Anti-aging light-conversion silver black mulching film and preparation method thereof

Abstract

The invention discloses an anti-aging light-conversion silver black mulching film and a preparation method thereof, and belongs to the technical field of agricultural polymer films. The preparation method comprises the following steps: S1, mixing low-density polyethylene powder, aluminum paste, a complex light conversion agent, dioctyl phthalate and EVA (Ethylene Vinyl Acetate) to prepare silver light conversion master batches; s2, vinyl-terminated fluorosilicone oil, tert-butyl peroxybenzoate and linear low-density polyethylene powder are stirred for a reaction, and modified low-density polyethylene is obtained; the modified low-density polyethylene, maleic anhydride grafted polyethylene, a multi-effect light stabilizer and polyethylene wax are subjected to banburying granulation, and modified light-stable master batches are obtained; s3, carrying out banburying granulation on the low-density polyethylene powder, the polyethylene powder, carbon black, zinc stearate, ethylene bis-stearamide and the EVA powder to obtain black master batches; s4, blending the silver layer and the black layer, and performing double-layer co-extrusion to obtain the light-conversion silver-black mulching film. The light-conversion silver black mulching film provided by the invention has good mechanical properties and aging resistance.

Description

TECHNICAL FIELD

[0001] The application discloses an anti-aging light-conversion silver-black mulching film and a preparation method thereof, and belongs to the technical field of agricultural polymer films. BACKGROUND

[0002] Agricultural mulching film is an indispensable production material in modern agriculture, and has the remarkable effects of heat preservation, soil moisture preservation, weed suppression, etc. There are mainly transparent film, black film, green film, etc. The black functional mulching film in the prior art can generally inhibit the growth of weeds, and black has faster heat absorption and heat transfer effects. When the air temperature is high in summer, the black mulching film is easy to cause excessive heat absorption, and thus the soil temperature of the covered part is too high, which may cause damage to the root system of crops.

[0003] The existing mulching film products mainly rely on color physical reflection or light shielding, and cannot actively regulate light quality to adapt to the photosynthetic needs of crops. Research shows that converting ultraviolet light with low plant utilization rate into red-orange light and blue light can significantly promote photosynthesis, but the existing light-conversion mulching film has problems such as poor compatibility of light-conversion agent and resin, easy migration, low light-conversion efficiency, and insufficient stability. The existing traditional mulching film is easy to degrade under harsh environments such as strong ultraviolet light and high temperature, resulting in a shortened service life. In addition, in the actual use scene of the mulching film, the growth environment of crops or economic crops is often very complex, and there are usually foreign matters such as straw, branches, and hardened soil on the ground, which may cause scratching damage to the mulching film, which puts higher requirements on the mechanical properties of the mulching film.

[0004] In summary, the single-color mulching film in the prior art usually has too single function, and there are still deficiencies in improving the photosynthetic efficiency of plants, material strength, and anti-aging, and functional improvement is needed. SUMMARY

[0005] In order to solve the above problems in the prior art, the application provides an anti-aging light-conversion silver-black mulching film and a preparation method thereof, and achieves the following application purposes: a silver-black light-conversion mulching film with light-conversion function, water and soil preservation, high mechanical strength, and anti-aging is prepared.

[0006] To achieve the above purposes, the technical scheme adopted is as follows: An anti-aging light-conversion silver-black mulching film has a double-layer structure of a silver layer and a black layer. The silver layer faces outward and is used for light reflection and conversion and pest repelling. The black layer faces inward and is used for light shielding, weed prevention, and soil moisture preservation.

[0007] A preparation method of an anti-aging light-conversion silver-black mulching film includes the following steps: S1. Low-density polyethylene powder, aluminum silver paste, complex light-conversion agent, dioctyl phthalate, and EVA are added to a double-screw extruder for mixing and granulation to obtain a silver light-conversion master batch.

[0008] The raw material weight ratio of the silver light-converting masterbatch is as follows: 45-60 parts of low-density polyethylene powder, 25-40 parts of aluminum silver paste, 8-14 parts of complex light-converting agent, 3-5 parts of dioctyl phthalate, and 1-3 parts of ethylene-vinyl acetate copolymer (EVA).

