JP2007536140A - Laminate for plastic gas barrier packaging - Google Patents

Abstract

A gas barrier packaging laminate (10) having durability against the formation of stress cracks and having bending stiffness and excellent bonding between the layers of the laminate, and heat-sealable polyolefin (16, 17) An intermediate layer comprising two polymer-supporting layers (11, 12) each covered by a gas barrier layer (13, 14) of SiO _x , and at least a first (15a) and a second (15b) partial layer The first partial layer (15a) has higher rigidity than the second partial layer (15b), and the second partial layer (15b) is the first partial layer (15b). It has higher elastomer properties than the partial layer (15a). A rigid structural sandwich configuration is formed by two rigid support layers separated by an intermediate layer that is also shock absorbing to prevent stress cracking of the SIO _X layer. The present invention also relates to a packaging container produced from a packaging laminate and a method for producing the packaging laminate.

Description

The present invention has durability in the formation of stress cracks, and further has bending rigidity and excellent bondability between the layers of the laminate, and the outer layer of the heat-sealable olefin polymer, the first polymer-supporting layer the first gas barrier layer of SiO _X coated on, and the second second gas barrier layer of the coated SiO _X on the polymer carrier layer, and the first and second gas barrier coated polymer carrier layer The present invention relates to a laminate for gas barrier packaging comprising an intermediate polymer layer laminated therebetween. The present invention also relates to a method for producing a packaging laminate and a packaging container produced from the packaging laminate.

  In the modern market, it is a single-use, disposable plastic pouch that is preferably at least partially packaged to display content to the consumer, for example when displayed on a shelf in a grocery store There is an increasing demand for transparent beverages and liquid food packaging materials. Most commonly, such packaging is provided with a straw for direct drinking or a pull tab for opening and pouring the contents. Such packaging does not have the advantage of having the dimensions and gripping stability of the more common Tetra Brik® type cardboard packaging laminate beverage packaging. However, they are often used in many countries because the amount of packaging material used, as well as the volume of emptied packaging, is very small and can be made reusable with other similar flexible plastic items. And have the impression that it is of a better environmental profile. In addition, traditional Tetra Brik type packaging has an aluminum foil oxygen barrier, which is less desirable in some countries and also makes transparent packaging impossible.

A high-speed continuous packaging process, well known for Tetra Brik® type cardboard packaging, forms a web of packaging laminate continuously into a tube by simultaneous heat sealing and cutting operations to remove the contents. Filled, sealed and becomes a pillow-shaped packaging container.
Next, the pillow-shaped packaging container is usually folded into a parallelepiped packaging container. The main advantage of this continuous tube forming, filling, and sealed packaging process concept is that the web can be continuously sterilized just prior to tube formation, and therefore only with an aseptic packaging process, i.e. the contents of the liquid to be filled. The packaging material itself also has the potential for a process that reduces bacteria, so that the filled packaging container can be stored for long periods at ambient temperature without the risk of microbial growth in the filled product It is manufactured under a clean environment. Naturally, the gas barrier properties of filled and sealed packaging containers are also an important factor for long-term storage, which not only largely depends on the gas barrier properties of the packaging laminate itself, but also the final It also depends on the quality of the package seal and the arrangement of the openings. Another important advantage of the Tetra Brik® type packaging process is the possibility of continuous high-speed packaging, as mentioned above, which has a considerable impact on cost effectiveness. However, pouch-type beverage packaging available on the current market is generally manufactured by other non-sterile, more complex and costly processes of poor continuity.

It is also known in the prior art to deposit a gas barrier coating of SiO _x on a substrate by plasma enhanced chemical vapor deposition (PECVD). The advantages of the gas barrier layer of SiO _X compared to other gas barrier materials are firstly affected when it has a good environmental profile and secondly it is in contact with ambient moisture or liquids, for example. That is, the barrier properties remain intact and it is transparent and it is added to a very thin layer so that it is flexible when bent or folded and resists cracking.

From EP-A-385054 it is known to laminate two gas barrier layers of a silicon compound such as silicon dioxide facing each other by means of an intermediate adhesive layer. However, this document does not mention the resistance to the formation of stress cracks, the bondability of the layers of the laminate under mechanical stress, and the stiffness of the laminate, and provides shock absorption and further stiffening effects for the layers. The middle class is not described. Furthermore, the layer of silicon dioxide (SiO ₂ ) described is quite different from the layer of SiO _X PECVD coating contemplated by the present invention.

  Accordingly, there is a need for a thin, airtight, foil-free packaging laminate that has favorable properties for a sterile continuous high speed packaging process similar to the Tetra Brik Aseptic® packaging process. Important factors in such a process are stiffness, elasticity, and packaging laminate integrity. If the laminated web is too flexible and easy to move in high speed tube forming operations, the process cannot be performed safely and continuously. On the other hand, if the packaging laminate is too thin to obtain the required stiffness and durability, it may be difficult to manage the fold-forming operation and is not elastic during transfer and handling, In the absence of shock absorbing properties, there is a tendency to crack due to mechanical stress and lose its connectivity. Furthermore, it goes without saying that the cost efficiency of the material itself decreases with increasing thickness. In addition, packaging that is folded from a packaging laminate needs to be resistant to stress crack formation in order to withstand handling in transport and the like, which is a prerequisite that is difficult to combine with stiffness requirements. .

  Currently, commercially available pouch-type beverage packaging often has a laminated structure including a single gas barrier layer of, for example, ethylene vinyl alcohol polymer (EVOH), and does not have the rigidity requirements according to the present invention.

  Accordingly, it is an object of the present invention to provide a packaging laminate that alleviates the disadvantages and problems discussed above.

  The object of the present invention is to provide a continuous fluidized food with a continuous tube forming process that has gas barrier properties suitable for aseptic packaging and long-term storage, while at the same time providing sufficient bending stiffness, bondability and resistance to the formation of stress cracks in mechanical stress. It is intended to provide a packaging laminate that does not use metal foil and that is suitable for high speed packaging, and that is resistant to repeated stresses during transport and handling.

  Another object of the present invention is to provide a packaging laminate film having such required rigidity and durability, but thin enough to fold the package at at least one end of the package. Is to provide.

