JP6036918B1 - Laminated body and packaging container using the same - Google Patents

Abstract

A laminate having an innermost layer with low adsorptivity and less odor and a packaging container using the same are provided. The laminated body includes a paper base layer, a biaxially oriented polyester layer laminated on the surface, and a polyolefin layer laminated between the base material layer and the biaxially oriented polyester layer. The packaging container is formed by giving heat sealability to a predetermined area of a blank formed by punching the laminate, bending the blank into a box shape, and stacking the end portions and heat-sealing. [Selection] Figure 1

Description

  The present invention relates to a laminate and a packaging container using the same.

  A laminate obtained by laminating a paper base layer, a thermoplastic resin sealant layer, and a barrier layer such as an aluminum foil or aluminum vapor deposited film between them is folded into a box shape, A paper packaging container manufactured by overlapping parts and heat-sealing is known. There are various forms of such a paper packaging container, but there are a brick type (Patent Document 1) having a rectangular parallelepiped shape and a gable top type (Patent Document 2) having a gable roof type roof plate. Widely known. For the sealant layer used in the laminate, a polypropylene resin or a polyethylene resin is often used because of its high heat sealability.

JP-A-7-89535 JP 2012-166696 A

  Polypropylene resins and polyethylene resins have a property of adsorbing various substances, and therefore, when this resin is used for the sealant layer, which is the innermost layer, components contained in the contents are adsorbed, which may cause deterioration in quality. Moreover, since these materials emit odor, the quality may be deteriorated depending on the properties of the contents.

  This invention is made | formed in view of the said subject, and it aims at providing the laminated body which has the innermost layer with low adsorptivity and few odors, and a packaging container using the same.

One aspect of the present invention for solving the above problems is a paper base material layer, a biaxially stretched polyester layer laminated on the surface, and a polyolefin laminated between the base material layer and the biaxially stretched polyester layer. look including a layer, a laminate biaxially oriented polyester layer is the innermost layer of the packaging container, a part of the area of the biaxially oriented polyester layer having heat sealability, a laminate.

In addition, another aspect of the present invention is a packaging container including the above-described laminated body, and having an end portion heat-sealed as the partial region of the biaxially stretched polyester layer .

  ADVANTAGE OF THE INVENTION According to this invention, even if it bends, a laminated body and a packaging container using the same which a biaxially-oriented polyester layer does not peel from a base material layer can be provided.

Sectional drawing of the laminated body which concerns on one Embodiment of this invention The perspective view of the packaging container which concerns on one Embodiment of this invention The top view of the blank of the packaging container concerning one embodiment of the present invention Sectional drawing showing the state of the laminate before and after heat sealing

  Below, the laminated body 100, 101, 102 and the packaging container 200 which concern on embodiment with reference to figures are demonstrated. FIG. 1 is a cross-sectional view of the laminates 100, 101, and 102. Elements that are the same or correspond between the embodiments are assigned the same reference numerals, and descriptions thereof are omitted as appropriate.

(Laminate)
<First Embodiment>
As shown in FIG. 1A, the laminate 100 according to the first embodiment includes a printed layer 110 / surface polyolefin layer 120 / paper substrate layer 130 / intermediate polyolefin layer 140/2 axis in order from the outer layer to the inner layer. An oriented polyester layer 150 is laminated.

  The print layer 110 is formed on the outer layer of the surface polyolefin layer 120, and can display a pattern and product information on the outer layer of the laminate 100. An overcoat layer may be provided on the outer layer of the printed layer 110 in order to improve wear resistance or surface decoration.

  Surface polyolefin layer 120 is an acid copolymer such as linear low density polyethylene resin (LLDPE), low density polyethylene resin (LDPE), ethylene / methacrylic acid copolymer (EMAA), ethylene / acrylic acid copolymer (EAA), It is formed on the outer layer of the paper substrate layer 130 by extrusion lamination or the like using an ester copolymer such as ethylene / methyl acrylate copolymer (EMA) or ionomer (ION), modified polyethylene or the like. The surface polyolefin layer 120 may be subjected to an easy adhesion treatment such as a corona treatment to improve the adhesion with the printed layer 110. The thickness of the surface polyolefin layer 120 is 5 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 20 μm or less.

Paperboard such as milk carton base paper can be used for the paper base layer 130. The basis weight and density can be appropriately selected depending on the capacity and design of the container. From the viewpoint of sufficient rigidity and resource saving, the basis weight is preferably 200 g / m ² or more and 500 g / m ² or less. For example, when used for a 2 liter packaging container, a basis weight of around 400 g / m ² is suitable. The printing layer 110 may be directly formed on the outer layer of the paper base layer 130, and the surface polyolefin layer 120 may be formed on the outer layer.

