CN115119672A - A kind of insect-proof and ventilation mulching film and preparation method thereof - Google Patents

Abstract

The invention provides an insect-proof ventilation mulching film and a preparation method thereof, wherein the mulching film is sequentially provided with a surface film layer and an insect-proof ventilation layer from top to bottom, the surface film layer is distributed with air holes, the insect-proof ventilation layer can have a temperature-adjusting ventilation effect and an insect-proof function, the insect-proof ventilation layer is composed of a garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material, and the negative heat material is beta-eucryptite loaded with benzoyl peroxide. The prepared mulching film can improve the concentration of carbon dioxide gas in the mulching film covering space through ventilation, so that the photosynthesis of crops is improved, and meanwhile, the mulching film can effectively improve the performance of the pakchoi against the invasion of the cabbage moths and insects, and is beneficial to the growth and development of the crops.

Description

A kind of insect-proof and ventilation mulching film and preparation method thereof

Technical field:

The invention belongs to the technical field of agricultural mulch, in particular to an insect-proof and ventilation mulch.

Background technique:

Green vegetables are indispensable in the daily diet of the Chinese people. To obtain a good harvest of green vegetables in agricultural production, it is necessary to ensure the requirements of soil temperature and humidity during the planting process of vegetables. The main purpose of plastic film material is to increase the temperature and humidity of the soil by covering the surface of agricultural soil with film material, so as to obtain high yield of green vegetables in cold climates. Plastic film has become an indispensable auxiliary production in China's agricultural production. Material. In addition to higher requirements for soil temperature and humidity, the growth of green vegetables also needs to consider the photosynthesis of green vegetables and prevent the occurrence of pests and diseases. The photosynthesis of green vegetables means that the vegetables must inhale the CO ₂ gas in the environment, and then convert the CO ₂ molecules into the nutrients required for the growth of crops. The CO ₂ gas concentration in the closed environment will continue to decrease. When the CO ₂ concentration in the closed environment is lower than 300ppm, the photosynthesis of crops will be inhibited, causing problems such as slow growth of vegetables, flower drop, fruit drop, and yield reduction. In addition, it is also necessary to consider the problems of diseases and insect pests of green vegetables during the planting process, because after the temperature and humidity of agricultural soil covered by plastic film are increased, although this is conducive to improving the growth and development of green vegetables, it is also conducive to the growth and development of green vegetables. The breeding of pests, pests often feed on the leaves of vegetables, which can easily damage the growth of green vegetables. The traditional mulch film currently used is mostly plastic mulch made of polyethylene or polyvinyl chloride. When using, the whole piece of plastic mulch is laid on the soil surface, that is, the mulch laying operation is completed. This kind of mulch operation is very simple and convenient, but because these traditional plastic mulches are airtight, the space covered by the traditional plastic mulch forms a closed environment, which results in that the gas in the space covered by the traditional mulch cannot communicate with the outside world rich in CO ₂ . Fresh air is exchanged. At the same time, this traditional plastic mulch has a single function. If pests and diseases occur in the farmland soil, it is necessary to break a hole in this traditional plastic mulch (sometimes it is necessary to lift the mulch as a whole), and then apply an inhibitor that can inhibit harmful bacteria in the soil. Or pesticides for the growth of pests, etc. However, it is difficult for the mulch film after the hole to impede the outward diffusion of water and heat in the soil, which seriously weakens the heat preservation and water retention effect of the mulch film on the soil, which is not conducive to increasing agricultural production and income. Therefore, on the basis of traditional mulch film, it is of great significance to develop mulch products that do not need to break holes in the mulch to remove insects, but also have certain functions of ventilation and pest resistance.

Invention content:

In order to solve the problems existing in the prior art, the present invention provides an insect-proof and ventilation mulch film and a preparation method thereof.

An insect-proof and ventilation mulch film, characterized in that, a mask layer (1) and an insect-proof ventilation layer (2) are arranged in sequence from top to bottom in the mulch film, the mask layer is distributed with ventilation holes (11), and the The anti-insect ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material, and the negative heat material (21) is benzoyl peroxide-loaded β- Eucryptite, the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material includes the following components in parts by weight: 10-30 parts of garlic extract, 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, 1-5 parts of chlorosulfonated polyethylene, 20-40 parts of polyvinyl alcohol, 4-12 parts of negative heat material; preparation of insect-proof and ventilation mulch film Proceed as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 100-32 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.1-0.12% of the total weight of the β-eucryptite negative thermal material of benzoyl peroxide;

(2) in a container, dissolve 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of Obtain solution C in ionized water; then add 10-30 parts by weight of garlic extract, 2.9-3.2 parts by weight of sodium dodecyl sulfonate, 3.9-4.3 parts by weight of OP-10 emulsifier, 20-40 parts by weight The polyvinyl alcohol in parts by weight and the deionized water in 107-258 parts by weight are stirred for 30min at room temperature between 350-360r/min to obtain emulsion D;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, and then 4-12 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1). Add to emulsion D, add 15-30 parts by weight of hydroxypropyl acrylate dropwise to emulsion D under stirring, the dripping speed is 1 drop every 2 seconds, and the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise , the solution C obtained in step (2) is also added dropwise to the emulsion D, and the dripping speed is 1 drop per 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) Coating the emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.18-0.5mm, and drying at room temperature to obtain the garlic extract-hydroxypropyl acrylate attached to the surface of the mask layer -An insect-proof ventilation layer composed of styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilation mulch can be obtained.

Wherein, the material of the mask layer is polyethylene or polyvinyl chloride, the aperture size of the air holes distributed in the mask layer is 0.5-3mm, and the distribution density of the air holes is 5-20/m ² .

The present invention is different from the prior art in that the present invention has achieved the following technical effects:

The test results of the effect examples show that the mulch film prepared by the present invention has the effect of increasing the concentration of carbon dioxide gas in the space covered by the mulch film, improving the photosynthesis of crops, and at the same time, the mulch film can effectively improve the effect of the cabbage against the diamondback moth. This is because of the following factors:

1. In the present invention, the anti-insect ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material, and the negative heat material is a benzoyl peroxide-loaded material. β-eucryptite, a negative thermal material is a material whose volume shrinks when heated and expands when cooled, while β-eucryptite is a negative thermal expansion material with excellent performance, which can be used at room temperature and low temperature. Negative thermal expansion behavior is triggered under low temperature (see document 1: Schulz H., Thermalexpansion of beta eucryptite, Journal of The American Ceramic Society, 1974, 57(7), 313-318.). Therefore, when the temperature is high in the daytime, the volume of this β-eucryptite negative heat material will shrink accordingly, so that the negative heat material particles are related to garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol The polymer matrix of the copolymer produces a certain detachment, which leads to the formation of pores on the insect-proof ventilation layer. This pore can allow the air with higher temperature during the day to be exchanged to the space covered by the mulch, and then supplement the CO ₂ in the outside air to the mulch. Space. At night, when there is no sunlight, the temperature of the environment drops, and the volume of the negative heat material particles will expand as the ambient temperature drops, and the pores between the negative heat material particles and the polymer matrix become smaller (or closed), making the night It is difficult for cold air to be exchanged into the space covered by plastic film, so the plastic film maintains the temperature of the covered soil, which in turn protects the crops covered by plastic film from being harmed by the cold air at night.

