Mildew-proof antibacterial vehicle window film and preparation method thereof

Abstract

The invention discloses a mildew-proof antibacterial vehicle window film and a preparation method thereof, and relates to the field of plastic films. When the mildew-proof and antibacterial vehicle window film is prepared, polypropylene sequentially reacts with 4-pentenoyl chloride, 2-mercaptobenzimidazole and 2-bromomethyl furan, and functional polypropylene is prepared; the preparation method comprises the following steps: reacting 3-dibutylaminopropylamine with maleic anhydride and diethyl 2-bromoethyl phosphonate in sequence, and polymerizing with dimethyl terephthalate and ethylene glycol to prepare modified polyester; and mixing the modified polyester and the functionalized polypropylene, and preparing a film, thereby obtaining the mildew-proof and antibacterial vehicle window film. The mildew-proof and antibacterial vehicle window film prepared by the invention has the capabilities of durability, self-repairing and flame retardance.

Description

Technical Field

[0001] The invention relates to the field of plastic films, in particular to a mildew-proof and antibacterial vehicle window film and a preparation method thereof. Background Art

[0002] Window film is a functional film that is pasted on the surface of automobile glass. It is mainly divided into three categories: tinted film, metal film and ceramic film. Metal film is mainly composed of aluminum / silver-plated reflective layer; ceramic film is mainly a non-metallic coating of nano-ceramic particles; tinted film is mainly an organic dye coating; it has functions such as heat insulation and sun protection, UV protection, safety and explosion protection, and privacy protection.

[0003] There are a large number of microorganisms in daily life, and microbial metabolites will produce odors, especially in humid environments, which will lead to a decrease in the air quality in the car and affect comfort. Microbial growth may even corrode the glue layer, reduce the adhesion of the film, affect the explosion-proof performance during a collision, and increase the risk of glass fragments flying. Therefore, this application introduces an anti-mildew and antibacterial car window film and its preparation method. Summary of the Invention

[0004] The object of the present invention is to provide a mildew-proof and antibacterial vehicle window film and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] A mildew-proof and antibacterial vehicle window film, which is prepared by mixing modified polyester and functionalized polypropylene to form a film; The modified polyester is prepared by reacting 3-dibutylaminopropylamine with maleic anhydride and diethyl 2-bromoethylphosphonate in sequence and then polymerizing it with dimethyl terephthalate and ethylene glycol; The functionalized polypropylene is prepared by sequentially reacting polypropylene with 4-pentenoyl chloride, 2-mercaptobenzimidazole and 2-bromomethylfuran.

[0006] A method for preparing a mildew-proof and antibacterial vehicle window film, the method mainly comprising the following preparation steps: (1) 2-Bromomethylfuran, propanol and modified polypropylene were mixed in a mass ratio of 1:18~22:12~14, stirred at 88~92℃ and 200~300r / min for 8~10min, 0.32~0.34 times the volume of propanol of ethylenediamine was added, and the mixture was stirred for 11~13h. The mixture was poured into deionized water, allowed to stand for 25~35min, filtered, washed with deionized water for 3~5 times, vacuum dried at 45~55℃ for 11~13h, and crushed to a diameter of 2~3mm to obtain functionalized polypropylene. (2) Dimethyl terephthalate, ethylene glycol and flame retardant monomer are mixed in a molar ratio of 7-9:9-11:1.5-2.5, stirred at 180-190°C and 200-300 r / min for 2-3 hours, antimony trioxide (0.3-0.4 times the mass of ethylene glycol) is added, the temperature is raised to 250-270°C, stirring is continued for 1.5-2.5 hours, cooled to room temperature, and crushed to a diameter of 2-3 mm to obtain modified polyester; (3) The modified polyester and functionalized polypropylene were mixed in a mass ratio of 1:1, heated to 265-275°C, stirred at 200-300 r / min for 12-14 min, and extruded using a twin-screw extruder with the temperatures of each section at 275°C, 295°C, 305°C, 310°C, and 315°C, the die head at 310°C, and the screw speed at 8 Hz. The mixture was placed in water, cooled to room temperature, crushed to a diameter of 2-3 mm, vacuum dried at 75-85°C for 2-3 h, placed in a hot press mold at 280-290°C, pressed into a film with a thickness of 0.038-0.04 mm, taken out, and cooled to room temperature in a cold press to obtain a car window film.

