A high-adsorption cooling film for grape cultivation and preparation method thereof

Abstract

The present invention relates to the technical field of agricultural films, and more particularly to a high-adsorption cooling film for grape cultivation and a preparation method thereof. The high-adsorption cooling film is composed of an anti-ultraviolet oxidation layer, a cooling layer, and an adsorption base layer, which are composited from the outside inward. The anti-ultraviolet oxidation layer is composed of an anti-ultraviolet agent, an antioxidant, and polyethylene particles; the cooling layer is made of polyethylene grafted with a spiropyran compound; and the adsorption base layer is composed of mesoporous silica and polyethylene particles. The film prepared by the present invention utilizes the unique reversible reaction of spiropyran compounds, which is heat absorption during ring opening and heat release during ring closing. The film is combined with the phenomenon that the spiropyran compounds darken in color when absorbing heat during ring opening, which can reflect and block sunlight, thereby achieving a cooling effect. At the same time, the preparation method is conventional, the raw materials are easily obtained, the service life is long, and it has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural films, in particular to a high-adsorption cooling film for grape cultivation and a preparation method thereof. Background Art

[0002] Agricultural film plays a crucial role in grape cultivation. It not only maintains soil moisture and inhibits weed growth, but also regulates temperature and light conditions within the microenvironment to promote healthy grape growth. While widely used in grape cultivation, traditional polyethylene film has some drawbacks. For example, during the hot summer months, the temperature inside the film can be excessively high, affecting grape photosynthesis and respiration, and thus grape yield and quality. Furthermore, traditional film has limited ability to absorb harmful gases (such as ethylene and sulfur dioxide) and excess water from the environment, making it ineffective in improving the microenvironment within the film and thus detrimental to grape growth and development.

[0003] In recent years, researchers have tried to improve the comprehensive performance of films by adding functional additives such as anti-ultraviolet agents, antioxidants, and adsorbents. However, these additives have deficiencies in dispersibility and compatibility, which limits further improvement in film performance. At the same time, some new cooling materials such as various phase change cooling materials have also been tried in polyethylene films, but conventional phase change materials have a single cooling method and a short repeated service life. These problems limit the large-scale application of cooling films. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose a high-adsorption cooling film for grape cultivation and a preparation method thereof, so as to solve the problems of existing agricultural films such as poor cooling effect, short service life, and inability to have both good cooling performance and adsorption performance.

[0005] Based on the above purpose, the present invention provides a high-absorption cooling film for grape cultivation, which is composed of an anti-ultraviolet oxidation layer, a cooling layer and an adsorption base layer in order from the outside to the inside;

[0006] The anti-ultraviolet oxidation layer is composed of an anti-ultraviolet agent, an antioxidant and polyethylene particles;

[0007] The cooling layer is made of polyethylene grafted with a spiropyran compound, and the preparation method of the spiropyran compound is as follows:

[0008] (1) Add 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 5-nitrosalicylic acid aldehyde to ethanol, stir, and reflux for 8-10 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product. The reaction equation is as follows: Formula (1);

[0009] (2) The crude product obtained in (1) was eluted with a petroleum ether / ethyl acetate system by silica gel column chromatography, and the excess elution solvent was removed by distillation under reduced pressure. After drying, a spiropyran compound was obtained. The product was characterized by H NMR and FTIR infrared spectroscopy. HNMR (400 MHz, Chloroform-d) δ8.19 (d, J = 2.3 Hz, 1H), 8.05 (dd, J = 7.8, 2.3 Hz, 1H), 7.14 (dd, J = 7.5, 2.2 Hz, 1H), 7.09 (d, J = 2.2 Hz, 1H), 7.01 (d, J =7.9 Hz, 1H), 6.78-6.67 (m, 2H), 5.92 (d, J = 8.4 Hz, 1H), 2.86 (s, 3H), 1.42 (s, 3H), 1.37 (s, 3H);

[0010] The adsorption base layer is composed of mesoporous silicon dioxide and polyethylene particles.

[0011] Preferably, the anti-ultraviolet agent is 2-hydroxy-4-n-octyloxybenzophenone or 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol.

[0012] Preferably, the antioxidant refers to antioxidant 1010 or antioxidant 168.

[0013] Preferably, the weight ratio of 5-chloro-1,3,3-trimethyl-2-methyleneindoline, 5-nitrosalicylic acid aldehyde and ethanol in (1) is 1:1:10-15.

[0014] Preferably, the (2) petroleum ether / ethyl acetate system elution refers to a gradient elution method, wherein the volume ratio of petroleum ether to ethyl acetate in each step of the eluent is successively 1:0, 10:1, 5:1 and 1:1.

