Agricultural greenhouse film capable of converting ultraviolet-green light into blue-red spectrum and preparation method of agricultural greenhouse film

Abstract

The invention relates to the technical field of agricultural seedling growing greenhouses, in particular to an agricultural greenhouse film capable of converting ultraviolet-green light into blue-red spectrum and a preparation method thereof.The agricultural greenhouse film capable of converting ultraviolet-green light into blue-red spectrum sequentially comprises an outer organic layer, a light conversion layer, an inner organic layer and an anti-fog light-transmitting layer; the outer organic layer is prepared from 30 to 40 percent of metallocene polyethylene (mLLDPE), 30 to 50 percent of ethylene-vinyl acetate copolymer (EVA), 30 to 50 percent of low density polyethylene (LDPE), 3 to 5 percent of light stabilizer, 2 to 3 percent of ultraviolet light absorber and 1 to 4 percent of antioxidant; the light conversion layer comprises 80-90% of LDPE (Low-Density Polyethylene), 20-30% of LLDPE (Linear Low-Density Polyethylene) and 1-1.5% of a light conversion agent; the inner organic layer comprises 30 to 40 percent of EVA (Ethylene Vinyl Acetate), 20 to 35 percent of LDPE (Low-Density Polyethylene) and 20 to 35 percent of The agricultural seedling growing greenhouse prepared by the invention has a good lasting anti-fog effect under the condition of not influencing the light transmission, and is beneficial to the growth and development of crops.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of agricultural seedling raising greenhouse, and particularly relates to an agricultural greenhouse film with a spectrum of ultraviolet-green light converted into blue-red light and a preparation method thereof. BACKGROUND

[0002] As the most widely used greenhouse film material in the world, the fogging problem of polyethylene film seriously affects the light transmittance and the healthy growth of crops. Polyethylene (PE) has superior properties, such as high transparency, good chemical stability, excellent waterproof and insulating properties, and low cost, so it is widely used in various fields such as agriculture, communication cable, packaging and building.

[0003] In the field of agriculture, PE film is often used as greenhouse film to build an environment with an average relative humidity of 60-90% to ensure the continuous growth of plants. The surface tension of polyethylene is much lower than that of water, and it has high hydrophobicity, which leads to the condensation of fog inside the greenhouse film. The temperature difference between the inside and outside of the greenhouse will cause water vapor to hit the inner surface of the greenhouse film and continue to condense. SUMMARY

[0004] The purpose of the present application is to provide an agricultural greenhouse film with a spectrum of ultraviolet-green light converted into blue-red light and a preparation method thereof, which solves the technical problem of easy fogging and condensation of the existing agricultural greenhouse film.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] The technical scheme provided by the present application is as follows:

[0007] In the first aspect, the present application provides an agricultural greenhouse film with a spectrum of ultraviolet-green light converted into blue-red light, which specifically comprises the following components by weight:

[0008] The agricultural greenhouse film with a spectrum of ultraviolet-green light converted into blue-red light comprises an outer organic layer, a light conversion layer, an inner organic layer and an anti-fogging and light-transmitting layer in sequence; the outer organic layer comprises metallocene polyethylene (mLLDPE) 30-40%, ethylene-vinyl acetate copolymer (EVA) 30-50%, low-density polyethylene (LDPE) 30-50%, light stabilizer 3-5%, ultraviolet absorber 2-3% and antioxidant 1-4%; the light conversion layer is LDPE 80-90%, LLDPE 20-30% and light conversion agent 1-1.5%; the inner organic layer comprises EVA 30-40%, LDPE 20-35% and LLDPE 20-35%.

[0009] Preferably, the light stabilizer comprises one of 622 or 944; and the ultraviolet absorber comprises one of UV-531 or UV-630.

[0010] Preferably, the antioxidant is B215; the light conversion agent is an organic synthetic rare earth light conversion agent, the rare earth component is di-europium trioxide, and the organic component is o-hydroxybenzoic acid; the VA content of the EVA is 4-9%.

