Caps and packaging containers

Abstract

To provide caps and packaging containers that offer both recyclability and barrier properties. [Solution] A cap to be attached to the mouth of a container body, comprising: a top surface, an outer skirt portion connected to the edge of the top surface, and an inner skirt portion disposed inside the outer skirt portion; and a cylindrical inner ring provided inside the top surface and capable of fitting with the inner circumferential surface of the mouth, wherein the top surface includes a first barrier layer provided in the intermediate layer inside the inner ring, the inner ring includes a second barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the first barrier layer, and the intermediate layer of the outer skirt portion does not have a barrier layer.

Description

Technical Field

[0001] The present invention relates to a cap having barrier properties and a packaging container using the same.

Background Art

[0002] In a packaging container for storing cosmetics, pharmaceuticals, etc., in order to suppress deterioration of the contents, it is necessary to prevent intrusion of oxygen from the cap side and volatilization of the contents. Therefore, in a resin packaging container, the barrier properties of the cap have been enhanced by increasing the wall thickness of the cap, attaching a barrier packing to the cap, etc.

[0003] However, increasing the wall thickness of the cap increases the amount of resin used, which is not preferable from the viewpoints of reducing environmental load and resource protection. Also, using packing or aluminum impairs the material unity of the cap and the container body, resulting in a decrease in recyclability, which is not preferable.

[0004] From this, a method of enhancing barrier properties by providing a barrier layer in the intermediate layer of the cap has been studied without increasing the thickness of the cap or using packing (Patent Documents 1 to 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, a high proportion of barrier material in resin products leads to a decrease in recyclability. Therefore, it is preferable to reduce the amount of barrier material used in resin caps with a barrier layer.

[0007] This invention has been made in view of the above problems, and aims to provide a cap and packaging container that achieves both recyclability and barrier properties. [Means for solving the problem]

[0008] One aspect of the present invention for solving the above problems is a cap attached to the mouth of a container body, comprising a top surface, an outer skirt portion connected to the edge of the top surface, and an inner skirt portion disposed inside the outer skirt portion, and a cylindrical inner ring provided inside the top surface and fitted to the inner circumferential surface of the mouth, wherein the top surface includes a first barrier layer provided in the intermediate layer inside the inner ring, the inner ring includes a second barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the first barrier layer, and the intermediate layer of the outer skirt portion does not have a barrier layer.

[0009] Another aspect of the present invention is a cap attached to the mouth of a container body, comprising a top surface, a skirt portion extending vertically from the edge of the top surface, and a cylindrical inner ring provided on the inside of the top surface and capable of fitting with the inner circumferential surface of the mouth, wherein the top surface includes a first barrier layer provided in the intermediate layer inside the inner ring, the inner ring includes a second barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the first barrier layer, and the intermediate layer of the skirt portion and the intermediate layer of the top surface located outside the inner ring are not provided with a barrier layer.

[0010] Another aspect of the present invention is a packaging container comprising the cap and container body, wherein the container body has a bottom portion and a side wall portion extending vertically from the edge of the bottom portion and forming a mouth portion, the bottom portion includes a fifth barrier layer provided in the intermediate layer over its entire surface, and the side wall portion includes a sixth barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the fifth barrier layer, and in a side view with the cap attached to the container body, the second barrier layer and the sixth barrier layer overlap. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a cap and packaging container that achieve both recyclability and barrier properties. [Brief explanation of the drawing]

[0012] [Figure 1] Plan view showing the schematic configuration of the cap according to the first embodiment. [Figure 2] Cross-sectional view showing the schematic configuration of the packaging container according to the first embodiment. [Figure 3] Figure 2 shows a magnified view of the inner ring, inner skirt, and the area around the opening. [Figure 4] Plan view showing the schematic configuration of the cap according to the second embodiment. [Figure 5] Cross-sectional view showing the schematic configuration of the packaging container according to the second embodiment. [Figure 6] Figure 5 shows a magnified view of the inner ring and the area around the opening. [Figure 7] Cross-sectional view showing the schematic configuration of a packaging container related to the example. [Modes for carrying out the invention]

[0013] [First Embodiment] <Structure> Figure 1 is a plan view showing the schematic configuration of the cap according to the first embodiment, Figure 2 is a cross-sectional view showing the schematic configuration of the packaging container according to the first embodiment, and Figure 3 is a magnified view of the inner ring, inner skirt portion, and mouth area in Figure 2. In Figure 1, for convenience, the areas where the first barrier layer 31 and the third barrier layer 33 are formed are shown with hatching on the surface of the cap 1, and the areas where the second barrier layer 32 and the fourth barrier layer 34 are formed are shown with dashed lines on the surface of the cap 1.

[0014] The packaging container 100 according to the first embodiment comprises a cap 1 and a container body 2, and contains contents such as cosmetics, pharmaceuticals, and food. In the packaging container 100 according to this embodiment, barrier properties are provided by providing a barrier layer on the cap 1 and the container body 2. As a result, it is thinner than a general packaging container made only of resin, and the amount of resin used can be reduced. Furthermore, by selectively providing the barrier layer, the proportion of barrier material is reduced, thereby improving recyclability.