  Another object of the present invention is to provide a packaging laminate film that has the above properties but is transparent to make the packaging produced from the laminate an eye-catching appearance.

  The present invention is also directed to a packaging container produced from a packaging laminate of the present invention and filled with a beverage or liquid food, and a method for producing the laminated packaging material of the present invention.

  The objectives set forth above are achieved by an intermediate polymer layer laminated between the first and second gas barrier coated polymer support layers. The intermediate polymer layer includes at least a first partial layer and a second partial layer, the first partial layer has a higher rigidity than the second partial layer, and the second partial layer includes the first partial layer. It has higher elastomer properties than the partial layer. The overall packaging structure has excellent bending stiffness, its structural sandwich construction and elastic shock absorber, and stiffness to obtain a film that retains its bondability in aggressive transport conditions Combine the benefits of a promoter.

  The sandwich panel faces shown here by two polymer-carrying layer films work like I-shaped flanges by being separated from each other by an intermediate layer to withstand bending loads and increase the bending stiffness of the structure Let However, unlike type I steel structures, the lower density core further provides continuous support to the flange or face.

  The elastomeric properties of the second partial layer of the intermediate layer are the cyclic stresses or vibrations that are likely to occur during transport by absorbing mechanical stress through elastic and reversible deformation. It has been observed to increase the resistance of the packaging to crack formation during exposure.

  It has also been observed that the stiffness of the first partial layer of the intermediate layer generally makes an additional contribution to the stiffness of the packaging laminate in addition to the sandwich effect.

  Furthermore, as a comparison, if the intermediate layer is constituted by a single layer of a highly rigid polymer, such as the polymer of the first partial layer of the present invention, the risk of stress cracking due to mechanical stress is increased. It was observed.

  However, for comparison purposes, if a single polymer layer with high elastomeric properties constitutes the intermediate layer, the polymer with high elastomeric properties tends to melt excessively and flow out of the sealing area, i.e. the sealing window tends to narrow. It was observed that the stability of the laminate in the seal is likely to be compromised. Also, the required thickness of such an intermediate layer increases the cost of the laminate in an undesirable manner.

  Tests were conducted to address these issues, where the intermediate layer was composed of a blend of high stiffness polymer and high elastomeric polymer (ratio 25/75, 40/60 and 60/40). However, the results showed a similar failure frequency (50-90%) in the transport test simulation due to the formation of stress cracks as in the case of an intermediate layer constituted by a single layer of high stiffness polymer.

Accordingly, the solution to the problems and needs indicated above comprises an intermediate separating layer comprising two polymer-carrying layer films covered by a gas barrier layer of SiO _x comprising at least a first and a second partial layer. The first partial layer has a higher rigidity than the second partial layer, and the second partial layer has a higher rigidity than the second partial layer. The partial layer has higher elastomeric properties than the first partial layer, and the laminate further has a heat sealable layer outside of the thermoplastic polymer.

In the best mode embodiment, the intermediate layer consists of three partial layers, the third partial layer is identical to the first partial layer or the second partial layer, and the three partial layers are intermediate layers. In other words, two identical partial layers are in contact with the outside of one of the intermediate layers. Such a symmetrical arrangement reduces the risk of cracking, bending, in particular of SiO _X and makes an excellent seal.

  Since it has also been found that it is preferred to have more polymer with high elastomeric properties than high stiffness polymer in the intermediate layer, the best mode embodiment of the intermediate layer is that the third partial layer and the second partial layer It is preferred that they are the same, they are arranged on either side of the first partial layer, and all three layers are substantially the same thickness.

  In one embodiment, at least 50%, preferably at least 60% by weight of the intermediate layer is constituted by a layer with high elastomeric properties.

  However, the third partial layer is the same as the first partial layer, the second partial layer is located between the first partial layer and the third partial layer, and all three layers are substantially It is possible to envisage an embodiment that is preferably arranged to be of the same thickness.

  Preferably, each partial layer of the intermediate layer has a thickness of 5-30 μm, preferably 10-25 μm, most preferably 10-20 μm.

Preferably, the polymer support layer comprises a polyester, polyamide, or polypropylene material and thus has some inherent stiffness, although other relatively rigid polymers can be used in the support layer according to the present invention. More preferably, they are oriented films and thus have a higher degree of crystallinity than unoriented polymer films. The structural sandwich configuration of two relatively rigid support layers laminated on each side of such an intermediate polymer layer containing a thermoplastic polymer with high elastomeric properties is resistant to cracking during repeated mechanical stresses. Provided is a laminate having excellent resistance and surprisingly good bending stiffness with respect to its thickness. Furthermore, the arrangement of two PECVD-deposited SiO _X layers will be much better than a gas barrier increased by a factor of two compared to a laminate or film containing just one SiO _X layer. Proved. Thus, a configuration with a separate interlayer that also acts as a “buffer” against the ingress of gases, especially oxygen gas, provides surprisingly improved gas barrier properties, which proves the synergistic effect arising from this particular configuration To do. Thus, the laminate has excellent gas barrier properties, is economical in a high speed continuous packaging process, and is also easy to handle.

  The total thickness of the intermediate layer is 30 to 55%, preferably 35 to 50% of the total thickness of the packaging laminate. The intermediate layer consisting of at least the first and second partial layers is the thickest independent layer of the stack.

  Preferably, the thickness of the carrier layer comprises from about 5 to about 20% of the total packaging laminate, more preferably from about 5 to about 16%. The carrier layer contributes not only to its mere thickness but also to the overall bending stiffness of the packaging laminate by its interaction with a relatively thick intermediate layer.

  Preferably, the oriented polymer support layer is a pre-made film of polyester, polyamide (PA), or polypropylene (PP), such as a cast or co-extruded cast film, or more preferably, A uniaxial or biaxially oriented polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyamide (PA), polypropylene (PP) polymer film, or a multilayer film comprising a substrate surface layer of such a polymer, or at least A multilayer film comprising one such uniaxially or biaxially oriented layer.

  By using a pre-made oriented polymer film as the carrier layer, it is extruded or co-extruded laminated and has some inherent bending stiffness compared to other layers of the laminate with less thickness.

