• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    POLYMERIC FILM, THERMOMECHANICALLY STABLE, HEAT-SELABLE, LAMINATE PACKAGING, PACKAGING CONTAINER FOR LIQUIDS, AND METHODS FOR THE MANUFACTURE OF POLYMERIC FILM The invention relates to a polymeric film with barrier coating applied by vapor deposition, sealable heat and thermomechanically stable, consisting substantially of polymers based on polyethylene. The invention relates especially to that metallized polymeric film. The invention also relates to a packaging laminate containing the vapor-deposited polymer film and a packaging container produced from that packaging laminate. The invention further relates to a method for producing the stable, heat-sealable coated polymeric film and to the method of manufacturing a packaging laminate that includes the heat-sealable film.
    公开号:BR112012005433B1
    申请号:R112012005433-3
    申请日:2010-09-09
    公开日:2021-03-02
    发明作者:Gil Rochat；Alain Bonnebault；Monika Bürki；Cesare Lorenzetti
    申请人:Tetra Laval Holdings & Finance Sa；
    IPC主号:
    专利说明:

    TECHNICAL FIELD OF THE INVENTION
    [001] The present invention relates to a polymeric film with vapor deposition barrier coating, heat sealable and thermomechanically stable, consisting mainly of polyethylene polymers, especially a metallized film. The invention also relates to a packaging laminate containing the vapor-deposited coated polymeric film and a packaging container produced from that packaging laminate. The invention further relates to a method for producing the thermomechanically stable heat-sealable polymeric film. BACKGROUND OF THE INVENTION
    [002] Single-use, disposable packaging containers for liquid foods are often produced from a packaging laminate based on cardboard or paperboard. One of these commonly used packaging containers is marketed under the trade name Tetra Brik Aseptic® and is mainly used for aseptic packaging of liquid foods such as milk, fruit juices, etc., sold for storage under long-term ambient conditions. The packaging material for this known packaging container is typically a laminate containing a bulky core layer of paper or cardboard and outer, liquid-tight, thermoplastic layers. In order to make the packaging container gas-tight, in particular oxygen-tight packaging, for example, for the purpose of aseptic packaging and packaging of milk or fruit juice, the laminate of these packaging containers usually includes at least one additional layer, plus commonly an aluminum foil.
    [003] Inside the laminate, ie on the side designed to be in contact with the food from a container produced from the laminate, there is an inner layer, applied over the aluminum foil, this inner layer being made up of one or more layers, including heat sealable adhesive polymers and / or polyolefins. Also on the outer side of the core layer, there is an outer heat-sealable polymer layer. The heat-sealable polymeric layers are preferably based on low density ethylene polymers, to provide a reliable and fast sealing process of the packaging material inside the packaging containers. Low density ethylene polymers suitable for heat sealing are polyethylene with densities less than 0.940 g / cm3, including low density polyethylene (LDPE) which has a density in the range 0.910 - 0.940 g / cm3, low density linear polyethylene (LLDPE) or variants thereof, for example metallocene catalyzed LLDPE (m-LLDPE). Packaging having outer layers of these low density ethylene polymers is easy to seal in a fast and reliable thermal sealing process in strong and durable packaging containers.
    [004] Packaging containers are generally produced using modern high-speed packaging machines of the type that continuously form, fill and seal packages from a fabric or from prefabricated blanks of packaging material, for example packaging machines of the Tetra Brik Aseptic® type. Packaging containers can then be produced by forming a sheet of laminated material in a tube, by joining the two longitudinal ends of the screen together by overlapping the inner and outer thermoplastic polymer layers, which are sealable layers for heat. The tube is filled with the desired liquid food product and is then divided into individual packages by repeated transverse seals of the tube at a predetermined distance from each other below the level of the tube content. The packages are separated from the tube by incisions along the transverse seals and they are given the desired geometric configuration, usually in the form of a brick by the formation of folds along the crease lines in the packaging material.
    [005] The main advantage of this concept of continuous packaging method including forming, filling and sealing is that the mesh can be continuously sterilized just before the tube is formed, thus providing the possibility of an aseptic packaging method, ie a method in which the liquid to be packaged, as well as the packaging material itself is low in bacteria and the filled packaging container is produced in clean circumstances so that the filled packaging can be stored for a long time even at room temperature, without the risk of growth of microorganisms in the packaged product. Another important advantage of the Tetra Brik® packaging method, indicated above, is the possibility of continuous packaging at high speed, which has a considerable impact on cost efficiency.
    [006] A layer of aluminum film on the packaging laminate provides barrier properties far superior to most polymeric barrier materials. Conventional aluminum film-based packaging laminate for aseptic liquid food packaging is the most cost-efficient packaging material in its level of performance available on the market today. Any other material to compete with this must be more cost-effective compared to raw materials, have comparable food preservation properties and have a comparatively low complexity in converting to a finished packaging laminate.
    [007] Until now there is hardly any aseptic packaging based on paper or cardboard for long-term storage in ambient conditions of the type described above available on the market, which is manufactured from a cost-efficient packaging laminate without laminates with aluminum film that has reliable properties and food preservation properties for more than three months.
    [008] Among efforts to develop more cost-efficient packaging materials and minimize the amount of raw material needed to manufacture these packaging materials, there is a general incentive for the development of prefabricated films having multiple barrier features, which can replace the aluminum film. Examples of such films already known are films that combine multiple layers in which each contributes with complementary barrier properties to the final film, for example, films having a vapor-deposited barrier layer and another polymer-based barrier layer coated on the same substrate film. These films, which have been coated at least twice with different coating methods, however, tend to become very expensive and involve very high demands on the qualities of the substrate film, such as thermal resistance and durability in handling.
    [009] On the other hand, in order to optimize the packaging laminate, its production and the packaging container, there is an incentive to, in addition to reducing raw material costs, simplifying the structure of the packaging laminate, reducing the number of necessary conversion steps and, at the same time, provide a packaging laminate that has sufficient barrier and food preservation properties.