[0015] (cap) The cap 1 is a resin member attached to the mouth portion 5 of the container body 2 and closing the packaging container 100. The cap 1 includes a top surface portion 11, a cylindrical skirt portion 12, and a cylindrical inner ring 13 provided inside the top surface portion 11. The skirt portion 12 specifically consists of an outer skirt portion 12a connected to the edge of the top surface portion 11 and an inner skirt portion 12b disposed inside the outer skirt portion 12a. A first barrier layer 31 and a third barrier layer 33 are provided in the intermediate layer of the top surface portion 11, a second barrier layer 32 is provided in the intermediate layer of the inner ring 13, and a fourth barrier layer 34 is provided in the intermediate layer of the inner skirt portion 12b. Hereinafter, the first barrier layer 31 to the fourth barrier layer 34 may be simply referred to as barrier layers. As the resin serving as the base of the cap 1, for example, polypropylene (PP) or polyethylene (PE) can be used, and as the barrier layer, ethylene-vinyl alcohol copolymer (EVOH) or barrier nylon can be used. In the present embodiment, since the barrier layer is selectively provided on the cap 1 (specifically, only inside the inner skirt portion 12b of the top surface portion 11, the entire circumference of the inner ring 13, and the entire circumference of the inner skirt portion 12b), while imparting barrier properties to the cap 1, the ratio of the barrier material to the resin can be suppressed, and both barrier properties and recyclability can be achieved simultaneously.

[0016] The top surface portion 11 is a flat plate-like member and includes a first barrier layer 31 and a third barrier layer 33 in the intermediate layer. The first barrier layer 31 is provided on the entire surface of the portion of the top surface portion 11 inside the inner ring 13, and the third barrier layer 33 is provided so as to surround the first barrier layer 31 in a plan view. At this time, the first barrier layer 31 and the third barrier layer 33 are connected to the second barrier layer 32 provided on the inner skirt portion 12b. Specifically, the second barrier layer 32 is connected to the entire circumference of the first barrier layer 31, and the third barrier layer 33 is connected to the entire circumference of the second barrier layer 32. On the other hand, no barrier layer is provided in the intermediate layer of the portion of the top surface portion 11 outside the outer skirt portion 12a. Also, the shape of the top surface portion 11 can be, for example, circular, but other shapes may also be acceptable.

[0017] Also, a barrier layer may be included in the region between the inner skirt portion 12b and the outer skirt portion 12a on the top surface portion 11 (not shown). However, even if a barrier layer is included in this region, its contribution to the barrier property is small, and the recyclability also decreases. Therefore, as shown in FIG. 2, it is preferable that the region outside the inner skirt portion 12b of the cap 1 does not include a barrier layer.

[0018] The skirt portion 12 is a cylindrical member extending vertically from the edge of the top surface portion 11, and is composed of an outer skirt portion 12a connected to the edge of the top surface portion 11 and an inner skirt portion 12b disposed inside the outer skirt portion 12a. The inner skirt portion 12b includes a fourth barrier layer 34 provided in the intermediate layer of its entire circumference and connected to the entire circumference of the third barrier layer 33. The edge of the fourth barrier layer 34 on the side opposite to the top surface portion 11 is preferably located farther from the top surface portion 11 than the edge of the inner ring 13. That is, in the paper surface direction of FIG. 2, the edge of the fourth barrier layer 34 is preferably located below the edge of the inner ring 13.

[0019] On the other hand, in the present embodiment, the outer skirt portion 12a does not include a barrier layer. Thereby, it is possible to suppress the occurrence of peeling (lifting between resins) between the resin constituting the cap 1 and the barrier layer due to the external force applied to the skirt portion 12 when the cap 1 is opened and closed. When lifting between resins occurs, peeling of the surface resin occurs, and the exposed barrier layer may absorb moisture and the barrier property may decrease, or an appearance defect may occur. In order to suppress the lifting between resins that occurs when the cap 1 is opened and closed, it is only necessary that the outer skirt portion 12a does not contain a barrier layer.

[0020] The inner circumferential surface of the inner skirt portion 12b is provided with a male thread 6a that engages with the female thread 6b provided on the outer circumferential surface of the mouth portion 5 of the container body 2. This allows the cap 1 and the container body 2 to be fitted together by screwing. Alternatively, the inner skirt portion 12b may be omitted, and the male thread 6a may be provided on the inner circumferential surface of the outer skirt portion 12a. However, if the skirt portion 12 is composed only of the outer skirt portion 12a, it is necessary to make the skirt portion 12 thicker to suppress deformation of the cap 1, in order to suppress the floating between the resins as described above. For this reason, a double structure of inner skirt portion 12b and outer skirt portion 12a is preferable in that it can reduce the amount of resin used for the skirt portion 12. Furthermore, providing the outer skirt portion 12a is preferable from the viewpoint of ease of opening, as it makes it less likely for the male thread 6a to deform when gripping and rotating the cap 1.

[0021] Furthermore, as long as the cap 1 can be attached to the container body 2, the method is not limited to screwing. For example, a convex portion may be formed on the inner circumferential surface of the skirt portion 12 to fit with the container body 2 via an undercut. In this case as well, the inner skirt portion 12b may be omitted as appropriate.

[0022] The inner ring 13 is located inside the top surface 11 and fits with the inner circumferential surface of the mouth 5 of the container body 2 to create a sealed state for the packaging container 100. The intermediate layer around the entire circumference of the inner ring 13 includes a second barrier layer 32 that is connected to the entire circumference of the first barrier layer 31 of the top surface 11. The barrier layer in the cap 1 is unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2 (Figure 2). By unevenly distributing the second barrier layer 32 in this way, the barrier layer can be formed up to near the end of the inner ring 13.

[0023] (Container body) The container body 2 is not particularly limited as long as it has a mechanism that allows it to be fitted with the cap 1, but in this embodiment, it is a wide-mouthed jar container. In this case, the container body 2 comprises a flat bottom portion 21, a side wall portion 22 extending vertically from the edge of the bottom portion 21, a cylindrical outer wall portion 23 positioned outside the side wall portion 22, and a connecting portion 24 connecting the outer wall portion 23 and the side wall portion 22. A fifth barrier layer 35 and a sixth barrier layer 36 are provided in the intermediate layers of the bottom portion 21 and the side wall portion 22, respectively. Hereafter, the fifth barrier layer 35 to the sixth barrier layer 36 may be simply referred to as the barrier layer. The same materials as those used for the cap 1 can be used for the resin that forms the base of the container body 2 and for the barrier layers.