2. The negative heat material in the anti-insect ventilation layer is β-eucryptite loaded with benzoyl peroxide. Benzoyl peroxide can cause free radical polymerization of organic monomers with double bonds, so benzoyl peroxide is loaded. The β-eucryptite of formyl can cause the hydroxypropyl acrylate and styrene monomer in the system of the present invention to polymerize on the surface of the negative heat material particles to form a layer of strong and dense polymer shell wrapped in the negative heat material. The particle surface, which is conducive to the formation of temperature-controllable pores in the insect-proof ventilation layer (this will be further explained in the analysis of the working principle of the mulch film of the present invention later).

3. Hydroxypropyl acrylate and styrene in garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer can promote the formation of the emulsion of the present invention, and make the copolymer have good composition. Membrane properties, chlorosulfonated polyethylene has the effect of improving the flexibility of the formed film. In addition, chlorosulfonated polyethylene can be well dissolved in styrene. When styrene monomer undergoes a copolymerization reaction, styrene can Chlorosulfonated polyethylene has better compatibility with other components in the copolymer, and the molecular chains of chlorosulfonated polyethylene and other polymer chains in the copolymer are intertwined with each other at the molecular level to form various groups. A copolymer with a more uniform distribution.

4. In addition to the double bond and ester bond, the hydroxypropyl acrylate monomer structure in garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer has a hydrophilic structure. Hydroxyl, the composition of the copolymer also includes a strong hydrophilic polyvinyl alcohol component. The two components of hydroxypropyl acrylate and polyvinyl alcohol in the insect-proof ventilation layer can give the insect-proof ventilation layer excellent hydrophilicity. , so the contact angle of water droplets on the surface of the insect-proof ventilation layer is small, so that the condensed water droplets spread out quickly on the surface of the insect-proof ventilation layer and flow away. Since no (or less) water droplets are formed on the surface of the insect-proof and ventilation layer of the mulch film of the present invention, the sunlight can easily pass through the mulch film of the present invention and directly hit the soil surface covered by the mulch film, and at the same time, the absorption of solar energy by the water droplets is also reduced. This is beneficial for the insect-proof and ventilating plastic film of the present invention to efficiently utilize solar energy and maintain a higher temperature of the soil covered by the plastic film. At the same time, since no (or less) water droplets are formed on the surface of the insect-proof and ventilation layer of the mulch film of the present invention, the surface of the insect-proof and ventilation layer can be in direct contact with the growing environment of crops under the mulch film, and the insect-proof and ventilation layer can be more effective in inhibiting insect pests. Effect.

5. The garlic extract in the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is made from the garlic bulb of the Liliaceae plant, which is extracted by heating, concentrated under reduced pressure, and spray-dried. The water-soluble powdered product made from garlic extract maintains the original active ingredients of the plant, and is easy to dissolve in water and store. Literature ([2] Dougoud J, Toepfer S, Bateman M, et al. Efficacy of homemade botanicalinsecticides based on traditional knowledge. A review [J]. Agronomy for Sustainable Development, 2019, 39, 37; [3] Prowse G M, Galloway T S , AndrewF.Insecticidal activity of garlic juice in two dipteran pests[J].Agriculturaland Forest Entomology,2006,8,1-6;[4]Wang Yunfan, Wang Gang.Preliminary study on the control of cabbage black spot with garlic extract[J]. Journal of Chongqing University of Science and Technology (Natural Science Edition), 2008, 10(5), 61-63.) mentioned that garlic extract can be used as a natural plant-derived pesticide in agricultural production. However, it should be noted that garlic extract itself does not have film-forming properties, and its use alone cannot cover the soil surface as effectively as a film, and cannot effectively improve the temperature and humidity of the soil. At the same time, the garlic extract itself does not have good adhesion, and it cannot be used alone to stably adhere to polyethylene or polyvinyl chloride plastic films to form an effective insect-proof and ventilation layer.

6. There are ventilation holes in the mask layer, and the fresh air rich in CO ₂ from the outside can enter the lower insect-proof ventilation layer through these ventilation holes, and then enter the space covered by the plastic film.

Document 5 (CN112806199A) reports a breathable non-droplet mulch film. The mulch film is provided with a mask layer, a temperature-adjustable ventilation layer and a hydrophilic layer in sequence from top to bottom. The carbon dioxide gas concentration and the effect of reducing the ammonia gas concentration, and there is no obvious water drop formation on the inner surface of the mulch film, which can maintain a higher soil temperature. However, the mulch film described in Document 5 can only ventilate, but has no insect-proof function. Compared with the mulch film in Document 5, the mulch film of the present invention can not only ventilate, but also prevent insect damage, which is more beneficial to agricultural production.

An analysis of the working principle of the insect-proof and ventilating mulch film prepared by the present invention is as follows:

In the preparation step (1) of the present invention, the β-eucryptite particles are placed in a toluene solution containing benzoyl peroxide, and the benzoyl peroxide molecules in the solution will be adsorbed on the surface of the β-eucryptite particles, thereby Form the negative heat material of β-eucryptite loaded with benzoyl peroxide, wherein the weight of adsorbed benzoyl peroxide can account for 0.1 of the total weight of the β-eucryptite negative heat material loaded with benzoyl peroxide -0.12%; compared with β-eucryptite without benzoyl peroxide, the β-eucryptite negative thermal material particles loaded with benzoyl peroxide can induce hydroxypropyl acrylate and styrene monomer molecules in the The polymerization reaction occurs on the surface of the negative heat material particles, so that the polymer shell formed on the surface of the negative heat material particles is a dense structure, not a soft structure. The polymer shell of this dense structure has good rigidity and small deformation. When the ambient temperature increases during the day, the negative heat material shrinks. Since the dense polymer shell wrapping the negative heat material particles is rigid and not easy to deform, it will not shrink with the shrinkage of the negative heat material, which will cause the negative heat material particles to shrink. A gap is formed between the surface and the dense polymer shell, thereby opening the exchange channel of indoor and outdoor gases. When the ambient temperature decreases at night, the particles of the negative heat material expand to the surrounding polymer shell, thus closing the gap between the negative heat material and the polymer shell, that is, closing the exchange channel of indoor and outdoor gas. Cold air will also not be able to enter the space covered by the mulch.

Steps (2)-(4) in the preparation steps are the reaction steps for preparing the composite negative heat material emulsion containing garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer. In the step, chlorosulfonated polyethylene is first dissolved in styrene, because the solubility of chlorosulfonated polyethylene in styrene is very good, so that the chlorosulfonated polyethylene is not easy to form particles or agglomerates in the emulsion, and the chlorosulfonated polyethylene is not easy to form particles or agglomerates. The molecular form crosses and interpenetrates with other polymer chains to form a polymer copolymer with uniform distribution of components. In steps (2)-(4), the ammonium persulfate initiator can initiate polymerization of hydroxypropyl acrylate and styrene monomer molecules with double bonds in the solution; sodium dodecyl sulfonate and OP-10 (a chemical raw material, alkylphenol polyoxyethylene ether obtained by the condensation reaction of alkylphenol and ethylene oxide, which is a type of emulsifier OP series) acts as an emulsifier, which can generate The copolymers form small oil-in-water particles suspended in solution to form emulsions.