    [0010] Another method of including two functionalities in the same film, is to include a heat sealable layer for thermally sealing a packaging material in the film on the first side, and a barrier layer on the other side. An example of such a film is known from previously filed international patent application No. WO-A-2006/027662, which describes a polymeric film containing a SiOx gas barrier coating coated on a first side of a polymeric support layer also having a polyolefin layer arranged on a second side of said polymeric support layer. It also describes packaging laminates made from it and packaging containers in which the heat-sealable polyolefin layer is in direct contact with their contents. It also discloses a method for producing a polymeric film that includes a SiOx gas barrier coating, a method that includes the steps of: a) forming a polymeric support layer and a heat sealable polyolefinic layer and joining these layers to form a intermediate film; b) apply said SiOx coating directly to said polymeric support layer, to form said film, and preferably, after step (a) but before step (b), perform an intermediate orientation step, preferably mono-orientation , of said intermediate stretch film.
    [0011] The polymeric support layer is exemplified as a polymer based on polyamide or polyester, preferably a polyamide, because it adds some barrier properties in itself and provides a good receiving surface and thermomechanical properties for subsequent coating with SiOx.
    [0012] This SiOx-coated film is, however, more difficult to manufacture since the film incorporates two different types of polymer such as polyamide or polyester on one side of the backing film and polyethylene on the other side of the film, which results in tensions and less compatible thermal behavior between the layers of the interior of the film. This requires a lot of the manufacturing process to provide sufficiently reliable barrier and integrity properties and adds, contrary to what was intended, a lot of complexity in the process of converting materials as a whole. OBJECT OF THE INVENTION
    [0013] It is, therefore, an objective of the present invention to provide a thermomechanically stable heat sealable polymer film with a vapor deposition applied barrier coating and a packaging laminate that helps to alleviate the disadvantages and problems discussed above and that fulfills at least some of the above requirements, preferably all of them.
    [0014] Thus, it is an objective of the present invention to provide a thin substrate polymeric film, prefabricated, thermomechanically stable and heat sealable, which is coated by vapor deposition, preferably metallized, with a barrier layer, suitable for use in a packaging laminate / container, whose vapor deposition coated substrate film combines a desired barrier property, such as gas barrier, water vapor barrier or non-scraping barrier, a heat-sealable low density ethylene polymer layer included in the polymeric substrate film, a high resistance and thermomechanical stability in the coating and lamination of the film and lower costs.
    [0015] A packaging laminate containing the vapor-deposited heat-sealable polymeric film of the invention is suitable for aseptic packaging and long-term storage, and has sufficient flexural rigidity and thermomechanical stability to be suitable for continuous, high-throughput packaging. speed of liquid food using a continuous tube forming and heat sealing method.
    [0016] The invention also relates to a packaging container, with good integrity, ie resistant to leakage through seals and joints, filled with liquid or liquid (a) or semi-liquid (a) food or drink and produced from the packaging laminate containing the heat sealable polymeric film of the invention.
    [0017] These and other objectives are achieved by means of the thermomechanically stable, heat-sealable polymeric film, coated with a vapor deposition barrier layer, the packaging laminate and the packaging container employing said film, and by the method for producing thermomechanically stable heat-sealable polymeric film coated by vapor deposition according to the invention, as defined in the appended claims.
    [0018] Thus, the present invention provides a thermomechanically stable heat-sealable polymeric film suitable for lamination of liquid carton packaging material and heat-sealable packaging, consisting of a core layer consisting of polyethylene and containing more than 40% by weight of a polyethylene selected from the group consisting of MDPE, HDPE, modified MDPE, modified HDPE, and mixtures of two or more of them, the film additionally having a heat sealing layer, which is contiguous to the core layer on a first side and consists of low density ethylene polymer, and having a thin barrier coating applied by vapor deposition on its second opposite side, the polymeric film having a total thickness of 12 to 20 μm, preferably from 14 to 18 μm.
    [0019] More preferably, the total thickness of the polymeric film is 15 to 17 μm
    [0020] With modified HDPE and modified MDPE is meant grades of polymer that have been modified in the polymerization process to include two components having different molecular weight characteristics, i.e. not a physical mixture, but a polymeric composition of two types of polymers. Such polymeric compositions have a so-called bi-modal or multi-modal molecular weight distribution, and may have advantages over physical compositions mixed in fusion of two different polymers. These multimodal compositions can be obtained by a polymerization process in multiple stages, in which the different stages are carried out under different reaction conditions, for example, using different catalyst systems, etc.
    [0021] According to an embodiment of the invention, the thin coating deposited by steam is a layer of metal or metal oxide, preferably of metal aluminum, i.e. a so-called metallized layer.
    [0022] A metallization layer, or ceramic layer, consisting of a thin coating containing a metal or metal oxide, is preferably applied by means of a vacuum deposition, but can less preferably also be applied by other methods generally known in the art having low productivity, such as electroplating or bombardment. The most preferred metal according to the present invention is aluminum, although any other metal capable of being deposited by vacuum, galvanizing or bombarding can be used according to the invention. Thus, less common metals such as Au, Ag, Cr, Zn, Ti or Cu can also be considered. Generally, thin coatings of pure metal or a mixture of metal and metal oxide provide barrier properties against water vapor and are used when the desired function is to prevent the migration of water vapor into the interior and through the multilayer or laminated film of packaging. At most preference, the metal in a metallization coating is aluminum (Al).
    [0023] Examples of ceramic coatings suitable as functional coatings according to the invention are SiOx coatings also containing carbon in their formula, and AIOx coatings and MgOx coatings can also be considered. This type of coating provides gas barrier properties to the coated multilayer film as well as some degree of water vapor barrier, and are transparent coatings, which may be preferred in some cases.
    [0024] A coating modality is an aluminum oxide coating having the formula AlOx where x ranges from 1.0 to 1.5, preferably AI2O3. Preferably, the thickness of that coating is 5 to 100 nm, preferably 5 to 30 nm.
    [0025] Preferably, these ceramic coatings are applied by means of physical vapor deposition (PVD) or reactive evaporation deposition or by the Plasma-enhanced Chemical Vapor Deposition (PECVD) method, in which metal or silicon vapor is deposited on the substrate in circumstances of oxidation, thus forming a layer of silicon oxide or amorphous metal oxide.
    [0026] Other coatings based on silicon oxide are SiOxCy and SiOxCyNz coatings. These coatings often provide good gas barrier properties, and in some cases also water vapor barrier properties.
