A filler masterbatch, its preparation method and application

Abstract

This invention discloses a filler masterbatch, its preparation method, and its application. The filler masterbatch comprises the following raw materials in parts by weight: 8-10 parts of silane coupling agent-grafted PUA resin; 2-3 parts of dispersant; 2-3 parts of 2,6-di-tert-butyl-4-methylphenol; 20-25 parts of modified nano-calcium carbonate powder; 40-45 parts of modified nano-barium sulfate powder; 3-5 parts of toughening resin; and 18-20 parts of low-density PE resin. The silane coupling agent-grafted PUA resin in the filler masterbatch contains two types of groups with different chemical properties: one type is siloxane groups that are affinity for inorganic powders, readily reacting with them; the other type is PUA segments that are affinity for PE resin, readily forming hydrogen bonds with the PE resin. This silane coupling agent-grafted PUA resin can improve the interfacial adhesion between the inorganic powder and the PE resin, thereby significantly improving the mechanical properties of PE films prepared using it.

Description

Technical Field

[0001] This invention relates to the field of PE film technology, and more specifically, to a filler masterbatch, its preparation method, and its application. Background Technology

[0002] Polyethylene (PE) film is widely used in packaging and protective materials for everyday life and industrial products due to its excellent flexibility, elongation, low-temperature resistance, chemical stability, and ease of molding and processing. To reduce the raw material cost of PE film, a small amount of filler masterbatch prepared from inorganic powder or a certain amount of recycled granules is usually added to the PE resin. However, both of these cost-reduction methods may bring some problems: First, the poor compatibility between inorganic powder and PE resin leads to a decrease in the adhesion between the inorganic powder and PE resin, which in turn reduces the cohesive strength of the PE film. Consequently, the tensile strength and elongation at break of the PE film prepared by adding a certain amount of filler masterbatch decrease significantly. This is manifested in the poor mechanical properties of the PE film prepared by blending and blowing film forming using inorganic powder to prepare filler masterbatch through conventional granulation methods. In particular, when the proportion of filler masterbatch in the PE film raw material components is greater than 40%, the tensile strength and elongation at break of the PE film decrease significantly, rendering it unusable. Second, the sources of recycled materials are complex, especially since recycled materials may contain a large amount of dust, impurities, and oil. Recycled materials containing these substances have a great impact on the quality stability of PE films. This makes the surface tension properties of PE films prepared by blending and blowing film forming using recycled granules added to PE resin extremely unstable, with large fluctuations in mechanical properties, which limits the application range of PE films, especially in product applications with requirements for appearance and quality stability.

[0003] In current technology, to ensure that the mechanical properties of PE film meet the requirements for use, the proportion of filler masterbatch added to PE film is generally controlled below 40%. Otherwise, the tensile strength and elongation at break of PE film will decrease to varying degrees. At the same time, the surface tension is not easy to stabilize. With the extension of aging time, some small molecule additives in PE film will slowly migrate or precipitate out of the film surface. After heating and aging, the surface tension will decrease significantly, resulting in the peeling or residue of the adhesive layer on the surface of PE film, which limits the application range of PE film.

[0004] Therefore, in order to increase the proportion of inorganic powder in PE film while maintaining the good mechanical properties and surface tension properties of PE film, this invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide filler masterbatch, preparation method and application, which increases the proportion of inorganic powder in PE film while maintaining good mechanical properties and surface tension properties of PE film.

[0006] This invention is implemented as follows:

[0007] In a first aspect, the present invention provides a filler masterbatch comprising the following parts by weight of raw materials:

[0008] 8-10 parts of silane coupling agent grafted onto PUA resin;

[0009] 2-3 parts dispersant;

[0010] 2,6-Di-tert-butyl-4-methylphenol, 2-3 parts;

[0011] 20-25 parts of modified nano-calcium carbonate powder;

[0012] 40-45 parts of modified nano-barium sulfate powder;

[0013] 3-5 parts toughening resin;

[0014] 18-20 parts of low-density PE resin.

[0015] In an optional embodiment, the method for preparing the silane coupling agent-grafted PUA resin includes: reacting a hybrid diol with isocyanate acrylate and using azobisisobutyronitrile as an initiator to carry out a free radical polymerization reaction to synthesize the silane coupling agent-grafted PUA resin.

[0016] In an optional embodiment, a reaction solution containing hybrid diol, isocyanate acrylate and ethyl acetate is reacted at a temperature of 70-75°C for 3-4 hours, and then an initiator is added dropwise over 15-20 minutes to continue the reaction for 3-4 hours to synthesize a silane coupling agent grafted PUA resin.

[0017] Preferably, the reaction between the hybrid diol and the isocyanate acrylate uses ethyl acetate as a solvent, and the molar ratio of the hybrid diol, the isocyanate acrylate, and the ethyl acetate is 1:1.8-2.2:0.9-1.1.

[0018] Preferably, the amount of azobisisobutyronitrile used is 0.38% to 0.42% of the total weight of the hybrid diol and isocyanate acrylate;

[0019] Preferably, the preparation of the hybrid diol includes the following steps: mixing γ-aminopropyltriethoxysilane (KH-550) and epichlorohydrin at a molar ratio of 1:2.0-2.1, and reacting at 55-60°C for 5-6 hours;

[0020] Preferably, the preparation of the isocyanate acrylate includes the following steps: mixing ethyl acetate, isophorone diisocyanate and hydroxypropyl acrylate in a molar ratio of 1:0.9-1.1:0.9-1.1, and reacting at 55-60°C for 4-5 hours.

[0021] In an optional embodiment, the dispersant is at least one of oxidized polyethylene wax, maleic anhydride-grafted polyethylene wax MA4351 from Clariant GmbH, Germany, and paraffin wax.

[0022] And / or, the modified nano-calcium carbonate powder is at least one of maleic anhydride modified nano-calcium carbonate powder, stearate n-butyl ester modified nano-calcium carbonate powder, and aluminate coupling agent modified nano-calcium carbonate powder.

[0023] And / or, the modified nano barium sulfate powder is at least one of the following: YL-3500 from Guangdong Yuanlei Powder Co., Ltd., AY-JB53 from Foshan Anyi Nanomaterials Co., Ltd., and XM-MPB633 from Guangdong Xinmei Nanotechnology Co., Ltd.

[0024] And / or, the toughening resin is at least one of the following: ethylene-octene copolymer elastomer resin POE (POE8999) from Dow Chemical Company, USA; ethylene-vinyl acetate copolymer resin EVA (EA28025) from LG Chem Corporation, Korea; and maleic anhydride-grafted linear low-density polyethylene resin PE-g-MAH (VtecPCA G102) from Shanghai Fushen New Material Technology Co., Ltd.

[0025] In a second aspect, the present invention provides a method for preparing a filler masterbatch according to any one of the foregoing embodiments, comprising: mixing a silane coupling agent grafted with PUA resin, a dispersant, 2,6-di-tert-butyl-4-methylphenol, modified nano-calcium carbonate powder, and modified nano-barium sulfate powder to obtain a first mixture; mixing the first mixture with a toughening resin and a low-density PE resin to obtain a second mixture; and then transferring the second mixture to a twin-screw extruder for extrusion molding to obtain a filler masterbatch.

[0026] Preferably, the mixing temperature of the raw materials for the filler masterbatch is 70~80℃;

[0027] Preferably, the twin-screw extruder has a zone setting temperature of 150±2℃, a zone setting temperature of 165±2℃, a zone setting temperature of 165±2℃, and a die setting temperature of 160±2℃.

[0028] Thirdly, the present invention provides an application of a filler masterbatch as described in any of the foregoing embodiments in a PE film.

[0029] Fourthly, the present invention provides a high-filling-weight PE film, comprising a first PE layer, a second PE film layer, and a third PE film layer disposed sequentially, wherein...

