Multilayer inner additive long-acting drip agricultural film and preparation method thereof

Abstract

The application relates to the technical field of facility horticulture covering agricultural shed film, and discloses a multi-layer inner adding type long-acting flow-dripping agricultural film and a preparation method thereof, which comprises an outer film, a middle film and an inner film; the outer film comprises resin 42-100 parts and functional masterbatch 10-25 parts; the middle film is arranged on one side of the outer film and comprises resin 75-85 parts and flow-dripping masterbatch A 15-25 parts; the inner film is arranged on the side, opposite to the outer film, of the middle film and comprises resin 75-90 parts and flow-dripping masterbatch B 10-25 parts; and the number of layers of the middle film is greater than or equal to 1. When the application is used, the borate flow-dripping agent is arranged in the inner layer, and the traditional flow-dripping agent is arranged in the middle layer, so that the combined effect of multiple flow-dripping agents is achieved, and the problem that a single flow-dripping agent cannot be compatible in the effective period and low-temperature resistance is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of agricultural greenhouse film technology for facility horticulture covering, and in particular to a multi-layer internally added long-lasting anti-drip agricultural film and its preparation method. Background Technology

[0002] In winter, the large temperature difference between the inside and outside of greenhouses causes the resulting fog to condense into a layer of fine water droplets on the surface of the greenhouse film. Since greenhouses are mostly made of polyolefin materials, which are hydrophobic, the water droplets cannot spread on the film surface, directly affecting the greenhouse's light conditions and hindering crop yield and quality. In the mid-to-late 1990s, the introduction of anti-drip agents solved this problem. However, the effective period of domestically produced internally added anti-drip agents is generally only 3-6 months, and while the effect is obvious in the initial stages, the anti-drip agent gradually dissipates and loses its function under continuous water rinsing. Furthermore, due to its small molecular weight, it precipitates quickly in the film, resulting in a short anti-drip period, requiring the greenhouse to be opened and closed again after about six months, leading to high personnel and material costs.

[0003] On the other hand, borate ester-based anti-dripping agents are organic boron surfactants with novel structures that have been developed in recent years. As anti-dripping agents, they have significant anti-dripping effects and long-lasting effects that are significantly better than ordinary domestic anti-dripping agents. They have reached or exceeded the level of imported anti-dripping agents from Japan. Compared with traditional anti-dripping agents, they have a faster precipitation rate, but they are not easy to precipitate at low temperatures, have a higher haze value, and have limited application environments, which restricts the widespread application of this advantageous anti-dripping agent.

[0004] In summary, traditional anti-drip agents in China are prone to precipitation and have good high / low temperature resistance, but their anti-drip effect is short-lived; newer anti-drip agents, such as borate esters, have a long-lasting effect but poor low-temperature resistance. To achieve long-lasting anti-drip properties in greenhouse films and address the incompatibility between the long-lasting effect and low-temperature resistance of single anti-drip agents, this invention provides a multi-layer, internally added long-lasting anti-drip agricultural film that leverages the combined effect of anti-drip agents. Summary of the Invention

[0005] In view of this, the present invention provides a multi-layer internally added long-lasting anti-drip agricultural film and its preparation method, so as to solve the technical problem that the single anti-drip agent in the existing agricultural film cannot be compatible with long-lasting effect and good low-temperature resistance.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a multi-layer internally added long-lasting anti-drip agricultural film, comprising an outer film, a middle film, and an inner film; wherein,

[0008] The outer film comprises 42-100 parts of resin and 10-25 parts of functional masterbatch; the middle film is disposed on one side of the outer film and comprises 75-85 parts of resin and 15-25 parts of anti-drip masterbatch A; the inner film is disposed on the opposite side of the middle film to the outer film and comprises 75-90 parts of resin and 10-25 parts of anti-drip masterbatch B.

[0009] Preferably, in the above-mentioned multi-layer internally added long-lasting drip-resistant agricultural film, the number of the middle film layers is ≥1.