[0015] Preferably, the temperature regulation mechanism of the spiropyran compound is:

[0016] Formula (2)

[0017] When the temperature of the spiropyran compound reaches the phase transition temperature, a ring-opening reaction occurs to absorb heat, and its own color changes from transparent to dark, which can effectively block sunlight and reduce the temperature. When the temperature drops, the spiropyran compound undergoes a ring-closing reaction, releasing heat, and its own color returns to transparency, which has a certain thermal insulation effect. These two reactions are reversible reactions, providing the spiropyran compound with the ability to regulate temperature.

[0018] Preferably, the particle size of the mesoporous silica is 200 nm.

[0019] Furthermore, the present invention also provides a method for preparing the high-adsorption cooling film for grape cultivation, which specifically comprises the following steps:

[0020] S1: Preparation of UV-resistant oxidation layer: Anti-UV agent, antioxidant and polyethylene particles are mixed, heated and co-extruded through a twin-screw extruder, and blown into a film through a blow molding machine to obtain an UV-resistant oxidation layer with a thickness of 15-25 μm. The parameters of the twin-screw extruder are as follows: zone 1 temperature of 140-150°C, zone 2 temperature of 160-170°C, zone 3 temperature of 155-165°C, head temperature of 160°C, screw speed of 60-80 rpm, and blow molding machine parameters of a blow ratio of 2.5-3.5:1 and a draw ratio of 4-6:1;

[0021] S2: Preparation of cooling layer: under nitrogen protection, polyethylene powder, ferrous chloride and benzoyl peroxide are added to ethanol, heated to 60-70°C, reacted for 30-60 minutes, and then a spiropyran compound is added, heated to 80-90°C, reacted for 8-10 hours, cooled to room temperature, and excess ethanol is removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene is obtained. The spiropyran-grafted polyethylene is heated and extruded through a twin-screw extruder and blown into a film through a blow molding machine to obtain a cooling layer with a thickness of 40-60 μm. The parameters of the twin-screw extruder are as follows: a zone 1 temperature of 140-150°C, a zone 2 temperature of 150-160°C, a zone 3 temperature of 155-165°C, a die head temperature of 155°C, a screw speed of 60-80 rpm, and parameters of the blow molding machine are a blow ratio of 2.5-3.5:1 and a traction ratio of 4-6:1;

[0022] S3: Preparation of adsorption base layer: Mesoporous silica and polyethylene particles are mixed, heated and co-extruded through a twin-screw extruder, and blown into a film using a blow molding machine to obtain an adsorption base layer with a thickness of 30-40 μm. The parameters of the twin-screw extruder are as follows: zone 1 temperature of 140-150°C, zone 2 temperature of 160-170°C, zone 3 temperature of 150-160°C, die head temperature of 155°C, screw speed of 60-80 rpm, and blow molding machine parameters of a blow ratio of 2.5-3.5:1 and a draw ratio of 4-6:1;

[0023] S4: stacking the anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer in sequence from the outside to the inside, and forming the composite film by setting the temperature to 80-100°C, the pressure to 5-7MPa, and the holding time to 3-5min on a hot press. After cooling, a high-adsorption cooling film for grape cultivation is obtained.

[0024] Preferably, the weight ratio of the anti-ultraviolet agent, antioxidant and polyethylene particles in S1 is 0.03-0.05:0.01-0.02:1.

[0025] Preferably, the weight ratio of the spiropyran compound, polyethylene powder, ferrous chloride, benzoyl peroxide and ethanol in S2 is 0.1-0.2:1:0.005-0.01:0.015-0.03:10-14, and the reaction equation is as follows: Formula (3), The product was characterized by FTIR infrared spectroscopy.

[0026] Preferably, the weight ratio of the mesoporous silica and polyethylene particles in S3 is 0.1-0.16:1.

[0027] Beneficial effects of the present invention:

[0028] 1. The present invention introduces a spiropyran compound into the film and utilizes its unique ring-opening heat absorption characteristics to achieve cooling. The present invention actively shields external ultraviolet light through the structural design of the film, so that the spiropyran compound changes from a dual ultraviolet light-temperature response to a ring-opening reaction that only occurs when the phase transition temperature is reached. The change in molecular structure enables it to absorb a large amount of heat energy, thereby effectively reducing the surface temperature of the film. At the same time, the color of the spiropyran compound after ring opening becomes darker, which can block sunlight from passing through the film and reduce the heating effect of solar radiation on the grape plants. Finally, under the condition of low temperatures in winter, even if there is light, the spiropyran compound in the film prepared by the present invention will not undergo a ring-opening reaction to deepen its own color, thereby maintaining good light transmittance, ensuring a certain thermal insulation effect, and providing suitable conditions for grape growth.