The preparation step (5) is to coat the composite negative heat material emulsion containing garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer on the polyethylene or polyvinyl chloride mask layer, wherein The chlorosulfonated polyethylene has good adhesion to polyethylene or polyvinyl chloride, which makes the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material emulsion very easy Attached to the mask layer, after the water in the emulsion evaporates, a layer of composite negative heat material containing garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer will be formed on the mask layer The solid coating of the solid coating can switch the ventilation channel with the change of temperature. The evenly distributed garlic extract components in the solid coating can play the effect of reducing the damage degree of pests to crops, so the solid coating also plays the role of preventing pests. The hydroxypropyl acrylate and polyvinyl alcohol components in the solid coating make the coating have good hydrophilicity, so that water droplets can spread on the surface of the solid coating and flow away quickly, so that the surface of the anti-insect ventilation layer has no water droplets. In this way, the surface of the insect-proof and ventilation layer can directly contact the growing environment of crops under the mulch film without the barrier of the water droplet layer, so that the insect-proof and ventilation layer of the present invention can exert a greater efficiency of inhibiting insect pests.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention.

FIG. 1 is a three-dimensional structural diagram of an insect-proof and ventilating mulch film of the present invention.

Fig. 2 is a cross-sectional view of an insect-proof and ventilating mulch film of the present invention.

Labels in the figure: 1-Mask layer; 2-Anti-insect ventilation layer; 11-Ventilation hole; 21-Negative heat material.

Detailed ways

The above and other technical features and advantages of the present invention will be described in more detail below with reference to the embodiments. The chemical raw materials used in the following examples are commercially available, chemically pure reagents;

The β-eucryptite powder was provided by Zibo Chendong New Materials Co., Ltd., and particles with different mesh numbers were screened out after sieving and used in the following examples.

Chlorosulfonated polyethylene (model: CSM3304, production unit: Jilin Petrochemical Branch) was purchased from Shanghai Jinju International Trade Co., Ltd.

Polyvinyl alcohol (model: 1788) was purchased from Shanghai Chenqi Chemical Technology Co., Ltd.

Example 1

Referring to the accompanying drawings, an insect-proof and ventilation mulch film is characterized in that, the mulch film is provided with a mask layer (1) and an insect-proof ventilation layer (2) in sequence from top to bottom, and the mask layer is made of polyvinyl chloride, and the mask layer is made of polyvinyl chloride. The pore size of the ventilation holes (11) distributed in the layer is 0.5mm, the distribution density of the ventilation holes is 5/m ² , and the insect-proof ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated The polyvinyl-polyvinyl alcohol copolymer composite negative heat material is composed, the negative heat material (21) is β-eucryptite loaded with benzoyl peroxide, the garlic extract-hydroxypropyl acrylate-styrene-chlorine The sulfonated polyethylene-polyvinyl alcohol copolymer composite negative heating material includes the following components in parts by weight: 10 parts of garlic extract, 15 parts of hydroxypropyl acrylate, 1 part of styrene, 1 part of chlorosulfonated polyethylene, and 1 part of polyethylene 20 parts of alcohol, 4 parts of negative heat material; the preparation steps of an insect-proof and ventilation mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 100-80 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.1% of the total weight of the β-eucryptite negative thermal material of benzoyl peroxide;

(2) In a container, dissolve 1 part by weight of chlorosulfonated polyethylene in 1 part by weight of styrene to obtain solution B; dissolve 0.65 part by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 10 parts by weight of garlic extract, 2.9 parts by weight of sodium dodecyl sulfonate, 3.9 parts by weight of OP-10 emulsifier, 20 parts by weight of polyvinyl alcohol, 107 parts by weight of Ionized water, at a rotating speed of 350 r/min and stirring at room temperature for 30 min, emulsion D was obtained;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, then 4 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 15 parts by weight of hydroxypropyl acrylate was added dropwise into the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) The emulsion E obtained in step (4) is coated on the surface of the mask layer, the thickness of the emulsion E layer is controlled to be 0.18 mm, and after drying at room temperature, the garlic extract-hydroxypropyl acrylate-benzene which is attached to the surface of the mask layer is obtained Insect-proof ventilation layer composed of ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilating mulch film of Example 1 can be obtained.

Example 2

Referring to the accompanying drawings, an insect-proof and ventilation mulch film is characterized in that, the mulch film is provided with a mask layer (1) and an insect-proof ventilation layer (2) in sequence from top to bottom, and the mask layer is made of polyethylene, and the mask layer is made of polyethylene. The pore size of the ventilation holes (11) is 1 mm, the distribution density of the ventilation holes is 9 pieces/m ² , and the insect-proof ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene -Polyvinyl alcohol copolymer composite negative heating material, the negative heating material (21) is β-eucryptite loaded with benzoyl peroxide, the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated The polyethylene-polyvinyl alcohol copolymer composite negative heat material includes the following components in parts by weight: 15 parts of garlic extract, 19 parts of hydroxypropyl acrylate, 2 parts of styrene, 2 parts of chlorosulfonated polyethylene, and 25 parts of polyvinyl alcohol parts, 6 parts of negative heat material; the preparation steps of a kind of insect-proof and ventilation mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 80-65 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.11% of the total weight of the β-eucryptite negative heat material of benzoyl peroxide;

(2) Dissolve 2 parts by weight of chlorosulfonated polyethylene in 2 parts by weight of styrene in a container to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 15 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4 parts by weight of OP-10 emulsifier, 25 parts by weight of polyvinyl alcohol, 144 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

(3) the container filled with emulsion D is heated to 82° C. in a water bath, then 6 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 19 parts by weight of hydroxypropyl acrylate was added dropwise into the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) The emulsion E obtained in step (4) is coated on the surface of the mask layer, the thickness of the emulsion E layer is controlled to be 0.21 mm, and after drying at room temperature, the garlic extract-hydroxypropyl acrylate-benzene, which is attached to the surface of the mask layer, is obtained Insect-proof ventilation layer composed of ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilating mulch film of Example 2 can be obtained.

Example 3

Referring to the accompanying drawings, an insect-proof and ventilation mulch film is characterized in that, the mulch film is provided with a mask layer (1) and an insect-proof ventilation layer (2) in sequence from top to bottom, and the mask layer is made of polyethylene, and the mask layer is made of polyethylene. The pore size of the ventilation holes (11) is 2mm, the distribution density of the ventilation holes is 13/m ² , and the insect-proof ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene -Polyvinyl alcohol copolymer composite negative heating material, the negative heating material (21) is β-eucryptite loaded with benzoyl peroxide, the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated The polyvinyl-polyvinyl alcohol copolymer composite negative heat material includes the following components in parts by weight: 20 parts of garlic extract, 23 parts of hydroxypropyl acrylate, 3 parts of styrene, 3 parts of chlorosulfonated polyethylene, and 30 parts of polyvinyl alcohol parts, 8 parts of negative heat material; the preparation steps of a kind of insect-proof and ventilation mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 65-60 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.11% of the total weight of the β-eucryptite negative heat material of benzoyl peroxide;

(2) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 20 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, then 8 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 23 parts by weight of hydroxypropyl acrylate was added dropwise to the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) The emulsion E obtained in step (4) is coated on the surface of the mask layer, the thickness of the emulsion E layer is controlled to be 0.25 mm, and after drying at room temperature, the garlic extract-hydroxypropyl acrylate-benzene which is attached to the surface of the mask layer is obtained Insect-proof ventilation layer composed of ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilating mulch film of Example 3 can be obtained.

