Heat-insulating high-transmittance polyester film and application thereof

Abstract

The invention discloses a heat-insulating high-transmittance polyester film and application thereof. The heat-insulating high-transmittance polyester film comprises a polyester base layer and a barrier layer arranged on the surface of the polyester base layer. The invention also provides a preparation method, which comprises the following steps: firstly preparing a biaxially oriented polyester film as the polyester base layer, and then coating the polyester base layer subjected to corona treatment with a barrier liquid composed of a cycloolefin copolymer and lanthanum hexaboride nanoparticles by adopting a blade coating method so as to form the barrier layer on the polyester base layer. And then preparing the heat-insulating high-transmittance polyester film through high-temperature mold pressing. Compared with the prior art, the polyester film prepared by the preparation method disclosed by the invention has the characteristics of high transparency and excellent heat insulation effect, and the problem of ultraviolet aging resistance is further improved, so that the polyester film with excellent ultraviolet resistance, tensile property and barrier property is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyester film, in particular to a heat-insulating high-transparency polyester film and application thereof. BACKGROUND

[0002] Polyethylene terephthalate (PET) material has excellent comprehensive performance, so PET film is widely used in packaging, textile, electronics, photovoltaic and other fields. However, the heat insulation and light transmission performance of PET film still needs to be improved, especially the heat insulation effect of the film exposed to the outdoor is very poor, and in the high wave band of the spectral range, the light transmission performance is limited by the refractive index and scattering characteristics of the material. Therefore, it is necessary to modify the PET film material to obtain a polyester film with excellent heat insulation performance and high transparency.

[0003] Chinese patent CN118374041A discloses a high-heat-insulation high-transparency PET optical film and a preparation method thereof. The film comprises the following components by mass percentage: PET resin 60-80%, heat insulation master batch 10-20%, light stabilizer 0.5-2%, slip agent 0.1-0.5%, dispersing agent 0.5-5%, antioxidant 1-5%, and light transmission coating 7.5-8%. The preparation of the heat insulation master batch as raw material for the PET film significantly improves the heat resistance of the PET film. In addition, the preparation of the high-transparency coating and the coating on the film enhance the light transmission of the PET film. However, the PET optical film has poor ultraviolet aging resistance, which is not conducive to long-term use. SUMMARY

[0004] In view of the above-mentioned defects of the prior art, the present application provides a heat-insulating high-transparency polyester film which has excellent heat insulation effect while maintaining high transparency, and further improves the ultraviolet aging resistance to obtain a polyester film with excellent ultraviolet resistance, tensile properties and barrier properties.

[0005] To achieve the above-mentioned purpose, the present application provides a heat-insulating high-transparency polyester film, which comprises a polyester base layer and a barrier layer arranged on the surface of the polyester base layer. The barrier layer is formed by coating a barrier liquid on the surface of the polyester base layer. The polyester base layer is a biaxially oriented polyester film. The biaxially oriented polyester film is added with loaded TiO2 sporopollenin or modified loaded TiO2 sporopollenin.

[0006] Preferably, the preparation method of the barrier liquid comprises the following steps, by weight: 8-12 parts by weight of the cycloolefin copolymer is added into 45-55 parts by weight of a xylene solution to mix until completely dissolved, to obtain a cycloolefin copolymer solution; 0.1-0.6 parts by weight of lanthanum hexaboride nanoparticles is added into 45-55 parts by weight of a xylene solution to mix until completely dissolved, to obtain a lanthanum hexaboride solution; then the lanthanum hexaboride solution is added into the cycloolefin copolymer solution to mix and stir for 20-40 min, to form a barrier solution.

[0007] Preferably, the preparation method of the biaxially stretched polyester film comprises the following steps: The raw material components are weighed by parts by weight: PET resin 60-80 parts, polyglycolic acid 10-20 parts, auxiliary agent 1-2 parts, stabilizer 1-3 parts, dispersing agent 1-5 parts; then the PET resin and polyglycolic acid are dried to obtain dried PET resin and polyglycolic acid, the dried PET resin and polyglycolic acid are mixed, then the auxiliary agent, the stabilizer, and the dispersing agent are added and uniformly mixed, and then sent into a double-screw extruder to melt and extrude to form a melt film, and then the melt film is cast on a cooling roller through a casting die to cool, to form a cast sheet, and then the biaxially stretched polyester film is obtained after transverse stretching and longitudinal stretching, heat setting, and cooling.

[0008] Preferably, the auxiliary agent is selected from one of loaded TiO2 spore powder microcapsules and modified loaded TiO2 spore powder microcapsules.

[0009] Preferably, the preparation method of the loaded TiO2 spore powder microcapsules comprises the following steps, by parts by weight: 9-11 parts of spore powder microcapsules are dispersed in 480-520 parts of anhydrous ethanol, ultrasonic treatment is performed for 20-30 min, centrifugation is performed at 6000-10000 rpm for 5-12 min, the precipitate is collected and dried to obtain pretreated spore powder microcapsules; 5.7-5.9 parts of the pretreated spore powder microcapsules are added into 48-52 parts of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:4-6, stirring is performed for 20-35 min, 4-6 parts of a nitric acid aqueous solution is added dropwise at a constant temperature of 58-62℃, and then the reaction is continued at 58-62℃ for 5-8 h; the reaction solution is centrifuged at 8000 rpm for 10 min, the precipitate is collected, washed with ethanol and water for 4-5 times, and vacuum dried at 58-62℃ to obtain the loaded TiO2 spore powder microcapsules.