    [0027] According to a particular embodiment of the film of the invention, the core layer additionally has a coating receiving layer, applied contiguously to and in contact with its second, opposite side, under the coating also consisting of polyethylene and being designed to receive the vapor deposition coating layer.
    [0028] This receptor layer considerably improves the adhesion and cohesion of a vapor deposited layer, especially metallized, applied on a polymeric substrate film. High adhesion of the metallized layer to the substrate film is necessary for the metallized layer to remain intact and unaffected during thermal extrusion lamination with other layers in a packaging laminate and to provide sufficient integrity properties to a finished packaging container made from packaging laminate, thus allowing good barrier properties in a final laminate that includes the metallized film.
    [0029] The thickness of the receiving layer is about 0.5 to about 5 μm, preferably from 1 to 4 μm.
    [0030] The vapor sealing layer consists mainly of low density ethylene polymers that are selected according to a modality in the group consisting of LDPE, LLDPE, metallocene catalyzed LLDPE (m-LLDPE), and mixtures of two or more of them. Low density polyethylenes by definition have a density in the range of 0.910 to 0.940 g / cm3, while linear low density polyethylenes are defined by a density range of 0.915-0.925 g / cm3. LDPE (low density nonlinear polyethylene) has a high degree of chain branching, while LLDPE's mainly have short chain branches.
    [0031] According to a particular embodiment, the innermost heat sealable layer includes a material in the group consisting of linear low density polyethylene (LLDPE), or metallocene polymerized LLDPE, in combination with preferably up to 30, preferably up to 20 % by weight of a conventional low density polyethylene (LDPE) based on the total weight of the heat sealable layer.
    [0032] According to one embodiment, the polymeric film is a blown film, i.e. a film manufactured by means of extrusion technology - blowing and subsequent coating by vapor deposition. Alternatively, a similar film can be produced using flat extrusion technology. The film blowing process provides better mechanical properties obtained in films due to the higher degree of orientation of the polymers than in films produced by an extrusion-casting process.
    [0033] According to an embodiment of the film of the invention, the coating receiving layer consists mostly of a polymer selected from a group consisting of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE's). The linear alignment of polymer molecules within the thin receptor layer of an LLDPE provides a clean surface with less presence of low molecular weight migrating compounds and thus better conditions for good adhesion and cohesion to and within the vapor deposition layer . In addition, LLDPE's have branches with smaller chains, because cross-links inside the polymeric layer are shorter and therefore the thermal resistance of the layer is higher than, for example, for LDPE in the lower density ranges. Thermal stability in the subsequent coating process is favorable to avoid, as much as possible, movements and tension forces on the film during the coating process. Certain types of LDPE, which have a density greater than 0.925 g / cm3, also have similar surface qualities and are equally suitable from the standpoint of adhesion and thermomechanical stability, so that good barrier properties in a final deposition-coated film steam or metallised are obtained and can be maintained after lamination with other layers in a finished laminate.
    [0034] According to another modality, the coating or metal receiving layer consists mostly of a polymer selected from the group consisting of ethylene polymers catalyzed by metallocene. Such metallocene-catalyzed ethylene polymers are selected from the group consisting of m-LLDPE, m-HDPE and m-MDPE. These metallocene-catalyzed polyethylenes also provide better thermal resistance and a clean surface, substantially without migration of low molecular weight compounds, thus providing better conditions for good adhesion and cohesion to and within the vapor deposition layer.
    [0035] A good balance of the processing properties and surface characteristics of the film is obtained if the metallocene-catalyzed polyethylene is mixed with a non-metallocene-catalyzed polyethylene within the same density category.
    [0036] Thus, according to a specific modality, the metal receiving layer providing good surface and adhesion properties includes a mixture of m-HDPE and HDPE. Suitably, this mixture includes from about 70 to about 80% by weight of m-HDPE and from about 20 to about 30% by weight of HDPE. According to an alternative of this embodiment, the metal receiving layer includes a mixture of about 30% by weight of m-LLDPE and about 70% by weight of LDPE.
    [0037] Thus, according to one embodiment, the metal receiving layer includes a polyethylene selected from the group consisting of LDPE, low density linear polyethylene (LLDPE, m-LLDPE) and mixtures of two or more of the same. With the choice of low density ethylene polymers also for the coating receiving layer, an easy and cost-efficient fabrication of the film is achieved, as well as good heat-sealing properties of the film, and at the same time it is possible to coat by deposition by steam a metal barrier coating and obtain good adhesion to the coating receiving substrate and good adhesion within the deposited metallized layer, providing good oxygen and water vapor barrier properties in a final packaging laminate that includes the coated film.
    [0038] According to another modality, the metal receptor layer is made up mostly of a polymer selected from a group consisting of ethylene-propylene having co-polymers, co-polymerized with a third alpha-olefinic monomeric constituent , preferably butylene. This ethylene-propylene-terpolymer also provides better thermal resistance and a clean surface, thus providing better conditions for good adhesion and cohesion to and within the vapor deposition layer.
    [0039] The core layer itself may be a multilayer structure with layers of the same polyethylene or mixture of polyethylene or polyethylene or mixture of similar polyethylene, that is, up to five, normally three layers of the same basic high or medium polyethylene material density. At this point it should be understood that, for example, high or medium density polyethylene materials of all types, including metallocene-catalyzed high or medium density polyethylene (m-HDPE, m-MDPE), can be included as unique components, such as mixtures with each other, or as mixtures with lower density polyethylene in each layer. Medium density polyethylenes are defined as having a density of 0.926 to 0.940 g / cm3. High density polyethylene has a density greater than or equal to 0.941 g / cm3. The composition of each layer can be different or the same as the other layers. By gradually changing a certain property between layers, such as flexural stiffness or crystallinity, a specific property profile can be achieved through the cross section of the core layer.
    [0040] According to the modality in which the barrier coating layer is an aluminum metal layer, the metallized layer provides good barrier properties at an optical density (OD) of 1.8 to 3.0, preferably 2 , 0 to 2.7, more preferably from 2.2 to 2.6. At an optical density below 1.8, the barrier properties of the metallized film are too low. Above 3.0, on the other hand, the metallization layer becomes too brittle, and the thermostability during the metallization process will be too low due to the higher thermal load when the substrate film is metallized for a longer time. The coating quality and adhesion will then be clearly negatively affected. An optimum point was then found between these values, preferably between 2.0 and 2.7.