  The high stiffness polymer for the first partial layer is suitably selected from the group consisting of high density polyethylene (HDPE) and polypropylene (PP).

  Thermoplastic polymers with high elastomeric properties for the second partial layer consist of very low density polyethylene (VLDPE), very low density polyethylene (ULDPE), ethylene based copolymers or terpolymers, and polyolefin based elastomers or plastomers Appropriately selected from the group. More preferably, the polymer of the second partial layer is a polyethylene copolymer or VLDPE or ULDPE. An example of a shock absorbing polymer that performs particularly well is Dow's “Attane®” VLDPE. Other examples are “Exxco012” from EXXON and “Clearflex CLBO” from Polymeri.

  Preferably, therefore, the polymer of the second partial layer is a thermoplastic polymer having high elastomeric properties, and the polymer breaks and leaks along the seal region, eg, the transverse upper seal of the wedge-like pouch. Without giving impact energy and damping the packaging laminate with sufficient flexibility for the pouch or wall, the carrier layer polymer is oriented polypropylene, or preferably oriented. Polyester or polyamide.

According to a most preferred embodiment of the present invention, the gas barrier layer of SiO _X is in a position such as to face each other they are placed between the intermediate polymer layer in the laminate. In this way, an optimum gas barrier layer can be obtained and the SiO _x layer is protected in the best manner. However, embodiments in which one or both of the SiO _X layers face the outside in a laminate structure can also be envisaged.

The SiO _X layer is preferably deposited by PECVD technology. In this case, x = 1.7 to 2.0 with a thickness of about 50 to about 500 Angstroms (Å), preferably about 80 to about 300 (＝). There is another way of depositing an inorganic layer such as SiO _X on the polymer film, but it usually results in a thicker and less flexible SiO _X layer. This is due to the formation of cracks in the SiO _X layer, resulting in a lower quality laminate with respect to oxygen barrier overall. Accordingly, the gas barrier layer of SiO _X by the present invention is deposited by hexa dimethyl Shi Roxanne (hexadimethylsiloxane) (HDMSO) plasma enhanced chemical vapor deposition of SiO _X from the plasma of an organic silicon compound such as, PECVD, continuous process It is preferable.

  Preferably, the thickness of the carrier polymer layer is from about 7 to about 30 microns (μm), more preferably from about 8 to about 20, and most preferably from about 8 to about 15 μm, according to a preferred embodiment, The carrier polymer film has approximately the same or exactly the same thickness. The PECVD process is known to perform optimally for the above-mentioned thickness of the carrier layer, which is also preferred from an economic point of view. For certain desired properties, different thickness or flexural stiffness carrier layers can be used, but approximately the same to provide symmetric and reliable behavior in filling and packaging operations. Alternatively, it is best to use a support layer having exactly the same thickness, ie an outer layer in a sandwich configuration.

  Preferably, the overall thickness of the intermediate layer is from about 30 to about 90 μm, more preferably from about 35 to about 65 μm, and most preferably from about 40 to about 65 μm, preferably while the overall thickness of the packaging laminate is The thickness is from about 100 to about 180 μm, most preferably from about 100 to about 150 μm.

  If the second partial layer comprises a polymer such as VLDPE or ULDPE, for example, the thickness of the intermediate layer should be about 40 to about 65 μm for optimal shock absorption. For any other polymer in the second partial layer, use a thicker intermediate layer, such as up to 90 μm, especially if the total thickness of the packaging laminate is desired to be from about 150 to about 180 μm. It is feasible to do.

  Therefore, preferably, the thickness of the intermediate layer (15) is 35 to 65 μm, the thickness of the polymer support layer (11, 12) is 8 to 15 μm, and the heat-sealable olefin polymer (16, 17 ) Of the outer layer is 10 to 25 μm and 18 to 30 μm, respectively, and the total thickness of the packaging laminate is 100 to 150 μm.

  More preferably, the thickness of the intermediate layer (15) is 40 to 65 μm, the thickness of the polymer support layer (11, 12) is 12 to 15 μm, and the heat-sealable olefin polymer (16, 17) The outer layer has a thickness of 10 to 25 μm and 18 to 30 μm, respectively, and the total thickness of the packaging laminate is 100 to 150 μm.

  According to another preferred embodiment, the thickness of the intermediate layer (15) is 40 to 65 μm, the thickness of the polymer support layer (11, 12) is 8 to 12 μm and the heat-sealable olefin polymer The thicknesses of the outer layers (16, 17) are 10 to 25 μm and 18 to 30 μm, respectively, and the total thickness of the packaging laminate is 100 to 150 μm.

  Preferably, in order to obtain optimal bending stiffness and elasticity, the ratio between the thickness of the intermediate layer and the support layer is 2 to 8.5 when the total thickness is 100 to 150 μm, The ratio of the total thickness of the packaging laminate to the thickness of the intermediate layer and the thickness of the carrier layer when the total thickness is from 150 to 180 μm Is 4 to 10 and the ratio of the total thickness of the packaging laminate to the thickness of the intermediate layer is 1.7 to 3.

  A further important advantage is that such a packaging laminate can be made transparent in order to provide a packaging that is transparent at least in part so that the filled contents are visible.

  According to another aspect of the present invention, there is provided a packaging container, preferably a sterile packaging container, filled with a beverage or liquid food produced from the packaging laminate of the present invention.

  The packaging container according to the present invention is a pouch or a vertical pouch, or the like, with a high quality packaging laminate, resistant to handling and delivery, and resistant to moisture and oxygen gas during long term storage Thereby providing a quality seal and excellent gas barrier properties. A further important advantage of the packaging containers produced from the packaging laminate according to the present invention is that they withstand microwave cooking or thawing as well as retorting.

  According to another aspect of the present invention, there is provided a method for producing the laminated packaging material of the present invention.