[0024] The bottom portion 21 is a flat plate-shaped member, and includes a fifth barrier layer 35 in the intermediate layer across its entire surface. The shape of the bottom portion 21 can be, for example, circular, but it may also be of other shapes.

[0025] The side wall portion 22 is a cylindrical member extending vertically from the edge of the bottom portion 21, and a mouth portion 5 is provided at the end of the side wall portion 22 opposite to the bottom portion 21, to which the cap 1 is attached. The outer circumferential surface of the mouth portion 5 is provided with a female screw 6b that screws into a male screw 6a provided on the inner circumferential surface of the inner skirt portion 12b of the cap 1. This allows the cap 1 and the container body 2 to be fitted together by screwing. In addition, the intermediate layer around the entire circumference of the side wall portion 22 includes a sixth barrier layer 36 that is connected to the entire circumference of the fifth barrier layer 35 of the bottom portion 21.

[0026] The end of the sixth barrier layer 36 opposite to the bottom portion 21 preferably overlaps with the second barrier layer 32 of the inner ring 13 in a side view (Figure 3). By overlapping the sixth barrier layer 36 and the second barrier layer 32, the barrier properties of the packaging container 100 can be enhanced. Furthermore, the end of the sixth barrier layer 36 opposite to the bottom portion 21 preferably overlaps with the fourth barrier layer 34 of the inner skirt portion 12b in a side view (Figure 3). By overlapping the sixth barrier layer 36 and the fourth barrier layer 34, even if the second barrier layer 32 could not be formed on the inner ring 13 (if the barrier layer could not be formed up to near the tip of the inner ring 13), the housing portion of the packaging container 100 can be surrounded by the first barrier layer 31, the third barrier layer 33, the fourth barrier layer 34, the fifth barrier layer 35, and the sixth barrier layer 36, thereby ensuring barrier properties. Furthermore, from the viewpoint of improving recyclability, it is preferable that the barrier layer is not applied to the female threads 6b of the side wall portion 22, as shown in Figure 1.

[0027] The outer wall portion 23 is a cylindrical member connected to the side wall portion 22 via an annular connecting portion 24. Furthermore, no barrier layer is provided on the outer wall portion 23 or the connecting portion 24. In Figure 2, in a plan view of the closed packaging container 100, the outer wall portion 23 is located outside the skirt portion 12 of the cap 1, but it may also be located at a position coinciding with the outer circumference of the skirt portion 12. Note that the outer wall portion 23 and the connecting portion 24 may be omitted.

[0028] As described above, the container body 2 in this embodiment is provided with a barrier layer to give it barrier properties. However, the barrier layer of the container body 2 may be omitted, and barrier properties may be given to the container body 2 by, for example, increasing the thickness of the container body 2. However, from the viewpoint of reducing the amount of resin used, it is preferable to provide a barrier layer as in this embodiment.

[0029] <Effects> In this embodiment, the cap 1 has barrier layers (first barrier layer 31 and second barrier layer 32) provided in the intermediate layer inside the inner ring 13 of the top surface 11, and in the intermediate layer around the entire circumference of the inner ring 13. The entire circumference of the first barrier layer 31 of the top surface 11 and the entire circumference of the second barrier layer 32 of the inner ring 13 are connected to each other. As a result, the first barrier layer 31 and the second barrier layer 32 of the cap 1 cover the opening of the storage section that holds the contents of the container body 2, preventing oxygen from entering from the cap 1 side and preventing the contents from volatilizing, thereby providing the cap 1 with sufficient barrier properties.

[0030] Furthermore, the cap 1 is provided with barrier layers (third barrier layer 33 and fourth barrier layer 34) in the intermediate layer between the portion outside the inner ring 13 and the inner skirt portion 12b, and in the intermediate layer around the entire circumference of the inner skirt portion 12b, with the first barrier layer 31 to the fourth barrier layer 34 being connected to each other. At this time, the edge of the fourth barrier layer 34 opposite to the top surface portion 11 (the lower end of the fourth barrier layer 34) is located further from the top surface portion 11 than the edge of the inner ring 13. Therefore, even if it is not possible to form a barrier layer near the tip of the inner ring 13, the first barrier layer 31, the third barrier layer 33, and the fourth barrier layer 34 of the cap 1 will cover the opening of the storage portion that holds the contents of the container body 2, thereby providing the cap 1 with sufficient barrier properties.

[0031] On the other hand, the outer skirt portion 12a is not provided with a barrier layer. Even if a barrier layer were formed on the outer skirt portion 12a, it would not significantly contribute to the barrier performance of the packaging container 100, and forming a barrier layer in this area is undesirable because it increases the ratio of barrier material to resin, thereby reducing recyclability. Furthermore, if a barrier layer is formed on the outer skirt portion 12a, external forces applied to the skirt portion 12 during opening and closing may cause delamination (lifting between resins) between the resin constituting the cap 1 and the barrier layer, potentially leading to a decrease in barrier performance and an appearance defect. For these reasons, it is preferable not to form a barrier layer on the outer skirt portion 12a.

[0032] Thus, the cap 1 in this embodiment can provide barrier properties to the cap 1 while keeping the ratio of barrier material to resin low, thereby achieving both barrier properties and recyclability.