Example 4

Referring to the accompanying drawings, an insect-proof and ventilation mulch film is characterized in that, the mulch film is provided with a mask layer (1) and an insect-proof ventilation layer (2) in sequence from top to bottom, and the mask layer is made of polyvinyl chloride, and the mask layer is made of polyvinyl chloride. The pore size of the ventilation holes (11) distributed in the layer is 2.5mm, the distribution density of the ventilation holes is 17/m ² , and the insect-proof ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated The polyvinyl-polyvinyl alcohol copolymer composite negative heat material is composed, the negative heat material (21) is β-eucryptite loaded with benzoyl peroxide, the garlic extract-hydroxypropyl acrylate-styrene-chlorine The sulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material includes the following components in parts by weight: 25 parts of garlic extract, 27 parts of hydroxypropyl acrylate, 4 parts of styrene, 4 parts of chlorosulfonated polyethylene, polyethylene 35 parts of alcohol, 10 parts of negative heat material; the preparation steps of an insect-proof and ventilation mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 60-48 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.12% of the total weight of the β-eucryptite negative thermal material of benzoyl peroxide;

(2) in a container, dissolve 4 parts by weight of chlorosulfonated polyethylene in 4 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 25 parts by weight of garlic extract, 3.1 parts by weight of sodium dodecyl sulfonate, 4.2 parts by weight of OP-10 emulsifier, 35 parts by weight of polyvinyl alcohol, 218 parts by weight of Ionized water, the emulsion D was obtained after stirring for 30min at a rotating speed of 360r/min and room temperature;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, then 10 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 27 parts by weight of hydroxypropyl acrylate was added dropwise into the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) The emulsion E obtained in step (4) is coated on the surface of the mask layer, the thickness of the emulsion E layer is controlled to be 0.3 mm, and after drying at room temperature, the garlic extract-hydroxypropyl acrylate-benzene, which is attached to the surface of the mask layer, is obtained Insect-proof ventilation layer composed of ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilating mulch film of Example 4 can be obtained.

Example 5

Referring to the accompanying drawings, an insect-proof and ventilation mulch film is characterized in that, the mulch film is provided with a mask layer (1) and an insect-proof ventilation layer (2) in sequence from top to bottom, and the mask layer is made of polyethylene, and the mask layer is made of polyethylene. The pore size of the ventilation holes (11) is 3mm, the distribution density of the ventilation holes is 20/m ² , and the insect-proof ventilation layer is composed of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene -Polyvinyl alcohol copolymer composite negative heating material, the negative heating material (21) is β-eucryptite loaded with benzoyl peroxide, the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated The polyethylene-polyvinyl alcohol copolymer composite negative heat material includes the following components in parts by weight: 30 parts of garlic extract, 30 parts of hydroxypropyl acrylate, 5 parts of styrene, 5 parts of chlorosulfonated polyethylene, and 40 parts of polyvinyl alcohol parts, 12 parts of negative heat material; the preparation steps of a kind of insect-proof and ventilation mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 48-32 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.12% of the total weight of the β-eucryptite negative thermal material of benzoyl peroxide;

(2) 5 parts by weight of chlorosulfonated polyethylene is dissolved in 5 parts by weight of styrene in a container to obtain solution B; 0.65 parts by weight of ammonium persulfate initiator is dissolved in 10 parts by weight of deionized water to obtain a solution C; then add 30 parts by weight of garlic extract, 3.2 parts by weight of sodium dodecyl sulfonate, 4.3 parts by weight of OP-10 emulsifier, 40 parts by weight of polyvinyl alcohol, 258 parts by weight of Ionized water, the emulsion D was obtained after stirring for 30min at a rotating speed of 360r/min and room temperature;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, then 12 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 30 parts by weight of hydroxypropyl acrylate was added dropwise to the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of hydroxypropyl acrylate and solution C in the step (3), the reaction system is heated to 85 ° C, and the constant temperature stirring reaction is performed for 5 h at this temperature, and the stirring speed is 250 r/min; when the constant temperature stirring reaction ends Then, the obtained mixed solution is lowered to room temperature, and then concentrated ammonia water is added to adjust the pH of the mixed solution to neutrality to obtain emulsion E;

(5) The emulsion E obtained in step (4) is coated on the surface of the mask layer, the thickness of the emulsion E layer is controlled to be 0.5 mm, and after drying at room temperature, the garlic extract-hydroxypropyl acrylate-benzene which is attached to the surface of the mask layer is obtained Insect-proof ventilation layer composed of ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material;

Through steps (1)-(5), an insect-proof and ventilation mulch film of Example 5 can be obtained.

Comparative Example 6

In this example, the mulch film is prepared according to the steps described in Example 3. The difference between this example and Example 3 is that there is no negative heat material in the insect-proof ventilation layer. Density), component composition and component content, and related preparation steps are the same as in Example 3. The preparation steps of this embodiment are as follows:

(1) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 20 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

(2) the container filled with emulsion D is heated to 82°C in a water bath, and then 23 parts by weight of hydroxypropyl acrylate is added dropwise to emulsion D under stirring, and the dripping speed is 1 drop every 2 seconds, and the stirring speed is 250r /min; while adding hydroxypropyl acrylate dropwise, the solution C obtained in step (1) is also added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

The rest of the preparation steps are the same as the preparation steps (4) and (5) of Example 3.

Comparative Example 7

In this example, the mulch film is prepared according to the steps described in Example 3. The difference between this example and Example 3 is that the amount of garlic extract in the preparation step (2) is 9 parts by weight, which is within the range described in the claims. In addition, other aspects related to the mulching film structure, used components, component contents and related preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

The preparation step (1) in this example is the same as the step (1) in Example 3.

(2) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 9 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

The rest of the preparation steps are the same as the preparation steps (3)-(5) of Example 3.

Comparative Example 8

In this example, the mulch film is prepared according to the steps described in Example 3. The difference between this example and Example 3 is that the amount of garlic extract in the preparation step (2) is 31 parts by weight, which is within the range described in the claims. In addition, other aspects related to the mulching film structure, used components, component contents and related preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

The preparation step (1) in this example is the same as the step (1) in Example 3.

(2) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 31 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

The rest of the preparation steps are the same as the preparation steps (3)-(5) of Example 3.

Experimental phenomenon: During the preparation process of Comparative Example 8, the emulsion E in step 4 had a phenomenon of demulsification and stratification.