[0009] Furthermore, the mixing process involves controlling the mixing temperature to be 145~165℃ and the twin-screw extruder speed to be 90~120r / min.

[0010] Furthermore, the complex light-converting agent is prepared by mixing and compounding violet-to-blue light-converting powder and VTB-440 light-converting agent at a mass ratio of 1:(2~3). The violet-to-blue light-converting powder was purchased from Shandong Qishun New Materials Co., Ltd., and the VTB-440 light-converting agent was purchased from Changsha Xiweier Technology Co., Ltd.

[0011] S2. Add vinyl-terminated fluorosilicone oil and tert-butyl peroxide to a mixer, stir and disperse, add linear low-density polyethylene powder, heat and stir to react, and obtain modified low-density polyethylene. Add the modified low-density polyethylene, maleic anhydride-grafted polyethylene, multi-effect light stabilizer, and polyethylene wax to a mixer, mix, and granulate to obtain modified light-stabilized masterbatch.

[0012] The modified light-stabilized masterbatch raw materials are formulated in the following weight proportions: 90-110 parts of linear low-density polyethylene powder, 8-12 parts of vinyl-terminated fluorosilicone oil, 10-16 parts of maleic anhydride-grafted polyethylene, 0.05-0.2 parts of tert-butyl peroxide, 32-38 parts of multi-effect light stabilizer, and 2-5 parts of polyethylene wax.

[0013] Furthermore, the stirring and dispersing process involves stirring the mixture evenly at a temperature of 70-80°C.

[0014] Furthermore, the heating is raised to 110~120℃; the stirring reaction is carried out at a stirring rate of 100~400 r / min for a reaction time of 2~3 h.

[0015] Furthermore, the internal mixing process involves mixing for 10-15 minutes, controlling the mixing temperature at 150-170°C, and the internal mixer speed at 80-90 r / min.

[0016] Furthermore, the multi-effect light stabilizer is obtained by compounding light stabilizer TINUVIN XT100, light stabilizer UV-783, and antioxidant 686 in a mass ratio of 3:(1~1.5):(0.5~1).

[0017] S3. Mix low-density polyethylene powder, polyethylene powder, carbon black, zinc stearate, vinyl bis-stearamide, and EVA powder evenly, then add to a mixer and mix thoroughly. Granulate to obtain black masterbatch.

[0018] The weight proportions of the black masterbatch raw materials are as follows: 35-50 parts of low-density polyethylene powder, 10-15 parts of polyethylene powder, 20-30 parts of carbon black, 6-9 parts of zinc stearate, 0.2-0.5 parts of vinyl bis-stearamide, and 4-8 parts of EVA powder.

[0019] Furthermore, the internal mixing process involves mixing for 20-30 minutes, controlling the mixing temperature at 165-180°C, and controlling the internal mixer speed at 80-120 r / min.

[0020] S4. The silver layer ingredients are mixed according to the raw material ratio and added to the corresponding silver layer hopper of the double-layer co-extrusion equipment. The mixture is then melted through a single-screw extruder to form the silver layer melt. Similarly, the black layer ingredients are mixed according to the raw material ratio and added to the corresponding black layer hopper of the double-layer co-extrusion equipment. The mixture is then melted through a single-screw extruder to form the black layer melt. The silver and black layer melts are extruded from the co-extrusion die through a co-extrusion distributor. The extruded film is cooled by a cooling drum and then trimmed and wound to obtain the finished silver-black mulch film.

[0021] The raw material ratio of the silver layer formulation is as follows: 32-45 parts of linear low-density polyethylene granules, 10-16 parts of low-density polyethylene granules, 28-36 parts of metallocene linear low-density polyethylene granules, 9-13 parts of silver light-converting masterbatch, and 6-10 parts of modified light-stabilized masterbatch. All the parts are parts by weight.

[0022] The raw material ratio of the black layer is as follows: 44-53 parts of linear low-density polyethylene granules, 22-30 parts of metallocene linear low-density polyethylene granules, 8-15 parts of polyethylene granules, 5-10 parts of black masterbatch, 2-5 parts of modified light-stabilized masterbatch, and 2-5 parts of n-butyl stearate. All the parts are parts by weight.