[0010] Preferably, the preparation method of the modified loaded TiO2 spore powder microcapsules comprises the following steps, by parts by weight: Preparation of the modified TiO2-loaded spores microcapsule: 9-11 parts of spores microcapsule were dispersed in 480-520 parts of anhydrous ethanol, and ultrasonic treatment was performed for 20-30 min. Centrifugation was performed at 6000-10000 rpm for 5-12 min, and the precipitate was collected and dried to obtain pretreated spores microcapsule. 5.7-5.9 parts of the pretreated spores microcapsule were added to 48-52 parts of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:4-6, and stirring was performed for 20-35 min. 4-6 parts of nitric acid aqueous solution was added dropwise at a constant temperature of 58-62 ℃, and then the reaction was continued at 58-62 ℃ for 5-8 h. The reaction solution was centrifuged at 8000 rpm for 10 min, and the precipitate was collected and washed with ethanol and water for 4-5 times, respectively, and dried at 58-62 ℃ under vacuum to obtain the TiO2-loaded spores microcapsule. 0.9-1.1 parts of the TiO2-loaded spores microcapsule were dispersed in 48-52 parts of anhydrous N,N-dimethylformamide, and ultrasonic treatment was performed for 20-35 min. Then, 0.4-0.6 parts of a modifier, 0.03-0.1 parts of N,N'-dicyclohexyl carbodiimide and 0.01-0.06 parts of 4-dimethylamino pyridine were added, and mixing reaction was performed at 58-62 ℃ under nitrogen protection for 10-13 h. The reaction solution was centrifuged at 6000-9000 rpm for 8-12 min, and the precipitate was collected and washed with anhydrous N,N-dimethylformamide, ethanol and water for 2-3 times, respectively, and dried at 58-62 ℃ under vacuum to obtain the modified TiO2-loaded spores microcapsule.

[0011] Preferably, the modifier is selected from one of gallic acid, chlorogenic acid and ginkgo acid.

[0012] Further description of the present application, the TiO2 inorganic nanomaterial has good absorption of ultraviolet characteristics, often as inorganic ultraviolet absorber added to the preparation process of polyester film to achieve the purpose of protecting the material. However, the amount of inorganic nanomaterial will affect the transparency of polyester film, adding a small amount of inorganic ultraviolet absorber although can improve its ultraviolet resistance without affecting the film transparency premise, but the amount is too low, the ultraviolet absorption efficiency is not high, can not meet the requirements of the polyester film under long-term ultraviolet irradiation of ultraviolet protection, and a large number of filling inorganic nanometer powder although can further improve the ultraviolet resistance of the film, but the nanometer powder is difficult to disperse uniformly in the polyester matrix, will affect the transparency and light transmittance of the film, can not get the polyester film with high trans characteristics. Based on this, the present application prepares the TiO2-loaded spores microcapsule, which is introduced into the preparation process of polyester film as an aid, which can significantly improve the ultraviolet aging resistance without affecting the high trans characteristics of polyester film. And on the basis of the TiO2-loaded spores microcapsule, the modifier is introduced to further chemically modify the TiO2-loaded spores microcapsule to prepare the modified TiO2-loaded spores microcapsule, so that the prepared polyester film has excellent tensile properties, ultraviolet resistance and barrier properties.

[0013] In the preparation process of the modified supported TiO2 sporopollenin microcapsules, the sporopollenin microcapsules are pretreated by ultrasonic treatment, and then the pretreated sporopollenin microcapsules are added to a mixed solution of tetrabutyl titanate and ethanol to generate a sol-gel reaction, and the generated TiO2 sol is gradually deposited in the porous structure of the sporopollenin microcapsules to prepare the supported TiO2 sporopollenin microcapsules; on this basis, gallic acid, chlorogenic acid and ginkgo acid are introduced as modifiers to further modify the supported TiO2 sporopollenin microcapsules, and under the catalysis of dicyclohexyl carbodiimide and 4-dimethylaminopyridine, the carboxyl and phenolic hydroxyl groups in the modifier structure react with the free hydroxyl or carboxyl groups on the surface of the supported TiO2 sporopollenin microcapsules, so that the modifier is grafted on the surface of the sporopollenin microcapsules, thereby preparing the modified supported TiO2 sporopollenin microcapsules.

[0014] Preferably, the stabilizer is selected from at least one of calcium stearate, triphenyl phosphate, and trimethyl phosphate.

[0015] Preferably, the dispersant is selected from at least one of polyethylene wax, paraffin wax, and ethylene bisoleic acid amide.

[0016] The application also provides a preparation method of the high-transparency polyester film, comprising the following steps: The barrier liquid is applied to the polyester base layer after the corona treatment by using the blade coating method, so as to form a barrier layer on the polyester base layer; then the polyester base layer is dried in an oven at 90-110 DEG C for 10-14 h, and then treated at a high temperature of 150-200 DEG C for 0.5-2 h, and then molded in a laminating machine at 150-160 DEG C for 8-13 min, so as to form the heat-insulating high-transparency polyester film composed of the barrier layer and the polyester base layer; wherein the coating amount of the barrier liquid is 1-1.4 g / m 2 ; and the thickness of the formed heat-insulating high-transparency polyester film is 20-25 mu m.

[0017] The application also provides an application of the high-transparency polyester film, and the high-transparency polyester film can be used for preparing product packaging of daily chemical products, medicines, and food.

[0018] The application has the following beneficial effects: 1. Compared with the prior art, the bidirectional stretching polyester film is prepared as a polyester base layer, then the barrier liquid composed of cyclic olefin copolymer and lanthanum hexaboride nanoparticles is applied to the polyester base layer after the corona treatment by using the blade coating method, so as to form a barrier layer on the polyester base layer, and then the heat-insulating high-transparency polyester film is prepared by high-temperature molding. The heat-insulating high-transparency polyester film prepared by scientific proportioning and optimization of the preparation conditions has the high-transparency characteristic, and also has excellent heat-insulating effect, thereby expanding the application field.

