CN112806199B - Breathable water-drop-free mulching film and preparation method thereof - Google Patents

Abstract

The invention provides a breathable water-drop-free mulching film and a preparation method thereof, wherein the mulching film is sequentially provided with a surface film layer, a temperature-adjustable ventilation layer and a hydrophilic layer from top to bottom, the surface film layer is distributed with ventilation holes, the temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material, and the negative heat material is ZrW loaded with benzoyl peroxide₂O₈The hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer. The prepared mulching film has the effects of improving the concentration of carbon dioxide gas in a mulching film covering space and reducing the concentration of ammonia gas, meanwhile, no obvious water drops are formed on the inner surface of the mulching film, and higher soil temperature can be maintained.

Description

A kind of breathable water droplet mulch film and preparation method thereof

Technical field:

The invention belongs to the technical field of agricultural mulch, and in particular relates to a breathable non-droplet mulch.

Background technique:

Soil drought caused by low temperature and lack of rainfall is the main factor limiting agricultural development in northern my country. In response to these limiting factors, agricultural plastic film technology has been widely used in northern my country. At present, it has been confirmed that mulching film on the surface of agricultural soil can indeed improve ground temperature, water conservation, fertilizer conservation, weed control, disease and insect prevention, salt suppression and seedling protection, and improvement of ground light and heat conditions. The traditional mulch film currently used is mostly plastic mulch film made of hydrophobic polymer material. When using, the whole piece of plastic mulch film is laid on the soil surface, that is, the mulch film 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 leads to the fact that the gas in the space covered by the traditional mulch cannot be exchanged with the fresh air outside. . However, the growth and development of crops requires respiration, that is, the photosynthesis of crops is to inhale CO ₂ in the environment and convert CO ₂ into nutrients required for crop growth. However, when crops are in a confined space, they cannot be ventilated in time. , 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, fertilizers such as urea are also used in agricultural soils to promote the growth of crops, but these urea fertilizers will undergo chemical changes in the soil and release harmful gases such as ammonia gas. and other harmful gases, ammonia gas will continue to accumulate to a higher concentration, which can easily lead to the death of vegetable plants. In actual agricultural production, farmers will make some holes in the traditional plastic film to ventilate the crops, but these holes are physical holes. After these physical holes are created, they will remain on the plastic film and cannot be closed automatically. As a result, the cold air from the outside will enter the space covered by the plastic film through these physical holes, so that the plastic film loses its thermal insulation effect.

In addition, the traditional mulch is generally a plastic mulch made of hydrophobic polymer material, which makes it easy to form water beads (or water droplets) on the inner surface facing the soil when the traditional mulch is used. The water droplets of the agricultural plastic film are more harmful to agricultural production. On the one hand, this kind of water droplets reduces the permeability of sunlight to the plastic film, and thus reduces the soil temperature covered by the plastic film. Spherical, spherical water droplets will focus sunlight, which can lead to burning seedlings, causing damage to agricultural production.

Invention content:

In order to solve the problems existing in the prior art, the present invention provides a breathable non-droplet mulch film and a preparation method thereof.

A breathable non-droplet mulch film, characterized in that the mulch film is provided with a mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom, and the mask layer Distributed with ventilation holes (11), the temperature-adjustable ventilation layer is composed of butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material, and the negative heat material (21) is loaded benzene peroxide Formyl ZrW ₂ O ₈ , the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material includes the following components in parts by weight: 20-35 parts of butyl acrylate, 2-7 parts of styrene parts, 1.5-6.5 parts of chlorosulfonated polyethylene, 3-8 parts of negative heat material, the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, the acrylic acid The hydroxypropyl ester-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, and 1-5 parts of chlorosulfonated polyethylene , 20-40 parts of polyvinyl alcohol; the preparation steps of a breathable and water-free mulch film are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, then soak ZrW ₂ O ₈ with a particle size of 100-32 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.1-0.12% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) Dissolve 1.5-6.5 parts by weight of chlorosulfonated polyethylene in 2-7 parts by weight of styrene in a container to obtain solution B; dissolve 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of Obtain solution C in ionized water; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water in solution B, at a rotating speed of 350-360r/min Emulsion D was obtained after stirring at room temperature for 30 min;

(3) heating the container containing the emulsion D to 82° C. in a water bath, then taking out 3-8 parts by weight from the benzoyl peroxide-loaded ZrW ₂ O ₈ negative heating material particles obtained in step (1) and adding In the emulsion D, 20-35 parts by weight of butyl 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; The solution C obtained in step (2) is added dropwise to the emulsion D, and the dripping speed is 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.1-0.3 mm, and drying at room temperature to obtain a transparent and adhered to the surface of the mask layer made of butyl acrylate- Temperature-adjustable ventilation layer composed of styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene to obtain solution F; dissolving 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) Then to the solution F obtained in step (6), add 20-40 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight The deionized water was stirred for 300min at room temperature between 350-360r/min to obtain emulsion H;

(8) the container that fills the emulsion H that step (7) obtains is heated to 82 ℃ in water bath, then at this temperature and stirring, the hydroxypropyl acrylate of 15-30 parts by weight is added to emulsion H, and the dripping speed is every 1 drop per 2 seconds, and the stirring speed is 250 r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dripping speed is 1 drop per 5 seconds; when hydroxypropyl acrylate is added dropwise After the dropwise addition of solution G and solution G, the reaction system was heated to 85 °C, and the reaction was stirred at a constant temperature for 5 hours at a stirring speed of 250 r/min; when the constant temperature stirring reaction was over, the obtained mixture was reduced to room temperature, and then concentrated Ammonia water adjusts the pH of the mixed solution to neutrality to obtain white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the surface of the temperature-adjustable ventilation layer obtained in step (5), the thickness of the control emulsion I layer is 0.08-0.2mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer. The hydrophilic layer on the surface of the gas layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through the steps (1)-(9), a breathable and water-droplet-free mulch film 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:

Effect Example The test results show that the mulch film prepared by the present invention has the effect of increasing the concentration of carbon dioxide gas and reducing the concentration of ammonia gas in the space covered by the mulch film. high soil temperature. This is because of the following factors:

1. In the present invention, the temperature-adjustable ventilation layer is composed of butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material, and the negative heat material is ZrW ₂ O ₈ loaded with benzoyl peroxide, and the negative heat material is ZrW 2 O 8 loaded with benzoyl peroxide. Thermal material is a material whose volume shrinks when heated and expands when cooled, and ZrW ₂ O ₈ is a negative thermal expansion material with excellent performance, which has negative thermal expansion performance in the temperature range of 0.3-1050.0K , that is, the negative thermal expansion behavior can be triggered at normal temperature or even lower temperature. Therefore, when the temperature is high during the day, the volume of the ZrW ₂ O ₈ negative heating material will shrink accordingly, so that the negative heating material particles will be separated from the polymer matrix of the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer to a certain extent. , resulting in the formation of pores in the ventilation layer, which can allow the air with higher temperature during the day to be exchanged to the space covered by the film, and then supplement the carbon dioxide in the outside air to the space covered by the film, while the ammonia in the space covered by the film is is exchanged into the extra-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 temperature-adjustable ventilation layer is ZrW ₂ O ₈ loaded with benzoyl peroxide. Benzoyl peroxide can initiate free radical polymerization of organic monomers with double bonds, so the load is too high. The ZrW ₂ O ₈ of benzoyl oxide can initiate the polymerization of the butyl acrylate and styrene monomers in the system of the present invention on the surface of the negative heating material particles to form a layer of strong and dense polymer shell wrapped around the negative heating material. The particle surface, which is beneficial to the formation of temperature controllable pores in the ventilation layer (this will be further explained in the analysis of the working principle of the mulch film of the present invention later).

