Integrated composite film, preparation method of integrated composite film, and composite sheet and packaging container using integrated composite film

Abstract

The invention relates to an integrated composite film, a preparation method thereof, and a composite sheet and a packaging container using the integrated composite film. The present invention is used for packaging foodstuffs, in particular liquid foodstuffs, by applying, in one operation, a sealing layer, a treatment layer, a coating layer and a deposition layer (corresponding to the deposition layer and the polymer inner layer of a conventional composite sheet) using an integrated composite film, thereby making it possible to improve the packaging quality of the foodstuffs at a greater fiber ratio by means of a simpler method in the process flow. According to the present invention, a composite sheet having properties, such as oxygen and water vapor permeability and light resistance, which are not inferior to or even superior to those of existing composite sheets is obtained, and thus a packaging container having superior properties is obtained.

Description

Technical Field

[0001] This invention relates to an integrated composite film, its preparation method, and composite sheets and packaging containers using the integrated composite film. Background Technology

[0002] Food, especially liquid food, is often packaged in containers to facilitate its production, transportation and carrying, and to extend its shelf life.

[0003] Common packaging containers include bottles and jars made of glass, ceramic, aluminum (which may have coatings or cladding), and tinplate. Such bottles and jars present numerous drawbacks in production, transportation, and use. For example, the cylindrical shape of the containers makes dense stacking difficult; their relative weight increases energy consumption during transport; they typically require separate packaging plant production, leading to cumbersome transportation between the packaging and filling plants; they require considerable force to open, posing a risk of sharp edges and user injury; and information is difficult to print directly on the container surface, among other issues.

[0004] In view of this, packaging containers made of composite sheets are already widely used in the prior art.

[0005] For example, a packaging container can be manufactured by reforming the laminated packaging material web into a tube by welding the innermost and outermost heat-sealable thermoplastic polymer layers together to join the two longitudinal edges of the web together in an overlapping joint; the tube is filled with liquid food and then separated into individual packages by repeating transverse seals spaced a predetermined distance from each other below the level of the contents; the packages are separated from the tube by cuts along the transverse seals and folded along creases prepared in the packaging material to obtain the desired geometry, typically a parallelepiped or cube.

[0006] For example, packaging containers can also be manufactured by starting with a tubular blank of packaging laminate folded into a flat shape, manufacturing the blank into an open tubular container package to produce packaging, wherein one open end is closed by folding and heat-sealing an integral end panel; the already closed container package is filled with liquid food through its open end, and then the open end is closed by further folding and heat-sealing the corresponding integral end panel.

[0007] Examples of packaging containers made from sheet and tubular preforms are the traditional so-called "mountain-top packaging," as well as packaging with molded tops and / or screw caps made of plastic.

[0008] The aforementioned composite sheet and the method for producing packaging containers using the composite sheet have several advantages. For example, the packaging containers obtained by folding have a cuboid-based shape, making it easy to densely stack the composite sheet and packaging containers; the weight of the packaging containers is much lower than that of the bottles and cans mentioned above, greatly reducing energy consumption during transportation; the production of packaging containers is easier than that of bottles and cans, avoiding the hassle of transportation between the packaging plant and the filling plant; the packaging containers are easier to open, and no sharp edges are formed during the opening process; information is also easier to print directly on the surface of the packaging containers, and so on.

[0009] Common composite sheets have a laminated structure that, from the outside to the inside, includes a carrier layer that provides support and structural stability to the packaging container when filled; a barrier layer that isolates the container from substances such as water and oxygen; and a polymer inner layer that provides liquid tightness to the liquid contained within and heat-sealability of the packaging container. The carrier layer is typically a paper or cardboard layer, the barrier layer is typically an aluminum foil layer, and the polymer inner layer is typically a polyolefin layer, particularly a polyethylene layer. The layers of the composite sheet may also contain other layers; for example, an adhesive layer may be present between the polymer inner layer and the barrier layer to improve adhesion between them.

[0010] It is evident that polymers have multiple functions in composite sheets, making their use unavoidable.

[0011] However, the use of polymers has brought many problems to existing composite sheets and their preparation and use.

[0012] On the one hand, the use of polymers in composite sheets, especially non-degradable polymers such as polyolefins in the inner polymer layers, has led to serious environmental problems. Large amounts of polymer waste are sent to landfills after use and remain undegradable for extended periods. This is determined by the inherent stability of the polymer structure.

[0013] To alleviate or even eliminate the environmental problems caused by recalcitrant polymers, especially polyolefins, an important approach is to reduce the amount of polymers used in composite sheets.

[0014] Therefore, there is an urgent need in the field for a composite sheet that uses an increased proportion of paper and a reduced proportion of plastic, i.e., a higher fiber ratio, to facilitate the recycling of the composite sheet and to have performance that is no less than or even better than existing composite sheets.

[0015] On the other hand, in the preparation of composite sheets, a method is usually adopted to build the composite sheet structure layer by layer starting from the carrier layer, which involves multiple coating operations. As an example of such a preparation method, firstly, an outer layer mainly composed of polymer is applied to the outer surface of the paper layer used as the carrier layer through a first coating process. Then, a laminate mainly composed of polymer is applied to the inner surface of the paper layer through a second coating process. Next, aluminum foil or barrier film, used as a barrier layer, is applied to the laminate through a first adhesive layer. Finally, a second adhesive layer and an inner polymer layer are applied through a third coating process. This method involves three coating operations, has many process steps, and requires significant hardware investment.

[0016] Therefore, there is an urgent need in this field for a simpler method for preparing composite sheets. Summary of the Invention

[0017] This invention relates to an integrated composite film, its preparation method, and composite sheets and packaging containers using the integrated composite film.

[0018] In this invention, a deposited layer corresponding to the barrier layer in prior art composite sheets, a base film corresponding to the polymer inner layer in prior art composite sheets, and a coating layer for enhancing the adhesion between the deposited layer and the base film are introduced into the composite sheet as an integrated composite film in a single operation. Furthermore, the integrated composite film differs in composition from the combination of the polymer inner layer and barrier layer in conventional composite sheets. This invention thus achieves composite sheets with performance comparable to or even superior to existing composite sheets, such as oxygen and water vapor transmittance and light blocking rate, at a higher fiber ratio, through a simpler process flow, thereby obtaining high-performance packaging containers.

