the reaction is complete, wash with acetone and filter, then dry in a vacuum drying oven at 50°C to constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:5 and a melt-blending temperature of 200℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 200℃, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0025] Example 4 This embodiment discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 3.5:2.4:2.5:4.5. The amount of toluene used is 5 times the sum of the masses of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 7°C. At 0℃, a 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 1.5% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1.5 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 70℃ for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50℃ to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:15. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 40°C for 50 min to allow swelling. Under nitrogen protection, add glycidyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:12:2.5:3:2.2. Under nitrogen protection, react at 150 r / min and 100°C for 2 h. After the reaction is complete, wash with acetone and filter. Dry in a 50°C vacuum drying oven to constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:3.5 and a melt-blending temperature of 190℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 190°C, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0026] Example 5 This embodiment discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 4:2.8:3:5. The amount of toluene used is 4 times the sum of the masses of dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 70℃. A 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 2% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1.5 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 70 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50 °C to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:15. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 40°C for 50 min to allow swelling. Under nitrogen protection, add glycidyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:15:3:3.15:2.4. Under nitrogen protection, react at 100°C with a stirring speed of 150 r / min for 2 h. After the reaction is complete, wash with acetone and filter. Dry in a vacuum drying oven at 50°C until constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:4 and a melt-blending temperature of 190℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 190°C, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0027] Example 6 This embodiment discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 4.5:3.2:3.5:5.5. The amount of toluene used is 4 times the sum of the masses of dodecylfluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 7°C. At 0℃, a 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 2.5% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1.5 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 70℃ for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50℃ to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:15. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 40°C for 50 min to allow swelling. Under nitrogen protection, add glycidyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:18:3.5:3.3:2.6. Under nitrogen protection, react at 150 r / min and 100°C for 2 h. After the reaction is complete, wash with acetone and filter. Dry in a 50°C vacuum drying oven to constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:4.5 and a melt-blending temperature of 190℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 190°C, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0028] Comparative Example 1 This comparative example discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 3:2:2:4. The amount of toluene used is 3 times the sum of the masses of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 65℃. A 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 1% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 65 °C for 28 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50 °C to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:10. Step 2: Melt-blend polypropylene with composite modifier. The mass ratio of grafted modified polypropylene to composite modifier is 100:3. The melt blending temperature is 180℃. Extrude, cool, and pelletize to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 180℃, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0029] Comparative Example 2 This comparative example discloses a method for preparing an automotive film with heat insulation and hydrophobic properties, including the following steps: Step 1: Add dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to toluene. The mass ratio of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 is 3:2:2:4. The amount of toluene used is 3 times the sum of the masses of dodecyl fluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and alkenyl-modified ATO / TiO2 to obtain a mixed monomer dispersion. Heat the mixed monomer dispersion to 65℃. A 2,2'-azobisisobutyronitrile solution was added dropwise. The content of 2,2'-azobisisobutyronitrile in the 2,2'-azobisisobutyronitrile solution was 1% of the total mass of dodecafluoroheptyl methacrylate, oleic acid, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and alkenyl-modified ATO / TiO2. The dropwise addition time of the 2,2'-azobisisobutyronitrile solution was 1 h. After the dropwise addition was completed, the reaction was carried out in a nitrogen atmosphere at 65 °C for 28 h. After the reaction was completed, the mixture was cooled to room temperature, and methanol was added to the reaction mixture to precipitate the precipitate. The amount of methanol added was until the precipitate no longer increased. The mixture was filtered, and the filter cake was washed three times with methanol and dried in a vacuum drying oven at 50 °C to constant weight to obtain the composite modifier. The 2,2'-azobisisobutyronitrile solution was prepared by mixing 2,2'-azobisisobutyronitrile and toluene at a mass ratio of 1:10. Step 2: Mix polypropylene, benzoyl peroxide, and xylene, and stir at 35°C for 60 min to allow swelling. Under nitrogen protection, add methyl methacrylate and styrene. The mass ratio of polypropylene, xylene, benzoyl peroxide, methyl methacrylate, and styrene is 100:10:2:2.8:2.1. Under nitrogen protection, react at 90°C with a stirring speed of 100 r / min for 2.5 h. After the reaction is complete, wash with acetone and filter, then dry in a vacuum drying oven at 50°C to constant weight to obtain grafted modified polypropylene. Graft-modified polypropylene and composite modifier are melt-blended at a mass ratio of 100:3 and a melt-blending temperature of 180℃. The mixture is then extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch at a melting temperature of 180℃, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties. Among them, biaxial stretching involves sequential longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 110℃ and the stretching ratio is 5 times. The transverse stretching temperature is 170℃ and the stretching ratio is 9 times. The thickness of the automotive film with heat insulation and hydrophobic properties is 70 μm.
[0030] In the above examples and comparative examples, the average particle size of the carbon microspheres was 200 nm; the polypropylene was a homopolymer polypropylene for biaxially oriented BOPP film, with a melt flow index (230℃ / 2.16kg) of 2.8 g / 10 min.