3. Butyl acrylate and styrene in the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer make the copolymer have good film-forming properties, while the chlorosulfonated polyethylene has the ability to improve 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 make chlorosulfonated polyethylene have better compatibility with other components in the copolymer. , and the chlorosulfonated polyethylene molecular chain and other polymer chains in the copolymer are intertwined with each other at the molecular level to form a copolymer with more uniform distribution of components.

4. The hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, the hydroxypropyl acrylate monomer structure in the copolymer and the butyl acrylate monomer molecule in the ventilation layer Similar in structure, hydroxypropyl acrylate monomer has a hydrophilic hydroxyl group in addition to double bond and ester bond. The composition of the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer also includes a strongly hydrophilic polyvinyl alcohol component, and the two components of hydroxypropyl acrylate and polyvinyl alcohol in the hydrophilic layer are included. The water droplets can endow the hydrophilic layer with excellent hydrophilicity, so the contact angle of water droplets on the surface of the hydrophilic layer is small (not more than 10°), so that the condensed water droplets quickly spread out on the surface of the hydrophilic layer. flow away. Since there is no (or less) water droplets formed on the surface of the hydrophilic 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. It is beneficial for the breathable and water-droplet-free mulch film of the present invention to efficiently utilize solar energy, and to maintain a higher temperature of the soil covered by the mulch film.

5. The components of the hydrophilic layer and the temperature-adjustable ventilation layer are similar, and both layers contain styrene, chlorosulfonated polyethylene, and butyl acrylate and hydroxypropyl acrylate with similar structures, which makes the hydrophilic layer and the exchangeable layer. The air layers have good compatibility with each other, that is, the hydrophilic layer can be well attached to the surface of the temperature-adjustable air exchange layer without the problem of layer-to-layer separation caused by the incompatibility of the two layers, and The occurrence of water channeling between layers. In addition, the copolymers in the hydrophilic layer and the temperature-adjustable ventilation layer are both transparent and colorless, which can allow sunlight to easily pass through each layer of the film of the present invention, so that the soil covered by the plastic film is easily radiated by sunlight. It is beneficial to increase the temperature of the soil covered by the plastic film of the present invention.

6. The mask layer is distributed with ventilation holes, and the fresh air from the outside can enter the temperature-adjustable ventilation layer of the lower layer through these ventilation holes, and enter the space covered by the mulch film through these ventilation holes.

Document 1 (ZL2018101375050) reported a kind of anti-corrosion hydrophilic coating containing chlorinated natural rubber, the coating structure formed by the coating comprises that the upper layer is a hydrophilic surface layer containing polyvinyl alcohol resin, and the lower layer is a chlorinated natural rubber containing anti-corrosion layer, The surface of this coating also has the effect of spreading water droplets to achieve no water droplets, but this coating does not have a temperature-adjustable ventilation effect.

Document 2 (CN1485359A) reported a non-drip film for agriculture. The film is made by blending non-drip agent into low-density polyethylene, and then putting the material into a twin-screw extruder, melt extrusion, water cooling, and drying. Granulated, and then blown into a film with a film blowing machine. The mulch film is also only able to achieve the effect of no water droplets, but this coating also does not have a temperature-adjustable ventilation effect.

Document 3 (CN 104335850 A) also reported a double-layer mulch film with good air permeability. The mulch film has upper and lower layers, and the ventilation holes of the upper and lower layers are dislocated, so it has excellent air permeability, but the air permeability of the mulch film is still cannot vary with temperature.

Different from documents 1-3, the mulch film proposed by the present invention includes a temperature-adjustable air exchange layer and a hydrophilic layer, and the two layers are bonded together due to their similar components and can be compatible with each other, and the temperature-adjustable air exchange layer can Automatically adjust the ventilation of the plastic film with the change of the ambient temperature, thereby increasing the concentration of CO ₂ gas in the space covered by the plastic film, and reducing the concentration of NH ₃ in the space covered by the plastic film; the hydrophilic layer on the inner surface of the plastic film can make the inner surface of the plastic film not easy to condense. Water droplets make it easy for sunlight to penetrate the mulch, which is beneficial to increase the temperature of the soil.

Document 4 (Patent No.: 2020202046049) proposes a liquid rubber base film that is breathable and heat-absorbing. The film includes polyethylene-based films on both upper and lower surfaces, with a layer of liquid rubber composite humic acid air-drying and heat-absorbing in the middle. Membrane, a spherical negative heat material is embedded in the liquid rubber composite humic acid air-dried heat-absorbing membrane. The size of the pores on the surface of the mulch film in Reference 4 can change with the change of the ambient temperature, so it also has the effect of automatically adjusting the permeability of the mulch film with the ambient temperature. However, the upper and lower surfaces of the mulch film proposed in Document 4 are composed of hydrophobic polyethylene polymers, so it does not have the property of preventing water droplets. Furthermore, the mulch film in Document 4 is black and opaque, so sunlight is not easy to penetrate through the mulch film in Document 4, and this The water droplets formed by the mulch film made of a hydrophobic material will also absorb solar energy when it evaporates, which leads to the slow heating rate and low ground temperature of the space covered by the mulch film in Reference 4. The mulch film of the present invention is transparent, and the inner surface of the mulch film facing the soil is hydrophilic, and it is not easy to form water droplets, which causes sunlight to easily pass through the mulch film of the present invention, and no water droplets on the mulch film of the present invention absorb solar energy. Therefore, the mulch film of the present invention covers The heating rate of space is faster, and the ground temperature is higher.

The analysis of the working principle of a breathable water-droplet mulch film prepared by the present invention is as follows:

In the preparation step (1) of the present invention, the ZrW ₂ O ₈ 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 ZrW ₂ O ₈ particles, thereby forming a load ZrW ₂ O ₈ negative heating material of benzoyl peroxide, wherein the weight of adsorbed benzoyl peroxide can account for 0.1-0.12% of the total weight of the ZrW ₂ O ₈ negative heating material loaded with benzoyl peroxide; Compared with ZrW ₂ O ₈ without benzoyl peroxide, the ZrW ₂ O ₈ negative heating material particles loaded with benzoyl peroxide can induce the polymerization of butyl acrylate and styrene monomer molecules on the surface of negative heating material particles In this way, 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 during the day increases, When the negative heat material shrinks, because 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. A gap is formed between the bodies, 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 butyl acrylate-styrene-chlorosulfonated polyethylene copolymer. In the emulsion preparation step, the chlorosulfonated polyethylene is first Soluble in styrene, because chlorosulfonated polyethylene has good solubility in styrene, it can make chlorosulfonated polyethylene less likely to form particles or agglomerates in the emulsion, and cross-interact with other polymer chains in molecular form A high molecular copolymer with uniform distribution of components is formed. In addition, in steps (2)-(4), the ammonium persulfate initiator can initiate the polymerization of butyl 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 and can The resulting copolymer forms small oil-in-water particles suspended in solution to form an emulsion.

The preparation step (5) is to coat the composite negative heat material emulsion containing butyl acrylate-styrene-chlorosulfonated polyethylene copolymer on the polyethylene or polyvinyl chloride mask layer, wherein the chlorosulfonated polyethylene is to polyethylene. Or polyvinyl chloride has good adhesion, so that the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material emulsion is easily attached to the mask layer. A layer of solid coating containing butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material will be formed, and the solid layer can switch ventilation channels with temperature changes.