[0029] 2. The film of this invention utilizes a three-layer composite structure, with the materials of each layer complementing each other to enhance overall mechanical properties. The antioxidant and UV inhibitor in the UV-resistant oxidation layer enhance the polyethylene's aging resistance. The spiropyran compound grafted onto the polyethylene in the cooling layer forms a compact structure through chemical bonding, enhancing tensile strength. The mesoporous silica in the adsorption base layer, mixed with polyethylene particles, increases material rigidity, ensuring the film can withstand the mechanical stresses of the external environment during grape cultivation, reducing the risk of breakage and tearing.

[0030] 3. Although the spiropyran compound used in the present invention has good color-changing properties, it is prone to molecular structure degradation under long-term ultraviolet irradiation, resulting in performance degradation and limited service life. The present invention effectively blocks the direct effect of ultraviolet rays on the spiropyran compound by adding an anti-ultraviolet oxidation layer, reducing the occurrence of photo-oxidative degradation. The anti-ultraviolet agent in the anti-ultraviolet oxidation layer can absorb and quench ultraviolet rays, while the antioxidant can capture and eliminate free radicals generated during the photo-oxidation process, further inhibiting aging reactions. The synergistic effect of these two significantly improves the stability and durability of the spiropyran compound and extends its service life in the film. In addition, by modifying the molecular structure of the spiropyran compound and introducing a nitro group, the nitro group acts as a strong electron-withdrawing group, which greatly reduces the phase transition temperature of the spiropyran compound. In actual use, a ring-opening reaction can occur at the right temperature, no longer relying on ultraviolet light to generate the ring-opening reaction, and reducing the impact of the anti-ultraviolet oxidation layer blocking ultraviolet light. This ensures that the film can continue to exert a cooling effect during the grape cultivation process, reducing the economic losses and replacement costs caused by the decline in film performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the H NMR spectrum of the spiropyran compound;

[0032] Figure 2 This is the FTIR infrared spectrum of the spiropyran compound. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0034] The sources of the reagents and raw materials used in the examples of the present invention are as follows:

[0035] 5-Chloro-1,3,3-trimethyl-2-methyleneindoline was purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd., product number 1039958, purity 95%; 5-Nitrosalicylic acid aldehyde was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., product number N814745, purity 98%; 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., product number H834139, purity 98%; Antioxidant 1010 was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., product number P750268, purity 98%; Mesoporous silica was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Polyethylene granules were purchased from Shanghai Dingfen Chemical Technology Co., Ltd., with the item number M758933 and a particle size of 200 nm; polyethylene particles were purchased from Shanghai Dingfen Chemical Technology Co., Ltd., with the item number P06526; polyethylene powder was purchased from Wuxi Baimao Plastic Co., Ltd., with a particle size of 200-500 mesh; salicylic acid aldehyde was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., with the item number S817504 and a purity of 98%; paraffin was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., with the item number P815421; silicon dioxide was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with the item number S25691 and a particle size of 100 mesh; polyethylene film was purchased from Kingfa Science and Technology Co., Ltd., with thicknesses of 20 μm, 50 μm, and 35 μm.

[0036] Example 1: A specific preparation method of a high-adsorption cooling film for grape cultivation, comprising the following steps:

[0037] (1) Add 1 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1 kg of 5-nitrosalicylic acid aldehyde to 10 kg of ethanol, stir, and reflux for 8 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0038] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0039] (3) Preparation of anti-ultraviolet oxidation layer: 300g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 100g of antioxidant 1010 and 10kg of polyethylene granules were mixed, heated and co-extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 15μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 140℃, the temperature of zone 2 was 160℃, the temperature of zone 3 was 155℃, the head temperature was 160℃, the screw speed was 60rpm, and the parameters of the blow molding machine were a blow ratio of 2.5:1 and a traction ratio of 4:1.

[0040] (4) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 50 g ferrous chloride and 150 g benzoyl peroxide were added to 100 kg ethanol and heated to 60 ° C., reacted for 30 min, and then 1 kg spiropyran compound obtained in (2) was added, heated to 80 ° C., reacted for 8 h, cooled to room temperature, and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene was obtained. The spiropyran-grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 40 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 140 ° C., the temperature of zone 2 was 150 ° C., the temperature of zone 3 was 155 ° C., the head temperature was 155 ° C., the screw speed was 60 rpm, and the parameters of the blow molding machine were a blow ratio of 2.5:1 and a traction ratio of 4:1.

[0041] (5) Preparation of adsorption base layer: 1 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 30 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 140 °C, zone 2 temperature of 160 °C, zone 3 temperature of 150 °C, die head temperature of 155 °C, screw speed of 60 rpm, and blow molding machine parameters of a blow ratio of 2.5:1 and a traction ratio of 4:1;

[0042] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and are hot-pressed and composited by setting the temperature to 80°C, the pressure to 5 MPa, and the holding time to 3 min. After cooling, a high-adsorption cooling film for grape cultivation is obtained.