[0023] Furthermore, the temperature control of each section of the single-screw extruder for the silver layer is as follows: conveying section 150~160℃, melting section 165~190℃, mixing section 170~200℃, homogenization section 175~190℃; and the screw speed is controlled at 100~150r / min.

[0024] Furthermore, the temperature control of each section of the single-screw extruder for the black layer is as follows: conveying section 150~160℃, melting section 175~200℃, mixing section 180~200℃, homogenization section 180~200℃; and the screw speed is controlled at 100~150 r / min.

[0025] The mold head has a temperature of 170~190℃.

[0026] The beneficial effects of this invention are as follows: The aging-resistant silver-black light-converting mulch film prepared by this invention has a longitudinal tensile load of 4.8~5.4N, a transverse tensile load of 4.1~4.7N, a right-angle tear load of 2.1~2.4N, and a nominal strain at break >382%, exhibiting strong mechanical properties. It also possesses strong acid and weather resistance and aging resistance, resulting in a long service life and reduced agricultural production costs. The aging-resistant silver-black light-converting mulch film prepared by this invention has a light-converting function, enabling the conversion of ultraviolet light and its reflection onto the underside of plant leaves. The synergistic effect of the light-converting components and the silver-black mulch film structure significantly improves crop growth promotion and weed control. Attached Figure Description

[0027] Figure 1 The image shows the infrared spectrum of the modified low-density polyethylene prepared in Example 1 of this invention. Analysis of the Fourier Transmission Infrared (FTIR) data revealed a characteristic Si-O-Si peak (1084 cm⁻¹). -1 ), CF characteristic peak (1256cm) -1 It can be confirmed that modified low-density polyethylene was obtained.

[0028] Figure 2 This is a diagram showing the light conversion effect of the silver-black plastic film in Embodiment 1 of the present invention under ultraviolet light irradiation.

[0029] Figure 3 This is a photograph of the actual silver-black plastic film used in Embodiment 1 of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0031] Example 1: An Aging-Resistant, Light-Converting Silver-Black Mulch Film The aging-resistant, light-converting silver-black mulch film has a double-layer structure of a silver layer and a black layer, and is manufactured by the following steps: S1. Low-density polyethylene powder, aluminum silver paste, complex brightening agent, dioctyl phthalate, and EVA are added to a twin-screw extruder for mixing. The mixing temperature is controlled at 165℃ and the twin-screw extruder speed is 100r / min. The melt obtained from mixing is granulated to obtain silver brightening masterbatch.

[0032] The weight ratio of the raw materials for preparing silver light-converting masterbatch is as follows: 60 parts low-density polyethylene powder, 40 parts aluminum silver paste, 14 parts complex light-converting agent, 3 parts dioctyl phthalate, and 3 parts EVA.

[0033] The complex light-converting agent is prepared by mixing and compounding purple-to-blue light-converting powder and VTB-440 light-converting agent at a mass ratio of 1:2.

[0034] S2. Add vinyl-terminated fluorosilicone oil and tert-butyl peroxide to a stirrer, and stir and disperse at 70°C until the system is uniformly mixed. Add linear low-density polyethylene powder, heat to 120°C, and stir at 200 r / min for 2 hours to obtain modified low-density polyethylene. Purge the system with nitrogen for 10 minutes, then add the modified low-density polyethylene, multi-effect light stabilizer, polyethylene wax, and maleic anhydride-grafted polyethylene to a mixer and mix for 10 minutes, controlling the mixing temperature at 170°C and the mixer speed at 80 r / min. The melt after mixing is granulated by a granulator to obtain modified light-stabilized masterbatch.

[0035] The modified light-stabilized masterbatch has the following raw material weight ratio: 100 parts linear low-density polyethylene powder, 10 parts vinyl-terminated fluorosilicone oil, 12 parts maleic anhydride-grafted polyethylene, 0.05 parts tert-butyl peroxide, 32 parts multi-effect light stabilizer, and 2 parts polyethylene wax.

[0036] The multi-effect light stabilizer is obtained by compounding light stabilizer TINUVIN XT100, light stabilizer UV-783, and antioxidant 686 in a mass ratio of 3:1:0.5.