[0031] Test case The performance of the automotive films with heat-insulating and hydrophobic properties prepared in Examples 2-6 and Comparative Examples 1-2 was tested: (1) Infrared blocking performance: The infrared transmittance of the automotive film was determined according to the standard QC / T1170-2022 "Functional Films for Automotive Glass". The method for determining the infrared transmittance is as follows: in the near-infrared band of the solar spectrum, 780-1100nm, the ratio of the radiant flux reflected by the automotive film to the incident radiant flux is measured. The infrared blocking rate is calculated based on the infrared transmittance. Infrared blocking rate = 1 - infrared transmittance. The results of the infrared blocking rate measurement are shown in Table 1. Table 1
[0032] As shown in Table 1, the automotive film prepared by this invention has good infrared blocking performance, and thus excellent heat insulation performance. The introduction of ATO / TiO2 can effectively improve the infrared blocking performance of polypropylene. Furthermore, the alkenyl-modified ATO / TiO2 is linked with fluorinated monomers, oleic acid, and reactive ultraviolet absorbers through free radical polymerization, which can effectively avoid the problem of poor compatibility of ATO / TiO2 in the resin matrix. In addition, the carboxyl groups introduced by oleic acid on the composite modifier can undergo ring-opening reaction with the epoxy groups on the grafted modified polypropylene molecules, anchoring ATO / TiO2 in the polypropylene resin matrix network, further improving the infrared blocking performance of the modified polypropylene. Compared with Example 2, in Comparative Example 1, the compatibility between the unmodified polypropylene resin matrix and the composite modifier was poor, resulting in a decrease in the uniformity of ATO / TiO2 nanoparticle dispersion in the polypropylene resin matrix and a decrease in infrared blocking performance. In Comparative Example 2, the grafting monomer of polypropylene was replaced by methyl methacrylate instead of glycidyl methacrylate. Although the polarity of the polypropylene resin matrix was improved by grafting, it lacked chemical anchoring effect, and the uniformity of ATO / TiO2 nanoparticle dispersion in the polypropylene resin matrix also decreased, resulting in a decrease in infrared blocking performance.
[0033] (2) Ultraviolet blocking performance: The ultraviolet transmittance of the automotive film was determined according to the standard QC / T1170-2022 "Functional Films for Automotive Glass". The method for determining the ultraviolet transmittance is as follows: in the solar spectrum range of 300-380nm, the ratio of the luminous flux of the automotive film to the incident luminous flux is measured. The ultraviolet blocking rate is calculated based on the ultraviolet transmittance. The ultraviolet blocking rate = 1 - ultraviolet transmittance. The results of the ultraviolet blocking rate measurement are shown in Table 2. Table 2
[0034] As shown in Table 2, the automotive film prepared by this invention has good ultraviolet blocking performance, and thus excellent anti-ultraviolet aging performance and good weather resistance. The introduction of ultraviolet absorbers and ATO / TiO2 can effectively improve the anti-ultraviolet aging performance of polypropylene. Furthermore, the alkenyl-modified ATO / TiO2 is linked with fluorinated monomers, oleic acid, and reactive ultraviolet absorbers through free radical polymerization, which can effectively avoid the problem of poor compatibility of ATO / TiO2 in the resin matrix and the migration problem of organic ultraviolet absorbers in the resin matrix. In addition, the carboxyl groups introduced by oleic acid on the composite modifier can undergo ring-opening reaction with the epoxy groups on the grafted modified polypropylene molecules, anchoring the anti-ultraviolet aging components in the polypropylene resin matrix network, further improving the ultraviolet blocking performance of modified polypropylene. Compared with Example 2, in Comparative Example 1, the compatibility between the ungrafted polypropylene resin matrix and the composite modifier was poor, and the ultraviolet blocking performance decreased. In Comparative Example 2, the grafting monomer of polypropylene was replaced by glycidyl methacrylate with methyl methacrylate. Although the polarity of the polypropylene resin matrix was improved by grafting, it lacked chemical anchoring effect, and the ultraviolet blocking performance also decreased.
[0035] (3) Hydrophobic properties: The water contact angle of the automotive film was determined according to the standard GB / T30693-2014 "Measurement of the contact angle between plastic film and water". The results are shown in Table 3. Table 3
[0036] As shown in Table 3, the automotive film prepared by this invention has good hydrophobic properties. The introduction of hydrophobic substances, including fluorinated monomers and oleic acid, into the composite modifier can effectively improve the hydrophobic properties of polypropylene. Compared with Example 2, in Comparative Example 1, the compatibility between the unmodified polypropylene resin matrix and the composite modifier is poor, resulting in a decrease in hydrophobic properties; in Comparative Example 2, the grafting monomer of polypropylene was replaced by methyl methacrylate instead of glycidyl methacrylate. Although the polarity of the polypropylene resin matrix was improved through grafting, the lack of chemical anchoring effect also led to a decrease in hydrophobic properties.