    [0041] Generally, the vapor deposition coating of a barrier layer on the polymeric film in the final stage is carried out by means of a continuous method of physical or chemical vapor deposition. Various coatings of ceramic and metallic composition can be applied by these types of methods. Generally, the thickness of these vapor deposited coatings can vary between 5 and 200 nm. Below 5 nm such barrier properties may be too low to be useful and above 200 nm, the coating is less flexible and thus more subject to cracking when applied to a flexible substrate.
    [0042] In order to provide sufficient integrity of a packaging container produced from a specially metallized film coated by vapor deposition, according to the invention, the vapor deposited coated layer has an adhesion of at least 200, preferably at least minus 300 N / m (according to the sealing and peeling method proposed by the AIMCAL association, for adhesion of metallized layers).
    [0043] Sufficient adhesion is achieved partially through a surface treatment process, to activate the surface before coating by vapor deposition, especially metallization. Possible surface activation treatments are, for example, corona and plasma treatments. Plasma surface treatment is preferable since it is possible to perform it together with the metallization process and because it provides excellent surface properties for subsequent vapor deposition coating. For some combinations of types of film-receiving layer polymers and vapor deposition coatings, even flame surface treatment can work well.
    [0044] Preferably, the film according to the invention has an oxygen transmission rate of less than 100 cm3 / (m2 * 24h), 1 O2 atmosphere, 23 ° C, 50% RH.
    [0045] More preferably, a metallized film according to the invention has an oxygen transmission rate of less than 100 cm3 / (m2 * 24h), 1 atm O2, 23 ° C, 50% RH, and a permeation rate at water vapor less than 5, preferably less than 1 g / m2 at 38 (and 23) ° C, 24 hours, at a gradient of 0 to 90% RH.
    [0046] Oxygen transmission has been tested on an OTR Mocon 2/20 measuring device at 20% oxygen and corrected by a factor of 5 to 100% oxygen. To determine the water vapor barrier, a method based on ASTM F-1249-06, using a modulated infrared sensor for detection of relative humidity and measurement of water vapor transmission rate (WVTR), was used.
    [0047] It is also possible to include processing aids and handling additives in the polymers, such as anti-blocking agents and / or slip agents in the polymers included in the film of the invention
    [0048] The invention also relates to a packaging laminate containing a film according to the invention. The packaging laminate additionally comprises a bulky layer of paper or cardboard arranged to provide the greatest contribution to the flexural stiffness of the laminate. However, it is also conceivable that the bulky or central layer of the laminate is a bulky layer of polyolefin, made, for example, from polyethylene, polypropylene or ethylene copolymers, such as ethylene-propylene, ethylene-butene copolymers, ethylene-hexene, ethylene- (met) -alkyl acrylate or ethylene-vinyl acetate. The choice of material for such a polyolefin core layer can provide a transparent packaging laminate, to be used, for example, in a transparent food pouch. The polymeric layer of heat-sealable low-density ethylene in the prefabricated film is intended to form a free surface of the packaging laminate, intended for contact with food, which is facing the interior of a packaging container made with the laminate of packaging to be filled with a food product. However, it may be conceived, albeit with less preference for cost reasons, that one or more additional thermally sealable layers are applied to the film according to their incorporation into the packaging laminate, in which case the last additional thermally sealable layer on the part is provided inside the container is in direct contact with the food.
    [0049] In addition, the packaging laminate includes one or more heat-sealable polyolefin outer layers disposed on the opposite side of the bulky or central layer. Such heat-sealable outer layers of polyolefin will be directly in contact with the environment surrounding the packaging container.
    [0050] According to a preferred embodiment, the packaging laminate contains one or more additional oxygen barrier layers between the cardboard layer and the vapor deposited heat sealable barrier film of the invention. Examples of such low-cost, well-functioning oxygen barrier layers are barrier layers applied to the paper or cardboard layer by coating with a liquid film of a dispersion or polymer solution with gas barrier properties, or similar dispersions of inorganic laminar compounds such as talc or filling clay nanoparticles. Preferred oxygen barrier layers obtained in this way contain both an oxygen barrier polymer and that inorganic filler compound. Examples that work well for such oxygen barrier polymers suitable for liquid film coating are poly (vinyl alcohol) (PVOH), ethylene vinyl alcohol dispersible polymer (EVOH), starch and starch derivatives. Most preferred polymers are PVOH.
    [0051] The packaging container made with the packaging laminate according to the invention can have any known shape. Preferably, it is a brick or wedge shaped container that is durable in handling and distribution and resistant to moisture and gaseous oxygen during long-term storage, due to the high quality packaging laminate, which also provides high sealing quality and excellent gas barrier properties. An important additional advantage of packaging containers produced with the packaging laminate according to the invention is that they can be durable in microwave cooking or defrosting. Alternatively, a packaging container can be of the pillow-shaped fiber pouch type like the packaging container known by the brand name Tetra Fino (R).
    [0052] In accordance with another aspect of the invention, a method is provided for the manufacture of a thermomechanically stable, heat sealable, barrier-coated polymeric film of the invention. The method has the steps of: a) forming a polymeric film with a thickness of 12 to 20 μm, preferably from 14 to 18 μm, by means of an extrusion manufacturing method, the polymeric film containing a core layer consisting of polyethylene , and with more than 40% by weight of a polyethylene selected from the group consisting of MDPE, HDPE, modified MDPE, modified HDPE and mixtures of two or more of them, the polymeric film additionally containing a heat sealable layer, which is laminated in the core layer on a first side and consisting of a low density ethylene polymer, and subsequently b) vapor deposition of a barrier coating, preferably a metal coating, on one side of the film.
    [0053] According to an embodiment of the invention the method further comprises the step of: c) superficially treating the side of the polymeric film to be coated by vapor deposition, before step b) vapor deposition of the barrier coating .
    [0054] Preferably, the polymeric film is manufactured using the film blowing extrusion technique.
    [0055] According to an embodiment of the invention the coated layer by vapor deposition is a metallized layer. Preferably, the metallized layer is vapor deposited with an optical density (OD) of 1.8 to 3.0, preferably of 2.0 to 2.7, more preferably of 2.2 to 2.6.