[0019] Specifically, as a first aspect of the present invention, the present invention relates to an integrated composite membrane having a total basis weight of 20-60 gsm and comprising, in sequence, a base film, a coating layer and a deposition layer, wherein the base film comprises a sealing layer and a treatment layer, the treatment layer being adjacent to the coating layer.

[0020] Preferably, the coating layer comprises PVA, EVOH, PU or PVDC, and its basis weight is 0.2-2 gsm, more preferably 0.3-1.5 gsm.

[0021] Preferably, the sealing layer has a weight of 10-30 gsm and contains 0-80% mPE and 20-100% LDPE by weight.

[0022] Preferably, the treatment layer has a basis weight of 10-30 gsm and contains 70-100% by weight HDPE, 0-30% by weight LDPE, and 0-30% by weight mPE.

[0023] Preferably, in the integrated composite film, the MI of HDPE is 0.1-8 g / 10 min, more preferably 1-5 g / 10 min, and the density is 0.95-0.975 g / cm³. 3 The preferred concentration is 0.96-0.973 g / cm³. 3 The molecular weight (MI) of LDPE is 0.1-8 g / 10 min, preferably 1-6 g / 10 min, and the density is 0.915-0.93 g / cm³. 3 The preferred concentration is 0.918-0.93 g / cm³. 3 ;

[0024] mPE's T m The optimal temperature range is 90-125℃, preferably 95-120℃, and the density is 0.90-0.918 g / cm³. 3 The preferred concentration is 0.91-0.915 g / cm³. 3 The MI is 0.1-8g / 10min, preferably 1-6g / 10min.

[0025] Preferably, the deposited layer comprises an aluminum layer, an alumina layer, or a silicon dioxide layer, and its thickness is preferably 1-60 nm.

[0026] As a second aspect of the present invention, the present invention relates to a method for preparing the above-mentioned integrated composite film, comprising the following steps: 1a) preparing the base film by multilayer co-extrusion, preferably multilayer co-extrusion blow molding or multilayer co-extrusion stretching; 1b) preferably treating the surface of the treated layer by corona treatment; 1c) preferably forming a coating layer on the surface of the treated layer by solution coating or melt extrusion coating; 1d) preferably forming a deposition layer on the surface of the coating layer by deposition.

[0027] The present invention also relates to an integrated composite membrane prepared by the above method.

[0028] As a third aspect of the invention, the invention relates to a composite sheet for preparing packaging containers, which, in a direction from the outside to the inside, sequentially includes an outer layer, a carrier layer, a laminate layer, an adhesive layer and the aforementioned integrated composite film, wherein the adhesive layer is adjacent to the deposition layer of the integrated composite film.

[0029] Preferably, the laminate has a basis weight of 5-25 gsm, preferably contains 30-100% by weight of HDPE and 0-70% by weight of LDPE, and optionally contains a colorant.

[0030] Preferably, the adhesive layer comprises EAA, EMAA or EMAH, with a basis weight of 2-6 gsm.

[0031] Preferably, in the portion of the composite sheet excluding the integrated composite film, the HDPE has a molecular weight index (MI) of 0.1-15 g / 10 min, preferably 3-10 g / 10 min, and a density of 0.95-0.975 g / cm³. 3 The preferred concentration is 0.96-0.973 g / cm³. 3 ;

[0032] The molecular weight (MI) of LDPE is 0.1-15 g / 10 min, preferably 3-10 g / 10 min, and the density is 0.915-0.93 g / cm³. 3 The preferred concentration is 0.918-0.93 g / cm³. 3 .

[0033] As a fourth aspect of the present invention, the present invention relates to a method for preparing the above-mentioned composite sheet, comprising the following steps: 2a) providing a carrier layer; 2b) forming an outer layer on the outer surface of the carrier layer; 2c) forming a laminate and an adhesive layer on the inner surface of the carrier layer; 2d) applying the integrated composite film onto the surface of the adhesive layer, wherein the deposited layer of the integrated composite film is adjacent to the adhesive layer.

[0034] As a fifth aspect of the invention, the invention relates to a packaging container manufactured from the aforementioned composite sheet or a composite sheet prepared by the aforementioned method.

[0035] As a sixth aspect of the present invention, the present invention relates to a method for manufacturing the above-mentioned packaging container, comprising the following steps: providing the above-mentioned composite sheet or a composite sheet prepared by the above-mentioned method, which includes a first longitudinal edge and a second longitudinal edge;

[0036] Fold the composite sheet and touch and overlap the first longitudinal edge with the second longitudinal edge to obtain a longitudinal seam. Attached Figure Description

[0037] Figure 1 This is a schematic diagram showing the composite sheet structure of the present invention used in Example 1 and the method for preparing the composite sheet of the present invention. The arrows following the steps of the preparation method indicate the direction of application of the prepared structure. For example, "2b)↓" indicates that the layer formed in step 2b) is applied to the inner layer. Detailed Implementation

[0038] the term

[0039] In this document, "a layer consisting essentially of a certain substance" means that the content of said substance in the layer is high enough that the layer exhibits physical and / or chemical properties that a person skilled in the art would consider equivalent to a layer consisting solely of that substance. For example, the content of said substance in the layer may be at least 60% by weight, at least 75% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, or 100% by weight, based on the weight of the layer. The above calculations do not include impurities that are necessarily included.

[0040] In this article, the term "inner side" of a composite sheet or a layer thereof means the side of the composite sheet or layer that is closer to the contents of the packaging container. Correspondingly, the term "outer side" of a composite sheet or a layer thereof means the side of the composite sheet or layer that is closer to the external environment of the packaging container.

[0041] In this document, "layer A 'adjacent' to layer B" means that the surfaces of layers A and B facing each other are in direct contact, or that the surfaces of layers A and B facing each other have only a layer for promoting the bonding of layers A and B, such as the coating layer or adhesive layer in this invention.

[0042] In this article, the "fiber ratio" of a material refers to the percentage of the total weight of fibrous materials. The fiber ratio of existing composite sheets is generally around 70%.

[0043] Polyethylene, LDPE, HDPE and mPE

[0044] Polyethylene is a product of ethylene homopolymerization. Ethylene homopolymerization is usually a free radical polymerization process, and its products are often classified as high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), and metallocene polyethylene (mPE).

[0045] On the one hand, the classification criteria for polyethylene according to density are known to those skilled in the art. For reference, the densities of completely amorphous and completely crystalline polyethylene are 0.880 and 1.000 g / cm³, respectively. 3 .

