Ultraviolet-proof film and preparation method thereof

Abstract

The invention discloses an anti-ultraviolet film and a preparation method thereof, and belongs to the technical field of protective films.The preparation method of the anti-ultraviolet film comprises the following steps that S1, resin, a modified anti-ultraviolet agent, a coloring agent and an organic solvent are mixed and stirred for 10-30 min at the rotating speed of 400-1000 rpm, then a curing agent is added, stirring is conducted for 10-30 min at the rotating speed of 400-1000 rpm, and a protective film glue solution is obtained; s2, coating a PET base film with the protective film glue solution, and heating and curing the protective film glue solution to obtain a protective glue layer; s3, a release film is attached to the side, away from the base material layer, of the protection adhesive layer, and the ultraviolet-proof film is obtained. The UV barrier rate of the prepared ultraviolet-proof film reaches 100%, the antibacterial rate reaches 97.22% or above, the contact angle reaches 116 degrees or above, the oxygen index reaches 40.7% or above, and the ultraviolet-proof film has lasting ultraviolet-proof performance.

Description

Technical Field

[0001] The invention belongs to the technical field of protective films, and in particular relates to an anti-ultraviolet film and a preparation method thereof. Background Art

[0002] With the rapid development of electronic technology, electronic products such as mobile phones, computers, and televisions have become almost necessities for people. People need to spend a lot of time facing these electronic products every day. However, the light emitted by the screens of these electronic products contains ultraviolet rays that are very harmful to the human body.

[0003] Ultraviolet rays are a general term for radiation with wavelengths from 100nm to 400nm in the electromagnetic spectrum. They cannot cause vision problems, but they are a type of harmful light. First of all, ultraviolet rays have an impact on human skin. When ultraviolet rays irradiate the skin for a long time, photodermatitis may occur, and erythema, itching, blisters, edema, etc. may appear on the skin. In severe cases, skin cancer may also occur. Secondly, ultraviolet rays also cause great harm to human eyes. According to surveys, the impact of ultraviolet rays on people is lifelong accumulation. Long-term exposure to harmful ultraviolet radiation can induce eye diseases such as cataracts and macular degeneration. These eye diseases are one of the main causes of blindness after the age of 60. In addition, ultraviolet rays also have an impact on the central nervous system. When ultraviolet rays act on the central nervous system, headaches, dizziness, and increased body temperature may occur. If an anti-ultraviolet film is prepared, it can effectively block ultraviolet rays and reduce damage to the eyes and skin. For example, some mobile phone films absorb and convert ultraviolet rays to prevent skin dryness caused by ultraviolet reflection, thereby reducing the occurrence of problems such as skin spots and chloasma. In addition, the anti-UV film can also prevent UV damage to the camera lens, extend the service life of the camera lens, and provide more realistic color reproduction.

[0004] The patent with patent announcement number CN114921211 B discloses a protective film glue, a protective film and its preparation method and a screen protective film. The patent uses ultraviolet absorbers and colorants to add ultraviolet absorbers to the glue, so that the glue layer is not only dark in color to block light from penetrating the glue layer, but also has the function of blocking ultraviolet rays. However, due to its relatively small molecular weight, the ultraviolet absorber is prone to external migration during processing and subsequent use, which is not conducive to the long-term anti-ultraviolet performance of the film material. Summary of the invention

[0005] In order to solve the problem that the prior art ultraviolet absorbers in the background technology are prone to outward migration during processing and subsequent use due to their relatively small molecular weight, which is not conducive to the long-term anti-ultraviolet performance of the film material, the purpose of the present invention is to provide an anti-ultraviolet film and a preparation method thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing an ultraviolet protection film, comprising the following steps:

[0008] S1: mixing a resin, a modified UV protection agent, a colorant, and an organic solvent, stirring at a speed of 400-1000 rpm for 10-30 min, adding a curing agent, and stirring at a speed of 400-1000 rpm for 10-30 min to obtain a protective film glue solution; the modified UV protection agent is prepared by blending modified chitosan and ammonium polyphosphate, wherein the modified chitosan is obtained by chemically connecting chitosan and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid using 3-chloro-5-(trifluoromethyl)benzoyl chloride as an intermediary;

[0009] S2, coating the protective film glue on the PET base film, heating and curing, to obtain a protective glue layer;

[0010] S3, laminating a release film on the side of the protective adhesive layer facing away from the substrate layer to obtain an anti-ultraviolet film.