Comparative Example 9

In this example, the mulch film is prepared according to the steps in Example 3. The difference between this example and Example 3 is that the amount of hydroxypropyl acrylate in the preparation step (3) is 14 parts by weight, which is within the scope of the claims. Other than that, the structure of the mulch film, the components used, the content of the components and the related preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

The preparation steps (1) and (2) of this example are the same as the steps (1) and (2) of Example 3;

(3) the container containing the emulsion D is heated to 82° C. in a water bath, then 8 parts by weight are taken out from the β-eucryptite negative heat material particles of the loaded benzoyl peroxide obtained in step (1) and added to In the emulsion D, 14 parts by weight of hydroxypropyl acrylate was added dropwise into the emulsion D under stirring, and the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; (2) the obtained solution C is added dropwise to the emulsion D, and the dropping rate is 1 drop every 5 seconds;

The rest of the preparation steps are the same as the preparation steps (4) and (5) of Example 3.

Experimental phenomenon: During the preparation process of Comparative Example 9, the emulsion E in step (4) had a phenomenon of demulsification and stratification.

Comparative Example 10

In this example, the mulch film is prepared according to the steps described in Example 3. The difference between this example and Example 3 is that the amount of styrene in the preparation step (2) is 0.8 parts by weight, and the amount of chlorosulfonated polyethylene is 0.8 parts by weight. The amounts of both are outside the scope described in the claims, and other aspects related to the mulching film structure, the components used, the content of the components and the relevant preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

The preparation step (1) of this embodiment is the same as the step (1) of Example 3;

(2) In a container, 0.8 parts by weight of chlorosulfonated polyethylene is dissolved in 0.8 parts by weight of styrene to obtain solution B; 0.65 parts by weight of ammonium persulfate initiator is dissolved in 10 parts by weight of deionized water to obtain a solution C; then add 20 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

The rest of the preparation steps are the same as the preparation steps (3)-(5) of Example 3.

Comparative Example 11

In this example, the mulch film is prepared according to the steps in Example 3. The difference between this example and Example 3 is that the amount of polyvinyl alcohol used in the preparation step (2) is 19 parts by weight, which is within the range described in the claims. In addition, other aspects related to the mulching film structure, used components, component contents and related preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

The preparation step (1) of this embodiment is the same as the step (1) of Example 3;

(2) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 20 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 19 parts by weight of polyvinyl alcohol, 181 parts by weight of Ionized water, at a rotating speed of 355r/min and stirring at room temperature for 30min, emulsion D was obtained;

The rest of the preparation steps are the same as the preparation steps (3)-(5) of Example 3.

Comparative Example 12

In this example, the mulch film is prepared according to Example 3. The difference between this example and Example 3 is that the particle size of the negative heat material in the insect-proof ventilation layer is 115-400 mesh, and the particle size is within the range of the claims described in the claims. Outside the range (particle size is 100-32 mesh), other aspects related to mulching film structure, component composition, component content and related preparation steps are the same as in Example 3. The preparation steps of this embodiment are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, then soak β-eucryptite with particle size of 115-400 mesh and 30 weight parts at 25°C In solution A for 15 hours, the soaked β-eucryptite was taken out, and air-dried at room temperature for 10 hours to obtain a benzoyl peroxide-loaded β-eucryptite negative thermal material, in which the weight of benzoyl peroxide accounted for the load 0.11% of the total weight of the β-eucryptite negative heat material of benzoyl peroxide;

The rest of the preparation steps are the same as the preparation steps (2)-(5) of Example 3.

Comparative Example 13

This example is to prepare mulch according to the steps described in Example 3. The difference between this example and Example 3 is that the garlic extract is not added in step (2), but in step (5) and step (4) The obtained emulsion E is mechanically mixed, and the obtained mixture is smeared on the mask layer, that is, the garlic extract does not form a copolymer with hydroxypropyl acrylate monomer, etc., but is simply physically mixed with the copolymer. The preparation steps of this embodiment are as follows:

The preparation step (1) of this embodiment is the same as the step (1) of Example 3;

(2) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of deionized water, at a rotating speed of 355r /min and room temperature to obtain emulsion D after stirring for 30min;

The preparation steps (3) and (4) of the present embodiment are the same as the steps (3) and (4) of the embodiment 3;

(5) The emulsion E obtained in step (4) is physically mixed with 20 parts by weight of garlic extract at normal temperature, the obtained mixture is coated on the surface of the mask layer, the thickness of the mixture is controlled to be 0.25mm, and the present embodiment is obtained after drying at room temperature Mulch.

Experimental phenomenon: In step (5) of this example, when the emulsion E is mixed with 20 parts by weight of garlic extract, the phenomenon of demulsification and stratification occurs, and the obtained mixture is difficult to adhere to the mask layer.

Comparative Example 14

In this example, the mulch film is prepared according to the steps described in Example 3. The difference between this example and Example 3 is that the negative heat material in the insect-proof ventilation layer is β-eucryptite, not β-eucryptite loaded with benzoyl peroxide. For eucryptite, other aspects related to the structure of the mulch film, the components used and the content of the components, and the relevant preparation steps are the same as those in Example 3. The preparation steps of this embodiment are as follows:

(1) in a container, dissolve 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain solution B; dissolve 0.65 parts by weight of ammonium persulfate initiator in 10 parts by weight of deionized water to obtain a solution C; then add 20 parts by weight of garlic extract, 3 parts by weight of sodium dodecyl sulfonate, 4.1 parts by weight of OP-10 emulsifier, 30 parts by weight of polyvinyl alcohol, 181 parts by weight of The ionized water was stirred at room temperature for 30min at a rotating speed of 355r/min to obtain emulsion D;

(2) the container containing emulsion D is heated to 82° C. in a water bath, then the β-eucryptite negative heat material particles of 65-60 mesh and 8 parts by weight are added to the emulsion D, and 23 wt. Part of hydroxypropyl acrylate is added dropwise to emulsion D, the dripping speed is 1 drop every 2 seconds, and the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution C obtained in step (2) is also added dropwise to the emulsion In D, the dripping rate is 1 drop every 5 seconds;

The remaining steps of this embodiment are the same as steps (4) and (5) of Embodiment 3.

Application Example 15

In this example, the mulch films obtained in Example 1, Example 3, Example 5, and Comparative Examples 6-14 are covered on the soil surface, and the specific test steps are as follows:

Select a vegetable planting field, the location is east longitude: 118.97539027571867° and north latitude: 32.066403113172214°, and plant pakchoi in this field; in November 2020, take Example 1, Example 3, Example 5, and Comparative Example 6- 14. For the mulch film prepared in each example, cut out a size of 0.6m × 0.6m on the mulch film of each example, and cover each piece of cut mulch film on the soil with a size of 0.3m × 0.3m in each field. 0.1m, 30 cabbage seeds were evenly sown in each field, the surface of the plastic film insect-proof and ventilation layer was facing the soil, the height of the plastic film was about 10 cm above the ground, and the edge of each plastic film was buried in the ground at the edge of each field. 2cm, and compacted with soil blocks to ensure that the space surrounded by each mulch film is a closed space.

Effect Example

In this example, the following performance tests are carried out on the various films in Example 15 (including the mulching films obtained in Examples 1, 3, 5 and Comparative Examples 6-14).