[0046] Generally, when high pressure (e.g., 82-276 MPa) is used in ethylene polymerization, the density of the resulting polymer is 0.915-0.940 g / cm³. 3 It is classified as LDPE. The reaction is usually carried out at a temperature of 132-332℃, resulting in the formation of a large number of branched structures. Therefore, LDPE has a structure of random long chains with a large number of randomly distributed branched branches. The length of the branched branches is not uniform, but rather has a certain distribution, mainly consisting of 2, 3, or 4 carbon atoms. LDPE is usually a transparent, slightly white, elastic solid.

[0047] According to the definition in ASTM D1248-84, HDPE is a type of polyethylene with a density of 0.940 g / cm³. 3 The above refers to polyethylene. HDPE is obtained through polymerization under low-pressure conditions, such as in the presence of a catalyst, and has a basically linear structure, although a small amount of branching may be intentionally added for specific purposes. The molecular weight distribution of HDPE depends on the catalyst used in the polymerization process and typically has a moderate peak width. HDPE is usually an opaque, white, rigid solid.

[0048] On the other hand, polyethylene includes mPE prepared by polymerization in the presence of a metallocene catalytic system. The metallocene catalytic system comprises a major component of an organometallic compound, typically a Ti or Zr central metal atom positioned between two organic ligands, such as a cyclopentadienyl group, and a minor component of a cocatalyst, typically an organoaluminum compound such as MAO (i.e., methylaluminoxane) or a perfluoroboron aromatic compound. The metallocene catalytic system is a single-active-site catalyst, which, compared to conventional Ziegler-Natta catalysts, can more effectively control the polymer structure, resulting in polyolefins with superior performance. mPE typically has a relatively narrower molecular weight distribution. mPE can be one or more combinations selected from mLDPE (i.e., metallocene low-density polyethylene), mLLDPE (i.e., metallocene linear low-density polyethylene), and mHDPE (i.e., metallocene high-density polyethylene), preferably mLLDPE.

[0049] LDPE, HDPE, and mPE can be prepared by methods known to those skilled in the art. However, more commonly, LDPE, HDPE, and mPE are commercially available. For example, LDPE can be the LDPE series from Dow Chemical (USA), mPE can be the Affinity series from Dow Chemical (USA), and HDPE can be the Rigidex series from Ineos.

[0050] It should be emphasized that the range of HDPE, LDPE, and mPE used in the composite sheets of this invention is known to those skilled in the art and may not be limited to the above description. In other words, given an understanding of the physical / chemical properties and preparation methods of a particular polyethylene, those skilled in the art can easily determine whether it belongs to the HDPE, LDPE, and mPE used in the composite sheets of this invention, without necessarily needing to mechanically refer to the above description.

[0051] Preferably, in the integrated composite film, the MI of HDPE is 0.1-8 g / 10 min, more preferably 1-5 g / 10 min, and the density is 0.95-0.975 g / cm³. 3 The preferred concentration is 0.96-0.973 g / cm³. 3 The molecular weight (MI) of LDPE is 0.1-8 g / 10 min, preferably 1-6 g / 10 min, and the density is 0.915-0.93 g / cm³. 3 The preferred concentration is 0.918-0.93 g / cm³. 3 ;

[0052] mPE's T m The optimal temperature range is 90-125℃, preferably 95-120℃, and the density is 0.90-0.918 g / cm³. 3 The preferred concentration is 0.91-0.915 g / cm³. 3 The MI is 0.1-8g / 10min, preferably 1-6g / 10min.

[0053] Preferably, in the portion of the composite sheet excluding the integrated composite film, the HDPE has a molecular weight index (MI) of 0.1-15 g / 10 min, preferably 3-10 g / 10 min, and a density of 0.95-0.975 g / cm³, preferably 0.96-0.973 g / cm³. 3 ;

[0054] The molecular weight (MI) of LDPE is 0.1-15 g / 10 min, preferably 3-10 g / 10 min, and the density is 0.915-0.93 g / cm³. 3 The preferred concentration is 0.918-0.93 g / cm³. 3 .

[0055] Composition and structure of integrated composite membrane

[0056] A first aspect of the present invention relates to an integrated composite membrane. The integrated composite membrane of the present invention serves as the portion of a composite sheet that contacts the contents of a container.

[0057] The integrated composite membrane of the present invention has a total basis weight of 20-60 gsm and comprises, in sequence, a base film, a coating layer and a deposition layer, wherein the base film comprises a sealing layer and a treatment layer, and the treatment layer is adjacent to the coating layer.

[0058] base membrane

[0059] The base film of the integrated composite film of the present invention corresponds to the polymer inner layer in the prior art, and similarly provides the composite sheet for manufacturing packaging containers with airtightness of the contents contained in the packaging container and heat-sealability of the packaging container.

[0060] The base film of the integrated composite membrane of the present invention includes a sealing layer and a treatment layer, preferably composed of a sealing layer and a treatment layer.

[0061] The sealing layer of the base film is mainly used to provide an airtight seal for the contents of the packaging container and to ensure the heat-sealability of the packaging container.

[0062] Preferably, the sealing layer comprises 0-80 wt% mPE and 20-100 wt% LDPE. For example, the sealing layer may not contain mPE, or may contain 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt% mPE. As another example, the sealing layer may contain only LDPE, comprising 90 wt%, 80 wt%, 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, or 20 wt% LDPE. Obviously, the sum of the contents of all components of the sealing layer must be 100 wt%.

[0063] The sealing layer can also be made primarily of polypropylene (PP).

[0064] Preferably, the weight of the sealing layer is 10-30 gsm, for example, it can be 10 gsm, 15 gsm, 20 gsm, 25 gsm or 30 gsm.

[0065] The base film processing layer is located outside the aforementioned sealing layer and is mainly used to provide a substrate for the outer deposition layer.

[0066] Preferably, the treatment layer comprises 70-100 wt% HDPE, 0-30 wt% LDPE, and 0-30 wt% mPE. For example, the treatment layer may comprise 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or 95 wt% HDPE, or only HDPE. As another example, the treatment layer may not contain LDPE, or may contain 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% LDPE. Yet another example, the treatment layer may not contain mPE, or may contain 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% mPE. Clearly, the sum of the contents of all components in the treatment layer must be 100 wt%.

