Five-layer super-wide heteromaterial co-extrusion film, preparation method and application thereof

Abstract

This invention provides a five-layer ultra-wide heterogeneous material co-extruded film, its preparation method, and its applications. The five-layer ultra-wide heterogeneous material co-extruded film comprises an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, arranged sequentially from the outside to the inside. The outer layer is a polyamide layer; the second outer layer is an adhesive resin layer; the middle layer is a functional polyolefin layer; the second inner layer is an adhesive resin layer; the inner layer is a polyamide layer; and a coating layer is provided on the surface of the outer layer. The five-layer ultra-wide heterogeneous material co-extruded film prepared by this invention exhibits excellent infrared blocking properties, dustproof effect, anti-drip and anti-fogging properties, high tensile strength, good aging and weather resistance, and long service life, and can be applied in agricultural greenhouses and soil fumigation.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and more specifically, to a five-layer ultra-wide heterogeneous material co-extruded film, its preparation method, and its application. The five-layer ultra-wide heterogeneous material co-extruded film has the functions of dust prevention, fog removal, and anti-dripping. Background Technology

[0002] The development of agricultural plastic film in my country began in the mid-to-late 1950s. Currently, more than ten new types of agricultural films have been researched and developed, including aging-resistant, anti-drip, anti-drip and heat-insulating aging-resistant, anti-fogging anti-drip, light-conversion film, high-insulation greenhouse film, and multi-functional film. Agricultural film materials have evolved through the development stages of PVC, PE, and EVA. PVC film has high strength and good heat insulation, making it suitable for cold climates and windy, sandy areas. Except for Northeast, Northwest, North China, and Shandong regions, most other regions use PE and EVA agricultural films. PVC agricultural film production accounts for about 10% of the total agricultural film production, while PE agricultural film production accounts for over 80%. EVA agricultural film is a new type of environmentally friendly agricultural film successfully developed in 1992. In less than 10 years, the annual production of EVA-based composite functional agricultural films has increased significantly, achieving substantial economic and social benefits.

[0003] However, existing agricultural film products generally suffer from problems such as poor infrared blocking, poor dust prevention, low tensile strength, poor aging and weather resistance, and short service life, which are not synchronized with their functions and lifespan, and further improvements are needed. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a five-layer ultra-wide heterogeneous material co-extruded film, its preparation method and application.

[0005] The PA / PE composite agricultural film prepared by this invention can achieve functions such as high light transmittance, hydrophilic inner layer, dustproof outer layer, high heat preservation, long-lasting light conversion, flexibility, and aging resistance, while achieving a service life of ≥5 years.

[0006] This invention addresses the shortcomings of existing technologies by preparing a symmetrical, five-layer, ultra-wide, heterogeneous material co-extruded agricultural film. The film has a width ≥12m, tensile strength (longitudinal and transverse) ≥40MPa, nominal strain at break ≥300%, right-angle tear strength ≥100KN / m, light transmittance ≥89%, haze ≤15%, and after 4000 hours of xenon lamp aging, the longitudinal nominal strain retention rate at break ≥60% (GB / T16422-2014). Its continuous service life is ≥5 years, overcoming the deficiency of inconsistent function and lifespan in existing technologies. The co-extruded agricultural film of this invention exhibits excellent infrared blocking properties, dustproof effect, anti-drip and anti-fogging properties, high tensile strength, good aging and weather resistance, and a long service life.

[0007] One objective of this invention is to provide a five-layer ultra-wide heterogeneous material co-extruded film, comprising an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, arranged sequentially from the outside to the inside; the outer layer is a polyamide layer; the second outer layer is an adhesive resin layer; the middle layer is a functional polyolefin layer; the second inner layer is an adhesive resin layer; the inner layer is a polyamide layer; and a coating layer is provided on the surface of the outer layer.

[0008] With the middle layer as the plane of symmetry, the five-layer heterogeneous material co-extruded agricultural film has a symmetrical structure from the outside to the inside;

[0009] Preferably,

[0010] The width of the five-layer ultra-wide heterogeneous material co-extruded film is ≥12m; and / or,

[0011] The thickness ratios of the outer layer, the second outer layer, the middle layer, the second inner layer, and the inner layer are 15-20%, 15-20%, 20-30%, 15-20%, and 15-20%, respectively; and / or,

[0012] The total thickness of the five-layer ultra-wide heterogeneous co-extruded film is 80–180 μm.