[0030] The first PE layer comprises the following parts by weight of raw materials:

[0031] 20-30 parts of low-density PE resin;

[0032] 20-30 parts of linear low-density PE resin;

[0033] 45-55 parts of filler masterbatch;

[0034] The second PE layer comprises the following parts by weight of raw materials:

[0035] 18-22 parts of metallocene-catalyzed linear low-density PE resin;

[0036] 75-85 parts of filler masterbatch;

[0037] The third PE layer comprises the following parts by weight of raw materials:

[0038] 30-40 parts of low-density PE resin;

[0039] 30-40 parts of linear low-density PE resin;

[0040] Filler masterbatch 25-35 parts.

[0041] Preferably, the thickness ratio of the first PE layer, the second PE layer, and the third PE layer is 18-22%: 55-65%: 18-22%.

[0042] In an optional embodiment, the density of the high-filling-weight PE film is ≥1.40 g / cm³. 3 The transverse tensile strength is ≥8MPa, and the transverse elongation at break is ≥350%; the longitudinal tensile strength is ≥10MPa, and the longitudinal elongation at break is ≥500%; the surface tension of the third PE layer after aging at 60℃ for 168h is ≥42mN / m.

[0043] Fifthly, the present invention provides a method for preparing a high-filling-weight PE film, wherein the first PE layer, the second PE layer and the third PE layer are obtained by melt co-extrusion blown film blowing.

[0044] In an optional embodiment, the temperatures of each zone of the screw extruder corresponding to the first PE layer are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min.

[0045] And / or, the temperature settings for each zone of the screw extruder corresponding to the second PE layer are as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 60±2r / min;

[0046] And / or, the temperatures of each zone of the screw extruder corresponding to the third PE layer are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min.

[0047] And / or, after the temperatures of the three screw extruders have all reached the set temperature and stabilized, the three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by the AC frequency converter to be: first PE layer screw extruder : second PE layer screw extruder : third PE layer screw extruder = 1 : 2 : 1. The melt extruded through the die is processed through film drawing, blowing, stretching, traction, corona treatment, edge trimming and winding to prepare a high-filling PE film.

[0048] The present invention has the following beneficial effects:

[0049] The silane coupling agent grafted onto PUA resin in the filler masterbatch is a macromolecular coupling agent containing two types of chemically distinct groups in its molecular structure: one type consists of siloxane groups that are affinity-for-inorganic powders, readily reacting with them; the other type consists of PUA segments that are affinity-for-PE resins, readily forming hydrogen bonds with the PE resin. This silane coupling agent grafted onto PUA resin improves the interfacial adhesion between inorganic powders and PE resin, thereby significantly enhancing the mechanical properties of PE films prepared using it. Simultaneously, the blending of this macromolecular coupling agent into the PE film formed from PE resin helps improve the tensile strength and elongation at break of the PE film, while also preventing the migration and precipitation of small molecules. This ensures stable surface tension of the PE film, preventing a decrease in surface tension due to high-temperature aging or prolonged natural aging, thus improving the adhesion of surface coatings and expanding the application range of PE films. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of a high-filling-content PE film.

[0052] Diagram: 1-First PE layer; 2-Second PE layer; 3-Third PE layer. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0054] One embodiment of this application provides a filler masterbatch comprising the following parts by weight of raw materials:

[0055] 8-10 parts of silane coupling agent grafted onto PUA resin;

[0056] 2-3 parts dispersant;

[0057] 2,6-Di-tert-butyl-4-methylphenol, 2-3 parts;

[0058] 20-25 parts of modified nano-calcium carbonate powder;

[0059] 40-45 parts of modified nano-barium sulfate powder;

[0060] 3-5 parts toughening resin;

[0061] 18-20 parts of low-density PE resin.

[0062] In this application, the inorganic powder in the filler masterbatch is uniformly dispersed, without agglomeration or crystallization, and exhibits good compatibility with the PE matrix resin. This is because the silane coupling agent grafted onto PUA resin in the filler masterbatch is a macromolecular coupling agent containing two types of chemically distinct groups in its molecular structure: one type is the siloxane group that is affinity-for-inorganic powder, readily reacting with it; the other type is the PUA (polyurethane acrylate) segment that is affinity-for-PE resin, readily forming hydrogen bonds with it. This silane coupling agent grafted onto PUA resin improves the interfacial adhesion between the inorganic powder and the PE resin, thereby significantly enhancing the mechanical properties of PE films prepared using it. Simultaneously, the blending of this macromolecular coupling agent into the PE film formed from the PE resin improves the tensile strength and elongation at break of the PE film, while also preventing the migration and precipitation of small molecules, ensuring stable surface tension of the PE film. This prevents a decrease in surface tension due to high-temperature aging or prolonged natural aging, thus improving the adhesion of the surface coating and expanding the application range of PE films.

[0063] The silane coupling agent grafted onto PUA resin imparts excellent adhesion between the nano-calcium carbonate powder and nano-barium sulfate powder in the filler masterbatch and the PE resin. The dispersant provides excellent dispersion for the two nano-inorganic powders. The selected toughening agent effectively improves the elongation at break of the high-filler PE film. The filler masterbatch increases the density of the PE film while reducing the cost of the PE film.

[0064] In an optional embodiment, the method for preparing the silane coupling agent-grafted PUA resin includes: reacting a hybrid diol with isocyanate acrylate and using azobisisobutyronitrile as an initiator to carry out a free radical polymerization reaction to synthesize the silane coupling agent-grafted PUA resin.

[0065] In an optional embodiment, a reaction solution containing hybrid diol, isocyanate acrylate and ethyl acetate is reacted at a temperature of 70-75°C for 3-4 hours, and then an initiator is added dropwise over 15-20 minutes to continue the reaction for 3-4 hours to synthesize a silane coupling agent grafted PUA resin.

[0066] Preferably, the reaction between the hybrid diol and the isocyanate acrylate uses ethyl acetate as a solvent, and the molar ratio of the hybrid diol, the isocyanate acrylate, and the ethyl acetate is 1:1.8-2.2:0.9-1.1.

[0067] Preferably, the amount of azobisisobutyronitrile used is 0.38% to 0.42% of the total weight of the hybrid diol and isocyanate acrylate;

[0068] Preferably, the preparation of the hybrid diol includes the following steps: mixing γ-aminopropyltriethoxysilane (KH-550) and epichlorohydrin at a molar ratio of 1:2.0-2.1, and reacting at 55-60°C for 5-6 hours;

[0069] Preferably, the preparation of the isocyanate acrylate includes the following steps: mixing ethyl acetate, isophorone diisocyanate and hydroxypropyl acrylate in a molar ratio of 1:0.9-1.1:0.9-1.1, and reacting at 55-60°C for 4-5 hours.

[0070] In this embodiment, the chemical synthesis route involves reacting a small molecule coupling agent, γ-aminopropyltriethoxysilane (KH-550), with epichlorohydrin to synthesize a hybrid diol; reacting isophorone diisocyanate with hydroxypropyl acrylate to synthesize an isocyanate acrylate (IPDI-HPA); then reacting the hybrid diol with IPDI-HPA, using azobisisobutyronitrile as an initiator, to finally synthesize a silane coupling agent grafted PUA resin.

[0071] Specifically, in some embodiments, the preparation method of silane coupling agent grafted PUA resin is as follows:

[0072] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0073] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was complete, the temperature was raised to 55-60°C, and the reaction was continued for 4-5 hours. The mixture was then cooled and stored for later use.