[0037] S3. Mix low-density polyethylene powder, polyethylene powder, carbon black, zinc stearate, vinyl bis-stearamide, and EVA powder evenly, then add them to a mixer and mix for 30 minutes. Control the mixing temperature at 165℃ and the mixer speed at 80r / min. The melt after mixing is granulated by a granulator to obtain black masterbatch.

[0038] The raw material weight ratio of the black masterbatch is as follows: 45 parts low-density polyethylene powder, 15 parts polyethylene powder, 25 parts carbon black, 9 parts zinc stearate, 0.2 parts vinyl bis-stearamide, and 6 parts EVA powder.

[0039] S4. Mix the silver layer ingredients according to the raw material ratio and add them to the hopper of the corresponding silver layer in the double-layer co-extrusion equipment. The silver layer melt is formed by melting and blending through the single-screw extruder of the silver layer. The temperature control of each section of the single-screw extruder of the silver layer is as follows: conveying section 160℃, melting section 190℃, mixing section 200℃, homogenization section 190℃; the screw speed is 130r / min.

[0040] The black layer ingredients are mixed according to the raw material ratio and added to the corresponding black layer hopper of the double-layer co-extrusion equipment. The mixture is then melted and blended through the single-screw extruder of the black layer to form the black layer melt. The temperature control of each section of the single-screw extruder of the black layer is as follows: conveying section 150℃, melting section 200℃, mixing section 200℃, homogenization section 190℃; the screw speed is 130r / min.

[0041] The silver and black molten layers are extruded from the co-extrusion die through a co-extrusion distributor, with the die temperature controlled at 170°C. The extruded film is cooled by a cold drum and then trimmed and wound to obtain the finished silver-black mulch film.

[0042] The raw material ratio of the silver layer formulation is as follows: 45 parts of linear low-density polyethylene granules, 12 parts of low-density polyethylene granules, 32 parts of metallocene linear low-density polyethylene granules, 9 parts of silver light-converting masterbatch, and 10 parts of modified light-stabilized masterbatch. All the parts are parts by weight.

[0043] The raw material ratio of the black layer is as follows: 48 parts of linear low-density polyethylene granules, 25 parts of metallocene linear low-density polyethylene granules, 8 parts of polyethylene granules, 10 parts of black masterbatch, 5 parts of modified light-stabilized masterbatch, and 2 parts of n-butyl stearate. All the parts are parts by weight.

[0044] Example 2: An Aging-Resistant, Light-Converting Silver-Black Mulch Film The aging-resistant, light-converting silver-black mulch film has a double-layer structure of a silver layer and a black layer, and is manufactured by the following steps: S1. Low-density polyethylene powder, aluminum silver paste, complex brightening agent, dioctyl phthalate, and EVA are added to a twin-screw extruder for mixing. The mixing temperature is controlled at 160℃ and the twin-screw extruder speed is 90r / min. The melt obtained from mixing is granulated to obtain silver brightening masterbatch.

[0045] The weight ratio of the raw materials for preparing silver light-converting masterbatch is as follows: 50 parts low-density polyethylene powder, 30 parts aluminum silver paste, 10 parts complex light-converting agent, 5 parts dioctyl phthalate, and 1 part EVA.

[0046] The complex light-converting agent is prepared by mixing and compounding purple-to-blue light-converting powder and VTB-440 light-converting agent at a mass ratio of 1:3.

[0047] S2. Add vinyl-terminated fluorosilicone oil and tert-butyl peroxide to a stirrer and stir until the system is uniformly mixed at 70°C. Add linear low-density polyethylene powder, heat to 110°C, and stir at 400 r / min for 3 hours to obtain modified low-density polyethylene. Purge the system with nitrogen for 10 minutes, then add the modified low-density polyethylene, multi-effect light stabilizer, polyethylene wax, and maleic anhydride-grafted polyethylene to a mixer and mix for 15 minutes, controlling the mixing temperature at 150°C and the mixer speed at 80 r / min. The melt after mixing is granulated using a granulator to obtain modified light-stabilized masterbatch.