[0013] In a preferred embodiment of the present invention,

[0014] Based on 100 parts by weight of polyamide resin A1, the outer layer and the inner layer are respectively prepared from raw materials comprising the following components:

[0015] Polyamide resin A 1 100 parts by weight;

[0016] Polyamide masterbatch A: 4-10 parts by weight; preferably 5-8 parts by weight;

[0017] Preferably, based on 100 parts by weight of the total weight of polyamide masterbatch A, the polyamide masterbatch A is prepared from raw materials comprising the following components:

[0018]

[0019] In a preferred embodiment of the present invention,

[0020] The polyamide resins A1 and A2 are each independently selected from at least one homopolymer or copolymer of the following polyamides: PA6, PA66, PA12, PA46, PA610, PA612, PA1010; copolymers such as PA6 / PA66 copolymer, etc.; preferably, the polyamide resin is at least one of PA6, PA66, PA6 / PA66 copolymer; and / or,

[0021] The sustained-release agent A is at least one of layered bimetallic hydroxides, preferably at least one of hydrotalcite or hydrotalcite-like compounds; and / or,

[0022] The light stabilizer A is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of a benzophenone compound, a benzotriazole compound, a salicylate compound, a substituted acrylonitrile compound, and a triazine compound; more preferably, the light stabilizer A is at least one of a benzotriazole compound, a triazine compound, and a hindered amine light stabilizer; and / or,

[0023] The antioxidant A is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds, preferably at least one of hindered phenolic compounds and phosphite compounds.

[0024] In a preferred embodiment of the present invention,

[0025] Based on 100 parts by weight of linear low-density polyethylene resin, the outermost layer and the innermost layer are each independently prepared from raw materials comprising the following components:

[0026] 100 parts by weight of linear low-density polyethylene resin;

[0027] 25-45 parts by weight of adhesive resin; preferably 30-40 parts by weight;

[0028] Polyolefin masterbatch B: 10-25 parts by weight; preferably 10-20 parts by weight;

[0029] Preferably, based on 100 parts by weight of polyethylene resin B, the polyolefin masterbatch B is prepared from raw materials comprising the following components:

[0030]

[0031] The polyethylene resin B includes low-density polyethylene resin B and linear low-density polyethylene resin B;

[0032] More preferably, the polyethylene resin comprises:

[0033] Low-density polyethylene resin B: 60-85 parts by weight;

[0034] Linear low-density polyethylene resin B, 15-40 parts by weight;

[0035] More preferably, the polyethylene resin comprises:

[0036] Low-density polyethylene resin B: 65-80 parts by weight;

[0037] Linear low-density polyethylene resin B, 20-35 parts by weight;

[0038] Unless otherwise specified, linear low-density polyethylene in this invention refers to LLDPE, and low-density polyethylene resin refers to LDPE.

[0039] In a preferred embodiment of the present invention,

[0040] Unless otherwise specified, the melt index of the resin in this invention is measured at 190°C and under a load of 2.16 kg.

[0041] The melt flow indexes of the linear low-density polyethylene resin and linear low-density polyethylene resin B are independently selected from 1.0 to 3.0 g / 10 min; and / or,

[0042] The bonding resin is maleic anhydride-grafted low-density polyethylene resin with a melt flow index of 1.0–3.0 g / 10 min; and / or,

[0043] The melt flow index of the low-density polyethylene resin B is 1.0–3.0 g / 10 min; and / or,

[0044] The sustained-release agent B is at least one layered bimetallic hydroxide, preferably at least one of hydrotalcite or hydrotalcite-like compounds; and / or,

[0045] The light stabilizer B is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of a benzophenone compound, a benzotriazole compound, a salicylate compound, a substituted acrylonitrile compound, and a triazine compound; more preferably, the light stabilizer B is at least one of a benzotriazole compound, a triazine compound, and a hindered amine light stabilizer; and / or,

[0046] The antioxidant B is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds, preferably at least one of hindered phenolic compounds and phosphite compounds.

[0047] In a preferred embodiment of the present invention,

[0048] The intermediate layer, based on 100 parts by weight of metallocene polyethylene resin, is prepared from raw materials comprising the following components:

[0049] 100 parts by weight of metallocene polyethylene resin;

[0050] Polyolefin masterbatch #1: 10-25 parts by weight;

[0051] Polyolefin masterbatch #2, 10-25 parts by weight;

[0052] More preferably,

[0053] Based on 100 parts by weight of polyethylene resin C1, the polyolefin masterbatch 1# is prepared from raw materials comprising the following components:

[0054]

[0055] The polyethylene resin C1 includes low-density polyethylene resin C1 and linear low-density polyethylene resin C1;

[0056] More preferably, the polyethylene resin C comprises:

[0057] 60-80 parts by weight of low-density polyethylene resin C1;

[0058] 20-40 parts by weight of linear low-density polyethylene resin C1;

[0059] More preferably, the polyethylene resin C comprises:

[0060] Low-density polyethylene resin C1 65-75 parts by weight;

[0061] 25-35 parts by weight of linear low-density polyethylene resin C1; and / or,

[0062] Based on 100 parts by weight of polyethylene resin C2, the polyolefin masterbatch 2# is prepared from raw materials comprising the following components:

[0063] 100 parts by weight of polyethylene resin C2;

[0064] 5-15 parts by weight of the light-converting agent; preferably 5-10 parts by weight.

