Multilayer antibacterial silica gel protective film and preparation method thereof

Abstract

The invention relates to the technical field of protective films, and discloses a multilayer antibacterial silica gel protective film and a preparation method thereof. The silica gel protective film sequentially comprises a base material layer, a functional silica gel layer and a release film layer from top to bottom, wherein the base material layer is a PET anti-aging film, the release film layer is a PET release film, and the functional silica gel layer is prepared by coating the surface of the PET anti-aging film with functional silica gel. The functional silica gel comprises the following raw materials in parts by weight: 30-40 parts of vinyl silicone oil, 30-40 parts of MQ resin, 5-8 parts of antibacterial silicone oil, 1-2 parts of a modified antioxidant, 0.5-2 parts of a dispersing agent, 60-100 parts of ethyl acetate, 0.5-2 parts of a cross-linking agent and 0.5-2 parts of a catalyst, the antibacterial silicone oil is introduced, so that the antibacterial performance of the matrix is improved, and the modified antioxidant is introduced, so that compared with a traditional antioxidant, the anti-aging performance is better.

Description

Technical Field

[0001] The invention relates to the technical field of protective films, and in particular to a multi-layer antibacterial silica gel protective film and a preparation method thereof. Background Art

[0002] Silicone protective films are generally single-layer and multi-layer. Multi-layer silicone protective films are usually composed of multiple layers of materials, mainly including substrate, adhesive layer and release layer. Multi-layer silicone protective films are widely used in electronics, optoelectronics, automobiles, medical and other fields due to their excellent physical and chemical properties. They can effectively protect various equipment and components from external environmental damage and extend their service life.

[0003] With the increasing demand for use, some properties of silicone protective films need to be improved, such as: (1) Poor antibacterial properties. Although ordinary silicone protective films can use their antioxidant ability and structural characteristics to resist bacteria, their antibacterial efficiency is limited, which limits their application in the medical field; (2) Poor aging resistance. In environments such as high temperature and oxygen, the chemical bonds of silicone molecular chains are easily broken, which accelerates the aging of silicone, resulting in performance degradation and reduced service life. Therefore, researchers need to develop a silicone protective film with excellent antibacterial and aging resistance to meet actual needs. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a multi-layer antibacterial silica gel protective film and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A multi-layer antibacterial silicone protective film, comprising, from top to bottom, a substrate layer, a functional silicone layer and a release film layer; the substrate layer is a PET anti-aging film; the functional silicone layer is prepared by coating the functional silicone on the surface of the PET anti-aging film; the release film layer is a PET release film;

[0007] The functional silica gel comprises the following raw materials in parts by weight: 30-40 parts of vinyl silicone oil, 30-40 parts of MQ resin, 5-8 parts of antibacterial silicone oil, 1-2 parts of modified antioxidant, 0.5-2 parts of dispersant, 60-100 parts of ethyl acetate, 0.5-2 parts of crosslinking agent, and 0.5-2 parts of catalyst;

[0008] The dispersant is silicone modified polyether, the crosslinking agent is Dow SYL-OFFTMSL 7028, and the catalyst is platinum catalyst;

[0009] The antibacterial silicone oil is prepared by the following steps:

[0010] Step A1, 1,5-dibromopentane and sodium hydroxide are evenly dispersed in N,N-dimethylformamide, 1-allylimidazole is added, and the mixture is stirred at room temperature for 24 hours, and purified to obtain a brominated imidazole derivative;

[0011] Further, in step A1, the usage ratio of 1,5-dibromopentane, sodium hydroxide, N,N-dimethylformamide and 1-allylimidazole is 0.01-0.02 mol: 1.5-3 g: 100 mL: 0.01-0.02 mol;

[0012] Step A2, mixing nano zirconium phosphate (ZrP), carboxymethyl chitosan (CMCS) and deionized water, transferring to a ball mill (ball to material ratio of 2:1) and ball milling at a speed of 800-1000 m / min for 40-60 min, collecting the ball milling product, and obtaining CMCS@ZrP (carboxymethyl chitosan coated nano zirconium phosphate);