    [0056] According to another embodiment of the invention a coating receiving layer is laminated on the side of the core layer which will be oriented to receive the coated layer by vapor deposition. DESCRIPTION OF THE DRAWINGS
    [0057] Other advantages and favorable features of the present invention will be apparent from the following detailed description, with reference to the attached figures, in which:
    [0058] Figs. 1 a and 1 b show section views of heat-sealable, thermomechanically stable polymeric films, coated with vapor deposition barrier, according to the present invention,
    [0059] Fig. 2a is a sectional view of a laminated packaging material in accordance with the present invention, including a vapor-sealable, heat-sealable polymer film in accordance with the invention, as described in accordance with Fig. 1,
    [0060] Fig. 2b shows how the packaging laminate exemplified in Fig. 2a can be manufactured according to the invention,
    [0061] Fig. 3 is a diagrammatic view of a blown co-extrusion plant of the polymeric film of the invention,
    [0062] Fig. 4 is a diagrammatic view of a plan for coating with metal or metal oxide of the polymeric film as shown in Figs. 1a and 1b.
    [0063] Fig. 5a shows an example of a packaging container produced with the packaging laminate according to the invention,
    [0064] Fig. 5b shows a second example of a packaging container produced with the packaging laminate according to the invention, and
    [0065] Fig. 6 shows the principle of how such packaging containers are manufactured with the packaging laminate in a continuous process of forming, filling and sealing. DESCRIPTION OF PREFERRED EMBODIMENTS
    [0066] Fig. 1a shows a thermomechanically stable, heat sealable substrate polymer film 10a coated with vapor deposition, composed of a core layer 11 consisting of polyethylene and containing more than 40% by weight of a polyethylene selected from polyethylene medium and high density, and a heat seal layer 12, which is adjacent, ie contiguous, to the core layer on one side and consisting of LLDPE having a density of 0.915 to 0.925. On the other side of the core layer, a thin vapor deposition layer is coated having the function of barrier layer 13, especially a metallized aluminum layer. The total thickness of the substrate polymeric film 10a is about 17 μm and the thickness of the heat seal layer is about 7-8 μm. The film has shrinkage below 3%, preferably lower than 2% (measured at 80 ° C).
    [0067] Fig. 1 b shows a thermomechanically stable, heat sealable film coated with vapor deposition barrier 10b, which is obtained by vapor deposition of an aluminum metal coating 13 on a receiving layer 14, additionally applied over the other side of the core layer 11 in the polymeric film of Fig. 1a. The aluminum metallization layer 13 has an optical density of about 2.0 to about 2.7. The total thickness of the substrate polymeric film 10b is about 17 μm and the thickness of the receiving layer is about 4 μm. The thickness of the core layer is about 7 μm (it can be 6 to 10 μm), while the heat sealing layer is about 6 μm thick (it can be 3 to 7 μm thick). The film has shrinkage below 3%, preferably below 2% (measured at 80 ° C).
    [0068] Fig. 2a shows a packaging laminate 20a, containing a film deposited by vapor deposition 10b as described in Fig. 1b, laminated by means of at least one intermediate layer of connection 24 to a bulky layer of paper or cardboard. 21 a. The intermediate bonding layer is preferably a lamination layer with extrusion of thermoplastic polymer and may include one or more additional layers, for example, oxygen barrier layers of thermoplastic polymer. The layers can then be co-extruded together in the joint laminating operation of the film 10b with the cardboard layer 21a. Alternatively, a barrier layer can be coated or pre-laminated on cardboard 21a, prior to laminating the heat sealable barrier film 10b.
    [0069] The thickest layer of the laminate is a bulky layer of paper or cardboard 21a. Any paper or cardboard suitable for liquid carton packaging can be used for the bulky layer 21a. It should be noted that the laminate layers in Fig. 2a do not reflect the fact that the thickness of the vapor deposition film 10b is significantly thinner or at least as thin as that of the bulky paper layer 21a.
    [0070] On the outer part of the paper or cardboard layer, which will constitute the outer wall of a packaging container produced with the packaging laminate, an outer layer 26 of a heat-sealable polyolefin is applied, such as preferably a low polyethylene. density (LDPE) or a linear low density polyethylene (LLDPE), which may also include so-called metallocene catalyzed LLDPE's (m-LLDPE), ie LLDPE polymers catalyzed by means of a single site catalyst, or mixtures of two or more of such heat sealable polyolefins.
    [0071] It should be understood that the packaging laminate shown in Fig. 2a should be seen as a mere example, from which a person skilled in the art will have no trouble deducting various other embodiments.
    The packaging laminate 20a according to the invention can be produced according to any suitable prior art principle known to a skilled person. Preferably, however, with reference to the laminator shown in Fig. 2a, the connecting layer 24 can be extruded in a space between laminator rolls, between the bulky layer of paper or cardboard 21a and the prefabricated metallized film 10b. The metallized layer is preferably subjected to flame, plasma or corona treatment before being laminated to the bulky layer of paper or cardboard. Finally, the outermost layer 26 of heat sealable polyolefin is extruded onto the bulky layer of paper or cardboard 21a.
    [0073] In Fig. 2b, the lamination process 20b is shown, in which the paper or cardboard layer 21 b, which can, according to a preferred embodiment of the invention, be coated with an oxygen barrier from a liquid dispersion or solution of a polymer having oxygen barrier properties and subsequently dried, is laminated with a polymeric substrate film 23 subjected to vapor deposition, having a thin coating deposited by vapor 23a on the side that faces the paper layer, extruding an intermediate LDPE bonding layer 24 from an extruder 24a and pressing the assembly in a roller spacing 25. In the case of a metallized vapor deposition coating, the contact surface of the substrate film, or the receiving layer, is pretreated by a surface treatment (not shown) before pressing the set of layers into the space between rollers. Subsequently, the paper and film laminate passes through a second extruder 27 and space between laminating rolls 28, in which an outermost layer of heat-sealable LDPE 26 is coated on the outer side of the paper layer. Finally, the finished packaging laminate 29 is wound on a storage coil, not shown.
    [0074] Fig. 3 is a diagrammatic view of a plant for blowing (co-) extrusion of an intermediate film, i.e. the polymeric substrate film before being coated by vapor deposition of a metal or an inorganic metal compound. The one or more layers of the substrate polymeric film are (co-) extruded from one or more extruders 30 and blown 32, to form a film 34 of relatively high thickness. Other methods of forming the non-oriented polymeric film, such as flat co-extrusion, can also be contemplated as possible by a person skilled in the art.