[0048] The modified light-stabilized masterbatch has the following raw material weight ratio: 110 parts linear low-density polyethylene powder, 8 parts vinyl-terminated fluorosilicone oil, 16 parts maleic anhydride-grafted polyethylene, 0.2 parts tert-butyl peroxide, 32 parts multi-effect light stabilizer, and 5 parts polyethylene wax.

[0049] The multi-effect light stabilizer is obtained by compounding light stabilizer TINUVIN XT100, light stabilizer UV-783, and antioxidant 686 in a mass ratio of 3:1:1.

[0050] S3. Mix low-density polyethylene powder, polyethylene powder, carbon black, zinc stearate, vinyl bis-stearamide, and EVA powder evenly, then add them to a mixer and mix for 20 minutes. Control the mixing temperature at 180℃ and the mixer speed at 120r / min. The melt after mixing is granulated by a granulator to obtain black masterbatch.

[0051] The raw material weight ratio of the black masterbatch is as follows: 35 parts low-density polyethylene powder, 10 parts polyethylene powder, 20 parts carbon black, 7 parts zinc stearate, 0.3 parts vinyl bis-stearamide, and 8 parts EVA powder.

[0052] S4. Mix the silver layer ingredients according to the raw material ratio and add them to the corresponding silver layer hopper of the double-layer co-extrusion equipment. The silver layer melt is formed by melting and blending through the single-screw extruder of the silver layer. The temperature control of each zone of the single-screw extruder of the silver layer is as follows: conveying section 160℃, melting section 180℃, mixing section 180℃, homogenization section 180℃; the screw speed is 100r / min.

[0053] The black layer ingredients are mixed according to the raw material ratio and added to the corresponding black layer hopper of the double-layer co-extrusion equipment. The mixture is then melted and blended through the single-screw extruder of the black layer to form the black layer melt. The temperature control of each section of the single-screw extruder of the black layer is as follows: conveying section 150℃, melting section 180℃, mixing section 190℃, homogenization section 200℃; the screw speed is 100r / min.

[0054] The raw material ratio of the silver layer formulation is as follows: 40 parts linear low-density polyethylene granules, 16 parts low-density polyethylene granules, 36 parts metallocene linear low-density polyethylene granules, 13 parts silver light-converting masterbatch, and 6 parts modified light-stabilized masterbatch. All parts are by weight.

[0055] The raw material ratio of the black layer formulation is as follows: 44 parts linear low-density polyethylene granules, 22 parts metallocene linear low-density polyethylene granules, 10 parts polyethylene granules, 5 parts black masterbatch, 2 parts modified light-stabilized masterbatch, and 3 parts n-butyl stearate. All parts are by weight.

[0056] The silver and black molten layers are extruded from the co-extrusion die through a co-extrusion distributor, with the die temperature controlled at 190°C. The extruded film is cooled by a cold drum and then trimmed and wound to obtain the finished silver-black mulch film.

[0057] Example 3: An Aging-Resistant, Light-Converting Silver-Black Mulch Film The aging-resistant, light-converting silver-black mulch film has a double-layer structure of a silver layer and a black layer, and is manufactured by the following steps: S1. Low-density polyethylene powder, aluminum silver paste, complex brightening agent, dioctyl phthalate, and EVA are added to a twin-screw extruder for mixing. The mixing temperature is controlled at 145℃ and the twin-screw extruder speed is 120r / min. The melt obtained from mixing is granulated to obtain silver brightening masterbatch.

[0058] The weight ratio of the raw materials for preparing silver light-converting masterbatch is as follows: 45 parts low-density polyethylene powder, 25 parts aluminum silver paste, 8 parts complex light-converting agent, 4 parts dioctyl phthalate, and 1 part EVA.

[0059] The complex light-converting agent is prepared by mixing and compounding purple-to-blue light-converting powder and VTB-440 light-converting agent at a mass ratio of 1:3.

[0060] S2. Add vinyl-terminated fluorosilicone oil and tert-butyl peroxide to a stirrer and stir until the system is uniformly mixed at 80°C. Add linear low-density polyethylene powder, heat to 110°C, and stir at 100 r / min for 2 hours to obtain modified low-density polyethylene. Purge the system with nitrogen for 10 minutes, then add the modified low-density polyethylene, multi-effect light stabilizer, polyethylene wax, and maleic anhydride-grafted polyethylene to a mixer and mix for 15 minutes, controlling the mixing temperature at 150°C and the mixer speed at 90 r / min. The melt after mixing is granulated using a granulator to obtain modified light-stabilized masterbatch.