[0010] Preferably, in the above-mentioned multi-layer internally added long-lasting anti-drip agricultural film, by weight parts, the anti-drip masterbatch A includes 40-80 parts of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts of traditional anti-drip agent, 0.1-10 parts of light stabilizer, 0.5-2 parts of antioxidant, 0.3-1 parts of anti-fogging agent, and 5-10 parts of heat-insulating agent; the anti-drip masterbatch B includes 30-70 parts of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts of borate ester anti-drip agent, 0.1-10 parts of light stabilizer, 1-8 parts of antioxidant, and 5-10 parts of heat-insulating agent.

[0011] Preferably, in the above-mentioned multi-layer internally added long-lasting anti-drip agricultural film, the functional masterbatch includes anti-aging masterbatch, barrier masterbatch, light-converting masterbatch, dust-proof masterbatch, and light-diffusing masterbatch; wherein, the anti-aging masterbatch includes 30-40 parts of low-density polyethylene, 45-60 parts of linear low-density polyethylene, 5-15 parts of light stabilizer, 1-6 parts of antioxidant, and 0.1-1 parts of hydrotalcite acid absorber; the barrier masterbatch includes 15-45 parts of low-density polyethylene, 15-45 parts of linear low-density polyethylene, and 20-50 parts of hydrotalcite. The light-converting masterbatch comprises 10-40 parts of low-density polyethylene, 40-60 parts of linear low-density polyethylene, and 2-10 parts of light-converting agent; the dust-proof masterbatch comprises 60-70 parts of low-density polyethylene, 10-30 parts of linear low-density polyethylene, 2-10 parts of fluoroelastomer, 1-8 parts of stearic acid metal soap, and 1-5 parts of amide dust-proofing agent; the light-diffusing masterbatch comprises 10-20 parts of low-density polyethylene, 60-70 parts of linear low-density polyethylene, 5-20 parts of light-diffusing agent, and 5-15 parts of talc.

[0012] Preferably, in the above-mentioned multi-layer internally added long-lasting anti-drip agricultural film, the borate ester anti-drip agent is any one of 703, 706, 709, and 777.

[0013] Preferably, in the above-mentioned multi-layer internally added long-lasting anti-drip agricultural film, the traditional anti-drip agent component is a fatty acid polyol ester.

[0014] Preferably, in the above-mentioned multilayer internally added long-lasting anti-drip agricultural film, the antioxidant is one of amine antioxidants, phenolic antioxidants, and phosphite antioxidants; and the light stabilizer is a hindered amine light stabilizer.

[0015] Preferably, in the above-mentioned multi-layer internally added long-lasting anti-drip agricultural film, the thickness ratio of the outer film, the middle film, and the inner film is 1:1:1 or 1:1.5:1; the sum of the thicknesses of the middle film and the inner film accounts for more than 70% of the total thickness of the agricultural film.

[0016] Preferably, the present invention also provides a method for preparing a multi-layer internally added long-lasting anti-drip agricultural film, comprising the following steps:

[0017] S1: Add the components of the functional masterbatch to a mixer and stir and mix them. Then granulate the mixture using a single-screw extruder to obtain the functional masterbatch.

[0018] S2: Add the components of the drip masterbatch A into a mixer and stir to mix. Then granulate the mixture through a single screw extruder to obtain drip masterbatch A.

[0019] S3: Add the components of the drip masterbatch B to a mixer and stir to mix. Then granulate the mixture using a single screw extruder to obtain the drip masterbatch B.

[0020] S4: Add functional masterbatch, dripping masterbatch A, dripping masterbatch B and resin to a three-layer co-extruder, wherein dripping masterbatch A is added to the middle extruder and dripping masterbatch B is added to the inner extruder. After melt blow molding, the mixture is cooled, shaped and wound to obtain a multi-layer internal additive long-lasting dripping agricultural film.

[0021] Preferably, in the above-mentioned method for preparing multilayer internally added long-lasting drip-proof agricultural film, the resin in step S4 is one or a mixture of several of polyethylene and ethylene-vinyl acetate copolymer (EVA).

