High-barrier multi-layer co-extrusion composite film

Abstract

The invention relates to the technical field of packaging materials, and discloses a high-barrier multilayer co-extrusion composite film which sequentially comprises an inner layer, a first bonding layer, a first barrier layer, a second bonding layer, a second barrier layer, a third bonding layer and an outer layer from bottom to top. And the second barrier layer is a nano silicon dioxide modified polyvinyl alcohol layer. The two different barrier layers are arranged, the first barrier layer has a good barrier effect on gas, the second barrier layer has outstanding barrier performance on water vapor, and the two barrier layers have a synergistic effect, so that the comprehensive barrier performance of the composite film on oxygen, water vapor, peculiar smell and the like is remarkably improved, the shelf life of a packaged product can be effectively prolonged, and the packaging cost is reduced. According to the high-barrier film, the high-barrier property is ensured, the quality and the performance of a product are ensured, and the use of expensive materials and a complex production process is avoided and the production cost is reduced by reasonably selecting each layer of material and optimizing the structural design on the premise of ensuring the high-barrier property.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, in particular to a high-barrier multi-layer co-extruded composite film. Background Art

[0002] In the field of packaging materials, composite films are widely used for packaging a variety of products. However, existing composite films have certain deficiencies in barrier properties, making it difficult to meet the packaging needs of products with high barrier requirements for oxygen, water vapor, odor, etc.

[0003] Although some composite films improve barrier properties by increasing the thickness of the barrier layer, this will increase material costs and packaging weight, and may also affect the flexibility and processing performance of the composite film. Summary of the Invention

[0004] The present application discloses a high-barrier multi-layer co-extruded composite film to solve the problems of poor barrier performance and high cost in the prior art.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions: A high-barrier multi-layer co-extruded composite film, comprising, from bottom to top, an inner layer, a first adhesive layer, a first barrier layer, a second adhesive layer, a second barrier layer, a third adhesive layer and an outer layer; The first barrier layer is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0006] Furthermore, a first functional layer is provided between the third adhesive layer and the outer layer, and the first functional layer can be used for antibacterial or antistatic properties; And / or, a second functional layer is provided between the inner layer and the first adhesive layer, and the second functional layer can be used for anti-fog and / or anti-freeze and / or antibacterial properties.

[0007] Furthermore, a third barrier layer is provided between the third adhesive layer and the outer layer, and a fourth adhesive layer is provided between the third barrier layer and the outer layer.

[0008] Furthermore, the third barrier layer is a polyethylene naphthalate layer.

[0009] Furthermore, a first functional layer is provided between the fourth adhesive layer and the outer layer, and the first functional layer can be used for antibacterial or antistatic properties; And / or, a second functional layer is provided between the inner layer and the first adhesive layer, and the second functional layer can be used for anti-fog and / or anti-freeze and / or antibacterial properties.

[0010] Furthermore, the inner layer is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0011] Furthermore, the outer layer is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0012] Furthermore, the first adhesive layer, the second adhesive layer and the third adhesive layer are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0013] Furthermore, the first functional layer is a polyethylene layer modified with silver-loaded nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

[0014] Furthermore, the second functional layer is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; Wherein, the antibacterial masterbatch is chitosan or sodium alginate.