[0061] The modified light-stabilized masterbatch has the following raw material weight ratio: 90 parts linear low-density polyethylene powder, 12 parts vinyl-terminated fluorosilicone oil, 10 parts maleic anhydride-grafted polyethylene, 0.1 parts tert-butyl peroxide, 38 parts multi-effect light stabilizer, and 5 parts polyethylene wax.

[0062] The multi-effect light stabilizer is prepared by compounding light stabilizer TINUVIN XT100, light stabilizer UV-783, and antioxidant 686 in a mass ratio of 3:1.5:1. Light stabilizer 1 is TINUVIN XT100; light stabilizer 2 is UV-783; and antioxidant 686 is antioxidant 686.

[0063] S3. Mix low-density polyethylene powder, polyethylene powder, carbon black, zinc stearate, vinyl bis-stearamide, and EVA powder evenly, then add them to a mixer and mix for 20 minutes. Control the mixing temperature at 175℃ and the mixer speed at 100r / min. The melt after mixing is granulated by a granulator to obtain black masterbatch.

[0064] The raw material weight ratio of the black masterbatch is as follows: 50 parts low-density polyethylene powder, 15 parts polyethylene powder, 30 parts carbon black, 6 parts zinc stearate, 0.5 parts vinyl bis-stearamide, and 4 parts EVA powder.

[0065] S4. Mix the silver layer ingredients according to the raw material ratio and add them to the corresponding silver layer hopper of the double-layer co-extrusion equipment. The silver layer melt is formed by melting and blending through the single-screw extruder of the silver layer. The temperature control of each section of the single-screw extruder of the silver layer is as follows: conveying section 150℃, melting section 165℃, mixing section 170℃, homogenization section 175℃; the screw speed is 150r / min.

[0066] The black layer ingredients are mixed according to the raw material ratio and added to the corresponding black layer hopper of the double-layer co-extrusion equipment. The mixture is then melted and blended through the single-screw extruder of the black layer to form the black layer melt. The temperature control of each section of the single-screw extruder of the black layer is as follows: conveying section 160℃, melting section 175℃, mixing section 180℃, homogenization section 180℃; the screw speed is 150r / min.

[0067] The silver and black molten layers are extruded from the co-extrusion die through a co-extrusion distributor, with the die temperature controlled at 175°C. The extruded film is cooled by a cold drum and then trimmed and wound to obtain the finished silver-black mulch film.

[0068] The raw material ratio for the silver layer formulation is as follows: 32 parts linear low-density polyethylene granules, 10 parts low-density polyethylene granules, 28 parts metallocene linear low-density polyethylene granules, 13 parts silver light-converting masterbatch, and 6 parts modified light-stabilizing masterbatch are added to a mixer and mixed evenly. All parts are by weight.

[0069] The raw material ratio for the black layer formulation is as follows: 53 parts of linear low-density polyethylene granules, 30 parts of metallocene linear low-density polyethylene granules, 15 parts of polyethylene granules, 10 parts of black masterbatch, 3 parts of modified light-stabilized masterbatch, and 5 parts of n-butyl stearate are added to a mixer and mixed evenly. All parts are by weight.

[0070] Performance testing The performance of the silver-black mulch films obtained in Examples 1-3 was tested, and the test results are shown in Table 1. The silver-black mulch films obtained in Examples 1-3 were subjected to aging treatment and then performance tests were conducted, and the test results are shown in Table 2. The silver-black mulch films obtained in Examples 1-3 were subjected to acid weathering resistance treatment and then performance tests were conducted, and the test results are shown in Table 3.

[0071] Performance testing methods: The silver-black mulch film was subjected to tensile load, nominal strain at break, and right-angle tear load tests according to the test methods provided in "Polyethylene blown agricultural ground covering film" (GB 13735-2017).