[0019] 2、The application introduces the loaded TiO2 sporopollens microcapsule or the modified loaded TiO2 sporopollens microcapsule as an auxiliary agent in the biaxially oriented polyester film, which not only solves the problem of easy agglomeration and difficult dispersion of the inorganic ultraviolet absorber TiO2 in the polyester matrix, but also significantly improves the ultraviolet aging resistance of the polyester film while ensuring the high transparency of the polyester film, and effectively improves the tensile property, barrier property and antibacterial property of the film. DETAILED DESCRIPTION

[0020] Parameters for using specific chemicals, sources.

[0021] PET resin, brand: PET530, brand: Yehong new material; Polyglycolic acid, molecular weight: 30KDa; TiO2 nano powder, particle size: 10nm, model: DK-TiO2-A10, from Beijing Dekedao Gold Technology Co., Ltd.; Lanthanum hexaboride nanoparticles, particle size: 10nm, Cycloolefin copolymer, model: 6013S-04, brand: Germany TOPAS; Ginkgo acid, C15:1, CAS number: 22910-60-7; Chlorogenic acid, CAS number: 327-97-9; The preparation method of the sporopollens microcapsule is as follows: lycopodium spores (100 mesh, Waters) and acetone are mixed in a weight ratio of 1:10, reflux stirring at 50℃ for 2h, filtering, and the filter cake is washed with ethanol and water in turn until the filtrate is clear, and then dried to obtain a crude product; 10g of the crude product is mixed with 200mL of 0.2g / mL phosphoric acid aqueous solution, reflux stirring at 75℃ for 8h, then filtering, washing with water and drying to obtain sporopollens microcapsules.

[0022] Example 1 A preparation method of a heat-insulating high-transparency polyester film, comprising the following steps: The upward surface of the polyester base layer is subjected to corona treatment by a corona machine, the power of the corona machine is 5KW, and the speed of the corona machine is 80m / min, so that the surface tension value of the polyester base layer reaches 38 dynes, wherein the polyester base layer is a biaxially oriented polyester film; then a barrier liquid is coated on the surface of the polyester base layer subjected to corona treatment by a doctor blade method, so as to form a barrier layer on the polyester base layer, wherein the coating amount of the barrier liquid is 1.2g / m 2 ; then the polyester base layer is introduced into an oven by a traction roller, dried at 100℃ for 12h, and then treated at a high temperature of 180℃ for 1h, and then placed into a laminating machine, and molded at 155℃ for 10min, to form a heat-insulating high-transparency polyester film composed of a barrier layer and a polyester base layer; the thickness of the heat-insulating high-transparency polyester film is 23μm.

[0023] The preparation method of the barrier liquid comprises the following steps: 10 parts by weight of the cycloolefin copolymer was added into 50 parts by weight of a dimethylbenzene solution and mixed until completely dissolved to obtain a cycloolefin copolymer solution; 0.5 parts by weight of lanthanum hexaboride nanoparticles was added into 50 parts by weight of a dimethylbenzene solution and mixed until completely dissolved to obtain a lanthanum hexaboride solution; then the lanthanum hexaboride solution was added into the cycloolefin copolymer solution and mixed and stirred for 30 min to form the barrier liquid.

[0024] The polyester-based layer is a biaxially stretched polyester film, and the preparation method thereof comprises the following steps: 78 parts by weight of PET resin, 17 parts by weight of polyglycolic acid, 1.5 parts by weight of TiO2-loaded spores microcapsules, 2.5 parts by weight of trimethyl phosphate, and 4 parts by weight of ethylene bisoleic acid amide were weighed; then the PET resin and the polyglycolic acid were dried to obtain dried PET resin and polyglycolic acid, the dried PET resin and polyglycolic acid were mixed, and then the TiO2-loaded spores microcapsules, trimethyl phosphate, and ethylene bisoleic acid amide were added and uniformly mixed, and then fed into a twin-screw extruder for melt extrusion to form a melt film, the screw rotation speed was 400 rpm, and the melt temperature was 270℃; the melt film was then cast on a cooling roller through a casting die to be cooled, the cooling temperature was 30℃, a cast sheet was formed, and then the biaxially stretched polyester film was obtained after transverse stretching and longitudinal stretching, heat setting, and cooling; wherein the stretching temperature was 140℃, the transverse stretching multiple was 4 times, the longitudinal stretching multiple was 4 times, and the heat setting temperature was 230℃.

[0025] The preparation method of the TiO2-loaded spores microcapsules comprises the following steps: 10 parts by weight of spores microcapsules were dispersed in 500 parts by weight of anhydrous ethanol, ultrasonically treated for 30 min, centrifuged at 8000 rpm for 10 min, the precipitate was collected and dried to obtain pretreated spores microcapsules; 5.8 parts by weight of the pretreated spores microcapsules were added into 50 parts by weight of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:5 and stirred for 30 min, 5 parts by weight of 0.1 mol / L nitric acid aqueous solution was added dropwise at 60℃ under constant temperature conditions through a constant pressure dropping funnel, and the dropping was completed within 30 min, the pH of the reaction system was controlled at 3, and the reaction was continued at 60℃ for 6 h; the reaction liquid was centrifuged at 8000 rpm for 10 min, the precipitate was collected and washed with ethanol and water for 5 times, and vacuum dried at 60℃ to obtain the TiO2-loaded spores microcapsules.

[0026] Example 2 A preparation method of a heat-insulating high-transparency polyester film, which is different from that of Example 1 in that the preparation method of the biaxially stretched polyester film comprises the following steps: Take 78 parts by weight of PET resin, 17 parts by weight of polyglycolic acid, 1.5 parts by weight of modified supported TiO2 sporopollenin microcapsule, 2.5 parts by weight of trimethyl phosphate, and 4 parts by weight of ethylene bisoleic acid amide; then dry the PET resin and polyglycolic acid to obtain dried PET resin and polyglycolic acid, mix the dried PET resin and polyglycolic acid, then add the modified supported TiO2 sporopollenin microcapsule, trimethyl phosphate, and ethylene bisoleic acid amide, mix them uniformly, and then send them into a twin-screw extruder for melt extrusion to form a melt film; the screw rotation speed is 400 rpm, and the melt temperature is 270℃; then the melt film is cast on a cooling roller through a casting die for cooling; the cooling temperature is 30℃; a cast sheet is formed; and after transverse stretching and longitudinal stretching, heat setting, and cooling, a biaxially stretched polyester film is obtained; wherein the stretching temperature is 140℃, the transverse stretching multiple is 4, and the longitudinal stretching multiple is 4; and the heat setting temperature is 230℃.