[0067] Preferably, the weight of the treatment layer is 10-30 gsm, for example, it can be 10 gsm, 12.5 gsm, 15 gsm, 17.5 gsm, 20 gsm, 22.5 gsm, 25 gsm, 27.5 gsm, or 30 gsm.

[0068] When the deposited layer described below cannot achieve sufficient light blocking effect, especially when the deposited layer is not a metallic layer or its thickness is insufficient, the treated layer preferably contains a colorant, such as a colorant added in the form of a color masterbatch.

[0069] sedimentary layer

[0070] The integrated composite film of the present invention further includes a deposition layer. The deposition layer (also known as a barrier layer) primarily functions to isolate, for example, water and oxygen, thereby ensuring the long-term preservation of the contents of the packaging container, especially liquid foods.

[0071] In one embodiment of the present invention, a metal layer, a non-metal layer, a metal oxide layer, or a non-metal oxide layer is used as the deposition layer.

[0072] The metal or nonmetal may be a metal or nonmetal known to those skilled in the art to be suitable for forming the deposited layer, particularly a metal or nonmetal suitable for forming the deposited layer by vapor deposition, such as aluminum. Other metals (e.g., iron, copper, and titanium) or nonmetals (e.g., silicon) may also be used.

[0073] The metal oxide or non-metal oxide may be a metal oxide or non-metal oxide known to those skilled in the art to be suitable for forming a deposited layer, particularly oxides of the aforementioned metals (e.g., aluminum, iron, copper, titanium) or non-metals (e.g., silicon).

[0074] Preferably, the deposited layer of the present invention includes an aluminum layer, an alumina layer, or a silicon dioxide layer.

[0075] Obviously, the deposited layer of the present invention may also include any combination of two or more of the above-mentioned metal layer, non-metal layer, metal oxide layer and non-metal oxide layer.

[0076] Preferably, the thickness of the deposited metal layer, non-metal layer, metal oxide layer or non-metal oxide layer is in the nanometer range, for example, from 1 nm to 60 nm, such as 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm.

[0077] It should be emphasized that the composition, preparation and use of the deposition layer of the present invention are not limited to the contents disclosed above, but any deposition layer known in the art for composite sheets can be used, and the selection of its composition, structure and use method and the adaptive adjustment to the technical solution of the present invention are known to those skilled in the art.

[0078] Coating layer

[0079] The integrated composite membrane of the present invention further includes a coating layer between the treatment layer and the deposition layer of the base membrane. The coating layer mainly serves to enhance the adhesion between the deposition layer and the treatment layer of the base membrane, as well as to act as a barrier.

[0080] In one embodiment of the invention, the coating layer comprises polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyurethane (PU), or polyvinylidene chloride (PVDC).

[0081] Preferably, the weight of the coating layer is 0.2-2 gsm, for example 0.3 gsm, 0.4 gsm, 0.6 gsm, 0.8 gsm, 1 gsm, 1.2 gsm, 1.4 gsm, 1.6 gsm, 1.8 gsm, 2 gsm, and more preferably 0.3-1.5 gsm.

[0082] Preparation method of integrated composite membrane

[0083] A second aspect of the present invention relates to a method for preparing the aforementioned integrated composite film, comprising the following steps: 1a) preparing the base film by multilayer co-extrusion; 1b) treating the surface of the treatment layer; 1c) forming a coating layer on the surface of the treatment layer; and 1d) forming a deposition layer on the surface of the coating layer, thereby obtaining the integrated composite film of the present invention.

[0084] Preparation of base film

[0085] The base film of the present invention can be prepared by multi-layer co-extrusion (preferably multi-layer co-extrusion blow molding or multi-layer co-extrusion stretching).

[0086] In multilayer co-extrusion, the polymers constituting each layer of the base film are melted separately in an extruder, flow through their respective channels, and then converge and extrude in the multilayer co-extrusion die head to obtain a preform with a multilayer structure. Further processing of this preform yields a film with a multilayer structure.

[0087] The specific equipment used in the multi-layer co-extrusion operation, such as the extruder, screw, and multi-layer co-extrusion die head, as well as the conditions used, such as the temperature of each layer in the multi-layer co-extrusion die head, are known to those skilled in the art or can be determined experimentally.

[0088] When the treatment layer contains a colorant, preferably, the colorant is added to the material of the treatment layer in the form of a color masterbatch before multilayer co-extrusion.

[0089] Further processing of the preform with the above-mentioned multi-layer structure can be carried out by blow molding, stretching (e.g., uniaxial stretching and biaxial stretching) or casting, preferably blow molding or stretching.

[0090] For example, in blow molding, compressed air is used to inflate the preform within the mold cavity to form a film with a multi-layered structure, which is then further drawn, wound, and slit.

[0091] The specific equipment used in the blow molding operation, such as blown film devices and cooling devices (e.g., air rings), and the conditions of use are known to those skilled in the art or can be determined experimentally.

[0092] For example, in stretching methods (such as uniaxial stretching and biaxial stretching), the preform is stretched by a certain multiple along the longitudinal direction and / or the transverse direction by a longitudinal stretching machine and / or a transverse stretching machine, then heat-set under tension, and finally the film with a multi-layer structure is cooled, drawn, wound and slit.

[0093] The specific equipment (e.g., longitudinal tensioning machine and transverse tensioning machine) and the conditions used in the stretching method are known to those skilled in the art or can be determined experimentally.

[0094] Treatment of the base film surface

[0095] After the base film is formed, preferably before the winding process, the surface of the base film treatment layer is subjected to surface treatment, preferably corona treatment. In the above corona treatment, a high-frequency high-voltage electric current is applied to the surface of the treatment layer and a low-temperature plasma is generated, which induces the breaking and degradation of the chemical bonds of the molecular molecules on the surface of the treatment layer, thereby generating polar groups (such as carbonyl groups and peroxides), increasing the surface roughness, and may be accompanied by changes in the surface structure (e.g., a reduction in cross-linked structures).

[0096] The specific equipment (e.g., corona processor and discharge rack) and conditions (e.g., electrode gap, processing voltage and power) used in corona treatment are known to those skilled in the art or can be determined experimentally.

[0097] Preparation of coating layer

[0098] The coating layer can be applied to the corona-treated surface of the treatment layer by coating.

[0099] In one embodiment of the invention, coating is achieved using a solution coating method. In solution coating, a solution of the polymer in a suitable solvent is prepared, and the solution is uniformly transferred onto the treatment layer using coating equipment such as a doctor blade, roller, or nozzle, or by techniques such as spin coating. After coating, the solvent is removed, for example, by drying or curing, allowing the polymer to form a continuous and stable film. The solvent is preferably recycled after treatment.