[0011] Preferably, the thickness of the outer organic layer and the inner organic layer is 20-40 μm; the thickness of the light conversion layer is 40-60 μm; the thickness of the durable outer layer is 15-25 μm; the thickness of the light conversion layer is 30-60 μm; and the thickness of the anti-fog light transmission layer is 15-20 μm.

[0012] In a second aspect, the present application further provides a preparation method of the agricultural greenhouse film with ultraviolet-green light converted blue-red spectrum, comprising the following steps:

[0013] Step (1): according to the formula of the organic outer layer, the light conversion layer and the organic inner layer, pour various raw materials into a mixer, stir uniformly, then pass the raw materials into the hopper of an extruder through a suction machine, pass them through the shearing and heating of various layer barrels, then pass them through the connecting body of the barrels to the head, lift the raw materials extruded from the head to the traction, and blow them at the same time to obtain a three-layer film;

[0014] Step (2): carry out corona treatment on the inner organic layer of the three-layer film, then coat an anti-fog liquid, irradiate under an ultraviolet lamp, and solidify to obtain the agricultural greenhouse film with ultraviolet-green light converted blue-red spectrum.

[0015] In the above process, the polyethylene is treated by corona treatment, and many polar groups can be generated on the surface of the polyethylene. The benzophenone groups of the grafted PVA side chain act as light anchoring agents, which can be excited to the reactive triplet state (n-π*) under ultraviolet light excitation, and can capture hydrogen atoms on the surface of the polyethylene to generate free radical active sites. The coating is firmly bonded to the polyethylene substrate through chemical covalent bonds, which significantly improves the water resistance, stability and adhesion.

[0016] Preferably, the corona treatment method is: 2kW·min / m 2 Corona for 5 seconds.

[0017] Preferably, the irradiation method under the ultraviolet lamp is: irradiation under a 365 nm wavelength, 1000 W power ultraviolet lamp for 1 min; and the solidification method is: solidification at 45-55℃ for 10-14 h.

[0018] Preferably, the preparation method of the anti-fog liquid comprises the following steps:

[0019] P1: dissolve N,N'-carbonyl diimidazole, 4,4'-diamino benzophenone and triethylamine in dimethyl sulfoxide, and stir at room temperature to obtain a mixed solution;

[0020] The structural formula of the reaction product of N,N'-carbonyl diimidazole and 4,4'-diamino benzophenone is as follows:

[0021]

[0022] P2: adding the mixed solution into dimethyl sulfoxide containing polyvinyl alcohol (PVA), stirring and reacting, precipitating with anhydrous acetone at room temperature, drying to obtain grafted PVA;

[0023] In the above process, the hydroxyl group of PVA is replaced by imidazole group to obtain grafted PVA.

[0024] P3: dissolving grafted PVA, 5-sulfosalicylic acid dihydrate and ammonium persulfate in water, stirring and treating to obtain an anti-fog solution.

[0025] Preferably, in P1, the amount ratio of N,N'-carbonyldiimidazole, 4,4'-diaminobenzophenone, triethylamine and dimethyl sulfoxide is 7.3-14.6 g:8.9-18 g:4.5-9 g:200-400 mL; the stirring and reacting time is 2-4 h.

[0026] Preferably, in P2, the amount ratio of polyvinyl alcohol (PVA) and dimethyl sulfoxide is 400-800 g:4-8 L; the stirring and reacting method is stirring and reacting at 55-65 °C under nitrogen atmosphere for 10-14 h; the drying method is drying at 40-50 °C for 40-52 h; the degree of substitution of grafted PVA is 0.5-1.5%.

[0027] Preferably, in P3, the amount ratio of grafted PVA, 5-sulfosalicylic acid dihydrate, ammonium persulfate and water is 100-200 g:9-18 g:7-14 g:1.1-2.2 L; the stirring and treating method is stirring and treating at 85-95 °C for 3-5 h.