The intermediate polyolefin layer 140 may be made of an acid copolymer such as LLDPE, LDPE, EMAA, or EAA, an ester copolymer such as EMA or ION, a modified polyethylene, or the like. Among these, LLDPE having a density of 0.920 g / cm ³ or less is preferable. Examples of the forming method on the paper base material layer 130 include a method of forming by dry lamination using a urethane adhesive, a method of forming by extrusion lamination, a method combining these, and the like. In order to obtain the effect described later, the thickness of the intermediate polyolefin layer 140 is preferably 10 μm or more.

  The biaxially oriented polyester layer 150 is formed on the inner layer of the intermediate polyolefin layer 140 using, for example, biaxially oriented polyethylene terephthalate (PET). An anchor coating agent may be used between the intermediate polyolefin layer 140 and the biaxially oriented polyester layer 150, or the anchor coating agent may not be used by performing corona treatment on the biaxially oriented polyester layer 150. The thickness of the biaxially oriented polyester layer 150 is preferably 6 μm or more and 25 μm or less.

<Second Embodiment>
As shown in FIG. 1 (b), the laminate 101 according to the second embodiment has a printing layer 110 / surface polyolefin layer 120 / paper base material layer 130 / intermediate polyolefin layer 140 / barrier layer in order from the outer layer to the inner layer. A 160 / 2-axis oriented polyester layer 150 is laminated. The difference between the laminate 101 and the laminate 100 is that a barrier layer 160 is further provided between the intermediate polyolefin layer 140 and the biaxially oriented polyester layer 150.

  For the barrier layer 160, a metal foil such as aluminum, or an inorganic oxide such as alumina or silica (silicon oxide) can be used. As a forming method on the biaxially oriented polyester layer 150, there are a method of dry laminating a metal foil on the biaxially oriented polyester layer 150, a method of depositing an inorganic oxide on the biaxially oriented polyester layer 150, and the like.

  By providing the barrier layer 160, the stacked body 101 can have a higher gas barrier property than the stacked body 100.

<Third Embodiment>
As shown in FIG. 1C, the laminate 102 according to the third embodiment includes, in order from the outer layer to the inner layer, a printing layer 110 / surface polyolefin layer 120 / paper base material layer 130 / intermediate polyolefin layer 140 / barrier layer. 160 / film base material layer 170 / intermediate polyolefin layer 140/2 biaxially oriented polyester layer 150 are laminated. The difference between the laminate 102 and the laminate 100 is that a barrier layer 160 and a film substrate layer 170 are further provided between the paper substrate layer 130 and the intermediate polyolefin layer 140.

  For the film base layer 170, a resin film such as PET, nylon, or polypropylene can be used. The barrier layer 160 can be laminated on the film base layer 170 by the above-described method. In particular, biaxially oriented PET is suitable because it has little expansion and contraction during vapor deposition and bonding.

(Packaging container)
FIG. 2 is a perspective view of a packaging container 200 according to an example. The packaging container 200 shown in FIG. 2 gives heat sealability to the seal part 290 of the blank 300 shown in FIG. 3 formed by punching one of the laminates 100, 101, and 102, and is bent into a box shape. The end portions are overlapped and the seal portion 290 is formed by heat sealing. The packaging container 200 includes a top part 201 that is an upper part when standing upright, a body part 220 that is a side surface, and a bottom part 230 that is a lower part. The top part 210 is folded between the two roof boards 240 and the roof boards 240. This is a gable-top type paper packaging container including a folded plate 250 and a folded plate 260.

  FIG. 3 is a plan view of the blank 300 of the packaging container 200. The blank 300 includes a pair of a roof plate 240, a folding plate 250, and a folded plate 260 that constitute the top portion 210, four side plates 270 that constitute the trunk portion 220, a bottom plate 280 that constitutes the bottom portion 230, and an end portion. And a seal portion 290 indicated by hatching. The blank 300 is bent in accordance with the one-dot chain line shown in FIG. 3, and the blank 300 is formed in a box shape by heat-sealing the seal portion 290 to the end portion on the opposite side.

  Since the film having orientation usually has poor heat sealability, it is preferable that the biaxially oriented polyester layer 150 improves the heat sealability at least in the seal portion 290 by a predetermined method. As a method for improving the heat sealability, for example, an electromagnetic irradiation method as described in Japanese Patent Publication No. 4-26339 may be used, or other known methods may be used. Further, other new methods such as laser light irradiation may be used.

  As a heat sealing method, methods such as impulse sealing, hot air, ultrasonic sealing, and high frequency sealing can be used.