The preparation steps (6)-(8) are the reaction steps for preparing the emulsion containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer. Polyethylene copolymer composite negative heat material emulsion is similar.

The preparation step (9) is to coat the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer emulsion on the temperature-adjustable ventilation layer obtained in the step (5), and the hydroxypropyl acrylate -Because the styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer emulsion contains the same styrene and chlorosulfonated polyethylene components as in the ventilation layer, and the chlorosulfonated polyethylene has good adhesion, this The hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer emulsion is easily attached to the surface of the ventilation layer. After the moisture in the emulsion evaporates, a layer of hydroxypropyl acrylate is formed on the ventilation layer. Ester-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer solid coating, the solid coating has good hydrophilicity and can make water droplets spread out on its surface and flow away quickly, so that the present invention is a The surface of the hydrophilic layer of the breathable non-droplet mulch film has the property of not forming water droplets.

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 view of a breathable water-droplet-free mulch film of the present invention.

Fig. 2 is a cross-sectional view of a breathable non-droplet mulch film of the present invention.

Numerals in the figure: 1-mask layer; 2-temperature-adjustable ventilation layer; 3-hydrophilic layer; 11-breathing 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;

ZrW ₂ O ₈ powder with a purity of 99.5% was purchased from Shanghai Dianyang Industrial Co., Ltd. After sieving, particles with different mesh numbers were screened out for use 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, a breathable non-droplet mulch film, the mulch film is provided with a polyethylene mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom. The polyethylene mask layer is distributed with ventilation holes (11), the diameter of the ventilation holes is 3 mm, the distribution density of the ventilation holes in the mask layer is 20/m ² , and the temperature-adjustable ventilation layer is made of butyl acrylate- Styrene-chlorosulfonated polyethylene copolymer composite negative heat material, the negative heat material (21) is ZrW ₂ O ₈ loaded with benzoyl peroxide, the butyl acrylate-styrene-chlorosulfonated polyethylene The copolymer composite negative heat material includes the following components in parts by weight: 20 parts of butyl acrylate, 2 parts of styrene, 1.5 parts of chlorosulfonated polyethylene, 8 parts of negative heat material, and the hydrophilic layer is composed of hydroxypropyl acrylate-benzene Ethylene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is composed, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer includes the following components in parts by weight: 30 parts of hydroxypropyl acrylate , 5 parts of styrene, 5 parts of chlorosulfonated polyethylene, and 40 parts of polyvinyl alcohol; the preparation steps of a breathable water-drop-free mulch film are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, then soak ZrW ₂ O ₈ with a particle size of 100-80 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.1% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) In a container, 1.5 parts by weight of chlorosulfonated polyethylene is dissolved in 2 parts by weight of styrene to obtain solution B; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir 30min at room temperature between 350r/min at a rotating speed Then obtain emulsion D;

(3) The container containing the emulsion D is heated to 82° C. in a water bath, and then 8 parts by weight are taken out from the benzoyl peroxide-loaded ZrW ₂ O ₈ negative heating material particles obtained in step (1) and added to the emulsion D, under stirring, 20 parts by weight of butyl acrylate was added dropwise into the emulsion D, the dripping speed was 1 drop per 2 seconds, and the stirring speed was 250r/min; while adding butyl acrylate dropwise, step (2) was also added. The obtained solution C was added dropwise to the emulsion D at a rate of 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.1 mm, and drying at room temperature to obtain a transparent butyl acrylate-styrene attached to the surface of the mask layer - A temperature-adjustable ventilation layer composed of chlorosulfonated polyethylene copolymer composite negative heat material;

(6) 5 parts by weight of chlorosulfonated polyethylene is dissolved in 5 parts by weight of styrene to obtain solution F; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain solution G;

(7) Then add 40 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300min at a rotational speed of 360r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then at this temperature and stirring, 30 parts by weight of hydroxypropyl acrylate is added to the emulsion H, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the completion of the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 h at this temperature, and the stirring speed was 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the temperature-adjustable ventilation layer surface obtained in step (5), and the thickness of the control emulsion I layer is 0.08mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer Surface hydrophilic layer composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through steps (1)-(9), a breathable water-droplet-free mulch film of Example 1 can be obtained.

Example 2

Referring to the accompanying drawings, a breathable non-droplet mulch film, the mulch film is provided with a polyvinyl chloride mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom. The polyvinyl chloride mask layer is distributed with ventilation holes (11), the diameter of the ventilation holes is 2.3mm, the distribution density of the ventilation holes in the mask layer is 17/m ² , and the temperature-adjustable ventilation layer is made of acrylic acid. The composition of butyl ester-styrene-chlorosulfonated polyethylene copolymer composite negative heating material, the negative heating material (21) is ZrW ₂ O ₈ loaded with benzoyl peroxide, and the butyl acrylate-styrene-chlorosulfonic acid The polyethylene copolymer composite negative heat material includes the following components in parts by weight: 24 parts of butyl acrylate, 3 parts of styrene, 2.5 parts of chlorosulfonated polyethylene, 6 parts of negative heat material, and the hydrophilic layer is made of hydroxypropyl acrylate. Ester-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: hydroxypropyl acrylate 27 parts of esters, 4 parts of styrene, 4 parts of chlorosulfonated polyethylene, and 35 parts of polyvinyl alcohol; the preparation steps of a breathable non-droplet mulch film are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, then soak ZrW ₂ O ₈ with a particle size of 80-65 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.11% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) Dissolve 2.5 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene in a container to obtain solution B; dissolve 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir at room temperature for 30min between 355r/min at a rotating speed to obtain emulsion D;

(3) The container containing the emulsion D is heated to 82° C. in a water bath, and then 6 parts by weight are taken out from the ZrW ₂ O ₈ negative heating material particles loaded with benzoyl peroxide obtained in step (1) and added to the emulsion In D, 24 parts by weight of butyl acrylate was added dropwise into the emulsion D under stirring, and the dripping speed was 1 drop per 2 seconds, and the stirring speed was 250 r/min; while adding butyl acrylate dropwise, also step (2) ) The obtained solution C is added dropwise to the emulsion D, and the dripping rate is 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.1 mm, and drying at room temperature to obtain a transparent butyl acrylate-styrene attached to the surface of the mask layer - A temperature-adjustable ventilation layer composed of chlorosulfonated polyethylene copolymer composite negative heat material;

(6) 4 parts by weight of chlorosulfonated polyethylene is dissolved in 4 parts by weight of styrene to obtain solution F; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain solution G;

(7) Then add 35 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300min at a rotating speed of 355r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then at this temperature and stirring, 27 parts by weight of hydroxypropyl acrylate is added to the emulsion H, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the completion of the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 h at this temperature, and the stirring speed was 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the temperature-adjustable ventilation layer surface that step (5) obtains, and the thickness of the control emulsion I layer is 0.12mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer Surface hydrophilic layer composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through steps (1)-(9), a breathable water-droplet-free mulch film of Example 2 can be obtained.