[0013] Further, in step A2, the dosage ratio of nano zirconium phosphate, carboxymethyl chitosan and deionized water is 0.3-1g: 0.05-0.1g: 50g;

[0014] Step A3, dispersing CMCS@ZrP in N,N-dimethylformamide, adding bromoimidazole derivative and sodium hydroxide, stirring and reacting for 18-24 hours, centrifuging and purifying to obtain a composite antibacterial agent;

[0015] Further, in step A3, the usage ratio of CMCS@ZrP, N,N-dimethylformamide, bromoimidazole derivative and sodium hydroxide is 3-5 g: 100 mL: 2-4 g: 1.2-2.5 g;

[0016] Step A4, the composite antibacterial agent, chloroplatinic acid isopropanol solution and toluene are mixed and stirred evenly, and nitrogen is replaced three times. Under nitrogen conditions, hydrogen-containing silicone oil is slowly added, and the temperature is raised to 80-90° C. to react for 2-3 hours, and distilled under reduced pressure to obtain antibacterial silicone oil;

[0017] Furthermore, in step A4, the dosage ratio of the composite antibacterial agent, chloroplatinic acid isopropanol solution, toluene and hydrogen-containing silicone oil is 0.3-0.6 g: 6-9 g: 50 mL: 2.5-5 g, and the mass ratio of chloroplatinic acid and isopropanol in the chloroplatinic acid isopropanol solution is 0.05-0.1:100.

[0018] The modified antioxidant is prepared by the following steps:

[0019] Step B1, 4-nitrophenol is dispersed uniformly in carbon tetrachloride, triethylamine is added and stirred for 0.5-1h, then diphenyl phosphite carbon tetrachloride solution is slowly added dropwise in an ice-water bath, stirred at room temperature for 24h, extracted, washed, dried, distilled under reduced pressure, purified, and the product is collected; zinc powder, ethyl acetate and deionized water are added to the product and mixed and stirred uniformly, ammonium chloride is added in 5 times (each time with an interval of 10min), stirring is continued for 1.5-2.5h, suction filtered, extracted, dried, distilled under reduced pressure, purified, and the phosphite derivative is obtained;

[0020] Further, the usage ratio of 4-nitrophenol, carbon tetrachloride, triethylamine and diphenyl phosphite carbon tetrachloride solution in the product of step B1 is 0.01-0.02 mol:100 mL:0.008-0.016 mol:20 mL;

[0021] Furthermore, the diphenyl phosphite carbon tetrachloride solution in the product of step B1 is prepared by mixing and stirring diphenyl phosphite and carbon tetrachloride in a dosage ratio of 0.04-0.08 mol: 20 mL;

[0022] Further, the amount ratio of the product, zinc powder, ethyl acetate, deionized water and ammonium chloride in step B1 is 1.5-3 g: 1.2-2.4 g: 30 mL: 30 mL: 2-4 g;

[0023] Step B2, mixing the phosphite derivative and potassium carbonate in deionized water, stirring at 45° C. for 30 min, then transferring to an ice water bath, slowly dropping β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionylbenzene chloride solution, reacting at room temperature for 8-12 h after the addition, standing for 24 h, distilling under reduced pressure, washing, and drying to obtain a modified antioxidant;

[0024] Furthermore, in step B2, the dosage ratio of the phosphite derivative, potassium carbonate, deionized water and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution is 0.85-2.5 g: 2.07-4.14 g: 20 mL: 80 mL, and the β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution is prepared by mixing and stirring β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride and benzene in a dosage ratio of 2.2-4.4 g: 80 mL.