[0027] The preparation method of the modified supported TiO2 sporopollenin microcapsule comprises the following steps: Disperse 10 parts by weight of sporopollenin microcapsule in 500 parts by weight of anhydrous ethanol, ultrasonically treat for 30 min, centrifuge at 8000 rpm for 10 min, collect the precipitate, and dry to obtain pretreated sporopollenin microcapsule; add 5.8 parts by weight of the pretreated sporopollenin microcapsule to 50 parts by weight of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:5, stir for 30 min, add 5 parts by weight of 0.1 mol / L nitric acid aqueous solution dropwise at 60℃ under constant temperature conditions through a constant pressure dropping funnel, and control the dropping to be completed within 30 min; control the pH of the reaction system to be 3, and continue to react at 60℃ for 6 h; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with ethanol and water for 5 times in sequence, and dry at 60℃ under vacuum to obtain the supported TiO2 sporopollenin microcapsule; disperse 1 part by weight of the supported TiO2 sporopollenin microcapsule in 50 parts by weight of anhydrous N,N-dimethylformamide, ultrasonically treat for 30 min, then add 0.5 parts by weight of gallic acid, 0.08 parts by weight of N,N'-dicyclohexyl carbodiimide, and 0.05 parts by weight of 4-dimethylamino pyridine, mix and react at 60℃ for 12 h under nitrogen protection; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with anhydrous N,N-dimethylformamide, ethanol, and water for 3 times in sequence, and dry at 60℃ under vacuum to obtain the modified supported TiO2 sporopollenin microcapsule.

[0028] Example 3 A preparation method of a heat-insulating high-transparency polyester film, which is different from example 1 in that the preparation method of the biaxially stretched polyester film comprises the following steps: Take 78 parts by weight of PET resin, 17 parts by weight of polyglycolic acid, 1.5 parts by weight of modified supported TiO2 sporopollenin microcapsule, 2.5 parts by weight of trimethyl phosphate, and 4 parts by weight of ethylene bisoleic acid amide; then dry the PET resin and polyglycolic acid to obtain dried PET resin and polyglycolic acid, mix the dried PET resin and polyglycolic acid, then add the modified supported TiO2 sporopollenin microcapsule, trimethyl phosphate, and ethylene bisoleic acid amide, mix them uniformly, and then send them into a twin-screw extruder for melt extrusion to form a melt film; the screw rotation speed is 400 rpm, and the melt temperature is 270℃; then the melt film is cast on a cooling roller through a casting die for cooling; the cooling temperature is 30℃; a cast sheet is formed; and after transverse stretching and longitudinal stretching, heat setting, and cooling, a biaxially stretched polyester film is obtained; wherein the stretching temperature is 140℃, the transverse stretching multiple is 4, the longitudinal stretching multiple is 4, and the heat setting temperature is 230℃.

[0029] The preparation method of the modified supported TiO2 sporopollenin microcapsule comprises the following steps: Disperse 10 parts by weight of sporopollenin microcapsule in 500 parts by weight of anhydrous ethanol, ultrasonically treat for 30 min, centrifuge at 8000 rpm for 10 min, collect the precipitate, and dry to obtain pretreated sporopollenin microcapsule; add 5.8 parts by weight of the pretreated sporopollenin microcapsule to 50 parts by weight of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:5, stir for 30 min, add 5 parts by weight of 0.1 mol / L nitric acid aqueous solution dropwise at 60℃ under constant temperature conditions through a constant pressure dropping funnel, and control the dropping to be completed within 30 min; control the pH of the reaction system to be 3, and continue to react at 60℃ for 6 h; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with ethanol and water for 5 times in sequence, and dry at 60℃ under vacuum to obtain the supported TiO2 sporopollenin microcapsule; disperse 1 part by weight of the supported TiO2 sporopollenin microcapsule in 50 parts by weight of anhydrous N,N-dimethylformamide, ultrasonically treat for 30 min, then add 0.5 parts by weight of chlorogenic acid, 0.08 parts by weight of N,N'-dicyclohexyl carbodiimide, and 0.05 parts by weight of 4-dimethylamino pyridine, mix at 60℃ under nitrogen protection for 12 h; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with anhydrous N,N-dimethylformamide, ethanol, and water for 3 times in sequence, and dry at 60℃ under vacuum to obtain the modified supported TiO2 sporopollenin microcapsule.

[0030] Example 4 A preparation method of a heat-insulating high-transparency polyester film, which is different from that of example 1, comprises the following steps: Take 78 parts by weight of PET resin, 17 parts by weight of polyglycolic acid, 1.5 parts by weight of modified supported TiO2 sporopollenin microcapsule, 2.5 parts by weight of trimethyl phosphate, and 4 parts by weight of ethylene bisoleic acid amide; then dry the PET resin and polyglycolic acid to obtain dried PET resin and polyglycolic acid, mix the dried PET resin and polyglycolic acid, then add the modified supported TiO2 sporopollenin microcapsule, trimethyl phosphate, and ethylene bisoleic acid amide, mix them uniformly, and then send them into a twin-screw extruder for melt extrusion to form a melt film; the screw rotation speed is 400 rpm, and the melt temperature is 270℃; then the melt film is cast on a cooling roller through a casting die for cooling; the cooling temperature is 30℃; a cast sheet is formed; and after transverse stretching and longitudinal stretching, heat setting, and cooling, a biaxially stretched polyester film is obtained; wherein the stretching temperature is 140℃, the transverse stretching multiple is 4, and the longitudinal stretching multiple is 4; and the heat setting temperature is 230℃.