[0043] Example 2: A specific preparation method of a high-adsorption cooling film for grape cultivation, comprising the following steps:

[0044] (1) Add 1.5 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1.5 kg of 5-nitrosalicylic acid aldehyde to 18 kg of ethanol, stir, and reflux for 9 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0045] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0046] (3) Preparation of anti-ultraviolet oxidation layer: 400 g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 150 g of antioxidant 1010 and 10 kg of polyethylene particles were mixed, heated and co-extruded through a twin-screw extruder and blown into a film through a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 20 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 165 °C, the temperature of zone 3 was 160 °C, the head temperature was 160 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0047] (4) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 75 g ferrous chloride and 225 g benzoyl peroxide were added to 120 kg ethanol and heated to 65 ° C., reacted for 45 min, and then 1.5 kg spiropyran compound obtained in (2) was added, heated to 85 ° C., reacted for 9 h, cooled to room temperature, and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene was obtained. The spiropyran-grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 ° C., the temperature of zone 2 was 155 ° C., the temperature of zone 3 was 160 ° C., the head temperature was 155 ° C., the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0048] (5) Preparation of adsorption base layer: 1.3 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1;

[0049] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and the hot pressing is performed by setting the temperature at 90°C, the pressure at 6 MPa, and the holding time at 4 min. After cooling, a high adsorption cooling film for grape cultivation is obtained.

[0050] Example 3: A specific preparation method of a high-adsorption cooling film for grape cultivation, comprising the following steps:

[0051] (1) Add 2 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 2 kg of 5-nitrosalicylic acid aldehyde to 30 kg of ethanol, stir, and reflux for 10 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0052] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0053] (3) Preparation of anti-ultraviolet oxidation layer: 500g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 200g of antioxidant 1010 and 10kg of polyethylene granules were mixed, heated and co-extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 25μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 150℃, the temperature of zone 2 was 170℃, the temperature of zone 3 was 165℃, the head temperature was 160℃, the screw speed was 80rpm, and the parameters of the blow molding machine were a blow ratio of 3.5:1 and a traction ratio of 6:1.

[0054] (4) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 100 g ferrous chloride and 300 g benzoyl peroxide were added to ethanol and heated to 70 ° C. and reacted for 60 min. Then 2 kg spiropyran compound obtained in (2) was added and heated to 90 ° C. and reacted for 10 h. The mixture was cooled to room temperature and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran grafted polyethylene was obtained. The spiropyran grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 60 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 150 ° C., the temperature of zone 2 was 160 ° C., the temperature of zone 3 was 165 ° C., the head temperature was 155 ° C., the screw speed was 80 rpm. The parameters of the blow molding machine were a blow ratio of 3.5:1 and a traction ratio of 6:1.

[0055] (5) Preparation of adsorption base layer: 1.6 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 40 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 150 °C, zone 2 temperature of 170 °C, zone 3 temperature of 160 °C, die head temperature of 155 °C, screw speed of 80 rpm, and blow molding machine parameters of 3.5:1 blow ratio and 6:1 pull ratio;

[0056] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and are hot-pressed and composited by setting the temperature to 100°C, the pressure to 7 MPa, and the holding time to 5 min. After cooling, a high-adsorption cooling film for grape cultivation is obtained.

[0057] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the spiropyran compound does not contain a nitro group. The specific preparation process is as follows:

[0058] (1) Add 1.5 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1.5 kg of salicylic acid aldehyde to 18 kg of ethanol, stir, and reflux for 9 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0059] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0060] (3) Preparation of anti-ultraviolet oxidation layer: 400 g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 150 g of antioxidant 1010 and 10 kg of polyethylene particles were mixed, heated and co-extruded through a twin-screw extruder and blown into a film through a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 20 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 165 °C, the temperature of zone 3 was 160 °C, the head temperature was 160 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0061] (4) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 75 g ferrous chloride and 225 g benzoyl peroxide were added to 120 kg ethanol and heated to 65 ° C., reacted for 45 min, and then 1.5 kg spiropyran compound obtained in (2) was added, heated to 85 ° C., reacted for 9 h, cooled to room temperature, and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene was obtained. The spiropyran-grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 ° C., the temperature of zone 2 was 155 ° C., the temperature of zone 3 was 160 ° C., the head temperature was 155 ° C., the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0062] (5) Preparation of adsorption base layer: 1.3 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1;

[0063] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and the hot pressing is performed by setting the temperature at 90°C, the pressure at 6 MPa, and the holding time at 4 min. After cooling, a high adsorption cooling film for grape cultivation is obtained.