[0007] As an optimization, the modified polypropylene in step (1) is prepared by uniformly mixing 2-mercaptobenzimidazole, tetrahydrofuran and triethylamine in a molar ratio of 1:7.6~8:1.18~1.22 to obtain a 2-mercaptobenzimidazole mixed solution; the pre-modified polypropylene and tetrahydrofuran are mixed in a mass ratio of 1:4~5, and 1.8~2.2 times the mass of the pre-modified polypropylene is added at a uniform rate within 8~10 minutes at 200~300 r / min, 0~4°C, and under nitrogen protection. The mixture is heated to 45~55°C, stirred for 5.5~6.5 hours, filtered, washed with tetrahydrofuran 3~5 times, and vacuum dried at -10~0°C for 22~26 hours.

[0008] As an optimization, the pre-modified polypropylene is prepared by heating polypropylene with a degree of polymerization of 600 to 178-182° C. and stirring at 40-60 r / min for 6-8 minutes to obtain a polypropylene melt; the polypropylene melt, 4-pentenoyl chloride, and styrene are mixed in a mass ratio of 8-10:1:0.09-0.11, and stirring is continued at 178-182° C. for 8-10 minutes, and dicumyl peroxide (0.002-0.003 times the mass of the polypropylene melt) is added, stirring is continued for 12-14 minutes, cooling to room temperature, and crushing to a particle size of 2-3 mm.

[0009] As an optimization, the flame retardant monomer in step (2) is prepared by mixing diethyl 2-bromoethylphosphonate, a functionalized monomer and N,N-dimethylethanolamine in a molar ratio of 1.4-1.6:1.4-1.6:1, stirring at 55-65°C and 200-300 r / min for 25-35 min, adding a mixed solvent with a mass of 14-16 times that of diethyl 2-bromoethylphosphonate, continuing stirring for 11.5-12.5 h, cooling to room temperature, and vacuum drying at -10-0°C for 28-32 h.

[0010] As an optimization, the functionalized monomer is prepared by mixing 3-dibutylaminopropylamine, maleic anhydride, and N,N-dimethylformamide in a molar ratio of 1:1:12-16, stirring for 25-35 minutes at 200-300 r / min, 85-95° C., and under nitrogen protection, adding nickel acetate tetrahydrate (0.03-0.05 times the mass of 3-dibutylaminopropylamine), triethylamine (0.009-0.011 times the volume of N,N-dimethylformamide), and acetic anhydride (0.38-0.42 times the volume of N,N-dimethylformamide), continuing stirring for 35-45 minutes, cooling to room temperature, pouring into deionized water at 0-4° C., stirring at 200-300 r / min for 11-13 hours, filtering, washing with deionized water 3-5 times, and drying at 75-85° C. for 12-14 hours.

[0011] As an optimization, the mixed solvent is prepared by uniformly mixing methanol and propanol in a volume ratio of 1:4.5~5.5.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are: When preparing the mildew-proof and antibacterial vehicle window film, the present invention comprises the following steps: reacting polypropylene with 4-pentenoyl chloride, 2-mercaptobenzimidazole and 2-bromomethylfuran in sequence to obtain functionalized polypropylene; reacting 3-dibutylaminopropylamine with maleic anhydride and diethyl 2-bromoethylphosphonate in sequence, and then polymerizing the mixture with dimethyl terephthalate and ethylene glycol to obtain modified polyester; and mixing the modified polyester with the functionalized polypropylene to form a film to obtain the mildew-proof and antibacterial vehicle window film.

[0013] First, polypropylene is reacted with 4-pentenoyl chloride, 2-mercaptobenzimidazole and 2-bromomethylfuran in sequence. 4-pentenoyl chloride is grafted onto polypropylene through an initiator, and then reacted with 2-mercaptobenzimidazole. Through the reaction of the thiol group and the acyl chloride, a thiol ester compound is synthesized on the benzimidazole molecular skeleton. The lone pair electrons of the sulfur atom are used to reduce the rigid structure of the phenylbenzoazole, improve the structural stability, and give the material long-term aging resistance. Then, it reacts with 2-bromomethylfuran to introduce furan groups on the surface of polypropylene, which can undergo a DA reaction with the maleimide structure on the polyester. When the window film is damaged, the DA reaction is used to restore its integrity, thereby achieving a self-repair effect.