[0015] The technical solution adopted by the present invention can achieve the following beneficial effects: The present invention provides two different barrier layers, the first barrier layer has a good barrier effect on gas, and the second barrier layer has outstanding barrier performance against water vapor. The two barrier layers work synergistically to significantly improve the comprehensive barrier performance of the composite film against oxygen, water vapor, odor, etc., which can effectively extend the shelf life of the packaged products and ensure the quality and performance of the products; the inner layer has excellent flexibility and heat sealing properties, which is convenient for packaging operations, and the outer layer has good gloss and printability, which improves the aesthetics and commodity value of the packaging. At the same time, the layers are tightly combined by the adhesive layer, which ensures that the composite film has good mechanical strength and flexibility and is not easily damaged or deformed during processing and use; by reasonably selecting the materials of each layer and optimizing the structural design, while ensuring high barrier performance, the use of overly expensive materials and complex production processes is avoided, the production cost is reduced, and the market competitiveness of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic structural diagram of Example 1 of the present application; Figure 2 This is a schematic diagram of the structure of Example 2 of the present application; Figure 3 This is a schematic structural diagram of Example 3 of the present application; Figure 4 This is a schematic structural diagram of Example 4 of the present application; Figure 5 This is a schematic structural diagram of Example 5 of the present application; Figure 6 This is a schematic diagram of the structure of Example 6 of the present application; Figure 7 is a structural diagram of Example 7 of the present application; Figure 8 It is a structural diagram of Example 8 of the present application.

[0018] In the picture: 100-inner layer; 200-first adhesive layer; 300-first barrier layer; 400-second adhesive layer; 500-second barrier layer; 600-third adhesive layer; 700-outer layer; 800-first functional layer; 900-second functional layer; 1000-third barrier layer; 1100-fourth adhesive layer. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0020] The terms "first", "second", "third", "fourth", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", "third", "fourth", etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0021] The inventors discovered during actual use that existing composite films exhibit certain deficiencies in barrier performance, making them inadequate for packaging products with high barrier requirements against oxygen, water vapor, and odors. For example, in food packaging, the penetration of oxygen and water vapor can lead to oxidation, deterioration, moisture, and mold, shortening the shelf life of the food. In pharmaceutical packaging, poor barrier properties can cause the drug to react with substances in the external environment, affecting its quality and efficacy. While some composite films improve barrier performance by increasing the thickness of the barrier layer, this increases material cost and packaging weight, and can also affect the film's flexibility and processing properties.

[0022] The following is combined with Figures 1 to 8 , a high barrier multi-layer co-extruded composite film provided by the present application is described in detail through specific embodiments and application scenarios.

[0023] Example 1 Reference Figure 1 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; Specifically, the thickness of the first barrier layer 300 is 5-10 microns; the polyvinylidene chloride (PVDC) layer and the ethylene vinyl alcohol copolymer (EVOH) layer have excellent gas barrier properties, which can effectively block the penetration of gases such as oxygen and carbon dioxide, prevent the packaged products from oxidizing and deteriorating, and extend the shelf life of the products.

[0024] The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0025] Specifically, the thickness of the second barrier layer 500 is 5-10 microns. By adding nano-silicon dioxide (SiO2) to polyvinyl alcohol (PVA), the barrier properties of polyvinyl alcohol can be further improved, especially the barrier effect against water vapor is significant, while the mechanical strength and wear resistance of the material are enhanced.

[0026] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0027] Specifically, the thickness of the inner layer 100 is 10-20 microns; by using a linear low-density polyethylene (LLDPE) layer or a metallocene polyethylene (mPE) layer, the inner layer has good flexibility, heat sealing properties and chemical stability, can be in direct contact with the packaged product, protect the product from contamination, and facilitate heat sealing operations during the packaging process to form a sealed packaging space.

[0028] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0029] Specifically, the thickness of the outer layer 700 is 15-25 microns; by using a biaxially oriented polypropylene (BOPP) layer or a biaxially oriented polyester (BOPET) layer, the outer layer has good glossiness, printability and mechanical strength, which facilitates printing and pattern design on the surface of the composite film, while protecting the internal layer structure and improving the overall durability of the composite film.

[0030] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 and the third adhesive layer 600 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0031] Specifically, the thickness of the first adhesive layer 200, the second adhesive layer 400 and the third adhesive layer 600 are all 3-5 microns; by using an ethylene-ethyl acrylate copolymer (EEA) layer or an ethylene-methacrylic acid copolymer (EMAA) layer, the bonding strength between the two adjacent layers is enhanced, the stability of the composite film structure is ensured, and interlayer separation is prevented; in this embodiment, a strong bond is achieved between the inner layer 100 and the first barrier layer 300 by the first adhesive layer 200; a strong bond is achieved between the first barrier layer 300 and the second barrier layer 500 by the second adhesive layer 400; and a strong bond is achieved between the second barrier layer 500 and the outer layer 700 by the third adhesive layer 600.