  Further advantages and preferred features of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

Thus, FIG. 1a comprises first and second support layers 11, 12, which are preferably oriented polyester films such as, for example, polyethylene terephthalate (PET, OPET, or BOPET), or plasma enhanced chemical vapor deposition (PECVD). thin barrier layers 13, 14 of SiO _X was coated thereon by, comprises a film, preferably oriented polyamide (PA), shows a packaging laminate 10. The two SiO _X layers are preferably oriented towards the inside of the stack and are therefore facing each other. A first partial layer 15a of a high rigidity, preferably polyolefin-based thermoplastic polymer, such as, for example, high density polyethylene (HDPE) or polypropylene (PP), between two support layers covered by a gas barrier layer; and A second of thermoplastic polymers such as polyethylene-based thermoplastic polymers having high elastomeric properties such as, for example, very low density polyethylene (VLDPE), very low density polyethylene (ULDPE), polyethylene based copolymers or terpolymers, polyolefin based elastomers or plastomers The intermediate layer 15 including the partial layer 15b is laminated. The intermediate layer 15 is thicker than any of the surrounding layers of the packaging laminate and provides an element that itself separates between two carrier layer films of oriented polymer. The two partial layers 15a, 15b are of substantially the same thickness, and in another embodiment, the positions can be interchanged with each other.

  FIG. 1b shows a preferred packaging laminate 10 ′, in which the intermediate layer 15 is equivalent to the second partial layer 15b in addition to the first partial layer 15a and the second partial layer 15b. Of the third partial layer 15c. The first partial layer 15a is disposed between the second partial layer 15b and the third partial layer 15c.

  FIG. 1c shows another embodiment of the packaging laminate 10 ″, in which an intermediate layer 15 is added to the first partial layer 15a in addition to the first partial layer 15a and the second partial layer 15b. The second partial layer 15b is disposed between the first partial layer 15a and the third partial layer 15c.

In all embodiments shown in FIGS. 1a, 1b, 1c, a preferred, oriented polymer film may have a relatively higher degree of crystallinity than a polymer film in which it is oriented and therefore not oriented. Has a certain degree of inherent rigidity. A sandwich configuration of two relatively rigid support layers laminated on each side of a thicker intermediate polymer layer results in a layer with surprisingly good bending stiffness with respect to its thickness. Furthermore, the arrangement of two PECVD-deposited SiO _X layers will be much better than a gas barrier increased by a factor of two compared to a laminate or film containing just one SiO _X layer. Proved. Thus, the arrangement of the intermediate layer also acts as a “buffer” against the ingress of gases, in particular oxygen gas, resulting in surprisingly improved gas barrier properties, which show the synergistic effect resulting from this particular arrangement. As an example, two films of SiO _X coated BOPET are each laminated together by a thin polyolefin-based layer with an OTR value of about 4 cc / m ^{2 *} 24 h at 23 ° C. and 50% RH The OTR value of the overall structure is about ² cc / m ^{2 *} 24h and 50% RH at 23 ° C. When the same film is laminated with at least one intermediate polymer layer based on polyolefin having a thickness of about 55 g / m ² , the OTR value improves to about 0.2 cc / m ^{2 *} 24 h and 50% RH at 23 ° C. Similarly, two films of SiO _X- coated BOPET are laminated to each other by a thin polyolefin-based layer with an OTR value of approximately 1.6 cc / m ^{2 *} 24 h each at 23 ° C. and 50% RH. The OTR value of the overall structure is about 0.8 cc / m ^{2 *} 24h and 50% RH at 23 ° C. When the same film is laminated with at least one polyolefin-based intermediate polyolefin base layer having a thickness of about 55 g / m ² , the OTR value is about 0.16 cc / m ^{2 *} 24 h and 23% at 23 ° C. To improve. Thus, the improvement of the gas barrier due to the “buffer effect” is at least 4 to 5 times that of using a doubled gas barrier film laminated directly to each other.

  On the outside of the carrier layer 11 constituting the outer wall of the packaging container produced from the packaging laminate, at least a heat-sealable olefin polymer, preferably low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) is provided. A single layer 16 is deposited, which layer also includes metallocene-catalyzed LLDPE's (m-LLDPE) or what are referred to as LLDPE polymers catalyzed by a single site catalyst. Other examples of other polymers for the outer packaging wall layer can be medium high density polyethylene (MDPE) or polypropylene (PP).

  On the outside of the carrier layer 12 constituting the inner wall of the packaging container produced from the packaging laminate, a heat-sealable olefin polymer, preferably an LDPE layer, more preferably an LLDPE layer, most preferably an LDPE first layer. And at least one layer 17 of the second outermost partial layer 17b of LLDPE is deposited.

  The outer layers 16, 17 are each deposited in an amount of about 10 to about 30 μm to obtain optimum heat sealability properties for cost efficiency.

  In order to achieve good adhesion between the various layers of the packaging laminate, it is preferred to use adhesive polymer, tie layers, and primer binder layers known in the art. Such binder layers and primers are adapted to the particular choice of polymer in the various layers and can be selected from polyolefins such as LDPE and modified LDPE and modified polyolefins, preferably polyethylene-based polymers.

  Such examples of binder layers are, for example, ethylene (methacrylic) acrylic acid copolymer (E (M) AA), ethylene glycidyl (methacrylate) acrylate copolymer (EG (M) A), or MAH grafted (MAH- grafted) LDPE homo or copolymers or graft copolymers of polyethylene crafted with monomers containing carboxy or glycidyl functional groups such as acrylic or maleic anhydride (MAH) monomers of polyethylene (MAH-g-PE).

Preferably, U.S. Pat. No. 5,731,092, incorporated herein by reference, to obtain optimum adhesion at the binder layers 18, 19 between the SiO _X layers 13, 14 and the intermediate polyolefin layer 15. Polyethylene-based polymer grafts modified with unsaturated organooxysilane compounds as described are used. See in particular the 39th line of the first column to the 21st line of the third column and Examples 1 and 2.

  Most preferably, polyethylene-based polymer grafts modified with unsaturated organooxysilane compounds are preferably mixed with ungrafted polyethylene such as low density polyethylene (LDPE). Surprisingly, when the grafted polyolefin is mixed with an ungrafted polyolefin, it is possible to greatly increase the number of adhesion points between the grafted site of the binder and the silicon oxide. That is, it has been found that the number of adhesion points increases despite fewer grafted portions of the polymer in the conjugate.