[0065] Antioxidant C2: 0.5–5 parts by weight; preferably 2–4 parts by weight;

[0066] The polyethylene resin C2 includes low-density polyethylene resin C2 and linear low-density polyethylene resin C2; more preferably, the polyethylene resin C2 includes:

[0067] Low-density polyethylene resin C2: 35-60 parts by weight;

[0068] 40-65 parts by weight of linear low-density polyethylene resin C2;

[0069] More preferably, the polyethylene resin C2 comprises:

[0070] 40-55 parts by weight of low-density polyethylene resin C2;

[0071] 45-60 parts by weight of linear low-density polyethylene resin C2.

[0072] In a preferred embodiment of the present invention,

[0073] The melt flow index of the metallocene polyethylene resin is 0.5–3.0 g / 10 min; and / or,

[0074] The melt flow indexes of the low-density polyethylene resin C1 and low-density polyethylene resin C2 are independently selected from 1.0 to 3.0 g / 10 min; and / or,

[0075] The melt flow indexes of the linear low-density polyethylene resin C1 and linear low-density polyethylene resin C2 are independently selected from 1.0 to 3.0 g / 10 min; and / or,

[0076] The sustained-release agent C1 is at least one layered bimetallic hydroxide, preferably at least one of hydrotalcite or hydrotalcite-like compounds; and / or,

[0077] The light stabilizer C1 is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of a benzophenone compound, a benzotriazole compound, a salicylate compound, a substituted acrylonitrile compound, and a triazine compound; more preferably, the light stabilizer B is at least one of a benzotriazole compound, a triazine compound, and a hindered amine light stabilizer; and / or,

[0078] The light-converting agent is at least one rare earth organic compound or rare earth inorganic compound; and / or,

[0079] The antioxidant C2 is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds, preferably at least one of hindered phenolic compounds and phosphite compounds.

[0080] In a preferred embodiment of the present invention,

[0081] The coating layer is prepared from raw materials comprising the following components, based on a total weight of 100 parts by weight:

[0082]

[0083] The remainder is water;

[0084] Preferably,

[0085] The emulsion particles of the nano-silica sol have a diameter of 3–15 nm, preferably 6–9 nm; and / or,

[0086] The SiO2 content of the nano-silica sol is 15–30 wt%; and / or,

[0087] The pH value of the nano-silica sol is 9–11; and / or,

[0088] The polyvinyl alcohol resin has a weight-average molecular weight of 120,000 to 180,000, preferably 140,000 to 160,000; and / or,

[0089] The nonionic surfactant may be selected from BASF's Letensol XL series: XL-50, 70, 80; and / or,

[0090] Five layers of ultra-wide heterogeneous material co-extruded film per square meter, wherein the solid content of the coating layer is 0.2–0.3 g / m². 2 .

[0091] The second objective of this invention is to provide a method for preparing a five-layer ultra-wide heterogeneous material co-extruded film, comprising the following steps:

[0092] (1) The raw materials of each layer of the outer layer, the second outer layer, the middle layer, the second inner layer and the inner layer in the specified weight parts are respectively fed into the corresponding hopper of the extrusion screw blow molding machine to obtain a molten mixture;

[0093] (2) The molten mixture obtained in step (1) is simultaneously extruded, and the extruded material is blown through a mold to form a five-layer co-extruded blown film;

[0094] (3) The outer layer of the five-layer co-extruded blown film obtained in step (3) is coated to obtain the five-layer ultra-wide heterogeneous material co-extruded film.

[0095] Preferably,

[0096] In step (1),

[0097] The temperatures of each section of the screw extruder are as follows: the screw temperature connected to the outer and inner hoppers is 225–245°C; the screw temperature connected to the second outer and second inner hoppers is 200–235°C; the screw temperature connected to the middle hopper is 190–220°C; and / or,

[0098] In step (2),

[0099] The extrusion speeds of each hopper of the screw extruder are as follows: the extrusion speed of the molten mixture in the outer and inner layers is 5–10 m / min; the extrusion speed of the molten mixture in the second outer and second inner layers is 5–10 m / min; and the extrusion speed of the molten mixture in the middle layer is 5–10 m / min; and / or,

[0100] The specific conditions for the inflation include: controlling the inflation ratio to be 1.2–2.5; the traction ratio to be 5–7; the inflation pressure to be 0.3–0.6 MPa; and / or,

[0101] In step (3),

[0102] The coating process includes, in sequence, corona treatment, surface coating, and drying.