[0033] Furthermore, in this embodiment, the container body 2 has barrier layers (the fifth barrier layer 35 and the sixth barrier layer 36) on the entire surface of the bottom portion 21 and on the entire circumference of the side wall portion 22. The entire circumference of the fifth barrier layer 35 on the bottom portion 21 and the entire circumference of the sixth barrier layer 36 on the side wall portion 22 are connected to each other. Therefore, by closing the container body 2 with the cap 1, the contents can be surrounded by the first barrier layer 31 to the sixth barrier layer 36, resulting in superior barrier performance. Moreover, when the cap 1 is closed, the barrier layer of the container body 2 (the sixth barrier layer 36) and the barrier layer of the inner ring 13 (the second barrier layer 32) overlap (Figure 3), further enhancing the barrier performance. Furthermore, the barrier layer of the container body 2 (sixth barrier layer 36) overlaps with the barrier layer of the inner skirt portion 12b (fourth barrier layer 34) (Figure 3), further enhancing the barrier properties, and ensuring barrier properties even if a barrier layer cannot be formed on the inner ring 13.

[0034] On the other hand, the outer wall portion 23 and the connecting portion 24 are not provided with a barrier layer. As shown in Figure 7, even if a barrier layer were provided on the outer wall portion 23 and the connecting portion 24, it would not significantly contribute to the barrier performance of the packaging container 100. Therefore, by not providing a barrier layer on the outer wall portion 23 and the connecting portion 24, the ratio of barrier material to resin can be reduced, thereby improving recyclability.

[0035] <Manufacturing method> It is preferable that both the cap 1 and the container body 2 are formed by injection molding. It is also possible to make the packaging container 100 a blow-molded container, but this is undesirable because the barrier layer will be exposed from the cut surface during molding. It is also possible to make the barrier layer a sheet material and form it by insert molding, but this is undesirable because the cost will increase due to the material cost of the sheet material and the increased labor required to manufacture the sheet material.

[0036] When forming the cap 1 and container body 2 by injection molding, the material is fed into the mold in layers of base resin / barrier material / base material. At this time, it is necessary to selectively feed the barrier layer only to predetermined locations, which can be achieved by suitably adjusting the shape of the cap 1 and the injection speed. Furthermore, by making the barrier layer provided in the intermediate layer unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2, the barrier material injected from the gate can advance toward the edge of the inner ring 13, and the barrier layer can be formed up to near the end of the inner ring 13. The gate in injection molding can be located at a position corresponding to the center of the top surface 11 of the cap 1 and the center of the bottom surface 21 of the container body 2.

[0037] As described above, the cap 1 according to this embodiment has a barrier layer in the intermediate layer. This makes it possible to impart barrier properties to the cap 1 without increasing the thickness of the cap 1 or using gaskets or aluminum.

[0038] Furthermore, a first barrier layer 31 is provided on the entire surface inside the inner ring 13 of the top surface 11, a second barrier layer 32 is provided around the entire circumference of the inner ring 13, and the entire circumferences of the first barrier layer 31 and the entire circumference of the second barrier layer 32 are connected to each other. As a result, the barrier layer of the cap 1 can cover the opening of the container body 2's contents storage area, providing the cap 1 with sufficient barrier properties.

[0039] Furthermore, a third barrier layer 33 is provided over the entire area from the outside of the inner ring 13 of the top surface 11 to the inner skirt portion 12b, and a fourth barrier layer 34 is provided around the entire circumference of the inner skirt portion 12b. The entire circumferences of the second barrier layer 32 and the third barrier layer 33, and the entire circumferences of the third barrier layer 33 and the fourth barrier layer 34 are connected to each other. Moreover, the edge of the fourth barrier layer 34 is located further away from the top surface 11 than the edge of the inner ring 13. As a result, even if the second barrier layer 32 cannot be formed on the inner ring 13, the barrier layer of the cap 1 can cover the opening of the container body 2's contents storage area, providing the cap 1 with sufficient barrier properties.

[0040] Furthermore, in the cap 1, at least the outer skirt portion 12a is not provided with a barrier layer. This prevents delamination (lifting of resin layers) from occurring between the resin constituting the cap 1 and the barrier layer due to external forces applied to the skirt portion 12 during opening and closing, which can lead to a decrease in barrier properties and defects in appearance. In addition, the amount of barrier material used can be reduced, thus improving recyclability.

[0041] Furthermore, a barrier layer does not need to be provided in the intermediate layer of the top surface 11 that is outside the outer skirt portion 12a. This further reduces the amount of barrier material used and improves recyclability.

[0042] Furthermore, the barrier layer provided in the intermediate layer of the cap 1 is unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2. This allows the barrier layer to be formed up to near the end of the inner ring 13.

[0043] Furthermore, cap 1 is formed by injection molding. This prevents the barrier layer from being exposed from the cut surface during molding, as is the case with blow molding, and also reduces costs.

[0044] Furthermore, the container body 2 has a fifth barrier layer 35 covering the entire bottom surface 21, a sixth barrier layer 36 covering the entire circumference of the side wall 22, and the entire circumferences of the fifth barrier layer 35 and the sixth barrier layer 36 are connected to each other. As a result, by closing the container body 2 with the cap 1, the contents can be surrounded by the first barrier layer 31 to the sixth barrier layer 36, thereby providing superior barrier properties.

[0045] [Second Embodiment] <Structure> Figure 4 is a plan view showing the schematic configuration of the cap according to the second embodiment, Figure 5 is a cross-sectional view showing the schematic configuration of the packaging container according to the second embodiment, and Figure 6 is a partially enlarged view of the inner ring and the area around the mouth in Figure 5. In Figure 4, for convenience, the area where the first barrier layer 31 is formed is shown with hatching on the surface of the cap 10, and the area where the second barrier layer 32 is formed is shown with a dashed line on the surface of the cap 10.

[0046] The packaging container 200 according to the second embodiment comprises a cap 10 and a container body 2, and contains contents such as cosmetics, pharmaceuticals, and food. In the packaging container 200 according to this embodiment, barrier properties are provided by providing a barrier layer on the cap 10 and the container body 2. As a result, it is thinner than a general packaging container made only of resin, and the amount of resin used can be reduced. Furthermore, by selectively providing the barrier layer, the proportion of barrier material is reduced, thereby improving recyclability. Compared to the packaging container 100 according to the first embodiment, the packaging container 200 according to the second embodiment has even more limited areas where the barrier layer is provided, resulting in even higher recyclability.