[0074] (C) Preparation of silane coupling agent-grafted PUA resin: A hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70-75℃. Using a constant-pressure funnel, isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture, controlling the molar ratio of hybrid diol:IPDI-HPA:Ea to be 1:2:1. After the addition was complete, the temperature was raised to 70-75℃, and the reaction was allowed to proceed for 3-4 hours. Azobisisobutyronitrile dissolved in Ea was added dropwise over 15-20 minutes to initiate a free radical polymerization reaction, continuing the reaction for another 3-4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0075] In an optional embodiment, the dispersant is at least one of oxidized polyethylene wax, maleic anhydride-grafted polyethylene wax MA4351 from Clariant GmbH, Germany, and paraffin wax.

[0076] And / or, the modified nano-calcium carbonate powder is at least one of maleic anhydride modified nano-calcium carbonate powder, stearate n-butyl ester modified nano-calcium carbonate powder, and aluminate coupling agent modified nano-calcium carbonate powder.

[0077] And / or, the modified nano barium sulfate powder is at least one of the following: YL-3500 from Guangdong Yuanlei Powder Co., Ltd., AY-JB53 from Foshan Anyi Nanomaterials Co., Ltd., and XM-MPB633 from Guangdong Xinmei Nanotechnology Co., Ltd.

[0078] These two inorganic powders were modified by different methods to coat their surfaces, which improved their adhesion to PE resin. The two worked together to ensure that the tensile strength and elongation at break of the prepared PE film did not decrease significantly, meeting the requirements for use, and also avoiding the agglomeration and crystal formation of inorganic powders.

[0079] And / or, the toughening resin is at least one of the following: ethylene-octene copolymer elastomer resin POE (POE8999) from Dow Chemical Company, USA; ethylene-vinyl acetate copolymer resin EVA (EA28025) from LG Chem Corporation, Korea; and maleic anhydride-grafted linear low-density polyethylene resin PE-g-MAH (VtecPCA G102) from Shanghai Fushen New Material Technology Co., Ltd.

[0080] When these polymer resins containing flexible segments are added to filler masterbatches, they can further improve the compatibility between inorganic powders and PE resins. Through the combination of hydrogen bonds and semi-interpenetrating networks, they can inhibit the generation and propagation of cracks in PE films under external forces, enabling them to withstand greater external forces and improving the elongation at break of high-filler PE films.

[0081] Another embodiment of this application provides a method for preparing the filler masterbatch described in any one of the foregoing embodiments, comprising: mixing a silane coupling agent grafted with PUA resin, a dispersant, 2,6-di-tert-butyl-4-methylphenol, modified nano-calcium carbonate powder, and modified nano-barium sulfate powder to obtain a first mixture; mixing the first mixture with a toughening resin and a low-density PE resin to obtain a second mixture; and then transferring the second mixture to a twin-screw extruder for extrusion molding to obtain the filler masterbatch.

[0082] Preferably, the mixing temperature of the raw materials for the filler masterbatch is 70~80℃;

[0083] Preferably, the twin-screw extruder has a zone setting temperature of 150±2℃, a zone setting temperature of 165±2℃, a zone setting temperature of 165±2℃, and a die setting temperature of 160±2℃.

[0084] Specifically, in some embodiments, the preparation method of the filler masterbatch includes: adding silane coupling agent-grafted PUA resin, dispersant, 2,6-di-tert-butyl-4-methylphenol, modified nano-calcium carbonate powder, and modified nano-barium sulfate powder to a high-speed mixer according to the mass ratio of the raw material components; covering the mixer; heating to 70-80°C; starting the stirring motor; controlling the speed at 500-1000 r / min; and stirring for 80-90 min. Then, adding toughening resin and low-density PE resin, and continuing stirring for 30 min, followed by heat preservation. The twin-screw extruder is then heated, with zone one set at 150°C, zone two at 165°C, zone three at 165°C, and the die head at 160°C. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the twin-screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0085] Another embodiment of this application provides the application of a filler masterbatch as described in any of the foregoing embodiments in a PE film.

[0086] The PE film prepared by using the aforementioned filler masterbatch and PE resin for melt co-extrusion blown film preparation has a high filler ratio, high density, good mechanical properties and stable surface tension.

[0087] Another embodiment of this application provides a high-filling-weight PE film, comprising a first PE layer, a second PE film layer, and a third PE film layer sequentially disposed thereon, wherein...

[0088] The first PE layer comprises the following parts by weight of raw materials:

[0089] 20-30 parts of low-density PE resin;

[0090] 20-30 parts of linear low-density PE resin;

[0091] 45-55 parts of filler masterbatch;

[0092] The second PE layer comprises the following parts by weight of raw materials:

[0093] 18-22 parts of metallocene-catalyzed linear low-density PE resin;

[0094] 75-85 parts of filler masterbatch;

[0095] The third PE layer comprises the following parts by weight of raw materials:

[0096] 30-40 parts of low-density PE resin;

[0097] 30-40 parts of linear low-density PE resin;

[0098] Filler masterbatch 25-35 parts.

[0099] The high-filler PE film in this embodiment comprises three layers. The first PE layer is used for ink printing. Therefore, the first PE layer needs to maintain a certain mechanical property while maintaining a smooth surface to avoid blurry or unclear patterns in the ink printing. The second PE layer is located in the middle and has relatively lower requirements for its mechanical properties, surface smoothness, and surface tension. Therefore, a larger amount of filler masterbatch is added to the second PE layer to effectively increase the proportion of filler masterbatch. The third PE layer needs to have its composition adjusted to maintain a certain mechanical property while keeping the surface tension stable.

[0100] Specifically, in this embodiment, the PE resin in the high-filling-weight PE film is a combination of low-density PE resin and metallocene-catalyzed linear low-density PE resin. Low-density PE resin has lower cost but lower strength and higher elongation. Therefore, it is used in combination with metallocene-catalyzed linear low-density PE resin, which has higher strength and lower elongation, to achieve complementary advantages. The silane coupling agent grafted onto PUA resin improves the compatibility between the PE resin and the inorganic powder in the filler masterbatch. Furthermore, as those skilled in the art know, PE resin and other raw materials contain small molecules such as opening agents and slip agents. As the high-density PE film is used for an extended period, some of these small molecules gradually migrate to the film surface, potentially reducing the surface tension of the high-filling-weight PE film and causing the adhesive layer coated on the PE film surface to transfer. In this embodiment, the silane coupling agent grafted onto PUA resin can inhibit the migration or precipitation of small molecules, stabilizing the adhesion of the adhesive layer to the PE film, thereby mitigating or preventing adhesive layer transfer.

[0101] Preferably, the thickness ratio of the first PE layer, the second PE layer, and the third PE layer is 18-22%: 55-65%: 18-22%. In some embodiments, the thickness of the high-filling-weight PE film is 150±5μm.

[0102] In an optional embodiment, the density of the high-filling-weight PE film is ≥1.40 g / cm³. 3 The transverse tensile strength is ≥8MPa, and the transverse elongation at break is ≥350%; the longitudinal tensile strength is ≥10MPa, and the longitudinal elongation at break is ≥500%; the surface tension of the third PE layer after aging at 60℃ for 168h is ≥42mN / m.

[0103] Another embodiment of this application provides a method for preparing a high-filling-weight PE film, wherein the first PE layer, the second PE layer and the third PE layer are obtained by melt co-extrusion blown film blowing.

[0104] In an optional embodiment, the temperatures of each zone of the screw extruder corresponding to the first PE layer are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min.

[0105] And / or, the temperature settings for each zone of the screw extruder corresponding to the second PE layer are as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 60±2r / min;

[0106] And / or, the temperatures of each zone of the screw extruder corresponding to the third PE layer are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min.

[0107] And / or, after the temperatures of the three screw extruders have all reached the set temperature and stabilized, the three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by the AC frequency converter to be: first PE layer screw extruder : second PE layer screw extruder : third PE layer screw extruder = 1 : 2 : 1. The melt extruded through the die is processed through film drawing, blowing, stretching, traction, corona treatment, edge trimming and winding to prepare a high-filling PE film.