[0022] Preferably, in the above-mentioned method for preparing the multi-layer internally added long-lasting anti-drip agricultural film, the light transmittance of the multi-layer internally added long-lasting anti-drip agricultural film is 88-91%, and the haze is 15-20%; under high temperature conditions, the initial dripping time is 180-220s, the time for white dripping to appear is 10-18 days, and the anti-drip failure time is 15-39 days, in accordance with the testing standard GB / T20202-2019. Under low temperature conditions, the anti-drip effect lasts for 6-12 days.

[0023] This invention provides a multi-layer internally added long-lasting anti-drip agricultural film, which has the following advantages compared with the prior art:

[0024] (1) This invention sets up a multi-layered middle film, adds borate ester anti-drip agents to the inner film, and adds traditional anti-drip agents to the multi-layered middle film, giving full play to the combined effect of anti-drip agents and achieving long-lasting anti-drip properties of agricultural film. At the same time, when the precipitation of anti-drip agents in the inner layer decreases or the precipitation at low temperature is poor, anti-drip agents can be provided to the inner layer in a stepwise manner, which is conducive to maintaining the continuity of anti-drip properties and low-temperature resistance of greenhouse film. It solves the problem that single anti-drip agents cannot be compatible in terms of duration of effect and low-temperature resistance, and also solves the problem of poor haze within a certain range. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the multi-layer internally added long-lasting drip-proof agricultural film of the present invention.

[0027] In the figure, 100 represents the outer film; 200 represents the middle film; and 300 represents the inner film. Detailed Implementation

[0028] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0029] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] like Figure 1 As shown, the present invention provides a multi-layer internally added long-lasting anti-drip agricultural film, comprising an outer film 100, a middle film 200 and an inner film 300.

[0033] In some embodiments of the present invention, the outer film 100 is the outermost layer of the agricultural film, comprising 2-20 parts of low-density polyethylene, 40-80 parts of linear low-density polyethylene, and 10-25 parts of functional masterbatch, and has functions such as waterproofing, dustproofing, UV protection, and windproofing. The middle film 200 is disposed on one side of the outer film 100 and comprises 75-85 parts of ethylene-vinyl acetate copolymer (EVA) resin and 15-25 parts of anti-drip masterbatch A. The inner film 300 is disposed on the middle film 200. The outer film 100 is located on the opposite side of the film 100 and contains 75-90 parts of ethylene-vinyl acetate copolymer (EVA) resin and 10-25 parts of anti-dripping masterbatch B. The anti-dripping masterbatch A contains a traditional anti-dripping agent and has good high / low temperature resistance. The anti-dripping masterbatch B contains a borate ester anti-dripping agent and has good anti-dripping retention. The combination of multiple anti-dripping agents solves the problem of incompatibility between single anti-dripping agents in terms of retention period and low temperature resistance, which is conducive to achieving long-term anti-dripping properties of the greenhouse film.

[0034] In some embodiments of the present invention, the number of layers of the middle film 200 is ≥1, and different types and functions of anti-drip agents can be added to each layer, which is beneficial to the combination of multiple anti-drip agents, giving full play to the combined effect of anti-drip agents, and solving the problem that a single anti-drip agent cannot be compatible with long-lasting effect and good low-temperature resistance.

[0035] In some embodiments of the present invention, the anti-drip agent in the inner film 300 is directly precipitated, which can prevent water droplets from forming on the surface of the agricultural film. When the anti-drip agent in the inner film 300 decreases or the precipitation effect deteriorates, the anti-drip agent in the multilayer middle film 200 can provide anti-drip agent to the inner film 300 in a stepwise manner through the movement between molecules, so as to maintain the continuity of the anti-drip properties of the greenhouse film. At the same time, since the borate ester anti-drip agent in the inner film 300 has good anti-drip retention, it is more conducive to achieving long-term anti-drip properties of the agricultural film.