[0014] Secondly, 3-dibutylaminopropylamine is reacted with maleic anhydride and diethyl 2-bromoethylphosphonate in sequence, and then polymerized with dimethyl terephthalate and ethylene glycol to obtain a modified polyester; the modified polyester is mixed with functionalized polypropylene to form a film to obtain a mildew-proof and antibacterial window film; 3-dibutylaminopropylamine is reacted with maleic anhydride in sequence to form a maleimide structure, and then reacted with diethyl 2-bromoethylphosphonate to introduce organic phosphorus into the polyester material, which absorbs a large amount of heat during the decomposition process, thereby reducing the surface temperature of the material and increasing the ignition temperature. In addition, it can also prevent Carbon monoxide is oxidized to carbon dioxide, further reducing heat release during combustion. Organic phosphorus can decompose to produce PO· free radicals, which can effectively capture H·, thereby reducing the concentration of hydrogen atoms, further inhibiting the combustion reaction, and improving the flame retardancy of the material. At the same time, quaternary ammonium salts are formed, which can be adsorbed onto the surface of bacteria. The hydrophobic base is inserted into the lipid layer, changing the permeability of the cell membrane, destroying the membrane structure, causing the leakage of intracellular substances, denaturing enzymes or proteins, inhibiting the activity of enzymes or proteins, affecting the cell metabolism process, and finally causing the death of the bacteria, achieving an antibacterial effect. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0016] Example 1: A method for preparing a mildew-proof and antibacterial window film, comprising the following steps: (1) Polypropylene with a degree of polymerization of 600 was heated to 178°C and stirred at 40 r / min for 6 minutes to obtain a polypropylene melt; polypropylene melt, 4-pentenoyl chloride, and styrene were mixed in a mass ratio of 8:1:0.09 and stirred at 178°C for 8 minutes, and dicumyl peroxide (0.002 times the mass of the polypropylene melt) was added and stirred for 12 minutes. The mixture was cooled to room temperature and crushed to a particle size of 2 mm to obtain pre-modified polypropylene; 2-mercaptobenzimidazole, tetrahydrofuran, and triethylamine were mixed uniformly in a molar ratio of 1:7.6:1.18 to prepare a 2-mercaptobenzimidazole mixed solution; pre-modified polypropylene and tetrahydrofuran were mixed in a mass ratio of 1:4, and 1.8 times the mass of the pre-modified polypropylene was added to the mixture at a constant rate of 200 r / min, 0°C, and nitrogen protection within 8 minutes. The mixture was heated to 45°C and stirred for 5.5 hours. The mixture was filtered, washed with tetrahydrofuran three times, and vacuum dried at -10°C for 22 hours to prepare modified polypropylene. 2-Bromomethylfuran, propanol and modified polypropylene were mixed in a mass ratio of 1:18:12, stirred at 88°C and 200 r / min for 8 minutes, ethylenediamine (0.32 times the volume of propanol) was added, and stirring was continued for 11 hours. The mixture was poured into deionized water, allowed to stand for 25 minutes, filtered, washed with deionized water three times, dried in vacuum at 45°C for 11 hours, and crushed to a diameter of 2 mm to obtain functionalized polypropylene. (2) 3-dibutylaminopropylamine, maleic anhydride and N,N-dimethylformamide were mixed in a molar ratio of 1:1:12, stirred at 200 r / min, 85 ° C, and nitrogen protection for 25 min, and nickel acetate tetrahydrate (0.03 times the mass of 3-dibutylaminopropylamine), triethylamine (0.009 times the volume of N,N-dimethylformamide) and acetic anhydride (0.38 times the volume of N,N-dimethylformamide) were added, and the mixture was stirred for 35 min. After cooling to room temperature, the mixture was poured into deionized water at 0 ° C, stirred at 200 r / min for 11 h, filtered, washed with deionized water 3 times, and dried at 75 ° C for 12 h to obtain a functionalized monomer. Methanol and propanol were mixed uniformly in a volume ratio of 1:4.5 to prepare a mixed solvent; diethyl 2-bromoethylphosphonate, a functional monomer and N,N-dimethylethanolamine were mixed in a molar ratio of 1.4:1.4:1, stirred at 55°C and 200 r / min for 25 minutes, and a mixed solvent 14 times the mass of diethyl 2-bromoethylphosphonate was added, and stirring was continued for 11.5 hours. The mixture was cooled to room temperature and vacuum dried at -10°C for 28 hours to prepare a flame retardant monomer. Dimethyl terephthalate, ethylene glycol and flame retardant monomer were mixed in a molar ratio of 7:9:1.5, stirred at 180°C and 200 r / min for 2 h, antimony trioxide (0.3 times the mass of ethylene glycol) was added, the temperature was raised to 250°C, stirring was continued for 1.5 h, cooled to room temperature, and crushed to a diameter of 2 mm to obtain a modified polyester; (3) The modified polyester and functionalized polypropylene were mixed in a mass ratio of 1:1, heated to 265°C, stirred at 200 r / min for 12 min, and extruded using a twin-screw extruder with the temperatures of each section set at 275°C, 295°C, 305°C, 310°C, and 315°C, the die head at 310°C, and the screw speed at 8 Hz. The mixture was placed in water, cooled to room temperature, crushed to a diameter of 2 mm, vacuum-dried at 75°C for 2 h, and placed in a hot press mold at 280°C to be pressed into a film with a thickness of 0.038 mm. The film was taken out and cooled to room temperature in a cold press to obtain a car window film.