Example 3

Referring to the accompanying drawings, a breathable non-droplet mulch film, the mulch film is provided with a polyethylene mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom. The polyethylene mask layer is distributed with ventilation holes (11), the diameter of the ventilation holes is 1.7mm, the distribution density of the ventilation holes in the mask layer is 13/m ² , and the temperature-adjustable ventilation layer is made of butyl acrylate -Styrene-chlorosulfonated polyethylene copolymer composite negative heat material, the negative heat material (21) is ZrW ₂ O ₈ loaded with benzoyl peroxide, the butyl acrylate-styrene-chlorosulfonated polyethylene The ethylene copolymer composite negative heat material includes the following components in parts by weight: 28 parts of butyl acrylate, 4 parts of styrene, 3.5 parts of chlorosulfonated polyethylene, 5 parts of negative heat material, and the hydrophilic layer is composed of hydroxypropyl acrylate- Styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is composed, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer includes the following components in parts by weight: hydroxypropyl acrylate 23 parts, 3 parts of styrene, 3 parts of chlorosulfonated polyethylene, and 30 parts of polyvinyl alcohol;

The preparation steps of a breathable water-droplet mulch film are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then soak 30 parts by weight of ZrW ₂ O ₈ with a particle size of 65-60 mesh at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.1% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) Dissolve 3.5 parts by weight of chlorosulfonated polyethylene in 4 parts by weight of styrene in a container to obtain solution B; dissolve 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir at room temperature for 30min between 360r/min at a rotating speed Then obtain emulsion D;

(3) heating the container containing the emulsion D to 82° C. in a water bath, then taking out 5 parts by weight from the benzoyl peroxide-loaded ZrW ₂ O ₈ negative heating material particles obtained in step (1) and adding it to the emulsion In D, under stirring, 28 parts by weight of butyl acrylate was added dropwise into emulsion D, the dripping speed was 1 drop per 2 seconds, and the stirring speed was 250 r/min; while adding butyl acrylate dropwise, step (2) was also added. The obtained solution C was added dropwise to the emulsion D at a rate of 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) The white 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 0.15 mm, and after drying at room temperature, a transparent, butyl acrylate-styrene film attached to the surface of the mask layer is obtained. - A temperature-adjustable ventilation layer composed of chlorosulfonated polyethylene copolymer composite negative heat material;

(6) 3 parts by weight of chlorosulfonated polyethylene is dissolved in 3 parts by weight of styrene to obtain solution F; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain solution G;

(7) Then add 30 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300 min at a rotational speed of 350 r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then at this temperature and stirring, 23 parts by weight of hydroxypropyl acrylate is added to the emulsion H, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the completion of the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 h at this temperature, and the stirring speed was 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the temperature-adjustable ventilation layer surface obtained in step (5), and the thickness of the control emulsion I layer is 0.1 mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer Surface hydrophilic layer composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through steps (1)-(9), a breathable water-droplet-free mulch film of Example 3 can be obtained.

Example 4

Referring to the accompanying drawings, a breathable non-droplet mulch film, the mulch film is provided with a polyethylene mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom. The polyethylene mask layer is distributed with ventilation holes (11), the diameter of the ventilation holes is 1.1 mm, the distribution density of the ventilation holes in the mask layer is 9/m ² , and the temperature-adjustable ventilation layer is made of butyl acrylate -Styrene-chlorosulfonated polyethylene copolymer composite negative heat material, the negative heat material (21) is ZrW ₂ O ₈ loaded with benzoyl peroxide, the butyl acrylate-styrene-chlorosulfonated polyethylene The ethylene copolymer composite negative heat material includes the following components in parts by weight: 32 parts of butyl acrylate, 6 parts of styrene, 5 parts of chlorosulfonated polyethylene, 4 parts of negative heat material, and the hydrophilic layer is composed of hydroxypropyl acrylate- Styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is composed, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer includes the following components in parts by weight: hydroxypropyl acrylate 19 parts, 2 parts of styrene, 2 parts of chlorosulfonated polyethylene, 25 parts of polyvinyl alcohol;

The preparation steps of a breathable water-droplet mulch film are as follows:

(1) Dissolve 1 weight part of benzoyl peroxide in 99 weight parts of toluene solvent to obtain solution A, and then soak ZrW ₂ O ₈ with a particle size of 60-48 mesh and 30 weight parts at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.12% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) Dissolve 5 parts by weight of chlorosulfonated polyethylene in 6 parts by weight of styrene in a container to obtain solution B; dissolve 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir at room temperature for 30min between 355r/min at a rotating speed Then obtain emulsion D;

(3) heat the container containing the emulsion D to 82° C. in a water bath, then take out 4 parts by weight from the benzoyl peroxide-loaded ZrW ₂ O ₈ negative heating material particles obtained in step (1) and add it to the emulsion D , 32 parts by weight of butyl acrylate was added dropwise into the emulsion D under stirring, the dripping speed was 1 drop per 2 seconds, and the stirring speed was 250 r/min; while the butyl acrylate was added dropwise, step (2) was also obtained. The solution C was added dropwise to the emulsion D at a rate of 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.2 mm, and drying at room temperature to obtain a transparent butyl acrylate-styrene attached to the surface of the mask layer - A temperature-adjustable ventilation layer composed of chlorosulfonated polyethylene copolymer composite negative heat material;

(6) 2 parts by weight of chlorosulfonated polyethylene is dissolved in 2 parts by weight of styrene to obtain solution F; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain solution G;

(7) Then add 25 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300min at a rotating speed of 355r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then at this temperature and stirring, 19 parts by weight of hydroxypropyl acrylate is added to the emulsion H, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the completion of the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 h at this temperature, and the stirring speed was 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the temperature-adjustable ventilation layer surface obtained in step (5), and the thickness of the control emulsion I layer is 0.1 mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer Surface hydrophilic layer composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through steps (1)-(9), a breathable water-droplet-free mulch film of Example 4 can be obtained.

Example 5

Referring to the accompanying drawings, a breathable non-droplet mulch film, the mulch film is provided with a polyvinyl chloride mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) in sequence from top to bottom. The polyvinyl chloride mask layer is distributed with ventilation holes (11), the diameter of the ventilation holes is 0.5mm, the distribution density of the ventilation holes in the mask layer is 5/m ² , and the temperature-adjustable ventilation layer is made of acrylic acid. The composition of butyl ester-styrene-chlorosulfonated polyethylene copolymer composite negative heating material, the negative heating material (21) is ZrW ₂ O ₈ loaded with benzoyl peroxide, and the butyl acrylate-styrene-chlorosulfonic acid The polyethylene copolymer composite negative heat material includes the following components in parts by weight: 35 parts of butyl acrylate, 7 parts of styrene, 6.5 parts of chlorosulfonated polyethylene, 3 parts of negative heat material, and the hydrophilic layer is made of hydroxypropyl acrylate. Ester-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: hydroxypropyl acrylate 15 parts of ester, 1 part of styrene, 1 part of chlorosulfonated polyethylene, 20 parts of polyvinyl alcohol;

The preparation steps of a breathable water-droplet mulch film are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then soak ZrW ₂ O ₈ with a particle size of 48-32 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.12% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

(2) In a container, 6.5 parts by weight of chlorosulfonated polyethylene is dissolved in 7 parts by weight of styrene to obtain solution B; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir 30min at room temperature between 350r/min at a rotating speed to obtain emulsion D;

(3) The container containing the emulsion D is heated to 82° C. in a water bath, and then 3 parts by weight are taken out from the ZrW ₂ O ₈ negative heating material particles loaded with benzoyl peroxide obtained in step (1) and added to the emulsion In D, under stirring, 35 parts by weight of butyl acrylate was added dropwise into emulsion D, the dripping speed was 1 drop per 2 seconds, and the stirring speed was 250 r/min; while adding butyl acrylate dropwise, step (2) was also added. The obtained solution C was added dropwise to the emulsion D at a rate of 1 drop every 5 seconds;

(4) after the dropwise addition of butyl acrylate and solution C in 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; after the constant temperature stirring reaction is completed , 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 white emulsion E;