[0036] In some embodiments of the present invention, by weight, the anti-dripping masterbatch A comprises 40-80 parts, preferably 60-70 parts, of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts, preferably 16-25 parts, of a conventional anti-dripping agent, 0.1-10 parts, preferably 5-7 parts, of a light stabilizer, 0.5-2 parts, preferably 0.8-1.5 parts, of an antioxidant, 0.3-1 part, preferably 0.6-0.9 parts, of an anti-fogging agent, and 5-10 parts, preferably 8-9 parts, of a heat-insulating agent.

[0037] In some embodiments of the present invention, by weight, the anti-dripping masterbatch B comprises 30-70 parts, preferably 50-60 parts, of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts, preferably 20-25 parts, of borate ester anti-dripping agent, 0.1-10 parts, preferably 5-7 parts, of light stabilizer, 1-8 parts, preferably 1-3 parts, of antioxidant, and 5-10 parts, preferably 6-8 parts, of heat-insulating agent.

[0038] In some embodiments of the present invention, the functional masterbatch includes anti-aging masterbatch, barrier masterbatch, light conversion masterbatch, dustproof masterbatch, and light diffusion masterbatch.

[0039] In some embodiments of the present invention, by weight, the anti-aging masterbatch includes 30-40 parts of low-density polyethylene, preferably 35-40 parts, 45-60 parts of linear low-density polyethylene, preferably 50-55 parts, 5-15 parts of light stabilizer, preferably 12-14 parts, 1-6 parts of antioxidant, preferably 3-5 parts, and 0.1-1 parts of hydrotalcite acid absorber, preferably 0.5-1 parts; the barrier masterbatch includes 15-45 parts of low-density polyethylene, preferably 20-35 parts, 15-45 parts of linear low-density polyethylene, preferably 25-35 parts, and 20-50 parts of hydrotalcite, preferably 30-40 parts; the light conversion masterbatch includes 10-40 parts of low-density polyethylene, preferably 25-35 parts, and 10-40 parts of linear low-density polyethylene, preferably 25-35 parts, and 20-50 parts of hydrotalcite, preferably 30-40 parts; The masterbatch comprises 40-60 parts of low-density polyethylene, preferably 35-55 parts, and 2-10 parts of light-converting agent, preferably 6-8 parts; the dust-proof masterbatch comprises 60-70 parts of low-density polyethylene, preferably 65-70 parts, 10-30 parts of linear low-density polyethylene, preferably 25-30 parts, 2-10 parts of fluoroelastomer, preferably 6-9 parts, 1-8 parts of stearic acid metal soap, preferably 5-7 parts, and 1-5 parts of amide dust-proofing agent, preferably 2-4 parts; the light-diffusing masterbatch comprises 10-20 parts of low-density polyethylene, preferably 14-17 parts, 60-70 parts of linear low-density polyethylene, preferably 65-70 parts, 5-20 parts of light-diffusing agent, preferably 10-15 parts, and 5-15 parts of talc, preferably 13-15 parts.

[0040] In some embodiments of the present invention, the thickness ratio of the outer film 100, the middle film 200, and the inner film 300 is 1:1:1 or 1:1.5:1, preferably 1:1.5:1, and the sum of the thicknesses of the middle film 200 and the inner film 300 accounts for more than 70% of the total thickness of the agricultural film.

[0041] In some embodiments of the present invention, the borate ester dripping agent is any one of 703, 706, 709, and 777, preferably 706 or 777; the conventional dripping agent is a fatty acid polyol ester, which can be "KF650" manufactured by Riken Co., Ltd. of Japan or "LY-10" manufactured by Lin'an Additives Chemical Co., Ltd.

[0042] In some embodiments of the present invention, the antioxidant is one of amine antioxidants, phenolic antioxidants, and phosphite antioxidants. It can be one of triethyl phosphite, pyrogallolate, stannous phosphate, tris(2,4-di-tert-butylphenyl) phosphite, thiodioctanoate, dioctanoate disulfide, and bis(2,2,6,6-tetramethyl-4-piperidinyl)formamide, preferably triethyl phosphite and tris(2,4-di-tert-butylphenyl) phosphite, more preferably triethyl phosphite. This maintains the softness, extensibility, and stability of the agricultural film material, extends the service life of the agricultural film, and ensures that the agricultural film has good physical properties during use, meeting the needs of agricultural production.