[0032] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. The composite film has comprehensive barrier properties against oxygen, water vapor, odor, etc., has good mechanical strength and flexibility, is not easy to be damaged or deformed during processing and use, and has cost advantages, thereby improving the market competitiveness of the product.

[0033] Example 2 Reference Figure 2 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a first functional layer 800 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0034] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0035] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0036] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 and the third adhesive layer 600 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0037] Specifically, the thicknesses and materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 and the outer layer 700 are consistent with those in Example 1.

[0038] In this embodiment, the first functional layer 800 can be used for antibacterial or antistatic purposes. The first functional layer 800 is a polyethylene layer modified with silver nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

[0039] Specifically, the thickness of the first functional layer 800 is 8-12 microns; different materials can be selected for the first functional layer 800 according to different packaging requirements; when used for food packaging, the first functional layer 800 can use materials with antibacterial properties, such as a polyethylene (PE) layer modified with silver-loaded nano-titanium dioxide (TiO2). By adding silver-loaded nano-titanium dioxide (TiO2) to polyethylene, the growth and reproduction of bacteria can be inhibited, thereby ensuring the safety and hygiene of food; when used for electronic product packaging, the first functional layer 800 can use materials with anti-static properties, such as a polypropylene (PP) layer modified with carbon nanotubes. By adding carbon nanotubes to polypropylene, electronic products can be prevented from being damaged by static electricity.

[0040] When the first functional layer 800 is a polyethylene (PE) layer modified with silver-loaded nano-titanium dioxide (TiO2), the above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The various parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. The composite film can be used for food packaging, has comprehensive barrier properties against oxygen, water vapor, odor, etc., has good mechanical strength and flexibility, and has good antibacterial properties, and can effectively inhibit the growth of Escherichia coli and Staphylococcus aureus.

[0041] When the first functional layer 800 is a carbon nanotube-modified polypropylene (PP) layer, the above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The various parameters of the blow molding machine can be adjusted according to actual conditions to obtain the high-barrier multi-layer co-extruded composite film. The composite film can be used for the packaging of electronic products, has comprehensive barrier properties against oxygen, water vapor, odor, etc., has good mechanical strength and flexibility, and has good anti-static properties, and can effectively protect electronic products.

[0042] Example 3 Reference Figure 3 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a second functional layer 900, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0043] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0044] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0045] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 and the third adhesive layer 600 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0046] Specifically, the thicknesses and materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 and the outer layer 700 are consistent with those in Example 1.

[0047] In this embodiment, the second functional layer 900 can be used for anti-fog and / or antifreeze and / or antibacterial purposes. The second functional layer 900 is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; wherein the antibacterial masterbatch is chitosan or sodium alginate.