[0017] Example 2: A method for preparing a mildew-proof and antibacterial window film, comprising the following steps: (1) Polypropylene with a degree of polymerization of 600 was heated to 180°C and stirred at 50 r / min for 7 minutes to obtain a polypropylene melt; polypropylene melt, 4-pentenoyl chloride, and styrene were mixed in a mass ratio of 9:1:0.1 and stirred at 180°C for 9 minutes, and dicumyl peroxide (0.0025 times the mass of the polypropylene melt) was added and stirred for 13 minutes. The mixture was cooled to room temperature and crushed to a particle size of 2.5 mm to obtain pre-modified polypropylene; 2-mercaptobenzimidazole, tetrahydrofuran, and triethylamine were mixed uniformly in a molar ratio of 1:7.8:1.2 to prepare a 2-mercaptobenzimidazole mixed solution; pre-modified polypropylene and tetrahydrofuran were mixed in a mass ratio of 1:4.5, and 2-mercaptobenzimidazole mixed solution twice the mass of pre-modified polypropylene was added at a constant rate of 250 r / min, 2°C, and nitrogen protection within 9 minutes. The temperature was raised to 50°C, and stirring was continued for 6 hours. The mixture was filtered, washed with tetrahydrofuran 4 times, and vacuum dried at -5°C for 24 hours to prepare modified polypropylene. 2-Bromomethylfuran, propanol and modified polypropylene were mixed in a mass ratio of 1:20:13, stirred at 90°C and 250 r / min for 9 minutes, ethylenediamine (0.33 times the volume of propanol) was added, and stirring was continued for 12 hours. The mixture was poured into deionized water, allowed to stand for 30 minutes, filtered, washed with deionized water four times, dried in vacuum at 50°C for 12 hours, and crushed to a diameter of 2.5 mm to obtain functionalized polypropylene. (2) 3-dibutylaminopropylamine, maleic anhydride and N,N-dimethylformamide were mixed in a molar ratio of 1:1:14, stirred at 250 r / min, 90 ° C under nitrogen protection for 30 min, and nickel acetate tetrahydrate (0.04 times the mass of 3-dibutylaminopropylamine), triethylamine (0.01 times the volume of N,N-dimethylformamide) and acetic anhydride (0.4 times the volume of N,N-dimethylformamide) were added, and the mixture was stirred for 40 min. After cooling to room temperature, the mixture was poured into deionized water at 2 ° C, stirred at 250 r / min for 12 h, filtered, washed with deionized water 4 times, and dried at 80 ° C for 13 h to obtain a functionalized monomer. Methanol and propanol were mixed evenly in a volume ratio of 1:5 to prepare a mixed solvent; diethyl 2-bromoethylphosphonate, a functional monomer and N,N-dimethylethanolamine were mixed in a molar ratio of 1.5:1.5:1, stirred at 60°C and 250 r / min for 30 minutes, and a mixed solvent 15 times the mass of diethyl 2-bromoethylphosphonate was added, and stirring was continued for 12 hours. The mixture was cooled to room temperature and vacuum dried at -5°C for 30 hours to prepare a flame retardant monomer. Dimethyl terephthalate, ethylene glycol and flame retardant monomer were mixed in a molar ratio of 8:10:2, stirred at 185°C and 250 r / min for 2.5 hours, antimony trioxide (0.35 times the mass of ethylene glycol) was added, the temperature was raised to 260°C, stirring was continued for 2 hours, cooled to room temperature, and crushed to a diameter of 2.5 mm to obtain a modified polyester; (3) The modified polyester and functionalized polypropylene were mixed in a mass ratio of 1:1, heated to 270°C, stirred at 250 r / min for 13 min, and extruded using a twin-screw extruder. The temperatures of each section were 275°C, 295°C, 305°C, 310°C, and 315°C, the die head was 310°C, and the screw speed was 8 Hz. The mixture was placed in water, cooled to room temperature, crushed to a diameter of 2.5 mm, vacuum dried at 80°C for 2.5 h, placed in a hot press mold at 285°C, pressed into a film with a thickness of 0.039 mm, taken out, and cooled to room temperature in a cold press to obtain a car window film.