[0025] A method for preparing a multi-layer antibacterial silica gel protective film comprises the following steps:

[0026] Step S1, weighing raw materials by weight, mixing vinyl silicone oil and MQ resin in ethyl acetate and stirring evenly, then adding a crosslinking agent, antibacterial silicone oil, modified antioxidant, dispersant and catalyst and stirring evenly, and then filtering through a 300-500 mesh filter cloth to obtain functional silica gel;

[0027] Step S2, uniformly coating the functional silicone on one side of the PET anti-aging film to form a functional silicone layer, the thickness of the film is 5-8 μm, and then applying the PET release film on the functional silicone layer to form a release film layer, that is, a multi-layer antibacterial silicone protective film.

[0028] Beneficial effects of the present invention:

[0029] The silicone protective film of the present invention comprises a substrate layer, a functional silicone layer and a release film layer from top to bottom; wherein the substrate layer is a PET anti-aging film, the release film layer is a PET release film, and the functional silicone layer is prepared by coating the functional silicone on the surface of the PET anti-aging film. Antibacterial silicone oil is introduced into the functional silicone to improve the antibacterial property of the substrate, and a modified antioxidant is introduced, which has better anti-aging performance than traditional antioxidants.

[0030] In the antibacterial silicone oil, 1,5-dibromopentane and 1-allylimidazole are first reacted to obtain brominated imidazole derivatives; carboxymethyl chitosan is then used to coat nano zirconium phosphate to obtain CMCS@ZrP; a composite antibacterial agent is obtained by substitution reaction between brominated imidazole derivatives and CMCS@ZrP; finally, the double bonds in the composite antibacterial agent react with the active hydrogen in hydrogen-containing silicone oil to obtain antibacterial silicone oil. The antibacterial silicone oil has good compatibility in the matrix and significantly improves the antibacterial properties of silica gel; the imidazole cations, carboxymethyl chitosan and zirconium phosphate introduced into the antibacterial silicone oil have a synergistic effect, which improves the antibacterial properties of silica gel; among them, zirconium phosphate can release zirconium ions, which destroy the integrity of the bacterial cell membrane after contacting the bacterial cell membrane, and cause the leakage of intracellular substances, thereby leading to the death of bacteria to achieve antibacterial effects; brominated imidazole derivatives have a cationic structure, which can use the interaction between cations and negative charges on the bacterial cell membrane to destroy the bacterial cell wall and kill the bacteria.

[0031] In the modified antioxidant, 4-nitrophenol and diphenyl phosphite are first used to synthesize the product under the catalytic action of triethylamine, and then the nitro group in the product is reduced to amino to obtain a phosphite derivative; then the phosphite derivative is reacted with β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride to obtain a modified antioxidant. The modified antioxidant introduces phosphite structure and hindered phenol structure, which can synergistically improve the aging resistance of the silicone protective film, avoiding the limited aging resistance caused by the insufficient antioxidant performance of traditional hindered phenol antioxidants; among them, the phosphite structure can terminate the active free radicals generated by heat and oxygen in the matrix, and decompose the hydrogen peroxide structure, thereby improving the aging resistance of the matrix. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1: Antibacterial silicone oil is prepared by the following steps:

[0034] Step A1, 0.01 mol 1,5-dibromopentane and 1.5 g sodium hydroxide were evenly dispersed in 100 mL N,N-dimethylformamide, 0.01 mol 1-allylimidazole was added, and the mixture was stirred at room temperature for 24 h, and purified to obtain a brominated imidazole derivative;

[0035] Step A2, 0.3 g of nano zirconium phosphate, 0.05 g of carboxymethyl chitosan and 50 g of deionized water were mixed and stirred evenly, transferred to a ball mill (ball to material ratio of 2:1) and ball milled at a speed of 800 m / min for 40 min, and the ball milled product was collected to obtain CMCS@ZrP;

[0036] Step A3, dispersing 3 g of CMCS@ZrP in 100 mL of N,N-dimethylformamide, adding 2 g of bromoimidazole derivative and 1.2 g of sodium hydroxide, stirring and reacting for 18 h, centrifuging and purifying to obtain a composite antibacterial agent;

[0037] Step A4, mix 0.3g of the composite antibacterial agent, 6g of chloroplatinic acid isopropanol solution and 50mL of toluene, stir evenly, replace with nitrogen three times, slowly add 2.5g of hydrogen-containing silicone oil under nitrogen conditions, and heat to 80°C to react for 2h, and distill under reduced pressure to obtain antibacterial silicone oil. The mass ratio of chloroplatinic acid and isopropanol in the chloroplatinic acid isopropanol solution is 0.05:100.