1. Soil temperature test test covered by plastic film

Using GPRS type soil temperature and humidity sensor (model: JXBS-7001-TR, supplier: Jingxun Changtong Electronic Technology Co., Ltd., the sensor relies on mobile phone signal network for soil temperature and humidity data transmission) to automatically measure and upload the soil covered by plastic film Average temperature at a depth of 5cm. The measurement period is 3 consecutive days from November 7 to 9, 2020. The measurement time is 12:00 during the day and 2:00 at night. The average soil temperature = (the sum of soil temperatures at a certain time point in 3 days)/3 . The average ambient temperature outside the plastic film at 12:00 during the day is 16.7°C, and the average ambient temperature outside the plastic film at 2:00 at night is 6.8°C.

2. Test and test of CO ₂ gas exchange performance of plastic film

Using GPRS type carbon dioxide sensor (model: JXBS-7001-CO2, supplier: Jingxun Changtong Electronic Technology Co., Ltd., the sensor relies on the mobile phone signal network for CO ₂ concentration data transmission in the gas) to automatically measure and upload the CO ₂ in the space covered by mulch film. Average concentration of gas. The measurement period is 3 consecutive days from November 7 to 9, 2020. The measurement time is 12:00 during the day and 2:00 at night. The average concentration of CO ₂ = (the sum of the concentration of CO ₂ at a certain time point in 3 days) /3. , the average concentration of _CO2 gas in the environment outside the mulch is 400ppm.

3. Film hydrophilicity test

(1) Water drop test on mulch film: Select a piece of mulch film with an area of 0.1m×0.1m, and count the average number of water droplets with a diameter greater than 2mm in this area. The measurement time period is 3 consecutive days from November 7 to 9, 2020. The measurement time is 12:00 during the day every day. The average number of water droplets = (the sum of the number of water droplets in 3 days)/3.

(2) Contact angle test on the side of the mulch film facing the soil: turn on the power of the DSA100 optical contact angle measuring instrument, then cut 3 film samples of the same size from the mulch film obtained in each example, and measure the orientation of the 3 film samples. Fix the soil side up on the workbench, put 0.01ml of distilled water on the needle to form water droplets, and drop them on the surface of the film sample. When the water droplets sit on the film sample for 50s, turn the cross in the eyepiece to make the water droplet and the film. The tangent at the contact point of the sample, the angle between the tangent and the horizontal plane of the film sample is the contact angle. The contact angles were measured at 3 different locations and the average value was taken as the contact angle of the soil-facing side of the membrane sample.

4. The insect resistance test was carried out in a greenhouse environment (25° C., 35% humidity), and expressed as the rate of leaf damage to the leaves of the cabbage by the diamondback moth. The diamondback moths were collected from the farm. The collected diamondback moths were first raised with fresh cabbage for two days to eliminate the influence of the original food reserve in the larvae on subsequent experiments. Then, larvae with similar body sizes were selected and divided into several groups. Group of 10. The cabbage with similar weight and appearance was transplanted into flowerpots of the same size (each flowerpot was 10cm in diameter and 5cm in depth), and each flowerpot was filled with 450g of soil powder obtained through a 5-mesh sieve, each flowerpot 4 pakchoi were transplanted in the middle, and then each group of larvae was placed on the pak choi leaf surface in each flowerpot, and then the plastic films corresponding to Examples 1, 3, 5 and Comparative Examples 6-14 were covered on the pak choi Above, the distance between the top of the mulch film and the highest point of the cabbage leaf surface is 3cm, the edge of the mulch film is closed at the edge of the top of the flowerpot, and is properly tied with a rope, this is to prevent the diamondback moth from getting between the cabbages in different flowerpots move and affect the experimental results. After the third day, YMJ-A leaf surface measuring instrument was used to measure the damage of pakchoi leaves. Leaf damage rate=(total area of damaged leaves/total area of original leaves)×100%.

5. It can be seen from the results in Table 1 that the soil surface of Examples 1, 3 and 5 is covered with plastic film, and their corresponding soil temperature can be maintained at 15.8-16.6 °C at 12:00 during the day. This temperature range is consistent with the daytime environment. The temperature is similar; the soil temperature can be maintained at 14.8-15.2°C at 2 o'clock at night, which can be about 8°C higher than the ambient temperature. This is because the ventilation pores of the plastic film are open during the day, and the hot air in the external environment enters the plastic film space during the day, and the hot air can heat the soil temperature covered by the plastic film to a similar degree to the ambient temperature. The ventilation pores are closed, and the cold air at night cannot enter the space covered by plastic film, which makes the temperature of the soil covered by plastic film not drop too fast. Therefore, the temperature of the soil covered by plastic film at night in Examples 1, 3, and 5 can be much higher than the external environment. temperature. Examples 1, 3, and 5 The space covered by plastic film has a CO2 concentration range of 371-396ppm at 12:00 during the day, and a _CO2 concentration range of 963-998ppm at _2:00 at night. The _CO2 concentration in the plastic film-covered space at night is higher than that during the day The reason for the high concentration of CO ₂ is that crops are mainly photosynthesis under the action of sunlight during the day and will absorb CO ₂ , and crops are mainly respiration at night, and a large amount of CO ₂ will be exhaled at night. Although the CO ₂ concentration of the mulching space in Examples 1, 3 and 5 became lower during the day, the CO ₂ concentration was still higher than the 300ppm required for photosynthesis, which was sufficient to maintain the normal photosynthesis of crops. This is because the ventilation holes on the mulch films of Examples 1, 3, and 5 are open during the day, and CO ₂ in the outside atmosphere can be supplemented into the space covered by the mulch film, so that the concentration of CO ₂ in the space covered by the mulch film will not drop to excessive levels. Low. The contact angles (8-10°) of the insect-proof and ventilation layers of the mulch films of Examples 1, 3, and 5 are all relatively small, indicating that the insect-proof and ventilation layers of the mulch films of Examples 1, 3, and 5 have excellent hydrophilicity, and the water droplets in such The hydrophilic anti-insect ventilation layer will spread without forming too many water droplets. The results in Table 1 show that no obvious water droplets are found on the surface of the mulch films of Examples 1, 3, and 5, indicating that the insect-proof and ventilation layers of the mulch films of the above examples have produced The effect of not easily forming water droplets. In the anti-insect experiment, the leaf damage rate (4-6%) of the plastic films of Examples 1, 3, and 5 was lower, because the garlic extract was evenly distributed in the insect-proof and ventilation layers of the plastic films of Examples 1, 3, and 5. , and there is no obvious water drop layer covering the insect-proof and ventilation layer, so that the insect-proof and ventilation layer can directly contact the growth environment of pakchoi under the mulch film, which can play a better insect-proof effect.

As far as Comparative Example 6 is concerned, the results in Table 1 show that the CO ₂ concentration in the space covered by the mulch film of Comparative Example 6 is 107 ppm at 12:00 during the day, which is lower than the corresponding _CO The _CO2 concentration of Example 3 is 2.7 times lower, which is also far below the 300ppm required for crop photosynthesis. The difference between Comparative Example 6 and Examples 1, 3, and 5 is that there is no negative heat material in the insect-proof ventilation layer, so the mulch film prepared in Comparative Example 6 does not have the performance of ventilation with temperature changes, which will lead to Comparative Example 6 The mulch film cannot replenish _CO2 from the outside fresh air into the mulch film space in time during the day.