[0108] Specifically, in some embodiments, the method for preparing a high-filling-content PE film includes the following steps:

[0109] 1) Add low-density PE resin, linear low-density PE resin and filler masterbatch into the screw extruder hopper corresponding to the first PE layer according to the raw material ratio designed for the first PE layer. Set the temperature of each zone of the screw extruder as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. Set the screw speed to 35±2r / min.

[0110] 2) Add the metallocene-catalyzed linear low-density PE resin and filler masterbatch to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. Set the temperature of each zone of the screw extruder as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. Set the screw speed to 70±2r / min.

[0111] 3) Add low-density PE resin, linear low-density PE resin and filler masterbatch to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. Set the temperature of each zone of the screw extruder as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. Set the screw speed to 35±2r / min.

[0112] 4) After the temperature reaches the set temperature and stabilizes for 30 minutes, start the three screw extruders at the same time. Control the speed ratio of the screw extruders through the AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die then goes through processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming and winding to prepare a high-filling PE film.

[0113] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0114] Example 1

[0115] A method for preparing a filler masterbatch and its high-filler-content PE film includes the following steps:

[0116] (1) Preparation of silane coupling agent grafted PUA resin:

[0117] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0118] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was completed, the temperature was raised to 55~60℃ and the reaction was continued for 4~5 hours. The mixture was then cooled and stored for later use.

[0119] (C) Preparation of silane coupling agent grafted PUA resin: Hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70~75℃. Isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture of hybrid diol and Ea using a constant pressure funnel. The molar ratio of hybrid diol:IPDI-HPA:Ea was controlled to be 1:2:1. After the addition was completed, the temperature was raised to 70~75℃ and the reaction was carried out for 3~4 hours. Azobisisobutyronitrile dissolved with Ea was added dropwise at 15~20 min. The amount of azobisisobutyronitrile was 0.4% of the total weight of hybrid diol and isocyanate acrylate. Free radical polymerization reaction was carried out and the reaction was continued for 3~4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0120] (2) Preparation of filler masterbatch:

[0121] The following raw materials, in parts by weight, are melt-extruded and granulated using a twin-screw extruder:

[0122] 8 parts of PUA resin grafted with silane coupling agent;

[0123] 3 parts of oxidized polyethylene wax;

[0124] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0125] 25 parts of maleic anhydride modified nano-calcium carbonate powder;

[0126] 40 parts of modified nano-barium sulfate powder (YL-3500);

[0127] 4 copies of POE (POE8999);

[0128] 18 parts of low-density PE resin;

[0129] According to the above-mentioned raw material components by mass proportions, add silane coupling agent-grafted PUA resin, oxidized polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, maleic anhydride-modified nano-calcium carbonate powder, and modified nano-barium sulfate powder to a high-speed mixer, cover, heat to 75°C, start the stirring motor, control the speed at 800 r / min, and time for 80 min. Then add POE (POE8999) and low-density PE resin, continue stirring for 30 min, and keep warm for later use. Start heating the twin-screw extruder, setting the temperature to 150°C for zone 1, 165°C for zone 2, 165°C for zone 3, and 160°C for the die head. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0130] (3) Preparation of high-filling-content PE film:

[0131] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0132] The first PE layer is composed of the following parts by weight of raw materials:

[0133] 25% low-density PE resin;

[0134] 25% linear low-density PE resin;

[0135] 50% filler masterbatch;

[0136] The second PE layer is composed of the following raw materials in parts by weight:

[0137] Metallocene-catalyzed linear low-density PE resin 20%;

[0138] 80% filler masterbatch;

[0139] The third PE layer is composed of the following raw materials in parts by weight:

[0140] 35% low-density PE resin;

[0141] 35% linear low-density PE resin;

[0142] 30% filler masterbatch;

[0143] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35 r / min.

[0144] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70 r / min.

[0145] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35 r / min.

[0146] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0147] The prepared high-filler PE film, as shown in... Figure 1 As shown in Table 1, the thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension after aging at 60℃ for 168 hours were measured.

[0148] Example 2

[0149] A method for preparing a filler masterbatch and its high-filler-content PE film includes the following steps:

[0150] (1) Preparation of silane coupling agent grafted PUA resin:

[0151] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0152] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was complete, the temperature was raised to 55-60°C, and the reaction was continued for 4-5 hours. The mixture was then cooled and stored for later use.

[0153] (C) Preparation of silane coupling agent grafted PUA resin: Hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70~75℃. Isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture of hybrid diol and Ea using a constant pressure funnel. The molar ratio of hybrid diol:IPDI-HPA:Ea was controlled to be 1:2:1. After the addition was completed, the temperature was raised to 70~75℃ and the reaction was carried out for 3~4 hours. Azobisisobutyronitrile dissolved in ethyl acetate was added dropwise at 15~20 min. The amount of azobisisobutyronitrile was 0.4% of the total weight of hybrid diol and isocyanate acrylate. Free radical polymerization reaction was carried out and the reaction was continued for 3~4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0154] (2) Preparation of filler masterbatch:

[0155] The following raw materials, in parts by weight, are melt-extruded and granulated using a twin-screw extruder:

[0156] 10 parts of PUA resin grafted with silane coupling agent;

[0157] Two parts of maleic anhydride-grafted polyethylene wax;

[0158] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0159] 20 parts of n-butyl stearate modified nano-calcium carbonate powder;

[0160] 45 parts of modified nano-barium sulfate powder (XM-MPB633);

[0161] 3 copies of EVA (EA28025);

[0162] 18 parts of low-density PE resin;

[0163] According to the above-mentioned raw material components by mass proportions, add silane coupling agent-grafted PUA resin, maleic anhydride-grafted polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, stearate-modified nano-calcium carbonate powder, and modified nano-barium sulfate powder to a high-speed mixer, cover, heat to 80°C, start the stirring motor, control the speed at 500 r / min, and time for 90 min. Then add EVA (EA28025) and low-density PE resin, continue stirring for 30 min, and keep warm for later use. Start heating the twin-screw extruder, setting the temperature to 150°C for zone 1, 165°C for zone 2, 165°C for zone 3, and 160°C for the die head. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0164] (3) Preparation of high-filling-content PE film:

[0165] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0166] The first PE layer is composed of the following parts by weight of raw materials:

[0167] 25% low-density PE resin;

[0168] 25% linear low-density PE resin;

[0169] 50% filler masterbatch;

[0170] The second PE layer is composed of the following raw materials in parts by weight:

[0171] Metallocene-catalyzed linear low-density PE resin 20%;

[0172] 80% filler masterbatch;

[0173] The third PE layer is composed of the following raw materials in parts by weight:

[0174] 35% low-density PE resin;

[0175] 35% linear low-density PE resin;

[0176] 30% filler masterbatch;

[0177] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0178] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0179] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0180] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0181] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the high-filled PE film were measured. The test results are shown in Table 1.

[0182] Example 3

[0183] A method for preparing a filler masterbatch and its high-filler-content PE film includes the following steps:

[0184] (1) Preparation of silane coupling agent grafted PUA resin:

[0185] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0186] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was complete, the temperature was raised to 55-60°C, and the reaction was continued for 4-5 hours. The mixture was then cooled and stored for later use.