[0011] Furthermore, the protective film glue solution in S1 includes the following raw materials in parts by weight: 15-25 parts of resin, 0.01-0.05 parts of modified ultraviolet absorber, 0.02-0.06 parts of colorant, 30 parts of organic solvent, and 0.1-0.5 parts of curing agent.

[0012] Furthermore, the resin in S1 is any one of polyurethane resin Archsol_8355, acrylic resin 866B MQ or silicone resin SM-903MQ.

[0013] Furthermore, the colorant in S1 is one or more of Astrong UB054, Xianlite UJ001, and Xianlite UJ007.

[0014] Furthermore, the organic solvent in S1 is any one or more of toluene, isopropanol, acetone, methyl isobutyl ketone, butanone, cyclohexanone, and propylene glycol methyl ether.

[0015] Furthermore, the curing agent in S1 is any one of Gusa B1358A, Bassington Trixene BI 7982, and BASF HB175.

[0016] Furthermore, the temperature of the heating and curing in S2 is 100-120° C. and the time is 2-3 min.

[0017] Furthermore, the preparation method of the modified UV-blocking agent is:

[0018] The modified chitosan was added to a 1wt% dilute acetic acid solution, stirred at 25°C for 20-30min, then heated to 60°C, and ammonium polyphosphate was added. The mixture was stirred for 1-1.5h. After the reaction was completed, the solution was filtered, washed and dried to obtain a modified UV protector.

[0019] The dosage ratio of the modified chitosan, 1wt% dilute acetic acid solution and ammonium polyphosphate is 5g:250mL:5-10g.

[0020] The modified chitosan uses 3-chloro-5-(trifluoromethyl)benzoyl chloride as an intermediary to tightly connect chitosan and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid through chemical bonds. As a small molecule ultraviolet absorber, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid has the problem of easy external migration during processing and subsequent use. By grafting the substance onto chitosan, the precipitation of the small molecule ultraviolet absorber can be reduced, so that the anti-ultraviolet film prepared with modified chitosan as part of the raw material has long-term anti-ultraviolet performance. Chitosan is a natural cationic polysaccharide with a wide range of antibacterial activity, which can improve the antibacterial performance of the film. 2-Hydroxy-4-methoxybenzophenone-5-sulfonic acid contains benzophenone groups, which is a typical ultraviolet absorber and can improve the ability of the film to absorb ultraviolet rays. 3-Chloro-5-(trifluoromethyl)benzoyl chloride contains trifluoromethyl, which is a highly hydrophobic group that can improve the hydrophobicity of the film, thereby giving the UV protection film anti-oil and anti-fingerprint capabilities.

[0021] In order to improve the flame retardant properties of the protective film, the present invention further blends ammonium polyphosphate with modified chitosan on the basis of modified chitosan to obtain a modified UV inhibitor. Ammonium polyphosphate is rich in nitrogen and phosphorus flame retardant elements, and the modified chitosan contains sulfur. The nitrogen, phosphorus and sulfur flame retardant elements can absorb heat and decompose during the film combustion process, forming a non-volatile protective layer on the film surface and isolating the air, while releasing non-combustible gases such as carbon dioxide, sulfur dioxide, and ammonia, diluting oxygen and combustible cracking gas, and improving the flame retardant properties of the film. Ammonium polyphosphate is easy to agglomerate and is unevenly dispersed. By blending with chitosan, the substance can be evenly dispersed in the raw materials, improving the compatibility with other raw materials, and further improving the flame retardant properties.

[0022] Furthermore, the preparation method of the modified chitosan is:

[0023] B1: Add 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, triethylamine and tetrahydrofuran into a three-necked flask, add 3-chloro-5-(trifluoromethyl)benzoyl chloride solution dropwise at room temperature with stirring, react at 60°C for 6-7h, pour into ice water to precipitate, filter, wash the filter cake with saturated sodium bicarbonate solution, and dry to obtain an intermediate;

[0024] Among them, the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, triethylamine, tetrahydrofuran, and 3-chloro-5-(trifluoromethyl)benzoyl chloride solution is 30.8 g:14 mL:100 mL:100 mL; the 3-chloro-5-(trifluoromethyl)benzoyl chloride solution is prepared by dissolving 3-chloro-5-(trifluoromethyl)benzoyl chloride in tetrahydrofuran, and the dosage ratio of 3-chloro-5-(trifluoromethyl)benzoyl chloride to tetrahydrofuran is 41.3 g:100 mL.