[0038] The modified antioxidant is prepared by the following steps:

[0039] Step B1, 0.01 mol of 4-nitrophenol is evenly dispersed in 100 mL of carbon tetrachloride, 0.008 mol of triethylamine is added and stirred for 0.5 h, then 20 mL of diphenyl phosphite carbon tetrachloride solution is slowly added dropwise in an ice-water bath, stirred at room temperature for 24 h, extracted, washed, dried, distilled under reduced pressure, purified, and the product is collected; then 1.2 g of zinc powder, 30 mL of ethyl acetate and 30 mL of deionized water are added to 1.5 g of the product and mixed and stirred evenly, and then 2 g of ammonium chloride is added in 5 times (each time with an interval of 10 min), and the stirring is continued for 1.5 h, and suction filtration, extraction, drying, distillation under reduced pressure, purification, and the phosphite derivative is obtained. The diphenyl phosphite carbon tetrachloride solution is prepared by mixing and stirring diphenyl phosphite and carbon tetrachloride in a dosage ratio of 0.04 mol: 20 mL;

[0040] Step B2, 0.85g of phosphite derivative and 2.07g of potassium carbonate were mixed in 20mL of deionized water, and stirred at 45°C for 30min, then transferred to an ice water bath, and 80mL of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was slowly added dropwise. After the addition was completed, the mixture was reacted at room temperature for 8h, allowed to stand for 24h, and distilled under reduced pressure, washed, and dried to obtain a modified antioxidant. The β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was prepared by mixing and stirring β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride and benzene in a dosage ratio of 2.2g:80mL.

[0041] Embodiment 2: antibacterial silicone oil is prepared by the following steps:

[0042] Step A1, 0.015 mol 1,5-dibromopentane and 2.3 g sodium hydroxide were evenly dispersed in 100 mL N,N-dimethylformamide, 0.015 mol 1-allylimidazole was added, and the mixture was stirred at room temperature for 24 h, and purified to obtain a brominated imidazole derivative;

[0043] Step A2, 0.6 g of nano zirconium phosphate, 0.075 g of carboxymethyl chitosan and 50 g of deionized water were mixed and stirred evenly, transferred to a ball mill (ball to material ratio of 2:1) and ball milled at a speed of 1000 m / min for 50 min, and the ball milled product was collected to obtain CMCS@ZrP;

[0044] Step A3, 4 g CMCS@ZrP was evenly dispersed in 100 mL N, N-dimethylformamide, and then 3 g bromoimidazole derivative and 1.8 g sodium hydroxide were added and stirred for 21 h, centrifuged and purified to obtain a composite antibacterial agent;

[0045] Step A4, mix 0.45g of the composite antibacterial agent, 7.5g of chloroplatinic acid isopropanol solution and 50mL of toluene, stir evenly, replace with nitrogen three times, slowly add 3.8g of hydrogen-containing silicone oil under nitrogen conditions, and heat to 85°C to react for 2.5h, and distill under reduced pressure to obtain antibacterial silicone oil. The mass ratio of chloroplatinic acid and isopropanol in the chloroplatinic acid isopropanol solution is 0.075:100.