[0048] Specifically, the thickness of the second functional layer 900 is 6-10 microns; the second functional layer 900 can be made of different materials according to different packaging requirements; when used for food packaging, the second functional layer 900 can be an anti-fog layer and / or an antifreeze layer and / or an antibacterial layer, that is, the second functional layer 900 can be an anti-fog layer; the second functional layer 900 can be an antifreeze layer; the second functional layer 900 can be an antibacterial layer; the second functional layer 900 can be an anti-fog layer and an antifreeze layer; the second functional layer 900 can adopt an anti-fog layer and an antibacterial layer; the second functional layer 900 can adopt an anti-freeze layer and an antibacterial layer; the second functional layer 900 can adopt an anti-fog layer, an anti-freeze layer and an antibacterial layer; the anti-fog layer can be selected according to actual needs, the anti-freeze layer makes it difficult for the composite film surface to generate fog, the anti-freeze layer can be used to prevent the composite film surface from icing, and the antibacterial layer makes the composite film have good antibacterial properties; the arrangement order of the anti-fog layer, anti-freeze layer and antibacterial layer from bottom to top is antibacterial layer, anti-fog layer and anti-freeze layer; When used for electronic product packaging, the second functional layer 900 can be an anti-fog layer and / or an anti-freeze layer, that is, the second functional layer 900 can be an anti-fog layer; the second functional layer 900 can be an anti-freeze layer; the second functional layer 900 can be an anti-fog layer and an anti-freeze layer; the selection can be made according to actual needs; the arrangement order of the anti-fog layer and the anti-freeze layer is from bottom to top: anti-fog layer and anti-freeze layer; The second functional layer 900 can be made of a material with anti-fog properties, such as an ethylene-vinyl acetate copolymer (EVA) layer, which can prevent fogging on the surface of the composite film and has good heat insulation and thermal insulation functions, thereby improving the freshness of food in food packaging. The second functional layer 900 can be made of a material with antifreeze properties, such as a polyurethane (PU) layer, which enables the composite film to maintain flexibility at low temperatures (brittle temperature < -50°C) and has a certain degree of self-repairing ability (microcracks can be healed at low temperatures). Another example is an acrylic copolymer layer, which has a low glass transition temperature (below -40°C) at low temperatures, maintaining the flexibility of the composite film and providing good transparency (light transmittance > 90%), making it suitable for optical devices (such as radomes and camera lenses). The second functional layer 900 can be made of a material with antibacterial properties, such as an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer and an antibacterial masterbatch, wherein the antibacterial masterbatch is chitosan or sodium alginate, which can make the composite film have good antibacterial properties and can effectively inhibit most bacteria, fungi, molds, spores and other microorganisms to ensure food safety and hygiene.

[0049] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. The composite film has comprehensive barrier properties against oxygen, water vapor, odor, etc., has good mechanical strength and flexibility, is not easy to be damaged or deformed during processing and use, and enables the composite film to have a single function or multiple functions at the same time, making the composite film more practical.

[0050] Example 4 Reference Figure 4 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a second functional layer 900, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a first functional layer 800 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0051] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0052] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0053] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 and the third adhesive layer 600 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0054] Specifically, the thicknesses and materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 and the outer layer 700 are consistent with those in Example 1.

[0055] In this embodiment, the first functional layer 800 can be used for antibacterial or antistatic purposes. The first functional layer 800 is a polyethylene layer modified with silver nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

[0056] Specifically, the thickness and selected materials of the first functional layer 800 are consistent with those in Example 2.

[0057] In this embodiment, the second functional layer 900 can be used for anti-fog and / or antifreeze and / or antibacterial purposes. The second functional layer 900 is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; wherein the antibacterial masterbatch is chitosan or sodium alginate.

[0058] Specifically, the thickness and selected materials of the second functional layer 900 are consistent with those in Example 3.

[0059] The first functional layer 800 and the second functional layer 900 can be customized to meet specific needs, giving the composite film more practical functions. By rationally selecting materials for each layer and optimizing the structural design, while ensuring high barrier properties, the use of overly expensive materials and complex production processes is avoided, reducing production costs and improving the product's market competitiveness. Both functional layers can be equipped with an antibacterial layer, further enhancing the composite film's antibacterial properties and ensuring food safety and hygiene.

[0060] Example 5 Reference Figure 5 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a third barrier layer 1000, a fourth adhesive layer 1100 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0061] In this embodiment, the third barrier layer 1000 is a polyethylene naphthalate layer.

[0062] Specifically, the thickness of the third barrier layer 1000 is 5-10 microns; the polyethylene naphthalate (PEN) layer has excellent physical and mechanical properties, gas barrier properties, chemical stability, fatigue resistance, heat resistance, UV resistance, radiation resistance, etc., and excellent insulation properties. It can be recycled through chemical recovery (such as alcoholysis and hydrolysis). It is non-toxic and low-smoke when burned, meeting environmental protection requirements, making it an ideal material to replace PET and some engineering plastics (such as PC and PBT). Its irreplaceable nature in high-end fields has promoted the industry's research and development of environmentally friendly synthesis processes (such as bio-based NDA preparation). PEN is a high-content copolymer copolymerized with polyester, which greatly improves the water and gas barrier properties of the composite film, and has excellent mechanical properties even under high temperature and high pressure conditions.