[0103] More preferably,

[0104] The corona treatment involves applying a corona treatment to the surface of the outer layer of the five-layer co-extruded blown film to achieve a surface energy of 42–48 dynes; and / or,

[0105] The surface coating is achieved by applying the coating layer to the outer surface of a five-layer co-extruded blown film greenhouse film that has undergone corona treatment using a coating machine; and / or...

[0106] The drying process involves drying the coated five-layer co-extruded blown film; more preferably, the drying temperature is 50–70°C; and / or, the linear speed of the conveyor for drying the coating layer is 10–20 m / min.

[0107] The third objective of this invention is to provide an application of a five-layer ultra-wide heterogeneous material co-extruded film in the agricultural field, preferably in agricultural greenhouses and soil fumigation.

[0108] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0109] (1) By utilizing the strong polarity and strong hydrophilicity of PA, placing it in the inner layer of the composite film can maintain the long-term anti-drip and anti-fogging function of agricultural greenhouse film.

[0110] (2) PA has a low coefficient of friction and good self-lubrication. At the same time, the unique nanostructure of the coating layer on the outer layer of PA reduces the contact area and adhesion of dust. When placed on the outer layer of the greenhouse film, it can maintain long-term light transmittance and transparency, and improve the photosynthetic efficiency of crops.

[0111] (3) PA has good heat resistance, which can prevent the back plate effect of the skeleton and extend the service life of agricultural film.

[0112] (4) PA has excellent weather resistance. Adding appropriate antioxidants and co-extruding with PE can effectively extend the service life of agricultural film.

[0113] (5) PA has good oxygen barrier properties, which can protect rare earth light conversion agents from oxidation and degradation, and prolong the light conversion efficiency. Detailed Implementation

[0114] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0115] All raw materials used in the examples are conventional commercially available raw materials.

[0116] Main raw material sources:

[0117] PA6: BASF B3L, melting point 220℃; melt volumetric flow rate, MVR 275 / 5: 110 cm⁻¹ 3 / 10min;

[0118] PA66: BASF A3K, melting point 260℃; melt volumetric flow rate, MVR 275 / 5: 115cm 3 / 10min;

[0119] PA6 / PA66 copolymer: BASF C40L, melting point 189℃; melt volume flow rate, MVR 275 / 5: 100cm 3 / 10min; Ube 5034, melting point 192℃, melt flow rate (190℃ / 2.16kg): 8.0g / 10min;

[0120] Hydrotalcite: CAS: 12304-65-3; Density: 2.0 g / mL; Molecular weight: 182.99; Jiangsu Bost Chemical Technology Co., Ltd.

[0121] HT691: CAS: 42774-15-2, Beijing Huateng New Materials Co., Ltd.;

[0122] Antioxidant 1098: N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, BASF;

[0123] Antioxidant 168: Tris[2,4-di-tert-butylphenyl]phosphite, BASF;

[0124] Linear low-density polyethylene resin: ExxonMobil 1001AV, at 190°C, with a load of 2.16 kg and a melt index of 1.0 g / 10 min;

[0125] Low-density polyethylene resin: ExxonMobil LD100, at 190°C, with a load of 2.16 kg and a melt index of 2.0 g / 10 min;

[0126] Metallocene polyethylene resin: ExxonMobil 2010MA, at 190°C, with a load of 2.16 kg, has a melt index of 1.0 g / 10 min;

[0127] Linear low-density polyethylene resin: ExxonMobil LL6201, at 190℃, with a load of 2.16 kg, has a melt index of 2.5 g / 10 min;

[0128] Light stabilizer 944: Hindered amine light stabilizer HS-944, BASF;

[0129] Nano silica sol: SS3010, Shandong Baite New Materials Co., Ltd.; emulsion particle diameter is 6-9nm, SiO2 content is 25-30wt%, pH value is 9-11;

[0130] Polyvinyl alcohol resin: Kuraray PVA (Japan) 95-88; weight average molecular weight is 150,000 to 160,000.

[0131] Nonionic surfactant: Letensol XL-80, BASF;

[0132] Bonding resin: LyondellBasell PX3060, melt index of 1.6 g / 10 min at 190°C, 2.16 kg load;

[0133] Light conversion agent: Rare earth organic light conversion agent: Europium neodecanoate; Eu (wt%): 8-10%; Hubei Xingyan New Material Technology Co., Ltd.

[0134] The performance test items are as follows:

[0135] Tensile strength and nominal strain at break: The tensile strength and nominal strain at break of the film were tested according to GB / T 1040.1-2006, Test Method for Tensile Properties of Plastics.

[0136] Right-angle tear strength: The right-angle tear strength of the film was tested according to QBT 1130-1991 Test Method for Right-Angle Tear Performance of Plastics;

[0137] Light transmittance: The light transmittance of the film was tested according to GB / T 2410-2008, the method for determining the light transmittance and haze of transparent plastics.