[0043] In some embodiments of the present invention, the light stabilizer is a hindered amine light stabilizer, which may be a polymer of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol (trade name 622), poly[[6-[(1,1,3,3-tetramethylbutyl)amino]triazine-2,4-di][[(2,2,6,6-tetramethyl-4-piperidinyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]] (trade name 944), or a polymer of N,N'-bis(2,2,6,6-tetramethyl-4-pyridyl)-1,6-hexanediamine with 2,4-dichloro-6-(4-morpholinyl)-1,3,5-triazine (trade name 3346).

[0044] In some embodiments of the present invention, the preparation method of multilayer internally added long-lasting anti-drip agricultural film includes the following steps:

[0045] S1: Add each component of the functional masterbatch to a mixer at a temperature of 130-160℃ and stir and mix. Then granulate the mixture through a single screw extruder at a temperature of 105-145℃ to obtain the functional masterbatch.

[0046] S2: Add each component of the drip masterbatch A to a mixer at a temperature of 150-170℃ and stir and mix. Then granulate the mixture through a single screw extruder at a temperature of 115-160℃ to obtain drip masterbatch A.

[0047] S3: Add each component of the drip masterbatch B to a mixer at a temperature of 150-170℃ and stir and mix. Then granulate the mixture through a single screw extruder at a temperature of 115-160℃ to obtain drip masterbatch B.

[0048] S4: Add functional masterbatch, dripping masterbatch A, dripping masterbatch B and resin to a three-layer co-extruder, wherein dripping masterbatch A is added to the middle extruder and dripping masterbatch B is added to the inner extruder. After melt blow molding, the mixture is cooled, shaped and wound to obtain a multi-layer internal additive long-lasting dripping agricultural film.

[0049] In some embodiments of the present invention, in step S4, the resin is one or a mixture of polyethylene and polyvinyl acetate, preferably a mixture of polyethylene and polyvinyl acetate, ethylene-vinyl acetate copolymer (EVA).

[0050] In some embodiments of the present invention, the light transmittance of the multi-layer internally additive long-lasting anti-drip agricultural film, tested according to the GB / T20202-2019 test standard, is 88-91%, and the haze is 15-20%. Under high temperature conditions, the initial dripping time is 180-220 seconds, the time for white dripping to appear is 10-18 days, and the anti-drip failure time is 15-39 days, all in accordance with the GB / T20202-2019 test standard. Under low temperature conditions, the anti-drip effect lasts for 6-12 days. The effective period of the multi-layer internally additive long-lasting anti-drip agricultural film is extended by 3-6 months.

[0051] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] The multi-layer internal additive long-lasting anti-drip agricultural film adopts a three-layer co-extrusion blow molding process. The resins, functional masterbatches, and anti-drip masterbatches used in each layer are selected according to the following requirements. The functional masterbatches include anti-aging masterbatch, barrier masterbatch, light conversion masterbatch, dustproof masterbatch, and light diffusion masterbatch.

[0054] Preparation of anti-aging masterbatch:

[0055] 38 parts of low-density polyethylene, 50 parts of linear low-density polyethylene, 13 parts of light stabilizer, 4 parts of antioxidant, and 0.7 parts of hydrotalcite acid absorber were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain the anti-aging masterbatch. The mixing mill temperature was 130-160℃, and the single-screw granulator temperature was 105-145℃.

[0056] Preparation of barrier masterbatch:

[0057] 30 parts of low-density polyethylene, 30 parts of linear low-density polyethylene, and 35 parts of hydrotalcite were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain barrier masterbatch. The Banbury mixer temperature was 140-160℃, and the single-screw granulator temperature was 110-145℃.

[0058] Preparation of optical conversion masterbatch:

[0059] 30 parts of low-density polyethylene, 45 parts of linear low-density polyethylene, and 7 parts of a brightening agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain the brightening masterbatch. The Banbury mixer temperature was 140-150℃, and the single-screw granulator temperature was 105-145℃.