[0063] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0064] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0065] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 and the third adhesive layer 600 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0066] Specifically, the thicknesses and materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 and the outer layer 700 are consistent with those in Example 1.

[0067] The fourth adhesive layer 1100 is also an ethylene-ethyl acrylate copolymer layer or an ethylene-methacrylic acid copolymer layer; the thickness of the fourth adhesive layer 1100 is 3-5 microns.

[0068] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The various parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film, which further improves the comprehensive barrier performance of the composite film to oxygen, water vapor, odor, etc., has good mechanical strength and flexibility, and has good chemical stability and insulation, heat resistance, UV resistance, and high light transmittance.

[0069] Example 6 Reference Figure 6 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a third barrier layer 1000, a fourth adhesive layer 1100, a first functional layer 800 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0070] In this embodiment, the third barrier layer 1000 is a polyethylene naphthalate layer.

[0071] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0072] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0073] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 , the third adhesive layer 600 and the fourth adhesive layer 1100 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0074] Specifically, the thicknesses and selected materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 , the third barrier layer 1000 , the fourth adhesive layer 1100 and the outer layer 700 are consistent with those in Examples 1 and 5.

[0075] In this embodiment, the first functional layer 800 can be used for antibacterial or antistatic purposes. The first functional layer 800 is a polyethylene layer modified with silver nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

[0076] Specifically, the thickness and selected materials of the first functional layer 800 are consistent with those in Example 2.

[0077] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to obtain the high-barrier multi-layer co-extruded composite film. The effect of the composite film is consistent with that of Example 5, and the first functional layer 800 is used to give the composite film more practical functions.

[0078] Example 7 Reference Figure 7 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a second functional layer 900, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a third barrier layer 1000, a fourth adhesive layer 1100 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0079] In this embodiment, the third barrier layer 1000 is a polyethylene naphthalate layer.

[0080] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0081] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0082] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 , the third adhesive layer 600 and the fourth adhesive layer 1100 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0083] Specifically, the thicknesses and selected materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 , the third barrier layer 1000 , the fourth adhesive layer 1100 and the outer layer 700 are consistent with those in Examples 1 and 5.

[0084] In this embodiment, the second functional layer 900 can be used for anti-fog and / or antifreeze and / or antibacterial purposes. The second functional layer 900 is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; wherein the antibacterial masterbatch is chitosan or sodium alginate.

[0085] Specifically, the thickness and selected materials of the second functional layer 900 are consistent with those in Example 3.

[0086] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to obtain the high-barrier multi-layer co-extruded composite film. The effect of the composite film is consistent with that of Example 5, and the first functional layer 800 is used to give the composite film more practical functions.

[0087] Example 8 Reference Figure 8 A high barrier multi-layer co-extruded composite film comprises, from bottom to top, an inner layer 100, a second functional layer 900, a first adhesive layer 200, a first barrier layer 300, a second adhesive layer 400, a second barrier layer 500, a third adhesive layer 600, a third barrier layer 1000, a fourth adhesive layer 1100 and an outer layer 700; The first barrier layer 300 is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide.

[0088] In this embodiment, the third barrier layer 1000 is a polyethylene naphthalate layer.

[0089] In this embodiment, the inner layer 100 is a linear low-density polyethylene layer or a metallocene polyethylene layer.