[0187] (C) Preparation of silane coupling agent grafted PUA resin: Hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70~75℃. Isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture of hybrid diol and Ea using a constant pressure funnel. The molar ratio of hybrid diol:IPDI-HPA:Ea was controlled to be 1:2:1. After the addition was completed, the temperature was raised to 70~75℃ and the reaction was carried out for 3~4 hours. Azobisisobutyronitrile dissolved in ethyl acetate was added dropwise at 15~20 min. The amount of azobisisobutyronitrile was 0.4% of the total weight of hybrid diol and isocyanate acrylate. Free radical polymerization reaction was carried out and the reaction was continued for 3~4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0188] (2) Preparation of filler masterbatch:

[0189] The following raw materials, in parts by weight, are melt-extruded and granulated using a twin-screw extruder:

[0190] Nine parts of PUA resin grafted with silane coupling agent;

[0191] 2 parts paraffin;

[0192] 3 parts of 2,6-di-tert-butyl-4-methylphenol;

[0193] 22 parts of aluminate coupling agent modified nano-calcium carbonate powder;

[0194] 41 parts of modified nano-barium sulfate powder (XM-MPB633);

[0195] 3 portions of PE-g-MAH (VtecPCA G102);

[0196] 20 parts of low-density PE resin;

[0197] According to the above-mentioned raw material components by mass proportions, silane coupling agent-grafted PUA resin, paraffin wax, 2,6-di-tert-butyl-4-methylphenol, aluminate coupling agent-modified nano-calcium carbonate powder, and modified nano-barium sulfate powder (XM-MPB633) were added to a high-speed mixer. The mixer was covered, heated to 70°C, and the stirring motor was started. The speed was controlled at 1000 r / min for 90 min. Then, PE-g-MAH (VtecPCA G102) and low-density PE resin were added, and stirring was continued for 30 min. The mixture was then kept warm for later use. The twin-screw extruder was heated, with the following temperature settings: Zone 1: 150°C; Zone 2: 165°C; Zone 3: 165°C; and Die Head: 160°C. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0198] (3) Preparation of high-filling-content PE film:

[0199] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0200] The first PE layer is composed of the following parts by weight of raw materials:

[0201] 25% low-density PE resin;

[0202] 25% linear low-density PE resin;

[0203] 50% filler masterbatch;

[0204] The second PE layer is composed of the following raw materials in parts by weight:

[0205] Metallocene-catalyzed linear low-density PE resin 20%;

[0206] 80% filler masterbatch;

[0207] The third PE layer is composed of the following raw materials in parts by weight:

[0208] 35% low-density PE resin;

[0209] 35% linear low-density PE resin;

[0210] 30% filler masterbatch;

[0211] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0212] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0213] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0214] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0215] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the high-filled PE film were measured. The test results are shown in Table 1.

[0216] Example 4

[0217] A method for preparing a filler masterbatch and its high-filler-content PE film includes the following steps:

[0218] (1) Preparation of silane coupling agent grafted PUA resin:

[0219] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0220] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was complete, the temperature was raised to 55-60°C, and the reaction was continued for 4-5 hours. The mixture was then cooled and stored for later use.

[0221] (C) Preparation of silane coupling agent grafted PUA resin: Hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70~75℃. Isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture of hybrid diol and Ea using a constant pressure funnel. The molar ratio of hybrid diol:IPDI-HPA:Ea was controlled to be 1:2:1. After the addition was completed, the temperature was raised to 70~75℃ and the reaction was carried out for 3~4 hours. Azobisisobutyronitrile dissolved in ethyl acetate was added dropwise at 15~20 min. The amount of azobisisobutyronitrile was 0.4% of the total weight of hybrid diol and isocyanate acrylate. Free radical polymerization reaction was carried out and the reaction was continued for 3~4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0222] (2) Preparation of filler masterbatch:

[0223] The following raw materials, in parts by weight, are melt-extruded and granulated using a twin-screw extruder:

[0224] 8 parts of PUA resin grafted with silane coupling agent;

[0225] Two parts of maleic anhydride-grafted polyethylene wax;

[0226] 3 parts of 2,6-di-tert-butyl-4-methylphenol;

[0227] 21 parts of maleic anhydride modified nano-calcium carbonate powder;

[0228] 43 parts of modified nano-barium sulfate powder (AY-JB53);

[0229] 5 copies of POE (POE8999);

[0230] 18 parts of low-density PE resin;

[0231] According to the above-mentioned raw material components by mass proportions, silane coupling agent-grafted PUA resin, maleic anhydride-grafted polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, maleic anhydride-modified nano-calcium carbonate powder, and modified nano-barium sulfate powder (AY-JB53) were added to a high-speed mixer. The mixer was covered, heated to 78°C, and the stirring motor was started. The speed was controlled at 700 r / min for 85 min. Then, POE (POE8999) and low-density PE resin were added, and stirring was continued for 30 min. The mixture was then kept warm for later use. The twin-screw extruder was heated, with the following temperature settings: Zone 1: 150°C; Zone 2: 165°C; Zone 3: 165°C; and Die Head: 160°C. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0232] (3) Preparation of high-filling-content PE film:

[0233] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0234] The first PE layer is composed of the following parts by weight of raw materials:

[0235] 25% low-density PE resin;

[0236] 25% linear low-density PE resin;

[0237] 50% filler masterbatch;

[0238] The second PE layer is composed of the following raw materials in parts by weight:

[0239] Metallocene-catalyzed linear low-density PE resin 20%;

[0240] 80% filler masterbatch;

[0241] The third PE layer is composed of the following raw materials in parts by weight:

[0242] 35% low-density PE resin;

[0243] 35% linear low-density PE resin;

[0244] 30% filler masterbatch;

[0245] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0246] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0247] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0248] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0249] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the high-filled PE film were measured. The test results are shown in Table 1.

[0250] Example 5

[0251] A method for preparing a filler masterbatch and its high-filler-content PE film includes the following steps:

[0252] (1) Preparation of silane coupling agent grafted PUA resin:

[0253] (A) Preparation of hybrid diols: γ-aminopropyltriethoxysilane (KH-550) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. The stirrer was turned on, and epichlorohydrin was slowly added dropwise using a constant pressure funnel at room temperature, controlling the molar ratio of KH-550 to epichlorohydrin to be 1:2.05. After the addition was complete, the reactants were heated to 55-60°C and reacted for 5-6 hours. The mixture was then cooled and stored for later use.

[0254] (B) Preparation of isocyanate acrylate: Isophorone diisocyanate (IPDI) was added to a four-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hydroxypropyl acrylate (HPA) diluted with ethyl acetate (Ea) was slowly added dropwise under ice-water bath conditions, controlling the molar ratio of IPDI:HPA:Ea to be 1:1:1. After the addition was complete, the temperature was raised to 55-60°C, and the reaction was continued for 4-5 hours. The mixture was then cooled and stored for later use.

[0255] (C) Preparation of silane coupling agent grafted PUA resin: Hybrid diol and Ea were added to a four-necked flask equipped with a stirrer, thermometer and reflux condenser to obtain a mixture of hybrid diol and Ea with a molar ratio of 2:1. The temperature was raised to 70~75℃. Isocyanate acrylate (IPDI-HPA) diluted with Ea was added dropwise to the mixture of hybrid diol and Ea using a constant pressure funnel. The molar ratio of hybrid diol:IPDI-HPA:Ea was controlled to be 1:2:1. After the addition was completed, the temperature was raised to 70~75℃ and the reaction was carried out for 3~4 hours. Azobisisobutyronitrile dissolved in ethyl acetate was added dropwise at 15~20 min. The amount of azobisisobutyronitrile was 0.4% of the total weight of hybrid diol and isocyanate acrylate. Free radical polymerization reaction was carried out and the reaction was continued for 3~4 hours. Ethyl acetate was removed by vacuum distillation, and the prepared silane coupling agent-grafted PUA resin was poured out while hot and stored in a sealed container for later use.