[0060] Preparation of dustproof masterbatch:

[0061] 68 parts of low-density polyethylene, 28 parts of linear low-density polyethylene, 8 parts of fluoroelastomer, 6 parts of stearic acid metal soap, and 3 parts of amide dust repellent were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain dust repellent masterbatch. The mixing mill temperature was 130-150℃, and the single-screw granulator temperature was 110-135℃.

[0062] Preparation of astigmatism masterbatch:

[0063] 15 parts of low-density polyethylene, 68 parts of linear low-density polyethylene, 13 parts of light-diffusing agent, and 14 parts of talc powder were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain light-diffusing masterbatch. The mixing mill temperature was 130-160℃, and the single-screw granulator temperature was 120-145℃.

[0064] Preparation of droplet masterbatch A:

[0065] 65 parts of ethylene-vinyl acetate copolymer (EVA) resin, 20 parts of traditional anti-dripping agent, 6 parts of light stabilizer, 1.5 parts of antioxidant, 0.8 parts of anti-fogging agent, and 8.5 parts of heat-insulating agent were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The mixing mill temperature was 160-170℃, and the single-screw extruder temperature was 130-160℃.

[0066] Preparation of droplet masterbatch B:

[0067] 55 parts of ethylene-vinyl acetate copolymer (EVA) resin, 70623 parts of borate ester anti-dripping agent, 6 parts of light stabilizer, 2 parts of antioxidant, and 7 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch A. The Banbury mixer temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0068] 15 parts of the prepared functional masterbatch, 20 parts of dripping masterbatch A, 15 parts of dripping masterbatch B, and 85 parts of EVA were added to a three-layer co-extruder, with dripping masterbatch A fed into the middle layer extruder and dripping masterbatch B fed into the inner layer extruder. After melt blow molding, the mixture was cooled, shaped, and wound to obtain a multi-layer internally additive long-lasting dripping agricultural film. The outer layer extruder temperature was 180-190℃, the inner and middle layer extruder temperatures were 140-150℃, the die temperature was 200℃, the blow-up ratio was 1.7-2.5, the draw ratio was 4-6, and the plasticizing time was 10-25 minutes.

[0069] Example 2

[0070] The difference between this embodiment and Embodiment 1 is that:

[0071] Preparation of droplet masterbatch B:

[0072] 55 parts of ethylene-vinyl acetate copolymer (EVA) resin, 70923 parts of borate ester anti-dripping agent, 6 parts of light stabilizer, 2 parts of antioxidant, and 7 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The Banbury mixer temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0073] Example 3

[0074] The difference between this embodiment and Embodiment 1 is that:

[0075] Preparation of droplet masterbatch B:

[0076] 55 parts of ethylene-vinyl acetate copolymer (EVA) resin, 77,723 parts of borate ester anti-dripping agent, 6 parts of light stabilizer, 2 parts of antioxidant, and 7 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The Banbury mixer temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0077] Example 4

[0078] The difference between this embodiment and Embodiment 1 is that:

[0079] Preparation of droplet masterbatch A:

[0080] 40 parts of ethylene-vinyl acetate copolymer (EVA) resin, 15 parts of traditional anti-dripping agent, 0.1 parts of light stabilizer, 0.5 parts of antioxidant, 0.3 parts of anti-fogging agent, and 5 parts of heat-insulating agent were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch A. The mixing mill temperature was 160-170℃, and the single-screw extruder temperature was 130-160℃.

[0081] Preparation of droplet masterbatch B:

[0082] 30 parts of ethylene-vinyl acetate copolymer (EVA) resin, 70615 parts of borate ester anti-dripping agent, 0.1 parts of light stabilizer, 1 part of antioxidant, and 5 parts of heat-insulating agent were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The mixing mill temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0083] Example 5

[0084] The difference between this embodiment and Embodiment 1 is that:

[0085] Preparation of droplet masterbatch A:

[0086] 80 parts of ethylene-vinyl acetate copolymer (EVA) resin, 30 parts of traditional anti-dripping agent, 10 parts of light stabilizer, 2 parts of antioxidant, 1 part of anti-fogging agent, and 10 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch A. The Banbury mixer temperature was 160-170℃, and the single-screw extruder temperature was 130-160℃.