[0025] In the above steps, the hydroxyl group in 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid undergoes an esterification reaction with the acyl chloride group in 3-chloro-5-(trifluoromethyl)benzoyl chloride to generate an ester group, thereby obtaining an intermediate containing a trifluoromethyl group and sulfur element.

[0026] B2: Add carboxymethyl chitosan, sodium hydroxide and isopropanol into a three-necked flask, react at 40°C for 1 h with stirring, then add the intermediate, react at 80°C for 24 h, adjust the pH to 7 with glacial acetic acid, add anhydrous ethanol to precipitate, filter, and dry the filter cake to obtain modified chitosan.

[0027] The usage ratio of carboxymethyl chitosan, sodium hydroxide, isopropanol and intermediate is 2g:1.2g:40-50mL:1.5g.

[0028] In the above steps, the amino group of carboxymethyl chitosan undergoes a substitution reaction with the chlorine of the intermediate to obtain modified chitosan.

[0029] In a second aspect, the present invention provides an anti-ultraviolet film, which is made by the preparation method of the anti-ultraviolet film described in any one of the above contents.

[0030] Beneficial effects of the present invention:

[0031] 1. The UV blocking rate of the anti-ultraviolet film prepared by the present invention reaches 100%, the antibacterial rate reaches more than 97.22%, the contact angle reaches more than 116°, the oxygen index reaches more than 40.7%, and has a long-lasting anti-ultraviolet performance. DETAILED DESCRIPTION

[0032] 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 described embodiments 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 creative work are within the scope of protection of the present invention.

[0033] The carboxymethyl chitosan in the present invention is O-carboxymethyl chitosan (CMCh), DD=80%, viscosity 80 mPas, purchased from McLean Biochemical Co., Ltd.

[0034] Preparation Example 1

[0035] The preparation method of modified chitosan in this preparation example is:

[0036] B1: Add 30.8 g of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 14 mL of triethylamine and 100 mL of tetrahydrofuran into a three-necked flask, add 100 mL of 3-chloro-5-(trifluoromethyl)benzoyl chloride solution dropwise at room temperature under stirring (3-chloro-5-(trifluoromethyl)benzoyl chloride solution is prepared by dissolving 3-chloro-5-(trifluoromethyl)benzoyl chloride in tetrahydrofuran, and the ratio of 3-chloro-5-(trifluoromethyl)benzoyl chloride to tetrahydrofuran is 41.3 g:100 mL), react at 60° C. for 6 h, pour into ice water to precipitate, filter, wash the filter cake with saturated sodium bicarbonate solution, and dry to obtain an intermediate;

[0037] B2: Add 2g carboxymethyl chitosan, 1.2g sodium hydroxide and 40mL isopropanol into a three-necked flask, react at 40°C for 1h with stirring, then add 1.5g intermediate, react at 80°C for 24h, adjust the pH to 7 with glacial acetic acid, add anhydrous ethanol to precipitate, filter, and dry the filter cake to obtain modified chitosan.

[0038] Preparation Example 2

[0039] The preparation method of modified chitosan in this preparation example is:

[0040] B1: Add 30.8 g of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 14 mL of triethylamine and 100 mL of tetrahydrofuran into a three-necked flask, add 100 mL of 3-chloro-5-(trifluoromethyl)benzoyl chloride solution dropwise at room temperature under stirring (3-chloro-5-(trifluoromethyl)benzoyl chloride solution is prepared by dissolving 3-chloro-5-(trifluoromethyl)benzoyl chloride in tetrahydrofuran, and the ratio of 3-chloro-5-(trifluoromethyl)benzoyl chloride to tetrahydrofuran is 41.3 g:100 mL), react at 60° C. for 7 h, pour into ice water to precipitate, filter, wash the filter cake with saturated sodium bicarbonate solution, and dry to obtain an intermediate;

[0041] B2: Add 2g carboxymethyl chitosan, 1.2g sodium hydroxide and 50mL isopropanol into a three-necked flask, react at 40°C for 1h with stirring, then add 1.5g intermediate, react at 80°C for 24h, adjust the pH to 7 with glacial acetic acid, add anhydrous ethanol to precipitate, filter, and dry the filter cake to obtain modified chitosan.