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.3 mm, and drying at room temperature to obtain a transparent butyl acrylate-styrene attached to the surface of the mask layer - A temperature-adjustable ventilation layer composed of chlorosulfonated polyethylene copolymer composite negative heat material;

(6) 1 weight part of chlorosulfonated polyethylene is dissolved in 1 weight part of styrene to obtain solution F; 0.5 weight part of ammonium persulfate initiator is dissolved in 20 weight parts of deionized water to obtain solution G;

(7) Then add 20 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300min at a rotational speed of 360r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then at this temperature and stirring, 15 parts by weight of hydroxypropyl acrylate is added to the emulsion H, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the completion of the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 h at this temperature, and the stirring speed was 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

(9) the white emulsion I obtained in step (8) is coated on the temperature-adjustable ventilation layer surface obtained in step (5), and the thickness of the control emulsion I layer is 0.2 mm, and after drying at room temperature, it is obtained to be attached to the ventilation layer Surface hydrophilic layer composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

Through steps (1)-(9), a breathable water-droplet-free 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 4. The difference between this example and Example 4 is that there is no negative heat material in the temperature-adjustable ventilation layer. The pore size, density, component composition and component content are the same as in Example 4. The preparation steps of this embodiment are as follows:

(1) In a container, 5 parts by weight of chlorosulfonated polyethylene is dissolved in 6 parts by weight of styrene to obtain solution B; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain a solution C; then add 2.3 parts by weight of sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, 20 parts by weight of deionized water, and stir at room temperature for 30min between 355r/min at a rotating speed to obtain emulsion D;

(2) the container containing emulsion D is heated to 82 ℃ in water bath, and the butyl acrylate of 32 parts by weight 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 butyl acrylate dropwise, the solution C obtained in step (1) was also added dropwise to the emulsion D at a rate of 1 drop per 5 seconds;

The rest of the preparation steps are the same as the preparation steps (4)-(9) of Example 4.

Comparative Example 7

In this example, the mulch film is prepared according to Example 4. The difference between this example and Example 4 is that the negative heat material in the temperature-adjustable ventilation layer is ZrW ₂ O ₈ instead of ZrW loaded with benzoyl peroxide. ₂ O ₈ , other aspects related to the structure of the mulch film, the material of the mask layer, the pore size and density of the ventilation holes, the composition of the components and the content of the components are the same as those in Example 4. The preparation steps of this embodiment are as follows:

(1) In a container, 5 parts by weight of chlorosulfonated polyethylene is dissolved in 6 parts by weight of styrene to obtain solution B; a total amount of 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized Obtain solution C in water; Then add the sodium dodecyl sulfonate of 2.3 weight parts, the OP-10 emulsifier of 3.1 weight parts, the deionized water of 20 weight parts to solution B, be room temperature between 355r/min at rotating speed Under stirring for 30min, emulsion D was obtained;

(2) The container containing the emulsion D is heated to 82° C. in a water bath, and then ZrW ₂ O ₈ particles with a size of 60-48 mesh and 4 parts by weight are added to the emulsion D obtained in step (2), and then stirred again. 32 parts by weight of butyl acrylate was added dropwise to the emulsion D, the dripping speed was 1 drop every 2 seconds, and the stirring speed was 250 r/min; while the butyl acrylate was added dropwise, the solution C obtained in step (1) was also added dropwise. In Emulsion D, the dripping rate is 1 drop every 5 seconds;

The rest of the preparation steps are the same as the preparation steps (4)-(9) of Example 4.

Comparative Example 8

In this example, the mulch film is prepared according to Example 4. The difference between this example and Example 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 9-28 meshes, and the amount is specified in the claims. Outside the above-mentioned range, other aspects related to the structure of the mulch film, the material of the mask layer, the pore size and density of the ventilation holes, the composition of the components and the content of the components are the same as those in Example 4. The preparation steps of this embodiment are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then soak ZrW ₂ O ₈ with a particle size of 9-28 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.12% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

The rest of the preparation steps are the same as the preparation steps (2)-(9) of Example 4.

Comparative Example 9

In this example, the mulch film is prepared according to Example 4. The difference between this example and Example 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 115-400 mesh, and the amount is specified in the claims. Outside the above-mentioned range, other aspects related to the structure of the mulch film, the material of the mask layer, the pore size and density of the ventilation holes, the composition of the components and the content of the components are the same as those in Example 4. The preparation steps of this embodiment are as follows:

(1) Dissolve 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then soak ZrW ₂ O ₈ with a particle size of 115-400 mesh and 30 parts by weight at 25° C. In solution A for 15h, the soaked ZrW ₂ O ₈ was taken out, and air-dried at room temperature for 10 hours to obtain a ZrW ₂ O ₈ negative heat material loaded with benzoyl peroxide. 0.12% of the total weight of formyl ZrW ₂ O ₈ negative thermal material;

The rest of the preparation steps are the same as the preparation steps (2)-(9) of Example 4.

Comparative Example 10

In this example, the mulch film is prepared according to Example 4. The difference between this example and Example 4 is that the amount of hydroxypropyl acrylate in the ventilation layer is 10 parts by weight, and the amount of polyvinyl alcohol is 15 parts by weight. All are outside the scope described in the claims, and other aspects related to the mulching film structure, the material of the mask layer, the pore size and density of the ventilation holes, the component composition and the component content are the same as those in Example 4. The preparation steps of this embodiment are as follows:

The preparation steps (1)-(6) in this example are the same as the steps (1)-(6) in Example 4.

(7) Then add 15 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfonate, 5.1 parts by weight of OP-10 emulsifier, 50 parts by weight of emulsifier to the solution F obtained in step (6) Ionized water was stirred at room temperature for 300min at a rotating speed of 355r/min to obtain emulsion H;

(8) the container containing the emulsion H obtained in step (7) is heated to 82° C. in a water bath, then 10 parts by weight of hydroxypropyl acrylate is added to the emulsion H at this temperature and stirring, and the dripping speed is every 2 seconds 1 drop, the stirring speed is 250r/min; while adding hydroxypropyl acrylate dropwise, the solution G obtained in step (6) is also added dropwise to the emulsion H, and the dropping speed is 1 drop every 5 seconds; After the dropwise addition of G, the reaction system was heated to 85°C, and the reaction was stirred at a constant temperature for 5 hours at a stirring speed of 250 r/min; when the constant temperature stirring reaction was completed, the obtained mixed solution was lowered to room temperature, and then concentrated ammonia water was added to adjust The pH of the mixed solution is neutral to obtain a white emulsion I;

The preparation step (9) of this example is the same as the preparation step (9) of Example 4.

Comparative Example 11

In this example, the mulch film is prepared according to the description in Example 4. The difference between this example and Example 4 is that there is no chlorosulfonated polyethylene in the ventilation layer and the hydrophilic layer. The pore diameter and density of the pores, the composition of the components and the content of the components are the same as those in Example 4. 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 4.

(2) adding 6 parts by weight of styrene in the container to obtain solution B; dissolving 0.5 parts by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution C; then adding 2.3 parts by weight of solution B Sodium dodecyl sulfonate, 3.1 parts by weight of OP-10 emulsifier, and 20 parts by weight of deionized water were stirred at room temperature between 355 r/min for 30 min to obtain emulsion D;

The preparation steps (3) and (4) of this example are the same as the steps (3) and (4) of Example 4.