[0138] Haze: The haze of the film was tested according to GB / T 2410-2008 Method for Determination of Light Transmittance and Haze of Transparent Plastics;

[0139] Xenon lamp aging longitudinal fracture nominal strain retention rate: After the cut film is placed in the xenon lamp aging chamber and irradiated for 4000 hours, the nominal strain retention rate of the film at fracture is tested according to GB / T16422-2014.

[0140] In the examples, the number of portions refers to the number of weight portions.

[0141] Example 1

[0142] The symmetrical five-layer ultra-wide heterogeneous material co-extruded agricultural film consists of an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, as shown in Table 1.

[0143] Table 1

[0144]

[0145]

[0146] The preparation process of the above five-layer ultra-wide heterogeneous material co-extruded film:

[0147] According to the components in Table 1, the raw materials for each layer—outer layer, second outer layer, middle layer, second inner layer, and inner layer—are fed into the corresponding hoppers of the extrusion blow molding machine. The temperature of each section of the screw extruder is controlled: the screw temperature connected to the outer and inner layer hoppers is 230–245°C, the screw temperature connected to the second outer and second inner layer hoppers is 220–235°C, and the screw temperature connected to the middle layer hopper is 200–220°C, to obtain a molten mixture.

[0148] By controlling the extrusion speed of each hopper, the molten mixture is extruded simultaneously, and the extruded material is blown by the die to form a five-layer co-extruded blown film. The extrusion speeds of each hopper are as follows: the extrusion speed of the molten mixture of the outer and inner layers is 5 m / min, the extrusion speed of the molten mixture of the second outer and second inner layers is 5 m / min, and the extrusion speed of the molten mixture of the middle layer is 5 m / min. The blown film is specifically controlled as follows: the blown film ratio is 1.7, the traction ratio is 6, and the blowing pressure is 0.5 MPa.

[0149] The surface of the outer layer of the obtained five-layer co-extruded film is subjected to corona treatment to make its surface energy 42-48 dynes. The coating layer in Table 1 is coated on the outer layer surface using a coating machine. After coating, the film is dried. The linear speed of the drying and blowing coating layer is 10-20 m / min. A five-layer ultra-wide heterogeneous material co-extruded film with a width ≥12m and a total thickness of about 100μm is obtained.

[0150] Example 2

[0151] A five-layer ultra-wide heterogeneous material co-extruded agricultural film with a symmetrical structure is composed of an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, as shown in Table 2.

[0152]

[0153]

[0154] The preparation process of the above five-layer ultra-wide heterogeneous material co-extruded film:

[0155] According to the components in Table 2, the raw materials for each layer—outer layer, second outer layer, middle layer, second inner layer, and inner layer—are fed into the corresponding hoppers of the extrusion blow molding machine. The temperature of each section of the screw extruder is controlled: the screw temperature connected to the outer and inner layer hoppers is 235–245°C, the screw temperature connected to the second outer and second inner layer hoppers is 220–235°C, and the screw temperature connected to the middle layer hopper is 200–220°C, to obtain a molten mixture.

[0156] By controlling the extrusion speed of each hopper, the molten mixture is extruded simultaneously, and the extruded material is blown by the die to form a five-layer co-extruded blown film. The extrusion speed of each hopper is as follows: the extrusion speed of the molten mixture of the outer and inner layers is 5 m / min, the extrusion speed of the molten mixture of the second outer and second inner layers is 6 m / min, and the extrusion speed of the molten mixture of the middle layer is 8 m / min. The blown film is specifically controlled as follows: the blown film ratio is 1.7, the traction ratio is 6, and the blowing pressure is 0.5 MPa.

[0157] The surface of the outer layer of the obtained five-layer co-extruded film is subjected to corona treatment to make its surface energy 42-48 dynes. The coating layer in Table 2 is coated on the outer layer surface using a coating machine. After coating, the film is dried. The linear speed of the drying and blowing coating layer is 10-20 m / min to obtain a five-layer ultra-wide heterogeneous material co-extruded film with a width ≥12m and a total thickness of about 100μm.

[0158] Example 3

[0159] The five-layer ultra-wide heterogeneous material co-extruded agricultural film consists of an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, as shown in Table 3.

[0160] Table 3

[0161]

[0162]

[0163] The preparation process of the above five-layer ultra-wide heterogeneous material co-extruded film:

[0164] According to the components in Table 3, the raw materials for each layer—outer layer, second outer layer, middle layer, second inner layer, and inner layer—are fed into the corresponding hoppers of the extrusion blow molding machine. The temperature of each section of the screw extruder is controlled: the screw temperature connected to the outer and inner layer hoppers is 230–245°C; the screw temperature connected to the second outer and second inner layer hoppers is 215–235°C; and the screw temperature connected to the middle layer hopper is 200–220°C, to obtain a molten mixture.