[0031] The preparation method of the modified supported TiO2 sporopollenin microcapsule comprises the following steps: Disperse 10 parts by weight of sporopollenin microcapsule in 500 parts by weight of anhydrous ethanol, ultrasonically treat for 30 min, centrifuge at 8000 rpm for 10 min, collect the precipitate, and dry to obtain pretreated sporopollenin microcapsule; add 5.8 parts by weight of the pretreated sporopollenin microcapsule to 50 parts by weight of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:5, stir for 30 min, add 5 parts by weight of 0.1 mol / L nitric acid aqueous solution dropwise at 60℃ under constant temperature conditions through a constant pressure dropping funnel, and control the dropping to be completed within 30 min; control the pH of the reaction system to be 3, and continue to react at 60℃ for 6 h; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with ethanol and water for 5 times in sequence, and dry at 60℃ under vacuum to obtain the supported TiO2 sporopollenin microcapsule; disperse 1 part by weight of the supported TiO2 sporopollenin microcapsule in 50 parts by weight of anhydrous N,N-dimethylformamide, ultrasonically treat for 30 min, then add 0.5 parts by weight of ginkgo acid, 0.08 parts by weight of N,N'-dicyclohexyl carbodiimide, and 0.05 parts by weight of 4-dimethylamino pyridine, mix and react at 60℃ for 12 h under nitrogen protection; centrifuge the reaction solution at 8000 rpm for 10 min, collect the precipitate, wash it with anhydrous N,N-dimethylformamide, ethanol, and water for 3 times in sequence, and dry at 60℃ under vacuum to obtain the modified supported TiO2 sporopollenin microcapsule.

[0032] Comparative Example 1 A preparation method of a heat-insulating high-transparency polyester film, which is different from that of Example 1, comprises the following steps: PET resin 78 parts by weight, polyglycolic acid 17 parts by weight, modified TiO2 1.5 parts by weight, trimethyl phosphate 2.5 parts by weight, ethylene bisoleic acid amide 4 parts by weight are weighed; then the PET resin and polyglycolic acid are dried to obtain dried PET resin and polyglycolic acid, the dried PET resin and polyglycolic acid are mixed, then the modified TiO2, trimethyl phosphate and ethylene bisoleic acid amide are added and uniformly mixed, and then sent into a double screw extruder for melt extrusion to form a melt film, the screw rotation speed is 400 rpm, the melt temperature is 270℃, and then the melt film is cast on a cooling roller through a casting die for cooling, the cooling temperature is 30℃, a cast sheet is formed, and then a biaxially stretched polyester film is obtained after transverse stretching and longitudinal stretching, heat setting and cooling; wherein the stretching temperature is 140℃, the transverse stretching multiple is 4 times, the longitudinal stretching multiple is 4 times, and the heat setting temperature is 230℃.

[0033] The preparation method of the modified TiO2 includes the following steps: 10 parts by weight of TiO2 nano powder, 50 parts by weight of anhydrous ethanol and 10 parts by weight of water are mixed, ultrasonic dispersion is performed for 30 min to obtain a TiO2 suspension; then 5 parts by weight of KH-570 is mixed with 10 parts by weight of anhydrous ethanol and added dropwise into the above TiO2 suspension within 5 min, stirred uniformly, and refluxed in a 60℃ water bath for 4 h; then centrifuged at 8000 rpm for 10 min, washed with ethanol for 3 times, and placed in a 80℃ vacuum dryer for 12 h to obtain the modified TiO2.

[0034] Comparative Example 2 A preparation method of a heat-insulating high-transparency polyester film, which is different from that of Example 1, includes the following steps: PET resin 78 parts by weight, polyglycolic acid 17 parts by weight, TiO2 nano powder 1.5 parts by weight, trimethyl phosphate 2.5 parts by weight, ethylene bisoleic acid amide 4 parts by weight are weighed; then the PET resin and polyglycolic acid are dried to obtain dried PET resin and polyglycolic acid, the dried PET resin and polyglycolic acid are mixed, then the TiO2 nano powder, trimethyl phosphate and ethylene bisoleic acid amide are added and uniformly mixed, and then sent into a double screw extruder for melt extrusion to form a melt film, the screw rotation speed is 400 rpm, the melt temperature is 270℃, and then the melt film is cast on a cooling roller through a casting die for cooling, the cooling temperature is 30℃, a cast sheet is formed, and then a biaxially stretched polyester film is obtained after transverse stretching and longitudinal stretching, heat setting and cooling; wherein the stretching temperature is 140℃, the transverse stretching multiple is 4 times, the longitudinal stretching multiple is 4 times, and the heat setting temperature is 230℃.

[0035] Comparative Example 3 A method for preparing a heat-insulating high-transparency polyester film, which differs from Example 1 in that the method for preparing the biaxially-stretched polyester film comprises the following steps: PET resin 78 parts by weight, polyglycolic acid 17 parts by weight, trimethyl phosphate 2.5 parts by weight, and ethylene bis-oleic acid amide 4 parts by weight were weighed out, and the PET resin and the polyglycolic acid were then dried to obtain dried PET resin and polyglycolic acid. The dried PET resin and polyglycolic acid were mixed, and then the trimethyl phosphate and the ethylene bis-oleic acid amide were added and mixed uniformly. The mixture was then fed into a twin-screw extruder to be melt-extruded into a melt film, with a screw rotation speed of 400 rpm and a melt temperature of 270°C. The melt film was then cast onto a cooling roller via a casting die to be cooled, with a cooling temperature of 30°C, to form a cast sheet. The cast sheet was then subjected to transverse stretching and longitudinal stretching, heat setting, and cooling to obtain a biaxially-stretched polyester film. The stretching temperature was 140°C, the transverse stretching multiple was 4, the longitudinal stretching multiple was 4, and the heat setting temperature was 230°C.