[0028] In summary, due to the adoption of the above technical solutions, the application has the following advantages:

[0029] In the application, the hydroxyl group of PVA and 5-sulfosalicylic acid provide basic hydrophilicity, jointly optimize surface energy, adsorb water molecules to form a transparent water film, benzophenone is photo-anchored, and based on the strong hydrogen bond interaction between PVA molecules and the cross-linking effect of ammonium persulfate on PVA in hot state, the anti-friction and thermal stability are improved, the formation of fog droplets is inhibited, swelling is inhibited, and the anti-fog life is prolonged; through light conversion technology, green light is converted into red light or blue light which is more easily absorbed by plants, photosynthesis is promoted, light transmission and prevention of water droplets in the film are realized through the greenhouse film, diseases are reduced, and the growth and development of crops are enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim to explain some of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without any creative effort based on these drawings.

[0031] Figure 1 is a preparation process flow chart of the agricultural greenhouse film of the present application with ultraviolet-green light converted into blue-red light spectrum;

[0032] Figure 2 is a light transmission column chart of the agricultural greenhouse film of the present application with ultraviolet-green light converted into blue-red light spectrum. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0034] Embodiment 1

[0035] The present embodiment discloses a preparation method of an anti-fogging liquid, comprising the following steps:

[0036] P1: 9.2 g of N,N'-carbonyl diimidazole, 12.5 g of 4,4'-diamino benzophenone and 7.5 g of triethylamine were dissolved in 300 mL of dimethyl sulfoxide, and the mixture was stirred at room temperature for 3 h to obtain a mixed solution;

[0037] P2: the mixed solution was added into a 6 L dimethyl sulfoxide solution containing 600 g of polyvinyl alcohol (PVA), and the mixture was stirred at 60°C under a nitrogen atmosphere for 12 h, and then was allowed to settle at room temperature using anhydrous acetone, and was dried at 45°C for 48 h to obtain grafted PVA;

[0038] P3: 150 g of the grafted PVA, 14 g of 5-sulfosalicylic acid dihydrate and 10 g of ammonium persulfate were dissolved in 1.6 L of water, and the mixture was stirred at 90°C for 4 h to obtain an anti-fogging liquid.

[0039] Embodiment 2

[0040] The present embodiment discloses a preparation method of an anti-fogging liquid, comprising the following steps:

[0041] P1: 7.3 g of N,N'-carbonyl diimidazole, 18 g of 4,4'-diamino benzophenone and 4.5 g of triethylamine were dissolved in 400 mL of dimethyl sulfoxide, and the mixture was stirred at room temperature for 2 h to obtain a mixed solution;

[0042] P2: The mixed solution was added to 4 L of dimethyl sulfoxide solution containing 800 g of PVA, stirred and reacted at 65 ° C in a nitrogen atmosphere for 10 h, precipitated with anhydrous acetone at room temperature, and dried at 50 ° C for 40 h to obtain grafted PVA;

[0043] P3: 200 g of grafted PVA, 9 g of 5-sulfosalicylic acid dihydrate and 14 g of ammonium persulfate were dissolved in 1.1 L of water and stirred at 95° C. for 3 h to obtain an antifog liquid.

[0044] Example 3

[0045] This embodiment discloses a method for preparing an anti-fog liquid, comprising the following steps:

[0046] P1: 14.6 g of N,N'-carbonyldiimidazole, 8.9 g of 4,4'-diaminobenzophenone and 9 g of triethylamine were dissolved in 200 mL of dimethyl sulfoxide, and the mixture was stirred at room temperature for 4 h to obtain a mixed solution;

[0047] P2: The mixed solution was added to 8 L of dimethyl sulfoxide solution containing 400 g of PVA, stirred and reacted at 55°C in a nitrogen atmosphere for 14 h, precipitated with anhydrous acetone at room temperature, and dried at 40°C for 52 h to obtain grafted PVA;

[0048] P3: 100 g of grafted PVA, 18 g of 5-sulfosalicylic acid dihydrate, and 7 g of ammonium persulfate were dissolved in 2.2 L of water and stirred at 85° C. for 5 h to obtain an antifog solution.