[0072] Photoaging treatment method: The light was aged for 300 hours according to the treatment method in "Laboratory Light Source Exposure Test Methods for Plastics Part 3: Fluorescent Ultraviolet Lamps" (GB / T 16422.3-2022), simulating approximately 6 months of use under natural conditions; the aging lamp box parameters were set as follows: the irradiation wavelength of the fluorescent ultraviolet lamp was 340nm, and the irradiation intensity was 0.55W / m². 2 Temperature 60℃, relative humidity 80%.

[0073] Acid-resistant weathering treatment method: Use a 0.5% acetic acid solution to circulate and spray the mulch film at a flow rate of 50 mL / (m²). 2 ·min), rinsing contact time 168h.

[0074] Table 1 Performance Test Results Table 2 Performance test results after photoaging treatment Table 3 Results of performance tests after acid weathering treatment Analysis of the data in Table 1 shows that the silver-black to light-converting mulch film prepared by this invention has a longitudinal tensile load of 4.8~5.4N, a transverse tensile load of 4.1~4.7N, a right-angle tear load of 2.1~2.4N, and a nominal strain at break of >382%, indicating that it has strong mechanical properties.

[0075] Analysis of the data in Table 2 shows that the longitudinal tensile load of the mulch film after photoaging treatment is 4.5~5.1N, the transverse tensile load is 3.9~4.4N, and the right-angle tear load is 2~2.3N. Compared with the mulch film without photoaging treatment, the retention rate of longitudinal tensile load is 93.75~94.44%, the retention rate of transverse tensile load is 93.18~95.12%, and the retention rate of right-angle tear load is 90.91~95.83%. Analysis of the data in Table 3 shows that the acid weather resistance... The treated mulch film has a longitudinal tensile load of 4.4~4.9N, a transverse tensile load of 3.8~4.2N, and a right-angle tear load of 1.9~2.2N. Compared with the mulch film that has not undergone acid weathering treatment, the longitudinal tensile load retention rate is 90~92.68%, the transverse tensile load retention rate is 90.91~92.68%, and the right-angle tear load retention rate is 90.48~95.45%. The above results show that the silver-black light-converting mulch film provided by the present invention not only has strong aging resistance but also good acid weathering resistance.

[0076] Obviously, there are many other possible implementation methods under the concept of this invention. It should be stated here that any changes made under the inventive concept of this invention will fall within the protection scope of this invention.

Claims

1. A method for preparing an aging-resistant, light-converting, silver-black mulch film, characterized in that: The preparation method comprises the following steps: S1, mixing low-density polyethylene powder, aluminum silver paste, complex light conversion agent, dioctyl phthalate and EVA to prepare silver light conversion master batch; the complex light conversion agent comprises purple-to-blue light conversion powder and VTB-440 light conversion agent; S2, stirring and dispersing end-vinyl fluorosilicone oil and tert-butyl peroxybenzoate, adding linear low-density polyethylene powder, heating and stirring to react, to obtain modified low-density polyethylene; mixing the modified low-density polyethylene with maleic anhydride grafted polyethylene, multi-effect light stabilizer and polyethylene wax, granulating to obtain modified light stabilization master batch; S3, mixing low-density polyethylene powder, polyethylene powder, carbon black, zinc stearate, vinyl bis-stearamide and EVA powder, granulating to obtain black master batch; S4, co-extruding silver layer ingredients and black layer ingredients to obtain light conversion silver black mulch; the silver layer ingredients and the black layer ingredients both comprise modified light stabilization master batch.

2. The preparation method of the anti-aging light conversion silver black mulch according to claim 1, characterized in that: the silver layer ingredients comprise the following components: linear low-density polyethylene particles, low-density polyethylene particles, metallocene linear low-density polyethylene particles, silver light conversion master batch and modified light stabilization master batch; the black layer ingredients comprise the following components: linear low-density polyethylene particles, metallocene linear low-density polyethylene particles, polyethylene particles, black master batch, modified light stabilization master batch and n-butyl stearate.