[0046] The modified antioxidant is prepared by the following steps:

[0047] Step B1, 0.015mol 4-nitrophenol is evenly dispersed in 100mL carbon tetrachloride, 0.012mol triethylamine is added and stirred for 0.75h, then 20mL diphenyl phosphite carbon tetrachloride solution is slowly added dropwise in an ice water bath, stirred at room temperature for 24h, extracted, washed, dried, distilled under reduced pressure, purified, and the product is collected; then 1.8g zinc powder, 30mL ethyl acetate and 30mL deionized water are added to 2.2g of the product and mixed and stirred evenly, and then 3g ammonium chloride is added in 5 times (each time with an interval of 10min), and the stirring is continued for 2h, and suction filtration, extraction, drying, distillation under reduced pressure, purification, and the phosphite derivative is obtained. The diphenyl phosphite carbon tetrachloride solution is prepared by mixing and stirring diphenyl phosphite and carbon tetrachloride in a dosage ratio of 0.06mol:20mL;

[0048] Step B2, 1.3g of phosphite derivative and 3.1g of potassium carbonate were mixed in 20mL of deionized water, and stirred at 45°C for 30min, then transferred to an ice water bath, and 80mL of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was slowly added dropwise. After the addition was completed, the mixture was reacted at room temperature for 10h, allowed to stand for 24h, and distilled under reduced pressure, washed, and dried to obtain a modified antioxidant. The β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was prepared by mixing and stirring β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride and benzene in a dosage ratio of 3.3g:80mL.

[0049] Embodiment 3: Antibacterial silicone oil is prepared by the following steps:

[0050] Step A1, 0.02 mol 1,5-dibromopentane and 3 g sodium hydroxide were evenly dispersed in 100 mL N,N-dimethylformamide, 0.02 mol 1-allylimidazole was added, and the mixture was stirred at room temperature for 24 h, and purified to obtain a brominated imidazole derivative;

[0051] Step A2, 1 g of nano zirconium phosphate, 0.1 g of carboxymethyl chitosan and 50 g of deionized water were mixed and stirred evenly, transferred to a ball mill (ball to material ratio of 2:1) and ball milled at a speed of 1000 m / min for 60 min, and the ball milled product was collected to obtain CMCS@ZrP;

[0052] Step A3, evenly dispersing 5 g of CMCS@ZrP in 100 mL of N,N-dimethylformamide, adding 4 g of a bromoimidazole derivative and 2.5 g of sodium hydroxide, stirring and reacting for 24 hours, centrifuging and purifying to obtain a composite antibacterial agent;

[0053] Step A4, mix 0.6g of the composite antibacterial agent, 9g of chloroplatinic acid isopropanol solution and 50mL of toluene, stir evenly, replace with nitrogen three times, slowly add 5g of hydrogen-containing silicone oil under nitrogen conditions, and heat to 90°C to react for 3h, and distill under reduced pressure to obtain antibacterial silicone oil. The mass ratio of chloroplatinic acid and isopropanol in the chloroplatinic acid isopropanol solution is 0.1:100.

[0054] The modified antioxidant is prepared by the following steps:

[0055] Step B1, 0.02 mol of 4-nitrophenol is evenly dispersed in 100 mL of carbon tetrachloride, 0.016 mol of triethylamine is added and stirred for 1 hour, then 20 mL of diphenyl phosphite carbon tetrachloride solution is slowly added dropwise in an ice-water bath, stirred at room temperature for 24 hours, extracted, washed, dried, distilled under reduced pressure, purified, and the product is collected; then 2.4 g of zinc powder, 30 mL of ethyl acetate and 30 mL of deionized water are added to 3 g of the product and mixed and stirred evenly, and then 4 g of ammonium chloride is added in 5 times (each time with an interval of 10 minutes), and the stirring is continued for 2.5 hours, and the phosphite derivative is obtained by suction filtration, extraction, drying, distillation under reduced pressure, and purification. The diphenyl phosphite carbon tetrachloride solution is prepared by mixing and stirring diphenyl phosphite and carbon tetrachloride in a dosage ratio of 0.08 mol: 20 mL;

[0056] Step B2, 1.7g of phosphite derivative and 4.14g of potassium carbonate were mixed in 20mL of deionized water, and stirred at 45°C for 30min, then transferred to an ice water bath, and 80mL of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was slowly added dropwise. After the addition was completed, the mixture was reacted at room temperature for 12h, allowed to stand for 24h, and distilled under reduced pressure, washed, and dried to obtain a modified antioxidant. The β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution was prepared by mixing and stirring β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride and benzene in a dosage ratio of 4.4g:80mL.