(5) Coating the white emulsion E obtained in step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.2 mm, and drying at room temperature to obtain a transparent butyl acrylate-styrene attached to the surface of the mask layer A temperature-adjustable ventilation layer composed of a copolymer composite negative heat material;

(6) adding 2 parts by weight of styrene in the container to obtain solution F; 0.5 parts by weight of ammonium persulfate initiator is dissolved in 20 parts by weight of deionized water to obtain solution G;

The preparation steps (7) and (8) of this example are the same as the steps (7) and (8) of Example 4.

(9) the white emulsion I obtained in step (8) is coated on the surface of the ventilation layer obtained in step (5), the thickness of the control emulsion I layer is 0.1 mm, and after drying at room temperature, the acrylic acid attached to the surface of the ventilation layer is obtained Hydrophilic layer composed of hydroxypropyl ester-styrene-polyvinyl alcohol copolymer.

Comparative Example 12

In this example, a mulch film is prepared according to document 4. The middle layer of the mulch film also contains negative heat material, but the negative heat material is ZrW ₂ O ₈ instead of ZrW ₂ O ₈ loaded with benzoyl peroxide. Both layers are polyethylene films, and the preparation steps of the mulch film in this embodiment are as follows:

(1) First, dissolve 1 part by weight of liquid rubber in 3 parts by weight of toluene solvent, when the liquid rubber is completely dissolved, add 1 part by weight of black humic acid powder to the solution, stir at room temperature for 10h, stirring speed is 250r/min, and black liquid rubber compound humic acid glue is obtained after stirring;

(2) adding 65-80 mesh ZrW ₂ O ₈ negative heat material particles to the liquid rubber compound humic acid glue obtained in step 1, wherein the weight of the ZrW ₂ O ₈ particles and the liquid natural rubber compound humic acid glue The ratio is 1:26.8 (excluding the solvent in the glue solution, this weight ratio is the same as the proportion of the negative heat material in the copolymer of the ventilation layer in Example 4), and then stirred at room temperature for 10h at a stirring speed of 250r/ min, after stirring, a liquid rubber compound humic acid glue solution containing ZrW ₂ O ₈ negative heat material particles was obtained;

(3) apply the liquid rubber compound humic acid glue solution containing ZrW ₂ O ₈ negative heat material particles obtained in step (2) on a layer with air holes (the aperture is 1.1 mm, and the distribution density of the air holes is 9 pcs/m ² , same as Example 4) on the polyethylene film, the thickness of the liquid natural rubber compound humic acid glue solution containing ZrW ₂ O ₈ negative heat material particles is controlled to be 0.2mm (same as the thickness of the intermediate layer in Example 4) The same), and then lay a layer with air holes (the pore size is _1.1mm , and the distribution density of the air holes is ₉ Pieces/m ² ) of polyethylene film to obtain a three-layer composite film, that is, the upper and lower layers are both polyethylene films with ventilation holes, and the middle layer is a liquid rubber compound humic acid glue containing ZrW ₂ O ₈ negative heat material particles liquid layer;

(4) air-drying the composite film obtained in step (3) at 50-70 ° C, so that the organic solvent in the glue solution of the middle layer of the composite film is volatilized from the ventilation holes on the upper and lower polyethylene films, and finally a black Mulch.

Application Example 13

In this example, the mulch films obtained in Example 1, Example 4, Example 5, and Comparative Examples 6-12 are covered on the soil surface, and the specific test steps are as follows:

(1) Select a vegetable planting field, the location is east longitude: 118.97539027571867° and north latitude: 32.066403113172214°, and plant chrysanthemum in the field;

(2) On November 2, 2018, urea fertilizer was applied to the field, and the applied amount of urea was 25g/m ² , and the field was divided into 10 fields with a size of 0.5m×0.5m, and the interval between each field was 0.1 m;

(3) Take the mulch films prepared in Example 1, Example 4, Example 5, and Comparative Examples 6-12, cut out a size of 0.8m×0.8m on the mulch film, and lay them on the 10 fields respectively, with the mulch film off the ground With a height of about 10cm, the edge of each mulch film is buried 5cm underground at the edge of each field, and compacted with soil blocks to ensure that the space surrounded by the mulch film is a closed space.

Effect Example

In this example, the following performance tests were performed on the mulch films obtained by applying Example 13 (including those obtained in Example 1, Example 4, Example 5, and Comparative Examples 6-12).

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 5 to 7, 2018. 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 .

2. Test and test of mulching film ventilation performance.

(1) CO ₂ gas test

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 time period is 3 consecutive days from November 5-7, 2018. 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.

(2) NH ₃ gas concentration test

Using GPRS type ammonia gas sensor (model: JXBS-7001-NH3, supplier: Jingxun Changtong Electronic Technology Co., Ltd., the sensor relies on mobile phone signal network for ammonia gas concentration data transmission in gas) to automatically measure and upload NH in the space covered by plastic film ₃ Average concentration of gas. The measurement time period is 3 consecutive days from November 5-7, 2018. The measurement time is 12:00 during the day and 2:00 at night. The average concentration of NH ₃ = (the sum of the concentration of NH ₃ at a certain time point in 3 days) /3.

3. Water drop test on plastic film

An area of 0.1m × 0.1m is selected on the mulch, and the average number of water droplets larger than 2mm in diameter in this area is counted. Literature 4 (Zhang Shengjun et al., Research on the burn of drip irrigation tape by condensed water droplets under the film [J], Water Saving Irrigation, 2014, 6, 29-31) introduced that when the diameter of the water droplets in the plastic film is greater than a certain value (for example: 5mm), the water droplets The formed lens body can focus the sunlight and can obviously burn the crops under the mulch film, so the less the number of water droplets on the mulch film, the more beneficial to agricultural production. The measurement time period is 3 consecutive days from November 5 to 7, 2018. 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.

4. Contact angle test on the side of the mulch 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 fix the 3 film samples with the soil-facing side facing up on the workbench. 0.01ml of distilled water forms water droplets on the needle, and drops on the surface of the film sample. When the water droplets stand on the film sample for 50s, turn the cross line in the eyepiece to make a tangent at the contact point between the water droplet and the film sample. The angle between the sample planes 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.

5. It can be seen from the results in Table 1-4 that the soil surface of Examples 1, 4, and 5 is covered with plastic film, and their corresponding soil temperature can be maintained at 15.9-16.1 °C at 12:00 during the day. The ambient temperature is similar; the soil temperature can be maintained at 15.4-15.7°C at 2 o'clock at night, which can be about 8.6°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, 4, and 5 can be much higher than the external environment. temperature. Examples 1, 4, and 5 The carbon dioxide concentration range of the space covered by plastic film is 370-381 ppm at 12:00 during the day, and the concentration range of carbon dioxide at 2:00 at night is 968-1000 ppm. The carbon dioxide concentration in the plastic film-covered space at night is higher than that in the daytime. The reason is that crops mainly rely on photosynthesis during the day under the action of sunlight, which will absorb carbon dioxide. At night, crops mainly rely on respiration, and they will exhale a large amount of carbon dioxide at night. Although the carbon dioxide concentration of the mulching space in Examples 1, 4, and 5 became lower during the day, the carbon dioxide concentration was still higher than the 300 ppm required for photosynthesis, which was sufficient to maintain the normal photosynthesis of crops. This is because the ventilation holes on the plastic films of Examples 1, 4, and 5 are open during the day, and carbon dioxide in the outside atmosphere can be supplemented into the space covered by the plastic film, so that the carbon dioxide concentration in the space covered by the plastic film will not drop too low. Examples 1, 4, and 5 The space covered by plastic film has an ammonia concentration range of 0.7-0.9 ppm at 12 o'clock in the daytime, and a ammonia concentration range of 0.9-1.2 ppm at 2 o'clock at night. Such an ammonia gas range is much lower than 5ppm, will not cause damage to the growth of crops, this is because the ventilation holes of the mulch films of Examples 1, 4, and 5 can be opened during the day, so that the harmful ammonia gas can be released into the external environment in time, and will not be covered by the mulch film. accumulation in space. The contact angles of the hydrophilic layers of the mulch films of Examples 1, 4, and 5 were all less than 10°, indicating that the hydrophilic layers of the mulch films of Examples 1, 4, and 5 had excellent hydrophilicity, and water droplets would spread out on such a hydrophilic layer. No water droplets will form. The results in Table 4 show that no obvious water droplets are found on the surface of the mulch films of Examples 1, 4, and 5, indicating that the hydrophilic layer of the mulch films of the above examples has the effect of not forming water droplets. The above all illustrate that the mulch film prepared under the component range and preparation method described in the claims of the present invention can effectively maintain the temperature of the soil, effectively increase the carbon dioxide gas concentration in the space covered by the mulch film, reduce the concentration of ammonia harmful gas, At the same time, there are no obvious water droplets on the mulch.