[0087] Preparation of droplet masterbatch B:

[0088] 70 parts of ethylene-vinyl acetate copolymer (EVA) resin, 70-630 parts of borate ester anti-dripping agent, 10 parts of light stabilizer, 8 parts of antioxidant, and 10 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The Banbury mixer temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0089] Comparative Example 1

[0090] The difference between this comparative example and Example 1 is as follows:

[0091] Preparation of droplet masterbatch B:

[0092] 55 parts of ethylene-vinyl acetate copolymer (EVA) resin, 23 parts of traditional anti-dripping agent 706, 6 parts of light stabilizer, 2 parts of antioxidant, and 7 parts of heat-insulating agent were added to a Banbury mixer and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch B. The Banbury mixer temperature was 150-170℃, and the single-screw extruder temperature was 115-160℃.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is as follows:

[0095] Preparation of droplet masterbatch A:

[0096] 65 parts of ethylene-vinyl acetate copolymer (EVA) resin, 70-920 parts of borate ester anti-dripping agent, 6 parts of light stabilizer, 1.5 parts of antioxidant, 0.8 parts of anti-fogging agent, and 8.5 parts of heat-insulating agent were added to a mixing mill and stirred. The mixture was then granulated using a single-screw extruder to obtain anti-dripping masterbatch A. The mixing mill temperature was 160-170℃, and the single-screw extruder temperature was 130-160℃.

[0097] The prepared multi-layer internally added long-lasting anti-drip agricultural film was tested for optical performance and anti-drip performance under high temperature conditions according to GB / T20202-2019 standard, as shown in Table 1 below.

[0098] Table 1

[0099]

[0100]

[0101] As shown in Table 1, the multi-layer internally added long-lasting anti-drip agricultural films of Examples 1-5 of the present invention have a relatively long anti-drip effect period, while the anti-drip effect period of the agricultural film of Comparative Example 1 is relatively short. Furthermore, the light transmittance and haze of Examples 1-5 have reached the same or higher standards as Comparative Example 1, indicating that the multi-layer internally added long-lasting anti-drip agricultural film of the present invention has good anti-drip effect performance and good light transmittance and haze.

[0102] The low-temperature performance and duration of the prepared multi-layer internally added long-lasting drip-resistant agricultural film were tested, as shown in Table 2 below.

[0103] Table 2

[0104]

[0105] As shown in Table 2, the multilayer internally added long-lasting anti-drip agricultural film prepared by the combination of borate ester anti-drip agent and traditional anti-drip agent in Examples 1-5 has a longer low-temperature retention period. This invention achieves complementary advantages through the combination of anti-drip agents and solves the problems of short retention periods and poor low-temperature precipitation of the two anti-drip agents at high / low temperatures, respectively. Therefore, the multilayer internally added long-lasting anti-drip agricultural film prepared by this invention using a combination of borate ester anti-drip agent and traditional anti-drip agent can extend the anti-drip agent's failure time by 3-6 months in practical applications, thereby extending the service life of the agricultural film and reducing usage costs.

[0106] As can be seen from the above embodiments, the present invention provides a multi-layer internally added long-lasting drip-proof agricultural film and its preparation method.

[0107] In summary, the multi-layer internally added long-lasting anti-drip agricultural film of the present invention leverages the combined effect of multiple anti-drip agents. The addition of borate ester anti-drip agents prolongs the duration of the anti-drip effect of the film, while traditional anti-drip agents also improve the film's resistance to low-temperature anti-drip properties. Furthermore, the multi-layer internally added long-lasting anti-drip agricultural film of the present invention also exhibits good light transmittance and haze. Compared with existing technologies, the multi-layer internally added long-lasting anti-drip agricultural film prepared by the present invention solves the problem of incompatibility between the duration of effectiveness and low-temperature resistance of a single anti-drip agent, significantly extending the film's duration of effectiveness.