    [0075] Fig. 4 is a diagrammatic view of an example of a vapor deposition coating plant for the intermediate film produced in Fig. 3. The film 34a of Fig. 3 is subjected on the receiving side of the coating to deposition by continuous evaporation 40, of a metallized layer of aluminum, possibly in admixture with aluminum oxide, the coating being made with a thickness of 5-100 nm, preferably 5-50 nm, so that the coated film 10b of the invention is formed. The aluminum vapor comes from a source of solid evaporation 41.
    [0076] Fig. 5a shows an example of a packaging container 50a produced with the packaging laminate 20a according to the invention. The packaging container is particularly suitable for drinks, sauces, soups or the like.
    [0077] Typically, such a container has a volume of about 100 to 1000 ml. It can be of any configuration, but is preferably brick-shaped having transverse and longitudinal seals 51a and 52a, respectively, and optionally an opening device 53. In another embodiment, not shown, the packaging container can be shaped like a wedge. To obtain such a "wedge shape", only the bottom portion of the package is folded so that the heat-transverse seal of the bottom is hidden under the triangular flaps of the corners, which are folded and sealed against the bottom of the package. The cross-sectional seal of the top section is left unfolded. In this way the half-folded packaging container is still easy to handle and dimensionally stable when placed on the shelf of a food store or on a table or similar.
    [0078] Fig. 5b shows a preferred alternative example of a packaging container 50b produced with a packaging laminate 20a according to the invention. As the packaging laminate 20a according to this embodiment is thinner because it has a thinner paper core layer, it is not dimensionally stable enough to form a parallelepiped or wedge-shaped packaging container, and is not shaped with folds after transverse sealing 52b. It will remain as a container similar to a bag in the form of a pillow and thus be distributed and sold.
    [0079] Fig. 6 shows the principle described in the introduction to the present application, ie a packaging material web is formed into a tube 61 by the longitudinal edges 62, 62 'of the web being joined together in an overlapping joint. 63. The tube is filled in 64 with the desired liquid food product and is divided into individual packages by repeated transverse seals 65 of the tube with a predetermined distance from each other below the level of the content placed in the tube. The packages 66 are separated by incisions in the transverse seals and receive the desired geometric configuration by forming folds along lines of crease prepared in the material.
    [0080] In conclusion it should be noted that the present invention, which has been described above with particular reference to the drawings presented, is not restricted to these embodiments, described and shown exclusively as examples, and that modifications and changes obvious to a knowledgeable person of art are possible without abandoning the design of the invention as disclosed in the appended claims.
    权利要求:
    Claims (17)
    [0001]
    1. Polymeric film, thermomechanically stable, heat sealable (10a; 10b), suitable for liquid lamination of packaging box and heat sealable packaging, characterized by the fact that it comprises a core layer (11) consisting of polyethylene and comprising more than 40 % by weight of a polyethylene selected from the group consisting of MDPE, HDPE, modified MDPE, modified HDPE, and mixtures of two or more of them, modified meaning grades of polymer that have been modified in the polymerization process to include two components having different characteristics molecular weight, that is, not a physical mixture, but a polymerized composition of two types of polymers, having a so-called bi-modal or multimodal molecular weight distribution, which is attainable by a polymerization process in several stages, in which the different steps are carried out under different reaction conditions, the film additionally having a heat sealing layer (12), comprising mainly comprising low density ethylene polymers selected from the group consisting of LDPE, LLDPE, metallocene-catalyzed LLDPE (m-LLDPE) and mixtures of two or more of them, the heat-sealing layer (12) being contiguous to the core layer on a first side, the core layer (11) additionally having a coating receiving layer (14), applied in contiguous contact with its opposite, opposite side, under a vapor deposition barrier coating (13) from 5 to 200 nm thick, the coating receptor layer (14) comprising mostly a metallocene-catalyzed ethylene polymer selected from the group consisting of m-LLDPE, m-HDPE and m-MDPE, and the polymer film having a total thickness of 12 to 20 μm.
    [0002]
    2. Thermomechanically stable, heat sealable polymeric film (10a; 10b) according to claim 1, characterized by the fact that the thin vapor deposition coating (13) is a layer of metal or metal oxide, preferably metal aluminum.
    [0003]
    3. Polymeric film, thermomechanically stable, heat sealable (10a; 10b), according to claim 1 or 2, characterized by the fact that the film is a blown film, ie a film manufactured by means of film blowing technology and subsequent vapor deposition coating.
    [0004]
    4. Thermomechanically stable, heat sealable polymeric film (10a; 10b) according to any of the preceding claims, characterized by the fact that the metallocene-catalyzed polyethylene of the coating receptor layer (14) is mixed with a non-catalyzed polyethylene by metallocene with the same density category.
    [0005]
    5. Thermomechanically stable, heat sealable polymeric film (10a; 10b) according to claim 4, characterized by the fact that the coating receptor layer (14) contains a mixture of m-HDPE and HDPE.
    [0006]
    6. Thermomechanically stable, heat sealable polymeric film (10a; 10b) according to any one of claims 2 to 5, characterized by the fact that the metallized layer (13) has an optical density (OD) of 1.8 to 3.0, preferably from 2.0 to 2.7, more preferably from 2.2 to 2.6.
    [0007]
    7. Thermomechanically stable, heat sealable polymeric film (10a; 10b) according to any one of claims 2 to 6, characterized by the fact that the metallized layer (13) has an adhesion of at least 200 N / m, preferably at least 300 N / m.
    [0008]
    8. Polymeric film, thermomechanically stable, heat sealable (10a; 10b), according to any of the preceding claims, characterized by the fact that the film has an oxygen transmission rate lower than 100 cm3 / (m2 * 24h) , 1 atm O2, 23 ° C, 50% relative humidity (RH).
    [0009]
    9. Polymeric film, thermomechanically stable, heat sealable (10a; 10b), according to any of the preceding claims, characterized by the fact that the film has a water vapor permeation rate of less than 5, preferably less than 1 g / m2 at 38 and 23 ° C, 24 hours, in a gradient of 0 to 90% RH.