[0100] In another embodiment of the invention, coating is achieved using a melt extrusion coating method. In melt extrusion coating, an extrusion operation is first performed using an extrusion tool known to those skilled in the art. The extrusion tool used can be commercially available, such as an extruder, preferably a screw extruder. The extruder preferably has an opening at its end, through which molten polymer agglomerates are extruded onto the treatment layer, thereby obtaining a layer of polymer superimposed on the treatment layer. During the extrusion process, the polymer is typically heated to a temperature, for example, 210-350°C, and measured at the molten polymer film below the extruder die exit.

[0101] After the molten polymer layer is applied to the treatment layer by the above method, the molten layer can be cooled for heat setting purposes. This cooling is preferably achieved by contact with a surface at a temperature maintained at 5-50°C, more preferably 10-30°C.

[0102] Subsequently, at least the sides are separated from the surface. This separation can be performed in any manner well known to those skilled in the art and seemingly suitable, in order to separate the flanks quickly, as accurately as possible, and cleanly. Preferably, the separation is performed by a knife, a laser beam, or a water jet, or a combination of two or more of these.

[0103] The specific equipment and conditions used in solution coating and melt extrusion coating are known to those skilled in the art or can be determined experimentally.

[0104] Preparation of sedimentary layers

[0105] A deposition layer can be created by vapor deposition (e.g., physical vapor deposition or chemical vapor deposition) of a metal, non-metal, metal oxide, or non-metal oxide used to form the deposition layer onto the surface of the coating layer.

[0106] In physical vapor deposition (PVD), under vacuum conditions, such as by heating or bombarding a target with high-energy ions, a vapor of the target material is generated, transported, and deposited onto the surface of a substrate to obtain a film of the target material on the substrate. Common PVD methods include vacuum evaporation deposition, vacuum sputtering deposition, and vacuum ion deposition.

[0107] For example, in one embodiment of the present invention, an aluminum layer as the deposition layer of the present invention is formed by vacuum evaporation deposition, wherein, under vacuum conditions, aluminum as a target material is heated to a high temperature by, for example, resistance heating to generate aluminum vapor, and the aluminum vapor is transported to the surface of the base film coating layer to form an aluminum film.

[0108] For example, in one embodiment of the present invention, an aluminum layer as the deposition layer of the present invention is formed by vacuum sputtering deposition. For example, under vacuum conditions filled with argon gas, argon atoms are ionized into argon ions by argon glow discharge. The argon ions are accelerated under the action of electric field force and bombard the aluminum as the target material, causing the atomic aluminum to be sputtered from the surface of the target material, transferred and deposited on the surface of the base film coating layer, thereby forming an aluminum film.

[0109] In chemical vapor deposition, reactants that can react to form a substance deposited on a target material undergo a chemical reaction under gaseous conditions or on a substrate to generate a solid material deposited on the target material.

[0110] For example, in one embodiment of the present invention, aluminum metal-organic compounds are vaporized and then introduced into a reaction chamber using a carrier gas, typically argon, to react chemically with oxygen and deposit the reaction products onto the surface of the base film coating layer, thereby forming an aluminum oxide film.

[0111] The specific equipment and conditions used in the vapor deposition of the sedimentary layer are known to those skilled in the art or can be determined experimentally.

[0112] After the deposition layer is formed on the base film, the product can be further processed, such as winding and slitting, to obtain an integrated composite film as a separate product.

[0113] Composition and structure of composite sheets

[0114] A third aspect of the present invention relates to a composite sheet for preparing a packaging container, which comprises, in sequence from the outside to the inside, an outer layer, a carrier layer, a laminate layer, an adhesive layer and the aforementioned integrated composite film, wherein the adhesive layer is adjacent to the deposition layer of the integrated composite film of the present invention.

[0115] carrier layer

[0116] The composite sheet of the present invention first includes a carrier layer. The carrier layer plays a supporting role in the composite sheet, providing structural stability of the packaging container made from the composite sheet in a full state.

[0117] The carrier layer commonly used in the prior art can be used as the carrier layer of this invention.

[0118] In one embodiment of the invention, the carrier layer comprises a paper layer or a paperboard layer. The paper layer or paperboard layer is produced by depositing a suspension of appropriately treated (e.g., pulped) plant fibers, mineral fibers, animal fibers, chemical fibers, preferably plant fibers, or mixtures thereof onto a forming apparatus and then drying it. The plant fibers may be, for example, coniferous wood fibers obtained from Masson pine, larch, red pine, and spruce, and broadleaf wood fibers, for example, obtained from birch, poplar, linden, eucalyptus, and maple, or combinations thereof.

[0119] The plant fibers of the present invention can be obtained, for example, in the form of wood mechanical pulp, chemical pulp, and mechatronic pulp. Wood mechanical pulp is produced by mechanical pulping, for example, pressing wood segments lengthwise onto a moist, rough, uniformly rotating millstone to separate the fibers from the wood segments, followed by screening and concentration to produce pulp. Wood chemical pulp is produced by chemical pulping, for example, immersing wood chips in an aqueous solution of a chemical, such as a mixture of sodium hydroxide and sodium sulfide, and cooking them under high temperature and pressure to dissolve the lignin in the wood chips, obtaining intact cellulose. Wood chemimechanical pulp is produced by a semi-chemical pulping method combining chemical and mechanical methods, for example, first locally softening or cooking the wood chips with chemicals, and then completing the gelatinization process mechanically.

[0120] The obtained cellulose is made into wet pulp and applied to a forming device, where it is dried to obtain paper or paperboard layers. Paper or paperboard layers can also be obtained by laminating multiple identical or different layers.

[0121] The paper layer or paperboard layer can be in the form of a paper layer or paperboard layer prepared as described above, or it can be wound on a reel to obtain a curled state from the storage reel, and unwound to obtain an unfolded form when in use.

[0122] Of course, paper or cardboard layers can also be obtained as commodities.

[0123] The paper or paperboard layer of the present invention may have a covering layer on one or both sides to improve the physicochemical properties of the paper or paperboard layer or to provide a specific function. For example, the outermost layer of the paper or paperboard layer may have a printed layer to provide patterns or information displayed on the outer surface of the packaging container.