[0036] Comparative Example 4 A method for preparing a polyester film, which comprises the following steps: PET resin 78 parts by weight, polyglycolic acid 17 parts by weight, modified TiO2-loaded spores microcapsules 1.5 parts by weight, trimethyl phosphate 2.5 parts by weight, and ethylene bis-oleic acid amide 4 parts by weight were weighed out, and the PET resin and the polyglycolic acid were then dried to obtain dried PET resin and polyglycolic acid. The dried PET resin and polyglycolic acid were mixed, and then the modified TiO2-loaded spores microcapsules, the trimethyl phosphate, and the ethylene bis-oleic acid amide were added and mixed uniformly. The mixture was then fed into a twin-screw extruder to be melt-extruded into a melt film, with a screw rotation speed of 400 rpm and a melt temperature of 270°C. The melt film was then cast onto a cooling roller via a casting die to be cooled, with a cooling temperature of 30°C, to form a cast sheet. The cast sheet was then subjected to transverse stretching and longitudinal stretching, heat setting, and cooling to obtain a polyester film with a thickness of 23 μm. The stretching temperature was 140°C, the transverse stretching multiple was 4, the longitudinal stretching multiple was 4, and the heat setting temperature was 230°C.

[0037] The method for preparing the modified TiO2-loaded spores microcapsules was the same as in Example 4.

[0038] Test Example 1 Anti-ultraviolet performance Before the xenon lamp aging test, the high-transparency polyester films prepared from Examples 1-4 and Comparative Examples 1-3 were selected as film samples, and the tensile properties of the film samples of each example and comparative example were tested according to the standard of GB / T 1040.3-2006, using a double-column bench universal testing machine. The film samples to be tested were cut into 1B dumbbell-shaped samples; the test conditions were: room temperature tensile, tensile rate of 10 mm / min, each group of samples was tested 5 times and the average value was taken; Then the xenon lamp aging test was carried out, and the test method was carried out according to the method A of Table 3 in GB / T16422.2-2014, i.e. dry for 102 min, then spray for 18 min, and cycle alternately; the broadband (300-400 nm) irradiance under dry-wet cycle was (60±2) W / m 2 ; the narrowband (340 nm) irradiance under dry-wet cycle was (0.51±) 0.02 W / (m 2 ·nm); the black label temperature of dry cycle was controlled at (65±3) ℃, the test box temperature was controlled at (38±3) ℃, the relative humidity was controlled at 50%±10%, and the total time was 600 h; after the test was completed, the test was carried out again according to the above tensile property test method, and the tensile strength of the high-transparency polyester film sample before and after aging was recorded; the test results are shown in Table 1; Barrier property Pure PET film and heat-insulating high-transparency polyester film prepared from Examples 1-4 and Comparative Examples 1-3 of the application were selected as test sample films, and water vapor transmission coefficient and oxygen transmission coefficient of each test sample film were tested by using water vapor transmission rate test system and oxygen transmission rate test system respectively; according to ASTM D1653 standard, the test conditions of water vapor transmission coefficient (WVP) were 90 RH% relative humidity, 1 atm and 38 ℃; according to YBB00082003-2015, the test conditions of oxygen transmission coefficient (OP) were 50% relative humidity, 1 atm and 23 ℃; the water vapor transmission coefficient and oxygen transmission coefficient of pure PET and each group of film were recorded, and the change rate of water vapor transmission coefficient and oxygen transmission coefficient of heat-insulating high-transparency polyester film prepared from Examples 1-4 and Comparative Examples 1-3 of the application compared with pure PET film was calculated according to the following formula (if the value is positive, it means that the water vapor transmission coefficient and oxygen transmission coefficient of heat-insulating high-transparency polyester film decrease compared with pure PET film, the larger the value, the more obvious the decrease; if the value is negative, it is the opposite); 3 parallel experiments were set, and the test data was averaged; Water vapor transmission change rate=(W0−W) / W0×100% In the formula, W0 is the water vapor transmission coefficient of pure PET, unit cm3 cm / (cm 2 s*Pa); W is the water vapor transmission coefficient of each sample, in cm 3 cm / (cm 2 s*Pa); Water vapor transmission rate change = (O0- O) / O0*100% In the formula, O0is the oxygen transmission coefficient of pure PET, in cm 3 cm / (cm 2 s*Pa); O is the oxygen transmission coefficient of each sample, in cm 3 cm / (cm 2 s*Pa); The test results are shown in Table 1; Antibacterial property test The high-transparency polyester films prepared from Examples 1-4 and Comparative Examples 1-3 were taken as film samples, and the antibacterial properties of the high-transparency polyester film samples were tested according to the test method provided in the standard of GB / T 31402-2015 Plastics-Test method for antibacterial property of plastics surface; experimental bacteria: Escherichia coli (commercial, ATCC 8739), Staphylococcus aureus (commercial, ATCC 6538P); 5 parallel experiments were set up for each group of samples, and the test results were averaged; The test results are shown in Table 1; From Table 1, it can be seen that comparative examples 1-4 and comparative examples 1-3 find that the tensile strength of examples 1-4 is significantly higher than that of comparative examples 1-3, the decrease rate of tensile strength after the xenon lamp aging test is significantly lower than that of comparative examples 1-3, and the vapor transmission rate change and oxygen transmission rate change are higher than those of comparative examples 1-3, indicating that compared with high-transparency polyester film without adding additives and using modified TiO2 and TiO2 nano powder as additives, introducing loaded TiO2 spores microcapsules and modified loaded TiO2 spores microcapsules as additives is more conducive to improving the tensile properties, ultraviolet resistance and barrier properties of high-transparency polyester film. The reason may be that compared with not adding additives and using modified TiO2 and TiO2 nano powder, the loaded TiO2 spores microcapsules can effectively prevent the agglomeration of TiO2 nano particles, have better dispersibility and interfacial compatibility, thereby effectively improving the tensile properties and ultraviolet resistance of the biaxially oriented polyester film, and the uniformly dispersed TiO2 can form a physical barrier layer to hinder the transmission of water vapor and oxygen, thereby significantly reducing the water vapor transmission coefficient and oxygen transmission coefficient and improving the barrier properties. Comparative examples 1-4 find that the tensile strength of examples 2-4 is significantly higher than that of example 1, the decrease rate of tensile strength after the xenon lamp aging test is significantly lower than that of example 1, and the vapor transmission rate change and oxygen transmission rate change are higher than those of example 1, wherein example 4 exhibits the best tensile properties, ultraviolet resistance and barrier properties, indicating that compared with loaded TiO2 spores microcapsules, modified loaded TiO2 spores microcapsules as additives are more obvious in improving the tensile properties, ultraviolet resistance and barrier properties of high-transparency polyester film, and ginkgoic acid modification has the best effect. The reason may be that the modified loaded TiO2 spores microcapsules further enhance the interfacial compatibility and light stability through chemical modification, optimize the dispersibility, thereby performing more excellent in tensile properties and ultraviolet resistance, and the chemical modification further optimizes the surface properties of the microcapsules, so that it can better fill the micropores inside the film, optimize the microstructure, and further improve the barrier properties. Compared with chlorogenic acid and gallic acid, the long alkyl chain in ginkgoic acid structure can enhance the compatibility of the microcapsules with the polyester matrix, optimize the dispersibility of the microcapsules, and form a dense protective layer on the surface of the microcapsules through surface modification, thereby improving the light stability of TiO2 and reducing the defects and pores on the surface of the microcapsules. Therefore, ginkgoic acid exhibits the best modification effect in the modified loaded TiO2 spores microcapsules.