[0042] Comparative Example 1

[0043] The preparation method of modified chitosan in this reference example is:

[0044] B1: Add 30.8 g of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 14 mL of triethylamine and 100 mL of tetrahydrofuran into a three-necked flask, add 100 mL of monochloroacetyl chloride solution dropwise at room temperature under stirring (monochloroacetyl chloride solution is prepared by dissolving monochloroacetyl chloride in tetrahydrofuran, and the ratio of monochloroacetyl chloride to tetrahydrofuran is 18 g:100 mL), react at 60°C for 6 h, pour into ice water to precipitate, filter, wash the filter cake with saturated sodium bicarbonate solution, and dry to obtain an intermediate;

[0045] B2: Add 2g of carboxymethyl chitosan, 1.2g of sodium hydroxide and 40mL of isopropanol into a three-necked flask, react at 40°C for 1h with stirring, then add 1.1g of the intermediate, react at 80°C for 24h, adjust the pH to 7 with glacial acetic acid, add anhydrous ethanol to precipitate, filter, and dry the filter cake to obtain modified chitosan.

[0046] Comparative Example 2

[0047] B1: Add 22.8 g of 2-hydroxy-4-methoxybenzophenone, 14 mL of triethylamine and 100 mL of tetrahydrofuran into a three-necked flask, add 100 mL of monochloroacetyl chloride solution dropwise at room temperature under stirring (the monochloroacetyl chloride solution is prepared by dissolving monochloroacetyl chloride in tetrahydrofuran, and the ratio of monochloroacetyl chloride to tetrahydrofuran is 18 g:100 mL), react at 60°C for 6 h, pour into ice water to precipitate, filter, wash the filter cake with saturated sodium bicarbonate solution, and dry to obtain an intermediate;

[0048] B2: Add 2g of carboxymethyl chitosan, 1.2g of sodium hydroxide and 40mL of isopropanol into a three-necked flask, react at 40°C for 1h with stirring, then add 0.9g of the intermediate, react at 80°C for 24h, adjust the pH to 7 with glacial acetic acid, add anhydrous ethanol to precipitate, filter, and dry the filter cake to obtain modified chitosan.

[0049] Preparation Example 3

[0050] The preparation method of the modified UV-blocking agent in this preparation example is:

[0051] 5 g of the modified chitosan prepared in Preparation Example 1 was added to 250 mL of 1 wt% dilute acetic acid solution, stirred at 25 ° C for 20 min, then heated to 60 ° C, 5 g of ammonium polyphosphate was added, stirred for reaction for 1 h, and after the reaction was completed, filtered, washed and dried to obtain a modified UV inhibitor.

[0052] Preparation Example 4

[0053] The preparation method of the modified UV-blocking agent in this preparation example is:

[0054] 5 g of the modified chitosan prepared in Preparation Example 2 was added to 250 mL of 1 wt% dilute acetic acid solution, stirred at 25 ° C for 30 min, then heated to 60 ° C, 10 g of ammonium polyphosphate was added, and the reaction was stirred for 1.5 h. After the reaction was completed, it was filtered, washed and dried to obtain a modified UV inhibitor.

[0055] Comparative Example 4

[0056] Compared with Preparation Example 3, the only difference is:

[0057] In Preparation Example 3, the modified chitosan prepared in Preparation Example 1 was replaced by the substance prepared in Control Example 1.

[0058] Comparative Example 5

[0059] Compared with Preparation Example 3, the only difference is:

[0060] In Preparation Example 3, the modified chitosan prepared in Preparation Example 1 was replaced by the substance prepared in Control Example 2.

[0061] Comparative Example 6

[0062] Compared with the control example 5, the only difference is:

[0063] The modified chitosan was not treated with ammonium polyphosphate, and the modified chitosan prepared in Control Example 2 was directly used as the modified UV shielding agent.

[0064] Comparative Example 7

[0065] This comparative example directly uses 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid as a UV shielding agent.

[0066] Example 1

[0067] This preparation example provides a method for preparing an anti-ultraviolet film, comprising the following steps:

[0068] S1: 15 parts of polyurethane resin Archsol-8355, 0.01 parts of modified UV protection agent prepared in Preparation Example 3, 0.02 parts of Xianlite UJ001, and 30 parts of propylene glycol methyl ether were mixed, stirred at 400 rpm for 10 min, and then 0.1 parts of BASF HB175 were added, and stirred at 400 rpm for 10 min to obtain protective film glue;

[0069] S2, coating the protective film glue on the PET base film, heating and curing at 110° C. for 2.5 min to obtain a protective glue layer;

[0070] S3, laminating a release film on the side of the protective adhesive layer facing away from the substrate layer to obtain an anti-ultraviolet film.