[0124] In another embodiment of the invention, the carrier layer comprises a paperboard layer. Preferably, the paperboard layer has a single-layer or multi-layer structure and may have one, two, or more outer layers on one or two sides. For example, the paperboard layer may comprise a face layer, a core layer, and a bottom layer in order from the outside to the inside.

[0125] Preferably, the basis weight of the carrier layer of the present invention can be from 120 to 450 g / m³. 2 Preferred concentration: 130 to 400 g / m 2 Choose 150 to 380g / m 2 .

[0126] It should be emphasized that the composition, preparation and use of the carrier layer of the present invention are not limited to the contents disclosed above, but any carrier layer known in the art for composite sheets can be used, and the selection of its composition, structure and usage method and the adaptive adjustment to the technical solution of the present invention are known to those skilled in the art.

[0127] outer layer

[0128] In one embodiment of the invention, the composite sheet may include an outermost layer intended to contact the external environment of the packaging container made from the composite sheet. Preferably, the outer layer is liquid-tight. This outer layer may, for example, be a layer substantially composed of LDPE.

[0129] laminate

[0130] In one embodiment of the invention, the composite sheet of the invention may include a laminate layer on the inner surface of the carrier layer. This laminate layer is intended for laminating the carrier layer (such as a cardboard layer) and the deposited layer of the integrated composite film of the invention together.

[0131] Preferably, the weight of the laminate is 5-25 gsm, for example 5 gsm, 10 gsm, 15 gsm, 20 gsm or 25 gsm.

[0132] Preferably, the laminate contains 30-100% by weight of HDPE, such as 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% by weight of HDPE.

[0133] Furthermore, the laminate preferably contains 0-70% by weight of LDPE, for example, no LDPE, or contains 10%, 20%, 30%, 40%, 50%, 60%, or 70% by weight of LDPE.

[0134] For example, when the deposited layer cannot achieve sufficient light blocking effect, especially when the deposited layer is not a metallic layer or its thickness is not large enough, the laminate preferably contains a colorant, such as a colorant added in the form of a color masterbatch.

[0135] Adhesive layer

[0136] The inner side of the laminate has an adhesive layer to further improve the adhesion between the layers on both sides (i.e., the laminate and the deposited layer of the integrated composite membrane).

[0137] The adhesive for this bonding layer can be a polyolefin-based adhesive, i.e., primarily composed of polyolefin monomer units (e.g., polyethylene monomer units). Preferably, it has a melt flow index of 4 to 12 g / 10 min at 190°C and 2.16 kg (measured according to ISO-1133), and a carboxyl functional group content of 3 to 10% by weight.

[0138] Preferably, the adhesive is an ethylene-(meth)acrylic acid copolymer or a graft copolymer, such as ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), or ethylene-methacrylic acid-maleic anhydride copolymer (EMAH).

[0139] Preferably, the weight of the adhesive layer is 2-6 gsm, for example 2 gsm, 3 gsm, 4 gsm, 5 gsm or 6 gsm.

[0140] The composite sheet of the present invention may optionally include other layers to impart specific properties to the composite sheet. The composition, structure, and preparation of these other layers, as well as their adaptation to the technical solutions of the present invention, are known to those skilled in the art.

[0141] Preparation of composite sheets

[0142] A fourth aspect of the present invention relates to a method for preparing the composite sheet of the present invention.

[0143] Once the composition and structure of the composite sheet of the present invention are clarified, those skilled in the art can easily obtain the method for preparing the above-mentioned composite sheet from the prior art.

[0144] In one embodiment of the present invention, the integrated composite film of the present invention and the remaining portion of the composite sheet are first formed respectively, and then the integrated composite film is laminated onto the surface of the adhesive layer of the composite sheet, wherein the deposited layer of the integrated composite film is adjacent to the adhesive layer.

[0145] For example, an outer layer can be formed on the outer surface of the carrier layer (preferably by extrusion coating), and then a laminate and an adhesive layer can be formed on the inner surface of the carrier layer (preferably by multilayer co-extrusion coating), and finally the pre-prepared integrated composite film can be laminated on the surface of the adhesive layer.

[0146] For example, in the extrusion coating operation of the outer layer, polymer melt is extruded through an opening, preferably in the shape of a funnel groove, at the end of the extruder barrel and applied to the precursor. Subsequently, preferably, the layer of polymer, still in a molten state, is stretched along a uniaxial direction to achieve polymer orientation in this direction. The melt layer can be cooled to achieve heat setting, preferably by quenching through contact with a surface. The specific equipment and conditions used in the extrusion coating are known to those skilled in the art or can be determined experimentally.

[0147] For example, in the multilayer co-extrusion coating operation of the laminate and adhesive layers, the materials constituting each layer are transferred to the die using a feed block, and then each layer is applied to the precursor in a manner similar to extrusion coating, that is, the melt leaves the die through the die gap (e.g., a die gap of 500 mm in length and 1 mm in width) and is applied to the inner surface of the carrier layer that is moving relative to the die gap, thereby forming multiple layers.

[0148] When the laminate contains a colorant, preferably, the colorant is added to the material of the laminate in the form of a color masterbatch before the multilayer co-extrusion coating of the laminate and the adhesive layer.

[0149] Finally, the pre-prepared integrated composite film is pressed onto the surface of the adhesive layer.

[0150] Obviously, the above description is merely exemplary, and those skilled in the art can also use other methods to obtain the composite sheet of the present invention.

[0151] Packaging containers and their manufacturing methods

[0152] As a fifth and sixth aspect, the present invention also relates to a packaging container made from the composite sheet of the present invention and a method for manufacturing the packaging container.

[0153] Packaging containers can be manufactured from the composite sheets of the present invention using methods known to those skilled in the art.

[0154] In one embodiment of the present invention, a basic method for manufacturing a packaging container includes the following steps: providing a composite sheet of the present invention, which includes a first longitudinal edge and a second longitudinal edge located on opposite sides of the composite sheet; folding the composite sheet such that the first longitudinal edge contacts and overlaps the second longitudinal edge, thereby obtaining a longitudinal seam.