3. The preparation method of the anti-aging light-conversion silver-black mulch film according to claim 1, characterized in that: the weight ratio of the components of the silver layer ingredients is: 32-45 parts of linear low-density polyethylene particles, 10-16 parts of low-density polyethylene particles, 28-36 parts of metallocene linear low-density polyethylene particles, 9-13 parts of silver light conversion master batch and 6-10 parts of modified light stabilization master batch; the weight ratio of the components of the black layer ingredients is: 44-53 parts of linear low-density polyethylene particles, 22-30 parts of metallocene linear low-density polyethylene particles, 8-15 parts of polyethylene particles, 5-10 parts of black master batch, 2-5 parts of modified light stabilization master batch and 2-5 parts of n-butyl stearate.

4. The preparation method of the anti-aging light conversion silver black mulch according to claim 1, characterized in that: the weight ratio of the raw materials of the silver light conversion master batch is: 45-60 parts of low-density polyethylene powder, 25-40 parts of aluminum silver paste, 8-14 parts of complex light conversion agent, 3-5 parts of dioctyl phthalate and 1-3 parts of ethylene-vinyl acetate copolymer; the weight ratio of the raw materials for preparing the modified light stabilization master batch is: 90-110 parts of linear low-density polyethylene powder, 8-12 parts of end-vinyl fluorosilicone oil, 10-16 parts of maleic anhydride grafted polyethylene, 0.05-0.2 parts of tert-butyl peroxybenzoate, 32-38 parts of multi-effect light stabilizer and 2-5 parts of polyethylene wax; the weight ratio of the raw materials for preparing the black master batch is: 35-50 parts of low-density polyethylene powder, 10-15 parts of polyethylene powder, 20-30 parts of carbon black, 6-9 parts of zinc stearate, 0.2-0.5 parts of vinyl bis-stearamide and 4-8 parts of EVA powder.

5. The preparation method of the anti-aging light-conversion silver-black mulch film according to claim 1, characterized in that: The complex light conversion agent is prepared by mixing and compounding purple-to-blue light conversion powder and VTB-440 light conversion agent in a mass ratio of 1:(2-3); the multi-effect light stabilizer is prepared from raw materials including light stabilizer TINUVIN XT100, light stabilizer UV-783, antioxidant 686, and the mass ratio of light stabilizer TINUVIN XT100, light stabilizer UV-783, and antioxidant 686 is 3:(1-1.5):(0.5-1).

6. The preparation method of the aging-resistant light-conversion silver-black mulch film according to claim 1, characterized in that: In step S1, the mixing temperature is 145-165 DEG C; In step S2, the stirring and dispersing is performed at 70-80 DEG C; In step S2, the temperature is raised to 110-120 DEG C; In step S2, the stirring reaction is performed at a stirring rate of 100-400 r / min for 2-3 h; In step S2, the mixing is controlled for 10-15 min at a temperature of 150-170 DEG C and a rotating speed of 80-90 r / min.

7. The preparation method of the anti-aging light-conversion silver-black mulch film according to claim 1, characterized in that: In step S3, the mixing is controlled for 20-30 min at a temperature of 165-180 DEG C and a rotating speed of 80-120 r / min.

8. The preparation method of the anti-aging light-conversion silver-black mulch film according to claim 1, characterized in that: In step S4, the double-layer co-extrusion is performed by mixing the silver layer ingredients according to the raw material ratio, adding them into the hopper corresponding to the silver layer of the double-layer co-extrusion equipment, melting the silver layer melt through the single-screw extruder of the silver layer, mixing the black layer ingredients according to the raw material ratio, adding them into the hopper corresponding to the black layer of the double-layer co-extrusion equipment, melting the black layer melt through the single-screw extruder of the black layer, and extruding the silver layer melt and the black layer melt from the co-extrusion die through the co-extrusion distributor.

9. The preparation method of the anti-aging light-conversion silver-black mulch film according to claim 8, characterized in that: The single-screw extruder of the silver layer has a temperature control of 150-160 DEG C for the conveying section, 165-190 DEG C for the melting section, 170-200 DEG C for the mixing section, and 175-190 DEG C for the homogenizing section; the single-screw extruder of the black layer has a temperature control of 150-160 DEG C for the conveying section, 175-200 DEG C for the melting section, 180-200 DEG C for the mixing section, and 180-200 DEG C for the homogenizing section; and the die has a temperature of 170-190 DEG C.

10. An anti-aging light-converting silver-black mulch film, characterized in that: Prepared by the preparation method of any one of claims 1-9.

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