[0064] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the spiropyran compound and polyethylene are physically blended. The specific preparation process is as follows:

[0065] (1) Add 1.5 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1.5 kg of 5-nitrosalicylic acid aldehyde to 18 kg of ethanol, stir, and reflux for 9 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0066] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0067] (3) Preparation of anti-ultraviolet oxidation layer: 400 g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 150 g of antioxidant 1010 and 10 kg of polyethylene particles were mixed, heated and co-extruded through a twin-screw extruder and blown into a film through a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 20 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 165 °C, the temperature of zone 3 was 160 °C, the head temperature was 160 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0068] (4) Preparation of cooling layer: 10 kg of polyethylene powder and 1.5 kg of spiropyran compound obtained in (2) were mixed, heated and extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145°C, zone 2 temperature of 155°C, zone 3 temperature of 160°C, die head temperature of 155°C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1.

[0069] (5) Preparation of adsorption base layer: 1.3 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1;

[0070] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and the hot pressing is performed by setting the temperature at 90°C, the pressure at 6 MPa, and the holding time at 4 min. After cooling, a high adsorption cooling film for grape cultivation is obtained.

[0071] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the high-absorption cooling film for grape cultivation does not contain an anti-ultraviolet oxidation adsorption layer. The specific preparation process is as follows:

[0072] (1) Add 1.5 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1.5 kg of 5-nitrosalicylic acid aldehyde to 18 kg of ethanol, stir, and reflux for 9 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0073] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0074] (3) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 75 g ferrous chloride and 225 g benzoyl peroxide were added to 120 kg ethanol and heated to 65 ° C., reacted for 45 min, and then 1.5 kg spiropyran compound obtained in (2) was added, heated to 85 ° C., reacted for 9 h, cooled to room temperature, and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene was obtained. The spiropyran-grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 ° C., the temperature of zone 2 was 155 ° C., the temperature of zone 3 was 160 ° C., the head temperature was 155 ° C., the screw speed was 70 rpm. The parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0075] (4) Preparation of adsorption base layer: 1.3 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1;

[0076] (6) The cooling layer and the adsorption base layer are stacked from the outside to the inside, and the temperature is set at 90 ° C, the pressure is 6 MPa, and the holding time is 4 min. The hot pressing composite molding is performed, and after cooling, a high adsorption cooling film for grape planting is obtained.

[0077] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the cooling layer is made of paraffin and polyethylene. The specific preparation process is as follows:

[0078] (1) Preparation of anti-ultraviolet oxidation layer: 400 g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 150 g of antioxidant 1010 and 10 kg of polyethylene granules were mixed, heated and co-extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 20 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 165 °C, the temperature of zone 3 was 160 °C, the head temperature was 160 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0079] (2) Preparation of cooling layer: 10 kg of polyethylene powder and 1.5 kg of paraffin wax were mixed, heated and extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 155 °C, the temperature of zone 3 was 160 °C, the head temperature was 155 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0080] (5) Preparation of adsorption base layer: 1.3 kg of mesoporous silica and 10 kg of polyethylene particles were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1;

[0081] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and the hot pressing is performed by setting the temperature at 90°C, the pressure at 6 MPa, and the holding time at 4 min. After cooling, a high adsorption cooling film for grape cultivation is obtained.

[0082] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that the adsorption substrate is made of silicon dioxide and polyethylene. The specific preparation process is as follows:

[0083] (1) Add 1.5 kg of 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 1.5 kg of 5-nitrosalicylic acid aldehyde to 18 kg of ethanol, stir, and reflux for 9 hours. After cooling to room temperature, remove excess ethanol by vacuum distillation to obtain a crude product.

[0084] (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying;

[0085] (3) Preparation of anti-ultraviolet oxidation layer: 400 g of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 150 g of antioxidant 1010 and 10 kg of polyethylene particles were mixed, heated and co-extruded through a twin-screw extruder and blown into a film through a blow molding machine to obtain an anti-ultraviolet oxidation layer with a thickness of 20 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 °C, the temperature of zone 2 was 165 °C, the temperature of zone 3 was 160 °C, the head temperature was 160 °C, the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0086] (4) Preparation of cooling layer: under nitrogen protection, 10 kg polyethylene powder, 75 g ferrous chloride and 225 g benzoyl peroxide were added to 120 kg ethanol and heated to 65 ° C., reacted for 45 min, and then 1.5 kg spiropyran compound obtained in (2) was added, heated to 85 ° C., reacted for 9 h, cooled to room temperature, and the excess ethanol was removed by vacuum distillation. After washing and drying, spiropyran-grafted polyethylene was obtained. The spiropyran-grafted polyethylene was heated and extruded by a twin-screw extruder and blown into a film by a blow molding machine to obtain a cooling layer with a thickness of 50 μm. The parameters of the twin-screw extruder were as follows: the temperature of zone 1 was 145 ° C., the temperature of zone 2 was 155 ° C., the temperature of zone 3 was 160 ° C., the head temperature was 155 ° C., the screw speed was 70 rpm, and the parameters of the blow molding machine were a blow ratio of 3:1 and a traction ratio of 5:1.