  This most preferred embodiment is based on the insight that it is not only the number of grafted points that affects the degree of adhesion, but also its ability to come into physical contact with silicon oxide. It has been found that grafting polyolefins according to US Pat. No. 5,731,092 results in cross-linking of the polyolefin, thereby making the polyolefin less flexible than ungrafted polyolefin. By reducing the flexibility of the grafted polyolefin, the number of contact points between the grafted polyolefin tie layer and the silicon oxide is greater than for the same type of ungrafted polyolefin tie layer. Less. However, in a tie layer consisting only of ungrafted polyolefin, the adhesion at the individual adhesion points of the plurality of adhesion points is not as good as at the individual adhesion points of the tie layer consisting only of the grafted polyolefin.

  Preferred embodiments further relate to these conflicting aspects of grafted and ungrafted polyolefin binders by providing a binder that is a mixture of grafted and ungrafted polyolefins. Solve a problem. Here, the increased flexibility afforded by the presence of ungrafted polyolefin results in an increase in the number of points of adhesion, and the grafted polyolefin results in improved adhesion at these points, after all, Adhesive properties which are superior to those of non-grafted polyolefin binders and non-grafted polyolefin binders are obtained.

Whenever a binder layer is used between the interlayer and the SiO _X layer, the thickness referred to as the total thickness of the interlayer also includes the thickness of such a tie layer.

  Any of the polymers discussed above can be used in the optional binder layers 20, 21 between the outer heat-sealable polyolefin layers 16, 17 and the polymer support layers 11, 12.

  FIG. 2 shows a preferred example of a packaging container 20 produced from a packaging laminate 10, 10 ′ or 10 ″ according to the invention. This packaging container is a small beverage for direct use, such as by a drinking straw. In particular, such packaging has a volume of about 330 ml or less, preferably about 100 to about 250 ml, such as about 125 ml, 200 ml, or about 250 ml, which can be of any shape pouch. However, it is preferably formed as a wedge 21 so that it is easy to handle and dimensionally stable when placed on a grocery store shelf or table, etc. Such a “wedge shape” To obtain, the bottom transverse heat seal 24 is hidden under the triangular corner flap 23 which is folded and sealed against the bottom of the package. As such, the bottom 22 of the package are folded form. The packaging container 20 is preferably transparent.

  FIG. 3a shows a preferred embodiment 30a of a method for producing a packaging laminate 10 ', 10' 'according to the present invention.

The first web 331 of the polymer support layer 332 covered by the SiO _X gas barrier layer 333 and the second web 334 of the polymer support layer 335 covered by the SiO _X gas barrier layer 336 are fed toward the extrusion station 337. Two SiO _X layers 333 and 336 preferably face each other, extrude an intermediate three-part polymer layer 338 between them, and pass through the roller nip after the extrusion station 337, and the two webs 331, 334 and intermediate The layers 338 are stacked together by pressing together. The intermediate polymer layer 338 can also be coextruded with an adjacent layer of binder polymer 339 to improve bonding to the SiO _x layer on the two webs 331 and 334. The resulting laminated web 340 is sent to an extrusion station 341 where an outer layer of heat sealable polyolefin 342 is extruded onto the outside of the polymer support layer 335. The web 343 thus produced is further sent to an extrusion station 344 where heat sealable polyolefin 345 is extruded onto the outside of the polymer support layer 332. The resulting package laminate 346 is then rolled up and stored on a reel (not shown).

  FIG. 3b shows another preferred embodiment 30b of a method for producing a packaging laminate 10 ', 10 "according to the present invention.

The first web 331 of the polymer support layer 332 covered by the SiO _X gas barrier layer 333 and the second web 334 of the polymer support layer 335 covered by the SiO _X gas barrier layer 336 are fed toward the extrusion station 337. Two SiO _X layers 333 and 336 preferably face each other, extrude an intermediate three-part polymer layer 338 between them, and pass through the roller nip after the extrusion station 337, and the two webs 331, 334 and intermediate The layers 338 are stacked together by pressing together. The intermediate polymer layer 338 can also be coextruded with an adjacent layer of binder polymer 339 to improve bonding to the SiO _x layer on the two webs 331 and 334. The resulting laminated web 340 consists of at least one layer of polyolefin 342 'that can be heat sealed by feeding it to the hot roller nip 341' where it applies heat and pressure at the hot roller nip 341 '. A pre-manufactured film outer layer is laminated to the outside of the polymer carrier layer 335. The web 343 'thus produced is further fed to a hot roller nip 344' where the outer layer of heat-sealable polyolefin 345 'is polymer loaded by applying heat and pressure at the hot roller nip 344'. Laminated outside the layer 332.

  The resulting packaging laminate 346 'is then wound and stored on a reel (not shown).

  FIG. 3c shows a further preferred embodiment 30c of a method for producing a packaging laminate 10 ', 10 "according to the present invention.

The first web 331 of the polymer support layer 332 covered by the SiO _X gas barrier layer 333 and the second web 334 of the polymer support layer 335 covered by the SiO _X gas barrier layer 336 are fed toward the hot roller nip 337 ′. Two SiO _X layers 333 and 336, which are preferably pre-manufactured and extruded together, as a web of an intermediate three-part polymer layer 338 ', preferably facing each other, are nipped between the two webs 331, 334 Sent to 337 ′. The three webs are laminated together by applying heat and pressure as they pass through the hot roller nip 337 '. The intermediate polymer layer 338 ′ can be a prefabricated film having an outer layer of binder polymer 339 to improve bonding to the SiO _X layer on the webs 331, 334. The resulting laminated web 340 ′ is fed to a hot roller nip 341 ′ where an outer layer of a prefabricated film consisting of at least one layer of heat sealable polyolefin 342 ′ becomes a hot roller nip 341. Is laminated on the outside of the polymer support layer 335 by applying heat and pressure. The web 343 "produced in this way is further fed to a hot roller nip 344 ', where an outer layer of a prefabricated film consisting of at least one layer of heat sealable polyolefin 345' becomes a hot roller nip 344. It is laminated on the outside of the polymer support layer 332 by applying heat and pressure at '.

  The resulting packaging laminate 346 "is then wound and stored on a reel (not shown).

  In the method 30a described above, the extrusion stations 341 and 344 can be passed in reverse order according to another preferred embodiment.