[0165] By controlling the extrusion speed of each hopper, the molten mixture is extruded simultaneously, and the extruded material is blown by the die to form a five-layer co-extruded blown film. The extrusion speeds of each hopper are as follows: the extrusion speed of the molten mixture of the outer and inner layers is 6 m / min, the extrusion speed of the molten mixture of the second outer and second inner layers is 6 m / min, and the extrusion speed of the molten mixture of the middle layer is 6 m / min. The blown film is specifically controlled as follows: the blown film ratio is 1.7, the traction ratio is 7, and the blowing pressure is 0.5 MPa.

[0166] The surface of the outer layer of the obtained five-layer co-extruded film is subjected to corona treatment to make its surface energy 42-48 dynes. The coating layer in Table 3 is coated on the outer layer surface using a coating machine. After coating, the coating layer is dried. The linear speed of the drying and blowing coating layer is 10-20 m / min to obtain a five-layer ultra-wide heterogeneous material co-extruded film with a width ≥12m and a total thickness of about 100μm.

[0167] Example 4

[0168] The five-layer ultra-wide heterogeneous material co-extruded agricultural film consists of an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, as shown in Table 4.

[0169] Table 4

[0170]

[0171]

[0172]

[0173] Preparation process of the above-mentioned five-layer ultra-wide heterogeneous material co-extruded film

[0174] According to the components in Table 4, the raw materials for each layer—outer layer, second outer layer, middle layer, second inner layer, and inner layer—are fed into the corresponding hoppers of the extrusion blow molding machine. The temperature of each section of the screw extruder is controlled: the screw temperature connected to the outer and inner layer hoppers is 235–245°C; the screw temperature connected to the second outer and second inner layer hoppers is 225–235°C; and the screw temperature connected to the middle layer hopper is 200–220°C, to obtain a molten mixture.

[0175] By controlling the extrusion speed of each hopper, the molten mixture is extruded simultaneously, and the extruded material is blown by the die to form a five-layer co-extruded blown film. The extrusion speeds of each hopper are as follows: the extrusion speed of the molten mixture of the outer and inner layers is 6 m / min, the extrusion speed of the molten mixture of the second outer and second inner layers is 6 m / min, and the extrusion speed of the molten mixture of the middle layer is 8 m / min. The blown film is specifically controlled as follows: the blown film ratio is 1.7, the traction ratio is 6, and the blowing pressure is 0.5 MPa.

[0176] The surface of the outer layer of the obtained five-layer co-extruded film is subjected to corona treatment to make its surface energy 42-48 dynes. The coating layer in Table 4 is coated on the outer layer surface using a coating machine. After coating, it is dried. The linear speed of the drying and blowing coating layer is 10-20 m / min to obtain a five-layer ultra-wide heterogeneous material co-extruded film with a width ≥12m and a total thickness of about 100μm.

[0177] Example 5

[0178] The symmetrical five-layer ultra-wide heterogeneous material co-extruded agricultural film consists of an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer.

[0179] Table 5

[0180]

[0181]

[0182]

[0183] The preparation process of the above five-layer ultra-wide heterogeneous material co-extruded film:

[0184] According to the components in Table 5, the raw materials for each layer—outer layer, second outer layer, middle layer, second inner layer, and inner layer—are fed into the corresponding hoppers of the extrusion blow molding machine. The temperature of each section of the screw extruder is controlled: the screw temperature connected to the outer and inner layer hoppers is 230–245°C, the screw temperature connected to the second outer and second inner layer hoppers is 220–235°C, and the screw temperature connected to the middle layer hopper is 200–220°C, to obtain a molten mixture.

[0185] By controlling the extrusion speed of each hopper, the molten mixture is extruded simultaneously, and the extruded material is blown by the die to form a five-layer co-extruded blown film. The extrusion speeds of each hopper are as follows: the extrusion speed of the molten mixture of the outer and inner layers is 5 m / min, the extrusion speed of the molten mixture of the second outer and second inner layers is 5 m / min, and the extrusion speed of the molten mixture of the middle layer is 5 m / min. The blown film is specifically controlled as follows: the blown film ratio is 1.7, the traction ratio is 6, and the blowing pressure is 0.5 MPa.

[0186] The outer layer of the obtained five-layer co-extruded film was subjected to corona treatment to achieve a surface energy of 42–48 dynes. The coating layers shown in Table 5 were then applied to the outer layer surface using a coating machine. After coating, the film was dried at a conveyor speed of 10–20 m / min to obtain a five-layer ultra-wide heterogeneous material co-extruded film with a width ≥ 12 m and a total thickness of approximately 165 μm. The test data for each of the above embodiments are shown in Table 6.