[0047] (cap) The cap 10 is a resin component attached to the mouth 5 of the container body 2 to close the packaging container 200. The cap 10 comprises a top surface portion 11, a cylindrical skirt portion 12 extending vertically from the edge of the top surface portion 11, and a cylindrical inner ring 13 provided inside the top surface portion 11. A first barrier layer 31 and a second barrier layer 32 (hereinafter sometimes simply referred to as the barrier layer) are provided in the intermediate layers of the top surface portion 11 and the inner ring 13, respectively. For example, polypropylene (PP) or polyethylene (PE) can be used as the base resin of the cap 10, and ethylene-vinyl alcohol copolymer (EVOH) or barrier nylon can be used as the barrier layer. In this embodiment, since the barrier layer is selectively provided on the cap 10 (specifically, only inside the inner ring 13 of the top surface portion 11 and around the entire circumference of the inner ring 13), the ratio of barrier material to resin can be kept to a minimum while providing barrier properties to the cap 10, making it possible to achieve both barrier properties and recyclability.

[0048] The top surface portion 11 is a flat plate-shaped member and includes a first barrier layer 31 in the intermediate layer of the portion inside the inner ring 13. The first barrier layer 31 is provided over the entire surface of the top surface portion 11 inside the inner ring 13. On the other hand, the intermediate layer of the top surface portion 11 outside the inner ring 13 does not have a barrier layer. The shape of the top surface portion 11 can be, for example, circular, but it may also be of other shapes.

[0049] The skirt portion 12 is a cylindrical member that extends vertically from the edge of the top surface portion 11. In this embodiment, the skirt portion 12 does not have a barrier layer and is composed of an outer skirt portion 12a connected to the edge of the top surface portion 11 and an inner skirt portion 12b positioned inside the outer skirt portion 12a. Because the barrier layer is not included in the outer skirt portion 12a, it is possible to suppress delamination (lifting of resin) between the resin constituting the cap 10 and the barrier layer due to external forces applied to the skirt portion 12 when opening and closing. If lifting of resin occurs, the resin on the surface will peel off, and the exposed barrier layer may absorb moisture, reducing its barrier properties or causing an appearance defect.

[0050] The inner circumferential surface of the inner skirt portion 12b is provided with a male thread 6a that engages with a female thread 6b provided on the outer circumferential surface of the mouth portion 5 of the container body 2. This allows the cap 10 and the container body 2 to be fitted together by screwing. Alternatively, the inner skirt portion 12b may be omitted and the male thread 6a may be provided on the inner circumferential surface of the outer skirt portion 12a. However, providing the outer skirt portion 12a is preferable because it makes it less likely for the male thread 6a to deform when gripping and rotating the cap 10, making it easier to open. Furthermore, if the skirt portion 12 is composed only of the outer skirt portion 12a, it is necessary to make the skirt portion 12 thicker to suppress deformation of the cap 10. However, the double configuration of the inner skirt portion 12b and the outer skirt portion 12a is preferable because it reduces the amount of resin used for the skirt portion 12. Note that as long as the cap 10 can be attached to the container body 2, the method is not limited to screwing. For example, a convex portion may be formed on the inner circumferential surface of the skirt portion 12 to fit with the container body 2 by undercutting. In this case as well, the inner skirt portion 12b can be omitted as appropriate.

[0051] The inner ring 13 is provided on the inside of the top surface 11 and fits with the inner circumferential surface of the mouth 5 of the container body 2 to create a sealed state for the packaging container 200. The intermediate layer around the entire circumference of the inner ring 13 includes a second barrier layer 32 that is connected to the entire circumference of the first barrier layer 31 of the top surface 11. The barrier layer in the cap 10 is unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2 (Figure 4). By unevenly distributing the second barrier layer 32 in this way, the barrier layer can be formed up to near the end of the inner ring 13.

[0052] (Container body) The container body 2 is not particularly limited as long as it has a mechanism that allows it to be fitted with the cap 10, but in this embodiment, it is a wide-mouthed jar container. In this case, the container body 2 comprises a flat bottom portion 21, a side wall portion 22 extending vertically from the edge of the bottom portion 21, a cylindrical outer wall portion 23 positioned outside the side wall portion 22, and a connecting portion 24 connecting the outer wall portion 23 and the side wall portion 22. A fifth barrier layer 35 and a sixth barrier layer 36 (hereinafter sometimes simply referred to as barrier layers) are provided in the intermediate layers of the bottom portion 21 and the side wall portion 22, respectively. The same materials as those used for the cap 10 can be used for the resin that forms the base of the container body 2 and for the barrier layers.

[0053] The bottom portion 21 is a flat plate-shaped member, and includes a fifth barrier layer 35 in the intermediate layer across its entire surface. The shape of the bottom portion 21 can be, for example, circular, but it may also be of other shapes.

[0054] The side wall portion 22 is a cylindrical member extending vertically from the edge of the bottom portion 21, and a mouth portion 5 is provided at the end of the side wall portion 22 opposite to the bottom portion 21, to which the cap 10 is attached. The outer circumferential surface of the mouth portion 5 is provided with a female screw 6b that screws into a male screw 6a provided on the inner circumferential surface of the inner skirt portion 12b of the cap 10. This allows the cap 10 and the container body 2 to be fitted together by screwing. Furthermore, the intermediate layer around the entire circumference of the side wall portion 22 includes a sixth barrier layer 36 that is connected to the entire circumference of the fifth barrier layer 35 of the bottom portion 21. The end of the sixth barrier layer 36 opposite to the bottom portion 21 preferably overlaps with the second barrier layer 32 of the inner ring 13 in a side view (Figure 6). By overlapping the sixth barrier layer 36 and the second barrier layer 32, the barrier properties of the packaging container 200 can be enhanced. Furthermore, from the viewpoint of improving recyclability, it is preferable that the barrier layer is not applied to the female threads 6b of the side wall portion 22, as shown in Figure 5.