[0090] In this embodiment, the outer layer 700 is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

[0091] In this embodiment, the first adhesive layer 200 , the second adhesive layer 400 , the third adhesive layer 600 and the fourth adhesive layer 1100 are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

[0092] Specifically, the thicknesses and selected materials of the inner layer 100 , the first adhesive layer 200 , the first barrier layer 300 , the second adhesive layer 400 , the second barrier layer 500 , the third adhesive layer 600 , the third barrier layer 1000 , the fourth adhesive layer 1100 and the outer layer 700 are consistent with those in Examples 1 and 5.

[0093] In this embodiment, the first functional layer 800 can be used for antibacterial or antistatic purposes. The first functional layer 800 is a polyethylene layer modified with silver nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

[0094] Specifically, the thickness and selected materials of the first functional layer 800 are consistent with those in Example 2.

[0095] In this embodiment, the second functional layer 900 can be used for anti-fog and / or antifreeze and / or antibacterial purposes. The second functional layer 900 is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; wherein the antibacterial masterbatch is chitosan or sodium alginate.

[0096] Specifically, the thickness and selected materials of the second functional layer 900 are consistent with those in Example 3.

[0097] The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to obtain the high-barrier multi-layer co-extruded composite film. The effect of the composite film is consistent with that of Example 5, and the first functional layer 800 and the second functional layer 900 can be customized according to different needs, giving the composite film more practical functions.

[0098] Example 9 Reference Figure 1 , which tests the specific parameters in Example 1: The inner layer 100 is a metallocene polyethylene layer with a thickness of 12 microns; The first adhesive layer 200 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The first barrier layer 300 is a polyvinylidene chloride layer with a thickness of 8 microns; The second adhesive layer 400 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide, with a thickness of 8 microns; The third adhesive layer 600 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The outer layer 700 is a biaxially oriented polypropylene layer with a thickness of 20 microns; The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. Tests have shown that the composite film has an oxygen permeability of less than 5 cm³ / (m²・24h・0.1MPa) and a water vapor permeability of less than 8 g / (m²・24h).

[0099] Example 10 Reference Figure 1 , which tests the specific parameters in Example 1: The inner layer 100 is a linear low-density polyethylene layer with a thickness of 15 microns; The first adhesive layer 200 is made of ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The first barrier layer 300 is an ethylene-vinyl alcohol copolymer layer with a thickness of 6 microns; The second adhesive layer 400 is made of ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide, with a thickness of 6 microns; The third adhesive layer 600 is an ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The outer layer 700 is a biaxially oriented polyester layer with a thickness of 18 microns; The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. Tests have shown that the composite film has an oxygen permeability of less than 8 cm³ / (m²・24h・0.1MPa) and a water vapor permeability of less than 10 g / (m²・24h).

[0100] Example 11 Reference Figure 5 , which is tested for the specific parameters in Example 5: The inner layer 100 is a metallocene polyethylene layer with a thickness of 12 microns; The first adhesive layer 200 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The first barrier layer 300 is a polyvinylidene chloride layer with a thickness of 8 microns; The second adhesive layer 400 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide, with a thickness of 8 microns; The third adhesive layer 600 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The third barrier layer 1000 is a polyethylene naphthalate layer with a thickness of 8 microns; The fourth adhesive layer 1100 is an ethylene-methacrylic acid copolymer layer with a thickness of 3 microns; The outer layer 700 is a biaxially oriented polypropylene layer with a thickness of 20 microns; The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. Tests have shown that the composite film has an oxygen permeability of less than 3 cm³ / (m²・24h・0.1MPa) and a water vapor permeability of less than 5g / (m²・24h).