[0155] In a preferred embodiment of the invention, the packaging container is a cubic container, also known as a "brick-shaped" container. In the manufacture of this cubic container, the composite sheet of the invention, comprising a first longitudinal edge and a second longitudinal edge located on opposite sides of the composite sheet, is first folded as described above, such that the first longitudinal edge contacts and overlaps the second longitudinal edge, thereby obtaining a longitudinal seam, thus producing a jacket-shaped container precursor. This container precursor is then transported to a commercial filling machine, where the bottom region of the container is created by folding and sealed, for example, by blowing with hot air. The contents (e.g., liquid food) are then filled into the container with the bottom region, and the top region of the container is created by further folding. The container is then sealed and closed, for example, by ultrasonic sealing, thereby obtaining a packaging container filled with the contents.

[0156] The steps, conditions, and equipment involved in the method for manufacturing packaging containers from composite sheets of the present invention can be determined by those skilled in the art based on actual needs.

[0157] Technical effect

[0158] This invention utilizes an integrated composite film to apply a sealing layer, a treatment layer, a coating layer, and a deposition layer (corresponding to the deposition layer and polymer inner layer of conventional composite sheets) in a single operation. This allows for a simpler process flow and, at a greater fiber ratio, a composite sheet with performance comparable to or even superior to that of existing composite sheets, such as oxygen and water vapor transmittance and light blocking rate. Consequently, a high-performance packaging container is obtained.

[0159] Example

[0160] The technical solutions and effects of the present invention will be described in more detail below with reference to embodiments. Obviously, the following embodiments only relate to some, and not all, of the technical solutions of the present invention. The scope of the present invention should be defined by the appended claims, and not limited to the technical solutions described in the specification, much less limited to the following embodiments.

[0161] Raw materials for integrated composite films and composite sheets

[0162] The HDPE used to prepare the treatment layer and sealing layer is Elite5960G1 from Dow Chemical in the United States, the LDPE is LDPE 450E from Dow Chemical in the United States, and the mPE is Affinity 1845G from Dow Chemical in the United States.

[0163] The PVA used to prepare the coating was from Michelman in the United States, and the PU and EVOH were from BASF in Germany.

[0164] The EAA, EMAA, and EMAH used to prepare the adhesive layer were sourced from Dow Chemical in the United States.

[0165] The HDPE used to prepare the laminate and outer layer is Rigidex HD6070FA from Ineos Group in Switzerland, and the LDPE is LDPE 2420K from PTT Public Company Limited in Thailand.

[0166] The cardboard used as the carrier layer comes from Stora Enso, a company in Finland.

[0167] Preparation of integrated composite membranes and composite sheets

[0168] Follow the methods below, such as Figure 1 As shown, an integrated composite membrane is prepared, and a composite sheet is further prepared:

[0169] 1a) The materials of sealing layer 1 and treatment layer 2 are co-extruded and blown in multiple layers using a German Hosokawa Alpine blown film equipment. The extruder temperature of the blown film machine is 170°C, the die temperature is 165°C, and the linear speed is 65m / min. Before winding, the outer surface of treatment layer 2 is subjected to online corona treatment so that the surface dyne value of treatment layer is greater than 38, thereby preparing a base film 9 composed of sealing layer 1 and treatment layer 2.

[0170] 1b) The material of coating layer 3 was applied to the outer surface of base film treatment layer 2 using an Italian Bobst coating machine at a speed of 150 m / min and a drying temperature of 90 °C, thereby preparing coating layer 3;

[0171] 1c) The material of the deposition layer 4 is applied to the outer surface of the coating layer 3 using the Italian Bobst true plating equipment at a speed of 500 m / min, thereby preparing the deposition layer 4 and obtaining the integrated composite film 10.

[0172] 2a) Provide paperboard as carrier layer 5;

[0173] 2b) The material of the outer layer 6 was extruded and coated onto the outer surface of the carrier layer 5 using a Davis Standard coating machine from the United States at a temperature of 320°C and a coating machine speed of 500 m / min, thereby preparing the outer layer 6;

[0174] 2c) Using a Davis Standard coating machine, the materials of the laminate 7 and the adhesive layer 8 are co-extruded and coated onto the inner surface of the carrier layer 5, wherein the laminate 7 is in direct contact with the inner surface of the carrier layer 8, the temperature is 300°C, and the coating machine speed is 500 m / min, thereby preparing the laminate 7 and the adhesive layer 8; at the same time, the integrated composite film 10 obtained in step 1c) is laminated onto the inner surface of the adhesive layer 8, wherein the adhesive layer 8 is in direct contact with the deposited layer 4 obtained in step 1c), thus obtaining the composite sheet 11.

[0175] Manufacturing of packaging containers

[0176] The composite sheet is folded and sealed to manufacture a cubic (“brick”) packaging container as follows: The composite sheet is folded so that its two longitudinal edges meet and overlap to create a longitudinal seam, and the longitudinal seam is sealed to create a jacket-shaped packaging container precursor; the jacket-shaped packaging container precursor is transported to a commercial filling machine, the bottom area of ​​the packaging container is created by folding, and the bottom is sealed by blowing hot air at a temperature of 300°C; the packaging container is filled with water, the top area of ​​the packaging container is created by further folding, and the top area is closed by ultrasonic sealing.

[0177] Oxygen permeability test method

[0178] The oxygen permeability (i.e., oxygen permeability) of the composite sheet was determined using the test method in GB / T 1038.2-2002 "Test methods for gas permeability of plastic films and sheets - Part 2: Isobaric method" under the following test conditions: 23°C and 50% humidity.

[0179] Test method for water vapor transmission rate

[0180] The water vapor transmission rate of the composite sheet was determined using the test method in GB / T 26253-2010 "Determination of vapor transmission rate of plastic films and sheets by infrared detector method" under the conditions of 40℃ and 90% humidity.

[0181] Methods for testing light obscuration

[0182] The light blocking rate of the composite sheet was determined using the test methods in GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics".

[0183] Forming coefficient

[0184] The forming factor is one of the parameters that comprehensively characterizes packaging containers or composite sheets used to manufacture packaging containers. The definition and test method for the forming factor of packaging containers are disclosed in CN107434065A. The forming factor of packaging containers is determined according to the method described in CN107434065A.

[0185] Sealing strength

[0186] The sealing strength of the top and bottom of the packaging container was determined using the test methods in GB / T 18192-2008 "Paper-based composite materials for aseptic packaging of liquid food".

[0187] Examples 1-6

[0188] The integrated composite membrane was prepared according to the composition in Tables 1 and 2 and the preparation method of the integrated composite membrane and composite sheet described above, and the composite sheet was further prepared. Taking the composition of the sealing layer in Example 1 as an example, "LDPE / mPE 40%" refers to a mixture of LDPE and mPE, wherein mPE is 40% by weight.