[0256] (2) Preparation of filler masterbatch:

[0257] The following raw materials, in parts by weight, are melt-extruded and granulated using a twin-screw extruder:

[0258] 10 parts of PUA resin grafted with silane coupling agent;

[0259] 3 parts of oxidized polyethylene wax;

[0260] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0261] 23 parts of n-butyl stearate modified nano-calcium carbonate powder;

[0262] 40 parts of modified nano-barium sulfate powder (YL-3500);

[0263] 3 copies of EVA (EA28025);

[0264] 19 parts of low-density PE resin;

[0265] According to the above-mentioned raw material components by mass proportions, silane coupling agent-grafted PUA resin, oxidized polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, stearate-modified nano-calcium carbonate powder, and modified nano-barium sulfate powder (YL-3500) were added to a high-speed mixer. The mixer was covered, heated to 73°C, and the stirring motor was started. The speed was controlled at 900 r / min for 83 min. Then, EVA (EA28025) and low-density PE resin were added, and stirring was continued for 30 min. The mixture was then kept warm for later use. The twin-screw extruder was heated, with the following temperature settings: Zone 1: 150°C; Zone 2: 165°C; Zone 3: 165°C; and Die Head: 160°C. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0266] (3) Preparation of high-filling-content PE film:

[0267] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0268] The first PE layer is composed of the following parts by weight of raw materials:

[0269] 25% low-density PE resin;

[0270] 25% linear low-density PE resin;

[0271] 50% filler masterbatch;

[0272] The second PE layer is composed of the following raw materials in parts by weight:

[0273] Metallocene-catalyzed linear low-density PE resin 20%;

[0274] 80% filler masterbatch;

[0275] The third PE layer is composed of the following raw materials in parts by weight:

[0276] 35% low-density PE resin;

[0277] 35% linear low-density PE resin;

[0278] 30% filler masterbatch;

[0279] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0280] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0281] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0282] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0283] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the high-filled PE film were measured. The test results are shown in Table 1.

[0284] Comparative Example 1

[0285] The difference between this comparative example and Example 1 is that the first, second, and third PE layers of the PE film do not contain filler masterbatch. A composite PE film is prepared using a three-layer melt co-extrusion blown film process with the following steps:

[0286] The first PE layer is composed of the following parts by weight of raw materials:

[0287] Low-density PE resin 50%;

[0288] 50% linear low-density PE resin;

[0289] The second PE layer is composed of the following raw materials in parts by weight:

[0290] 100% metallocene-catalyzed linear low-density PE resin;

[0291] The third PE layer is composed of the following raw materials in parts by weight:

[0292] Low-density PE resin 50%;

[0293] 50% linear low-density PE resin;

[0294] Low-density PE resin and linear low-density PE resin are added to the screw extruder hopper corresponding to the first PE layer according to the raw material ratio designed for the first PE layer. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0295] Metallocene-catalyzed linear low-density PE resin was added to the screw extruder hopper corresponding to the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0296] Low-density PE resin and linear low-density PE resin were added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 35±2 r / min.

[0297] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0298] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the prepared PE film after aging at 60℃ for 168h were measured. The test results are shown in Table 1.

[0299] Comparative Example 2

[0300] The difference between this comparative example and Example 1 is that the first PE layer of the PE film does not contain filler masterbatch. A composite PE film is prepared using a three-layer melt co-extrusion blown film process with the following steps:

[0301] The first PE layer is composed of the following parts by weight of raw materials:

[0302] Low-density PE resin 50%;

[0303] 50% linear low-density PE resin;

[0304] The second PE layer is composed of the following raw materials in parts by weight:

[0305] Metallocene-catalyzed linear low-density PE resin 20%;

[0306] 80% filler masterbatch;

[0307] The third PE layer is composed of the following raw materials in parts by weight:

[0308] 35% low-density PE resin;

[0309] 35% linear low-density PE resin;

[0310] 30% filler masterbatch;

[0311] Low-density PE resin and linear low-density PE resin are added to the screw extruder hopper corresponding to the first PE layer according to the raw material ratio designed for the first PE layer. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0312] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0313] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0314] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0315] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the prepared PE film after aging at 60℃ for 168h were measured. The test results are shown in Table 1.

[0316] Comparative Example 3

[0317] The difference between this comparative example and Example 1 is that the second PE layer of the PE film does not contain filler masterbatch. A composite PE film is prepared using a three-layer melt co-extrusion blown film process with the following steps:

[0318] The first PE layer is composed of the following parts by weight of raw materials:

[0319] 25% low-density PE resin;

[0320] 25% linear low-density PE resin;

[0321] 50% filler masterbatch;

[0322] The second PE layer is composed of the following raw materials in parts by weight:

[0323] 100% metallocene-catalyzed linear low-density PE resin;

[0324] The third PE layer is composed of the following raw materials in parts by weight:

[0325] 35% low-density PE resin;

[0326] 35% linear low-density PE resin;

[0327] 30% filler masterbatch;

[0328] Low-density PE resin and linear low-density PE resin are added to the screw extruder hopper corresponding to the first PE layer according to the raw material ratio designed for the first PE layer. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0329] Metallocene-catalyzed linear low-density PE resin was added to the screw extruder hopper corresponding to the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0330] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35±2 r / min.

[0331] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0332] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the prepared PE film after aging at 60℃ for 168h were measured. The test results are shown in Table 1.

[0333] Comparative Example 4

[0334] The difference between this comparative example and Example 1 is that the third PE layer of the PE film does not contain filler masterbatch. A composite PE film is prepared using a three-layer melt co-extrusion blown film process with the following steps:

[0335] The first PE layer is composed of the following parts by weight of raw materials:

[0336] 25% low-density PE resin;

[0337] 25% linear low-density PE resin;

[0338] 50% filler masterbatch;

[0339] The second PE layer is composed of the following raw materials in parts by weight:

[0340] Metallocene-catalyzed linear low-density PE resin 20%;

[0341] 80% filler masterbatch;

[0342] The third PE layer is composed of the following raw materials in parts by weight:

[0343] Low-density PE resin 50%;

[0344] 50% linear low-density PE resin;

[0345] Low-density PE resin and linear low-density PE resin are added to the screw extruder hopper corresponding to the first PE layer according to the raw material ratio designed for the first PE layer. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35±2r / min.

[0346] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70±2 r / min.

[0347] Low-density PE resin and linear low-density PE resin were added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 35±2 r / min.

[0348] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0349] The thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension of the prepared PE film after aging at 60℃ for 168h were measured. The test results are shown in Table 1.

[0350] Comparative Example 5

[0351] A method for preparing a high-filling-content PE film differs from Example 1 only in the raw materials: the silane coupling agent grafted onto PUA resin in the PE film is replaced with an equal mass of γ-aminopropyltriethoxysilane (KH-550).

[0352] Filler masterbatch was prepared by melt extrusion granulation using a twin-screw extruder with the following raw material composition in parts by weight:

[0353] 8 parts of γ-aminopropyltriethoxysilane (KH-550);

[0354] 3 parts of oxidized polyethylene wax;

[0355] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0356] 25 parts of maleic anhydride modified nano-calcium carbonate powder;

[0357] 40 parts of modified nano-barium sulfate powder (YL-3500);

[0358] 4 copies of POE (POE8999);

[0359] 18 parts of low-density PE resin;

[0360] According to the above-mentioned raw material components by mass proportions, γ-aminopropyltriethoxysilane (KH-550), oxidized polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, maleic anhydride modified nano-calcium carbonate powder, and modified nano-barium sulfate powder were added to a high-speed mixer. The mixer was covered, heated to 75°C, and the stirring motor was started, with the speed controlled at 800 r / min for 80 min. Then, POE (POE8999) and low-density PE resin were added, and stirring was continued for 30 min. The mixture was then kept warm for later use. The twin-screw extruder was then heated, with the following temperature settings: Zone 1: 150°C; Zone 2: 165°C; Zone 3: 165°C; and Die Head: 160°C. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0361] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0362] The first PE layer is composed of the following parts by weight of raw materials:

[0363] 25% low-density PE resin;

[0364] 25% linear low-density PE resin;

[0365] 50% filler masterbatch;

[0366] The second PE layer is composed of the following raw materials in parts by weight:

[0367] Metallocene-catalyzed linear low-density PE resin 20%;

[0368] 80% filler masterbatch;

[0369] The third PE layer is composed of the following raw materials in parts by weight:

[0370] 35% low-density PE resin;

[0371] 35% linear low-density PE resin;

[0372] 30% filler masterbatch;

[0373] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35 r / min.