[0018] Example 3: A method for preparing a mildew-proof and antibacterial window film, comprising the following steps: (1) Polypropylene with a degree of polymerization of 600 was heated to 182°C and stirred at 60 r / min for 8 minutes to obtain a polypropylene melt; polypropylene melt, 4-pentenoyl chloride, and styrene were mixed in a mass ratio of 10:1:0.11 and stirred at 182°C for 10 minutes, and dicumyl peroxide (0.003 times the mass of the polypropylene melt) was added and stirred for 14 minutes. The mixture was cooled to room temperature and crushed to a particle size of 3 mm to obtain pre-modified polypropylene; 2-mercaptobenzimidazole, tetrahydrofuran, and triethylamine were mixed uniformly in a molar ratio of 1:8:1.22 to prepare a 2-mercaptobenzimidazole mixed solution; pre-modified polypropylene and tetrahydrofuran were mixed in a mass ratio of 1:5, and 2-mercaptobenzimidazole mixed solution (2.2 times the mass of pre-modified polypropylene) was added uniformly at 300 r / min, 4°C, and nitrogen protection within 10 minutes. The temperature was raised to 55°C, and stirring was continued for 6.5 hours. The mixture was filtered, washed with tetrahydrofuran 5 times, and vacuum dried at 0°C for 26 hours to prepare modified polypropylene. 2-Bromomethylfuran, propanol and modified polypropylene were mixed in a mass ratio of 1:22:14, stirred at 92°C and 300 r / min for 10 min, ethylenediamine (0.34 times the volume of propanol) was added, and stirring was continued for 13 h. The mixture was poured into deionized water, allowed to stand for 35 min, filtered, washed with deionized water 5 times, dried in vacuum at 55°C for 13 h, and crushed to a diameter of 3 mm to obtain functionalized polypropylene. (2) 3-dibutylaminopropylamine, maleic anhydride and N,N-dimethylformamide were mixed in a molar ratio of 1:1:16, stirred at 300 r / min, 95 ° C under nitrogen protection for 35 min, and nickel acetate tetrahydrate (0.05 times the mass of 3-dibutylaminopropylamine), triethylamine (0.011 times the volume of N,N-dimethylformamide) and acetic anhydride (0.42 times the volume of N,N-dimethylformamide) were added, and the mixture was stirred for 45 min. After cooling to room temperature, the mixture was poured into deionized water at 4 ° C, stirred at 300 r / min for 13 h, filtered, washed with deionized water 5 times, and dried at 85 ° C for 14 h to obtain a functionalized monomer. Methanol and propanol were mixed uniformly in a volume ratio of 1:5.5 to prepare a mixed solvent; diethyl 2-bromoethylphosphonate, a functional monomer and N,N-dimethylethanolamine were mixed in a molar ratio of 1.6:1.6:1, stirred at 65°C and 300 r / min for 35 minutes, and a mixed solvent 16 times the mass of diethyl 2-bromoethylphosphonate was added, and stirring was continued for 12.5 hours. The mixture was cooled to room temperature and vacuum dried at 0°C for 32 hours to prepare a flame retardant monomer. Dimethyl terephthalate, ethylene glycol and flame retardant monomer were mixed in a molar ratio of 9:11:2.5, stirred at 190°C and 300 r / min for 3 hours, antimony trioxide (0.4 times the mass of ethylene glycol) was added, the temperature was raised to 270°C, stirring was continued for 2.5 hours, cooled to room temperature, and crushed to a diameter of 3 mm to obtain a modified polyester; (3) The modified polyester and functionalized polypropylene were mixed in a mass ratio of 1:1, heated to 275°C, stirred at 300 r / min for 14 min, and extruded using a twin-screw extruder with the temperatures of each section set at 275°C, 295°C, 305°C, 310°C, and 315°C, the die head at 310°C, and the screw speed at 8 Hz. The mixture was placed in water, cooled to room temperature, crushed to a diameter of 3 mm, vacuum dried at 85°C for 3 h, placed in a hot press mold at 290°C, pressed into a film with a thickness of 0.04 mm, taken out, and cooled to room temperature in a cold press to obtain a car window film.