[0189] The oxygen transmittance, water vapor transmittance, and light blocking rate of the composite sheet and the integrated composite membrane were measured, and the results are shown in Tables 1 and 2.

[0190] For Examples 1-3, packaging containers were manufactured according to the method described above, and the forming factor, top seal strength, and bottom seal strength were determined. Testing showed that the top seal strength of the packaging containers was less than the bottom seal strength, and the top seal strength was in the range of 11-26 N, while the forming factor was in the range of 1.0-10.0 m. 2 Within the range of / kg.

[0191] List of reference numerals in the attached diagram:

[0192] 1. Sealing layer

[0193] 2 Processing layer

[0194] 3. Coating layer

[0195] 4. Sedimentary layer

[0196] 5. Carrier layer

[0197] 6 Outer layer

[0198] 7-Laminated Layer

[0199] 8. Adhesive layer

[0200] 9. Base film

[0201] 10 Integrated composite membrane

[0202] 11 Composite Sheets

[0203] 1a) A sealing layer and a treatment layer are prepared by multi-layer co-extrusion blow molding and corona treatment.

[0204] Thus, a base film is obtained.

[0205] 1b) Prepare a coating layer by melt extrusion coating 1c) Prepare a deposited layer by vacuum deposition, thereby obtaining an integrated composite film 2a) Provide paperboard

[0206] 2b) The outer layer is prepared by extrusion coating. 2c) The laminate and adhesive layer are prepared by multilayer co-extrusion coating, and then...

[0207] By applying an integrated composite membrane, a composite sheet is obtained.

[0208]

[0209]

Claims

1. An integrated composite film having a total grammage of 20 to 60 gsm and comprising in succession a base film, a coating layer and a deposition layer, wherein the base film comprises or preferably consists of a sealing layer and a treatment layer, the treatment layer being adjacent to the coating layer.

2. The integrated composite film of claim 1, wherein the coating layer comprises PVA, EVOH, PU or PVDC, preferably in a grammage of 0.2 to 2 gsm, preferably 0.3 to 1.5 gsm.

3. The integrated composite film of claim 1 or 2, wherein the sealing layer has a grammage of 10 to 30 gsm and comprises 0 to 80 wt.% of mPE and 20 to 100 wt.% of LDPE.

4. The integrated composite film of any of the preceding claims, wherein the treatment layer has a grammage of 10 to 30 gsm and comprises 70 to 100 wt.% of HDPE, 0 to 30 wt.% of LDPE and 0 to 30 wt.% of mPE.

5. The integrated composite film of any of the preceding claims, wherein the deposition layer comprises an aluminum layer, an aluminum oxide layer or a silicon dioxide layer, preferably having a thickness of 1 to 60 nm.

6. The integrated composite film of any of the preceding claims, wherein HDPE has an MI of 0.1 to 8 g / 10 min, preferably 1 to 5 g / 10 min, and a density of 0.95 to 0.975 g / cm 3 , preferably 0.96 to 0.973 g / cm 3 ; The LDPE has an MI of 0.1 to 8 g / 10 min, preferably 1 to 6 g / 10 min, and a density of 0.915 to 0.93 g / cm 3 , preferably 0.918 to 0.93 g / cm 3 ; T m is 90 to 125°C, preferably 95 to 120°C, and the density is 0.90 to 0.918 g / cm 3 , preferably 0.91 to 0.915 g / cm 3 , and the MI is 0.1 to 8 g / 10 min, preferably 1 to 6 g / 10 min.

7. A process for the production of an integrated composite film according to any of the preceding claims, comprising the following steps: 1a) producing the base film by multilayer co-extrusion, preferably multilayer co-extrusion blowing or multilayer co-extrusion stretching; 1b) treating the surface of the treatment layer, preferably by corona treatment; 1c) forming a coating layer on the surface of the treatment layer, preferably by solution coating or melt extrusion coating; 1d) forming a deposition layer on the surface of the coating layer, preferably by deposition.

8. An integrated composite film produced by the process of claim 7.

9. A composite sheet for the production of a packaging container comprising in succession in a direction from the outside to the inside an outer layer, a carrier layer, a lamination layer, an adhesive layer and an integrated composite film according to any of claims 1 to 6 and claim 8, wherein the adhesive layer is adjacent to the deposition layer of the integrated composite film.

10. The composite sheet of claim 9, wherein the lamination layer has a grammage of 5 to 25 gsm, preferably comprises 30 to 100 wt.% of HDPE and 0 to 70 wt.% of LDPE and optionally comprises a colorant.

12. The composite sheet of any of claims 9-11, wherein, 11. The composite sheet of claim 9 or 10, wherein the adhesive layer comprises EAA, EMAA or EMAH, preferably in a grammage of 2 to 6 gsm. HDPE has an MI of 0.1 to 15 g / 10 min, preferably 3 to 10 g / 10 min, and a density of 0.95 to 0.975 g / cm 3 , preferably 0.96 to 0.973 g / cm 3 ; The LDPE has an MI of 0.1 to 15 g / 10 min, preferably 3 to 10 g / 10 min, and a density of 0.915 to 0.93 g / cm 3 , preferably 0.918 to 0.93 g / cm 3 .

13. A method of making the composite sheet of any of claims 9-12, comprising the steps of: in the part of the composite sheet other than the integrated composite film, 2a) providing a carrier layer; 2b) forming an outer layer on the outer side surface of the carrier layer, preferably by extrusion coating; 2c) forming a lamination layer and an adhesive layer on the inner side surface of the carrier layer, preferably by multilayer co-extrusion coating; 2d) applying the integrated composite film to the surface of the adhesive layer by compounding, preferably lamination, wherein the deposition layer of the integrated composite film is adjacent to the adhesive layer.

14. A packaging container produced from the composite sheet of any of claims 9 to 12 or from the composite sheet produced by the process of claim 13.

15. A method of manufacturing the packaging container of claim 14, comprising the steps of: providing the composite sheet of any one of claims 9-12 or the composite sheet made by the method of claim 13, which comprises a first longitudinal edge and a second longitudinal edge; folding the composite sheet, and contacting and overlapping the first longitudinal edge to the second longitudinal edge, thereby obtaining a longitudinal seam.

16. The method of claim 15, wherein the first longitudinal edge is contacted and overlapped to the second longitudinal edge by means of a heat seal.

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