[0374] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70 r / min.

[0375] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35 r / min.

[0376] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0377] The prepared high-filler PE film, as shown in... Figure 1As shown in Table 1, the thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension after aging at 60℃ for 168 hours were measured.

[0378] Comparative Example 6

[0379] A method for preparing a high-filler-weight PE film differs from Example 1 only in the raw materials: the modified nano-calcium carbonate powder in the PE film is replaced with an equal mass of commercially available nano-calcium carbonate powder (Jinxin 1250 from Dongguan Jinxin Powder Technology Co., Ltd.); the modified nano-barium sulfate powder in the PE base film is replaced with an equal mass of commercially available general-purpose ultrafine barium sulfate powder (Yuanlei Powder 5000 mesh from Guangdong Yuanlei Powder Co., Ltd.). The raw materials are composed of the following parts by weight, and melt extrusion granulation is performed using a twin-screw extruder to prepare the filler masterbatch:

[0380] 8 parts of PUA resin grafted with silane coupling agent;

[0381] 3 parts of oxidized polyethylene wax;

[0382] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0383] 25 parts of nano-calcium carbonate powder;

[0384] 40 parts of ultrafine barium sulfate powder;

[0385] 4 copies of POE (POE8999);

[0386] 18 parts of low-density PE resin;

[0387] According to the above-mentioned raw material components by mass proportions, add the silane coupling agent-grafted PUA resin, oxidized polyethylene wax, 2,6-di-tert-butyl-4-methylphenol, nano-calcium carbonate powder, and ultrafine barium sulfate powder to a high-speed mixer, cover, heat to 75°C, start the stirring motor, control the speed at 800 r / min, and time for 80 min. Then add POE (POE8999) and low-density PE resin, continue stirring for 30 min, and keep warm for later use. Start heating the twin-screw extruder, setting the temperature to 150°C for zone 1, 165°C for zone 2, 165°C for zone 3, and 160°C for the die head. Once the set temperature is reached, the mixture is transferred to the extruder hopper, the screw extruder is started, and the melt is extruded and shaped into round bars with a diameter of 3±0.5mm using a special die. The bars are then pulled by a conveyor belt to a pelletizer, where they are cooled by a fan during the pulling process and cut into particles with a length of 3±0.5mm. After metering, the particles are packaged to complete the preparation of the filler masterbatch.

[0388] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0389] The first PE layer is composed of the following parts by weight of raw materials:

[0390] 25% low-density PE resin;

[0391] 25% linear low-density PE resin;

[0392] 50% filler masterbatch;

[0393] The second PE layer is composed of the following raw materials in parts by weight:

[0394] Metallocene-catalyzed linear low-density PE resin 20%;

[0395] 80% filler masterbatch;

[0396] The third PE layer is composed of the following raw materials in parts by weight:

[0397] 35% low-density PE resin;

[0398] 35% linear low-density PE resin;

[0399] 30% filler masterbatch;

[0400] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35 r / min.

[0401] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70 r / min.

[0402] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35 r / min.

[0403] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0404] The prepared high-filler PE film, as shown in... Figure 1 As shown in Table 1, the thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension after aging at 60℃ for 168 hours were measured.

[0405] Comparative Example 7

[0406] A method for preparing a high-filler PE film differs from Example 1 only in that the amount of silane coupling agent-grafted PUA resin in the filler masterbatch is reduced. Specifically, the filler masterbatch is prepared by melt extrusion granulation using a twin-screw extruder with the following raw material composition in parts by weight:

[0407] 4 parts of PUA resin grafted with silane coupling agent;

[0408] 3 parts of oxidized polyethylene wax;

[0409] 2,6-Di-tert-butyl-4-methylphenol, 2 parts;

[0410] 25 parts of maleic anhydride modified nano-calcium carbonate powder;

[0411] 40 parts of modified nano-barium sulfate powder (YL-3500);

[0412] 4 copies of POE (POE8999);

[0413] 18 parts of low-density PE resin;

[0414] The raw material components for the first PE layer, the second PE layer, and the third PE layer are weighed out according to the following parts by weight, mixed evenly, and added to the corresponding hoppers. A composite film is then prepared using a three-layer melt co-extrusion blown film process:

[0415] The first PE layer is composed of the following parts by weight of raw materials:

[0416] 25% low-density PE resin;

[0417] 25% linear low-density PE resin;

[0418] 50% filler masterbatch;

[0419] The second PE layer is composed of the following raw materials in parts by weight:

[0420] Metallocene-catalyzed linear low-density PE resin 20%;

[0421] 80% filler masterbatch;

[0422] The third PE layer is composed of the following raw materials in parts by weight:

[0423] 35% low-density PE resin;

[0424] 35% linear low-density PE resin;

[0425] 30% filler masterbatch;

[0426] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the first PE layer according to the designed raw material ratio. The temperature of each zone of the screw extruder is set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃. The screw speed is set to 35 r / min.

[0427] Metallocene-catalyzed linear low-density PE resin and filler masterbatch were added to the screw extruder hopper corresponding to the second PE layer according to the raw material ratio designed for the second PE layer. The temperatures of each zone of the screw extruder were set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed was set to 70 r / min.

[0428] Low-density PE resin, linear low-density PE resin, and filler masterbatch are added to the screw extruder hopper corresponding to the third PE layer according to the raw material ratio designed for the third PE layer. The temperatures of each zone of the screw extruder are set as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, and Die 160±2℃. The screw speed is set to 35 r / min.

[0429] Once the temperature reaches the set temperature and stabilizes for 30 minutes, all three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by an AC frequency converter to be: first PE layer screw extruder: second PE layer screw extruder: third PE layer screw extruder = 1:2:1. The melt extruded through the die undergoes processes such as film drawing, blowing, stretching, traction, corona treatment, edge trimming, and winding to prepare a high-filling PE film.

[0430] The prepared high-filler PE film, as shown in... Figure 1 As shown in Table 1, the thickness, density, transverse tensile strength, transverse elongation at break, longitudinal tensile strength, longitudinal elongation at break, and surface tension after aging at 60℃ for 168 hours were measured.

[0431] Table 1. Summary of performance test results for each embodiment and comparative example.

[0432]

[0433] Thickness test: The thickness of the PE film was tested according to GB / T7125-2014 "Test method for thickness of adhesive tape". The thickness was measured 5 times at different locations and the average value was taken.

[0434] Density test: The density of PE film was tested according to GB / T36053-2018 "X-ray reflection method for measuring the thickness, density and interface width of thin films". The density was measured 5 times at different locations and the average value was taken.

[0435] Mechanical property testing: Mechanical property testing was conducted according to GB / T1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets", with an ambient temperature of 23±1℃ and a relative humidity of 55±5%. The PE film was cut into 10mm wide strips, and the tensile strength and elongation at break were tested using a material tensile testing machine. The tests were performed in parallel three times, and the average value was taken.

[0436] Surface tension test: The surface tension of PE film was tested according to GB / T4216-2008 "Determination of wetting tension of plastic film and sheet". After aging at 60℃ for 168h, it was tested with a dyne pen after being placed at room temperature for 1h.