[0055] The outer wall portion 23 is a cylindrical member connected to the side wall portion 22 via an annular connecting portion 24. Furthermore, no barrier layer is provided on the outer wall portion 23 or the connecting portion 24. In Figure 5, in a plan view of the closed packaging container 200, the outer wall portion 23 is located outside the skirt portion 12 of the cap 10, but it may also be located at a position coinciding with the outer circumference of the skirt portion 12. Note that the outer wall portion 23 and the connecting portion 24 may be omitted.

[0056] As described above, the container body 2 in this embodiment is provided with a barrier layer to give it barrier properties. However, the barrier layer of the container body 2 may be omitted, and barrier properties may be given to the container body 2 by, for example, increasing the thickness of the container body 2. However, from the viewpoint of reducing the amount of resin used, it is preferable to provide a barrier layer as in this embodiment.

[0057] <Effects> In this embodiment, the cap 10 has barrier layers (first barrier layer 31 and second barrier layer 32) provided in the intermediate layer inside the inner ring 13 of the top surface 11, and in the intermediate layer around the entire circumference of the inner ring 13. The entire circumference of the first barrier layer 31 of the top surface 11 and the entire circumference of the second barrier layer 32 of the inner ring 13 are connected to each other. As a result, the barrier layers of the cap 10 cover the opening of the storage section that holds the contents of the container body 2, preventing oxygen from entering from the cap side and preventing the contents from volatilizing, thereby providing the cap 10 with sufficient barrier properties.

[0058] On the other hand, no barrier layer is provided in the intermediate layer inside the inner ring 13 of the top surface 11, and in the intermediate layers other than the intermediate layer around the entire circumference of the inner ring 13. In other words, no barrier layer is provided in the area outside the inner ring 13 of the top surface 11 and in the skirt portion 12. As shown in Figure 5, even if a barrier layer were provided in the area outside the inner ring 13 of the top surface 11 or in the skirt portion 12, it would not significantly contribute to the barrier performance of the packaging container 200. Therefore, by not forming a barrier layer in these areas, it is possible to reduce the ratio of barrier material to resin while maintaining barrier properties, thereby improving recyclability.

[0059] Thus, the cap 10 in this embodiment provides barrier properties to the cap 10 while minimizing the ratio of barrier material to resin, thereby achieving both barrier properties and recyclability.

[0060] Furthermore, in this embodiment, the container body 2 is provided with barrier layers (the fifth barrier layer 35 and the sixth barrier layer 36) on the entire intermediate layer of the bottom surface 21 and the entire circumference of the intermediate layer of the side wall 22, and the entire circumference of the fifth barrier layer 35 of the bottom surface 21 and the entire circumference of the sixth barrier layer 36 of the side wall 22 are connected to each other. Therefore, by closing the container body 2 with the cap 10, the storage area can be surrounded by the first barrier layer 31, the second barrier layer 32, the fifth barrier layer 35 and the sixth barrier layer 36, thereby exhibiting superior barrier properties. Moreover, when the cap 10 is closed, the barrier layer of the container body 2 (the sixth barrier layer 36) and the barrier layer of the inner ring 13 (the second barrier layer 32) overlap (Figure 6), which further enhances the barrier properties.

[0061] On the other hand, the outer wall portion 23 and the connecting portion 24 are not provided with a barrier layer. As shown in Figure 7, even if a barrier layer were provided on the outer wall portion 23 and the connecting portion 24, it would not significantly contribute to the barrier performance of the packaging container 200. Therefore, by not providing a barrier layer on the outer wall portion 23 and the connecting portion 24, the ratio of barrier material to resin can be reduced, thereby improving recyclability.

[0062] <Manufacturing method> It is preferable that both the cap 10 and the container body 2 are formed by injection molding. It is also possible to make the packaging container 200 a blow-molded container, but this is undesirable because the barrier layer will be exposed from the cut surface during molding. It is also possible to make the barrier layer a sheet material and form it by insert molding, but this is undesirable because the cost will increase due to the material cost of the sheet material and the increased labor required to manufacture the sheet material.

[0063] When forming the cap 10 and container body 2 by injection molding, the material is fed into the mold in layers of base resin / barrier material / base material. At this time, it is necessary to selectively feed the barrier layer only to predetermined locations, which can be achieved by suitably adjusting the shape of the cap 10 and the injection speed. Furthermore, by positioning the barrier layer provided in the intermediate layer so that it is unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2, the barrier material injected from the gate can advance toward the edge of the inner ring 13, and the barrier layer can be formed up to near the end of the inner ring 13. The gate in injection molding can be located at a position corresponding to the center of the top surface 11 of the cap 10 and the center of the bottom surface 21 of the container body 2.

[0064] As described above, the cap 10 according to this embodiment has a barrier layer in the intermediate layer. This makes it possible to provide barrier properties to the cap 10 without increasing the thickness of the cap 10 or using gaskets or aluminum.

[0065] Furthermore, a first barrier layer 31 is provided on the entire surface inside the inner ring 13 of the top surface 11, a second barrier layer 32 is provided around the entire circumference of the inner ring 13, and the entire circumferences of the first barrier layer 31 and the entire circumference of the second barrier layer 32 are connected to each other. As a result, the barrier layer of the cap 10 can cover the opening of the container body 2's contents storage area, providing the cap 10 with sufficient barrier properties.

[0066] Furthermore, no barrier layer is provided on the area outside the inner ring 13 on the top surface 11, and on the skirt portion 12. This minimizes the proportion of barrier material to the resin, thereby improving the recyclability of the cap 10.