[0057] Embodiment 4: A method for preparing a multi-layer antibacterial silica gel protective film comprises the following steps:

[0058] 30 parts of vinyl silicone oil, 30 parts of MQ resin, 5 parts of the antibacterial silicone oil prepared in Example 1, 1 part of the modified antioxidant prepared in Example 1, 0.5 parts of dispersant, 60 parts of ethyl acetate, 0.5 parts of cross-linking agent, and 0.5 parts of catalyst;

[0059] Step S1, weighing raw materials by weight, mixing vinyl silicone oil and MQ resin in ethyl acetate and stirring evenly, then adding a crosslinking agent, the antibacterial silicone oil prepared in Example 1, the modified antioxidant prepared in Example 1, a dispersant and a catalyst and stirring evenly, and then filtering through a 300-mesh filter cloth to obtain functional silica gel;

[0060] Step S2, uniformly coating the functional silicone on one side of the PET anti-aging film to form a functional silicone layer, the film thickness is 5 μm, and then applying the PET release film on the functional silicone layer to form a release film layer, that is, a multi-layer antibacterial silicone protective film.

[0061] Embodiment 5: A method for preparing a multi-layer antibacterial silica gel protective film comprises the following steps:

[0062] 35 parts of vinyl silicone oil, 35 parts of MQ resin, 6 parts of the antibacterial silicone oil prepared in Example 2, 1.5 parts of the modified antioxidant prepared in Example 2, 1 part of dispersant, 80 parts of ethyl acetate, 1 part of cross-linking agent, and 1 part of catalyst;

[0063] Step S1, weighing raw materials by weight, mixing vinyl silicone oil and MQ resin in ethyl acetate and stirring evenly, then adding a crosslinking agent, the antibacterial silicone oil prepared in Example 2, the modified antioxidant prepared in Example 2, a dispersant and a catalyst and stirring evenly, and then filtering through a 400-mesh filter cloth to obtain functional silica gel;

[0064] Step S2, uniformly coating the functional silicone on one side of the PET anti-aging film to form a functional silicone layer, the film thickness is 6 μm, and then applying the PET release film on the functional silicone layer to form a release film layer, that is, a multi-layer antibacterial silicone protective film.

[0065] Embodiment 6: A method for preparing a multi-layer antibacterial silica gel protective film comprises the following steps:

[0066] 40 parts of vinyl silicone oil, 40 parts of MQ resin, 8 parts of the antibacterial silicone oil prepared in Example 3, 2 parts of the modified antioxidant prepared in Example 3, 2 parts of dispersant, 100 parts of ethyl acetate, 2 parts of crosslinking agent, and 2 parts of catalyst;

[0067] Step S1, weighing raw materials by weight, mixing vinyl silicone oil and MQ resin in ethyl acetate and stirring evenly, then adding a crosslinking agent, the antibacterial silicone oil prepared in Example 3, the modified antioxidant prepared in Example 3, a dispersant and a catalyst and stirring evenly, and then filtering through a 500-mesh filter cloth to obtain functional silica gel;

[0068] Step S2, uniformly coating the functional silicone on one side of the PET anti-aging film to form a functional silicone layer, the film thickness is 8 μm, and then applying the PET release film on the functional silicone layer to form a release film layer, that is, a multi-layer antibacterial silicone protective film.