[0437] As shown in Table 1, the high-filler PE film prepared using the present invention exhibits higher density in Examples 1, 2, 3, 4, and 5. Its tensile strength and elongation at break also meet the usage requirements, and its surface tension is stable, showing no significant decrease even after aging at 60°C for 168 hours. In contrast, the PE film in Comparative Example 1, the first PE layer in Comparative Example 2, the second PE layer in Comparative Example 3, and the third PE layer in Comparative Example 4 do not contain filler masterbatch. Their corresponding densities are lower than those in Examples 1-5, while their tensile strength and elongation at break are superior. However, the aging stability of the surface tension in the first and third PE layers is inferior to that in Examples 1-5. Comparative Example 5 used γ-aminopropyltriethoxysilane (KH550) instead of silane coupling agent to graft PUA resin. Comparative Example 6 used commercially available general-purpose nano-calcium carbonate and general-purpose ultrafine barium sulfate instead of modified nano-calcium carbonate and modified nano-barium sulfate, respectively. Comparative Example 7 reduced the amount of silane coupling agent grafted PUA resin by half in the preparation of filler masterbatch. The mechanical properties of the corresponding PE films all decreased to varying degrees, and the surface tension of the PE films also decreased.

[0438] As shown in Table 1, a comparison of the high-filler PE film prepared using the method of the present invention with Examples 1-5 and Comparative Example 1 (which does not contain filler masterbatch) shows that the density of the high-filler PE film is greater than that of Comparative Example 1. This indicates that the addition of filler masterbatch significantly reduces the cost of the PE film, and also provides good surface tension stability. A comparison of Examples 1-5 with Comparative Examples 2-7 shows that the first PE layer of Comparative Example 2, the second PE layer of Comparative Example 3, and the third PE layer of Comparative Example 4, which do not contain filler masterbatch, all show a slight decrease in density, a slight increase in tensile strength and elongation at break, and surface tension stability that is inferior to that of Examples 1-5. A comparison of Examples 1-5 with Comparative Examples 5-7 shows that the mechanical properties and surface tension properties of the corresponding PE films are all lower than those of Examples 1-5.

[0439] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A filler masterbatch, characterized in that, The raw materials include the following parts by weight: 8-10 parts of silane coupling agent grafted onto PUA resin; 2-3 parts dispersant; 2,6-Di-tert-butyl-4-methylphenol, 2-3 parts; 20-25 parts of modified nano-calcium carbonate powder; 40-45 parts of modified nano-barium sulfate powder; 3-5 parts toughening resin; 18-20 parts of low-density PE resin; The method for preparing the silane coupling agent-grafted PUA resin includes: reacting a reaction solution containing a hybrid diol, isocyanate acrylate, and ethyl acetate at a temperature of 70-75°C for 3-4 hours, then adding azobisisobutyronitrile dropwise over 15-20 minutes and continuing the reaction for another 3-4 hours to synthesize the silane coupling agent-grafted PUA resin; the preparation of the hybrid diol includes the following steps: mixing γ-aminopropyltriethoxysilane and epichlorohydrin at a molar ratio of 1:2.0-2.1 and reacting at 55-60°C for 5-6 hours; the preparation of the isocyanate acrylate includes the following steps: mixing ethyl acetate, isophorone diisocyanate, and hydroxypropyl acrylate at a molar ratio of 1:0.9-1.1:0.9-1.1 and reacting at 55-60°C for 4-5 hours; The modified nano-calcium carbonate powder is at least one of maleic anhydride modified nano-calcium carbonate powder, stearate n-butyl ester modified nano-calcium carbonate powder, and aluminate coupling agent modified nano-calcium carbonate powder. The modified nano-barium sulfate powder is at least one of the following: Foshan Anyi Nanomaterials Co., Ltd. brand AY-JB53 and Guangdong Xinmei Nanotechnology Co., Ltd. brand XM-MPB633. The toughening resin is at least one of the following: ethylene-octene copolymer elastomer resin POE (POE8999) from Dow Chemical Company, USA; ethylene-vinyl acetate copolymer resin EVA (EA28025) from LG Chem Corporation, Korea; and maleic anhydride-grafted linear low-density polyethylene resin PE-g-MAH (VtecPCA G102) from Shanghai Fushen New Material Technology Co., Ltd.

2. The filler masterbatch according to claim 1, characterized in that, The reaction of the hybrid diol with isocyanate acrylate uses ethyl acetate as a solvent, and the molar ratio of the hybrid diol, isocyanate acrylate and ethyl acetate is 1:1.8-2.2:0.9-1.

1.

3. The filler masterbatch according to claim 1, characterized in that, The amount of azobisisobutyronitrile used is 0.38% to 0.42% of the total weight of the hybrid diol, isocyanate acrylate, and acrylate.

4. A filler masterbatch according to claim 1, characterized in that, The dispersant is at least one of oxidized polyethylene wax, maleic anhydride-grafted polyethylene wax (brand name MA4351) from Clariant GmbH, Germany, and paraffin wax.

5. A method for preparing a filler masterbatch according to any one of claims 1-4, characterized in that, include: A first mixture is obtained by grafting silane coupling agent onto PUA resin, dispersant, 2,6-di-tert-butyl-4-methylphenol, modified nano-calcium carbonate powder, and modified nano-barium sulfate powder. The first mixture is then mixed with toughening resin and low-density PE resin to obtain a second mixture. The second mixture is then transferred to a twin-screw extruder for extrusion molding to obtain filler masterbatch.

6. The method for preparing a filler masterbatch according to claim 5, characterized in that, The mixing temperature of the raw materials for the filler masterbatch is 70~80℃.

7. The method for preparing a filler masterbatch according to claim 5, characterized in that, The twin-screw extruder has a zone temperature setting of 150±2℃, a zone temperature setting of 165±2℃, a zone temperature setting of 165±2℃, and a die temperature setting of 160±2℃.

8. The application of a filler masterbatch as described in any one of claims 1-4 in a PE film.

9. A high-filling-weight PE film, characterized in that, It includes a first PE layer, a second PE layer, and a third PE layer arranged sequentially, wherein, The first PE layer comprises the following parts by weight of raw materials: 20-30 parts of low-density PE resin; 20-30 parts of linear low-density PE resin; 45-55 parts of the filler masterbatch as described in any one of claims 1-4; The second PE layer comprises the following parts by weight of raw materials: 18-22 parts of metallocene-catalyzed linear low-density PE resin; 75-85 parts of the filler masterbatch as described in any one of claims 1-4; The third PE layer comprises the following parts by weight of raw materials: 30-40 parts of low-density PE resin; 30-40 parts of linear low-density PE resin; 25-35 parts of the filler masterbatch according to any one of claims 1-4.

10. The high-filling-weight PE film according to claim 9, characterized in that, The thickness ratio of the first PE layer, the second PE layer, and the third PE layer is 18-22%: 55-65%: 18-22%.

11. A method for preparing a high-filling-weight PE film according to claim 9 or 10, characterized in that, The high-filling-content PE film is obtained by melt co-extrusion blown film of the first PE layer, the second PE layer and the third PE layer.

12. The method for preparing a high-filling-weight PE film according to claim 11, characterized in that, The temperature settings for each zone of the screw extruder corresponding to the first PE layer are as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min. And / or, the temperature settings for each zone of the screw extruder corresponding to the second PE layer are as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 60±2r / min; And / or, the temperature settings of each zone of the screw extruder corresponding to the third PE layer are as follows: Zone 1 148±2℃, Zone 2 155±2℃, Zone 3 160±2℃, Zone 4 165±2℃, Zone 5 160±2℃, Runner 160±2℃, Die 160±2℃, and the screw speed is set to 30±2r / min; And / or, after the temperatures of the three screw extruders have all reached the set temperature and stabilized, the three screw extruders are started simultaneously. The speed ratio of the screw extruders is controlled by the AC frequency converter to be: first PE layer screw extruder : second PE layer screw extruder : third PE layer screw extruder = 1 : 2 :

1. The melt extruded through the die is processed through film drawing, blowing, stretching, traction, corona treatment, edge trimming and winding to prepare a high-filling PE film.

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