[0049] Example 4

[0050] See Figure 1 As shown, this embodiment discloses a method for preparing an agricultural greenhouse film that converts ultraviolet-green light into blue-red spectrum, comprising the following steps:

[0051] Step (1) various raw materials are poured into a blender according to the formula of the organic outer layer, the light-converting layer, and the organic inner layer, and after being evenly stirred, the raw materials are sucked into the hopper of the extruder through a suction machine, and after shear heating in each layer of the barrel, the raw materials are passed through the connector of the barrel to reach the head, and the raw materials extruded from the head are lifted to be traction and inflated at the same time to obtain a three-layer film;

[0052] Step (2) The inner organic layer of the three-layer membrane is heated at 2kW·min / m 2 After corona treatment for 5 seconds, the anti-fog liquid prepared in Example 1 was coated and irradiated under a UV lamp with a wavelength of 365 nm and a power of 1000 W for 1 minute, and then cured at 50° C. for 12 hours to obtain an agricultural greenhouse film with a UV-green light to blue-red spectrum.

[0053] The outer organic layer comprises mLLDPE 35%, EVA 40%, LDPE 40%, light stabilizer 4%, ultraviolet absorber 2.5%, antioxidant 2.5%;

[0054] The light conversion layer comprises LDPE 85%, LLDPE 25%, light conversion agent 1.2%;

[0055] The inner organic layer comprises EVA 35%, LDPE 27%, LLDPE 37%;

[0056] The light stabilizer is 622; the ultraviolet absorber is UV-531; the antioxidant is B215; and the light conversion agent is an organic synthetic rare earth light conversion agent, the rare earth component of which is europium sesquioxide, and the organic component of which is o-hydroxybenzoic acid.

[0057] Example 5

[0058] Referring to Figure 1 The preparation method of the agricultural greenhouse film disclosed in the embodiment converts ultraviolet-green light into blue-red spectrum, and comprises the following steps:

[0059] Step (1) According to the formula of the outer organic layer, the light conversion layer, and the inner organic layer, various raw materials are poured into a mixer, stirred uniformly, and then poured into the hopper of an extruder through a suction machine. After being sheared and heated by the barrel of each layer, the raw materials reach the machine head through the connecting body of the barrel. The raw materials extruded from the machine head are lifted to the traction, and at the same time, the three-layer film is obtained by blowing.

[0060] Step (2) The inner organic layer of the three-layer film is coated with a 2kW·min / m 2 After corona treatment for 5 seconds, the agricultural greenhouse film is prepared by coating the anti-fogging liquid prepared in Example 2, irradiating under a 365nm wavelength ultraviolet lamp with a power of 1000W for 1min, and then curing at 45℃ for 14h to obtain an agricultural greenhouse film that converts ultraviolet-green light into blue-red spectrum.

[0061] The outer organic layer comprises metallocene polyethylene (mLLDPE) 30%, ethylene-vinyl acetate copolymer (EVA) 50%, low-density polyethylene (LDPE) 30%, light stabilizer 5%, ultraviolet absorber 2%, and antioxidant 4%;

[0062] The light conversion layer comprises LDPE 80%, LLDPE 30%, and light conversion agent 1%;

[0063] The inner organic layer comprises EVA 40%, LDPE 20%, and LLDPE 35%;

[0064] The light stabilizer is 944; the ultraviolet absorber is UV-630; the antioxidant is B215; and the light conversion agent is an organic synthetic rare earth light conversion agent, the rare earth component of which is europium sesquioxide, and the organic component of which is o-hydroxybenzoic acid.