[0108] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0109] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A multi-layer internally added long-lasting anti-drip agricultural film, characterized in that, By weight, including: The outer film comprises 42-100 parts of resin and 10-25 parts of functional masterbatch; The middle layer film is disposed on one side of the outer layer film and contains 75-85 parts of resin and 15-25 parts of anti-drip masterbatch A; The inner film is disposed on the side of the middle film opposite to the outer film, and contains 75-90 parts of resin and 10-25 parts of anti-drip masterbatch B. The number of intermediate film layers is ≥1; By weight parts The anti-dripping masterbatch A comprises 40-80 parts of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts of traditional anti-dripping agent, 0.1-10 parts of light stabilizer, 0.5-2 parts of antioxidant, 0.3-1 part of anti-fogging agent, and 5-10 parts of heat-insulating agent; The dripping masterbatch B comprises 30-70 parts of ethylene-vinyl acetate copolymer (EVA) resin, 15-30 parts of borate ester dripping agent, 0.1-10 parts of light stabilizer, 1-8 parts of antioxidant, and 5-10 parts of heat-insulating agent; The functional masterbatch includes anti-aging masterbatch, barrier masterbatch, light conversion masterbatch, dustproof masterbatch, and light diffusion masterbatch; The anti-aging masterbatch includes 30-40 parts of low-density polyethylene, 45-60 parts of linear low-density polyethylene, 5-15 parts of light stabilizer, 1-6 parts of antioxidant, and 0.1-1 parts of hydrotalcite acid absorber. The barrier masterbatch comprises 15-45 parts of low-density polyethylene, 15-45 parts of linear low-density polyethylene, and 20-50 parts of hydrotalcite. The light conversion masterbatch comprises 10-40 parts of low-density polyethylene, 40-60 parts of linear low-density polyethylene, and 2-10 parts of light conversion agent. The dustproof masterbatch includes 60-70 parts of low-density polyethylene, 10-30 parts of linear low-density polyethylene, 2-10 parts of fluoroelastomer, 1-8 parts of stearic acid metal soap, and 1-5 parts of amide dustproof agent. The light-diffusing masterbatch comprises 10-20 parts of low-density polyethylene, 60-70 parts of linear low-density polyethylene, 5-20 parts of light-diffusing agent, and 5-15 parts of talc. The borate ester dripping agent is any one of 703, 706, 709, and 777; The traditional dripping agent is composed of fatty acid polyol esters.

2. The multi-layer internally added long-lasting anti-drip agricultural film according to claim 1, characterized in that, The antioxidant is one of amine antioxidants, phenolic antioxidants, and phosphite antioxidants; The light stabilizer is a hindered amine light stabilizer.

3. The multi-layer internally added long-lasting anti-drip agricultural film according to claim 1, characterized in that, The thickness ratio of the outer film, the middle film, and the inner film is 1:1:1 or 1:1.5:

1.

4. The method for preparing a multi-layer internally added long-lasting anti-drip agricultural film according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Add the components of the functional masterbatch to a mixer and stir and mix them. Then granulate the mixture through a single screw extruder to obtain the functional masterbatch. S2: Add the components of the drip masterbatch A to a mixer and stir to mix. Then granulate the mixture using a single screw extruder to obtain drip masterbatch A. S3: Add the components of the drip masterbatch B to a mixer and stir to mix. Then granulate the mixture using a single screw extruder to obtain the drip masterbatch B. S4: Add functional masterbatch, dripping masterbatch A, dripping masterbatch B and resin to a three-layer extruder, wherein dripping masterbatch A is added to the middle layer extruder and dripping masterbatch B is added to the inner layer extruder. After melt blow molding, the mixture is cooled, shaped and wound to obtain a multi-layer internal additive long-lasting dripping agricultural film.

5. The method for preparing multi-layer internally added long-lasting anti-drip agricultural film according to claim 4, characterized in that, In step S4, the resin is one or a mixture of several of polyethylene and ethylene vinyl acetate copolymers.

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