[0019] Comparative Example 1: The difference between the preparation method of the mildew-proof and antibacterial window film of Comparative Example 1 and Example 2 lies in the difference in step (1). Step (1) is modified as follows: polypropylene with a degree of polymerization of 600 is heated to 180°C and stirred at 50r / min for 7min to obtain a polypropylene melt; polypropylene melt, 4-pentenoyl chloride and styrene are mixed in a mass ratio of 9:1:0.1, and stirred at 180°C for 9min, diisopropylbenzene peroxide (0.0025 times the mass of the polypropylene melt) is added, and stirring is continued for 13min, cooled to room temperature, and crushed to a particle size of 2 0.5mm to prepare pre-modified polypropylene; 2-mercaptobenzimidazole, tetrahydrofuran, and triethylamine were mixed uniformly in a molar ratio of 1:7.8:1.2 to prepare a 2-mercaptobenzimidazole mixed solution; the pre-modified polypropylene and tetrahydrofuran were mixed in a mass ratio of 1:4.5, and the 2-mercaptobenzimidazole mixed solution (twice the mass of the pre-modified polypropylene) was added at a constant rate of 250 rpm, 2°C, and nitrogen protection over 9 minutes. The temperature was raised to 50°C, and stirring was continued for 6 hours. The mixture was filtered, washed with tetrahydrofuran four times, and vacuum dried at -5°C for 24 hours to prepare functionalized polypropylene. The remaining steps were the same as in Example 2.

[0020] Comparative Example 2: The preparation method of the mildew-proof and antibacterial window film of Comparative Example 2 differs from that of Example 2 only in that the polypropylene is not modified. The remaining steps are the same as those of Example 2.

[0021] Comparative Example 3: The method for preparing the mildew-proof and antibacterial window film of Comparative Example 3 differs from that of Example 2 in step (2). Step (2) is modified as follows: dimethyl terephthalate, ethylene glycol, and diethyl 1-propylphosphonate are mixed in a molar ratio of 8:10:2, stirred at 185°C and 250 r / min for 2.5 h, antimony trioxide (0.35 times the mass of ethylene glycol) is added, the temperature is raised to 260°C, stirring is continued for 2 h, the mixture is cooled to room temperature, and the mixture is crushed to a diameter of 2.5 mm to obtain a modified polyester. The remaining steps are the same as those of Example 2.

[0022] Comparative Example 4: The method for preparing the mildew-proof and antibacterial window film of Comparative Example 4 differs from that of Example 2 in step (2). Step (2) is modified as follows: dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 10:10, stirred at 185°C and 250 r / min for 2.5 h, antimony trioxide (0.35 times the mass of ethylene glycol) is added, the temperature is raised to 260°C, stirring is continued for 2 h, the mixture is cooled to room temperature, and the mixture is crushed to a diameter of 2.5 mm to obtain a modified polyester. The remaining steps are the same as those of Example 2.

[0023] Test Example 1: Antibacterial Test Antibacterial test method: The antibacterial rate of the window film prepared in each embodiment and comparative example was tested according to the GB / T31402-2015 test standard, wherein the selected bacterial species were Staphylococcus aureus and Escherichia coli; Flame retardant test method: The limiting oxygen index of the window films prepared in each embodiment and comparative example was tested according to the GBT / 2406 test standard. The results are shown in Table 1: From the comparison of the experimental data in Table 1, it can be found that the mildew-proof and antibacterial window film prepared by the present invention has good antibacterial and flame-retardant capabilities.