As far as Comparative Example 7 is concerned, the results in Table 1 show that the damage rate (33%) of the pak choi leaves under the mulch film is much higher than that of the pak choi leaves of Examples 1, 3, and 5, which is the damage of the leaves of Example 3. 8.25 times the rate (4%), this is because the amount of garlic extract in Comparative Example 7 is 9 parts by weight, which is lower than the range described in the claims (10-30 parts by weight of garlic extract), that is, garlic If the amount of the extract is too small, the insect-proof effect of the mulch film of the present invention will be affected.

As far as the mulch film of Comparative Example 8 is concerned, in step 4 of Comparative Example 8, the emulsion E demulsification and stratification occurred; this is because the amount of garlic extract in Comparative Example 8 is 31 parts by weight, which is higher than the The range described in the requirements (10-30 parts by weight of garlic extract), garlic extract has no emulsification effect, so the excessive amount of garlic extract will cause the emulsion to be difficult to form, and then emulsion E occurs demulsification and stratification. The emulsion is coated on the mask layer, and the components in the obtained coating are also unevenly distributed, so that the properties of the mulch film of Comparative Example 8 are inferior to those of Examples 1, 3, and 5, such as , due to the failure of the regulation and ventilation function of the negative heat material in the demulsification layered coating, the carbon dioxide concentration in the space covered by the mulch film of Comparative Example 8 was 246 ppm at 12:00 during the day, which was lower than the 300 ppm required for crop photosynthesis The demulsification coating is also poor in light transmittance, and the sunlight is poor in heating the soil with the plastic film, and the soil is difficult to heat up. The leaf damage rate of pak choi (19%) is much higher than that of Examples 1, 3, and 5, and 4.75 times that of Example 3 (4%). The uneven distribution in the coating affects the insect repellency of the mulch.

As far as the mulching film of Comparative Example 9 is concerned, the consumption of hydroxypropyl acrylate in this example is 14 parts by weight, which is lower than the range described in the claims (15-30 parts by weight of hydroxypropyl acrylate), and Comparative Example 9 The demulsification and stratification phenomenon occurred in the emulsion E, that is, a small amount of hydroxypropyl acrylate will lead to the demulsification and stratification of the emulsion E, indicating that the appropriate amount of hydroxypropyl acrylate is an important factor for the formation of stable emulsion E. In the same way as Comparative Example 8, the demulsification emulsion was coated on the mask layer, and the components in the coating were also unevenly distributed, so that the properties of the film in Comparative Example 9 were the same as those in Examples 1, 3, and 5. The performance of the mulch film is relatively poor; in addition, the amount of hydroxypropyl acrylate in Comparative Example 9 is small, resulting in a large contact angle of the insect-proof and ventilation coating, low hydrophilicity, and the surface of the coating is easy to form water droplets, and the water droplets Layer evaporation will absorb solar energy, reducing the ability of sunlight to heat the soil under the mulch film, and the soil temperature increase is limited. The average temperature of the soil under the mulch film in Comparative Example 9 is 5.7-6.5 °C lower than that in Example 3; On the air layer, the insect-proof ventilation layer and the growth environment of pakchoi under the mulch film cannot be directly contacted, which further reduces the insect-proof effect of the mulch film in Comparative Example 9. The blade breakage rate is higher than that of Examples 1, 3, and 5, and is 6.75 times that of the blade breakage rate (4%) of Example 3.

As far as the mulch film of Comparative Example 10 is concerned, the results in Table 1 show that the average temperature of the soil under the mulch film of Comparative Example 10 is 4.2-4.9 °C lower than that of the mulch film of Example 3; The number of water droplets formed by the plastic film is much more than that of Examples 1, 3 and 5; the damage rate of the pak choi leaves under the plastic film (22%) is much higher than that of Examples 1, 3 and 5, which is the same as that of Example 3. The blade damage rate (4%) is 5.5 times. This is because the consumption of styrene in Comparative Example 10 is 0.8 parts by weight, and the consumption of chlorosulfonated polyethylene is 0.8 parts by weight, and the consumption of both is lower than the range described in the claims (1-5 parts by weight of styrene, 1-5 parts by weight of chlorosulfonated polyethylene) 1-5 parts by weight of polyethylene), styrene and chlorosulfonated polyethylene can improve the stability of the insect-proof ventilation layer adhering to the mask layer. In Comparative Example 10, the amount of styrene and chlorosulfonated polyethylene was too high. When the mulch film is in use, the anti-insect ventilation layer will fall off a lot, part of the hydrophobic mask layer will be exposed, and the overall hydrophilicity of the anti-insect ventilation layer will become worse, so that more water droplets will form on the anti-insect ventilation layer. , the same as the premise, thereby reducing the temperature increase of the soil and the insect-proof effect of the insect-proof ventilation layer.

As far as the mulch film of Comparative Example 11 is concerned, the results in Table 1 show that the average temperature of the soil under the mulch film of Comparative Example 11 is 2.6-3.6°C lower than that of the mulch film of Example 3; The number of water droplets formed by the mulch film is much more than that of Examples 1, 3, and 5; the contact angle of the mulch film is 85°; The rate is 5 times that of the blade breakage rate (4%) of Example 3. This is because the amount of polyvinyl alcohol in Comparative Example 11 is 19 parts by weight, which is lower than the range described in the claims (20-40 parts by weight of polyvinyl alcohol), and the amount of polyvinyl alcohol in Comparative Example 11 is small , resulting in a large contact angle of the insect-proof ventilation layer, low hydrophilicity, and the insect-proof ventilation layer is easy to form water droplets, and the evaporation of the water droplet layer will absorb solar energy, reducing the ability of sunlight to heat the soil under the mulch, and the soil temperature increase is limited. The obvious water bead layer is covered on the insect-proof and ventilation layer, so that the insect-proof ventilation layer and the growth environment of pakchoi under the mulch film cannot be in direct contact, which reduces the insect-proof effect of the mulch film of Comparative Example 11.

As far as the mulch film of Comparative Example 12 is concerned, the results in Table 1 show that the CO ₂ in the space covered by the mulch film of Comparative Example 12 is 121 ppm at 12:00 during the day, which is lower than the _CO 3 has a 2.3 times lower _CO concentration, which is well below the 300ppm required for crop photosynthesis. This is because the particle size of the negative heat material in the insect repellent ventilation layer of Comparative Example 12 is 115-400 mesh, which is lower than the range described in the claims (particle size is 100-32 mesh), which results in The negative heat material particles are too deeply buried in the insect-proof ventilation layer, and the gap between the negative heat material and the polymer matrix is also deeply buried inside the polymer matrix, while the surface of the insect-proof ventilation layer has no obvious pores, which makes it difficult to realize the membrane Effective exchange of gas inside and outside.