[0087] (5) Preparation of adsorption base layer: 1.3 kg of silica and 10 kg of polyethylene granules were mixed, heated and co-extruded by a twin-screw extruder, and blown into a film by a blow molding machine to obtain an adsorption base layer with a thickness of 35 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 145 °C, zone 2 temperature of 165 °C, zone 3 temperature of 155 °C, die head temperature of 155 °C, screw speed of 70 rpm, and blow molding machine parameters of a blow ratio of 3:1 and a traction ratio of 5:1.

[0088] (6) The anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer are stacked in sequence from the outside to the inside, and the hot pressing is performed by setting the temperature at 90°C, the pressure at 6 MPa, and the holding time at 4 min. After cooling, a high adsorption cooling film for grape cultivation is obtained.

[0089] Comparative Example 6: The difference between Comparative Example 6 and Example 2 is that the high-adsorption cooling film for grape cultivation is made by hot-pressing three layers of polyethylene films with thicknesses of 20 μm, 50 μm, and 35 μm, respectively. The specific process is as follows:

[0090] Three layers of polyethylene films with thicknesses of 20 μm, 50 μm and 35 μm were stacked from outside to inside, and hot-pressed and composited using a hot press with a temperature of 90°C, a pressure of 6 MPa and a holding time of 4 minutes. After cooling, a high-adsorption cooling film for grape cultivation was obtained.

[0091] Performance testing:

[0092] 1. Mechanical property test: Using a universal material testing machine, the films prepared in Examples 1-3 and Comparative Example 6 were subjected to tensile tests and elongation at break tests. The experimental results are shown in Table 1.

[0093] 2. Anti-aging performance test: Use a xenon lamp aging test chamber, irradiance: 0.55 W / m² (at 340 nm);

[0094] Blackboard temperature: 60±2°C; humidity: 50±5% RH; cycle: 102 minutes of illumination + 18 minutes of water spraying; time: 1000 h. The films prepared in Examples 1-3 and Comparative Example 3 were subjected to anti-aging tests, and the performance retention rate of each experimental group after the aging time was calculated: for example, tensile strength retention rate = (initial strength - strength after aging) / initial strength × 100%; transmittance retention rate = (initial transmittance - transmittance after aging) / initial transmittance × 100%. The experimental results are shown in Table 2.

[0095] 3. Cooling Performance Test: Outdoor environments at 35°C with and without illumination, and at 25°C with and without illumination were simulated. The simulated illumination is cold light and does not increase the ambient temperature. The cooling temperatures and the times required to reach the lowest temperature for the films prepared in Examples 1-3 and Comparative Examples 1-4 were tested. The experimental results are shown in Table 3.

[0096] 4. Adsorption performance test: The films prepared in Examples 1-3 and Comparative Example 5 were subjected to an adsorption performance test. The test samples were placed in an environmental simulation box, and the environment in the box was kept consistent. The moisture concentration, ethylene concentration, and SO2 concentration before the test were recorded. The moisture concentration, ethylene concentration, and SO2 concentration in the box were recorded after the test. The adsorption rate of the film was calculated, and the adsorption equilibrium time was recorded. The adsorption rate = (initial concentration - residual concentration) / initial concentration × 100%. The experimental results are shown in Table 4.

[0097] 5. Light transmittance test: The films prepared in Examples 1-3 and Comparative Example 3 were placed in an environment with direct sunlight for 2 hours, simulating a sunny outdoor day at temperatures of 25°C, 30°C, and 35°C, respectively. The direct sunlight is cold light and does not increase the ambient temperature. The light transmittance of the films was tested using a spectrophotometer. The experimental data are shown in Table 5.

[0098] Table 1 Mechanical properties

[0099] Table 2 Anti-aging performance

[0100] Table 3 Cooling performance

[0101] Table 4 Adsorption performance

[0102] Table 5 Transmittance

[0103] Data Analysis:

[0104] As can be seen from the data in Tables 1-5, the high-adsorption cooling films for grape cultivation prepared using the present invention in Examples 1-3 not only have good mechanical properties and anti-aging properties, but also have a good cooling effect that is not affected by light. Furthermore, the films also have a certain adsorption effect on some harmful substances that may be present during the grape growth process. Among them, Example 2 has the best overall performance.