[0065] Example 6

[0066] Referring to Figure 1 The embodiment discloses a preparation method of an ultraviolet-green-to-blue-red spectrum agricultural greenhouse film, and comprises the following steps:

[0067] Step (1) according to the formula of the organic outer layer, the light conversion layer and the organic inner layer, various raw materials are poured into a blender, after being uniformly stirred, the raw materials are sucked into the hopper of an extruder through a suction machine, and then pass through the shearing and heating of various layer barrels and the connecting body of the barrels to reach the head, the raw materials extruded from the head are lifted to reach the traction, and at the same time, the blowing is carried out, so that the three-layer film is obtained;

[0068] Step (2) the inner organic layer of the three-layer film is coated with a 2kW·min / m 2 The outer organic layer is subjected to corona treatment for 5 seconds, then the anti-fogging liquid prepared in Example 3 is coated, and then the film is irradiated under an ultraviolet lamp with a wavelength of 365 nm and a power of 1000 W for 1 min, and then the film is cured at 55℃ for 10 h, so that the ultraviolet-green-to-blue-red spectrum agricultural greenhouse film is obtained.

[0069] The outer organic layer comprises metallocene polyethylene (mLLDPE) 40%, ethylene-vinyl acetate copolymer (EVA) 30%, low-density polyethylene (LDPE) 50%, light stabilizer 3%, ultraviolet absorber 3% and antioxidant 1%;

[0070] The light conversion layer comprises LDPE 90%, LLDPE 20% and light conversion agent 1.5%;

[0071] The inner organic layer comprises EVA 30%, LDPE 35% and LLDPE 20%;

[0072] The light stabilizer is 622; the ultraviolet absorber is UV-531; the antioxidant is B215; and the light conversion agent is an organic synthetic rare earth light conversion agent, the rare earth component of which is europium sesquioxide, and the organic component of which is o-hydroxybenzoic acid.

[0073] Comparative Example 1

[0074] Comparative Example 1 is compared with Example 1, and in the preparation process of the ultraviolet-green-to-blue-red spectrum agricultural greenhouse film, no anti-fogging liquid is coated in Comparative Example 1, and other conditions are unchanged.

[0075] The properties of the ultraviolet-green-to-blue-red spectrum agricultural greenhouse films of Examples 4-6 and Comparative Example 1 are tested, and the test results are shown in Table 1:

[0076] The light transmittance is measured by using a luminometer; and the tensile test is tested according to the standard of ASTM D882-02;

[0077] The light transmittance was measured using a UV-visible spectrometer (UV-1900); the anti-fog performance was evaluated by a hot steam method and a freeze-warm method, the UV-green-to-blue-red spectrum agricultural greenhouse film was placed above a 80℃ hot water beaker for 30 min, the surface state change of the substrate was observed and recorded; the freeze-warm anti-fog experiment was performed, the UV-green-to-blue-red spectrum agricultural greenhouse film was placed in a-20℃ environment for 1 hour, and then was transferred to a room temperature (relative humidity 70%) environment, the surface fogging condition was observed and recorded.

[0078] Table 2

[0079]

[0080] According to Table 1 and from Examples 3-5 and Comparative Example 1, the UV-green-to-blue-red spectrum agricultural greenhouse film prepared according to the present application has good light transmittance and anti-fog effect. It can be seen from the comparison of Comparative Example 1 and Examples 3-6 that coating the anti-fog liquid can improve the anti-fog effect of the UV-green-to-blue-red spectrum agricultural greenhouse film and has little effect on the light transmittance.

[0081] The above description is only the preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical scope disclosed by the present application, and all of them should be covered within the protection scope of the present application.

[0082] The above disclosed preferred embodiments of the present application are only used to help explain the present application. The preferred embodiments do not describe all the details, and do not limit the present application to only the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that the person skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their entire scope and equivalents.

Claims

1. An agricultural greenhouse film that converts ultraviolet-green light into blue-red spectrum, characterized in that: The agricultural greenhouse film that converts ultraviolet-green light into blue-red spectrum includes an outer organic layer, a light conversion layer, an inner organic layer and an anti-fog and light-transmitting layer in sequence; the outer organic layer includes 30-40% metallocene polyethylene (mLLDPE), 30-50% ethylene-vinyl acetate copolymer (EVA), 30-50% low-density polyethylene (LDPE), 3-5% light stabilizer, 2-3% ultraviolet absorber, and 1-4% antioxidant; the light conversion layer is 80-90% LDPE, 20-30% LLDPE, and 1-1.5% light conversion agent; the inner organic layer includes 30-40% EVA, 20-35% LDPE, and 20-35% LLDPE.