As far as Comparative Example 6 is concerned, the results in Table 2 show that the carbon dioxide concentration in the space covered by the mulch film prepared by Comparative Example 6 is 100 ppm at 12:00 during the day, which is far lower than the 300 ppm required for crop photosynthesis; The ammonia concentration in the space covered by the mulch film prepared in Example 6 was 46-5.2 ppm, which was 5.1-7.4 times the ammonia concentration in the space covered by the mulch film prepared in Example 4. The difference between Comparative Example 6 and Example 4 is that there is no negative heat material in the temperature-adjustable 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 contrast. The mulch film in Example 6 could not replenish carbon dioxide from the outside fresh air into the mulch film space in time, nor could it discharge the harmful ammonia gas in the space covered by the mulch film in Comparative Example 6 in time.

As far as Comparative Example 7 is concerned, the results in Table 2 show that the concentration of carbon dioxide in the space covered by the mulch film prepared in Comparative Example 7 is 210 ppm at 12:00 during the day, which is far lower than the 300 ppm concentration required for crop photosynthesis; The concentration of ammonia in the space covered by the mulch film prepared in Comparative Example 7 was 4.1-4.2 ppm, which was 4.6-6 times that of the space covered by the mulch film in Example 4. The difference between Comparative Example 7 and Example 4 is that the negative heat material in the temperature-adjustable ventilation layer is ZrW ₂ O ₈ , not ZrW ₂ O ₈ loaded with benzoyl peroxide, and no supported benzoyl peroxide The acyl ZrW ₂ O ₈ negative heat material cannot initiate the polymerization of the organic monomers around the negative heat material particles on the surface of the negative heat material particles, so that a dense and rigid polymer shell cannot be formed on the surface of the negative heat material particles, which causes When the temperature increases, the ZrW ₂ O ₈ particles shrink with the increase of the temperature, but the less rigid polymer matrix around the ZrW ₂ O ₈ particles also shrinks and deforms, which leads to the negative heat material and high temperature. There are no effective pores between the molecular shells, so the mulch film in Comparative Example 7 has no effective ventilation effect, which leads to the fact that the mulch film in Comparative Example 7 cannot replenish the carbon dioxide in the fresh outside air into the space covered by the mulch film in time, nor can it discharge the mulch film in time. Covers the ammonia gas in the space.

As far as Comparative Example 8 is concerned, the results in Table 1 show that the temperature of the soil covered by the mulch film prepared in Comparative Example 8 was 10.1°C at 2 o'clock at night, which was 5.6°C lower than that of Example 4. No effective maintenance of soil temperature at night. This is because the difference between Comparative Example 8 and Example 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 9-28 mesh, that is, the particle size of the negative heat material is larger than the range described in the claims , which makes the particle size of the negative heat material far exceed the sum of the thicknesses of the ventilation layer and the hydrophilic layer, that is, some particles of the negative heat material not only penetrate through the air exchange layer and the hydrophilic layer, but also protrude from the surface of the hydrophilic layer. , which makes it difficult for the polymer matrix or shell to effectively coat the negative heat material, that is, there will always be large void defects between the negative heat material particles and the polymer matrix, so the cold air at night will pass through these large gaps. The voids enter into the space covered by the plastic film, so that the temperature of the soil covered by the plastic film decreases too quickly at night.

As far as Comparative Example 9 is concerned, the results in Table 2 show that the carbon dioxide concentration in the space covered by the mulch film of Comparative Example 9 is 180 ppm at 12:00 during the day, which is far lower than the 300 ppm required for crop photosynthesis; The ammonia concentration in the space covered by the mulch film of Example 4 also reached 4.0-4.1 ppm, which was 4.6-5.8 times the ammonia concentration in the space covered by the mulch film in Example 4. This is because the difference between Comparative Example 9 and Example 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 115-400 mesh, which is lower than the range described in the claims, which leads to The negative heat material particles are too deeply buried in the ventilation layer and the hydrophilic layer, and the gap between the negative heat material and the polymer matrix is also deeply buried in the polymer matrix, while the surface of the ventilation layer and the hydrophilic layer has no obvious pores. , which makes it difficult to achieve effective gas exchange inside and outside the membrane.

As far as Comparative Example 10 is concerned, the results in Table 4 show that the number of water droplets formed on the mulch film prepared in Comparative Example 10 reached 40, and the contact angle of the hydrophilic layer was 113°, which was much higher than that of the mulch film prepared in Example 4. The resulting water droplets have a contact angle of 4° with the hydrophilic layer. This is because the difference between Comparative Example 10 and Example 4 is that the amount of hydroxypropyl acrylate in the ventilation layer is 10 parts by weight, and the amount of polyvinyl alcohol is 15 parts by weight, both of which are lower than those described in the claims. , which will lead to too few hydrophilic components in the hydrophilic layer, making it difficult for the hydrophilic layer of the mulch film of Comparative Example 10 to spread the water droplets and form more water droplets. The more water droplets on the mulch film of Comparative Example 10 not only prevent sunlight from entering the mulch film space, and the evaporation of water droplets also absorbs more sunlight energy, so the soil temperature of the mulch film of Comparative Example 10 (12 o'clock in the daytime is 13.4 ℃, at night 2 11.1°C) was also much lower than the soil temperature of the mulch film in Example 4.

As far as Comparative Example 11 is concerned, the results in Table 1 show that the soil temperature covered by the plastic film of Comparative Example 11 is 12°C at 12:00 during the day and 9.6°C at 2:00 at night, which are far lower than those covered by the plastic film in Example 4. soil temperature. The results in Table 4 show that the number of water droplets formed on the mulch film of Comparative Example 11 reached 29, and the contact angle of the hydrophilic layer was 86°, which was much higher than the 0 water droplets formed on the mulch film of Example 4 and the hydrophilic layer. The contact angle is 4°. This is because the difference between the mulch film of Comparative Example 11 and the mulch film of Example 4 is that there is no chlorosulfonated polyethylene in the ventilation layer and the hydrophilic layer, and the chlorosulfonated polyethylene has good adhesion, which can make each coating layer They are effectively compatible and bonded together, while Comparative Example 11 does not use chlorosulfonated polyethylene, which results in that the adhesion of the ventilation layer on the mask layer is not very good, and the gap between the ventilation layer and the mask layer is Larger pores are generated, which makes it easy for cold air outside the mulch to enter into the mulch space through the gaps, thereby reducing the soil temperature too quickly. In addition, the hydrophilic layer of Comparative Example 11 did not use chlorosulfonated polyethylene, so that the adhesion of the hydrophilic layer on the surface of the ventilation layer was not very good, causing part of the hydrophilic layer to fall off and the hydrophilicity of the hydrophilic layer to decrease. , so there are more water droplets on the mulch film of Comparative Example 11.