[0039] As can be seen from Table 1, after the antibacterial test, the antibacterial rates of Examples 2-4 on Escherichia coli and Staphylococcus aureus are higher than 90%, which shows good antibacterial effect, indicating that the introduction of modified TiO2 spore powder microcapsules is also beneficial to improve the antibacterial performance of high-transparency polyester film; The reason is that the modifiers gallic acid, chlorogenic acid and ginkgo acid have certain antibacterial properties. Compared with chlorogenic acid and ginkgo acid, gallic acid molecules contain multiple phenolic hydroxyl groups, which can better interact with bacterial cell membranes, destroy the integrity of the cell membrane, and thus inhibit bacterial growth.

[0040] Test Example 2 The finished high-transparency polyester film prepared in Example 1, Example 4, and Comparative Example 3-4 above was respectively taken as a test sample film, and recorded as Example 1, Example 5, and Comparative Example 3-4 group respectively. The sample film of each group was detected for heat insulation effect and light transmittance, and the specific test method was carried out according to the following: Heat insulation effect: determination of infrared blocking rate According to the method provided in GB / T 2680-2021 Building Glass-Determination of Solar Radiation Shielding Efficiency, the spectral transmission and reflection of the sample film were determined by using LAMBDA 1050+ ultraviolet-visible-near infrared spectrophotometer (American PerkinElmer Company), the film surface emissivity was calculated, and the total solar infrared heat energy transmittance g was calculated. IR And the total solar infrared heat energy blocking rate R was calculated according to the following formula, expressed in percentage; R = 1-g IR In the formula, R is the total solar infrared heat energy blocking rate; g IR is the total solar infrared heat energy transmittance.

[0041] Light transmittance: determination of visible light transmittance Take 5 pieces of 3mm flat glass with a size of 60mm x 60mm and a visible light transmittance of 95% ± 1%, and place them in a temperature of 15-25℃ and a humidity of 40%-80% for at least 24 hours; then paste the sample film with the same size as the glass to make a test sample; then according to the method provided in GB / T 2680-2021 Building Glass-Determination of Solar Radiation Shielding Efficiency, the spectral transmission of 380nm-780nm is determined, the visible light transmittance is calculated, expressed in percentage; for products with specified nominal values, calculate the difference between each measured value and the nominal value; for products without specified nominal values, calculate the difference between each measured value and the average value; The specific detection results are shown in Table 2 below.

[0042] From Table 2, it can be seen that comparative example 1, example 4, and comparative examples 2-4 find that, compared with comparative example 4 without the barrier layer, the infrared barrier rate of example 1, example 4 and comparative example 3 increases significantly, and the heat insulation performance is better, while the infrared barrier rate of comparative example 2 decreases, and the heat insulation performance is poorer; the determination results of visible light transmittance show that the visible light transmittance of example 1, example 4, comparative examples 3-4 is all higher than 90%, which shows good light transmittance, and compared with comparative example 4, the visible light transmittance of example 4 increases, which shows that the setting of the barrier layer is conducive to improving the light transmittance of the film; compared with comparative example 4, the visible light transmittance of example 1 and comparative example 3 also increases, while the visible light transmittance of comparative example 2 decreases, and the light transmittance is poorer; compared with comparative example 3, the visible light transmittance of example 1 and example 4 slightly decreases, while the visible light transmittance of example 4 decreases less, and the light transmittance is almost not affected.

Claims

1. A high clarity, heat-shielded polyester film characterized by: The barrier layer is formed by coating a barrier liquid on the surface of the polyester base layer; the polyester base layer is a biaxially stretched polyester film; and the biaxially stretched polyester film is added with TiO2 spore powder microcapsules or modified TiO2 spore powder microcapsules.

2. The heat-shielded, high-transmission polyester film according to claim 1, characterized in that: The thickness of the heat-insulating high-transparency polyester film is 20-25 microns.