[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing an automotive film with heat insulation and hydrophobic properties, characterized in that, Includes the following steps: Step 1: A composite modifier is prepared by reacting fluorinated monomers, oleic acid, reactive ultraviolet absorbers, and alkenyl-modified ATO / TiO2. Step 2: Polypropylene reacts with glycidyl methacrylate and styrene to obtain grafted modified polypropylene; the grafted modified polypropylene is melt-blended with a composite modifier, extruded, cooled, and pelletized to obtain modified polypropylene masterbatch. Step 3: Melt the modified polypropylene masterbatch, extrude it to obtain a film, and then biaxially stretch the film to obtain an automotive film with heat insulation and hydrophobic properties.
2. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 1, characterized in that, In step one, the preparation method of the composite modifier specifically includes: adding fluorinated monomer, oleic acid, reactive ultraviolet absorber and alkenyl modified ATO / TiO2 into toluene to obtain a mixed monomer dispersion; heating the mixed monomer dispersion to a set temperature; adding an initiator solution dropwise; reacting after the addition is complete; separating and purifying after the reaction is complete; and drying to obtain the composite modifier.
3. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 2, characterized in that, The mass ratio of fluorinated monomer, oleic acid, reactive UV absorber, and alkenyl-modified ATO / TiO2 is (3-5):(2-3.6):(2-4):(4-6); the amount of toluene is 3-5 times the total mass of fluorinated monomer, oleic acid, reactive UV absorber, and alkenyl-modified ATO / TiO2; the initiator content in the initiator solution is 1%-3% of the total mass of fluorinated monomer, oleic acid, reactive UV absorber, and alkenyl-modified ATO / TiO2; the reaction conditions are: reaction in a nitrogen atmosphere at a set temperature for 20-28 hours; the set temperature is 65-75℃.
4. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 3, characterized in that, The fluorinated monomer includes dodecafluoroheptyl methacrylate, the reactive ultraviolet absorber includes 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and the initiator solution includes 2,2'-azobisisobutyronitrile solution.
5. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 3, characterized in that, The alkenyl-modified ATO / TiO2 is prepared by the following steps: Step (1): Dissolve tin chloride pentahydrate and antimony chloride in deionized water, add carbon microspheres, disperse by ultrasonication, adjust the pH to 8-9, react, filter, wash, dry, and calcine to obtain ATO; Step (2): Dissolve titanium tetrachloride in deionized water, add ATO, adjust the pH to 7, react, filter, wash, and dry to obtain ATO / TiO2. Step (3): Add ATO / TiO2 and γ-methacryloxypropyltrimethoxysilane to an ethanol aqueous solution, disperse by ultrasonication, adjust the pH value to 3-5, and react. After the reaction is completed, filter, wash, and dry to obtain alkenyl-modified ATO / TiO2.
6. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 5, characterized in that, In step (1), the mass ratio of tin chloride pentahydrate, antimony chloride, deionized water, and carbon microspheres is (24-30):(1.8-2.2):(60-80):(1-1.4), the reaction conditions are 6-8 h at 30-40℃, and the calcination conditions are 1-2 h at 500-600℃; in step (2), the mass ratio of titanium tetrachloride, ATO, and deionized water is (8-10):10:(400-600), the reaction conditions are 6-8 h at 70-80℃; in step (3), the mass ratio of ATO / TiO2, γ-methacryloyloxypropyltrimethoxysilane, and aqueous ethanol solution is 10:(15-20):(300-400), the reaction conditions are 8-12 h at 70-80℃.
7. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 1, characterized in that, The preparation method of grafted modified polypropylene in step two specifically includes: Polypropylene, benzoyl peroxide and xylene were mixed and swollen. Under nitrogen protection, glycidyl methacrylate and styrene were added and reacted. After the reaction was completed, the mixture was purified to obtain grafted modified polypropylene. The mass ratio of polypropylene, xylene, benzoyl peroxide, glycidyl methacrylate, and styrene is 100:(10-20):(2-4):(2.8-3.5):(2.1-2.7). The swelling conditions are stirring at 35-45℃ for 40-60 min and reaction conditions are reacting at 90-110℃ for 1.5-2.5 h under nitrogen protection, at a stirring speed of 100-200 r / min.
8. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 1, characterized in that, In step two, when preparing the modified polypropylene masterbatch, the mass ratio of grafted modified polypropylene to composite modifier is 100:(3-5), and the melt blending temperature is 180-200℃.
9. The method for preparing an automotive film with heat insulation and hydrophobic properties according to claim 1, characterized in that, In step three, the melting temperature is 180-200℃, and the biaxial stretching is performed sequentially in the longitudinal and transverse directions. The longitudinal stretching temperature is 100-120℃, and the stretching ratio is 4-6 times. The transverse stretching temperature is 160-180℃, and the stretching ratio is 8-10 times.
10. An automotive film with heat insulation and hydrophobic properties prepared by the method for preparing an automotive film with heat insulation and hydrophobic properties as described in any one of claims 1-9.