[0105] It can be seen from the data in Table 1 that compared with the film formed by hot-pressing and compounding three layers of ordinary polyethylene used in Comparative Example 6, Example 2 has no decline in mechanical properties and is even slightly better than Comparative Example 6. This may be because the film prepared in Example 2 includes an anti-ultraviolet oxidation layer, a cooling layer and an adsorption base layer. The materials of each layer cooperate with each other to improve the overall mechanical properties. The antioxidant and anti-ultraviolet agent in the anti-ultraviolet oxidation layer not only provide protective performance, but also enhance the toughness of polyethylene. The spiropyran compound grafted polyethylene in the cooling layer is chemically bonded to form a tighter structure, which improves the tensile strength. The mixture of mesoporous silica and polyethylene particles in the adsorption base layer increases the rigidity of the material, which helps to improve the elongation at break.

[0106] As can be seen from the data in Table 2, Example 2 is significantly improved in anti-aging performance compared to Comparative Example 3. This may be because the film prepared in Example 2 has an anti-ultraviolet oxidation layer, in which the anti-ultraviolet agent can effectively absorb and quench ultraviolet rays, reducing the direct effect of ultraviolet rays on the polyethylene molecular chain, thereby reducing the occurrence of photooxidative degradation, and the antioxidant can capture and eliminate the free radicals generated by polyethylene during the photooxidation process, further inhibiting the progress of the aging reaction. The synergistic effect of the two enables the film to maintain a high tensile strength and transmittance under long-term illumination and high temperature conditions, while also protecting the spiropyran compound from irreversible ring-opening and ring-closing reactions when facing ultraviolet irradiation for a long time. The spiropyran compound cannot be ring-closed, and its own color cannot be changed from dark to light, resulting in a decrease in transmittance.

[0107] It can be seen from the data in Table 3 that the film prepared in Example 2 has good cooling performance and the cooling effect is not affected by light. This may be because the spiropyran compound used in Example 2 contains nitro, which, as a strong electron-withdrawing group, greatly reduces the phase transition enthalpy of the spiropyran compound, so that even if the spiropyran compound is shielded from ultraviolet light, it can quickly open the ring and absorb heat when it reaches the phase transition temperature, thereby avoiding the influence of environmental factors on the cooling performance; by adopting the grafting method, the spiropyran compound is evenly distributed in the polyethylene film, avoiding the agglomeration caused by physical blending, and increasing the spiropyran compound. The contact area between the compound and the outside world is larger, making it easier to respond to temperature changes, thereby increasing the cooling temperature and reducing the time required for cooling. Finally, the cooling performance of spiropyran compounds is better than that of traditional paraffin wax. This is because spiropyran compounds not only rely on their own phase change to absorb heat, but also can darken their color through ring-opening reactions, further reflecting and blocking sunlight, and synergistically achieving a cooling effect. Paraffin wax only relies on its own phase change to achieve a cooling effect, and its cooling performance is limited. At the same time, the higher phase change temperature of paraffin wax restricts its use environment, and it is not suitable for use in the field of agricultural films.

[0108] The data in Table 4 show that the film performance of Example 2 is superior to that of Comparative Example 5. This is likely because the mesoporous silica used in Example 2 has a higher specific surface area and a large number of active adsorption sites on its surface, which can form strong van der Waals forces or chemical bonds with adsorbed molecules, thereby improving the adsorption capacity for substances such as water, ethylene, and sulfur dioxide. The adsorption base layer in Comparative Example 5 uses ordinary silica, which has a relatively low specific surface area and a wide and uneven pore size distribution. This results in a limited number of adsorption sites and a weaker adsorption capacity for the target substance. In addition, the pore size of ordinary silica may be larger or smaller, which limits its adsorption effect for gas molecules and organic molecules of a specific size.

[0109] It can be seen from the data in Table 5 that the transmittance of the film prepared in Example 2 is only affected by temperature. This may be because the anti-ultraviolet oxide layer shields ultraviolet light, so that the spiropyran compound only relies on the temperature to reach the phase transition temperature to open the ring and deepen its own color, and no longer responds to light. This is beneficial for this film in the summer, when exposed to high-temperature sunlight, to absorb heat through phase change and darkening of its own color, block sunlight, and achieve a cooling effect; in winter, in an environment with sunlight but the temperature does not reach the phase transition temperature, the film maintains good light transmittance, and has a certain thermal insulation effect when used in winter environments, which broadens the scope of use of this film, avoids frequent replacement, and reduces the cost of use.