[0024] From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 3 in Table 1, it can be found that the antibacterial rates of Examples 1, 2, and 3 are high. The difference between Comparative Example 3 and the Example is that no quaternary ammonium salt is formed by the reaction of diethyl 2-bromoethylphosphonate with a functionalized monomer, which shows that the quaternary ammonium salt can be adsorbed to the surface of the bacteria, and the hydrophobic group is inserted into the lipid layer, changing the permeability of the cell membrane, destroying the membrane structure, causing the leakage of intracellular substances, denaturation of enzymes or proteins, inhibition of enzyme or protein activity, affecting the cell metabolic process, and finally inducing bacterial death, thereby achieving an antibacterial effect; Comparison of the experimental data of Examples 1, 2, and 3 with Comparative Example 4 shows that Examples 1, 2, and 3 have high antibacterial rates. The difference between Comparative Example 4 and the Examples is that no organophosphorus is introduced. This indicates that organophosphorus absorbs a large amount of heat during the decomposition process, thereby lowering the surface temperature of the material and increasing the ignition temperature. In addition, it can prevent carbon monoxide from being oxidized to carbon dioxide, further reducing heat release during combustion. Furthermore, organophosphorus can decompose to produce PO· free radicals, which can effectively capture H·, thereby reducing the concentration of hydrogen atoms, further inhibiting the combustion reaction, and improving the flame retardancy of the material.

[0025] Test Example 2: Aging resistance and self-repair test Aging resistance test method: 10 cm long and 2 cm wide strips of the window film prepared in each embodiment and comparative example were tested for tensile strength, which was recorded as M0. After 12 days of irradiation with a fluorescent ultraviolet lamp UV-A340, the tensile strength was again tested, which was recorded as M1. The retention rate was calculated, where the retention rate = M1 / M0 × 100%; Self-repair test method: 10 cm long and 2 cm wide strips of window film prepared in each example and comparative example were tested for tensile strength, recorded as M0. A small cut 1 cm long and 0.02 mm deep was made horizontally on the strip surface. The strip was left at 60°C for 4 hours and then tested for tensile strength again, recorded as M2. The retention rate ' was calculated, where retention rate ' = M2 / M0 × 100%. The results are shown in Table 2: From the comparison of the experimental data in Table 2, it can be found that the mildew-proof and antibacterial window film prepared by the present invention has good aging resistance and self-repairing ability.

[0026] From the comparison of the experimental data of Examples 1, 2, and 3 and Comparative Example 1 in Table 2, it can be found that the retention rates of Examples 1, 2, and 3 are large. The difference between Comparative Example 1 and the Example is that no furan structure is introduced on the surface of the polypropylene, which shows that the furan group can react with the maleimide structure on the polyester to undergo a DA reaction. When the window film is damaged, the DA reaction can be used to restore its integrity, thereby achieving a self-repairing effect. From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 2, it can be found that the retention rates of Examples 1, 2, and 3 are large. The difference between Comparative Example 2 and the Example is that no ultraviolet absorption structure is formed on the polypropylene surface. This shows that through the reaction of thiol groups with acyl chlorides, thiol ester compounds can be synthesized on the benzimidazole molecular skeleton, and the lone pair electrons of the sulfur atom are used to reduce the rigid structure of the phenylbenzoxazole, improve the stability of the structure, and enable the material to obtain long-term aging resistance.

[0027] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mildew-proof and antibacterial window film, characterized in that: The mildew-proof and antibacterial window film is prepared by mixing modified polyester and functionalized polypropylene to form a film; The modified polyester is prepared by reacting 3-dibutylaminopropylamine with maleic anhydride and diethyl 2-bromoethylphosphonate in sequence and then polymerizing it with dimethyl terephthalate and ethylene glycol; The functionalized polypropylene is prepared by sequentially reacting polypropylene with 4-pentenoyl chloride, 2-mercaptobenzimidazole and 2-bromomethylfuran.