  FIG. 4 is a cross-sectional view of the A-A ′ range of FIG. For ease of understanding, only the paper base layer 130, the intermediate polyolefin layer 140, and the biaxially oriented polyester layer 150 are shown in the laminate. The blank 300 has an intermediate polyolefin layer 140 between the paper base layer 130 and the biaxially oriented polyester layer 150. Therefore, as shown in FIG. 4 (a), when forming the packaging container 200, when the blank 300 is bent and pressed in the direction of the arrow to perform heat sealing, as shown in FIG. 4 (b), The biaxially oriented polyester layer 150 is sealed, and the intermediate polyolefin layer 140 that is fluidized by heat is deformed and fluidized so as to fill between the paper base material layer 130 and the biaxially oriented polyester layer 150. As a result, the biaxially oriented polyester layer 150 can be prevented from peeling from the paper base material layer 130. Thus, even if the biaxially oriented polyester cannot follow the folded shape of the laminate due to its low fluidity, the provision of the intermediate polyolefin layer 140 prevents the formation of a gap, It can form suitably.

(Modification)
The laminate includes a paper base layer, a biaxially oriented polyester layer laminated on the surface, and a polyolefin layer laminated between the base material layer and the biaxially oriented polyester layer. Various layers can be added depending on the function of the.

  The form of the packaging container is not limited to the gable-top type paper packaging container, but heat sealability is imparted to a predetermined area of the blank formed by punching the laminate, the blank is bent into a box shape, and the end portion is As long as the packaging container is formed by overlapping and heat-sealing, various forms such as a regular tetrahedron type and a rectangular parallelepiped type can be adopted.

  As described above, according to the present invention, it is possible to provide a packaging container that can suppress the adsorption amount of a specific substance to a low level as compared with a laminate using polyethylene or polypropylene as an innermost layer. In addition, it is possible to provide a packaging container in which the biaxially oriented polyester layer does not peel even when it is bent and heat sealed.

  The laminates according to Examples and Comparative Examples 1 to 3 were prepared, and evaluation of sealing performance, adsorptivity, and odor when a gable-top type packaging container and a three-side sealed packaging bag could be created using each laminate. went.

(Example)
In the laminated body according to the example, LDPE (20 μm) / paper (400 g / m ² ) / EMAA (20 μm) / silica vapor-deposited PET (12 μm) / LLDPE (40 μm) / biaxially oriented PET (12 μm) was sequentially formed from the outer layer to the inner layer. It was formed by laminating. Silica-deposited PET, LLDPE, and biaxially oriented PET were bonded together by dry lamination. Further, when manufacturing the packaging container and the packaging bag, heat sealability was imparted by irradiating the innermost layer with a laser irradiation using a carbon dioxide laser device under scanning conditions with an output of 20 W and a drawing speed of 3000 mm / sec.

(Comparative Example 1)
The laminate according to Comparative Example 1 was formed by laminating LDPE (20 μm) / paper (400 g / m ² ) / EMAA (20 μm) / silica vapor-deposited PET (12 μm) / LLDPE (60 μm) in order from the outer layer to the inner layer. Silica-deposited PET and LLDPE were bonded together by dry lamination. The difference from the examples is that the innermost layer is not provided with biaxially oriented PET and laser irradiation is not performed.

(Comparative Example 2)
The laminate according to Comparative Example 2 is formed by laminating LDPE (20 μm) / paper (400 g / m ² ) / EMAA (20 μm) / silica vapor-deposited PET (12 μm) / biaxially oriented PET (60 μm) in order from the outer layer to the inner layer. did. Silica vapor-deposited PET and biaxially oriented PET were bonded together by dry lamination. Further, when manufacturing the packaging container and the packaging bag, laser irradiation was performed at a planned sealing position of the innermost layer using a carbon dioxide laser device under conditions of an output of 20 W and a drawing speed of 3000 mm / second. The difference from the examples is that no LLDPE is provided between silica-deposited PET and biaxially oriented PET.

(Comparative Example 3)
The laminate according to Comparative Example 3 has an LDPE (20 μm) / paper (400 g / m ² ) / EMAA (20 μm) / silica vapor deposited PET (12 μm) / LLDPE (40 μm) / biaxially oriented PET (12 μm) in order from the outer layer to the inner layer. Were laminated. Silica vapor-deposited PET and biaxially oriented PET were bonded together by dry lamination. The difference from the example is that laser irradiation is not performed.

(Seal performance evaluation)
The laminates according to the example and the comparative examples 1 to 3 were each processed into the shape of the blank 300 shown in FIG. 3 so that the bottom portion 230 was 85 mm square and the capacity of the packaging container was 2 liters. Then, the sealing part 290 of the blank 300 was heat-sealed to obtain a packaging container. For each of the examples and comparative examples 1 to 3, 100 packaging containers were prepared, and leakage was confirmed with a check solution. The heat seal set temperature at this time was 400 ° C for the first oven and 360 ° C for the second oven.