[0110] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A high-adsorption cooling film for grape cultivation, characterized in that: From the outside to the inside, it is composed of an anti-ultraviolet oxidation layer, a cooling layer and an adsorption base layer; The anti-ultraviolet oxidation layer is composed of an anti-ultraviolet agent, an antioxidant and polyethylene particles; the anti-ultraviolet agent is 2-hydroxy-4-n-octyloxybenzophenone or 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol; The cooling layer is made of polyethylene grafted with a spiropyran compound. The specific preparation process of the polyethylene grafted with a spiropyran compound is as follows: Under nitrogen protection, polyethylene powder, ferrous chloride and benzoyl peroxide are added to ethanol, heated to 60-70°C, reacted for 30-60 minutes, and then a spiropyran compound is added, heated to 80-90°C, reacted for 8-10 hours, cooled to room temperature, and excess ethanol is removed by vacuum distillation. The product is washed and dried to obtain spiropyran-grafted polyethylene. In the specific preparation method of the spiropyran compound-grafted polyethylene, the weight ratio of the spiropyran compound, polyethylene powder, ferrous chloride, benzoyl peroxide and ethanol is 0.1-0.2:1:0.005-0.01:0.015-0.03:10-14; The preparation method of the spiropyran compound is as follows: (1) adding 5-chloro-1,3,3-trimethyl-2-methyleneindoline and 5-nitrosalicylic acid aldehyde to ethanol, stirring, and reflux reaction for 8-10 hours, cooling to room temperature, and removing excess ethanol by vacuum distillation to obtain a crude product; wherein the weight ratio of 5-chloro-1,3,3-trimethyl-2-methyleneindoline, 5-nitrosalicylic acid aldehyde and ethanol in (1) is 1:1:10-15; (2) The crude product obtained in (1) was eluted by silica gel column chromatography using a petroleum ether / ethyl acetate system, and the excess elution solvent was removed by vacuum distillation, and the spiropyran compound was obtained after drying; The adsorption base layer is composed of mesoporous silicon dioxide and polyethylene particles.

2. The high-adsorption cooling film for grape cultivation according to claim 1, characterized in that: The antioxidant refers to antioxidant 1010 or antioxidant 168.

3. The high-adsorption cooling film for grape cultivation according to claim 1, characterized in that: The (2) petroleum ether / ethyl acetate system elution refers to a gradient elution method, wherein the volume ratio of petroleum ether to ethyl acetate in each step of the eluent is successively 1:0, 10:1, 5:1 and 1:

1.

4. The high-adsorption cooling film for grape cultivation according to claim 1, characterized in that: The particle size of the mesoporous silica is 200 nm.

5. The method for preparing the high-adsorption cooling film for grape cultivation according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Preparation of UV-resistant oxidation layer: Anti-UV agent, antioxidant and polyethylene particles are mixed, heated and co-extruded through a twin-screw extruder, and blown into a film through a blow molding machine to obtain an UV-resistant oxidation layer with a thickness of 15-25 μm. The parameters of the twin-screw extruder are as follows: zone 1 temperature of 140-150°C, zone 2 temperature of 160-170°C, zone 3 temperature of 155-165°C, head temperature of 160°C, screw speed of 60-80 rpm, and blow molding machine parameters of a blow ratio of 2.5-3.5:1 and a draw ratio of 4-6:1; S2: Preparation of a cooling layer: Spiropyran-grafted polyethylene was heated and extruded through a twin-screw extruder and blown into a film using a blow molding machine to obtain a cooling layer with a thickness of 40-60 μm. The parameters of the twin-screw extruder were as follows: zone 1 temperature of 140-150°C, zone 2 temperature of 150-160°C, zone 3 temperature of 155-165°C, die head temperature of 155°C, screw speed of 60-80 rpm, and blow molding machine parameters of a blow-up ratio of 2.5-3.5:1 and a draw ratio of 4-6:

1. S3: Preparation of adsorption base layer: Mesoporous silica and polyethylene particles are mixed, heated and co-extruded through a twin-screw extruder, and blown into a film using a blow molding machine to obtain an adsorption base layer with a thickness of 30-40 μm. The parameters of the twin-screw extruder are as follows: zone 1 temperature of 140-150°C, zone 2 temperature of 160-170°C, zone 3 temperature of 150-160°C, die head temperature of 155°C, screw speed of 60-80 rpm, and blow molding machine parameters of a blow ratio of 2.5-3.5:1 and a draw ratio of 4-6:1; S4: stacking the anti-ultraviolet oxidation layer, the cooling layer, and the adsorption base layer in sequence from the outside to the inside, and forming the composite film by setting the temperature to 80-100°C, the pressure to 5-7MPa, and the holding time to 3-5min on a hot press. After cooling, a high-adsorption cooling film for grape cultivation is obtained.

6. The method for preparing a high-adsorption cooling film for grape cultivation according to claim 5, characterized in that: The weight ratio of the anti-ultraviolet agent, antioxidant and polyethylene particles in S1 is 0.03-0.05:0.01-0.02:

1.

7. The method for preparing a high-adsorption cooling film for grape cultivation according to claim 5, characterized in that: The weight ratio of the mesoporous silica and polyethylene particles in the S3 is 0.1-0.16:1.

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