2. The agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 1, characterized in that The light stabilizer includes one of 622 or 944.

3. The agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 1, characterized in that The ultraviolet absorber includes one of UV-531 and UV-630; the antioxidant is B215.

4. The agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 1, characterized in that The light conversion agent is an organic synthetic rare earth light conversion agent, the rare earth component is europium trioxide, and the organic component is o-hydroxybenzoic acid; the VA content of EVA is 4-9%.

5. The agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 1, characterized in that The thickness of the outer organic layer and the inner organic layer is 20-40 μm; the thickness of the light conversion layer is 40-60 μm; the thickness of the durable outer layer is 15-25 μm; the thickness of the light conversion layer is 30-60 μm; and the thickness of the anti-fog and light-transmitting layer is 15-20 μm.

6. A method for preparing an agricultural greenhouse film with ultraviolet-green light converted to blue-red spectrum according to any one of claims 1 to 5, characterized in that: The steps include: Step (1) various raw materials are poured into a blender according to the formula of the organic outer layer, the light-converting layer, and the organic inner layer. After being evenly stirred, the raw materials are sucked into the hopper of the extruder through a suction machine, and after being sheared and heated by the barrels of each layer, they are passed through the connector of the barrels to reach the die head. The raw materials extruded from the die head are lifted up to be pulled and inflated at the same time to obtain a three-layer film; Step (2) corona-treating the inner organic layer of the three-layer film, coating it with anti-fog liquid, irradiating it under ultraviolet light, and curing it to obtain an agricultural greenhouse film with an ultraviolet-green light-to-blue-red spectrum.

7. The method for preparing the agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 6, characterized in that: The corona treatment method: 2kW·min / m 2 Corona for 5 seconds; UV irradiation method: irradiate under a UV lamp with a wavelength of 365nm and a power of 1000W for 1 minute; Curing method: cure at 45-55℃ for 10-14 hours.

8. The method for preparing the agricultural greenhouse film with ultraviolet-green light to blue-red spectrum according to claim 7, characterized in that, The preparation method of the anti-fog liquid comprises the following steps: P1: Dissolve N,N'-carbonyldiimidazole, 4,4'-diaminobenzophenone and triethylamine in dimethyl sulfoxide, stir at room temperature to react, and obtain a mixed solution; P2: The mixed solution was added to dimethyl sulfoxide containing polyvinyl alcohol (PVA), stirred for reaction, precipitated with anhydrous acetone at room temperature, and dried to obtain grafted PVA; P3: dissolving grafted PVA, 5-sulfosalicylic acid dihydrate and ammonium persulfate in water and stirring to obtain an anti-fog liquid.

9. The method for preparing the agricultural greenhouse film with ultraviolet-green light converted to blue-red spectrum according to claim 8, characterized in that: In the P1, the amount ratio of N,N'-carbonyldiimidazole, 4,4'-diaminobenzophenone, triethylamine, and dimethyl sulfoxide is 7.3-14.6 g:8.9-18 g:4.5-9 g:200-400 mL; the stirring reaction time is 2-4 h; In the P2, the usage ratio of polyvinyl alcohol (PVA) and dimethyl sulfoxide is 400-800 g:4-8 L; the stirring reaction method is: stirring the reaction at 55-65° C. in a nitrogen atmosphere for 10-14 hours; the drying method is: drying at 40-50° C. for 40-52 hours; and the grafted PVA substitution degree is 0.5-1.5%.

10. The method for preparing the agricultural greenhouse film with ultraviolet-green light converted to blue-red spectrum according to claim 8, characterized in that: In the P3, the usage ratio of grafted PVA, 5-sulfosalicylic acid dihydrate, ammonium persulfate, and water is 100-200 g: 9-18 g: 7-14 g: 1.1-2.2 L; stirring treatment method: stirring treatment at 85-95° C. for 3-5 hours.

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