3. The heat-shielded, high-transmission polyester film according to claim 1, wherein: The preparation method of the barrier liquid comprises the following steps, by weight: 8-12 parts by weight of cycloolefin copolymer is added into 45-55 parts by weight of dimethylbenzene solution to mix until completely dissolved to obtain a cycloolefin copolymer solution; 0.1-0.6 parts by weight of lanthanum hexaboride nanoparticles is added into 45-55 parts by weight of dimethylbenzene solution to mix until completely dissolved to obtain a lanthanum hexaboride solution; then the lanthanum hexaboride solution is added into the cycloolefin copolymer solution to mix and stir for 20-40 minutes to form the barrier liquid.

4. The heat-shielded, high-transmission polyester film according to claim 1, wherein: The preparation method of the biaxially stretched polyester film comprises the following steps: The raw material components are weighed by weight parts: PET resin 60-80 parts, polyglycolic acid 10-20 parts, auxiliary agent 1-2 parts, stabilizer 1-3 parts, dispersing agent 1-5 parts; then the PET resin and the polyglycolic acid are dried to obtain dried PET resin and polyglycolic acid, the dried PET resin and polyglycolic acid are mixed, then the auxiliary agent, the stabilizer and the dispersing agent are added and uniformly mixed, and then sent into a double screw extruder to melt and extrude to form a melt film, and then the melt film is cast on a cooling roller through a casting die to cool, to form a cast sheet, and then transversely stretched and longitudinally stretched, heat set, and cooled to obtain the biaxially stretched polyester film. The auxiliary agent is selected from one of the loaded TiO2 spore powder microcapsules and the modified loaded TiO2 spore powder microcapsules.

5. The heat-shielded, high-transmission polyester film according to claim 4, characterized in that: The preparation method of the loaded TiO2 spore powder microcapsules comprises the following steps, by weight parts: 9-11 parts by weight of spore powder microcapsules are dispersed in 480-520 parts by weight of anhydrous ethanol, ultrasonic treatment is performed for 20-30 minutes, centrifugation is performed at 6000-10000 rpm for 5-12 minutes, the precipitate is collected and dried to obtain pretreated spore powder microcapsules; 5.7-5.9 parts by weight of the pretreated spore powder microcapsules are added into 48-52 parts by weight of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:4-6, stirring is performed for 20-35 minutes, 4-6 parts by weight of nitric acid aqueous solution is added dropwise at a constant temperature of 58-62°C, and then the reaction is continued at 58-62°C for 5-8 hours; the reaction solution is centrifuged at 8000 rpm for 10 minutes, the precipitate is collected, washed with ethanol and water for 4-5 times, and vacuum dried at 58-62°C to obtain the loaded TiO2 spore powder microcapsules.

6. The heat-shielded, high-transmission polyester film according to claim 4, wherein The preparation method of the modified loaded TiO2 spore powder microcapsules comprises the following steps, by weight parts: Preparation of the modified loaded TiO2sporopollenin microcapsule: 9-11 parts of sporopollenin microcapsule were dispersed in 480-520 parts of anhydrous ethanol, and ultrasonic treatment was performed for 20-30 min. Centrifugation was performed at 6000-10000 rpm for 5-12 min. The precipitate was collected and dried to obtain pretreated sporopollenin microcapsule. 5.7-5.9 parts of the pretreated sporopollenin microcapsule were added to 48-52 parts of a mixed solution prepared by mixing tetrabutyl titanate and anhydrous ethanol at a weight ratio of 1:4-6, and stirring was performed for 20-35 min. 4-6 parts of nitric acid aqueous solution were added dropwise at a constant temperature of 58-62℃, and then the reaction was continued at 58-62℃ for 5-8 h. The reaction solution was centrifuged at 8000 rpm for 10 min. The precipitate was collected and washed with ethanol and water for 4-5 times, respectively, and dried at 58-62℃ under vacuum to obtain the loaded TiO2sporopollenin microcapsule. 0.9-1.1 parts of the loaded TiO2sporopollenin microcapsule were dispersed in 48-52 parts of anhydrous N,N-dimethylformamide, and ultrasonic treatment was performed for 20-35 min. Then, 0.4-0.6 parts of a modifier, 0.03-0.1 parts of N,N'-dicyclohexyl carbodiimide, and 0.01-0.06 parts of 4-dimethylamino pyridine were added. Mixing reaction was performed at 58-62℃ under nitrogen protection for 10-13 h. The reaction solution was centrifuged at 6000-9000 rpm for 8-12 min. The precipitate was collected and washed with anhydrous N,N-dimethylformamide, ethanol, and water for 2-3 times, respectively, and dried at 58-62℃ under vacuum to obtain the modified loaded TiO2sporopollenin microcapsule.

7. The heat shielded, high transmission polyester film of claim 6 wherein: The modifier is selected from one of gallic acid, chlorogenic acid, and ginkgo acid.

8. The heat shielded, high transmission polyester film of claim 4 wherein: The stabilizer is selected from at least one of calcium stearate, triphenyl phosphate, and trimethyl phosphate; and the dispersant is selected from at least one of polyethylene wax, paraffin wax, and ethylene bis-oleic acid amide.

9. A process for the production of the heat shielded, high- transparent polyester film according to any one of claims 1 to 8, characterized in that The method comprises the following steps: The barrier liquid is applied to the polyester base layer after corona treatment by using the blade coating method, so as to form a barrier layer on the polyester base layer; then it is introduced into the oven for drying at 90-110℃ for 10-14h, and then treated at high temperature of 150-200℃ for 0.5-2h, and then put into the laminating machine for molding at 150-160℃ for 8-13min, so as to form the heat-insulating high-transparency polyester film composed of the barrier layer and the polyester base layer; wherein the coating amount of the barrier liquid is 1-1.4g / m 2 .

10. Use of the heat shielded, high transmission polyester film according to any one of claims 1 to 8, characterized in that The heat-insulating high-transparency polyester film can be used for preparing product packaging of daily chemical products, medicines, and food. The heat-insulating high-transparency polyester film can be used for preparing product packaging of daily chemical products, medicines, and food.

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