  In each of the above methods 30b and 30c, the lamination of the outer heat-sealable polyolefin film is reversed, ie first the pre-made film 345 ′ is laminated to the outside of the polymer support layer 332 at the hot roller nip 344 ′. , So that the web 347 is generated. The web 347 is further fed to a hot roller nip 341 ′ where an outer heat-sealable prefabricated film 342 ′ is laminated on the outside of the polymer support layer 335 so that the packaging laminate A body 346 'or 346 "is generated.

  Other combinations of hot nip lamination and extrusion lamination are not represented by individual drawings, but are conceivable within the concepts of the present invention. For example, the method in which the middle three-part polymer layer 338 ′ is a pre-made film laminated in a hot nip as shown in FIG. The sealable layers 342 and 345 can be associated with one or both extrusion laminates.

According to other preferred embodiments of the methods 30a, 30b, 30c, the surface of the SiO _X gas barrier layers 333, 336 provides improved adhesion to the intermediate polymer layers 338, 338 ′ or binder layers 339, 339 ′. Therefore, it is processed by surface oxidation treatment such as corona treatment.

According to another embodiment of the method for producing the packaging laminate of the present invention, the various pre-fabricated webs 331, 334, 338 ′, 342 ′, and 345 ′ are formed by primer lamination, ie, a primer or anchor agent. Are laminated together by coating one side of the web, drying and then laminating by roller nip. The packaging laminate 10, 10 ', 10 "has a printed decorative layer to make the packaging container more eye-catching, inform the consumer and protect its contents against light. And the printed decoration can be applied on top of the SiO _X layer 333 or 336 and can be directed to the outside of the package formed from the packaging laminate, or it can be opposite the carrier layer 332. It can be applied on the side or on the outer layer of heat-sealable polyolefins 342, 345, 342 ′, 345 ′, in which case the printed outside is preferably covered by a thin, transparent protective polymer layer. Should be.

  FIG. 4 shows strain-stress graphs for four different polymers or polymer blends, thereby providing a basis for comparing the elastomeric properties of the polymer / polymer blend.

  Curve 1 represents 100% HDPE, curve 2 represents a blend of 60% VLDPE and 40% HDPE, curve 3 represents a blend of 75% VLDPE and 25% HDPE, and finally curve 4 represents 100% VLDPE. Represents. As is readily understood, the elastomeric properties increase with increasing VLDPE content, and pure VLDPE has the highest elastomeric properties.

ＨＤＰＥのみの中間層を有する包装の間で漏洩が頻繁に起こり、一方、実際に中間層としてＶＬＤＰＥのみを有する包装からは漏洩が全くなかった。しかし、中間層としてＶＬＤＰＥのみを有する包装は、望ましくない低い剛性を示した。本発明による、すべて同じ厚さの３つの部分層を有する積層体は、より優れた剛性値を有し、最も多くＶＬＤＰＥを含む１つ、すなわちＶＬＤＰＥ／ＨＤＰＥ／ＶＬＤＰＥ、及び同じ厚さのすべての３つの部分層は、最低の破損率でもあった。 A comparatively simulated (but more stringent than normal actual transport conditions) transport test shows that in all tests two identical outermost sealing layers, two SiO _X coating carrier layers of the same thickness and type, and Implemented on a package made from a laminated structure according to the present invention with an intermediate layer having the same overall thickness. All packaging was produced in the same style. The only difference between the packages tested was the internal composition of the middle layer of the laminate structure. Twenty packages of each type were subjected to simulated transport tests, ie, placed on a vibrating table for 30 minutes and subjected to repeated vibrations. See Table 1 for the results. Reference examples are a laminate having an intermediate layer of 45 g / m ^{2 with} only VLDPE and a laminate having an intermediate layer of 45 g / m ^{2 with} only HDPE.

Leakage frequently occurred between packages with HDPE-only intermediate layers, while there was no leakage from packages that actually had only VLDPE as the intermediate layer. However, packaging with only VLDPE as the intermediate layer exhibited an undesirably low stiffness. A laminate having three partial layers, all of the same thickness, according to the present invention has a superior stiffness value, one containing the most VLDPE, ie VLDPE / HDPE / VLDPE, and all of the same thickness The three partial layers also had the lowest failure rate.

  In conclusion, the present invention described above with specific reference to the accompanying drawings has been described exclusively by way of example and is not limited to these illustrated embodiments, but will be apparent to those skilled in the art. It should be observed that changes and modifications can be made without departing from the inventive concepts disclosed in the appended claims.

1 is a cross-sectional view of a first embodiment of a laminated packaging material according to the present invention. FIG. 3 is a cross-sectional view of a second best mode embodiment of the laminated packaging material according to the present invention. FIG. 6 is a cross-sectional view of a third embodiment of a laminated packaging material according to the present invention. It is a figure which shows the preferable example of the packaging container produced | generated from the laminated body for packaging by this invention. It is a figure which shows another preferable embodiment of the manufacturing method of the laminated body for packaging. It is a figure which shows another preferable embodiment of the manufacturing method of the laminated body for packaging. It is a figure which shows another preferable embodiment of the manufacturing method of the laminated body for packaging. Figure 5 is a strain-stress graph for four different polymers or polymer blends.

Claims (41)