As far as Comparative Example 12 is concerned, the results in Table 1 show that the soil temperature covered by the mulch film prepared in Comparative Example 12 is 11.9°C at 12:00 during the day and 9.8°C at 2:00 at night, which are far lower than those of Example 4. Soil temperature covered by mulch. This is because the mulch film prepared in Comparative Example 12 is black and opaque, and sunlight is not easy to directly penetrate the mulch film to heat the space and soil covered by the mulch film, resulting in a slow temperature rise of the soil, especially in winter, at 12 o'clock in the daytime, when the sun is at its highest during the day However, the comparative example 12 failed to effectively use the sunlight energy during this period to rapidly increase the soil temperature, and also because the soil failed to absorb and store enough heat during the day when the sunlight was the most abundant, so the comparative implementation was carried out at night. The temperature of the soil covered by the mulch film in Example 12 was also lower. The results in Table 2 show that the carbon dioxide concentration in the space covered by the plastic film of Comparative Example 12 is 230 ppm at 12:00 during the day, which is far lower than the concentration of 300 ppm required for crop photosynthesis; in addition, the ammonia gas in the space covered by the plastic film of Comparative Example 12 The concentration of 5.1ppm is also much higher than the ammonia concentration in the space covered by the mulch film in implementation 4. This may be because the intermediate layer of Comparative Example 12 did not use the butyl acrylate and styrene monomers as in Example 4, and did not use the initiator-loaded negative heat material, which resulted in no formation on the surface of the negative heat material particles. Dense and rigid polymer shell, which leads to the expansion or contraction of the negative heat material particles, the polymer matrix around the negative heat material particles also expands or contracts due to excessive elasticity, making the negative heat material particles and the polymer The pores between the substrates may be too small, which causes the film of Comparative Example 12 to lose the effect of temperature regulation of pore size and ventilation to a certain extent, and finally makes it difficult to supplement the _CO2 in the fresh air from the outside to the area covered by the film of Comparative Example 12. The NH ₃ in the space and in the space covered by the mulch film of Comparative Example 12 is difficult to be exchanged to the outside of the mulch film in time. The results in Table 4 show that the number of water droplets on the mulch film in Comparative Example 12 reached 62, and its contact angle toward the soil surface was 121°, which was much higher than that of the mulch film prepared in Example 4. There were 0 water droplets and hydrophilic The contact angle of the layer is 4°. This is because the upper and lower layers of the mulch film in Comparative Example 12 are made of polyethylene hydrophobic polymer material, and the mulch film made of this material is prone to water droplets. These water droplets prevent direct sunlight from entering the space covered by the mulch film, and at the same time, the evaporation of these water droplets also absorbs water droplets. A large amount of thermal energy is also an important factor leading to the lower temperature of the soil covered by the mulch film in Comparative Example 12.

Table 1 The average temperature of the soil covered by the mulch film obtained in Example 1, Example 4, Example 5, and Comparative Examples 6-12 at a depth of 5 cm, and the average temperature of the environment outside the mulch film at 12:00 during the day is 16.4 ℃ , the average ambient temperature outside the plastic film at 2:00 at night is 6.8 ℃

Table 2 Example 1, Example 4, Example 5, and Comparative Examples 6 to 12 obtained the average concentration of CO ₂ gas in the space covered by the mulch film, and the average concentration of CO ₂ gas in the environment outside the mulch film was 400ppm

Table 3 Example 1, Example 4, Example 5, and Comparative Examples 6 to 12 obtained the average concentration of NH ₃ gas in the space covered by the mulch film, and the average concentration of NH ₃ gas in the environment outside the mulch film was 0ppm

Table 4 The average number of water droplets formed on the mulch film obtained in Example 1, Example 4, Example 5, and Comparative Examples 6-12 on an area of 0.1 m × 0.1 m and their contact angles toward the soil surface

Claims (8)

1. The utility model provides a ventilative waterless drop plastic film, its characterized in that, the plastic film sets gradually facial mask layer (1) from top to bottom, but temperature regulation's layer of taking a breath (2) and hydrophilic layer (3), the facial mask layer distribute bleeder vent (11), but temperature regulation's layer of taking a breath by compound negative heat material of butyl acrylate-styrene-chlorosulfonated polyethylene copolymer constitute, negative heat material (21) are ZrW of load benzoyl peroxide₂O₈The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 20-35 parts of butyl acrylate, 2-7 parts of styrene and 1.5 parts of chlorosulfonated polyethylene6.5 parts of a negative thermal material, 3-8 parts of a negative thermal material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, 1-5 parts of chlorosulfonated polyethylene and 20-40 parts of polyvinyl alcohol; the preparation method of the breathable water-drop-free 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 solution A, and then dissolving 30 parts by weight of ZrW with particle size of 100-32 meshes₂O₈Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW₂O₈Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide₂O₈Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide₂O₈0.1-0.12% of the total weight of the negative thermal material;

(2) dissolving 1.5-6.5 parts by weight of chlorosulfonated polyethylene in 2-7 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding sodium dodecyl sulfate, OP-10 emulsifier and deionized water into the solution B, and stirring for 30min at room temperature at the rotation speed of 350-;

(3) heating a container containing the emulsion D in a water bath to a certain temperature, and then obtaining the benzoyl peroxide-loaded ZrW from the solution obtained in the step (1)₂O₈Taking out 3-8 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dripping 20-35 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dripping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(4) after the butyl 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 stirring speed for reaction 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 white emulsion E;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.1-0.3mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 20-40 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at room temperature of 360r/min at the rotating speed of 350-;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 15-30 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; 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 white emulsion I;

(9) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.08-0.2mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer;

the breathable water-drop-free mulching film can be obtained through the steps (1) to (9).

2. The breathable water-drop-free mulching film of claim 1, wherein the breathable water-drop-free mulching filmCharacterized in that the material of the mask layer is polyethylene or polyvinyl chloride, the pore size of the air holes distributed on the mask layer is 0.5-3mm, and the distribution density of the air holes is 5-20 per m²。

3. The breathable water-drop-free mulching film according to claim 1, wherein the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material comprises the following components in parts by weight: 32 parts of butyl acrylate, 6 parts of styrene, 5 parts of chlorosulfonated polyethylene and 4 parts of negative thermal material.

4. The breathable water-drop-free mulching film according to claim 1, wherein the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 19 parts of hydroxypropyl acrylate, 2 parts of styrene, 2 parts of chlorosulfonated polyethylene and 25 parts of polyvinyl alcohol.

5. The breathable waterless mulching film of claim 1, wherein in step (2) is prepared 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water.

6. The breathable moisture-free mulching film according to claim 1, wherein the temperature to which the container of the emulsion D in the preparation step (3) is heated in the water bath is 82 ℃.

7. The breathable moisture-free mulching film according to claim 1, wherein the temperature of the reaction system is raised to 85 ℃ after the addition of the butyl acrylate and the solution C in the step (3) in the preparation step (4) is finished.

8. The air-permeable waterless mulching film according to claim 1, wherein said constant temperature stirring in preparation step (4) is performed for 5 hours at a stirring speed of 250 r/min.

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