  In the packaging container using the laminated body of the example and the comparative example 1, the leakage of the check solution did not occur. In the packaging container using the laminate of Comparative Example 2, biaxially oriented PET peeled from the paper, and leakage occurred in 55 of 100 packaging containers. Moreover, in the packaging container using the laminated body of the comparative example 3, sufficient sealing strength was not obtained and the leakage of the check solution occurred in all the packaging containers.

(Adsorbability evaluation)
The laminated bodies according to Examples and Comparative Examples 1 to 3 were each processed to be a blank of a 100 mm square three-sided seal packaging bag. Thereafter, 100 ml of limonene was sealed, the outer edge was heat sealed, and the sealed packaging bag was stored at 40 ° C. for 1 week. The amount of limonene adsorbed was measured based on the change in weight of the packaging bag before and after storage.

  The amount of limonene adsorbed on the packaging bag using the laminate of Comparative Example 1 was 1, and the amount of limonene adsorbed on the packaging bag using the laminate of Examples and Comparative Example 2 was 0.3. The packaging bag using the laminate of Comparative Example 3 was not evaluated because it was not sufficiently sealed and liquid leakage occurred.

(Odor evaluation)
The laminated bodies according to Examples and Comparative Examples 1 to 3 were each processed to be a blank of a 150 mm square three-sided seal packaging bag. Thereafter, 200 ml of distilled water was sealed, the outer edge was heat sealed, and the sealed packaging bag was stored at 60 ° C. for 24 hours. Then, the packaging bag was returned to normal temperature and sensory evaluation was performed about the presence or absence of the odor adsorbed by distilled water by 10 panelists.

  The odor was not confirmed in the packaging bags using the laminates of the example and the comparative example 2, but the odor was confirmed in the packaging bags using the laminate of the comparative example 1. The packaging bag using the laminate of Comparative Example 3 was not evaluated because it was not sufficiently sealed and liquid leakage occurred.

  The results of the above evaluation are shown in Table 1. In the result of the sealing performance evaluation, the number of the packaging containers in which the leakage of the check solution has occurred with respect to the number of the created packaging containers is indicated by (number of leaks / number of the created packaging containers). The results of the adsorptive evaluation include the amount of limonene adsorbed by the packaging bag using the laminate of Example and Comparative Example 2 when the amount of limonene adsorbed by the packaging bag using the laminate of Comparative Example 1 is 1. (Weight ratio).

  It was confirmed that the packaging container and the packaging bag using the laminate of the example had sufficient sealing performance, the adsorptivity of the contents was suppressed, and no odor was generated.

  On the other hand, in the packaging container and packaging bag using the laminate of Comparative Example 1, LLDPE was used as the innermost layer, so that the amount of contents adsorbed on the laminate was large, and the generation of odor was confirmed.

  Moreover, in the packaging container and packaging bag using the laminated body of Comparative Example 2, since the polyolefin layer is not provided between the paper and the biaxially oriented PET, the biaxially oriented PET peels off from the paper and the sealing performance is sufficient. It was confirmed that it could not be secured.

  Moreover, in the packaging container and packaging bag using the laminated body of Comparative Example 3, it was confirmed that the sealing performance could not be sufficiently ensured because laser irradiation was not performed on the planned sealing site of the biaxially oriented PET.

  The present invention is useful for packaging containers and the like.

100, 101, 102 Laminate 110 Print layer 120 Surface polyolefin layer 130 Paper substrate layer 140 Intermediate polyolefin layer 150 Biaxially oriented polyester layer 160 Barrier layer 170 Film substrate layer 200 Packaging container 210 Top portion 220 Body portion 230 Bottom portion 240 Roof plate 250 Folding plate 260 Folding plate 270 Side plate 280 Bottom plate 290 Seal part 300 Blank

Claims (4)

A substrate layer made of paper and biaxially oriented polyester layer laminated on the surface, seen including a laminated polyolefin layer between the base layer and the biaxially oriented polyester layer, wherein the biaxially oriented polyester layer Is a laminate that is the innermost layer of the packaging container,
A laminate in which a part of the biaxially stretched polyester layer has heat sealability .   The laminate according to claim 1, further comprising a barrier layer having gas barrier properties between the base material layer and the biaxially stretched polyester layer.   The laminate according to claim 1 or 2, wherein the biaxially stretched polyester layer uses biaxially stretched polyethylene terephthalate as a biaxially stretched polyester. A packaging container comprising the laminate according to any one of claims 1 to 3, wherein an end portion is heat-sealed as the partial region of the biaxially stretched polyester layer .

Images