[0187] Table 6

[0188]

[0189] As shown in Table 6, the five-layer ultra-wide heterogeneous co-extruded films prepared in Examples 1-5 have a width of 12-14 m, a tensile strength (transverse) of 41.2-42.3 MPa, a tensile strength (longitudinal) of 41.2-42.6 MPa, a nominal strain at break of 334.1-375.1%, a right-angle tear strength of 151.7-165.3 KN / m, a light transmittance of 89.6-90.8%, a haze of 14.3-14.6%, and a longitudinal nominal strain retention rate of 61.1-62.1% after aging under a xenon lamp for 4000 h. These films achieve high light transmittance, a hydrophilic inner layer, a dustproof outer layer, high heat insulation, long-lasting light conversion, flexibility, and aging resistance, with a service life ≥ 5 years. They also exhibit good infrared blocking, dustproof, anti-drip, and anti-fogging properties, high tensile strength, good aging and weather resistance, and a long service life.

Claims

1. A five-layer ultra-wide heterogeneous material co-extruded film, comprising an outer layer, a second outer layer, a middle layer, a second inner layer, and an inner layer, arranged sequentially from the outside to the inside; wherein the outer layer is a polyamide layer; the second outer layer is an adhesive resin layer; the middle layer is a functional polyolefin layer; the second inner layer is an adhesive resin layer; the inner layer is a polyamide layer; and a coating layer is provided on the surface of the outer layer; Preferably, The width of the five-layer ultra-wide heterogeneous material co-extruded film is ≥12m; and / or, The thickness ratios of the outer layer, the second outer layer, the middle layer, the second inner layer, and the inner layer are 15-20%, 15-20%, 20-30%, 15-20%, and 15-20%, respectively; and / or, The total thickness of the five-layer ultra-wide heterogeneous co-extruded film is 80–180 μm.

2. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 1, characterized in that: Based on 100 parts by weight of polyamide resin A1, the outer layer and the inner layer are respectively prepared from raw materials comprising the following components: Polyamide resin A 1 100 parts by weight; Polyamide masterbatch A: 4-10 parts by weight; preferably 5-8 parts by weight; More preferably, based on 100 parts by weight of the total weight of polyamide masterbatch A, the polyamide masterbatch A is prepared from raw materials comprising the following components:

3. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 2, characterized in that: The polyamide resin A1 and polyamide resin A2 are each independently selected from at least one homopolymer or copolymer of the following polyamides: PA6, PA66, PA12, PA46, PA610, PA612, PA1010; and / or, The sustained-release agent A is at least one of layered bimetallic hydroxides; and / or, The light stabilizer A is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of benzophenone compounds, benzotriazole compounds, salicylate compounds, substituted acrylonitrile compounds, and triazine compounds; and / or, The antioxidant A is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds.

4. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 2, characterized in that: Based on 100 parts by weight of linear low-density polyethylene resin, the outermost layer and the innermost layer are each independently prepared from raw materials comprising the following components: 100 parts by weight of linear low-density polyethylene resin; 25-45 parts by weight of adhesive resin; preferably 30-40 parts by weight; Polyolefin masterbatch B: 10-25 parts by weight; preferably 10-20 parts by weight; More preferably, based on 100 parts by weight of polyethylene resin B, the polyolefin masterbatch B is prepared from raw materials comprising the following components: The polyethylene resin B includes low-density polyethylene resin B and linear low-density polyethylene resin B; More preferably, the polyethylene resin comprises: Low-density polyethylene resin B: 60-85 parts by weight; Linear low-density polyethylene resin B15-40 parts by weight.

5. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 4, characterized in that: The melt flow indexes of the linear low-density polyethylene resin and linear low-density polyethylene resin B are independently selected from 1.0 to 3.0 g / 10 min; and / or, The bonding resin is maleic anhydride-grafted low-density polyethylene resin with a melt flow index of 1.0–3.0 g / 10 min; and / or, The melt flow index of the low-density polyethylene resin B is 1.0–3.0 g / 10 min; and / or, The sustained-release agent B is at least one layered bimetallic hydroxide; and / or... The light stabilizer B is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of benzophenone compounds, benzotriazole compounds, salicylate compounds, substituted acrylonitrile compounds, and triazine compounds; and / or, The antioxidant B is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds.

6. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 1, characterized in that: The intermediate layer, based on 100 parts by weight of metallocene polyethylene resin, is prepared from raw materials comprising the following components: 100 parts by weight of metallocene polyethylene resin; Polyolefin masterbatch 1# 10-25 parts by weight; Polyolefin masterbatch #2, 10-25 parts by weight; Preferably, Based on 100 parts by weight of polyethylene resin C1, the polyolefin masterbatch 1# is prepared from raw materials comprising the following components: The polyethylene resin C1 includes low-density polyethylene resin C1 and linear low-density polyethylene resin C1; more preferably, the polyethylene resin C includes: 60-80 parts by weight of low-density polyethylene resin C1; 20-40 parts by weight of linear low-density polyethylene resin C1; and / or, Based on 100 parts by weight of polyethylene resin C2, the polyolefin masterbatch 2# is prepared from raw materials comprising the following components: 100 parts by weight of polyethylene resin C2; 5-15 parts by weight of light-converting agent; Antioxidant C2: 0.5–5 parts by weight; The polyethylene resin C2 includes low-density polyethylene resin C2 and linear low-density polyethylene resin C2; more preferably, the polyethylene resin C includes: Low-density polyethylene resin C2: 35-60 parts by weight; 40-65 parts by weight of linear low-density polyethylene resin C2.

7. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 6, characterized in that: The melt flow index of the metallocene polyethylene resin is 0.5–3.0 g / 10 min; and / or, The melt flow indexes of the low-density polyethylene resin C1 and low-density polyethylene resin C2 are independently selected from 1.0 to 3.0 g / 10 min; and / or, The linear low-density polyethylene resin C2 and its melt index are independently selected from 1.0 to 3.0 g / 10 min; and / or, The sustained-release agent C1 is at least one layered bimetallic hydroxide; and / or, The light stabilizer C1 is at least one of an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorber is preferably at least one of benzophenone compounds, benzotriazole compounds, salicylate compounds, substituted acrylonitrile compounds, and triazine compounds; and / or, The light-converting agent is at least one rare earth organic compound or rare earth inorganic compound; and / or, The antioxidant C2 is at least one of hindered phenolic compounds, thiodicarboxylic acid esters, and phosphite compounds.

8. The five-layer ultra-wide heterogeneous material co-extruded film as described in claim 1, characterized in that: The coating layer is prepared from raw materials comprising the following components, based on a total weight of 100 parts by weight: The remainder is water; Preferably, The emulsion particles of the nano-silica sol have a diameter of 3–15 nm; and / or, The SiO2 content of the nano-silica sol is 15–30 wt%; and / or, The pH value of the nano-silica sol is 9–11; and / or, The polyvinyl alcohol resin has a weight-average molecular weight of 120,000 to 180,000; and / or, Five layers of ultra-wide heterogeneous material co-extruded film per square meter, wherein the solid content of the coating layer is 0.2–0.3 g / m². 2 .

9. A method for preparing a five-layer ultra-wide heterogeneous material co-extruded film as described in any one of claims 1 to 8, comprising the following steps: (1) The raw materials of each layer of the outer layer, the second outer layer, the middle layer, the second inner layer and the inner layer in the specified weight parts are respectively fed into the corresponding hopper of the extrusion screw blow molding machine to obtain a molten mixture; (2) The molten mixture obtained in step (1) is simultaneously extruded, and the extruded material is blown through a mold to form a five-layer co-extruded blown film; (3) The outer layer of the five-layer co-extruded blown film obtained in step (3) is coated to obtain the five-layer ultra-wide heterogeneous material co-extruded film; Preferably, In step (1), The temperatures of each section of the screw extruder are as follows: the screw temperature connected to the outer and inner hoppers is 225–245°C; the screw temperature connected to the second outer and second inner hoppers is 200–235°C; the screw temperature connected to the middle hopper is 190–220°C; and / or, In step (2), The extrusion speeds of each hopper of the screw extruder are as follows: the extrusion speed of the molten mixture in the outer and inner layers is 5–10 m / min; the extrusion speed of the molten mixture in the second outer and second inner layers is 5–10 m / min; and the extrusion speed of the molten mixture in the middle layer is 5–10 m / min; and / or, The specific conditions for inflation include: controlling the inflation ratio to be 1.2–2.5; the traction ratio to be 5–7; the inflation pressure to be 0.3–0.6 MPa; and / or, In step (3), The coating process includes, in sequence, corona treatment, surface coating, and drying. More preferably, The corona treatment involves applying a corona treatment to the surface of the outer layer of the five-layer co-extruded blown film to achieve a surface energy of 42–48 dynes; and / or, The surface coating is achieved by applying the coating layer to the outer surface of a five-layer co-extruded blown film greenhouse film that has undergone corona treatment using a coating machine; and / or... The drying process involves drying the coated five-layer co-extruded blown film; more preferably, the drying temperature is 50–70°C; and / or, the linear speed of the conveyor for drying the coating layer is 10–20 m / min.

10. The application of a five-layer ultra-wide heterogeneous material co-extruded film as described in any one of claims 1 to 8 or a five-layer ultra-wide heterogeneous material co-extruded film obtained by the preparation method described in claim 9 in the agricultural field, preferably in agricultural greenhouses and land fumigation.

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