A gas barrier packaging laminate (10) having durability against the formation of stress cracks, and further having bending stiffness and excellent bonding between the layers of the laminate,
An outer layer of heat-sealable olefin polymer (16, 17);
A first gas barrier layer (13) of SiO _X coated on the first polymer support layer (11);
A second gas barrier layer (14) of SiO _X coated on the second polymer support layer (12);
An intermediate polymer layer (15) laminated between the polymer support layers of the first and second gas barrier coatings;
The intermediate polymer layer includes at least a first partial layer (15a) and a second partial layer (15b), and the first partial layer (15a) is higher than the second partial layer (15b). The second partial layer (15b) has a higher elastomeric property than the first partial layer (15a), and the respective rigidity of the first and second polymer-carrying layers is The gas burr packaging described above, which interacts with the thickness of the intermediate polymer layer as a shock absorbing separation layer in a structural sandwich configuration to provide durability against stress cracking, bending stiffness, and excellent bondability between the layers. Laminated body.   2. The stress crack resistance, flexural rigidity, and bondability between the layers make the packaging laminate suitable for liquid food and beverage packaging through a high speed continuous process. Laminated body for gas barrier packaging.   The gas barrier packaging laminate according to claim 1, wherein the thickness of the intermediate layer (15) is 30 to 55%, preferably 35 to 50% of the total thickness of the packaging laminate (10). .   Gas barrier packaging according to any one of claims 1 to 3, wherein each of the partial layers of the intermediate layer (15) has a thickness of 5 to 30 µm, preferably 10 to 25 µm, most preferably 10 to 20 µm. Laminated body.   The laminate for gas barrier packaging according to any one of claims 1 to 4, wherein the intermediate layer (15) includes a third partial layer (15c, 15d).   The third partial layer (15d) is the same as the first partial layer (15a), and the second partial layer (15b) is between the first partial layer and the third partial layer. The laminate for gas barrier packaging according to claim 5, which is arranged so as to be in the position.   The third partial layer (15c) is the same as the second partial layer (15b), and the first partial layer (15a) is between the second partial layer and the third partial layer. The laminate for gas barrier packaging according to claim 5, which is arranged so as to be in the position.   The gas barrier according to any one of claims 5 to 7, wherein the first, second and third partial layers (15a, 15b, 15c, 15d) are all of substantially the same thickness. Laminate for packaging.   The laminate for gas barrier packaging according to any one of claims 1 to 8, wherein at least 50%, preferably at least 60% by weight of the intermediate layer is constituted by the layer having high elastomeric properties.   The thermoplastic polymer having high elastomeric properties for the second partial layer (15b) is selected from the group consisting of ultra-low density polyethylene, very low density polyethylene, polyethylene copolymers, polyethylene terpolymers, and polyolefin-based elastomers and plastomers The laminated body for gas barrier packaging as described in any one of Claims 1-9.   The gas barrier according to any one of the preceding claims, wherein the highly rigid polymer for the first partial layer (15a) is selected from the group consisting of high density polyethylene (HDPE) and polypropylene (PP). Laminate for packaging.   The thickness of the first polymer support layer (11) and / or the thickness of the second polymer support layer (12) is 5 to 20% of the total thickness of the packaging laminate (10). The laminate for gas barrier packaging according to claim 1, wherein   The thickness of the first polymer support layer (11) and / or the thickness of the second polymer support layer (12) is from 5 of the total thickness of the packaging laminate (10). The laminate for gas barrier packaging according to claim 12, which is 15%.   The first polymer-supporting layer (11) and / or the second polymer-supporting layer (12) comprises a polyester, polyamide or polypropylene film, or a multilayer film comprising a substrate surface layer of one of the polymers The laminate for gas barrier packaging according to claim 1, wherein   The first polymer support layer (11) and / or the second polymer support layer (12) is formed of uniaxially or biaxially oriented polyethylene terephthalate (PET), uniaxially or biaxially oriented polyethylene naphthalate (PEN). ), Uniaxially or biaxially oriented polyamide (PA), and uniaxially or biaxially oriented polypropylene, or a polymer selected from the group consisting of multilayer films comprising at least one oriented layer of said polymers The laminate for gas barrier packaging according to claim 1, which is a film.   The polymer having high elastomeric properties for the second partial layer comprises ultra-low density polyethylene, the highly rigid polymer for the first partial layer comprises high density polyethylene, and the first polymer-supporting layer (11 The laminate for gas barrier packaging according to claim 1, comprising an oriented polyester or polyamide, and a polymer of said second polymer-supporting layer (12). The first gas barrier layer of SiO _X (13) and the second gas barrier layer of SiO _X (14) has become a facing position to each other as viewed from each of the supporting layer of them in the layer, claim The laminate for gas barrier packaging according to 1. The first gas barrier layer of SiO _X (13) and the second gas barrier layer of SiO _X is (14), 500 Å 50 is preferably deposited by PECVD technique at a thickness of 300Å from 80, x is 1. The laminate for gas barrier packaging according to claim 1, which is 7 to 2.0.   The thickness of the first polymer-carrying layer (11) and / or the thickness of the second polymer-carrying layer (12) is 7 to 30 μm, preferably 8 to 20 μm, most preferably 8 to 15 μm. The laminate for gas barrier packaging according to claim 1.   The laminate for gas barrier packaging according to claim 1, wherein the first polymer support layer (11) and the second polymer support layer (12) have the same thickness.   The gas barrier packaging laminate according to claim 1, wherein the thickness of the intermediate layer (15) is 30 to 90 µm, preferably 35 to 65 µm, most preferably 40 to 65 µm.   The laminate for gas barrier packaging according to claim 1, wherein the total thickness of the packaging laminate is 100 to 180 µm, preferably 100 to 150 µm.   The thickness of the intermediate layer (15) is 35 to 65 μm, the thickness of the first polymer support layer (11) and / or the thickness of the second polymer support layer (12) is 8 to 15 μm, heat sealing The thickness of the outer layer of possible olefin polymers (16, 17) is 10 to 25 μm and 18 to 30 μm, respectively, and the total thickness of the packaging laminate is 100 to 150 μm. Laminate for gas barrier packaging.   The intermediate layer (15) has a thickness of 40 to 65 μm, the first polymer support layer (11) and / or the second polymer support layer (12) has a thickness of 12 to 15 μm. The laminate for gas barrier packaging according to claim 23.   The intermediate layer (15) has a thickness of 40 to 65 μm, the first polymer support layer (11) and / or the second polymer support layer (12) has a thickness of 8 to 12 μm. The laminate for gas barrier packaging according to claim 23. The laminate for gas barrier packaging according to claim 1, wherein the intermediate polymer layer (15) is laminated to the adjacent SiO _X layer (13, 14) by a binder layer (18, 19).   27. The gas barrier packaging laminate of claim 26, wherein the binder layer (18, 19) comprises a blend of an organooxysilane comprising ungrafted polyethylene and a graft copolymer of polyethylene.   The laminate for gas barrier packaging according to claim 1, wherein the laminate is transparent.   A packaging container produced from the packaging laminate according to claim 1. A heat sealable olefin polymer outer layer (16, 17), a first gas barrier layer (13) of SiO _X coated on the first polymer support layer (11), and a second polymer support layer ( 12) comprising a second gas barrier layer (14) of SiO _X coated on top of the polymer layer (15) comprising at least a first (15a) and a second (15b) partial layer, The first partial layer has higher rigidity than the second partial layer, the second partial layer has higher elastomeric properties than the first partial layer, and the intermediate layer (15) is A method for producing a laminate for packaging, laminated between a first and second gas barrier coated polymer carrier layer, comprising:
Sending a first web (331) and a second web (334) towards each other and towards a first extrusion station (337), wherein the first web (331) is a first A second polymer comprising a first polymer support layer (332) covered by a SiO _X gas barrier layer (333), wherein the second web (334) is covered by a second SiO _X gas barrier layer (336) Including a support layer (335);
By co-extruding the partial layers (15a, 15b, 15c, 15d) of the intermediate polymer layer (338), the first web (331) and the second web (334) can optionally be Laminating together with a binder layer (339) on each side of the intermediate polymer layer (338) between the first web and the second web, the first web and the second web together Pressing at the first extrusion station (337);
Extruding the first outer layer (342) on the outside of the first or second polymer support layer (332 or 335) in a second extrusion station (341), wherein the first outer layer (342) 342) comprising a heat-sealable polyolefin;
Extruding a second opposite outer layer (345) on the other outer side of the second or first polymer support layer (335 or 332) at a third extrusion station (344), comprising: The second opposite outer layer (345) comprising a heat-sealable polyolefin. It said first web (331) and said second web (334) comprises a gas barrier layer of SiO _X (333,336) is sent towards each other so as to face each other, The method of claim 30. The gas barrier layer (333) and the second SiO _X gas barrier layer of the first SiO _X is (336), are processed by a surface activation treatment before being laminated, the method according to claim 30.   The method according to claim 32, wherein the surface activation treatment is a corona treatment. A heat sealable olefin polymer outer layer (16, 17), a first gas barrier layer (13) of SiO _X coated on the first polymer support layer (11), and a second polymer support layer ( 12) comprising a second gas barrier layer (14) of SiO _X coated on top of the polymer layer (15) comprising at least a first (15a) and a second (15b) partial layer, The first partial layer has higher rigidity than the second partial layer, the second partial layer has higher elastomeric properties than the first partial layer, and the intermediate layer (15) is A method for producing a laminate for packaging, laminated between a first and second gas barrier coated polymer carrier layer, comprising:
Sending a first web (331) and a second web (334) towards each other and towards a first extrusion station (337), wherein the first web (331) is a first A second polymer comprising a first polymer support layer (332) covered by a SiO _X gas barrier layer (333), wherein the second web (334) is covered by a second SiO _X gas barrier layer (336) Including a support layer (335);
By co-extruding the partial layers (15a, 15b, 15c, 15d) of the intermediate polymer layer (338), the first web (331) and the second web (334) can optionally be Laminate with a binder layer (339) on each side of the intermediate polymer layer (338) between the first web and the second web and press the webs together at the extrusion station (337). And steps to
By applying heat and pressure at a first hot roller nip (341 '), a first pre-made film (342') is placed outside the first and second polymer-carrying layers (332 or 335). Laminating, wherein the first prefabricated film (342 ′) comprises at least one heat-sealable polyolefin layer;
By applying heat and pressure at a second hot roller nip (344 '), a second pre-made film (345') is applied to the other of the second and first polymer support layers (335 or 332). And wherein the second prefabricated film (345 ') comprises at least one heat-sealable polyolefin layer. It said first web (331) and said second web (334) is, the gas barrier layer of the SiO _X (333,336) is sent towards each other so as to face each other, The method of claim 34. The gas barrier layer (333) and the second SiO _X gas barrier layer of the first SiO _X is (336), are processed by a surface activation treatment before being laminated, the method according to claim 34.   The method according to claim 36, wherein the surface activation treatment is a corona treatment. A heat sealable olefin polymer outer layer (16, 17), a first gas barrier layer (13) of SiO _X coated on the first polymer support layer (11), and a second polymer support layer ( 12) comprising a second gas barrier layer (14) of SiO _X coated on top and an intermediate polymer layer (15) comprising at least first (15a) and second (15b) partial layers, The first partial layer has higher rigidity than the second partial layer, the second partial layer has higher elastomeric properties than the first partial layer, and the intermediate layer (15) is A method for producing a laminate for packaging, laminated between a first and second gas barrier coated polymer carrier layer, comprising:
Feeding a first web (331) and a second web (334) towards each other and towards a first hot roller nip (337), said first web (331) being a first A second polymer support layer (332) covered by a second SiO _X gas barrier layer (333), wherein the second web (334) is covered by a second SiO _X gas barrier layer (336). Including a polymer support layer (335);
The intermediate pre-manufactured web (338 ') is fed between the first web (331) and the second web (334) and heat and pressure are applied at the first hot roller nip (337'). Laminating the first web (331) and the second web (334) to the intermediate prefabricated web (338 ') by adding the intermediate prefabricated web (338 ') comprising an intermediate polymer layer (338') and optionally a tie layer (339 ') on both sides of said intermediate polymer layer (338');
By applying heat and pressure at a second hot roller nip (341 '), a first pre-made film (342') is placed outside the first and second polymer support layers (332 or 335). Laminating, wherein the first prefabricated film (342 ′) comprises at least one heat-sealable polyolefin layer;
By applying heat and pressure at a third hot roller nip (344 '), a second pre-made film (345') is applied to the other of the second and first polymer support layers (335 or 332). And wherein the second prefabricated film (345 ') comprises at least one heat-sealable polyolefin layer. It said first web (331) and said second web (334) is, the gas barrier layer of the SiO _X (333,336) is sent towards each other so as to face each other, The method of claim 38. The gas barrier layer (333) and the gas barrier layer of the second SiO _X of the first SiO _X is (336), are processed by a surface activation treatment before being laminated, the method according to claim 38.   41. The method of claim 40, wherein the surface activation treatment is a corona treatment.

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