As far as the mulch film of Comparative Example 13 is concerned, in this example, garlic extract was not added in step (2), but was mechanically mixed with emulsion E in step (5), and the obtained mixture was smeared on the mask layer, namely garlic. The extract does not form a copolymer with hydroxypropyl acrylate monomer and the like, but is simply physically mixed with the copolymer. The experimental phenomenon of this example is that when emulsion E and 20 parts by weight of garlic extract are physically mixed, the phenomenon of demulsification and stratification occurs, and the obtained mixture is difficult to adhere to the mask layer, indicating that the garlic extract without copolymerization reaction Direct contact with the emulsion will destabilize the emulsion. In the same way as Comparative Examples 8 and 9, the demulsification emulsion was coated on the mask layer, and the components in the obtained coating were also unevenly distributed, so that the properties of the film in Comparative Example 13 were the same as those in Examples 1 and 3. The performance of the mulch film in 13 and 5 is relatively poor; the negative heat material fails to regulate the ventilation function in the demulsification coating, and the CO ₂ concentration in the space covered by the mulch film of Comparative Example 13 is 177ppm at 12:00 during the day, a low The 300ppm required for crop photosynthesis; the light transmittance of the demulsification coating is also poor, the sunlight is poor in heating the soil under the mulch film, and the soil is difficult to heat up. The average temperature of the soil under the mulch film in Comparative Example 13 is 5 lower than that in Example 3 -5.7°C; the leaf damage rate (23%) of the mulch film in Comparative Example 13 is much higher than that of Examples 1, 3, and 5, and 5.75 times that of Example 3 (4%). , This is because the garlic extract is unevenly distributed in the demulsification coating, which affects the insect resistance of the mulch.

As far as Comparative Example 14 is concerned, the results in Table 1 show that the concentration of _CO2 in the space covered by the mulch film prepared in Comparative Example 14 was 154 ppm at 12:00 during the day, which was far lower than that of the mulch films of Examples 1, 3, and 5. The _CO2 concentration is also much lower than the 300ppm concentration required for crop photosynthesis. The difference between Comparative Example 14 and Example 3 is that the negative heat material in the anti-insect ventilation layer is β-eucryptite, not β-eucryptite loaded with benzoyl peroxide, and no benzoyl peroxide is loaded. The β-eucryptite negative heating material cannot induce the polymerization of the organic monomers around the negative heating material particles on the surface of the particles, and it cannot form a dense and rigid polymer shell on the surface of the negative heating material particles, which causes When the temperature increases, the β-eucryptite particles shrink with the increase of temperature, but the less rigid polymer matrix around the β-eucryptite particles also shrinks and deforms, which leads to negative heat materials. There is no effective porosity between the polymer shell, so the mulch film in Comparative Example 14 has no effective ventilation effect, which leads to the fact that the mulch film in Comparative Example 14 cannot replenish the _CO2 in the fresh air from the outside into the space covered by the mulch film in time.

Table 1 The average temperature of the soil covered by the plastic film obtained in Example 1, Example 3, Example 5 and Comparative Example 6-14 at a depth of 5 cm; the average concentration of CO ₂ gas in the space covered by the plastic film; the hydrophilicity of the plastic film The average number of water droplets formed in the resistance test and the contact angle of the surface of the insect-proof ventilation layer; the experimental results of the leaf damage rate in the anti-diamond moth test

Claims (8)

1. The insect-proof ventilation mulching film is characterized in that a surface film layer (1) and an insect-proof ventilation layer (2) are sequentially arranged from top to bottom, ventilation holes (11) are distributed in the surface film layer, the insect-proof ventilation layer is composed of a garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material, a negative heat material (21) is beta-eucryptite loaded with benzoyl peroxide, and the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material comprises the following components in parts by weight: 10-30 parts of garlic extract, 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, 1-5 parts of chlorosulfonated polyethylene, 20-40 parts of polyvinyl alcohol and 4-12 parts of negative heat material; the preparation method of the insect-proof ventilation mulching film comprises the following steps:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain a solution A, then soaking 30 parts by weight of beta-eucryptite with the particle size of 100-32 meshes in the solution A at 25 ℃ for 15h, taking out the soaked beta-eucryptite, and airing at room temperature for 10h to obtain the benzoyl peroxide-loaded beta-eucryptite negative thermal material, wherein the benzoyl peroxide accounts for 0.1-0.12% of the total weight of the benzoyl peroxide-loaded beta-eucryptite negative thermal material;

(2) dissolving 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene in a container to obtain a solution B; dissolving a certain weight part of ammonium persulfate initiator in a certain weight part of deionized water to obtain a solution C; then adding 10-30 parts by weight of garlic extract, 2.9-3.2 parts by weight of sodium dodecyl sulfate, 3.9-4.3 parts by weight of OP-10 emulsifier, 20-40 parts by weight of polyvinyl alcohol and 107-258 parts by weight of deionized water into the solution B, and stirring at room temperature for 30min at the rotating speed of 350-360r/min to obtain emulsion D;

(3) heating a container containing the emulsion D in a water bath to a certain temperature, taking out 4-12 parts by weight of beta-eucryptite negative heat material particles loaded with benzoyl peroxide obtained in the step (1), adding the particles into the emulsion D, and adding 15-30 parts by weight of hydroxypropyl acrylate into the emulsion D while stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution C obtained in the step (2) into the emulsion D at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate;

(4) after the hydroxypropyl acrylate and the solution C are dropwise added in the step (3), heating the reaction system to a certain temperature, and stirring at a constant temperature at a certain stirring speed for reacting for a certain time; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain emulsion E;

(5) coating the emulsion E obtained in the step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.18-0.5mm, and drying at room temperature to obtain an insect-proof air exchange layer which is attached to the surface of the mask layer and consists of garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat materials;

the insect-proof ventilation mulching film can be obtained through the steps (1) - (5).

2. The anti-insect ventilation mulching film according to claim 1, wherein the material of the surface film layer is polyethylene or polyvinyl chloride, the pore size of the surface film layer is 0.5-3mm, and the distribution density of the air holes is 5-20/m ² 。

3. An insect-proof ventilation mulching film according to claim 1, wherein the garlic extract-hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composite negative heat material comprises the following components in parts by weight: 20 parts of garlic extract, 23 parts of hydroxypropyl acrylate, 3 parts of styrene, 3 parts of chlorosulfonated polyethylene, 30 parts of polyvinyl alcohol and 8 parts of negative thermal material.

4. An insect-proof ventilation mulching film according to claim 1, wherein the ammonium persulfate initiator in the preparation step (2) is 0.65 parts by weight, and the deionized water in which the ammonium persulfate initiator is dissolved is 10 parts by weight.

5. An anti-insect ventilation mulching film according to claim 1, wherein the sodium dodecyl sulfate in the preparation step (2) is 3 parts by weight, and the OP-10 emulsifier is 4.1 parts by weight.

6. An anti-insect ventilation mulch film according to claim 1 wherein the container of emulsion D in preparation step (3) is heated to a temperature of 82 ℃ in a water bath.

7. An insect-proof ventilation mulching film according to claim 1, wherein the temperature of the reaction system is raised to 85 ℃ after the hydroxypropyl acrylate and the solution C are added in the step (3) in the step (4).

8. An insect-proof ventilation mulching film according to claim 1, wherein the constant-temperature stirring reaction time in the preparation step (4) is 5 hours, and the stirring speed is 250 r/min.

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