    [0010]
    10. Packaging laminate (20a), characterized in that it comprises a film (10a; 10b), as defined in any of claims 1 to 9, also comprising a core layer (21a) of paper or cardboard.
    [0011]
    Packaging laminate according to claim 10, characterized in that said heat-sealable polymeric film (10a; 10b) forms a surface of the packaging laminate (20a) intended to form the inner surface of a packaging made with said packaging laminate.
    [0012]
    Packaging laminate according to claims 10 to 11, characterized in that an additional oxygen barrier layer is disposed between the cardboard (21a) and the heat-sealable polymeric film (10a; 10b).
    [0013]
    13. Packaging container for liquids (50a; 50b), characterized in that it is formed from a packaging laminate (20a) as defined in any of claims 10 to 12.
    [0014]
    14. Method for the manufacture of polymeric film with barrier coating, thermomechanically stable, heat sealable, as defined in any of claims 1 to 9, characterized by the fact that it comprises the steps of: a) forming a polymeric film (34) with thickness from 12 to 20 μm, preferably from 14 to 18 μm, by means of an extrusion manufacturing method (30, 32), the polymeric film comprising a core layer (11) consisting of polyethylene, and comprising more than 40% by weight of a polyethylene selected from the group consisting of MDPE, HDPE, modified MDPE, modified HDPE and mixtures of two or more of them, modified meaning grades of polymer that have been modified in the polymerization process to include two components having different weight characteristics molecular, that is, not a physical mixture, but a polymerized composition of two types of polymers, having a so-called bi-modal or multimodal molecular weight distribution, which is achieved removable by a polymerization process in several stages, in which the different stages are carried out under different reaction conditions, the polymeric film additionally comprising a heat sealing layer (12), comprising mainly low density ethylene polymers selected from the group consisting of of LDPE, LLDPE, metallocene-catalyzed LLDPE (m-LLDPE) and mixtures of two or more of them, which is laminated with the core layer on the first side, and the core layer (11) additionally having a receptor layer of coating (14), being applied in contiguous contact with its second, opposite side, and comprising mostly a metallocene-catalyzed ethylene polymer selected from the group consisting of m-LLDPE, m-HDPE and m-MDPE, and subsequently b) depositing by steam (40) one barrier coating on the other, second side of the film, on the coating receiving layer (14).
    [0015]
    15. Method for the manufacture of a polymeric film with a thermomechanically stable, heat-sealable barrier coating, according to claim 14, characterized by the fact that the method additionally has the step: c) treating the surface of the second side of the film polymeric to be coated by vapor deposition, before step b) vapor deposition of the barrier coating.
    [0016]
    16. Method according to claim 14 or 15, characterized in that the vapor-deposited coated layer is a metallized layer.
    [0017]
    17. Method according to claim 16, characterized in that the metallized layer is deposited by steam with an optical density (OD) of 1.8 to 3.0, preferably of 2.0 to 2.7, more preferably from 2.2 to 2.6.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012005433B1|2021-03-02|polymeric film, thermomechanically stable, heat sealable, packaging laminate, packaging container for liquids, and method for making the polymeric film
    CN107757031B|2021-06-01|Multilayer barrier film, packaging laminate comprising the film, packaging container made from the packaging laminate and method for producing the film
    JP2011525547A|2011-09-22|Uniaxially oriented polymer substrate film
    TWI381946B|2013-01-11|A polymer film, a packaging laminate comprising the polymer film, a packaging container formed from the packaging laminate and a process for the production of the polymer film
    US11046060B2|2021-06-29|Laminated packaging material comprising a barrier film and packaging containers manufactured therefrom
    JP3969954B2|2007-09-05|LAMINATED PACKAGING MATERIAL WITH GAS BARRIER LAYER BASED ON STARCH, PROCESS FOR PRODUCING THE SAME, AND PACKAGING CONTAINER
    JP6737772B2|2020-08-12|Packaging laminate, method for producing the same, and packaging container produced from the packaging laminate
    US10857769B2|2020-12-08|Laminated packaging material comprising a barrier film and packaging containers manufactured therefrom
    US20200190663A1|2020-06-18|Barrier film
    ES2890099T3|2022-01-17|Laminated packaging material comprising a barrier film and packaging containers made therefrom
    同族专利:
    公开号 | 公开日
    CN102481763B|2015-10-14|
    BR112012005433A2|2020-10-13|
    MX2012002592A|2012-04-19|
    CN102481763A|2012-05-30|
    MX345310B|2017-01-25|
    WO2011029597A1|2011-03-17|
    US20120171453A1|2012-07-05|
    EP2475520A1|2012-07-18|
    EP2475520B1|2018-10-24|
    JP5615366B2|2014-10-29|
    AR078284A1|2011-10-26|
    JP2013504450A|2013-02-07|
    RU2535712C2|2014-12-20|
    RU2012114149A|2013-10-20|
    TW201116403A|2011-05-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    BR9205821A|1991-03-29|1994-08-23|Bpi Environmental Inc|High density, high molecular weight polyethylene polymer, production process, thin film, transparent bag and process to improve the transparency properties of plastic films|
    CA2063473C|1991-07-01|1998-09-22|T. Hwee Ng|Process for preparing copolymers|
    US5194318A|1991-10-25|1993-03-16|Mobil Oil Corporation|Multilayer film with metallized surface|
    US5346763A|1993-04-21|1994-09-13|Mobil Oil Corporation|Multilayer film structure|
    CH685755A5|1993-06-03|1995-09-29|Tetra Pak Suisse Sa|A process for preparing a laminate.|
    US5725962A|1993-12-01|1998-03-10|Mobil Oil Corporation|Oriented HDPE films with metallized skin layer|