[0069] Comparative Example 1: This comparative example is a silicone protective film. The difference from Example 6 is that hydrogen-containing silicone oil is used instead of the antibacterial silicone oil prepared in Example 3, and 3 parts of commercially available quaternary ammonium salt antibacterial agent are added, and the rest are the same.

[0070] Comparative Example 2: This comparative example is a silica gel protective film. The difference from Example 6 is that a commercially available antioxidant is used instead of the modified antioxidant prepared in Example 3, and the rest is the same.

[0071] The performance of the silicone protective films prepared in Examples 4-6 and Comparative Examples 1-2 was tested:

[0072] Antibacterial performance test: place the silicone protective film in the bacterial solution for 30 minutes, then place the bacterial solution in the glass plate, calculate the number of active bacteria in the bacterial solution, and calculate the antibacterial rate; Peel force test: stick the silicone protective film on the surface of the optical film, and use a peel force tester to test the silicone protective film. The test conditions are: 50N, 100mm / min, 90° peeling, unit g / in; Aging resistance test: stick the silicone protective film on the surface of the optical film and place it in an aging test box. The temperature is set to 85°C and the humidity is 85%. Place it for 24 hours, detect the peel force according to the steps of the peel force test, and calculate the change of the peel force before and after aging. Peel force change (%) = (peel force before aging-peel force after aging) / peel force before aging*100%; The test results are shown in Table 1:

[0073] Table 1: Performance test results

[0074]

[0075] As can be seen from Table 1, the silicone protective film prepared by the present invention has an antibacterial rate greater than 99.5% after antibacterial performance test, peeling force test and aging resistance test, the peeling force before aging is (2.48-2.71) g / in, the peeling force after aging is (2.36-2.61) g / in, and the peeling force changes in (3.69-4.84)%, indicating that the silicone protective film has excellent aging resistance and antibacterial properties.

[0076] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A multi-layer antibacterial silica gel protective film, characterized in that: From top to bottom, it includes a substrate layer, a functional silicone layer and a release film layer; the substrate layer is a PET anti-aging film; the functional silicone layer is prepared by coating the functional silicone on the surface of the PET anti-aging film; the release film layer is a PET release film; The functional silica gel comprises the following raw materials in parts by weight: 30-40 parts of vinyl silicone oil, 30-40 parts of MQ resin, 5-8 parts of antibacterial silicone oil, 1-2 parts of modified antioxidant, 0.5-2 parts of dispersant, 60-100 parts of ethyl acetate, 0.5-2 parts of crosslinking agent, and 0.5-2 parts of catalyst; The antibacterial silicone oil is prepared by the following steps: Step A1, 1,5-dibromopentane and sodium hydroxide are evenly dispersed in N,N-dimethylformamide, 1-allylimidazole is added, and the mixture is stirred at room temperature for 24 hours, and purified to obtain a brominated imidazole derivative; Step A2, mixing nano zirconium phosphate, carboxymethyl chitosan and deionized water, transferring to a ball mill and ball milling at a speed of 800-1000 m / min for 40-60 min, collecting the ball milling product, and obtaining CMCS@ZrP; Step A3, dispersing CMCS@ZrP evenly in N,N-dimethylformamide, adding bromoimidazole derivative and sodium hydroxide, stirring and reacting for 18-24 hours, centrifuging and purifying to obtain a composite antibacterial agent; Step A4, mix and stir the composite antibacterial agent, chloroplatinic acid isopropanol solution and toluene evenly, replace with nitrogen three times, slowly add hydrogen-containing silicone oil under nitrogen conditions, heat to 80-90°C and react for 2-3h, and distill under reduced pressure to obtain antibacterial silicone oil.

2. A multi-layer antibacterial silicone protective film according to claim 1, characterized in that: In step A1, the usage ratio of 1,5-dibromopentane, sodium hydroxide, N,N-dimethylformamide and 1-allylimidazole is 0.01-0.02 mol: 1.5-3 g: 100 mL: 0.01-0.02 mol.