2. A method for preparing a mildew-proof and antibacterial vehicle window film, characterized in that: The preparation method of the mildew-proof and antibacterial window film mainly comprises the following preparation steps: (1) 2-Bromomethylfuran, propanol and modified polypropylene were mixed in a mass ratio of 1:18~22:12~14, stirred at 88~92℃ and 200~300r / min for 8~10min, 0.32~0.34 times the volume of propanol of ethylenediamine was added, and the mixture was stirred for 11~13h. The mixture was poured into deionized water, allowed to stand for 25~35min, filtered, washed with deionized water for 3~5 times, vacuum dried at 45~55℃ for 11~13h, and crushed to a diameter of 2~3mm to obtain functionalized polypropylene. (2) Dimethyl terephthalate, ethylene glycol and flame retardant monomer are mixed in a molar ratio of 7-9:9-11:1.5-2.5, stirred at 180-190°C and 200-300 r / min for 2-3 hours, antimony trioxide (0.3-0.4 times the mass of ethylene glycol) is added, the temperature is raised to 250-270°C, stirring is continued for 1.5-2.5 hours, cooled to room temperature, and crushed to a diameter of 2-3 mm to obtain modified polyester; (3) The modified polyester and functionalized polypropylene were mixed in a mass ratio of 1:1, heated to 265-275°C, stirred at 200-300 r / min for 12-14 min, and extruded using a twin-screw extruder with the temperatures of each section at 275°C, 295°C, 305°C, 310°C, and 315°C, the die head at 310°C, and the screw speed at 8 Hz. The mixture was placed in water, cooled to room temperature, crushed to a diameter of 2-3 mm, vacuum dried at 75-85°C for 2-3 h, placed in a hot press mold at 280-290°C, pressed into a film with a thickness of 0.038-0.04 mm, taken out, and cooled to room temperature in a cold press to obtain a car window film.

3. The method for preparing a mildew-proof and antibacterial vehicle window film according to claim 2, characterized in that: The modified polypropylene in step (1) is prepared by uniformly mixing 2-mercaptobenzimidazole, tetrahydrofuran and triethylamine in a molar ratio of 1:7.6~8:1.18~1.22 to obtain a 2-mercaptobenzimidazole mixed solution; the pre-modified polypropylene and tetrahydrofuran are mixed in a mass ratio of 1:4~5, and the 2-mercaptobenzimidazole mixed solution in an amount of 1.8~2.2 times the mass of the pre-modified polypropylene is added at a uniform rate within 8~10 minutes at 200~300 r / min, 0~4°C and nitrogen protection, and the mixture is heated to 45~55°C, stirred for 5.5~6.5 hours, filtered, washed with tetrahydrofuran for 3~5 times, and vacuum dried at -10~0°C for 22~26 hours.

4. The method for preparing a mildew-proof and antibacterial vehicle window film according to claim 3, characterized in that: The pre-modified polypropylene is prepared by heating polypropylene with a degree of polymerization of 600 to 178-182° C. and stirring at 40-60 r / min for 6-8 minutes to obtain a polypropylene melt; mixing the polypropylene melt, 4-pentenoyl chloride, and styrene in a mass ratio of 8-10:1:0.09-0.11, continuing to stir at 178-182° C. for 8-10 minutes, adding dicumyl peroxide in an amount of 0.002-0.003 times the mass of the polypropylene melt, continuing to stir for 12-14 minutes, cooling to room temperature, and crushing to particles of 2-3 mm in size.

5. The method for preparing a mildew-proof and antibacterial vehicle window film according to claim 2, characterized in that: The flame retardant monomer in step (2) is prepared by mixing diethyl 2-bromoethylphosphonate, a functionalized monomer and N,N-dimethylethanolamine in a molar ratio of 1.4-1.6:1.4-1.6:1, stirring at 55-65°C and 200-300 r / min for 25-35 min, adding a mixed solvent in an amount of 14-16 times the mass of diethyl 2-bromoethylphosphonate, continuing stirring for 11.5-12.5 h, cooling to room temperature, and vacuum drying at -10-0°C for 28-32 h.

6. The method for preparing a mildew-proof and antibacterial vehicle window film according to claim 5, characterized in that: The functionalized monomer is prepared by mixing 3-dibutylaminopropylamine, maleic anhydride, and N,N-dimethylformamide in a molar ratio of 1:1:12-16, stirring for 25-35 minutes at 200-300 r / min, 85-95° C., and under nitrogen protection, adding nickel acetate tetrahydrate (0.03-0.05 times the mass of 3-dibutylaminopropylamine), triethylamine (0.009-0.011 times the volume of N,N-dimethylformamide), and acetic anhydride (0.38-0.42 times the volume of N,N-dimethylformamide), continuing stirring for 35-45 minutes, cooling to room temperature, pouring into deionized water at 0-4° C., stirring at 200-300 r / min for 11-13 hours, filtering, washing with deionized water 3-5 times, and drying at 75-85° C. for 12-14 hours.

7. The method for preparing a mildew-proof and antibacterial vehicle window film according to claim 5, characterized in that: The mixed solvent is prepared by uniformly mixing methanol and propanol in a volume ratio of 1:4.5-5.5.

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