[0067] Furthermore, the barrier layer provided in the intermediate layer is unevenly distributed towards the inside of the container body 2 with respect to the thickness direction of the container body 2. This allows the barrier layer to be formed up to near the end of the inner ring 13.

[0068] Furthermore, the cap 10 is formed by injection molding. This prevents the barrier layer from being exposed from the cut surface during molding, as can happen with blow molding, and also reduces costs.

[0069] The technical matters described in the first and second embodiments can be adopted in any way, as long as they do not impair the functions of the other. [Examples]

[0070] Packaging containers for Examples 1-2 and Comparative Examples 1-5 were manufactured using the following procedure. The amount of resin in the cap and the capacity of the container body 2 (diameter of the bottom portion 21: 53.81 mm, height of the side wall portion 22: 40.85 mm) were all the same.

[0071] (Example 1) A wide-mouthed jar container according to the second embodiment, as shown in Figure 5, was manufactured and used as the packaging container according to Example 1. Specifically, a cap was manufactured by injection molding, comprising a cap with a first barrier layer 31 covering the entire surface inside the inner ring 13 of the top surface 11 and a second barrier layer 32 covering the entire circumference of the inner ring 13, and a container body 2 with a third barrier layer 33 covering the entire surface of the bottom surface 21 and a fourth barrier layer 34 covering the entire circumference of the side wall 22. At this time, polypropylene was used as the base resin, EVOH was used as the barrier layer, and the thickness of the cap and container body 2 was set to 1.2 mm.

[0072] (Example 2) A wide-mouthed jar container according to the first embodiment, as shown in Figure 2, was manufactured and used as the packaging container for Example 2. Specifically, the packaging container was manufactured in the same manner as in Example 1, except that the cap had a first barrier layer 31 and a third barrier layer 33 on the entire surface inside the inner skirt portion 12b of the top portion 11, a second barrier layer 32 on the entire circumference of the inner ring 13, and a fourth barrier layer 34 on the entire circumference of the inner skirt portion 12b.

[0073] (Comparative Example 1) A packaging container was manufactured in the same manner as in Example 1, except that a barrier layer was provided over the cap and the entire container body 2, resulting in a wide-mouthed jar container as shown in Figure 7.

[0074] (Comparative Example 2) A packaging container was manufactured in the same manner as in Example 1, except that a barrier layer was not provided on the cap and container body 2, and the thickness of the cap and container body 2 was set to 1.5 mm.

[0075] (Comparative Example 3) A packaging container was manufactured in the same manner as in Example 1, except that a gasket was provided instead of a barrier layer on the cap, and a barrier layer was provided over the entire container body 2, as shown in Figure 7, and further extended to the tip of the female thread 6b of the container body 2. The layer configuration of the gasket was GL-RD / High Sheet (registered trademark) / GL-RD. GL-RD: Transparent barrier film (manufactured by Toppan Printing Co., Ltd.) High Sheet: Low-foaming PE sheet (manufactured by RM Tosero Co., Ltd.)

[0076] (Comparative Example 4) A packaging container was manufactured in the same manner as in Example 1, except that a barrier layer was not provided on the cap and container body 2, and the thickness of the cap and container body 2 was set to 4.0 mm.

[0077] (Comparative Example 5) A packaging container was prepared in the same manner as in Example 1, except that the cap and container body 2 were made of a single layer of barrier resin (EVOH).

[0078] Table 1 summarizes the thickness of the cap and container body 2, the base material, the barrier layer formation area, and the presence or absence of a gasket for each example and comparative example.

[0079] [Table 1]

[0080] (Evaluation method) The packaging containers according to the examples and comparative examples were evaluated for gas barrier performance, resin usage, recyclability, and the presence or absence of separation between resins.

[0081] Gas barrier performance was measured using the Mocon method with a Mocon OX-TRAN MODEL2 / 61 OXYGEN PERMEABILITY gas barrier tester at 20°C and 65% humidity. Based on the measurement results, evaluation was performed according to the following criteria. ◎: When the gas permeation rate is 0.02 cc / pkcc / day or less. ○: When the gas permeation rate is 0.04 cc / pkcc / day or less. △: When the gas permeation rate is 0.1 cc / pkcc / day or less. ×: When the gas permeation rate exceeds 0.1 cc / pkcc / day

[0082] The amount of resin used was evaluated according to the following criteria. ×: If the amount of resin used is more than 30.0g ○: When the amount of resin used was between 20.0g and 30g. ◎: If the amount of resin used was less than 20.0g

[0083] Recyclability was evaluated on a four-point scale (◎, ○, △, ×) based on the materials used. ◎ represents the highest level of recyclability, and × represents the lowest level.

[0084] The presence or absence of gaps between resins was evaluated according to the following criteria. ×: If separation between resins is observed during the opening of the packaging container. ○: If no gaps between the resins are visually observed during the opening of the packaging container.

[0085] Based on evaluations of gas barrier performance, resin usage, recyclability, and the presence or absence of separation between resins, an overall assessment was made according to the following criteria. ×: If there is an × or △ in the evaluation of any of the following: gas barrier performance, resin usage, recyclability, or presence or absence of separation between resins. ○: No × or △ ratings were found in any of the evaluations regarding gas barrier performance, resin usage, recyclability, or the presence or absence of separation between resins.

[0086] Table 2 shows the evaluation results for gas barrier performance, resin usage, recyclability, and the presence or absence of separation between resins, as well as the overall assessment.