[0071] Example 2

[0072] This preparation example provides a method for preparing an anti-ultraviolet film, comprising the following steps:

[0073] S1: 20 parts of acrylic resin 866B MQ, 0.03 parts of the modified UV shield prepared in Preparation Example 4, 0.04 parts of Sunlite UJ007, and 30 parts of isopropanol were mixed, and stirred at 1000 rpm for 30 min, and then 0.3 parts of Gusa B1358A were added, and stirred at 1000 rpm for 30 min to obtain a protective film adhesive solution;

[0074] S2, coating the protective film glue on the PET base film, heating and curing at 110° C. for 2.5 min to obtain a protective glue layer;

[0075] S3, laminating a release film on the side of the protective adhesive layer facing away from the substrate layer to obtain an anti-ultraviolet film.

[0076] Example 3

[0077] This preparation example provides a method for preparing an anti-ultraviolet film, comprising the following steps:

[0078] S1: 25 parts of silicone resin SM-903MQ, 0.04 parts of modified UV protection agent prepared in Preparation Example 4, 0.06 parts of Astrong UB054, and 30 parts of toluene were mixed, stirred at 700 rpm for 20 min, and then 0.5 parts of Gusa B1358A were added, and stirred at 700 rpm for 20 min to obtain a protective film adhesive solution;

[0079] S2, coating the protective film glue on the PET base film, heating and curing at 110° C. for 2.5 min to obtain a protective glue layer;

[0080] S3, laminating a release film on the side of the protective adhesive layer facing away from the substrate layer to obtain an anti-ultraviolet film.

[0081] Example 4

[0082] The difference between this embodiment and embodiment 1 is that:

[0083] The “heating and curing at 110° C. for 2.5 min” in Example 1 was replaced with “heating and curing at 100° C. for 2 min”.

[0084] Example 5

[0085] The difference between this embodiment and embodiment 1 is that:

[0086] In Example 1, "heating and curing at 110° C. for 2.5 min" was replaced with "heating and curing at 120° C. for 3 min".

[0087] Comparative Example 1

[0088] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that:

[0089] The modified UV shielding agent prepared in Preparation Example 3 in Example 1 was replaced by the substance prepared in Control Example 4.

[0090] Comparative Example 2

[0091] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that:

[0092] The modified UV shielding agent prepared in Preparation Example 3 in Example 1 was replaced by the substance prepared in Control Example 5.

[0093] Comparative Example 3

[0094] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that:

[0095] The modified UV shielding agent prepared in Preparation Example 3 in Example 1 was replaced by the substance prepared in Control Example 6.

[0096] Comparative Example 4

[0097] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that:

[0098] The modified UV shielding agent prepared in Preparation Example 3 in Example 1 was replaced by the substance prepared in Control Example 7.

[0099] The performance test of the anti-ultraviolet films prepared in Examples 1 to 5 and Comparative Examples 1 to 4 was carried out. The test items are as follows, and the results are shown in Table 1:

[0100] 1. Test of UV light blocking rate: Use a spectrophotometer to test the UV light blocking rate of the finished film.

[0101] 2. Antibacterial property: After cleaning and drying the membrane, cut it into membrane sheets with a radius of 30mm and sterilize it under ultraviolet light. After inoculating E. coli on the flat agar medium and activating it for 24 hours, take 2 loops and add them to the culture medium, dilute to a bacterial suspension with a concentration of 1.0×10 CFU / mL. Pipette 0.2mL of the bacterial suspension and drop it on the protective film, cover the sterilized polyethylene film on the sample, culture it in an incubator at 37°C for 24 hours, wash the sample with the eluent, shake the eluted bacteria thoroughly, inoculate it in the nutrient agar medium, culture it at 37°C for 24 hours, and then count the live bacteria. The antibacterial rate A = (BC) / B×100%; B is the average number of recovered bacteria in the control group; C is the average number of recovered bacteria in the experimental group.

[0102] 3. Hydrophobicity test: Use JC2000D2G contact angle tester to test the water contact angle of the sample.

[0103] 4. Flame retardant performance test: The oxygen index LOI value is tested according to GB / T 2406.2-2009 standard.

[0104] 5. Anti-aging experiment: Select "GB / T16422.2-2022 Plastic Laboratory Light Source Exposure Test Method" as the standard, cut the film into 3cm*3cm samples, place it in a xenon arc lamp exposure light aging test box for 2000 hours, and then use "GB / T39822-2021 Determination of Plastic Yellowness Index and Its Change Value" as the standard to test the yellowness index of the sample. Each sample is tested three times and the average value is taken after measurement.

[0105] Table 1

[0106]

[0107]

[0108] Note: “ / ” in Table 1 means the item hardly has the performance.