3. The multi-layer antibacterial silica gel protective film according to claim 1, characterized in that: In step A2, the dosage ratio of nano zirconium phosphate, carboxymethyl chitosan and deionized water is 0.3-1g: 0.05-0.1g: 50g.

4. The multi-layer antibacterial silica gel protective film according to claim 1, characterized in that: In step A3, the usage ratio of CMCS@ZrP, N,N-dimethylformamide, bromoimidazole derivative and sodium hydroxide is 3-5 g:100 mL:2-4 g:1.2-2.5 g.

5. The multi-layer antibacterial silica gel protective film according to claim 1, characterized in that: In step A4, the dosage ratio of the composite antibacterial agent, chloroplatinic acid isopropanol solution, toluene and hydrogen-containing silicone oil is 0.3-0.6 g: 6-9 g: 50 mL: 2.5-5 g, and the mass ratio of chloroplatinic acid and isopropanol in the chloroplatinic acid isopropanol solution is 0.05-0.1:

100.

6. The multi-layer antibacterial silica gel protective film according to claim 1, characterized in that: The modified antioxidant is prepared by the following steps: Step B1, 4-nitrophenol is dispersed uniformly in carbon tetrachloride, triethylamine is added and stirred for 0.5-1h, then diphenyl phosphite carbon tetrachloride solution is slowly added dropwise in an ice-water bath, stirred at room temperature for 24h, extracted, washed, dried, distilled under reduced pressure, purified, and the product is collected; zinc powder, ethyl acetate and deionized water are added to the product and mixed and stirred uniformly, ammonium chloride is added in 5 times, stirring is continued for 1.5-2.5h, suction filtered, extracted, dried, distilled under reduced pressure, purified, and the phosphite derivative is obtained; Step B2, mix the phosphite derivative and potassium carbonate in deionized water, stir at 45°C for 30 minutes, transfer to an ice water bath, slowly dropwise add β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionylbenzene chloride solution, after the addition is completed, react at room temperature for 8-12 hours, stand for 24 hours, distill under reduced pressure, wash, and dry to obtain a modified antioxidant.

7. The multi-layer antibacterial silica gel protective film according to claim 6, characterized in that: The amount ratio of 4-nitrophenol, carbon tetrachloride, triethylamine and diphenyl phosphite carbon tetrachloride solution in the product of step B1 is 0.01-0.02 mol:100 mL:0.008-0.016 mol:20 mL, and the diphenyl phosphite carbon tetrachloride solution is prepared by mixing and stirring diphenyl phosphite and carbon tetrachloride in an amount ratio of 0.04-0.08 mol:20 mL.

8. The multi-layer antibacterial silica gel protective film according to claim 6, characterized in that: The usage ratio of the product, zinc powder, ethyl acetate, deionized water and ammonium chloride in step B1 is 1.5-3 g: 1.2-2.4 g: 30 mL: 30 mL: 2-4 g.

9. The multi-layer antibacterial silica gel protective film according to claim 6, characterized in that: In step B2, the amount ratio of the phosphite derivative, potassium carbonate, deionized water and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution is 0.85-2.5 g: 2.07-4.14 g: 20 mL: 80 mL, and the β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride benzene solution is prepared by mixing and stirring β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride and benzene in an amount ratio of 2.2-4.4 g: 80 mL.

10. A method for preparing the multi-layer antibacterial silica gel protective film according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, weighing raw materials by weight, mixing vinyl silicone oil and MQ resin in ethyl acetate and stirring evenly, then adding a crosslinking agent, antibacterial silicone oil, modified antioxidant, dispersant and catalyst and stirring evenly, and then filtering through a 300-500 mesh filter cloth to obtain functional silica gel; Step S2, uniformly coating the functional silicone on one side of the PET anti-aging film to form a functional silicone layer, the thickness of the film is 5-8 μm, and then applying the PET release film on the functional silicone layer to form a release film layer, that is, a multi-layer antibacterial silicone protective film.

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