[0087] [Table 2]

[0088] The packaging container according to Example 1 had a cap and container body 2 with a thickness of 1.2 mm, and a barrier layer was provided in the intermediate layer between the cap and container body 2. As a result, good gas barrier performance was achieved while keeping the amount of resin used to 18.9 g. Furthermore, since the barrier layer was provided only on a part of the cap and container body 2 (the entire surface inside the inner ring 13 of the top surface 11, the entire circumference of the inner ring 13, the entire surface of the bottom surface 21, and the entire circumference of the side wall 22), recyclability was also good. In addition, since no barrier layer was provided on the outer skirt portion 12a, no separation between resins occurred.

[0089] The packaging container in Example 2, like in Example 1, had a cap and container body 2 with a thickness of 1.2 mm, and a barrier layer was provided in the intermediate layer between the cap and container body 2. As a result, good gas barrier performance was achieved while keeping the amount of resin used to 19.5 g. Furthermore, since the barrier layer was provided only on a part of the cap and container body 2, recyclability was also good. However, compared to the cap in Example 1, the area where the barrier layer was provided was wider, so the recyclability was lower than in Example 1. In addition, since the outer skirt portion 12a did not have a barrier layer, resin detachment did not occur.

[0090] The packaging container in Comparative Example 1 had a cap and container body 2 thickness of 1.2 mm, similar to Examples 1 and 2, and a barrier layer was provided in the intermediate layer between the cap and container body 2. Therefore, similar to Examples 1 and 2, it had good gas barrier performance while keeping the amount of resin used low. However, because the barrier layer was provided on the entire surface of the cap and container body 2, its recyclability was inferior to that of Examples 1 and 2. In addition, because a barrier layer was also formed on the outer skirt portion 12a, lifting occurred between the resins.

[0091] The packaging container in Comparative Example 2 had high recyclability because the cap and container body 2 were made of a single layer of PP. However, because there was no barrier layer on the cap and container body 2, the gas barrier performance was inferior to that of Examples 1 and 2, in which the cap and container body 2 were thinner than those of Comparative Example 2.

[0092] The packaging container in Comparative Example 3 did not have a barrier layer on the cap, but instead had a gasket, and a barrier layer was also provided on the container body 2. As a result, the amount of resin used and the gas barrier performance were as good as in Examples 1 and 2, and no separation between resins occurred. However, the presence of a gasket resulted in lower recyclability compared to the examples.

[0093] The packaging container in Comparative Example 4 had a very high recyclability and no separation between resin layers because the cap and container body 2 were made of a single layer of PP. However, even though the amount of resin used was increased to more than 1.6 times that of Examples 1 and 2, and the thickness of the cap 1 and container body 2 was increased, the gas permeability was 1.75 times that of Examples 1 and 2, resulting in inferior gas barrier performance.

[0094] The packaging container in Comparative Example 5 had a cap 1 and container body 2 made of a single layer of EVOH, and therefore had higher gas barrier performance compared to Example 1, which had the same thickness for the cap 1 and container body 2 and a barrier layer in the middle layer, and no separation between the resins occurred. However, it could not be recycled as a polyolefin like PP, which created a problem with recyclability. [Industrial applicability]

[0095] The cap and packaging container according to the present invention can be used as a cap and packaging container that require airtightness. [Explanation of Symbols]

[0096] 1, 10: Cap 2: Container body 5: Mouth 6a: Male screw 6b: Female thread 11:Top section 12: Skirt section 12a: Outer skirt section 12b: Inner skirt section 13: Inner Ring 21: Bottom part 22: Side wall section 23: Exterior wall 24: Connection part 31: First barrier layer 32: Second barrier layer 33: Third barrier layer 34: Fourth barrier layer 35: Fifth barrier layer 36: Sixth Barrier Layer 100, 200: Packaging containers

Claims

1. A cap that is attached to the mouth of the container body, The top surface and, The skirt portion consists of an outer skirt portion connected to the edge of the top surface portion and an inner skirt portion positioned inside the outer skirt portion, It comprises a cylindrical inner ring provided on the inside of the top surface and capable of fitting with the inner circumferential surface of the opening, The top surface portion includes a first barrier layer provided in the intermediate layer inside the inner ring, The inner ring includes a second barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the first barrier layer. A cap in which no barrier layer is provided in the intermediate layer of the outer skirt portion.

2. A cap that is attached to the mouth of the container body, The top surface and, A skirt portion extending vertically from the edge of the top surface portion and It comprises a cylindrical inner ring provided on the inside of the top surface and capable of fitting with the inner circumferential surface of the opening, The top surface portion includes a first barrier layer provided in the intermediate layer inside the inner ring, The inner ring includes a second barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the first barrier layer. A cap in which no barrier layer is provided in the intermediate layer of the skirt portion and in the intermediate layer of the portion of the top surface located outside the inner ring.

3. The cap according to claim 1, wherein the intermediate layer of the top surface portion located outside the inner skirt portion is not provided with a barrier layer.

4. The top surface portion includes a third barrier layer provided in the intermediate layer region from outside the inner ring to the inner skirt portion, and connected to the entire circumference of the second barrier layer. The inner skirt portion includes a fourth barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the third barrier layer. The cap according to claim 1, wherein the edge of the fourth barrier layer is located further from the top surface than the edge of the inner ring.

5. The cap according to claim 1 or 2, wherein the barrier layer provided in the intermediate layer is unevenly distributed towards the inside of the container body with respect to the thickness direction of the container body.

6. A cap according to claim 1 or 2, formed by injection molding.

7. The container comprises the cap according to claim 1 or 2 and the container body, The container body has a bottom portion and a side wall portion that extends vertically from the edge of the bottom portion and forms the opening portion. The bottom portion includes a fifth barrier layer provided in the intermediate layer over its entire surface. The side wall portion includes a sixth barrier layer provided in the intermediate layer around its entire circumference and connected to the entire circumference of the fifth barrier layer. A packaging container in which the second barrier layer and the sixth barrier layer overlap when viewed from the side with the cap attached to the container body.

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