[0109] As can be seen from Table 1, the UV blocking rates of the films prepared in Examples 1 to 5 all reached 100%, the antibacterial rates reached over 97.22%, the contact angles reached over 116°, the oxygen indexes reached over 40.7%, and they had durable UV protection properties.

[0110] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0111] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an anti-ultraviolet film, characterized in that: The following steps are involved: S1: mixing a resin, a modified UV protection agent, a colorant, and an organic solvent, stirring at a speed of 400-1000 rpm for 10-30 min, adding a curing agent, and stirring at a speed of 400-1000 rpm for 10-30 min to obtain a protective film glue solution; the modified UV protection agent is prepared by blending modified chitosan and ammonium polyphosphate, wherein the modified chitosan is obtained by chemically connecting chitosan and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid using 3-chloro-5-(trifluoromethyl)benzoyl chloride as an intermediary; S2, coating the protective film glue on the PET base film, heating and curing, to obtain a protective glue layer; S3, laminating a release film on the side of the protective adhesive layer facing away from the substrate layer to obtain an anti-ultraviolet film.

2. The method for preparing an anti-ultraviolet film according to claim 1, characterized in that: The protective film glue solution in S1 includes the following raw materials in parts by weight: 15-25 parts of resin, 0.01-0.05 parts of modified ultraviolet absorber, 0.02-0.06 parts of colorant, 30 parts of organic solvent, and 0.1-0.5 parts of curing agent.

3. The method for preparing an anti-ultraviolet film according to claim 1, characterized in that: The resin in S1 is any one of polyurethane resin Archsol_8355, acrylic resin 866B MQ or silicone resin SM-903MQ; the colorant is one or more of Astrong UB054, Xianlite UJ001 and Xianlite UJ007; the curing agent is any one of Gusa B1358A, Bassington Trixene BI 7982 and BASF HB175; the organic solvent is any one or more of toluene, isopropanol, acetone, methyl isobutyl ketone, butanone, cyclohexanone and propylene glycol methyl ether.

4. The method for preparing an anti-ultraviolet film according to claim 1, characterized in that: The temperature of the heating curing in S2 is 100-120° C. and the time is 2-3 minutes.

5. The method for preparing an anti-ultraviolet film according to claim 1, characterized in that: The preparation method of the modified UV-blocking agent is as follows: The modified chitosan was added to a 1wt% dilute acetic acid solution, stirred at 25°C for 20-30min, then heated to 60°C, and ammonium polyphosphate was added. The mixture was stirred for 1-1.5h. After the reaction was completed, the solution was filtered, washed and dried to obtain a modified UV protector.

6. The method for preparing an anti-ultraviolet film according to claim 5, characterized in that: The usage ratio of modified chitosan, 1wt% dilute acetic acid solution and ammonium polyphosphate is 5g:250mL:5-10g.

7. The method for preparing an anti-ultraviolet film according to claim 5, characterized in that: The preparation method of the modified chitosan is: B1: Add 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, triethylamine and tetrahydrofuran into a three-necked flask, add 3-chloro-5-(trifluoromethyl)benzoyl chloride solution dropwise at room temperature with stirring, react at 60°C for 6-7h, pour into ice water to precipitate, filter, wash the filter cake and dry to obtain an intermediate; B2: Add carboxymethyl chitosan, sodium hydroxide and isopropanol into a three-necked flask, react at 40°C for 1 hour with stirring, then add the intermediate, react at 80°C for 24 hours, adjust the pH to 7, precipitate, filter, and dry the filter cake to obtain modified chitosan.

8. The method for preparing an anti-ultraviolet film according to claim 5, characterized in that: In B1, the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, triethylamine, tetrahydrofuran, and 3-chloro-5-(trifluoromethyl)benzoyl chloride solution is 30.8 g:14 mL:100 mL:100 mL; the 3-chloro-5-(trifluoromethyl)benzoyl chloride solution is prepared by dissolving 3-chloro-5-(trifluoromethyl)benzoyl chloride in tetrahydrofuran, and the dosage ratio of 3-chloro-5-(trifluoromethyl)benzoyl chloride to tetrahydrofuran is 41.3 g:100 mL.

9. The method for preparing an anti-ultraviolet film according to claim 5, characterized in that: The usage ratio of carboxymethyl chitosan, sodium hydroxide, isopropanol and intermediate in B2 is 2g:1.2g:40-50mL:1.5g.

10. An anti-ultraviolet film, made by the preparation method of the anti-ultraviolet film according to any one of claims 1 to 9.

Images