[0101] Example 12 Reference Figure 5 , which is tested for the specific parameters in Example 5: The inner layer 100 is a linear low-density polyethylene layer with a thickness of 15 microns; The first adhesive layer 200 is made of ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The first barrier layer 300 is an ethylene-vinyl alcohol copolymer layer with a thickness of 6 microns; The second adhesive layer 400 is made of ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The second barrier layer 500 is a polyvinyl alcohol layer modified with nano-silicon dioxide, with a thickness of 6 microns; The third adhesive layer 600 is an ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The third barrier layer 1000 is a polyethylene naphthalate layer with a thickness of 6 microns; The fourth adhesive layer 1100 is made of ethylene-ethyl acrylate copolymer layer with a thickness of 3 microns; The outer layer 700 is a biaxially oriented polyester layer with a thickness of 18 microns; The above-mentioned layers of materials are co-extruded and compounded through a multi-layer co-extrusion blow molding machine. The parameters of the blow molding machine can be adjusted according to actual conditions to produce the high-barrier multi-layer co-extruded composite film. Tests have shown that the composite film has an oxygen permeability of less than 5 cm³ / (m²・24h・0.1MPa) and a water vapor permeability of less than 7 g / (m²・24h).

[0102] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0103] Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in reverse order depending on the functions involved. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Furthermore, features described with reference to certain examples may be combined in other examples.

[0104] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. A high barrier multi-layer co-extruded composite film, characterized in that: From bottom to top, it includes an inner layer (100), a first adhesive layer (200), a first barrier layer (300), a second adhesive layer (400), a second barrier layer (500), a third adhesive layer (600) and an outer layer (700); The first barrier layer (300) is a polyvinylidene chloride layer or an ethylene-vinyl alcohol copolymer layer; The second barrier layer (500) is a nano-silicon dioxide-modified polyvinyl alcohol layer.

2. The high barrier multi-layer co-extruded composite film according to claim 1, characterized in that: A first functional layer (800) is provided between the third adhesive layer (600) and the outer layer (700), and the first functional layer (800) can be used for antibacterial or antistatic purposes; And / or, a second functional layer (900) is provided between the inner layer (100) and the first adhesive layer (200), and the second functional layer (900) can be used for anti-fog and / or anti-freezing and / or antibacterial purposes.

3. The high barrier multi-layer co-extruded composite film according to claim 1, characterized in that: A third barrier layer (1000) is provided between the third adhesive layer (600) and the outer layer (700), and a fourth adhesive layer (1100) is provided between the third barrier layer (1000) and the outer layer (700).

4. The high barrier multi-layer co-extruded composite film according to claim 3, characterized in that: The third barrier layer (1000) is a polyethylene naphthalate layer.

5. The high barrier multi-layer co-extruded composite film according to claim 4, characterized in that: A first functional layer (800) is provided between the fourth adhesive layer (1100) and the outer layer (700), and the first functional layer (800) can be used for antibacterial and / or antistatic properties; And / or, a second functional layer (900) is provided between the inner layer (100) and the first adhesive layer (200), and the second functional layer (900) can be used for anti-fog and / or anti-freezing and / or antibacterial purposes.

6. The high barrier multi-layer co-extruded composite film according to any one of claims 1 to 5, characterized in that: The inner layer (100) is a linear low-density polyethylene layer or a metallocene polyethylene layer.

7. The high barrier multi-layer co-extruded composite film according to any one of claims 1 to 5, characterized in that: The outer layer (700) is a biaxially oriented polypropylene layer or a biaxially oriented polyester layer.

8. The high barrier multi-layer co-extruded composite film according to any one of claims 1 to 5, characterized in that: The first adhesive layer (200), the second adhesive layer (400) and the third adhesive layer (600) are all ethylene-ethyl acrylate copolymer layers or ethylene-methacrylic acid copolymer layers.

9. The high barrier multi-layer co-extruded composite film according to claim 2 or 5, characterized in that: The first functional layer (800) is a polyethylene layer modified with silver nano-titanium dioxide or a polypropylene layer modified with carbon nanotubes.

10. The high barrier multi-layer co-extruded composite film according to claim 2 or 5, characterized in that: The second functional layer (900) is an ethylene-vinyl acetate copolymer layer and / or a polyurethane layer or an acrylic copolymer layer and / or an antibacterial layer obtained by blending ethylene-vinyl acetate copolymer with an antibacterial masterbatch; Wherein, the antibacterial masterbatch is chitosan or sodium alginate.

Images