    SE504524C2|1995-07-03|1997-02-24|Tetra Laval Holdings & Finance|Packaging laminates that can be heat treated in a humid atmosphere|
    US6013353A|1996-05-07|2000-01-11|Mobil Oil Corporation|Metallized multilayer packaging film|
    US5885721A|1996-10-03|1999-03-23|Mobil Oil Corporation|Multilaminar high density polyethylene film with high biaxial orientation|
    US20030207054A1|1998-05-29|2003-11-06|Tetra Laval Holdings & Finance S.A.|Packaging laminates based on cardboard and paper|
    SE9804090D0|1998-11-26|1998-11-26|Tetra Laval Holdings & Finance|Multilayer structure for packaging and packaging containers manufactured therefrom, as well as method for manufacturing the multilayer structure|
    JP2000168770A|1998-12-11|2000-06-20|Nihon Tetra Pak Kk|Filling and packaging method for liquid food, and packaging material for paper container|
    US7371465B2|1999-03-30|2008-05-13|Exxonmobil Oil Corporation|Polyolefin film with embossed surface|
    US6723431B2|2000-01-24|2004-04-20|Exxonmobil Oil Corporation|Multilayer metallized polyolefin film|
    US6764752B2|2000-07-13|2004-07-20|Toray Plastics , Inc.|Biaxially oriented polypropylene metallized film for packaging|
    EP1260541A1|2001-05-21|2002-11-27|Atofina Research S.A.|Polyethylene films with improved processability and optical properties|
    US6709735B2|2001-11-14|2004-03-23|Mitsubishi Polyester Film, Llc|Oxygen barrier coating and coated film|
    JP2003170532A|2001-12-05|2003-06-17|Nihon Tetra Pak Kk|Paper packaging material for light-barrier liquid food|
    JP2004010067A|2002-06-04|2004-01-15|Nihon Tetra Pak Kk|Packaging material, packaging container, and method of manufacturing the packaging material|
    US7943700B2|2002-10-01|2011-05-17|Exxonmobil Chemical Patents Inc.|Enhanced ESCR of HDPE resins|
    WO2005077652A1|2004-02-16|2005-08-25|Hueck Folien Ges.M.B.H.|Plastic foil for packages with barrier layer, in particular for food packaging|
    SE0402197D0|2004-09-10|2004-09-10|Tetra Laval Holdings & Finance|A polymer film, a packaging laminate comprising the polymer film, a packaging container formed from the packaging laminate and a process for the production of the polymer film|
    US20070254147A1|2005-09-05|2007-11-01|Tetra Laval Holdings & Finance S.A.|Polymer Film, a Packaging Laminate Comprising the Polymer Film, a Packaging Container Formed from the Packaging Laminate and a Process for the Production of the Polymer Film|
    US20060135698A1|2004-12-21|2006-06-22|Fina Technology, Inc.|Blends of medium density polyethylene with other polyolefins|
    US20070082154A1|2005-10-12|2007-04-12|Benoit Ambroise|Multi-layer films, methods of manufacture and articles made therefrom|
    JP4793561B2|2006-01-26|2011-10-12|大日本印刷株式会社|Liquid paper container|
    JP2007302006A|2007-06-29|2007-11-22|Nihon Tetra Pak Kk|Manufacturing method of laminated packaging material|
    EP2216367A1|2009-02-09|2010-08-11|Total Petrochemicals Research Feluy|High impact resistance polyethylene|AT552304T|2008-01-02|2012-04-15|Flexopack Sa|PVDC FORMULATION AND HEAT SHRINKABLE FOIL|
    GB2475961B|2009-12-02|2015-07-08|Flexopack Sa|Thin film for waste packing cassettes|
    AR080691A1|2010-03-19|2012-05-02|Vinperfect Inc|OXYGEN REGULATION MECHANISM FOR A DRINK BOARD|
    EP2520518B1|2011-05-03|2020-09-23|Flexopack S.A.|Waste packaging device|
    EP2535279B1|2011-06-16|2016-11-16|Flexopack S.A.|Waste packaging system and film|
    DE102011108402A1|2011-07-26|2013-01-31|Sig Technology Ag|SURFACE CONNECTION WITH PLASTIC LAYERS OF DIFFERENT VICAT IMPROVEMENT TEMPERATURES|
    DE102011108401A1|2011-07-26|2013-01-31|Sig Technology Ag|Robust laminar composite with an intermediate layer with increased Vicat softening temperature|
    US9604430B2|2012-02-08|2017-03-28|Flexopack S.A.|Thin film for waste packing cassettes|
    CN102719200B|2012-06-21|2017-04-19|佛山新长盛塑料薄膜有限公司|High-stiffness high-strength heat-sealing embossed film and preparation method thereof|
    DE102013001263A1|2013-01-26|2014-07-31|Sig Technology Ag|Sheet-like composite with plastic layers of plastics of different damping properties with a layer containing LLDPE|
    DE202013004058U1|2013-04-30|2014-08-01|Dy-Pack Verpackungen Gustav Dyckerhoff Gmbh|paper bags|
    AU2014203227B2|2013-06-14|2018-01-04|Flexopack S.A.|Heat shrinkable film|
    WO2015028066A1|2013-08-29|2015-03-05|Tetra Laval Holdings & Finance S.A.|Packaging laminate and a packing container thereof|
    US10639871B2|2014-08-22|2020-05-05|Mitsui Chemicals, Inc.|Laminate film and packaging bag using same|
    EP3261838B1|2015-02-27|2019-04-03|Borealis AG|Laminated film structure based on polyethylene only|
    EP3397477A1|2015-12-28|2018-11-07|SIG Technology AG|Sheet-like composite, especially packaging laminate for dimensionally stable foodstuff containers, having a polymeric internal layer characterized by differential scanning calorimetry|
    JP6868207B2|2016-08-12|2021-05-12|大日本印刷株式会社|Packaging body consisting of film, laminated film and laminated film|
    US10543667B2|2016-12-30|2020-01-28|Toray Plastics , Inc.|Easy opening metalized hermetic films and methods to manufacture the same|
    CN109130413A|2018-08-02|2019-01-04|黄山永新股份有限公司|A kind of compound grade high glaze aluminium plating polyethylene blown film and its production method|
    法律状态:
    2020-10-06| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2020-10-13| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|
    2021-02-02| B09A| Decision: intention to grant|
    2021-03-02| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 10 (DEZ) ANOS CONTADOS A PARTIR DE 02/03/2021, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    SE0901176-8|2009-09-11|
    SE0901176|2009-09-11|
    PCT/EP2010/005539|WO2011029597A1|2009-09-11|2010-09-09|A barrier coated thermo-mechanically stable, heat sealable film, a packaging laminate comprising the film, a packaging container formed from the packaging laminate and a method for the production of the film|
    [返回顶部]